gold/
[deliverable/binutils-gdb.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright 2009, 2010, 2011, 2012, 2013 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), dynbss_(NULL),
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 // Space for variables copied with a COPY reloc.
2911 Output_data_space* dynbss_;
2912 // Offset of the GOT entry for the TLS module index.
2913 unsigned int got_mod_index_offset_;
2914 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2915 bool tls_base_symbol_defined_;
2916 // Vector of Stub_tables created.
2917 Stub_table_list stub_tables_;
2918 // Stub factory.
2919 const Stub_factory &stub_factory_;
2920 // Whether we force PIC branch veneers.
2921 bool should_force_pic_veneer_;
2922 // Map for locating Arm_input_sections.
2923 Arm_input_section_map arm_input_section_map_;
2924 // Attributes section data in output.
2925 Attributes_section_data* attributes_section_data_;
2926 // Whether we want to fix code for Cortex-A8 erratum.
2927 bool fix_cortex_a8_;
2928 // Map addresses to relocs for Cortex-A8 erratum.
2929 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2930 };
2931
2932 template<bool big_endian>
2933 const Target::Target_info Target_arm<big_endian>::arm_info =
2934 {
2935 32, // size
2936 big_endian, // is_big_endian
2937 elfcpp::EM_ARM, // machine_code
2938 false, // has_make_symbol
2939 false, // has_resolve
2940 false, // has_code_fill
2941 true, // is_default_stack_executable
2942 false, // can_icf_inline_merge_sections
2943 '\0', // wrap_char
2944 "/usr/lib/libc.so.1", // dynamic_linker
2945 0x8000, // default_text_segment_address
2946 0x1000, // abi_pagesize (overridable by -z max-page-size)
2947 0x1000, // common_pagesize (overridable by -z common-page-size)
2948 false, // isolate_execinstr
2949 0, // rosegment_gap
2950 elfcpp::SHN_UNDEF, // small_common_shndx
2951 elfcpp::SHN_UNDEF, // large_common_shndx
2952 0, // small_common_section_flags
2953 0, // large_common_section_flags
2954 ".ARM.attributes", // attributes_section
2955 "aeabi", // attributes_vendor
2956 "_start" // entry_symbol_name
2957 };
2958
2959 // Arm relocate functions class
2960 //
2961
2962 template<bool big_endian>
2963 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2964 {
2965 public:
2966 typedef enum
2967 {
2968 STATUS_OKAY, // No error during relocation.
2969 STATUS_OVERFLOW, // Relocation overflow.
2970 STATUS_BAD_RELOC // Relocation cannot be applied.
2971 } Status;
2972
2973 private:
2974 typedef Relocate_functions<32, big_endian> Base;
2975 typedef Arm_relocate_functions<big_endian> This;
2976
2977 // Encoding of imm16 argument for movt and movw ARM instructions
2978 // from ARM ARM:
2979 //
2980 // imm16 := imm4 | imm12
2981 //
2982 // 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
2983 // +-------+---------------+-------+-------+-----------------------+
2984 // | | |imm4 | |imm12 |
2985 // +-------+---------------+-------+-------+-----------------------+
2986
2987 // Extract the relocation addend from VAL based on the ARM
2988 // instruction encoding described above.
2989 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2990 extract_arm_movw_movt_addend(
2991 typename elfcpp::Swap<32, big_endian>::Valtype val)
2992 {
2993 // According to the Elf ABI for ARM Architecture the immediate
2994 // field is sign-extended to form the addend.
2995 return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2996 }
2997
2998 // Insert X into VAL based on the ARM instruction encoding described
2999 // above.
3000 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3001 insert_val_arm_movw_movt(
3002 typename elfcpp::Swap<32, big_endian>::Valtype val,
3003 typename elfcpp::Swap<32, big_endian>::Valtype x)
3004 {
3005 val &= 0xfff0f000;
3006 val |= x & 0x0fff;
3007 val |= (x & 0xf000) << 4;
3008 return val;
3009 }
3010
3011 // Encoding of imm16 argument for movt and movw Thumb2 instructions
3012 // from ARM ARM:
3013 //
3014 // imm16 := imm4 | i | imm3 | imm8
3015 //
3016 // 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
3017 // +---------+-+-----------+-------++-+-----+-------+---------------+
3018 // | |i| |imm4 || |imm3 | |imm8 |
3019 // +---------+-+-----------+-------++-+-----+-------+---------------+
3020
3021 // Extract the relocation addend from VAL based on the Thumb2
3022 // instruction encoding described above.
3023 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3024 extract_thumb_movw_movt_addend(
3025 typename elfcpp::Swap<32, big_endian>::Valtype val)
3026 {
3027 // According to the Elf ABI for ARM Architecture the immediate
3028 // field is sign-extended to form the addend.
3029 return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3030 | ((val >> 15) & 0x0800)
3031 | ((val >> 4) & 0x0700)
3032 | (val & 0x00ff));
3033 }
3034
3035 // Insert X into VAL based on the Thumb2 instruction encoding
3036 // described above.
3037 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3038 insert_val_thumb_movw_movt(
3039 typename elfcpp::Swap<32, big_endian>::Valtype val,
3040 typename elfcpp::Swap<32, big_endian>::Valtype x)
3041 {
3042 val &= 0xfbf08f00;
3043 val |= (x & 0xf000) << 4;
3044 val |= (x & 0x0800) << 15;
3045 val |= (x & 0x0700) << 4;
3046 val |= (x & 0x00ff);
3047 return val;
3048 }
3049
3050 // Calculate the smallest constant Kn for the specified residual.
3051 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3052 static uint32_t
3053 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3054 {
3055 int32_t msb;
3056
3057 if (residual == 0)
3058 return 0;
3059 // Determine the most significant bit in the residual and
3060 // align the resulting value to a 2-bit boundary.
3061 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3062 ;
3063 // The desired shift is now (msb - 6), or zero, whichever
3064 // is the greater.
3065 return (((msb - 6) < 0) ? 0 : (msb - 6));
3066 }
3067
3068 // Calculate the final residual for the specified group index.
3069 // If the passed group index is less than zero, the method will return
3070 // the value of the specified residual without any change.
3071 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3072 static typename elfcpp::Swap<32, big_endian>::Valtype
3073 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3074 const int group)
3075 {
3076 for (int n = 0; n <= group; n++)
3077 {
3078 // Calculate which part of the value to mask.
3079 uint32_t shift = calc_grp_kn(residual);
3080 // Calculate the residual for the next time around.
3081 residual &= ~(residual & (0xff << shift));
3082 }
3083
3084 return residual;
3085 }
3086
3087 // Calculate the value of Gn for the specified group index.
3088 // We return it in the form of an encoded constant-and-rotation.
3089 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3090 static typename elfcpp::Swap<32, big_endian>::Valtype
3091 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3092 const int group)
3093 {
3094 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3095 uint32_t shift = 0;
3096
3097 for (int n = 0; n <= group; n++)
3098 {
3099 // Calculate which part of the value to mask.
3100 shift = calc_grp_kn(residual);
3101 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3102 gn = residual & (0xff << shift);
3103 // Calculate the residual for the next time around.
3104 residual &= ~gn;
3105 }
3106 // Return Gn in the form of an encoded constant-and-rotation.
3107 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3108 }
3109
3110 public:
3111 // Handle ARM long branches.
3112 static typename This::Status
3113 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3114 unsigned char*, const Sized_symbol<32>*,
3115 const Arm_relobj<big_endian>*, unsigned int,
3116 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3117
3118 // Handle THUMB long branches.
3119 static typename This::Status
3120 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3121 unsigned char*, const Sized_symbol<32>*,
3122 const Arm_relobj<big_endian>*, unsigned int,
3123 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3124
3125
3126 // Return the branch offset of a 32-bit THUMB branch.
3127 static inline int32_t
3128 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3129 {
3130 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3131 // involving the J1 and J2 bits.
3132 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3133 uint32_t upper = upper_insn & 0x3ffU;
3134 uint32_t lower = lower_insn & 0x7ffU;
3135 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3136 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3137 uint32_t i1 = j1 ^ s ? 0 : 1;
3138 uint32_t i2 = j2 ^ s ? 0 : 1;
3139
3140 return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3141 | (upper << 12) | (lower << 1));
3142 }
3143
3144 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3145 // UPPER_INSN is the original upper instruction of the branch. Caller is
3146 // responsible for overflow checking and BLX offset adjustment.
3147 static inline uint16_t
3148 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3149 {
3150 uint32_t s = offset < 0 ? 1 : 0;
3151 uint32_t bits = static_cast<uint32_t>(offset);
3152 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3153 }
3154
3155 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3156 // LOWER_INSN is the original lower instruction of the branch. Caller is
3157 // responsible for overflow checking and BLX offset adjustment.
3158 static inline uint16_t
3159 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3160 {
3161 uint32_t s = offset < 0 ? 1 : 0;
3162 uint32_t bits = static_cast<uint32_t>(offset);
3163 return ((lower_insn & ~0x2fffU)
3164 | ((((bits >> 23) & 1) ^ !s) << 13)
3165 | ((((bits >> 22) & 1) ^ !s) << 11)
3166 | ((bits >> 1) & 0x7ffU));
3167 }
3168
3169 // Return the branch offset of a 32-bit THUMB conditional branch.
3170 static inline int32_t
3171 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3172 {
3173 uint32_t s = (upper_insn & 0x0400U) >> 10;
3174 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3175 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3176 uint32_t lower = (lower_insn & 0x07ffU);
3177 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3178
3179 return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3180 }
3181
3182 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3183 // instruction. UPPER_INSN is the original upper instruction of the branch.
3184 // Caller is responsible for overflow checking.
3185 static inline uint16_t
3186 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3187 {
3188 uint32_t s = offset < 0 ? 1 : 0;
3189 uint32_t bits = static_cast<uint32_t>(offset);
3190 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3191 }
3192
3193 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3194 // instruction. LOWER_INSN is the original lower instruction of the branch.
3195 // The caller is responsible for overflow checking.
3196 static inline uint16_t
3197 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3198 {
3199 uint32_t bits = static_cast<uint32_t>(offset);
3200 uint32_t j2 = (bits & 0x00080000U) >> 19;
3201 uint32_t j1 = (bits & 0x00040000U) >> 18;
3202 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3203
3204 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3205 }
3206
3207 // R_ARM_ABS8: S + A
3208 static inline typename This::Status
3209 abs8(unsigned char* view,
3210 const Sized_relobj_file<32, big_endian>* object,
3211 const Symbol_value<32>* psymval)
3212 {
3213 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3214 Valtype* wv = reinterpret_cast<Valtype*>(view);
3215 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3216 int32_t addend = Bits<8>::sign_extend32(val);
3217 Arm_address x = psymval->value(object, addend);
3218 val = Bits<32>::bit_select32(val, x, 0xffU);
3219 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3220
3221 // R_ARM_ABS8 permits signed or unsigned results.
3222 return (Bits<8>::has_signed_unsigned_overflow32(x)
3223 ? This::STATUS_OVERFLOW
3224 : This::STATUS_OKAY);
3225 }
3226
3227 // R_ARM_THM_ABS5: S + A
3228 static inline typename This::Status
3229 thm_abs5(unsigned char* view,
3230 const Sized_relobj_file<32, big_endian>* object,
3231 const Symbol_value<32>* psymval)
3232 {
3233 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3234 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3235 Valtype* wv = reinterpret_cast<Valtype*>(view);
3236 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3237 Reltype addend = (val & 0x7e0U) >> 6;
3238 Reltype x = psymval->value(object, addend);
3239 val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3240 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3241 return (Bits<5>::has_overflow32(x)
3242 ? This::STATUS_OVERFLOW
3243 : This::STATUS_OKAY);
3244 }
3245
3246 // R_ARM_ABS12: S + A
3247 static inline typename This::Status
3248 abs12(unsigned char* view,
3249 const Sized_relobj_file<32, big_endian>* object,
3250 const Symbol_value<32>* psymval)
3251 {
3252 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3253 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3254 Valtype* wv = reinterpret_cast<Valtype*>(view);
3255 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3256 Reltype addend = val & 0x0fffU;
3257 Reltype x = psymval->value(object, addend);
3258 val = Bits<32>::bit_select32(val, x, 0x0fffU);
3259 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3260 return (Bits<12>::has_overflow32(x)
3261 ? This::STATUS_OVERFLOW
3262 : This::STATUS_OKAY);
3263 }
3264
3265 // R_ARM_ABS16: S + A
3266 static inline typename This::Status
3267 abs16(unsigned char* view,
3268 const Sized_relobj_file<32, big_endian>* object,
3269 const Symbol_value<32>* psymval)
3270 {
3271 typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3272 Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3273 int32_t addend = Bits<16>::sign_extend32(val);
3274 Arm_address x = psymval->value(object, addend);
3275 val = Bits<32>::bit_select32(val, x, 0xffffU);
3276 elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3277
3278 // R_ARM_ABS16 permits signed or unsigned results.
3279 return (Bits<16>::has_signed_unsigned_overflow32(x)
3280 ? This::STATUS_OVERFLOW
3281 : This::STATUS_OKAY);
3282 }
3283
3284 // R_ARM_ABS32: (S + A) | T
3285 static inline typename This::Status
3286 abs32(unsigned char* view,
3287 const Sized_relobj_file<32, big_endian>* object,
3288 const Symbol_value<32>* psymval,
3289 Arm_address thumb_bit)
3290 {
3291 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3292 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3293 Valtype x = psymval->value(object, addend) | thumb_bit;
3294 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3295 return This::STATUS_OKAY;
3296 }
3297
3298 // R_ARM_REL32: (S + A) | T - P
3299 static inline typename This::Status
3300 rel32(unsigned char* view,
3301 const Sized_relobj_file<32, big_endian>* object,
3302 const Symbol_value<32>* psymval,
3303 Arm_address address,
3304 Arm_address thumb_bit)
3305 {
3306 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3307 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3308 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3309 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3310 return This::STATUS_OKAY;
3311 }
3312
3313 // R_ARM_THM_JUMP24: (S + A) | T - P
3314 static typename This::Status
3315 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3316 const Symbol_value<32>* psymval, Arm_address address,
3317 Arm_address thumb_bit);
3318
3319 // R_ARM_THM_JUMP6: S + A – P
3320 static inline typename This::Status
3321 thm_jump6(unsigned char* view,
3322 const Sized_relobj_file<32, big_endian>* object,
3323 const Symbol_value<32>* psymval,
3324 Arm_address address)
3325 {
3326 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3327 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3328 Valtype* wv = reinterpret_cast<Valtype*>(view);
3329 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3330 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3331 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3332 Reltype x = (psymval->value(object, addend) - address);
3333 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3334 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3335 // CZB does only forward jumps.
3336 return ((x > 0x007e)
3337 ? This::STATUS_OVERFLOW
3338 : This::STATUS_OKAY);
3339 }
3340
3341 // R_ARM_THM_JUMP8: S + A – P
3342 static inline typename This::Status
3343 thm_jump8(unsigned char* view,
3344 const Sized_relobj_file<32, big_endian>* object,
3345 const Symbol_value<32>* psymval,
3346 Arm_address address)
3347 {
3348 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3349 Valtype* wv = reinterpret_cast<Valtype*>(view);
3350 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3351 int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3352 int32_t x = (psymval->value(object, addend) - address);
3353 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3354 | ((x & 0x01fe) >> 1)));
3355 // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3356 return (Bits<9>::has_overflow32(x)
3357 ? This::STATUS_OVERFLOW
3358 : This::STATUS_OKAY);
3359 }
3360
3361 // R_ARM_THM_JUMP11: S + A – P
3362 static inline typename This::Status
3363 thm_jump11(unsigned char* view,
3364 const Sized_relobj_file<32, big_endian>* object,
3365 const Symbol_value<32>* psymval,
3366 Arm_address address)
3367 {
3368 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3369 Valtype* wv = reinterpret_cast<Valtype*>(view);
3370 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3371 int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3372 int32_t x = (psymval->value(object, addend) - address);
3373 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3374 | ((x & 0x0ffe) >> 1)));
3375 // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3376 return (Bits<12>::has_overflow32(x)
3377 ? This::STATUS_OVERFLOW
3378 : This::STATUS_OKAY);
3379 }
3380
3381 // R_ARM_BASE_PREL: B(S) + A - P
3382 static inline typename This::Status
3383 base_prel(unsigned char* view,
3384 Arm_address origin,
3385 Arm_address address)
3386 {
3387 Base::rel32(view, origin - address);
3388 return STATUS_OKAY;
3389 }
3390
3391 // R_ARM_BASE_ABS: B(S) + A
3392 static inline typename This::Status
3393 base_abs(unsigned char* view,
3394 Arm_address origin)
3395 {
3396 Base::rel32(view, origin);
3397 return STATUS_OKAY;
3398 }
3399
3400 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3401 static inline typename This::Status
3402 got_brel(unsigned char* view,
3403 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3404 {
3405 Base::rel32(view, got_offset);
3406 return This::STATUS_OKAY;
3407 }
3408
3409 // R_ARM_GOT_PREL: GOT(S) + A - P
3410 static inline typename This::Status
3411 got_prel(unsigned char* view,
3412 Arm_address got_entry,
3413 Arm_address address)
3414 {
3415 Base::rel32(view, got_entry - address);
3416 return This::STATUS_OKAY;
3417 }
3418
3419 // R_ARM_PREL: (S + A) | T - P
3420 static inline typename This::Status
3421 prel31(unsigned char* view,
3422 const Sized_relobj_file<32, big_endian>* object,
3423 const Symbol_value<32>* psymval,
3424 Arm_address address,
3425 Arm_address thumb_bit)
3426 {
3427 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3428 Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3429 Valtype addend = Bits<31>::sign_extend32(val);
3430 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3431 val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3432 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3433 return (Bits<31>::has_overflow32(x)
3434 ? This::STATUS_OVERFLOW
3435 : This::STATUS_OKAY);
3436 }
3437
3438 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3439 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3440 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3441 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3442 static inline typename This::Status
3443 movw(unsigned char* view,
3444 const Sized_relobj_file<32, big_endian>* object,
3445 const Symbol_value<32>* psymval,
3446 Arm_address relative_address_base,
3447 Arm_address thumb_bit,
3448 bool check_overflow)
3449 {
3450 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3451 Valtype* wv = reinterpret_cast<Valtype*>(view);
3452 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3453 Valtype addend = This::extract_arm_movw_movt_addend(val);
3454 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3455 - relative_address_base);
3456 val = This::insert_val_arm_movw_movt(val, x);
3457 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3458 return ((check_overflow && Bits<16>::has_overflow32(x))
3459 ? This::STATUS_OVERFLOW
3460 : This::STATUS_OKAY);
3461 }
3462
3463 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3464 // R_ARM_MOVT_PREL: S + A - P
3465 // R_ARM_MOVT_BREL: S + A - B(S)
3466 static inline typename This::Status
3467 movt(unsigned char* view,
3468 const Sized_relobj_file<32, big_endian>* object,
3469 const Symbol_value<32>* psymval,
3470 Arm_address relative_address_base)
3471 {
3472 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3473 Valtype* wv = reinterpret_cast<Valtype*>(view);
3474 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3475 Valtype addend = This::extract_arm_movw_movt_addend(val);
3476 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3477 val = This::insert_val_arm_movw_movt(val, x);
3478 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3479 // FIXME: IHI0044D says that we should check for overflow.
3480 return This::STATUS_OKAY;
3481 }
3482
3483 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3484 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3485 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3486 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3487 static inline typename This::Status
3488 thm_movw(unsigned char* view,
3489 const Sized_relobj_file<32, big_endian>* object,
3490 const Symbol_value<32>* psymval,
3491 Arm_address relative_address_base,
3492 Arm_address thumb_bit,
3493 bool check_overflow)
3494 {
3495 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3496 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3497 Valtype* wv = reinterpret_cast<Valtype*>(view);
3498 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3499 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3500 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3501 Reltype x =
3502 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3503 val = This::insert_val_thumb_movw_movt(val, x);
3504 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3505 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3506 return ((check_overflow && Bits<16>::has_overflow32(x))
3507 ? This::STATUS_OVERFLOW
3508 : This::STATUS_OKAY);
3509 }
3510
3511 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3512 // R_ARM_THM_MOVT_PREL: S + A - P
3513 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3514 static inline typename This::Status
3515 thm_movt(unsigned char* view,
3516 const Sized_relobj_file<32, big_endian>* object,
3517 const Symbol_value<32>* psymval,
3518 Arm_address relative_address_base)
3519 {
3520 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3521 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3522 Valtype* wv = reinterpret_cast<Valtype*>(view);
3523 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3524 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3525 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3526 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3527 val = This::insert_val_thumb_movw_movt(val, x);
3528 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3529 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3530 return This::STATUS_OKAY;
3531 }
3532
3533 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3534 static inline typename This::Status
3535 thm_alu11(unsigned char* view,
3536 const Sized_relobj_file<32, big_endian>* object,
3537 const Symbol_value<32>* psymval,
3538 Arm_address address,
3539 Arm_address thumb_bit)
3540 {
3541 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3542 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3543 Valtype* wv = reinterpret_cast<Valtype*>(view);
3544 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3545 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3546
3547 // 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
3548 // -----------------------------------------------------------------------
3549 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3550 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3551 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3552 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3553 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3554 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3555
3556 // Determine a sign for the addend.
3557 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3558 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3559 // Thumb2 addend encoding:
3560 // imm12 := i | imm3 | imm8
3561 int32_t addend = (insn & 0xff)
3562 | ((insn & 0x00007000) >> 4)
3563 | ((insn & 0x04000000) >> 15);
3564 // Apply a sign to the added.
3565 addend *= sign;
3566
3567 int32_t x = (psymval->value(object, addend) | thumb_bit)
3568 - (address & 0xfffffffc);
3569 Reltype val = abs(x);
3570 // Mask out the value and a distinct part of the ADD/SUB opcode
3571 // (bits 7:5 of opword).
3572 insn = (insn & 0xfb0f8f00)
3573 | (val & 0xff)
3574 | ((val & 0x700) << 4)
3575 | ((val & 0x800) << 15);
3576 // Set the opcode according to whether the value to go in the
3577 // place is negative.
3578 if (x < 0)
3579 insn |= 0x00a00000;
3580
3581 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3582 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3583 return ((val > 0xfff) ?
3584 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3585 }
3586
3587 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3588 static inline typename This::Status
3589 thm_pc8(unsigned char* view,
3590 const Sized_relobj_file<32, big_endian>* object,
3591 const Symbol_value<32>* psymval,
3592 Arm_address address)
3593 {
3594 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3595 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3596 Valtype* wv = reinterpret_cast<Valtype*>(view);
3597 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3598 Reltype addend = ((insn & 0x00ff) << 2);
3599 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3600 Reltype val = abs(x);
3601 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3602
3603 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3604 return ((val > 0x03fc)
3605 ? This::STATUS_OVERFLOW
3606 : This::STATUS_OKAY);
3607 }
3608
3609 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3610 static inline typename This::Status
3611 thm_pc12(unsigned char* view,
3612 const Sized_relobj_file<32, big_endian>* object,
3613 const Symbol_value<32>* psymval,
3614 Arm_address address)
3615 {
3616 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3617 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3618 Valtype* wv = reinterpret_cast<Valtype*>(view);
3619 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3620 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3621 // Determine a sign for the addend (positive if the U bit is 1).
3622 const int sign = (insn & 0x00800000) ? 1 : -1;
3623 int32_t addend = (insn & 0xfff);
3624 // Apply a sign to the added.
3625 addend *= sign;
3626
3627 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3628 Reltype val = abs(x);
3629 // Mask out and apply the value and the U bit.
3630 insn = (insn & 0xff7ff000) | (val & 0xfff);
3631 // Set the U bit according to whether the value to go in the
3632 // place is positive.
3633 if (x >= 0)
3634 insn |= 0x00800000;
3635
3636 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3637 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3638 return ((val > 0xfff) ?
3639 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3640 }
3641
3642 // R_ARM_V4BX
3643 static inline typename This::Status
3644 v4bx(const Relocate_info<32, big_endian>* relinfo,
3645 unsigned char* view,
3646 const Arm_relobj<big_endian>* object,
3647 const Arm_address address,
3648 const bool is_interworking)
3649 {
3650
3651 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3652 Valtype* wv = reinterpret_cast<Valtype*>(view);
3653 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3654
3655 // Ensure that we have a BX instruction.
3656 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3657 const uint32_t reg = (val & 0xf);
3658 if (is_interworking && reg != 0xf)
3659 {
3660 Stub_table<big_endian>* stub_table =
3661 object->stub_table(relinfo->data_shndx);
3662 gold_assert(stub_table != NULL);
3663
3664 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3665 gold_assert(stub != NULL);
3666
3667 int32_t veneer_address =
3668 stub_table->address() + stub->offset() - 8 - address;
3669 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3670 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3671 // Replace with a branch to veneer (B <addr>)
3672 val = (val & 0xf0000000) | 0x0a000000
3673 | ((veneer_address >> 2) & 0x00ffffff);
3674 }
3675 else
3676 {
3677 // Preserve Rm (lowest four bits) and the condition code
3678 // (highest four bits). Other bits encode MOV PC,Rm.
3679 val = (val & 0xf000000f) | 0x01a0f000;
3680 }
3681 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3682 return This::STATUS_OKAY;
3683 }
3684
3685 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3686 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3687 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3688 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3689 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3690 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3691 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3692 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3693 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3694 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3695 static inline typename This::Status
3696 arm_grp_alu(unsigned char* view,
3697 const Sized_relobj_file<32, big_endian>* object,
3698 const Symbol_value<32>* psymval,
3699 const int group,
3700 Arm_address address,
3701 Arm_address thumb_bit,
3702 bool check_overflow)
3703 {
3704 gold_assert(group >= 0 && group < 3);
3705 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3706 Valtype* wv = reinterpret_cast<Valtype*>(view);
3707 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3708
3709 // ALU group relocations are allowed only for the ADD/SUB instructions.
3710 // (0x00800000 - ADD, 0x00400000 - SUB)
3711 const Valtype opcode = insn & 0x01e00000;
3712 if (opcode != 0x00800000 && opcode != 0x00400000)
3713 return This::STATUS_BAD_RELOC;
3714
3715 // Determine a sign for the addend.
3716 const int sign = (opcode == 0x00800000) ? 1 : -1;
3717 // shifter = rotate_imm * 2
3718 const uint32_t shifter = (insn & 0xf00) >> 7;
3719 // Initial addend value.
3720 int32_t addend = insn & 0xff;
3721 // Rotate addend right by shifter.
3722 addend = (addend >> shifter) | (addend << (32 - shifter));
3723 // Apply a sign to the added.
3724 addend *= sign;
3725
3726 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3727 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3728 // Check for overflow if required
3729 if (check_overflow
3730 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3731 return This::STATUS_OVERFLOW;
3732
3733 // Mask out the value and the ADD/SUB part of the opcode; take care
3734 // not to destroy the S bit.
3735 insn &= 0xff1ff000;
3736 // Set the opcode according to whether the value to go in the
3737 // place is negative.
3738 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3739 // Encode the offset (encoded Gn).
3740 insn |= gn;
3741
3742 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3743 return This::STATUS_OKAY;
3744 }
3745
3746 // R_ARM_LDR_PC_G0: S + A - P
3747 // R_ARM_LDR_PC_G1: S + A - P
3748 // R_ARM_LDR_PC_G2: S + A - P
3749 // R_ARM_LDR_SB_G0: S + A - B(S)
3750 // R_ARM_LDR_SB_G1: S + A - B(S)
3751 // R_ARM_LDR_SB_G2: S + A - B(S)
3752 static inline typename This::Status
3753 arm_grp_ldr(unsigned char* view,
3754 const Sized_relobj_file<32, big_endian>* object,
3755 const Symbol_value<32>* psymval,
3756 const int group,
3757 Arm_address address)
3758 {
3759 gold_assert(group >= 0 && group < 3);
3760 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3761 Valtype* wv = reinterpret_cast<Valtype*>(view);
3762 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3763
3764 const int sign = (insn & 0x00800000) ? 1 : -1;
3765 int32_t addend = (insn & 0xfff) * sign;
3766 int32_t x = (psymval->value(object, addend) - address);
3767 // Calculate the relevant G(n-1) value to obtain this stage residual.
3768 Valtype residual =
3769 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3770 if (residual >= 0x1000)
3771 return This::STATUS_OVERFLOW;
3772
3773 // Mask out the value and U bit.
3774 insn &= 0xff7ff000;
3775 // Set the U bit for non-negative values.
3776 if (x >= 0)
3777 insn |= 0x00800000;
3778 insn |= residual;
3779
3780 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3781 return This::STATUS_OKAY;
3782 }
3783
3784 // R_ARM_LDRS_PC_G0: S + A - P
3785 // R_ARM_LDRS_PC_G1: S + A - P
3786 // R_ARM_LDRS_PC_G2: S + A - P
3787 // R_ARM_LDRS_SB_G0: S + A - B(S)
3788 // R_ARM_LDRS_SB_G1: S + A - B(S)
3789 // R_ARM_LDRS_SB_G2: S + A - B(S)
3790 static inline typename This::Status
3791 arm_grp_ldrs(unsigned char* view,
3792 const Sized_relobj_file<32, big_endian>* object,
3793 const Symbol_value<32>* psymval,
3794 const int group,
3795 Arm_address address)
3796 {
3797 gold_assert(group >= 0 && group < 3);
3798 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3799 Valtype* wv = reinterpret_cast<Valtype*>(view);
3800 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3801
3802 const int sign = (insn & 0x00800000) ? 1 : -1;
3803 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3804 int32_t x = (psymval->value(object, addend) - address);
3805 // Calculate the relevant G(n-1) value to obtain this stage residual.
3806 Valtype residual =
3807 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3808 if (residual >= 0x100)
3809 return This::STATUS_OVERFLOW;
3810
3811 // Mask out the value and U bit.
3812 insn &= 0xff7ff0f0;
3813 // Set the U bit for non-negative values.
