2012-02-02 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, 2011, 2012 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 be 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 an invalid index, this points to a global symbol.
602 // Otherwise, it points to a relobj. We used the unsized and target
603 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
604 // Arm_relobj, in order 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 using KEY. The caller is responsible for avoiding addition
899 // if a STUB with the same key has already 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 // The caller is responsible for avoiding addition if a STUB with the same
919 // address has already 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 // responsible 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 // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1346 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1347 elfcpp::Elf_Xword flags)
1348 : Output_section(name, type,
1349 (type == elfcpp::SHT_ARM_EXIDX
1350 ? flags | elfcpp::SHF_LINK_ORDER
1351 : flags))
1352 {
1353 if (type == elfcpp::SHT_ARM_EXIDX)
1354 this->set_always_keeps_input_sections();
1355 }
1356
1357 ~Arm_output_section()
1358 { }
1359
1360 // Group input sections for stub generation.
1361 void
1362 group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1363
1364 // Downcast a base pointer to an Arm_output_section pointer. This is
1365 // not type-safe but we only use Arm_output_section not the base class.
1366 static Arm_output_section<big_endian>*
1367 as_arm_output_section(Output_section* os)
1368 { return static_cast<Arm_output_section<big_endian>*>(os); }
1369
1370 // Append all input text sections in this into LIST.
1371 void
1372 append_text_sections_to_list(Text_section_list* list);
1373
1374 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1375 // is a list of text input sections sorted in ascending order of their
1376 // output addresses.
1377 void
1378 fix_exidx_coverage(Layout* layout,
1379 const Text_section_list& sorted_text_section,
1380 Symbol_table* symtab,
1381 bool merge_exidx_entries,
1382 const Task* task);
1383
1384 // Link an EXIDX section into its corresponding text section.
1385 void
1386 set_exidx_section_link();
1387
1388 private:
1389 // For convenience.
1390 typedef Output_section::Input_section Input_section;
1391 typedef Output_section::Input_section_list Input_section_list;
1392
1393 // Create a stub group.
1394 void create_stub_group(Input_section_list::const_iterator,
1395 Input_section_list::const_iterator,
1396 Input_section_list::const_iterator,
1397 Target_arm<big_endian>*,
1398 std::vector<Output_relaxed_input_section*>*,
1399 const Task* task);
1400 };
1401
1402 // Arm_exidx_input_section class. This represents an EXIDX input section.
1403
1404 class Arm_exidx_input_section
1405 {
1406 public:
1407 static const section_offset_type invalid_offset =
1408 static_cast<section_offset_type>(-1);
1409
1410 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1411 unsigned int link, uint32_t size,
1412 uint32_t addralign, uint32_t text_size)
1413 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1414 addralign_(addralign), text_size_(text_size), has_errors_(false)
1415 { }
1416
1417 ~Arm_exidx_input_section()
1418 { }
1419
1420 // Accessors: This is a read-only class.
1421
1422 // Return the object containing this EXIDX input section.
1423 Relobj*
1424 relobj() const
1425 { return this->relobj_; }
1426
1427 // Return the section index of this EXIDX input section.
1428 unsigned int
1429 shndx() const
1430 { return this->shndx_; }
1431
1432 // Return the section index of linked text section in the same object.
1433 unsigned int
1434 link() const
1435 { return this->link_; }
1436
1437 // Return size of the EXIDX input section.
1438 uint32_t
1439 size() const
1440 { return this->size_; }
1441
1442 // Return address alignment of EXIDX input section.
1443 uint32_t
1444 addralign() const
1445 { return this->addralign_; }
1446
1447 // Return size of the associated text input section.
1448 uint32_t
1449 text_size() const
1450 { return this->text_size_; }
1451
1452 // Whether there are any errors in the EXIDX input section.
1453 bool
1454 has_errors() const
1455 { return this->has_errors_; }
1456
1457 // Set has-errors flag.
1458 void
1459 set_has_errors()
1460 { this->has_errors_ = true; }
1461
1462 private:
1463 // Object containing this.
1464 Relobj* relobj_;
1465 // Section index of this.
1466 unsigned int shndx_;
1467 // text section linked to this in the same object.
1468 unsigned int link_;
1469 // Size of this. For ARM 32-bit is sufficient.
1470 uint32_t size_;
1471 // Address alignment of this. For ARM 32-bit is sufficient.
1472 uint32_t addralign_;
1473 // Size of associated text section.
1474 uint32_t text_size_;
1475 // Whether this has any errors.
1476 bool has_errors_;
1477 };
1478
1479 // Arm_relobj class.
1480
1481 template<bool big_endian>
1482 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1483 {
1484 public:
1485 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1486
1487 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1488 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1489 : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1490 stub_tables_(), local_symbol_is_thumb_function_(),
1491 attributes_section_data_(NULL), mapping_symbols_info_(),
1492 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1493 output_local_symbol_count_needs_update_(false),
1494 merge_flags_and_attributes_(true)
1495 { }
1496
1497 ~Arm_relobj()
1498 { delete this->attributes_section_data_; }
1499
1500 // Return the stub table of the SHNDX-th section if there is one.
1501 Stub_table<big_endian>*
1502 stub_table(unsigned int shndx) const
1503 {
1504 gold_assert(shndx < this->stub_tables_.size());
1505 return this->stub_tables_[shndx];
1506 }
1507
1508 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1509 void
1510 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1511 {
1512 gold_assert(shndx < this->stub_tables_.size());
1513 this->stub_tables_[shndx] = stub_table;
1514 }
1515
1516 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1517 // index. This is only valid after do_count_local_symbol is called.
1518 bool
1519 local_symbol_is_thumb_function(unsigned int r_sym) const
1520 {
1521 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1522 return this->local_symbol_is_thumb_function_[r_sym];
1523 }
1524
1525 // Scan all relocation sections for stub generation.
1526 void
1527 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1528 const Layout*);
1529
1530 // Convert regular input section with index SHNDX to a relaxed section.
1531 void
1532 convert_input_section_to_relaxed_section(unsigned shndx)
1533 {
1534 // The stubs have relocations and we need to process them after writing
1535 // out the stubs. So relocation now must follow section write.
1536 this->set_section_offset(shndx, -1ULL);
1537 this->set_relocs_must_follow_section_writes();
1538 }
1539
1540 // Downcast a base pointer to an Arm_relobj pointer. This is
1541 // not type-safe but we only use Arm_relobj not the base class.
1542 static Arm_relobj<big_endian>*
1543 as_arm_relobj(Relobj* relobj)
1544 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1545
1546 // Processor-specific flags in ELF file header. This is valid only after
1547 // reading symbols.
1548 elfcpp::Elf_Word
1549 processor_specific_flags() const
1550 { return this->processor_specific_flags_; }
1551
1552 // Attribute section data This is the contents of the .ARM.attribute section
1553 // if there is one.
1554 const Attributes_section_data*
1555 attributes_section_data() const
1556 { return this->attributes_section_data_; }
1557
1558 // Mapping symbol location.
1559 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1560
1561 // Functor for STL container.
1562 struct Mapping_symbol_position_less
1563 {
1564 bool
1565 operator()(const Mapping_symbol_position& p1,
1566 const Mapping_symbol_position& p2) const
1567 {
1568 return (p1.first < p2.first
1569 || (p1.first == p2.first && p1.second < p2.second));
1570 }
1571 };
1572
1573 // We only care about the first character of a mapping symbol, so
1574 // we only store that instead of the whole symbol name.
1575 typedef std::map<Mapping_symbol_position, char,
1576 Mapping_symbol_position_less> Mapping_symbols_info;
1577
1578 // Whether a section contains any Cortex-A8 workaround.
1579 bool
1580 section_has_cortex_a8_workaround(unsigned int shndx) const
1581 {
1582 return (this->section_has_cortex_a8_workaround_ != NULL
1583 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1584 }
1585
1586 // Mark a section that has Cortex-A8 workaround.
1587 void
1588 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1589 {
1590 if (this->section_has_cortex_a8_workaround_ == NULL)
1591 this->section_has_cortex_a8_workaround_ =
1592 new std::vector<bool>(this->shnum(), false);
1593 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1594 }
1595
1596 // Return the EXIDX section of an text section with index SHNDX or NULL
1597 // if the text section has no associated EXIDX section.
1598 const Arm_exidx_input_section*
1599 exidx_input_section_by_link(unsigned int shndx) const
1600 {
1601 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1602 return ((p != this->exidx_section_map_.end()
1603 && p->second->link() == shndx)
1604 ? p->second
1605 : NULL);
1606 }
1607
1608 // Return the EXIDX section with index SHNDX or NULL if there is none.
1609 const Arm_exidx_input_section*
1610 exidx_input_section_by_shndx(unsigned shndx) const
1611 {
1612 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1613 return ((p != this->exidx_section_map_.end()
1614 && p->second->shndx() == shndx)
1615 ? p->second
1616 : NULL);
1617 }
1618
1619 // Whether output local symbol count needs updating.
1620 bool
1621 output_local_symbol_count_needs_update() const
1622 { return this->output_local_symbol_count_needs_update_; }
1623
1624 // Set output_local_symbol_count_needs_update flag to be true.
1625 void
1626 set_output_local_symbol_count_needs_update()
1627 { this->output_local_symbol_count_needs_update_ = true; }
1628
1629 // Update output local symbol count at the end of relaxation.
1630 void
1631 update_output_local_symbol_count();
1632
1633 // Whether we want to merge processor-specific flags and attributes.
1634 bool
1635 merge_flags_and_attributes() const
1636 { return this->merge_flags_and_attributes_; }
1637
1638 // Export list of EXIDX section indices.
1639 void
1640 get_exidx_shndx_list(std::vector<unsigned int>* list) const
1641 {
1642 list->clear();
1643 for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1644 p != this->exidx_section_map_.end();
1645 ++p)
1646 {
1647 if (p->second->shndx() == p->first)
1648 list->push_back(p->first);
1649 }
1650 // Sort list to make result independent of implementation of map.
1651 std::sort(list->begin(), list->end());
1652 }
1653
1654 protected:
1655 // Post constructor setup.
1656 void
1657 do_setup()
1658 {
1659 // Call parent's setup method.
1660 Sized_relobj_file<32, big_endian>::do_setup();
1661
1662 // Initialize look-up tables.
1663 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1664 this->stub_tables_.swap(empty_stub_table_list);
1665 }
1666
1667 // Count the local symbols.
1668 void
1669 do_count_local_symbols(Stringpool_template<char>*,
1670 Stringpool_template<char>*);
1671
1672 void
1673 do_relocate_sections(
1674 const Symbol_table* symtab, const Layout* layout,
1675 const unsigned char* pshdrs, Output_file* of,
1676 typename Sized_relobj_file<32, big_endian>::Views* pivews);
1677
1678 // Read the symbol information.
1679 void
1680 do_read_symbols(Read_symbols_data* sd);
1681
1682 // Process relocs for garbage collection.
1683 void
1684 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1685
1686 private:
1687
1688 // Whether a section needs to be scanned for relocation stubs.
1689 bool
1690 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1691 const Relobj::Output_sections&,
1692 const Symbol_table*, const unsigned char*);
1693
1694 // Whether a section is a scannable text section.
1695 bool
1696 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1697 const Output_section*, const Symbol_table*);
1698
1699 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1700 bool
1701 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1702 unsigned int, Output_section*,
1703 const Symbol_table*);
1704
1705 // Scan a section for the Cortex-A8 erratum.
1706 void
1707 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1708 unsigned int, Output_section*,
1709 Target_arm<big_endian>*);
1710
1711 // Find the linked text section of an EXIDX section by looking at the
1712 // first relocation of the EXIDX section. PSHDR points to the section
1713 // headers of a relocation section and PSYMS points to the local symbols.
1714 // PSHNDX points to a location storing the text section index if found.
1715 // Return whether we can find the linked section.
1716 bool
1717 find_linked_text_section(const unsigned char* pshdr,
1718 const unsigned char* psyms, unsigned int* pshndx);
1719
1720 //
1721 // Make a new Arm_exidx_input_section object for EXIDX section with
1722 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1723 // index of the linked text section.
1724 void
1725 make_exidx_input_section(unsigned int shndx,
1726 const elfcpp::Shdr<32, big_endian>& shdr,
1727 unsigned int text_shndx,
1728 const elfcpp::Shdr<32, big_endian>& text_shdr);
1729
1730 // Return the output address of either a plain input section or a
1731 // relaxed input section. SHNDX is the section index.
1732 Arm_address
1733 simple_input_section_output_address(unsigned int, Output_section*);
1734
1735 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1736 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1737 Exidx_section_map;
1738
1739 // List of stub tables.
1740 Stub_table_list stub_tables_;
1741 // Bit vector to tell if a local symbol is a thumb function or not.
1742 // This is only valid after do_count_local_symbol is called.
1743 std::vector<bool> local_symbol_is_thumb_function_;
1744 // processor-specific flags in ELF file header.
1745 elfcpp::Elf_Word processor_specific_flags_;
1746 // Object attributes if there is an .ARM.attributes section or NULL.
1747 Attributes_section_data* attributes_section_data_;
1748 // Mapping symbols information.
1749 Mapping_symbols_info mapping_symbols_info_;
1750 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1751 std::vector<bool>* section_has_cortex_a8_workaround_;
1752 // Map a text section to its associated .ARM.exidx section, if there is one.
1753 Exidx_section_map exidx_section_map_;
1754 // Whether output local symbol count needs updating.
1755 bool output_local_symbol_count_needs_update_;
1756 // Whether we merge processor flags and attributes of this object to
1757 // output.
1758 bool merge_flags_and_attributes_;
1759 };
1760
1761 // Arm_dynobj class.
1762
1763 template<bool big_endian>
1764 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1765 {
1766 public:
1767 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1768 const elfcpp::Ehdr<32, big_endian>& ehdr)
1769 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1770 processor_specific_flags_(0), attributes_section_data_(NULL)
1771 { }
1772
1773 ~Arm_dynobj()
1774 { delete this->attributes_section_data_; }
1775
1776 // Downcast a base pointer to an Arm_relobj pointer. This is
1777 // not type-safe but we only use Arm_relobj not the base class.
1778 static Arm_dynobj<big_endian>*
1779 as_arm_dynobj(Dynobj* dynobj)
1780 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1781
1782 // Processor-specific flags in ELF file header. This is valid only after
1783 // reading symbols.
1784 elfcpp::Elf_Word
1785 processor_specific_flags() const
1786 { return this->processor_specific_flags_; }
1787
1788 // Attributes section data.
1789 const Attributes_section_data*
1790 attributes_section_data() const
1791 { return this->attributes_section_data_; }
1792
1793 protected:
1794 // Read the symbol information.
1795 void
1796 do_read_symbols(Read_symbols_data* sd);
1797
1798 private:
1799 // processor-specific flags in ELF file header.
1800 elfcpp::Elf_Word processor_specific_flags_;
1801 // Object attributes if there is an .ARM.attributes section or NULL.
1802 Attributes_section_data* attributes_section_data_;
1803 };
1804
1805 // Functor to read reloc addends during stub generation.
1806
1807 template<int sh_type, bool big_endian>
1808 struct Stub_addend_reader
1809 {
1810 // Return the addend for a relocation of a particular type. Depending
1811 // on whether this is a REL or RELA relocation, read the addend from a
1812 // view or from a Reloc object.
1813 elfcpp::Elf_types<32>::Elf_Swxword
1814 operator()(
1815 unsigned int /* r_type */,
1816 const unsigned char* /* view */,
1817 const typename Reloc_types<sh_type,
1818 32, big_endian>::Reloc& /* reloc */) const;
1819 };
1820
1821 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1822
1823 template<bool big_endian>
1824 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1825 {
1826 elfcpp::Elf_types<32>::Elf_Swxword
1827 operator()(
1828 unsigned int,
1829 const unsigned char*,
1830 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1831 };
1832
1833 // Specialized Stub_addend_reader for RELA type relocation sections.
1834 // We currently do not handle RELA type relocation sections but it is trivial
1835 // to implement the addend reader. This is provided for completeness and to
1836 // make it easier to add support for RELA relocation sections in the future.
1837
1838 template<bool big_endian>
1839 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1840 {
1841 elfcpp::Elf_types<32>::Elf_Swxword
1842 operator()(
1843 unsigned int,
1844 const unsigned char*,
1845 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1846 big_endian>::Reloc& reloc) const
1847 { return reloc.get_r_addend(); }
1848 };
1849
1850 // Cortex_a8_reloc class. We keep record of relocation that may need
1851 // the Cortex-A8 erratum workaround.
1852
1853 class Cortex_a8_reloc
1854 {
1855 public:
1856 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1857 Arm_address destination)
1858 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1859 { }
1860
1861 ~Cortex_a8_reloc()
1862 { }
1863
1864 // Accessors: This is a read-only class.
1865
1866 // Return the relocation stub associated with this relocation if there is
1867 // one.
1868 const Reloc_stub*
1869 reloc_stub() const
1870 { return this->reloc_stub_; }
1871
1872 // Return the relocation type.
1873 unsigned int
1874 r_type() const
1875 { return this->r_type_; }
1876
1877 // Return the destination address of the relocation. LSB stores the THUMB
1878 // bit.
1879 Arm_address
1880 destination() const
1881 { return this->destination_; }
1882
1883 private:
1884 // Associated relocation stub if there is one, or NULL.
1885 const Reloc_stub* reloc_stub_;
1886 // Relocation type.
1887 unsigned int r_type_;
1888 // Destination address of this relocation. LSB is used to distinguish
1889 // ARM/THUMB mode.
1890 Arm_address destination_;
1891 };
1892
1893 // Arm_output_data_got class. We derive this from Output_data_got to add
1894 // extra methods to handle TLS relocations in a static link.
1895
1896 template<bool big_endian>
1897 class Arm_output_data_got : public Output_data_got<32, big_endian>
1898 {
1899 public:
1900 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1901 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1902 { }
1903
1904 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1905 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1906 // applied in a static link.
1907 void
1908 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1909 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1910
1911 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1912 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1913 // relocation that needs to be applied in a static link.
1914 void
1915 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1916 Sized_relobj_file<32, big_endian>* relobj,
1917 unsigned int index)
1918 {
1919 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1920 index));
1921 }
1922
1923 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1924 // The first one is initialized to be 1, which is the module index for
1925 // the main executable and the second one 0. A reloc of the type
1926 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1927 // be applied by gold. GSYM is a global symbol.
1928 void
1929 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1930
1931 // Same as the above but for a local symbol in OBJECT with INDEX.
1932 void
1933 add_tls_gd32_with_static_reloc(unsigned int got_type,
1934 Sized_relobj_file<32, big_endian>* object,
1935 unsigned int index);
1936
1937 protected:
1938 // Write out the GOT table.
1939 void
1940 do_write(Output_file*);
1941
1942 private:
1943 // This class represent dynamic relocations that need to be applied by
1944 // gold because we are using TLS relocations in a static link.
1945 class Static_reloc
1946 {
1947 public:
1948 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1949 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1950 { this->u_.global.symbol = gsym; }
1951
1952 Static_reloc(unsigned int got_offset, unsigned int r_type,
1953 Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1954 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1955 {
1956 this->u_.local.relobj = relobj;
1957 this->u_.local.index = index;
1958 }
1959
1960 // Return the GOT offset.
1961 unsigned int
1962 got_offset() const
1963 { return this->got_offset_; }
1964
1965 // Relocation type.
1966 unsigned int
1967 r_type() const
1968 { return this->r_type_; }
1969
1970 // Whether the symbol is global or not.
1971 bool
1972 symbol_is_global() const
1973 { return this->symbol_is_global_; }
1974
1975 // For a relocation against a global symbol, the global symbol.
1976 Symbol*
1977 symbol() const
1978 {
1979 gold_assert(this->symbol_is_global_);
1980 return this->u_.global.symbol;
1981 }
1982
1983 // For a relocation against a local symbol, the defining object.
1984 Sized_relobj_file<32, big_endian>*
1985 relobj() const
1986 {
1987 gold_assert(!this->symbol_is_global_);
1988 return this->u_.local.relobj;
1989 }
1990
1991 // For a relocation against a local symbol, the local symbol index.
1992 unsigned int
1993 index() const
1994 {
1995 gold_assert(!this->symbol_is_global_);
1996 return this->u_.local.index;
1997 }
1998
1999 private:
2000 // GOT offset of the entry to which this relocation is applied.
2001 unsigned int got_offset_;
2002 // Type of relocation.
2003 unsigned int r_type_;
2004 // Whether this relocation is against a global symbol.
2005 bool symbol_is_global_;
2006 // A global or local symbol.
2007 union
2008 {
2009 struct
2010 {
2011 // For a global symbol, the symbol itself.
2012 Symbol* symbol;
2013 } global;
2014 struct
2015 {
2016 // For a local symbol, the object defining object.
2017 Sized_relobj_file<32, big_endian>* relobj;
2018 // For a local symbol, the symbol index.
2019 unsigned int index;
2020 } local;
2021 } u_;
2022 };
2023
2024 // Symbol table of the output object.
2025 Symbol_table* symbol_table_;
2026 // Layout of the output object.
2027 Layout* layout_;
2028 // Static relocs to be applied to the GOT.
2029 std::vector<Static_reloc> static_relocs_;
2030 };
2031
2032 // The ARM target has many relocation types with odd-sizes or noncontiguous
2033 // bits. The default handling of relocatable relocation cannot process these
2034 // relocations. So we have to extend the default code.
2035
2036 template<bool big_endian, int sh_type, typename Classify_reloc>
2037 class Arm_scan_relocatable_relocs :
2038 public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2039 {
2040 public:
2041 // Return the strategy to use for a local symbol which is a section
2042 // symbol, given the relocation type.
2043 inline Relocatable_relocs::Reloc_strategy
2044 local_section_strategy(unsigned int r_type, Relobj*)
2045 {
2046 if (sh_type == elfcpp::SHT_RELA)
2047 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2048 else
2049 {
2050 if (r_type == elfcpp::R_ARM_TARGET1
2051 || r_type == elfcpp::R_ARM_TARGET2)
2052 {
2053 const Target_arm<big_endian>* arm_target =
2054 Target_arm<big_endian>::default_target();
2055 r_type = arm_target->get_real_reloc_type(r_type);
2056 }
2057
2058 switch(r_type)
2059 {
2060 // Relocations that write nothing. These exclude R_ARM_TARGET1
2061 // and R_ARM_TARGET2.
2062 case elfcpp::R_ARM_NONE:
2063 case elfcpp::R_ARM_V4BX:
2064 case elfcpp::R_ARM_TLS_GOTDESC:
2065 case elfcpp::R_ARM_TLS_CALL:
2066 case elfcpp::R_ARM_TLS_DESCSEQ:
2067 case elfcpp::R_ARM_THM_TLS_CALL:
2068 case elfcpp::R_ARM_GOTRELAX:
2069 case elfcpp::R_ARM_GNU_VTENTRY:
2070 case elfcpp::R_ARM_GNU_VTINHERIT:
2071 case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2072 case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2073 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2074 // These should have been converted to something else above.
2075 case elfcpp::R_ARM_TARGET1:
2076 case elfcpp::R_ARM_TARGET2:
2077 gold_unreachable();
2078 // Relocations that write full 32 bits and
2079 // have alignment of 1.
2080 case elfcpp::R_ARM_ABS32:
2081 case elfcpp::R_ARM_REL32:
2082 case elfcpp::R_ARM_SBREL32:
2083 case elfcpp::R_ARM_GOTOFF32:
2084 case elfcpp::R_ARM_BASE_PREL:
2085 case elfcpp::R_ARM_GOT_BREL:
2086 case elfcpp::R_ARM_BASE_ABS:
2087 case elfcpp::R_ARM_ABS32_NOI:
2088 case elfcpp::R_ARM_REL32_NOI:
2089 case elfcpp::R_ARM_PLT32_ABS:
2090 case elfcpp::R_ARM_GOT_ABS:
2091 case elfcpp::R_ARM_GOT_PREL:
2092 case elfcpp::R_ARM_TLS_GD32:
2093 case elfcpp::R_ARM_TLS_LDM32:
2094 case elfcpp::R_ARM_TLS_LDO32:
2095 case elfcpp::R_ARM_TLS_IE32:
2096 case elfcpp::R_ARM_TLS_LE32:
2097 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2098 default:
2099 // For all other static relocations, return RELOC_SPECIAL.
2100 return Relocatable_relocs::RELOC_SPECIAL;
2101 }
2102 }
2103 }
2104 };
2105
2106 template<bool big_endian>
2107 class Target_arm : public Sized_target<32, big_endian>
2108 {
2109 public:
2110 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2111 Reloc_section;
2112
2113 // When were are relocating a stub, we pass this as the relocation number.
2114 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2115
2116 Target_arm()
2117 : Sized_target<32, big_endian>(&arm_info),
2118 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2119 copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
2120 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2121 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2122 should_force_pic_veneer_(false),
2123 arm_input_section_map_(), attributes_section_data_(NULL),
2124 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2125 { }
2126
2127 // Whether we force PCI branch veneers.
2128 bool
2129 should_force_pic_veneer() const
2130 { return this->should_force_pic_veneer_; }
2131
2132 // Set PIC veneer flag.
2133 void
2134 set_should_force_pic_veneer(bool value)
2135 { this->should_force_pic_veneer_ = value; }
2136
2137 // Whether we use THUMB-2 instructions.
2138 bool
2139 using_thumb2() const
2140 {
2141 Object_attribute* attr =
2142 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2143 int arch = attr->int_value();
2144 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2145 }
2146
2147 // Whether we use THUMB/THUMB-2 instructions only.
2148 bool
2149 using_thumb_only() const
2150 {
2151 Object_attribute* attr =
2152 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2153
2154 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2155 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2156 return true;
2157 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2158 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2159 return false;
2160 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2161 return attr->int_value() == 'M';
2162 }
2163
2164 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2165 bool
2166 may_use_arm_nop() const
2167 {
2168 Object_attribute* attr =
2169 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2170 int arch = attr->int_value();
2171 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2172 || arch == elfcpp::TAG_CPU_ARCH_V6K
2173 || arch == elfcpp::TAG_CPU_ARCH_V7
2174 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2175 }
2176
2177 // Whether we have THUMB-2 NOP.W instruction.
2178 bool
2179 may_use_thumb2_nop() const
2180 {
2181 Object_attribute* attr =
2182 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2183 int arch = attr->int_value();
2184 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2185 || arch == elfcpp::TAG_CPU_ARCH_V7
2186 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2187 }
2188
2189 // Whether we have v4T interworking instructions available.
2190 bool
2191 may_use_v4t_interworking() const
2192 {
2193 Object_attribute* attr =
2194 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2195 int arch = attr->int_value();
2196 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2197 && arch != elfcpp::TAG_CPU_ARCH_V4);
2198 }
2199
2200 // Whether we have v5T interworking instructions available.
2201 bool
2202 may_use_v5t_interworking() const
2203 {
2204 Object_attribute* attr =
2205 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2206 int arch = attr->int_value();
2207 if (parameters->options().fix_arm1176())
2208 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2209 || arch == elfcpp::TAG_CPU_ARCH_V7
2210 || arch == elfcpp::TAG_CPU_ARCH_V6_M
2211 || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2212 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2213 else
2214 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2215 && arch != elfcpp::TAG_CPU_ARCH_V4
2216 && arch != elfcpp::TAG_CPU_ARCH_V4T);
2217 }
2218
2219 // Process the relocations to determine unreferenced sections for
2220 // garbage collection.
2221 void
2222 gc_process_relocs(Symbol_table* symtab,
2223 Layout* layout,
2224 Sized_relobj_file<32, big_endian>* object,
2225 unsigned int data_shndx,
2226 unsigned int sh_type,
2227 const unsigned char* prelocs,
2228 size_t reloc_count,
2229 Output_section* output_section,
2230 bool needs_special_offset_handling,
2231 size_t local_symbol_count,
2232 const unsigned char* plocal_symbols);
2233
2234 // Scan the relocations to look for symbol adjustments.
2235 void
2236 scan_relocs(Symbol_table* symtab,
2237 Layout* layout,
2238 Sized_relobj_file<32, big_endian>* object,
2239 unsigned int data_shndx,
2240 unsigned int sh_type,
2241 const unsigned char* prelocs,
2242 size_t reloc_count,
2243 Output_section* output_section,
2244 bool needs_special_offset_handling,
2245 size_t local_symbol_count,
2246 const unsigned char* plocal_symbols);
2247
2248 // Finalize the sections.
2249 void
2250 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2251
2252 // Return the value to use for a dynamic symbol which requires special
2253 // treatment.
2254 uint64_t
2255 do_dynsym_value(const Symbol*) const;
2256
2257 // Relocate a section.
2258 void
2259 relocate_section(const Relocate_info<32, big_endian>*,
2260 unsigned int sh_type,
2261 const unsigned char* prelocs,
2262 size_t reloc_count,
2263 Output_section* output_section,
2264 bool needs_special_offset_handling,
2265 unsigned char* view,
2266 Arm_address view_address,
2267 section_size_type view_size,
2268 const Reloc_symbol_changes*);
2269
2270 // Scan the relocs during a relocatable link.
2271 void
2272 scan_relocatable_relocs(Symbol_table* symtab,
2273 Layout* layout,
2274 Sized_relobj_file<32, big_endian>* object,
2275 unsigned int data_shndx,
2276 unsigned int sh_type,
2277 const unsigned char* prelocs,
2278 size_t reloc_count,
2279 Output_section* output_section,
2280 bool needs_special_offset_handling,
2281 size_t local_symbol_count,
2282 const unsigned char* plocal_symbols,
2283 Relocatable_relocs*);
2284
2285 // Relocate a section during a relocatable link.
2286 void
2287 relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2288 unsigned int sh_type,
2289 const unsigned char* prelocs,
2290 size_t reloc_count,
2291 Output_section* output_section,
2292 off_t offset_in_output_section,
2293 const Relocatable_relocs*,
2294 unsigned char* view,
2295 Arm_address view_address,
2296 section_size_type view_size,
2297 unsigned char* reloc_view,
2298 section_size_type reloc_view_size);
2299
2300 // Perform target-specific processing in a relocatable link. This is
2301 // only used if we use the relocation strategy RELOC_SPECIAL.
2302 void
2303 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2304 unsigned int sh_type,
2305 const unsigned char* preloc_in,
2306 size_t relnum,
2307 Output_section* output_section,
2308 off_t offset_in_output_section,
2309 unsigned char* view,
2310 typename elfcpp::Elf_types<32>::Elf_Addr
2311 view_address,
2312 section_size_type view_size,
2313 unsigned char* preloc_out);
2314
2315 // Return whether SYM is defined by the ABI.
2316 bool
2317 do_is_defined_by_abi(Symbol* sym) const
2318 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2319
2320 // Return whether there is a GOT section.
2321 bool
2322 has_got_section() const
2323 { return this->got_ != NULL; }
2324
2325 // Return the size of the GOT section.
2326 section_size_type
2327 got_size() const
2328 {
2329 gold_assert(this->got_ != NULL);
2330 return this->got_->data_size();
2331 }
2332
2333 // Return the number of entries in the GOT.
2334 unsigned int
2335 got_entry_count() const
2336 {
2337 if (!this->has_got_section())
2338 return 0;
2339 return this->got_size() / 4;
2340 }
2341
2342 // Return the number of entries in the PLT.
2343 unsigned int
2344 plt_entry_count() const;
2345
2346 // Return the offset of the first non-reserved PLT entry.
2347 unsigned int
2348 first_plt_entry_offset() const;
2349
2350 // Return the size of each PLT entry.
2351 unsigned int
2352 plt_entry_size() const;
2353
2354 // Map platform-specific reloc types
2355 static unsigned int
2356 get_real_reloc_type(unsigned int r_type);
2357
2358 //
2359 // Methods to support stub-generations.
2360 //
2361
2362 // Return the stub factory
2363 const Stub_factory&
2364 stub_factory() const
2365 { return this->stub_factory_; }
2366
2367 // Make a new Arm_input_section object.
2368 Arm_input_section<big_endian>*
2369 new_arm_input_section(Relobj*, unsigned int);
2370
2371 // Find the Arm_input_section object corresponding to the SHNDX-th input
2372 // section of RELOBJ.
2373 Arm_input_section<big_endian>*
2374 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2375
2376 // Make a new Stub_table
2377 Stub_table<big_endian>*
2378 new_stub_table(Arm_input_section<big_endian>*);
2379
2380 // Scan a section for stub generation.
2381 void
2382 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2383 const unsigned char*, size_t, Output_section*,
2384 bool, const unsigned char*, Arm_address,
2385 section_size_type);
2386
2387 // Relocate a stub.
2388 void
2389 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2390 Output_section*, unsigned char*, Arm_address,
2391 section_size_type);
2392
2393 // Get the default ARM target.
2394 static Target_arm<big_endian>*
2395 default_target()
2396 {
2397 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2398 && parameters->target().is_big_endian() == big_endian);
2399 return static_cast<Target_arm<big_endian>*>(
2400 parameters->sized_target<32, big_endian>());
2401 }
2402
2403 // Whether NAME belongs to a mapping symbol.
2404 static bool
2405 is_mapping_symbol_name(const char* name)
2406 {
2407 return (name
2408 && name[0] == '$'
2409 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2410 && (name[2] == '\0' || name[2] == '.'));
2411 }
2412
2413 // Whether we work around the Cortex-A8 erratum.
2414 bool
2415 fix_cortex_a8() const
2416 { return this->fix_cortex_a8_; }
2417
2418 // Whether we merge exidx entries in debuginfo.
2419 bool
2420 merge_exidx_entries() const
2421 { return parameters->options().merge_exidx_entries(); }
2422
2423 // Whether we fix R_ARM_V4BX relocation.
2424 // 0 - do not fix
2425 // 1 - replace with MOV instruction (armv4 target)
2426 // 2 - make interworking veneer (>= armv4t targets only)
2427 General_options::Fix_v4bx
2428 fix_v4bx() const
2429 { return parameters->options().fix_v4bx(); }
2430
2431 // Scan a span of THUMB code section for Cortex-A8 erratum.
2432 void
2433 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2434 section_size_type, section_size_type,
2435 const unsigned char*, Arm_address);
2436
2437 // Apply Cortex-A8 workaround to a branch.
2438 void
2439 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2440 unsigned char*, Arm_address);
2441
2442 protected:
2443 // Make an ELF object.
2444 Object*
2445 do_make_elf_object(const std::string&, Input_file*, off_t,
2446 const elfcpp::Ehdr<32, big_endian>& ehdr);
2447
2448 Object*
2449 do_make_elf_object(const std::string&, Input_file*, off_t,
2450 const elfcpp::Ehdr<32, !big_endian>&)
2451 { gold_unreachable(); }
2452
2453 Object*
2454 do_make_elf_object(const std::string&, Input_file*, off_t,
2455 const elfcpp::Ehdr<64, false>&)
2456 { gold_unreachable(); }
2457
2458 Object*
2459 do_make_elf_object(const std::string&, Input_file*, off_t,
2460 const elfcpp::Ehdr<64, true>&)
2461 { gold_unreachable(); }
2462
2463 // Make an output section.
2464 Output_section*
2465 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2466 elfcpp::Elf_Xword flags)
2467 { return new Arm_output_section<big_endian>(name, type, flags); }
2468
2469 void
2470 do_adjust_elf_header(unsigned char* view, int len) const;
2471
2472 // We only need to generate stubs, and hence perform relaxation if we are
2473 // not doing relocatable linking.
2474 bool
2475 do_may_relax() const
2476 { return !parameters->options().relocatable(); }
2477
2478 bool
2479 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2480
2481 // Determine whether an object attribute tag takes an integer, a
2482 // string or both.
2483 int
2484 do_attribute_arg_type(int tag) const;
2485
2486 // Reorder tags during output.
2487 int
2488 do_attributes_order(int num) const;
2489
2490 // This is called when the target is selected as the default.
2491 void
2492 do_select_as_default_target()
2493 {
2494 // No locking is required since there should only be one default target.
2495 // We cannot have both the big-endian and little-endian ARM targets
2496 // as the default.
2497 gold_assert(arm_reloc_property_table == NULL);
2498 arm_reloc_property_table = new Arm_reloc_property_table();
2499 }
2500
2501 // Virtual function which is set to return true by a target if
2502 // it can use relocation types to determine if a function's
2503 // pointer is taken.
2504 virtual bool
2505 do_can_check_for_function_pointers() const
2506 { return true; }
2507
2508 // Whether a section called SECTION_NAME may have function pointers to
2509 // sections not eligible for safe ICF folding.
2510 virtual bool
2511 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2512 {
2513 return (!is_prefix_of(".ARM.exidx", section_name)
2514 && !is_prefix_of(".ARM.extab", section_name)
2515 && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2516 }
2517
2518 private:
2519 // The class which scans relocations.
2520 class Scan
2521 {
2522 public:
2523 Scan()
2524 : issued_non_pic_error_(false)
2525 { }
2526
2527 static inline int
2528 get_reference_flags(unsigned int r_type);
2529
2530 inline void
2531 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2532 Sized_relobj_file<32, big_endian>* object,
2533 unsigned int data_shndx,
2534 Output_section* output_section,
2535 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2536 const elfcpp::Sym<32, big_endian>& lsym);
2537
2538 inline void
2539 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2540 Sized_relobj_file<32, big_endian>* object,
2541 unsigned int data_shndx,
2542 Output_section* output_section,
2543 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2544 Symbol* gsym);
2545
2546 inline bool
2547 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2548 Sized_relobj_file<32, big_endian>* ,
2549 unsigned int ,
2550 Output_section* ,
2551 const elfcpp::Rel<32, big_endian>& ,
2552 unsigned int ,
2553 const elfcpp::Sym<32, big_endian>&);
2554
2555 inline bool
2556 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2557 Sized_relobj_file<32, big_endian>* ,
2558 unsigned int ,
2559 Output_section* ,
2560 const elfcpp::Rel<32, big_endian>& ,
2561 unsigned int , Symbol*);
2562
2563 private:
2564 static void
2565 unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2566 unsigned int r_type);
2567
2568 static void
2569 unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2570 unsigned int r_type, Symbol*);
2571
2572 void
2573 check_non_pic(Relobj*, unsigned int r_type);
2574
2575 // Almost identical to Symbol::needs_plt_entry except that it also
2576 // handles STT_ARM_TFUNC.
2577 static bool
2578 symbol_needs_plt_entry(const Symbol* sym)
2579 {
2580 // An undefined symbol from an executable does not need a PLT entry.
2581 if (sym->is_undefined() && !parameters->options().shared())
2582 return false;
2583
2584 return (!parameters->doing_static_link()
2585 && (sym->type() == elfcpp::STT_FUNC
2586 || sym->type() == elfcpp::STT_ARM_TFUNC)
2587 && (sym->is_from_dynobj()
2588 || sym->is_undefined()
2589 || sym->is_preemptible()));
2590 }
2591
2592 inline bool
2593 possible_function_pointer_reloc(unsigned int r_type);
2594
2595 // Whether we have issued an error about a non-PIC compilation.
2596 bool issued_non_pic_error_;
2597 };
2598
2599 // The class which implements relocation.
2600 class Relocate
2601 {
2602 public:
2603 Relocate()
2604 { }
2605
2606 ~Relocate()
2607 { }
2608
2609 // Return whether the static relocation needs to be applied.
2610 inline bool
2611 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2612 unsigned int r_type,
2613 bool is_32bit,
2614 Output_section* output_section);
2615
2616 // Do a relocation. Return false if the caller should not issue
2617 // any warnings about this relocation.
2618 inline bool
2619 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2620 Output_section*, size_t relnum,
2621 const elfcpp::Rel<32, big_endian>&,
2622 unsigned int r_type, const Sized_symbol<32>*,
2623 const Symbol_value<32>*,
2624 unsigned char*, Arm_address,
2625 section_size_type);
2626
2627 // Return whether we want to pass flag NON_PIC_REF for this
2628 // reloc. This means the relocation type accesses a symbol not via
2629 // GOT or PLT.
2630 static inline bool
2631 reloc_is_non_pic(unsigned int r_type)
2632 {
2633 switch (r_type)
2634 {
2635 // These relocation types reference GOT or PLT entries explicitly.
2636 case elfcpp::R_ARM_GOT_BREL:
2637 case elfcpp::R_ARM_GOT_ABS:
2638 case elfcpp::R_ARM_GOT_PREL:
2639 case elfcpp::R_ARM_GOT_BREL12:
2640 case elfcpp::R_ARM_PLT32_ABS:
2641 case elfcpp::R_ARM_TLS_GD32:
2642 case elfcpp::R_ARM_TLS_LDM32:
2643 case elfcpp::R_ARM_TLS_IE32:
2644 case elfcpp::R_ARM_TLS_IE12GP:
2645
2646 // These relocate types may use PLT entries.
2647 case elfcpp::R_ARM_CALL:
2648 case elfcpp::R_ARM_THM_CALL:
2649 case elfcpp::R_ARM_JUMP24:
2650 case elfcpp::R_ARM_THM_JUMP24:
2651 case elfcpp::R_ARM_THM_JUMP19:
2652 case elfcpp::R_ARM_PLT32:
2653 case elfcpp::R_ARM_THM_XPC22:
2654 case elfcpp::R_ARM_PREL31:
2655 case elfcpp::R_ARM_SBREL31:
2656 return false;
2657
2658 default:
2659 return true;
2660 }
2661 }
2662
2663 private:
2664 // Do a TLS relocation.
2665 inline typename Arm_relocate_functions<big_endian>::Status
2666 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2667 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2668 const Sized_symbol<32>*, const Symbol_value<32>*,
2669 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2670 section_size_type);
2671
2672 };
2673
2674 // A class which returns the size required for a relocation type,
2675 // used while scanning relocs during a relocatable link.
2676 class Relocatable_size_for_reloc
2677 {
2678 public:
2679 unsigned int
2680 get_size_for_reloc(unsigned int, Relobj*);
2681 };
2682
2683 // Adjust TLS relocation type based on the options and whether this
2684 // is a local symbol.
2685 static tls::Tls_optimization
2686 optimize_tls_reloc(bool is_final, int r_type);
2687
2688 // Get the GOT section, creating it if necessary.
2689 Arm_output_data_got<big_endian>*
2690 got_section(Symbol_table*, Layout*);
2691
2692 // Get the GOT PLT section.
2693 Output_data_space*
2694 got_plt_section() const
2695 {
2696 gold_assert(this->got_plt_ != NULL);
2697 return this->got_plt_;
2698 }
2699
2700 // Create a PLT entry for a global symbol.
