2010-11-08 Doug Kwan <dougkwan@google.com>
[deliverable/binutils-gdb.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright 2009, 2010 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
55 namespace
56 {
57
58 using namespace gold;
59
60 template<bool big_endian>
61 class Output_data_plt_arm;
62
63 template<bool big_endian>
64 class Stub_table;
65
66 template<bool big_endian>
67 class Arm_input_section;
68
69 class Arm_exidx_cantunwind;
70
71 class Arm_exidx_merged_section;
72
73 class Arm_exidx_fixup;
74
75 template<bool big_endian>
76 class Arm_output_section;
77
78 class Arm_exidx_input_section;
79
80 template<bool big_endian>
81 class Arm_relobj;
82
83 template<bool big_endian>
84 class Arm_relocate_functions;
85
86 template<bool big_endian>
87 class Arm_output_data_got;
88
89 template<bool big_endian>
90 class Target_arm;
91
92 // For convenience.
93 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
94
95 // Maximum branch offsets for ARM, THUMB and THUMB2.
96 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
97 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
98 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
99 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
100 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
101 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
102
103 // Thread Control Block size.
104 const size_t ARM_TCB_SIZE = 8;
105
106 // The arm target class.
107 //
108 // This is a very simple port of gold for ARM-EABI. It is intended for
109 // supporting Android only for the time being.
110 //
111 // TODOs:
112 // - Implement all static relocation types documented in arm-reloc.def.
113 // - Make PLTs more flexible for different architecture features like
114 // Thumb-2 and BE8.
115 // There are probably a lot more.
116
117 // Ideally we would like to avoid using global variables but this is used
118 // very in many places and sometimes in loops. If we use a function
119 // returning a static instance of Arm_reloc_property_table, it will very
120 // slow in an threaded environment since the static instance needs to be
121 // locked. The pointer is below initialized in the
122 // Target::do_select_as_default_target() hook so that we do not spend time
123 // building the table if we are not linking ARM objects.
124 //
125 // An alternative is to to process the information in arm-reloc.def in
126 // compilation time and generate a representation of it in PODs only. That
127 // way we can avoid initialization when the linker starts.
128
129 Arm_reloc_property_table* arm_reloc_property_table = NULL;
130
131 // Instruction template class. This class is similar to the insn_sequence
132 // struct in bfd/elf32-arm.c.
133
134 class Insn_template
135 {
136 public:
137 // Types of instruction templates.
138 enum Type
139 {
140 THUMB16_TYPE = 1,
141 // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
142 // templates with class-specific semantics. Currently this is used
143 // only by the Cortex_a8_stub class for handling condition codes in
144 // conditional branches.
145 THUMB16_SPECIAL_TYPE,
146 THUMB32_TYPE,
147 ARM_TYPE,
148 DATA_TYPE
149 };
150
151 // Factory methods to create instruction templates in different formats.
152
153 static const Insn_template
154 thumb16_insn(uint32_t data)
155 { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
156
157 // A Thumb conditional branch, in which the proper condition is inserted
158 // when we build the stub.
159 static const Insn_template
160 thumb16_bcond_insn(uint32_t data)
161 { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
162
163 static const Insn_template
164 thumb32_insn(uint32_t data)
165 { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
166
167 static const Insn_template
168 thumb32_b_insn(uint32_t data, int reloc_addend)
169 {
170 return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
171 reloc_addend);
172 }
173
174 static const Insn_template
175 arm_insn(uint32_t data)
176 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
177
178 static const Insn_template
179 arm_rel_insn(unsigned data, int reloc_addend)
180 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
181
182 static const Insn_template
183 data_word(unsigned data, unsigned int r_type, int reloc_addend)
184 { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
185
186 // Accessors. This class is used for read-only objects so no modifiers
187 // are provided.
188
189 uint32_t
190 data() const
191 { return this->data_; }
192
193 // Return the instruction sequence type of this.
194 Type
195 type() const
196 { return this->type_; }
197
198 // Return the ARM relocation type of this.
199 unsigned int
200 r_type() const
201 { return this->r_type_; }
202
203 int32_t
204 reloc_addend() const
205 { return this->reloc_addend_; }
206
207 // Return size of instruction template in bytes.
208 size_t
209 size() const;
210
211 // Return byte-alignment of instruction template.
212 unsigned
213 alignment() const;
214
215 private:
216 // We make the constructor private to ensure that only the factory
217 // methods are used.
218 inline
219 Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
220 : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
221 { }
222
223 // Instruction specific data. This is used to store information like
224 // some of the instruction bits.
225 uint32_t data_;
226 // Instruction template type.
227 Type type_;
228 // Relocation type if there is a relocation or R_ARM_NONE otherwise.
229 unsigned int r_type_;
230 // Relocation addend.
231 int32_t reloc_addend_;
232 };
233
234 // Macro for generating code to stub types. One entry per long/short
235 // branch stub
236
237 #define DEF_STUBS \
238 DEF_STUB(long_branch_any_any) \
239 DEF_STUB(long_branch_v4t_arm_thumb) \
240 DEF_STUB(long_branch_thumb_only) \
241 DEF_STUB(long_branch_v4t_thumb_thumb) \
242 DEF_STUB(long_branch_v4t_thumb_arm) \
243 DEF_STUB(short_branch_v4t_thumb_arm) \
244 DEF_STUB(long_branch_any_arm_pic) \
245 DEF_STUB(long_branch_any_thumb_pic) \
246 DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
247 DEF_STUB(long_branch_v4t_arm_thumb_pic) \
248 DEF_STUB(long_branch_v4t_thumb_arm_pic) \
249 DEF_STUB(long_branch_thumb_only_pic) \
250 DEF_STUB(a8_veneer_b_cond) \
251 DEF_STUB(a8_veneer_b) \
252 DEF_STUB(a8_veneer_bl) \
253 DEF_STUB(a8_veneer_blx) \
254 DEF_STUB(v4_veneer_bx)
255
256 // Stub types.
257
258 #define DEF_STUB(x) arm_stub_##x,
259 typedef enum
260 {
261 arm_stub_none,
262 DEF_STUBS
263
264 // First reloc stub type.
265 arm_stub_reloc_first = arm_stub_long_branch_any_any,
266 // Last reloc stub type.
267 arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
268
269 // First Cortex-A8 stub type.
270 arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
271 // Last Cortex-A8 stub type.
272 arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
273
274 // Last stub type.
275 arm_stub_type_last = arm_stub_v4_veneer_bx
276 } Stub_type;
277 #undef DEF_STUB
278
279 // Stub template class. Templates are meant to be read-only objects.
280 // A stub template for a stub type contains all read-only attributes
281 // common to all stubs of the same type.
282
283 class Stub_template
284 {
285 public:
286 Stub_template(Stub_type, const Insn_template*, size_t);
287
288 ~Stub_template()
289 { }
290
291 // Return stub type.
292 Stub_type
293 type() const
294 { return this->type_; }
295
296 // Return an array of instruction templates.
297 const Insn_template*
298 insns() const
299 { return this->insns_; }
300
301 // Return size of template in number of instructions.
302 size_t
303 insn_count() const
304 { return this->insn_count_; }
305
306 // Return size of template in bytes.
307 size_t
308 size() const
309 { return this->size_; }
310
311 // Return alignment of the stub template.
312 unsigned
313 alignment() const
314 { return this->alignment_; }
315
316 // Return whether entry point is in thumb mode.
317 bool
318 entry_in_thumb_mode() const
319 { return this->entry_in_thumb_mode_; }
320
321 // Return number of relocations in this template.
322 size_t
323 reloc_count() const
324 { return this->relocs_.size(); }
325
326 // Return index of the I-th instruction with relocation.
327 size_t
328 reloc_insn_index(size_t i) const
329 {
330 gold_assert(i < this->relocs_.size());
331 return this->relocs_[i].first;
332 }
333
334 // Return the offset of the I-th instruction with relocation from the
335 // beginning of the stub.
336 section_size_type
337 reloc_offset(size_t i) const
338 {
339 gold_assert(i < this->relocs_.size());
340 return this->relocs_[i].second;
341 }
342
343 private:
344 // This contains information about an instruction template with a relocation
345 // and its offset from start of stub.
346 typedef std::pair<size_t, section_size_type> Reloc;
347
348 // A Stub_template may not be copied. We want to share templates as much
349 // as possible.
350 Stub_template(const Stub_template&);
351 Stub_template& operator=(const Stub_template&);
352
353 // Stub type.
354 Stub_type type_;
355 // Points to an array of Insn_templates.
356 const Insn_template* insns_;
357 // Number of Insn_templates in insns_[].
358 size_t insn_count_;
359 // Size of templated instructions in bytes.
360 size_t size_;
361 // Alignment of templated instructions.
362 unsigned alignment_;
363 // Flag to indicate if entry is in thumb mode.
364 bool entry_in_thumb_mode_;
365 // A table of reloc instruction indices and offsets. We can find these by
366 // looking at the instruction templates but we pre-compute and then stash
367 // them here for speed.
368 std::vector<Reloc> relocs_;
369 };
370
371 //
372 // A class for code stubs. This is a base class for different type of
373 // stubs used in the ARM target.
374 //
375
376 class Stub
377 {
378 private:
379 static const section_offset_type invalid_offset =
380 static_cast<section_offset_type>(-1);
381
382 public:
383 Stub(const Stub_template* stub_template)
384 : stub_template_(stub_template), offset_(invalid_offset)
385 { }
386
387 virtual
388 ~Stub()
389 { }
390
391 // Return the stub template.
392 const Stub_template*
393 stub_template() const
394 { return this->stub_template_; }
395
396 // Return offset of code stub from beginning of its containing stub table.
397 section_offset_type
398 offset() const
399 {
400 gold_assert(this->offset_ != invalid_offset);
401 return this->offset_;
402 }
403
404 // Set offset of code stub from beginning of its containing stub table.
405 void
406 set_offset(section_offset_type offset)
407 { this->offset_ = offset; }
408
409 // Return the relocation target address of the i-th relocation in the
410 // stub. This must be defined in a child class.
411 Arm_address
412 reloc_target(size_t i)
413 { return this->do_reloc_target(i); }
414
415 // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written.
416 void
417 write(unsigned char* view, section_size_type view_size, bool big_endian)
418 { this->do_write(view, view_size, big_endian); }
419
420 // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
421 // for the i-th instruction.
422 uint16_t
423 thumb16_special(size_t i)
424 { return this->do_thumb16_special(i); }
425
426 protected:
427 // This must be defined in the child class.
428 virtual Arm_address
429 do_reloc_target(size_t) = 0;
430
431 // This may be overridden in the child class.
432 virtual void
433 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
434 {
435 if (big_endian)
436 this->do_fixed_endian_write<true>(view, view_size);
437 else
438 this->do_fixed_endian_write<false>(view, view_size);
439 }
440
441 // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
442 // instruction template.
443 virtual uint16_t
444 do_thumb16_special(size_t)
445 { gold_unreachable(); }
446
447 private:
448 // A template to implement do_write.
449 template<bool big_endian>
450 void inline
451 do_fixed_endian_write(unsigned char*, section_size_type);
452
453 // Its template.
454 const Stub_template* stub_template_;
455 // Offset within the section of containing this stub.
456 section_offset_type offset_;
457 };
458
459 // Reloc stub class. These are stubs we use to fix up relocation because
460 // of limited branch ranges.
461
462 class Reloc_stub : public Stub
463 {
464 public:
465 static const unsigned int invalid_index = static_cast<unsigned int>(-1);
466 // We assume we never jump to this address.
467 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
468
469 // Return destination address.
470 Arm_address
471 destination_address() const
472 {
473 gold_assert(this->destination_address_ != this->invalid_address);
474 return this->destination_address_;
475 }
476
477 // Set destination address.
478 void
479 set_destination_address(Arm_address address)
480 {
481 gold_assert(address != this->invalid_address);
482 this->destination_address_ = address;
483 }
484
485 // Reset destination address.
486 void
487 reset_destination_address()
488 { this->destination_address_ = this->invalid_address; }
489
490 // Determine stub type for a branch of a relocation of R_TYPE going
491 // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set,
492 // the branch target is a thumb instruction. TARGET is used for look
493 // up ARM-specific linker settings.
494 static Stub_type
495 stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
496 Arm_address branch_target, bool target_is_thumb);
497
498 // Reloc_stub key. A key is logically a triplet of a stub type, a symbol
499 // and an addend. Since we treat global and local symbol differently, we
500 // use a Symbol object for a global symbol and a object-index pair for
501 // a local symbol.
502 class Key
503 {
504 public:
505 // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
506 // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL
507 // and R_SYM must not be invalid_index.
508 Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
509 unsigned int r_sym, int32_t addend)
510 : stub_type_(stub_type), addend_(addend)
511 {
512 if (symbol != NULL)
513 {
514 this->r_sym_ = Reloc_stub::invalid_index;
515 this->u_.symbol = symbol;
516 }
517 else
518 {
519 gold_assert(relobj != NULL && r_sym != invalid_index);
520 this->r_sym_ = r_sym;
521 this->u_.relobj = relobj;
522 }
523 }
524
525 ~Key()
526 { }
527
528 // Accessors: Keys are meant to be read-only object so no modifiers are
529 // provided.
530
531 // Return stub type.
532 Stub_type
533 stub_type() const
534 { return this->stub_type_; }
535
536 // Return the local symbol index or invalid_index.
537 unsigned int
538 r_sym() const
539 { return this->r_sym_; }
540
541 // Return the symbol if there is one.
542 const Symbol*
543 symbol() const
544 { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
545
546 // Return the relobj if there is one.
547 const Relobj*
548 relobj() const
549 { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
550
551 // Whether this equals to another key k.
552 bool
553 eq(const Key& k) const
554 {
555 return ((this->stub_type_ == k.stub_type_)
556 && (this->r_sym_ == k.r_sym_)
557 && ((this->r_sym_ != Reloc_stub::invalid_index)
558 ? (this->u_.relobj == k.u_.relobj)
559 : (this->u_.symbol == k.u_.symbol))
560 && (this->addend_ == k.addend_));
561 }
562
563 // Return a hash value.
564 size_t
565 hash_value() const
566 {
567 return (this->stub_type_
568 ^ this->r_sym_
569 ^ gold::string_hash<char>(
570 (this->r_sym_ != Reloc_stub::invalid_index)
571 ? this->u_.relobj->name().c_str()
572 : this->u_.symbol->name())
573 ^ this->addend_);
574 }
575
576 // Functors for STL associative containers.
577 struct hash
578 {
579 size_t
580 operator()(const Key& k) const
581 { return k.hash_value(); }
582 };
583
584 struct equal_to
585 {
586 bool
587 operator()(const Key& k1, const Key& k2) const
588 { return k1.eq(k2); }
589 };
590
591 // Name of key. This is mainly for debugging.
592 std::string
593 name() const;
594
595 private:
596 // Stub type.
597 Stub_type stub_type_;
598 // If this is a local symbol, this is the index in the defining object.
599 // Otherwise, it is invalid_index for a global symbol.
600 unsigned int r_sym_;
601 // If r_sym_ is invalid index. This points to a global symbol.
602 // Otherwise, this points a relobj. We used the unsized and target
603 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
604 // Arm_relobj. This is done to avoid making the stub class a template
605 // as most of the stub machinery is endianness-neutral. However, it
606 // may require a bit of casting done by users of this class.
607 union
608 {
609 const Symbol* symbol;
610 const Relobj* relobj;
611 } u_;
612 // Addend associated with a reloc.
613 int32_t addend_;
614 };
615
616 protected:
617 // Reloc_stubs are created via a stub factory. So these are protected.
618 Reloc_stub(const Stub_template* stub_template)
619 : Stub(stub_template), destination_address_(invalid_address)
620 { }
621
622 ~Reloc_stub()
623 { }
624
625 friend class Stub_factory;
626
627 // Return the relocation target address of the i-th relocation in the
628 // stub.
629 Arm_address
630 do_reloc_target(size_t i)
631 {
632 // All reloc stub have only one relocation.
633 gold_assert(i == 0);
634 return this->destination_address_;
635 }
636
637 private:
638 // Address of destination.
639 Arm_address destination_address_;
640 };
641
642 // Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit
643 // THUMB branch that meets the following conditions:
644 //
645 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
646 // branch address is 0xffe.
647 // 2. The branch target address is in the same page as the first word of the
648 // branch.
649 // 3. The branch follows a 32-bit instruction which is not a branch.
650 //
651 // To do the fix up, we need to store the address of the branch instruction
652 // and its target at least. We also need to store the original branch
653 // instruction bits for the condition code in a conditional branch. The
654 // condition code is used in a special instruction template. We also want
655 // to identify input sections needing Cortex-A8 workaround quickly. We store
656 // extra information about object and section index of the code section
657 // containing a branch being fixed up. The information is used to mark
658 // the code section when we finalize the Cortex-A8 stubs.
659 //
660
661 class Cortex_a8_stub : public Stub
662 {
663 public:
664 ~Cortex_a8_stub()
665 { }
666
667 // Return the object of the code section containing the branch being fixed
668 // up.
669 Relobj*
670 relobj() const
671 { return this->relobj_; }
672
673 // Return the section index of the code section containing the branch being
674 // fixed up.
675 unsigned int
676 shndx() const
677 { return this->shndx_; }
678
679 // Return the source address of stub. This is the address of the original
680 // branch instruction. LSB is 1 always set to indicate that it is a THUMB
681 // instruction.
682 Arm_address
683 source_address() const
684 { return this->source_address_; }
685
686 // Return the destination address of the stub. This is the branch taken
687 // address of the original branch instruction. LSB is 1 if it is a THUMB
688 // instruction address.
689 Arm_address
690 destination_address() const
691 { return this->destination_address_; }
692
693 // Return the instruction being fixed up.
694 uint32_t
695 original_insn() const
696 { return this->original_insn_; }
697
698 protected:
699 // Cortex_a8_stubs are created via a stub factory. So these are protected.
700 Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
701 unsigned int shndx, Arm_address source_address,
702 Arm_address destination_address, uint32_t original_insn)
703 : Stub(stub_template), relobj_(relobj), shndx_(shndx),
704 source_address_(source_address | 1U),
705 destination_address_(destination_address),
706 original_insn_(original_insn)
707 { }
708
709 friend class Stub_factory;
710
711 // Return the relocation target address of the i-th relocation in the
712 // stub.
713 Arm_address
714 do_reloc_target(size_t i)
715 {
716 if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
717 {
718 // The conditional branch veneer has two relocations.
719 gold_assert(i < 2);
720 return i == 0 ? this->source_address_ + 4 : this->destination_address_;
721 }
722 else
723 {
724 // All other Cortex-A8 stubs have only one relocation.
725 gold_assert(i == 0);
726 return this->destination_address_;
727 }
728 }
729
730 // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
731 uint16_t
732 do_thumb16_special(size_t);
733
734 private:
735 // Object of the code section containing the branch being fixed up.
736 Relobj* relobj_;
737 // Section index of the code section containing the branch begin fixed up.
738 unsigned int shndx_;
739 // Source address of original branch.
740 Arm_address source_address_;
741 // Destination address of the original branch.
742 Arm_address destination_address_;
743 // Original branch instruction. This is needed for copying the condition
744 // code from a condition branch to its stub.
745 uint32_t original_insn_;
746 };
747
748 // ARMv4 BX Rx branch relocation stub class.
749 class Arm_v4bx_stub : public Stub
750 {
751 public:
752 ~Arm_v4bx_stub()
753 { }
754
755 // Return the associated register.
756 uint32_t
757 reg() const
758 { return this->reg_; }
759
760 protected:
761 // Arm V4BX stubs are created via a stub factory. So these are protected.
762 Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
763 : Stub(stub_template), reg_(reg)
764 { }
765
766 friend class Stub_factory;
767
768 // Return the relocation target address of the i-th relocation in the
769 // stub.
770 Arm_address
771 do_reloc_target(size_t)
772 { gold_unreachable(); }
773
774 // This may be overridden in the child class.
775 virtual void
776 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
777 {
778 if (big_endian)
779 this->do_fixed_endian_v4bx_write<true>(view, view_size);
780 else
781 this->do_fixed_endian_v4bx_write<false>(view, view_size);
782 }
783
784 private:
785 // A template to implement do_write.
786 template<bool big_endian>
787 void inline
788 do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
789 {
790 const Insn_template* insns = this->stub_template()->insns();
791 elfcpp::Swap<32, big_endian>::writeval(view,
792 (insns[0].data()
793 + (this->reg_ << 16)));
794 view += insns[0].size();
795 elfcpp::Swap<32, big_endian>::writeval(view,
796 (insns[1].data() + this->reg_));
797 view += insns[1].size();
798 elfcpp::Swap<32, big_endian>::writeval(view,
799 (insns[2].data() + this->reg_));
800 }
801
802 // A register index (r0-r14), which is associated with the stub.
803 uint32_t reg_;
804 };
805
806 // Stub factory class.
807
808 class Stub_factory
809 {
810 public:
811 // Return the unique instance of this class.
812 static const Stub_factory&
813 get_instance()
814 {
815 static Stub_factory singleton;
816 return singleton;
817 }
818
819 // Make a relocation stub.
820 Reloc_stub*
821 make_reloc_stub(Stub_type stub_type) const
822 {
823 gold_assert(stub_type >= arm_stub_reloc_first
824 && stub_type <= arm_stub_reloc_last);
825 return new Reloc_stub(this->stub_templates_[stub_type]);
826 }
827
828 // Make a Cortex-A8 stub.
829 Cortex_a8_stub*
830 make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
831 Arm_address source, Arm_address destination,
832 uint32_t original_insn) const
833 {
834 gold_assert(stub_type >= arm_stub_cortex_a8_first
835 && stub_type <= arm_stub_cortex_a8_last);
836 return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
837 source, destination, original_insn);
838 }
839
840 // Make an ARM V4BX relocation stub.
841 // This method creates a stub from the arm_stub_v4_veneer_bx template only.
842 Arm_v4bx_stub*
843 make_arm_v4bx_stub(uint32_t reg) const
844 {
845 gold_assert(reg < 0xf);
846 return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
847 reg);
848 }
849
850 private:
851 // Constructor and destructor are protected since we only return a single
852 // instance created in Stub_factory::get_instance().
853
854 Stub_factory();
855
856 // A Stub_factory may not be copied since it is a singleton.
857 Stub_factory(const Stub_factory&);
858 Stub_factory& operator=(Stub_factory&);
859
860 // Stub templates. These are initialized in the constructor.
861 const Stub_template* stub_templates_[arm_stub_type_last+1];
862 };
863
864 // A class to hold stubs for the ARM target.
865
866 template<bool big_endian>
867 class Stub_table : public Output_data
868 {
869 public:
870 Stub_table(Arm_input_section<big_endian>* owner)
871 : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
872 reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
873 prev_data_size_(0), prev_addralign_(1)
874 { }
875
876 ~Stub_table()
877 { }
878
879 // Owner of this stub table.
880 Arm_input_section<big_endian>*
881 owner() const
882 { return this->owner_; }
883
884 // Whether this stub table is empty.
885 bool
886 empty() const
887 {
888 return (this->reloc_stubs_.empty()
889 && this->cortex_a8_stubs_.empty()
890 && this->arm_v4bx_stubs_.empty());
891 }
892
893 // Return the current data size.
894 off_t
895 current_data_size() const
896 { return this->current_data_size_for_child(); }
897
898 // Add a STUB with using KEY. Caller is reponsible for avoid adding
899 // if already a STUB with the same key has been added.
900 void
901 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
902 {
903 const Stub_template* stub_template = stub->stub_template();
904 gold_assert(stub_template->type() == key.stub_type());
905 this->reloc_stubs_[key] = stub;
906
907 // Assign stub offset early. We can do this because we never remove
908 // reloc stubs and they are in the beginning of the stub table.
909 uint64_t align = stub_template->alignment();
910 this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
911 stub->set_offset(this->reloc_stubs_size_);
912 this->reloc_stubs_size_ += stub_template->size();
913 this->reloc_stubs_addralign_ =
914 std::max(this->reloc_stubs_addralign_, align);
915 }
916
917 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
918 // Caller is reponsible for avoid adding if already a STUB with the same
919 // address has been added.
920 void
921 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
922 {
923 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
924 this->cortex_a8_stubs_.insert(value);
925 }
926
927 // Add an ARM V4BX relocation stub. A register index will be retrieved
928 // from the stub.
929 void
930 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
931 {
932 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
933 this->arm_v4bx_stubs_[stub->reg()] = stub;
934 }
935
936 // Remove all Cortex-A8 stubs.
937 void
938 remove_all_cortex_a8_stubs();
939
940 // Look up a relocation stub using KEY. Return NULL if there is none.
941 Reloc_stub*
942 find_reloc_stub(const Reloc_stub::Key& key) const
943 {
944 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
945 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
946 }
947
948 // Look up an arm v4bx relocation stub using the register index.
949 // Return NULL if there is none.
950 Arm_v4bx_stub*
951 find_arm_v4bx_stub(const uint32_t reg) const
952 {
953 gold_assert(reg < 0xf);
954 return this->arm_v4bx_stubs_[reg];
955 }
956
957 // Relocate stubs in this stub table.
958 void
959 relocate_stubs(const Relocate_info<32, big_endian>*,
960 Target_arm<big_endian>*, Output_section*,
961 unsigned char*, Arm_address, section_size_type);
962
963 // Update data size and alignment at the end of a relaxation pass. Return
964 // true if either data size or alignment is different from that of the
965 // previous relaxation pass.
966 bool
967 update_data_size_and_addralign();
968
969 // Finalize stubs. Set the offsets of all stubs and mark input sections
970 // needing the Cortex-A8 workaround.
971 void
972 finalize_stubs();
973
974 // Apply Cortex-A8 workaround to an address range.
975 void
976 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
977 unsigned char*, Arm_address,
978 section_size_type);
979
980 protected:
981 // Write out section contents.
982 void
983 do_write(Output_file*);
984
985 // Return the required alignment.
986 uint64_t
987 do_addralign() const
988 { return this->prev_addralign_; }
989
990 // Reset address and file offset.
991 void
992 do_reset_address_and_file_offset()
993 { this->set_current_data_size_for_child(this->prev_data_size_); }
994
995 // Set final data size.
996 void
997 set_final_data_size()
998 { this->set_data_size(this->current_data_size()); }
999
1000 private:
1001 // Relocate one stub.
1002 void
1003 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1004 Target_arm<big_endian>*, Output_section*,
1005 unsigned char*, Arm_address, section_size_type);
1006
1007 // Unordered map of relocation stubs.
1008 typedef
1009 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1010 Reloc_stub::Key::equal_to>
1011 Reloc_stub_map;
1012
1013 // List of Cortex-A8 stubs ordered by addresses of branches being
1014 // fixed up in output.
1015 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1016 // List of Arm V4BX relocation stubs ordered by associated registers.
1017 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1018
1019 // Owner of this stub table.
1020 Arm_input_section<big_endian>* owner_;
1021 // The relocation stubs.
1022 Reloc_stub_map reloc_stubs_;
1023 // Size of reloc stubs.
1024 off_t reloc_stubs_size_;
1025 // Maximum address alignment of reloc stubs.
1026 uint64_t reloc_stubs_addralign_;
1027 // The cortex_a8_stubs.
1028 Cortex_a8_stub_list cortex_a8_stubs_;
1029 // The Arm V4BX relocation stubs.
1030 Arm_v4bx_stub_list arm_v4bx_stubs_;
1031 // data size of this in the previous pass.
1032 off_t prev_data_size_;
1033 // address alignment of this in the previous pass.
1034 uint64_t prev_addralign_;
1035 };
1036
1037 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1038 // we add to the end of an EXIDX input section that goes into the output.
1039
1040 class Arm_exidx_cantunwind : public Output_section_data
1041 {
1042 public:
1043 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1044 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1045 { }
1046
1047 // Return the object containing the section pointed by this.
1048 Relobj*
1049 relobj() const
1050 { return this->relobj_; }
1051
1052 // Return the section index of the section pointed by this.
1053 unsigned int
1054 shndx() const
1055 { return this->shndx_; }
1056
1057 protected:
1058 void
1059 do_write(Output_file* of)
1060 {
1061 if (parameters->target().is_big_endian())
1062 this->do_fixed_endian_write<true>(of);
1063 else
1064 this->do_fixed_endian_write<false>(of);
1065 }
1066
1067 // Write to a map file.
1068 void
1069 do_print_to_mapfile(Mapfile* mapfile) const
1070 { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1071
1072 private:
1073 // Implement do_write for a given endianness.
1074 template<bool big_endian>
1075 void inline
1076 do_fixed_endian_write(Output_file*);
1077
1078 // The object containing the section pointed by this.
1079 Relobj* relobj_;
1080 // The section index of the section pointed by this.
1081 unsigned int shndx_;
1082 };
1083
1084 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1085 // Offset map is used to map input section offset within the EXIDX section
1086 // to the output offset from the start of this EXIDX section.
1087
1088 typedef std::map<section_offset_type, section_offset_type>
1089 Arm_exidx_section_offset_map;
1090
1091 // Arm_exidx_merged_section class. This represents an EXIDX input section
1092 // with some of its entries merged.
1093
1094 class Arm_exidx_merged_section : public Output_relaxed_input_section
1095 {
1096 public:
1097 // Constructor for Arm_exidx_merged_section.
1098 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1099 // SECTION_OFFSET_MAP points to a section offset map describing how
1100 // parts of the input section are mapped to output. DELETED_BYTES is
1101 // the number of bytes deleted from the EXIDX input section.
1102 Arm_exidx_merged_section(
1103 const Arm_exidx_input_section& exidx_input_section,
1104 const Arm_exidx_section_offset_map& section_offset_map,
1105 uint32_t deleted_bytes);
1106
1107 // Build output contents.
1108 void
1109 build_contents(const unsigned char*, section_size_type);
1110
1111 // Return the original EXIDX input section.
1112 const Arm_exidx_input_section&
1113 exidx_input_section() const
1114 { return this->exidx_input_section_; }
1115
1116 // Return the section offset map.
1117 const Arm_exidx_section_offset_map&
1118 section_offset_map() const
1119 { return this->section_offset_map_; }
1120
1121 protected:
1122 // Write merged section into file OF.
1123 void
1124 do_write(Output_file* of);
1125
1126 bool
1127 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1128 section_offset_type*) const;
1129
1130 private:
1131 // Original EXIDX input section.
1132 const Arm_exidx_input_section& exidx_input_section_;
1133 // Section offset map.
1134 const Arm_exidx_section_offset_map& section_offset_map_;
1135 // Merged section contents. We need to keep build the merged section
1136 // and save it here to avoid accessing the original EXIDX section when
1137 // we cannot lock the sections' object.
1138 unsigned char* section_contents_;
1139 };
1140
1141 // A class to wrap an ordinary input section containing executable code.
1142
1143 template<bool big_endian>
1144 class Arm_input_section : public Output_relaxed_input_section
1145 {
1146 public:
1147 Arm_input_section(Relobj* relobj, unsigned int shndx)
1148 : Output_relaxed_input_section(relobj, shndx, 1),
1149 original_addralign_(1), original_size_(0), stub_table_(NULL),
1150 original_contents_(NULL)
1151 { }
1152
1153 ~Arm_input_section()
1154 { delete[] this->original_contents_; }
1155
1156 // Initialize.
1157 void
1158 init();
1159
1160 // Whether this is a stub table owner.
1161 bool
1162 is_stub_table_owner() const
1163 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1164
1165 // Return the stub table.
1166 Stub_table<big_endian>*
1167 stub_table() const
1168 { return this->stub_table_; }
1169
1170 // Set the stub_table.
1171 void
1172 set_stub_table(Stub_table<big_endian>* stub_table)
1173 { this->stub_table_ = stub_table; }
1174
1175 // Downcast a base pointer to an Arm_input_section pointer. This is
1176 // not type-safe but we only use Arm_input_section not the base class.
1177 static Arm_input_section<big_endian>*
1178 as_arm_input_section(Output_relaxed_input_section* poris)
1179 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1180
1181 // Return the original size of the section.
1182 uint32_t
1183 original_size() const
1184 { return this->original_size_; }
1185
1186 protected:
1187 // Write data to output file.
1188 void
1189 do_write(Output_file*);
1190
1191 // Return required alignment of this.
1192 uint64_t
1193 do_addralign() const
1194 {
1195 if (this->is_stub_table_owner())
1196 return std::max(this->stub_table_->addralign(),
1197 static_cast<uint64_t>(this->original_addralign_));
1198 else
1199 return this->original_addralign_;
1200 }
1201
1202 // Finalize data size.
1203 void
1204 set_final_data_size();
1205
1206 // Reset address and file offset.
1207 void
1208 do_reset_address_and_file_offset();
1209
1210 // Output offset.
1211 bool
1212 do_output_offset(const Relobj* object, unsigned int shndx,
1213 section_offset_type offset,
1214 section_offset_type* poutput) const
1215 {
1216 if ((object == this->relobj())
1217 && (shndx == this->shndx())
1218 && (offset >= 0)
1219 && (offset <=
1220 convert_types<section_offset_type, uint32_t>(this->original_size_)))
1221 {
1222 *poutput = offset;
1223 return true;
1224 }
1225 else
1226 return false;
1227 }
1228
1229 private:
1230 // Copying is not allowed.
1231 Arm_input_section(const Arm_input_section&);
1232 Arm_input_section& operator=(const Arm_input_section&);
1233
1234 // Address alignment of the original input section.
1235 uint32_t original_addralign_;
1236 // Section size of the original input section.
1237 uint32_t original_size_;
1238 // Stub table.
1239 Stub_table<big_endian>* stub_table_;
1240 // Original section contents. We have to make a copy here since the file
1241 // containing the original section may not be locked when we need to access
1242 // the contents.
1243 unsigned char* original_contents_;
1244 };
1245
1246 // Arm_exidx_fixup class. This is used to define a number of methods
1247 // and keep states for fixing up EXIDX coverage.
1248
1249 class Arm_exidx_fixup
1250 {
1251 public:
1252 Arm_exidx_fixup(Output_section* exidx_output_section,
1253 bool merge_exidx_entries = true)
1254 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1255 last_inlined_entry_(0), last_input_section_(NULL),
1256 section_offset_map_(NULL), first_output_text_section_(NULL),
1257 merge_exidx_entries_(merge_exidx_entries)
1258 { }
1259
1260 ~Arm_exidx_fixup()
1261 { delete this->section_offset_map_; }
1262
1263 // Process an EXIDX section for entry merging. SECTION_CONTENTS points
1264 // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1265 // number of bytes to be deleted in output. If parts of the input EXIDX
1266 // section are merged a heap allocated Arm_exidx_section_offset_map is store
1267 // in the located PSECTION_OFFSET_MAP. The caller owns the map and is
1268 // reponsible for releasing it.
1269 template<bool big_endian>
1270 uint32_t
1271 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1272 const unsigned char* section_contents,
1273 section_size_type section_size,
1274 Arm_exidx_section_offset_map** psection_offset_map);
1275
1276 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1277 // input section, if there is not one already.
1278 void
1279 add_exidx_cantunwind_as_needed();
1280
1281 // Return the output section for the text section which is linked to the
1282 // first exidx input in output.
1283 Output_section*
1284 first_output_text_section() const
1285 { return this->first_output_text_section_; }
1286
1287 private:
1288 // Copying is not allowed.
1289 Arm_exidx_fixup(const Arm_exidx_fixup&);
1290 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1291
1292 // Type of EXIDX unwind entry.
1293 enum Unwind_type
1294 {
1295 // No type.
1296 UT_NONE,
1297 // EXIDX_CANTUNWIND.
1298 UT_EXIDX_CANTUNWIND,
1299 // Inlined entry.
1300 UT_INLINED_ENTRY,
1301 // Normal entry.
1302 UT_NORMAL_ENTRY,
1303 };
1304
1305 // Process an EXIDX entry. We only care about the second word of the
1306 // entry. Return true if the entry can be deleted.
1307 bool
1308 process_exidx_entry(uint32_t second_word);
1309
1310 // Update the current section offset map during EXIDX section fix-up.
1311 // If there is no map, create one. INPUT_OFFSET is the offset of a
1312 // reference point, DELETED_BYTES is the number of deleted by in the
1313 // section so far. If DELETE_ENTRY is true, the reference point and
1314 // all offsets after the previous reference point are discarded.
1315 void
1316 update_offset_map(section_offset_type input_offset,
1317 section_size_type deleted_bytes, bool delete_entry);
1318
1319 // EXIDX output section.
1320 Output_section* exidx_output_section_;
1321 // Unwind type of the last EXIDX entry processed.
1322 Unwind_type last_unwind_type_;
1323 // Last seen inlined EXIDX entry.
1324 uint32_t last_inlined_entry_;
1325 // Last processed EXIDX input section.
1326 const Arm_exidx_input_section* last_input_section_;
1327 // Section offset map created in process_exidx_section.
1328 Arm_exidx_section_offset_map* section_offset_map_;
1329 // Output section for the text section which is linked to the first exidx
1330 // input in output.
1331 Output_section* first_output_text_section_;
1332
1333 bool merge_exidx_entries_;
1334 };
1335
1336 // Arm output section class. This is defined mainly to add a number of
1337 // stub generation methods.
1338
1339 template<bool big_endian>
1340 class Arm_output_section : public Output_section
1341 {
1342 public:
1343 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1344
1345 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1346 elfcpp::Elf_Xword flags)
1347 : Output_section(name, type, flags)
1348 {
1349 if (type == elfcpp::SHT_ARM_EXIDX)
1350 this->set_always_keeps_input_sections();
1351 }
1352
1353 ~Arm_output_section()
1354 { }
1355
1356 // Group input sections for stub generation.
1357 void
1358 group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1359
1360 // Downcast a base pointer to an Arm_output_section pointer. This is
1361 // not type-safe but we only use Arm_output_section not the base class.
1362 static Arm_output_section<big_endian>*
1363 as_arm_output_section(Output_section* os)
1364 { return static_cast<Arm_output_section<big_endian>*>(os); }
1365
1366 // Append all input text sections in this into LIST.
1367 void
1368 append_text_sections_to_list(Text_section_list* list);
1369
1370 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1371 // is a list of text input sections sorted in ascending order of their
1372 // output addresses.
1373 void
1374 fix_exidx_coverage(Layout* layout,
1375 const Text_section_list& sorted_text_section,
1376 Symbol_table* symtab,
1377 bool merge_exidx_entries,
1378 const Task* task);
1379
1380 // Link an EXIDX section into its corresponding text section.
1381 void
1382 set_exidx_section_link();
1383
1384 private:
1385 // For convenience.
1386 typedef Output_section::Input_section Input_section;
1387 typedef Output_section::Input_section_list Input_section_list;
1388
1389 // Create a stub group.
1390 void create_stub_group(Input_section_list::const_iterator,
1391 Input_section_list::const_iterator,
1392 Input_section_list::const_iterator,
1393 Target_arm<big_endian>*,
1394 std::vector<Output_relaxed_input_section*>*,
1395 const Task* task);
1396 };
1397
1398 // Arm_exidx_input_section class. This represents an EXIDX input section.
1399
1400 class Arm_exidx_input_section
1401 {
1402 public:
1403 static const section_offset_type invalid_offset =
1404 static_cast<section_offset_type>(-1);
1405
1406 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1407 unsigned int link, uint32_t size,
1408 uint32_t addralign, uint32_t text_size)
1409 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1410 addralign_(addralign), text_size_(text_size), has_errors_(false)
1411 { }
1412
1413 ~Arm_exidx_input_section()
1414 { }
1415
1416 // Accessors: This is a read-only class.
1417
1418 // Return the object containing this EXIDX input section.
1419 Relobj*
1420 relobj() const
1421 { return this->relobj_; }
1422
1423 // Return the section index of this EXIDX input section.
1424 unsigned int
1425 shndx() const
1426 { return this->shndx_; }
1427
1428 // Return the section index of linked text section in the same object.
1429 unsigned int
1430 link() const
1431 { return this->link_; }
1432
1433 // Return size of the EXIDX input section.
1434 uint32_t
1435 size() const
1436 { return this->size_; }
1437
1438 // Return address alignment of EXIDX input section.
1439 uint32_t
1440 addralign() const
1441 { return this->addralign_; }
1442
1443 // Return size of the associated text input section.
1444 uint32_t
1445 text_size() const
1446 { return this->text_size_; }
1447
1448 // Whether there are any errors in the EXIDX input section.
1449 bool
1450 has_errors() const
1451 { return this->has_errors_; }
1452
1453 // Set has-errors flag.
1454 void
1455 set_has_errors()
1456 { this->has_errors_ = true; }
1457
1458 private:
1459 // Object containing this.
1460 Relobj* relobj_;
1461 // Section index of this.
1462 unsigned int shndx_;
1463 // text section linked to this in the same object.
1464 unsigned int link_;
1465 // Size of this. For ARM 32-bit is sufficient.
1466 uint32_t size_;
1467 // Address alignment of this. For ARM 32-bit is sufficient.
1468 uint32_t addralign_;
1469 // Size of associated text section.
1470 uint32_t text_size_;
1471 // Whether this has any errors.
1472 bool has_errors_;
1473 };
1474
1475 // Arm_relobj class.
1476
1477 template<bool big_endian>
1478 class Arm_relobj : public Sized_relobj<32, big_endian>
1479 {
1480 public:
1481 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1482
1483 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1484 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1485 : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr),
1486 stub_tables_(), local_symbol_is_thumb_function_(),
1487 attributes_section_data_(NULL), mapping_symbols_info_(),
1488 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1489 output_local_symbol_count_needs_update_(false),
1490 merge_flags_and_attributes_(true)
1491 { }
1492
1493 ~Arm_relobj()
1494 { delete this->attributes_section_data_; }
1495
1496 // Return the stub table of the SHNDX-th section if there is one.
1497 Stub_table<big_endian>*
1498 stub_table(unsigned int shndx) const
1499 {
1500 gold_assert(shndx < this->stub_tables_.size());
1501 return this->stub_tables_[shndx];
1502 }
1503
1504 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1505 void
1506 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1507 {
1508 gold_assert(shndx < this->stub_tables_.size());
1509 this->stub_tables_[shndx] = stub_table;
1510 }
1511
1512 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1513 // index. This is only valid after do_count_local_symbol is called.
1514 bool
1515 local_symbol_is_thumb_function(unsigned int r_sym) const
1516 {
1517 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1518 return this->local_symbol_is_thumb_function_[r_sym];
1519 }
1520
1521 // Scan all relocation sections for stub generation.
1522 void
1523 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1524 const Layout*);
1525
1526 // Convert regular input section with index SHNDX to a relaxed section.
1527 void
1528 convert_input_section_to_relaxed_section(unsigned shndx)
1529 {
1530 // The stubs have relocations and we need to process them after writing
1531 // out the stubs. So relocation now must follow section write.
1532 this->set_section_offset(shndx, -1ULL);
1533 this->set_relocs_must_follow_section_writes();
1534 }
1535
1536 // Downcast a base pointer to an Arm_relobj pointer. This is
1537 // not type-safe but we only use Arm_relobj not the base class.
1538 static Arm_relobj<big_endian>*
1539 as_arm_relobj(Relobj* relobj)
1540 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1541
1542 // Processor-specific flags in ELF file header. This is valid only after
1543 // reading symbols.
1544 elfcpp::Elf_Word
1545 processor_specific_flags() const
1546 { return this->processor_specific_flags_; }
1547
1548 // Attribute section data This is the contents of the .ARM.attribute section
1549 // if there is one.
1550 const Attributes_section_data*
1551 attributes_section_data() const
1552 { return this->attributes_section_data_; }
1553
1554 // Mapping symbol location.
1555 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1556
1557 // Functor for STL container.
1558 struct Mapping_symbol_position_less
1559 {
1560 bool
1561 operator()(const Mapping_symbol_position& p1,
1562 const Mapping_symbol_position& p2) const
1563 {
1564 return (p1.first < p2.first
1565 || (p1.first == p2.first && p1.second < p2.second));
1566 }
1567 };
1568
1569 // We only care about the first character of a mapping symbol, so
1570 // we only store that instead of the whole symbol name.
1571 typedef std::map<Mapping_symbol_position, char,
1572 Mapping_symbol_position_less> Mapping_symbols_info;
1573
1574 // Whether a section contains any Cortex-A8 workaround.
1575 bool
1576 section_has_cortex_a8_workaround(unsigned int shndx) const
1577 {
1578 return (this->section_has_cortex_a8_workaround_ != NULL
1579 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1580 }
1581
1582 // Mark a section that has Cortex-A8 workaround.
1583 void
1584 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1585 {
1586 if (this->section_has_cortex_a8_workaround_ == NULL)
1587 this->section_has_cortex_a8_workaround_ =
1588 new std::vector<bool>(this->shnum(), false);
1589 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1590 }
1591
1592 // Return the EXIDX section of an text section with index SHNDX or NULL
1593 // if the text section has no associated EXIDX section.
1594 const Arm_exidx_input_section*
1595 exidx_input_section_by_link(unsigned int shndx) const
1596 {
1597 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1598 return ((p != this->exidx_section_map_.end()
1599 && p->second->link() == shndx)
1600 ? p->second
1601 : NULL);
1602 }
1603
1604 // Return the EXIDX section with index SHNDX or NULL if there is none.
1605 const Arm_exidx_input_section*
1606 exidx_input_section_by_shndx(unsigned shndx) const
1607 {
1608 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1609 return ((p != this->exidx_section_map_.end()
1610 && p->second->shndx() == shndx)
1611 ? p->second
1612 : NULL);
1613 }
1614
1615 // Whether output local symbol count needs updating.
1616 bool
1617 output_local_symbol_count_needs_update() const
1618 { return this->output_local_symbol_count_needs_update_; }
1619
1620 // Set output_local_symbol_count_needs_update flag to be true.
1621 void
1622 set_output_local_symbol_count_needs_update()
1623 { this->output_local_symbol_count_needs_update_ = true; }
1624
1625 // Update output local symbol count at the end of relaxation.
1626 void
1627 update_output_local_symbol_count();
1628
1629 // Whether we want to merge processor-specific flags and attributes.
1630 bool
1631 merge_flags_and_attributes() const
1632 { return this->merge_flags_and_attributes_; }
1633
1634 // Export list of EXIDX section indices.
1635 void
1636 get_exidx_shndx_list(std::vector<unsigned int>* list) const
1637 {
1638 list->clear();
1639 for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1640 p != this->exidx_section_map_.end();
1641 ++p)
1642 {
1643 if (p->second->shndx() == p->first)
1644 list->push_back(p->first);
1645 }
1646 // Sort list to make result independent of implementation of map.
1647 std::sort(list->begin(), list->end());
1648 }
1649
1650 protected:
1651 // Post constructor setup.
1652 void
1653 do_setup()
1654 {
1655 // Call parent's setup method.