3814 if (x >= 0)
3815 insn |= 0x00800000;
3816 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3817
3818 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3819 return This::STATUS_OKAY;
3820 }
3821
3822 // R_ARM_LDC_PC_G0: S + A - P
3823 // R_ARM_LDC_PC_G1: S + A - P
3824 // R_ARM_LDC_PC_G2: S + A - P
3825 // R_ARM_LDC_SB_G0: S + A - B(S)
3826 // R_ARM_LDC_SB_G1: S + A - B(S)
3827 // R_ARM_LDC_SB_G2: S + A - B(S)
3828 static inline typename This::Status
3829 arm_grp_ldc(unsigned char* view,
3830 const Sized_relobj_file<32, big_endian>* object,
3831 const Symbol_value<32>* psymval,
3832 const int group,
3833 Arm_address address)
3834 {
3835 gold_assert(group >= 0 && group < 3);
3836 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3837 Valtype* wv = reinterpret_cast<Valtype*>(view);
3838 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3839
3840 const int sign = (insn & 0x00800000) ? 1 : -1;
3841 int32_t addend = ((insn & 0xff) << 2) * sign;
3842 int32_t x = (psymval->value(object, addend) - address);
3843 // Calculate the relevant G(n-1) value to obtain this stage residual.
3844 Valtype residual =
3845 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3846 if ((residual & 0x3) != 0 || residual >= 0x400)
3847 return This::STATUS_OVERFLOW;
3848
3849 // Mask out the value and U bit.
3850 insn &= 0xff7fff00;
3851 // Set the U bit for non-negative values.
3852 if (x >= 0)
3853 insn |= 0x00800000;
3854 insn |= (residual >> 2);
3855
3856 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3857 return This::STATUS_OKAY;
3858 }
3859 };
3860
3861 // Relocate ARM long branches. This handles relocation types
3862 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3863 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3864 // undefined and we do not use PLT in this relocation. In such a case,
3865 // the branch is converted into an NOP.
3866
3867 template<bool big_endian>
3868 typename Arm_relocate_functions<big_endian>::Status
3869 Arm_relocate_functions<big_endian>::arm_branch_common(
3870 unsigned int r_type,
3871 const Relocate_info<32, big_endian>* relinfo,
3872 unsigned char* view,
3873 const Sized_symbol<32>* gsym,
3874 const Arm_relobj<big_endian>* object,
3875 unsigned int r_sym,
3876 const Symbol_value<32>* psymval,
3877 Arm_address address,
3878 Arm_address thumb_bit,
3879 bool is_weakly_undefined_without_plt)
3880 {
3881 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3882 Valtype* wv = reinterpret_cast<Valtype*>(view);
3883 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3884
3885 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3886 && ((val & 0x0f000000UL) == 0x0a000000UL);
3887 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3888 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3889 && ((val & 0x0f000000UL) == 0x0b000000UL);
3890 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3891 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3892
3893 // Check that the instruction is valid.
3894 if (r_type == elfcpp::R_ARM_CALL)
3895 {
3896 if (!insn_is_uncond_bl && !insn_is_blx)
3897 return This::STATUS_BAD_RELOC;
3898 }
3899 else if (r_type == elfcpp::R_ARM_JUMP24)
3900 {
3901 if (!insn_is_b && !insn_is_cond_bl)
3902 return This::STATUS_BAD_RELOC;
3903 }
3904 else if (r_type == elfcpp::R_ARM_PLT32)
3905 {
3906 if (!insn_is_any_branch)
3907 return This::STATUS_BAD_RELOC;
3908 }
3909 else if (r_type == elfcpp::R_ARM_XPC25)
3910 {
3911 // FIXME: AAELF document IH0044C does not say much about it other
3912 // than it being obsolete.
3913 if (!insn_is_any_branch)
3914 return This::STATUS_BAD_RELOC;
3915 }
3916 else
3917 gold_unreachable();
3918
3919 // A branch to an undefined weak symbol is turned into a jump to
3920 // the next instruction unless a PLT entry will be created.
3921 // Do the same for local undefined symbols.
3922 // The jump to the next instruction is optimized as a NOP depending
3923 // on the architecture.
3924 const Target_arm<big_endian>* arm_target =
3925 Target_arm<big_endian>::default_target();
3926 if (is_weakly_undefined_without_plt)
3927 {
3928 gold_assert(!parameters->options().relocatable());
3929 Valtype cond = val & 0xf0000000U;
3930 if (arm_target->may_use_arm_nop())
3931 val = cond | 0x0320f000;
3932 else
3933 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3934 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3935 return This::STATUS_OKAY;
3936 }
3937
3938 Valtype addend = Bits<26>::sign_extend32(val << 2);
3939 Valtype branch_target = psymval->value(object, addend);
3940 int32_t branch_offset = branch_target - address;
3941
3942 // We need a stub if the branch offset is too large or if we need
3943 // to switch mode.
3944 bool may_use_blx = arm_target->may_use_v5t_interworking();
3945 Reloc_stub* stub = NULL;
3946
3947 if (!parameters->options().relocatable()
3948 && (Bits<26>::has_overflow32(branch_offset)
3949 || ((thumb_bit != 0)
3950 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3951 {
3952 Valtype unadjusted_branch_target = psymval->value(object, 0);
3953
3954 Stub_type stub_type =
3955 Reloc_stub::stub_type_for_reloc(r_type, address,
3956 unadjusted_branch_target,
3957 (thumb_bit != 0));
3958 if (stub_type != arm_stub_none)
3959 {
3960 Stub_table<big_endian>* stub_table =
3961 object->stub_table(relinfo->data_shndx);
3962 gold_assert(stub_table != NULL);
3963
3964 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3965 stub = stub_table->find_reloc_stub(stub_key);
3966 gold_assert(stub != NULL);
3967 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3968 branch_target = stub_table->address() + stub->offset() + addend;
3969 branch_offset = branch_target - address;
3970 gold_assert(!Bits<26>::has_overflow32(branch_offset));
3971 }
3972 }
3973
3974 // At this point, if we still need to switch mode, the instruction
3975 // must either be a BLX or a BL that can be converted to a BLX.
3976 if (thumb_bit != 0)
3977 {
3978 // Turn BL to BLX.
3979 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3980 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3981 }
3982
3983 val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3984 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3985 return (Bits<26>::has_overflow32(branch_offset)
3986 ? This::STATUS_OVERFLOW
3987 : This::STATUS_OKAY);
3988 }
3989
3990 // Relocate THUMB long branches. This handles relocation types
3991 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3992 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3993 // undefined and we do not use PLT in this relocation. In such a case,
3994 // the branch is converted into an NOP.
3995
3996 template<bool big_endian>
3997 typename Arm_relocate_functions<big_endian>::Status
3998 Arm_relocate_functions<big_endian>::thumb_branch_common(
3999 unsigned int r_type,
4000 const Relocate_info<32, big_endian>* relinfo,
4001 unsigned char* view,
4002 const Sized_symbol<32>* gsym,
4003 const Arm_relobj<big_endian>* object,
4004 unsigned int r_sym,
4005 const Symbol_value<32>* psymval,
4006 Arm_address address,
4007 Arm_address thumb_bit,
4008 bool is_weakly_undefined_without_plt)
4009 {
4010 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4011 Valtype* wv = reinterpret_cast<Valtype*>(view);
4012 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4013 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4014
4015 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4016 // into account.
4017 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4018 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4019
4020 // Check that the instruction is valid.
4021 if (r_type == elfcpp::R_ARM_THM_CALL)
4022 {
4023 if (!is_bl_insn && !is_blx_insn)
4024 return This::STATUS_BAD_RELOC;
4025 }
4026 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4027 {
4028 // This cannot be a BLX.
4029 if (!is_bl_insn)
4030 return This::STATUS_BAD_RELOC;
4031 }
4032 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4033 {
4034 // Check for Thumb to Thumb call.
4035 if (!is_blx_insn)
4036 return This::STATUS_BAD_RELOC;
4037 if (thumb_bit != 0)
4038 {
4039 gold_warning(_("%s: Thumb BLX instruction targets "
4040 "thumb function '%s'."),
4041 object->name().c_str(),
4042 (gsym ? gsym->name() : "(local)"));
4043 // Convert BLX to BL.
4044 lower_insn |= 0x1000U;
4045 }
4046 }
4047 else
4048 gold_unreachable();
4049
4050 // A branch to an undefined weak symbol is turned into a jump to
4051 // the next instruction unless a PLT entry will be created.
4052 // The jump to the next instruction is optimized as a NOP.W for
4053 // Thumb-2 enabled architectures.
4054 const Target_arm<big_endian>* arm_target =
4055 Target_arm<big_endian>::default_target();
4056 if (is_weakly_undefined_without_plt)
4057 {
4058 gold_assert(!parameters->options().relocatable());
4059 if (arm_target->may_use_thumb2_nop())
4060 {
4061 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4062 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4063 }
4064 else
4065 {
4066 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4067 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4068 }
4069 return This::STATUS_OKAY;
4070 }
4071
4072 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4073 Arm_address branch_target = psymval->value(object, addend);
4074
4075 // For BLX, bit 1 of target address comes from bit 1 of base address.
4076 bool may_use_blx = arm_target->may_use_v5t_interworking();
4077 if (thumb_bit == 0 && may_use_blx)
4078 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4079
4080 int32_t branch_offset = branch_target - address;
4081
4082 // We need a stub if the branch offset is too large or if we need
4083 // to switch mode.
4084 bool thumb2 = arm_target->using_thumb2();
4085 if (!parameters->options().relocatable()
4086 && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4087 || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4088 || ((thumb_bit == 0)
4089 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4090 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4091 {
4092 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4093
4094 Stub_type stub_type =
4095 Reloc_stub::stub_type_for_reloc(r_type, address,
4096 unadjusted_branch_target,
4097 (thumb_bit != 0));
4098
4099 if (stub_type != arm_stub_none)
4100 {
4101 Stub_table<big_endian>* stub_table =
4102 object->stub_table(relinfo->data_shndx);
4103 gold_assert(stub_table != NULL);
4104
4105 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4106 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4107 gold_assert(stub != NULL);
4108 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4109 branch_target = stub_table->address() + stub->offset() + addend;
4110 if (thumb_bit == 0 && may_use_blx)
4111 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4112 branch_offset = branch_target - address;
4113 }
4114 }
4115
4116 // At this point, if we still need to switch mode, the instruction
4117 // must either be a BLX or a BL that can be converted to a BLX.
4118 if (thumb_bit == 0)
4119 {
4120 gold_assert(may_use_blx
4121 && (r_type == elfcpp::R_ARM_THM_CALL
4122 || r_type == elfcpp::R_ARM_THM_XPC22));
4123 // Make sure this is a BLX.
4124 lower_insn &= ~0x1000U;
4125 }
4126 else
4127 {
4128 // Make sure this is a BL.
4129 lower_insn |= 0x1000U;
4130 }
4131
4132 // For a BLX instruction, make sure that the relocation is rounded up
4133 // to a word boundary. This follows the semantics of the instruction
4134 // which specifies that bit 1 of the target address will come from bit
4135 // 1 of the base address.
4136 if ((lower_insn & 0x5000U) == 0x4000U)
4137 gold_assert((branch_offset & 3) == 0);
4138
4139 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4140 // We use the Thumb-2 encoding, which is safe even if dealing with
4141 // a Thumb-1 instruction by virtue of our overflow check above. */
4142 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4143 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4144
4145 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4146 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4147
4148 gold_assert(!Bits<25>::has_overflow32(branch_offset));
4149
4150 return ((thumb2
4151 ? Bits<25>::has_overflow32(branch_offset)
4152 : Bits<23>::has_overflow32(branch_offset))
4153 ? This::STATUS_OVERFLOW
4154 : This::STATUS_OKAY);
4155 }
4156
4157 // Relocate THUMB-2 long conditional branches.
4158 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4159 // undefined and we do not use PLT in this relocation. In such a case,
4160 // the branch is converted into an NOP.
4161
4162 template<bool big_endian>
4163 typename Arm_relocate_functions<big_endian>::Status
4164 Arm_relocate_functions<big_endian>::thm_jump19(
4165 unsigned char* view,
4166 const Arm_relobj<big_endian>* object,
4167 const Symbol_value<32>* psymval,
4168 Arm_address address,
4169 Arm_address thumb_bit)
4170 {
4171 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4172 Valtype* wv = reinterpret_cast<Valtype*>(view);
4173 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4174 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4175 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4176
4177 Arm_address branch_target = psymval->value(object, addend);
4178 int32_t branch_offset = branch_target - address;
4179
4180 // ??? Should handle interworking? GCC might someday try to
4181 // use this for tail calls.
4182 // FIXME: We do support thumb entry to PLT yet.
4183 if (thumb_bit == 0)
4184 {
4185 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4186 return This::STATUS_BAD_RELOC;
4187 }
4188
4189 // Put RELOCATION back into the insn.
4190 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4191 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4192
4193 // Put the relocated value back in the object file:
4194 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4195 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4196
4197 return (Bits<21>::has_overflow32(branch_offset)
4198 ? This::STATUS_OVERFLOW
4199 : This::STATUS_OKAY);
4200 }
4201
4202 // Get the GOT section, creating it if necessary.
4203
4204 template<bool big_endian>
4205 Arm_output_data_got<big_endian>*
4206 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4207 {
4208 if (this->got_ == NULL)
4209 {
4210 gold_assert(symtab != NULL && layout != NULL);
4211
4212 // When using -z now, we can treat .got as a relro section.
4213 // Without -z now, it is modified after program startup by lazy
4214 // PLT relocations.
4215 bool is_got_relro = parameters->options().now();
4216 Output_section_order got_order = (is_got_relro
4217 ? ORDER_RELRO_LAST
4218 : ORDER_DATA);
4219
4220 // Unlike some targets (.e.g x86), ARM does not use separate .got and
4221 // .got.plt sections in output. The output .got section contains both
4222 // PLT and non-PLT GOT entries.
4223 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4224
4225 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4226 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4227 this->got_, got_order, is_got_relro);
4228
4229 // The old GNU linker creates a .got.plt section. We just
4230 // create another set of data in the .got section. Note that we
4231 // always create a PLT if we create a GOT, although the PLT
4232 // might be empty.
4233 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4234 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4235 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4236 this->got_plt_, got_order, is_got_relro);
4237
4238 // The first three entries are reserved.
4239 this->got_plt_->set_current_data_size(3 * 4);
4240
4241 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4242 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4243 Symbol_table::PREDEFINED,
4244 this->got_plt_,
4245 0, 0, elfcpp::STT_OBJECT,
4246 elfcpp::STB_LOCAL,
4247 elfcpp::STV_HIDDEN, 0,
4248 false, false);
4249 }
4250 return this->got_;
4251 }
4252
4253 // Get the dynamic reloc section, creating it if necessary.
4254
4255 template<bool big_endian>
4256 typename Target_arm<big_endian>::Reloc_section*
4257 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4258 {
4259 if (this->rel_dyn_ == NULL)
4260 {
4261 gold_assert(layout != NULL);
4262 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4263 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4264 elfcpp::SHF_ALLOC, this->rel_dyn_,
4265 ORDER_DYNAMIC_RELOCS, false);
4266 }
4267 return this->rel_dyn_;
4268 }
4269
4270 // Insn_template methods.
4271
4272 // Return byte size of an instruction template.
4273
4274 size_t
4275 Insn_template::size() const
4276 {
4277 switch (this->type())
4278 {
4279 case THUMB16_TYPE:
4280 case THUMB16_SPECIAL_TYPE:
4281 return 2;
4282 case ARM_TYPE:
4283 case THUMB32_TYPE:
4284 case DATA_TYPE:
4285 return 4;
4286 default:
4287 gold_unreachable();
4288 }
4289 }
4290
4291 // Return alignment of an instruction template.
4292
4293 unsigned
4294 Insn_template::alignment() const
4295 {
4296 switch (this->type())
4297 {
4298 case THUMB16_TYPE:
4299 case THUMB16_SPECIAL_TYPE:
4300 case THUMB32_TYPE:
4301 return 2;
4302 case ARM_TYPE:
4303 case DATA_TYPE:
4304 return 4;
4305 default:
4306 gold_unreachable();
4307 }
4308 }
4309
4310 // Stub_template methods.
4311
4312 Stub_template::Stub_template(
4313 Stub_type type, const Insn_template* insns,
4314 size_t insn_count)
4315 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4316 entry_in_thumb_mode_(false), relocs_()
4317 {
4318 off_t offset = 0;
4319
4320 // Compute byte size and alignment of stub template.
4321 for (size_t i = 0; i < insn_count; i++)
4322 {
4323 unsigned insn_alignment = insns[i].alignment();
4324 size_t insn_size = insns[i].size();
4325 gold_assert((offset & (insn_alignment - 1)) == 0);
4326 this->alignment_ = std::max(this->alignment_, insn_alignment);
4327 switch (insns[i].type())
4328 {
4329 case Insn_template::THUMB16_TYPE:
4330 case Insn_template::THUMB16_SPECIAL_TYPE:
4331 if (i == 0)
4332 this->entry_in_thumb_mode_ = true;
4333 break;
4334
4335 case Insn_template::THUMB32_TYPE:
4336 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4337 this->relocs_.push_back(Reloc(i, offset));
4338 if (i == 0)
4339 this->entry_in_thumb_mode_ = true;
4340 break;
4341
4342 case Insn_template::ARM_TYPE:
4343 // Handle cases where the target is encoded within the
4344 // instruction.
4345 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4346 this->relocs_.push_back(Reloc(i, offset));
4347 break;
4348
4349 case Insn_template::DATA_TYPE:
4350 // Entry point cannot be data.
4351 gold_assert(i != 0);
4352 this->relocs_.push_back(Reloc(i, offset));
4353 break;
4354
4355 default:
4356 gold_unreachable();
4357 }
4358 offset += insn_size;
4359 }
4360 this->size_ = offset;
4361 }
4362
4363 // Stub methods.
4364
4365 // Template to implement do_write for a specific target endianness.
4366
4367 template<bool big_endian>
4368 void inline
4369 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4370 {
4371 const Stub_template* stub_template = this->stub_template();
4372 const Insn_template* insns = stub_template->insns();
4373
4374 // FIXME: We do not handle BE8 encoding yet.
4375 unsigned char* pov = view;
4376 for (size_t i = 0; i < stub_template->insn_count(); i++)
4377 {
4378 switch (insns[i].type())
4379 {
4380 case Insn_template::THUMB16_TYPE:
4381 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4382 break;
4383 case Insn_template::THUMB16_SPECIAL_TYPE:
4384 elfcpp::Swap<16, big_endian>::writeval(
4385 pov,
4386 this->thumb16_special(i));
4387 break;
4388 case Insn_template::THUMB32_TYPE:
4389 {
4390 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4391 uint32_t lo = insns[i].data() & 0xffff;
4392 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4393 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4394 }
4395 break;
4396 case Insn_template::ARM_TYPE:
4397 case Insn_template::DATA_TYPE:
4398 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4399 break;
4400 default:
4401 gold_unreachable();
4402 }
4403 pov += insns[i].size();
4404 }
4405 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4406 }
4407
4408 // Reloc_stub::Key methods.
4409
4410 // Dump a Key as a string for debugging.
4411
4412 std::string
4413 Reloc_stub::Key::name() const
4414 {
4415 if (this->r_sym_ == invalid_index)
4416 {
4417 // Global symbol key name
4418 // <stub-type>:<symbol name>:<addend>.
4419 const std::string sym_name = this->u_.symbol->name();
4420 // We need to print two hex number and two colons. So just add 100 bytes
4421 // to the symbol name size.
4422 size_t len = sym_name.size() + 100;
4423 char* buffer = new char[len];
4424 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4425 sym_name.c_str(), this->addend_);
4426 gold_assert(c > 0 && c < static_cast<int>(len));
4427 delete[] buffer;
4428 return std::string(buffer);
4429 }
4430 else
4431 {
4432 // local symbol key name
4433 // <stub-type>:<object>:<r_sym>:<addend>.
4434 const size_t len = 200;
4435 char buffer[len];
4436 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4437 this->u_.relobj, this->r_sym_, this->addend_);
4438 gold_assert(c > 0 && c < static_cast<int>(len));
4439 return std::string(buffer);
4440 }
4441 }
4442
4443 // Reloc_stub methods.
4444
4445 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4446 // LOCATION to DESTINATION.
4447 // This code is based on the arm_type_of_stub function in
4448 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4449 // class simple.
4450
4451 Stub_type
4452 Reloc_stub::stub_type_for_reloc(
4453 unsigned int r_type,
4454 Arm_address location,
4455 Arm_address destination,
4456 bool target_is_thumb)
4457 {
4458 Stub_type stub_type = arm_stub_none;
4459
4460 // This is a bit ugly but we want to avoid using a templated class for
4461 // big and little endianities.
4462 bool may_use_blx;
4463 bool should_force_pic_veneer;
4464 bool thumb2;
4465 bool thumb_only;
4466 if (parameters->target().is_big_endian())
4467 {
4468 const Target_arm<true>* big_endian_target =
4469 Target_arm<true>::default_target();
4470 may_use_blx = big_endian_target->may_use_v5t_interworking();
4471 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4472 thumb2 = big_endian_target->using_thumb2();
4473 thumb_only = big_endian_target->using_thumb_only();
4474 }
4475 else
4476 {
4477 const Target_arm<false>* little_endian_target =
4478 Target_arm<false>::default_target();
4479 may_use_blx = little_endian_target->may_use_v5t_interworking();
4480 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4481 thumb2 = little_endian_target->using_thumb2();
4482 thumb_only = little_endian_target->using_thumb_only();
4483 }
4484
4485 int64_t branch_offset;
4486 bool output_is_position_independent =
4487 parameters->options().output_is_position_independent();
4488 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4489 {
4490 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4491 // base address (instruction address + 4).
4492 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4493 destination = Bits<32>::bit_select32(destination, location, 0x2);
4494 branch_offset = static_cast<int64_t>(destination) - location;
4495
4496 // Handle cases where:
4497 // - this call goes too far (different Thumb/Thumb2 max
4498 // distance)
4499 // - it's a Thumb->Arm call and blx is not available, or it's a
4500 // Thumb->Arm branch (not bl). A stub is needed in this case.
4501 if ((!thumb2
4502 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4503 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4504 || (thumb2
4505 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4506 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4507 || ((!target_is_thumb)
4508 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4509 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4510 {
4511 if (target_is_thumb)
4512 {
4513 // Thumb to thumb.
4514 if (!thumb_only)
4515 {
4516 stub_type = (output_is_position_independent
4517 || should_force_pic_veneer)
4518 // PIC stubs.
4519 ? ((may_use_blx
4520 && (r_type == elfcpp::R_ARM_THM_CALL))
4521 // V5T and above. Stub starts with ARM code, so
4522 // we must be able to switch mode before
4523 // reaching it, which is only possible for 'bl'
4524 // (ie R_ARM_THM_CALL relocation).
4525 ? arm_stub_long_branch_any_thumb_pic
4526 // On V4T, use Thumb code only.
4527 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4528
4529 // non-PIC stubs.
4530 : ((may_use_blx
4531 && (r_type == elfcpp::R_ARM_THM_CALL))
4532 ? arm_stub_long_branch_any_any // V5T and above.
4533 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4534 }
4535 else
4536 {
4537 stub_type = (output_is_position_independent
4538 || should_force_pic_veneer)
4539 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4540 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4541 }
4542 }
4543 else
4544 {
4545 // Thumb to arm.
4546
4547 // FIXME: We should check that the input section is from an
4548 // object that has interwork enabled.
4549
4550 stub_type = (output_is_position_independent
4551 || should_force_pic_veneer)
4552 // PIC stubs.
4553 ? ((may_use_blx
4554 && (r_type == elfcpp::R_ARM_THM_CALL))
4555 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4556 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4557
4558 // non-PIC stubs.
4559 : ((may_use_blx
4560 && (r_type == elfcpp::R_ARM_THM_CALL))
4561 ? arm_stub_long_branch_any_any // V5T and above.
4562 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4563
4564 // Handle v4t short branches.
4565 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4566 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4567 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4568 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4569 }
4570 }
4571 }
4572 else if (r_type == elfcpp::R_ARM_CALL
4573 || r_type == elfcpp::R_ARM_JUMP24
4574 || r_type == elfcpp::R_ARM_PLT32)
4575 {
4576 branch_offset = static_cast<int64_t>(destination) - location;
4577 if (target_is_thumb)
4578 {
4579 // Arm to thumb.
4580
4581 // FIXME: We should check that the input section is from an
4582 // object that has interwork enabled.
4583
4584 // We have an extra 2-bytes reach because of
4585 // the mode change (bit 24 (H) of BLX encoding).
4586 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4587 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4588 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4589 || (r_type == elfcpp::R_ARM_JUMP24)
4590 || (r_type == elfcpp::R_ARM_PLT32))
4591 {
4592 stub_type = (output_is_position_independent
4593 || should_force_pic_veneer)
4594 // PIC stubs.
4595 ? (may_use_blx
4596 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4597 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4598
4599 // non-PIC stubs.
4600 : (may_use_blx
4601 ? arm_stub_long_branch_any_any // V5T and above.
4602 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4603 }
4604 }
4605 else
4606 {
4607 // Arm to arm.
4608 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4609 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4610 {
4611 stub_type = (output_is_position_independent
4612 || should_force_pic_veneer)
4613 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4614 : arm_stub_long_branch_any_any; /// non-PIC.
4615 }
4616 }
4617 }
4618
4619 return stub_type;
4620 }
4621
4622 // Cortex_a8_stub methods.
4623
4624 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4625 // I is the position of the instruction template in the stub template.
4626
4627 uint16_t
4628 Cortex_a8_stub::do_thumb16_special(size_t i)
4629 {
4630 // The only use of this is to copy condition code from a conditional
4631 // branch being worked around to the corresponding conditional branch in
4632 // to the stub.
4633 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4634 && i == 0);
4635 uint16_t data = this->stub_template()->insns()[i].data();
4636 gold_assert((data & 0xff00U) == 0xd000U);
4637 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4638 return data;
4639 }
4640
4641 // Stub_factory methods.
4642
4643 Stub_factory::Stub_factory()
4644 {
4645 // The instruction template sequences are declared as static
4646 // objects and initialized first time the constructor runs.
4647
4648 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4649 // to reach the stub if necessary.
4650 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4651 {
4652 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4653 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4654 // dcd R_ARM_ABS32(X)
4655 };
4656
4657 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4658 // available.
4659 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4660 {
4661 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4662 Insn_template::arm_insn(0xe12fff1c), // bx ip
4663 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4664 // dcd R_ARM_ABS32(X)
4665 };
4666
4667 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4668 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4669 {
4670 Insn_template::thumb16_insn(0xb401), // push {r0}
4671 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4672 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4673 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4674 Insn_template::thumb16_insn(0x4760), // bx ip
4675 Insn_template::thumb16_insn(0xbf00), // nop
4676 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4677 // dcd R_ARM_ABS32(X)
4678 };
4679
4680 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4681 // allowed.
4682 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4683 {
4684 Insn_template::thumb16_insn(0x4778), // bx pc
4685 Insn_template::thumb16_insn(0x46c0), // nop
4686 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4687 Insn_template::arm_insn(0xe12fff1c), // bx ip
4688 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4689 // dcd R_ARM_ABS32(X)
4690 };
4691
4692 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4693 // available.
4694 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4695 {
4696 Insn_template::thumb16_insn(0x4778), // bx pc
4697 Insn_template::thumb16_insn(0x46c0), // nop
4698 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4699 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4700 // dcd R_ARM_ABS32(X)
4701 };
4702
4703 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4704 // one, when the destination is close enough.
4705 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4706 {
4707 Insn_template::thumb16_insn(0x4778), // bx pc
4708 Insn_template::thumb16_insn(0x46c0), // nop
4709 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4710 };
4711
4712 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4713 // blx to reach the stub if necessary.
4714 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4715 {
4716 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4717 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4718 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4719 // dcd R_ARM_REL32(X-4)
4720 };
4721
4722 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4723 // blx to reach the stub if necessary. We can not add into pc;
4724 // it is not guaranteed to mode switch (different in ARMv6 and
4725 // ARMv7).
4726 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4727 {
4728 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4729 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4730 Insn_template::arm_insn(0xe12fff1c), // bx ip
4731 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4732 // dcd R_ARM_REL32(X)
4733 };
4734
4735 // V4T ARM -> ARM long branch stub, PIC.
4736 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4737 {
4738 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4739 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4740 Insn_template::arm_insn(0xe12fff1c), // bx ip
4741 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4742 // dcd R_ARM_REL32(X)
4743 };
4744
4745 // V4T Thumb -> ARM long branch stub, PIC.
4746 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4747 {
4748 Insn_template::thumb16_insn(0x4778), // bx pc
4749 Insn_template::thumb16_insn(0x46c0), // nop
4750 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4751 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4752 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4753 // dcd R_ARM_REL32(X)
4754 };
4755
4756 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4757 // architectures.
4758 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4759 {
4760 Insn_template::thumb16_insn(0xb401), // push {r0}
4761 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4762 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4763 Insn_template::thumb16_insn(0x4484), // add ip, r0
4764 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4765 Insn_template::thumb16_insn(0x4760), // bx ip
4766 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4767 // dcd R_ARM_REL32(X)
4768 };
4769
4770 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4771 // allowed.
4772 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4773 {
4774 Insn_template::thumb16_insn(0x4778), // bx pc
4775 Insn_template::thumb16_insn(0x46c0), // nop
4776 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4777 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4778 Insn_template::arm_insn(0xe12fff1c), // bx ip
4779 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4780 // dcd R_ARM_REL32(X)
4781 };
4782
4783 // Cortex-A8 erratum-workaround stubs.
4784
4785 // Stub used for conditional branches (which may be beyond +/-1MB away,
4786 // so we can't use a conditional branch to reach this stub).
4787
4788 // original code:
4789 //
4790 // b<cond> X
4791 // after:
4792 //
4793 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4794 {
4795 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4796 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4797 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4798 // b.w X
4799 };
4800
4801 // Stub used for b.w and bl.w instructions.
4802
4803 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4804 {
4805 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4806 };
4807
4808 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4809 {
4810 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4811 };
4812
4813 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4814 // instruction (which switches to ARM mode) to point to this stub. Jump to
4815 // the real destination using an ARM-mode branch.