2701 void
2702 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2703
2704 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2705 void
2706 define_tls_base_symbol(Symbol_table*, Layout*);
2707
2708 // Create a GOT entry for the TLS module index.
2709 unsigned int
2710 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2711 Sized_relobj_file<32, big_endian>* object);
2712
2713 // Get the PLT section.
2714 const Output_data_plt_arm<big_endian>*
2715 plt_section() const
2716 {
2717 gold_assert(this->plt_ != NULL);
2718 return this->plt_;
2719 }
2720
2721 // Get the dynamic reloc section, creating it if necessary.
2722 Reloc_section*
2723 rel_dyn_section(Layout*);
2724
2725 // Get the section to use for TLS_DESC relocations.
2726 Reloc_section*
2727 rel_tls_desc_section(Layout*) const;
2728
2729 // Return true if the symbol may need a COPY relocation.
2730 // References from an executable object to non-function symbols
2731 // defined in a dynamic object may need a COPY relocation.
2732 bool
2733 may_need_copy_reloc(Symbol* gsym)
2734 {
2735 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2736 && gsym->may_need_copy_reloc());
2737 }
2738
2739 // Add a potential copy relocation.
2740 void
2741 copy_reloc(Symbol_table* symtab, Layout* layout,
2742 Sized_relobj_file<32, big_endian>* object,
2743 unsigned int shndx, Output_section* output_section,
2744 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2745 {
2746 this->copy_relocs_.copy_reloc(symtab, layout,
2747 symtab->get_sized_symbol<32>(sym),
2748 object, shndx, output_section, reloc,
2749 this->rel_dyn_section(layout));
2750 }
2751
2752 // Whether two EABI versions are compatible.
2753 static bool
2754 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2755
2756 // Merge processor-specific flags from input object and those in the ELF
2757 // header of the output.
2758 void
2759 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2760
2761 // Get the secondary compatible architecture.
2762 static int
2763 get_secondary_compatible_arch(const Attributes_section_data*);
2764
2765 // Set the secondary compatible architecture.
2766 static void
2767 set_secondary_compatible_arch(Attributes_section_data*, int);
2768
2769 static int
2770 tag_cpu_arch_combine(const char*, int, int*, int, int);
2771
2772 // Helper to print AEABI enum tag value.
2773 static std::string
2774 aeabi_enum_name(unsigned int);
2775
2776 // Return string value for TAG_CPU_name.
2777 static std::string
2778 tag_cpu_name_value(unsigned int);
2779
2780 // Merge object attributes from input object and those in the output.
2781 void
2782 merge_object_attributes(const char*, const Attributes_section_data*);
2783
2784 // Helper to get an AEABI object attribute
2785 Object_attribute*
2786 get_aeabi_object_attribute(int tag) const
2787 {
2788 Attributes_section_data* pasd = this->attributes_section_data_;
2789 gold_assert(pasd != NULL);
2790 Object_attribute* attr =
2791 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2792 gold_assert(attr != NULL);
2793 return attr;
2794 }
2795
2796 //
2797 // Methods to support stub-generations.
2798 //
2799
2800 // Group input sections for stub generation.
2801 void
2802 group_sections(Layout*, section_size_type, bool, const Task*);
2803
2804 // Scan a relocation for stub generation.
2805 void
2806 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2807 const Sized_symbol<32>*, unsigned int,
2808 const Symbol_value<32>*,
2809 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2810
2811 // Scan a relocation section for stub.
2812 template<int sh_type>
2813 void
2814 scan_reloc_section_for_stubs(
2815 const Relocate_info<32, big_endian>* relinfo,
2816 const unsigned char* prelocs,
2817 size_t reloc_count,
2818 Output_section* output_section,
2819 bool needs_special_offset_handling,
2820 const unsigned char* view,
2821 elfcpp::Elf_types<32>::Elf_Addr view_address,
2822 section_size_type);
2823
2824 // Fix .ARM.exidx section coverage.
2825 void
2826 fix_exidx_coverage(Layout*, const Input_objects*,
2827 Arm_output_section<big_endian>*, Symbol_table*,
2828 const Task*);
2829
2830 // Functors for STL set.
2831 struct output_section_address_less_than
2832 {
2833 bool
2834 operator()(const Output_section* s1, const Output_section* s2) const
2835 { return s1->address() < s2->address(); }
2836 };
2837
2838 // Information about this specific target which we pass to the
2839 // general Target structure.
2840 static const Target::Target_info arm_info;
2841
2842 // The types of GOT entries needed for this platform.
2843 // These values are exposed to the ABI in an incremental link.
2844 // Do not renumber existing values without changing the version
2845 // number of the .gnu_incremental_inputs section.
2846 enum Got_type
2847 {
2848 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2849 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2850 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2851 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2852 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2853 };
2854
2855 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2856
2857 // Map input section to Arm_input_section.
2858 typedef Unordered_map<Section_id,
2859 Arm_input_section<big_endian>*,
2860 Section_id_hash>
2861 Arm_input_section_map;
2862
2863 // Map output addresses to relocs for Cortex-A8 erratum.
2864 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2865 Cortex_a8_relocs_info;
2866
2867 // The GOT section.
2868 Arm_output_data_got<big_endian>* got_;
2869 // The PLT section.
2870 Output_data_plt_arm<big_endian>* plt_;
2871 // The GOT PLT section.
2872 Output_data_space* got_plt_;
2873 // The dynamic reloc section.
2874 Reloc_section* rel_dyn_;
2875 // Relocs saved to avoid a COPY reloc.
2876 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2877 // Space for variables copied with a COPY reloc.
2878 Output_data_space* dynbss_;
2879 // Offset of the GOT entry for the TLS module index.
2880 unsigned int got_mod_index_offset_;
2881 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2882 bool tls_base_symbol_defined_;
2883 // Vector of Stub_tables created.
2884 Stub_table_list stub_tables_;
2885 // Stub factory.
2886 const Stub_factory &stub_factory_;
2887 // Whether we force PIC branch veneers.
2888 bool should_force_pic_veneer_;
2889 // Map for locating Arm_input_sections.
2890 Arm_input_section_map arm_input_section_map_;
2891 // Attributes section data in output.
2892 Attributes_section_data* attributes_section_data_;
2893 // Whether we want to fix code for Cortex-A8 erratum.
2894 bool fix_cortex_a8_;
2895 // Map addresses to relocs for Cortex-A8 erratum.
2896 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2897 };
2898
2899 template<bool big_endian>
2900 const Target::Target_info Target_arm<big_endian>::arm_info =
2901 {
2902 32, // size
2903 big_endian, // is_big_endian
2904 elfcpp::EM_ARM, // machine_code
2905 false, // has_make_symbol
2906 false, // has_resolve
2907 false, // has_code_fill
2908 true, // is_default_stack_executable
2909 false, // can_icf_inline_merge_sections
2910 '\0', // wrap_char
2911 "/usr/lib/libc.so.1", // dynamic_linker
2912 0x8000, // default_text_segment_address
2913 0x1000, // abi_pagesize (overridable by -z max-page-size)
2914 0x1000, // common_pagesize (overridable by -z common-page-size)
2915 elfcpp::SHN_UNDEF, // small_common_shndx
2916 elfcpp::SHN_UNDEF, // large_common_shndx
2917 0, // small_common_section_flags
2918 0, // large_common_section_flags
2919 ".ARM.attributes", // attributes_section
2920 "aeabi" // attributes_vendor
2921 };
2922
2923 // Arm relocate functions class
2924 //
2925
2926 template<bool big_endian>
2927 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2928 {
2929 public:
2930 typedef enum
2931 {
2932 STATUS_OKAY, // No error during relocation.
2933 STATUS_OVERFLOW, // Relocation overflow.
2934 STATUS_BAD_RELOC // Relocation cannot be applied.
2935 } Status;
2936
2937 private:
2938 typedef Relocate_functions<32, big_endian> Base;
2939 typedef Arm_relocate_functions<big_endian> This;
2940
2941 // Encoding of imm16 argument for movt and movw ARM instructions
2942 // from ARM ARM:
2943 //
2944 // imm16 := imm4 | imm12
2945 //
2946 // 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
2947 // +-------+---------------+-------+-------+-----------------------+
2948 // | | |imm4 | |imm12 |
2949 // +-------+---------------+-------+-------+-----------------------+
2950
2951 // Extract the relocation addend from VAL based on the ARM
2952 // instruction encoding described above.
2953 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2954 extract_arm_movw_movt_addend(
2955 typename elfcpp::Swap<32, big_endian>::Valtype val)
2956 {
2957 // According to the Elf ABI for ARM Architecture the immediate
2958 // field is sign-extended to form the addend.
2959 return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2960 }
2961
2962 // Insert X into VAL based on the ARM instruction encoding described
2963 // above.
2964 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2965 insert_val_arm_movw_movt(
2966 typename elfcpp::Swap<32, big_endian>::Valtype val,
2967 typename elfcpp::Swap<32, big_endian>::Valtype x)
2968 {
2969 val &= 0xfff0f000;
2970 val |= x & 0x0fff;
2971 val |= (x & 0xf000) << 4;
2972 return val;
2973 }
2974
2975 // Encoding of imm16 argument for movt and movw Thumb2 instructions
2976 // from ARM ARM:
2977 //
2978 // imm16 := imm4 | i | imm3 | imm8
2979 //
2980 // f e d c b a 9 8 7 6 5 4 3 2 1 0 f e d c b a 9 8 7 6 5 4 3 2 1 0
2981 // +---------+-+-----------+-------++-+-----+-------+---------------+
2982 // | |i| |imm4 || |imm3 | |imm8 |
2983 // +---------+-+-----------+-------++-+-----+-------+---------------+
2984
2985 // Extract the relocation addend from VAL based on the Thumb2
2986 // instruction encoding described above.
2987 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2988 extract_thumb_movw_movt_addend(
2989 typename elfcpp::Swap<32, big_endian>::Valtype val)
2990 {
2991 // According to the Elf ABI for ARM Architecture the immediate
2992 // field is sign-extended to form the addend.
2993 return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
2994 | ((val >> 15) & 0x0800)
2995 | ((val >> 4) & 0x0700)
2996 | (val & 0x00ff));
2997 }
2998
2999 // Insert X into VAL based on the Thumb2 instruction encoding
3000 // described above.
3001 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3002 insert_val_thumb_movw_movt(
3003 typename elfcpp::Swap<32, big_endian>::Valtype val,
3004 typename elfcpp::Swap<32, big_endian>::Valtype x)
3005 {
3006 val &= 0xfbf08f00;
3007 val |= (x & 0xf000) << 4;
3008 val |= (x & 0x0800) << 15;
3009 val |= (x & 0x0700) << 4;
3010 val |= (x & 0x00ff);
3011 return val;
3012 }
3013
3014 // Calculate the smallest constant Kn for the specified residual.
3015 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3016 static uint32_t
3017 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3018 {
3019 int32_t msb;
3020
3021 if (residual == 0)
3022 return 0;
3023 // Determine the most significant bit in the residual and
3024 // align the resulting value to a 2-bit boundary.
3025 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3026 ;
3027 // The desired shift is now (msb - 6), or zero, whichever
3028 // is the greater.
3029 return (((msb - 6) < 0) ? 0 : (msb - 6));
3030 }
3031
3032 // Calculate the final residual for the specified group index.
3033 // If the passed group index is less than zero, the method will return
3034 // the value of the specified residual without any change.
3035 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3036 static typename elfcpp::Swap<32, big_endian>::Valtype
3037 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3038 const int group)
3039 {
3040 for (int n = 0; n <= group; n++)
3041 {
3042 // Calculate which part of the value to mask.
3043 uint32_t shift = calc_grp_kn(residual);
3044 // Calculate the residual for the next time around.
3045 residual &= ~(residual & (0xff << shift));
3046 }
3047
3048 return residual;
3049 }
3050
3051 // Calculate the value of Gn for the specified group index.
3052 // We return it in the form of an encoded constant-and-rotation.
3053 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3054 static typename elfcpp::Swap<32, big_endian>::Valtype
3055 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3056 const int group)
3057 {
3058 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3059 uint32_t shift = 0;
3060
3061 for (int n = 0; n <= group; n++)
3062 {
3063 // Calculate which part of the value to mask.
3064 shift = calc_grp_kn(residual);
3065 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3066 gn = residual & (0xff << shift);
3067 // Calculate the residual for the next time around.
3068 residual &= ~gn;
3069 }
3070 // Return Gn in the form of an encoded constant-and-rotation.
3071 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3072 }
3073
3074 public:
3075 // Handle ARM long branches.
3076 static typename This::Status
3077 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3078 unsigned char*, const Sized_symbol<32>*,
3079 const Arm_relobj<big_endian>*, unsigned int,
3080 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3081
3082 // Handle THUMB long branches.
3083 static typename This::Status
3084 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3085 unsigned char*, const Sized_symbol<32>*,
3086 const Arm_relobj<big_endian>*, unsigned int,
3087 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3088
3089
3090 // Return the branch offset of a 32-bit THUMB branch.
3091 static inline int32_t
3092 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3093 {
3094 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3095 // involving the J1 and J2 bits.
3096 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3097 uint32_t upper = upper_insn & 0x3ffU;
3098 uint32_t lower = lower_insn & 0x7ffU;
3099 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3100 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3101 uint32_t i1 = j1 ^ s ? 0 : 1;
3102 uint32_t i2 = j2 ^ s ? 0 : 1;
3103
3104 return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3105 | (upper << 12) | (lower << 1));
3106 }
3107
3108 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3109 // UPPER_INSN is the original upper instruction of the branch. Caller is
3110 // responsible for overflow checking and BLX offset adjustment.
3111 static inline uint16_t
3112 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3113 {
3114 uint32_t s = offset < 0 ? 1 : 0;
3115 uint32_t bits = static_cast<uint32_t>(offset);
3116 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3117 }
3118
3119 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3120 // LOWER_INSN is the original lower instruction of the branch. Caller is
3121 // responsible for overflow checking and BLX offset adjustment.
3122 static inline uint16_t
3123 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3124 {
3125 uint32_t s = offset < 0 ? 1 : 0;
3126 uint32_t bits = static_cast<uint32_t>(offset);
3127 return ((lower_insn & ~0x2fffU)
3128 | ((((bits >> 23) & 1) ^ !s) << 13)
3129 | ((((bits >> 22) & 1) ^ !s) << 11)
3130 | ((bits >> 1) & 0x7ffU));
3131 }
3132
3133 // Return the branch offset of a 32-bit THUMB conditional branch.
3134 static inline int32_t
3135 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3136 {
3137 uint32_t s = (upper_insn & 0x0400U) >> 10;
3138 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3139 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3140 uint32_t lower = (lower_insn & 0x07ffU);
3141 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3142
3143 return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3144 }
3145
3146 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3147 // instruction. UPPER_INSN is the original upper instruction of the branch.
3148 // Caller is responsible for overflow checking.
3149 static inline uint16_t
3150 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3151 {
3152 uint32_t s = offset < 0 ? 1 : 0;
3153 uint32_t bits = static_cast<uint32_t>(offset);
3154 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3155 }
3156
3157 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3158 // instruction. LOWER_INSN is the original lower instruction of the branch.
3159 // The caller is responsible for overflow checking.
3160 static inline uint16_t
3161 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3162 {
3163 uint32_t bits = static_cast<uint32_t>(offset);
3164 uint32_t j2 = (bits & 0x00080000U) >> 19;
3165 uint32_t j1 = (bits & 0x00040000U) >> 18;
3166 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3167
3168 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3169 }
3170
3171 // R_ARM_ABS8: S + A
3172 static inline typename This::Status
3173 abs8(unsigned char* view,
3174 const Sized_relobj_file<32, big_endian>* object,
3175 const Symbol_value<32>* psymval)
3176 {
3177 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3178 Valtype* wv = reinterpret_cast<Valtype*>(view);
3179 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3180 int32_t addend = Bits<8>::sign_extend32(val);
3181 Arm_address x = psymval->value(object, addend);
3182 val = Bits<32>::bit_select32(val, x, 0xffU);
3183 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3184
3185 // R_ARM_ABS8 permits signed or unsigned results.
3186 int signed_x = static_cast<int32_t>(x);
3187 return ((signed_x < -128 || signed_x > 255)
3188 ? This::STATUS_OVERFLOW
3189 : This::STATUS_OKAY);
3190 }
3191
3192 // R_ARM_THM_ABS5: S + A
3193 static inline typename This::Status
3194 thm_abs5(unsigned char* view,
3195 const Sized_relobj_file<32, big_endian>* object,
3196 const Symbol_value<32>* psymval)
3197 {
3198 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3199 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3200 Valtype* wv = reinterpret_cast<Valtype*>(view);
3201 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3202 Reltype addend = (val & 0x7e0U) >> 6;
3203 Reltype x = psymval->value(object, addend);
3204 val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3205 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3206
3207 // R_ARM_ABS16 permits signed or unsigned results.
3208 int signed_x = static_cast<int32_t>(x);
3209 return ((signed_x < -32768 || signed_x > 65535)
3210 ? This::STATUS_OVERFLOW
3211 : This::STATUS_OKAY);
3212 }
3213
3214 // R_ARM_ABS12: S + A
3215 static inline typename This::Status
3216 abs12(unsigned char* view,
3217 const Sized_relobj_file<32, big_endian>* object,
3218 const Symbol_value<32>* psymval)
3219 {
3220 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3221 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3222 Valtype* wv = reinterpret_cast<Valtype*>(view);
3223 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3224 Reltype addend = val & 0x0fffU;
3225 Reltype x = psymval->value(object, addend);
3226 val = Bits<32>::bit_select32(val, x, 0x0fffU);
3227 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3228 return (Bits<12>::has_overflow32(x)
3229 ? This::STATUS_OVERFLOW
3230 : This::STATUS_OKAY);
3231 }
3232
3233 // R_ARM_ABS16: S + A
3234 static inline typename This::Status
3235 abs16(unsigned char* view,
3236 const Sized_relobj_file<32, big_endian>* object,
3237 const Symbol_value<32>* psymval)
3238 {
3239 typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3240 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3241 Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3242 int32_t addend = Bits<16>::sign_extend32(val);
3243 Arm_address x = psymval->value(object, addend);
3244 val = Bits<32>::bit_select32(val, x, 0xffffU);
3245 elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3246
3247 // R_ARM_ABS16 permits signed or unsigned results.
3248 int signed_x = static_cast<int32_t>(x);
3249 return ((signed_x < -32768 || signed_x > 65536)
3250 ? This::STATUS_OVERFLOW
3251 : This::STATUS_OKAY);
3252 }
3253
3254 // R_ARM_ABS32: (S + A) | T
3255 static inline typename This::Status
3256 abs32(unsigned char* view,
3257 const Sized_relobj_file<32, big_endian>* object,
3258 const Symbol_value<32>* psymval,
3259 Arm_address thumb_bit)
3260 {
3261 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3262 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3263 Valtype x = psymval->value(object, addend) | thumb_bit;
3264 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3265 return This::STATUS_OKAY;
3266 }
3267
3268 // R_ARM_REL32: (S + A) | T - P
3269 static inline typename This::Status
3270 rel32(unsigned char* view,
3271 const Sized_relobj_file<32, big_endian>* object,
3272 const Symbol_value<32>* psymval,
3273 Arm_address address,
3274 Arm_address thumb_bit)
3275 {
3276 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3277 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3278 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3279 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3280 return This::STATUS_OKAY;
3281 }
3282
3283 // R_ARM_THM_JUMP24: (S + A) | T - P
3284 static typename This::Status
3285 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3286 const Symbol_value<32>* psymval, Arm_address address,
3287 Arm_address thumb_bit);
3288
3289 // R_ARM_THM_JUMP6: S + A – P
3290 static inline typename This::Status
3291 thm_jump6(unsigned char* view,
3292 const Sized_relobj_file<32, big_endian>* object,
3293 const Symbol_value<32>* psymval,
3294 Arm_address address)
3295 {
3296 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3297 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3298 Valtype* wv = reinterpret_cast<Valtype*>(view);
3299 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3300 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3301 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3302 Reltype x = (psymval->value(object, addend) - address);
3303 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3304 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3305 // CZB does only forward jumps.
3306 return ((x > 0x007e)
3307 ? This::STATUS_OVERFLOW
3308 : This::STATUS_OKAY);
3309 }
3310
3311 // R_ARM_THM_JUMP8: S + A – P
3312 static inline typename This::Status
3313 thm_jump8(unsigned char* view,
3314 const Sized_relobj_file<32, big_endian>* object,
3315 const Symbol_value<32>* psymval,
3316 Arm_address address)
3317 {
3318 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3319 Valtype* wv = reinterpret_cast<Valtype*>(view);
3320 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3321 int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3322 int32_t x = (psymval->value(object, addend) - address);
3323 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3324 | ((x & 0x01fe) >> 1)));
3325 // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3326 return (Bits<9>::has_overflow32(x)
3327 ? This::STATUS_OVERFLOW
3328 : This::STATUS_OKAY);
3329 }
3330
3331 // R_ARM_THM_JUMP11: S + A – P
3332 static inline typename This::Status
3333 thm_jump11(unsigned char* view,
3334 const Sized_relobj_file<32, big_endian>* object,
3335 const Symbol_value<32>* psymval,
3336 Arm_address address)
3337 {
3338 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3339 Valtype* wv = reinterpret_cast<Valtype*>(view);
3340 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3341 int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3342 int32_t x = (psymval->value(object, addend) - address);
3343 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3344 | ((x & 0x0ffe) >> 1)));
3345 // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3346 return (Bits<12>::has_overflow32(x)
3347 ? This::STATUS_OVERFLOW
3348 : This::STATUS_OKAY);
3349 }
3350
3351 // R_ARM_BASE_PREL: B(S) + A - P
3352 static inline typename This::Status
3353 base_prel(unsigned char* view,
3354 Arm_address origin,
3355 Arm_address address)
3356 {
3357 Base::rel32(view, origin - address);
3358 return STATUS_OKAY;
3359 }
3360
3361 // R_ARM_BASE_ABS: B(S) + A
3362 static inline typename This::Status
3363 base_abs(unsigned char* view,
3364 Arm_address origin)
3365 {
3366 Base::rel32(view, origin);
3367 return STATUS_OKAY;
3368 }
3369
3370 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3371 static inline typename This::Status
3372 got_brel(unsigned char* view,
3373 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3374 {
3375 Base::rel32(view, got_offset);
3376 return This::STATUS_OKAY;
3377 }
3378
3379 // R_ARM_GOT_PREL: GOT(S) + A - P
3380 static inline typename This::Status
3381 got_prel(unsigned char* view,
3382 Arm_address got_entry,
3383 Arm_address address)
3384 {
3385 Base::rel32(view, got_entry - address);
3386 return This::STATUS_OKAY;
3387 }
3388
3389 // R_ARM_PREL: (S + A) | T - P
3390 static inline typename This::Status
3391 prel31(unsigned char* view,
3392 const Sized_relobj_file<32, big_endian>* object,
3393 const Symbol_value<32>* psymval,
3394 Arm_address address,
3395 Arm_address thumb_bit)
3396 {
3397 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3398 Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3399 Valtype addend = Bits<31>::sign_extend32(val);
3400 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3401 val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3402 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3403 return (Bits<31>::has_overflow32(x)
3404 ? This::STATUS_OVERFLOW
3405 : This::STATUS_OKAY);
3406 }
3407
3408 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3409 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3410 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3411 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3412 static inline typename This::Status
3413 movw(unsigned char* view,
3414 const Sized_relobj_file<32, big_endian>* object,
3415 const Symbol_value<32>* psymval,
3416 Arm_address relative_address_base,
3417 Arm_address thumb_bit,
3418 bool check_overflow)
3419 {
3420 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3421 Valtype* wv = reinterpret_cast<Valtype*>(view);
3422 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3423 Valtype addend = This::extract_arm_movw_movt_addend(val);
3424 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3425 - relative_address_base);
3426 val = This::insert_val_arm_movw_movt(val, x);
3427 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3428 return ((check_overflow && Bits<16>::has_overflow32(x))
3429 ? This::STATUS_OVERFLOW
3430 : This::STATUS_OKAY);
3431 }
3432
3433 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3434 // R_ARM_MOVT_PREL: S + A - P
3435 // R_ARM_MOVT_BREL: S + A - B(S)
3436 static inline typename This::Status
3437 movt(unsigned char* view,
3438 const Sized_relobj_file<32, big_endian>* object,
3439 const Symbol_value<32>* psymval,
3440 Arm_address relative_address_base)
3441 {
3442 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3443 Valtype* wv = reinterpret_cast<Valtype*>(view);
3444 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3445 Valtype addend = This::extract_arm_movw_movt_addend(val);
3446 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3447 val = This::insert_val_arm_movw_movt(val, x);
3448 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3449 // FIXME: IHI0044D says that we should check for overflow.
3450 return This::STATUS_OKAY;
3451 }
3452
3453 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3454 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3455 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3456 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3457 static inline typename This::Status
3458 thm_movw(unsigned char* view,
3459 const Sized_relobj_file<32, big_endian>* object,
3460 const Symbol_value<32>* psymval,
3461 Arm_address relative_address_base,
3462 Arm_address thumb_bit,
3463 bool check_overflow)
3464 {
3465 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3466 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3467 Valtype* wv = reinterpret_cast<Valtype*>(view);
3468 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3469 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3470 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3471 Reltype x =
3472 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3473 val = This::insert_val_thumb_movw_movt(val, x);
3474 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3475 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3476 return ((check_overflow && Bits<16>::has_overflow32(x))
3477 ? This::STATUS_OVERFLOW
3478 : This::STATUS_OKAY);
3479 }
3480
3481 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3482 // R_ARM_THM_MOVT_PREL: S + A - P
3483 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3484 static inline typename This::Status
3485 thm_movt(unsigned char* view,
3486 const Sized_relobj_file<32, big_endian>* object,
3487 const Symbol_value<32>* psymval,
3488 Arm_address relative_address_base)
3489 {
3490 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3491 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3492 Valtype* wv = reinterpret_cast<Valtype*>(view);
3493 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3494 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3495 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3496 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3497 val = This::insert_val_thumb_movw_movt(val, x);
3498 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3499 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3500 return This::STATUS_OKAY;
3501 }
3502
3503 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3504 static inline typename This::Status
3505 thm_alu11(unsigned char* view,
3506 const Sized_relobj_file<32, big_endian>* object,
3507 const Symbol_value<32>* psymval,
3508 Arm_address address,
3509 Arm_address thumb_bit)
3510 {
3511 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3512 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3513 Valtype* wv = reinterpret_cast<Valtype*>(view);
3514 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3515 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3516
3517 // 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
3518 // -----------------------------------------------------------------------
3519 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3520 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3521 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3522 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3523 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3524 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3525
3526 // Determine a sign for the addend.
3527 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3528 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3529 // Thumb2 addend encoding:
3530 // imm12 := i | imm3 | imm8
3531 int32_t addend = (insn & 0xff)
3532 | ((insn & 0x00007000) >> 4)
3533 | ((insn & 0x04000000) >> 15);
3534 // Apply a sign to the added.
3535 addend *= sign;
3536
3537 int32_t x = (psymval->value(object, addend) | thumb_bit)
3538 - (address & 0xfffffffc);
3539 Reltype val = abs(x);
3540 // Mask out the value and a distinct part of the ADD/SUB opcode
3541 // (bits 7:5 of opword).
3542 insn = (insn & 0xfb0f8f00)
3543 | (val & 0xff)
3544 | ((val & 0x700) << 4)
3545 | ((val & 0x800) << 15);
3546 // Set the opcode according to whether the value to go in the
3547 // place is negative.
3548 if (x < 0)
3549 insn |= 0x00a00000;
3550
3551 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3552 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3553 return ((val > 0xfff) ?
3554 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3555 }
3556
3557 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3558 static inline typename This::Status
3559 thm_pc8(unsigned char* view,
3560 const Sized_relobj_file<32, big_endian>* object,
3561 const Symbol_value<32>* psymval,
3562 Arm_address address)
3563 {
3564 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3565 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3566 Valtype* wv = reinterpret_cast<Valtype*>(view);
3567 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3568 Reltype addend = ((insn & 0x00ff) << 2);
3569 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3570 Reltype val = abs(x);
3571 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3572
3573 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3574 return ((val > 0x03fc)
3575 ? This::STATUS_OVERFLOW
3576 : This::STATUS_OKAY);
3577 }
3578
3579 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3580 static inline typename This::Status
3581 thm_pc12(unsigned char* view,
3582 const Sized_relobj_file<32, big_endian>* object,
3583 const Symbol_value<32>* psymval,
3584 Arm_address address)
3585 {
3586 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3587 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3588 Valtype* wv = reinterpret_cast<Valtype*>(view);
3589 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3590 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3591 // Determine a sign for the addend (positive if the U bit is 1).
3592 const int sign = (insn & 0x00800000) ? 1 : -1;
3593 int32_t addend = (insn & 0xfff);
3594 // Apply a sign to the added.
3595 addend *= sign;
3596
3597 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3598 Reltype val = abs(x);
3599 // Mask out and apply the value and the U bit.
3600 insn = (insn & 0xff7ff000) | (val & 0xfff);
3601 // Set the U bit according to whether the value to go in the
3602 // place is positive.
3603 if (x >= 0)
3604 insn |= 0x00800000;
3605
3606 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3607 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3608 return ((val > 0xfff) ?
3609 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3610 }
3611
3612 // R_ARM_V4BX
3613 static inline typename This::Status
3614 v4bx(const Relocate_info<32, big_endian>* relinfo,
3615 unsigned char* view,
3616 const Arm_relobj<big_endian>* object,
3617 const Arm_address address,
3618 const bool is_interworking)
3619 {
3620
3621 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3622 Valtype* wv = reinterpret_cast<Valtype*>(view);
3623 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3624
3625 // Ensure that we have a BX instruction.
3626 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3627 const uint32_t reg = (val & 0xf);
3628 if (is_interworking && reg != 0xf)
3629 {
3630 Stub_table<big_endian>* stub_table =
3631 object->stub_table(relinfo->data_shndx);
3632 gold_assert(stub_table != NULL);
3633
3634 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3635 gold_assert(stub != NULL);
3636
3637 int32_t veneer_address =
3638 stub_table->address() + stub->offset() - 8 - address;
3639 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3640 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3641 // Replace with a branch to veneer (B <addr>)
3642 val = (val & 0xf0000000) | 0x0a000000
3643 | ((veneer_address >> 2) & 0x00ffffff);
3644 }
3645 else
3646 {
3647 // Preserve Rm (lowest four bits) and the condition code
3648 // (highest four bits). Other bits encode MOV PC,Rm.
3649 val = (val & 0xf000000f) | 0x01a0f000;
3650 }
3651 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3652 return This::STATUS_OKAY;
3653 }
3654
3655 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3656 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3657 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3658 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3659 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3660 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3661 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3662 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3663 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3664 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3665 static inline typename This::Status
3666 arm_grp_alu(unsigned char* view,
3667 const Sized_relobj_file<32, big_endian>* object,
3668 const Symbol_value<32>* psymval,
3669 const int group,
3670 Arm_address address,
3671 Arm_address thumb_bit,
3672 bool check_overflow)
3673 {
3674 gold_assert(group >= 0 && group < 3);
3675 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3676 Valtype* wv = reinterpret_cast<Valtype*>(view);
3677 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3678
3679 // ALU group relocations are allowed only for the ADD/SUB instructions.
3680 // (0x00800000 - ADD, 0x00400000 - SUB)
3681 const Valtype opcode = insn & 0x01e00000;
3682 if (opcode != 0x00800000 && opcode != 0x00400000)
3683 return This::STATUS_BAD_RELOC;
3684
3685 // Determine a sign for the addend.
3686 const int sign = (opcode == 0x00800000) ? 1 : -1;
3687 // shifter = rotate_imm * 2
3688 const uint32_t shifter = (insn & 0xf00) >> 7;
3689 // Initial addend value.
3690 int32_t addend = insn & 0xff;
3691 // Rotate addend right by shifter.
3692 addend = (addend >> shifter) | (addend << (32 - shifter));
3693 // Apply a sign to the added.
3694 addend *= sign;
3695
3696 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3697 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3698 // Check for overflow if required
3699 if (check_overflow
3700 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3701 return This::STATUS_OVERFLOW;
3702
3703 // Mask out the value and the ADD/SUB part of the opcode; take care
3704 // not to destroy the S bit.
3705 insn &= 0xff1ff000;
3706 // Set the opcode according to whether the value to go in the
3707 // place is negative.
3708 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3709 // Encode the offset (encoded Gn).
3710 insn |= gn;
3711
3712 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3713 return This::STATUS_OKAY;
3714 }
3715
3716 // R_ARM_LDR_PC_G0: S + A - P
3717 // R_ARM_LDR_PC_G1: S + A - P
3718 // R_ARM_LDR_PC_G2: S + A - P
3719 // R_ARM_LDR_SB_G0: S + A - B(S)
3720 // R_ARM_LDR_SB_G1: S + A - B(S)
3721 // R_ARM_LDR_SB_G2: S + A - B(S)
3722 static inline typename This::Status
3723 arm_grp_ldr(unsigned char* view,
3724 const Sized_relobj_file<32, big_endian>* object,
3725 const Symbol_value<32>* psymval,
3726 const int group,
3727 Arm_address address)
3728 {
3729 gold_assert(group >= 0 && group < 3);
3730 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3731 Valtype* wv = reinterpret_cast<Valtype*>(view);
3732 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3733
3734 const int sign = (insn & 0x00800000) ? 1 : -1;
3735 int32_t addend = (insn & 0xfff) * sign;
3736 int32_t x = (psymval->value(object, addend) - address);
3737 // Calculate the relevant G(n-1) value to obtain this stage residual.
3738 Valtype residual =
3739 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3740 if (residual >= 0x1000)
3741 return This::STATUS_OVERFLOW;
3742
3743 // Mask out the value and U bit.
3744 insn &= 0xff7ff000;
3745 // Set the U bit for non-negative values.
3746 if (x >= 0)
3747 insn |= 0x00800000;
3748 insn |= residual;
3749
3750 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3751 return This::STATUS_OKAY;
3752 }
3753
3754 // R_ARM_LDRS_PC_G0: S + A - P
3755 // R_ARM_LDRS_PC_G1: S + A - P
3756 // R_ARM_LDRS_PC_G2: S + A - P
3757 // R_ARM_LDRS_SB_G0: S + A - B(S)
3758 // R_ARM_LDRS_SB_G1: S + A - B(S)
3759 // R_ARM_LDRS_SB_G2: S + A - B(S)
3760 static inline typename This::Status
3761 arm_grp_ldrs(unsigned char* view,
3762 const Sized_relobj_file<32, big_endian>* object,
3763 const Symbol_value<32>* psymval,
3764 const int group,
3765 Arm_address address)
3766 {
3767 gold_assert(group >= 0 && group < 3);
3768 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3769 Valtype* wv = reinterpret_cast<Valtype*>(view);
3770 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3771
3772 const int sign = (insn & 0x00800000) ? 1 : -1;
3773 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3774 int32_t x = (psymval->value(object, addend) - address);
3775 // Calculate the relevant G(n-1) value to obtain this stage residual.
3776 Valtype residual =
3777 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3778 if (residual >= 0x100)
3779 return This::STATUS_OVERFLOW;
3780
3781 // Mask out the value and U bit.
3782 insn &= 0xff7ff0f0;
3783 // Set the U bit for non-negative values.
3784 if (x >= 0)
3785 insn |= 0x00800000;
3786 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3787
3788 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3789 return This::STATUS_OKAY;
3790 }
3791
3792 // R_ARM_LDC_PC_G0: S + A - P
3793 // R_ARM_LDC_PC_G1: S + A - P
3794 // R_ARM_LDC_PC_G2: S + A - P
3795 // R_ARM_LDC_SB_G0: S + A - B(S)
3796 // R_ARM_LDC_SB_G1: S + A - B(S)
3797 // R_ARM_LDC_SB_G2: S + A - B(S)
3798 static inline typename This::Status
3799 arm_grp_ldc(unsigned char* view,
3800 const Sized_relobj_file<32, big_endian>* object,
3801 const Symbol_value<32>* psymval,
3802 const int group,
3803 Arm_address address)
3804 {
3805 gold_assert(group >= 0 && group < 3);
3806 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3807 Valtype* wv = reinterpret_cast<Valtype*>(view);
3808 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3809
3810 const int sign = (insn & 0x00800000) ? 1 : -1;
3811 int32_t addend = ((insn & 0xff) << 2) * sign;
3812 int32_t x = (psymval->value(object, addend) - address);
3813 // Calculate the relevant G(n-1) value to obtain this stage residual.
3814 Valtype residual =
3815 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3816 if ((residual & 0x3) != 0 || residual >= 0x400)
3817 return This::STATUS_OVERFLOW;
3818
3819 // Mask out the value and U bit.
3820 insn &= 0xff7fff00;
3821 // Set the U bit for non-negative values.
3822 if (x >= 0)
3823 insn |= 0x00800000;
3824 insn |= (residual >> 2);
3825
3826 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3827 return This::STATUS_OKAY;
3828 }
3829 };
3830
3831 // Relocate ARM long branches. This handles relocation types
3832 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3833 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3834 // undefined and we do not use PLT in this relocation. In such a case,
3835 // the branch is converted into an NOP.
3836
3837 template<bool big_endian>
3838 typename Arm_relocate_functions<big_endian>::Status
3839 Arm_relocate_functions<big_endian>::arm_branch_common(
3840 unsigned int r_type,
3841 const Relocate_info<32, big_endian>* relinfo,
3842 unsigned char* view,
3843 const Sized_symbol<32>* gsym,
3844 const Arm_relobj<big_endian>* object,
3845 unsigned int r_sym,
3846 const Symbol_value<32>* psymval,
3847 Arm_address address,
3848 Arm_address thumb_bit,
3849 bool is_weakly_undefined_without_plt)
3850 {
3851 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3852 Valtype* wv = reinterpret_cast<Valtype*>(view);
3853 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3854
3855 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3856 && ((val & 0x0f000000UL) == 0x0a000000UL);
3857 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3858 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3859 && ((val & 0x0f000000UL) == 0x0b000000UL);
3860 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3861 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3862
3863 // Check that the instruction is valid.
3864 if (r_type == elfcpp::R_ARM_CALL)
3865 {
3866 if (!insn_is_uncond_bl && !insn_is_blx)
3867 return This::STATUS_BAD_RELOC;
3868 }
3869 else if (r_type == elfcpp::R_ARM_JUMP24)
3870 {
3871 if (!insn_is_b && !insn_is_cond_bl)
3872 return This::STATUS_BAD_RELOC;
3873 }
3874 else if (r_type == elfcpp::R_ARM_PLT32)
3875 {
3876 if (!insn_is_any_branch)
3877 return This::STATUS_BAD_RELOC;
3878 }
3879 else if (r_type == elfcpp::R_ARM_XPC25)
3880 {
3881 // FIXME: AAELF document IH0044C does not say much about it other
3882 // than it being obsolete.
3883 if (!insn_is_any_branch)
3884 return This::STATUS_BAD_RELOC;
3885 }
3886 else
3887 gold_unreachable();
3888
3889 // A branch to an undefined weak symbol is turned into a jump to
3890 // the next instruction unless a PLT entry will be created.
3891 // Do the same for local undefined symbols.
3892 // The jump to the next instruction is optimized as a NOP depending
3893 // on the architecture.
3894 const Target_arm<big_endian>* arm_target =
3895 Target_arm<big_endian>::default_target();
3896 if (is_weakly_undefined_without_plt)
3897 {
3898 gold_assert(!parameters->options().relocatable());
3899 Valtype cond = val & 0xf0000000U;
3900 if (arm_target->may_use_arm_nop())
3901 val = cond | 0x0320f000;
3902 else
3903 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3904 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3905 return This::STATUS_OKAY;
3906 }
3907
3908 Valtype addend = Bits<26>::sign_extend32(val << 2);
3909 Valtype branch_target = psymval->value(object, addend);
3910 int32_t branch_offset = branch_target - address;
3911
3912 // We need a stub if the branch offset is too large or if we need
3913 // to switch mode.
3914 bool may_use_blx = arm_target->may_use_v5t_interworking();
3915 Reloc_stub* stub = NULL;
3916
3917 if (!parameters->options().relocatable()
3918 && (Bits<26>::has_overflow32(branch_offset)
3919 || ((thumb_bit != 0)
3920 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3921 {
3922 Valtype unadjusted_branch_target = psymval->value(object, 0);
3923
3924 Stub_type stub_type =
3925 Reloc_stub::stub_type_for_reloc(r_type, address,
3926 unadjusted_branch_target,
3927 (thumb_bit != 0));
3928 if (stub_type != arm_stub_none)
3929 {
3930 Stub_table<big_endian>* stub_table =
3931 object->stub_table(relinfo->data_shndx);
3932 gold_assert(stub_table != NULL);
3933
3934 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3935 stub = stub_table->find_reloc_stub(stub_key);
3936 gold_assert(stub != NULL);
3937 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3938 branch_target = stub_table->address() + stub->offset() + addend;
3939 branch_offset = branch_target - address;
3940 gold_assert(!Bits<26>::has_overflow32(branch_offset));
3941 }
3942 }
3943
3944 // At this point, if we still need to switch mode, the instruction
3945 // must either be a BLX or a BL that can be converted to a BLX.
3946 if (thumb_bit != 0)
3947 {
3948 // Turn BL to BLX.
3949 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3950 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3951 }
3952
3953 val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3954 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3955 return (Bits<26>::has_overflow32(branch_offset)
3956 ? This::STATUS_OVERFLOW
3957 : This::STATUS_OKAY);
3958 }
3959
3960 // Relocate THUMB long branches. This handles relocation types
3961 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3962 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3963 // undefined and we do not use PLT in this relocation. In such a case,
3964 // the branch is converted into an NOP.
3965
3966 template<bool big_endian>
3967 typename Arm_relocate_functions<big_endian>::Status
3968 Arm_relocate_functions<big_endian>::thumb_branch_common(
3969 unsigned int r_type,
3970 const Relocate_info<32, big_endian>* relinfo,
3971 unsigned char* view,
3972 const Sized_symbol<32>* gsym,
3973 const Arm_relobj<big_endian>* object,
3974 unsigned int r_sym,
3975 const Symbol_value<32>* psymval,
3976 Arm_address address,
3977 Arm_address thumb_bit,
3978 bool is_weakly_undefined_without_plt)
3979 {
3980 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3981 Valtype* wv = reinterpret_cast<Valtype*>(view);
3982 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3983 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3984
3985 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
3986 // into account.
3987 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
3988 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
3989
3990 // Check that the instruction is valid.
