ARM: Add support for value 3 of Tag_ABI_VFP_args attribute
[deliverable/binutils-gdb.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright (C) 2009-2014 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), rel_dyn_(NULL),
2123 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 // Relocate a section.
2262 void
2263 relocate_section(const Relocate_info<32, big_endian>*,
2264 unsigned int sh_type,
2265 const unsigned char* prelocs,
2266 size_t reloc_count,
2267 Output_section* output_section,
2268 bool needs_special_offset_handling,
2269 unsigned char* view,
2270 Arm_address view_address,
2271 section_size_type view_size,
2272 const Reloc_symbol_changes*);
2273
2274 // Scan the relocs during a relocatable link.
2275 void
2276 scan_relocatable_relocs(Symbol_table* symtab,
2277 Layout* layout,
2278 Sized_relobj_file<32, big_endian>* object,
2279 unsigned int data_shndx,
2280 unsigned int sh_type,
2281 const unsigned char* prelocs,
2282 size_t reloc_count,
2283 Output_section* output_section,
2284 bool needs_special_offset_handling,
2285 size_t local_symbol_count,
2286 const unsigned char* plocal_symbols,
2287 Relocatable_relocs*);
2288
2289 // Emit relocations for a section.
2290 void
2291 relocate_relocs(const Relocate_info<32, big_endian>*,
2292 unsigned int sh_type,
2293 const unsigned char* prelocs,
2294 size_t reloc_count,
2295 Output_section* output_section,
2296 typename elfcpp::Elf_types<32>::Elf_Off
2297 offset_in_output_section,
2298 const Relocatable_relocs*,
2299 unsigned char* view,
2300 Arm_address view_address,
2301 section_size_type view_size,
2302 unsigned char* reloc_view,
2303 section_size_type reloc_view_size);
2304
2305 // Perform target-specific processing in a relocatable link. This is
2306 // only used if we use the relocation strategy RELOC_SPECIAL.
2307 void
2308 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2309 unsigned int sh_type,
2310 const unsigned char* preloc_in,
2311 size_t relnum,
2312 Output_section* output_section,
2313 typename elfcpp::Elf_types<32>::Elf_Off
2314 offset_in_output_section,
2315 unsigned char* view,
2316 typename elfcpp::Elf_types<32>::Elf_Addr
2317 view_address,
2318 section_size_type view_size,
2319 unsigned char* preloc_out);
2320
2321 // Return whether SYM is defined by the ABI.
2322 bool
2323 do_is_defined_by_abi(const Symbol* sym) const
2324 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2325
2326 // Return whether there is a GOT section.
2327 bool
2328 has_got_section() const
2329 { return this->got_ != NULL; }
2330
2331 // Return the size of the GOT section.
2332 section_size_type
2333 got_size() const
2334 {
2335 gold_assert(this->got_ != NULL);
2336 return this->got_->data_size();
2337 }
2338
2339 // Return the number of entries in the GOT.
2340 unsigned int
2341 got_entry_count() const
2342 {
2343 if (!this->has_got_section())
2344 return 0;
2345 return this->got_size() / 4;
2346 }
2347
2348 // Return the number of entries in the PLT.
2349 unsigned int
2350 plt_entry_count() const;
2351
2352 // Return the offset of the first non-reserved PLT entry.
2353 unsigned int
2354 first_plt_entry_offset() const;
2355
2356 // Return the size of each PLT entry.
2357 unsigned int
2358 plt_entry_size() const;
2359
2360 // Map platform-specific reloc types
2361 static unsigned int
2362 get_real_reloc_type(unsigned int r_type);
2363
2364 //
2365 // Methods to support stub-generations.
2366 //
2367
2368 // Return the stub factory
2369 const Stub_factory&
2370 stub_factory() const
2371 { return this->stub_factory_; }
2372
2373 // Make a new Arm_input_section object.
2374 Arm_input_section<big_endian>*
2375 new_arm_input_section(Relobj*, unsigned int);
2376
2377 // Find the Arm_input_section object corresponding to the SHNDX-th input
2378 // section of RELOBJ.
2379 Arm_input_section<big_endian>*
2380 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2381
2382 // Make a new Stub_table
2383 Stub_table<big_endian>*
2384 new_stub_table(Arm_input_section<big_endian>*);
2385
2386 // Scan a section for stub generation.
2387 void
2388 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2389 const unsigned char*, size_t, Output_section*,
2390 bool, const unsigned char*, Arm_address,
2391 section_size_type);
2392
2393 // Relocate a stub.
2394 void
2395 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2396 Output_section*, unsigned char*, Arm_address,
2397 section_size_type);
2398
2399 // Get the default ARM target.
2400 static Target_arm<big_endian>*
2401 default_target()
2402 {
2403 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2404 && parameters->target().is_big_endian() == big_endian);
2405 return static_cast<Target_arm<big_endian>*>(
2406 parameters->sized_target<32, big_endian>());
2407 }
2408
2409 // Whether NAME belongs to a mapping symbol.
2410 static bool
2411 is_mapping_symbol_name(const char* name)
2412 {
2413 return (name
2414 && name[0] == '$'
2415 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2416 && (name[2] == '\0' || name[2] == '.'));
2417 }
2418
2419 // Whether we work around the Cortex-A8 erratum.
2420 bool
2421 fix_cortex_a8() const
2422 { return this->fix_cortex_a8_; }
2423
2424 // Whether we merge exidx entries in debuginfo.
2425 bool
2426 merge_exidx_entries() const
2427 { return parameters->options().merge_exidx_entries(); }
2428
2429 // Whether we fix R_ARM_V4BX relocation.
2430 // 0 - do not fix
2431 // 1 - replace with MOV instruction (armv4 target)
2432 // 2 - make interworking veneer (>= armv4t targets only)
2433 General_options::Fix_v4bx
2434 fix_v4bx() const
2435 { return parameters->options().fix_v4bx(); }
2436
2437 // Scan a span of THUMB code section for Cortex-A8 erratum.
2438 void
2439 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2440 section_size_type, section_size_type,
2441 const unsigned char*, Arm_address);
2442
2443 // Apply Cortex-A8 workaround to a branch.
2444 void
2445 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2446 unsigned char*, Arm_address);
2447
2448 protected:
2449 // Make the PLT-generator object.
2450 Output_data_plt_arm<big_endian>*
2451 make_data_plt(Layout* layout, Output_data_space* got_plt)
2452 { return this->do_make_data_plt(layout, got_plt); }
2453
2454 // Make an ELF object.
2455 Object*
2456 do_make_elf_object(const std::string&, Input_file*, off_t,
2457 const elfcpp::Ehdr<32, big_endian>& ehdr);
2458
2459 Object*
2460 do_make_elf_object(const std::string&, Input_file*, off_t,
2461 const elfcpp::Ehdr<32, !big_endian>&)
2462 { gold_unreachable(); }
2463
2464 Object*
2465 do_make_elf_object(const std::string&, Input_file*, off_t,
2466 const elfcpp::Ehdr<64, false>&)
2467 { gold_unreachable(); }
2468
2469 Object*
2470 do_make_elf_object(const std::string&, Input_file*, off_t,
2471 const elfcpp::Ehdr<64, true>&)
2472 { gold_unreachable(); }
2473
2474 // Make an output section.
2475 Output_section*
2476 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2477 elfcpp::Elf_Xword flags)
2478 { return new Arm_output_section<big_endian>(name, type, flags); }
2479
2480 void
2481 do_adjust_elf_header(unsigned char* view, int len);
2482
2483 // We only need to generate stubs, and hence perform relaxation if we are
2484 // not doing relocatable linking.
2485 bool
2486 do_may_relax() const
2487 { return !parameters->options().relocatable(); }
2488
2489 bool
2490 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2491
2492 // Determine whether an object attribute tag takes an integer, a
2493 // string or both.
2494 int
2495 do_attribute_arg_type(int tag) const;
2496
2497 // Reorder tags during output.
2498 int
2499 do_attributes_order(int num) const;
2500
2501 // This is called when the target is selected as the default.
2502 void
2503 do_select_as_default_target()
2504 {
2505 // No locking is required since there should only be one default target.
2506 // We cannot have both the big-endian and little-endian ARM targets
2507 // as the default.
2508 gold_assert(arm_reloc_property_table == NULL);
2509 arm_reloc_property_table = new Arm_reloc_property_table();
2510 }
2511
2512 // Virtual function which is set to return true by a target if
2513 // it can use relocation types to determine if a function's
2514 // pointer is taken.
2515 virtual bool
2516 do_can_check_for_function_pointers() const
2517 { return true; }
2518
2519 // Whether a section called SECTION_NAME may have function pointers to
2520 // sections not eligible for safe ICF folding.
2521 virtual bool
2522 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2523 {
2524 return (!is_prefix_of(".ARM.exidx", section_name)
2525 && !is_prefix_of(".ARM.extab", section_name)
2526 && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2527 }
2528
2529 virtual void
2530 do_define_standard_symbols(Symbol_table*, Layout*);
2531
2532 virtual Output_data_plt_arm<big_endian>*
2533 do_make_data_plt(Layout* layout, Output_data_space* got_plt)
2534 {
2535 return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
2536 }
2537
2538 private:
2539 // The class which scans relocations.
2540 class Scan
2541 {
2542 public:
2543 Scan()
2544 : issued_non_pic_error_(false)
2545 { }
2546
2547 static inline int
2548 get_reference_flags(unsigned int r_type);
2549
2550 inline void
2551 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2552 Sized_relobj_file<32, big_endian>* object,
2553 unsigned int data_shndx,
2554 Output_section* output_section,
2555 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2556 const elfcpp::Sym<32, big_endian>& lsym,
2557 bool is_discarded);
2558
2559 inline void
2560 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2561 Sized_relobj_file<32, big_endian>* object,
2562 unsigned int data_shndx,
2563 Output_section* output_section,
2564 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2565 Symbol* gsym);
2566
2567 inline bool
2568 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2569 Sized_relobj_file<32, big_endian>* ,
2570 unsigned int ,
2571 Output_section* ,
2572 const elfcpp::Rel<32, big_endian>& ,
2573 unsigned int ,
2574 const elfcpp::Sym<32, big_endian>&);
2575
2576 inline bool
2577 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2578 Sized_relobj_file<32, big_endian>* ,
2579 unsigned int ,
2580 Output_section* ,
2581 const elfcpp::Rel<32, big_endian>& ,
2582 unsigned int , Symbol*);
2583
2584 private:
2585 static void
2586 unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2587 unsigned int r_type);
2588
2589 static void
2590 unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2591 unsigned int r_type, Symbol*);
2592
2593 void
2594 check_non_pic(Relobj*, unsigned int r_type);
2595
2596 // Almost identical to Symbol::needs_plt_entry except that it also
2597 // handles STT_ARM_TFUNC.
2598 static bool
2599 symbol_needs_plt_entry(const Symbol* sym)
2600 {
2601 // An undefined symbol from an executable does not need a PLT entry.
2602 if (sym->is_undefined() && !parameters->options().shared())
2603 return false;
2604
2605 return (!parameters->doing_static_link()
2606 && (sym->type() == elfcpp::STT_FUNC
2607 || sym->type() == elfcpp::STT_ARM_TFUNC)
2608 && (sym->is_from_dynobj()
2609 || sym->is_undefined()
2610 || sym->is_preemptible()));
2611 }
2612
2613 inline bool
2614 possible_function_pointer_reloc(unsigned int r_type);
2615
2616 // Whether we have issued an error about a non-PIC compilation.
2617 bool issued_non_pic_error_;
2618 };
2619
2620 // The class which implements relocation.
2621 class Relocate
2622 {
2623 public:
2624 Relocate()
2625 { }
2626
2627 ~Relocate()
2628 { }
2629
2630 // Return whether the static relocation needs to be applied.
2631 inline bool
2632 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2633 unsigned int r_type,
2634 bool is_32bit,
2635 Output_section* output_section);
2636
2637 // Do a relocation. Return false if the caller should not issue
2638 // any warnings about this relocation.
2639 inline bool
2640 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2641 Output_section*, size_t relnum,
2642 const elfcpp::Rel<32, big_endian>&,
2643 unsigned int r_type, const Sized_symbol<32>*,
2644 const Symbol_value<32>*,
2645 unsigned char*, Arm_address,
2646 section_size_type);
2647
2648 // Return whether we want to pass flag NON_PIC_REF for this
2649 // reloc. This means the relocation type accesses a symbol not via
2650 // GOT or PLT.
2651 static inline bool
2652 reloc_is_non_pic(unsigned int r_type)
2653 {
2654 switch (r_type)
2655 {
2656 // These relocation types reference GOT or PLT entries explicitly.
2657 case elfcpp::R_ARM_GOT_BREL:
2658 case elfcpp::R_ARM_GOT_ABS:
2659 case elfcpp::R_ARM_GOT_PREL:
2660 case elfcpp::R_ARM_GOT_BREL12:
2661 case elfcpp::R_ARM_PLT32_ABS:
2662 case elfcpp::R_ARM_TLS_GD32:
2663 case elfcpp::R_ARM_TLS_LDM32:
2664 case elfcpp::R_ARM_TLS_IE32:
2665 case elfcpp::R_ARM_TLS_IE12GP:
2666
2667 // These relocate types may use PLT entries.
2668 case elfcpp::R_ARM_CALL:
2669 case elfcpp::R_ARM_THM_CALL:
2670 case elfcpp::R_ARM_JUMP24:
2671 case elfcpp::R_ARM_THM_JUMP24:
2672 case elfcpp::R_ARM_THM_JUMP19:
2673 case elfcpp::R_ARM_PLT32:
2674 case elfcpp::R_ARM_THM_XPC22:
2675 case elfcpp::R_ARM_PREL31:
2676 case elfcpp::R_ARM_SBREL31:
2677 return false;
2678
2679 default:
2680 return true;
2681 }
2682 }
2683
2684 private:
2685 // Do a TLS relocation.
2686 inline typename Arm_relocate_functions<big_endian>::Status
2687 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2688 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2689 const Sized_symbol<32>*, const Symbol_value<32>*,
2690 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2691 section_size_type);
2692
2693 };
2694
2695 // A class which returns the size required for a relocation type,
2696 // used while scanning relocs during a relocatable link.
2697 class Relocatable_size_for_reloc
2698 {
2699 public:
2700 unsigned int
2701 get_size_for_reloc(unsigned int, Relobj*);
2702 };
2703
2704 // Adjust TLS relocation type based on the options and whether this
2705 // is a local symbol.
2706 static tls::Tls_optimization
2707 optimize_tls_reloc(bool is_final, int r_type);
2708
2709 // Get the GOT section, creating it if necessary.
2710 Arm_output_data_got<big_endian>*
2711 got_section(Symbol_table*, Layout*);
2712
2713 // Get the GOT PLT section.
2714 Output_data_space*
2715 got_plt_section() const
2716 {
2717 gold_assert(this->got_plt_ != NULL);
2718 return this->got_plt_;
2719 }
2720
2721 // Create a PLT entry for a global symbol.
2722 void
2723 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2724
2725 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2726 void
2727 define_tls_base_symbol(Symbol_table*, Layout*);
2728
2729 // Create a GOT entry for the TLS module index.
2730 unsigned int
2731 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2732 Sized_relobj_file<32, big_endian>* object);
2733
2734 // Get the PLT section.
2735 const Output_data_plt_arm<big_endian>*
2736 plt_section() const
2737 {
2738 gold_assert(this->plt_ != NULL);
2739 return this->plt_;
2740 }
2741
2742 // Get the dynamic reloc section, creating it if necessary.
2743 Reloc_section*
2744 rel_dyn_section(Layout*);
2745
2746 // Get the section to use for TLS_DESC relocations.
2747 Reloc_section*
2748 rel_tls_desc_section(Layout*) const;
2749
2750 // Return true if the symbol may need a COPY relocation.
2751 // References from an executable object to non-function symbols
2752 // defined in a dynamic object may need a COPY relocation.
2753 bool
2754 may_need_copy_reloc(Symbol* gsym)
2755 {
2756 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2757 && gsym->may_need_copy_reloc());
2758 }
2759
2760 // Add a potential copy relocation.
2761 void
2762 copy_reloc(Symbol_table* symtab, Layout* layout,
2763 Sized_relobj_file<32, big_endian>* object,
2764 unsigned int shndx, Output_section* output_section,
2765 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2766 {
2767 this->copy_relocs_.copy_reloc(symtab, layout,
2768 symtab->get_sized_symbol<32>(sym),
2769 object, shndx, output_section, reloc,
2770 this->rel_dyn_section(layout));
2771 }
2772
2773 // Whether two EABI versions are compatible.
2774 static bool
2775 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2776
2777 // Merge processor-specific flags from input object and those in the ELF
2778 // header of the output.
2779 void
2780 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2781
2782 // Get the secondary compatible architecture.
2783 static int
2784 get_secondary_compatible_arch(const Attributes_section_data*);
2785
2786 // Set the secondary compatible architecture.
2787 static void
2788 set_secondary_compatible_arch(Attributes_section_data*, int);
2789
2790 static int
2791 tag_cpu_arch_combine(const char*, int, int*, int, int);
2792
2793 // Helper to print AEABI enum tag value.
2794 static std::string
2795 aeabi_enum_name(unsigned int);
2796
2797 // Return string value for TAG_CPU_name.
2798 static std::string
2799 tag_cpu_name_value(unsigned int);
2800
2801 // Query attributes object to see if integer divide instructions may be
2802 // present in an object.
2803 static bool
2804 attributes_accept_div(int arch, int profile,
2805 const Object_attribute* div_attr);
2806
2807 // Query attributes object to see if integer divide instructions are
2808 // forbidden to be in the object. This is not the inverse of
2809 // attributes_accept_div.
2810 static bool
2811 attributes_forbid_div(const Object_attribute* div_attr);
2812
2813 // Merge object attributes from input object and those in the output.
2814 void
2815 merge_object_attributes(const char*, const Attributes_section_data*);
2816
2817 // Helper to get an AEABI object attribute
2818 Object_attribute*
2819 get_aeabi_object_attribute(int tag) const
2820 {
2821 Attributes_section_data* pasd = this->attributes_section_data_;
2822 gold_assert(pasd != NULL);
2823 Object_attribute* attr =
2824 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2825 gold_assert(attr != NULL);
2826 return attr;
2827 }
2828
2829 //
2830 // Methods to support stub-generations.
2831 //
2832
2833 // Group input sections for stub generation.
2834 void
2835 group_sections(Layout*, section_size_type, bool, const Task*);
2836
2837 // Scan a relocation for stub generation.
2838 void
2839 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2840 const Sized_symbol<32>*, unsigned int,
2841 const Symbol_value<32>*,
2842 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2843
2844 // Scan a relocation section for stub.
2845 template<int sh_type>
2846 void
2847 scan_reloc_section_for_stubs(
2848 const Relocate_info<32, big_endian>* relinfo,
2849 const unsigned char* prelocs,
2850 size_t reloc_count,
2851 Output_section* output_section,
2852 bool needs_special_offset_handling,
2853 const unsigned char* view,
2854 elfcpp::Elf_types<32>::Elf_Addr view_address,
2855 section_size_type);
2856
2857 // Fix .ARM.exidx section coverage.
2858 void
2859 fix_exidx_coverage(Layout*, const Input_objects*,
2860 Arm_output_section<big_endian>*, Symbol_table*,
2861 const Task*);
2862
2863 // Functors for STL set.
2864 struct output_section_address_less_than
2865 {
2866 bool
2867 operator()(const Output_section* s1, const Output_section* s2) const
2868 { return s1->address() < s2->address(); }
2869 };
2870
2871 // Information about this specific target which we pass to the
2872 // general Target structure.
2873 static const Target::Target_info arm_info;
2874
2875 // The types of GOT entries needed for this platform.
2876 // These values are exposed to the ABI in an incremental link.
2877 // Do not renumber existing values without changing the version
2878 // number of the .gnu_incremental_inputs section.
2879 enum Got_type
2880 {
2881 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2882 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2883 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2884 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2885 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2886 };
2887
2888 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2889
2890 // Map input section to Arm_input_section.
2891 typedef Unordered_map<Section_id,
2892 Arm_input_section<big_endian>*,
2893 Section_id_hash>
2894 Arm_input_section_map;
2895
2896 // Map output addresses to relocs for Cortex-A8 erratum.
2897 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2898 Cortex_a8_relocs_info;
2899
2900 // The GOT section.
2901 Arm_output_data_got<big_endian>* got_;
2902 // The PLT section.
2903 Output_data_plt_arm<big_endian>* plt_;
2904 // The GOT PLT section.
2905 Output_data_space* got_plt_;
2906 // The dynamic reloc section.
2907 Reloc_section* rel_dyn_;
2908 // Relocs saved to avoid a COPY reloc.
2909 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2910 // Offset of the GOT entry for the TLS module index.
2911 unsigned int got_mod_index_offset_;
2912 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2913 bool tls_base_symbol_defined_;
2914 // Vector of Stub_tables created.
2915 Stub_table_list stub_tables_;
2916 // Stub factory.
2917 const Stub_factory &stub_factory_;
2918 // Whether we force PIC branch veneers.
2919 bool should_force_pic_veneer_;
2920 // Map for locating Arm_input_sections.
2921 Arm_input_section_map arm_input_section_map_;
2922 // Attributes section data in output.
2923 Attributes_section_data* attributes_section_data_;
2924 // Whether we want to fix code for Cortex-A8 erratum.
2925 bool fix_cortex_a8_;
2926 // Map addresses to relocs for Cortex-A8 erratum.
2927 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2928 };
2929
2930 template<bool big_endian>
2931 const Target::Target_info Target_arm<big_endian>::arm_info =
2932 {
2933 32, // size
2934 big_endian, // is_big_endian
2935 elfcpp::EM_ARM, // machine_code
2936 false, // has_make_symbol
2937 false, // has_resolve
2938 false, // has_code_fill
2939 true, // is_default_stack_executable
2940 false, // can_icf_inline_merge_sections
2941 '\0', // wrap_char
2942 "/usr/lib/libc.so.1", // dynamic_linker
2943 0x8000, // default_text_segment_address
2944 0x1000, // abi_pagesize (overridable by -z max-page-size)
2945 0x1000, // common_pagesize (overridable by -z common-page-size)
2946 false, // isolate_execinstr
2947 0, // rosegment_gap
2948 elfcpp::SHN_UNDEF, // small_common_shndx
2949 elfcpp::SHN_UNDEF, // large_common_shndx
2950 0, // small_common_section_flags
2951 0, // large_common_section_flags
2952 ".ARM.attributes", // attributes_section
2953 "aeabi", // attributes_vendor
2954 "_start" // entry_symbol_name
2955 };
2956
2957 // Arm relocate functions class
2958 //
2959
2960 template<bool big_endian>
2961 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2962 {
2963 public:
2964 typedef enum
2965 {
2966 STATUS_OKAY, // No error during relocation.
2967 STATUS_OVERFLOW, // Relocation overflow.
2968 STATUS_BAD_RELOC // Relocation cannot be applied.
2969 } Status;
2970
2971 private:
2972 typedef Relocate_functions<32, big_endian> Base;
2973 typedef Arm_relocate_functions<big_endian> This;
2974
2975 // Encoding of imm16 argument for movt and movw ARM instructions
2976 // from ARM ARM:
2977 //
2978 // imm16 := imm4 | imm12
2979 //
2980 // 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
2981 // +-------+---------------+-------+-------+-----------------------+
2982 // | | |imm4 | |imm12 |
2983 // +-------+---------------+-------+-------+-----------------------+
2984
2985 // Extract the relocation addend from VAL based on the ARM
2986 // instruction encoding described above.
2987 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2988 extract_arm_movw_movt_addend(
2989 typename elfcpp::Swap<32, big_endian>::Valtype val)
2990 {
2991 // According to the Elf ABI for ARM Architecture the immediate
2992 // field is sign-extended to form the addend.
2993 return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2994 }
2995
2996 // Insert X into VAL based on the ARM instruction encoding described
2997 // above.
2998 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2999 insert_val_arm_movw_movt(
3000 typename elfcpp::Swap<32, big_endian>::Valtype val,
3001 typename elfcpp::Swap<32, big_endian>::Valtype x)
3002 {
3003 val &= 0xfff0f000;
3004 val |= x & 0x0fff;
3005 val |= (x & 0xf000) << 4;
3006 return val;
3007 }
3008
3009 // Encoding of imm16 argument for movt and movw Thumb2 instructions
3010 // from ARM ARM:
3011 //
3012 // imm16 := imm4 | i | imm3 | imm8
3013 //
3014 // 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
3015 // +---------+-+-----------+-------++-+-----+-------+---------------+
3016 // | |i| |imm4 || |imm3 | |imm8 |
3017 // +---------+-+-----------+-------++-+-----+-------+---------------+
3018
3019 // Extract the relocation addend from VAL based on the Thumb2
3020 // instruction encoding described above.
3021 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3022 extract_thumb_movw_movt_addend(
3023 typename elfcpp::Swap<32, big_endian>::Valtype val)
3024 {
3025 // According to the Elf ABI for ARM Architecture the immediate
3026 // field is sign-extended to form the addend.
3027 return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3028 | ((val >> 15) & 0x0800)
3029 | ((val >> 4) & 0x0700)
3030 | (val & 0x00ff));
3031 }
3032
3033 // Insert X into VAL based on the Thumb2 instruction encoding
3034 // described above.
3035 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3036 insert_val_thumb_movw_movt(
3037 typename elfcpp::Swap<32, big_endian>::Valtype val,
3038 typename elfcpp::Swap<32, big_endian>::Valtype x)
3039 {
3040 val &= 0xfbf08f00;
3041 val |= (x & 0xf000) << 4;
3042 val |= (x & 0x0800) << 15;
3043 val |= (x & 0x0700) << 4;
3044 val |= (x & 0x00ff);
3045 return val;
3046 }
3047
3048 // Calculate the smallest constant Kn for the specified residual.
3049 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3050 static uint32_t
3051 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3052 {
3053 int32_t msb;
3054
3055 if (residual == 0)
3056 return 0;
3057 // Determine the most significant bit in the residual and
3058 // align the resulting value to a 2-bit boundary.
3059 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3060 ;
3061 // The desired shift is now (msb - 6), or zero, whichever
3062 // is the greater.
3063 return (((msb - 6) < 0) ? 0 : (msb - 6));
3064 }
3065
3066 // Calculate the final residual for the specified group index.
3067 // If the passed group index is less than zero, the method will return
3068 // the value of the specified residual without any change.
3069 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3070 static typename elfcpp::Swap<32, big_endian>::Valtype
3071 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3072 const int group)
3073 {
3074 for (int n = 0; n <= group; n++)
3075 {
3076 // Calculate which part of the value to mask.
3077 uint32_t shift = calc_grp_kn(residual);
3078 // Calculate the residual for the next time around.
3079 residual &= ~(residual & (0xff << shift));
3080 }
3081
3082 return residual;
3083 }
3084
3085 // Calculate the value of Gn for the specified group index.
3086 // We return it in the form of an encoded constant-and-rotation.
3087 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3088 static typename elfcpp::Swap<32, big_endian>::Valtype
3089 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3090 const int group)
3091 {
3092 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3093 uint32_t shift = 0;
3094
3095 for (int n = 0; n <= group; n++)
3096 {
3097 // Calculate which part of the value to mask.
3098 shift = calc_grp_kn(residual);
3099 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3100 gn = residual & (0xff << shift);
3101 // Calculate the residual for the next time around.
3102 residual &= ~gn;
3103 }
3104 // Return Gn in the form of an encoded constant-and-rotation.
3105 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3106 }
3107
3108 public:
3109 // Handle ARM long branches.
3110 static typename This::Status
3111 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3112 unsigned char*, const Sized_symbol<32>*,
3113 const Arm_relobj<big_endian>*, unsigned int,
3114 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3115
3116 // Handle THUMB long branches.
3117 static typename This::Status
3118 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3119 unsigned char*, const Sized_symbol<32>*,
3120 const Arm_relobj<big_endian>*, unsigned int,
3121 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3122
3123
3124 // Return the branch offset of a 32-bit THUMB branch.
3125 static inline int32_t
3126 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3127 {
3128 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3129 // involving the J1 and J2 bits.
3130 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3131 uint32_t upper = upper_insn & 0x3ffU;
3132 uint32_t lower = lower_insn & 0x7ffU;
3133 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3134 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3135 uint32_t i1 = j1 ^ s ? 0 : 1;
3136 uint32_t i2 = j2 ^ s ? 0 : 1;
3137
3138 return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3139 | (upper << 12) | (lower << 1));
3140 }
3141
3142 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3143 // UPPER_INSN is the original upper instruction of the branch. Caller is
3144 // responsible for overflow checking and BLX offset adjustment.
3145 static inline uint16_t
3146 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3147 {
3148 uint32_t s = offset < 0 ? 1 : 0;
3149 uint32_t bits = static_cast<uint32_t>(offset);
3150 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3151 }
3152
3153 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3154 // LOWER_INSN is the original lower instruction of the branch. Caller is
3155 // responsible for overflow checking and BLX offset adjustment.
3156 static inline uint16_t
3157 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3158 {
3159 uint32_t s = offset < 0 ? 1 : 0;
3160 uint32_t bits = static_cast<uint32_t>(offset);
3161 return ((lower_insn & ~0x2fffU)
3162 | ((((bits >> 23) & 1) ^ !s) << 13)
3163 | ((((bits >> 22) & 1) ^ !s) << 11)
3164 | ((bits >> 1) & 0x7ffU));
3165 }
3166
3167 // Return the branch offset of a 32-bit THUMB conditional branch.
3168 static inline int32_t
3169 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3170 {
3171 uint32_t s = (upper_insn & 0x0400U) >> 10;
3172 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3173 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3174 uint32_t lower = (lower_insn & 0x07ffU);
3175 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3176
3177 return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3178 }
3179
3180 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3181 // instruction. UPPER_INSN is the original upper instruction of the branch.
3182 // Caller is responsible for overflow checking.
3183 static inline uint16_t
3184 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3185 {
3186 uint32_t s = offset < 0 ? 1 : 0;
3187 uint32_t bits = static_cast<uint32_t>(offset);
3188 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3189 }
3190
3191 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3192 // instruction. LOWER_INSN is the original lower instruction of the branch.
3193 // The caller is responsible for overflow checking.
3194 static inline uint16_t
3195 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3196 {
3197 uint32_t bits = static_cast<uint32_t>(offset);
3198 uint32_t j2 = (bits & 0x00080000U) >> 19;
3199 uint32_t j1 = (bits & 0x00040000U) >> 18;
3200 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3201
3202 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3203 }
3204
3205 // R_ARM_ABS8: S + A
3206 static inline typename This::Status
3207 abs8(unsigned char* view,
3208 const Sized_relobj_file<32, big_endian>* object,
3209 const Symbol_value<32>* psymval)
3210 {
3211 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3212 Valtype* wv = reinterpret_cast<Valtype*>(view);
3213 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3214 int32_t addend = Bits<8>::sign_extend32(val);
3215 Arm_address x = psymval->value(object, addend);
3216 val = Bits<32>::bit_select32(val, x, 0xffU);
3217 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3218
3219 // R_ARM_ABS8 permits signed or unsigned results.
3220 return (Bits<8>::has_signed_unsigned_overflow32(x)
3221 ? This::STATUS_OVERFLOW
3222 : This::STATUS_OKAY);
3223 }
3224
3225 // R_ARM_THM_ABS5: S + A
3226 static inline typename This::Status
3227 thm_abs5(unsigned char* view,
3228 const Sized_relobj_file<32, big_endian>* object,
3229 const Symbol_value<32>* psymval)
3230 {
3231 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3232 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3233 Valtype* wv = reinterpret_cast<Valtype*>(view);
3234 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3235 Reltype addend = (val & 0x7e0U) >> 6;
3236 Reltype x = psymval->value(object, addend);
3237 val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3238 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3239 return (Bits<5>::has_overflow32(x)
3240 ? This::STATUS_OVERFLOW
3241 : This::STATUS_OKAY);
3242 }
3243
3244 // R_ARM_ABS12: S + A
3245 static inline typename This::Status
3246 abs12(unsigned char* view,
3247 const Sized_relobj_file<32, big_endian>* object,
3248 const Symbol_value<32>* psymval)
3249 {
3250 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3251 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3252 Valtype* wv = reinterpret_cast<Valtype*>(view);
3253 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3254 Reltype addend = val & 0x0fffU;
3255 Reltype x = psymval->value(object, addend);
3256 val = Bits<32>::bit_select32(val, x, 0x0fffU);
3257 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3258 return (Bits<12>::has_overflow32(x)
3259 ? This::STATUS_OVERFLOW
3260 : This::STATUS_OKAY);
3261 }
3262
3263 // R_ARM_ABS16: S + A
3264 static inline typename This::Status
3265 abs16(unsigned char* view,
3266 const Sized_relobj_file<32, big_endian>* object,
3267 const Symbol_value<32>* psymval)
3268 {
3269 typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3270 Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3271 int32_t addend = Bits<16>::sign_extend32(val);
3272 Arm_address x = psymval->value(object, addend);
3273 val = Bits<32>::bit_select32(val, x, 0xffffU);
3274 elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3275
3276 // R_ARM_ABS16 permits signed or unsigned results.
3277 return (Bits<16>::has_signed_unsigned_overflow32(x)
3278 ? This::STATUS_OVERFLOW
3279 : This::STATUS_OKAY);
3280 }
3281
3282 // R_ARM_ABS32: (S + A) | T
3283 static inline typename This::Status
3284 abs32(unsigned char* view,
3285 const Sized_relobj_file<32, big_endian>* object,
3286 const Symbol_value<32>* psymval,
3287 Arm_address thumb_bit)
3288 {
3289 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3290 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3291 Valtype x = psymval->value(object, addend) | thumb_bit;
3292 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3293 return This::STATUS_OKAY;
3294 }
3295
3296 // R_ARM_REL32: (S + A) | T - P
3297 static inline typename This::Status
3298 rel32(unsigned char* view,
3299 const Sized_relobj_file<32, big_endian>* object,
3300 const Symbol_value<32>* psymval,
3301 Arm_address address,
3302 Arm_address thumb_bit)
3303 {
3304 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3305 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3306 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3307 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3308 return This::STATUS_OKAY;
3309 }
3310
3311 // R_ARM_THM_JUMP24: (S + A) | T - P
3312 static typename This::Status
3313 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3314 const Symbol_value<32>* psymval, Arm_address address,
3315 Arm_address thumb_bit);
3316
3317 // R_ARM_THM_JUMP6: S + A – P
3318 static inline typename This::Status
3319 thm_jump6(unsigned char* view,
3320 const Sized_relobj_file<32, big_endian>* object,
3321 const Symbol_value<32>* psymval,
3322 Arm_address address)
3323 {
3324 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3325 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3326 Valtype* wv = reinterpret_cast<Valtype*>(view);
3327 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3328 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3329 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3330 Reltype x = (psymval->value(object, addend) - address);
3331 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3332 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3333 // CZB does only forward jumps.
3334 return ((x > 0x007e)
3335 ? This::STATUS_OVERFLOW
3336 : This::STATUS_OKAY);
3337 }
3338
3339 // R_ARM_THM_JUMP8: S + A – P
3340 static inline typename This::Status
3341 thm_jump8(unsigned char* view,
3342 const Sized_relobj_file<32, big_endian>* object,
3343 const Symbol_value<32>* psymval,
3344 Arm_address address)
3345 {
3346 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3347 Valtype* wv = reinterpret_cast<Valtype*>(view);
3348 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3349 int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3350 int32_t x = (psymval->value(object, addend) - address);
3351 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3352 | ((x & 0x01fe) >> 1)));
3353 // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3354 return (Bits<9>::has_overflow32(x)
3355 ? This::STATUS_OVERFLOW
3356 : This::STATUS_OKAY);
3357 }
3358
3359 // R_ARM_THM_JUMP11: S + A – P
3360 static inline typename This::Status
3361 thm_jump11(unsigned char* view,
3362 const Sized_relobj_file<32, big_endian>* object,
3363 const Symbol_value<32>* psymval,
3364 Arm_address address)
3365 {
3366 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3367 Valtype* wv = reinterpret_cast<Valtype*>(view);
3368 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3369 int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3370 int32_t x = (psymval->value(object, addend) - address);
3371 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3372 | ((x & 0x0ffe) >> 1)));
3373 // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3374 return (Bits<12>::has_overflow32(x)
3375 ? This::STATUS_OVERFLOW
3376 : This::STATUS_OKAY);
3377 }
3378
3379 // R_ARM_BASE_PREL: B(S) + A - P
3380 static inline typename This::Status
3381 base_prel(unsigned char* view,
3382 Arm_address origin,
3383 Arm_address address)
3384 {
3385 Base::rel32(view, origin - address);
3386 return STATUS_OKAY;
3387 }
3388
3389 // R_ARM_BASE_ABS: B(S) + A
3390 static inline typename This::Status
3391 base_abs(unsigned char* view,
3392 Arm_address origin)
3393 {
3394 Base::rel32(view, origin);
3395 return STATUS_OKAY;
3396 }
3397
3398 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3399 static inline typename This::Status
3400 got_brel(unsigned char* view,
3401 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3402 {
3403 Base::rel32(view, got_offset);
3404 return This::STATUS_OKAY;
3405 }
3406
3407 // R_ARM_GOT_PREL: GOT(S) + A - P
3408 static inline typename This::Status
3409 got_prel(unsigned char* view,
3410 Arm_address got_entry,
3411 Arm_address address)
3412 {
3413 Base::rel32(view, got_entry - address);
3414 return This::STATUS_OKAY;
3415 }
3416
3417 // R_ARM_PREL: (S + A) | T - P
3418 static inline typename This::Status
3419 prel31(unsigned char* view,
3420 const Sized_relobj_file<32, big_endian>* object,
3421 const Symbol_value<32>* psymval,
3422 Arm_address address,
3423 Arm_address thumb_bit)
3424 {
3425 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3426 Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3427 Valtype addend = Bits<31>::sign_extend32(val);
3428 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3429 val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3430 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3431 return (Bits<31>::has_overflow32(x)
3432 ? This::STATUS_OVERFLOW
3433 : This::STATUS_OKAY);
3434 }
3435
3436 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3437 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3438 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3439 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3440 static inline typename This::Status
3441 movw(unsigned char* view,
3442 const Sized_relobj_file<32, big_endian>* object,
3443 const Symbol_value<32>* psymval,
3444 Arm_address relative_address_base,
3445 Arm_address thumb_bit,
3446 bool check_overflow)
3447 {
3448 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3449 Valtype* wv = reinterpret_cast<Valtype*>(view);
3450 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3451 Valtype addend = This::extract_arm_movw_movt_addend(val);
3452 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3453 - relative_address_base);
3454 val = This::insert_val_arm_movw_movt(val, x);
3455 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3456 return ((check_overflow && Bits<16>::has_overflow32(x))
3457 ? This::STATUS_OVERFLOW
3458 : This::STATUS_OKAY);
3459 }
3460
3461 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3462 // R_ARM_MOVT_PREL: S + A - P
3463 // R_ARM_MOVT_BREL: S + A - B(S)
3464 static inline typename This::Status
3465 movt(unsigned char* view,
3466 const Sized_relobj_file<32, big_endian>* object,
3467 const Symbol_value<32>* psymval,
3468 Arm_address relative_address_base)
3469 {
3470 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3471 Valtype* wv = reinterpret_cast<Valtype*>(view);
3472 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3473 Valtype addend = This::extract_arm_movw_movt_addend(val);
3474 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3475 val = This::insert_val_arm_movw_movt(val, x);
3476 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3477 // FIXME: IHI0044D says that we should check for overflow.
3478 return This::STATUS_OKAY;
3479 }
3480
3481 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3482 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3483 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3484 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3485 static inline typename This::Status
3486 thm_movw(unsigned char* view,
3487 const Sized_relobj_file<32, big_endian>* object,
3488 const Symbol_value<32>* psymval,
3489 Arm_address relative_address_base,
3490 Arm_address thumb_bit,
3491 bool check_overflow)
3492 {
3493 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3494 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3495 Valtype* wv = reinterpret_cast<Valtype*>(view);
3496 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3497 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3498 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3499 Reltype x =
3500 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3501 val = This::insert_val_thumb_movw_movt(val, x);
3502 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3503 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3504 return ((check_overflow && Bits<16>::has_overflow32(x))
3505 ? This::STATUS_OVERFLOW
3506 : This::STATUS_OKAY);
3507 }
3508
3509 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3510 // R_ARM_THM_MOVT_PREL: S + A - P
3511 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3512 static inline typename This::Status
3513 thm_movt(unsigned char* view,
3514 const Sized_relobj_file<32, big_endian>* object,
3515 const Symbol_value<32>* psymval,
3516 Arm_address relative_address_base)
3517 {
3518 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3519 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3520 Valtype* wv = reinterpret_cast<Valtype*>(view);
3521 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3522 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3523 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3524 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3525 val = This::insert_val_thumb_movw_movt(val, x);
3526 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3527 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3528 return This::STATUS_OKAY;
3529 }
3530
3531 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3532 static inline typename This::Status
3533 thm_alu11(unsigned char* view,
3534 const Sized_relobj_file<32, big_endian>* object,
3535 const Symbol_value<32>* psymval,
3536 Arm_address address,
3537 Arm_address thumb_bit)
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 insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3543 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3544
3545 // 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
3546 // -----------------------------------------------------------------------
3547 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3548 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3549 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3550 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3551 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3552 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3553
3554 // Determine a sign for the addend.