4816 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4817 {
4818 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4819 };
4820
4821 // Stub used to provide an interworking for R_ARM_V4BX relocation
4822 // (bx r[n] instruction).
4823 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4824 {
4825 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4826 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4827 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4828 };
4829
4830 // Fill in the stub template look-up table. Stub templates are constructed
4831 // per instance of Stub_factory for fast look-up without locking
4832 // in a thread-enabled environment.
4833
4834 this->stub_templates_[arm_stub_none] =
4835 new Stub_template(arm_stub_none, NULL, 0);
4836
4837 #define DEF_STUB(x) \
4838 do \
4839 { \
4840 size_t array_size \
4841 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4842 Stub_type type = arm_stub_##x; \
4843 this->stub_templates_[type] = \
4844 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4845 } \
4846 while (0);
4847
4848 DEF_STUBS
4849 #undef DEF_STUB
4850 }
4851
4852 // Stub_table methods.
4853
4854 // Remove all Cortex-A8 stub.
4855
4856 template<bool big_endian>
4857 void
4858 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4859 {
4860 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4861 p != this->cortex_a8_stubs_.end();
4862 ++p)
4863 delete p->second;
4864 this->cortex_a8_stubs_.clear();
4865 }
4866
4867 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4868
4869 template<bool big_endian>
4870 void
4871 Stub_table<big_endian>::relocate_stub(
4872 Stub* stub,
4873 const Relocate_info<32, big_endian>* relinfo,
4874 Target_arm<big_endian>* arm_target,
4875 Output_section* output_section,
4876 unsigned char* view,
4877 Arm_address address,
4878 section_size_type view_size)
4879 {
4880 const Stub_template* stub_template = stub->stub_template();
4881 if (stub_template->reloc_count() != 0)
4882 {
4883 // Adjust view to cover the stub only.
4884 section_size_type offset = stub->offset();
4885 section_size_type stub_size = stub_template->size();
4886 gold_assert(offset + stub_size <= view_size);
4887
4888 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4889 address + offset, stub_size);
4890 }
4891 }
4892
4893 // Relocate all stubs in this stub table.
4894
4895 template<bool big_endian>
4896 void
4897 Stub_table<big_endian>::relocate_stubs(
4898 const Relocate_info<32, big_endian>* relinfo,
4899 Target_arm<big_endian>* arm_target,
4900 Output_section* output_section,
4901 unsigned char* view,
4902 Arm_address address,
4903 section_size_type view_size)
4904 {
4905 // If we are passed a view bigger than the stub table's. we need to
4906 // adjust the view.
4907 gold_assert(address == this->address()
4908 && (view_size
4909 == static_cast<section_size_type>(this->data_size())));
4910
4911 // Relocate all relocation stubs.
4912 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4913 p != this->reloc_stubs_.end();
4914 ++p)
4915 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4916 address, view_size);
4917
4918 // Relocate all Cortex-A8 stubs.
4919 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4920 p != this->cortex_a8_stubs_.end();
4921 ++p)
4922 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4923 address, view_size);
4924
4925 // Relocate all ARM V4BX stubs.
4926 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4927 p != this->arm_v4bx_stubs_.end();
4928 ++p)
4929 {
4930 if (*p != NULL)
4931 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4932 address, view_size);
4933 }
4934 }
4935
4936 // Write out the stubs to file.
4937
4938 template<bool big_endian>
4939 void
4940 Stub_table<big_endian>::do_write(Output_file* of)
4941 {
4942 off_t offset = this->offset();
4943 const section_size_type oview_size =
4944 convert_to_section_size_type(this->data_size());
4945 unsigned char* const oview = of->get_output_view(offset, oview_size);
4946
4947 // Write relocation stubs.
4948 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4949 p != this->reloc_stubs_.end();
4950 ++p)
4951 {
4952 Reloc_stub* stub = p->second;
4953 Arm_address address = this->address() + stub->offset();
4954 gold_assert(address
4955 == align_address(address,
4956 stub->stub_template()->alignment()));
4957 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4958 big_endian);
4959 }
4960
4961 // Write Cortex-A8 stubs.
4962 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4963 p != this->cortex_a8_stubs_.end();
4964 ++p)
4965 {
4966 Cortex_a8_stub* stub = p->second;
4967 Arm_address address = this->address() + stub->offset();
4968 gold_assert(address
4969 == align_address(address,
4970 stub->stub_template()->alignment()));
4971 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4972 big_endian);
4973 }
4974
4975 // Write ARM V4BX relocation stubs.
4976 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4977 p != this->arm_v4bx_stubs_.end();
4978 ++p)
4979 {
4980 if (*p == NULL)
4981 continue;
4982
4983 Arm_address address = this->address() + (*p)->offset();
4984 gold_assert(address
4985 == align_address(address,
4986 (*p)->stub_template()->alignment()));
4987 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4988 big_endian);
4989 }
4990
4991 of->write_output_view(this->offset(), oview_size, oview);
4992 }
4993
4994 // Update the data size and address alignment of the stub table at the end
4995 // of a relaxation pass. Return true if either the data size or the
4996 // alignment changed in this relaxation pass.
4997
4998 template<bool big_endian>
4999 bool
5000 Stub_table<big_endian>::update_data_size_and_addralign()
5001 {
5002 // Go over all stubs in table to compute data size and address alignment.
5003 off_t size = this->reloc_stubs_size_;
5004 unsigned addralign = this->reloc_stubs_addralign_;
5005
5006 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5007 p != this->cortex_a8_stubs_.end();
5008 ++p)
5009 {
5010 const Stub_template* stub_template = p->second->stub_template();
5011 addralign = std::max(addralign, stub_template->alignment());
5012 size = (align_address(size, stub_template->alignment())
5013 + stub_template->size());
5014 }
5015
5016 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5017 p != this->arm_v4bx_stubs_.end();
5018 ++p)
5019 {
5020 if (*p == NULL)
5021 continue;
5022
5023 const Stub_template* stub_template = (*p)->stub_template();
5024 addralign = std::max(addralign, stub_template->alignment());
5025 size = (align_address(size, stub_template->alignment())
5026 + stub_template->size());
5027 }
5028
5029 // Check if either data size or alignment changed in this pass.
5030 // Update prev_data_size_ and prev_addralign_. These will be used
5031 // as the current data size and address alignment for the next pass.
5032 bool changed = size != this->prev_data_size_;
5033 this->prev_data_size_ = size;
5034
5035 if (addralign != this->prev_addralign_)
5036 changed = true;
5037 this->prev_addralign_ = addralign;
5038
5039 return changed;
5040 }
5041
5042 // Finalize the stubs. This sets the offsets of the stubs within the stub
5043 // table. It also marks all input sections needing Cortex-A8 workaround.
5044
5045 template<bool big_endian>
5046 void
5047 Stub_table<big_endian>::finalize_stubs()
5048 {
5049 off_t off = this->reloc_stubs_size_;
5050 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5051 p != this->cortex_a8_stubs_.end();
5052 ++p)
5053 {
5054 Cortex_a8_stub* stub = p->second;
5055 const Stub_template* stub_template = stub->stub_template();
5056 uint64_t stub_addralign = stub_template->alignment();
5057 off = align_address(off, stub_addralign);
5058 stub->set_offset(off);
5059 off += stub_template->size();
5060
5061 // Mark input section so that we can determine later if a code section
5062 // needs the Cortex-A8 workaround quickly.
5063 Arm_relobj<big_endian>* arm_relobj =
5064 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5065 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5066 }
5067
5068 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5069 p != this->arm_v4bx_stubs_.end();
5070 ++p)
5071 {
5072 if (*p == NULL)
5073 continue;
5074
5075 const Stub_template* stub_template = (*p)->stub_template();
5076 uint64_t stub_addralign = stub_template->alignment();
5077 off = align_address(off, stub_addralign);
5078 (*p)->set_offset(off);
5079 off += stub_template->size();
5080 }
5081
5082 gold_assert(off <= this->prev_data_size_);
5083 }
5084
5085 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5086 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5087 // of the address range seen by the linker.
5088
5089 template<bool big_endian>
5090 void
5091 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5092 Target_arm<big_endian>* arm_target,
5093 unsigned char* view,
5094 Arm_address view_address,
5095 section_size_type view_size)
5096 {
5097 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5098 for (Cortex_a8_stub_list::const_iterator p =
5099 this->cortex_a8_stubs_.lower_bound(view_address);
5100 ((p != this->cortex_a8_stubs_.end())
5101 && (p->first < (view_address + view_size)));
5102 ++p)
5103 {
5104 // We do not store the THUMB bit in the LSB of either the branch address
5105 // or the stub offset. There is no need to strip the LSB.
5106 Arm_address branch_address = p->first;
5107 const Cortex_a8_stub* stub = p->second;
5108 Arm_address stub_address = this->address() + stub->offset();
5109
5110 // Offset of the branch instruction relative to this view.
5111 section_size_type offset =
5112 convert_to_section_size_type(branch_address - view_address);
5113 gold_assert((offset + 4) <= view_size);
5114
5115 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5116 view + offset, branch_address);
5117 }
5118 }
5119
5120 // Arm_input_section methods.
5121
5122 // Initialize an Arm_input_section.
5123
5124 template<bool big_endian>
5125 void
5126 Arm_input_section<big_endian>::init()
5127 {
5128 Relobj* relobj = this->relobj();
5129 unsigned int shndx = this->shndx();
5130
5131 // We have to cache original size, alignment and contents to avoid locking
5132 // the original file.
5133 this->original_addralign_ =
5134 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5135
5136 // This is not efficient but we expect only a small number of relaxed
5137 // input sections for stubs.
5138 section_size_type section_size;
5139 const unsigned char* section_contents =
5140 relobj->section_contents(shndx, &section_size, false);
5141 this->original_size_ =
5142 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5143
5144 gold_assert(this->original_contents_ == NULL);
5145 this->original_contents_ = new unsigned char[section_size];
5146 memcpy(this->original_contents_, section_contents, section_size);
5147
5148 // We want to make this look like the original input section after
5149 // output sections are finalized.
5150 Output_section* os = relobj->output_section(shndx);
5151 off_t offset = relobj->output_section_offset(shndx);
5152 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5153 this->set_address(os->address() + offset);
5154 this->set_file_offset(os->offset() + offset);
5155
5156 this->set_current_data_size(this->original_size_);
5157 this->finalize_data_size();
5158 }
5159
5160 template<bool big_endian>
5161 void
5162 Arm_input_section<big_endian>::do_write(Output_file* of)
5163 {
5164 // We have to write out the original section content.
5165 gold_assert(this->original_contents_ != NULL);
5166 of->write(this->offset(), this->original_contents_,
5167 this->original_size_);
5168
5169 // If this owns a stub table and it is not empty, write it.
5170 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5171 this->stub_table_->write(of);
5172 }
5173
5174 // Finalize data size.
5175
5176 template<bool big_endian>
5177 void
5178 Arm_input_section<big_endian>::set_final_data_size()
5179 {
5180 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5181
5182 if (this->is_stub_table_owner())
5183 {
5184 this->stub_table_->finalize_data_size();
5185 off = align_address(off, this->stub_table_->addralign());
5186 off += this->stub_table_->data_size();
5187 }
5188 this->set_data_size(off);
5189 }
5190
5191 // Reset address and file offset.
5192
5193 template<bool big_endian>
5194 void
5195 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5196 {
5197 // Size of the original input section contents.
5198 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5199
5200 // If this is a stub table owner, account for the stub table size.
5201 if (this->is_stub_table_owner())
5202 {
5203 Stub_table<big_endian>* stub_table = this->stub_table_;
5204
5205 // Reset the stub table's address and file offset. The
5206 // current data size for child will be updated after that.
5207 stub_table_->reset_address_and_file_offset();
5208 off = align_address(off, stub_table_->addralign());
5209 off += stub_table->current_data_size();
5210 }
5211
5212 this->set_current_data_size(off);
5213 }
5214
5215 // Arm_exidx_cantunwind methods.
5216
5217 // Write this to Output file OF for a fixed endianness.
5218
5219 template<bool big_endian>
5220 void
5221 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5222 {
5223 off_t offset = this->offset();
5224 const section_size_type oview_size = 8;
5225 unsigned char* const oview = of->get_output_view(offset, oview_size);
5226
5227 Output_section* os = this->relobj_->output_section(this->shndx_);
5228 gold_assert(os != NULL);
5229
5230 Arm_relobj<big_endian>* arm_relobj =
5231 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5232 Arm_address output_offset =
5233 arm_relobj->get_output_section_offset(this->shndx_);
5234 Arm_address section_start;
5235 section_size_type section_size;
5236
5237 // Find out the end of the text section referred by this.
5238 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5239 {
5240 section_start = os->address() + output_offset;
5241 const Arm_exidx_input_section* exidx_input_section =
5242 arm_relobj->exidx_input_section_by_link(this->shndx_);
5243 gold_assert(exidx_input_section != NULL);
5244 section_size =
5245 convert_to_section_size_type(exidx_input_section->text_size());
5246 }
5247 else
5248 {
5249 // Currently this only happens for a relaxed section.
5250 const Output_relaxed_input_section* poris =
5251 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5252 gold_assert(poris != NULL);
5253 section_start = poris->address();
5254 section_size = convert_to_section_size_type(poris->data_size());
5255 }
5256
5257 // We always append this to the end of an EXIDX section.
5258 Arm_address output_address = section_start + section_size;
5259
5260 // Write out the entry. The first word either points to the beginning
5261 // or after the end of a text section. The second word is the special
5262 // EXIDX_CANTUNWIND value.
5263 uint32_t prel31_offset = output_address - this->address();
5264 if (Bits<31>::has_overflow32(offset))
5265 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5266 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5267 prel31_offset & 0x7fffffffU);
5268 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5269 elfcpp::EXIDX_CANTUNWIND);
5270
5271 of->write_output_view(this->offset(), oview_size, oview);
5272 }
5273
5274 // Arm_exidx_merged_section methods.
5275
5276 // Constructor for Arm_exidx_merged_section.
5277 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5278 // SECTION_OFFSET_MAP points to a section offset map describing how
5279 // parts of the input section are mapped to output. DELETED_BYTES is
5280 // the number of bytes deleted from the EXIDX input section.
5281
5282 Arm_exidx_merged_section::Arm_exidx_merged_section(
5283 const Arm_exidx_input_section& exidx_input_section,
5284 const Arm_exidx_section_offset_map& section_offset_map,
5285 uint32_t deleted_bytes)
5286 : Output_relaxed_input_section(exidx_input_section.relobj(),
5287 exidx_input_section.shndx(),
5288 exidx_input_section.addralign()),
5289 exidx_input_section_(exidx_input_section),
5290 section_offset_map_(section_offset_map)
5291 {
5292 // If we retain or discard the whole EXIDX input section, we would
5293 // not be here.
5294 gold_assert(deleted_bytes != 0
5295 && deleted_bytes != this->exidx_input_section_.size());
5296
5297 // Fix size here so that we do not need to implement set_final_data_size.
5298 uint32_t size = exidx_input_section.size() - deleted_bytes;
5299 this->set_data_size(size);
5300 this->fix_data_size();
5301
5302 // Allocate buffer for section contents and build contents.
5303 this->section_contents_ = new unsigned char[size];
5304 }
5305
5306 // Build the contents of a merged EXIDX output section.
5307
5308 void
5309 Arm_exidx_merged_section::build_contents(
5310 const unsigned char* original_contents,
5311 section_size_type original_size)
5312 {
5313 // Go over spans of input offsets and write only those that are not
5314 // discarded.
5315 section_offset_type in_start = 0;
5316 section_offset_type out_start = 0;
5317 section_offset_type in_max =
5318 convert_types<section_offset_type>(original_size);
5319 section_offset_type out_max =
5320 convert_types<section_offset_type>(this->data_size());
5321 for (Arm_exidx_section_offset_map::const_iterator p =
5322 this->section_offset_map_.begin();
5323 p != this->section_offset_map_.end();
5324 ++p)
5325 {
5326 section_offset_type in_end = p->first;
5327 gold_assert(in_end >= in_start);
5328 section_offset_type out_end = p->second;
5329 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5330 if (out_end != -1)
5331 {
5332 size_t out_chunk_size =
5333 convert_types<size_t>(out_end - out_start + 1);
5334
5335 gold_assert(out_chunk_size == in_chunk_size
5336 && in_end < in_max && out_end < out_max);
5337
5338 memcpy(this->section_contents_ + out_start,
5339 original_contents + in_start,
5340 out_chunk_size);
5341 out_start += out_chunk_size;
5342 }
5343 in_start += in_chunk_size;
5344 }
5345 }
5346
5347 // Given an input OBJECT, an input section index SHNDX within that
5348 // object, and an OFFSET relative to the start of that input
5349 // section, return whether or not the corresponding offset within
5350 // the output section is known. If this function returns true, it
5351 // sets *POUTPUT to the output offset. The value -1 indicates that
5352 // this input offset is being discarded.
5353
5354 bool
5355 Arm_exidx_merged_section::do_output_offset(
5356 const Relobj* relobj,
5357 unsigned int shndx,
5358 section_offset_type offset,
5359 section_offset_type* poutput) const
5360 {
5361 // We only handle offsets for the original EXIDX input section.
5362 if (relobj != this->exidx_input_section_.relobj()
5363 || shndx != this->exidx_input_section_.shndx())
5364 return false;
5365
5366 section_offset_type section_size =
5367 convert_types<section_offset_type>(this->exidx_input_section_.size());
5368 if (offset < 0 || offset >= section_size)
5369 // Input offset is out of valid range.
5370 *poutput = -1;
5371 else
5372 {
5373 // We need to look up the section offset map to determine the output
5374 // offset. Find the reference point in map that is first offset
5375 // bigger than or equal to this offset.
5376 Arm_exidx_section_offset_map::const_iterator p =
5377 this->section_offset_map_.lower_bound(offset);
5378
5379 // The section offset maps are build such that this should not happen if
5380 // input offset is in the valid range.
5381 gold_assert(p != this->section_offset_map_.end());
5382
5383 // We need to check if this is dropped.
5384 section_offset_type ref = p->first;
5385 section_offset_type mapped_ref = p->second;
5386
5387 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5388 // Offset is present in output.
5389 *poutput = mapped_ref + (offset - ref);
5390 else
5391 // Offset is discarded owing to EXIDX entry merging.
5392 *poutput = -1;
5393 }
5394
5395 return true;
5396 }
5397
5398 // Write this to output file OF.
5399
5400 void
5401 Arm_exidx_merged_section::do_write(Output_file* of)
5402 {
5403 off_t offset = this->offset();
5404 const section_size_type oview_size = this->data_size();
5405 unsigned char* const oview = of->get_output_view(offset, oview_size);
5406
5407 Output_section* os = this->relobj()->output_section(this->shndx());
5408 gold_assert(os != NULL);
5409
5410 memcpy(oview, this->section_contents_, oview_size);
5411 of->write_output_view(this->offset(), oview_size, oview);
5412 }
5413
5414 // Arm_exidx_fixup methods.
5415
5416 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5417 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5418 // points to the end of the last seen EXIDX section.
5419
5420 void
5421 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5422 {
5423 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5424 && this->last_input_section_ != NULL)
5425 {
5426 Relobj* relobj = this->last_input_section_->relobj();
5427 unsigned int text_shndx = this->last_input_section_->link();
5428 Arm_exidx_cantunwind* cantunwind =
5429 new Arm_exidx_cantunwind(relobj, text_shndx);
5430 this->exidx_output_section_->add_output_section_data(cantunwind);
5431 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5432 }
5433 }
5434
5435 // Process an EXIDX section entry in input. Return whether this entry
5436 // can be deleted in the output. SECOND_WORD in the second word of the
5437 // EXIDX entry.
5438
5439 bool
5440 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5441 {
5442 bool delete_entry;
5443 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5444 {
5445 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5446 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5447 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5448 }
5449 else if ((second_word & 0x80000000) != 0)
5450 {
5451 // Inlined unwinding data. Merge if equal to previous.
5452 delete_entry = (merge_exidx_entries_
5453 && this->last_unwind_type_ == UT_INLINED_ENTRY
5454 && this->last_inlined_entry_ == second_word);
5455 this->last_unwind_type_ = UT_INLINED_ENTRY;
5456 this->last_inlined_entry_ = second_word;
5457 }
5458 else
5459 {
5460 // Normal table entry. In theory we could merge these too,
5461 // but duplicate entries are likely to be much less common.
5462 delete_entry = false;
5463 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5464 }
5465 return delete_entry;
5466 }
5467
5468 // Update the current section offset map during EXIDX section fix-up.
5469 // If there is no map, create one. INPUT_OFFSET is the offset of a
5470 // reference point, DELETED_BYTES is the number of deleted by in the
5471 // section so far. If DELETE_ENTRY is true, the reference point and
5472 // all offsets after the previous reference point are discarded.
5473
5474 void
5475 Arm_exidx_fixup::update_offset_map(
5476 section_offset_type input_offset,
5477 section_size_type deleted_bytes,
5478 bool delete_entry)
5479 {
5480 if (this->section_offset_map_ == NULL)
5481 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5482 section_offset_type output_offset;
5483 if (delete_entry)
5484 output_offset = Arm_exidx_input_section::invalid_offset;
5485 else
5486 output_offset = input_offset - deleted_bytes;
5487 (*this->section_offset_map_)[input_offset] = output_offset;
5488 }
5489
5490 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5491 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5492 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5493 // If some entries are merged, also store a pointer to a newly created
5494 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5495 // owns the map and is responsible for releasing it after use.
5496
5497 template<bool big_endian>
5498 uint32_t
5499 Arm_exidx_fixup::process_exidx_section(
5500 const Arm_exidx_input_section* exidx_input_section,
5501 const unsigned char* section_contents,
5502 section_size_type section_size,
5503 Arm_exidx_section_offset_map** psection_offset_map)
5504 {
5505 Relobj* relobj = exidx_input_section->relobj();
5506 unsigned shndx = exidx_input_section->shndx();
5507
5508 if ((section_size % 8) != 0)
5509 {
5510 // Something is wrong with this section. Better not touch it.
5511 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5512 relobj->name().c_str(), shndx);
5513 this->last_input_section_ = exidx_input_section;
5514 this->last_unwind_type_ = UT_NONE;
5515 return 0;
5516 }
5517
5518 uint32_t deleted_bytes = 0;
5519 bool prev_delete_entry = false;
5520 gold_assert(this->section_offset_map_ == NULL);
5521
5522 for (section_size_type i = 0; i < section_size; i += 8)
5523 {
5524 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5525 const Valtype* wv =
5526 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5527 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5528
5529 bool delete_entry = this->process_exidx_entry(second_word);
5530
5531 // Entry deletion causes changes in output offsets. We use a std::map
5532 // to record these. And entry (x, y) means input offset x
5533 // is mapped to output offset y. If y is invalid_offset, then x is
5534 // dropped in the output. Because of the way std::map::lower_bound
5535 // works, we record the last offset in a region w.r.t to keeping or
5536 // dropping. If there is no entry (x0, y0) for an input offset x0,
5537 // the output offset y0 of it is determined by the output offset y1 of
5538 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5539 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5540 // y0 is also -1.
5541 if (delete_entry != prev_delete_entry && i != 0)
5542 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5543
5544 // Update total deleted bytes for this entry.
5545 if (delete_entry)
5546 deleted_bytes += 8;
5547
5548 prev_delete_entry = delete_entry;
5549 }
5550
5551 // If section offset map is not NULL, make an entry for the end of
5552 // section.
5553 if (this->section_offset_map_ != NULL)
5554 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5555
5556 *psection_offset_map = this->section_offset_map_;
5557 this->section_offset_map_ = NULL;
5558 this->last_input_section_ = exidx_input_section;
5559
5560 // Set the first output text section so that we can link the EXIDX output
5561 // section to it. Ignore any EXIDX input section that is completely merged.
5562 if (this->first_output_text_section_ == NULL
5563 && deleted_bytes != section_size)
5564 {
5565 unsigned int link = exidx_input_section->link();
5566 Output_section* os = relobj->output_section(link);
5567 gold_assert(os != NULL);
5568 this->first_output_text_section_ = os;
5569 }
5570
5571 return deleted_bytes;
5572 }
5573
5574 // Arm_output_section methods.
5575
5576 // Create a stub group for input sections from BEGIN to END. OWNER
5577 // points to the input section to be the owner a new stub table.
5578
5579 template<bool big_endian>
5580 void
5581 Arm_output_section<big_endian>::create_stub_group(
5582 Input_section_list::const_iterator begin,
5583 Input_section_list::const_iterator end,
5584 Input_section_list::const_iterator owner,
5585 Target_arm<big_endian>* target,
5586 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5587 const Task* task)
5588 {
5589 // We use a different kind of relaxed section in an EXIDX section.
5590 // The static casting from Output_relaxed_input_section to
5591 // Arm_input_section is invalid in an EXIDX section. We are okay
5592 // because we should not be calling this for an EXIDX section.
5593 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5594
5595 // Currently we convert ordinary input sections into relaxed sections only
5596 // at this point but we may want to support creating relaxed input section
5597 // very early. So we check here to see if owner is already a relaxed
5598 // section.
5599
5600 Arm_input_section<big_endian>* arm_input_section;
5601 if (owner->is_relaxed_input_section())
5602 {
5603 arm_input_section =
5604 Arm_input_section<big_endian>::as_arm_input_section(
5605 owner->relaxed_input_section());
5606 }
5607 else
5608 {
5609 gold_assert(owner->is_input_section());
5610 // Create a new relaxed input section. We need to lock the original
5611 // file.
5612 Task_lock_obj<Object> tl(task, owner->relobj());
5613 arm_input_section =
5614 target->new_arm_input_section(owner->relobj(), owner->shndx());
5615 new_relaxed_sections->push_back(arm_input_section);
5616 }
5617
5618 // Create a stub table.
5619 Stub_table<big_endian>* stub_table =
5620 target->new_stub_table(arm_input_section);
5621
5622 arm_input_section->set_stub_table(stub_table);
5623
5624 Input_section_list::const_iterator p = begin;
5625 Input_section_list::const_iterator prev_p;
5626
5627 // Look for input sections or relaxed input sections in [begin ... end].
5628 do
5629 {
5630 if (p->is_input_section() || p->is_relaxed_input_section())
5631 {
5632 // The stub table information for input sections live
5633 // in their objects.
5634 Arm_relobj<big_endian>* arm_relobj =
5635 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5636 arm_relobj->set_stub_table(p->shndx(), stub_table);
5637 }
5638 prev_p = p++;
5639 }
5640 while (prev_p != end);
5641 }
5642
5643 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5644 // of stub groups. We grow a stub group by adding input section until the
5645 // size is just below GROUP_SIZE. The last input section will be converted
5646 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5647 // input section after the stub table, effectively double the group size.
5648 //
5649 // This is similar to the group_sections() function in elf32-arm.c but is
5650 // implemented differently.
5651
5652 template<bool big_endian>
5653 void
5654 Arm_output_section<big_endian>::group_sections(
5655 section_size_type group_size,
5656 bool stubs_always_after_branch,
5657 Target_arm<big_endian>* target,
5658 const Task* task)
5659 {
5660 // States for grouping.
5661 typedef enum
5662 {
5663 // No group is being built.
5664 NO_GROUP,
5665 // A group is being built but the stub table is not found yet.
5666 // We keep group a stub group until the size is just under GROUP_SIZE.
5667 // The last input section in the group will be used as the stub table.
5668 FINDING_STUB_SECTION,
5669 // A group is being built and we have already found a stub table.
5670 // We enter this state to grow a stub group by adding input section
5671 // after the stub table. This effectively doubles the group size.
5672 HAS_STUB_SECTION
5673 } State;
5674
5675 // Any newly created relaxed sections are stored here.
5676 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5677
5678 State state = NO_GROUP;
5679 section_size_type off = 0;
5680 section_size_type group_begin_offset = 0;
5681 section_size_type group_end_offset = 0;
5682 section_size_type stub_table_end_offset = 0;
5683 Input_section_list::const_iterator group_begin =
5684 this->input_sections().end();
5685 Input_section_list::const_iterator stub_table =
5686 this->input_sections().end();
5687 Input_section_list::const_iterator group_end = this->input_sections().end();
5688 for (Input_section_list::const_iterator p = this->input_sections().begin();
5689 p != this->input_sections().end();
5690 ++p)
5691 {
5692 section_size_type section_begin_offset =
5693 align_address(off, p->addralign());
5694 section_size_type section_end_offset =
5695 section_begin_offset + p->data_size();
5696
5697 // Check to see if we should group the previously seen sections.
5698 switch (state)
5699 {
5700 case NO_GROUP:
5701 break;
5702
5703 case FINDING_STUB_SECTION:
5704 // Adding this section makes the group larger than GROUP_SIZE.
5705 if (section_end_offset - group_begin_offset >= group_size)
5706 {
5707 if (stubs_always_after_branch)
5708 {
5709 gold_assert(group_end != this->input_sections().end());
5710 this->create_stub_group(group_begin, group_end, group_end,
5711 target, &new_relaxed_sections,
5712 task);
5713 state = NO_GROUP;
5714 }
5715 else
5716 {
5717 // But wait, there's more! Input sections up to
5718 // stub_group_size bytes after the stub table can be
5719 // handled by it too.
5720 state = HAS_STUB_SECTION;
5721 stub_table = group_end;
5722 stub_table_end_offset = group_end_offset;
5723 }
5724 }
5725 break;
5726
5727 case HAS_STUB_SECTION:
5728 // Adding this section makes the post stub-section group larger
5729 // than GROUP_SIZE.
5730 if (section_end_offset - stub_table_end_offset >= group_size)
5731 {
5732 gold_assert(group_end != this->input_sections().end());
5733 this->create_stub_group(group_begin, group_end, stub_table,
5734 target, &new_relaxed_sections, task);
5735 state = NO_GROUP;
5736 }
5737 break;
5738
5739 default:
5740 gold_unreachable();
5741 }
5742
5743 // If we see an input section and currently there is no group, start
5744 // a new one. Skip any empty sections. We look at the data size
5745 // instead of calling p->relobj()->section_size() to avoid locking.