1656 Sized_relobj<32, big_endian>::do_setup();
1657
1658 // Initialize look-up tables.
1659 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1660 this->stub_tables_.swap(empty_stub_table_list);
1661 }
1662
1663 // Count the local symbols.
1664 void
1665 do_count_local_symbols(Stringpool_template<char>*,
1666 Stringpool_template<char>*);
1667
1668 void
1669 do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
1670 const unsigned char* pshdrs, Output_file* of,
1671 typename Sized_relobj<32, big_endian>::Views* pivews);
1672
1673 // Read the symbol information.
1674 void
1675 do_read_symbols(Read_symbols_data* sd);
1676
1677 // Process relocs for garbage collection.
1678 void
1679 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1680
1681 private:
1682
1683 // Whether a section needs to be scanned for relocation stubs.
1684 bool
1685 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1686 const Relobj::Output_sections&,
1687 const Symbol_table*, const unsigned char*);
1688
1689 // Whether a section is a scannable text section.
1690 bool
1691 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1692 const Output_section*, const Symbol_table*);
1693
1694 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1695 bool
1696 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1697 unsigned int, Output_section*,
1698 const Symbol_table*);
1699
1700 // Scan a section for the Cortex-A8 erratum.
1701 void
1702 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1703 unsigned int, Output_section*,
1704 Target_arm<big_endian>*);
1705
1706 // Find the linked text section of an EXIDX section by looking at the
1707 // first reloction of the EXIDX section. PSHDR points to the section
1708 // headers of a relocation section and PSYMS points to the local symbols.
1709 // PSHNDX points to a location storing the text section index if found.
1710 // Return whether we can find the linked section.
1711 bool
1712 find_linked_text_section(const unsigned char* pshdr,
1713 const unsigned char* psyms, unsigned int* pshndx);
1714
1715 //
1716 // Make a new Arm_exidx_input_section object for EXIDX section with
1717 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1718 // index of the linked text section.
1719 void
1720 make_exidx_input_section(unsigned int shndx,
1721 const elfcpp::Shdr<32, big_endian>& shdr,
1722 unsigned int text_shndx,
1723 const elfcpp::Shdr<32, big_endian>& text_shdr);
1724
1725 // Return the output address of either a plain input section or a
1726 // relaxed input section. SHNDX is the section index.
1727 Arm_address
1728 simple_input_section_output_address(unsigned int, Output_section*);
1729
1730 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1731 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1732 Exidx_section_map;
1733
1734 // List of stub tables.
1735 Stub_table_list stub_tables_;
1736 // Bit vector to tell if a local symbol is a thumb function or not.
1737 // This is only valid after do_count_local_symbol is called.
1738 std::vector<bool> local_symbol_is_thumb_function_;
1739 // processor-specific flags in ELF file header.
1740 elfcpp::Elf_Word processor_specific_flags_;
1741 // Object attributes if there is an .ARM.attributes section or NULL.
1742 Attributes_section_data* attributes_section_data_;
1743 // Mapping symbols information.
1744 Mapping_symbols_info mapping_symbols_info_;
1745 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1746 std::vector<bool>* section_has_cortex_a8_workaround_;
1747 // Map a text section to its associated .ARM.exidx section, if there is one.
1748 Exidx_section_map exidx_section_map_;
1749 // Whether output local symbol count needs updating.
1750 bool output_local_symbol_count_needs_update_;
1751 // Whether we merge processor flags and attributes of this object to
1752 // output.
1753 bool merge_flags_and_attributes_;
1754 };
1755
1756 // Arm_dynobj class.
1757
1758 template<bool big_endian>
1759 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1760 {
1761 public:
1762 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1763 const elfcpp::Ehdr<32, big_endian>& ehdr)
1764 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1765 processor_specific_flags_(0), attributes_section_data_(NULL)
1766 { }
1767
1768 ~Arm_dynobj()
1769 { delete this->attributes_section_data_; }
1770
1771 // Downcast a base pointer to an Arm_relobj pointer. This is
1772 // not type-safe but we only use Arm_relobj not the base class.
1773 static Arm_dynobj<big_endian>*
1774 as_arm_dynobj(Dynobj* dynobj)
1775 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1776
1777 // Processor-specific flags in ELF file header. This is valid only after
1778 // reading symbols.
1779 elfcpp::Elf_Word
1780 processor_specific_flags() const
1781 { return this->processor_specific_flags_; }
1782
1783 // Attributes section data.
1784 const Attributes_section_data*
1785 attributes_section_data() const
1786 { return this->attributes_section_data_; }
1787
1788 protected:
1789 // Read the symbol information.
1790 void
1791 do_read_symbols(Read_symbols_data* sd);
1792
1793 private:
1794 // processor-specific flags in ELF file header.
1795 elfcpp::Elf_Word processor_specific_flags_;
1796 // Object attributes if there is an .ARM.attributes section or NULL.
1797 Attributes_section_data* attributes_section_data_;
1798 };
1799
1800 // Functor to read reloc addends during stub generation.
1801
1802 template<int sh_type, bool big_endian>
1803 struct Stub_addend_reader
1804 {
1805 // Return the addend for a relocation of a particular type. Depending
1806 // on whether this is a REL or RELA relocation, read the addend from a
1807 // view or from a Reloc object.
1808 elfcpp::Elf_types<32>::Elf_Swxword
1809 operator()(
1810 unsigned int /* r_type */,
1811 const unsigned char* /* view */,
1812 const typename Reloc_types<sh_type,
1813 32, big_endian>::Reloc& /* reloc */) const;
1814 };
1815
1816 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1817
1818 template<bool big_endian>
1819 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1820 {
1821 elfcpp::Elf_types<32>::Elf_Swxword
1822 operator()(
1823 unsigned int,
1824 const unsigned char*,
1825 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1826 };
1827
1828 // Specialized Stub_addend_reader for RELA type relocation sections.
1829 // We currently do not handle RELA type relocation sections but it is trivial
1830 // to implement the addend reader. This is provided for completeness and to
1831 // make it easier to add support for RELA relocation sections in the future.
1832
1833 template<bool big_endian>
1834 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1835 {
1836 elfcpp::Elf_types<32>::Elf_Swxword
1837 operator()(
1838 unsigned int,
1839 const unsigned char*,
1840 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1841 big_endian>::Reloc& reloc) const
1842 { return reloc.get_r_addend(); }
1843 };
1844
1845 // Cortex_a8_reloc class. We keep record of relocation that may need
1846 // the Cortex-A8 erratum workaround.
1847
1848 class Cortex_a8_reloc
1849 {
1850 public:
1851 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1852 Arm_address destination)
1853 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1854 { }
1855
1856 ~Cortex_a8_reloc()
1857 { }
1858
1859 // Accessors: This is a read-only class.
1860
1861 // Return the relocation stub associated with this relocation if there is
1862 // one.
1863 const Reloc_stub*
1864 reloc_stub() const
1865 { return this->reloc_stub_; }
1866
1867 // Return the relocation type.
1868 unsigned int
1869 r_type() const
1870 { return this->r_type_; }
1871
1872 // Return the destination address of the relocation. LSB stores the THUMB
1873 // bit.
1874 Arm_address
1875 destination() const
1876 { return this->destination_; }
1877
1878 private:
1879 // Associated relocation stub if there is one, or NULL.
1880 const Reloc_stub* reloc_stub_;
1881 // Relocation type.
1882 unsigned int r_type_;
1883 // Destination address of this relocation. LSB is used to distinguish
1884 // ARM/THUMB mode.
1885 Arm_address destination_;
1886 };
1887
1888 // Arm_output_data_got class. We derive this from Output_data_got to add
1889 // extra methods to handle TLS relocations in a static link.
1890
1891 template<bool big_endian>
1892 class Arm_output_data_got : public Output_data_got<32, big_endian>
1893 {
1894 public:
1895 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1896 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1897 { }
1898
1899 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1900 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1901 // applied in a static link.
1902 void
1903 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1904 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1905
1906 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1907 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1908 // relocation that needs to be applied in a static link.
1909 void
1910 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1911 Sized_relobj<32, big_endian>* relobj, unsigned int index)
1912 {
1913 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1914 index));
1915 }
1916
1917 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1918 // The first one is initialized to be 1, which is the module index for
1919 // the main executable and the second one 0. A reloc of the type
1920 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1921 // be applied by gold. GSYM is a global symbol.
1922 void
1923 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1924
1925 // Same as the above but for a local symbol in OBJECT with INDEX.
1926 void
1927 add_tls_gd32_with_static_reloc(unsigned int got_type,
1928 Sized_relobj<32, big_endian>* object,
1929 unsigned int index);
1930
1931 protected:
1932 // Write out the GOT table.
1933 void
1934 do_write(Output_file*);
1935
1936 private:
1937 // This class represent dynamic relocations that need to be applied by
1938 // gold because we are using TLS relocations in a static link.
1939 class Static_reloc
1940 {
1941 public:
1942 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1943 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1944 { this->u_.global.symbol = gsym; }
1945
1946 Static_reloc(unsigned int got_offset, unsigned int r_type,
1947 Sized_relobj<32, big_endian>* relobj, unsigned int index)
1948 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1949 {
1950 this->u_.local.relobj = relobj;
1951 this->u_.local.index = index;
1952 }
1953
1954 // Return the GOT offset.
1955 unsigned int
1956 got_offset() const
1957 { return this->got_offset_; }
1958
1959 // Relocation type.
1960 unsigned int
1961 r_type() const
1962 { return this->r_type_; }
1963
1964 // Whether the symbol is global or not.
1965 bool
1966 symbol_is_global() const
1967 { return this->symbol_is_global_; }
1968
1969 // For a relocation against a global symbol, the global symbol.
1970 Symbol*
1971 symbol() const
1972 {
1973 gold_assert(this->symbol_is_global_);
1974 return this->u_.global.symbol;
1975 }
1976
1977 // For a relocation against a local symbol, the defining object.
1978 Sized_relobj<32, big_endian>*
1979 relobj() const
1980 {
1981 gold_assert(!this->symbol_is_global_);
1982 return this->u_.local.relobj;
1983 }
1984
1985 // For a relocation against a local symbol, the local symbol index.
1986 unsigned int
1987 index() const
1988 {
1989 gold_assert(!this->symbol_is_global_);
1990 return this->u_.local.index;
1991 }
1992
1993 private:
1994 // GOT offset of the entry to which this relocation is applied.
1995 unsigned int got_offset_;
1996 // Type of relocation.
1997 unsigned int r_type_;
1998 // Whether this relocation is against a global symbol.
1999 bool symbol_is_global_;
2000 // A global or local symbol.
2001 union
2002 {
2003 struct
2004 {
2005 // For a global symbol, the symbol itself.
2006 Symbol* symbol;
2007 } global;
2008 struct
2009 {
2010 // For a local symbol, the object defining object.
2011 Sized_relobj<32, big_endian>* relobj;
2012 // For a local symbol, the symbol index.
2013 unsigned int index;
2014 } local;
2015 } u_;
2016 };
2017
2018 // Symbol table of the output object.
2019 Symbol_table* symbol_table_;
2020 // Layout of the output object.
2021 Layout* layout_;
2022 // Static relocs to be applied to the GOT.
2023 std::vector<Static_reloc> static_relocs_;
2024 };
2025
2026 // The ARM target has many relocation types with odd-sizes or incontigious
2027 // bits. The default handling of relocatable relocation cannot process these
2028 // relocations. So we have to extend the default code.
2029
2030 template<bool big_endian, int sh_type, typename Classify_reloc>
2031 class Arm_scan_relocatable_relocs :
2032 public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2033 {
2034 public:
2035 // Return the strategy to use for a local symbol which is a section
2036 // symbol, given the relocation type.
2037 inline Relocatable_relocs::Reloc_strategy
2038 local_section_strategy(unsigned int r_type, Relobj*)
2039 {
2040 if (sh_type == elfcpp::SHT_RELA)
2041 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2042 else
2043 {
2044 if (r_type == elfcpp::R_ARM_TARGET1
2045 || r_type == elfcpp::R_ARM_TARGET2)
2046 {
2047 const Target_arm<big_endian>* arm_target =
2048 Target_arm<big_endian>::default_target();
2049 r_type = arm_target->get_real_reloc_type(r_type);
2050 }
2051
2052 switch(r_type)
2053 {
2054 // Relocations that write nothing. These exclude R_ARM_TARGET1
2055 // and R_ARM_TARGET2.
2056 case elfcpp::R_ARM_NONE:
2057 case elfcpp::R_ARM_V4BX:
2058 case elfcpp::R_ARM_TLS_GOTDESC:
2059 case elfcpp::R_ARM_TLS_CALL:
2060 case elfcpp::R_ARM_TLS_DESCSEQ:
2061 case elfcpp::R_ARM_THM_TLS_CALL:
2062 case elfcpp::R_ARM_GOTRELAX:
2063 case elfcpp::R_ARM_GNU_VTENTRY:
2064 case elfcpp::R_ARM_GNU_VTINHERIT:
2065 case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2066 case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2067 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2068 // These should have been converted to something else above.
2069 case elfcpp::R_ARM_TARGET1:
2070 case elfcpp::R_ARM_TARGET2:
2071 gold_unreachable();
2072 // Relocations that write full 32 bits.
2073 case elfcpp::R_ARM_ABS32:
2074 case elfcpp::R_ARM_REL32:
2075 case elfcpp::R_ARM_SBREL32:
2076 case elfcpp::R_ARM_GOTOFF32:
2077 case elfcpp::R_ARM_BASE_PREL:
2078 case elfcpp::R_ARM_GOT_BREL:
2079 case elfcpp::R_ARM_BASE_ABS:
2080 case elfcpp::R_ARM_ABS32_NOI:
2081 case elfcpp::R_ARM_REL32_NOI:
2082 case elfcpp::R_ARM_PLT32_ABS:
2083 case elfcpp::R_ARM_GOT_ABS:
2084 case elfcpp::R_ARM_GOT_PREL:
2085 case elfcpp::R_ARM_TLS_GD32:
2086 case elfcpp::R_ARM_TLS_LDM32:
2087 case elfcpp::R_ARM_TLS_LDO32:
2088 case elfcpp::R_ARM_TLS_IE32:
2089 case elfcpp::R_ARM_TLS_LE32:
2090 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4;
2091 default:
2092 // For all other static relocations, return RELOC_SPECIAL.
2093 return Relocatable_relocs::RELOC_SPECIAL;
2094 }
2095 }
2096 }
2097 };
2098
2099 // Utilities for manipulating integers of up to 32-bits
2100
2101 namespace utils
2102 {
2103 // Sign extend an n-bit unsigned integer stored in an uint32_t into
2104 // an int32_t. NO_BITS must be between 1 to 32.
2105 template<int no_bits>
2106 static inline int32_t
2107 sign_extend(uint32_t bits)
2108 {
2109 gold_assert(no_bits >= 0 && no_bits <= 32);
2110 if (no_bits == 32)
2111 return static_cast<int32_t>(bits);
2112 uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
2113 bits &= mask;
2114 uint32_t top_bit = 1U << (no_bits - 1);
2115 int32_t as_signed = static_cast<int32_t>(bits);
2116 return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
2117 }
2118
2119 // Detects overflow of an NO_BITS integer stored in a uint32_t.
2120 template<int no_bits>
2121 static inline bool
2122 has_overflow(uint32_t bits)
2123 {
2124 gold_assert(no_bits >= 0 && no_bits <= 32);
2125 if (no_bits == 32)
2126 return false;
2127 int32_t max = (1 << (no_bits - 1)) - 1;
2128 int32_t min = -(1 << (no_bits - 1));
2129 int32_t as_signed = static_cast<int32_t>(bits);
2130 return as_signed > max || as_signed < min;
2131 }
2132
2133 // Detects overflow of an NO_BITS integer stored in a uint32_t when it
2134 // fits in the given number of bits as either a signed or unsigned value.
2135 // For example, has_signed_unsigned_overflow<8> would check
2136 // -128 <= bits <= 255
2137 template<int no_bits>
2138 static inline bool
2139 has_signed_unsigned_overflow(uint32_t bits)
2140 {
2141 gold_assert(no_bits >= 2 && no_bits <= 32);
2142 if (no_bits == 32)
2143 return false;
2144 int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
2145 int32_t min = -(1 << (no_bits - 1));
2146 int32_t as_signed = static_cast<int32_t>(bits);
2147 return as_signed > max || as_signed < min;
2148 }
2149
2150 // Select bits from A and B using bits in MASK. For each n in [0..31],
2151 // the n-th bit in the result is chosen from the n-th bits of A and B.
2152 // A zero selects A and a one selects B.
2153 static inline uint32_t
2154 bit_select(uint32_t a, uint32_t b, uint32_t mask)
2155 { return (a & ~mask) | (b & mask); }
2156 };
2157
2158 template<bool big_endian>
2159 class Target_arm : public Sized_target<32, big_endian>
2160 {
2161 public:
2162 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2163 Reloc_section;
2164
2165 // When were are relocating a stub, we pass this as the relocation number.
2166 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2167
2168 Target_arm()
2169 : Sized_target<32, big_endian>(&arm_info),
2170 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2171 copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
2172 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2173 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2174 may_use_blx_(false), should_force_pic_veneer_(false),
2175 arm_input_section_map_(), attributes_section_data_(NULL),
2176 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2177 { }
2178
2179 // Virtual function which is set to return true by a target if
2180 // it can use relocation types to determine if a function's
2181 // pointer is taken.
2182 virtual bool
2183 can_check_for_function_pointers() const
2184 { return true; }
2185
2186 // Whether a section called SECTION_NAME may have function pointers to
2187 // sections not eligible for safe ICF folding.
2188 virtual bool
2189 section_may_have_icf_unsafe_pointers(const char* section_name) const
2190 {
2191 return (!is_prefix_of(".ARM.exidx", section_name)
2192 && !is_prefix_of(".ARM.extab", section_name)
2193 && Target::section_may_have_icf_unsafe_pointers(section_name));
2194 }
2195
2196 // Whether we can use BLX.
2197 bool
2198 may_use_blx() const
2199 { return this->may_use_blx_; }
2200
2201 // Set use-BLX flag.
2202 void
2203 set_may_use_blx(bool value)
2204 { this->may_use_blx_ = value; }
2205
2206 // Whether we force PCI branch veneers.
2207 bool
2208 should_force_pic_veneer() const
2209 { return this->should_force_pic_veneer_; }
2210
2211 // Set PIC veneer flag.
2212 void
2213 set_should_force_pic_veneer(bool value)
2214 { this->should_force_pic_veneer_ = value; }
2215
2216 // Whether we use THUMB-2 instructions.
2217 bool
2218 using_thumb2() const
2219 {
2220 Object_attribute* attr =
2221 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2222 int arch = attr->int_value();
2223 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2224 }
2225
2226 // Whether we use THUMB/THUMB-2 instructions only.
2227 bool
2228 using_thumb_only() const
2229 {
2230 Object_attribute* attr =
2231 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2232
2233 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2234 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2235 return true;
2236 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2237 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2238 return false;
2239 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2240 return attr->int_value() == 'M';
2241 }
2242
2243 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2244 bool
2245 may_use_arm_nop() const
2246 {
2247 Object_attribute* attr =
2248 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2249 int arch = attr->int_value();
2250 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2251 || arch == elfcpp::TAG_CPU_ARCH_V6K
2252 || arch == elfcpp::TAG_CPU_ARCH_V7
2253 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2254 }
2255
2256 // Whether we have THUMB-2 NOP.W instruction.
2257 bool
2258 may_use_thumb2_nop() const
2259 {
2260 Object_attribute* attr =
2261 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2262 int arch = attr->int_value();
2263 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2264 || arch == elfcpp::TAG_CPU_ARCH_V7
2265 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2266 }
2267
2268 // Process the relocations to determine unreferenced sections for
2269 // garbage collection.
2270 void
2271 gc_process_relocs(Symbol_table* symtab,
2272 Layout* layout,
2273 Sized_relobj<32, big_endian>* object,
2274 unsigned int data_shndx,
2275 unsigned int sh_type,
2276 const unsigned char* prelocs,
2277 size_t reloc_count,
2278 Output_section* output_section,
2279 bool needs_special_offset_handling,
2280 size_t local_symbol_count,
2281 const unsigned char* plocal_symbols);
2282
2283 // Scan the relocations to look for symbol adjustments.
2284 void
2285 scan_relocs(Symbol_table* symtab,
2286 Layout* layout,
2287 Sized_relobj<32, big_endian>* object,
2288 unsigned int data_shndx,
2289 unsigned int sh_type,
2290 const unsigned char* prelocs,
2291 size_t reloc_count,
2292 Output_section* output_section,
2293 bool needs_special_offset_handling,
2294 size_t local_symbol_count,
2295 const unsigned char* plocal_symbols);
2296
2297 // Finalize the sections.
2298 void
2299 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2300
2301 // Return the value to use for a dynamic symbol which requires special
2302 // treatment.
2303 uint64_t
2304 do_dynsym_value(const Symbol*) const;
2305
2306 // Relocate a section.
2307 void
2308 relocate_section(const Relocate_info<32, big_endian>*,
2309 unsigned int sh_type,
2310 const unsigned char* prelocs,
2311 size_t reloc_count,
2312 Output_section* output_section,
2313 bool needs_special_offset_handling,
2314 unsigned char* view,
2315 Arm_address view_address,
2316 section_size_type view_size,
2317 const Reloc_symbol_changes*);
2318
2319 // Scan the relocs during a relocatable link.
2320 void
2321 scan_relocatable_relocs(Symbol_table* symtab,
2322 Layout* layout,
2323 Sized_relobj<32, big_endian>* object,
2324 unsigned int data_shndx,
2325 unsigned int sh_type,
2326 const unsigned char* prelocs,
2327 size_t reloc_count,
2328 Output_section* output_section,
2329 bool needs_special_offset_handling,
2330 size_t local_symbol_count,
2331 const unsigned char* plocal_symbols,
2332 Relocatable_relocs*);
2333
2334 // Relocate a section during a relocatable link.
2335 void
2336 relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2337 unsigned int sh_type,
2338 const unsigned char* prelocs,
2339 size_t reloc_count,
2340 Output_section* output_section,
2341 off_t offset_in_output_section,
2342 const Relocatable_relocs*,
2343 unsigned char* view,
2344 Arm_address view_address,
2345 section_size_type view_size,
2346 unsigned char* reloc_view,
2347 section_size_type reloc_view_size);
2348
2349 // Perform target-specific processing in a relocatable link. This is
2350 // only used if we use the relocation strategy RELOC_SPECIAL.
2351 void
2352 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2353 unsigned int sh_type,
2354 const unsigned char* preloc_in,
2355 size_t relnum,
2356 Output_section* output_section,
2357 off_t offset_in_output_section,
2358 unsigned char* view,
2359 typename elfcpp::Elf_types<32>::Elf_Addr
2360 view_address,
2361 section_size_type view_size,
2362 unsigned char* preloc_out);
2363
2364 // Return whether SYM is defined by the ABI.
2365 bool
2366 do_is_defined_by_abi(Symbol* sym) const
2367 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2368
2369 // Return whether there is a GOT section.
2370 bool
2371 has_got_section() const
2372 { return this->got_ != NULL; }
2373
2374 // Return the size of the GOT section.
2375 section_size_type
2376 got_size() const
2377 {
2378 gold_assert(this->got_ != NULL);
2379 return this->got_->data_size();
2380 }
2381
2382 // Return the number of entries in the GOT.
2383 unsigned int
2384 got_entry_count() const
2385 {
2386 if (!this->has_got_section())
2387 return 0;
2388 return this->got_size() / 4;
2389 }
2390
2391 // Return the number of entries in the PLT.
2392 unsigned int
2393 plt_entry_count() const;
2394
2395 // Return the offset of the first non-reserved PLT entry.
2396 unsigned int
2397 first_plt_entry_offset() const;
2398
2399 // Return the size of each PLT entry.
2400 unsigned int
2401 plt_entry_size() const;
2402
2403 // Map platform-specific reloc types
2404 static unsigned int
2405 get_real_reloc_type(unsigned int r_type);
2406
2407 //
2408 // Methods to support stub-generations.
2409 //
2410
2411 // Return the stub factory
2412 const Stub_factory&
2413 stub_factory() const
2414 { return this->stub_factory_; }
2415
2416 // Make a new Arm_input_section object.
2417 Arm_input_section<big_endian>*
2418 new_arm_input_section(Relobj*, unsigned int);
2419
2420 // Find the Arm_input_section object corresponding to the SHNDX-th input
2421 // section of RELOBJ.
2422 Arm_input_section<big_endian>*
2423 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2424
2425 // Make a new Stub_table
2426 Stub_table<big_endian>*
2427 new_stub_table(Arm_input_section<big_endian>*);
2428
2429 // Scan a section for stub generation.
2430 void
2431 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2432 const unsigned char*, size_t, Output_section*,
2433 bool, const unsigned char*, Arm_address,
2434 section_size_type);
2435
2436 // Relocate a stub.
2437 void
2438 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2439 Output_section*, unsigned char*, Arm_address,
2440 section_size_type);
2441
2442 // Get the default ARM target.
2443 static Target_arm<big_endian>*
2444 default_target()
2445 {
2446 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2447 && parameters->target().is_big_endian() == big_endian);
2448 return static_cast<Target_arm<big_endian>*>(
2449 parameters->sized_target<32, big_endian>());
2450 }
2451
2452 // Whether NAME belongs to a mapping symbol.
2453 static bool
2454 is_mapping_symbol_name(const char* name)
2455 {
2456 return (name
2457 && name[0] == '$'
2458 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2459 && (name[2] == '\0' || name[2] == '.'));
2460 }
2461
2462 // Whether we work around the Cortex-A8 erratum.
2463 bool
2464 fix_cortex_a8() const
2465 { return this->fix_cortex_a8_; }
2466
2467 // Whether we merge exidx entries in debuginfo.
2468 bool
2469 merge_exidx_entries() const
2470 { return parameters->options().merge_exidx_entries(); }
2471
2472 // Whether we fix R_ARM_V4BX relocation.
2473 // 0 - do not fix
2474 // 1 - replace with MOV instruction (armv4 target)
2475 // 2 - make interworking veneer (>= armv4t targets only)
2476 General_options::Fix_v4bx
2477 fix_v4bx() const
2478 { return parameters->options().fix_v4bx(); }
2479
2480 // Scan a span of THUMB code section for Cortex-A8 erratum.
2481 void
2482 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2483 section_size_type, section_size_type,
2484 const unsigned char*, Arm_address);
2485
2486 // Apply Cortex-A8 workaround to a branch.
2487 void
2488 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2489 unsigned char*, Arm_address);
2490
2491 protected:
2492 // Make an ELF object.
2493 Object*
2494 do_make_elf_object(const std::string&, Input_file*, off_t,
2495 const elfcpp::Ehdr<32, big_endian>& ehdr);
2496
2497 Object*
2498 do_make_elf_object(const std::string&, Input_file*, off_t,
2499 const elfcpp::Ehdr<32, !big_endian>&)
2500 { gold_unreachable(); }
2501
2502 Object*
2503 do_make_elf_object(const std::string&, Input_file*, off_t,
2504 const elfcpp::Ehdr<64, false>&)
2505 { gold_unreachable(); }
2506
2507 Object*
2508 do_make_elf_object(const std::string&, Input_file*, off_t,
2509 const elfcpp::Ehdr<64, true>&)
2510 { gold_unreachable(); }
2511
2512 // Make an output section.
2513 Output_section*
2514 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2515 elfcpp::Elf_Xword flags)
2516 { return new Arm_output_section<big_endian>(name, type, flags); }
2517
2518 void
2519 do_adjust_elf_header(unsigned char* view, int len) const;
2520
2521 // We only need to generate stubs, and hence perform relaxation if we are
2522 // not doing relocatable linking.
2523 bool
2524 do_may_relax() const
2525 { return !parameters->options().relocatable(); }
2526
2527 bool
2528 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2529
2530 // Determine whether an object attribute tag takes an integer, a
2531 // string or both.
2532 int
2533 do_attribute_arg_type(int tag) const;
2534
2535 // Reorder tags during output.
2536 int
2537 do_attributes_order(int num) const;
2538
2539 // This is called when the target is selected as the default.
2540 void
2541 do_select_as_default_target()
2542 {
2543 // No locking is required since there should only be one default target.
2544 // We cannot have both the big-endian and little-endian ARM targets
2545 // as the default.
2546 gold_assert(arm_reloc_property_table == NULL);
2547 arm_reloc_property_table = new Arm_reloc_property_table();
2548 }
2549
2550 private:
2551 // The class which scans relocations.
2552 class Scan
2553 {
2554 public:
2555 Scan()
2556 : issued_non_pic_error_(false)
2557 { }
2558
2559 inline void
2560 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2561 Sized_relobj<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 const elfcpp::Sym<32, big_endian>& lsym);
2566
2567 inline void
2568 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2569 Sized_relobj<32, big_endian>* object,
2570 unsigned int data_shndx,
2571 Output_section* output_section,
2572 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2573 Symbol* gsym);
2574
2575 inline bool
2576 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2577 Sized_relobj<32, big_endian>* ,
2578 unsigned int ,
2579 Output_section* ,
2580 const elfcpp::Rel<32, big_endian>& ,
2581 unsigned int ,
2582 const elfcpp::Sym<32, big_endian>&);
2583
2584 inline bool
2585 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2586 Sized_relobj<32, big_endian>* ,
2587 unsigned int ,
2588 Output_section* ,
2589 const elfcpp::Rel<32, big_endian>& ,
2590 unsigned int , Symbol*);
2591
2592 private:
2593 static void
2594 unsupported_reloc_local(Sized_relobj<32, big_endian>*,
2595 unsigned int r_type);
2596
2597 static void
2598 unsupported_reloc_global(Sized_relobj<32, big_endian>*,
2599 unsigned int r_type, Symbol*);
2600
2601 void
2602 check_non_pic(Relobj*, unsigned int r_type);
2603
2604 // Almost identical to Symbol::needs_plt_entry except that it also
2605 // handles STT_ARM_TFUNC.
2606 static bool
2607 symbol_needs_plt_entry(const Symbol* sym)
2608 {
2609 // An undefined symbol from an executable does not need a PLT entry.
2610 if (sym->is_undefined() && !parameters->options().shared())
2611 return false;
2612
2613 return (!parameters->doing_static_link()
2614 && (sym->type() == elfcpp::STT_FUNC
2615 || sym->type() == elfcpp::STT_ARM_TFUNC)
2616 && (sym->is_from_dynobj()
2617 || sym->is_undefined()
2618 || sym->is_preemptible()));
2619 }
2620
2621 inline bool
2622 possible_function_pointer_reloc(unsigned int r_type);
2623
2624 // Whether we have issued an error about a non-PIC compilation.
2625 bool issued_non_pic_error_;
2626 };
2627
2628 // The class which implements relocation.
2629 class Relocate
2630 {
2631 public:
2632 Relocate()
2633 { }
2634
2635 ~Relocate()
2636 { }
2637
2638 // Return whether the static relocation needs to be applied.
2639 inline bool
2640 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2641 int ref_flags,
2642 bool is_32bit,
2643 Output_section* output_section);
2644
2645 // Do a relocation. Return false if the caller should not issue
2646 // any warnings about this relocation.
2647 inline bool
2648 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2649 Output_section*, size_t relnum,
2650 const elfcpp::Rel<32, big_endian>&,
2651 unsigned int r_type, const Sized_symbol<32>*,
2652 const Symbol_value<32>*,
2653 unsigned char*, Arm_address,
2654 section_size_type);
2655
2656 // Return whether we want to pass flag NON_PIC_REF for this
2657 // reloc. This means the relocation type accesses a symbol not via
2658 // GOT or PLT.
2659 static inline bool
2660 reloc_is_non_pic(unsigned int r_type)
2661 {
2662 switch (r_type)
2663 {
2664 // These relocation types reference GOT or PLT entries explicitly.
2665 case elfcpp::R_ARM_GOT_BREL:
2666 case elfcpp::R_ARM_GOT_ABS:
2667 case elfcpp::R_ARM_GOT_PREL:
2668 case elfcpp::R_ARM_GOT_BREL12:
2669 case elfcpp::R_ARM_PLT32_ABS:
2670 case elfcpp::R_ARM_TLS_GD32:
2671 case elfcpp::R_ARM_TLS_LDM32:
2672 case elfcpp::R_ARM_TLS_IE32:
2673 case elfcpp::R_ARM_TLS_IE12GP:
2674
2675 // These relocate types may use PLT entries.
2676 case elfcpp::R_ARM_CALL:
2677 case elfcpp::R_ARM_THM_CALL:
2678 case elfcpp::R_ARM_JUMP24:
2679 case elfcpp::R_ARM_THM_JUMP24:
2680 case elfcpp::R_ARM_THM_JUMP19:
2681 case elfcpp::R_ARM_PLT32:
2682 case elfcpp::R_ARM_THM_XPC22:
2683 case elfcpp::R_ARM_PREL31:
2684 case elfcpp::R_ARM_SBREL31:
2685 return false;
2686
2687 default:
2688 return true;
2689 }
2690 }
2691
2692 private:
2693 // Do a TLS relocation.
2694 inline typename Arm_relocate_functions<big_endian>::Status
2695 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2696 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2697 const Sized_symbol<32>*, const Symbol_value<32>*,
2698 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2699 section_size_type);
2700
2701 };
2702
2703 // A class which returns the size required for a relocation type,
2704 // used while scanning relocs during a relocatable link.
2705 class Relocatable_size_for_reloc
2706 {
2707 public:
2708 unsigned int
2709 get_size_for_reloc(unsigned int, Relobj*);
2710 };
2711
2712 // Adjust TLS relocation type based on the options and whether this
2713 // is a local symbol.
2714 static tls::Tls_optimization
2715 optimize_tls_reloc(bool is_final, int r_type);
2716
2717 // Get the GOT section, creating it if necessary.
2718 Arm_output_data_got<big_endian>*
2719 got_section(Symbol_table*, Layout*);
2720
2721 // Get the GOT PLT section.
2722 Output_data_space*
2723 got_plt_section() const
2724 {
2725 gold_assert(this->got_plt_ != NULL);
2726 return this->got_plt_;
2727 }
2728
2729 // Create a PLT entry for a global symbol.
2730 void
2731 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2732
2733 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2734 void
2735 define_tls_base_symbol(Symbol_table*, Layout*);
2736
2737 // Create a GOT entry for the TLS module index.
2738 unsigned int
2739 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2740 Sized_relobj<32, big_endian>* object);
2741
2742 // Get the PLT section.
2743 const Output_data_plt_arm<big_endian>*
2744 plt_section() const
2745 {
2746 gold_assert(this->plt_ != NULL);
2747 return this->plt_;
2748 }
2749
2750 // Get the dynamic reloc section, creating it if necessary.
2751 Reloc_section*
2752 rel_dyn_section(Layout*);
2753
2754 // Get the section to use for TLS_DESC relocations.
2755 Reloc_section*
2756 rel_tls_desc_section(Layout*) const;
2757
2758 // Return true if the symbol may need a COPY relocation.
2759 // References from an executable object to non-function symbols
2760 // defined in a dynamic object may need a COPY relocation.
2761 bool
2762 may_need_copy_reloc(Symbol* gsym)
2763 {
2764 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2765 && gsym->may_need_copy_reloc());
2766 }
2767
2768 // Add a potential copy relocation.
2769 void
2770 copy_reloc(Symbol_table* symtab, Layout* layout,
2771 Sized_relobj<32, big_endian>* object,
2772 unsigned int shndx, Output_section* output_section,
2773 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2774 {
2775 this->copy_relocs_.copy_reloc(symtab, layout,
2776 symtab->get_sized_symbol<32>(sym),
2777 object, shndx, output_section, reloc,
2778 this->rel_dyn_section(layout));
2779 }
2780
2781 // Whether two EABI versions are compatible.
2782 static bool
2783 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2784
2785 // Merge processor-specific flags from input object and those in the ELF
2786 // header of the output.
2787 void
2788 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2789
2790 // Get the secondary compatible architecture.
2791 static int
2792 get_secondary_compatible_arch(const Attributes_section_data*);
2793
2794 // Set the secondary compatible architecture.
2795 static void
2796 set_secondary_compatible_arch(Attributes_section_data*, int);
2797
2798 static int
2799 tag_cpu_arch_combine(const char*, int, int*, int, int);
2800
2801 // Helper to print AEABI enum tag value.
2802 static std::string
2803 aeabi_enum_name(unsigned int);
2804
2805 // Return string value for TAG_CPU_name.
2806 static std::string
2807 tag_cpu_name_value(unsigned int);
2808
2809 // Merge object attributes from input object and those in the output.
2810 void
2811 merge_object_attributes(const char*, const Attributes_section_data*);
2812
2813 // Helper to get an AEABI object attribute
2814 Object_attribute*
2815 get_aeabi_object_attribute(int tag) const
2816 {
2817 Attributes_section_data* pasd = this->attributes_section_data_;
2818 gold_assert(pasd != NULL);
2819 Object_attribute* attr =
2820 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2821 gold_assert(attr != NULL);
2822 return attr;
2823 }
2824
2825 //
2826 // Methods to support stub-generations.
2827 //
2828
2829 // Group input sections for stub generation.
2830 void
2831 group_sections(Layout*, section_size_type, bool, const Task*);
2832
2833 // Scan a relocation for stub generation.
2834 void
2835 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2836 const Sized_symbol<32>*, unsigned int,
2837 const Symbol_value<32>*,
2838 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2839
2840 // Scan a relocation section for stub.
2841 template<int sh_type>
2842 void
2843 scan_reloc_section_for_stubs(
2844 const Relocate_info<32, big_endian>* relinfo,
2845 const unsigned char* prelocs,
2846 size_t reloc_count,
2847 Output_section* output_section,
2848 bool needs_special_offset_handling,
2849 const unsigned char* view,
2850 elfcpp::Elf_types<32>::Elf_Addr view_address,
2851 section_size_type);
2852
2853 // Fix .ARM.exidx section coverage.
2854 void
2855 fix_exidx_coverage(Layout*, const Input_objects*,
2856 Arm_output_section<big_endian>*, Symbol_table*,
2857 const Task*);
2858
2859 // Functors for STL set.
2860 struct output_section_address_less_than
2861 {
2862 bool
2863 operator()(const Output_section* s1, const Output_section* s2) const
2864 { return s1->address() < s2->address(); }
2865 };
2866
2867 // Information about this specific target which we pass to the
2868 // general Target structure.
2869 static const Target::Target_info arm_info;
2870
2871 // The types of GOT entries needed for this platform.
2872 // These values are exposed to the ABI in an incremental link.
2873 // Do not renumber existing values without changing the version
2874 // number of the .gnu_incremental_inputs section.
2875 enum Got_type
2876 {
2877 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2878 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2879 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2880 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2881 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2882 };
2883
2884 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2885
2886 // Map input section to Arm_input_section.
2887 typedef Unordered_map<Section_id,
2888 Arm_input_section<big_endian>*,
2889 Section_id_hash>
2890 Arm_input_section_map;
2891
2892 // Map output addresses to relocs for Cortex-A8 erratum.
2893 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2894 Cortex_a8_relocs_info;
2895
2896 // The GOT section.
2897 Arm_output_data_got<big_endian>* got_;
2898 // The PLT section.
2899 Output_data_plt_arm<big_endian>* plt_;
2900 // The GOT PLT section.
2901 Output_data_space* got_plt_;
2902 // The dynamic reloc section.
2903 Reloc_section* rel_dyn_;
2904 // Relocs saved to avoid a COPY reloc.
2905 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2906 // Space for variables copied with a COPY reloc.
2907 Output_data_space* dynbss_;
2908 // Offset of the GOT entry for the TLS module index.
2909 unsigned int got_mod_index_offset_;
2910 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2911 bool tls_base_symbol_defined_;
2912 // Vector of Stub_tables created.
2913 Stub_table_list stub_tables_;
2914 // Stub factory.
2915 const Stub_factory &stub_factory_;
2916 // Whether we can use BLX.
2917 bool may_use_blx_;
2918 // Whether we force PIC branch veneers.
2919 bool should_force_pic_veneer_;
2920 // Map for locating Arm_input_sections.
2921 Arm_input_section_map arm_input_section_map_;
2922 // Attributes section data in output.
2923 Attributes_section_data* attributes_section_data_;
2924 // Whether we want to fix code for Cortex-A8 erratum.
2925 bool fix_cortex_a8_;
2926 // Map addresses to relocs for Cortex-A8 erratum.
2927 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2928 };
2929
2930 template<bool big_endian>
2931 const Target::Target_info Target_arm<big_endian>::arm_info =
2932 {
2933 32, // size
2934 big_endian, // is_big_endian
2935 elfcpp::EM_ARM, // machine_code
2936 false, // has_make_symbol
2937 false, // has_resolve
2938 false, // has_code_fill
2939 true, // is_default_stack_executable
2940 '\0', // wrap_char
2941 "/usr/lib/libc.so.1", // dynamic_linker
2942 0x8000, // default_text_segment_address
2943 0x1000, // abi_pagesize (overridable by -z max-page-size)
2944 0x1000, // common_pagesize (overridable by -z common-page-size)
2945 elfcpp::SHN_UNDEF, // small_common_shndx
2946 elfcpp::SHN_UNDEF, // large_common_shndx
2947 0, // small_common_section_flags
2948 0, // large_common_section_flags
2949 ".ARM.attributes", // attributes_section
2950 "aeabi" // attributes_vendor
2951 };
2952
2953 // Arm relocate functions class
2954 //
2955
2956 template<bool big_endian>
2957 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2958 {
2959 public:
2960 typedef enum
2961 {
2962 STATUS_OKAY, // No error during relocation.
2963 STATUS_OVERFLOW, // Relocation oveflow.
2964 STATUS_BAD_RELOC // Relocation cannot be applied.
2965 } Status;
2966
2967 private:
2968 typedef Relocate_functions<32, big_endian> Base;
2969 typedef Arm_relocate_functions<big_endian> This;
2970
2971 // Encoding of imm16 argument for movt and movw ARM instructions
2972 // from ARM ARM:
2973 //
2974 // imm16 := imm4 | imm12
2975 //
2976 // 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
2977 // +-------+---------------+-------+-------+-----------------------+
2978 // | | |imm4 | |imm12 |
2979 // +-------+---------------+-------+-------+-----------------------+
2980
2981 // Extract the relocation addend from VAL based on the ARM
2982 // instruction encoding described above.
2983 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2984 extract_arm_movw_movt_addend(
2985 typename elfcpp::Swap<32, big_endian>::Valtype val)
2986 {
2987 // According to the Elf ABI for ARM Architecture the immediate
2988 // field is sign-extended to form the addend.
2989 return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
2990 }
2991
2992 // Insert X into VAL based on the ARM instruction encoding described
2993 // above.
2994 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2995 insert_val_arm_movw_movt(
2996 typename elfcpp::Swap<32, big_endian>::Valtype val,
2997 typename elfcpp::Swap<32, big_endian>::Valtype x)
2998 {
2999 val &= 0xfff0f000;
3000 val |= x & 0x0fff;
3001 val |= (x & 0xf000) << 4;
3002 return val;
3003 }
3004
3005 // Encoding of imm16 argument for movt and movw Thumb2 instructions
3006 // from ARM ARM:
3007 //
3008 // imm16 := imm4 | i | imm3 | imm8
3009 //
3010 // 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
3011 // +---------+-+-----------+-------++-+-----+-------+---------------+
3012 // | |i| |imm4 || |imm3 | |imm8 |
3013 // +---------+-+-----------+-------++-+-----+-------+---------------+
3014
3015 // Extract the relocation addend from VAL based on the Thumb2
3016 // instruction encoding described above.
3017 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3018 extract_thumb_movw_movt_addend(
3019 typename elfcpp::Swap<32, big_endian>::Valtype val)
3020 {
3021 // According to the Elf ABI for ARM Architecture the immediate
3022 // field is sign-extended to form the addend.
3023 return utils::sign_extend<16>(((val >> 4) & 0xf000)
3024 | ((val >> 15) & 0x0800)
3025 | ((val >> 4) & 0x0700)
3026 | (val & 0x00ff));
3027 }
3028
3029 // Insert X into VAL based on the Thumb2 instruction encoding
3030 // described above.
3031 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3032 insert_val_thumb_movw_movt(
3033 typename elfcpp::Swap<32, big_endian>::Valtype val,
3034 typename elfcpp::Swap<32, big_endian>::Valtype x)
3035 {
3036 val &= 0xfbf08f00;
3037 val |= (x & 0xf000) << 4;
3038 val |= (x & 0x0800) << 15;
3039 val |= (x & 0x0700) << 4;
3040 val |= (x & 0x00ff);
3041 return val;
3042 }
3043
3044 // Calculate the smallest constant Kn for the specified residual.
3045 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3046 static uint32_t
3047 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3048 {
3049 int32_t msb;
3050
3051 if (residual == 0)
3052 return 0;
3053 // Determine the most significant bit in the residual and
3054 // align the resulting value to a 2-bit boundary.
3055 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3056 ;
3057 // The desired shift is now (msb - 6), or zero, whichever
3058 // is the greater.
3059 return (((msb - 6) < 0) ? 0 : (msb - 6));
3060 }
3061
3062 // Calculate the final residual for the specified group index.
3063 // If the passed group index is less than zero, the method will return
3064 // the value of the specified residual without any change.
3065 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3066 static typename elfcpp::Swap<32, big_endian>::Valtype
3067 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3068 const int group)
3069 {
3070 for (int n = 0; n <= group; n++)
3071 {
3072 // Calculate which part of the value to mask.
3073 uint32_t shift = calc_grp_kn(residual);
3074 // Calculate the residual for the next time around.
3075 residual &= ~(residual & (0xff << shift));
3076 }
3077
3078 return residual;
3079 }
3080
3081 // Calculate the value of Gn for the specified group index.
3082 // We return it in the form of an encoded constant-and-rotation.
3083 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3084 static typename elfcpp::Swap<32, big_endian>::Valtype
3085 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3086 const int group)
3087 {
3088 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3089 uint32_t shift = 0;
3090
3091 for (int n = 0; n <= group; n++)
3092 {
3093 // Calculate which part of the value to mask.
3094 shift = calc_grp_kn(residual);
3095 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3096 gn = residual & (0xff << shift);
3097 // Calculate the residual for the next time around.
3098 residual &= ~gn;
3099 }
3100 // Return Gn in the form of an encoded constant-and-rotation.
3101 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3102 }
3103
3104 public:
3105 // Handle ARM long branches.
3106 static typename This::Status
3107 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3108 unsigned char*, const Sized_symbol<32>*,
3109 const Arm_relobj<big_endian>*, unsigned int,
3110 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3111
3112 // Handle THUMB long branches.