3555 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3556 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3557 // Thumb2 addend encoding:
3558 // imm12 := i | imm3 | imm8
3559 int32_t addend = (insn & 0xff)
3560 | ((insn & 0x00007000) >> 4)
3561 | ((insn & 0x04000000) >> 15);
3562 // Apply a sign to the added.
3563 addend *= sign;
3564
3565 int32_t x = (psymval->value(object, addend) | thumb_bit)
3566 - (address & 0xfffffffc);
3567 Reltype val = abs(x);
3568 // Mask out the value and a distinct part of the ADD/SUB opcode
3569 // (bits 7:5 of opword).
3570 insn = (insn & 0xfb0f8f00)
3571 | (val & 0xff)
3572 | ((val & 0x700) << 4)
3573 | ((val & 0x800) << 15);
3574 // Set the opcode according to whether the value to go in the
3575 // place is negative.
3576 if (x < 0)
3577 insn |= 0x00a00000;
3578
3579 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3580 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3581 return ((val > 0xfff) ?
3582 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3583 }
3584
3585 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3586 static inline typename This::Status
3587 thm_pc8(unsigned char* view,
3588 const Sized_relobj_file<32, big_endian>* object,
3589 const Symbol_value<32>* psymval,
3590 Arm_address address)
3591 {
3592 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3593 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3594 Valtype* wv = reinterpret_cast<Valtype*>(view);
3595 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3596 Reltype addend = ((insn & 0x00ff) << 2);
3597 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3598 Reltype val = abs(x);
3599 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3600
3601 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3602 return ((val > 0x03fc)
3603 ? This::STATUS_OVERFLOW
3604 : This::STATUS_OKAY);
3605 }
3606
3607 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3608 static inline typename This::Status
3609 thm_pc12(unsigned char* view,
3610 const Sized_relobj_file<32, big_endian>* object,
3611 const Symbol_value<32>* psymval,
3612 Arm_address address)
3613 {
3614 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3615 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3616 Valtype* wv = reinterpret_cast<Valtype*>(view);
3617 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3618 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3619 // Determine a sign for the addend (positive if the U bit is 1).
3620 const int sign = (insn & 0x00800000) ? 1 : -1;
3621 int32_t addend = (insn & 0xfff);
3622 // Apply a sign to the added.
3623 addend *= sign;
3624
3625 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3626 Reltype val = abs(x);
3627 // Mask out and apply the value and the U bit.
3628 insn = (insn & 0xff7ff000) | (val & 0xfff);
3629 // Set the U bit according to whether the value to go in the
3630 // place is positive.
3631 if (x >= 0)
3632 insn |= 0x00800000;
3633
3634 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3635 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3636 return ((val > 0xfff) ?
3637 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3638 }
3639
3640 // R_ARM_V4BX
3641 static inline typename This::Status
3642 v4bx(const Relocate_info<32, big_endian>* relinfo,
3643 unsigned char* view,
3644 const Arm_relobj<big_endian>* object,
3645 const Arm_address address,
3646 const bool is_interworking)
3647 {
3648
3649 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3650 Valtype* wv = reinterpret_cast<Valtype*>(view);
3651 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3652
3653 // Ensure that we have a BX instruction.
3654 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3655 const uint32_t reg = (val & 0xf);
3656 if (is_interworking && reg != 0xf)
3657 {
3658 Stub_table<big_endian>* stub_table =
3659 object->stub_table(relinfo->data_shndx);
3660 gold_assert(stub_table != NULL);
3661
3662 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3663 gold_assert(stub != NULL);
3664
3665 int32_t veneer_address =
3666 stub_table->address() + stub->offset() - 8 - address;
3667 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3668 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3669 // Replace with a branch to veneer (B <addr>)
3670 val = (val & 0xf0000000) | 0x0a000000
3671 | ((veneer_address >> 2) & 0x00ffffff);
3672 }
3673 else
3674 {
3675 // Preserve Rm (lowest four bits) and the condition code
3676 // (highest four bits). Other bits encode MOV PC,Rm.
3677 val = (val & 0xf000000f) | 0x01a0f000;
3678 }
3679 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3680 return This::STATUS_OKAY;
3681 }
3682
3683 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3684 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3685 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3686 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3687 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3688 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3689 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3690 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3691 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3692 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3693 static inline typename This::Status
3694 arm_grp_alu(unsigned char* view,
3695 const Sized_relobj_file<32, big_endian>* object,
3696 const Symbol_value<32>* psymval,
3697 const int group,
3698 Arm_address address,
3699 Arm_address thumb_bit,
3700 bool check_overflow)
3701 {
3702 gold_assert(group >= 0 && group < 3);
3703 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3704 Valtype* wv = reinterpret_cast<Valtype*>(view);
3705 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3706
3707 // ALU group relocations are allowed only for the ADD/SUB instructions.
3708 // (0x00800000 - ADD, 0x00400000 - SUB)
3709 const Valtype opcode = insn & 0x01e00000;
3710 if (opcode != 0x00800000 && opcode != 0x00400000)
3711 return This::STATUS_BAD_RELOC;
3712
3713 // Determine a sign for the addend.
3714 const int sign = (opcode == 0x00800000) ? 1 : -1;
3715 // shifter = rotate_imm * 2
3716 const uint32_t shifter = (insn & 0xf00) >> 7;
3717 // Initial addend value.
3718 int32_t addend = insn & 0xff;
3719 // Rotate addend right by shifter.
3720 addend = (addend >> shifter) | (addend << (32 - shifter));
3721 // Apply a sign to the added.
3722 addend *= sign;
3723
3724 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3725 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3726 // Check for overflow if required
3727 if (check_overflow
3728 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3729 return This::STATUS_OVERFLOW;
3730
3731 // Mask out the value and the ADD/SUB part of the opcode; take care
3732 // not to destroy the S bit.
3733 insn &= 0xff1ff000;
3734 // Set the opcode according to whether the value to go in the
3735 // place is negative.
3736 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3737 // Encode the offset (encoded Gn).
3738 insn |= gn;
3739
3740 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3741 return This::STATUS_OKAY;
3742 }
3743
3744 // R_ARM_LDR_PC_G0: S + A - P
3745 // R_ARM_LDR_PC_G1: S + A - P
3746 // R_ARM_LDR_PC_G2: S + A - P
3747 // R_ARM_LDR_SB_G0: S + A - B(S)
3748 // R_ARM_LDR_SB_G1: S + A - B(S)
3749 // R_ARM_LDR_SB_G2: S + A - B(S)
3750 static inline typename This::Status
3751 arm_grp_ldr(unsigned char* view,
3752 const Sized_relobj_file<32, big_endian>* object,
3753 const Symbol_value<32>* psymval,
3754 const int group,
3755 Arm_address address)
3756 {
3757 gold_assert(group >= 0 && group < 3);
3758 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3759 Valtype* wv = reinterpret_cast<Valtype*>(view);
3760 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3761
3762 const int sign = (insn & 0x00800000) ? 1 : -1;
3763 int32_t addend = (insn & 0xfff) * sign;
3764 int32_t x = (psymval->value(object, addend) - address);
3765 // Calculate the relevant G(n-1) value to obtain this stage residual.
3766 Valtype residual =
3767 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3768 if (residual >= 0x1000)
3769 return This::STATUS_OVERFLOW;
3770
3771 // Mask out the value and U bit.
3772 insn &= 0xff7ff000;
3773 // Set the U bit for non-negative values.
3774 if (x >= 0)
3775 insn |= 0x00800000;
3776 insn |= residual;
3777
3778 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3779 return This::STATUS_OKAY;
3780 }
3781
3782 // R_ARM_LDRS_PC_G0: S + A - P
3783 // R_ARM_LDRS_PC_G1: S + A - P
3784 // R_ARM_LDRS_PC_G2: S + A - P
3785 // R_ARM_LDRS_SB_G0: S + A - B(S)
3786 // R_ARM_LDRS_SB_G1: S + A - B(S)
3787 // R_ARM_LDRS_SB_G2: S + A - B(S)
3788 static inline typename This::Status
3789 arm_grp_ldrs(unsigned char* view,
3790 const Sized_relobj_file<32, big_endian>* object,
3791 const Symbol_value<32>* psymval,
3792 const int group,
3793 Arm_address address)
3794 {
3795 gold_assert(group >= 0 && group < 3);
3796 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3797 Valtype* wv = reinterpret_cast<Valtype*>(view);
3798 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3799
3800 const int sign = (insn & 0x00800000) ? 1 : -1;
3801 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3802 int32_t x = (psymval->value(object, addend) - address);
3803 // Calculate the relevant G(n-1) value to obtain this stage residual.
3804 Valtype residual =
3805 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3806 if (residual >= 0x100)
3807 return This::STATUS_OVERFLOW;
3808
3809 // Mask out the value and U bit.
3810 insn &= 0xff7ff0f0;
3811 // Set the U bit for non-negative values.
3812 if (x >= 0)
3813 insn |= 0x00800000;
3814 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3815
3816 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3817 return This::STATUS_OKAY;
3818 }
3819
3820 // R_ARM_LDC_PC_G0: S + A - P
3821 // R_ARM_LDC_PC_G1: S + A - P
3822 // R_ARM_LDC_PC_G2: S + A - P
3823 // R_ARM_LDC_SB_G0: S + A - B(S)
3824 // R_ARM_LDC_SB_G1: S + A - B(S)
3825 // R_ARM_LDC_SB_G2: S + A - B(S)
3826 static inline typename This::Status
3827 arm_grp_ldc(unsigned char* view,
3828 const Sized_relobj_file<32, big_endian>* object,
3829 const Symbol_value<32>* psymval,
3830 const int group,
3831 Arm_address address)
3832 {
3833 gold_assert(group >= 0 && group < 3);
3834 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3835 Valtype* wv = reinterpret_cast<Valtype*>(view);
3836 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3837
3838 const int sign = (insn & 0x00800000) ? 1 : -1;
3839 int32_t addend = ((insn & 0xff) << 2) * sign;
3840 int32_t x = (psymval->value(object, addend) - address);
3841 // Calculate the relevant G(n-1) value to obtain this stage residual.
3842 Valtype residual =
3843 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3844 if ((residual & 0x3) != 0 || residual >= 0x400)
3845 return This::STATUS_OVERFLOW;
3846
3847 // Mask out the value and U bit.
3848 insn &= 0xff7fff00;
3849 // Set the U bit for non-negative values.
3850 if (x >= 0)
3851 insn |= 0x00800000;
3852 insn |= (residual >> 2);
3853
3854 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3855 return This::STATUS_OKAY;
3856 }
3857 };
3858
3859 // Relocate ARM long branches. This handles relocation types
3860 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3861 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3862 // undefined and we do not use PLT in this relocation. In such a case,
3863 // the branch is converted into an NOP.
3864
3865 template<bool big_endian>
3866 typename Arm_relocate_functions<big_endian>::Status
3867 Arm_relocate_functions<big_endian>::arm_branch_common(
3868 unsigned int r_type,
3869 const Relocate_info<32, big_endian>* relinfo,
3870 unsigned char* view,
3871 const Sized_symbol<32>* gsym,
3872 const Arm_relobj<big_endian>* object,
3873 unsigned int r_sym,
3874 const Symbol_value<32>* psymval,
3875 Arm_address address,
3876 Arm_address thumb_bit,
3877 bool is_weakly_undefined_without_plt)
3878 {
3879 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3880 Valtype* wv = reinterpret_cast<Valtype*>(view);
3881 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3882
3883 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3884 && ((val & 0x0f000000UL) == 0x0a000000UL);
3885 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3886 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3887 && ((val & 0x0f000000UL) == 0x0b000000UL);
3888 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3889 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3890
3891 // Check that the instruction is valid.
3892 if (r_type == elfcpp::R_ARM_CALL)
3893 {
3894 if (!insn_is_uncond_bl && !insn_is_blx)
3895 return This::STATUS_BAD_RELOC;
3896 }
3897 else if (r_type == elfcpp::R_ARM_JUMP24)
3898 {
3899 if (!insn_is_b && !insn_is_cond_bl)
3900 return This::STATUS_BAD_RELOC;
3901 }
3902 else if (r_type == elfcpp::R_ARM_PLT32)
3903 {
3904 if (!insn_is_any_branch)
3905 return This::STATUS_BAD_RELOC;
3906 }
3907 else if (r_type == elfcpp::R_ARM_XPC25)
3908 {
3909 // FIXME: AAELF document IH0044C does not say much about it other
3910 // than it being obsolete.
3911 if (!insn_is_any_branch)
3912 return This::STATUS_BAD_RELOC;
3913 }
3914 else
3915 gold_unreachable();
3916
3917 // A branch to an undefined weak symbol is turned into a jump to
3918 // the next instruction unless a PLT entry will be created.
3919 // Do the same for local undefined symbols.
3920 // The jump to the next instruction is optimized as a NOP depending
3921 // on the architecture.
3922 const Target_arm<big_endian>* arm_target =
3923 Target_arm<big_endian>::default_target();
3924 if (is_weakly_undefined_without_plt)
3925 {
3926 gold_assert(!parameters->options().relocatable());
3927 Valtype cond = val & 0xf0000000U;
3928 if (arm_target->may_use_arm_nop())
3929 val = cond | 0x0320f000;
3930 else
3931 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3932 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3933 return This::STATUS_OKAY;
3934 }
3935
3936 Valtype addend = Bits<26>::sign_extend32(val << 2);
3937 Valtype branch_target = psymval->value(object, addend);
3938 int32_t branch_offset = branch_target - address;
3939
3940 // We need a stub if the branch offset is too large or if we need
3941 // to switch mode.
3942 bool may_use_blx = arm_target->may_use_v5t_interworking();
3943 Reloc_stub* stub = NULL;
3944
3945 if (!parameters->options().relocatable()
3946 && (Bits<26>::has_overflow32(branch_offset)
3947 || ((thumb_bit != 0)
3948 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3949 {
3950 Valtype unadjusted_branch_target = psymval->value(object, 0);
3951
3952 Stub_type stub_type =
3953 Reloc_stub::stub_type_for_reloc(r_type, address,
3954 unadjusted_branch_target,
3955 (thumb_bit != 0));
3956 if (stub_type != arm_stub_none)
3957 {
3958 Stub_table<big_endian>* stub_table =
3959 object->stub_table(relinfo->data_shndx);
3960 gold_assert(stub_table != NULL);
3961
3962 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3963 stub = stub_table->find_reloc_stub(stub_key);
3964 gold_assert(stub != NULL);
3965 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3966 branch_target = stub_table->address() + stub->offset() + addend;
3967 branch_offset = branch_target - address;
3968 gold_assert(!Bits<26>::has_overflow32(branch_offset));
3969 }
3970 }
3971
3972 // At this point, if we still need to switch mode, the instruction
3973 // must either be a BLX or a BL that can be converted to a BLX.
3974 if (thumb_bit != 0)
3975 {
3976 // Turn BL to BLX.
3977 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3978 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3979 }
3980
3981 val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3982 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3983 return (Bits<26>::has_overflow32(branch_offset)
3984 ? This::STATUS_OVERFLOW
3985 : This::STATUS_OKAY);
3986 }
3987
3988 // Relocate THUMB long branches. This handles relocation types
3989 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3990 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3991 // undefined and we do not use PLT in this relocation. In such a case,
3992 // the branch is converted into an NOP.
3993
3994 template<bool big_endian>
3995 typename Arm_relocate_functions<big_endian>::Status
3996 Arm_relocate_functions<big_endian>::thumb_branch_common(
3997 unsigned int r_type,
3998 const Relocate_info<32, big_endian>* relinfo,
3999 unsigned char* view,
4000 const Sized_symbol<32>* gsym,
4001 const Arm_relobj<big_endian>* object,
4002 unsigned int r_sym,
4003 const Symbol_value<32>* psymval,
4004 Arm_address address,
4005 Arm_address thumb_bit,
4006 bool is_weakly_undefined_without_plt)
4007 {
4008 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4009 Valtype* wv = reinterpret_cast<Valtype*>(view);
4010 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4011 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4012
4013 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4014 // into account.
4015 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4016 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4017
4018 // Check that the instruction is valid.
4019 if (r_type == elfcpp::R_ARM_THM_CALL)
4020 {
4021 if (!is_bl_insn && !is_blx_insn)
4022 return This::STATUS_BAD_RELOC;
4023 }
4024 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4025 {
4026 // This cannot be a BLX.
4027 if (!is_bl_insn)
4028 return This::STATUS_BAD_RELOC;
4029 }
4030 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4031 {
4032 // Check for Thumb to Thumb call.
4033 if (!is_blx_insn)
4034 return This::STATUS_BAD_RELOC;
4035 if (thumb_bit != 0)
4036 {
4037 gold_warning(_("%s: Thumb BLX instruction targets "
4038 "thumb function '%s'."),
4039 object->name().c_str(),
4040 (gsym ? gsym->name() : "(local)"));
4041 // Convert BLX to BL.
4042 lower_insn |= 0x1000U;
4043 }
4044 }
4045 else
4046 gold_unreachable();
4047
4048 // A branch to an undefined weak symbol is turned into a jump to
4049 // the next instruction unless a PLT entry will be created.
4050 // The jump to the next instruction is optimized as a NOP.W for
4051 // Thumb-2 enabled architectures.
4052 const Target_arm<big_endian>* arm_target =
4053 Target_arm<big_endian>::default_target();
4054 if (is_weakly_undefined_without_plt)
4055 {
4056 gold_assert(!parameters->options().relocatable());
4057 if (arm_target->may_use_thumb2_nop())
4058 {
4059 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4060 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4061 }
4062 else
4063 {
4064 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4065 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4066 }
4067 return This::STATUS_OKAY;
4068 }
4069
4070 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4071 Arm_address branch_target = psymval->value(object, addend);
4072
4073 // For BLX, bit 1 of target address comes from bit 1 of base address.
4074 bool may_use_blx = arm_target->may_use_v5t_interworking();
4075 if (thumb_bit == 0 && may_use_blx)
4076 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4077
4078 int32_t branch_offset = branch_target - address;
4079
4080 // We need a stub if the branch offset is too large or if we need
4081 // to switch mode.
4082 bool thumb2 = arm_target->using_thumb2();
4083 if (!parameters->options().relocatable()
4084 && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4085 || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4086 || ((thumb_bit == 0)
4087 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4088 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4089 {
4090 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4091
4092 Stub_type stub_type =
4093 Reloc_stub::stub_type_for_reloc(r_type, address,
4094 unadjusted_branch_target,
4095 (thumb_bit != 0));
4096
4097 if (stub_type != arm_stub_none)
4098 {
4099 Stub_table<big_endian>* stub_table =
4100 object->stub_table(relinfo->data_shndx);
4101 gold_assert(stub_table != NULL);
4102
4103 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4104 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4105 gold_assert(stub != NULL);
4106 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4107 branch_target = stub_table->address() + stub->offset() + addend;
4108 if (thumb_bit == 0 && may_use_blx)
4109 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4110 branch_offset = branch_target - address;
4111 }
4112 }
4113
4114 // At this point, if we still need to switch mode, the instruction
4115 // must either be a BLX or a BL that can be converted to a BLX.
4116 if (thumb_bit == 0)
4117 {
4118 gold_assert(may_use_blx
4119 && (r_type == elfcpp::R_ARM_THM_CALL
4120 || r_type == elfcpp::R_ARM_THM_XPC22));
4121 // Make sure this is a BLX.
4122 lower_insn &= ~0x1000U;
4123 }
4124 else
4125 {
4126 // Make sure this is a BL.
4127 lower_insn |= 0x1000U;
4128 }
4129
4130 // For a BLX instruction, make sure that the relocation is rounded up
4131 // to a word boundary. This follows the semantics of the instruction
4132 // which specifies that bit 1 of the target address will come from bit
4133 // 1 of the base address.
4134 if ((lower_insn & 0x5000U) == 0x4000U)
4135 gold_assert((branch_offset & 3) == 0);
4136
4137 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4138 // We use the Thumb-2 encoding, which is safe even if dealing with
4139 // a Thumb-1 instruction by virtue of our overflow check above. */
4140 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4141 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4142
4143 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4144 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4145
4146 gold_assert(!Bits<25>::has_overflow32(branch_offset));
4147
4148 return ((thumb2
4149 ? Bits<25>::has_overflow32(branch_offset)
4150 : Bits<23>::has_overflow32(branch_offset))
4151 ? This::STATUS_OVERFLOW
4152 : This::STATUS_OKAY);
4153 }
4154
4155 // Relocate THUMB-2 long conditional branches.
4156 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4157 // undefined and we do not use PLT in this relocation. In such a case,
4158 // the branch is converted into an NOP.
4159
4160 template<bool big_endian>
4161 typename Arm_relocate_functions<big_endian>::Status
4162 Arm_relocate_functions<big_endian>::thm_jump19(
4163 unsigned char* view,
4164 const Arm_relobj<big_endian>* object,
4165 const Symbol_value<32>* psymval,
4166 Arm_address address,
4167 Arm_address thumb_bit)
4168 {
4169 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4170 Valtype* wv = reinterpret_cast<Valtype*>(view);
4171 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4172 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4173 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4174
4175 Arm_address branch_target = psymval->value(object, addend);
4176 int32_t branch_offset = branch_target - address;
4177
4178 // ??? Should handle interworking? GCC might someday try to
4179 // use this for tail calls.
4180 // FIXME: We do support thumb entry to PLT yet.
4181 if (thumb_bit == 0)
4182 {
4183 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4184 return This::STATUS_BAD_RELOC;
4185 }
4186
4187 // Put RELOCATION back into the insn.
4188 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4189 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4190
4191 // Put the relocated value back in the object file:
4192 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4193 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4194
4195 return (Bits<21>::has_overflow32(branch_offset)
4196 ? This::STATUS_OVERFLOW
4197 : This::STATUS_OKAY);
4198 }
4199
4200 // Get the GOT section, creating it if necessary.
4201
4202 template<bool big_endian>
4203 Arm_output_data_got<big_endian>*
4204 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4205 {
4206 if (this->got_ == NULL)
4207 {
4208 gold_assert(symtab != NULL && layout != NULL);
4209
4210 // When using -z now, we can treat .got as a relro section.
4211 // Without -z now, it is modified after program startup by lazy
4212 // PLT relocations.
4213 bool is_got_relro = parameters->options().now();
4214 Output_section_order got_order = (is_got_relro
4215 ? ORDER_RELRO_LAST
4216 : ORDER_DATA);
4217
4218 // Unlike some targets (.e.g x86), ARM does not use separate .got and
4219 // .got.plt sections in output. The output .got section contains both
4220 // PLT and non-PLT GOT entries.
4221 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4222
4223 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4224 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4225 this->got_, got_order, is_got_relro);
4226
4227 // The old GNU linker creates a .got.plt section. We just
4228 // create another set of data in the .got section. Note that we
4229 // always create a PLT if we create a GOT, although the PLT
4230 // might be empty.
4231 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4232 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4233 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4234 this->got_plt_, got_order, is_got_relro);
4235
4236 // The first three entries are reserved.
4237 this->got_plt_->set_current_data_size(3 * 4);
4238
4239 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4240 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4241 Symbol_table::PREDEFINED,
4242 this->got_plt_,
4243 0, 0, elfcpp::STT_OBJECT,
4244 elfcpp::STB_LOCAL,
4245 elfcpp::STV_HIDDEN, 0,
4246 false, false);
4247 }
4248 return this->got_;
4249 }
4250
4251 // Get the dynamic reloc section, creating it if necessary.
4252
4253 template<bool big_endian>
4254 typename Target_arm<big_endian>::Reloc_section*
4255 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4256 {
4257 if (this->rel_dyn_ == NULL)
4258 {
4259 gold_assert(layout != NULL);
4260 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4261 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4262 elfcpp::SHF_ALLOC, this->rel_dyn_,
4263 ORDER_DYNAMIC_RELOCS, false);
4264 }
4265 return this->rel_dyn_;
4266 }
4267
4268 // Insn_template methods.
4269
4270 // Return byte size of an instruction template.
4271
4272 size_t
4273 Insn_template::size() const
4274 {
4275 switch (this->type())
4276 {
4277 case THUMB16_TYPE:
4278 case THUMB16_SPECIAL_TYPE:
4279 return 2;
4280 case ARM_TYPE:
4281 case THUMB32_TYPE:
4282 case DATA_TYPE:
4283 return 4;
4284 default:
4285 gold_unreachable();
4286 }
4287 }
4288
4289 // Return alignment of an instruction template.
4290
4291 unsigned
4292 Insn_template::alignment() const
4293 {
4294 switch (this->type())
4295 {
4296 case THUMB16_TYPE:
4297 case THUMB16_SPECIAL_TYPE:
4298 case THUMB32_TYPE:
4299 return 2;
4300 case ARM_TYPE:
4301 case DATA_TYPE:
4302 return 4;
4303 default:
4304 gold_unreachable();
4305 }
4306 }
4307
4308 // Stub_template methods.
4309
4310 Stub_template::Stub_template(
4311 Stub_type type, const Insn_template* insns,
4312 size_t insn_count)
4313 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4314 entry_in_thumb_mode_(false), relocs_()
4315 {
4316 off_t offset = 0;
4317
4318 // Compute byte size and alignment of stub template.
4319 for (size_t i = 0; i < insn_count; i++)
4320 {
4321 unsigned insn_alignment = insns[i].alignment();
4322 size_t insn_size = insns[i].size();
4323 gold_assert((offset & (insn_alignment - 1)) == 0);
4324 this->alignment_ = std::max(this->alignment_, insn_alignment);
4325 switch (insns[i].type())
4326 {
4327 case Insn_template::THUMB16_TYPE:
4328 case Insn_template::THUMB16_SPECIAL_TYPE:
4329 if (i == 0)
4330 this->entry_in_thumb_mode_ = true;
4331 break;
4332
4333 case Insn_template::THUMB32_TYPE:
4334 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4335 this->relocs_.push_back(Reloc(i, offset));
4336 if (i == 0)
4337 this->entry_in_thumb_mode_ = true;
4338 break;
4339
4340 case Insn_template::ARM_TYPE:
4341 // Handle cases where the target is encoded within the
4342 // instruction.
4343 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4344 this->relocs_.push_back(Reloc(i, offset));
4345 break;
4346
4347 case Insn_template::DATA_TYPE:
4348 // Entry point cannot be data.
4349 gold_assert(i != 0);
4350 this->relocs_.push_back(Reloc(i, offset));
4351 break;
4352
4353 default:
4354 gold_unreachable();
4355 }
4356 offset += insn_size;
4357 }
4358 this->size_ = offset;
4359 }
4360
4361 // Stub methods.
4362
4363 // Template to implement do_write for a specific target endianness.
4364
4365 template<bool big_endian>
4366 void inline
4367 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4368 {
4369 const Stub_template* stub_template = this->stub_template();
4370 const Insn_template* insns = stub_template->insns();
4371
4372 // FIXME: We do not handle BE8 encoding yet.
4373 unsigned char* pov = view;
4374 for (size_t i = 0; i < stub_template->insn_count(); i++)
4375 {
4376 switch (insns[i].type())
4377 {
4378 case Insn_template::THUMB16_TYPE:
4379 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4380 break;
4381 case Insn_template::THUMB16_SPECIAL_TYPE:
4382 elfcpp::Swap<16, big_endian>::writeval(
4383 pov,
4384 this->thumb16_special(i));
4385 break;
4386 case Insn_template::THUMB32_TYPE:
4387 {
4388 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4389 uint32_t lo = insns[i].data() & 0xffff;
4390 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4391 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4392 }
4393 break;
4394 case Insn_template::ARM_TYPE:
4395 case Insn_template::DATA_TYPE:
4396 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4397 break;
4398 default:
4399 gold_unreachable();
4400 }
4401 pov += insns[i].size();
4402 }
4403 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4404 }
4405
4406 // Reloc_stub::Key methods.
4407
4408 // Dump a Key as a string for debugging.
4409
4410 std::string
4411 Reloc_stub::Key::name() const
4412 {
4413 if (this->r_sym_ == invalid_index)
4414 {
4415 // Global symbol key name
4416 // <stub-type>:<symbol name>:<addend>.
4417 const std::string sym_name = this->u_.symbol->name();
4418 // We need to print two hex number and two colons. So just add 100 bytes
4419 // to the symbol name size.
4420 size_t len = sym_name.size() + 100;
4421 char* buffer = new char[len];
4422 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4423 sym_name.c_str(), this->addend_);
4424 gold_assert(c > 0 && c < static_cast<int>(len));
4425 delete[] buffer;
4426 return std::string(buffer);
4427 }
4428 else
4429 {
4430 // local symbol key name
4431 // <stub-type>:<object>:<r_sym>:<addend>.
4432 const size_t len = 200;
4433 char buffer[len];
4434 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4435 this->u_.relobj, this->r_sym_, this->addend_);
4436 gold_assert(c > 0 && c < static_cast<int>(len));
4437 return std::string(buffer);
4438 }
4439 }
4440
4441 // Reloc_stub methods.
4442
4443 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4444 // LOCATION to DESTINATION.
4445 // This code is based on the arm_type_of_stub function in
4446 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4447 // class simple.
4448
4449 Stub_type
4450 Reloc_stub::stub_type_for_reloc(
4451 unsigned int r_type,
4452 Arm_address location,
4453 Arm_address destination,
4454 bool target_is_thumb)
4455 {
4456 Stub_type stub_type = arm_stub_none;
4457
4458 // This is a bit ugly but we want to avoid using a templated class for
4459 // big and little endianities.
4460 bool may_use_blx;
4461 bool should_force_pic_veneer;
4462 bool thumb2;
4463 bool thumb_only;
4464 if (parameters->target().is_big_endian())
4465 {
4466 const Target_arm<true>* big_endian_target =
4467 Target_arm<true>::default_target();
4468 may_use_blx = big_endian_target->may_use_v5t_interworking();
4469 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4470 thumb2 = big_endian_target->using_thumb2();
4471 thumb_only = big_endian_target->using_thumb_only();
4472 }
4473 else
4474 {
4475 const Target_arm<false>* little_endian_target =
4476 Target_arm<false>::default_target();
4477 may_use_blx = little_endian_target->may_use_v5t_interworking();
4478 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4479 thumb2 = little_endian_target->using_thumb2();
4480 thumb_only = little_endian_target->using_thumb_only();
4481 }
4482
4483 int64_t branch_offset;
4484 bool output_is_position_independent =
4485 parameters->options().output_is_position_independent();
4486 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4487 {
4488 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4489 // base address (instruction address + 4).
4490 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4491 destination = Bits<32>::bit_select32(destination, location, 0x2);
4492 branch_offset = static_cast<int64_t>(destination) - location;
4493
4494 // Handle cases where:
4495 // - this call goes too far (different Thumb/Thumb2 max
4496 // distance)
4497 // - it's a Thumb->Arm call and blx is not available, or it's a
4498 // Thumb->Arm branch (not bl). A stub is needed in this case.
4499 if ((!thumb2
4500 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4501 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4502 || (thumb2
4503 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4504 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4505 || ((!target_is_thumb)
4506 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4507 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4508 {
4509 if (target_is_thumb)
4510 {
4511 // Thumb to thumb.
4512 if (!thumb_only)
4513 {
4514 stub_type = (output_is_position_independent
4515 || should_force_pic_veneer)
4516 // PIC stubs.
4517 ? ((may_use_blx
4518 && (r_type == elfcpp::R_ARM_THM_CALL))
4519 // V5T and above. Stub starts with ARM code, so
4520 // we must be able to switch mode before
4521 // reaching it, which is only possible for 'bl'
4522 // (ie R_ARM_THM_CALL relocation).
4523 ? arm_stub_long_branch_any_thumb_pic
4524 // On V4T, use Thumb code only.
4525 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4526
4527 // non-PIC stubs.
4528 : ((may_use_blx
4529 && (r_type == elfcpp::R_ARM_THM_CALL))
4530 ? arm_stub_long_branch_any_any // V5T and above.
4531 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4532 }
4533 else
4534 {
4535 stub_type = (output_is_position_independent
4536 || should_force_pic_veneer)
4537 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4538 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4539 }
4540 }
4541 else
4542 {
4543 // Thumb to arm.
4544
4545 // FIXME: We should check that the input section is from an
4546 // object that has interwork enabled.
4547
4548 stub_type = (output_is_position_independent
4549 || should_force_pic_veneer)
4550 // PIC stubs.
4551 ? ((may_use_blx
4552 && (r_type == elfcpp::R_ARM_THM_CALL))
4553 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4554 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4555
4556 // non-PIC stubs.
4557 : ((may_use_blx
4558 && (r_type == elfcpp::R_ARM_THM_CALL))
4559 ? arm_stub_long_branch_any_any // V5T and above.
4560 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4561
4562 // Handle v4t short branches.
4563 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4564 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4565 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4566 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4567 }
4568 }
4569 }
4570 else if (r_type == elfcpp::R_ARM_CALL
4571 || r_type == elfcpp::R_ARM_JUMP24
4572 || r_type == elfcpp::R_ARM_PLT32)
4573 {
4574 branch_offset = static_cast<int64_t>(destination) - location;
4575 if (target_is_thumb)
4576 {
4577 // Arm to thumb.
4578
4579 // FIXME: We should check that the input section is from an
4580 // object that has interwork enabled.
4581
4582 // We have an extra 2-bytes reach because of
4583 // the mode change (bit 24 (H) of BLX encoding).
4584 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4585 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4586 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4587 || (r_type == elfcpp::R_ARM_JUMP24)
4588 || (r_type == elfcpp::R_ARM_PLT32))
4589 {
4590 stub_type = (output_is_position_independent
4591 || should_force_pic_veneer)
4592 // PIC stubs.
4593 ? (may_use_blx
4594 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4595 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4596
4597 // non-PIC stubs.
4598 : (may_use_blx
4599 ? arm_stub_long_branch_any_any // V5T and above.
4600 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4601 }
4602 }
4603 else
4604 {
4605 // Arm to arm.
4606 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4607 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4608 {
4609 stub_type = (output_is_position_independent
4610 || should_force_pic_veneer)
4611 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4612 : arm_stub_long_branch_any_any; /// non-PIC.
4613 }
4614 }
4615 }
4616
4617 return stub_type;
4618 }
4619
4620 // Cortex_a8_stub methods.
4621
4622 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4623 // I is the position of the instruction template in the stub template.
4624
4625 uint16_t
4626 Cortex_a8_stub::do_thumb16_special(size_t i)
4627 {
4628 // The only use of this is to copy condition code from a conditional
4629 // branch being worked around to the corresponding conditional branch in
4630 // to the stub.
4631 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4632 && i == 0);
4633 uint16_t data = this->stub_template()->insns()[i].data();
4634 gold_assert((data & 0xff00U) == 0xd000U);
4635 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4636 return data;
4637 }
4638
4639 // Stub_factory methods.
4640
4641 Stub_factory::Stub_factory()
4642 {
4643 // The instruction template sequences are declared as static
4644 // objects and initialized first time the constructor runs.
4645
4646 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4647 // to reach the stub if necessary.
4648 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4649 {
4650 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4651 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4652 // dcd R_ARM_ABS32(X)
4653 };
4654
4655 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4656 // available.
4657 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4658 {
4659 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4660 Insn_template::arm_insn(0xe12fff1c), // bx ip
4661 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4662 // dcd R_ARM_ABS32(X)
4663 };
4664
4665 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4666 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4667 {
4668 Insn_template::thumb16_insn(0xb401), // push {r0}
4669 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4670 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4671 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4672 Insn_template::thumb16_insn(0x4760), // bx ip
4673 Insn_template::thumb16_insn(0xbf00), // nop
4674 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4675 // dcd R_ARM_ABS32(X)
4676 };
4677
4678 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4679 // allowed.
4680 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4681 {
4682 Insn_template::thumb16_insn(0x4778), // bx pc
4683 Insn_template::thumb16_insn(0x46c0), // nop
4684 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4685 Insn_template::arm_insn(0xe12fff1c), // bx ip
4686 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4687 // dcd R_ARM_ABS32(X)
4688 };
4689
4690 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4691 // available.
4692 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4693 {
4694 Insn_template::thumb16_insn(0x4778), // bx pc
4695 Insn_template::thumb16_insn(0x46c0), // nop
4696 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4697 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4698 // dcd R_ARM_ABS32(X)
4699 };
4700
4701 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4702 // one, when the destination is close enough.
4703 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4704 {
4705 Insn_template::thumb16_insn(0x4778), // bx pc
4706 Insn_template::thumb16_insn(0x46c0), // nop
4707 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4708 };
4709
4710 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4711 // blx to reach the stub if necessary.
4712 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4713 {
4714 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4715 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4716 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4717 // dcd R_ARM_REL32(X-4)
4718 };
4719
4720 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4721 // blx to reach the stub if necessary. We can not add into pc;
4722 // it is not guaranteed to mode switch (different in ARMv6 and
4723 // ARMv7).
4724 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4725 {
4726 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4727 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4728 Insn_template::arm_insn(0xe12fff1c), // bx ip
4729 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4730 // dcd R_ARM_REL32(X)
4731 };
4732
4733 // V4T ARM -> ARM long branch stub, PIC.
4734 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4735 {
4736 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4737 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4738 Insn_template::arm_insn(0xe12fff1c), // bx ip
4739 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4740 // dcd R_ARM_REL32(X)
4741 };
4742
4743 // V4T Thumb -> ARM long branch stub, PIC.
4744 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4745 {
4746 Insn_template::thumb16_insn(0x4778), // bx pc
4747 Insn_template::thumb16_insn(0x46c0), // nop
4748 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4749 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4750 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4751 // dcd R_ARM_REL32(X)
4752 };
4753
4754 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4755 // architectures.
4756 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4757 {
4758 Insn_template::thumb16_insn(0xb401), // push {r0}
4759 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4760 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4761 Insn_template::thumb16_insn(0x4484), // add ip, r0
4762 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4763 Insn_template::thumb16_insn(0x4760), // bx ip
4764 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4765 // dcd R_ARM_REL32(X)
4766 };
4767
4768 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4769 // allowed.
4770 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4771 {
4772 Insn_template::thumb16_insn(0x4778), // bx pc
4773 Insn_template::thumb16_insn(0x46c0), // nop
4774 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4775 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4776 Insn_template::arm_insn(0xe12fff1c), // bx ip
4777 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4778 // dcd R_ARM_REL32(X)
4779 };
4780
4781 // Cortex-A8 erratum-workaround stubs.
4782
4783 // Stub used for conditional branches (which may be beyond +/-1MB away,
4784 // so we can't use a conditional branch to reach this stub).
4785
4786 // original code:
4787 //
4788 // b<cond> X
4789 // after:
4790 //
4791 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4792 {
4793 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4794 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4795 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4796 // b.w X
4797 };
4798
4799 // Stub used for b.w and bl.w instructions.
4800
4801 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4802 {
4803 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4804 };
4805
4806 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4807 {
4808 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4809 };
4810
4811 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4812 // instruction (which switches to ARM mode) to point to this stub. Jump to
4813 // the real destination using an ARM-mode branch.
4814 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4815 {
4816 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4817 };
4818
4819 // Stub used to provide an interworking for R_ARM_V4BX relocation
4820 // (bx r[n] instruction).
4821 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4822 {
4823 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4824 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4825 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4826 };
4827
4828 // Fill in the stub template look-up table. Stub templates are constructed
4829 // per instance of Stub_factory for fast look-up without locking
4830 // in a thread-enabled environment.
4831
4832 this->stub_templates_[arm_stub_none] =
4833 new Stub_template(arm_stub_none, NULL, 0);
4834
4835 #define DEF_STUB(x) \
4836 do \
4837 { \
4838 size_t array_size \
4839 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4840 Stub_type type = arm_stub_##x; \
4841 this->stub_templates_[type] = \
4842 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4843 } \
4844 while (0);
4845
4846 DEF_STUBS
4847 #undef DEF_STUB
4848 }
4849
4850 // Stub_table methods.
4851
4852 // Remove all Cortex-A8 stub.
