* target-reloc.h (relocate_section): If the reloc offset is out of
[deliverable/binutils-gdb.git] / gold / arm.cc
1 // arm.cc -- arm target support for gold.
2
3 // Copyright 2009, 2010, 2011, 2012, 2013 Free Software Foundation, Inc.
4 // Written by Doug Kwan <dougkwan@google.com> based on the i386 code
5 // by Ian Lance Taylor <iant@google.com>.
6 // This file also contains borrowed and adapted code from
7 // bfd/elf32-arm.c.
8
9 // This file is part of gold.
10
11 // This program is free software; you can redistribute it and/or modify
12 // it under the terms of the GNU General Public License as published by
13 // the Free Software Foundation; either version 3 of the License, or
14 // (at your option) any later version.
15
16 // This program is distributed in the hope that it will be useful,
17 // but WITHOUT ANY WARRANTY; without even the implied warranty of
18 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 // GNU General Public License for more details.
20
21 // You should have received a copy of the GNU General Public License
22 // along with this program; if not, write to the Free Software
23 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
24 // MA 02110-1301, USA.
25
26 #include "gold.h"
27
28 #include <cstring>
29 #include <limits>
30 #include <cstdio>
31 #include <string>
32 #include <algorithm>
33 #include <map>
34 #include <utility>
35 #include <set>
36
37 #include "elfcpp.h"
38 #include "parameters.h"
39 #include "reloc.h"
40 #include "arm.h"
41 #include "object.h"
42 #include "symtab.h"
43 #include "layout.h"
44 #include "output.h"
45 #include "copy-relocs.h"
46 #include "target.h"
47 #include "target-reloc.h"
48 #include "target-select.h"
49 #include "tls.h"
50 #include "defstd.h"
51 #include "gc.h"
52 #include "attributes.h"
53 #include "arm-reloc-property.h"
54 #include "nacl.h"
55
56 namespace
57 {
58
59 using namespace gold;
60
61 template<bool big_endian>
62 class Output_data_plt_arm;
63
64 template<bool big_endian>
65 class Output_data_plt_arm_standard;
66
67 template<bool big_endian>
68 class Stub_table;
69
70 template<bool big_endian>
71 class Arm_input_section;
72
73 class Arm_exidx_cantunwind;
74
75 class Arm_exidx_merged_section;
76
77 class Arm_exidx_fixup;
78
79 template<bool big_endian>
80 class Arm_output_section;
81
82 class Arm_exidx_input_section;
83
84 template<bool big_endian>
85 class Arm_relobj;
86
87 template<bool big_endian>
88 class Arm_relocate_functions;
89
90 template<bool big_endian>
91 class Arm_output_data_got;
92
93 template<bool big_endian>
94 class Target_arm;
95
96 // For convenience.
97 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
98
99 // Maximum branch offsets for ARM, THUMB and THUMB2.
100 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
101 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
102 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
103 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
104 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
105 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
106
107 // Thread Control Block size.
108 const size_t ARM_TCB_SIZE = 8;
109
110 // The arm target class.
111 //
112 // This is a very simple port of gold for ARM-EABI. It is intended for
113 // supporting Android only for the time being.
114 //
115 // TODOs:
116 // - Implement all static relocation types documented in arm-reloc.def.
117 // - Make PLTs more flexible for different architecture features like
118 // Thumb-2 and BE8.
119 // There are probably a lot more.
120
121 // Ideally we would like to avoid using global variables but this is used
122 // very in many places and sometimes in loops. If we use a function
123 // returning a static instance of Arm_reloc_property_table, it will be very
124 // slow in an threaded environment since the static instance needs to be
125 // locked. The pointer is below initialized in the
126 // Target::do_select_as_default_target() hook so that we do not spend time
127 // building the table if we are not linking ARM objects.
128 //
129 // An alternative is to to process the information in arm-reloc.def in
130 // compilation time and generate a representation of it in PODs only. That
131 // way we can avoid initialization when the linker starts.
132
133 Arm_reloc_property_table* arm_reloc_property_table = NULL;
134
135 // Instruction template class. This class is similar to the insn_sequence
136 // struct in bfd/elf32-arm.c.
137
138 class Insn_template
139 {
140 public:
141 // Types of instruction templates.
142 enum Type
143 {
144 THUMB16_TYPE = 1,
145 // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
146 // templates with class-specific semantics. Currently this is used
147 // only by the Cortex_a8_stub class for handling condition codes in
148 // conditional branches.
149 THUMB16_SPECIAL_TYPE,
150 THUMB32_TYPE,
151 ARM_TYPE,
152 DATA_TYPE
153 };
154
155 // Factory methods to create instruction templates in different formats.
156
157 static const Insn_template
158 thumb16_insn(uint32_t data)
159 { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
160
161 // A Thumb conditional branch, in which the proper condition is inserted
162 // when we build the stub.
163 static const Insn_template
164 thumb16_bcond_insn(uint32_t data)
165 { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
166
167 static const Insn_template
168 thumb32_insn(uint32_t data)
169 { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
170
171 static const Insn_template
172 thumb32_b_insn(uint32_t data, int reloc_addend)
173 {
174 return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
175 reloc_addend);
176 }
177
178 static const Insn_template
179 arm_insn(uint32_t data)
180 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
181
182 static const Insn_template
183 arm_rel_insn(unsigned data, int reloc_addend)
184 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
185
186 static const Insn_template
187 data_word(unsigned data, unsigned int r_type, int reloc_addend)
188 { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
189
190 // Accessors. This class is used for read-only objects so no modifiers
191 // are provided.
192
193 uint32_t
194 data() const
195 { return this->data_; }
196
197 // Return the instruction sequence type of this.
198 Type
199 type() const
200 { return this->type_; }
201
202 // Return the ARM relocation type of this.
203 unsigned int
204 r_type() const
205 { return this->r_type_; }
206
207 int32_t
208 reloc_addend() const
209 { return this->reloc_addend_; }
210
211 // Return size of instruction template in bytes.
212 size_t
213 size() const;
214
215 // Return byte-alignment of instruction template.
216 unsigned
217 alignment() const;
218
219 private:
220 // We make the constructor private to ensure that only the factory
221 // methods are used.
222 inline
223 Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
224 : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
225 { }
226
227 // Instruction specific data. This is used to store information like
228 // some of the instruction bits.
229 uint32_t data_;
230 // Instruction template type.
231 Type type_;
232 // Relocation type if there is a relocation or R_ARM_NONE otherwise.
233 unsigned int r_type_;
234 // Relocation addend.
235 int32_t reloc_addend_;
236 };
237
238 // Macro for generating code to stub types. One entry per long/short
239 // branch stub
240
241 #define DEF_STUBS \
242 DEF_STUB(long_branch_any_any) \
243 DEF_STUB(long_branch_v4t_arm_thumb) \
244 DEF_STUB(long_branch_thumb_only) \
245 DEF_STUB(long_branch_v4t_thumb_thumb) \
246 DEF_STUB(long_branch_v4t_thumb_arm) \
247 DEF_STUB(short_branch_v4t_thumb_arm) \
248 DEF_STUB(long_branch_any_arm_pic) \
249 DEF_STUB(long_branch_any_thumb_pic) \
250 DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
251 DEF_STUB(long_branch_v4t_arm_thumb_pic) \
252 DEF_STUB(long_branch_v4t_thumb_arm_pic) \
253 DEF_STUB(long_branch_thumb_only_pic) \
254 DEF_STUB(a8_veneer_b_cond) \
255 DEF_STUB(a8_veneer_b) \
256 DEF_STUB(a8_veneer_bl) \
257 DEF_STUB(a8_veneer_blx) \
258 DEF_STUB(v4_veneer_bx)
259
260 // Stub types.
261
262 #define DEF_STUB(x) arm_stub_##x,
263 typedef enum
264 {
265 arm_stub_none,
266 DEF_STUBS
267
268 // First reloc stub type.
269 arm_stub_reloc_first = arm_stub_long_branch_any_any,
270 // Last reloc stub type.
271 arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
272
273 // First Cortex-A8 stub type.
274 arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
275 // Last Cortex-A8 stub type.
276 arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
277
278 // Last stub type.
279 arm_stub_type_last = arm_stub_v4_veneer_bx
280 } Stub_type;
281 #undef DEF_STUB
282
283 // Stub template class. Templates are meant to be read-only objects.
284 // A stub template for a stub type contains all read-only attributes
285 // common to all stubs of the same type.
286
287 class Stub_template
288 {
289 public:
290 Stub_template(Stub_type, const Insn_template*, size_t);
291
292 ~Stub_template()
293 { }
294
295 // Return stub type.
296 Stub_type
297 type() const
298 { return this->type_; }
299
300 // Return an array of instruction templates.
301 const Insn_template*
302 insns() const
303 { return this->insns_; }
304
305 // Return size of template in number of instructions.
306 size_t
307 insn_count() const
308 { return this->insn_count_; }
309
310 // Return size of template in bytes.
311 size_t
312 size() const
313 { return this->size_; }
314
315 // Return alignment of the stub template.
316 unsigned
317 alignment() const
318 { return this->alignment_; }
319
320 // Return whether entry point is in thumb mode.
321 bool
322 entry_in_thumb_mode() const
323 { return this->entry_in_thumb_mode_; }
324
325 // Return number of relocations in this template.
326 size_t
327 reloc_count() const
328 { return this->relocs_.size(); }
329
330 // Return index of the I-th instruction with relocation.
331 size_t
332 reloc_insn_index(size_t i) const
333 {
334 gold_assert(i < this->relocs_.size());
335 return this->relocs_[i].first;
336 }
337
338 // Return the offset of the I-th instruction with relocation from the
339 // beginning of the stub.
340 section_size_type
341 reloc_offset(size_t i) const
342 {
343 gold_assert(i < this->relocs_.size());
344 return this->relocs_[i].second;
345 }
346
347 private:
348 // This contains information about an instruction template with a relocation
349 // and its offset from start of stub.
350 typedef std::pair<size_t, section_size_type> Reloc;
351
352 // A Stub_template may not be copied. We want to share templates as much
353 // as possible.
354 Stub_template(const Stub_template&);
355 Stub_template& operator=(const Stub_template&);
356
357 // Stub type.
358 Stub_type type_;
359 // Points to an array of Insn_templates.
360 const Insn_template* insns_;
361 // Number of Insn_templates in insns_[].
362 size_t insn_count_;
363 // Size of templated instructions in bytes.
364 size_t size_;
365 // Alignment of templated instructions.
366 unsigned alignment_;
367 // Flag to indicate if entry is in thumb mode.
368 bool entry_in_thumb_mode_;
369 // A table of reloc instruction indices and offsets. We can find these by
370 // looking at the instruction templates but we pre-compute and then stash
371 // them here for speed.
372 std::vector<Reloc> relocs_;
373 };
374
375 //
376 // A class for code stubs. This is a base class for different type of
377 // stubs used in the ARM target.
378 //
379
380 class Stub
381 {
382 private:
383 static const section_offset_type invalid_offset =
384 static_cast<section_offset_type>(-1);
385
386 public:
387 Stub(const Stub_template* stub_template)
388 : stub_template_(stub_template), offset_(invalid_offset)
389 { }
390
391 virtual
392 ~Stub()
393 { }
394
395 // Return the stub template.
396 const Stub_template*
397 stub_template() const
398 { return this->stub_template_; }
399
400 // Return offset of code stub from beginning of its containing stub table.
401 section_offset_type
402 offset() const
403 {
404 gold_assert(this->offset_ != invalid_offset);
405 return this->offset_;
406 }
407
408 // Set offset of code stub from beginning of its containing stub table.
409 void
410 set_offset(section_offset_type offset)
411 { this->offset_ = offset; }
412
413 // Return the relocation target address of the i-th relocation in the
414 // stub. This must be defined in a child class.
415 Arm_address
416 reloc_target(size_t i)
417 { return this->do_reloc_target(i); }
418
419 // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written.
420 void
421 write(unsigned char* view, section_size_type view_size, bool big_endian)
422 { this->do_write(view, view_size, big_endian); }
423
424 // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
425 // for the i-th instruction.
426 uint16_t
427 thumb16_special(size_t i)
428 { return this->do_thumb16_special(i); }
429
430 protected:
431 // This must be defined in the child class.
432 virtual Arm_address
433 do_reloc_target(size_t) = 0;
434
435 // This may be overridden in the child class.
436 virtual void
437 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
438 {
439 if (big_endian)
440 this->do_fixed_endian_write<true>(view, view_size);
441 else
442 this->do_fixed_endian_write<false>(view, view_size);
443 }
444
445 // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
446 // instruction template.
447 virtual uint16_t
448 do_thumb16_special(size_t)
449 { gold_unreachable(); }
450
451 private:
452 // A template to implement do_write.
453 template<bool big_endian>
454 void inline
455 do_fixed_endian_write(unsigned char*, section_size_type);
456
457 // Its template.
458 const Stub_template* stub_template_;
459 // Offset within the section of containing this stub.
460 section_offset_type offset_;
461 };
462
463 // Reloc stub class. These are stubs we use to fix up relocation because
464 // of limited branch ranges.
465
466 class Reloc_stub : public Stub
467 {
468 public:
469 static const unsigned int invalid_index = static_cast<unsigned int>(-1);
470 // We assume we never jump to this address.
471 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
472
473 // Return destination address.
474 Arm_address
475 destination_address() const
476 {
477 gold_assert(this->destination_address_ != this->invalid_address);
478 return this->destination_address_;
479 }
480
481 // Set destination address.
482 void
483 set_destination_address(Arm_address address)
484 {
485 gold_assert(address != this->invalid_address);
486 this->destination_address_ = address;
487 }
488
489 // Reset destination address.
490 void
491 reset_destination_address()
492 { this->destination_address_ = this->invalid_address; }
493
494 // Determine stub type for a branch of a relocation of R_TYPE going
495 // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set,
496 // the branch target is a thumb instruction. TARGET is used for look
497 // up ARM-specific linker settings.
498 static Stub_type
499 stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
500 Arm_address branch_target, bool target_is_thumb);
501
502 // Reloc_stub key. A key is logically a triplet of a stub type, a symbol
503 // and an addend. Since we treat global and local symbol differently, we
504 // use a Symbol object for a global symbol and a object-index pair for
505 // a local symbol.
506 class Key
507 {
508 public:
509 // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
510 // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL
511 // and R_SYM must not be invalid_index.
512 Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
513 unsigned int r_sym, int32_t addend)
514 : stub_type_(stub_type), addend_(addend)
515 {
516 if (symbol != NULL)
517 {
518 this->r_sym_ = Reloc_stub::invalid_index;
519 this->u_.symbol = symbol;
520 }
521 else
522 {
523 gold_assert(relobj != NULL && r_sym != invalid_index);
524 this->r_sym_ = r_sym;
525 this->u_.relobj = relobj;
526 }
527 }
528
529 ~Key()
530 { }
531
532 // Accessors: Keys are meant to be read-only object so no modifiers are
533 // provided.
534
535 // Return stub type.
536 Stub_type
537 stub_type() const
538 { return this->stub_type_; }
539
540 // Return the local symbol index or invalid_index.
541 unsigned int
542 r_sym() const
543 { return this->r_sym_; }
544
545 // Return the symbol if there is one.
546 const Symbol*
547 symbol() const
548 { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
549
550 // Return the relobj if there is one.
551 const Relobj*
552 relobj() const
553 { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
554
555 // Whether this equals to another key k.
556 bool
557 eq(const Key& k) const
558 {
559 return ((this->stub_type_ == k.stub_type_)
560 && (this->r_sym_ == k.r_sym_)
561 && ((this->r_sym_ != Reloc_stub::invalid_index)
562 ? (this->u_.relobj == k.u_.relobj)
563 : (this->u_.symbol == k.u_.symbol))
564 && (this->addend_ == k.addend_));
565 }
566
567 // Return a hash value.
568 size_t
569 hash_value() const
570 {
571 return (this->stub_type_
572 ^ this->r_sym_
573 ^ gold::string_hash<char>(
574 (this->r_sym_ != Reloc_stub::invalid_index)
575 ? this->u_.relobj->name().c_str()
576 : this->u_.symbol->name())
577 ^ this->addend_);
578 }
579
580 // Functors for STL associative containers.
581 struct hash
582 {
583 size_t
584 operator()(const Key& k) const
585 { return k.hash_value(); }
586 };
587
588 struct equal_to
589 {
590 bool
591 operator()(const Key& k1, const Key& k2) const
592 { return k1.eq(k2); }
593 };
594
595 // Name of key. This is mainly for debugging.
596 std::string
597 name() const;
598
599 private:
600 // Stub type.
601 Stub_type stub_type_;
602 // If this is a local symbol, this is the index in the defining object.
603 // Otherwise, it is invalid_index for a global symbol.
604 unsigned int r_sym_;
605 // If r_sym_ is an invalid index, this points to a global symbol.
606 // Otherwise, it points to a relobj. We used the unsized and target
607 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
608 // Arm_relobj, in order to avoid making the stub class a template
609 // as most of the stub machinery is endianness-neutral. However, it
610 // may require a bit of casting done by users of this class.
611 union
612 {
613 const Symbol* symbol;
614 const Relobj* relobj;
615 } u_;
616 // Addend associated with a reloc.
617 int32_t addend_;
618 };
619
620 protected:
621 // Reloc_stubs are created via a stub factory. So these are protected.
622 Reloc_stub(const Stub_template* stub_template)
623 : Stub(stub_template), destination_address_(invalid_address)
624 { }
625
626 ~Reloc_stub()
627 { }
628
629 friend class Stub_factory;
630
631 // Return the relocation target address of the i-th relocation in the
632 // stub.
633 Arm_address
634 do_reloc_target(size_t i)
635 {
636 // All reloc stub have only one relocation.
637 gold_assert(i == 0);
638 return this->destination_address_;
639 }
640
641 private:
642 // Address of destination.
643 Arm_address destination_address_;
644 };
645
646 // Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit
647 // THUMB branch that meets the following conditions:
648 //
649 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
650 // branch address is 0xffe.
651 // 2. The branch target address is in the same page as the first word of the
652 // branch.
653 // 3. The branch follows a 32-bit instruction which is not a branch.
654 //
655 // To do the fix up, we need to store the address of the branch instruction
656 // and its target at least. We also need to store the original branch
657 // instruction bits for the condition code in a conditional branch. The
658 // condition code is used in a special instruction template. We also want
659 // to identify input sections needing Cortex-A8 workaround quickly. We store
660 // extra information about object and section index of the code section
661 // containing a branch being fixed up. The information is used to mark
662 // the code section when we finalize the Cortex-A8 stubs.
663 //
664
665 class Cortex_a8_stub : public Stub
666 {
667 public:
668 ~Cortex_a8_stub()
669 { }
670
671 // Return the object of the code section containing the branch being fixed
672 // up.
673 Relobj*
674 relobj() const
675 { return this->relobj_; }
676
677 // Return the section index of the code section containing the branch being
678 // fixed up.
679 unsigned int
680 shndx() const
681 { return this->shndx_; }
682
683 // Return the source address of stub. This is the address of the original
684 // branch instruction. LSB is 1 always set to indicate that it is a THUMB
685 // instruction.
686 Arm_address
687 source_address() const
688 { return this->source_address_; }
689
690 // Return the destination address of the stub. This is the branch taken
691 // address of the original branch instruction. LSB is 1 if it is a THUMB
692 // instruction address.
693 Arm_address
694 destination_address() const
695 { return this->destination_address_; }
696
697 // Return the instruction being fixed up.
698 uint32_t
699 original_insn() const
700 { return this->original_insn_; }
701
702 protected:
703 // Cortex_a8_stubs are created via a stub factory. So these are protected.
704 Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
705 unsigned int shndx, Arm_address source_address,
706 Arm_address destination_address, uint32_t original_insn)
707 : Stub(stub_template), relobj_(relobj), shndx_(shndx),
708 source_address_(source_address | 1U),
709 destination_address_(destination_address),
710 original_insn_(original_insn)
711 { }
712
713 friend class Stub_factory;
714
715 // Return the relocation target address of the i-th relocation in the
716 // stub.
717 Arm_address
718 do_reloc_target(size_t i)
719 {
720 if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
721 {
722 // The conditional branch veneer has two relocations.
723 gold_assert(i < 2);
724 return i == 0 ? this->source_address_ + 4 : this->destination_address_;
725 }
726 else
727 {
728 // All other Cortex-A8 stubs have only one relocation.
729 gold_assert(i == 0);
730 return this->destination_address_;
731 }
732 }
733
734 // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
735 uint16_t
736 do_thumb16_special(size_t);
737
738 private:
739 // Object of the code section containing the branch being fixed up.
740 Relobj* relobj_;
741 // Section index of the code section containing the branch begin fixed up.
742 unsigned int shndx_;
743 // Source address of original branch.
744 Arm_address source_address_;
745 // Destination address of the original branch.
746 Arm_address destination_address_;
747 // Original branch instruction. This is needed for copying the condition
748 // code from a condition branch to its stub.
749 uint32_t original_insn_;
750 };
751
752 // ARMv4 BX Rx branch relocation stub class.
753 class Arm_v4bx_stub : public Stub
754 {
755 public:
756 ~Arm_v4bx_stub()
757 { }
758
759 // Return the associated register.
760 uint32_t
761 reg() const
762 { return this->reg_; }
763
764 protected:
765 // Arm V4BX stubs are created via a stub factory. So these are protected.
766 Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
767 : Stub(stub_template), reg_(reg)
768 { }
769
770 friend class Stub_factory;
771
772 // Return the relocation target address of the i-th relocation in the
773 // stub.
774 Arm_address
775 do_reloc_target(size_t)
776 { gold_unreachable(); }
777
778 // This may be overridden in the child class.
779 virtual void
780 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
781 {
782 if (big_endian)
783 this->do_fixed_endian_v4bx_write<true>(view, view_size);
784 else
785 this->do_fixed_endian_v4bx_write<false>(view, view_size);
786 }
787
788 private:
789 // A template to implement do_write.
790 template<bool big_endian>
791 void inline
792 do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
793 {
794 const Insn_template* insns = this->stub_template()->insns();
795 elfcpp::Swap<32, big_endian>::writeval(view,
796 (insns[0].data()
797 + (this->reg_ << 16)));
798 view += insns[0].size();
799 elfcpp::Swap<32, big_endian>::writeval(view,
800 (insns[1].data() + this->reg_));
801 view += insns[1].size();
802 elfcpp::Swap<32, big_endian>::writeval(view,
803 (insns[2].data() + this->reg_));
804 }
805
806 // A register index (r0-r14), which is associated with the stub.
807 uint32_t reg_;
808 };
809
810 // Stub factory class.
811
812 class Stub_factory
813 {
814 public:
815 // Return the unique instance of this class.
816 static const Stub_factory&
817 get_instance()
818 {
819 static Stub_factory singleton;
820 return singleton;
821 }
822
823 // Make a relocation stub.
824 Reloc_stub*
825 make_reloc_stub(Stub_type stub_type) const
826 {
827 gold_assert(stub_type >= arm_stub_reloc_first
828 && stub_type <= arm_stub_reloc_last);
829 return new Reloc_stub(this->stub_templates_[stub_type]);
830 }
831
832 // Make a Cortex-A8 stub.
833 Cortex_a8_stub*
834 make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
835 Arm_address source, Arm_address destination,
836 uint32_t original_insn) const
837 {
838 gold_assert(stub_type >= arm_stub_cortex_a8_first
839 && stub_type <= arm_stub_cortex_a8_last);
840 return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
841 source, destination, original_insn);
842 }
843
844 // Make an ARM V4BX relocation stub.
845 // This method creates a stub from the arm_stub_v4_veneer_bx template only.
846 Arm_v4bx_stub*
847 make_arm_v4bx_stub(uint32_t reg) const
848 {
849 gold_assert(reg < 0xf);
850 return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
851 reg);
852 }
853
854 private:
855 // Constructor and destructor are protected since we only return a single
856 // instance created in Stub_factory::get_instance().
857
858 Stub_factory();
859
860 // A Stub_factory may not be copied since it is a singleton.
861 Stub_factory(const Stub_factory&);
862 Stub_factory& operator=(Stub_factory&);
863
864 // Stub templates. These are initialized in the constructor.
865 const Stub_template* stub_templates_[arm_stub_type_last+1];
866 };
867
868 // A class to hold stubs for the ARM target.
869
870 template<bool big_endian>
871 class Stub_table : public Output_data
872 {
873 public:
874 Stub_table(Arm_input_section<big_endian>* owner)
875 : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
876 reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
877 prev_data_size_(0), prev_addralign_(1)
878 { }
879
880 ~Stub_table()
881 { }
882
883 // Owner of this stub table.
884 Arm_input_section<big_endian>*
885 owner() const
886 { return this->owner_; }
887
888 // Whether this stub table is empty.
889 bool
890 empty() const
891 {
892 return (this->reloc_stubs_.empty()
893 && this->cortex_a8_stubs_.empty()
894 && this->arm_v4bx_stubs_.empty());
895 }
896
897 // Return the current data size.
898 off_t
899 current_data_size() const
900 { return this->current_data_size_for_child(); }
901
902 // Add a STUB using KEY. The caller is responsible for avoiding addition
903 // if a STUB with the same key has already been added.
904 void
905 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
906 {
907 const Stub_template* stub_template = stub->stub_template();
908 gold_assert(stub_template->type() == key.stub_type());
909 this->reloc_stubs_[key] = stub;
910
911 // Assign stub offset early. We can do this because we never remove
912 // reloc stubs and they are in the beginning of the stub table.
913 uint64_t align = stub_template->alignment();
914 this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
915 stub->set_offset(this->reloc_stubs_size_);
916 this->reloc_stubs_size_ += stub_template->size();
917 this->reloc_stubs_addralign_ =
918 std::max(this->reloc_stubs_addralign_, align);
919 }
920
921 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
922 // The caller is responsible for avoiding addition if a STUB with the same
923 // address has already been added.
924 void
925 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
926 {
927 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
928 this->cortex_a8_stubs_.insert(value);
929 }
930
931 // Add an ARM V4BX relocation stub. A register index will be retrieved
932 // from the stub.
933 void
934 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
935 {
936 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
937 this->arm_v4bx_stubs_[stub->reg()] = stub;
938 }
939
940 // Remove all Cortex-A8 stubs.
941 void
942 remove_all_cortex_a8_stubs();
943
944 // Look up a relocation stub using KEY. Return NULL if there is none.
945 Reloc_stub*
946 find_reloc_stub(const Reloc_stub::Key& key) const
947 {
948 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
949 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
950 }
951
952 // Look up an arm v4bx relocation stub using the register index.
953 // Return NULL if there is none.
954 Arm_v4bx_stub*
955 find_arm_v4bx_stub(const uint32_t reg) const
956 {
957 gold_assert(reg < 0xf);
958 return this->arm_v4bx_stubs_[reg];
959 }
960
961 // Relocate stubs in this stub table.
962 void
963 relocate_stubs(const Relocate_info<32, big_endian>*,
964 Target_arm<big_endian>*, Output_section*,
965 unsigned char*, Arm_address, section_size_type);
966
967 // Update data size and alignment at the end of a relaxation pass. Return
968 // true if either data size or alignment is different from that of the
969 // previous relaxation pass.
970 bool
971 update_data_size_and_addralign();
972
973 // Finalize stubs. Set the offsets of all stubs and mark input sections
974 // needing the Cortex-A8 workaround.
975 void
976 finalize_stubs();
977
978 // Apply Cortex-A8 workaround to an address range.
979 void
980 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
981 unsigned char*, Arm_address,
982 section_size_type);
983
984 protected:
985 // Write out section contents.
986 void
987 do_write(Output_file*);
988
989 // Return the required alignment.
990 uint64_t
991 do_addralign() const
992 { return this->prev_addralign_; }
993
994 // Reset address and file offset.
995 void
996 do_reset_address_and_file_offset()
997 { this->set_current_data_size_for_child(this->prev_data_size_); }
998
999 // Set final data size.
1000 void
1001 set_final_data_size()
1002 { this->set_data_size(this->current_data_size()); }
1003
1004 private:
1005 // Relocate one stub.
1006 void
1007 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1008 Target_arm<big_endian>*, Output_section*,
1009 unsigned char*, Arm_address, section_size_type);
1010
1011 // Unordered map of relocation stubs.
1012 typedef
1013 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1014 Reloc_stub::Key::equal_to>
1015 Reloc_stub_map;
1016
1017 // List of Cortex-A8 stubs ordered by addresses of branches being
1018 // fixed up in output.
1019 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1020 // List of Arm V4BX relocation stubs ordered by associated registers.
1021 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1022
1023 // Owner of this stub table.
1024 Arm_input_section<big_endian>* owner_;
1025 // The relocation stubs.
1026 Reloc_stub_map reloc_stubs_;
1027 // Size of reloc stubs.
1028 off_t reloc_stubs_size_;
1029 // Maximum address alignment of reloc stubs.
1030 uint64_t reloc_stubs_addralign_;
1031 // The cortex_a8_stubs.
1032 Cortex_a8_stub_list cortex_a8_stubs_;
1033 // The Arm V4BX relocation stubs.
1034 Arm_v4bx_stub_list arm_v4bx_stubs_;
1035 // data size of this in the previous pass.
1036 off_t prev_data_size_;
1037 // address alignment of this in the previous pass.
1038 uint64_t prev_addralign_;
1039 };
1040
1041 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1042 // we add to the end of an EXIDX input section that goes into the output.
1043
1044 class Arm_exidx_cantunwind : public Output_section_data
1045 {
1046 public:
1047 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1048 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1049 { }
1050
1051 // Return the object containing the section pointed by this.
1052 Relobj*
1053 relobj() const
1054 { return this->relobj_; }
1055
1056 // Return the section index of the section pointed by this.
1057 unsigned int
1058 shndx() const
1059 { return this->shndx_; }
1060
1061 protected:
1062 void
1063 do_write(Output_file* of)
1064 {
1065 if (parameters->target().is_big_endian())
1066 this->do_fixed_endian_write<true>(of);
1067 else
1068 this->do_fixed_endian_write<false>(of);
1069 }
1070
1071 // Write to a map file.
1072 void
1073 do_print_to_mapfile(Mapfile* mapfile) const
1074 { mapfile->print_output_data(this, _("** ARM cantunwind")); }
1075
1076 private:
1077 // Implement do_write for a given endianness.
1078 template<bool big_endian>
1079 void inline
1080 do_fixed_endian_write(Output_file*);
1081
1082 // The object containing the section pointed by this.
1083 Relobj* relobj_;
1084 // The section index of the section pointed by this.
1085 unsigned int shndx_;
1086 };
1087
1088 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1089 // Offset map is used to map input section offset within the EXIDX section
1090 // to the output offset from the start of this EXIDX section.
1091
1092 typedef std::map<section_offset_type, section_offset_type>
1093 Arm_exidx_section_offset_map;
1094
1095 // Arm_exidx_merged_section class. This represents an EXIDX input section
1096 // with some of its entries merged.
1097
1098 class Arm_exidx_merged_section : public Output_relaxed_input_section
1099 {
1100 public:
1101 // Constructor for Arm_exidx_merged_section.
1102 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1103 // SECTION_OFFSET_MAP points to a section offset map describing how
1104 // parts of the input section are mapped to output. DELETED_BYTES is
1105 // the number of bytes deleted from the EXIDX input section.
1106 Arm_exidx_merged_section(
1107 const Arm_exidx_input_section& exidx_input_section,
1108 const Arm_exidx_section_offset_map& section_offset_map,
1109 uint32_t deleted_bytes);
1110
1111 // Build output contents.
1112 void
1113 build_contents(const unsigned char*, section_size_type);
1114
1115 // Return the original EXIDX input section.
1116 const Arm_exidx_input_section&
1117 exidx_input_section() const
1118 { return this->exidx_input_section_; }
1119
1120 // Return the section offset map.
1121 const Arm_exidx_section_offset_map&
1122 section_offset_map() const
1123 { return this->section_offset_map_; }
1124
1125 protected:
1126 // Write merged section into file OF.
1127 void
1128 do_write(Output_file* of);
1129
1130 bool
1131 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1132 section_offset_type*) const;
1133
1134 private:
1135 // Original EXIDX input section.
1136 const Arm_exidx_input_section& exidx_input_section_;
1137 // Section offset map.
1138 const Arm_exidx_section_offset_map& section_offset_map_;
1139 // Merged section contents. We need to keep build the merged section
1140 // and save it here to avoid accessing the original EXIDX section when
1141 // we cannot lock the sections' object.
1142 unsigned char* section_contents_;
1143 };
1144
1145 // A class to wrap an ordinary input section containing executable code.
1146
1147 template<bool big_endian>
1148 class Arm_input_section : public Output_relaxed_input_section
1149 {
1150 public:
1151 Arm_input_section(Relobj* relobj, unsigned int shndx)
1152 : Output_relaxed_input_section(relobj, shndx, 1),
1153 original_addralign_(1), original_size_(0), stub_table_(NULL),
1154 original_contents_(NULL)
1155 { }
1156
1157 ~Arm_input_section()
1158 { delete[] this->original_contents_; }
1159
1160 // Initialize.
1161 void
1162 init();
1163
1164 // Whether this is a stub table owner.
1165 bool
1166 is_stub_table_owner() const
1167 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1168
1169 // Return the stub table.
1170 Stub_table<big_endian>*
1171 stub_table() const
1172 { return this->stub_table_; }
1173
1174 // Set the stub_table.
1175 void
1176 set_stub_table(Stub_table<big_endian>* stub_table)
1177 { this->stub_table_ = stub_table; }
1178
1179 // Downcast a base pointer to an Arm_input_section pointer. This is
1180 // not type-safe but we only use Arm_input_section not the base class.
1181 static Arm_input_section<big_endian>*
1182 as_arm_input_section(Output_relaxed_input_section* poris)
1183 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1184
1185 // Return the original size of the section.
1186 uint32_t
1187 original_size() const
1188 { return this->original_size_; }
1189
1190 protected:
1191 // Write data to output file.
1192 void
1193 do_write(Output_file*);
1194
1195 // Return required alignment of this.
1196 uint64_t
1197 do_addralign() const
1198 {
1199 if (this->is_stub_table_owner())
1200 return std::max(this->stub_table_->addralign(),
1201 static_cast<uint64_t>(this->original_addralign_));
1202 else
1203 return this->original_addralign_;
1204 }
1205
1206 // Finalize data size.
1207 void
1208 set_final_data_size();
1209
1210 // Reset address and file offset.
1211 void
1212 do_reset_address_and_file_offset();
1213
1214 // Output offset.
1215 bool
1216 do_output_offset(const Relobj* object, unsigned int shndx,
1217 section_offset_type offset,
1218 section_offset_type* poutput) const
1219 {
1220 if ((object == this->relobj())
1221 && (shndx == this->shndx())
1222 && (offset >= 0)
1223 && (offset <=
1224 convert_types<section_offset_type, uint32_t>(this->original_size_)))
1225 {
1226 *poutput = offset;
1227 return true;
1228 }
1229 else
1230 return false;
1231 }
1232
1233 private:
1234 // Copying is not allowed.
1235 Arm_input_section(const Arm_input_section&);
1236 Arm_input_section& operator=(const Arm_input_section&);
1237
1238 // Address alignment of the original input section.
1239 uint32_t original_addralign_;
1240 // Section size of the original input section.
1241 uint32_t original_size_;
1242 // Stub table.
1243 Stub_table<big_endian>* stub_table_;
1244 // Original section contents. We have to make a copy here since the file
1245 // containing the original section may not be locked when we need to access
1246 // the contents.
1247 unsigned char* original_contents_;
1248 };
1249
1250 // Arm_exidx_fixup class. This is used to define a number of methods
1251 // and keep states for fixing up EXIDX coverage.
1252
1253 class Arm_exidx_fixup
1254 {
1255 public:
1256 Arm_exidx_fixup(Output_section* exidx_output_section,
1257 bool merge_exidx_entries = true)
1258 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1259 last_inlined_entry_(0), last_input_section_(NULL),
1260 section_offset_map_(NULL), first_output_text_section_(NULL),
1261 merge_exidx_entries_(merge_exidx_entries)
1262 { }
1263
1264 ~Arm_exidx_fixup()
1265 { delete this->section_offset_map_; }
1266
1267 // Process an EXIDX section for entry merging. SECTION_CONTENTS points
1268 // to the EXIDX contents and SECTION_SIZE is the size of the contents. Return
1269 // number of bytes to be deleted in output. If parts of the input EXIDX
1270 // section are merged a heap allocated Arm_exidx_section_offset_map is store
1271 // in the located PSECTION_OFFSET_MAP. The caller owns the map and is
1272 // responsible for releasing it.
1273 template<bool big_endian>
1274 uint32_t
1275 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1276 const unsigned char* section_contents,
1277 section_size_type section_size,
1278 Arm_exidx_section_offset_map** psection_offset_map);
1279
1280 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1281 // input section, if there is not one already.
1282 void
1283 add_exidx_cantunwind_as_needed();
1284
1285 // Return the output section for the text section which is linked to the
1286 // first exidx input in output.
1287 Output_section*
1288 first_output_text_section() const
1289 { return this->first_output_text_section_; }
1290
1291 private:
1292 // Copying is not allowed.
1293 Arm_exidx_fixup(const Arm_exidx_fixup&);
1294 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1295
1296 // Type of EXIDX unwind entry.
1297 enum Unwind_type
1298 {
1299 // No type.
1300 UT_NONE,
1301 // EXIDX_CANTUNWIND.
1302 UT_EXIDX_CANTUNWIND,
1303 // Inlined entry.
1304 UT_INLINED_ENTRY,
1305 // Normal entry.
1306 UT_NORMAL_ENTRY,
1307 };
1308
1309 // Process an EXIDX entry. We only care about the second word of the
1310 // entry. Return true if the entry can be deleted.
1311 bool
1312 process_exidx_entry(uint32_t second_word);
1313
1314 // Update the current section offset map during EXIDX section fix-up.
1315 // If there is no map, create one. INPUT_OFFSET is the offset of a
1316 // reference point, DELETED_BYTES is the number of deleted by in the
1317 // section so far. If DELETE_ENTRY is true, the reference point and
1318 // all offsets after the previous reference point are discarded.
1319 void
1320 update_offset_map(section_offset_type input_offset,
1321 section_size_type deleted_bytes, bool delete_entry);
1322
1323 // EXIDX output section.
1324 Output_section* exidx_output_section_;
1325 // Unwind type of the last EXIDX entry processed.
1326 Unwind_type last_unwind_type_;
1327 // Last seen inlined EXIDX entry.
1328 uint32_t last_inlined_entry_;
1329 // Last processed EXIDX input section.
1330 const Arm_exidx_input_section* last_input_section_;
1331 // Section offset map created in process_exidx_section.
1332 Arm_exidx_section_offset_map* section_offset_map_;
1333 // Output section for the text section which is linked to the first exidx
1334 // input in output.
1335 Output_section* first_output_text_section_;
1336
1337 bool merge_exidx_entries_;
1338 };
1339
1340 // Arm output section class. This is defined mainly to add a number of
1341 // stub generation methods.
1342
1343 template<bool big_endian>
1344 class Arm_output_section : public Output_section
1345 {
1346 public:
1347 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1348
1349 // We need to force SHF_LINK_ORDER in a SHT_ARM_EXIDX section.
1350 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1351 elfcpp::Elf_Xword flags)
1352 : Output_section(name, type,
1353 (type == elfcpp::SHT_ARM_EXIDX
1354 ? flags | elfcpp::SHF_LINK_ORDER
1355 : flags))
1356 {
1357 if (type == elfcpp::SHT_ARM_EXIDX)
1358 this->set_always_keeps_input_sections();
1359 }
1360
1361 ~Arm_output_section()
1362 { }
1363
1364 // Group input sections for stub generation.
1365 void
1366 group_sections(section_size_type, bool, Target_arm<big_endian>*, const Task*);
1367
1368 // Downcast a base pointer to an Arm_output_section pointer. This is
1369 // not type-safe but we only use Arm_output_section not the base class.
1370 static Arm_output_section<big_endian>*
1371 as_arm_output_section(Output_section* os)
1372 { return static_cast<Arm_output_section<big_endian>*>(os); }
1373
1374 // Append all input text sections in this into LIST.
1375 void
1376 append_text_sections_to_list(Text_section_list* list);
1377
1378 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1379 // is a list of text input sections sorted in ascending order of their
1380 // output addresses.
1381 void
1382 fix_exidx_coverage(Layout* layout,
1383 const Text_section_list& sorted_text_section,
1384 Symbol_table* symtab,
1385 bool merge_exidx_entries,
1386 const Task* task);
1387
1388 // Link an EXIDX section into its corresponding text section.
1389 void
1390 set_exidx_section_link();
1391
1392 private:
1393 // For convenience.
1394 typedef Output_section::Input_section Input_section;
1395 typedef Output_section::Input_section_list Input_section_list;
1396
1397 // Create a stub group.
1398 void create_stub_group(Input_section_list::const_iterator,
1399 Input_section_list::const_iterator,
1400 Input_section_list::const_iterator,
1401 Target_arm<big_endian>*,
1402 std::vector<Output_relaxed_input_section*>*,
1403 const Task* task);
1404 };
1405
1406 // Arm_exidx_input_section class. This represents an EXIDX input section.
1407
1408 class Arm_exidx_input_section
1409 {
1410 public:
1411 static const section_offset_type invalid_offset =
1412 static_cast<section_offset_type>(-1);
1413
1414 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1415 unsigned int link, uint32_t size,
1416 uint32_t addralign, uint32_t text_size)
1417 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1418 addralign_(addralign), text_size_(text_size), has_errors_(false)
1419 { }
1420
1421 ~Arm_exidx_input_section()
1422 { }
1423
1424 // Accessors: This is a read-only class.
1425
1426 // Return the object containing this EXIDX input section.
1427 Relobj*
1428 relobj() const
1429 { return this->relobj_; }
1430
1431 // Return the section index of this EXIDX input section.
1432 unsigned int
1433 shndx() const
1434 { return this->shndx_; }
1435
1436 // Return the section index of linked text section in the same object.
1437 unsigned int
1438 link() const
1439 { return this->link_; }
1440
1441 // Return size of the EXIDX input section.
1442 uint32_t
1443 size() const
1444 { return this->size_; }
1445
1446 // Return address alignment of EXIDX input section.
1447 uint32_t
1448 addralign() const
1449 { return this->addralign_; }
1450
1451 // Return size of the associated text input section.
1452 uint32_t
1453 text_size() const
1454 { return this->text_size_; }
1455
1456 // Whether there are any errors in the EXIDX input section.
1457 bool
1458 has_errors() const
1459 { return this->has_errors_; }
1460
1461 // Set has-errors flag.
1462 void
1463 set_has_errors()
1464 { this->has_errors_ = true; }
1465
1466 private:
1467 // Object containing this.
1468 Relobj* relobj_;
1469 // Section index of this.
1470 unsigned int shndx_;
1471 // text section linked to this in the same object.
1472 unsigned int link_;
1473 // Size of this. For ARM 32-bit is sufficient.
1474 uint32_t size_;
1475 // Address alignment of this. For ARM 32-bit is sufficient.
1476 uint32_t addralign_;
1477 // Size of associated text section.
1478 uint32_t text_size_;
1479 // Whether this has any errors.
1480 bool has_errors_;
1481 };
1482
1483 // Arm_relobj class.
1484
1485 template<bool big_endian>
1486 class Arm_relobj : public Sized_relobj_file<32, big_endian>
1487 {
1488 public:
1489 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1490
1491 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1492 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1493 : Sized_relobj_file<32, big_endian>(name, input_file, offset, ehdr),
1494 stub_tables_(), local_symbol_is_thumb_function_(),
1495 attributes_section_data_(NULL), mapping_symbols_info_(),
1496 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1497 output_local_symbol_count_needs_update_(false),
1498 merge_flags_and_attributes_(true)
1499 { }
1500
1501 ~Arm_relobj()
1502 { delete this->attributes_section_data_; }
1503
1504 // Return the stub table of the SHNDX-th section if there is one.
1505 Stub_table<big_endian>*
1506 stub_table(unsigned int shndx) const
1507 {
1508 gold_assert(shndx < this->stub_tables_.size());
1509 return this->stub_tables_[shndx];
1510 }
1511
1512 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1513 void
1514 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1515 {
1516 gold_assert(shndx < this->stub_tables_.size());
1517 this->stub_tables_[shndx] = stub_table;
1518 }
1519
1520 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1521 // index. This is only valid after do_count_local_symbol is called.
1522 bool
1523 local_symbol_is_thumb_function(unsigned int r_sym) const
1524 {
1525 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1526 return this->local_symbol_is_thumb_function_[r_sym];
1527 }
1528
1529 // Scan all relocation sections for stub generation.
1530 void
1531 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1532 const Layout*);
1533
1534 // Convert regular input section with index SHNDX to a relaxed section.
1535 void
1536 convert_input_section_to_relaxed_section(unsigned shndx)
1537 {
1538 // The stubs have relocations and we need to process them after writing
1539 // out the stubs. So relocation now must follow section write.
1540 this->set_section_offset(shndx, -1ULL);
1541 this->set_relocs_must_follow_section_writes();
1542 }
1543
1544 // Downcast a base pointer to an Arm_relobj pointer. This is
1545 // not type-safe but we only use Arm_relobj not the base class.
1546 static Arm_relobj<big_endian>*
1547 as_arm_relobj(Relobj* relobj)
1548 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1549
1550 // Processor-specific flags in ELF file header. This is valid only after
1551 // reading symbols.
1552 elfcpp::Elf_Word
1553 processor_specific_flags() const
1554 { return this->processor_specific_flags_; }
1555
1556 // Attribute section data This is the contents of the .ARM.attribute section
1557 // if there is one.
1558 const Attributes_section_data*
1559 attributes_section_data() const
1560 { return this->attributes_section_data_; }
1561
1562 // Mapping symbol location.
1563 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1564
1565 // Functor for STL container.
1566 struct Mapping_symbol_position_less
1567 {
1568 bool
1569 operator()(const Mapping_symbol_position& p1,
1570 const Mapping_symbol_position& p2) const
1571 {
1572 return (p1.first < p2.first
1573 || (p1.first == p2.first && p1.second < p2.second));
1574 }
1575 };
1576
1577 // We only care about the first character of a mapping symbol, so
1578 // we only store that instead of the whole symbol name.
1579 typedef std::map<Mapping_symbol_position, char,
1580 Mapping_symbol_position_less> Mapping_symbols_info;
1581
1582 // Whether a section contains any Cortex-A8 workaround.
1583 bool
1584 section_has_cortex_a8_workaround(unsigned int shndx) const
1585 {
1586 return (this->section_has_cortex_a8_workaround_ != NULL
1587 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1588 }
1589
1590 // Mark a section that has Cortex-A8 workaround.
1591 void
1592 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1593 {
1594 if (this->section_has_cortex_a8_workaround_ == NULL)
1595 this->section_has_cortex_a8_workaround_ =
1596 new std::vector<bool>(this->shnum(), false);
1597 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1598 }
1599
1600 // Return the EXIDX section of an text section with index SHNDX or NULL
1601 // if the text section has no associated EXIDX section.
1602 const Arm_exidx_input_section*
1603 exidx_input_section_by_link(unsigned int shndx) const
1604 {
1605 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1606 return ((p != this->exidx_section_map_.end()
1607 && p->second->link() == shndx)
1608 ? p->second
1609 : NULL);
1610 }
1611
1612 // Return the EXIDX section with index SHNDX or NULL if there is none.
