Properly set arm-specific elf flags wrt hardfp.
[deliverable/binutils-gdb.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright (C) 2009-2015 Free Software Foundation, Inc.
4 // Written by Doug Kwan <dougkwan@google.com> based on the i386 code
5 // by Ian Lance Taylor <iant@google.com>.
6 // This file also contains borrowed and adapted code from
7 // bfd/elf32-arm.c.
8
9 // This file is part of gold.
10
11 // This program is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU General Public License as published by
13 // the Free Software Foundation; either version 3 of the License, or
14 // (at your option) any later version.
15
16 // This program is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 // GNU General Public License for more details.
20
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
24 // MA 02110-1301, USA.
25
26 #include "gold.h"
27
28 #include <cstring>
29 #include <limits>
30 #include <cstdio>
31 #include <string>
32 #include <algorithm>
33 #include <map>
34 #include <utility>
35 #include <set>
36
37 #include "elfcpp.h"
38 #include "parameters.h"
39 #include "reloc.h"
40 #include "arm.h"
41 #include "object.h"
42 #include "symtab.h"
43 #include "layout.h"
44 #include "output.h"
45 #include "copy-relocs.h"
46 #include "target.h"
47 #include "target-reloc.h"
48 #include "target-select.h"
49 #include "tls.h"
50 #include "defstd.h"
51 #include "gc.h"
52 #include "attributes.h"
53 #include "arm-reloc-property.h"
54 #include "nacl.h"
55
56 namespace
57 {
58
59 using namespace gold;
60
61 template<bool big_endian>
62 class Output_data_plt_arm;
63
64 template<bool big_endian>
65 class Output_data_plt_arm_standard;
66
67 template<bool big_endian>
68 class Stub_table;
69
70 template<bool big_endian>
71 class Arm_input_section;
72
73 class Arm_exidx_cantunwind;
74
75 class Arm_exidx_merged_section;
76
77 class Arm_exidx_fixup;
78
79 template<bool big_endian>
80 class Arm_output_section;
81
82 class Arm_exidx_input_section;
83
84 template<bool big_endian>
85 class Arm_relobj;
86
87 template<bool big_endian>
88 class Arm_relocate_functions;
89
90 template<bool big_endian>
91 class Arm_output_data_got;
92
93 template<bool big_endian>
94 class Target_arm;
95
96 // For convenience.
97 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
98
99 // Maximum branch offsets for ARM, THUMB and THUMB2.
100 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
101 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
102 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
103 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
104 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
105 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
106
107 // Thread Control Block size.
108 const size_t ARM_TCB_SIZE = 8;
109
110 // The arm target class.
111 //
112 // This is a very simple port of gold for ARM-EABI. It is intended for
113 // supporting Android only for the time being.
114 //
115 // TODOs:
116 // - Implement all static relocation types documented in arm-reloc.def.
117 // - Make PLTs more flexible for different architecture features like
118 // Thumb-2 and BE8.
119 // There are probably a lot more.
120
121 // Ideally we would like to avoid using global variables but this is used
122 // very in many places and sometimes in loops. If we use a function
123 // returning a static instance of Arm_reloc_property_table, it will be very
124 // slow in an threaded environment since the static instance needs to be
125 // locked. The pointer is below initialized in the
126 // Target::do_select_as_default_target() hook so that we do not spend time
127 // building the table if we are not linking ARM objects.
128 //
129 // An alternative is to to process the information in arm-reloc.def in
130 // compilation time and generate a representation of it in PODs only. That
131 // way we can avoid initialization when the linker starts.
132
133 Arm_reloc_property_table* arm_reloc_property_table = NULL;
134
135 // Instruction template class. This class is similar to the insn_sequence
136 // struct in bfd/elf32-arm.c.
137
138 class Insn_template
139 {
140 public:
141 // Types of instruction templates.
142 enum Type
143 {
144 THUMB16_TYPE = 1,
145 // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
146 // templates with class-specific semantics. Currently this is used
147 // only by the Cortex_a8_stub class for handling condition codes in
148 // conditional branches.
149 THUMB16_SPECIAL_TYPE,
150 THUMB32_TYPE,
151 ARM_TYPE,
152 DATA_TYPE
153 };
154
155 // Factory methods to create instruction templates in different formats.
156
157 static const Insn_template
158 thumb16_insn(uint32_t data)
159 { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
160
161 // A Thumb conditional branch, in which the proper condition is inserted
162 // when we build the stub.
163 static const Insn_template
164 thumb16_bcond_insn(uint32_t data)
165 { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
166
167 static const Insn_template
168 thumb32_insn(uint32_t data)
169 { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
170
171 static const Insn_template
172 thumb32_b_insn(uint32_t data, int reloc_addend)
173 {
174 return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
175 reloc_addend);
176 }
177
178 static const Insn_template
179 arm_insn(uint32_t data)
180 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
181
182 static const Insn_template
183 arm_rel_insn(unsigned data, int reloc_addend)
184 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
185
186 static const Insn_template
187 data_word(unsigned data, unsigned int r_type, int reloc_addend)
188 { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
189
190 // Accessors. This class is used for read-only objects so no modifiers
191 // are provided.
192
193 uint32_t
194 data() const
195 { return this->data_; }
196
197 // Return the instruction sequence type of this.
198 Type
199 type() const
200 { return this->type_; }
201
202 // Return the ARM relocation type of this.
203 unsigned int
204 r_type() const
205 { return this->r_type_; }
206
207 int32_t
208 reloc_addend() const
209 { return this->reloc_addend_; }
210
211 // Return size of instruction template in bytes.
212 size_t
213 size() const;
214
215 // Return byte-alignment of instruction template.
216 unsigned
217 alignment() const;
218
219 private:
220 // We make the constructor private to ensure that only the factory
221 // methods are used.
222 inline
223 Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
224 : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
225 { }
226
227 // Instruction specific data. This is used to store information like
228 // some of the instruction bits.
229 uint32_t data_;
230 // Instruction template type.
231 Type type_;
232 // Relocation type if there is a relocation or R_ARM_NONE otherwise.
233 unsigned int r_type_;
234 // Relocation addend.
235 int32_t reloc_addend_;
236 };
237
238 // Macro for generating code to stub types. One entry per long/short
239 // branch stub
240
241 #define DEF_STUBS \
242 DEF_STUB(long_branch_any_any) \
243 DEF_STUB(long_branch_v4t_arm_thumb) \
244 DEF_STUB(long_branch_thumb_only) \
245 DEF_STUB(long_branch_v4t_thumb_thumb) \
246 DEF_STUB(long_branch_v4t_thumb_arm) \
247 DEF_STUB(short_branch_v4t_thumb_arm) \
248 DEF_STUB(long_branch_any_arm_pic) \
249 DEF_STUB(long_branch_any_thumb_pic) \
250 DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
251 DEF_STUB(long_branch_v4t_arm_thumb_pic) \
252 DEF_STUB(long_branch_v4t_thumb_arm_pic) \
253 DEF_STUB(long_branch_thumb_only_pic) \
254 DEF_STUB(a8_veneer_b_cond) \
255 DEF_STUB(a8_veneer_b) \
256 DEF_STUB(a8_veneer_bl) \
257 DEF_STUB(a8_veneer_blx) \
258 DEF_STUB(v4_veneer_bx)
259
260 // Stub types.
261
262 #define DEF_STUB(x) arm_stub_##x,
263 typedef enum
264 {
265 arm_stub_none,
266 DEF_STUBS
267
268 // First reloc stub type.
269 arm_stub_reloc_first = arm_stub_long_branch_any_any,
270 // Last reloc stub type.
271 arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
272
273 // First Cortex-A8 stub type.
274 arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
275 // Last Cortex-A8 stub type.
276 arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
277
278 // Last stub type.
279 arm_stub_type_last = arm_stub_v4_veneer_bx
280 } Stub_type;
281 #undef DEF_STUB
282
283 // Stub template class. Templates are meant to be read-only objects.
284 // A stub template for a stub type contains all read-only attributes
285 // common to all stubs of the same type.
286
287 class Stub_template
288 {
289 public:
290 Stub_template(Stub_type, const Insn_template*, size_t);
291
292 ~Stub_template()
293 { }
294
295 // Return stub type.
296 Stub_type
297 type() const
298 { return this->type_; }
299
300 // Return an array of instruction templates.
301 const Insn_template*
302 insns() const
303 { return this->insns_; }
304
305 // Return size of template in number of instructions.
306 size_t
307 insn_count() const
308 { return this->insn_count_; }
309
310 // Return size of template in bytes.
311 size_t
312 size() const
313 { return this->size_; }
314
315 // Return alignment of the stub template.
316 unsigned
317 alignment() const
318 { return this->alignment_; }
319
320 // Return whether entry point is in thumb mode.
321 bool
322 entry_in_thumb_mode() const
323 { return this->entry_in_thumb_mode_; }
324
325 // Return number of relocations in this template.
326 size_t
327 reloc_count() const
328 { return this->relocs_.size(); }
329
330 // Return index of the I-th instruction with relocation.
331 size_t
332 reloc_insn_index(size_t i) const
333 {
334 gold_assert(i < this->relocs_.size());
335 return this->relocs_[i].first;
336 }
337
338 // Return the offset of the I-th instruction with relocation from the
339 // beginning of the stub.
340 section_size_type
341 reloc_offset(size_t i) const
342 {
343 gold_assert(i < this->relocs_.size());
344 return this->relocs_[i].second;
345 }
346
347 private:
348 // This contains information about an instruction template with a relocation
349 // and its offset from start of stub.
350 typedef std::pair<size_t, section_size_type> Reloc;
351
352 // A Stub_template may not be copied. We want to share templates as much
353 // as possible.
354 Stub_template(const Stub_template&);
355 Stub_template& operator=(const Stub_template&);
356
357 // Stub type.
358 Stub_type type_;
359 // Points to an array of Insn_templates.
360 const Insn_template* insns_;
361 // Number of Insn_templates in insns_[].
362 size_t insn_count_;
363 // Size of templated instructions in bytes.
364 size_t size_;
365 // Alignment of templated instructions.
366 unsigned alignment_;
367 // Flag to indicate if entry is in thumb mode.
368 bool entry_in_thumb_mode_;
369 // A table of reloc instruction indices and offsets. We can find these by
370 // looking at the instruction templates but we pre-compute and then stash
371 // them here for speed.
372 std::vector<Reloc> relocs_;
373 };
374
375 //
376 // A class for code stubs. This is a base class for different type of
377 // stubs used in the ARM target.
378 //
379
380 class Stub
381 {
382 private:
383 static const section_offset_type invalid_offset =
384 static_cast<section_offset_type>(-1);
385
386 public:
387 Stub(const Stub_template* stub_template)
388 : stub_template_(stub_template), offset_(invalid_offset)
389 { }
390
391 virtual
392 ~Stub()
393 { }
394
395 // Return the stub template.
396 const Stub_template*
397 stub_template() const
398 { return this->stub_template_; }
399
400 // Return offset of code stub from beginning of its containing stub table.
401 section_offset_type
402 offset() const
403 {
404 gold_assert(this->offset_ != invalid_offset);
405 return this->offset_;
406 }
407
408 // Set offset of code stub from beginning of its containing stub table.
409 void
410 set_offset(section_offset_type offset)
411 { this->offset_ = offset; }
412
413 // Return the relocation target address of the i-th relocation in the
414 // stub. This must be defined in a child class.
415 Arm_address
416 reloc_target(size_t i)
417 { return this->do_reloc_target(i); }
418
419 // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written.
420 void
421 write(unsigned char* view, section_size_type view_size, bool big_endian)
422 { this->do_write(view, view_size, big_endian); }
423
424 // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
425 // for the i-th instruction.
426 uint16_t
427 thumb16_special(size_t i)
428 { return this->do_thumb16_special(i); }
429
430 protected:
431 // This must be defined in the child class.
432 virtual Arm_address
433 do_reloc_target(size_t) = 0;
434
435 // This may be overridden in the child class.
436 virtual void
437 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
438 {
439 if (big_endian)
440 this->do_fixed_endian_write<true>(view, view_size);
441 else
442 this->do_fixed_endian_write<false>(view, view_size);
443 }
444
445 // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
446 // instruction template.
447 virtual uint16_t
448 do_thumb16_special(size_t)
449 { gold_unreachable(); }
450
451 private:
452 // A template to implement do_write.
453 template<bool big_endian>
454 void inline
455 do_fixed_endian_write(unsigned char*, section_size_type);
456
457 // Its template.
458 const Stub_template* stub_template_;
459 // Offset within the section of containing this stub.
460 section_offset_type offset_;
461 };
462
463 // Reloc stub class. These are stubs we use to fix up relocation because
464 // of limited branch ranges.
465
466 class Reloc_stub : public Stub
467 {
468 public:
469 static const unsigned int invalid_index = static_cast<unsigned int>(-1);
470 // We assume we never jump to this address.
471 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
472
473 // Return destination address.
474 Arm_address
475 destination_address() const
476 {
477 gold_assert(this->destination_address_ != this->invalid_address);
478 return this->destination_address_;
479 }
480
481 // Set destination address.
482 void
483 set_destination_address(Arm_address address)
484 {
485 gold_assert(address != this->invalid_address);
486 this->destination_address_ = address;
487 }
488
489 // Reset destination address.
490 void
491 reset_destination_address()
492 { this->destination_address_ = this->invalid_address; }
493
494 // Determine stub type for a branch of a relocation of R_TYPE going
495 // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set,
496 // the branch target is a thumb instruction. TARGET is used for look
497 // up ARM-specific linker settings.
498 static Stub_type
499 stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
500 Arm_address branch_target, bool target_is_thumb);
501
502 // Reloc_stub key. A key is logically a triplet of a stub type, a symbol
503 // and an addend. Since we treat global and local symbol differently, we
504 // use a Symbol object for a global symbol and a object-index pair for
505 // a local symbol.
506 class Key
507 {
508 public:
509 // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
510 // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL
511 // and R_SYM must not be invalid_index.
512 Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
513 unsigned int r_sym, int32_t addend)
514 : stub_type_(stub_type), addend_(addend)
515 {
516 if (symbol != NULL)
517 {
518 this->r_sym_ = Reloc_stub::invalid_index;
519 this->u_.symbol = symbol;
520 }
521 else
522 {
523 gold_assert(relobj != NULL && r_sym != invalid_index);
524 this->r_sym_ = r_sym;
525 this->u_.relobj = relobj;
526 }
527 }
528
529 ~Key()
530 { }
531
532 // Accessors: Keys are meant to be read-only object so no modifiers are
533 // provided.
534
535 // Return stub type.
536 Stub_type
537 stub_type() const
538 { return this->stub_type_; }
539
540 // Return the local symbol index or invalid_index.
541 unsigned int
542 r_sym() const
543 { return this->r_sym_; }
544
545 // Return the symbol if there is one.
546 const Symbol*
547 symbol() const
548 { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
549
550 // Return the relobj if there is one.
551 const Relobj*
552 relobj() const
553 { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
554
555 // Whether this equals to another key k.
556 bool
557 eq(const Key& k) const
558 {
559 return ((this->stub_type_ == k.stub_type_)
560 && (this->r_sym_ == k.r_sym_)
561 && ((this->r_sym_ != Reloc_stub::invalid_index)
562 ? (this->u_.relobj == k.u_.relobj)
563 : (this->u_.symbol == k.u_.symbol))
564 && (this->addend_ == k.addend_));
565 }
566
567 // Return a hash value.
568 size_t
569 hash_value() const
570 {
571 return (this->stub_type_
572 ^ this->r_sym_
573 ^ gold::string_hash<char>(
574 (this->r_sym_ != Reloc_stub::invalid_index)
575 ? this->u_.relobj->name().c_str()
576 : this->u_.symbol->name())
577 ^ this->addend_);
578 }
579
580 // Functors for STL associative containers.
581 struct hash
582 {
583 size_t
584 operator()(const Key& k) const
585 { return k.hash_value(); }
586 };
587
588 struct equal_to
589 {
590 bool
591 operator()(const Key& k1, const Key& k2) const
592 { return k1.eq(k2); }
593 };
594
595 // Name of key. This is mainly for debugging.
596 std::string
597 name() const;
598
599 private:
600 // Stub type.
601 Stub_type stub_type_;
602 // If this is a local symbol, this is the index in the defining object.
603 // Otherwise, it is invalid_index for a global symbol.
604 unsigned int r_sym_;
605 // If r_sym_ is an invalid index, this points to a global symbol.
606 // Otherwise, it points to a relobj. We used the unsized and target
607 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
608 // Arm_relobj, in order to avoid making the stub class a template
609 // as most of the stub machinery is endianness-neutral. However, it
610 // may require a bit of casting done by users of this class.
611 union
612 {
613 const Symbol* symbol;
614 const Relobj* relobj;
615 } u_;
616 // Addend associated with a reloc.
617 int32_t addend_;
618 };
619
620 protected:
621 // Reloc_stubs are created via a stub factory. So these are protected.
622 Reloc_stub(const Stub_template* stub_template)
623 : Stub(stub_template), destination_address_(invalid_address)
624 { }
625
626 ~Reloc_stub()
627 { }
628
629 friend class Stub_factory;
630
631 // Return the relocation target address of the i-th relocation in the
632 // stub.
633 Arm_address
634 do_reloc_target(size_t i)
635 {
636 // All reloc stub have only one relocation.
637 gold_assert(i == 0);
638 return this->destination_address_;
639 }
640
641 private:
642 // Address of destination.
643 Arm_address destination_address_;
644 };
645
646 // Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit
647 // THUMB branch that meets the following conditions:
648 //
649 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
650 // branch address is 0xffe.
651 // 2. The branch target address is in the same page as the first word of the
652 // branch.
653 // 3. The branch follows a 32-bit instruction which is not a branch.
654 //
655 // To do the fix up, we need to store the address of the branch instruction
656 // and its target at least. We also need to store the original branch
657 // instruction bits for the condition code in a conditional branch. The
658 // condition code is used in a special instruction template. We also want
659 // to identify input sections needing Cortex-A8 workaround quickly. We store
660 // extra information about object and section index of the code section
661 // containing a branch being fixed up. The information is used to mark
662 // the code section when we finalize the Cortex-A8 stubs.
663 //
664
665 class Cortex_a8_stub : public Stub
666 {
667 public:
668 ~Cortex_a8_stub()
669 { }
670
671 // Return the object of the code section containing the branch being fixed
672 // up.
673 Relobj*
674 relobj() const
675 { return this->relobj_; }
676
677 // Return the section index of the code section containing the branch being
678 // fixed up.
679 unsigned int
680 shndx() const
681 { return this->shndx_; }
682
683 // Return the source address of stub. This is the address of the original
684 // branch instruction. LSB is 1 always set to indicate that it is a THUMB
685 // instruction.
686 Arm_address
687 source_address() const
688 { return this->source_address_; }
689
690 // Return the destination address of the stub. This is the branch taken
691 // address of the original branch instruction. LSB is 1 if it is a THUMB
692 // instruction address.
693 Arm_address
694 destination_address() const
695 { return this->destination_address_; }
696
697 // Return the instruction being fixed up.
698 uint32_t
699 original_insn() const
700 { return this->original_insn_; }
701
702 protected:
703 // Cortex_a8_stubs are created via a stub factory. So these are protected.
704 Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
705 unsigned int shndx, Arm_address source_address,
706 Arm_address destination_address, uint32_t original_insn)
707 : Stub(stub_template), relobj_(relobj), shndx_(shndx),
708 source_address_(source_address | 1U),
709 destination_address_(destination_address),
710 original_insn_(original_insn)
711 { }
712
713 friend class Stub_factory;
714
715 // Return the relocation target address of the i-th relocation in the
716 // stub.
717 Arm_address
718 do_reloc_target(size_t i)
719 {
720 if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
721 {
722 // The conditional branch veneer has two relocations.
723 gold_assert(i < 2);
724 return i == 0 ? this->source_address_ + 4 : this->destination_address_;
725 }
726 else
727 {
728 // All other Cortex-A8 stubs have only one relocation.
729 gold_assert(i == 0);
730 return this->destination_address_;
731 }
732 }
733
734 // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
735 uint16_t
736 do_thumb16_special(size_t);
737
738 private:
739 // Object of the code section containing the branch being fixed up.
740 Relobj* relobj_;
741 // Section index of the code section containing the branch begin fixed up.
742 unsigned int shndx_;
743 // Source address of original branch.
744 Arm_address source_address_;
745 // Destination address of the original branch.
746 Arm_address destination_address_;
747 // Original branch instruction. This is needed for copying the condition
748 // code from a condition branch to its stub.
749 uint32_t original_insn_;
750 };
751
752 // ARMv4 BX Rx branch relocation stub class.
753 class Arm_v4bx_stub : public Stub
754 {
755 public:
756 ~Arm_v4bx_stub()
757 { }
758
759 // Return the associated register.
760 uint32_t
761 reg() const
762 { return this->reg_; }
763
764 protected:
765 // Arm V4BX stubs are created via a stub factory. So these are protected.
766 Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
767 : Stub(stub_template), reg_(reg)
768 { }
769
770 friend class Stub_factory;
771
772 // Return the relocation target address of the i-th relocation in the
773 // stub.
774 Arm_address
775 do_reloc_target(size_t)
776 { gold_unreachable(); }
777
778 // This may be overridden in the child class.
779 virtual void
780 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
781 {
782 if (big_endian)
783 this->do_fixed_endian_v4bx_write<true>(view, view_size);
784 else
785 this->do_fixed_endian_v4bx_write<false>(view, view_size);
786 }
787
788 private:
789 // A template to implement do_write.
790 template<bool big_endian>
791 void inline
792 do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
793 {
794 const Insn_template* insns = this->stub_template()->insns();
795 elfcpp::Swap<32, big_endian>::writeval(view,
796 (insns[0].data()
797 + (this->reg_ << 16)));
798 view += insns[0].size();
799 elfcpp::Swap<32, big_endian>::writeval(view,
800 (insns[1].data() + this->reg_));
801 view += insns[1].size();
802 elfcpp::Swap<32, big_endian>::writeval(view,
803 (insns[2].data() + this->reg_));
804 }
805
806 // A register index (r0-r14), which is associated with the stub.
807 uint32_t reg_;
808 };
809
810 // Stub factory class.
811
812 class Stub_factory
813 {
814 public:
815 // Return the unique instance of this class.
816 static const Stub_factory&
817 get_instance()
818 {
819 static Stub_factory singleton;
820 return singleton;
821 }
822
823 // Make a relocation stub.
824 Reloc_stub*
825 make_reloc_stub(Stub_type stub_type) const
826 {
827 gold_assert(stub_type >= arm_stub_reloc_first
828 && stub_type <= arm_stub_reloc_last);
829 return new Reloc_stub(this->stub_templates_[stub_type]);
830 }
831
832 // Make a Cortex-A8 stub.
833 Cortex_a8_stub*
834 make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
835 Arm_address source, Arm_address destination,
836 uint32_t original_insn) const
837 {
838 gold_assert(stub_type >= arm_stub_cortex_a8_first
839 && stub_type <= arm_stub_cortex_a8_last);
840 return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
841 source, destination, original_insn);
842 }
843
844 // Make an ARM V4BX relocation stub.
845 // This method creates a stub from the arm_stub_v4_veneer_bx template only.
846 Arm_v4bx_stub*
847 make_arm_v4bx_stub(uint32_t reg) const
848 {
849 gold_assert(reg < 0xf);
850 return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
851 reg);
852 }
853
854 private:
855 // Constructor and destructor are protected since we only return a single
856 // instance created in Stub_factory::get_instance().
857
858 Stub_factory();
859
860 // A Stub_factory may not be copied since it is a singleton.
861 Stub_factory(const Stub_factory&);
862 Stub_factory& operator=(Stub_factory&);
863
864 // Stub templates. These are initialized in the constructor.
865 const Stub_template* stub_templates_[arm_stub_type_last+1];
866 };
867
868 // A class to hold stubs for the ARM target.
869
870 template<bool big_endian>
871 class Stub_table : public Output_data
872 {
873 public:
874 Stub_table(Arm_input_section<big_endian>* owner)
875 : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
876 reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
877 prev_data_size_(0), prev_addralign_(1)
878 { }
879
880 ~Stub_table()
881 { }
882
883 // Owner of this stub table.
884 Arm_input_section<big_endian>*
885 owner() const
886 { return this->owner_; }
887
888 // Whether this stub table is empty.
889 bool
890 empty() const
891 {
892 return (this->reloc_stubs_.empty()
893 && this->cortex_a8_stubs_.empty()
894 && this->arm_v4bx_stubs_.empty());
895 }
896
897 // Return the current data size.
898 off_t
899 current_data_size() const
900 { return this->current_data_size_for_child(); }
901
902 // Add a STUB using KEY. The caller is responsible for avoiding addition
903 // if a STUB with the same key has already been added.
904 void
905 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
906 {
907 const Stub_template* stub_template = stub->stub_template();
908 gold_assert(stub_template->type() == key.stub_type());
909 this->reloc_stubs_[key] = stub;
910
911 // Assign stub offset early. We can do this because we never remove
912 // reloc stubs and they are in the beginning of the stub table.
913 uint64_t align = stub_template->alignment();
914 this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
915 stub->set_offset(this->reloc_stubs_size_);
916 this->reloc_stubs_size_ += stub_template->size();
917 this->reloc_stubs_addralign_ =
918 std::max(this->reloc_stubs_addralign_, align);
919 }
920
921 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
922 // The caller is responsible for avoiding addition if a STUB with the same
923 // address has already been added.
924 void
925 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
926 {
927 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
928 this->cortex_a8_stubs_.insert(value);
929 }
930
931 // Add an ARM V4BX relocation stub. A register index will be retrieved
932 // from the stub.
933 void
934 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
935 {
936 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
937 this->arm_v4bx_stubs_[stub->reg()] = stub;
938 }
939
940 // Remove all Cortex-A8 stubs.
941 void
942 remove_all_cortex_a8_stubs();
943
944 // Look up a relocation stub using KEY. Return NULL if there is none.
945 Reloc_stub*
946 find_reloc_stub(const Reloc_stub::Key& key) const
947 {
948 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
949 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
950 }
951
952 // Look up an arm v4bx relocation stub using the register index.
953 // Return NULL if there is none.
954 Arm_v4bx_stub*
955 find_arm_v4bx_stub(const uint32_t reg) const
956 {
957 gold_assert(reg < 0xf);
958 return this->arm_v4bx_stubs_[reg];
959 }
960
961 // Relocate stubs in this stub table.
962 void
963 relocate_stubs(const Relocate_info<32, big_endian>*,
964 Target_arm<big_endian>*, Output_section*,
965 unsigned char*, Arm_address, section_size_type);
966
967 // Update data size and alignment at the end of a relaxation pass. Return
968 // true if either data size or alignment is different from that of the
969 // previous relaxation pass.
970 bool
971 update_data_size_and_addralign();
972
973 // Finalize stubs. Set the offsets of all stubs and mark input sections
974 // needing the Cortex-A8 workaround.
975 void
976 finalize_stubs();
977
978 // Apply Cortex-A8 workaround to an address range.
979 void
980 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
981 unsigned char*, Arm_address,
982 section_size_type);
983
984 protected:
985 // Write out section contents.
986 void
987 do_write(Output_file*);
988
989 // Return the required alignment.
990 uint64_t
991 do_addralign() const
992 { return this->prev_addralign_; }
993
994 // Reset address and file offset.
995 void
996 do_reset_address_and_file_offset()
997 { this->set_current_data_size_for_child(this->prev_data_size_); }
998
999 // Set final data size.
1000 void
1001 set_final_data_size()
1002 { this->set_data_size(this->current_data_size()); }
1003
1004 private:
1005 // Relocate one stub.
1006 void
1007 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1008 Target_arm<big_endian>*, Output_section*,
1009 unsigned char*, Arm_address, section_size_type);
1010
1011 // Unordered map of relocation stubs.
1012 typedef
1013 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1014 Reloc_stub::Key::equal_to>
1015 Reloc_stub_map;
1016
1017 // List of Cortex-A8 stubs ordered by addresses of branches being
1018 // fixed up in output.
1019 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1020 // List of Arm V4BX relocation stubs ordered by associated registers.
1021 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1022
1023 // Owner of this stub table.
1024 Arm_input_section<big_endian>* owner_;
1025 // The relocation stubs.
1026 Reloc_stub_map reloc_stubs_;
1027 // Size of reloc stubs.
1028 off_t reloc_stubs_size_;
1029 // Maximum address alignment of reloc stubs.
1030 uint64_t reloc_stubs_addralign_;
1031 // The cortex_a8_stubs.
1032 Cortex_a8_stub_list cortex_a8_stubs_;
1033 // The Arm V4BX relocation stubs.
1034 Arm_v4bx_stub_list arm_v4bx_stubs_;
1035 // data size of this in the previous pass.
1036 off_t prev_data_size_;
1037 // address alignment of this in the previous pass.
1038 uint64_t prev_addralign_;
1039 };
1040
1041 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1042 // we add to the end of an EXIDX input section that goes into the output.
1043
1044 class Arm_exidx_cantunwind : public Output_section_data
1045 {
1046 public:
1047 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1048 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1049 { }
1050
1051 // Return the object containing the section pointed by this.
1052 Relobj*
1053 relobj() const
1054 { return this->relobj_; }
1055
1056 // Return the section index of the section pointed by this.
1057 unsigned int
1058 shndx() const
1059 { return this->shndx_; }
1060
1061 protected:
1062 void
1063 do_write(Output_file* of)
1064 {
1065 if (parameters->target().is_big_endian())
1066 this->do_fixed_endian_write<true>(of);
1067 else
1068 this->do_fixed_endian_write<false>(of);
1069 }
1070
1071 // Write to a map file.
1072 void
1073 do_print_to_mapfile(Mapfile* mapfile) const
1074 { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1075
1076 private:
1077 // Implement do_write for a given endianness.
1078 template<bool big_endian>
1079 void inline
1080 do_fixed_endian_write(Output_file*);
1081
1082 // The object containing the section pointed by this.
1083 Relobj* relobj_;
1084 // The section index of the section pointed by this.
1085 unsigned int shndx_;
1086 };
1087
1088 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1089 // Offset map is used to map input section offset within the EXIDX section
1090 // to the output offset from the start of this EXIDX section.
1091
1092 typedef std::map<section_offset_type, section_offset_type>
1093 Arm_exidx_section_offset_map;
1094
1095 // Arm_exidx_merged_section class. This represents an EXIDX input section
1096 // with some of its entries merged.
1097
1098 class Arm_exidx_merged_section : public Output_relaxed_input_section
1099 {
1100 public:
1101 // Constructor for Arm_exidx_merged_section.
1102 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1103 // SECTION_OFFSET_MAP points to a section offset map describing how
1104 // parts of the input section are mapped to output. DELETED_BYTES is
1105 // the number of bytes deleted from the EXIDX input section.
1106 Arm_exidx_merged_section(
1107 const Arm_exidx_input_section& exidx_input_section,
1108 const Arm_exidx_section_offset_map& section_offset_map,
1109 uint32_t deleted_bytes);
1110
1111 // Build output contents.
1112 void
1113 build_contents(const unsigned char*, section_size_type);
1114
1115 // Return the original EXIDX input section.
1116 const Arm_exidx_input_section&
1117 exidx_input_section() const
1118 { return this->exidx_input_section_; }
1119
1120 // Return the section offset map.
1121 const Arm_exidx_section_offset_map&
1122 section_offset_map() const
1123 { return this->section_offset_map_; }
1124
1125 protected:
1126 // Write merged section into file OF.
1127 void
1128 do_write(Output_file* of);
1129
1130 bool
1131 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1132 section_offset_type*) const;
1133
1134 private:
1135 // Original EXIDX input section.
1136 const Arm_exidx_input_section& exidx_input_section_;
1137 // Section offset map.
1138 const Arm_exidx_section_offset_map& section_offset_map_;
1139 // Merged section contents. We need to keep build the merged section
1140 // and save it here to avoid accessing the original EXIDX section when
1141 // we cannot lock the sections' object.
1142 unsigned char* section_contents_;
1143 };
1144
1145 // A class to wrap an ordinary input section containing executable code.
1146
1147 template<bool big_endian>
1148 class Arm_input_section : public Output_relaxed_input_section
1149 {
1150 public:
1151 Arm_input_section(Relobj* relobj, unsigned int shndx)
1152 : Output_relaxed_input_section(relobj, shndx, 1),
1153 original_addralign_(1), original_size_(0), stub_table_(NULL),
1154 original_contents_(NULL)
1155 { }
1156
1157 ~Arm_input_section()
1158 { delete[] this->original_contents_; }
1159
1160 // Initialize.
1161 void
1162 init();
1163
1164 // Whether this is a stub table owner.
1165 bool
1166 is_stub_table_owner() const
1167 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1168
1169 // Return the stub table.
1170 Stub_table<big_endian>*
1171 stub_table() const
1172 { return this->stub_table_; }
1173
1174 // Set the stub_table.
1175 void
1176 set_stub_table(Stub_table<big_endian>* stub_table)
1177 { this->stub_table_ = stub_table; }
1178
1179 // Downcast a base pointer to an Arm_input_section pointer. This is
1180 // not type-safe but we only use Arm_input_section not the base class.
1181 static Arm_input_section<big_endian>*
1182 as_arm_input_section(Output_relaxed_input_section* poris)
1183 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1184
1185 // Return the original size of the section.
1186 uint32_t
1187 original_size() const
1188 { return this->original_size_; }
1189
1190 protected:
1191 // Write data to output file.
1192 void
1193 do_write(Output_file*);
1194
1195 // Return required alignment of this.
1196 uint64_t
1197 do_addralign() const
1198 {
1199 if (this->is_stub_table_owner())
1200 return std::max(this->stub_table_->addralign(),
1201 static_cast<uint64_t>(this->original_addralign_));
1202 else
1203 return this->original_addralign_;
1204 }
1205
1206 // Finalize data size.
1207 void
1208 set_final_data_size();
1209
1210 // Reset address and file offset.
1211 void
1212 do_reset_address_and_file_offset();
1213
1214 // Output offset.
1215 bool
1216 do_output_offset(const Relobj* object, unsigned int shndx,
1217 section_offset_type offset,
1218 section_offset_type* poutput) const
1219 {
1220 if ((object == this->relobj())
1221 && (shndx == this->shndx())
1222 && (offset >= 0)
1223 && (offset <=
1224 convert_types<section_offset_type, uint32_t>(this->original_size_)))
1225 {
1226 *poutput = offset;
1227 return true;
1228 }
1229 else
1230 return false;
1231 }
1232
1233 private:
1234 // Copying is not allowed.
1235 Arm_input_section(const Arm_input_section&);
1236 Arm_input_section& operator=(const Arm_input_section&);
1237
1238 // Address alignment of the original input section.
1239 uint32_t original_addralign_;
1240 // Section size of the original input section.
1241 uint32_t original_size_;
1242 // Stub table.
1243 Stub_table<big_endian>* stub_table_;
1244 // Original section contents. We have to make a copy here since the file
1245 // containing the original section may not be locked when we need to access
1246 // the contents.
1247 unsigned char* original_contents_;
1248 };
1249
1250 // Arm_exidx_fixup class. This is used to define a number of methods
1251 // and keep states for fixing up EXIDX coverage.
1252
1253 class Arm_exidx_fixup
1254 {
1255 public:
1256 Arm_exidx_fixup(Output_section* exidx_output_section,
1257 bool merge_exidx_entries = true)
1258 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1259 last_inlined_entry_(0), last_input_section_(NULL),
1260 section_offset_map_(NULL), first_output_text_section_(NULL),
1261 merge_exidx_entries_(merge_exidx_entries)
1262 { }
1263
1264 ~Arm_exidx_fixup()
1265 { delete this->section_offset_map_; }
1266
1267 // Process an EXIDX section for entry merging. SECTION_CONTENTS points
1268 // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1269 // number of bytes to be deleted in output. If parts of the input EXIDX
1270 // section are merged a heap allocated Arm_exidx_section_offset_map is store
1271 // in the located PSECTION_OFFSET_MAP. The caller owns the map and is
1272 // responsible for releasing it.
1273 template<bool big_endian>
1274 uint32_t
1275 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1276 const unsigned char* section_contents,
1277 section_size_type section_size,
1278 Arm_exidx_section_offset_map** psection_offset_map);
1279
1280 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1281 // input section, if there is not one already.
1282 void
1283 add_exidx_cantunwind_as_needed();
1284
1285 // Return the output section for the text section which is linked to the
1286 // first exidx input in output.
1287 Output_section*
1288 first_output_text_section() const
1289 { return this->first_output_text_section_; }
1290
1291 private:
1292 // Copying is not allowed.
1293 Arm_exidx_fixup(const Arm_exidx_fixup&);
1294 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1295
1296 // Type of EXIDX unwind entry.
1297 enum Unwind_type
1298 {
1299 // No type.
1300 UT_NONE,
1301 // EXIDX_CANTUNWIND.
1302 UT_EXIDX_CANTUNWIND,
1303 // Inlined entry.
1304 UT_INLINED_ENTRY,
1305 // Normal entry.
1306 UT_NORMAL_ENTRY,
1307 };
1308
1309 // Process an EXIDX entry. We only care about the second word of the
1310 // entry. Return true if the entry can be deleted.
1311 bool
1312 process_exidx_entry(uint32_t second_word);
1313
1314 // Update the current section offset map during EXIDX section fix-up.
1315 // If there is no map, create one. INPUT_OFFSET is the offset of a
1316 // reference point, DELETED_BYTES is the number of deleted by in the
1317 // section so far. If DELETE_ENTRY is true, the reference point and
1318 // all offsets after the previous reference point are discarded.
1319 void
1320 update_offset_map(section_offset_type input_offset,
1321 section_size_type deleted_bytes, bool delete_entry);
1322
1323 // EXIDX output section.
1324 Output_section* exidx_output_section_;
1325 // Unwind type of the last EXIDX entry processed.
1326 Unwind_type last_unwind_type_;
1327 // Last seen inlined EXIDX entry.
1328 uint32_t last_inlined_entry_;
1329 // Last processed EXIDX input section.
1330 const Arm_exidx_input_section* last_input_section_;
1331 // Section offset map created in process_exidx_section.
1332 Arm_exidx_section_offset_map* section_offset_map_;
1333 // Output section for the text section which is linked to the first exidx
1334 // input in output.
1335 Output_section* first_output_text_section_;
1336
1337 bool merge_exidx_entries_;
1338 };
1339
1340 // Arm output section class. This is defined mainly to add a number of
1341 // stub generation methods.
1342
1343 template<bool big_endian>
1344 class Arm_output_section : public Output_section
1345 {
1346 public:
1347 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1348
1349 // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1350 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1351 elfcpp::Elf_Xword flags)
1352 : Output_section(name, type,
1353 (type == elfcpp::SHT_ARM_EXIDX
1354 ? flags | elfcpp::SHF_LINK_ORDER
1355 : flags))
1356 {
1357 if (type == elfcpp::SHT_ARM_EXIDX)
1358 this->set_always_keeps_input_sections();
1359 }
1360
1361 ~Arm_output_section()
1362 { }
1363
1364 // Group input sections for stub generation.
1365 void
1366 group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1367
1368 // Downcast a base pointer to an Arm_output_section pointer. This is
1369 // not type-safe but we only use Arm_output_section not the base class.
1370 static Arm_output_section<big_endian>*
1371 as_arm_output_section(Output_section* os)
1372 { return static_cast<Arm_output_section<big_endian>*>(os); }
1373
1374 // Append all input text sections in this into LIST.
1375 void
1376 append_text_sections_to_list(Text_section_list* list);
1377
1378 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1379 // is a list of text input sections sorted in ascending order of their
1380 // output addresses.
1381 void
1382 fix_exidx_coverage(Layout* layout,
1383 const Text_section_list& sorted_text_section,
1384 Symbol_table* symtab,
1385 bool merge_exidx_entries,
1386 const Task* task);
1387
1388 // Link an EXIDX section into its corresponding text section.
1389 void
1390 set_exidx_section_link();
1391
1392 private:
1393 // For convenience.
1394 typedef Output_section::Input_section Input_section;
1395 typedef Output_section::Input_section_list Input_section_list;
1396
1397 // Create a stub group.
1398 void create_stub_group(Input_section_list::const_iterator,
1399 Input_section_list::const_iterator,
1400 Input_section_list::const_iterator,
1401 Target_arm<big_endian>*,
1402 std::vector<Output_relaxed_input_section*>*,
1403 const Task* task);
1404 };
1405
1406 // Arm_exidx_input_section class. This represents an EXIDX input section.
1407
1408 class Arm_exidx_input_section
1409 {
1410 public:
1411 static const section_offset_type invalid_offset =
1412 static_cast<section_offset_type>(-1);
1413
1414 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1415 unsigned int link, uint32_t size,
1416 uint32_t addralign, uint32_t text_size)
1417 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1418 addralign_(addralign), text_size_(text_size), has_errors_(false)
1419 { }
1420
1421 ~Arm_exidx_input_section()
1422 { }
1423
1424 // Accessors: This is a read-only class.
1425
1426 // Return the object containing this EXIDX input section.
1427 Relobj*
1428 relobj() const
1429 { return this->relobj_; }
1430
1431 // Return the section index of this EXIDX input section.
1432 unsigned int
1433 shndx() const
1434 { return this->shndx_; }
1435
1436 // Return the section index of linked text section in the same object.
1437 unsigned int
1438 link() const
1439 { return this->link_; }
1440
1441 // Return size of the EXIDX input section.
1442 uint32_t
1443 size() const
1444 { return this->size_; }
1445
1446 // Return address alignment of EXIDX input section.
1447 uint32_t
1448 addralign() const
1449 { return this->addralign_; }
1450
1451 // Return size of the associated text input section.
1452 uint32_t
1453 text_size() const
1454 { return this->text_size_; }
1455
1456 // Whether there are any errors in the EXIDX input section.
1457 bool
1458 has_errors() const
1459 { return this->has_errors_; }
1460
1461 // Set has-errors flag.
1462 void
1463 set_has_errors()
1464 { this->has_errors_ = true; }
1465
1466 private:
1467 // Object containing this.
1468 Relobj* relobj_;
1469 // Section index of this.
1470 unsigned int shndx_;
1471 // text section linked to this in the same object.
1472 unsigned int link_;
1473 // Size of this. For ARM 32-bit is sufficient.
1474 uint32_t size_;
1475 // Address alignment of this. For ARM 32-bit is sufficient.
1476 uint32_t addralign_;
1477 // Size of associated text section.
1478 uint32_t text_size_;
1479 // Whether this has any errors.
1480 bool has_errors_;
1481 };
1482
1483 // Arm_relobj class.
1484
1485 template<bool big_endian>
1486 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1487 {
1488 public:
1489 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1490
1491 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1492 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1493 : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1494 stub_tables_(), local_symbol_is_thumb_function_(),
1495 attributes_section_data_(NULL), mapping_symbols_info_(),
1496 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1497 output_local_symbol_count_needs_update_(false),
1498 merge_flags_and_attributes_(true)
1499 { }
1500
1501 ~Arm_relobj()
1502 { delete this->attributes_section_data_; }
1503
1504 // Return the stub table of the SHNDX-th section if there is one.
1505 Stub_table<big_endian>*
1506 stub_table(unsigned int shndx) const
1507 {
1508 gold_assert(shndx < this->stub_tables_.size());
1509 return this->stub_tables_[shndx];
1510 }
1511
1512 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1513 void
1514 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1515 {
1516 gold_assert(shndx < this->stub_tables_.size());
1517 this->stub_tables_[shndx] = stub_table;
1518 }
1519
1520 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1521 // index. This is only valid after do_count_local_symbol is called.
1522 bool
1523 local_symbol_is_thumb_function(unsigned int r_sym) const
1524 {
1525 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1526 return this->local_symbol_is_thumb_function_[r_sym];
1527 }
1528
1529 // Scan all relocation sections for stub generation.
1530 void
1531 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1532 const Layout*);
1533
1534 // Convert regular input section with index SHNDX to a relaxed section.
1535 void
1536 convert_input_section_to_relaxed_section(unsigned shndx)
1537 {
1538 // The stubs have relocations and we need to process them after writing
1539 // out the stubs. So relocation now must follow section write.
1540 this->set_section_offset(shndx, -1ULL);
1541 this->set_relocs_must_follow_section_writes();
1542 }
1543
1544 // Downcast a base pointer to an Arm_relobj pointer. This is
1545 // not type-safe but we only use Arm_relobj not the base class.
1546 static Arm_relobj<big_endian>*
1547 as_arm_relobj(Relobj* relobj)
1548 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1549
1550 // Processor-specific flags in ELF file header. This is valid only after
1551 // reading symbols.
1552 elfcpp::Elf_Word
1553 processor_specific_flags() const
1554 { return this->processor_specific_flags_; }
1555
1556 // Attribute section data This is the contents of the .ARM.attribute section
1557 // if there is one.
1558 const Attributes_section_data*
1559 attributes_section_data() const
1560 { return this->attributes_section_data_; }
1561
1562 // Mapping symbol location.
1563 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1564
1565 // Functor for STL container.
1566 struct Mapping_symbol_position_less
1567 {
1568 bool
1569 operator()(const Mapping_symbol_position& p1,
1570 const Mapping_symbol_position& p2) const
1571 {
1572 return (p1.first < p2.first
1573 || (p1.first == p2.first && p1.second < p2.second));
1574 }
1575 };
1576
1577 // We only care about the first character of a mapping symbol, so
1578 // we only store that instead of the whole symbol name.
1579 typedef std::map<Mapping_symbol_position, char,
1580 Mapping_symbol_position_less> Mapping_symbols_info;
1581
1582 // Whether a section contains any Cortex-A8 workaround.
1583 bool
1584 section_has_cortex_a8_workaround(unsigned int shndx) const
1585 {
1586 return (this->section_has_cortex_a8_workaround_ != NULL
1587 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1588 }
1589
1590 // Mark a section that has Cortex-A8 workaround.
1591 void
1592 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1593 {
1594 if (this->section_has_cortex_a8_workaround_ == NULL)
1595 this->section_has_cortex_a8_workaround_ =
1596 new std::vector<bool>(this->shnum(), false);
1597 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1598 }
1599
1600 // Return the EXIDX section of an text section with index SHNDX or NULL
1601 // if the text section has no associated EXIDX section.
1602 const Arm_exidx_input_section*
1603 exidx_input_section_by_link(unsigned int shndx) const
1604 {
1605 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1606 return ((p != this->exidx_section_map_.end()
1607 && p->second->link() == shndx)
1608 ? p->second
1609 : NULL);
1610 }
1611
1612 // Return the EXIDX section with index SHNDX or NULL if there is none.
1613 const Arm_exidx_input_section*
1614 exidx_input_section_by_shndx(unsigned shndx) const
1615 {
1616 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1617 return ((p != this->exidx_section_map_.end()
1618 && p->second->shndx() == shndx)
1619 ? p->second
1620 : NULL);
1621 }
1622
1623 // Whether output local symbol count needs updating.
1624 bool
1625 output_local_symbol_count_needs_update() const
1626 { return this->output_local_symbol_count_needs_update_; }
1627
1628 // Set output_local_symbol_count_needs_update flag to be true.
1629 void
1630 set_output_local_symbol_count_needs_update()
1631 { this->output_local_symbol_count_needs_update_ = true; }
1632
1633 // Update output local symbol count at the end of relaxation.
1634 void
1635 update_output_local_symbol_count();
1636
1637 // Whether we want to merge processor-specific flags and attributes.
1638 bool
1639 merge_flags_and_attributes() const
1640 { return this->merge_flags_and_attributes_; }
1641
1642 // Export list of EXIDX section indices.
1643 void
1644 get_exidx_shndx_list(std::vector<unsigned int>* list) const
1645 {
1646 list->clear();
1647 for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1648 p != this->exidx_section_map_.end();
1649 ++p)
1650 {
1651 if (p->second->shndx() == p->first)
1652 list->push_back(p->first);
1653 }
1654 // Sort list to make result independent of implementation of map.
1655 std::sort(list->begin(), list->end());
1656 }
1657
1658 protected:
1659 // Post constructor setup.
1660 void
1661 do_setup()
1662 {
1663 // Call parent's setup method.
1664 Sized_relobj_file<32, big_endian>::do_setup();
1665
1666 // Initialize look-up tables.
1667 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1668 this->stub_tables_.swap(empty_stub_table_list);
1669 }
1670
1671 // Count the local symbols.
1672 void
1673 do_count_local_symbols(Stringpool_template<char>*,
1674 Stringpool_template<char>*);
1675
1676 void
1677 do_relocate_sections(
1678 const Symbol_table* symtab, const Layout* layout,
1679 const unsigned char* pshdrs, Output_file* of,
1680 typename Sized_relobj_file<32, big_endian>::Views* pivews);
1681
1682 // Read the symbol information.
1683 void
1684 do_read_symbols(Read_symbols_data* sd);
1685
1686 // Process relocs for garbage collection.
1687 void
1688 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1689
1690 private:
1691
1692 // Whether a section needs to be scanned for relocation stubs.
1693 bool
1694 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1695 const Relobj::Output_sections&,
1696 const Symbol_table*, const unsigned char*);
1697
1698 // Whether a section is a scannable text section.
1699 bool
1700 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1701 const Output_section*, const Symbol_table*);
1702
1703 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1704 bool
1705 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1706 unsigned int, Output_section*,
1707 const Symbol_table*);
1708
1709 // Scan a section for the Cortex-A8 erratum.
1710 void
1711 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1712 unsigned int, Output_section*,
1713 Target_arm<big_endian>*);
1714
1715 // Find the linked text section of an EXIDX section by looking at the
1716 // first relocation of the EXIDX section. PSHDR points to the section
1717 // headers of a relocation section and PSYMS points to the local symbols.
1718 // PSHNDX points to a location storing the text section index if found.
1719 // Return whether we can find the linked section.
1720 bool
1721 find_linked_text_section(const unsigned char* pshdr,
1722 const unsigned char* psyms, unsigned int* pshndx);
1723
1724 //
1725 // Make a new Arm_exidx_input_section object for EXIDX section with
1726 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1727 // index of the linked text section.
1728 void
1729 make_exidx_input_section(unsigned int shndx,
1730 const elfcpp::Shdr<32, big_endian>& shdr,
1731 unsigned int text_shndx,
1732 const elfcpp::Shdr<32, big_endian>& text_shdr);
1733
1734 // Return the output address of either a plain input section or a
1735 // relaxed input section. SHNDX is the section index.
1736 Arm_address
1737 simple_input_section_output_address(unsigned int, Output_section*);
1738
1739 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1740 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1741 Exidx_section_map;
1742
1743 // List of stub tables.
1744 Stub_table_list stub_tables_;
1745 // Bit vector to tell if a local symbol is a thumb function or not.
1746 // This is only valid after do_count_local_symbol is called.
1747 std::vector<bool> local_symbol_is_thumb_function_;
1748 // processor-specific flags in ELF file header.
1749 elfcpp::Elf_Word processor_specific_flags_;
1750 // Object attributes if there is an .ARM.attributes section or NULL.
1751 Attributes_section_data* attributes_section_data_;
1752 // Mapping symbols information.
1753 Mapping_symbols_info mapping_symbols_info_;
1754 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1755 std::vector<bool>* section_has_cortex_a8_workaround_;
1756 // Map a text section to its associated .ARM.exidx section, if there is one.
1757 Exidx_section_map exidx_section_map_;
1758 // Whether output local symbol count needs updating.
1759 bool output_local_symbol_count_needs_update_;
1760 // Whether we merge processor flags and attributes of this object to
1761 // output.
1762 bool merge_flags_and_attributes_;
1763 };
1764
1765 // Arm_dynobj class.
1766
1767 template<bool big_endian>
1768 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1769 {
1770 public:
1771 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1772 const elfcpp::Ehdr<32, big_endian>& ehdr)
1773 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1774 processor_specific_flags_(0), attributes_section_data_(NULL)
1775 { }
1776
1777 ~Arm_dynobj()
1778 { delete this->attributes_section_data_; }
1779
1780 // Downcast a base pointer to an Arm_relobj pointer. This is
1781 // not type-safe but we only use Arm_relobj not the base class.