4853
4854 template<bool big_endian>
4855 void
4856 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4857 {
4858 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4859 p != this->cortex_a8_stubs_.end();
4860 ++p)
4861 delete p->second;
4862 this->cortex_a8_stubs_.clear();
4863 }
4864
4865 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4866
4867 template<bool big_endian>
4868 void
4869 Stub_table<big_endian>::relocate_stub(
4870 Stub* stub,
4871 const Relocate_info<32, big_endian>* relinfo,
4872 Target_arm<big_endian>* arm_target,
4873 Output_section* output_section,
4874 unsigned char* view,
4875 Arm_address address,
4876 section_size_type view_size)
4877 {
4878 const Stub_template* stub_template = stub->stub_template();
4879 if (stub_template->reloc_count() != 0)
4880 {
4881 // Adjust view to cover the stub only.
4882 section_size_type offset = stub->offset();
4883 section_size_type stub_size = stub_template->size();
4884 gold_assert(offset + stub_size <= view_size);
4885
4886 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4887 address + offset, stub_size);
4888 }
4889 }
4890
4891 // Relocate all stubs in this stub table.
4892
4893 template<bool big_endian>
4894 void
4895 Stub_table<big_endian>::relocate_stubs(
4896 const Relocate_info<32, big_endian>* relinfo,
4897 Target_arm<big_endian>* arm_target,
4898 Output_section* output_section,
4899 unsigned char* view,
4900 Arm_address address,
4901 section_size_type view_size)
4902 {
4903 // If we are passed a view bigger than the stub table's. we need to
4904 // adjust the view.
4905 gold_assert(address == this->address()
4906 && (view_size
4907 == static_cast<section_size_type>(this->data_size())));
4908
4909 // Relocate all relocation stubs.
4910 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4911 p != this->reloc_stubs_.end();
4912 ++p)
4913 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4914 address, view_size);
4915
4916 // Relocate all Cortex-A8 stubs.
4917 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4918 p != this->cortex_a8_stubs_.end();
4919 ++p)
4920 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4921 address, view_size);
4922
4923 // Relocate all ARM V4BX stubs.
4924 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4925 p != this->arm_v4bx_stubs_.end();
4926 ++p)
4927 {
4928 if (*p != NULL)
4929 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4930 address, view_size);
4931 }
4932 }
4933
4934 // Write out the stubs to file.
4935
4936 template<bool big_endian>
4937 void
4938 Stub_table<big_endian>::do_write(Output_file* of)
4939 {
4940 off_t offset = this->offset();
4941 const section_size_type oview_size =
4942 convert_to_section_size_type(this->data_size());
4943 unsigned char* const oview = of->get_output_view(offset, oview_size);
4944
4945 // Write relocation stubs.
4946 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4947 p != this->reloc_stubs_.end();
4948 ++p)
4949 {
4950 Reloc_stub* stub = p->second;
4951 Arm_address address = this->address() + stub->offset();
4952 gold_assert(address
4953 == align_address(address,
4954 stub->stub_template()->alignment()));
4955 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4956 big_endian);
4957 }
4958
4959 // Write Cortex-A8 stubs.
4960 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4961 p != this->cortex_a8_stubs_.end();
4962 ++p)
4963 {
4964 Cortex_a8_stub* stub = p->second;
4965 Arm_address address = this->address() + stub->offset();
4966 gold_assert(address
4967 == align_address(address,
4968 stub->stub_template()->alignment()));
4969 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4970 big_endian);
4971 }
4972
4973 // Write ARM V4BX relocation stubs.
4974 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4975 p != this->arm_v4bx_stubs_.end();
4976 ++p)
4977 {
4978 if (*p == NULL)
4979 continue;
4980
4981 Arm_address address = this->address() + (*p)->offset();
4982 gold_assert(address
4983 == align_address(address,
4984 (*p)->stub_template()->alignment()));
4985 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4986 big_endian);
4987 }
4988
4989 of->write_output_view(this->offset(), oview_size, oview);
4990 }
4991
4992 // Update the data size and address alignment of the stub table at the end
4993 // of a relaxation pass. Return true if either the data size or the
4994 // alignment changed in this relaxation pass.
4995
4996 template<bool big_endian>
4997 bool
4998 Stub_table<big_endian>::update_data_size_and_addralign()
4999 {
5000 // Go over all stubs in table to compute data size and address alignment.
5001 off_t size = this->reloc_stubs_size_;
5002 unsigned addralign = this->reloc_stubs_addralign_;
5003
5004 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5005 p != this->cortex_a8_stubs_.end();
5006 ++p)
5007 {
5008 const Stub_template* stub_template = p->second->stub_template();
5009 addralign = std::max(addralign, stub_template->alignment());
5010 size = (align_address(size, stub_template->alignment())
5011 + stub_template->size());
5012 }
5013
5014 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5015 p != this->arm_v4bx_stubs_.end();
5016 ++p)
5017 {
5018 if (*p == NULL)
5019 continue;
5020
5021 const Stub_template* stub_template = (*p)->stub_template();
5022 addralign = std::max(addralign, stub_template->alignment());
5023 size = (align_address(size, stub_template->alignment())
5024 + stub_template->size());
5025 }
5026
5027 // Check if either data size or alignment changed in this pass.
5028 // Update prev_data_size_ and prev_addralign_. These will be used
5029 // as the current data size and address alignment for the next pass.
5030 bool changed = size != this->prev_data_size_;
5031 this->prev_data_size_ = size;
5032
5033 if (addralign != this->prev_addralign_)
5034 changed = true;
5035 this->prev_addralign_ = addralign;
5036
5037 return changed;
5038 }
5039
5040 // Finalize the stubs. This sets the offsets of the stubs within the stub
5041 // table. It also marks all input sections needing Cortex-A8 workaround.
5042
5043 template<bool big_endian>
5044 void
5045 Stub_table<big_endian>::finalize_stubs()
5046 {
5047 off_t off = this->reloc_stubs_size_;
5048 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5049 p != this->cortex_a8_stubs_.end();
5050 ++p)
5051 {
5052 Cortex_a8_stub* stub = p->second;
5053 const Stub_template* stub_template = stub->stub_template();
5054 uint64_t stub_addralign = stub_template->alignment();
5055 off = align_address(off, stub_addralign);
5056 stub->set_offset(off);
5057 off += stub_template->size();
5058
5059 // Mark input section so that we can determine later if a code section
5060 // needs the Cortex-A8 workaround quickly.
5061 Arm_relobj<big_endian>* arm_relobj =
5062 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5063 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5064 }
5065
5066 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5067 p != this->arm_v4bx_stubs_.end();
5068 ++p)
5069 {
5070 if (*p == NULL)
5071 continue;
5072
5073 const Stub_template* stub_template = (*p)->stub_template();
5074 uint64_t stub_addralign = stub_template->alignment();
5075 off = align_address(off, stub_addralign);
5076 (*p)->set_offset(off);
5077 off += stub_template->size();
5078 }
5079
5080 gold_assert(off <= this->prev_data_size_);
5081 }
5082
5083 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5084 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5085 // of the address range seen by the linker.
5086
5087 template<bool big_endian>
5088 void
5089 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5090 Target_arm<big_endian>* arm_target,
5091 unsigned char* view,
5092 Arm_address view_address,
5093 section_size_type view_size)
5094 {
5095 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5096 for (Cortex_a8_stub_list::const_iterator p =
5097 this->cortex_a8_stubs_.lower_bound(view_address);
5098 ((p != this->cortex_a8_stubs_.end())
5099 && (p->first < (view_address + view_size)));
5100 ++p)
5101 {
5102 // We do not store the THUMB bit in the LSB of either the branch address
5103 // or the stub offset. There is no need to strip the LSB.
5104 Arm_address branch_address = p->first;
5105 const Cortex_a8_stub* stub = p->second;
5106 Arm_address stub_address = this->address() + stub->offset();
5107
5108 // Offset of the branch instruction relative to this view.
5109 section_size_type offset =
5110 convert_to_section_size_type(branch_address - view_address);
5111 gold_assert((offset + 4) <= view_size);
5112
5113 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5114 view + offset, branch_address);
5115 }
5116 }
5117
5118 // Arm_input_section methods.
5119
5120 // Initialize an Arm_input_section.
5121
5122 template<bool big_endian>
5123 void
5124 Arm_input_section<big_endian>::init()
5125 {
5126 Relobj* relobj = this->relobj();
5127 unsigned int shndx = this->shndx();
5128
5129 // We have to cache original size, alignment and contents to avoid locking
5130 // the original file.
5131 this->original_addralign_ =
5132 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5133
5134 // This is not efficient but we expect only a small number of relaxed
5135 // input sections for stubs.
5136 section_size_type section_size;
5137 const unsigned char* section_contents =
5138 relobj->section_contents(shndx, &section_size, false);
5139 this->original_size_ =
5140 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5141
5142 gold_assert(this->original_contents_ == NULL);
5143 this->original_contents_ = new unsigned char[section_size];
5144 memcpy(this->original_contents_, section_contents, section_size);
5145
5146 // We want to make this look like the original input section after
5147 // output sections are finalized.
5148 Output_section* os = relobj->output_section(shndx);
5149 off_t offset = relobj->output_section_offset(shndx);
5150 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5151 this->set_address(os->address() + offset);
5152 this->set_file_offset(os->offset() + offset);
5153
5154 this->set_current_data_size(this->original_size_);
5155 this->finalize_data_size();
5156 }
5157
5158 template<bool big_endian>
5159 void
5160 Arm_input_section<big_endian>::do_write(Output_file* of)
5161 {
5162 // We have to write out the original section content.
5163 gold_assert(this->original_contents_ != NULL);
5164 of->write(this->offset(), this->original_contents_,
5165 this->original_size_);
5166
5167 // If this owns a stub table and it is not empty, write it.
5168 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5169 this->stub_table_->write(of);
5170 }
5171
5172 // Finalize data size.
5173
5174 template<bool big_endian>
5175 void
5176 Arm_input_section<big_endian>::set_final_data_size()
5177 {
5178 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5179
5180 if (this->is_stub_table_owner())
5181 {
5182 this->stub_table_->finalize_data_size();
5183 off = align_address(off, this->stub_table_->addralign());
5184 off += this->stub_table_->data_size();
5185 }
5186 this->set_data_size(off);
5187 }
5188
5189 // Reset address and file offset.
5190
5191 template<bool big_endian>
5192 void
5193 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5194 {
5195 // Size of the original input section contents.
5196 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5197
5198 // If this is a stub table owner, account for the stub table size.
5199 if (this->is_stub_table_owner())
5200 {
5201 Stub_table<big_endian>* stub_table = this->stub_table_;
5202
5203 // Reset the stub table's address and file offset. The
5204 // current data size for child will be updated after that.
5205 stub_table_->reset_address_and_file_offset();
5206 off = align_address(off, stub_table_->addralign());
5207 off += stub_table->current_data_size();
5208 }
5209
5210 this->set_current_data_size(off);
5211 }
5212
5213 // Arm_exidx_cantunwind methods.
5214
5215 // Write this to Output file OF for a fixed endianness.
5216
5217 template<bool big_endian>
5218 void
5219 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5220 {
5221 off_t offset = this->offset();
5222 const section_size_type oview_size = 8;
5223 unsigned char* const oview = of->get_output_view(offset, oview_size);
5224
5225 Output_section* os = this->relobj_->output_section(this->shndx_);
5226 gold_assert(os != NULL);
5227
5228 Arm_relobj<big_endian>* arm_relobj =
5229 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5230 Arm_address output_offset =
5231 arm_relobj->get_output_section_offset(this->shndx_);
5232 Arm_address section_start;
5233 section_size_type section_size;
5234
5235 // Find out the end of the text section referred by this.
5236 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5237 {
5238 section_start = os->address() + output_offset;
5239 const Arm_exidx_input_section* exidx_input_section =
5240 arm_relobj->exidx_input_section_by_link(this->shndx_);
5241 gold_assert(exidx_input_section != NULL);
5242 section_size =
5243 convert_to_section_size_type(exidx_input_section->text_size());
5244 }
5245 else
5246 {
5247 // Currently this only happens for a relaxed section.
5248 const Output_relaxed_input_section* poris =
5249 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5250 gold_assert(poris != NULL);
5251 section_start = poris->address();
5252 section_size = convert_to_section_size_type(poris->data_size());
5253 }
5254
5255 // We always append this to the end of an EXIDX section.
5256 Arm_address output_address = section_start + section_size;
5257
5258 // Write out the entry. The first word either points to the beginning
5259 // or after the end of a text section. The second word is the special
5260 // EXIDX_CANTUNWIND value.
5261 uint32_t prel31_offset = output_address - this->address();
5262 if (Bits<31>::has_overflow32(offset))
5263 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5264 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5265 prel31_offset & 0x7fffffffU);
5266 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5267 elfcpp::EXIDX_CANTUNWIND);
5268
5269 of->write_output_view(this->offset(), oview_size, oview);
5270 }
5271
5272 // Arm_exidx_merged_section methods.
5273
5274 // Constructor for Arm_exidx_merged_section.
5275 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5276 // SECTION_OFFSET_MAP points to a section offset map describing how
5277 // parts of the input section are mapped to output. DELETED_BYTES is
5278 // the number of bytes deleted from the EXIDX input section.
5279
5280 Arm_exidx_merged_section::Arm_exidx_merged_section(
5281 const Arm_exidx_input_section& exidx_input_section,
5282 const Arm_exidx_section_offset_map& section_offset_map,
5283 uint32_t deleted_bytes)
5284 : Output_relaxed_input_section(exidx_input_section.relobj(),
5285 exidx_input_section.shndx(),
5286 exidx_input_section.addralign()),
5287 exidx_input_section_(exidx_input_section),
5288 section_offset_map_(section_offset_map)
5289 {
5290 // If we retain or discard the whole EXIDX input section, we would
5291 // not be here.
5292 gold_assert(deleted_bytes != 0
5293 && deleted_bytes != this->exidx_input_section_.size());
5294
5295 // Fix size here so that we do not need to implement set_final_data_size.
5296 uint32_t size = exidx_input_section.size() - deleted_bytes;
5297 this->set_data_size(size);
5298 this->fix_data_size();
5299
5300 // Allocate buffer for section contents and build contents.
5301 this->section_contents_ = new unsigned char[size];
5302 }
5303
5304 // Build the contents of a merged EXIDX output section.
5305
5306 void
5307 Arm_exidx_merged_section::build_contents(
5308 const unsigned char* original_contents,
5309 section_size_type original_size)
5310 {
5311 // Go over spans of input offsets and write only those that are not
5312 // discarded.
5313 section_offset_type in_start = 0;
5314 section_offset_type out_start = 0;
5315 section_offset_type in_max =
5316 convert_types<section_offset_type>(original_size);
5317 section_offset_type out_max =
5318 convert_types<section_offset_type>(this->data_size());
5319 for (Arm_exidx_section_offset_map::const_iterator p =
5320 this->section_offset_map_.begin();
5321 p != this->section_offset_map_.end();
5322 ++p)
5323 {
5324 section_offset_type in_end = p->first;
5325 gold_assert(in_end >= in_start);
5326 section_offset_type out_end = p->second;
5327 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5328 if (out_end != -1)
5329 {
5330 size_t out_chunk_size =
5331 convert_types<size_t>(out_end - out_start + 1);
5332
5333 gold_assert(out_chunk_size == in_chunk_size
5334 && in_end < in_max && out_end < out_max);
5335
5336 memcpy(this->section_contents_ + out_start,
5337 original_contents + in_start,
5338 out_chunk_size);
5339 out_start += out_chunk_size;
5340 }
5341 in_start += in_chunk_size;
5342 }
5343 }
5344
5345 // Given an input OBJECT, an input section index SHNDX within that
5346 // object, and an OFFSET relative to the start of that input
5347 // section, return whether or not the corresponding offset within
5348 // the output section is known. If this function returns true, it
5349 // sets *POUTPUT to the output offset. The value -1 indicates that
5350 // this input offset is being discarded.
5351
5352 bool
5353 Arm_exidx_merged_section::do_output_offset(
5354 const Relobj* relobj,
5355 unsigned int shndx,
5356 section_offset_type offset,
5357 section_offset_type* poutput) const
5358 {
5359 // We only handle offsets for the original EXIDX input section.
5360 if (relobj != this->exidx_input_section_.relobj()
5361 || shndx != this->exidx_input_section_.shndx())
5362 return false;
5363
5364 section_offset_type section_size =
5365 convert_types<section_offset_type>(this->exidx_input_section_.size());
5366 if (offset < 0 || offset >= section_size)
5367 // Input offset is out of valid range.
5368 *poutput = -1;
5369 else
5370 {
5371 // We need to look up the section offset map to determine the output
5372 // offset. Find the reference point in map that is first offset
5373 // bigger than or equal to this offset.
5374 Arm_exidx_section_offset_map::const_iterator p =
5375 this->section_offset_map_.lower_bound(offset);
5376
5377 // The section offset maps are build such that this should not happen if
5378 // input offset is in the valid range.
5379 gold_assert(p != this->section_offset_map_.end());
5380
5381 // We need to check if this is dropped.
5382 section_offset_type ref = p->first;
5383 section_offset_type mapped_ref = p->second;
5384
5385 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5386 // Offset is present in output.
5387 *poutput = mapped_ref + (offset - ref);
5388 else
5389 // Offset is discarded owing to EXIDX entry merging.
5390 *poutput = -1;
5391 }
5392
5393 return true;
5394 }
5395
5396 // Write this to output file OF.
5397
5398 void
5399 Arm_exidx_merged_section::do_write(Output_file* of)
5400 {
5401 off_t offset = this->offset();
5402 const section_size_type oview_size = this->data_size();
5403 unsigned char* const oview = of->get_output_view(offset, oview_size);
5404
5405 Output_section* os = this->relobj()->output_section(this->shndx());
5406 gold_assert(os != NULL);
5407
5408 memcpy(oview, this->section_contents_, oview_size);
5409 of->write_output_view(this->offset(), oview_size, oview);
5410 }
5411
5412 // Arm_exidx_fixup methods.
5413
5414 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5415 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5416 // points to the end of the last seen EXIDX section.
5417
5418 void
5419 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5420 {
5421 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5422 && this->last_input_section_ != NULL)
5423 {
5424 Relobj* relobj = this->last_input_section_->relobj();
5425 unsigned int text_shndx = this->last_input_section_->link();
5426 Arm_exidx_cantunwind* cantunwind =
5427 new Arm_exidx_cantunwind(relobj, text_shndx);
5428 this->exidx_output_section_->add_output_section_data(cantunwind);
5429 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5430 }
5431 }
5432
5433 // Process an EXIDX section entry in input. Return whether this entry
5434 // can be deleted in the output. SECOND_WORD in the second word of the
5435 // EXIDX entry.
5436
5437 bool
5438 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5439 {
5440 bool delete_entry;
5441 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5442 {
5443 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5444 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5445 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5446 }
5447 else if ((second_word & 0x80000000) != 0)
5448 {
5449 // Inlined unwinding data. Merge if equal to previous.
5450 delete_entry = (merge_exidx_entries_
5451 && this->last_unwind_type_ == UT_INLINED_ENTRY
5452 && this->last_inlined_entry_ == second_word);
5453 this->last_unwind_type_ = UT_INLINED_ENTRY;
5454 this->last_inlined_entry_ = second_word;
5455 }
5456 else
5457 {
5458 // Normal table entry. In theory we could merge these too,
5459 // but duplicate entries are likely to be much less common.
5460 delete_entry = false;
5461 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5462 }
5463 return delete_entry;
5464 }
5465
5466 // Update the current section offset map during EXIDX section fix-up.
5467 // If there is no map, create one. INPUT_OFFSET is the offset of a
5468 // reference point, DELETED_BYTES is the number of deleted by in the
5469 // section so far. If DELETE_ENTRY is true, the reference point and
5470 // all offsets after the previous reference point are discarded.
5471
5472 void
5473 Arm_exidx_fixup::update_offset_map(
5474 section_offset_type input_offset,
5475 section_size_type deleted_bytes,
5476 bool delete_entry)
5477 {
5478 if (this->section_offset_map_ == NULL)
5479 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5480 section_offset_type output_offset;
5481 if (delete_entry)
5482 output_offset = Arm_exidx_input_section::invalid_offset;
5483 else
5484 output_offset = input_offset - deleted_bytes;
5485 (*this->section_offset_map_)[input_offset] = output_offset;
5486 }
5487
5488 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5489 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5490 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5491 // If some entries are merged, also store a pointer to a newly created
5492 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5493 // owns the map and is responsible for releasing it after use.
5494
5495 template<bool big_endian>
5496 uint32_t
5497 Arm_exidx_fixup::process_exidx_section(
5498 const Arm_exidx_input_section* exidx_input_section,
5499 const unsigned char* section_contents,
5500 section_size_type section_size,
5501 Arm_exidx_section_offset_map** psection_offset_map)
5502 {
5503 Relobj* relobj = exidx_input_section->relobj();
5504 unsigned shndx = exidx_input_section->shndx();
5505
5506 if ((section_size % 8) != 0)
5507 {
5508 // Something is wrong with this section. Better not touch it.
5509 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5510 relobj->name().c_str(), shndx);
5511 this->last_input_section_ = exidx_input_section;
5512 this->last_unwind_type_ = UT_NONE;
5513 return 0;
5514 }
5515
5516 uint32_t deleted_bytes = 0;
5517 bool prev_delete_entry = false;
5518 gold_assert(this->section_offset_map_ == NULL);
5519
5520 for (section_size_type i = 0; i < section_size; i += 8)
5521 {
5522 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5523 const Valtype* wv =
5524 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5525 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5526
5527 bool delete_entry = this->process_exidx_entry(second_word);
5528
5529 // Entry deletion causes changes in output offsets. We use a std::map
5530 // to record these. And entry (x, y) means input offset x
5531 // is mapped to output offset y. If y is invalid_offset, then x is
5532 // dropped in the output. Because of the way std::map::lower_bound
5533 // works, we record the last offset in a region w.r.t to keeping or
5534 // dropping. If there is no entry (x0, y0) for an input offset x0,
5535 // the output offset y0 of it is determined by the output offset y1 of
5536 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5537 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5538 // y0 is also -1.
5539 if (delete_entry != prev_delete_entry && i != 0)
5540 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5541
5542 // Update total deleted bytes for this entry.
5543 if (delete_entry)
5544 deleted_bytes += 8;
5545
5546 prev_delete_entry = delete_entry;
5547 }
5548
5549 // If section offset map is not NULL, make an entry for the end of
5550 // section.
5551 if (this->section_offset_map_ != NULL)
5552 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5553
5554 *psection_offset_map = this->section_offset_map_;
5555 this->section_offset_map_ = NULL;
5556 this->last_input_section_ = exidx_input_section;
5557
5558 // Set the first output text section so that we can link the EXIDX output
5559 // section to it. Ignore any EXIDX input section that is completely merged.
5560 if (this->first_output_text_section_ == NULL
5561 && deleted_bytes != section_size)
5562 {
5563 unsigned int link = exidx_input_section->link();
5564 Output_section* os = relobj->output_section(link);
5565 gold_assert(os != NULL);
5566 this->first_output_text_section_ = os;
5567 }
5568
5569 return deleted_bytes;
5570 }
5571
5572 // Arm_output_section methods.
5573
5574 // Create a stub group for input sections from BEGIN to END. OWNER
5575 // points to the input section to be the owner a new stub table.
5576
5577 template<bool big_endian>
5578 void
5579 Arm_output_section<big_endian>::create_stub_group(
5580 Input_section_list::const_iterator begin,
5581 Input_section_list::const_iterator end,
5582 Input_section_list::const_iterator owner,
5583 Target_arm<big_endian>* target,
5584 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5585 const Task* task)
5586 {
5587 // We use a different kind of relaxed section in an EXIDX section.
5588 // The static casting from Output_relaxed_input_section to
5589 // Arm_input_section is invalid in an EXIDX section. We are okay
5590 // because we should not be calling this for an EXIDX section.
5591 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5592
5593 // Currently we convert ordinary input sections into relaxed sections only
5594 // at this point but we may want to support creating relaxed input section
5595 // very early. So we check here to see if owner is already a relaxed
5596 // section.
5597
5598 Arm_input_section<big_endian>* arm_input_section;
5599 if (owner->is_relaxed_input_section())
5600 {
5601 arm_input_section =
5602 Arm_input_section<big_endian>::as_arm_input_section(
5603 owner->relaxed_input_section());
5604 }
5605 else
5606 {
5607 gold_assert(owner->is_input_section());
5608 // Create a new relaxed input section. We need to lock the original
5609 // file.
5610 Task_lock_obj<Object> tl(task, owner->relobj());
5611 arm_input_section =
5612 target->new_arm_input_section(owner->relobj(), owner->shndx());
5613 new_relaxed_sections->push_back(arm_input_section);
5614 }
5615
5616 // Create a stub table.
5617 Stub_table<big_endian>* stub_table =
5618 target->new_stub_table(arm_input_section);
5619
5620 arm_input_section->set_stub_table(stub_table);
5621
5622 Input_section_list::const_iterator p = begin;
5623 Input_section_list::const_iterator prev_p;
5624
5625 // Look for input sections or relaxed input sections in [begin ... end].
5626 do
5627 {
5628 if (p->is_input_section() || p->is_relaxed_input_section())
5629 {
5630 // The stub table information for input sections live
5631 // in their objects.
5632 Arm_relobj<big_endian>* arm_relobj =
5633 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5634 arm_relobj->set_stub_table(p->shndx(), stub_table);
5635 }
5636 prev_p = p++;
5637 }
5638 while (prev_p != end);
5639 }
5640
5641 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5642 // of stub groups. We grow a stub group by adding input section until the
5643 // size is just below GROUP_SIZE. The last input section will be converted
5644 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5645 // input section after the stub table, effectively double the group size.
5646 //
5647 // This is similar to the group_sections() function in elf32-arm.c but is
5648 // implemented differently.
5649
5650 template<bool big_endian>
5651 void
5652 Arm_output_section<big_endian>::group_sections(
5653 section_size_type group_size,
5654 bool stubs_always_after_branch,
5655 Target_arm<big_endian>* target,
5656 const Task* task)
5657 {
5658 // States for grouping.
5659 typedef enum
5660 {
5661 // No group is being built.
5662 NO_GROUP,
5663 // A group is being built but the stub table is not found yet.
5664 // We keep group a stub group until the size is just under GROUP_SIZE.
5665 // The last input section in the group will be used as the stub table.
5666 FINDING_STUB_SECTION,
5667 // A group is being built and we have already found a stub table.
5668 // We enter this state to grow a stub group by adding input section
5669 // after the stub table. This effectively doubles the group size.
5670 HAS_STUB_SECTION
5671 } State;
5672
5673 // Any newly created relaxed sections are stored here.
5674 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5675
5676 State state = NO_GROUP;
5677 section_size_type off = 0;
5678 section_size_type group_begin_offset = 0;
5679 section_size_type group_end_offset = 0;
5680 section_size_type stub_table_end_offset = 0;
5681 Input_section_list::const_iterator group_begin =
5682 this->input_sections().end();
5683 Input_section_list::const_iterator stub_table =
5684 this->input_sections().end();
5685 Input_section_list::const_iterator group_end = this->input_sections().end();
5686 for (Input_section_list::const_iterator p = this->input_sections().begin();
5687 p != this->input_sections().end();
5688 ++p)
5689 {
5690 section_size_type section_begin_offset =
5691 align_address(off, p->addralign());
5692 section_size_type section_end_offset =
5693 section_begin_offset + p->data_size();
5694
5695 // Check to see if we should group the previously seen sections.
5696 switch (state)
5697 {
5698 case NO_GROUP:
5699 break;
5700
5701 case FINDING_STUB_SECTION:
5702 // Adding this section makes the group larger than GROUP_SIZE.
5703 if (section_end_offset - group_begin_offset >= group_size)
5704 {
5705 if (stubs_always_after_branch)
5706 {
5707 gold_assert(group_end != this->input_sections().end());
5708 this->create_stub_group(group_begin, group_end, group_end,
5709 target, &new_relaxed_sections,
5710 task);
5711 state = NO_GROUP;
5712 }
5713 else
5714 {
5715 // But wait, there's more! Input sections up to
5716 // stub_group_size bytes after the stub table can be
5717 // handled by it too.
5718 state = HAS_STUB_SECTION;
5719 stub_table = group_end;
5720 stub_table_end_offset = group_end_offset;
5721 }
5722 }
5723 break;
5724
5725 case HAS_STUB_SECTION:
5726 // Adding this section makes the post stub-section group larger
5727 // than GROUP_SIZE.
5728 if (section_end_offset - stub_table_end_offset >= group_size)
5729 {
5730 gold_assert(group_end != this->input_sections().end());
5731 this->create_stub_group(group_begin, group_end, stub_table,
5732 target, &new_relaxed_sections, task);
5733 state = NO_GROUP;
5734 }
5735 break;
5736
5737 default:
5738 gold_unreachable();
5739 }
5740
5741 // If we see an input section and currently there is no group, start
5742 // a new one. Skip any empty sections. We look at the data size
5743 // instead of calling p->relobj()->section_size() to avoid locking.
5744 if ((p->is_input_section() || p->is_relaxed_input_section())
5745 && (p->data_size() != 0))
5746 {
5747 if (state == NO_GROUP)
5748 {
5749 state = FINDING_STUB_SECTION;
5750 group_begin = p;
5751 group_begin_offset = section_begin_offset;
5752 }
5753
5754 // Keep track of the last input section seen.
5755 group_end = p;
5756 group_end_offset = section_end_offset;
5757 }
5758
5759 off = section_end_offset;
5760 }
5761
5762 // Create a stub group for any ungrouped sections.
5763 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5764 {
5765 gold_assert(group_end != this->input_sections().end());
5766 this->create_stub_group(group_begin, group_end,
5767 (state == FINDING_STUB_SECTION
5768 ? group_end
5769 : stub_table),
5770 target, &new_relaxed_sections, task);
5771 }
5772
5773 // Convert input section into relaxed input section in a batch.
5774 if (!new_relaxed_sections.empty())
5775 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5776
5777 // Update the section offsets
5778 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5779 {
5780 Arm_relobj<big_endian>* arm_relobj =
5781 Arm_relobj<big_endian>::as_arm_relobj(
5782 new_relaxed_sections[i]->relobj());
5783 unsigned int shndx = new_relaxed_sections[i]->shndx();
5784 // Tell Arm_relobj that this input section is converted.
5785 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5786 }
5787 }
5788
5789 // Append non empty text sections in this to LIST in ascending
5790 // order of their position in this.
5791
5792 template<bool big_endian>
5793 void
5794 Arm_output_section<big_endian>::append_text_sections_to_list(
5795 Text_section_list* list)
5796 {
5797 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5798
5799 for (Input_section_list::const_iterator p = this->input_sections().begin();
5800 p != this->input_sections().end();
5801 ++p)
5802 {
5803 // We only care about plain or relaxed input sections. We also
5804 // ignore any merged sections.
5805 if (p->is_input_section() || p->is_relaxed_input_section())
5806 list->push_back(Text_section_list::value_type(p->relobj(),
5807 p->shndx()));
5808 }
5809 }
5810
5811 template<bool big_endian>
5812 void
5813 Arm_output_section<big_endian>::fix_exidx_coverage(
5814 Layout* layout,
5815 const Text_section_list& sorted_text_sections,
5816 Symbol_table* symtab,
5817 bool merge_exidx_entries,
5818 const Task* task)
5819 {
5820 // We should only do this for the EXIDX output section.
5821 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5822
5823 // We don't want the relaxation loop to undo these changes, so we discard
5824 // the current saved states and take another one after the fix-up.
5825 this->discard_states();
5826
5827 // Remove all input sections.
5828 uint64_t address = this->address();
5829 typedef std::list<Output_section::Input_section> Input_section_list;
5830 Input_section_list input_sections;
5831 this->reset_address_and_file_offset();
5832 this->get_input_sections(address, std::string(""), &input_sections);
5833
5834 if (!this->input_sections().empty())
5835 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5836
5837 // Go through all the known input sections and record them.
5838 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5839 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5840 Section_id_hash> Text_to_exidx_map;
5841 Text_to_exidx_map text_to_exidx_map;
5842 for (Input_section_list::const_iterator p = input_sections.begin();
5843 p != input_sections.end();
5844 ++p)
5845 {
5846 // This should never happen. At this point, we should only see
5847 // plain EXIDX input sections.
5848 gold_assert(!p->is_relaxed_input_section());
5849 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5850 }
5851
5852 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5853
5854 // Go over the sorted text sections.
5855 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5856 Section_id_set processed_input_sections;
5857 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5858 p != sorted_text_sections.end();
5859 ++p)
5860 {
5861 Relobj* relobj = p->first;
5862 unsigned int shndx = p->second;
5863
5864 Arm_relobj<big_endian>* arm_relobj =
5865 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5866 const Arm_exidx_input_section* exidx_input_section =
5867 arm_relobj->exidx_input_section_by_link(shndx);
5868
5869 // If this text section has no EXIDX section or if the EXIDX section
5870 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5871 // of the last seen EXIDX section.
5872 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5873 {
5874 exidx_fixup.add_exidx_cantunwind_as_needed();
5875 continue;
5876 }
5877
5878 Relobj* exidx_relobj = exidx_input_section->relobj();
5879 unsigned int exidx_shndx = exidx_input_section->shndx();
5880 Section_id sid(exidx_relobj, exidx_shndx);
5881 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5882 if (iter == text_to_exidx_map.end())
5883 {
5884 // This is odd. We have not seen this EXIDX input section before.
5885 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5886 // issue a warning instead. We assume the user knows what he
5887 // or she is doing. Otherwise, this is an error.
5888 if (layout->script_options()->saw_sections_clause())
5889 gold_warning(_("unwinding may not work because EXIDX input section"
5890 " %u of %s is not in EXIDX output section"),
5891 exidx_shndx, exidx_relobj->name().c_str());
5892 else
5893 gold_error(_("unwinding may not work because EXIDX input section"
5894 " %u of %s is not in EXIDX output section"),
5895 exidx_shndx, exidx_relobj->name().c_str());
5896
5897 exidx_fixup.add_exidx_cantunwind_as_needed();
5898 continue;
5899 }
5900
5901 // We need to access the contents of the EXIDX section, lock the
5902 // object here.
5903 Task_lock_obj<Object> tl(task, exidx_relobj);
5904 section_size_type exidx_size;
5905 const unsigned char* exidx_contents =
5906 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5907
5908 // Fix up coverage and append input section to output data list.
5909 Arm_exidx_section_offset_map* section_offset_map = NULL;
5910 uint32_t deleted_bytes =
5911 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5912 exidx_contents,
5913 exidx_size,
5914 &section_offset_map);
5915
5916 if (deleted_bytes == exidx_input_section->size())
5917 {
5918 // The whole EXIDX section got merged. Remove it from output.
5919 gold_assert(section_offset_map == NULL);
5920 exidx_relobj->set_output_section(exidx_shndx, NULL);
5921
5922 // All local symbols defined in this input section will be dropped.
5923 // We need to adjust output local symbol count.
5924 arm_relobj->set_output_local_symbol_count_needs_update();
5925 }
5926 else if (deleted_bytes > 0)
5927 {
5928 // Some entries are merged. We need to convert this EXIDX input
5929 // section into a relaxed section.
5930 gold_assert(section_offset_map != NULL);
5931
5932 Arm_exidx_merged_section* merged_section =
5933 new Arm_exidx_merged_section(*exidx_input_section,
5934 *section_offset_map, deleted_bytes);
5935 merged_section->build_contents(exidx_contents, exidx_size);
5936
5937 const std::string secname = exidx_relobj->section_name(exidx_shndx);
5938 this->add_relaxed_input_section(layout, merged_section, secname);
5939 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5940
5941 // All local symbols defined in discarded portions of this input
5942 // section will be dropped. We need to adjust output local symbol
5943 // count.
5944 arm_relobj->set_output_local_symbol_count_needs_update();
5945 }
5946 else
5947 {
5948 // Just add back the EXIDX input section.
5949 gold_assert(section_offset_map == NULL);
5950 const Output_section::Input_section* pis = iter->second;
5951 gold_assert(pis->is_input_section());
5952 this->add_script_input_section(*pis);
5953 }
5954
5955 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5956 }
5957
5958 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5959 exidx_fixup.add_exidx_cantunwind_as_needed();
5960
5961 // Remove any known EXIDX input sections that are not processed.
5962 for (Input_section_list::const_iterator p = input_sections.begin();
5963 p != input_sections.end();
5964 ++p)
5965 {
5966 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5967 == processed_input_sections.end())
5968 {
5969 // We discard a known EXIDX section because its linked
5970 // text section has been folded by ICF. We also discard an
5971 // EXIDX section with error, the output does not matter in this
5972 // case. We do this to avoid triggering asserts.
5973 Arm_relobj<big_endian>* arm_relobj =
5974 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5975 const Arm_exidx_input_section* exidx_input_section =
5976 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5977 gold_assert(exidx_input_section != NULL);
5978 if (!exidx_input_section->has_errors())
5979 {
5980 unsigned int text_shndx = exidx_input_section->link();
5981 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5982 }
5983
5984 // Remove this from link. We also need to recount the
5985 // local symbols.
5986 p->relobj()->set_output_section(p->shndx(), NULL);
5987 arm_relobj->set_output_local_symbol_count_needs_update();
5988 }
5989 }
5990
5991 // Link exidx output section to the first seen output section and
5992 // set correct entry size.
5993 this->set_link_section(exidx_fixup.first_output_text_section());
5994 this->set_entsize(8);
5995
5996 // Make changes permanent.
5997 this->save_states();
5998 this->set_section_offsets_need_adjustment();
5999 }
6000
6001 // Link EXIDX output sections to text output sections.
6002
6003 template<bool big_endian>
6004 void
6005 Arm_output_section<big_endian>::set_exidx_section_link()
6006 {
6007 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6008 if (!this->input_sections().empty())
6009 {
6010 Input_section_list::const_iterator p = this->input_sections().begin();
6011 Arm_relobj<big_endian>* arm_relobj =
6012 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6013 unsigned exidx_shndx = p->shndx();
6014 const Arm_exidx_input_section* exidx_input_section =
6015 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6016 gold_assert(exidx_input_section != NULL);
6017 unsigned int text_shndx = exidx_input_section->link();
6018 Output_section* os = arm_relobj->output_section(text_shndx);
6019 this->set_link_section(os);
6020 }
6021 }
6022
6023 // Arm_relobj methods.
6024
6025 // Determine if an input section is scannable for stub processing. SHDR is
6026 // the header of the section and SHNDX is the section index. OS is the output
6027 // section for the input section and SYMTAB is the global symbol table used to
6028 // look up ICF information.
6029
6030 template<bool big_endian>
6031 bool
6032 Arm_relobj<big_endian>::section_is_scannable(
6033 const elfcpp::Shdr<32, big_endian>& shdr,
6034 unsigned int shndx,
6035 const Output_section* os,
6036 const Symbol_table* symtab)
6037 {
6038 // Skip any empty sections, unallocated sections or sections whose
6039 // type are not SHT_PROGBITS.
6040 if (shdr.get_sh_size() == 0
6041 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6042 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6043 return false;
6044
6045 // Skip any discarded or ICF'ed sections.
6046 if (os == NULL || symtab->is_section_folded(this, shndx))
6047 return false;
6048
6049 // If this requires special offset handling, check to see if it is
6050 // a relaxed section. If this is not, then it is a merged section that
6051 // we cannot handle.
6052 if (this->is_output_section_offset_invalid(shndx))
6053 {
6054 const Output_relaxed_input_section* poris =
6055 os->find_relaxed_input_section(this, shndx);
6056 if (poris == NULL)
6057 return false;
6058 }
6059
6060 return true;
6061 }
6062
6063 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6064 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6065
6066 template<bool big_endian>
6067 bool
6068 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6069 const elfcpp::Shdr<32, big_endian>& shdr,
6070 const Relobj::Output_sections& out_sections,
6071 const Symbol_table* symtab,
6072 const unsigned char* pshdrs)
6073 {
6074 unsigned int sh_type = shdr.get_sh_type();
6075 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6076 return false;
6077
6078 // Ignore empty section.
6079 off_t sh_size = shdr.get_sh_size();
6080 if (sh_size == 0)
6081 return false;
6082
6083 // Ignore reloc section with unexpected symbol table. The
6084 // error will be reported in the final link.
6085 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6086 return false;
6087
6088 unsigned int reloc_size;
6089 if (sh_type == elfcpp::SHT_REL)
6090 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6091 else
6092 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6093
6094 // Ignore reloc section with unexpected entsize or uneven size.
6095 // The error will be reported in the final link.
6096 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6097 return false;
6098
6099 // Ignore reloc section with bad info. This error will be
6100 // reported in the final link.