3991 if (r_type == elfcpp::R_ARM_THM_CALL)
3992 {
3993 if (!is_bl_insn && !is_blx_insn)
3994 return This::STATUS_BAD_RELOC;
3995 }
3996 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
3997 {
3998 // This cannot be a BLX.
3999 if (!is_bl_insn)
4000 return This::STATUS_BAD_RELOC;
4001 }
4002 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4003 {
4004 // Check for Thumb to Thumb call.
4005 if (!is_blx_insn)
4006 return This::STATUS_BAD_RELOC;
4007 if (thumb_bit != 0)
4008 {
4009 gold_warning(_("%s: Thumb BLX instruction targets "
4010 "thumb function '%s'."),
4011 object->name().c_str(),
4012 (gsym ? gsym->name() : "(local)"));
4013 // Convert BLX to BL.
4014 lower_insn |= 0x1000U;
4015 }
4016 }
4017 else
4018 gold_unreachable();
4019
4020 // A branch to an undefined weak symbol is turned into a jump to
4021 // the next instruction unless a PLT entry will be created.
4022 // The jump to the next instruction is optimized as a NOP.W for
4023 // Thumb-2 enabled architectures.
4024 const Target_arm<big_endian>* arm_target =
4025 Target_arm<big_endian>::default_target();
4026 if (is_weakly_undefined_without_plt)
4027 {
4028 gold_assert(!parameters->options().relocatable());
4029 if (arm_target->may_use_thumb2_nop())
4030 {
4031 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4032 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4033 }
4034 else
4035 {
4036 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4037 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4038 }
4039 return This::STATUS_OKAY;
4040 }
4041
4042 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4043 Arm_address branch_target = psymval->value(object, addend);
4044
4045 // For BLX, bit 1 of target address comes from bit 1 of base address.
4046 bool may_use_blx = arm_target->may_use_v5t_interworking();
4047 if (thumb_bit == 0 && may_use_blx)
4048 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4049
4050 int32_t branch_offset = branch_target - address;
4051
4052 // We need a stub if the branch offset is too large or if we need
4053 // to switch mode.
4054 bool thumb2 = arm_target->using_thumb2();
4055 if (!parameters->options().relocatable()
4056 && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4057 || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4058 || ((thumb_bit == 0)
4059 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4060 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4061 {
4062 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4063
4064 Stub_type stub_type =
4065 Reloc_stub::stub_type_for_reloc(r_type, address,
4066 unadjusted_branch_target,
4067 (thumb_bit != 0));
4068
4069 if (stub_type != arm_stub_none)
4070 {
4071 Stub_table<big_endian>* stub_table =
4072 object->stub_table(relinfo->data_shndx);
4073 gold_assert(stub_table != NULL);
4074
4075 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4076 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4077 gold_assert(stub != NULL);
4078 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4079 branch_target = stub_table->address() + stub->offset() + addend;
4080 if (thumb_bit == 0 && may_use_blx)
4081 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4082 branch_offset = branch_target - address;
4083 }
4084 }
4085
4086 // At this point, if we still need to switch mode, the instruction
4087 // must either be a BLX or a BL that can be converted to a BLX.
4088 if (thumb_bit == 0)
4089 {
4090 gold_assert(may_use_blx
4091 && (r_type == elfcpp::R_ARM_THM_CALL
4092 || r_type == elfcpp::R_ARM_THM_XPC22));
4093 // Make sure this is a BLX.
4094 lower_insn &= ~0x1000U;
4095 }
4096 else
4097 {
4098 // Make sure this is a BL.
4099 lower_insn |= 0x1000U;
4100 }
4101
4102 // For a BLX instruction, make sure that the relocation is rounded up
4103 // to a word boundary. This follows the semantics of the instruction
4104 // which specifies that bit 1 of the target address will come from bit
4105 // 1 of the base address.
4106 if ((lower_insn & 0x5000U) == 0x4000U)
4107 gold_assert((branch_offset & 3) == 0);
4108
4109 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4110 // We use the Thumb-2 encoding, which is safe even if dealing with
4111 // a Thumb-1 instruction by virtue of our overflow check above. */
4112 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4113 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4114
4115 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4116 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4117
4118 gold_assert(!Bits<25>::has_overflow32(branch_offset));
4119
4120 return ((thumb2
4121 ? Bits<25>::has_overflow32(branch_offset)
4122 : Bits<23>::has_overflow32(branch_offset))
4123 ? This::STATUS_OVERFLOW
4124 : This::STATUS_OKAY);
4125 }
4126
4127 // Relocate THUMB-2 long conditional branches.
4128 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4129 // undefined and we do not use PLT in this relocation. In such a case,
4130 // the branch is converted into an NOP.
4131
4132 template<bool big_endian>
4133 typename Arm_relocate_functions<big_endian>::Status
4134 Arm_relocate_functions<big_endian>::thm_jump19(
4135 unsigned char* view,
4136 const Arm_relobj<big_endian>* object,
4137 const Symbol_value<32>* psymval,
4138 Arm_address address,
4139 Arm_address thumb_bit)
4140 {
4141 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4142 Valtype* wv = reinterpret_cast<Valtype*>(view);
4143 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4144 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4145 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4146
4147 Arm_address branch_target = psymval->value(object, addend);
4148 int32_t branch_offset = branch_target - address;
4149
4150 // ??? Should handle interworking? GCC might someday try to
4151 // use this for tail calls.
4152 // FIXME: We do support thumb entry to PLT yet.
4153 if (thumb_bit == 0)
4154 {
4155 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4156 return This::STATUS_BAD_RELOC;
4157 }
4158
4159 // Put RELOCATION back into the insn.
4160 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4161 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4162
4163 // Put the relocated value back in the object file:
4164 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4165 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4166
4167 return (Bits<21>::has_overflow32(branch_offset)
4168 ? This::STATUS_OVERFLOW
4169 : This::STATUS_OKAY);
4170 }
4171
4172 // Get the GOT section, creating it if necessary.
4173
4174 template<bool big_endian>
4175 Arm_output_data_got<big_endian>*
4176 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4177 {
4178 if (this->got_ == NULL)
4179 {
4180 gold_assert(symtab != NULL && layout != NULL);
4181
4182 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4183
4184 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4185 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4186 this->got_, ORDER_DATA, false);
4187
4188 // The old GNU linker creates a .got.plt section. We just
4189 // create another set of data in the .got section. Note that we
4190 // always create a PLT if we create a GOT, although the PLT
4191 // might be empty.
4192 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4193 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4194 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4195 this->got_plt_, ORDER_DATA, false);
4196
4197 // The first three entries are reserved.
4198 this->got_plt_->set_current_data_size(3 * 4);
4199
4200 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4201 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4202 Symbol_table::PREDEFINED,
4203 this->got_plt_,
4204 0, 0, elfcpp::STT_OBJECT,
4205 elfcpp::STB_LOCAL,
4206 elfcpp::STV_HIDDEN, 0,
4207 false, false);
4208 }
4209 return this->got_;
4210 }
4211
4212 // Get the dynamic reloc section, creating it if necessary.
4213
4214 template<bool big_endian>
4215 typename Target_arm<big_endian>::Reloc_section*
4216 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4217 {
4218 if (this->rel_dyn_ == NULL)
4219 {
4220 gold_assert(layout != NULL);
4221 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4222 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4223 elfcpp::SHF_ALLOC, this->rel_dyn_,
4224 ORDER_DYNAMIC_RELOCS, false);
4225 }
4226 return this->rel_dyn_;
4227 }
4228
4229 // Insn_template methods.
4230
4231 // Return byte size of an instruction template.
4232
4233 size_t
4234 Insn_template::size() const
4235 {
4236 switch (this->type())
4237 {
4238 case THUMB16_TYPE:
4239 case THUMB16_SPECIAL_TYPE:
4240 return 2;
4241 case ARM_TYPE:
4242 case THUMB32_TYPE:
4243 case DATA_TYPE:
4244 return 4;
4245 default:
4246 gold_unreachable();
4247 }
4248 }
4249
4250 // Return alignment of an instruction template.
4251
4252 unsigned
4253 Insn_template::alignment() const
4254 {
4255 switch (this->type())
4256 {
4257 case THUMB16_TYPE:
4258 case THUMB16_SPECIAL_TYPE:
4259 case THUMB32_TYPE:
4260 return 2;
4261 case ARM_TYPE:
4262 case DATA_TYPE:
4263 return 4;
4264 default:
4265 gold_unreachable();
4266 }
4267 }
4268
4269 // Stub_template methods.
4270
4271 Stub_template::Stub_template(
4272 Stub_type type, const Insn_template* insns,
4273 size_t insn_count)
4274 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4275 entry_in_thumb_mode_(false), relocs_()
4276 {
4277 off_t offset = 0;
4278
4279 // Compute byte size and alignment of stub template.
4280 for (size_t i = 0; i < insn_count; i++)
4281 {
4282 unsigned insn_alignment = insns[i].alignment();
4283 size_t insn_size = insns[i].size();
4284 gold_assert((offset & (insn_alignment - 1)) == 0);
4285 this->alignment_ = std::max(this->alignment_, insn_alignment);
4286 switch (insns[i].type())
4287 {
4288 case Insn_template::THUMB16_TYPE:
4289 case Insn_template::THUMB16_SPECIAL_TYPE:
4290 if (i == 0)
4291 this->entry_in_thumb_mode_ = true;
4292 break;
4293
4294 case Insn_template::THUMB32_TYPE:
4295 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4296 this->relocs_.push_back(Reloc(i, offset));
4297 if (i == 0)
4298 this->entry_in_thumb_mode_ = true;
4299 break;
4300
4301 case Insn_template::ARM_TYPE:
4302 // Handle cases where the target is encoded within the
4303 // instruction.
4304 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4305 this->relocs_.push_back(Reloc(i, offset));
4306 break;
4307
4308 case Insn_template::DATA_TYPE:
4309 // Entry point cannot be data.
4310 gold_assert(i != 0);
4311 this->relocs_.push_back(Reloc(i, offset));
4312 break;
4313
4314 default:
4315 gold_unreachable();
4316 }
4317 offset += insn_size;
4318 }
4319 this->size_ = offset;
4320 }
4321
4322 // Stub methods.
4323
4324 // Template to implement do_write for a specific target endianness.
4325
4326 template<bool big_endian>
4327 void inline
4328 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4329 {
4330 const Stub_template* stub_template = this->stub_template();
4331 const Insn_template* insns = stub_template->insns();
4332
4333 // FIXME: We do not handle BE8 encoding yet.
4334 unsigned char* pov = view;
4335 for (size_t i = 0; i < stub_template->insn_count(); i++)
4336 {
4337 switch (insns[i].type())
4338 {
4339 case Insn_template::THUMB16_TYPE:
4340 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4341 break;
4342 case Insn_template::THUMB16_SPECIAL_TYPE:
4343 elfcpp::Swap<16, big_endian>::writeval(
4344 pov,
4345 this->thumb16_special(i));
4346 break;
4347 case Insn_template::THUMB32_TYPE:
4348 {
4349 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4350 uint32_t lo = insns[i].data() & 0xffff;
4351 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4352 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4353 }
4354 break;
4355 case Insn_template::ARM_TYPE:
4356 case Insn_template::DATA_TYPE:
4357 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4358 break;
4359 default:
4360 gold_unreachable();
4361 }
4362 pov += insns[i].size();
4363 }
4364 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4365 }
4366
4367 // Reloc_stub::Key methods.
4368
4369 // Dump a Key as a string for debugging.
4370
4371 std::string
4372 Reloc_stub::Key::name() const
4373 {
4374 if (this->r_sym_ == invalid_index)
4375 {
4376 // Global symbol key name
4377 // <stub-type>:<symbol name>:<addend>.
4378 const std::string sym_name = this->u_.symbol->name();
4379 // We need to print two hex number and two colons. So just add 100 bytes
4380 // to the symbol name size.
4381 size_t len = sym_name.size() + 100;
4382 char* buffer = new char[len];
4383 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4384 sym_name.c_str(), this->addend_);
4385 gold_assert(c > 0 && c < static_cast<int>(len));
4386 delete[] buffer;
4387 return std::string(buffer);
4388 }
4389 else
4390 {
4391 // local symbol key name
4392 // <stub-type>:<object>:<r_sym>:<addend>.
4393 const size_t len = 200;
4394 char buffer[len];
4395 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4396 this->u_.relobj, this->r_sym_, this->addend_);
4397 gold_assert(c > 0 && c < static_cast<int>(len));
4398 return std::string(buffer);
4399 }
4400 }
4401
4402 // Reloc_stub methods.
4403
4404 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4405 // LOCATION to DESTINATION.
4406 // This code is based on the arm_type_of_stub function in
4407 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4408 // class simple.
4409
4410 Stub_type
4411 Reloc_stub::stub_type_for_reloc(
4412 unsigned int r_type,
4413 Arm_address location,
4414 Arm_address destination,
4415 bool target_is_thumb)
4416 {
4417 Stub_type stub_type = arm_stub_none;
4418
4419 // This is a bit ugly but we want to avoid using a templated class for
4420 // big and little endianities.
4421 bool may_use_blx;
4422 bool should_force_pic_veneer;
4423 bool thumb2;
4424 bool thumb_only;
4425 if (parameters->target().is_big_endian())
4426 {
4427 const Target_arm<true>* big_endian_target =
4428 Target_arm<true>::default_target();
4429 may_use_blx = big_endian_target->may_use_v5t_interworking();
4430 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4431 thumb2 = big_endian_target->using_thumb2();
4432 thumb_only = big_endian_target->using_thumb_only();
4433 }
4434 else
4435 {
4436 const Target_arm<false>* little_endian_target =
4437 Target_arm<false>::default_target();
4438 may_use_blx = little_endian_target->may_use_v5t_interworking();
4439 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4440 thumb2 = little_endian_target->using_thumb2();
4441 thumb_only = little_endian_target->using_thumb_only();
4442 }
4443
4444 int64_t branch_offset;
4445 bool output_is_position_independent =
4446 parameters->options().output_is_position_independent();
4447 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4448 {
4449 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4450 // base address (instruction address + 4).
4451 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4452 destination = Bits<32>::bit_select32(destination, location, 0x2);
4453 branch_offset = static_cast<int64_t>(destination) - location;
4454
4455 // Handle cases where:
4456 // - this call goes too far (different Thumb/Thumb2 max
4457 // distance)
4458 // - it's a Thumb->Arm call and blx is not available, or it's a
4459 // Thumb->Arm branch (not bl). A stub is needed in this case.
4460 if ((!thumb2
4461 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4462 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4463 || (thumb2
4464 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4465 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4466 || ((!target_is_thumb)
4467 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4468 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4469 {
4470 if (target_is_thumb)
4471 {
4472 // Thumb to thumb.
4473 if (!thumb_only)
4474 {
4475 stub_type = (output_is_position_independent
4476 || should_force_pic_veneer)
4477 // PIC stubs.
4478 ? ((may_use_blx
4479 && (r_type == elfcpp::R_ARM_THM_CALL))
4480 // V5T and above. Stub starts with ARM code, so
4481 // we must be able to switch mode before
4482 // reaching it, which is only possible for 'bl'
4483 // (ie R_ARM_THM_CALL relocation).
4484 ? arm_stub_long_branch_any_thumb_pic
4485 // On V4T, use Thumb code only.
4486 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4487
4488 // non-PIC stubs.
4489 : ((may_use_blx
4490 && (r_type == elfcpp::R_ARM_THM_CALL))
4491 ? arm_stub_long_branch_any_any // V5T and above.
4492 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4493 }
4494 else
4495 {
4496 stub_type = (output_is_position_independent
4497 || should_force_pic_veneer)
4498 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4499 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4500 }
4501 }
4502 else
4503 {
4504 // Thumb to arm.
4505
4506 // FIXME: We should check that the input section is from an
4507 // object that has interwork enabled.
4508
4509 stub_type = (output_is_position_independent
4510 || should_force_pic_veneer)
4511 // PIC stubs.
4512 ? ((may_use_blx
4513 && (r_type == elfcpp::R_ARM_THM_CALL))
4514 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4515 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4516
4517 // non-PIC stubs.
4518 : ((may_use_blx
4519 && (r_type == elfcpp::R_ARM_THM_CALL))
4520 ? arm_stub_long_branch_any_any // V5T and above.
4521 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4522
4523 // Handle v4t short branches.
4524 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4525 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4526 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4527 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4528 }
4529 }
4530 }
4531 else if (r_type == elfcpp::R_ARM_CALL
4532 || r_type == elfcpp::R_ARM_JUMP24
4533 || r_type == elfcpp::R_ARM_PLT32)
4534 {
4535 branch_offset = static_cast<int64_t>(destination) - location;
4536 if (target_is_thumb)
4537 {
4538 // Arm to thumb.
4539
4540 // FIXME: We should check that the input section is from an
4541 // object that has interwork enabled.
4542
4543 // We have an extra 2-bytes reach because of
4544 // the mode change (bit 24 (H) of BLX encoding).
4545 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4546 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4547 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4548 || (r_type == elfcpp::R_ARM_JUMP24)
4549 || (r_type == elfcpp::R_ARM_PLT32))
4550 {
4551 stub_type = (output_is_position_independent
4552 || should_force_pic_veneer)
4553 // PIC stubs.
4554 ? (may_use_blx
4555 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4556 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4557
4558 // non-PIC stubs.
4559 : (may_use_blx
4560 ? arm_stub_long_branch_any_any // V5T and above.
4561 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4562 }
4563 }
4564 else
4565 {
4566 // Arm to arm.
4567 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4568 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4569 {
4570 stub_type = (output_is_position_independent
4571 || should_force_pic_veneer)
4572 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4573 : arm_stub_long_branch_any_any; /// non-PIC.
4574 }
4575 }
4576 }
4577
4578 return stub_type;
4579 }
4580
4581 // Cortex_a8_stub methods.
4582
4583 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4584 // I is the position of the instruction template in the stub template.
4585
4586 uint16_t
4587 Cortex_a8_stub::do_thumb16_special(size_t i)
4588 {
4589 // The only use of this is to copy condition code from a conditional
4590 // branch being worked around to the corresponding conditional branch in
4591 // to the stub.
4592 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4593 && i == 0);
4594 uint16_t data = this->stub_template()->insns()[i].data();
4595 gold_assert((data & 0xff00U) == 0xd000U);
4596 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4597 return data;
4598 }
4599
4600 // Stub_factory methods.
4601
4602 Stub_factory::Stub_factory()
4603 {
4604 // The instruction template sequences are declared as static
4605 // objects and initialized first time the constructor runs.
4606
4607 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4608 // to reach the stub if necessary.
4609 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4610 {
4611 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4612 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4613 // dcd R_ARM_ABS32(X)
4614 };
4615
4616 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4617 // available.
4618 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4619 {
4620 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4621 Insn_template::arm_insn(0xe12fff1c), // bx ip
4622 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4623 // dcd R_ARM_ABS32(X)
4624 };
4625
4626 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4627 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4628 {
4629 Insn_template::thumb16_insn(0xb401), // push {r0}
4630 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4631 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4632 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4633 Insn_template::thumb16_insn(0x4760), // bx ip
4634 Insn_template::thumb16_insn(0xbf00), // nop
4635 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4636 // dcd R_ARM_ABS32(X)
4637 };
4638
4639 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4640 // allowed.
4641 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4642 {
4643 Insn_template::thumb16_insn(0x4778), // bx pc
4644 Insn_template::thumb16_insn(0x46c0), // nop
4645 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4646 Insn_template::arm_insn(0xe12fff1c), // bx ip
4647 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4648 // dcd R_ARM_ABS32(X)
4649 };
4650
4651 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4652 // available.
4653 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4654 {
4655 Insn_template::thumb16_insn(0x4778), // bx pc
4656 Insn_template::thumb16_insn(0x46c0), // nop
4657 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4658 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4659 // dcd R_ARM_ABS32(X)
4660 };
4661
4662 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4663 // one, when the destination is close enough.
4664 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4665 {
4666 Insn_template::thumb16_insn(0x4778), // bx pc
4667 Insn_template::thumb16_insn(0x46c0), // nop
4668 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4669 };
4670
4671 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4672 // blx to reach the stub if necessary.
4673 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4674 {
4675 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4676 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4677 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4678 // dcd R_ARM_REL32(X-4)
4679 };
4680
4681 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4682 // blx to reach the stub if necessary. We can not add into pc;
4683 // it is not guaranteed to mode switch (different in ARMv6 and
4684 // ARMv7).
4685 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4686 {
4687 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4688 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4689 Insn_template::arm_insn(0xe12fff1c), // bx ip
4690 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4691 // dcd R_ARM_REL32(X)
4692 };
4693
4694 // V4T ARM -> ARM long branch stub, PIC.
4695 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4696 {
4697 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4698 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4699 Insn_template::arm_insn(0xe12fff1c), // bx ip
4700 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4701 // dcd R_ARM_REL32(X)
4702 };
4703
4704 // V4T Thumb -> ARM long branch stub, PIC.
4705 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4706 {
4707 Insn_template::thumb16_insn(0x4778), // bx pc
4708 Insn_template::thumb16_insn(0x46c0), // nop
4709 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4710 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4711 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4712 // dcd R_ARM_REL32(X)
4713 };
4714
4715 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4716 // architectures.
4717 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4718 {
4719 Insn_template::thumb16_insn(0xb401), // push {r0}
4720 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4721 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4722 Insn_template::thumb16_insn(0x4484), // add ip, r0
4723 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4724 Insn_template::thumb16_insn(0x4760), // bx ip
4725 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4726 // dcd R_ARM_REL32(X)
4727 };
4728
4729 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4730 // allowed.
4731 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4732 {
4733 Insn_template::thumb16_insn(0x4778), // bx pc
4734 Insn_template::thumb16_insn(0x46c0), // nop
4735 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4736 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4737 Insn_template::arm_insn(0xe12fff1c), // bx ip
4738 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4739 // dcd R_ARM_REL32(X)
4740 };
4741
4742 // Cortex-A8 erratum-workaround stubs.
4743
4744 // Stub used for conditional branches (which may be beyond +/-1MB away,
4745 // so we can't use a conditional branch to reach this stub).
4746
4747 // original code:
4748 //
4749 // b<cond> X
4750 // after:
4751 //
4752 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4753 {
4754 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4755 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4756 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4757 // b.w X
4758 };
4759
4760 // Stub used for b.w and bl.w instructions.
4761
4762 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4763 {
4764 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4765 };
4766
4767 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4768 {
4769 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4770 };
4771
4772 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4773 // instruction (which switches to ARM mode) to point to this stub. Jump to
4774 // the real destination using an ARM-mode branch.
4775 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4776 {
4777 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4778 };
4779
4780 // Stub used to provide an interworking for R_ARM_V4BX relocation
4781 // (bx r[n] instruction).
4782 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4783 {
4784 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4785 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4786 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4787 };
4788
4789 // Fill in the stub template look-up table. Stub templates are constructed
4790 // per instance of Stub_factory for fast look-up without locking
4791 // in a thread-enabled environment.
4792
4793 this->stub_templates_[arm_stub_none] =
4794 new Stub_template(arm_stub_none, NULL, 0);
4795
4796 #define DEF_STUB(x) \
4797 do \
4798 { \
4799 size_t array_size \
4800 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4801 Stub_type type = arm_stub_##x; \
4802 this->stub_templates_[type] = \
4803 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4804 } \
4805 while (0);
4806
4807 DEF_STUBS
4808 #undef DEF_STUB
4809 }
4810
4811 // Stub_table methods.
4812
4813 // Remove all Cortex-A8 stub.
4814
4815 template<bool big_endian>
4816 void
4817 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4818 {
4819 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4820 p != this->cortex_a8_stubs_.end();
4821 ++p)
4822 delete p->second;
4823 this->cortex_a8_stubs_.clear();
4824 }
4825
4826 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4827
4828 template<bool big_endian>
4829 void
4830 Stub_table<big_endian>::relocate_stub(
4831 Stub* stub,
4832 const Relocate_info<32, big_endian>* relinfo,
4833 Target_arm<big_endian>* arm_target,
4834 Output_section* output_section,
4835 unsigned char* view,
4836 Arm_address address,
4837 section_size_type view_size)
4838 {
4839 const Stub_template* stub_template = stub->stub_template();
4840 if (stub_template->reloc_count() != 0)
4841 {
4842 // Adjust view to cover the stub only.
4843 section_size_type offset = stub->offset();
4844 section_size_type stub_size = stub_template->size();
4845 gold_assert(offset + stub_size <= view_size);
4846
4847 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4848 address + offset, stub_size);
4849 }
4850 }
4851
4852 // Relocate all stubs in this stub table.
4853
4854 template<bool big_endian>
4855 void
4856 Stub_table<big_endian>::relocate_stubs(
4857 const Relocate_info<32, big_endian>* relinfo,
4858 Target_arm<big_endian>* arm_target,
4859 Output_section* output_section,
4860 unsigned char* view,
4861 Arm_address address,
4862 section_size_type view_size)
4863 {
4864 // If we are passed a view bigger than the stub table's. we need to
4865 // adjust the view.
4866 gold_assert(address == this->address()
4867 && (view_size
4868 == static_cast<section_size_type>(this->data_size())));
4869
4870 // Relocate all relocation stubs.
4871 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4872 p != this->reloc_stubs_.end();
4873 ++p)
4874 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4875 address, view_size);
4876
4877 // Relocate all Cortex-A8 stubs.
4878 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4879 p != this->cortex_a8_stubs_.end();
4880 ++p)
4881 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4882 address, view_size);
4883
4884 // Relocate all ARM V4BX stubs.
4885 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4886 p != this->arm_v4bx_stubs_.end();
4887 ++p)
4888 {
4889 if (*p != NULL)
4890 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4891 address, view_size);
4892 }
4893 }
4894
4895 // Write out the stubs to file.
4896
4897 template<bool big_endian>
4898 void
4899 Stub_table<big_endian>::do_write(Output_file* of)
4900 {
4901 off_t offset = this->offset();
4902 const section_size_type oview_size =
4903 convert_to_section_size_type(this->data_size());
4904 unsigned char* const oview = of->get_output_view(offset, oview_size);
4905
4906 // Write relocation stubs.
4907 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4908 p != this->reloc_stubs_.end();
4909 ++p)
4910 {
4911 Reloc_stub* stub = p->second;
4912 Arm_address address = this->address() + stub->offset();
4913 gold_assert(address
4914 == align_address(address,
4915 stub->stub_template()->alignment()));
4916 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4917 big_endian);
4918 }
4919
4920 // Write Cortex-A8 stubs.
4921 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4922 p != this->cortex_a8_stubs_.end();
4923 ++p)
4924 {
4925 Cortex_a8_stub* stub = p->second;
4926 Arm_address address = this->address() + stub->offset();
4927 gold_assert(address
4928 == align_address(address,
4929 stub->stub_template()->alignment()));
4930 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4931 big_endian);
4932 }
4933
4934 // Write ARM V4BX relocation stubs.
4935 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4936 p != this->arm_v4bx_stubs_.end();
4937 ++p)
4938 {
4939 if (*p == NULL)
4940 continue;
4941
4942 Arm_address address = this->address() + (*p)->offset();
4943 gold_assert(address
4944 == align_address(address,
4945 (*p)->stub_template()->alignment()));
4946 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4947 big_endian);
4948 }
4949
4950 of->write_output_view(this->offset(), oview_size, oview);
4951 }
4952
4953 // Update the data size and address alignment of the stub table at the end
4954 // of a relaxation pass. Return true if either the data size or the
4955 // alignment changed in this relaxation pass.
4956
4957 template<bool big_endian>
4958 bool
4959 Stub_table<big_endian>::update_data_size_and_addralign()
4960 {
4961 // Go over all stubs in table to compute data size and address alignment.
4962 off_t size = this->reloc_stubs_size_;
4963 unsigned addralign = this->reloc_stubs_addralign_;
4964
4965 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4966 p != this->cortex_a8_stubs_.end();
4967 ++p)
4968 {
4969 const Stub_template* stub_template = p->second->stub_template();
4970 addralign = std::max(addralign, stub_template->alignment());
4971 size = (align_address(size, stub_template->alignment())
4972 + stub_template->size());
4973 }
4974
4975 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4976 p != this->arm_v4bx_stubs_.end();
4977 ++p)
4978 {
4979 if (*p == NULL)
4980 continue;
4981
4982 const Stub_template* stub_template = (*p)->stub_template();
4983 addralign = std::max(addralign, stub_template->alignment());
4984 size = (align_address(size, stub_template->alignment())
4985 + stub_template->size());
4986 }
4987
4988 // Check if either data size or alignment changed in this pass.
4989 // Update prev_data_size_ and prev_addralign_. These will be used
4990 // as the current data size and address alignment for the next pass.
4991 bool changed = size != this->prev_data_size_;
4992 this->prev_data_size_ = size;
4993
4994 if (addralign != this->prev_addralign_)
4995 changed = true;
4996 this->prev_addralign_ = addralign;
4997
4998 return changed;
4999 }
5000
5001 // Finalize the stubs. This sets the offsets of the stubs within the stub
5002 // table. It also marks all input sections needing Cortex-A8 workaround.
5003
5004 template<bool big_endian>
5005 void
5006 Stub_table<big_endian>::finalize_stubs()
5007 {
5008 off_t off = this->reloc_stubs_size_;
5009 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5010 p != this->cortex_a8_stubs_.end();
5011 ++p)
5012 {
5013 Cortex_a8_stub* stub = p->second;
5014 const Stub_template* stub_template = stub->stub_template();
5015 uint64_t stub_addralign = stub_template->alignment();
5016 off = align_address(off, stub_addralign);
5017 stub->set_offset(off);
5018 off += stub_template->size();
5019
5020 // Mark input section so that we can determine later if a code section
5021 // needs the Cortex-A8 workaround quickly.
5022 Arm_relobj<big_endian>* arm_relobj =
5023 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5024 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5025 }
5026
5027 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5028 p != this->arm_v4bx_stubs_.end();
5029 ++p)
5030 {
5031 if (*p == NULL)
5032 continue;
5033
5034 const Stub_template* stub_template = (*p)->stub_template();
5035 uint64_t stub_addralign = stub_template->alignment();
5036 off = align_address(off, stub_addralign);
5037 (*p)->set_offset(off);
5038 off += stub_template->size();
5039 }
5040
5041 gold_assert(off <= this->prev_data_size_);
5042 }
5043
5044 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5045 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5046 // of the address range seen by the linker.
5047
5048 template<bool big_endian>
5049 void
5050 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5051 Target_arm<big_endian>* arm_target,
5052 unsigned char* view,
5053 Arm_address view_address,
5054 section_size_type view_size)
5055 {
5056 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5057 for (Cortex_a8_stub_list::const_iterator p =
5058 this->cortex_a8_stubs_.lower_bound(view_address);
5059 ((p != this->cortex_a8_stubs_.end())
5060 && (p->first < (view_address + view_size)));
5061 ++p)
5062 {
5063 // We do not store the THUMB bit in the LSB of either the branch address
5064 // or the stub offset. There is no need to strip the LSB.
5065 Arm_address branch_address = p->first;
5066 const Cortex_a8_stub* stub = p->second;
5067 Arm_address stub_address = this->address() + stub->offset();
5068
5069 // Offset of the branch instruction relative to this view.
5070 section_size_type offset =
5071 convert_to_section_size_type(branch_address - view_address);
5072 gold_assert((offset + 4) <= view_size);
5073
5074 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5075 view + offset, branch_address);
5076 }
5077 }
5078
5079 // Arm_input_section methods.
5080
5081 // Initialize an Arm_input_section.
5082
5083 template<bool big_endian>
5084 void
5085 Arm_input_section<big_endian>::init()
5086 {
5087 Relobj* relobj = this->relobj();
5088 unsigned int shndx = this->shndx();
5089
5090 // We have to cache original size, alignment and contents to avoid locking
5091 // the original file.
5092 this->original_addralign_ =
5093 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5094
5095 // This is not efficient but we expect only a small number of relaxed
5096 // input sections for stubs.
5097 section_size_type section_size;
5098 const unsigned char* section_contents =
5099 relobj->section_contents(shndx, &section_size, false);
5100 this->original_size_ =
5101 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5102
5103 gold_assert(this->original_contents_ == NULL);
5104 this->original_contents_ = new unsigned char[section_size];
5105 memcpy(this->original_contents_, section_contents, section_size);
5106
5107 // We want to make this look like the original input section after
5108 // output sections are finalized.
5109 Output_section* os = relobj->output_section(shndx);
5110 off_t offset = relobj->output_section_offset(shndx);
5111 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5112 this->set_address(os->address() + offset);
5113 this->set_file_offset(os->offset() + offset);
5114
5115 this->set_current_data_size(this->original_size_);
5116 this->finalize_data_size();
5117 }
5118
5119 template<bool big_endian>
5120 void
5121 Arm_input_section<big_endian>::do_write(Output_file* of)
5122 {
5123 // We have to write out the original section content.
5124 gold_assert(this->original_contents_ != NULL);
5125 of->write(this->offset(), this->original_contents_,
5126 this->original_size_);
5127
5128 // If this owns a stub table and it is not empty, write it.
5129 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5130 this->stub_table_->write(of);
5131 }
5132
5133 // Finalize data size.
5134
5135 template<bool big_endian>
5136 void
5137 Arm_input_section<big_endian>::set_final_data_size()
5138 {
5139 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5140
5141 if (this->is_stub_table_owner())
5142 {
5143 this->stub_table_->finalize_data_size();
5144 off = align_address(off, this->stub_table_->addralign());
5145 off += this->stub_table_->data_size();
5146 }
5147 this->set_data_size(off);
5148 }
5149
5150 // Reset address and file offset.
5151
5152 template<bool big_endian>
5153 void
5154 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5155 {
5156 // Size of the original input section contents.
5157 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5158
5159 // If this is a stub table owner, account for the stub table size.
5160 if (this->is_stub_table_owner())
5161 {
5162 Stub_table<big_endian>* stub_table = this->stub_table_;
5163
5164 // Reset the stub table's address and file offset. The
5165 // current data size for child will be updated after that.
5166 stub_table_->reset_address_and_file_offset();
5167 off = align_address(off, stub_table_->addralign());
5168 off += stub_table->current_data_size();
5169 }
5170
5171 this->set_current_data_size(off);
5172 }
5173
5174 // Arm_exidx_cantunwind methods.
5175
5176 // Write this to Output file OF for a fixed endianness.
5177
5178 template<bool big_endian>
5179 void
5180 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5181 {
5182 off_t offset = this->offset();
5183 const section_size_type oview_size = 8;
5184 unsigned char* const oview = of->get_output_view(offset, oview_size);
5185
5186 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
5187
5188 Output_section* os = this->relobj_->output_section(this->shndx_);
5189 gold_assert(os != NULL);
5190
5191 Arm_relobj<big_endian>* arm_relobj =
5192 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5193 Arm_address output_offset =
5194 arm_relobj->get_output_section_offset(this->shndx_);
5195 Arm_address section_start;
5196 section_size_type section_size;
5197
5198 // Find out the end of the text section referred by this.
5199 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5200 {
5201 section_start = os->address() + output_offset;
5202 const Arm_exidx_input_section* exidx_input_section =
5203 arm_relobj->exidx_input_section_by_link(this->shndx_);
5204 gold_assert(exidx_input_section != NULL);
5205 section_size =
5206 convert_to_section_size_type(exidx_input_section->text_size());
5207 }
5208 else
5209 {
5210 // Currently this only happens for a relaxed section.
5211 const Output_relaxed_input_section* poris =
5212 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5213 gold_assert(poris != NULL);
5214 section_start = poris->address();
5215 section_size = convert_to_section_size_type(poris->data_size());
5216 }
5217
5218 // We always append this to the end of an EXIDX section.
5219 Arm_address output_address = section_start + section_size;
5220
5221 // Write out the entry. The first word either points to the beginning
5222 // or after the end of a text section. The second word is the special
5223 // EXIDX_CANTUNWIND value.
5224 uint32_t prel31_offset = output_address - this->address();
5225 if (Bits<31>::has_overflow32(offset))
5226 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5227 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5228 prel31_offset & 0x7fffffffU);
5229 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5230 elfcpp::EXIDX_CANTUNWIND);
5231
5232 of->write_output_view(this->offset(), oview_size, oview);
5233 }
5234
5235 // Arm_exidx_merged_section methods.
5236
5237 // Constructor for Arm_exidx_merged_section.
5238 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5239 // SECTION_OFFSET_MAP points to a section offset map describing how
5240 // parts of the input section are mapped to output. DELETED_BYTES is
5241 // the number of bytes deleted from the EXIDX input section.
5242
5243 Arm_exidx_merged_section::Arm_exidx_merged_section(
5244 const Arm_exidx_input_section& exidx_input_section,
5245 const Arm_exidx_section_offset_map& section_offset_map,
5246 uint32_t deleted_bytes)
5247 : Output_relaxed_input_section(exidx_input_section.relobj(),
5248 exidx_input_section.shndx(),
5249 exidx_input_section.addralign()),
5250 exidx_input_section_(exidx_input_section),
5251 section_offset_map_(section_offset_map)
5252 {
5253 // If we retain or discard the whole EXIDX input section, we would
5254 // not be here.
5255 gold_assert(deleted_bytes != 0
5256 && deleted_bytes != this->exidx_input_section_.size());
5257
5258 // Fix size here so that we do not need to implement set_final_data_size.
5259 uint32_t size = exidx_input_section.size() - deleted_bytes;
5260 this->set_data_size(size);
5261 this->fix_data_size();
5262
5263 // Allocate buffer for section contents and build contents.
5264 this->section_contents_ = new unsigned char[size];
5265 }
5266
5267 // Build the contents of a merged EXIDX output section.
5268
5269 void
5270 Arm_exidx_merged_section::build_contents(
5271 const unsigned char* original_contents,
5272 section_size_type original_size)
5273 {
5274 // Go over spans of input offsets and write only those that are not
5275 // discarded.
5276 section_offset_type in_start = 0;
5277 section_offset_type out_start = 0;
5278 section_offset_type in_max =
5279 convert_types<section_offset_type>(original_size);
5280 section_offset_type out_max =
5281 convert_types<section_offset_type>(this->data_size());
5282 for (Arm_exidx_section_offset_map::const_iterator p =
5283 this->section_offset_map_.begin();
5284 p != this->section_offset_map_.end();
5285 ++p)
5286 {
5287 section_offset_type in_end = p->first;
5288 gold_assert(in_end >= in_start);
5289 section_offset_type out_end = p->second;
5290 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5291 if (out_end != -1)
5292 {
5293 size_t out_chunk_size =
5294 convert_types<size_t>(out_end - out_start + 1);
5295
5296 gold_assert(out_chunk_size == in_chunk_size
5297 && in_end < in_max && out_end < out_max);
5298
5299 memcpy(this->section_contents_ + out_start,
5300 original_contents + in_start,
5301 out_chunk_size);
5302 out_start += out_chunk_size;
5303 }
5304 in_start += in_chunk_size;
5305 }
5306 }
5307
5308 // Given an input OBJECT, an input section index SHNDX within that
5309 // object, and an OFFSET relative to the start of that input
5310 // section, return whether or not the corresponding offset within
5311 // the output section is known. If this function returns true, it
5312 // sets *POUTPUT to the output offset. The value -1 indicates that
5313 // this input offset is being discarded.
5314
5315 bool
5316 Arm_exidx_merged_section::do_output_offset(
5317 const Relobj* relobj,
5318 unsigned int shndx,
5319 section_offset_type offset,
5320 section_offset_type* poutput) const
5321 {
5322 // We only handle offsets for the original EXIDX input section.
5323 if (relobj != this->exidx_input_section_.relobj()
5324 || shndx != this->exidx_input_section_.shndx())
5325 return false;
5326
5327 section_offset_type section_size =
5328 convert_types<section_offset_type>(this->exidx_input_section_.size());
5329 if (offset < 0 || offset >= section_size)
5330 // Input offset is out of valid range.
5331 *poutput = -1;
5332 else
5333 {
5334 // We need to look up the section offset map to determine the output
5335 // offset. Find the reference point in map that is first offset
5336 // bigger than or equal to this offset.
5337 Arm_exidx_section_offset_map::const_iterator p =
5338 this->section_offset_map_.lower_bound(offset);
5339
5340 // The section offset maps are build such that this should not happen if
5341 // input offset is in the valid range.
5342 gold_assert(p != this->section_offset_map_.end());
5343
5344 // We need to check if this is dropped.
5345 section_offset_type ref = p->first;
5346 section_offset_type mapped_ref = p->second;
5347
5348 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5349 // Offset is present in output.
5350 *poutput = mapped_ref + (offset - ref);
5351 else
5352 // Offset is discarded owing to EXIDX entry merging.
5353 *poutput = -1;
5354 }
5355
5356 return true;
5357 }
5358
5359 // Write this to output file OF.
5360
5361 void
5362 Arm_exidx_merged_section::do_write(Output_file* of)
5363 {
5364 off_t offset = this->offset();
5365 const section_size_type oview_size = this->data_size();
5366 unsigned char* const oview = of->get_output_view(offset, oview_size);
5367
5368 Output_section* os = this->relobj()->output_section(this->shndx());
5369 gold_assert(os != NULL);
5370
5371 memcpy(oview, this->section_contents_, oview_size);
5372 of->write_output_view(this->offset(), oview_size, oview);
5373 }
5374
5375 // Arm_exidx_fixup methods.
5376
5377 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5378 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5379 // points to the end of the last seen EXIDX section.
5380
5381 void
5382 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5383 {
5384 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5385 && this->last_input_section_ != NULL)
5386 {
5387 Relobj* relobj = this->last_input_section_->relobj();
5388 unsigned int text_shndx = this->last_input_section_->link();
5389 Arm_exidx_cantunwind* cantunwind =
5390 new Arm_exidx_cantunwind(relobj, text_shndx);
5391 this->exidx_output_section_->add_output_section_data(cantunwind);
5392 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5393 }
5394 }
5395
5396 // Process an EXIDX section entry in input. Return whether this entry
5397 // can be deleted in the output. SECOND_WORD in the second word of the
5398 // EXIDX entry.
5399
5400 bool
5401 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5402 {
5403 bool delete_entry;
5404 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5405 {
5406 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5407 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5408 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5409 }
5410 else if ((second_word & 0x80000000) != 0)
5411 {
5412 // Inlined unwinding data. Merge if equal to previous.