5746 if ((p->is_input_section() || p->is_relaxed_input_section())
5747 && (p->data_size() != 0))
5748 {
5749 if (state == NO_GROUP)
5750 {
5751 state = FINDING_STUB_SECTION;
5752 group_begin = p;
5753 group_begin_offset = section_begin_offset;
5754 }
5755
5756 // Keep track of the last input section seen.
5757 group_end = p;
5758 group_end_offset = section_end_offset;
5759 }
5760
5761 off = section_end_offset;
5762 }
5763
5764 // Create a stub group for any ungrouped sections.
5765 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5766 {
5767 gold_assert(group_end != this->input_sections().end());
5768 this->create_stub_group(group_begin, group_end,
5769 (state == FINDING_STUB_SECTION
5770 ? group_end
5771 : stub_table),
5772 target, &new_relaxed_sections, task);
5773 }
5774
5775 // Convert input section into relaxed input section in a batch.
5776 if (!new_relaxed_sections.empty())
5777 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5778
5779 // Update the section offsets
5780 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5781 {
5782 Arm_relobj<big_endian>* arm_relobj =
5783 Arm_relobj<big_endian>::as_arm_relobj(
5784 new_relaxed_sections[i]->relobj());
5785 unsigned int shndx = new_relaxed_sections[i]->shndx();
5786 // Tell Arm_relobj that this input section is converted.
5787 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5788 }
5789 }
5790
5791 // Append non empty text sections in this to LIST in ascending
5792 // order of their position in this.
5793
5794 template<bool big_endian>
5795 void
5796 Arm_output_section<big_endian>::append_text_sections_to_list(
5797 Text_section_list* list)
5798 {
5799 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5800
5801 for (Input_section_list::const_iterator p = this->input_sections().begin();
5802 p != this->input_sections().end();
5803 ++p)
5804 {
5805 // We only care about plain or relaxed input sections. We also
5806 // ignore any merged sections.
5807 if (p->is_input_section() || p->is_relaxed_input_section())
5808 list->push_back(Text_section_list::value_type(p->relobj(),
5809 p->shndx()));
5810 }
5811 }
5812
5813 template<bool big_endian>
5814 void
5815 Arm_output_section<big_endian>::fix_exidx_coverage(
5816 Layout* layout,
5817 const Text_section_list& sorted_text_sections,
5818 Symbol_table* symtab,
5819 bool merge_exidx_entries,
5820 const Task* task)
5821 {
5822 // We should only do this for the EXIDX output section.
5823 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5824
5825 // We don't want the relaxation loop to undo these changes, so we discard
5826 // the current saved states and take another one after the fix-up.
5827 this->discard_states();
5828
5829 // Remove all input sections.
5830 uint64_t address = this->address();
5831 typedef std::list<Output_section::Input_section> Input_section_list;
5832 Input_section_list input_sections;
5833 this->reset_address_and_file_offset();
5834 this->get_input_sections(address, std::string(""), &input_sections);
5835
5836 if (!this->input_sections().empty())
5837 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5838
5839 // Go through all the known input sections and record them.
5840 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5841 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5842 Section_id_hash> Text_to_exidx_map;
5843 Text_to_exidx_map text_to_exidx_map;
5844 for (Input_section_list::const_iterator p = input_sections.begin();
5845 p != input_sections.end();
5846 ++p)
5847 {
5848 // This should never happen. At this point, we should only see
5849 // plain EXIDX input sections.
5850 gold_assert(!p->is_relaxed_input_section());
5851 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5852 }
5853
5854 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5855
5856 // Go over the sorted text sections.
5857 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5858 Section_id_set processed_input_sections;
5859 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5860 p != sorted_text_sections.end();
5861 ++p)
5862 {
5863 Relobj* relobj = p->first;
5864 unsigned int shndx = p->second;
5865
5866 Arm_relobj<big_endian>* arm_relobj =
5867 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5868 const Arm_exidx_input_section* exidx_input_section =
5869 arm_relobj->exidx_input_section_by_link(shndx);
5870
5871 // If this text section has no EXIDX section or if the EXIDX section
5872 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5873 // of the last seen EXIDX section.
5874 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5875 {
5876 exidx_fixup.add_exidx_cantunwind_as_needed();
5877 continue;
5878 }
5879
5880 Relobj* exidx_relobj = exidx_input_section->relobj();
5881 unsigned int exidx_shndx = exidx_input_section->shndx();
5882 Section_id sid(exidx_relobj, exidx_shndx);
5883 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5884 if (iter == text_to_exidx_map.end())
5885 {
5886 // This is odd. We have not seen this EXIDX input section before.
5887 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5888 // issue a warning instead. We assume the user knows what he
5889 // or she is doing. Otherwise, this is an error.
5890 if (layout->script_options()->saw_sections_clause())
5891 gold_warning(_("unwinding may not work because EXIDX input section"
5892 " %u of %s is not in EXIDX output section"),
5893 exidx_shndx, exidx_relobj->name().c_str());
5894 else
5895 gold_error(_("unwinding may not work because EXIDX input section"
5896 " %u of %s is not in EXIDX output section"),
5897 exidx_shndx, exidx_relobj->name().c_str());
5898
5899 exidx_fixup.add_exidx_cantunwind_as_needed();
5900 continue;
5901 }
5902
5903 // We need to access the contents of the EXIDX section, lock the
5904 // object here.
5905 Task_lock_obj<Object> tl(task, exidx_relobj);
5906 section_size_type exidx_size;
5907 const unsigned char* exidx_contents =
5908 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5909
5910 // Fix up coverage and append input section to output data list.
5911 Arm_exidx_section_offset_map* section_offset_map = NULL;
5912 uint32_t deleted_bytes =
5913 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5914 exidx_contents,
5915 exidx_size,
5916 &section_offset_map);
5917
5918 if (deleted_bytes == exidx_input_section->size())
5919 {
5920 // The whole EXIDX section got merged. Remove it from output.
5921 gold_assert(section_offset_map == NULL);
5922 exidx_relobj->set_output_section(exidx_shndx, NULL);
5923
5924 // All local symbols defined in this input section will be dropped.
5925 // We need to adjust output local symbol count.
5926 arm_relobj->set_output_local_symbol_count_needs_update();
5927 }
5928 else if (deleted_bytes > 0)
5929 {
5930 // Some entries are merged. We need to convert this EXIDX input
5931 // section into a relaxed section.
5932 gold_assert(section_offset_map != NULL);
5933
5934 Arm_exidx_merged_section* merged_section =
5935 new Arm_exidx_merged_section(*exidx_input_section,
5936 *section_offset_map, deleted_bytes);
5937 merged_section->build_contents(exidx_contents, exidx_size);
5938
5939 const std::string secname = exidx_relobj->section_name(exidx_shndx);
5940 this->add_relaxed_input_section(layout, merged_section, secname);
5941 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5942
5943 // All local symbols defined in discarded portions of this input
5944 // section will be dropped. We need to adjust output local symbol
5945 // count.
5946 arm_relobj->set_output_local_symbol_count_needs_update();
5947 }
5948 else
5949 {
5950 // Just add back the EXIDX input section.
5951 gold_assert(section_offset_map == NULL);
5952 const Output_section::Input_section* pis = iter->second;
5953 gold_assert(pis->is_input_section());
5954 this->add_script_input_section(*pis);
5955 }
5956
5957 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5958 }
5959
5960 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5961 exidx_fixup.add_exidx_cantunwind_as_needed();
5962
5963 // Remove any known EXIDX input sections that are not processed.
5964 for (Input_section_list::const_iterator p = input_sections.begin();
5965 p != input_sections.end();
5966 ++p)
5967 {
5968 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5969 == processed_input_sections.end())
5970 {
5971 // We discard a known EXIDX section because its linked
5972 // text section has been folded by ICF. We also discard an
5973 // EXIDX section with error, the output does not matter in this
5974 // case. We do this to avoid triggering asserts.
5975 Arm_relobj<big_endian>* arm_relobj =
5976 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5977 const Arm_exidx_input_section* exidx_input_section =
5978 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5979 gold_assert(exidx_input_section != NULL);
5980 if (!exidx_input_section->has_errors())
5981 {
5982 unsigned int text_shndx = exidx_input_section->link();
5983 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5984 }
5985
5986 // Remove this from link. We also need to recount the
5987 // local symbols.
5988 p->relobj()->set_output_section(p->shndx(), NULL);
5989 arm_relobj->set_output_local_symbol_count_needs_update();
5990 }
5991 }
5992
5993 // Link exidx output section to the first seen output section and
5994 // set correct entry size.
5995 this->set_link_section(exidx_fixup.first_output_text_section());
5996 this->set_entsize(8);
5997
5998 // Make changes permanent.
5999 this->save_states();
6000 this->set_section_offsets_need_adjustment();
6001 }
6002
6003 // Link EXIDX output sections to text output sections.
6004
6005 template<bool big_endian>
6006 void
6007 Arm_output_section<big_endian>::set_exidx_section_link()
6008 {
6009 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6010 if (!this->input_sections().empty())
6011 {
6012 Input_section_list::const_iterator p = this->input_sections().begin();
6013 Arm_relobj<big_endian>* arm_relobj =
6014 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6015 unsigned exidx_shndx = p->shndx();
6016 const Arm_exidx_input_section* exidx_input_section =
6017 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6018 gold_assert(exidx_input_section != NULL);
6019 unsigned int text_shndx = exidx_input_section->link();
6020 Output_section* os = arm_relobj->output_section(text_shndx);
6021 this->set_link_section(os);
6022 }
6023 }
6024
6025 // Arm_relobj methods.
6026
6027 // Determine if an input section is scannable for stub processing. SHDR is
6028 // the header of the section and SHNDX is the section index. OS is the output
6029 // section for the input section and SYMTAB is the global symbol table used to
6030 // look up ICF information.
6031
6032 template<bool big_endian>
6033 bool
6034 Arm_relobj<big_endian>::section_is_scannable(
6035 const elfcpp::Shdr<32, big_endian>& shdr,
6036 unsigned int shndx,
6037 const Output_section* os,
6038 const Symbol_table* symtab)
6039 {
6040 // Skip any empty sections, unallocated sections or sections whose
6041 // type are not SHT_PROGBITS.
6042 if (shdr.get_sh_size() == 0
6043 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6044 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6045 return false;
6046
6047 // Skip any discarded or ICF'ed sections.
6048 if (os == NULL || symtab->is_section_folded(this, shndx))
6049 return false;
6050
6051 // If this requires special offset handling, check to see if it is
6052 // a relaxed section. If this is not, then it is a merged section that
6053 // we cannot handle.
6054 if (this->is_output_section_offset_invalid(shndx))
6055 {
6056 const Output_relaxed_input_section* poris =
6057 os->find_relaxed_input_section(this, shndx);
6058 if (poris == NULL)
6059 return false;
6060 }
6061
6062 return true;
6063 }
6064
6065 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6066 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6067
6068 template<bool big_endian>
6069 bool
6070 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6071 const elfcpp::Shdr<32, big_endian>& shdr,
6072 const Relobj::Output_sections& out_sections,
6073 const Symbol_table* symtab,
6074 const unsigned char* pshdrs)
6075 {
6076 unsigned int sh_type = shdr.get_sh_type();
6077 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6078 return false;
6079
6080 // Ignore empty section.
6081 off_t sh_size = shdr.get_sh_size();
6082 if (sh_size == 0)
6083 return false;
6084
6085 // Ignore reloc section with unexpected symbol table. The
6086 // error will be reported in the final link.
6087 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6088 return false;
6089
6090 unsigned int reloc_size;
6091 if (sh_type == elfcpp::SHT_REL)
6092 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6093 else
6094 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6095
6096 // Ignore reloc section with unexpected entsize or uneven size.
6097 // The error will be reported in the final link.
6098 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6099 return false;
6100
6101 // Ignore reloc section with bad info. This error will be
6102 // reported in the final link.
6103 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6104 if (index >= this->shnum())
6105 return false;
6106
6107 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6108 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6109 return this->section_is_scannable(text_shdr, index,
6110 out_sections[index], symtab);
6111 }
6112
6113 // Return the output address of either a plain input section or a relaxed
6114 // input section. SHNDX is the section index. We define and use this
6115 // instead of calling Output_section::output_address because that is slow
6116 // for large output.
6117
6118 template<bool big_endian>
6119 Arm_address
6120 Arm_relobj<big_endian>::simple_input_section_output_address(
6121 unsigned int shndx,
6122 Output_section* os)
6123 {
6124 if (this->is_output_section_offset_invalid(shndx))
6125 {
6126 const Output_relaxed_input_section* poris =
6127 os->find_relaxed_input_section(this, shndx);
6128 // We do not handle merged sections here.
6129 gold_assert(poris != NULL);
6130 return poris->address();
6131 }
6132 else
6133 return os->address() + this->get_output_section_offset(shndx);
6134 }
6135
6136 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6137 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6138
6139 template<bool big_endian>
6140 bool
6141 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6142 const elfcpp::Shdr<32, big_endian>& shdr,
6143 unsigned int shndx,
6144 Output_section* os,
6145 const Symbol_table* symtab)
6146 {
6147 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6148 return false;
6149
6150 // If the section does not cross any 4K-boundaries, it does not need to
6151 // be scanned.
6152 Arm_address address = this->simple_input_section_output_address(shndx, os);
6153 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6154 return false;
6155
6156 return true;
6157 }
6158
6159 // Scan a section for Cortex-A8 workaround.
6160
6161 template<bool big_endian>
6162 void
6163 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6164 const elfcpp::Shdr<32, big_endian>& shdr,
6165 unsigned int shndx,
6166 Output_section* os,
6167 Target_arm<big_endian>* arm_target)
6168 {
6169 // Look for the first mapping symbol in this section. It should be
6170 // at (shndx, 0).
6171 Mapping_symbol_position section_start(shndx, 0);
6172 typename Mapping_symbols_info::const_iterator p =
6173 this->mapping_symbols_info_.lower_bound(section_start);
6174
6175 // There are no mapping symbols for this section. Treat it as a data-only
6176 // section. Issue a warning if section is marked as containing
6177 // instructions.
6178 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6179 {
6180 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6181 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6182 "erratum because it has no mapping symbols."),
6183 shndx, this->name().c_str());
6184 return;
6185 }
6186
6187 Arm_address output_address =
6188 this->simple_input_section_output_address(shndx, os);
6189
6190 // Get the section contents.
6191 section_size_type input_view_size = 0;
6192 const unsigned char* input_view =
6193 this->section_contents(shndx, &input_view_size, false);
6194
6195 // We need to go through the mapping symbols to determine what to
6196 // scan. There are two reasons. First, we should look at THUMB code and
6197 // THUMB code only. Second, we only want to look at the 4K-page boundary
6198 // to speed up the scanning.
6199
6200 while (p != this->mapping_symbols_info_.end()
6201 && p->first.first == shndx)
6202 {
6203 typename Mapping_symbols_info::const_iterator next =
6204 this->mapping_symbols_info_.upper_bound(p->first);
6205
6206 // Only scan part of a section with THUMB code.
6207 if (p->second == 't')
6208 {
6209 // Determine the end of this range.
6210 section_size_type span_start =
6211 convert_to_section_size_type(p->first.second);
6212 section_size_type span_end;
6213 if (next != this->mapping_symbols_info_.end()
6214 && next->first.first == shndx)
6215 span_end = convert_to_section_size_type(next->first.second);
6216 else
6217 span_end = convert_to_section_size_type(shdr.get_sh_size());
6218
6219 if (((span_start + output_address) & ~0xfffUL)
6220 != ((span_end + output_address - 1) & ~0xfffUL))
6221 {
6222 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6223 span_start, span_end,
6224 input_view,
6225 output_address);
6226 }
6227 }
6228
6229 p = next;
6230 }
6231 }
6232
6233 // Scan relocations for stub generation.
6234
6235 template<bool big_endian>
6236 void
6237 Arm_relobj<big_endian>::scan_sections_for_stubs(
6238 Target_arm<big_endian>* arm_target,
6239 const Symbol_table* symtab,
6240 const Layout* layout)
6241 {
6242 unsigned int shnum = this->shnum();
6243 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6244
6245 // Read the section headers.
6246 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6247 shnum * shdr_size,
6248 true, true);
6249
6250 // To speed up processing, we set up hash tables for fast lookup of
6251 // input offsets to output addresses.
6252 this->initialize_input_to_output_maps();
6253
6254 const Relobj::Output_sections& out_sections(this->output_sections());
6255
6256 Relocate_info<32, big_endian> relinfo;
6257 relinfo.symtab = symtab;
6258 relinfo.layout = layout;
6259 relinfo.object = this;
6260
6261 // Do relocation stubs scanning.
6262 const unsigned char* p = pshdrs + shdr_size;
6263 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6264 {
6265 const elfcpp::Shdr<32, big_endian> shdr(p);
6266 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6267 pshdrs))
6268 {
6269 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6270 Arm_address output_offset = this->get_output_section_offset(index);
6271 Arm_address output_address;
6272 if (output_offset != invalid_address)
6273 output_address = out_sections[index]->address() + output_offset;
6274 else
6275 {
6276 // Currently this only happens for a relaxed section.
6277 const Output_relaxed_input_section* poris =
6278 out_sections[index]->find_relaxed_input_section(this, index);
6279 gold_assert(poris != NULL);
6280 output_address = poris->address();
6281 }
6282
6283 // Get the relocations.
6284 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6285 shdr.get_sh_size(),
6286 true, false);
6287
6288 // Get the section contents. This does work for the case in which
6289 // we modify the contents of an input section. We need to pass the
6290 // output view under such circumstances.
6291 section_size_type input_view_size = 0;
6292 const unsigned char* input_view =
6293 this->section_contents(index, &input_view_size, false);
6294
6295 relinfo.reloc_shndx = i;
6296 relinfo.data_shndx = index;
6297 unsigned int sh_type = shdr.get_sh_type();
6298 unsigned int reloc_size;
6299 if (sh_type == elfcpp::SHT_REL)
6300 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6301 else
6302 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6303
6304 Output_section* os = out_sections[index];
6305 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6306 shdr.get_sh_size() / reloc_size,
6307 os,
6308 output_offset == invalid_address,
6309 input_view, output_address,
6310 input_view_size);
6311 }
6312 }
6313
6314 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6315 // after its relocation section, if there is one, is processed for
6316 // relocation stubs. Merging this loop with the one above would have been
6317 // complicated since we would have had to make sure that relocation stub
6318 // scanning is done first.
6319 if (arm_target->fix_cortex_a8())
6320 {
6321 const unsigned char* p = pshdrs + shdr_size;
6322 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6323 {
6324 const elfcpp::Shdr<32, big_endian> shdr(p);
6325 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6326 out_sections[i],
6327 symtab))
6328 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6329 arm_target);
6330 }
6331 }
6332
6333 // After we've done the relocations, we release the hash tables,
6334 // since we no longer need them.
6335 this->free_input_to_output_maps();
6336 }
6337
6338 // Count the local symbols. The ARM backend needs to know if a symbol
6339 // is a THUMB function or not. For global symbols, it is easy because
6340 // the Symbol object keeps the ELF symbol type. For local symbol it is
6341 // harder because we cannot access this information. So we override the
6342 // do_count_local_symbol in parent and scan local symbols to mark
6343 // THUMB functions. This is not the most efficient way but I do not want to
6344 // slow down other ports by calling a per symbol target hook inside
6345 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6346
6347 template<bool big_endian>
6348 void
6349 Arm_relobj<big_endian>::do_count_local_symbols(
6350 Stringpool_template<char>* pool,
6351 Stringpool_template<char>* dynpool)
6352 {
6353 // We need to fix-up the values of any local symbols whose type are
6354 // STT_ARM_TFUNC.
6355
6356 // Ask parent to count the local symbols.
6357 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6358 const unsigned int loccount = this->local_symbol_count();
6359 if (loccount == 0)
6360 return;
6361
6362 // Initialize the thumb function bit-vector.
6363 std::vector<bool> empty_vector(loccount, false);
6364 this->local_symbol_is_thumb_function_.swap(empty_vector);
6365
6366 // Read the symbol table section header.
6367 const unsigned int symtab_shndx = this->symtab_shndx();
6368 elfcpp::Shdr<32, big_endian>
6369 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6370 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6371
6372 // Read the local symbols.
6373 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6374 gold_assert(loccount == symtabshdr.get_sh_info());
6375 off_t locsize = loccount * sym_size;
6376 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6377 locsize, true, true);
6378
6379 // For mapping symbol processing, we need to read the symbol names.
6380 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6381 if (strtab_shndx >= this->shnum())
6382 {
6383 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6384 return;
6385 }
6386
6387 elfcpp::Shdr<32, big_endian>
6388 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6389 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6390 {
6391 this->error(_("symbol table name section has wrong type: %u"),
6392 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6393 return;
6394 }
6395 const char* pnames =
6396 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6397 strtabshdr.get_sh_size(),
6398 false, false));
6399
6400 // Loop over the local symbols and mark any local symbols pointing
6401 // to THUMB functions.
6402
6403 // Skip the first dummy symbol.
6404 psyms += sym_size;
6405 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6406 this->local_values();
6407 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6408 {
6409 elfcpp::Sym<32, big_endian> sym(psyms);
6410 elfcpp::STT st_type = sym.get_st_type();
6411 Symbol_value<32>& lv((*plocal_values)[i]);
6412 Arm_address input_value = lv.input_value();
6413
6414 // Check to see if this is a mapping symbol.
6415 const char* sym_name = pnames + sym.get_st_name();
6416 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6417 {
6418 bool is_ordinary;
6419 unsigned int input_shndx =
6420 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6421 gold_assert(is_ordinary);
6422
6423 // Strip of LSB in case this is a THUMB symbol.
6424 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6425 this->mapping_symbols_info_[msp] = sym_name[1];
6426 }
6427
6428 if (st_type == elfcpp::STT_ARM_TFUNC
6429 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6430 {
6431 // This is a THUMB function. Mark this and canonicalize the
6432 // symbol value by setting LSB.
6433 this->local_symbol_is_thumb_function_[i] = true;
6434 if ((input_value & 1) == 0)
6435 lv.set_input_value(input_value | 1);
6436 }
6437 }
6438 }
6439
6440 // Relocate sections.
6441 template<bool big_endian>
6442 void
6443 Arm_relobj<big_endian>::do_relocate_sections(
6444 const Symbol_table* symtab,
6445 const Layout* layout,
6446 const unsigned char* pshdrs,
6447 Output_file* of,
6448 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6449 {
6450 // Call parent to relocate sections.
6451 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6452 pshdrs, of, pviews);
6453
6454 // We do not generate stubs if doing a relocatable link.
6455 if (parameters->options().relocatable())
6456 return;
6457
6458 // Relocate stub tables.
6459 unsigned int shnum = this->shnum();
6460
6461 Target_arm<big_endian>* arm_target =
6462 Target_arm<big_endian>::default_target();
6463
6464 Relocate_info<32, big_endian> relinfo;
6465 relinfo.symtab = symtab;
6466 relinfo.layout = layout;
6467 relinfo.object = this;
6468
6469 for (unsigned int i = 1; i < shnum; ++i)
6470 {
6471 Arm_input_section<big_endian>* arm_input_section =
6472 arm_target->find_arm_input_section(this, i);
6473
6474 if (arm_input_section != NULL
6475 && arm_input_section->is_stub_table_owner()
6476 && !arm_input_section->stub_table()->empty())
6477 {
6478 // We cannot discard a section if it owns a stub table.
6479 Output_section* os = this->output_section(i);
6480 gold_assert(os != NULL);
6481
6482 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6483 relinfo.reloc_shdr = NULL;
6484 relinfo.data_shndx = i;
6485 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6486
6487 gold_assert((*pviews)[i].view != NULL);
6488
6489 // We are passed the output section view. Adjust it to cover the
6490 // stub table only.
6491 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6492 gold_assert((stub_table->address() >= (*pviews)[i].address)
6493 && ((stub_table->address() + stub_table->data_size())
6494 <= (*pviews)[i].address + (*pviews)[i].view_size));
6495
6496 off_t offset = stub_table->address() - (*pviews)[i].address;
6497 unsigned char* view = (*pviews)[i].view + offset;
6498 Arm_address address = stub_table->address();
6499 section_size_type view_size = stub_table->data_size();
6500
6501 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6502 view_size);
6503 }
6504
6505 // Apply Cortex A8 workaround if applicable.
6506 if (this->section_has_cortex_a8_workaround(i))
6507 {
6508 unsigned char* view = (*pviews)[i].view;
6509 Arm_address view_address = (*pviews)[i].address;
6510 section_size_type view_size = (*pviews)[i].view_size;
6511 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6512
6513 // Adjust view to cover section.
6514 Output_section* os = this->output_section(i);
6515 gold_assert(os != NULL);
6516 Arm_address section_address =
6517 this->simple_input_section_output_address(i, os);
6518 uint64_t section_size = this->section_size(i);
6519
6520 gold_assert(section_address >= view_address
6521 && ((section_address + section_size)
6522 <= (view_address + view_size)));
6523
6524 unsigned char* section_view = view + (section_address - view_address);
6525
6526 // Apply the Cortex-A8 workaround to the output address range
6527 // corresponding to this input section.
6528 stub_table->apply_cortex_a8_workaround_to_address_range(
6529 arm_target,
6530 section_view,
6531 section_address,
6532 section_size);
6533 }
6534 }
6535 }
6536
6537 // Find the linked text section of an EXIDX section by looking at the first
6538 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6539 // must be linked to its associated code section via the sh_link field of
6540 // its section header. However, some tools are broken and the link is not
6541 // always set. LD just drops such an EXIDX section silently, causing the
6542 // associated code not unwindabled. Here we try a little bit harder to
6543 // discover the linked code section.
6544 //
6545 // PSHDR points to the section header of a relocation section of an EXIDX
6546 // section. If we can find a linked text section, return true and
6547 // store the text section index in the location PSHNDX. Otherwise
6548 // return false.
6549
6550 template<bool big_endian>
6551 bool
6552 Arm_relobj<big_endian>::find_linked_text_section(
6553 const unsigned char* pshdr,
6554 const unsigned char* psyms,
6555 unsigned int* pshndx)
6556 {
6557 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6558
6559 // If there is no relocation, we cannot find the linked text section.
6560 size_t reloc_size;
6561 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6562 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6563 else
6564 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6565 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6566
6567 // Get the relocations.
6568 const unsigned char* prelocs =
6569 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6570
6571 // Find the REL31 relocation for the first word of the first EXIDX entry.
6572 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6573 {
6574 Arm_address r_offset;
6575 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6576 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6577 {
6578 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6579 r_info = reloc.get_r_info();
6580 r_offset = reloc.get_r_offset();
6581 }
6582 else
6583 {
6584 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6585 r_info = reloc.get_r_info();
6586 r_offset = reloc.get_r_offset();
6587 }
6588
6589 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6590 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6591 continue;
6592
6593 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6594 if (r_sym == 0
6595 || r_sym >= this->local_symbol_count()
6596 || r_offset != 0)
6597 continue;
6598
6599 // This is the relocation for the first word of the first EXIDX entry.
6600 // We expect to see a local section symbol.
6601 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6602 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6603 if (sym.get_st_type() == elfcpp::STT_SECTION)
6604 {
6605 bool is_ordinary;
6606 *pshndx =
6607 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6608 gold_assert(is_ordinary);
6609 return true;
6610 }
6611 else
6612 return false;
6613 }
6614
6615 return false;
6616 }
6617
6618 // Make an EXIDX input section object for an EXIDX section whose index is
6619 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6620 // is the section index of the linked text section.
6621
6622 template<bool big_endian>
6623 void
6624 Arm_relobj<big_endian>::make_exidx_input_section(
6625 unsigned int shndx,
6626 const elfcpp::Shdr<32, big_endian>& shdr,
6627 unsigned int text_shndx,
6628 const elfcpp::Shdr<32, big_endian>& text_shdr)
6629 {
6630 // Create an Arm_exidx_input_section object for this EXIDX section.
6631 Arm_exidx_input_section* exidx_input_section =
6632 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6633 shdr.get_sh_addralign(),
6634 text_shdr.get_sh_size());
6635
6636 gold_assert(this->exidx_section_map_[shndx] == NULL);
6637 this->exidx_section_map_[shndx] = exidx_input_section;
6638
6639 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6640 {
6641 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6642 this->section_name(shndx).c_str(), shndx, text_shndx,
6643 this->name().c_str());
6644 exidx_input_section->set_has_errors();
6645 }
6646 else if (this->exidx_section_map_[text_shndx] != NULL)
6647 {
6648 unsigned other_exidx_shndx =
6649 this->exidx_section_map_[text_shndx]->shndx();
6650 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6651 "%s(%u) in %s"),
6652 this->section_name(shndx).c_str(), shndx,
6653 this->section_name(other_exidx_shndx).c_str(),
6654 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6655 text_shndx, this->name().c_str());
6656 exidx_input_section->set_has_errors();
6657 }
6658 else
6659 this->exidx_section_map_[text_shndx] = exidx_input_section;
6660
6661 // Check section flags of text section.
6662 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6663 {
6664 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6665 " in %s"),
6666 this->section_name(shndx).c_str(), shndx,
6667 this->section_name(text_shndx).c_str(), text_shndx,
6668 this->name().c_str());
6669 exidx_input_section->set_has_errors();
6670 }
6671 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6672 // I would like to make this an error but currently ld just ignores
6673 // this.
6674 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6675 "%s(%u) in %s"),
6676 this->section_name(shndx).c_str(), shndx,
6677 this->section_name(text_shndx).c_str(), text_shndx,
6678 this->name().c_str());
6679 }
6680
6681 // Read the symbol information.
6682
6683 template<bool big_endian>
6684 void
6685 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6686 {
6687 // Call parent class to read symbol information.
6688 Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6689
6690 // If this input file is a binary file, it has no processor
6691 // specific flags and attributes section.
6692 Input_file::Format format = this->input_file()->format();
6693 if (format != Input_file::FORMAT_ELF)
6694 {
6695 gold_assert(format == Input_file::FORMAT_BINARY);
6696 this->merge_flags_and_attributes_ = false;
6697 return;
6698 }
6699
6700 // Read processor-specific flags in ELF file header.