1613 const Arm_exidx_input_section*
1614 exidx_input_section_by_shndx(unsigned shndx) const
1615 {
1616 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1617 return ((p != this->exidx_section_map_.end()
1618 && p->second->shndx() == shndx)
1619 ? p->second
1620 : NULL);
1621 }
1622
1623 // Whether output local symbol count needs updating.
1624 bool
1625 output_local_symbol_count_needs_update() const
1626 { return this->output_local_symbol_count_needs_update_; }
1627
1628 // Set output_local_symbol_count_needs_update flag to be true.
1629 void
1630 set_output_local_symbol_count_needs_update()
1631 { this->output_local_symbol_count_needs_update_ = true; }
1632
1633 // Update output local symbol count at the end of relaxation.
1634 void
1635 update_output_local_symbol_count();
1636
1637 // Whether we want to merge processor-specific flags and attributes.
1638 bool
1639 merge_flags_and_attributes() const
1640 { return this->merge_flags_and_attributes_; }
1641
1642 // Export list of EXIDX section indices.
1643 void
1644 get_exidx_shndx_list(std::vector<unsigned int>* list) const
1645 {
1646 list->clear();
1647 for (Exidx_section_map::const_iterator p = this->exidx_section_map_.begin();
1648 p != this->exidx_section_map_.end();
1649 ++p)
1650 {
1651 if (p->second->shndx() == p->first)
1652 list->push_back(p->first);
1653 }
1654 // Sort list to make result independent of implementation of map.
1655 std::sort(list->begin(), list->end());
1656 }
1657
1658 protected:
1659 // Post constructor setup.
1660 void
1661 do_setup()
1662 {
1663 // Call parent's setup method.
1664 Sized_relobj_file<32, big_endian>::do_setup();
1665
1666 // Initialize look-up tables.
1667 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1668 this->stub_tables_.swap(empty_stub_table_list);
1669 }
1670
1671 // Count the local symbols.
1672 void
1673 do_count_local_symbols(Stringpool_template<char>*,
1674 Stringpool_template<char>*);
1675
1676 void
1677 do_relocate_sections(
1678 const Symbol_table* symtab, const Layout* layout,
1679 const unsigned char* pshdrs, Output_file* of,
1680 typename Sized_relobj_file<32, big_endian>::Views* pivews);
1681
1682 // Read the symbol information.
1683 void
1684 do_read_symbols(Read_symbols_data* sd);
1685
1686 // Process relocs for garbage collection.
1687 void
1688 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1689
1690 private:
1691
1692 // Whether a section needs to be scanned for relocation stubs.
1693 bool
1694 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1695 const Relobj::Output_sections&,
1696 const Symbol_table*, const unsigned char*);
1697
1698 // Whether a section is a scannable text section.
1699 bool
1700 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1701 const Output_section*, const Symbol_table*);
1702
1703 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1704 bool
1705 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1706 unsigned int, Output_section*,
1707 const Symbol_table*);
1708
1709 // Scan a section for the Cortex-A8 erratum.
1710 void
1711 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1712 unsigned int, Output_section*,
1713 Target_arm<big_endian>*);
1714
1715 // Find the linked text section of an EXIDX section by looking at the
1716 // first relocation of the EXIDX section. PSHDR points to the section
1717 // headers of a relocation section and PSYMS points to the local symbols.
1718 // PSHNDX points to a location storing the text section index if found.
1719 // Return whether we can find the linked section.
1720 bool
1721 find_linked_text_section(const unsigned char* pshdr,
1722 const unsigned char* psyms, unsigned int* pshndx);
1723
1724 //
1725 // Make a new Arm_exidx_input_section object for EXIDX section with
1726 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1727 // index of the linked text section.
1728 void
1729 make_exidx_input_section(unsigned int shndx,
1730 const elfcpp::Shdr<32, big_endian>& shdr,
1731 unsigned int text_shndx,
1732 const elfcpp::Shdr<32, big_endian>& text_shdr);
1733
1734 // Return the output address of either a plain input section or a
1735 // relaxed input section. SHNDX is the section index.
1736 Arm_address
1737 simple_input_section_output_address(unsigned int, Output_section*);
1738
1739 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1740 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1741 Exidx_section_map;
1742
1743 // List of stub tables.
1744 Stub_table_list stub_tables_;
1745 // Bit vector to tell if a local symbol is a thumb function or not.
1746 // This is only valid after do_count_local_symbol is called.
1747 std::vector<bool> local_symbol_is_thumb_function_;
1748 // processor-specific flags in ELF file header.
1749 elfcpp::Elf_Word processor_specific_flags_;
1750 // Object attributes if there is an .ARM.attributes section or NULL.
1751 Attributes_section_data* attributes_section_data_;
1752 // Mapping symbols information.
1753 Mapping_symbols_info mapping_symbols_info_;
1754 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1755 std::vector<bool>* section_has_cortex_a8_workaround_;
1756 // Map a text section to its associated .ARM.exidx section, if there is one.
1757 Exidx_section_map exidx_section_map_;
1758 // Whether output local symbol count needs updating.
1759 bool output_local_symbol_count_needs_update_;
1760 // Whether we merge processor flags and attributes of this object to
1761 // output.
1762 bool merge_flags_and_attributes_;
1763 };
1764
1765 // Arm_dynobj class.
1766
1767 template<bool big_endian>
1768 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1769 {
1770 public:
1771 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1772 const elfcpp::Ehdr<32, big_endian>& ehdr)
1773 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1774 processor_specific_flags_(0), attributes_section_data_(NULL)
1775 { }
1776
1777 ~Arm_dynobj()
1778 { delete this->attributes_section_data_; }
1779
1780 // Downcast a base pointer to an Arm_relobj pointer. This is
1781 // not type-safe but we only use Arm_relobj not the base class.
1782 static Arm_dynobj<big_endian>*
1783 as_arm_dynobj(Dynobj* dynobj)
1784 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1785
1786 // Processor-specific flags in ELF file header. This is valid only after
1787 // reading symbols.
1788 elfcpp::Elf_Word
1789 processor_specific_flags() const
1790 { return this->processor_specific_flags_; }
1791
1792 // Attributes section data.
1793 const Attributes_section_data*
1794 attributes_section_data() const
1795 { return this->attributes_section_data_; }
1796
1797 protected:
1798 // Read the symbol information.
1799 void
1800 do_read_symbols(Read_symbols_data* sd);
1801
1802 private:
1803 // processor-specific flags in ELF file header.
1804 elfcpp::Elf_Word processor_specific_flags_;
1805 // Object attributes if there is an .ARM.attributes section or NULL.
1806 Attributes_section_data* attributes_section_data_;
1807 };
1808
1809 // Functor to read reloc addends during stub generation.
1810
1811 template<int sh_type, bool big_endian>
1812 struct Stub_addend_reader
1813 {
1814 // Return the addend for a relocation of a particular type. Depending
1815 // on whether this is a REL or RELA relocation, read the addend from a
1816 // view or from a Reloc object.
1817 elfcpp::Elf_types<32>::Elf_Swxword
1818 operator()(
1819 unsigned int /* r_type */,
1820 const unsigned char* /* view */,
1821 const typename Reloc_types<sh_type,
1822 32, big_endian>::Reloc& /* reloc */) const;
1823 };
1824
1825 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1826
1827 template<bool big_endian>
1828 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1829 {
1830 elfcpp::Elf_types<32>::Elf_Swxword
1831 operator()(
1832 unsigned int,
1833 const unsigned char*,
1834 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1835 };
1836
1837 // Specialized Stub_addend_reader for RELA type relocation sections.
1838 // We currently do not handle RELA type relocation sections but it is trivial
1839 // to implement the addend reader. This is provided for completeness and to
1840 // make it easier to add support for RELA relocation sections in the future.
1841
1842 template<bool big_endian>
1843 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1844 {
1845 elfcpp::Elf_types<32>::Elf_Swxword
1846 operator()(
1847 unsigned int,
1848 const unsigned char*,
1849 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1850 big_endian>::Reloc& reloc) const
1851 { return reloc.get_r_addend(); }
1852 };
1853
1854 // Cortex_a8_reloc class. We keep record of relocation that may need
1855 // the Cortex-A8 erratum workaround.
1856
1857 class Cortex_a8_reloc
1858 {
1859 public:
1860 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1861 Arm_address destination)
1862 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1863 { }
1864
1865 ~Cortex_a8_reloc()
1866 { }
1867
1868 // Accessors: This is a read-only class.
1869
1870 // Return the relocation stub associated with this relocation if there is
1871 // one.
1872 const Reloc_stub*
1873 reloc_stub() const
1874 { return this->reloc_stub_; }
1875
1876 // Return the relocation type.
1877 unsigned int
1878 r_type() const
1879 { return this->r_type_; }
1880
1881 // Return the destination address of the relocation. LSB stores the THUMB
1882 // bit.
1883 Arm_address
1884 destination() const
1885 { return this->destination_; }
1886
1887 private:
1888 // Associated relocation stub if there is one, or NULL.
1889 const Reloc_stub* reloc_stub_;
1890 // Relocation type.
1891 unsigned int r_type_;
1892 // Destination address of this relocation. LSB is used to distinguish
1893 // ARM/THUMB mode.
1894 Arm_address destination_;
1895 };
1896
1897 // Arm_output_data_got class. We derive this from Output_data_got to add
1898 // extra methods to handle TLS relocations in a static link.
1899
1900 template<bool big_endian>
1901 class Arm_output_data_got : public Output_data_got<32, big_endian>
1902 {
1903 public:
1904 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1905 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1906 { }
1907
1908 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1909 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1910 // applied in a static link.
1911 void
1912 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1913 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1914
1915 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1916 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1917 // relocation that needs to be applied in a static link.
1918 void
1919 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1920 Sized_relobj_file<32, big_endian>* relobj,
1921 unsigned int index)
1922 {
1923 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1924 index));
1925 }
1926
1927 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1928 // The first one is initialized to be 1, which is the module index for
1929 // the main executable and the second one 0. A reloc of the type
1930 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1931 // be applied by gold. GSYM is a global symbol.
1932 void
1933 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1934
1935 // Same as the above but for a local symbol in OBJECT with INDEX.
1936 void
1937 add_tls_gd32_with_static_reloc(unsigned int got_type,
1938 Sized_relobj_file<32, big_endian>* object,
1939 unsigned int index);
1940
1941 protected:
1942 // Write out the GOT table.
1943 void
1944 do_write(Output_file*);
1945
1946 private:
1947 // This class represent dynamic relocations that need to be applied by
1948 // gold because we are using TLS relocations in a static link.
1949 class Static_reloc
1950 {
1951 public:
1952 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1953 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1954 { this->u_.global.symbol = gsym; }
1955
1956 Static_reloc(unsigned int got_offset, unsigned int r_type,
1957 Sized_relobj_file<32, big_endian>* relobj, unsigned int index)
1958 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1959 {
1960 this->u_.local.relobj = relobj;
1961 this->u_.local.index = index;
1962 }
1963
1964 // Return the GOT offset.
1965 unsigned int
1966 got_offset() const
1967 { return this->got_offset_; }
1968
1969 // Relocation type.
1970 unsigned int
1971 r_type() const
1972 { return this->r_type_; }
1973
1974 // Whether the symbol is global or not.
1975 bool
1976 symbol_is_global() const
1977 { return this->symbol_is_global_; }
1978
1979 // For a relocation against a global symbol, the global symbol.
1980 Symbol*
1981 symbol() const
1982 {
1983 gold_assert(this->symbol_is_global_);
1984 return this->u_.global.symbol;
1985 }
1986
1987 // For a relocation against a local symbol, the defining object.
1988 Sized_relobj_file<32, big_endian>*
1989 relobj() const
1990 {
1991 gold_assert(!this->symbol_is_global_);
1992 return this->u_.local.relobj;
1993 }
1994
1995 // For a relocation against a local symbol, the local symbol index.
1996 unsigned int
1997 index() const
1998 {
1999 gold_assert(!this->symbol_is_global_);
2000 return this->u_.local.index;
2001 }
2002
2003 private:
2004 // GOT offset of the entry to which this relocation is applied.
2005 unsigned int got_offset_;
2006 // Type of relocation.
2007 unsigned int r_type_;
2008 // Whether this relocation is against a global symbol.
2009 bool symbol_is_global_;
2010 // A global or local symbol.
2011 union
2012 {
2013 struct
2014 {
2015 // For a global symbol, the symbol itself.
2016 Symbol* symbol;
2017 } global;
2018 struct
2019 {
2020 // For a local symbol, the object defining object.
2021 Sized_relobj_file<32, big_endian>* relobj;
2022 // For a local symbol, the symbol index.
2023 unsigned int index;
2024 } local;
2025 } u_;
2026 };
2027
2028 // Symbol table of the output object.
2029 Symbol_table* symbol_table_;
2030 // Layout of the output object.
2031 Layout* layout_;
2032 // Static relocs to be applied to the GOT.
2033 std::vector<Static_reloc> static_relocs_;
2034 };
2035
2036 // The ARM target has many relocation types with odd-sizes or noncontiguous
2037 // bits. The default handling of relocatable relocation cannot process these
2038 // relocations. So we have to extend the default code.
2039
2040 template<bool big_endian, int sh_type, typename Classify_reloc>
2041 class Arm_scan_relocatable_relocs :
2042 public Default_scan_relocatable_relocs<sh_type, Classify_reloc>
2043 {
2044 public:
2045 // Return the strategy to use for a local symbol which is a section
2046 // symbol, given the relocation type.
2047 inline Relocatable_relocs::Reloc_strategy
2048 local_section_strategy(unsigned int r_type, Relobj*)
2049 {
2050 if (sh_type == elfcpp::SHT_RELA)
2051 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_RELA;
2052 else
2053 {
2054 if (r_type == elfcpp::R_ARM_TARGET1
2055 || r_type == elfcpp::R_ARM_TARGET2)
2056 {
2057 const Target_arm<big_endian>* arm_target =
2058 Target_arm<big_endian>::default_target();
2059 r_type = arm_target->get_real_reloc_type(r_type);
2060 }
2061
2062 switch(r_type)
2063 {
2064 // Relocations that write nothing. These exclude R_ARM_TARGET1
2065 // and R_ARM_TARGET2.
2066 case elfcpp::R_ARM_NONE:
2067 case elfcpp::R_ARM_V4BX:
2068 case elfcpp::R_ARM_TLS_GOTDESC:
2069 case elfcpp::R_ARM_TLS_CALL:
2070 case elfcpp::R_ARM_TLS_DESCSEQ:
2071 case elfcpp::R_ARM_THM_TLS_CALL:
2072 case elfcpp::R_ARM_GOTRELAX:
2073 case elfcpp::R_ARM_GNU_VTENTRY:
2074 case elfcpp::R_ARM_GNU_VTINHERIT:
2075 case elfcpp::R_ARM_THM_TLS_DESCSEQ16:
2076 case elfcpp::R_ARM_THM_TLS_DESCSEQ32:
2077 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_0;
2078 // These should have been converted to something else above.
2079 case elfcpp::R_ARM_TARGET1:
2080 case elfcpp::R_ARM_TARGET2:
2081 gold_unreachable();
2082 // Relocations that write full 32 bits and
2083 // have alignment of 1.
2084 case elfcpp::R_ARM_ABS32:
2085 case elfcpp::R_ARM_REL32:
2086 case elfcpp::R_ARM_SBREL32:
2087 case elfcpp::R_ARM_GOTOFF32:
2088 case elfcpp::R_ARM_BASE_PREL:
2089 case elfcpp::R_ARM_GOT_BREL:
2090 case elfcpp::R_ARM_BASE_ABS:
2091 case elfcpp::R_ARM_ABS32_NOI:
2092 case elfcpp::R_ARM_REL32_NOI:
2093 case elfcpp::R_ARM_PLT32_ABS:
2094 case elfcpp::R_ARM_GOT_ABS:
2095 case elfcpp::R_ARM_GOT_PREL:
2096 case elfcpp::R_ARM_TLS_GD32:
2097 case elfcpp::R_ARM_TLS_LDM32:
2098 case elfcpp::R_ARM_TLS_LDO32:
2099 case elfcpp::R_ARM_TLS_IE32:
2100 case elfcpp::R_ARM_TLS_LE32:
2101 return Relocatable_relocs::RELOC_ADJUST_FOR_SECTION_4_UNALIGNED;
2102 default:
2103 // For all other static relocations, return RELOC_SPECIAL.
2104 return Relocatable_relocs::RELOC_SPECIAL;
2105 }
2106 }
2107 }
2108 };
2109
2110 template<bool big_endian>
2111 class Target_arm : public Sized_target<32, big_endian>
2112 {
2113 public:
2114 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2115 Reloc_section;
2116
2117 // When were are relocating a stub, we pass this as the relocation number.
2118 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2119
2120 Target_arm(const Target::Target_info* info = &arm_info)
2121 : Sized_target<32, big_endian>(info),
2122 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2123 copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
2124 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2125 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2126 should_force_pic_veneer_(false),
2127 arm_input_section_map_(), attributes_section_data_(NULL),
2128 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2129 { }
2130
2131 // Whether we force PCI branch veneers.
2132 bool
2133 should_force_pic_veneer() const
2134 { return this->should_force_pic_veneer_; }
2135
2136 // Set PIC veneer flag.
2137 void
2138 set_should_force_pic_veneer(bool value)
2139 { this->should_force_pic_veneer_ = value; }
2140
2141 // Whether we use THUMB-2 instructions.
2142 bool
2143 using_thumb2() const
2144 {
2145 Object_attribute* attr =
2146 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2147 int arch = attr->int_value();
2148 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2149 }
2150
2151 // Whether we use THUMB/THUMB-2 instructions only.
2152 bool
2153 using_thumb_only() const
2154 {
2155 Object_attribute* attr =
2156 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2157
2158 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2159 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2160 return true;
2161 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2162 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2163 return false;
2164 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2165 return attr->int_value() == 'M';
2166 }
2167
2168 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2169 bool
2170 may_use_arm_nop() const
2171 {
2172 Object_attribute* attr =
2173 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2174 int arch = attr->int_value();
2175 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2176 || arch == elfcpp::TAG_CPU_ARCH_V6K
2177 || arch == elfcpp::TAG_CPU_ARCH_V7
2178 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2179 }
2180
2181 // Whether we have THUMB-2 NOP.W instruction.
2182 bool
2183 may_use_thumb2_nop() const
2184 {
2185 Object_attribute* attr =
2186 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2187 int arch = attr->int_value();
2188 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2189 || arch == elfcpp::TAG_CPU_ARCH_V7
2190 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2191 }
2192
2193 // Whether we have v4T interworking instructions available.
2194 bool
2195 may_use_v4t_interworking() const
2196 {
2197 Object_attribute* attr =
2198 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2199 int arch = attr->int_value();
2200 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2201 && arch != elfcpp::TAG_CPU_ARCH_V4);
2202 }
2203
2204 // Whether we have v5T interworking instructions available.
2205 bool
2206 may_use_v5t_interworking() const
2207 {
2208 Object_attribute* attr =
2209 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2210 int arch = attr->int_value();
2211 if (parameters->options().fix_arm1176())
2212 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2213 || arch == elfcpp::TAG_CPU_ARCH_V7
2214 || arch == elfcpp::TAG_CPU_ARCH_V6_M
2215 || arch == elfcpp::TAG_CPU_ARCH_V6S_M
2216 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2217 else
2218 return (arch != elfcpp::TAG_CPU_ARCH_PRE_V4
2219 && arch != elfcpp::TAG_CPU_ARCH_V4
2220 && arch != elfcpp::TAG_CPU_ARCH_V4T);
2221 }
2222
2223 // Process the relocations to determine unreferenced sections for
2224 // garbage collection.
2225 void
2226 gc_process_relocs(Symbol_table* symtab,
2227 Layout* layout,
2228 Sized_relobj_file<32, big_endian>* object,
2229 unsigned int data_shndx,
2230 unsigned int sh_type,
2231 const unsigned char* prelocs,
2232 size_t reloc_count,
2233 Output_section* output_section,
2234 bool needs_special_offset_handling,
2235 size_t local_symbol_count,
2236 const unsigned char* plocal_symbols);
2237
2238 // Scan the relocations to look for symbol adjustments.
2239 void
2240 scan_relocs(Symbol_table* symtab,
2241 Layout* layout,
2242 Sized_relobj_file<32, big_endian>* object,
2243 unsigned int data_shndx,
2244 unsigned int sh_type,
2245 const unsigned char* prelocs,
2246 size_t reloc_count,
2247 Output_section* output_section,
2248 bool needs_special_offset_handling,
2249 size_t local_symbol_count,
2250 const unsigned char* plocal_symbols);
2251
2252 // Finalize the sections.
2253 void
2254 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2255
2256 // Return the value to use for a dynamic symbol which requires special
2257 // treatment.
2258 uint64_t
2259 do_dynsym_value(const Symbol*) const;
2260
2261 // Relocate a section.
2262 void
2263 relocate_section(const Relocate_info<32, big_endian>*,
2264 unsigned int sh_type,
2265 const unsigned char* prelocs,
2266 size_t reloc_count,
2267 Output_section* output_section,
2268 bool needs_special_offset_handling,
2269 unsigned char* view,
2270 Arm_address view_address,
2271 section_size_type view_size,
2272 const Reloc_symbol_changes*);
2273
2274 // Scan the relocs during a relocatable link.
2275 void
2276 scan_relocatable_relocs(Symbol_table* symtab,
2277 Layout* layout,
2278 Sized_relobj_file<32, big_endian>* object,
2279 unsigned int data_shndx,
2280 unsigned int sh_type,
2281 const unsigned char* prelocs,
2282 size_t reloc_count,
2283 Output_section* output_section,
2284 bool needs_special_offset_handling,
2285 size_t local_symbol_count,
2286 const unsigned char* plocal_symbols,
2287 Relocatable_relocs*);
2288
2289 // Emit relocations for a section.
2290 void
2291 relocate_relocs(const Relocate_info<32, big_endian>*,
2292 unsigned int sh_type,
2293 const unsigned char* prelocs,
2294 size_t reloc_count,
2295 Output_section* output_section,
2296 typename elfcpp::Elf_types<32>::Elf_Off
2297 offset_in_output_section,
2298 const Relocatable_relocs*,
2299 unsigned char* view,
2300 Arm_address view_address,
2301 section_size_type view_size,
2302 unsigned char* reloc_view,
2303 section_size_type reloc_view_size);
2304
2305 // Perform target-specific processing in a relocatable link. This is
2306 // only used if we use the relocation strategy RELOC_SPECIAL.
2307 void
2308 relocate_special_relocatable(const Relocate_info<32, big_endian>* relinfo,
2309 unsigned int sh_type,
2310 const unsigned char* preloc_in,
2311 size_t relnum,
2312 Output_section* output_section,
2313 typename elfcpp::Elf_types<32>::Elf_Off
2314 offset_in_output_section,
2315 unsigned char* view,
2316 typename elfcpp::Elf_types<32>::Elf_Addr
2317 view_address,
2318 section_size_type view_size,
2319 unsigned char* preloc_out);
2320
2321 // Return whether SYM is defined by the ABI.
2322 bool
2323 do_is_defined_by_abi(const Symbol* sym) const
2324 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2325
2326 // Return whether there is a GOT section.
2327 bool
2328 has_got_section() const
2329 { return this->got_ != NULL; }
2330
2331 // Return the size of the GOT section.
2332 section_size_type
2333 got_size() const
2334 {
2335 gold_assert(this->got_ != NULL);
2336 return this->got_->data_size();
2337 }
2338
2339 // Return the number of entries in the GOT.
2340 unsigned int
2341 got_entry_count() const
2342 {
2343 if (!this->has_got_section())
2344 return 0;
2345 return this->got_size() / 4;
2346 }
2347
2348 // Return the number of entries in the PLT.
2349 unsigned int
2350 plt_entry_count() const;
2351
2352 // Return the offset of the first non-reserved PLT entry.
2353 unsigned int
2354 first_plt_entry_offset() const;
2355
2356 // Return the size of each PLT entry.
2357 unsigned int
2358 plt_entry_size() const;
2359
2360 // Map platform-specific reloc types
2361 static unsigned int
2362 get_real_reloc_type(unsigned int r_type);
2363
2364 //
2365 // Methods to support stub-generations.
2366 //
2367
2368 // Return the stub factory
2369 const Stub_factory&
2370 stub_factory() const
2371 { return this->stub_factory_; }
2372
2373 // Make a new Arm_input_section object.
2374 Arm_input_section<big_endian>*
2375 new_arm_input_section(Relobj*, unsigned int);
2376
2377 // Find the Arm_input_section object corresponding to the SHNDX-th input
2378 // section of RELOBJ.
2379 Arm_input_section<big_endian>*
2380 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2381
2382 // Make a new Stub_table
2383 Stub_table<big_endian>*
2384 new_stub_table(Arm_input_section<big_endian>*);
2385
2386 // Scan a section for stub generation.
2387 void
2388 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2389 const unsigned char*, size_t, Output_section*,
2390 bool, const unsigned char*, Arm_address,
2391 section_size_type);
2392
2393 // Relocate a stub.
2394 void
2395 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2396 Output_section*, unsigned char*, Arm_address,
2397 section_size_type);
2398
2399 // Get the default ARM target.
2400 static Target_arm<big_endian>*
2401 default_target()
2402 {
2403 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2404 && parameters->target().is_big_endian() == big_endian);
2405 return static_cast<Target_arm<big_endian>*>(
2406 parameters->sized_target<32, big_endian>());
2407 }
2408
2409 // Whether NAME belongs to a mapping symbol.
2410 static bool
2411 is_mapping_symbol_name(const char* name)
2412 {
2413 return (name
2414 && name[0] == '$'
2415 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2416 && (name[2] == '\0' || name[2] == '.'));
2417 }
2418
2419 // Whether we work around the Cortex-A8 erratum.
2420 bool
2421 fix_cortex_a8() const
2422 { return this->fix_cortex_a8_; }
2423
2424 // Whether we merge exidx entries in debuginfo.
2425 bool
2426 merge_exidx_entries() const
2427 { return parameters->options().merge_exidx_entries(); }
2428
2429 // Whether we fix R_ARM_V4BX relocation.
2430 // 0 - do not fix
2431 // 1 - replace with MOV instruction (armv4 target)
2432 // 2 - make interworking veneer (>= armv4t targets only)
2433 General_options::Fix_v4bx
2434 fix_v4bx() const
2435 { return parameters->options().fix_v4bx(); }
2436
2437 // Scan a span of THUMB code section for Cortex-A8 erratum.
2438 void
2439 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2440 section_size_type, section_size_type,
2441 const unsigned char*, Arm_address);
2442
2443 // Apply Cortex-A8 workaround to a branch.
2444 void
2445 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2446 unsigned char*, Arm_address);
2447
2448 protected:
2449 // Make the PLT-generator object.
2450 Output_data_plt_arm<big_endian>*
2451 make_data_plt(Layout* layout, Output_data_space* got_plt)
2452 { return this->do_make_data_plt(layout, got_plt); }
2453
2454 // Make an ELF object.
2455 Object*
2456 do_make_elf_object(const std::string&, Input_file*, off_t,
2457 const elfcpp::Ehdr<32, big_endian>& ehdr);
2458
2459 Object*
2460 do_make_elf_object(const std::string&, Input_file*, off_t,
2461 const elfcpp::Ehdr<32, !big_endian>&)
2462 { gold_unreachable(); }
2463
2464 Object*
2465 do_make_elf_object(const std::string&, Input_file*, off_t,
2466 const elfcpp::Ehdr<64, false>&)
2467 { gold_unreachable(); }
2468
2469 Object*
2470 do_make_elf_object(const std::string&, Input_file*, off_t,
2471 const elfcpp::Ehdr<64, true>&)
2472 { gold_unreachable(); }
2473
2474 // Make an output section.
2475 Output_section*
2476 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2477 elfcpp::Elf_Xword flags)
2478 { return new Arm_output_section<big_endian>(name, type, flags); }
2479
2480 void
2481 do_adjust_elf_header(unsigned char* view, int len);
2482
2483 // We only need to generate stubs, and hence perform relaxation if we are
2484 // not doing relocatable linking.
2485 bool
2486 do_may_relax() const
2487 { return !parameters->options().relocatable(); }
2488
2489 bool
2490 do_relax(int, const Input_objects*, Symbol_table*, Layout*, const Task*);
2491
2492 // Determine whether an object attribute tag takes an integer, a
2493 // string or both.
2494 int
2495 do_attribute_arg_type(int tag) const;
2496
2497 // Reorder tags during output.
2498 int
2499 do_attributes_order(int num) const;
2500
2501 // This is called when the target is selected as the default.
2502 void
2503 do_select_as_default_target()
2504 {
2505 // No locking is required since there should only be one default target.
2506 // We cannot have both the big-endian and little-endian ARM targets
2507 // as the default.
2508 gold_assert(arm_reloc_property_table == NULL);
2509 arm_reloc_property_table = new Arm_reloc_property_table();
2510 }
2511
2512 // Virtual function which is set to return true by a target if
2513 // it can use relocation types to determine if a function's
2514 // pointer is taken.
2515 virtual bool
2516 do_can_check_for_function_pointers() const
2517 { return true; }
2518
2519 // Whether a section called SECTION_NAME may have function pointers to
2520 // sections not eligible for safe ICF folding.
2521 virtual bool
2522 do_section_may_have_icf_unsafe_pointers(const char* section_name) const
2523 {
2524 return (!is_prefix_of(".ARM.exidx", section_name)
2525 && !is_prefix_of(".ARM.extab", section_name)
2526 && Target::do_section_may_have_icf_unsafe_pointers(section_name));
2527 }
2528
2529 virtual void
2530 do_define_standard_symbols(Symbol_table*, Layout*);
2531
2532 virtual Output_data_plt_arm<big_endian>*
2533 do_make_data_plt(Layout* layout, Output_data_space* got_plt)
2534 {
2535 return new Output_data_plt_arm_standard<big_endian>(layout, got_plt);
2536 }
2537
2538 private:
2539 // The class which scans relocations.
2540 class Scan
2541 {
2542 public:
2543 Scan()
2544 : issued_non_pic_error_(false)
2545 { }
2546
2547 static inline int
2548 get_reference_flags(unsigned int r_type);
2549
2550 inline void
2551 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2552 Sized_relobj_file<32, big_endian>* object,
2553 unsigned int data_shndx,
2554 Output_section* output_section,
2555 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2556 const elfcpp::Sym<32, big_endian>& lsym,
2557 bool is_discarded);
2558
2559 inline void
2560 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2561 Sized_relobj_file<32, big_endian>* object,
2562 unsigned int data_shndx,
2563 Output_section* output_section,
2564 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2565 Symbol* gsym);
2566
2567 inline bool
2568 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2569 Sized_relobj_file<32, big_endian>* ,
2570 unsigned int ,
2571 Output_section* ,
2572 const elfcpp::Rel<32, big_endian>& ,
2573 unsigned int ,
2574 const elfcpp::Sym<32, big_endian>&);
2575
2576 inline bool
2577 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2578 Sized_relobj_file<32, big_endian>* ,
2579 unsigned int ,
2580 Output_section* ,
2581 const elfcpp::Rel<32, big_endian>& ,
2582 unsigned int , Symbol*);
2583
2584 private:
2585 static void
2586 unsupported_reloc_local(Sized_relobj_file<32, big_endian>*,
2587 unsigned int r_type);
2588
2589 static void
2590 unsupported_reloc_global(Sized_relobj_file<32, big_endian>*,
2591 unsigned int r_type, Symbol*);
2592
2593 void
2594 check_non_pic(Relobj*, unsigned int r_type);
2595
2596 // Almost identical to Symbol::needs_plt_entry except that it also
2597 // handles STT_ARM_TFUNC.
2598 static bool
2599 symbol_needs_plt_entry(const Symbol* sym)
2600 {
2601 // An undefined symbol from an executable does not need a PLT entry.
2602 if (sym->is_undefined() && !parameters->options().shared())
2603 return false;
2604
2605 return (!parameters->doing_static_link()
2606 && (sym->type() == elfcpp::STT_FUNC
2607 || sym->type() == elfcpp::STT_ARM_TFUNC)
2608 && (sym->is_from_dynobj()
2609 || sym->is_undefined()
2610 || sym->is_preemptible()));
2611 }
2612
2613 inline bool
2614 possible_function_pointer_reloc(unsigned int r_type);
2615
2616 // Whether we have issued an error about a non-PIC compilation.
2617 bool issued_non_pic_error_;
2618 };
2619
2620 // The class which implements relocation.
2621 class Relocate
2622 {
2623 public:
2624 Relocate()
2625 { }
2626
2627 ~Relocate()
2628 { }
2629
2630 // Return whether the static relocation needs to be applied.
2631 inline bool
2632 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2633 unsigned int r_type,
2634 bool is_32bit,
2635 Output_section* output_section);
2636
2637 // Do a relocation. Return false if the caller should not issue
2638 // any warnings about this relocation.
2639 inline bool
2640 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2641 Output_section*, size_t relnum,
2642 const elfcpp::Rel<32, big_endian>&,
2643 unsigned int r_type, const Sized_symbol<32>*,
2644 const Symbol_value<32>*,
2645 unsigned char*, Arm_address,
2646 section_size_type);
2647
2648 // Return whether we want to pass flag NON_PIC_REF for this
2649 // reloc. This means the relocation type accesses a symbol not via
2650 // GOT or PLT.
2651 static inline bool
2652 reloc_is_non_pic(unsigned int r_type)
2653 {
2654 switch (r_type)
2655 {
2656 // These relocation types reference GOT or PLT entries explicitly.
2657 case elfcpp::R_ARM_GOT_BREL:
2658 case elfcpp::R_ARM_GOT_ABS:
2659 case elfcpp::R_ARM_GOT_PREL:
2660 case elfcpp::R_ARM_GOT_BREL12:
2661 case elfcpp::R_ARM_PLT32_ABS:
2662 case elfcpp::R_ARM_TLS_GD32:
2663 case elfcpp::R_ARM_TLS_LDM32:
2664 case elfcpp::R_ARM_TLS_IE32:
2665 case elfcpp::R_ARM_TLS_IE12GP:
2666
2667 // These relocate types may use PLT entries.
2668 case elfcpp::R_ARM_CALL:
2669 case elfcpp::R_ARM_THM_CALL:
2670 case elfcpp::R_ARM_JUMP24:
2671 case elfcpp::R_ARM_THM_JUMP24:
2672 case elfcpp::R_ARM_THM_JUMP19:
2673 case elfcpp::R_ARM_PLT32:
2674 case elfcpp::R_ARM_THM_XPC22:
2675 case elfcpp::R_ARM_PREL31:
2676 case elfcpp::R_ARM_SBREL31:
2677 return false;
2678
2679 default:
2680 return true;
2681 }
2682 }
2683
2684 private:
2685 // Do a TLS relocation.
2686 inline typename Arm_relocate_functions<big_endian>::Status
2687 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2688 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2689 const Sized_symbol<32>*, const Symbol_value<32>*,
2690 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2691 section_size_type);
2692
2693 };
2694
2695 // A class which returns the size required for a relocation type,
2696 // used while scanning relocs during a relocatable link.
2697 class Relocatable_size_for_reloc
2698 {
2699 public:
2700 unsigned int
2701 get_size_for_reloc(unsigned int, Relobj*);
2702 };
2703
2704 // Adjust TLS relocation type based on the options and whether this
2705 // is a local symbol.
2706 static tls::Tls_optimization
2707 optimize_tls_reloc(bool is_final, int r_type);
2708
2709 // Get the GOT section, creating it if necessary.
2710 Arm_output_data_got<big_endian>*
2711 got_section(Symbol_table*, Layout*);
2712
2713 // Get the GOT PLT section.
2714 Output_data_space*
2715 got_plt_section() const
2716 {
2717 gold_assert(this->got_plt_ != NULL);
2718 return this->got_plt_;
2719 }
2720
2721 // Create a PLT entry for a global symbol.
2722 void
2723 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2724
2725 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2726 void
2727 define_tls_base_symbol(Symbol_table*, Layout*);
2728
2729 // Create a GOT entry for the TLS module index.
2730 unsigned int
2731 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2732 Sized_relobj_file<32, big_endian>* object);
2733
2734 // Get the PLT section.
2735 const Output_data_plt_arm<big_endian>*
2736 plt_section() const
2737 {
2738 gold_assert(this->plt_ != NULL);
2739 return this->plt_;
2740 }
2741
2742 // Get the dynamic reloc section, creating it if necessary.
2743 Reloc_section*
2744 rel_dyn_section(Layout*);
2745
2746 // Get the section to use for TLS_DESC relocations.
2747 Reloc_section*
2748 rel_tls_desc_section(Layout*) const;
2749
2750 // Return true if the symbol may need a COPY relocation.
2751 // References from an executable object to non-function symbols
2752 // defined in a dynamic object may need a COPY relocation.
2753 bool
2754 may_need_copy_reloc(Symbol* gsym)
2755 {
2756 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2757 && gsym->may_need_copy_reloc());
2758 }
2759
2760 // Add a potential copy relocation.
2761 void
2762 copy_reloc(Symbol_table* symtab, Layout* layout,
2763 Sized_relobj_file<32, big_endian>* object,
2764 unsigned int shndx, Output_section* output_section,
2765 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2766 {
2767 this->copy_relocs_.copy_reloc(symtab, layout,
2768 symtab->get_sized_symbol<32>(sym),
2769 object, shndx, output_section, reloc,
2770 this->rel_dyn_section(layout));
2771 }
2772
2773 // Whether two EABI versions are compatible.
2774 static bool
2775 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2776
2777 // Merge processor-specific flags from input object and those in the ELF
2778 // header of the output.
2779 void
2780 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2781
2782 // Get the secondary compatible architecture.
2783 static int
2784 get_secondary_compatible_arch(const Attributes_section_data*);
2785
2786 // Set the secondary compatible architecture.
2787 static void
2788 set_secondary_compatible_arch(Attributes_section_data*, int);
2789
2790 static int
2791 tag_cpu_arch_combine(const char*, int, int*, int, int);
2792
2793 // Helper to print AEABI enum tag value.
2794 static std::string
2795 aeabi_enum_name(unsigned int);
2796
2797 // Return string value for TAG_CPU_name.
2798 static std::string
2799 tag_cpu_name_value(unsigned int);
2800
2801 // Query attributes object to see if integer divide instructions may be
2802 // present in an object.
2803 static bool
2804 attributes_accept_div(int arch, int profile,
2805 const Object_attribute* div_attr);
2806
2807 // Query attributes object to see if integer divide instructions are
2808 // forbidden to be in the object. This is not the inverse of
2809 // attributes_accept_div.
2810 static bool
2811 attributes_forbid_div(const Object_attribute* div_attr);
2812
2813 // Merge object attributes from input object and those in the output.
2814 void
2815 merge_object_attributes(const char*, const Attributes_section_data*);
2816
2817 // Helper to get an AEABI object attribute
2818 Object_attribute*
2819 get_aeabi_object_attribute(int tag) const
2820 {
2821 Attributes_section_data* pasd = this->attributes_section_data_;
2822 gold_assert(pasd != NULL);
2823 Object_attribute* attr =
2824 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2825 gold_assert(attr != NULL);
2826 return attr;
2827 }
2828
2829 //
2830 // Methods to support stub-generations.
2831 //
2832
2833 // Group input sections for stub generation.
2834 void
2835 group_sections(Layout*, section_size_type, bool, const Task*);
2836
2837 // Scan a relocation for stub generation.
2838 void
2839 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2840 const Sized_symbol<32>*, unsigned int,
2841 const Symbol_value<32>*,
2842 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2843
2844 // Scan a relocation section for stub.
2845 template<int sh_type>
2846 void
2847 scan_reloc_section_for_stubs(
2848 const Relocate_info<32, big_endian>* relinfo,
2849 const unsigned char* prelocs,
2850 size_t reloc_count,
2851 Output_section* output_section,
2852 bool needs_special_offset_handling,
2853 const unsigned char* view,
2854 elfcpp::Elf_types<32>::Elf_Addr view_address,
2855 section_size_type);
2856
2857 // Fix .ARM.exidx section coverage.
2858 void
2859 fix_exidx_coverage(Layout*, const Input_objects*,
2860 Arm_output_section<big_endian>*, Symbol_table*,
2861 const Task*);
2862
2863 // Functors for STL set.
2864 struct output_section_address_less_than
2865 {
2866 bool
2867 operator()(const Output_section* s1, const Output_section* s2) const
2868 { return s1->address() < s2->address(); }
2869 };
2870
2871 // Information about this specific target which we pass to the
2872 // general Target structure.
2873 static const Target::Target_info arm_info;
2874
2875 // The types of GOT entries needed for this platform.
2876 // These values are exposed to the ABI in an incremental link.
2877 // Do not renumber existing values without changing the version
2878 // number of the .gnu_incremental_inputs section.
2879 enum Got_type
2880 {
2881 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2882 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2883 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2884 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2885 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2886 };
2887
2888 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2889
2890 // Map input section to Arm_input_section.
2891 typedef Unordered_map<Section_id,
2892 Arm_input_section<big_endian>*,
2893 Section_id_hash>
2894 Arm_input_section_map;
2895
2896 // Map output addresses to relocs for Cortex-A8 erratum.
2897 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2898 Cortex_a8_relocs_info;
2899
2900 // The GOT section.
2901 Arm_output_data_got<big_endian>* got_;
2902 // The PLT section.
2903 Output_data_plt_arm<big_endian>* plt_;
2904 // The GOT PLT section.
2905 Output_data_space* got_plt_;
2906 // The dynamic reloc section.
2907 Reloc_section* rel_dyn_;
2908 // Relocs saved to avoid a COPY reloc.
2909 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2910 // Space for variables copied with a COPY reloc.
2911 Output_data_space* dynbss_;
2912 // Offset of the GOT entry for the TLS module index.
2913 unsigned int got_mod_index_offset_;
2914 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2915 bool tls_base_symbol_defined_;
2916 // Vector of Stub_tables created.
2917 Stub_table_list stub_tables_;
2918 // Stub factory.
2919 const Stub_factory &stub_factory_;
2920 // Whether we force PIC branch veneers.
2921 bool should_force_pic_veneer_;
2922 // Map for locating Arm_input_sections.
2923 Arm_input_section_map arm_input_section_map_;
2924 // Attributes section data in output.
2925 Attributes_section_data* attributes_section_data_;
2926 // Whether we want to fix code for Cortex-A8 erratum.
2927 bool fix_cortex_a8_;
2928 // Map addresses to relocs for Cortex-A8 erratum.
2929 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2930 };
2931
2932 template<bool big_endian>
2933 const Target::Target_info Target_arm<big_endian>::arm_info =
2934 {
2935 32, // size
2936 big_endian, // is_big_endian
2937 elfcpp::EM_ARM, // machine_code
2938 false, // has_make_symbol
2939 false, // has_resolve
2940 false, // has_code_fill
2941 true, // is_default_stack_executable
2942 false, // can_icf_inline_merge_sections
2943 '\0', // wrap_char
2944 "/usr/lib/libc.so.1", // dynamic_linker
2945 0x8000, // default_text_segment_address
2946 0x1000, // abi_pagesize (overridable by -z max-page-size)
2947 0x1000, // common_pagesize (overridable by -z common-page-size)
2948 false, // isolate_execinstr
2949 0, // rosegment_gap
2950 elfcpp::SHN_UNDEF, // small_common_shndx
2951 elfcpp::SHN_UNDEF, // large_common_shndx
2952 0, // small_common_section_flags
2953 0, // large_common_section_flags
2954 ".ARM.attributes", // attributes_section
2955 "aeabi" // attributes_vendor
2956 };
2957
2958 // Arm relocate functions class
2959 //
2960
2961 template<bool big_endian>
2962 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2963 {
2964 public:
2965 typedef enum
2966 {
2967 STATUS_OKAY, // No error during relocation.
2968 STATUS_OVERFLOW, // Relocation overflow.
2969 STATUS_BAD_RELOC // Relocation cannot be applied.
2970 } Status;
2971
2972 private:
2973 typedef Relocate_functions<32, big_endian> Base;
2974 typedef Arm_relocate_functions<big_endian> This;
2975
2976 // Encoding of imm16 argument for movt and movw ARM instructions
2977 // from ARM ARM:
2978 //
2979 // imm16 := imm4 | imm12
2980 //
2981 // 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
2982 // +-------+---------------+-------+-------+-----------------------+
2983 // | | |imm4 | |imm12 |
2984 // +-------+---------------+-------+-------+-----------------------+
2985
2986 // Extract the relocation addend from VAL based on the ARM
2987 // instruction encoding described above.
2988 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2989 extract_arm_movw_movt_addend(
2990 typename elfcpp::Swap<32, big_endian>::Valtype val)
2991 {
2992 // According to the Elf ABI for ARM Architecture the immediate
2993 // field is sign-extended to form the addend.
2994 return Bits<16>::sign_extend32(((val >> 4) & 0xf000) | (val & 0xfff));
2995 }
2996
2997 // Insert X into VAL based on the ARM instruction encoding described
2998 // above.
2999 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3000 insert_val_arm_movw_movt(
3001 typename elfcpp::Swap<32, big_endian>::Valtype val,
3002 typename elfcpp::Swap<32, big_endian>::Valtype x)
3003 {
3004 val &= 0xfff0f000;
3005 val |= x & 0x0fff;
3006 val |= (x & 0xf000) << 4;
3007 return val;
3008 }
3009
3010 // Encoding of imm16 argument for movt and movw Thumb2 instructions
3011 // from ARM ARM:
3012 //
3013 // imm16 := imm4 | i | imm3 | imm8
3014 //
3015 // 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
3016 // +---------+-+-----------+-------++-+-----+-------+---------------+
3017 // | |i| |imm4 || |imm3 | |imm8 |
3018 // +---------+-+-----------+-------++-+-----+-------+---------------+
3019
3020 // Extract the relocation addend from VAL based on the Thumb2
3021 // instruction encoding described above.
3022 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3023 extract_thumb_movw_movt_addend(
3024 typename elfcpp::Swap<32, big_endian>::Valtype val)
3025 {
3026 // According to the Elf ABI for ARM Architecture the immediate
3027 // field is sign-extended to form the addend.
3028 return Bits<16>::sign_extend32(((val >> 4) & 0xf000)
3029 | ((val >> 15) & 0x0800)
3030 | ((val >> 4) & 0x0700)
3031 | (val & 0x00ff));
3032 }
3033
3034 // Insert X into VAL based on the Thumb2 instruction encoding
3035 // described above.
3036 static inline typename elfcpp::Swap<32, big_endian>::Valtype
3037 insert_val_thumb_movw_movt(
3038 typename elfcpp::Swap<32, big_endian>::Valtype val,
3039 typename elfcpp::Swap<32, big_endian>::Valtype x)
3040 {
3041 val &= 0xfbf08f00;
3042 val |= (x & 0xf000) << 4;
3043 val |= (x & 0x0800) << 15;
3044 val |= (x & 0x0700) << 4;
3045 val |= (x & 0x00ff);
3046 return val;
3047 }
3048
3049 // Calculate the smallest constant Kn for the specified residual.
3050 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3051 static uint32_t
3052 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
3053 {
3054 int32_t msb;
3055
3056 if (residual == 0)
3057 return 0;
3058 // Determine the most significant bit in the residual and
3059 // align the resulting value to a 2-bit boundary.
3060 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
3061 ;
3062 // The desired shift is now (msb - 6), or zero, whichever
3063 // is the greater.
3064 return (((msb - 6) < 0) ? 0 : (msb - 6));
3065 }
3066
3067 // Calculate the final residual for the specified group index.
3068 // If the passed group index is less than zero, the method will return
3069 // the value of the specified residual without any change.