1782 static Arm_dynobj<big_endian>*
1783 as_arm_dynobj(Dynobj* dynobj)
1784 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1785
1786 // Processor-specific flags in ELF file header. This is valid only after
1787 // reading symbols.
1788 elfcpp::Elf_Word
1789 processor_specific_flags() const
1790 { return this->processor_specific_flags_; }
1791
1792 // Attributes section data.
1793 const Attributes_section_data*
1794 attributes_section_data() const
1795 { return this->attributes_section_data_; }
1796
1797 protected:
1798 // Read the symbol information.
1799 void
1800 do_read_symbols(Read_symbols_data* sd);
1801
1802 private:
1803 // processor-specific flags in ELF file header.
1804 elfcpp::Elf_Word processor_specific_flags_;
1805 // Object attributes if there is an .ARM.attributes section or NULL.
1806 Attributes_section_data* attributes_section_data_;
1807 };
1808
1809 // Functor to read reloc addends during stub generation.
1810
1811 template<int sh_type, bool big_endian>
1812 struct Stub_addend_reader
1813 {
1814 // Return the addend for a relocation of a particular type. Depending
1815 // on whether this is a REL or RELA relocation, read the addend from a
1816 // view or from a Reloc object.
1817 elfcpp::Elf_types<32>::Elf_Swxword
1818 operator()(
1819 unsigned int /* r_type */,
1820 const unsigned char* /* view */,
1821 const typename Reloc_types<sh_type,
1822 32, big_endian>::Reloc& /* reloc */) const;
1823 };
1824
1825 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1826
1827 template<bool big_endian>
1828 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1829 {
1830 elfcpp::Elf_types<32>::Elf_Swxword
1831 operator()(
1832 unsigned int,
1833 const unsigned char*,
1834 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1835 };
1836
1837 // Specialized Stub_addend_reader for RELA type relocation sections.
1838 // We currently do not handle RELA type relocation sections but it is trivial
1839 // to implement the addend reader. This is provided for completeness and to
1840 // make it easier to add support for RELA relocation sections in the future.
1841
1842 template<bool big_endian>
1843 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1844 {
1845 elfcpp::Elf_types<32>::Elf_Swxword
1846 operator()(
1847 unsigned int,
1848 const unsigned char*,
1849 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1850 big_endian>::Reloc& reloc) const
1851 { return reloc.get_r_addend(); }
1852 };
1853
1854 // Cortex_a8_reloc class. We keep record of relocation that may need
1855 // the Cortex-A8 erratum workaround.
1856
1857 class Cortex_a8_reloc
1858 {
1859 public:
1860 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1861 Arm_address destination)
1862 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1863 { }
1864
1865 ~Cortex_a8_reloc()
1866 { }
1867
1868 // Accessors: This is a read-only class.
1869
1870 // Return the relocation stub associated with this relocation if there is
1871 // one.
1872 const Reloc_stub*
1873 reloc_stub() const
1874 { return this->reloc_stub_; }
1875
1876 // Return the relocation type.
1877 unsigned int
1878 r_type() const
1879 { return this->r_type_; }
1880
1881 // Return the destination address of the relocation. LSB stores the THUMB
1882 // bit.
1883 Arm_address
1884 destination() const
1885 { return this->destination_; }
1886
1887 private:
1888 // Associated relocation stub if there is one, or NULL.
1889 const Reloc_stub* reloc_stub_;
1890 // Relocation type.
1891 unsigned int r_type_;
1892 // Destination address of this relocation. LSB is used to distinguish
1893 // ARM/THUMB mode.
1894 Arm_address destination_;
1895 };
1896
1897 // Arm_output_data_got class. We derive this from Output_data_got to add
1898 // extra methods to handle TLS relocations in a static link.
1899
1900 template<bool big_endian>
1901 class Arm_output_data_got : public Output_data_got<32, big_endian>
1902 {
1903 public:
1904 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1905 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1906 { }
1907
1908 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1909 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1910 // applied in a static link.
1911 void
1912 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1913 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1914
1915 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1916 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1917 // relocation that needs to be applied in a static link.
1918 void
1919 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1920 Sized_relobj_file<32, big_endian>* relobj,
1921 unsigned int index)
1922 {
1923 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1924 index));
1925 }
1926
1927 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1928 // The first one is initialized to be 1, which is the module index for
1929 // the main executable and the second one 0. A reloc of the type
1930 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1931 // be applied by gold. GSYM is a global symbol.
1932 void
1933 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1934
1935 // Same as the above but for a local symbol in OBJECT with INDEX.
1936 void
1937 add_tls_gd32_with_static_reloc(unsigned int got_type,
1938 Sized_relobj_file<32, big_endian>* object,
1939 unsigned int index);
1940
1941 protected:
1942 // Write out the GOT table.
1943 void
1944 do_write(Output_file*);
1945
1946 private:
1947 // This class represent dynamic relocations that need to be applied by
1948 // gold because we are using TLS relocations in a static link.
1949 class Static_reloc
1950 {
1951 public:
1952 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1953 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1954 { this->u_.global.symbol = gsym; }
1955
1956 Static_reloc(unsigned int got_offset, unsigned int r_type,
1957 Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1958 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1959 {
1960 this->u_.local.relobj = relobj;
1961 this->u_.local.index = index;
1962 }
1963
1964 // Return the GOT offset.
1965 unsigned int
1966 got_offset() const
1967 { return this->got_offset_; }
1968
1969 // Relocation type.
1970 unsigned int
1971 r_type() const
1972 { return this->r_type_; }
1973
1974 // Whether the symbol is global or not.
1975 bool
1976 symbol_is_global() const
1977 { return this->symbol_is_global_; }
1978
1979 // For a relocation against a global symbol, the global symbol.
1980 Symbol*
1981 symbol() const
1982 {
1983 gold_assert(this->symbol_is_global_);
1984 return this->u_.global.symbol;
1985 }
1986
1987 // For a relocation against a local symbol, the defining object.
1988 Sized_relobj_file<32, big_endian>*
1989 relobj() const
1990 {
1991 gold_assert(!this->symbol_is_global_);
1992 return this->u_.local.relobj;
1993 }
1994
1995 // For a relocation against a local symbol, the local symbol index.
1996 unsigned int
1997 index() const
1998 {
1999 gold_assert(!this->symbol_is_global_);
2000 return this->u_.local.index;
2001 }
2002
2003 private:
2004 // GOT offset of the entry to which this relocation is applied.
2005 unsigned int got_offset_;
2006 // Type of relocation.
2007 unsigned int r_type_;
2008 // Whether this relocation is against a global symbol.
2009 bool symbol_is_global_;
2010 // A global or local symbol.
2011 union
2012 {
2013 struct
2014 {
2015 // For a global symbol, the symbol itself.
2016 Symbol* symbol;
2017 } global;
2018 struct
2019 {
2020 // For a local symbol, the object defining object.
2021 Sized_relobj_file<32, big_endian>* relobj;
2022 // For a local symbol, the symbol index.
2023 unsigned int index;
2024 } local;
2025 } u_;
2026 };
2027
2028 // Symbol table of the output object.
2029 Symbol_table* symbol_table_;
2030 // Layout of the output object.
2031 Layout* layout_;
2032 // Static relocs to be applied to the GOT.
2033 std::vector<Static_reloc> static_relocs_;
2034 };
2035
2036 // The ARM target has many relocation types with odd-sizes or noncontiguous
2037 // bits. The default handling of relocatable relocation cannot process these
2038 // relocations. So we have to extend the default code.
2039
2040 template<bool big_endian, int sh_type, typename Classify_reloc>
2041 class Arm_scan_relocatable_relocs :
2042 public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2043 {
2044 public:
2045 // Return the strategy to use for a local symbol which is a section
2046 // symbol, given the relocation type.
2047 inline Relocatable_relocs::Reloc_strategy
2048 local_section_strategy(unsigned int r_type, Relobj*)
2049 {
2050 if (sh_type == elfcpp::SHT_RELA)
2051 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2052 else
2053 {
2054 if (r_type == elfcpp::R_ARM_TARGET1
2055 || r_type == elfcpp::R_ARM_TARGET2)
2056 {
2057 const Target_arm<big_endian>* arm_target =
2058 Target_arm<big_endian>::default_target();
2059 r_type = arm_target->get_real_reloc_type(r_type);
2060 }
2061
2062 switch(r_type)
2063 {
2064 // Relocations that write nothing. These exclude R_ARM_TARGET1
2065 // and R_ARM_TARGET2.
2066 case elfcpp::R_ARM_NONE:
2067 case elfcpp::R_ARM_V4BX:
2068 case elfcpp::R_ARM_TLS_GOTDESC:
2069 case elfcpp::R_ARM_TLS_CALL:
2070 case elfcpp::R_ARM_TLS_DESCSEQ:
2071 case elfcpp::R_ARM_THM_TLS_CALL:
2072 case elfcpp::R_ARM_GOTRELAX:
2073 case elfcpp::R_ARM_GNU_VTENTRY:
2074 case elfcpp::R_ARM_GNU_VTINHERIT:
2075 case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2076 case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2077 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2078 // These should have been converted to something else above.
2079 case elfcpp::R_ARM_TARGET1:
2080 case elfcpp::R_ARM_TARGET2:
2081 gold_unreachable();
2082 // Relocations that write full 32 bits and
2083 // have alignment of 1.
2084 case elfcpp::R_ARM_ABS32:
2085 case elfcpp::R_ARM_REL32:
2086 case elfcpp::R_ARM_SBREL32:
2087 case elfcpp::R_ARM_GOTOFF32:
2088 case elfcpp::R_ARM_BASE_PREL:
2089 case elfcpp::R_ARM_GOT_BREL:
2090 case elfcpp::R_ARM_BASE_ABS:
2091 case elfcpp::R_ARM_ABS32_NOI:
2092 case elfcpp::R_ARM_REL32_NOI:
2093 case elfcpp::R_ARM_PLT32_ABS:
2094 case elfcpp::R_ARM_GOT_ABS:
2095 case elfcpp::R_ARM_GOT_PREL:
2096 case elfcpp::R_ARM_TLS_GD32:
2097 case elfcpp::R_ARM_TLS_LDM32:
2098 case elfcpp::R_ARM_TLS_LDO32:
2099 case elfcpp::R_ARM_TLS_IE32:
2100 case elfcpp::R_ARM_TLS_LE32:
2101 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2102 default:
2103 // For all other static relocations, return RELOC_SPECIAL.
2104 return Relocatable_relocs::RELOC_SPECIAL;
2105 }
2106 }
2107 }
2108 };
2109
2110 template<bool big_endian>
2111 class Target_arm : public Sized_target<32, big_endian>
2112 {
2113 public:
2114 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2115 Reloc_section;
2116
2117 // When were are relocating a stub, we pass this as the relocation number.
2118 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2119
2120 Target_arm(const Target::Target_info* info = &arm_info)
2121 : Sized_target<32, big_endian>(info),
2122 got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
2123 rel_dyn_(NULL), rel_irelative_(NULL), copy_relocs_(elfcpp::R_ARM_COPY),
2124 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2125 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2126 should_force_pic_veneer_(false),
2127 arm_input_section_map_(), attributes_section_data_(NULL),
2128 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2129 { }
2130
2131 // Whether we force PCI branch veneers.
2132 bool
2133 should_force_pic_veneer() const
2134 { return this->should_force_pic_veneer_; }
2135
2136 // Set PIC veneer flag.
2137 void
2138 set_should_force_pic_veneer(bool value)
2139 { this->should_force_pic_veneer_ = value; }
2140
2141 // Whether we use THUMB-2 instructions.
2142 bool
2143 using_thumb2() const
2144 {
2145 Object_attribute* attr =
2146 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2147 int arch = attr->int_value();
2148 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2149 }
2150
2151 // Whether we use THUMB/THUMB-2 instructions only.
2152 bool
2153 using_thumb_only() const
2154 {
2155 Object_attribute* attr =
2156 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2157
2158 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2159 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2160 return true;
2161 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2162 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2163 return false;
2164 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2165 return attr->int_value() == 'M';
2166 }
2167
2168 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2169 bool
2170 may_use_arm_nop() const
2171 {
2172 Object_attribute* attr =
2173 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2174 int arch = attr->int_value();
2175 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2176 || arch == elfcpp::TAG_CPU_ARCH_V6K
2177 || arch == elfcpp::TAG_CPU_ARCH_V7
2178 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2179 }
2180
2181 // Whether we have THUMB-2 NOP.W instruction.
2182 bool
2183 may_use_thumb2_nop() const
2184 {
2185 Object_attribute* attr =
2186 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2187 int arch = attr->int_value();
2188 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2189 || arch == elfcpp::TAG_CPU_ARCH_V7
2190 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2191 }
2192
2193 // Whether we have v4T interworking instructions available.
2194 bool
2195 may_use_v4t_interworking() const
2196 {
2197 Object_attribute* attr =
2198 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2199 int arch = attr->int_value();
2200 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2201 && arch != elfcpp::TAG_CPU_ARCH_V4);
2202 }
2203
2204 // Whether we have v5T interworking instructions available.
2205 bool
2206 may_use_v5t_interworking() const
2207 {
2208 Object_attribute* attr =
2209 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2210 int arch = attr->int_value();
2211 if (parameters->options().fix_arm1176())
2212 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2213 || arch == elfcpp::TAG_CPU_ARCH_V7
2214 || arch == elfcpp::TAG_CPU_ARCH_V6_M
2215 || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2216 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2217 else
2218 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2219 && arch != elfcpp::TAG_CPU_ARCH_V4
2220 && arch != elfcpp::TAG_CPU_ARCH_V4T);
2221 }
2222
2223 // Process the relocations to determine unreferenced sections for
2224 // garbage collection.
2225 void
2226 gc_process_relocs(Symbol_table* symtab,
2227 Layout* layout,
2228 Sized_relobj_file<32, big_endian>* object,
2229 unsigned int data_shndx,
2230 unsigned int sh_type,
2231 const unsigned char* prelocs,
2232 size_t reloc_count,
2233 Output_section* output_section,
2234 bool needs_special_offset_handling,
2235 size_t local_symbol_count,
2236 const unsigned char* plocal_symbols);
2237
2238 // Scan the relocations to look for symbol adjustments.
2239 void
2240 scan_relocs(Symbol_table* symtab,
2241 Layout* layout,
2242 Sized_relobj_file<32, big_endian>* object,
2243 unsigned int data_shndx,
2244 unsigned int sh_type,
2245 const unsigned char* prelocs,
2246 size_t reloc_count,
2247 Output_section* output_section,
2248 bool needs_special_offset_handling,
2249 size_t local_symbol_count,
2250 const unsigned char* plocal_symbols);
2251
2252 // Finalize the sections.
2253 void
2254 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2255
2256 // Return the value to use for a dynamic symbol which requires special
2257 // treatment.
2258 uint64_t
2259 do_dynsym_value(const Symbol*) const;
2260
2261 // Return the plt address for globals. Since we have irelative plt entries,
2262 // address calculation is not as straightforward as plt_address + plt_offset.
2263 uint64_t
2264 do_plt_address_for_global(const Symbol* gsym) const
2265 { return this->plt_section()->address_for_global(gsym); }
2266
2267 // Return the plt address for locals. Since we have irelative plt entries,
2268 // address calculation is not as straightforward as plt_address + plt_offset.
2269 uint64_t
2270 do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
2271 { return this->plt_section()->address_for_local(relobj, symndx); }
2272
2273 // Relocate a section.
2274 void
2275 relocate_section(const Relocate_info<32, big_endian>*,
2276 unsigned int sh_type,
2277 const unsigned char* prelocs,
2278 size_t reloc_count,
2279 Output_section* output_section,
2280 bool needs_special_offset_handling,
2281 unsigned char* view,
2282 Arm_address view_address,
2283 section_size_type view_size,
2284 const Reloc_symbol_changes*);
2285
2286 // Scan the relocs during a relocatable link.
2287 void
2288 scan_relocatable_relocs(Symbol_table* symtab,
2289 Layout* layout,
2290 Sized_relobj_file<32, big_endian>* object,
2291 unsigned int data_shndx,
2292 unsigned int sh_type,
2293 const unsigned char* prelocs,
2294 size_t reloc_count,
2295 Output_section* output_section,
2296 bool needs_special_offset_handling,
2297 size_t local_symbol_count,
2298 const unsigned char* plocal_symbols,
2299 Relocatable_relocs*);
2300
2301 // Emit relocations for a section.
2302 void
2303 relocate_relocs(const Relocate_info<32, big_endian>*,
2304 unsigned int sh_type,
2305 const unsigned char* prelocs,
2306 size_t reloc_count,
2307 Output_section* output_section,
2308 typename elfcpp::Elf_types<32>::Elf_Off
2309 offset_in_output_section,
2310 const Relocatable_relocs*,
2311 unsigned char* view,
2312 Arm_address view_address,
2313 section_size_type view_size,
2314 unsigned char* reloc_view,
2315 section_size_type reloc_view_size);
2316
2317 // Perform target-specific processing in a relocatable link. This is
2318 // only used if we use the relocation strategy RELOC_SPECIAL.
2319 void
2320 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2321 unsigned int sh_type,
2322 const unsigned char* preloc_in,
2323 size_t relnum,
2324 Output_section* output_section,
2325 typename elfcpp::Elf_types<32>::Elf_Off
2326 offset_in_output_section,
2327 unsigned char* view,
2328 typename elfcpp::Elf_types<32>::Elf_Addr
2329 view_address,
2330 section_size_type view_size,
2331 unsigned char* preloc_out);
2332
2333 // Return whether SYM is defined by the ABI.
2334 bool
2335 do_is_defined_by_abi(const Symbol* sym) const
2336 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2337
2338 // Return whether there is a GOT section.
2339 bool
2340 has_got_section() const
2341 { return this->got_ != NULL; }
2342
2343 // Return the size of the GOT section.
2344 section_size_type
2345 got_size() const
2346 {
2347 gold_assert(this->got_ != NULL);
2348 return this->got_->data_size();
2349 }
2350
2351 // Return the number of entries in the GOT.
2352 unsigned int
2353 got_entry_count() const
2354 {
2355 if (!this->has_got_section())
2356 return 0;
2357 return this->got_size() / 4;
2358 }
2359
2360 // Return the number of entries in the PLT.
2361 unsigned int
2362 plt_entry_count() const;
2363
2364 // Return the offset of the first non-reserved PLT entry.
2365 unsigned int
2366 first_plt_entry_offset() const;
2367
2368 // Return the size of each PLT entry.
2369 unsigned int
2370 plt_entry_size() const;
2371
2372 // Get the section to use for IRELATIVE relocations, create it if necessary.
2373 Reloc_section*
2374 rel_irelative_section(Layout*);
2375
2376 // Map platform-specific reloc types
2377 static unsigned int
2378 get_real_reloc_type(unsigned int r_type);
2379
2380 //
2381 // Methods to support stub-generations.
2382 //
2383
2384 // Return the stub factory
2385 const Stub_factory&
2386 stub_factory() const
2387 { return this->stub_factory_; }
2388
2389 // Make a new Arm_input_section object.
2390 Arm_input_section<big_endian>*
2391 new_arm_input_section(Relobj*, unsigned int);
2392
2393 // Find the Arm_input_section object corresponding to the SHNDX-th input
2394 // section of RELOBJ.
2395 Arm_input_section<big_endian>*
2396 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2397
2398 // Make a new Stub_table
2399 Stub_table<big_endian>*
2400 new_stub_table(Arm_input_section<big_endian>*);
2401
2402 // Scan a section for stub generation.
2403 void
2404 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2405 const unsigned char*, size_t, Output_section*,
2406 bool, const unsigned char*, Arm_address,
2407 section_size_type);
2408
2409 // Relocate a stub.
2410 void
2411 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2412 Output_section*, unsigned char*, Arm_address,
2413 section_size_type);
2414
2415 // Get the default ARM target.
2416 static Target_arm<big_endian>*
2417 default_target()
2418 {
2419 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2420 && parameters->target().is_big_endian() == big_endian);
2421 return static_cast<Target_arm<big_endian>*>(
2422 parameters->sized_target<32, big_endian>());
2423 }
2424
2425 // Whether NAME belongs to a mapping symbol.
2426 static bool
2427 is_mapping_symbol_name(const char* name)
2428 {
2429 return (name
2430 && name[0] == '$'
2431 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2432 && (name[2] == '\0' || name[2] == '.'));
2433 }
2434
2435 // Whether we work around the Cortex-A8 erratum.
2436 bool
2437 fix_cortex_a8() const
2438 { return this->fix_cortex_a8_; }
2439
2440 // Whether we merge exidx entries in debuginfo.
2441 bool
2442 merge_exidx_entries() const
2443 { return parameters->options().merge_exidx_entries(); }
2444
2445 // Whether we fix R_ARM_V4BX relocation.
2446 // 0 - do not fix
2447 // 1 - replace with MOV instruction (armv4 target)
2448 // 2 - make interworking veneer (>= armv4t targets only)
2449 General_options::Fix_v4bx
2450 fix_v4bx() const
2451 { return parameters->options().fix_v4bx(); }
2452
2453 // Scan a span of THUMB code section for Cortex-A8 erratum.
2454 void
2455 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2456 section_size_type, section_size_type,
2457 const unsigned char*, Arm_address);
2458
2459 // Apply Cortex-A8 workaround to a branch.
2460 void
2461 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2462 unsigned char*, Arm_address);
2463
2464 protected:
2465 // Make the PLT-generator object.
2466 Output_data_plt_arm<big_endian>*
2467 make_data_plt(Layout* layout,
2468 Arm_output_data_got<big_endian>* got,
2469 Output_data_space* got_plt,
2470 Output_data_space* got_irelative)
2471 { return this->do_make_data_plt(layout, got, got_plt, got_irelative); }
2472
2473 // Make an ELF object.
2474 Object*
2475 do_make_elf_object(const std::string&, Input_file*, off_t,
2476 const elfcpp::Ehdr<32, big_endian>& ehdr);
2477
2478 Object*
2479 do_make_elf_object(const std::string&, Input_file*, off_t,
2480 const elfcpp::Ehdr<32, !big_endian>&)
2481 { gold_unreachable(); }
2482
2483 Object*
2484 do_make_elf_object(const std::string&, Input_file*, off_t,
2485 const elfcpp::Ehdr<64, false>&)
2486 { gold_unreachable(); }
2487
2488 Object*
2489 do_make_elf_object(const std::string&, Input_file*, off_t,
2490 const elfcpp::Ehdr<64, true>&)
2491 { gold_unreachable(); }
2492
2493 // Make an output section.
2494 Output_section*
2495 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2496 elfcpp::Elf_Xword flags)
2497 { return new Arm_output_section<big_endian>(name, type, flags); }
2498
2499 void
2500 do_adjust_elf_header(unsigned char* view, int len);
2501
2502 // We only need to generate stubs, and hence perform relaxation if we are
2503 // not doing relocatable linking.
2504 bool
2505 do_may_relax() const
2506 { return !parameters->options().relocatable(); }
2507
2508 bool
2509 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2510
2511 // Determine whether an object attribute tag takes an integer, a
2512 // string or both.
2513 int
2514 do_attribute_arg_type(int tag) const;
2515
2516 // Reorder tags during output.
2517 int
2518 do_attributes_order(int num) const;
2519
2520 // This is called when the target is selected as the default.
2521 void
2522 do_select_as_default_target()
2523 {
2524 // No locking is required since there should only be one default target.
2525 // We cannot have both the big-endian and little-endian ARM targets
2526 // as the default.
2527 gold_assert(arm_reloc_property_table == NULL);
2528 arm_reloc_property_table = new Arm_reloc_property_table();
2529 }
2530
2531 // Virtual function which is set to return true by a target if
2532 // it can use relocation types to determine if a function's
2533 // pointer is taken.
2534 virtual bool
2535 do_can_check_for_function_pointers() const
2536 { return true; }
2537
2538 // Whether a section called SECTION_NAME may have function pointers to
2539 // sections not eligible for safe ICF folding.
2540 virtual bool
2541 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2542 {
2543 return (!is_prefix_of(".ARM.exidx", section_name)
2544 && !is_prefix_of(".ARM.extab", section_name)
2545 && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2546 }
2547
2548 virtual void
2549 do_define_standard_symbols(Symbol_table*, Layout*);
2550
2551 virtual Output_data_plt_arm<big_endian>*
2552 do_make_data_plt(Layout* layout,
2553 Arm_output_data_got<big_endian>* got,
2554 Output_data_space* got_plt,
2555 Output_data_space* got_irelative)
2556 {
2557 gold_assert(got_plt != NULL && got_irelative != NULL);
2558 return new Output_data_plt_arm_standard<big_endian>(
2559 layout, got, got_plt, got_irelative);
2560 }
2561
2562 private:
2563 // The class which scans relocations.
2564 class Scan
2565 {
2566 public:
2567 Scan()
2568 : issued_non_pic_error_(false)
2569 { }
2570
2571 static inline int
2572 get_reference_flags(unsigned int r_type);
2573
2574 inline void
2575 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2576 Sized_relobj_file<32, big_endian>* object,
2577 unsigned int data_shndx,
2578 Output_section* output_section,
2579 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2580 const elfcpp::Sym<32, big_endian>& lsym,
2581 bool is_discarded);
2582
2583 inline void
2584 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2585 Sized_relobj_file<32, big_endian>* object,
2586 unsigned int data_shndx,
2587 Output_section* output_section,
2588 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2589 Symbol* gsym);
2590
2591 inline bool
2592 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2593 Sized_relobj_file<32, big_endian>* ,
2594 unsigned int ,
2595 Output_section* ,
2596 const elfcpp::Rel<32, big_endian>& ,
2597 unsigned int ,
2598 const elfcpp::Sym<32, big_endian>&);
2599
2600 inline bool
2601 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2602 Sized_relobj_file<32, big_endian>* ,
2603 unsigned int ,
2604 Output_section* ,
2605 const elfcpp::Rel<32, big_endian>& ,
2606 unsigned int , Symbol*);
2607
2608 private:
2609 static void
2610 unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2611 unsigned int r_type);
2612
2613 static void
2614 unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2615 unsigned int r_type, Symbol*);
2616
2617 void
2618 check_non_pic(Relobj*, unsigned int r_type);
2619
2620 // Almost identical to Symbol::needs_plt_entry except that it also
2621 // handles STT_ARM_TFUNC.
2622 static bool
2623 symbol_needs_plt_entry(const Symbol* sym)
2624 {
2625 // An undefined symbol from an executable does not need a PLT entry.
2626 if (sym->is_undefined() && !parameters->options().shared())
2627 return false;
2628
2629 if (sym->type() == elfcpp::STT_GNU_IFUNC)
2630 return true;
2631
2632 return (!parameters->doing_static_link()
2633 && (sym->type() == elfcpp::STT_FUNC
2634 || sym->type() == elfcpp::STT_ARM_TFUNC)
2635 && (sym->is_from_dynobj()
2636 || sym->is_undefined()
2637 || sym->is_preemptible()));
2638 }
2639
2640 inline bool
2641 possible_function_pointer_reloc(unsigned int r_type);
2642
2643 // Whether a plt entry is needed for ifunc.
2644 bool
2645 reloc_needs_plt_for_ifunc(Sized_relobj_file<32, big_endian>*,
2646 unsigned int r_type);
2647
2648 // Whether we have issued an error about a non-PIC compilation.
2649 bool issued_non_pic_error_;
2650 };
2651
2652 // The class which implements relocation.
2653 class Relocate
2654 {
2655 public:
2656 Relocate()
2657 { }
2658
2659 ~Relocate()
2660 { }
2661
2662 // Return whether the static relocation needs to be applied.
2663 inline bool
2664 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2665 unsigned int r_type,
2666 bool is_32bit,
2667 Output_section* output_section);
2668
2669 // Do a relocation. Return false if the caller should not issue
2670 // any warnings about this relocation.
2671 inline bool
2672 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2673 Output_section*, size_t relnum,
2674 const elfcpp::Rel<32, big_endian>&,
2675 unsigned int r_type, const Sized_symbol<32>*,
2676 const Symbol_value<32>*,
2677 unsigned char*, Arm_address,
2678 section_size_type);
2679
2680 // Return whether we want to pass flag NON_PIC_REF for this
2681 // reloc. This means the relocation type accesses a symbol not via
2682 // GOT or PLT.
2683 static inline bool
2684 reloc_is_non_pic(unsigned int r_type)
2685 {
2686 switch (r_type)
2687 {
2688 // These relocation types reference GOT or PLT entries explicitly.
2689 case elfcpp::R_ARM_GOT_BREL:
2690 case elfcpp::R_ARM_GOT_ABS:
2691 case elfcpp::R_ARM_GOT_PREL:
2692 case elfcpp::R_ARM_GOT_BREL12:
2693 case elfcpp::R_ARM_PLT32_ABS:
2694 case elfcpp::R_ARM_TLS_GD32:
2695 case elfcpp::R_ARM_TLS_LDM32:
2696 case elfcpp::R_ARM_TLS_IE32:
2697 case elfcpp::R_ARM_TLS_IE12GP:
2698
2699 // These relocate types may use PLT entries.
2700 case elfcpp::R_ARM_CALL:
2701 case elfcpp::R_ARM_THM_CALL:
2702 case elfcpp::R_ARM_JUMP24:
2703 case elfcpp::R_ARM_THM_JUMP24:
2704 case elfcpp::R_ARM_THM_JUMP19:
2705 case elfcpp::R_ARM_PLT32:
2706 case elfcpp::R_ARM_THM_XPC22:
2707 case elfcpp::R_ARM_PREL31:
2708 case elfcpp::R_ARM_SBREL31:
2709 return false;
2710
2711 default:
2712 return true;
2713 }
2714 }
2715
2716 private:
2717 // Do a TLS relocation.
2718 inline typename Arm_relocate_functions<big_endian>::Status
2719 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2720 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2721 const Sized_symbol<32>*, const Symbol_value<32>*,
2722 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2723 section_size_type);
2724
2725 };
2726
2727 // A class which returns the size required for a relocation type,
2728 // used while scanning relocs during a relocatable link.
2729 class Relocatable_size_for_reloc
2730 {
2731 public:
2732 unsigned int
2733 get_size_for_reloc(unsigned int, Relobj*);
2734 };
2735
2736 // Adjust TLS relocation type based on the options and whether this
2737 // is a local symbol.
2738 static tls::Tls_optimization
2739 optimize_tls_reloc(bool is_final, int r_type);
2740
2741 // Get the GOT section, creating it if necessary.
2742 Arm_output_data_got<big_endian>*
2743 got_section(Symbol_table*, Layout*);
2744
2745 // Get the GOT PLT section.
2746 Output_data_space*
2747 got_plt_section() const
2748 {
2749 gold_assert(this->got_plt_ != NULL);
2750 return this->got_plt_;
2751 }
2752
2753 // Create the PLT section.
2754 void
2755 make_plt_section(Symbol_table* symtab, Layout* layout);
2756
2757 // Create a PLT entry for a global symbol.
2758 void
2759 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2760
2761 // Create a PLT entry for a local STT_GNU_IFUNC symbol.
2762 void
2763 make_local_ifunc_plt_entry(Symbol_table*, Layout*,
2764 Sized_relobj_file<32, big_endian>* relobj,
2765 unsigned int local_sym_index);
2766
2767 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2768 void
2769 define_tls_base_symbol(Symbol_table*, Layout*);
2770
2771 // Create a GOT entry for the TLS module index.
2772 unsigned int
2773 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2774 Sized_relobj_file<32, big_endian>* object);
2775
2776 // Get the PLT section.
2777 const Output_data_plt_arm<big_endian>*
2778 plt_section() const
2779 {
2780 gold_assert(this->plt_ != NULL);
2781 return this->plt_;
2782 }
2783
2784 // Get the dynamic reloc section, creating it if necessary.
2785 Reloc_section*
2786 rel_dyn_section(Layout*);
2787
2788 // Get the section to use for TLS_DESC relocations.
2789 Reloc_section*
2790 rel_tls_desc_section(Layout*) const;
2791
2792 // Return true if the symbol may need a COPY relocation.
2793 // References from an executable object to non-function symbols
2794 // defined in a dynamic object may need a COPY relocation.
2795 bool
2796 may_need_copy_reloc(Symbol* gsym)
2797 {
2798 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2799 && gsym->may_need_copy_reloc());
2800 }
2801
2802 // Add a potential copy relocation.
2803 void
2804 copy_reloc(Symbol_table* symtab, Layout* layout,
2805 Sized_relobj_file<32, big_endian>* object,
2806 unsigned int shndx, Output_section* output_section,
2807 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2808 {
2809 this->copy_relocs_.copy_reloc(symtab, layout,
2810 symtab->get_sized_symbol<32>(sym),
2811 object, shndx, output_section, reloc,
2812 this->rel_dyn_section(layout));
2813 }
2814
2815 // Whether two EABI versions are compatible.
2816 static bool
2817 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2818
2819 // Merge processor-specific flags from input object and those in the ELF
2820 // header of the output.
2821 void
2822 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2823
2824 // Get the secondary compatible architecture.
2825 static int
2826 get_secondary_compatible_arch(const Attributes_section_data*);
2827
2828 // Set the secondary compatible architecture.
2829 static void
2830 set_secondary_compatible_arch(Attributes_section_data*, int);
2831
2832 static int
2833 tag_cpu_arch_combine(const char*, int, int*, int, int);
2834
2835 // Helper to print AEABI enum tag value.
2836 static std::string
2837 aeabi_enum_name(unsigned int);
2838
2839 // Return string value for TAG_CPU_name.
2840 static std::string
2841 tag_cpu_name_value(unsigned int);
2842
2843 // Query attributes object to see if integer divide instructions may be
2844 // present in an object.
2845 static bool
2846 attributes_accept_div(int arch, int profile,
2847 const Object_attribute* div_attr);
2848
2849 // Query attributes object to see if integer divide instructions are
2850 // forbidden to be in the object. This is not the inverse of
2851 // attributes_accept_div.
2852 static bool
2853 attributes_forbid_div(const Object_attribute* div_attr);
2854
2855 // Merge object attributes from input object and those in the output.
2856 void
2857 merge_object_attributes(const char*, const Attributes_section_data*);
2858
2859 // Helper to get an AEABI object attribute
2860 Object_attribute*
2861 get_aeabi_object_attribute(int tag) const
2862 {
2863 Attributes_section_data* pasd = this->attributes_section_data_;
2864 gold_assert(pasd != NULL);
2865 Object_attribute* attr =
2866 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2867 gold_assert(attr != NULL);
2868 return attr;
2869 }
2870
2871 //
2872 // Methods to support stub-generations.
2873 //
2874
2875 // Group input sections for stub generation.
2876 void
2877 group_sections(Layout*, section_size_type, bool, const Task*);
2878
2879 // Scan a relocation for stub generation.
2880 void
2881 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2882 const Sized_symbol<32>*, unsigned int,
2883 const Symbol_value<32>*,
2884 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2885
2886 // Scan a relocation section for stub.
2887 template<int sh_type>
2888 void
2889 scan_reloc_section_for_stubs(
2890 const Relocate_info<32, big_endian>* relinfo,
2891 const unsigned char* prelocs,
2892 size_t reloc_count,
2893 Output_section* output_section,
2894 bool needs_special_offset_handling,
2895 const unsigned char* view,
2896 elfcpp::Elf_types<32>::Elf_Addr view_address,
2897 section_size_type);
2898
2899 // Fix .ARM.exidx section coverage.
2900 void
2901 fix_exidx_coverage(Layout*, const Input_objects*,
2902 Arm_output_section<big_endian>*, Symbol_table*,
2903 const Task*);
2904
2905 // Functors for STL set.
2906 struct output_section_address_less_than
2907 {
2908 bool
2909 operator()(const Output_section* s1, const Output_section* s2) const
2910 { return s1->address() < s2->address(); }
2911 };
2912
2913 // Information about this specific target which we pass to the
2914 // general Target structure.
2915 static const Target::Target_info arm_info;
2916
2917 // The types of GOT entries needed for this platform.
2918 // These values are exposed to the ABI in an incremental link.
2919 // Do not renumber existing values without changing the version
2920 // number of the .gnu_incremental_inputs section.
2921 enum Got_type
2922 {
2923 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2924 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2925 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2926 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2927 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2928 };
2929
2930 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2931
2932 // Map input section to Arm_input_section.
2933 typedef Unordered_map<Section_id,
2934 Arm_input_section<big_endian>*,
2935 Section_id_hash>
2936 Arm_input_section_map;
2937
2938 // Map output addresses to relocs for Cortex-A8 erratum.
2939 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2940 Cortex_a8_relocs_info;
2941
2942 // The GOT section.
2943 Arm_output_data_got<big_endian>* got_;
2944 // The PLT section.
2945 Output_data_plt_arm<big_endian>* plt_;
2946 // The GOT PLT section.
2947 Output_data_space* got_plt_;
2948 // The GOT section for IRELATIVE relocations.
2949 Output_data_space* got_irelative_;
2950 // The dynamic reloc section.
2951 Reloc_section* rel_dyn_;
2952 // The section to use for IRELATIVE relocs.
2953 Reloc_section* rel_irelative_;
2954 // Relocs saved to avoid a COPY reloc.
2955 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2956 // Offset of the GOT entry for the TLS module index.
2957 unsigned int got_mod_index_offset_;
2958 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2959 bool tls_base_symbol_defined_;
2960 // Vector of Stub_tables created.
2961 Stub_table_list stub_tables_;
2962 // Stub factory.
2963 const Stub_factory &stub_factory_;
2964 // Whether we force PIC branch veneers.
2965 bool should_force_pic_veneer_;
2966 // Map for locating Arm_input_sections.
2967 Arm_input_section_map arm_input_section_map_;
2968 // Attributes section data in output.
2969 Attributes_section_data* attributes_section_data_;
2970 // Whether we want to fix code for Cortex-A8 erratum.
2971 bool fix_cortex_a8_;
2972 // Map addresses to relocs for Cortex-A8 erratum.
2973 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2974 };
2975
2976 template<bool big_endian>
2977 const Target::Target_info Target_arm<big_endian>::arm_info =
2978 {
2979 32, // size
2980 big_endian, // is_big_endian
2981 elfcpp::EM_ARM, // machine_code
2982 false, // has_make_symbol
2983 false, // has_resolve
2984 false, // has_code_fill
2985 true, // is_default_stack_executable
2986 false, // can_icf_inline_merge_sections
2987 '\0', // wrap_char
2988 "/usr/lib/libc.so.1", // dynamic_linker
2989 0x8000, // default_text_segment_address
2990 0x1000, // abi_pagesize (overridable by -z max-page-size)
2991 0x1000, // common_pagesize (overridable by -z common-page-size)
2992 false, // isolate_execinstr
2993 0, // rosegment_gap
2994 elfcpp::SHN_UNDEF, // small_common_shndx
2995 elfcpp::SHN_UNDEF, // large_common_shndx
2996 0, // small_common_section_flags
2997 0, // large_common_section_flags
2998 ".ARM.attributes", // attributes_section
2999 "aeabi", // attributes_vendor
3000 "_start" // entry_symbol_name
3001 };
3002
3003 // Arm relocate functions class
3004 //
3005
3006 template<bool big_endian>
3007 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
3008 {
3009 public:
3010 typedef enum
3011 {
3012 STATUS_OKAY, // No error during relocation.
3013 STATUS_OVERFLOW, // Relocation overflow.
3014 STATUS_BAD_RELOC // Relocation cannot be applied.
3015 } Status;
3016
3017 private:
3018 typedef Relocate_functions<32, big_endian> Base;
3019 typedef Arm_relocate_functions<big_endian> This;
3020
3021 // Encoding of imm16 argument for movt and movw ARM instructions
3022 // from ARM ARM:
3023 //
3024 // imm16 := imm4 | imm12
3025 //
3026 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
3027 // +-------+---------------+-------+-------+-----------------------+
3028 // | | |imm4 | |imm12 |
3029 // +-------+---------------+-------+-------+-----------------------+
3030
3031 // Extract the relocation addend from VAL based on the ARM
3032 // instruction encoding described above.
3033 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3034 extract_arm_movw_movt_addend(
3035 typename elfcpp::Swap<32, big_endian>::Valtype val)
3036 {
3037 // According to the Elf ABI for ARM Architecture the immediate
3038 // field is sign-extended to form the addend.
3039 return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
3040 }
3041
3042 // Insert X into VAL based on the ARM instruction encoding described
3043 // above.
3044 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3045 insert_val_arm_movw_movt(
3046 typename elfcpp::Swap<32, big_endian>::Valtype val,
3047 typename elfcpp::Swap<32, big_endian>::Valtype x)
3048 {
3049 val &= 0xfff0f000;
3050 val |= x & 0x0fff;
3051 val |= (x & 0xf000) << 4;
3052 return val;
3053 }
3054
3055 // Encoding of imm16 argument for movt and movw Thumb2 instructions
3056 // from ARM ARM:
3057 //
3058 // imm16 := imm4 | i | imm3 | imm8
3059 //
3060 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
3061 // +---------+-+-----------+-------++-+-----+-------+---------------+
3062 // | |i| |imm4 || |imm3 | |imm8 |
3063 // +---------+-+-----------+-------++-+-----+-------+---------------+
3064
3065 // Extract the relocation addend from VAL based on the Thumb2
3066 // instruction encoding described above.
3067 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3068 extract_thumb_movw_movt_addend(
3069 typename elfcpp::Swap<32, big_endian>::Valtype val)
3070 {
3071 // According to the Elf ABI for ARM Architecture the immediate
3072 // field is sign-extended to form the addend.
3073 return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3074 | ((val >> 15) & 0x0800)
3075 | ((val >> 4) & 0x0700)
3076 | (val & 0x00ff));
3077 }
3078
3079 // Insert X into VAL based on the Thumb2 instruction encoding
3080 // described above.
3081 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3082 insert_val_thumb_movw_movt(
3083 typename elfcpp::Swap<32, big_endian>::Valtype val,
3084 typename elfcpp::Swap<32, big_endian>::Valtype x)
3085 {
3086 val &= 0xfbf08f00;
3087 val |= (x & 0xf000) << 4;
3088 val |= (x & 0x0800) << 15;
3089 val |= (x & 0x0700) << 4;
3090 val |= (x & 0x00ff);
3091 return val;
3092 }
3093
3094 // Calculate the smallest constant Kn for the specified residual.
3095 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3096 static uint32_t
3097 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3098 {
3099 int32_t msb;
3100
3101 if (residual == 0)
3102 return 0;
3103 // Determine the most significant bit in the residual and
3104 // align the resulting value to a 2-bit boundary.
3105 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3106 ;
3107 // The desired shift is now (msb - 6), or zero, whichever
3108 // is the greater.
3109 return (((msb - 6) < 0) ? 0 : (msb - 6));
3110 }
3111
3112 // Calculate the final residual for the specified group index.
3113 // If the passed group index is less than zero, the method will return
3114 // the value of the specified residual without any change.
3115 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3116 static typename elfcpp::Swap<32, big_endian>::Valtype
3117 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3118 const int group)
3119 {
3120 for (int n = 0; n <= group; n++)
3121 {
3122 // Calculate which part of the value to mask.
3123 uint32_t shift = calc_grp_kn(residual);
3124 // Calculate the residual for the next time around.
3125 residual &= ~(residual & (0xff << shift));
3126 }
3127
3128 return residual;
3129 }
3130
3131 // Calculate the value of Gn for the specified group index.
3132 // We return it in the form of an encoded constant-and-rotation.
3133 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3134 static typename elfcpp::Swap<32, big_endian>::Valtype
3135 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3136 const int group)
3137 {
3138 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3139 uint32_t shift = 0;
3140
3141 for (int n = 0; n <= group; n++)
3142 {
3143 // Calculate which part of the value to mask.
3144 shift = calc_grp_kn(residual);
3145 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3146 gn = residual & (0xff << shift);
3147 // Calculate the residual for the next time around.
3148 residual &= ~gn;
3149 }
3150 // Return Gn in the form of an encoded constant-and-rotation.
3151 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3152 }
3153
3154 public:
3155 // Handle ARM long branches.
3156 static typename This::Status
3157 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3158 unsigned char*, const Sized_symbol<32>*,
3159 const Arm_relobj<big_endian>*, unsigned int,
3160 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3161
3162 // Handle THUMB long branches.
3163 static typename This::Status
3164 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3165 unsigned char*, const Sized_symbol<32>*,
3166 const Arm_relobj<big_endian>*, unsigned int,
3167 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3168
3169
3170 // Return the branch offset of a 32-bit THUMB branch.
3171 static inline int32_t
3172 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3173 {
3174 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3175 // involving the J1 and J2 bits.
3176 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3177 uint32_t upper = upper_insn & 0x3ffU;
3178 uint32_t lower = lower_insn & 0x7ffU;
3179 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3180 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3181 uint32_t i1 = j1 ^ s ? 0 : 1;
3182 uint32_t i2 = j2 ^ s ? 0 : 1;
3183
3184 return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3185 | (upper << 12) | (lower << 1));
3186 }
3187
3188 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3189 // UPPER_INSN is the original upper instruction of the branch. Caller is
3190 // responsible for overflow checking and BLX offset adjustment.
3191 static inline uint16_t
3192 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3193 {
3194 uint32_t s = offset < 0 ? 1 : 0;
3195 uint32_t bits = static_cast<uint32_t>(offset);
3196 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3197 }
3198
3199 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3200 // LOWER_INSN is the original lower instruction of the branch. Caller is
3201 // responsible for overflow checking and BLX offset adjustment.
3202 static inline uint16_t
3203 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3204 {
3205 uint32_t s = offset < 0 ? 1 : 0;
3206 uint32_t bits = static_cast<uint32_t>(offset);
3207 return ((lower_insn & ~0x2fffU)
3208 | ((((bits >> 23) & 1) ^ !s) << 13)
3209 | ((((bits >> 22) & 1) ^ !s) << 11)
3210 | ((bits >> 1) & 0x7ffU));
3211 }
3212
3213 // Return the branch offset of a 32-bit THUMB conditional branch.
3214 static inline int32_t
3215 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3216 {
3217 uint32_t s = (upper_insn & 0x0400U) >> 10;
3218 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3219 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3220 uint32_t lower = (lower_insn & 0x07ffU);
3221 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3222
3223 return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3224 }
3225
3226 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3227 // instruction. UPPER_INSN is the original upper instruction of the branch.
3228 // Caller is responsible for overflow checking.
3229 static inline uint16_t
3230 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3231 {
3232 uint32_t s = offset < 0 ? 1 : 0;
3233 uint32_t bits = static_cast<uint32_t>(offset);
3234 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3235 }
3236
3237 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3238 // instruction. LOWER_INSN is the original lower instruction of the branch.
3239 // The caller is responsible for overflow checking.
3240 static inline uint16_t
3241 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3242 {
3243 uint32_t bits = static_cast<uint32_t>(offset);
3244 uint32_t j2 = (bits & 0x00080000U) >> 19;
3245 uint32_t j1 = (bits & 0x00040000U) >> 18;
3246 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3247
3248 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3249 }
3250
3251 // R_ARM_ABS8: S + A
3252 static inline typename This::Status
3253 abs8(unsigned char* view,
3254 const Sized_relobj_file<32, big_endian>* object,
3255 const Symbol_value<32>* psymval)
3256 {
3257 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3258 Valtype* wv = reinterpret_cast<Valtype*>(view);
3259 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3260 int32_t addend = Bits<8>::sign_extend32(val);
3261 Arm_address x = psymval->value(object, addend);
3262 val = Bits<32>::bit_select32(val, x, 0xffU);
3263 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3264
3265 // R_ARM_ABS8 permits signed or unsigned results.
3266 return (Bits<8>::has_signed_unsigned_overflow32(x)
3267 ? This::STATUS_OVERFLOW
3268 : This::STATUS_OKAY);
3269 }
3270
3271 // R_ARM_THM_ABS5: S + A
3272 static inline typename This::Status
3273 thm_abs5(unsigned char* view,
3274 const Sized_relobj_file<32, big_endian>* object,
3275 const Symbol_value<32>* psymval)
3276 {
3277 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3278 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3279 Valtype* wv = reinterpret_cast<Valtype*>(view);
3280 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3281 Reltype addend = (val & 0x7e0U) >> 6;
3282 Reltype x = psymval->value(object, addend);
3283 val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3284 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3285 return (Bits<5>::has_overflow32(x)
3286 ? This::STATUS_OVERFLOW
3287 : This::STATUS_OKAY);
3288 }
3289
3290 // R_ARM_ABS12: S + A
3291 static inline typename This::Status
3292 abs12(unsigned char* view,
3293 const Sized_relobj_file<32, big_endian>* object,
3294 const Symbol_value<32>* psymval)
3295 {
3296 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3297 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3298 Valtype* wv = reinterpret_cast<Valtype*>(view);
3299 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3300 Reltype addend = val & 0x0fffU;
3301 Reltype x = psymval->value(object, addend);
3302 val = Bits<32>::bit_select32(val, x, 0x0fffU);
3303 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3304 return (Bits<12>::has_overflow32(x)
3305 ? This::STATUS_OVERFLOW
3306 : This::STATUS_OKAY);
3307 }
3308
3309 // R_ARM_ABS16: S + A
3310 static inline typename This::Status
3311 abs16(unsigned char* view,
3312 const Sized_relobj_file<32, big_endian>* object,
3313 const Symbol_value<32>* psymval)
3314 {
3315 typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3316 Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3317 int32_t addend = Bits<16>::sign_extend32(val);
3318 Arm_address x = psymval->value(object, addend);
3319 val = Bits<32>::bit_select32(val, x, 0xffffU);
3320 elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3321
3322 // R_ARM_ABS16 permits signed or unsigned results.
3323 return (Bits<16>::has_signed_unsigned_overflow32(x)
3324 ? This::STATUS_OVERFLOW
3325 : This::STATUS_OKAY);
3326 }
3327
3328 // R_ARM_ABS32: (S + A) | T
3329 static inline typename This::Status
3330 abs32(unsigned char* view,
3331 const Sized_relobj_file<32, big_endian>* object,
3332 const Symbol_value<32>* psymval,
3333 Arm_address thumb_bit)
3334 {
3335 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3336 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3337 Valtype x = psymval->value(object, addend) | thumb_bit;
3338 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3339 return This::STATUS_OKAY;
3340 }
3341
3342 // R_ARM_REL32: (S + A) | T - P
3343 static inline typename This::Status
3344 rel32(unsigned char* view,
3345 const Sized_relobj_file<32, big_endian>* object,
3346 const Symbol_value<32>* psymval,
3347 Arm_address address,
3348 Arm_address thumb_bit)
3349 {
3350 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3351 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3352 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3353 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3354 return This::STATUS_OKAY;
3355 }
3356
3357 // R_ARM_THM_JUMP24: (S + A) | T - P
3358 static typename This::Status
3359 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3360 const Symbol_value<32>* psymval, Arm_address address,
3361 Arm_address thumb_bit);
3362
3363 // R_ARM_THM_JUMP6: S + A – P
3364 static inline typename This::Status
3365 thm_jump6(unsigned char* view,
3366 const Sized_relobj_file<32, big_endian>* object,
3367 const Symbol_value<32>* psymval,
3368 Arm_address address)
3369 {
3370 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3371 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3372 Valtype* wv = reinterpret_cast<Valtype*>(view);
3373 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3374 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3375 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3376 Reltype x = (psymval->value(object, addend) - address);
3377 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3378 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3379 // CZB does only forward jumps.