6701 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6702 elfcpp::Elf_sizes<32>::ehdr_size,
6703 true, false);
6704 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6705 this->processor_specific_flags_ = ehdr.get_e_flags();
6706
6707 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6708 // sections.
6709 std::vector<unsigned int> deferred_exidx_sections;
6710 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6711 const unsigned char* pshdrs = sd->section_headers->data();
6712 const unsigned char* ps = pshdrs + shdr_size;
6713 bool must_merge_flags_and_attributes = false;
6714 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6715 {
6716 elfcpp::Shdr<32, big_endian> shdr(ps);
6717
6718 // Sometimes an object has no contents except the section name string
6719 // table and an empty symbol table with the undefined symbol. We
6720 // don't want to merge processor-specific flags from such an object.
6721 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6722 {
6723 // Symbol table is not empty.
6724 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6725 elfcpp::Elf_sizes<32>::sym_size;
6726 if (shdr.get_sh_size() > sym_size)
6727 must_merge_flags_and_attributes = true;
6728 }
6729 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6730 // If this is neither an empty symbol table nor a string table,
6731 // be conservative.
6732 must_merge_flags_and_attributes = true;
6733
6734 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6735 {
6736 gold_assert(this->attributes_section_data_ == NULL);
6737 section_offset_type section_offset = shdr.get_sh_offset();
6738 section_size_type section_size =
6739 convert_to_section_size_type(shdr.get_sh_size());
6740 const unsigned char* view =
6741 this->get_view(section_offset, section_size, true, false);
6742 this->attributes_section_data_ =
6743 new Attributes_section_data(view, section_size);
6744 }
6745 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6746 {
6747 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6748 if (text_shndx == elfcpp::SHN_UNDEF)
6749 deferred_exidx_sections.push_back(i);
6750 else
6751 {
6752 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6753 + text_shndx * shdr_size);
6754 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6755 }
6756 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6757 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6758 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6759 this->section_name(i).c_str(), this->name().c_str());
6760 }
6761 }
6762
6763 // This is rare.
6764 if (!must_merge_flags_and_attributes)
6765 {
6766 gold_assert(deferred_exidx_sections.empty());
6767 this->merge_flags_and_attributes_ = false;
6768 return;
6769 }
6770
6771 // Some tools are broken and they do not set the link of EXIDX sections.
6772 // We look at the first relocation to figure out the linked sections.
6773 if (!deferred_exidx_sections.empty())
6774 {
6775 // We need to go over the section headers again to find the mapping
6776 // from sections being relocated to their relocation sections. This is
6777 // a bit inefficient as we could do that in the loop above. However,
6778 // we do not expect any deferred EXIDX sections normally. So we do not
6779 // want to slow down the most common path.
6780 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6781 Reloc_map reloc_map;
6782 ps = pshdrs + shdr_size;
6783 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6784 {
6785 elfcpp::Shdr<32, big_endian> shdr(ps);
6786 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6787 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6788 {
6789 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6790 if (info_shndx >= this->shnum())
6791 gold_error(_("relocation section %u has invalid info %u"),
6792 i, info_shndx);
6793 Reloc_map::value_type value(info_shndx, i);
6794 std::pair<Reloc_map::iterator, bool> result =
6795 reloc_map.insert(value);
6796 if (!result.second)
6797 gold_error(_("section %u has multiple relocation sections "
6798 "%u and %u"),
6799 info_shndx, i, reloc_map[info_shndx]);
6800 }
6801 }
6802
6803 // Read the symbol table section header.
6804 const unsigned int symtab_shndx = this->symtab_shndx();
6805 elfcpp::Shdr<32, big_endian>
6806 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6807 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6808
6809 // Read the local symbols.
6810 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6811 const unsigned int loccount = this->local_symbol_count();
6812 gold_assert(loccount == symtabshdr.get_sh_info());
6813 off_t locsize = loccount * sym_size;
6814 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6815 locsize, true, true);
6816
6817 // Process the deferred EXIDX sections.
6818 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6819 {
6820 unsigned int shndx = deferred_exidx_sections[i];
6821 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6822 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6823 Reloc_map::const_iterator it = reloc_map.find(shndx);
6824 if (it != reloc_map.end())
6825 find_linked_text_section(pshdrs + it->second * shdr_size,
6826 psyms, &text_shndx);
6827 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6828 + text_shndx * shdr_size);
6829 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6830 }
6831 }
6832 }
6833
6834 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6835 // sections for unwinding. These sections are referenced implicitly by
6836 // text sections linked in the section headers. If we ignore these implicit
6837 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6838 // will be garbage-collected incorrectly. Hence we override the same function
6839 // in the base class to handle these implicit references.
6840
6841 template<bool big_endian>
6842 void
6843 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6844 Layout* layout,
6845 Read_relocs_data* rd)
6846 {
6847 // First, call base class method to process relocations in this object.
6848 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6849
6850 // If --gc-sections is not specified, there is nothing more to do.
6851 // This happens when --icf is used but --gc-sections is not.
6852 if (!parameters->options().gc_sections())
6853 return;
6854
6855 unsigned int shnum = this->shnum();
6856 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6857 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6858 shnum * shdr_size,
6859 true, true);
6860
6861 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6862 // to these from the linked text sections.
6863 const unsigned char* ps = pshdrs + shdr_size;
6864 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6865 {
6866 elfcpp::Shdr<32, big_endian> shdr(ps);
6867 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6868 {
6869 // Found an .ARM.exidx section, add it to the set of reachable
6870 // sections from its linked text section.
6871 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6872 symtab->gc()->add_reference(this, text_shndx, this, i);
6873 }
6874 }
6875 }
6876
6877 // Update output local symbol count. Owing to EXIDX entry merging, some local
6878 // symbols will be removed in output. Adjust output local symbol count
6879 // accordingly. We can only changed the static output local symbol count. It
6880 // is too late to change the dynamic symbols.
6881
6882 template<bool big_endian>
6883 void
6884 Arm_relobj<big_endian>::update_output_local_symbol_count()
6885 {
6886 // Caller should check that this needs updating. We want caller checking
6887 // because output_local_symbol_count_needs_update() is most likely inlined.
6888 gold_assert(this->output_local_symbol_count_needs_update_);
6889
6890 gold_assert(this->symtab_shndx() != -1U);
6891 if (this->symtab_shndx() == 0)
6892 {
6893 // This object has no symbols. Weird but legal.
6894 return;
6895 }
6896
6897 // Read the symbol table section header.
6898 const unsigned int symtab_shndx = this->symtab_shndx();
6899 elfcpp::Shdr<32, big_endian>
6900 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6901 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6902
6903 // Read the local symbols.
6904 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6905 const unsigned int loccount = this->local_symbol_count();
6906 gold_assert(loccount == symtabshdr.get_sh_info());
6907 off_t locsize = loccount * sym_size;
6908 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6909 locsize, true, true);
6910
6911 // Loop over the local symbols.
6912
6913 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6914 Output_sections;
6915 const Output_sections& out_sections(this->output_sections());
6916 unsigned int shnum = this->shnum();
6917 unsigned int count = 0;
6918 // Skip the first, dummy, symbol.
6919 psyms += sym_size;
6920 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6921 {
6922 elfcpp::Sym<32, big_endian> sym(psyms);
6923
6924 Symbol_value<32>& lv((*this->local_values())[i]);
6925
6926 // This local symbol was already discarded by do_count_local_symbols.
6927 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6928 continue;
6929
6930 bool is_ordinary;
6931 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6932 &is_ordinary);
6933
6934 if (shndx < shnum)
6935 {
6936 Output_section* os = out_sections[shndx];
6937
6938 // This local symbol no longer has an output section. Discard it.
6939 if (os == NULL)
6940 {
6941 lv.set_no_output_symtab_entry();
6942 continue;
6943 }
6944
6945 // Currently we only discard parts of EXIDX input sections.
6946 // We explicitly check for a merged EXIDX input section to avoid
6947 // calling Output_section_data::output_offset unless necessary.
6948 if ((this->get_output_section_offset(shndx) == invalid_address)
6949 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6950 {
6951 section_offset_type output_offset =
6952 os->output_offset(this, shndx, lv.input_value());
6953 if (output_offset == -1)
6954 {
6955 // This symbol is defined in a part of an EXIDX input section
6956 // that is discarded due to entry merging.
6957 lv.set_no_output_symtab_entry();
6958 continue;
6959 }
6960 }
6961 }
6962
6963 ++count;
6964 }
6965
6966 this->set_output_local_symbol_count(count);
6967 this->output_local_symbol_count_needs_update_ = false;
6968 }
6969
6970 // Arm_dynobj methods.
6971
6972 // Read the symbol information.
6973
6974 template<bool big_endian>
6975 void
6976 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6977 {
6978 // Call parent class to read symbol information.
6979 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6980
6981 // Read processor-specific flags in ELF file header.
6982 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6983 elfcpp::Elf_sizes<32>::ehdr_size,
6984 true, false);
6985 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6986 this->processor_specific_flags_ = ehdr.get_e_flags();
6987
6988 // Read the attributes section if there is one.
6989 // We read from the end because gas seems to put it near the end of
6990 // the section headers.
6991 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6992 const unsigned char* ps =
6993 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6994 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6995 {
6996 elfcpp::Shdr<32, big_endian> shdr(ps);
6997 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6998 {
6999 section_offset_type section_offset = shdr.get_sh_offset();
7000 section_size_type section_size =
7001 convert_to_section_size_type(shdr.get_sh_size());
7002 const unsigned char* view =
7003 this->get_view(section_offset, section_size, true, false);
7004 this->attributes_section_data_ =
7005 new Attributes_section_data(view, section_size);
7006 break;
7007 }
7008 }
7009 }
7010
7011 // Stub_addend_reader methods.
7012
7013 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7014
7015 template<bool big_endian>
7016 elfcpp::Elf_types<32>::Elf_Swxword
7017 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7018 unsigned int r_type,
7019 const unsigned char* view,
7020 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7021 {
7022 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7023
7024 switch (r_type)
7025 {
7026 case elfcpp::R_ARM_CALL:
7027 case elfcpp::R_ARM_JUMP24:
7028 case elfcpp::R_ARM_PLT32:
7029 {
7030 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7031 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7032 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7033 return Bits<26>::sign_extend32(val << 2);
7034 }
7035
7036 case elfcpp::R_ARM_THM_CALL:
7037 case elfcpp::R_ARM_THM_JUMP24:
7038 case elfcpp::R_ARM_THM_XPC22:
7039 {
7040 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7041 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7042 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7043 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7044 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7045 }
7046
7047 case elfcpp::R_ARM_THM_JUMP19:
7048 {
7049 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7050 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7051 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7052 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7053 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7054 }
7055
7056 default:
7057 gold_unreachable();
7058 }
7059 }
7060
7061 // Arm_output_data_got methods.
7062
7063 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7064 // The first one is initialized to be 1, which is the module index for
7065 // the main executable and the second one 0. A reloc of the type
7066 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7067 // be applied by gold. GSYM is a global symbol.
7068 //
7069 template<bool big_endian>
7070 void
7071 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7072 unsigned int got_type,
7073 Symbol* gsym)
7074 {
7075 if (gsym->has_got_offset(got_type))
7076 return;
7077
7078 // We are doing a static link. Just mark it as belong to module 1,
7079 // the executable.
7080 unsigned int got_offset = this->add_constant(1);
7081 gsym->set_got_offset(got_type, got_offset);
7082 got_offset = this->add_constant(0);
7083 this->static_relocs_.push_back(Static_reloc(got_offset,
7084 elfcpp::R_ARM_TLS_DTPOFF32,
7085 gsym));
7086 }
7087
7088 // Same as the above but for a local symbol.
7089
7090 template<bool big_endian>
7091 void
7092 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7093 unsigned int got_type,
7094 Sized_relobj_file<32, big_endian>* object,
7095 unsigned int index)
7096 {
7097 if (object->local_has_got_offset(index, got_type))
7098 return;
7099
7100 // We are doing a static link. Just mark it as belong to module 1,
7101 // the executable.
7102 unsigned int got_offset = this->add_constant(1);
7103 object->set_local_got_offset(index, got_type, got_offset);
7104 got_offset = this->add_constant(0);
7105 this->static_relocs_.push_back(Static_reloc(got_offset,
7106 elfcpp::R_ARM_TLS_DTPOFF32,
7107 object, index));
7108 }
7109
7110 template<bool big_endian>
7111 void
7112 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7113 {
7114 // Call parent to write out GOT.
7115 Output_data_got<32, big_endian>::do_write(of);
7116
7117 // We are done if there is no fix up.
7118 if (this->static_relocs_.empty())
7119 return;
7120
7121 gold_assert(parameters->doing_static_link());
7122
7123 const off_t offset = this->offset();
7124 const section_size_type oview_size =
7125 convert_to_section_size_type(this->data_size());
7126 unsigned char* const oview = of->get_output_view(offset, oview_size);
7127
7128 Output_segment* tls_segment = this->layout_->tls_segment();
7129 gold_assert(tls_segment != NULL);
7130
7131 // The thread pointer $tp points to the TCB, which is followed by the
7132 // TLS. So we need to adjust $tp relative addressing by this amount.
7133 Arm_address aligned_tcb_size =
7134 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7135
7136 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7137 {
7138 Static_reloc& reloc(this->static_relocs_[i]);
7139
7140 Arm_address value;
7141 if (!reloc.symbol_is_global())
7142 {
7143 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7144 const Symbol_value<32>* psymval =
7145 reloc.relobj()->local_symbol(reloc.index());
7146
7147 // We are doing static linking. Issue an error and skip this
7148 // relocation if the symbol is undefined or in a discarded_section.
7149 bool is_ordinary;
7150 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7151 if ((shndx == elfcpp::SHN_UNDEF)
7152 || (is_ordinary
7153 && shndx != elfcpp::SHN_UNDEF
7154 && !object->is_section_included(shndx)
7155 && !this->symbol_table_->is_section_folded(object, shndx)))
7156 {
7157 gold_error(_("undefined or discarded local symbol %u from "
7158 " object %s in GOT"),
7159 reloc.index(), reloc.relobj()->name().c_str());
7160 continue;
7161 }
7162
7163 value = psymval->value(object, 0);
7164 }
7165 else
7166 {
7167 const Symbol* gsym = reloc.symbol();
7168 gold_assert(gsym != NULL);
7169 if (gsym->is_forwarder())
7170 gsym = this->symbol_table_->resolve_forwards(gsym);
7171
7172 // We are doing static linking. Issue an error and skip this
7173 // relocation if the symbol is undefined or in a discarded_section
7174 // unless it is a weakly_undefined symbol.
7175 if ((gsym->is_defined_in_discarded_section()
7176 || gsym->is_undefined())
7177 && !gsym->is_weak_undefined())
7178 {
7179 gold_error(_("undefined or discarded symbol %s in GOT"),
7180 gsym->name());
7181 continue;
7182 }
7183
7184 if (!gsym->is_weak_undefined())
7185 {
7186 const Sized_symbol<32>* sym =
7187 static_cast<const Sized_symbol<32>*>(gsym);
7188 value = sym->value();
7189 }
7190 else
7191 value = 0;
7192 }
7193
7194 unsigned got_offset = reloc.got_offset();
7195 gold_assert(got_offset < oview_size);
7196
7197 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7198 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7199 Valtype x;
7200 switch (reloc.r_type())
7201 {
7202 case elfcpp::R_ARM_TLS_DTPOFF32:
7203 x = value;
7204 break;
7205 case elfcpp::R_ARM_TLS_TPOFF32:
7206 x = value + aligned_tcb_size;
7207 break;
7208 default:
7209 gold_unreachable();
7210 }
7211 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7212 }
7213
7214 of->write_output_view(offset, oview_size, oview);
7215 }
7216
7217 // A class to handle the PLT data.
7218 // This is an abstract base class that handles most of the linker details
7219 // but does not know the actual contents of PLT entries. The derived
7220 // classes below fill in those details.
7221
7222 template<bool big_endian>
7223 class Output_data_plt_arm : public Output_section_data
7224 {
7225 public:
7226 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7227 Reloc_section;
7228
7229 Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7230
7231 // Add an entry to the PLT.
7232 void
7233 add_entry(Symbol* gsym);
7234
7235 // Return the .rel.plt section data.
7236 const Reloc_section*
7237 rel_plt() const
7238 { return this->rel_; }
7239
7240 // Return the number of PLT entries.
7241 unsigned int
7242 entry_count() const
7243 { return this->count_; }
7244
7245 // Return the offset of the first non-reserved PLT entry.
7246 unsigned int
7247 first_plt_entry_offset() const
7248 { return this->do_first_plt_entry_offset(); }
7249
7250 // Return the size of a PLT entry.
7251 unsigned int
7252 get_plt_entry_size() const
7253 { return this->do_get_plt_entry_size(); }
7254
7255 protected:
7256 // Fill in the first PLT entry.
7257 void
7258 fill_first_plt_entry(unsigned char* pov,
7259 Arm_address got_address,
7260 Arm_address plt_address)
7261 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7262
7263 void
7264 fill_plt_entry(unsigned char* pov,
7265 Arm_address got_address,
7266 Arm_address plt_address,
7267 unsigned int got_offset,
7268 unsigned int plt_offset)
7269 { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7270
7271 virtual unsigned int
7272 do_first_plt_entry_offset() const = 0;
7273
7274 virtual unsigned int
7275 do_get_plt_entry_size() const = 0;
7276
7277 virtual void
7278 do_fill_first_plt_entry(unsigned char* pov,
7279 Arm_address got_address,
7280 Arm_address plt_address) = 0;
7281
7282 virtual void
7283 do_fill_plt_entry(unsigned char* pov,
7284 Arm_address got_address,
7285 Arm_address plt_address,
7286 unsigned int got_offset,
7287 unsigned int plt_offset) = 0;
7288
7289 void
7290 do_adjust_output_section(Output_section* os);
7291
7292 // Write to a map file.
7293 void
7294 do_print_to_mapfile(Mapfile* mapfile) const
7295 { mapfile->print_output_data(this, _("** PLT")); }
7296
7297 private:
7298 // Set the final size.
7299 void
7300 set_final_data_size()
7301 {
7302 this->set_data_size(this->first_plt_entry_offset()
7303 + this->count_ * this->get_plt_entry_size());
7304 }
7305
7306 // Write out the PLT data.
7307 void
7308 do_write(Output_file*);
7309
7310 // The reloc section.
7311 Reloc_section* rel_;
7312 // The .got.plt section.
7313 Output_data_space* got_plt_;
7314 // The number of PLT entries.
7315 unsigned int count_;
7316 };
7317
7318 // Create the PLT section. The ordinary .got section is an argument,
7319 // since we need to refer to the start. We also create our own .got
7320 // section just for PLT entries.
7321
7322 template<bool big_endian>
7323 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7324 uint64_t addralign,
7325 Output_data_space* got_plt)
7326 : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7327 {
7328 this->rel_ = new Reloc_section(false);
7329 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7330 elfcpp::SHF_ALLOC, this->rel_,
7331 ORDER_DYNAMIC_PLT_RELOCS, false);
7332 }
7333
7334 template<bool big_endian>
7335 void
7336 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7337 {
7338 os->set_entsize(0);
7339 }
7340
7341 // Add an entry to the PLT.
7342
7343 template<bool big_endian>
7344 void
7345 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7346 {
7347 gold_assert(!gsym->has_plt_offset());
7348
7349 // Note that when setting the PLT offset we skip the initial
7350 // reserved PLT entry.
7351 gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7352 + this->first_plt_entry_offset());
7353
7354 ++this->count_;
7355
7356 section_offset_type got_offset = this->got_plt_->current_data_size();
7357
7358 // Every PLT entry needs a GOT entry which points back to the PLT
7359 // entry (this will be changed by the dynamic linker, normally
7360 // lazily when the function is called).
7361 this->got_plt_->set_current_data_size(got_offset + 4);
7362
7363 // Every PLT entry needs a reloc.
7364 gsym->set_needs_dynsym_entry();
7365 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7366 got_offset);
7367
7368 // Note that we don't need to save the symbol. The contents of the
7369 // PLT are independent of which symbols are used. The symbols only
7370 // appear in the relocations.
7371 }
7372
7373 template<bool big_endian>
7374 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7375 {
7376 public:
7377 Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7378 : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7379 { }
7380
7381 protected:
7382 // Return the offset of the first non-reserved PLT entry.
7383 virtual unsigned int
7384 do_first_plt_entry_offset() const
7385 { return sizeof(first_plt_entry); }
7386
7387 // Return the size of a PLT entry.
7388 virtual unsigned int
7389 do_get_plt_entry_size() const
7390 { return sizeof(plt_entry); }
7391
7392 virtual void
7393 do_fill_first_plt_entry(unsigned char* pov,
7394 Arm_address got_address,
7395 Arm_address plt_address);
7396
7397 virtual void
7398 do_fill_plt_entry(unsigned char* pov,
7399 Arm_address got_address,
7400 Arm_address plt_address,
7401 unsigned int got_offset,
7402 unsigned int plt_offset);
7403
7404 private:
7405 // Template for the first PLT entry.
7406 static const uint32_t first_plt_entry[5];
7407
7408 // Template for subsequent PLT entries.
7409 static const uint32_t plt_entry[3];
7410 };
7411
7412 // ARM PLTs.
7413 // FIXME: This is not very flexible. Right now this has only been tested
7414 // on armv5te. If we are to support additional architecture features like
7415 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7416
7417 // The first entry in the PLT.
7418 template<bool big_endian>
7419 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7420 {
7421 0xe52de004, // str lr, [sp, #-4]!
7422 0xe59fe004, // ldr lr, [pc, #4]
7423 0xe08fe00e, // add lr, pc, lr
7424 0xe5bef008, // ldr pc, [lr, #8]!
7425 0x00000000, // &GOT[0] - .
7426 };
7427
7428 template<bool big_endian>
7429 void
7430 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7431 unsigned char* pov,
7432 Arm_address got_address,
7433 Arm_address plt_address)
7434 {
7435 // Write first PLT entry. All but the last word are constants.
7436 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7437 / sizeof(plt_entry[0]));
7438 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7439 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7440 // Last word in first PLT entry is &GOT[0] - .
7441 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7442 got_address - (plt_address + 16));
7443 }
7444
7445 // Subsequent entries in the PLT.
7446
7447 template<bool big_endian>
7448 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7449 {
7450 0xe28fc600, // add ip, pc, #0xNN00000
7451 0xe28cca00, // add ip, ip, #0xNN000
7452 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7453 };
7454
7455 template<bool big_endian>
7456 void
7457 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7458 unsigned char* pov,
7459 Arm_address got_address,
7460 Arm_address plt_address,
7461 unsigned int got_offset,
7462 unsigned int plt_offset)
7463 {
7464 int32_t offset = ((got_address + got_offset)
7465 - (plt_address + plt_offset + 8));
7466
7467 gold_assert(offset >= 0 && offset < 0x0fffffff);
7468 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7469 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7470 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7471 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7472 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7473 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7474 }
7475
7476 // Write out the PLT. This uses the hand-coded instructions above,
7477 // and adjusts them as needed. This is all specified by the arm ELF
7478 // Processor Supplement.
7479
7480 template<bool big_endian>
7481 void
7482 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7483 {
7484 const off_t offset = this->offset();
7485 const section_size_type oview_size =
7486 convert_to_section_size_type(this->data_size());
7487 unsigned char* const oview = of->get_output_view(offset, oview_size);
7488
7489 const off_t got_file_offset = this->got_plt_->offset();
7490 const section_size_type got_size =
7491 convert_to_section_size_type(this->got_plt_->data_size());
7492 unsigned char* const got_view = of->get_output_view(got_file_offset,
7493 got_size);
7494 unsigned char* pov = oview;
7495
7496 Arm_address plt_address = this->address();
7497 Arm_address got_address = this->got_plt_->address();
7498
7499 // Write first PLT entry.
7500 this->fill_first_plt_entry(pov, got_address, plt_address);
7501 pov += this->first_plt_entry_offset();
7502
7503 unsigned char* got_pov = got_view;
7504
7505 memset(got_pov, 0, 12);
7506 got_pov += 12;
7507
7508 unsigned int plt_offset = this->first_plt_entry_offset();
7509 unsigned int got_offset = 12;
7510 const unsigned int count = this->count_;
7511 for (unsigned int i = 0;
7512 i < count;
7513 ++i,
7514 pov += this->get_plt_entry_size(),
7515 got_pov += 4,
7516 plt_offset += this->get_plt_entry_size(),
7517 got_offset += 4)
7518 {
7519 // Set and adjust the PLT entry itself.
7520 this->fill_plt_entry(pov, got_address, plt_address,
7521 got_offset, plt_offset);
7522
7523 // Set the entry in the GOT.
7524 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7525 }
7526
7527 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7528 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7529
7530 of->write_output_view(offset, oview_size, oview);
7531 of->write_output_view(got_file_offset, got_size, got_view);
7532 }
7533
7534 // Create a PLT entry for a global symbol.
7535
7536 template<bool big_endian>
7537 void
7538 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7539 Symbol* gsym)
7540 {
7541 if (gsym->has_plt_offset())
7542 return;
7543
7544 if (this->plt_ == NULL)
7545 {
7546 // Create the GOT sections first.
7547 this->got_section(symtab, layout);
7548
7549 this->plt_ = this->make_data_plt(layout, this->got_plt_);
7550
7551 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7552 (elfcpp::SHF_ALLOC
7553 | elfcpp::SHF_EXECINSTR),
7554 this->plt_, ORDER_PLT, false);
7555 }
7556 this->plt_->add_entry(gsym);
7557 }
7558
7559 // Return the number of entries in the PLT.
7560
7561 template<bool big_endian>
7562 unsigned int
7563 Target_arm<big_endian>::plt_entry_count() const
7564 {
7565 if (this->plt_ == NULL)
7566 return 0;
7567 return this->plt_->entry_count();
7568 }
7569
7570 // Return the offset of the first non-reserved PLT entry.
7571
7572 template<bool big_endian>
7573 unsigned int
7574 Target_arm<big_endian>::first_plt_entry_offset() const
7575 {
7576 return this->plt_->first_plt_entry_offset();
7577 }
7578
7579 // Return the size of each PLT entry.
7580
7581 template<bool big_endian>
7582 unsigned int
7583 Target_arm<big_endian>::plt_entry_size() const
7584 {
7585 return this->plt_->get_plt_entry_size();
7586 }
7587
7588 // Get the section to use for TLS_DESC relocations.
7589
7590 template<bool big_endian>
7591 typename Target_arm<big_endian>::Reloc_section*
7592 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7593 {
7594 return this->plt_section()->rel_tls_desc(layout);
7595 }
7596
7597 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7598
7599 template<bool big_endian>
7600 void
7601 Target_arm<big_endian>::define_tls_base_symbol(
7602 Symbol_table* symtab,
7603 Layout* layout)
7604 {
7605 if (this->tls_base_symbol_defined_)
7606 return;
7607
7608 Output_segment* tls_segment = layout->tls_segment();
7609 if (tls_segment != NULL)
7610 {
7611 bool is_exec = parameters->options().output_is_executable();
7612 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7613 Symbol_table::PREDEFINED,
7614 tls_segment, 0, 0,
7615 elfcpp::STT_TLS,
7616 elfcpp::STB_LOCAL,
7617 elfcpp::STV_HIDDEN, 0,
7618 (is_exec
7619 ? Symbol::SEGMENT_END
7620 : Symbol::SEGMENT_START),
7621 true);
7622 }
7623 this->tls_base_symbol_defined_ = true;
7624 }
7625
7626 // Create a GOT entry for the TLS module index.
7627
7628 template<bool big_endian>
7629 unsigned int
7630 Target_arm<big_endian>::got_mod_index_entry(
7631 Symbol_table* symtab,
7632 Layout* layout,
7633 Sized_relobj_file<32, big_endian>* object)
7634 {
7635 if (this->got_mod_index_offset_ == -1U)
7636 {
7637 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7638 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7639 unsigned int got_offset;
7640 if (!parameters->doing_static_link())
7641 {
7642 got_offset = got->add_constant(0);
7643 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7644 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7645 got_offset);
7646 }
7647 else
7648 {
7649 // We are doing a static link. Just mark it as belong to module 1,
7650 // the executable.
7651 got_offset = got->add_constant(1);
7652 }
7653
7654 got->add_constant(0);
7655 this->got_mod_index_offset_ = got_offset;
7656 }
7657 return this->got_mod_index_offset_;
7658 }
7659
7660 // Optimize the TLS relocation type based on what we know about the
7661 // symbol. IS_FINAL is true if the final address of this symbol is
7662 // known at link time.
7663
7664 template<bool big_endian>
7665 tls::Tls_optimization
7666 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7667 {
7668 // FIXME: Currently we do not do any TLS optimization.
7669 return tls::TLSOPT_NONE;
7670 }
7671
7672 // Get the Reference_flags for a particular relocation.
7673
7674 template<bool big_endian>
7675 int
7676 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7677 {
7678 switch (r_type)
7679 {
7680 case elfcpp::R_ARM_NONE:
7681 case elfcpp::R_ARM_V4BX:
7682 case elfcpp::R_ARM_GNU_VTENTRY:
7683 case elfcpp::R_ARM_GNU_VTINHERIT:
7684 // No symbol reference.