3113 static typename This::Status
3114 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3115 unsigned char*, const Sized_symbol<32>*,
3116 const Arm_relobj<big_endian>*, unsigned int,
3117 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3118
3119
3120 // Return the branch offset of a 32-bit THUMB branch.
3121 static inline int32_t
3122 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3123 {
3124 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3125 // involving the J1 and J2 bits.
3126 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3127 uint32_t upper = upper_insn & 0x3ffU;
3128 uint32_t lower = lower_insn & 0x7ffU;
3129 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3130 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3131 uint32_t i1 = j1 ^ s ? 0 : 1;
3132 uint32_t i2 = j2 ^ s ? 0 : 1;
3133
3134 return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
3135 | (upper << 12) | (lower << 1));
3136 }
3137
3138 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3139 // UPPER_INSN is the original upper instruction of the branch. Caller is
3140 // responsible for overflow checking and BLX offset adjustment.
3141 static inline uint16_t
3142 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3143 {
3144 uint32_t s = offset < 0 ? 1 : 0;
3145 uint32_t bits = static_cast<uint32_t>(offset);
3146 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3147 }
3148
3149 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3150 // LOWER_INSN is the original lower instruction of the branch. Caller is
3151 // responsible for overflow checking and BLX offset adjustment.
3152 static inline uint16_t
3153 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3154 {
3155 uint32_t s = offset < 0 ? 1 : 0;
3156 uint32_t bits = static_cast<uint32_t>(offset);
3157 return ((lower_insn & ~0x2fffU)
3158 | ((((bits >> 23) & 1) ^ !s) << 13)
3159 | ((((bits >> 22) & 1) ^ !s) << 11)
3160 | ((bits >> 1) & 0x7ffU));
3161 }
3162
3163 // Return the branch offset of a 32-bit THUMB conditional branch.
3164 static inline int32_t
3165 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3166 {
3167 uint32_t s = (upper_insn & 0x0400U) >> 10;
3168 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3169 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3170 uint32_t lower = (lower_insn & 0x07ffU);
3171 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3172
3173 return utils::sign_extend<21>((upper << 12) | (lower << 1));
3174 }
3175
3176 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3177 // instruction. UPPER_INSN is the original upper instruction of the branch.
3178 // Caller is responsible for overflow checking.
3179 static inline uint16_t
3180 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3181 {
3182 uint32_t s = offset < 0 ? 1 : 0;
3183 uint32_t bits = static_cast<uint32_t>(offset);
3184 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3185 }
3186
3187 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3188 // instruction. LOWER_INSN is the original lower instruction of the branch.
3189 // Caller is reponsible for overflow checking.
3190 static inline uint16_t
3191 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3192 {
3193 uint32_t bits = static_cast<uint32_t>(offset);
3194 uint32_t j2 = (bits & 0x00080000U) >> 19;
3195 uint32_t j1 = (bits & 0x00040000U) >> 18;
3196 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3197
3198 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3199 }
3200
3201 // R_ARM_ABS8: S + A
3202 static inline typename This::Status
3203 abs8(unsigned char* view,
3204 const Sized_relobj<32, big_endian>* object,
3205 const Symbol_value<32>* psymval)
3206 {
3207 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3208 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3209 Valtype* wv = reinterpret_cast<Valtype*>(view);
3210 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3211 Reltype addend = utils::sign_extend<8>(val);
3212 Reltype x = psymval->value(object, addend);
3213 val = utils::bit_select(val, x, 0xffU);
3214 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3215
3216 // R_ARM_ABS8 permits signed or unsigned results.
3217 int signed_x = static_cast<int32_t>(x);
3218 return ((signed_x < -128 || signed_x > 255)
3219 ? This::STATUS_OVERFLOW
3220 : This::STATUS_OKAY);
3221 }
3222
3223 // R_ARM_THM_ABS5: S + A
3224 static inline typename This::Status
3225 thm_abs5(unsigned char* view,
3226 const Sized_relobj<32, big_endian>* object,
3227 const Symbol_value<32>* psymval)
3228 {
3229 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3230 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3231 Valtype* wv = reinterpret_cast<Valtype*>(view);
3232 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3233 Reltype addend = (val & 0x7e0U) >> 6;
3234 Reltype x = psymval->value(object, addend);
3235 val = utils::bit_select(val, x << 6, 0x7e0U);
3236 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3237
3238 // R_ARM_ABS16 permits signed or unsigned results.
3239 int signed_x = static_cast<int32_t>(x);
3240 return ((signed_x < -32768 || signed_x > 65535)
3241 ? This::STATUS_OVERFLOW
3242 : This::STATUS_OKAY);
3243 }
3244
3245 // R_ARM_ABS12: S + A
3246 static inline typename This::Status
3247 abs12(unsigned char* view,
3248 const Sized_relobj<32, big_endian>* object,
3249 const Symbol_value<32>* psymval)
3250 {
3251 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3252 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3253 Valtype* wv = reinterpret_cast<Valtype*>(view);
3254 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3255 Reltype addend = val & 0x0fffU;
3256 Reltype x = psymval->value(object, addend);
3257 val = utils::bit_select(val, x, 0x0fffU);
3258 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3259 return (utils::has_overflow<12>(x)
3260 ? This::STATUS_OVERFLOW
3261 : This::STATUS_OKAY);
3262 }
3263
3264 // R_ARM_ABS16: S + A
3265 static inline typename This::Status
3266 abs16(unsigned char* view,
3267 const Sized_relobj<32, big_endian>* object,
3268 const Symbol_value<32>* psymval)
3269 {
3270 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3271 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3272 Valtype* wv = reinterpret_cast<Valtype*>(view);
3273 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3274 Reltype addend = utils::sign_extend<16>(val);
3275 Reltype x = psymval->value(object, addend);
3276 val = utils::bit_select(val, x, 0xffffU);
3277 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3278 return (utils::has_signed_unsigned_overflow<16>(x)
3279 ? This::STATUS_OVERFLOW
3280 : This::STATUS_OKAY);
3281 }
3282
3283 // R_ARM_ABS32: (S + A) | T
3284 static inline typename This::Status
3285 abs32(unsigned char* view,
3286 const Sized_relobj<32, big_endian>* object,
3287 const Symbol_value<32>* psymval,
3288 Arm_address thumb_bit)
3289 {
3290 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3291 Valtype* wv = reinterpret_cast<Valtype*>(view);
3292 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3293 Valtype x = psymval->value(object, addend) | thumb_bit;
3294 elfcpp::Swap<32, big_endian>::writeval(wv, 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<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<32, big_endian>::Valtype Valtype;
3307 Valtype* wv = reinterpret_cast<Valtype*>(view);
3308 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3309 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3310 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3311 return This::STATUS_OKAY;
3312 }
3313
3314 // R_ARM_THM_JUMP24: (S + A) | T - P
3315 static typename This::Status
3316 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3317 const Symbol_value<32>* psymval, Arm_address address,
3318 Arm_address thumb_bit);
3319
3320 // R_ARM_THM_JUMP6: S + A – P
3321 static inline typename This::Status
3322 thm_jump6(unsigned char* view,
3323 const Sized_relobj<32, big_endian>* object,
3324 const Symbol_value<32>* psymval,
3325 Arm_address address)
3326 {
3327 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3328 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3329 Valtype* wv = reinterpret_cast<Valtype*>(view);
3330 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3331 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3332 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3333 Reltype x = (psymval->value(object, addend) - address);
3334 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3335 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3336 // CZB does only forward jumps.
3337 return ((x > 0x007e)
3338 ? This::STATUS_OVERFLOW
3339 : This::STATUS_OKAY);
3340 }
3341
3342 // R_ARM_THM_JUMP8: S + A – P
3343 static inline typename This::Status
3344 thm_jump8(unsigned char* view,
3345 const Sized_relobj<32, big_endian>* object,
3346 const Symbol_value<32>* psymval,
3347 Arm_address address)
3348 {
3349 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3350 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3351 Valtype* wv = reinterpret_cast<Valtype*>(view);
3352 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3353 Reltype addend = utils::sign_extend<8>((val & 0x00ff) << 1);
3354 Reltype x = (psymval->value(object, addend) - address);
3355 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xff00) | ((x & 0x01fe) >> 1));
3356 return (utils::has_overflow<8>(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<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 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3370 Valtype* wv = reinterpret_cast<Valtype*>(view);
3371 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3372 Reltype addend = utils::sign_extend<11>((val & 0x07ff) << 1);
3373 Reltype x = (psymval->value(object, addend) - address);
3374 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xf800) | ((x & 0x0ffe) >> 1));
3375 return (utils::has_overflow<11>(x)
3376 ? This::STATUS_OVERFLOW
3377 : This::STATUS_OKAY);
3378 }
3379
3380 // R_ARM_BASE_PREL: B(S) + A - P
3381 static inline typename This::Status
3382 base_prel(unsigned char* view,
3383 Arm_address origin,
3384 Arm_address address)
3385 {
3386 Base::rel32(view, origin - address);
3387 return STATUS_OKAY;
3388 }
3389
3390 // R_ARM_BASE_ABS: B(S) + A
3391 static inline typename This::Status
3392 base_abs(unsigned char* view,
3393 Arm_address origin)
3394 {
3395 Base::rel32(view, origin);
3396 return STATUS_OKAY;
3397 }
3398
3399 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3400 static inline typename This::Status
3401 got_brel(unsigned char* view,
3402 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3403 {
3404 Base::rel32(view, got_offset);
3405 return This::STATUS_OKAY;
3406 }
3407
3408 // R_ARM_GOT_PREL: GOT(S) + A - P
3409 static inline typename This::Status
3410 got_prel(unsigned char* view,
3411 Arm_address got_entry,
3412 Arm_address address)
3413 {
3414 Base::rel32(view, got_entry - address);
3415 return This::STATUS_OKAY;
3416 }
3417
3418 // R_ARM_PREL: (S + A) | T - P
3419 static inline typename This::Status
3420 prel31(unsigned char* view,
3421 const Sized_relobj<32, big_endian>* object,
3422 const Symbol_value<32>* psymval,
3423 Arm_address address,
3424 Arm_address thumb_bit)
3425 {
3426 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3427 Valtype* wv = reinterpret_cast<Valtype*>(view);
3428 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3429 Valtype addend = utils::sign_extend<31>(val);
3430 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3431 val = utils::bit_select(val, x, 0x7fffffffU);
3432 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3433 return (utils::has_overflow<31>(x) ?
3434 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3435 }
3436
3437 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3438 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3439 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3440 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3441 static inline typename This::Status
3442 movw(unsigned char* view,
3443 const Sized_relobj<32, big_endian>* object,
3444 const Symbol_value<32>* psymval,
3445 Arm_address relative_address_base,
3446 Arm_address thumb_bit,
3447 bool check_overflow)
3448 {
3449 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3450 Valtype* wv = reinterpret_cast<Valtype*>(view);
3451 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3452 Valtype addend = This::extract_arm_movw_movt_addend(val);
3453 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3454 - relative_address_base);
3455 val = This::insert_val_arm_movw_movt(val, x);
3456 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3457 return ((check_overflow && utils::has_overflow<16>(x))
3458 ? This::STATUS_OVERFLOW
3459 : This::STATUS_OKAY);
3460 }
3461
3462 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3463 // R_ARM_MOVT_PREL: S + A - P
3464 // R_ARM_MOVT_BREL: S + A - B(S)
3465 static inline typename This::Status
3466 movt(unsigned char* view,
3467 const Sized_relobj<32, big_endian>* object,
3468 const Symbol_value<32>* psymval,
3469 Arm_address relative_address_base)
3470 {
3471 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3472 Valtype* wv = reinterpret_cast<Valtype*>(view);
3473 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3474 Valtype addend = This::extract_arm_movw_movt_addend(val);
3475 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3476 val = This::insert_val_arm_movw_movt(val, x);
3477 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3478 // FIXME: IHI0044D says that we should check for overflow.
3479 return This::STATUS_OKAY;
3480 }
3481
3482 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3483 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3484 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3485 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3486 static inline typename This::Status
3487 thm_movw(unsigned char* view,
3488 const Sized_relobj<32, big_endian>* object,
3489 const Symbol_value<32>* psymval,
3490 Arm_address relative_address_base,
3491 Arm_address thumb_bit,
3492 bool check_overflow)
3493 {
3494 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3495 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3496 Valtype* wv = reinterpret_cast<Valtype*>(view);
3497 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3498 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3499 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3500 Reltype x =
3501 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3502 val = This::insert_val_thumb_movw_movt(val, x);
3503 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3504 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3505 return ((check_overflow && utils::has_overflow<16>(x))
3506 ? This::STATUS_OVERFLOW
3507 : This::STATUS_OKAY);
3508 }
3509
3510 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3511 // R_ARM_THM_MOVT_PREL: S + A - P
3512 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3513 static inline typename This::Status
3514 thm_movt(unsigned char* view,
3515 const Sized_relobj<32, big_endian>* object,
3516 const Symbol_value<32>* psymval,
3517 Arm_address relative_address_base)
3518 {
3519 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3520 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3521 Valtype* wv = reinterpret_cast<Valtype*>(view);
3522 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3523 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3524 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3525 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3526 val = This::insert_val_thumb_movw_movt(val, x);
3527 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3528 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3529 return This::STATUS_OKAY;
3530 }
3531
3532 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3533 static inline typename This::Status
3534 thm_alu11(unsigned char* view,
3535 const Sized_relobj<32, big_endian>* object,
3536 const Symbol_value<32>* psymval,
3537 Arm_address address,
3538 Arm_address thumb_bit)
3539 {
3540 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3541 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3542 Valtype* wv = reinterpret_cast<Valtype*>(view);
3543 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3544 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3545
3546 // 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
3547 // -----------------------------------------------------------------------
3548 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3549 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3550 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3551 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3552 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3553 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3554
3555 // Determine a sign for the addend.
3556 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3557 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3558 // Thumb2 addend encoding:
3559 // imm12 := i | imm3 | imm8
3560 int32_t addend = (insn & 0xff)
3561 | ((insn & 0x00007000) >> 4)
3562 | ((insn & 0x04000000) >> 15);
3563 // Apply a sign to the added.
3564 addend *= sign;
3565
3566 int32_t x = (psymval->value(object, addend) | thumb_bit)
3567 - (address & 0xfffffffc);
3568 Reltype val = abs(x);
3569 // Mask out the value and a distinct part of the ADD/SUB opcode
3570 // (bits 7:5 of opword).
3571 insn = (insn & 0xfb0f8f00)
3572 | (val & 0xff)
3573 | ((val & 0x700) << 4)
3574 | ((val & 0x800) << 15);
3575 // Set the opcode according to whether the value to go in the
3576 // place is negative.
3577 if (x < 0)
3578 insn |= 0x00a00000;
3579
3580 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3581 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3582 return ((val > 0xfff) ?
3583 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3584 }
3585
3586 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3587 static inline typename This::Status
3588 thm_pc8(unsigned char* view,
3589 const Sized_relobj<32, big_endian>* object,
3590 const Symbol_value<32>* psymval,
3591 Arm_address address)
3592 {
3593 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3594 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3595 Valtype* wv = reinterpret_cast<Valtype*>(view);
3596 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3597 Reltype addend = ((insn & 0x00ff) << 2);
3598 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3599 Reltype val = abs(x);
3600 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3601
3602 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3603 return ((val > 0x03fc)
3604 ? This::STATUS_OVERFLOW
3605 : This::STATUS_OKAY);
3606 }
3607
3608 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3609 static inline typename This::Status
3610 thm_pc12(unsigned char* view,
3611 const Sized_relobj<32, big_endian>* object,
3612 const Symbol_value<32>* psymval,
3613 Arm_address address)
3614 {
3615 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3616 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3617 Valtype* wv = reinterpret_cast<Valtype*>(view);
3618 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3619 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3620 // Determine a sign for the addend (positive if the U bit is 1).
3621 const int sign = (insn & 0x00800000) ? 1 : -1;
3622 int32_t addend = (insn & 0xfff);
3623 // Apply a sign to the added.
3624 addend *= sign;
3625
3626 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3627 Reltype val = abs(x);
3628 // Mask out and apply the value and the U bit.
3629 insn = (insn & 0xff7ff000) | (val & 0xfff);
3630 // Set the U bit according to whether the value to go in the
3631 // place is positive.
3632 if (x >= 0)
3633 insn |= 0x00800000;
3634
3635 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3636 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3637 return ((val > 0xfff) ?
3638 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3639 }
3640
3641 // R_ARM_V4BX
3642 static inline typename This::Status
3643 v4bx(const Relocate_info<32, big_endian>* relinfo,
3644 unsigned char* view,
3645 const Arm_relobj<big_endian>* object,
3646 const Arm_address address,
3647 const bool is_interworking)
3648 {
3649
3650 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3651 Valtype* wv = reinterpret_cast<Valtype*>(view);
3652 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3653
3654 // Ensure that we have a BX instruction.
3655 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3656 const uint32_t reg = (val & 0xf);
3657 if (is_interworking && reg != 0xf)
3658 {
3659 Stub_table<big_endian>* stub_table =
3660 object->stub_table(relinfo->data_shndx);
3661 gold_assert(stub_table != NULL);
3662
3663 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3664 gold_assert(stub != NULL);
3665
3666 int32_t veneer_address =
3667 stub_table->address() + stub->offset() - 8 - address;
3668 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3669 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3670 // Replace with a branch to veneer (B <addr>)
3671 val = (val & 0xf0000000) | 0x0a000000
3672 | ((veneer_address >> 2) & 0x00ffffff);
3673 }
3674 else
3675 {
3676 // Preserve Rm (lowest four bits) and the condition code
3677 // (highest four bits). Other bits encode MOV PC,Rm.
3678 val = (val & 0xf000000f) | 0x01a0f000;
3679 }
3680 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3681 return This::STATUS_OKAY;
3682 }
3683
3684 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3685 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3686 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3687 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3688 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3689 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3690 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3691 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3692 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3693 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3694 static inline typename This::Status
3695 arm_grp_alu(unsigned char* view,
3696 const Sized_relobj<32, big_endian>* object,
3697 const Symbol_value<32>* psymval,
3698 const int group,
3699 Arm_address address,
3700 Arm_address thumb_bit,
3701 bool check_overflow)
3702 {
3703 gold_assert(group >= 0 && group < 3);
3704 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3705 Valtype* wv = reinterpret_cast<Valtype*>(view);
3706 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3707
3708 // ALU group relocations are allowed only for the ADD/SUB instructions.
3709 // (0x00800000 - ADD, 0x00400000 - SUB)
3710 const Valtype opcode = insn & 0x01e00000;
3711 if (opcode != 0x00800000 && opcode != 0x00400000)
3712 return This::STATUS_BAD_RELOC;
3713
3714 // Determine a sign for the addend.
3715 const int sign = (opcode == 0x00800000) ? 1 : -1;
3716 // shifter = rotate_imm * 2
3717 const uint32_t shifter = (insn & 0xf00) >> 7;
3718 // Initial addend value.
3719 int32_t addend = insn & 0xff;
3720 // Rotate addend right by shifter.
3721 addend = (addend >> shifter) | (addend << (32 - shifter));
3722 // Apply a sign to the added.
3723 addend *= sign;
3724
3725 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3726 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3727 // Check for overflow if required
3728 if (check_overflow
3729 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3730 return This::STATUS_OVERFLOW;
3731
3732 // Mask out the value and the ADD/SUB part of the opcode; take care
3733 // not to destroy the S bit.
3734 insn &= 0xff1ff000;
3735 // Set the opcode according to whether the value to go in the
3736 // place is negative.
3737 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3738 // Encode the offset (encoded Gn).
3739 insn |= gn;
3740
3741 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3742 return This::STATUS_OKAY;
3743 }
3744
3745 // R_ARM_LDR_PC_G0: S + A - P
3746 // R_ARM_LDR_PC_G1: S + A - P
3747 // R_ARM_LDR_PC_G2: S + A - P
3748 // R_ARM_LDR_SB_G0: S + A - B(S)
3749 // R_ARM_LDR_SB_G1: S + A - B(S)
3750 // R_ARM_LDR_SB_G2: S + A - B(S)
3751 static inline typename This::Status
3752 arm_grp_ldr(unsigned char* view,
3753 const Sized_relobj<32, big_endian>* object,
3754 const Symbol_value<32>* psymval,
3755 const int group,
3756 Arm_address address)
3757 {
3758 gold_assert(group >= 0 && group < 3);
3759 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3760 Valtype* wv = reinterpret_cast<Valtype*>(view);
3761 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3762
3763 const int sign = (insn & 0x00800000) ? 1 : -1;
3764 int32_t addend = (insn & 0xfff) * sign;
3765 int32_t x = (psymval->value(object, addend) - address);
3766 // Calculate the relevant G(n-1) value to obtain this stage residual.
3767 Valtype residual =
3768 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3769 if (residual >= 0x1000)
3770 return This::STATUS_OVERFLOW;
3771
3772 // Mask out the value and U bit.
3773 insn &= 0xff7ff000;
3774 // Set the U bit for non-negative values.
3775 if (x >= 0)
3776 insn |= 0x00800000;
3777 insn |= residual;
3778
3779 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3780 return This::STATUS_OKAY;
3781 }
3782
3783 // R_ARM_LDRS_PC_G0: S + A - P
3784 // R_ARM_LDRS_PC_G1: S + A - P
3785 // R_ARM_LDRS_PC_G2: S + A - P
3786 // R_ARM_LDRS_SB_G0: S + A - B(S)
3787 // R_ARM_LDRS_SB_G1: S + A - B(S)
3788 // R_ARM_LDRS_SB_G2: S + A - B(S)
3789 static inline typename This::Status
3790 arm_grp_ldrs(unsigned char* view,
3791 const Sized_relobj<32, big_endian>* object,
3792 const Symbol_value<32>* psymval,
3793 const int group,
3794 Arm_address address)
3795 {
3796 gold_assert(group >= 0 && group < 3);
3797 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3798 Valtype* wv = reinterpret_cast<Valtype*>(view);
3799 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3800
3801 const int sign = (insn & 0x00800000) ? 1 : -1;
3802 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3803 int32_t x = (psymval->value(object, addend) - address);
3804 // Calculate the relevant G(n-1) value to obtain this stage residual.
3805 Valtype residual =
3806 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3807 if (residual >= 0x100)
3808 return This::STATUS_OVERFLOW;
3809
3810 // Mask out the value and U bit.
3811 insn &= 0xff7ff0f0;
3812 // Set the U bit for non-negative values.
3813 if (x >= 0)
3814 insn |= 0x00800000;
3815 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3816
3817 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3818 return This::STATUS_OKAY;
3819 }
3820
3821 // R_ARM_LDC_PC_G0: S + A - P
3822 // R_ARM_LDC_PC_G1: S + A - P
3823 // R_ARM_LDC_PC_G2: S + A - P
3824 // R_ARM_LDC_SB_G0: S + A - B(S)
3825 // R_ARM_LDC_SB_G1: S + A - B(S)
3826 // R_ARM_LDC_SB_G2: S + A - B(S)
3827 static inline typename This::Status
3828 arm_grp_ldc(unsigned char* view,
3829 const Sized_relobj<32, big_endian>* object,
3830 const Symbol_value<32>* psymval,
3831 const int group,
3832 Arm_address address)
3833 {
3834 gold_assert(group >= 0 && group < 3);
3835 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3836 Valtype* wv = reinterpret_cast<Valtype*>(view);
3837 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3838
3839 const int sign = (insn & 0x00800000) ? 1 : -1;
3840 int32_t addend = ((insn & 0xff) << 2) * sign;
3841 int32_t x = (psymval->value(object, addend) - address);
3842 // Calculate the relevant G(n-1) value to obtain this stage residual.
3843 Valtype residual =
3844 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3845 if ((residual & 0x3) != 0 || residual >= 0x400)
3846 return This::STATUS_OVERFLOW;
3847
3848 // Mask out the value and U bit.
3849 insn &= 0xff7fff00;
3850 // Set the U bit for non-negative values.
3851 if (x >= 0)
3852 insn |= 0x00800000;
3853 insn |= (residual >> 2);
3854
3855 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3856 return This::STATUS_OKAY;
3857 }
3858 };
3859
3860 // Relocate ARM long branches. This handles relocation types
3861 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3862 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3863 // undefined and we do not use PLT in this relocation. In such a case,
3864 // the branch is converted into an NOP.
3865
3866 template<bool big_endian>
3867 typename Arm_relocate_functions<big_endian>::Status
3868 Arm_relocate_functions<big_endian>::arm_branch_common(
3869 unsigned int r_type,
3870 const Relocate_info<32, big_endian>* relinfo,
3871 unsigned char* view,
3872 const Sized_symbol<32>* gsym,
3873 const Arm_relobj<big_endian>* object,
3874 unsigned int r_sym,
3875 const Symbol_value<32>* psymval,
3876 Arm_address address,
3877 Arm_address thumb_bit,
3878 bool is_weakly_undefined_without_plt)
3879 {
3880 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3881 Valtype* wv = reinterpret_cast<Valtype*>(view);
3882 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3883
3884 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3885 && ((val & 0x0f000000UL) == 0x0a000000UL);
3886 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3887 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3888 && ((val & 0x0f000000UL) == 0x0b000000UL);
3889 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3890 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3891
3892 // Check that the instruction is valid.
3893 if (r_type == elfcpp::R_ARM_CALL)
3894 {
3895 if (!insn_is_uncond_bl && !insn_is_blx)
3896 return This::STATUS_BAD_RELOC;
3897 }
3898 else if (r_type == elfcpp::R_ARM_JUMP24)
3899 {
3900 if (!insn_is_b && !insn_is_cond_bl)
3901 return This::STATUS_BAD_RELOC;
3902 }
3903 else if (r_type == elfcpp::R_ARM_PLT32)
3904 {
3905 if (!insn_is_any_branch)
3906 return This::STATUS_BAD_RELOC;
3907 }
3908 else if (r_type == elfcpp::R_ARM_XPC25)
3909 {
3910 // FIXME: AAELF document IH0044C does not say much about it other
3911 // than it being obsolete.
3912 if (!insn_is_any_branch)
3913 return This::STATUS_BAD_RELOC;
3914 }
3915 else
3916 gold_unreachable();
3917
3918 // A branch to an undefined weak symbol is turned into a jump to
3919 // the next instruction unless a PLT entry will be created.
3920 // Do the same for local undefined symbols.
3921 // The jump to the next instruction is optimized as a NOP depending
3922 // on the architecture.
3923 const Target_arm<big_endian>* arm_target =
3924 Target_arm<big_endian>::default_target();
3925 if (is_weakly_undefined_without_plt)
3926 {
3927 gold_assert(!parameters->options().relocatable());
3928 Valtype cond = val & 0xf0000000U;
3929 if (arm_target->may_use_arm_nop())
3930 val = cond | 0x0320f000;
3931 else
3932 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3933 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3934 return This::STATUS_OKAY;
3935 }
3936
3937 Valtype addend = utils::sign_extend<26>(val << 2);
3938 Valtype branch_target = psymval->value(object, addend);
3939 int32_t branch_offset = branch_target - address;
3940
3941 // We need a stub if the branch offset is too large or if we need
3942 // to switch mode.
3943 bool may_use_blx = arm_target->may_use_blx();
3944 Reloc_stub* stub = NULL;
3945
3946 if (!parameters->options().relocatable()
3947 && (utils::has_overflow<26>(branch_offset)
3948 || ((thumb_bit != 0)
3949 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3950 {
3951 Valtype unadjusted_branch_target = psymval->value(object, 0);
3952
3953 Stub_type stub_type =
3954 Reloc_stub::stub_type_for_reloc(r_type, address,
3955 unadjusted_branch_target,
3956 (thumb_bit != 0));
3957 if (stub_type != arm_stub_none)
3958 {
3959 Stub_table<big_endian>* stub_table =
3960 object->stub_table(relinfo->data_shndx);
3961 gold_assert(stub_table != NULL);
3962
3963 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3964 stub = stub_table->find_reloc_stub(stub_key);
3965 gold_assert(stub != NULL);
3966 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3967 branch_target = stub_table->address() + stub->offset() + addend;
3968 branch_offset = branch_target - address;
3969 gold_assert(!utils::has_overflow<26>(branch_offset));
3970 }
3971 }
3972
3973 // At this point, if we still need to switch mode, the instruction
3974 // must either be a BLX or a BL that can be converted to a BLX.
3975 if (thumb_bit != 0)
3976 {
3977 // Turn BL to BLX.
3978 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3979 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3980 }
3981
3982 val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
3983 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3984 return (utils::has_overflow<26>(branch_offset)
3985 ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
3986 }
3987
3988 // Relocate THUMB long branches. This handles relocation types
3989 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3990 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3991 // undefined and we do not use PLT in this relocation. In such a case,
3992 // the branch is converted into an NOP.
3993
3994 template<bool big_endian>
3995 typename Arm_relocate_functions<big_endian>::Status
3996 Arm_relocate_functions<big_endian>::thumb_branch_common(
3997 unsigned int r_type,
3998 const Relocate_info<32, big_endian>* relinfo,
3999 unsigned char* view,
4000 const Sized_symbol<32>* gsym,
4001 const Arm_relobj<big_endian>* object,
4002 unsigned int r_sym,
4003 const Symbol_value<32>* psymval,
4004 Arm_address address,
4005 Arm_address thumb_bit,
4006 bool is_weakly_undefined_without_plt)
4007 {
4008 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4009 Valtype* wv = reinterpret_cast<Valtype*>(view);
4010 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4011 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4012
4013 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4014 // into account.
4015 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4016 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4017
4018 // Check that the instruction is valid.
4019 if (r_type == elfcpp::R_ARM_THM_CALL)
4020 {
4021 if (!is_bl_insn && !is_blx_insn)
4022 return This::STATUS_BAD_RELOC;
4023 }
4024 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4025 {
4026 // This cannot be a BLX.
4027 if (!is_bl_insn)
4028 return This::STATUS_BAD_RELOC;
4029 }
4030 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4031 {
4032 // Check for Thumb to Thumb call.
4033 if (!is_blx_insn)
4034 return This::STATUS_BAD_RELOC;
4035 if (thumb_bit != 0)
4036 {
4037 gold_warning(_("%s: Thumb BLX instruction targets "
4038 "thumb function '%s'."),
4039 object->name().c_str(),
4040 (gsym ? gsym->name() : "(local)"));
4041 // Convert BLX to BL.
4042 lower_insn |= 0x1000U;
4043 }
4044 }
4045 else
4046 gold_unreachable();
4047
4048 // A branch to an undefined weak symbol is turned into a jump to
4049 // the next instruction unless a PLT entry will be created.
4050 // The jump to the next instruction is optimized as a NOP.W for
4051 // Thumb-2 enabled architectures.
4052 const Target_arm<big_endian>* arm_target =
4053 Target_arm<big_endian>::default_target();
4054 if (is_weakly_undefined_without_plt)
4055 {
4056 gold_assert(!parameters->options().relocatable());
4057 if (arm_target->may_use_thumb2_nop())
4058 {
4059 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4060 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4061 }
4062 else
4063 {
4064 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4065 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4066 }
4067 return This::STATUS_OKAY;
4068 }
4069
4070 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4071 Arm_address branch_target = psymval->value(object, addend);
4072
4073 // For BLX, bit 1 of target address comes from bit 1 of base address.
4074 bool may_use_blx = arm_target->may_use_blx();
4075 if (thumb_bit == 0 && may_use_blx)
4076 branch_target = utils::bit_select(branch_target, address, 0x2);
4077
4078 int32_t branch_offset = branch_target - address;
4079
4080 // We need a stub if the branch offset is too large or if we need
4081 // to switch mode.
4082 bool thumb2 = arm_target->using_thumb2();
4083 if (!parameters->options().relocatable()
4084 && ((!thumb2 && utils::has_overflow<23>(branch_offset))
4085 || (thumb2 && utils::has_overflow<25>(branch_offset))
4086 || ((thumb_bit == 0)
4087 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4088 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4089 {
4090 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4091
4092 Stub_type stub_type =
4093 Reloc_stub::stub_type_for_reloc(r_type, address,
4094 unadjusted_branch_target,
4095 (thumb_bit != 0));
4096
4097 if (stub_type != arm_stub_none)
4098 {
4099 Stub_table<big_endian>* stub_table =
4100 object->stub_table(relinfo->data_shndx);
4101 gold_assert(stub_table != NULL);
4102
4103 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4104 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4105 gold_assert(stub != NULL);
4106 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4107 branch_target = stub_table->address() + stub->offset() + addend;
4108 if (thumb_bit == 0 && may_use_blx)
4109 branch_target = utils::bit_select(branch_target, address, 0x2);
4110 branch_offset = branch_target - address;
4111 }
4112 }
4113
4114 // At this point, if we still need to switch mode, the instruction
4115 // must either be a BLX or a BL that can be converted to a BLX.
4116 if (thumb_bit == 0)
4117 {
4118 gold_assert(may_use_blx
4119 && (r_type == elfcpp::R_ARM_THM_CALL
4120 || r_type == elfcpp::R_ARM_THM_XPC22));
4121 // Make sure this is a BLX.
4122 lower_insn &= ~0x1000U;
4123 }
4124 else
4125 {
4126 // Make sure this is a BL.
4127 lower_insn |= 0x1000U;
4128 }
4129
4130 // For a BLX instruction, make sure that the relocation is rounded up
4131 // to a word boundary. This follows the semantics of the instruction
4132 // which specifies that bit 1 of the target address will come from bit
4133 // 1 of the base address.
4134 if ((lower_insn & 0x5000U) == 0x4000U)
4135 gold_assert((branch_offset & 3) == 0);
4136
4137 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4138 // We use the Thumb-2 encoding, which is safe even if dealing with
4139 // a Thumb-1 instruction by virtue of our overflow check above. */
4140 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4141 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4142
4143 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4144 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4145
4146 gold_assert(!utils::has_overflow<25>(branch_offset));
4147
4148 return ((thumb2
4149 ? utils::has_overflow<25>(branch_offset)
4150 : utils::has_overflow<23>(branch_offset))
4151 ? This::STATUS_OVERFLOW
4152 : This::STATUS_OKAY);
4153 }
4154
4155 // Relocate THUMB-2 long conditional branches.
4156 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4157 // undefined and we do not use PLT in this relocation. In such a case,
4158 // the branch is converted into an NOP.
4159
4160 template<bool big_endian>
4161 typename Arm_relocate_functions<big_endian>::Status
4162 Arm_relocate_functions<big_endian>::thm_jump19(
4163 unsigned char* view,
4164 const Arm_relobj<big_endian>* object,
4165 const Symbol_value<32>* psymval,
4166 Arm_address address,
4167 Arm_address thumb_bit)
4168 {
4169 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4170 Valtype* wv = reinterpret_cast<Valtype*>(view);
4171 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4172 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4173 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4174
4175 Arm_address branch_target = psymval->value(object, addend);
4176 int32_t branch_offset = branch_target - address;
4177
4178 // ??? Should handle interworking? GCC might someday try to
4179 // use this for tail calls.
4180 // FIXME: We do support thumb entry to PLT yet.
4181 if (thumb_bit == 0)
4182 {
4183 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4184 return This::STATUS_BAD_RELOC;
4185 }
4186
4187 // Put RELOCATION back into the insn.
4188 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4189 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4190
4191 // Put the relocated value back in the object file:
4192 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4193 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4194
4195 return (utils::has_overflow<21>(branch_offset)
4196 ? This::STATUS_OVERFLOW
4197 : This::STATUS_OKAY);
4198 }
4199
4200 // Get the GOT section, creating it if necessary.
4201
4202 template<bool big_endian>
4203 Arm_output_data_got<big_endian>*
4204 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4205 {
4206 if (this->got_ == NULL)
4207 {
4208 gold_assert(symtab != NULL && layout != NULL);
4209
4210 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4211
4212 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4213 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4214 this->got_, ORDER_DATA, false);
4215
4216 // The old GNU linker creates a .got.plt section. We just
4217 // create another set of data in the .got section. Note that we
4218 // always create a PLT if we create a GOT, although the PLT
4219 // might be empty.
4220 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4221 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4222 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4223 this->got_plt_, ORDER_DATA, false);
4224
4225 // The first three entries are reserved.
4226 this->got_plt_->set_current_data_size(3 * 4);
4227
4228 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4229 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4230 Symbol_table::PREDEFINED,
4231 this->got_plt_,
4232 0, 0, elfcpp::STT_OBJECT,
4233 elfcpp::STB_LOCAL,
4234 elfcpp::STV_HIDDEN, 0,
4235 false, false);
4236 }
4237 return this->got_;
4238 }
4239
4240 // Get the dynamic reloc section, creating it if necessary.
4241
4242 template<bool big_endian>
4243 typename Target_arm<big_endian>::Reloc_section*
4244 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4245 {
4246 if (this->rel_dyn_ == NULL)
4247 {
4248 gold_assert(layout != NULL);
4249 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4250 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4251 elfcpp::SHF_ALLOC, this->rel_dyn_,
4252 ORDER_DYNAMIC_RELOCS, false);
4253 }
4254 return this->rel_dyn_;
4255 }
4256
4257 // Insn_template methods.
4258
4259 // Return byte size of an instruction template.
4260
4261 size_t
4262 Insn_template::size() const
4263 {
4264 switch (this->type())
4265 {
4266 case THUMB16_TYPE:
4267 case THUMB16_SPECIAL_TYPE:
4268 return 2;
4269 case ARM_TYPE:
4270 case THUMB32_TYPE:
4271 case DATA_TYPE:
4272 return 4;
4273 default:
4274 gold_unreachable();
4275 }
4276 }
4277
4278 // Return alignment of an instruction template.
4279
4280 unsigned
4281 Insn_template::alignment() const
4282 {
4283 switch (this->type())
4284 {
4285 case THUMB16_TYPE:
4286 case THUMB16_SPECIAL_TYPE:
4287 case THUMB32_TYPE:
4288 return 2;
4289 case ARM_TYPE:
4290 case DATA_TYPE:
4291 return 4;
4292 default:
4293 gold_unreachable();
4294 }
4295 }
4296
4297 // Stub_template methods.
4298
4299 Stub_template::Stub_template(
4300 Stub_type type, const Insn_template* insns,
4301 size_t insn_count)
4302 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4303 entry_in_thumb_mode_(false), relocs_()
4304 {
4305 off_t offset = 0;
4306
4307 // Compute byte size and alignment of stub template.
4308 for (size_t i = 0; i < insn_count; i++)
4309 {
4310 unsigned insn_alignment = insns[i].alignment();
4311 size_t insn_size = insns[i].size();
4312 gold_assert((offset & (insn_alignment - 1)) == 0);
4313 this->alignment_ = std::max(this->alignment_, insn_alignment);
4314 switch (insns[i].type())
4315 {
4316 case Insn_template::THUMB16_TYPE:
4317 case Insn_template::THUMB16_SPECIAL_TYPE:
4318 if (i == 0)
4319 this->entry_in_thumb_mode_ = true;
4320 break;
4321
4322 case Insn_template::THUMB32_TYPE:
4323 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4324 this->relocs_.push_back(Reloc(i, offset));
4325 if (i == 0)
4326 this->entry_in_thumb_mode_ = true;
4327 break;
4328
4329 case Insn_template::ARM_TYPE:
4330 // Handle cases where the target is encoded within the
4331 // instruction.
4332 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4333 this->relocs_.push_back(Reloc(i, offset));
4334 break;
4335
4336 case Insn_template::DATA_TYPE:
4337 // Entry point cannot be data.
4338 gold_assert(i != 0);
4339 this->relocs_.push_back(Reloc(i, offset));
4340 break;
4341
4342 default:
4343 gold_unreachable();
4344 }
4345 offset += insn_size;
4346 }
4347 this->size_ = offset;
4348 }
4349
4350 // Stub methods.
4351
4352 // Template to implement do_write for a specific target endianness.
4353
4354 template<bool big_endian>
4355 void inline
4356 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4357 {
4358 const Stub_template* stub_template = this->stub_template();
4359 const Insn_template* insns = stub_template->insns();
4360
4361 // FIXME: We do not handle BE8 encoding yet.
4362 unsigned char* pov = view;
4363 for (size_t i = 0; i < stub_template->insn_count(); i++)
4364 {
4365 switch (insns[i].type())
4366 {
4367 case Insn_template::THUMB16_TYPE:
4368 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4369 break;
4370 case Insn_template::THUMB16_SPECIAL_TYPE:
4371 elfcpp::Swap<16, big_endian>::writeval(
4372 pov,
4373 this->thumb16_special(i));
4374 break;
4375 case Insn_template::THUMB32_TYPE:
4376 {
4377 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4378 uint32_t lo = insns[i].data() & 0xffff;
4379 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4380 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4381 }
4382 break;
4383 case Insn_template::ARM_TYPE:
4384 case Insn_template::DATA_TYPE:
4385 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4386 break;
4387 default:
4388 gold_unreachable();
4389 }
4390 pov += insns[i].size();
4391 }
4392 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4393 }
4394
4395 // Reloc_stub::Key methods.
4396
4397 // Dump a Key as a string for debugging.
4398
4399 std::string
4400 Reloc_stub::Key::name() const
4401 {
4402 if (this->r_sym_ == invalid_index)
4403 {
4404 // Global symbol key name
4405 // <stub-type>:<symbol name>:<addend>.
4406 const std::string sym_name = this->u_.symbol->name();
4407 // We need to print two hex number and two colons. So just add 100 bytes
4408 // to the symbol name size.
4409 size_t len = sym_name.size() + 100;
4410 char* buffer = new char[len];
4411 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4412 sym_name.c_str(), this->addend_);
4413 gold_assert(c > 0 && c < static_cast<int>(len));
4414 delete[] buffer;
4415 return std::string(buffer);
4416 }
4417 else
4418 {
4419 // local symbol key name
4420 // <stub-type>:<object>:<r_sym>:<addend>.
4421 const size_t len = 200;
4422 char buffer[len];
4423 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4424 this->u_.relobj, this->r_sym_, this->addend_);
4425 gold_assert(c > 0 && c < static_cast<int>(len));
4426 return std::string(buffer);
4427 }
4428 }
4429
4430 // Reloc_stub methods.
4431
4432 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4433 // LOCATION to DESTINATION.
4434 // This code is based on the arm_type_of_stub function in
4435 // bfd/elf32-arm.c. We have changed the interface a liitle to keep the Stub
4436 // class simple.
4437
4438 Stub_type
4439 Reloc_stub::stub_type_for_reloc(
4440 unsigned int r_type,
4441 Arm_address location,
4442 Arm_address destination,
4443 bool target_is_thumb)
4444 {
4445 Stub_type stub_type = arm_stub_none;
4446
4447 // This is a bit ugly but we want to avoid using a templated class for
4448 // big and little endianities.
4449 bool may_use_blx;
4450 bool should_force_pic_veneer;
4451 bool thumb2;
4452 bool thumb_only;
4453 if (parameters->target().is_big_endian())
4454 {
4455 const Target_arm<true>* big_endian_target =
4456 Target_arm<true>::default_target();
4457 may_use_blx = big_endian_target->may_use_blx();
4458 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4459 thumb2 = big_endian_target->using_thumb2();
4460 thumb_only = big_endian_target->using_thumb_only();
4461 }
4462 else
4463 {
4464 const Target_arm<false>* little_endian_target =
4465 Target_arm<false>::default_target();
4466 may_use_blx = little_endian_target->may_use_blx();
4467 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4468 thumb2 = little_endian_target->using_thumb2();
4469 thumb_only = little_endian_target->using_thumb_only();
4470 }
4471
4472 int64_t branch_offset;
4473 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4474 {
4475 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4476 // base address (instruction address + 4).
4477 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4478 destination = utils::bit_select(destination, location, 0x2);
4479 branch_offset = static_cast<int64_t>(destination) - location;
4480
4481 // Handle cases where:
4482 // - this call goes too far (different Thumb/Thumb2 max
4483 // distance)
4484 // - it's a Thumb->Arm call and blx is not available, or it's a
4485 // Thumb->Arm branch (not bl). A stub is needed in this case.
4486 if ((!thumb2
4487 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4488 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4489 || (thumb2
4490 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4491 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4492 || ((!target_is_thumb)
4493 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4494 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4495 {
4496 if (target_is_thumb)
4497 {
4498 // Thumb to thumb.
4499 if (!thumb_only)
4500 {
4501 stub_type = (parameters->options().shared()
4502 || should_force_pic_veneer)
4503 // PIC stubs.
4504 ? ((may_use_blx
4505 && (r_type == elfcpp::R_ARM_THM_CALL))
4506 // V5T and above. Stub starts with ARM code, so
4507 // we must be able to switch mode before
4508 // reaching it, which is only possible for 'bl'
4509 // (ie R_ARM_THM_CALL relocation).
4510 ? arm_stub_long_branch_any_thumb_pic
4511 // On V4T, use Thumb code only.
4512 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4513
4514 // non-PIC stubs.
4515 : ((may_use_blx
4516 && (r_type == elfcpp::R_ARM_THM_CALL))
4517 ? arm_stub_long_branch_any_any // V5T and above.
4518 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4519 }
4520 else
4521 {
4522 stub_type = (parameters->options().shared()
4523 || should_force_pic_veneer)
4524 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4525 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4526 }
4527 }
4528 else
4529 {
4530 // Thumb to arm.
4531
4532 // FIXME: We should check that the input section is from an
4533 // object that has interwork enabled.
4534
4535 stub_type = (parameters->options().shared()
4536 || should_force_pic_veneer)
4537 // PIC stubs.
4538 ? ((may_use_blx
4539 && (r_type == elfcpp::R_ARM_THM_CALL))
4540 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4541 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4542
4543 // non-PIC stubs.
4544 : ((may_use_blx
4545 && (r_type == elfcpp::R_ARM_THM_CALL))
4546 ? arm_stub_long_branch_any_any // V5T and above.
4547 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4548
4549 // Handle v4t short branches.
4550 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4551 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4552 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4553 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4554 }
4555 }
4556 }
4557 else if (r_type == elfcpp::R_ARM_CALL
4558 || r_type == elfcpp::R_ARM_JUMP24
4559 || r_type == elfcpp::R_ARM_PLT32)
4560 {
4561 branch_offset = static_cast<int64_t>(destination) - location;
4562 if (target_is_thumb)
4563 {
4564 // Arm to thumb.
4565
4566 // FIXME: We should check that the input section is from an
4567 // object that has interwork enabled.
4568
4569 // We have an extra 2-bytes reach because of
4570 // the mode change (bit 24 (H) of BLX encoding).
4571 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4572 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4573 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4574 || (r_type == elfcpp::R_ARM_JUMP24)
4575 || (r_type == elfcpp::R_ARM_PLT32))
4576 {
4577 stub_type = (parameters->options().shared()
4578 || should_force_pic_veneer)
4579 // PIC stubs.