5413 delete_entry = (merge_exidx_entries_
5414 && this->last_unwind_type_ == UT_INLINED_ENTRY
5415 && this->last_inlined_entry_ == second_word);
5416 this->last_unwind_type_ = UT_INLINED_ENTRY;
5417 this->last_inlined_entry_ = second_word;
5418 }
5419 else
5420 {
5421 // Normal table entry. In theory we could merge these too,
5422 // but duplicate entries are likely to be much less common.
5423 delete_entry = false;
5424 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5425 }
5426 return delete_entry;
5427 }
5428
5429 // Update the current section offset map during EXIDX section fix-up.
5430 // If there is no map, create one. INPUT_OFFSET is the offset of a
5431 // reference point, DELETED_BYTES is the number of deleted by in the
5432 // section so far. If DELETE_ENTRY is true, the reference point and
5433 // all offsets after the previous reference point are discarded.
5434
5435 void
5436 Arm_exidx_fixup::update_offset_map(
5437 section_offset_type input_offset,
5438 section_size_type deleted_bytes,
5439 bool delete_entry)
5440 {
5441 if (this->section_offset_map_ == NULL)
5442 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5443 section_offset_type output_offset;
5444 if (delete_entry)
5445 output_offset = Arm_exidx_input_section::invalid_offset;
5446 else
5447 output_offset = input_offset - deleted_bytes;
5448 (*this->section_offset_map_)[input_offset] = output_offset;
5449 }
5450
5451 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5452 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5453 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5454 // If some entries are merged, also store a pointer to a newly created
5455 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5456 // owns the map and is responsible for releasing it after use.
5457
5458 template<bool big_endian>
5459 uint32_t
5460 Arm_exidx_fixup::process_exidx_section(
5461 const Arm_exidx_input_section* exidx_input_section,
5462 const unsigned char* section_contents,
5463 section_size_type section_size,
5464 Arm_exidx_section_offset_map** psection_offset_map)
5465 {
5466 Relobj* relobj = exidx_input_section->relobj();
5467 unsigned shndx = exidx_input_section->shndx();
5468
5469 if ((section_size % 8) != 0)
5470 {
5471 // Something is wrong with this section. Better not touch it.
5472 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5473 relobj->name().c_str(), shndx);
5474 this->last_input_section_ = exidx_input_section;
5475 this->last_unwind_type_ = UT_NONE;
5476 return 0;
5477 }
5478
5479 uint32_t deleted_bytes = 0;
5480 bool prev_delete_entry = false;
5481 gold_assert(this->section_offset_map_ == NULL);
5482
5483 for (section_size_type i = 0; i < section_size; i += 8)
5484 {
5485 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5486 const Valtype* wv =
5487 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5488 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5489
5490 bool delete_entry = this->process_exidx_entry(second_word);
5491
5492 // Entry deletion causes changes in output offsets. We use a std::map
5493 // to record these. And entry (x, y) means input offset x
5494 // is mapped to output offset y. If y is invalid_offset, then x is
5495 // dropped in the output. Because of the way std::map::lower_bound
5496 // works, we record the last offset in a region w.r.t to keeping or
5497 // dropping. If there is no entry (x0, y0) for an input offset x0,
5498 // the output offset y0 of it is determined by the output offset y1 of
5499 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5500 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5501 // y0 is also -1.
5502 if (delete_entry != prev_delete_entry && i != 0)
5503 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5504
5505 // Update total deleted bytes for this entry.
5506 if (delete_entry)
5507 deleted_bytes += 8;
5508
5509 prev_delete_entry = delete_entry;
5510 }
5511
5512 // If section offset map is not NULL, make an entry for the end of
5513 // section.
5514 if (this->section_offset_map_ != NULL)
5515 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5516
5517 *psection_offset_map = this->section_offset_map_;
5518 this->section_offset_map_ = NULL;
5519 this->last_input_section_ = exidx_input_section;
5520
5521 // Set the first output text section so that we can link the EXIDX output
5522 // section to it. Ignore any EXIDX input section that is completely merged.
5523 if (this->first_output_text_section_ == NULL
5524 && deleted_bytes != section_size)
5525 {
5526 unsigned int link = exidx_input_section->link();
5527 Output_section* os = relobj->output_section(link);
5528 gold_assert(os != NULL);
5529 this->first_output_text_section_ = os;
5530 }
5531
5532 return deleted_bytes;
5533 }
5534
5535 // Arm_output_section methods.
5536
5537 // Create a stub group for input sections from BEGIN to END. OWNER
5538 // points to the input section to be the owner a new stub table.
5539
5540 template<bool big_endian>
5541 void
5542 Arm_output_section<big_endian>::create_stub_group(
5543 Input_section_list::const_iterator begin,
5544 Input_section_list::const_iterator end,
5545 Input_section_list::const_iterator owner,
5546 Target_arm<big_endian>* target,
5547 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5548 const Task* task)
5549 {
5550 // We use a different kind of relaxed section in an EXIDX section.
5551 // The static casting from Output_relaxed_input_section to
5552 // Arm_input_section is invalid in an EXIDX section. We are okay
5553 // because we should not be calling this for an EXIDX section.
5554 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5555
5556 // Currently we convert ordinary input sections into relaxed sections only
5557 // at this point but we may want to support creating relaxed input section
5558 // very early. So we check here to see if owner is already a relaxed
5559 // section.
5560
5561 Arm_input_section<big_endian>* arm_input_section;
5562 if (owner->is_relaxed_input_section())
5563 {
5564 arm_input_section =
5565 Arm_input_section<big_endian>::as_arm_input_section(
5566 owner->relaxed_input_section());
5567 }
5568 else
5569 {
5570 gold_assert(owner->is_input_section());
5571 // Create a new relaxed input section. We need to lock the original
5572 // file.
5573 Task_lock_obj<Object> tl(task, owner->relobj());
5574 arm_input_section =
5575 target->new_arm_input_section(owner->relobj(), owner->shndx());
5576 new_relaxed_sections->push_back(arm_input_section);
5577 }
5578
5579 // Create a stub table.
5580 Stub_table<big_endian>* stub_table =
5581 target->new_stub_table(arm_input_section);
5582
5583 arm_input_section->set_stub_table(stub_table);
5584
5585 Input_section_list::const_iterator p = begin;
5586 Input_section_list::const_iterator prev_p;
5587
5588 // Look for input sections or relaxed input sections in [begin ... end].
5589 do
5590 {
5591 if (p->is_input_section() || p->is_relaxed_input_section())
5592 {
5593 // The stub table information for input sections live
5594 // in their objects.
5595 Arm_relobj<big_endian>* arm_relobj =
5596 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5597 arm_relobj->set_stub_table(p->shndx(), stub_table);
5598 }
5599 prev_p = p++;
5600 }
5601 while (prev_p != end);
5602 }
5603
5604 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5605 // of stub groups. We grow a stub group by adding input section until the
5606 // size is just below GROUP_SIZE. The last input section will be converted
5607 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5608 // input section after the stub table, effectively double the group size.
5609 //
5610 // This is similar to the group_sections() function in elf32-arm.c but is
5611 // implemented differently.
5612
5613 template<bool big_endian>
5614 void
5615 Arm_output_section<big_endian>::group_sections(
5616 section_size_type group_size,
5617 bool stubs_always_after_branch,
5618 Target_arm<big_endian>* target,
5619 const Task* task)
5620 {
5621 // We only care about sections containing code.
5622 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5623 return;
5624
5625 // States for grouping.
5626 typedef enum
5627 {
5628 // No group is being built.
5629 NO_GROUP,
5630 // A group is being built but the stub table is not found yet.
5631 // We keep group a stub group until the size is just under GROUP_SIZE.
5632 // The last input section in the group will be used as the stub table.
5633 FINDING_STUB_SECTION,
5634 // A group is being built and we have already found a stub table.
5635 // We enter this state to grow a stub group by adding input section
5636 // after the stub table. This effectively doubles the group size.
5637 HAS_STUB_SECTION
5638 } State;
5639
5640 // Any newly created relaxed sections are stored here.
5641 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5642
5643 State state = NO_GROUP;
5644 section_size_type off = 0;
5645 section_size_type group_begin_offset = 0;
5646 section_size_type group_end_offset = 0;
5647 section_size_type stub_table_end_offset = 0;
5648 Input_section_list::const_iterator group_begin =
5649 this->input_sections().end();
5650 Input_section_list::const_iterator stub_table =
5651 this->input_sections().end();
5652 Input_section_list::const_iterator group_end = this->input_sections().end();
5653 for (Input_section_list::const_iterator p = this->input_sections().begin();
5654 p != this->input_sections().end();
5655 ++p)
5656 {
5657 section_size_type section_begin_offset =
5658 align_address(off, p->addralign());
5659 section_size_type section_end_offset =
5660 section_begin_offset + p->data_size();
5661
5662 // Check to see if we should group the previously seen sections.
5663 switch (state)
5664 {
5665 case NO_GROUP:
5666 break;
5667
5668 case FINDING_STUB_SECTION:
5669 // Adding this section makes the group larger than GROUP_SIZE.
5670 if (section_end_offset - group_begin_offset >= group_size)
5671 {
5672 if (stubs_always_after_branch)
5673 {
5674 gold_assert(group_end != this->input_sections().end());
5675 this->create_stub_group(group_begin, group_end, group_end,
5676 target, &new_relaxed_sections,
5677 task);
5678 state = NO_GROUP;
5679 }
5680 else
5681 {
5682 // But wait, there's more! Input sections up to
5683 // stub_group_size bytes after the stub table can be
5684 // handled by it too.
5685 state = HAS_STUB_SECTION;
5686 stub_table = group_end;
5687 stub_table_end_offset = group_end_offset;
5688 }
5689 }
5690 break;
5691
5692 case HAS_STUB_SECTION:
5693 // Adding this section makes the post stub-section group larger
5694 // than GROUP_SIZE.
5695 if (section_end_offset - stub_table_end_offset >= group_size)
5696 {
5697 gold_assert(group_end != this->input_sections().end());
5698 this->create_stub_group(group_begin, group_end, stub_table,
5699 target, &new_relaxed_sections, task);
5700 state = NO_GROUP;
5701 }
5702 break;
5703
5704 default:
5705 gold_unreachable();
5706 }
5707
5708 // If we see an input section and currently there is no group, start
5709 // a new one. Skip any empty sections. We look at the data size
5710 // instead of calling p->relobj()->section_size() to avoid locking.
5711 if ((p->is_input_section() || p->is_relaxed_input_section())
5712 && (p->data_size() != 0))
5713 {
5714 if (state == NO_GROUP)
5715 {
5716 state = FINDING_STUB_SECTION;
5717 group_begin = p;
5718 group_begin_offset = section_begin_offset;
5719 }
5720
5721 // Keep track of the last input section seen.
5722 group_end = p;
5723 group_end_offset = section_end_offset;
5724 }
5725
5726 off = section_end_offset;
5727 }
5728
5729 // Create a stub group for any ungrouped sections.
5730 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5731 {
5732 gold_assert(group_end != this->input_sections().end());
5733 this->create_stub_group(group_begin, group_end,
5734 (state == FINDING_STUB_SECTION
5735 ? group_end
5736 : stub_table),
5737 target, &new_relaxed_sections, task);
5738 }
5739
5740 // Convert input section into relaxed input section in a batch.
5741 if (!new_relaxed_sections.empty())
5742 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5743
5744 // Update the section offsets
5745 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5746 {
5747 Arm_relobj<big_endian>* arm_relobj =
5748 Arm_relobj<big_endian>::as_arm_relobj(
5749 new_relaxed_sections[i]->relobj());
5750 unsigned int shndx = new_relaxed_sections[i]->shndx();
5751 // Tell Arm_relobj that this input section is converted.
5752 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5753 }
5754 }
5755
5756 // Append non empty text sections in this to LIST in ascending
5757 // order of their position in this.
5758
5759 template<bool big_endian>
5760 void
5761 Arm_output_section<big_endian>::append_text_sections_to_list(
5762 Text_section_list* list)
5763 {
5764 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5765
5766 for (Input_section_list::const_iterator p = this->input_sections().begin();
5767 p != this->input_sections().end();
5768 ++p)
5769 {
5770 // We only care about plain or relaxed input sections. We also
5771 // ignore any merged sections.
5772 if (p->is_input_section() || p->is_relaxed_input_section())
5773 list->push_back(Text_section_list::value_type(p->relobj(),
5774 p->shndx()));
5775 }
5776 }
5777
5778 template<bool big_endian>
5779 void
5780 Arm_output_section<big_endian>::fix_exidx_coverage(
5781 Layout* layout,
5782 const Text_section_list& sorted_text_sections,
5783 Symbol_table* symtab,
5784 bool merge_exidx_entries,
5785 const Task* task)
5786 {
5787 // We should only do this for the EXIDX output section.
5788 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5789
5790 // We don't want the relaxation loop to undo these changes, so we discard
5791 // the current saved states and take another one after the fix-up.
5792 this->discard_states();
5793
5794 // Remove all input sections.
5795 uint64_t address = this->address();
5796 typedef std::list<Output_section::Input_section> Input_section_list;
5797 Input_section_list input_sections;
5798 this->reset_address_and_file_offset();
5799 this->get_input_sections(address, std::string(""), &input_sections);
5800
5801 if (!this->input_sections().empty())
5802 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5803
5804 // Go through all the known input sections and record them.
5805 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5806 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5807 Section_id_hash> Text_to_exidx_map;
5808 Text_to_exidx_map text_to_exidx_map;
5809 for (Input_section_list::const_iterator p = input_sections.begin();
5810 p != input_sections.end();
5811 ++p)
5812 {
5813 // This should never happen. At this point, we should only see
5814 // plain EXIDX input sections.
5815 gold_assert(!p->is_relaxed_input_section());
5816 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5817 }
5818
5819 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5820
5821 // Go over the sorted text sections.
5822 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5823 Section_id_set processed_input_sections;
5824 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5825 p != sorted_text_sections.end();
5826 ++p)
5827 {
5828 Relobj* relobj = p->first;
5829 unsigned int shndx = p->second;
5830
5831 Arm_relobj<big_endian>* arm_relobj =
5832 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5833 const Arm_exidx_input_section* exidx_input_section =
5834 arm_relobj->exidx_input_section_by_link(shndx);
5835
5836 // If this text section has no EXIDX section or if the EXIDX section
5837 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5838 // of the last seen EXIDX section.
5839 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5840 {
5841 exidx_fixup.add_exidx_cantunwind_as_needed();
5842 continue;
5843 }
5844
5845 Relobj* exidx_relobj = exidx_input_section->relobj();
5846 unsigned int exidx_shndx = exidx_input_section->shndx();
5847 Section_id sid(exidx_relobj, exidx_shndx);
5848 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5849 if (iter == text_to_exidx_map.end())
5850 {
5851 // This is odd. We have not seen this EXIDX input section before.
5852 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5853 // issue a warning instead. We assume the user knows what he
5854 // or she is doing. Otherwise, this is an error.
5855 if (layout->script_options()->saw_sections_clause())
5856 gold_warning(_("unwinding may not work because EXIDX input section"
5857 " %u of %s is not in EXIDX output section"),
5858 exidx_shndx, exidx_relobj->name().c_str());
5859 else
5860 gold_error(_("unwinding may not work because EXIDX input section"
5861 " %u of %s is not in EXIDX output section"),
5862 exidx_shndx, exidx_relobj->name().c_str());
5863
5864 exidx_fixup.add_exidx_cantunwind_as_needed();
5865 continue;
5866 }
5867
5868 // We need to access the contents of the EXIDX section, lock the
5869 // object here.
5870 Task_lock_obj<Object> tl(task, exidx_relobj);
5871 section_size_type exidx_size;
5872 const unsigned char* exidx_contents =
5873 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5874
5875 // Fix up coverage and append input section to output data list.
5876 Arm_exidx_section_offset_map* section_offset_map = NULL;
5877 uint32_t deleted_bytes =
5878 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5879 exidx_contents,
5880 exidx_size,
5881 &section_offset_map);
5882
5883 if (deleted_bytes == exidx_input_section->size())
5884 {
5885 // The whole EXIDX section got merged. Remove it from output.
5886 gold_assert(section_offset_map == NULL);
5887 exidx_relobj->set_output_section(exidx_shndx, NULL);
5888
5889 // All local symbols defined in this input section will be dropped.
5890 // We need to adjust output local symbol count.
5891 arm_relobj->set_output_local_symbol_count_needs_update();
5892 }
5893 else if (deleted_bytes > 0)
5894 {
5895 // Some entries are merged. We need to convert this EXIDX input
5896 // section into a relaxed section.
5897 gold_assert(section_offset_map != NULL);
5898
5899 Arm_exidx_merged_section* merged_section =
5900 new Arm_exidx_merged_section(*exidx_input_section,
5901 *section_offset_map, deleted_bytes);
5902 merged_section->build_contents(exidx_contents, exidx_size);
5903
5904 const std::string secname = exidx_relobj->section_name(exidx_shndx);
5905 this->add_relaxed_input_section(layout, merged_section, secname);
5906 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5907
5908 // All local symbols defined in discarded portions of this input
5909 // section will be dropped. We need to adjust output local symbol
5910 // count.
5911 arm_relobj->set_output_local_symbol_count_needs_update();
5912 }
5913 else
5914 {
5915 // Just add back the EXIDX input section.
5916 gold_assert(section_offset_map == NULL);
5917 const Output_section::Input_section* pis = iter->second;
5918 gold_assert(pis->is_input_section());
5919 this->add_script_input_section(*pis);
5920 }
5921
5922 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5923 }
5924
5925 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5926 exidx_fixup.add_exidx_cantunwind_as_needed();
5927
5928 // Remove any known EXIDX input sections that are not processed.
5929 for (Input_section_list::const_iterator p = input_sections.begin();
5930 p != input_sections.end();
5931 ++p)
5932 {
5933 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5934 == processed_input_sections.end())
5935 {
5936 // We discard a known EXIDX section because its linked
5937 // text section has been folded by ICF. We also discard an
5938 // EXIDX section with error, the output does not matter in this
5939 // case. We do this to avoid triggering asserts.
5940 Arm_relobj<big_endian>* arm_relobj =
5941 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5942 const Arm_exidx_input_section* exidx_input_section =
5943 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5944 gold_assert(exidx_input_section != NULL);
5945 if (!exidx_input_section->has_errors())
5946 {
5947 unsigned int text_shndx = exidx_input_section->link();
5948 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5949 }
5950
5951 // Remove this from link. We also need to recount the
5952 // local symbols.
5953 p->relobj()->set_output_section(p->shndx(), NULL);
5954 arm_relobj->set_output_local_symbol_count_needs_update();
5955 }
5956 }
5957
5958 // Link exidx output section to the first seen output section and
5959 // set correct entry size.
5960 this->set_link_section(exidx_fixup.first_output_text_section());
5961 this->set_entsize(8);
5962
5963 // Make changes permanent.
5964 this->save_states();
5965 this->set_section_offsets_need_adjustment();
5966 }
5967
5968 // Link EXIDX output sections to text output sections.
5969
5970 template<bool big_endian>
5971 void
5972 Arm_output_section<big_endian>::set_exidx_section_link()
5973 {
5974 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5975 if (!this->input_sections().empty())
5976 {
5977 Input_section_list::const_iterator p = this->input_sections().begin();
5978 Arm_relobj<big_endian>* arm_relobj =
5979 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5980 unsigned exidx_shndx = p->shndx();
5981 const Arm_exidx_input_section* exidx_input_section =
5982 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
5983 gold_assert(exidx_input_section != NULL);
5984 unsigned int text_shndx = exidx_input_section->link();
5985 Output_section* os = arm_relobj->output_section(text_shndx);
5986 this->set_link_section(os);
5987 }
5988 }
5989
5990 // Arm_relobj methods.
5991
5992 // Determine if an input section is scannable for stub processing. SHDR is
5993 // the header of the section and SHNDX is the section index. OS is the output
5994 // section for the input section and SYMTAB is the global symbol table used to
5995 // look up ICF information.
5996
5997 template<bool big_endian>
5998 bool
5999 Arm_relobj<big_endian>::section_is_scannable(
6000 const elfcpp::Shdr<32, big_endian>& shdr,
6001 unsigned int shndx,
6002 const Output_section* os,
6003 const Symbol_table* symtab)
6004 {
6005 // Skip any empty sections, unallocated sections or sections whose
6006 // type are not SHT_PROGBITS.
6007 if (shdr.get_sh_size() == 0
6008 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6009 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6010 return false;
6011
6012 // Skip any discarded or ICF'ed sections.
6013 if (os == NULL || symtab->is_section_folded(this, shndx))
6014 return false;
6015
6016 // If this requires special offset handling, check to see if it is
6017 // a relaxed section. If this is not, then it is a merged section that
6018 // we cannot handle.
6019 if (this->is_output_section_offset_invalid(shndx))
6020 {
6021 const Output_relaxed_input_section* poris =
6022 os->find_relaxed_input_section(this, shndx);
6023 if (poris == NULL)
6024 return false;
6025 }
6026
6027 return true;
6028 }
6029
6030 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6031 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6032
6033 template<bool big_endian>
6034 bool
6035 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6036 const elfcpp::Shdr<32, big_endian>& shdr,
6037 const Relobj::Output_sections& out_sections,
6038 const Symbol_table* symtab,
6039 const unsigned char* pshdrs)
6040 {
6041 unsigned int sh_type = shdr.get_sh_type();
6042 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6043 return false;
6044
6045 // Ignore empty section.
6046 off_t sh_size = shdr.get_sh_size();
6047 if (sh_size == 0)
6048 return false;
6049
6050 // Ignore reloc section with unexpected symbol table. The
6051 // error will be reported in the final link.
6052 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6053 return false;
6054
6055 unsigned int reloc_size;
6056 if (sh_type == elfcpp::SHT_REL)
6057 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6058 else
6059 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6060
6061 // Ignore reloc section with unexpected entsize or uneven size.
6062 // The error will be reported in the final link.
6063 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6064 return false;
6065
6066 // Ignore reloc section with bad info. This error will be
6067 // reported in the final link.
6068 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6069 if (index >= this->shnum())
6070 return false;
6071
6072 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6073 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6074 return this->section_is_scannable(text_shdr, index,
6075 out_sections[index], symtab);
6076 }
6077
6078 // Return the output address of either a plain input section or a relaxed
6079 // input section. SHNDX is the section index. We define and use this
6080 // instead of calling Output_section::output_address because that is slow
6081 // for large output.
6082
6083 template<bool big_endian>
6084 Arm_address
6085 Arm_relobj<big_endian>::simple_input_section_output_address(
6086 unsigned int shndx,
6087 Output_section* os)
6088 {
6089 if (this->is_output_section_offset_invalid(shndx))
6090 {
6091 const Output_relaxed_input_section* poris =
6092 os->find_relaxed_input_section(this, shndx);
6093 // We do not handle merged sections here.
6094 gold_assert(poris != NULL);
6095 return poris->address();
6096 }
6097 else
6098 return os->address() + this->get_output_section_offset(shndx);
6099 }
6100
6101 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6102 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6103
6104 template<bool big_endian>
6105 bool
6106 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6107 const elfcpp::Shdr<32, big_endian>& shdr,
6108 unsigned int shndx,
6109 Output_section* os,
6110 const Symbol_table* symtab)
6111 {
6112 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6113 return false;
6114
6115 // If the section does not cross any 4K-boundaries, it does not need to
6116 // be scanned.
6117 Arm_address address = this->simple_input_section_output_address(shndx, os);
6118 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6119 return false;
6120
6121 return true;
6122 }
6123
6124 // Scan a section for Cortex-A8 workaround.
6125
6126 template<bool big_endian>
6127 void
6128 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6129 const elfcpp::Shdr<32, big_endian>& shdr,
6130 unsigned int shndx,
6131 Output_section* os,
6132 Target_arm<big_endian>* arm_target)
6133 {
6134 // Look for the first mapping symbol in this section. It should be
6135 // at (shndx, 0).
6136 Mapping_symbol_position section_start(shndx, 0);
6137 typename Mapping_symbols_info::const_iterator p =
6138 this->mapping_symbols_info_.lower_bound(section_start);
6139
6140 // There are no mapping symbols for this section. Treat it as a data-only
6141 // section. Issue a warning if section is marked as containing
6142 // instructions.
6143 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6144 {
6145 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6146 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6147 "erratum because it has no mapping symbols."),
6148 shndx, this->name().c_str());
6149 return;
6150 }
6151
6152 Arm_address output_address =
6153 this->simple_input_section_output_address(shndx, os);
6154
6155 // Get the section contents.
6156 section_size_type input_view_size = 0;
6157 const unsigned char* input_view =
6158 this->section_contents(shndx, &input_view_size, false);
6159
6160 // We need to go through the mapping symbols to determine what to
6161 // scan. There are two reasons. First, we should look at THUMB code and
6162 // THUMB code only. Second, we only want to look at the 4K-page boundary
6163 // to speed up the scanning.
6164
6165 while (p != this->mapping_symbols_info_.end()
6166 && p->first.first == shndx)
6167 {
6168 typename Mapping_symbols_info::const_iterator next =
6169 this->mapping_symbols_info_.upper_bound(p->first);
6170
6171 // Only scan part of a section with THUMB code.
6172 if (p->second == 't')
6173 {
6174 // Determine the end of this range.
6175 section_size_type span_start =
6176 convert_to_section_size_type(p->first.second);
6177 section_size_type span_end;
6178 if (next != this->mapping_symbols_info_.end()
6179 && next->first.first == shndx)
6180 span_end = convert_to_section_size_type(next->first.second);
6181 else
6182 span_end = convert_to_section_size_type(shdr.get_sh_size());
6183
6184 if (((span_start + output_address) & ~0xfffUL)
6185 != ((span_end + output_address - 1) & ~0xfffUL))
6186 {
6187 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6188 span_start, span_end,
6189 input_view,
6190 output_address);
6191 }
6192 }
6193
6194 p = next;
6195 }
6196 }
6197
6198 // Scan relocations for stub generation.
6199
6200 template<bool big_endian>
6201 void
6202 Arm_relobj<big_endian>::scan_sections_for_stubs(
6203 Target_arm<big_endian>* arm_target,
6204 const Symbol_table* symtab,
6205 const Layout* layout)
6206 {
6207 unsigned int shnum = this->shnum();
6208 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6209
6210 // Read the section headers.
6211 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6212 shnum * shdr_size,
6213 true, true);
6214
6215 // To speed up processing, we set up hash tables for fast lookup of
6216 // input offsets to output addresses.
6217 this->initialize_input_to_output_maps();
6218
6219 const Relobj::Output_sections& out_sections(this->output_sections());
6220
6221 Relocate_info<32, big_endian> relinfo;
6222 relinfo.symtab = symtab;
6223 relinfo.layout = layout;
6224 relinfo.object = this;
6225
6226 // Do relocation stubs scanning.
6227 const unsigned char* p = pshdrs + shdr_size;
6228 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6229 {
6230 const elfcpp::Shdr<32, big_endian> shdr(p);
6231 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6232 pshdrs))
6233 {
6234 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6235 Arm_address output_offset = this->get_output_section_offset(index);
6236 Arm_address output_address;
6237 if (output_offset != invalid_address)
6238 output_address = out_sections[index]->address() + output_offset;
6239 else
6240 {
6241 // Currently this only happens for a relaxed section.
6242 const Output_relaxed_input_section* poris =
6243 out_sections[index]->find_relaxed_input_section(this, index);
6244 gold_assert(poris != NULL);
6245 output_address = poris->address();
6246 }
6247
6248 // Get the relocations.
6249 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6250 shdr.get_sh_size(),
6251 true, false);
6252
6253 // Get the section contents. This does work for the case in which
6254 // we modify the contents of an input section. We need to pass the
6255 // output view under such circumstances.
6256 section_size_type input_view_size = 0;
6257 const unsigned char* input_view =
6258 this->section_contents(index, &input_view_size, false);
6259
6260 relinfo.reloc_shndx = i;
6261 relinfo.data_shndx = index;
6262 unsigned int sh_type = shdr.get_sh_type();
6263 unsigned int reloc_size;
6264 if (sh_type == elfcpp::SHT_REL)
6265 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6266 else
6267 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6268
6269 Output_section* os = out_sections[index];
6270 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6271 shdr.get_sh_size() / reloc_size,
6272 os,
6273 output_offset == invalid_address,
6274 input_view, output_address,
6275 input_view_size);
6276 }
6277 }
6278
6279 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6280 // after its relocation section, if there is one, is processed for
6281 // relocation stubs. Merging this loop with the one above would have been
6282 // complicated since we would have had to make sure that relocation stub
6283 // scanning is done first.
6284 if (arm_target->fix_cortex_a8())
6285 {
6286 const unsigned char* p = pshdrs + shdr_size;
6287 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6288 {
6289 const elfcpp::Shdr<32, big_endian> shdr(p);
6290 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6291 out_sections[i],
6292 symtab))
6293 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6294 arm_target);
6295 }
6296 }
6297
6298 // After we've done the relocations, we release the hash tables,
6299 // since we no longer need them.
6300 this->free_input_to_output_maps();
6301 }
6302
6303 // Count the local symbols. The ARM backend needs to know if a symbol
6304 // is a THUMB function or not. For global symbols, it is easy because
6305 // the Symbol object keeps the ELF symbol type. For local symbol it is
6306 // harder because we cannot access this information. So we override the
6307 // do_count_local_symbol in parent and scan local symbols to mark
6308 // THUMB functions. This is not the most efficient way but I do not want to
6309 // slow down other ports by calling a per symbol target hook inside
6310 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6311
6312 template<bool big_endian>
6313 void
6314 Arm_relobj<big_endian>::do_count_local_symbols(
6315 Stringpool_template<char>* pool,
6316 Stringpool_template<char>* dynpool)
6317 {
6318 // We need to fix-up the values of any local symbols whose type are
6319 // STT_ARM_TFUNC.
6320
6321 // Ask parent to count the local symbols.
6322 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6323 const unsigned int loccount = this->local_symbol_count();
6324 if (loccount == 0)
6325 return;
6326
6327 // Initialize the thumb function bit-vector.
6328 std::vector<bool> empty_vector(loccount, false);
6329 this->local_symbol_is_thumb_function_.swap(empty_vector);
6330
6331 // Read the symbol table section header.
6332 const unsigned int symtab_shndx = this->symtab_shndx();
6333 elfcpp::Shdr<32, big_endian>
6334 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6335 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6336
6337 // Read the local symbols.
6338 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6339 gold_assert(loccount == symtabshdr.get_sh_info());
6340 off_t locsize = loccount * sym_size;
6341 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6342 locsize, true, true);
6343
6344 // For mapping symbol processing, we need to read the symbol names.
6345 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6346 if (strtab_shndx >= this->shnum())
6347 {
6348 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6349 return;
6350 }
6351
6352 elfcpp::Shdr<32, big_endian>
6353 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6354 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6355 {
6356 this->error(_("symbol table name section has wrong type: %u"),
6357 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6358 return;
6359 }
6360 const char* pnames =
6361 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6362 strtabshdr.get_sh_size(),
6363 false, false));
6364
6365 // Loop over the local symbols and mark any local symbols pointing
6366 // to THUMB functions.
6367
6368 // Skip the first dummy symbol.
6369 psyms += sym_size;
6370 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6371 this->local_values();
6372 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6373 {
6374 elfcpp::Sym<32, big_endian> sym(psyms);
6375 elfcpp::STT st_type = sym.get_st_type();
6376 Symbol_value<32>& lv((*plocal_values)[i]);
6377 Arm_address input_value = lv.input_value();
6378
6379 // Check to see if this is a mapping symbol.
6380 const char* sym_name = pnames + sym.get_st_name();
6381 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6382 {
6383 bool is_ordinary;
6384 unsigned int input_shndx =
6385 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6386 gold_assert(is_ordinary);
6387
6388 // Strip of LSB in case this is a THUMB symbol.
6389 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6390 this->mapping_symbols_info_[msp] = sym_name[1];
6391 }
6392
6393 if (st_type == elfcpp::STT_ARM_TFUNC
6394 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6395 {
6396 // This is a THUMB function. Mark this and canonicalize the
6397 // symbol value by setting LSB.
6398 this->local_symbol_is_thumb_function_[i] = true;
6399 if ((input_value & 1) == 0)
6400 lv.set_input_value(input_value | 1);
6401 }
6402 }
6403 }
6404
6405 // Relocate sections.
6406 template<bool big_endian>
6407 void
6408 Arm_relobj<big_endian>::do_relocate_sections(
6409 const Symbol_table* symtab,
6410 const Layout* layout,
6411 const unsigned char* pshdrs,
6412 Output_file* of,
6413 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6414 {
6415 // Call parent to relocate sections.
6416 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6417 pshdrs, of, pviews);
6418
6419 // We do not generate stubs if doing a relocatable link.
6420 if (parameters->options().relocatable())
6421 return;
6422
6423 // Relocate stub tables.
6424 unsigned int shnum = this->shnum();
6425
6426 Target_arm<big_endian>* arm_target =
6427 Target_arm<big_endian>::default_target();
6428
6429 Relocate_info<32, big_endian> relinfo;
6430 relinfo.symtab = symtab;
6431 relinfo.layout = layout;
6432 relinfo.object = this;
6433
6434 for (unsigned int i = 1; i < shnum; ++i)
6435 {
6436 Arm_input_section<big_endian>* arm_input_section =
6437 arm_target->find_arm_input_section(this, i);
6438
6439 if (arm_input_section != NULL
6440 && arm_input_section->is_stub_table_owner()
6441 && !arm_input_section->stub_table()->empty())
6442 {
6443 // We cannot discard a section if it owns a stub table.
6444 Output_section* os = this->output_section(i);
6445 gold_assert(os != NULL);
6446
6447 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6448 relinfo.reloc_shdr = NULL;
6449 relinfo.data_shndx = i;
6450 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6451
6452 gold_assert((*pviews)[i].view != NULL);
6453
6454 // We are passed the output section view. Adjust it to cover the
6455 // stub table only.
6456 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6457 gold_assert((stub_table->address() >= (*pviews)[i].address)
6458 && ((stub_table->address() + stub_table->data_size())
6459 <= (*pviews)[i].address + (*pviews)[i].view_size));
6460
6461 off_t offset = stub_table->address() - (*pviews)[i].address;
6462 unsigned char* view = (*pviews)[i].view + offset;
6463 Arm_address address = stub_table->address();
6464 section_size_type view_size = stub_table->data_size();
6465
6466 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6467 view_size);
6468 }
6469
6470 // Apply Cortex A8 workaround if applicable.
6471 if (this->section_has_cortex_a8_workaround(i))
6472 {
6473 unsigned char* view = (*pviews)[i].view;
6474 Arm_address view_address = (*pviews)[i].address;
6475 section_size_type view_size = (*pviews)[i].view_size;
6476 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6477
6478 // Adjust view to cover section.
6479 Output_section* os = this->output_section(i);
6480 gold_assert(os != NULL);
6481 Arm_address section_address =
6482 this->simple_input_section_output_address(i, os);
6483 uint64_t section_size = this->section_size(i);
6484
6485 gold_assert(section_address >= view_address
6486 && ((section_address + section_size)
6487 <= (view_address + view_size)));
6488
6489 unsigned char* section_view = view + (section_address - view_address);
6490
6491 // Apply the Cortex-A8 workaround to the output address range
6492 // corresponding to this input section.
6493 stub_table->apply_cortex_a8_workaround_to_address_range(
6494 arm_target,
6495 section_view,
6496 section_address,
6497 section_size);
6498 }
6499 }
6500 }
6501
6502 // Find the linked text section of an EXIDX section by looking at the first
6503 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6504 // must be linked to its associated code section via the sh_link field of
6505 // its section header. However, some tools are broken and the link is not
6506 // always set. LD just drops such an EXIDX section silently, causing the
6507 // associated code not unwindabled. Here we try a little bit harder to
6508 // discover the linked code section.
6509 //
6510 // PSHDR points to the section header of a relocation section of an EXIDX
6511 // section. If we can find a linked text section, return true and
6512 // store the text section index in the location PSHNDX. Otherwise
6513 // return false.
6514
6515 template<bool big_endian>
6516 bool
6517 Arm_relobj<big_endian>::find_linked_text_section(
6518 const unsigned char* pshdr,
6519 const unsigned char* psyms,
6520 unsigned int* pshndx)
6521 {
6522 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6523
6524 // If there is no relocation, we cannot find the linked text section.
6525 size_t reloc_size;
6526 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6527 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6528 else
6529 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6530 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6531
6532 // Get the relocations.
6533 const unsigned char* prelocs =
6534 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6535
6536 // Find the REL31 relocation for the first word of the first EXIDX entry.
6537 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6538 {
6539 Arm_address r_offset;
6540 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6541 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6542 {
6543 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6544 r_info = reloc.get_r_info();
6545 r_offset = reloc.get_r_offset();
6546 }
6547 else
6548 {
6549 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6550 r_info = reloc.get_r_info();
6551 r_offset = reloc.get_r_offset();
6552 }
6553
6554 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6555 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6556 continue;
6557
6558 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6559 if (r_sym == 0
6560 || r_sym >= this->local_symbol_count()
6561 || r_offset != 0)
6562 continue;
6563
6564 // This is the relocation for the first word of the first EXIDX entry.
6565 // We expect to see a local section symbol.
6566 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6567 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6568 if (sym.get_st_type() == elfcpp::STT_SECTION)
6569 {
6570 bool is_ordinary;
6571 *pshndx =
6572 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6573 gold_assert(is_ordinary);
6574 return true;
6575 }
6576 else
6577 return false;
6578 }
6579
6580 return false;
6581 }
6582
6583 // Make an EXIDX input section object for an EXIDX section whose index is
6584 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6585 // is the section index of the linked text section.
6586
6587 template<bool big_endian>
6588 void
6589 Arm_relobj<big_endian>::make_exidx_input_section(
6590 unsigned int shndx,
6591 const elfcpp::Shdr<32, big_endian>& shdr,
6592 unsigned int text_shndx,
6593 const elfcpp::Shdr<32, big_endian>& text_shdr)
6594 {
6595 // Create an Arm_exidx_input_section object for this EXIDX section.
6596 Arm_exidx_input_section* exidx_input_section =
6597 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6598 shdr.get_sh_addralign(),
6599 text_shdr.get_sh_size());
6600
6601 gold_assert(this->exidx_section_map_[shndx] == NULL);
6602 this->exidx_section_map_[shndx] = exidx_input_section;
6603
6604 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6605 {
6606 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6607 this->section_name(shndx).c_str(), shndx, text_shndx,
6608 this->name().c_str());
6609 exidx_input_section->set_has_errors();
6610 }
6611 else if (this->exidx_section_map_[text_shndx] != NULL)
6612 {
6613 unsigned other_exidx_shndx =
6614 this->exidx_section_map_[text_shndx]->shndx();
6615 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6616 "%s(%u) in %s"),
6617 this->section_name(shndx).c_str(), shndx,
6618 this->section_name(other_exidx_shndx).c_str(),
6619 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6620 text_shndx, this->name().c_str());
6621 exidx_input_section->set_has_errors();
6622 }
6623 else
6624 this->exidx_section_map_[text_shndx] = exidx_input_section;
6625
6626 // Check section flags of text section.
6627 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6628 {
6629 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6630 " in %s"),
6631 this->section_name(shndx).c_str(), shndx,
6632 this->section_name(text_shndx).c_str(), text_shndx,
6633 this->name().c_str());
6634 exidx_input_section->set_has_errors();
6635 }
6636 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6637 // I would like to make this an error but currently ld just ignores
6638 // this.
6639 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6640 "%s(%u) in %s"),
6641 this->section_name(shndx).c_str(), shndx,
6642 this->section_name(text_shndx).c_str(), text_shndx,
6643 this->name().c_str());
6644 }
6645
6646 // Read the symbol information.
6647
6648 template<bool big_endian>
6649 void
6650 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6651 {
6652 // Call parent class to read symbol information.
6653 Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6654
6655 // If this input file is a binary file, it has no processor
6656 // specific flags and attributes section.
6657 Input_file::Format format = this->input_file()->format();
6658 if (format != Input_file::FORMAT_ELF)
6659 {
6660 gold_assert(format == Input_file::FORMAT_BINARY);
6661 this->merge_flags_and_attributes_ = false;
6662 return;
6663 }
6664
6665 // Read processor-specific flags in ELF file header.
6666 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6667 elfcpp::Elf_sizes<32>::ehdr_size,
6668 true, false);
6669 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6670 this->processor_specific_flags_ = ehdr.get_e_flags();
6671
6672 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6673 // sections.
6674 std::vector<unsigned int> deferred_exidx_sections;
6675 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6676 const unsigned char* pshdrs = sd->section_headers->data();
6677 const unsigned char* ps = pshdrs + shdr_size;
6678 bool must_merge_flags_and_attributes = false;
6679 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6680 {
6681 elfcpp::Shdr<32, big_endian> shdr(ps);
6682
6683 // Sometimes an object has no contents except the section name string
6684 // table and an empty symbol table with the undefined symbol. We
6685 // don't want to merge processor-specific flags from such an object.
6686 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6687 {
6688 // Symbol table is not empty.
6689 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6690 elfcpp::Elf_sizes<32>::sym_size;
6691 if (shdr.get_sh_size() > sym_size)
6692 must_merge_flags_and_attributes = true;
6693 }
6694 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6695 // If this is neither an empty symbol table nor a string table,
6696 // be conservative.
6697 must_merge_flags_and_attributes = true;
6698
6699 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6700 {
6701 gold_assert(this->attributes_section_data_ == NULL);
6702 section_offset_type section_offset = shdr.get_sh_offset();
6703 section_size_type section_size =
6704 convert_to_section_size_type(shdr.get_sh_size());
6705 const unsigned char* view =
6706 this->get_view(section_offset, section_size, true, false);
6707 this->attributes_section_data_ =
6708 new Attributes_section_data(view, section_size);
6709 }
6710 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6711 {
6712 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6713 if (text_shndx == elfcpp::SHN_UNDEF)
6714 deferred_exidx_sections.push_back(i);
6715 else
6716 {
6717 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6718 + text_shndx * shdr_size);
6719 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6720 }
6721 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6722 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6723 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6724 this->section_name(i).c_str(), this->name().c_str());
6725 }
6726 }
6727
6728 // This is rare.
6729 if (!must_merge_flags_and_attributes)
6730 {
6731 gold_assert(deferred_exidx_sections.empty());
6732 this->merge_flags_and_attributes_ = false;
6733 return;
6734 }
6735
6736 // Some tools are broken and they do not set the link of EXIDX sections.
6737 // We look at the first relocation to figure out the linked sections.