7685 return 0;
7686
7687 case elfcpp::R_ARM_ABS32:
7688 case elfcpp::R_ARM_ABS16:
7689 case elfcpp::R_ARM_ABS12:
7690 case elfcpp::R_ARM_THM_ABS5:
7691 case elfcpp::R_ARM_ABS8:
7692 case elfcpp::R_ARM_BASE_ABS:
7693 case elfcpp::R_ARM_MOVW_ABS_NC:
7694 case elfcpp::R_ARM_MOVT_ABS:
7695 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7696 case elfcpp::R_ARM_THM_MOVT_ABS:
7697 case elfcpp::R_ARM_ABS32_NOI:
7698 return Symbol::ABSOLUTE_REF;
7699
7700 case elfcpp::R_ARM_REL32:
7701 case elfcpp::R_ARM_LDR_PC_G0:
7702 case elfcpp::R_ARM_SBREL32:
7703 case elfcpp::R_ARM_THM_PC8:
7704 case elfcpp::R_ARM_BASE_PREL:
7705 case elfcpp::R_ARM_MOVW_PREL_NC:
7706 case elfcpp::R_ARM_MOVT_PREL:
7707 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7708 case elfcpp::R_ARM_THM_MOVT_PREL:
7709 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7710 case elfcpp::R_ARM_THM_PC12:
7711 case elfcpp::R_ARM_REL32_NOI:
7712 case elfcpp::R_ARM_ALU_PC_G0_NC:
7713 case elfcpp::R_ARM_ALU_PC_G0:
7714 case elfcpp::R_ARM_ALU_PC_G1_NC:
7715 case elfcpp::R_ARM_ALU_PC_G1:
7716 case elfcpp::R_ARM_ALU_PC_G2:
7717 case elfcpp::R_ARM_LDR_PC_G1:
7718 case elfcpp::R_ARM_LDR_PC_G2:
7719 case elfcpp::R_ARM_LDRS_PC_G0:
7720 case elfcpp::R_ARM_LDRS_PC_G1:
7721 case elfcpp::R_ARM_LDRS_PC_G2:
7722 case elfcpp::R_ARM_LDC_PC_G0:
7723 case elfcpp::R_ARM_LDC_PC_G1:
7724 case elfcpp::R_ARM_LDC_PC_G2:
7725 case elfcpp::R_ARM_ALU_SB_G0_NC:
7726 case elfcpp::R_ARM_ALU_SB_G0:
7727 case elfcpp::R_ARM_ALU_SB_G1_NC:
7728 case elfcpp::R_ARM_ALU_SB_G1:
7729 case elfcpp::R_ARM_ALU_SB_G2:
7730 case elfcpp::R_ARM_LDR_SB_G0:
7731 case elfcpp::R_ARM_LDR_SB_G1:
7732 case elfcpp::R_ARM_LDR_SB_G2:
7733 case elfcpp::R_ARM_LDRS_SB_G0:
7734 case elfcpp::R_ARM_LDRS_SB_G1:
7735 case elfcpp::R_ARM_LDRS_SB_G2:
7736 case elfcpp::R_ARM_LDC_SB_G0:
7737 case elfcpp::R_ARM_LDC_SB_G1:
7738 case elfcpp::R_ARM_LDC_SB_G2:
7739 case elfcpp::R_ARM_MOVW_BREL_NC:
7740 case elfcpp::R_ARM_MOVT_BREL:
7741 case elfcpp::R_ARM_MOVW_BREL:
7742 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7743 case elfcpp::R_ARM_THM_MOVT_BREL:
7744 case elfcpp::R_ARM_THM_MOVW_BREL:
7745 case elfcpp::R_ARM_GOTOFF32:
7746 case elfcpp::R_ARM_GOTOFF12:
7747 case elfcpp::R_ARM_SBREL31:
7748 return Symbol::RELATIVE_REF;
7749
7750 case elfcpp::R_ARM_PLT32:
7751 case elfcpp::R_ARM_CALL:
7752 case elfcpp::R_ARM_JUMP24:
7753 case elfcpp::R_ARM_THM_CALL:
7754 case elfcpp::R_ARM_THM_JUMP24:
7755 case elfcpp::R_ARM_THM_JUMP19:
7756 case elfcpp::R_ARM_THM_JUMP6:
7757 case elfcpp::R_ARM_THM_JUMP11:
7758 case elfcpp::R_ARM_THM_JUMP8:
7759 // R_ARM_PREL31 is not used to relocate call/jump instructions but
7760 // in unwind tables. It may point to functions via PLTs.
7761 // So we treat it like call/jump relocations above.
7762 case elfcpp::R_ARM_PREL31:
7763 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7764
7765 case elfcpp::R_ARM_GOT_BREL:
7766 case elfcpp::R_ARM_GOT_ABS:
7767 case elfcpp::R_ARM_GOT_PREL:
7768 // Absolute in GOT.
7769 return Symbol::ABSOLUTE_REF;
7770
7771 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7772 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7773 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7774 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7775 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7776 return Symbol::TLS_REF;
7777
7778 case elfcpp::R_ARM_TARGET1:
7779 case elfcpp::R_ARM_TARGET2:
7780 case elfcpp::R_ARM_COPY:
7781 case elfcpp::R_ARM_GLOB_DAT:
7782 case elfcpp::R_ARM_JUMP_SLOT:
7783 case elfcpp::R_ARM_RELATIVE:
7784 case elfcpp::R_ARM_PC24:
7785 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7786 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7787 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7788 default:
7789 // Not expected. We will give an error later.
7790 return 0;
7791 }
7792 }
7793
7794 // Report an unsupported relocation against a local symbol.
7795
7796 template<bool big_endian>
7797 void
7798 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7799 Sized_relobj_file<32, big_endian>* object,
7800 unsigned int r_type)
7801 {
7802 gold_error(_("%s: unsupported reloc %u against local symbol"),
7803 object->name().c_str(), r_type);
7804 }
7805
7806 // We are about to emit a dynamic relocation of type R_TYPE. If the
7807 // dynamic linker does not support it, issue an error. The GNU linker
7808 // only issues a non-PIC error for an allocated read-only section.
7809 // Here we know the section is allocated, but we don't know that it is
7810 // read-only. But we check for all the relocation types which the
7811 // glibc dynamic linker supports, so it seems appropriate to issue an
7812 // error even if the section is not read-only.
7813
7814 template<bool big_endian>
7815 void
7816 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7817 unsigned int r_type)
7818 {
7819 switch (r_type)
7820 {
7821 // These are the relocation types supported by glibc for ARM.
7822 case elfcpp::R_ARM_RELATIVE:
7823 case elfcpp::R_ARM_COPY:
7824 case elfcpp::R_ARM_GLOB_DAT:
7825 case elfcpp::R_ARM_JUMP_SLOT:
7826 case elfcpp::R_ARM_ABS32:
7827 case elfcpp::R_ARM_ABS32_NOI:
7828 case elfcpp::R_ARM_PC24:
7829 // FIXME: The following 3 types are not supported by Android's dynamic
7830 // linker.
7831 case elfcpp::R_ARM_TLS_DTPMOD32:
7832 case elfcpp::R_ARM_TLS_DTPOFF32:
7833 case elfcpp::R_ARM_TLS_TPOFF32:
7834 return;
7835
7836 default:
7837 {
7838 // This prevents us from issuing more than one error per reloc
7839 // section. But we can still wind up issuing more than one
7840 // error per object file.
7841 if (this->issued_non_pic_error_)
7842 return;
7843 const Arm_reloc_property* reloc_property =
7844 arm_reloc_property_table->get_reloc_property(r_type);
7845 gold_assert(reloc_property != NULL);
7846 object->error(_("requires unsupported dynamic reloc %s; "
7847 "recompile with -fPIC"),
7848 reloc_property->name().c_str());
7849 this->issued_non_pic_error_ = true;
7850 return;
7851 }
7852
7853 case elfcpp::R_ARM_NONE:
7854 gold_unreachable();
7855 }
7856 }
7857
7858 // Scan a relocation for a local symbol.
7859 // FIXME: This only handles a subset of relocation types used by Android
7860 // on ARM v5te devices.
7861
7862 template<bool big_endian>
7863 inline void
7864 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7865 Layout* layout,
7866 Target_arm* target,
7867 Sized_relobj_file<32, big_endian>* object,
7868 unsigned int data_shndx,
7869 Output_section* output_section,
7870 const elfcpp::Rel<32, big_endian>& reloc,
7871 unsigned int r_type,
7872 const elfcpp::Sym<32, big_endian>& lsym,
7873 bool is_discarded)
7874 {
7875 if (is_discarded)
7876 return;
7877
7878 r_type = get_real_reloc_type(r_type);
7879 switch (r_type)
7880 {
7881 case elfcpp::R_ARM_NONE:
7882 case elfcpp::R_ARM_V4BX:
7883 case elfcpp::R_ARM_GNU_VTENTRY:
7884 case elfcpp::R_ARM_GNU_VTINHERIT:
7885 break;
7886
7887 case elfcpp::R_ARM_ABS32:
7888 case elfcpp::R_ARM_ABS32_NOI:
7889 // If building a shared library (or a position-independent
7890 // executable), we need to create a dynamic relocation for
7891 // this location. The relocation applied at link time will
7892 // apply the link-time value, so we flag the location with
7893 // an R_ARM_RELATIVE relocation so the dynamic loader can
7894 // relocate it easily.
7895 if (parameters->options().output_is_position_independent())
7896 {
7897 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7898 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7899 // If we are to add more other reloc types than R_ARM_ABS32,
7900 // we need to add check_non_pic(object, r_type) here.
7901 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7902 output_section, data_shndx,
7903 reloc.get_r_offset());
7904 }
7905 break;
7906
7907 case elfcpp::R_ARM_ABS16:
7908 case elfcpp::R_ARM_ABS12:
7909 case elfcpp::R_ARM_THM_ABS5:
7910 case elfcpp::R_ARM_ABS8:
7911 case elfcpp::R_ARM_BASE_ABS:
7912 case elfcpp::R_ARM_MOVW_ABS_NC:
7913 case elfcpp::R_ARM_MOVT_ABS:
7914 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7915 case elfcpp::R_ARM_THM_MOVT_ABS:
7916 // If building a shared library (or a position-independent
7917 // executable), we need to create a dynamic relocation for
7918 // this location. Because the addend needs to remain in the
7919 // data section, we need to be careful not to apply this
7920 // relocation statically.
7921 if (parameters->options().output_is_position_independent())
7922 {
7923 check_non_pic(object, r_type);
7924 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7925 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7926 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7927 rel_dyn->add_local(object, r_sym, r_type, output_section,
7928 data_shndx, reloc.get_r_offset());
7929 else
7930 {
7931 gold_assert(lsym.get_st_value() == 0);
7932 unsigned int shndx = lsym.get_st_shndx();
7933 bool is_ordinary;
7934 shndx = object->adjust_sym_shndx(r_sym, shndx,
7935 &is_ordinary);
7936 if (!is_ordinary)
7937 object->error(_("section symbol %u has bad shndx %u"),
7938 r_sym, shndx);
7939 else
7940 rel_dyn->add_local_section(object, shndx,
7941 r_type, output_section,
7942 data_shndx, reloc.get_r_offset());
7943 }
7944 }
7945 break;
7946
7947 case elfcpp::R_ARM_REL32:
7948 case elfcpp::R_ARM_LDR_PC_G0:
7949 case elfcpp::R_ARM_SBREL32:
7950 case elfcpp::R_ARM_THM_CALL:
7951 case elfcpp::R_ARM_THM_PC8:
7952 case elfcpp::R_ARM_BASE_PREL:
7953 case elfcpp::R_ARM_PLT32:
7954 case elfcpp::R_ARM_CALL:
7955 case elfcpp::R_ARM_JUMP24:
7956 case elfcpp::R_ARM_THM_JUMP24:
7957 case elfcpp::R_ARM_SBREL31:
7958 case elfcpp::R_ARM_PREL31:
7959 case elfcpp::R_ARM_MOVW_PREL_NC:
7960 case elfcpp::R_ARM_MOVT_PREL:
7961 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7962 case elfcpp::R_ARM_THM_MOVT_PREL:
7963 case elfcpp::R_ARM_THM_JUMP19:
7964 case elfcpp::R_ARM_THM_JUMP6:
7965 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7966 case elfcpp::R_ARM_THM_PC12:
7967 case elfcpp::R_ARM_REL32_NOI:
7968 case elfcpp::R_ARM_ALU_PC_G0_NC:
7969 case elfcpp::R_ARM_ALU_PC_G0:
7970 case elfcpp::R_ARM_ALU_PC_G1_NC:
7971 case elfcpp::R_ARM_ALU_PC_G1:
7972 case elfcpp::R_ARM_ALU_PC_G2:
7973 case elfcpp::R_ARM_LDR_PC_G1:
7974 case elfcpp::R_ARM_LDR_PC_G2:
7975 case elfcpp::R_ARM_LDRS_PC_G0:
7976 case elfcpp::R_ARM_LDRS_PC_G1:
7977 case elfcpp::R_ARM_LDRS_PC_G2:
7978 case elfcpp::R_ARM_LDC_PC_G0:
7979 case elfcpp::R_ARM_LDC_PC_G1:
7980 case elfcpp::R_ARM_LDC_PC_G2:
7981 case elfcpp::R_ARM_ALU_SB_G0_NC:
7982 case elfcpp::R_ARM_ALU_SB_G0:
7983 case elfcpp::R_ARM_ALU_SB_G1_NC:
7984 case elfcpp::R_ARM_ALU_SB_G1:
7985 case elfcpp::R_ARM_ALU_SB_G2:
7986 case elfcpp::R_ARM_LDR_SB_G0:
7987 case elfcpp::R_ARM_LDR_SB_G1:
7988 case elfcpp::R_ARM_LDR_SB_G2:
7989 case elfcpp::R_ARM_LDRS_SB_G0:
7990 case elfcpp::R_ARM_LDRS_SB_G1:
7991 case elfcpp::R_ARM_LDRS_SB_G2:
7992 case elfcpp::R_ARM_LDC_SB_G0:
7993 case elfcpp::R_ARM_LDC_SB_G1:
7994 case elfcpp::R_ARM_LDC_SB_G2:
7995 case elfcpp::R_ARM_MOVW_BREL_NC:
7996 case elfcpp::R_ARM_MOVT_BREL:
7997 case elfcpp::R_ARM_MOVW_BREL:
7998 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7999 case elfcpp::R_ARM_THM_MOVT_BREL:
8000 case elfcpp::R_ARM_THM_MOVW_BREL:
8001 case elfcpp::R_ARM_THM_JUMP11:
8002 case elfcpp::R_ARM_THM_JUMP8:
8003 // We don't need to do anything for a relative addressing relocation
8004 // against a local symbol if it does not reference the GOT.
8005 break;
8006
8007 case elfcpp::R_ARM_GOTOFF32:
8008 case elfcpp::R_ARM_GOTOFF12:
8009 // We need a GOT section:
8010 target->got_section(symtab, layout);
8011 break;
8012
8013 case elfcpp::R_ARM_GOT_BREL:
8014 case elfcpp::R_ARM_GOT_PREL:
8015 {
8016 // The symbol requires a GOT entry.
8017 Arm_output_data_got<big_endian>* got =
8018 target->got_section(symtab, layout);
8019 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8020 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8021 {
8022 // If we are generating a shared object, we need to add a
8023 // dynamic RELATIVE relocation for this symbol's GOT entry.
8024 if (parameters->options().output_is_position_independent())
8025 {
8026 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8027 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8028 rel_dyn->add_local_relative(
8029 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8030 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8031 }
8032 }
8033 }
8034 break;
8035
8036 case elfcpp::R_ARM_TARGET1:
8037 case elfcpp::R_ARM_TARGET2:
8038 // This should have been mapped to another type already.
8039 // Fall through.
8040 case elfcpp::R_ARM_COPY:
8041 case elfcpp::R_ARM_GLOB_DAT:
8042 case elfcpp::R_ARM_JUMP_SLOT:
8043 case elfcpp::R_ARM_RELATIVE:
8044 // These are relocations which should only be seen by the
8045 // dynamic linker, and should never be seen here.
8046 gold_error(_("%s: unexpected reloc %u in object file"),
8047 object->name().c_str(), r_type);
8048 break;
8049
8050
8051 // These are initial TLS relocs, which are expected when
8052 // linking.
8053 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8054 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8055 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8056 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8057 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8058 {
8059 bool output_is_shared = parameters->options().shared();
8060 const tls::Tls_optimization optimized_type
8061 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8062 r_type);
8063 switch (r_type)
8064 {
8065 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8066 if (optimized_type == tls::TLSOPT_NONE)
8067 {
8068 // Create a pair of GOT entries for the module index and
8069 // dtv-relative offset.
8070 Arm_output_data_got<big_endian>* got
8071 = target->got_section(symtab, layout);
8072 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8073 unsigned int shndx = lsym.get_st_shndx();
8074 bool is_ordinary;
8075 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8076 if (!is_ordinary)
8077 {
8078 object->error(_("local symbol %u has bad shndx %u"),
8079 r_sym, shndx);
8080 break;
8081 }
8082
8083 if (!parameters->doing_static_link())
8084 got->add_local_pair_with_rel(object, r_sym, shndx,
8085 GOT_TYPE_TLS_PAIR,
8086 target->rel_dyn_section(layout),
8087 elfcpp::R_ARM_TLS_DTPMOD32);
8088 else
8089 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8090 object, r_sym);
8091 }
8092 else
8093 // FIXME: TLS optimization not supported yet.
8094 gold_unreachable();
8095 break;
8096
8097 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8098 if (optimized_type == tls::TLSOPT_NONE)
8099 {
8100 // Create a GOT entry for the module index.
8101 target->got_mod_index_entry(symtab, layout, object);
8102 }
8103 else
8104 // FIXME: TLS optimization not supported yet.
8105 gold_unreachable();
8106 break;
8107
8108 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8109 break;
8110
8111 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8112 layout->set_has_static_tls();
8113 if (optimized_type == tls::TLSOPT_NONE)
8114 {
8115 // Create a GOT entry for the tp-relative offset.
8116 Arm_output_data_got<big_endian>* got
8117 = target->got_section(symtab, layout);
8118 unsigned int r_sym =
8119 elfcpp::elf_r_sym<32>(reloc.get_r_info());
8120 if (!parameters->doing_static_link())
8121 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8122 target->rel_dyn_section(layout),
8123 elfcpp::R_ARM_TLS_TPOFF32);
8124 else if (!object->local_has_got_offset(r_sym,
8125 GOT_TYPE_TLS_OFFSET))
8126 {
8127 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8128 unsigned int got_offset =
8129 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8130 got->add_static_reloc(got_offset,
8131 elfcpp::R_ARM_TLS_TPOFF32, object,
8132 r_sym);
8133 }
8134 }
8135 else
8136 // FIXME: TLS optimization not supported yet.
8137 gold_unreachable();
8138 break;
8139
8140 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8141 layout->set_has_static_tls();
8142 if (output_is_shared)
8143 {
8144 // We need to create a dynamic relocation.
8145 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8146 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8147 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8148 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8149 output_section, data_shndx,
8150 reloc.get_r_offset());
8151 }
8152 break;
8153
8154 default:
8155 gold_unreachable();
8156 }
8157 }
8158 break;
8159
8160 case elfcpp::R_ARM_PC24:
8161 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8162 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8163 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8164 default:
8165 unsupported_reloc_local(object, r_type);
8166 break;
8167 }
8168 }
8169
8170 // Report an unsupported relocation against a global symbol.
8171
8172 template<bool big_endian>
8173 void
8174 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8175 Sized_relobj_file<32, big_endian>* object,
8176 unsigned int r_type,
8177 Symbol* gsym)
8178 {
8179 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8180 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8181 }
8182
8183 template<bool big_endian>
8184 inline bool
8185 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8186 unsigned int r_type)
8187 {
8188 switch (r_type)
8189 {
8190 case elfcpp::R_ARM_PC24:
8191 case elfcpp::R_ARM_THM_CALL:
8192 case elfcpp::R_ARM_PLT32:
8193 case elfcpp::R_ARM_CALL:
8194 case elfcpp::R_ARM_JUMP24:
8195 case elfcpp::R_ARM_THM_JUMP24:
8196 case elfcpp::R_ARM_SBREL31:
8197 case elfcpp::R_ARM_PREL31:
8198 case elfcpp::R_ARM_THM_JUMP19:
8199 case elfcpp::R_ARM_THM_JUMP6:
8200 case elfcpp::R_ARM_THM_JUMP11:
8201 case elfcpp::R_ARM_THM_JUMP8:
8202 // All the relocations above are branches except SBREL31 and PREL31.
8203 return false;
8204
8205 default:
8206 // Be conservative and assume this is a function pointer.
8207 return true;
8208 }
8209 }
8210
8211 template<bool big_endian>
8212 inline bool
8213 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8214 Symbol_table*,
8215 Layout*,
8216 Target_arm<big_endian>* target,
8217 Sized_relobj_file<32, big_endian>*,
8218 unsigned int,
8219 Output_section*,
8220 const elfcpp::Rel<32, big_endian>&,
8221 unsigned int r_type,
8222 const elfcpp::Sym<32, big_endian>&)
8223 {
8224 r_type = target->get_real_reloc_type(r_type);
8225 return possible_function_pointer_reloc(r_type);
8226 }
8227
8228 template<bool big_endian>
8229 inline bool
8230 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8231 Symbol_table*,
8232 Layout*,
8233 Target_arm<big_endian>* target,
8234 Sized_relobj_file<32, big_endian>*,
8235 unsigned int,
8236 Output_section*,
8237 const elfcpp::Rel<32, big_endian>&,
8238 unsigned int r_type,
8239 Symbol* gsym)
8240 {
8241 // GOT is not a function.
8242 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8243 return false;
8244
8245 r_type = target->get_real_reloc_type(r_type);
8246 return possible_function_pointer_reloc(r_type);
8247 }
8248
8249 // Scan a relocation for a global symbol.
8250
8251 template<bool big_endian>
8252 inline void
8253 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8254 Layout* layout,
8255 Target_arm* target,
8256 Sized_relobj_file<32, big_endian>* object,
8257 unsigned int data_shndx,
8258 Output_section* output_section,
8259 const elfcpp::Rel<32, big_endian>& reloc,
8260 unsigned int r_type,
8261 Symbol* gsym)
8262 {
8263 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8264 // section. We check here to avoid creating a dynamic reloc against
8265 // _GLOBAL_OFFSET_TABLE_.
8266 if (!target->has_got_section()
8267 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8268 target->got_section(symtab, layout);
8269
8270 r_type = get_real_reloc_type(r_type);
8271 switch (r_type)
8272 {
8273 case elfcpp::R_ARM_NONE:
8274 case elfcpp::R_ARM_V4BX:
8275 case elfcpp::R_ARM_GNU_VTENTRY:
8276 case elfcpp::R_ARM_GNU_VTINHERIT:
8277 break;
8278
8279 case elfcpp::R_ARM_ABS32:
8280 case elfcpp::R_ARM_ABS16:
8281 case elfcpp::R_ARM_ABS12:
8282 case elfcpp::R_ARM_THM_ABS5:
8283 case elfcpp::R_ARM_ABS8:
8284 case elfcpp::R_ARM_BASE_ABS:
8285 case elfcpp::R_ARM_MOVW_ABS_NC:
8286 case elfcpp::R_ARM_MOVT_ABS:
8287 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8288 case elfcpp::R_ARM_THM_MOVT_ABS:
8289 case elfcpp::R_ARM_ABS32_NOI:
8290 // Absolute addressing relocations.
8291 {
8292 // Make a PLT entry if necessary.
8293 if (this->symbol_needs_plt_entry(gsym))
8294 {
8295 target->make_plt_entry(symtab, layout, gsym);
8296 // Since this is not a PC-relative relocation, we may be
8297 // taking the address of a function. In that case we need to
8298 // set the entry in the dynamic symbol table to the address of
8299 // the PLT entry.
8300 if (gsym->is_from_dynobj() && !parameters->options().shared())
8301 gsym->set_needs_dynsym_value();
8302 }
8303 // Make a dynamic relocation if necessary.
8304 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8305 {
8306 if (gsym->may_need_copy_reloc())
8307 {
8308 target->copy_reloc(symtab, layout, object,
8309 data_shndx, output_section, gsym, reloc);
8310 }
8311 else if ((r_type == elfcpp::R_ARM_ABS32
8312 || r_type == elfcpp::R_ARM_ABS32_NOI)
8313 && gsym->can_use_relative_reloc(false))
8314 {
8315 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8316 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8317 output_section, object,
8318 data_shndx, reloc.get_r_offset());
8319 }
8320 else
8321 {
8322 check_non_pic(object, r_type);
8323 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8324 rel_dyn->add_global(gsym, r_type, output_section, object,
8325 data_shndx, reloc.get_r_offset());
8326 }
8327 }
8328 }
8329 break;
8330
8331 case elfcpp::R_ARM_GOTOFF32:
8332 case elfcpp::R_ARM_GOTOFF12:
8333 // We need a GOT section.
8334 target->got_section(symtab, layout);
8335 break;
8336
8337 case elfcpp::R_ARM_REL32:
8338 case elfcpp::R_ARM_LDR_PC_G0:
8339 case elfcpp::R_ARM_SBREL32:
8340 case elfcpp::R_ARM_THM_PC8:
8341 case elfcpp::R_ARM_BASE_PREL:
8342 case elfcpp::R_ARM_MOVW_PREL_NC:
8343 case elfcpp::R_ARM_MOVT_PREL:
8344 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8345 case elfcpp::R_ARM_THM_MOVT_PREL:
8346 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8347 case elfcpp::R_ARM_THM_PC12:
8348 case elfcpp::R_ARM_REL32_NOI:
8349 case elfcpp::R_ARM_ALU_PC_G0_NC:
8350 case elfcpp::R_ARM_ALU_PC_G0:
8351 case elfcpp::R_ARM_ALU_PC_G1_NC:
8352 case elfcpp::R_ARM_ALU_PC_G1:
8353 case elfcpp::R_ARM_ALU_PC_G2:
8354 case elfcpp::R_ARM_LDR_PC_G1:
8355 case elfcpp::R_ARM_LDR_PC_G2:
8356 case elfcpp::R_ARM_LDRS_PC_G0:
8357 case elfcpp::R_ARM_LDRS_PC_G1:
8358 case elfcpp::R_ARM_LDRS_PC_G2:
8359 case elfcpp::R_ARM_LDC_PC_G0:
8360 case elfcpp::R_ARM_LDC_PC_G1:
8361 case elfcpp::R_ARM_LDC_PC_G2:
8362 case elfcpp::R_ARM_ALU_SB_G0_NC:
8363 case elfcpp::R_ARM_ALU_SB_G0:
8364 case elfcpp::R_ARM_ALU_SB_G1_NC:
8365 case elfcpp::R_ARM_ALU_SB_G1:
8366 case elfcpp::R_ARM_ALU_SB_G2:
8367 case elfcpp::R_ARM_LDR_SB_G0:
8368 case elfcpp::R_ARM_LDR_SB_G1:
8369 case elfcpp::R_ARM_LDR_SB_G2:
8370 case elfcpp::R_ARM_LDRS_SB_G0:
8371 case elfcpp::R_ARM_LDRS_SB_G1:
8372 case elfcpp::R_ARM_LDRS_SB_G2:
8373 case elfcpp::R_ARM_LDC_SB_G0:
8374 case elfcpp::R_ARM_LDC_SB_G1:
8375 case elfcpp::R_ARM_LDC_SB_G2:
8376 case elfcpp::R_ARM_MOVW_BREL_NC:
8377 case elfcpp::R_ARM_MOVT_BREL:
8378 case elfcpp::R_ARM_MOVW_BREL:
8379 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8380 case elfcpp::R_ARM_THM_MOVT_BREL:
8381 case elfcpp::R_ARM_THM_MOVW_BREL:
8382 // Relative addressing relocations.
8383 {
8384 // Make a dynamic relocation if necessary.
8385 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8386 {
8387 if (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())
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() == 0)
10497 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10498 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10499 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10500 && parameters->options().warn_mismatch())
10501 gold_error(_("%s uses VFP register arguments, output does not"),
10502 name);
10503 }
10504
10505 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10506 {
10507 // Merge this attribute with existing attributes.
10508 switch (i)
10509 {
10510 case elfcpp::Tag_CPU_raw_name:
10511 case elfcpp::Tag_CPU_name:
10512 // These are merged after Tag_CPU_arch.
10513 break;
10514
10515 case elfcpp::Tag_ABI_optimization_goals:
10516 case elfcpp::Tag_ABI_FP_optimization_goals:
10517 // Use the first value seen.
10518 break;
10519
10520 case elfcpp::Tag_CPU_arch:
10521 {
10522 unsigned int saved_out_attr = out_attr->int_value();
10523 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10524 int secondary_compat =
10525 this->get_secondary_compatible_arch(pasd);
10526 int secondary_compat_out =
10527 this->get_secondary_compatible_arch(
10528 this->attributes_section_data_);
10529 out_attr[i].set_int_value(
10530 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10531 &secondary_compat_out,
10532 in_attr[i].int_value(),
10533 secondary_compat));
10534 this->set_secondary_compatible_arch(this->attributes_section_data_,
10535 secondary_compat_out);
10536
10537 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10538 if (out_attr[i].int_value() == saved_out_attr)
10539 ; // Leave the names alone.
10540 else if (out_attr[i].int_value() == in_attr[i].int_value())
10541 {
10542 // The output architecture has been changed to match the
10543 // input architecture. Use the input names.
10544 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10545 in_attr[elfcpp::Tag_CPU_name].string_value());
10546 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10547 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10548 }
10549 else
10550 {
10551 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10552 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10553 }
10554
10555 // If we still don't have a value for Tag_CPU_name,
10556 // make one up now. Tag_CPU_raw_name remains blank.
10557 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10558 {
10559 const std::string cpu_name =
10560 this->tag_cpu_name_value(out_attr[i].int_value());
10561 // FIXME: If we see an unknown CPU, this will be set
10562 // to "<unknown CPU n>", where n is the attribute value.
10563 // This is different from BFD, which leaves the name alone.
10564 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10565 }
10566 }
10567 break;
10568
10569 case elfcpp::Tag_ARM_ISA_use:
10570 case elfcpp::Tag_THUMB_ISA_use:
10571 case elfcpp::Tag_WMMX_arch:
10572 case elfcpp::Tag_Advanced_SIMD_arch:
10573 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10574 case elfcpp::Tag_ABI_FP_rounding:
10575 case elfcpp::Tag_ABI_FP_exceptions:
10576 case elfcpp::Tag_ABI_FP_user_exceptions:
10577 case elfcpp::Tag_ABI_FP_number_model:
10578 case elfcpp::Tag_VFP_HP_extension:
10579 case elfcpp::Tag_CPU_unaligned_access:
10580 case elfcpp::Tag_T2EE_use:
10581 case elfcpp::Tag_Virtualization_use:
10582 case elfcpp::Tag_MPextension_use:
10583 // Use the largest value specified.