4580 ? (may_use_blx
4581 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4582 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4583
4584 // non-PIC stubs.
4585 : (may_use_blx
4586 ? arm_stub_long_branch_any_any // V5T and above.
4587 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4588 }
4589 }
4590 else
4591 {
4592 // Arm to arm.
4593 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4594 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4595 {
4596 stub_type = (parameters->options().shared()
4597 || should_force_pic_veneer)
4598 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4599 : arm_stub_long_branch_any_any; /// non-PIC.
4600 }
4601 }
4602 }
4603
4604 return stub_type;
4605 }
4606
4607 // Cortex_a8_stub methods.
4608
4609 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4610 // I is the position of the instruction template in the stub template.
4611
4612 uint16_t
4613 Cortex_a8_stub::do_thumb16_special(size_t i)
4614 {
4615 // The only use of this is to copy condition code from a conditional
4616 // branch being worked around to the corresponding conditional branch in
4617 // to the stub.
4618 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4619 && i == 0);
4620 uint16_t data = this->stub_template()->insns()[i].data();
4621 gold_assert((data & 0xff00U) == 0xd000U);
4622 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4623 return data;
4624 }
4625
4626 // Stub_factory methods.
4627
4628 Stub_factory::Stub_factory()
4629 {
4630 // The instruction template sequences are declared as static
4631 // objects and initialized first time the constructor runs.
4632
4633 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4634 // to reach the stub if necessary.
4635 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4636 {
4637 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4638 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4639 // dcd R_ARM_ABS32(X)
4640 };
4641
4642 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4643 // available.
4644 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4645 {
4646 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4647 Insn_template::arm_insn(0xe12fff1c), // bx ip
4648 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4649 // dcd R_ARM_ABS32(X)
4650 };
4651
4652 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4653 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4654 {
4655 Insn_template::thumb16_insn(0xb401), // push {r0}
4656 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4657 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4658 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4659 Insn_template::thumb16_insn(0x4760), // bx ip
4660 Insn_template::thumb16_insn(0xbf00), // nop
4661 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4662 // dcd R_ARM_ABS32(X)
4663 };
4664
4665 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4666 // allowed.
4667 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4668 {
4669 Insn_template::thumb16_insn(0x4778), // bx pc
4670 Insn_template::thumb16_insn(0x46c0), // nop
4671 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4672 Insn_template::arm_insn(0xe12fff1c), // bx ip
4673 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4674 // dcd R_ARM_ABS32(X)
4675 };
4676
4677 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4678 // available.
4679 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4680 {
4681 Insn_template::thumb16_insn(0x4778), // bx pc
4682 Insn_template::thumb16_insn(0x46c0), // nop
4683 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4684 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4685 // dcd R_ARM_ABS32(X)
4686 };
4687
4688 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4689 // one, when the destination is close enough.
4690 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4691 {
4692 Insn_template::thumb16_insn(0x4778), // bx pc
4693 Insn_template::thumb16_insn(0x46c0), // nop
4694 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4695 };
4696
4697 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4698 // blx to reach the stub if necessary.
4699 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4700 {
4701 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4702 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4703 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4704 // dcd R_ARM_REL32(X-4)
4705 };
4706
4707 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4708 // blx to reach the stub if necessary. We can not add into pc;
4709 // it is not guaranteed to mode switch (different in ARMv6 and
4710 // ARMv7).
4711 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4712 {
4713 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4714 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4715 Insn_template::arm_insn(0xe12fff1c), // bx ip
4716 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4717 // dcd R_ARM_REL32(X)
4718 };
4719
4720 // V4T ARM -> ARM long branch stub, PIC.
4721 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4722 {
4723 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4724 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4725 Insn_template::arm_insn(0xe12fff1c), // bx ip
4726 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4727 // dcd R_ARM_REL32(X)
4728 };
4729
4730 // V4T Thumb -> ARM long branch stub, PIC.
4731 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4732 {
4733 Insn_template::thumb16_insn(0x4778), // bx pc
4734 Insn_template::thumb16_insn(0x46c0), // nop
4735 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4736 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4737 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4738 // dcd R_ARM_REL32(X)
4739 };
4740
4741 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4742 // architectures.
4743 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4744 {
4745 Insn_template::thumb16_insn(0xb401), // push {r0}
4746 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4747 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4748 Insn_template::thumb16_insn(0x4484), // add ip, r0
4749 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4750 Insn_template::thumb16_insn(0x4760), // bx ip
4751 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4752 // dcd R_ARM_REL32(X)
4753 };
4754
4755 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4756 // allowed.
4757 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4758 {
4759 Insn_template::thumb16_insn(0x4778), // bx pc
4760 Insn_template::thumb16_insn(0x46c0), // nop
4761 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4762 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4763 Insn_template::arm_insn(0xe12fff1c), // bx ip
4764 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4765 // dcd R_ARM_REL32(X)
4766 };
4767
4768 // Cortex-A8 erratum-workaround stubs.
4769
4770 // Stub used for conditional branches (which may be beyond +/-1MB away,
4771 // so we can't use a conditional branch to reach this stub).
4772
4773 // original code:
4774 //
4775 // b<cond> X
4776 // after:
4777 //
4778 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4779 {
4780 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4781 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4782 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4783 // b.w X
4784 };
4785
4786 // Stub used for b.w and bl.w instructions.
4787
4788 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4789 {
4790 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4791 };
4792
4793 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4794 {
4795 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4796 };
4797
4798 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4799 // instruction (which switches to ARM mode) to point to this stub. Jump to
4800 // the real destination using an ARM-mode branch.
4801 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4802 {
4803 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4804 };
4805
4806 // Stub used to provide an interworking for R_ARM_V4BX relocation
4807 // (bx r[n] instruction).
4808 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4809 {
4810 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4811 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4812 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4813 };
4814
4815 // Fill in the stub template look-up table. Stub templates are constructed
4816 // per instance of Stub_factory for fast look-up without locking
4817 // in a thread-enabled environment.
4818
4819 this->stub_templates_[arm_stub_none] =
4820 new Stub_template(arm_stub_none, NULL, 0);
4821
4822 #define DEF_STUB(x) \
4823 do \
4824 { \
4825 size_t array_size \
4826 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4827 Stub_type type = arm_stub_##x; \
4828 this->stub_templates_[type] = \
4829 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4830 } \
4831 while (0);
4832
4833 DEF_STUBS
4834 #undef DEF_STUB
4835 }
4836
4837 // Stub_table methods.
4838
4839 // Removel all Cortex-A8 stub.
4840
4841 template<bool big_endian>
4842 void
4843 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4844 {
4845 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4846 p != this->cortex_a8_stubs_.end();
4847 ++p)
4848 delete p->second;
4849 this->cortex_a8_stubs_.clear();
4850 }
4851
4852 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4853
4854 template<bool big_endian>
4855 void
4856 Stub_table<big_endian>::relocate_stub(
4857 Stub* stub,
4858 const Relocate_info<32, big_endian>* relinfo,
4859 Target_arm<big_endian>* arm_target,
4860 Output_section* output_section,
4861 unsigned char* view,
4862 Arm_address address,
4863 section_size_type view_size)
4864 {
4865 const Stub_template* stub_template = stub->stub_template();
4866 if (stub_template->reloc_count() != 0)
4867 {
4868 // Adjust view to cover the stub only.
4869 section_size_type offset = stub->offset();
4870 section_size_type stub_size = stub_template->size();
4871 gold_assert(offset + stub_size <= view_size);
4872
4873 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4874 address + offset, stub_size);
4875 }
4876 }
4877
4878 // Relocate all stubs in this stub table.
4879
4880 template<bool big_endian>
4881 void
4882 Stub_table<big_endian>::relocate_stubs(
4883 const Relocate_info<32, big_endian>* relinfo,
4884 Target_arm<big_endian>* arm_target,
4885 Output_section* output_section,
4886 unsigned char* view,
4887 Arm_address address,
4888 section_size_type view_size)
4889 {
4890 // If we are passed a view bigger than the stub table's. we need to
4891 // adjust the view.
4892 gold_assert(address == this->address()
4893 && (view_size
4894 == static_cast<section_size_type>(this->data_size())));
4895
4896 // Relocate all relocation stubs.
4897 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4898 p != this->reloc_stubs_.end();
4899 ++p)
4900 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4901 address, view_size);
4902
4903 // Relocate all Cortex-A8 stubs.
4904 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4905 p != this->cortex_a8_stubs_.end();
4906 ++p)
4907 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4908 address, view_size);
4909
4910 // Relocate all ARM V4BX stubs.
4911 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4912 p != this->arm_v4bx_stubs_.end();
4913 ++p)
4914 {
4915 if (*p != NULL)
4916 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4917 address, view_size);
4918 }
4919 }
4920
4921 // Write out the stubs to file.
4922
4923 template<bool big_endian>
4924 void
4925 Stub_table<big_endian>::do_write(Output_file* of)
4926 {
4927 off_t offset = this->offset();
4928 const section_size_type oview_size =
4929 convert_to_section_size_type(this->data_size());
4930 unsigned char* const oview = of->get_output_view(offset, oview_size);
4931
4932 // Write relocation stubs.
4933 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4934 p != this->reloc_stubs_.end();
4935 ++p)
4936 {
4937 Reloc_stub* stub = p->second;
4938 Arm_address address = this->address() + stub->offset();
4939 gold_assert(address
4940 == align_address(address,
4941 stub->stub_template()->alignment()));
4942 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4943 big_endian);
4944 }
4945
4946 // Write Cortex-A8 stubs.
4947 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4948 p != this->cortex_a8_stubs_.end();
4949 ++p)
4950 {
4951 Cortex_a8_stub* stub = p->second;
4952 Arm_address address = this->address() + stub->offset();
4953 gold_assert(address
4954 == align_address(address,
4955 stub->stub_template()->alignment()));
4956 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4957 big_endian);
4958 }
4959
4960 // Write ARM V4BX relocation stubs.
4961 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4962 p != this->arm_v4bx_stubs_.end();
4963 ++p)
4964 {
4965 if (*p == NULL)
4966 continue;
4967
4968 Arm_address address = this->address() + (*p)->offset();
4969 gold_assert(address
4970 == align_address(address,
4971 (*p)->stub_template()->alignment()));
4972 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4973 big_endian);
4974 }
4975
4976 of->write_output_view(this->offset(), oview_size, oview);
4977 }
4978
4979 // Update the data size and address alignment of the stub table at the end
4980 // of a relaxation pass. Return true if either the data size or the
4981 // alignment changed in this relaxation pass.
4982
4983 template<bool big_endian>
4984 bool
4985 Stub_table<big_endian>::update_data_size_and_addralign()
4986 {
4987 // Go over all stubs in table to compute data size and address alignment.
4988 off_t size = this->reloc_stubs_size_;
4989 unsigned addralign = this->reloc_stubs_addralign_;
4990
4991 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4992 p != this->cortex_a8_stubs_.end();
4993 ++p)
4994 {
4995 const Stub_template* stub_template = p->second->stub_template();
4996 addralign = std::max(addralign, stub_template->alignment());
4997 size = (align_address(size, stub_template->alignment())
4998 + stub_template->size());
4999 }
5000
5001 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5002 p != this->arm_v4bx_stubs_.end();
5003 ++p)
5004 {
5005 if (*p == NULL)
5006 continue;
5007
5008 const Stub_template* stub_template = (*p)->stub_template();
5009 addralign = std::max(addralign, stub_template->alignment());
5010 size = (align_address(size, stub_template->alignment())
5011 + stub_template->size());
5012 }
5013
5014 // Check if either data size or alignment changed in this pass.
5015 // Update prev_data_size_ and prev_addralign_. These will be used
5016 // as the current data size and address alignment for the next pass.
5017 bool changed = size != this->prev_data_size_;
5018 this->prev_data_size_ = size;
5019
5020 if (addralign != this->prev_addralign_)
5021 changed = true;
5022 this->prev_addralign_ = addralign;
5023
5024 return changed;
5025 }
5026
5027 // Finalize the stubs. This sets the offsets of the stubs within the stub
5028 // table. It also marks all input sections needing Cortex-A8 workaround.
5029
5030 template<bool big_endian>
5031 void
5032 Stub_table<big_endian>::finalize_stubs()
5033 {
5034 off_t off = this->reloc_stubs_size_;
5035 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5036 p != this->cortex_a8_stubs_.end();
5037 ++p)
5038 {
5039 Cortex_a8_stub* stub = p->second;
5040 const Stub_template* stub_template = stub->stub_template();
5041 uint64_t stub_addralign = stub_template->alignment();
5042 off = align_address(off, stub_addralign);
5043 stub->set_offset(off);
5044 off += stub_template->size();
5045
5046 // Mark input section so that we can determine later if a code section
5047 // needs the Cortex-A8 workaround quickly.
5048 Arm_relobj<big_endian>* arm_relobj =
5049 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5050 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5051 }
5052
5053 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5054 p != this->arm_v4bx_stubs_.end();
5055 ++p)
5056 {
5057 if (*p == NULL)
5058 continue;
5059
5060 const Stub_template* stub_template = (*p)->stub_template();
5061 uint64_t stub_addralign = stub_template->alignment();
5062 off = align_address(off, stub_addralign);
5063 (*p)->set_offset(off);
5064 off += stub_template->size();
5065 }
5066
5067 gold_assert(off <= this->prev_data_size_);
5068 }
5069
5070 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5071 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5072 // of the address range seen by the linker.
5073
5074 template<bool big_endian>
5075 void
5076 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5077 Target_arm<big_endian>* arm_target,
5078 unsigned char* view,
5079 Arm_address view_address,
5080 section_size_type view_size)
5081 {
5082 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5083 for (Cortex_a8_stub_list::const_iterator p =
5084 this->cortex_a8_stubs_.lower_bound(view_address);
5085 ((p != this->cortex_a8_stubs_.end())
5086 && (p->first < (view_address + view_size)));
5087 ++p)
5088 {
5089 // We do not store the THUMB bit in the LSB of either the branch address
5090 // or the stub offset. There is no need to strip the LSB.
5091 Arm_address branch_address = p->first;
5092 const Cortex_a8_stub* stub = p->second;
5093 Arm_address stub_address = this->address() + stub->offset();
5094
5095 // Offset of the branch instruction relative to this view.
5096 section_size_type offset =
5097 convert_to_section_size_type(branch_address - view_address);
5098 gold_assert((offset + 4) <= view_size);
5099
5100 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5101 view + offset, branch_address);
5102 }
5103 }
5104
5105 // Arm_input_section methods.
5106
5107 // Initialize an Arm_input_section.
5108
5109 template<bool big_endian>
5110 void
5111 Arm_input_section<big_endian>::init()
5112 {
5113 Relobj* relobj = this->relobj();
5114 unsigned int shndx = this->shndx();
5115
5116 // We have to cache original size, alignment and contents to avoid locking
5117 // the original file.
5118 this->original_addralign_ =
5119 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5120
5121 // This is not efficient but we expect only a small number of relaxed
5122 // input sections for stubs.
5123 section_size_type section_size;
5124 const unsigned char* section_contents =
5125 relobj->section_contents(shndx, &section_size, false);
5126 this->original_size_ =
5127 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5128
5129 gold_assert(this->original_contents_ == NULL);
5130 this->original_contents_ = new unsigned char[section_size];
5131 memcpy(this->original_contents_, section_contents, section_size);
5132
5133 // We want to make this look like the original input section after
5134 // output sections are finalized.
5135 Output_section* os = relobj->output_section(shndx);
5136 off_t offset = relobj->output_section_offset(shndx);
5137 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5138 this->set_address(os->address() + offset);
5139 this->set_file_offset(os->offset() + offset);
5140
5141 this->set_current_data_size(this->original_size_);
5142 this->finalize_data_size();
5143 }
5144
5145 template<bool big_endian>
5146 void
5147 Arm_input_section<big_endian>::do_write(Output_file* of)
5148 {
5149 // We have to write out the original section content.
5150 gold_assert(this->original_contents_ != NULL);
5151 of->write(this->offset(), this->original_contents_,
5152 this->original_size_);
5153
5154 // If this owns a stub table and it is not empty, write it.
5155 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5156 this->stub_table_->write(of);
5157 }
5158
5159 // Finalize data size.
5160
5161 template<bool big_endian>
5162 void
5163 Arm_input_section<big_endian>::set_final_data_size()
5164 {
5165 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5166
5167 if (this->is_stub_table_owner())
5168 {
5169 this->stub_table_->finalize_data_size();
5170 off = align_address(off, this->stub_table_->addralign());
5171 off += this->stub_table_->data_size();
5172 }
5173 this->set_data_size(off);
5174 }
5175
5176 // Reset address and file offset.
5177
5178 template<bool big_endian>
5179 void
5180 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5181 {
5182 // Size of the original input section contents.
5183 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5184
5185 // If this is a stub table owner, account for the stub table size.
5186 if (this->is_stub_table_owner())
5187 {
5188 Stub_table<big_endian>* stub_table = this->stub_table_;
5189
5190 // Reset the stub table's address and file offset. The
5191 // current data size for child will be updated after that.
5192 stub_table_->reset_address_and_file_offset();
5193 off = align_address(off, stub_table_->addralign());
5194 off += stub_table->current_data_size();
5195 }
5196
5197 this->set_current_data_size(off);
5198 }
5199
5200 // Arm_exidx_cantunwind methods.
5201
5202 // Write this to Output file OF for a fixed endianness.
5203
5204 template<bool big_endian>
5205 void
5206 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5207 {
5208 off_t offset = this->offset();
5209 const section_size_type oview_size = 8;
5210 unsigned char* const oview = of->get_output_view(offset, oview_size);
5211
5212 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5213 Valtype* wv = reinterpret_cast<Valtype*>(oview);
5214
5215 Output_section* os = this->relobj_->output_section(this->shndx_);
5216 gold_assert(os != NULL);
5217
5218 Arm_relobj<big_endian>* arm_relobj =
5219 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5220 Arm_address output_offset =
5221 arm_relobj->get_output_section_offset(this->shndx_);
5222 Arm_address section_start;
5223 section_size_type section_size;
5224
5225 // Find out the end of the text section referred by this.
5226 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5227 {
5228 section_start = os->address() + output_offset;
5229 const Arm_exidx_input_section* exidx_input_section =
5230 arm_relobj->exidx_input_section_by_link(this->shndx_);
5231 gold_assert(exidx_input_section != NULL);
5232 section_size =
5233 convert_to_section_size_type(exidx_input_section->text_size());
5234 }
5235 else
5236 {
5237 // Currently this only happens for a relaxed section.
5238 const Output_relaxed_input_section* poris =
5239 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5240 gold_assert(poris != NULL);
5241 section_start = poris->address();
5242 section_size = convert_to_section_size_type(poris->data_size());
5243 }
5244
5245 // We always append this to the end of an EXIDX section.
5246 Arm_address output_address = section_start + section_size;
5247
5248 // Write out the entry. The first word either points to the beginning
5249 // or after the end of a text section. The second word is the special
5250 // EXIDX_CANTUNWIND value.
5251 uint32_t prel31_offset = output_address - this->address();
5252 if (utils::has_overflow<31>(offset))
5253 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5254 elfcpp::Swap<32, big_endian>::writeval(wv, prel31_offset & 0x7fffffffU);
5255 elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
5256
5257 of->write_output_view(this->offset(), oview_size, oview);
5258 }
5259
5260 // Arm_exidx_merged_section methods.
5261
5262 // Constructor for Arm_exidx_merged_section.
5263 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5264 // SECTION_OFFSET_MAP points to a section offset map describing how
5265 // parts of the input section are mapped to output. DELETED_BYTES is
5266 // the number of bytes deleted from the EXIDX input section.
5267
5268 Arm_exidx_merged_section::Arm_exidx_merged_section(
5269 const Arm_exidx_input_section& exidx_input_section,
5270 const Arm_exidx_section_offset_map& section_offset_map,
5271 uint32_t deleted_bytes)
5272 : Output_relaxed_input_section(exidx_input_section.relobj(),
5273 exidx_input_section.shndx(),
5274 exidx_input_section.addralign()),
5275 exidx_input_section_(exidx_input_section),
5276 section_offset_map_(section_offset_map)
5277 {
5278 // If we retain or discard the whole EXIDX input section, we would
5279 // not be here.
5280 gold_assert(deleted_bytes != 0
5281 && deleted_bytes != this->exidx_input_section_.size());
5282
5283 // Fix size here so that we do not need to implement set_final_data_size.
5284 uint32_t size = exidx_input_section.size() - deleted_bytes;
5285 this->set_data_size(size);
5286 this->fix_data_size();
5287
5288 // Allocate buffer for section contents and build contents.
5289 this->section_contents_ = new unsigned char[size];
5290 }
5291
5292 // Build the contents of a merged EXIDX output section.
5293
5294 void
5295 Arm_exidx_merged_section::build_contents(
5296 const unsigned char* original_contents,
5297 section_size_type original_size)
5298 {
5299 // Go over spans of input offsets and write only those that are not
5300 // discarded.
5301 section_offset_type in_start = 0;
5302 section_offset_type out_start = 0;
5303 section_offset_type in_max =
5304 convert_types<section_offset_type>(original_size);
5305 section_offset_type out_max =
5306 convert_types<section_offset_type>(this->data_size());
5307 for (Arm_exidx_section_offset_map::const_iterator p =
5308 this->section_offset_map_.begin();
5309 p != this->section_offset_map_.end();
5310 ++p)
5311 {
5312 section_offset_type in_end = p->first;
5313 gold_assert(in_end >= in_start);
5314 section_offset_type out_end = p->second;
5315 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5316 if (out_end != -1)
5317 {
5318 size_t out_chunk_size =
5319 convert_types<size_t>(out_end - out_start + 1);
5320
5321 gold_assert(out_chunk_size == in_chunk_size
5322 && in_end < in_max && out_end < out_max);
5323
5324 memcpy(this->section_contents_ + out_start,
5325 original_contents + in_start,
5326 out_chunk_size);
5327 out_start += out_chunk_size;
5328 }
5329 in_start += in_chunk_size;
5330 }
5331 }
5332
5333 // Given an input OBJECT, an input section index SHNDX within that
5334 // object, and an OFFSET relative to the start of that input
5335 // section, return whether or not the corresponding offset within
5336 // the output section is known. If this function returns true, it
5337 // sets *POUTPUT to the output offset. The value -1 indicates that
5338 // this input offset is being discarded.
5339
5340 bool
5341 Arm_exidx_merged_section::do_output_offset(
5342 const Relobj* relobj,
5343 unsigned int shndx,
5344 section_offset_type offset,
5345 section_offset_type* poutput) const
5346 {
5347 // We only handle offsets for the original EXIDX input section.
5348 if (relobj != this->exidx_input_section_.relobj()
5349 || shndx != this->exidx_input_section_.shndx())
5350 return false;
5351
5352 section_offset_type section_size =
5353 convert_types<section_offset_type>(this->exidx_input_section_.size());
5354 if (offset < 0 || offset >= section_size)
5355 // Input offset is out of valid range.
5356 *poutput = -1;
5357 else
5358 {
5359 // We need to look up the section offset map to determine the output
5360 // offset. Find the reference point in map that is first offset
5361 // bigger than or equal to this offset.
5362 Arm_exidx_section_offset_map::const_iterator p =
5363 this->section_offset_map_.lower_bound(offset);
5364
5365 // The section offset maps are build such that this should not happen if
5366 // input offset is in the valid range.
5367 gold_assert(p != this->section_offset_map_.end());
5368
5369 // We need to check if this is dropped.
5370 section_offset_type ref = p->first;
5371 section_offset_type mapped_ref = p->second;
5372
5373 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5374 // Offset is present in output.
5375 *poutput = mapped_ref + (offset - ref);
5376 else
5377 // Offset is discarded owing to EXIDX entry merging.
5378 *poutput = -1;
5379 }
5380
5381 return true;
5382 }
5383
5384 // Write this to output file OF.
5385
5386 void
5387 Arm_exidx_merged_section::do_write(Output_file* of)
5388 {
5389 off_t offset = this->offset();
5390 const section_size_type oview_size = this->data_size();
5391 unsigned char* const oview = of->get_output_view(offset, oview_size);
5392
5393 Output_section* os = this->relobj()->output_section(this->shndx());
5394 gold_assert(os != NULL);
5395
5396 memcpy(oview, this->section_contents_, oview_size);
5397 of->write_output_view(this->offset(), oview_size, oview);
5398 }
5399
5400 // Arm_exidx_fixup methods.
5401
5402 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5403 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5404 // points to the end of the last seen EXIDX section.
5405
5406 void
5407 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5408 {
5409 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5410 && this->last_input_section_ != NULL)
5411 {
5412 Relobj* relobj = this->last_input_section_->relobj();
5413 unsigned int text_shndx = this->last_input_section_->link();
5414 Arm_exidx_cantunwind* cantunwind =
5415 new Arm_exidx_cantunwind(relobj, text_shndx);
5416 this->exidx_output_section_->add_output_section_data(cantunwind);
5417 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5418 }
5419 }
5420
5421 // Process an EXIDX section entry in input. Return whether this entry
5422 // can be deleted in the output. SECOND_WORD in the second word of the
5423 // EXIDX entry.
5424
5425 bool
5426 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5427 {
5428 bool delete_entry;
5429 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5430 {
5431 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5432 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5433 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5434 }
5435 else if ((second_word & 0x80000000) != 0)
5436 {
5437 // Inlined unwinding data. Merge if equal to previous.
5438 delete_entry = (merge_exidx_entries_
5439 && this->last_unwind_type_ == UT_INLINED_ENTRY
5440 && this->last_inlined_entry_ == second_word);
5441 this->last_unwind_type_ = UT_INLINED_ENTRY;
5442 this->last_inlined_entry_ = second_word;
5443 }
5444 else
5445 {
5446 // Normal table entry. In theory we could merge these too,
5447 // but duplicate entries are likely to be much less common.
5448 delete_entry = false;
5449 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5450 }
5451 return delete_entry;
5452 }
5453
5454 // Update the current section offset map during EXIDX section fix-up.
5455 // If there is no map, create one. INPUT_OFFSET is the offset of a
5456 // reference point, DELETED_BYTES is the number of deleted by in the
5457 // section so far. If DELETE_ENTRY is true, the reference point and
5458 // all offsets after the previous reference point are discarded.
5459
5460 void
5461 Arm_exidx_fixup::update_offset_map(
5462 section_offset_type input_offset,
5463 section_size_type deleted_bytes,
5464 bool delete_entry)
5465 {
5466 if (this->section_offset_map_ == NULL)
5467 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5468 section_offset_type output_offset;
5469 if (delete_entry)
5470 output_offset = Arm_exidx_input_section::invalid_offset;
5471 else
5472 output_offset = input_offset - deleted_bytes;
5473 (*this->section_offset_map_)[input_offset] = output_offset;
5474 }
5475
5476 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5477 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5478 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5479 // If some entries are merged, also store a pointer to a newly created
5480 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5481 // owns the map and is responsible for releasing it after use.
5482
5483 template<bool big_endian>
5484 uint32_t
5485 Arm_exidx_fixup::process_exidx_section(
5486 const Arm_exidx_input_section* exidx_input_section,
5487 const unsigned char* section_contents,
5488 section_size_type section_size,
5489 Arm_exidx_section_offset_map** psection_offset_map)
5490 {
5491 Relobj* relobj = exidx_input_section->relobj();
5492 unsigned shndx = exidx_input_section->shndx();
5493
5494 if ((section_size % 8) != 0)
5495 {
5496 // Something is wrong with this section. Better not touch it.
5497 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5498 relobj->name().c_str(), shndx);
5499 this->last_input_section_ = exidx_input_section;
5500 this->last_unwind_type_ = UT_NONE;
5501 return 0;
5502 }
5503
5504 uint32_t deleted_bytes = 0;
5505 bool prev_delete_entry = false;
5506 gold_assert(this->section_offset_map_ == NULL);
5507
5508 for (section_size_type i = 0; i < section_size; i += 8)
5509 {
5510 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5511 const Valtype* wv =
5512 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5513 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5514
5515 bool delete_entry = this->process_exidx_entry(second_word);
5516
5517 // Entry deletion causes changes in output offsets. We use a std::map
5518 // to record these. And entry (x, y) means input offset x
5519 // is mapped to output offset y. If y is invalid_offset, then x is
5520 // dropped in the output. Because of the way std::map::lower_bound
5521 // works, we record the last offset in a region w.r.t to keeping or
5522 // dropping. If there is no entry (x0, y0) for an input offset x0,
5523 // the output offset y0 of it is determined by the output offset y1 of
5524 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5525 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Othewise, y1
5526 // y0 is also -1.
5527 if (delete_entry != prev_delete_entry && i != 0)
5528 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5529
5530 // Update total deleted bytes for this entry.
5531 if (delete_entry)
5532 deleted_bytes += 8;
5533
5534 prev_delete_entry = delete_entry;
5535 }
5536
5537 // If section offset map is not NULL, make an entry for the end of
5538 // section.
5539 if (this->section_offset_map_ != NULL)
5540 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5541
5542 *psection_offset_map = this->section_offset_map_;
5543 this->section_offset_map_ = NULL;
5544 this->last_input_section_ = exidx_input_section;
5545
5546 // Set the first output text section so that we can link the EXIDX output
5547 // section to it. Ignore any EXIDX input section that is completely merged.
5548 if (this->first_output_text_section_ == NULL
5549 && deleted_bytes != section_size)
5550 {
5551 unsigned int link = exidx_input_section->link();
5552 Output_section* os = relobj->output_section(link);
5553 gold_assert(os != NULL);
5554 this->first_output_text_section_ = os;
5555 }
5556
5557 return deleted_bytes;
5558 }
5559
5560 // Arm_output_section methods.
5561
5562 // Create a stub group for input sections from BEGIN to END. OWNER
5563 // points to the input section to be the owner a new stub table.
5564
5565 template<bool big_endian>
5566 void
5567 Arm_output_section<big_endian>::create_stub_group(
5568 Input_section_list::const_iterator begin,
5569 Input_section_list::const_iterator end,
5570 Input_section_list::const_iterator owner,
5571 Target_arm<big_endian>* target,
5572 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5573 const Task* task)
5574 {
5575 // We use a different kind of relaxed section in an EXIDX section.
5576 // The static casting from Output_relaxed_input_section to
5577 // Arm_input_section is invalid in an EXIDX section. We are okay
5578 // because we should not be calling this for an EXIDX section.
5579 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5580
5581 // Currently we convert ordinary input sections into relaxed sections only
5582 // at this point but we may want to support creating relaxed input section
5583 // very early. So we check here to see if owner is already a relaxed
5584 // section.
5585
5586 Arm_input_section<big_endian>* arm_input_section;
5587 if (owner->is_relaxed_input_section())
5588 {
5589 arm_input_section =
5590 Arm_input_section<big_endian>::as_arm_input_section(
5591 owner->relaxed_input_section());
5592 }
5593 else
5594 {
5595 gold_assert(owner->is_input_section());
5596 // Create a new relaxed input section. We need to lock the original
5597 // file.
5598 Task_lock_obj<Object> tl(task, owner->relobj());
5599 arm_input_section =
5600 target->new_arm_input_section(owner->relobj(), owner->shndx());
5601 new_relaxed_sections->push_back(arm_input_section);
5602 }
5603
5604 // Create a stub table.
5605 Stub_table<big_endian>* stub_table =
5606 target->new_stub_table(arm_input_section);
5607
5608 arm_input_section->set_stub_table(stub_table);
5609
5610 Input_section_list::const_iterator p = begin;
5611 Input_section_list::const_iterator prev_p;
5612
5613 // Look for input sections or relaxed input sections in [begin ... end].
5614 do
5615 {
5616 if (p->is_input_section() || p->is_relaxed_input_section())
5617 {
5618 // The stub table information for input sections live
5619 // in their objects.
5620 Arm_relobj<big_endian>* arm_relobj =
5621 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5622 arm_relobj->set_stub_table(p->shndx(), stub_table);
5623 }
5624 prev_p = p++;
5625 }
5626 while (prev_p != end);
5627 }
5628
5629 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5630 // of stub groups. We grow a stub group by adding input section until the
5631 // size is just below GROUP_SIZE. The last input section will be converted
5632 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5633 // input section after the stub table, effectively double the group size.
5634 //
5635 // This is similar to the group_sections() function in elf32-arm.c but is
5636 // implemented differently.
5637
5638 template<bool big_endian>
5639 void
5640 Arm_output_section<big_endian>::group_sections(
5641 section_size_type group_size,
5642 bool stubs_always_after_branch,
5643 Target_arm<big_endian>* target,
5644 const Task* task)
5645 {
5646 // We only care about sections containing code.
5647 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5648 return;
5649
5650 // States for grouping.
5651 typedef enum
5652 {
5653 // No group is being built.
5654 NO_GROUP,
5655 // A group is being built but the stub table is not found yet.
5656 // We keep group a stub group until the size is just under GROUP_SIZE.
5657 // The last input section in the group will be used as the stub table.
5658 FINDING_STUB_SECTION,
5659 // A group is being built and we have already found a stub table.
5660 // We enter this state to grow a stub group by adding input section
5661 // after the stub table. This effectively doubles the group size.
5662 HAS_STUB_SECTION
5663 } State;
5664
5665 // Any newly created relaxed sections are stored here.
5666 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5667
5668 State state = NO_GROUP;
5669 section_size_type off = 0;
5670 section_size_type group_begin_offset = 0;
5671 section_size_type group_end_offset = 0;
5672 section_size_type stub_table_end_offset = 0;
5673 Input_section_list::const_iterator group_begin =
5674 this->input_sections().end();
5675 Input_section_list::const_iterator stub_table =
5676 this->input_sections().end();
5677 Input_section_list::const_iterator group_end = this->input_sections().end();
5678 for (Input_section_list::const_iterator p = this->input_sections().begin();
5679 p != this->input_sections().end();
5680 ++p)
5681 {
5682 section_size_type section_begin_offset =
5683 align_address(off, p->addralign());
5684 section_size_type section_end_offset =
5685 section_begin_offset + p->data_size();
5686
5687 // Check to see if we should group the previously seens sections.
5688 switch (state)
5689 {
5690 case NO_GROUP:
5691 break;
5692
5693 case FINDING_STUB_SECTION:
5694 // Adding this section makes the group larger than GROUP_SIZE.
5695 if (section_end_offset - group_begin_offset >= group_size)
5696 {
5697 if (stubs_always_after_branch)
5698 {
5699 gold_assert(group_end != this->input_sections().end());
5700 this->create_stub_group(group_begin, group_end, group_end,
5701 target, &new_relaxed_sections,
5702 task);
5703 state = NO_GROUP;
5704 }
5705 else
5706 {
5707 // But wait, there's more! Input sections up to
5708 // stub_group_size bytes after the stub table can be
5709 // handled by it too.
5710 state = HAS_STUB_SECTION;
5711 stub_table = group_end;
5712 stub_table_end_offset = group_end_offset;
5713 }
5714 }
5715 break;
5716
5717 case HAS_STUB_SECTION:
5718 // Adding this section makes the post stub-section group larger
5719 // than GROUP_SIZE.
5720 if (section_end_offset - stub_table_end_offset >= group_size)
5721 {
5722 gold_assert(group_end != this->input_sections().end());
5723 this->create_stub_group(group_begin, group_end, stub_table,
5724 target, &new_relaxed_sections, task);
5725 state = NO_GROUP;
5726 }
5727 break;
5728
5729 default:
5730 gold_unreachable();
5731 }
5732
5733 // If we see an input section and currently there is no group, start
5734 // a new one. Skip any empty sections. We look at the data size
5735 // instead of calling p->relobj()->section_size() to avoid locking.
5736 if ((p->is_input_section() || p->is_relaxed_input_section())
5737 && (p->data_size() != 0))
5738 {
5739 if (state == NO_GROUP)
5740 {
5741 state = FINDING_STUB_SECTION;
5742 group_begin = p;
5743 group_begin_offset = section_begin_offset;
5744 }
5745
5746 // Keep track of the last input section seen.
5747 group_end = p;
5748 group_end_offset = section_end_offset;
5749 }
5750
5751 off = section_end_offset;
5752 }
5753
5754 // Create a stub group for any ungrouped sections.
5755 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5756 {
5757 gold_assert(group_end != this->input_sections().end());
5758 this->create_stub_group(group_begin, group_end,
5759 (state == FINDING_STUB_SECTION
5760 ? group_end
5761 : stub_table),
5762 target, &new_relaxed_sections, task);
5763 }
5764
5765 // Convert input section into relaxed input section in a batch.
5766 if (!new_relaxed_sections.empty())
5767 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5768
5769 // Update the section offsets
5770 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5771 {
5772 Arm_relobj<big_endian>* arm_relobj =
5773 Arm_relobj<big_endian>::as_arm_relobj(
5774 new_relaxed_sections[i]->relobj());
5775 unsigned int shndx = new_relaxed_sections[i]->shndx();
5776 // Tell Arm_relobj that this input section is converted.
5777 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5778 }
5779 }
5780
5781 // Append non empty text sections in this to LIST in ascending
5782 // order of their position in this.
5783
5784 template<bool big_endian>
5785 void
5786 Arm_output_section<big_endian>::append_text_sections_to_list(
5787 Text_section_list* list)
5788 {
5789 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5790
5791 for (Input_section_list::const_iterator p = this->input_sections().begin();
5792 p != this->input_sections().end();
5793 ++p)
5794 {
5795 // We only care about plain or relaxed input sections. We also
5796 // ignore any merged sections.
5797 if ((p->is_input_section() || p->is_relaxed_input_section())
5798 && p->data_size() != 0)
5799 list->push_back(Text_section_list::value_type(p->relobj(),
5800 p->shndx()));
5801 }
5802 }
5803
5804 template<bool big_endian>
5805 void
5806 Arm_output_section<big_endian>::fix_exidx_coverage(
5807 Layout* layout,
5808 const Text_section_list& sorted_text_sections,
5809 Symbol_table* symtab,
5810 bool merge_exidx_entries,
5811 const Task* task)
5812 {
5813 // We should only do this for the EXIDX output section.
5814 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5815
5816 // We don't want the relaxation loop to undo these changes, so we discard
5817 // the current saved states and take another one after the fix-up.
5818 this->discard_states();
5819
5820 // Remove all input sections.
5821 uint64_t address = this->address();
5822 typedef std::list<Output_section::Input_section> Input_section_list;
5823 Input_section_list input_sections;
5824 this->reset_address_and_file_offset();
5825 this->get_input_sections(address, std::string(""), &input_sections);
5826
5827 if (!this->input_sections().empty())
5828 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5829
5830 // Go through all the known input sections and record them.
5831 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5832 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5833 Section_id_hash> Text_to_exidx_map;
5834 Text_to_exidx_map text_to_exidx_map;
5835 for (Input_section_list::const_iterator p = input_sections.begin();
5836 p != input_sections.end();
5837 ++p)
5838 {
5839 // This should never happen. At this point, we should only see
5840 // plain EXIDX input sections.
5841 gold_assert(!p->is_relaxed_input_section());
5842 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5843 }
5844
5845 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5846
5847 // Go over the sorted text sections.
5848 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5849 Section_id_set processed_input_sections;
5850 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5851 p != sorted_text_sections.end();
5852 ++p)
5853 {
5854 Relobj* relobj = p->first;
5855 unsigned int shndx = p->second;
5856
5857 Arm_relobj<big_endian>* arm_relobj =
5858 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5859 const Arm_exidx_input_section* exidx_input_section =
5860 arm_relobj->exidx_input_section_by_link(shndx);
5861
5862 // If this text section has no EXIDX section or if the EXIDX section
5863 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5864 // of the last seen EXIDX section.
5865 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5866 {
5867 exidx_fixup.add_exidx_cantunwind_as_needed();
5868 continue;
5869 }
5870
5871 Relobj* exidx_relobj = exidx_input_section->relobj();
5872 unsigned int exidx_shndx = exidx_input_section->shndx();
5873 Section_id sid(exidx_relobj, exidx_shndx);
5874 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5875 if (iter == text_to_exidx_map.end())
5876 {
5877 // This is odd. We have not seen this EXIDX input section before.
5878 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5879 // issue a warning instead. We assume the user knows what he
5880 // or she is doing. Otherwise, this is an error.
5881 if (layout->script_options()->saw_sections_clause())
5882 gold_warning(_("unwinding may not work because EXIDX input section"
5883 " %u of %s is not in EXIDX output section"),
5884 exidx_shndx, exidx_relobj->name().c_str());
5885 else
5886 gold_error(_("unwinding may not work because EXIDX input section"
5887 " %u of %s is not in EXIDX output section"),
5888 exidx_shndx, exidx_relobj->name().c_str());
5889
5890 exidx_fixup.add_exidx_cantunwind_as_needed();
5891 continue;
5892 }
5893
5894 // We need to access the contents of the EXIDX section, lock the
5895 // object here.
5896 Task_lock_obj<Object> tl(task, exidx_relobj);
5897 section_size_type exidx_size;
5898 const unsigned char* exidx_contents =
5899 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5900
5901 // Fix up coverage and append input section to output data list.
5902 Arm_exidx_section_offset_map* section_offset_map = NULL;
5903 uint32_t deleted_bytes =
5904 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5905 exidx_contents,
5906 exidx_size,
5907 &section_offset_map);
5908
5909 if (deleted_bytes == exidx_input_section->size())
5910 {
5911 // The whole EXIDX section got merged. Remove it from output.
5912 gold_assert(section_offset_map == NULL);
5913 exidx_relobj->set_output_section(exidx_shndx, NULL);
5914
5915 // All local symbols defined in this input section will be dropped.
5916 // We need to adjust output local symbol count.
5917 arm_relobj->set_output_local_symbol_count_needs_update();
5918 }
5919 else if (deleted_bytes > 0)
5920 {
5921 // Some entries are merged. We need to convert this EXIDX input
5922 // section into a relaxed section.
5923 gold_assert(section_offset_map != NULL);
5924
5925 Arm_exidx_merged_section* merged_section =
5926 new Arm_exidx_merged_section(*exidx_input_section,
5927 *section_offset_map, deleted_bytes);
5928 merged_section->build_contents(exidx_contents, exidx_size);
5929
5930 const std::string secname = exidx_relobj->section_name(exidx_shndx);
5931 this->add_relaxed_input_section(layout, merged_section, secname);
5932 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5933
5934 // All local symbols defined in discarded portions of this input
5935 // section will be dropped. We need to adjust output local symbol
5936 // count.
5937 arm_relobj->set_output_local_symbol_count_needs_update();
5938 }
5939 else
5940 {
5941 // Just add back the EXIDX input section.
5942 gold_assert(section_offset_map == NULL);
5943 const Output_section::Input_section* pis = iter->second;
5944 gold_assert(pis->is_input_section());
5945 this->add_script_input_section(*pis);
5946 }
5947
5948 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5949 }
5950
5951 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5952 exidx_fixup.add_exidx_cantunwind_as_needed();
5953
5954 // Remove any known EXIDX input sections that are not processed.
5955 for (Input_section_list::const_iterator p = input_sections.begin();
5956 p != input_sections.end();
5957 ++p)
5958 {
5959 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5960 == processed_input_sections.end())
5961 {
5962 // We discard a known EXIDX section because its linked
5963 // text section has been folded by ICF. We also discard an
5964 // EXIDX section with error, the output does not matter in this
5965 // case. We do this to avoid triggering asserts.
5966 Arm_relobj<big_endian>* arm_relobj =
5967 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5968 const Arm_exidx_input_section* exidx_input_section =
5969 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5970 gold_assert(exidx_input_section != NULL);
5971 if (!exidx_input_section->has_errors())
5972 {
5973 unsigned int text_shndx = exidx_input_section->link();
5974 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5975 }
5976
5977 // Remove this from link. We also need to recount the
5978 // local symbols.
5979 p->relobj()->set_output_section(p->shndx(), NULL);
5980 arm_relobj->set_output_local_symbol_count_needs_update();
5981 }
5982 }
5983
5984 // Link exidx output section to the first seen output section and
5985 // set correct entry size.
5986 this->set_link_section(exidx_fixup.first_output_text_section());
5987 this->set_entsize(8);
5988
5989 // Make changes permanent.
5990 this->save_states();
5991 this->set_section_offsets_need_adjustment();
5992 }
5993
5994 // Link EXIDX output sections to text output sections.
5995
5996 template<bool big_endian>
5997 void
5998 Arm_output_section<big_endian>::set_exidx_section_link()
5999 {
6000 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6001 if (!this->input_sections().empty())
6002 {
6003 Input_section_list::const_iterator p = this->input_sections().begin();
6004 Arm_relobj<big_endian>* arm_relobj =
6005 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6006 unsigned exidx_shndx = p->shndx();
6007 const Arm_exidx_input_section* exidx_input_section =
6008 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6009 gold_assert(exidx_input_section != NULL);
6010 unsigned int text_shndx = exidx_input_section->link();
6011 Output_section* os = arm_relobj->output_section(text_shndx);
6012 this->set_link_section(os);
6013 }
6014 }
6015
6016 // Arm_relobj methods.
6017
6018 // Determine if an input section is scannable for stub processing. SHDR is
6019 // the header of the section and SHNDX is the section index. OS is the output
6020 // section for the input section and SYMTAB is the global symbol table used to
6021 // look up ICF information.
6022
6023 template<bool big_endian>
6024 bool
6025 Arm_relobj<big_endian>::section_is_scannable(
6026 const elfcpp::Shdr<32, big_endian>& shdr,
6027 unsigned int shndx,
6028 const Output_section* os,
6029 const Symbol_table* symtab)
6030 {
6031 // Skip any empty sections, unallocated sections or sections whose
6032 // type are not SHT_PROGBITS.
6033 if (shdr.get_sh_size() == 0
6034 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6035 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6036 return false;
6037
6038 // Skip any discarded or ICF'ed sections.
6039 if (os == NULL || symtab->is_section_folded(this, shndx))
6040 return false;
6041
6042 // If this requires special offset handling, check to see if it is
6043 // a relaxed section. If this is not, then it is a merged section that
6044 // we cannot handle.
6045 if (this->is_output_section_offset_invalid(shndx))
6046 {
6047 const Output_relaxed_input_section* poris =
6048 os->find_relaxed_input_section(this, shndx);
6049 if (poris == NULL)
6050 return false;
6051 }
6052
6053 return true;
6054 }
6055
6056 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6057 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6058
6059 template<bool big_endian>
6060 bool
6061 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6062 const elfcpp::Shdr<32, big_endian>& shdr,
6063 const Relobj::Output_sections& out_sections,
6064 const Symbol_table* symtab,
6065 const unsigned char* pshdrs)
6066 {
6067 unsigned int sh_type = shdr.get_sh_type();
6068 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6069 return false;
6070
6071 // Ignore empty section.