6101 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6102 if (index >= this->shnum())
6103 return false;
6104
6105 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6106 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6107 return this->section_is_scannable(text_shdr, index,
6108 out_sections[index], symtab);
6109 }
6110
6111 // Return the output address of either a plain input section or a relaxed
6112 // input section. SHNDX is the section index. We define and use this
6113 // instead of calling Output_section::output_address because that is slow
6114 // for large output.
6115
6116 template<bool big_endian>
6117 Arm_address
6118 Arm_relobj<big_endian>::simple_input_section_output_address(
6119 unsigned int shndx,
6120 Output_section* os)
6121 {
6122 if (this->is_output_section_offset_invalid(shndx))
6123 {
6124 const Output_relaxed_input_section* poris =
6125 os->find_relaxed_input_section(this, shndx);
6126 // We do not handle merged sections here.
6127 gold_assert(poris != NULL);
6128 return poris->address();
6129 }
6130 else
6131 return os->address() + this->get_output_section_offset(shndx);
6132 }
6133
6134 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6135 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6136
6137 template<bool big_endian>
6138 bool
6139 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6140 const elfcpp::Shdr<32, big_endian>& shdr,
6141 unsigned int shndx,
6142 Output_section* os,
6143 const Symbol_table* symtab)
6144 {
6145 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6146 return false;
6147
6148 // If the section does not cross any 4K-boundaries, it does not need to
6149 // be scanned.
6150 Arm_address address = this->simple_input_section_output_address(shndx, os);
6151 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6152 return false;
6153
6154 return true;
6155 }
6156
6157 // Scan a section for Cortex-A8 workaround.
6158
6159 template<bool big_endian>
6160 void
6161 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6162 const elfcpp::Shdr<32, big_endian>& shdr,
6163 unsigned int shndx,
6164 Output_section* os,
6165 Target_arm<big_endian>* arm_target)
6166 {
6167 // Look for the first mapping symbol in this section. It should be
6168 // at (shndx, 0).
6169 Mapping_symbol_position section_start(shndx, 0);
6170 typename Mapping_symbols_info::const_iterator p =
6171 this->mapping_symbols_info_.lower_bound(section_start);
6172
6173 // There are no mapping symbols for this section. Treat it as a data-only
6174 // section. Issue a warning if section is marked as containing
6175 // instructions.
6176 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6177 {
6178 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6179 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6180 "erratum because it has no mapping symbols."),
6181 shndx, this->name().c_str());
6182 return;
6183 }
6184
6185 Arm_address output_address =
6186 this->simple_input_section_output_address(shndx, os);
6187
6188 // Get the section contents.
6189 section_size_type input_view_size = 0;
6190 const unsigned char* input_view =
6191 this->section_contents(shndx, &input_view_size, false);
6192
6193 // We need to go through the mapping symbols to determine what to
6194 // scan. There are two reasons. First, we should look at THUMB code and
6195 // THUMB code only. Second, we only want to look at the 4K-page boundary
6196 // to speed up the scanning.
6197
6198 while (p != this->mapping_symbols_info_.end()
6199 && p->first.first == shndx)
6200 {
6201 typename Mapping_symbols_info::const_iterator next =
6202 this->mapping_symbols_info_.upper_bound(p->first);
6203
6204 // Only scan part of a section with THUMB code.
6205 if (p->second == 't')
6206 {
6207 // Determine the end of this range.
6208 section_size_type span_start =
6209 convert_to_section_size_type(p->first.second);
6210 section_size_type span_end;
6211 if (next != this->mapping_symbols_info_.end()
6212 && next->first.first == shndx)
6213 span_end = convert_to_section_size_type(next->first.second);
6214 else
6215 span_end = convert_to_section_size_type(shdr.get_sh_size());
6216
6217 if (((span_start + output_address) & ~0xfffUL)
6218 != ((span_end + output_address - 1) & ~0xfffUL))
6219 {
6220 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6221 span_start, span_end,
6222 input_view,
6223 output_address);
6224 }
6225 }
6226
6227 p = next;
6228 }
6229 }
6230
6231 // Scan relocations for stub generation.
6232
6233 template<bool big_endian>
6234 void
6235 Arm_relobj<big_endian>::scan_sections_for_stubs(
6236 Target_arm<big_endian>* arm_target,
6237 const Symbol_table* symtab,
6238 const Layout* layout)
6239 {
6240 unsigned int shnum = this->shnum();
6241 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6242
6243 // Read the section headers.
6244 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6245 shnum * shdr_size,
6246 true, true);
6247
6248 // To speed up processing, we set up hash tables for fast lookup of
6249 // input offsets to output addresses.
6250 this->initialize_input_to_output_maps();
6251
6252 const Relobj::Output_sections& out_sections(this->output_sections());
6253
6254 Relocate_info<32, big_endian> relinfo;
6255 relinfo.symtab = symtab;
6256 relinfo.layout = layout;
6257 relinfo.object = this;
6258
6259 // Do relocation stubs scanning.
6260 const unsigned char* p = pshdrs + shdr_size;
6261 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6262 {
6263 const elfcpp::Shdr<32, big_endian> shdr(p);
6264 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6265 pshdrs))
6266 {
6267 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6268 Arm_address output_offset = this->get_output_section_offset(index);
6269 Arm_address output_address;
6270 if (output_offset != invalid_address)
6271 output_address = out_sections[index]->address() + output_offset;
6272 else
6273 {
6274 // Currently this only happens for a relaxed section.
6275 const Output_relaxed_input_section* poris =
6276 out_sections[index]->find_relaxed_input_section(this, index);
6277 gold_assert(poris != NULL);
6278 output_address = poris->address();
6279 }
6280
6281 // Get the relocations.
6282 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6283 shdr.get_sh_size(),
6284 true, false);
6285
6286 // Get the section contents. This does work for the case in which
6287 // we modify the contents of an input section. We need to pass the
6288 // output view under such circumstances.
6289 section_size_type input_view_size = 0;
6290 const unsigned char* input_view =
6291 this->section_contents(index, &input_view_size, false);
6292
6293 relinfo.reloc_shndx = i;
6294 relinfo.data_shndx = index;
6295 unsigned int sh_type = shdr.get_sh_type();
6296 unsigned int reloc_size;
6297 if (sh_type == elfcpp::SHT_REL)
6298 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6299 else
6300 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6301
6302 Output_section* os = out_sections[index];
6303 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6304 shdr.get_sh_size() / reloc_size,
6305 os,
6306 output_offset == invalid_address,
6307 input_view, output_address,
6308 input_view_size);
6309 }
6310 }
6311
6312 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6313 // after its relocation section, if there is one, is processed for
6314 // relocation stubs. Merging this loop with the one above would have been
6315 // complicated since we would have had to make sure that relocation stub
6316 // scanning is done first.
6317 if (arm_target->fix_cortex_a8())
6318 {
6319 const unsigned char* p = pshdrs + shdr_size;
6320 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6321 {
6322 const elfcpp::Shdr<32, big_endian> shdr(p);
6323 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6324 out_sections[i],
6325 symtab))
6326 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6327 arm_target);
6328 }
6329 }
6330
6331 // After we've done the relocations, we release the hash tables,
6332 // since we no longer need them.
6333 this->free_input_to_output_maps();
6334 }
6335
6336 // Count the local symbols. The ARM backend needs to know if a symbol
6337 // is a THUMB function or not. For global symbols, it is easy because
6338 // the Symbol object keeps the ELF symbol type. For local symbol it is
6339 // harder because we cannot access this information. So we override the
6340 // do_count_local_symbol in parent and scan local symbols to mark
6341 // THUMB functions. This is not the most efficient way but I do not want to
6342 // slow down other ports by calling a per symbol target hook inside
6343 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6344
6345 template<bool big_endian>
6346 void
6347 Arm_relobj<big_endian>::do_count_local_symbols(
6348 Stringpool_template<char>* pool,
6349 Stringpool_template<char>* dynpool)
6350 {
6351 // We need to fix-up the values of any local symbols whose type are
6352 // STT_ARM_TFUNC.
6353
6354 // Ask parent to count the local symbols.
6355 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6356 const unsigned int loccount = this->local_symbol_count();
6357 if (loccount == 0)
6358 return;
6359
6360 // Initialize the thumb function bit-vector.
6361 std::vector<bool> empty_vector(loccount, false);
6362 this->local_symbol_is_thumb_function_.swap(empty_vector);
6363
6364 // Read the symbol table section header.
6365 const unsigned int symtab_shndx = this->symtab_shndx();
6366 elfcpp::Shdr<32, big_endian>
6367 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6368 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6369
6370 // Read the local symbols.
6371 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6372 gold_assert(loccount == symtabshdr.get_sh_info());
6373 off_t locsize = loccount * sym_size;
6374 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6375 locsize, true, true);
6376
6377 // For mapping symbol processing, we need to read the symbol names.
6378 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6379 if (strtab_shndx >= this->shnum())
6380 {
6381 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6382 return;
6383 }
6384
6385 elfcpp::Shdr<32, big_endian>
6386 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6387 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6388 {
6389 this->error(_("symbol table name section has wrong type: %u"),
6390 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6391 return;
6392 }
6393 const char* pnames =
6394 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6395 strtabshdr.get_sh_size(),
6396 false, false));
6397
6398 // Loop over the local symbols and mark any local symbols pointing
6399 // to THUMB functions.
6400
6401 // Skip the first dummy symbol.
6402 psyms += sym_size;
6403 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6404 this->local_values();
6405 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6406 {
6407 elfcpp::Sym<32, big_endian> sym(psyms);
6408 elfcpp::STT st_type = sym.get_st_type();
6409 Symbol_value<32>& lv((*plocal_values)[i]);
6410 Arm_address input_value = lv.input_value();
6411
6412 // Check to see if this is a mapping symbol.
6413 const char* sym_name = pnames + sym.get_st_name();
6414 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6415 {
6416 bool is_ordinary;
6417 unsigned int input_shndx =
6418 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6419 gold_assert(is_ordinary);
6420
6421 // Strip of LSB in case this is a THUMB symbol.
6422 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6423 this->mapping_symbols_info_[msp] = sym_name[1];
6424 }
6425
6426 if (st_type == elfcpp::STT_ARM_TFUNC
6427 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6428 {
6429 // This is a THUMB function. Mark this and canonicalize the
6430 // symbol value by setting LSB.
6431 this->local_symbol_is_thumb_function_[i] = true;
6432 if ((input_value & 1) == 0)
6433 lv.set_input_value(input_value | 1);
6434 }
6435 }
6436 }
6437
6438 // Relocate sections.
6439 template<bool big_endian>
6440 void
6441 Arm_relobj<big_endian>::do_relocate_sections(
6442 const Symbol_table* symtab,
6443 const Layout* layout,
6444 const unsigned char* pshdrs,
6445 Output_file* of,
6446 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6447 {
6448 // Call parent to relocate sections.
6449 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6450 pshdrs, of, pviews);
6451
6452 // We do not generate stubs if doing a relocatable link.
6453 if (parameters->options().relocatable())
6454 return;
6455
6456 // Relocate stub tables.
6457 unsigned int shnum = this->shnum();
6458
6459 Target_arm<big_endian>* arm_target =
6460 Target_arm<big_endian>::default_target();
6461
6462 Relocate_info<32, big_endian> relinfo;
6463 relinfo.symtab = symtab;
6464 relinfo.layout = layout;
6465 relinfo.object = this;
6466
6467 for (unsigned int i = 1; i < shnum; ++i)
6468 {
6469 Arm_input_section<big_endian>* arm_input_section =
6470 arm_target->find_arm_input_section(this, i);
6471
6472 if (arm_input_section != NULL
6473 && arm_input_section->is_stub_table_owner()
6474 && !arm_input_section->stub_table()->empty())
6475 {
6476 // We cannot discard a section if it owns a stub table.
6477 Output_section* os = this->output_section(i);
6478 gold_assert(os != NULL);
6479
6480 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6481 relinfo.reloc_shdr = NULL;
6482 relinfo.data_shndx = i;
6483 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6484
6485 gold_assert((*pviews)[i].view != NULL);
6486
6487 // We are passed the output section view. Adjust it to cover the
6488 // stub table only.
6489 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6490 gold_assert((stub_table->address() >= (*pviews)[i].address)
6491 && ((stub_table->address() + stub_table->data_size())
6492 <= (*pviews)[i].address + (*pviews)[i].view_size));
6493
6494 off_t offset = stub_table->address() - (*pviews)[i].address;
6495 unsigned char* view = (*pviews)[i].view + offset;
6496 Arm_address address = stub_table->address();
6497 section_size_type view_size = stub_table->data_size();
6498
6499 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6500 view_size);
6501 }
6502
6503 // Apply Cortex A8 workaround if applicable.
6504 if (this->section_has_cortex_a8_workaround(i))
6505 {
6506 unsigned char* view = (*pviews)[i].view;
6507 Arm_address view_address = (*pviews)[i].address;
6508 section_size_type view_size = (*pviews)[i].view_size;
6509 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6510
6511 // Adjust view to cover section.
6512 Output_section* os = this->output_section(i);
6513 gold_assert(os != NULL);
6514 Arm_address section_address =
6515 this->simple_input_section_output_address(i, os);
6516 uint64_t section_size = this->section_size(i);
6517
6518 gold_assert(section_address >= view_address
6519 && ((section_address + section_size)
6520 <= (view_address + view_size)));
6521
6522 unsigned char* section_view = view + (section_address - view_address);
6523
6524 // Apply the Cortex-A8 workaround to the output address range
6525 // corresponding to this input section.
6526 stub_table->apply_cortex_a8_workaround_to_address_range(
6527 arm_target,
6528 section_view,
6529 section_address,
6530 section_size);
6531 }
6532 }
6533 }
6534
6535 // Find the linked text section of an EXIDX section by looking at the first
6536 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6537 // must be linked to its associated code section via the sh_link field of
6538 // its section header. However, some tools are broken and the link is not
6539 // always set. LD just drops such an EXIDX section silently, causing the
6540 // associated code not unwindabled. Here we try a little bit harder to
6541 // discover the linked code section.
6542 //
6543 // PSHDR points to the section header of a relocation section of an EXIDX
6544 // section. If we can find a linked text section, return true and
6545 // store the text section index in the location PSHNDX. Otherwise
6546 // return false.
6547
6548 template<bool big_endian>
6549 bool
6550 Arm_relobj<big_endian>::find_linked_text_section(
6551 const unsigned char* pshdr,
6552 const unsigned char* psyms,
6553 unsigned int* pshndx)
6554 {
6555 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6556
6557 // If there is no relocation, we cannot find the linked text section.
6558 size_t reloc_size;
6559 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6560 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6561 else
6562 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6563 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6564
6565 // Get the relocations.
6566 const unsigned char* prelocs =
6567 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6568
6569 // Find the REL31 relocation for the first word of the first EXIDX entry.
6570 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6571 {
6572 Arm_address r_offset;
6573 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6574 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6575 {
6576 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6577 r_info = reloc.get_r_info();
6578 r_offset = reloc.get_r_offset();
6579 }
6580 else
6581 {
6582 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6583 r_info = reloc.get_r_info();
6584 r_offset = reloc.get_r_offset();
6585 }
6586
6587 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6588 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6589 continue;
6590
6591 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6592 if (r_sym == 0
6593 || r_sym >= this->local_symbol_count()
6594 || r_offset != 0)
6595 continue;
6596
6597 // This is the relocation for the first word of the first EXIDX entry.
6598 // We expect to see a local section symbol.
6599 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6600 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6601 if (sym.get_st_type() == elfcpp::STT_SECTION)
6602 {
6603 bool is_ordinary;
6604 *pshndx =
6605 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6606 gold_assert(is_ordinary);
6607 return true;
6608 }
6609 else
6610 return false;
6611 }
6612
6613 return false;
6614 }
6615
6616 // Make an EXIDX input section object for an EXIDX section whose index is
6617 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6618 // is the section index of the linked text section.
6619
6620 template<bool big_endian>
6621 void
6622 Arm_relobj<big_endian>::make_exidx_input_section(
6623 unsigned int shndx,
6624 const elfcpp::Shdr<32, big_endian>& shdr,
6625 unsigned int text_shndx,
6626 const elfcpp::Shdr<32, big_endian>& text_shdr)
6627 {
6628 // Create an Arm_exidx_input_section object for this EXIDX section.
6629 Arm_exidx_input_section* exidx_input_section =
6630 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6631 shdr.get_sh_addralign(),
6632 text_shdr.get_sh_size());
6633
6634 gold_assert(this->exidx_section_map_[shndx] == NULL);
6635 this->exidx_section_map_[shndx] = exidx_input_section;
6636
6637 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6638 {
6639 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6640 this->section_name(shndx).c_str(), shndx, text_shndx,
6641 this->name().c_str());
6642 exidx_input_section->set_has_errors();
6643 }
6644 else if (this->exidx_section_map_[text_shndx] != NULL)
6645 {
6646 unsigned other_exidx_shndx =
6647 this->exidx_section_map_[text_shndx]->shndx();
6648 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6649 "%s(%u) in %s"),
6650 this->section_name(shndx).c_str(), shndx,
6651 this->section_name(other_exidx_shndx).c_str(),
6652 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6653 text_shndx, this->name().c_str());
6654 exidx_input_section->set_has_errors();
6655 }
6656 else
6657 this->exidx_section_map_[text_shndx] = exidx_input_section;
6658
6659 // Check section flags of text section.
6660 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6661 {
6662 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6663 " in %s"),
6664 this->section_name(shndx).c_str(), shndx,
6665 this->section_name(text_shndx).c_str(), text_shndx,
6666 this->name().c_str());
6667 exidx_input_section->set_has_errors();
6668 }
6669 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6670 // I would like to make this an error but currently ld just ignores
6671 // this.
6672 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6673 "%s(%u) in %s"),
6674 this->section_name(shndx).c_str(), shndx,
6675 this->section_name(text_shndx).c_str(), text_shndx,
6676 this->name().c_str());
6677 }
6678
6679 // Read the symbol information.
6680
6681 template<bool big_endian>
6682 void
6683 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6684 {
6685 // Call parent class to read symbol information.
6686 this->base_read_symbols(sd);
6687
6688 // If this input file is a binary file, it has no processor
6689 // specific flags and attributes section.
6690 Input_file::Format format = this->input_file()->format();
6691 if (format != Input_file::FORMAT_ELF)
6692 {
6693 gold_assert(format == Input_file::FORMAT_BINARY);
6694 this->merge_flags_and_attributes_ = false;
6695 return;
6696 }
6697
6698 // Read processor-specific flags in ELF file header.
6699 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6700 elfcpp::Elf_sizes<32>::ehdr_size,
6701 true, false);
6702 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6703 this->processor_specific_flags_ = ehdr.get_e_flags();
6704
6705 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6706 // sections.
6707 std::vector<unsigned int> deferred_exidx_sections;
6708 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6709 const unsigned char* pshdrs = sd->section_headers->data();
6710 const unsigned char* ps = pshdrs + shdr_size;
6711 bool must_merge_flags_and_attributes = false;
6712 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6713 {
6714 elfcpp::Shdr<32, big_endian> shdr(ps);
6715
6716 // Sometimes an object has no contents except the section name string
6717 // table and an empty symbol table with the undefined symbol. We
6718 // don't want to merge processor-specific flags from such an object.
6719 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6720 {
6721 // Symbol table is not empty.
6722 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6723 elfcpp::Elf_sizes<32>::sym_size;
6724 if (shdr.get_sh_size() > sym_size)
6725 must_merge_flags_and_attributes = true;
6726 }
6727 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6728 // If this is neither an empty symbol table nor a string table,
6729 // be conservative.
6730 must_merge_flags_and_attributes = true;
6731
6732 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6733 {
6734 gold_assert(this->attributes_section_data_ == NULL);
6735 section_offset_type section_offset = shdr.get_sh_offset();
6736 section_size_type section_size =
6737 convert_to_section_size_type(shdr.get_sh_size());
6738 const unsigned char* view =
6739 this->get_view(section_offset, section_size, true, false);
6740 this->attributes_section_data_ =
6741 new Attributes_section_data(view, section_size);
6742 }
6743 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6744 {
6745 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6746 if (text_shndx == elfcpp::SHN_UNDEF)
6747 deferred_exidx_sections.push_back(i);
6748 else
6749 {
6750 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6751 + text_shndx * shdr_size);
6752 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6753 }
6754 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6755 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6756 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6757 this->section_name(i).c_str(), this->name().c_str());
6758 }
6759 }
6760
6761 // This is rare.
6762 if (!must_merge_flags_and_attributes)
6763 {
6764 gold_assert(deferred_exidx_sections.empty());
6765 this->merge_flags_and_attributes_ = false;
6766 return;
6767 }
6768
6769 // Some tools are broken and they do not set the link of EXIDX sections.
6770 // We look at the first relocation to figure out the linked sections.
6771 if (!deferred_exidx_sections.empty())
6772 {
6773 // We need to go over the section headers again to find the mapping
6774 // from sections being relocated to their relocation sections. This is
6775 // a bit inefficient as we could do that in the loop above. However,
6776 // we do not expect any deferred EXIDX sections normally. So we do not
6777 // want to slow down the most common path.
6778 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6779 Reloc_map reloc_map;
6780 ps = pshdrs + shdr_size;
6781 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6782 {
6783 elfcpp::Shdr<32, big_endian> shdr(ps);
6784 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6785 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6786 {
6787 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6788 if (info_shndx >= this->shnum())
6789 gold_error(_("relocation section %u has invalid info %u"),
6790 i, info_shndx);
6791 Reloc_map::value_type value(info_shndx, i);
6792 std::pair<Reloc_map::iterator, bool> result =
6793 reloc_map.insert(value);
6794 if (!result.second)
6795 gold_error(_("section %u has multiple relocation sections "
6796 "%u and %u"),
6797 info_shndx, i, reloc_map[info_shndx]);
6798 }
6799 }
6800
6801 // Read the symbol table section header.
6802 const unsigned int symtab_shndx = this->symtab_shndx();
6803 elfcpp::Shdr<32, big_endian>
6804 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6805 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6806
6807 // Read the local symbols.
6808 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6809 const unsigned int loccount = this->local_symbol_count();
6810 gold_assert(loccount == symtabshdr.get_sh_info());
6811 off_t locsize = loccount * sym_size;
6812 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6813 locsize, true, true);
6814
6815 // Process the deferred EXIDX sections.
6816 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6817 {
6818 unsigned int shndx = deferred_exidx_sections[i];
6819 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6820 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6821 Reloc_map::const_iterator it = reloc_map.find(shndx);
6822 if (it != reloc_map.end())
6823 find_linked_text_section(pshdrs + it->second * shdr_size,
6824 psyms, &text_shndx);
6825 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6826 + text_shndx * shdr_size);
6827 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6828 }
6829 }
6830 }
6831
6832 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6833 // sections for unwinding. These sections are referenced implicitly by
6834 // text sections linked in the section headers. If we ignore these implicit
6835 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6836 // will be garbage-collected incorrectly. Hence we override the same function
6837 // in the base class to handle these implicit references.
6838
6839 template<bool big_endian>
6840 void
6841 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6842 Layout* layout,
6843 Read_relocs_data* rd)
6844 {
6845 // First, call base class method to process relocations in this object.
6846 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6847
6848 // If --gc-sections is not specified, there is nothing more to do.
6849 // This happens when --icf is used but --gc-sections is not.
6850 if (!parameters->options().gc_sections())
6851 return;
6852
6853 unsigned int shnum = this->shnum();
6854 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6855 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6856 shnum * shdr_size,
6857 true, true);
6858
6859 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6860 // to these from the linked text sections.
6861 const unsigned char* ps = pshdrs + shdr_size;
6862 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6863 {
6864 elfcpp::Shdr<32, big_endian> shdr(ps);
6865 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6866 {
6867 // Found an .ARM.exidx section, add it to the set of reachable
6868 // sections from its linked text section.
6869 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6870 symtab->gc()->add_reference(this, text_shndx, this, i);
6871 }
6872 }
6873 }
6874
6875 // Update output local symbol count. Owing to EXIDX entry merging, some local
6876 // symbols will be removed in output. Adjust output local symbol count
6877 // accordingly. We can only changed the static output local symbol count. It
6878 // is too late to change the dynamic symbols.
6879
6880 template<bool big_endian>
6881 void
6882 Arm_relobj<big_endian>::update_output_local_symbol_count()
6883 {
6884 // Caller should check that this needs updating. We want caller checking
6885 // because output_local_symbol_count_needs_update() is most likely inlined.
6886 gold_assert(this->output_local_symbol_count_needs_update_);
6887
6888 gold_assert(this->symtab_shndx() != -1U);
6889 if (this->symtab_shndx() == 0)
6890 {
6891 // This object has no symbols. Weird but legal.
6892 return;
6893 }
6894
6895 // Read the symbol table section header.
6896 const unsigned int symtab_shndx = this->symtab_shndx();
6897 elfcpp::Shdr<32, big_endian>
6898 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6899 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6900
6901 // Read the local symbols.
6902 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6903 const unsigned int loccount = this->local_symbol_count();
6904 gold_assert(loccount == symtabshdr.get_sh_info());
6905 off_t locsize = loccount * sym_size;
6906 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6907 locsize, true, true);
6908
6909 // Loop over the local symbols.
6910
6911 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6912 Output_sections;
6913 const Output_sections& out_sections(this->output_sections());
6914 unsigned int shnum = this->shnum();
6915 unsigned int count = 0;
6916 // Skip the first, dummy, symbol.
6917 psyms += sym_size;
6918 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6919 {
6920 elfcpp::Sym<32, big_endian> sym(psyms);
6921
6922 Symbol_value<32>& lv((*this->local_values())[i]);
6923
6924 // This local symbol was already discarded by do_count_local_symbols.
6925 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6926 continue;
6927
6928 bool is_ordinary;
6929 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6930 &is_ordinary);
6931
6932 if (shndx < shnum)
6933 {
6934 Output_section* os = out_sections[shndx];
6935
6936 // This local symbol no longer has an output section. Discard it.
6937 if (os == NULL)
6938 {
6939 lv.set_no_output_symtab_entry();
6940 continue;
6941 }
6942
6943 // Currently we only discard parts of EXIDX input sections.
6944 // We explicitly check for a merged EXIDX input section to avoid
6945 // calling Output_section_data::output_offset unless necessary.
6946 if ((this->get_output_section_offset(shndx) == invalid_address)
6947 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6948 {
6949 section_offset_type output_offset =
6950 os->output_offset(this, shndx, lv.input_value());
6951 if (output_offset == -1)
6952 {
6953 // This symbol is defined in a part of an EXIDX input section
6954 // that is discarded due to entry merging.
6955 lv.set_no_output_symtab_entry();
6956 continue;
6957 }
6958 }
6959 }
6960
6961 ++count;
6962 }
6963
6964 this->set_output_local_symbol_count(count);
6965 this->output_local_symbol_count_needs_update_ = false;
6966 }
6967
6968 // Arm_dynobj methods.
6969
6970 // Read the symbol information.
6971
6972 template<bool big_endian>
6973 void
6974 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6975 {
6976 // Call parent class to read symbol information.
6977 this->base_read_symbols(sd);
6978
6979 // Read processor-specific flags in ELF file header.
6980 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6981 elfcpp::Elf_sizes<32>::ehdr_size,
6982 true, false);
6983 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6984 this->processor_specific_flags_ = ehdr.get_e_flags();
6985
6986 // Read the attributes section if there is one.
6987 // We read from the end because gas seems to put it near the end of
6988 // the section headers.
6989 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6990 const unsigned char* ps =
6991 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6992 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6993 {
6994 elfcpp::Shdr<32, big_endian> shdr(ps);
6995 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6996 {
6997 section_offset_type section_offset = shdr.get_sh_offset();
6998 section_size_type section_size =
6999 convert_to_section_size_type(shdr.get_sh_size());
7000 const unsigned char* view =
7001 this->get_view(section_offset, section_size, true, false);
7002 this->attributes_section_data_ =
7003 new Attributes_section_data(view, section_size);
7004 break;
7005 }
7006 }
7007 }
7008
7009 // Stub_addend_reader methods.
7010
7011 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7012
7013 template<bool big_endian>
7014 elfcpp::Elf_types<32>::Elf_Swxword
7015 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7016 unsigned int r_type,
7017 const unsigned char* view,
7018 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7019 {
7020 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7021
7022 switch (r_type)
7023 {
7024 case elfcpp::R_ARM_CALL:
7025 case elfcpp::R_ARM_JUMP24:
7026 case elfcpp::R_ARM_PLT32:
7027 {
7028 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7029 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7030 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7031 return Bits<26>::sign_extend32(val << 2);
7032 }
7033
7034 case elfcpp::R_ARM_THM_CALL:
7035 case elfcpp::R_ARM_THM_JUMP24:
7036 case elfcpp::R_ARM_THM_XPC22:
7037 {
7038 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7039 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7040 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7041 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7042 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7043 }
7044
7045 case elfcpp::R_ARM_THM_JUMP19:
7046 {
7047 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7048 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7049 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7050 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7051 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7052 }
7053
7054 default:
7055 gold_unreachable();
7056 }
7057 }
7058
7059 // Arm_output_data_got methods.
7060
7061 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7062 // The first one is initialized to be 1, which is the module index for
7063 // the main executable and the second one 0. A reloc of the type
7064 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7065 // be applied by gold. GSYM is a global symbol.
7066 //
7067 template<bool big_endian>
7068 void
7069 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7070 unsigned int got_type,
7071 Symbol* gsym)
7072 {
7073 if (gsym->has_got_offset(got_type))
7074 return;
7075
7076 // We are doing a static link. Just mark it as belong to module 1,
7077 // the executable.
7078 unsigned int got_offset = this->add_constant(1);
7079 gsym->set_got_offset(got_type, got_offset);
7080 got_offset = this->add_constant(0);
7081 this->static_relocs_.push_back(Static_reloc(got_offset,
7082 elfcpp::R_ARM_TLS_DTPOFF32,
7083 gsym));
7084 }
7085
7086 // Same as the above but for a local symbol.
7087
7088 template<bool big_endian>
7089 void
7090 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7091 unsigned int got_type,
7092 Sized_relobj_file<32, big_endian>* object,
7093 unsigned int index)
7094 {
7095 if (object->local_has_got_offset(index, got_type))
7096 return;
7097
7098 // We are doing a static link. Just mark it as belong to module 1,
7099 // the executable.
7100 unsigned int got_offset = this->add_constant(1);
7101 object->set_local_got_offset(index, got_type, got_offset);
7102 got_offset = this->add_constant(0);
7103 this->static_relocs_.push_back(Static_reloc(got_offset,
7104 elfcpp::R_ARM_TLS_DTPOFF32,
7105 object, index));
7106 }
7107
7108 template<bool big_endian>
7109 void
7110 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7111 {
7112 // Call parent to write out GOT.
7113 Output_data_got<32, big_endian>::do_write(of);
7114
7115 // We are done if there is no fix up.
7116 if (this->static_relocs_.empty())
7117 return;
7118
7119 gold_assert(parameters->doing_static_link());
7120
7121 const off_t offset = this->offset();
7122 const section_size_type oview_size =
7123 convert_to_section_size_type(this->data_size());
7124 unsigned char* const oview = of->get_output_view(offset, oview_size);
7125
7126 Output_segment* tls_segment = this->layout_->tls_segment();
7127 gold_assert(tls_segment != NULL);
7128
7129 // The thread pointer $tp points to the TCB, which is followed by the
7130 // TLS. So we need to adjust $tp relative addressing by this amount.
7131 Arm_address aligned_tcb_size =
7132 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7133
7134 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7135 {
7136 Static_reloc& reloc(this->static_relocs_[i]);
7137
7138 Arm_address value;
7139 if (!reloc.symbol_is_global())
7140 {
7141 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7142 const Symbol_value<32>* psymval =
7143 reloc.relobj()->local_symbol(reloc.index());
7144
7145 // We are doing static linking. Issue an error and skip this
7146 // relocation if the symbol is undefined or in a discarded_section.
7147 bool is_ordinary;
7148 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7149 if ((shndx == elfcpp::SHN_UNDEF)
7150 || (is_ordinary
7151 && shndx != elfcpp::SHN_UNDEF
7152 && !object->is_section_included(shndx)
7153 && !this->symbol_table_->is_section_folded(object, shndx)))
7154 {
7155 gold_error(_("undefined or discarded local symbol %u from "
7156 " object %s in GOT"),
7157 reloc.index(), reloc.relobj()->name().c_str());
7158 continue;
7159 }
7160
7161 value = psymval->value(object, 0);
7162 }
7163 else
7164 {
7165 const Symbol* gsym = reloc.symbol();
7166 gold_assert(gsym != NULL);
7167 if (gsym->is_forwarder())
7168 gsym = this->symbol_table_->resolve_forwards(gsym);
7169
7170 // We are doing static linking. Issue an error and skip this
7171 // relocation if the symbol is undefined or in a discarded_section
7172 // unless it is a weakly_undefined symbol.
7173 if ((gsym->is_defined_in_discarded_section()
7174 || gsym->is_undefined())
7175 && !gsym->is_weak_undefined())
7176 {
7177 gold_error(_("undefined or discarded symbol %s in GOT"),
7178 gsym->name());
7179 continue;
7180 }
7181
7182 if (!gsym->is_weak_undefined())
7183 {
7184 const Sized_symbol<32>* sym =
7185 static_cast<const Sized_symbol<32>*>(gsym);
7186 value = sym->value();
7187 }
7188 else
7189 value = 0;
7190 }
7191
7192 unsigned got_offset = reloc.got_offset();
7193 gold_assert(got_offset < oview_size);
7194
7195 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7196 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7197 Valtype x;
7198 switch (reloc.r_type())
7199 {
7200 case elfcpp::R_ARM_TLS_DTPOFF32:
7201 x = value;
7202 break;
7203 case elfcpp::R_ARM_TLS_TPOFF32:
7204 x = value + aligned_tcb_size;
7205 break;
7206 default:
7207 gold_unreachable();
7208 }
7209 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7210 }
7211
7212 of->write_output_view(offset, oview_size, oview);
7213 }
7214
7215 // A class to handle the PLT data.
7216 // This is an abstract base class that handles most of the linker details
7217 // but does not know the actual contents of PLT entries. The derived
7218 // classes below fill in those details.
7219
7220 template<bool big_endian>
7221 class Output_data_plt_arm : public Output_section_data
7222 {
7223 public:
7224 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7225 Reloc_section;
7226
7227 Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7228
7229 // Add an entry to the PLT.
7230 void
7231 add_entry(Symbol* gsym);
7232
7233 // Return the .rel.plt section data.
7234 const Reloc_section*
7235 rel_plt() const
7236 { return this->rel_; }
7237
7238 // Return the number of PLT entries.
7239 unsigned int
7240 entry_count() const
7241 { return this->count_; }
7242
7243 // Return the offset of the first non-reserved PLT entry.
7244 unsigned int
7245 first_plt_entry_offset() const
7246 { return this->do_first_plt_entry_offset(); }
7247
7248 // Return the size of a PLT entry.
7249 unsigned int
7250 get_plt_entry_size() const
7251 { return this->do_get_plt_entry_size(); }
7252
7253 protected:
7254 // Fill in the first PLT entry.
7255 void
7256 fill_first_plt_entry(unsigned char* pov,
7257 Arm_address got_address,
7258 Arm_address plt_address)
7259 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7260
7261 void
7262 fill_plt_entry(unsigned char* pov,
7263 Arm_address got_address,
7264 Arm_address plt_address,
7265 unsigned int got_offset,
7266 unsigned int plt_offset)
7267 { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7268
7269 virtual unsigned int
7270 do_first_plt_entry_offset() const = 0;
7271
7272 virtual unsigned int
7273 do_get_plt_entry_size() const = 0;
7274
7275 virtual void
7276 do_fill_first_plt_entry(unsigned char* pov,
7277 Arm_address got_address,
7278 Arm_address plt_address) = 0;
7279
7280 virtual void
7281 do_fill_plt_entry(unsigned char* pov,
7282 Arm_address got_address,
7283 Arm_address plt_address,
7284 unsigned int got_offset,
7285 unsigned int plt_offset) = 0;
7286
7287 void
7288 do_adjust_output_section(Output_section* os);
7289
7290 // Write to a map file.
7291 void
7292 do_print_to_mapfile(Mapfile* mapfile) const
7293 { mapfile->print_output_data(this, _("** PLT")); }
7294
7295 private:
7296 // Set the final size.
7297 void
7298 set_final_data_size()
7299 {
7300 this->set_data_size(this->first_plt_entry_offset()
7301 + this->count_ * this->get_plt_entry_size());
7302 }
7303
7304 // Write out the PLT data.
7305 void
7306 do_write(Output_file*);
7307
7308 // The reloc section.
7309 Reloc_section* rel_;
7310 // The .got.plt section.
7311 Output_data_space* got_plt_;
7312 // The number of PLT entries.
7313 unsigned int count_;
7314 };
7315
7316 // Create the PLT section. The ordinary .got section is an argument,
7317 // since we need to refer to the start. We also create our own .got
7318 // section just for PLT entries.
7319
7320 template<bool big_endian>
7321 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7322 uint64_t addralign,
7323 Output_data_space* got_plt)
7324 : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7325 {
7326 this->rel_ = new Reloc_section(false);
7327 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7328 elfcpp::SHF_ALLOC, this->rel_,
7329 ORDER_DYNAMIC_PLT_RELOCS, false);
7330 }
7331
7332 template<bool big_endian>
7333 void
7334 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7335 {
7336 os->set_entsize(0);
7337 }
7338
7339 // Add an entry to the PLT.
7340
7341 template<bool big_endian>
7342 void
7343 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7344 {
7345 gold_assert(!gsym->has_plt_offset());
7346
7347 // Note that when setting the PLT offset we skip the initial
7348 // reserved PLT entry.
7349 gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7350 + this->first_plt_entry_offset());
7351
7352 ++this->count_;
7353
7354 section_offset_type got_offset = this->got_plt_->current_data_size();
7355
7356 // Every PLT entry needs a GOT entry which points back to the PLT
7357 // entry (this will be changed by the dynamic linker, normally
7358 // lazily when the function is called).
7359 this->got_plt_->set_current_data_size(got_offset + 4);
7360
7361 // Every PLT entry needs a reloc.
7362 gsym->set_needs_dynsym_entry();
7363 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7364 got_offset);
7365
7366 // Note that we don't need to save the symbol. The contents of the
7367 // PLT are independent of which symbols are used. The symbols only
7368 // appear in the relocations.
7369 }
7370
7371 template<bool big_endian>
7372 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7373 {
7374 public:
7375 Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7376 : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7377 { }
7378
7379 protected:
7380 // Return the offset of the first non-reserved PLT entry.
7381 virtual unsigned int
7382 do_first_plt_entry_offset() const
7383 { return sizeof(first_plt_entry); }
7384
7385 // Return the size of a PLT entry.
7386 virtual unsigned int
7387 do_get_plt_entry_size() const
7388 { return sizeof(plt_entry); }
7389
7390 virtual void
7391 do_fill_first_plt_entry(unsigned char* pov,
7392 Arm_address got_address,
7393 Arm_address plt_address);
7394
7395 virtual void
7396 do_fill_plt_entry(unsigned char* pov,
7397 Arm_address got_address,
7398 Arm_address plt_address,
7399 unsigned int got_offset,
7400 unsigned int plt_offset);
7401
7402 private:
7403 // Template for the first PLT entry.
7404 static const uint32_t first_plt_entry[5];
7405
7406 // Template for subsequent PLT entries.
7407 static const uint32_t plt_entry[3];
7408 };
7409
7410 // ARM PLTs.
7411 // FIXME: This is not very flexible. Right now this has only been tested
7412 // on armv5te. If we are to support additional architecture features like
7413 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7414
7415 // The first entry in the PLT.
7416 template<bool big_endian>
7417 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7418 {
7419 0xe52de004, // str lr, [sp, #-4]!
7420 0xe59fe004, // ldr lr, [pc, #4]
7421 0xe08fe00e, // add lr, pc, lr
7422 0xe5bef008, // ldr pc, [lr, #8]!
7423 0x00000000, // &GOT[0] - .
7424 };
7425
7426 template<bool big_endian>
7427 void
7428 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7429 unsigned char* pov,
7430 Arm_address got_address,
7431 Arm_address plt_address)
7432 {
7433 // Write first PLT entry. All but the last word are constants.
7434 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7435 / sizeof(plt_entry[0]));
7436 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7437 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7438 // Last word in first PLT entry is &GOT[0] - .
7439 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7440 got_address - (plt_address + 16));
7441 }
7442
7443 // Subsequent entries in the PLT.