3070 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3071 static typename elfcpp::Swap<32, big_endian>::Valtype
3072 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3073 const int group)
3074 {
3075 for (int n = 0; n <= group; n++)
3076 {
3077 // Calculate which part of the value to mask.
3078 uint32_t shift = calc_grp_kn(residual);
3079 // Calculate the residual for the next time around.
3080 residual &= ~(residual & (0xff << shift));
3081 }
3082
3083 return residual;
3084 }
3085
3086 // Calculate the value of Gn for the specified group index.
3087 // We return it in the form of an encoded constant-and-rotation.
3088 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
3089 static typename elfcpp::Swap<32, big_endian>::Valtype
3090 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
3091 const int group)
3092 {
3093 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
3094 uint32_t shift = 0;
3095
3096 for (int n = 0; n <= group; n++)
3097 {
3098 // Calculate which part of the value to mask.
3099 shift = calc_grp_kn(residual);
3100 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
3101 gn = residual & (0xff << shift);
3102 // Calculate the residual for the next time around.
3103 residual &= ~gn;
3104 }
3105 // Return Gn in the form of an encoded constant-and-rotation.
3106 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
3107 }
3108
3109 public:
3110 // Handle ARM long branches.
3111 static typename This::Status
3112 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3113 unsigned char*, const Sized_symbol<32>*,
3114 const Arm_relobj<big_endian>*, unsigned int,
3115 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3116
3117 // Handle THUMB long branches.
3118 static typename This::Status
3119 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
3120 unsigned char*, const Sized_symbol<32>*,
3121 const Arm_relobj<big_endian>*, unsigned int,
3122 const Symbol_value<32>*, Arm_address, Arm_address, bool);
3123
3124
3125 // Return the branch offset of a 32-bit THUMB branch.
3126 static inline int32_t
3127 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3128 {
3129 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
3130 // involving the J1 and J2 bits.
3131 uint32_t s = (upper_insn & (1U << 10)) >> 10;
3132 uint32_t upper = upper_insn & 0x3ffU;
3133 uint32_t lower = lower_insn & 0x7ffU;
3134 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
3135 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
3136 uint32_t i1 = j1 ^ s ? 0 : 1;
3137 uint32_t i2 = j2 ^ s ? 0 : 1;
3138
3139 return Bits<25>::sign_extend32((s << 24) | (i1 << 23) | (i2 << 22)
3140 | (upper << 12) | (lower << 1));
3141 }
3142
3143 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
3144 // UPPER_INSN is the original upper instruction of the branch. Caller is
3145 // responsible for overflow checking and BLX offset adjustment.
3146 static inline uint16_t
3147 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
3148 {
3149 uint32_t s = offset < 0 ? 1 : 0;
3150 uint32_t bits = static_cast<uint32_t>(offset);
3151 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
3152 }
3153
3154 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
3155 // LOWER_INSN is the original lower instruction of the branch. Caller is
3156 // responsible for overflow checking and BLX offset adjustment.
3157 static inline uint16_t
3158 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
3159 {
3160 uint32_t s = offset < 0 ? 1 : 0;
3161 uint32_t bits = static_cast<uint32_t>(offset);
3162 return ((lower_insn & ~0x2fffU)
3163 | ((((bits >> 23) & 1) ^ !s) << 13)
3164 | ((((bits >> 22) & 1) ^ !s) << 11)
3165 | ((bits >> 1) & 0x7ffU));
3166 }
3167
3168 // Return the branch offset of a 32-bit THUMB conditional branch.
3169 static inline int32_t
3170 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
3171 {
3172 uint32_t s = (upper_insn & 0x0400U) >> 10;
3173 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
3174 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
3175 uint32_t lower = (lower_insn & 0x07ffU);
3176 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
3177
3178 return Bits<21>::sign_extend32((upper << 12) | (lower << 1));
3179 }
3180
3181 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
3182 // instruction. UPPER_INSN is the original upper instruction of the branch.
3183 // Caller is responsible for overflow checking.
3184 static inline uint16_t
3185 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
3186 {
3187 uint32_t s = offset < 0 ? 1 : 0;
3188 uint32_t bits = static_cast<uint32_t>(offset);
3189 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
3190 }
3191
3192 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
3193 // instruction. LOWER_INSN is the original lower instruction of the branch.
3194 // The caller is responsible for overflow checking.
3195 static inline uint16_t
3196 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
3197 {
3198 uint32_t bits = static_cast<uint32_t>(offset);
3199 uint32_t j2 = (bits & 0x00080000U) >> 19;
3200 uint32_t j1 = (bits & 0x00040000U) >> 18;
3201 uint32_t lo = (bits & 0x00000ffeU) >> 1;
3202
3203 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
3204 }
3205
3206 // R_ARM_ABS8: S + A
3207 static inline typename This::Status
3208 abs8(unsigned char* view,
3209 const Sized_relobj_file<32, big_endian>* object,
3210 const Symbol_value<32>* psymval)
3211 {
3212 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
3213 Valtype* wv = reinterpret_cast<Valtype*>(view);
3214 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
3215 int32_t addend = Bits<8>::sign_extend32(val);
3216 Arm_address x = psymval->value(object, addend);
3217 val = Bits<32>::bit_select32(val, x, 0xffU);
3218 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3219
3220 // R_ARM_ABS8 permits signed or unsigned results.
3221 return (Bits<8>::has_signed_unsigned_overflow32(x)
3222 ? This::STATUS_OVERFLOW
3223 : This::STATUS_OKAY);
3224 }
3225
3226 // R_ARM_THM_ABS5: S + A
3227 static inline typename This::Status
3228 thm_abs5(unsigned char* view,
3229 const Sized_relobj_file<32, big_endian>* object,
3230 const Symbol_value<32>* psymval)
3231 {
3232 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3233 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3234 Valtype* wv = reinterpret_cast<Valtype*>(view);
3235 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3236 Reltype addend = (val & 0x7e0U) >> 6;
3237 Reltype x = psymval->value(object, addend);
3238 val = Bits<32>::bit_select32(val, x << 6, 0x7e0U);
3239 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3240 return (Bits<5>::has_overflow32(x)
3241 ? This::STATUS_OVERFLOW
3242 : This::STATUS_OKAY);
3243 }
3244
3245 // R_ARM_ABS12: S + A
3246 static inline typename This::Status
3247 abs12(unsigned char* view,
3248 const Sized_relobj_file<32, big_endian>* object,
3249 const Symbol_value<32>* psymval)
3250 {
3251 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3252 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3253 Valtype* wv = reinterpret_cast<Valtype*>(view);
3254 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3255 Reltype addend = val & 0x0fffU;
3256 Reltype x = psymval->value(object, addend);
3257 val = Bits<32>::bit_select32(val, x, 0x0fffU);
3258 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3259 return (Bits<12>::has_overflow32(x)
3260 ? This::STATUS_OVERFLOW
3261 : This::STATUS_OKAY);
3262 }
3263
3264 // R_ARM_ABS16: S + A
3265 static inline typename This::Status
3266 abs16(unsigned char* view,
3267 const Sized_relobj_file<32, big_endian>* object,
3268 const Symbol_value<32>* psymval)
3269 {
3270 typedef typename elfcpp::Swap_unaligned<16, big_endian>::Valtype Valtype;
3271 Valtype val = elfcpp::Swap_unaligned<16, big_endian>::readval(view);
3272 int32_t addend = Bits<16>::sign_extend32(val);
3273 Arm_address x = psymval->value(object, addend);
3274 val = Bits<32>::bit_select32(val, x, 0xffffU);
3275 elfcpp::Swap_unaligned<16, big_endian>::writeval(view, val);
3276
3277 // R_ARM_ABS16 permits signed or unsigned results.
3278 return (Bits<16>::has_signed_unsigned_overflow32(x)
3279 ? This::STATUS_OVERFLOW
3280 : This::STATUS_OKAY);
3281 }
3282
3283 // R_ARM_ABS32: (S + A) | T
3284 static inline typename This::Status
3285 abs32(unsigned char* view,
3286 const Sized_relobj_file<32, big_endian>* object,
3287 const Symbol_value<32>* psymval,
3288 Arm_address thumb_bit)
3289 {
3290 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3291 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3292 Valtype x = psymval->value(object, addend) | thumb_bit;
3293 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3294 return This::STATUS_OKAY;
3295 }
3296
3297 // R_ARM_REL32: (S + A) | T - P
3298 static inline typename This::Status
3299 rel32(unsigned char* view,
3300 const Sized_relobj_file<32, big_endian>* object,
3301 const Symbol_value<32>* psymval,
3302 Arm_address address,
3303 Arm_address thumb_bit)
3304 {
3305 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3306 Valtype addend = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3307 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3308 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, x);
3309 return This::STATUS_OKAY;
3310 }
3311
3312 // R_ARM_THM_JUMP24: (S + A) | T - P
3313 static typename This::Status
3314 thm_jump19(unsigned char* view, const Arm_relobj<big_endian>* object,
3315 const Symbol_value<32>* psymval, Arm_address address,
3316 Arm_address thumb_bit);
3317
3318 // R_ARM_THM_JUMP6: S + A – P
3319 static inline typename This::Status
3320 thm_jump6(unsigned char* view,
3321 const Sized_relobj_file<32, big_endian>* object,
3322 const Symbol_value<32>* psymval,
3323 Arm_address address)
3324 {
3325 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3326 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3327 Valtype* wv = reinterpret_cast<Valtype*>(view);
3328 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3329 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3330 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3331 Reltype x = (psymval->value(object, addend) - address);
3332 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3333 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3334 // CZB does only forward jumps.
3335 return ((x > 0x007e)
3336 ? This::STATUS_OVERFLOW
3337 : This::STATUS_OKAY);
3338 }
3339
3340 // R_ARM_THM_JUMP8: S + A – P
3341 static inline typename This::Status
3342 thm_jump8(unsigned char* view,
3343 const Sized_relobj_file<32, big_endian>* object,
3344 const Symbol_value<32>* psymval,
3345 Arm_address address)
3346 {
3347 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3348 Valtype* wv = reinterpret_cast<Valtype*>(view);
3349 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3350 int32_t addend = Bits<8>::sign_extend32((val & 0x00ff) << 1);
3351 int32_t x = (psymval->value(object, addend) - address);
3352 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xff00)
3353 | ((x & 0x01fe) >> 1)));
3354 // We do a 9-bit overflow check because x is right-shifted by 1 bit.
3355 return (Bits<9>::has_overflow32(x)
3356 ? This::STATUS_OVERFLOW
3357 : This::STATUS_OKAY);
3358 }
3359
3360 // R_ARM_THM_JUMP11: S + A – P
3361 static inline typename This::Status
3362 thm_jump11(unsigned char* view,
3363 const Sized_relobj_file<32, big_endian>* object,
3364 const Symbol_value<32>* psymval,
3365 Arm_address address)
3366 {
3367 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3368 Valtype* wv = reinterpret_cast<Valtype*>(view);
3369 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3370 int32_t addend = Bits<11>::sign_extend32((val & 0x07ff) << 1);
3371 int32_t x = (psymval->value(object, addend) - address);
3372 elfcpp::Swap<16, big_endian>::writeval(wv, ((val & 0xf800)
3373 | ((x & 0x0ffe) >> 1)));
3374 // We do a 12-bit overflow check because x is right-shifted by 1 bit.
3375 return (Bits<12>::has_overflow32(x)
3376 ? This::STATUS_OVERFLOW
3377 : This::STATUS_OKAY);
3378 }
3379
3380 // R_ARM_BASE_PREL: B(S) + A - P
3381 static inline typename This::Status
3382 base_prel(unsigned char* view,
3383 Arm_address origin,
3384 Arm_address address)
3385 {
3386 Base::rel32(view, origin - address);
3387 return STATUS_OKAY;
3388 }
3389
3390 // R_ARM_BASE_ABS: B(S) + A
3391 static inline typename This::Status
3392 base_abs(unsigned char* view,
3393 Arm_address origin)
3394 {
3395 Base::rel32(view, origin);
3396 return STATUS_OKAY;
3397 }
3398
3399 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3400 static inline typename This::Status
3401 got_brel(unsigned char* view,
3402 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3403 {
3404 Base::rel32(view, got_offset);
3405 return This::STATUS_OKAY;
3406 }
3407
3408 // R_ARM_GOT_PREL: GOT(S) + A - P
3409 static inline typename This::Status
3410 got_prel(unsigned char* view,
3411 Arm_address got_entry,
3412 Arm_address address)
3413 {
3414 Base::rel32(view, got_entry - address);
3415 return This::STATUS_OKAY;
3416 }
3417
3418 // R_ARM_PREL: (S + A) | T - P
3419 static inline typename This::Status
3420 prel31(unsigned char* view,
3421 const Sized_relobj_file<32, big_endian>* object,
3422 const Symbol_value<32>* psymval,
3423 Arm_address address,
3424 Arm_address thumb_bit)
3425 {
3426 typedef typename elfcpp::Swap_unaligned<32, big_endian>::Valtype Valtype;
3427 Valtype val = elfcpp::Swap_unaligned<32, big_endian>::readval(view);
3428 Valtype addend = Bits<31>::sign_extend32(val);
3429 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3430 val = Bits<32>::bit_select32(val, x, 0x7fffffffU);
3431 elfcpp::Swap_unaligned<32, big_endian>::writeval(view, val);
3432 return (Bits<31>::has_overflow32(x)
3433 ? This::STATUS_OVERFLOW
3434 : This::STATUS_OKAY);
3435 }
3436
3437 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3438 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3439 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3440 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3441 static inline typename This::Status
3442 movw(unsigned char* view,
3443 const Sized_relobj_file<32, big_endian>* object,
3444 const Symbol_value<32>* psymval,
3445 Arm_address relative_address_base,
3446 Arm_address thumb_bit,
3447 bool check_overflow)
3448 {
3449 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3450 Valtype* wv = reinterpret_cast<Valtype*>(view);
3451 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3452 Valtype addend = This::extract_arm_movw_movt_addend(val);
3453 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3454 - relative_address_base);
3455 val = This::insert_val_arm_movw_movt(val, x);
3456 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3457 return ((check_overflow && Bits<16>::has_overflow32(x))
3458 ? This::STATUS_OVERFLOW
3459 : This::STATUS_OKAY);
3460 }
3461
3462 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3463 // R_ARM_MOVT_PREL: S + A - P
3464 // R_ARM_MOVT_BREL: S + A - B(S)
3465 static inline typename This::Status
3466 movt(unsigned char* view,
3467 const Sized_relobj_file<32, big_endian>* object,
3468 const Symbol_value<32>* psymval,
3469 Arm_address relative_address_base)
3470 {
3471 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3472 Valtype* wv = reinterpret_cast<Valtype*>(view);
3473 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3474 Valtype addend = This::extract_arm_movw_movt_addend(val);
3475 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3476 val = This::insert_val_arm_movw_movt(val, x);
3477 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3478 // FIXME: IHI0044D says that we should check for overflow.
3479 return This::STATUS_OKAY;
3480 }
3481
3482 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3483 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3484 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3485 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3486 static inline typename This::Status
3487 thm_movw(unsigned char* view,
3488 const Sized_relobj_file<32, big_endian>* object,
3489 const Symbol_value<32>* psymval,
3490 Arm_address relative_address_base,
3491 Arm_address thumb_bit,
3492 bool check_overflow)
3493 {
3494 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3495 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3496 Valtype* wv = reinterpret_cast<Valtype*>(view);
3497 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3498 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3499 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3500 Reltype x =
3501 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3502 val = This::insert_val_thumb_movw_movt(val, x);
3503 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3504 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3505 return ((check_overflow && Bits<16>::has_overflow32(x))
3506 ? This::STATUS_OVERFLOW
3507 : This::STATUS_OKAY);
3508 }
3509
3510 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3511 // R_ARM_THM_MOVT_PREL: S + A - P
3512 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3513 static inline typename This::Status
3514 thm_movt(unsigned char* view,
3515 const Sized_relobj_file<32, big_endian>* object,
3516 const Symbol_value<32>* psymval,
3517 Arm_address relative_address_base)
3518 {
3519 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3520 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3521 Valtype* wv = reinterpret_cast<Valtype*>(view);
3522 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3523 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3524 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3525 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3526 val = This::insert_val_thumb_movw_movt(val, x);
3527 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3528 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3529 return This::STATUS_OKAY;
3530 }
3531
3532 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3533 static inline typename This::Status
3534 thm_alu11(unsigned char* view,
3535 const Sized_relobj_file<32, big_endian>* object,
3536 const Symbol_value<32>* psymval,
3537 Arm_address address,
3538 Arm_address thumb_bit)
3539 {
3540 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3541 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3542 Valtype* wv = reinterpret_cast<Valtype*>(view);
3543 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3544 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3545
3546 // f e d c b|a|9|8 7 6 5|4|3 2 1 0||f|e d c|b a 9 8|7 6 5 4 3 2 1 0
3547 // -----------------------------------------------------------------------
3548 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3549 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3550 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3551 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3552 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3553 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3554
3555 // Determine a sign for the addend.
3556 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3557 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3558 // Thumb2 addend encoding:
3559 // imm12 := i | imm3 | imm8
3560 int32_t addend = (insn & 0xff)
3561 | ((insn & 0x00007000) >> 4)
3562 | ((insn & 0x04000000) >> 15);
3563 // Apply a sign to the added.
3564 addend *= sign;
3565
3566 int32_t x = (psymval->value(object, addend) | thumb_bit)
3567 - (address & 0xfffffffc);
3568 Reltype val = abs(x);
3569 // Mask out the value and a distinct part of the ADD/SUB opcode
3570 // (bits 7:5 of opword).
3571 insn = (insn & 0xfb0f8f00)
3572 | (val & 0xff)
3573 | ((val & 0x700) << 4)
3574 | ((val & 0x800) << 15);
3575 // Set the opcode according to whether the value to go in the
3576 // place is negative.
3577 if (x < 0)
3578 insn |= 0x00a00000;
3579
3580 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3581 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3582 return ((val > 0xfff) ?
3583 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3584 }
3585
3586 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3587 static inline typename This::Status
3588 thm_pc8(unsigned char* view,
3589 const Sized_relobj_file<32, big_endian>* object,
3590 const Symbol_value<32>* psymval,
3591 Arm_address address)
3592 {
3593 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3594 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3595 Valtype* wv = reinterpret_cast<Valtype*>(view);
3596 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3597 Reltype addend = ((insn & 0x00ff) << 2);
3598 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3599 Reltype val = abs(x);
3600 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3601
3602 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3603 return ((val > 0x03fc)
3604 ? This::STATUS_OVERFLOW
3605 : This::STATUS_OKAY);
3606 }
3607
3608 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3609 static inline typename This::Status
3610 thm_pc12(unsigned char* view,
3611 const Sized_relobj_file<32, big_endian>* object,
3612 const Symbol_value<32>* psymval,
3613 Arm_address address)
3614 {
3615 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3616 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3617 Valtype* wv = reinterpret_cast<Valtype*>(view);
3618 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3619 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3620 // Determine a sign for the addend (positive if the U bit is 1).
3621 const int sign = (insn & 0x00800000) ? 1 : -1;
3622 int32_t addend = (insn & 0xfff);
3623 // Apply a sign to the added.
3624 addend *= sign;
3625
3626 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3627 Reltype val = abs(x);
3628 // Mask out and apply the value and the U bit.
3629 insn = (insn & 0xff7ff000) | (val & 0xfff);
3630 // Set the U bit according to whether the value to go in the
3631 // place is positive.
3632 if (x >= 0)
3633 insn |= 0x00800000;
3634
3635 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3636 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3637 return ((val > 0xfff) ?
3638 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3639 }
3640
3641 // R_ARM_V4BX
3642 static inline typename This::Status
3643 v4bx(const Relocate_info<32, big_endian>* relinfo,
3644 unsigned char* view,
3645 const Arm_relobj<big_endian>* object,
3646 const Arm_address address,
3647 const bool is_interworking)
3648 {
3649
3650 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3651 Valtype* wv = reinterpret_cast<Valtype*>(view);
3652 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3653
3654 // Ensure that we have a BX instruction.
3655 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3656 const uint32_t reg = (val & 0xf);
3657 if (is_interworking && reg != 0xf)
3658 {
3659 Stub_table<big_endian>* stub_table =
3660 object->stub_table(relinfo->data_shndx);
3661 gold_assert(stub_table != NULL);
3662
3663 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3664 gold_assert(stub != NULL);
3665
3666 int32_t veneer_address =
3667 stub_table->address() + stub->offset() - 8 - address;
3668 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3669 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3670 // Replace with a branch to veneer (B <addr>)
3671 val = (val & 0xf0000000) | 0x0a000000
3672 | ((veneer_address >> 2) & 0x00ffffff);
3673 }
3674 else
3675 {
3676 // Preserve Rm (lowest four bits) and the condition code
3677 // (highest four bits). Other bits encode MOV PC,Rm.
3678 val = (val & 0xf000000f) | 0x01a0f000;
3679 }
3680 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3681 return This::STATUS_OKAY;
3682 }
3683
3684 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3685 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3686 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3687 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3688 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3689 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3690 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3691 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3692 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3693 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3694 static inline typename This::Status
3695 arm_grp_alu(unsigned char* view,
3696 const Sized_relobj_file<32, big_endian>* object,
3697 const Symbol_value<32>* psymval,
3698 const int group,
3699 Arm_address address,
3700 Arm_address thumb_bit,
3701 bool check_overflow)
3702 {
3703 gold_assert(group >= 0 && group < 3);
3704 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3705 Valtype* wv = reinterpret_cast<Valtype*>(view);
3706 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3707
3708 // ALU group relocations are allowed only for the ADD/SUB instructions.
3709 // (0x00800000 - ADD, 0x00400000 - SUB)
3710 const Valtype opcode = insn & 0x01e00000;
3711 if (opcode != 0x00800000 && opcode != 0x00400000)
3712 return This::STATUS_BAD_RELOC;
3713
3714 // Determine a sign for the addend.
3715 const int sign = (opcode == 0x00800000) ? 1 : -1;
3716 // shifter = rotate_imm * 2
3717 const uint32_t shifter = (insn & 0xf00) >> 7;
3718 // Initial addend value.
3719 int32_t addend = insn & 0xff;
3720 // Rotate addend right by shifter.
3721 addend = (addend >> shifter) | (addend << (32 - shifter));
3722 // Apply a sign to the added.
3723 addend *= sign;
3724
3725 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3726 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3727 // Check for overflow if required
3728 if (check_overflow
3729 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3730 return This::STATUS_OVERFLOW;
3731
3732 // Mask out the value and the ADD/SUB part of the opcode; take care
3733 // not to destroy the S bit.
3734 insn &= 0xff1ff000;
3735 // Set the opcode according to whether the value to go in the
3736 // place is negative.
3737 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3738 // Encode the offset (encoded Gn).
3739 insn |= gn;
3740
3741 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3742 return This::STATUS_OKAY;
3743 }
3744
3745 // R_ARM_LDR_PC_G0: S + A - P
3746 // R_ARM_LDR_PC_G1: S + A - P
3747 // R_ARM_LDR_PC_G2: S + A - P
3748 // R_ARM_LDR_SB_G0: S + A - B(S)
3749 // R_ARM_LDR_SB_G1: S + A - B(S)
3750 // R_ARM_LDR_SB_G2: S + A - B(S)
3751 static inline typename This::Status
3752 arm_grp_ldr(unsigned char* view,
3753 const Sized_relobj_file<32, big_endian>* object,
3754 const Symbol_value<32>* psymval,
3755 const int group,
3756 Arm_address address)
3757 {
3758 gold_assert(group >= 0 && group < 3);
3759 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3760 Valtype* wv = reinterpret_cast<Valtype*>(view);
3761 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3762
3763 const int sign = (insn & 0x00800000) ? 1 : -1;
3764 int32_t addend = (insn & 0xfff) * sign;
3765 int32_t x = (psymval->value(object, addend) - address);
3766 // Calculate the relevant G(n-1) value to obtain this stage residual.
3767 Valtype residual =
3768 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3769 if (residual >= 0x1000)
3770 return This::STATUS_OVERFLOW;
3771
3772 // Mask out the value and U bit.
3773 insn &= 0xff7ff000;
3774 // Set the U bit for non-negative values.
3775 if (x >= 0)
3776 insn |= 0x00800000;
3777 insn |= residual;
3778
3779 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3780 return This::STATUS_OKAY;
3781 }
3782
3783 // R_ARM_LDRS_PC_G0: S + A - P
3784 // R_ARM_LDRS_PC_G1: S + A - P
3785 // R_ARM_LDRS_PC_G2: S + A - P
3786 // R_ARM_LDRS_SB_G0: S + A - B(S)
3787 // R_ARM_LDRS_SB_G1: S + A - B(S)
3788 // R_ARM_LDRS_SB_G2: S + A - B(S)
3789 static inline typename This::Status
3790 arm_grp_ldrs(unsigned char* view,
3791 const Sized_relobj_file<32, big_endian>* object,
3792 const Symbol_value<32>* psymval,
3793 const int group,
3794 Arm_address address)
3795 {
3796 gold_assert(group >= 0 && group < 3);
3797 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3798 Valtype* wv = reinterpret_cast<Valtype*>(view);
3799 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3800
3801 const int sign = (insn & 0x00800000) ? 1 : -1;
3802 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3803 int32_t x = (psymval->value(object, addend) - address);
3804 // Calculate the relevant G(n-1) value to obtain this stage residual.
3805 Valtype residual =
3806 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3807 if (residual >= 0x100)
3808 return This::STATUS_OVERFLOW;
3809
3810 // Mask out the value and U bit.
3811 insn &= 0xff7ff0f0;
3812 // Set the U bit for non-negative values.
3813 if (x >= 0)
3814 insn |= 0x00800000;
3815 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3816
3817 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3818 return This::STATUS_OKAY;
3819 }
3820
3821 // R_ARM_LDC_PC_G0: S + A - P
3822 // R_ARM_LDC_PC_G1: S + A - P
3823 // R_ARM_LDC_PC_G2: S + A - P
3824 // R_ARM_LDC_SB_G0: S + A - B(S)
3825 // R_ARM_LDC_SB_G1: S + A - B(S)
3826 // R_ARM_LDC_SB_G2: S + A - B(S)
3827 static inline typename This::Status
3828 arm_grp_ldc(unsigned char* view,
3829 const Sized_relobj_file<32, big_endian>* object,
3830 const Symbol_value<32>* psymval,
3831 const int group,
3832 Arm_address address)
3833 {
3834 gold_assert(group >= 0 && group < 3);
3835 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3836 Valtype* wv = reinterpret_cast<Valtype*>(view);
3837 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3838
3839 const int sign = (insn & 0x00800000) ? 1 : -1;
3840 int32_t addend = ((insn & 0xff) << 2) * sign;
3841 int32_t x = (psymval->value(object, addend) - address);
3842 // Calculate the relevant G(n-1) value to obtain this stage residual.
3843 Valtype residual =
3844 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3845 if ((residual & 0x3) != 0 || residual >= 0x400)
3846 return This::STATUS_OVERFLOW;
3847
3848 // Mask out the value and U bit.
3849 insn &= 0xff7fff00;
3850 // Set the U bit for non-negative values.
3851 if (x >= 0)
3852 insn |= 0x00800000;
3853 insn |= (residual >> 2);
3854
3855 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3856 return This::STATUS_OKAY;
3857 }
3858 };
3859
3860 // Relocate ARM long branches. This handles relocation types
3861 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3862 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3863 // undefined and we do not use PLT in this relocation. In such a case,
3864 // the branch is converted into an NOP.
3865
3866 template<bool big_endian>
3867 typename Arm_relocate_functions<big_endian>::Status
3868 Arm_relocate_functions<big_endian>::arm_branch_common(
3869 unsigned int r_type,
3870 const Relocate_info<32, big_endian>* relinfo,
3871 unsigned char* view,
3872 const Sized_symbol<32>* gsym,
3873 const Arm_relobj<big_endian>* object,
3874 unsigned int r_sym,
3875 const Symbol_value<32>* psymval,
3876 Arm_address address,
3877 Arm_address thumb_bit,
3878 bool is_weakly_undefined_without_plt)
3879 {
3880 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3881 Valtype* wv = reinterpret_cast<Valtype*>(view);
3882 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3883
3884 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3885 && ((val & 0x0f000000UL) == 0x0a000000UL);
3886 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3887 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3888 && ((val & 0x0f000000UL) == 0x0b000000UL);
3889 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3890 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3891
3892 // Check that the instruction is valid.
3893 if (r_type == elfcpp::R_ARM_CALL)
3894 {
3895 if (!insn_is_uncond_bl && !insn_is_blx)
3896 return This::STATUS_BAD_RELOC;
3897 }
3898 else if (r_type == elfcpp::R_ARM_JUMP24)
3899 {
3900 if (!insn_is_b && !insn_is_cond_bl)
3901 return This::STATUS_BAD_RELOC;
3902 }
3903 else if (r_type == elfcpp::R_ARM_PLT32)
3904 {
3905 if (!insn_is_any_branch)
3906 return This::STATUS_BAD_RELOC;
3907 }
3908 else if (r_type == elfcpp::R_ARM_XPC25)
3909 {
3910 // FIXME: AAELF document IH0044C does not say much about it other
3911 // than it being obsolete.
3912 if (!insn_is_any_branch)
3913 return This::STATUS_BAD_RELOC;
3914 }
3915 else
3916 gold_unreachable();
3917
3918 // A branch to an undefined weak symbol is turned into a jump to
3919 // the next instruction unless a PLT entry will be created.
3920 // Do the same for local undefined symbols.
3921 // The jump to the next instruction is optimized as a NOP depending
3922 // on the architecture.
3923 const Target_arm<big_endian>* arm_target =
3924 Target_arm<big_endian>::default_target();
3925 if (is_weakly_undefined_without_plt)
3926 {
3927 gold_assert(!parameters->options().relocatable());
3928 Valtype cond = val & 0xf0000000U;
3929 if (arm_target->may_use_arm_nop())
3930 val = cond | 0x0320f000;
3931 else
3932 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3933 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3934 return This::STATUS_OKAY;
3935 }
3936
3937 Valtype addend = Bits<26>::sign_extend32(val << 2);
3938 Valtype branch_target = psymval->value(object, addend);
3939 int32_t branch_offset = branch_target - address;
3940
3941 // We need a stub if the branch offset is too large or if we need
3942 // to switch mode.
3943 bool may_use_blx = arm_target->may_use_v5t_interworking();
3944 Reloc_stub* stub = NULL;
3945
3946 if (!parameters->options().relocatable()
3947 && (Bits<26>::has_overflow32(branch_offset)
3948 || ((thumb_bit != 0)
3949 && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))))
3950 {
3951 Valtype unadjusted_branch_target = psymval->value(object, 0);
3952
3953 Stub_type stub_type =
3954 Reloc_stub::stub_type_for_reloc(r_type, address,
3955 unadjusted_branch_target,
3956 (thumb_bit != 0));
3957 if (stub_type != arm_stub_none)
3958 {
3959 Stub_table<big_endian>* stub_table =
3960 object->stub_table(relinfo->data_shndx);
3961 gold_assert(stub_table != NULL);
3962
3963 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3964 stub = stub_table->find_reloc_stub(stub_key);
3965 gold_assert(stub != NULL);
3966 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3967 branch_target = stub_table->address() + stub->offset() + addend;
3968 branch_offset = branch_target - address;
3969 gold_assert(!Bits<26>::has_overflow32(branch_offset));
3970 }
3971 }
3972
3973 // At this point, if we still need to switch mode, the instruction
3974 // must either be a BLX or a BL that can be converted to a BLX.
3975 if (thumb_bit != 0)
3976 {
3977 // Turn BL to BLX.
3978 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3979 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3980 }
3981
3982 val = Bits<32>::bit_select32(val, (branch_offset >> 2), 0xffffffUL);
3983 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3984 return (Bits<26>::has_overflow32(branch_offset)
3985 ? This::STATUS_OVERFLOW
3986 : This::STATUS_OKAY);
3987 }
3988
3989 // Relocate THUMB long branches. This handles relocation types
3990 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3991 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3992 // undefined and we do not use PLT in this relocation. In such a case,
3993 // the branch is converted into an NOP.
3994
3995 template<bool big_endian>
3996 typename Arm_relocate_functions<big_endian>::Status
3997 Arm_relocate_functions<big_endian>::thumb_branch_common(
3998 unsigned int r_type,
3999 const Relocate_info<32, big_endian>* relinfo,
4000 unsigned char* view,
4001 const Sized_symbol<32>* gsym,
4002 const Arm_relobj<big_endian>* object,
4003 unsigned int r_sym,
4004 const Symbol_value<32>* psymval,
4005 Arm_address address,
4006 Arm_address thumb_bit,
4007 bool is_weakly_undefined_without_plt)
4008 {
4009 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4010 Valtype* wv = reinterpret_cast<Valtype*>(view);
4011 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4012 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4013
4014 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
4015 // into account.
4016 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
4017 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
4018
4019 // Check that the instruction is valid.
4020 if (r_type == elfcpp::R_ARM_THM_CALL)
4021 {
4022 if (!is_bl_insn && !is_blx_insn)
4023 return This::STATUS_BAD_RELOC;
4024 }
4025 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
4026 {
4027 // This cannot be a BLX.
4028 if (!is_bl_insn)
4029 return This::STATUS_BAD_RELOC;
4030 }
4031 else if (r_type == elfcpp::R_ARM_THM_XPC22)
4032 {
4033 // Check for Thumb to Thumb call.
4034 if (!is_blx_insn)
4035 return This::STATUS_BAD_RELOC;
4036 if (thumb_bit != 0)
4037 {
4038 gold_warning(_("%s: Thumb BLX instruction targets "
4039 "thumb function '%s'."),
4040 object->name().c_str(),
4041 (gsym ? gsym->name() : "(local)"));
4042 // Convert BLX to BL.
4043 lower_insn |= 0x1000U;
4044 }
4045 }
4046 else
4047 gold_unreachable();
4048
4049 // A branch to an undefined weak symbol is turned into a jump to
4050 // the next instruction unless a PLT entry will be created.
4051 // The jump to the next instruction is optimized as a NOP.W for
4052 // Thumb-2 enabled architectures.
4053 const Target_arm<big_endian>* arm_target =
4054 Target_arm<big_endian>::default_target();
4055 if (is_weakly_undefined_without_plt)
4056 {
4057 gold_assert(!parameters->options().relocatable());
4058 if (arm_target->may_use_thumb2_nop())
4059 {
4060 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
4061 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
4062 }
4063 else
4064 {
4065 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
4066 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
4067 }
4068 return This::STATUS_OKAY;
4069 }
4070
4071 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
4072 Arm_address branch_target = psymval->value(object, addend);
4073
4074 // For BLX, bit 1 of target address comes from bit 1 of base address.
4075 bool may_use_blx = arm_target->may_use_v5t_interworking();
4076 if (thumb_bit == 0 && may_use_blx)
4077 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4078
4079 int32_t branch_offset = branch_target - address;
4080
4081 // We need a stub if the branch offset is too large or if we need
4082 // to switch mode.
4083 bool thumb2 = arm_target->using_thumb2();
4084 if (!parameters->options().relocatable()
4085 && ((!thumb2 && Bits<23>::has_overflow32(branch_offset))
4086 || (thumb2 && Bits<25>::has_overflow32(branch_offset))
4087 || ((thumb_bit == 0)
4088 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4089 || r_type == elfcpp::R_ARM_THM_JUMP24))))
4090 {
4091 Arm_address unadjusted_branch_target = psymval->value(object, 0);
4092
4093 Stub_type stub_type =
4094 Reloc_stub::stub_type_for_reloc(r_type, address,
4095 unadjusted_branch_target,
4096 (thumb_bit != 0));
4097
4098 if (stub_type != arm_stub_none)
4099 {
4100 Stub_table<big_endian>* stub_table =
4101 object->stub_table(relinfo->data_shndx);
4102 gold_assert(stub_table != NULL);
4103
4104 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
4105 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
4106 gold_assert(stub != NULL);
4107 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
4108 branch_target = stub_table->address() + stub->offset() + addend;
4109 if (thumb_bit == 0 && may_use_blx)
4110 branch_target = Bits<32>::bit_select32(branch_target, address, 0x2);
4111 branch_offset = branch_target - address;
4112 }
4113 }
4114
4115 // At this point, if we still need to switch mode, the instruction
4116 // must either be a BLX or a BL that can be converted to a BLX.
4117 if (thumb_bit == 0)
4118 {
4119 gold_assert(may_use_blx
4120 && (r_type == elfcpp::R_ARM_THM_CALL
4121 || r_type == elfcpp::R_ARM_THM_XPC22));
4122 // Make sure this is a BLX.
4123 lower_insn &= ~0x1000U;
4124 }
4125 else
4126 {
4127 // Make sure this is a BL.
4128 lower_insn |= 0x1000U;
4129 }
4130
4131 // For a BLX instruction, make sure that the relocation is rounded up
4132 // to a word boundary. This follows the semantics of the instruction
4133 // which specifies that bit 1 of the target address will come from bit
4134 // 1 of the base address.
4135 if ((lower_insn & 0x5000U) == 0x4000U)
4136 gold_assert((branch_offset & 3) == 0);
4137
4138 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
4139 // We use the Thumb-2 encoding, which is safe even if dealing with
4140 // a Thumb-1 instruction by virtue of our overflow check above. */
4141 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
4142 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
4143
4144 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4145 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4146
4147 gold_assert(!Bits<25>::has_overflow32(branch_offset));
4148
4149 return ((thumb2
4150 ? Bits<25>::has_overflow32(branch_offset)
4151 : Bits<23>::has_overflow32(branch_offset))
4152 ? This::STATUS_OVERFLOW
4153 : This::STATUS_OKAY);
4154 }
4155
4156 // Relocate THUMB-2 long conditional branches.
4157 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
4158 // undefined and we do not use PLT in this relocation. In such a case,
4159 // the branch is converted into an NOP.
4160
4161 template<bool big_endian>
4162 typename Arm_relocate_functions<big_endian>::Status
4163 Arm_relocate_functions<big_endian>::thm_jump19(
4164 unsigned char* view,
4165 const Arm_relobj<big_endian>* object,
4166 const Symbol_value<32>* psymval,
4167 Arm_address address,
4168 Arm_address thumb_bit)
4169 {
4170 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
4171 Valtype* wv = reinterpret_cast<Valtype*>(view);
4172 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
4173 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
4174 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
4175
4176 Arm_address branch_target = psymval->value(object, addend);
4177 int32_t branch_offset = branch_target - address;
4178
4179 // ??? Should handle interworking? GCC might someday try to
4180 // use this for tail calls.
4181 // FIXME: We do support thumb entry to PLT yet.
4182 if (thumb_bit == 0)
4183 {
4184 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
4185 return This::STATUS_BAD_RELOC;
4186 }
4187
4188 // Put RELOCATION back into the insn.
4189 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
4190 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
4191
4192 // Put the relocated value back in the object file:
4193 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
4194 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
4195
4196 return (Bits<21>::has_overflow32(branch_offset)
4197 ? This::STATUS_OVERFLOW
4198 : This::STATUS_OKAY);
4199 }
4200
4201 // Get the GOT section, creating it if necessary.
4202
4203 template<bool big_endian>
4204 Arm_output_data_got<big_endian>*
4205 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
4206 {
4207 if (this->got_ == NULL)
4208 {
4209 gold_assert(symtab != NULL && layout != NULL);
4210
4211 // When using -z now, we can treat .got as a relro section.
4212 // Without -z now, it is modified after program startup by lazy
4213 // PLT relocations.
4214 bool is_got_relro = parameters->options().now();
4215 Output_section_order got_order = (is_got_relro
4216 ? ORDER_RELRO_LAST
4217 : ORDER_DATA);
4218
4219 // Unlike some targets (.e.g x86), ARM does not use separate .got and
4220 // .got.plt sections in output. The output .got section contains both
4221 // PLT and non-PLT GOT entries.
4222 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
4223
4224 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4225 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4226 this->got_, got_order, is_got_relro);
4227
4228 // The old GNU linker creates a .got.plt section. We just
4229 // create another set of data in the .got section. Note that we
4230 // always create a PLT if we create a GOT, although the PLT
4231 // might be empty.
4232 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4233 layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4234 (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE),
4235 this->got_plt_, got_order, is_got_relro);
4236
4237 // The first three entries are reserved.
4238 this->got_plt_->set_current_data_size(3 * 4);
4239
4240 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4241 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4242 Symbol_table::PREDEFINED,
4243 this->got_plt_,
4244 0, 0, elfcpp::STT_OBJECT,
4245 elfcpp::STB_LOCAL,
4246 elfcpp::STV_HIDDEN, 0,
4247 false, false);
4248 }
4249 return this->got_;
4250 }
4251
4252 // Get the dynamic reloc section, creating it if necessary.
4253
4254 template<bool big_endian>
4255 typename Target_arm<big_endian>::Reloc_section*
4256 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4257 {
4258 if (this->rel_dyn_ == NULL)
4259 {
4260 gold_assert(layout != NULL);
4261 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4262 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4263 elfcpp::SHF_ALLOC, this->rel_dyn_,
4264 ORDER_DYNAMIC_RELOCS, false);
4265 }
4266 return this->rel_dyn_;
4267 }
4268
4269 // Insn_template methods.
4270
4271 // Return byte size of an instruction template.
4272
4273 size_t
4274 Insn_template::size() const
4275 {
4276 switch (this->type())
4277 {
4278 case THUMB16_TYPE:
4279 case THUMB16_SPECIAL_TYPE:
4280 return 2;
4281 case ARM_TYPE:
4282 case THUMB32_TYPE:
4283 case DATA_TYPE:
4284 return 4;
4285 default:
4286 gold_unreachable();
4287 }
4288 }
4289
4290 // Return alignment of an instruction template.
4291
4292 unsigned
4293 Insn_template::alignment() const
4294 {
4295 switch (this->type())
4296 {
4297 case THUMB16_TYPE:
4298 case THUMB16_SPECIAL_TYPE:
4299 case THUMB32_TYPE:
4300 return 2;
4301 case ARM_TYPE:
4302 case DATA_TYPE:
4303 return 4;
4304 default:
4305 gold_unreachable();
4306 }
4307 }
4308
4309 // Stub_template methods.
4310
4311 Stub_template::Stub_template(
4312 Stub_type type, const Insn_template* insns,
4313 size_t insn_count)
4314 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4315 entry_in_thumb_mode_(false), relocs_()
4316 {
4317 off_t offset = 0;
4318
4319 // Compute byte size and alignment of stub template.
4320 for (size_t i = 0; i < insn_count; i++)
4321 {
4322 unsigned insn_alignment = insns[i].alignment();
4323 size_t insn_size = insns[i].size();
4324 gold_assert((offset & (insn_alignment - 1)) == 0);
4325 this->alignment_ = std::max(this->alignment_, insn_alignment);
4326 switch (insns[i].type())
4327 {
4328 case Insn_template::THUMB16_TYPE:
4329 case Insn_template::THUMB16_SPECIAL_TYPE:
4330 if (i == 0)
4331 this->entry_in_thumb_mode_ = true;
4332 break;
4333
4334 case Insn_template::THUMB32_TYPE:
4335 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4336 this->relocs_.push_back(Reloc(i, offset));
4337 if (i == 0)
4338 this->entry_in_thumb_mode_ = true;
4339 break;
4340
4341 case Insn_template::ARM_TYPE:
4342 // Handle cases where the target is encoded within the
4343 // instruction.
4344 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4345 this->relocs_.push_back(Reloc(i, offset));
4346 break;
4347
4348 case Insn_template::DATA_TYPE:
4349 // Entry point cannot be data.
4350 gold_assert(i != 0);
4351 this->relocs_.push_back(Reloc(i, offset));
4352 break;
4353
4354 default:
4355 gold_unreachable();
4356 }
4357 offset += insn_size;
4358 }
4359 this->size_ = offset;
4360 }
4361
4362 // Stub methods.
4363
4364 // Template to implement do_write for a specific target endianness.
4365
4366 template<bool big_endian>
4367 void inline
4368 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4369 {
4370 const Stub_template* stub_template = this->stub_template();
4371 const Insn_template* insns = stub_template->insns();
4372
4373 // FIXME: We do not handle BE8 encoding yet.
4374 unsigned char* pov = view;
4375 for (size_t i = 0; i < stub_template->insn_count(); i++)
4376 {
4377 switch (insns[i].type())
4378 {
4379 case Insn_template::THUMB16_TYPE:
4380 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4381 break;
4382 case Insn_template::THUMB16_SPECIAL_TYPE:
4383 elfcpp::Swap<16, big_endian>::writeval(
4384 pov,
4385 this->thumb16_special(i));
4386 break;
4387 case Insn_template::THUMB32_TYPE:
4388 {
4389 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4390 uint32_t lo = insns[i].data() & 0xffff;
4391 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4392 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4393 }
4394 break;
4395 case Insn_template::ARM_TYPE:
4396 case Insn_template::DATA_TYPE:
4397 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4398 break;
4399 default:
4400 gold_unreachable();
4401 }
4402 pov += insns[i].size();
4403 }
4404 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4405 }
4406
4407 // Reloc_stub::Key methods.
4408
4409 // Dump a Key as a string for debugging.
4410
4411 std::string
4412 Reloc_stub::Key::name() const
4413 {
4414 if (this->r_sym_ == invalid_index)
4415 {
4416 // Global symbol key name
4417 // <stub-type>:<symbol name>:<addend>.
4418 const std::string sym_name = this->u_.symbol->name();
4419 // We need to print two hex number and two colons. So just add 100 bytes
4420 // to the symbol name size.
4421 size_t len = sym_name.size() + 100;
4422 char* buffer = new char[len];
4423 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4424 sym_name.c_str(), this->addend_);
4425 gold_assert(c > 0 && c < static_cast<int>(len));
4426 delete[] buffer;
4427 return std::string(buffer);
4428 }
4429 else
4430 {
4431 // local symbol key name
4432 // <stub-type>:<object>:<r_sym>:<addend>.
4433 const size_t len = 200;
4434 char buffer[len];
4435 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4436 this->u_.relobj, this->r_sym_, this->addend_);
4437 gold_assert(c > 0 && c < static_cast<int>(len));
4438 return std::string(buffer);
4439 }
4440 }
4441
4442 // Reloc_stub methods.
4443
4444 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4445 // LOCATION to DESTINATION.
4446 // This code is based on the arm_type_of_stub function in
4447 // bfd/elf32-arm.c. We have changed the interface a little to keep the Stub
4448 // class simple.
4449
4450 Stub_type
4451 Reloc_stub::stub_type_for_reloc(
4452 unsigned int r_type,
4453 Arm_address location,
4454 Arm_address destination,
4455 bool target_is_thumb)
4456 {
4457 Stub_type stub_type = arm_stub_none;
4458
4459 // This is a bit ugly but we want to avoid using a templated class for
4460 // big and little endianities.
4461 bool may_use_blx;
4462 bool should_force_pic_veneer;
4463 bool thumb2;
4464 bool thumb_only;
4465 if (parameters->target().is_big_endian())
4466 {
4467 const Target_arm<true>* big_endian_target =
4468 Target_arm<true>::default_target();
4469 may_use_blx = big_endian_target->may_use_v5t_interworking();
4470 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4471 thumb2 = big_endian_target->using_thumb2();
4472 thumb_only = big_endian_target->using_thumb_only();
4473 }
4474 else
4475 {
4476 const Target_arm<false>* little_endian_target =
4477 Target_arm<false>::default_target();
4478 may_use_blx = little_endian_target->may_use_v5t_interworking();
4479 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4480 thumb2 = little_endian_target->using_thumb2();
4481 thumb_only = little_endian_target->using_thumb_only();
4482 }
4483
4484 int64_t branch_offset;
4485 bool output_is_position_independent =
4486 parameters->options().output_is_position_independent();
4487 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4488 {
4489 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4490 // base address (instruction address + 4).