6738 if (!deferred_exidx_sections.empty())
6739 {
6740 // We need to go over the section headers again to find the mapping
6741 // from sections being relocated to their relocation sections. This is
6742 // a bit inefficient as we could do that in the loop above. However,
6743 // we do not expect any deferred EXIDX sections normally. So we do not
6744 // want to slow down the most common path.
6745 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6746 Reloc_map reloc_map;
6747 ps = pshdrs + shdr_size;
6748 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6749 {
6750 elfcpp::Shdr<32, big_endian> shdr(ps);
6751 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6752 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6753 {
6754 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6755 if (info_shndx >= this->shnum())
6756 gold_error(_("relocation section %u has invalid info %u"),
6757 i, info_shndx);
6758 Reloc_map::value_type value(info_shndx, i);
6759 std::pair<Reloc_map::iterator, bool> result =
6760 reloc_map.insert(value);
6761 if (!result.second)
6762 gold_error(_("section %u has multiple relocation sections "
6763 "%u and %u"),
6764 info_shndx, i, reloc_map[info_shndx]);
6765 }
6766 }
6767
6768 // Read the symbol table section header.
6769 const unsigned int symtab_shndx = this->symtab_shndx();
6770 elfcpp::Shdr<32, big_endian>
6771 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6772 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6773
6774 // Read the local symbols.
6775 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6776 const unsigned int loccount = this->local_symbol_count();
6777 gold_assert(loccount == symtabshdr.get_sh_info());
6778 off_t locsize = loccount * sym_size;
6779 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6780 locsize, true, true);
6781
6782 // Process the deferred EXIDX sections.
6783 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6784 {
6785 unsigned int shndx = deferred_exidx_sections[i];
6786 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6787 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6788 Reloc_map::const_iterator it = reloc_map.find(shndx);
6789 if (it != reloc_map.end())
6790 find_linked_text_section(pshdrs + it->second * shdr_size,
6791 psyms, &text_shndx);
6792 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6793 + text_shndx * shdr_size);
6794 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6795 }
6796 }
6797 }
6798
6799 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6800 // sections for unwinding. These sections are referenced implicitly by
6801 // text sections linked in the section headers. If we ignore these implicit
6802 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6803 // will be garbage-collected incorrectly. Hence we override the same function
6804 // in the base class to handle these implicit references.
6805
6806 template<bool big_endian>
6807 void
6808 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6809 Layout* layout,
6810 Read_relocs_data* rd)
6811 {
6812 // First, call base class method to process relocations in this object.
6813 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6814
6815 // If --gc-sections is not specified, there is nothing more to do.
6816 // This happens when --icf is used but --gc-sections is not.
6817 if (!parameters->options().gc_sections())
6818 return;
6819
6820 unsigned int shnum = this->shnum();
6821 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6822 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6823 shnum * shdr_size,
6824 true, true);
6825
6826 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6827 // to these from the linked text sections.
6828 const unsigned char* ps = pshdrs + shdr_size;
6829 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6830 {
6831 elfcpp::Shdr<32, big_endian> shdr(ps);
6832 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6833 {
6834 // Found an .ARM.exidx section, add it to the set of reachable
6835 // sections from its linked text section.
6836 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6837 symtab->gc()->add_reference(this, text_shndx, this, i);
6838 }
6839 }
6840 }
6841
6842 // Update output local symbol count. Owing to EXIDX entry merging, some local
6843 // symbols will be removed in output. Adjust output local symbol count
6844 // accordingly. We can only changed the static output local symbol count. It
6845 // is too late to change the dynamic symbols.
6846
6847 template<bool big_endian>
6848 void
6849 Arm_relobj<big_endian>::update_output_local_symbol_count()
6850 {
6851 // Caller should check that this needs updating. We want caller checking
6852 // because output_local_symbol_count_needs_update() is most likely inlined.
6853 gold_assert(this->output_local_symbol_count_needs_update_);
6854
6855 gold_assert(this->symtab_shndx() != -1U);
6856 if (this->symtab_shndx() == 0)
6857 {
6858 // This object has no symbols. Weird but legal.
6859 return;
6860 }
6861
6862 // Read the symbol table section header.
6863 const unsigned int symtab_shndx = this->symtab_shndx();
6864 elfcpp::Shdr<32, big_endian>
6865 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6866 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6867
6868 // Read the local symbols.
6869 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6870 const unsigned int loccount = this->local_symbol_count();
6871 gold_assert(loccount == symtabshdr.get_sh_info());
6872 off_t locsize = loccount * sym_size;
6873 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6874 locsize, true, true);
6875
6876 // Loop over the local symbols.
6877
6878 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6879 Output_sections;
6880 const Output_sections& out_sections(this->output_sections());
6881 unsigned int shnum = this->shnum();
6882 unsigned int count = 0;
6883 // Skip the first, dummy, symbol.
6884 psyms += sym_size;
6885 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6886 {
6887 elfcpp::Sym<32, big_endian> sym(psyms);
6888
6889 Symbol_value<32>& lv((*this->local_values())[i]);
6890
6891 // This local symbol was already discarded by do_count_local_symbols.
6892 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6893 continue;
6894
6895 bool is_ordinary;
6896 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6897 &is_ordinary);
6898
6899 if (shndx < shnum)
6900 {
6901 Output_section* os = out_sections[shndx];
6902
6903 // This local symbol no longer has an output section. Discard it.
6904 if (os == NULL)
6905 {
6906 lv.set_no_output_symtab_entry();
6907 continue;
6908 }
6909
6910 // Currently we only discard parts of EXIDX input sections.
6911 // We explicitly check for a merged EXIDX input section to avoid
6912 // calling Output_section_data::output_offset unless necessary.
6913 if ((this->get_output_section_offset(shndx) == invalid_address)
6914 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6915 {
6916 section_offset_type output_offset =
6917 os->output_offset(this, shndx, lv.input_value());
6918 if (output_offset == -1)
6919 {
6920 // This symbol is defined in a part of an EXIDX input section
6921 // that is discarded due to entry merging.
6922 lv.set_no_output_symtab_entry();
6923 continue;
6924 }
6925 }
6926 }
6927
6928 ++count;
6929 }
6930
6931 this->set_output_local_symbol_count(count);
6932 this->output_local_symbol_count_needs_update_ = false;
6933 }
6934
6935 // Arm_dynobj methods.
6936
6937 // Read the symbol information.
6938
6939 template<bool big_endian>
6940 void
6941 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6942 {
6943 // Call parent class to read symbol information.
6944 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6945
6946 // Read processor-specific flags in ELF file header.
6947 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6948 elfcpp::Elf_sizes<32>::ehdr_size,
6949 true, false);
6950 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6951 this->processor_specific_flags_ = ehdr.get_e_flags();
6952
6953 // Read the attributes section if there is one.
6954 // We read from the end because gas seems to put it near the end of
6955 // the section headers.
6956 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6957 const unsigned char* ps =
6958 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6959 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6960 {
6961 elfcpp::Shdr<32, big_endian> shdr(ps);
6962 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6963 {
6964 section_offset_type section_offset = shdr.get_sh_offset();
6965 section_size_type section_size =
6966 convert_to_section_size_type(shdr.get_sh_size());
6967 const unsigned char* view =
6968 this->get_view(section_offset, section_size, true, false);
6969 this->attributes_section_data_ =
6970 new Attributes_section_data(view, section_size);
6971 break;
6972 }
6973 }
6974 }
6975
6976 // Stub_addend_reader methods.
6977
6978 // Read the addend of a REL relocation of type R_TYPE at VIEW.
6979
6980 template<bool big_endian>
6981 elfcpp::Elf_types<32>::Elf_Swxword
6982 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
6983 unsigned int r_type,
6984 const unsigned char* view,
6985 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
6986 {
6987 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
6988
6989 switch (r_type)
6990 {
6991 case elfcpp::R_ARM_CALL:
6992 case elfcpp::R_ARM_JUMP24:
6993 case elfcpp::R_ARM_PLT32:
6994 {
6995 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6996 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6997 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
6998 return Bits<26>::sign_extend32(val << 2);
6999 }
7000
7001 case elfcpp::R_ARM_THM_CALL:
7002 case elfcpp::R_ARM_THM_JUMP24:
7003 case elfcpp::R_ARM_THM_XPC22:
7004 {
7005 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7006 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7007 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7008 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7009 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7010 }
7011
7012 case elfcpp::R_ARM_THM_JUMP19:
7013 {
7014 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7015 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7016 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7017 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7018 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7019 }
7020
7021 default:
7022 gold_unreachable();
7023 }
7024 }
7025
7026 // Arm_output_data_got methods.
7027
7028 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7029 // The first one is initialized to be 1, which is the module index for
7030 // the main executable and the second one 0. A reloc of the type
7031 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7032 // be applied by gold. GSYM is a global symbol.
7033 //
7034 template<bool big_endian>
7035 void
7036 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7037 unsigned int got_type,
7038 Symbol* gsym)
7039 {
7040 if (gsym->has_got_offset(got_type))
7041 return;
7042
7043 // We are doing a static link. Just mark it as belong to module 1,
7044 // the executable.
7045 unsigned int got_offset = this->add_constant(1);
7046 gsym->set_got_offset(got_type, got_offset);
7047 got_offset = this->add_constant(0);
7048 this->static_relocs_.push_back(Static_reloc(got_offset,
7049 elfcpp::R_ARM_TLS_DTPOFF32,
7050 gsym));
7051 }
7052
7053 // Same as the above but for a local symbol.
7054
7055 template<bool big_endian>
7056 void
7057 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7058 unsigned int got_type,
7059 Sized_relobj_file<32, big_endian>* object,
7060 unsigned int index)
7061 {
7062 if (object->local_has_got_offset(index, got_type))
7063 return;
7064
7065 // We are doing a static link. Just mark it as belong to module 1,
7066 // the executable.
7067 unsigned int got_offset = this->add_constant(1);
7068 object->set_local_got_offset(index, got_type, got_offset);
7069 got_offset = this->add_constant(0);
7070 this->static_relocs_.push_back(Static_reloc(got_offset,
7071 elfcpp::R_ARM_TLS_DTPOFF32,
7072 object, index));
7073 }
7074
7075 template<bool big_endian>
7076 void
7077 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7078 {
7079 // Call parent to write out GOT.
7080 Output_data_got<32, big_endian>::do_write(of);
7081
7082 // We are done if there is no fix up.
7083 if (this->static_relocs_.empty())
7084 return;
7085
7086 gold_assert(parameters->doing_static_link());
7087
7088 const off_t offset = this->offset();
7089 const section_size_type oview_size =
7090 convert_to_section_size_type(this->data_size());
7091 unsigned char* const oview = of->get_output_view(offset, oview_size);
7092
7093 Output_segment* tls_segment = this->layout_->tls_segment();
7094 gold_assert(tls_segment != NULL);
7095
7096 // The thread pointer $tp points to the TCB, which is followed by the
7097 // TLS. So we need to adjust $tp relative addressing by this amount.
7098 Arm_address aligned_tcb_size =
7099 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7100
7101 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7102 {
7103 Static_reloc& reloc(this->static_relocs_[i]);
7104
7105 Arm_address value;
7106 if (!reloc.symbol_is_global())
7107 {
7108 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7109 const Symbol_value<32>* psymval =
7110 reloc.relobj()->local_symbol(reloc.index());
7111
7112 // We are doing static linking. Issue an error and skip this
7113 // relocation if the symbol is undefined or in a discarded_section.
7114 bool is_ordinary;
7115 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7116 if ((shndx == elfcpp::SHN_UNDEF)
7117 || (is_ordinary
7118 && shndx != elfcpp::SHN_UNDEF
7119 && !object->is_section_included(shndx)
7120 && !this->symbol_table_->is_section_folded(object, shndx)))
7121 {
7122 gold_error(_("undefined or discarded local symbol %u from "
7123 " object %s in GOT"),
7124 reloc.index(), reloc.relobj()->name().c_str());
7125 continue;
7126 }
7127
7128 value = psymval->value(object, 0);
7129 }
7130 else
7131 {
7132 const Symbol* gsym = reloc.symbol();
7133 gold_assert(gsym != NULL);
7134 if (gsym->is_forwarder())
7135 gsym = this->symbol_table_->resolve_forwards(gsym);
7136
7137 // We are doing static linking. Issue an error and skip this
7138 // relocation if the symbol is undefined or in a discarded_section
7139 // unless it is a weakly_undefined symbol.
7140 if ((gsym->is_defined_in_discarded_section()
7141 || gsym->is_undefined())
7142 && !gsym->is_weak_undefined())
7143 {
7144 gold_error(_("undefined or discarded symbol %s in GOT"),
7145 gsym->name());
7146 continue;
7147 }
7148
7149 if (!gsym->is_weak_undefined())
7150 {
7151 const Sized_symbol<32>* sym =
7152 static_cast<const Sized_symbol<32>*>(gsym);
7153 value = sym->value();
7154 }
7155 else
7156 value = 0;
7157 }
7158
7159 unsigned got_offset = reloc.got_offset();
7160 gold_assert(got_offset < oview_size);
7161
7162 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7163 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7164 Valtype x;
7165 switch (reloc.r_type())
7166 {
7167 case elfcpp::R_ARM_TLS_DTPOFF32:
7168 x = value;
7169 break;
7170 case elfcpp::R_ARM_TLS_TPOFF32:
7171 x = value + aligned_tcb_size;
7172 break;
7173 default:
7174 gold_unreachable();
7175 }
7176 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7177 }
7178
7179 of->write_output_view(offset, oview_size, oview);
7180 }
7181
7182 // A class to handle the PLT data.
7183
7184 template<bool big_endian>
7185 class Output_data_plt_arm : public Output_section_data
7186 {
7187 public:
7188 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7189 Reloc_section;
7190
7191 Output_data_plt_arm(Layout*, Output_data_space*);
7192
7193 // Add an entry to the PLT.
7194 void
7195 add_entry(Symbol* gsym);
7196
7197 // Return the .rel.plt section data.
7198 const Reloc_section*
7199 rel_plt() const
7200 { return this->rel_; }
7201
7202 // Return the number of PLT entries.
7203 unsigned int
7204 entry_count() const
7205 { return this->count_; }
7206
7207 // Return the offset of the first non-reserved PLT entry.
7208 static unsigned int
7209 first_plt_entry_offset()
7210 { return sizeof(first_plt_entry); }
7211
7212 // Return the size of a PLT entry.
7213 static unsigned int
7214 get_plt_entry_size()
7215 { return sizeof(plt_entry); }
7216
7217 protected:
7218 void
7219 do_adjust_output_section(Output_section* os);
7220
7221 // Write to a map file.
7222 void
7223 do_print_to_mapfile(Mapfile* mapfile) const
7224 { mapfile->print_output_data(this, _("** PLT")); }
7225
7226 private:
7227 // Template for the first PLT entry.
7228 static const uint32_t first_plt_entry[5];
7229
7230 // Template for subsequent PLT entries.
7231 static const uint32_t plt_entry[3];
7232
7233 // Set the final size.
7234 void
7235 set_final_data_size()
7236 {
7237 this->set_data_size(sizeof(first_plt_entry)
7238 + this->count_ * sizeof(plt_entry));
7239 }
7240
7241 // Write out the PLT data.
7242 void
7243 do_write(Output_file*);
7244
7245 // The reloc section.
7246 Reloc_section* rel_;
7247 // The .got.plt section.
7248 Output_data_space* got_plt_;
7249 // The number of PLT entries.
7250 unsigned int count_;
7251 };
7252
7253 // Create the PLT section. The ordinary .got section is an argument,
7254 // since we need to refer to the start. We also create our own .got
7255 // section just for PLT entries.
7256
7257 template<bool big_endian>
7258 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7259 Output_data_space* got_plt)
7260 : Output_section_data(4), got_plt_(got_plt), count_(0)
7261 {
7262 this->rel_ = new Reloc_section(false);
7263 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7264 elfcpp::SHF_ALLOC, this->rel_,
7265 ORDER_DYNAMIC_PLT_RELOCS, false);
7266 }
7267
7268 template<bool big_endian>
7269 void
7270 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7271 {
7272 os->set_entsize(0);
7273 }
7274
7275 // Add an entry to the PLT.
7276
7277 template<bool big_endian>
7278 void
7279 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7280 {
7281 gold_assert(!gsym->has_plt_offset());
7282
7283 // Note that when setting the PLT offset we skip the initial
7284 // reserved PLT entry.
7285 gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
7286 + sizeof(first_plt_entry));
7287
7288 ++this->count_;
7289
7290 section_offset_type got_offset = this->got_plt_->current_data_size();
7291
7292 // Every PLT entry needs a GOT entry which points back to the PLT
7293 // entry (this will be changed by the dynamic linker, normally
7294 // lazily when the function is called).
7295 this->got_plt_->set_current_data_size(got_offset + 4);
7296
7297 // Every PLT entry needs a reloc.
7298 gsym->set_needs_dynsym_entry();
7299 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7300 got_offset);
7301
7302 // Note that we don't need to save the symbol. The contents of the
7303 // PLT are independent of which symbols are used. The symbols only
7304 // appear in the relocations.
7305 }
7306
7307 // ARM PLTs.
7308 // FIXME: This is not very flexible. Right now this has only been tested
7309 // on armv5te. If we are to support additional architecture features like
7310 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7311
7312 // The first entry in the PLT.
7313 template<bool big_endian>
7314 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
7315 {
7316 0xe52de004, // str lr, [sp, #-4]!
7317 0xe59fe004, // ldr lr, [pc, #4]
7318 0xe08fe00e, // add lr, pc, lr
7319 0xe5bef008, // ldr pc, [lr, #8]!
7320 0x00000000, // &GOT[0] - .
7321 };
7322
7323 // Subsequent entries in the PLT.
7324
7325 template<bool big_endian>
7326 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
7327 {
7328 0xe28fc600, // add ip, pc, #0xNN00000
7329 0xe28cca00, // add ip, ip, #0xNN000
7330 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7331 };
7332
7333 // Write out the PLT. This uses the hand-coded instructions above,
7334 // and adjusts them as needed. This is all specified by the arm ELF
7335 // Processor Supplement.
7336
7337 template<bool big_endian>
7338 void
7339 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7340 {
7341 const off_t offset = this->offset();
7342 const section_size_type oview_size =
7343 convert_to_section_size_type(this->data_size());
7344 unsigned char* const oview = of->get_output_view(offset, oview_size);
7345
7346 const off_t got_file_offset = this->got_plt_->offset();
7347 const section_size_type got_size =
7348 convert_to_section_size_type(this->got_plt_->data_size());
7349 unsigned char* const got_view = of->get_output_view(got_file_offset,
7350 got_size);
7351 unsigned char* pov = oview;
7352
7353 Arm_address plt_address = this->address();
7354 Arm_address got_address = this->got_plt_->address();
7355
7356 // Write first PLT entry. All but the last word are constants.
7357 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7358 / sizeof(plt_entry[0]));
7359 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7360 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7361 // Last word in first PLT entry is &GOT[0] - .
7362 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7363 got_address - (plt_address + 16));
7364 pov += sizeof(first_plt_entry);
7365
7366 unsigned char* got_pov = got_view;
7367
7368 memset(got_pov, 0, 12);
7369 got_pov += 12;
7370
7371 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
7372 unsigned int plt_offset = sizeof(first_plt_entry);
7373 unsigned int plt_rel_offset = 0;
7374 unsigned int got_offset = 12;
7375 const unsigned int count = this->count_;
7376 for (unsigned int i = 0;
7377 i < count;
7378 ++i,
7379 pov += sizeof(plt_entry),
7380 got_pov += 4,
7381 plt_offset += sizeof(plt_entry),
7382 plt_rel_offset += rel_size,
7383 got_offset += 4)
7384 {
7385 // Set and adjust the PLT entry itself.
7386 int32_t offset = ((got_address + got_offset)
7387 - (plt_address + plt_offset + 8));
7388
7389 gold_assert(offset >= 0 && offset < 0x0fffffff);
7390 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7391 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7392 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7393 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7394 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7395 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7396
7397 // Set the entry in the GOT.
7398 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7399 }
7400
7401 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7402 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7403
7404 of->write_output_view(offset, oview_size, oview);
7405 of->write_output_view(got_file_offset, got_size, got_view);
7406 }
7407
7408 // Create a PLT entry for a global symbol.
7409
7410 template<bool big_endian>
7411 void
7412 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7413 Symbol* gsym)
7414 {
7415 if (gsym->has_plt_offset())
7416 return;
7417
7418 if (this->plt_ == NULL)
7419 {
7420 // Create the GOT sections first.
7421 this->got_section(symtab, layout);
7422
7423 this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7424 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7425 (elfcpp::SHF_ALLOC
7426 | elfcpp::SHF_EXECINSTR),
7427 this->plt_, ORDER_PLT, false);
7428 }
7429 this->plt_->add_entry(gsym);
7430 }
7431
7432 // Return the number of entries in the PLT.
7433
7434 template<bool big_endian>
7435 unsigned int
7436 Target_arm<big_endian>::plt_entry_count() const
7437 {
7438 if (this->plt_ == NULL)
7439 return 0;
7440 return this->plt_->entry_count();
7441 }
7442
7443 // Return the offset of the first non-reserved PLT entry.
7444
7445 template<bool big_endian>
7446 unsigned int
7447 Target_arm<big_endian>::first_plt_entry_offset() const
7448 {
7449 return Output_data_plt_arm<big_endian>::first_plt_entry_offset();
7450 }
7451
7452 // Return the size of each PLT entry.
7453
7454 template<bool big_endian>
7455 unsigned int
7456 Target_arm<big_endian>::plt_entry_size() const
7457 {
7458 return Output_data_plt_arm<big_endian>::get_plt_entry_size();
7459 }
7460
7461 // Get the section to use for TLS_DESC relocations.
7462
7463 template<bool big_endian>
7464 typename Target_arm<big_endian>::Reloc_section*
7465 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7466 {
7467 return this->plt_section()->rel_tls_desc(layout);
7468 }
7469
7470 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7471
7472 template<bool big_endian>
7473 void
7474 Target_arm<big_endian>::define_tls_base_symbol(
7475 Symbol_table* symtab,
7476 Layout* layout)
7477 {
7478 if (this->tls_base_symbol_defined_)
7479 return;
7480
7481 Output_segment* tls_segment = layout->tls_segment();
7482 if (tls_segment != NULL)
7483 {
7484 bool is_exec = parameters->options().output_is_executable();
7485 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7486 Symbol_table::PREDEFINED,
7487 tls_segment, 0, 0,
7488 elfcpp::STT_TLS,
7489 elfcpp::STB_LOCAL,
7490 elfcpp::STV_HIDDEN, 0,
7491 (is_exec
7492 ? Symbol::SEGMENT_END
7493 : Symbol::SEGMENT_START),
7494 true);
7495 }
7496 this->tls_base_symbol_defined_ = true;
7497 }
7498
7499 // Create a GOT entry for the TLS module index.
7500
7501 template<bool big_endian>
7502 unsigned int
7503 Target_arm<big_endian>::got_mod_index_entry(
7504 Symbol_table* symtab,
7505 Layout* layout,
7506 Sized_relobj_file<32, big_endian>* object)
7507 {
7508 if (this->got_mod_index_offset_ == -1U)
7509 {
7510 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7511 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7512 unsigned int got_offset;
7513 if (!parameters->doing_static_link())
7514 {
7515 got_offset = got->add_constant(0);
7516 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7517 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7518 got_offset);
7519 }
7520 else
7521 {
7522 // We are doing a static link. Just mark it as belong to module 1,
7523 // the executable.
7524 got_offset = got->add_constant(1);
7525 }
7526
7527 got->add_constant(0);
7528 this->got_mod_index_offset_ = got_offset;
7529 }
7530 return this->got_mod_index_offset_;
7531 }
7532
7533 // Optimize the TLS relocation type based on what we know about the
7534 // symbol. IS_FINAL is true if the final address of this symbol is
7535 // known at link time.
7536
7537 template<bool big_endian>
7538 tls::Tls_optimization
7539 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7540 {
7541 // FIXME: Currently we do not do any TLS optimization.
7542 return tls::TLSOPT_NONE;
7543 }
7544
7545 // Get the Reference_flags for a particular relocation.
7546
7547 template<bool big_endian>
7548 int
7549 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7550 {
7551 switch (r_type)
7552 {
7553 case elfcpp::R_ARM_NONE:
7554 case elfcpp::R_ARM_V4BX:
7555 case elfcpp::R_ARM_GNU_VTENTRY:
7556 case elfcpp::R_ARM_GNU_VTINHERIT:
7557 // No symbol reference.
7558 return 0;
7559
7560 case elfcpp::R_ARM_ABS32:
7561 case elfcpp::R_ARM_ABS16:
7562 case elfcpp::R_ARM_ABS12:
7563 case elfcpp::R_ARM_THM_ABS5:
7564 case elfcpp::R_ARM_ABS8:
7565 case elfcpp::R_ARM_BASE_ABS:
7566 case elfcpp::R_ARM_MOVW_ABS_NC:
7567 case elfcpp::R_ARM_MOVT_ABS:
7568 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7569 case elfcpp::R_ARM_THM_MOVT_ABS:
7570 case elfcpp::R_ARM_ABS32_NOI:
7571 return Symbol::ABSOLUTE_REF;
7572
7573 case elfcpp::R_ARM_REL32:
7574 case elfcpp::R_ARM_LDR_PC_G0:
7575 case elfcpp::R_ARM_SBREL32:
7576 case elfcpp::R_ARM_THM_PC8:
7577 case elfcpp::R_ARM_BASE_PREL:
7578 case elfcpp::R_ARM_MOVW_PREL_NC:
7579 case elfcpp::R_ARM_MOVT_PREL:
7580 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7581 case elfcpp::R_ARM_THM_MOVT_PREL:
7582 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7583 case elfcpp::R_ARM_THM_PC12:
7584 case elfcpp::R_ARM_REL32_NOI:
7585 case elfcpp::R_ARM_ALU_PC_G0_NC:
7586 case elfcpp::R_ARM_ALU_PC_G0:
7587 case elfcpp::R_ARM_ALU_PC_G1_NC:
7588 case elfcpp::R_ARM_ALU_PC_G1:
7589 case elfcpp::R_ARM_ALU_PC_G2:
7590 case elfcpp::R_ARM_LDR_PC_G1:
7591 case elfcpp::R_ARM_LDR_PC_G2:
7592 case elfcpp::R_ARM_LDRS_PC_G0:
7593 case elfcpp::R_ARM_LDRS_PC_G1:
7594 case elfcpp::R_ARM_LDRS_PC_G2:
7595 case elfcpp::R_ARM_LDC_PC_G0:
7596 case elfcpp::R_ARM_LDC_PC_G1:
7597 case elfcpp::R_ARM_LDC_PC_G2:
7598 case elfcpp::R_ARM_ALU_SB_G0_NC:
7599 case elfcpp::R_ARM_ALU_SB_G0:
7600 case elfcpp::R_ARM_ALU_SB_G1_NC:
7601 case elfcpp::R_ARM_ALU_SB_G1:
7602 case elfcpp::R_ARM_ALU_SB_G2:
7603 case elfcpp::R_ARM_LDR_SB_G0:
7604 case elfcpp::R_ARM_LDR_SB_G1:
7605 case elfcpp::R_ARM_LDR_SB_G2:
7606 case elfcpp::R_ARM_LDRS_SB_G0:
7607 case elfcpp::R_ARM_LDRS_SB_G1:
7608 case elfcpp::R_ARM_LDRS_SB_G2:
7609 case elfcpp::R_ARM_LDC_SB_G0:
7610 case elfcpp::R_ARM_LDC_SB_G1:
7611 case elfcpp::R_ARM_LDC_SB_G2:
7612 case elfcpp::R_ARM_MOVW_BREL_NC:
7613 case elfcpp::R_ARM_MOVT_BREL:
7614 case elfcpp::R_ARM_MOVW_BREL:
7615 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7616 case elfcpp::R_ARM_THM_MOVT_BREL:
7617 case elfcpp::R_ARM_THM_MOVW_BREL:
7618 case elfcpp::R_ARM_GOTOFF32:
7619 case elfcpp::R_ARM_GOTOFF12:
7620 case elfcpp::R_ARM_SBREL31:
7621 return Symbol::RELATIVE_REF;
7622
7623 case elfcpp::R_ARM_PLT32:
7624 case elfcpp::R_ARM_CALL:
7625 case elfcpp::R_ARM_JUMP24:
7626 case elfcpp::R_ARM_THM_CALL:
7627 case elfcpp::R_ARM_THM_JUMP24:
7628 case elfcpp::R_ARM_THM_JUMP19:
7629 case elfcpp::R_ARM_THM_JUMP6:
7630 case elfcpp::R_ARM_THM_JUMP11:
7631 case elfcpp::R_ARM_THM_JUMP8:
7632 // R_ARM_PREL31 is not used to relocate call/jump instructions but
7633 // in unwind tables. It may point to functions via PLTs.
7634 // So we treat it like call/jump relocations above.
7635 case elfcpp::R_ARM_PREL31:
7636 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7637
7638 case elfcpp::R_ARM_GOT_BREL:
7639 case elfcpp::R_ARM_GOT_ABS:
7640 case elfcpp::R_ARM_GOT_PREL:
7641 // Absolute in GOT.
7642 return Symbol::ABSOLUTE_REF;
7643
7644 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7645 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7646 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7647 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7648 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7649 return Symbol::TLS_REF;
7650
7651 case elfcpp::R_ARM_TARGET1:
7652 case elfcpp::R_ARM_TARGET2:
7653 case elfcpp::R_ARM_COPY:
7654 case elfcpp::R_ARM_GLOB_DAT:
7655 case elfcpp::R_ARM_JUMP_SLOT:
7656 case elfcpp::R_ARM_RELATIVE:
7657 case elfcpp::R_ARM_PC24:
7658 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7659 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7660 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7661 default:
7662 // Not expected. We will give an error later.
7663 return 0;
7664 }
7665 }
7666
7667 // Report an unsupported relocation against a local symbol.
7668
7669 template<bool big_endian>
7670 void
7671 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7672 Sized_relobj_file<32, big_endian>* object,
7673 unsigned int r_type)
7674 {
7675 gold_error(_("%s: unsupported reloc %u against local symbol"),
7676 object->name().c_str(), r_type);
7677 }
7678
7679 // We are about to emit a dynamic relocation of type R_TYPE. If the
7680 // dynamic linker does not support it, issue an error. The GNU linker
7681 // only issues a non-PIC error for an allocated read-only section.
7682 // Here we know the section is allocated, but we don't know that it is
7683 // read-only. But we check for all the relocation types which the
7684 // glibc dynamic linker supports, so it seems appropriate to issue an
7685 // error even if the section is not read-only.
7686
7687 template<bool big_endian>
7688 void
7689 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7690 unsigned int r_type)
7691 {
7692 switch (r_type)
7693 {
7694 // These are the relocation types supported by glibc for ARM.
7695 case elfcpp::R_ARM_RELATIVE:
7696 case elfcpp::R_ARM_COPY:
7697 case elfcpp::R_ARM_GLOB_DAT:
7698 case elfcpp::R_ARM_JUMP_SLOT:
7699 case elfcpp::R_ARM_ABS32:
7700 case elfcpp::R_ARM_ABS32_NOI:
7701 case elfcpp::R_ARM_PC24:
7702 // FIXME: The following 3 types are not supported by Android's dynamic
7703 // linker.
7704 case elfcpp::R_ARM_TLS_DTPMOD32:
7705 case elfcpp::R_ARM_TLS_DTPOFF32:
7706 case elfcpp::R_ARM_TLS_TPOFF32:
7707 return;
7708
7709 default:
7710 {
7711 // This prevents us from issuing more than one error per reloc
7712 // section. But we can still wind up issuing more than one
7713 // error per object file.
7714 if (this->issued_non_pic_error_)
7715 return;
7716 const Arm_reloc_property* reloc_property =
7717 arm_reloc_property_table->get_reloc_property(r_type);
7718 gold_assert(reloc_property != NULL);
7719 object->error(_("requires unsupported dynamic reloc %s; "
7720 "recompile with -fPIC"),
7721 reloc_property->name().c_str());
7722 this->issued_non_pic_error_ = true;
7723 return;
7724 }
7725
7726 case elfcpp::R_ARM_NONE:
7727 gold_unreachable();
7728 }
7729 }
7730
7731 // Scan a relocation for a local symbol.
7732 // FIXME: This only handles a subset of relocation types used by Android
7733 // on ARM v5te devices.
7734
7735 template<bool big_endian>
7736 inline void
7737 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7738 Layout* layout,
7739 Target_arm* target,
7740 Sized_relobj_file<32, big_endian>* object,
7741 unsigned int data_shndx,
7742 Output_section* output_section,
7743 const elfcpp::Rel<32, big_endian>& reloc,
7744 unsigned int r_type,
7745 const elfcpp::Sym<32, big_endian>& lsym)
7746 {
7747 r_type = get_real_reloc_type(r_type);
7748 switch (r_type)
7749 {
7750 case elfcpp::R_ARM_NONE:
7751 case elfcpp::R_ARM_V4BX:
7752 case elfcpp::R_ARM_GNU_VTENTRY:
7753 case elfcpp::R_ARM_GNU_VTINHERIT:
7754 break;
7755
7756 case elfcpp::R_ARM_ABS32:
7757 case elfcpp::R_ARM_ABS32_NOI:
7758 // If building a shared library (or a position-independent
7759 // executable), we need to create a dynamic relocation for
7760 // this location. The relocation applied at link time will
7761 // apply the link-time value, so we flag the location with
7762 // an R_ARM_RELATIVE relocation so the dynamic loader can
7763 // relocate it easily.
7764 if (parameters->options().output_is_position_independent())
7765 {
7766 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7767 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7768 // If we are to add more other reloc types than R_ARM_ABS32,
7769 // we need to add check_non_pic(object, r_type) here.
7770 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7771 output_section, data_shndx,
7772 reloc.get_r_offset());
7773 }
7774 break;
7775
7776 case elfcpp::R_ARM_ABS16:
7777 case elfcpp::R_ARM_ABS12:
7778 case elfcpp::R_ARM_THM_ABS5:
7779 case elfcpp::R_ARM_ABS8:
7780 case elfcpp::R_ARM_BASE_ABS:
7781 case elfcpp::R_ARM_MOVW_ABS_NC:
7782 case elfcpp::R_ARM_MOVT_ABS:
7783 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7784 case elfcpp::R_ARM_THM_MOVT_ABS:
7785 // If building a shared library (or a position-independent
7786 // executable), we need to create a dynamic relocation for
7787 // this location. Because the addend needs to remain in the
7788 // data section, we need to be careful not to apply this
7789 // relocation statically.
7790 if (parameters->options().output_is_position_independent())
7791 {
7792 check_non_pic(object, r_type);
7793 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7794 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7795 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7796 rel_dyn->add_local(object, r_sym, r_type, output_section,
7797 data_shndx, reloc.get_r_offset());
7798 else
7799 {
7800 gold_assert(lsym.get_st_value() == 0);
7801 unsigned int shndx = lsym.get_st_shndx();
7802 bool is_ordinary;
7803 shndx = object->adjust_sym_shndx(r_sym, shndx,
7804 &is_ordinary);
7805 if (!is_ordinary)
7806 object->error(_("section symbol %u has bad shndx %u"),
7807 r_sym, shndx);
7808 else
7809 rel_dyn->add_local_section(object, shndx,
7810 r_type, output_section,
7811 data_shndx, reloc.get_r_offset());
7812 }
7813 }
7814 break;
7815
7816 case elfcpp::R_ARM_REL32:
7817 case elfcpp::R_ARM_LDR_PC_G0:
7818 case elfcpp::R_ARM_SBREL32:
7819 case elfcpp::R_ARM_THM_CALL:
7820 case elfcpp::R_ARM_THM_PC8:
7821 case elfcpp::R_ARM_BASE_PREL:
7822 case elfcpp::R_ARM_PLT32:
7823 case elfcpp::R_ARM_CALL:
7824 case elfcpp::R_ARM_JUMP24:
7825 case elfcpp::R_ARM_THM_JUMP24:
7826 case elfcpp::R_ARM_SBREL31:
7827 case elfcpp::R_ARM_PREL31:
7828 case elfcpp::R_ARM_MOVW_PREL_NC:
7829 case elfcpp::R_ARM_MOVT_PREL:
7830 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7831 case elfcpp::R_ARM_THM_MOVT_PREL:
7832 case elfcpp::R_ARM_THM_JUMP19:
7833 case elfcpp::R_ARM_THM_JUMP6:
7834 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7835 case elfcpp::R_ARM_THM_PC12:
7836 case elfcpp::R_ARM_REL32_NOI:
7837 case elfcpp::R_ARM_ALU_PC_G0_NC:
7838 case elfcpp::R_ARM_ALU_PC_G0:
7839 case elfcpp::R_ARM_ALU_PC_G1_NC:
7840 case elfcpp::R_ARM_ALU_PC_G1:
7841 case elfcpp::R_ARM_ALU_PC_G2:
7842 case elfcpp::R_ARM_LDR_PC_G1:
7843 case elfcpp::R_ARM_LDR_PC_G2:
7844 case elfcpp::R_ARM_LDRS_PC_G0:
7845 case elfcpp::R_ARM_LDRS_PC_G1:
7846 case elfcpp::R_ARM_LDRS_PC_G2:
7847 case elfcpp::R_ARM_LDC_PC_G0:
7848 case elfcpp::R_ARM_LDC_PC_G1:
7849 case elfcpp::R_ARM_LDC_PC_G2:
7850 case elfcpp::R_ARM_ALU_SB_G0_NC:
7851 case elfcpp::R_ARM_ALU_SB_G0:
7852 case elfcpp::R_ARM_ALU_SB_G1_NC:
7853 case elfcpp::R_ARM_ALU_SB_G1:
7854 case elfcpp::R_ARM_ALU_SB_G2:
7855 case elfcpp::R_ARM_LDR_SB_G0:
7856 case elfcpp::R_ARM_LDR_SB_G1:
7857 case elfcpp::R_ARM_LDR_SB_G2:
7858 case elfcpp::R_ARM_LDRS_SB_G0:
7859 case elfcpp::R_ARM_LDRS_SB_G1:
7860 case elfcpp::R_ARM_LDRS_SB_G2:
7861 case elfcpp::R_ARM_LDC_SB_G0:
7862 case elfcpp::R_ARM_LDC_SB_G1:
7863 case elfcpp::R_ARM_LDC_SB_G2:
7864 case elfcpp::R_ARM_MOVW_BREL_NC:
7865 case elfcpp::R_ARM_MOVT_BREL:
7866 case elfcpp::R_ARM_MOVW_BREL:
7867 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7868 case elfcpp::R_ARM_THM_MOVT_BREL:
7869 case elfcpp::R_ARM_THM_MOVW_BREL:
7870 case elfcpp::R_ARM_THM_JUMP11:
7871 case elfcpp::R_ARM_THM_JUMP8:
7872 // We don't need to do anything for a relative addressing relocation
7873 // against a local symbol if it does not reference the GOT.
7874 break;
7875
7876 case elfcpp::R_ARM_GOTOFF32:
7877 case elfcpp::R_ARM_GOTOFF12:
7878 // We need a GOT section:
7879 target->got_section(symtab, layout);
7880 break;
7881
7882 case elfcpp::R_ARM_GOT_BREL:
7883 case elfcpp::R_ARM_GOT_PREL:
7884 {
7885 // The symbol requires a GOT entry.
7886 Arm_output_data_got<big_endian>* got =
7887 target->got_section(symtab, layout);
7888 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7889 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7890 {
7891 // If we are generating a shared object, we need to add a
7892 // dynamic RELATIVE relocation for this symbol's GOT entry.
7893 if (parameters->options().output_is_position_independent())
7894 {
7895 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7896 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7897 rel_dyn->add_local_relative(
7898 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7899 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7900 }
7901 }
7902 }
7903 break;
7904
7905 case elfcpp::R_ARM_TARGET1:
7906 case elfcpp::R_ARM_TARGET2:
7907 // This should have been mapped to another type already.
7908 // Fall through.
7909 case elfcpp::R_ARM_COPY:
7910 case elfcpp::R_ARM_GLOB_DAT:
7911 case elfcpp::R_ARM_JUMP_SLOT:
7912 case elfcpp::R_ARM_RELATIVE:
7913 // These are relocations which should only be seen by the
7914 // dynamic linker, and should never be seen here.
7915 gold_error(_("%s: unexpected reloc %u in object file"),
7916 object->name().c_str(), r_type);
7917 break;
7918
7919
7920 // These are initial TLS relocs, which are expected when
7921 // linking.
7922 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7923 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7924 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7925 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7926 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7927 {
7928 bool output_is_shared = parameters->options().shared();
7929 const tls::Tls_optimization optimized_type
7930 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7931 r_type);
7932 switch (r_type)
7933 {
7934 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7935 if (optimized_type == tls::TLSOPT_NONE)
7936 {
7937 // Create a pair of GOT entries for the module index and
7938 // dtv-relative offset.
7939 Arm_output_data_got<big_endian>* got
7940 = target->got_section(symtab, layout);
7941 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7942 unsigned int shndx = lsym.get_st_shndx();
7943 bool is_ordinary;
7944 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7945 if (!is_ordinary)
7946 {
7947 object->error(_("local symbol %u has bad shndx %u"),
7948 r_sym, shndx);
7949 break;
7950 }
7951
7952 if (!parameters->doing_static_link())
7953 got->add_local_pair_with_rel(object, r_sym, shndx,
7954 GOT_TYPE_TLS_PAIR,
7955 target->rel_dyn_section(layout),
7956 elfcpp::R_ARM_TLS_DTPMOD32, 0);
7957 else
7958 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7959 object, r_sym);
7960 }
7961 else
7962 // FIXME: TLS optimization not supported yet.
7963 gold_unreachable();
7964 break;
7965
7966 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7967 if (optimized_type == tls::TLSOPT_NONE)
7968 {
7969 // Create a GOT entry for the module index.
7970 target->got_mod_index_entry(symtab, layout, object);
7971 }
7972 else
7973 // FIXME: TLS optimization not supported yet.
7974 gold_unreachable();
7975 break;
7976
7977 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7978 break;
7979
7980 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7981 layout->set_has_static_tls();
7982 if (optimized_type == tls::TLSOPT_NONE)
7983 {
7984 // Create a GOT entry for the tp-relative offset.