7444
7445 template<bool big_endian>
7446 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7447 {
7448 0xe28fc600, // add ip, pc, #0xNN00000
7449 0xe28cca00, // add ip, ip, #0xNN000
7450 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7451 };
7452
7453 template<bool big_endian>
7454 void
7455 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7456 unsigned char* pov,
7457 Arm_address got_address,
7458 Arm_address plt_address,
7459 unsigned int got_offset,
7460 unsigned int plt_offset)
7461 {
7462 int32_t offset = ((got_address + got_offset)
7463 - (plt_address + plt_offset + 8));
7464
7465 gold_assert(offset >= 0 && offset < 0x0fffffff);
7466 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7467 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7468 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7469 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7470 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7471 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7472 }
7473
7474 // Write out the PLT. This uses the hand-coded instructions above,
7475 // and adjusts them as needed. This is all specified by the arm ELF
7476 // Processor Supplement.
7477
7478 template<bool big_endian>
7479 void
7480 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7481 {
7482 const off_t offset = this->offset();
7483 const section_size_type oview_size =
7484 convert_to_section_size_type(this->data_size());
7485 unsigned char* const oview = of->get_output_view(offset, oview_size);
7486
7487 const off_t got_file_offset = this->got_plt_->offset();
7488 const section_size_type got_size =
7489 convert_to_section_size_type(this->got_plt_->data_size());
7490 unsigned char* const got_view = of->get_output_view(got_file_offset,
7491 got_size);
7492 unsigned char* pov = oview;
7493
7494 Arm_address plt_address = this->address();
7495 Arm_address got_address = this->got_plt_->address();
7496
7497 // Write first PLT entry.
7498 this->fill_first_plt_entry(pov, got_address, plt_address);
7499 pov += this->first_plt_entry_offset();
7500
7501 unsigned char* got_pov = got_view;
7502
7503 memset(got_pov, 0, 12);
7504 got_pov += 12;
7505
7506 unsigned int plt_offset = this->first_plt_entry_offset();
7507 unsigned int got_offset = 12;
7508 const unsigned int count = this->count_;
7509 for (unsigned int i = 0;
7510 i < count;
7511 ++i,
7512 pov += this->get_plt_entry_size(),
7513 got_pov += 4,
7514 plt_offset += this->get_plt_entry_size(),
7515 got_offset += 4)
7516 {
7517 // Set and adjust the PLT entry itself.
7518 this->fill_plt_entry(pov, got_address, plt_address,
7519 got_offset, plt_offset);
7520
7521 // Set the entry in the GOT.
7522 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7523 }
7524
7525 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7526 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7527
7528 of->write_output_view(offset, oview_size, oview);
7529 of->write_output_view(got_file_offset, got_size, got_view);
7530 }
7531
7532 // Create a PLT entry for a global symbol.
7533
7534 template<bool big_endian>
7535 void
7536 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7537 Symbol* gsym)
7538 {
7539 if (gsym->has_plt_offset())
7540 return;
7541
7542 if (this->plt_ == NULL)
7543 {
7544 // Create the GOT sections first.
7545 this->got_section(symtab, layout);
7546
7547 this->plt_ = this->make_data_plt(layout, this->got_plt_);
7548
7549 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7550 (elfcpp::SHF_ALLOC
7551 | elfcpp::SHF_EXECINSTR),
7552 this->plt_, ORDER_PLT, false);
7553 }
7554 this->plt_->add_entry(gsym);
7555 }
7556
7557 // Return the number of entries in the PLT.
7558
7559 template<bool big_endian>
7560 unsigned int
7561 Target_arm<big_endian>::plt_entry_count() const
7562 {
7563 if (this->plt_ == NULL)
7564 return 0;
7565 return this->plt_->entry_count();
7566 }
7567
7568 // Return the offset of the first non-reserved PLT entry.
7569
7570 template<bool big_endian>
7571 unsigned int
7572 Target_arm<big_endian>::first_plt_entry_offset() const
7573 {
7574 return this->plt_->first_plt_entry_offset();
7575 }
7576
7577 // Return the size of each PLT entry.
7578
7579 template<bool big_endian>
7580 unsigned int
7581 Target_arm<big_endian>::plt_entry_size() const
7582 {
7583 return this->plt_->get_plt_entry_size();
7584 }
7585
7586 // Get the section to use for TLS_DESC relocations.
7587
7588 template<bool big_endian>
7589 typename Target_arm<big_endian>::Reloc_section*
7590 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7591 {
7592 return this->plt_section()->rel_tls_desc(layout);
7593 }
7594
7595 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7596
7597 template<bool big_endian>
7598 void
7599 Target_arm<big_endian>::define_tls_base_symbol(
7600 Symbol_table* symtab,
7601 Layout* layout)
7602 {
7603 if (this->tls_base_symbol_defined_)
7604 return;
7605
7606 Output_segment* tls_segment = layout->tls_segment();
7607 if (tls_segment != NULL)
7608 {
7609 bool is_exec = parameters->options().output_is_executable();
7610 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7611 Symbol_table::PREDEFINED,
7612 tls_segment, 0, 0,
7613 elfcpp::STT_TLS,
7614 elfcpp::STB_LOCAL,
7615 elfcpp::STV_HIDDEN, 0,
7616 (is_exec
7617 ? Symbol::SEGMENT_END
7618 : Symbol::SEGMENT_START),
7619 true);
7620 }
7621 this->tls_base_symbol_defined_ = true;
7622 }
7623
7624 // Create a GOT entry for the TLS module index.
7625
7626 template<bool big_endian>
7627 unsigned int
7628 Target_arm<big_endian>::got_mod_index_entry(
7629 Symbol_table* symtab,
7630 Layout* layout,
7631 Sized_relobj_file<32, big_endian>* object)
7632 {
7633 if (this->got_mod_index_offset_ == -1U)
7634 {
7635 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7636 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7637 unsigned int got_offset;
7638 if (!parameters->doing_static_link())
7639 {
7640 got_offset = got->add_constant(0);
7641 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7642 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7643 got_offset);
7644 }
7645 else
7646 {
7647 // We are doing a static link. Just mark it as belong to module 1,
7648 // the executable.
7649 got_offset = got->add_constant(1);
7650 }
7651
7652 got->add_constant(0);
7653 this->got_mod_index_offset_ = got_offset;
7654 }
7655 return this->got_mod_index_offset_;
7656 }
7657
7658 // Optimize the TLS relocation type based on what we know about the
7659 // symbol. IS_FINAL is true if the final address of this symbol is
7660 // known at link time.
7661
7662 template<bool big_endian>
7663 tls::Tls_optimization
7664 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7665 {
7666 // FIXME: Currently we do not do any TLS optimization.
7667 return tls::TLSOPT_NONE;
7668 }
7669
7670 // Get the Reference_flags for a particular relocation.
7671
7672 template<bool big_endian>
7673 int
7674 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7675 {
7676 switch (r_type)
7677 {
7678 case elfcpp::R_ARM_NONE:
7679 case elfcpp::R_ARM_V4BX:
7680 case elfcpp::R_ARM_GNU_VTENTRY:
7681 case elfcpp::R_ARM_GNU_VTINHERIT:
7682 // No symbol reference.
7683 return 0;
7684
7685 case elfcpp::R_ARM_ABS32:
7686 case elfcpp::R_ARM_ABS16:
7687 case elfcpp::R_ARM_ABS12:
7688 case elfcpp::R_ARM_THM_ABS5:
7689 case elfcpp::R_ARM_ABS8:
7690 case elfcpp::R_ARM_BASE_ABS:
7691 case elfcpp::R_ARM_MOVW_ABS_NC:
7692 case elfcpp::R_ARM_MOVT_ABS:
7693 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7694 case elfcpp::R_ARM_THM_MOVT_ABS:
7695 case elfcpp::R_ARM_ABS32_NOI:
7696 return Symbol::ABSOLUTE_REF;
7697
7698 case elfcpp::R_ARM_REL32:
7699 case elfcpp::R_ARM_LDR_PC_G0:
7700 case elfcpp::R_ARM_SBREL32:
7701 case elfcpp::R_ARM_THM_PC8:
7702 case elfcpp::R_ARM_BASE_PREL:
7703 case elfcpp::R_ARM_MOVW_PREL_NC:
7704 case elfcpp::R_ARM_MOVT_PREL:
7705 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7706 case elfcpp::R_ARM_THM_MOVT_PREL:
7707 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7708 case elfcpp::R_ARM_THM_PC12:
7709 case elfcpp::R_ARM_REL32_NOI:
7710 case elfcpp::R_ARM_ALU_PC_G0_NC:
7711 case elfcpp::R_ARM_ALU_PC_G0:
7712 case elfcpp::R_ARM_ALU_PC_G1_NC:
7713 case elfcpp::R_ARM_ALU_PC_G1:
7714 case elfcpp::R_ARM_ALU_PC_G2:
7715 case elfcpp::R_ARM_LDR_PC_G1:
7716 case elfcpp::R_ARM_LDR_PC_G2:
7717 case elfcpp::R_ARM_LDRS_PC_G0:
7718 case elfcpp::R_ARM_LDRS_PC_G1:
7719 case elfcpp::R_ARM_LDRS_PC_G2:
7720 case elfcpp::R_ARM_LDC_PC_G0:
7721 case elfcpp::R_ARM_LDC_PC_G1:
7722 case elfcpp::R_ARM_LDC_PC_G2:
7723 case elfcpp::R_ARM_ALU_SB_G0_NC:
7724 case elfcpp::R_ARM_ALU_SB_G0:
7725 case elfcpp::R_ARM_ALU_SB_G1_NC:
7726 case elfcpp::R_ARM_ALU_SB_G1:
7727 case elfcpp::R_ARM_ALU_SB_G2:
7728 case elfcpp::R_ARM_LDR_SB_G0:
7729 case elfcpp::R_ARM_LDR_SB_G1:
7730 case elfcpp::R_ARM_LDR_SB_G2:
7731 case elfcpp::R_ARM_LDRS_SB_G0:
7732 case elfcpp::R_ARM_LDRS_SB_G1:
7733 case elfcpp::R_ARM_LDRS_SB_G2:
7734 case elfcpp::R_ARM_LDC_SB_G0:
7735 case elfcpp::R_ARM_LDC_SB_G1:
7736 case elfcpp::R_ARM_LDC_SB_G2:
7737 case elfcpp::R_ARM_MOVW_BREL_NC:
7738 case elfcpp::R_ARM_MOVT_BREL:
7739 case elfcpp::R_ARM_MOVW_BREL:
7740 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7741 case elfcpp::R_ARM_THM_MOVT_BREL:
7742 case elfcpp::R_ARM_THM_MOVW_BREL:
7743 case elfcpp::R_ARM_GOTOFF32:
7744 case elfcpp::R_ARM_GOTOFF12:
7745 case elfcpp::R_ARM_SBREL31:
7746 return Symbol::RELATIVE_REF;
7747
7748 case elfcpp::R_ARM_PLT32:
7749 case elfcpp::R_ARM_CALL:
7750 case elfcpp::R_ARM_JUMP24:
7751 case elfcpp::R_ARM_THM_CALL:
7752 case elfcpp::R_ARM_THM_JUMP24:
7753 case elfcpp::R_ARM_THM_JUMP19:
7754 case elfcpp::R_ARM_THM_JUMP6:
7755 case elfcpp::R_ARM_THM_JUMP11:
7756 case elfcpp::R_ARM_THM_JUMP8:
7757 // R_ARM_PREL31 is not used to relocate call/jump instructions but
7758 // in unwind tables. It may point to functions via PLTs.
7759 // So we treat it like call/jump relocations above.
7760 case elfcpp::R_ARM_PREL31:
7761 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7762
7763 case elfcpp::R_ARM_GOT_BREL:
7764 case elfcpp::R_ARM_GOT_ABS:
7765 case elfcpp::R_ARM_GOT_PREL:
7766 // Absolute in GOT.
7767 return Symbol::ABSOLUTE_REF;
7768
7769 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7770 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7771 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7772 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7773 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7774 return Symbol::TLS_REF;
7775
7776 case elfcpp::R_ARM_TARGET1:
7777 case elfcpp::R_ARM_TARGET2:
7778 case elfcpp::R_ARM_COPY:
7779 case elfcpp::R_ARM_GLOB_DAT:
7780 case elfcpp::R_ARM_JUMP_SLOT:
7781 case elfcpp::R_ARM_RELATIVE:
7782 case elfcpp::R_ARM_PC24:
7783 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7784 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7785 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7786 default:
7787 // Not expected. We will give an error later.
7788 return 0;
7789 }
7790 }
7791
7792 // Report an unsupported relocation against a local symbol.
7793
7794 template<bool big_endian>
7795 void
7796 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7797 Sized_relobj_file<32, big_endian>* object,
7798 unsigned int r_type)
7799 {
7800 gold_error(_("%s: unsupported reloc %u against local symbol"),
7801 object->name().c_str(), r_type);
7802 }
7803
7804 // We are about to emit a dynamic relocation of type R_TYPE. If the
7805 // dynamic linker does not support it, issue an error. The GNU linker
7806 // only issues a non-PIC error for an allocated read-only section.
7807 // Here we know the section is allocated, but we don't know that it is
7808 // read-only. But we check for all the relocation types which the
7809 // glibc dynamic linker supports, so it seems appropriate to issue an
7810 // error even if the section is not read-only.
7811
7812 template<bool big_endian>
7813 void
7814 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7815 unsigned int r_type)
7816 {
7817 switch (r_type)
7818 {
7819 // These are the relocation types supported by glibc for ARM.
7820 case elfcpp::R_ARM_RELATIVE:
7821 case elfcpp::R_ARM_COPY:
7822 case elfcpp::R_ARM_GLOB_DAT:
7823 case elfcpp::R_ARM_JUMP_SLOT:
7824 case elfcpp::R_ARM_ABS32:
7825 case elfcpp::R_ARM_ABS32_NOI:
7826 case elfcpp::R_ARM_PC24:
7827 // FIXME: The following 3 types are not supported by Android's dynamic
7828 // linker.
7829 case elfcpp::R_ARM_TLS_DTPMOD32:
7830 case elfcpp::R_ARM_TLS_DTPOFF32:
7831 case elfcpp::R_ARM_TLS_TPOFF32:
7832 return;
7833
7834 default:
7835 {
7836 // This prevents us from issuing more than one error per reloc
7837 // section. But we can still wind up issuing more than one
7838 // error per object file.
7839 if (this->issued_non_pic_error_)
7840 return;
7841 const Arm_reloc_property* reloc_property =
7842 arm_reloc_property_table->get_reloc_property(r_type);
7843 gold_assert(reloc_property != NULL);
7844 object->error(_("requires unsupported dynamic reloc %s; "
7845 "recompile with -fPIC"),
7846 reloc_property->name().c_str());
7847 this->issued_non_pic_error_ = true;
7848 return;
7849 }
7850
7851 case elfcpp::R_ARM_NONE:
7852 gold_unreachable();
7853 }
7854 }
7855
7856 // Scan a relocation for a local symbol.
7857 // FIXME: This only handles a subset of relocation types used by Android
7858 // on ARM v5te devices.
7859
7860 template<bool big_endian>
7861 inline void
7862 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7863 Layout* layout,
7864 Target_arm* target,
7865 Sized_relobj_file<32, big_endian>* object,
7866 unsigned int data_shndx,
7867 Output_section* output_section,
7868 const elfcpp::Rel<32, big_endian>& reloc,
7869 unsigned int r_type,
7870 const elfcpp::Sym<32, big_endian>& lsym,
7871 bool is_discarded)
7872 {
7873 if (is_discarded)
7874 return;
7875
7876 r_type = get_real_reloc_type(r_type);
7877 switch (r_type)
7878 {
7879 case elfcpp::R_ARM_NONE:
7880 case elfcpp::R_ARM_V4BX:
7881 case elfcpp::R_ARM_GNU_VTENTRY:
7882 case elfcpp::R_ARM_GNU_VTINHERIT:
7883 break;
7884
7885 case elfcpp::R_ARM_ABS32:
7886 case elfcpp::R_ARM_ABS32_NOI:
7887 // If building a shared library (or a position-independent
7888 // executable), we need to create a dynamic relocation for
7889 // this location. The relocation applied at link time will
7890 // apply the link-time value, so we flag the location with
7891 // an R_ARM_RELATIVE relocation so the dynamic loader can
7892 // relocate it easily.
7893 if (parameters->options().output_is_position_independent())
7894 {
7895 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7896 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7897 // If we are to add more other reloc types than R_ARM_ABS32,
7898 // we need to add check_non_pic(object, r_type) here.
7899 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7900 output_section, data_shndx,
7901 reloc.get_r_offset());
7902 }
7903 break;
7904
7905 case elfcpp::R_ARM_ABS16:
7906 case elfcpp::R_ARM_ABS12:
7907 case elfcpp::R_ARM_THM_ABS5:
7908 case elfcpp::R_ARM_ABS8:
7909 case elfcpp::R_ARM_BASE_ABS:
7910 case elfcpp::R_ARM_MOVW_ABS_NC:
7911 case elfcpp::R_ARM_MOVT_ABS:
7912 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7913 case elfcpp::R_ARM_THM_MOVT_ABS:
7914 // If building a shared library (or a position-independent
7915 // executable), we need to create a dynamic relocation for
7916 // this location. Because the addend needs to remain in the
7917 // data section, we need to be careful not to apply this
7918 // relocation statically.
7919 if (parameters->options().output_is_position_independent())
7920 {
7921 check_non_pic(object, r_type);
7922 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7923 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7924 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7925 rel_dyn->add_local(object, r_sym, r_type, output_section,
7926 data_shndx, reloc.get_r_offset());
7927 else
7928 {
7929 gold_assert(lsym.get_st_value() == 0);
7930 unsigned int shndx = lsym.get_st_shndx();
7931 bool is_ordinary;
7932 shndx = object->adjust_sym_shndx(r_sym, shndx,
7933 &is_ordinary);
7934 if (!is_ordinary)
7935 object->error(_("section symbol %u has bad shndx %u"),
7936 r_sym, shndx);
7937 else
7938 rel_dyn->add_local_section(object, shndx,
7939 r_type, output_section,
7940 data_shndx, reloc.get_r_offset());
7941 }
7942 }
7943 break;
7944
7945 case elfcpp::R_ARM_REL32:
7946 case elfcpp::R_ARM_LDR_PC_G0:
7947 case elfcpp::R_ARM_SBREL32:
7948 case elfcpp::R_ARM_THM_CALL:
7949 case elfcpp::R_ARM_THM_PC8:
7950 case elfcpp::R_ARM_BASE_PREL:
7951 case elfcpp::R_ARM_PLT32:
7952 case elfcpp::R_ARM_CALL:
7953 case elfcpp::R_ARM_JUMP24:
7954 case elfcpp::R_ARM_THM_JUMP24:
7955 case elfcpp::R_ARM_SBREL31:
7956 case elfcpp::R_ARM_PREL31:
7957 case elfcpp::R_ARM_MOVW_PREL_NC:
7958 case elfcpp::R_ARM_MOVT_PREL:
7959 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7960 case elfcpp::R_ARM_THM_MOVT_PREL:
7961 case elfcpp::R_ARM_THM_JUMP19:
7962 case elfcpp::R_ARM_THM_JUMP6:
7963 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7964 case elfcpp::R_ARM_THM_PC12:
7965 case elfcpp::R_ARM_REL32_NOI:
7966 case elfcpp::R_ARM_ALU_PC_G0_NC:
7967 case elfcpp::R_ARM_ALU_PC_G0:
7968 case elfcpp::R_ARM_ALU_PC_G1_NC:
7969 case elfcpp::R_ARM_ALU_PC_G1:
7970 case elfcpp::R_ARM_ALU_PC_G2:
7971 case elfcpp::R_ARM_LDR_PC_G1:
7972 case elfcpp::R_ARM_LDR_PC_G2:
7973 case elfcpp::R_ARM_LDRS_PC_G0:
7974 case elfcpp::R_ARM_LDRS_PC_G1:
7975 case elfcpp::R_ARM_LDRS_PC_G2:
7976 case elfcpp::R_ARM_LDC_PC_G0:
7977 case elfcpp::R_ARM_LDC_PC_G1:
7978 case elfcpp::R_ARM_LDC_PC_G2:
7979 case elfcpp::R_ARM_ALU_SB_G0_NC:
7980 case elfcpp::R_ARM_ALU_SB_G0:
7981 case elfcpp::R_ARM_ALU_SB_G1_NC:
7982 case elfcpp::R_ARM_ALU_SB_G1:
7983 case elfcpp::R_ARM_ALU_SB_G2:
7984 case elfcpp::R_ARM_LDR_SB_G0:
7985 case elfcpp::R_ARM_LDR_SB_G1:
7986 case elfcpp::R_ARM_LDR_SB_G2:
7987 case elfcpp::R_ARM_LDRS_SB_G0:
7988 case elfcpp::R_ARM_LDRS_SB_G1:
7989 case elfcpp::R_ARM_LDRS_SB_G2:
7990 case elfcpp::R_ARM_LDC_SB_G0:
7991 case elfcpp::R_ARM_LDC_SB_G1:
7992 case elfcpp::R_ARM_LDC_SB_G2:
7993 case elfcpp::R_ARM_MOVW_BREL_NC:
7994 case elfcpp::R_ARM_MOVT_BREL:
7995 case elfcpp::R_ARM_MOVW_BREL:
7996 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7997 case elfcpp::R_ARM_THM_MOVT_BREL:
7998 case elfcpp::R_ARM_THM_MOVW_BREL:
7999 case elfcpp::R_ARM_THM_JUMP11:
8000 case elfcpp::R_ARM_THM_JUMP8:
8001 // We don't need to do anything for a relative addressing relocation
8002 // against a local symbol if it does not reference the GOT.
8003 break;
8004
8005 case elfcpp::R_ARM_GOTOFF32:
8006 case elfcpp::R_ARM_GOTOFF12:
8007 // We need a GOT section:
8008 target->got_section(symtab, layout);
8009 break;
8010
8011 case elfcpp::R_ARM_GOT_BREL:
8012 case elfcpp::R_ARM_GOT_PREL:
8013 {
8014 // The symbol requires a GOT entry.
8015 Arm_output_data_got<big_endian>* got =
8016 target->got_section(symtab, layout);
8017 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8018 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8019 {
8020 // If we are generating a shared object, we need to add a
8021 // dynamic RELATIVE relocation for this symbol's GOT entry.
8022 if (parameters->options().output_is_position_independent())
8023 {
8024 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8025 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8026 rel_dyn->add_local_relative(
8027 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8028 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8029 }
8030 }
8031 }
8032 break;
8033
8034 case elfcpp::R_ARM_TARGET1:
8035 case elfcpp::R_ARM_TARGET2:
8036 // This should have been mapped to another type already.
8037 // Fall through.
8038 case elfcpp::R_ARM_COPY:
8039 case elfcpp::R_ARM_GLOB_DAT:
8040 case elfcpp::R_ARM_JUMP_SLOT:
8041 case elfcpp::R_ARM_RELATIVE:
8042 // These are relocations which should only be seen by the
8043 // dynamic linker, and should never be seen here.
8044 gold_error(_("%s: unexpected reloc %u in object file"),
8045 object->name().c_str(), r_type);
8046 break;
8047
8048
8049 // These are initial TLS relocs, which are expected when
8050 // linking.
8051 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8052 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8053 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8054 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8055 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8056 {
8057 bool output_is_shared = parameters->options().shared();
8058 const tls::Tls_optimization optimized_type
8059 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8060 r_type);
8061 switch (r_type)
8062 {
8063 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8064 if (optimized_type == tls::TLSOPT_NONE)
8065 {
8066 // Create a pair of GOT entries for the module index and
8067 // dtv-relative offset.
8068 Arm_output_data_got<big_endian>* got
8069 = target->got_section(symtab, layout);
8070 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8071 unsigned int shndx = lsym.get_st_shndx();
8072 bool is_ordinary;
8073 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8074 if (!is_ordinary)
8075 {
8076 object->error(_("local symbol %u has bad shndx %u"),
8077 r_sym, shndx);
8078 break;
8079 }
8080
8081 if (!parameters->doing_static_link())
8082 got->add_local_pair_with_rel(object, r_sym, shndx,
8083 GOT_TYPE_TLS_PAIR,
8084 target->rel_dyn_section(layout),
8085 elfcpp::R_ARM_TLS_DTPMOD32);
8086 else
8087 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8088 object, r_sym);
8089 }
8090 else
8091 // FIXME: TLS optimization not supported yet.
8092 gold_unreachable();
8093 break;
8094
8095 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8096 if (optimized_type == tls::TLSOPT_NONE)
8097 {
8098 // Create a GOT entry for the module index.
8099 target->got_mod_index_entry(symtab, layout, object);
8100 }
8101 else
8102 // FIXME: TLS optimization not supported yet.
8103 gold_unreachable();
8104 break;
8105
8106 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8107 break;
8108
8109 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8110 layout->set_has_static_tls();
8111 if (optimized_type == tls::TLSOPT_NONE)
8112 {
8113 // Create a GOT entry for the tp-relative offset.
8114 Arm_output_data_got<big_endian>* got
8115 = target->got_section(symtab, layout);
8116 unsigned int r_sym =
8117 elfcpp::elf_r_sym<32>(reloc.get_r_info());
8118 if (!parameters->doing_static_link())
8119 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8120 target->rel_dyn_section(layout),
8121 elfcpp::R_ARM_TLS_TPOFF32);
8122 else if (!object->local_has_got_offset(r_sym,
8123 GOT_TYPE_TLS_OFFSET))
8124 {
8125 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8126 unsigned int got_offset =
8127 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8128 got->add_static_reloc(got_offset,
8129 elfcpp::R_ARM_TLS_TPOFF32, object,
8130 r_sym);
8131 }
8132 }
8133 else
8134 // FIXME: TLS optimization not supported yet.
8135 gold_unreachable();
8136 break;
8137
8138 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8139 layout->set_has_static_tls();
8140 if (output_is_shared)
8141 {
8142 // We need to create a dynamic relocation.
8143 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8144 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8145 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8146 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8147 output_section, data_shndx,
8148 reloc.get_r_offset());
8149 }
8150 break;
8151
8152 default:
8153 gold_unreachable();
8154 }
8155 }
8156 break;
8157
8158 case elfcpp::R_ARM_PC24:
8159 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8160 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8161 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8162 default:
8163 unsupported_reloc_local(object, r_type);
8164 break;
8165 }
8166 }
8167
8168 // Report an unsupported relocation against a global symbol.
8169
8170 template<bool big_endian>
8171 void
8172 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8173 Sized_relobj_file<32, big_endian>* object,
8174 unsigned int r_type,
8175 Symbol* gsym)
8176 {
8177 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8178 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8179 }
8180
8181 template<bool big_endian>
8182 inline bool
8183 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8184 unsigned int r_type)
8185 {
8186 switch (r_type)
8187 {
8188 case elfcpp::R_ARM_PC24:
8189 case elfcpp::R_ARM_THM_CALL:
8190 case elfcpp::R_ARM_PLT32:
8191 case elfcpp::R_ARM_CALL:
8192 case elfcpp::R_ARM_JUMP24:
8193 case elfcpp::R_ARM_THM_JUMP24:
8194 case elfcpp::R_ARM_SBREL31:
8195 case elfcpp::R_ARM_PREL31:
8196 case elfcpp::R_ARM_THM_JUMP19:
8197 case elfcpp::R_ARM_THM_JUMP6:
8198 case elfcpp::R_ARM_THM_JUMP11:
8199 case elfcpp::R_ARM_THM_JUMP8:
8200 // All the relocations above are branches except SBREL31 and PREL31.
8201 return false;
8202
8203 default:
8204 // Be conservative and assume this is a function pointer.
8205 return true;
8206 }
8207 }
8208
8209 template<bool big_endian>
8210 inline bool
8211 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8212 Symbol_table*,
8213 Layout*,
8214 Target_arm<big_endian>* target,
8215 Sized_relobj_file<32, big_endian>*,
8216 unsigned int,
8217 Output_section*,
8218 const elfcpp::Rel<32, big_endian>&,
8219 unsigned int r_type,
8220 const elfcpp::Sym<32, big_endian>&)
8221 {
8222 r_type = target->get_real_reloc_type(r_type);
8223 return possible_function_pointer_reloc(r_type);
8224 }
8225
8226 template<bool big_endian>
8227 inline bool
8228 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8229 Symbol_table*,
8230 Layout*,
8231 Target_arm<big_endian>* target,
8232 Sized_relobj_file<32, big_endian>*,
8233 unsigned int,
8234 Output_section*,
8235 const elfcpp::Rel<32, big_endian>&,
8236 unsigned int r_type,
8237 Symbol* gsym)
8238 {
8239 // GOT is not a function.
8240 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8241 return false;
8242
8243 r_type = target->get_real_reloc_type(r_type);
8244 return possible_function_pointer_reloc(r_type);
8245 }
8246
8247 // Scan a relocation for a global symbol.
8248
8249 template<bool big_endian>
8250 inline void
8251 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8252 Layout* layout,
8253 Target_arm* target,
8254 Sized_relobj_file<32, big_endian>* object,
8255 unsigned int data_shndx,
8256 Output_section* output_section,
8257 const elfcpp::Rel<32, big_endian>& reloc,
8258 unsigned int r_type,
8259 Symbol* gsym)
8260 {
8261 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8262 // section. We check here to avoid creating a dynamic reloc against
8263 // _GLOBAL_OFFSET_TABLE_.
8264 if (!target->has_got_section()
8265 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8266 target->got_section(symtab, layout);
8267
8268 r_type = get_real_reloc_type(r_type);
8269 switch (r_type)
8270 {
8271 case elfcpp::R_ARM_NONE:
8272 case elfcpp::R_ARM_V4BX:
8273 case elfcpp::R_ARM_GNU_VTENTRY:
8274 case elfcpp::R_ARM_GNU_VTINHERIT:
8275 break;
8276
8277 case elfcpp::R_ARM_ABS32:
8278 case elfcpp::R_ARM_ABS16:
8279 case elfcpp::R_ARM_ABS12:
8280 case elfcpp::R_ARM_THM_ABS5:
8281 case elfcpp::R_ARM_ABS8:
8282 case elfcpp::R_ARM_BASE_ABS:
8283 case elfcpp::R_ARM_MOVW_ABS_NC:
8284 case elfcpp::R_ARM_MOVT_ABS:
8285 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8286 case elfcpp::R_ARM_THM_MOVT_ABS:
8287 case elfcpp::R_ARM_ABS32_NOI:
8288 // Absolute addressing relocations.
8289 {
8290 // Make a PLT entry if necessary.
8291 if (this->symbol_needs_plt_entry(gsym))
8292 {
8293 target->make_plt_entry(symtab, layout, gsym);
8294 // Since this is not a PC-relative relocation, we may be
8295 // taking the address of a function. In that case we need to
8296 // set the entry in the dynamic symbol table to the address of
8297 // the PLT entry.
8298 if (gsym->is_from_dynobj() && !parameters->options().shared())
8299 gsym->set_needs_dynsym_value();
8300 }
8301 // Make a dynamic relocation if necessary.
8302 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8303 {
8304 if (!parameters->options().output_is_position_independent()
8305 && gsym->may_need_copy_reloc())
8306 {
8307 target->copy_reloc(symtab, layout, object,
8308 data_shndx, output_section, gsym, reloc);
8309 }
8310 else if ((r_type == elfcpp::R_ARM_ABS32
8311 || r_type == elfcpp::R_ARM_ABS32_NOI)
8312 && gsym->can_use_relative_reloc(false))
8313 {
8314 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8315 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8316 output_section, object,
8317 data_shndx, reloc.get_r_offset());
8318 }
8319 else
8320 {
8321 check_non_pic(object, r_type);
8322 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8323 rel_dyn->add_global(gsym, r_type, output_section, object,
8324 data_shndx, reloc.get_r_offset());
8325 }
8326 }
8327 }
8328 break;
8329
8330 case elfcpp::R_ARM_GOTOFF32:
8331 case elfcpp::R_ARM_GOTOFF12:
8332 // We need a GOT section.
8333 target->got_section(symtab, layout);
8334 break;
8335
8336 case elfcpp::R_ARM_REL32:
8337 case elfcpp::R_ARM_LDR_PC_G0:
8338 case elfcpp::R_ARM_SBREL32:
8339 case elfcpp::R_ARM_THM_PC8:
8340 case elfcpp::R_ARM_BASE_PREL:
8341 case elfcpp::R_ARM_MOVW_PREL_NC:
8342 case elfcpp::R_ARM_MOVT_PREL:
8343 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8344 case elfcpp::R_ARM_THM_MOVT_PREL:
8345 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8346 case elfcpp::R_ARM_THM_PC12:
8347 case elfcpp::R_ARM_REL32_NOI:
8348 case elfcpp::R_ARM_ALU_PC_G0_NC:
8349 case elfcpp::R_ARM_ALU_PC_G0:
8350 case elfcpp::R_ARM_ALU_PC_G1_NC:
8351 case elfcpp::R_ARM_ALU_PC_G1:
8352 case elfcpp::R_ARM_ALU_PC_G2:
8353 case elfcpp::R_ARM_LDR_PC_G1:
8354 case elfcpp::R_ARM_LDR_PC_G2:
8355 case elfcpp::R_ARM_LDRS_PC_G0:
8356 case elfcpp::R_ARM_LDRS_PC_G1:
8357 case elfcpp::R_ARM_LDRS_PC_G2:
8358 case elfcpp::R_ARM_LDC_PC_G0:
8359 case elfcpp::R_ARM_LDC_PC_G1:
8360 case elfcpp::R_ARM_LDC_PC_G2:
8361 case elfcpp::R_ARM_ALU_SB_G0_NC:
8362 case elfcpp::R_ARM_ALU_SB_G0:
8363 case elfcpp::R_ARM_ALU_SB_G1_NC:
8364 case elfcpp::R_ARM_ALU_SB_G1:
8365 case elfcpp::R_ARM_ALU_SB_G2:
8366 case elfcpp::R_ARM_LDR_SB_G0:
8367 case elfcpp::R_ARM_LDR_SB_G1:
8368 case elfcpp::R_ARM_LDR_SB_G2:
8369 case elfcpp::R_ARM_LDRS_SB_G0:
8370 case elfcpp::R_ARM_LDRS_SB_G1:
8371 case elfcpp::R_ARM_LDRS_SB_G2:
8372 case elfcpp::R_ARM_LDC_SB_G0:
8373 case elfcpp::R_ARM_LDC_SB_G1:
8374 case elfcpp::R_ARM_LDC_SB_G2:
8375 case elfcpp::R_ARM_MOVW_BREL_NC:
8376 case elfcpp::R_ARM_MOVT_BREL:
8377 case elfcpp::R_ARM_MOVW_BREL:
8378 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8379 case elfcpp::R_ARM_THM_MOVT_BREL:
8380 case elfcpp::R_ARM_THM_MOVW_BREL:
8381 // Relative addressing relocations.
8382 {
8383 // Make a dynamic relocation if necessary.
8384 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8385 {
8386 if (parameters->options().output_is_executable()
8387 && target->may_need_copy_reloc(gsym))
8388 {
8389 target->copy_reloc(symtab, layout, object,
8390 data_shndx, output_section, gsym, reloc);
8391 }
8392 else
8393 {
8394 check_non_pic(object, r_type);
8395 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8396 rel_dyn->add_global(gsym, r_type, output_section, object,
8397 data_shndx, reloc.get_r_offset());
8398 }
8399 }
8400 }
8401 break;
8402
8403 case elfcpp::R_ARM_THM_CALL:
8404 case elfcpp::R_ARM_PLT32:
8405 case elfcpp::R_ARM_CALL:
8406 case elfcpp::R_ARM_JUMP24:
8407 case elfcpp::R_ARM_THM_JUMP24:
8408 case elfcpp::R_ARM_SBREL31:
8409 case elfcpp::R_ARM_PREL31:
8410 case elfcpp::R_ARM_THM_JUMP19:
8411 case elfcpp::R_ARM_THM_JUMP6:
8412 case elfcpp::R_ARM_THM_JUMP11:
8413 case elfcpp::R_ARM_THM_JUMP8:
8414 // All the relocation above are branches except for the PREL31 ones.
8415 // A PREL31 relocation can point to a personality function in a shared
8416 // library. In that case we want to use a PLT because we want to
8417 // call the personality routine and the dynamic linkers we care about
8418 // do not support dynamic PREL31 relocations. An REL31 relocation may
8419 // point to a function whose unwinding behaviour is being described but
8420 // we will not mistakenly generate a PLT for that because we should use
8421 // a local section symbol.
8422
8423 // If the symbol is fully resolved, this is just a relative
8424 // local reloc. Otherwise we need a PLT entry.
8425 if (gsym->final_value_is_known())
8426 break;
8427 // If building a shared library, we can also skip the PLT entry
8428 // if the symbol is defined in the output file and is protected
8429 // or hidden.
8430 if (gsym->is_defined()
8431 && !gsym->is_from_dynobj()
8432 && !gsym->is_preemptible())
8433 break;
8434 target->make_plt_entry(symtab, layout, gsym);
8435 break;
8436
8437 case elfcpp::R_ARM_GOT_BREL:
8438 case elfcpp::R_ARM_GOT_ABS:
8439 case elfcpp::R_ARM_GOT_PREL:
8440 {
8441 // The symbol requires a GOT entry.
8442 Arm_output_data_got<big_endian>* got =
8443 target->got_section(symtab, layout);
8444 if (gsym->final_value_is_known())
8445 got->add_global(gsym, GOT_TYPE_STANDARD);
8446 else
8447 {
8448 // If this symbol is not fully resolved, we need to add a
8449 // GOT entry with a dynamic relocation.
8450 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8451 if (gsym->is_from_dynobj()
8452 || gsym->is_undefined()
8453 || gsym->is_preemptible()
8454 || (gsym->visibility() == elfcpp::STV_PROTECTED
8455 && parameters->options().shared()))
8456 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8457 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8458 else
8459 {
8460 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8461 rel_dyn->add_global_relative(
8462 gsym, elfcpp::R_ARM_RELATIVE, got,
8463 gsym->got_offset(GOT_TYPE_STANDARD));
8464 }
8465 }
8466 }
8467 break;
8468
8469 case elfcpp::R_ARM_TARGET1:
8470 case elfcpp::R_ARM_TARGET2:
8471 // These should have been mapped to other types already.
8472 // Fall through.
8473 case elfcpp::R_ARM_COPY:
8474 case elfcpp::R_ARM_GLOB_DAT:
8475 case elfcpp::R_ARM_JUMP_SLOT:
8476 case elfcpp::R_ARM_RELATIVE:
8477 // These are relocations which should only be seen by the
8478 // dynamic linker, and should never be seen here.
8479 gold_error(_("%s: unexpected reloc %u in object file"),
8480 object->name().c_str(), r_type);
8481 break;
8482
8483 // These are initial tls relocs, which are expected when
8484 // linking.
8485 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8486 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8487 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8488 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8489 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8490 {
8491 const bool is_final = gsym->final_value_is_known();
8492 const tls::Tls_optimization optimized_type
8493 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8494 switch (r_type)
8495 {
8496 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8497 if (optimized_type == tls::TLSOPT_NONE)
8498 {
8499 // Create a pair of GOT entries for the module index and
8500 // dtv-relative offset.
8501 Arm_output_data_got<big_endian>* got
8502 = target->got_section(symtab, layout);
8503 if (!parameters->doing_static_link())
8504 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8505 target->rel_dyn_section(layout),
8506 elfcpp::R_ARM_TLS_DTPMOD32,
8507 elfcpp::R_ARM_TLS_DTPOFF32);
8508 else
8509 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8510 }
8511 else
8512 // FIXME: TLS optimization not supported yet.
8513 gold_unreachable();
8514 break;
8515
8516 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8517 if (optimized_type == tls::TLSOPT_NONE)
8518 {
8519 // Create a GOT entry for the module index.
8520 target->got_mod_index_entry(symtab, layout, object);
8521 }
8522 else
8523 // FIXME: TLS optimization not supported yet.
8524 gold_unreachable();
8525 break;
8526
8527 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8528 break;
8529
8530 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8531 layout->set_has_static_tls();
8532 if (optimized_type == tls::TLSOPT_NONE)
8533 {
8534 // Create a GOT entry for the tp-relative offset.
8535 Arm_output_data_got<big_endian>* got
8536 = target->got_section(symtab, layout);
8537 if (!parameters->doing_static_link())
8538 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8539 target->rel_dyn_section(layout),
8540 elfcpp::R_ARM_TLS_TPOFF32);
8541 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8542 {
8543 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8544 unsigned int got_offset =
8545 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8546 got->add_static_reloc(got_offset,
8547 elfcpp::R_ARM_TLS_TPOFF32, gsym);
8548 }
8549 }
8550 else
8551 // FIXME: TLS optimization not supported yet.