4491 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4492 destination = Bits<32>::bit_select32(destination, location, 0x2);
4493 branch_offset = static_cast<int64_t>(destination) - location;
4494
4495 // Handle cases where:
4496 // - this call goes too far (different Thumb/Thumb2 max
4497 // distance)
4498 // - it's a Thumb->Arm call and blx is not available, or it's a
4499 // Thumb->Arm branch (not bl). A stub is needed in this case.
4500 if ((!thumb2
4501 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4502 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4503 || (thumb2
4504 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4505 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4506 || ((!target_is_thumb)
4507 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4508 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4509 {
4510 if (target_is_thumb)
4511 {
4512 // Thumb to thumb.
4513 if (!thumb_only)
4514 {
4515 stub_type = (output_is_position_independent
4516 || should_force_pic_veneer)
4517 // PIC stubs.
4518 ? ((may_use_blx
4519 && (r_type == elfcpp::R_ARM_THM_CALL))
4520 // V5T and above. Stub starts with ARM code, so
4521 // we must be able to switch mode before
4522 // reaching it, which is only possible for 'bl'
4523 // (ie R_ARM_THM_CALL relocation).
4524 ? arm_stub_long_branch_any_thumb_pic
4525 // On V4T, use Thumb code only.
4526 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4527
4528 // non-PIC stubs.
4529 : ((may_use_blx
4530 && (r_type == elfcpp::R_ARM_THM_CALL))
4531 ? arm_stub_long_branch_any_any // V5T and above.
4532 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4533 }
4534 else
4535 {
4536 stub_type = (output_is_position_independent
4537 || should_force_pic_veneer)
4538 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4539 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4540 }
4541 }
4542 else
4543 {
4544 // Thumb to arm.
4545
4546 // FIXME: We should check that the input section is from an
4547 // object that has interwork enabled.
4548
4549 stub_type = (output_is_position_independent
4550 || should_force_pic_veneer)
4551 // PIC stubs.
4552 ? ((may_use_blx
4553 && (r_type == elfcpp::R_ARM_THM_CALL))
4554 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4555 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4556
4557 // non-PIC stubs.
4558 : ((may_use_blx
4559 && (r_type == elfcpp::R_ARM_THM_CALL))
4560 ? arm_stub_long_branch_any_any // V5T and above.
4561 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4562
4563 // Handle v4t short branches.
4564 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4565 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4566 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4567 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4568 }
4569 }
4570 }
4571 else if (r_type == elfcpp::R_ARM_CALL
4572 || r_type == elfcpp::R_ARM_JUMP24
4573 || r_type == elfcpp::R_ARM_PLT32)
4574 {
4575 branch_offset = static_cast<int64_t>(destination) - location;
4576 if (target_is_thumb)
4577 {
4578 // Arm to thumb.
4579
4580 // FIXME: We should check that the input section is from an
4581 // object that has interwork enabled.
4582
4583 // We have an extra 2-bytes reach because of
4584 // the mode change (bit 24 (H) of BLX encoding).
4585 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4586 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4587 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4588 || (r_type == elfcpp::R_ARM_JUMP24)
4589 || (r_type == elfcpp::R_ARM_PLT32))
4590 {
4591 stub_type = (output_is_position_independent
4592 || should_force_pic_veneer)
4593 // PIC stubs.
4594 ? (may_use_blx
4595 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4596 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4597
4598 // non-PIC stubs.
4599 : (may_use_blx
4600 ? arm_stub_long_branch_any_any // V5T and above.
4601 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4602 }
4603 }
4604 else
4605 {
4606 // Arm to arm.
4607 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4608 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4609 {
4610 stub_type = (output_is_position_independent
4611 || should_force_pic_veneer)
4612 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4613 : arm_stub_long_branch_any_any; /// non-PIC.
4614 }
4615 }
4616 }
4617
4618 return stub_type;
4619 }
4620
4621 // Cortex_a8_stub methods.
4622
4623 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4624 // I is the position of the instruction template in the stub template.
4625
4626 uint16_t
4627 Cortex_a8_stub::do_thumb16_special(size_t i)
4628 {
4629 // The only use of this is to copy condition code from a conditional
4630 // branch being worked around to the corresponding conditional branch in
4631 // to the stub.
4632 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4633 && i == 0);
4634 uint16_t data = this->stub_template()->insns()[i].data();
4635 gold_assert((data & 0xff00U) == 0xd000U);
4636 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4637 return data;
4638 }
4639
4640 // Stub_factory methods.
4641
4642 Stub_factory::Stub_factory()
4643 {
4644 // The instruction template sequences are declared as static
4645 // objects and initialized first time the constructor runs.
4646
4647 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4648 // to reach the stub if necessary.
4649 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4650 {
4651 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4652 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4653 // dcd R_ARM_ABS32(X)
4654 };
4655
4656 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4657 // available.
4658 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4659 {
4660 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4661 Insn_template::arm_insn(0xe12fff1c), // bx ip
4662 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4663 // dcd R_ARM_ABS32(X)
4664 };
4665
4666 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4667 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4668 {
4669 Insn_template::thumb16_insn(0xb401), // push {r0}
4670 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4671 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4672 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4673 Insn_template::thumb16_insn(0x4760), // bx ip
4674 Insn_template::thumb16_insn(0xbf00), // nop
4675 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4676 // dcd R_ARM_ABS32(X)
4677 };
4678
4679 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4680 // allowed.
4681 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4682 {
4683 Insn_template::thumb16_insn(0x4778), // bx pc
4684 Insn_template::thumb16_insn(0x46c0), // nop
4685 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4686 Insn_template::arm_insn(0xe12fff1c), // bx ip
4687 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4688 // dcd R_ARM_ABS32(X)
4689 };
4690
4691 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4692 // available.
4693 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4694 {
4695 Insn_template::thumb16_insn(0x4778), // bx pc
4696 Insn_template::thumb16_insn(0x46c0), // nop
4697 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4698 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4699 // dcd R_ARM_ABS32(X)
4700 };
4701
4702 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4703 // one, when the destination is close enough.
4704 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4705 {
4706 Insn_template::thumb16_insn(0x4778), // bx pc
4707 Insn_template::thumb16_insn(0x46c0), // nop
4708 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4709 };
4710
4711 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4712 // blx to reach the stub if necessary.
4713 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4714 {
4715 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4716 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4717 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4718 // dcd R_ARM_REL32(X-4)
4719 };
4720
4721 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4722 // blx to reach the stub if necessary. We can not add into pc;
4723 // it is not guaranteed to mode switch (different in ARMv6 and
4724 // ARMv7).
4725 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4726 {
4727 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4728 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4729 Insn_template::arm_insn(0xe12fff1c), // bx ip
4730 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4731 // dcd R_ARM_REL32(X)
4732 };
4733
4734 // V4T ARM -> ARM long branch stub, PIC.
4735 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4736 {
4737 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4738 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4739 Insn_template::arm_insn(0xe12fff1c), // bx ip
4740 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4741 // dcd R_ARM_REL32(X)
4742 };
4743
4744 // V4T Thumb -> ARM long branch stub, PIC.
4745 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4746 {
4747 Insn_template::thumb16_insn(0x4778), // bx pc
4748 Insn_template::thumb16_insn(0x46c0), // nop
4749 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4750 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4751 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4752 // dcd R_ARM_REL32(X)
4753 };
4754
4755 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4756 // architectures.
4757 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4758 {
4759 Insn_template::thumb16_insn(0xb401), // push {r0}
4760 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4761 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4762 Insn_template::thumb16_insn(0x4484), // add ip, r0
4763 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4764 Insn_template::thumb16_insn(0x4760), // bx ip
4765 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4766 // dcd R_ARM_REL32(X)
4767 };
4768
4769 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4770 // allowed.
4771 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4772 {
4773 Insn_template::thumb16_insn(0x4778), // bx pc
4774 Insn_template::thumb16_insn(0x46c0), // nop
4775 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4776 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4777 Insn_template::arm_insn(0xe12fff1c), // bx ip
4778 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4779 // dcd R_ARM_REL32(X)
4780 };
4781
4782 // Cortex-A8 erratum-workaround stubs.
4783
4784 // Stub used for conditional branches (which may be beyond +/-1MB away,
4785 // so we can't use a conditional branch to reach this stub).
4786
4787 // original code:
4788 //
4789 // b<cond> X
4790 // after:
4791 //
4792 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4793 {
4794 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4795 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4796 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4797 // b.w X
4798 };
4799
4800 // Stub used for b.w and bl.w instructions.
4801
4802 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4803 {
4804 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4805 };
4806
4807 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4808 {
4809 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4810 };
4811
4812 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4813 // instruction (which switches to ARM mode) to point to this stub. Jump to
4814 // the real destination using an ARM-mode branch.
4815 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4816 {
4817 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4818 };
4819
4820 // Stub used to provide an interworking for R_ARM_V4BX relocation
4821 // (bx r[n] instruction).
4822 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4823 {
4824 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4825 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4826 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4827 };
4828
4829 // Fill in the stub template look-up table. Stub templates are constructed
4830 // per instance of Stub_factory for fast look-up without locking
4831 // in a thread-enabled environment.
4832
4833 this->stub_templates_[arm_stub_none] =
4834 new Stub_template(arm_stub_none, NULL, 0);
4835
4836 #define DEF_STUB(x) \
4837 do \
4838 { \
4839 size_t array_size \
4840 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4841 Stub_type type = arm_stub_##x; \
4842 this->stub_templates_[type] = \
4843 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4844 } \
4845 while (0);
4846
4847 DEF_STUBS
4848 #undef DEF_STUB
4849 }
4850
4851 // Stub_table methods.
4852
4853 // Remove all Cortex-A8 stub.
4854
4855 template<bool big_endian>
4856 void
4857 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4858 {
4859 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4860 p != this->cortex_a8_stubs_.end();
4861 ++p)
4862 delete p->second;
4863 this->cortex_a8_stubs_.clear();
4864 }
4865
4866 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4867
4868 template<bool big_endian>
4869 void
4870 Stub_table<big_endian>::relocate_stub(
4871 Stub* stub,
4872 const Relocate_info<32, big_endian>* relinfo,
4873 Target_arm<big_endian>* arm_target,
4874 Output_section* output_section,
4875 unsigned char* view,
4876 Arm_address address,
4877 section_size_type view_size)
4878 {
4879 const Stub_template* stub_template = stub->stub_template();
4880 if (stub_template->reloc_count() != 0)
4881 {
4882 // Adjust view to cover the stub only.
4883 section_size_type offset = stub->offset();
4884 section_size_type stub_size = stub_template->size();
4885 gold_assert(offset + stub_size <= view_size);
4886
4887 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4888 address + offset, stub_size);
4889 }
4890 }
4891
4892 // Relocate all stubs in this stub table.
4893
4894 template<bool big_endian>
4895 void
4896 Stub_table<big_endian>::relocate_stubs(
4897 const Relocate_info<32, big_endian>* relinfo,
4898 Target_arm<big_endian>* arm_target,
4899 Output_section* output_section,
4900 unsigned char* view,
4901 Arm_address address,
4902 section_size_type view_size)
4903 {
4904 // If we are passed a view bigger than the stub table's. we need to
4905 // adjust the view.
4906 gold_assert(address == this->address()
4907 && (view_size
4908 == static_cast<section_size_type>(this->data_size())));
4909
4910 // Relocate all relocation stubs.
4911 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4912 p != this->reloc_stubs_.end();
4913 ++p)
4914 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4915 address, view_size);
4916
4917 // Relocate all Cortex-A8 stubs.
4918 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4919 p != this->cortex_a8_stubs_.end();
4920 ++p)
4921 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4922 address, view_size);
4923
4924 // Relocate all ARM V4BX stubs.
4925 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4926 p != this->arm_v4bx_stubs_.end();
4927 ++p)
4928 {
4929 if (*p != NULL)
4930 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4931 address, view_size);
4932 }
4933 }
4934
4935 // Write out the stubs to file.
4936
4937 template<bool big_endian>
4938 void
4939 Stub_table<big_endian>::do_write(Output_file* of)
4940 {
4941 off_t offset = this->offset();
4942 const section_size_type oview_size =
4943 convert_to_section_size_type(this->data_size());
4944 unsigned char* const oview = of->get_output_view(offset, oview_size);
4945
4946 // Write relocation stubs.
4947 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4948 p != this->reloc_stubs_.end();
4949 ++p)
4950 {
4951 Reloc_stub* stub = p->second;
4952 Arm_address address = this->address() + stub->offset();
4953 gold_assert(address
4954 == align_address(address,
4955 stub->stub_template()->alignment()));
4956 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4957 big_endian);
4958 }
4959
4960 // Write Cortex-A8 stubs.
4961 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4962 p != this->cortex_a8_stubs_.end();
4963 ++p)
4964 {
4965 Cortex_a8_stub* stub = p->second;
4966 Arm_address address = this->address() + stub->offset();
4967 gold_assert(address
4968 == align_address(address,
4969 stub->stub_template()->alignment()));
4970 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4971 big_endian);
4972 }
4973
4974 // Write ARM V4BX relocation stubs.
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 Arm_address address = this->address() + (*p)->offset();
4983 gold_assert(address
4984 == align_address(address,
4985 (*p)->stub_template()->alignment()));
4986 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4987 big_endian);
4988 }
4989
4990 of->write_output_view(this->offset(), oview_size, oview);
4991 }
4992
4993 // Update the data size and address alignment of the stub table at the end
4994 // of a relaxation pass. Return true if either the data size or the
4995 // alignment changed in this relaxation pass.
4996
4997 template<bool big_endian>
4998 bool
4999 Stub_table<big_endian>::update_data_size_and_addralign()
5000 {
5001 // Go over all stubs in table to compute data size and address alignment.
5002 off_t size = this->reloc_stubs_size_;
5003 unsigned addralign = this->reloc_stubs_addralign_;
5004
5005 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5006 p != this->cortex_a8_stubs_.end();
5007 ++p)
5008 {
5009 const Stub_template* stub_template = p->second->stub_template();
5010 addralign = std::max(addralign, stub_template->alignment());
5011 size = (align_address(size, stub_template->alignment())
5012 + stub_template->size());
5013 }
5014
5015 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5016 p != this->arm_v4bx_stubs_.end();
5017 ++p)
5018 {
5019 if (*p == NULL)
5020 continue;
5021
5022 const Stub_template* stub_template = (*p)->stub_template();
5023 addralign = std::max(addralign, stub_template->alignment());
5024 size = (align_address(size, stub_template->alignment())
5025 + stub_template->size());
5026 }
5027
5028 // Check if either data size or alignment changed in this pass.
5029 // Update prev_data_size_ and prev_addralign_. These will be used
5030 // as the current data size and address alignment for the next pass.
5031 bool changed = size != this->prev_data_size_;
5032 this->prev_data_size_ = size;
5033
5034 if (addralign != this->prev_addralign_)
5035 changed = true;
5036 this->prev_addralign_ = addralign;
5037
5038 return changed;
5039 }
5040
5041 // Finalize the stubs. This sets the offsets of the stubs within the stub
5042 // table. It also marks all input sections needing Cortex-A8 workaround.
5043
5044 template<bool big_endian>
5045 void
5046 Stub_table<big_endian>::finalize_stubs()
5047 {
5048 off_t off = this->reloc_stubs_size_;
5049 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
5050 p != this->cortex_a8_stubs_.end();
5051 ++p)
5052 {
5053 Cortex_a8_stub* stub = p->second;
5054 const Stub_template* stub_template = stub->stub_template();
5055 uint64_t stub_addralign = stub_template->alignment();
5056 off = align_address(off, stub_addralign);
5057 stub->set_offset(off);
5058 off += stub_template->size();
5059
5060 // Mark input section so that we can determine later if a code section
5061 // needs the Cortex-A8 workaround quickly.
5062 Arm_relobj<big_endian>* arm_relobj =
5063 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
5064 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
5065 }
5066
5067 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
5068 p != this->arm_v4bx_stubs_.end();
5069 ++p)
5070 {
5071 if (*p == NULL)
5072 continue;
5073
5074 const Stub_template* stub_template = (*p)->stub_template();
5075 uint64_t stub_addralign = stub_template->alignment();
5076 off = align_address(off, stub_addralign);
5077 (*p)->set_offset(off);
5078 off += stub_template->size();
5079 }
5080
5081 gold_assert(off <= this->prev_data_size_);
5082 }
5083
5084 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
5085 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
5086 // of the address range seen by the linker.
5087
5088 template<bool big_endian>
5089 void
5090 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
5091 Target_arm<big_endian>* arm_target,
5092 unsigned char* view,
5093 Arm_address view_address,
5094 section_size_type view_size)
5095 {
5096 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
5097 for (Cortex_a8_stub_list::const_iterator p =
5098 this->cortex_a8_stubs_.lower_bound(view_address);
5099 ((p != this->cortex_a8_stubs_.end())
5100 && (p->first < (view_address + view_size)));
5101 ++p)
5102 {
5103 // We do not store the THUMB bit in the LSB of either the branch address
5104 // or the stub offset. There is no need to strip the LSB.
5105 Arm_address branch_address = p->first;
5106 const Cortex_a8_stub* stub = p->second;
5107 Arm_address stub_address = this->address() + stub->offset();
5108
5109 // Offset of the branch instruction relative to this view.
5110 section_size_type offset =
5111 convert_to_section_size_type(branch_address - view_address);
5112 gold_assert((offset + 4) <= view_size);
5113
5114 arm_target->apply_cortex_a8_workaround(stub, stub_address,
5115 view + offset, branch_address);
5116 }
5117 }
5118
5119 // Arm_input_section methods.
5120
5121 // Initialize an Arm_input_section.
5122
5123 template<bool big_endian>
5124 void
5125 Arm_input_section<big_endian>::init()
5126 {
5127 Relobj* relobj = this->relobj();
5128 unsigned int shndx = this->shndx();
5129
5130 // We have to cache original size, alignment and contents to avoid locking
5131 // the original file.
5132 this->original_addralign_ =
5133 convert_types<uint32_t, uint64_t>(relobj->section_addralign(shndx));
5134
5135 // This is not efficient but we expect only a small number of relaxed
5136 // input sections for stubs.
5137 section_size_type section_size;
5138 const unsigned char* section_contents =
5139 relobj->section_contents(shndx, &section_size, false);
5140 this->original_size_ =
5141 convert_types<uint32_t, uint64_t>(relobj->section_size(shndx));
5142
5143 gold_assert(this->original_contents_ == NULL);
5144 this->original_contents_ = new unsigned char[section_size];
5145 memcpy(this->original_contents_, section_contents, section_size);
5146
5147 // We want to make this look like the original input section after
5148 // output sections are finalized.
5149 Output_section* os = relobj->output_section(shndx);
5150 off_t offset = relobj->output_section_offset(shndx);
5151 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
5152 this->set_address(os->address() + offset);
5153 this->set_file_offset(os->offset() + offset);
5154
5155 this->set_current_data_size(this->original_size_);
5156 this->finalize_data_size();
5157 }
5158
5159 template<bool big_endian>
5160 void
5161 Arm_input_section<big_endian>::do_write(Output_file* of)
5162 {
5163 // We have to write out the original section content.
5164 gold_assert(this->original_contents_ != NULL);
5165 of->write(this->offset(), this->original_contents_,
5166 this->original_size_);
5167
5168 // If this owns a stub table and it is not empty, write it.
5169 if (this->is_stub_table_owner() && !this->stub_table_->empty())
5170 this->stub_table_->write(of);
5171 }
5172
5173 // Finalize data size.
5174
5175 template<bool big_endian>
5176 void
5177 Arm_input_section<big_endian>::set_final_data_size()
5178 {
5179 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5180
5181 if (this->is_stub_table_owner())
5182 {
5183 this->stub_table_->finalize_data_size();
5184 off = align_address(off, this->stub_table_->addralign());
5185 off += this->stub_table_->data_size();
5186 }
5187 this->set_data_size(off);
5188 }
5189
5190 // Reset address and file offset.
5191
5192 template<bool big_endian>
5193 void
5194 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
5195 {
5196 // Size of the original input section contents.
5197 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
5198
5199 // If this is a stub table owner, account for the stub table size.
5200 if (this->is_stub_table_owner())
5201 {
5202 Stub_table<big_endian>* stub_table = this->stub_table_;
5203
5204 // Reset the stub table's address and file offset. The
5205 // current data size for child will be updated after that.
5206 stub_table_->reset_address_and_file_offset();
5207 off = align_address(off, stub_table_->addralign());
5208 off += stub_table->current_data_size();
5209 }
5210
5211 this->set_current_data_size(off);
5212 }
5213
5214 // Arm_exidx_cantunwind methods.
5215
5216 // Write this to Output file OF for a fixed endianness.
5217
5218 template<bool big_endian>
5219 void
5220 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
5221 {
5222 off_t offset = this->offset();
5223 const section_size_type oview_size = 8;
5224 unsigned char* const oview = of->get_output_view(offset, oview_size);
5225
5226 Output_section* os = this->relobj_->output_section(this->shndx_);
5227 gold_assert(os != NULL);
5228
5229 Arm_relobj<big_endian>* arm_relobj =
5230 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
5231 Arm_address output_offset =
5232 arm_relobj->get_output_section_offset(this->shndx_);
5233 Arm_address section_start;
5234 section_size_type section_size;
5235
5236 // Find out the end of the text section referred by this.
5237 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5238 {
5239 section_start = os->address() + output_offset;
5240 const Arm_exidx_input_section* exidx_input_section =
5241 arm_relobj->exidx_input_section_by_link(this->shndx_);
5242 gold_assert(exidx_input_section != NULL);
5243 section_size =
5244 convert_to_section_size_type(exidx_input_section->text_size());
5245 }
5246 else
5247 {
5248 // Currently this only happens for a relaxed section.
5249 const Output_relaxed_input_section* poris =
5250 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5251 gold_assert(poris != NULL);
5252 section_start = poris->address();
5253 section_size = convert_to_section_size_type(poris->data_size());
5254 }
5255
5256 // We always append this to the end of an EXIDX section.
5257 Arm_address output_address = section_start + section_size;
5258
5259 // Write out the entry. The first word either points to the beginning
5260 // or after the end of a text section. The second word is the special
5261 // EXIDX_CANTUNWIND value.
5262 uint32_t prel31_offset = output_address - this->address();
5263 if (Bits<31>::has_overflow32(offset))
5264 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5265 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview,
5266 prel31_offset & 0x7fffffffU);
5267 elfcpp::Swap_unaligned<32, big_endian>::writeval(oview + 4,
5268 elfcpp::EXIDX_CANTUNWIND);
5269
5270 of->write_output_view(this->offset(), oview_size, oview);
5271 }
5272
5273 // Arm_exidx_merged_section methods.
5274
5275 // Constructor for Arm_exidx_merged_section.
5276 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5277 // SECTION_OFFSET_MAP points to a section offset map describing how
5278 // parts of the input section are mapped to output. DELETED_BYTES is
5279 // the number of bytes deleted from the EXIDX input section.
5280
5281 Arm_exidx_merged_section::Arm_exidx_merged_section(
5282 const Arm_exidx_input_section& exidx_input_section,
5283 const Arm_exidx_section_offset_map& section_offset_map,
5284 uint32_t deleted_bytes)
5285 : Output_relaxed_input_section(exidx_input_section.relobj(),
5286 exidx_input_section.shndx(),
5287 exidx_input_section.addralign()),
5288 exidx_input_section_(exidx_input_section),
5289 section_offset_map_(section_offset_map)
5290 {
5291 // If we retain or discard the whole EXIDX input section, we would
5292 // not be here.
5293 gold_assert(deleted_bytes != 0
5294 && deleted_bytes != this->exidx_input_section_.size());
5295
5296 // Fix size here so that we do not need to implement set_final_data_size.
5297 uint32_t size = exidx_input_section.size() - deleted_bytes;
5298 this->set_data_size(size);
5299 this->fix_data_size();
5300
5301 // Allocate buffer for section contents and build contents.
5302 this->section_contents_ = new unsigned char[size];
5303 }
5304
5305 // Build the contents of a merged EXIDX output section.
5306
5307 void
5308 Arm_exidx_merged_section::build_contents(
5309 const unsigned char* original_contents,
5310 section_size_type original_size)
5311 {
5312 // Go over spans of input offsets and write only those that are not
5313 // discarded.
5314 section_offset_type in_start = 0;
5315 section_offset_type out_start = 0;
5316 section_offset_type in_max =
5317 convert_types<section_offset_type>(original_size);
5318 section_offset_type out_max =
5319 convert_types<section_offset_type>(this->data_size());
5320 for (Arm_exidx_section_offset_map::const_iterator p =
5321 this->section_offset_map_.begin();
5322 p != this->section_offset_map_.end();
5323 ++p)
5324 {
5325 section_offset_type in_end = p->first;
5326 gold_assert(in_end >= in_start);
5327 section_offset_type out_end = p->second;
5328 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5329 if (out_end != -1)
5330 {
5331 size_t out_chunk_size =
5332 convert_types<size_t>(out_end - out_start + 1);
5333
5334 gold_assert(out_chunk_size == in_chunk_size
5335 && in_end < in_max && out_end < out_max);
5336
5337 memcpy(this->section_contents_ + out_start,
5338 original_contents + in_start,
5339 out_chunk_size);
5340 out_start += out_chunk_size;
5341 }
5342 in_start += in_chunk_size;
5343 }
5344 }
5345
5346 // Given an input OBJECT, an input section index SHNDX within that
5347 // object, and an OFFSET relative to the start of that input
5348 // section, return whether or not the corresponding offset within
5349 // the output section is known. If this function returns true, it
5350 // sets *POUTPUT to the output offset. The value -1 indicates that
5351 // this input offset is being discarded.
5352
5353 bool
5354 Arm_exidx_merged_section::do_output_offset(
5355 const Relobj* relobj,
5356 unsigned int shndx,
5357 section_offset_type offset,
5358 section_offset_type* poutput) const
5359 {
5360 // We only handle offsets for the original EXIDX input section.
5361 if (relobj != this->exidx_input_section_.relobj()
5362 || shndx != this->exidx_input_section_.shndx())
5363 return false;
5364
5365 section_offset_type section_size =
5366 convert_types<section_offset_type>(this->exidx_input_section_.size());
5367 if (offset < 0 || offset >= section_size)
5368 // Input offset is out of valid range.
5369 *poutput = -1;
5370 else
5371 {
5372 // We need to look up the section offset map to determine the output
5373 // offset. Find the reference point in map that is first offset
5374 // bigger than or equal to this offset.
5375 Arm_exidx_section_offset_map::const_iterator p =
5376 this->section_offset_map_.lower_bound(offset);
5377
5378 // The section offset maps are build such that this should not happen if
5379 // input offset is in the valid range.
5380 gold_assert(p != this->section_offset_map_.end());
5381
5382 // We need to check if this is dropped.
5383 section_offset_type ref = p->first;
5384 section_offset_type mapped_ref = p->second;
5385
5386 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5387 // Offset is present in output.
5388 *poutput = mapped_ref + (offset - ref);
5389 else
5390 // Offset is discarded owing to EXIDX entry merging.
5391 *poutput = -1;
5392 }
5393
5394 return true;
5395 }
5396
5397 // Write this to output file OF.
5398
5399 void
5400 Arm_exidx_merged_section::do_write(Output_file* of)
5401 {
5402 off_t offset = this->offset();
5403 const section_size_type oview_size = this->data_size();
5404 unsigned char* const oview = of->get_output_view(offset, oview_size);
5405
5406 Output_section* os = this->relobj()->output_section(this->shndx());
5407 gold_assert(os != NULL);
5408
5409 memcpy(oview, this->section_contents_, oview_size);
5410 of->write_output_view(this->offset(), oview_size, oview);
5411 }
5412
5413 // Arm_exidx_fixup methods.
5414
5415 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5416 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5417 // points to the end of the last seen EXIDX section.
5418
5419 void
5420 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5421 {
5422 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5423 && this->last_input_section_ != NULL)
5424 {
5425 Relobj* relobj = this->last_input_section_->relobj();
5426 unsigned int text_shndx = this->last_input_section_->link();
5427 Arm_exidx_cantunwind* cantunwind =
5428 new Arm_exidx_cantunwind(relobj, text_shndx);
5429 this->exidx_output_section_->add_output_section_data(cantunwind);
5430 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5431 }
5432 }
5433
5434 // Process an EXIDX section entry in input. Return whether this entry
5435 // can be deleted in the output. SECOND_WORD in the second word of the
5436 // EXIDX entry.
5437
5438 bool
5439 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5440 {
5441 bool delete_entry;
5442 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5443 {
5444 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5445 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5446 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5447 }
5448 else if ((second_word & 0x80000000) != 0)
5449 {
5450 // Inlined unwinding data. Merge if equal to previous.
5451 delete_entry = (merge_exidx_entries_
5452 && this->last_unwind_type_ == UT_INLINED_ENTRY
5453 && this->last_inlined_entry_ == second_word);
5454 this->last_unwind_type_ = UT_INLINED_ENTRY;
5455 this->last_inlined_entry_ = second_word;
5456 }
5457 else
5458 {
5459 // Normal table entry. In theory we could merge these too,
5460 // but duplicate entries are likely to be much less common.
5461 delete_entry = false;
5462 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5463 }
5464 return delete_entry;
5465 }
5466
5467 // Update the current section offset map during EXIDX section fix-up.
5468 // If there is no map, create one. INPUT_OFFSET is the offset of a
5469 // reference point, DELETED_BYTES is the number of deleted by in the
5470 // section so far. If DELETE_ENTRY is true, the reference point and
5471 // all offsets after the previous reference point are discarded.
5472
5473 void
5474 Arm_exidx_fixup::update_offset_map(
5475 section_offset_type input_offset,
5476 section_size_type deleted_bytes,
5477 bool delete_entry)
5478 {
5479 if (this->section_offset_map_ == NULL)
5480 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5481 section_offset_type output_offset;
5482 if (delete_entry)
5483 output_offset = Arm_exidx_input_section::invalid_offset;
5484 else
5485 output_offset = input_offset - deleted_bytes;
5486 (*this->section_offset_map_)[input_offset] = output_offset;
5487 }
5488
5489 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5490 // bytes deleted. SECTION_CONTENTS points to the contents of the EXIDX
5491 // section and SECTION_SIZE is the number of bytes pointed by SECTION_CONTENTS.
5492 // If some entries are merged, also store a pointer to a newly created
5493 // Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The caller
5494 // owns the map and is responsible for releasing it after use.
5495
5496 template<bool big_endian>
5497 uint32_t
5498 Arm_exidx_fixup::process_exidx_section(
5499 const Arm_exidx_input_section* exidx_input_section,
5500 const unsigned char* section_contents,
5501 section_size_type section_size,
5502 Arm_exidx_section_offset_map** psection_offset_map)
5503 {
5504 Relobj* relobj = exidx_input_section->relobj();
5505 unsigned shndx = exidx_input_section->shndx();
5506
5507 if ((section_size % 8) != 0)
5508 {
5509 // Something is wrong with this section. Better not touch it.
5510 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5511 relobj->name().c_str(), shndx);
5512 this->last_input_section_ = exidx_input_section;
5513 this->last_unwind_type_ = UT_NONE;
5514 return 0;
5515 }
5516
5517 uint32_t deleted_bytes = 0;
5518 bool prev_delete_entry = false;
5519 gold_assert(this->section_offset_map_ == NULL);
5520
5521 for (section_size_type i = 0; i < section_size; i += 8)
5522 {
5523 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5524 const Valtype* wv =
5525 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5526 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5527
5528 bool delete_entry = this->process_exidx_entry(second_word);
5529
5530 // Entry deletion causes changes in output offsets. We use a std::map
5531 // to record these. And entry (x, y) means input offset x
5532 // is mapped to output offset y. If y is invalid_offset, then x is
5533 // dropped in the output. Because of the way std::map::lower_bound
5534 // works, we record the last offset in a region w.r.t to keeping or
5535 // dropping. If there is no entry (x0, y0) for an input offset x0,
5536 // the output offset y0 of it is determined by the output offset y1 of
5537 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5538 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Otherwise, y1
5539 // y0 is also -1.
5540 if (delete_entry != prev_delete_entry && i != 0)
5541 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5542
5543 // Update total deleted bytes for this entry.
5544 if (delete_entry)
5545 deleted_bytes += 8;
5546
5547 prev_delete_entry = delete_entry;
5548 }
5549
5550 // If section offset map is not NULL, make an entry for the end of
5551 // section.
5552 if (this->section_offset_map_ != NULL)
5553 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5554
5555 *psection_offset_map = this->section_offset_map_;
5556 this->section_offset_map_ = NULL;
5557 this->last_input_section_ = exidx_input_section;
5558
5559 // Set the first output text section so that we can link the EXIDX output
5560 // section to it. Ignore any EXIDX input section that is completely merged.
5561 if (this->first_output_text_section_ == NULL
5562 && deleted_bytes != section_size)
5563 {
5564 unsigned int link = exidx_input_section->link();
5565 Output_section* os = relobj->output_section(link);
5566 gold_assert(os != NULL);
5567 this->first_output_text_section_ = os;
5568 }
5569
5570 return deleted_bytes;
5571 }
5572
5573 // Arm_output_section methods.
5574
5575 // Create a stub group for input sections from BEGIN to END. OWNER
5576 // points to the input section to be the owner a new stub table.
5577
5578 template<bool big_endian>
5579 void
5580 Arm_output_section<big_endian>::create_stub_group(
5581 Input_section_list::const_iterator begin,
5582 Input_section_list::const_iterator end,
5583 Input_section_list::const_iterator owner,
5584 Target_arm<big_endian>* target,
5585 std::vector<Output_relaxed_input_section*>* new_relaxed_sections,
5586 const Task* task)
5587 {
5588 // We use a different kind of relaxed section in an EXIDX section.
5589 // The static casting from Output_relaxed_input_section to
5590 // Arm_input_section is invalid in an EXIDX section. We are okay
5591 // because we should not be calling this for an EXIDX section.
5592 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5593
5594 // Currently we convert ordinary input sections into relaxed sections only
5595 // at this point but we may want to support creating relaxed input section
5596 // very early. So we check here to see if owner is already a relaxed
5597 // section.
5598
5599 Arm_input_section<big_endian>* arm_input_section;
5600 if (owner->is_relaxed_input_section())
5601 {
5602 arm_input_section =
5603 Arm_input_section<big_endian>::as_arm_input_section(
5604 owner->relaxed_input_section());
5605 }
5606 else
5607 {
5608 gold_assert(owner->is_input_section());
5609 // Create a new relaxed input section. We need to lock the original
5610 // file.
5611 Task_lock_obj<Object> tl(task, owner->relobj());
5612 arm_input_section =
5613 target->new_arm_input_section(owner->relobj(), owner->shndx());
5614 new_relaxed_sections->push_back(arm_input_section);
5615 }
5616
5617 // Create a stub table.
5618 Stub_table<big_endian>* stub_table =
5619 target->new_stub_table(arm_input_section);
5620
5621 arm_input_section->set_stub_table(stub_table);
5622
5623 Input_section_list::const_iterator p = begin;
5624 Input_section_list::const_iterator prev_p;
5625
5626 // Look for input sections or relaxed input sections in [begin ... end].
5627 do
5628 {
5629 if (p->is_input_section() || p->is_relaxed_input_section())
5630 {
5631 // The stub table information for input sections live
5632 // in their objects.
5633 Arm_relobj<big_endian>* arm_relobj =
5634 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5635 arm_relobj->set_stub_table(p->shndx(), stub_table);
5636 }
5637 prev_p = p++;
5638 }
5639 while (prev_p != end);
5640 }
5641
5642 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5643 // of stub groups. We grow a stub group by adding input section until the
5644 // size is just below GROUP_SIZE. The last input section will be converted
5645 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5646 // input section after the stub table, effectively double the group size.
5647 //
5648 // This is similar to the group_sections() function in elf32-arm.c but is
5649 // implemented differently.
5650
5651 template<bool big_endian>
5652 void
5653 Arm_output_section<big_endian>::group_sections(
5654 section_size_type group_size,
5655 bool stubs_always_after_branch,
5656 Target_arm<big_endian>* target,
5657 const Task* task)
5658 {
5659 // States for grouping.
5660 typedef enum
5661 {
5662 // No group is being built.
5663 NO_GROUP,
5664 // A group is being built but the stub table is not found yet.
5665 // We keep group a stub group until the size is just under GROUP_SIZE.
5666 // The last input section in the group will be used as the stub table.
5667 FINDING_STUB_SECTION,
5668 // A group is being built and we have already found a stub table.
5669 // We enter this state to grow a stub group by adding input section
5670 // after the stub table. This effectively doubles the group size.
5671 HAS_STUB_SECTION
5672 } State;
5673
5674 // Any newly created relaxed sections are stored here.
5675 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5676
5677 State state = NO_GROUP;
5678 section_size_type off = 0;
5679 section_size_type group_begin_offset = 0;
5680 section_size_type group_end_offset = 0;
5681 section_size_type stub_table_end_offset = 0;
5682 Input_section_list::const_iterator group_begin =
5683 this->input_sections().end();
5684 Input_section_list::const_iterator stub_table =
5685 this->input_sections().end();
5686 Input_section_list::const_iterator group_end = this->input_sections().end();
5687 for (Input_section_list::const_iterator p = this->input_sections().begin();
5688 p != this->input_sections().end();
5689 ++p)
5690 {
5691 section_size_type section_begin_offset =
5692 align_address(off, p->addralign());
5693 section_size_type section_end_offset =
5694 section_begin_offset + p->data_size();
5695
5696 // Check to see if we should group the previously seen sections.
5697 switch (state)
5698 {
5699 case NO_GROUP:
5700 break;
5701
5702 case FINDING_STUB_SECTION:
5703 // Adding this section makes the group larger than GROUP_SIZE.
5704 if (section_end_offset - group_begin_offset >= group_size)
5705 {
5706 if (stubs_always_after_branch)
5707 {
5708 gold_assert(group_end != this->input_sections().end());
5709 this->create_stub_group(group_begin, group_end, group_end,
5710 target, &new_relaxed_sections,
5711 task);
5712 state = NO_GROUP;
5713 }
5714 else
5715 {
5716 // But wait, there's more! Input sections up to
5717 // stub_group_size bytes after the stub table can be
5718 // handled by it too.
5719 state = HAS_STUB_SECTION;
5720 stub_table = group_end;
5721 stub_table_end_offset = group_end_offset;
5722 }
5723 }
5724 break;
5725
5726 case HAS_STUB_SECTION:
5727 // Adding this section makes the post stub-section group larger
5728 // than GROUP_SIZE.
5729 if (section_end_offset - stub_table_end_offset >= group_size)
5730 {
5731 gold_assert(group_end != this->input_sections().end());
5732 this->create_stub_group(group_begin, group_end, stub_table,
5733 target, &new_relaxed_sections, task);
5734 state = NO_GROUP;
5735 }
5736 break;
5737
5738 default:
5739 gold_unreachable();
5740 }
5741
5742 // If we see an input section and currently there is no group, start
5743 // a new one. Skip any empty sections. We look at the data size
5744 // instead of calling p->relobj()->section_size() to avoid locking.
5745 if ((p->is_input_section() || p->is_relaxed_input_section())
5746 && (p->data_size() != 0))
5747 {
5748 if (state == NO_GROUP)
5749 {
5750 state = FINDING_STUB_SECTION;
5751 group_begin = p;
5752 group_begin_offset = section_begin_offset;
5753 }
5754
5755 // Keep track of the last input section seen.
5756 group_end = p;
5757 group_end_offset = section_end_offset;
5758 }
5759
5760 off = section_end_offset;
5761 }
5762
5763 // Create a stub group for any ungrouped sections.
5764 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5765 {
5766 gold_assert(group_end != this->input_sections().end());
5767 this->create_stub_group(group_begin, group_end,
5768 (state == FINDING_STUB_SECTION
5769 ? group_end
5770 : stub_table),
5771 target, &new_relaxed_sections, task);
5772 }
5773
5774 // Convert input section into relaxed input section in a batch.
5775 if (!new_relaxed_sections.empty())
5776 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5777
5778 // Update the section offsets
5779 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5780 {
5781 Arm_relobj<big_endian>* arm_relobj =
5782 Arm_relobj<big_endian>::as_arm_relobj(
5783 new_relaxed_sections[i]->relobj());
5784 unsigned int shndx = new_relaxed_sections[i]->shndx();
5785 // Tell Arm_relobj that this input section is converted.
5786 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5787 }
5788 }
5789
5790 // Append non empty text sections in this to LIST in ascending
5791 // order of their position in this.
5792
5793 template<bool big_endian>
5794 void
5795 Arm_output_section<big_endian>::append_text_sections_to_list(
5796 Text_section_list* list)
5797 {
5798 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5799
5800 for (Input_section_list::const_iterator p = this->input_sections().begin();
5801 p != this->input_sections().end();
5802 ++p)
5803 {
5804 // We only care about plain or relaxed input sections. We also
5805 // ignore any merged sections.
5806 if (p->is_input_section() || p->is_relaxed_input_section())
5807 list->push_back(Text_section_list::value_type(p->relobj(),
5808 p->shndx()));
5809 }
5810 }
5811
5812 template<bool big_endian>
5813 void
5814 Arm_output_section<big_endian>::fix_exidx_coverage(
5815 Layout* layout,
5816 const Text_section_list& sorted_text_sections,
5817 Symbol_table* symtab,
5818 bool merge_exidx_entries,
5819 const Task* task)
5820 {
5821 // We should only do this for the EXIDX output section.
5822 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5823
5824 // We don't want the relaxation loop to undo these changes, so we discard
5825 // the current saved states and take another one after the fix-up.
5826 this->discard_states();
5827
5828 // Remove all input sections.
5829 uint64_t address = this->address();
5830 typedef std::list<Output_section::Input_section> Input_section_list;
5831 Input_section_list input_sections;
5832 this->reset_address_and_file_offset();
5833 this->get_input_sections(address, std::string(""), &input_sections);
5834
5835 if (!this->input_sections().empty())
5836 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5837
5838 // Go through all the known input sections and record them.
5839 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5840 typedef Unordered_map<Section_id, const Output_section::Input_section*,
5841 Section_id_hash> Text_to_exidx_map;
5842 Text_to_exidx_map text_to_exidx_map;
5843 for (Input_section_list::const_iterator p = input_sections.begin();
5844 p != input_sections.end();
5845 ++p)
5846 {
5847 // This should never happen. At this point, we should only see
5848 // plain EXIDX input sections.
5849 gold_assert(!p->is_relaxed_input_section());
5850 text_to_exidx_map[Section_id(p->relobj(), p->shndx())] = &(*p);
5851 }
5852
5853 Arm_exidx_fixup exidx_fixup(this, merge_exidx_entries);
5854
5855 // Go over the sorted text sections.
5856 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5857 Section_id_set processed_input_sections;
5858 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5859 p != sorted_text_sections.end();
5860 ++p)
5861 {
5862 Relobj* relobj = p->first;
5863 unsigned int shndx = p->second;
5864
5865 Arm_relobj<big_endian>* arm_relobj =
5866 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5867 const Arm_exidx_input_section* exidx_input_section =
5868 arm_relobj->exidx_input_section_by_link(shndx);
5869
5870 // If this text section has no EXIDX section or if the EXIDX section
5871 // has errors, force an EXIDX_CANTUNWIND entry pointing to the end
5872 // of the last seen EXIDX section.
5873 if (exidx_input_section == NULL || exidx_input_section->has_errors())
5874 {
5875 exidx_fixup.add_exidx_cantunwind_as_needed();
5876 continue;
5877 }
5878
5879 Relobj* exidx_relobj = exidx_input_section->relobj();
5880 unsigned int exidx_shndx = exidx_input_section->shndx();
5881 Section_id sid(exidx_relobj, exidx_shndx);
5882 Text_to_exidx_map::const_iterator iter = text_to_exidx_map.find(sid);
5883 if (iter == text_to_exidx_map.end())
5884 {
5885 // This is odd. We have not seen this EXIDX input section before.
5886 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5887 // issue a warning instead. We assume the user knows what he
5888 // or she is doing. Otherwise, this is an error.
5889 if (layout->script_options()->saw_sections_clause())
5890 gold_warning(_("unwinding may not work because EXIDX input section"
5891 " %u of %s is not in EXIDX output section"),
5892 exidx_shndx, exidx_relobj->name().c_str());
5893 else
5894 gold_error(_("unwinding may not work because EXIDX input section"
5895 " %u of %s is not in EXIDX output section"),
5896 exidx_shndx, exidx_relobj->name().c_str());
5897
5898 exidx_fixup.add_exidx_cantunwind_as_needed();
5899 continue;
5900 }
5901
5902 // We need to access the contents of the EXIDX section, lock the
5903 // object here.
5904 Task_lock_obj<Object> tl(task, exidx_relobj);
5905 section_size_type exidx_size;
5906 const unsigned char* exidx_contents =
5907 exidx_relobj->section_contents(exidx_shndx, &exidx_size, false);
5908
5909 // Fix up coverage and append input section to output data list.
5910 Arm_exidx_section_offset_map* section_offset_map = NULL;
5911 uint32_t deleted_bytes =
5912 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5913 exidx_contents,
5914 exidx_size,
5915 &section_offset_map);
5916
5917 if (deleted_bytes == exidx_input_section->size())
5918 {
5919 // The whole EXIDX section got merged. Remove it from output.
5920 gold_assert(section_offset_map == NULL);
5921 exidx_relobj->set_output_section(exidx_shndx, NULL);
5922
5923 // All local symbols defined in this input section will be dropped.
5924 // We need to adjust output local symbol count.
5925 arm_relobj->set_output_local_symbol_count_needs_update();
5926 }
5927 else if (deleted_bytes > 0)
5928 {
5929 // Some entries are merged. We need to convert this EXIDX input
5930 // section into a relaxed section.
5931 gold_assert(section_offset_map != NULL);
5932
5933 Arm_exidx_merged_section* merged_section =
5934 new Arm_exidx_merged_section(*exidx_input_section,
5935 *section_offset_map, deleted_bytes);
5936 merged_section->build_contents(exidx_contents, exidx_size);
5937
5938 const std::string secname = exidx_relobj->section_name(exidx_shndx);
5939 this->add_relaxed_input_section(layout, merged_section, secname);
5940 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5941
5942 // All local symbols defined in discarded portions of this input
5943 // section will be dropped. We need to adjust output local symbol
5944 // count.
5945 arm_relobj->set_output_local_symbol_count_needs_update();
5946 }
5947 else
5948 {
5949 // Just add back the EXIDX input section.
5950 gold_assert(section_offset_map == NULL);
5951 const Output_section::Input_section* pis = iter->second;
5952 gold_assert(pis->is_input_section());
5953 this->add_script_input_section(*pis);
5954 }
5955
5956 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5957 }
5958
5959 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5960 exidx_fixup.add_exidx_cantunwind_as_needed();
5961
5962 // Remove any known EXIDX input sections that are not processed.
5963 for (Input_section_list::const_iterator p = input_sections.begin();
5964 p != input_sections.end();
5965 ++p)
5966 {
5967 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5968 == processed_input_sections.end())
5969 {
5970 // We discard a known EXIDX section because its linked
5971 // text section has been folded by ICF. We also discard an
5972 // EXIDX section with error, the output does not matter in this
5973 // case. We do this to avoid triggering asserts.