7985 Arm_output_data_got<big_endian>* got
7986 = target->got_section(symtab, layout);
7987 unsigned int r_sym =
7988 elfcpp::elf_r_sym<32>(reloc.get_r_info());
7989 if (!parameters->doing_static_link())
7990 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7991 target->rel_dyn_section(layout),
7992 elfcpp::R_ARM_TLS_TPOFF32);
7993 else if (!object->local_has_got_offset(r_sym,
7994 GOT_TYPE_TLS_OFFSET))
7995 {
7996 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7997 unsigned int got_offset =
7998 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7999 got->add_static_reloc(got_offset,
8000 elfcpp::R_ARM_TLS_TPOFF32, object,
8001 r_sym);
8002 }
8003 }
8004 else
8005 // FIXME: TLS optimization not supported yet.
8006 gold_unreachable();
8007 break;
8008
8009 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8010 layout->set_has_static_tls();
8011 if (output_is_shared)
8012 {
8013 // We need to create a dynamic relocation.
8014 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8015 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8016 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8017 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8018 output_section, data_shndx,
8019 reloc.get_r_offset());
8020 }
8021 break;
8022
8023 default:
8024 gold_unreachable();
8025 }
8026 }
8027 break;
8028
8029 case elfcpp::R_ARM_PC24:
8030 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8031 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8032 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8033 default:
8034 unsupported_reloc_local(object, r_type);
8035 break;
8036 }
8037 }
8038
8039 // Report an unsupported relocation against a global symbol.
8040
8041 template<bool big_endian>
8042 void
8043 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8044 Sized_relobj_file<32, big_endian>* object,
8045 unsigned int r_type,
8046 Symbol* gsym)
8047 {
8048 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8049 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8050 }
8051
8052 template<bool big_endian>
8053 inline bool
8054 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8055 unsigned int r_type)
8056 {
8057 switch (r_type)
8058 {
8059 case elfcpp::R_ARM_PC24:
8060 case elfcpp::R_ARM_THM_CALL:
8061 case elfcpp::R_ARM_PLT32:
8062 case elfcpp::R_ARM_CALL:
8063 case elfcpp::R_ARM_JUMP24:
8064 case elfcpp::R_ARM_THM_JUMP24:
8065 case elfcpp::R_ARM_SBREL31:
8066 case elfcpp::R_ARM_PREL31:
8067 case elfcpp::R_ARM_THM_JUMP19:
8068 case elfcpp::R_ARM_THM_JUMP6:
8069 case elfcpp::R_ARM_THM_JUMP11:
8070 case elfcpp::R_ARM_THM_JUMP8:
8071 // All the relocations above are branches except SBREL31 and PREL31.
8072 return false;
8073
8074 default:
8075 // Be conservative and assume this is a function pointer.
8076 return true;
8077 }
8078 }
8079
8080 template<bool big_endian>
8081 inline bool
8082 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8083 Symbol_table*,
8084 Layout*,
8085 Target_arm<big_endian>* target,
8086 Sized_relobj_file<32, big_endian>*,
8087 unsigned int,
8088 Output_section*,
8089 const elfcpp::Rel<32, big_endian>&,
8090 unsigned int r_type,
8091 const elfcpp::Sym<32, big_endian>&)
8092 {
8093 r_type = target->get_real_reloc_type(r_type);
8094 return possible_function_pointer_reloc(r_type);
8095 }
8096
8097 template<bool big_endian>
8098 inline bool
8099 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8100 Symbol_table*,
8101 Layout*,
8102 Target_arm<big_endian>* target,
8103 Sized_relobj_file<32, big_endian>*,
8104 unsigned int,
8105 Output_section*,
8106 const elfcpp::Rel<32, big_endian>&,
8107 unsigned int r_type,
8108 Symbol* gsym)
8109 {
8110 // GOT is not a function.
8111 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8112 return false;
8113
8114 r_type = target->get_real_reloc_type(r_type);
8115 return possible_function_pointer_reloc(r_type);
8116 }
8117
8118 // Scan a relocation for a global symbol.
8119
8120 template<bool big_endian>
8121 inline void
8122 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8123 Layout* layout,
8124 Target_arm* target,
8125 Sized_relobj_file<32, big_endian>* object,
8126 unsigned int data_shndx,
8127 Output_section* output_section,
8128 const elfcpp::Rel<32, big_endian>& reloc,
8129 unsigned int r_type,
8130 Symbol* gsym)
8131 {
8132 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8133 // section. We check here to avoid creating a dynamic reloc against
8134 // _GLOBAL_OFFSET_TABLE_.
8135 if (!target->has_got_section()
8136 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8137 target->got_section(symtab, layout);
8138
8139 r_type = get_real_reloc_type(r_type);
8140 switch (r_type)
8141 {
8142 case elfcpp::R_ARM_NONE:
8143 case elfcpp::R_ARM_V4BX:
8144 case elfcpp::R_ARM_GNU_VTENTRY:
8145 case elfcpp::R_ARM_GNU_VTINHERIT:
8146 break;
8147
8148 case elfcpp::R_ARM_ABS32:
8149 case elfcpp::R_ARM_ABS16:
8150 case elfcpp::R_ARM_ABS12:
8151 case elfcpp::R_ARM_THM_ABS5:
8152 case elfcpp::R_ARM_ABS8:
8153 case elfcpp::R_ARM_BASE_ABS:
8154 case elfcpp::R_ARM_MOVW_ABS_NC:
8155 case elfcpp::R_ARM_MOVT_ABS:
8156 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8157 case elfcpp::R_ARM_THM_MOVT_ABS:
8158 case elfcpp::R_ARM_ABS32_NOI:
8159 // Absolute addressing relocations.
8160 {
8161 // Make a PLT entry if necessary.
8162 if (this->symbol_needs_plt_entry(gsym))
8163 {
8164 target->make_plt_entry(symtab, layout, gsym);
8165 // Since this is not a PC-relative relocation, we may be
8166 // taking the address of a function. In that case we need to
8167 // set the entry in the dynamic symbol table to the address of
8168 // the PLT entry.
8169 if (gsym->is_from_dynobj() && !parameters->options().shared())
8170 gsym->set_needs_dynsym_value();
8171 }
8172 // Make a dynamic relocation if necessary.
8173 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8174 {
8175 if (gsym->may_need_copy_reloc())
8176 {
8177 target->copy_reloc(symtab, layout, object,
8178 data_shndx, output_section, gsym, reloc);
8179 }
8180 else if ((r_type == elfcpp::R_ARM_ABS32
8181 || r_type == elfcpp::R_ARM_ABS32_NOI)
8182 && gsym->can_use_relative_reloc(false))
8183 {
8184 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8185 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8186 output_section, object,
8187 data_shndx, reloc.get_r_offset());
8188 }
8189 else
8190 {
8191 check_non_pic(object, r_type);
8192 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8193 rel_dyn->add_global(gsym, r_type, output_section, object,
8194 data_shndx, reloc.get_r_offset());
8195 }
8196 }
8197 }
8198 break;
8199
8200 case elfcpp::R_ARM_GOTOFF32:
8201 case elfcpp::R_ARM_GOTOFF12:
8202 // We need a GOT section.
8203 target->got_section(symtab, layout);
8204 break;
8205
8206 case elfcpp::R_ARM_REL32:
8207 case elfcpp::R_ARM_LDR_PC_G0:
8208 case elfcpp::R_ARM_SBREL32:
8209 case elfcpp::R_ARM_THM_PC8:
8210 case elfcpp::R_ARM_BASE_PREL:
8211 case elfcpp::R_ARM_MOVW_PREL_NC:
8212 case elfcpp::R_ARM_MOVT_PREL:
8213 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8214 case elfcpp::R_ARM_THM_MOVT_PREL:
8215 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8216 case elfcpp::R_ARM_THM_PC12:
8217 case elfcpp::R_ARM_REL32_NOI:
8218 case elfcpp::R_ARM_ALU_PC_G0_NC:
8219 case elfcpp::R_ARM_ALU_PC_G0:
8220 case elfcpp::R_ARM_ALU_PC_G1_NC:
8221 case elfcpp::R_ARM_ALU_PC_G1:
8222 case elfcpp::R_ARM_ALU_PC_G2:
8223 case elfcpp::R_ARM_LDR_PC_G1:
8224 case elfcpp::R_ARM_LDR_PC_G2:
8225 case elfcpp::R_ARM_LDRS_PC_G0:
8226 case elfcpp::R_ARM_LDRS_PC_G1:
8227 case elfcpp::R_ARM_LDRS_PC_G2:
8228 case elfcpp::R_ARM_LDC_PC_G0:
8229 case elfcpp::R_ARM_LDC_PC_G1:
8230 case elfcpp::R_ARM_LDC_PC_G2:
8231 case elfcpp::R_ARM_ALU_SB_G0_NC:
8232 case elfcpp::R_ARM_ALU_SB_G0:
8233 case elfcpp::R_ARM_ALU_SB_G1_NC:
8234 case elfcpp::R_ARM_ALU_SB_G1:
8235 case elfcpp::R_ARM_ALU_SB_G2:
8236 case elfcpp::R_ARM_LDR_SB_G0:
8237 case elfcpp::R_ARM_LDR_SB_G1:
8238 case elfcpp::R_ARM_LDR_SB_G2:
8239 case elfcpp::R_ARM_LDRS_SB_G0:
8240 case elfcpp::R_ARM_LDRS_SB_G1:
8241 case elfcpp::R_ARM_LDRS_SB_G2:
8242 case elfcpp::R_ARM_LDC_SB_G0:
8243 case elfcpp::R_ARM_LDC_SB_G1:
8244 case elfcpp::R_ARM_LDC_SB_G2:
8245 case elfcpp::R_ARM_MOVW_BREL_NC:
8246 case elfcpp::R_ARM_MOVT_BREL:
8247 case elfcpp::R_ARM_MOVW_BREL:
8248 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8249 case elfcpp::R_ARM_THM_MOVT_BREL:
8250 case elfcpp::R_ARM_THM_MOVW_BREL:
8251 // Relative addressing relocations.
8252 {
8253 // Make a dynamic relocation if necessary.
8254 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8255 {
8256 if (target->may_need_copy_reloc(gsym))
8257 {
8258 target->copy_reloc(symtab, layout, object,
8259 data_shndx, output_section, gsym, reloc);
8260 }
8261 else
8262 {
8263 check_non_pic(object, r_type);
8264 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8265 rel_dyn->add_global(gsym, r_type, output_section, object,
8266 data_shndx, reloc.get_r_offset());
8267 }
8268 }
8269 }
8270 break;
8271
8272 case elfcpp::R_ARM_THM_CALL:
8273 case elfcpp::R_ARM_PLT32:
8274 case elfcpp::R_ARM_CALL:
8275 case elfcpp::R_ARM_JUMP24:
8276 case elfcpp::R_ARM_THM_JUMP24:
8277 case elfcpp::R_ARM_SBREL31:
8278 case elfcpp::R_ARM_PREL31:
8279 case elfcpp::R_ARM_THM_JUMP19:
8280 case elfcpp::R_ARM_THM_JUMP6:
8281 case elfcpp::R_ARM_THM_JUMP11:
8282 case elfcpp::R_ARM_THM_JUMP8:
8283 // All the relocation above are branches except for the PREL31 ones.
8284 // A PREL31 relocation can point to a personality function in a shared
8285 // library. In that case we want to use a PLT because we want to
8286 // call the personality routine and the dynamic linkers we care about
8287 // do not support dynamic PREL31 relocations. An REL31 relocation may
8288 // point to a function whose unwinding behaviour is being described but
8289 // we will not mistakenly generate a PLT for that because we should use
8290 // a local section symbol.
8291
8292 // If the symbol is fully resolved, this is just a relative
8293 // local reloc. Otherwise we need a PLT entry.
8294 if (gsym->final_value_is_known())
8295 break;
8296 // If building a shared library, we can also skip the PLT entry
8297 // if the symbol is defined in the output file and is protected
8298 // or hidden.
8299 if (gsym->is_defined()
8300 && !gsym->is_from_dynobj()
8301 && !gsym->is_preemptible())
8302 break;
8303 target->make_plt_entry(symtab, layout, gsym);
8304 break;
8305
8306 case elfcpp::R_ARM_GOT_BREL:
8307 case elfcpp::R_ARM_GOT_ABS:
8308 case elfcpp::R_ARM_GOT_PREL:
8309 {
8310 // The symbol requires a GOT entry.
8311 Arm_output_data_got<big_endian>* got =
8312 target->got_section(symtab, layout);
8313 if (gsym->final_value_is_known())
8314 got->add_global(gsym, GOT_TYPE_STANDARD);
8315 else
8316 {
8317 // If this symbol is not fully resolved, we need to add a
8318 // GOT entry with a dynamic relocation.
8319 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8320 if (gsym->is_from_dynobj()
8321 || gsym->is_undefined()
8322 || gsym->is_preemptible())
8323 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8324 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8325 else
8326 {
8327 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8328 rel_dyn->add_global_relative(
8329 gsym, elfcpp::R_ARM_RELATIVE, got,
8330 gsym->got_offset(GOT_TYPE_STANDARD));
8331 }
8332 }
8333 }
8334 break;
8335
8336 case elfcpp::R_ARM_TARGET1:
8337 case elfcpp::R_ARM_TARGET2:
8338 // These should have been mapped to other types already.
8339 // Fall through.
8340 case elfcpp::R_ARM_COPY:
8341 case elfcpp::R_ARM_GLOB_DAT:
8342 case elfcpp::R_ARM_JUMP_SLOT:
8343 case elfcpp::R_ARM_RELATIVE:
8344 // These are relocations which should only be seen by the
8345 // dynamic linker, and should never be seen here.
8346 gold_error(_("%s: unexpected reloc %u in object file"),
8347 object->name().c_str(), r_type);
8348 break;
8349
8350 // These are initial tls relocs, which are expected when
8351 // linking.
8352 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8353 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8354 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8355 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8356 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8357 {
8358 const bool is_final = gsym->final_value_is_known();
8359 const tls::Tls_optimization optimized_type
8360 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8361 switch (r_type)
8362 {
8363 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8364 if (optimized_type == tls::TLSOPT_NONE)
8365 {
8366 // Create a pair of GOT entries for the module index and
8367 // dtv-relative offset.
8368 Arm_output_data_got<big_endian>* got
8369 = target->got_section(symtab, layout);
8370 if (!parameters->doing_static_link())
8371 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8372 target->rel_dyn_section(layout),
8373 elfcpp::R_ARM_TLS_DTPMOD32,
8374 elfcpp::R_ARM_TLS_DTPOFF32);
8375 else
8376 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8377 }
8378 else
8379 // FIXME: TLS optimization not supported yet.
8380 gold_unreachable();
8381 break;
8382
8383 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8384 if (optimized_type == tls::TLSOPT_NONE)
8385 {
8386 // Create a GOT entry for the module index.
8387 target->got_mod_index_entry(symtab, layout, object);
8388 }
8389 else
8390 // FIXME: TLS optimization not supported yet.
8391 gold_unreachable();
8392 break;
8393
8394 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8395 break;
8396
8397 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8398 layout->set_has_static_tls();
8399 if (optimized_type == tls::TLSOPT_NONE)
8400 {
8401 // Create a GOT entry for the tp-relative offset.
8402 Arm_output_data_got<big_endian>* got
8403 = target->got_section(symtab, layout);
8404 if (!parameters->doing_static_link())
8405 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8406 target->rel_dyn_section(layout),
8407 elfcpp::R_ARM_TLS_TPOFF32);
8408 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8409 {
8410 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8411 unsigned int got_offset =
8412 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8413 got->add_static_reloc(got_offset,
8414 elfcpp::R_ARM_TLS_TPOFF32, gsym);
8415 }
8416 }
8417 else
8418 // FIXME: TLS optimization not supported yet.
8419 gold_unreachable();
8420 break;
8421
8422 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8423 layout->set_has_static_tls();
8424 if (parameters->options().shared())
8425 {
8426 // We need to create a dynamic relocation.
8427 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8428 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8429 output_section, object,
8430 data_shndx, reloc.get_r_offset());
8431 }
8432 break;
8433
8434 default:
8435 gold_unreachable();
8436 }
8437 }
8438 break;
8439
8440 case elfcpp::R_ARM_PC24:
8441 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8442 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8443 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8444 default:
8445 unsupported_reloc_global(object, r_type, gsym);
8446 break;
8447 }
8448 }
8449
8450 // Process relocations for gc.
8451
8452 template<bool big_endian>
8453 void
8454 Target_arm<big_endian>::gc_process_relocs(
8455 Symbol_table* symtab,
8456 Layout* layout,
8457 Sized_relobj_file<32, big_endian>* object,
8458 unsigned int data_shndx,
8459 unsigned int,
8460 const unsigned char* prelocs,
8461 size_t reloc_count,
8462 Output_section* output_section,
8463 bool needs_special_offset_handling,
8464 size_t local_symbol_count,
8465 const unsigned char* plocal_symbols)
8466 {
8467 typedef Target_arm<big_endian> Arm;
8468 typedef typename Target_arm<big_endian>::Scan Scan;
8469
8470 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8471 typename Target_arm::Relocatable_size_for_reloc>(
8472 symtab,
8473 layout,
8474 this,
8475 object,
8476 data_shndx,
8477 prelocs,
8478 reloc_count,
8479 output_section,
8480 needs_special_offset_handling,
8481 local_symbol_count,
8482 plocal_symbols);
8483 }
8484
8485 // Scan relocations for a section.
8486
8487 template<bool big_endian>
8488 void
8489 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8490 Layout* layout,
8491 Sized_relobj_file<32, big_endian>* object,
8492 unsigned int data_shndx,
8493 unsigned int sh_type,
8494 const unsigned char* prelocs,
8495 size_t reloc_count,
8496 Output_section* output_section,
8497 bool needs_special_offset_handling,
8498 size_t local_symbol_count,
8499 const unsigned char* plocal_symbols)
8500 {
8501 typedef typename Target_arm<big_endian>::Scan Scan;
8502 if (sh_type == elfcpp::SHT_RELA)
8503 {
8504 gold_error(_("%s: unsupported RELA reloc section"),
8505 object->name().c_str());
8506 return;
8507 }
8508
8509 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8510 symtab,
8511 layout,
8512 this,
8513 object,
8514 data_shndx,
8515 prelocs,
8516 reloc_count,
8517 output_section,
8518 needs_special_offset_handling,
8519 local_symbol_count,
8520 plocal_symbols);
8521 }
8522
8523 // Finalize the sections.
8524
8525 template<bool big_endian>
8526 void
8527 Target_arm<big_endian>::do_finalize_sections(
8528 Layout* layout,
8529 const Input_objects* input_objects,
8530 Symbol_table* symtab)
8531 {
8532 bool merged_any_attributes = false;
8533 // Merge processor-specific flags.
8534 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8535 p != input_objects->relobj_end();
8536 ++p)
8537 {
8538 Arm_relobj<big_endian>* arm_relobj =
8539 Arm_relobj<big_endian>::as_arm_relobj(*p);
8540 if (arm_relobj->merge_flags_and_attributes())
8541 {
8542 this->merge_processor_specific_flags(
8543 arm_relobj->name(),
8544 arm_relobj->processor_specific_flags());
8545 this->merge_object_attributes(arm_relobj->name().c_str(),
8546 arm_relobj->attributes_section_data());
8547 merged_any_attributes = true;
8548 }
8549 }
8550
8551 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8552 p != input_objects->dynobj_end();
8553 ++p)
8554 {
8555 Arm_dynobj<big_endian>* arm_dynobj =
8556 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8557 this->merge_processor_specific_flags(
8558 arm_dynobj->name(),
8559 arm_dynobj->processor_specific_flags());
8560 this->merge_object_attributes(arm_dynobj->name().c_str(),
8561 arm_dynobj->attributes_section_data());
8562 merged_any_attributes = true;
8563 }
8564
8565 // Create an empty uninitialized attribute section if we still don't have it
8566 // at this moment. This happens if there is no attributes sections in all
8567 // inputs.
8568 if (this->attributes_section_data_ == NULL)
8569 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8570
8571 const Object_attribute* cpu_arch_attr =
8572 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8573 // Check if we need to use Cortex-A8 workaround.
8574 if (parameters->options().user_set_fix_cortex_a8())
8575 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8576 else
8577 {
8578 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8579 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8580 // profile.
8581 const Object_attribute* cpu_arch_profile_attr =
8582 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8583 this->fix_cortex_a8_ =
8584 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8585 && (cpu_arch_profile_attr->int_value() == 'A'
8586 || cpu_arch_profile_attr->int_value() == 0));
8587 }
8588
8589 // Check if we can use V4BX interworking.
8590 // The V4BX interworking stub contains BX instruction,
8591 // which is not specified for some profiles.
8592 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8593 && !this->may_use_v4t_interworking())
8594 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8595 "the target profile does not support BX instruction"));
8596
8597 // Fill in some more dynamic tags.
8598 const Reloc_section* rel_plt = (this->plt_ == NULL
8599 ? NULL
8600 : this->plt_->rel_plt());
8601 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8602 this->rel_dyn_, true, false);
8603
8604 // Emit any relocs we saved in an attempt to avoid generating COPY
8605 // relocs.
8606 if (this->copy_relocs_.any_saved_relocs())
8607 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8608
8609 // Handle the .ARM.exidx section.
8610 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8611
8612 if (!parameters->options().relocatable())
8613 {
8614 if (exidx_section != NULL
8615 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8616 {
8617 // Create __exidx_start and __exidx_end symbols.
8618 symtab->define_in_output_data("__exidx_start", NULL,
8619 Symbol_table::PREDEFINED,
8620 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8621 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8622 0, false, true);
8623 symtab->define_in_output_data("__exidx_end", NULL,
8624 Symbol_table::PREDEFINED,
8625 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8626 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN,
8627 0, true, true);
8628
8629 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8630 // the .ARM.exidx section.
8631 if (!layout->script_options()->saw_phdrs_clause())
8632 {
8633 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8634 0)
8635 == NULL);
8636 Output_segment* exidx_segment =
8637 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8638 exidx_segment->add_output_section_to_nonload(exidx_section,
8639 elfcpp::PF_R);
8640 }
8641 }
8642 else
8643 {
8644 symtab->define_as_constant("__exidx_start", NULL,
8645 Symbol_table::PREDEFINED,
8646 0, 0, elfcpp::STT_OBJECT,
8647 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8648 true, false);
8649 symtab->define_as_constant("__exidx_end", NULL,
8650 Symbol_table::PREDEFINED,
8651 0, 0, elfcpp::STT_OBJECT,
8652 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8653 true, false);
8654 }
8655 }
8656
8657 // Create an .ARM.attributes section if we have merged any attributes
8658 // from inputs.
8659 if (merged_any_attributes)
8660 {
8661 Output_attributes_section_data* attributes_section =
8662 new Output_attributes_section_data(*this->attributes_section_data_);
8663 layout->add_output_section_data(".ARM.attributes",
8664 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8665 attributes_section, ORDER_INVALID,
8666 false);
8667 }
8668
8669 // Fix up links in section EXIDX headers.
8670 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8671 p != layout->section_list().end();
8672 ++p)
8673 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8674 {
8675 Arm_output_section<big_endian>* os =
8676 Arm_output_section<big_endian>::as_arm_output_section(*p);
8677 os->set_exidx_section_link();
8678 }
8679 }
8680
8681 // Return whether a direct absolute static relocation needs to be applied.
8682 // In cases where Scan::local() or Scan::global() has created
8683 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8684 // of the relocation is carried in the data, and we must not
8685 // apply the static relocation.
8686
8687 template<bool big_endian>
8688 inline bool
8689 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8690 const Sized_symbol<32>* gsym,
8691 unsigned int r_type,
8692 bool is_32bit,
8693 Output_section* output_section)
8694 {
8695 // If the output section is not allocated, then we didn't call
8696 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8697 // the reloc here.
8698 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8699 return true;
8700
8701 int ref_flags = Scan::get_reference_flags(r_type);
8702
8703 // For local symbols, we will have created a non-RELATIVE dynamic
8704 // relocation only if (a) the output is position independent,
8705 // (b) the relocation is absolute (not pc- or segment-relative), and
8706 // (c) the relocation is not 32 bits wide.
8707 if (gsym == NULL)
8708 return !(parameters->options().output_is_position_independent()
8709 && (ref_flags & Symbol::ABSOLUTE_REF)
8710 && !is_32bit);
8711
8712 // For global symbols, we use the same helper routines used in the
8713 // scan pass. If we did not create a dynamic relocation, or if we
8714 // created a RELATIVE dynamic relocation, we should apply the static
8715 // relocation.
8716 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8717 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8718 && gsym->can_use_relative_reloc(ref_flags
8719 & Symbol::FUNCTION_CALL);
8720 return !has_dyn || is_rel;
8721 }
8722
8723 // Perform a relocation.
8724
8725 template<bool big_endian>
8726 inline bool
8727 Target_arm<big_endian>::Relocate::relocate(
8728 const Relocate_info<32, big_endian>* relinfo,
8729 Target_arm* target,
8730 Output_section* output_section,
8731 size_t relnum,
8732 const elfcpp::Rel<32, big_endian>& rel,
8733 unsigned int r_type,
8734 const Sized_symbol<32>* gsym,
8735 const Symbol_value<32>* psymval,
8736 unsigned char* view,
8737 Arm_address address,
8738 section_size_type view_size)
8739 {
8740 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8741
8742 r_type = get_real_reloc_type(r_type);
8743 const Arm_reloc_property* reloc_property =
8744 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8745 if (reloc_property == NULL)
8746 {
8747 std::string reloc_name =
8748 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8749 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8750 _("cannot relocate %s in object file"),
8751 reloc_name.c_str());
8752 return true;
8753 }
8754
8755 const Arm_relobj<big_endian>* object =
8756 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8757
8758 // If the final branch target of a relocation is THUMB instruction, this
8759 // is 1. Otherwise it is 0.
8760 Arm_address thumb_bit = 0;
8761 Symbol_value<32> symval;
8762 bool is_weakly_undefined_without_plt = false;
8763 bool have_got_offset = false;
8764 unsigned int got_offset = 0;
8765
8766 // If the relocation uses the GOT entry of a symbol instead of the symbol
8767 // itself, we don't care about whether the symbol is defined or what kind
8768 // of symbol it is.
8769 if (reloc_property->uses_got_entry())
8770 {
8771 // Get the GOT offset.
8772 // The GOT pointer points to the end of the GOT section.
8773 // We need to subtract the size of the GOT section to get
8774 // the actual offset to use in the relocation.
8775 // TODO: We should move GOT offset computing code in TLS relocations
8776 // to here.
8777 switch (r_type)
8778 {
8779 case elfcpp::R_ARM_GOT_BREL:
8780 case elfcpp::R_ARM_GOT_PREL:
8781 if (gsym != NULL)
8782 {
8783 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8784 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8785 - target->got_size());
8786 }
8787 else
8788 {
8789 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8790 gold_assert(object->local_has_got_offset(r_sym,
8791 GOT_TYPE_STANDARD));
8792 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8793 - target->got_size());
8794 }
8795 have_got_offset = true;
8796 break;
8797
8798 default:
8799 break;
8800 }
8801 }
8802 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8803 {
8804 if (gsym != NULL)
8805 {
8806 // This is a global symbol. Determine if we use PLT and if the
8807 // final target is THUMB.
8808 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8809 {
8810 // This uses a PLT, change the symbol value.
8811 symval.set_output_value(target->plt_section()->address()
8812 + gsym->plt_offset());
8813 psymval = &symval;
8814 }
8815 else if (gsym->is_weak_undefined())
8816 {
8817 // This is a weakly undefined symbol and we do not use PLT
8818 // for this relocation. A branch targeting this symbol will
8819 // be converted into an NOP.
8820 is_weakly_undefined_without_plt = true;
8821 }
8822 else if (gsym->is_undefined() && reloc_property->uses_symbol())
8823 {
8824 // This relocation uses the symbol value but the symbol is
8825 // undefined. Exit early and have the caller reporting an
8826 // error.
8827 return true;
8828 }
8829 else
8830 {
8831 // Set thumb bit if symbol:
8832 // -Has type STT_ARM_TFUNC or
8833 // -Has type STT_FUNC, is defined and with LSB in value set.
8834 thumb_bit =
8835 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8836 || (gsym->type() == elfcpp::STT_FUNC
8837 && !gsym->is_undefined()
8838 && ((psymval->value(object, 0) & 1) != 0)))
8839 ? 1
8840 : 0);
8841 }
8842 }
8843 else
8844 {
8845 // This is a local symbol. Determine if the final target is THUMB.
8846 // We saved this information when all the local symbols were read.
8847 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8848 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8849 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8850 }
8851 }
8852 else
8853 {
8854 // This is a fake relocation synthesized for a stub. It does not have
8855 // a real symbol. We just look at the LSB of the symbol value to
8856 // determine if the target is THUMB or not.
8857 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8858 }
8859
8860 // Strip LSB if this points to a THUMB target.
8861 if (thumb_bit != 0
8862 && reloc_property->uses_thumb_bit()
8863 && ((psymval->value(object, 0) & 1) != 0))
8864 {
8865 Arm_address stripped_value =
8866 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8867 symval.set_output_value(stripped_value);
8868 psymval = &symval;
8869 }
8870
8871 // To look up relocation stubs, we need to pass the symbol table index of
8872 // a local symbol.
8873 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8874
8875 // Get the addressing origin of the output segment defining the
8876 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8877 Arm_address sym_origin = 0;
8878 if (reloc_property->uses_symbol_base())
8879 {
8880 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8881 // R_ARM_BASE_ABS with the NULL symbol will give the
8882 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8883 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8884 sym_origin = target->got_plt_section()->address();
8885 else if (gsym == NULL)
8886 sym_origin = 0;
8887 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8888 sym_origin = gsym->output_segment()->vaddr();
8889 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8890 sym_origin = gsym->output_data()->address();
8891
8892 // TODO: Assumes the segment base to be zero for the global symbols
8893 // till the proper support for the segment-base-relative addressing
8894 // will be implemented. This is consistent with GNU ld.
8895 }
8896
8897 // For relative addressing relocation, find out the relative address base.
8898 Arm_address relative_address_base = 0;
8899 switch(reloc_property->relative_address_base())
8900 {
8901 case Arm_reloc_property::RAB_NONE:
8902 // Relocations with relative address bases RAB_TLS and RAB_tp are
8903 // handled by relocate_tls. So we do not need to do anything here.
8904 case Arm_reloc_property::RAB_TLS:
8905 case Arm_reloc_property::RAB_tp:
8906 break;
8907 case Arm_reloc_property::RAB_B_S:
8908 relative_address_base = sym_origin;
8909 break;
8910 case Arm_reloc_property::RAB_GOT_ORG:
8911 relative_address_base = target->got_plt_section()->address();
8912 break;
8913 case Arm_reloc_property::RAB_P:
8914 relative_address_base = address;
8915 break;
8916 case Arm_reloc_property::RAB_Pa:
8917 relative_address_base = address & 0xfffffffcU;
8918 break;
8919 default:
8920 gold_unreachable();
8921 }
8922
8923 typename Arm_relocate_functions::Status reloc_status =
8924 Arm_relocate_functions::STATUS_OKAY;
8925 bool check_overflow = reloc_property->checks_overflow();
8926 switch (r_type)
8927 {
8928 case elfcpp::R_ARM_NONE:
8929 break;
8930
8931 case elfcpp::R_ARM_ABS8:
8932 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8933 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8934 break;
8935
8936 case elfcpp::R_ARM_ABS12:
8937 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8938 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8939 break;
8940
8941 case elfcpp::R_ARM_ABS16:
8942 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8943 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8944 break;
8945
8946 case elfcpp::R_ARM_ABS32:
8947 if (should_apply_static_reloc(gsym, r_type, true, output_section))
8948 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8949 thumb_bit);
8950 break;
8951
8952 case elfcpp::R_ARM_ABS32_NOI:
8953 if (should_apply_static_reloc(gsym, r_type, true, output_section))
8954 // No thumb bit for this relocation: (S + A)
8955 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8956 0);
8957 break;
8958
8959 case elfcpp::R_ARM_MOVW_ABS_NC:
8960 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8961 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8962 0, thumb_bit,
8963 check_overflow);
8964 break;
8965
8966 case elfcpp::R_ARM_MOVT_ABS:
8967 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8968 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8969 break;
8970
8971 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8972 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8973 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8974 0, thumb_bit, false);
8975 break;
8976
8977 case elfcpp::R_ARM_THM_MOVT_ABS:
8978 if (should_apply_static_reloc(gsym, r_type, false, output_section))
8979 reloc_status = Arm_relocate_functions::thm_movt(view, object,
8980 psymval, 0);
8981 break;
8982
8983 case elfcpp::R_ARM_MOVW_PREL_NC:
8984 case elfcpp::R_ARM_MOVW_BREL_NC:
8985 case elfcpp::R_ARM_MOVW_BREL:
8986 reloc_status =
8987 Arm_relocate_functions::movw(view, object, psymval,
8988 relative_address_base, thumb_bit,
8989 check_overflow);
8990 break;
8991
8992 case elfcpp::R_ARM_MOVT_PREL:
8993 case elfcpp::R_ARM_MOVT_BREL:
8994 reloc_status =
8995 Arm_relocate_functions::movt(view, object, psymval,
8996 relative_address_base);
8997 break;
8998
8999 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9000 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9001 case elfcpp::R_ARM_THM_MOVW_BREL:
9002 reloc_status =
9003 Arm_relocate_functions::thm_movw(view, object, psymval,
9004 relative_address_base,
9005 thumb_bit, check_overflow);
9006 break;
9007
9008 case elfcpp::R_ARM_THM_MOVT_PREL:
9009 case elfcpp::R_ARM_THM_MOVT_BREL:
9010 reloc_status =
9011 Arm_relocate_functions::thm_movt(view, object, psymval,
9012 relative_address_base);
9013 break;
9014
9015 case elfcpp::R_ARM_REL32:
9016 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9017 address, thumb_bit);
9018 break;
9019
9020 case elfcpp::R_ARM_THM_ABS5:
9021 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9022 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9023 break;
9024
9025 // Thumb long branches.
9026 case elfcpp::R_ARM_THM_CALL:
9027 case elfcpp::R_ARM_THM_XPC22:
9028 case elfcpp::R_ARM_THM_JUMP24:
9029 reloc_status =
9030 Arm_relocate_functions::thumb_branch_common(
9031 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9032 thumb_bit, is_weakly_undefined_without_plt);
9033 break;
9034
9035 case elfcpp::R_ARM_GOTOFF32:
9036 {
9037 Arm_address got_origin;
9038 got_origin = target->got_plt_section()->address();
9039 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9040 got_origin, thumb_bit);
9041 }
9042 break;
9043
9044 case elfcpp::R_ARM_BASE_PREL:
9045 gold_assert(gsym != NULL);
9046 reloc_status =
9047 Arm_relocate_functions::base_prel(view, sym_origin, address);
9048 break;
9049
9050 case elfcpp::R_ARM_BASE_ABS:
9051 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9052 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9053 break;
9054
9055 case elfcpp::R_ARM_GOT_BREL:
9056 gold_assert(have_got_offset);
9057 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9058 break;
9059
9060 case elfcpp::R_ARM_GOT_PREL:
9061 gold_assert(have_got_offset);
9062 // Get the address origin for GOT PLT, which is allocated right
9063 // after the GOT section, to calculate an absolute address of
9064 // the symbol GOT entry (got_origin + got_offset).
9065 Arm_address got_origin;
9066 got_origin = target->got_plt_section()->address();
9067 reloc_status = Arm_relocate_functions::got_prel(view,
9068 got_origin + got_offset,
9069 address);
9070 break;
9071
9072 case elfcpp::R_ARM_PLT32:
9073 case elfcpp::R_ARM_CALL:
9074 case elfcpp::R_ARM_JUMP24:
9075 case elfcpp::R_ARM_XPC25:
9076 gold_assert(gsym == NULL
9077 || gsym->has_plt_offset()
9078 || gsym->final_value_is_known()
9079 || (gsym->is_defined()
9080 && !gsym->is_from_dynobj()
9081 && !gsym->is_preemptible()));
9082 reloc_status =
9083 Arm_relocate_functions::arm_branch_common(
9084 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9085 thumb_bit, is_weakly_undefined_without_plt);
9086 break;
9087
9088 case elfcpp::R_ARM_THM_JUMP19:
9089 reloc_status =
9090 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9091 thumb_bit);
9092 break;
9093
9094 case elfcpp::R_ARM_THM_JUMP6:
9095 reloc_status =
9096 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9097 break;
9098
9099 case elfcpp::R_ARM_THM_JUMP8:
9100 reloc_status =
9101 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9102 break;
9103
9104 case elfcpp::R_ARM_THM_JUMP11:
9105 reloc_status =
9106 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9107 break;
9108
9109 case elfcpp::R_ARM_PREL31:
9110 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9111 address, thumb_bit);
9112 break;
9113
9114 case elfcpp::R_ARM_V4BX:
9115 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9116 {
9117 const bool is_v4bx_interworking =
9118 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9119 reloc_status =
9120 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9121 is_v4bx_interworking);
9122 }
9123 break;
9124
9125 case elfcpp::R_ARM_THM_PC8:
9126 reloc_status =
9127 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9128 break;
9129
9130 case elfcpp::R_ARM_THM_PC12:
9131 reloc_status =
9132 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9133 break;
9134
9135 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9136 reloc_status =
9137 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9138 thumb_bit);
9139 break;
9140
9141 case elfcpp::R_ARM_ALU_PC_G0_NC:
9142 case elfcpp::R_ARM_ALU_PC_G0:
9143 case elfcpp::R_ARM_ALU_PC_G1_NC:
9144 case elfcpp::R_ARM_ALU_PC_G1:
9145 case elfcpp::R_ARM_ALU_PC_G2:
9146 case elfcpp::R_ARM_ALU_SB_G0_NC:
9147 case elfcpp::R_ARM_ALU_SB_G0:
9148 case elfcpp::R_ARM_ALU_SB_G1_NC:
9149 case elfcpp::R_ARM_ALU_SB_G1:
9150 case elfcpp::R_ARM_ALU_SB_G2:
9151 reloc_status =
9152 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9153 reloc_property->group_index(),
9154 relative_address_base,
9155 thumb_bit, check_overflow);
9156 break;
9157
9158 case elfcpp::R_ARM_LDR_PC_G0:
9159 case elfcpp::R_ARM_LDR_PC_G1:
9160 case elfcpp::R_ARM_LDR_PC_G2:
9161 case elfcpp::R_ARM_LDR_SB_G0:
9162 case elfcpp::R_ARM_LDR_SB_G1:
9163 case elfcpp::R_ARM_LDR_SB_G2:
9164 reloc_status =
9165 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9166 reloc_property->group_index(),
9167 relative_address_base);
9168 break;
9169
9170 case elfcpp::R_ARM_LDRS_PC_G0:
9171 case elfcpp::R_ARM_LDRS_PC_G1:
9172 case elfcpp::R_ARM_LDRS_PC_G2:
9173 case elfcpp::R_ARM_LDRS_SB_G0:
9174 case elfcpp::R_ARM_LDRS_SB_G1:
9175 case elfcpp::R_ARM_LDRS_SB_G2:
9176 reloc_status =
9177 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9178 reloc_property->group_index(),
9179 relative_address_base);
9180 break;
9181
9182 case elfcpp::R_ARM_LDC_PC_G0:
9183 case elfcpp::R_ARM_LDC_PC_G1:
9184 case elfcpp::R_ARM_LDC_PC_G2:
9185 case elfcpp::R_ARM_LDC_SB_G0:
9186 case elfcpp::R_ARM_LDC_SB_G1:
9187 case elfcpp::R_ARM_LDC_SB_G2:
9188 reloc_status =
9189 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9190 reloc_property->group_index(),
9191 relative_address_base);
9192 break;
9193
9194 // These are initial tls relocs, which are expected when
9195 // linking.
9196 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9197 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9198 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9199 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9200 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9201 reloc_status =
9202 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9203 view, address, view_size);
9204 break;
9205
9206 // The known and unknown unsupported and/or deprecated relocations.
9207 case elfcpp::R_ARM_PC24:
9208 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9209 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9210 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9211 default:
9212 // Just silently leave the method. We should get an appropriate error
9213 // message in the scan methods.
9214 break;
9215 }
9216
9217 // Report any errors.
9218 switch (reloc_status)
9219 {
9220 case Arm_relocate_functions::STATUS_OKAY:
9221 break;
9222 case Arm_relocate_functions::STATUS_OVERFLOW:
9223 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9224 _("relocation overflow in %s"),
9225 reloc_property->name().c_str());
9226 break;
9227 case Arm_relocate_functions::STATUS_BAD_RELOC:
9228 gold_error_at_location(
9229 relinfo,
9230 relnum,
9231 rel.get_r_offset(),
9232 _("unexpected opcode while processing relocation %s"),
9233 reloc_property->name().c_str());
9234 break;
9235 default:
9236 gold_unreachable();
9237 }
9238
9239 return true;
9240 }
9241
9242 // Perform a TLS relocation.
9243
9244 template<bool big_endian>
9245 inline typename Arm_relocate_functions<big_endian>::Status
9246 Target_arm<big_endian>::Relocate::relocate_tls(
9247 const Relocate_info<32, big_endian>* relinfo,
9248 Target_arm<big_endian>* target,
9249 size_t relnum,
9250 const elfcpp::Rel<32, big_endian>& rel,
9251 unsigned int r_type,
9252 const Sized_symbol<32>* gsym,
9253 const Symbol_value<32>* psymval,
9254 unsigned char* view,
9255 elfcpp::Elf_types<32>::Elf_Addr address,
9256 section_size_type /*view_size*/ )
9257 {
9258 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9259 typedef Relocate_functions<32, big_endian> RelocFuncs;
9260 Output_segment* tls_segment = relinfo->layout->tls_segment();
9261
9262 const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9263
9264 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9265
9266 const bool is_final = (gsym == NULL
9267 ? !parameters->options().shared()
9268 : gsym->final_value_is_known());
9269 const tls::Tls_optimization optimized_type
9270 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9271 switch (r_type)
9272 {
9273 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9274 {
9275 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9276 unsigned int got_offset;
9277 if (gsym != NULL)
9278 {
9279 gold_assert(gsym->has_got_offset(got_type));
9280 got_offset = gsym->got_offset(got_type) - target->got_size();
9281 }
9282 else
9283 {
9284 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9285 gold_assert(object->local_has_got_offset(r_sym, got_type));
9286 got_offset = (object->local_got_offset(r_sym, got_type)
9287 - target->got_size());
9288 }
9289 if (optimized_type == tls::TLSOPT_NONE)
9290 {
9291 Arm_address got_entry =
9292 target->got_plt_section()->address() + got_offset;
9293
9294 // Relocate the field with the PC relative offset of the pair of
9295 // GOT entries.