3380 return ((x > 0x007e)
3381 ? This::STATUS_OVERFLOW
3382 : This::STATUS_OKAY);
3383 }
3384
3385 // R_ARM_THM_JUMP8: S + A – P
3386 static inline typename This::Status
3387 thm_jump8(unsigned char* view,
3388 const Sized_relobj_file<32, big_endian>* object,
3389 const Symbol_value<32>* psymval,
3390 Arm_address address)
3391 {
3392 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3393 Valtype* wv = reinterpret_cast<Valtype*>(view);
3394 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3395 int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3396 int32_t x = (psymval->value(object, addend) - address);
3397 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3398 | ((x & 0x01fe) >> 1)));
3399 // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3400 return (Bits<9>::has_overflow32(x)
3401 ? This::STATUS_OVERFLOW
3402 : This::STATUS_OKAY);
3403 }
3404
3405 // R_ARM_THM_JUMP11: S + A – P
3406 static inline typename This::Status
3407 thm_jump11(unsigned char* view,
3408 const Sized_relobj_file<32, big_endian>* object,
3409 const Symbol_value<32>* psymval,
3410 Arm_address address)
3411 {
3412 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3413 Valtype* wv = reinterpret_cast<Valtype*>(view);
3414 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3415 int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3416 int32_t x = (psymval->value(object, addend) - address);
3417 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3418 | ((x & 0x0ffe) >> 1)));
3419 // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3420 return (Bits<12>::has_overflow32(x)
3421 ? This::STATUS_OVERFLOW
3422 : This::STATUS_OKAY);
3423 }
3424
3425 // R_ARM_BASE_PREL: B(S) + A - P
3426 static inline typename This::Status
3427 base_prel(unsigned char* view,
3428 Arm_address origin,
3429 Arm_address address)
3430 {
3431 Base::rel32(view, origin - address);
3432 return STATUS_OKAY;
3433 }
3434
3435 // R_ARM_BASE_ABS: B(S) + A
3436 static inline typename This::Status
3437 base_abs(unsigned char* view,
3438 Arm_address origin)
3439 {
3440 Base::rel32(view, origin);
3441 return STATUS_OKAY;
3442 }
3443
3444 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3445 static inline typename This::Status
3446 got_brel(unsigned char* view,
3447 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3448 {
3449 Base::rel32(view, got_offset);
3450 return This::STATUS_OKAY;
3451 }
3452
3453 // R_ARM_GOT_PREL: GOT(S) + A - P
3454 static inline typename This::Status
3455 got_prel(unsigned char* view,
3456 Arm_address got_entry,
3457 Arm_address address)
3458 {
3459 Base::rel32(view, got_entry - address);
3460 return This::STATUS_OKAY;
3461 }
3462
3463 // R_ARM_PREL: (S + A) | T - P
3464 static inline typename This::Status
3465 prel31(unsigned char* view,
3466 const Sized_relobj_file<32, big_endian>* object,
3467 const Symbol_value<32>* psymval,
3468 Arm_address address,
3469 Arm_address thumb_bit)
3470 {
3471 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3472 Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3473 Valtype addend = Bits<31>::sign_extend32(val);
3474 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3475 val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3476 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3477 return (Bits<31>::has_overflow32(x)
3478 ? This::STATUS_OVERFLOW
3479 : This::STATUS_OKAY);
3480 }
3481
3482 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3483 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3484 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3485 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3486 static inline typename This::Status
3487 movw(unsigned char* view,
3488 const Sized_relobj_file<32, big_endian>* object,
3489 const Symbol_value<32>* psymval,
3490 Arm_address relative_address_base,
3491 Arm_address thumb_bit,
3492 bool check_overflow)
3493 {
3494 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3495 Valtype* wv = reinterpret_cast<Valtype*>(view);
3496 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3497 Valtype addend = This::extract_arm_movw_movt_addend(val);
3498 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3499 - relative_address_base);
3500 val = This::insert_val_arm_movw_movt(val, x);
3501 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3502 return ((check_overflow && Bits<16>::has_overflow32(x))
3503 ? This::STATUS_OVERFLOW
3504 : This::STATUS_OKAY);
3505 }
3506
3507 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3508 // R_ARM_MOVT_PREL: S + A - P
3509 // R_ARM_MOVT_BREL: S + A - B(S)
3510 static inline typename This::Status
3511 movt(unsigned char* view,
3512 const Sized_relobj_file<32, big_endian>* object,
3513 const Symbol_value<32>* psymval,
3514 Arm_address relative_address_base)
3515 {
3516 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3517 Valtype* wv = reinterpret_cast<Valtype*>(view);
3518 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3519 Valtype addend = This::extract_arm_movw_movt_addend(val);
3520 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3521 val = This::insert_val_arm_movw_movt(val, x);
3522 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3523 // FIXME: IHI0044D says that we should check for overflow.
3524 return This::STATUS_OKAY;
3525 }
3526
3527 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3528 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3529 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3530 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3531 static inline typename This::Status
3532 thm_movw(unsigned char* view,
3533 const Sized_relobj_file<32, big_endian>* object,
3534 const Symbol_value<32>* psymval,
3535 Arm_address relative_address_base,
3536 Arm_address thumb_bit,
3537 bool check_overflow)
3538 {
3539 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3540 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3541 Valtype* wv = reinterpret_cast<Valtype*>(view);
3542 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3543 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3544 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3545 Reltype x =
3546 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3547 val = This::insert_val_thumb_movw_movt(val, x);
3548 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3549 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3550 return ((check_overflow && Bits<16>::has_overflow32(x))
3551 ? This::STATUS_OVERFLOW
3552 : This::STATUS_OKAY);
3553 }
3554
3555 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3556 // R_ARM_THM_MOVT_PREL: S + A - P
3557 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3558 static inline typename This::Status
3559 thm_movt(unsigned char* view,
3560 const Sized_relobj_file<32, big_endian>* object,
3561 const Symbol_value<32>* psymval,
3562 Arm_address relative_address_base)
3563 {
3564 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3565 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3566 Valtype* wv = reinterpret_cast<Valtype*>(view);
3567 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3568 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3569 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3570 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3571 val = This::insert_val_thumb_movw_movt(val, x);
3572 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3573 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3574 return This::STATUS_OKAY;
3575 }
3576
3577 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3578 static inline typename This::Status
3579 thm_alu11(unsigned char* view,
3580 const Sized_relobj_file<32, big_endian>* object,
3581 const Symbol_value<32>* psymval,
3582 Arm_address address,
3583 Arm_address thumb_bit)
3584 {
3585 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3586 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3587 Valtype* wv = reinterpret_cast<Valtype*>(view);
3588 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3589 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3590
3591 // f e d c b|a|9|8 7 6 5|4|3 2 1 0||f|e d c|b a 9 8|7 6 5 4 3 2 1 0
3592 // -----------------------------------------------------------------------
3593 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3594 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3595 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3596 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3597 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3598 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3599
3600 // Determine a sign for the addend.
3601 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3602 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3603 // Thumb2 addend encoding:
3604 // imm12 := i | imm3 | imm8
3605 int32_t addend = (insn & 0xff)
3606 | ((insn & 0x00007000) >> 4)
3607 | ((insn & 0x04000000) >> 15);
3608 // Apply a sign to the added.
3609 addend *= sign;
3610
3611 int32_t x = (psymval->value(object, addend) | thumb_bit)
3612 - (address & 0xfffffffc);
3613 Reltype val = abs(x);
3614 // Mask out the value and a distinct part of the ADD/SUB opcode
3615 // (bits 7:5 of opword).
3616 insn = (insn & 0xfb0f8f00)
3617 | (val & 0xff)
3618 | ((val & 0x700) << 4)
3619 | ((val & 0x800) << 15);
3620 // Set the opcode according to whether the value to go in the
3621 // place is negative.
3622 if (x < 0)
3623 insn |= 0x00a00000;
3624
3625 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3626 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3627 return ((val > 0xfff) ?
3628 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3629 }
3630
3631 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3632 static inline typename This::Status
3633 thm_pc8(unsigned char* view,
3634 const Sized_relobj_file<32, big_endian>* object,
3635 const Symbol_value<32>* psymval,
3636 Arm_address address)
3637 {
3638 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3639 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3640 Valtype* wv = reinterpret_cast<Valtype*>(view);
3641 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3642 Reltype addend = ((insn & 0x00ff) << 2);
3643 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3644 Reltype val = abs(x);
3645 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3646
3647 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3648 return ((val > 0x03fc)
3649 ? This::STATUS_OVERFLOW
3650 : This::STATUS_OKAY);
3651 }
3652
3653 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3654 static inline typename This::Status
3655 thm_pc12(unsigned char* view,
3656 const Sized_relobj_file<32, big_endian>* object,
3657 const Symbol_value<32>* psymval,
3658 Arm_address address)
3659 {
3660 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3661 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3662 Valtype* wv = reinterpret_cast<Valtype*>(view);
3663 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3664 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3665 // Determine a sign for the addend (positive if the U bit is 1).
3666 const int sign = (insn & 0x00800000) ? 1 : -1;
3667 int32_t addend = (insn & 0xfff);
3668 // Apply a sign to the added.
3669 addend *= sign;
3670
3671 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3672 Reltype val = abs(x);
3673 // Mask out and apply the value and the U bit.
3674 insn = (insn & 0xff7ff000) | (val & 0xfff);
3675 // Set the U bit according to whether the value to go in the
3676 // place is positive.
3677 if (x >= 0)
3678 insn |= 0x00800000;
3679
3680 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3681 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3682 return ((val > 0xfff) ?
3683 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3684 }
3685
3686 // R_ARM_V4BX
3687 static inline typename This::Status
3688 v4bx(const Relocate_info<32, big_endian>* relinfo,
3689 unsigned char* view,
3690 const Arm_relobj<big_endian>* object,
3691 const Arm_address address,
3692 const bool is_interworking)
3693 {
3694
3695 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3696 Valtype* wv = reinterpret_cast<Valtype*>(view);
3697 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3698
3699 // Ensure that we have a BX instruction.
3700 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3701 const uint32_t reg = (val & 0xf);
3702 if (is_interworking && reg != 0xf)
3703 {
3704 Stub_table<big_endian>* stub_table =
3705 object->stub_table(relinfo->data_shndx);
3706 gold_assert(stub_table != NULL);
3707
3708 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3709 gold_assert(stub != NULL);
3710
3711 int32_t veneer_address =
3712 stub_table->address() + stub->offset() - 8 - address;
3713 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3714 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3715 // Replace with a branch to veneer (B <addr>)
3716 val = (val & 0xf0000000) | 0x0a000000
3717 | ((veneer_address >> 2) & 0x00ffffff);
3718 }
3719 else
3720 {
3721 // Preserve Rm (lowest four bits) and the condition code
3722 // (highest four bits). Other bits encode MOV PC,Rm.
3723 val = (val & 0xf000000f) | 0x01a0f000;
3724 }
3725 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3726 return This::STATUS_OKAY;
3727 }
3728
3729 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3730 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3731 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3732 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3733 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3734 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3735 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3736 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3737 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3738 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3739 static inline typename This::Status
3740 arm_grp_alu(unsigned char* view,
3741 const Sized_relobj_file<32, big_endian>* object,
3742 const Symbol_value<32>* psymval,
3743 const int group,
3744 Arm_address address,
3745 Arm_address thumb_bit,
3746 bool check_overflow)
3747 {
3748 gold_assert(group >= 0 && group < 3);
3749 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3750 Valtype* wv = reinterpret_cast<Valtype*>(view);
3751 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3752
3753 // ALU group relocations are allowed only for the ADD/SUB instructions.
3754 // (0x00800000 - ADD, 0x00400000 - SUB)
3755 const Valtype opcode = insn & 0x01e00000;
3756 if (opcode != 0x00800000 && opcode != 0x00400000)
3757 return This::STATUS_BAD_RELOC;
3758
3759 // Determine a sign for the addend.
3760 const int sign = (opcode == 0x00800000) ? 1 : -1;
3761 // shifter = rotate_imm * 2
3762 const uint32_t shifter = (insn & 0xf00) >> 7;
3763 // Initial addend value.
3764 int32_t addend = insn & 0xff;
3765 // Rotate addend right by shifter.
3766 addend = (addend >> shifter) | (addend << (32 - shifter));
3767 // Apply a sign to the added.
3768 addend *= sign;
3769
3770 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3771 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3772 // Check for overflow if required
3773 if (check_overflow
3774 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3775 return This::STATUS_OVERFLOW;
3776
3777 // Mask out the value and the ADD/SUB part of the opcode; take care
3778 // not to destroy the S bit.
3779 insn &= 0xff1ff000;
3780 // Set the opcode according to whether the value to go in the
3781 // place is negative.
3782 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3783 // Encode the offset (encoded Gn).
3784 insn |= gn;
3785
3786 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3787 return This::STATUS_OKAY;
3788 }
3789
3790 // R_ARM_LDR_PC_G0: S + A - P
3791 // R_ARM_LDR_PC_G1: S + A - P
3792 // R_ARM_LDR_PC_G2: S + A - P
3793 // R_ARM_LDR_SB_G0: S + A - B(S)
3794 // R_ARM_LDR_SB_G1: S + A - B(S)
3795 // R_ARM_LDR_SB_G2: S + A - B(S)
3796 static inline typename This::Status
3797 arm_grp_ldr(unsigned char* view,
3798 const Sized_relobj_file<32, big_endian>* object,
3799 const Symbol_value<32>* psymval,
3800 const int group,
3801 Arm_address address)
3802 {
3803 gold_assert(group >= 0 && group < 3);
3804 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3805 Valtype* wv = reinterpret_cast<Valtype*>(view);
3806 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3807
3808 const int sign = (insn & 0x00800000) ? 1 : -1;
3809 int32_t addend = (insn & 0xfff) * sign;
3810 int32_t x = (psymval->value(object, addend) - address);
3811 // Calculate the relevant G(n-1) value to obtain this stage residual.
3812 Valtype residual =
3813 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3814 if (residual >= 0x1000)
3815 return This::STATUS_OVERFLOW;
3816
3817 // Mask out the value and U bit.
3818 insn &= 0xff7ff000;
3819 // Set the U bit for non-negative values.
3820 if (x >= 0)
3821 insn |= 0x00800000;
3822 insn |= residual;
3823
3824 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3825 return This::STATUS_OKAY;
3826 }
3827
3828 // R_ARM_LDRS_PC_G0: S + A - P
3829 // R_ARM_LDRS_PC_G1: S + A - P
3830 // R_ARM_LDRS_PC_G2: S + A - P
3831 // R_ARM_LDRS_SB_G0: S + A - B(S)
3832 // R_ARM_LDRS_SB_G1: S + A - B(S)
3833 // R_ARM_LDRS_SB_G2: S + A - B(S)
3834 static inline typename This::Status
3835 arm_grp_ldrs(unsigned char* view,
3836 const Sized_relobj_file<32, big_endian>* object,
3837 const Symbol_value<32>* psymval,
3838 const int group,
3839 Arm_address address)
3840 {
3841 gold_assert(group >= 0 && group < 3);
3842 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3843 Valtype* wv = reinterpret_cast<Valtype*>(view);
3844 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3845
3846 const int sign = (insn & 0x00800000) ? 1 : -1;
3847 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3848 int32_t x = (psymval->value(object, addend) - address);
3849 // Calculate the relevant G(n-1) value to obtain this stage residual.
3850 Valtype residual =
3851 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3852 if (residual >= 0x100)
3853 return This::STATUS_OVERFLOW;
3854
3855 // Mask out the value and U bit.
3856 insn &= 0xff7ff0f0;
3857 // Set the U bit for non-negative values.
3858 if (x >= 0)
3859 insn |= 0x00800000;
3860 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3861
3862 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3863 return This::STATUS_OKAY;
3864 }
3865
3866 // R_ARM_LDC_PC_G0: S + A - P
3867 // R_ARM_LDC_PC_G1: S + A - P
3868 // R_ARM_LDC_PC_G2: S + A - P
3869 // R_ARM_LDC_SB_G0: S + A - B(S)
3870 // R_ARM_LDC_SB_G1: S + A - B(S)
3871 // R_ARM_LDC_SB_G2: S + A - B(S)
3872 static inline typename This::Status
3873 arm_grp_ldc(unsigned char* view,
3874 const Sized_relobj_file<32, big_endian>* object,
3875 const Symbol_value<32>* psymval,
3876 const int group,
3877 Arm_address address)
3878 {
3879 gold_assert(group >= 0 && group < 3);
3880 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3881 Valtype* wv = reinterpret_cast<Valtype*>(view);
3882 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3883
3884 const int sign = (insn & 0x00800000) ? 1 : -1;
3885 int32_t addend = ((insn & 0xff) << 2) * sign;
3886 int32_t x = (psymval->value(object, addend) - address);
3887 // Calculate the relevant G(n-1) value to obtain this stage residual.
3888 Valtype residual =
3889 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3890 if ((residual & 0x3) != 0 || residual >= 0x400)
3891 return This::STATUS_OVERFLOW;
3892
3893 // Mask out the value and U bit.
3894 insn &= 0xff7fff00;
3895 // Set the U bit for non-negative values.
3896 if (x >= 0)
3897 insn |= 0x00800000;
3898 insn |= (residual >> 2);
3899
3900 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3901 return This::STATUS_OKAY;
3902 }
3903 };
3904
3905 // Relocate ARM long branches. This handles relocation types
3906 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3907 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3908 // undefined and we do not use PLT in this relocation. In such a case,
3909 // the branch is converted into an NOP.
3910
3911 template<bool big_endian>
3912 typename Arm_relocate_functions<big_endian>::Status
3913 Arm_relocate_functions<big_endian>::arm_branch_common(
3914 unsigned int r_type,
3915 const Relocate_info<32, big_endian>* relinfo,
3916 unsigned char* view,
3917 const Sized_symbol<32>* gsym,
3918 const Arm_relobj<big_endian>* object,
3919 unsigned int r_sym,
3920 const Symbol_value<32>* psymval,
3921 Arm_address address,
3922 Arm_address thumb_bit,
3923 bool is_weakly_undefined_without_plt)
3924 {
3925 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3926 Valtype* wv = reinterpret_cast<Valtype*>(view);
3927 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3928
3929 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3930 && ((val & 0x0f000000UL) == 0x0a000000UL);
3931 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3932 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3933 && ((val & 0x0f000000UL) == 0x0b000000UL);
3934 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3935 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3936
3937 // Check that the instruction is valid.
3938 if (r_type == elfcpp::R_ARM_CALL)
3939 {
3940 if (!insn_is_uncond_bl && !insn_is_blx)
3941 return This::STATUS_BAD_RELOC;
3942 }
3943 else if (r_type == elfcpp::R_ARM_JUMP24)
3944 {
3945 if (!insn_is_b && !insn_is_cond_bl)
3946 return This::STATUS_BAD_RELOC;
3947 }
3948 else if (r_type == elfcpp::R_ARM_PLT32)
3949 {
3950 if (!insn_is_any_branch)
3951 return This::STATUS_BAD_RELOC;
3952 }
3953 else if (r_type == elfcpp::R_ARM_XPC25)
3954 {
3955 // FIXME: AAELF document IH0044C does not say much about it other
3956 // than it being obsolete.
3957 if (!insn_is_any_branch)
3958 return This::STATUS_BAD_RELOC;
3959 }
3960 else
3961 gold_unreachable();
3962
3963 // A branch to an undefined weak symbol is turned into a jump to
3964 // the next instruction unless a PLT entry will be created.
3965 // Do the same for local undefined symbols.
3966 // The jump to the next instruction is optimized as a NOP depending
3967 // on the architecture.
3968 const Target_arm<big_endian>* arm_target =
3969 Target_arm<big_endian>::default_target();
3970 if (is_weakly_undefined_without_plt)
3971 {
3972 gold_assert(!parameters->options().relocatable());
3973 Valtype cond = val & 0xf0000000U;
3974 if (arm_target->may_use_arm_nop())
3975 val = cond | 0x0320f000;
3976 else
3977 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3978 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3979 return This::STATUS_OKAY;
3980 }
3981
3982 Valtype addend = Bits<26>::sign_extend32(val << 2);
3983 Valtype branch_target = psymval->value(object, addend);
3984 int32_t branch_offset = branch_target - address;
3985
3986 // We need a stub if the branch offset is too large or if we need
3987 // to switch mode.
3988 bool may_use_blx = arm_target->may_use_v5t_interworking();
3989 Reloc_stub* stub = NULL;
3990
3991 if (!parameters->options().relocatable()
3992 && (Bits<26>::has_overflow32(branch_offset)
3993 || ((thumb_bit != 0)
3994 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3995 {
3996 Valtype unadjusted_branch_target = psymval->value(object, 0);
3997
3998 Stub_type stub_type =
3999 Reloc_stub::stub_type_for_reloc(r_type, address,
4000 unadjusted_branch_target,
4001 (thumb_bit != 0));
4002 if (stub_type != arm_stub_none)
4003 {
4004 Stub_table<big_endian>* stub_table =
4005 object->stub_table(relinfo->data_shndx);
4006 gold_assert(stub_table != NULL);
4007
4008 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4009 stub = stub_table->find_reloc_stub(stub_key);
4010 gold_assert(stub != NULL);
4011 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4012 branch_target = stub_table->address() + stub->offset() + addend;
4013 branch_offset = branch_target - address;
4014 gold_assert(!Bits<26>::has_overflow32(branch_offset));
4015 }
4016 }
4017
4018 // At this point, if we still need to switch mode, the instruction
4019 // must either be a BLX or a BL that can be converted to a BLX.
4020 if (thumb_bit != 0)
4021 {
4022 // Turn BL to BLX.
4023 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
4024 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
4025 }
4026
4027 val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
4028 elfcpp::Swap<32, big_endian>::writeval(wv, val);
4029 return (Bits<26>::has_overflow32(branch_offset)
4030 ? This::STATUS_OVERFLOW
4031 : This::STATUS_OKAY);
4032 }
4033
4034 // Relocate THUMB long branches. This handles relocation types
4035 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
4036 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4037 // undefined and we do not use PLT in this relocation. In such a case,
4038 // the branch is converted into an NOP.
4039
4040 template<bool big_endian>
4041 typename Arm_relocate_functions<big_endian>::Status
4042 Arm_relocate_functions<big_endian>::thumb_branch_common(
4043 unsigned int r_type,
4044 const Relocate_info<32, big_endian>* relinfo,
4045 unsigned char* view,
4046 const Sized_symbol<32>* gsym,
4047 const Arm_relobj<big_endian>* object,
4048 unsigned int r_sym,
4049 const Symbol_value<32>* psymval,
4050 Arm_address address,
4051 Arm_address thumb_bit,
4052 bool is_weakly_undefined_without_plt)
4053 {
4054 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4055 Valtype* wv = reinterpret_cast<Valtype*>(view);
4056 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4057 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4058
4059 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4060 // into account.
4061 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4062 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4063
4064 // Check that the instruction is valid.
4065 if (r_type == elfcpp::R_ARM_THM_CALL)
4066 {
4067 if (!is_bl_insn && !is_blx_insn)
4068 return This::STATUS_BAD_RELOC;
4069 }
4070 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4071 {
4072 // This cannot be a BLX.
4073 if (!is_bl_insn)
4074 return This::STATUS_BAD_RELOC;
4075 }
4076 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4077 {
4078 // Check for Thumb to Thumb call.
4079 if (!is_blx_insn)
4080 return This::STATUS_BAD_RELOC;
4081 if (thumb_bit != 0)
4082 {
4083 gold_warning(_("%s: Thumb BLX instruction targets "
4084 "thumb function '%s'."),
4085 object->name().c_str(),
4086 (gsym ? gsym->name() : "(local)"));
4087 // Convert BLX to BL.
4088 lower_insn |= 0x1000U;
4089 }
4090 }
4091 else
4092 gold_unreachable();
4093
4094 // A branch to an undefined weak symbol is turned into a jump to
4095 // the next instruction unless a PLT entry will be created.
4096 // The jump to the next instruction is optimized as a NOP.W for
4097 // Thumb-2 enabled architectures.
4098 const Target_arm<big_endian>* arm_target =
4099 Target_arm<big_endian>::default_target();
4100 if (is_weakly_undefined_without_plt)
4101 {
4102 gold_assert(!parameters->options().relocatable());
4103 if (arm_target->may_use_thumb2_nop())
4104 {
4105 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4106 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4107 }
4108 else
4109 {
4110 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4111 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4112 }
4113 return This::STATUS_OKAY;
4114 }
4115
4116 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4117 Arm_address branch_target = psymval->value(object, addend);
4118
4119 // For BLX, bit 1 of target address comes from bit 1 of base address.
4120 bool may_use_blx = arm_target->may_use_v5t_interworking();
4121 if (thumb_bit == 0 && may_use_blx)
4122 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4123
4124 int32_t branch_offset = branch_target - address;
4125
4126 // We need a stub if the branch offset is too large or if we need
4127 // to switch mode.
4128 bool thumb2 = arm_target->using_thumb2();
4129 if (!parameters->options().relocatable()
4130 && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4131 || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4132 || ((thumb_bit == 0)
4133 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4134 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4135 {
4136 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4137
4138 Stub_type stub_type =
4139 Reloc_stub::stub_type_for_reloc(r_type, address,
4140 unadjusted_branch_target,
4141 (thumb_bit != 0));
4142
4143 if (stub_type != arm_stub_none)
4144 {
4145 Stub_table<big_endian>* stub_table =
4146 object->stub_table(relinfo->data_shndx);
4147 gold_assert(stub_table != NULL);
4148
4149 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4150 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4151 gold_assert(stub != NULL);
4152 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4153 branch_target = stub_table->address() + stub->offset() + addend;
4154 if (thumb_bit == 0 && may_use_blx)
4155 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4156 branch_offset = branch_target - address;
4157 }
4158 }
4159
4160 // At this point, if we still need to switch mode, the instruction
4161 // must either be a BLX or a BL that can be converted to a BLX.
4162 if (thumb_bit == 0)
4163 {
4164 gold_assert(may_use_blx
4165 && (r_type == elfcpp::R_ARM_THM_CALL
4166 || r_type == elfcpp::R_ARM_THM_XPC22));
4167 // Make sure this is a BLX.
4168 lower_insn &= ~0x1000U;
4169 }
4170 else
4171 {
4172 // Make sure this is a BL.
4173 lower_insn |= 0x1000U;
4174 }
4175
4176 // For a BLX instruction, make sure that the relocation is rounded up
4177 // to a word boundary. This follows the semantics of the instruction
4178 // which specifies that bit 1 of the target address will come from bit
4179 // 1 of the base address.
4180 if ((lower_insn & 0x5000U) == 0x4000U)
4181 gold_assert((branch_offset & 3) == 0);
4182
4183 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4184 // We use the Thumb-2 encoding, which is safe even if dealing with
4185 // a Thumb-1 instruction by virtue of our overflow check above. */
4186 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4187 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4188
4189 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4190 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4191
4192 gold_assert(!Bits<25>::has_overflow32(branch_offset));
4193
4194 return ((thumb2
4195 ? Bits<25>::has_overflow32(branch_offset)
4196 : Bits<23>::has_overflow32(branch_offset))
4197 ? This::STATUS_OVERFLOW
4198 : This::STATUS_OKAY);
4199 }
4200
4201 // Relocate THUMB-2 long conditional branches.
4202 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4203 // undefined and we do not use PLT in this relocation. In such a case,
4204 // the branch is converted into an NOP.
4205
4206 template<bool big_endian>
4207 typename Arm_relocate_functions<big_endian>::Status
4208 Arm_relocate_functions<big_endian>::thm_jump19(
4209 unsigned char* view,
4210 const Arm_relobj<big_endian>* object,
4211 const Symbol_value<32>* psymval,
4212 Arm_address address,
4213 Arm_address thumb_bit)
4214 {
4215 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4216 Valtype* wv = reinterpret_cast<Valtype*>(view);
4217 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4218 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4219 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4220
4221 Arm_address branch_target = psymval->value(object, addend);
4222 int32_t branch_offset = branch_target - address;
4223
4224 // ??? Should handle interworking? GCC might someday try to
4225 // use this for tail calls.
4226 // FIXME: We do support thumb entry to PLT yet.
4227 if (thumb_bit == 0)
4228 {
4229 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4230 return This::STATUS_BAD_RELOC;
4231 }
4232
4233 // Put RELOCATION back into the insn.
4234 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4235 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4236
4237 // Put the relocated value back in the object file:
4238 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4239 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4240
4241 return (Bits<21>::has_overflow32(branch_offset)
4242 ? This::STATUS_OVERFLOW
4243 : This::STATUS_OKAY);
4244 }
4245
4246 // Get the GOT section, creating it if necessary.
4247
4248 template<bool big_endian>
4249 Arm_output_data_got<big_endian>*
4250 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4251 {
4252 if (this->got_ == NULL)
4253 {
4254 gold_assert(symtab != NULL && layout != NULL);
4255
4256 // When using -z now, we can treat .got as a relro section.
4257 // Without -z now, it is modified after program startup by lazy
4258 // PLT relocations.
4259 bool is_got_relro = parameters->options().now();
4260 Output_section_order got_order = (is_got_relro
4261 ? ORDER_RELRO_LAST
4262 : ORDER_DATA);
4263
4264 // Unlike some targets (.e.g x86), ARM does not use separate .got and
4265 // .got.plt sections in output. The output .got section contains both
4266 // PLT and non-PLT GOT entries.
4267 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4268
4269 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4270 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4271 this->got_, got_order, is_got_relro);
4272
4273 // The old GNU linker creates a .got.plt section. We just
4274 // create another set of data in the .got section. Note that we
4275 // always create a PLT if we create a GOT, although the PLT
4276 // might be empty.
4277 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4278 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4279 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4280 this->got_plt_, got_order, is_got_relro);
4281
4282 // The first three entries are reserved.
4283 this->got_plt_->set_current_data_size(3 * 4);
4284
4285 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4286 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4287 Symbol_table::PREDEFINED,
4288 this->got_plt_,
4289 0, 0, elfcpp::STT_OBJECT,
4290 elfcpp::STB_LOCAL,
4291 elfcpp::STV_HIDDEN, 0,
4292 false, false);
4293
4294 // If there are any IRELATIVE relocations, they get GOT entries
4295 // in .got.plt after the jump slot entries.
4296 this->got_irelative_ = new Output_data_space(4, "** GOT IRELATIVE PLT");
4297 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4298 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4299 this->got_irelative_,
4300 got_order, is_got_relro);
4301
4302 }
4303 return this->got_;
4304 }
4305
4306 // Get the dynamic reloc section, creating it if necessary.
4307
4308 template<bool big_endian>
4309 typename Target_arm<big_endian>::Reloc_section*
4310 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4311 {
4312 if (this->rel_dyn_ == NULL)
4313 {
4314 gold_assert(layout != NULL);
4315 // Create both relocation sections in the same place, so as to ensure
4316 // their relative order in the output section.
4317 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4318 this->rel_irelative_ = new Reloc_section(false);
4319 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4320 elfcpp::SHF_ALLOC, this->rel_dyn_,
4321 ORDER_DYNAMIC_RELOCS, false);
4322 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4323 elfcpp::SHF_ALLOC, this->rel_irelative_,
4324 ORDER_DYNAMIC_RELOCS, false);
4325 }
4326 return this->rel_dyn_;
4327 }
4328
4329
4330 // Get the section to use for IRELATIVE relocs, creating it if necessary. These
4331 // go in .rela.dyn, but only after all other dynamic relocations. They need to
4332 // follow the other dynamic relocations so that they can refer to global
4333 // variables initialized by those relocs.
4334
4335 template<bool big_endian>
4336 typename Target_arm<big_endian>::Reloc_section*
4337 Target_arm<big_endian>::rel_irelative_section(Layout* layout)
4338 {
4339 if (this->rel_irelative_ == NULL)
4340 {
4341 // Delegate the creation to rel_dyn_section so as to ensure their order in
4342 // the output section.
4343 this->rel_dyn_section(layout);
4344 gold_assert(this->rel_irelative_ != NULL
4345 && (this->rel_dyn_->output_section()
4346 == this->rel_irelative_->output_section()));
4347 }
4348 return this->rel_irelative_;
4349 }
4350
4351
4352 // Insn_template methods.
4353
4354 // Return byte size of an instruction template.
4355
4356 size_t
4357 Insn_template::size() const
4358 {
4359 switch (this->type())
4360 {
4361 case THUMB16_TYPE:
4362 case THUMB16_SPECIAL_TYPE:
4363 return 2;
4364 case ARM_TYPE:
4365 case THUMB32_TYPE:
4366 case DATA_TYPE:
4367 return 4;
4368 default:
4369 gold_unreachable();
4370 }
4371 }
4372
4373 // Return alignment of an instruction template.
4374
4375 unsigned
4376 Insn_template::alignment() const
4377 {
4378 switch (this->type())
4379 {
4380 case THUMB16_TYPE:
4381 case THUMB16_SPECIAL_TYPE:
4382 case THUMB32_TYPE:
4383 return 2;
4384 case ARM_TYPE:
4385 case DATA_TYPE:
4386 return 4;
4387 default:
4388 gold_unreachable();
4389 }
4390 }
4391
4392 // Stub_template methods.
4393
4394 Stub_template::Stub_template(
4395 Stub_type type, const Insn_template* insns,
4396 size_t insn_count)
4397 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4398 entry_in_thumb_mode_(false), relocs_()
4399 {
4400 off_t offset = 0;
4401
4402 // Compute byte size and alignment of stub template.
4403 for (size_t i = 0; i < insn_count; i++)
4404 {
4405 unsigned insn_alignment = insns[i].alignment();
4406 size_t insn_size = insns[i].size();
4407 gold_assert((offset & (insn_alignment - 1)) == 0);
4408 this->alignment_ = std::max(this->alignment_, insn_alignment);
4409 switch (insns[i].type())
4410 {
4411 case Insn_template::THUMB16_TYPE:
4412 case Insn_template::THUMB16_SPECIAL_TYPE:
4413 if (i == 0)
4414 this->entry_in_thumb_mode_ = true;
4415 break;
4416
4417 case Insn_template::THUMB32_TYPE:
4418 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4419 this->relocs_.push_back(Reloc(i, offset));
4420 if (i == 0)
4421 this->entry_in_thumb_mode_ = true;
4422 break;
4423
4424 case Insn_template::ARM_TYPE:
4425 // Handle cases where the target is encoded within the
4426 // instruction.
4427 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4428 this->relocs_.push_back(Reloc(i, offset));
4429 break;
4430
4431 case Insn_template::DATA_TYPE:
4432 // Entry point cannot be data.
4433 gold_assert(i != 0);
4434 this->relocs_.push_back(Reloc(i, offset));
4435 break;
4436
4437 default:
4438 gold_unreachable();
4439 }
4440 offset += insn_size;
4441 }
4442 this->size_ = offset;
4443 }
4444
4445 // Stub methods.
4446
4447 // Template to implement do_write for a specific target endianness.
4448
4449 template<bool big_endian>
4450 void inline
4451 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4452 {
4453 const Stub_template* stub_template = this->stub_template();
4454 const Insn_template* insns = stub_template->insns();
4455
4456 // FIXME: We do not handle BE8 encoding yet.
4457 unsigned char* pov = view;
4458 for (size_t i = 0; i < stub_template->insn_count(); i++)
4459 {
4460 switch (insns[i].type())
4461 {
4462 case Insn_template::THUMB16_TYPE:
4463 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4464 break;
4465 case Insn_template::THUMB16_SPECIAL_TYPE:
4466 elfcpp::Swap<16, big_endian>::writeval(
4467 pov,
4468 this->thumb16_special(i));
4469 break;
4470 case Insn_template::THUMB32_TYPE:
4471 {
4472 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4473 uint32_t lo = insns[i].data() & 0xffff;
4474 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4475 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4476 }
4477 break;
4478 case Insn_template::ARM_TYPE:
4479 case Insn_template::DATA_TYPE:
4480 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4481 break;
4482 default:
4483 gold_unreachable();
4484 }
4485 pov += insns[i].size();
4486 }
4487 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4488 }
4489
4490 // Reloc_stub::Key methods.
4491
4492 // Dump a Key as a string for debugging.
4493
4494 std::string
4495 Reloc_stub::Key::name() const
4496 {
4497 if (this->r_sym_ == invalid_index)
4498 {
4499 // Global symbol key name
4500 // <stub-type>:<symbol name>:<addend>.
4501 const std::string sym_name = this->u_.symbol->name();
4502 // We need to print two hex number and two colons. So just add 100 bytes
4503 // to the symbol name size.
4504 size_t len = sym_name.size() + 100;
4505 char* buffer = new char[len];
4506 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4507 sym_name.c_str(), this->addend_);
4508 gold_assert(c > 0 && c < static_cast<int>(len));
4509 delete[] buffer;
4510 return std::string(buffer);
4511 }
4512 else
4513 {
4514 // local symbol key name
4515 // <stub-type>:<object>:<r_sym>:<addend>.
4516 const size_t len = 200;
4517 char buffer[len];
4518 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4519 this->u_.relobj, this->r_sym_, this->addend_);
4520 gold_assert(c > 0 && c < static_cast<int>(len));
4521 return std::string(buffer);
4522 }
4523 }
4524
4525 // Reloc_stub methods.
4526
4527 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4528 // LOCATION to DESTINATION.
4529 // This code is based on the arm_type_of_stub function in
4530 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4531 // class simple.
4532
4533 Stub_type
4534 Reloc_stub::stub_type_for_reloc(
4535 unsigned int r_type,
4536 Arm_address location,
4537 Arm_address destination,
4538 bool target_is_thumb)
4539 {
4540 Stub_type stub_type = arm_stub_none;
4541
4542 // This is a bit ugly but we want to avoid using a templated class for
4543 // big and little endianities.
4544 bool may_use_blx;
4545 bool should_force_pic_veneer;
4546 bool thumb2;
4547 bool thumb_only;
4548 if (parameters->target().is_big_endian())
4549 {
4550 const Target_arm<true>* big_endian_target =
4551 Target_arm<true>::default_target();
4552 may_use_blx = big_endian_target->may_use_v5t_interworking();
4553 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4554 thumb2 = big_endian_target->using_thumb2();
4555 thumb_only = big_endian_target->using_thumb_only();
4556 }
4557 else
4558 {
4559 const Target_arm<false>* little_endian_target =
4560 Target_arm<false>::default_target();
4561 may_use_blx = little_endian_target->may_use_v5t_interworking();
4562 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4563 thumb2 = little_endian_target->using_thumb2();
4564 thumb_only = little_endian_target->using_thumb_only();
4565 }
4566
4567 int64_t branch_offset;
4568 bool output_is_position_independent =
4569 parameters->options().output_is_position_independent();
4570 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4571 {
4572 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4573 // base address (instruction address + 4).
4574 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4575 destination = Bits<32>::bit_select32(destination, location, 0x2);
4576 branch_offset = static_cast<int64_t>(destination) - location;
4577
4578 // Handle cases where:
4579 // - this call goes too far (different Thumb/Thumb2 max
4580 // distance)
4581 // - it's a Thumb->Arm call and blx is not available, or it's a
4582 // Thumb->Arm branch (not bl). A stub is needed in this case.
4583 if ((!thumb2
4584 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4585 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4586 || (thumb2
4587 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4588 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4589 || ((!target_is_thumb)
4590 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4591 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4592 {
4593 if (target_is_thumb)
4594 {
4595 // Thumb to thumb.
4596 if (!thumb_only)
4597 {
4598 stub_type = (output_is_position_independent
4599 || should_force_pic_veneer)
4600 // PIC stubs.
4601 ? ((may_use_blx
4602 && (r_type == elfcpp::R_ARM_THM_CALL))
4603 // V5T and above. Stub starts with ARM code, so
4604 // we must be able to switch mode before
4605 // reaching it, which is only possible for 'bl'
4606 // (ie R_ARM_THM_CALL relocation).
4607 ? arm_stub_long_branch_any_thumb_pic
4608 // On V4T, use Thumb code only.
4609 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4610
4611 // non-PIC stubs.
4612 : ((may_use_blx
4613 && (r_type == elfcpp::R_ARM_THM_CALL))
4614 ? arm_stub_long_branch_any_any // V5T and above.
4615 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4616 }
4617 else
4618 {
4619 stub_type = (output_is_position_independent
4620 || should_force_pic_veneer)
4621 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4622 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4623 }
4624 }
4625 else
4626 {
4627 // Thumb to arm.
4628
4629 // FIXME: We should check that the input section is from an
4630 // object that has interwork enabled.
4631
4632 stub_type = (output_is_position_independent
4633 || should_force_pic_veneer)
4634 // PIC stubs.
4635 ? ((may_use_blx
4636 && (r_type == elfcpp::R_ARM_THM_CALL))
4637 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4638 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4639
4640 // non-PIC stubs.
4641 : ((may_use_blx
4642 && (r_type == elfcpp::R_ARM_THM_CALL))
4643 ? arm_stub_long_branch_any_any // V5T and above.
4644 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4645
4646 // Handle v4t short branches.
4647 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4648 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4649 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4650 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4651 }
4652 }
4653 }
4654 else if (r_type == elfcpp::R_ARM_CALL
4655 || r_type == elfcpp::R_ARM_JUMP24
4656 || r_type == elfcpp::R_ARM_PLT32)
4657 {
4658 branch_offset = static_cast<int64_t>(destination) - location;
4659 if (target_is_thumb)
4660 {
4661 // Arm to thumb.
4662
4663 // FIXME: We should check that the input section is from an
4664 // object that has interwork enabled.
4665
4666 // We have an extra 2-bytes reach because of
4667 // the mode change (bit 24 (H) of BLX encoding).
4668 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4669 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4670 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4671 || (r_type == elfcpp::R_ARM_JUMP24)
4672 || (r_type == elfcpp::R_ARM_PLT32))
4673 {
4674 stub_type = (output_is_position_independent
4675 || should_force_pic_veneer)
4676 // PIC stubs.
4677 ? (may_use_blx
4678 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4679 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4680
4681 // non-PIC stubs.
4682 : (may_use_blx
4683 ? arm_stub_long_branch_any_any // V5T and above.
4684 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4685 }
4686 }
4687 else
4688 {
4689 // Arm to arm.
4690 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4691 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4692 {
4693 stub_type = (output_is_position_independent
4694 || should_force_pic_veneer)
4695 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4696 : arm_stub_long_branch_any_any; /// non-PIC.
4697 }
4698 }
4699 }
4700
4701 return stub_type;
4702 }
4703
4704 // Cortex_a8_stub methods.
4705
4706 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4707 // I is the position of the instruction template in the stub template.
4708
4709 uint16_t
4710 Cortex_a8_stub::do_thumb16_special(size_t i)
4711 {
4712 // The only use of this is to copy condition code from a conditional
4713 // branch being worked around to the corresponding conditional branch in
4714 // to the stub.
4715 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4716 && i == 0);
4717 uint16_t data = this->stub_template()->insns()[i].data();
4718 gold_assert((data & 0xff00U) == 0xd000U);
4719 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4720 return data;
4721 }
4722
4723 // Stub_factory methods.
4724
4725 Stub_factory::Stub_factory()
4726 {
4727 // The instruction template sequences are declared as static
4728 // objects and initialized first time the constructor runs.
4729
4730 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4731 // to reach the stub if necessary.
4732 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4733 {
4734 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4735 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4736 // dcd R_ARM_ABS32(X)
4737 };
4738
4739 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4740 // available.
4741 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4742 {
4743 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4744 Insn_template::arm_insn(0xe12fff1c), // bx ip
4745 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4746 // dcd R_ARM_ABS32(X)
4747 };
4748
4749 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4750 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4751 {
4752 Insn_template::thumb16_insn(0xb401), // push {r0}
4753 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4754 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4755 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4756 Insn_template::thumb16_insn(0x4760), // bx ip
4757 Insn_template::thumb16_insn(0xbf00), // nop
4758 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4759 // dcd R_ARM_ABS32(X)
4760 };
4761
4762 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4763 // allowed.
4764 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4765 {
4766 Insn_template::thumb16_insn(0x4778), // bx pc
4767 Insn_template::thumb16_insn(0x46c0), // nop
4768 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4769 Insn_template::arm_insn(0xe12fff1c), // bx ip
4770 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4771 // dcd R_ARM_ABS32(X)
4772 };
4773
4774 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4775 // available.
4776 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4777 {
4778 Insn_template::thumb16_insn(0x4778), // bx pc
4779 Insn_template::thumb16_insn(0x46c0), // nop
4780 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4781 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4782 // dcd R_ARM_ABS32(X)
4783 };
4784
4785 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4786 // one, when the destination is close enough.
4787 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4788 {
4789 Insn_template::thumb16_insn(0x4778), // bx pc
4790 Insn_template::thumb16_insn(0x46c0), // nop
4791 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4792 };
4793
4794 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4795 // blx to reach the stub if necessary.
4796 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4797 {
4798 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4799 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4800 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4801 // dcd R_ARM_REL32(X-4)
4802 };
4803
4804 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4805 // blx to reach the stub if necessary. We can not add into pc;
4806 // it is not guaranteed to mode switch (different in ARMv6 and
4807 // ARMv7).
4808 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4809 {
4810 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4811 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4812 Insn_template::arm_insn(0xe12fff1c), // bx ip
4813 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4814 // dcd R_ARM_REL32(X)
4815 };
4816
4817 // V4T ARM -> ARM long branch stub, PIC.
4818 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4819 {
4820 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4821 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4822 Insn_template::arm_insn(0xe12fff1c), // bx ip
4823 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4824 // dcd R_ARM_REL32(X)
4825 };
4826
4827 // V4T Thumb -> ARM long branch stub, PIC.
4828 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4829 {
4830 Insn_template::thumb16_insn(0x4778), // bx pc
4831 Insn_template::thumb16_insn(0x46c0), // nop
4832 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4833 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4834 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4835 // dcd R_ARM_REL32(X)
4836 };
4837
4838 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4839 // architectures.
4840 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4841 {
4842 Insn_template::thumb16_insn(0xb401), // push {r0}
4843 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4844 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4845 Insn_template::thumb16_insn(0x4484), // add ip, r0
4846 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4847 Insn_template::thumb16_insn(0x4760), // bx ip
4848 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4849 // dcd R_ARM_REL32(X)
4850 };
4851
4852 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4853 // allowed.
4854 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4855 {
4856 Insn_template::thumb16_insn(0x4778), // bx pc
4857 Insn_template::thumb16_insn(0x46c0), // nop
4858 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4859 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4860 Insn_template::arm_insn(0xe12fff1c), // bx ip
4861 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4862 // dcd R_ARM_REL32(X)
4863 };
4864
4865 // Cortex-A8 erratum-workaround stubs.
4866
4867 // Stub used for conditional branches (which may be beyond +/-1MB away,
4868 // so we can't use a conditional branch to reach this stub).
4869
4870 // original code:
4871 //
4872 // b<cond> X
4873 // after:
4874 //
4875 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4876 {
4877 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4878 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4879 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4880 // b.w X
4881 };
4882
4883 // Stub used for b.w and bl.w instructions.
4884
4885 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4886 {
4887 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4888 };
4889
4890 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4891 {
4892 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4893 };
4894
4895 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4896 // instruction (which switches to ARM mode) to point to this stub. Jump to
4897 // the real destination using an ARM-mode branch.
4898 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4899 {
4900 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4901 };
4902
4903 // Stub used to provide an interworking for R_ARM_V4BX relocation
4904 // (bx r[n] instruction).
4905 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4906 {
4907 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4908 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4909 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4910 };
4911
4912 // Fill in the stub template look-up table. Stub templates are constructed
4913 // per instance of Stub_factory for fast look-up without locking
4914 // in a thread-enabled environment.
4915
4916 this->stub_templates_[arm_stub_none] =
4917 new Stub_template(arm_stub_none, NULL, 0);
4918
4919 #define DEF_STUB(x) \
4920 do \
4921 { \
4922 size_t array_size \
4923 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4924 Stub_type type = arm_stub_##x; \
4925 this->stub_templates_[type] = \
4926 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4927 } \
4928 while (0);
4929
4930 DEF_STUBS
4931 #undef DEF_STUB
4932 }
4933
4934 // Stub_table methods.
4935
4936 // Remove all Cortex-A8 stub.
4937
4938 template<bool big_endian>
4939 void
4940 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4941 {
4942 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4943 p != this->cortex_a8_stubs_.end();
4944 ++p)
4945 delete p->second;
4946 this->cortex_a8_stubs_.clear();
4947 }
4948
4949 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4950
4951 template<bool big_endian>
4952 void
4953 Stub_table<big_endian>::relocate_stub(
4954 Stub* stub,
4955 const Relocate_info<32, big_endian>* relinfo,
4956 Target_arm<big_endian>* arm_target,
4957 Output_section* output_section,
4958 unsigned char* view,
4959 Arm_address address,
4960 section_size_type view_size)
4961 {
4962 const Stub_template* stub_template = stub->stub_template();
4963 if (stub_template->reloc_count() != 0)
4964 {
4965 // Adjust view to cover the stub only.
4966 section_size_type offset = stub->offset();
4967 section_size_type stub_size = stub_template->size();
4968 gold_assert(offset + stub_size <= view_size);
4969
4970 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4971 address + offset, stub_size);
4972 }
4973 }
4974
4975 // Relocate all stubs in this stub table.
4976
4977 template<bool big_endian>
4978 void
4979 Stub_table<big_endian>::relocate_stubs(
4980 const Relocate_info<32, big_endian>* relinfo,
4981 Target_arm<big_endian>* arm_target,
4982 Output_section* output_section,
4983 unsigned char* view,
4984 Arm_address address,
4985 section_size_type view_size)
4986 {
4987 // If we are passed a view bigger than the stub table's. we need to
4988 // adjust the view.
4989 gold_assert(address == this->address()
4990 && (view_size
4991 == static_cast<section_size_type>(this->data_size())));
4992
4993 // Relocate all relocation stubs.
4994 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4995 p != this->reloc_stubs_.end();
4996 ++p)
4997 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4998 address, view_size);
4999
5000 // Relocate all Cortex-A8 stubs.
5001 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
5002 p != this->cortex_a8_stubs_.end();
5003 ++p)
5004 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
5005 address, view_size);
5006
5007 // Relocate all ARM V4BX stubs.
5008 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
5009 p != this->arm_v4bx_stubs_.end();
5010 ++p)
5011 {
5012 if (*p != NULL)
5013 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
5014 address, view_size);
5015 }
5016 }
5017
5018 // Write out the stubs to file.
5019
5020 template<bool big_endian>
5021 void
5022 Stub_table<big_endian>::do_write(Output_file* of)
5023 {
5024 off_t offset = this->offset();
5025 const section_size_type oview_size =
5026 convert_to_section_size_type(this->data_size());
5027 unsigned char* const oview = of->get_output_view(offset, oview_size);
5028
5029 // Write relocation stubs.
5030 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
5031 p != this->reloc_stubs_.end();
5032 ++p)
5033 {
5034 Reloc_stub* stub = p->second;
5035 Arm_address address = this->address() + stub->offset();
5036 gold_assert(address
5037 == align_address(address,
5038 stub->stub_template()->alignment()));
5039 stub->write(oview + stub->offset(), stub->stub_template()->size(),
5040 big_endian);
5041 }
5042
5043 // Write Cortex-A8 stubs.
5044 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5045 p != this->cortex_a8_stubs_.end();
5046 ++p)
5047 {
5048 Cortex_a8_stub* stub = p->second;
5049 Arm_address address = this->address() + stub->offset();
5050 gold_assert(address
5051 == align_address(address,
5052 stub->stub_template()->alignment()));
5053 stub->write(oview + stub->offset(), stub->stub_template()->size(),
5054 big_endian);
5055 }
5056
5057 // Write ARM V4BX relocation stubs.
5058 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5059 p != this->arm_v4bx_stubs_.end();
5060 ++p)
5061 {
5062 if (*p == NULL)
5063 continue;
5064
5065 Arm_address address = this->address() + (*p)->offset();
5066 gold_assert(address
5067 == align_address(address,
5068 (*p)->stub_template()->alignment()));
5069 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
5070 big_endian);
5071 }
5072
5073 of->write_output_view(this->offset(), oview_size, oview);
5074 }
5075
5076 // Update the data size and address alignment of the stub table at the end
5077 // of a relaxation pass. Return true if either the data size or the
5078 // alignment changed in this relaxation pass.