8552 gold_unreachable();
8553 break;
8554
8555 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8556 layout->set_has_static_tls();
8557 if (parameters->options().shared())
8558 {
8559 // We need to create a dynamic relocation.
8560 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8561 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8562 output_section, object,
8563 data_shndx, reloc.get_r_offset());
8564 }
8565 break;
8566
8567 default:
8568 gold_unreachable();
8569 }
8570 }
8571 break;
8572
8573 case elfcpp::R_ARM_PC24:
8574 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8575 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8576 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8577 default:
8578 unsupported_reloc_global(object, r_type, gsym);
8579 break;
8580 }
8581 }
8582
8583 // Process relocations for gc.
8584
8585 template<bool big_endian>
8586 void
8587 Target_arm<big_endian>::gc_process_relocs(
8588 Symbol_table* symtab,
8589 Layout* layout,
8590 Sized_relobj_file<32, big_endian>* object,
8591 unsigned int data_shndx,
8592 unsigned int,
8593 const unsigned char* prelocs,
8594 size_t reloc_count,
8595 Output_section* output_section,
8596 bool needs_special_offset_handling,
8597 size_t local_symbol_count,
8598 const unsigned char* plocal_symbols)
8599 {
8600 typedef Target_arm<big_endian> Arm;
8601 typedef typename Target_arm<big_endian>::Scan Scan;
8602
8603 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8604 typename Target_arm::Relocatable_size_for_reloc>(
8605 symtab,
8606 layout,
8607 this,
8608 object,
8609 data_shndx,
8610 prelocs,
8611 reloc_count,
8612 output_section,
8613 needs_special_offset_handling,
8614 local_symbol_count,
8615 plocal_symbols);
8616 }
8617
8618 // Scan relocations for a section.
8619
8620 template<bool big_endian>
8621 void
8622 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8623 Layout* layout,
8624 Sized_relobj_file<32, big_endian>* object,
8625 unsigned int data_shndx,
8626 unsigned int sh_type,
8627 const unsigned char* prelocs,
8628 size_t reloc_count,
8629 Output_section* output_section,
8630 bool needs_special_offset_handling,
8631 size_t local_symbol_count,
8632 const unsigned char* plocal_symbols)
8633 {
8634 typedef typename Target_arm<big_endian>::Scan Scan;
8635 if (sh_type == elfcpp::SHT_RELA)
8636 {
8637 gold_error(_("%s: unsupported RELA reloc section"),
8638 object->name().c_str());
8639 return;
8640 }
8641
8642 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8643 symtab,
8644 layout,
8645 this,
8646 object,
8647 data_shndx,
8648 prelocs,
8649 reloc_count,
8650 output_section,
8651 needs_special_offset_handling,
8652 local_symbol_count,
8653 plocal_symbols);
8654 }
8655
8656 // Finalize the sections.
8657
8658 template<bool big_endian>
8659 void
8660 Target_arm<big_endian>::do_finalize_sections(
8661 Layout* layout,
8662 const Input_objects* input_objects,
8663 Symbol_table*)
8664 {
8665 bool merged_any_attributes = false;
8666 // Merge processor-specific flags.
8667 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8668 p != input_objects->relobj_end();
8669 ++p)
8670 {
8671 Arm_relobj<big_endian>* arm_relobj =
8672 Arm_relobj<big_endian>::as_arm_relobj(*p);
8673 if (arm_relobj->merge_flags_and_attributes())
8674 {
8675 this->merge_processor_specific_flags(
8676 arm_relobj->name(),
8677 arm_relobj->processor_specific_flags());
8678 this->merge_object_attributes(arm_relobj->name().c_str(),
8679 arm_relobj->attributes_section_data());
8680 merged_any_attributes = true;
8681 }
8682 }
8683
8684 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8685 p != input_objects->dynobj_end();
8686 ++p)
8687 {
8688 Arm_dynobj<big_endian>* arm_dynobj =
8689 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8690 this->merge_processor_specific_flags(
8691 arm_dynobj->name(),
8692 arm_dynobj->processor_specific_flags());
8693 this->merge_object_attributes(arm_dynobj->name().c_str(),
8694 arm_dynobj->attributes_section_data());
8695 merged_any_attributes = true;
8696 }
8697
8698 // Create an empty uninitialized attribute section if we still don't have it
8699 // at this moment. This happens if there is no attributes sections in all
8700 // inputs.
8701 if (this->attributes_section_data_ == NULL)
8702 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8703
8704 const Object_attribute* cpu_arch_attr =
8705 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8706 // Check if we need to use Cortex-A8 workaround.
8707 if (parameters->options().user_set_fix_cortex_a8())
8708 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8709 else
8710 {
8711 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8712 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8713 // profile.
8714 const Object_attribute* cpu_arch_profile_attr =
8715 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8716 this->fix_cortex_a8_ =
8717 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8718 && (cpu_arch_profile_attr->int_value() == 'A'
8719 || cpu_arch_profile_attr->int_value() == 0));
8720 }
8721
8722 // Check if we can use V4BX interworking.
8723 // The V4BX interworking stub contains BX instruction,
8724 // which is not specified for some profiles.
8725 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8726 && !this->may_use_v4t_interworking())
8727 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8728 "the target profile does not support BX instruction"));
8729
8730 // Fill in some more dynamic tags.
8731 const Reloc_section* rel_plt = (this->plt_ == NULL
8732 ? NULL
8733 : this->plt_->rel_plt());
8734 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8735 this->rel_dyn_, true, false);
8736
8737 // Emit any relocs we saved in an attempt to avoid generating COPY
8738 // relocs.
8739 if (this->copy_relocs_.any_saved_relocs())
8740 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8741
8742 // Handle the .ARM.exidx section.
8743 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8744
8745 if (!parameters->options().relocatable())
8746 {
8747 if (exidx_section != NULL
8748 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8749 {
8750 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8751 // the .ARM.exidx section.
8752 if (!layout->script_options()->saw_phdrs_clause())
8753 {
8754 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8755 0)
8756 == NULL);
8757 Output_segment* exidx_segment =
8758 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8759 exidx_segment->add_output_section_to_nonload(exidx_section,
8760 elfcpp::PF_R);
8761 }
8762 }
8763 }
8764
8765 // Create an .ARM.attributes section if we have merged any attributes
8766 // from inputs.
8767 if (merged_any_attributes)
8768 {
8769 Output_attributes_section_data* attributes_section =
8770 new Output_attributes_section_data(*this->attributes_section_data_);
8771 layout->add_output_section_data(".ARM.attributes",
8772 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8773 attributes_section, ORDER_INVALID,
8774 false);
8775 }
8776
8777 // Fix up links in section EXIDX headers.
8778 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8779 p != layout->section_list().end();
8780 ++p)
8781 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8782 {
8783 Arm_output_section<big_endian>* os =
8784 Arm_output_section<big_endian>::as_arm_output_section(*p);
8785 os->set_exidx_section_link();
8786 }
8787 }
8788
8789 // Return whether a direct absolute static relocation needs to be applied.
8790 // In cases where Scan::local() or Scan::global() has created
8791 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8792 // of the relocation is carried in the data, and we must not
8793 // apply the static relocation.
8794
8795 template<bool big_endian>
8796 inline bool
8797 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8798 const Sized_symbol<32>* gsym,
8799 unsigned int r_type,
8800 bool is_32bit,
8801 Output_section* output_section)
8802 {
8803 // If the output section is not allocated, then we didn't call
8804 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8805 // the reloc here.
8806 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8807 return true;
8808
8809 int ref_flags = Scan::get_reference_flags(r_type);
8810
8811 // For local symbols, we will have created a non-RELATIVE dynamic
8812 // relocation only if (a) the output is position independent,
8813 // (b) the relocation is absolute (not pc- or segment-relative), and
8814 // (c) the relocation is not 32 bits wide.
8815 if (gsym == NULL)
8816 return !(parameters->options().output_is_position_independent()
8817 && (ref_flags & Symbol::ABSOLUTE_REF)
8818 && !is_32bit);
8819
8820 // For global symbols, we use the same helper routines used in the
8821 // scan pass. If we did not create a dynamic relocation, or if we
8822 // created a RELATIVE dynamic relocation, we should apply the static
8823 // relocation.
8824 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8825 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8826 && gsym->can_use_relative_reloc(ref_flags
8827 & Symbol::FUNCTION_CALL);
8828 return !has_dyn || is_rel;
8829 }
8830
8831 // Perform a relocation.
8832
8833 template<bool big_endian>
8834 inline bool
8835 Target_arm<big_endian>::Relocate::relocate(
8836 const Relocate_info<32, big_endian>* relinfo,
8837 Target_arm* target,
8838 Output_section* output_section,
8839 size_t relnum,
8840 const elfcpp::Rel<32, big_endian>& rel,
8841 unsigned int r_type,
8842 const Sized_symbol<32>* gsym,
8843 const Symbol_value<32>* psymval,
8844 unsigned char* view,
8845 Arm_address address,
8846 section_size_type view_size)
8847 {
8848 if (view == NULL)
8849 return true;
8850
8851 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8852
8853 r_type = get_real_reloc_type(r_type);
8854 const Arm_reloc_property* reloc_property =
8855 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8856 if (reloc_property == NULL)
8857 {
8858 std::string reloc_name =
8859 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8860 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8861 _("cannot relocate %s in object file"),
8862 reloc_name.c_str());
8863 return true;
8864 }
8865
8866 const Arm_relobj<big_endian>* object =
8867 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8868
8869 // If the final branch target of a relocation is THUMB instruction, this
8870 // is 1. Otherwise it is 0.
8871 Arm_address thumb_bit = 0;
8872 Symbol_value<32> symval;
8873 bool is_weakly_undefined_without_plt = false;
8874 bool have_got_offset = false;
8875 unsigned int got_offset = 0;
8876
8877 // If the relocation uses the GOT entry of a symbol instead of the symbol
8878 // itself, we don't care about whether the symbol is defined or what kind
8879 // of symbol it is.
8880 if (reloc_property->uses_got_entry())
8881 {
8882 // Get the GOT offset.
8883 // The GOT pointer points to the end of the GOT section.
8884 // We need to subtract the size of the GOT section to get
8885 // the actual offset to use in the relocation.
8886 // TODO: We should move GOT offset computing code in TLS relocations
8887 // to here.
8888 switch (r_type)
8889 {
8890 case elfcpp::R_ARM_GOT_BREL:
8891 case elfcpp::R_ARM_GOT_PREL:
8892 if (gsym != NULL)
8893 {
8894 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8895 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8896 - target->got_size());
8897 }
8898 else
8899 {
8900 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8901 gold_assert(object->local_has_got_offset(r_sym,
8902 GOT_TYPE_STANDARD));
8903 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8904 - target->got_size());
8905 }
8906 have_got_offset = true;
8907 break;
8908
8909 default:
8910 break;
8911 }
8912 }
8913 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8914 {
8915 if (gsym != NULL)
8916 {
8917 // This is a global symbol. Determine if we use PLT and if the
8918 // final target is THUMB.
8919 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8920 {
8921 // This uses a PLT, change the symbol value.
8922 symval.set_output_value(target->plt_section()->address()
8923 + gsym->plt_offset());
8924 psymval = &symval;
8925 }
8926 else if (gsym->is_weak_undefined())
8927 {
8928 // This is a weakly undefined symbol and we do not use PLT
8929 // for this relocation. A branch targeting this symbol will
8930 // be converted into an NOP.
8931 is_weakly_undefined_without_plt = true;
8932 }
8933 else if (gsym->is_undefined() && reloc_property->uses_symbol())
8934 {
8935 // This relocation uses the symbol value but the symbol is
8936 // undefined. Exit early and have the caller reporting an
8937 // error.
8938 return true;
8939 }
8940 else
8941 {
8942 // Set thumb bit if symbol:
8943 // -Has type STT_ARM_TFUNC or
8944 // -Has type STT_FUNC, is defined and with LSB in value set.
8945 thumb_bit =
8946 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8947 || (gsym->type() == elfcpp::STT_FUNC
8948 && !gsym->is_undefined()
8949 && ((psymval->value(object, 0) & 1) != 0)))
8950 ? 1
8951 : 0);
8952 }
8953 }
8954 else
8955 {
8956 // This is a local symbol. Determine if the final target is THUMB.
8957 // We saved this information when all the local symbols were read.
8958 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8959 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8960 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8961 }
8962 }
8963 else
8964 {
8965 // This is a fake relocation synthesized for a stub. It does not have
8966 // a real symbol. We just look at the LSB of the symbol value to
8967 // determine if the target is THUMB or not.
8968 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8969 }
8970
8971 // Strip LSB if this points to a THUMB target.
8972 if (thumb_bit != 0
8973 && reloc_property->uses_thumb_bit()
8974 && ((psymval->value(object, 0) & 1) != 0))
8975 {
8976 Arm_address stripped_value =
8977 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8978 symval.set_output_value(stripped_value);
8979 psymval = &symval;
8980 }
8981
8982 // To look up relocation stubs, we need to pass the symbol table index of
8983 // a local symbol.
8984 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8985
8986 // Get the addressing origin of the output segment defining the
8987 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8988 Arm_address sym_origin = 0;
8989 if (reloc_property->uses_symbol_base())
8990 {
8991 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8992 // R_ARM_BASE_ABS with the NULL symbol will give the
8993 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8994 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8995 sym_origin = target->got_plt_section()->address();
8996 else if (gsym == NULL)
8997 sym_origin = 0;
8998 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8999 sym_origin = gsym->output_segment()->vaddr();
9000 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9001 sym_origin = gsym->output_data()->address();
9002
9003 // TODO: Assumes the segment base to be zero for the global symbols
9004 // till the proper support for the segment-base-relative addressing
9005 // will be implemented. This is consistent with GNU ld.
9006 }
9007
9008 // For relative addressing relocation, find out the relative address base.
9009 Arm_address relative_address_base = 0;
9010 switch(reloc_property->relative_address_base())
9011 {
9012 case Arm_reloc_property::RAB_NONE:
9013 // Relocations with relative address bases RAB_TLS and RAB_tp are
9014 // handled by relocate_tls. So we do not need to do anything here.
9015 case Arm_reloc_property::RAB_TLS:
9016 case Arm_reloc_property::RAB_tp:
9017 break;
9018 case Arm_reloc_property::RAB_B_S:
9019 relative_address_base = sym_origin;
9020 break;
9021 case Arm_reloc_property::RAB_GOT_ORG:
9022 relative_address_base = target->got_plt_section()->address();
9023 break;
9024 case Arm_reloc_property::RAB_P:
9025 relative_address_base = address;
9026 break;
9027 case Arm_reloc_property::RAB_Pa:
9028 relative_address_base = address & 0xfffffffcU;
9029 break;
9030 default:
9031 gold_unreachable();
9032 }
9033
9034 typename Arm_relocate_functions::Status reloc_status =
9035 Arm_relocate_functions::STATUS_OKAY;
9036 bool check_overflow = reloc_property->checks_overflow();
9037 switch (r_type)
9038 {
9039 case elfcpp::R_ARM_NONE:
9040 break;
9041
9042 case elfcpp::R_ARM_ABS8:
9043 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9044 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9045 break;
9046
9047 case elfcpp::R_ARM_ABS12:
9048 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9049 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9050 break;
9051
9052 case elfcpp::R_ARM_ABS16:
9053 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9054 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9055 break;
9056
9057 case elfcpp::R_ARM_ABS32:
9058 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9059 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9060 thumb_bit);
9061 break;
9062
9063 case elfcpp::R_ARM_ABS32_NOI:
9064 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9065 // No thumb bit for this relocation: (S + A)
9066 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9067 0);
9068 break;
9069
9070 case elfcpp::R_ARM_MOVW_ABS_NC:
9071 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9072 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9073 0, thumb_bit,
9074 check_overflow);
9075 break;
9076
9077 case elfcpp::R_ARM_MOVT_ABS:
9078 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9079 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9080 break;
9081
9082 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9083 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9084 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9085 0, thumb_bit, false);
9086 break;
9087
9088 case elfcpp::R_ARM_THM_MOVT_ABS:
9089 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9090 reloc_status = Arm_relocate_functions::thm_movt(view, object,
9091 psymval, 0);
9092 break;
9093
9094 case elfcpp::R_ARM_MOVW_PREL_NC:
9095 case elfcpp::R_ARM_MOVW_BREL_NC:
9096 case elfcpp::R_ARM_MOVW_BREL:
9097 reloc_status =
9098 Arm_relocate_functions::movw(view, object, psymval,
9099 relative_address_base, thumb_bit,
9100 check_overflow);
9101 break;
9102
9103 case elfcpp::R_ARM_MOVT_PREL:
9104 case elfcpp::R_ARM_MOVT_BREL:
9105 reloc_status =
9106 Arm_relocate_functions::movt(view, object, psymval,
9107 relative_address_base);
9108 break;
9109
9110 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9111 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9112 case elfcpp::R_ARM_THM_MOVW_BREL:
9113 reloc_status =
9114 Arm_relocate_functions::thm_movw(view, object, psymval,
9115 relative_address_base,
9116 thumb_bit, check_overflow);
9117 break;
9118
9119 case elfcpp::R_ARM_THM_MOVT_PREL:
9120 case elfcpp::R_ARM_THM_MOVT_BREL:
9121 reloc_status =
9122 Arm_relocate_functions::thm_movt(view, object, psymval,
9123 relative_address_base);
9124 break;
9125
9126 case elfcpp::R_ARM_REL32:
9127 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9128 address, thumb_bit);
9129 break;
9130
9131 case elfcpp::R_ARM_THM_ABS5:
9132 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9133 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9134 break;
9135
9136 // Thumb long branches.
9137 case elfcpp::R_ARM_THM_CALL:
9138 case elfcpp::R_ARM_THM_XPC22:
9139 case elfcpp::R_ARM_THM_JUMP24:
9140 reloc_status =
9141 Arm_relocate_functions::thumb_branch_common(
9142 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9143 thumb_bit, is_weakly_undefined_without_plt);
9144 break;
9145
9146 case elfcpp::R_ARM_GOTOFF32:
9147 {
9148 Arm_address got_origin;
9149 got_origin = target->got_plt_section()->address();
9150 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9151 got_origin, thumb_bit);
9152 }
9153 break;
9154
9155 case elfcpp::R_ARM_BASE_PREL:
9156 gold_assert(gsym != NULL);
9157 reloc_status =
9158 Arm_relocate_functions::base_prel(view, sym_origin, address);
9159 break;
9160
9161 case elfcpp::R_ARM_BASE_ABS:
9162 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9163 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9164 break;
9165
9166 case elfcpp::R_ARM_GOT_BREL:
9167 gold_assert(have_got_offset);
9168 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9169 break;
9170
9171 case elfcpp::R_ARM_GOT_PREL:
9172 gold_assert(have_got_offset);
9173 // Get the address origin for GOT PLT, which is allocated right
9174 // after the GOT section, to calculate an absolute address of
9175 // the symbol GOT entry (got_origin + got_offset).
9176 Arm_address got_origin;
9177 got_origin = target->got_plt_section()->address();
9178 reloc_status = Arm_relocate_functions::got_prel(view,
9179 got_origin + got_offset,
9180 address);
9181 break;
9182
9183 case elfcpp::R_ARM_PLT32:
9184 case elfcpp::R_ARM_CALL:
9185 case elfcpp::R_ARM_JUMP24:
9186 case elfcpp::R_ARM_XPC25:
9187 gold_assert(gsym == NULL
9188 || gsym->has_plt_offset()
9189 || gsym->final_value_is_known()
9190 || (gsym->is_defined()
9191 && !gsym->is_from_dynobj()
9192 && !gsym->is_preemptible()));
9193 reloc_status =
9194 Arm_relocate_functions::arm_branch_common(
9195 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9196 thumb_bit, is_weakly_undefined_without_plt);
9197 break;
9198
9199 case elfcpp::R_ARM_THM_JUMP19:
9200 reloc_status =
9201 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9202 thumb_bit);
9203 break;
9204
9205 case elfcpp::R_ARM_THM_JUMP6:
9206 reloc_status =
9207 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9208 break;
9209
9210 case elfcpp::R_ARM_THM_JUMP8:
9211 reloc_status =
9212 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9213 break;
9214
9215 case elfcpp::R_ARM_THM_JUMP11:
9216 reloc_status =
9217 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9218 break;
9219
9220 case elfcpp::R_ARM_PREL31:
9221 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9222 address, thumb_bit);
9223 break;
9224
9225 case elfcpp::R_ARM_V4BX:
9226 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9227 {
9228 const bool is_v4bx_interworking =
9229 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9230 reloc_status =
9231 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9232 is_v4bx_interworking);
9233 }
9234 break;
9235
9236 case elfcpp::R_ARM_THM_PC8:
9237 reloc_status =
9238 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9239 break;
9240
9241 case elfcpp::R_ARM_THM_PC12:
9242 reloc_status =
9243 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9244 break;
9245
9246 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9247 reloc_status =
9248 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9249 thumb_bit);
9250 break;
9251
9252 case elfcpp::R_ARM_ALU_PC_G0_NC:
9253 case elfcpp::R_ARM_ALU_PC_G0:
9254 case elfcpp::R_ARM_ALU_PC_G1_NC:
9255 case elfcpp::R_ARM_ALU_PC_G1:
9256 case elfcpp::R_ARM_ALU_PC_G2:
9257 case elfcpp::R_ARM_ALU_SB_G0_NC:
9258 case elfcpp::R_ARM_ALU_SB_G0:
9259 case elfcpp::R_ARM_ALU_SB_G1_NC:
9260 case elfcpp::R_ARM_ALU_SB_G1:
9261 case elfcpp::R_ARM_ALU_SB_G2:
9262 reloc_status =
9263 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9264 reloc_property->group_index(),
9265 relative_address_base,
9266 thumb_bit, check_overflow);
9267 break;
9268
9269 case elfcpp::R_ARM_LDR_PC_G0:
9270 case elfcpp::R_ARM_LDR_PC_G1:
9271 case elfcpp::R_ARM_LDR_PC_G2:
9272 case elfcpp::R_ARM_LDR_SB_G0:
9273 case elfcpp::R_ARM_LDR_SB_G1:
9274 case elfcpp::R_ARM_LDR_SB_G2:
9275 reloc_status =
9276 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9277 reloc_property->group_index(),
9278 relative_address_base);
9279 break;
9280
9281 case elfcpp::R_ARM_LDRS_PC_G0:
9282 case elfcpp::R_ARM_LDRS_PC_G1:
9283 case elfcpp::R_ARM_LDRS_PC_G2:
9284 case elfcpp::R_ARM_LDRS_SB_G0:
9285 case elfcpp::R_ARM_LDRS_SB_G1:
9286 case elfcpp::R_ARM_LDRS_SB_G2:
9287 reloc_status =
9288 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9289 reloc_property->group_index(),
9290 relative_address_base);
9291 break;
9292
9293 case elfcpp::R_ARM_LDC_PC_G0:
9294 case elfcpp::R_ARM_LDC_PC_G1:
9295 case elfcpp::R_ARM_LDC_PC_G2:
9296 case elfcpp::R_ARM_LDC_SB_G0:
9297 case elfcpp::R_ARM_LDC_SB_G1:
9298 case elfcpp::R_ARM_LDC_SB_G2:
9299 reloc_status =
9300 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9301 reloc_property->group_index(),
9302 relative_address_base);
9303 break;
9304
9305 // These are initial tls relocs, which are expected when
9306 // linking.
9307 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9308 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9309 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9310 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9311 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9312 reloc_status =
9313 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9314 view, address, view_size);
9315 break;
9316
9317 // The known and unknown unsupported and/or deprecated relocations.
9318 case elfcpp::R_ARM_PC24:
9319 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9320 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9321 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9322 default:
9323 // Just silently leave the method. We should get an appropriate error
9324 // message in the scan methods.
9325 break;
9326 }
9327
9328 // Report any errors.
9329 switch (reloc_status)
9330 {
9331 case Arm_relocate_functions::STATUS_OKAY:
9332 break;
9333 case Arm_relocate_functions::STATUS_OVERFLOW:
9334 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9335 _("relocation overflow in %s"),
9336 reloc_property->name().c_str());
9337 break;
9338 case Arm_relocate_functions::STATUS_BAD_RELOC:
9339 gold_error_at_location(
9340 relinfo,
9341 relnum,
9342 rel.get_r_offset(),
9343 _("unexpected opcode while processing relocation %s"),
9344 reloc_property->name().c_str());
9345 break;
9346 default:
9347 gold_unreachable();
9348 }
9349
9350 return true;
9351 }
9352
9353 // Perform a TLS relocation.
9354
9355 template<bool big_endian>
9356 inline typename Arm_relocate_functions<big_endian>::Status
9357 Target_arm<big_endian>::Relocate::relocate_tls(
9358 const Relocate_info<32, big_endian>* relinfo,
9359 Target_arm<big_endian>* target,
9360 size_t relnum,
9361 const elfcpp::Rel<32, big_endian>& rel,
9362 unsigned int r_type,
9363 const Sized_symbol<32>* gsym,
9364 const Symbol_value<32>* psymval,
9365 unsigned char* view,
9366 elfcpp::Elf_types<32>::Elf_Addr address,
9367 section_size_type /*view_size*/ )
9368 {
9369 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9370 typedef Relocate_functions<32, big_endian> RelocFuncs;
9371 Output_segment* tls_segment = relinfo->layout->tls_segment();
9372
9373 const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9374
9375 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9376
9377 const bool is_final = (gsym == NULL
9378 ? !parameters->options().shared()
9379 : gsym->final_value_is_known());
9380 const tls::Tls_optimization optimized_type
9381 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9382 switch (r_type)
9383 {
9384 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9385 {
9386 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9387 unsigned int got_offset;
9388 if (gsym != NULL)
9389 {
9390 gold_assert(gsym->has_got_offset(got_type));
9391 got_offset = gsym->got_offset(got_type) - target->got_size();
9392 }
9393 else
9394 {
9395 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9396 gold_assert(object->local_has_got_offset(r_sym, got_type));
9397 got_offset = (object->local_got_offset(r_sym, got_type)
9398 - target->got_size());
9399 }
9400 if (optimized_type == tls::TLSOPT_NONE)
9401 {
9402 Arm_address got_entry =
9403 target->got_plt_section()->address() + got_offset;
9404
9405 // Relocate the field with the PC relative offset of the pair of
9406 // GOT entries.
9407 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9408 return ArmRelocFuncs::STATUS_OKAY;
9409 }
9410 }
9411 break;
9412
9413 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9414 if (optimized_type == tls::TLSOPT_NONE)
9415 {
9416 // Relocate the field with the offset of the GOT entry for
9417 // the module index.
9418 unsigned int got_offset;
9419 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9420 - target->got_size());
9421 Arm_address got_entry =
9422 target->got_plt_section()->address() + got_offset;
9423
9424 // Relocate the field with the PC relative offset of the pair of
9425 // GOT entries.
9426 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9427 return ArmRelocFuncs::STATUS_OKAY;
9428 }
9429 break;
9430
9431 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9432 RelocFuncs::rel32_unaligned(view, value);
9433 return ArmRelocFuncs::STATUS_OKAY;
9434
9435 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9436 if (optimized_type == tls::TLSOPT_NONE)
9437 {
9438 // Relocate the field with the offset of the GOT entry for
9439 // the tp-relative offset of the symbol.
9440 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9441 unsigned int got_offset;
9442 if (gsym != NULL)
9443 {
9444 gold_assert(gsym->has_got_offset(got_type));
9445 got_offset = gsym->got_offset(got_type);
9446 }
9447 else
9448 {
9449 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9450 gold_assert(object->local_has_got_offset(r_sym, got_type));
9451 got_offset = object->local_got_offset(r_sym, got_type);
9452 }
9453
9454 // All GOT offsets are relative to the end of the GOT.
9455 got_offset -= target->got_size();
9456
9457 Arm_address got_entry =
9458 target->got_plt_section()->address() + got_offset;
9459
9460 // Relocate the field with the PC relative offset of the GOT entry.
9461 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9462 return ArmRelocFuncs::STATUS_OKAY;
9463 }
9464 break;
9465
9466 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9467 // If we're creating a shared library, a dynamic relocation will
9468 // have been created for this location, so do not apply it now.
9469 if (!parameters->options().shared())
9470 {
9471 gold_assert(tls_segment != NULL);
9472
9473 // $tp points to the TCB, which is followed by the TLS, so we
9474 // need to add TCB size to the offset.
9475 Arm_address aligned_tcb_size =
9476 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9477 RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9478
9479 }
9480 return ArmRelocFuncs::STATUS_OKAY;
9481
9482 default:
9483 gold_unreachable();
9484 }
9485
9486 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9487 _("unsupported reloc %u"),
9488 r_type);
9489 return ArmRelocFuncs::STATUS_BAD_RELOC;
9490 }
9491
9492 // Relocate section data.
9493
9494 template<bool big_endian>
9495 void
9496 Target_arm<big_endian>::relocate_section(
9497 const Relocate_info<32, big_endian>* relinfo,
9498 unsigned int sh_type,
9499 const unsigned char* prelocs,
9500 size_t reloc_count,
9501 Output_section* output_section,
9502 bool needs_special_offset_handling,
9503 unsigned char* view,
9504 Arm_address address,
9505 section_size_type view_size,
9506 const Reloc_symbol_changes* reloc_symbol_changes)
9507 {
9508 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9509 gold_assert(sh_type == elfcpp::SHT_REL);
9510
9511 // See if we are relocating a relaxed input section. If so, the view
9512 // covers the whole output section and we need to adjust accordingly.
9513 if (needs_special_offset_handling)
9514 {
9515 const Output_relaxed_input_section* poris =
9516 output_section->find_relaxed_input_section(relinfo->object,
9517 relinfo->data_shndx);
9518 if (poris != NULL)
9519 {
9520 Arm_address section_address = poris->address();
9521 section_size_type section_size = poris->data_size();
9522
9523 gold_assert((section_address >= address)
9524 && ((section_address + section_size)
9525 <= (address + view_size)));
9526
9527 off_t offset = section_address - address;
9528 view += offset;
9529 address += offset;
9530 view_size = section_size;
9531 }
9532 }
9533
9534 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9535 Arm_relocate, gold::Default_comdat_behavior>(
9536 relinfo,
9537 this,
9538 prelocs,
9539 reloc_count,
9540 output_section,
9541 needs_special_offset_handling,
9542 view,
9543 address,
9544 view_size,
9545 reloc_symbol_changes);
9546 }
9547
9548 // Return the size of a relocation while scanning during a relocatable
9549 // link.
9550
9551 template<bool big_endian>
9552 unsigned int
9553 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9554 unsigned int r_type,
9555 Relobj* object)
9556 {
9557 r_type = get_real_reloc_type(r_type);
9558 const Arm_reloc_property* arp =
9559 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9560 if (arp != NULL)
9561 return arp->size();
9562 else
9563 {
9564 std::string reloc_name =
9565 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9566 gold_error(_("%s: unexpected %s in object file"),
9567 object->name().c_str(), reloc_name.c_str());
9568 return 0;
9569 }
9570 }
9571
9572 // Scan the relocs during a relocatable link.
9573
9574 template<bool big_endian>
9575 void
9576 Target_arm<big_endian>::scan_relocatable_relocs(
9577 Symbol_table* symtab,
9578 Layout* layout,
9579 Sized_relobj_file<32, big_endian>* object,
9580 unsigned int data_shndx,
9581 unsigned int sh_type,
9582 const unsigned char* prelocs,
9583 size_t reloc_count,
9584 Output_section* output_section,
9585 bool needs_special_offset_handling,
9586 size_t local_symbol_count,
9587 const unsigned char* plocal_symbols,
9588 Relocatable_relocs* rr)
9589 {
9590 gold_assert(sh_type == elfcpp::SHT_REL);
9591
9592 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9593 Relocatable_size_for_reloc> Scan_relocatable_relocs;
9594
9595 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9596 Scan_relocatable_relocs>(
9597 symtab,
9598 layout,
9599 object,
9600 data_shndx,
9601 prelocs,
9602 reloc_count,
9603 output_section,
9604 needs_special_offset_handling,
9605 local_symbol_count,
9606 plocal_symbols,
9607 rr);
9608 }
9609
9610 // Emit relocations for a section.
9611
9612 template<bool big_endian>
9613 void
9614 Target_arm<big_endian>::relocate_relocs(
9615 const Relocate_info<32, big_endian>* relinfo,
9616 unsigned int sh_type,
9617 const unsigned char* prelocs,
9618 size_t reloc_count,
9619 Output_section* output_section,
9620 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9621 const Relocatable_relocs* rr,
9622 unsigned char* view,
9623 Arm_address view_address,
9624 section_size_type view_size,
9625 unsigned char* reloc_view,
9626 section_size_type reloc_view_size)
9627 {
9628 gold_assert(sh_type == elfcpp::SHT_REL);
9629
9630 gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
9631 relinfo,
9632 prelocs,
9633 reloc_count,
9634 output_section,
9635 offset_in_output_section,
9636 rr,
9637 view,
9638 view_address,
9639 view_size,
9640 reloc_view,
9641 reloc_view_size);
9642 }
9643
9644 // Perform target-specific processing in a relocatable link. This is
9645 // only used if we use the relocation strategy RELOC_SPECIAL.
9646
9647 template<bool big_endian>
9648 void
9649 Target_arm<big_endian>::relocate_special_relocatable(
9650 const Relocate_info<32, big_endian>* relinfo,
9651 unsigned int sh_type,
9652 const unsigned char* preloc_in,
9653 size_t relnum,
9654 Output_section* output_section,
9655 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9656 unsigned char* view,
9657 elfcpp::Elf_types<32>::Elf_Addr view_address,
9658 section_size_type,
9659 unsigned char* preloc_out)
9660 {
9661 // We can only handle REL type relocation sections.
9662 gold_assert(sh_type == elfcpp::SHT_REL);
9663
9664 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9665 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9666 Reltype_write;
9667 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9668
9669 const Arm_relobj<big_endian>* object =
9670 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9671 const unsigned int local_count = object->local_symbol_count();
9672
9673 Reltype reloc(preloc_in);
9674 Reltype_write reloc_write(preloc_out);
9675
9676 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9677 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9678 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9679
9680 const Arm_reloc_property* arp =
9681 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9682 gold_assert(arp != NULL);
9683
9684 // Get the new symbol index.
9685 // We only use RELOC_SPECIAL strategy in local relocations.
9686 gold_assert(r_sym < local_count);
9687
9688 // We are adjusting a section symbol. We need to find
9689 // the symbol table index of the section symbol for
9690 // the output section corresponding to input section
9691 // in which this symbol is defined.
9692 bool is_ordinary;
9693 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9694 gold_assert(is_ordinary);
9695 Output_section* os = object->output_section(shndx);
9696 gold_assert(os != NULL);
9697 gold_assert(os->needs_symtab_index());
9698 unsigned int new_symndx = os->symtab_index();
9699
9700 // Get the new offset--the location in the output section where
9701 // this relocation should be applied.
9702
9703 Arm_address offset = reloc.get_r_offset();
9704 Arm_address new_offset;
9705 if (offset_in_output_section != invalid_address)
9706 new_offset = offset + offset_in_output_section;
9707 else
9708 {
9709 section_offset_type sot_offset =
9710 convert_types<section_offset_type, Arm_address>(offset);
9711 section_offset_type new_sot_offset =
9712 output_section->output_offset(object, relinfo->data_shndx,
9713 sot_offset);
9714 gold_assert(new_sot_offset != -1);
9715 new_offset = new_sot_offset;
9716 }
9717
9718 // In an object file, r_offset is an offset within the section.
9719 // In an executable or dynamic object, generated by
9720 // --emit-relocs, r_offset is an absolute address.
9721 if (!parameters->options().relocatable())
9722 {
9723 new_offset += view_address;
9724 if (offset_in_output_section != invalid_address)
9725 new_offset -= offset_in_output_section;
9726 }
9727
9728 reloc_write.put_r_offset(new_offset);
9729 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9730
9731 // Handle the reloc addend.
9732 // The relocation uses a section symbol in the input file.
9733 // We are adjusting it to use a section symbol in the output
9734 // file. The input section symbol refers to some address in
9735 // the input section. We need the relocation in the output
9736 // file to refer to that same address. This adjustment to
9737 // the addend is the same calculation we use for a simple
9738 // absolute relocation for the input section symbol.
9739
9740 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9741
9742 // Handle THUMB bit.
9743 Symbol_value<32> symval;
9744 Arm_address thumb_bit =
9745 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9746 if (thumb_bit != 0
9747 && arp->uses_thumb_bit()
9748 && ((psymval->value(object, 0) & 1) != 0))
9749 {
9750 Arm_address stripped_value =
9751 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9752 symval.set_output_value(stripped_value);
9753 psymval = &symval;
9754 }
9755
9756 unsigned char* paddend = view + offset;
9757 typename Arm_relocate_functions<big_endian>::Status reloc_status =
9758 Arm_relocate_functions<big_endian>::STATUS_OKAY;
9759 switch (r_type)
9760 {
9761 case elfcpp::R_ARM_ABS8:
9762 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9763 psymval);
9764 break;
9765
9766 case elfcpp::R_ARM_ABS12:
9767 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9768 psymval);
9769 break;
9770
9771 case elfcpp::R_ARM_ABS16:
9772 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9773 psymval);
9774 break;
9775
9776 case elfcpp::R_ARM_THM_ABS5:
9777 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9778 object,
9779 psymval);
9780 break;
9781
9782 case elfcpp::R_ARM_MOVW_ABS_NC:
9783 case elfcpp::R_ARM_MOVW_PREL_NC:
9784 case elfcpp::R_ARM_MOVW_BREL_NC:
9785 case elfcpp::R_ARM_MOVW_BREL:
9786 reloc_status = Arm_relocate_functions<big_endian>::movw(
9787 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9788 break;
9789
9790 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9791 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9792 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9793 case elfcpp::R_ARM_THM_MOVW_BREL:
9794 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9795 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9796 break;
9797
9798 case elfcpp::R_ARM_THM_CALL:
9799 case elfcpp::R_ARM_THM_XPC22:
9800 case elfcpp::R_ARM_THM_JUMP24:
9801 reloc_status =
9802 Arm_relocate_functions<big_endian>::thumb_branch_common(
9803 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9804 false);
9805 break;
9806
9807 case elfcpp::R_ARM_PLT32:
9808 case elfcpp::R_ARM_CALL:
9809 case elfcpp::R_ARM_JUMP24:
9810 case elfcpp::R_ARM_XPC25:
9811 reloc_status =
9812 Arm_relocate_functions<big_endian>::arm_branch_common(
9813 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9814 false);
9815 break;
9816
9817 case elfcpp::R_ARM_THM_JUMP19:
9818 reloc_status =
9819 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9820 psymval, 0, thumb_bit);
9821 break;
9822
9823 case elfcpp::R_ARM_THM_JUMP6:
9824 reloc_status =
9825 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9826 0);
9827 break;
9828
9829 case elfcpp::R_ARM_THM_JUMP8:
9830 reloc_status =
9831 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9832 0);
9833 break;
9834
9835 case elfcpp::R_ARM_THM_JUMP11:
9836 reloc_status =
9837 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9838 0);
9839 break;
9840
9841 case elfcpp::R_ARM_PREL31:
9842 reloc_status =
9843 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9844 thumb_bit);
9845 break;
9846
9847 case elfcpp::R_ARM_THM_PC8:
9848 reloc_status =
9849 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9850 0);
9851 break;
9852
9853 case elfcpp::R_ARM_THM_PC12:
9854 reloc_status =
9855 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9856 0);
9857 break;
9858
9859 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9860 reloc_status =
9861 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9862 0, thumb_bit);
9863 break;
9864
9865 // These relocation truncate relocation results so we cannot handle them
9866 // in a relocatable link.