5974 Arm_relobj<big_endian>* arm_relobj =
5975 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5976 const Arm_exidx_input_section* exidx_input_section =
5977 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5978 gold_assert(exidx_input_section != NULL);
5979 if (!exidx_input_section->has_errors())
5980 {
5981 unsigned int text_shndx = exidx_input_section->link();
5982 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5983 }
5984
5985 // Remove this from link. We also need to recount the
5986 // local symbols.
5987 p->relobj()->set_output_section(p->shndx(), NULL);
5988 arm_relobj->set_output_local_symbol_count_needs_update();
5989 }
5990 }
5991
5992 // Link exidx output section to the first seen output section and
5993 // set correct entry size.
5994 this->set_link_section(exidx_fixup.first_output_text_section());
5995 this->set_entsize(8);
5996
5997 // Make changes permanent.
5998 this->save_states();
5999 this->set_section_offsets_need_adjustment();
6000 }
6001
6002 // Link EXIDX output sections to text output sections.
6003
6004 template<bool big_endian>
6005 void
6006 Arm_output_section<big_endian>::set_exidx_section_link()
6007 {
6008 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
6009 if (!this->input_sections().empty())
6010 {
6011 Input_section_list::const_iterator p = this->input_sections().begin();
6012 Arm_relobj<big_endian>* arm_relobj =
6013 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
6014 unsigned exidx_shndx = p->shndx();
6015 const Arm_exidx_input_section* exidx_input_section =
6016 arm_relobj->exidx_input_section_by_shndx(exidx_shndx);
6017 gold_assert(exidx_input_section != NULL);
6018 unsigned int text_shndx = exidx_input_section->link();
6019 Output_section* os = arm_relobj->output_section(text_shndx);
6020 this->set_link_section(os);
6021 }
6022 }
6023
6024 // Arm_relobj methods.
6025
6026 // Determine if an input section is scannable for stub processing. SHDR is
6027 // the header of the section and SHNDX is the section index. OS is the output
6028 // section for the input section and SYMTAB is the global symbol table used to
6029 // look up ICF information.
6030
6031 template<bool big_endian>
6032 bool
6033 Arm_relobj<big_endian>::section_is_scannable(
6034 const elfcpp::Shdr<32, big_endian>& shdr,
6035 unsigned int shndx,
6036 const Output_section* os,
6037 const Symbol_table* symtab)
6038 {
6039 // Skip any empty sections, unallocated sections or sections whose
6040 // type are not SHT_PROGBITS.
6041 if (shdr.get_sh_size() == 0
6042 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
6043 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
6044 return false;
6045
6046 // Skip any discarded or ICF'ed sections.
6047 if (os == NULL || symtab->is_section_folded(this, shndx))
6048 return false;
6049
6050 // If this requires special offset handling, check to see if it is
6051 // a relaxed section. If this is not, then it is a merged section that
6052 // we cannot handle.
6053 if (this->is_output_section_offset_invalid(shndx))
6054 {
6055 const Output_relaxed_input_section* poris =
6056 os->find_relaxed_input_section(this, shndx);
6057 if (poris == NULL)
6058 return false;
6059 }
6060
6061 return true;
6062 }
6063
6064 // Determine if we want to scan the SHNDX-th section for relocation stubs.
6065 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6066
6067 template<bool big_endian>
6068 bool
6069 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
6070 const elfcpp::Shdr<32, big_endian>& shdr,
6071 const Relobj::Output_sections& out_sections,
6072 const Symbol_table* symtab,
6073 const unsigned char* pshdrs)
6074 {
6075 unsigned int sh_type = shdr.get_sh_type();
6076 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
6077 return false;
6078
6079 // Ignore empty section.
6080 off_t sh_size = shdr.get_sh_size();
6081 if (sh_size == 0)
6082 return false;
6083
6084 // Ignore reloc section with unexpected symbol table. The
6085 // error will be reported in the final link.
6086 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
6087 return false;
6088
6089 unsigned int reloc_size;
6090 if (sh_type == elfcpp::SHT_REL)
6091 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6092 else
6093 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6094
6095 // Ignore reloc section with unexpected entsize or uneven size.
6096 // The error will be reported in the final link.
6097 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
6098 return false;
6099
6100 // Ignore reloc section with bad info. This error will be
6101 // reported in the final link.
6102 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6103 if (index >= this->shnum())
6104 return false;
6105
6106 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6107 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
6108 return this->section_is_scannable(text_shdr, index,
6109 out_sections[index], symtab);
6110 }
6111
6112 // Return the output address of either a plain input section or a relaxed
6113 // input section. SHNDX is the section index. We define and use this
6114 // instead of calling Output_section::output_address because that is slow
6115 // for large output.
6116
6117 template<bool big_endian>
6118 Arm_address
6119 Arm_relobj<big_endian>::simple_input_section_output_address(
6120 unsigned int shndx,
6121 Output_section* os)
6122 {
6123 if (this->is_output_section_offset_invalid(shndx))
6124 {
6125 const Output_relaxed_input_section* poris =
6126 os->find_relaxed_input_section(this, shndx);
6127 // We do not handle merged sections here.
6128 gold_assert(poris != NULL);
6129 return poris->address();
6130 }
6131 else
6132 return os->address() + this->get_output_section_offset(shndx);
6133 }
6134
6135 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
6136 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
6137
6138 template<bool big_endian>
6139 bool
6140 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
6141 const elfcpp::Shdr<32, big_endian>& shdr,
6142 unsigned int shndx,
6143 Output_section* os,
6144 const Symbol_table* symtab)
6145 {
6146 if (!this->section_is_scannable(shdr, shndx, os, symtab))
6147 return false;
6148
6149 // If the section does not cross any 4K-boundaries, it does not need to
6150 // be scanned.
6151 Arm_address address = this->simple_input_section_output_address(shndx, os);
6152 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
6153 return false;
6154
6155 return true;
6156 }
6157
6158 // Scan a section for Cortex-A8 workaround.
6159
6160 template<bool big_endian>
6161 void
6162 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
6163 const elfcpp::Shdr<32, big_endian>& shdr,
6164 unsigned int shndx,
6165 Output_section* os,
6166 Target_arm<big_endian>* arm_target)
6167 {
6168 // Look for the first mapping symbol in this section. It should be
6169 // at (shndx, 0).
6170 Mapping_symbol_position section_start(shndx, 0);
6171 typename Mapping_symbols_info::const_iterator p =
6172 this->mapping_symbols_info_.lower_bound(section_start);
6173
6174 // There are no mapping symbols for this section. Treat it as a data-only
6175 // section. Issue a warning if section is marked as containing
6176 // instructions.
6177 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
6178 {
6179 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
6180 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
6181 "erratum because it has no mapping symbols."),
6182 shndx, this->name().c_str());
6183 return;
6184 }
6185
6186 Arm_address output_address =
6187 this->simple_input_section_output_address(shndx, os);
6188
6189 // Get the section contents.
6190 section_size_type input_view_size = 0;
6191 const unsigned char* input_view =
6192 this->section_contents(shndx, &input_view_size, false);
6193
6194 // We need to go through the mapping symbols to determine what to
6195 // scan. There are two reasons. First, we should look at THUMB code and
6196 // THUMB code only. Second, we only want to look at the 4K-page boundary
6197 // to speed up the scanning.
6198
6199 while (p != this->mapping_symbols_info_.end()
6200 && p->first.first == shndx)
6201 {
6202 typename Mapping_symbols_info::const_iterator next =
6203 this->mapping_symbols_info_.upper_bound(p->first);
6204
6205 // Only scan part of a section with THUMB code.
6206 if (p->second == 't')
6207 {
6208 // Determine the end of this range.
6209 section_size_type span_start =
6210 convert_to_section_size_type(p->first.second);
6211 section_size_type span_end;
6212 if (next != this->mapping_symbols_info_.end()
6213 && next->first.first == shndx)
6214 span_end = convert_to_section_size_type(next->first.second);
6215 else
6216 span_end = convert_to_section_size_type(shdr.get_sh_size());
6217
6218 if (((span_start + output_address) & ~0xfffUL)
6219 != ((span_end + output_address - 1) & ~0xfffUL))
6220 {
6221 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
6222 span_start, span_end,
6223 input_view,
6224 output_address);
6225 }
6226 }
6227
6228 p = next;
6229 }
6230 }
6231
6232 // Scan relocations for stub generation.
6233
6234 template<bool big_endian>
6235 void
6236 Arm_relobj<big_endian>::scan_sections_for_stubs(
6237 Target_arm<big_endian>* arm_target,
6238 const Symbol_table* symtab,
6239 const Layout* layout)
6240 {
6241 unsigned int shnum = this->shnum();
6242 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6243
6244 // Read the section headers.
6245 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6246 shnum * shdr_size,
6247 true, true);
6248
6249 // To speed up processing, we set up hash tables for fast lookup of
6250 // input offsets to output addresses.
6251 this->initialize_input_to_output_maps();
6252
6253 const Relobj::Output_sections& out_sections(this->output_sections());
6254
6255 Relocate_info<32, big_endian> relinfo;
6256 relinfo.symtab = symtab;
6257 relinfo.layout = layout;
6258 relinfo.object = this;
6259
6260 // Do relocation stubs scanning.
6261 const unsigned char* p = pshdrs + shdr_size;
6262 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6263 {
6264 const elfcpp::Shdr<32, big_endian> shdr(p);
6265 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
6266 pshdrs))
6267 {
6268 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
6269 Arm_address output_offset = this->get_output_section_offset(index);
6270 Arm_address output_address;
6271 if (output_offset != invalid_address)
6272 output_address = out_sections[index]->address() + output_offset;
6273 else
6274 {
6275 // Currently this only happens for a relaxed section.
6276 const Output_relaxed_input_section* poris =
6277 out_sections[index]->find_relaxed_input_section(this, index);
6278 gold_assert(poris != NULL);
6279 output_address = poris->address();
6280 }
6281
6282 // Get the relocations.
6283 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
6284 shdr.get_sh_size(),
6285 true, false);
6286
6287 // Get the section contents. This does work for the case in which
6288 // we modify the contents of an input section. We need to pass the
6289 // output view under such circumstances.
6290 section_size_type input_view_size = 0;
6291 const unsigned char* input_view =
6292 this->section_contents(index, &input_view_size, false);
6293
6294 relinfo.reloc_shndx = i;
6295 relinfo.data_shndx = index;
6296 unsigned int sh_type = shdr.get_sh_type();
6297 unsigned int reloc_size;
6298 if (sh_type == elfcpp::SHT_REL)
6299 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6300 else
6301 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6302
6303 Output_section* os = out_sections[index];
6304 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
6305 shdr.get_sh_size() / reloc_size,
6306 os,
6307 output_offset == invalid_address,
6308 input_view, output_address,
6309 input_view_size);
6310 }
6311 }
6312
6313 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6314 // after its relocation section, if there is one, is processed for
6315 // relocation stubs. Merging this loop with the one above would have been
6316 // complicated since we would have had to make sure that relocation stub
6317 // scanning is done first.
6318 if (arm_target->fix_cortex_a8())
6319 {
6320 const unsigned char* p = pshdrs + shdr_size;
6321 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6322 {
6323 const elfcpp::Shdr<32, big_endian> shdr(p);
6324 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6325 out_sections[i],
6326 symtab))
6327 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6328 arm_target);
6329 }
6330 }
6331
6332 // After we've done the relocations, we release the hash tables,
6333 // since we no longer need them.
6334 this->free_input_to_output_maps();
6335 }
6336
6337 // Count the local symbols. The ARM backend needs to know if a symbol
6338 // is a THUMB function or not. For global symbols, it is easy because
6339 // the Symbol object keeps the ELF symbol type. For local symbol it is
6340 // harder because we cannot access this information. So we override the
6341 // do_count_local_symbol in parent and scan local symbols to mark
6342 // THUMB functions. This is not the most efficient way but I do not want to
6343 // slow down other ports by calling a per symbol target hook inside
6344 // Sized_relobj_file<size, big_endian>::do_count_local_symbols.
6345
6346 template<bool big_endian>
6347 void
6348 Arm_relobj<big_endian>::do_count_local_symbols(
6349 Stringpool_template<char>* pool,
6350 Stringpool_template<char>* dynpool)
6351 {
6352 // We need to fix-up the values of any local symbols whose type are
6353 // STT_ARM_TFUNC.
6354
6355 // Ask parent to count the local symbols.
6356 Sized_relobj_file<32, big_endian>::do_count_local_symbols(pool, dynpool);
6357 const unsigned int loccount = this->local_symbol_count();
6358 if (loccount == 0)
6359 return;
6360
6361 // Initialize the thumb function bit-vector.
6362 std::vector<bool> empty_vector(loccount, false);
6363 this->local_symbol_is_thumb_function_.swap(empty_vector);
6364
6365 // Read the symbol table section header.
6366 const unsigned int symtab_shndx = this->symtab_shndx();
6367 elfcpp::Shdr<32, big_endian>
6368 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6369 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6370
6371 // Read the local symbols.
6372 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6373 gold_assert(loccount == symtabshdr.get_sh_info());
6374 off_t locsize = loccount * sym_size;
6375 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6376 locsize, true, true);
6377
6378 // For mapping symbol processing, we need to read the symbol names.
6379 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6380 if (strtab_shndx >= this->shnum())
6381 {
6382 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6383 return;
6384 }
6385
6386 elfcpp::Shdr<32, big_endian>
6387 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6388 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6389 {
6390 this->error(_("symbol table name section has wrong type: %u"),
6391 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6392 return;
6393 }
6394 const char* pnames =
6395 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6396 strtabshdr.get_sh_size(),
6397 false, false));
6398
6399 // Loop over the local symbols and mark any local symbols pointing
6400 // to THUMB functions.
6401
6402 // Skip the first dummy symbol.
6403 psyms += sym_size;
6404 typename Sized_relobj_file<32, big_endian>::Local_values* plocal_values =
6405 this->local_values();
6406 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6407 {
6408 elfcpp::Sym<32, big_endian> sym(psyms);
6409 elfcpp::STT st_type = sym.get_st_type();
6410 Symbol_value<32>& lv((*plocal_values)[i]);
6411 Arm_address input_value = lv.input_value();
6412
6413 // Check to see if this is a mapping symbol.
6414 const char* sym_name = pnames + sym.get_st_name();
6415 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6416 {
6417 bool is_ordinary;
6418 unsigned int input_shndx =
6419 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6420 gold_assert(is_ordinary);
6421
6422 // Strip of LSB in case this is a THUMB symbol.
6423 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6424 this->mapping_symbols_info_[msp] = sym_name[1];
6425 }
6426
6427 if (st_type == elfcpp::STT_ARM_TFUNC
6428 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6429 {
6430 // This is a THUMB function. Mark this and canonicalize the
6431 // symbol value by setting LSB.
6432 this->local_symbol_is_thumb_function_[i] = true;
6433 if ((input_value & 1) == 0)
6434 lv.set_input_value(input_value | 1);
6435 }
6436 }
6437 }
6438
6439 // Relocate sections.
6440 template<bool big_endian>
6441 void
6442 Arm_relobj<big_endian>::do_relocate_sections(
6443 const Symbol_table* symtab,
6444 const Layout* layout,
6445 const unsigned char* pshdrs,
6446 Output_file* of,
6447 typename Sized_relobj_file<32, big_endian>::Views* pviews)
6448 {
6449 // Call parent to relocate sections.
6450 Sized_relobj_file<32, big_endian>::do_relocate_sections(symtab, layout,
6451 pshdrs, of, pviews);
6452
6453 // We do not generate stubs if doing a relocatable link.
6454 if (parameters->options().relocatable())
6455 return;
6456
6457 // Relocate stub tables.
6458 unsigned int shnum = this->shnum();
6459
6460 Target_arm<big_endian>* arm_target =
6461 Target_arm<big_endian>::default_target();
6462
6463 Relocate_info<32, big_endian> relinfo;
6464 relinfo.symtab = symtab;
6465 relinfo.layout = layout;
6466 relinfo.object = this;
6467
6468 for (unsigned int i = 1; i < shnum; ++i)
6469 {
6470 Arm_input_section<big_endian>* arm_input_section =
6471 arm_target->find_arm_input_section(this, i);
6472
6473 if (arm_input_section != NULL
6474 && arm_input_section->is_stub_table_owner()
6475 && !arm_input_section->stub_table()->empty())
6476 {
6477 // We cannot discard a section if it owns a stub table.
6478 Output_section* os = this->output_section(i);
6479 gold_assert(os != NULL);
6480
6481 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6482 relinfo.reloc_shdr = NULL;
6483 relinfo.data_shndx = i;
6484 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6485
6486 gold_assert((*pviews)[i].view != NULL);
6487
6488 // We are passed the output section view. Adjust it to cover the
6489 // stub table only.
6490 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6491 gold_assert((stub_table->address() >= (*pviews)[i].address)
6492 && ((stub_table->address() + stub_table->data_size())
6493 <= (*pviews)[i].address + (*pviews)[i].view_size));
6494
6495 off_t offset = stub_table->address() - (*pviews)[i].address;
6496 unsigned char* view = (*pviews)[i].view + offset;
6497 Arm_address address = stub_table->address();
6498 section_size_type view_size = stub_table->data_size();
6499
6500 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6501 view_size);
6502 }
6503
6504 // Apply Cortex A8 workaround if applicable.
6505 if (this->section_has_cortex_a8_workaround(i))
6506 {
6507 unsigned char* view = (*pviews)[i].view;
6508 Arm_address view_address = (*pviews)[i].address;
6509 section_size_type view_size = (*pviews)[i].view_size;
6510 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6511
6512 // Adjust view to cover section.
6513 Output_section* os = this->output_section(i);
6514 gold_assert(os != NULL);
6515 Arm_address section_address =
6516 this->simple_input_section_output_address(i, os);
6517 uint64_t section_size = this->section_size(i);
6518
6519 gold_assert(section_address >= view_address
6520 && ((section_address + section_size)
6521 <= (view_address + view_size)));
6522
6523 unsigned char* section_view = view + (section_address - view_address);
6524
6525 // Apply the Cortex-A8 workaround to the output address range
6526 // corresponding to this input section.
6527 stub_table->apply_cortex_a8_workaround_to_address_range(
6528 arm_target,
6529 section_view,
6530 section_address,
6531 section_size);
6532 }
6533 }
6534 }
6535
6536 // Find the linked text section of an EXIDX section by looking at the first
6537 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6538 // must be linked to its associated code section via the sh_link field of
6539 // its section header. However, some tools are broken and the link is not
6540 // always set. LD just drops such an EXIDX section silently, causing the
6541 // associated code not unwindabled. Here we try a little bit harder to
6542 // discover the linked code section.
6543 //
6544 // PSHDR points to the section header of a relocation section of an EXIDX
6545 // section. If we can find a linked text section, return true and
6546 // store the text section index in the location PSHNDX. Otherwise
6547 // return false.
6548
6549 template<bool big_endian>
6550 bool
6551 Arm_relobj<big_endian>::find_linked_text_section(
6552 const unsigned char* pshdr,
6553 const unsigned char* psyms,
6554 unsigned int* pshndx)
6555 {
6556 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6557
6558 // If there is no relocation, we cannot find the linked text section.
6559 size_t reloc_size;
6560 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6561 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6562 else
6563 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6564 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6565
6566 // Get the relocations.
6567 const unsigned char* prelocs =
6568 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6569
6570 // Find the REL31 relocation for the first word of the first EXIDX entry.
6571 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6572 {
6573 Arm_address r_offset;
6574 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6575 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6576 {
6577 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6578 r_info = reloc.get_r_info();
6579 r_offset = reloc.get_r_offset();
6580 }
6581 else
6582 {
6583 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6584 r_info = reloc.get_r_info();
6585 r_offset = reloc.get_r_offset();
6586 }
6587
6588 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6589 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6590 continue;
6591
6592 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6593 if (r_sym == 0
6594 || r_sym >= this->local_symbol_count()
6595 || r_offset != 0)
6596 continue;
6597
6598 // This is the relocation for the first word of the first EXIDX entry.
6599 // We expect to see a local section symbol.
6600 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6601 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6602 if (sym.get_st_type() == elfcpp::STT_SECTION)
6603 {
6604 bool is_ordinary;
6605 *pshndx =
6606 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6607 gold_assert(is_ordinary);
6608 return true;
6609 }
6610 else
6611 return false;
6612 }
6613
6614 return false;
6615 }
6616
6617 // Make an EXIDX input section object for an EXIDX section whose index is
6618 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6619 // is the section index of the linked text section.
6620
6621 template<bool big_endian>
6622 void
6623 Arm_relobj<big_endian>::make_exidx_input_section(
6624 unsigned int shndx,
6625 const elfcpp::Shdr<32, big_endian>& shdr,
6626 unsigned int text_shndx,
6627 const elfcpp::Shdr<32, big_endian>& text_shdr)
6628 {
6629 // Create an Arm_exidx_input_section object for this EXIDX section.
6630 Arm_exidx_input_section* exidx_input_section =
6631 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6632 shdr.get_sh_addralign(),
6633 text_shdr.get_sh_size());
6634
6635 gold_assert(this->exidx_section_map_[shndx] == NULL);
6636 this->exidx_section_map_[shndx] = exidx_input_section;
6637
6638 if (text_shndx == elfcpp::SHN_UNDEF || text_shndx >= this->shnum())
6639 {
6640 gold_error(_("EXIDX section %s(%u) links to invalid section %u in %s"),
6641 this->section_name(shndx).c_str(), shndx, text_shndx,
6642 this->name().c_str());
6643 exidx_input_section->set_has_errors();
6644 }
6645 else if (this->exidx_section_map_[text_shndx] != NULL)
6646 {
6647 unsigned other_exidx_shndx =
6648 this->exidx_section_map_[text_shndx]->shndx();
6649 gold_error(_("EXIDX sections %s(%u) and %s(%u) both link to text section"
6650 "%s(%u) in %s"),
6651 this->section_name(shndx).c_str(), shndx,
6652 this->section_name(other_exidx_shndx).c_str(),
6653 other_exidx_shndx, this->section_name(text_shndx).c_str(),
6654 text_shndx, this->name().c_str());
6655 exidx_input_section->set_has_errors();
6656 }
6657 else
6658 this->exidx_section_map_[text_shndx] = exidx_input_section;
6659
6660 // Check section flags of text section.
6661 if ((text_shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0)
6662 {
6663 gold_error(_("EXIDX section %s(%u) links to non-allocated section %s(%u) "
6664 " in %s"),
6665 this->section_name(shndx).c_str(), shndx,
6666 this->section_name(text_shndx).c_str(), text_shndx,
6667 this->name().c_str());
6668 exidx_input_section->set_has_errors();
6669 }
6670 else if ((text_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) == 0)
6671 // I would like to make this an error but currently ld just ignores
6672 // this.
6673 gold_warning(_("EXIDX section %s(%u) links to non-executable section "
6674 "%s(%u) in %s"),
6675 this->section_name(shndx).c_str(), shndx,
6676 this->section_name(text_shndx).c_str(), text_shndx,
6677 this->name().c_str());
6678 }
6679
6680 // Read the symbol information.
6681
6682 template<bool big_endian>
6683 void
6684 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6685 {
6686 // Call parent class to read symbol information.
6687 Sized_relobj_file<32, big_endian>::do_read_symbols(sd);
6688
6689 // If this input file is a binary file, it has no processor
6690 // specific flags and attributes section.
6691 Input_file::Format format = this->input_file()->format();
6692 if (format != Input_file::FORMAT_ELF)
6693 {
6694 gold_assert(format == Input_file::FORMAT_BINARY);
6695 this->merge_flags_and_attributes_ = false;
6696 return;
6697 }
6698
6699 // Read processor-specific flags in ELF file header.
6700 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6701 elfcpp::Elf_sizes<32>::ehdr_size,
6702 true, false);
6703 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6704 this->processor_specific_flags_ = ehdr.get_e_flags();
6705
6706 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6707 // sections.
6708 std::vector<unsigned int> deferred_exidx_sections;
6709 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6710 const unsigned char* pshdrs = sd->section_headers->data();
6711 const unsigned char* ps = pshdrs + shdr_size;
6712 bool must_merge_flags_and_attributes = false;
6713 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6714 {
6715 elfcpp::Shdr<32, big_endian> shdr(ps);
6716
6717 // Sometimes an object has no contents except the section name string
6718 // table and an empty symbol table with the undefined symbol. We
6719 // don't want to merge processor-specific flags from such an object.
6720 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6721 {
6722 // Symbol table is not empty.
6723 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6724 elfcpp::Elf_sizes<32>::sym_size;
6725 if (shdr.get_sh_size() > sym_size)
6726 must_merge_flags_and_attributes = true;
6727 }
6728 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6729 // If this is neither an empty symbol table nor a string table,
6730 // be conservative.
6731 must_merge_flags_and_attributes = true;
6732
6733 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6734 {
6735 gold_assert(this->attributes_section_data_ == NULL);
6736 section_offset_type section_offset = shdr.get_sh_offset();
6737 section_size_type section_size =
6738 convert_to_section_size_type(shdr.get_sh_size());
6739 const unsigned char* view =
6740 this->get_view(section_offset, section_size, true, false);
6741 this->attributes_section_data_ =
6742 new Attributes_section_data(view, section_size);
6743 }
6744 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6745 {
6746 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6747 if (text_shndx == elfcpp::SHN_UNDEF)
6748 deferred_exidx_sections.push_back(i);
6749 else
6750 {
6751 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6752 + text_shndx * shdr_size);
6753 this->make_exidx_input_section(i, shdr, text_shndx, text_shdr);
6754 }
6755 // EHABI 4.4.1 requires that SHF_LINK_ORDER flag to be set.
6756 if ((shdr.get_sh_flags() & elfcpp::SHF_LINK_ORDER) == 0)
6757 gold_warning(_("SHF_LINK_ORDER not set in EXIDX section %s of %s"),
6758 this->section_name(i).c_str(), this->name().c_str());
6759 }
6760 }
6761
6762 // This is rare.
6763 if (!must_merge_flags_and_attributes)
6764 {
6765 gold_assert(deferred_exidx_sections.empty());
6766 this->merge_flags_and_attributes_ = false;
6767 return;
6768 }
6769
6770 // Some tools are broken and they do not set the link of EXIDX sections.
6771 // We look at the first relocation to figure out the linked sections.
6772 if (!deferred_exidx_sections.empty())
6773 {
6774 // We need to go over the section headers again to find the mapping
6775 // from sections being relocated to their relocation sections. This is
6776 // a bit inefficient as we could do that in the loop above. However,
6777 // we do not expect any deferred EXIDX sections normally. So we do not
6778 // want to slow down the most common path.
6779 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6780 Reloc_map reloc_map;
6781 ps = pshdrs + shdr_size;
6782 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6783 {
6784 elfcpp::Shdr<32, big_endian> shdr(ps);
6785 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6786 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6787 {
6788 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6789 if (info_shndx >= this->shnum())
6790 gold_error(_("relocation section %u has invalid info %u"),
6791 i, info_shndx);
6792 Reloc_map::value_type value(info_shndx, i);
6793 std::pair<Reloc_map::iterator, bool> result =
6794 reloc_map.insert(value);
6795 if (!result.second)
6796 gold_error(_("section %u has multiple relocation sections "
6797 "%u and %u"),
6798 info_shndx, i, reloc_map[info_shndx]);
6799 }
6800 }
6801
6802 // Read the symbol table section header.
6803 const unsigned int symtab_shndx = this->symtab_shndx();
6804 elfcpp::Shdr<32, big_endian>
6805 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6806 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6807
6808 // Read the local symbols.
6809 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6810 const unsigned int loccount = this->local_symbol_count();
6811 gold_assert(loccount == symtabshdr.get_sh_info());
6812 off_t locsize = loccount * sym_size;
6813 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6814 locsize, true, true);
6815
6816 // Process the deferred EXIDX sections.
6817 for (unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6818 {
6819 unsigned int shndx = deferred_exidx_sections[i];
6820 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6821 unsigned int text_shndx = elfcpp::SHN_UNDEF;
6822 Reloc_map::const_iterator it = reloc_map.find(shndx);
6823 if (it != reloc_map.end())
6824 find_linked_text_section(pshdrs + it->second * shdr_size,
6825 psyms, &text_shndx);
6826 elfcpp::Shdr<32, big_endian> text_shdr(pshdrs
6827 + text_shndx * shdr_size);
6828 this->make_exidx_input_section(shndx, shdr, text_shndx, text_shdr);
6829 }
6830 }
6831 }
6832
6833 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6834 // sections for unwinding. These sections are referenced implicitly by
6835 // text sections linked in the section headers. If we ignore these implicit
6836 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6837 // will be garbage-collected incorrectly. Hence we override the same function
6838 // in the base class to handle these implicit references.
6839
6840 template<bool big_endian>
6841 void
6842 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6843 Layout* layout,
6844 Read_relocs_data* rd)
6845 {
6846 // First, call base class method to process relocations in this object.
6847 Sized_relobj_file<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6848
6849 // If --gc-sections is not specified, there is nothing more to do.
6850 // This happens when --icf is used but --gc-sections is not.
6851 if (!parameters->options().gc_sections())
6852 return;
6853
6854 unsigned int shnum = this->shnum();
6855 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6856 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6857 shnum * shdr_size,
6858 true, true);
6859
6860 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6861 // to these from the linked text sections.
6862 const unsigned char* ps = pshdrs + shdr_size;
6863 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6864 {
6865 elfcpp::Shdr<32, big_endian> shdr(ps);
6866 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6867 {
6868 // Found an .ARM.exidx section, add it to the set of reachable
6869 // sections from its linked text section.
6870 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6871 symtab->gc()->add_reference(this, text_shndx, this, i);
6872 }
6873 }
6874 }
6875
6876 // Update output local symbol count. Owing to EXIDX entry merging, some local
6877 // symbols will be removed in output. Adjust output local symbol count
6878 // accordingly. We can only changed the static output local symbol count. It
6879 // is too late to change the dynamic symbols.
6880
6881 template<bool big_endian>
6882 void
6883 Arm_relobj<big_endian>::update_output_local_symbol_count()
6884 {
6885 // Caller should check that this needs updating. We want caller checking
6886 // because output_local_symbol_count_needs_update() is most likely inlined.
6887 gold_assert(this->output_local_symbol_count_needs_update_);
6888
6889 gold_assert(this->symtab_shndx() != -1U);
6890 if (this->symtab_shndx() == 0)
6891 {
6892 // This object has no symbols. Weird but legal.
6893 return;
6894 }
6895
6896 // Read the symbol table section header.
6897 const unsigned int symtab_shndx = this->symtab_shndx();
6898 elfcpp::Shdr<32, big_endian>
6899 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6900 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6901
6902 // Read the local symbols.
6903 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6904 const unsigned int loccount = this->local_symbol_count();
6905 gold_assert(loccount == symtabshdr.get_sh_info());
6906 off_t locsize = loccount * sym_size;
6907 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6908 locsize, true, true);
6909
6910 // Loop over the local symbols.
6911
6912 typedef typename Sized_relobj_file<32, big_endian>::Output_sections
6913 Output_sections;
6914 const Output_sections& out_sections(this->output_sections());
6915 unsigned int shnum = this->shnum();
6916 unsigned int count = 0;
6917 // Skip the first, dummy, symbol.
6918 psyms += sym_size;
6919 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6920 {
6921 elfcpp::Sym<32, big_endian> sym(psyms);
6922
6923 Symbol_value<32>& lv((*this->local_values())[i]);
6924
6925 // This local symbol was already discarded by do_count_local_symbols.
6926 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6927 continue;
6928
6929 bool is_ordinary;
6930 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6931 &is_ordinary);
6932
6933 if (shndx < shnum)
6934 {
6935 Output_section* os = out_sections[shndx];
6936
6937 // This local symbol no longer has an output section. Discard it.
6938 if (os == NULL)
6939 {
6940 lv.set_no_output_symtab_entry();
6941 continue;
6942 }
6943
6944 // Currently we only discard parts of EXIDX input sections.
6945 // We explicitly check for a merged EXIDX input section to avoid
6946 // calling Output_section_data::output_offset unless necessary.
6947 if ((this->get_output_section_offset(shndx) == invalid_address)
6948 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6949 {
6950 section_offset_type output_offset =
6951 os->output_offset(this, shndx, lv.input_value());
6952 if (output_offset == -1)
6953 {
6954 // This symbol is defined in a part of an EXIDX input section
6955 // that is discarded due to entry merging.
6956 lv.set_no_output_symtab_entry();
6957 continue;
6958 }
6959 }
6960 }
6961
6962 ++count;
6963 }
6964
6965 this->set_output_local_symbol_count(count);
6966 this->output_local_symbol_count_needs_update_ = false;
6967 }
6968
6969 // Arm_dynobj methods.
6970
6971 // Read the symbol information.
6972
6973 template<bool big_endian>
6974 void
6975 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6976 {
6977 // Call parent class to read symbol information.
6978 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6979
6980 // Read processor-specific flags in ELF file header.
6981 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6982 elfcpp::Elf_sizes<32>::ehdr_size,
6983 true, false);
6984 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6985 this->processor_specific_flags_ = ehdr.get_e_flags();
6986
6987 // Read the attributes section if there is one.
6988 // We read from the end because gas seems to put it near the end of
6989 // the section headers.
6990 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6991 const unsigned char* ps =
6992 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6993 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6994 {
6995 elfcpp::Shdr<32, big_endian> shdr(ps);
6996 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6997 {
6998 section_offset_type section_offset = shdr.get_sh_offset();
6999 section_size_type section_size =
7000 convert_to_section_size_type(shdr.get_sh_size());
7001 const unsigned char* view =
7002 this->get_view(section_offset, section_size, true, false);
7003 this->attributes_section_data_ =
7004 new Attributes_section_data(view, section_size);
7005 break;
7006 }
7007 }
7008 }
7009
7010 // Stub_addend_reader methods.
7011
7012 // Read the addend of a REL relocation of type R_TYPE at VIEW.
7013
7014 template<bool big_endian>
7015 elfcpp::Elf_types<32>::Elf_Swxword
7016 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
7017 unsigned int r_type,
7018 const unsigned char* view,
7019 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
7020 {
7021 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
7022
7023 switch (r_type)
7024 {
7025 case elfcpp::R_ARM_CALL:
7026 case elfcpp::R_ARM_JUMP24:
7027 case elfcpp::R_ARM_PLT32:
7028 {
7029 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7030 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7031 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
7032 return Bits<26>::sign_extend32(val << 2);
7033 }
7034
7035 case elfcpp::R_ARM_THM_CALL:
7036 case elfcpp::R_ARM_THM_JUMP24:
7037 case elfcpp::R_ARM_THM_XPC22:
7038 {
7039 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7040 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7041 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7042 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7043 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
7044 }
7045
7046 case elfcpp::R_ARM_THM_JUMP19:
7047 {
7048 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
7049 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
7050 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
7051 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
7052 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
7053 }
7054
7055 default:
7056 gold_unreachable();
7057 }
7058 }
7059
7060 // Arm_output_data_got methods.
7061
7062 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
7063 // The first one is initialized to be 1, which is the module index for
7064 // the main executable and the second one 0. A reloc of the type
7065 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
7066 // be applied by gold. GSYM is a global symbol.
7067 //
7068 template<bool big_endian>
7069 void
7070 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7071 unsigned int got_type,
7072 Symbol* gsym)
7073 {
7074 if (gsym->has_got_offset(got_type))
7075 return;
7076
7077 // We are doing a static link. Just mark it as belong to module 1,
7078 // the executable.
7079 unsigned int got_offset = this->add_constant(1);
7080 gsym->set_got_offset(got_type, got_offset);
7081 got_offset = this->add_constant(0);
7082 this->static_relocs_.push_back(Static_reloc(got_offset,
7083 elfcpp::R_ARM_TLS_DTPOFF32,
7084 gsym));
7085 }
7086
7087 // Same as the above but for a local symbol.
7088
7089 template<bool big_endian>
7090 void
7091 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
7092 unsigned int got_type,
7093 Sized_relobj_file<32, big_endian>* object,
7094 unsigned int index)
7095 {
7096 if (object->local_has_got_offset(index, got_type))
7097 return;
7098
7099 // We are doing a static link. Just mark it as belong to module 1,
7100 // the executable.
7101 unsigned int got_offset = this->add_constant(1);
7102 object->set_local_got_offset(index, got_type, got_offset);
7103 got_offset = this->add_constant(0);
7104 this->static_relocs_.push_back(Static_reloc(got_offset,
7105 elfcpp::R_ARM_TLS_DTPOFF32,
7106 object, index));
7107 }
7108
7109 template<bool big_endian>
7110 void
7111 Arm_output_data_got<big_endian>::do_write(Output_file* of)
7112 {
7113 // Call parent to write out GOT.
7114 Output_data_got<32, big_endian>::do_write(of);
7115
7116 // We are done if there is no fix up.
7117 if (this->static_relocs_.empty())
7118 return;
7119
7120 gold_assert(parameters->doing_static_link());
7121
7122 const off_t offset = this->offset();
7123 const section_size_type oview_size =
7124 convert_to_section_size_type(this->data_size());
7125 unsigned char* const oview = of->get_output_view(offset, oview_size);
7126
7127 Output_segment* tls_segment = this->layout_->tls_segment();
7128 gold_assert(tls_segment != NULL);
7129
7130 // The thread pointer $tp points to the TCB, which is followed by the
7131 // TLS. So we need to adjust $tp relative addressing by this amount.
7132 Arm_address aligned_tcb_size =
7133 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
7134
7135 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
7136 {
7137 Static_reloc& reloc(this->static_relocs_[i]);
7138
7139 Arm_address value;
7140 if (!reloc.symbol_is_global())
7141 {
7142 Sized_relobj_file<32, big_endian>* object = reloc.relobj();
7143 const Symbol_value<32>* psymval =
7144 reloc.relobj()->local_symbol(reloc.index());
7145
7146 // We are doing static linking. Issue an error and skip this
7147 // relocation if the symbol is undefined or in a discarded_section.
7148 bool is_ordinary;
7149 unsigned int shndx = psymval->input_shndx(&is_ordinary);
7150 if ((shndx == elfcpp::SHN_UNDEF)
7151 || (is_ordinary
7152 && shndx != elfcpp::SHN_UNDEF
7153 && !object->is_section_included(shndx)
7154 && !this->symbol_table_->is_section_folded(object, shndx)))
7155 {
7156 gold_error(_("undefined or discarded local symbol %u from "
7157 " object %s in GOT"),
7158 reloc.index(), reloc.relobj()->name().c_str());
7159 continue;
7160 }
7161
7162 value = psymval->value(object, 0);
7163 }
7164 else
7165 {
7166 const Symbol* gsym = reloc.symbol();
7167 gold_assert(gsym != NULL);
7168 if (gsym->is_forwarder())
7169 gsym = this->symbol_table_->resolve_forwards(gsym);
7170
7171 // We are doing static linking. Issue an error and skip this
7172 // relocation if the symbol is undefined or in a discarded_section
7173 // unless it is a weakly_undefined symbol.
7174 if ((gsym->is_defined_in_discarded_section()
7175 || gsym->is_undefined())
7176 && !gsym->is_weak_undefined())
7177 {
7178 gold_error(_("undefined or discarded symbol %s in GOT"),
7179 gsym->name());
7180 continue;
7181 }
7182
7183 if (!gsym->is_weak_undefined())
7184 {
7185 const Sized_symbol<32>* sym =
7186 static_cast<const Sized_symbol<32>*>(gsym);
7187 value = sym->value();
7188 }
7189 else
7190 value = 0;
7191 }
7192
7193 unsigned got_offset = reloc.got_offset();
7194 gold_assert(got_offset < oview_size);
7195
7196 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
7197 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
7198 Valtype x;
7199 switch (reloc.r_type())
7200 {
7201 case elfcpp::R_ARM_TLS_DTPOFF32:
7202 x = value;
7203 break;
7204 case elfcpp::R_ARM_TLS_TPOFF32:
7205 x = value + aligned_tcb_size;
7206 break;
7207 default:
7208 gold_unreachable();
7209 }
7210 elfcpp::Swap<32, big_endian>::writeval(wv, x);
7211 }
7212
7213 of->write_output_view(offset, oview_size, oview);
7214 }
7215
7216 // A class to handle the PLT data.
7217 // This is an abstract base class that handles most of the linker details
7218 // but does not know the actual contents of PLT entries. The derived
7219 // classes below fill in those details.
7220
7221 template<bool big_endian>
7222 class Output_data_plt_arm : public Output_section_data
7223 {
7224 public:
7225 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
7226 Reloc_section;
7227
7228 Output_data_plt_arm(Layout*, uint64_t addralign, Output_data_space*);
7229
7230 // Add an entry to the PLT.
7231 void
7232 add_entry(Symbol* gsym);
7233
7234 // Return the .rel.plt section data.
7235 const Reloc_section*
7236 rel_plt() const
7237 { return this->rel_; }
7238
7239 // Return the number of PLT entries.
7240 unsigned int
7241 entry_count() const
7242 { return this->count_; }
7243
7244 // Return the offset of the first non-reserved PLT entry.
7245 unsigned int
7246 first_plt_entry_offset() const
7247 { return this->do_first_plt_entry_offset(); }
7248
7249 // Return the size of a PLT entry.
7250 unsigned int
7251 get_plt_entry_size() const
7252 { return this->do_get_plt_entry_size(); }
7253
7254 protected:
7255 // Fill in the first PLT entry.
7256 void
7257 fill_first_plt_entry(unsigned char* pov,
7258 Arm_address got_address,
7259 Arm_address plt_address)
7260 { this->do_fill_first_plt_entry(pov, got_address, plt_address); }
7261
7262 void
7263 fill_plt_entry(unsigned char* pov,
7264 Arm_address got_address,
7265 Arm_address plt_address,
7266 unsigned int got_offset,
7267 unsigned int plt_offset)
7268 { do_fill_plt_entry(pov, got_address, plt_address, got_offset, plt_offset); }
7269
7270 virtual unsigned int
7271 do_first_plt_entry_offset() const = 0;
7272
7273 virtual unsigned int
7274 do_get_plt_entry_size() const = 0;
7275
7276 virtual void
7277 do_fill_first_plt_entry(unsigned char* pov,
7278 Arm_address got_address,
7279 Arm_address plt_address) = 0;
7280
7281 virtual void
7282 do_fill_plt_entry(unsigned char* pov,
7283 Arm_address got_address,
7284 Arm_address plt_address,
7285 unsigned int got_offset,
7286 unsigned int plt_offset) = 0;
7287
7288 void
7289 do_adjust_output_section(Output_section* os);
7290
7291 // Write to a map file.
7292 void
7293 do_print_to_mapfile(Mapfile* mapfile) const
7294 { mapfile->print_output_data(this, _("** PLT")); }
7295
7296 private:
7297 // Set the final size.
7298 void
7299 set_final_data_size()
7300 {
7301 this->set_data_size(this->first_plt_entry_offset()
7302 + this->count_ * this->get_plt_entry_size());
7303 }
7304
7305 // Write out the PLT data.
7306 void
7307 do_write(Output_file*);
7308
7309 // The reloc section.
7310 Reloc_section* rel_;
7311 // The .got.plt section.
7312 Output_data_space* got_plt_;
7313 // The number of PLT entries.
7314 unsigned int count_;
7315 };
7316
7317 // Create the PLT section. The ordinary .got section is an argument,
7318 // since we need to refer to the start. We also create our own .got
7319 // section just for PLT entries.
7320
7321 template<bool big_endian>
7322 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
7323 uint64_t addralign,
7324 Output_data_space* got_plt)
7325 : Output_section_data(addralign), got_plt_(got_plt), count_(0)
7326 {
7327 this->rel_ = new Reloc_section(false);
7328 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
7329 elfcpp::SHF_ALLOC, this->rel_,
7330 ORDER_DYNAMIC_PLT_RELOCS, false);
7331 }
7332
7333 template<bool big_endian>
7334 void
7335 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
7336 {
7337 os->set_entsize(0);
7338 }
7339
7340 // Add an entry to the PLT.
7341
7342 template<bool big_endian>
7343 void
7344 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
7345 {
7346 gold_assert(!gsym->has_plt_offset());
7347
7348 // Note that when setting the PLT offset we skip the initial
7349 // reserved PLT entry.
7350 gsym->set_plt_offset((this->count_) * this->get_plt_entry_size()
7351 + this->first_plt_entry_offset());
7352
7353 ++this->count_;
7354
7355 section_offset_type got_offset = this->got_plt_->current_data_size();
7356
7357 // Every PLT entry needs a GOT entry which points back to the PLT
7358 // entry (this will be changed by the dynamic linker, normally
7359 // lazily when the function is called).
7360 this->got_plt_->set_current_data_size(got_offset + 4);
7361
7362 // Every PLT entry needs a reloc.
7363 gsym->set_needs_dynsym_entry();
7364 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
7365 got_offset);
7366
7367 // Note that we don't need to save the symbol. The contents of the
7368 // PLT are independent of which symbols are used. The symbols only
7369 // appear in the relocations.
7370 }
7371
7372 template<bool big_endian>
7373 class Output_data_plt_arm_standard : public Output_data_plt_arm<big_endian>
7374 {
7375 public:
7376 Output_data_plt_arm_standard(Layout* layout, Output_data_space* got_plt)
7377 : Output_data_plt_arm<big_endian>(layout, 4, got_plt)
7378 { }
7379
7380 protected:
7381 // Return the offset of the first non-reserved PLT entry.
7382 virtual unsigned int
7383 do_first_plt_entry_offset() const
7384 { return sizeof(first_plt_entry); }
7385
7386 // Return the size of a PLT entry.
7387 virtual unsigned int
7388 do_get_plt_entry_size() const
7389 { return sizeof(plt_entry); }
7390
7391 virtual void
7392 do_fill_first_plt_entry(unsigned char* pov,
7393 Arm_address got_address,
7394 Arm_address plt_address);
7395
7396 virtual void
7397 do_fill_plt_entry(unsigned char* pov,
7398 Arm_address got_address,
7399 Arm_address plt_address,
7400 unsigned int got_offset,
7401 unsigned int plt_offset);
7402
7403 private:
7404 // Template for the first PLT entry.
7405 static const uint32_t first_plt_entry[5];
7406
7407 // Template for subsequent PLT entries.
7408 static const uint32_t plt_entry[3];
7409 };
7410
7411 // ARM PLTs.
7412 // FIXME: This is not very flexible. Right now this has only been tested
7413 // on armv5te. If we are to support additional architecture features like
7414 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
7415
7416 // The first entry in the PLT.
7417 template<bool big_endian>
7418 const uint32_t Output_data_plt_arm_standard<big_endian>::first_plt_entry[5] =
7419 {
7420 0xe52de004, // str lr, [sp, #-4]!
7421 0xe59fe004, // ldr lr, [pc, #4]
7422 0xe08fe00e, // add lr, pc, lr
7423 0xe5bef008, // ldr pc, [lr, #8]!
7424 0x00000000, // &GOT[0] - .
7425 };
7426
7427 template<bool big_endian>
7428 void
7429 Output_data_plt_arm_standard<big_endian>::do_fill_first_plt_entry(
7430 unsigned char* pov,
7431 Arm_address got_address,
7432 Arm_address plt_address)
7433 {
7434 // Write first PLT entry. All but the last word are constants.
7435 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7436 / sizeof(plt_entry[0]));
7437 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7438 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7439 // Last word in first PLT entry is &GOT[0] - .
7440 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7441 got_address - (plt_address + 16));
7442 }
7443
7444 // Subsequent entries in the PLT.