9296 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9297 return ArmRelocFuncs::STATUS_OKAY;
9298 }
9299 }
9300 break;
9301
9302 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9303 if (optimized_type == tls::TLSOPT_NONE)
9304 {
9305 // Relocate the field with the offset of the GOT entry for
9306 // the module index.
9307 unsigned int got_offset;
9308 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9309 - target->got_size());
9310 Arm_address got_entry =
9311 target->got_plt_section()->address() + got_offset;
9312
9313 // Relocate the field with the PC relative offset of the pair of
9314 // GOT entries.
9315 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9316 return ArmRelocFuncs::STATUS_OKAY;
9317 }
9318 break;
9319
9320 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9321 RelocFuncs::rel32_unaligned(view, value);
9322 return ArmRelocFuncs::STATUS_OKAY;
9323
9324 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9325 if (optimized_type == tls::TLSOPT_NONE)
9326 {
9327 // Relocate the field with the offset of the GOT entry for
9328 // the tp-relative offset of the symbol.
9329 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9330 unsigned int got_offset;
9331 if (gsym != NULL)
9332 {
9333 gold_assert(gsym->has_got_offset(got_type));
9334 got_offset = gsym->got_offset(got_type);
9335 }
9336 else
9337 {
9338 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9339 gold_assert(object->local_has_got_offset(r_sym, got_type));
9340 got_offset = object->local_got_offset(r_sym, got_type);
9341 }
9342
9343 // All GOT offsets are relative to the end of the GOT.
9344 got_offset -= target->got_size();
9345
9346 Arm_address got_entry =
9347 target->got_plt_section()->address() + got_offset;
9348
9349 // Relocate the field with the PC relative offset of the GOT entry.
9350 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9351 return ArmRelocFuncs::STATUS_OKAY;
9352 }
9353 break;
9354
9355 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9356 // If we're creating a shared library, a dynamic relocation will
9357 // have been created for this location, so do not apply it now.
9358 if (!parameters->options().shared())
9359 {
9360 gold_assert(tls_segment != NULL);
9361
9362 // $tp points to the TCB, which is followed by the TLS, so we
9363 // need to add TCB size to the offset.
9364 Arm_address aligned_tcb_size =
9365 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9366 RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9367
9368 }
9369 return ArmRelocFuncs::STATUS_OKAY;
9370
9371 default:
9372 gold_unreachable();
9373 }
9374
9375 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9376 _("unsupported reloc %u"),
9377 r_type);
9378 return ArmRelocFuncs::STATUS_BAD_RELOC;
9379 }
9380
9381 // Relocate section data.
9382
9383 template<bool big_endian>
9384 void
9385 Target_arm<big_endian>::relocate_section(
9386 const Relocate_info<32, big_endian>* relinfo,
9387 unsigned int sh_type,
9388 const unsigned char* prelocs,
9389 size_t reloc_count,
9390 Output_section* output_section,
9391 bool needs_special_offset_handling,
9392 unsigned char* view,
9393 Arm_address address,
9394 section_size_type view_size,
9395 const Reloc_symbol_changes* reloc_symbol_changes)
9396 {
9397 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9398 gold_assert(sh_type == elfcpp::SHT_REL);
9399
9400 // See if we are relocating a relaxed input section. If so, the view
9401 // covers the whole output section and we need to adjust accordingly.
9402 if (needs_special_offset_handling)
9403 {
9404 const Output_relaxed_input_section* poris =
9405 output_section->find_relaxed_input_section(relinfo->object,
9406 relinfo->data_shndx);
9407 if (poris != NULL)
9408 {
9409 Arm_address section_address = poris->address();
9410 section_size_type section_size = poris->data_size();
9411
9412 gold_assert((section_address >= address)
9413 && ((section_address + section_size)
9414 <= (address + view_size)));
9415
9416 off_t offset = section_address - address;
9417 view += offset;
9418 address += offset;
9419 view_size = section_size;
9420 }
9421 }
9422
9423 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9424 Arm_relocate>(
9425 relinfo,
9426 this,
9427 prelocs,
9428 reloc_count,
9429 output_section,
9430 needs_special_offset_handling,
9431 view,
9432 address,
9433 view_size,
9434 reloc_symbol_changes);
9435 }
9436
9437 // Return the size of a relocation while scanning during a relocatable
9438 // link.
9439
9440 template<bool big_endian>
9441 unsigned int
9442 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9443 unsigned int r_type,
9444 Relobj* object)
9445 {
9446 r_type = get_real_reloc_type(r_type);
9447 const Arm_reloc_property* arp =
9448 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9449 if (arp != NULL)
9450 return arp->size();
9451 else
9452 {
9453 std::string reloc_name =
9454 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9455 gold_error(_("%s: unexpected %s in object file"),
9456 object->name().c_str(), reloc_name.c_str());
9457 return 0;
9458 }
9459 }
9460
9461 // Scan the relocs during a relocatable link.
9462
9463 template<bool big_endian>
9464 void
9465 Target_arm<big_endian>::scan_relocatable_relocs(
9466 Symbol_table* symtab,
9467 Layout* layout,
9468 Sized_relobj_file<32, big_endian>* object,
9469 unsigned int data_shndx,
9470 unsigned int sh_type,
9471 const unsigned char* prelocs,
9472 size_t reloc_count,
9473 Output_section* output_section,
9474 bool needs_special_offset_handling,
9475 size_t local_symbol_count,
9476 const unsigned char* plocal_symbols,
9477 Relocatable_relocs* rr)
9478 {
9479 gold_assert(sh_type == elfcpp::SHT_REL);
9480
9481 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9482 Relocatable_size_for_reloc> Scan_relocatable_relocs;
9483
9484 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9485 Scan_relocatable_relocs>(
9486 symtab,
9487 layout,
9488 object,
9489 data_shndx,
9490 prelocs,
9491 reloc_count,
9492 output_section,
9493 needs_special_offset_handling,
9494 local_symbol_count,
9495 plocal_symbols,
9496 rr);
9497 }
9498
9499 // Relocate a section during a relocatable link.
9500
9501 template<bool big_endian>
9502 void
9503 Target_arm<big_endian>::relocate_for_relocatable(
9504 const Relocate_info<32, big_endian>* relinfo,
9505 unsigned int sh_type,
9506 const unsigned char* prelocs,
9507 size_t reloc_count,
9508 Output_section* output_section,
9509 off_t offset_in_output_section,
9510 const Relocatable_relocs* rr,
9511 unsigned char* view,
9512 Arm_address view_address,
9513 section_size_type view_size,
9514 unsigned char* reloc_view,
9515 section_size_type reloc_view_size)
9516 {
9517 gold_assert(sh_type == elfcpp::SHT_REL);
9518
9519 gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
9520 relinfo,
9521 prelocs,
9522 reloc_count,
9523 output_section,
9524 offset_in_output_section,
9525 rr,
9526 view,
9527 view_address,
9528 view_size,
9529 reloc_view,
9530 reloc_view_size);
9531 }
9532
9533 // Perform target-specific processing in a relocatable link. This is
9534 // only used if we use the relocation strategy RELOC_SPECIAL.
9535
9536 template<bool big_endian>
9537 void
9538 Target_arm<big_endian>::relocate_special_relocatable(
9539 const Relocate_info<32, big_endian>* relinfo,
9540 unsigned int sh_type,
9541 const unsigned char* preloc_in,
9542 size_t relnum,
9543 Output_section* output_section,
9544 off_t offset_in_output_section,
9545 unsigned char* view,
9546 elfcpp::Elf_types<32>::Elf_Addr view_address,
9547 section_size_type,
9548 unsigned char* preloc_out)
9549 {
9550 // We can only handle REL type relocation sections.
9551 gold_assert(sh_type == elfcpp::SHT_REL);
9552
9553 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9554 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9555 Reltype_write;
9556 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9557
9558 const Arm_relobj<big_endian>* object =
9559 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9560 const unsigned int local_count = object->local_symbol_count();
9561
9562 Reltype reloc(preloc_in);
9563 Reltype_write reloc_write(preloc_out);
9564
9565 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9566 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9567 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9568
9569 const Arm_reloc_property* arp =
9570 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9571 gold_assert(arp != NULL);
9572
9573 // Get the new symbol index.
9574 // We only use RELOC_SPECIAL strategy in local relocations.
9575 gold_assert(r_sym < local_count);
9576
9577 // We are adjusting a section symbol. We need to find
9578 // the symbol table index of the section symbol for
9579 // the output section corresponding to input section
9580 // in which this symbol is defined.
9581 bool is_ordinary;
9582 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9583 gold_assert(is_ordinary);
9584 Output_section* os = object->output_section(shndx);
9585 gold_assert(os != NULL);
9586 gold_assert(os->needs_symtab_index());
9587 unsigned int new_symndx = os->symtab_index();
9588
9589 // Get the new offset--the location in the output section where
9590 // this relocation should be applied.
9591
9592 Arm_address offset = reloc.get_r_offset();
9593 Arm_address new_offset;
9594 if (offset_in_output_section != invalid_address)
9595 new_offset = offset + offset_in_output_section;
9596 else
9597 {
9598 section_offset_type sot_offset =
9599 convert_types<section_offset_type, Arm_address>(offset);
9600 section_offset_type new_sot_offset =
9601 output_section->output_offset(object, relinfo->data_shndx,
9602 sot_offset);
9603 gold_assert(new_sot_offset != -1);
9604 new_offset = new_sot_offset;
9605 }
9606
9607 // In an object file, r_offset is an offset within the section.
9608 // In an executable or dynamic object, generated by
9609 // --emit-relocs, r_offset is an absolute address.
9610 if (!parameters->options().relocatable())
9611 {
9612 new_offset += view_address;
9613 if (offset_in_output_section != invalid_address)
9614 new_offset -= offset_in_output_section;
9615 }
9616
9617 reloc_write.put_r_offset(new_offset);
9618 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9619
9620 // Handle the reloc addend.
9621 // The relocation uses a section symbol in the input file.
9622 // We are adjusting it to use a section symbol in the output
9623 // file. The input section symbol refers to some address in
9624 // the input section. We need the relocation in the output
9625 // file to refer to that same address. This adjustment to
9626 // the addend is the same calculation we use for a simple
9627 // absolute relocation for the input section symbol.
9628
9629 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9630
9631 // Handle THUMB bit.
9632 Symbol_value<32> symval;
9633 Arm_address thumb_bit =
9634 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9635 if (thumb_bit != 0
9636 && arp->uses_thumb_bit()
9637 && ((psymval->value(object, 0) & 1) != 0))
9638 {
9639 Arm_address stripped_value =
9640 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9641 symval.set_output_value(stripped_value);
9642 psymval = &symval;
9643 }
9644
9645 unsigned char* paddend = view + offset;
9646 typename Arm_relocate_functions<big_endian>::Status reloc_status =
9647 Arm_relocate_functions<big_endian>::STATUS_OKAY;
9648 switch (r_type)
9649 {
9650 case elfcpp::R_ARM_ABS8:
9651 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9652 psymval);
9653 break;
9654
9655 case elfcpp::R_ARM_ABS12:
9656 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9657 psymval);
9658 break;
9659
9660 case elfcpp::R_ARM_ABS16:
9661 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9662 psymval);
9663 break;
9664
9665 case elfcpp::R_ARM_THM_ABS5:
9666 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9667 object,
9668 psymval);
9669 break;
9670
9671 case elfcpp::R_ARM_MOVW_ABS_NC:
9672 case elfcpp::R_ARM_MOVW_PREL_NC:
9673 case elfcpp::R_ARM_MOVW_BREL_NC:
9674 case elfcpp::R_ARM_MOVW_BREL:
9675 reloc_status = Arm_relocate_functions<big_endian>::movw(
9676 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9677 break;
9678
9679 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9680 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9681 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9682 case elfcpp::R_ARM_THM_MOVW_BREL:
9683 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9684 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9685 break;
9686
9687 case elfcpp::R_ARM_THM_CALL:
9688 case elfcpp::R_ARM_THM_XPC22:
9689 case elfcpp::R_ARM_THM_JUMP24:
9690 reloc_status =
9691 Arm_relocate_functions<big_endian>::thumb_branch_common(
9692 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9693 false);
9694 break;
9695
9696 case elfcpp::R_ARM_PLT32:
9697 case elfcpp::R_ARM_CALL:
9698 case elfcpp::R_ARM_JUMP24:
9699 case elfcpp::R_ARM_XPC25:
9700 reloc_status =
9701 Arm_relocate_functions<big_endian>::arm_branch_common(
9702 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9703 false);
9704 break;
9705
9706 case elfcpp::R_ARM_THM_JUMP19:
9707 reloc_status =
9708 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9709 psymval, 0, thumb_bit);
9710 break;
9711
9712 case elfcpp::R_ARM_THM_JUMP6:
9713 reloc_status =
9714 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9715 0);
9716 break;
9717
9718 case elfcpp::R_ARM_THM_JUMP8:
9719 reloc_status =
9720 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9721 0);
9722 break;
9723
9724 case elfcpp::R_ARM_THM_JUMP11:
9725 reloc_status =
9726 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9727 0);
9728 break;
9729
9730 case elfcpp::R_ARM_PREL31:
9731 reloc_status =
9732 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9733 thumb_bit);
9734 break;
9735
9736 case elfcpp::R_ARM_THM_PC8:
9737 reloc_status =
9738 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9739 0);
9740 break;
9741
9742 case elfcpp::R_ARM_THM_PC12:
9743 reloc_status =
9744 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9745 0);
9746 break;
9747
9748 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9749 reloc_status =
9750 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9751 0, thumb_bit);
9752 break;
9753
9754 // These relocation truncate relocation results so we cannot handle them
9755 // in a relocatable link.
9756 case elfcpp::R_ARM_MOVT_ABS:
9757 case elfcpp::R_ARM_THM_MOVT_ABS:
9758 case elfcpp::R_ARM_MOVT_PREL:
9759 case elfcpp::R_ARM_MOVT_BREL:
9760 case elfcpp::R_ARM_THM_MOVT_PREL:
9761 case elfcpp::R_ARM_THM_MOVT_BREL:
9762 case elfcpp::R_ARM_ALU_PC_G0_NC:
9763 case elfcpp::R_ARM_ALU_PC_G0:
9764 case elfcpp::R_ARM_ALU_PC_G1_NC:
9765 case elfcpp::R_ARM_ALU_PC_G1:
9766 case elfcpp::R_ARM_ALU_PC_G2:
9767 case elfcpp::R_ARM_ALU_SB_G0_NC:
9768 case elfcpp::R_ARM_ALU_SB_G0:
9769 case elfcpp::R_ARM_ALU_SB_G1_NC:
9770 case elfcpp::R_ARM_ALU_SB_G1:
9771 case elfcpp::R_ARM_ALU_SB_G2:
9772 case elfcpp::R_ARM_LDR_PC_G0:
9773 case elfcpp::R_ARM_LDR_PC_G1:
9774 case elfcpp::R_ARM_LDR_PC_G2:
9775 case elfcpp::R_ARM_LDR_SB_G0:
9776 case elfcpp::R_ARM_LDR_SB_G1:
9777 case elfcpp::R_ARM_LDR_SB_G2:
9778 case elfcpp::R_ARM_LDRS_PC_G0:
9779 case elfcpp::R_ARM_LDRS_PC_G1:
9780 case elfcpp::R_ARM_LDRS_PC_G2:
9781 case elfcpp::R_ARM_LDRS_SB_G0:
9782 case elfcpp::R_ARM_LDRS_SB_G1:
9783 case elfcpp::R_ARM_LDRS_SB_G2:
9784 case elfcpp::R_ARM_LDC_PC_G0:
9785 case elfcpp::R_ARM_LDC_PC_G1:
9786 case elfcpp::R_ARM_LDC_PC_G2:
9787 case elfcpp::R_ARM_LDC_SB_G0:
9788 case elfcpp::R_ARM_LDC_SB_G1:
9789 case elfcpp::R_ARM_LDC_SB_G2:
9790 gold_error(_("cannot handle %s in a relocatable link"),
9791 arp->name().c_str());
9792 break;
9793
9794 default:
9795 gold_unreachable();
9796 }
9797
9798 // Report any errors.
9799 switch (reloc_status)
9800 {
9801 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9802 break;
9803 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9804 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9805 _("relocation overflow in %s"),
9806 arp->name().c_str());
9807 break;
9808 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9809 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9810 _("unexpected opcode while processing relocation %s"),
9811 arp->name().c_str());
9812 break;
9813 default:
9814 gold_unreachable();
9815 }
9816 }
9817
9818 // Return the value to use for a dynamic symbol which requires special
9819 // treatment. This is how we support equality comparisons of function
9820 // pointers across shared library boundaries, as described in the
9821 // processor specific ABI supplement.
9822
9823 template<bool big_endian>
9824 uint64_t
9825 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9826 {
9827 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9828 return this->plt_section()->address() + gsym->plt_offset();
9829 }
9830
9831 // Map platform-specific relocs to real relocs
9832 //
9833 template<bool big_endian>
9834 unsigned int
9835 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9836 {
9837 switch (r_type)
9838 {
9839 case elfcpp::R_ARM_TARGET1:
9840 // This is either R_ARM_ABS32 or R_ARM_REL32;
9841 return elfcpp::R_ARM_ABS32;
9842
9843 case elfcpp::R_ARM_TARGET2:
9844 // This can be any reloc type but usually is R_ARM_GOT_PREL
9845 return elfcpp::R_ARM_GOT_PREL;
9846
9847 default:
9848 return r_type;
9849 }
9850 }
9851
9852 // Whether if two EABI versions V1 and V2 are compatible.
9853
9854 template<bool big_endian>
9855 bool
9856 Target_arm<big_endian>::are_eabi_versions_compatible(
9857 elfcpp::Elf_Word v1,
9858 elfcpp::Elf_Word v2)
9859 {
9860 // v4 and v5 are the same spec before and after it was released,
9861 // so allow mixing them.
9862 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9863 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9864 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9865 return true;
9866
9867 return v1 == v2;
9868 }
9869
9870 // Combine FLAGS from an input object called NAME and the processor-specific
9871 // flags in the ELF header of the output. Much of this is adapted from the
9872 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9873 // in bfd/elf32-arm.c.
9874
9875 template<bool big_endian>
9876 void
9877 Target_arm<big_endian>::merge_processor_specific_flags(
9878 const std::string& name,
9879 elfcpp::Elf_Word flags)
9880 {
9881 if (this->are_processor_specific_flags_set())
9882 {
9883 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9884
9885 // Nothing to merge if flags equal to those in output.
9886 if (flags == out_flags)
9887 return;
9888
9889 // Complain about various flag mismatches.
9890 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9891 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9892 if (!this->are_eabi_versions_compatible(version1, version2)
9893 && parameters->options().warn_mismatch())
9894 gold_error(_("Source object %s has EABI version %d but output has "
9895 "EABI version %d."),
9896 name.c_str(),
9897 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9898 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9899 }
9900 else
9901 {
9902 // If the input is the default architecture and had the default
9903 // flags then do not bother setting the flags for the output
9904 // architecture, instead allow future merges to do this. If no
9905 // future merges ever set these flags then they will retain their
9906 // uninitialised values, which surprise surprise, correspond
9907 // to the default values.
9908 if (flags == 0)
9909 return;
9910
9911 // This is the first time, just copy the flags.
9912 // We only copy the EABI version for now.
9913 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
9914 }
9915 }
9916
9917 // Adjust ELF file header.
9918 template<bool big_endian>
9919 void
9920 Target_arm<big_endian>::do_adjust_elf_header(
9921 unsigned char* view,
9922 int len) const
9923 {
9924 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
9925
9926 elfcpp::Ehdr<32, big_endian> ehdr(view);
9927 unsigned char e_ident[elfcpp::EI_NIDENT];
9928 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
9929
9930 if (elfcpp::arm_eabi_version(this->processor_specific_flags())
9931 == elfcpp::EF_ARM_EABI_UNKNOWN)
9932 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
9933 else
9934 e_ident[elfcpp::EI_OSABI] = 0;
9935 e_ident[elfcpp::EI_ABIVERSION] = 0;
9936
9937 // FIXME: Do EF_ARM_BE8 adjustment.
9938
9939 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9940 oehdr.put_e_ident(e_ident);
9941 }
9942
9943 // do_make_elf_object to override the same function in the base class.
9944 // We need to use a target-specific sub-class of
9945 // Sized_relobj_file<32, big_endian> to store ARM specific information.
9946 // Hence we need to have our own ELF object creation.
9947
9948 template<bool big_endian>
9949 Object*
9950 Target_arm<big_endian>::do_make_elf_object(
9951 const std::string& name,
9952 Input_file* input_file,
9953 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9954 {
9955 int et = ehdr.get_e_type();
9956 // ET_EXEC files are valid input for --just-symbols/-R,
9957 // and we treat them as relocatable objects.
9958 if (et == elfcpp::ET_REL
9959 || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
9960 {
9961 Arm_relobj<big_endian>* obj =
9962 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9963 obj->setup();
9964 return obj;
9965 }
9966 else if (et == elfcpp::ET_DYN)
9967 {
9968 Sized_dynobj<32, big_endian>* obj =
9969 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9970 obj->setup();
9971 return obj;
9972 }
9973 else
9974 {
9975 gold_error(_("%s: unsupported ELF file type %d"),
9976 name.c_str(), et);
9977 return NULL;
9978 }
9979 }
9980
9981 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9982 // Returns -1 if no architecture could be read.
9983 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9984
9985 template<bool big_endian>
9986 int
9987 Target_arm<big_endian>::get_secondary_compatible_arch(
9988 const Attributes_section_data* pasd)
9989 {
9990 const Object_attribute* known_attributes =
9991 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9992
9993 // Note: the tag and its argument below are uleb128 values, though
9994 // currently-defined values fit in one byte for each.
9995 const std::string& sv =
9996 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9997 if (sv.size() == 2
9998 && sv.data()[0] == elfcpp::Tag_CPU_arch
9999 && (sv.data()[1] & 128) != 128)
10000 return sv.data()[1];
10001
10002 // This tag is "safely ignorable", so don't complain if it looks funny.
10003 return -1;
10004 }
10005
10006 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10007 // The tag is removed if ARCH is -1.
10008 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10009
10010 template<bool big_endian>
10011 void
10012 Target_arm<big_endian>::set_secondary_compatible_arch(
10013 Attributes_section_data* pasd,
10014 int arch)
10015 {
10016 Object_attribute* known_attributes =
10017 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10018
10019 if (arch == -1)
10020 {
10021 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10022 return;
10023 }
10024
10025 // Note: the tag and its argument below are uleb128 values, though
10026 // currently-defined values fit in one byte for each.
10027 char sv[3];
10028 sv[0] = elfcpp::Tag_CPU_arch;
10029 gold_assert(arch != 0);
10030 sv[1] = arch;
10031 sv[2] = '\0';
10032
10033 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10034 }
10035
10036 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10037 // into account.
10038 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10039
10040 template<bool big_endian>
10041 int
10042 Target_arm<big_endian>::tag_cpu_arch_combine(
10043 const char* name,
10044 int oldtag,
10045 int* secondary_compat_out,
10046 int newtag,
10047 int secondary_compat)
10048 {
10049 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10050 static const int v6t2[] =
10051 {
10052 T(V6T2), // PRE_V4.
10053 T(V6T2), // V4.
10054 T(V6T2), // V4T.
10055 T(V6T2), // V5T.
10056 T(V6T2), // V5TE.
10057 T(V6T2), // V5TEJ.
10058 T(V6T2), // V6.
10059 T(V7), // V6KZ.
10060 T(V6T2) // V6T2.
10061 };
10062 static const int v6k[] =
10063 {
10064 T(V6K), // PRE_V4.
10065 T(V6K), // V4.
10066 T(V6K), // V4T.
10067 T(V6K), // V5T.
10068 T(V6K), // V5TE.
10069 T(V6K), // V5TEJ.
10070 T(V6K), // V6.
10071 T(V6KZ), // V6KZ.
10072 T(V7), // V6T2.
10073 T(V6K) // V6K.
10074 };
10075 static const int v7[] =
10076 {
10077 T(V7), // PRE_V4.
10078 T(V7), // V4.
10079 T(V7), // V4T.
10080 T(V7), // V5T.
10081 T(V7), // V5TE.
10082 T(V7), // V5TEJ.
10083 T(V7), // V6.
10084 T(V7), // V6KZ.
10085 T(V7), // V6T2.
10086 T(V7), // V6K.
10087 T(V7) // V7.
10088 };
10089 static const int v6_m[] =
10090 {
10091 -1, // PRE_V4.
10092 -1, // V4.
10093 T(V6K), // V4T.
10094 T(V6K), // V5T.
10095 T(V6K), // V5TE.
10096 T(V6K), // V5TEJ.
10097 T(V6K), // V6.
10098 T(V6KZ), // V6KZ.
10099 T(V7), // V6T2.
10100 T(V6K), // V6K.
10101 T(V7), // V7.
10102 T(V6_M) // V6_M.
10103 };
10104 static const int v6s_m[] =
10105 {
10106 -1, // PRE_V4.
10107 -1, // V4.
10108 T(V6K), // V4T.
10109 T(V6K), // V5T.
10110 T(V6K), // V5TE.
10111 T(V6K), // V5TEJ.
10112 T(V6K), // V6.
10113 T(V6KZ), // V6KZ.
10114 T(V7), // V6T2.
10115 T(V6K), // V6K.
10116 T(V7), // V7.
10117 T(V6S_M), // V6_M.
10118 T(V6S_M) // V6S_M.
10119 };
10120 static const int v7e_m[] =
10121 {
10122 -1, // PRE_V4.
10123 -1, // V4.
10124 T(V7E_M), // V4T.
10125 T(V7E_M), // V5T.
10126 T(V7E_M), // V5TE.
10127 T(V7E_M), // V5TEJ.
10128 T(V7E_M), // V6.
10129 T(V7E_M), // V6KZ.
10130 T(V7E_M), // V6T2.
10131 T(V7E_M), // V6K.
10132 T(V7E_M), // V7.
10133 T(V7E_M), // V6_M.
10134 T(V7E_M), // V6S_M.
10135 T(V7E_M) // V7E_M.
10136 };
10137 static const int v4t_plus_v6_m[] =
10138 {
10139 -1, // PRE_V4.
10140 -1, // V4.
10141 T(V4T), // V4T.
10142 T(V5T), // V5T.
10143 T(V5TE), // V5TE.
10144 T(V5TEJ), // V5TEJ.
10145 T(V6), // V6.
10146 T(V6KZ), // V6KZ.
10147 T(V6T2), // V6T2.
10148 T(V6K), // V6K.
10149 T(V7), // V7.
10150 T(V6_M), // V6_M.
10151 T(V6S_M), // V6S_M.
10152 T(V7E_M), // V7E_M.
10153 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10154 };
10155 static const int* comb[] =
10156 {
10157 v6t2,
10158 v6k,
10159 v7,
10160 v6_m,
10161 v6s_m,
10162 v7e_m,
10163 // Pseudo-architecture.
10164 v4t_plus_v6_m
10165 };
10166
10167 // Check we've not got a higher architecture than we know about.
10168
10169 if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10170 {
10171 gold_error(_("%s: unknown CPU architecture"), name);
10172 return -1;
10173 }
10174
10175 // Override old tag if we have a Tag_also_compatible_with on the output.
10176
10177 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10178 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10179 oldtag = T(V4T_PLUS_V6_M);
10180
10181 // And override the new tag if we have a Tag_also_compatible_with on the
10182 // input.
10183
10184 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10185 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10186 newtag = T(V4T_PLUS_V6_M);
10187
10188 // Architectures before V6KZ add features monotonically.
10189 int tagh = std::max(oldtag, newtag);
10190 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10191 return tagh;
10192
10193 int tagl = std::min(oldtag, newtag);
10194 int result = comb[tagh - T(V6T2)][tagl];
10195
10196 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10197 // as the canonical version.
10198 if (result == T(V4T_PLUS_V6_M))
10199 {
10200 result = T(V4T);
10201 *secondary_compat_out = T(V6_M);
10202 }
10203 else
10204 *secondary_compat_out = -1;
10205
10206 if (result == -1)
10207 {
10208 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10209 name, oldtag, newtag);
10210 return -1;
10211 }
10212
10213 return result;
10214 #undef T
10215 }
10216
10217 // Helper to print AEABI enum tag value.
10218
10219 template<bool big_endian>
10220 std::string
10221 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10222 {
10223 static const char* aeabi_enum_names[] =
10224 { "", "variable-size", "32-bit", "" };
10225 const size_t aeabi_enum_names_size =
10226 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10227
10228 if (value < aeabi_enum_names_size)
10229 return std::string(aeabi_enum_names[value]);
10230 else
10231 {
10232 char buffer[100];
10233 sprintf(buffer, "<unknown value %u>", value);
10234 return std::string(buffer);
10235 }
10236 }
10237
10238 // Return the string value to store in TAG_CPU_name.
10239
10240 template<bool big_endian>
10241 std::string
10242 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10243 {
10244 static const char* name_table[] = {
10245 // These aren't real CPU names, but we can't guess
10246 // that from the architecture version alone.
10247 "Pre v4",
10248 "ARM v4",
10249 "ARM v4T",
10250 "ARM v5T",
10251 "ARM v5TE",
10252 "ARM v5TEJ",
10253 "ARM v6",
10254 "ARM v6KZ",
10255 "ARM v6T2",
10256 "ARM v6K",
10257 "ARM v7",
10258 "ARM v6-M",
10259 "ARM v6S-M",
10260 "ARM v7E-M"
10261 };
10262 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10263
10264 if (value < name_table_size)
10265 return std::string(name_table[value]);
10266 else
10267 {
10268 char buffer[100];
10269 sprintf(buffer, "<unknown CPU value %u>", value);
10270 return std::string(buffer);
10271 }
10272 }
10273
10274 // Merge object attributes from input file called NAME with those of the
10275 // output. The input object attributes are in the object pointed by PASD.
10276
10277 template<bool big_endian>
10278 void
10279 Target_arm<big_endian>::merge_object_attributes(
10280 const char* name,
10281 const Attributes_section_data* pasd)
10282 {
10283 // Return if there is no attributes section data.
10284 if (pasd == NULL)
10285 return;
10286
10287 // If output has no object attributes, just copy.
10288 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10289 if (this->attributes_section_data_ == NULL)
10290 {
10291 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10292 Object_attribute* out_attr =
10293 this->attributes_section_data_->known_attributes(vendor);
10294
10295 // We do not output objects with Tag_MPextension_use_legacy - we move
10296 // the attribute's value to Tag_MPextension_use. */
10297 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10298 {
10299 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10300 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10301 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10302 {
10303 gold_error(_("%s has both the current and legacy "
10304 "Tag_MPextension_use attributes"),
10305 name);
10306 }
10307
10308 out_attr[elfcpp::Tag_MPextension_use] =
10309 out_attr[elfcpp::Tag_MPextension_use_legacy];
10310 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10311 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10312 }
10313
10314 return;
10315 }
10316
10317 const Object_attribute* in_attr = pasd->known_attributes(vendor);
10318 Object_attribute* out_attr =
10319 this->attributes_section_data_->known_attributes(vendor);
10320
10321 // This needs to happen before Tag_ABI_FP_number_model is merged. */
10322 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10323 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10324 {
10325 // Ignore mismatches if the object doesn't use floating point. */
10326 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10327 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10328 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10329 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10330 && parameters->options().warn_mismatch())
10331 gold_error(_("%s uses VFP register arguments, output does not"),
10332 name);
10333 }
10334
10335 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10336 {
10337 // Merge this attribute with existing attributes.
10338 switch (i)
10339 {
10340 case elfcpp::Tag_CPU_raw_name:
10341 case elfcpp::Tag_CPU_name:
10342 // These are merged after Tag_CPU_arch.
10343 break;
10344
10345 case elfcpp::Tag_ABI_optimization_goals:
10346 case elfcpp::Tag_ABI_FP_optimization_goals:
10347 // Use the first value seen.
10348 break;
10349
10350 case elfcpp::Tag_CPU_arch:
10351 {
10352 unsigned int saved_out_attr = out_attr->int_value();
10353 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10354 int secondary_compat =
10355 this->get_secondary_compatible_arch(pasd);
10356 int secondary_compat_out =
10357 this->get_secondary_compatible_arch(
10358 this->attributes_section_data_);
10359 out_attr[i].set_int_value(
10360 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10361 &secondary_compat_out,
10362 in_attr[i].int_value(),
10363 secondary_compat));
10364 this->set_secondary_compatible_arch(this->attributes_section_data_,
10365 secondary_compat_out);
10366
10367 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10368 if (out_attr[i].int_value() == saved_out_attr)
10369 ; // Leave the names alone.
10370 else if (out_attr[i].int_value() == in_attr[i].int_value())
10371 {
10372 // The output architecture has been changed to match the
10373 // input architecture. Use the input names.
10374 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10375 in_attr[elfcpp::Tag_CPU_name].string_value());
10376 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10377 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10378 }
10379 else
10380 {
10381 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10382 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10383 }
10384
10385 // If we still don't have a value for Tag_CPU_name,
10386 // make one up now. Tag_CPU_raw_name remains blank.
10387 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10388 {
10389 const std::string cpu_name =
10390 this->tag_cpu_name_value(out_attr[i].int_value());
10391 // FIXME: If we see an unknown CPU, this will be set
10392 // to "<unknown CPU n>", where n is the attribute value.
10393 // This is different from BFD, which leaves the name alone.
10394 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10395 }
10396 }
10397 break;
10398
10399 case elfcpp::Tag_ARM_ISA_use:
10400 case elfcpp::Tag_THUMB_ISA_use:
10401 case elfcpp::Tag_WMMX_arch:
10402 case elfcpp::Tag_Advanced_SIMD_arch:
10403 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10404 case elfcpp::Tag_ABI_FP_rounding:
10405 case elfcpp::Tag_ABI_FP_exceptions:
10406 case elfcpp::Tag_ABI_FP_user_exceptions:
10407 case elfcpp::Tag_ABI_FP_number_model:
10408 case elfcpp::Tag_VFP_HP_extension:
10409 case elfcpp::Tag_CPU_unaligned_access:
10410 case elfcpp::Tag_T2EE_use:
10411 case elfcpp::Tag_Virtualization_use:
10412 case elfcpp::Tag_MPextension_use:
10413 // Use the largest value specified.
10414 if (in_attr[i].int_value() > out_attr[i].int_value())
10415 out_attr[i].set_int_value(in_attr[i].int_value());
10416 break;
10417
10418 case elfcpp::Tag_ABI_align8_preserved:
10419 case elfcpp::Tag_ABI_PCS_RO_data:
10420 // Use the smallest value specified.
10421 if (in_attr[i].int_value() < out_attr[i].int_value())
10422 out_attr[i].set_int_value(in_attr[i].int_value());
10423 break;
10424
10425 case elfcpp::Tag_ABI_align8_needed:
10426 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10427 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10428 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10429 == 0)))
10430 {
10431 // This error message should be enabled once all non-conforming
10432 // binaries in the toolchain have had the attributes set
10433 // properly.
10434 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10435 // name);
10436 }
10437 // Fall through.
10438 case elfcpp::Tag_ABI_FP_denormal:
10439 case elfcpp::Tag_ABI_PCS_GOT_use:
10440 {
10441 // These tags have 0 = don't care, 1 = strong requirement,
10442 // 2 = weak requirement.
10443 static const int order_021[3] = {0, 2, 1};
10444
10445 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10446 // value if greater than 2 (for future-proofing).
10447 if ((in_attr[i].int_value() > 2
10448 && in_attr[i].int_value() > out_attr[i].int_value())
10449 || (in_attr[i].int_value() <= 2
10450 && out_attr[i].int_value() <= 2
10451 && (order_021[in_attr[i].int_value()]
10452 > order_021[out_attr[i].int_value()])))
10453 out_attr[i].set_int_value(in_attr[i].int_value());
10454 }
10455 break;
10456
10457 case elfcpp::Tag_CPU_arch_profile:
10458 if (out_attr[i].int_value() != in_attr[i].int_value())
10459 {
10460 // 0 will merge with anything.
10461 // 'A' and 'S' merge to 'A'.
10462 // 'R' and 'S' merge to 'R'.
10463 // 'M' and 'A|R|S' is an error.
10464 if (out_attr[i].int_value() == 0
10465 || (out_attr[i].int_value() == 'S'
10466 && (in_attr[i].int_value() == 'A'
10467 || in_attr[i].int_value() == 'R')))
10468 out_attr[i].set_int_value(in_attr[i].int_value());
10469 else if (in_attr[i].int_value() == 0
10470 || (in_attr[i].int_value() == 'S'
10471 && (out_attr[i].int_value() == 'A'
10472 || out_attr[i].int_value() == 'R')))
10473 ; // Do nothing.
10474 else if (parameters->options().warn_mismatch())
10475 {
10476 gold_error
10477 (_("conflicting architecture profiles %c/%c"),
10478 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10479 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10480 }
10481 }
10482 break;
10483 case elfcpp::Tag_VFP_arch:
10484 {
10485 static const struct
10486 {
10487 int ver;
10488 int regs;
10489 } vfp_versions[7] =
10490 {
10491 {0, 0},
10492 {1, 16},
10493 {2, 16},
10494 {3, 32},
10495 {3, 16},
10496 {4, 32},
10497 {4, 16}
10498 };
10499
10500 // Values greater than 6 aren't defined, so just pick the
10501 // biggest.
10502 if (in_attr[i].int_value() > 6
10503 && in_attr[i].int_value() > out_attr[i].int_value())
10504 {
10505 *out_attr = *in_attr;
10506 break;
10507 }
10508 // The output uses the superset of input features
10509 // (ISA version) and registers.
10510 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10511 vfp_versions[out_attr[i].int_value()].ver);
10512 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10513 vfp_versions[out_attr[i].int_value()].regs);
10514 // This assumes all possible supersets are also a valid
10515 // options.
10516 int newval;
10517 for (newval = 6; newval > 0; newval--)
10518 {
10519 if (regs == vfp_versions[newval].regs
10520 && ver == vfp_versions[newval].ver)
10521 break;
10522 }
10523 out_attr[i].set_int_value(newval);
10524 }
10525 break;
10526 case elfcpp::Tag_PCS_config:
10527 if (out_attr[i].int_value() == 0)
10528 out_attr[i].set_int_value(in_attr[i].int_value());
10529 else if (in_attr[i].int_value() != 0
10530 && out_attr[i].int_value() != 0
10531 && parameters->options().warn_mismatch())
10532 {
10533 // It's sometimes ok to mix different configs, so this is only
10534 // a warning.
10535 gold_warning(_("%s: conflicting platform configuration"), name);
10536 }
10537 break;
10538 case elfcpp::Tag_ABI_PCS_R9_use:
10539 if (in_attr[i].int_value() != out_attr[i].int_value()
10540 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10541 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10542 && parameters->options().warn_mismatch())
10543 {
10544 gold_error(_("%s: conflicting use of R9"), name);
10545 }
10546 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10547 out_attr[i].set_int_value(in_attr[i].int_value());
10548 break;
10549 case elfcpp::Tag_ABI_PCS_RW_data:
10550 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10551 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10552 != elfcpp::AEABI_R9_SB)
10553 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10554 != elfcpp::AEABI_R9_unused)
10555 && parameters->options().warn_mismatch())
10556 {
10557 gold_error(_("%s: SB relative addressing conflicts with use "
10558 "of R9"),
10559 name);
10560 }
10561 // Use the smallest value specified.
10562 if (in_attr[i].int_value() < out_attr[i].int_value())
10563 out_attr[i].set_int_value(in_attr[i].int_value());
10564 break;
10565 case elfcpp::Tag_ABI_PCS_wchar_t:
10566 if (out_attr[i].int_value()
10567 && in_attr[i].int_value()
10568 && out_attr[i].int_value() != in_attr[i].int_value()
10569 && parameters->options().warn_mismatch()
10570 && parameters->options().wchar_size_warning())
10571 {
10572 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10573 "use %u-byte wchar_t; use of wchar_t values "
10574 "across objects may fail"),
10575 name, in_attr[i].int_value(),
10576 out_attr[i].int_value());
10577 }
10578 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10579 out_attr[i].set_int_value(in_attr[i].int_value());
10580 break;
10581 case elfcpp::Tag_ABI_enum_size:
10582 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10583 {
10584 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10585 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10586 {
10587 // The existing object is compatible with anything.
10588 // Use whatever requirements the new object has.
10589 out_attr[i].set_int_value(in_attr[i].int_value());
10590 }
10591 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10592 && out_attr[i].int_value() != in_attr[i].int_value()
10593 && parameters->options().warn_mismatch()
10594 && parameters->options().enum_size_warning())
10595 {
10596 unsigned int in_value = in_attr[i].int_value();
10597 unsigned int out_value = out_attr[i].int_value();
10598 gold_warning(_("%s uses %s enums yet the output is to use "
10599 "%s enums; use of enum values across objects "
10600 "may fail"),
10601 name,
10602 this->aeabi_enum_name(in_value).c_str(),
10603 this->aeabi_enum_name(out_value).c_str());
10604 }
10605 }
10606 break;
10607 case elfcpp::Tag_ABI_VFP_args:
10608 // Already done.
10609 break;
10610 case elfcpp::Tag_ABI_WMMX_args:
10611 if (in_attr[i].int_value() != out_attr[i].int_value()
10612 && parameters->options().warn_mismatch())
10613 {
10614 gold_error(_("%s uses iWMMXt register arguments, output does "
10615 "not"),
10616 name);
10617 }
10618 break;
10619 case Object_attribute::Tag_compatibility:
10620 // Merged in target-independent code.