6072 off_t sh_size = shdr.get_sh_size();
6073 if (sh_size == 0)
6074 return false;
6075
6076 // Ignore reloc section with unexpected symbol table. The
6077 // error will be reported in the final link.
6078 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6079 return false;
6080
6081 unsigned int reloc_size;
6082 if (sh_type == elfcpp::SHT_REL)
6083 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6084 else
6085 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6086
6087 // Ignore reloc section with unexpected entsize or uneven size.
6088 // The error will be reported in the final link.
6089 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6090 return false;
6091
6092 // Ignore reloc section with bad info. This error will be
6093 // reported in the final link.
6094 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6095 if (index >= this->shnum())
6096 return false;
6097
6098 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6099 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6100 return this->section_is_scannable(text_shdr, index,
6101 out_sections[index], symtab);
6102 }
6103
6104 // Return the output address of either a plain input section or a relaxed
6105 // input section. SHNDX is the section index. We define and use this
6106 // instead of calling Output_section::output_address because that is slow
6107 // for large output.
6108
6109 template<bool big_endian>
6110 Arm_address
6111 Arm_relobj<big_endian>::simple_input_section_output_address(
6112 unsigned int shndx,
6113 Output_section* os)
6114 {
6115 if (this->is_output_section_offset_invalid(shndx))
6116 {
6117 const Output_relaxed_input_section* poris =
6118 os->find_relaxed_input_section(this, shndx);
6119 // We do not handle merged sections here.
6120 gold_assert(poris != NULL);
6121 return poris->address();
6122 }
6123 else
6124 return os->address() + this->get_output_section_offset(shndx);
6125 }
6126
6127 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6128 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6129
6130 template<bool big_endian>
6131 bool
6132 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6133 const elfcpp::Shdr<32, big_endian>& shdr,
6134 unsigned int shndx,
6135 Output_section* os,
6136 const Symbol_table* symtab)
6137 {
6138 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6139 return false;
6140
6141 // If the section does not cross any 4K-boundaries, it does not need to
6142 // be scanned.
6143 Arm_address address = this->simple_input_section_output_address(shndx, os);
6144 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6145 return false;
6146
6147 return true;
6148 }
6149
6150 // Scan a section for Cortex-A8 workaround.
6151
6152 template<bool big_endian>
6153 void
6154 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6155 const elfcpp::Shdr<32, big_endian>& shdr,
6156 unsigned int shndx,
6157 Output_section* os,
6158 Target_arm<big_endian>* arm_target)
6159 {
6160 // Look for the first mapping symbol in this section. It should be
6161 // at (shndx, 0).
6162 Mapping_symbol_position section_start(shndx, 0);
6163 typename Mapping_symbols_info::const_iterator p =
6164 this->mapping_symbols_info_.lower_bound(section_start);
6165
6166 // There are no mapping symbols for this section. Treat it as a data-only
6167 // section. Issue a warning if section is marked as containing
6168 // instructions.
6169 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6170 {
6171 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6172 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6173 "erratum because it has no mapping symbols."),
6174 shndx, this->name().c_str());
6175 return;
6176 }
6177
6178 Arm_address output_address =
6179 this->simple_input_section_output_address(shndx, os);
6180
6181 // Get the section contents.
6182 section_size_type input_view_size = 0;
6183 const unsigned char* input_view =
6184 this->section_contents(shndx, &input_view_size, false);
6185
6186 // We need to go through the mapping symbols to determine what to
6187 // scan. There are two reasons. First, we should look at THUMB code and
6188 // THUMB code only. Second, we only want to look at the 4K-page boundary
6189 // to speed up the scanning.
6190
6191 while (p != this->mapping_symbols_info_.end()
6192 && p->first.first == shndx)
6193 {
6194 typename Mapping_symbols_info::const_iterator next =
6195 this->mapping_symbols_info_.upper_bound(p->first);
6196
6197 // Only scan part of a section with THUMB code.
6198 if (p->second == 't')
6199 {
6200 // Determine the end of this range.
6201 section_size_type span_start =
6202 convert_to_section_size_type(p->first.second);
6203 section_size_type span_end;
6204 if (next != this->mapping_symbols_info_.end()
6205 && next->first.first == shndx)
6206 span_end = convert_to_section_size_type(next->first.second);
6207 else
6208 span_end = convert_to_section_size_type(shdr.get_sh_size());
6209
6210 if (((span_start + output_address) & ~0xfffUL)
6211 != ((span_end + output_address - 1) & ~0xfffUL))
6212 {
6213 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6214 span_start, span_end,
6215 input_view,
6216 output_address);
6217 }
6218 }
6219
6220 p = next;
6221 }
6222 }
6223
6224 // Scan relocations for stub generation.
6225
6226 template<bool big_endian>
6227 void
6228 Arm_relobj<big_endian>::scan_sections_for_stubs(
6229 Target_arm<big_endian>* arm_target,
6230 const Symbol_table* symtab,
6231 const Layout* layout)
6232 {
6233 unsigned int shnum = this->shnum();
6234 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6235
6236 // Read the section headers.
6237 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6238 shnum * shdr_size,
6239 true, true);
6240
6241 // To speed up processing, we set up hash tables for fast lookup of
6242 // input offsets to output addresses.
6243 this->initialize_input_to_output_maps();
6244
6245 const Relobj::Output_sections& out_sections(this->output_sections());
6246
6247 Relocate_info<32, big_endian> relinfo;
6248 relinfo.symtab = symtab;
6249 relinfo.layout = layout;
6250 relinfo.object = this;
6251
6252 // Do relocation stubs scanning.
6253 const unsigned char* p = pshdrs + shdr_size;
6254 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6255 {
6256 const elfcpp::Shdr<32, big_endian> shdr(p);
6257 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6258 pshdrs))
6259 {
6260 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6261 Arm_address output_offset = this->get_output_section_offset(index);
6262 Arm_address output_address;
6263 if (output_offset != invalid_address)
6264 output_address = out_sections[index]->address() + output_offset;
6265 else
6266 {
6267 // Currently this only happens for a relaxed section.
6268 const Output_relaxed_input_section* poris =
6269 out_sections[index]->find_relaxed_input_section(this, index);
6270 gold_assert(poris != NULL);
6271 output_address = poris->address();
6272 }
6273
6274 // Get the relocations.
6275 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6276 shdr.get_sh_size(),
6277 true, false);
6278
6279 // Get the section contents. This does work for the case in which
6280 // we modify the contents of an input section. We need to pass the
6281 // output view under such circumstances.
6282 section_size_type input_view_size = 0;
6283 const unsigned char* input_view =
6284 this->section_contents(index, &input_view_size, false);
6285
6286 relinfo.reloc_shndx = i;
6287 relinfo.data_shndx = index;
6288 unsigned int sh_type = shdr.get_sh_type();
6289 unsigned int reloc_size;
6290 if (sh_type == elfcpp::SHT_REL)
6291 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6292 else
6293 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6294
6295 Output_section* os = out_sections[index];
6296 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6297 shdr.get_sh_size() / reloc_size,
6298 os,
6299 output_offset == invalid_address,
6300 input_view, output_address,
6301 input_view_size);
6302 }
6303 }
6304
6305 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6306 // after its relocation section, if there is one, is processed for
6307 // relocation stubs. Merging this loop with the one above would have been
6308 // complicated since we would have had to make sure that relocation stub
6309 // scanning is done first.
6310 if (arm_target->fix_cortex_a8())
6311 {
6312 const unsigned char* p = pshdrs + shdr_size;
6313 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6314 {
6315 const elfcpp::Shdr<32, big_endian> shdr(p);
6316 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6317 out_sections[i],
6318 symtab))
6319 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6320 arm_target);
6321 }
6322 }
6323
6324 // After we've done the relocations, we release the hash tables,
6325 // since we no longer need them.
6326 this->free_input_to_output_maps();
6327 }
6328
6329 // Count the local symbols. The ARM backend needs to know if a symbol
6330 // is a THUMB function or not. For global symbols, it is easy because
6331 // the Symbol object keeps the ELF symbol type. For local symbol it is
6332 // harder because we cannot access this information. So we override the
6333 // do_count_local_symbol in parent and scan local symbols to mark
6334 // THUMB functions. This is not the most efficient way but I do not want to
6335 // slow down other ports by calling a per symbol targer hook inside
6336 // Sized_relobj<size, big_endian>::do_count_local_symbols.
6337
6338 template<bool big_endian>
6339 void
6340 Arm_relobj<big_endian>::do_count_local_symbols(
6341 Stringpool_template<char>* pool,
6342 Stringpool_template<char>* dynpool)
6343 {
6344 // We need to fix-up the values of any local symbols whose type are
6345 // STT_ARM_TFUNC.
6346
6347 // Ask parent to count the local symbols.
6348 Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool);
6349 const unsigned int loccount = this->local_symbol_count();
6350 if (loccount == 0)
6351 return;
6352
6353 // Intialize the thumb function bit-vector.
6354 std::vector<bool> empty_vector(loccount, false);
6355 this->local_symbol_is_thumb_function_.swap(empty_vector);
6356
6357 // Read the symbol table section header.
6358 const unsigned int symtab_shndx = this->symtab_shndx();
6359 elfcpp::Shdr<32, big_endian>
6360 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6361 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6362
6363 // Read the local symbols.
6364 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6365 gold_assert(loccount == symtabshdr.get_sh_info());
6366 off_t locsize = loccount * sym_size;
6367 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6368 locsize, true, true);
6369
6370 // For mapping symbol processing, we need to read the symbol names.
6371 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6372 if (strtab_shndx >= this->shnum())
6373 {
6374 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6375 return;
6376 }
6377
6378 elfcpp::Shdr<32, big_endian>
6379 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6380 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6381 {
6382 this->error(_("symbol table name section has wrong type: %u"),
6383 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6384 return;
6385 }
6386 const char* pnames =
6387 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6388 strtabshdr.get_sh_size(),
6389 false, false));
6390
6391 // Loop over the local symbols and mark any local symbols pointing
6392 // to THUMB functions.
6393
6394 // Skip the first dummy symbol.
6395 psyms += sym_size;
6396 typename Sized_relobj<32, big_endian>::Local_values* plocal_values =
6397 this->local_values();
6398 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6399 {
6400 elfcpp::Sym<32, big_endian> sym(psyms);
6401 elfcpp::STT st_type = sym.get_st_type();
6402 Symbol_value<32>& lv((*plocal_values)[i]);
6403 Arm_address input_value = lv.input_value();
6404
6405 // Check to see if this is a mapping symbol.
6406 const char* sym_name = pnames + sym.get_st_name();
6407 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6408 {
6409 bool is_ordinary;
6410 unsigned int input_shndx =
6411 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6412 gold_assert(is_ordinary);
6413
6414 // Strip of LSB in case this is a THUMB symbol.
6415 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6416 this->mapping_symbols_info_[msp] = sym_name[1];
6417 }
6418
6419 if (st_type == elfcpp::STT_ARM_TFUNC
6420 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6421 {
6422 // This is a THUMB function. Mark this and canonicalize the
6423 // symbol value by setting LSB.
6424 this->local_symbol_is_thumb_function_[i] = true;
6425 if ((input_value & 1) == 0)
6426 lv.set_input_value(input_value | 1);
6427 }
6428 }
6429 }
6430
6431 // Relocate sections.
6432 template<bool big_endian>
6433 void
6434 Arm_relobj<big_endian>::do_relocate_sections(
6435 const Symbol_table* symtab,
6436 const Layout* layout,
6437 const unsigned char* pshdrs,
6438 Output_file* of,
6439 typename Sized_relobj<32, big_endian>::Views* pviews)
6440 {
6441 // Call parent to relocate sections.
6442 Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs,
6443 of, pviews);
6444
6445 // We do not generate stubs if doing a relocatable link.
6446 if (parameters->options().relocatable())
6447 return;
6448
6449 // Relocate stub tables.
6450 unsigned int shnum = this->shnum();
6451
6452 Target_arm<big_endian>* arm_target =
6453 Target_arm<big_endian>::default_target();
6454
6455 Relocate_info<32, big_endian> relinfo;
6456 relinfo.symtab = symtab;
6457 relinfo.layout = layout;
6458 relinfo.object = this;
6459
6460 for (unsigned int i = 1; i < shnum; ++i)
6461 {
6462 Arm_input_section<big_endian>* arm_input_section =
6463 arm_target->find_arm_input_section(this, i);
6464
6465 if (arm_input_section != NULL
6466 && arm_input_section->is_stub_table_owner()
6467 && !arm_input_section->stub_table()->empty())
6468 {
6469 // We cannot discard a section if it owns a stub table.
6470 Output_section* os = this->output_section(i);
6471 gold_assert(os != NULL);
6472
6473 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6474 relinfo.reloc_shdr = NULL;
6475 relinfo.data_shndx = i;
6476 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6477
6478 gold_assert((*pviews)[i].view != NULL);
6479
6480 // We are passed the output section view. Adjust it to cover the
6481 // stub table only.
6482 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6483 gold_assert((stub_table->address() >= (*pviews)[i].address)
6484 && ((stub_table->address() + stub_table->data_size())
6485 <= (*pviews)[i].address + (*pviews)[i].view_size));
6486
6487 off_t offset = stub_table->address() - (*pviews)[i].address;
6488 unsigned char* view = (*pviews)[i].view + offset;
6489 Arm_address address = stub_table->address();
6490 section_size_type view_size = stub_table->data_size();
6491
6492 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6493 view_size);
6494 }
6495
6496 // Apply Cortex A8 workaround if applicable.
6497 if (this->section_has_cortex_a8_workaround(i))
6498 {
6499 unsigned char* view = (*pviews)[i].view;
6500 Arm_address view_address = (*pviews)[i].address;
6501 section_size_type view_size = (*pviews)[i].view_size;
6502 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6503
6504 // Adjust view to cover section.
6505 Output_section* os = this->output_section(i);
6506 gold_assert(os != NULL);
6507 Arm_address section_address =
6508 this->simple_input_section_output_address(i, os);
6509 uint64_t section_size = this->section_size(i);
6510
6511 gold_assert(section_address >= view_address
6512 && ((section_address + section_size)
6513 <= (view_address + view_size)));
6514
6515 unsigned char* section_view = view + (section_address - view_address);
6516
6517 // Apply the Cortex-A8 workaround to the output address range
6518 // corresponding to this input section.
6519 stub_table->apply_cortex_a8_workaround_to_address_range(
6520 arm_target,
6521 section_view,
6522 section_address,
6523 section_size);
6524 }
6525 }
6526 }
6527
6528 // Find the linked text section of an EXIDX section by looking the the first
6529 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6530 // must be linked to to its associated code section via the sh_link field of
6531 // its section header. However, some tools are broken and the link is not
6532 // always set. LD just drops such an EXIDX section silently, causing the
6533 // associated code not unwindabled. Here we try a little bit harder to
6534 // discover the linked code section.
6535 //
6536 // PSHDR points to the section header of a relocation section of an EXIDX
6537 // section. If we can find a linked text section, return true and
6538 // store the text section index in the location PSHNDX. Otherwise
6539 // return false.
6540
6541 template<bool big_endian>
6542 bool
6543 Arm_relobj<big_endian>::find_linked_text_section(
6544 const unsigned char* pshdr,
6545 const unsigned char* psyms,
6546 unsigned int* pshndx)
6547 {
6548 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6549
6550 // If there is no relocation, we cannot find the linked text section.
6551 size_t reloc_size;
6552 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6553 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6554 else
6555 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6556 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6557
6558 // Get the relocations.
6559 const unsigned char* prelocs =
6560 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6561
6562 // Find the REL31 relocation for the first word of the first EXIDX entry.
6563 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6564 {
6565 Arm_address r_offset;
6566 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6567 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6568 {
6569 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6570 r_info = reloc.get_r_info();
6571 r_offset = reloc.get_r_offset();
6572 }
6573 else
6574 {
6575 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6576 r_info = reloc.get_r_info();
6577 r_offset = reloc.get_r_offset();
6578 }
6579
6580 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6581 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6582 continue;
6583
6584 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6585 if (r_sym == 0
6586 || r_sym >= this->local_symbol_count()
6587 || r_offset != 0)
6588 continue;
6589
6590 // This is the relocation for the first word of the first EXIDX entry.
6591 // We expect to see a local section symbol.
6592 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6593 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6594 if (sym.get_st_type() == elfcpp::STT_SECTION)
6595 {
6596 bool is_ordinary;
6597 *pshndx =
6598 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6599 gold_assert(is_ordinary);
6600 return true;
6601 }
6602 else
6603 return false;
6604 }
6605
6606 return false;
6607 }
6608
6609 // Make an EXIDX input section object for an EXIDX section whose index is
6610 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6611 // is the section index of the linked text section.
6612
6613 template<bool big_endian>
6614 void
6615 Arm_relobj<big_endian>::make_exidx_input_section(
6616 unsigned int shndx,
6617 const elfcpp::Shdr<32, big_endian>& shdr,
6618 unsigned int text_shndx,
6619 const elfcpp::Shdr<32, big_endian>& text_shdr)
6620 {
6621 // Create an Arm_exidx_input_section object for this EXIDX section.
6622 Arm_exidx_input_section* exidx_input_section =
6623 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6624 shdr.get_sh_addralign(),
6625 text_shdr.get_sh_size());
6626
6627 gold_assert(this->exidx_section_map_[shndx] == NULL);
6628 this->exidx_section_map_[shndx] = exidx_input_section;
6629
6630 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6631 {
6632 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6633 this->section_name(shndx).c_str(), shndx, text_shndx,
6634 this->name().c_str());
6635 exidx_input_section->set_has_errors();
6636 }
6637 else if (this->exidx_section_map_[text_shndx] != NULL)
6638 {
6639 unsigned other_exidx_shndx =
6640 this->exidx_section_map_[text_shndx]->shndx();
6641 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6642 "%s(%u) in %s"),
6643 this->section_name(shndx).c_str(), shndx,
6644 this->section_name(other_exidx_shndx).c_str(),
6645 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6646 text_shndx, this->name().c_str());
6647 exidx_input_section->set_has_errors();
6648 }
6649 else
6650 this->exidx_section_map_[text_shndx] = exidx_input_section;
6651
6652 // Check section flags of text section.
6653 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6654 {
6655 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6656 " in %s"),
6657 this->section_name(shndx).c_str(), shndx,
6658 this->section_name(text_shndx).c_str(), text_shndx,
6659 this->name().c_str());
6660 exidx_input_section->set_has_errors();
6661 }
6662 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6663 // I would like to make this an error but currenlty ld just ignores
6664 // this.
6665 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6666 "%s(%u) in %s"),
6667 this->section_name(shndx).c_str(), shndx,
6668 this->section_name(text_shndx).c_str(), text_shndx,
6669 this->name().c_str());
6670 }
6671
6672 // Read the symbol information.
6673
6674 template<bool big_endian>
6675 void
6676 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6677 {
6678 // Call parent class to read symbol information.
6679 Sized_relobj<32, big_endian>::do_read_symbols(sd);
6680
6681 // If this input file is a binary file, it has no processor
6682 // specific flags and attributes section.
6683 Input_file::Format format = this->input_file()->format();
6684 if (format != Input_file::FORMAT_ELF)
6685 {
6686 gold_assert(format == Input_file::FORMAT_BINARY);
6687 this->merge_flags_and_attributes_ = false;
6688 return;
6689 }
6690
6691 // Read processor-specific flags in ELF file header.
6692 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6693 elfcpp::Elf_sizes<32>::ehdr_size,
6694 true, false);
6695 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6696 this->processor_specific_flags_ = ehdr.get_e_flags();
6697
6698 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6699 // sections.
6700 std::vector<unsigned int> deferred_exidx_sections;
6701 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6702 const unsigned char* pshdrs = sd->section_headers->data();
6703 const unsigned char* ps = pshdrs + shdr_size;
6704 bool must_merge_flags_and_attributes = false;
6705 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6706 {
6707 elfcpp::Shdr<32, big_endian> shdr(ps);
6708
6709 // Sometimes an object has no contents except the section name string
6710 // table and an empty symbol table with the undefined symbol. We
6711 // don't want to merge processor-specific flags from such an object.
6712 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6713 {
6714 // Symbol table is not empty.
6715 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6716 elfcpp::Elf_sizes<32>::sym_size;
6717 if (shdr.get_sh_size() > sym_size)
6718 must_merge_flags_and_attributes = true;
6719 }
6720 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6721 // If this is neither an empty symbol table nor a string table,
6722 // be conservative.
6723 must_merge_flags_and_attributes = true;
6724
6725 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6726 {
6727 gold_assert(this->attributes_section_data_ == NULL);
6728 section_offset_type section_offset = shdr.get_sh_offset();
6729 section_size_type section_size =
6730 convert_to_section_size_type(shdr.get_sh_size());
6731 const unsigned char* view =
6732 this->get_view(section_offset, section_size, true, false);
6733 this->attributes_section_data_ =
6734 new Attributes_section_data(view, section_size);
6735 }
6736 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6737 {
6738 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6739 if (text_shndx == elfcpp::SHN_UNDEF)
6740 deferred_exidx_sections.push_back(i);
6741 else
6742 {
6743 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6744 + text_shndx * shdr_size);
6745 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6746 }
6747 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6748 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6749 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6750 this->section_name(i).c_str(), this->name().c_str());
6751 }
6752 }
6753
6754 // This is rare.
6755 if (!must_merge_flags_and_attributes)
6756 {
6757 gold_assert(deferred_exidx_sections.empty());
6758 this->merge_flags_and_attributes_ = false;
6759 return;
6760 }
6761
6762 // Some tools are broken and they do not set the link of EXIDX sections.
6763 // We look at the first relocation to figure out the linked sections.
6764 if (!deferred_exidx_sections.empty())
6765 {
6766 // We need to go over the section headers again to find the mapping
6767 // from sections being relocated to their relocation sections. This is
6768 // a bit inefficient as we could do that in the loop above. However,
6769 // we do not expect any deferred EXIDX sections normally. So we do not
6770 // want to slow down the most common path.
6771 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6772 Reloc_map reloc_map;
6773 ps = pshdrs + shdr_size;
6774 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6775 {
6776 elfcpp::Shdr<32, big_endian> shdr(ps);
6777 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6778 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6779 {
6780 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6781 if (info_shndx >= this->shnum())
6782 gold_error(_("relocation section %u has invalid info %u"),
6783 i, info_shndx);
6784 Reloc_map::value_type value(info_shndx, i);
6785 std::pair<Reloc_map::iterator, bool> result =
6786 reloc_map.insert(value);
6787 if (!result.second)
6788 gold_error(_("section %u has multiple relocation sections "
6789 "%u and %u"),
6790 info_shndx, i, reloc_map[info_shndx]);
6791 }
6792 }
6793
6794 // Read the symbol table section header.
6795 const unsigned int symtab_shndx = this->symtab_shndx();
6796 elfcpp::Shdr<32, big_endian>
6797 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6798 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6799
6800 // Read the local symbols.
6801 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6802 const unsigned int loccount = this->local_symbol_count();
6803 gold_assert(loccount == symtabshdr.get_sh_info());
6804 off_t locsize = loccount * sym_size;
6805 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6806 locsize, true, true);
6807
6808 // Process the deferred EXIDX sections.
6809 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6810 {
6811 unsigned int shndx = deferred_exidx_sections[i];
6812 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6813 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6814 Reloc_map::const_iterator it = reloc_map.find(shndx);
6815 if (it != reloc_map.end())
6816 find_linked_text_section(pshdrs + it->second * shdr_size,
6817 psyms, &text_shndx);
6818 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6819 + text_shndx * shdr_size);
6820 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6821 }
6822 }
6823 }
6824
6825 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6826 // sections for unwinding. These sections are referenced implicitly by
6827 // text sections linked in the section headers. If we ignore these implict
6828 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6829 // will be garbage-collected incorrectly. Hence we override the same function
6830 // in the base class to handle these implicit references.
6831
6832 template<bool big_endian>
6833 void
6834 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6835 Layout* layout,
6836 Read_relocs_data* rd)
6837 {
6838 // First, call base class method to process relocations in this object.
6839 Sized_relobj<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6840
6841 // If --gc-sections is not specified, there is nothing more to do.
6842 // This happens when --icf is used but --gc-sections is not.
6843 if (!parameters->options().gc_sections())
6844 return;
6845
6846 unsigned int shnum = this->shnum();
6847 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6848 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6849 shnum * shdr_size,
6850 true, true);
6851
6852 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6853 // to these from the linked text sections.
6854 const unsigned char* ps = pshdrs + shdr_size;
6855 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6856 {
6857 elfcpp::Shdr<32, big_endian> shdr(ps);
6858 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6859 {
6860 // Found an .ARM.exidx section, add it to the set of reachable
6861 // sections from its linked text section.
6862 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6863 symtab->gc()->add_reference(this, text_shndx, this, i);
6864 }
6865 }
6866 }
6867
6868 // Update output local symbol count. Owing to EXIDX entry merging, some local
6869 // symbols will be removed in output. Adjust output local symbol count
6870 // accordingly. We can only changed the static output local symbol count. It
6871 // is too late to change the dynamic symbols.
6872
6873 template<bool big_endian>
6874 void
6875 Arm_relobj<big_endian>::update_output_local_symbol_count()
6876 {
6877 // Caller should check that this needs updating. We want caller checking
6878 // because output_local_symbol_count_needs_update() is most likely inlined.
6879 gold_assert(this->output_local_symbol_count_needs_update_);
6880
6881 gold_assert(this->symtab_shndx() != -1U);
6882 if (this->symtab_shndx() == 0)
6883 {
6884 // This object has no symbols. Weird but legal.
6885 return;
6886 }
6887
6888 // Read the symbol table section header.
6889 const unsigned int symtab_shndx = this->symtab_shndx();
6890 elfcpp::Shdr<32, big_endian>
6891 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6892 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6893
6894 // Read the local symbols.
6895 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6896 const unsigned int loccount = this->local_symbol_count();
6897 gold_assert(loccount == symtabshdr.get_sh_info());
6898 off_t locsize = loccount * sym_size;
6899 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6900 locsize, true, true);
6901
6902 // Loop over the local symbols.
6903
6904 typedef typename Sized_relobj<32, big_endian>::Output_sections
6905 Output_sections;
6906 const Output_sections& out_sections(this->output_sections());
6907 unsigned int shnum = this->shnum();
6908 unsigned int count = 0;
6909 // Skip the first, dummy, symbol.
6910 psyms += sym_size;
6911 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6912 {
6913 elfcpp::Sym<32, big_endian> sym(psyms);
6914
6915 Symbol_value<32>& lv((*this->local_values())[i]);
6916
6917 // This local symbol was already discarded by do_count_local_symbols.
6918 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6919 continue;
6920
6921 bool is_ordinary;
6922 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6923 &is_ordinary);
6924
6925 if (shndx < shnum)
6926 {
6927 Output_section* os = out_sections[shndx];
6928
6929 // This local symbol no longer has an output section. Discard it.
6930 if (os == NULL)
6931 {
6932 lv.set_no_output_symtab_entry();
6933 continue;
6934 }
6935
6936 // Currently we only discard parts of EXIDX input sections.
6937 // We explicitly check for a merged EXIDX input section to avoid
6938 // calling Output_section_data::output_offset unless necessary.
6939 if ((this->get_output_section_offset(shndx) == invalid_address)
6940 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6941 {
6942 section_offset_type output_offset =
6943 os->output_offset(this, shndx, lv.input_value());
6944 if (output_offset == -1)
6945 {
6946 // This symbol is defined in a part of an EXIDX input section
6947 // that is discarded due to entry merging.
6948 lv.set_no_output_symtab_entry();
6949 continue;
6950 }
6951 }
6952 }
6953
6954 ++count;
6955 }
6956
6957 this->set_output_local_symbol_count(count);
6958 this->output_local_symbol_count_needs_update_ = false;
6959 }
6960
6961 // Arm_dynobj methods.
6962
6963 // Read the symbol information.
6964
6965 template<bool big_endian>
6966 void
6967 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6968 {
6969 // Call parent class to read symbol information.
6970 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6971
6972 // Read processor-specific flags in ELF file header.
6973 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6974 elfcpp::Elf_sizes<32>::ehdr_size,
6975 true, false);
6976 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6977 this->processor_specific_flags_ = ehdr.get_e_flags();
6978
6979 // Read the attributes section if there is one.
6980 // We read from the end because gas seems to put it near the end of
6981 // the section headers.
6982 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6983 const unsigned char* ps =
6984 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6985 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6986 {
6987 elfcpp::Shdr<32, big_endian> shdr(ps);
6988 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6989 {
6990 section_offset_type section_offset = shdr.get_sh_offset();
6991 section_size_type section_size =
6992 convert_to_section_size_type(shdr.get_sh_size());
6993 const unsigned char* view =
6994 this->get_view(section_offset, section_size, true, false);
6995 this->attributes_section_data_ =
6996 new Attributes_section_data(view, section_size);
6997 break;
6998 }
6999 }
7000 }
7001
7002 // Stub_addend_reader methods.
7003
7004 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7005
7006 template<bool big_endian>
7007 elfcpp::Elf_types<32>::Elf_Swxword
7008 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7009 unsigned int r_type,
7010 const unsigned char* view,
7011 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7012 {
7013 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
7014
7015 switch (r_type)
7016 {
7017 case elfcpp::R_ARM_CALL:
7018 case elfcpp::R_ARM_JUMP24:
7019 case elfcpp::R_ARM_PLT32:
7020 {
7021 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7022 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7023 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7024 return utils::sign_extend<26>(val << 2);
7025 }
7026
7027 case elfcpp::R_ARM_THM_CALL:
7028 case elfcpp::R_ARM_THM_JUMP24:
7029 case elfcpp::R_ARM_THM_XPC22:
7030 {
7031 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7032 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7033 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7034 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7035 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7036 }
7037
7038 case elfcpp::R_ARM_THM_JUMP19:
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_cond_branch_offset(upper_insn, lower_insn);
7045 }
7046
7047 default:
7048 gold_unreachable();
7049 }
7050 }
7051
7052 // Arm_output_data_got methods.
7053
7054 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7055 // The first one is initialized to be 1, which is the module index for
7056 // the main executable and the second one 0. A reloc of the type
7057 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7058 // be applied by gold. GSYM is a global symbol.
7059 //
7060 template<bool big_endian>
7061 void
7062 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7063 unsigned int got_type,
7064 Symbol* gsym)
7065 {
7066 if (gsym->has_got_offset(got_type))
7067 return;
7068
7069 // We are doing a static link. Just mark it as belong to module 1,
7070 // the executable.
7071 unsigned int got_offset = this->add_constant(1);
7072 gsym->set_got_offset(got_type, got_offset);
7073 got_offset = this->add_constant(0);
7074 this->static_relocs_.push_back(Static_reloc(got_offset,
7075 elfcpp::R_ARM_TLS_DTPOFF32,
7076 gsym));
7077 }
7078
7079 // Same as the above but for a local symbol.
7080
7081 template<bool big_endian>
7082 void
7083 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7084 unsigned int got_type,
7085 Sized_relobj<32, big_endian>* object,
7086 unsigned int index)
7087 {
7088 if (object->local_has_got_offset(index, got_type))
7089 return;
7090
7091 // We are doing a static link. Just mark it as belong to module 1,
7092 // the executable.
7093 unsigned int got_offset = this->add_constant(1);
7094 object->set_local_got_offset(index, got_type, got_offset);
7095 got_offset = this->add_constant(0);
7096 this->static_relocs_.push_back(Static_reloc(got_offset,
7097 elfcpp::R_ARM_TLS_DTPOFF32,
7098 object, index));
7099 }
7100
7101 template<bool big_endian>
7102 void
7103 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7104 {
7105 // Call parent to write out GOT.
7106 Output_data_got<32, big_endian>::do_write(of);
7107
7108 // We are done if there is no fix up.
7109 if (this->static_relocs_.empty())
7110 return;
7111
7112 gold_assert(parameters->doing_static_link());
7113
7114 const off_t offset = this->offset();
7115 const section_size_type oview_size =
7116 convert_to_section_size_type(this->data_size());
7117 unsigned char* const oview = of->get_output_view(offset, oview_size);
7118
7119 Output_segment* tls_segment = this->layout_->tls_segment();
7120 gold_assert(tls_segment != NULL);
7121
7122 // The thread pointer $tp points to the TCB, which is followed by the
7123 // TLS. So we need to adjust $tp relative addressing by this amount.
7124 Arm_address aligned_tcb_size =
7125 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7126
7127 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7128 {
7129 Static_reloc& reloc(this->static_relocs_[i]);
7130
7131 Arm_address value;
7132 if (!reloc.symbol_is_global())
7133 {
7134 Sized_relobj<32, big_endian>* object = reloc.relobj();
7135 const Symbol_value<32>* psymval =
7136 reloc.relobj()->local_symbol(reloc.index());
7137
7138 // We are doing static linking. Issue an error and skip this
7139 // relocation if the symbol is undefined or in a discarded_section.
7140 bool is_ordinary;
7141 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7142 if ((shndx == elfcpp::SHN_UNDEF)
7143 || (is_ordinary
7144 && shndx != elfcpp::SHN_UNDEF
7145 && !object->is_section_included(shndx)
7146 && !this->symbol_table_->is_section_folded(object, shndx)))
7147 {
7148 gold_error(_("undefined or discarded local symbol %u from "
7149 " object %s in GOT"),
7150 reloc.index(), reloc.relobj()->name().c_str());
7151 continue;
7152 }
7153
7154 value = psymval->value(object, 0);
7155 }
7156 else
7157 {
7158 const Symbol* gsym = reloc.symbol();
7159 gold_assert(gsym != NULL);
7160 if (gsym->is_forwarder())
7161 gsym = this->symbol_table_->resolve_forwards(gsym);
7162
7163 // We are doing static linking. Issue an error and skip this
7164 // relocation if the symbol is undefined or in a discarded_section
7165 // unless it is a weakly_undefined symbol.
7166 if ((gsym->is_defined_in_discarded_section()
7167 || gsym->is_undefined())
7168 && !gsym->is_weak_undefined())
7169 {
7170 gold_error(_("undefined or discarded symbol %s in GOT"),
7171 gsym->name());
7172 continue;
7173 }
7174
7175 if (!gsym->is_weak_undefined())
7176 {
7177 const Sized_symbol<32>* sym =
7178 static_cast<const Sized_symbol<32>*>(gsym);
7179 value = sym->value();
7180 }
7181 else
7182 value = 0;
7183 }
7184
7185 unsigned got_offset = reloc.got_offset();
7186 gold_assert(got_offset < oview_size);
7187
7188 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7189 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7190 Valtype x;
7191 switch (reloc.r_type())
7192 {
7193 case elfcpp::R_ARM_TLS_DTPOFF32:
7194 x = value;
7195 break;
7196 case elfcpp::R_ARM_TLS_TPOFF32:
7197 x = value + aligned_tcb_size;
7198 break;
7199 default:
7200 gold_unreachable();
7201 }
7202 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7203 }
7204
7205 of->write_output_view(offset, oview_size, oview);
7206 }
7207
7208 // A class to handle the PLT data.
7209
7210 template<bool big_endian>
7211 class Output_data_plt_arm : public Output_section_data
7212 {
7213 public:
7214 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7215 Reloc_section;
7216
7217 Output_data_plt_arm(Layout*, Output_data_space*);
7218
7219 // Add an entry to the PLT.
7220 void
7221 add_entry(Symbol* gsym);
7222
7223 // Return the .rel.plt section data.
7224 const Reloc_section*
7225 rel_plt() const
7226 { return this->rel_; }
7227
7228 // Return the number of PLT entries.
7229 unsigned int
7230 entry_count() const
7231 { return this->count_; }
7232
7233 // Return the offset of the first non-reserved PLT entry.
7234 static unsigned int
7235 first_plt_entry_offset()
7236 { return sizeof(first_plt_entry); }
7237
7238 // Return the size of a PLT entry.
7239 static unsigned int
7240 get_plt_entry_size()
7241 { return sizeof(plt_entry); }
7242
7243 protected:
7244 void
7245 do_adjust_output_section(Output_section* os);
7246
7247 // Write to a map file.
7248 void
7249 do_print_to_mapfile(Mapfile* mapfile) const
7250 { mapfile->print_output_data(this, _("** PLT")); }
7251
7252 private:
7253 // Template for the first PLT entry.
7254 static const uint32_t first_plt_entry[5];
7255
7256 // Template for subsequent PLT entries.
7257 static const uint32_t plt_entry[3];
7258
7259 // Set the final size.
7260 void
7261 set_final_data_size()
7262 {
7263 this->set_data_size(sizeof(first_plt_entry)
7264 + this->count_ * sizeof(plt_entry));
7265 }
7266
7267 // Write out the PLT data.
7268 void
7269 do_write(Output_file*);
7270
7271 // The reloc section.
7272 Reloc_section* rel_;
7273 // The .got.plt section.
7274 Output_data_space* got_plt_;
7275 // The number of PLT entries.
7276 unsigned int count_;
7277 };
7278
7279 // Create the PLT section. The ordinary .got section is an argument,
7280 // since we need to refer to the start. We also create our own .got
7281 // section just for PLT entries.
7282
7283 template<bool big_endian>
7284 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7285 Output_data_space* got_plt)
7286 : Output_section_data(4), got_plt_(got_plt), count_(0)
7287 {
7288 this->rel_ = new Reloc_section(false);
7289 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7290 elfcpp::SHF_ALLOC, this->rel_,
7291 ORDER_DYNAMIC_PLT_RELOCS, false);
7292 }
7293
7294 template<bool big_endian>
7295 void
7296 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7297 {
7298 os->set_entsize(0);
7299 }
7300
7301 // Add an entry to the PLT.
7302
7303 template<bool big_endian>
7304 void
7305 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7306 {
7307 gold_assert(!gsym->has_plt_offset());
7308
7309 // Note that when setting the PLT offset we skip the initial
7310 // reserved PLT entry.
7311 gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
7312 + sizeof(first_plt_entry));
7313
7314 ++this->count_;
7315
7316 section_offset_type got_offset = this->got_plt_->current_data_size();
7317
7318 // Every PLT entry needs a GOT entry which points back to the PLT
7319 // entry (this will be changed by the dynamic linker, normally
7320 // lazily when the function is called).
7321 this->got_plt_->set_current_data_size(got_offset + 4);
7322
7323 // Every PLT entry needs a reloc.
7324 gsym->set_needs_dynsym_entry();
7325 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7326 got_offset);
7327
7328 // Note that we don't need to save the symbol. The contents of the
7329 // PLT are independent of which symbols are used. The symbols only
7330 // appear in the relocations.
7331 }
7332
7333 // ARM PLTs.
7334 // FIXME: This is not very flexible. Right now this has only been tested
7335 // on armv5te. If we are to support additional architecture features like
7336 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7337
7338 // The first entry in the PLT.
7339 template<bool big_endian>
7340 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
7341 {
7342 0xe52de004, // str lr, [sp, #-4]!
7343 0xe59fe004, // ldr lr, [pc, #4]
7344 0xe08fe00e, // add lr, pc, lr
7345 0xe5bef008, // ldr pc, [lr, #8]!
7346 0x00000000, // &GOT[0] - .
7347 };
7348
7349 // Subsequent entries in the PLT.
7350
7351 template<bool big_endian>
7352 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
7353 {
7354 0xe28fc600, // add ip, pc, #0xNN00000
7355 0xe28cca00, // add ip, ip, #0xNN000
7356 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7357 };
7358
7359 // Write out the PLT. This uses the hand-coded instructions above,
7360 // and adjusts them as needed. This is all specified by the arm ELF
7361 // Processor Supplement.
7362
7363 template<bool big_endian>
7364 void
7365 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7366 {
7367 const off_t offset = this->offset();
7368 const section_size_type oview_size =
7369 convert_to_section_size_type(this->data_size());
7370 unsigned char* const oview = of->get_output_view(offset, oview_size);
7371
7372 const off_t got_file_offset = this->got_plt_->offset();
7373 const section_size_type got_size =
7374 convert_to_section_size_type(this->got_plt_->data_size());
7375 unsigned char* const got_view = of->get_output_view(got_file_offset,
7376 got_size);
7377 unsigned char* pov = oview;
7378
7379 Arm_address plt_address = this->address();
7380 Arm_address got_address = this->got_plt_->address();
7381
7382 // Write first PLT entry. All but the last word are constants.
7383 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7384 / sizeof(plt_entry[0]));
7385 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7386 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7387 // Last word in first PLT entry is &GOT[0] - .
7388 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7389 got_address - (plt_address + 16));
7390 pov += sizeof(first_plt_entry);
7391
7392 unsigned char* got_pov = got_view;
7393
7394 memset(got_pov, 0, 12);
7395 got_pov += 12;
7396
7397 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
7398 unsigned int plt_offset = sizeof(first_plt_entry);
7399 unsigned int plt_rel_offset = 0;
7400 unsigned int got_offset = 12;
7401 const unsigned int count = this->count_;
7402 for (unsigned int i = 0;
7403 i < count;
7404 ++i,
7405 pov += sizeof(plt_entry),
7406 got_pov += 4,
7407 plt_offset += sizeof(plt_entry),
7408 plt_rel_offset += rel_size,
7409 got_offset += 4)
7410 {
7411 // Set and adjust the PLT entry itself.
7412 int32_t offset = ((got_address + got_offset)
7413 - (plt_address + plt_offset + 8));
7414
7415 gold_assert(offset >= 0 && offset < 0x0fffffff);
7416 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7417 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7418 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7419 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7420 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7421 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7422
7423 // Set the entry in the GOT.
7424 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7425 }
7426
7427 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7428 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7429
7430 of->write_output_view(offset, oview_size, oview);
7431 of->write_output_view(got_file_offset, got_size, got_view);
7432 }
7433
7434 // Create a PLT entry for a global symbol.
7435
7436 template<bool big_endian>
7437 void
7438 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7439 Symbol* gsym)
7440 {
7441 if (gsym->has_plt_offset())
7442 return;
7443
7444 if (this->plt_ == NULL)
7445 {
7446 // Create the GOT sections first.
7447 this->got_section(symtab, layout);
7448
7449 this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7450 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7451 (elfcpp::SHF_ALLOC
7452 | elfcpp::SHF_EXECINSTR),
7453 this->plt_, ORDER_PLT, false);
7454 }
7455 this->plt_->add_entry(gsym);
7456 }
7457
7458 // Return the number of entries in the PLT.
7459
7460 template<bool big_endian>
7461 unsigned int
7462 Target_arm<big_endian>::plt_entry_count() const
7463 {
7464 if (this->plt_ == NULL)
7465 return 0;
7466 return this->plt_->entry_count();
7467 }
7468
7469 // Return the offset of the first non-reserved PLT entry.
7470
7471 template<bool big_endian>
7472 unsigned int
7473 Target_arm<big_endian>::first_plt_entry_offset() const
7474 {
7475 return Output_data_plt_arm<big_endian>::first_plt_entry_offset();
7476 }
7477
7478 // Return the size of each PLT entry.
7479
7480 template<bool big_endian>
7481 unsigned int
7482 Target_arm<big_endian>::plt_entry_size() const
7483 {
7484 return Output_data_plt_arm<big_endian>::get_plt_entry_size();
7485 }
7486
7487 // Get the section to use for TLS_DESC relocations.
7488
7489 template<bool big_endian>
7490 typename Target_arm<big_endian>::Reloc_section*
7491 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7492 {
7493 return this->plt_section()->rel_tls_desc(layout);
7494 }
7495
7496 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7497
7498 template<bool big_endian>
7499 void
7500 Target_arm<big_endian>::define_tls_base_symbol(
7501 Symbol_table* symtab,
7502 Layout* layout)
7503 {
7504 if (this->tls_base_symbol_defined_)
7505 return;
7506
7507 Output_segment* tls_segment = layout->tls_segment();
7508 if (tls_segment != NULL)
7509 {
7510 bool is_exec = parameters->options().output_is_executable();
7511 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7512 Symbol_table::PREDEFINED,
7513 tls_segment, 0, 0,
7514 elfcpp::STT_TLS,
7515 elfcpp::STB_LOCAL,
7516 elfcpp::STV_HIDDEN, 0,
7517 (is_exec
7518 ? Symbol::SEGMENT_END
7519 : Symbol::SEGMENT_START),
7520 true);
7521 }
7522 this->tls_base_symbol_defined_ = true;
7523 }
7524
7525 // Create a GOT entry for the TLS module index.
7526
7527 template<bool big_endian>
7528 unsigned int
7529 Target_arm<big_endian>::got_mod_index_entry(
7530 Symbol_table* symtab,
7531 Layout* layout,
7532 Sized_relobj<32, big_endian>* object)
7533 {
7534 if (this->got_mod_index_offset_ == -1U)
7535 {
7536 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7537 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7538 unsigned int got_offset;
7539 if (!parameters->doing_static_link())
7540 {
7541 got_offset = got->add_constant(0);
7542 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7543 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7544 got_offset);
7545 }
7546 else
7547 {
7548 // We are doing a static link. Just mark it as belong to module 1,
7549 // the executable.
7550 got_offset = got->add_constant(1);
7551 }
7552
7553 got->add_constant(0);
7554 this->got_mod_index_offset_ = got_offset;
7555 }
7556 return this->got_mod_index_offset_;
7557 }
7558
7559 // Optimize the TLS relocation type based on what we know about the
7560 // symbol. IS_FINAL is true if the final address of this symbol is
7561 // known at link time.
7562
7563 template<bool big_endian>
7564 tls::Tls_optimization
7565 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7566 {
7567 // FIXME: Currently we do not do any TLS optimization.
7568 return tls::TLSOPT_NONE;
7569 }
7570
7571 // Report an unsupported relocation against a local symbol.
7572
7573 template<bool big_endian>
7574 void
7575 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7576 Sized_relobj<32, big_endian>* object,
7577 unsigned int r_type)
7578 {
7579 gold_error(_("%s: unsupported reloc %u against local symbol"),
7580 object->name().c_str(), r_type);
7581 }
7582
7583 // We are about to emit a dynamic relocation of type R_TYPE. If the
7584 // dynamic linker does not support it, issue an error. The GNU linker
7585 // only issues a non-PIC error for an allocated read-only section.
7586 // Here we know the section is allocated, but we don't know that it is
7587 // read-only. But we check for all the relocation types which the
7588 // glibc dynamic linker supports, so it seems appropriate to issue an
7589 // error even if the section is not read-only.
7590
7591 template<bool big_endian>
7592 void
7593 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7594 unsigned int r_type)
7595 {
7596 switch (r_type)
7597 {
7598 // These are the relocation types supported by glibc for ARM.