9867 case elfcpp::R_ARM_MOVT_ABS:
9868 case elfcpp::R_ARM_THM_MOVT_ABS:
9869 case elfcpp::R_ARM_MOVT_PREL:
9870 case elfcpp::R_ARM_MOVT_BREL:
9871 case elfcpp::R_ARM_THM_MOVT_PREL:
9872 case elfcpp::R_ARM_THM_MOVT_BREL:
9873 case elfcpp::R_ARM_ALU_PC_G0_NC:
9874 case elfcpp::R_ARM_ALU_PC_G0:
9875 case elfcpp::R_ARM_ALU_PC_G1_NC:
9876 case elfcpp::R_ARM_ALU_PC_G1:
9877 case elfcpp::R_ARM_ALU_PC_G2:
9878 case elfcpp::R_ARM_ALU_SB_G0_NC:
9879 case elfcpp::R_ARM_ALU_SB_G0:
9880 case elfcpp::R_ARM_ALU_SB_G1_NC:
9881 case elfcpp::R_ARM_ALU_SB_G1:
9882 case elfcpp::R_ARM_ALU_SB_G2:
9883 case elfcpp::R_ARM_LDR_PC_G0:
9884 case elfcpp::R_ARM_LDR_PC_G1:
9885 case elfcpp::R_ARM_LDR_PC_G2:
9886 case elfcpp::R_ARM_LDR_SB_G0:
9887 case elfcpp::R_ARM_LDR_SB_G1:
9888 case elfcpp::R_ARM_LDR_SB_G2:
9889 case elfcpp::R_ARM_LDRS_PC_G0:
9890 case elfcpp::R_ARM_LDRS_PC_G1:
9891 case elfcpp::R_ARM_LDRS_PC_G2:
9892 case elfcpp::R_ARM_LDRS_SB_G0:
9893 case elfcpp::R_ARM_LDRS_SB_G1:
9894 case elfcpp::R_ARM_LDRS_SB_G2:
9895 case elfcpp::R_ARM_LDC_PC_G0:
9896 case elfcpp::R_ARM_LDC_PC_G1:
9897 case elfcpp::R_ARM_LDC_PC_G2:
9898 case elfcpp::R_ARM_LDC_SB_G0:
9899 case elfcpp::R_ARM_LDC_SB_G1:
9900 case elfcpp::R_ARM_LDC_SB_G2:
9901 gold_error(_("cannot handle %s in a relocatable link"),
9902 arp->name().c_str());
9903 break;
9904
9905 default:
9906 gold_unreachable();
9907 }
9908
9909 // Report any errors.
9910 switch (reloc_status)
9911 {
9912 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9913 break;
9914 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9915 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9916 _("relocation overflow in %s"),
9917 arp->name().c_str());
9918 break;
9919 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9920 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9921 _("unexpected opcode while processing relocation %s"),
9922 arp->name().c_str());
9923 break;
9924 default:
9925 gold_unreachable();
9926 }
9927 }
9928
9929 // Return the value to use for a dynamic symbol which requires special
9930 // treatment. This is how we support equality comparisons of function
9931 // pointers across shared library boundaries, as described in the
9932 // processor specific ABI supplement.
9933
9934 template<bool big_endian>
9935 uint64_t
9936 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9937 {
9938 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9939 return this->plt_section()->address() + gsym->plt_offset();
9940 }
9941
9942 // Map platform-specific relocs to real relocs
9943 //
9944 template<bool big_endian>
9945 unsigned int
9946 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9947 {
9948 switch (r_type)
9949 {
9950 case elfcpp::R_ARM_TARGET1:
9951 // This is either R_ARM_ABS32 or R_ARM_REL32;
9952 return elfcpp::R_ARM_ABS32;
9953
9954 case elfcpp::R_ARM_TARGET2:
9955 // This can be any reloc type but usually is R_ARM_GOT_PREL
9956 return elfcpp::R_ARM_GOT_PREL;
9957
9958 default:
9959 return r_type;
9960 }
9961 }
9962
9963 // Whether if two EABI versions V1 and V2 are compatible.
9964
9965 template<bool big_endian>
9966 bool
9967 Target_arm<big_endian>::are_eabi_versions_compatible(
9968 elfcpp::Elf_Word v1,
9969 elfcpp::Elf_Word v2)
9970 {
9971 // v4 and v5 are the same spec before and after it was released,
9972 // so allow mixing them.
9973 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9974 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9975 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9976 return true;
9977
9978 return v1 == v2;
9979 }
9980
9981 // Combine FLAGS from an input object called NAME and the processor-specific
9982 // flags in the ELF header of the output. Much of this is adapted from the
9983 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9984 // in bfd/elf32-arm.c.
9985
9986 template<bool big_endian>
9987 void
9988 Target_arm<big_endian>::merge_processor_specific_flags(
9989 const std::string& name,
9990 elfcpp::Elf_Word flags)
9991 {
9992 if (this->are_processor_specific_flags_set())
9993 {
9994 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9995
9996 // Nothing to merge if flags equal to those in output.
9997 if (flags == out_flags)
9998 return;
9999
10000 // Complain about various flag mismatches.
10001 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10002 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10003 if (!this->are_eabi_versions_compatible(version1, version2)
10004 && parameters->options().warn_mismatch())
10005 gold_error(_("Source object %s has EABI version %d but output has "
10006 "EABI version %d."),
10007 name.c_str(),
10008 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10009 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10010 }
10011 else
10012 {
10013 // If the input is the default architecture and had the default
10014 // flags then do not bother setting the flags for the output
10015 // architecture, instead allow future merges to do this. If no
10016 // future merges ever set these flags then they will retain their
10017 // uninitialised values, which surprise surprise, correspond
10018 // to the default values.
10019 if (flags == 0)
10020 return;
10021
10022 // This is the first time, just copy the flags.
10023 // We only copy the EABI version for now.
10024 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10025 }
10026 }
10027
10028 // Adjust ELF file header.
10029 template<bool big_endian>
10030 void
10031 Target_arm<big_endian>::do_adjust_elf_header(
10032 unsigned char* view,
10033 int len)
10034 {
10035 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10036
10037 elfcpp::Ehdr<32, big_endian> ehdr(view);
10038 elfcpp::Elf_Word flags = this->processor_specific_flags();
10039 unsigned char e_ident[elfcpp::EI_NIDENT];
10040 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10041
10042 if (elfcpp::arm_eabi_version(flags)
10043 == elfcpp::EF_ARM_EABI_UNKNOWN)
10044 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10045 else
10046 e_ident[elfcpp::EI_OSABI] = 0;
10047 e_ident[elfcpp::EI_ABIVERSION] = 0;
10048
10049 // FIXME: Do EF_ARM_BE8 adjustment.
10050
10051 // If we're working in EABI_VER5, set the hard/soft float ABI flags
10052 // as appropriate.
10053 if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10054 {
10055 elfcpp::Elf_Half type = ehdr.get_e_type();
10056 if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10057 {
10058 Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10059 if (attr->int_value() == elfcpp::AEABI_VFP_args_vfp)
10060 flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10061 else
10062 flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10063 this->set_processor_specific_flags(flags);
10064 }
10065 }
10066 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10067 oehdr.put_e_ident(e_ident);
10068 }
10069
10070 // do_make_elf_object to override the same function in the base class.
10071 // We need to use a target-specific sub-class of
10072 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10073 // Hence we need to have our own ELF object creation.
10074
10075 template<bool big_endian>
10076 Object*
10077 Target_arm<big_endian>::do_make_elf_object(
10078 const std::string& name,
10079 Input_file* input_file,
10080 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10081 {
10082 int et = ehdr.get_e_type();
10083 // ET_EXEC files are valid input for --just-symbols/-R,
10084 // and we treat them as relocatable objects.
10085 if (et == elfcpp::ET_REL
10086 || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10087 {
10088 Arm_relobj<big_endian>* obj =
10089 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10090 obj->setup();
10091 return obj;
10092 }
10093 else if (et == elfcpp::ET_DYN)
10094 {
10095 Sized_dynobj<32, big_endian>* obj =
10096 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10097 obj->setup();
10098 return obj;
10099 }
10100 else
10101 {
10102 gold_error(_("%s: unsupported ELF file type %d"),
10103 name.c_str(), et);
10104 return NULL;
10105 }
10106 }
10107
10108 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10109 // Returns -1 if no architecture could be read.
10110 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10111
10112 template<bool big_endian>
10113 int
10114 Target_arm<big_endian>::get_secondary_compatible_arch(
10115 const Attributes_section_data* pasd)
10116 {
10117 const Object_attribute* known_attributes =
10118 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10119
10120 // Note: the tag and its argument below are uleb128 values, though
10121 // currently-defined values fit in one byte for each.
10122 const std::string& sv =
10123 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10124 if (sv.size() == 2
10125 && sv.data()[0] == elfcpp::Tag_CPU_arch
10126 && (sv.data()[1] & 128) != 128)
10127 return sv.data()[1];
10128
10129 // This tag is "safely ignorable", so don't complain if it looks funny.
10130 return -1;
10131 }
10132
10133 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10134 // The tag is removed if ARCH is -1.
10135 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10136
10137 template<bool big_endian>
10138 void
10139 Target_arm<big_endian>::set_secondary_compatible_arch(
10140 Attributes_section_data* pasd,
10141 int arch)
10142 {
10143 Object_attribute* known_attributes =
10144 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10145
10146 if (arch == -1)
10147 {
10148 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10149 return;
10150 }
10151
10152 // Note: the tag and its argument below are uleb128 values, though
10153 // currently-defined values fit in one byte for each.
10154 char sv[3];
10155 sv[0] = elfcpp::Tag_CPU_arch;
10156 gold_assert(arch != 0);
10157 sv[1] = arch;
10158 sv[2] = '\0';
10159
10160 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10161 }
10162
10163 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10164 // into account.
10165 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10166
10167 template<bool big_endian>
10168 int
10169 Target_arm<big_endian>::tag_cpu_arch_combine(
10170 const char* name,
10171 int oldtag,
10172 int* secondary_compat_out,
10173 int newtag,
10174 int secondary_compat)
10175 {
10176 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10177 static const int v6t2[] =
10178 {
10179 T(V6T2), // PRE_V4.
10180 T(V6T2), // V4.
10181 T(V6T2), // V4T.
10182 T(V6T2), // V5T.
10183 T(V6T2), // V5TE.
10184 T(V6T2), // V5TEJ.
10185 T(V6T2), // V6.
10186 T(V7), // V6KZ.
10187 T(V6T2) // V6T2.
10188 };
10189 static const int v6k[] =
10190 {
10191 T(V6K), // PRE_V4.
10192 T(V6K), // V4.
10193 T(V6K), // V4T.
10194 T(V6K), // V5T.
10195 T(V6K), // V5TE.
10196 T(V6K), // V5TEJ.
10197 T(V6K), // V6.
10198 T(V6KZ), // V6KZ.
10199 T(V7), // V6T2.
10200 T(V6K) // V6K.
10201 };
10202 static const int v7[] =
10203 {
10204 T(V7), // PRE_V4.
10205 T(V7), // V4.
10206 T(V7), // V4T.
10207 T(V7), // V5T.
10208 T(V7), // V5TE.
10209 T(V7), // V5TEJ.
10210 T(V7), // V6.
10211 T(V7), // V6KZ.
10212 T(V7), // V6T2.
10213 T(V7), // V6K.
10214 T(V7) // V7.
10215 };
10216 static const int v6_m[] =
10217 {
10218 -1, // PRE_V4.
10219 -1, // V4.
10220 T(V6K), // V4T.
10221 T(V6K), // V5T.
10222 T(V6K), // V5TE.
10223 T(V6K), // V5TEJ.
10224 T(V6K), // V6.
10225 T(V6KZ), // V6KZ.
10226 T(V7), // V6T2.
10227 T(V6K), // V6K.
10228 T(V7), // V7.
10229 T(V6_M) // V6_M.
10230 };
10231 static const int v6s_m[] =
10232 {
10233 -1, // PRE_V4.
10234 -1, // V4.
10235 T(V6K), // V4T.
10236 T(V6K), // V5T.
10237 T(V6K), // V5TE.
10238 T(V6K), // V5TEJ.
10239 T(V6K), // V6.
10240 T(V6KZ), // V6KZ.
10241 T(V7), // V6T2.
10242 T(V6K), // V6K.
10243 T(V7), // V7.
10244 T(V6S_M), // V6_M.
10245 T(V6S_M) // V6S_M.
10246 };
10247 static const int v7e_m[] =
10248 {
10249 -1, // PRE_V4.
10250 -1, // V4.
10251 T(V7E_M), // V4T.
10252 T(V7E_M), // V5T.
10253 T(V7E_M), // V5TE.
10254 T(V7E_M), // V5TEJ.
10255 T(V7E_M), // V6.
10256 T(V7E_M), // V6KZ.
10257 T(V7E_M), // V6T2.
10258 T(V7E_M), // V6K.
10259 T(V7E_M), // V7.
10260 T(V7E_M), // V6_M.
10261 T(V7E_M), // V6S_M.
10262 T(V7E_M) // V7E_M.
10263 };
10264 static const int v4t_plus_v6_m[] =
10265 {
10266 -1, // PRE_V4.
10267 -1, // V4.
10268 T(V4T), // V4T.
10269 T(V5T), // V5T.
10270 T(V5TE), // V5TE.
10271 T(V5TEJ), // V5TEJ.
10272 T(V6), // V6.
10273 T(V6KZ), // V6KZ.
10274 T(V6T2), // V6T2.
10275 T(V6K), // V6K.
10276 T(V7), // V7.
10277 T(V6_M), // V6_M.
10278 T(V6S_M), // V6S_M.
10279 T(V7E_M), // V7E_M.
10280 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10281 };
10282 static const int* comb[] =
10283 {
10284 v6t2,
10285 v6k,
10286 v7,
10287 v6_m,
10288 v6s_m,
10289 v7e_m,
10290 // Pseudo-architecture.
10291 v4t_plus_v6_m
10292 };
10293
10294 // Check we've not got a higher architecture than we know about.
10295
10296 if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10297 {
10298 gold_error(_("%s: unknown CPU architecture"), name);
10299 return -1;
10300 }
10301
10302 // Override old tag if we have a Tag_also_compatible_with on the output.
10303
10304 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10305 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10306 oldtag = T(V4T_PLUS_V6_M);
10307
10308 // And override the new tag if we have a Tag_also_compatible_with on the
10309 // input.
10310
10311 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10312 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10313 newtag = T(V4T_PLUS_V6_M);
10314
10315 // Architectures before V6KZ add features monotonically.
10316 int tagh = std::max(oldtag, newtag);
10317 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10318 return tagh;
10319
10320 int tagl = std::min(oldtag, newtag);
10321 int result = comb[tagh - T(V6T2)][tagl];
10322
10323 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10324 // as the canonical version.
10325 if (result == T(V4T_PLUS_V6_M))
10326 {
10327 result = T(V4T);
10328 *secondary_compat_out = T(V6_M);
10329 }
10330 else
10331 *secondary_compat_out = -1;
10332
10333 if (result == -1)
10334 {
10335 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10336 name, oldtag, newtag);
10337 return -1;
10338 }
10339
10340 return result;
10341 #undef T
10342 }
10343
10344 // Helper to print AEABI enum tag value.
10345
10346 template<bool big_endian>
10347 std::string
10348 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10349 {
10350 static const char* aeabi_enum_names[] =
10351 { "", "variable-size", "32-bit", "" };
10352 const size_t aeabi_enum_names_size =
10353 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10354
10355 if (value < aeabi_enum_names_size)
10356 return std::string(aeabi_enum_names[value]);
10357 else
10358 {
10359 char buffer[100];
10360 sprintf(buffer, "<unknown value %u>", value);
10361 return std::string(buffer);
10362 }
10363 }
10364
10365 // Return the string value to store in TAG_CPU_name.
10366
10367 template<bool big_endian>
10368 std::string
10369 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10370 {
10371 static const char* name_table[] = {
10372 // These aren't real CPU names, but we can't guess
10373 // that from the architecture version alone.
10374 "Pre v4",
10375 "ARM v4",
10376 "ARM v4T",
10377 "ARM v5T",
10378 "ARM v5TE",
10379 "ARM v5TEJ",
10380 "ARM v6",
10381 "ARM v6KZ",
10382 "ARM v6T2",
10383 "ARM v6K",
10384 "ARM v7",
10385 "ARM v6-M",
10386 "ARM v6S-M",
10387 "ARM v7E-M"
10388 };
10389 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10390
10391 if (value < name_table_size)
10392 return std::string(name_table[value]);
10393 else
10394 {
10395 char buffer[100];
10396 sprintf(buffer, "<unknown CPU value %u>", value);
10397 return std::string(buffer);
10398 }
10399 }
10400
10401 // Query attributes object to see if integer divide instructions may be
10402 // present in an object.
10403
10404 template<bool big_endian>
10405 bool
10406 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10407 const Object_attribute* div_attr)
10408 {
10409 switch (div_attr->int_value())
10410 {
10411 case 0:
10412 // Integer divide allowed if instruction contained in
10413 // archetecture.
10414 if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10415 return true;
10416 else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10417 return true;
10418 else
10419 return false;
10420
10421 case 1:
10422 // Integer divide explicitly prohibited.
10423 return false;
10424
10425 default:
10426 // Unrecognised case - treat as allowing divide everywhere.
10427 case 2:
10428 // Integer divide allowed in ARM state.
10429 return true;
10430 }
10431 }
10432
10433 // Query attributes object to see if integer divide instructions are
10434 // forbidden to be in the object. This is not the inverse of
10435 // attributes_accept_div.
10436
10437 template<bool big_endian>
10438 bool
10439 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10440 {
10441 return div_attr->int_value() == 1;
10442 }
10443
10444 // Merge object attributes from input file called NAME with those of the
10445 // output. The input object attributes are in the object pointed by PASD.
10446
10447 template<bool big_endian>
10448 void
10449 Target_arm<big_endian>::merge_object_attributes(
10450 const char* name,
10451 const Attributes_section_data* pasd)
10452 {
10453 // Return if there is no attributes section data.
10454 if (pasd == NULL)
10455 return;
10456
10457 // If output has no object attributes, just copy.
10458 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10459 if (this->attributes_section_data_ == NULL)
10460 {
10461 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10462 Object_attribute* out_attr =
10463 this->attributes_section_data_->known_attributes(vendor);
10464
10465 // We do not output objects with Tag_MPextension_use_legacy - we move
10466 // the attribute's value to Tag_MPextension_use. */
10467 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10468 {
10469 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10470 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10471 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10472 {
10473 gold_error(_("%s has both the current and legacy "
10474 "Tag_MPextension_use attributes"),
10475 name);
10476 }
10477
10478 out_attr[elfcpp::Tag_MPextension_use] =
10479 out_attr[elfcpp::Tag_MPextension_use_legacy];
10480 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10481 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10482 }
10483
10484 return;
10485 }
10486
10487 const Object_attribute* in_attr = pasd->known_attributes(vendor);
10488 Object_attribute* out_attr =
10489 this->attributes_section_data_->known_attributes(vendor);
10490
10491 // This needs to happen before Tag_ABI_FP_number_model is merged. */
10492 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10493 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10494 {
10495 // Ignore mismatches if the object doesn't use floating point. */
10496 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
10497 == elfcpp::AEABI_FP_number_model_none
10498 || (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
10499 != elfcpp::AEABI_FP_number_model_none
10500 && out_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10501 == elfcpp::AEABI_VFP_args_compatible))
10502 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10503 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10504 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value()
10505 != elfcpp::AEABI_FP_number_model_none
10506 && in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10507 != elfcpp::AEABI_VFP_args_compatible
10508 && parameters->options().warn_mismatch())
10509 gold_error(_("%s uses VFP register arguments, output does not"),
10510 name);
10511 }
10512
10513 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10514 {
10515 // Merge this attribute with existing attributes.
10516 switch (i)
10517 {
10518 case elfcpp::Tag_CPU_raw_name:
10519 case elfcpp::Tag_CPU_name:
10520 // These are merged after Tag_CPU_arch.
10521 break;
10522
10523 case elfcpp::Tag_ABI_optimization_goals:
10524 case elfcpp::Tag_ABI_FP_optimization_goals:
10525 // Use the first value seen.
10526 break;
10527
10528 case elfcpp::Tag_CPU_arch:
10529 {
10530 unsigned int saved_out_attr = out_attr->int_value();
10531 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10532 int secondary_compat =
10533 this->get_secondary_compatible_arch(pasd);
10534 int secondary_compat_out =
10535 this->get_secondary_compatible_arch(
10536 this->attributes_section_data_);
10537 out_attr[i].set_int_value(
10538 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10539 &secondary_compat_out,
10540 in_attr[i].int_value(),
10541 secondary_compat));
10542 this->set_secondary_compatible_arch(this->attributes_section_data_,
10543 secondary_compat_out);
10544
10545 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10546 if (out_attr[i].int_value() == saved_out_attr)
10547 ; // Leave the names alone.
10548 else if (out_attr[i].int_value() == in_attr[i].int_value())
10549 {
10550 // The output architecture has been changed to match the
10551 // input architecture. Use the input names.
10552 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10553 in_attr[elfcpp::Tag_CPU_name].string_value());
10554 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10555 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10556 }
10557 else
10558 {
10559 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10560 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10561 }
10562
10563 // If we still don't have a value for Tag_CPU_name,
10564 // make one up now. Tag_CPU_raw_name remains blank.
10565 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10566 {
10567 const std::string cpu_name =
10568 this->tag_cpu_name_value(out_attr[i].int_value());
10569 // FIXME: If we see an unknown CPU, this will be set
10570 // to "<unknown CPU n>", where n is the attribute value.
10571 // This is different from BFD, which leaves the name alone.
10572 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10573 }
10574 }
10575 break;
10576
10577 case elfcpp::Tag_ARM_ISA_use:
10578 case elfcpp::Tag_THUMB_ISA_use:
10579 case elfcpp::Tag_WMMX_arch:
10580 case elfcpp::Tag_Advanced_SIMD_arch:
10581 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10582 case elfcpp::Tag_ABI_FP_rounding:
10583 case elfcpp::Tag_ABI_FP_exceptions:
10584 case elfcpp::Tag_ABI_FP_user_exceptions:
10585 case elfcpp::Tag_ABI_FP_number_model:
10586 case elfcpp::Tag_VFP_HP_extension:
10587 case elfcpp::Tag_CPU_unaligned_access:
10588 case elfcpp::Tag_T2EE_use:
10589 case elfcpp::Tag_Virtualization_use:
10590 case elfcpp::Tag_MPextension_use:
10591 // Use the largest value specified.
10592 if (in_attr[i].int_value() > out_attr[i].int_value())
10593 out_attr[i].set_int_value(in_attr[i].int_value());
10594 break;
10595
10596 case elfcpp::Tag_ABI_align8_preserved:
10597 case elfcpp::Tag_ABI_PCS_RO_data:
10598 // Use the smallest value specified.
10599 if (in_attr[i].int_value() < out_attr[i].int_value())
10600 out_attr[i].set_int_value(in_attr[i].int_value());
10601 break;
10602
10603 case elfcpp::Tag_ABI_align8_needed:
10604 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10605 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10606 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10607 == 0)))
10608 {
10609 // This error message should be enabled once all non-conforming
10610 // binaries in the toolchain have had the attributes set
10611 // properly.
10612 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10613 // name);
10614 }
10615 // Fall through.
10616 case elfcpp::Tag_ABI_FP_denormal:
10617 case elfcpp::Tag_ABI_PCS_GOT_use:
10618 {
10619 // These tags have 0 = don't care, 1 = strong requirement,
10620 // 2 = weak requirement.
10621 static const int order_021[3] = {0, 2, 1};
10622
10623 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10624 // value if greater than 2 (for future-proofing).
10625 if ((in_attr[i].int_value() > 2
10626 && in_attr[i].int_value() > out_attr[i].int_value())
10627 || (in_attr[i].int_value() <= 2
10628 && out_attr[i].int_value() <= 2
10629 && (order_021[in_attr[i].int_value()]
10630 > order_021[out_attr[i].int_value()])))
10631 out_attr[i].set_int_value(in_attr[i].int_value());
10632 }
10633 break;
10634
10635 case elfcpp::Tag_CPU_arch_profile:
10636 if (out_attr[i].int_value() != in_attr[i].int_value())
10637 {
10638 // 0 will merge with anything.
10639 // 'A' and 'S' merge to 'A'.
10640 // 'R' and 'S' merge to 'R'.
10641 // 'M' and 'A|R|S' is an error.
10642 if (out_attr[i].int_value() == 0
10643 || (out_attr[i].int_value() == 'S'
10644 && (in_attr[i].int_value() == 'A'
10645 || in_attr[i].int_value() == 'R')))
10646 out_attr[i].set_int_value(in_attr[i].int_value());
10647 else if (in_attr[i].int_value() == 0
10648 || (in_attr[i].int_value() == 'S'
10649 && (out_attr[i].int_value() == 'A'
10650 || out_attr[i].int_value() == 'R')))
10651 ; // Do nothing.
10652 else if (parameters->options().warn_mismatch())
10653 {
10654 gold_error
10655 (_("conflicting architecture profiles %c/%c"),
10656 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10657 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10658 }
10659 }
10660 break;
10661 case elfcpp::Tag_VFP_arch:
10662 {
10663 static const struct
10664 {
10665 int ver;
10666 int regs;
10667 } vfp_versions[7] =
10668 {
10669 {0, 0},
10670 {1, 16},
10671 {2, 16},
10672 {3, 32},
10673 {3, 16},
10674 {4, 32},
10675 {4, 16}
10676 };
10677
10678 // Values greater than 6 aren't defined, so just pick the
10679 // biggest.
10680 if (in_attr[i].int_value() > 6
10681 && in_attr[i].int_value() > out_attr[i].int_value())
10682 {
10683 *out_attr = *in_attr;
10684 break;
10685 }
10686 // The output uses the superset of input features
10687 // (ISA version) and registers.
10688 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10689 vfp_versions[out_attr[i].int_value()].ver);
10690 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10691 vfp_versions[out_attr[i].int_value()].regs);
10692 // This assumes all possible supersets are also a valid
10693 // options.
10694 int newval;
10695 for (newval = 6; newval > 0; newval--)
10696 {
10697 if (regs == vfp_versions[newval].regs
10698 && ver == vfp_versions[newval].ver)
10699 break;
10700 }
10701 out_attr[i].set_int_value(newval);
10702 }
10703 break;
10704 case elfcpp::Tag_PCS_config:
10705 if (out_attr[i].int_value() == 0)
10706 out_attr[i].set_int_value(in_attr[i].int_value());
10707 else if (in_attr[i].int_value() != 0
10708 && out_attr[i].int_value() != 0
10709 && parameters->options().warn_mismatch())
10710 {
10711 // It's sometimes ok to mix different configs, so this is only
10712 // a warning.
10713 gold_warning(_("%s: conflicting platform configuration"), name);
10714 }
10715 break;
10716 case elfcpp::Tag_ABI_PCS_R9_use:
10717 if (in_attr[i].int_value() != out_attr[i].int_value()
10718 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10719 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10720 && parameters->options().warn_mismatch())
10721 {
10722 gold_error(_("%s: conflicting use of R9"), name);
10723 }
10724 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10725 out_attr[i].set_int_value(in_attr[i].int_value());
10726 break;
10727 case elfcpp::Tag_ABI_PCS_RW_data:
10728 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10729 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10730 != elfcpp::AEABI_R9_SB)
10731 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10732 != elfcpp::AEABI_R9_unused)
10733 && parameters->options().warn_mismatch())
10734 {
10735 gold_error(_("%s: SB relative addressing conflicts with use "
10736 "of R9"),
10737 name);
10738 }
10739 // Use the smallest value specified.
10740 if (in_attr[i].int_value() < out_attr[i].int_value())
10741 out_attr[i].set_int_value(in_attr[i].int_value());
10742 break;
10743 case elfcpp::Tag_ABI_PCS_wchar_t:
10744 if (out_attr[i].int_value()
10745 && in_attr[i].int_value()
10746 && out_attr[i].int_value() != in_attr[i].int_value()
10747 && parameters->options().warn_mismatch()
10748 && parameters->options().wchar_size_warning())
10749 {
10750 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10751 "use %u-byte wchar_t; use of wchar_t values "
10752 "across objects may fail"),
10753 name, in_attr[i].int_value(),
10754 out_attr[i].int_value());
10755 }
10756 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10757 out_attr[i].set_int_value(in_attr[i].int_value());
10758 break;
10759 case elfcpp::Tag_ABI_enum_size:
10760 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10761 {
10762 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10763 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10764 {
10765 // The existing object is compatible with anything.
10766 // Use whatever requirements the new object has.
10767 out_attr[i].set_int_value(in_attr[i].int_value());
10768 }
10769 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10770 && out_attr[i].int_value() != in_attr[i].int_value()
10771 && parameters->options().warn_mismatch()
10772 && parameters->options().enum_size_warning())
10773 {
10774 unsigned int in_value = in_attr[i].int_value();
10775 unsigned int out_value = out_attr[i].int_value();
10776 gold_warning(_("%s uses %s enums yet the output is to use "
10777 "%s enums; use of enum values across objects "
10778 "may fail"),
10779 name,
10780 this->aeabi_enum_name(in_value).c_str(),
10781 this->aeabi_enum_name(out_value).c_str());
10782 }
10783 }
10784 break;
10785 case elfcpp::Tag_ABI_VFP_args:
10786 // Already done.
10787 break;
10788 case elfcpp::Tag_ABI_WMMX_args:
10789 if (in_attr[i].int_value() != out_attr[i].int_value()
10790 && parameters->options().warn_mismatch())
10791 {
10792 gold_error(_("%s uses iWMMXt register arguments, output does "
10793 "not"),
10794 name);
10795 }
10796 break;
10797 case Object_attribute::Tag_compatibility:
10798 // Merged in target-independent code.
10799 break;
10800 case elfcpp::Tag_ABI_HardFP_use:
10801 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10802 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10803 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10804 out_attr[i].set_int_value(3);
10805 else if (in_attr[i].int_value() > out_attr[i].int_value())
10806 out_attr[i].set_int_value(in_attr[i].int_value());
10807 break;
10808 case elfcpp::Tag_ABI_FP_16bit_format:
10809 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10810 {
10811 if (in_attr[i].int_value() != out_attr[i].int_value()
10812 && parameters->options().warn_mismatch())
10813 gold_error(_("fp16 format mismatch between %s and output"),
10814 name);
10815 }
10816 if (in_attr[i].int_value() != 0)
10817 out_attr[i].set_int_value(in_attr[i].int_value());
10818 break;
10819
10820 case elfcpp::Tag_DIV_use:
10821 {
10822 // A value of zero on input means that the divide
10823 // instruction may be used if available in the base
10824 // architecture as specified via Tag_CPU_arch and
10825 // Tag_CPU_arch_profile. A value of 1 means that the user
10826 // did not want divide instructions. A value of 2
10827 // explicitly means that divide instructions were allowed
10828 // in ARM and Thumb state.
10829 int arch = this->
10830 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
10831 int_value();
10832 int profile = this->
10833 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
10834 int_value();
10835 if (in_attr[i].int_value() == out_attr[i].int_value())
10836 {
10837 // Do nothing.
10838 }
10839 else if (attributes_forbid_div(&in_attr[i])
10840 && !attributes_accept_div(arch, profile, &out_attr[i]))
10841 out_attr[i].set_int_value(1);
10842 else if (attributes_forbid_div(&out_attr[i])
10843 && attributes_accept_div(arch, profile, &in_attr[i]))
10844 out_attr[i].set_int_value(in_attr[i].int_value());
10845 else if (in_attr[i].int_value() == 2)
10846 out_attr[i].set_int_value(in_attr[i].int_value());
10847 }
10848 break;
10849
10850 case elfcpp::Tag_MPextension_use_legacy:
10851 // We don't output objects with Tag_MPextension_use_legacy - we
10852 // move the value to Tag_MPextension_use.
10853 if (in_attr[i].int_value() != 0
10854 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10855 {
10856 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10857 != in_attr[i].int_value())
10858 {
10859 gold_error(_("%s has has both the current and legacy "
10860 "Tag_MPextension_use attributes"),
10861 name);
10862 }
10863 }
10864
10865 if (in_attr[i].int_value()
10866 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10867 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10868
10869 break;
10870
10871 case elfcpp::Tag_nodefaults:
10872 // This tag is set if it exists, but the value is unused (and is
10873 // typically zero). We don't actually need to do anything here -
10874 // the merge happens automatically when the type flags are merged
10875 // below.
10876 break;
10877 case elfcpp::Tag_also_compatible_with:
10878 // Already done in Tag_CPU_arch.
10879 break;
10880 case elfcpp::Tag_conformance:
10881 // Keep the attribute if it matches. Throw it away otherwise.
10882 // No attribute means no claim to conform.
10883 if (in_attr[i].string_value() != out_attr[i].string_value())
10884 out_attr[i].set_string_value("");
10885 break;
10886
10887 default:
10888 {
10889 const char* err_object = NULL;
10890
10891 // The "known_obj_attributes" table does contain some undefined
10892 // attributes. Ensure that there are unused.
10893 if (out_attr[i].int_value() != 0
10894 || out_attr[i].string_value() != "")
10895 err_object = "output";
10896 else if (in_attr[i].int_value() != 0
10897 || in_attr[i].string_value() != "")
10898 err_object = name;
10899
10900 if (err_object != NULL
10901 && parameters->options().warn_mismatch())
10902 {
10903 // Attribute numbers >=64 (mod 128) can be safely ignored.
10904 if ((i & 127) < 64)
10905 gold_error(_("%s: unknown mandatory EABI object attribute "
10906 "%d"),
10907 err_object, i);
10908 else
10909 gold_warning(_("%s: unknown EABI object attribute %d"),
10910 err_object, i);
10911 }
10912
10913 // Only pass on attributes that match in both inputs.
10914 if (!in_attr[i].matches(out_attr[i]))
10915 {
10916 out_attr[i].set_int_value(0);
10917 out_attr[i].set_string_value("");
10918 }
10919 }
10920 }
10921
10922 // If out_attr was copied from in_attr then it won't have a type yet.
10923 if (in_attr[i].type() && !out_attr[i].type())
10924 out_attr[i].set_type(in_attr[i].type());
10925 }
10926
10927 // Merge Tag_compatibility attributes and any common GNU ones.
10928 this->attributes_section_data_->merge(name, pasd);
10929
10930 // Check for any attributes not known on ARM.
10931 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10932 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10933 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10934 Other_attributes* out_other_attributes =
10935 this->attributes_section_data_->other_attributes(vendor);
10936 Other_attributes::iterator out_iter = out_other_attributes->begin();
10937
10938 while (in_iter != in_other_attributes->end()
10939 || out_iter != out_other_attributes->end())
10940 {
10941 const char* err_object = NULL;
10942 int err_tag = 0;
10943
10944 // The tags for each list are in numerical order.
10945 // If the tags are equal, then merge.
10946 if (out_iter != out_other_attributes->end()
10947 && (in_iter == in_other_attributes->end()
10948 || in_iter->first > out_iter->first))
10949 {
10950 // This attribute only exists in output. We can't merge, and we
10951 // don't know what the tag means, so delete it.
10952 err_object = "output";
10953 err_tag = out_iter->first;
10954 int saved_tag = out_iter->first;
10955 delete out_iter->second;
10956 out_other_attributes->erase(out_iter);
10957 out_iter = out_other_attributes->upper_bound(saved_tag);
10958 }
10959 else if (in_iter != in_other_attributes->end()
10960 && (out_iter != out_other_attributes->end()
10961 || in_iter->first < out_iter->first))
10962 {
10963 // This attribute only exists in input. We can't merge, and we
10964 // don't know what the tag means, so ignore it.
10965 err_object = name;
10966 err_tag = in_iter->first;
10967 ++in_iter;
10968 }
10969 else // The tags are equal.
10970 {
10971 // As present, all attributes in the list are unknown, and
10972 // therefore can't be merged meaningfully.
10973 err_object = "output";
10974 err_tag = out_iter->first;
10975
10976 // Only pass on attributes that match in both inputs.
10977 if (!in_iter->second->matches(*(out_iter->second)))
10978 {
10979 // No match. Delete the attribute.
10980 int saved_tag = out_iter->first;
10981 delete out_iter->second;
10982 out_other_attributes->erase(out_iter);
10983 out_iter = out_other_attributes->upper_bound(saved_tag);
10984 }
10985 else
10986 {
10987 // Matched. Keep the attribute and move to the next.
10988 ++out_iter;
10989 ++in_iter;
10990 }
10991 }
10992
10993 if (err_object && parameters->options().warn_mismatch())
10994 {
10995 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10996 if ((err_tag & 127) < 64)
10997 {
10998 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10999 err_object, err_tag);
11000 }
11001 else
11002 {
11003 gold_warning(_("%s: unknown EABI object attribute %d"),
11004 err_object, err_tag);
11005 }
11006 }
11007 }
11008 }
11009
11010 // Stub-generation methods for Target_arm.
11011
11012 // Make a new Arm_input_section object.
11013
11014 template<bool big_endian>
11015 Arm_input_section<big_endian>*
11016 Target_arm<big_endian>::new_arm_input_section(
11017 Relobj* relobj,
11018 unsigned int shndx)
11019 {
11020 Section_id sid(relobj, shndx);
11021
11022 Arm_input_section<big_endian>* arm_input_section =
11023 new Arm_input_section<big_endian>(relobj, shndx);
11024 arm_input_section->init();
11025
11026 // Register new Arm_input_section in map for look-up.
11027 std::pair<typename Arm_input_section_map::iterator, bool> ins =
11028 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11029
11030 // Make sure that it we have not created another Arm_input_section
11031 // for this input section already.
11032 gold_assert(ins.second);
11033
11034 return arm_input_section;
11035 }
11036
11037 // Find the Arm_input_section object corresponding to the SHNDX-th input
11038 // section of RELOBJ.
11039
11040 template<bool big_endian>
11041 Arm_input_section<big_endian>*
11042 Target_arm<big_endian>::find_arm_input_section(
11043 Relobj* relobj,
11044 unsigned int shndx) const
11045 {
11046 Section_id sid(relobj, shndx);
11047 typename Arm_input_section_map::const_iterator p =
11048 this->arm_input_section_map_.find(sid);
11049 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11050 }
11051
11052 // Make a new stub table.
11053
11054 template<bool big_endian>
11055 Stub_table<big_endian>*
11056 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11057 {
11058 Stub_table<big_endian>* stub_table =
11059 new Stub_table<big_endian>(owner);
11060 this->stub_tables_.push_back(stub_table);
11061
11062 stub_table->set_address(owner->address() + owner->data_size());
11063 stub_table->set_file_offset(owner->offset() + owner->data_size());
11064 stub_table->finalize_data_size();
11065
11066 return stub_table;
11067 }
11068
11069 // Scan a relocation for stub generation.
11070
11071 template<bool big_endian>
11072 void
11073 Target_arm<big_endian>::scan_reloc_for_stub(
11074 const Relocate_info<32, big_endian>* relinfo,
11075 unsigned int r_type,
11076 const Sized_symbol<32>* gsym,
11077 unsigned int r_sym,
11078 const Symbol_value<32>* psymval,
11079 elfcpp::Elf_types<32>::Elf_Swxword addend,
11080 Arm_address address)
11081 {
11082 const Arm_relobj<big_endian>* arm_relobj =
11083 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11084
11085 bool target_is_thumb;
11086 Symbol_value<32> symval;
11087 if (gsym != NULL)
11088 {
11089 // This is a global symbol. Determine if we use PLT and if the
11090 // final target is THUMB.
11091 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11092 {
11093 // This uses a PLT, change the symbol value.
11094 symval.set_output_value(this->plt_section()->address()
11095 + gsym->plt_offset());
11096 psymval = &symval;
11097 target_is_thumb = false;
11098 }
11099 else if (gsym->is_undefined())
11100 // There is no need to generate a stub symbol is undefined.
11101 return;
11102 else
11103 {
11104 target_is_thumb =
11105 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11106 || (gsym->type() == elfcpp::STT_FUNC
11107 && !gsym->is_undefined()
11108 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11109 }
11110 }
11111 else
11112 {
11113 // This is a local symbol. Determine if the final target is THUMB.
11114 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11115 }
11116
11117 // Strip LSB if this points to a THUMB target.
11118 const Arm_reloc_property* reloc_property =
11119 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11120 gold_assert(reloc_property != NULL);
11121 if (target_is_thumb
11122 && reloc_property->uses_thumb_bit()
11123 && ((psymval->value(arm_relobj, 0) & 1) != 0))
11124 {
11125 Arm_address stripped_value =
11126 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11127 symval.set_output_value(stripped_value);
11128 psymval = &symval;
11129 }
11130
11131 // Get the symbol value.
11132 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11133
11134 // Owing to pipelining, the PC relative branches below actually skip
11135 // two instructions when the branch offset is 0.
11136 Arm_address destination;
11137 switch (r_type)
11138 {
11139 case elfcpp::R_ARM_CALL:
11140 case elfcpp::R_ARM_JUMP24:
11141 case elfcpp::R_ARM_PLT32:
11142 // ARM branches.
11143 destination = value + addend + 8;
11144 break;
11145 case elfcpp::R_ARM_THM_CALL:
11146 case elfcpp::R_ARM_THM_XPC22:
11147 case elfcpp::R_ARM_THM_JUMP24:
11148 case elfcpp::R_ARM_THM_JUMP19:
11149 // THUMB branches.
11150 destination = value + addend + 4;
11151 break;
11152 default:
11153 gold_unreachable();
11154 }
11155
11156 Reloc_stub* stub = NULL;
11157 Stub_type stub_type =
11158 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11159 target_is_thumb);
11160 if (stub_type != arm_stub_none)
11161 {
11162 // Try looking up an existing stub from a stub table.