5079
5080 template<bool big_endian>
5081 bool
5082 Stub_table<big_endian>::update_data_size_and_addralign()
5083 {
5084 // Go over all stubs in table to compute data size and address alignment.
5085 off_t size = this->reloc_stubs_size_;
5086 unsigned addralign = this->reloc_stubs_addralign_;
5087
5088 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5089 p != this->cortex_a8_stubs_.end();
5090 ++p)
5091 {
5092 const Stub_template* stub_template = p->second->stub_template();
5093 addralign = std::max(addralign, stub_template->alignment());
5094 size = (align_address(size, stub_template->alignment())
5095 + stub_template->size());
5096 }
5097
5098 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5099 p != this->arm_v4bx_stubs_.end();
5100 ++p)
5101 {
5102 if (*p == NULL)
5103 continue;
5104
5105 const Stub_template* stub_template = (*p)->stub_template();
5106 addralign = std::max(addralign, stub_template->alignment());
5107 size = (align_address(size, stub_template->alignment())
5108 + stub_template->size());
5109 }
5110
5111 // Check if either data size or alignment changed in this pass.
5112 // Update prev_data_size_ and prev_addralign_. These will be used
5113 // as the current data size and address alignment for the next pass.
5114 bool changed = size != this->prev_data_size_;
5115 this->prev_data_size_ = size;
5116
5117 if (addralign != this->prev_addralign_)
5118 changed = true;
5119 this->prev_addralign_ = addralign;
5120
5121 return changed;
5122 }
5123
5124 // Finalize the stubs. This sets the offsets of the stubs within the stub
5125 // table. It also marks all input sections needing Cortex-A8 workaround.
5126
5127 template<bool big_endian>
5128 void
5129 Stub_table<big_endian>::finalize_stubs()
5130 {
5131 off_t off = this->reloc_stubs_size_;
5132 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5133 p != this->cortex_a8_stubs_.end();
5134 ++p)
5135 {
5136 Cortex_a8_stub* stub = p->second;
5137 const Stub_template* stub_template = stub->stub_template();
5138 uint64_t stub_addralign = stub_template->alignment();
5139 off = align_address(off, stub_addralign);
5140 stub->set_offset(off);
5141 off += stub_template->size();
5142
5143 // Mark input section so that we can determine later if a code section
5144 // needs the Cortex-A8 workaround quickly.
5145 Arm_relobj<big_endian>* arm_relobj =
5146 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5147 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5148 }
5149
5150 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5151 p != this->arm_v4bx_stubs_.end();
5152 ++p)
5153 {
5154 if (*p == NULL)
5155 continue;
5156
5157 const Stub_template* stub_template = (*p)->stub_template();
5158 uint64_t stub_addralign = stub_template->alignment();
5159 off = align_address(off, stub_addralign);
5160 (*p)->set_offset(off);
5161 off += stub_template->size();
5162 }
5163
5164 gold_assert(off <= this->prev_data_size_);
5165 }
5166
5167 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5168 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5169 // of the address range seen by the linker.
5170
5171 template<bool big_endian>
5172 void
5173 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5174 Target_arm<big_endian>* arm_target,
5175 unsigned char* view,
5176 Arm_address view_address,
5177 section_size_type view_size)
5178 {
5179 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5180 for (Cortex_a8_stub_list::const_iterator p =
5181 this->cortex_a8_stubs_.lower_bound(view_address);
5182 ((p != this->cortex_a8_stubs_.end())
5183 && (p->first < (view_address + view_size)));
5184 ++p)
5185 {
5186 // We do not store the THUMB bit in the LSB of either the branch address
5187 // or the stub offset. There is no need to strip the LSB.
5188 Arm_address branch_address = p->first;
5189 const Cortex_a8_stub* stub = p->second;
5190 Arm_address stub_address = this->address() + stub->offset();
5191
5192 // Offset of the branch instruction relative to this view.
5193 section_size_type offset =
5194 convert_to_section_size_type(branch_address - view_address);
5195 gold_assert((offset + 4) <= view_size);
5196
5197 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5198 view + offset, branch_address);
5199 }
5200 }
5201
5202 // Arm_input_section methods.
5203
5204 // Initialize an Arm_input_section.
5205
5206 template<bool big_endian>
5207 void
5208 Arm_input_section<big_endian>::init()
5209 {
5210 Relobj* relobj = this->relobj();
5211 unsigned int shndx = this->shndx();
5212
5213 // We have to cache original size, alignment and contents to avoid locking
5214 // the original file.
5215 this->original_addralign_ =
5216 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5217
5218 // This is not efficient but we expect only a small number of relaxed
5219 // input sections for stubs.
5220 section_size_type section_size;
5221 const unsigned char* section_contents =
5222 relobj->section_contents(shndx, &section_size, false);
5223 this->original_size_ =
5224 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5225
5226 gold_assert(this->original_contents_ == NULL);
5227 this->original_contents_ = new unsigned char[section_size];
5228 memcpy(this->original_contents_, section_contents, section_size);
5229
5230 // We want to make this look like the original input section after
5231 // output sections are finalized.
5232 Output_section* os = relobj->output_section(shndx);
5233 off_t offset = relobj->output_section_offset(shndx);
5234 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5235 this->set_address(os->address() + offset);
5236 this->set_file_offset(os->offset() + offset);
5237
5238 this->set_current_data_size(this->original_size_);
5239 this->finalize_data_size();
5240 }
5241
5242 template<bool big_endian>
5243 void
5244 Arm_input_section<big_endian>::do_write(Output_file* of)
5245 {
5246 // We have to write out the original section content.
5247 gold_assert(this->original_contents_ != NULL);
5248 of->write(this->offset(), this->original_contents_,
5249 this->original_size_);
5250
5251 // If this owns a stub table and it is not empty, write it.
5252 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5253 this->stub_table_->write(of);
5254 }
5255
5256 // Finalize data size.
5257
5258 template<bool big_endian>
5259 void
5260 Arm_input_section<big_endian>::set_final_data_size()
5261 {
5262 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5263
5264 if (this->is_stub_table_owner())
5265 {
5266 this->stub_table_->finalize_data_size();
5267 off = align_address(off, this->stub_table_->addralign());
5268 off += this->stub_table_->data_size();
5269 }
5270 this->set_data_size(off);
5271 }
5272
5273 // Reset address and file offset.
5274
5275 template<bool big_endian>
5276 void
5277 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5278 {
5279 // Size of the original input section contents.
5280 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5281
5282 // If this is a stub table owner, account for the stub table size.
5283 if (this->is_stub_table_owner())
5284 {
5285 Stub_table<big_endian>* stub_table = this->stub_table_;
5286
5287 // Reset the stub table's address and file offset. The
5288 // current data size for child will be updated after that.
5289 stub_table_->reset_address_and_file_offset();
5290 off = align_address(off, stub_table_->addralign());
5291 off += stub_table->current_data_size();
5292 }
5293
5294 this->set_current_data_size(off);
5295 }
5296
5297 // Arm_exidx_cantunwind methods.
5298
5299 // Write this to Output file OF for a fixed endianness.
5300
5301 template<bool big_endian>
5302 void
5303 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5304 {
5305 off_t offset = this->offset();
5306 const section_size_type oview_size = 8;
5307 unsigned char* const oview = of->get_output_view(offset, oview_size);
5308
5309 Output_section* os = this->relobj_->output_section(this->shndx_);
5310 gold_assert(os != NULL);
5311
5312 Arm_relobj<big_endian>* arm_relobj =
5313 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5314 Arm_address output_offset =
5315 arm_relobj->get_output_section_offset(this->shndx_);
5316 Arm_address section_start;
5317 section_size_type section_size;
5318
5319 // Find out the end of the text section referred by this.
5320 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5321 {
5322 section_start = os->address() + output_offset;
5323 const Arm_exidx_input_section* exidx_input_section =
5324 arm_relobj->exidx_input_section_by_link(this->shndx_);
5325 gold_assert(exidx_input_section != NULL);
5326 section_size =
5327 convert_to_section_size_type(exidx_input_section->text_size());
5328 }
5329 else
5330 {
5331 // Currently this only happens for a relaxed section.
5332 const Output_relaxed_input_section* poris =
5333 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5334 gold_assert(poris != NULL);
5335 section_start = poris->address();
5336 section_size = convert_to_section_size_type(poris->data_size());
5337 }
5338
5339 // We always append this to the end of an EXIDX section.
5340 Arm_address output_address = section_start + section_size;
5341
5342 // Write out the entry. The first word either points to the beginning
5343 // or after the end of a text section. The second word is the special
5344 // EXIDX_CANTUNWIND value.
5345 uint32_t prel31_offset = output_address - this->address();
5346 if (Bits<31>::has_overflow32(offset))
5347 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5348 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5349 prel31_offset & 0x7fffffffU);
5350 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5351 elfcpp::EXIDX_CANTUNWIND);
5352
5353 of->write_output_view(this->offset(), oview_size, oview);
5354 }
5355
5356 // Arm_exidx_merged_section methods.
5357
5358 // Constructor for Arm_exidx_merged_section.
5359 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5360 // SECTION_OFFSET_MAP points to a section offset map describing how
5361 // parts of the input section are mapped to output. DELETED_BYTES is
5362 // the number of bytes deleted from the EXIDX input section.
5363
5364 Arm_exidx_merged_section::Arm_exidx_merged_section(
5365 const Arm_exidx_input_section& exidx_input_section,
5366 const Arm_exidx_section_offset_map& section_offset_map,
5367 uint32_t deleted_bytes)
5368 : Output_relaxed_input_section(exidx_input_section.relobj(),
5369 exidx_input_section.shndx(),
5370 exidx_input_section.addralign()),
5371 exidx_input_section_(exidx_input_section),
5372 section_offset_map_(section_offset_map)
5373 {
5374 // If we retain or discard the whole EXIDX input section, we would
5375 // not be here.
5376 gold_assert(deleted_bytes != 0
5377 && deleted_bytes != this->exidx_input_section_.size());
5378
5379 // Fix size here so that we do not need to implement set_final_data_size.
5380 uint32_t size = exidx_input_section.size() - deleted_bytes;
5381 this->set_data_size(size);
5382 this->fix_data_size();
5383
5384 // Allocate buffer for section contents and build contents.
5385 this->section_contents_ = new unsigned char[size];
5386 }
5387
5388 // Build the contents of a merged EXIDX output section.
5389
5390 void
5391 Arm_exidx_merged_section::build_contents(
5392 const unsigned char* original_contents,
5393 section_size_type original_size)
5394 {
5395 // Go over spans of input offsets and write only those that are not
5396 // discarded.
5397 section_offset_type in_start = 0;
5398 section_offset_type out_start = 0;
5399 section_offset_type in_max =
5400 convert_types<section_offset_type>(original_size);
5401 section_offset_type out_max =
5402 convert_types<section_offset_type>(this->data_size());
5403 for (Arm_exidx_section_offset_map::const_iterator p =
5404 this->section_offset_map_.begin();
5405 p != this->section_offset_map_.end();
5406 ++p)
5407 {
5408 section_offset_type in_end = p->first;
5409 gold_assert(in_end >= in_start);
5410 section_offset_type out_end = p->second;
5411 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5412 if (out_end != -1)
5413 {
5414 size_t out_chunk_size =
5415 convert_types<size_t>(out_end - out_start + 1);
5416
5417 gold_assert(out_chunk_size == in_chunk_size
5418 && in_end < in_max && out_end < out_max);
5419
5420 memcpy(this->section_contents_ + out_start,
5421 original_contents + in_start,
5422 out_chunk_size);
5423 out_start += out_chunk_size;
5424 }
5425 in_start += in_chunk_size;
5426 }
5427 }
5428
5429 // Given an input OBJECT, an input section index SHNDX within that
5430 // object, and an OFFSET relative to the start of that input
5431 // section, return whether or not the corresponding offset within
5432 // the output section is known. If this function returns true, it
5433 // sets *POUTPUT to the output offset. The value -1 indicates that
5434 // this input offset is being discarded.
5435
5436 bool
5437 Arm_exidx_merged_section::do_output_offset(
5438 const Relobj* relobj,
5439 unsigned int shndx,
5440 section_offset_type offset,
5441 section_offset_type* poutput) const
5442 {
5443 // We only handle offsets for the original EXIDX input section.
5444 if (relobj != this->exidx_input_section_.relobj()
5445 || shndx != this->exidx_input_section_.shndx())
5446 return false;
5447
5448 section_offset_type section_size =
5449 convert_types<section_offset_type>(this->exidx_input_section_.size());
5450 if (offset < 0 || offset >= section_size)
5451 // Input offset is out of valid range.
5452 *poutput = -1;
5453 else
5454 {
5455 // We need to look up the section offset map to determine the output
5456 // offset. Find the reference point in map that is first offset
5457 // bigger than or equal to this offset.
5458 Arm_exidx_section_offset_map::const_iterator p =
5459 this->section_offset_map_.lower_bound(offset);
5460
5461 // The section offset maps are build such that this should not happen if
5462 // input offset is in the valid range.
5463 gold_assert(p != this->section_offset_map_.end());
5464
5465 // We need to check if this is dropped.
5466 section_offset_type ref = p->first;
5467 section_offset_type mapped_ref = p->second;
5468
5469 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5470 // Offset is present in output.
5471 *poutput = mapped_ref + (offset - ref);
5472 else
5473 // Offset is discarded owing to EXIDX entry merging.
5474 *poutput = -1;
5475 }
5476
5477 return true;
5478 }
5479
5480 // Write this to output file OF.
5481
5482 void
5483 Arm_exidx_merged_section::do_write(Output_file* of)
5484 {
5485 off_t offset = this->offset();
5486 const section_size_type oview_size = this->data_size();
5487 unsigned char* const oview = of->get_output_view(offset, oview_size);
5488
5489 Output_section* os = this->relobj()->output_section(this->shndx());
5490 gold_assert(os != NULL);
5491
5492 memcpy(oview, this->section_contents_, oview_size);
5493 of->write_output_view(this->offset(), oview_size, oview);
5494 }
5495
5496 // Arm_exidx_fixup methods.
5497
5498 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5499 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5500 // points to the end of the last seen EXIDX section.
5501
5502 void
5503 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5504 {
5505 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5506 && this->last_input_section_ != NULL)
5507 {
5508 Relobj* relobj = this->last_input_section_->relobj();
5509 unsigned int text_shndx = this->last_input_section_->link();
5510 Arm_exidx_cantunwind* cantunwind =
5511 new Arm_exidx_cantunwind(relobj, text_shndx);
5512 this->exidx_output_section_->add_output_section_data(cantunwind);
5513 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5514 }
5515 }
5516
5517 // Process an EXIDX section entry in input. Return whether this entry
5518 // can be deleted in the output. SECOND_WORD in the second word of the
5519 // EXIDX entry.
5520
5521 bool
5522 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5523 {
5524 bool delete_entry;
5525 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5526 {
5527 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5528 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5529 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5530 }
5531 else if ((second_word & 0x80000000) != 0)
5532 {
5533 // Inlined unwinding data. Merge if equal to previous.
5534 delete_entry = (merge_exidx_entries_
5535 && this->last_unwind_type_ == UT_INLINED_ENTRY
5536 && this->last_inlined_entry_ == second_word);
5537 this->last_unwind_type_ = UT_INLINED_ENTRY;
5538 this->last_inlined_entry_ = second_word;
5539 }
5540 else
5541 {
5542 // Normal table entry. In theory we could merge these too,
5543 // but duplicate entries are likely to be much less common.
5544 delete_entry = false;
5545 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5546 }
5547 return delete_entry;
5548 }
5549
5550 // Update the current section offset map during EXIDX section fix-up.
5551 // If there is no map, create one. INPUT_OFFSET is the offset of a
5552 // reference point, DELETED_BYTES is the number of deleted by in the
5553 // section so far. If DELETE_ENTRY is true, the reference point and
5554 // all offsets after the previous reference point are discarded.
5555
5556 void
5557 Arm_exidx_fixup::update_offset_map(
5558 section_offset_type input_offset,
5559 section_size_type deleted_bytes,
5560 bool delete_entry)
5561 {
5562 if (this->section_offset_map_ == NULL)
5563 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5564 section_offset_type output_offset;
5565 if (delete_entry)
5566 output_offset = Arm_exidx_input_section::invalid_offset;
5567 else
5568 output_offset = input_offset - deleted_bytes;
5569 (*this->section_offset_map_)[input_offset] = output_offset;
5570 }
5571
5572 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5573 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5574 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5575 // If some entries are merged, also store a pointer to a newly created
5576 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5577 // owns the map and is responsible for releasing it after use.
5578
5579 template<bool big_endian>
5580 uint32_t
5581 Arm_exidx_fixup::process_exidx_section(
5582 const Arm_exidx_input_section* exidx_input_section,
5583 const unsigned char* section_contents,
5584 section_size_type section_size,
5585 Arm_exidx_section_offset_map** psection_offset_map)
5586 {
5587 Relobj* relobj = exidx_input_section->relobj();
5588 unsigned shndx = exidx_input_section->shndx();
5589
5590 if ((section_size % 8) != 0)
5591 {
5592 // Something is wrong with this section. Better not touch it.
5593 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5594 relobj->name().c_str(), shndx);
5595 this->last_input_section_ = exidx_input_section;
5596 this->last_unwind_type_ = UT_NONE;
5597 return 0;
5598 }
5599
5600 uint32_t deleted_bytes = 0;
5601 bool prev_delete_entry = false;
5602 gold_assert(this->section_offset_map_ == NULL);
5603
5604 for (section_size_type i = 0; i < section_size; i += 8)
5605 {
5606 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5607 const Valtype* wv =
5608 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5609 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5610
5611 bool delete_entry = this->process_exidx_entry(second_word);
5612
5613 // Entry deletion causes changes in output offsets. We use a std::map
5614 // to record these. And entry (x, y) means input offset x
5615 // is mapped to output offset y. If y is invalid_offset, then x is
5616 // dropped in the output. Because of the way std::map::lower_bound
5617 // works, we record the last offset in a region w.r.t to keeping or
5618 // dropping. If there is no entry (x0, y0) for an input offset x0,
5619 // the output offset y0 of it is determined by the output offset y1 of
5620 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5621 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5622 // y0 is also -1.
5623 if (delete_entry != prev_delete_entry && i != 0)
5624 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5625
5626 // Update total deleted bytes for this entry.
5627 if (delete_entry)
5628 deleted_bytes += 8;
5629
5630 prev_delete_entry = delete_entry;
5631 }
5632
5633 // If section offset map is not NULL, make an entry for the end of
5634 // section.
5635 if (this->section_offset_map_ != NULL)
5636 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5637
5638 *psection_offset_map = this->section_offset_map_;
5639 this->section_offset_map_ = NULL;
5640 this->last_input_section_ = exidx_input_section;
5641
5642 // Set the first output text section so that we can link the EXIDX output
5643 // section to it. Ignore any EXIDX input section that is completely merged.
5644 if (this->first_output_text_section_ == NULL
5645 && deleted_bytes != section_size)
5646 {
5647 unsigned int link = exidx_input_section->link();
5648 Output_section* os = relobj->output_section(link);
5649 gold_assert(os != NULL);
5650 this->first_output_text_section_ = os;
5651 }
5652
5653 return deleted_bytes;
5654 }
5655
5656 // Arm_output_section methods.
5657
5658 // Create a stub group for input sections from BEGIN to END. OWNER
5659 // points to the input section to be the owner a new stub table.
5660
5661 template<bool big_endian>
5662 void
5663 Arm_output_section<big_endian>::create_stub_group(
5664 Input_section_list::const_iterator begin,
5665 Input_section_list::const_iterator end,
5666 Input_section_list::const_iterator owner,
5667 Target_arm<big_endian>* target,
5668 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5669 const Task* task)
5670 {
5671 // We use a different kind of relaxed section in an EXIDX section.
5672 // The static casting from Output_relaxed_input_section to
5673 // Arm_input_section is invalid in an EXIDX section. We are okay
5674 // because we should not be calling this for an EXIDX section.
5675 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5676
5677 // Currently we convert ordinary input sections into relaxed sections only
5678 // at this point but we may want to support creating relaxed input section
5679 // very early. So we check here to see if owner is already a relaxed
5680 // section.
5681
5682 Arm_input_section<big_endian>* arm_input_section;
5683 if (owner->is_relaxed_input_section())
5684 {
5685 arm_input_section =
5686 Arm_input_section<big_endian>::as_arm_input_section(
5687 owner->relaxed_input_section());
5688 }
5689 else
5690 {
5691 gold_assert(owner->is_input_section());
5692 // Create a new relaxed input section. We need to lock the original
5693 // file.
5694 Task_lock_obj<Object> tl(task, owner->relobj());
5695 arm_input_section =
5696 target->new_arm_input_section(owner->relobj(), owner->shndx());
5697 new_relaxed_sections->push_back(arm_input_section);
5698 }
5699
5700 // Create a stub table.
5701 Stub_table<big_endian>* stub_table =
5702 target->new_stub_table(arm_input_section);
5703
5704 arm_input_section->set_stub_table(stub_table);
5705
5706 Input_section_list::const_iterator p = begin;
5707 Input_section_list::const_iterator prev_p;
5708
5709 // Look for input sections or relaxed input sections in [begin ... end].
5710 do
5711 {
5712 if (p->is_input_section() || p->is_relaxed_input_section())
5713 {
5714 // The stub table information for input sections live
5715 // in their objects.
5716 Arm_relobj<big_endian>* arm_relobj =
5717 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5718 arm_relobj->set_stub_table(p->shndx(), stub_table);
5719 }
5720 prev_p = p++;
5721 }
5722 while (prev_p != end);
5723 }
5724
5725 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5726 // of stub groups. We grow a stub group by adding input section until the
5727 // size is just below GROUP_SIZE. The last input section will be converted
5728 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5729 // input section after the stub table, effectively double the group size.
5730 //
5731 // This is similar to the group_sections() function in elf32-arm.c but is
5732 // implemented differently.
5733
5734 template<bool big_endian>
5735 void
5736 Arm_output_section<big_endian>::group_sections(
5737 section_size_type group_size,
5738 bool stubs_always_after_branch,
5739 Target_arm<big_endian>* target,
5740 const Task* task)
5741 {
5742 // States for grouping.
5743 typedef enum
5744 {
5745 // No group is being built.
5746 NO_GROUP,
5747 // A group is being built but the stub table is not found yet.
5748 // We keep group a stub group until the size is just under GROUP_SIZE.
5749 // The last input section in the group will be used as the stub table.
5750 FINDING_STUB_SECTION,
5751 // A group is being built and we have already found a stub table.
5752 // We enter this state to grow a stub group by adding input section
5753 // after the stub table. This effectively doubles the group size.
5754 HAS_STUB_SECTION
5755 } State;
5756
5757 // Any newly created relaxed sections are stored here.
5758 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5759
5760 State state = NO_GROUP;
5761 section_size_type off = 0;
5762 section_size_type group_begin_offset = 0;
5763 section_size_type group_end_offset = 0;
5764 section_size_type stub_table_end_offset = 0;
5765 Input_section_list::const_iterator group_begin =
5766 this->input_sections().end();
5767 Input_section_list::const_iterator stub_table =
5768 this->input_sections().end();
5769 Input_section_list::const_iterator group_end = this->input_sections().end();
5770 for (Input_section_list::const_iterator p = this->input_sections().begin();
5771 p != this->input_sections().end();
5772 ++p)
5773 {
5774 section_size_type section_begin_offset =
5775 align_address(off, p->addralign());
5776 section_size_type section_end_offset =
5777 section_begin_offset + p->data_size();
5778
5779 // Check to see if we should group the previously seen sections.
5780 switch (state)
5781 {
5782 case NO_GROUP:
5783 break;
5784
5785 case FINDING_STUB_SECTION:
5786 // Adding this section makes the group larger than GROUP_SIZE.
5787 if (section_end_offset - group_begin_offset >= group_size)
5788 {
5789 if (stubs_always_after_branch)
5790 {
5791 gold_assert(group_end != this->input_sections().end());
5792 this->create_stub_group(group_begin, group_end, group_end,
5793 target, &new_relaxed_sections,
5794 task);
5795 state = NO_GROUP;
5796 }
5797 else
5798 {
5799 // But wait, there's more! Input sections up to
5800 // stub_group_size bytes after the stub table can be
5801 // handled by it too.
5802 state = HAS_STUB_SECTION;
5803 stub_table = group_end;
5804 stub_table_end_offset = group_end_offset;
5805 }
5806 }
5807 break;
5808
5809 case HAS_STUB_SECTION:
5810 // Adding this section makes the post stub-section group larger
5811 // than GROUP_SIZE.
5812 if (section_end_offset - stub_table_end_offset >= group_size)
5813 {
5814 gold_assert(group_end != this->input_sections().end());
5815 this->create_stub_group(group_begin, group_end, stub_table,
5816 target, &new_relaxed_sections, task);
5817 state = NO_GROUP;
5818 }
5819 break;
5820
5821 default:
5822 gold_unreachable();
5823 }
5824
5825 // If we see an input section and currently there is no group, start
5826 // a new one. Skip any empty sections. We look at the data size
5827 // instead of calling p->relobj()->section_size() to avoid locking.
5828 if ((p->is_input_section() || p->is_relaxed_input_section())
5829 && (p->data_size() != 0))
5830 {
5831 if (state == NO_GROUP)
5832 {
5833 state = FINDING_STUB_SECTION;
5834 group_begin = p;
5835 group_begin_offset = section_begin_offset;
5836 }
5837
5838 // Keep track of the last input section seen.
5839 group_end = p;
5840 group_end_offset = section_end_offset;
5841 }
5842
5843 off = section_end_offset;
5844 }
5845
5846 // Create a stub group for any ungrouped sections.
5847 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5848 {
5849 gold_assert(group_end != this->input_sections().end());
5850 this->create_stub_group(group_begin, group_end,
5851 (state == FINDING_STUB_SECTION
5852 ? group_end
5853 : stub_table),
5854 target, &new_relaxed_sections, task);
5855 }
5856
5857 // Convert input section into relaxed input section in a batch.
5858 if (!new_relaxed_sections.empty())
5859 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5860
5861 // Update the section offsets
5862 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5863 {
5864 Arm_relobj<big_endian>* arm_relobj =
5865 Arm_relobj<big_endian>::as_arm_relobj(
5866 new_relaxed_sections[i]->relobj());
5867 unsigned int shndx = new_relaxed_sections[i]->shndx();
5868 // Tell Arm_relobj that this input section is converted.
5869 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5870 }
5871 }
5872
5873 // Append non empty text sections in this to LIST in ascending
5874 // order of their position in this.
5875
5876 template<bool big_endian>
5877 void
5878 Arm_output_section<big_endian>::append_text_sections_to_list(
5879 Text_section_list* list)
5880 {
5881 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5882
5883 for (Input_section_list::const_iterator p = this->input_sections().begin();
5884 p != this->input_sections().end();
5885 ++p)
5886 {
5887 // We only care about plain or relaxed input sections. We also
5888 // ignore any merged sections.
5889 if (p->is_input_section() || p->is_relaxed_input_section())
5890 list->push_back(Text_section_list::value_type(p->relobj(),
5891 p->shndx()));
5892 }
5893 }
5894
5895 template<bool big_endian>
5896 void
5897 Arm_output_section<big_endian>::fix_exidx_coverage(
5898 Layout* layout,
5899 const Text_section_list& sorted_text_sections,
5900 Symbol_table* symtab,
5901 bool merge_exidx_entries,
5902 const Task* task)
5903 {
5904 // We should only do this for the EXIDX output section.
5905 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5906
5907 // We don't want the relaxation loop to undo these changes, so we discard
5908 // the current saved states and take another one after the fix-up.
5909 this->discard_states();
5910
5911 // Remove all input sections.
5912 uint64_t address = this->address();
5913 typedef std::list<Output_section::Input_section> Input_section_list;
5914 Input_section_list input_sections;
5915 this->reset_address_and_file_offset();
5916 this->get_input_sections(address, std::string(""), &input_sections);
5917
5918 if (!this->input_sections().empty())
5919 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5920
5921 // Go through all the known input sections and record them.
5922 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5923 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5924 Section_id_hash> Text_to_exidx_map;
5925 Text_to_exidx_map text_to_exidx_map;
5926 for (Input_section_list::const_iterator p = input_sections.begin();
5927 p != input_sections.end();
5928 ++p)
5929 {
5930 // This should never happen. At this point, we should only see
5931 // plain EXIDX input sections.
5932 gold_assert(!p->is_relaxed_input_section());
5933 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5934 }
5935
5936 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5937
5938 // Go over the sorted text sections.
5939 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5940 Section_id_set processed_input_sections;
5941 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5942 p != sorted_text_sections.end();
5943 ++p)
5944 {
5945 Relobj* relobj = p->first;
5946 unsigned int shndx = p->second;
5947
5948 Arm_relobj<big_endian>* arm_relobj =
5949 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5950 const Arm_exidx_input_section* exidx_input_section =
5951 arm_relobj->exidx_input_section_by_link(shndx);
5952
5953 // If this text section has no EXIDX section or if the EXIDX section
5954 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5955 // of the last seen EXIDX section.
5956 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5957 {
5958 exidx_fixup.add_exidx_cantunwind_as_needed();
5959 continue;
5960 }
5961
5962 Relobj* exidx_relobj = exidx_input_section->relobj();
5963 unsigned int exidx_shndx = exidx_input_section->shndx();
5964 Section_id sid(exidx_relobj, exidx_shndx);
5965 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5966 if (iter == text_to_exidx_map.end())
5967 {
5968 // This is odd. We have not seen this EXIDX input section before.
5969 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5970 // issue a warning instead. We assume the user knows what he
5971 // or she is doing. Otherwise, this is an error.
5972 if (layout->script_options()->saw_sections_clause())
5973 gold_warning(_("unwinding may not work because EXIDX input section"
5974 " %u of %s is not in EXIDX output section"),
5975 exidx_shndx, exidx_relobj->name().c_str());
5976 else
5977 gold_error(_("unwinding may not work because EXIDX input section"
5978 " %u of %s is not in EXIDX output section"),
5979 exidx_shndx, exidx_relobj->name().c_str());
5980
5981 exidx_fixup.add_exidx_cantunwind_as_needed();
5982 continue;
5983 }
5984
5985 // We need to access the contents of the EXIDX section, lock the
5986 // object here.
5987 Task_lock_obj<Object> tl(task, exidx_relobj);
5988 section_size_type exidx_size;
5989 const unsigned char* exidx_contents =
5990 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5991
5992 // Fix up coverage and append input section to output data list.
5993 Arm_exidx_section_offset_map* section_offset_map = NULL;
5994 uint32_t deleted_bytes =
5995 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5996 exidx_contents,
5997 exidx_size,
5998 &section_offset_map);
5999
6000 if (deleted_bytes == exidx_input_section->size())
6001 {
6002 // The whole EXIDX section got merged. Remove it from output.
6003 gold_assert(section_offset_map == NULL);
6004 exidx_relobj->set_output_section(exidx_shndx, NULL);
6005
6006 // All local symbols defined in this input section will be dropped.
6007 // We need to adjust output local symbol count.
6008 arm_relobj->set_output_local_symbol_count_needs_update();
6009 }
6010 else if (deleted_bytes > 0)
6011 {
6012 // Some entries are merged. We need to convert this EXIDX input
6013 // section into a relaxed section.
6014 gold_assert(section_offset_map != NULL);
6015
6016 Arm_exidx_merged_section* merged_section =
6017 new Arm_exidx_merged_section(*exidx_input_section,
6018 *section_offset_map, deleted_bytes);
6019 merged_section->build_contents(exidx_contents, exidx_size);
6020
6021 const std::string secname = exidx_relobj->section_name(exidx_shndx);
6022 this->add_relaxed_input_section(layout, merged_section, secname);
6023 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
6024
6025 // All local symbols defined in discarded portions of this input
6026 // section will be dropped. We need to adjust output local symbol
6027 // count.
6028 arm_relobj->set_output_local_symbol_count_needs_update();
6029 }
6030 else
6031 {
6032 // Just add back the EXIDX input section.
6033 gold_assert(section_offset_map == NULL);
6034 const Output_section::Input_section* pis = iter->second;
6035 gold_assert(pis->is_input_section());
6036 this->add_script_input_section(*pis);
6037 }
6038
6039 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
6040 }
6041
6042 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
6043 exidx_fixup.add_exidx_cantunwind_as_needed();
6044
6045 // Remove any known EXIDX input sections that are not processed.
6046 for (Input_section_list::const_iterator p = input_sections.begin();
6047 p != input_sections.end();
6048 ++p)
6049 {
6050 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
6051 == processed_input_sections.end())
6052 {
6053 // We discard a known EXIDX section because its linked
6054 // text section has been folded by ICF. We also discard an
6055 // EXIDX section with error, the output does not matter in this
6056 // case. We do this to avoid triggering asserts.
6057 Arm_relobj<big_endian>* arm_relobj =
6058 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6059 const Arm_exidx_input_section* exidx_input_section =
6060 arm_relobj->exidx_input_section_by_shndx(p->shndx());
6061 gold_assert(exidx_input_section != NULL);
6062 if (!exidx_input_section->has_errors())
6063 {
6064 unsigned int text_shndx = exidx_input_section->link();
6065 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
6066 }
6067
6068 // Remove this from link. We also need to recount the
6069 // local symbols.
6070 p->relobj()->set_output_section(p->shndx(), NULL);
6071 arm_relobj->set_output_local_symbol_count_needs_update();
6072 }
6073 }
6074
6075 // Link exidx output section to the first seen output section and
6076 // set correct entry size.
6077 this->set_link_section(exidx_fixup.first_output_text_section());
6078 this->set_entsize(8);
6079
6080 // Make changes permanent.
6081 this->save_states();
6082 this->set_section_offsets_need_adjustment();
6083 }
6084
6085 // Link EXIDX output sections to text output sections.
6086
6087 template<bool big_endian>
6088 void
6089 Arm_output_section<big_endian>::set_exidx_section_link()
6090 {
6091 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6092 if (!this->input_sections().empty())
6093 {
6094 Input_section_list::const_iterator p = this->input_sections().begin();
6095 Arm_relobj<big_endian>* arm_relobj =
6096 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6097 unsigned exidx_shndx = p->shndx();
6098 const Arm_exidx_input_section* exidx_input_section =
6099 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6100 gold_assert(exidx_input_section != NULL);
6101 unsigned int text_shndx = exidx_input_section->link();
6102 Output_section* os = arm_relobj->output_section(text_shndx);
6103 this->set_link_section(os);
6104 }
6105 }
6106
6107 // Arm_relobj methods.
6108
6109 // Determine if an input section is scannable for stub processing. SHDR is
6110 // the header of the section and SHNDX is the section index. OS is the output
6111 // section for the input section and SYMTAB is the global symbol table used to
6112 // look up ICF information.
6113
6114 template<bool big_endian>
6115 bool
6116 Arm_relobj<big_endian>::section_is_scannable(
6117 const elfcpp::Shdr<32, big_endian>& shdr,
6118 unsigned int shndx,
6119 const Output_section* os,
6120 const Symbol_table* symtab)
6121 {
6122 // Skip any empty sections, unallocated sections or sections whose
6123 // type are not SHT_PROGBITS.
6124 if (shdr.get_sh_size() == 0
6125 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6126 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6127 return false;
6128
6129 // Skip any discarded or ICF'ed sections.
6130 if (os == NULL || symtab->is_section_folded(this, shndx))
6131 return false;
6132
6133 // If this requires special offset handling, check to see if it is
6134 // a relaxed section. If this is not, then it is a merged section that
6135 // we cannot handle.
6136 if (this->is_output_section_offset_invalid(shndx))
6137 {
6138 const Output_relaxed_input_section* poris =
6139 os->find_relaxed_input_section(this, shndx);
6140 if (poris == NULL)
6141 return false;
6142 }
6143
6144 return true;
6145 }
6146
6147 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6148 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6149
6150 template<bool big_endian>
6151 bool
6152 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6153 const elfcpp::Shdr<32, big_endian>& shdr,
6154 const Relobj::Output_sections& out_sections,
6155 const Symbol_table* symtab,
6156 const unsigned char* pshdrs)
6157 {
6158 unsigned int sh_type = shdr.get_sh_type();
6159 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6160 return false;
6161
6162 // Ignore empty section.
6163 off_t sh_size = shdr.get_sh_size();
6164 if (sh_size == 0)
6165 return false;
6166
6167 // Ignore reloc section with unexpected symbol table. The
6168 // error will be reported in the final link.
6169 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6170 return false;
6171
6172 unsigned int reloc_size;
6173 if (sh_type == elfcpp::SHT_REL)
6174 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6175 else
6176 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6177
6178 // Ignore reloc section with unexpected entsize or uneven size.
6179 // The error will be reported in the final link.
6180 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6181 return false;
6182
6183 // Ignore reloc section with bad info. This error will be
6184 // reported in the final link.
6185 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6186 if (index >= this->shnum())
6187 return false;
6188
6189 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6190 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6191 return this->section_is_scannable(text_shdr, index,
6192 out_sections[index], symtab);
6193 }
6194
6195 // Return the output address of either a plain input section or a relaxed
6196 // input section. SHNDX is the section index. We define and use this
6197 // instead of calling Output_section::output_address because that is slow
6198 // for large output.
6199
6200 template<bool big_endian>
6201 Arm_address
6202 Arm_relobj<big_endian>::simple_input_section_output_address(
6203 unsigned int shndx,
6204 Output_section* os)
6205 {
6206 if (this->is_output_section_offset_invalid(shndx))
6207 {
6208 const Output_relaxed_input_section* poris =
6209 os->find_relaxed_input_section(this, shndx);
6210 // We do not handle merged sections here.
6211 gold_assert(poris != NULL);
6212 return poris->address();
6213 }
6214 else
6215 return os->address() + this->get_output_section_offset(shndx);
6216 }
6217
6218 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6219 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6220
6221 template<bool big_endian>
6222 bool
6223 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6224 const elfcpp::Shdr<32, big_endian>& shdr,
6225 unsigned int shndx,
6226 Output_section* os,
6227 const Symbol_table* symtab)
6228 {
6229 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6230 return false;
6231
6232 // If the section does not cross any 4K-boundaries, it does not need to
6233 // be scanned.
6234 Arm_address address = this->simple_input_section_output_address(shndx, os);
6235 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6236 return false;
6237
6238 return true;
6239 }
6240
6241 // Scan a section for Cortex-A8 workaround.
6242
6243 template<bool big_endian>
6244 void
6245 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6246 const elfcpp::Shdr<32, big_endian>& shdr,
6247 unsigned int shndx,
6248 Output_section* os,
6249 Target_arm<big_endian>* arm_target)
6250 {
6251 // Look for the first mapping symbol in this section. It should be
6252 // at (shndx, 0).
6253 Mapping_symbol_position section_start(shndx, 0);
6254 typename Mapping_symbols_info::const_iterator p =
6255 this->mapping_symbols_info_.lower_bound(section_start);
6256
6257 // There are no mapping symbols for this section. Treat it as a data-only
6258 // section.
6259 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6260 return;
6261
6262 Arm_address output_address =
6263 this->simple_input_section_output_address(shndx, os);
6264
6265 // Get the section contents.
6266 section_size_type input_view_size = 0;
6267 const unsigned char* input_view =
6268 this->section_contents(shndx, &input_view_size, false);
6269
6270 // We need to go through the mapping symbols to determine what to
6271 // scan. There are two reasons. First, we should look at THUMB code and
6272 // THUMB code only. Second, we only want to look at the 4K-page boundary
6273 // to speed up the scanning.
6274
6275 while (p != this->mapping_symbols_info_.end()
6276 && p->first.first == shndx)
6277 {
6278 typename Mapping_symbols_info::const_iterator next =
6279 this->mapping_symbols_info_.upper_bound(p->first);
6280
6281 // Only scan part of a section with THUMB code.
6282 if (p->second == 't')
6283 {
6284 // Determine the end of this range.
6285 section_size_type span_start =
6286 convert_to_section_size_type(p->first.second);
6287 section_size_type span_end;
6288 if (next != this->mapping_symbols_info_.end()
6289 && next->first.first == shndx)
6290 span_end = convert_to_section_size_type(next->first.second);
6291 else
6292 span_end = convert_to_section_size_type(shdr.get_sh_size());
6293
6294 if (((span_start + output_address) & ~0xfffUL)
6295 != ((span_end + output_address - 1) & ~0xfffUL))
6296 {
6297 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6298 span_start, span_end,
6299 input_view,
6300 output_address);
6301 }
6302 }
6303
6304 p = next;
6305 }
6306 }
6307
6308 // Scan relocations for stub generation.
6309
6310 template<bool big_endian>
6311 void
6312 Arm_relobj<big_endian>::scan_sections_for_stubs(
6313 Target_arm<big_endian>* arm_target,
6314 const Symbol_table* symtab,
6315 const Layout* layout)
6316 {
6317 unsigned int shnum = this->shnum();
6318 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6319
6320 // Read the section headers.
6321 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6322 shnum * shdr_size,
6323 true, true);
6324
6325 // To speed up processing, we set up hash tables for fast lookup of
6326 // input offsets to output addresses.
6327 this->initialize_input_to_output_maps();
6328
6329 const Relobj::Output_sections& out_sections(this->output_sections());
6330
6331 Relocate_info<32, big_endian> relinfo;
6332 relinfo.symtab = symtab;
6333 relinfo.layout = layout;
6334 relinfo.object = this;
6335
6336 // Do relocation stubs scanning.
6337 const unsigned char* p = pshdrs + shdr_size;
6338 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6339 {
6340 const elfcpp::Shdr<32, big_endian> shdr(p);
6341 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6342 pshdrs))
6343 {
6344 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6345 Arm_address output_offset = this->get_output_section_offset(index);
6346 Arm_address output_address;
6347 if (output_offset != invalid_address)
6348 output_address = out_sections[index]->address() + output_offset;
6349 else
6350 {
6351 // Currently this only happens for a relaxed section.
6352 const Output_relaxed_input_section* poris =
6353 out_sections[index]->find_relaxed_input_section(this, index);
6354 gold_assert(poris != NULL);
6355 output_address = poris->address();
6356 }
6357
6358 // Get the relocations.
6359 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6360 shdr.get_sh_size(),
6361 true, false);
6362
6363 // Get the section contents. This does work for the case in which
6364 // we modify the contents of an input section. We need to pass the
6365 // output view under such circumstances.
6366 section_size_type input_view_size = 0;
6367 const unsigned char* input_view =
6368 this->section_contents(index, &input_view_size, false);
6369
6370 relinfo.reloc_shndx = i;
6371 relinfo.data_shndx = index;
6372 unsigned int sh_type = shdr.get_sh_type();
6373 unsigned int reloc_size;
6374 if (sh_type == elfcpp::SHT_REL)
6375 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6376 else
6377 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6378
6379 Output_section* os = out_sections[index];
6380 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6381 shdr.get_sh_size() / reloc_size,
6382 os,
6383 output_offset == invalid_address,
6384 input_view, output_address,
6385 input_view_size);
6386 }
6387 }
6388
6389 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6390 // after its relocation section, if there is one, is processed for
6391 // relocation stubs. Merging this loop with the one above would have been
6392 // complicated since we would have had to make sure that relocation stub
6393 // scanning is done first.
6394 if (arm_target->fix_cortex_a8())
6395 {
6396 const unsigned char* p = pshdrs + shdr_size;
6397 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6398 {
6399 const elfcpp::Shdr<32, big_endian> shdr(p);
6400 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6401 out_sections[i],
6402 symtab))
6403 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6404 arm_target);
6405 }
6406 }
6407
6408 // After we've done the relocations, we release the hash tables,
6409 // since we no longer need them.
6410 this->free_input_to_output_maps();
6411 }
6412
6413 // Count the local symbols. The ARM backend needs to know if a symbol
6414 // is a THUMB function or not. For global symbols, it is easy because
6415 // the Symbol object keeps the ELF symbol type. For local symbol it is
6416 // harder because we cannot access this information. So we override the
6417 // do_count_local_symbol in parent and scan local symbols to mark
6418 // THUMB functions. This is not the most efficient way but I do not want to
6419 // slow down other ports by calling a per symbol target hook inside
6420 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6421
6422 template<bool big_endian>
6423 void
6424 Arm_relobj<big_endian>::do_count_local_symbols(
6425 Stringpool_template<char>* pool,
6426 Stringpool_template<char>* dynpool)
6427 {
6428 // We need to fix-up the values of any local symbols whose type are
6429 // STT_ARM_TFUNC.
6430
6431 // Ask parent to count the local symbols.
6432 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6433 const unsigned int loccount = this->local_symbol_count();
6434 if (loccount == 0)
6435 return;
6436
6437 // Initialize the thumb function bit-vector.
6438 std::vector<bool> empty_vector(loccount, false);
6439 this->local_symbol_is_thumb_function_.swap(empty_vector);
6440
6441 // Read the symbol table section header.
6442 const unsigned int symtab_shndx = this->symtab_shndx();
6443 elfcpp::Shdr<32, big_endian>
6444 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6445 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6446
6447 // Read the local symbols.
6448 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6449 gold_assert(loccount == symtabshdr.get_sh_info());
6450 off_t locsize = loccount * sym_size;
6451 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6452 locsize, true, true);
6453
6454 // For mapping symbol processing, we need to read the symbol names.
6455 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6456 if (strtab_shndx >= this->shnum())
6457 {
6458 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6459 return;
6460 }
6461
6462 elfcpp::Shdr<32, big_endian>
6463 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6464 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6465 {
6466 this->error(_("symbol table name section has wrong type: %u"),
6467 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6468 return;
6469 }
6470 const char* pnames =
6471 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6472 strtabshdr.get_sh_size(),
6473 false, false));
6474
6475 // Loop over the local symbols and mark any local symbols pointing
6476 // to THUMB functions.
6477
6478 // Skip the first dummy symbol.
6479 psyms += sym_size;
6480 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6481 this->local_values();
6482 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6483 {
6484 elfcpp::Sym<32, big_endian> sym(psyms);
6485 elfcpp::STT st_type = sym.get_st_type();
6486 Symbol_value<32>& lv((*plocal_values)[i]);
6487 Arm_address input_value = lv.input_value();
6488
6489 // Check to see if this is a mapping symbol.
6490 const char* sym_name = pnames + sym.get_st_name();
6491 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6492 {
6493 bool is_ordinary;
6494 unsigned int input_shndx =
6495 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6496 gold_assert(is_ordinary);
6497
6498 // Strip of LSB in case this is a THUMB symbol.
6499 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6500 this->mapping_symbols_info_[msp] = sym_name[1];
6501 }
6502
6503 if (st_type == elfcpp::STT_ARM_TFUNC
6504 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6505 {
6506 // This is a THUMB function. Mark this and canonicalize the
6507 // symbol value by setting LSB.
6508 this->local_symbol_is_thumb_function_[i] = true;
6509 if ((input_value & 1) == 0)
6510 lv.set_input_value(input_value | 1);
6511 }
6512 }
6513 }
6514
6515 // Relocate sections.
6516 template<bool big_endian>
6517 void
6518 Arm_relobj<big_endian>::do_relocate_sections(
6519 const Symbol_table* symtab,
6520 const Layout* layout,
6521 const unsigned char* pshdrs,
6522 Output_file* of,
6523 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6524 {
6525 // Call parent to relocate sections.
6526 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6527 pshdrs, of, pviews);
6528
6529 // We do not generate stubs if doing a relocatable link.
6530 if (parameters->options().relocatable())
6531 return;
6532
6533 // Relocate stub tables.
6534 unsigned int shnum = this->shnum();
6535
6536 Target_arm<big_endian>* arm_target =
6537 Target_arm<big_endian>::default_target();
6538
6539 Relocate_info<32, big_endian> relinfo;
6540 relinfo.symtab = symtab;
6541 relinfo.layout = layout;
6542 relinfo.object = this;
6543
6544 for (unsigned int i = 1; i < shnum; ++i)
6545 {
6546 Arm_input_section<big_endian>* arm_input_section =
6547 arm_target->find_arm_input_section(this, i);
6548
6549 if (arm_input_section != NULL
6550 && arm_input_section->is_stub_table_owner()
6551 && !arm_input_section->stub_table()->empty())
6552 {
6553 // We cannot discard a section if it owns a stub table.
6554 Output_section* os = this->output_section(i);
6555 gold_assert(os != NULL);
6556
6557 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6558 relinfo.reloc_shdr = NULL;
6559 relinfo.data_shndx = i;
6560 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6561
6562 gold_assert((*pviews)[i].view != NULL);
6563
6564 // We are passed the output section view. Adjust it to cover the
6565 // stub table only.
6566 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6567 gold_assert((stub_table->address() >= (*pviews)[i].address)
6568 && ((stub_table->address() + stub_table->data_size())
6569 <= (*pviews)[i].address + (*pviews)[i].view_size));
6570
6571 off_t offset = stub_table->address() - (*pviews)[i].address;
6572 unsigned char* view = (*pviews)[i].view + offset;
6573 Arm_address address = stub_table->address();
6574 section_size_type view_size = stub_table->data_size();
6575
6576 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6577 view_size);
6578 }
6579
6580 // Apply Cortex A8 workaround if applicable.
6581 if (this->section_has_cortex_a8_workaround(i))
6582 {
6583 unsigned char* view = (*pviews)[i].view;
6584 Arm_address view_address = (*pviews)[i].address;
6585 section_size_type view_size = (*pviews)[i].view_size;
6586 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6587
6588 // Adjust view to cover section.
6589 Output_section* os = this->output_section(i);
6590 gold_assert(os != NULL);
6591 Arm_address section_address =
6592 this->simple_input_section_output_address(i, os);
6593 uint64_t section_size = this->section_size(i);
6594
6595 gold_assert(section_address >= view_address
6596 && ((section_address + section_size)
6597 <= (view_address + view_size)));
6598
6599 unsigned char* section_view = view + (section_address - view_address);
6600
6601 // Apply the Cortex-A8 workaround to the output address range
6602 // corresponding to this input section.
6603 stub_table->apply_cortex_a8_workaround_to_address_range(
6604 arm_target,
6605 section_view,
6606 section_address,
6607 section_size);
6608 }
6609 }
6610 }
6611
6612 // Find the linked text section of an EXIDX section by looking at the first
6613 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6614 // must be linked to its associated code section via the sh_link field of
6615 // its section header. However, some tools are broken and the link is not
6616 // always set. LD just drops such an EXIDX section silently, causing the
6617 // associated code not unwindabled. Here we try a little bit harder to
6618 // discover the linked code section.
6619 //
6620 // PSHDR points to the section header of a relocation section of an EXIDX
6621 // section. If we can find a linked text section, return true and
6622 // store the text section index in the location PSHNDX. Otherwise
6623 // return false.
6624
6625 template<bool big_endian>
6626 bool
6627 Arm_relobj<big_endian>::find_linked_text_section(
6628 const unsigned char* pshdr,
6629 const unsigned char* psyms,
6630 unsigned int* pshndx)
6631 {
6632 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6633
6634 // If there is no relocation, we cannot find the linked text section.
6635 size_t reloc_size;
6636 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6637 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6638 else
6639 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6640 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6641
6642 // Get the relocations.
6643 const unsigned char* prelocs =
6644 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6645
6646 // Find the REL31 relocation for the first word of the first EXIDX entry.
6647 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6648 {
6649 Arm_address r_offset;
6650 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6651 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6652 {
6653 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6654 r_info = reloc.get_r_info();
6655 r_offset = reloc.get_r_offset();
6656 }
6657 else
6658 {
6659 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6660 r_info = reloc.get_r_info();
6661 r_offset = reloc.get_r_offset();
6662 }
6663
6664 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6665 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6666 continue;
6667
6668 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6669 if (r_sym == 0
6670 || r_sym >= this->local_symbol_count()
6671 || r_offset != 0)
6672 continue;
6673
6674 // This is the relocation for the first word of the first EXIDX entry.