7445
7446 template<bool big_endian>
7447 const uint32_t Output_data_plt_arm_standard<big_endian>::plt_entry[3] =
7448 {
7449 0xe28fc600, // add ip, pc, #0xNN00000
7450 0xe28cca00, // add ip, ip, #0xNN000
7451 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7452 };
7453
7454 template<bool big_endian>
7455 void
7456 Output_data_plt_arm_standard<big_endian>::do_fill_plt_entry(
7457 unsigned char* pov,
7458 Arm_address got_address,
7459 Arm_address plt_address,
7460 unsigned int got_offset,
7461 unsigned int plt_offset)
7462 {
7463 int32_t offset = ((got_address + got_offset)
7464 - (plt_address + plt_offset + 8));
7465
7466 gold_assert(offset >= 0 && offset < 0x0fffffff);
7467 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7468 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7469 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7470 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7471 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7472 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7473 }
7474
7475 // Write out the PLT. This uses the hand-coded instructions above,
7476 // and adjusts them as needed. This is all specified by the arm ELF
7477 // Processor Supplement.
7478
7479 template<bool big_endian>
7480 void
7481 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7482 {
7483 const off_t offset = this->offset();
7484 const section_size_type oview_size =
7485 convert_to_section_size_type(this->data_size());
7486 unsigned char* const oview = of->get_output_view(offset, oview_size);
7487
7488 const off_t got_file_offset = this->got_plt_->offset();
7489 const section_size_type got_size =
7490 convert_to_section_size_type(this->got_plt_->data_size());
7491 unsigned char* const got_view = of->get_output_view(got_file_offset,
7492 got_size);
7493 unsigned char* pov = oview;
7494
7495 Arm_address plt_address = this->address();
7496 Arm_address got_address = this->got_plt_->address();
7497
7498 // Write first PLT entry.
7499 this->fill_first_plt_entry(pov, got_address, plt_address);
7500 pov += this->first_plt_entry_offset();
7501
7502 unsigned char* got_pov = got_view;
7503
7504 memset(got_pov, 0, 12);
7505 got_pov += 12;
7506
7507 unsigned int plt_offset = this->first_plt_entry_offset();
7508 unsigned int got_offset = 12;
7509 const unsigned int count = this->count_;
7510 for (unsigned int i = 0;
7511 i < count;
7512 ++i,
7513 pov += this->get_plt_entry_size(),
7514 got_pov += 4,
7515 plt_offset += this->get_plt_entry_size(),
7516 got_offset += 4)
7517 {
7518 // Set and adjust the PLT entry itself.
7519 this->fill_plt_entry(pov, got_address, plt_address,
7520 got_offset, plt_offset);
7521
7522 // Set the entry in the GOT.
7523 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7524 }
7525
7526 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7527 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7528
7529 of->write_output_view(offset, oview_size, oview);
7530 of->write_output_view(got_file_offset, got_size, got_view);
7531 }
7532
7533 // Create a PLT entry for a global symbol.
7534
7535 template<bool big_endian>
7536 void
7537 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7538 Symbol* gsym)
7539 {
7540 if (gsym->has_plt_offset())
7541 return;
7542
7543 if (this->plt_ == NULL)
7544 {
7545 // Create the GOT sections first.
7546 this->got_section(symtab, layout);
7547
7548 this->plt_ = this->make_data_plt(layout, this->got_plt_);
7549
7550 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7551 (elfcpp::SHF_ALLOC
7552 | elfcpp::SHF_EXECINSTR),
7553 this->plt_, ORDER_PLT, false);
7554 }
7555 this->plt_->add_entry(gsym);
7556 }
7557
7558 // Return the number of entries in the PLT.
7559
7560 template<bool big_endian>
7561 unsigned int
7562 Target_arm<big_endian>::plt_entry_count() const
7563 {
7564 if (this->plt_ == NULL)
7565 return 0;
7566 return this->plt_->entry_count();
7567 }
7568
7569 // Return the offset of the first non-reserved PLT entry.
7570
7571 template<bool big_endian>
7572 unsigned int
7573 Target_arm<big_endian>::first_plt_entry_offset() const
7574 {
7575 return this->plt_->first_plt_entry_offset();
7576 }
7577
7578 // Return the size of each PLT entry.
7579
7580 template<bool big_endian>
7581 unsigned int
7582 Target_arm<big_endian>::plt_entry_size() const
7583 {
7584 return this->plt_->get_plt_entry_size();
7585 }
7586
7587 // Get the section to use for TLS_DESC relocations.
7588
7589 template<bool big_endian>
7590 typename Target_arm<big_endian>::Reloc_section*
7591 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7592 {
7593 return this->plt_section()->rel_tls_desc(layout);
7594 }
7595
7596 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7597
7598 template<bool big_endian>
7599 void
7600 Target_arm<big_endian>::define_tls_base_symbol(
7601 Symbol_table* symtab,
7602 Layout* layout)
7603 {
7604 if (this->tls_base_symbol_defined_)
7605 return;
7606
7607 Output_segment* tls_segment = layout->tls_segment();
7608 if (tls_segment != NULL)
7609 {
7610 bool is_exec = parameters->options().output_is_executable();
7611 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7612 Symbol_table::PREDEFINED,
7613 tls_segment, 0, 0,
7614 elfcpp::STT_TLS,
7615 elfcpp::STB_LOCAL,
7616 elfcpp::STV_HIDDEN, 0,
7617 (is_exec
7618 ? Symbol::SEGMENT_END
7619 : Symbol::SEGMENT_START),
7620 true);
7621 }
7622 this->tls_base_symbol_defined_ = true;
7623 }
7624
7625 // Create a GOT entry for the TLS module index.
7626
7627 template<bool big_endian>
7628 unsigned int
7629 Target_arm<big_endian>::got_mod_index_entry(
7630 Symbol_table* symtab,
7631 Layout* layout,
7632 Sized_relobj_file<32, big_endian>* object)
7633 {
7634 if (this->got_mod_index_offset_ == -1U)
7635 {
7636 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7637 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7638 unsigned int got_offset;
7639 if (!parameters->doing_static_link())
7640 {
7641 got_offset = got->add_constant(0);
7642 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7643 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7644 got_offset);
7645 }
7646 else
7647 {
7648 // We are doing a static link. Just mark it as belong to module 1,
7649 // the executable.
7650 got_offset = got->add_constant(1);
7651 }
7652
7653 got->add_constant(0);
7654 this->got_mod_index_offset_ = got_offset;
7655 }
7656 return this->got_mod_index_offset_;
7657 }
7658
7659 // Optimize the TLS relocation type based on what we know about the
7660 // symbol. IS_FINAL is true if the final address of this symbol is
7661 // known at link time.
7662
7663 template<bool big_endian>
7664 tls::Tls_optimization
7665 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7666 {
7667 // FIXME: Currently we do not do any TLS optimization.
7668 return tls::TLSOPT_NONE;
7669 }
7670
7671 // Get the Reference_flags for a particular relocation.
7672
7673 template<bool big_endian>
7674 int
7675 Target_arm<big_endian>::Scan::get_reference_flags(unsigned int r_type)
7676 {
7677 switch (r_type)
7678 {
7679 case elfcpp::R_ARM_NONE:
7680 case elfcpp::R_ARM_V4BX:
7681 case elfcpp::R_ARM_GNU_VTENTRY:
7682 case elfcpp::R_ARM_GNU_VTINHERIT:
7683 // No symbol reference.
7684 return 0;
7685
7686 case elfcpp::R_ARM_ABS32:
7687 case elfcpp::R_ARM_ABS16:
7688 case elfcpp::R_ARM_ABS12:
7689 case elfcpp::R_ARM_THM_ABS5:
7690 case elfcpp::R_ARM_ABS8:
7691 case elfcpp::R_ARM_BASE_ABS:
7692 case elfcpp::R_ARM_MOVW_ABS_NC:
7693 case elfcpp::R_ARM_MOVT_ABS:
7694 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7695 case elfcpp::R_ARM_THM_MOVT_ABS:
7696 case elfcpp::R_ARM_ABS32_NOI:
7697 return Symbol::ABSOLUTE_REF;
7698
7699 case elfcpp::R_ARM_REL32:
7700 case elfcpp::R_ARM_LDR_PC_G0:
7701 case elfcpp::R_ARM_SBREL32:
7702 case elfcpp::R_ARM_THM_PC8:
7703 case elfcpp::R_ARM_BASE_PREL:
7704 case elfcpp::R_ARM_MOVW_PREL_NC:
7705 case elfcpp::R_ARM_MOVT_PREL:
7706 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7707 case elfcpp::R_ARM_THM_MOVT_PREL:
7708 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7709 case elfcpp::R_ARM_THM_PC12:
7710 case elfcpp::R_ARM_REL32_NOI:
7711 case elfcpp::R_ARM_ALU_PC_G0_NC:
7712 case elfcpp::R_ARM_ALU_PC_G0:
7713 case elfcpp::R_ARM_ALU_PC_G1_NC:
7714 case elfcpp::R_ARM_ALU_PC_G1:
7715 case elfcpp::R_ARM_ALU_PC_G2:
7716 case elfcpp::R_ARM_LDR_PC_G1:
7717 case elfcpp::R_ARM_LDR_PC_G2:
7718 case elfcpp::R_ARM_LDRS_PC_G0:
7719 case elfcpp::R_ARM_LDRS_PC_G1:
7720 case elfcpp::R_ARM_LDRS_PC_G2:
7721 case elfcpp::R_ARM_LDC_PC_G0:
7722 case elfcpp::R_ARM_LDC_PC_G1:
7723 case elfcpp::R_ARM_LDC_PC_G2:
7724 case elfcpp::R_ARM_ALU_SB_G0_NC:
7725 case elfcpp::R_ARM_ALU_SB_G0:
7726 case elfcpp::R_ARM_ALU_SB_G1_NC:
7727 case elfcpp::R_ARM_ALU_SB_G1:
7728 case elfcpp::R_ARM_ALU_SB_G2:
7729 case elfcpp::R_ARM_LDR_SB_G0:
7730 case elfcpp::R_ARM_LDR_SB_G1:
7731 case elfcpp::R_ARM_LDR_SB_G2:
7732 case elfcpp::R_ARM_LDRS_SB_G0:
7733 case elfcpp::R_ARM_LDRS_SB_G1:
7734 case elfcpp::R_ARM_LDRS_SB_G2:
7735 case elfcpp::R_ARM_LDC_SB_G0:
7736 case elfcpp::R_ARM_LDC_SB_G1:
7737 case elfcpp::R_ARM_LDC_SB_G2:
7738 case elfcpp::R_ARM_MOVW_BREL_NC:
7739 case elfcpp::R_ARM_MOVT_BREL:
7740 case elfcpp::R_ARM_MOVW_BREL:
7741 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7742 case elfcpp::R_ARM_THM_MOVT_BREL:
7743 case elfcpp::R_ARM_THM_MOVW_BREL:
7744 case elfcpp::R_ARM_GOTOFF32:
7745 case elfcpp::R_ARM_GOTOFF12:
7746 case elfcpp::R_ARM_SBREL31:
7747 return Symbol::RELATIVE_REF;
7748
7749 case elfcpp::R_ARM_PLT32:
7750 case elfcpp::R_ARM_CALL:
7751 case elfcpp::R_ARM_JUMP24:
7752 case elfcpp::R_ARM_THM_CALL:
7753 case elfcpp::R_ARM_THM_JUMP24:
7754 case elfcpp::R_ARM_THM_JUMP19:
7755 case elfcpp::R_ARM_THM_JUMP6:
7756 case elfcpp::R_ARM_THM_JUMP11:
7757 case elfcpp::R_ARM_THM_JUMP8:
7758 // R_ARM_PREL31 is not used to relocate call/jump instructions but
7759 // in unwind tables. It may point to functions via PLTs.
7760 // So we treat it like call/jump relocations above.
7761 case elfcpp::R_ARM_PREL31:
7762 return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
7763
7764 case elfcpp::R_ARM_GOT_BREL:
7765 case elfcpp::R_ARM_GOT_ABS:
7766 case elfcpp::R_ARM_GOT_PREL:
7767 // Absolute in GOT.
7768 return Symbol::ABSOLUTE_REF;
7769
7770 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7771 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7772 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7773 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7774 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7775 return Symbol::TLS_REF;
7776
7777 case elfcpp::R_ARM_TARGET1:
7778 case elfcpp::R_ARM_TARGET2:
7779 case elfcpp::R_ARM_COPY:
7780 case elfcpp::R_ARM_GLOB_DAT:
7781 case elfcpp::R_ARM_JUMP_SLOT:
7782 case elfcpp::R_ARM_RELATIVE:
7783 case elfcpp::R_ARM_PC24:
7784 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7785 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7786 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7787 default:
7788 // Not expected. We will give an error later.
7789 return 0;
7790 }
7791 }
7792
7793 // Report an unsupported relocation against a local symbol.
7794
7795 template<bool big_endian>
7796 void
7797 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7798 Sized_relobj_file<32, big_endian>* object,
7799 unsigned int r_type)
7800 {
7801 gold_error(_("%s: unsupported reloc %u against local symbol"),
7802 object->name().c_str(), r_type);
7803 }
7804
7805 // We are about to emit a dynamic relocation of type R_TYPE. If the
7806 // dynamic linker does not support it, issue an error. The GNU linker
7807 // only issues a non-PIC error for an allocated read-only section.
7808 // Here we know the section is allocated, but we don't know that it is
7809 // read-only. But we check for all the relocation types which the
7810 // glibc dynamic linker supports, so it seems appropriate to issue an
7811 // error even if the section is not read-only.
7812
7813 template<bool big_endian>
7814 void
7815 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7816 unsigned int r_type)
7817 {
7818 switch (r_type)
7819 {
7820 // These are the relocation types supported by glibc for ARM.
7821 case elfcpp::R_ARM_RELATIVE:
7822 case elfcpp::R_ARM_COPY:
7823 case elfcpp::R_ARM_GLOB_DAT:
7824 case elfcpp::R_ARM_JUMP_SLOT:
7825 case elfcpp::R_ARM_ABS32:
7826 case elfcpp::R_ARM_ABS32_NOI:
7827 case elfcpp::R_ARM_PC24:
7828 // FIXME: The following 3 types are not supported by Android's dynamic
7829 // linker.
7830 case elfcpp::R_ARM_TLS_DTPMOD32:
7831 case elfcpp::R_ARM_TLS_DTPOFF32:
7832 case elfcpp::R_ARM_TLS_TPOFF32:
7833 return;
7834
7835 default:
7836 {
7837 // This prevents us from issuing more than one error per reloc
7838 // section. But we can still wind up issuing more than one
7839 // error per object file.
7840 if (this->issued_non_pic_error_)
7841 return;
7842 const Arm_reloc_property* reloc_property =
7843 arm_reloc_property_table->get_reloc_property(r_type);
7844 gold_assert(reloc_property != NULL);
7845 object->error(_("requires unsupported dynamic reloc %s; "
7846 "recompile with -fPIC"),
7847 reloc_property->name().c_str());
7848 this->issued_non_pic_error_ = true;
7849 return;
7850 }
7851
7852 case elfcpp::R_ARM_NONE:
7853 gold_unreachable();
7854 }
7855 }
7856
7857 // Scan a relocation for a local symbol.
7858 // FIXME: This only handles a subset of relocation types used by Android
7859 // on ARM v5te devices.
7860
7861 template<bool big_endian>
7862 inline void
7863 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7864 Layout* layout,
7865 Target_arm* target,
7866 Sized_relobj_file<32, big_endian>* object,
7867 unsigned int data_shndx,
7868 Output_section* output_section,
7869 const elfcpp::Rel<32, big_endian>& reloc,
7870 unsigned int r_type,
7871 const elfcpp::Sym<32, big_endian>& lsym,
7872 bool is_discarded)
7873 {
7874 if (is_discarded)
7875 return;
7876
7877 r_type = get_real_reloc_type(r_type);
7878 switch (r_type)
7879 {
7880 case elfcpp::R_ARM_NONE:
7881 case elfcpp::R_ARM_V4BX:
7882 case elfcpp::R_ARM_GNU_VTENTRY:
7883 case elfcpp::R_ARM_GNU_VTINHERIT:
7884 break;
7885
7886 case elfcpp::R_ARM_ABS32:
7887 case elfcpp::R_ARM_ABS32_NOI:
7888 // If building a shared library (or a position-independent
7889 // executable), we need to create a dynamic relocation for
7890 // this location. The relocation applied at link time will
7891 // apply the link-time value, so we flag the location with
7892 // an R_ARM_RELATIVE relocation so the dynamic loader can
7893 // relocate it easily.
7894 if (parameters->options().output_is_position_independent())
7895 {
7896 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7897 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7898 // If we are to add more other reloc types than R_ARM_ABS32,
7899 // we need to add check_non_pic(object, r_type) here.
7900 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7901 output_section, data_shndx,
7902 reloc.get_r_offset());
7903 }
7904 break;
7905
7906 case elfcpp::R_ARM_ABS16:
7907 case elfcpp::R_ARM_ABS12:
7908 case elfcpp::R_ARM_THM_ABS5:
7909 case elfcpp::R_ARM_ABS8:
7910 case elfcpp::R_ARM_BASE_ABS:
7911 case elfcpp::R_ARM_MOVW_ABS_NC:
7912 case elfcpp::R_ARM_MOVT_ABS:
7913 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7914 case elfcpp::R_ARM_THM_MOVT_ABS:
7915 // If building a shared library (or a position-independent
7916 // executable), we need to create a dynamic relocation for
7917 // this location. Because the addend needs to remain in the
7918 // data section, we need to be careful not to apply this
7919 // relocation statically.
7920 if (parameters->options().output_is_position_independent())
7921 {
7922 check_non_pic(object, r_type);
7923 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7924 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7925 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7926 rel_dyn->add_local(object, r_sym, r_type, output_section,
7927 data_shndx, reloc.get_r_offset());
7928 else
7929 {
7930 gold_assert(lsym.get_st_value() == 0);
7931 unsigned int shndx = lsym.get_st_shndx();
7932 bool is_ordinary;
7933 shndx = object->adjust_sym_shndx(r_sym, shndx,
7934 &is_ordinary);
7935 if (!is_ordinary)
7936 object->error(_("section symbol %u has bad shndx %u"),
7937 r_sym, shndx);
7938 else
7939 rel_dyn->add_local_section(object, shndx,
7940 r_type, output_section,
7941 data_shndx, reloc.get_r_offset());
7942 }
7943 }
7944 break;
7945
7946 case elfcpp::R_ARM_REL32:
7947 case elfcpp::R_ARM_LDR_PC_G0:
7948 case elfcpp::R_ARM_SBREL32:
7949 case elfcpp::R_ARM_THM_CALL:
7950 case elfcpp::R_ARM_THM_PC8:
7951 case elfcpp::R_ARM_BASE_PREL:
7952 case elfcpp::R_ARM_PLT32:
7953 case elfcpp::R_ARM_CALL:
7954 case elfcpp::R_ARM_JUMP24:
7955 case elfcpp::R_ARM_THM_JUMP24:
7956 case elfcpp::R_ARM_SBREL31:
7957 case elfcpp::R_ARM_PREL31:
7958 case elfcpp::R_ARM_MOVW_PREL_NC:
7959 case elfcpp::R_ARM_MOVT_PREL:
7960 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7961 case elfcpp::R_ARM_THM_MOVT_PREL:
7962 case elfcpp::R_ARM_THM_JUMP19:
7963 case elfcpp::R_ARM_THM_JUMP6:
7964 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7965 case elfcpp::R_ARM_THM_PC12:
7966 case elfcpp::R_ARM_REL32_NOI:
7967 case elfcpp::R_ARM_ALU_PC_G0_NC:
7968 case elfcpp::R_ARM_ALU_PC_G0:
7969 case elfcpp::R_ARM_ALU_PC_G1_NC:
7970 case elfcpp::R_ARM_ALU_PC_G1:
7971 case elfcpp::R_ARM_ALU_PC_G2:
7972 case elfcpp::R_ARM_LDR_PC_G1:
7973 case elfcpp::R_ARM_LDR_PC_G2:
7974 case elfcpp::R_ARM_LDRS_PC_G0:
7975 case elfcpp::R_ARM_LDRS_PC_G1:
7976 case elfcpp::R_ARM_LDRS_PC_G2:
7977 case elfcpp::R_ARM_LDC_PC_G0:
7978 case elfcpp::R_ARM_LDC_PC_G1:
7979 case elfcpp::R_ARM_LDC_PC_G2:
7980 case elfcpp::R_ARM_ALU_SB_G0_NC:
7981 case elfcpp::R_ARM_ALU_SB_G0:
7982 case elfcpp::R_ARM_ALU_SB_G1_NC:
7983 case elfcpp::R_ARM_ALU_SB_G1:
7984 case elfcpp::R_ARM_ALU_SB_G2:
7985 case elfcpp::R_ARM_LDR_SB_G0:
7986 case elfcpp::R_ARM_LDR_SB_G1:
7987 case elfcpp::R_ARM_LDR_SB_G2:
7988 case elfcpp::R_ARM_LDRS_SB_G0:
7989 case elfcpp::R_ARM_LDRS_SB_G1:
7990 case elfcpp::R_ARM_LDRS_SB_G2:
7991 case elfcpp::R_ARM_LDC_SB_G0:
7992 case elfcpp::R_ARM_LDC_SB_G1:
7993 case elfcpp::R_ARM_LDC_SB_G2:
7994 case elfcpp::R_ARM_MOVW_BREL_NC:
7995 case elfcpp::R_ARM_MOVT_BREL:
7996 case elfcpp::R_ARM_MOVW_BREL:
7997 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7998 case elfcpp::R_ARM_THM_MOVT_BREL:
7999 case elfcpp::R_ARM_THM_MOVW_BREL:
8000 case elfcpp::R_ARM_THM_JUMP11:
8001 case elfcpp::R_ARM_THM_JUMP8:
8002 // We don't need to do anything for a relative addressing relocation
8003 // against a local symbol if it does not reference the GOT.
8004 break;
8005
8006 case elfcpp::R_ARM_GOTOFF32:
8007 case elfcpp::R_ARM_GOTOFF12:
8008 // We need a GOT section:
8009 target->got_section(symtab, layout);
8010 break;
8011
8012 case elfcpp::R_ARM_GOT_BREL:
8013 case elfcpp::R_ARM_GOT_PREL:
8014 {
8015 // The symbol requires a GOT entry.
8016 Arm_output_data_got<big_endian>* got =
8017 target->got_section(symtab, layout);
8018 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8019 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
8020 {
8021 // If we are generating a shared object, we need to add a
8022 // dynamic RELATIVE relocation for this symbol's GOT entry.
8023 if (parameters->options().output_is_position_independent())
8024 {
8025 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8026 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8027 rel_dyn->add_local_relative(
8028 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
8029 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
8030 }
8031 }
8032 }
8033 break;
8034
8035 case elfcpp::R_ARM_TARGET1:
8036 case elfcpp::R_ARM_TARGET2:
8037 // This should have been mapped to another type already.
8038 // Fall through.
8039 case elfcpp::R_ARM_COPY:
8040 case elfcpp::R_ARM_GLOB_DAT:
8041 case elfcpp::R_ARM_JUMP_SLOT:
8042 case elfcpp::R_ARM_RELATIVE:
8043 // These are relocations which should only be seen by the
8044 // dynamic linker, and should never be seen here.
8045 gold_error(_("%s: unexpected reloc %u in object file"),
8046 object->name().c_str(), r_type);
8047 break;
8048
8049
8050 // These are initial TLS relocs, which are expected when
8051 // linking.
8052 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8053 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8054 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8055 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8056 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8057 {
8058 bool output_is_shared = parameters->options().shared();
8059 const tls::Tls_optimization optimized_type
8060 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
8061 r_type);
8062 switch (r_type)
8063 {
8064 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8065 if (optimized_type == tls::TLSOPT_NONE)
8066 {
8067 // Create a pair of GOT entries for the module index and
8068 // dtv-relative offset.
8069 Arm_output_data_got<big_endian>* got
8070 = target->got_section(symtab, layout);
8071 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8072 unsigned int shndx = lsym.get_st_shndx();
8073 bool is_ordinary;
8074 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
8075 if (!is_ordinary)
8076 {
8077 object->error(_("local symbol %u has bad shndx %u"),
8078 r_sym, shndx);
8079 break;
8080 }
8081
8082 if (!parameters->doing_static_link())
8083 got->add_local_pair_with_rel(object, r_sym, shndx,
8084 GOT_TYPE_TLS_PAIR,
8085 target->rel_dyn_section(layout),
8086 elfcpp::R_ARM_TLS_DTPMOD32);
8087 else
8088 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
8089 object, r_sym);
8090 }
8091 else
8092 // FIXME: TLS optimization not supported yet.
8093 gold_unreachable();
8094 break;
8095
8096 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8097 if (optimized_type == tls::TLSOPT_NONE)
8098 {
8099 // Create a GOT entry for the module index.
8100 target->got_mod_index_entry(symtab, layout, object);
8101 }
8102 else
8103 // FIXME: TLS optimization not supported yet.
8104 gold_unreachable();
8105 break;
8106
8107 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8108 break;
8109
8110 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8111 layout->set_has_static_tls();
8112 if (optimized_type == tls::TLSOPT_NONE)
8113 {
8114 // Create a GOT entry for the tp-relative offset.
8115 Arm_output_data_got<big_endian>* got
8116 = target->got_section(symtab, layout);
8117 unsigned int r_sym =
8118 elfcpp::elf_r_sym<32>(reloc.get_r_info());
8119 if (!parameters->doing_static_link())
8120 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
8121 target->rel_dyn_section(layout),
8122 elfcpp::R_ARM_TLS_TPOFF32);
8123 else if (!object->local_has_got_offset(r_sym,
8124 GOT_TYPE_TLS_OFFSET))
8125 {
8126 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
8127 unsigned int got_offset =
8128 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
8129 got->add_static_reloc(got_offset,
8130 elfcpp::R_ARM_TLS_TPOFF32, object,
8131 r_sym);
8132 }
8133 }
8134 else
8135 // FIXME: TLS optimization not supported yet.
8136 gold_unreachable();
8137 break;
8138
8139 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8140 layout->set_has_static_tls();
8141 if (output_is_shared)
8142 {
8143 // We need to create a dynamic relocation.
8144 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
8145 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
8146 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8147 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
8148 output_section, data_shndx,
8149 reloc.get_r_offset());
8150 }
8151 break;
8152
8153 default:
8154 gold_unreachable();
8155 }
8156 }
8157 break;
8158
8159 case elfcpp::R_ARM_PC24:
8160 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8161 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8162 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8163 default:
8164 unsupported_reloc_local(object, r_type);
8165 break;
8166 }
8167 }
8168
8169 // Report an unsupported relocation against a global symbol.
8170
8171 template<bool big_endian>
8172 void
8173 Target_arm<big_endian>::Scan::unsupported_reloc_global(
8174 Sized_relobj_file<32, big_endian>* object,
8175 unsigned int r_type,
8176 Symbol* gsym)
8177 {
8178 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
8179 object->name().c_str(), r_type, gsym->demangled_name().c_str());
8180 }
8181
8182 template<bool big_endian>
8183 inline bool
8184 Target_arm<big_endian>::Scan::possible_function_pointer_reloc(
8185 unsigned int r_type)
8186 {
8187 switch (r_type)
8188 {
8189 case elfcpp::R_ARM_PC24:
8190 case elfcpp::R_ARM_THM_CALL:
8191 case elfcpp::R_ARM_PLT32:
8192 case elfcpp::R_ARM_CALL:
8193 case elfcpp::R_ARM_JUMP24:
8194 case elfcpp::R_ARM_THM_JUMP24:
8195 case elfcpp::R_ARM_SBREL31:
8196 case elfcpp::R_ARM_PREL31:
8197 case elfcpp::R_ARM_THM_JUMP19:
8198 case elfcpp::R_ARM_THM_JUMP6:
8199 case elfcpp::R_ARM_THM_JUMP11:
8200 case elfcpp::R_ARM_THM_JUMP8:
8201 // All the relocations above are branches except SBREL31 and PREL31.
8202 return false;
8203
8204 default:
8205 // Be conservative and assume this is a function pointer.
8206 return true;
8207 }
8208 }
8209
8210 template<bool big_endian>
8211 inline bool
8212 Target_arm<big_endian>::Scan::local_reloc_may_be_function_pointer(
8213 Symbol_table*,
8214 Layout*,
8215 Target_arm<big_endian>* target,
8216 Sized_relobj_file<32, big_endian>*,
8217 unsigned int,
8218 Output_section*,
8219 const elfcpp::Rel<32, big_endian>&,
8220 unsigned int r_type,
8221 const elfcpp::Sym<32, big_endian>&)
8222 {
8223 r_type = target->get_real_reloc_type(r_type);
8224 return possible_function_pointer_reloc(r_type);
8225 }
8226
8227 template<bool big_endian>
8228 inline bool
8229 Target_arm<big_endian>::Scan::global_reloc_may_be_function_pointer(
8230 Symbol_table*,
8231 Layout*,
8232 Target_arm<big_endian>* target,
8233 Sized_relobj_file<32, big_endian>*,
8234 unsigned int,
8235 Output_section*,
8236 const elfcpp::Rel<32, big_endian>&,
8237 unsigned int r_type,
8238 Symbol* gsym)
8239 {
8240 // GOT is not a function.
8241 if (strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8242 return false;
8243
8244 r_type = target->get_real_reloc_type(r_type);
8245 return possible_function_pointer_reloc(r_type);
8246 }
8247
8248 // Scan a relocation for a global symbol.
8249
8250 template<bool big_endian>
8251 inline void
8252 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
8253 Layout* layout,
8254 Target_arm* target,
8255 Sized_relobj_file<32, big_endian>* object,
8256 unsigned int data_shndx,
8257 Output_section* output_section,
8258 const elfcpp::Rel<32, big_endian>& reloc,
8259 unsigned int r_type,
8260 Symbol* gsym)
8261 {
8262 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
8263 // section. We check here to avoid creating a dynamic reloc against
8264 // _GLOBAL_OFFSET_TABLE_.
8265 if (!target->has_got_section()
8266 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
8267 target->got_section(symtab, layout);
8268
8269 r_type = get_real_reloc_type(r_type);
8270 switch (r_type)
8271 {
8272 case elfcpp::R_ARM_NONE:
8273 case elfcpp::R_ARM_V4BX:
8274 case elfcpp::R_ARM_GNU_VTENTRY:
8275 case elfcpp::R_ARM_GNU_VTINHERIT:
8276 break;
8277
8278 case elfcpp::R_ARM_ABS32:
8279 case elfcpp::R_ARM_ABS16:
8280 case elfcpp::R_ARM_ABS12:
8281 case elfcpp::R_ARM_THM_ABS5:
8282 case elfcpp::R_ARM_ABS8:
8283 case elfcpp::R_ARM_BASE_ABS:
8284 case elfcpp::R_ARM_MOVW_ABS_NC:
8285 case elfcpp::R_ARM_MOVT_ABS:
8286 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8287 case elfcpp::R_ARM_THM_MOVT_ABS:
8288 case elfcpp::R_ARM_ABS32_NOI:
8289 // Absolute addressing relocations.
8290 {
8291 // Make a PLT entry if necessary.
8292 if (this->symbol_needs_plt_entry(gsym))
8293 {
8294 target->make_plt_entry(symtab, layout, gsym);
8295 // Since this is not a PC-relative relocation, we may be
8296 // taking the address of a function. In that case we need to
8297 // set the entry in the dynamic symbol table to the address of
8298 // the PLT entry.
8299 if (gsym->is_from_dynobj() && !parameters->options().shared())
8300 gsym->set_needs_dynsym_value();
8301 }
8302 // Make a dynamic relocation if necessary.
8303 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8304 {
8305 if (gsym->may_need_copy_reloc())
8306 {
8307 target->copy_reloc(symtab, layout, object,
8308 data_shndx, output_section, gsym, reloc);
8309 }
8310 else if ((r_type == elfcpp::R_ARM_ABS32
8311 || r_type == elfcpp::R_ARM_ABS32_NOI)
8312 && gsym->can_use_relative_reloc(false))
8313 {
8314 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8315 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
8316 output_section, object,
8317 data_shndx, reloc.get_r_offset());
8318 }
8319 else
8320 {
8321 check_non_pic(object, r_type);
8322 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8323 rel_dyn->add_global(gsym, r_type, output_section, object,
8324 data_shndx, reloc.get_r_offset());
8325 }
8326 }
8327 }
8328 break;
8329
8330 case elfcpp::R_ARM_GOTOFF32:
8331 case elfcpp::R_ARM_GOTOFF12:
8332 // We need a GOT section.
8333 target->got_section(symtab, layout);
8334 break;
8335
8336 case elfcpp::R_ARM_REL32:
8337 case elfcpp::R_ARM_LDR_PC_G0:
8338 case elfcpp::R_ARM_SBREL32:
8339 case elfcpp::R_ARM_THM_PC8:
8340 case elfcpp::R_ARM_BASE_PREL:
8341 case elfcpp::R_ARM_MOVW_PREL_NC:
8342 case elfcpp::R_ARM_MOVT_PREL:
8343 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8344 case elfcpp::R_ARM_THM_MOVT_PREL:
8345 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8346 case elfcpp::R_ARM_THM_PC12:
8347 case elfcpp::R_ARM_REL32_NOI:
8348 case elfcpp::R_ARM_ALU_PC_G0_NC:
8349 case elfcpp::R_ARM_ALU_PC_G0:
8350 case elfcpp::R_ARM_ALU_PC_G1_NC:
8351 case elfcpp::R_ARM_ALU_PC_G1:
8352 case elfcpp::R_ARM_ALU_PC_G2:
8353 case elfcpp::R_ARM_LDR_PC_G1:
8354 case elfcpp::R_ARM_LDR_PC_G2:
8355 case elfcpp::R_ARM_LDRS_PC_G0:
8356 case elfcpp::R_ARM_LDRS_PC_G1:
8357 case elfcpp::R_ARM_LDRS_PC_G2:
8358 case elfcpp::R_ARM_LDC_PC_G0:
8359 case elfcpp::R_ARM_LDC_PC_G1:
8360 case elfcpp::R_ARM_LDC_PC_G2:
8361 case elfcpp::R_ARM_ALU_SB_G0_NC:
8362 case elfcpp::R_ARM_ALU_SB_G0:
8363 case elfcpp::R_ARM_ALU_SB_G1_NC:
8364 case elfcpp::R_ARM_ALU_SB_G1:
8365 case elfcpp::R_ARM_ALU_SB_G2:
8366 case elfcpp::R_ARM_LDR_SB_G0:
8367 case elfcpp::R_ARM_LDR_SB_G1:
8368 case elfcpp::R_ARM_LDR_SB_G2:
8369 case elfcpp::R_ARM_LDRS_SB_G0:
8370 case elfcpp::R_ARM_LDRS_SB_G1:
8371 case elfcpp::R_ARM_LDRS_SB_G2:
8372 case elfcpp::R_ARM_LDC_SB_G0:
8373 case elfcpp::R_ARM_LDC_SB_G1:
8374 case elfcpp::R_ARM_LDC_SB_G2:
8375 case elfcpp::R_ARM_MOVW_BREL_NC:
8376 case elfcpp::R_ARM_MOVT_BREL:
8377 case elfcpp::R_ARM_MOVW_BREL:
8378 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8379 case elfcpp::R_ARM_THM_MOVT_BREL:
8380 case elfcpp::R_ARM_THM_MOVW_BREL:
8381 // Relative addressing relocations.
8382 {
8383 // Make a dynamic relocation if necessary.
8384 if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
8385 {
8386 if (target->may_need_copy_reloc(gsym))
8387 {
8388 target->copy_reloc(symtab, layout, object,
8389 data_shndx, output_section, gsym, reloc);
8390 }
8391 else
8392 {
8393 check_non_pic(object, r_type);
8394 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8395 rel_dyn->add_global(gsym, r_type, output_section, object,
8396 data_shndx, reloc.get_r_offset());
8397 }
8398 }
8399 }
8400 break;
8401
8402 case elfcpp::R_ARM_THM_CALL:
8403 case elfcpp::R_ARM_PLT32:
8404 case elfcpp::R_ARM_CALL:
8405 case elfcpp::R_ARM_JUMP24:
8406 case elfcpp::R_ARM_THM_JUMP24:
8407 case elfcpp::R_ARM_SBREL31:
8408 case elfcpp::R_ARM_PREL31:
8409 case elfcpp::R_ARM_THM_JUMP19:
8410 case elfcpp::R_ARM_THM_JUMP6:
8411 case elfcpp::R_ARM_THM_JUMP11:
8412 case elfcpp::R_ARM_THM_JUMP8:
8413 // All the relocation above are branches except for the PREL31 ones.
8414 // A PREL31 relocation can point to a personality function in a shared
8415 // library. In that case we want to use a PLT because we want to
8416 // call the personality routine and the dynamic linkers we care about
8417 // do not support dynamic PREL31 relocations. An REL31 relocation may
8418 // point to a function whose unwinding behaviour is being described but
8419 // we will not mistakenly generate a PLT for that because we should use
8420 // a local section symbol.
8421
8422 // If the symbol is fully resolved, this is just a relative
8423 // local reloc. Otherwise we need a PLT entry.
8424 if (gsym->final_value_is_known())
8425 break;
8426 // If building a shared library, we can also skip the PLT entry
8427 // if the symbol is defined in the output file and is protected
8428 // or hidden.
8429 if (gsym->is_defined()
8430 && !gsym->is_from_dynobj()
8431 && !gsym->is_preemptible())
8432 break;
8433 target->make_plt_entry(symtab, layout, gsym);
8434 break;
8435
8436 case elfcpp::R_ARM_GOT_BREL:
8437 case elfcpp::R_ARM_GOT_ABS:
8438 case elfcpp::R_ARM_GOT_PREL:
8439 {
8440 // The symbol requires a GOT entry.
8441 Arm_output_data_got<big_endian>* got =
8442 target->got_section(symtab, layout);
8443 if (gsym->final_value_is_known())
8444 got->add_global(gsym, GOT_TYPE_STANDARD);
8445 else
8446 {
8447 // If this symbol is not fully resolved, we need to add a
8448 // GOT entry with a dynamic relocation.
8449 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8450 if (gsym->is_from_dynobj()
8451 || gsym->is_undefined()
8452 || gsym->is_preemptible()
8453 || (gsym->visibility() == elfcpp::STV_PROTECTED
8454 && parameters->options().shared()))
8455 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
8456 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
8457 else
8458 {
8459 if (got->add_global(gsym, GOT_TYPE_STANDARD))
8460 rel_dyn->add_global_relative(
8461 gsym, elfcpp::R_ARM_RELATIVE, got,
8462 gsym->got_offset(GOT_TYPE_STANDARD));
8463 }
8464 }
8465 }
8466 break;
8467
8468 case elfcpp::R_ARM_TARGET1:
8469 case elfcpp::R_ARM_TARGET2:
8470 // These should have been mapped to other types already.
8471 // Fall through.
8472 case elfcpp::R_ARM_COPY:
8473 case elfcpp::R_ARM_GLOB_DAT:
8474 case elfcpp::R_ARM_JUMP_SLOT:
8475 case elfcpp::R_ARM_RELATIVE:
8476 // These are relocations which should only be seen by the
8477 // dynamic linker, and should never be seen here.
8478 gold_error(_("%s: unexpected reloc %u in object file"),
8479 object->name().c_str(), r_type);
8480 break;
8481
8482 // These are initial tls relocs, which are expected when
8483 // linking.
8484 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8485 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8486 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8487 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8488 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8489 {
8490 const bool is_final = gsym->final_value_is_known();
8491 const tls::Tls_optimization optimized_type
8492 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8493 switch (r_type)
8494 {
8495 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8496 if (optimized_type == tls::TLSOPT_NONE)
8497 {
8498 // Create a pair of GOT entries for the module index and
8499 // dtv-relative offset.
8500 Arm_output_data_got<big_endian>* got
8501 = target->got_section(symtab, layout);
8502 if (!parameters->doing_static_link())
8503 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
8504 target->rel_dyn_section(layout),
8505 elfcpp::R_ARM_TLS_DTPMOD32,
8506 elfcpp::R_ARM_TLS_DTPOFF32);
8507 else
8508 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
8509 }
8510 else
8511 // FIXME: TLS optimization not supported yet.
8512 gold_unreachable();
8513 break;
8514
8515 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8516 if (optimized_type == tls::TLSOPT_NONE)
8517 {
8518 // Create a GOT entry for the module index.
8519 target->got_mod_index_entry(symtab, layout, object);
8520 }
8521 else
8522 // FIXME: TLS optimization not supported yet.
8523 gold_unreachable();
8524 break;
8525
8526 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8527 break;
8528
8529 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8530 layout->set_has_static_tls();
8531 if (optimized_type == tls::TLSOPT_NONE)
8532 {
8533 // Create a GOT entry for the tp-relative offset.
8534 Arm_output_data_got<big_endian>* got
8535 = target->got_section(symtab, layout);
8536 if (!parameters->doing_static_link())
8537 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
8538 target->rel_dyn_section(layout),
8539 elfcpp::R_ARM_TLS_TPOFF32);
8540 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
8541 {
8542 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
8543 unsigned int got_offset =
8544 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
8545 got->add_static_reloc(got_offset,
8546 elfcpp::R_ARM_TLS_TPOFF32, gsym);
8547 }
8548 }
8549 else
8550 // FIXME: TLS optimization not supported yet.
8551 gold_unreachable();
8552 break;
8553
8554 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8555 layout->set_has_static_tls();
8556 if (parameters->options().shared())
8557 {
8558 // We need to create a dynamic relocation.
8559 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
8560 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
8561 output_section, object,
8562 data_shndx, reloc.get_r_offset());
8563 }
8564 break;
8565
8566 default:
8567 gold_unreachable();
8568 }
8569 }
8570 break;
8571
8572 case elfcpp::R_ARM_PC24:
8573 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
8574 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
8575 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
8576 default:
8577 unsupported_reloc_global(object, r_type, gsym);
8578 break;
8579 }
8580 }
8581
8582 // Process relocations for gc.
8583
8584 template<bool big_endian>
8585 void
8586 Target_arm<big_endian>::gc_process_relocs(
8587 Symbol_table* symtab,
8588 Layout* layout,
8589 Sized_relobj_file<32, big_endian>* object,
8590 unsigned int data_shndx,
8591 unsigned int,
8592 const unsigned char* prelocs,
8593 size_t reloc_count,
8594 Output_section* output_section,
8595 bool needs_special_offset_handling,
8596 size_t local_symbol_count,
8597 const unsigned char* plocal_symbols)
8598 {
8599 typedef Target_arm<big_endian> Arm;
8600 typedef typename Target_arm<big_endian>::Scan Scan;
8601
8602 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan,
8603 typename Target_arm::Relocatable_size_for_reloc>(
8604 symtab,
8605 layout,
8606 this,
8607 object,
8608 data_shndx,
8609 prelocs,
8610 reloc_count,
8611 output_section,
8612 needs_special_offset_handling,
8613 local_symbol_count,
8614 plocal_symbols);
8615 }
8616
8617 // Scan relocations for a section.
8618
8619 template<bool big_endian>
8620 void
8621 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
8622 Layout* layout,
8623 Sized_relobj_file<32, big_endian>* object,
8624 unsigned int data_shndx,
8625 unsigned int sh_type,
8626 const unsigned char* prelocs,
8627 size_t reloc_count,
8628 Output_section* output_section,
8629 bool needs_special_offset_handling,
8630 size_t local_symbol_count,
8631 const unsigned char* plocal_symbols)
8632 {
8633 typedef typename Target_arm<big_endian>::Scan Scan;
8634 if (sh_type == elfcpp::SHT_RELA)
8635 {
8636 gold_error(_("%s: unsupported RELA reloc section"),
8637 object->name().c_str());
8638 return;
8639 }
8640
8641 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
8642 symtab,
8643 layout,
8644 this,
8645 object,
8646 data_shndx,
8647 prelocs,
8648 reloc_count,
8649 output_section,
8650 needs_special_offset_handling,
8651 local_symbol_count,
8652 plocal_symbols);
8653 }
8654
8655 // Finalize the sections.
8656
8657 template<bool big_endian>
8658 void
8659 Target_arm<big_endian>::do_finalize_sections(
8660 Layout* layout,
8661 const Input_objects* input_objects,
8662 Symbol_table*)
8663 {
8664 bool merged_any_attributes = false;
8665 // Merge processor-specific flags.
8666 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
8667 p != input_objects->relobj_end();
8668 ++p)
8669 {
8670 Arm_relobj<big_endian>* arm_relobj =
8671 Arm_relobj<big_endian>::as_arm_relobj(*p);
8672 if (arm_relobj->merge_flags_and_attributes())
8673 {
8674 this->merge_processor_specific_flags(
8675 arm_relobj->name(),
8676 arm_relobj->processor_specific_flags());
8677 this->merge_object_attributes(arm_relobj->name().c_str(),
8678 arm_relobj->attributes_section_data());
8679 merged_any_attributes = true;
8680 }
8681 }
8682
8683 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8684 p != input_objects->dynobj_end();
8685 ++p)
8686 {
8687 Arm_dynobj<big_endian>* arm_dynobj =
8688 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8689 this->merge_processor_specific_flags(
8690 arm_dynobj->name(),
8691 arm_dynobj->processor_specific_flags());
8692 this->merge_object_attributes(arm_dynobj->name().c_str(),
8693 arm_dynobj->attributes_section_data());
8694 merged_any_attributes = true;
8695 }
8696
8697 // Create an empty uninitialized attribute section if we still don't have it
8698 // at this moment. This happens if there is no attributes sections in all
8699 // inputs.
8700 if (this->attributes_section_data_ == NULL)
8701 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
8702
8703 const Object_attribute* cpu_arch_attr =
8704 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8705 // Check if we need to use Cortex-A8 workaround.
8706 if (parameters->options().user_set_fix_cortex_a8())
8707 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8708 else
8709 {
8710 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8711 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8712 // profile.
8713 const Object_attribute* cpu_arch_profile_attr =
8714 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8715 this->fix_cortex_a8_ =
8716 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8717 && (cpu_arch_profile_attr->int_value() == 'A'
8718 || cpu_arch_profile_attr->int_value() == 0));
8719 }
8720
8721 // Check if we can use V4BX interworking.
8722 // The V4BX interworking stub contains BX instruction,
8723 // which is not specified for some profiles.
8724 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8725 && !this->may_use_v4t_interworking())
8726 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8727 "the target profile does not support BX instruction"));
8728
8729 // Fill in some more dynamic tags.
8730 const Reloc_section* rel_plt = (this->plt_ == NULL
8731 ? NULL
8732 : this->plt_->rel_plt());
8733 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8734 this->rel_dyn_, true, false);
8735
8736 // Emit any relocs we saved in an attempt to avoid generating COPY
8737 // relocs.
8738 if (this->copy_relocs_.any_saved_relocs())
8739 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8740
8741 // Handle the .ARM.exidx section.
8742 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8743
8744 if (!parameters->options().relocatable())
8745 {
8746 if (exidx_section != NULL
8747 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX)
8748 {
8749 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8750 // the .ARM.exidx section.
8751 if (!layout->script_options()->saw_phdrs_clause())
8752 {
8753 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0,
8754 0)
8755 == NULL);
8756 Output_segment* exidx_segment =
8757 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8758 exidx_segment->add_output_section_to_nonload(exidx_section,
8759 elfcpp::PF_R);
8760 }
8761 }
8762 }
8763
8764 // Create an .ARM.attributes section if we have merged any attributes
8765 // from inputs.
8766 if (merged_any_attributes)
8767 {
8768 Output_attributes_section_data* attributes_section =
8769 new Output_attributes_section_data(*this->attributes_section_data_);
8770 layout->add_output_section_data(".ARM.attributes",
8771 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8772 attributes_section, ORDER_INVALID,
8773 false);
8774 }
8775
8776 // Fix up links in section EXIDX headers.