11163 Stub_table<big_endian>* stub_table =
11164 arm_relobj->stub_table(relinfo->data_shndx);
11165 gold_assert(stub_table != NULL);
11166
11167 // Locate stub by destination.
11168 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11169
11170 // Create a stub if there is not one already
11171 stub = stub_table->find_reloc_stub(stub_key);
11172 if (stub == NULL)
11173 {
11174 // create a new stub and add it to stub table.
11175 stub = this->stub_factory().make_reloc_stub(stub_type);
11176 stub_table->add_reloc_stub(stub, stub_key);
11177 }
11178
11179 // Record the destination address.
11180 stub->set_destination_address(destination
11181 | (target_is_thumb ? 1 : 0));
11182 }
11183
11184 // For Cortex-A8, we need to record a relocation at 4K page boundary.
11185 if (this->fix_cortex_a8_
11186 && (r_type == elfcpp::R_ARM_THM_JUMP24
11187 || r_type == elfcpp::R_ARM_THM_JUMP19
11188 || r_type == elfcpp::R_ARM_THM_CALL
11189 || r_type == elfcpp::R_ARM_THM_XPC22)
11190 && (address & 0xfffU) == 0xffeU)
11191 {
11192 // Found a candidate. Note we haven't checked the destination is
11193 // within 4K here: if we do so (and don't create a record) we can't
11194 // tell that a branch should have been relocated when scanning later.
11195 this->cortex_a8_relocs_info_[address] =
11196 new Cortex_a8_reloc(stub, r_type,
11197 destination | (target_is_thumb ? 1 : 0));
11198 }
11199 }
11200
11201 // This function scans a relocation sections for stub generation.
11202 // The template parameter Relocate must be a class type which provides
11203 // a single function, relocate(), which implements the machine
11204 // specific part of a relocation.
11205
11206 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11207 // SHT_REL or SHT_RELA.
11208
11209 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11210 // of relocs. OUTPUT_SECTION is the output section.
11211 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11212 // mapped to output offsets.
11213
11214 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11215 // VIEW_SIZE is the size. These refer to the input section, unless
11216 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11217 // the output section.
11218
11219 template<bool big_endian>
11220 template<int sh_type>
11221 void inline
11222 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11223 const Relocate_info<32, big_endian>* relinfo,
11224 const unsigned char* prelocs,
11225 size_t reloc_count,
11226 Output_section* output_section,
11227 bool needs_special_offset_handling,
11228 const unsigned char* view,
11229 elfcpp::Elf_types<32>::Elf_Addr view_address,
11230 section_size_type)
11231 {
11232 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11233 const int reloc_size =
11234 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11235
11236 Arm_relobj<big_endian>* arm_object =
11237 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11238 unsigned int local_count = arm_object->local_symbol_count();
11239
11240 gold::Default_comdat_behavior default_comdat_behavior;
11241 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11242
11243 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11244 {
11245 Reltype reloc(prelocs);
11246
11247 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11248 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11249 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11250
11251 r_type = this->get_real_reloc_type(r_type);
11252
11253 // Only a few relocation types need stubs.
11254 if ((r_type != elfcpp::R_ARM_CALL)
11255 && (r_type != elfcpp::R_ARM_JUMP24)
11256 && (r_type != elfcpp::R_ARM_PLT32)
11257 && (r_type != elfcpp::R_ARM_THM_CALL)
11258 && (r_type != elfcpp::R_ARM_THM_XPC22)
11259 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11260 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11261 && (r_type != elfcpp::R_ARM_V4BX))
11262 continue;
11263
11264 section_offset_type offset =
11265 convert_to_section_size_type(reloc.get_r_offset());
11266
11267 if (needs_special_offset_handling)
11268 {
11269 offset = output_section->output_offset(relinfo->object,
11270 relinfo->data_shndx,
11271 offset);
11272 if (offset == -1)
11273 continue;
11274 }
11275
11276 // Create a v4bx stub if --fix-v4bx-interworking is used.
11277 if (r_type == elfcpp::R_ARM_V4BX)
11278 {
11279 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11280 {
11281 // Get the BX instruction.
11282 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11283 const Valtype* wv =
11284 reinterpret_cast<const Valtype*>(view + offset);
11285 elfcpp::Elf_types<32>::Elf_Swxword insn =
11286 elfcpp::Swap<32, big_endian>::readval(wv);
11287 const uint32_t reg = (insn & 0xf);
11288
11289 if (reg < 0xf)
11290 {
11291 // Try looking up an existing stub from a stub table.
11292 Stub_table<big_endian>* stub_table =
11293 arm_object->stub_table(relinfo->data_shndx);
11294 gold_assert(stub_table != NULL);
11295
11296 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11297 {
11298 // create a new stub and add it to stub table.
11299 Arm_v4bx_stub* stub =
11300 this->stub_factory().make_arm_v4bx_stub(reg);
11301 gold_assert(stub != NULL);
11302 stub_table->add_arm_v4bx_stub(stub);
11303 }
11304 }
11305 }
11306 continue;
11307 }
11308
11309 // Get the addend.
11310 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11311 elfcpp::Elf_types<32>::Elf_Swxword addend =
11312 stub_addend_reader(r_type, view + offset, reloc);
11313
11314 const Sized_symbol<32>* sym;
11315
11316 Symbol_value<32> symval;
11317 const Symbol_value<32> *psymval;
11318 bool is_defined_in_discarded_section;
11319 unsigned int shndx;
11320 if (r_sym < local_count)
11321 {
11322 sym = NULL;
11323 psymval = arm_object->local_symbol(r_sym);
11324
11325 // If the local symbol belongs to a section we are discarding,
11326 // and that section is a debug section, try to find the
11327 // corresponding kept section and map this symbol to its
11328 // counterpart in the kept section. The symbol must not
11329 // correspond to a section we are folding.
11330 bool is_ordinary;
11331 shndx = psymval->input_shndx(&is_ordinary);
11332 is_defined_in_discarded_section =
11333 (is_ordinary
11334 && shndx != elfcpp::SHN_UNDEF
11335 && !arm_object->is_section_included(shndx)
11336 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11337
11338 // We need to compute the would-be final value of this local
11339 // symbol.
11340 if (!is_defined_in_discarded_section)
11341 {
11342 typedef Sized_relobj_file<32, big_endian> ObjType;
11343 typename ObjType::Compute_final_local_value_status status =
11344 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11345 relinfo->symtab);
11346 if (status == ObjType::CFLV_OK)
11347 {
11348 // Currently we cannot handle a branch to a target in
11349 // a merged section. If this is the case, issue an error
11350 // and also free the merge symbol value.
11351 if (!symval.has_output_value())
11352 {
11353 const std::string& section_name =
11354 arm_object->section_name(shndx);
11355 arm_object->error(_("cannot handle branch to local %u "
11356 "in a merged section %s"),
11357 r_sym, section_name.c_str());
11358 }
11359 psymval = &symval;
11360 }
11361 else
11362 {
11363 // We cannot determine the final value.
11364 continue;
11365 }
11366 }
11367 }
11368 else
11369 {
11370 const Symbol* gsym;
11371 gsym = arm_object->global_symbol(r_sym);
11372 gold_assert(gsym != NULL);
11373 if (gsym->is_forwarder())
11374 gsym = relinfo->symtab->resolve_forwards(gsym);
11375
11376 sym = static_cast<const Sized_symbol<32>*>(gsym);
11377 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11378 symval.set_output_symtab_index(sym->symtab_index());
11379 else
11380 symval.set_no_output_symtab_entry();
11381
11382 // We need to compute the would-be final value of this global
11383 // symbol.
11384 const Symbol_table* symtab = relinfo->symtab;
11385 const Sized_symbol<32>* sized_symbol =
11386 symtab->get_sized_symbol<32>(gsym);
11387 Symbol_table::Compute_final_value_status status;
11388 Arm_address value =
11389 symtab->compute_final_value<32>(sized_symbol, &status);
11390
11391 // Skip this if the symbol has not output section.
11392 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11393 continue;
11394 symval.set_output_value(value);
11395
11396 if (gsym->type() == elfcpp::STT_TLS)
11397 symval.set_is_tls_symbol();
11398 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11399 symval.set_is_ifunc_symbol();
11400 psymval = &symval;
11401
11402 is_defined_in_discarded_section =
11403 (gsym->is_defined_in_discarded_section()
11404 && gsym->is_undefined());
11405 shndx = 0;
11406 }
11407
11408 Symbol_value<32> symval2;
11409 if (is_defined_in_discarded_section)
11410 {
11411 if (comdat_behavior == CB_UNDETERMINED)
11412 {
11413 std::string name = arm_object->section_name(relinfo->data_shndx);
11414 comdat_behavior = default_comdat_behavior.get(name.c_str());
11415 }
11416 if (comdat_behavior == CB_PRETEND)
11417 {
11418 // FIXME: This case does not work for global symbols.
11419 // We have no place to store the original section index.
11420 // Fortunately this does not matter for comdat sections,
11421 // only for sections explicitly discarded by a linker
11422 // script.
11423 bool found;
11424 typename elfcpp::Elf_types<32>::Elf_Addr value =
11425 arm_object->map_to_kept_section(shndx, &found);
11426 if (found)
11427 symval2.set_output_value(value + psymval->input_value());
11428 else
11429 symval2.set_output_value(0);
11430 }
11431 else
11432 {
11433 if (comdat_behavior == CB_WARNING)
11434 gold_warning_at_location(relinfo, i, offset,
11435 _("relocation refers to discarded "
11436 "section"));
11437 symval2.set_output_value(0);
11438 }
11439 symval2.set_no_output_symtab_entry();
11440 psymval = &symval2;
11441 }
11442
11443 // If symbol is a section symbol, we don't know the actual type of
11444 // destination. Give up.
11445 if (psymval->is_section_symbol())
11446 continue;
11447
11448 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11449 addend, view_address + offset);
11450 }
11451 }
11452
11453 // Scan an input section for stub generation.
11454
11455 template<bool big_endian>
11456 void
11457 Target_arm<big_endian>::scan_section_for_stubs(
11458 const Relocate_info<32, big_endian>* relinfo,
11459 unsigned int sh_type,
11460 const unsigned char* prelocs,
11461 size_t reloc_count,
11462 Output_section* output_section,
11463 bool needs_special_offset_handling,
11464 const unsigned char* view,
11465 Arm_address view_address,
11466 section_size_type view_size)
11467 {
11468 if (sh_type == elfcpp::SHT_REL)
11469 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11470 relinfo,
11471 prelocs,
11472 reloc_count,
11473 output_section,
11474 needs_special_offset_handling,
11475 view,
11476 view_address,
11477 view_size);
11478 else if (sh_type == elfcpp::SHT_RELA)
11479 // We do not support RELA type relocations yet. This is provided for
11480 // completeness.
11481 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11482 relinfo,
11483 prelocs,
11484 reloc_count,
11485 output_section,
11486 needs_special_offset_handling,
11487 view,
11488 view_address,
11489 view_size);
11490 else
11491 gold_unreachable();
11492 }
11493
11494 // Group input sections for stub generation.
11495 //
11496 // We group input sections in an output section so that the total size,
11497 // including any padding space due to alignment is smaller than GROUP_SIZE
11498 // unless the only input section in group is bigger than GROUP_SIZE already.
11499 // Then an ARM stub table is created to follow the last input section
11500 // in group. For each group an ARM stub table is created an is placed
11501 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
11502 // extend the group after the stub table.
11503
11504 template<bool big_endian>
11505 void
11506 Target_arm<big_endian>::group_sections(
11507 Layout* layout,
11508 section_size_type group_size,
11509 bool stubs_always_after_branch,
11510 const Task* task)
11511 {
11512 // Group input sections and insert stub table
11513 Layout::Section_list section_list;
11514 layout->get_executable_sections(&section_list);
11515 for (Layout::Section_list::const_iterator p = section_list.begin();
11516 p != section_list.end();
11517 ++p)
11518 {
11519 Arm_output_section<big_endian>* output_section =
11520 Arm_output_section<big_endian>::as_arm_output_section(*p);
11521 output_section->group_sections(group_size, stubs_always_after_branch,
11522 this, task);
11523 }
11524 }
11525
11526 // Relaxation hook. This is where we do stub generation.
11527
11528 template<bool big_endian>
11529 bool
11530 Target_arm<big_endian>::do_relax(
11531 int pass,
11532 const Input_objects* input_objects,
11533 Symbol_table* symtab,
11534 Layout* layout,
11535 const Task* task)
11536 {
11537 // No need to generate stubs if this is a relocatable link.
11538 gold_assert(!parameters->options().relocatable());
11539
11540 // If this is the first pass, we need to group input sections into
11541 // stub groups.
11542 bool done_exidx_fixup = false;
11543 typedef typename Stub_table_list::iterator Stub_table_iterator;
11544 if (pass == 1)
11545 {
11546 // Determine the stub group size. The group size is the absolute
11547 // value of the parameter --stub-group-size. If --stub-group-size
11548 // is passed a negative value, we restrict stubs to be always after
11549 // the stubbed branches.
11550 int32_t stub_group_size_param =
11551 parameters->options().stub_group_size();
11552 bool stubs_always_after_branch = stub_group_size_param < 0;
11553 section_size_type stub_group_size = abs(stub_group_size_param);
11554
11555 if (stub_group_size == 1)
11556 {
11557 // Default value.
11558 // Thumb branch range is +-4MB has to be used as the default
11559 // maximum size (a given section can contain both ARM and Thumb
11560 // code, so the worst case has to be taken into account). If we are
11561 // fixing cortex-a8 errata, the branch range has to be even smaller,
11562 // since wide conditional branch has a range of +-1MB only.
11563 //
11564 // This value is 48K less than that, which allows for 4096
11565 // 12-byte stubs. If we exceed that, then we will fail to link.
11566 // The user will have to relink with an explicit group size
11567 // option.
11568 stub_group_size = 4145152;
11569 }
11570
11571 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11572 // page as the first half of a 32-bit branch straddling two 4K pages.
11573 // This is a crude way of enforcing that. In addition, long conditional
11574 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11575 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11576 // cortex-A8 stubs from long conditional branches.
11577 if (this->fix_cortex_a8_)
11578 {
11579 stubs_always_after_branch = true;
11580 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11581 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11582 }
11583
11584 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11585
11586 // Also fix .ARM.exidx section coverage.
11587 Arm_output_section<big_endian>* exidx_output_section = NULL;
11588 for (Layout::Section_list::const_iterator p =
11589 layout->section_list().begin();
11590 p != layout->section_list().end();
11591 ++p)
11592 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11593 {
11594 if (exidx_output_section == NULL)
11595 exidx_output_section =
11596 Arm_output_section<big_endian>::as_arm_output_section(*p);
11597 else
11598 // We cannot handle this now.
11599 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11600 "non-relocatable link"),
11601 exidx_output_section->name(),
11602 (*p)->name());
11603 }
11604
11605 if (exidx_output_section != NULL)
11606 {
11607 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11608 symtab, task);
11609 done_exidx_fixup = true;
11610 }
11611 }
11612 else
11613 {
11614 // If this is not the first pass, addresses and file offsets have
11615 // been reset at this point, set them here.
11616 for (Stub_table_iterator sp = this->stub_tables_.begin();
11617 sp != this->stub_tables_.end();
11618 ++sp)
11619 {
11620 Arm_input_section<big_endian>* owner = (*sp)->owner();
11621 off_t off = align_address(owner->original_size(),
11622 (*sp)->addralign());
11623 (*sp)->set_address_and_file_offset(owner->address() + off,
11624 owner->offset() + off);
11625 }
11626 }
11627
11628 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11629 // beginning of each relaxation pass, just blow away all the stubs.
11630 // Alternatively, we could selectively remove only the stubs and reloc
11631 // information for code sections that have moved since the last pass.
11632 // That would require more book-keeping.
11633 if (this->fix_cortex_a8_)
11634 {
11635 // Clear all Cortex-A8 reloc information.
11636 for (typename Cortex_a8_relocs_info::const_iterator p =
11637 this->cortex_a8_relocs_info_.begin();
11638 p != this->cortex_a8_relocs_info_.end();
11639 ++p)
11640 delete p->second;
11641 this->cortex_a8_relocs_info_.clear();
11642
11643 // Remove all Cortex-A8 stubs.
11644 for (Stub_table_iterator sp = this->stub_tables_.begin();
11645 sp != this->stub_tables_.end();
11646 ++sp)
11647 (*sp)->remove_all_cortex_a8_stubs();
11648 }
11649
11650 // Scan relocs for relocation stubs
11651 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11652 op != input_objects->relobj_end();
11653 ++op)
11654 {
11655 Arm_relobj<big_endian>* arm_relobj =
11656 Arm_relobj<big_endian>::as_arm_relobj(*op);
11657 // Lock the object so we can read from it. This is only called
11658 // single-threaded from Layout::finalize, so it is OK to lock.
11659 Task_lock_obj<Object> tl(task, arm_relobj);
11660 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11661 }
11662
11663 // Check all stub tables to see if any of them have their data sizes
11664 // or addresses alignments changed. These are the only things that
11665 // matter.
11666 bool any_stub_table_changed = false;
11667 Unordered_set<const Output_section*> sections_needing_adjustment;
11668 for (Stub_table_iterator sp = this->stub_tables_.begin();
11669 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11670 ++sp)
11671 {
11672 if ((*sp)->update_data_size_and_addralign())
11673 {
11674 // Update data size of stub table owner.
11675 Arm_input_section<big_endian>* owner = (*sp)->owner();
11676 uint64_t address = owner->address();
11677 off_t offset = owner->offset();
11678 owner->reset_address_and_file_offset();
11679 owner->set_address_and_file_offset(address, offset);
11680
11681 sections_needing_adjustment.insert(owner->output_section());
11682 any_stub_table_changed = true;
11683 }
11684 }
11685
11686 // Output_section_data::output_section() returns a const pointer but we
11687 // need to update output sections, so we record all output sections needing
11688 // update above and scan the sections here to find out what sections need
11689 // to be updated.
11690 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11691 p != layout->section_list().end();
11692 ++p)
11693 {
11694 if (sections_needing_adjustment.find(*p)
11695 != sections_needing_adjustment.end())
11696 (*p)->set_section_offsets_need_adjustment();
11697 }
11698
11699 // Stop relaxation if no EXIDX fix-up and no stub table change.
11700 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11701
11702 // Finalize the stubs in the last relaxation pass.
11703 if (!continue_relaxation)
11704 {
11705 for (Stub_table_iterator sp = this->stub_tables_.begin();
11706 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11707 ++sp)
11708 (*sp)->finalize_stubs();
11709
11710 // Update output local symbol counts of objects if necessary.
11711 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11712 op != input_objects->relobj_end();
11713 ++op)
11714 {
11715 Arm_relobj<big_endian>* arm_relobj =
11716 Arm_relobj<big_endian>::as_arm_relobj(*op);
11717
11718 // Update output local symbol counts. We need to discard local
11719 // symbols defined in parts of input sections that are discarded by
11720 // relaxation.
11721 if (arm_relobj->output_local_symbol_count_needs_update())
11722 {
11723 // We need to lock the object's file to update it.
11724 Task_lock_obj<Object> tl(task, arm_relobj);
11725 arm_relobj->update_output_local_symbol_count();
11726 }
11727 }
11728 }
11729
11730 return continue_relaxation;
11731 }
11732
11733 // Relocate a stub.
11734
11735 template<bool big_endian>
11736 void
11737 Target_arm<big_endian>::relocate_stub(
11738 Stub* stub,
11739 const Relocate_info<32, big_endian>* relinfo,
11740 Output_section* output_section,
11741 unsigned char* view,
11742 Arm_address address,
11743 section_size_type view_size)
11744 {
11745 Relocate relocate;
11746 const Stub_template* stub_template = stub->stub_template();
11747 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11748 {
11749 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11750 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11751
11752 unsigned int r_type = insn->r_type();
11753 section_size_type reloc_offset = stub_template->reloc_offset(i);
11754 section_size_type reloc_size = insn->size();
11755 gold_assert(reloc_offset + reloc_size <= view_size);
11756
11757 // This is the address of the stub destination.
11758 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11759 Symbol_value<32> symval;
11760 symval.set_output_value(target);
11761
11762 // Synthesize a fake reloc just in case. We don't have a symbol so
11763 // we use 0.
11764 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11765 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11766 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11767 reloc_write.put_r_offset(reloc_offset);
11768 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11769 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11770
11771 relocate.relocate(relinfo, this, output_section,
11772 this->fake_relnum_for_stubs, rel, r_type,
11773 NULL, &symval, view + reloc_offset,
11774 address + reloc_offset, reloc_size);
11775 }
11776 }
11777
11778 // Determine whether an object attribute tag takes an integer, a
11779 // string or both.
11780
11781 template<bool big_endian>
11782 int
11783 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11784 {
11785 if (tag == Object_attribute::Tag_compatibility)
11786 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11787 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11788 else if (tag == elfcpp::Tag_nodefaults)
11789 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11790 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11791 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11792 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11793 else if (tag < 32)
11794 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11795 else
11796 return ((tag & 1) != 0
11797 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11798 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11799 }
11800
11801 // Reorder attributes.
11802 //
11803 // The ABI defines that Tag_conformance should be emitted first, and that
11804 // Tag_nodefaults should be second (if either is defined). This sets those
11805 // two positions, and bumps up the position of all the remaining tags to
11806 // compensate.
11807
11808 template<bool big_endian>
11809 int
11810 Target_arm<big_endian>::do_attributes_order(int num) const
11811 {
11812 // Reorder the known object attributes in output. We want to move
11813 // Tag_conformance to position 4 and Tag_conformance to position 5
11814 // and shift everything between 4 .. Tag_conformance - 1 to make room.
11815 if (num == 4)
11816 return elfcpp::Tag_conformance;
11817 if (num == 5)
11818 return elfcpp::Tag_nodefaults;
11819 if ((num - 2) < elfcpp::Tag_nodefaults)
11820 return num - 2;
11821 if ((num - 1) < elfcpp::Tag_conformance)
11822 return num - 1;
11823 return num;
11824 }
11825
11826 // Scan a span of THUMB code for Cortex-A8 erratum.
11827
11828 template<bool big_endian>
11829 void
11830 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11831 Arm_relobj<big_endian>* arm_relobj,
11832 unsigned int shndx,
11833 section_size_type span_start,
11834 section_size_type span_end,
11835 const unsigned char* view,
11836 Arm_address address)
11837 {
11838 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11839 //
11840 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11841 // The branch target is in the same 4KB region as the
11842 // first half of the branch.
11843 // The instruction before the branch is a 32-bit
11844 // length non-branch instruction.
11845 section_size_type i = span_start;
11846 bool last_was_32bit = false;
11847 bool last_was_branch = false;
11848 while (i < span_end)
11849 {
11850 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11851 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11852 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11853 bool is_blx = false, is_b = false;
11854 bool is_bl = false, is_bcc = false;
11855
11856 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11857 if (insn_32bit)
11858 {
11859 // Load the rest of the insn (in manual-friendly order).
11860 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11861
11862 // Encoding T4: B<c>.W.
11863 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11864 // Encoding T1: BL<c>.W.
11865 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11866 // Encoding T2: BLX<c>.W.
11867 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11868 // Encoding T3: B<c>.W (not permitted in IT block).
11869 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11870 && (insn & 0x07f00000U) != 0x03800000U);
11871 }
11872
11873 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11874
11875 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11876 // page boundary and it follows 32-bit non-branch instruction,
11877 // we need to work around.
11878 if (is_32bit_branch
11879 && ((address + i) & 0xfffU) == 0xffeU
11880 && last_was_32bit
11881 && !last_was_branch)
11882 {
11883 // Check to see if there is a relocation stub for this branch.
11884 bool force_target_arm = false;
11885 bool force_target_thumb = false;
11886 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11887 Cortex_a8_relocs_info::const_iterator p =
11888 this->cortex_a8_relocs_info_.find(address + i);
11889
11890 if (p != this->cortex_a8_relocs_info_.end())
11891 {
11892 cortex_a8_reloc = p->second;
11893 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11894
11895 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11896 && !target_is_thumb)
11897 force_target_arm = true;
11898 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11899 && target_is_thumb)
11900 force_target_thumb = true;
11901 }
11902
11903 off_t offset;
11904 Stub_type stub_type = arm_stub_none;
11905
11906 // Check if we have an offending branch instruction.
11907 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11908 uint16_t lower_insn = insn & 0xffffU;
11909 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11910
11911 if (cortex_a8_reloc != NULL
11912 && cortex_a8_reloc->reloc_stub() != NULL)
11913 // We've already made a stub for this instruction, e.g.
11914 // it's a long branch or a Thumb->ARM stub. Assume that
11915 // stub will suffice to work around the A8 erratum (see
11916 // setting of always_after_branch above).
11917 ;
11918 else if (is_bcc)
11919 {
11920 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11921 lower_insn);
11922 stub_type = arm_stub_a8_veneer_b_cond;
11923 }
11924 else if (is_b || is_bl || is_blx)
11925 {
11926 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11927 lower_insn);
11928 if (is_blx)
11929 offset &= ~3;
11930
11931 stub_type = (is_blx
11932 ? arm_stub_a8_veneer_blx
11933 : (is_bl
11934 ? arm_stub_a8_veneer_bl
11935 : arm_stub_a8_veneer_b));
11936 }
11937
11938 if (stub_type != arm_stub_none)
11939 {
11940 Arm_address pc_for_insn = address + i + 4;
11941
11942 // The original instruction is a BL, but the target is
11943 // an ARM instruction. If we were not making a stub,
11944 // the BL would have been converted to a BLX. Use the
11945 // BLX stub instead in that case.
11946 if (this->may_use_v5t_interworking() && force_target_arm
11947 && stub_type == arm_stub_a8_veneer_bl)
11948 {
11949 stub_type = arm_stub_a8_veneer_blx;
11950 is_blx = true;
11951 is_bl = false;
11952 }
11953 // Conversely, if the original instruction was
11954 // BLX but the target is Thumb mode, use the BL stub.
11955 else if (force_target_thumb
11956 && stub_type == arm_stub_a8_veneer_blx)
11957 {
11958 stub_type = arm_stub_a8_veneer_bl;
11959 is_blx = false;
11960 is_bl = true;
11961 }
11962
11963 if (is_blx)
11964 pc_for_insn &= ~3;
11965
11966 // If we found a relocation, use the proper destination,
11967 // not the offset in the (unrelocated) instruction.
11968 // Note this is always done if we switched the stub type above.
11969 if (cortex_a8_reloc != NULL)
11970 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11971
11972 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11973
11974 // Add a new stub if destination address in in the same page.
11975 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11976 {
11977 Cortex_a8_stub* stub =
11978 this->stub_factory_.make_cortex_a8_stub(stub_type,
11979 arm_relobj, shndx,
11980 address + i,
11981 target, insn);
11982 Stub_table<big_endian>* stub_table =
11983 arm_relobj->stub_table(shndx);
11984 gold_assert(stub_table != NULL);
11985 stub_table->add_cortex_a8_stub(address + i, stub);
11986 }
11987 }
11988 }
11989
11990 i += insn_32bit ? 4 : 2;
11991 last_was_32bit = insn_32bit;
11992 last_was_branch = is_32bit_branch;
11993 }
11994 }
11995
11996 // Apply the Cortex-A8 workaround.
11997
11998 template<bool big_endian>
11999 void
12000 Target_arm<big_endian>::apply_cortex_a8_workaround(
12001 const Cortex_a8_stub* stub,
12002 Arm_address stub_address,
12003 unsigned char* insn_view,
12004 Arm_address insn_address)
12005 {
12006 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
12007 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12008 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12009 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12010 off_t branch_offset = stub_address - (insn_address + 4);
12011
12012 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12013 switch (stub->stub_template()->type())
12014 {
12015 case arm_stub_a8_veneer_b_cond:
12016 // For a conditional branch, we re-write it to be an unconditional
12017 // branch to the stub. We use the THUMB-2 encoding here.
12018 upper_insn = 0xf000U;
12019 lower_insn = 0xb800U;
12020 // Fall through
12021 case arm_stub_a8_veneer_b:
12022 case arm_stub_a8_veneer_bl:
12023 case arm_stub_a8_veneer_blx:
12024 if ((lower_insn & 0x5000U) == 0x4000U)
12025 // For a BLX instruction, make sure that the relocation is
12026 // rounded up to a word boundary. This follows the semantics of
12027 // the instruction which specifies that bit 1 of the target
12028 // address will come from bit 1 of the base address.
12029 branch_offset = (branch_offset + 2) & ~3;
12030
12031 // Put BRANCH_OFFSET back into the insn.
12032 gold_assert(!Bits<25>::has_overflow32(branch_offset));
12033 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12034 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12035 break;
12036
12037 default:
12038 gold_unreachable();
12039 }
12040
12041 // Put the relocated value back in the object file:
12042 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12043 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12044 }
12045
12046 // Target selector for ARM. Note this is never instantiated directly.
12047 // It's only used in Target_selector_arm_nacl, below.
12048
12049 template<bool big_endian>
12050 class Target_selector_arm : public Target_selector
12051 {
12052 public:
12053 Target_selector_arm()
12054 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12055 (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12056 (big_endian ? "armelfb" : "armelf"))
12057 { }
12058
12059 Target*
12060 do_instantiate_target()
12061 { return new Target_arm<big_endian>(); }
12062 };
12063
12064 // Fix .ARM.exidx section coverage.
12065
12066 template<bool big_endian>
12067 void
12068 Target_arm<big_endian>::fix_exidx_coverage(
12069 Layout* layout,
12070 const Input_objects* input_objects,
12071 Arm_output_section<big_endian>* exidx_section,
12072 Symbol_table* symtab,
12073 const Task* task)
12074 {
12075 // We need to look at all the input sections in output in ascending
12076 // order of of output address. We do that by building a sorted list
12077 // of output sections by addresses. Then we looks at the output sections
12078 // in order. The input sections in an output section are already sorted
12079 // by addresses within the output section.
12080
12081 typedef std::set<Output_section*, output_section_address_less_than>
12082 Sorted_output_section_list;
12083 Sorted_output_section_list sorted_output_sections;
12084
12085 // Find out all the output sections of input sections pointed by
12086 // EXIDX input sections.
12087 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12088 p != input_objects->relobj_end();
12089 ++p)
12090 {
12091 Arm_relobj<big_endian>* arm_relobj =
12092 Arm_relobj<big_endian>::as_arm_relobj(*p);
12093 std::vector<unsigned int> shndx_list;
12094 arm_relobj->get_exidx_shndx_list(&shndx_list);
12095 for (size_t i = 0; i < shndx_list.size(); ++i)
12096 {
12097 const Arm_exidx_input_section* exidx_input_section =
12098 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12099 gold_assert(exidx_input_section != NULL);
12100 if (!exidx_input_section->has_errors())
12101 {
12102 unsigned int text_shndx = exidx_input_section->link();
12103 Output_section* os = arm_relobj->output_section(text_shndx);
12104 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12105 sorted_output_sections.insert(os);
12106 }
12107 }
12108 }
12109
12110 // Go over the output sections in ascending order of output addresses.
12111 typedef typename Arm_output_section<big_endian>::Text_section_list
12112 Text_section_list;
12113 Text_section_list sorted_text_sections;
12114 for (typename Sorted_output_section_list::iterator p =
12115 sorted_output_sections.begin();
12116 p != sorted_output_sections.end();
12117 ++p)
12118 {
12119 Arm_output_section<big_endian>* arm_output_section =
12120 Arm_output_section<big_endian>::as_arm_output_section(*p);
12121 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12122 }
12123
12124 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12125 merge_exidx_entries(), task);
12126 }
12127
12128 template<bool big_endian>
12129 void
12130 Target_arm<big_endian>::do_define_standard_symbols(
12131 Symbol_table* symtab,
12132 Layout* layout)
12133 {
12134 // Handle the .ARM.exidx section.
12135 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12136
12137 if (exidx_section != NULL)
12138 {
12139 // Create __exidx_start and __exidx_end symbols.
12140 symtab->define_in_output_data("__exidx_start",
12141 NULL, // version
12142 Symbol_table::PREDEFINED,
12143 exidx_section,
12144 0, // value
12145 0, // symsize
12146 elfcpp::STT_NOTYPE,
12147 elfcpp::STB_GLOBAL,
12148 elfcpp::STV_HIDDEN,
12149 0, // nonvis
12150 false, // offset_is_from_end
12151 true); // only_if_ref
12152
12153 symtab->define_in_output_data("__exidx_end",
12154 NULL, // version
12155 Symbol_table::PREDEFINED,
12156 exidx_section,
12157 0, // value
12158 0, // symsize
12159 elfcpp::STT_NOTYPE,
12160 elfcpp::STB_GLOBAL,
12161 elfcpp::STV_HIDDEN,
12162 0, // nonvis
12163 true, // offset_is_from_end
12164 true); // only_if_ref
12165 }
12166 else
12167 {
12168 // Define __exidx_start and __exidx_end even when .ARM.exidx
12169 // section is missing to match ld's behaviour.
12170 symtab->define_as_constant("__exidx_start", NULL,
12171 Symbol_table::PREDEFINED,
12172 0, 0, elfcpp::STT_OBJECT,
12173 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12174 true, false);
12175 symtab->define_as_constant("__exidx_end", NULL,
12176 Symbol_table::PREDEFINED,
12177 0, 0, elfcpp::STT_OBJECT,
12178 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12179 true, false);
12180 }
12181 }
12182
12183 // NaCl variant. It uses different PLT contents.
12184
12185 template<bool big_endian>
12186 class Output_data_plt_arm_nacl;
12187
12188 template<bool big_endian>
12189 class Target_arm_nacl : public Target_arm<big_endian>
12190 {
12191 public:
12192 Target_arm_nacl()
12193 : Target_arm<big_endian>(&arm_nacl_info)
12194 { }
12195
12196 protected:
12197 virtual Output_data_plt_arm<big_endian>*
12198 do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12199 { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12200
12201 private:
12202 static const Target::Target_info arm_nacl_info;
12203 };
12204
12205 template<bool big_endian>
12206 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12207 {
12208 32, // size
12209 big_endian, // is_big_endian
12210 elfcpp::EM_ARM, // machine_code
12211 false, // has_make_symbol
12212 false, // has_resolve
12213 false, // has_code_fill
12214 true, // is_default_stack_executable
12215 false, // can_icf_inline_merge_sections
12216 '\0', // wrap_char
12217 "/lib/ld-nacl-arm.so.1", // dynamic_linker
12218 0x20000, // default_text_segment_address
12219 0x10000, // abi_pagesize (overridable by -z max-page-size)
12220 0x10000, // common_pagesize (overridable by -z common-page-size)
12221 true, // isolate_execinstr
12222 0x10000000, // rosegment_gap
12223 elfcpp::SHN_UNDEF, // small_common_shndx
12224 elfcpp::SHN_UNDEF, // large_common_shndx
12225 0, // small_common_section_flags
12226 0, // large_common_section_flags
12227 ".ARM.attributes", // attributes_section
12228 "aeabi", // attributes_vendor
12229 "_start" // entry_symbol_name
12230 };
12231
12232 template<bool big_endian>
12233 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12234 {
12235 public:
12236 Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12237 : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12238 { }
12239
12240 protected:
12241 // Return the offset of the first non-reserved PLT entry.
12242 virtual unsigned int
12243 do_first_plt_entry_offset() const
12244 { return sizeof(first_plt_entry); }
12245
12246 // Return the size of a PLT entry.
12247 virtual unsigned int
12248 do_get_plt_entry_size() const
12249 { return sizeof(plt_entry); }
12250
12251 virtual void
12252 do_fill_first_plt_entry(unsigned char* pov,
12253 Arm_address got_address,
12254 Arm_address plt_address);
12255
12256 virtual void
12257 do_fill_plt_entry(unsigned char* pov,
12258 Arm_address got_address,
12259 Arm_address plt_address,
12260 unsigned int got_offset,
12261 unsigned int plt_offset);
12262
12263 private:
12264 inline uint32_t arm_movw_immediate(uint32_t value)
12265 {
12266 return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12267 }
12268
12269 inline uint32_t arm_movt_immediate(uint32_t value)
12270 {
12271 return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12272 }
12273
12274 // Template for the first PLT entry.
12275 static const uint32_t first_plt_entry[16];
12276
12277 // Template for subsequent PLT entries.
12278 static const uint32_t plt_entry[4];
12279 };
12280
12281 // The first entry in the PLT.
12282 template<bool big_endian>
12283 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12284 {
12285 // First bundle:
12286 0xe300c000, // movw ip, #:lower16:&GOT[2]-.+8
12287 0xe340c000, // movt ip, #:upper16:&GOT[2]-.+8
12288 0xe08cc00f, // add ip, ip, pc
12289 0xe52dc008, // str ip, [sp, #-8]!
12290 // Second bundle:
12291 0xe3ccc103, // bic ip, ip, #0xc0000000
12292 0xe59cc000, // ldr ip, [ip]
12293 0xe3ccc13f, // bic ip, ip, #0xc000000f
12294 0xe12fff1c, // bx ip
12295 // Third bundle:
12296 0xe320f000, // nop
12297 0xe320f000, // nop
12298 0xe320f000, // nop
12299 // .Lplt_tail:
12300 0xe50dc004, // str ip, [sp, #-4]
12301 // Fourth bundle:
12302 0xe3ccc103, // bic ip, ip, #0xc0000000
12303 0xe59cc000, // ldr ip, [ip]
12304 0xe3ccc13f, // bic ip, ip, #0xc000000f
12305 0xe12fff1c, // bx ip
12306 };
12307
12308 template<bool big_endian>
12309 void
12310 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12311 unsigned char* pov,
12312 Arm_address got_address,
12313 Arm_address plt_address)
12314 {
12315 // Write first PLT entry. All but first two words are constants.
12316 const size_t num_first_plt_words = (sizeof(first_plt_entry)
12317 / sizeof(first_plt_entry[0]));
12318
12319 int32_t got_displacement = got_address + 8 - (plt_address + 16);
12320
12321 elfcpp::Swap<32, big_endian>::writeval
12322 (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12323 elfcpp::Swap<32, big_endian>::writeval
12324 (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12325
12326 for (size_t i = 2; i < num_first_plt_words; ++i)
12327 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12328 }
12329
12330 // Subsequent entries in the PLT.
12331
12332 template<bool big_endian>
12333 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12334 {
12335 0xe300c000, // movw ip, #:lower16:&GOT[n]-.+8
12336 0xe340c000, // movt ip, #:upper16:&GOT[n]-.+8
12337 0xe08cc00f, // add ip, ip, pc
12338 0xea000000, // b .Lplt_tail
12339 };
12340
12341 template<bool big_endian>
12342 void
12343 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12344 unsigned char* pov,
12345 Arm_address got_address,
12346 Arm_address plt_address,
12347 unsigned int got_offset,
12348 unsigned int plt_offset)
12349 {
12350 // Calculate the displacement between the PLT slot and the
12351 // common tail that's part of the special initial PLT slot.
12352 int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12353 - (plt_address + plt_offset
12354 + sizeof(plt_entry) + sizeof(uint32_t)));
12355 gold_assert((tail_displacement & 3) == 0);
12356 tail_displacement >>= 2;
12357
12358 gold_assert ((tail_displacement & 0xff000000) == 0
12359 || (-tail_displacement & 0xff000000) == 0);
12360
12361 // Calculate the displacement between the PLT slot and the entry
12362 // in the GOT. The offset accounts for the value produced by
12363 // adding to pc in the penultimate instruction of the PLT stub.
12364 const int32_t got_displacement = (got_address + got_offset
12365 - (plt_address + sizeof(plt_entry)));
12366
12367 elfcpp::Swap<32, big_endian>::writeval
12368 (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12369 elfcpp::Swap<32, big_endian>::writeval
12370 (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12371 elfcpp::Swap<32, big_endian>::writeval
12372 (pov + 8, plt_entry[2]);
12373 elfcpp::Swap<32, big_endian>::writeval
12374 (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12375 }
12376
12377 // Target selectors.
12378
12379 template<bool big_endian>
12380 class Target_selector_arm_nacl
12381 : public Target_selector_nacl<Target_selector_arm<big_endian>,
12382 Target_arm_nacl<big_endian> >
12383 {
12384 public:
12385 Target_selector_arm_nacl()
12386 : Target_selector_nacl<Target_selector_arm<big_endian>,
12387 Target_arm_nacl<big_endian> >(
12388 "arm",
12389 big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12390 big_endian ? "armelfb_nacl" : "armelf_nacl")
12391 { }
12392 };
12393
12394 Target_selector_arm_nacl<false> target_selector_arm;
12395 Target_selector_arm_nacl<true> target_selector_armbe;
12396
12397 } // End anonymous namespace.
This page took 0.305331 seconds and 5 git commands to generate.