6675 // We expect to see a local section symbol.
6676 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6677 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6678 if (sym.get_st_type() == elfcpp::STT_SECTION)
6679 {
6680 bool is_ordinary;
6681 *pshndx =
6682 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6683 gold_assert(is_ordinary);
6684 return true;
6685 }
6686 else
6687 return false;
6688 }
6689
6690 return false;
6691 }
6692
6693 // Make an EXIDX input section object for an EXIDX section whose index is
6694 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6695 // is the section index of the linked text section.
6696
6697 template<bool big_endian>
6698 void
6699 Arm_relobj<big_endian>::make_exidx_input_section(
6700 unsigned int shndx,
6701 const elfcpp::Shdr<32, big_endian>& shdr,
6702 unsigned int text_shndx,
6703 const elfcpp::Shdr<32, big_endian>& text_shdr)
6704 {
6705 // Create an Arm_exidx_input_section object for this EXIDX section.
6706 Arm_exidx_input_section* exidx_input_section =
6707 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6708 shdr.get_sh_addralign(),
6709 text_shdr.get_sh_size());
6710
6711 gold_assert(this->exidx_section_map_[shndx] == NULL);
6712 this->exidx_section_map_[shndx] = exidx_input_section;
6713
6714 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6715 {
6716 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6717 this->section_name(shndx).c_str(), shndx, text_shndx,
6718 this->name().c_str());
6719 exidx_input_section->set_has_errors();
6720 }
6721 else if (this->exidx_section_map_[text_shndx] != NULL)
6722 {
6723 unsigned other_exidx_shndx =
6724 this->exidx_section_map_[text_shndx]->shndx();
6725 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6726 "%s(%u) in %s"),
6727 this->section_name(shndx).c_str(), shndx,
6728 this->section_name(other_exidx_shndx).c_str(),
6729 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6730 text_shndx, this->name().c_str());
6731 exidx_input_section->set_has_errors();
6732 }
6733 else
6734 this->exidx_section_map_[text_shndx] = exidx_input_section;
6735
6736 // Check section flags of text section.
6737 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6738 {
6739 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6740 " in %s"),
6741 this->section_name(shndx).c_str(), shndx,
6742 this->section_name(text_shndx).c_str(), text_shndx,
6743 this->name().c_str());
6744 exidx_input_section->set_has_errors();
6745 }
6746 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6747 // I would like to make this an error but currently ld just ignores
6748 // this.
6749 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6750 "%s(%u) in %s"),
6751 this->section_name(shndx).c_str(), shndx,
6752 this->section_name(text_shndx).c_str(), text_shndx,
6753 this->name().c_str());
6754 }
6755
6756 // Read the symbol information.
6757
6758 template<bool big_endian>
6759 void
6760 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6761 {
6762 // Call parent class to read symbol information.
6763 this->base_read_symbols(sd);
6764
6765 // If this input file is a binary file, it has no processor
6766 // specific flags and attributes section.
6767 Input_file::Format format = this->input_file()->format();
6768 if (format != Input_file::FORMAT_ELF)
6769 {
6770 gold_assert(format == Input_file::FORMAT_BINARY);
6771 this->merge_flags_and_attributes_ = false;
6772 return;
6773 }
6774
6775 // Read processor-specific flags in ELF file header.
6776 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6777 elfcpp::Elf_sizes<32>::ehdr_size,
6778 true, false);
6779 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6780 this->processor_specific_flags_ = ehdr.get_e_flags();
6781
6782 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6783 // sections.
6784 std::vector<unsigned int> deferred_exidx_sections;
6785 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6786 const unsigned char* pshdrs = sd->section_headers->data();
6787 const unsigned char* ps = pshdrs + shdr_size;
6788 bool must_merge_flags_and_attributes = false;
6789 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6790 {
6791 elfcpp::Shdr<32, big_endian> shdr(ps);
6792
6793 // Sometimes an object has no contents except the section name string
6794 // table and an empty symbol table with the undefined symbol. We
6795 // don't want to merge processor-specific flags from such an object.
6796 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6797 {
6798 // Symbol table is not empty.
6799 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6800 elfcpp::Elf_sizes<32>::sym_size;
6801 if (shdr.get_sh_size() > sym_size)
6802 must_merge_flags_and_attributes = true;
6803 }
6804 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6805 // If this is neither an empty symbol table nor a string table,
6806 // be conservative.
6807 must_merge_flags_and_attributes = true;
6808
6809 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6810 {
6811 gold_assert(this->attributes_section_data_ == NULL);
6812 section_offset_type section_offset = shdr.get_sh_offset();
6813 section_size_type section_size =
6814 convert_to_section_size_type(shdr.get_sh_size());
6815 const unsigned char* view =
6816 this->get_view(section_offset, section_size, true, false);
6817 this->attributes_section_data_ =
6818 new Attributes_section_data(view, section_size);
6819 }
6820 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6821 {
6822 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6823 if (text_shndx == elfcpp::SHN_UNDEF)
6824 deferred_exidx_sections.push_back(i);
6825 else
6826 {
6827 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6828 + text_shndx * shdr_size);
6829 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6830 }
6831 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6832 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6833 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6834 this->section_name(i).c_str(), this->name().c_str());
6835 }
6836 }
6837
6838 // This is rare.
6839 if (!must_merge_flags_and_attributes)
6840 {
6841 gold_assert(deferred_exidx_sections.empty());
6842 this->merge_flags_and_attributes_ = false;
6843 return;
6844 }
6845
6846 // Some tools are broken and they do not set the link of EXIDX sections.
6847 // We look at the first relocation to figure out the linked sections.
6848 if (!deferred_exidx_sections.empty())
6849 {
6850 // We need to go over the section headers again to find the mapping
6851 // from sections being relocated to their relocation sections. This is
6852 // a bit inefficient as we could do that in the loop above. However,
6853 // we do not expect any deferred EXIDX sections normally. So we do not
6854 // want to slow down the most common path.
6855 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6856 Reloc_map reloc_map;
6857 ps = pshdrs + shdr_size;
6858 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6859 {
6860 elfcpp::Shdr<32, big_endian> shdr(ps);
6861 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6862 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6863 {
6864 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6865 if (info_shndx >= this->shnum())
6866 gold_error(_("relocation section %u has invalid info %u"),
6867 i, info_shndx);
6868 Reloc_map::value_type value(info_shndx, i);
6869 std::pair<Reloc_map::iterator, bool> result =
6870 reloc_map.insert(value);
6871 if (!result.second)
6872 gold_error(_("section %u has multiple relocation sections "
6873 "%u and %u"),
6874 info_shndx, i, reloc_map[info_shndx]);
6875 }
6876 }
6877
6878 // Read the symbol table section header.
6879 const unsigned int symtab_shndx = this->symtab_shndx();
6880 elfcpp::Shdr<32, big_endian>
6881 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6882 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6883
6884 // Read the local symbols.
6885 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6886 const unsigned int loccount = this->local_symbol_count();
6887 gold_assert(loccount == symtabshdr.get_sh_info());
6888 off_t locsize = loccount * sym_size;
6889 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6890 locsize, true, true);
6891
6892 // Process the deferred EXIDX sections.
6893 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6894 {
6895 unsigned int shndx = deferred_exidx_sections[i];
6896 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6897 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6898 Reloc_map::const_iterator it = reloc_map.find(shndx);
6899 if (it != reloc_map.end())
6900 find_linked_text_section(pshdrs + it->second * shdr_size,
6901 psyms, &text_shndx);
6902 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6903 + text_shndx * shdr_size);
6904 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6905 }
6906 }
6907 }
6908
6909 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6910 // sections for unwinding. These sections are referenced implicitly by
6911 // text sections linked in the section headers. If we ignore these implicit
6912 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6913 // will be garbage-collected incorrectly. Hence we override the same function
6914 // in the base class to handle these implicit references.
6915
6916 template<bool big_endian>
6917 void
6918 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6919 Layout* layout,
6920 Read_relocs_data* rd)
6921 {
6922 // First, call base class method to process relocations in this object.
6923 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6924
6925 // If --gc-sections is not specified, there is nothing more to do.
6926 // This happens when --icf is used but --gc-sections is not.
6927 if (!parameters->options().gc_sections())
6928 return;
6929
6930 unsigned int shnum = this->shnum();
6931 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6932 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6933 shnum * shdr_size,
6934 true, true);
6935
6936 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6937 // to these from the linked text sections.
6938 const unsigned char* ps = pshdrs + shdr_size;
6939 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6940 {
6941 elfcpp::Shdr<32, big_endian> shdr(ps);
6942 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6943 {
6944 // Found an .ARM.exidx section, add it to the set of reachable
6945 // sections from its linked text section.
6946 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6947 symtab->gc()->add_reference(this, text_shndx, this, i);
6948 }
6949 }
6950 }
6951
6952 // Update output local symbol count. Owing to EXIDX entry merging, some local
6953 // symbols will be removed in output. Adjust output local symbol count
6954 // accordingly. We can only changed the static output local symbol count. It
6955 // is too late to change the dynamic symbols.
6956
6957 template<bool big_endian>
6958 void
6959 Arm_relobj<big_endian>::update_output_local_symbol_count()
6960 {
6961 // Caller should check that this needs updating. We want caller checking
6962 // because output_local_symbol_count_needs_update() is most likely inlined.
6963 gold_assert(this->output_local_symbol_count_needs_update_);
6964
6965 gold_assert(this->symtab_shndx() != -1U);
6966 if (this->symtab_shndx() == 0)
6967 {
6968 // This object has no symbols. Weird but legal.
6969 return;
6970 }
6971
6972 // Read the symbol table section header.
6973 const unsigned int symtab_shndx = this->symtab_shndx();
6974 elfcpp::Shdr<32, big_endian>
6975 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6976 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6977
6978 // Read the local symbols.
6979 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6980 const unsigned int loccount = this->local_symbol_count();
6981 gold_assert(loccount == symtabshdr.get_sh_info());
6982 off_t locsize = loccount * sym_size;
6983 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6984 locsize, true, true);
6985
6986 // Loop over the local symbols.
6987
6988 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6989 Output_sections;
6990 const Output_sections& out_sections(this->output_sections());
6991 unsigned int shnum = this->shnum();
6992 unsigned int count = 0;
6993 // Skip the first, dummy, symbol.
6994 psyms += sym_size;
6995 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6996 {
6997 elfcpp::Sym<32, big_endian> sym(psyms);
6998
6999 Symbol_value<32>& lv((*this->local_values())[i]);
7000
7001 // This local symbol was already discarded by do_count_local_symbols.
7002 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
7003 continue;
7004
7005 bool is_ordinary;
7006 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
7007 &is_ordinary);
7008
7009 if (shndx < shnum)
7010 {
7011 Output_section* os = out_sections[shndx];
7012
7013 // This local symbol no longer has an output section. Discard it.
7014 if (os == NULL)
7015 {
7016 lv.set_no_output_symtab_entry();
7017 continue;
7018 }
7019
7020 // Currently we only discard parts of EXIDX input sections.
7021 // We explicitly check for a merged EXIDX input section to avoid
7022 // calling Output_section_data::output_offset unless necessary.
7023 if ((this->get_output_section_offset(shndx) == invalid_address)
7024 && (this->exidx_input_section_by_shndx(shndx) != NULL))
7025 {
7026 section_offset_type output_offset =
7027 os->output_offset(this, shndx, lv.input_value());
7028 if (output_offset == -1)
7029 {
7030 // This symbol is defined in a part of an EXIDX input section
7031 // that is discarded due to entry merging.
7032 lv.set_no_output_symtab_entry();
7033 continue;
7034 }
7035 }
7036 }
7037
7038 ++count;
7039 }
7040
7041 this->set_output_local_symbol_count(count);
7042 this->output_local_symbol_count_needs_update_ = false;
7043 }
7044
7045 // Arm_dynobj methods.
7046
7047 // Read the symbol information.
7048
7049 template<bool big_endian>
7050 void
7051 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
7052 {
7053 // Call parent class to read symbol information.
7054 this->base_read_symbols(sd);
7055
7056 // Read processor-specific flags in ELF file header.
7057 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
7058 elfcpp::Elf_sizes<32>::ehdr_size,
7059 true, false);
7060 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
7061 this->processor_specific_flags_ = ehdr.get_e_flags();
7062
7063 // Read the attributes section if there is one.
7064 // We read from the end because gas seems to put it near the end of
7065 // the section headers.
7066 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
7067 const unsigned char* ps =
7068 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
7069 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
7070 {
7071 elfcpp::Shdr<32, big_endian> shdr(ps);
7072 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
7073 {
7074 section_offset_type section_offset = shdr.get_sh_offset();
7075 section_size_type section_size =
7076 convert_to_section_size_type(shdr.get_sh_size());
7077 const unsigned char* view =
7078 this->get_view(section_offset, section_size, true, false);
7079 this->attributes_section_data_ =
7080 new Attributes_section_data(view, section_size);
7081 break;
7082 }
7083 }
7084 }
7085
7086 // Stub_addend_reader methods.
7087
7088 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7089
7090 template<bool big_endian>
7091 elfcpp::Elf_types<32>::Elf_Swxword
7092 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7093 unsigned int r_type,
7094 const unsigned char* view,
7095 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7096 {
7097 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7098
7099 switch (r_type)
7100 {
7101 case elfcpp::R_ARM_CALL:
7102 case elfcpp::R_ARM_JUMP24:
7103 case elfcpp::R_ARM_PLT32:
7104 {
7105 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7106 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7107 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7108 return Bits<26>::sign_extend32(val << 2);
7109 }
7110
7111 case elfcpp::R_ARM_THM_CALL:
7112 case elfcpp::R_ARM_THM_JUMP24:
7113 case elfcpp::R_ARM_THM_XPC22:
7114 {
7115 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7116 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7117 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7118 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7119 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7120 }
7121
7122 case elfcpp::R_ARM_THM_JUMP19:
7123 {
7124 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7125 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7126 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7127 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7128 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7129 }
7130
7131 default:
7132 gold_unreachable();
7133 }
7134 }
7135
7136 // Arm_output_data_got methods.
7137
7138 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7139 // The first one is initialized to be 1, which is the module index for
7140 // the main executable and the second one 0. A reloc of the type
7141 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7142 // be applied by gold. GSYM is a global symbol.
7143 //
7144 template<bool big_endian>
7145 void
7146 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7147 unsigned int got_type,
7148 Symbol* gsym)
7149 {
7150 if (gsym->has_got_offset(got_type))
7151 return;
7152
7153 // We are doing a static link. Just mark it as belong to module 1,
7154 // the executable.
7155 unsigned int got_offset = this->add_constant(1);
7156 gsym->set_got_offset(got_type, got_offset);
7157 got_offset = this->add_constant(0);
7158 this->static_relocs_.push_back(Static_reloc(got_offset,
7159 elfcpp::R_ARM_TLS_DTPOFF32,
7160 gsym));
7161 }
7162
7163 // Same as the above but for a local symbol.
7164
7165 template<bool big_endian>
7166 void
7167 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7168 unsigned int got_type,
7169 Sized_relobj_file<32, big_endian>* object,
7170 unsigned int index)
7171 {
7172 if (object->local_has_got_offset(index, got_type))
7173 return;
7174
7175 // We are doing a static link. Just mark it as belong to module 1,
7176 // the executable.
7177 unsigned int got_offset = this->add_constant(1);
7178 object->set_local_got_offset(index, got_type, got_offset);
7179 got_offset = this->add_constant(0);
7180 this->static_relocs_.push_back(Static_reloc(got_offset,
7181 elfcpp::R_ARM_TLS_DTPOFF32,
7182 object, index));
7183 }
7184
7185 template<bool big_endian>
7186 void
7187 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7188 {
7189 // Call parent to write out GOT.
7190 Output_data_got<32, big_endian>::do_write(of);
7191
7192 // We are done if there is no fix up.
7193 if (this->static_relocs_.empty())
7194 return;
7195
7196 gold_assert(parameters->doing_static_link());
7197
7198 const off_t offset = this->offset();
7199 const section_size_type oview_size =
7200 convert_to_section_size_type(this->data_size());
7201 unsigned char* const oview = of->get_output_view(offset, oview_size);
7202
7203 Output_segment* tls_segment = this->layout_->tls_segment();
7204 gold_assert(tls_segment != NULL);
7205
7206 // The thread pointer $tp points to the TCB, which is followed by the
7207 // TLS. So we need to adjust $tp relative addressing by this amount.
7208 Arm_address aligned_tcb_size =
7209 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7210
7211 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7212 {
7213 Static_reloc& reloc(this->static_relocs_[i]);
7214
7215 Arm_address value;
7216 if (!reloc.symbol_is_global())
7217 {
7218 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7219 const Symbol_value<32>* psymval =
7220 reloc.relobj()->local_symbol(reloc.index());
7221
7222 // We are doing static linking. Issue an error and skip this
7223 // relocation if the symbol is undefined or in a discarded_section.
7224 bool is_ordinary;
7225 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7226 if ((shndx == elfcpp::SHN_UNDEF)
7227 || (is_ordinary
7228 && shndx != elfcpp::SHN_UNDEF
7229 && !object->is_section_included(shndx)
7230 && !this->symbol_table_->is_section_folded(object, shndx)))
7231 {
7232 gold_error(_("undefined or discarded local symbol %u from "
7233 " object %s in GOT"),
7234 reloc.index(), reloc.relobj()->name().c_str());
7235 continue;
7236 }
7237
7238 value = psymval->value(object, 0);
7239 }
7240 else
7241 {
7242 const Symbol* gsym = reloc.symbol();
7243 gold_assert(gsym != NULL);
7244 if (gsym->is_forwarder())
7245 gsym = this->symbol_table_->resolve_forwards(gsym);
7246
7247 // We are doing static linking. Issue an error and skip this
7248 // relocation if the symbol is undefined or in a discarded_section
7249 // unless it is a weakly_undefined symbol.
7250 if ((gsym->is_defined_in_discarded_section()
7251 || gsym->is_undefined())
7252 && !gsym->is_weak_undefined())
7253 {
7254 gold_error(_("undefined or discarded symbol %s in GOT"),
7255 gsym->name());
7256 continue;
7257 }
7258
7259 if (!gsym->is_weak_undefined())
7260 {
7261 const Sized_symbol<32>* sym =
7262 static_cast<const Sized_symbol<32>*>(gsym);
7263 value = sym->value();
7264 }
7265 else
7266 value = 0;
7267 }
7268
7269 unsigned got_offset = reloc.got_offset();
7270 gold_assert(got_offset < oview_size);
7271
7272 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7273 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7274 Valtype x;
7275 switch (reloc.r_type())
7276 {
7277 case elfcpp::R_ARM_TLS_DTPOFF32:
7278 x = value;
7279 break;
7280 case elfcpp::R_ARM_TLS_TPOFF32:
7281 x = value + aligned_tcb_size;
7282 break;
7283 default:
7284 gold_unreachable();
7285 }
7286 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7287 }
7288
7289 of->write_output_view(offset, oview_size, oview);
7290 }
7291
7292 // A class to handle the PLT data.
7293 // This is an abstract base class that handles most of the linker details
7294 // but does not know the actual contents of PLT entries. The derived
7295 // classes below fill in those details.
7296
7297 template<bool big_endian>
7298 class Output_data_plt_arm : public Output_section_data
7299 {
7300 public:
7301 // Unlike aarch64, which records symbol value in "addend" field of relocations
7302 // and could be done at the same time an IRelative reloc is created for the
7303 // symbol, arm puts the symbol value into "GOT" table, which, however, is
7304 // issued later in Output_data_plt_arm::do_write(). So we have a struct here
7305 // to keep necessary symbol information for later use in do_write. We usually
7306 // have only a very limited number of ifuncs, so the extra data required here
7307 // is also limited.
7308
7309 struct IRelative_data
7310 {
7311 IRelative_data(Sized_symbol<32>* sized_symbol)
7312 : symbol_is_global_(true)
7313 {
7314 u_.global = sized_symbol;
7315 }
7316
7317 IRelative_data(Sized_relobj_file<32, big_endian>* relobj,
7318 unsigned int index)
7319 : symbol_is_global_(false)
7320 {
7321 u_.local.relobj = relobj;
7322 u_.local.index = index;
7323 }
7324
7325 union
7326 {
7327 Sized_symbol<32>* global;
7328
7329 struct
7330 {
7331 Sized_relobj_file<32, big_endian>* relobj;
7332 unsigned int index;
7333 } local;
7334 } u_;
7335
7336 bool symbol_is_global_;
7337 };
7338
7339 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7340 Reloc_section;
7341
7342 Output_data_plt_arm(Layout* layout, uint64_t addralign,
7343 Arm_output_data_got<big_endian>* got,
7344 Output_data_space* got_plt,
7345 Output_data_space* got_irelative);
7346
7347 // Add an entry to the PLT.
7348 void
7349 add_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym);
7350
7351 // Add the relocation for a plt entry.
7352 void
7353 add_relocation(Symbol_table* symtab, Layout* layout,
7354 Symbol* gsym, unsigned int got_offset);
7355
7356 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
7357 unsigned int
7358 add_local_ifunc_entry(Symbol_table* symtab, Layout*,
7359 Sized_relobj_file<32, big_endian>* relobj,
7360 unsigned int local_sym_index);
7361
7362 // Return the .rel.plt section data.
7363 const Reloc_section*
7364 rel_plt() const
7365 { return this->rel_; }
7366
7367 // Return the PLT relocation container for IRELATIVE.
7368 Reloc_section*
7369 rel_irelative(Symbol_table*, Layout*);
7370
7371 // Return the number of PLT entries.
7372 unsigned int
7373 entry_count() const
7374 { return this->count_ + this->irelative_count_; }
7375
7376 // Return the offset of the first non-reserved PLT entry.
7377 unsigned int
7378 first_plt_entry_offset() const
7379 { return this->do_first_plt_entry_offset(); }
7380
7381 // Return the size of a PLT entry.
7382 unsigned int
7383 get_plt_entry_size() const
7384 { return this->do_get_plt_entry_size(); }
7385
7386 // Return the PLT address for globals.
7387 uint32_t
7388 address_for_global(const Symbol*) const;
7389
7390 // Return the PLT address for locals.
7391 uint32_t
7392 address_for_local(const Relobj*, unsigned int symndx) const;
7393
7394 protected:
7395 // Fill in the first PLT entry.
7396 void
7397 fill_first_plt_entry(unsigned char* pov,
7398 Arm_address got_address,
7399 Arm_address plt_address)
7400 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7401
7402 void
7403 fill_plt_entry(unsigned char* pov,
7404 Arm_address got_address,
7405 Arm_address plt_address,
7406 unsigned int got_offset,
7407 unsigned int plt_offset)
7408 { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7409
7410 virtual unsigned int
7411 do_first_plt_entry_offset() const = 0;
7412
7413 virtual unsigned int
7414 do_get_plt_entry_size() const = 0;
7415
7416 virtual void
7417 do_fill_first_plt_entry(unsigned char* pov,
7418 Arm_address got_address,
7419 Arm_address plt_address) = 0;
7420
7421 virtual void
7422 do_fill_plt_entry(unsigned char* pov,
7423 Arm_address got_address,
7424 Arm_address plt_address,
7425 unsigned int got_offset,
7426 unsigned int plt_offset) = 0;
7427
7428 void
7429 do_adjust_output_section(Output_section* os);
7430
7431 // Write to a map file.
7432 void
7433 do_print_to_mapfile(Mapfile* mapfile) const
7434 { mapfile->print_output_data(this, _("** PLT")); }
7435
7436 private:
7437 // Set the final size.
7438 void
7439 set_final_data_size()
7440 {
7441 this->set_data_size(this->first_plt_entry_offset()
7442 + ((this->count_ + this->irelative_count_)
7443 * this->get_plt_entry_size()));
7444 }
7445
7446 // Write out the PLT data.
7447 void
7448 do_write(Output_file*);
7449
7450 // Record irelative symbol data.
7451 void insert_irelative_data(const IRelative_data& idata)
7452 { irelative_data_vec_.push_back(idata); }
7453
7454 // The reloc section.
7455 Reloc_section* rel_;
7456 // The IRELATIVE relocs, if necessary. These must follow the
7457 // regular PLT relocations.
7458 Reloc_section* irelative_rel_;
7459 // The .got section.
7460 Arm_output_data_got<big_endian>* got_;
7461 // The .got.plt section.
7462 Output_data_space* got_plt_;
7463 // The part of the .got.plt section used for IRELATIVE relocs.
7464 Output_data_space* got_irelative_;
7465 // The number of PLT entries.
7466 unsigned int count_;
7467 // Number of PLT entries with R_ARM_IRELATIVE relocs. These
7468 // follow the regular PLT entries.
7469 unsigned int irelative_count_;
7470 // Vector for irelative data.
7471 typedef std::vector<IRelative_data> IRelative_data_vec;
7472 IRelative_data_vec irelative_data_vec_;
7473 };
7474
7475 // Create the PLT section. The ordinary .got section is an argument,
7476 // since we need to refer to the start. We also create our own .got
7477 // section just for PLT entries.
7478
7479 template<bool big_endian>
7480 Output_data_plt_arm<big_endian>::Output_data_plt_arm(
7481 Layout* layout, uint64_t addralign,
7482 Arm_output_data_got<big_endian>* got,
7483 Output_data_space* got_plt,
7484 Output_data_space* got_irelative)
7485 : Output_section_data(addralign), irelative_rel_(NULL),
7486 got_(got), got_plt_(got_plt), got_irelative_(got_irelative),
7487 count_(0), irelative_count_(0)
7488 {
7489 this->rel_ = new Reloc_section(false);
7490 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7491 elfcpp::SHF_ALLOC, this->rel_,
7492 ORDER_DYNAMIC_PLT_RELOCS, false);
7493 }
7494
7495 template<bool big_endian>
7496 void
7497 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7498 {
7499 os->set_entsize(0);
7500 }
7501
7502 // Add an entry to the PLT.
7503
7504 template<bool big_endian>
7505 void
7506 Output_data_plt_arm<big_endian>::add_entry(Symbol_table* symtab,
7507 Layout* layout,
7508 Symbol* gsym)
7509 {
7510 gold_assert(!gsym->has_plt_offset());
7511
7512 unsigned int* entry_count;
7513 Output_section_data_build* got;
7514
7515 // We have 2 different types of plt entry here, normal and ifunc.
7516
7517 // For normal plt, the offset begins with first_plt_entry_offset(20), and the
7518 // 1st entry offset would be 20, the second 32, third 44 ... etc.
7519
7520 // For ifunc plt, the offset begins with 0. So the first offset would 0,
7521 // second 12, third 24 ... etc.
7522
7523 // IFunc plt entries *always* come after *normal* plt entries.
7524
7525 // Notice, when computing the plt address of a certain symbol, "plt_address +
7526 // plt_offset" is no longer correct. Use target->plt_address_for_global() or
7527 // target->plt_address_for_local() instead.
7528
7529 int begin_offset = 0;
7530 if (gsym->type() == elfcpp::STT_GNU_IFUNC
7531 && gsym->can_use_relative_reloc(false))
7532 {
7533 entry_count = &this->irelative_count_;
7534 got = this->got_irelative_;
7535 // For irelative plt entries, offset is relative to the end of normal plt
7536 // entries, so it starts from 0.
7537 begin_offset = 0;
7538 // Record symbol information.
7539 this->insert_irelative_data(
7540 IRelative_data(symtab->get_sized_symbol<32>(gsym)));
7541 }
7542 else
7543 {
7544 entry_count = &this->count_;
7545 got = this->got_plt_;
7546 // Note that for normal plt entries, when setting the PLT offset we skip
7547 // the initial reserved PLT entry.
7548 begin_offset = this->first_plt_entry_offset();
7549 }
7550
7551 gsym->set_plt_offset(begin_offset
7552 + (*entry_count) * this->get_plt_entry_size());
7553
7554 ++(*entry_count);
7555
7556 section_offset_type got_offset = got->current_data_size();
7557
7558 // Every PLT entry needs a GOT entry which points back to the PLT
7559 // entry (this will be changed by the dynamic linker, normally
7560 // lazily when the function is called).
7561 got->set_current_data_size(got_offset + 4);
7562
7563 // Every PLT entry needs a reloc.
7564 this->add_relocation(symtab, layout, gsym, got_offset);
7565
7566 // Note that we don't need to save the symbol. The contents of the
7567 // PLT are independent of which symbols are used. The symbols only
7568 // appear in the relocations.
7569 }
7570
7571 // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
7572 // the PLT offset.
7573
7574 template<bool big_endian>
7575 unsigned int
7576 Output_data_plt_arm<big_endian>::add_local_ifunc_entry(
7577 Symbol_table* symtab,
7578 Layout* layout,
7579 Sized_relobj_file<32, big_endian>* relobj,
7580 unsigned int local_sym_index)
7581 {
7582 this->insert_irelative_data(IRelative_data(relobj, local_sym_index));
7583
7584 // Notice, when computingthe plt entry address, "plt_address + plt_offset" is
7585 // no longer correct. Use target->plt_address_for_local() instead.
7586 unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size();
7587 ++this->irelative_count_;
7588
7589 section_offset_type got_offset = this->got_irelative_->current_data_size();
7590
7591 // Every PLT entry needs a GOT entry which points back to the PLT
7592 // entry.
7593 this->got_irelative_->set_current_data_size(got_offset + 4);
7594
7595
7596 // Every PLT entry needs a reloc.
7597 Reloc_section* rel = this->rel_irelative(symtab, layout);
7598 rel->add_symbolless_local_addend(relobj, local_sym_index,
7599 elfcpp::R_ARM_IRELATIVE,
7600 this->got_irelative_, got_offset);
7601 return plt_offset;
7602 }
7603
7604
7605 // Add the relocation for a PLT entry.
7606
7607 template<bool big_endian>
7608 void
7609 Output_data_plt_arm<big_endian>::add_relocation(
7610 Symbol_table* symtab, Layout* layout, Symbol* gsym, unsigned int got_offset)
7611 {
7612 if (gsym->type() == elfcpp::STT_GNU_IFUNC
7613 && gsym->can_use_relative_reloc(false))
7614 {
7615 Reloc_section* rel = this->rel_irelative(symtab, layout);
7616 rel->add_symbolless_global_addend(gsym, elfcpp::R_ARM_IRELATIVE,
7617 this->got_irelative_, got_offset);
7618 }
7619 else
7620 {
7621 gsym->set_needs_dynsym_entry();
7622 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7623 got_offset);
7624 }
7625 }
7626
7627
7628 // Create the irelative relocation data.
7629
7630 template<bool big_endian>
7631 typename Output_data_plt_arm<big_endian>::Reloc_section*
7632 Output_data_plt_arm<big_endian>::rel_irelative(Symbol_table* symtab,
7633 Layout* layout)
7634 {
7635 if (this->irelative_rel_ == NULL)
7636 {
7637 // Since irelative relocations goes into 'rel.dyn', we delegate the
7638 // creation of irelative_rel_ to where rel_dyn section gets created.
7639 Target_arm<big_endian>* arm_target =
7640 Target_arm<big_endian>::default_target();
7641 this->irelative_rel_ = arm_target->rel_irelative_section(layout);
7642
7643 // Make sure we have a place for the TLSDESC relocations, in
7644 // case we see any later on.
7645 // this->rel_tlsdesc(layout);
7646 if (parameters->doing_static_link())
7647 {
7648 // A statically linked executable will only have a .rel.plt section to
7649 // hold R_ARM_IRELATIVE relocs for STT_GNU_IFUNC symbols. The library
7650 // will use these symbols to locate the IRELATIVE relocs at program
7651 // startup time.
7652 symtab->define_in_output_data("__rel_iplt_start", NULL,
7653 Symbol_table::PREDEFINED,
7654 this->irelative_rel_, 0, 0,
7655 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7656 elfcpp::STV_HIDDEN, 0, false, true);
7657 symtab->define_in_output_data("__rel_iplt_end", NULL,
7658 Symbol_table::PREDEFINED,
7659 this->irelative_rel_, 0, 0,
7660 elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
7661 elfcpp::STV_HIDDEN, 0, true, true);
7662 }
7663 }
7664 return this->irelative_rel_;
7665 }
7666
7667
7668 // Return the PLT address for a global symbol.
7669
7670 template<bool big_endian>
7671 uint32_t
7672 Output_data_plt_arm<big_endian>::address_for_global(const Symbol* gsym) const
7673 {
7674 uint64_t begin_offset = 0;
7675 if (gsym->type() == elfcpp::STT_GNU_IFUNC
7676 && gsym->can_use_relative_reloc(false))
7677 {
7678 begin_offset = (this->first_plt_entry_offset() +
7679 this->count_ * this->get_plt_entry_size());
7680 }
7681 return this->address() + begin_offset + gsym->plt_offset();
7682 }
7683
7684
7685 // Return the PLT address for a local symbol. These are always
7686 // IRELATIVE relocs.
7687
7688 template<bool big_endian>
7689 uint32_t
7690 Output_data_plt_arm<big_endian>::address_for_local(
7691 const Relobj* object,
7692 unsigned int r_sym) const
7693 {
7694 return (this->address()
7695 + this->first_plt_entry_offset()
7696 + this->count_ * this->get_plt_entry_size()
7697 + object->local_plt_offset(r_sym));
7698 }
7699
7700
7701 template<bool big_endian>
7702 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7703 {
7704 public:
7705 Output_data_plt_arm_standard(Layout* layout,
7706 Arm_output_data_got<big_endian>* got,
7707 Output_data_space* got_plt,
7708 Output_data_space* got_irelative)
7709 : Output_data_plt_arm<big_endian>(layout, 4, got, got_plt, got_irelative)
7710 { }
7711
7712 protected:
7713 // Return the offset of the first non-reserved PLT entry.
7714 virtual unsigned int
7715 do_first_plt_entry_offset() const
7716 { return sizeof(first_plt_entry); }
7717
7718 // Return the size of a PLT entry.
7719 virtual unsigned int
7720 do_get_plt_entry_size() const
7721 { return sizeof(plt_entry); }
7722
7723 virtual void
7724 do_fill_first_plt_entry(unsigned char* pov,
7725 Arm_address got_address,
7726 Arm_address plt_address);
7727
7728 virtual void
7729 do_fill_plt_entry(unsigned char* pov,
7730 Arm_address got_address,
7731 Arm_address plt_address,
7732 unsigned int got_offset,
7733 unsigned int plt_offset);
7734
7735 private:
7736 // Template for the first PLT entry.
7737 static const uint32_t first_plt_entry[5];
7738
7739 // Template for subsequent PLT entries.
7740 static const uint32_t plt_entry[3];
7741 };
7742
7743 // ARM PLTs.
7744 // FIXME: This is not very flexible. Right now this has only been tested
7745 // on armv5te. If we are to support additional architecture features like
7746 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7747
7748 // The first entry in the PLT.
7749 template<bool big_endian>
7750 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7751 {
7752 0xe52de004, // str lr, [sp, #-4]!
7753 0xe59fe004, // ldr lr, [pc, #4]
7754 0xe08fe00e, // add lr, pc, lr
7755 0xe5bef008, // ldr pc, [lr, #8]!
7756 0x00000000, // &GOT[0] - .
7757 };
7758
7759 template<bool big_endian>
7760 void
7761 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7762 unsigned char* pov,
7763 Arm_address got_address,
7764 Arm_address plt_address)
7765 {
7766 // Write first PLT entry. All but the last word are constants.
7767 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7768 / sizeof(plt_entry[0]));
7769 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7770 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7771 // Last word in first PLT entry is &GOT[0] - .
7772 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7773 got_address - (plt_address + 16));
7774 }
7775
7776 // Subsequent entries in the PLT.
7777
7778 template<bool big_endian>
7779 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7780 {
7781 0xe28fc600, // add ip, pc, #0xNN00000
7782 0xe28cca00, // add ip, ip, #0xNN000
7783 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7784 };
7785
7786 template<bool big_endian>
7787 void
7788 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7789 unsigned char* pov,
7790 Arm_address got_address,
7791 Arm_address plt_address,
7792 unsigned int got_offset,
7793 unsigned int plt_offset)
7794 {
7795 int32_t offset = ((got_address + got_offset)
7796 - (plt_address + plt_offset + 8));
7797
7798 gold_assert(offset >= 0 && offset < 0x0fffffff);
7799 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7800 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7801 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7802 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7803 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7804 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7805 }
7806
7807 // Write out the PLT. This uses the hand-coded instructions above,
7808 // and adjusts them as needed. This is all specified by the arm ELF
7809 // Processor Supplement.
7810
7811 template<bool big_endian>
7812 void
7813 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7814 {
7815 const off_t offset = this->offset();
7816 const section_size_type oview_size =
7817 convert_to_section_size_type(this->data_size());
7818 unsigned char* const oview = of->get_output_view(offset, oview_size);
7819
7820 const off_t got_file_offset = this->got_plt_->offset();
7821 gold_assert(got_file_offset + this->got_plt_->data_size()
7822 == this->got_irelative_->offset());
7823 const section_size_type got_size =
7824 convert_to_section_size_type(this->got_plt_->data_size()
7825 + this->got_irelative_->data_size());
7826 unsigned char* const got_view = of->get_output_view(got_file_offset,
7827 got_size);
7828 unsigned char* pov = oview;
7829
7830 Arm_address plt_address = this->address();
7831 Arm_address got_address = this->got_plt_->address();
7832
7833 // Write first PLT entry.
7834 this->fill_first_plt_entry(pov, got_address, plt_address);
7835 pov += this->first_plt_entry_offset();
7836
7837 unsigned char* got_pov = got_view;
7838
7839 memset(got_pov, 0, 12);
7840 got_pov += 12;
7841
7842 unsigned int plt_offset = this->first_plt_entry_offset();
7843 unsigned int got_offset = 12;
7844 const unsigned int count = this->count_ + this->irelative_count_;
7845 gold_assert(this->irelative_count_ == this->irelative_data_vec_.size());
7846 for (unsigned int i = 0;
7847 i < count;
7848 ++i,
7849 pov += this->get_plt_entry_size(),
7850 got_pov += 4,
7851 plt_offset += this->get_plt_entry_size(),
7852 got_offset += 4)
7853 {
7854 // Set and adjust the PLT entry itself.
7855 this->fill_plt_entry(pov, got_address, plt_address,
7856 got_offset, plt_offset);
7857
7858 Arm_address value;
7859 if (i < this->count_)
7860 {
7861 // For non-irelative got entries, the value is the beginning of plt.
7862 value = plt_address;
7863 }
7864 else
7865 {
7866 // For irelative got entries, the value is the (global/local) symbol
7867 // address.
7868 const IRelative_data& idata =
7869 this->irelative_data_vec_[i - this->count_];
7870 if (idata.symbol_is_global_)
7871 {
7872 // Set the entry in the GOT for irelative symbols. The content is
7873 // the address of the ifunc, not the address of plt start.
7874 const Sized_symbol<32>* sized_symbol = idata.u_.global;
7875 gold_assert(sized_symbol->type() == elfcpp::STT_GNU_IFUNC);
7876 value = sized_symbol->value();
7877 }
7878 else
7879 {
7880 value = idata.u_.local.relobj->local_symbol_value(
7881 idata.u_.local.index, 0);
7882 }
7883 }
7884 elfcpp::Swap<32, big_endian>::writeval(got_pov, value);
7885 }
7886
7887 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7888 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7889
7890 of->write_output_view(offset, oview_size, oview);
7891 of->write_output_view(got_file_offset, got_size, got_view);
7892 }
7893
7894
7895 // Create a PLT entry for a global symbol.
7896
7897 template<bool big_endian>
7898 void
7899 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7900 Symbol* gsym)
7901 {
7902 if (gsym->has_plt_offset())
7903 return;
7904
7905 if (this->plt_ == NULL)
7906 this->make_plt_section(symtab, layout);
7907
7908 this->plt_->add_entry(symtab, layout, gsym);
7909 }
7910
7911
7912 // Create the PLT section.
7913 template<bool big_endian>
7914 void
7915 Target_arm<big_endian>::make_plt_section(
7916 Symbol_table* symtab, Layout* layout)
7917 {
7918 if (this->plt_ == NULL)
7919 {
7920 // Create the GOT section first.
7921 this->got_section(symtab, layout);
7922
7923 // GOT for irelatives is create along with got.plt.
7924 gold_assert(this->got_ != NULL
7925 && this->got_plt_ != NULL
7926 && this->got_irelative_ != NULL);
7927 this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_,
7928 this->got_irelative_);
7929
7930 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7931 (elfcpp::SHF_ALLOC
7932 | elfcpp::SHF_EXECINSTR),
7933 this->plt_, ORDER_PLT, false);
7934 symtab->define_in_output_data("$a", NULL,
7935 Symbol_table::PREDEFINED,
7936 this->plt_,
7937 0, 0, elfcpp::STT_NOTYPE,
7938 elfcpp::STB_LOCAL,
7939 elfcpp::STV_DEFAULT, 0,
7940 false, false);
7941 }
7942 }
7943
7944
7945 // Make a PLT entry for a local STT_GNU_IFUNC symbol.
7946
7947 template<bool big_endian>
7948 void
7949 Target_arm<big_endian>::make_local_ifunc_plt_entry(
7950 Symbol_table* symtab, Layout* layout,
7951 Sized_relobj_file<32, big_endian>* relobj,
7952 unsigned int local_sym_index)
7953 {
7954 if (relobj->local_has_plt_offset(local_sym_index))
7955 return;
7956 if (this->plt_ == NULL)
7957 this->make_plt_section(symtab, layout);
7958 unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
7959 relobj,
7960 local_sym_index);
7961 relobj->set_local_plt_offset(local_sym_index, plt_offset);
7962 }
7963
7964
7965 // Return the number of entries in the PLT.
7966
7967 template<bool big_endian>
7968 unsigned int
7969 Target_arm<big_endian>::plt_entry_count() const
7970 {
7971 if (this->plt_ == NULL)
7972 return 0;
7973 return this->plt_->entry_count();
7974 }
7975
7976 // Return the offset of the first non-reserved PLT entry.
7977
7978 template<bool big_endian>
7979 unsigned int
7980 Target_arm<big_endian>::first_plt_entry_offset() const
7981 {
7982 return this->plt_->first_plt_entry_offset();
7983 }
7984
7985 // Return the size of each PLT entry.
7986
7987 template<bool big_endian>
7988 unsigned int
7989 Target_arm<big_endian>::plt_entry_size() const
7990 {
7991 return this->plt_->get_plt_entry_size();
7992 }
7993
7994 // Get the section to use for TLS_DESC relocations.
7995
7996 template<bool big_endian>
7997 typename Target_arm<big_endian>::Reloc_section*
7998 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7999 {
8000 return this->plt_section()->rel_tls_desc(layout);
8001 }
8002
8003 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
8004
8005 template<bool big_endian>
8006 void
8007 Target_arm<big_endian>::define_tls_base_symbol(
8008 Symbol_table* symtab,
8009 Layout* layout)
8010 {
8011 if (this->tls_base_symbol_defined_)
8012 return;
8013
8014 Output_segment* tls_segment = layout->tls_segment();
8015 if (tls_segment != NULL)
8016 {
8017 bool is_exec = parameters->options().output_is_executable();
8018 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
8019 Symbol_table::PREDEFINED,
8020 tls_segment, 0, 0,
8021 elfcpp::STT_TLS,
8022 elfcpp::STB_LOCAL,
8023 elfcpp::STV_HIDDEN, 0,
8024 (is_exec
8025 ? Symbol::SEGMENT_END
8026 : Symbol::SEGMENT_START),
8027 true);
8028 }
8029 this->tls_base_symbol_defined_ = true;
8030 }
8031
8032 // Create a GOT entry for the TLS module index.
8033
8034 template<bool big_endian>
8035 unsigned int
8036 Target_arm<big_endian>::got_mod_index_entry(
8037 Symbol_table* symtab,
8038 Layout* layout,
8039 Sized_relobj_file<32, big_endian>* object)
8040 {
8041 if (this->got_mod_index_offset_ == -1U)
8042 {
8043 gold_assert(symtab != NULL && layout != NULL && object != NULL);
8044 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
8045 unsigned int got_offset;
8046 if (!parameters->doing_static_link())
8047 {
8048 got_offset = got->add_constant(0);
8049 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
8050 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
8051 got_offset);
8052 }
8053 else
8054 {
8055 // We are doing a static link. Just mark it as belong to module 1,
8056 // the executable.
8057 got_offset = got->add_constant(1);
8058 }
8059
8060 got->add_constant(0);
8061 this->got_mod_index_offset_ = got_offset;
8062 }
8063 return this->got_mod_index_offset_;
8064 }
8065
8066 // Optimize the TLS relocation type based on what we know about the
8067 // symbol. IS_FINAL is true if the final address of this symbol is
8068 // known at link time.
8069
8070 template<bool big_endian>
8071 tls::Tls_optimization
8072 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
8073 {
8074 // FIXME: Currently we do not do any TLS optimization.
8075 return tls::TLSOPT_NONE;
8076 }
8077
8078 // Get the Reference_flags for a particular relocation.
8079
8080 template<bool big_endian>
8081 int
8082 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
8083 {
8084 switch (r_type)
8085 {
8086 case elfcpp::R_ARM_NONE:
8087 case elfcpp::R_ARM_V4BX:
8088 case elfcpp::R_ARM_GNU_VTENTRY:
8089 case elfcpp::R_ARM_GNU_VTINHERIT:
8090 // No symbol reference.
8091 return 0;
8092
8093 case elfcpp::R_ARM_ABS32:
8094 case elfcpp::R_ARM_ABS16:
8095 case elfcpp::R_ARM_ABS12:
8096 case elfcpp::R_ARM_THM_ABS5:
8097 case elfcpp::R_ARM_ABS8:
8098 case elfcpp::R_ARM_BASE_ABS:
8099 case elfcpp::R_ARM_MOVW_ABS_NC:
8100 case elfcpp::R_ARM_MOVT_ABS:
8101 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8102 case elfcpp::R_ARM_THM_MOVT_ABS:
8103 case elfcpp::R_ARM_ABS32_NOI:
8104 return Symbol::ABSOLUTE_REF;
8105
8106 case elfcpp::R_ARM_REL32:
8107 case elfcpp::R_ARM_LDR_PC_G0:
8108 case elfcpp::R_ARM_SBREL32:
8109 case elfcpp::R_ARM_THM_PC8:
8110 case elfcpp::R_ARM_BASE_PREL:
8111 case elfcpp::R_ARM_MOVW_PREL_NC:
8112 case elfcpp::R_ARM_MOVT_PREL:
8113 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8114 case elfcpp::R_ARM_THM_MOVT_PREL:
8115 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8116 case elfcpp::R_ARM_THM_PC12:
8117 case elfcpp::R_ARM_REL32_NOI:
8118 case elfcpp::R_ARM_ALU_PC_G0_NC:
8119 case elfcpp::R_ARM_ALU_PC_G0:
8120 case elfcpp::R_ARM_ALU_PC_G1_NC:
8121 case elfcpp::R_ARM_ALU_PC_G1:
8122 case elfcpp::R_ARM_ALU_PC_G2:
8123 case elfcpp::R_ARM_LDR_PC_G1:
8124 case elfcpp::R_ARM_LDR_PC_G2:
8125 case elfcpp::R_ARM_LDRS_PC_G0:
8126 case elfcpp::R_ARM_LDRS_PC_G1:
8127 case elfcpp::R_ARM_LDRS_PC_G2:
8128 case elfcpp::R_ARM_LDC_PC_G0:
8129 case elfcpp::R_ARM_LDC_PC_G1:
8130 case elfcpp::R_ARM_LDC_PC_G2:
8131 case elfcpp::R_ARM_ALU_SB_G0_NC:
8132 case elfcpp::R_ARM_ALU_SB_G0:
8133 case elfcpp::R_ARM_ALU_SB_G1_NC:
8134 case elfcpp::R_ARM_ALU_SB_G1:
8135 case elfcpp::R_ARM_ALU_SB_G2:
8136 case elfcpp::R_ARM_LDR_SB_G0:
8137 case elfcpp::R_ARM_LDR_SB_G1:
8138 case elfcpp::R_ARM_LDR_SB_G2:
8139 case elfcpp::R_ARM_LDRS_SB_G0:
8140 case elfcpp::R_ARM_LDRS_SB_G1:
8141 case elfcpp::R_ARM_LDRS_SB_G2:
8142 case elfcpp::R_ARM_LDC_SB_G0:
8143 case elfcpp::R_ARM_LDC_SB_G1:
8144 case elfcpp::R_ARM_LDC_SB_G2:
8145 case elfcpp::R_ARM_MOVW_BREL_NC:
8146 case elfcpp::R_ARM_MOVT_BREL:
8147 case elfcpp::R_ARM_MOVW_BREL:
8148 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8149 case elfcpp::R_ARM_THM_MOVT_BREL:
8150 case elfcpp::R_ARM_THM_MOVW_BREL:
8151 case elfcpp::R_ARM_GOTOFF32:
8152 case elfcpp::R_ARM_GOTOFF12:
8153 case elfcpp::R_ARM_SBREL31:
8154 return Symbol::RELATIVE_REF;
8155
8156 case elfcpp::R_ARM_PLT32:
8157 case elfcpp::R_ARM_CALL:
8158 case elfcpp::R_ARM_JUMP24:
8159 case elfcpp::R_ARM_THM_CALL:
8160 case elfcpp::R_ARM_THM_JUMP24:
8161 case elfcpp::R_ARM_THM_JUMP19:
8162 case elfcpp::R_ARM_THM_JUMP6:
8163 case elfcpp::R_ARM_THM_JUMP11:
8164 case elfcpp::R_ARM_THM_JUMP8:
8165 // R_ARM_PREL31 is not used to relocate call/jump instructions but
8166 // in unwind tables. It may point to functions via PLTs.
8167 // So we treat it like call/jump relocations above.
8168 case elfcpp::R_ARM_PREL31:
8169 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
8170
8171 case elfcpp::R_ARM_GOT_BREL:
8172 case elfcpp::R_ARM_GOT_ABS:
8173 case elfcpp::R_ARM_GOT_PREL:
8174 // Absolute in GOT.
8175 return Symbol::ABSOLUTE_REF;
8176
8177 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8178 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8179 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8180 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8181 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8182 return Symbol::TLS_REF;
8183
8184 case elfcpp::R_ARM_TARGET1:
8185 case elfcpp::R_ARM_TARGET2:
8186 case elfcpp::R_ARM_COPY:
8187 case elfcpp::R_ARM_GLOB_DAT:
8188 case elfcpp::R_ARM_JUMP_SLOT:
8189 case elfcpp::R_ARM_RELATIVE:
8190 case elfcpp::R_ARM_PC24:
8191 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8192 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8193 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8194 default:
8195 // Not expected. We will give an error later.
8196 return 0;
8197 }
8198 }
8199
8200 // Report an unsupported relocation against a local symbol.
8201
8202 template<bool big_endian>
8203 void
8204 Target_arm<big_endian>::Scan::unsupported_reloc_local(
8205 Sized_relobj_file<32, big_endian>* object,
8206 unsigned int r_type)
8207 {
8208 gold_error(_("%s: unsupported reloc %u against local symbol"),
8209 object->name().c_str(), r_type);
8210 }
8211
8212 // We are about to emit a dynamic relocation of type R_TYPE. If the
8213 // dynamic linker does not support it, issue an error. The GNU linker
8214 // only issues a non-PIC error for an allocated read-only section.
8215 // Here we know the section is allocated, but we don't know that it is
8216 // read-only. But we check for all the relocation types which the
8217 // glibc dynamic linker supports, so it seems appropriate to issue an
8218 // error even if the section is not read-only.
8219
8220 template<bool big_endian>
8221 void
8222 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
8223 unsigned int r_type)
8224 {
8225 switch (r_type)
8226 {
8227 // These are the relocation types supported by glibc for ARM.