10621 break;
10622 case elfcpp::Tag_ABI_HardFP_use:
10623 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10624 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10625 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10626 out_attr[i].set_int_value(3);
10627 else if (in_attr[i].int_value() > out_attr[i].int_value())
10628 out_attr[i].set_int_value(in_attr[i].int_value());
10629 break;
10630 case elfcpp::Tag_ABI_FP_16bit_format:
10631 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10632 {
10633 if (in_attr[i].int_value() != out_attr[i].int_value()
10634 && parameters->options().warn_mismatch())
10635 gold_error(_("fp16 format mismatch between %s and output"),
10636 name);
10637 }
10638 if (in_attr[i].int_value() != 0)
10639 out_attr[i].set_int_value(in_attr[i].int_value());
10640 break;
10641
10642 case elfcpp::Tag_DIV_use:
10643 // This tag is set to zero if we can use UDIV and SDIV in Thumb
10644 // mode on a v7-M or v7-R CPU; to one if we can not use UDIV or
10645 // SDIV at all; and to two if we can use UDIV or SDIV on a v7-A
10646 // CPU. We will merge as follows: If the input attribute's value
10647 // is one then the output attribute's value remains unchanged. If
10648 // the input attribute's value is zero or two then if the output
10649 // attribute's value is one the output value is set to the input
10650 // value, otherwise the output value must be the same as the
10651 // inputs. */
10652 if (in_attr[i].int_value() != 1 && out_attr[i].int_value() != 1)
10653 {
10654 if (in_attr[i].int_value() != out_attr[i].int_value())
10655 {
10656 gold_error(_("DIV usage mismatch between %s and output"),
10657 name);
10658 }
10659 }
10660
10661 if (in_attr[i].int_value() != 1)
10662 out_attr[i].set_int_value(in_attr[i].int_value());
10663
10664 break;
10665
10666 case elfcpp::Tag_MPextension_use_legacy:
10667 // We don't output objects with Tag_MPextension_use_legacy - we
10668 // move the value to Tag_MPextension_use.
10669 if (in_attr[i].int_value() != 0
10670 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10671 {
10672 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10673 != in_attr[i].int_value())
10674 {
10675 gold_error(_("%s has has both the current and legacy "
10676 "Tag_MPextension_use attributes"),
10677 name);
10678 }
10679 }
10680
10681 if (in_attr[i].int_value()
10682 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10683 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10684
10685 break;
10686
10687 case elfcpp::Tag_nodefaults:
10688 // This tag is set if it exists, but the value is unused (and is
10689 // typically zero). We don't actually need to do anything here -
10690 // the merge happens automatically when the type flags are merged
10691 // below.
10692 break;
10693 case elfcpp::Tag_also_compatible_with:
10694 // Already done in Tag_CPU_arch.
10695 break;
10696 case elfcpp::Tag_conformance:
10697 // Keep the attribute if it matches. Throw it away otherwise.
10698 // No attribute means no claim to conform.
10699 if (in_attr[i].string_value() != out_attr[i].string_value())
10700 out_attr[i].set_string_value("");
10701 break;
10702
10703 default:
10704 {
10705 const char* err_object = NULL;
10706
10707 // The "known_obj_attributes" table does contain some undefined
10708 // attributes. Ensure that there are unused.
10709 if (out_attr[i].int_value() != 0
10710 || out_attr[i].string_value() != "")
10711 err_object = "output";
10712 else if (in_attr[i].int_value() != 0
10713 || in_attr[i].string_value() != "")
10714 err_object = name;
10715
10716 if (err_object != NULL
10717 && parameters->options().warn_mismatch())
10718 {
10719 // Attribute numbers >=64 (mod 128) can be safely ignored.
10720 if ((i & 127) < 64)
10721 gold_error(_("%s: unknown mandatory EABI object attribute "
10722 "%d"),
10723 err_object, i);
10724 else
10725 gold_warning(_("%s: unknown EABI object attribute %d"),
10726 err_object, i);
10727 }
10728
10729 // Only pass on attributes that match in both inputs.
10730 if (!in_attr[i].matches(out_attr[i]))
10731 {
10732 out_attr[i].set_int_value(0);
10733 out_attr[i].set_string_value("");
10734 }
10735 }
10736 }
10737
10738 // If out_attr was copied from in_attr then it won't have a type yet.
10739 if (in_attr[i].type() && !out_attr[i].type())
10740 out_attr[i].set_type(in_attr[i].type());
10741 }
10742
10743 // Merge Tag_compatibility attributes and any common GNU ones.
10744 this->attributes_section_data_->merge(name, pasd);
10745
10746 // Check for any attributes not known on ARM.
10747 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10748 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10749 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10750 Other_attributes* out_other_attributes =
10751 this->attributes_section_data_->other_attributes(vendor);
10752 Other_attributes::iterator out_iter = out_other_attributes->begin();
10753
10754 while (in_iter != in_other_attributes->end()
10755 || out_iter != out_other_attributes->end())
10756 {
10757 const char* err_object = NULL;
10758 int err_tag = 0;
10759
10760 // The tags for each list are in numerical order.
10761 // If the tags are equal, then merge.
10762 if (out_iter != out_other_attributes->end()
10763 && (in_iter == in_other_attributes->end()
10764 || in_iter->first > out_iter->first))
10765 {
10766 // This attribute only exists in output. We can't merge, and we
10767 // don't know what the tag means, so delete it.
10768 err_object = "output";
10769 err_tag = out_iter->first;
10770 int saved_tag = out_iter->first;
10771 delete out_iter->second;
10772 out_other_attributes->erase(out_iter);
10773 out_iter = out_other_attributes->upper_bound(saved_tag);
10774 }
10775 else if (in_iter != in_other_attributes->end()
10776 && (out_iter != out_other_attributes->end()
10777 || in_iter->first < out_iter->first))
10778 {
10779 // This attribute only exists in input. We can't merge, and we
10780 // don't know what the tag means, so ignore it.
10781 err_object = name;
10782 err_tag = in_iter->first;
10783 ++in_iter;
10784 }
10785 else // The tags are equal.
10786 {
10787 // As present, all attributes in the list are unknown, and
10788 // therefore can't be merged meaningfully.
10789 err_object = "output";
10790 err_tag = out_iter->first;
10791
10792 // Only pass on attributes that match in both inputs.
10793 if (!in_iter->second->matches(*(out_iter->second)))
10794 {
10795 // No match. Delete the attribute.
10796 int saved_tag = out_iter->first;
10797 delete out_iter->second;
10798 out_other_attributes->erase(out_iter);
10799 out_iter = out_other_attributes->upper_bound(saved_tag);
10800 }
10801 else
10802 {
10803 // Matched. Keep the attribute and move to the next.
10804 ++out_iter;
10805 ++in_iter;
10806 }
10807 }
10808
10809 if (err_object && parameters->options().warn_mismatch())
10810 {
10811 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10812 if ((err_tag & 127) < 64)
10813 {
10814 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10815 err_object, err_tag);
10816 }
10817 else
10818 {
10819 gold_warning(_("%s: unknown EABI object attribute %d"),
10820 err_object, err_tag);
10821 }
10822 }
10823 }
10824 }
10825
10826 // Stub-generation methods for Target_arm.
10827
10828 // Make a new Arm_input_section object.
10829
10830 template<bool big_endian>
10831 Arm_input_section<big_endian>*
10832 Target_arm<big_endian>::new_arm_input_section(
10833 Relobj* relobj,
10834 unsigned int shndx)
10835 {
10836 Section_id sid(relobj, shndx);
10837
10838 Arm_input_section<big_endian>* arm_input_section =
10839 new Arm_input_section<big_endian>(relobj, shndx);
10840 arm_input_section->init();
10841
10842 // Register new Arm_input_section in map for look-up.
10843 std::pair<typename Arm_input_section_map::iterator, bool> ins =
10844 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
10845
10846 // Make sure that it we have not created another Arm_input_section
10847 // for this input section already.
10848 gold_assert(ins.second);
10849
10850 return arm_input_section;
10851 }
10852
10853 // Find the Arm_input_section object corresponding to the SHNDX-th input
10854 // section of RELOBJ.
10855
10856 template<bool big_endian>
10857 Arm_input_section<big_endian>*
10858 Target_arm<big_endian>::find_arm_input_section(
10859 Relobj* relobj,
10860 unsigned int shndx) const
10861 {
10862 Section_id sid(relobj, shndx);
10863 typename Arm_input_section_map::const_iterator p =
10864 this->arm_input_section_map_.find(sid);
10865 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
10866 }
10867
10868 // Make a new stub table.
10869
10870 template<bool big_endian>
10871 Stub_table<big_endian>*
10872 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
10873 {
10874 Stub_table<big_endian>* stub_table =
10875 new Stub_table<big_endian>(owner);
10876 this->stub_tables_.push_back(stub_table);
10877
10878 stub_table->set_address(owner->address() + owner->data_size());
10879 stub_table->set_file_offset(owner->offset() + owner->data_size());
10880 stub_table->finalize_data_size();
10881
10882 return stub_table;
10883 }
10884
10885 // Scan a relocation for stub generation.
10886
10887 template<bool big_endian>
10888 void
10889 Target_arm<big_endian>::scan_reloc_for_stub(
10890 const Relocate_info<32, big_endian>* relinfo,
10891 unsigned int r_type,
10892 const Sized_symbol<32>* gsym,
10893 unsigned int r_sym,
10894 const Symbol_value<32>* psymval,
10895 elfcpp::Elf_types<32>::Elf_Swxword addend,
10896 Arm_address address)
10897 {
10898 typedef typename Target_arm<big_endian>::Relocate Relocate;
10899
10900 const Arm_relobj<big_endian>* arm_relobj =
10901 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10902
10903 bool target_is_thumb;
10904 Symbol_value<32> symval;
10905 if (gsym != NULL)
10906 {
10907 // This is a global symbol. Determine if we use PLT and if the
10908 // final target is THUMB.
10909 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
10910 {
10911 // This uses a PLT, change the symbol value.
10912 symval.set_output_value(this->plt_section()->address()
10913 + gsym->plt_offset());
10914 psymval = &symval;
10915 target_is_thumb = false;
10916 }
10917 else if (gsym->is_undefined())
10918 // There is no need to generate a stub symbol is undefined.
10919 return;
10920 else
10921 {
10922 target_is_thumb =
10923 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
10924 || (gsym->type() == elfcpp::STT_FUNC
10925 && !gsym->is_undefined()
10926 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
10927 }
10928 }
10929 else
10930 {
10931 // This is a local symbol. Determine if the final target is THUMB.
10932 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
10933 }
10934
10935 // Strip LSB if this points to a THUMB target.
10936 const Arm_reloc_property* reloc_property =
10937 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10938 gold_assert(reloc_property != NULL);
10939 if (target_is_thumb
10940 && reloc_property->uses_thumb_bit()
10941 && ((psymval->value(arm_relobj, 0) & 1) != 0))
10942 {
10943 Arm_address stripped_value =
10944 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
10945 symval.set_output_value(stripped_value);
10946 psymval = &symval;
10947 }
10948
10949 // Get the symbol value.
10950 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
10951
10952 // Owing to pipelining, the PC relative branches below actually skip
10953 // two instructions when the branch offset is 0.
10954 Arm_address destination;
10955 switch (r_type)
10956 {
10957 case elfcpp::R_ARM_CALL:
10958 case elfcpp::R_ARM_JUMP24:
10959 case elfcpp::R_ARM_PLT32:
10960 // ARM branches.
10961 destination = value + addend + 8;
10962 break;
10963 case elfcpp::R_ARM_THM_CALL:
10964 case elfcpp::R_ARM_THM_XPC22:
10965 case elfcpp::R_ARM_THM_JUMP24:
10966 case elfcpp::R_ARM_THM_JUMP19:
10967 // THUMB branches.
10968 destination = value + addend + 4;
10969 break;
10970 default:
10971 gold_unreachable();
10972 }
10973
10974 Reloc_stub* stub = NULL;
10975 Stub_type stub_type =
10976 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
10977 target_is_thumb);
10978 if (stub_type != arm_stub_none)
10979 {
10980 // Try looking up an existing stub from a stub table.
10981 Stub_table<big_endian>* stub_table =
10982 arm_relobj->stub_table(relinfo->data_shndx);
10983 gold_assert(stub_table != NULL);
10984
10985 // Locate stub by destination.
10986 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
10987
10988 // Create a stub if there is not one already
10989 stub = stub_table->find_reloc_stub(stub_key);
10990 if (stub == NULL)
10991 {
10992 // create a new stub and add it to stub table.
10993 stub = this->stub_factory().make_reloc_stub(stub_type);
10994 stub_table->add_reloc_stub(stub, stub_key);
10995 }
10996
10997 // Record the destination address.
10998 stub->set_destination_address(destination
10999 | (target_is_thumb ? 1 : 0));
11000 }
11001
11002 // For Cortex-A8, we need to record a relocation at 4K page boundary.
11003 if (this->fix_cortex_a8_
11004 && (r_type == elfcpp::R_ARM_THM_JUMP24
11005 || r_type == elfcpp::R_ARM_THM_JUMP19
11006 || r_type == elfcpp::R_ARM_THM_CALL
11007 || r_type == elfcpp::R_ARM_THM_XPC22)
11008 && (address & 0xfffU) == 0xffeU)
11009 {
11010 // Found a candidate. Note we haven't checked the destination is
11011 // within 4K here: if we do so (and don't create a record) we can't
11012 // tell that a branch should have been relocated when scanning later.
11013 this->cortex_a8_relocs_info_[address] =
11014 new Cortex_a8_reloc(stub, r_type,
11015 destination | (target_is_thumb ? 1 : 0));
11016 }
11017 }
11018
11019 // This function scans a relocation sections for stub generation.
11020 // The template parameter Relocate must be a class type which provides
11021 // a single function, relocate(), which implements the machine
11022 // specific part of a relocation.
11023
11024 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11025 // SHT_REL or SHT_RELA.
11026
11027 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11028 // of relocs. OUTPUT_SECTION is the output section.
11029 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11030 // mapped to output offsets.
11031
11032 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11033 // VIEW_SIZE is the size. These refer to the input section, unless
11034 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11035 // the output section.
11036
11037 template<bool big_endian>
11038 template<int sh_type>
11039 void inline
11040 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11041 const Relocate_info<32, big_endian>* relinfo,
11042 const unsigned char* prelocs,
11043 size_t reloc_count,
11044 Output_section* output_section,
11045 bool needs_special_offset_handling,
11046 const unsigned char* view,
11047 elfcpp::Elf_types<32>::Elf_Addr view_address,
11048 section_size_type)
11049 {
11050 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11051 const int reloc_size =
11052 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11053
11054 Arm_relobj<big_endian>* arm_object =
11055 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11056 unsigned int local_count = arm_object->local_symbol_count();
11057
11058 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11059
11060 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11061 {
11062 Reltype reloc(prelocs);
11063
11064 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11065 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11066 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11067
11068 r_type = this->get_real_reloc_type(r_type);
11069
11070 // Only a few relocation types need stubs.
11071 if ((r_type != elfcpp::R_ARM_CALL)
11072 && (r_type != elfcpp::R_ARM_JUMP24)
11073 && (r_type != elfcpp::R_ARM_PLT32)
11074 && (r_type != elfcpp::R_ARM_THM_CALL)
11075 && (r_type != elfcpp::R_ARM_THM_XPC22)
11076 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11077 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11078 && (r_type != elfcpp::R_ARM_V4BX))
11079 continue;
11080
11081 section_offset_type offset =
11082 convert_to_section_size_type(reloc.get_r_offset());
11083
11084 if (needs_special_offset_handling)
11085 {
11086 offset = output_section->output_offset(relinfo->object,
11087 relinfo->data_shndx,
11088 offset);
11089 if (offset == -1)
11090 continue;
11091 }
11092
11093 // Create a v4bx stub if --fix-v4bx-interworking is used.
11094 if (r_type == elfcpp::R_ARM_V4BX)
11095 {
11096 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11097 {
11098 // Get the BX instruction.
11099 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11100 const Valtype* wv =
11101 reinterpret_cast<const Valtype*>(view + offset);
11102 elfcpp::Elf_types<32>::Elf_Swxword insn =
11103 elfcpp::Swap<32, big_endian>::readval(wv);
11104 const uint32_t reg = (insn & 0xf);
11105
11106 if (reg < 0xf)
11107 {
11108 // Try looking up an existing stub from a stub table.
11109 Stub_table<big_endian>* stub_table =
11110 arm_object->stub_table(relinfo->data_shndx);
11111 gold_assert(stub_table != NULL);
11112
11113 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11114 {
11115 // create a new stub and add it to stub table.
11116 Arm_v4bx_stub* stub =
11117 this->stub_factory().make_arm_v4bx_stub(reg);
11118 gold_assert(stub != NULL);
11119 stub_table->add_arm_v4bx_stub(stub);
11120 }
11121 }
11122 }
11123 continue;
11124 }
11125
11126 // Get the addend.
11127 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11128 elfcpp::Elf_types<32>::Elf_Swxword addend =
11129 stub_addend_reader(r_type, view + offset, reloc);
11130
11131 const Sized_symbol<32>* sym;
11132
11133 Symbol_value<32> symval;
11134 const Symbol_value<32> *psymval;
11135 bool is_defined_in_discarded_section;
11136 unsigned int shndx;
11137 if (r_sym < local_count)
11138 {
11139 sym = NULL;
11140 psymval = arm_object->local_symbol(r_sym);
11141
11142 // If the local symbol belongs to a section we are discarding,
11143 // and that section is a debug section, try to find the
11144 // corresponding kept section and map this symbol to its
11145 // counterpart in the kept section. The symbol must not
11146 // correspond to a section we are folding.
11147 bool is_ordinary;
11148 shndx = psymval->input_shndx(&is_ordinary);
11149 is_defined_in_discarded_section =
11150 (is_ordinary
11151 && shndx != elfcpp::SHN_UNDEF
11152 && !arm_object->is_section_included(shndx)
11153 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11154
11155 // We need to compute the would-be final value of this local
11156 // symbol.
11157 if (!is_defined_in_discarded_section)
11158 {
11159 typedef Sized_relobj_file<32, big_endian> ObjType;
11160 typename ObjType::Compute_final_local_value_status status =
11161 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11162 relinfo->symtab);
11163 if (status == ObjType::CFLV_OK)
11164 {
11165 // Currently we cannot handle a branch to a target in
11166 // a merged section. If this is the case, issue an error
11167 // and also free the merge symbol value.
11168 if (!symval.has_output_value())
11169 {
11170 const std::string& section_name =
11171 arm_object->section_name(shndx);
11172 arm_object->error(_("cannot handle branch to local %u "
11173 "in a merged section %s"),
11174 r_sym, section_name.c_str());
11175 }
11176 psymval = &symval;
11177 }
11178 else
11179 {
11180 // We cannot determine the final value.
11181 continue;
11182 }
11183 }
11184 }
11185 else
11186 {
11187 const Symbol* gsym;
11188 gsym = arm_object->global_symbol(r_sym);
11189 gold_assert(gsym != NULL);
11190 if (gsym->is_forwarder())
11191 gsym = relinfo->symtab->resolve_forwards(gsym);
11192
11193 sym = static_cast<const Sized_symbol<32>*>(gsym);
11194 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11195 symval.set_output_symtab_index(sym->symtab_index());
11196 else
11197 symval.set_no_output_symtab_entry();
11198
11199 // We need to compute the would-be final value of this global
11200 // symbol.
11201 const Symbol_table* symtab = relinfo->symtab;
11202 const Sized_symbol<32>* sized_symbol =
11203 symtab->get_sized_symbol<32>(gsym);
11204 Symbol_table::Compute_final_value_status status;
11205 Arm_address value =
11206 symtab->compute_final_value<32>(sized_symbol, &status);
11207
11208 // Skip this if the symbol has not output section.
11209 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11210 continue;
11211 symval.set_output_value(value);
11212
11213 if (gsym->type() == elfcpp::STT_TLS)
11214 symval.set_is_tls_symbol();
11215 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11216 symval.set_is_ifunc_symbol();
11217 psymval = &symval;
11218
11219 is_defined_in_discarded_section =
11220 (gsym->is_defined_in_discarded_section()
11221 && gsym->is_undefined());
11222 shndx = 0;
11223 }
11224
11225 Symbol_value<32> symval2;
11226 if (is_defined_in_discarded_section)
11227 {
11228 if (comdat_behavior == CB_UNDETERMINED)
11229 {
11230 std::string name = arm_object->section_name(relinfo->data_shndx);
11231 comdat_behavior = get_comdat_behavior(name.c_str());
11232 }
11233 if (comdat_behavior == CB_PRETEND)
11234 {
11235 // FIXME: This case does not work for global symbols.
11236 // We have no place to store the original section index.
11237 // Fortunately this does not matter for comdat sections,
11238 // only for sections explicitly discarded by a linker
11239 // script.
11240 bool found;
11241 typename elfcpp::Elf_types<32>::Elf_Addr value =
11242 arm_object->map_to_kept_section(shndx, &found);
11243 if (found)
11244 symval2.set_output_value(value + psymval->input_value());
11245 else
11246 symval2.set_output_value(0);
11247 }
11248 else
11249 {
11250 if (comdat_behavior == CB_WARNING)
11251 gold_warning_at_location(relinfo, i, offset,
11252 _("relocation refers to discarded "
11253 "section"));
11254 symval2.set_output_value(0);
11255 }
11256 symval2.set_no_output_symtab_entry();
11257 psymval = &symval2;
11258 }
11259
11260 // If symbol is a section symbol, we don't know the actual type of
11261 // destination. Give up.
11262 if (psymval->is_section_symbol())
11263 continue;
11264
11265 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11266 addend, view_address + offset);
11267 }
11268 }
11269
11270 // Scan an input section for stub generation.
11271
11272 template<bool big_endian>
11273 void
11274 Target_arm<big_endian>::scan_section_for_stubs(
11275 const Relocate_info<32, big_endian>* relinfo,
11276 unsigned int sh_type,
11277 const unsigned char* prelocs,
11278 size_t reloc_count,
11279 Output_section* output_section,
11280 bool needs_special_offset_handling,
11281 const unsigned char* view,
11282 Arm_address view_address,
11283 section_size_type view_size)
11284 {
11285 if (sh_type == elfcpp::SHT_REL)
11286 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11287 relinfo,
11288 prelocs,
11289 reloc_count,
11290 output_section,
11291 needs_special_offset_handling,
11292 view,
11293 view_address,
11294 view_size);
11295 else if (sh_type == elfcpp::SHT_RELA)
11296 // We do not support RELA type relocations yet. This is provided for
11297 // completeness.
11298 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11299 relinfo,
11300 prelocs,
11301 reloc_count,
11302 output_section,
11303 needs_special_offset_handling,
11304 view,
11305 view_address,
11306 view_size);
11307 else
11308 gold_unreachable();
11309 }
11310
11311 // Group input sections for stub generation.
11312 //
11313 // We group input sections in an output section so that the total size,
11314 // including any padding space due to alignment is smaller than GROUP_SIZE
11315 // unless the only input section in group is bigger than GROUP_SIZE already.
11316 // Then an ARM stub table is created to follow the last input section
11317 // in group. For each group an ARM stub table is created an is placed
11318 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
11319 // extend the group after the stub table.
11320
11321 template<bool big_endian>
11322 void
11323 Target_arm<big_endian>::group_sections(
11324 Layout* layout,
11325 section_size_type group_size,
11326 bool stubs_always_after_branch,
11327 const Task* task)
11328 {
11329 // Group input sections and insert stub table
11330 Layout::Section_list section_list;
11331 layout->get_allocated_sections(&section_list);
11332 for (Layout::Section_list::const_iterator p = section_list.begin();
11333 p != section_list.end();
11334 ++p)
11335 {
11336 Arm_output_section<big_endian>* output_section =
11337 Arm_output_section<big_endian>::as_arm_output_section(*p);
11338 output_section->group_sections(group_size, stubs_always_after_branch,
11339 this, task);
11340 }
11341 }
11342
11343 // Relaxation hook. This is where we do stub generation.
11344
11345 template<bool big_endian>
11346 bool
11347 Target_arm<big_endian>::do_relax(
11348 int pass,
11349 const Input_objects* input_objects,
11350 Symbol_table* symtab,
11351 Layout* layout,
11352 const Task* task)
11353 {
11354 // No need to generate stubs if this is a relocatable link.
11355 gold_assert(!parameters->options().relocatable());
11356
11357 // If this is the first pass, we need to group input sections into
11358 // stub groups.
11359 bool done_exidx_fixup = false;
11360 typedef typename Stub_table_list::iterator Stub_table_iterator;
11361 if (pass == 1)
11362 {
11363 // Determine the stub group size. The group size is the absolute
11364 // value of the parameter --stub-group-size. If --stub-group-size
11365 // is passed a negative value, we restrict stubs to be always after
11366 // the stubbed branches.
11367 int32_t stub_group_size_param =
11368 parameters->options().stub_group_size();
11369 bool stubs_always_after_branch = stub_group_size_param < 0;
11370 section_size_type stub_group_size = abs(stub_group_size_param);
11371
11372 if (stub_group_size == 1)
11373 {
11374 // Default value.
11375 // Thumb branch range is +-4MB has to be used as the default
11376 // maximum size (a given section can contain both ARM and Thumb
11377 // code, so the worst case has to be taken into account). If we are
11378 // fixing cortex-a8 errata, the branch range has to be even smaller,
11379 // since wide conditional branch has a range of +-1MB only.
11380 //
11381 // This value is 48K less than that, which allows for 4096
11382 // 12-byte stubs. If we exceed that, then we will fail to link.
11383 // The user will have to relink with an explicit group size
11384 // option.
11385 stub_group_size = 4145152;
11386 }
11387
11388 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11389 // page as the first half of a 32-bit branch straddling two 4K pages.
11390 // This is a crude way of enforcing that. In addition, long conditional
11391 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11392 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11393 // cortex-A8 stubs from long conditional branches.
11394 if (this->fix_cortex_a8_)
11395 {
11396 stubs_always_after_branch = true;
11397 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11398 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11399 }
11400
11401 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11402
11403 // Also fix .ARM.exidx section coverage.
11404 Arm_output_section<big_endian>* exidx_output_section = NULL;
11405 for (Layout::Section_list::const_iterator p =
11406 layout->section_list().begin();
11407 p != layout->section_list().end();
11408 ++p)
11409 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11410 {
11411 if (exidx_output_section == NULL)
11412 exidx_output_section =
11413 Arm_output_section<big_endian>::as_arm_output_section(*p);
11414 else
11415 // We cannot handle this now.
11416 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11417 "non-relocatable link"),
11418 exidx_output_section->name(),
11419 (*p)->name());
11420 }
11421
11422 if (exidx_output_section != NULL)
11423 {
11424 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11425 symtab, task);
11426 done_exidx_fixup = true;
11427 }
11428 }
11429 else
11430 {
11431 // If this is not the first pass, addresses and file offsets have
11432 // been reset at this point, set them here.
11433 for (Stub_table_iterator sp = this->stub_tables_.begin();
11434 sp != this->stub_tables_.end();
11435 ++sp)
11436 {
11437 Arm_input_section<big_endian>* owner = (*sp)->owner();
11438 off_t off = align_address(owner->original_size(),
11439 (*sp)->addralign());
11440 (*sp)->set_address_and_file_offset(owner->address() + off,
11441 owner->offset() + off);
11442 }
11443 }
11444
11445 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11446 // beginning of each relaxation pass, just blow away all the stubs.
11447 // Alternatively, we could selectively remove only the stubs and reloc
11448 // information for code sections that have moved since the last pass.
11449 // That would require more book-keeping.
11450 if (this->fix_cortex_a8_)
11451 {
11452 // Clear all Cortex-A8 reloc information.
11453 for (typename Cortex_a8_relocs_info::const_iterator p =
11454 this->cortex_a8_relocs_info_.begin();
11455 p != this->cortex_a8_relocs_info_.end();
11456 ++p)
11457 delete p->second;
11458 this->cortex_a8_relocs_info_.clear();
11459
11460 // Remove all Cortex-A8 stubs.
11461 for (Stub_table_iterator sp = this->stub_tables_.begin();
11462 sp != this->stub_tables_.end();
11463 ++sp)
11464 (*sp)->remove_all_cortex_a8_stubs();
11465 }
11466
11467 // Scan relocs for relocation stubs
11468 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11469 op != input_objects->relobj_end();
11470 ++op)
11471 {
11472 Arm_relobj<big_endian>* arm_relobj =
11473 Arm_relobj<big_endian>::as_arm_relobj(*op);
11474 // Lock the object so we can read from it. This is only called
11475 // single-threaded from Layout::finalize, so it is OK to lock.
11476 Task_lock_obj<Object> tl(task, arm_relobj);
11477 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11478 }
11479
11480 // Check all stub tables to see if any of them have their data sizes
11481 // or addresses alignments changed. These are the only things that
11482 // matter.
11483 bool any_stub_table_changed = false;
11484 Unordered_set<const Output_section*> sections_needing_adjustment;
11485 for (Stub_table_iterator sp = this->stub_tables_.begin();
11486 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11487 ++sp)
11488 {
11489 if ((*sp)->update_data_size_and_addralign())
11490 {
11491 // Update data size of stub table owner.
11492 Arm_input_section<big_endian>* owner = (*sp)->owner();
11493 uint64_t address = owner->address();
11494 off_t offset = owner->offset();
11495 owner->reset_address_and_file_offset();
11496 owner->set_address_and_file_offset(address, offset);
11497
11498 sections_needing_adjustment.insert(owner->output_section());
11499 any_stub_table_changed = true;
11500 }
11501 }
11502
11503 // Output_section_data::output_section() returns a const pointer but we
11504 // need to update output sections, so we record all output sections needing
11505 // update above and scan the sections here to find out what sections need
11506 // to be updated.
11507 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11508 p != layout->section_list().end();
11509 ++p)
11510 {
11511 if (sections_needing_adjustment.find(*p)
11512 != sections_needing_adjustment.end())
11513 (*p)->set_section_offsets_need_adjustment();
11514 }
11515
11516 // Stop relaxation if no EXIDX fix-up and no stub table change.
11517 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11518
11519 // Finalize the stubs in the last relaxation pass.
11520 if (!continue_relaxation)
11521 {
11522 for (Stub_table_iterator sp = this->stub_tables_.begin();
11523 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11524 ++sp)
11525 (*sp)->finalize_stubs();
11526
11527 // Update output local symbol counts of objects if necessary.
11528 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11529 op != input_objects->relobj_end();
11530 ++op)
11531 {
11532 Arm_relobj<big_endian>* arm_relobj =
11533 Arm_relobj<big_endian>::as_arm_relobj(*op);
11534
11535 // Update output local symbol counts. We need to discard local
11536 // symbols defined in parts of input sections that are discarded by
11537 // relaxation.
11538 if (arm_relobj->output_local_symbol_count_needs_update())
11539 {
11540 // We need to lock the object's file to update it.
11541 Task_lock_obj<Object> tl(task, arm_relobj);
11542 arm_relobj->update_output_local_symbol_count();
11543 }
11544 }
11545 }
11546
11547 return continue_relaxation;
11548 }
11549
11550 // Relocate a stub.
11551
11552 template<bool big_endian>
11553 void
11554 Target_arm<big_endian>::relocate_stub(
11555 Stub* stub,
11556 const Relocate_info<32, big_endian>* relinfo,
11557 Output_section* output_section,
11558 unsigned char* view,
11559 Arm_address address,
11560 section_size_type view_size)
11561 {
11562 Relocate relocate;
11563 const Stub_template* stub_template = stub->stub_template();
11564 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11565 {
11566 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11567 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11568
11569 unsigned int r_type = insn->r_type();
11570 section_size_type reloc_offset = stub_template->reloc_offset(i);
11571 section_size_type reloc_size = insn->size();
11572 gold_assert(reloc_offset + reloc_size <= view_size);
11573
11574 // This is the address of the stub destination.
11575 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11576 Symbol_value<32> symval;
11577 symval.set_output_value(target);
11578
11579 // Synthesize a fake reloc just in case. We don't have a symbol so
11580 // we use 0.
11581 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11582 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11583 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11584 reloc_write.put_r_offset(reloc_offset);
11585 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11586 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11587
11588 relocate.relocate(relinfo, this, output_section,
11589 this->fake_relnum_for_stubs, rel, r_type,
11590 NULL, &symval, view + reloc_offset,
11591 address + reloc_offset, reloc_size);
11592 }
11593 }
11594
11595 // Determine whether an object attribute tag takes an integer, a
11596 // string or both.
11597
11598 template<bool big_endian>
11599 int
11600 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11601 {
11602 if (tag == Object_attribute::Tag_compatibility)
11603 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11604 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11605 else if (tag == elfcpp::Tag_nodefaults)
11606 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11607 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11608 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11609 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11610 else if (tag < 32)
11611 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11612 else
11613 return ((tag & 1) != 0
11614 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11615 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11616 }
11617
11618 // Reorder attributes.
11619 //
11620 // The ABI defines that Tag_conformance should be emitted first, and that
11621 // Tag_nodefaults should be second (if either is defined). This sets those
11622 // two positions, and bumps up the position of all the remaining tags to
11623 // compensate.
11624
11625 template<bool big_endian>
11626 int
11627 Target_arm<big_endian>::do_attributes_order(int num) const
11628 {
11629 // Reorder the known object attributes in output. We want to move
11630 // Tag_conformance to position 4 and Tag_conformance to position 5
11631 // and shift everything between 4 .. Tag_conformance - 1 to make room.
11632 if (num == 4)
11633 return elfcpp::Tag_conformance;
11634 if (num == 5)
11635 return elfcpp::Tag_nodefaults;
11636 if ((num - 2) < elfcpp::Tag_nodefaults)
11637 return num - 2;
11638 if ((num - 1) < elfcpp::Tag_conformance)
11639 return num - 1;
11640 return num;
11641 }
11642
11643 // Scan a span of THUMB code for Cortex-A8 erratum.
11644
11645 template<bool big_endian>
11646 void
11647 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11648 Arm_relobj<big_endian>* arm_relobj,
11649 unsigned int shndx,
11650 section_size_type span_start,
11651 section_size_type span_end,
11652 const unsigned char* view,
11653 Arm_address address)
11654 {
11655 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11656 //
11657 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11658 // The branch target is in the same 4KB region as the
11659 // first half of the branch.
11660 // The instruction before the branch is a 32-bit
11661 // length non-branch instruction.
11662 section_size_type i = span_start;
11663 bool last_was_32bit = false;
11664 bool last_was_branch = false;
11665 while (i < span_end)
11666 {
11667 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11668 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11669 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11670 bool is_blx = false, is_b = false;
11671 bool is_bl = false, is_bcc = false;
11672
11673 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11674 if (insn_32bit)
11675 {
11676 // Load the rest of the insn (in manual-friendly order).
11677 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11678
11679 // Encoding T4: B<c>.W.
11680 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11681 // Encoding T1: BL<c>.W.
11682 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11683 // Encoding T2: BLX<c>.W.
11684 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11685 // Encoding T3: B<c>.W (not permitted in IT block).
11686 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11687 && (insn & 0x07f00000U) != 0x03800000U);
11688 }
11689
11690 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11691
11692 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11693 // page boundary and it follows 32-bit non-branch instruction,
11694 // we need to work around.
11695 if (is_32bit_branch
11696 && ((address + i) & 0xfffU) == 0xffeU
11697 && last_was_32bit
11698 && !last_was_branch)
11699 {
11700 // Check to see if there is a relocation stub for this branch.
11701 bool force_target_arm = false;
11702 bool force_target_thumb = false;
11703 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11704 Cortex_a8_relocs_info::const_iterator p =
11705 this->cortex_a8_relocs_info_.find(address + i);
11706
11707 if (p != this->cortex_a8_relocs_info_.end())
11708 {
11709 cortex_a8_reloc = p->second;
11710 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11711
11712 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11713 && !target_is_thumb)
11714 force_target_arm = true;
11715 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11716 && target_is_thumb)
11717 force_target_thumb = true;
11718 }
11719
11720 off_t offset;
11721 Stub_type stub_type = arm_stub_none;
11722
11723 // Check if we have an offending branch instruction.
11724 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11725 uint16_t lower_insn = insn & 0xffffU;
11726 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11727
11728 if (cortex_a8_reloc != NULL
11729 && cortex_a8_reloc->reloc_stub() != NULL)
11730 // We've already made a stub for this instruction, e.g.
11731 // it's a long branch or a Thumb->ARM stub. Assume that
11732 // stub will suffice to work around the A8 erratum (see
11733 // setting of always_after_branch above).
11734 ;
11735 else if (is_bcc)
11736 {
11737 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11738 lower_insn);
11739 stub_type = arm_stub_a8_veneer_b_cond;
11740 }
11741 else if (is_b || is_bl || is_blx)
11742 {
11743 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11744 lower_insn);
11745 if (is_blx)
11746 offset &= ~3;
11747
11748 stub_type = (is_blx
11749 ? arm_stub_a8_veneer_blx
11750 : (is_bl
11751 ? arm_stub_a8_veneer_bl
11752 : arm_stub_a8_veneer_b));
11753 }
11754
11755 if (stub_type != arm_stub_none)
11756 {
11757 Arm_address pc_for_insn = address + i + 4;
11758
11759 // The original instruction is a BL, but the target is
11760 // an ARM instruction. If we were not making a stub,
11761 // the BL would have been converted to a BLX. Use the
11762 // BLX stub instead in that case.
11763 if (this->may_use_v5t_interworking() && force_target_arm
11764 && stub_type == arm_stub_a8_veneer_bl)
11765 {
11766 stub_type = arm_stub_a8_veneer_blx;
11767 is_blx = true;
11768 is_bl = false;
11769 }
11770 // Conversely, if the original instruction was
11771 // BLX but the target is Thumb mode, use the BL stub.
11772 else if (force_target_thumb
11773 && stub_type == arm_stub_a8_veneer_blx)
11774 {
11775 stub_type = arm_stub_a8_veneer_bl;
11776 is_blx = false;
11777 is_bl = true;
11778 }
11779
11780 if (is_blx)
11781 pc_for_insn &= ~3;
11782
11783 // If we found a relocation, use the proper destination,
11784 // not the offset in the (unrelocated) instruction.
11785 // Note this is always done if we switched the stub type above.
11786 if (cortex_a8_reloc != NULL)
11787 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11788
11789 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11790
11791 // Add a new stub if destination address in in the same page.
11792 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11793 {
11794 Cortex_a8_stub* stub =
11795 this->stub_factory_.make_cortex_a8_stub(stub_type,
11796 arm_relobj, shndx,
11797 address + i,
11798 target, insn);
11799 Stub_table<big_endian>* stub_table =
11800 arm_relobj->stub_table(shndx);
11801 gold_assert(stub_table != NULL);
11802 stub_table->add_cortex_a8_stub(address + i, stub);
11803 }
11804 }
11805 }
11806
11807 i += insn_32bit ? 4 : 2;
11808 last_was_32bit = insn_32bit;
11809 last_was_branch = is_32bit_branch;
11810 }
11811 }
11812
11813 // Apply the Cortex-A8 workaround.
11814
11815 template<bool big_endian>
11816 void
11817 Target_arm<big_endian>::apply_cortex_a8_workaround(
11818 const Cortex_a8_stub* stub,
11819 Arm_address stub_address,
11820 unsigned char* insn_view,
11821 Arm_address insn_address)
11822 {
11823 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11824 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11825 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
11826 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
11827 off_t branch_offset = stub_address - (insn_address + 4);
11828
11829 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
11830 switch (stub->stub_template()->type())
11831 {
11832 case arm_stub_a8_veneer_b_cond:
11833 // For a conditional branch, we re-write it to be an unconditional
11834 // branch to the stub. We use the THUMB-2 encoding here.
11835 upper_insn = 0xf000U;
11836 lower_insn = 0xb800U;
11837 // Fall through
11838 case arm_stub_a8_veneer_b:
11839 case arm_stub_a8_veneer_bl:
11840 case arm_stub_a8_veneer_blx:
11841 if ((lower_insn & 0x5000U) == 0x4000U)
11842 // For a BLX instruction, make sure that the relocation is
11843 // rounded up to a word boundary. This follows the semantics of
11844 // the instruction which specifies that bit 1 of the target
11845 // address will come from bit 1 of the base address.
11846 branch_offset = (branch_offset + 2) & ~3;
11847
11848 // Put BRANCH_OFFSET back into the insn.
11849 gold_assert(!Bits<25>::has_overflow32(branch_offset));
11850 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
11851 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
11852 break;
11853
11854 default:
11855 gold_unreachable();
11856 }
11857
11858 // Put the relocated value back in the object file:
11859 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
11860 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
11861 }
11862
11863 template<bool big_endian>
11864 class Target_selector_arm : public Target_selector
11865 {
11866 public:
11867 Target_selector_arm()
11868 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
11869 (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
11870 (big_endian ? "armelfb" : "armelf"))
11871 { }
11872
11873 Target*
11874 do_instantiate_target()
11875 { return new Target_arm<big_endian>(); }
11876 };
11877
11878 // Fix .ARM.exidx section coverage.
11879
11880 template<bool big_endian>
11881 void
11882 Target_arm<big_endian>::fix_exidx_coverage(
11883 Layout* layout,
11884 const Input_objects* input_objects,
11885 Arm_output_section<big_endian>* exidx_section,
11886 Symbol_table* symtab,
11887 const Task* task)
11888 {
11889 // We need to look at all the input sections in output in ascending
11890 // order of of output address. We do that by building a sorted list
11891 // of output sections by addresses. Then we looks at the output sections
11892 // in order. The input sections in an output section are already sorted
11893 // by addresses within the output section.
11894
11895 typedef std::set<Output_section*, output_section_address_less_than>
11896 Sorted_output_section_list;
11897 Sorted_output_section_list sorted_output_sections;
11898
11899 // Find out all the output sections of input sections pointed by
11900 // EXIDX input sections.
11901 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
11902 p != input_objects->relobj_end();
11903 ++p)
11904 {
11905 Arm_relobj<big_endian>* arm_relobj =
11906 Arm_relobj<big_endian>::as_arm_relobj(*p);
11907 std::vector<unsigned int> shndx_list;
11908 arm_relobj->get_exidx_shndx_list(&shndx_list);
11909 for (size_t i = 0; i < shndx_list.size(); ++i)
11910 {
11911 const Arm_exidx_input_section* exidx_input_section =
11912 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
11913 gold_assert(exidx_input_section != NULL);
11914 if (!exidx_input_section->has_errors())
11915 {
11916 unsigned int text_shndx = exidx_input_section->link();
11917 Output_section* os = arm_relobj->output_section(text_shndx);
11918 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
11919 sorted_output_sections.insert(os);
11920 }
11921 }
11922 }
11923
11924 // Go over the output sections in ascending order of output addresses.
11925 typedef typename Arm_output_section<big_endian>::Text_section_list
11926 Text_section_list;
11927 Text_section_list sorted_text_sections;
11928 for (typename Sorted_output_section_list::iterator p =
11929 sorted_output_sections.begin();
11930 p != sorted_output_sections.end();
11931 ++p)
11932 {
11933 Arm_output_section<big_endian>* arm_output_section =
11934 Arm_output_section<big_endian>::as_arm_output_section(*p);
11935 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
11936 }
11937
11938 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
11939 merge_exidx_entries(), task);
11940 }
11941
11942 Target_selector_arm<false> target_selector_arm;
11943 Target_selector_arm<true> target_selector_armbe;
11944
11945 } // End anonymous namespace.
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