10584 if (in_attr[i].int_value() > out_attr[i].int_value())
10585 out_attr[i].set_int_value(in_attr[i].int_value());
10586 break;
10587
10588 case elfcpp::Tag_ABI_align8_preserved:
10589 case elfcpp::Tag_ABI_PCS_RO_data:
10590 // Use the smallest value specified.
10591 if (in_attr[i].int_value() < out_attr[i].int_value())
10592 out_attr[i].set_int_value(in_attr[i].int_value());
10593 break;
10594
10595 case elfcpp::Tag_ABI_align8_needed:
10596 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10597 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10598 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10599 == 0)))
10600 {
10601 // This error message should be enabled once all non-conforming
10602 // binaries in the toolchain have had the attributes set
10603 // properly.
10604 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10605 // name);
10606 }
10607 // Fall through.
10608 case elfcpp::Tag_ABI_FP_denormal:
10609 case elfcpp::Tag_ABI_PCS_GOT_use:
10610 {
10611 // These tags have 0 = don't care, 1 = strong requirement,
10612 // 2 = weak requirement.
10613 static const int order_021[3] = {0, 2, 1};
10614
10615 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10616 // value if greater than 2 (for future-proofing).
10617 if ((in_attr[i].int_value() > 2
10618 && in_attr[i].int_value() > out_attr[i].int_value())
10619 || (in_attr[i].int_value() <= 2
10620 && out_attr[i].int_value() <= 2
10621 && (order_021[in_attr[i].int_value()]
10622 > order_021[out_attr[i].int_value()])))
10623 out_attr[i].set_int_value(in_attr[i].int_value());
10624 }
10625 break;
10626
10627 case elfcpp::Tag_CPU_arch_profile:
10628 if (out_attr[i].int_value() != in_attr[i].int_value())
10629 {
10630 // 0 will merge with anything.
10631 // 'A' and 'S' merge to 'A'.
10632 // 'R' and 'S' merge to 'R'.
10633 // 'M' and 'A|R|S' is an error.
10634 if (out_attr[i].int_value() == 0
10635 || (out_attr[i].int_value() == 'S'
10636 && (in_attr[i].int_value() == 'A'
10637 || in_attr[i].int_value() == 'R')))
10638 out_attr[i].set_int_value(in_attr[i].int_value());
10639 else if (in_attr[i].int_value() == 0
10640 || (in_attr[i].int_value() == 'S'
10641 && (out_attr[i].int_value() == 'A'
10642 || out_attr[i].int_value() == 'R')))
10643 ; // Do nothing.
10644 else if (parameters->options().warn_mismatch())
10645 {
10646 gold_error
10647 (_("conflicting architecture profiles %c/%c"),
10648 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10649 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10650 }
10651 }
10652 break;
10653 case elfcpp::Tag_VFP_arch:
10654 {
10655 static const struct
10656 {
10657 int ver;
10658 int regs;
10659 } vfp_versions[7] =
10660 {
10661 {0, 0},
10662 {1, 16},
10663 {2, 16},
10664 {3, 32},
10665 {3, 16},
10666 {4, 32},
10667 {4, 16}
10668 };
10669
10670 // Values greater than 6 aren't defined, so just pick the
10671 // biggest.
10672 if (in_attr[i].int_value() > 6
10673 && in_attr[i].int_value() > out_attr[i].int_value())
10674 {
10675 *out_attr = *in_attr;
10676 break;
10677 }
10678 // The output uses the superset of input features
10679 // (ISA version) and registers.
10680 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10681 vfp_versions[out_attr[i].int_value()].ver);
10682 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10683 vfp_versions[out_attr[i].int_value()].regs);
10684 // This assumes all possible supersets are also a valid
10685 // options.
10686 int newval;
10687 for (newval = 6; newval > 0; newval--)
10688 {
10689 if (regs == vfp_versions[newval].regs
10690 && ver == vfp_versions[newval].ver)
10691 break;
10692 }
10693 out_attr[i].set_int_value(newval);
10694 }
10695 break;
10696 case elfcpp::Tag_PCS_config:
10697 if (out_attr[i].int_value() == 0)
10698 out_attr[i].set_int_value(in_attr[i].int_value());
10699 else if (in_attr[i].int_value() != 0
10700 && out_attr[i].int_value() != 0
10701 && parameters->options().warn_mismatch())
10702 {
10703 // It's sometimes ok to mix different configs, so this is only
10704 // a warning.
10705 gold_warning(_("%s: conflicting platform configuration"), name);
10706 }
10707 break;
10708 case elfcpp::Tag_ABI_PCS_R9_use:
10709 if (in_attr[i].int_value() != out_attr[i].int_value()
10710 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10711 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10712 && parameters->options().warn_mismatch())
10713 {
10714 gold_error(_("%s: conflicting use of R9"), name);
10715 }
10716 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10717 out_attr[i].set_int_value(in_attr[i].int_value());
10718 break;
10719 case elfcpp::Tag_ABI_PCS_RW_data:
10720 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10721 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10722 != elfcpp::AEABI_R9_SB)
10723 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10724 != elfcpp::AEABI_R9_unused)
10725 && parameters->options().warn_mismatch())
10726 {
10727 gold_error(_("%s: SB relative addressing conflicts with use "
10728 "of R9"),
10729 name);
10730 }
10731 // Use the smallest value specified.
10732 if (in_attr[i].int_value() < out_attr[i].int_value())
10733 out_attr[i].set_int_value(in_attr[i].int_value());
10734 break;
10735 case elfcpp::Tag_ABI_PCS_wchar_t:
10736 if (out_attr[i].int_value()
10737 && in_attr[i].int_value()
10738 && out_attr[i].int_value() != in_attr[i].int_value()
10739 && parameters->options().warn_mismatch()
10740 && parameters->options().wchar_size_warning())
10741 {
10742 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10743 "use %u-byte wchar_t; use of wchar_t values "
10744 "across objects may fail"),
10745 name, in_attr[i].int_value(),
10746 out_attr[i].int_value());
10747 }
10748 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10749 out_attr[i].set_int_value(in_attr[i].int_value());
10750 break;
10751 case elfcpp::Tag_ABI_enum_size:
10752 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10753 {
10754 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10755 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10756 {
10757 // The existing object is compatible with anything.
10758 // Use whatever requirements the new object has.
10759 out_attr[i].set_int_value(in_attr[i].int_value());
10760 }
10761 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10762 && out_attr[i].int_value() != in_attr[i].int_value()
10763 && parameters->options().warn_mismatch()
10764 && parameters->options().enum_size_warning())
10765 {
10766 unsigned int in_value = in_attr[i].int_value();
10767 unsigned int out_value = out_attr[i].int_value();
10768 gold_warning(_("%s uses %s enums yet the output is to use "
10769 "%s enums; use of enum values across objects "
10770 "may fail"),
10771 name,
10772 this->aeabi_enum_name(in_value).c_str(),
10773 this->aeabi_enum_name(out_value).c_str());
10774 }
10775 }
10776 break;
10777 case elfcpp::Tag_ABI_VFP_args:
10778 // Already done.
10779 break;
10780 case elfcpp::Tag_ABI_WMMX_args:
10781 if (in_attr[i].int_value() != out_attr[i].int_value()
10782 && parameters->options().warn_mismatch())
10783 {
10784 gold_error(_("%s uses iWMMXt register arguments, output does "
10785 "not"),
10786 name);
10787 }
10788 break;
10789 case Object_attribute::Tag_compatibility:
10790 // Merged in target-independent code.
10791 break;
10792 case elfcpp::Tag_ABI_HardFP_use:
10793 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10794 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10795 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10796 out_attr[i].set_int_value(3);
10797 else if (in_attr[i].int_value() > out_attr[i].int_value())
10798 out_attr[i].set_int_value(in_attr[i].int_value());
10799 break;
10800 case elfcpp::Tag_ABI_FP_16bit_format:
10801 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10802 {
10803 if (in_attr[i].int_value() != out_attr[i].int_value()
10804 && parameters->options().warn_mismatch())
10805 gold_error(_("fp16 format mismatch between %s and output"),
10806 name);
10807 }
10808 if (in_attr[i].int_value() != 0)
10809 out_attr[i].set_int_value(in_attr[i].int_value());
10810 break;
10811
10812 case elfcpp::Tag_DIV_use:
10813 {
10814 // A value of zero on input means that the divide
10815 // instruction may be used if available in the base
10816 // architecture as specified via Tag_CPU_arch and
10817 // Tag_CPU_arch_profile. A value of 1 means that the user
10818 // did not want divide instructions. A value of 2
10819 // explicitly means that divide instructions were allowed
10820 // in ARM and Thumb state.
10821 int arch = this->
10822 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
10823 int_value();
10824 int profile = this->
10825 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
10826 int_value();
10827 if (in_attr[i].int_value() == out_attr[i].int_value())
10828 {
10829 // Do nothing.
10830 }
10831 else if (attributes_forbid_div(&in_attr[i])
10832 && !attributes_accept_div(arch, profile, &out_attr[i]))
10833 out_attr[i].set_int_value(1);
10834 else if (attributes_forbid_div(&out_attr[i])
10835 && attributes_accept_div(arch, profile, &in_attr[i]))
10836 out_attr[i].set_int_value(in_attr[i].int_value());
10837 else if (in_attr[i].int_value() == 2)
10838 out_attr[i].set_int_value(in_attr[i].int_value());
10839 }
10840 break;
10841
10842 case elfcpp::Tag_MPextension_use_legacy:
10843 // We don't output objects with Tag_MPextension_use_legacy - we
10844 // move the value to Tag_MPextension_use.
10845 if (in_attr[i].int_value() != 0
10846 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10847 {
10848 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10849 != in_attr[i].int_value())
10850 {
10851 gold_error(_("%s has has both the current and legacy "
10852 "Tag_MPextension_use attributes"),
10853 name);
10854 }
10855 }
10856
10857 if (in_attr[i].int_value()
10858 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10859 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10860
10861 break;
10862
10863 case elfcpp::Tag_nodefaults:
10864 // This tag is set if it exists, but the value is unused (and is
10865 // typically zero). We don't actually need to do anything here -
10866 // the merge happens automatically when the type flags are merged
10867 // below.
10868 break;
10869 case elfcpp::Tag_also_compatible_with:
10870 // Already done in Tag_CPU_arch.
10871 break;
10872 case elfcpp::Tag_conformance:
10873 // Keep the attribute if it matches. Throw it away otherwise.
10874 // No attribute means no claim to conform.
10875 if (in_attr[i].string_value() != out_attr[i].string_value())
10876 out_attr[i].set_string_value("");
10877 break;
10878
10879 default:
10880 {
10881 const char* err_object = NULL;
10882
10883 // The "known_obj_attributes" table does contain some undefined
10884 // attributes. Ensure that there are unused.
10885 if (out_attr[i].int_value() != 0
10886 || out_attr[i].string_value() != "")
10887 err_object = "output";
10888 else if (in_attr[i].int_value() != 0
10889 || in_attr[i].string_value() != "")
10890 err_object = name;
10891
10892 if (err_object != NULL
10893 && parameters->options().warn_mismatch())
10894 {
10895 // Attribute numbers >=64 (mod 128) can be safely ignored.
10896 if ((i & 127) < 64)
10897 gold_error(_("%s: unknown mandatory EABI object attribute "
10898 "%d"),
10899 err_object, i);
10900 else
10901 gold_warning(_("%s: unknown EABI object attribute %d"),
10902 err_object, i);
10903 }
10904
10905 // Only pass on attributes that match in both inputs.
10906 if (!in_attr[i].matches(out_attr[i]))
10907 {
10908 out_attr[i].set_int_value(0);
10909 out_attr[i].set_string_value("");
10910 }
10911 }
10912 }
10913
10914 // If out_attr was copied from in_attr then it won't have a type yet.
10915 if (in_attr[i].type() && !out_attr[i].type())
10916 out_attr[i].set_type(in_attr[i].type());
10917 }
10918
10919 // Merge Tag_compatibility attributes and any common GNU ones.
10920 this->attributes_section_data_->merge(name, pasd);
10921
10922 // Check for any attributes not known on ARM.
10923 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10924 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10925 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10926 Other_attributes* out_other_attributes =
10927 this->attributes_section_data_->other_attributes(vendor);
10928 Other_attributes::iterator out_iter = out_other_attributes->begin();
10929
10930 while (in_iter != in_other_attributes->end()
10931 || out_iter != out_other_attributes->end())
10932 {
10933 const char* err_object = NULL;
10934 int err_tag = 0;
10935
10936 // The tags for each list are in numerical order.
10937 // If the tags are equal, then merge.
10938 if (out_iter != out_other_attributes->end()
10939 && (in_iter == in_other_attributes->end()
10940 || in_iter->first > out_iter->first))
10941 {
10942 // This attribute only exists in output. We can't merge, and we
10943 // don't know what the tag means, so delete it.
10944 err_object = "output";
10945 err_tag = out_iter->first;
10946 int saved_tag = out_iter->first;
10947 delete out_iter->second;
10948 out_other_attributes->erase(out_iter);
10949 out_iter = out_other_attributes->upper_bound(saved_tag);
10950 }
10951 else if (in_iter != in_other_attributes->end()
10952 && (out_iter != out_other_attributes->end()
10953 || in_iter->first < out_iter->first))
10954 {
10955 // This attribute only exists in input. We can't merge, and we
10956 // don't know what the tag means, so ignore it.
10957 err_object = name;
10958 err_tag = in_iter->first;
10959 ++in_iter;
10960 }
10961 else // The tags are equal.
10962 {
10963 // As present, all attributes in the list are unknown, and
10964 // therefore can't be merged meaningfully.
10965 err_object = "output";
10966 err_tag = out_iter->first;
10967
10968 // Only pass on attributes that match in both inputs.
10969 if (!in_iter->second->matches(*(out_iter->second)))
10970 {
10971 // No match. Delete the attribute.
10972 int saved_tag = out_iter->first;
10973 delete out_iter->second;
10974 out_other_attributes->erase(out_iter);
10975 out_iter = out_other_attributes->upper_bound(saved_tag);
10976 }
10977 else
10978 {
10979 // Matched. Keep the attribute and move to the next.
10980 ++out_iter;
10981 ++in_iter;
10982 }
10983 }
10984
10985 if (err_object && parameters->options().warn_mismatch())
10986 {
10987 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10988 if ((err_tag & 127) < 64)
10989 {
10990 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10991 err_object, err_tag);
10992 }
10993 else
10994 {
10995 gold_warning(_("%s: unknown EABI object attribute %d"),
10996 err_object, err_tag);
10997 }
10998 }
10999 }
11000 }
11001
11002 // Stub-generation methods for Target_arm.
11003
11004 // Make a new Arm_input_section object.
11005
11006 template<bool big_endian>
11007 Arm_input_section<big_endian>*
11008 Target_arm<big_endian>::new_arm_input_section(
11009 Relobj* relobj,
11010 unsigned int shndx)
11011 {
11012 Section_id sid(relobj, shndx);
11013
11014 Arm_input_section<big_endian>* arm_input_section =
11015 new Arm_input_section<big_endian>(relobj, shndx);
11016 arm_input_section->init();
11017
11018 // Register new Arm_input_section in map for look-up.
11019 std::pair<typename Arm_input_section_map::iterator, bool> ins =
11020 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11021
11022 // Make sure that it we have not created another Arm_input_section
11023 // for this input section already.
11024 gold_assert(ins.second);
11025
11026 return arm_input_section;
11027 }
11028
11029 // Find the Arm_input_section object corresponding to the SHNDX-th input
11030 // section of RELOBJ.
11031
11032 template<bool big_endian>
11033 Arm_input_section<big_endian>*
11034 Target_arm<big_endian>::find_arm_input_section(
11035 Relobj* relobj,
11036 unsigned int shndx) const
11037 {
11038 Section_id sid(relobj, shndx);
11039 typename Arm_input_section_map::const_iterator p =
11040 this->arm_input_section_map_.find(sid);
11041 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11042 }
11043
11044 // Make a new stub table.
11045
11046 template<bool big_endian>
11047 Stub_table<big_endian>*
11048 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11049 {
11050 Stub_table<big_endian>* stub_table =
11051 new Stub_table<big_endian>(owner);
11052 this->stub_tables_.push_back(stub_table);
11053
11054 stub_table->set_address(owner->address() + owner->data_size());
11055 stub_table->set_file_offset(owner->offset() + owner->data_size());
11056 stub_table->finalize_data_size();
11057
11058 return stub_table;
11059 }
11060
11061 // Scan a relocation for stub generation.
11062
11063 template<bool big_endian>
11064 void
11065 Target_arm<big_endian>::scan_reloc_for_stub(
11066 const Relocate_info<32, big_endian>* relinfo,
11067 unsigned int r_type,
11068 const Sized_symbol<32>* gsym,
11069 unsigned int r_sym,
11070 const Symbol_value<32>* psymval,
11071 elfcpp::Elf_types<32>::Elf_Swxword addend,
11072 Arm_address address)
11073 {
11074 const Arm_relobj<big_endian>* arm_relobj =
11075 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11076
11077 bool target_is_thumb;
11078 Symbol_value<32> symval;
11079 if (gsym != NULL)
11080 {
11081 // This is a global symbol. Determine if we use PLT and if the
11082 // final target is THUMB.
11083 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11084 {
11085 // This uses a PLT, change the symbol value.
11086 symval.set_output_value(this->plt_section()->address()
11087 + gsym->plt_offset());
11088 psymval = &symval;
11089 target_is_thumb = false;
11090 }
11091 else if (gsym->is_undefined())
11092 // There is no need to generate a stub symbol is undefined.
11093 return;
11094 else
11095 {
11096 target_is_thumb =
11097 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11098 || (gsym->type() == elfcpp::STT_FUNC
11099 && !gsym->is_undefined()
11100 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11101 }
11102 }
11103 else
11104 {
11105 // This is a local symbol. Determine if the final target is THUMB.
11106 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11107 }
11108
11109 // Strip LSB if this points to a THUMB target.
11110 const Arm_reloc_property* reloc_property =
11111 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11112 gold_assert(reloc_property != NULL);
11113 if (target_is_thumb
11114 && reloc_property->uses_thumb_bit()
11115 && ((psymval->value(arm_relobj, 0) & 1) != 0))
11116 {
11117 Arm_address stripped_value =
11118 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11119 symval.set_output_value(stripped_value);
11120 psymval = &symval;
11121 }
11122
11123 // Get the symbol value.
11124 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11125
11126 // Owing to pipelining, the PC relative branches below actually skip
11127 // two instructions when the branch offset is 0.
11128 Arm_address destination;
11129 switch (r_type)
11130 {
11131 case elfcpp::R_ARM_CALL:
11132 case elfcpp::R_ARM_JUMP24:
11133 case elfcpp::R_ARM_PLT32:
11134 // ARM branches.
11135 destination = value + addend + 8;
11136 break;
11137 case elfcpp::R_ARM_THM_CALL:
11138 case elfcpp::R_ARM_THM_XPC22:
11139 case elfcpp::R_ARM_THM_JUMP24:
11140 case elfcpp::R_ARM_THM_JUMP19:
11141 // THUMB branches.
11142 destination = value + addend + 4;
11143 break;
11144 default:
11145 gold_unreachable();
11146 }
11147
11148 Reloc_stub* stub = NULL;
11149 Stub_type stub_type =
11150 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11151 target_is_thumb);
11152 if (stub_type != arm_stub_none)
11153 {
11154 // Try looking up an existing stub from a stub table.
11155 Stub_table<big_endian>* stub_table =
11156 arm_relobj->stub_table(relinfo->data_shndx);
11157 gold_assert(stub_table != NULL);
11158
11159 // Locate stub by destination.
11160 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11161
11162 // Create a stub if there is not one already
11163 stub = stub_table->find_reloc_stub(stub_key);
11164 if (stub == NULL)
11165 {
11166 // create a new stub and add it to stub table.
11167 stub = this->stub_factory().make_reloc_stub(stub_type);
11168 stub_table->add_reloc_stub(stub, stub_key);
11169 }
11170
11171 // Record the destination address.
11172 stub->set_destination_address(destination
11173 | (target_is_thumb ? 1 : 0));
11174 }
11175
11176 // For Cortex-A8, we need to record a relocation at 4K page boundary.
11177 if (this->fix_cortex_a8_
11178 && (r_type == elfcpp::R_ARM_THM_JUMP24
11179 || r_type == elfcpp::R_ARM_THM_JUMP19
11180 || r_type == elfcpp::R_ARM_THM_CALL
11181 || r_type == elfcpp::R_ARM_THM_XPC22)
11182 && (address & 0xfffU) == 0xffeU)
11183 {
11184 // Found a candidate. Note we haven't checked the destination is
11185 // within 4K here: if we do so (and don't create a record) we can't
11186 // tell that a branch should have been relocated when scanning later.
11187 this->cortex_a8_relocs_info_[address] =
11188 new Cortex_a8_reloc(stub, r_type,
11189 destination | (target_is_thumb ? 1 : 0));
11190 }
11191 }
11192
11193 // This function scans a relocation sections for stub generation.
11194 // The template parameter Relocate must be a class type which provides
11195 // a single function, relocate(), which implements the machine
11196 // specific part of a relocation.
11197
11198 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11199 // SHT_REL or SHT_RELA.
11200
11201 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11202 // of relocs. OUTPUT_SECTION is the output section.
11203 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11204 // mapped to output offsets.
11205
11206 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11207 // VIEW_SIZE is the size. These refer to the input section, unless
11208 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11209 // the output section.
11210
11211 template<bool big_endian>
11212 template<int sh_type>
11213 void inline
11214 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11215 const Relocate_info<32, big_endian>* relinfo,
11216 const unsigned char* prelocs,
11217 size_t reloc_count,
11218 Output_section* output_section,
11219 bool needs_special_offset_handling,
11220 const unsigned char* view,
11221 elfcpp::Elf_types<32>::Elf_Addr view_address,
11222 section_size_type)
11223 {
11224 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11225 const int reloc_size =
11226 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11227
11228 Arm_relobj<big_endian>* arm_object =
11229 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11230 unsigned int local_count = arm_object->local_symbol_count();
11231
11232 gold::Default_comdat_behavior default_comdat_behavior;
11233 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11234
11235 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11236 {
11237 Reltype reloc(prelocs);
11238
11239 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11240 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11241 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11242
11243 r_type = this->get_real_reloc_type(r_type);
11244
11245 // Only a few relocation types need stubs.
11246 if ((r_type != elfcpp::R_ARM_CALL)
11247 && (r_type != elfcpp::R_ARM_JUMP24)
11248 && (r_type != elfcpp::R_ARM_PLT32)
11249 && (r_type != elfcpp::R_ARM_THM_CALL)
11250 && (r_type != elfcpp::R_ARM_THM_XPC22)
11251 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11252 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11253 && (r_type != elfcpp::R_ARM_V4BX))
11254 continue;
11255
11256 section_offset_type offset =
11257 convert_to_section_size_type(reloc.get_r_offset());
11258
11259 if (needs_special_offset_handling)
11260 {
11261 offset = output_section->output_offset(relinfo->object,
11262 relinfo->data_shndx,
11263 offset);
11264 if (offset == -1)
11265 continue;
11266 }
11267
11268 // Create a v4bx stub if --fix-v4bx-interworking is used.
11269 if (r_type == elfcpp::R_ARM_V4BX)
11270 {
11271 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11272 {
11273 // Get the BX instruction.
11274 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11275 const Valtype* wv =
11276 reinterpret_cast<const Valtype*>(view + offset);
11277 elfcpp::Elf_types<32>::Elf_Swxword insn =
11278 elfcpp::Swap<32, big_endian>::readval(wv);
11279 const uint32_t reg = (insn & 0xf);
11280
11281 if (reg < 0xf)
11282 {
11283 // Try looking up an existing stub from a stub table.
11284 Stub_table<big_endian>* stub_table =
11285 arm_object->stub_table(relinfo->data_shndx);
11286 gold_assert(stub_table != NULL);
11287
11288 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11289 {
11290 // create a new stub and add it to stub table.
11291 Arm_v4bx_stub* stub =
11292 this->stub_factory().make_arm_v4bx_stub(reg);
11293 gold_assert(stub != NULL);
11294 stub_table->add_arm_v4bx_stub(stub);
11295 }
11296 }
11297 }
11298 continue;
11299 }
11300
11301 // Get the addend.
11302 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11303 elfcpp::Elf_types<32>::Elf_Swxword addend =
11304 stub_addend_reader(r_type, view + offset, reloc);
11305
11306 const Sized_symbol<32>* sym;
11307
11308 Symbol_value<32> symval;
11309 const Symbol_value<32> *psymval;
11310 bool is_defined_in_discarded_section;
11311 unsigned int shndx;
11312 if (r_sym < local_count)
11313 {
11314 sym = NULL;
11315 psymval = arm_object->local_symbol(r_sym);
11316
11317 // If the local symbol belongs to a section we are discarding,
11318 // and that section is a debug section, try to find the
11319 // corresponding kept section and map this symbol to its
11320 // counterpart in the kept section. The symbol must not
11321 // correspond to a section we are folding.
11322 bool is_ordinary;
11323 shndx = psymval->input_shndx(&is_ordinary);
11324 is_defined_in_discarded_section =
11325 (is_ordinary
11326 && shndx != elfcpp::SHN_UNDEF
11327 && !arm_object->is_section_included(shndx)
11328 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11329
11330 // We need to compute the would-be final value of this local
11331 // symbol.
11332 if (!is_defined_in_discarded_section)
11333 {
11334 typedef Sized_relobj_file<32, big_endian> ObjType;
11335 typename ObjType::Compute_final_local_value_status status =
11336 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11337 relinfo->symtab);
11338 if (status == ObjType::CFLV_OK)
11339 {
11340 // Currently we cannot handle a branch to a target in
11341 // a merged section. If this is the case, issue an error
11342 // and also free the merge symbol value.
11343 if (!symval.has_output_value())
11344 {
11345 const std::string& section_name =
11346 arm_object->section_name(shndx);
11347 arm_object->error(_("cannot handle branch to local %u "
11348 "in a merged section %s"),
11349 r_sym, section_name.c_str());
11350 }
11351 psymval = &symval;
11352 }
11353 else
11354 {
11355 // We cannot determine the final value.
11356 continue;
11357 }
11358 }
11359 }
11360 else
11361 {
11362 const Symbol* gsym;
11363 gsym = arm_object->global_symbol(r_sym);
11364 gold_assert(gsym != NULL);
11365 if (gsym->is_forwarder())
11366 gsym = relinfo->symtab->resolve_forwards(gsym);
11367
11368 sym = static_cast<const Sized_symbol<32>*>(gsym);
11369 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11370 symval.set_output_symtab_index(sym->symtab_index());
11371 else
11372 symval.set_no_output_symtab_entry();
11373
11374 // We need to compute the would-be final value of this global
11375 // symbol.
11376 const Symbol_table* symtab = relinfo->symtab;
11377 const Sized_symbol<32>* sized_symbol =
11378 symtab->get_sized_symbol<32>(gsym);
11379 Symbol_table::Compute_final_value_status status;
11380 Arm_address value =
11381 symtab->compute_final_value<32>(sized_symbol, &status);
11382
11383 // Skip this if the symbol has not output section.
11384 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11385 continue;
11386 symval.set_output_value(value);
11387
11388 if (gsym->type() == elfcpp::STT_TLS)
11389 symval.set_is_tls_symbol();
11390 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11391 symval.set_is_ifunc_symbol();
11392 psymval = &symval;
11393
11394 is_defined_in_discarded_section =
11395 (gsym->is_defined_in_discarded_section()
11396 && gsym->is_undefined());
11397 shndx = 0;
11398 }
11399
11400 Symbol_value<32> symval2;
11401 if (is_defined_in_discarded_section)
11402 {
11403 if (comdat_behavior == CB_UNDETERMINED)
11404 {
11405 std::string name = arm_object->section_name(relinfo->data_shndx);
11406 comdat_behavior = default_comdat_behavior.get(name.c_str());
11407 }
11408 if (comdat_behavior == CB_PRETEND)
11409 {
11410 // FIXME: This case does not work for global symbols.
11411 // We have no place to store the original section index.
11412 // Fortunately this does not matter for comdat sections,
11413 // only for sections explicitly discarded by a linker
11414 // script.
11415 bool found;
11416 typename elfcpp::Elf_types<32>::Elf_Addr value =
11417 arm_object->map_to_kept_section(shndx, &found);
11418 if (found)
11419 symval2.set_output_value(value + psymval->input_value());
11420 else
11421 symval2.set_output_value(0);
11422 }
11423 else
11424 {
11425 if (comdat_behavior == CB_WARNING)
11426 gold_warning_at_location(relinfo, i, offset,
11427 _("relocation refers to discarded "
11428 "section"));
11429 symval2.set_output_value(0);
11430 }
11431 symval2.set_no_output_symtab_entry();
11432 psymval = &symval2;
11433 }
11434
11435 // If symbol is a section symbol, we don't know the actual type of
11436 // destination. Give up.
11437 if (psymval->is_section_symbol())
11438 continue;
11439
11440 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11441 addend, view_address + offset);
11442 }
11443 }
11444
11445 // Scan an input section for stub generation.
11446
11447 template<bool big_endian>
11448 void
11449 Target_arm<big_endian>::scan_section_for_stubs(
11450 const Relocate_info<32, big_endian>* relinfo,
11451 unsigned int sh_type,
11452 const unsigned char* prelocs,
11453 size_t reloc_count,
11454 Output_section* output_section,
11455 bool needs_special_offset_handling,
11456 const unsigned char* view,
11457 Arm_address view_address,
11458 section_size_type view_size)
11459 {
11460 if (sh_type == elfcpp::SHT_REL)
11461 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11462 relinfo,
11463 prelocs,
11464 reloc_count,
11465 output_section,
11466 needs_special_offset_handling,
11467 view,
11468 view_address,
11469 view_size);
11470 else if (sh_type == elfcpp::SHT_RELA)
11471 // We do not support RELA type relocations yet. This is provided for
11472 // completeness.