7599 case elfcpp::R_ARM_RELATIVE:
7600 case elfcpp::R_ARM_COPY:
7601 case elfcpp::R_ARM_GLOB_DAT:
7602 case elfcpp::R_ARM_JUMP_SLOT:
7603 case elfcpp::R_ARM_ABS32:
7604 case elfcpp::R_ARM_ABS32_NOI:
7605 case elfcpp::R_ARM_PC24:
7606 // FIXME: The following 3 types are not supported by Android's dynamic
7607 // linker.
7608 case elfcpp::R_ARM_TLS_DTPMOD32:
7609 case elfcpp::R_ARM_TLS_DTPOFF32:
7610 case elfcpp::R_ARM_TLS_TPOFF32:
7611 return;
7612
7613 default:
7614 {
7615 // This prevents us from issuing more than one error per reloc
7616 // section. But we can still wind up issuing more than one
7617 // error per object file.
7618 if (this->issued_non_pic_error_)
7619 return;
7620 const Arm_reloc_property* reloc_property =
7621 arm_reloc_property_table->get_reloc_property(r_type);
7622 gold_assert(reloc_property != NULL);
7623 object->error(_("requires unsupported dynamic reloc %s; "
7624 "recompile with -fPIC"),
7625 reloc_property->name().c_str());
7626 this->issued_non_pic_error_ = true;
7627 return;
7628 }
7629
7630 case elfcpp::R_ARM_NONE:
7631 gold_unreachable();
7632 }
7633 }
7634
7635 // Scan a relocation for a local symbol.
7636 // FIXME: This only handles a subset of relocation types used by Android
7637 // on ARM v5te devices.
7638
7639 template<bool big_endian>
7640 inline void
7641 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7642 Layout* layout,
7643 Target_arm* target,
7644 Sized_relobj<32, big_endian>* object,
7645 unsigned int data_shndx,
7646 Output_section* output_section,
7647 const elfcpp::Rel<32, big_endian>& reloc,
7648 unsigned int r_type,
7649 const elfcpp::Sym<32, big_endian>& lsym)
7650 {
7651 r_type = get_real_reloc_type(r_type);
7652 switch (r_type)
7653 {
7654 case elfcpp::R_ARM_NONE:
7655 case elfcpp::R_ARM_V4BX:
7656 case elfcpp::R_ARM_GNU_VTENTRY:
7657 case elfcpp::R_ARM_GNU_VTINHERIT:
7658 break;
7659
7660 case elfcpp::R_ARM_ABS32:
7661 case elfcpp::R_ARM_ABS32_NOI:
7662 // If building a shared library (or a position-independent
7663 // executable), we need to create a dynamic relocation for
7664 // this location. The relocation applied at link time will
7665 // apply the link-time value, so we flag the location with
7666 // an R_ARM_RELATIVE relocation so the dynamic loader can
7667 // relocate it easily.
7668 if (parameters->options().output_is_position_independent())
7669 {
7670 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7671 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7672 // If we are to add more other reloc types than R_ARM_ABS32,
7673 // we need to add check_non_pic(object, r_type) here.
7674 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7675 output_section, data_shndx,
7676 reloc.get_r_offset());
7677 }
7678 break;
7679
7680 case elfcpp::R_ARM_ABS16:
7681 case elfcpp::R_ARM_ABS12:
7682 case elfcpp::R_ARM_THM_ABS5:
7683 case elfcpp::R_ARM_ABS8:
7684 case elfcpp::R_ARM_BASE_ABS:
7685 case elfcpp::R_ARM_MOVW_ABS_NC:
7686 case elfcpp::R_ARM_MOVT_ABS:
7687 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7688 case elfcpp::R_ARM_THM_MOVT_ABS:
7689 // If building a shared library (or a position-independent
7690 // executable), we need to create a dynamic relocation for
7691 // this location. Because the addend needs to remain in the
7692 // data section, we need to be careful not to apply this
7693 // relocation statically.
7694 if (parameters->options().output_is_position_independent())
7695 {
7696 check_non_pic(object, r_type);
7697 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7698 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7699 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7700 rel_dyn->add_local(object, r_sym, r_type, output_section,
7701 data_shndx, reloc.get_r_offset());
7702 else
7703 {
7704 gold_assert(lsym.get_st_value() == 0);
7705 unsigned int shndx = lsym.get_st_shndx();
7706 bool is_ordinary;
7707 shndx = object->adjust_sym_shndx(r_sym, shndx,
7708 &is_ordinary);
7709 if (!is_ordinary)
7710 object->error(_("section symbol %u has bad shndx %u"),
7711 r_sym, shndx);
7712 else
7713 rel_dyn->add_local_section(object, shndx,
7714 r_type, output_section,
7715 data_shndx, reloc.get_r_offset());
7716 }
7717 }
7718 break;
7719
7720 case elfcpp::R_ARM_REL32:
7721 case elfcpp::R_ARM_LDR_PC_G0:
7722 case elfcpp::R_ARM_SBREL32:
7723 case elfcpp::R_ARM_THM_CALL:
7724 case elfcpp::R_ARM_THM_PC8:
7725 case elfcpp::R_ARM_BASE_PREL:
7726 case elfcpp::R_ARM_PLT32:
7727 case elfcpp::R_ARM_CALL:
7728 case elfcpp::R_ARM_JUMP24:
7729 case elfcpp::R_ARM_THM_JUMP24:
7730 case elfcpp::R_ARM_SBREL31:
7731 case elfcpp::R_ARM_PREL31:
7732 case elfcpp::R_ARM_MOVW_PREL_NC:
7733 case elfcpp::R_ARM_MOVT_PREL:
7734 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7735 case elfcpp::R_ARM_THM_MOVT_PREL:
7736 case elfcpp::R_ARM_THM_JUMP19:
7737 case elfcpp::R_ARM_THM_JUMP6:
7738 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7739 case elfcpp::R_ARM_THM_PC12:
7740 case elfcpp::R_ARM_REL32_NOI:
7741 case elfcpp::R_ARM_ALU_PC_G0_NC:
7742 case elfcpp::R_ARM_ALU_PC_G0:
7743 case elfcpp::R_ARM_ALU_PC_G1_NC:
7744 case elfcpp::R_ARM_ALU_PC_G1:
7745 case elfcpp::R_ARM_ALU_PC_G2:
7746 case elfcpp::R_ARM_LDR_PC_G1:
7747 case elfcpp::R_ARM_LDR_PC_G2:
7748 case elfcpp::R_ARM_LDRS_PC_G0:
7749 case elfcpp::R_ARM_LDRS_PC_G1:
7750 case elfcpp::R_ARM_LDRS_PC_G2:
7751 case elfcpp::R_ARM_LDC_PC_G0:
7752 case elfcpp::R_ARM_LDC_PC_G1:
7753 case elfcpp::R_ARM_LDC_PC_G2:
7754 case elfcpp::R_ARM_ALU_SB_G0_NC:
7755 case elfcpp::R_ARM_ALU_SB_G0:
7756 case elfcpp::R_ARM_ALU_SB_G1_NC:
7757 case elfcpp::R_ARM_ALU_SB_G1:
7758 case elfcpp::R_ARM_ALU_SB_G2:
7759 case elfcpp::R_ARM_LDR_SB_G0:
7760 case elfcpp::R_ARM_LDR_SB_G1:
7761 case elfcpp::R_ARM_LDR_SB_G2:
7762 case elfcpp::R_ARM_LDRS_SB_G0:
7763 case elfcpp::R_ARM_LDRS_SB_G1:
7764 case elfcpp::R_ARM_LDRS_SB_G2:
7765 case elfcpp::R_ARM_LDC_SB_G0:
7766 case elfcpp::R_ARM_LDC_SB_G1:
7767 case elfcpp::R_ARM_LDC_SB_G2:
7768 case elfcpp::R_ARM_MOVW_BREL_NC:
7769 case elfcpp::R_ARM_MOVT_BREL:
7770 case elfcpp::R_ARM_MOVW_BREL:
7771 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7772 case elfcpp::R_ARM_THM_MOVT_BREL:
7773 case elfcpp::R_ARM_THM_MOVW_BREL:
7774 case elfcpp::R_ARM_THM_JUMP11:
7775 case elfcpp::R_ARM_THM_JUMP8:
7776 // We don't need to do anything for a relative addressing relocation
7777 // against a local symbol if it does not reference the GOT.
7778 break;
7779
7780 case elfcpp::R_ARM_GOTOFF32:
7781 case elfcpp::R_ARM_GOTOFF12:
7782 // We need a GOT section:
7783 target->got_section(symtab, layout);
7784 break;
7785
7786 case elfcpp::R_ARM_GOT_BREL:
7787 case elfcpp::R_ARM_GOT_PREL:
7788 {
7789 // The symbol requires a GOT entry.
7790 Arm_output_data_got<big_endian>* got =
7791 target->got_section(symtab, layout);
7792 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7793 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7794 {
7795 // If we are generating a shared object, we need to add a
7796 // dynamic RELATIVE relocation for this symbol's GOT entry.
7797 if (parameters->options().output_is_position_independent())
7798 {
7799 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7800 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7801 rel_dyn->add_local_relative(
7802 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7803 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7804 }
7805 }
7806 }
7807 break;
7808
7809 case elfcpp::R_ARM_TARGET1:
7810 case elfcpp::R_ARM_TARGET2:
7811 // This should have been mapped to another type already.
7812 // Fall through.
7813 case elfcpp::R_ARM_COPY:
7814 case elfcpp::R_ARM_GLOB_DAT:
7815 case elfcpp::R_ARM_JUMP_SLOT:
7816 case elfcpp::R_ARM_RELATIVE:
7817 // These are relocations which should only be seen by the
7818 // dynamic linker, and should never be seen here.
7819 gold_error(_("%s: unexpected reloc %u in object file"),
7820 object->name().c_str(), r_type);
7821 break;
7822
7823
7824 // These are initial TLS relocs, which are expected when
7825 // linking.
7826 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7827 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7828 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7829 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7830 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7831 {
7832 bool output_is_shared = parameters->options().shared();
7833 const tls::Tls_optimization optimized_type
7834 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7835 r_type);
7836 switch (r_type)
7837 {
7838 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7839 if (optimized_type == tls::TLSOPT_NONE)
7840 {
7841 // Create a pair of GOT entries for the module index and
7842 // dtv-relative offset.
7843 Arm_output_data_got<big_endian>* got
7844 = target->got_section(symtab, layout);
7845 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7846 unsigned int shndx = lsym.get_st_shndx();
7847 bool is_ordinary;
7848 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7849 if (!is_ordinary)
7850 {
7851 object->error(_("local symbol %u has bad shndx %u"),
7852 r_sym, shndx);
7853 break;
7854 }
7855
7856 if (!parameters->doing_static_link())
7857 got->add_local_pair_with_rel(object, r_sym, shndx,
7858 GOT_TYPE_TLS_PAIR,
7859 target->rel_dyn_section(layout),
7860 elfcpp::R_ARM_TLS_DTPMOD32, 0);
7861 else
7862 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7863 object, r_sym);
7864 }
7865 else
7866 // FIXME: TLS optimization not supported yet.
7867 gold_unreachable();
7868 break;
7869
7870 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7871 if (optimized_type == tls::TLSOPT_NONE)
7872 {
7873 // Create a GOT entry for the module index.
7874 target->got_mod_index_entry(symtab, layout, object);
7875 }
7876 else
7877 // FIXME: TLS optimization not supported yet.
7878 gold_unreachable();
7879 break;
7880
7881 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7882 break;
7883
7884 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7885 layout->set_has_static_tls();
7886 if (optimized_type == tls::TLSOPT_NONE)
7887 {
7888 // Create a GOT entry for the tp-relative offset.
7889 Arm_output_data_got<big_endian>* got
7890 = target->got_section(symtab, layout);
7891 unsigned int r_sym =
7892 elfcpp::elf_r_sym<32>(reloc.get_r_info());
7893 if (!parameters->doing_static_link())
7894 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7895 target->rel_dyn_section(layout),
7896 elfcpp::R_ARM_TLS_TPOFF32);
7897 else if (!object->local_has_got_offset(r_sym,
7898 GOT_TYPE_TLS_OFFSET))
7899 {
7900 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7901 unsigned int got_offset =
7902 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7903 got->add_static_reloc(got_offset,
7904 elfcpp::R_ARM_TLS_TPOFF32, object,
7905 r_sym);
7906 }
7907 }
7908 else
7909 // FIXME: TLS optimization not supported yet.
7910 gold_unreachable();
7911 break;
7912
7913 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7914 layout->set_has_static_tls();
7915 if (output_is_shared)
7916 {
7917 // We need to create a dynamic relocation.
7918 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
7919 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7920 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7921 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
7922 output_section, data_shndx,
7923 reloc.get_r_offset());
7924 }
7925 break;
7926
7927 default:
7928 gold_unreachable();
7929 }
7930 }
7931 break;
7932
7933 case elfcpp::R_ARM_PC24:
7934 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7935 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7936 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7937 default:
7938 unsupported_reloc_local(object, r_type);
7939 break;
7940 }
7941 }
7942
7943 // Report an unsupported relocation against a global symbol.
7944
7945 template<bool big_endian>
7946 void
7947 Target_arm<big_endian>::Scan::unsupported_reloc_global(
7948 Sized_relobj<32, big_endian>* object,
7949 unsigned int r_type,
7950 Symbol* gsym)
7951 {
7952 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
7953 object->name().c_str(), r_type, gsym->demangled_name().c_str());
7954 }
7955
7956 template<bool big_endian>
7957 inline bool
7958 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
7959 unsigned int r_type)
7960 {
7961 switch (r_type)
7962 {
7963 case elfcpp::R_ARM_PC24:
7964 case elfcpp::R_ARM_THM_CALL:
7965 case elfcpp::R_ARM_PLT32:
7966 case elfcpp::R_ARM_CALL:
7967 case elfcpp::R_ARM_JUMP24:
7968 case elfcpp::R_ARM_THM_JUMP24:
7969 case elfcpp::R_ARM_SBREL31:
7970 case elfcpp::R_ARM_PREL31:
7971 case elfcpp::R_ARM_THM_JUMP19:
7972 case elfcpp::R_ARM_THM_JUMP6:
7973 case elfcpp::R_ARM_THM_JUMP11:
7974 case elfcpp::R_ARM_THM_JUMP8:
7975 // All the relocations above are branches except SBREL31 and PREL31.
7976 return false;
7977
7978 default:
7979 // Be conservative and assume this is a function pointer.
7980 return true;
7981 }
7982 }
7983
7984 template<bool big_endian>
7985 inline bool
7986 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
7987 Symbol_table*,
7988 Layout*,
7989 Target_arm<big_endian>* target,
7990 Sized_relobj<32, big_endian>*,
7991 unsigned int,
7992 Output_section*,
7993 const elfcpp::Rel<32, big_endian>&,
7994 unsigned int r_type,
7995 const elfcpp::Sym<32, big_endian>&)
7996 {
7997 r_type = target->get_real_reloc_type(r_type);
7998 return possible_function_pointer_reloc(r_type);
7999 }
8000
8001 template<bool big_endian>
8002 inline bool
8003 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8004 Symbol_table*,
8005 Layout*,
8006 Target_arm<big_endian>* target,
8007 Sized_relobj<32, big_endian>*,
8008 unsigned int,
8009 Output_section*,
8010 const elfcpp::Rel<32, big_endian>&,
8011 unsigned int r_type,
8012 Symbol* gsym)
8013 {
8014 // GOT is not a function.
8015 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8016 return false;
8017
8018 r_type = target->get_real_reloc_type(r_type);
8019 return possible_function_pointer_reloc(r_type);
8020 }
8021
8022 // Scan a relocation for a global symbol.
8023
8024 template<bool big_endian>
8025 inline void
8026 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8027 Layout* layout,
8028 Target_arm* target,
8029 Sized_relobj<32, big_endian>* object,
8030 unsigned int data_shndx,
8031 Output_section* output_section,
8032 const elfcpp::Rel<32, big_endian>& reloc,
8033 unsigned int r_type,
8034 Symbol* gsym)
8035 {
8036 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8037 // section. We check here to avoid creating a dynamic reloc against
8038 // _GLOBAL_OFFSET_TABLE_.
8039 if (!target->has_got_section()
8040 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8041 target->got_section(symtab, layout);
8042
8043 r_type = get_real_reloc_type(r_type);
8044 switch (r_type)
8045 {
8046 case elfcpp::R_ARM_NONE:
8047 case elfcpp::R_ARM_V4BX:
8048 case elfcpp::R_ARM_GNU_VTENTRY:
8049 case elfcpp::R_ARM_GNU_VTINHERIT:
8050 break;
8051
8052 case elfcpp::R_ARM_ABS32:
8053 case elfcpp::R_ARM_ABS16:
8054 case elfcpp::R_ARM_ABS12:
8055 case elfcpp::R_ARM_THM_ABS5:
8056 case elfcpp::R_ARM_ABS8:
8057 case elfcpp::R_ARM_BASE_ABS:
8058 case elfcpp::R_ARM_MOVW_ABS_NC:
8059 case elfcpp::R_ARM_MOVT_ABS:
8060 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8061 case elfcpp::R_ARM_THM_MOVT_ABS:
8062 case elfcpp::R_ARM_ABS32_NOI:
8063 // Absolute addressing relocations.
8064 {
8065 // Make a PLT entry if necessary.
8066 if (this->symbol_needs_plt_entry(gsym))
8067 {
8068 target->make_plt_entry(symtab, layout, gsym);
8069 // Since this is not a PC-relative relocation, we may be
8070 // taking the address of a function. In that case we need to
8071 // set the entry in the dynamic symbol table to the address of
8072 // the PLT entry.
8073 if (gsym->is_from_dynobj() && !parameters->options().shared())
8074 gsym->set_needs_dynsym_value();
8075 }
8076 // Make a dynamic relocation if necessary.
8077 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
8078 {
8079 if (gsym->may_need_copy_reloc())
8080 {
8081 target->copy_reloc(symtab, layout, object,
8082 data_shndx, output_section, gsym, reloc);
8083 }
8084 else if ((r_type == elfcpp::R_ARM_ABS32
8085 || r_type == elfcpp::R_ARM_ABS32_NOI)
8086 && gsym->can_use_relative_reloc(false))
8087 {
8088 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8089 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8090 output_section, object,
8091 data_shndx, reloc.get_r_offset());
8092 }
8093 else
8094 {
8095 check_non_pic(object, r_type);
8096 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8097 rel_dyn->add_global(gsym, r_type, output_section, object,
8098 data_shndx, reloc.get_r_offset());
8099 }
8100 }
8101 }
8102 break;
8103
8104 case elfcpp::R_ARM_GOTOFF32:
8105 case elfcpp::R_ARM_GOTOFF12:
8106 // We need a GOT section.
8107 target->got_section(symtab, layout);
8108 break;
8109
8110 case elfcpp::R_ARM_REL32:
8111 case elfcpp::R_ARM_LDR_PC_G0:
8112 case elfcpp::R_ARM_SBREL32:
8113 case elfcpp::R_ARM_THM_PC8:
8114 case elfcpp::R_ARM_BASE_PREL:
8115 case elfcpp::R_ARM_MOVW_PREL_NC:
8116 case elfcpp::R_ARM_MOVT_PREL:
8117 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8118 case elfcpp::R_ARM_THM_MOVT_PREL:
8119 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8120 case elfcpp::R_ARM_THM_PC12:
8121 case elfcpp::R_ARM_REL32_NOI:
8122 case elfcpp::R_ARM_ALU_PC_G0_NC:
8123 case elfcpp::R_ARM_ALU_PC_G0:
8124 case elfcpp::R_ARM_ALU_PC_G1_NC:
8125 case elfcpp::R_ARM_ALU_PC_G1:
8126 case elfcpp::R_ARM_ALU_PC_G2:
8127 case elfcpp::R_ARM_LDR_PC_G1:
8128 case elfcpp::R_ARM_LDR_PC_G2:
8129 case elfcpp::R_ARM_LDRS_PC_G0:
8130 case elfcpp::R_ARM_LDRS_PC_G1:
8131 case elfcpp::R_ARM_LDRS_PC_G2:
8132 case elfcpp::R_ARM_LDC_PC_G0:
8133 case elfcpp::R_ARM_LDC_PC_G1:
8134 case elfcpp::R_ARM_LDC_PC_G2:
8135 case elfcpp::R_ARM_ALU_SB_G0_NC:
8136 case elfcpp::R_ARM_ALU_SB_G0:
8137 case elfcpp::R_ARM_ALU_SB_G1_NC:
8138 case elfcpp::R_ARM_ALU_SB_G1:
8139 case elfcpp::R_ARM_ALU_SB_G2:
8140 case elfcpp::R_ARM_LDR_SB_G0:
8141 case elfcpp::R_ARM_LDR_SB_G1:
8142 case elfcpp::R_ARM_LDR_SB_G2:
8143 case elfcpp::R_ARM_LDRS_SB_G0:
8144 case elfcpp::R_ARM_LDRS_SB_G1:
8145 case elfcpp::R_ARM_LDRS_SB_G2:
8146 case elfcpp::R_ARM_LDC_SB_G0:
8147 case elfcpp::R_ARM_LDC_SB_G1:
8148 case elfcpp::R_ARM_LDC_SB_G2:
8149 case elfcpp::R_ARM_MOVW_BREL_NC:
8150 case elfcpp::R_ARM_MOVT_BREL:
8151 case elfcpp::R_ARM_MOVW_BREL:
8152 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8153 case elfcpp::R_ARM_THM_MOVT_BREL:
8154 case elfcpp::R_ARM_THM_MOVW_BREL:
8155 // Relative addressing relocations.
8156 {
8157 // Make a dynamic relocation if necessary.
8158 int flags = Symbol::NON_PIC_REF;
8159 if (gsym->needs_dynamic_reloc(flags))
8160 {
8161 if (target->may_need_copy_reloc(gsym))
8162 {
8163 target->copy_reloc(symtab, layout, object,
8164 data_shndx, output_section, gsym, reloc);
8165 }
8166 else
8167 {
8168 check_non_pic(object, r_type);
8169 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8170 rel_dyn->add_global(gsym, r_type, output_section, object,
8171 data_shndx, reloc.get_r_offset());
8172 }
8173 }
8174 }
8175 break;
8176
8177 case elfcpp::R_ARM_THM_CALL:
8178 case elfcpp::R_ARM_PLT32:
8179 case elfcpp::R_ARM_CALL:
8180 case elfcpp::R_ARM_JUMP24:
8181 case elfcpp::R_ARM_THM_JUMP24:
8182 case elfcpp::R_ARM_SBREL31:
8183 case elfcpp::R_ARM_PREL31:
8184 case elfcpp::R_ARM_THM_JUMP19:
8185 case elfcpp::R_ARM_THM_JUMP6:
8186 case elfcpp::R_ARM_THM_JUMP11:
8187 case elfcpp::R_ARM_THM_JUMP8:
8188 // All the relocation above are branches except for the PREL31 ones.
8189 // A PREL31 relocation can point to a personality function in a shared
8190 // library. In that case we want to use a PLT because we want to
8191 // call the personality routine and the dyanmic linkers we care about
8192 // do not support dynamic PREL31 relocations. An REL31 relocation may
8193 // point to a function whose unwinding behaviour is being described but
8194 // we will not mistakenly generate a PLT for that because we should use
8195 // a local section symbol.
8196
8197 // If the symbol is fully resolved, this is just a relative
8198 // local reloc. Otherwise we need a PLT entry.
8199 if (gsym->final_value_is_known())
8200 break;
8201 // If building a shared library, we can also skip the PLT entry
8202 // if the symbol is defined in the output file and is protected
8203 // or hidden.
8204 if (gsym->is_defined()
8205 && !gsym->is_from_dynobj()
8206 && !gsym->is_preemptible())
8207 break;
8208 target->make_plt_entry(symtab, layout, gsym);
8209 break;
8210
8211 case elfcpp::R_ARM_GOT_BREL:
8212 case elfcpp::R_ARM_GOT_ABS:
8213 case elfcpp::R_ARM_GOT_PREL:
8214 {
8215 // The symbol requires a GOT entry.
8216 Arm_output_data_got<big_endian>* got =
8217 target->got_section(symtab, layout);
8218 if (gsym->final_value_is_known())
8219 got->add_global(gsym, GOT_TYPE_STANDARD);
8220 else
8221 {
8222 // If this symbol is not fully resolved, we need to add a
8223 // GOT entry with a dynamic relocation.
8224 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8225 if (gsym->is_from_dynobj()
8226 || gsym->is_undefined()
8227 || gsym->is_preemptible())
8228 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8229 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8230 else
8231 {
8232 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8233 rel_dyn->add_global_relative(
8234 gsym, elfcpp::R_ARM_RELATIVE, got,
8235 gsym->got_offset(GOT_TYPE_STANDARD));
8236 }
8237 }
8238 }
8239 break;
8240
8241 case elfcpp::R_ARM_TARGET1:
8242 case elfcpp::R_ARM_TARGET2:
8243 // These should have been mapped to other types already.
8244 // Fall through.
8245 case elfcpp::R_ARM_COPY:
8246 case elfcpp::R_ARM_GLOB_DAT:
8247 case elfcpp::R_ARM_JUMP_SLOT:
8248 case elfcpp::R_ARM_RELATIVE:
8249 // These are relocations which should only be seen by the
8250 // dynamic linker, and should never be seen here.
8251 gold_error(_("%s: unexpected reloc %u in object file"),
8252 object->name().c_str(), r_type);
8253 break;
8254
8255 // These are initial tls relocs, which are expected when
8256 // linking.
8257 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8258 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8259 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8260 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8261 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8262 {
8263 const bool is_final = gsym->final_value_is_known();
8264 const tls::Tls_optimization optimized_type
8265 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8266 switch (r_type)
8267 {
8268 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8269 if (optimized_type == tls::TLSOPT_NONE)
8270 {
8271 // Create a pair of GOT entries for the module index and
8272 // dtv-relative offset.
8273 Arm_output_data_got<big_endian>* got
8274 = target->got_section(symtab, layout);
8275 if (!parameters->doing_static_link())
8276 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8277 target->rel_dyn_section(layout),
8278 elfcpp::R_ARM_TLS_DTPMOD32,
8279 elfcpp::R_ARM_TLS_DTPOFF32);
8280 else
8281 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8282 }
8283 else
8284 // FIXME: TLS optimization not supported yet.
8285 gold_unreachable();
8286 break;
8287
8288 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8289 if (optimized_type == tls::TLSOPT_NONE)
8290 {
8291 // Create a GOT entry for the module index.
8292 target->got_mod_index_entry(symtab, layout, object);
8293 }
8294 else
8295 // FIXME: TLS optimization not supported yet.
8296 gold_unreachable();
8297 break;
8298
8299 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8300 break;
8301
8302 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8303 layout->set_has_static_tls();
8304 if (optimized_type == tls::TLSOPT_NONE)
8305 {
8306 // Create a GOT entry for the tp-relative offset.
8307 Arm_output_data_got<big_endian>* got
8308 = target->got_section(symtab, layout);
8309 if (!parameters->doing_static_link())
8310 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8311 target->rel_dyn_section(layout),
8312 elfcpp::R_ARM_TLS_TPOFF32);
8313 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8314 {
8315 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8316 unsigned int got_offset =
8317 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8318 got->add_static_reloc(got_offset,
8319 elfcpp::R_ARM_TLS_TPOFF32, gsym);
8320 }
8321 }
8322 else
8323 // FIXME: TLS optimization not supported yet.
8324 gold_unreachable();
8325 break;
8326
8327 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8328 layout->set_has_static_tls();
8329 if (parameters->options().shared())
8330 {
8331 // We need to create a dynamic relocation.
8332 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8333 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8334 output_section, object,
8335 data_shndx, reloc.get_r_offset());
8336 }
8337 break;
8338
8339 default:
8340 gold_unreachable();
8341 }
8342 }
8343 break;
8344
8345 case elfcpp::R_ARM_PC24:
8346 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8347 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8348 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8349 default:
8350 unsupported_reloc_global(object, r_type, gsym);
8351 break;
8352 }
8353 }
8354
8355 // Process relocations for gc.
8356
8357 template<bool big_endian>
8358 void
8359 Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab,
8360 Layout* layout,
8361 Sized_relobj<32, big_endian>* object,
8362 unsigned int data_shndx,
8363 unsigned int,
8364 const unsigned char* prelocs,
8365 size_t reloc_count,
8366 Output_section* output_section,
8367 bool needs_special_offset_handling,
8368 size_t local_symbol_count,
8369 const unsigned char* plocal_symbols)
8370 {
8371 typedef Target_arm<big_endian> Arm;
8372 typedef typename Target_arm<big_endian>::Scan Scan;
8373
8374 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8375 typename Target_arm::Relocatable_size_for_reloc>(
8376 symtab,
8377 layout,
8378 this,
8379 object,
8380 data_shndx,
8381 prelocs,
8382 reloc_count,
8383 output_section,
8384 needs_special_offset_handling,
8385 local_symbol_count,
8386 plocal_symbols);
8387 }
8388
8389 // Scan relocations for a section.
8390
8391 template<bool big_endian>
8392 void
8393 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8394 Layout* layout,
8395 Sized_relobj<32, big_endian>* object,
8396 unsigned int data_shndx,
8397 unsigned int sh_type,
8398 const unsigned char* prelocs,
8399 size_t reloc_count,
8400 Output_section* output_section,
8401 bool needs_special_offset_handling,
8402 size_t local_symbol_count,
8403 const unsigned char* plocal_symbols)
8404 {
8405 typedef typename Target_arm<big_endian>::Scan Scan;
8406 if (sh_type == elfcpp::SHT_RELA)
8407 {
8408 gold_error(_("%s: unsupported RELA reloc section"),
8409 object->name().c_str());
8410 return;
8411 }
8412
8413 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8414 symtab,
8415 layout,
8416 this,
8417 object,
8418 data_shndx,
8419 prelocs,
8420 reloc_count,
8421 output_section,
8422 needs_special_offset_handling,
8423 local_symbol_count,
8424 plocal_symbols);
8425 }
8426
8427 // Finalize the sections.
8428
8429 template<bool big_endian>
8430 void
8431 Target_arm<big_endian>::do_finalize_sections(
8432 Layout* layout,
8433 const Input_objects* input_objects,
8434 Symbol_table* symtab)
8435 {
8436 bool merged_any_attributes = false;
8437 // Merge processor-specific flags.
8438 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8439 p != input_objects->relobj_end();
8440 ++p)
8441 {
8442 Arm_relobj<big_endian>* arm_relobj =
8443 Arm_relobj<big_endian>::as_arm_relobj(*p);
8444 if (arm_relobj->merge_flags_and_attributes())
8445 {
8446 this->merge_processor_specific_flags(
8447 arm_relobj->name(),
8448 arm_relobj->processor_specific_flags());
8449 this->merge_object_attributes(arm_relobj->name().c_str(),
8450 arm_relobj->attributes_section_data());
8451 merged_any_attributes = true;
8452 }
8453 }
8454
8455 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8456 p != input_objects->dynobj_end();
8457 ++p)
8458 {
8459 Arm_dynobj<big_endian>* arm_dynobj =
8460 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8461 this->merge_processor_specific_flags(
8462 arm_dynobj->name(),
8463 arm_dynobj->processor_specific_flags());
8464 this->merge_object_attributes(arm_dynobj->name().c_str(),
8465 arm_dynobj->attributes_section_data());
8466 merged_any_attributes = true;
8467 }
8468
8469 // Create an empty uninitialized attribute section if we still don't have it
8470 // at this moment. This happens if there is no attributes sections in all
8471 // inputs.
8472 if (this->attributes_section_data_ == NULL)
8473 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8474
8475 // Check BLX use.
8476 const Object_attribute* cpu_arch_attr =
8477 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8478 if (cpu_arch_attr->int_value() > elfcpp::TAG_CPU_ARCH_V4)
8479 this->set_may_use_blx(true);
8480
8481 // Check if we need to use Cortex-A8 workaround.
8482 if (parameters->options().user_set_fix_cortex_a8())
8483 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8484 else
8485 {
8486 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8487 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8488 // profile.
8489 const Object_attribute* cpu_arch_profile_attr =
8490 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8491 this->fix_cortex_a8_ =
8492 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8493 && (cpu_arch_profile_attr->int_value() == 'A'
8494 || cpu_arch_profile_attr->int_value() == 0));
8495 }
8496
8497 // Check if we can use V4BX interworking.
8498 // The V4BX interworking stub contains BX instruction,
8499 // which is not specified for some profiles.
8500 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8501 && !this->may_use_blx())
8502 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8503 "the target profile does not support BX instruction"));
8504
8505 // Fill in some more dynamic tags.
8506 const Reloc_section* rel_plt = (this->plt_ == NULL
8507 ? NULL
8508 : this->plt_->rel_plt());
8509 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8510 this->rel_dyn_, true, false);
8511
8512 // Emit any relocs we saved in an attempt to avoid generating COPY
8513 // relocs.
8514 if (this->copy_relocs_.any_saved_relocs())
8515 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8516
8517 // Handle the .ARM.exidx section.
8518 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8519
8520 if (!parameters->options().relocatable())
8521 {
8522 if (exidx_section != NULL
8523 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8524 {
8525 // Create __exidx_start and __exdix_end symbols.
8526 symtab->define_in_output_data("__exidx_start", NULL,
8527 Symbol_table::PREDEFINED,
8528 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8529 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8530 0, false, true);
8531 symtab->define_in_output_data("__exidx_end", NULL,
8532 Symbol_table::PREDEFINED,
8533 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8534 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8535 0, true, true);
8536
8537 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8538 // the .ARM.exidx section.
8539 if (!layout->script_options()->saw_phdrs_clause())
8540 {
8541 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8542 0)
8543 == NULL);
8544 Output_segment* exidx_segment =
8545 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8546 exidx_segment->add_output_section_to_nonload(exidx_section,
8547 elfcpp::PF_R);
8548 }
8549 }
8550 else
8551 {
8552 symtab->define_as_constant("__exidx_start", NULL,
8553 Symbol_table::PREDEFINED,
8554 0, 0, elfcpp::STT_OBJECT,
8555 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8556 true, false);
8557 symtab->define_as_constant("__exidx_end", NULL,
8558 Symbol_table::PREDEFINED,
8559 0, 0, elfcpp::STT_OBJECT,
8560 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8561 true, false);
8562 }
8563 }
8564
8565 // Create an .ARM.attributes section if we have merged any attributes
8566 // from inputs.
8567 if (merged_any_attributes)
8568 {
8569 Output_attributes_section_data* attributes_section =
8570 new Output_attributes_section_data(*this->attributes_section_data_);
8571 layout->add_output_section_data(".ARM.attributes",
8572 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8573 attributes_section, ORDER_INVALID,
8574 false);
8575 }
8576
8577 // Fix up links in section EXIDX headers.
8578 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8579 p != layout->section_list().end();
8580 ++p)
8581 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8582 {
8583 Arm_output_section<big_endian>* os =
8584 Arm_output_section<big_endian>::as_arm_output_section(*p);
8585 os->set_exidx_section_link();
8586 }
8587 }
8588
8589 // Return whether a direct absolute static relocation needs to be applied.
8590 // In cases where Scan::local() or Scan::global() has created
8591 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8592 // of the relocation is carried in the data, and we must not
8593 // apply the static relocation.
8594
8595 template<bool big_endian>
8596 inline bool
8597 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8598 const Sized_symbol<32>* gsym,
8599 int ref_flags,
8600 bool is_32bit,
8601 Output_section* output_section)
8602 {
8603 // If the output section is not allocated, then we didn't call
8604 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8605 // the reloc here.
8606 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8607 return true;
8608
8609 // For local symbols, we will have created a non-RELATIVE dynamic
8610 // relocation only if (a) the output is position independent,
8611 // (b) the relocation is absolute (not pc- or segment-relative), and
8612 // (c) the relocation is not 32 bits wide.
8613 if (gsym == NULL)
8614 return !(parameters->options().output_is_position_independent()
8615 && (ref_flags & Symbol::ABSOLUTE_REF)
8616 && !is_32bit);
8617
8618 // For global symbols, we use the same helper routines used in the
8619 // scan pass. If we did not create a dynamic relocation, or if we
8620 // created a RELATIVE dynamic relocation, we should apply the static
8621 // relocation.
8622 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8623 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8624 && gsym->can_use_relative_reloc(ref_flags
8625 & Symbol::FUNCTION_CALL);
8626 return !has_dyn || is_rel;
8627 }
8628
8629 // Perform a relocation.
8630
8631 template<bool big_endian>
8632 inline bool
8633 Target_arm<big_endian>::Relocate::relocate(
8634 const Relocate_info<32, big_endian>* relinfo,
8635 Target_arm* target,
8636 Output_section* output_section,
8637 size_t relnum,
8638 const elfcpp::Rel<32, big_endian>& rel,
8639 unsigned int r_type,
8640 const Sized_symbol<32>* gsym,
8641 const Symbol_value<32>* psymval,
8642 unsigned char* view,
8643 Arm_address address,
8644 section_size_type view_size)
8645 {
8646 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8647
8648 r_type = get_real_reloc_type(r_type);
8649 const Arm_reloc_property* reloc_property =
8650 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8651 if (reloc_property == NULL)
8652 {
8653 std::string reloc_name =
8654 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8655 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8656 _("cannot relocate %s in object file"),
8657 reloc_name.c_str());
8658 return true;
8659 }
8660
8661 const Arm_relobj<big_endian>* object =
8662 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8663
8664 // If the final branch target of a relocation is THUMB instruction, this
8665 // is 1. Otherwise it is 0.
8666 Arm_address thumb_bit = 0;
8667 Symbol_value<32> symval;
8668 bool is_weakly_undefined_without_plt = false;
8669 bool have_got_offset = false;
8670 unsigned int got_offset = 0;
8671
8672 // If the relocation uses the GOT entry of a symbol instead of the symbol
8673 // itself, we don't care about whether the symbol is defined or what kind
8674 // of symbol it is.
8675 if (reloc_property->uses_got_entry())
8676 {
8677 // Get the GOT offset.
8678 // The GOT pointer points to the end of the GOT section.
8679 // We need to subtract the size of the GOT section to get
8680 // the actual offset to use in the relocation.
8681 // TODO: We should move GOT offset computing code in TLS relocations
8682 // to here.
8683 switch (r_type)
8684 {
8685 case elfcpp::R_ARM_GOT_BREL:
8686 case elfcpp::R_ARM_GOT_PREL:
8687 if (gsym != NULL)
8688 {
8689 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8690 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8691 - target->got_size());
8692 }
8693 else
8694 {
8695 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8696 gold_assert(object->local_has_got_offset(r_sym,
8697 GOT_TYPE_STANDARD));
8698 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8699 - target->got_size());
8700 }
8701 have_got_offset = true;
8702 break;
8703
8704 default:
8705 break;
8706 }
8707 }
8708 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8709 {
8710 if (gsym != NULL)
8711 {
8712 // This is a global symbol. Determine if we use PLT and if the
8713 // final target is THUMB.
8714 if (gsym->use_plt_offset(reloc_is_non_pic(r_type)))
8715 {
8716 // This uses a PLT, change the symbol value.
8717 symval.set_output_value(target->plt_section()->address()
8718 + gsym->plt_offset());
8719 psymval = &symval;
8720 }
8721 else if (gsym->is_weak_undefined())
8722 {
8723 // This is a weakly undefined symbol and we do not use PLT
8724 // for this relocation. A branch targeting this symbol will
8725 // be converted into an NOP.
8726 is_weakly_undefined_without_plt = true;
8727 }
8728 else if (gsym->is_undefined() && reloc_property->uses_symbol())
8729 {
8730 // This relocation uses the symbol value but the symbol is
8731 // undefined. Exit early and have the caller reporting an
8732 // error.
8733 return true;
8734 }
8735 else
8736 {
8737 // Set thumb bit if symbol:
8738 // -Has type STT_ARM_TFUNC or
8739 // -Has type STT_FUNC, is defined and with LSB in value set.
8740 thumb_bit =
8741 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8742 || (gsym->type() == elfcpp::STT_FUNC
8743 && !gsym->is_undefined()
8744 && ((psymval->value(object, 0) & 1) != 0)))
8745 ? 1
8746 : 0);
8747 }
8748 }
8749 else
8750 {
8751 // This is a local symbol. Determine if the final target is THUMB.
8752 // We saved this information when all the local symbols were read.
8753 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8754 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8755 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8756 }
8757 }
8758 else
8759 {
8760 // This is a fake relocation synthesized for a stub. It does not have
8761 // a real symbol. We just look at the LSB of the symbol value to
8762 // determine if the target is THUMB or not.
8763 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8764 }
8765
8766 // Strip LSB if this points to a THUMB target.
8767 if (thumb_bit != 0
8768 && reloc_property->uses_thumb_bit()
8769 && ((psymval->value(object, 0) & 1) != 0))
8770 {
8771 Arm_address stripped_value =
8772 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8773 symval.set_output_value(stripped_value);
8774 psymval = &symval;
8775 }
8776
8777 // To look up relocation stubs, we need to pass the symbol table index of
8778 // a local symbol.
8779 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8780
8781 // Get the addressing origin of the output segment defining the
8782 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8783 Arm_address sym_origin = 0;
8784 if (reloc_property->uses_symbol_base())
8785 {
8786 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8787 // R_ARM_BASE_ABS with the NULL symbol will give the
8788 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8789 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8790 sym_origin = target->got_plt_section()->address();
8791 else if (gsym == NULL)
8792 sym_origin = 0;
8793 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8794 sym_origin = gsym->output_segment()->vaddr();
8795 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8796 sym_origin = gsym->output_data()->address();
8797
8798 // TODO: Assumes the segment base to be zero for the global symbols
8799 // till the proper support for the segment-base-relative addressing
8800 // will be implemented. This is consistent with GNU ld.
8801 }
8802
8803 // For relative addressing relocation, find out the relative address base.
8804 Arm_address relative_address_base = 0;
8805 switch(reloc_property->relative_address_base())
8806 {
8807 case Arm_reloc_property::RAB_NONE:
8808 // Relocations with relative address bases RAB_TLS and RAB_tp are
8809 // handled by relocate_tls. So we do not need to do anything here.
8810 case Arm_reloc_property::RAB_TLS:
8811 case Arm_reloc_property::RAB_tp:
8812 break;
8813 case Arm_reloc_property::RAB_B_S:
8814 relative_address_base = sym_origin;
8815 break;
8816 case Arm_reloc_property::RAB_GOT_ORG:
8817 relative_address_base = target->got_plt_section()->address();
8818 break;
8819 case Arm_reloc_property::RAB_P:
8820 relative_address_base = address;
8821 break;
8822 case Arm_reloc_property::RAB_Pa:
8823 relative_address_base = address & 0xfffffffcU;
8824 break;
8825 default:
8826 gold_unreachable();
8827 }
8828
8829 typename Arm_relocate_functions::Status reloc_status =
8830 Arm_relocate_functions::STATUS_OKAY;
8831 bool check_overflow = reloc_property->checks_overflow();
8832 switch (r_type)
8833 {
8834 case elfcpp::R_ARM_NONE:
8835 break;
8836
8837 case elfcpp::R_ARM_ABS8:
8838 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8839 output_section))
8840 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8841 break;
8842
8843 case elfcpp::R_ARM_ABS12:
8844 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8845 output_section))
8846 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8847 break;
8848
8849 case elfcpp::R_ARM_ABS16:
8850 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8851 output_section))
8852 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8853 break;
8854
8855 case elfcpp::R_ARM_ABS32:
8856 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8857 output_section))
8858 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8859 thumb_bit);
8860 break;
8861
8862 case elfcpp::R_ARM_ABS32_NOI:
8863 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8864 output_section))
8865 // No thumb bit for this relocation: (S + A)
8866 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8867 0);
8868 break;
8869
8870 case elfcpp::R_ARM_MOVW_ABS_NC:
8871 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8872 output_section))
8873 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8874 0, thumb_bit,
8875 check_overflow);
8876 break;
8877
8878 case elfcpp::R_ARM_MOVT_ABS:
8879 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8880 output_section))
8881 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8882 break;
8883
8884 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8885 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8886 output_section))
8887 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8888 0, thumb_bit, false);
8889 break;
8890
8891 case elfcpp::R_ARM_THM_MOVT_ABS:
8892 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8893 output_section))
8894 reloc_status = Arm_relocate_functions::thm_movt(view, object,
8895 psymval, 0);
8896 break;
8897
8898 case elfcpp::R_ARM_MOVW_PREL_NC:
8899 case elfcpp::R_ARM_MOVW_BREL_NC:
8900 case elfcpp::R_ARM_MOVW_BREL:
8901 reloc_status =
8902 Arm_relocate_functions::movw(view, object, psymval,
8903 relative_address_base, thumb_bit,
8904 check_overflow);
8905 break;
8906
8907 case elfcpp::R_ARM_MOVT_PREL:
8908 case elfcpp::R_ARM_MOVT_BREL:
8909 reloc_status =
8910 Arm_relocate_functions::movt(view, object, psymval,
8911 relative_address_base);
8912 break;
8913
8914 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8915 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8916 case elfcpp::R_ARM_THM_MOVW_BREL:
8917 reloc_status =
8918 Arm_relocate_functions::thm_movw(view, object, psymval,
8919 relative_address_base,
8920 thumb_bit, check_overflow);
8921 break;
8922
8923 case elfcpp::R_ARM_THM_MOVT_PREL:
8924 case elfcpp::R_ARM_THM_MOVT_BREL:
8925 reloc_status =
8926 Arm_relocate_functions::thm_movt(view, object, psymval,
8927 relative_address_base);
8928 break;
8929
8930 case elfcpp::R_ARM_REL32:
8931 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8932 address, thumb_bit);
8933 break;
8934
8935 case elfcpp::R_ARM_THM_ABS5:
8936 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8937 output_section))
8938 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
8939 break;
8940
8941 // Thumb long branches.
8942 case elfcpp::R_ARM_THM_CALL:
8943 case elfcpp::R_ARM_THM_XPC22:
8944 case elfcpp::R_ARM_THM_JUMP24:
8945 reloc_status =
8946 Arm_relocate_functions::thumb_branch_common(
8947 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8948 thumb_bit, is_weakly_undefined_without_plt);
8949 break;
8950
8951 case elfcpp::R_ARM_GOTOFF32:
8952 {
8953 Arm_address got_origin;
8954 got_origin = target->got_plt_section()->address();
8955 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8956 got_origin, thumb_bit);
8957 }
8958 break;
8959
8960 case elfcpp::R_ARM_BASE_PREL:
8961 gold_assert(gsym != NULL);
8962 reloc_status =
8963 Arm_relocate_functions::base_prel(view, sym_origin, address);
8964 break;
8965
8966 case elfcpp::R_ARM_BASE_ABS:
8967 {
8968 if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8969 output_section))
8970 break;
8971
8972 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
8973 }
8974 break;
8975
8976 case elfcpp::R_ARM_GOT_BREL:
8977 gold_assert(have_got_offset);
8978 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
8979 break;
8980
8981 case elfcpp::R_ARM_GOT_PREL:
8982 gold_assert(have_got_offset);
8983 // Get the address origin for GOT PLT, which is allocated right
8984 // after the GOT section, to calculate an absolute address of
8985 // the symbol GOT entry (got_origin + got_offset).