8228 case elfcpp::R_ARM_RELATIVE:
8229 case elfcpp::R_ARM_COPY:
8230 case elfcpp::R_ARM_GLOB_DAT:
8231 case elfcpp::R_ARM_JUMP_SLOT:
8232 case elfcpp::R_ARM_ABS32:
8233 case elfcpp::R_ARM_ABS32_NOI:
8234 case elfcpp::R_ARM_IRELATIVE:
8235 case elfcpp::R_ARM_PC24:
8236 // FIXME: The following 3 types are not supported by Android's dynamic
8237 // linker.
8238 case elfcpp::R_ARM_TLS_DTPMOD32:
8239 case elfcpp::R_ARM_TLS_DTPOFF32:
8240 case elfcpp::R_ARM_TLS_TPOFF32:
8241 return;
8242
8243 default:
8244 {
8245 // This prevents us from issuing more than one error per reloc
8246 // section. But we can still wind up issuing more than one
8247 // error per object file.
8248 if (this->issued_non_pic_error_)
8249 return;
8250 const Arm_reloc_property* reloc_property =
8251 arm_reloc_property_table->get_reloc_property(r_type);
8252 gold_assert(reloc_property != NULL);
8253 object->error(_("requires unsupported dynamic reloc %s; "
8254 "recompile with -fPIC"),
8255 reloc_property->name().c_str());
8256 this->issued_non_pic_error_ = true;
8257 return;
8258 }
8259
8260 case elfcpp::R_ARM_NONE:
8261 gold_unreachable();
8262 }
8263 }
8264
8265
8266 // Return whether we need to make a PLT entry for a relocation of the
8267 // given type against a STT_GNU_IFUNC symbol.
8268
8269 template<bool big_endian>
8270 bool
8271 Target_arm<big_endian>::Scan::reloc_needs_plt_for_ifunc(
8272 Sized_relobj_file<32, big_endian>* object,
8273 unsigned int r_type)
8274 {
8275 int flags = Scan::get_reference_flags(r_type);
8276 if (flags & Symbol::TLS_REF)
8277 {
8278 gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
8279 object->name().c_str(), r_type);
8280 return false;
8281 }
8282 return flags != 0;
8283 }
8284
8285
8286 // Scan a relocation for a local symbol.
8287 // FIXME: This only handles a subset of relocation types used by Android
8288 // on ARM v5te devices.
8289
8290 template<bool big_endian>
8291 inline void
8292 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
8293 Layout* layout,
8294 Target_arm* target,
8295 Sized_relobj_file<32, big_endian>* object,
8296 unsigned int data_shndx,
8297 Output_section* output_section,
8298 const elfcpp::Rel<32, big_endian>& reloc,
8299 unsigned int r_type,
8300 const elfcpp::Sym<32, big_endian>& lsym,
8301 bool is_discarded)
8302 {
8303 if (is_discarded)
8304 return;
8305
8306 r_type = get_real_reloc_type(r_type);
8307
8308 // A local STT_GNU_IFUNC symbol may require a PLT entry.
8309 bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
8310 if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
8311 {
8312 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8313 target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
8314 }
8315
8316 switch (r_type)
8317 {
8318 case elfcpp::R_ARM_NONE:
8319 case elfcpp::R_ARM_V4BX:
8320 case elfcpp::R_ARM_GNU_VTENTRY:
8321 case elfcpp::R_ARM_GNU_VTINHERIT:
8322 break;
8323
8324 case elfcpp::R_ARM_ABS32:
8325 case elfcpp::R_ARM_ABS32_NOI:
8326 // If building a shared library (or a position-independent
8327 // executable), we need to create a dynamic relocation for
8328 // this location. The relocation applied at link time will
8329 // apply the link-time value, so we flag the location with
8330 // an R_ARM_RELATIVE relocation so the dynamic loader can
8331 // relocate it easily.
8332 if (parameters->options().output_is_position_independent())
8333 {
8334 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8335 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8336 // If we are to add more other reloc types than R_ARM_ABS32,
8337 // we need to add check_non_pic(object, r_type) here.
8338 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
8339 output_section, data_shndx,
8340 reloc.get_r_offset(), is_ifunc);
8341 }
8342 break;
8343
8344 case elfcpp::R_ARM_ABS16:
8345 case elfcpp::R_ARM_ABS12:
8346 case elfcpp::R_ARM_THM_ABS5:
8347 case elfcpp::R_ARM_ABS8:
8348 case elfcpp::R_ARM_BASE_ABS:
8349 case elfcpp::R_ARM_MOVW_ABS_NC:
8350 case elfcpp::R_ARM_MOVT_ABS:
8351 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8352 case elfcpp::R_ARM_THM_MOVT_ABS:
8353 // If building a shared library (or a position-independent
8354 // executable), we need to create a dynamic relocation for
8355 // this location. Because the addend needs to remain in the
8356 // data section, we need to be careful not to apply this
8357 // relocation statically.
8358 if (parameters->options().output_is_position_independent())
8359 {
8360 check_non_pic(object, r_type);
8361 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8362 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8363 if (lsym.get_st_type() != elfcpp::STT_SECTION)
8364 rel_dyn->add_local(object, r_sym, r_type, output_section,
8365 data_shndx, reloc.get_r_offset());
8366 else
8367 {
8368 gold_assert(lsym.get_st_value() == 0);
8369 unsigned int shndx = lsym.get_st_shndx();
8370 bool is_ordinary;
8371 shndx = object->adjust_sym_shndx(r_sym, shndx,
8372 &is_ordinary);
8373 if (!is_ordinary)
8374 object->error(_("section symbol %u has bad shndx %u"),
8375 r_sym, shndx);
8376 else
8377 rel_dyn->add_local_section(object, shndx,
8378 r_type, output_section,
8379 data_shndx, reloc.get_r_offset());
8380 }
8381 }
8382 break;
8383
8384 case elfcpp::R_ARM_REL32:
8385 case elfcpp::R_ARM_LDR_PC_G0:
8386 case elfcpp::R_ARM_SBREL32:
8387 case elfcpp::R_ARM_THM_CALL:
8388 case elfcpp::R_ARM_THM_PC8:
8389 case elfcpp::R_ARM_BASE_PREL:
8390 case elfcpp::R_ARM_PLT32:
8391 case elfcpp::R_ARM_CALL:
8392 case elfcpp::R_ARM_JUMP24:
8393 case elfcpp::R_ARM_THM_JUMP24:
8394 case elfcpp::R_ARM_SBREL31:
8395 case elfcpp::R_ARM_PREL31:
8396 case elfcpp::R_ARM_MOVW_PREL_NC:
8397 case elfcpp::R_ARM_MOVT_PREL:
8398 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8399 case elfcpp::R_ARM_THM_MOVT_PREL:
8400 case elfcpp::R_ARM_THM_JUMP19:
8401 case elfcpp::R_ARM_THM_JUMP6:
8402 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8403 case elfcpp::R_ARM_THM_PC12:
8404 case elfcpp::R_ARM_REL32_NOI:
8405 case elfcpp::R_ARM_ALU_PC_G0_NC:
8406 case elfcpp::R_ARM_ALU_PC_G0:
8407 case elfcpp::R_ARM_ALU_PC_G1_NC:
8408 case elfcpp::R_ARM_ALU_PC_G1:
8409 case elfcpp::R_ARM_ALU_PC_G2:
8410 case elfcpp::R_ARM_LDR_PC_G1:
8411 case elfcpp::R_ARM_LDR_PC_G2:
8412 case elfcpp::R_ARM_LDRS_PC_G0:
8413 case elfcpp::R_ARM_LDRS_PC_G1:
8414 case elfcpp::R_ARM_LDRS_PC_G2:
8415 case elfcpp::R_ARM_LDC_PC_G0:
8416 case elfcpp::R_ARM_LDC_PC_G1:
8417 case elfcpp::R_ARM_LDC_PC_G2:
8418 case elfcpp::R_ARM_ALU_SB_G0_NC:
8419 case elfcpp::R_ARM_ALU_SB_G0:
8420 case elfcpp::R_ARM_ALU_SB_G1_NC:
8421 case elfcpp::R_ARM_ALU_SB_G1:
8422 case elfcpp::R_ARM_ALU_SB_G2:
8423 case elfcpp::R_ARM_LDR_SB_G0:
8424 case elfcpp::R_ARM_LDR_SB_G1:
8425 case elfcpp::R_ARM_LDR_SB_G2:
8426 case elfcpp::R_ARM_LDRS_SB_G0:
8427 case elfcpp::R_ARM_LDRS_SB_G1:
8428 case elfcpp::R_ARM_LDRS_SB_G2:
8429 case elfcpp::R_ARM_LDC_SB_G0:
8430 case elfcpp::R_ARM_LDC_SB_G1:
8431 case elfcpp::R_ARM_LDC_SB_G2:
8432 case elfcpp::R_ARM_MOVW_BREL_NC:
8433 case elfcpp::R_ARM_MOVT_BREL:
8434 case elfcpp::R_ARM_MOVW_BREL:
8435 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8436 case elfcpp::R_ARM_THM_MOVT_BREL:
8437 case elfcpp::R_ARM_THM_MOVW_BREL:
8438 case elfcpp::R_ARM_THM_JUMP11:
8439 case elfcpp::R_ARM_THM_JUMP8:
8440 // We don't need to do anything for a relative addressing relocation
8441 // against a local symbol if it does not reference the GOT.
8442 break;
8443
8444 case elfcpp::R_ARM_GOTOFF32:
8445 case elfcpp::R_ARM_GOTOFF12:
8446 // We need a GOT section:
8447 target->got_section(symtab, layout);
8448 break;
8449
8450 case elfcpp::R_ARM_GOT_BREL:
8451 case elfcpp::R_ARM_GOT_PREL:
8452 {
8453 // The symbol requires a GOT entry.
8454 Arm_output_data_got<big_endian>* got =
8455 target->got_section(symtab, layout);
8456 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8457 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8458 {
8459 // If we are generating a shared object, we need to add a
8460 // dynamic RELATIVE relocation for this symbol's GOT entry.
8461 if (parameters->options().output_is_position_independent())
8462 {
8463 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8464 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8465 rel_dyn->add_local_relative(
8466 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8467 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8468 }
8469 }
8470 }
8471 break;
8472
8473 case elfcpp::R_ARM_TARGET1:
8474 case elfcpp::R_ARM_TARGET2:
8475 // This should have been mapped to another type already.
8476 // Fall through.
8477 case elfcpp::R_ARM_COPY:
8478 case elfcpp::R_ARM_GLOB_DAT:
8479 case elfcpp::R_ARM_JUMP_SLOT:
8480 case elfcpp::R_ARM_RELATIVE:
8481 // These are relocations which should only be seen by the
8482 // dynamic linker, and should never be seen here.
8483 gold_error(_("%s: unexpected reloc %u in object file"),
8484 object->name().c_str(), r_type);
8485 break;
8486
8487
8488 // These are initial TLS relocs, which are expected when
8489 // linking.
8490 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8491 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8492 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8493 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8494 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8495 {
8496 bool output_is_shared = parameters->options().shared();
8497 const tls::Tls_optimization optimized_type
8498 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8499 r_type);
8500 switch (r_type)
8501 {
8502 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8503 if (optimized_type == tls::TLSOPT_NONE)
8504 {
8505 // Create a pair of GOT entries for the module index and
8506 // dtv-relative offset.
8507 Arm_output_data_got<big_endian>* got
8508 = target->got_section(symtab, layout);
8509 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8510 unsigned int shndx = lsym.get_st_shndx();
8511 bool is_ordinary;
8512 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8513 if (!is_ordinary)
8514 {
8515 object->error(_("local symbol %u has bad shndx %u"),
8516 r_sym, shndx);
8517 break;
8518 }
8519
8520 if (!parameters->doing_static_link())
8521 got->add_local_pair_with_rel(object, r_sym, shndx,
8522 GOT_TYPE_TLS_PAIR,
8523 target->rel_dyn_section(layout),
8524 elfcpp::R_ARM_TLS_DTPMOD32);
8525 else
8526 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8527 object, r_sym);
8528 }
8529 else
8530 // FIXME: TLS optimization not supported yet.
8531 gold_unreachable();
8532 break;
8533
8534 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8535 if (optimized_type == tls::TLSOPT_NONE)
8536 {
8537 // Create a GOT entry for the module index.
8538 target->got_mod_index_entry(symtab, layout, object);
8539 }
8540 else
8541 // FIXME: TLS optimization not supported yet.
8542 gold_unreachable();
8543 break;
8544
8545 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8546 break;
8547
8548 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8549 layout->set_has_static_tls();
8550 if (optimized_type == tls::TLSOPT_NONE)
8551 {
8552 // Create a GOT entry for the tp-relative offset.
8553 Arm_output_data_got<big_endian>* got
8554 = target->got_section(symtab, layout);
8555 unsigned int r_sym =
8556 elfcpp::elf_r_sym<32>(reloc.get_r_info());
8557 if (!parameters->doing_static_link())
8558 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8559 target->rel_dyn_section(layout),
8560 elfcpp::R_ARM_TLS_TPOFF32);
8561 else if (!object->local_has_got_offset(r_sym,
8562 GOT_TYPE_TLS_OFFSET))
8563 {
8564 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8565 unsigned int got_offset =
8566 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8567 got->add_static_reloc(got_offset,
8568 elfcpp::R_ARM_TLS_TPOFF32, object,
8569 r_sym);
8570 }
8571 }
8572 else
8573 // FIXME: TLS optimization not supported yet.
8574 gold_unreachable();
8575 break;
8576
8577 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8578 layout->set_has_static_tls();
8579 if (output_is_shared)
8580 {
8581 // We need to create a dynamic relocation.
8582 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8583 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8584 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8585 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8586 output_section, data_shndx,
8587 reloc.get_r_offset());
8588 }
8589 break;
8590
8591 default:
8592 gold_unreachable();
8593 }
8594 }
8595 break;
8596
8597 case elfcpp::R_ARM_PC24:
8598 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8599 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8600 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8601 default:
8602 unsupported_reloc_local(object, r_type);
8603 break;
8604 }
8605 }
8606
8607 // Report an unsupported relocation against a global symbol.
8608
8609 template<bool big_endian>
8610 void
8611 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8612 Sized_relobj_file<32, big_endian>* object,
8613 unsigned int r_type,
8614 Symbol* gsym)
8615 {
8616 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8617 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8618 }
8619
8620 template<bool big_endian>
8621 inline bool
8622 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8623 unsigned int r_type)
8624 {
8625 switch (r_type)
8626 {
8627 case elfcpp::R_ARM_PC24:
8628 case elfcpp::R_ARM_THM_CALL:
8629 case elfcpp::R_ARM_PLT32:
8630 case elfcpp::R_ARM_CALL:
8631 case elfcpp::R_ARM_JUMP24:
8632 case elfcpp::R_ARM_THM_JUMP24:
8633 case elfcpp::R_ARM_SBREL31:
8634 case elfcpp::R_ARM_PREL31:
8635 case elfcpp::R_ARM_THM_JUMP19:
8636 case elfcpp::R_ARM_THM_JUMP6:
8637 case elfcpp::R_ARM_THM_JUMP11:
8638 case elfcpp::R_ARM_THM_JUMP8:
8639 // All the relocations above are branches except SBREL31 and PREL31.
8640 return false;
8641
8642 default:
8643 // Be conservative and assume this is a function pointer.
8644 return true;
8645 }
8646 }
8647
8648 template<bool big_endian>
8649 inline bool
8650 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8651 Symbol_table*,
8652 Layout*,
8653 Target_arm<big_endian>* target,
8654 Sized_relobj_file<32, big_endian>*,
8655 unsigned int,
8656 Output_section*,
8657 const elfcpp::Rel<32, big_endian>&,
8658 unsigned int r_type,
8659 const elfcpp::Sym<32, big_endian>&)
8660 {
8661 r_type = target->get_real_reloc_type(r_type);
8662 return possible_function_pointer_reloc(r_type);
8663 }
8664
8665 template<bool big_endian>
8666 inline bool
8667 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8668 Symbol_table*,
8669 Layout*,
8670 Target_arm<big_endian>* target,
8671 Sized_relobj_file<32, big_endian>*,
8672 unsigned int,
8673 Output_section*,
8674 const elfcpp::Rel<32, big_endian>&,
8675 unsigned int r_type,
8676 Symbol* gsym)
8677 {
8678 // GOT is not a function.
8679 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8680 return false;
8681
8682 r_type = target->get_real_reloc_type(r_type);
8683 return possible_function_pointer_reloc(r_type);
8684 }
8685
8686 // Scan a relocation for a global symbol.
8687
8688 template<bool big_endian>
8689 inline void
8690 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8691 Layout* layout,
8692 Target_arm* target,
8693 Sized_relobj_file<32, big_endian>* object,
8694 unsigned int data_shndx,
8695 Output_section* output_section,
8696 const elfcpp::Rel<32, big_endian>& reloc,
8697 unsigned int r_type,
8698 Symbol* gsym)
8699 {
8700 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8701 // section. We check here to avoid creating a dynamic reloc against
8702 // _GLOBAL_OFFSET_TABLE_.
8703 if (!target->has_got_section()
8704 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8705 target->got_section(symtab, layout);
8706
8707 // A STT_GNU_IFUNC symbol may require a PLT entry.
8708 if (gsym->type() == elfcpp::STT_GNU_IFUNC
8709 && this->reloc_needs_plt_for_ifunc(object, r_type))
8710 target->make_plt_entry(symtab, layout, gsym);
8711
8712 r_type = get_real_reloc_type(r_type);
8713 switch (r_type)
8714 {
8715 case elfcpp::R_ARM_NONE:
8716 case elfcpp::R_ARM_V4BX:
8717 case elfcpp::R_ARM_GNU_VTENTRY:
8718 case elfcpp::R_ARM_GNU_VTINHERIT:
8719 break;
8720
8721 case elfcpp::R_ARM_ABS32:
8722 case elfcpp::R_ARM_ABS16:
8723 case elfcpp::R_ARM_ABS12:
8724 case elfcpp::R_ARM_THM_ABS5:
8725 case elfcpp::R_ARM_ABS8:
8726 case elfcpp::R_ARM_BASE_ABS:
8727 case elfcpp::R_ARM_MOVW_ABS_NC:
8728 case elfcpp::R_ARM_MOVT_ABS:
8729 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8730 case elfcpp::R_ARM_THM_MOVT_ABS:
8731 case elfcpp::R_ARM_ABS32_NOI:
8732 // Absolute addressing relocations.
8733 {
8734 // Make a PLT entry if necessary.
8735 if (this->symbol_needs_plt_entry(gsym))
8736 {
8737 target->make_plt_entry(symtab, layout, gsym);
8738 // Since this is not a PC-relative relocation, we may be
8739 // taking the address of a function. In that case we need to
8740 // set the entry in the dynamic symbol table to the address of
8741 // the PLT entry.
8742 if (gsym->is_from_dynobj() && !parameters->options().shared())
8743 gsym->set_needs_dynsym_value();
8744 }
8745 // Make a dynamic relocation if necessary.
8746 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8747 {
8748 if (!parameters->options().output_is_position_independent()
8749 && gsym->may_need_copy_reloc())
8750 {
8751 target->copy_reloc(symtab, layout, object,
8752 data_shndx, output_section, gsym, reloc);
8753 }
8754 else if ((r_type == elfcpp::R_ARM_ABS32
8755 || r_type == elfcpp::R_ARM_ABS32_NOI)
8756 && gsym->type() == elfcpp::STT_GNU_IFUNC
8757 && gsym->can_use_relative_reloc(false)
8758 && !gsym->is_from_dynobj()
8759 && !gsym->is_undefined()
8760 && !gsym->is_preemptible())
8761 {
8762 // Use an IRELATIVE reloc for a locally defined STT_GNU_IFUNC
8763 // symbol. This makes a function address in a PIE executable
8764 // match the address in a shared library that it links against.
8765 Reloc_section* rel_irelative =
8766 target->rel_irelative_section(layout);
8767 unsigned int r_type = elfcpp::R_ARM_IRELATIVE;
8768 rel_irelative->add_symbolless_global_addend(
8769 gsym, r_type, output_section, object,
8770 data_shndx, reloc.get_r_offset());
8771 }
8772 else if ((r_type == elfcpp::R_ARM_ABS32
8773 || r_type == elfcpp::R_ARM_ABS32_NOI)
8774 && gsym->can_use_relative_reloc(false))
8775 {
8776 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8777 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8778 output_section, object,
8779 data_shndx, reloc.get_r_offset());
8780 }
8781 else
8782 {
8783 check_non_pic(object, r_type);
8784 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8785 rel_dyn->add_global(gsym, r_type, output_section, object,
8786 data_shndx, reloc.get_r_offset());
8787 }
8788 }
8789 }
8790 break;
8791
8792 case elfcpp::R_ARM_GOTOFF32:
8793 case elfcpp::R_ARM_GOTOFF12:
8794 // We need a GOT section.
8795 target->got_section(symtab, layout);
8796 break;
8797
8798 case elfcpp::R_ARM_REL32:
8799 case elfcpp::R_ARM_LDR_PC_G0:
8800 case elfcpp::R_ARM_SBREL32:
8801 case elfcpp::R_ARM_THM_PC8:
8802 case elfcpp::R_ARM_BASE_PREL:
8803 case elfcpp::R_ARM_MOVW_PREL_NC:
8804 case elfcpp::R_ARM_MOVT_PREL:
8805 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8806 case elfcpp::R_ARM_THM_MOVT_PREL:
8807 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8808 case elfcpp::R_ARM_THM_PC12:
8809 case elfcpp::R_ARM_REL32_NOI:
8810 case elfcpp::R_ARM_ALU_PC_G0_NC:
8811 case elfcpp::R_ARM_ALU_PC_G0:
8812 case elfcpp::R_ARM_ALU_PC_G1_NC:
8813 case elfcpp::R_ARM_ALU_PC_G1:
8814 case elfcpp::R_ARM_ALU_PC_G2:
8815 case elfcpp::R_ARM_LDR_PC_G1:
8816 case elfcpp::R_ARM_LDR_PC_G2:
8817 case elfcpp::R_ARM_LDRS_PC_G0:
8818 case elfcpp::R_ARM_LDRS_PC_G1:
8819 case elfcpp::R_ARM_LDRS_PC_G2:
8820 case elfcpp::R_ARM_LDC_PC_G0:
8821 case elfcpp::R_ARM_LDC_PC_G1:
8822 case elfcpp::R_ARM_LDC_PC_G2:
8823 case elfcpp::R_ARM_ALU_SB_G0_NC:
8824 case elfcpp::R_ARM_ALU_SB_G0:
8825 case elfcpp::R_ARM_ALU_SB_G1_NC:
8826 case elfcpp::R_ARM_ALU_SB_G1:
8827 case elfcpp::R_ARM_ALU_SB_G2:
8828 case elfcpp::R_ARM_LDR_SB_G0:
8829 case elfcpp::R_ARM_LDR_SB_G1:
8830 case elfcpp::R_ARM_LDR_SB_G2:
8831 case elfcpp::R_ARM_LDRS_SB_G0:
8832 case elfcpp::R_ARM_LDRS_SB_G1:
8833 case elfcpp::R_ARM_LDRS_SB_G2:
8834 case elfcpp::R_ARM_LDC_SB_G0:
8835 case elfcpp::R_ARM_LDC_SB_G1:
8836 case elfcpp::R_ARM_LDC_SB_G2:
8837 case elfcpp::R_ARM_MOVW_BREL_NC:
8838 case elfcpp::R_ARM_MOVT_BREL:
8839 case elfcpp::R_ARM_MOVW_BREL:
8840 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8841 case elfcpp::R_ARM_THM_MOVT_BREL:
8842 case elfcpp::R_ARM_THM_MOVW_BREL:
8843 // Relative addressing relocations.
8844 {
8845 // Make a dynamic relocation if necessary.
8846 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8847 {
8848 if (parameters->options().output_is_executable()
8849 && target->may_need_copy_reloc(gsym))
8850 {
8851 target->copy_reloc(symtab, layout, object,
8852 data_shndx, output_section, gsym, reloc);
8853 }
8854 else
8855 {
8856 check_non_pic(object, r_type);
8857 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8858 rel_dyn->add_global(gsym, r_type, output_section, object,
8859 data_shndx, reloc.get_r_offset());
8860 }
8861 }
8862 }
8863 break;
8864
8865 case elfcpp::R_ARM_THM_CALL:
8866 case elfcpp::R_ARM_PLT32:
8867 case elfcpp::R_ARM_CALL:
8868 case elfcpp::R_ARM_JUMP24:
8869 case elfcpp::R_ARM_THM_JUMP24:
8870 case elfcpp::R_ARM_SBREL31:
8871 case elfcpp::R_ARM_PREL31:
8872 case elfcpp::R_ARM_THM_JUMP19:
8873 case elfcpp::R_ARM_THM_JUMP6:
8874 case elfcpp::R_ARM_THM_JUMP11:
8875 case elfcpp::R_ARM_THM_JUMP8:
8876 // All the relocation above are branches except for the PREL31 ones.
8877 // A PREL31 relocation can point to a personality function in a shared
8878 // library. In that case we want to use a PLT because we want to
8879 // call the personality routine and the dynamic linkers we care about
8880 // do not support dynamic PREL31 relocations. An REL31 relocation may
8881 // point to a function whose unwinding behaviour is being described but
8882 // we will not mistakenly generate a PLT for that because we should use
8883 // a local section symbol.
8884
8885 // If the symbol is fully resolved, this is just a relative
8886 // local reloc. Otherwise we need a PLT entry.
8887 if (gsym->final_value_is_known())
8888 break;
8889 // If building a shared library, we can also skip the PLT entry
8890 // if the symbol is defined in the output file and is protected
8891 // or hidden.
8892 if (gsym->is_defined()
8893 && !gsym->is_from_dynobj()
8894 && !gsym->is_preemptible())
8895 break;
8896 target->make_plt_entry(symtab, layout, gsym);
8897 break;
8898
8899 case elfcpp::R_ARM_GOT_BREL:
8900 case elfcpp::R_ARM_GOT_ABS:
8901 case elfcpp::R_ARM_GOT_PREL:
8902 {
8903 // The symbol requires a GOT entry.
8904 Arm_output_data_got<big_endian>* got =
8905 target->got_section(symtab, layout);
8906 if (gsym->final_value_is_known())
8907 {
8908 // For a STT_GNU_IFUNC symbol we want the PLT address.
8909 if (gsym->type() == elfcpp::STT_GNU_IFUNC)
8910 got->add_global_plt(gsym, GOT_TYPE_STANDARD);
8911 else
8912 got->add_global(gsym, GOT_TYPE_STANDARD);
8913 }
8914 else
8915 {
8916 // If this symbol is not fully resolved, we need to add a
8917 // GOT entry with a dynamic relocation.
8918 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8919 if (gsym->is_from_dynobj()
8920 || gsym->is_undefined()
8921 || gsym->is_preemptible()
8922 || (gsym->visibility() == elfcpp::STV_PROTECTED
8923 && parameters->options().shared())
8924 || (gsym->type() == elfcpp::STT_GNU_IFUNC
8925 && parameters->options().output_is_position_independent()))
8926 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8927 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8928 else
8929 {
8930 // For a STT_GNU_IFUNC symbol we want to write the PLT
8931 // offset into the GOT, so that function pointer
8932 // comparisons work correctly.
8933 bool is_new;
8934 if (gsym->type() != elfcpp::STT_GNU_IFUNC)
8935 is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
8936 else
8937 {
8938 is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
8939 // Tell the dynamic linker to use the PLT address
8940 // when resolving relocations.
8941 if (gsym->is_from_dynobj()
8942 && !parameters->options().shared())
8943 gsym->set_needs_dynsym_value();
8944 }
8945 if (is_new)
8946 rel_dyn->add_global_relative(
8947 gsym, elfcpp::R_ARM_RELATIVE, got,
8948 gsym->got_offset(GOT_TYPE_STANDARD));
8949 }
8950 }
8951 }
8952 break;
8953
8954 case elfcpp::R_ARM_TARGET1:
8955 case elfcpp::R_ARM_TARGET2:
8956 // These should have been mapped to other types already.
8957 // Fall through.
8958 case elfcpp::R_ARM_COPY:
8959 case elfcpp::R_ARM_GLOB_DAT:
8960 case elfcpp::R_ARM_JUMP_SLOT:
8961 case elfcpp::R_ARM_RELATIVE:
8962 // These are relocations which should only be seen by the
8963 // dynamic linker, and should never be seen here.
8964 gold_error(_("%s: unexpected reloc %u in object file"),
8965 object->name().c_str(), r_type);
8966 break;
8967
8968 // These are initial tls relocs, which are expected when
8969 // linking.
8970 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8971 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8972 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8973 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8974 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8975 {
8976 const bool is_final = gsym->final_value_is_known();
8977 const tls::Tls_optimization optimized_type
8978 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8979 switch (r_type)
8980 {
8981 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8982 if (optimized_type == tls::TLSOPT_NONE)
8983 {
8984 // Create a pair of GOT entries for the module index and
8985 // dtv-relative offset.
8986 Arm_output_data_got<big_endian>* got
8987 = target->got_section(symtab, layout);
8988 if (!parameters->doing_static_link())
8989 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8990 target->rel_dyn_section(layout),
8991 elfcpp::R_ARM_TLS_DTPMOD32,
8992 elfcpp::R_ARM_TLS_DTPOFF32);
8993 else
8994 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8995 }
8996 else
8997 // FIXME: TLS optimization not supported yet.
8998 gold_unreachable();
8999 break;
9000
9001 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9002 if (optimized_type == tls::TLSOPT_NONE)
9003 {
9004 // Create a GOT entry for the module index.
9005 target->got_mod_index_entry(symtab, layout, object);
9006 }
9007 else
9008 // FIXME: TLS optimization not supported yet.
9009 gold_unreachable();
9010 break;
9011
9012 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9013 break;
9014
9015 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9016 layout->set_has_static_tls();
9017 if (optimized_type == tls::TLSOPT_NONE)
9018 {
9019 // Create a GOT entry for the tp-relative offset.
9020 Arm_output_data_got<big_endian>* got
9021 = target->got_section(symtab, layout);
9022 if (!parameters->doing_static_link())
9023 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
9024 target->rel_dyn_section(layout),
9025 elfcpp::R_ARM_TLS_TPOFF32);
9026 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
9027 {
9028 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
9029 unsigned int got_offset =
9030 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
9031 got->add_static_reloc(got_offset,
9032 elfcpp::R_ARM_TLS_TPOFF32, gsym);
9033 }
9034 }
9035 else
9036 // FIXME: TLS optimization not supported yet.
9037 gold_unreachable();
9038 break;
9039
9040 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9041 layout->set_has_static_tls();
9042 if (parameters->options().shared())
9043 {
9044 // We need to create a dynamic relocation.
9045 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
9046 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
9047 output_section, object,
9048 data_shndx, reloc.get_r_offset());
9049 }
9050 break;
9051
9052 default:
9053 gold_unreachable();
9054 }
9055 }
9056 break;
9057
9058 case elfcpp::R_ARM_PC24:
9059 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9060 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9061 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9062 default:
9063 unsupported_reloc_global(object, r_type, gsym);
9064 break;
9065 }
9066 }
9067
9068 // Process relocations for gc.
9069
9070 template<bool big_endian>
9071 void
9072 Target_arm<big_endian>::gc_process_relocs(
9073 Symbol_table* symtab,
9074 Layout* layout,
9075 Sized_relobj_file<32, big_endian>* object,
9076 unsigned int data_shndx,
9077 unsigned int,
9078 const unsigned char* prelocs,
9079 size_t reloc_count,
9080 Output_section* output_section,
9081 bool needs_special_offset_handling,
9082 size_t local_symbol_count,
9083 const unsigned char* plocal_symbols)
9084 {
9085 typedef Target_arm<big_endian> Arm;
9086 typedef typename Target_arm<big_endian>::Scan Scan;
9087
9088 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
9089 typename Target_arm::Relocatable_size_for_reloc>(
9090 symtab,
9091 layout,
9092 this,
9093 object,
9094 data_shndx,
9095 prelocs,
9096 reloc_count,
9097 output_section,
9098 needs_special_offset_handling,
9099 local_symbol_count,
9100 plocal_symbols);
9101 }
9102
9103 // Scan relocations for a section.
9104
9105 template<bool big_endian>
9106 void
9107 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
9108 Layout* layout,
9109 Sized_relobj_file<32, big_endian>* object,
9110 unsigned int data_shndx,
9111 unsigned int sh_type,
9112 const unsigned char* prelocs,
9113 size_t reloc_count,
9114 Output_section* output_section,
9115 bool needs_special_offset_handling,
9116 size_t local_symbol_count,
9117 const unsigned char* plocal_symbols)
9118 {
9119 typedef typename Target_arm<big_endian>::Scan Scan;
9120 if (sh_type == elfcpp::SHT_RELA)
9121 {
9122 gold_error(_("%s: unsupported RELA reloc section"),
9123 object->name().c_str());
9124 return;
9125 }
9126
9127 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
9128 symtab,
9129 layout,
9130 this,
9131 object,
9132 data_shndx,
9133 prelocs,
9134 reloc_count,
9135 output_section,
9136 needs_special_offset_handling,
9137 local_symbol_count,
9138 plocal_symbols);
9139 }
9140
9141 // Finalize the sections.
9142
9143 template<bool big_endian>
9144 void
9145 Target_arm<big_endian>::do_finalize_sections(
9146 Layout* layout,
9147 const Input_objects* input_objects,
9148 Symbol_table*)
9149 {
9150 bool merged_any_attributes = false;
9151 // Merge processor-specific flags.
9152 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
9153 p != input_objects->relobj_end();
9154 ++p)
9155 {
9156 Arm_relobj<big_endian>* arm_relobj =
9157 Arm_relobj<big_endian>::as_arm_relobj(*p);
9158 if (arm_relobj->merge_flags_and_attributes())
9159 {
9160 this->merge_processor_specific_flags(
9161 arm_relobj->name(),
9162 arm_relobj->processor_specific_flags());
9163 this->merge_object_attributes(arm_relobj->name().c_str(),
9164 arm_relobj->attributes_section_data());
9165 merged_any_attributes = true;
9166 }
9167 }
9168
9169 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
9170 p != input_objects->dynobj_end();
9171 ++p)
9172 {
9173 Arm_dynobj<big_endian>* arm_dynobj =
9174 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
9175 this->merge_processor_specific_flags(
9176 arm_dynobj->name(),
9177 arm_dynobj->processor_specific_flags());
9178 this->merge_object_attributes(arm_dynobj->name().c_str(),
9179 arm_dynobj->attributes_section_data());
9180 merged_any_attributes = true;
9181 }
9182
9183 // Create an empty uninitialized attribute section if we still don't have it
9184 // at this moment. This happens if there is no attributes sections in all
9185 // inputs.
9186 if (this->attributes_section_data_ == NULL)
9187 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
9188
9189 const Object_attribute* cpu_arch_attr =
9190 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
9191 // Check if we need to use Cortex-A8 workaround.
9192 if (parameters->options().user_set_fix_cortex_a8())
9193 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
9194 else
9195 {
9196 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
9197 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
9198 // profile.
9199 const Object_attribute* cpu_arch_profile_attr =
9200 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
9201 this->fix_cortex_a8_ =
9202 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
9203 && (cpu_arch_profile_attr->int_value() == 'A'
9204 || cpu_arch_profile_attr->int_value() == 0));
9205 }
9206
9207 // Check if we can use V4BX interworking.
9208 // The V4BX interworking stub contains BX instruction,
9209 // which is not specified for some profiles.
9210 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
9211 && !this->may_use_v4t_interworking())
9212 gold_error(_("unable to provide V4BX reloc interworking fix up; "
9213 "the target profile does not support BX instruction"));
9214
9215 // Fill in some more dynamic tags.
9216 const Reloc_section* rel_plt = (this->plt_ == NULL
9217 ? NULL
9218 : this->plt_->rel_plt());
9219 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
9220 this->rel_dyn_, true, false);
9221
9222 // Emit any relocs we saved in an attempt to avoid generating COPY
9223 // relocs.
9224 if (this->copy_relocs_.any_saved_relocs())
9225 this->copy_relocs_.emit(this->rel_dyn_section(layout));
9226
9227 // Handle the .ARM.exidx section.
9228 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
9229
9230 if (!parameters->options().relocatable())
9231 {
9232 if (exidx_section != NULL
9233 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
9234 {
9235 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
9236 // the .ARM.exidx section.
9237 if (!layout->script_options()->saw_phdrs_clause())
9238 {
9239 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
9240 0)
9241 == NULL);
9242 Output_segment* exidx_segment =
9243 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
9244 exidx_segment->add_output_section_to_nonload(exidx_section,
9245 elfcpp::PF_R);
9246 }
9247 }
9248 }
9249
9250 // Create an .ARM.attributes section if we have merged any attributes
9251 // from inputs.
9252 if (merged_any_attributes)
9253 {
9254 Output_attributes_section_data* attributes_section =
9255 new Output_attributes_section_data(*this->attributes_section_data_);
9256 layout->add_output_section_data(".ARM.attributes",
9257 elfcpp::SHT_ARM_ATTRIBUTES, 0,
9258 attributes_section, ORDER_INVALID,
9259 false);
9260 }
9261
9262 // Fix up links in section EXIDX headers.
9263 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
9264 p != layout->section_list().end();
9265 ++p)
9266 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
9267 {
9268 Arm_output_section<big_endian>* os =
9269 Arm_output_section<big_endian>::as_arm_output_section(*p);
9270 os->set_exidx_section_link();
9271 }
9272 }
9273
9274 // Return whether a direct absolute static relocation needs to be applied.
9275 // In cases where Scan::local() or Scan::global() has created
9276 // a dynamic relocation other than R_ARM_RELATIVE, the addend
9277 // of the relocation is carried in the data, and we must not
9278 // apply the static relocation.
9279
9280 template<bool big_endian>
9281 inline bool
9282 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
9283 const Sized_symbol<32>* gsym,
9284 unsigned int r_type,
9285 bool is_32bit,
9286 Output_section* output_section)
9287 {
9288 // If the output section is not allocated, then we didn't call
9289 // scan_relocs, we didn't create a dynamic reloc, and we must apply
9290 // the reloc here.
9291 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
9292 return true;
9293
9294 int ref_flags = Scan::get_reference_flags(r_type);
9295
9296 // For local symbols, we will have created a non-RELATIVE dynamic
9297 // relocation only if (a) the output is position independent,
9298 // (b) the relocation is absolute (not pc- or segment-relative), and
9299 // (c) the relocation is not 32 bits wide.
9300 if (gsym == NULL)
9301 return !(parameters->options().output_is_position_independent()
9302 && (ref_flags & Symbol::ABSOLUTE_REF)
9303 && !is_32bit);
9304
9305 // For global symbols, we use the same helper routines used in the
9306 // scan pass. If we did not create a dynamic relocation, or if we
9307 // created a RELATIVE dynamic relocation, we should apply the static
9308 // relocation.
9309 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
9310 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
9311 && gsym->can_use_relative_reloc(ref_flags
9312 & Symbol::FUNCTION_CALL);
9313 return !has_dyn || is_rel;
9314 }
9315
9316 // Perform a relocation.
9317
9318 template<bool big_endian>
9319 inline bool
9320 Target_arm<big_endian>::Relocate::relocate(
9321 const Relocate_info<32, big_endian>* relinfo,
9322 Target_arm* target,
9323 Output_section* output_section,
9324 size_t relnum,
9325 const elfcpp::Rel<32, big_endian>& rel,
9326 unsigned int r_type,
9327 const Sized_symbol<32>* gsym,
9328 const Symbol_value<32>* psymval,
9329 unsigned char* view,
9330 Arm_address address,
9331 section_size_type view_size)
9332 {
9333 if (view == NULL)
9334 return true;
9335
9336 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
9337
9338 r_type = get_real_reloc_type(r_type);
9339 const Arm_reloc_property* reloc_property =
9340 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9341 if (reloc_property == NULL)
9342 {
9343 std::string reloc_name =
9344 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9345 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9346 _("cannot relocate %s in object file"),
9347 reloc_name.c_str());
9348 return true;
9349 }
9350
9351 const Arm_relobj<big_endian>* object =
9352 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9353
9354 // If the final branch target of a relocation is THUMB instruction, this
9355 // is 1. Otherwise it is 0.
9356 Arm_address thumb_bit = 0;
9357 Symbol_value<32> symval;
9358 bool is_weakly_undefined_without_plt = false;
9359 bool have_got_offset = false;
9360 unsigned int got_offset = 0;
9361
9362 // If the relocation uses the GOT entry of a symbol instead of the symbol
9363 // itself, we don't care about whether the symbol is defined or what kind
9364 // of symbol it is.
9365 if (reloc_property->uses_got_entry())
9366 {
9367 // Get the GOT offset.
9368 // The GOT pointer points to the end of the GOT section.
9369 // We need to subtract the size of the GOT section to get
9370 // the actual offset to use in the relocation.
9371 // TODO: We should move GOT offset computing code in TLS relocations
9372 // to here.
9373 switch (r_type)
9374 {
9375 case elfcpp::R_ARM_GOT_BREL:
9376 case elfcpp::R_ARM_GOT_PREL:
9377 if (gsym != NULL)
9378 {
9379 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
9380 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
9381 - target->got_size());
9382 }
9383 else
9384 {
9385 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9386 gold_assert(object->local_has_got_offset(r_sym,
9387 GOT_TYPE_STANDARD));
9388 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
9389 - target->got_size());
9390 }
9391 have_got_offset = true;
9392 break;
9393
9394 default:
9395 break;
9396 }
9397 }
9398 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
9399 {
9400 if (gsym != NULL)
9401 {
9402 // This is a global symbol. Determine if we use PLT and if the
9403 // final target is THUMB.
9404 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
9405 {
9406 // This uses a PLT, change the symbol value.
9407 symval.set_output_value(target->plt_address_for_global(gsym));
9408 psymval = &symval;
9409 }
9410 else if (gsym->is_weak_undefined())
9411 {
9412 // This is a weakly undefined symbol and we do not use PLT
9413 // for this relocation. A branch targeting this symbol will
9414 // be converted into an NOP.
9415 is_weakly_undefined_without_plt = true;
9416 }
9417 else if (gsym->is_undefined() && reloc_property->uses_symbol())
9418 {
9419 // This relocation uses the symbol value but the symbol is
9420 // undefined. Exit early and have the caller reporting an
9421 // error.
9422 return true;
9423 }
9424 else
9425 {
9426 // Set thumb bit if symbol:
9427 // -Has type STT_ARM_TFUNC or
9428 // -Has type STT_FUNC, is defined and with LSB in value set.
9429 thumb_bit =
9430 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
9431 || (gsym->type() == elfcpp::STT_FUNC
9432 && !gsym->is_undefined()
9433 && ((psymval->value(object, 0) & 1) != 0)))
9434 ? 1
9435 : 0);
9436 }
9437 }
9438 else
9439 {
9440 // This is a local symbol. Determine if the final target is THUMB.
9441 // We saved this information when all the local symbols were read.
9442 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
9443 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9444 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9445
9446 if (psymval->is_ifunc_symbol() && object->local_has_plt_offset(r_sym))
9447 {
9448 symval.set_output_value(
9449 target->plt_address_for_local(object, r_sym));
9450 psymval = &symval;
9451 }
9452 }
9453 }
9454 else
9455 {
9456 // This is a fake relocation synthesized for a stub. It does not have
9457 // a real symbol. We just look at the LSB of the symbol value to
9458 // determine if the target is THUMB or not.
9459 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
9460 }
9461
9462 // Strip LSB if this points to a THUMB target.
9463 if (thumb_bit != 0
9464 && reloc_property->uses_thumb_bit()
9465 && ((psymval->value(object, 0) & 1) != 0))
9466 {
9467 Arm_address stripped_value =
9468 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9469 symval.set_output_value(stripped_value);
9470 psymval = &symval;
9471 }
9472
9473 // To look up relocation stubs, we need to pass the symbol table index of
9474 // a local symbol.
9475 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9476
9477 // Get the addressing origin of the output segment defining the
9478 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
9479 Arm_address sym_origin = 0;
9480 if (reloc_property->uses_symbol_base())
9481 {
9482 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
9483 // R_ARM_BASE_ABS with the NULL symbol will give the
9484 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
9485 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
9486 sym_origin = target->got_plt_section()->address();
9487 else if (gsym == NULL)
9488 sym_origin = 0;
9489 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
9490 sym_origin = gsym->output_segment()->vaddr();
9491 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9492 sym_origin = gsym->output_data()->address();
9493
9494 // TODO: Assumes the segment base to be zero for the global symbols
9495 // till the proper support for the segment-base-relative addressing
9496 // will be implemented. This is consistent with GNU ld.
9497 }
9498
9499 // For relative addressing relocation, find out the relative address base.
9500 Arm_address relative_address_base = 0;
9501 switch(reloc_property->relative_address_base())
9502 {
9503 case Arm_reloc_property::RAB_NONE:
9504 // Relocations with relative address bases RAB_TLS and RAB_tp are
9505 // handled by relocate_tls. So we do not need to do anything here.
9506 case Arm_reloc_property::RAB_TLS:
9507 case Arm_reloc_property::RAB_tp:
9508 break;
9509 case Arm_reloc_property::RAB_B_S:
9510 relative_address_base = sym_origin;
9511 break;
9512 case Arm_reloc_property::RAB_GOT_ORG:
9513 relative_address_base = target->got_plt_section()->address();
9514 break;
9515 case Arm_reloc_property::RAB_P:
9516 relative_address_base = address;
9517 break;
9518 case Arm_reloc_property::RAB_Pa:
9519 relative_address_base = address & 0xfffffffcU;
9520 break;
9521 default:
9522 gold_unreachable();
9523 }
9524
9525 typename Arm_relocate_functions::Status reloc_status =
9526 Arm_relocate_functions::STATUS_OKAY;
9527 bool check_overflow = reloc_property->checks_overflow();
9528 switch (r_type)
9529 {
9530 case elfcpp::R_ARM_NONE:
9531 break;
9532
9533 case elfcpp::R_ARM_ABS8:
9534 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9535 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9536 break;
9537
9538 case elfcpp::R_ARM_ABS12:
9539 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9540 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9541 break;
9542
9543 case elfcpp::R_ARM_ABS16:
9544 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9545 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9546 break;
9547
9548 case elfcpp::R_ARM_ABS32:
9549 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9550 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9551 thumb_bit);
9552 break;
9553
9554 case elfcpp::R_ARM_ABS32_NOI:
9555 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9556 // No thumb bit for this relocation: (S + A)
9557 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9558 0);
9559 break;
9560
9561 case elfcpp::R_ARM_MOVW_ABS_NC:
9562 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9563 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9564 0, thumb_bit,
9565 check_overflow);
9566 break;
9567
9568 case elfcpp::R_ARM_MOVT_ABS:
9569 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9570 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9571 break;
9572
9573 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9574 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9575 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9576 0, thumb_bit, false);
9577 break;
9578
9579 case elfcpp::R_ARM_THM_MOVT_ABS:
9580 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9581 reloc_status = Arm_relocate_functions::thm_movt(view, object,
9582 psymval, 0);
9583 break;
9584
9585 case elfcpp::R_ARM_MOVW_PREL_NC:
9586 case elfcpp::R_ARM_MOVW_BREL_NC:
9587 case elfcpp::R_ARM_MOVW_BREL:
9588 reloc_status =
9589 Arm_relocate_functions::movw(view, object, psymval,
9590 relative_address_base, thumb_bit,
9591 check_overflow);
9592 break;
9593
9594 case elfcpp::R_ARM_MOVT_PREL:
9595 case elfcpp::R_ARM_MOVT_BREL:
9596 reloc_status =
9597 Arm_relocate_functions::movt(view, object, psymval,
9598 relative_address_base);
9599 break;
9600
9601 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9602 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9603 case elfcpp::R_ARM_THM_MOVW_BREL:
9604 reloc_status =
9605 Arm_relocate_functions::thm_movw(view, object, psymval,
9606 relative_address_base,
9607 thumb_bit, check_overflow);
9608 break;
9609
9610 case elfcpp::R_ARM_THM_MOVT_PREL:
9611 case elfcpp::R_ARM_THM_MOVT_BREL:
9612 reloc_status =
9613 Arm_relocate_functions::thm_movt(view, object, psymval,
9614 relative_address_base);
9615 break;
9616
9617 case elfcpp::R_ARM_REL32:
9618 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9619 address, thumb_bit);
9620 break;
9621
9622 case elfcpp::R_ARM_THM_ABS5:
9623 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9624 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9625 break;
9626
9627 // Thumb long branches.
9628 case elfcpp::R_ARM_THM_CALL:
9629 case elfcpp::R_ARM_THM_XPC22:
9630 case elfcpp::R_ARM_THM_JUMP24:
9631 reloc_status =
9632 Arm_relocate_functions::thumb_branch_common(
9633 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9634 thumb_bit, is_weakly_undefined_without_plt);
9635 break;
9636
9637 case elfcpp::R_ARM_GOTOFF32:
9638 {
9639 Arm_address got_origin;
9640 got_origin = target->got_plt_section()->address();
9641 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9642 got_origin, thumb_bit);
9643 }
9644 break;
9645
9646 case elfcpp::R_ARM_BASE_PREL:
9647 gold_assert(gsym != NULL);
9648 reloc_status =
9649 Arm_relocate_functions::base_prel(view, sym_origin, address);
9650 break;
9651
9652 case elfcpp::R_ARM_BASE_ABS:
9653 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9654 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9655 break;
9656
9657 case elfcpp::R_ARM_GOT_BREL:
9658 gold_assert(have_got_offset);
9659 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9660 break;
9661
9662 case elfcpp::R_ARM_GOT_PREL:
9663 gold_assert(have_got_offset);
9664 // Get the address origin for GOT PLT, which is allocated right
9665 // after the GOT section, to calculate an absolute address of
9666 // the symbol GOT entry (got_origin + got_offset).