8777 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
8778 p != layout->section_list().end();
8779 ++p)
8780 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
8781 {
8782 Arm_output_section<big_endian>* os =
8783 Arm_output_section<big_endian>::as_arm_output_section(*p);
8784 os->set_exidx_section_link();
8785 }
8786 }
8787
8788 // Return whether a direct absolute static relocation needs to be applied.
8789 // In cases where Scan::local() or Scan::global() has created
8790 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8791 // of the relocation is carried in the data, and we must not
8792 // apply the static relocation.
8793
8794 template<bool big_endian>
8795 inline bool
8796 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8797 const Sized_symbol<32>* gsym,
8798 unsigned int r_type,
8799 bool is_32bit,
8800 Output_section* output_section)
8801 {
8802 // If the output section is not allocated, then we didn't call
8803 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8804 // the reloc here.
8805 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8806 return true;
8807
8808 int ref_flags = Scan::get_reference_flags(r_type);
8809
8810 // For local symbols, we will have created a non-RELATIVE dynamic
8811 // relocation only if (a) the output is position independent,
8812 // (b) the relocation is absolute (not pc- or segment-relative), and
8813 // (c) the relocation is not 32 bits wide.
8814 if (gsym == NULL)
8815 return !(parameters->options().output_is_position_independent()
8816 && (ref_flags & Symbol::ABSOLUTE_REF)
8817 && !is_32bit);
8818
8819 // For global symbols, we use the same helper routines used in the
8820 // scan pass. If we did not create a dynamic relocation, or if we
8821 // created a RELATIVE dynamic relocation, we should apply the static
8822 // relocation.
8823 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8824 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8825 && gsym->can_use_relative_reloc(ref_flags
8826 & Symbol::FUNCTION_CALL);
8827 return !has_dyn || is_rel;
8828 }
8829
8830 // Perform a relocation.
8831
8832 template<bool big_endian>
8833 inline bool
8834 Target_arm<big_endian>::Relocate::relocate(
8835 const Relocate_info<32, big_endian>* relinfo,
8836 Target_arm* target,
8837 Output_section* output_section,
8838 size_t relnum,
8839 const elfcpp::Rel<32, big_endian>& rel,
8840 unsigned int r_type,
8841 const Sized_symbol<32>* gsym,
8842 const Symbol_value<32>* psymval,
8843 unsigned char* view,
8844 Arm_address address,
8845 section_size_type view_size)
8846 {
8847 if (view == NULL)
8848 return true;
8849
8850 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8851
8852 r_type = get_real_reloc_type(r_type);
8853 const Arm_reloc_property* reloc_property =
8854 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8855 if (reloc_property == NULL)
8856 {
8857 std::string reloc_name =
8858 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8859 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8860 _("cannot relocate %s in object file"),
8861 reloc_name.c_str());
8862 return true;
8863 }
8864
8865 const Arm_relobj<big_endian>* object =
8866 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8867
8868 // If the final branch target of a relocation is THUMB instruction, this
8869 // is 1. Otherwise it is 0.
8870 Arm_address thumb_bit = 0;
8871 Symbol_value<32> symval;
8872 bool is_weakly_undefined_without_plt = false;
8873 bool have_got_offset = false;
8874 unsigned int got_offset = 0;
8875
8876 // If the relocation uses the GOT entry of a symbol instead of the symbol
8877 // itself, we don't care about whether the symbol is defined or what kind
8878 // of symbol it is.
8879 if (reloc_property->uses_got_entry())
8880 {
8881 // Get the GOT offset.
8882 // The GOT pointer points to the end of the GOT section.
8883 // We need to subtract the size of the GOT section to get
8884 // the actual offset to use in the relocation.
8885 // TODO: We should move GOT offset computing code in TLS relocations
8886 // to here.
8887 switch (r_type)
8888 {
8889 case elfcpp::R_ARM_GOT_BREL:
8890 case elfcpp::R_ARM_GOT_PREL:
8891 if (gsym != NULL)
8892 {
8893 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8894 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8895 - target->got_size());
8896 }
8897 else
8898 {
8899 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8900 gold_assert(object->local_has_got_offset(r_sym,
8901 GOT_TYPE_STANDARD));
8902 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8903 - target->got_size());
8904 }
8905 have_got_offset = true;
8906 break;
8907
8908 default:
8909 break;
8910 }
8911 }
8912 else if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8913 {
8914 if (gsym != NULL)
8915 {
8916 // This is a global symbol. Determine if we use PLT and if the
8917 // final target is THUMB.
8918 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
8919 {
8920 // This uses a PLT, change the symbol value.
8921 symval.set_output_value(target->plt_section()->address()
8922 + gsym->plt_offset());
8923 psymval = &symval;
8924 }
8925 else if (gsym->is_weak_undefined())
8926 {
8927 // This is a weakly undefined symbol and we do not use PLT
8928 // for this relocation. A branch targeting this symbol will
8929 // be converted into an NOP.
8930 is_weakly_undefined_without_plt = true;
8931 }
8932 else if (gsym->is_undefined() && reloc_property->uses_symbol())
8933 {
8934 // This relocation uses the symbol value but the symbol is
8935 // undefined. Exit early and have the caller reporting an
8936 // error.
8937 return true;
8938 }
8939 else
8940 {
8941 // Set thumb bit if symbol:
8942 // -Has type STT_ARM_TFUNC or
8943 // -Has type STT_FUNC, is defined and with LSB in value set.
8944 thumb_bit =
8945 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8946 || (gsym->type() == elfcpp::STT_FUNC
8947 && !gsym->is_undefined()
8948 && ((psymval->value(object, 0) & 1) != 0)))
8949 ? 1
8950 : 0);
8951 }
8952 }
8953 else
8954 {
8955 // This is a local symbol. Determine if the final target is THUMB.
8956 // We saved this information when all the local symbols were read.
8957 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8958 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8959 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8960 }
8961 }
8962 else
8963 {
8964 // This is a fake relocation synthesized for a stub. It does not have
8965 // a real symbol. We just look at the LSB of the symbol value to
8966 // determine if the target is THUMB or not.
8967 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8968 }
8969
8970 // Strip LSB if this points to a THUMB target.
8971 if (thumb_bit != 0
8972 && reloc_property->uses_thumb_bit()
8973 && ((psymval->value(object, 0) & 1) != 0))
8974 {
8975 Arm_address stripped_value =
8976 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8977 symval.set_output_value(stripped_value);
8978 psymval = &symval;
8979 }
8980
8981 // To look up relocation stubs, we need to pass the symbol table index of
8982 // a local symbol.
8983 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8984
8985 // Get the addressing origin of the output segment defining the
8986 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8987 Arm_address sym_origin = 0;
8988 if (reloc_property->uses_symbol_base())
8989 {
8990 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8991 // R_ARM_BASE_ABS with the NULL symbol will give the
8992 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8993 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8994 sym_origin = target->got_plt_section()->address();
8995 else if (gsym == NULL)
8996 sym_origin = 0;
8997 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8998 sym_origin = gsym->output_segment()->vaddr();
8999 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
9000 sym_origin = gsym->output_data()->address();
9001
9002 // TODO: Assumes the segment base to be zero for the global symbols
9003 // till the proper support for the segment-base-relative addressing
9004 // will be implemented. This is consistent with GNU ld.
9005 }
9006
9007 // For relative addressing relocation, find out the relative address base.
9008 Arm_address relative_address_base = 0;
9009 switch(reloc_property->relative_address_base())
9010 {
9011 case Arm_reloc_property::RAB_NONE:
9012 // Relocations with relative address bases RAB_TLS and RAB_tp are
9013 // handled by relocate_tls. So we do not need to do anything here.
9014 case Arm_reloc_property::RAB_TLS:
9015 case Arm_reloc_property::RAB_tp:
9016 break;
9017 case Arm_reloc_property::RAB_B_S:
9018 relative_address_base = sym_origin;
9019 break;
9020 case Arm_reloc_property::RAB_GOT_ORG:
9021 relative_address_base = target->got_plt_section()->address();
9022 break;
9023 case Arm_reloc_property::RAB_P:
9024 relative_address_base = address;
9025 break;
9026 case Arm_reloc_property::RAB_Pa:
9027 relative_address_base = address & 0xfffffffcU;
9028 break;
9029 default:
9030 gold_unreachable();
9031 }
9032
9033 typename Arm_relocate_functions::Status reloc_status =
9034 Arm_relocate_functions::STATUS_OKAY;
9035 bool check_overflow = reloc_property->checks_overflow();
9036 switch (r_type)
9037 {
9038 case elfcpp::R_ARM_NONE:
9039 break;
9040
9041 case elfcpp::R_ARM_ABS8:
9042 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9043 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
9044 break;
9045
9046 case elfcpp::R_ARM_ABS12:
9047 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9048 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
9049 break;
9050
9051 case elfcpp::R_ARM_ABS16:
9052 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9053 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
9054 break;
9055
9056 case elfcpp::R_ARM_ABS32:
9057 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9058 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9059 thumb_bit);
9060 break;
9061
9062 case elfcpp::R_ARM_ABS32_NOI:
9063 if (should_apply_static_reloc(gsym, r_type, true, output_section))
9064 // No thumb bit for this relocation: (S + A)
9065 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
9066 0);
9067 break;
9068
9069 case elfcpp::R_ARM_MOVW_ABS_NC:
9070 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9071 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
9072 0, thumb_bit,
9073 check_overflow);
9074 break;
9075
9076 case elfcpp::R_ARM_MOVT_ABS:
9077 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9078 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
9079 break;
9080
9081 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9082 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9083 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
9084 0, thumb_bit, false);
9085 break;
9086
9087 case elfcpp::R_ARM_THM_MOVT_ABS:
9088 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9089 reloc_status = Arm_relocate_functions::thm_movt(view, object,
9090 psymval, 0);
9091 break;
9092
9093 case elfcpp::R_ARM_MOVW_PREL_NC:
9094 case elfcpp::R_ARM_MOVW_BREL_NC:
9095 case elfcpp::R_ARM_MOVW_BREL:
9096 reloc_status =
9097 Arm_relocate_functions::movw(view, object, psymval,
9098 relative_address_base, thumb_bit,
9099 check_overflow);
9100 break;
9101
9102 case elfcpp::R_ARM_MOVT_PREL:
9103 case elfcpp::R_ARM_MOVT_BREL:
9104 reloc_status =
9105 Arm_relocate_functions::movt(view, object, psymval,
9106 relative_address_base);
9107 break;
9108
9109 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9110 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9111 case elfcpp::R_ARM_THM_MOVW_BREL:
9112 reloc_status =
9113 Arm_relocate_functions::thm_movw(view, object, psymval,
9114 relative_address_base,
9115 thumb_bit, check_overflow);
9116 break;
9117
9118 case elfcpp::R_ARM_THM_MOVT_PREL:
9119 case elfcpp::R_ARM_THM_MOVT_BREL:
9120 reloc_status =
9121 Arm_relocate_functions::thm_movt(view, object, psymval,
9122 relative_address_base);
9123 break;
9124
9125 case elfcpp::R_ARM_REL32:
9126 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9127 address, thumb_bit);
9128 break;
9129
9130 case elfcpp::R_ARM_THM_ABS5:
9131 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9132 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
9133 break;
9134
9135 // Thumb long branches.
9136 case elfcpp::R_ARM_THM_CALL:
9137 case elfcpp::R_ARM_THM_XPC22:
9138 case elfcpp::R_ARM_THM_JUMP24:
9139 reloc_status =
9140 Arm_relocate_functions::thumb_branch_common(
9141 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9142 thumb_bit, is_weakly_undefined_without_plt);
9143 break;
9144
9145 case elfcpp::R_ARM_GOTOFF32:
9146 {
9147 Arm_address got_origin;
9148 got_origin = target->got_plt_section()->address();
9149 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
9150 got_origin, thumb_bit);
9151 }
9152 break;
9153
9154 case elfcpp::R_ARM_BASE_PREL:
9155 gold_assert(gsym != NULL);
9156 reloc_status =
9157 Arm_relocate_functions::base_prel(view, sym_origin, address);
9158 break;
9159
9160 case elfcpp::R_ARM_BASE_ABS:
9161 if (should_apply_static_reloc(gsym, r_type, false, output_section))
9162 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
9163 break;
9164
9165 case elfcpp::R_ARM_GOT_BREL:
9166 gold_assert(have_got_offset);
9167 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
9168 break;
9169
9170 case elfcpp::R_ARM_GOT_PREL:
9171 gold_assert(have_got_offset);
9172 // Get the address origin for GOT PLT, which is allocated right
9173 // after the GOT section, to calculate an absolute address of
9174 // the symbol GOT entry (got_origin + got_offset).
9175 Arm_address got_origin;
9176 got_origin = target->got_plt_section()->address();
9177 reloc_status = Arm_relocate_functions::got_prel(view,
9178 got_origin + got_offset,
9179 address);
9180 break;
9181
9182 case elfcpp::R_ARM_PLT32:
9183 case elfcpp::R_ARM_CALL:
9184 case elfcpp::R_ARM_JUMP24:
9185 case elfcpp::R_ARM_XPC25:
9186 gold_assert(gsym == NULL
9187 || gsym->has_plt_offset()
9188 || gsym->final_value_is_known()
9189 || (gsym->is_defined()
9190 && !gsym->is_from_dynobj()
9191 && !gsym->is_preemptible()));
9192 reloc_status =
9193 Arm_relocate_functions::arm_branch_common(
9194 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
9195 thumb_bit, is_weakly_undefined_without_plt);
9196 break;
9197
9198 case elfcpp::R_ARM_THM_JUMP19:
9199 reloc_status =
9200 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
9201 thumb_bit);
9202 break;
9203
9204 case elfcpp::R_ARM_THM_JUMP6:
9205 reloc_status =
9206 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
9207 break;
9208
9209 case elfcpp::R_ARM_THM_JUMP8:
9210 reloc_status =
9211 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
9212 break;
9213
9214 case elfcpp::R_ARM_THM_JUMP11:
9215 reloc_status =
9216 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
9217 break;
9218
9219 case elfcpp::R_ARM_PREL31:
9220 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
9221 address, thumb_bit);
9222 break;
9223
9224 case elfcpp::R_ARM_V4BX:
9225 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
9226 {
9227 const bool is_v4bx_interworking =
9228 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
9229 reloc_status =
9230 Arm_relocate_functions::v4bx(relinfo, view, object, address,
9231 is_v4bx_interworking);
9232 }
9233 break;
9234
9235 case elfcpp::R_ARM_THM_PC8:
9236 reloc_status =
9237 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
9238 break;
9239
9240 case elfcpp::R_ARM_THM_PC12:
9241 reloc_status =
9242 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
9243 break;
9244
9245 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9246 reloc_status =
9247 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
9248 thumb_bit);
9249 break;
9250
9251 case elfcpp::R_ARM_ALU_PC_G0_NC:
9252 case elfcpp::R_ARM_ALU_PC_G0:
9253 case elfcpp::R_ARM_ALU_PC_G1_NC:
9254 case elfcpp::R_ARM_ALU_PC_G1:
9255 case elfcpp::R_ARM_ALU_PC_G2:
9256 case elfcpp::R_ARM_ALU_SB_G0_NC:
9257 case elfcpp::R_ARM_ALU_SB_G0:
9258 case elfcpp::R_ARM_ALU_SB_G1_NC:
9259 case elfcpp::R_ARM_ALU_SB_G1:
9260 case elfcpp::R_ARM_ALU_SB_G2:
9261 reloc_status =
9262 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
9263 reloc_property->group_index(),
9264 relative_address_base,
9265 thumb_bit, check_overflow);
9266 break;
9267
9268 case elfcpp::R_ARM_LDR_PC_G0:
9269 case elfcpp::R_ARM_LDR_PC_G1:
9270 case elfcpp::R_ARM_LDR_PC_G2:
9271 case elfcpp::R_ARM_LDR_SB_G0:
9272 case elfcpp::R_ARM_LDR_SB_G1:
9273 case elfcpp::R_ARM_LDR_SB_G2:
9274 reloc_status =
9275 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
9276 reloc_property->group_index(),
9277 relative_address_base);
9278 break;
9279
9280 case elfcpp::R_ARM_LDRS_PC_G0:
9281 case elfcpp::R_ARM_LDRS_PC_G1:
9282 case elfcpp::R_ARM_LDRS_PC_G2:
9283 case elfcpp::R_ARM_LDRS_SB_G0:
9284 case elfcpp::R_ARM_LDRS_SB_G1:
9285 case elfcpp::R_ARM_LDRS_SB_G2:
9286 reloc_status =
9287 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
9288 reloc_property->group_index(),
9289 relative_address_base);
9290 break;
9291
9292 case elfcpp::R_ARM_LDC_PC_G0:
9293 case elfcpp::R_ARM_LDC_PC_G1:
9294 case elfcpp::R_ARM_LDC_PC_G2:
9295 case elfcpp::R_ARM_LDC_SB_G0:
9296 case elfcpp::R_ARM_LDC_SB_G1:
9297 case elfcpp::R_ARM_LDC_SB_G2:
9298 reloc_status =
9299 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
9300 reloc_property->group_index(),
9301 relative_address_base);
9302 break;
9303
9304 // These are initial tls relocs, which are expected when
9305 // linking.
9306 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9307 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9308 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9309 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9310 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9311 reloc_status =
9312 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
9313 view, address, view_size);
9314 break;
9315
9316 // The known and unknown unsupported and/or deprecated relocations.
9317 case elfcpp::R_ARM_PC24:
9318 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
9319 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
9320 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
9321 default:
9322 // Just silently leave the method. We should get an appropriate error
9323 // message in the scan methods.
9324 break;
9325 }
9326
9327 // Report any errors.
9328 switch (reloc_status)
9329 {
9330 case Arm_relocate_functions::STATUS_OKAY:
9331 break;
9332 case Arm_relocate_functions::STATUS_OVERFLOW:
9333 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9334 _("relocation overflow in %s"),
9335 reloc_property->name().c_str());
9336 break;
9337 case Arm_relocate_functions::STATUS_BAD_RELOC:
9338 gold_error_at_location(
9339 relinfo,
9340 relnum,
9341 rel.get_r_offset(),
9342 _("unexpected opcode while processing relocation %s"),
9343 reloc_property->name().c_str());
9344 break;
9345 default:
9346 gold_unreachable();
9347 }
9348
9349 return true;
9350 }
9351
9352 // Perform a TLS relocation.
9353
9354 template<bool big_endian>
9355 inline typename Arm_relocate_functions<big_endian>::Status
9356 Target_arm<big_endian>::Relocate::relocate_tls(
9357 const Relocate_info<32, big_endian>* relinfo,
9358 Target_arm<big_endian>* target,
9359 size_t relnum,
9360 const elfcpp::Rel<32, big_endian>& rel,
9361 unsigned int r_type,
9362 const Sized_symbol<32>* gsym,
9363 const Symbol_value<32>* psymval,
9364 unsigned char* view,
9365 elfcpp::Elf_types<32>::Elf_Addr address,
9366 section_size_type /*view_size*/ )
9367 {
9368 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
9369 typedef Relocate_functions<32, big_endian> RelocFuncs;
9370 Output_segment* tls_segment = relinfo->layout->tls_segment();
9371
9372 const Sized_relobj_file<32, big_endian>* object = relinfo->object;
9373
9374 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
9375
9376 const bool is_final = (gsym == NULL
9377 ? !parameters->options().shared()
9378 : gsym->final_value_is_known());
9379 const tls::Tls_optimization optimized_type
9380 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
9381 switch (r_type)
9382 {
9383 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
9384 {
9385 unsigned int got_type = GOT_TYPE_TLS_PAIR;
9386 unsigned int got_offset;
9387 if (gsym != NULL)
9388 {
9389 gold_assert(gsym->has_got_offset(got_type));
9390 got_offset = gsym->got_offset(got_type) - target->got_size();
9391 }
9392 else
9393 {
9394 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9395 gold_assert(object->local_has_got_offset(r_sym, got_type));
9396 got_offset = (object->local_got_offset(r_sym, got_type)
9397 - target->got_size());
9398 }
9399 if (optimized_type == tls::TLSOPT_NONE)
9400 {
9401 Arm_address got_entry =
9402 target->got_plt_section()->address() + got_offset;
9403
9404 // Relocate the field with the PC relative offset of the pair of
9405 // GOT entries.
9406 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9407 return ArmRelocFuncs::STATUS_OKAY;
9408 }
9409 }
9410 break;
9411
9412 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
9413 if (optimized_type == tls::TLSOPT_NONE)
9414 {
9415 // Relocate the field with the offset of the GOT entry for
9416 // the module index.
9417 unsigned int got_offset;
9418 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
9419 - target->got_size());
9420 Arm_address got_entry =
9421 target->got_plt_section()->address() + got_offset;
9422
9423 // Relocate the field with the PC relative offset of the pair of
9424 // GOT entries.
9425 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9426 return ArmRelocFuncs::STATUS_OKAY;
9427 }
9428 break;
9429
9430 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
9431 RelocFuncs::rel32_unaligned(view, value);
9432 return ArmRelocFuncs::STATUS_OKAY;
9433
9434 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
9435 if (optimized_type == tls::TLSOPT_NONE)
9436 {
9437 // Relocate the field with the offset of the GOT entry for
9438 // the tp-relative offset of the symbol.
9439 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
9440 unsigned int got_offset;
9441 if (gsym != NULL)
9442 {
9443 gold_assert(gsym->has_got_offset(got_type));
9444 got_offset = gsym->got_offset(got_type);
9445 }
9446 else
9447 {
9448 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
9449 gold_assert(object->local_has_got_offset(r_sym, got_type));
9450 got_offset = object->local_got_offset(r_sym, got_type);
9451 }
9452
9453 // All GOT offsets are relative to the end of the GOT.
9454 got_offset -= target->got_size();
9455
9456 Arm_address got_entry =
9457 target->got_plt_section()->address() + got_offset;
9458
9459 // Relocate the field with the PC relative offset of the GOT entry.
9460 RelocFuncs::pcrel32_unaligned(view, got_entry, address);
9461 return ArmRelocFuncs::STATUS_OKAY;
9462 }
9463 break;
9464
9465 case elfcpp::R_ARM_TLS_LE32: // Local-exec
9466 // If we're creating a shared library, a dynamic relocation will
9467 // have been created for this location, so do not apply it now.
9468 if (!parameters->options().shared())
9469 {
9470 gold_assert(tls_segment != NULL);
9471
9472 // $tp points to the TCB, which is followed by the TLS, so we
9473 // need to add TCB size to the offset.
9474 Arm_address aligned_tcb_size =
9475 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
9476 RelocFuncs::rel32_unaligned(view, value + aligned_tcb_size);
9477
9478 }
9479 return ArmRelocFuncs::STATUS_OKAY;
9480
9481 default:
9482 gold_unreachable();
9483 }
9484
9485 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
9486 _("unsupported reloc %u"),
9487 r_type);
9488 return ArmRelocFuncs::STATUS_BAD_RELOC;
9489 }
9490
9491 // Relocate section data.
9492
9493 template<bool big_endian>
9494 void
9495 Target_arm<big_endian>::relocate_section(
9496 const Relocate_info<32, big_endian>* relinfo,
9497 unsigned int sh_type,
9498 const unsigned char* prelocs,
9499 size_t reloc_count,
9500 Output_section* output_section,
9501 bool needs_special_offset_handling,
9502 unsigned char* view,
9503 Arm_address address,
9504 section_size_type view_size,
9505 const Reloc_symbol_changes* reloc_symbol_changes)
9506 {
9507 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
9508 gold_assert(sh_type == elfcpp::SHT_REL);
9509
9510 // See if we are relocating a relaxed input section. If so, the view
9511 // covers the whole output section and we need to adjust accordingly.
9512 if (needs_special_offset_handling)
9513 {
9514 const Output_relaxed_input_section* poris =
9515 output_section->find_relaxed_input_section(relinfo->object,
9516 relinfo->data_shndx);
9517 if (poris != NULL)
9518 {
9519 Arm_address section_address = poris->address();
9520 section_size_type section_size = poris->data_size();
9521
9522 gold_assert((section_address >= address)
9523 && ((section_address + section_size)
9524 <= (address + view_size)));
9525
9526 off_t offset = section_address - address;
9527 view += offset;
9528 address += offset;
9529 view_size = section_size;
9530 }
9531 }
9532
9533 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
9534 Arm_relocate, gold::Default_comdat_behavior>(
9535 relinfo,
9536 this,
9537 prelocs,
9538 reloc_count,
9539 output_section,
9540 needs_special_offset_handling,
9541 view,
9542 address,
9543 view_size,
9544 reloc_symbol_changes);
9545 }
9546
9547 // Return the size of a relocation while scanning during a relocatable
9548 // link.
9549
9550 template<bool big_endian>
9551 unsigned int
9552 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
9553 unsigned int r_type,
9554 Relobj* object)
9555 {
9556 r_type = get_real_reloc_type(r_type);
9557 const Arm_reloc_property* arp =
9558 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9559 if (arp != NULL)
9560 return arp->size();
9561 else
9562 {
9563 std::string reloc_name =
9564 arm_reloc_property_table->reloc_name_in_error_message(r_type);
9565 gold_error(_("%s: unexpected %s in object file"),
9566 object->name().c_str(), reloc_name.c_str());
9567 return 0;
9568 }
9569 }
9570
9571 // Scan the relocs during a relocatable link.
9572
9573 template<bool big_endian>
9574 void
9575 Target_arm<big_endian>::scan_relocatable_relocs(
9576 Symbol_table* symtab,
9577 Layout* layout,
9578 Sized_relobj_file<32, big_endian>* object,
9579 unsigned int data_shndx,
9580 unsigned int sh_type,
9581 const unsigned char* prelocs,
9582 size_t reloc_count,
9583 Output_section* output_section,
9584 bool needs_special_offset_handling,
9585 size_t local_symbol_count,
9586 const unsigned char* plocal_symbols,
9587 Relocatable_relocs* rr)
9588 {
9589 gold_assert(sh_type == elfcpp::SHT_REL);
9590
9591 typedef Arm_scan_relocatable_relocs<big_endian, elfcpp::SHT_REL,
9592 Relocatable_size_for_reloc> Scan_relocatable_relocs;
9593
9594 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
9595 Scan_relocatable_relocs>(
9596 symtab,
9597 layout,
9598 object,
9599 data_shndx,
9600 prelocs,
9601 reloc_count,
9602 output_section,
9603 needs_special_offset_handling,
9604 local_symbol_count,
9605 plocal_symbols,
9606 rr);
9607 }
9608
9609 // Emit relocations for a section.
9610
9611 template<bool big_endian>
9612 void
9613 Target_arm<big_endian>::relocate_relocs(
9614 const Relocate_info<32, big_endian>* relinfo,
9615 unsigned int sh_type,
9616 const unsigned char* prelocs,
9617 size_t reloc_count,
9618 Output_section* output_section,
9619 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9620 const Relocatable_relocs* rr,
9621 unsigned char* view,
9622 Arm_address view_address,
9623 section_size_type view_size,
9624 unsigned char* reloc_view,
9625 section_size_type reloc_view_size)
9626 {
9627 gold_assert(sh_type == elfcpp::SHT_REL);
9628
9629 gold::relocate_relocs<32, big_endian, elfcpp::SHT_REL>(
9630 relinfo,
9631 prelocs,
9632 reloc_count,
9633 output_section,
9634 offset_in_output_section,
9635 rr,
9636 view,
9637 view_address,
9638 view_size,
9639 reloc_view,
9640 reloc_view_size);
9641 }
9642
9643 // Perform target-specific processing in a relocatable link. This is
9644 // only used if we use the relocation strategy RELOC_SPECIAL.
9645
9646 template<bool big_endian>
9647 void
9648 Target_arm<big_endian>::relocate_special_relocatable(
9649 const Relocate_info<32, big_endian>* relinfo,
9650 unsigned int sh_type,
9651 const unsigned char* preloc_in,
9652 size_t relnum,
9653 Output_section* output_section,
9654 typename elfcpp::Elf_types<32>::Elf_Off offset_in_output_section,
9655 unsigned char* view,
9656 elfcpp::Elf_types<32>::Elf_Addr view_address,
9657 section_size_type,
9658 unsigned char* preloc_out)
9659 {
9660 // We can only handle REL type relocation sections.
9661 gold_assert(sh_type == elfcpp::SHT_REL);
9662
9663 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc Reltype;
9664 typedef typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc_write
9665 Reltype_write;
9666 const Arm_address invalid_address = static_cast<Arm_address>(0) - 1;
9667
9668 const Arm_relobj<big_endian>* object =
9669 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9670 const unsigned int local_count = object->local_symbol_count();
9671
9672 Reltype reloc(preloc_in);
9673 Reltype_write reloc_write(preloc_out);
9674
9675 elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
9676 const unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
9677 const unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
9678
9679 const Arm_reloc_property* arp =
9680 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
9681 gold_assert(arp != NULL);
9682
9683 // Get the new symbol index.
9684 // We only use RELOC_SPECIAL strategy in local relocations.
9685 gold_assert(r_sym < local_count);
9686
9687 // We are adjusting a section symbol. We need to find
9688 // the symbol table index of the section symbol for
9689 // the output section corresponding to input section
9690 // in which this symbol is defined.
9691 bool is_ordinary;
9692 unsigned int shndx = object->local_symbol_input_shndx(r_sym, &is_ordinary);
9693 gold_assert(is_ordinary);
9694 Output_section* os = object->output_section(shndx);
9695 gold_assert(os != NULL);
9696 gold_assert(os->needs_symtab_index());
9697 unsigned int new_symndx = os->symtab_index();
9698
9699 // Get the new offset--the location in the output section where
9700 // this relocation should be applied.
9701
9702 Arm_address offset = reloc.get_r_offset();
9703 Arm_address new_offset;
9704 if (offset_in_output_section != invalid_address)
9705 new_offset = offset + offset_in_output_section;
9706 else
9707 {
9708 section_offset_type sot_offset =
9709 convert_types<section_offset_type, Arm_address>(offset);
9710 section_offset_type new_sot_offset =
9711 output_section->output_offset(object, relinfo->data_shndx,
9712 sot_offset);
9713 gold_assert(new_sot_offset != -1);
9714 new_offset = new_sot_offset;
9715 }
9716
9717 // In an object file, r_offset is an offset within the section.
9718 // In an executable or dynamic object, generated by
9719 // --emit-relocs, r_offset is an absolute address.
9720 if (!parameters->options().relocatable())
9721 {
9722 new_offset += view_address;
9723 if (offset_in_output_section != invalid_address)
9724 new_offset -= offset_in_output_section;
9725 }
9726
9727 reloc_write.put_r_offset(new_offset);
9728 reloc_write.put_r_info(elfcpp::elf_r_info<32>(new_symndx, r_type));
9729
9730 // Handle the reloc addend.
9731 // The relocation uses a section symbol in the input file.
9732 // We are adjusting it to use a section symbol in the output
9733 // file. The input section symbol refers to some address in
9734 // the input section. We need the relocation in the output
9735 // file to refer to that same address. This adjustment to
9736 // the addend is the same calculation we use for a simple
9737 // absolute relocation for the input section symbol.
9738
9739 const Symbol_value<32>* psymval = object->local_symbol(r_sym);
9740
9741 // Handle THUMB bit.
9742 Symbol_value<32> symval;
9743 Arm_address thumb_bit =
9744 object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
9745 if (thumb_bit != 0
9746 && arp->uses_thumb_bit()
9747 && ((psymval->value(object, 0) & 1) != 0))
9748 {
9749 Arm_address stripped_value =
9750 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
9751 symval.set_output_value(stripped_value);
9752 psymval = &symval;
9753 }
9754
9755 unsigned char* paddend = view + offset;
9756 typename Arm_relocate_functions<big_endian>::Status reloc_status =
9757 Arm_relocate_functions<big_endian>::STATUS_OKAY;
9758 switch (r_type)
9759 {
9760 case elfcpp::R_ARM_ABS8:
9761 reloc_status = Arm_relocate_functions<big_endian>::abs8(paddend, object,
9762 psymval);
9763 break;
9764
9765 case elfcpp::R_ARM_ABS12:
9766 reloc_status = Arm_relocate_functions<big_endian>::abs12(paddend, object,
9767 psymval);
9768 break;
9769
9770 case elfcpp::R_ARM_ABS16:
9771 reloc_status = Arm_relocate_functions<big_endian>::abs16(paddend, object,
9772 psymval);
9773 break;
9774
9775 case elfcpp::R_ARM_THM_ABS5:
9776 reloc_status = Arm_relocate_functions<big_endian>::thm_abs5(paddend,
9777 object,
9778 psymval);
9779 break;
9780
9781 case elfcpp::R_ARM_MOVW_ABS_NC:
9782 case elfcpp::R_ARM_MOVW_PREL_NC:
9783 case elfcpp::R_ARM_MOVW_BREL_NC:
9784 case elfcpp::R_ARM_MOVW_BREL:
9785 reloc_status = Arm_relocate_functions<big_endian>::movw(
9786 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9787 break;
9788
9789 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
9790 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
9791 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
9792 case elfcpp::R_ARM_THM_MOVW_BREL:
9793 reloc_status = Arm_relocate_functions<big_endian>::thm_movw(
9794 paddend, object, psymval, 0, thumb_bit, arp->checks_overflow());
9795 break;
9796
9797 case elfcpp::R_ARM_THM_CALL:
9798 case elfcpp::R_ARM_THM_XPC22:
9799 case elfcpp::R_ARM_THM_JUMP24:
9800 reloc_status =
9801 Arm_relocate_functions<big_endian>::thumb_branch_common(
9802 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9803 false);
9804 break;
9805
9806 case elfcpp::R_ARM_PLT32:
9807 case elfcpp::R_ARM_CALL:
9808 case elfcpp::R_ARM_JUMP24:
9809 case elfcpp::R_ARM_XPC25:
9810 reloc_status =
9811 Arm_relocate_functions<big_endian>::arm_branch_common(
9812 r_type, relinfo, paddend, NULL, object, 0, psymval, 0, thumb_bit,
9813 false);
9814 break;
9815
9816 case elfcpp::R_ARM_THM_JUMP19:
9817 reloc_status =
9818 Arm_relocate_functions<big_endian>::thm_jump19(paddend, object,
9819 psymval, 0, thumb_bit);
9820 break;
9821
9822 case elfcpp::R_ARM_THM_JUMP6:
9823 reloc_status =
9824 Arm_relocate_functions<big_endian>::thm_jump6(paddend, object, psymval,
9825 0);
9826 break;
9827
9828 case elfcpp::R_ARM_THM_JUMP8:
9829 reloc_status =
9830 Arm_relocate_functions<big_endian>::thm_jump8(paddend, object, psymval,
9831 0);
9832 break;
9833
9834 case elfcpp::R_ARM_THM_JUMP11:
9835 reloc_status =
9836 Arm_relocate_functions<big_endian>::thm_jump11(paddend, object, psymval,
9837 0);
9838 break;
9839
9840 case elfcpp::R_ARM_PREL31:
9841 reloc_status =
9842 Arm_relocate_functions<big_endian>::prel31(paddend, object, psymval, 0,
9843 thumb_bit);
9844 break;
9845
9846 case elfcpp::R_ARM_THM_PC8:
9847 reloc_status =
9848 Arm_relocate_functions<big_endian>::thm_pc8(paddend, object, psymval,
9849 0);
9850 break;
9851
9852 case elfcpp::R_ARM_THM_PC12:
9853 reloc_status =
9854 Arm_relocate_functions<big_endian>::thm_pc12(paddend, object, psymval,
9855 0);
9856 break;
9857
9858 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
9859 reloc_status =
9860 Arm_relocate_functions<big_endian>::thm_alu11(paddend, object, psymval,
9861 0, thumb_bit);
9862 break;
9863
9864 // These relocation truncate relocation results so we cannot handle them
9865 // in a relocatable link.
9866 case elfcpp::R_ARM_MOVT_ABS:
9867 case elfcpp::R_ARM_THM_MOVT_ABS:
9868 case elfcpp::R_ARM_MOVT_PREL:
9869 case elfcpp::R_ARM_MOVT_BREL:
9870 case elfcpp::R_ARM_THM_MOVT_PREL:
9871 case elfcpp::R_ARM_THM_MOVT_BREL:
9872 case elfcpp::R_ARM_ALU_PC_G0_NC:
9873 case elfcpp::R_ARM_ALU_PC_G0:
9874 case elfcpp::R_ARM_ALU_PC_G1_NC:
9875 case elfcpp::R_ARM_ALU_PC_G1:
9876 case elfcpp::R_ARM_ALU_PC_G2:
9877 case elfcpp::R_ARM_ALU_SB_G0_NC:
9878 case elfcpp::R_ARM_ALU_SB_G0:
9879 case elfcpp::R_ARM_ALU_SB_G1_NC:
9880 case elfcpp::R_ARM_ALU_SB_G1:
9881 case elfcpp::R_ARM_ALU_SB_G2:
9882 case elfcpp::R_ARM_LDR_PC_G0:
9883 case elfcpp::R_ARM_LDR_PC_G1:
9884 case elfcpp::R_ARM_LDR_PC_G2:
9885 case elfcpp::R_ARM_LDR_SB_G0:
9886 case elfcpp::R_ARM_LDR_SB_G1:
9887 case elfcpp::R_ARM_LDR_SB_G2:
9888 case elfcpp::R_ARM_LDRS_PC_G0:
9889 case elfcpp::R_ARM_LDRS_PC_G1:
9890 case elfcpp::R_ARM_LDRS_PC_G2:
9891 case elfcpp::R_ARM_LDRS_SB_G0:
9892 case elfcpp::R_ARM_LDRS_SB_G1:
9893 case elfcpp::R_ARM_LDRS_SB_G2:
9894 case elfcpp::R_ARM_LDC_PC_G0:
9895 case elfcpp::R_ARM_LDC_PC_G1:
9896 case elfcpp::R_ARM_LDC_PC_G2:
9897 case elfcpp::R_ARM_LDC_SB_G0:
9898 case elfcpp::R_ARM_LDC_SB_G1:
9899 case elfcpp::R_ARM_LDC_SB_G2:
9900 gold_error(_("cannot handle %s in a relocatable link"),
9901 arp->name().c_str());
9902 break;
9903
9904 default:
9905 gold_unreachable();
9906 }
9907
9908 // Report any errors.
9909 switch (reloc_status)
9910 {
9911 case Arm_relocate_functions<big_endian>::STATUS_OKAY:
9912 break;
9913 case Arm_relocate_functions<big_endian>::STATUS_OVERFLOW:
9914 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9915 _("relocation overflow in %s"),
9916 arp->name().c_str());
9917 break;
9918 case Arm_relocate_functions<big_endian>::STATUS_BAD_RELOC:
9919 gold_error_at_location(relinfo, relnum, reloc.get_r_offset(),
9920 _("unexpected opcode while processing relocation %s"),
9921 arp->name().c_str());
9922 break;
9923 default:
9924 gold_unreachable();
9925 }
9926 }
9927
9928 // Return the value to use for a dynamic symbol which requires special
9929 // treatment. This is how we support equality comparisons of function
9930 // pointers across shared library boundaries, as described in the
9931 // processor specific ABI supplement.
9932
9933 template<bool big_endian>
9934 uint64_t
9935 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
9936 {
9937 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
9938 return this->plt_section()->address() + gsym->plt_offset();
9939 }
9940
9941 // Map platform-specific relocs to real relocs
9942 //
9943 template<bool big_endian>
9944 unsigned int
9945 Target_arm<big_endian>::get_real_reloc_type(unsigned int r_type)
9946 {
9947 switch (r_type)
9948 {
9949 case elfcpp::R_ARM_TARGET1:
9950 // This is either R_ARM_ABS32 or R_ARM_REL32;
9951 return elfcpp::R_ARM_ABS32;
9952
9953 case elfcpp::R_ARM_TARGET2:
9954 // This can be any reloc type but usually is R_ARM_GOT_PREL
9955 return elfcpp::R_ARM_GOT_PREL;
9956
9957 default:
9958 return r_type;
9959 }
9960 }
9961
9962 // Whether if two EABI versions V1 and V2 are compatible.
9963
9964 template<bool big_endian>
9965 bool
9966 Target_arm<big_endian>::are_eabi_versions_compatible(
9967 elfcpp::Elf_Word v1,
9968 elfcpp::Elf_Word v2)
9969 {
9970 // v4 and v5 are the same spec before and after it was released,
9971 // so allow mixing them.
9972 if ((v1 == elfcpp::EF_ARM_EABI_UNKNOWN || v2 == elfcpp::EF_ARM_EABI_UNKNOWN)
9973 || (v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
9974 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9975 return true;
9976
9977 return v1 == v2;
9978 }
9979
9980 // Combine FLAGS from an input object called NAME and the processor-specific
9981 // flags in the ELF header of the output. Much of this is adapted from the
9982 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9983 // in bfd/elf32-arm.c.
9984
9985 template<bool big_endian>
9986 void
9987 Target_arm<big_endian>::merge_processor_specific_flags(
9988 const std::string& name,
9989 elfcpp::Elf_Word flags)
9990 {
9991 if (this->are_processor_specific_flags_set())
9992 {
9993 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9994
9995 // Nothing to merge if flags equal to those in output.
9996 if (flags == out_flags)
9997 return;
9998
9999 // Complain about various flag mismatches.
10000 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
10001 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
10002 if (!this->are_eabi_versions_compatible(version1, version2)
10003 && parameters->options().warn_mismatch())
10004 gold_error(_("Source object %s has EABI version %d but output has "
10005 "EABI version %d."),
10006 name.c_str(),
10007 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
10008 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
10009 }
10010 else
10011 {
10012 // If the input is the default architecture and had the default
10013 // flags then do not bother setting the flags for the output
10014 // architecture, instead allow future merges to do this. If no
10015 // future merges ever set these flags then they will retain their
10016 // uninitialised values, which surprise surprise, correspond
10017 // to the default values.
10018 if (flags == 0)
10019 return;
10020
10021 // This is the first time, just copy the flags.
10022 // We only copy the EABI version for now.
10023 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
10024 }
10025 }
10026
10027 // Adjust ELF file header.
10028 template<bool big_endian>
10029 void
10030 Target_arm<big_endian>::do_adjust_elf_header(
10031 unsigned char* view,
10032 int len)
10033 {
10034 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
10035
10036 elfcpp::Ehdr<32, big_endian> ehdr(view);
10037 elfcpp::Elf_Word flags = this->processor_specific_flags();
10038 unsigned char e_ident[elfcpp::EI_NIDENT];
10039 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
10040
10041 if (elfcpp::arm_eabi_version(flags)
10042 == elfcpp::EF_ARM_EABI_UNKNOWN)
10043 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
10044 else
10045 e_ident[elfcpp::EI_OSABI] = 0;
10046 e_ident[elfcpp::EI_ABIVERSION] = 0;
10047
10048 // FIXME: Do EF_ARM_BE8 adjustment.
10049
10050 // If we're working in EABI_VER5, set the hard/soft float ABI flags
10051 // as appropriate.
10052 if (elfcpp::arm_eabi_version(flags) == elfcpp::EF_ARM_EABI_VER5)
10053 {
10054 elfcpp::Elf_Half type = ehdr.get_e_type();
10055 if (type == elfcpp::ET_EXEC || type == elfcpp::ET_DYN)
10056 {
10057 Object_attribute* attr = this->get_aeabi_object_attribute(elfcpp::Tag_ABI_VFP_args);
10058 if (attr->int_value())
10059 flags |= elfcpp::EF_ARM_ABI_FLOAT_HARD;
10060 else
10061 flags |= elfcpp::EF_ARM_ABI_FLOAT_SOFT;
10062 this->set_processor_specific_flags(flags);
10063 }
10064 }
10065 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
10066 oehdr.put_e_ident(e_ident);
10067 }
10068
10069 // do_make_elf_object to override the same function in the base class.
10070 // We need to use a target-specific sub-class of
10071 // Sized_relobj_file<32, big_endian> to store ARM specific information.
10072 // Hence we need to have our own ELF object creation.
10073
10074 template<bool big_endian>
10075 Object*
10076 Target_arm<big_endian>::do_make_elf_object(
10077 const std::string& name,
10078 Input_file* input_file,
10079 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
10080 {
10081 int et = ehdr.get_e_type();
10082 // ET_EXEC files are valid input for --just-symbols/-R,
10083 // and we treat them as relocatable objects.
10084 if (et == elfcpp::ET_REL
10085 || (et == elfcpp::ET_EXEC && input_file->just_symbols()))
10086 {
10087 Arm_relobj<big_endian>* obj =
10088 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
10089 obj->setup();
10090 return obj;
10091 }
10092 else if (et == elfcpp::ET_DYN)
10093 {
10094 Sized_dynobj<32, big_endian>* obj =
10095 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
10096 obj->setup();
10097 return obj;
10098 }
10099 else
10100 {
10101 gold_error(_("%s: unsupported ELF file type %d"),
10102 name.c_str(), et);
10103 return NULL;
10104 }
10105 }
10106
10107 // Read the architecture from the Tag_also_compatible_with attribute, if any.
10108 // Returns -1 if no architecture could be read.
10109 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
10110
10111 template<bool big_endian>
10112 int
10113 Target_arm<big_endian>::get_secondary_compatible_arch(
10114 const Attributes_section_data* pasd)
10115 {
10116 const Object_attribute* known_attributes =
10117 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10118
10119 // Note: the tag and its argument below are uleb128 values, though
10120 // currently-defined values fit in one byte for each.
10121 const std::string& sv =
10122 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
10123 if (sv.size() == 2
10124 && sv.data()[0] == elfcpp::Tag_CPU_arch
10125 && (sv.data()[1] & 128) != 128)
10126 return sv.data()[1];
10127
10128 // This tag is "safely ignorable", so don't complain if it looks funny.
10129 return -1;
10130 }
10131
10132 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
10133 // The tag is removed if ARCH is -1.
10134 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
10135
10136 template<bool big_endian>
10137 void
10138 Target_arm<big_endian>::set_secondary_compatible_arch(
10139 Attributes_section_data* pasd,
10140 int arch)
10141 {
10142 Object_attribute* known_attributes =
10143 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
10144
10145 if (arch == -1)
10146 {
10147 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
10148 return;
10149 }
10150
10151 // Note: the tag and its argument below are uleb128 values, though
10152 // currently-defined values fit in one byte for each.
10153 char sv[3];
10154 sv[0] = elfcpp::Tag_CPU_arch;
10155 gold_assert(arch != 0);
10156 sv[1] = arch;
10157 sv[2] = '\0';
10158
10159 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
10160 }
10161
10162 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
10163 // into account.
10164 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
10165
10166 template<bool big_endian>
10167 int
10168 Target_arm<big_endian>::tag_cpu_arch_combine(
10169 const char* name,
10170 int oldtag,
10171 int* secondary_compat_out,
10172 int newtag,
10173 int secondary_compat)
10174 {
10175 #define T(X) elfcpp::TAG_CPU_ARCH_##X
10176 static const int v6t2[] =
10177 {
10178 T(V6T2), // PRE_V4.
10179 T(V6T2), // V4.
10180 T(V6T2), // V4T.
10181 T(V6T2), // V5T.
10182 T(V6T2), // V5TE.
10183 T(V6T2), // V5TEJ.
10184 T(V6T2), // V6.
10185 T(V7), // V6KZ.
10186 T(V6T2) // V6T2.
10187 };
10188 static const int v6k[] =
10189 {
10190 T(V6K), // PRE_V4.
10191 T(V6K), // V4.
10192 T(V6K), // V4T.
10193 T(V6K), // V5T.
10194 T(V6K), // V5TE.
10195 T(V6K), // V5TEJ.
10196 T(V6K), // V6.
10197 T(V6KZ), // V6KZ.
10198 T(V7), // V6T2.
10199 T(V6K) // V6K.
10200 };
10201 static const int v7[] =
10202 {
10203 T(V7), // PRE_V4.
10204 T(V7), // V4.
10205 T(V7), // V4T.
10206 T(V7), // V5T.
10207 T(V7), // V5TE.
10208 T(V7), // V5TEJ.
10209 T(V7), // V6.
10210 T(V7), // V6KZ.
10211 T(V7), // V6T2.
10212 T(V7), // V6K.
10213 T(V7) // V7.
10214 };
10215 static const int v6_m[] =
10216 {
10217 -1, // PRE_V4.