8986 Arm_address got_origin;
8987 got_origin = target->got_plt_section()->address();
8988 reloc_status = Arm_relocate_functions::got_prel(view,
8989 got_origin + got_offset,
8990 address);
8991 break;
8992
8993 case elfcpp::R_ARM_PLT32:
8994 case elfcpp::R_ARM_CALL:
8995 case elfcpp::R_ARM_JUMP24:
8996 case elfcpp::R_ARM_XPC25:
8997 gold_assert(gsym == NULL
8998 || gsym->has_plt_offset()
8999 || gsym->final_value_is_known()
9000 || (gsym->is_defined()
9001 && !gsym->is_from_dynobj()
9002 && !gsym->is_preemptible()));
9003 reloc_status =
9004 Arm_relocate_functions::arm_branch_common(
9005 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9006 thumb_bit, is_weakly_undefined_without_plt);
9007 break;
9008
9009 case elfcpp::R_ARM_THM_JUMP19:
9010 reloc_status =
9011 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9012 thumb_bit);
9013 break;
9014
9015 case elfcpp::R_ARM_THM_JUMP6:
9016 reloc_status =
9017 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9018 break;
9019
9020 case elfcpp::R_ARM_THM_JUMP8:
9021 reloc_status =
9022 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9023 break;
9024
9025 case elfcpp::R_ARM_THM_JUMP11:
9026 reloc_status =
9027 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9028 break;
9029
9030 case elfcpp::R_ARM_PREL31:
9031 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9032 address, thumb_bit);
9033 break;
9034
9035 case elfcpp::R_ARM_V4BX:
9036 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9037 {
9038 const bool is_v4bx_interworking =
9039 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9040 reloc_status =
9041 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9042 is_v4bx_interworking);
9043 }
9044 break;
9045
9046 case elfcpp::R_ARM_THM_PC8:
9047 reloc_status =
9048 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9049 break;
9050
9051 case elfcpp::R_ARM_THM_PC12:
9052 reloc_status =
9053 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9054 break;
9055
9056 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9057 reloc_status =
9058 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9059 thumb_bit);
9060 break;
9061
9062 case elfcpp::R_ARM_ALU_PC_G0_NC:
9063 case elfcpp::R_ARM_ALU_PC_G0:
9064 case elfcpp::R_ARM_ALU_PC_G1_NC:
9065 case elfcpp::R_ARM_ALU_PC_G1:
9066 case elfcpp::R_ARM_ALU_PC_G2:
9067 case elfcpp::R_ARM_ALU_SB_G0_NC:
9068 case elfcpp::R_ARM_ALU_SB_G0:
9069 case elfcpp::R_ARM_ALU_SB_G1_NC:
9070 case elfcpp::R_ARM_ALU_SB_G1:
9071 case elfcpp::R_ARM_ALU_SB_G2:
9072 reloc_status =
9073 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9074 reloc_property->group_index(),
9075 relative_address_base,
9076 thumb_bit, check_overflow);
9077 break;
9078
9079 case elfcpp::R_ARM_LDR_PC_G0:
9080 case elfcpp::R_ARM_LDR_PC_G1:
9081 case elfcpp::R_ARM_LDR_PC_G2:
9082 case elfcpp::R_ARM_LDR_SB_G0:
9083 case elfcpp::R_ARM_LDR_SB_G1:
9084 case elfcpp::R_ARM_LDR_SB_G2:
9085 reloc_status =
9086 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9087 reloc_property->group_index(),
9088 relative_address_base);
9089 break;
9090
9091 case elfcpp::R_ARM_LDRS_PC_G0:
9092 case elfcpp::R_ARM_LDRS_PC_G1:
9093 case elfcpp::R_ARM_LDRS_PC_G2:
9094 case elfcpp::R_ARM_LDRS_SB_G0:
9095 case elfcpp::R_ARM_LDRS_SB_G1:
9096 case elfcpp::R_ARM_LDRS_SB_G2:
9097 reloc_status =
9098 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9099 reloc_property->group_index(),
9100 relative_address_base);
9101 break;
9102
9103 case elfcpp::R_ARM_LDC_PC_G0:
9104 case elfcpp::R_ARM_LDC_PC_G1:
9105 case elfcpp::R_ARM_LDC_PC_G2:
9106 case elfcpp::R_ARM_LDC_SB_G0:
9107 case elfcpp::R_ARM_LDC_SB_G1:
9108 case elfcpp::R_ARM_LDC_SB_G2:
9109 reloc_status =
9110 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9111 reloc_property->group_index(),
9112 relative_address_base);
9113 break;
9114
9115 // These are initial tls relocs, which are expected when
9116 // linking.
9117 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9118 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9119 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9120 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9121 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9122 reloc_status =
9123 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9124 view, address, view_size);
9125 break;
9126
9127 // The known and unknown unsupported and/or deprecated relocations.
9128 case elfcpp::R_ARM_PC24:
9129 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9130 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9131 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9132 default:
9133 // Just silently leave the method. We should get an appropriate error
9134 // message in the scan methods.
9135 break;
9136 }
9137
9138 // Report any errors.
9139 switch (reloc_status)
9140 {
9141 case Arm_relocate_functions::STATUS_OKAY:
9142 break;
9143 case Arm_relocate_functions::STATUS_OVERFLOW:
9144 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9145 _("relocation overflow in %s"),
9146 reloc_property->name().c_str());
9147 break;
9148 case Arm_relocate_functions::STATUS_BAD_RELOC:
9149 gold_error_at_location(
9150 relinfo,
9151 relnum,
9152 rel.get_r_offset(),
9153 _("unexpected opcode while processing relocation %s"),
9154 reloc_property->name().c_str());
9155 break;
9156 default:
9157 gold_unreachable();
9158 }
9159
9160 return true;
9161 }
9162
9163 // Perform a TLS relocation.
9164
9165 template<bool big_endian>
9166 inline typename Arm_relocate_functions<big_endian>::Status
9167 Target_arm<big_endian>::Relocate::relocate_tls(
9168 const Relocate_info<32, big_endian>* relinfo,
9169 Target_arm<big_endian>* target,
9170 size_t relnum,
9171 const elfcpp::Rel<32, big_endian>& rel,
9172 unsigned int r_type,
9173 const Sized_symbol<32>* gsym,
9174 const Symbol_value<32>* psymval,
9175 unsigned char* view,
9176 elfcpp::Elf_types<32>::Elf_Addr address,
9177 section_size_type /*view_size*/ )
9178 {
9179 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9180 typedef Relocate_functions<32, big_endian> RelocFuncs;
9181 Output_segment* tls_segment = relinfo->layout->tls_segment();
9182
9183 const Sized_relobj<32, big_endian>* object = relinfo->object;
9184
9185 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9186
9187 const bool is_final = (gsym == NULL
9188 ? !parameters->options().shared()
9189 : gsym->final_value_is_known());
9190 const tls::Tls_optimization optimized_type
9191 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9192 switch (r_type)
9193 {
9194 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9195 {
9196 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9197 unsigned int got_offset;
9198 if (gsym != NULL)
9199 {
9200 gold_assert(gsym->has_got_offset(got_type));
9201 got_offset = gsym->got_offset(got_type) - target->got_size();
9202 }
9203 else
9204 {
9205 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9206 gold_assert(object->local_has_got_offset(r_sym, got_type));
9207 got_offset = (object->local_got_offset(r_sym, got_type)
9208 - target->got_size());
9209 }
9210 if (optimized_type == tls::TLSOPT_NONE)
9211 {
9212 Arm_address got_entry =
9213 target->got_plt_section()->address() + got_offset;
9214
9215 // Relocate the field with the PC relative offset of the pair of
9216 // GOT entries.
9217 RelocFuncs::pcrel32(view, got_entry, address);
9218 return ArmRelocFuncs::STATUS_OKAY;
9219 }
9220 }
9221 break;
9222
9223 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9224 if (optimized_type == tls::TLSOPT_NONE)
9225 {
9226 // Relocate the field with the offset of the GOT entry for
9227 // the module index.
9228 unsigned int got_offset;
9229 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9230 - target->got_size());
9231 Arm_address got_entry =
9232 target->got_plt_section()->address() + got_offset;
9233
9234 // Relocate the field with the PC relative offset of the pair of
9235 // GOT entries.
9236 RelocFuncs::pcrel32(view, got_entry, address);
9237 return ArmRelocFuncs::STATUS_OKAY;
9238 }
9239 break;
9240
9241 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9242 RelocFuncs::rel32(view, value);
9243 return ArmRelocFuncs::STATUS_OKAY;
9244
9245 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9246 if (optimized_type == tls::TLSOPT_NONE)
9247 {
9248 // Relocate the field with the offset of the GOT entry for
9249 // the tp-relative offset of the symbol.
9250 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9251 unsigned int got_offset;
9252 if (gsym != NULL)
9253 {
9254 gold_assert(gsym->has_got_offset(got_type));
9255 got_offset = gsym->got_offset(got_type);
9256 }
9257 else
9258 {
9259 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9260 gold_assert(object->local_has_got_offset(r_sym, got_type));
9261 got_offset = object->local_got_offset(r_sym, got_type);
9262 }
9263
9264 // All GOT offsets are relative to the end of the GOT.
9265 got_offset -= target->got_size();
9266
9267 Arm_address got_entry =
9268 target->got_plt_section()->address() + got_offset;
9269
9270 // Relocate the field with the PC relative offset of the GOT entry.
9271 RelocFuncs::pcrel32(view, got_entry, address);
9272 return ArmRelocFuncs::STATUS_OKAY;
9273 }
9274 break;
9275
9276 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9277 // If we're creating a shared library, a dynamic relocation will
9278 // have been created for this location, so do not apply it now.
9279 if (!parameters->options().shared())
9280 {
9281 gold_assert(tls_segment != NULL);
9282
9283 // $tp points to the TCB, which is followed by the TLS, so we
9284 // need to add TCB size to the offset.
9285 Arm_address aligned_tcb_size =
9286 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9287 RelocFuncs::rel32(view, value + aligned_tcb_size);
9288
9289 }
9290 return ArmRelocFuncs::STATUS_OKAY;
9291
9292 default:
9293 gold_unreachable();
9294 }
9295
9296 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9297 _("unsupported reloc %u"),
9298 r_type);
9299 return ArmRelocFuncs::STATUS_BAD_RELOC;
9300 }
9301
9302 // Relocate section data.
9303
9304 template<bool big_endian>
9305 void
9306 Target_arm<big_endian>::relocate_section(
9307 const Relocate_info<32, big_endian>* relinfo,
9308 unsigned int sh_type,
9309 const unsigned char* prelocs,
9310 size_t reloc_count,
9311 Output_section* output_section,
9312 bool needs_special_offset_handling,
9313 unsigned char* view,
9314 Arm_address address,
9315 section_size_type view_size,
9316 const Reloc_symbol_changes* reloc_symbol_changes)
9317 {
9318 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9319 gold_assert(sh_type == elfcpp::SHT_REL);
9320
9321 // See if we are relocating a relaxed input section. If so, the view
9322 // covers the whole output section and we need to adjust accordingly.
9323 if (needs_special_offset_handling)
9324 {
9325 const Output_relaxed_input_section* poris =
9326 output_section->find_relaxed_input_section(relinfo->object,
9327 relinfo->data_shndx);
9328 if (poris != NULL)
9329 {
9330 Arm_address section_address = poris->address();
9331 section_size_type section_size = poris->data_size();
9332
9333 gold_assert((section_address >= address)
9334 && ((section_address + section_size)
9335 <= (address + view_size)));
9336
9337 off_t offset = section_address - address;
9338 view += offset;
9339 address += offset;
9340 view_size = section_size;
9341 }
9342 }
9343
9344 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9345 Arm_relocate>(
9346 relinfo,
9347 this,
9348 prelocs,
9349 reloc_count,
9350 output_section,
9351 needs_special_offset_handling,
9352 view,
9353 address,
9354 view_size,
9355 reloc_symbol_changes);
9356 }
9357
9358 // Return the size of a relocation while scanning during a relocatable
9359 // link.
9360
9361 template<bool big_endian>
9362 unsigned int
9363 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9364 unsigned int r_type,
9365 Relobj* object)
9366 {
9367 r_type = get_real_reloc_type(r_type);
9368 const Arm_reloc_property* arp =
9369 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9370 if (arp != NULL)
9371 return arp->size();
9372 else
9373 {
9374 std::string reloc_name =
9375 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9376 gold_error(_("%s: unexpected %s in object file"),
9377 object->name().c_str(), reloc_name.c_str());
9378 return 0;
9379 }
9380 }
9381
9382 // Scan the relocs during a relocatable link.
9383
9384 template<bool big_endian>
9385 void
9386 Target_arm<big_endian>::scan_relocatable_relocs(
9387 Symbol_table* symtab,
9388 Layout* layout,
9389 Sized_relobj<32, big_endian>* object,
9390 unsigned int data_shndx,
9391 unsigned int sh_type,
9392 const unsigned char* prelocs,
9393 size_t reloc_count,
9394 Output_section* output_section,
9395 bool needs_special_offset_handling,
9396 size_t local_symbol_count,
9397 const unsigned char* plocal_symbols,
9398 Relocatable_relocs* rr)
9399 {
9400 gold_assert(sh_type == elfcpp::SHT_REL);
9401
9402 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9403 Relocatable_size_for_reloc> Scan_relocatable_relocs;
9404
9405 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9406 Scan_relocatable_relocs>(
9407 symtab,
9408 layout,
9409 object,
9410 data_shndx,
9411 prelocs,
9412 reloc_count,
9413 output_section,
9414 needs_special_offset_handling,
9415 local_symbol_count,
9416 plocal_symbols,
9417 rr);
9418 }
9419
9420 // Relocate a section during a relocatable link.
9421
9422 template<bool big_endian>
9423 void
9424 Target_arm<big_endian>::relocate_for_relocatable(
9425 const Relocate_info<32, big_endian>* relinfo,
9426 unsigned int sh_type,
9427 const unsigned char* prelocs,
9428 size_t reloc_count,
9429 Output_section* output_section,
9430 off_t offset_in_output_section,
9431 const Relocatable_relocs* rr,
9432 unsigned char* view,
9433 Arm_address view_address,
9434 section_size_type view_size,
9435 unsigned char* reloc_view,
9436 section_size_type reloc_view_size)
9437 {
9438 gold_assert(sh_type == elfcpp::SHT_REL);
9439
9440 gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
9441 relinfo,
9442 prelocs,
9443 reloc_count,
9444 output_section,
9445 offset_in_output_section,
9446 rr,
9447 view,
9448 view_address,
9449 view_size,
9450 reloc_view,
9451 reloc_view_size);
9452 }
9453
9454 // Perform target-specific processing in a relocatable link. This is
9455 // only used if we use the relocation strategy RELOC_SPECIAL.
9456
9457 template<bool big_endian>
9458 void
9459 Target_arm<big_endian>::relocate_special_relocatable(
9460 const Relocate_info<32, big_endian>* relinfo,
9461 unsigned int sh_type,
9462 const unsigned char* preloc_in,
9463 size_t relnum,
9464 Output_section* output_section,
9465 off_t offset_in_output_section,
9466 unsigned char* view,
9467 elfcpp::Elf_types<32>::Elf_Addr view_address,
9468 section_size_type,
9469 unsigned char* preloc_out)
9470 {
9471 // We can only handle REL type relocation sections.
9472 gold_assert(sh_type == elfcpp::SHT_REL);
9473
9474 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9475 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9476 Reltype_write;
9477 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9478
9479 const Arm_relobj<big_endian>* object =
9480 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9481 const unsigned int local_count = object->local_symbol_count();
9482
9483 Reltype reloc(preloc_in);
9484 Reltype_write reloc_write(preloc_out);
9485
9486 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9487 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9488 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9489
9490 const Arm_reloc_property* arp =
9491 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9492 gold_assert(arp != NULL);
9493
9494 // Get the new symbol index.
9495 // We only use RELOC_SPECIAL strategy in local relocations.
9496 gold_assert(r_sym < local_count);
9497
9498 // We are adjusting a section symbol. We need to find
9499 // the symbol table index of the section symbol for
9500 // the output section corresponding to input section
9501 // in which this symbol is defined.
9502 bool is_ordinary;
9503 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9504 gold_assert(is_ordinary);
9505 Output_section* os = object->output_section(shndx);
9506 gold_assert(os != NULL);
9507 gold_assert(os->needs_symtab_index());
9508 unsigned int new_symndx = os->symtab_index();
9509
9510 // Get the new offset--the location in the output section where
9511 // this relocation should be applied.
9512
9513 Arm_address offset = reloc.get_r_offset();
9514 Arm_address new_offset;
9515 if (offset_in_output_section != invalid_address)
9516 new_offset = offset + offset_in_output_section;
9517 else
9518 {
9519 section_offset_type sot_offset =
9520 convert_types<section_offset_type, Arm_address>(offset);
9521 section_offset_type new_sot_offset =
9522 output_section->output_offset(object, relinfo->data_shndx,
9523 sot_offset);
9524 gold_assert(new_sot_offset != -1);
9525 new_offset = new_sot_offset;
9526 }
9527
9528 // In an object file, r_offset is an offset within the section.
9529 // In an executable or dynamic object, generated by
9530 // --emit-relocs, r_offset is an absolute address.
9531 if (!parameters->options().relocatable())
9532 {
9533 new_offset += view_address;
9534 if (offset_in_output_section != invalid_address)
9535 new_offset -= offset_in_output_section;
9536 }
9537
9538 reloc_write.put_r_offset(new_offset);
9539 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9540
9541 // Handle the reloc addend.
9542 // The relocation uses a section symbol in the input file.
9543 // We are adjusting it to use a section symbol in the output
9544 // file. The input section symbol refers to some address in
9545 // the input section. We need the relocation in the output
9546 // file to refer to that same address. This adjustment to
9547 // the addend is the same calculation we use for a simple
9548 // absolute relocation for the input section symbol.
9549
9550 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9551
9552 // Handle THUMB bit.
9553 Symbol_value<32> symval;
9554 Arm_address thumb_bit =
9555 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9556 if (thumb_bit != 0
9557 && arp->uses_thumb_bit()
9558 && ((psymval->value(object, 0) & 1) != 0))
9559 {
9560 Arm_address stripped_value =
9561 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9562 symval.set_output_value(stripped_value);
9563 psymval = &symval;
9564 }
9565
9566 unsigned char* paddend = view + offset;
9567 typename Arm_relocate_functions<big_endian>::Status reloc_status =
9568 Arm_relocate_functions<big_endian>::STATUS_OKAY;
9569 switch (r_type)
9570 {
9571 case elfcpp::R_ARM_ABS8:
9572 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9573 psymval);
9574 break;
9575
9576 case elfcpp::R_ARM_ABS12:
9577 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9578 psymval);
9579 break;
9580
9581 case elfcpp::R_ARM_ABS16:
9582 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9583 psymval);
9584 break;
9585
9586 case elfcpp::R_ARM_THM_ABS5:
9587 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9588 object,
9589 psymval);
9590 break;
9591
9592 case elfcpp::R_ARM_MOVW_ABS_NC:
9593 case elfcpp::R_ARM_MOVW_PREL_NC:
9594 case elfcpp::R_ARM_MOVW_BREL_NC:
9595 case elfcpp::R_ARM_MOVW_BREL:
9596 reloc_status = Arm_relocate_functions<big_endian>::movw(
9597 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9598 break;
9599
9600 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9601 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9602 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9603 case elfcpp::R_ARM_THM_MOVW_BREL:
9604 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9605 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9606 break;
9607
9608 case elfcpp::R_ARM_THM_CALL:
9609 case elfcpp::R_ARM_THM_XPC22:
9610 case elfcpp::R_ARM_THM_JUMP24:
9611 reloc_status =
9612 Arm_relocate_functions<big_endian>::thumb_branch_common(
9613 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9614 false);
9615 break;
9616
9617 case elfcpp::R_ARM_PLT32:
9618 case elfcpp::R_ARM_CALL:
9619 case elfcpp::R_ARM_JUMP24:
9620 case elfcpp::R_ARM_XPC25:
9621 reloc_status =
9622 Arm_relocate_functions<big_endian>::arm_branch_common(
9623 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9624 false);
9625 break;
9626
9627 case elfcpp::R_ARM_THM_JUMP19:
9628 reloc_status =
9629 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9630 psymval, 0, thumb_bit);
9631 break;
9632
9633 case elfcpp::R_ARM_THM_JUMP6:
9634 reloc_status =
9635 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9636 0);
9637 break;
9638
9639 case elfcpp::R_ARM_THM_JUMP8:
9640 reloc_status =
9641 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9642 0);
9643 break;
9644
9645 case elfcpp::R_ARM_THM_JUMP11:
9646 reloc_status =
9647 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9648 0);
9649 break;
9650
9651 case elfcpp::R_ARM_PREL31:
9652 reloc_status =
9653 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9654 thumb_bit);
9655 break;
9656
9657 case elfcpp::R_ARM_THM_PC8:
9658 reloc_status =
9659 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9660 0);
9661 break;
9662
9663 case elfcpp::R_ARM_THM_PC12:
9664 reloc_status =
9665 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9666 0);
9667 break;
9668
9669 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9670 reloc_status =
9671 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9672 0, thumb_bit);
9673 break;
9674
9675 // These relocation truncate relocation results so we cannot handle them
9676 // in a relocatable link.
9677 case elfcpp::R_ARM_MOVT_ABS:
9678 case elfcpp::R_ARM_THM_MOVT_ABS:
9679 case elfcpp::R_ARM_MOVT_PREL:
9680 case elfcpp::R_ARM_MOVT_BREL:
9681 case elfcpp::R_ARM_THM_MOVT_PREL:
9682 case elfcpp::R_ARM_THM_MOVT_BREL:
9683 case elfcpp::R_ARM_ALU_PC_G0_NC:
9684 case elfcpp::R_ARM_ALU_PC_G0:
9685 case elfcpp::R_ARM_ALU_PC_G1_NC:
9686 case elfcpp::R_ARM_ALU_PC_G1:
9687 case elfcpp::R_ARM_ALU_PC_G2:
9688 case elfcpp::R_ARM_ALU_SB_G0_NC:
9689 case elfcpp::R_ARM_ALU_SB_G0:
9690 case elfcpp::R_ARM_ALU_SB_G1_NC:
9691 case elfcpp::R_ARM_ALU_SB_G1:
9692 case elfcpp::R_ARM_ALU_SB_G2:
9693 case elfcpp::R_ARM_LDR_PC_G0:
9694 case elfcpp::R_ARM_LDR_PC_G1:
9695 case elfcpp::R_ARM_LDR_PC_G2:
9696 case elfcpp::R_ARM_LDR_SB_G0:
9697 case elfcpp::R_ARM_LDR_SB_G1:
9698 case elfcpp::R_ARM_LDR_SB_G2:
9699 case elfcpp::R_ARM_LDRS_PC_G0:
9700 case elfcpp::R_ARM_LDRS_PC_G1:
9701 case elfcpp::R_ARM_LDRS_PC_G2:
9702 case elfcpp::R_ARM_LDRS_SB_G0:
9703 case elfcpp::R_ARM_LDRS_SB_G1:
9704 case elfcpp::R_ARM_LDRS_SB_G2:
9705 case elfcpp::R_ARM_LDC_PC_G0:
9706 case elfcpp::R_ARM_LDC_PC_G1:
9707 case elfcpp::R_ARM_LDC_PC_G2:
9708 case elfcpp::R_ARM_LDC_SB_G0:
9709 case elfcpp::R_ARM_LDC_SB_G1:
9710 case elfcpp::R_ARM_LDC_SB_G2:
9711 gold_error(_("cannot handle %s in a relocatable link"),
9712 arp->name().c_str());
9713 break;
9714
9715 default:
9716 gold_unreachable();
9717 }
9718
9719 // Report any errors.
9720 switch (reloc_status)
9721 {
9722 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9723 break;
9724 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9725 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9726 _("relocation overflow in %s"),
9727 arp->name().c_str());
9728 break;
9729 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9730 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9731 _("unexpected opcode while processing relocation %s"),
9732 arp->name().c_str());
9733 break;
9734 default:
9735 gold_unreachable();
9736 }
9737 }
9738
9739 // Return the value to use for a dynamic symbol which requires special
9740 // treatment. This is how we support equality comparisons of function
9741 // pointers across shared library boundaries, as described in the
9742 // processor specific ABI supplement.
9743
9744 template<bool big_endian>
9745 uint64_t
9746 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9747 {
9748 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9749 return this->plt_section()->address() + gsym->plt_offset();
9750 }
9751
9752 // Map platform-specific relocs to real relocs
9753 //
9754 template<bool big_endian>
9755 unsigned int
9756 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9757 {
9758 switch (r_type)
9759 {
9760 case elfcpp::R_ARM_TARGET1:
9761 // This is either R_ARM_ABS32 or R_ARM_REL32;
9762 return elfcpp::R_ARM_ABS32;
9763
9764 case elfcpp::R_ARM_TARGET2:
9765 // This can be any reloc type but ususally is R_ARM_GOT_PREL
9766 return elfcpp::R_ARM_GOT_PREL;
9767
9768 default:
9769 return r_type;
9770 }
9771 }
9772
9773 // Whether if two EABI versions V1 and V2 are compatible.
9774
9775 template<bool big_endian>
9776 bool
9777 Target_arm<big_endian>::are_eabi_versions_compatible(
9778 elfcpp::Elf_Word v1,
9779 elfcpp::Elf_Word v2)
9780 {
9781 // v4 and v5 are the same spec before and after it was released,
9782 // so allow mixing them.
9783 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9784 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9785 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9786 return true;
9787
9788 return v1 == v2;
9789 }
9790
9791 // Combine FLAGS from an input object called NAME and the processor-specific
9792 // flags in the ELF header of the output. Much of this is adapted from the
9793 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9794 // in bfd/elf32-arm.c.
9795
9796 template<bool big_endian>
9797 void
9798 Target_arm<big_endian>::merge_processor_specific_flags(
9799 const std::string& name,
9800 elfcpp::Elf_Word flags)
9801 {
9802 if (this->are_processor_specific_flags_set())
9803 {
9804 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9805
9806 // Nothing to merge if flags equal to those in output.
9807 if (flags == out_flags)
9808 return;
9809
9810 // Complain about various flag mismatches.
9811 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9812 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9813 if (!this->are_eabi_versions_compatible(version1, version2)
9814 && parameters->options().warn_mismatch())
9815 gold_error(_("Source object %s has EABI version %d but output has "
9816 "EABI version %d."),
9817 name.c_str(),
9818 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9819 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9820 }
9821 else
9822 {
9823 // If the input is the default architecture and had the default
9824 // flags then do not bother setting the flags for the output
9825 // architecture, instead allow future merges to do this. If no
9826 // future merges ever set these flags then they will retain their
9827 // uninitialised values, which surprise surprise, correspond
9828 // to the default values.
9829 if (flags == 0)
9830 return;
9831
9832 // This is the first time, just copy the flags.
9833 // We only copy the EABI version for now.
9834 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
9835 }
9836 }
9837
9838 // Adjust ELF file header.
9839 template<bool big_endian>
9840 void
9841 Target_arm<big_endian>::do_adjust_elf_header(
9842 unsigned char* view,
9843 int len) const
9844 {
9845 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
9846
9847 elfcpp::Ehdr<32, big_endian> ehdr(view);
9848 unsigned char e_ident[elfcpp::EI_NIDENT];
9849 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
9850
9851 if (elfcpp::arm_eabi_version(this->processor_specific_flags())
9852 == elfcpp::EF_ARM_EABI_UNKNOWN)
9853 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
9854 else
9855 e_ident[elfcpp::EI_OSABI] = 0;
9856 e_ident[elfcpp::EI_ABIVERSION] = 0;
9857
9858 // FIXME: Do EF_ARM_BE8 adjustment.
9859
9860 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9861 oehdr.put_e_ident(e_ident);
9862 }
9863
9864 // do_make_elf_object to override the same function in the base class.
9865 // We need to use a target-specific sub-class of Sized_relobj<32, big_endian>
9866 // to store ARM specific information. Hence we need to have our own
9867 // ELF object creation.
9868
9869 template<bool big_endian>
9870 Object*
9871 Target_arm<big_endian>::do_make_elf_object(
9872 const std::string& name,
9873 Input_file* input_file,
9874 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9875 {
9876 int et = ehdr.get_e_type();
9877 if (et == elfcpp::ET_REL)
9878 {
9879 Arm_relobj<big_endian>* obj =
9880 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9881 obj->setup();
9882 return obj;
9883 }
9884 else if (et == elfcpp::ET_DYN)
9885 {
9886 Sized_dynobj<32, big_endian>* obj =
9887 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9888 obj->setup();
9889 return obj;
9890 }
9891 else
9892 {
9893 gold_error(_("%s: unsupported ELF file type %d"),
9894 name.c_str(), et);
9895 return NULL;
9896 }
9897 }
9898
9899 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9900 // Returns -1 if no architecture could be read.
9901 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9902
9903 template<bool big_endian>
9904 int
9905 Target_arm<big_endian>::get_secondary_compatible_arch(
9906 const Attributes_section_data* pasd)
9907 {
9908 const Object_attribute* known_attributes =
9909 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9910
9911 // Note: the tag and its argument below are uleb128 values, though
9912 // currently-defined values fit in one byte for each.
9913 const std::string& sv =
9914 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9915 if (sv.size() == 2
9916 && sv.data()[0] == elfcpp::Tag_CPU_arch
9917 && (sv.data()[1] & 128) != 128)
9918 return sv.data()[1];
9919
9920 // This tag is "safely ignorable", so don't complain if it looks funny.
9921 return -1;
9922 }
9923
9924 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
9925 // The tag is removed if ARCH is -1.
9926 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
9927
9928 template<bool big_endian>
9929 void
9930 Target_arm<big_endian>::set_secondary_compatible_arch(
9931 Attributes_section_data* pasd,
9932 int arch)
9933 {
9934 Object_attribute* known_attributes =
9935 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9936
9937 if (arch == -1)
9938 {
9939 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
9940 return;
9941 }
9942
9943 // Note: the tag and its argument below are uleb128 values, though
9944 // currently-defined values fit in one byte for each.
9945 char sv[3];
9946 sv[0] = elfcpp::Tag_CPU_arch;
9947 gold_assert(arch != 0);
9948 sv[1] = arch;
9949 sv[2] = '\0';
9950
9951 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
9952 }
9953
9954 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
9955 // into account.
9956 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
9957
9958 template<bool big_endian>
9959 int
9960 Target_arm<big_endian>::tag_cpu_arch_combine(
9961 const char* name,
9962 int oldtag,
9963 int* secondary_compat_out,
9964 int newtag,
9965 int secondary_compat)
9966 {
9967 #define T(X) elfcpp::TAG_CPU_ARCH_##X
9968 static const int v6t2[] =
9969 {
9970 T(V6T2), // PRE_V4.
9971 T(V6T2), // V4.
9972 T(V6T2), // V4T.
9973 T(V6T2), // V5T.
9974 T(V6T2), // V5TE.
9975 T(V6T2), // V5TEJ.
9976 T(V6T2), // V6.
9977 T(V7), // V6KZ.
9978 T(V6T2) // V6T2.
9979 };
9980 static const int v6k[] =
9981 {
9982 T(V6K), // PRE_V4.
9983 T(V6K), // V4.
9984 T(V6K), // V4T.
9985 T(V6K), // V5T.
9986 T(V6K), // V5TE.
9987 T(V6K), // V5TEJ.
9988 T(V6K), // V6.
9989 T(V6KZ), // V6KZ.
9990 T(V7), // V6T2.
9991 T(V6K) // V6K.
9992 };
9993 static const int v7[] =
9994 {
9995 T(V7), // PRE_V4.
9996 T(V7), // V4.
9997 T(V7), // V4T.
9998 T(V7), // V5T.
9999 T(V7), // V5TE.
10000 T(V7), // V5TEJ.
10001 T(V7), // V6.
10002 T(V7), // V6KZ.
10003 T(V7), // V6T2.
10004 T(V7), // V6K.
10005 T(V7) // V7.
10006 };
10007 static const int v6_m[] =
10008 {
10009 -1, // PRE_V4.
10010 -1, // V4.
10011 T(V6K), // V4T.
10012 T(V6K), // V5T.
10013 T(V6K), // V5TE.
10014 T(V6K), // V5TEJ.
10015 T(V6K), // V6.
10016 T(V6KZ), // V6KZ.
10017 T(V7), // V6T2.
10018 T(V6K), // V6K.
10019 T(V7), // V7.
10020 T(V6_M) // V6_M.
10021 };
10022 static const int v6s_m[] =
10023 {
10024 -1, // PRE_V4.
10025 -1, // V4.
10026 T(V6K), // V4T.
10027 T(V6K), // V5T.
10028 T(V6K), // V5TE.
10029 T(V6K), // V5TEJ.
10030 T(V6K), // V6.
10031 T(V6KZ), // V6KZ.
10032 T(V7), // V6T2.
10033 T(V6K), // V6K.
10034 T(V7), // V7.
10035 T(V6S_M), // V6_M.
10036 T(V6S_M) // V6S_M.
10037 };
10038 static const int v7e_m[] =
10039 {
10040 -1, // PRE_V4.
10041 -1, // V4.
10042 T(V7E_M), // V4T.
10043 T(V7E_M), // V5T.
10044 T(V7E_M), // V5TE.
10045 T(V7E_M), // V5TEJ.
10046 T(V7E_M), // V6.
10047 T(V7E_M), // V6KZ.
10048 T(V7E_M), // V6T2.
10049 T(V7E_M), // V6K.
10050 T(V7E_M), // V7.
10051 T(V7E_M), // V6_M.
10052 T(V7E_M), // V6S_M.
10053 T(V7E_M) // V7E_M.
10054 };
10055 static const int v4t_plus_v6_m[] =
10056 {
10057 -1, // PRE_V4.
10058 -1, // V4.
10059 T(V4T), // V4T.
10060 T(V5T), // V5T.
10061 T(V5TE), // V5TE.
10062 T(V5TEJ), // V5TEJ.
10063 T(V6), // V6.
10064 T(V6KZ), // V6KZ.
10065 T(V6T2), // V6T2.
10066 T(V6K), // V6K.
10067 T(V7), // V7.
10068 T(V6_M), // V6_M.
10069 T(V6S_M), // V6S_M.
10070 T(V7E_M), // V7E_M.
10071 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10072 };
10073 static const int* comb[] =
10074 {
10075 v6t2,
10076 v6k,
10077 v7,
10078 v6_m,
10079 v6s_m,
10080 v7e_m,
10081 // Pseudo-architecture.
10082 v4t_plus_v6_m
10083 };
10084
10085 // Check we've not got a higher architecture than we know about.
10086
10087 if (oldtag >= elfcpp::MAX_TAG_CPU_ARCH || newtag >= elfcpp::MAX_TAG_CPU_ARCH)
10088 {
10089 gold_error(_("%s: unknown CPU architecture"), name);
10090 return -1;
10091 }
10092
10093 // Override old tag if we have a Tag_also_compatible_with on the output.
10094
10095 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10096 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10097 oldtag = T(V4T_PLUS_V6_M);
10098
10099 // And override the new tag if we have a Tag_also_compatible_with on the
10100 // input.
10101
10102 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10103 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10104 newtag = T(V4T_PLUS_V6_M);
10105
10106 // Architectures before V6KZ add features monotonically.
10107 int tagh = std::max(oldtag, newtag);
10108 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10109 return tagh;
10110
10111 int tagl = std::min(oldtag, newtag);
10112 int result = comb[tagh - T(V6T2)][tagl];
10113
10114 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10115 // as the canonical version.
10116 if (result == T(V4T_PLUS_V6_M))
10117 {
10118 result = T(V4T);
10119 *secondary_compat_out = T(V6_M);
10120 }
10121 else
10122 *secondary_compat_out = -1;
10123
10124 if (result == -1)
10125 {
10126 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10127 name, oldtag, newtag);
10128 return -1;
10129 }
10130
10131 return result;
10132 #undef T
10133 }
10134
10135 // Helper to print AEABI enum tag value.
10136
10137 template<bool big_endian>
10138 std::string
10139 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10140 {
10141 static const char* aeabi_enum_names[] =
10142 { "", "variable-size", "32-bit", "" };
10143 const size_t aeabi_enum_names_size =
10144 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10145
10146 if (value < aeabi_enum_names_size)
10147 return std::string(aeabi_enum_names[value]);
10148 else
10149 {
10150 char buffer[100];
10151 sprintf(buffer, "<unknown value %u>", value);
10152 return std::string(buffer);
10153 }
10154 }
10155
10156 // Return the string value to store in TAG_CPU_name.
10157
10158 template<bool big_endian>
10159 std::string
10160 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10161 {
10162 static const char* name_table[] = {
10163 // These aren't real CPU names, but we can't guess
10164 // that from the architecture version alone.
10165 "Pre v4",
10166 "ARM v4",
10167 "ARM v4T",
10168 "ARM v5T",
10169 "ARM v5TE",
10170 "ARM v5TEJ",
10171 "ARM v6",
10172 "ARM v6KZ",
10173 "ARM v6T2",
10174 "ARM v6K",
10175 "ARM v7",
10176 "ARM v6-M",
10177 "ARM v6S-M",
10178 "ARM v7E-M"
10179 };
10180 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10181
10182 if (value < name_table_size)
10183 return std::string(name_table[value]);
10184 else
10185 {
10186 char buffer[100];
10187 sprintf(buffer, "<unknown CPU value %u>", value);
10188 return std::string(buffer);
10189 }
10190 }
10191
10192 // Merge object attributes from input file called NAME with those of the
10193 // output. The input object attributes are in the object pointed by PASD.
10194
10195 template<bool big_endian>
10196 void
10197 Target_arm<big_endian>::merge_object_attributes(
10198 const char* name,
10199 const Attributes_section_data* pasd)
10200 {
10201 // Return if there is no attributes section data.
10202 if (pasd == NULL)
10203 return;
10204
10205 // If output has no object attributes, just copy.
10206 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10207 if (this->attributes_section_data_ == NULL)
10208 {
10209 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10210 Object_attribute* out_attr =
10211 this->attributes_section_data_->known_attributes(vendor);
10212
10213 // We do not output objects with Tag_MPextension_use_legacy - we move
10214 // the attribute's value to Tag_MPextension_use. */
10215 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10216 {
10217 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10218 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10219 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10220 {
10221 gold_error(_("%s has both the current and legacy "
10222 "Tag_MPextension_use attributes"),
10223 name);
10224 }
10225
10226 out_attr[elfcpp::Tag_MPextension_use] =
10227 out_attr[elfcpp::Tag_MPextension_use_legacy];
10228 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10229 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10230 }
10231
10232 return;
10233 }
10234
10235 const Object_attribute* in_attr = pasd->known_attributes(vendor);
10236 Object_attribute* out_attr =
10237 this->attributes_section_data_->known_attributes(vendor);
10238
10239 // This needs to happen before Tag_ABI_FP_number_model is merged. */
10240 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10241 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10242 {
10243 // Ignore mismatches if the object doesn't use floating point. */
10244 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10245 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10246 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10247 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10248 && parameters->options().warn_mismatch())
10249 gold_error(_("%s uses VFP register arguments, output does not"),
10250 name);
10251 }
10252
10253 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10254 {
10255 // Merge this attribute with existing attributes.
10256 switch (i)
10257 {
10258 case elfcpp::Tag_CPU_raw_name:
10259 case elfcpp::Tag_CPU_name:
10260 // These are merged after Tag_CPU_arch.
10261 break;
10262
10263 case elfcpp::Tag_ABI_optimization_goals:
10264 case elfcpp::Tag_ABI_FP_optimization_goals:
10265 // Use the first value seen.
10266 break;
10267
10268 case elfcpp::Tag_CPU_arch:
10269 {
10270 unsigned int saved_out_attr = out_attr->int_value();
10271 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10272 int secondary_compat =
10273 this->get_secondary_compatible_arch(pasd);
10274 int secondary_compat_out =
10275 this->get_secondary_compatible_arch(
10276 this->attributes_section_data_);
10277 out_attr[i].set_int_value(
10278 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10279 &secondary_compat_out,
10280 in_attr[i].int_value(),
10281 secondary_compat));
10282 this->set_secondary_compatible_arch(this->attributes_section_data_,
10283 secondary_compat_out);
10284
10285 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10286 if (out_attr[i].int_value() == saved_out_attr)
10287 ; // Leave the names alone.
10288 else if (out_attr[i].int_value() == in_attr[i].int_value())
10289 {
10290 // The output architecture has been changed to match the
10291 // input architecture. Use the input names.
10292 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10293 in_attr[elfcpp::Tag_CPU_name].string_value());
10294 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10295 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10296 }
10297 else
10298 {
10299 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10300 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10301 }
10302
10303 // If we still don't have a value for Tag_CPU_name,
10304 // make one up now. Tag_CPU_raw_name remains blank.
10305 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10306 {
10307 const std::string cpu_name =
10308 this->tag_cpu_name_value(out_attr[i].int_value());
10309 // FIXME: If we see an unknown CPU, this will be set
10310 // to "<unknown CPU n>", where n is the attribute value.
10311 // This is different from BFD, which leaves the name alone.
10312 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10313 }
10314 }
10315 break;
10316
10317 case elfcpp::Tag_ARM_ISA_use:
10318 case elfcpp::Tag_THUMB_ISA_use:
10319 case elfcpp::Tag_WMMX_arch:
10320 case elfcpp::Tag_Advanced_SIMD_arch:
10321 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10322 case elfcpp::Tag_ABI_FP_rounding:
10323 case elfcpp::Tag_ABI_FP_exceptions:
10324 case elfcpp::Tag_ABI_FP_user_exceptions:
10325 case elfcpp::Tag_ABI_FP_number_model:
10326 case elfcpp::Tag_VFP_HP_extension:
10327 case elfcpp::Tag_CPU_unaligned_access:
10328 case elfcpp::Tag_T2EE_use:
10329 case elfcpp::Tag_Virtualization_use:
10330 case elfcpp::Tag_MPextension_use:
10331 // Use the largest value specified.
10332 if (in_attr[i].int_value() > out_attr[i].int_value())
10333 out_attr[i].set_int_value(in_attr[i].int_value());
10334 break;
10335
10336 case elfcpp::Tag_ABI_align8_preserved:
10337 case elfcpp::Tag_ABI_PCS_RO_data:
10338 // Use the smallest value specified.
10339 if (in_attr[i].int_value() < out_attr[i].int_value())
10340 out_attr[i].set_int_value(in_attr[i].int_value());
10341 break;
10342
10343 case elfcpp::Tag_ABI_align8_needed:
10344 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10345 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10346 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10347 == 0)))
10348 {
10349 // This error message should be enabled once all non-conformant
10350 // binaries in the toolchain have had the attributes set
10351 // properly.
10352 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10353 // name);
10354 }
10355 // Fall through.
10356 case elfcpp::Tag_ABI_FP_denormal:
10357 case elfcpp::Tag_ABI_PCS_GOT_use:
10358 {
10359 // These tags have 0 = don't care, 1 = strong requirement,
10360 // 2 = weak requirement.
10361 static const int order_021[3] = {0, 2, 1};
10362
10363 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10364 // value if greater than 2 (for future-proofing).
10365 if ((in_attr[i].int_value() > 2
10366 && in_attr[i].int_value() > out_attr[i].int_value())
10367 || (in_attr[i].int_value() <= 2
10368 && out_attr[i].int_value() <= 2
10369 && (order_021[in_attr[i].int_value()]
10370 > order_021[out_attr[i].int_value()])))
10371 out_attr[i].set_int_value(in_attr[i].int_value());
10372 }
10373 break;
10374
10375 case elfcpp::Tag_CPU_arch_profile:
10376 if (out_attr[i].int_value() != in_attr[i].int_value())
10377 {
10378 // 0 will merge with anything.
10379 // 'A' and 'S' merge to 'A'.
10380 // 'R' and 'S' merge to 'R'.
10381 // 'M' and 'A|R|S' is an error.
10382 if (out_attr[i].int_value() == 0
10383 || (out_attr[i].int_value() == 'S'
10384 && (in_attr[i].int_value() == 'A'
10385 || in_attr[i].int_value() == 'R')))
10386 out_attr[i].set_int_value(in_attr[i].int_value());
10387 else if (in_attr[i].int_value() == 0
10388 || (in_attr[i].int_value() == 'S'
10389 && (out_attr[i].int_value() == 'A'
10390 || out_attr[i].int_value() == 'R')))
10391 ; // Do nothing.
10392 else if (parameters->options().warn_mismatch())
10393 {
10394 gold_error
10395 (_("conflicting architecture profiles %c/%c"),
10396 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10397 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10398 }
10399 }
10400 break;
10401 case elfcpp::Tag_VFP_arch:
10402 {
10403 static const struct
10404 {
10405 int ver;
10406 int regs;
10407 } vfp_versions[7] =
10408 {
10409 {0, 0},
10410 {1, 16},
10411 {2, 16},
10412 {3, 32},
10413 {3, 16},
10414 {4, 32},
10415 {4, 16}
10416 };
10417
10418 // Values greater than 6 aren't defined, so just pick the
10419 // biggest.
10420 if (in_attr[i].int_value() > 6
10421 && in_attr[i].int_value() > out_attr[i].int_value())
10422 {
10423 *out_attr = *in_attr;
10424 break;
10425 }
10426 // The output uses the superset of input features
10427 // (ISA version) and registers.
10428 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10429 vfp_versions[out_attr[i].int_value()].ver);
10430 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10431 vfp_versions[out_attr[i].int_value()].regs);
10432 // This assumes all possible supersets are also a valid
10433 // options.
10434 int newval;
10435 for (newval = 6; newval > 0; newval--)
10436 {
10437 if (regs == vfp_versions[newval].regs
10438 && ver == vfp_versions[newval].ver)
10439 break;
10440 }
10441 out_attr[i].set_int_value(newval);
10442 }
10443 break;
10444 case elfcpp::Tag_PCS_config:
10445 if (out_attr[i].int_value() == 0)
10446 out_attr[i].set_int_value(in_attr[i].int_value());
10447 else if (in_attr[i].int_value() != 0
10448 && out_attr[i].int_value() != 0
10449 && parameters->options().warn_mismatch())
10450 {
10451 // It's sometimes ok to mix different configs, so this is only
10452 // a warning.