11473 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11474 relinfo,
11475 prelocs,
11476 reloc_count,
11477 output_section,
11478 needs_special_offset_handling,
11479 view,
11480 view_address,
11481 view_size);
11482 else
11483 gold_unreachable();
11484 }
11485
11486 // Group input sections for stub generation.
11487 //
11488 // We group input sections in an output section so that the total size,
11489 // including any padding space due to alignment is smaller than GROUP_SIZE
11490 // unless the only input section in group is bigger than GROUP_SIZE already.
11491 // Then an ARM stub table is created to follow the last input section
11492 // in group. For each group an ARM stub table is created an is placed
11493 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
11494 // extend the group after the stub table.
11495
11496 template<bool big_endian>
11497 void
11498 Target_arm<big_endian>::group_sections(
11499 Layout* layout,
11500 section_size_type group_size,
11501 bool stubs_always_after_branch,
11502 const Task* task)
11503 {
11504 // Group input sections and insert stub table
11505 Layout::Section_list section_list;
11506 layout->get_executable_sections(&section_list);
11507 for (Layout::Section_list::const_iterator p = section_list.begin();
11508 p != section_list.end();
11509 ++p)
11510 {
11511 Arm_output_section<big_endian>* output_section =
11512 Arm_output_section<big_endian>::as_arm_output_section(*p);
11513 output_section->group_sections(group_size, stubs_always_after_branch,
11514 this, task);
11515 }
11516 }
11517
11518 // Relaxation hook. This is where we do stub generation.
11519
11520 template<bool big_endian>
11521 bool
11522 Target_arm<big_endian>::do_relax(
11523 int pass,
11524 const Input_objects* input_objects,
11525 Symbol_table* symtab,
11526 Layout* layout,
11527 const Task* task)
11528 {
11529 // No need to generate stubs if this is a relocatable link.
11530 gold_assert(!parameters->options().relocatable());
11531
11532 // If this is the first pass, we need to group input sections into
11533 // stub groups.
11534 bool done_exidx_fixup = false;
11535 typedef typename Stub_table_list::iterator Stub_table_iterator;
11536 if (pass == 1)
11537 {
11538 // Determine the stub group size. The group size is the absolute
11539 // value of the parameter --stub-group-size. If --stub-group-size
11540 // is passed a negative value, we restrict stubs to be always after
11541 // the stubbed branches.
11542 int32_t stub_group_size_param =
11543 parameters->options().stub_group_size();
11544 bool stubs_always_after_branch = stub_group_size_param < 0;
11545 section_size_type stub_group_size = abs(stub_group_size_param);
11546
11547 if (stub_group_size == 1)
11548 {
11549 // Default value.
11550 // Thumb branch range is +-4MB has to be used as the default
11551 // maximum size (a given section can contain both ARM and Thumb
11552 // code, so the worst case has to be taken into account). If we are
11553 // fixing cortex-a8 errata, the branch range has to be even smaller,
11554 // since wide conditional branch has a range of +-1MB only.
11555 //
11556 // This value is 48K less than that, which allows for 4096
11557 // 12-byte stubs. If we exceed that, then we will fail to link.
11558 // The user will have to relink with an explicit group size
11559 // option.
11560 stub_group_size = 4145152;
11561 }
11562
11563 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11564 // page as the first half of a 32-bit branch straddling two 4K pages.
11565 // This is a crude way of enforcing that. In addition, long conditional
11566 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11567 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11568 // cortex-A8 stubs from long conditional branches.
11569 if (this->fix_cortex_a8_)
11570 {
11571 stubs_always_after_branch = true;
11572 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11573 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11574 }
11575
11576 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11577
11578 // Also fix .ARM.exidx section coverage.
11579 Arm_output_section<big_endian>* exidx_output_section = NULL;
11580 for (Layout::Section_list::const_iterator p =
11581 layout->section_list().begin();
11582 p != layout->section_list().end();
11583 ++p)
11584 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11585 {
11586 if (exidx_output_section == NULL)
11587 exidx_output_section =
11588 Arm_output_section<big_endian>::as_arm_output_section(*p);
11589 else
11590 // We cannot handle this now.
11591 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11592 "non-relocatable link"),
11593 exidx_output_section->name(),
11594 (*p)->name());
11595 }
11596
11597 if (exidx_output_section != NULL)
11598 {
11599 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11600 symtab, task);
11601 done_exidx_fixup = true;
11602 }
11603 }
11604 else
11605 {
11606 // If this is not the first pass, addresses and file offsets have
11607 // been reset at this point, set them here.
11608 for (Stub_table_iterator sp = this->stub_tables_.begin();
11609 sp != this->stub_tables_.end();
11610 ++sp)
11611 {
11612 Arm_input_section<big_endian>* owner = (*sp)->owner();
11613 off_t off = align_address(owner->original_size(),
11614 (*sp)->addralign());
11615 (*sp)->set_address_and_file_offset(owner->address() + off,
11616 owner->offset() + off);
11617 }
11618 }
11619
11620 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11621 // beginning of each relaxation pass, just blow away all the stubs.
11622 // Alternatively, we could selectively remove only the stubs and reloc
11623 // information for code sections that have moved since the last pass.
11624 // That would require more book-keeping.
11625 if (this->fix_cortex_a8_)
11626 {
11627 // Clear all Cortex-A8 reloc information.
11628 for (typename Cortex_a8_relocs_info::const_iterator p =
11629 this->cortex_a8_relocs_info_.begin();
11630 p != this->cortex_a8_relocs_info_.end();
11631 ++p)
11632 delete p->second;
11633 this->cortex_a8_relocs_info_.clear();
11634
11635 // Remove all Cortex-A8 stubs.
11636 for (Stub_table_iterator sp = this->stub_tables_.begin();
11637 sp != this->stub_tables_.end();
11638 ++sp)
11639 (*sp)->remove_all_cortex_a8_stubs();
11640 }
11641
11642 // Scan relocs for relocation stubs
11643 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11644 op != input_objects->relobj_end();
11645 ++op)
11646 {
11647 Arm_relobj<big_endian>* arm_relobj =
11648 Arm_relobj<big_endian>::as_arm_relobj(*op);
11649 // Lock the object so we can read from it. This is only called
11650 // single-threaded from Layout::finalize, so it is OK to lock.
11651 Task_lock_obj<Object> tl(task, arm_relobj);
11652 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11653 }
11654
11655 // Check all stub tables to see if any of them have their data sizes
11656 // or addresses alignments changed. These are the only things that
11657 // matter.
11658 bool any_stub_table_changed = false;
11659 Unordered_set<const Output_section*> sections_needing_adjustment;
11660 for (Stub_table_iterator sp = this->stub_tables_.begin();
11661 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11662 ++sp)
11663 {
11664 if ((*sp)->update_data_size_and_addralign())
11665 {
11666 // Update data size of stub table owner.
11667 Arm_input_section<big_endian>* owner = (*sp)->owner();
11668 uint64_t address = owner->address();
11669 off_t offset = owner->offset();
11670 owner->reset_address_and_file_offset();
11671 owner->set_address_and_file_offset(address, offset);
11672
11673 sections_needing_adjustment.insert(owner->output_section());
11674 any_stub_table_changed = true;
11675 }
11676 }
11677
11678 // Output_section_data::output_section() returns a const pointer but we
11679 // need to update output sections, so we record all output sections needing
11680 // update above and scan the sections here to find out what sections need
11681 // to be updated.
11682 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11683 p != layout->section_list().end();
11684 ++p)
11685 {
11686 if (sections_needing_adjustment.find(*p)
11687 != sections_needing_adjustment.end())
11688 (*p)->set_section_offsets_need_adjustment();
11689 }
11690
11691 // Stop relaxation if no EXIDX fix-up and no stub table change.
11692 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11693
11694 // Finalize the stubs in the last relaxation pass.
11695 if (!continue_relaxation)
11696 {
11697 for (Stub_table_iterator sp = this->stub_tables_.begin();
11698 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11699 ++sp)
11700 (*sp)->finalize_stubs();
11701
11702 // Update output local symbol counts of objects if necessary.
11703 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11704 op != input_objects->relobj_end();
11705 ++op)
11706 {
11707 Arm_relobj<big_endian>* arm_relobj =
11708 Arm_relobj<big_endian>::as_arm_relobj(*op);
11709
11710 // Update output local symbol counts. We need to discard local
11711 // symbols defined in parts of input sections that are discarded by
11712 // relaxation.
11713 if (arm_relobj->output_local_symbol_count_needs_update())
11714 {
11715 // We need to lock the object's file to update it.
11716 Task_lock_obj<Object> tl(task, arm_relobj);
11717 arm_relobj->update_output_local_symbol_count();
11718 }
11719 }
11720 }
11721
11722 return continue_relaxation;
11723 }
11724
11725 // Relocate a stub.
11726
11727 template<bool big_endian>
11728 void
11729 Target_arm<big_endian>::relocate_stub(
11730 Stub* stub,
11731 const Relocate_info<32, big_endian>* relinfo,
11732 Output_section* output_section,
11733 unsigned char* view,
11734 Arm_address address,
11735 section_size_type view_size)
11736 {
11737 Relocate relocate;
11738 const Stub_template* stub_template = stub->stub_template();
11739 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11740 {
11741 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11742 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11743
11744 unsigned int r_type = insn->r_type();
11745 section_size_type reloc_offset = stub_template->reloc_offset(i);
11746 section_size_type reloc_size = insn->size();
11747 gold_assert(reloc_offset + reloc_size <= view_size);
11748
11749 // This is the address of the stub destination.
11750 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11751 Symbol_value<32> symval;
11752 symval.set_output_value(target);
11753
11754 // Synthesize a fake reloc just in case. We don't have a symbol so
11755 // we use 0.
11756 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11757 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11758 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11759 reloc_write.put_r_offset(reloc_offset);
11760 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11761 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11762
11763 relocate.relocate(relinfo, this, output_section,
11764 this->fake_relnum_for_stubs, rel, r_type,
11765 NULL, &symval, view + reloc_offset,
11766 address + reloc_offset, reloc_size);
11767 }
11768 }
11769
11770 // Determine whether an object attribute tag takes an integer, a
11771 // string or both.
11772
11773 template<bool big_endian>
11774 int
11775 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11776 {
11777 if (tag == Object_attribute::Tag_compatibility)
11778 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11779 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11780 else if (tag == elfcpp::Tag_nodefaults)
11781 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11782 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11783 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11784 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11785 else if (tag < 32)
11786 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11787 else
11788 return ((tag & 1) != 0
11789 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11790 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11791 }
11792
11793 // Reorder attributes.
11794 //
11795 // The ABI defines that Tag_conformance should be emitted first, and that
11796 // Tag_nodefaults should be second (if either is defined). This sets those
11797 // two positions, and bumps up the position of all the remaining tags to
11798 // compensate.
11799
11800 template<bool big_endian>
11801 int
11802 Target_arm<big_endian>::do_attributes_order(int num) const
11803 {
11804 // Reorder the known object attributes in output. We want to move
11805 // Tag_conformance to position 4 and Tag_conformance to position 5
11806 // and shift everything between 4 .. Tag_conformance - 1 to make room.
11807 if (num == 4)
11808 return elfcpp::Tag_conformance;
11809 if (num == 5)
11810 return elfcpp::Tag_nodefaults;
11811 if ((num - 2) < elfcpp::Tag_nodefaults)
11812 return num - 2;
11813 if ((num - 1) < elfcpp::Tag_conformance)
11814 return num - 1;
11815 return num;
11816 }
11817
11818 // Scan a span of THUMB code for Cortex-A8 erratum.
11819
11820 template<bool big_endian>
11821 void
11822 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11823 Arm_relobj<big_endian>* arm_relobj,
11824 unsigned int shndx,
11825 section_size_type span_start,
11826 section_size_type span_end,
11827 const unsigned char* view,
11828 Arm_address address)
11829 {
11830 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11831 //
11832 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11833 // The branch target is in the same 4KB region as the
11834 // first half of the branch.
11835 // The instruction before the branch is a 32-bit
11836 // length non-branch instruction.
11837 section_size_type i = span_start;
11838 bool last_was_32bit = false;
11839 bool last_was_branch = false;
11840 while (i < span_end)
11841 {
11842 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11843 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11844 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11845 bool is_blx = false, is_b = false;
11846 bool is_bl = false, is_bcc = false;
11847
11848 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11849 if (insn_32bit)
11850 {
11851 // Load the rest of the insn (in manual-friendly order).
11852 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11853
11854 // Encoding T4: B<c>.W.
11855 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11856 // Encoding T1: BL<c>.W.
11857 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11858 // Encoding T2: BLX<c>.W.
11859 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11860 // Encoding T3: B<c>.W (not permitted in IT block).
11861 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11862 && (insn & 0x07f00000U) != 0x03800000U);
11863 }
11864
11865 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11866
11867 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11868 // page boundary and it follows 32-bit non-branch instruction,
11869 // we need to work around.
11870 if (is_32bit_branch
11871 && ((address + i) & 0xfffU) == 0xffeU
11872 && last_was_32bit
11873 && !last_was_branch)
11874 {
11875 // Check to see if there is a relocation stub for this branch.
11876 bool force_target_arm = false;
11877 bool force_target_thumb = false;
11878 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11879 Cortex_a8_relocs_info::const_iterator p =
11880 this->cortex_a8_relocs_info_.find(address + i);
11881
11882 if (p != this->cortex_a8_relocs_info_.end())
11883 {
11884 cortex_a8_reloc = p->second;
11885 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11886
11887 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11888 && !target_is_thumb)
11889 force_target_arm = true;
11890 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11891 && target_is_thumb)
11892 force_target_thumb = true;
11893 }
11894
11895 off_t offset;
11896 Stub_type stub_type = arm_stub_none;
11897
11898 // Check if we have an offending branch instruction.
11899 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11900 uint16_t lower_insn = insn & 0xffffU;
11901 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11902
11903 if (cortex_a8_reloc != NULL
11904 && cortex_a8_reloc->reloc_stub() != NULL)
11905 // We've already made a stub for this instruction, e.g.
11906 // it's a long branch or a Thumb->ARM stub. Assume that
11907 // stub will suffice to work around the A8 erratum (see
11908 // setting of always_after_branch above).
11909 ;
11910 else if (is_bcc)
11911 {
11912 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11913 lower_insn);
11914 stub_type = arm_stub_a8_veneer_b_cond;
11915 }
11916 else if (is_b || is_bl || is_blx)
11917 {
11918 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11919 lower_insn);
11920 if (is_blx)
11921 offset &= ~3;
11922
11923 stub_type = (is_blx
11924 ? arm_stub_a8_veneer_blx
11925 : (is_bl
11926 ? arm_stub_a8_veneer_bl
11927 : arm_stub_a8_veneer_b));
11928 }
11929
11930 if (stub_type != arm_stub_none)
11931 {
11932 Arm_address pc_for_insn = address + i + 4;
11933
11934 // The original instruction is a BL, but the target is
11935 // an ARM instruction. If we were not making a stub,
11936 // the BL would have been converted to a BLX. Use the
11937 // BLX stub instead in that case.
11938 if (this->may_use_v5t_interworking() && force_target_arm
11939 && stub_type == arm_stub_a8_veneer_bl)
11940 {
11941 stub_type = arm_stub_a8_veneer_blx;
11942 is_blx = true;
11943 is_bl = false;
11944 }
11945 // Conversely, if the original instruction was
11946 // BLX but the target is Thumb mode, use the BL stub.
11947 else if (force_target_thumb
11948 && stub_type == arm_stub_a8_veneer_blx)
11949 {
11950 stub_type = arm_stub_a8_veneer_bl;
11951 is_blx = false;
11952 is_bl = true;
11953 }
11954
11955 if (is_blx)
11956 pc_for_insn &= ~3;
11957
11958 // If we found a relocation, use the proper destination,
11959 // not the offset in the (unrelocated) instruction.
11960 // Note this is always done if we switched the stub type above.
11961 if (cortex_a8_reloc != NULL)
11962 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11963
11964 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11965
11966 // Add a new stub if destination address in in the same page.
11967 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11968 {
11969 Cortex_a8_stub* stub =
11970 this->stub_factory_.make_cortex_a8_stub(stub_type,
11971 arm_relobj, shndx,
11972 address + i,
11973 target, insn);
11974 Stub_table<big_endian>* stub_table =
11975 arm_relobj->stub_table(shndx);
11976 gold_assert(stub_table != NULL);
11977 stub_table->add_cortex_a8_stub(address + i, stub);
11978 }
11979 }
11980 }
11981
11982 i += insn_32bit ? 4 : 2;
11983 last_was_32bit = insn_32bit;
11984 last_was_branch = is_32bit_branch;
11985 }
11986 }
11987
11988 // Apply the Cortex-A8 workaround.
11989
11990 template<bool big_endian>
11991 void
11992 Target_arm<big_endian>::apply_cortex_a8_workaround(
11993 const Cortex_a8_stub* stub,
11994 Arm_address stub_address,
11995 unsigned char* insn_view,
11996 Arm_address insn_address)
11997 {
11998 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11999 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
12000 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12001 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12002 off_t branch_offset = stub_address - (insn_address + 4);
12003
12004 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12005 switch (stub->stub_template()->type())
12006 {
12007 case arm_stub_a8_veneer_b_cond:
12008 // For a conditional branch, we re-write it to be an unconditional
12009 // branch to the stub. We use the THUMB-2 encoding here.
12010 upper_insn = 0xf000U;
12011 lower_insn = 0xb800U;
12012 // Fall through
12013 case arm_stub_a8_veneer_b:
12014 case arm_stub_a8_veneer_bl:
12015 case arm_stub_a8_veneer_blx:
12016 if ((lower_insn & 0x5000U) == 0x4000U)
12017 // For a BLX instruction, make sure that the relocation is
12018 // rounded up to a word boundary. This follows the semantics of
12019 // the instruction which specifies that bit 1 of the target
12020 // address will come from bit 1 of the base address.
12021 branch_offset = (branch_offset + 2) & ~3;
12022
12023 // Put BRANCH_OFFSET back into the insn.
12024 gold_assert(!Bits<25>::has_overflow32(branch_offset));
12025 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12026 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12027 break;
12028
12029 default:
12030 gold_unreachable();
12031 }
12032
12033 // Put the relocated value back in the object file:
12034 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12035 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12036 }
12037
12038 // Target selector for ARM. Note this is never instantiated directly.
12039 // It's only used in Target_selector_arm_nacl, below.
12040
12041 template<bool big_endian>
12042 class Target_selector_arm : public Target_selector
12043 {
12044 public:
12045 Target_selector_arm()
12046 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12047 (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12048 (big_endian ? "armelfb" : "armelf"))
12049 { }
12050
12051 Target*
12052 do_instantiate_target()
12053 { return new Target_arm<big_endian>(); }
12054 };
12055
12056 // Fix .ARM.exidx section coverage.
12057
12058 template<bool big_endian>
12059 void
12060 Target_arm<big_endian>::fix_exidx_coverage(
12061 Layout* layout,
12062 const Input_objects* input_objects,
12063 Arm_output_section<big_endian>* exidx_section,
12064 Symbol_table* symtab,
12065 const Task* task)
12066 {
12067 // We need to look at all the input sections in output in ascending
12068 // order of of output address. We do that by building a sorted list
12069 // of output sections by addresses. Then we looks at the output sections
12070 // in order. The input sections in an output section are already sorted
12071 // by addresses within the output section.
12072
12073 typedef std::set<Output_section*, output_section_address_less_than>
12074 Sorted_output_section_list;
12075 Sorted_output_section_list sorted_output_sections;
12076
12077 // Find out all the output sections of input sections pointed by
12078 // EXIDX input sections.
12079 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12080 p != input_objects->relobj_end();
12081 ++p)
12082 {
12083 Arm_relobj<big_endian>* arm_relobj =
12084 Arm_relobj<big_endian>::as_arm_relobj(*p);
12085 std::vector<unsigned int> shndx_list;
12086 arm_relobj->get_exidx_shndx_list(&shndx_list);
12087 for (size_t i = 0; i < shndx_list.size(); ++i)
12088 {
12089 const Arm_exidx_input_section* exidx_input_section =
12090 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12091 gold_assert(exidx_input_section != NULL);
12092 if (!exidx_input_section->has_errors())
12093 {
12094 unsigned int text_shndx = exidx_input_section->link();
12095 Output_section* os = arm_relobj->output_section(text_shndx);
12096 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12097 sorted_output_sections.insert(os);
12098 }
12099 }
12100 }
12101
12102 // Go over the output sections in ascending order of output addresses.
12103 typedef typename Arm_output_section<big_endian>::Text_section_list
12104 Text_section_list;
12105 Text_section_list sorted_text_sections;
12106 for (typename Sorted_output_section_list::iterator p =
12107 sorted_output_sections.begin();
12108 p != sorted_output_sections.end();
12109 ++p)
12110 {
12111 Arm_output_section<big_endian>* arm_output_section =
12112 Arm_output_section<big_endian>::as_arm_output_section(*p);
12113 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12114 }
12115
12116 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12117 merge_exidx_entries(), task);
12118 }
12119
12120 template<bool big_endian>
12121 void
12122 Target_arm<big_endian>::do_define_standard_symbols(
12123 Symbol_table* symtab,
12124 Layout* layout)
12125 {
12126 // Handle the .ARM.exidx section.
12127 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12128
12129 if (exidx_section != NULL)
12130 {
12131 // Create __exidx_start and __exidx_end symbols.
12132 symtab->define_in_output_data("__exidx_start",
12133 NULL, // version
12134 Symbol_table::PREDEFINED,
12135 exidx_section,
12136 0, // value
12137 0, // symsize
12138 elfcpp::STT_NOTYPE,
12139 elfcpp::STB_GLOBAL,
12140 elfcpp::STV_HIDDEN,
12141 0, // nonvis
12142 false, // offset_is_from_end
12143 true); // only_if_ref
12144
12145 symtab->define_in_output_data("__exidx_end",
12146 NULL, // version
12147 Symbol_table::PREDEFINED,
12148 exidx_section,
12149 0, // value
12150 0, // symsize
12151 elfcpp::STT_NOTYPE,
12152 elfcpp::STB_GLOBAL,
12153 elfcpp::STV_HIDDEN,
12154 0, // nonvis
12155 true, // offset_is_from_end
12156 true); // only_if_ref
12157 }
12158 else
12159 {
12160 // Define __exidx_start and __exidx_end even when .ARM.exidx
12161 // section is missing to match ld's behaviour.
12162 symtab->define_as_constant("__exidx_start", NULL,
12163 Symbol_table::PREDEFINED,
12164 0, 0, elfcpp::STT_OBJECT,
12165 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12166 true, false);
12167 symtab->define_as_constant("__exidx_end", NULL,
12168 Symbol_table::PREDEFINED,
12169 0, 0, elfcpp::STT_OBJECT,
12170 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12171 true, false);
12172 }
12173 }
12174
12175 // NaCl variant. It uses different PLT contents.
12176
12177 template<bool big_endian>
12178 class Output_data_plt_arm_nacl;
12179
12180 template<bool big_endian>
12181 class Target_arm_nacl : public Target_arm<big_endian>
12182 {
12183 public:
12184 Target_arm_nacl()
12185 : Target_arm<big_endian>(&arm_nacl_info)
12186 { }
12187
12188 protected:
12189 virtual Output_data_plt_arm<big_endian>*
12190 do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12191 { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12192
12193 private:
12194 static const Target::Target_info arm_nacl_info;
12195 };
12196
12197 template<bool big_endian>
12198 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12199 {
12200 32, // size
12201 big_endian, // is_big_endian
12202 elfcpp::EM_ARM, // machine_code
12203 false, // has_make_symbol
12204 false, // has_resolve
12205 false, // has_code_fill
12206 true, // is_default_stack_executable
12207 false, // can_icf_inline_merge_sections
12208 '\0', // wrap_char
12209 "/lib/ld-nacl-arm.so.1", // dynamic_linker
12210 0x20000, // default_text_segment_address
12211 0x10000, // abi_pagesize (overridable by -z max-page-size)
12212 0x10000, // common_pagesize (overridable by -z common-page-size)
12213 true, // isolate_execinstr
12214 0x10000000, // rosegment_gap
12215 elfcpp::SHN_UNDEF, // small_common_shndx
12216 elfcpp::SHN_UNDEF, // large_common_shndx
12217 0, // small_common_section_flags
12218 0, // large_common_section_flags
12219 ".ARM.attributes", // attributes_section
12220 "aeabi", // attributes_vendor
12221 "_start" // entry_symbol_name
12222 };
12223
12224 template<bool big_endian>
12225 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12226 {
12227 public:
12228 Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12229 : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12230 { }
12231
12232 protected:
12233 // Return the offset of the first non-reserved PLT entry.
12234 virtual unsigned int
12235 do_first_plt_entry_offset() const
12236 { return sizeof(first_plt_entry); }
12237
12238 // Return the size of a PLT entry.
12239 virtual unsigned int
12240 do_get_plt_entry_size() const
12241 { return sizeof(plt_entry); }
12242
12243 virtual void
12244 do_fill_first_plt_entry(unsigned char* pov,
12245 Arm_address got_address,
12246 Arm_address plt_address);
12247
12248 virtual void
12249 do_fill_plt_entry(unsigned char* pov,
12250 Arm_address got_address,
12251 Arm_address plt_address,
12252 unsigned int got_offset,
12253 unsigned int plt_offset);
12254
12255 private:
12256 inline uint32_t arm_movw_immediate(uint32_t value)
12257 {
12258 return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12259 }
12260
12261 inline uint32_t arm_movt_immediate(uint32_t value)
12262 {
12263 return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12264 }
12265
12266 // Template for the first PLT entry.
12267 static const uint32_t first_plt_entry[16];
12268
12269 // Template for subsequent PLT entries.
12270 static const uint32_t plt_entry[4];
12271 };
12272
12273 // The first entry in the PLT.
12274 template<bool big_endian>
12275 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12276 {
12277 // First bundle:
12278 0xe300c000, // movw ip, #:lower16:&GOT[2]-.+8
12279 0xe340c000, // movt ip, #:upper16:&GOT[2]-.+8
12280 0xe08cc00f, // add ip, ip, pc
12281 0xe52dc008, // str ip, [sp, #-8]!
12282 // Second bundle:
12283 0xe3ccc103, // bic ip, ip, #0xc0000000
12284 0xe59cc000, // ldr ip, [ip]
12285 0xe3ccc13f, // bic ip, ip, #0xc000000f
12286 0xe12fff1c, // bx ip
12287 // Third bundle:
12288 0xe320f000, // nop
12289 0xe320f000, // nop
12290 0xe320f000, // nop
12291 // .Lplt_tail:
12292 0xe50dc004, // str ip, [sp, #-4]
12293 // Fourth bundle:
12294 0xe3ccc103, // bic ip, ip, #0xc0000000
12295 0xe59cc000, // ldr ip, [ip]
12296 0xe3ccc13f, // bic ip, ip, #0xc000000f
12297 0xe12fff1c, // bx ip
12298 };
12299
12300 template<bool big_endian>
12301 void
12302 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12303 unsigned char* pov,
12304 Arm_address got_address,
12305 Arm_address plt_address)
12306 {
12307 // Write first PLT entry. All but first two words are constants.
12308 const size_t num_first_plt_words = (sizeof(first_plt_entry)
12309 / sizeof(first_plt_entry[0]));
12310
12311 int32_t got_displacement = got_address + 8 - (plt_address + 16);
12312
12313 elfcpp::Swap<32, big_endian>::writeval
12314 (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12315 elfcpp::Swap<32, big_endian>::writeval
12316 (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12317
12318 for (size_t i = 2; i < num_first_plt_words; ++i)
12319 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12320 }
12321
12322 // Subsequent entries in the PLT.
12323
12324 template<bool big_endian>
12325 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12326 {
12327 0xe300c000, // movw ip, #:lower16:&GOT[n]-.+8
12328 0xe340c000, // movt ip, #:upper16:&GOT[n]-.+8
12329 0xe08cc00f, // add ip, ip, pc
12330 0xea000000, // b .Lplt_tail
12331 };
12332
12333 template<bool big_endian>
12334 void
12335 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12336 unsigned char* pov,
12337 Arm_address got_address,
12338 Arm_address plt_address,
12339 unsigned int got_offset,
12340 unsigned int plt_offset)
12341 {
12342 // Calculate the displacement between the PLT slot and the
12343 // common tail that's part of the special initial PLT slot.
12344 int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12345 - (plt_address + plt_offset
12346 + sizeof(plt_entry) + sizeof(uint32_t)));
12347 gold_assert((tail_displacement & 3) == 0);
12348 tail_displacement >>= 2;
12349
12350 gold_assert ((tail_displacement & 0xff000000) == 0
12351 || (-tail_displacement & 0xff000000) == 0);
12352
12353 // Calculate the displacement between the PLT slot and the entry
12354 // in the GOT. The offset accounts for the value produced by
12355 // adding to pc in the penultimate instruction of the PLT stub.
12356 const int32_t got_displacement = (got_address + got_offset
12357 - (plt_address + sizeof(plt_entry)));
12358
12359 elfcpp::Swap<32, big_endian>::writeval
12360 (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12361 elfcpp::Swap<32, big_endian>::writeval
12362 (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12363 elfcpp::Swap<32, big_endian>::writeval
12364 (pov + 8, plt_entry[2]);
12365 elfcpp::Swap<32, big_endian>::writeval
12366 (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12367 }
12368
12369 // Target selectors.
12370
12371 template<bool big_endian>
12372 class Target_selector_arm_nacl
12373 : public Target_selector_nacl<Target_selector_arm<big_endian>,
12374 Target_arm_nacl<big_endian> >
12375 {
12376 public:
12377 Target_selector_arm_nacl()
12378 : Target_selector_nacl<Target_selector_arm<big_endian>,
12379 Target_arm_nacl<big_endian> >(
12380 "arm",
12381 big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12382 big_endian ? "armelfb_nacl" : "armelf_nacl")
12383 { }
12384 };
12385
12386 Target_selector_arm_nacl<false> target_selector_arm;
12387 Target_selector_arm_nacl<true> target_selector_armbe;
12388
12389 } // End anonymous namespace.
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