9667 Arm_address got_origin;
9668 got_origin = target->got_plt_section()->address();
9669 reloc_status = Arm_relocate_functions::got_prel(view,
9670 got_origin + got_offset,
9671 address);
9672 break;
9673
9674 case elfcpp::R_ARM_PLT32:
9675 case elfcpp::R_ARM_CALL:
9676 case elfcpp::R_ARM_JUMP24:
9677 case elfcpp::R_ARM_XPC25:
9678 gold_assert(gsym == NULL
9679 || gsym->has_plt_offset()
9680 || gsym->final_value_is_known()
9681 || (gsym->is_defined()
9682 && !gsym->is_from_dynobj()
9683 && !gsym->is_preemptible()));
9684 reloc_status =
9685 Arm_relocate_functions::arm_branch_common(
9686 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9687 thumb_bit, is_weakly_undefined_without_plt);
9688 break;
9689
9690 case elfcpp::R_ARM_THM_JUMP19:
9691 reloc_status =
9692 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9693 thumb_bit);
9694 break;
9695
9696 case elfcpp::R_ARM_THM_JUMP6:
9697 reloc_status =
9698 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9699 break;
9700
9701 case elfcpp::R_ARM_THM_JUMP8:
9702 reloc_status =
9703 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9704 break;
9705
9706 case elfcpp::R_ARM_THM_JUMP11:
9707 reloc_status =
9708 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9709 break;
9710
9711 case elfcpp::R_ARM_PREL31:
9712 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9713 address, thumb_bit);
9714 break;
9715
9716 case elfcpp::R_ARM_V4BX:
9717 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9718 {
9719 const bool is_v4bx_interworking =
9720 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9721 reloc_status =
9722 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9723 is_v4bx_interworking);
9724 }
9725 break;
9726
9727 case elfcpp::R_ARM_THM_PC8:
9728 reloc_status =
9729 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9730 break;
9731
9732 case elfcpp::R_ARM_THM_PC12:
9733 reloc_status =
9734 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9735 break;
9736
9737 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9738 reloc_status =
9739 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9740 thumb_bit);
9741 break;
9742
9743 case elfcpp::R_ARM_ALU_PC_G0_NC:
9744 case elfcpp::R_ARM_ALU_PC_G0:
9745 case elfcpp::R_ARM_ALU_PC_G1_NC:
9746 case elfcpp::R_ARM_ALU_PC_G1:
9747 case elfcpp::R_ARM_ALU_PC_G2:
9748 case elfcpp::R_ARM_ALU_SB_G0_NC:
9749 case elfcpp::R_ARM_ALU_SB_G0:
9750 case elfcpp::R_ARM_ALU_SB_G1_NC:
9751 case elfcpp::R_ARM_ALU_SB_G1:
9752 case elfcpp::R_ARM_ALU_SB_G2:
9753 reloc_status =
9754 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9755 reloc_property->group_index(),
9756 relative_address_base,
9757 thumb_bit, check_overflow);
9758 break;
9759
9760 case elfcpp::R_ARM_LDR_PC_G0:
9761 case elfcpp::R_ARM_LDR_PC_G1:
9762 case elfcpp::R_ARM_LDR_PC_G2:
9763 case elfcpp::R_ARM_LDR_SB_G0:
9764 case elfcpp::R_ARM_LDR_SB_G1:
9765 case elfcpp::R_ARM_LDR_SB_G2:
9766 reloc_status =
9767 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9768 reloc_property->group_index(),
9769 relative_address_base);
9770 break;
9771
9772 case elfcpp::R_ARM_LDRS_PC_G0:
9773 case elfcpp::R_ARM_LDRS_PC_G1:
9774 case elfcpp::R_ARM_LDRS_PC_G2:
9775 case elfcpp::R_ARM_LDRS_SB_G0:
9776 case elfcpp::R_ARM_LDRS_SB_G1:
9777 case elfcpp::R_ARM_LDRS_SB_G2:
9778 reloc_status =
9779 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9780 reloc_property->group_index(),
9781 relative_address_base);
9782 break;
9783
9784 case elfcpp::R_ARM_LDC_PC_G0:
9785 case elfcpp::R_ARM_LDC_PC_G1:
9786 case elfcpp::R_ARM_LDC_PC_G2:
9787 case elfcpp::R_ARM_LDC_SB_G0:
9788 case elfcpp::R_ARM_LDC_SB_G1:
9789 case elfcpp::R_ARM_LDC_SB_G2:
9790 reloc_status =
9791 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9792 reloc_property->group_index(),
9793 relative_address_base);
9794 break;
9795
9796 // These are initial tls relocs, which are expected when
9797 // linking.
9798 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9799 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9800 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9801 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9802 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9803 reloc_status =
9804 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9805 view, address, view_size);
9806 break;
9807
9808 // The known and unknown unsupported and/or deprecated relocations.
9809 case elfcpp::R_ARM_PC24:
9810 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9811 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9812 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9813 default:
9814 // Just silently leave the method. We should get an appropriate error
9815 // message in the scan methods.
9816 break;
9817 }
9818
9819 // Report any errors.
9820 switch (reloc_status)
9821 {
9822 case Arm_relocate_functions::STATUS_OKAY:
9823 break;
9824 case Arm_relocate_functions::STATUS_OVERFLOW:
9825 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9826 _("relocation overflow in %s"),
9827 reloc_property->name().c_str());
9828 break;
9829 case Arm_relocate_functions::STATUS_BAD_RELOC:
9830 gold_error_at_location(
9831 relinfo,
9832 relnum,
9833 rel.get_r_offset(),
9834 _("unexpected opcode while processing relocation %s"),
9835 reloc_property->name().c_str());
9836 break;
9837 default:
9838 gold_unreachable();
9839 }
9840
9841 return true;
9842 }
9843
9844 // Perform a TLS relocation.
9845
9846 template<bool big_endian>
9847 inline typename Arm_relocate_functions<big_endian>::Status
9848 Target_arm<big_endian>::Relocate::relocate_tls(
9849 const Relocate_info<32, big_endian>* relinfo,
9850 Target_arm<big_endian>* target,
9851 size_t relnum,
9852 const elfcpp::Rel<32, big_endian>& rel,
9853 unsigned int r_type,
9854 const Sized_symbol<32>* gsym,
9855 const Symbol_value<32>* psymval,
9856 unsigned char* view,
9857 elfcpp::Elf_types<32>::Elf_Addr address,
9858 section_size_type /*view_size*/ )
9859 {
9860 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9861 typedef Relocate_functions<32, big_endian> RelocFuncs;
9862 Output_segment* tls_segment = relinfo->layout->tls_segment();
9863
9864 const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9865
9866 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9867
9868 const bool is_final = (gsym == NULL
9869 ? !parameters->options().shared()
9870 : gsym->final_value_is_known());
9871 const tls::Tls_optimization optimized_type
9872 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9873 switch (r_type)
9874 {
9875 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9876 {
9877 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9878 unsigned int got_offset;
9879 if (gsym != NULL)
9880 {
9881 gold_assert(gsym->has_got_offset(got_type));
9882 got_offset = gsym->got_offset(got_type) - target->got_size();
9883 }
9884 else
9885 {
9886 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9887 gold_assert(object->local_has_got_offset(r_sym, got_type));
9888 got_offset = (object->local_got_offset(r_sym, got_type)
9889 - target->got_size());
9890 }
9891 if (optimized_type == tls::TLSOPT_NONE)
9892 {
9893 Arm_address got_entry =
9894 target->got_plt_section()->address() + got_offset;
9895
9896 // Relocate the field with the PC relative offset of the pair of
9897 // GOT entries.
9898 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9899 return ArmRelocFuncs::STATUS_OKAY;
9900 }
9901 }
9902 break;
9903
9904 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9905 if (optimized_type == tls::TLSOPT_NONE)
9906 {
9907 // Relocate the field with the offset of the GOT entry for
9908 // the module index.
9909 unsigned int got_offset;
9910 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9911 - target->got_size());
9912 Arm_address got_entry =
9913 target->got_plt_section()->address() + got_offset;
9914
9915 // Relocate the field with the PC relative offset of the pair of
9916 // GOT entries.
9917 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9918 return ArmRelocFuncs::STATUS_OKAY;
9919 }
9920 break;
9921
9922 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9923 RelocFuncs::rel32_unaligned(view, value);
9924 return ArmRelocFuncs::STATUS_OKAY;
9925
9926 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9927 if (optimized_type == tls::TLSOPT_NONE)
9928 {
9929 // Relocate the field with the offset of the GOT entry for
9930 // the tp-relative offset of the symbol.
9931 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9932 unsigned int got_offset;
9933 if (gsym != NULL)
9934 {
9935 gold_assert(gsym->has_got_offset(got_type));
9936 got_offset = gsym->got_offset(got_type);
9937 }
9938 else
9939 {
9940 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9941 gold_assert(object->local_has_got_offset(r_sym, got_type));
9942 got_offset = object->local_got_offset(r_sym, got_type);
9943 }
9944
9945 // All GOT offsets are relative to the end of the GOT.
9946 got_offset -= target->got_size();
9947
9948 Arm_address got_entry =
9949 target->got_plt_section()->address() + got_offset;
9950
9951 // Relocate the field with the PC relative offset of the GOT entry.
9952 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9953 return ArmRelocFuncs::STATUS_OKAY;
9954 }
9955 break;
9956
9957 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9958 // If we're creating a shared library, a dynamic relocation will
9959 // have been created for this location, so do not apply it now.
9960 if (!parameters->options().shared())
9961 {
9962 gold_assert(tls_segment != NULL);
9963
9964 // $tp points to the TCB, which is followed by the TLS, so we
9965 // need to add TCB size to the offset.
9966 Arm_address aligned_tcb_size =
9967 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9968 RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9969
9970 }
9971 return ArmRelocFuncs::STATUS_OKAY;
9972
9973 default:
9974 gold_unreachable();
9975 }
9976
9977 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9978 _("unsupported reloc %u"),
9979 r_type);
9980 return ArmRelocFuncs::STATUS_BAD_RELOC;
9981 }
9982
9983 // Relocate section data.
9984
9985 template<bool big_endian>
9986 void
9987 Target_arm<big_endian>::relocate_section(
9988 const Relocate_info<32, big_endian>* relinfo,
9989 unsigned int sh_type,
9990 const unsigned char* prelocs,
9991 size_t reloc_count,
9992 Output_section* output_section,
9993 bool needs_special_offset_handling,
9994 unsigned char* view,
9995 Arm_address address,
9996 section_size_type view_size,
9997 const Reloc_symbol_changes* reloc_symbol_changes)
9998 {
9999 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
10000 gold_assert(sh_type == elfcpp::SHT_REL);
10001
10002 // See if we are relocating a relaxed input section. If so, the view
10003 // covers the whole output section and we need to adjust accordingly.
10004 if (needs_special_offset_handling)
10005 {
10006 const Output_relaxed_input_section* poris =
10007 output_section->find_relaxed_input_section(relinfo->object,
10008 relinfo->data_shndx);
10009 if (poris != NULL)
10010 {
10011 Arm_address section_address = poris->address();
10012 section_size_type section_size = poris->data_size();
10013
10014 gold_assert((section_address >= address)
10015 && ((section_address + section_size)
10016 <= (address + view_size)));
10017
10018 off_t offset = section_address - address;
10019 view += offset;
10020 address += offset;
10021 view_size = section_size;
10022 }
10023 }
10024
10025 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
10026 Arm_relocate, gold::Default_comdat_behavior>(
10027 relinfo,
10028 this,
10029 prelocs,
10030 reloc_count,
10031 output_section,
10032 needs_special_offset_handling,
10033 view,
10034 address,
10035 view_size,
10036 reloc_symbol_changes);
10037 }
10038
10039 // Return the size of a relocation while scanning during a relocatable
10040 // link.
10041
10042 template<bool big_endian>
10043 unsigned int
10044 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
10045 unsigned int r_type,
10046 Relobj* object)
10047 {
10048 r_type = get_real_reloc_type(r_type);
10049 const Arm_reloc_property* arp =
10050 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10051 if (arp != NULL)
10052 return arp->size();
10053 else
10054 {
10055 std::string reloc_name =
10056 arm_reloc_property_table->reloc_name_in_error_message(r_type);
10057 gold_error(_("%s: unexpected %s in object file"),
10058 object->name().c_str(), reloc_name.c_str());
10059 return 0;
10060 }
10061 }
10062
10063 // Scan the relocs during a relocatable link.
10064
10065 template<bool big_endian>
10066 void
10067 Target_arm<big_endian>::scan_relocatable_relocs(
10068 Symbol_table* symtab,
10069 Layout* layout,
10070 Sized_relobj_file<32, big_endian>* object,
10071 unsigned int data_shndx,
10072 unsigned int sh_type,
10073 const unsigned char* prelocs,
10074 size_t reloc_count,
10075 Output_section* output_section,
10076 bool needs_special_offset_handling,
10077 size_t local_symbol_count,
10078 const unsigned char* plocal_symbols,
10079 Relocatable_relocs* rr)
10080 {
10081 gold_assert(sh_type == elfcpp::SHT_REL);
10082
10083 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
10084 Relocatable_size_for_reloc> Scan_relocatable_relocs;
10085
10086 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
10087 Scan_relocatable_relocs>(
10088 symtab,
10089 layout,
10090 object,
10091 data_shndx,
10092 prelocs,
10093 reloc_count,
10094 output_section,
10095 needs_special_offset_handling,
10096 local_symbol_count,
10097 plocal_symbols,
10098 rr);
10099 }
10100
10101 // Emit relocations for a section.
10102
10103 template<bool big_endian>
10104 void
10105 Target_arm<big_endian>::relocate_relocs(
10106 const Relocate_info<32, big_endian>* relinfo,
10107 unsigned int sh_type,
10108 const unsigned char* prelocs,
10109 size_t reloc_count,
10110 Output_section* output_section,
10111 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10112 const Relocatable_relocs* rr,
10113 unsigned char* view,
10114 Arm_address view_address,
10115 section_size_type view_size,
10116 unsigned char* reloc_view,
10117 section_size_type reloc_view_size)
10118 {
10119 gold_assert(sh_type == elfcpp::SHT_REL);
10120
10121 gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
10122 relinfo,
10123 prelocs,
10124 reloc_count,
10125 output_section,
10126 offset_in_output_section,
10127 rr,
10128 view,
10129 view_address,
10130 view_size,
10131 reloc_view,
10132 reloc_view_size);
10133 }
10134
10135 // Perform target-specific processing in a relocatable link. This is
10136 // only used if we use the relocation strategy RELOC_SPECIAL.
10137
10138 template<bool big_endian>
10139 void
10140 Target_arm<big_endian>::relocate_special_relocatable(
10141 const Relocate_info<32, big_endian>* relinfo,
10142 unsigned int sh_type,
10143 const unsigned char* preloc_in,
10144 size_t relnum,
10145 Output_section* output_section,
10146 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
10147 unsigned char* view,
10148 elfcpp::Elf_types<32>::Elf_Addr view_address,
10149 section_size_type,
10150 unsigned char* preloc_out)
10151 {
10152 // We can only handle REL type relocation sections.
10153 gold_assert(sh_type == elfcpp::SHT_REL);
10154
10155 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
10156 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
10157 Reltype_write;
10158 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
10159
10160 const Arm_relobj<big_endian>* object =
10161 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10162 const unsigned int local_count = object->local_symbol_count();
10163
10164 Reltype reloc(preloc_in);
10165 Reltype_write reloc_write(preloc_out);
10166
10167 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10168 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10169 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10170
10171 const Arm_reloc_property* arp =
10172 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10173 gold_assert(arp != NULL);
10174
10175 // Get the new symbol index.
10176 // We only use RELOC_SPECIAL strategy in local relocations.
10177 gold_assert(r_sym < local_count);
10178
10179 // We are adjusting a section symbol. We need to find
10180 // the symbol table index of the section symbol for
10181 // the output section corresponding to input section
10182 // in which this symbol is defined.
10183 bool is_ordinary;
10184 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
10185 gold_assert(is_ordinary);
10186 Output_section* os = object->output_section(shndx);
10187 gold_assert(os != NULL);
10188 gold_assert(os->needs_symtab_index());
10189 unsigned int new_symndx = os->symtab_index();
10190
10191 // Get the new offset--the location in the output section where
10192 // this relocation should be applied.
10193
10194 Arm_address offset = reloc.get_r_offset();
10195 Arm_address new_offset;
10196 if (offset_in_output_section != invalid_address)
10197 new_offset = offset + offset_in_output_section;
10198 else
10199 {
10200 section_offset_type sot_offset =
10201 convert_types<section_offset_type, Arm_address>(offset);
10202 section_offset_type new_sot_offset =
10203 output_section->output_offset(object, relinfo->data_shndx,
10204 sot_offset);
10205 gold_assert(new_sot_offset != -1);
10206 new_offset = new_sot_offset;
10207 }
10208
10209 // In an object file, r_offset is an offset within the section.
10210 // In an executable or dynamic object, generated by
10211 // --emit-relocs, r_offset is an absolute address.
10212 if (!parameters->options().relocatable())
10213 {
10214 new_offset += view_address;
10215 if (offset_in_output_section != invalid_address)
10216 new_offset -= offset_in_output_section;
10217 }
10218
10219 reloc_write.put_r_offset(new_offset);
10220 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
10221
10222 // Handle the reloc addend.
10223 // The relocation uses a section symbol in the input file.
10224 // We are adjusting it to use a section symbol in the output
10225 // file. The input section symbol refers to some address in
10226 // the input section. We need the relocation in the output
10227 // file to refer to that same address. This adjustment to
10228 // the addend is the same calculation we use for a simple
10229 // absolute relocation for the input section symbol.
10230
10231 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
10232
10233 // Handle THUMB bit.
10234 Symbol_value<32> symval;
10235 Arm_address thumb_bit =
10236 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
10237 if (thumb_bit != 0
10238 && arp->uses_thumb_bit()
10239 && ((psymval->value(object, 0) & 1) != 0))
10240 {
10241 Arm_address stripped_value =
10242 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
10243 symval.set_output_value(stripped_value);
10244 psymval = &symval;
10245 }
10246
10247 unsigned char* paddend = view + offset;
10248 typename Arm_relocate_functions<big_endian>::Status reloc_status =
10249 Arm_relocate_functions<big_endian>::STATUS_OKAY;
10250 switch (r_type)
10251 {
10252 case elfcpp::R_ARM_ABS8:
10253 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
10254 psymval);
10255 break;
10256
10257 case elfcpp::R_ARM_ABS12:
10258 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
10259 psymval);
10260 break;
10261
10262 case elfcpp::R_ARM_ABS16:
10263 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
10264 psymval);
10265 break;
10266
10267 case elfcpp::R_ARM_THM_ABS5:
10268 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
10269 object,
10270 psymval);
10271 break;
10272
10273 case elfcpp::R_ARM_MOVW_ABS_NC:
10274 case elfcpp::R_ARM_MOVW_PREL_NC:
10275 case elfcpp::R_ARM_MOVW_BREL_NC:
10276 case elfcpp::R_ARM_MOVW_BREL:
10277 reloc_status = Arm_relocate_functions<big_endian>::movw(
10278 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10279 break;
10280
10281 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
10282 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
10283 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
10284 case elfcpp::R_ARM_THM_MOVW_BREL:
10285 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
10286 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
10287 break;
10288
10289 case elfcpp::R_ARM_THM_CALL:
10290 case elfcpp::R_ARM_THM_XPC22:
10291 case elfcpp::R_ARM_THM_JUMP24:
10292 reloc_status =
10293 Arm_relocate_functions<big_endian>::thumb_branch_common(
10294 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10295 false);
10296 break;
10297
10298 case elfcpp::R_ARM_PLT32:
10299 case elfcpp::R_ARM_CALL:
10300 case elfcpp::R_ARM_JUMP24:
10301 case elfcpp::R_ARM_XPC25:
10302 reloc_status =
10303 Arm_relocate_functions<big_endian>::arm_branch_common(
10304 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
10305 false);
10306 break;
10307
10308 case elfcpp::R_ARM_THM_JUMP19:
10309 reloc_status =
10310 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
10311 psymval, 0, thumb_bit);
10312 break;
10313
10314 case elfcpp::R_ARM_THM_JUMP6:
10315 reloc_status =
10316 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
10317 0);
10318 break;
10319
10320 case elfcpp::R_ARM_THM_JUMP8:
10321 reloc_status =
10322 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
10323 0);
10324 break;
10325
10326 case elfcpp::R_ARM_THM_JUMP11:
10327 reloc_status =
10328 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
10329 0);
10330 break;
10331
10332 case elfcpp::R_ARM_PREL31:
10333 reloc_status =
10334 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
10335 thumb_bit);
10336 break;
10337
10338 case elfcpp::R_ARM_THM_PC8:
10339 reloc_status =
10340 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
10341 0);
10342 break;
10343
10344 case elfcpp::R_ARM_THM_PC12:
10345 reloc_status =
10346 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
10347 0);
10348 break;
10349
10350 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
10351 reloc_status =
10352 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
10353 0, thumb_bit);
10354 break;
10355
10356 // These relocation truncate relocation results so we cannot handle them
10357 // in a relocatable link.
10358 case elfcpp::R_ARM_MOVT_ABS:
10359 case elfcpp::R_ARM_THM_MOVT_ABS:
10360 case elfcpp::R_ARM_MOVT_PREL:
10361 case elfcpp::R_ARM_MOVT_BREL:
10362 case elfcpp::R_ARM_THM_MOVT_PREL:
10363 case elfcpp::R_ARM_THM_MOVT_BREL:
10364 case elfcpp::R_ARM_ALU_PC_G0_NC:
10365 case elfcpp::R_ARM_ALU_PC_G0:
10366 case elfcpp::R_ARM_ALU_PC_G1_NC:
10367 case elfcpp::R_ARM_ALU_PC_G1:
10368 case elfcpp::R_ARM_ALU_PC_G2:
10369 case elfcpp::R_ARM_ALU_SB_G0_NC:
10370 case elfcpp::R_ARM_ALU_SB_G0:
10371 case elfcpp::R_ARM_ALU_SB_G1_NC:
10372 case elfcpp::R_ARM_ALU_SB_G1:
10373 case elfcpp::R_ARM_ALU_SB_G2:
10374 case elfcpp::R_ARM_LDR_PC_G0:
10375 case elfcpp::R_ARM_LDR_PC_G1:
10376 case elfcpp::R_ARM_LDR_PC_G2:
10377 case elfcpp::R_ARM_LDR_SB_G0:
10378 case elfcpp::R_ARM_LDR_SB_G1:
10379 case elfcpp::R_ARM_LDR_SB_G2:
10380 case elfcpp::R_ARM_LDRS_PC_G0:
10381 case elfcpp::R_ARM_LDRS_PC_G1:
10382 case elfcpp::R_ARM_LDRS_PC_G2:
10383 case elfcpp::R_ARM_LDRS_SB_G0:
10384 case elfcpp::R_ARM_LDRS_SB_G1:
10385 case elfcpp::R_ARM_LDRS_SB_G2:
10386 case elfcpp::R_ARM_LDC_PC_G0:
10387 case elfcpp::R_ARM_LDC_PC_G1:
10388 case elfcpp::R_ARM_LDC_PC_G2:
10389 case elfcpp::R_ARM_LDC_SB_G0:
10390 case elfcpp::R_ARM_LDC_SB_G1:
10391 case elfcpp::R_ARM_LDC_SB_G2:
10392 gold_error(_("cannot handle %s in a relocatable link"),
10393 arp->name().c_str());
10394 break;
10395
10396 default:
10397 gold_unreachable();
10398 }
10399
10400 // Report any errors.
10401 switch (reloc_status)
10402 {
10403 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
10404 break;
10405 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
10406 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10407 _("relocation overflow in %s"),
10408 arp->name().c_str());
10409 break;
10410 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
10411 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
10412 _("unexpected opcode while processing relocation %s"),
10413 arp->name().c_str());
10414 break;
10415 default:
10416 gold_unreachable();
10417 }
10418 }
10419
10420 // Return the value to use for a dynamic symbol which requires special
10421 // treatment. This is how we support equality comparisons of function
10422 // pointers across shared library boundaries, as described in the
10423 // processor specific ABI supplement.
10424
10425 template<bool big_endian>
10426 uint64_t
10427 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
10428 {
10429 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
10430 return this->plt_address_for_global(gsym);
10431 }
10432
10433 // Map platform-specific relocs to real relocs
10434 //
10435 template<bool big_endian>
10436 unsigned int
10437 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
10438 {
10439 switch (r_type)
10440 {
10441 case elfcpp::R_ARM_TARGET1:
10442 // This is either R_ARM_ABS32 or R_ARM_REL32;
10443 return elfcpp::R_ARM_ABS32;
10444
10445 case elfcpp::R_ARM_TARGET2:
10446 // This can be any reloc type but usually is R_ARM_GOT_PREL
10447 return elfcpp::R_ARM_GOT_PREL;
10448
10449 default:
10450 return r_type;
10451 }
10452 }
10453
10454 // Whether if two EABI versions V1 and V2 are compatible.
10455
10456 template<bool big_endian>
10457 bool
10458 Target_arm<big_endian>::are_eabi_versions_compatible(
10459 elfcpp::Elf_Word v1,
10460 elfcpp::Elf_Word v2)
10461 {
10462 // v4 and v5 are the same spec before and after it was released,
10463 // so allow mixing them.
10464 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
10465 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
10466 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
10467 return true;
10468
10469 return v1 == v2;
10470 }
10471
10472 // Combine FLAGS from an input object called NAME and the processor-specific
10473 // flags in the ELF header of the output. Much of this is adapted from the
10474 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
10475 // in bfd/elf32-arm.c.
10476
10477 template<bool big_endian>
10478 void
10479 Target_arm<big_endian>::merge_processor_specific_flags(
10480 const std::string& name,
10481 elfcpp::Elf_Word flags)
10482 {
10483 if (this->are_processor_specific_flags_set())
10484 {
10485 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
10486
10487 // Nothing to merge if flags equal to those in output.
10488 if (flags == out_flags)
10489 return;
10490
10491 // Complain about various flag mismatches.
10492 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10493 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10494 if (!this->are_eabi_versions_compatible(version1, version2)
10495 && parameters->options().warn_mismatch())
10496 gold_error(_("Source object %s has EABI version %d but output has "
10497 "EABI version %d."),
10498 name.c_str(),
10499 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10500 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10501 }
10502 else
10503 {
10504 // If the input is the default architecture and had the default
10505 // flags then do not bother setting the flags for the output
10506 // architecture, instead allow future merges to do this. If no
10507 // future merges ever set these flags then they will retain their
10508 // uninitialised values, which surprise surprise, correspond
10509 // to the default values.
10510 if (flags == 0)
10511 return;
10512
10513 // This is the first time, just copy the flags.
10514 // We only copy the EABI version for now.
10515 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10516 }
10517 }
10518
10519 // Adjust ELF file header.
10520 template<bool big_endian>
10521 void
10522 Target_arm<big_endian>::do_adjust_elf_header(
10523 unsigned char* view,
10524 int len)
10525 {
10526 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10527
10528 elfcpp::Ehdr<32, big_endian> ehdr(view);
10529 elfcpp::Elf_Word flags = this->processor_specific_flags();
10530 unsigned char e_ident[elfcpp::EI_NIDENT];
10531 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10532
10533 if (elfcpp::arm_eabi_version(flags)
10534 == elfcpp::EF_ARM_EABI_UNKNOWN)
10535 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10536 else
10537 e_ident[elfcpp::EI_OSABI] = 0;
10538 e_ident[elfcpp::EI_ABIVERSION] = 0;
10539
10540 // FIXME: Do EF_ARM_BE8 adjustment.
10541
10542 // If we're working in EABI_VER5, set the hard/soft float ABI flags
10543 // as appropriate.
10544 if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10545 {
10546 elfcpp::Elf_Half type = ehdr.get_e_type();
10547 if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10548 {
10549 Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10550 if (attr->int_value() == elfcpp::AEABI_VFP_args_vfp)
10551 flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10552 else
10553 flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10554 this->set_processor_specific_flags(flags);
10555 }
10556 }
10557 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10558 oehdr.put_e_ident(e_ident);
10559 oehdr.put_e_flags(this->processor_specific_flags());
10560 }
10561
10562 // do_make_elf_object to override the same function in the base class.
10563 // We need to use a target-specific sub-class of
10564 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10565 // Hence we need to have our own ELF object creation.
10566
10567 template<bool big_endian>
10568 Object*
10569 Target_arm<big_endian>::do_make_elf_object(
10570 const std::string& name,
10571 Input_file* input_file,
10572 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10573 {
10574 int et = ehdr.get_e_type();
10575 // ET_EXEC files are valid input for --just-symbols/-R,
10576 // and we treat them as relocatable objects.
10577 if (et == elfcpp::ET_REL
10578 || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10579 {
10580 Arm_relobj<big_endian>* obj =
10581 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10582 obj->setup();
10583 return obj;
10584 }
10585 else if (et == elfcpp::ET_DYN)
10586 {
10587 Sized_dynobj<32, big_endian>* obj =
10588 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10589 obj->setup();
10590 return obj;
10591 }
10592 else
10593 {
10594 gold_error(_("%s: unsupported ELF file type %d"),
10595 name.c_str(), et);
10596 return NULL;
10597 }
10598 }
10599
10600 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10601 // Returns -1 if no architecture could be read.
10602 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10603
10604 template<bool big_endian>
10605 int
10606 Target_arm<big_endian>::get_secondary_compatible_arch(
10607 const Attributes_section_data* pasd)
10608 {
10609 const Object_attribute* known_attributes =
10610 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10611
10612 // Note: the tag and its argument below are uleb128 values, though
10613 // currently-defined values fit in one byte for each.
10614 const std::string& sv =
10615 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10616 if (sv.size() == 2
10617 && sv.data()[0] == elfcpp::Tag_CPU_arch
10618 && (sv.data()[1] & 128) != 128)
10619 return sv.data()[1];
10620
10621 // This tag is "safely ignorable", so don't complain if it looks funny.
10622 return -1;
10623 }
10624
10625 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10626 // The tag is removed if ARCH is -1.
10627 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10628
10629 template<bool big_endian>
10630 void
10631 Target_arm<big_endian>::set_secondary_compatible_arch(
10632 Attributes_section_data* pasd,
10633 int arch)
10634 {
10635 Object_attribute* known_attributes =
10636 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10637
10638 if (arch == -1)
10639 {
10640 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10641 return;
10642 }
10643
10644 // Note: the tag and its argument below are uleb128 values, though
10645 // currently-defined values fit in one byte for each.
10646 char sv[3];
10647 sv[0] = elfcpp::Tag_CPU_arch;
10648 gold_assert(arch != 0);
10649 sv[1] = arch;
10650 sv[2] = '\0';
10651
10652 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10653 }
10654
10655 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10656 // into account.
10657 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10658
10659 template<bool big_endian>
10660 int
10661 Target_arm<big_endian>::tag_cpu_arch_combine(
10662 const char* name,
10663 int oldtag,
10664 int* secondary_compat_out,
10665 int newtag,
10666 int secondary_compat)
10667 {
10668 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10669 static const int v6t2[] =
10670 {
10671 T(V6T2), // PRE_V4.
10672 T(V6T2), // V4.
10673 T(V6T2), // V4T.
10674 T(V6T2), // V5T.
10675 T(V6T2), // V5TE.
10676 T(V6T2), // V5TEJ.
10677 T(V6T2), // V6.
10678 T(V7), // V6KZ.
10679 T(V6T2) // V6T2.
10680 };
10681 static const int v6k[] =
10682 {
10683 T(V6K), // PRE_V4.
10684 T(V6K), // V4.
10685 T(V6K), // V4T.
10686 T(V6K), // V5T.
10687 T(V6K), // V5TE.
10688 T(V6K), // V5TEJ.
10689 T(V6K), // V6.
10690 T(V6KZ), // V6KZ.
10691 T(V7), // V6T2.
10692 T(V6K) // V6K.
10693 };
10694 static const int v7[] =
10695 {
10696 T(V7), // PRE_V4.
10697 T(V7), // V4.
10698 T(V7), // V4T.
10699 T(V7), // V5T.
10700 T(V7), // V5TE.
10701 T(V7), // V5TEJ.
10702 T(V7), // V6.
10703 T(V7), // V6KZ.
10704 T(V7), // V6T2.
10705 T(V7), // V6K.
10706 T(V7) // V7.
10707 };
10708 static const int v6_m[] =
10709 {
10710 -1, // PRE_V4.
10711 -1, // V4.
10712 T(V6K), // V4T.
10713 T(V6K), // V5T.
10714 T(V6K), // V5TE.
10715 T(V6K), // V5TEJ.
10716 T(V6K), // V6.
10717 T(V6KZ), // V6KZ.
10718 T(V7), // V6T2.
10719 T(V6K), // V6K.
10720 T(V7), // V7.
10721 T(V6_M) // V6_M.
10722 };
10723 static const int v6s_m[] =
10724 {
10725 -1, // PRE_V4.
10726 -1, // V4.
10727 T(V6K), // V4T.
10728 T(V6K), // V5T.
10729 T(V6K), // V5TE.
10730 T(V6K), // V5TEJ.
10731 T(V6K), // V6.
10732 T(V6KZ), // V6KZ.
10733 T(V7), // V6T2.
10734 T(V6K), // V6K.
10735 T(V7), // V7.
10736 T(V6S_M), // V6_M.
10737 T(V6S_M) // V6S_M.
10738 };
10739 static const int v7e_m[] =
10740 {
10741 -1, // PRE_V4.
10742 -1, // V4.
10743 T(V7E_M), // V4T.
10744 T(V7E_M), // V5T.
10745 T(V7E_M), // V5TE.
10746 T(V7E_M), // V5TEJ.
10747 T(V7E_M), // V6.
10748 T(V7E_M), // V6KZ.
10749 T(V7E_M), // V6T2.
10750 T(V7E_M), // V6K.
10751 T(V7E_M), // V7.
10752 T(V7E_M), // V6_M.
10753 T(V7E_M), // V6S_M.
10754 T(V7E_M) // V7E_M.
10755 };
10756 static const int v8[] =
10757 {
10758 T(V8), // PRE_V4.
10759 T(V8), // V4.
10760 T(V8), // V4T.
10761 T(V8), // V5T.
10762 T(V8), // V5TE.
10763 T(V8), // V5TEJ.
10764 T(V8), // V6.
10765 T(V8), // V6KZ.
10766 T(V8), // V6T2.
10767 T(V8), // V6K.
10768 T(V8), // V7.
10769 T(V8), // V6_M.
10770 T(V8), // V6S_M.
10771 T(V8), // V7E_M.
10772 T(V8) // V8.
10773 };
10774 static const int v4t_plus_v6_m[] =
10775 {
10776 -1, // PRE_V4.
10777 -1, // V4.
10778 T(V4T), // V4T.
10779 T(V5T), // V5T.
10780 T(V5TE), // V5TE.
10781 T(V5TEJ), // V5TEJ.
10782 T(V6), // V6.
10783 T(V6KZ), // V6KZ.
10784 T(V6T2), // V6T2.
10785 T(V6K), // V6K.
10786 T(V7), // V7.
10787 T(V6_M), // V6_M.
10788 T(V6S_M), // V6S_M.
10789 T(V7E_M), // V7E_M.
10790 T(V8), // V8.
10791 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10792 };
10793 static const int* comb[] =
10794 {
10795 v6t2,
10796 v6k,
10797 v7,
10798 v6_m,
10799 v6s_m,
10800 v7e_m,
10801 v8,
10802 // Pseudo-architecture.
10803 v4t_plus_v6_m
10804 };
10805
10806 // Check we've not got a higher architecture than we know about.
10807
10808 if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10809 {
10810 gold_error(_("%s: unknown CPU architecture"), name);
10811 return -1;
10812 }
10813
10814 // Override old tag if we have a Tag_also_compatible_with on the output.
10815
10816 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10817 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10818 oldtag = T(V4T_PLUS_V6_M);
10819
10820 // And override the new tag if we have a Tag_also_compatible_with on the
10821 // input.
10822
10823 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10824 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10825 newtag = T(V4T_PLUS_V6_M);
10826
10827 // Architectures before V6KZ add features monotonically.
10828 int tagh = std::max(oldtag, newtag);
10829 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10830 return tagh;
10831
10832 int tagl = std::min(oldtag, newtag);
10833 int result = comb[tagh - T(V6T2)][tagl];
10834
10835 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10836 // as the canonical version.
10837 if (result == T(V4T_PLUS_V6_M))
10838 {
10839 result = T(V4T);
10840 *secondary_compat_out = T(V6_M);
10841 }
10842 else
10843 *secondary_compat_out = -1;
10844
10845 if (result == -1)
10846 {
10847 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10848 name, oldtag, newtag);
10849 return -1;
10850 }
10851
10852 return result;
10853 #undef T
10854 }
10855
10856 // Helper to print AEABI enum tag value.
10857
10858 template<bool big_endian>
10859 std::string
10860 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10861 {
10862 static const char* aeabi_enum_names[] =
10863 { "", "variable-size", "32-bit", "" };
10864 const size_t aeabi_enum_names_size =
10865 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10866
10867 if (value < aeabi_enum_names_size)
10868 return std::string(aeabi_enum_names[value]);
10869 else
10870 {
10871 char buffer[100];
10872 sprintf(buffer, "<unknown value %u>", value);
10873 return std::string(buffer);
10874 }
10875 }
10876
10877 // Return the string value to store in TAG_CPU_name.
10878
10879 template<bool big_endian>
10880 std::string
10881 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10882 {
10883 static const char* name_table[] = {
10884 // These aren't real CPU names, but we can't guess
10885 // that from the architecture version alone.
10886 "Pre v4",
10887 "ARM v4",
10888 "ARM v4T",
10889 "ARM v5T",
10890 "ARM v5TE",
10891 "ARM v5TEJ",
10892 "ARM v6",
10893 "ARM v6KZ",
10894 "ARM v6T2",
10895 "ARM v6K",
10896 "ARM v7",
10897 "ARM v6-M",
10898 "ARM v6S-M",
10899 "ARM v7E-M",
10900 "ARM v8"
10901 };
10902 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10903
10904 if (value < name_table_size)
10905 return std::string(name_table[value]);
10906 else
10907 {
10908 char buffer[100];
10909 sprintf(buffer, "<unknown CPU value %u>", value);
10910 return std::string(buffer);
10911 }
10912 }
10913
10914 // Query attributes object to see if integer divide instructions may be
10915 // present in an object.
10916
10917 template<bool big_endian>
10918 bool
10919 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10920 const Object_attribute* div_attr)
10921 {
10922 switch (div_attr->int_value())
10923 {
10924 case 0:
10925 // Integer divide allowed if instruction contained in
10926 // archetecture.
10927 if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10928 return true;
10929 else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10930 return true;
10931 else
10932 return false;
10933
10934 case 1:
10935 // Integer divide explicitly prohibited.
10936 return false;
10937
10938 default:
10939 // Unrecognised case - treat as allowing divide everywhere.
10940 case 2:
10941 // Integer divide allowed in ARM state.
10942 return true;
10943 }
10944 }
10945
10946 // Query attributes object to see if integer divide instructions are
10947 // forbidden to be in the object. This is not the inverse of
10948 // attributes_accept_div.
10949
10950 template<bool big_endian>
10951 bool
10952 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10953 {
10954 return div_attr->int_value() == 1;
10955 }
10956
10957 // Merge object attributes from input file called NAME with those of the
10958 // output. The input object attributes are in the object pointed by PASD.
10959
10960 template<bool big_endian>
10961 void
10962 Target_arm<big_endian>::merge_object_attributes(
10963 const char* name,
10964 const Attributes_section_data* pasd)
10965 {
10966 // Return if there is no attributes section data.
10967 if (pasd == NULL)
10968 return;
10969
10970 // If output has no object attributes, just copy.
10971 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10972 if (this->attributes_section_data_ == NULL)
10973 {
10974 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10975 Object_attribute* out_attr =
10976 this->attributes_section_data_->known_attributes(vendor);
10977
10978 // We do not output objects with Tag_MPextension_use_legacy - we move
10979 // the attribute's value to Tag_MPextension_use. */
10980 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10981 {
10982 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10983 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10984 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10985 {
10986 gold_error(_("%s has both the current and legacy "
10987 "Tag_MPextension_use attributes"),
10988 name);
10989 }
10990
10991 out_attr[elfcpp::Tag_MPextension_use] =
10992 out_attr[elfcpp::Tag_MPextension_use_legacy];
10993 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10994 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10995 }
10996
10997 return;
10998 }
10999
11000 const Object_attribute* in_attr = pasd->known_attributes(vendor);
11001 Object_attribute* out_attr =
11002 this->attributes_section_data_->known_attributes(vendor);
11003
11004 // This needs to happen before Tag_ABI_FP_number_model is merged. */
11005 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11006 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
11007 {
11008 // Ignore mismatches if the object doesn't use floating point. */
11009 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11010 == elfcpp::AEABI_FP_number_model_none
11011 || (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11012 != elfcpp::AEABI_FP_number_model_none
11013 && out_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11014 == elfcpp::AEABI_VFP_args_compatible))
11015 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
11016 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
11017 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
11018 != elfcpp::AEABI_FP_number_model_none
11019 && in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
11020 != elfcpp::AEABI_VFP_args_compatible
11021 && parameters->options().warn_mismatch())
11022 gold_error(_("%s uses VFP register arguments, output does not"),
11023 name);
11024 }
11025
11026 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
11027 {
11028 // Merge this attribute with existing attributes.
11029 switch (i)
11030 {
11031 case elfcpp::Tag_CPU_raw_name:
11032 case elfcpp::Tag_CPU_name:
11033 // These are merged after Tag_CPU_arch.
11034 break;
11035
11036 case elfcpp::Tag_ABI_optimization_goals:
11037 case elfcpp::Tag_ABI_FP_optimization_goals:
11038 // Use the first value seen.
11039 break;
11040
11041 case elfcpp::Tag_CPU_arch:
11042 {
11043 unsigned int saved_out_attr = out_attr->int_value();
11044 // Merge Tag_CPU_arch and Tag_also_compatible_with.
11045 int secondary_compat =
11046 this->get_secondary_compatible_arch(pasd);
11047 int secondary_compat_out =
11048 this->get_secondary_compatible_arch(
11049 this->attributes_section_data_);
11050 out_attr[i].set_int_value(
11051 tag_cpu_arch_combine(name, out_attr[i].int_value(),
11052 &secondary_compat_out,
11053 in_attr[i].int_value(),
11054 secondary_compat));
11055 this->set_secondary_compatible_arch(this->attributes_section_data_,
11056 secondary_compat_out);
11057
11058 // Merge Tag_CPU_name and Tag_CPU_raw_name.
11059 if (out_attr[i].int_value() == saved_out_attr)
11060 ; // Leave the names alone.
11061 else if (out_attr[i].int_value() == in_attr[i].int_value())
11062 {
11063 // The output architecture has been changed to match the
11064 // input architecture. Use the input names.
11065 out_attr[elfcpp::Tag_CPU_name].set_string_value(
11066 in_attr[elfcpp::Tag_CPU_name].string_value());
11067 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
11068 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
11069 }
11070 else
11071 {
11072 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
11073 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
11074 }
11075
11076 // If we still don't have a value for Tag_CPU_name,
11077 // make one up now. Tag_CPU_raw_name remains blank.
11078 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
11079 {
11080 const std::string cpu_name =
11081 this->tag_cpu_name_value(out_attr[i].int_value());
11082 // FIXME: If we see an unknown CPU, this will be set
11083 // to "<unknown CPU n>", where n is the attribute value.
11084 // This is different from BFD, which leaves the name alone.
11085 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
11086 }
11087 }
11088 break;
11089
11090 case elfcpp::Tag_ARM_ISA_use:
11091 case elfcpp::Tag_THUMB_ISA_use:
11092 case elfcpp::Tag_WMMX_arch:
11093 case elfcpp::Tag_Advanced_SIMD_arch:
11094 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
11095 case elfcpp::Tag_ABI_FP_rounding:
11096 case elfcpp::Tag_ABI_FP_exceptions:
11097 case elfcpp::Tag_ABI_FP_user_exceptions:
11098 case elfcpp::Tag_ABI_FP_number_model:
11099 case elfcpp::Tag_VFP_HP_extension:
11100 case elfcpp::Tag_CPU_unaligned_access:
11101 case elfcpp::Tag_T2EE_use:
11102 case elfcpp::Tag_Virtualization_use:
11103 case elfcpp::Tag_MPextension_use:
11104 // Use the largest value specified.
11105 if (in_attr[i].int_value() > out_attr[i].int_value())
11106 out_attr[i].set_int_value(in_attr[i].int_value());
11107 break;
11108
11109 case elfcpp::Tag_ABI_align8_preserved:
11110 case elfcpp::Tag_ABI_PCS_RO_data:
11111 // Use the smallest value specified.
11112 if (in_attr[i].int_value() < out_attr[i].int_value())
11113 out_attr[i].set_int_value(in_attr[i].int_value());
11114 break;
11115
11116 case elfcpp::Tag_ABI_align8_needed:
11117 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
11118 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
11119 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
11120 == 0)))
11121 {
11122 // This error message should be enabled once all non-conforming
11123 // binaries in the toolchain have had the attributes set
11124 // properly.
11125 // gold_error(_("output 8-byte data alignment conflicts with %s"),
11126 // name);
11127 }
11128 // Fall through.
11129 case elfcpp::Tag_ABI_FP_denormal:
11130 case elfcpp::Tag_ABI_PCS_GOT_use:
11131 {
11132 // These tags have 0 = don't care, 1 = strong requirement,
11133 // 2 = weak requirement.
11134 static const int order_021[3] = {0, 2, 1};
11135
11136 // Use the "greatest" from the sequence 0, 2, 1, or the largest
11137 // value if greater than 2 (for future-proofing).
11138 if ((in_attr[i].int_value() > 2
11139 && in_attr[i].int_value() > out_attr[i].int_value())
11140 || (in_attr[i].int_value() <= 2
11141 && out_attr[i].int_value() <= 2
11142 && (order_021[in_attr[i].int_value()]
11143 > order_021[out_attr[i].int_value()])))
11144 out_attr[i].set_int_value(in_attr[i].int_value());
11145 }
11146 break;
11147
11148 case elfcpp::Tag_CPU_arch_profile:
11149 if (out_attr[i].int_value() != in_attr[i].int_value())
11150 {
11151 // 0 will merge with anything.
11152 // 'A' and 'S' merge to 'A'.
11153 // 'R' and 'S' merge to 'R'.
11154 // 'M' and 'A|R|S' is an error.
11155 if (out_attr[i].int_value() == 0
11156 || (out_attr[i].int_value() == 'S'
11157 && (in_attr[i].int_value() == 'A'
11158 || in_attr[i].int_value() == 'R')))
11159 out_attr[i].set_int_value(in_attr[i].int_value());
11160 else if (in_attr[i].int_value() == 0
11161 || (in_attr[i].int_value() == 'S'
11162 && (out_attr[i].int_value() == 'A'
11163 || out_attr[i].int_value() == 'R')))
11164 ; // Do nothing.
11165 else if (parameters->options().warn_mismatch())
11166 {
11167 gold_error
11168 (_("conflicting architecture profiles %c/%c"),
11169 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
11170 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
11171 }
11172 }
11173 break;
11174 case elfcpp::Tag_VFP_arch:
11175 {
11176 static const struct
11177 {
11178 int ver;
11179 int regs;
11180 } vfp_versions[7] =
11181 {
11182 {0, 0},
11183 {1, 16},
11184 {2, 16},
11185 {3, 32},
11186 {3, 16},
11187 {4, 32},
11188 {4, 16}
11189 };
11190
11191 // Values greater than 6 aren't defined, so just pick the
11192 // biggest.
11193 if (in_attr[i].int_value() > 6
11194 && in_attr[i].int_value() > out_attr[i].int_value())
11195 {
11196 *out_attr = *in_attr;
11197 break;
11198 }
11199 // The output uses the superset of input features
11200 // (ISA version) and registers.
11201 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
11202 vfp_versions[out_attr[i].int_value()].ver);
11203 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
11204 vfp_versions[out_attr[i].int_value()].regs);
11205 // This assumes all possible supersets are also a valid
11206 // options.
11207 int newval;
11208 for (newval = 6; newval > 0; newval--)
11209 {
11210 if (regs == vfp_versions[newval].regs
11211 && ver == vfp_versions[newval].ver)
11212 break;
11213 }
11214 out_attr[i].set_int_value(newval);
11215 }
11216 break;
11217 case elfcpp::Tag_PCS_config:
11218 if (out_attr[i].int_value() == 0)
11219 out_attr[i].set_int_value(in_attr[i].int_value());
11220 else if (in_attr[i].int_value() != 0
11221 && out_attr[i].int_value() != 0
11222 && parameters->options().warn_mismatch())
11223 {
11224 // It's sometimes ok to mix different configs, so this is only
11225 // a warning.
11226 gold_warning(_("%s: conflicting platform configuration"), name);
11227 }
11228 break;
11229 case elfcpp::Tag_ABI_PCS_R9_use:
11230 if (in_attr[i].int_value() != out_attr[i].int_value()
11231 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
11232 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
11233 && parameters->options().warn_mismatch())
11234 {
11235 gold_error(_("%s: conflicting use of R9"), name);
11236 }
11237 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
11238 out_attr[i].set_int_value(in_attr[i].int_value());
11239 break;
11240 case elfcpp::Tag_ABI_PCS_RW_data:
11241 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
11242 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11243 != elfcpp::AEABI_R9_SB)
11244 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
11245 != elfcpp::AEABI_R9_unused)
11246 && parameters->options().warn_mismatch())
11247 {
11248 gold_error(_("%s: SB relative addressing conflicts with use "
11249 "of R9"),
11250 name);
11251 }
11252 // Use the smallest value specified.
11253 if (in_attr[i].int_value() < out_attr[i].int_value())
11254 out_attr[i].set_int_value(in_attr[i].int_value());
11255 break;
11256 case elfcpp::Tag_ABI_PCS_wchar_t:
11257 if (out_attr[i].int_value()
11258 && in_attr[i].int_value()
11259 && out_attr[i].int_value() != in_attr[i].int_value()
11260 && parameters->options().warn_mismatch()
11261 && parameters->options().wchar_size_warning())
11262 {
11263 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
11264 "use %u-byte wchar_t; use of wchar_t values "
11265 "across objects may fail"),
11266 name, in_attr[i].int_value(),
11267 out_attr[i].int_value());
11268 }
11269 else if (in_attr[i].int_value() && !out_attr[i].int_value())
11270 out_attr[i].set_int_value(in_attr[i].int_value());
11271 break;
11272 case elfcpp::Tag_ABI_enum_size:
11273 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
11274 {
11275 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
11276 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
11277 {
11278 // The existing object is compatible with anything.
11279 // Use whatever requirements the new object has.
11280 out_attr[i].set_int_value(in_attr[i].int_value());
11281 }
11282 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
11283 && out_attr[i].int_value() != in_attr[i].int_value()
11284 && parameters->options().warn_mismatch()
11285 && parameters->options().enum_size_warning())
11286 {
11287 unsigned int in_value = in_attr[i].int_value();
11288 unsigned int out_value = out_attr[i].int_value();
11289 gold_warning(_("%s uses %s enums yet the output is to use "
11290 "%s enums; use of enum values across objects "
11291 "may fail"),
11292 name,
11293 this->aeabi_enum_name(in_value).c_str(),
11294 this->aeabi_enum_name(out_value).c_str());
11295 }
11296 }
11297 break;
11298 case elfcpp::Tag_ABI_VFP_args:
11299 // Already done.
11300 break;
11301 case elfcpp::Tag_ABI_WMMX_args:
11302 if (in_attr[i].int_value() != out_attr[i].int_value()
11303 && parameters->options().warn_mismatch())
11304 {
11305 gold_error(_("%s uses iWMMXt register arguments, output does "
11306 "not"),
11307 name);
11308 }
11309 break;
11310 case Object_attribute::Tag_compatibility:
11311 // Merged in target-independent code.
11312 break;
11313 case elfcpp::Tag_ABI_HardFP_use:
11314 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
11315 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
11316 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
11317 out_attr[i].set_int_value(3);
11318 else if (in_attr[i].int_value() > out_attr[i].int_value())
11319 out_attr[i].set_int_value(in_attr[i].int_value());
11320 break;
11321 case elfcpp::Tag_ABI_FP_16bit_format:
11322 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
11323 {
11324 if (in_attr[i].int_value() != out_attr[i].int_value()
11325 && parameters->options().warn_mismatch())
11326 gold_error(_("fp16 format mismatch between %s and output"),
11327 name);
11328 }
11329 if (in_attr[i].int_value() != 0)
11330 out_attr[i].set_int_value(in_attr[i].int_value());
11331 break;
11332
11333 case elfcpp::Tag_DIV_use:
11334 {
11335 // A value of zero on input means that the divide
11336 // instruction may be used if available in the base
11337 // architecture as specified via Tag_CPU_arch and
11338 // Tag_CPU_arch_profile. A value of 1 means that the user
11339 // did not want divide instructions. A value of 2
11340 // explicitly means that divide instructions were allowed
11341 // in ARM and Thumb state.
11342 int arch = this->
11343 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
11344 int_value();
11345 int profile = this->
11346 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
11347 int_value();
11348 if (in_attr[i].int_value() == out_attr[i].int_value())
11349 {
11350 // Do nothing.
11351 }
11352 else if (attributes_forbid_div(&in_attr[i])
11353 && !attributes_accept_div(arch, profile, &out_attr[i]))
11354 out_attr[i].set_int_value(1);
11355 else if (attributes_forbid_div(&out_attr[i])
11356 && attributes_accept_div(arch, profile, &in_attr[i]))
11357 out_attr[i].set_int_value(in_attr[i].int_value());
11358 else if (in_attr[i].int_value() == 2)
11359 out_attr[i].set_int_value(in_attr[i].int_value());
11360 }
11361 break;
11362
11363 case elfcpp::Tag_MPextension_use_legacy:
11364 // We don't output objects with Tag_MPextension_use_legacy - we
11365 // move the value to Tag_MPextension_use.