10453 gold_warning(_("%s: conflicting platform configuration"), name);
10454 }
10455 break;
10456 case elfcpp::Tag_ABI_PCS_R9_use:
10457 if (in_attr[i].int_value() != out_attr[i].int_value()
10458 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10459 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10460 && parameters->options().warn_mismatch())
10461 {
10462 gold_error(_("%s: conflicting use of R9"), name);
10463 }
10464 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10465 out_attr[i].set_int_value(in_attr[i].int_value());
10466 break;
10467 case elfcpp::Tag_ABI_PCS_RW_data:
10468 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10469 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10470 != elfcpp::AEABI_R9_SB)
10471 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10472 != elfcpp::AEABI_R9_unused)
10473 && parameters->options().warn_mismatch())
10474 {
10475 gold_error(_("%s: SB relative addressing conflicts with use "
10476 "of R9"),
10477 name);
10478 }
10479 // Use the smallest value specified.
10480 if (in_attr[i].int_value() < out_attr[i].int_value())
10481 out_attr[i].set_int_value(in_attr[i].int_value());
10482 break;
10483 case elfcpp::Tag_ABI_PCS_wchar_t:
10484 if (out_attr[i].int_value()
10485 && in_attr[i].int_value()
10486 && out_attr[i].int_value() != in_attr[i].int_value()
10487 && parameters->options().warn_mismatch()
10488 && parameters->options().wchar_size_warning())
10489 {
10490 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10491 "use %u-byte wchar_t; use of wchar_t values "
10492 "across objects may fail"),
10493 name, in_attr[i].int_value(),
10494 out_attr[i].int_value());
10495 }
10496 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10497 out_attr[i].set_int_value(in_attr[i].int_value());
10498 break;
10499 case elfcpp::Tag_ABI_enum_size:
10500 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10501 {
10502 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10503 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10504 {
10505 // The existing object is compatible with anything.
10506 // Use whatever requirements the new object has.
10507 out_attr[i].set_int_value(in_attr[i].int_value());
10508 }
10509 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10510 && out_attr[i].int_value() != in_attr[i].int_value()
10511 && parameters->options().warn_mismatch()
10512 && parameters->options().enum_size_warning())
10513 {
10514 unsigned int in_value = in_attr[i].int_value();
10515 unsigned int out_value = out_attr[i].int_value();
10516 gold_warning(_("%s uses %s enums yet the output is to use "
10517 "%s enums; use of enum values across objects "
10518 "may fail"),
10519 name,
10520 this->aeabi_enum_name(in_value).c_str(),
10521 this->aeabi_enum_name(out_value).c_str());
10522 }
10523 }
10524 break;
10525 case elfcpp::Tag_ABI_VFP_args:
10526 // Aready done.
10527 break;
10528 case elfcpp::Tag_ABI_WMMX_args:
10529 if (in_attr[i].int_value() != out_attr[i].int_value()
10530 && parameters->options().warn_mismatch())
10531 {
10532 gold_error(_("%s uses iWMMXt register arguments, output does "
10533 "not"),
10534 name);
10535 }
10536 break;
10537 case Object_attribute::Tag_compatibility:
10538 // Merged in target-independent code.
10539 break;
10540 case elfcpp::Tag_ABI_HardFP_use:
10541 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10542 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10543 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10544 out_attr[i].set_int_value(3);
10545 else if (in_attr[i].int_value() > out_attr[i].int_value())
10546 out_attr[i].set_int_value(in_attr[i].int_value());
10547 break;
10548 case elfcpp::Tag_ABI_FP_16bit_format:
10549 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10550 {
10551 if (in_attr[i].int_value() != out_attr[i].int_value()
10552 && parameters->options().warn_mismatch())
10553 gold_error(_("fp16 format mismatch between %s and output"),
10554 name);
10555 }
10556 if (in_attr[i].int_value() != 0)
10557 out_attr[i].set_int_value(in_attr[i].int_value());
10558 break;
10559
10560 case elfcpp::Tag_DIV_use:
10561 // This tag is set to zero if we can use UDIV and SDIV in Thumb
10562 // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10563 // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10564 // CPU. We will merge as follows: If the input attribute's value
10565 // is one then the output attribute's value remains unchanged. If
10566 // the input attribute's value is zero or two then if the output
10567 // attribute's value is one the output value is set to the input
10568 // value, otherwise the output value must be the same as the
10569 // inputs. */
10570 if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10571 {
10572 if (in_attr[i].int_value() != out_attr[i].int_value())
10573 {
10574 gold_error(_("DIV usage mismatch between %s and output"),
10575 name);
10576 }
10577 }
10578
10579 if (in_attr[i].int_value() != 1)
10580 out_attr[i].set_int_value(in_attr[i].int_value());
10581
10582 break;
10583
10584 case elfcpp::Tag_MPextension_use_legacy:
10585 // We don't output objects with Tag_MPextension_use_legacy - we
10586 // move the value to Tag_MPextension_use.
10587 if (in_attr[i].int_value() != 0
10588 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10589 {
10590 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10591 != in_attr[i].int_value())
10592 {
10593 gold_error(_("%s has has both the current and legacy "
10594 "Tag_MPextension_use attributes"),
10595 name);
10596 }
10597 }
10598
10599 if (in_attr[i].int_value()
10600 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10601 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10602
10603 break;
10604
10605 case elfcpp::Tag_nodefaults:
10606 // This tag is set if it exists, but the value is unused (and is
10607 // typically zero). We don't actually need to do anything here -
10608 // the merge happens automatically when the type flags are merged
10609 // below.
10610 break;
10611 case elfcpp::Tag_also_compatible_with:
10612 // Already done in Tag_CPU_arch.
10613 break;
10614 case elfcpp::Tag_conformance:
10615 // Keep the attribute if it matches. Throw it away otherwise.
10616 // No attribute means no claim to conform.
10617 if (in_attr[i].string_value() != out_attr[i].string_value())
10618 out_attr[i].set_string_value("");
10619 break;
10620
10621 default:
10622 {
10623 const char* err_object = NULL;
10624
10625 // The "known_obj_attributes" table does contain some undefined
10626 // attributes. Ensure that there are unused.
10627 if (out_attr[i].int_value() != 0
10628 || out_attr[i].string_value() != "")
10629 err_object = "output";
10630 else if (in_attr[i].int_value() != 0
10631 || in_attr[i].string_value() != "")
10632 err_object = name;
10633
10634 if (err_object != NULL
10635 && parameters->options().warn_mismatch())
10636 {
10637 // Attribute numbers >=64 (mod 128) can be safely ignored.
10638 if ((i & 127) < 64)
10639 gold_error(_("%s: unknown mandatory EABI object attribute "
10640 "%d"),
10641 err_object, i);
10642 else
10643 gold_warning(_("%s: unknown EABI object attribute %d"),
10644 err_object, i);
10645 }
10646
10647 // Only pass on attributes that match in both inputs.
10648 if (!in_attr[i].matches(out_attr[i]))
10649 {
10650 out_attr[i].set_int_value(0);
10651 out_attr[i].set_string_value("");
10652 }
10653 }
10654 }
10655
10656 // If out_attr was copied from in_attr then it won't have a type yet.
10657 if (in_attr[i].type() && !out_attr[i].type())
10658 out_attr[i].set_type(in_attr[i].type());
10659 }
10660
10661 // Merge Tag_compatibility attributes and any common GNU ones.
10662 this->attributes_section_data_->merge(name, pasd);
10663
10664 // Check for any attributes not known on ARM.
10665 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10666 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10667 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10668 Other_attributes* out_other_attributes =
10669 this->attributes_section_data_->other_attributes(vendor);
10670 Other_attributes::iterator out_iter = out_other_attributes->begin();
10671
10672 while (in_iter != in_other_attributes->end()
10673 || out_iter != out_other_attributes->end())
10674 {
10675 const char* err_object = NULL;
10676 int err_tag = 0;
10677
10678 // The tags for each list are in numerical order.
10679 // If the tags are equal, then merge.
10680 if (out_iter != out_other_attributes->end()
10681 && (in_iter == in_other_attributes->end()
10682 || in_iter->first > out_iter->first))
10683 {
10684 // This attribute only exists in output. We can't merge, and we
10685 // don't know what the tag means, so delete it.
10686 err_object = "output";
10687 err_tag = out_iter->first;
10688 int saved_tag = out_iter->first;
10689 delete out_iter->second;
10690 out_other_attributes->erase(out_iter);
10691 out_iter = out_other_attributes->upper_bound(saved_tag);
10692 }
10693 else if (in_iter != in_other_attributes->end()
10694 && (out_iter != out_other_attributes->end()
10695 || in_iter->first < out_iter->first))
10696 {
10697 // This attribute only exists in input. We can't merge, and we
10698 // don't know what the tag means, so ignore it.
10699 err_object = name;
10700 err_tag = in_iter->first;
10701 ++in_iter;
10702 }
10703 else // The tags are equal.
10704 {
10705 // As present, all attributes in the list are unknown, and
10706 // therefore can't be merged meaningfully.
10707 err_object = "output";
10708 err_tag = out_iter->first;
10709
10710 // Only pass on attributes that match in both inputs.
10711 if (!in_iter->second->matches(*(out_iter->second)))
10712 {
10713 // No match. Delete the attribute.
10714 int saved_tag = out_iter->first;
10715 delete out_iter->second;
10716 out_other_attributes->erase(out_iter);
10717 out_iter = out_other_attributes->upper_bound(saved_tag);
10718 }
10719 else
10720 {
10721 // Matched. Keep the attribute and move to the next.
10722 ++out_iter;
10723 ++in_iter;
10724 }
10725 }
10726
10727 if (err_object && parameters->options().warn_mismatch())
10728 {
10729 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10730 if ((err_tag & 127) < 64)
10731 {
10732 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10733 err_object, err_tag);
10734 }
10735 else
10736 {
10737 gold_warning(_("%s: unknown EABI object attribute %d"),
10738 err_object, err_tag);
10739 }
10740 }
10741 }
10742 }
10743
10744 // Stub-generation methods for Target_arm.
10745
10746 // Make a new Arm_input_section object.
10747
10748 template<bool big_endian>
10749 Arm_input_section<big_endian>*
10750 Target_arm<big_endian>::new_arm_input_section(
10751 Relobj* relobj,
10752 unsigned int shndx)
10753 {
10754 Section_id sid(relobj, shndx);
10755
10756 Arm_input_section<big_endian>* arm_input_section =
10757 new Arm_input_section<big_endian>(relobj, shndx);
10758 arm_input_section->init();
10759
10760 // Register new Arm_input_section in map for look-up.
10761 std::pair<typename Arm_input_section_map::iterator, bool> ins =
10762 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10763
10764 // Make sure that it we have not created another Arm_input_section
10765 // for this input section already.
10766 gold_assert(ins.second);
10767
10768 return arm_input_section;
10769 }
10770
10771 // Find the Arm_input_section object corresponding to the SHNDX-th input
10772 // section of RELOBJ.
10773
10774 template<bool big_endian>
10775 Arm_input_section<big_endian>*
10776 Target_arm<big_endian>::find_arm_input_section(
10777 Relobj* relobj,
10778 unsigned int shndx) const
10779 {
10780 Section_id sid(relobj, shndx);
10781 typename Arm_input_section_map::const_iterator p =
10782 this->arm_input_section_map_.find(sid);
10783 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10784 }
10785
10786 // Make a new stub table.
10787
10788 template<bool big_endian>
10789 Stub_table<big_endian>*
10790 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10791 {
10792 Stub_table<big_endian>* stub_table =
10793 new Stub_table<big_endian>(owner);
10794 this->stub_tables_.push_back(stub_table);
10795
10796 stub_table->set_address(owner->address() + owner->data_size());
10797 stub_table->set_file_offset(owner->offset() + owner->data_size());
10798 stub_table->finalize_data_size();
10799
10800 return stub_table;
10801 }
10802
10803 // Scan a relocation for stub generation.
10804
10805 template<bool big_endian>
10806 void
10807 Target_arm<big_endian>::scan_reloc_for_stub(
10808 const Relocate_info<32, big_endian>* relinfo,
10809 unsigned int r_type,
10810 const Sized_symbol<32>* gsym,
10811 unsigned int r_sym,
10812 const Symbol_value<32>* psymval,
10813 elfcpp::Elf_types<32>::Elf_Swxword addend,
10814 Arm_address address)
10815 {
10816 typedef typename Target_arm<big_endian>::Relocate Relocate;
10817
10818 const Arm_relobj<big_endian>* arm_relobj =
10819 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10820
10821 bool target_is_thumb;
10822 Symbol_value<32> symval;
10823 if (gsym != NULL)
10824 {
10825 // This is a global symbol. Determine if we use PLT and if the
10826 // final target is THUMB.
10827 if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type)))
10828 {
10829 // This uses a PLT, change the symbol value.
10830 symval.set_output_value(this->plt_section()->address()
10831 + gsym->plt_offset());
10832 psymval = &symval;
10833 target_is_thumb = false;
10834 }
10835 else if (gsym->is_undefined())
10836 // There is no need to generate a stub symbol is undefined.
10837 return;
10838 else
10839 {
10840 target_is_thumb =
10841 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
10842 || (gsym->type() == elfcpp::STT_FUNC
10843 && !gsym->is_undefined()
10844 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
10845 }
10846 }
10847 else
10848 {
10849 // This is a local symbol. Determine if the final target is THUMB.
10850 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
10851 }
10852
10853 // Strip LSB if this points to a THUMB target.
10854 const Arm_reloc_property* reloc_property =
10855 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10856 gold_assert(reloc_property != NULL);
10857 if (target_is_thumb
10858 && reloc_property->uses_thumb_bit()
10859 && ((psymval->value(arm_relobj, 0) & 1) != 0))
10860 {
10861 Arm_address stripped_value =
10862 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
10863 symval.set_output_value(stripped_value);
10864 psymval = &symval;
10865 }
10866
10867 // Get the symbol value.
10868 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
10869
10870 // Owing to pipelining, the PC relative branches below actually skip
10871 // two instructions when the branch offset is 0.
10872 Arm_address destination;
10873 switch (r_type)
10874 {
10875 case elfcpp::R_ARM_CALL:
10876 case elfcpp::R_ARM_JUMP24:
10877 case elfcpp::R_ARM_PLT32:
10878 // ARM branches.
10879 destination = value + addend + 8;
10880 break;
10881 case elfcpp::R_ARM_THM_CALL:
10882 case elfcpp::R_ARM_THM_XPC22:
10883 case elfcpp::R_ARM_THM_JUMP24:
10884 case elfcpp::R_ARM_THM_JUMP19:
10885 // THUMB branches.
10886 destination = value + addend + 4;
10887 break;
10888 default:
10889 gold_unreachable();
10890 }
10891
10892 Reloc_stub* stub = NULL;
10893 Stub_type stub_type =
10894 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
10895 target_is_thumb);
10896 if (stub_type != arm_stub_none)
10897 {
10898 // Try looking up an existing stub from a stub table.
10899 Stub_table<big_endian>* stub_table =
10900 arm_relobj->stub_table(relinfo->data_shndx);
10901 gold_assert(stub_table != NULL);
10902
10903 // Locate stub by destination.
10904 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
10905
10906 // Create a stub if there is not one already
10907 stub = stub_table->find_reloc_stub(stub_key);
10908 if (stub == NULL)
10909 {
10910 // create a new stub and add it to stub table.
10911 stub = this->stub_factory().make_reloc_stub(stub_type);
10912 stub_table->add_reloc_stub(stub, stub_key);
10913 }
10914
10915 // Record the destination address.
10916 stub->set_destination_address(destination
10917 | (target_is_thumb ? 1 : 0));
10918 }
10919
10920 // For Cortex-A8, we need to record a relocation at 4K page boundary.
10921 if (this->fix_cortex_a8_
10922 && (r_type == elfcpp::R_ARM_THM_JUMP24
10923 || r_type == elfcpp::R_ARM_THM_JUMP19
10924 || r_type == elfcpp::R_ARM_THM_CALL
10925 || r_type == elfcpp::R_ARM_THM_XPC22)
10926 && (address & 0xfffU) == 0xffeU)
10927 {
10928 // Found a candidate. Note we haven't checked the destination is
10929 // within 4K here: if we do so (and don't create a record) we can't
10930 // tell that a branch should have been relocated when scanning later.
10931 this->cortex_a8_relocs_info_[address] =
10932 new Cortex_a8_reloc(stub, r_type,
10933 destination | (target_is_thumb ? 1 : 0));
10934 }
10935 }
10936
10937 // This function scans a relocation sections for stub generation.
10938 // The template parameter Relocate must be a class type which provides
10939 // a single function, relocate(), which implements the machine
10940 // specific part of a relocation.
10941
10942 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
10943 // SHT_REL or SHT_RELA.
10944
10945 // PRELOCS points to the relocation data. RELOC_COUNT is the number
10946 // of relocs. OUTPUT_SECTION is the output section.
10947 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
10948 // mapped to output offsets.
10949
10950 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
10951 // VIEW_SIZE is the size. These refer to the input section, unless
10952 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
10953 // the output section.
10954
10955 template<bool big_endian>
10956 template<int sh_type>
10957 void inline
10958 Target_arm<big_endian>::scan_reloc_section_for_stubs(
10959 const Relocate_info<32, big_endian>* relinfo,
10960 const unsigned char* prelocs,
10961 size_t reloc_count,
10962 Output_section* output_section,
10963 bool needs_special_offset_handling,
10964 const unsigned char* view,
10965 elfcpp::Elf_types<32>::Elf_Addr view_address,
10966 section_size_type)
10967 {
10968 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
10969 const int reloc_size =
10970 Reloc_types<sh_type, 32, big_endian>::reloc_size;
10971
10972 Arm_relobj<big_endian>* arm_object =
10973 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10974 unsigned int local_count = arm_object->local_symbol_count();
10975
10976 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
10977
10978 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
10979 {
10980 Reltype reloc(prelocs);
10981
10982 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10983 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10984 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10985
10986 r_type = this->get_real_reloc_type(r_type);
10987
10988 // Only a few relocation types need stubs.
10989 if ((r_type != elfcpp::R_ARM_CALL)
10990 && (r_type != elfcpp::R_ARM_JUMP24)
10991 && (r_type != elfcpp::R_ARM_PLT32)
10992 && (r_type != elfcpp::R_ARM_THM_CALL)
10993 && (r_type != elfcpp::R_ARM_THM_XPC22)
10994 && (r_type != elfcpp::R_ARM_THM_JUMP24)
10995 && (r_type != elfcpp::R_ARM_THM_JUMP19)
10996 && (r_type != elfcpp::R_ARM_V4BX))
10997 continue;
10998
10999 section_offset_type offset =
11000 convert_to_section_size_type(reloc.get_r_offset());
11001
11002 if (needs_special_offset_handling)
11003 {
11004 offset = output_section->output_offset(relinfo->object,
11005 relinfo->data_shndx,
11006 offset);
11007 if (offset == -1)
11008 continue;
11009 }
11010
11011 // Create a v4bx stub if --fix-v4bx-interworking is used.
11012 if (r_type == elfcpp::R_ARM_V4BX)
11013 {
11014 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11015 {
11016 // Get the BX instruction.
11017 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11018 const Valtype* wv =
11019 reinterpret_cast<const Valtype*>(view + offset);
11020 elfcpp::Elf_types<32>::Elf_Swxword insn =
11021 elfcpp::Swap<32, big_endian>::readval(wv);
11022 const uint32_t reg = (insn & 0xf);
11023
11024 if (reg < 0xf)
11025 {
11026 // Try looking up an existing stub from a stub table.
11027 Stub_table<big_endian>* stub_table =
11028 arm_object->stub_table(relinfo->data_shndx);
11029 gold_assert(stub_table != NULL);
11030
11031 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11032 {
11033 // create a new stub and add it to stub table.
11034 Arm_v4bx_stub* stub =
11035 this->stub_factory().make_arm_v4bx_stub(reg);
11036 gold_assert(stub != NULL);
11037 stub_table->add_arm_v4bx_stub(stub);
11038 }
11039 }
11040 }
11041 continue;
11042 }
11043
11044 // Get the addend.
11045 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11046 elfcpp::Elf_types<32>::Elf_Swxword addend =
11047 stub_addend_reader(r_type, view + offset, reloc);
11048
11049 const Sized_symbol<32>* sym;
11050
11051 Symbol_value<32> symval;
11052 const Symbol_value<32> *psymval;
11053 bool is_defined_in_discarded_section;
11054 unsigned int shndx;
11055 if (r_sym < local_count)
11056 {
11057 sym = NULL;
11058 psymval = arm_object->local_symbol(r_sym);
11059
11060 // If the local symbol belongs to a section we are discarding,
11061 // and that section is a debug section, try to find the
11062 // corresponding kept section and map this symbol to its
11063 // counterpart in the kept section. The symbol must not
11064 // correspond to a section we are folding.
11065 bool is_ordinary;
11066 shndx = psymval->input_shndx(&is_ordinary);
11067 is_defined_in_discarded_section =
11068 (is_ordinary
11069 && shndx != elfcpp::SHN_UNDEF
11070 && !arm_object->is_section_included(shndx)
11071 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11072
11073 // We need to compute the would-be final value of this local
11074 // symbol.
11075 if (!is_defined_in_discarded_section)
11076 {
11077 typedef Sized_relobj<32, big_endian> ObjType;
11078 typename ObjType::Compute_final_local_value_status status =
11079 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11080 relinfo->symtab);
11081 if (status == ObjType::CFLV_OK)
11082 {
11083 // Currently we cannot handle a branch to a target in
11084 // a merged section. If this is the case, issue an error
11085 // and also free the merge symbol value.
11086 if (!symval.has_output_value())
11087 {
11088 const std::string& section_name =
11089 arm_object->section_name(shndx);
11090 arm_object->error(_("cannot handle branch to local %u "
11091 "in a merged section %s"),
11092 r_sym, section_name.c_str());
11093 }
11094 psymval = &symval;
11095 }
11096 else
11097 {
11098 // We cannot determine the final value.
11099 continue;
11100 }
11101 }
11102 }
11103 else
11104 {
11105 const Symbol* gsym;
11106 gsym = arm_object->global_symbol(r_sym);
11107 gold_assert(gsym != NULL);
11108 if (gsym->is_forwarder())
11109 gsym = relinfo->symtab->resolve_forwards(gsym);
11110
11111 sym = static_cast<const Sized_symbol<32>*>(gsym);
11112 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11113 symval.set_output_symtab_index(sym->symtab_index());
11114 else
11115 symval.set_no_output_symtab_entry();
11116
11117 // We need to compute the would-be final value of this global
11118 // symbol.
11119 const Symbol_table* symtab = relinfo->symtab;
11120 const Sized_symbol<32>* sized_symbol =
11121 symtab->get_sized_symbol<32>(gsym);
11122 Symbol_table::Compute_final_value_status status;
11123 Arm_address value =
11124 symtab->compute_final_value<32>(sized_symbol, &status);
11125
11126 // Skip this if the symbol has not output section.
11127 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11128 continue;
11129 symval.set_output_value(value);
11130
11131 if (gsym->type() == elfcpp::STT_TLS)
11132 symval.set_is_tls_symbol();
11133 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11134 symval.set_is_ifunc_symbol();
11135 psymval = &symval;
11136
11137 is_defined_in_discarded_section =
11138 (gsym->is_defined_in_discarded_section()
11139 && gsym->is_undefined());
11140 shndx = 0;
11141 }
11142
11143 Symbol_value<32> symval2;
11144 if (is_defined_in_discarded_section)
11145 {
11146 if (comdat_behavior == CB_UNDETERMINED)
11147 {
11148 std::string name = arm_object->section_name(relinfo->data_shndx);
11149 comdat_behavior = get_comdat_behavior(name.c_str());
11150 }
11151 if (comdat_behavior == CB_PRETEND)
11152 {
11153 // FIXME: This case does not work for global symbols.
11154 // We have no place to store the original section index.
11155 // Fortunately this does not matter for comdat sections,
11156 // only for sections explicitly discarded by a linker
11157 // script.
11158 bool found;
11159 typename elfcpp::Elf_types<32>::Elf_Addr value =
11160 arm_object->map_to_kept_section(shndx, &found);
11161 if (found)
11162 symval2.set_output_value(value + psymval->input_value());
11163 else
11164 symval2.set_output_value(0);
11165 }
11166 else
11167 {
11168 if (comdat_behavior == CB_WARNING)
11169 gold_warning_at_location(relinfo, i, offset,
11170 _("relocation refers to discarded "
11171 "section"));
11172 symval2.set_output_value(0);
11173 }
11174 symval2.set_no_output_symtab_entry();
11175 psymval = &symval2;
11176 }
11177
11178 // If symbol is a section symbol, we don't know the actual type of
11179 // destination. Give up.
11180 if (psymval->is_section_symbol())
11181 continue;
11182
11183 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11184 addend, view_address + offset);
11185 }
11186 }
11187
11188 // Scan an input section for stub generation.
11189
11190 template<bool big_endian>
11191 void
11192 Target_arm<big_endian>::scan_section_for_stubs(
11193 const Relocate_info<32, big_endian>* relinfo,
11194 unsigned int sh_type,
11195 const unsigned char* prelocs,
11196 size_t reloc_count,
11197 Output_section* output_section,
11198 bool needs_special_offset_handling,
11199 const unsigned char* view,
11200 Arm_address view_address,
11201 section_size_type view_size)
11202 {
11203 if (sh_type == elfcpp::SHT_REL)
11204 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11205 relinfo,
11206 prelocs,
11207 reloc_count,
11208 output_section,
11209 needs_special_offset_handling,
11210 view,
11211 view_address,
11212 view_size);
11213 else if (sh_type == elfcpp::SHT_RELA)
11214 // We do not support RELA type relocations yet. This is provided for
11215 // completeness.
11216 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11217 relinfo,
11218 prelocs,
11219 reloc_count,
11220 output_section,
11221 needs_special_offset_handling,
11222 view,
11223 view_address,
11224 view_size);
11225 else
11226 gold_unreachable();
11227 }
11228
11229 // Group input sections for stub generation.
11230 //
11231 // We goup input sections in an output sections so that the total size,
11232 // including any padding space due to alignment is smaller than GROUP_SIZE
11233 // unless the only input section in group is bigger than GROUP_SIZE already.
11234 // Then an ARM stub table is created to follow the last input section
11235 // in group. For each group an ARM stub table is created an is placed
11236 // after the last group. If STUB_ALWATS_AFTER_BRANCH is false, we further
11237 // extend the group after the stub table.
11238
11239 template<bool big_endian>
11240 void
11241 Target_arm<big_endian>::group_sections(
11242 Layout* layout,
11243 section_size_type group_size,
11244 bool stubs_always_after_branch,
11245 const Task* task)
11246 {
11247 // Group input sections and insert stub table
11248 Layout::Section_list section_list;
11249 layout->get_allocated_sections(&section_list);
11250 for (Layout::Section_list::const_iterator p = section_list.begin();
11251 p != section_list.end();
11252 ++p)
11253 {
11254 Arm_output_section<big_endian>* output_section =
11255 Arm_output_section<big_endian>::as_arm_output_section(*p);
11256 output_section->group_sections(group_size, stubs_always_after_branch,
11257 this, task);
11258 }
11259 }
11260
11261 // Relaxation hook. This is where we do stub generation.
11262
11263 template<bool big_endian>
11264 bool
11265 Target_arm<big_endian>::do_relax(
11266 int pass,
11267 const Input_objects* input_objects,
11268 Symbol_table* symtab,
11269 Layout* layout,
11270 const Task* task)
11271 {
11272 // No need to generate stubs if this is a relocatable link.
11273 gold_assert(!parameters->options().relocatable());
11274
11275 // If this is the first pass, we need to group input sections into
11276 // stub groups.
11277 bool done_exidx_fixup = false;
11278 typedef typename Stub_table_list::iterator Stub_table_iterator;
11279 if (pass == 1)
11280 {
11281 // Determine the stub group size. The group size is the absolute
11282 // value of the parameter --stub-group-size. If --stub-group-size
11283 // is passed a negative value, we restict stubs to be always after
11284 // the stubbed branches.
11285 int32_t stub_group_size_param =
11286 parameters->options().stub_group_size();
11287 bool stubs_always_after_branch = stub_group_size_param < 0;
11288 section_size_type stub_group_size = abs(stub_group_size_param);
11289
11290 if (stub_group_size == 1)
11291 {
11292 // Default value.
11293 // Thumb branch range is +-4MB has to be used as the default
11294 // maximum size (a given section can contain both ARM and Thumb
11295 // code, so the worst case has to be taken into account). If we are
11296 // fixing cortex-a8 errata, the branch range has to be even smaller,
11297 // since wide conditional branch has a range of +-1MB only.
11298 //
11299 // This value is 48K less than that, which allows for 4096
11300 // 12-byte stubs. If we exceed that, then we will fail to link.
11301 // The user will have to relink with an explicit group size
11302 // option.
11303 stub_group_size = 4145152;
11304 }
11305
11306 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11307 // page as the first half of a 32-bit branch straddling two 4K pages.
11308 // This is a crude way of enforcing that. In addition, long conditional
11309 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11310 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11311 // cortex-A8 stubs from long conditional branches.
11312 if (this->fix_cortex_a8_)
11313 {
11314 stubs_always_after_branch = true;
11315 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11316 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11317 }
11318
11319 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11320
11321 // Also fix .ARM.exidx section coverage.
11322 Arm_output_section<big_endian>* exidx_output_section = NULL;
11323 for (Layout::Section_list::const_iterator p =
11324 layout->section_list().begin();
11325 p != layout->section_list().end();
11326 ++p)
11327 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11328 {
11329 if (exidx_output_section == NULL)
11330 exidx_output_section =
11331 Arm_output_section<big_endian>::as_arm_output_section(*p);
11332 else
11333 // We cannot handle this now.
11334 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11335 "non-relocatable link"),
11336 exidx_output_section->name(),
11337 (*p)->name());
11338 }
11339
11340 if (exidx_output_section != NULL)
11341 {
11342 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11343 symtab, task);
11344 done_exidx_fixup = true;
11345 }
11346 }
11347 else
11348 {
11349 // If this is not the first pass, addresses and file offsets have
11350 // been reset at this point, set them here.
11351 for (Stub_table_iterator sp = this->stub_tables_.begin();
11352 sp != this->stub_tables_.end();
11353 ++sp)
11354 {
11355 Arm_input_section<big_endian>* owner = (*sp)->owner();
11356 off_t off = align_address(owner->original_size(),
11357 (*sp)->addralign());
11358 (*sp)->set_address_and_file_offset(owner->address() + off,
11359 owner->offset() + off);
11360 }
11361 }
11362
11363 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11364 // beginning of each relaxation pass, just blow away all the stubs.
11365 // Alternatively, we could selectively remove only the stubs and reloc
11366 // information for code sections that have moved since the last pass.
11367 // That would require more book-keeping.
11368 if (this->fix_cortex_a8_)
11369 {
11370 // Clear all Cortex-A8 reloc information.
11371 for (typename Cortex_a8_relocs_info::const_iterator p =
11372 this->cortex_a8_relocs_info_.begin();
11373 p != this->cortex_a8_relocs_info_.end();
11374 ++p)
11375 delete p->second;
11376 this->cortex_a8_relocs_info_.clear();
11377
11378 // Remove all Cortex-A8 stubs.
11379 for (Stub_table_iterator sp = this->stub_tables_.begin();
11380 sp != this->stub_tables_.end();
11381 ++sp)
11382 (*sp)->remove_all_cortex_a8_stubs();
11383 }
11384
11385 // Scan relocs for relocation stubs
11386 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11387 op != input_objects->relobj_end();
11388 ++op)
11389 {
11390 Arm_relobj<big_endian>* arm_relobj =
11391 Arm_relobj<big_endian>::as_arm_relobj(*op);
11392 // Lock the object so we can read from it. This is only called
11393 // single-threaded from Layout::finalize, so it is OK to lock.
11394 Task_lock_obj<Object> tl(task, arm_relobj);
11395 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11396 }
11397
11398 // Check all stub tables to see if any of them have their data sizes
11399 // or addresses alignments changed. These are the only things that
11400 // matter.
11401 bool any_stub_table_changed = false;
11402 Unordered_set<const Output_section*> sections_needing_adjustment;
11403 for (Stub_table_iterator sp = this->stub_tables_.begin();
11404 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11405 ++sp)
11406 {
11407 if ((*sp)->update_data_size_and_addralign())
11408 {
11409 // Update data size of stub table owner.
11410 Arm_input_section<big_endian>* owner = (*sp)->owner();
11411 uint64_t address = owner->address();
11412 off_t offset = owner->offset();
11413 owner->reset_address_and_file_offset();
11414 owner->set_address_and_file_offset(address, offset);
11415
11416 sections_needing_adjustment.insert(owner->output_section());
11417 any_stub_table_changed = true;
11418 }
11419 }
11420
11421 // Output_section_data::output_section() returns a const pointer but we
11422 // need to update output sections, so we record all output sections needing
11423 // update above and scan the sections here to find out what sections need
11424 // to be updated.
11425 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11426 p != layout->section_list().end();
11427 ++p)
11428 {
11429 if (sections_needing_adjustment.find(*p)
11430 != sections_needing_adjustment.end())
11431 (*p)->set_section_offsets_need_adjustment();
11432 }
11433
11434 // Stop relaxation if no EXIDX fix-up and no stub table change.
11435 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11436
11437 // Finalize the stubs in the last relaxation pass.
11438 if (!continue_relaxation)
11439 {
11440 for (Stub_table_iterator sp = this->stub_tables_.begin();
11441 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11442 ++sp)
11443 (*sp)->finalize_stubs();
11444
11445 // Update output local symbol counts of objects if necessary.
11446 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11447 op != input_objects->relobj_end();
11448 ++op)
11449 {
11450 Arm_relobj<big_endian>* arm_relobj =
11451 Arm_relobj<big_endian>::as_arm_relobj(*op);
11452
11453 // Update output local symbol counts. We need to discard local
11454 // symbols defined in parts of input sections that are discarded by
11455 // relaxation.
11456 if (arm_relobj->output_local_symbol_count_needs_update())
11457 {
11458 // We need to lock the object's file to update it.
11459 Task_lock_obj<Object> tl(task, arm_relobj);
11460 arm_relobj->update_output_local_symbol_count();
11461 }
11462 }
11463 }
11464
11465 return continue_relaxation;
11466 }
11467
11468 // Relocate a stub.
11469
11470 template<bool big_endian>
11471 void
11472 Target_arm<big_endian>::relocate_stub(
11473 Stub* stub,
11474 const Relocate_info<32, big_endian>* relinfo,
11475 Output_section* output_section,
11476 unsigned char* view,
11477 Arm_address address,
11478 section_size_type view_size)
11479 {
11480 Relocate relocate;
11481 const Stub_template* stub_template = stub->stub_template();
11482 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11483 {
11484 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11485 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11486
11487 unsigned int r_type = insn->r_type();
11488 section_size_type reloc_offset = stub_template->reloc_offset(i);
11489 section_size_type reloc_size = insn->size();
11490 gold_assert(reloc_offset + reloc_size <= view_size);
11491
11492 // This is the address of the stub destination.
11493 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11494 Symbol_value<32> symval;
11495 symval.set_output_value(target);
11496
11497 // Synthesize a fake reloc just in case. We don't have a symbol so
11498 // we use 0.
11499 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11500 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11501 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11502 reloc_write.put_r_offset(reloc_offset);
11503 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11504 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11505
11506 relocate.relocate(relinfo, this, output_section,
11507 this->fake_relnum_for_stubs, rel, r_type,
11508 NULL, &symval, view + reloc_offset,
11509 address + reloc_offset, reloc_size);
11510 }
11511 }
11512
11513 // Determine whether an object attribute tag takes an integer, a
11514 // string or both.
11515
11516 template<bool big_endian>
11517 int
11518 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11519 {
11520 if (tag == Object_attribute::Tag_compatibility)
11521 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11522 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11523 else if (tag == elfcpp::Tag_nodefaults)
11524 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11525 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11526 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11527 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11528 else if (tag < 32)
11529 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11530 else
11531 return ((tag & 1) != 0
11532 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11533 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11534 }
11535
11536 // Reorder attributes.
11537 //
11538 // The ABI defines that Tag_conformance should be emitted first, and that
11539 // Tag_nodefaults should be second (if either is defined). This sets those
11540 // two positions, and bumps up the position of all the remaining tags to
11541 // compensate.
11542
11543 template<bool big_endian>
11544 int
11545 Target_arm<big_endian>::do_attributes_order(int num) const
11546 {
11547 // Reorder the known object attributes in output. We want to move
11548 // Tag_conformance to position 4 and Tag_conformance to position 5
11549 // and shift eveything between 4 .. Tag_conformance - 1 to make room.
11550 if (num == 4)
11551 return elfcpp::Tag_conformance;
11552 if (num == 5)
11553 return elfcpp::Tag_nodefaults;
11554 if ((num - 2) < elfcpp::Tag_nodefaults)
11555 return num - 2;
11556 if ((num - 1) < elfcpp::Tag_conformance)
11557 return num - 1;
11558 return num;
11559 }
11560
11561 // Scan a span of THUMB code for Cortex-A8 erratum.
11562
11563 template<bool big_endian>
11564 void
11565 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11566 Arm_relobj<big_endian>* arm_relobj,
11567 unsigned int shndx,
11568 section_size_type span_start,
11569 section_size_type span_end,
11570 const unsigned char* view,
11571 Arm_address address)
11572 {
11573 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11574 //
11575 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11576 // The branch target is in the same 4KB region as the
11577 // first half of the branch.
11578 // The instruction before the branch is a 32-bit
11579 // length non-branch instruction.
11580 section_size_type i = span_start;
11581 bool last_was_32bit = false;
11582 bool last_was_branch = false;
11583 while (i < span_end)
11584 {
11585 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11586 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11587 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11588 bool is_blx = false, is_b = false;
11589 bool is_bl = false, is_bcc = false;
11590
11591 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11592 if (insn_32bit)
11593 {
11594 // Load the rest of the insn (in manual-friendly order).
11595 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11596
11597 // Encoding T4: B<c>.W.
11598 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11599 // Encoding T1: BL<c>.W.
11600 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11601 // Encoding T2: BLX<c>.W.
11602 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11603 // Encoding T3: B<c>.W (not permitted in IT block).
11604 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11605 && (insn & 0x07f00000U) != 0x03800000U);
11606 }
11607
11608 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11609
11610 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11611 // page boundary and it follows 32-bit non-branch instruction,
11612 // we need to work around.
11613 if (is_32bit_branch
11614 && ((address + i) & 0xfffU) == 0xffeU
11615 && last_was_32bit
11616 && !last_was_branch)
11617 {
11618 // Check to see if there is a relocation stub for this branch.
11619 bool force_target_arm = false;
11620 bool force_target_thumb = false;
11621 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11622 Cortex_a8_relocs_info::const_iterator p =
11623 this->cortex_a8_relocs_info_.find(address + i);
11624
11625 if (p != this->cortex_a8_relocs_info_.end())
11626 {
11627 cortex_a8_reloc = p->second;
11628 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11629
11630 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11631 && !target_is_thumb)
11632 force_target_arm = true;
11633 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11634 && target_is_thumb)
11635 force_target_thumb = true;
11636 }
11637
11638 off_t offset;
11639 Stub_type stub_type = arm_stub_none;
11640
11641 // Check if we have an offending branch instruction.
11642 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11643 uint16_t lower_insn = insn & 0xffffU;
11644 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11645
11646 if (cortex_a8_reloc != NULL
11647 && cortex_a8_reloc->reloc_stub() != NULL)
11648 // We've already made a stub for this instruction, e.g.
11649 // it's a long branch or a Thumb->ARM stub. Assume that
11650 // stub will suffice to work around the A8 erratum (see
11651 // setting of always_after_branch above).
11652 ;
11653 else if (is_bcc)
11654 {
11655 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11656 lower_insn);
11657 stub_type = arm_stub_a8_veneer_b_cond;
11658 }
11659 else if (is_b || is_bl || is_blx)
11660 {
11661 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11662 lower_insn);
11663 if (is_blx)
11664 offset &= ~3;
11665
11666 stub_type = (is_blx
11667 ? arm_stub_a8_veneer_blx
11668 : (is_bl
11669 ? arm_stub_a8_veneer_bl
11670 : arm_stub_a8_veneer_b));
11671 }
11672
11673 if (stub_type != arm_stub_none)
11674 {
11675 Arm_address pc_for_insn = address + i + 4;
11676
11677 // The original instruction is a BL, but the target is
11678 // an ARM instruction. If we were not making a stub,
11679 // the BL would have been converted to a BLX. Use the
11680 // BLX stub instead in that case.
11681 if (this->may_use_blx() && force_target_arm
11682 && stub_type == arm_stub_a8_veneer_bl)
11683 {
11684 stub_type = arm_stub_a8_veneer_blx;
11685 is_blx = true;
11686 is_bl = false;
11687 }
11688 // Conversely, if the original instruction was
11689 // BLX but the target is Thumb mode, use the BL stub.
11690 else if (force_target_thumb
11691 && stub_type == arm_stub_a8_veneer_blx)
11692 {
11693 stub_type = arm_stub_a8_veneer_bl;
11694 is_blx = false;
11695 is_bl = true;
11696 }
11697
11698 if (is_blx)
11699 pc_for_insn &= ~3;
11700
11701 // If we found a relocation, use the proper destination,
11702 // not the offset in the (unrelocated) instruction.
11703 // Note this is always done if we switched the stub type above.
11704 if (cortex_a8_reloc != NULL)
11705 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11706
11707 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11708
11709 // Add a new stub if destination address in in the same page.
11710 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11711 {
11712 Cortex_a8_stub* stub =
11713 this->stub_factory_.make_cortex_a8_stub(stub_type,
11714 arm_relobj, shndx,
11715 address + i,
11716 target, insn);
11717 Stub_table<big_endian>* stub_table =
11718 arm_relobj->stub_table(shndx);
11719 gold_assert(stub_table != NULL);
11720 stub_table->add_cortex_a8_stub(address + i, stub);
11721 }
11722 }
11723 }
11724
11725 i += insn_32bit ? 4 : 2;
11726 last_was_32bit = insn_32bit;
11727 last_was_branch = is_32bit_branch;
11728 }
11729 }
11730
11731 // Apply the Cortex-A8 workaround.
11732
11733 template<bool big_endian>
11734 void
11735 Target_arm<big_endian>::apply_cortex_a8_workaround(
11736 const Cortex_a8_stub* stub,
11737 Arm_address stub_address,
11738 unsigned char* insn_view,
11739 Arm_address insn_address)
11740 {
11741 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11742 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11743 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11744 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11745 off_t branch_offset = stub_address - (insn_address + 4);
11746
11747 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11748 switch (stub->stub_template()->type())
11749 {
11750 case arm_stub_a8_veneer_b_cond:
11751 // For a conditional branch, we re-write it to be a uncondition
11752 // branch to the stub. We use the THUMB-2 encoding here.
11753 upper_insn = 0xf000U;
11754 lower_insn = 0xb800U;
11755 // Fall through
11756 case arm_stub_a8_veneer_b:
11757 case arm_stub_a8_veneer_bl:
11758 case arm_stub_a8_veneer_blx:
11759 if ((lower_insn & 0x5000U) == 0x4000U)
11760 // For a BLX instruction, make sure that the relocation is
11761 // rounded up to a word boundary. This follows the semantics of
11762 // the instruction which specifies that bit 1 of the target
11763 // address will come from bit 1 of the base address.
11764 branch_offset = (branch_offset + 2) & ~3;
11765
11766 // Put BRANCH_OFFSET back into the insn.
11767 gold_assert(!utils::has_overflow<25>(branch_offset));
11768 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11769 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11770 break;
11771
11772 default:
11773 gold_unreachable();
11774 }
11775
11776 // Put the relocated value back in the object file:
11777 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11778 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11779 }
11780
11781 template<bool big_endian>
11782 class Target_selector_arm : public Target_selector
11783 {
11784 public:
11785 Target_selector_arm()
11786 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11787 (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
11788 { }
11789
11790 Target*
11791 do_instantiate_target()
11792 { return new Target_arm<big_endian>(); }
11793 };
11794
11795 // Fix .ARM.exidx section coverage.
11796
11797 template<bool big_endian>
11798 void
11799 Target_arm<big_endian>::fix_exidx_coverage(
11800 Layout* layout,
11801 const Input_objects* input_objects,
11802 Arm_output_section<big_endian>* exidx_section,
11803 Symbol_table* symtab,
11804 const Task* task)
11805 {
11806 // We need to look at all the input sections in output in ascending
11807 // order of of output address. We do that by building a sorted list
11808 // of output sections by addresses. Then we looks at the output sections
11809 // in order. The input sections in an output section are already sorted
11810 // by addresses within the output section.
11811
11812 typedef std::set<Output_section*, output_section_address_less_than>
11813 Sorted_output_section_list;
11814 Sorted_output_section_list sorted_output_sections;
11815
11816 // Find out all the output sections of input sections pointed by
11817 // EXIDX input sections.
11818 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
11819 p != input_objects->relobj_end();
11820 ++p)
11821 {
11822 Arm_relobj<big_endian>* arm_relobj =
11823 Arm_relobj<big_endian>::as_arm_relobj(*p);
11824 std::vector<unsigned int> shndx_list;
11825 arm_relobj->get_exidx_shndx_list(&shndx_list);
11826 for (size_t i = 0; i < shndx_list.size(); ++i)
11827 {
11828 const Arm_exidx_input_section* exidx_input_section =
11829 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
11830 gold_assert(exidx_input_section != NULL);
11831 if (!exidx_input_section->has_errors())
11832 {
11833 unsigned int text_shndx = exidx_input_section->link();
11834 Output_section* os = arm_relobj->output_section(text_shndx);
11835 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
11836 sorted_output_sections.insert(os);
11837 }
11838 }
11839 }
11840
11841 // Go over the output sections in ascending order of output addresses.
11842 typedef typename Arm_output_section<big_endian>::Text_section_list
11843 Text_section_list;
11844 Text_section_list sorted_text_sections;
11845 for (typename Sorted_output_section_list::iterator p =
11846 sorted_output_sections.begin();
11847 p != sorted_output_sections.end();
11848 ++p)
11849 {
11850 Arm_output_section<big_endian>* arm_output_section =
11851 Arm_output_section<big_endian>::as_arm_output_section(*p);
11852 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
11853 }
11854
11855 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
11856 merge_exidx_entries(), task);
11857 }
11858
11859 Target_selector_arm<false> target_selector_arm;
11860 Target_selector_arm<true> target_selector_armbe;
11861
11862 } // End anonymous namespace.
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