11366 if (in_attr[i].int_value() != 0
11367 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
11368 {
11369 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
11370 != in_attr[i].int_value())
11371 {
11372 gold_error(_("%s has has both the current and legacy "
11373 "Tag_MPextension_use attributes"),
11374 name);
11375 }
11376 }
11377
11378 if (in_attr[i].int_value()
11379 > out_attr[elfcpp::Tag_MPextension_use].int_value())
11380 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
11381
11382 break;
11383
11384 case elfcpp::Tag_nodefaults:
11385 // This tag is set if it exists, but the value is unused (and is
11386 // typically zero). We don't actually need to do anything here -
11387 // the merge happens automatically when the type flags are merged
11388 // below.
11389 break;
11390 case elfcpp::Tag_also_compatible_with:
11391 // Already done in Tag_CPU_arch.
11392 break;
11393 case elfcpp::Tag_conformance:
11394 // Keep the attribute if it matches. Throw it away otherwise.
11395 // No attribute means no claim to conform.
11396 if (in_attr[i].string_value() != out_attr[i].string_value())
11397 out_attr[i].set_string_value("");
11398 break;
11399
11400 default:
11401 {
11402 const char* err_object = NULL;
11403
11404 // The "known_obj_attributes" table does contain some undefined
11405 // attributes. Ensure that there are unused.
11406 if (out_attr[i].int_value() != 0
11407 || out_attr[i].string_value() != "")
11408 err_object = "output";
11409 else if (in_attr[i].int_value() != 0
11410 || in_attr[i].string_value() != "")
11411 err_object = name;
11412
11413 if (err_object != NULL
11414 && parameters->options().warn_mismatch())
11415 {
11416 // Attribute numbers >=64 (mod 128) can be safely ignored.
11417 if ((i & 127) < 64)
11418 gold_error(_("%s: unknown mandatory EABI object attribute "
11419 "%d"),
11420 err_object, i);
11421 else
11422 gold_warning(_("%s: unknown EABI object attribute %d"),
11423 err_object, i);
11424 }
11425
11426 // Only pass on attributes that match in both inputs.
11427 if (!in_attr[i].matches(out_attr[i]))
11428 {
11429 out_attr[i].set_int_value(0);
11430 out_attr[i].set_string_value("");
11431 }
11432 }
11433 }
11434
11435 // If out_attr was copied from in_attr then it won't have a type yet.
11436 if (in_attr[i].type() && !out_attr[i].type())
11437 out_attr[i].set_type(in_attr[i].type());
11438 }
11439
11440 // Merge Tag_compatibility attributes and any common GNU ones.
11441 this->attributes_section_data_->merge(name, pasd);
11442
11443 // Check for any attributes not known on ARM.
11444 typedef Vendor_object_attributes::Other_attributes Other_attributes;
11445 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
11446 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
11447 Other_attributes* out_other_attributes =
11448 this->attributes_section_data_->other_attributes(vendor);
11449 Other_attributes::iterator out_iter = out_other_attributes->begin();
11450
11451 while (in_iter != in_other_attributes->end()
11452 || out_iter != out_other_attributes->end())
11453 {
11454 const char* err_object = NULL;
11455 int err_tag = 0;
11456
11457 // The tags for each list are in numerical order.
11458 // If the tags are equal, then merge.
11459 if (out_iter != out_other_attributes->end()
11460 && (in_iter == in_other_attributes->end()
11461 || in_iter->first > out_iter->first))
11462 {
11463 // This attribute only exists in output. We can't merge, and we
11464 // don't know what the tag means, so delete it.
11465 err_object = "output";
11466 err_tag = out_iter->first;
11467 int saved_tag = out_iter->first;
11468 delete out_iter->second;
11469 out_other_attributes->erase(out_iter);
11470 out_iter = out_other_attributes->upper_bound(saved_tag);
11471 }
11472 else if (in_iter != in_other_attributes->end()
11473 && (out_iter != out_other_attributes->end()
11474 || in_iter->first < out_iter->first))
11475 {
11476 // This attribute only exists in input. We can't merge, and we
11477 // don't know what the tag means, so ignore it.
11478 err_object = name;
11479 err_tag = in_iter->first;
11480 ++in_iter;
11481 }
11482 else // The tags are equal.
11483 {
11484 // As present, all attributes in the list are unknown, and
11485 // therefore can't be merged meaningfully.
11486 err_object = "output";
11487 err_tag = out_iter->first;
11488
11489 // Only pass on attributes that match in both inputs.
11490 if (!in_iter->second->matches(*(out_iter->second)))
11491 {
11492 // No match. Delete the attribute.
11493 int saved_tag = out_iter->first;
11494 delete out_iter->second;
11495 out_other_attributes->erase(out_iter);
11496 out_iter = out_other_attributes->upper_bound(saved_tag);
11497 }
11498 else
11499 {
11500 // Matched. Keep the attribute and move to the next.
11501 ++out_iter;
11502 ++in_iter;
11503 }
11504 }
11505
11506 if (err_object && parameters->options().warn_mismatch())
11507 {
11508 // Attribute numbers >=64 (mod 128) can be safely ignored. */
11509 if ((err_tag & 127) < 64)
11510 {
11511 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
11512 err_object, err_tag);
11513 }
11514 else
11515 {
11516 gold_warning(_("%s: unknown EABI object attribute %d"),
11517 err_object, err_tag);
11518 }
11519 }
11520 }
11521 }
11522
11523 // Stub-generation methods for Target_arm.
11524
11525 // Make a new Arm_input_section object.
11526
11527 template<bool big_endian>
11528 Arm_input_section<big_endian>*
11529 Target_arm<big_endian>::new_arm_input_section(
11530 Relobj* relobj,
11531 unsigned int shndx)
11532 {
11533 Section_id sid(relobj, shndx);
11534
11535 Arm_input_section<big_endian>* arm_input_section =
11536 new Arm_input_section<big_endian>(relobj, shndx);
11537 arm_input_section->init();
11538
11539 // Register new Arm_input_section in map for look-up.
11540 std::pair<typename Arm_input_section_map::iterator, bool> ins =
11541 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11542
11543 // Make sure that it we have not created another Arm_input_section
11544 // for this input section already.
11545 gold_assert(ins.second);
11546
11547 return arm_input_section;
11548 }
11549
11550 // Find the Arm_input_section object corresponding to the SHNDX-th input
11551 // section of RELOBJ.
11552
11553 template<bool big_endian>
11554 Arm_input_section<big_endian>*
11555 Target_arm<big_endian>::find_arm_input_section(
11556 Relobj* relobj,
11557 unsigned int shndx) const
11558 {
11559 Section_id sid(relobj, shndx);
11560 typename Arm_input_section_map::const_iterator p =
11561 this->arm_input_section_map_.find(sid);
11562 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11563 }
11564
11565 // Make a new stub table.
11566
11567 template<bool big_endian>
11568 Stub_table<big_endian>*
11569 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11570 {
11571 Stub_table<big_endian>* stub_table =
11572 new Stub_table<big_endian>(owner);
11573 this->stub_tables_.push_back(stub_table);
11574
11575 stub_table->set_address(owner->address() + owner->data_size());
11576 stub_table->set_file_offset(owner->offset() + owner->data_size());
11577 stub_table->finalize_data_size();
11578
11579 return stub_table;
11580 }
11581
11582 // Scan a relocation for stub generation.
11583
11584 template<bool big_endian>
11585 void
11586 Target_arm<big_endian>::scan_reloc_for_stub(
11587 const Relocate_info<32, big_endian>* relinfo,
11588 unsigned int r_type,
11589 const Sized_symbol<32>* gsym,
11590 unsigned int r_sym,
11591 const Symbol_value<32>* psymval,
11592 elfcpp::Elf_types<32>::Elf_Swxword addend,
11593 Arm_address address)
11594 {
11595 const Arm_relobj<big_endian>* arm_relobj =
11596 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11597
11598 bool target_is_thumb;
11599 Symbol_value<32> symval;
11600 if (gsym != NULL)
11601 {
11602 // This is a global symbol. Determine if we use PLT and if the
11603 // final target is THUMB.
11604 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11605 {
11606 // This uses a PLT, change the symbol value.
11607 symval.set_output_value(this->plt_address_for_global(gsym));
11608 psymval = &symval;
11609 target_is_thumb = false;
11610 }
11611 else if (gsym->is_undefined())
11612 // There is no need to generate a stub symbol is undefined.
11613 return;
11614 else
11615 {
11616 target_is_thumb =
11617 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11618 || (gsym->type() == elfcpp::STT_FUNC
11619 && !gsym->is_undefined()
11620 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11621 }
11622 }
11623 else
11624 {
11625 // This is a local symbol. Determine if the final target is THUMB.
11626 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11627 }
11628
11629 // Strip LSB if this points to a THUMB target.
11630 const Arm_reloc_property* reloc_property =
11631 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11632 gold_assert(reloc_property != NULL);
11633 if (target_is_thumb
11634 && reloc_property->uses_thumb_bit()
11635 && ((psymval->value(arm_relobj, 0) & 1) != 0))
11636 {
11637 Arm_address stripped_value =
11638 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11639 symval.set_output_value(stripped_value);
11640 psymval = &symval;
11641 }
11642
11643 // Get the symbol value.
11644 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11645
11646 // Owing to pipelining, the PC relative branches below actually skip
11647 // two instructions when the branch offset is 0.
11648 Arm_address destination;
11649 switch (r_type)
11650 {
11651 case elfcpp::R_ARM_CALL:
11652 case elfcpp::R_ARM_JUMP24:
11653 case elfcpp::R_ARM_PLT32:
11654 // ARM branches.
11655 destination = value + addend + 8;
11656 break;
11657 case elfcpp::R_ARM_THM_CALL:
11658 case elfcpp::R_ARM_THM_XPC22:
11659 case elfcpp::R_ARM_THM_JUMP24:
11660 case elfcpp::R_ARM_THM_JUMP19:
11661 // THUMB branches.
11662 destination = value + addend + 4;
11663 break;
11664 default:
11665 gold_unreachable();
11666 }
11667
11668 Reloc_stub* stub = NULL;
11669 Stub_type stub_type =
11670 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11671 target_is_thumb);
11672 if (stub_type != arm_stub_none)
11673 {
11674 // Try looking up an existing stub from a stub table.
11675 Stub_table<big_endian>* stub_table =
11676 arm_relobj->stub_table(relinfo->data_shndx);
11677 gold_assert(stub_table != NULL);
11678
11679 // Locate stub by destination.
11680 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11681
11682 // Create a stub if there is not one already
11683 stub = stub_table->find_reloc_stub(stub_key);
11684 if (stub == NULL)
11685 {
11686 // create a new stub and add it to stub table.
11687 stub = this->stub_factory().make_reloc_stub(stub_type);
11688 stub_table->add_reloc_stub(stub, stub_key);
11689 }
11690
11691 // Record the destination address.
11692 stub->set_destination_address(destination
11693 | (target_is_thumb ? 1 : 0));
11694 }
11695
11696 // For Cortex-A8, we need to record a relocation at 4K page boundary.
11697 if (this->fix_cortex_a8_
11698 && (r_type == elfcpp::R_ARM_THM_JUMP24
11699 || r_type == elfcpp::R_ARM_THM_JUMP19
11700 || r_type == elfcpp::R_ARM_THM_CALL
11701 || r_type == elfcpp::R_ARM_THM_XPC22)
11702 && (address & 0xfffU) == 0xffeU)
11703 {
11704 // Found a candidate. Note we haven't checked the destination is
11705 // within 4K here: if we do so (and don't create a record) we can't
11706 // tell that a branch should have been relocated when scanning later.
11707 this->cortex_a8_relocs_info_[address] =
11708 new Cortex_a8_reloc(stub, r_type,
11709 destination | (target_is_thumb ? 1 : 0));
11710 }
11711 }
11712
11713 // This function scans a relocation sections for stub generation.
11714 // The template parameter Relocate must be a class type which provides
11715 // a single function, relocate(), which implements the machine
11716 // specific part of a relocation.
11717
11718 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11719 // SHT_REL or SHT_RELA.
11720
11721 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11722 // of relocs. OUTPUT_SECTION is the output section.
11723 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11724 // mapped to output offsets.
11725
11726 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11727 // VIEW_SIZE is the size. These refer to the input section, unless
11728 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11729 // the output section.
11730
11731 template<bool big_endian>
11732 template<int sh_type>
11733 void inline
11734 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11735 const Relocate_info<32, big_endian>* relinfo,
11736 const unsigned char* prelocs,
11737 size_t reloc_count,
11738 Output_section* output_section,
11739 bool needs_special_offset_handling,
11740 const unsigned char* view,
11741 elfcpp::Elf_types<32>::Elf_Addr view_address,
11742 section_size_type)
11743 {
11744 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11745 const int reloc_size =
11746 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11747
11748 Arm_relobj<big_endian>* arm_object =
11749 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11750 unsigned int local_count = arm_object->local_symbol_count();
11751
11752 gold::Default_comdat_behavior default_comdat_behavior;
11753 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11754
11755 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11756 {
11757 Reltype reloc(prelocs);
11758
11759 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11760 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11761 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11762
11763 r_type = this->get_real_reloc_type(r_type);
11764
11765 // Only a few relocation types need stubs.
11766 if ((r_type != elfcpp::R_ARM_CALL)
11767 && (r_type != elfcpp::R_ARM_JUMP24)
11768 && (r_type != elfcpp::R_ARM_PLT32)
11769 && (r_type != elfcpp::R_ARM_THM_CALL)
11770 && (r_type != elfcpp::R_ARM_THM_XPC22)
11771 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11772 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11773 && (r_type != elfcpp::R_ARM_V4BX))
11774 continue;
11775
11776 section_offset_type offset =
11777 convert_to_section_size_type(reloc.get_r_offset());
11778
11779 if (needs_special_offset_handling)
11780 {
11781 offset = output_section->output_offset(relinfo->object,
11782 relinfo->data_shndx,
11783 offset);
11784 if (offset == -1)
11785 continue;
11786 }
11787
11788 // Create a v4bx stub if --fix-v4bx-interworking is used.
11789 if (r_type == elfcpp::R_ARM_V4BX)
11790 {
11791 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11792 {
11793 // Get the BX instruction.
11794 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11795 const Valtype* wv =
11796 reinterpret_cast<const Valtype*>(view + offset);
11797 elfcpp::Elf_types<32>::Elf_Swxword insn =
11798 elfcpp::Swap<32, big_endian>::readval(wv);
11799 const uint32_t reg = (insn & 0xf);
11800
11801 if (reg < 0xf)
11802 {
11803 // Try looking up an existing stub from a stub table.
11804 Stub_table<big_endian>* stub_table =
11805 arm_object->stub_table(relinfo->data_shndx);
11806 gold_assert(stub_table != NULL);
11807
11808 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11809 {
11810 // create a new stub and add it to stub table.
11811 Arm_v4bx_stub* stub =
11812 this->stub_factory().make_arm_v4bx_stub(reg);
11813 gold_assert(stub != NULL);
11814 stub_table->add_arm_v4bx_stub(stub);
11815 }
11816 }
11817 }
11818 continue;
11819 }
11820
11821 // Get the addend.
11822 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11823 elfcpp::Elf_types<32>::Elf_Swxword addend =
11824 stub_addend_reader(r_type, view + offset, reloc);
11825
11826 const Sized_symbol<32>* sym;
11827
11828 Symbol_value<32> symval;
11829 const Symbol_value<32> *psymval;
11830 bool is_defined_in_discarded_section;
11831 unsigned int shndx;
11832 if (r_sym < local_count)
11833 {
11834 sym = NULL;
11835 psymval = arm_object->local_symbol(r_sym);
11836
11837 // If the local symbol belongs to a section we are discarding,
11838 // and that section is a debug section, try to find the
11839 // corresponding kept section and map this symbol to its
11840 // counterpart in the kept section. The symbol must not
11841 // correspond to a section we are folding.
11842 bool is_ordinary;
11843 shndx = psymval->input_shndx(&is_ordinary);
11844 is_defined_in_discarded_section =
11845 (is_ordinary
11846 && shndx != elfcpp::SHN_UNDEF
11847 && !arm_object->is_section_included(shndx)
11848 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11849
11850 // We need to compute the would-be final value of this local
11851 // symbol.
11852 if (!is_defined_in_discarded_section)
11853 {
11854 typedef Sized_relobj_file<32, big_endian> ObjType;
11855 typename ObjType::Compute_final_local_value_status status =
11856 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11857 relinfo->symtab);
11858 if (status == ObjType::CFLV_OK)
11859 {
11860 // Currently we cannot handle a branch to a target in
11861 // a merged section. If this is the case, issue an error
11862 // and also free the merge symbol value.
11863 if (!symval.has_output_value())
11864 {
11865 const std::string& section_name =
11866 arm_object->section_name(shndx);
11867 arm_object->error(_("cannot handle branch to local %u "
11868 "in a merged section %s"),
11869 r_sym, section_name.c_str());
11870 }
11871 psymval = &symval;
11872 }
11873 else
11874 {
11875 // We cannot determine the final value.
11876 continue;
11877 }
11878 }
11879 }
11880 else
11881 {
11882 const Symbol* gsym;
11883 gsym = arm_object->global_symbol(r_sym);
11884 gold_assert(gsym != NULL);
11885 if (gsym->is_forwarder())
11886 gsym = relinfo->symtab->resolve_forwards(gsym);
11887
11888 sym = static_cast<const Sized_symbol<32>*>(gsym);
11889 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11890 symval.set_output_symtab_index(sym->symtab_index());
11891 else
11892 symval.set_no_output_symtab_entry();
11893
11894 // We need to compute the would-be final value of this global
11895 // symbol.
11896 const Symbol_table* symtab = relinfo->symtab;
11897 const Sized_symbol<32>* sized_symbol =
11898 symtab->get_sized_symbol<32>(gsym);
11899 Symbol_table::Compute_final_value_status status;
11900 Arm_address value =
11901 symtab->compute_final_value<32>(sized_symbol, &status);
11902
11903 // Skip this if the symbol has not output section.
11904 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11905 continue;
11906 symval.set_output_value(value);
11907
11908 if (gsym->type() == elfcpp::STT_TLS)
11909 symval.set_is_tls_symbol();
11910 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11911 symval.set_is_ifunc_symbol();
11912 psymval = &symval;
11913
11914 is_defined_in_discarded_section =
11915 (gsym->is_defined_in_discarded_section()
11916 && gsym->is_undefined());
11917 shndx = 0;
11918 }
11919
11920 Symbol_value<32> symval2;
11921 if (is_defined_in_discarded_section)
11922 {
11923 if (comdat_behavior == CB_UNDETERMINED)
11924 {
11925 std::string name = arm_object->section_name(relinfo->data_shndx);
11926 comdat_behavior = default_comdat_behavior.get(name.c_str());
11927 }
11928 if (comdat_behavior == CB_PRETEND)
11929 {
11930 // FIXME: This case does not work for global symbols.
11931 // We have no place to store the original section index.
11932 // Fortunately this does not matter for comdat sections,
11933 // only for sections explicitly discarded by a linker
11934 // script.
11935 bool found;
11936 typename elfcpp::Elf_types<32>::Elf_Addr value =
11937 arm_object->map_to_kept_section(shndx, &found);
11938 if (found)
11939 symval2.set_output_value(value + psymval->input_value());
11940 else
11941 symval2.set_output_value(0);
11942 }
11943 else
11944 {
11945 if (comdat_behavior == CB_WARNING)
11946 gold_warning_at_location(relinfo, i, offset,
11947 _("relocation refers to discarded "
11948 "section"));
11949 symval2.set_output_value(0);
11950 }
11951 symval2.set_no_output_symtab_entry();
11952 psymval = &symval2;
11953 }
11954
11955 // If symbol is a section symbol, we don't know the actual type of
11956 // destination. Give up.
11957 if (psymval->is_section_symbol())
11958 continue;
11959
11960 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11961 addend, view_address + offset);
11962 }
11963 }
11964
11965 // Scan an input section for stub generation.
11966
11967 template<bool big_endian>
11968 void
11969 Target_arm<big_endian>::scan_section_for_stubs(
11970 const Relocate_info<32, big_endian>* relinfo,
11971 unsigned int sh_type,
11972 const unsigned char* prelocs,
11973 size_t reloc_count,
11974 Output_section* output_section,
11975 bool needs_special_offset_handling,
11976 const unsigned char* view,
11977 Arm_address view_address,
11978 section_size_type view_size)
11979 {
11980 if (sh_type == elfcpp::SHT_REL)
11981 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11982 relinfo,
11983 prelocs,
11984 reloc_count,
11985 output_section,
11986 needs_special_offset_handling,
11987 view,
11988 view_address,
11989 view_size);
11990 else if (sh_type == elfcpp::SHT_RELA)
11991 // We do not support RELA type relocations yet. This is provided for
11992 // completeness.
11993 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11994 relinfo,
11995 prelocs,
11996 reloc_count,
11997 output_section,
11998 needs_special_offset_handling,
11999 view,
12000 view_address,
12001 view_size);
12002 else
12003 gold_unreachable();
12004 }
12005
12006 // Group input sections for stub generation.
12007 //
12008 // We group input sections in an output section so that the total size,
12009 // including any padding space due to alignment is smaller than GROUP_SIZE
12010 // unless the only input section in group is bigger than GROUP_SIZE already.
12011 // Then an ARM stub table is created to follow the last input section
12012 // in group. For each group an ARM stub table is created an is placed
12013 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
12014 // extend the group after the stub table.
12015
12016 template<bool big_endian>
12017 void
12018 Target_arm<big_endian>::group_sections(
12019 Layout* layout,
12020 section_size_type group_size,
12021 bool stubs_always_after_branch,
12022 const Task* task)
12023 {
12024 // Group input sections and insert stub table
12025 Layout::Section_list section_list;
12026 layout->get_executable_sections(&section_list);
12027 for (Layout::Section_list::const_iterator p = section_list.begin();
12028 p != section_list.end();
12029 ++p)
12030 {
12031 Arm_output_section<big_endian>* output_section =
12032 Arm_output_section<big_endian>::as_arm_output_section(*p);
12033 output_section->group_sections(group_size, stubs_always_after_branch,
12034 this, task);
12035 }
12036 }
12037
12038 // Relaxation hook. This is where we do stub generation.
12039
12040 template<bool big_endian>
12041 bool
12042 Target_arm<big_endian>::do_relax(
12043 int pass,
12044 const Input_objects* input_objects,
12045 Symbol_table* symtab,
12046 Layout* layout,
12047 const Task* task)
12048 {
12049 // No need to generate stubs if this is a relocatable link.
12050 gold_assert(!parameters->options().relocatable());
12051
12052 // If this is the first pass, we need to group input sections into
12053 // stub groups.
12054 bool done_exidx_fixup = false;
12055 typedef typename Stub_table_list::iterator Stub_table_iterator;
12056 if (pass == 1)
12057 {
12058 // Determine the stub group size. The group size is the absolute
12059 // value of the parameter --stub-group-size. If --stub-group-size
12060 // is passed a negative value, we restrict stubs to be always after
12061 // the stubbed branches.
12062 int32_t stub_group_size_param =
12063 parameters->options().stub_group_size();
12064 bool stubs_always_after_branch = stub_group_size_param < 0;
12065 section_size_type stub_group_size = abs(stub_group_size_param);
12066
12067 if (stub_group_size == 1)
12068 {
12069 // Default value.
12070 // Thumb branch range is +-4MB has to be used as the default
12071 // maximum size (a given section can contain both ARM and Thumb
12072 // code, so the worst case has to be taken into account). If we are
12073 // fixing cortex-a8 errata, the branch range has to be even smaller,
12074 // since wide conditional branch has a range of +-1MB only.
12075 //
12076 // This value is 48K less than that, which allows for 4096
12077 // 12-byte stubs. If we exceed that, then we will fail to link.
12078 // The user will have to relink with an explicit group size
12079 // option.
12080 stub_group_size = 4145152;
12081 }
12082
12083 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
12084 // page as the first half of a 32-bit branch straddling two 4K pages.
12085 // This is a crude way of enforcing that. In addition, long conditional
12086 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
12087 // erratum, limit the group size to (1M - 12k) to avoid unreachable
12088 // cortex-A8 stubs from long conditional branches.
12089 if (this->fix_cortex_a8_)
12090 {
12091 stubs_always_after_branch = true;
12092 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
12093 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
12094 }
12095
12096 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
12097
12098 // Also fix .ARM.exidx section coverage.
12099 Arm_output_section<big_endian>* exidx_output_section = NULL;
12100 for (Layout::Section_list::const_iterator p =
12101 layout->section_list().begin();
12102 p != layout->section_list().end();
12103 ++p)
12104 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
12105 {
12106 if (exidx_output_section == NULL)
12107 exidx_output_section =
12108 Arm_output_section<big_endian>::as_arm_output_section(*p);
12109 else
12110 // We cannot handle this now.
12111 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
12112 "non-relocatable link"),
12113 exidx_output_section->name(),
12114 (*p)->name());
12115 }
12116
12117 if (exidx_output_section != NULL)
12118 {
12119 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
12120 symtab, task);
12121 done_exidx_fixup = true;
12122 }
12123 }
12124 else
12125 {
12126 // If this is not the first pass, addresses and file offsets have
12127 // been reset at this point, set them here.
12128 for (Stub_table_iterator sp = this->stub_tables_.begin();
12129 sp != this->stub_tables_.end();
12130 ++sp)
12131 {
12132 Arm_input_section<big_endian>* owner = (*sp)->owner();
12133 off_t off = align_address(owner->original_size(),
12134 (*sp)->addralign());
12135 (*sp)->set_address_and_file_offset(owner->address() + off,
12136 owner->offset() + off);
12137 }
12138 }
12139
12140 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
12141 // beginning of each relaxation pass, just blow away all the stubs.
12142 // Alternatively, we could selectively remove only the stubs and reloc
12143 // information for code sections that have moved since the last pass.
12144 // That would require more book-keeping.
12145 if (this->fix_cortex_a8_)
12146 {
12147 // Clear all Cortex-A8 reloc information.
12148 for (typename Cortex_a8_relocs_info::const_iterator p =
12149 this->cortex_a8_relocs_info_.begin();
12150 p != this->cortex_a8_relocs_info_.end();
12151 ++p)
12152 delete p->second;
12153 this->cortex_a8_relocs_info_.clear();
12154
12155 // Remove all Cortex-A8 stubs.
12156 for (Stub_table_iterator sp = this->stub_tables_.begin();
12157 sp != this->stub_tables_.end();
12158 ++sp)
12159 (*sp)->remove_all_cortex_a8_stubs();
12160 }
12161
12162 // Scan relocs for relocation stubs
12163 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12164 op != input_objects->relobj_end();
12165 ++op)
12166 {
12167 Arm_relobj<big_endian>* arm_relobj =
12168 Arm_relobj<big_endian>::as_arm_relobj(*op);
12169 // Lock the object so we can read from it. This is only called
12170 // single-threaded from Layout::finalize, so it is OK to lock.
12171 Task_lock_obj<Object> tl(task, arm_relobj);
12172 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
12173 }
12174
12175 // Check all stub tables to see if any of them have their data sizes
12176 // or addresses alignments changed. These are the only things that
12177 // matter.
12178 bool any_stub_table_changed = false;
12179 Unordered_set<const Output_section*> sections_needing_adjustment;
12180 for (Stub_table_iterator sp = this->stub_tables_.begin();
12181 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12182 ++sp)
12183 {
12184 if ((*sp)->update_data_size_and_addralign())
12185 {
12186 // Update data size of stub table owner.
12187 Arm_input_section<big_endian>* owner = (*sp)->owner();
12188 uint64_t address = owner->address();
12189 off_t offset = owner->offset();
12190 owner->reset_address_and_file_offset();
12191 owner->set_address_and_file_offset(address, offset);
12192
12193 sections_needing_adjustment.insert(owner->output_section());
12194 any_stub_table_changed = true;
12195 }
12196 }
12197
12198 // Output_section_data::output_section() returns a const pointer but we
12199 // need to update output sections, so we record all output sections needing
12200 // update above and scan the sections here to find out what sections need
12201 // to be updated.
12202 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
12203 p != layout->section_list().end();
12204 ++p)
12205 {
12206 if (sections_needing_adjustment.find(*p)
12207 != sections_needing_adjustment.end())
12208 (*p)->set_section_offsets_need_adjustment();
12209 }
12210
12211 // Stop relaxation if no EXIDX fix-up and no stub table change.
12212 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
12213
12214 // Finalize the stubs in the last relaxation pass.
12215 if (!continue_relaxation)
12216 {
12217 for (Stub_table_iterator sp = this->stub_tables_.begin();
12218 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
12219 ++sp)
12220 (*sp)->finalize_stubs();
12221
12222 // Update output local symbol counts of objects if necessary.
12223 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
12224 op != input_objects->relobj_end();
12225 ++op)
12226 {
12227 Arm_relobj<big_endian>* arm_relobj =
12228 Arm_relobj<big_endian>::as_arm_relobj(*op);
12229
12230 // Update output local symbol counts. We need to discard local
12231 // symbols defined in parts of input sections that are discarded by
12232 // relaxation.
12233 if (arm_relobj->output_local_symbol_count_needs_update())
12234 {
12235 // We need to lock the object's file to update it.
12236 Task_lock_obj<Object> tl(task, arm_relobj);
12237 arm_relobj->update_output_local_symbol_count();
12238 }
12239 }
12240 }
12241
12242 return continue_relaxation;
12243 }
12244
12245 // Relocate a stub.
12246
12247 template<bool big_endian>
12248 void
12249 Target_arm<big_endian>::relocate_stub(
12250 Stub* stub,
12251 const Relocate_info<32, big_endian>* relinfo,
12252 Output_section* output_section,
12253 unsigned char* view,
12254 Arm_address address,
12255 section_size_type view_size)
12256 {
12257 Relocate relocate;
12258 const Stub_template* stub_template = stub->stub_template();
12259 for (size_t i = 0; i < stub_template->reloc_count(); i++)
12260 {
12261 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
12262 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
12263
12264 unsigned int r_type = insn->r_type();
12265 section_size_type reloc_offset = stub_template->reloc_offset(i);
12266 section_size_type reloc_size = insn->size();
12267 gold_assert(reloc_offset + reloc_size <= view_size);
12268
12269 // This is the address of the stub destination.
12270 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
12271 Symbol_value<32> symval;
12272 symval.set_output_value(target);
12273
12274 // Synthesize a fake reloc just in case. We don't have a symbol so
12275 // we use 0.
12276 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
12277 memset(reloc_buffer, 0, sizeof(reloc_buffer));
12278 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
12279 reloc_write.put_r_offset(reloc_offset);
12280 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
12281 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
12282
12283 relocate.relocate(relinfo, this, output_section,
12284 this->fake_relnum_for_stubs, rel, r_type,
12285 NULL, &symval, view + reloc_offset,
12286 address + reloc_offset, reloc_size);
12287 }
12288 }
12289
12290 // Determine whether an object attribute tag takes an integer, a
12291 // string or both.
12292
12293 template<bool big_endian>
12294 int
12295 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
12296 {
12297 if (tag == Object_attribute::Tag_compatibility)
12298 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12299 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
12300 else if (tag == elfcpp::Tag_nodefaults)
12301 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
12302 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
12303 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
12304 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
12305 else if (tag < 32)
12306 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
12307 else
12308 return ((tag & 1) != 0
12309 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
12310 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
12311 }
12312
12313 // Reorder attributes.
12314 //
12315 // The ABI defines that Tag_conformance should be emitted first, and that
12316 // Tag_nodefaults should be second (if either is defined). This sets those
12317 // two positions, and bumps up the position of all the remaining tags to
12318 // compensate.
12319
12320 template<bool big_endian>
12321 int
12322 Target_arm<big_endian>::do_attributes_order(int num) const
12323 {
12324 // Reorder the known object attributes in output. We want to move
12325 // Tag_conformance to position 4 and Tag_conformance to position 5
12326 // and shift everything between 4 .. Tag_conformance - 1 to make room.
12327 if (num == 4)
12328 return elfcpp::Tag_conformance;
12329 if (num == 5)
12330 return elfcpp::Tag_nodefaults;
12331 if ((num - 2) < elfcpp::Tag_nodefaults)
12332 return num - 2;
12333 if ((num - 1) < elfcpp::Tag_conformance)
12334 return num - 1;
12335 return num;
12336 }
12337
12338 // Scan a span of THUMB code for Cortex-A8 erratum.
12339
12340 template<bool big_endian>
12341 void
12342 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
12343 Arm_relobj<big_endian>* arm_relobj,
12344 unsigned int shndx,
12345 section_size_type span_start,
12346 section_size_type span_end,
12347 const unsigned char* view,
12348 Arm_address address)
12349 {
12350 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
12351 //
12352 // The opcode is BLX.W, BL.W, B.W, Bcc.W
12353 // The branch target is in the same 4KB region as the
12354 // first half of the branch.
12355 // The instruction before the branch is a 32-bit
12356 // length non-branch instruction.
12357 section_size_type i = span_start;
12358 bool last_was_32bit = false;
12359 bool last_was_branch = false;
12360 while (i < span_end)
12361 {
12362 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12363 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
12364 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
12365 bool is_blx = false, is_b = false;
12366 bool is_bl = false, is_bcc = false;
12367
12368 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
12369 if (insn_32bit)
12370 {
12371 // Load the rest of the insn (in manual-friendly order).
12372 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
12373
12374 // Encoding T4: B<c>.W.
12375 is_b = (insn & 0xf800d000U) == 0xf0009000U;
12376 // Encoding T1: BL<c>.W.
12377 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
12378 // Encoding T2: BLX<c>.W.
12379 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
12380 // Encoding T3: B<c>.W (not permitted in IT block).
12381 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
12382 && (insn & 0x07f00000U) != 0x03800000U);
12383 }
12384
12385 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
12386
12387 // If this instruction is a 32-bit THUMB branch that crosses a 4K
12388 // page boundary and it follows 32-bit non-branch instruction,
12389 // we need to work around.
12390 if (is_32bit_branch
12391 && ((address + i) & 0xfffU) == 0xffeU
12392 && last_was_32bit
12393 && !last_was_branch)
12394 {
12395 // Check to see if there is a relocation stub for this branch.
12396 bool force_target_arm = false;
12397 bool force_target_thumb = false;
12398 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
12399 Cortex_a8_relocs_info::const_iterator p =
12400 this->cortex_a8_relocs_info_.find(address + i);
12401
12402 if (p != this->cortex_a8_relocs_info_.end())
12403 {
12404 cortex_a8_reloc = p->second;
12405 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
12406
12407 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12408 && !target_is_thumb)
12409 force_target_arm = true;
12410 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
12411 && target_is_thumb)
12412 force_target_thumb = true;
12413 }
12414
12415 off_t offset;
12416 Stub_type stub_type = arm_stub_none;
12417
12418 // Check if we have an offending branch instruction.
12419 uint16_t upper_insn = (insn >> 16) & 0xffffU;
12420 uint16_t lower_insn = insn & 0xffffU;
12421 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12422
12423 if (cortex_a8_reloc != NULL
12424 && cortex_a8_reloc->reloc_stub() != NULL)
12425 // We've already made a stub for this instruction, e.g.
12426 // it's a long branch or a Thumb->ARM stub. Assume that
12427 // stub will suffice to work around the A8 erratum (see
12428 // setting of always_after_branch above).
12429 ;
12430 else if (is_bcc)
12431 {
12432 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
12433 lower_insn);
12434 stub_type = arm_stub_a8_veneer_b_cond;
12435 }
12436 else if (is_b || is_bl || is_blx)
12437 {
12438 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
12439 lower_insn);
12440 if (is_blx)
12441 offset &= ~3;
12442
12443 stub_type = (is_blx
12444 ? arm_stub_a8_veneer_blx
12445 : (is_bl
12446 ? arm_stub_a8_veneer_bl
12447 : arm_stub_a8_veneer_b));
12448 }
12449
12450 if (stub_type != arm_stub_none)
12451 {
12452 Arm_address pc_for_insn = address + i + 4;
12453
12454 // The original instruction is a BL, but the target is
12455 // an ARM instruction. If we were not making a stub,
12456 // the BL would have been converted to a BLX. Use the
12457 // BLX stub instead in that case.
12458 if (this->may_use_v5t_interworking() && force_target_arm
12459 && stub_type == arm_stub_a8_veneer_bl)
12460 {
12461 stub_type = arm_stub_a8_veneer_blx;
12462 is_blx = true;
12463 is_bl = false;
12464 }
12465 // Conversely, if the original instruction was
12466 // BLX but the target is Thumb mode, use the BL stub.
12467 else if (force_target_thumb
12468 && stub_type == arm_stub_a8_veneer_blx)
12469 {
12470 stub_type = arm_stub_a8_veneer_bl;
12471 is_blx = false;
12472 is_bl = true;
12473 }
12474
12475 if (is_blx)
12476 pc_for_insn &= ~3;
12477
12478 // If we found a relocation, use the proper destination,
12479 // not the offset in the (unrelocated) instruction.
12480 // Note this is always done if we switched the stub type above.
12481 if (cortex_a8_reloc != NULL)
12482 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
12483
12484 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
12485
12486 // Add a new stub if destination address in in the same page.
12487 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
12488 {
12489 Cortex_a8_stub* stub =
12490 this->stub_factory_.make_cortex_a8_stub(stub_type,
12491 arm_relobj, shndx,
12492 address + i,
12493 target, insn);
12494 Stub_table<big_endian>* stub_table =
12495 arm_relobj->stub_table(shndx);
12496 gold_assert(stub_table != NULL);
12497 stub_table->add_cortex_a8_stub(address + i, stub);
12498 }
12499 }
12500 }
12501
12502 i += insn_32bit ? 4 : 2;
12503 last_was_32bit = insn_32bit;
12504 last_was_branch = is_32bit_branch;
12505 }
12506 }
12507
12508 // Apply the Cortex-A8 workaround.
12509
12510 template<bool big_endian>
12511 void
12512 Target_arm<big_endian>::apply_cortex_a8_workaround(
12513 const Cortex_a8_stub* stub,
12514 Arm_address stub_address,
12515 unsigned char* insn_view,
12516 Arm_address insn_address)
12517 {
12518 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12519 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12520 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12521 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12522 off_t branch_offset = stub_address - (insn_address + 4);
12523
12524 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12525 switch (stub->stub_template()->type())
12526 {
12527 case arm_stub_a8_veneer_b_cond:
12528 // For a conditional branch, we re-write it to be an unconditional
12529 // branch to the stub. We use the THUMB-2 encoding here.
12530 upper_insn = 0xf000U;
12531 lower_insn = 0xb800U;
12532 // Fall through
12533 case arm_stub_a8_veneer_b:
12534 case arm_stub_a8_veneer_bl:
12535 case arm_stub_a8_veneer_blx:
12536 if ((lower_insn & 0x5000U) == 0x4000U)
12537 // For a BLX instruction, make sure that the relocation is
12538 // rounded up to a word boundary. This follows the semantics of
12539 // the instruction which specifies that bit 1 of the target
12540 // address will come from bit 1 of the base address.
12541 branch_offset = (branch_offset + 2) & ~3;
12542
12543 // Put BRANCH_OFFSET back into the insn.
12544 gold_assert(!Bits<25>::has_overflow32(branch_offset));
12545 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12546 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12547 break;
12548
12549 default:
12550 gold_unreachable();
12551 }
12552
12553 // Put the relocated value back in the object file:
12554 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12555 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12556 }
12557
12558 // Target selector for ARM. Note this is never instantiated directly.
12559 // It's only used in Target_selector_arm_nacl, below.
12560
12561 template<bool big_endian>
12562 class Target_selector_arm : public Target_selector
12563 {
12564 public:
12565 Target_selector_arm()
12566 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12567 (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12568 (big_endian ? "armelfb" : "armelf"))
12569 { }
12570
12571 Target*
12572 do_instantiate_target()
12573 { return new Target_arm<big_endian>(); }
12574 };
12575
12576 // Fix .ARM.exidx section coverage.
12577
12578 template<bool big_endian>
12579 void
12580 Target_arm<big_endian>::fix_exidx_coverage(
12581 Layout* layout,
12582 const Input_objects* input_objects,
12583 Arm_output_section<big_endian>* exidx_section,
12584 Symbol_table* symtab,
12585 const Task* task)
12586 {
12587 // We need to look at all the input sections in output in ascending
12588 // order of of output address. We do that by building a sorted list
12589 // of output sections by addresses. Then we looks at the output sections
12590 // in order. The input sections in an output section are already sorted
12591 // by addresses within the output section.
12592
12593 typedef std::set<Output_section*, output_section_address_less_than>
12594 Sorted_output_section_list;
12595 Sorted_output_section_list sorted_output_sections;
12596
12597 // Find out all the output sections of input sections pointed by
12598 // EXIDX input sections.
12599 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12600 p != input_objects->relobj_end();
12601 ++p)
12602 {
12603 Arm_relobj<big_endian>* arm_relobj =
12604 Arm_relobj<big_endian>::as_arm_relobj(*p);
12605 std::vector<unsigned int> shndx_list;
12606 arm_relobj->get_exidx_shndx_list(&shndx_list);
12607 for (size_t i = 0; i < shndx_list.size(); ++i)
12608 {
12609 const Arm_exidx_input_section* exidx_input_section =
12610 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12611 gold_assert(exidx_input_section != NULL);
12612 if (!exidx_input_section->has_errors())
12613 {
12614 unsigned int text_shndx = exidx_input_section->link();
12615 Output_section* os = arm_relobj->output_section(text_shndx);
12616 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12617 sorted_output_sections.insert(os);
12618 }
12619 }
12620 }
12621
12622 // Go over the output sections in ascending order of output addresses.
12623 typedef typename Arm_output_section<big_endian>::Text_section_list
12624 Text_section_list;
12625 Text_section_list sorted_text_sections;
12626 for (typename Sorted_output_section_list::iterator p =
12627 sorted_output_sections.begin();
12628 p != sorted_output_sections.end();
12629 ++p)
12630 {
12631 Arm_output_section<big_endian>* arm_output_section =
12632 Arm_output_section<big_endian>::as_arm_output_section(*p);
12633 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12634 }
12635
12636 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12637 merge_exidx_entries(), task);
12638 }
12639
12640 template<bool big_endian>
12641 void
12642 Target_arm<big_endian>::do_define_standard_symbols(
12643 Symbol_table* symtab,
12644 Layout* layout)
12645 {
12646 // Handle the .ARM.exidx section.
12647 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12648
12649 if (exidx_section != NULL)
12650 {
12651 // Create __exidx_start and __exidx_end symbols.
12652 symtab->define_in_output_data("__exidx_start",
12653 NULL, // version
12654 Symbol_table::PREDEFINED,
12655 exidx_section,
12656 0, // value
12657 0, // symsize
12658 elfcpp::STT_NOTYPE,
12659 elfcpp::STB_GLOBAL,
12660 elfcpp::STV_HIDDEN,
12661 0, // nonvis
12662 false, // offset_is_from_end
12663 true); // only_if_ref
12664
12665 symtab->define_in_output_data("__exidx_end",
12666 NULL, // version
12667 Symbol_table::PREDEFINED,
12668 exidx_section,
12669 0, // value
12670 0, // symsize
12671 elfcpp::STT_NOTYPE,
12672 elfcpp::STB_GLOBAL,
12673 elfcpp::STV_HIDDEN,
12674 0, // nonvis
12675 true, // offset_is_from_end
12676 true); // only_if_ref
12677 }
12678 else
12679 {
12680 // Define __exidx_start and __exidx_end even when .ARM.exidx
12681 // section is missing to match ld's behaviour.
12682 symtab->define_as_constant("__exidx_start", NULL,
12683 Symbol_table::PREDEFINED,
12684 0, 0, elfcpp::STT_OBJECT,
12685 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12686 true, false);
12687 symtab->define_as_constant("__exidx_end", NULL,
12688 Symbol_table::PREDEFINED,
12689 0, 0, elfcpp::STT_OBJECT,
12690 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12691 true, false);
12692 }
12693 }
12694
12695 // NaCl variant. It uses different PLT contents.
12696
12697 template<bool big_endian>
12698 class Output_data_plt_arm_nacl;
12699
12700 template<bool big_endian>
12701 class Target_arm_nacl : public Target_arm<big_endian>
12702 {
12703 public:
12704 Target_arm_nacl()
12705 : Target_arm<big_endian>(&arm_nacl_info)
12706 { }
12707
12708 protected:
12709 virtual Output_data_plt_arm<big_endian>*
12710 do_make_data_plt(
12711 Layout* layout,
12712 Arm_output_data_got<big_endian>* got,
12713 Output_data_space* got_plt,
12714 Output_data_space* got_irelative)
12715 { return new Output_data_plt_arm_nacl<big_endian>(
12716 layout, got, got_plt, got_irelative); }
12717
12718 private:
12719 static const Target::Target_info arm_nacl_info;
12720 };
12721
12722 template<bool big_endian>
12723 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12724 {
12725 32, // size
12726 big_endian, // is_big_endian
12727 elfcpp::EM_ARM, // machine_code
12728 false, // has_make_symbol
12729 false, // has_resolve
12730 false, // has_code_fill
12731 true, // is_default_stack_executable
12732 false, // can_icf_inline_merge_sections
12733 '\0', // wrap_char
12734 "/lib/ld-nacl-arm.so.1", // dynamic_linker
12735 0x20000, // default_text_segment_address
12736 0x10000, // abi_pagesize (overridable by -z max-page-size)
12737 0x10000, // common_pagesize (overridable by -z common-page-size)
12738 true, // isolate_execinstr
12739 0x10000000, // rosegment_gap
12740 elfcpp::SHN_UNDEF, // small_common_shndx
12741 elfcpp::SHN_UNDEF, // large_common_shndx
12742 0, // small_common_section_flags
12743 0, // large_common_section_flags
12744 ".ARM.attributes", // attributes_section
12745 "aeabi", // attributes_vendor
12746 "_start" // entry_symbol_name
12747 };
12748
12749 template<bool big_endian>
12750 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12751 {
12752 public:
12753 Output_data_plt_arm_nacl(
12754 Layout* layout,
12755 Arm_output_data_got<big_endian>* got,
12756 Output_data_space* got_plt,
12757 Output_data_space* got_irelative)
12758 : Output_data_plt_arm<big_endian>(layout, 16, got, got_plt, got_irelative)
12759 { }
12760
12761 protected:
12762 // Return the offset of the first non-reserved PLT entry.
12763 virtual unsigned int
12764 do_first_plt_entry_offset() const
12765 { return sizeof(first_plt_entry); }
12766
12767 // Return the size of a PLT entry.
12768 virtual unsigned int
12769 do_get_plt_entry_size() const
12770 { return sizeof(plt_entry); }
12771
12772 virtual void
12773 do_fill_first_plt_entry(unsigned char* pov,
12774 Arm_address got_address,
12775 Arm_address plt_address);
12776
12777 virtual void
12778 do_fill_plt_entry(unsigned char* pov,
12779 Arm_address got_address,
12780 Arm_address plt_address,
12781 unsigned int got_offset,
12782 unsigned int plt_offset);
12783
12784 private:
12785 inline uint32_t arm_movw_immediate(uint32_t value)
12786 {
12787 return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12788 }
12789
12790 inline uint32_t arm_movt_immediate(uint32_t value)
12791 {
12792 return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12793 }
12794
12795 // Template for the first PLT entry.
12796 static const uint32_t first_plt_entry[16];
12797
12798 // Template for subsequent PLT entries.
12799 static const uint32_t plt_entry[4];
12800 };
12801
12802 // The first entry in the PLT.
12803 template<bool big_endian>
12804 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12805 {
12806 // First bundle:
12807 0xe300c000, // movw ip, #:lower16:&GOT[2]-.+8
12808 0xe340c000, // movt ip, #:upper16:&GOT[2]-.+8
12809 0xe08cc00f, // add ip, ip, pc
12810 0xe52dc008, // str ip, [sp, #-8]!
12811 // Second bundle:
12812 0xe3ccc103, // bic ip, ip, #0xc0000000
12813 0xe59cc000, // ldr ip, [ip]
12814 0xe3ccc13f, // bic ip, ip, #0xc000000f
12815 0xe12fff1c, // bx ip
12816 // Third bundle:
12817 0xe320f000, // nop
12818 0xe320f000, // nop
12819 0xe320f000, // nop
12820 // .Lplt_tail:
12821 0xe50dc004, // str ip, [sp, #-4]
12822 // Fourth bundle:
12823 0xe3ccc103, // bic ip, ip, #0xc0000000
12824 0xe59cc000, // ldr ip, [ip]
12825 0xe3ccc13f, // bic ip, ip, #0xc000000f
12826 0xe12fff1c, // bx ip
12827 };
12828
12829 template<bool big_endian>
12830 void
12831 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12832 unsigned char* pov,
12833 Arm_address got_address,
12834 Arm_address plt_address)
12835 {
12836 // Write first PLT entry. All but first two words are constants.
12837 const size_t num_first_plt_words = (sizeof(first_plt_entry)
12838 / sizeof(first_plt_entry[0]));
12839
12840 int32_t got_displacement = got_address + 8 - (plt_address + 16);
12841
12842 elfcpp::Swap<32, big_endian>::writeval
12843 (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12844 elfcpp::Swap<32, big_endian>::writeval
12845 (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12846
12847 for (size_t i = 2; i < num_first_plt_words; ++i)
12848 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12849 }
12850
12851 // Subsequent entries in the PLT.
12852
12853 template<bool big_endian>
12854 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12855 {
12856 0xe300c000, // movw ip, #:lower16:&GOT[n]-.+8
12857 0xe340c000, // movt ip, #:upper16:&GOT[n]-.+8
12858 0xe08cc00f, // add ip, ip, pc
12859 0xea000000, // b .Lplt_tail
12860 };
12861
12862 template<bool big_endian>
12863 void
12864 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12865 unsigned char* pov,
12866 Arm_address got_address,
12867 Arm_address plt_address,
12868 unsigned int got_offset,
12869 unsigned int plt_offset)
12870 {
12871 // Calculate the displacement between the PLT slot and the
12872 // common tail that's part of the special initial PLT slot.
12873 int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12874 - (plt_address + plt_offset
12875 + sizeof(plt_entry) + sizeof(uint32_t)));
12876 gold_assert((tail_displacement & 3) == 0);
12877 tail_displacement >>= 2;
12878
12879 gold_assert ((tail_displacement & 0xff000000) == 0
12880 || (-tail_displacement & 0xff000000) == 0);
12881
12882 // Calculate the displacement between the PLT slot and the entry
12883 // in the GOT. The offset accounts for the value produced by
12884 // adding to pc in the penultimate instruction of the PLT stub.
12885 const int32_t got_displacement = (got_address + got_offset
12886 - (plt_address + sizeof(plt_entry)));
12887
12888 elfcpp::Swap<32, big_endian>::writeval
12889 (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12890 elfcpp::Swap<32, big_endian>::writeval
12891 (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12892 elfcpp::Swap<32, big_endian>::writeval
12893 (pov + 8, plt_entry[2]);
12894 elfcpp::Swap<32, big_endian>::writeval
12895 (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12896 }
12897
12898 // Target selectors.
12899
12900 template<bool big_endian>
12901 class Target_selector_arm_nacl
12902 : public Target_selector_nacl<Target_selector_arm<big_endian>,
12903 Target_arm_nacl<big_endian> >
12904 {
12905 public:
12906 Target_selector_arm_nacl()
12907 : Target_selector_nacl<Target_selector_arm<big_endian>,
12908 Target_arm_nacl<big_endian> >(
12909 "arm",
12910 big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12911 big_endian ? "armelfb_nacl" : "armelf_nacl")
12912 { }
12913 };
12914
12915 Target_selector_arm_nacl<false> target_selector_arm;
12916 Target_selector_arm_nacl<true> target_selector_armbe;
12917
12918 } // End anonymous namespace.
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