10218 -1, // V4.
10219 T(V6K), // V4T.
10220 T(V6K), // V5T.
10221 T(V6K), // V5TE.
10222 T(V6K), // V5TEJ.
10223 T(V6K), // V6.
10224 T(V6KZ), // V6KZ.
10225 T(V7), // V6T2.
10226 T(V6K), // V6K.
10227 T(V7), // V7.
10228 T(V6_M) // V6_M.
10229 };
10230 static const int v6s_m[] =
10231 {
10232 -1, // PRE_V4.
10233 -1, // V4.
10234 T(V6K), // V4T.
10235 T(V6K), // V5T.
10236 T(V6K), // V5TE.
10237 T(V6K), // V5TEJ.
10238 T(V6K), // V6.
10239 T(V6KZ), // V6KZ.
10240 T(V7), // V6T2.
10241 T(V6K), // V6K.
10242 T(V7), // V7.
10243 T(V6S_M), // V6_M.
10244 T(V6S_M) // V6S_M.
10245 };
10246 static const int v7e_m[] =
10247 {
10248 -1, // PRE_V4.
10249 -1, // V4.
10250 T(V7E_M), // V4T.
10251 T(V7E_M), // V5T.
10252 T(V7E_M), // V5TE.
10253 T(V7E_M), // V5TEJ.
10254 T(V7E_M), // V6.
10255 T(V7E_M), // V6KZ.
10256 T(V7E_M), // V6T2.
10257 T(V7E_M), // V6K.
10258 T(V7E_M), // V7.
10259 T(V7E_M), // V6_M.
10260 T(V7E_M), // V6S_M.
10261 T(V7E_M) // V7E_M.
10262 };
10263 static const int v4t_plus_v6_m[] =
10264 {
10265 -1, // PRE_V4.
10266 -1, // V4.
10267 T(V4T), // V4T.
10268 T(V5T), // V5T.
10269 T(V5TE), // V5TE.
10270 T(V5TEJ), // V5TEJ.
10271 T(V6), // V6.
10272 T(V6KZ), // V6KZ.
10273 T(V6T2), // V6T2.
10274 T(V6K), // V6K.
10275 T(V7), // V7.
10276 T(V6_M), // V6_M.
10277 T(V6S_M), // V6S_M.
10278 T(V7E_M), // V7E_M.
10279 T(V4T_PLUS_V6_M) // V4T plus V6_M.
10280 };
10281 static const int* comb[] =
10282 {
10283 v6t2,
10284 v6k,
10285 v7,
10286 v6_m,
10287 v6s_m,
10288 v7e_m,
10289 // Pseudo-architecture.
10290 v4t_plus_v6_m
10291 };
10292
10293 // Check we've not got a higher architecture than we know about.
10294
10295 if (oldtag > elfcpp::MAX_TAG_CPU_ARCH || newtag > elfcpp::MAX_TAG_CPU_ARCH)
10296 {
10297 gold_error(_("%s: unknown CPU architecture"), name);
10298 return -1;
10299 }
10300
10301 // Override old tag if we have a Tag_also_compatible_with on the output.
10302
10303 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
10304 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
10305 oldtag = T(V4T_PLUS_V6_M);
10306
10307 // And override the new tag if we have a Tag_also_compatible_with on the
10308 // input.
10309
10310 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
10311 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
10312 newtag = T(V4T_PLUS_V6_M);
10313
10314 // Architectures before V6KZ add features monotonically.
10315 int tagh = std::max(oldtag, newtag);
10316 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
10317 return tagh;
10318
10319 int tagl = std::min(oldtag, newtag);
10320 int result = comb[tagh - T(V6T2)][tagl];
10321
10322 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
10323 // as the canonical version.
10324 if (result == T(V4T_PLUS_V6_M))
10325 {
10326 result = T(V4T);
10327 *secondary_compat_out = T(V6_M);
10328 }
10329 else
10330 *secondary_compat_out = -1;
10331
10332 if (result == -1)
10333 {
10334 gold_error(_("%s: conflicting CPU architectures %d/%d"),
10335 name, oldtag, newtag);
10336 return -1;
10337 }
10338
10339 return result;
10340 #undef T
10341 }
10342
10343 // Helper to print AEABI enum tag value.
10344
10345 template<bool big_endian>
10346 std::string
10347 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
10348 {
10349 static const char* aeabi_enum_names[] =
10350 { "", "variable-size", "32-bit", "" };
10351 const size_t aeabi_enum_names_size =
10352 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
10353
10354 if (value < aeabi_enum_names_size)
10355 return std::string(aeabi_enum_names[value]);
10356 else
10357 {
10358 char buffer[100];
10359 sprintf(buffer, "<unknown value %u>", value);
10360 return std::string(buffer);
10361 }
10362 }
10363
10364 // Return the string value to store in TAG_CPU_name.
10365
10366 template<bool big_endian>
10367 std::string
10368 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
10369 {
10370 static const char* name_table[] = {
10371 // These aren't real CPU names, but we can't guess
10372 // that from the architecture version alone.
10373 "Pre v4",
10374 "ARM v4",
10375 "ARM v4T",
10376 "ARM v5T",
10377 "ARM v5TE",
10378 "ARM v5TEJ",
10379 "ARM v6",
10380 "ARM v6KZ",
10381 "ARM v6T2",
10382 "ARM v6K",
10383 "ARM v7",
10384 "ARM v6-M",
10385 "ARM v6S-M",
10386 "ARM v7E-M"
10387 };
10388 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
10389
10390 if (value < name_table_size)
10391 return std::string(name_table[value]);
10392 else
10393 {
10394 char buffer[100];
10395 sprintf(buffer, "<unknown CPU value %u>", value);
10396 return std::string(buffer);
10397 }
10398 }
10399
10400 // Query attributes object to see if integer divide instructions may be
10401 // present in an object.
10402
10403 template<bool big_endian>
10404 bool
10405 Target_arm<big_endian>::attributes_accept_div(int arch, int profile,
10406 const Object_attribute* div_attr)
10407 {
10408 switch (div_attr->int_value())
10409 {
10410 case 0:
10411 // Integer divide allowed if instruction contained in
10412 // archetecture.
10413 if (arch == elfcpp::TAG_CPU_ARCH_V7 && (profile == 'R' || profile == 'M'))
10414 return true;
10415 else if (arch >= elfcpp::TAG_CPU_ARCH_V7E_M)
10416 return true;
10417 else
10418 return false;
10419
10420 case 1:
10421 // Integer divide explicitly prohibited.
10422 return false;
10423
10424 default:
10425 // Unrecognised case - treat as allowing divide everywhere.
10426 case 2:
10427 // Integer divide allowed in ARM state.
10428 return true;
10429 }
10430 }
10431
10432 // Query attributes object to see if integer divide instructions are
10433 // forbidden to be in the object. This is not the inverse of
10434 // attributes_accept_div.
10435
10436 template<bool big_endian>
10437 bool
10438 Target_arm<big_endian>::attributes_forbid_div(const Object_attribute* div_attr)
10439 {
10440 return div_attr->int_value() == 1;
10441 }
10442
10443 // Merge object attributes from input file called NAME with those of the
10444 // output. The input object attributes are in the object pointed by PASD.
10445
10446 template<bool big_endian>
10447 void
10448 Target_arm<big_endian>::merge_object_attributes(
10449 const char* name,
10450 const Attributes_section_data* pasd)
10451 {
10452 // Return if there is no attributes section data.
10453 if (pasd == NULL)
10454 return;
10455
10456 // If output has no object attributes, just copy.
10457 const int vendor = Object_attribute::OBJ_ATTR_PROC;
10458 if (this->attributes_section_data_ == NULL)
10459 {
10460 this->attributes_section_data_ = new Attributes_section_data(*pasd);
10461 Object_attribute* out_attr =
10462 this->attributes_section_data_->known_attributes(vendor);
10463
10464 // We do not output objects with Tag_MPextension_use_legacy - we move
10465 // the attribute's value to Tag_MPextension_use. */
10466 if (out_attr[elfcpp::Tag_MPextension_use_legacy].int_value() != 0)
10467 {
10468 if (out_attr[elfcpp::Tag_MPextension_use].int_value() != 0
10469 && out_attr[elfcpp::Tag_MPextension_use_legacy].int_value()
10470 != out_attr[elfcpp::Tag_MPextension_use].int_value())
10471 {
10472 gold_error(_("%s has both the current and legacy "
10473 "Tag_MPextension_use attributes"),
10474 name);
10475 }
10476
10477 out_attr[elfcpp::Tag_MPextension_use] =
10478 out_attr[elfcpp::Tag_MPextension_use_legacy];
10479 out_attr[elfcpp::Tag_MPextension_use_legacy].set_type(0);
10480 out_attr[elfcpp::Tag_MPextension_use_legacy].set_int_value(0);
10481 }
10482
10483 return;
10484 }
10485
10486 const Object_attribute* in_attr = pasd->known_attributes(vendor);
10487 Object_attribute* out_attr =
10488 this->attributes_section_data_->known_attributes(vendor);
10489
10490 // This needs to happen before Tag_ABI_FP_number_model is merged. */
10491 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
10492 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
10493 {
10494 // Ignore mismatches if the object doesn't use floating point. */
10495 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
10496 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
10497 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
10498 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
10499 && parameters->options().warn_mismatch())
10500 gold_error(_("%s uses VFP register arguments, output does not"),
10501 name);
10502 }
10503
10504 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
10505 {
10506 // Merge this attribute with existing attributes.
10507 switch (i)
10508 {
10509 case elfcpp::Tag_CPU_raw_name:
10510 case elfcpp::Tag_CPU_name:
10511 // These are merged after Tag_CPU_arch.
10512 break;
10513
10514 case elfcpp::Tag_ABI_optimization_goals:
10515 case elfcpp::Tag_ABI_FP_optimization_goals:
10516 // Use the first value seen.
10517 break;
10518
10519 case elfcpp::Tag_CPU_arch:
10520 {
10521 unsigned int saved_out_attr = out_attr->int_value();
10522 // Merge Tag_CPU_arch and Tag_also_compatible_with.
10523 int secondary_compat =
10524 this->get_secondary_compatible_arch(pasd);
10525 int secondary_compat_out =
10526 this->get_secondary_compatible_arch(
10527 this->attributes_section_data_);
10528 out_attr[i].set_int_value(
10529 tag_cpu_arch_combine(name, out_attr[i].int_value(),
10530 &secondary_compat_out,
10531 in_attr[i].int_value(),
10532 secondary_compat));
10533 this->set_secondary_compatible_arch(this->attributes_section_data_,
10534 secondary_compat_out);
10535
10536 // Merge Tag_CPU_name and Tag_CPU_raw_name.
10537 if (out_attr[i].int_value() == saved_out_attr)
10538 ; // Leave the names alone.
10539 else if (out_attr[i].int_value() == in_attr[i].int_value())
10540 {
10541 // The output architecture has been changed to match the
10542 // input architecture. Use the input names.
10543 out_attr[elfcpp::Tag_CPU_name].set_string_value(
10544 in_attr[elfcpp::Tag_CPU_name].string_value());
10545 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
10546 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
10547 }
10548 else
10549 {
10550 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
10551 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
10552 }
10553
10554 // If we still don't have a value for Tag_CPU_name,
10555 // make one up now. Tag_CPU_raw_name remains blank.
10556 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
10557 {
10558 const std::string cpu_name =
10559 this->tag_cpu_name_value(out_attr[i].int_value());
10560 // FIXME: If we see an unknown CPU, this will be set
10561 // to "<unknown CPU n>", where n is the attribute value.
10562 // This is different from BFD, which leaves the name alone.
10563 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
10564 }
10565 }
10566 break;
10567
10568 case elfcpp::Tag_ARM_ISA_use:
10569 case elfcpp::Tag_THUMB_ISA_use:
10570 case elfcpp::Tag_WMMX_arch:
10571 case elfcpp::Tag_Advanced_SIMD_arch:
10572 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
10573 case elfcpp::Tag_ABI_FP_rounding:
10574 case elfcpp::Tag_ABI_FP_exceptions:
10575 case elfcpp::Tag_ABI_FP_user_exceptions:
10576 case elfcpp::Tag_ABI_FP_number_model:
10577 case elfcpp::Tag_VFP_HP_extension:
10578 case elfcpp::Tag_CPU_unaligned_access:
10579 case elfcpp::Tag_T2EE_use:
10580 case elfcpp::Tag_Virtualization_use:
10581 case elfcpp::Tag_MPextension_use:
10582 // Use the largest value specified.
10583 if (in_attr[i].int_value() > out_attr[i].int_value())
10584 out_attr[i].set_int_value(in_attr[i].int_value());
10585 break;
10586
10587 case elfcpp::Tag_ABI_align8_preserved:
10588 case elfcpp::Tag_ABI_PCS_RO_data:
10589 // Use the smallest value specified.
10590 if (in_attr[i].int_value() < out_attr[i].int_value())
10591 out_attr[i].set_int_value(in_attr[i].int_value());
10592 break;
10593
10594 case elfcpp::Tag_ABI_align8_needed:
10595 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
10596 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
10597 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
10598 == 0)))
10599 {
10600 // This error message should be enabled once all non-conforming
10601 // binaries in the toolchain have had the attributes set
10602 // properly.
10603 // gold_error(_("output 8-byte data alignment conflicts with %s"),
10604 // name);
10605 }
10606 // Fall through.
10607 case elfcpp::Tag_ABI_FP_denormal:
10608 case elfcpp::Tag_ABI_PCS_GOT_use:
10609 {
10610 // These tags have 0 = don't care, 1 = strong requirement,
10611 // 2 = weak requirement.
10612 static const int order_021[3] = {0, 2, 1};
10613
10614 // Use the "greatest" from the sequence 0, 2, 1, or the largest
10615 // value if greater than 2 (for future-proofing).
10616 if ((in_attr[i].int_value() > 2
10617 && in_attr[i].int_value() > out_attr[i].int_value())
10618 || (in_attr[i].int_value() <= 2
10619 && out_attr[i].int_value() <= 2
10620 && (order_021[in_attr[i].int_value()]
10621 > order_021[out_attr[i].int_value()])))
10622 out_attr[i].set_int_value(in_attr[i].int_value());
10623 }
10624 break;
10625
10626 case elfcpp::Tag_CPU_arch_profile:
10627 if (out_attr[i].int_value() != in_attr[i].int_value())
10628 {
10629 // 0 will merge with anything.
10630 // 'A' and 'S' merge to 'A'.
10631 // 'R' and 'S' merge to 'R'.
10632 // 'M' and 'A|R|S' is an error.
10633 if (out_attr[i].int_value() == 0
10634 || (out_attr[i].int_value() == 'S'
10635 && (in_attr[i].int_value() == 'A'
10636 || in_attr[i].int_value() == 'R')))
10637 out_attr[i].set_int_value(in_attr[i].int_value());
10638 else if (in_attr[i].int_value() == 0
10639 || (in_attr[i].int_value() == 'S'
10640 && (out_attr[i].int_value() == 'A'
10641 || out_attr[i].int_value() == 'R')))
10642 ; // Do nothing.
10643 else if (parameters->options().warn_mismatch())
10644 {
10645 gold_error
10646 (_("conflicting architecture profiles %c/%c"),
10647 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
10648 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
10649 }
10650 }
10651 break;
10652 case elfcpp::Tag_VFP_arch:
10653 {
10654 static const struct
10655 {
10656 int ver;
10657 int regs;
10658 } vfp_versions[7] =
10659 {
10660 {0, 0},
10661 {1, 16},
10662 {2, 16},
10663 {3, 32},
10664 {3, 16},
10665 {4, 32},
10666 {4, 16}
10667 };
10668
10669 // Values greater than 6 aren't defined, so just pick the
10670 // biggest.
10671 if (in_attr[i].int_value() > 6
10672 && in_attr[i].int_value() > out_attr[i].int_value())
10673 {
10674 *out_attr = *in_attr;
10675 break;
10676 }
10677 // The output uses the superset of input features
10678 // (ISA version) and registers.
10679 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
10680 vfp_versions[out_attr[i].int_value()].ver);
10681 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
10682 vfp_versions[out_attr[i].int_value()].regs);
10683 // This assumes all possible supersets are also a valid
10684 // options.
10685 int newval;
10686 for (newval = 6; newval > 0; newval--)
10687 {
10688 if (regs == vfp_versions[newval].regs
10689 && ver == vfp_versions[newval].ver)
10690 break;
10691 }
10692 out_attr[i].set_int_value(newval);
10693 }
10694 break;
10695 case elfcpp::Tag_PCS_config:
10696 if (out_attr[i].int_value() == 0)
10697 out_attr[i].set_int_value(in_attr[i].int_value());
10698 else if (in_attr[i].int_value() != 0
10699 && out_attr[i].int_value() != 0
10700 && parameters->options().warn_mismatch())
10701 {
10702 // It's sometimes ok to mix different configs, so this is only
10703 // a warning.
10704 gold_warning(_("%s: conflicting platform configuration"), name);
10705 }
10706 break;
10707 case elfcpp::Tag_ABI_PCS_R9_use:
10708 if (in_attr[i].int_value() != out_attr[i].int_value()
10709 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
10710 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
10711 && parameters->options().warn_mismatch())
10712 {
10713 gold_error(_("%s: conflicting use of R9"), name);
10714 }
10715 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
10716 out_attr[i].set_int_value(in_attr[i].int_value());
10717 break;
10718 case elfcpp::Tag_ABI_PCS_RW_data:
10719 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
10720 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10721 != elfcpp::AEABI_R9_SB)
10722 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
10723 != elfcpp::AEABI_R9_unused)
10724 && parameters->options().warn_mismatch())
10725 {
10726 gold_error(_("%s: SB relative addressing conflicts with use "
10727 "of R9"),
10728 name);
10729 }
10730 // Use the smallest value specified.
10731 if (in_attr[i].int_value() < out_attr[i].int_value())
10732 out_attr[i].set_int_value(in_attr[i].int_value());
10733 break;
10734 case elfcpp::Tag_ABI_PCS_wchar_t:
10735 if (out_attr[i].int_value()
10736 && in_attr[i].int_value()
10737 && out_attr[i].int_value() != in_attr[i].int_value()
10738 && parameters->options().warn_mismatch()
10739 && parameters->options().wchar_size_warning())
10740 {
10741 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
10742 "use %u-byte wchar_t; use of wchar_t values "
10743 "across objects may fail"),
10744 name, in_attr[i].int_value(),
10745 out_attr[i].int_value());
10746 }
10747 else if (in_attr[i].int_value() && !out_attr[i].int_value())
10748 out_attr[i].set_int_value(in_attr[i].int_value());
10749 break;
10750 case elfcpp::Tag_ABI_enum_size:
10751 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
10752 {
10753 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
10754 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
10755 {
10756 // The existing object is compatible with anything.
10757 // Use whatever requirements the new object has.
10758 out_attr[i].set_int_value(in_attr[i].int_value());
10759 }
10760 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
10761 && out_attr[i].int_value() != in_attr[i].int_value()
10762 && parameters->options().warn_mismatch()
10763 && parameters->options().enum_size_warning())
10764 {
10765 unsigned int in_value = in_attr[i].int_value();
10766 unsigned int out_value = out_attr[i].int_value();
10767 gold_warning(_("%s uses %s enums yet the output is to use "
10768 "%s enums; use of enum values across objects "
10769 "may fail"),
10770 name,
10771 this->aeabi_enum_name(in_value).c_str(),
10772 this->aeabi_enum_name(out_value).c_str());
10773 }
10774 }
10775 break;
10776 case elfcpp::Tag_ABI_VFP_args:
10777 // Already done.
10778 break;
10779 case elfcpp::Tag_ABI_WMMX_args:
10780 if (in_attr[i].int_value() != out_attr[i].int_value()
10781 && parameters->options().warn_mismatch())
10782 {
10783 gold_error(_("%s uses iWMMXt register arguments, output does "
10784 "not"),
10785 name);
10786 }
10787 break;
10788 case Object_attribute::Tag_compatibility:
10789 // Merged in target-independent code.
10790 break;
10791 case elfcpp::Tag_ABI_HardFP_use:
10792 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
10793 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
10794 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
10795 out_attr[i].set_int_value(3);
10796 else if (in_attr[i].int_value() > out_attr[i].int_value())
10797 out_attr[i].set_int_value(in_attr[i].int_value());
10798 break;
10799 case elfcpp::Tag_ABI_FP_16bit_format:
10800 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
10801 {
10802 if (in_attr[i].int_value() != out_attr[i].int_value()
10803 && parameters->options().warn_mismatch())
10804 gold_error(_("fp16 format mismatch between %s and output"),
10805 name);
10806 }
10807 if (in_attr[i].int_value() != 0)
10808 out_attr[i].set_int_value(in_attr[i].int_value());
10809 break;
10810
10811 case elfcpp::Tag_DIV_use:
10812 {
10813 // A value of zero on input means that the divide
10814 // instruction may be used if available in the base
10815 // architecture as specified via Tag_CPU_arch and
10816 // Tag_CPU_arch_profile. A value of 1 means that the user
10817 // did not want divide instructions. A value of 2
10818 // explicitly means that divide instructions were allowed
10819 // in ARM and Thumb state.
10820 int arch = this->
10821 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch)->
10822 int_value();
10823 int profile = this->
10824 get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile)->
10825 int_value();
10826 if (in_attr[i].int_value() == out_attr[i].int_value())
10827 {
10828 // Do nothing.
10829 }
10830 else if (attributes_forbid_div(&in_attr[i])
10831 && !attributes_accept_div(arch, profile, &out_attr[i]))
10832 out_attr[i].set_int_value(1);
10833 else if (attributes_forbid_div(&out_attr[i])
10834 && attributes_accept_div(arch, profile, &in_attr[i]))
10835 out_attr[i].set_int_value(in_attr[i].int_value());
10836 else if (in_attr[i].int_value() == 2)
10837 out_attr[i].set_int_value(in_attr[i].int_value());
10838 }
10839 break;
10840
10841 case elfcpp::Tag_MPextension_use_legacy:
10842 // We don't output objects with Tag_MPextension_use_legacy - we
10843 // move the value to Tag_MPextension_use.
10844 if (in_attr[i].int_value() != 0
10845 && in_attr[elfcpp::Tag_MPextension_use].int_value() != 0)
10846 {
10847 if (in_attr[elfcpp::Tag_MPextension_use].int_value()
10848 != in_attr[i].int_value())
10849 {
10850 gold_error(_("%s has has both the current and legacy "
10851 "Tag_MPextension_use attributes"),
10852 name);
10853 }
10854 }
10855
10856 if (in_attr[i].int_value()
10857 > out_attr[elfcpp::Tag_MPextension_use].int_value())
10858 out_attr[elfcpp::Tag_MPextension_use] = in_attr[i];
10859
10860 break;
10861
10862 case elfcpp::Tag_nodefaults:
10863 // This tag is set if it exists, but the value is unused (and is
10864 // typically zero). We don't actually need to do anything here -
10865 // the merge happens automatically when the type flags are merged
10866 // below.
10867 break;
10868 case elfcpp::Tag_also_compatible_with:
10869 // Already done in Tag_CPU_arch.
10870 break;
10871 case elfcpp::Tag_conformance:
10872 // Keep the attribute if it matches. Throw it away otherwise.
10873 // No attribute means no claim to conform.
10874 if (in_attr[i].string_value() != out_attr[i].string_value())
10875 out_attr[i].set_string_value("");
10876 break;
10877
10878 default:
10879 {
10880 const char* err_object = NULL;
10881
10882 // The "known_obj_attributes" table does contain some undefined
10883 // attributes. Ensure that there are unused.
10884 if (out_attr[i].int_value() != 0
10885 || out_attr[i].string_value() != "")
10886 err_object = "output";
10887 else if (in_attr[i].int_value() != 0
10888 || in_attr[i].string_value() != "")
10889 err_object = name;
10890
10891 if (err_object != NULL
10892 && parameters->options().warn_mismatch())
10893 {
10894 // Attribute numbers >=64 (mod 128) can be safely ignored.
10895 if ((i & 127) < 64)
10896 gold_error(_("%s: unknown mandatory EABI object attribute "
10897 "%d"),
10898 err_object, i);
10899 else
10900 gold_warning(_("%s: unknown EABI object attribute %d"),
10901 err_object, i);
10902 }
10903
10904 // Only pass on attributes that match in both inputs.
10905 if (!in_attr[i].matches(out_attr[i]))
10906 {
10907 out_attr[i].set_int_value(0);
10908 out_attr[i].set_string_value("");
10909 }
10910 }
10911 }
10912
10913 // If out_attr was copied from in_attr then it won't have a type yet.
10914 if (in_attr[i].type() && !out_attr[i].type())
10915 out_attr[i].set_type(in_attr[i].type());
10916 }
10917
10918 // Merge Tag_compatibility attributes and any common GNU ones.
10919 this->attributes_section_data_->merge(name, pasd);
10920
10921 // Check for any attributes not known on ARM.
10922 typedef Vendor_object_attributes::Other_attributes Other_attributes;
10923 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
10924 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
10925 Other_attributes* out_other_attributes =
10926 this->attributes_section_data_->other_attributes(vendor);
10927 Other_attributes::iterator out_iter = out_other_attributes->begin();
10928
10929 while (in_iter != in_other_attributes->end()
10930 || out_iter != out_other_attributes->end())
10931 {
10932 const char* err_object = NULL;
10933 int err_tag = 0;
10934
10935 // The tags for each list are in numerical order.
10936 // If the tags are equal, then merge.
10937 if (out_iter != out_other_attributes->end()
10938 && (in_iter == in_other_attributes->end()
10939 || in_iter->first > out_iter->first))
10940 {
10941 // This attribute only exists in output. We can't merge, and we
10942 // don't know what the tag means, so delete it.
10943 err_object = "output";
10944 err_tag = out_iter->first;
10945 int saved_tag = out_iter->first;
10946 delete out_iter->second;
10947 out_other_attributes->erase(out_iter);
10948 out_iter = out_other_attributes->upper_bound(saved_tag);
10949 }
10950 else if (in_iter != in_other_attributes->end()
10951 && (out_iter != out_other_attributes->end()
10952 || in_iter->first < out_iter->first))
10953 {
10954 // This attribute only exists in input. We can't merge, and we
10955 // don't know what the tag means, so ignore it.
10956 err_object = name;
10957 err_tag = in_iter->first;
10958 ++in_iter;
10959 }
10960 else // The tags are equal.
10961 {
10962 // As present, all attributes in the list are unknown, and
10963 // therefore can't be merged meaningfully.
10964 err_object = "output";
10965 err_tag = out_iter->first;
10966
10967 // Only pass on attributes that match in both inputs.
10968 if (!in_iter->second->matches(*(out_iter->second)))
10969 {
10970 // No match. Delete the attribute.
10971 int saved_tag = out_iter->first;
10972 delete out_iter->second;
10973 out_other_attributes->erase(out_iter);
10974 out_iter = out_other_attributes->upper_bound(saved_tag);
10975 }
10976 else
10977 {
10978 // Matched. Keep the attribute and move to the next.
10979 ++out_iter;
10980 ++in_iter;
10981 }
10982 }
10983
10984 if (err_object && parameters->options().warn_mismatch())
10985 {
10986 // Attribute numbers >=64 (mod 128) can be safely ignored. */
10987 if ((err_tag & 127) < 64)
10988 {
10989 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
10990 err_object, err_tag);
10991 }
10992 else
10993 {
10994 gold_warning(_("%s: unknown EABI object attribute %d"),
10995 err_object, err_tag);
10996 }
10997 }
10998 }
10999 }
11000
11001 // Stub-generation methods for Target_arm.
11002
11003 // Make a new Arm_input_section object.
11004
11005 template<bool big_endian>
11006 Arm_input_section<big_endian>*
11007 Target_arm<big_endian>::new_arm_input_section(
11008 Relobj* relobj,
11009 unsigned int shndx)
11010 {
11011 Section_id sid(relobj, shndx);
11012
11013 Arm_input_section<big_endian>* arm_input_section =
11014 new Arm_input_section<big_endian>(relobj, shndx);
11015 arm_input_section->init();
11016
11017 // Register new Arm_input_section in map for look-up.
11018 std::pair<typename Arm_input_section_map::iterator, bool> ins =
11019 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
11020
11021 // Make sure that it we have not created another Arm_input_section
11022 // for this input section already.
11023 gold_assert(ins.second);
11024
11025 return arm_input_section;
11026 }
11027
11028 // Find the Arm_input_section object corresponding to the SHNDX-th input
11029 // section of RELOBJ.
11030
11031 template<bool big_endian>
11032 Arm_input_section<big_endian>*
11033 Target_arm<big_endian>::find_arm_input_section(
11034 Relobj* relobj,
11035 unsigned int shndx) const
11036 {
11037 Section_id sid(relobj, shndx);
11038 typename Arm_input_section_map::const_iterator p =
11039 this->arm_input_section_map_.find(sid);
11040 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
11041 }
11042
11043 // Make a new stub table.
11044
11045 template<bool big_endian>
11046 Stub_table<big_endian>*
11047 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
11048 {
11049 Stub_table<big_endian>* stub_table =
11050 new Stub_table<big_endian>(owner);
11051 this->stub_tables_.push_back(stub_table);
11052
11053 stub_table->set_address(owner->address() + owner->data_size());
11054 stub_table->set_file_offset(owner->offset() + owner->data_size());
11055 stub_table->finalize_data_size();
11056
11057 return stub_table;
11058 }
11059
11060 // Scan a relocation for stub generation.
11061
11062 template<bool big_endian>
11063 void
11064 Target_arm<big_endian>::scan_reloc_for_stub(
11065 const Relocate_info<32, big_endian>* relinfo,
11066 unsigned int r_type,
11067 const Sized_symbol<32>* gsym,
11068 unsigned int r_sym,
11069 const Symbol_value<32>* psymval,
11070 elfcpp::Elf_types<32>::Elf_Swxword addend,
11071 Arm_address address)
11072 {
11073 const Arm_relobj<big_endian>* arm_relobj =
11074 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11075
11076 bool target_is_thumb;
11077 Symbol_value<32> symval;
11078 if (gsym != NULL)
11079 {
11080 // This is a global symbol. Determine if we use PLT and if the
11081 // final target is THUMB.
11082 if (gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
11083 {
11084 // This uses a PLT, change the symbol value.
11085 symval.set_output_value(this->plt_section()->address()
11086 + gsym->plt_offset());
11087 psymval = &symval;
11088 target_is_thumb = false;
11089 }
11090 else if (gsym->is_undefined())
11091 // There is no need to generate a stub symbol is undefined.
11092 return;
11093 else
11094 {
11095 target_is_thumb =
11096 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
11097 || (gsym->type() == elfcpp::STT_FUNC
11098 && !gsym->is_undefined()
11099 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
11100 }
11101 }
11102 else
11103 {
11104 // This is a local symbol. Determine if the final target is THUMB.
11105 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
11106 }
11107
11108 // Strip LSB if this points to a THUMB target.
11109 const Arm_reloc_property* reloc_property =
11110 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
11111 gold_assert(reloc_property != NULL);
11112 if (target_is_thumb
11113 && reloc_property->uses_thumb_bit()
11114 && ((psymval->value(arm_relobj, 0) & 1) != 0))
11115 {
11116 Arm_address stripped_value =
11117 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
11118 symval.set_output_value(stripped_value);
11119 psymval = &symval;
11120 }
11121
11122 // Get the symbol value.
11123 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
11124
11125 // Owing to pipelining, the PC relative branches below actually skip
11126 // two instructions when the branch offset is 0.
11127 Arm_address destination;
11128 switch (r_type)
11129 {
11130 case elfcpp::R_ARM_CALL:
11131 case elfcpp::R_ARM_JUMP24:
11132 case elfcpp::R_ARM_PLT32:
11133 // ARM branches.
11134 destination = value + addend + 8;
11135 break;
11136 case elfcpp::R_ARM_THM_CALL:
11137 case elfcpp::R_ARM_THM_XPC22:
11138 case elfcpp::R_ARM_THM_JUMP24:
11139 case elfcpp::R_ARM_THM_JUMP19:
11140 // THUMB branches.
11141 destination = value + addend + 4;
11142 break;
11143 default:
11144 gold_unreachable();
11145 }
11146
11147 Reloc_stub* stub = NULL;
11148 Stub_type stub_type =
11149 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
11150 target_is_thumb);
11151 if (stub_type != arm_stub_none)
11152 {
11153 // Try looking up an existing stub from a stub table.
11154 Stub_table<big_endian>* stub_table =
11155 arm_relobj->stub_table(relinfo->data_shndx);
11156 gold_assert(stub_table != NULL);
11157
11158 // Locate stub by destination.
11159 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
11160
11161 // Create a stub if there is not one already
11162 stub = stub_table->find_reloc_stub(stub_key);
11163 if (stub == NULL)
11164 {
11165 // create a new stub and add it to stub table.
11166 stub = this->stub_factory().make_reloc_stub(stub_type);
11167 stub_table->add_reloc_stub(stub, stub_key);
11168 }
11169
11170 // Record the destination address.
11171 stub->set_destination_address(destination
11172 | (target_is_thumb ? 1 : 0));
11173 }
11174
11175 // For Cortex-A8, we need to record a relocation at 4K page boundary.
11176 if (this->fix_cortex_a8_
11177 && (r_type == elfcpp::R_ARM_THM_JUMP24
11178 || r_type == elfcpp::R_ARM_THM_JUMP19
11179 || r_type == elfcpp::R_ARM_THM_CALL
11180 || r_type == elfcpp::R_ARM_THM_XPC22)
11181 && (address & 0xfffU) == 0xffeU)
11182 {
11183 // Found a candidate. Note we haven't checked the destination is
11184 // within 4K here: if we do so (and don't create a record) we can't
11185 // tell that a branch should have been relocated when scanning later.
11186 this->cortex_a8_relocs_info_[address] =
11187 new Cortex_a8_reloc(stub, r_type,
11188 destination | (target_is_thumb ? 1 : 0));
11189 }
11190 }
11191
11192 // This function scans a relocation sections for stub generation.
11193 // The template parameter Relocate must be a class type which provides
11194 // a single function, relocate(), which implements the machine
11195 // specific part of a relocation.
11196
11197 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
11198 // SHT_REL or SHT_RELA.
11199
11200 // PRELOCS points to the relocation data. RELOC_COUNT is the number
11201 // of relocs. OUTPUT_SECTION is the output section.
11202 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
11203 // mapped to output offsets.
11204
11205 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
11206 // VIEW_SIZE is the size. These refer to the input section, unless
11207 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
11208 // the output section.
11209
11210 template<bool big_endian>
11211 template<int sh_type>
11212 void inline
11213 Target_arm<big_endian>::scan_reloc_section_for_stubs(
11214 const Relocate_info<32, big_endian>* relinfo,
11215 const unsigned char* prelocs,
11216 size_t reloc_count,
11217 Output_section* output_section,
11218 bool needs_special_offset_handling,
11219 const unsigned char* view,
11220 elfcpp::Elf_types<32>::Elf_Addr view_address,
11221 section_size_type)
11222 {
11223 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
11224 const int reloc_size =
11225 Reloc_types<sh_type, 32, big_endian>::reloc_size;
11226
11227 Arm_relobj<big_endian>* arm_object =
11228 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
11229 unsigned int local_count = arm_object->local_symbol_count();
11230
11231 gold::Default_comdat_behavior default_comdat_behavior;
11232 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
11233
11234 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
11235 {
11236 Reltype reloc(prelocs);
11237
11238 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
11239 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
11240 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
11241
11242 r_type = this->get_real_reloc_type(r_type);
11243
11244 // Only a few relocation types need stubs.
11245 if ((r_type != elfcpp::R_ARM_CALL)
11246 && (r_type != elfcpp::R_ARM_JUMP24)
11247 && (r_type != elfcpp::R_ARM_PLT32)
11248 && (r_type != elfcpp::R_ARM_THM_CALL)
11249 && (r_type != elfcpp::R_ARM_THM_XPC22)
11250 && (r_type != elfcpp::R_ARM_THM_JUMP24)
11251 && (r_type != elfcpp::R_ARM_THM_JUMP19)
11252 && (r_type != elfcpp::R_ARM_V4BX))
11253 continue;
11254
11255 section_offset_type offset =
11256 convert_to_section_size_type(reloc.get_r_offset());
11257
11258 if (needs_special_offset_handling)
11259 {
11260 offset = output_section->output_offset(relinfo->object,
11261 relinfo->data_shndx,
11262 offset);
11263 if (offset == -1)
11264 continue;
11265 }
11266
11267 // Create a v4bx stub if --fix-v4bx-interworking is used.
11268 if (r_type == elfcpp::R_ARM_V4BX)
11269 {
11270 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
11271 {
11272 // Get the BX instruction.
11273 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
11274 const Valtype* wv =
11275 reinterpret_cast<const Valtype*>(view + offset);
11276 elfcpp::Elf_types<32>::Elf_Swxword insn =
11277 elfcpp::Swap<32, big_endian>::readval(wv);
11278 const uint32_t reg = (insn & 0xf);
11279
11280 if (reg < 0xf)
11281 {
11282 // Try looking up an existing stub from a stub table.
11283 Stub_table<big_endian>* stub_table =
11284 arm_object->stub_table(relinfo->data_shndx);
11285 gold_assert(stub_table != NULL);
11286
11287 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
11288 {
11289 // create a new stub and add it to stub table.
11290 Arm_v4bx_stub* stub =
11291 this->stub_factory().make_arm_v4bx_stub(reg);
11292 gold_assert(stub != NULL);
11293 stub_table->add_arm_v4bx_stub(stub);
11294 }
11295 }
11296 }
11297 continue;
11298 }
11299
11300 // Get the addend.
11301 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
11302 elfcpp::Elf_types<32>::Elf_Swxword addend =
11303 stub_addend_reader(r_type, view + offset, reloc);
11304
11305 const Sized_symbol<32>* sym;
11306
11307 Symbol_value<32> symval;
11308 const Symbol_value<32> *psymval;
11309 bool is_defined_in_discarded_section;
11310 unsigned int shndx;
11311 if (r_sym < local_count)
11312 {
11313 sym = NULL;
11314 psymval = arm_object->local_symbol(r_sym);
11315
11316 // If the local symbol belongs to a section we are discarding,
11317 // and that section is a debug section, try to find the
11318 // corresponding kept section and map this symbol to its
11319 // counterpart in the kept section. The symbol must not
11320 // correspond to a section we are folding.
11321 bool is_ordinary;
11322 shndx = psymval->input_shndx(&is_ordinary);
11323 is_defined_in_discarded_section =
11324 (is_ordinary
11325 && shndx != elfcpp::SHN_UNDEF
11326 && !arm_object->is_section_included(shndx)
11327 && !relinfo->symtab->is_section_folded(arm_object, shndx));
11328
11329 // We need to compute the would-be final value of this local
11330 // symbol.
11331 if (!is_defined_in_discarded_section)
11332 {
11333 typedef Sized_relobj_file<32, big_endian> ObjType;
11334 typename ObjType::Compute_final_local_value_status status =
11335 arm_object->compute_final_local_value(r_sym, psymval, &symval,
11336 relinfo->symtab);
11337 if (status == ObjType::CFLV_OK)
11338 {
11339 // Currently we cannot handle a branch to a target in
11340 // a merged section. If this is the case, issue an error
11341 // and also free the merge symbol value.
11342 if (!symval.has_output_value())
11343 {
11344 const std::string& section_name =
11345 arm_object->section_name(shndx);
11346 arm_object->error(_("cannot handle branch to local %u "
11347 "in a merged section %s"),
11348 r_sym, section_name.c_str());
11349 }
11350 psymval = &symval;
11351 }
11352 else
11353 {
11354 // We cannot determine the final value.
11355 continue;
11356 }
11357 }
11358 }
11359 else
11360 {
11361 const Symbol* gsym;
11362 gsym = arm_object->global_symbol(r_sym);
11363 gold_assert(gsym != NULL);
11364 if (gsym->is_forwarder())
11365 gsym = relinfo->symtab->resolve_forwards(gsym);
11366
11367 sym = static_cast<const Sized_symbol<32>*>(gsym);
11368 if (sym->has_symtab_index() && sym->symtab_index() != -1U)
11369 symval.set_output_symtab_index(sym->symtab_index());
11370 else
11371 symval.set_no_output_symtab_entry();
11372
11373 // We need to compute the would-be final value of this global
11374 // symbol.
11375 const Symbol_table* symtab = relinfo->symtab;
11376 const Sized_symbol<32>* sized_symbol =
11377 symtab->get_sized_symbol<32>(gsym);
11378 Symbol_table::Compute_final_value_status status;
11379 Arm_address value =
11380 symtab->compute_final_value<32>(sized_symbol, &status);
11381
11382 // Skip this if the symbol has not output section.
11383 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
11384 continue;
11385 symval.set_output_value(value);
11386
11387 if (gsym->type() == elfcpp::STT_TLS)
11388 symval.set_is_tls_symbol();
11389 else if (gsym->type() == elfcpp::STT_GNU_IFUNC)
11390 symval.set_is_ifunc_symbol();
11391 psymval = &symval;
11392
11393 is_defined_in_discarded_section =
11394 (gsym->is_defined_in_discarded_section()
11395 && gsym->is_undefined());
11396 shndx = 0;
11397 }
11398
11399 Symbol_value<32> symval2;
11400 if (is_defined_in_discarded_section)
11401 {
11402 if (comdat_behavior == CB_UNDETERMINED)
11403 {
11404 std::string name = arm_object->section_name(relinfo->data_shndx);
11405 comdat_behavior = default_comdat_behavior.get(name.c_str());
11406 }
11407 if (comdat_behavior == CB_PRETEND)
11408 {
11409 // FIXME: This case does not work for global symbols.
11410 // We have no place to store the original section index.
11411 // Fortunately this does not matter for comdat sections,
11412 // only for sections explicitly discarded by a linker
11413 // script.
11414 bool found;
11415 typename elfcpp::Elf_types<32>::Elf_Addr value =
11416 arm_object->map_to_kept_section(shndx, &found);
11417 if (found)
11418 symval2.set_output_value(value + psymval->input_value());
11419 else
11420 symval2.set_output_value(0);
11421 }
11422 else
11423 {
11424 if (comdat_behavior == CB_WARNING)
11425 gold_warning_at_location(relinfo, i, offset,
11426 _("relocation refers to discarded "
11427 "section"));
11428 symval2.set_output_value(0);
11429 }
11430 symval2.set_no_output_symtab_entry();
11431 psymval = &symval2;
11432 }
11433
11434 // If symbol is a section symbol, we don't know the actual type of
11435 // destination. Give up.
11436 if (psymval->is_section_symbol())
11437 continue;
11438
11439 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
11440 addend, view_address + offset);
11441 }
11442 }
11443
11444 // Scan an input section for stub generation.
11445
11446 template<bool big_endian>
11447 void
11448 Target_arm<big_endian>::scan_section_for_stubs(
11449 const Relocate_info<32, big_endian>* relinfo,
11450 unsigned int sh_type,
11451 const unsigned char* prelocs,
11452 size_t reloc_count,
11453 Output_section* output_section,
11454 bool needs_special_offset_handling,
11455 const unsigned char* view,
11456 Arm_address view_address,
11457 section_size_type view_size)
11458 {
11459 if (sh_type == elfcpp::SHT_REL)
11460 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
11461 relinfo,
11462 prelocs,
11463 reloc_count,
11464 output_section,
11465 needs_special_offset_handling,
11466 view,
11467 view_address,
11468 view_size);
11469 else if (sh_type == elfcpp::SHT_RELA)
11470 // We do not support RELA type relocations yet. This is provided for
11471 // completeness.
11472 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
11473 relinfo,
11474 prelocs,
11475 reloc_count,
11476 output_section,
11477 needs_special_offset_handling,
11478 view,
11479 view_address,
11480 view_size);
11481 else
11482 gold_unreachable();
11483 }
11484
11485 // Group input sections for stub generation.
11486 //
11487 // We group input sections in an output section so that the total size,
11488 // including any padding space due to alignment is smaller than GROUP_SIZE
11489 // unless the only input section in group is bigger than GROUP_SIZE already.
11490 // Then an ARM stub table is created to follow the last input section
11491 // in group. For each group an ARM stub table is created an is placed
11492 // after the last group. If STUB_ALWAYS_AFTER_BRANCH is false, we further
11493 // extend the group after the stub table.
11494
11495 template<bool big_endian>
11496 void
11497 Target_arm<big_endian>::group_sections(
11498 Layout* layout,
11499 section_size_type group_size,
11500 bool stubs_always_after_branch,
11501 const Task* task)
11502 {
11503 // Group input sections and insert stub table
11504 Layout::Section_list section_list;
11505 layout->get_executable_sections(&section_list);
11506 for (Layout::Section_list::const_iterator p = section_list.begin();
11507 p != section_list.end();
11508 ++p)
11509 {
11510 Arm_output_section<big_endian>* output_section =
11511 Arm_output_section<big_endian>::as_arm_output_section(*p);
11512 output_section->group_sections(group_size, stubs_always_after_branch,
11513 this, task);
11514 }
11515 }
11516
11517 // Relaxation hook. This is where we do stub generation.
11518
11519 template<bool big_endian>
11520 bool
11521 Target_arm<big_endian>::do_relax(
11522 int pass,
11523 const Input_objects* input_objects,
11524 Symbol_table* symtab,
11525 Layout* layout,
11526 const Task* task)
11527 {
11528 // No need to generate stubs if this is a relocatable link.
11529 gold_assert(!parameters->options().relocatable());
11530
11531 // If this is the first pass, we need to group input sections into
11532 // stub groups.
11533 bool done_exidx_fixup = false;
11534 typedef typename Stub_table_list::iterator Stub_table_iterator;
11535 if (pass == 1)
11536 {
11537 // Determine the stub group size. The group size is the absolute
11538 // value of the parameter --stub-group-size. If --stub-group-size
11539 // is passed a negative value, we restrict stubs to be always after
11540 // the stubbed branches.
11541 int32_t stub_group_size_param =
11542 parameters->options().stub_group_size();
11543 bool stubs_always_after_branch = stub_group_size_param < 0;
11544 section_size_type stub_group_size = abs(stub_group_size_param);
11545
11546 if (stub_group_size == 1)
11547 {
11548 // Default value.
11549 // Thumb branch range is +-4MB has to be used as the default
11550 // maximum size (a given section can contain both ARM and Thumb
11551 // code, so the worst case has to be taken into account). If we are
11552 // fixing cortex-a8 errata, the branch range has to be even smaller,
11553 // since wide conditional branch has a range of +-1MB only.
11554 //
11555 // This value is 48K less than that, which allows for 4096
11556 // 12-byte stubs. If we exceed that, then we will fail to link.
11557 // The user will have to relink with an explicit group size
11558 // option.
11559 stub_group_size = 4145152;
11560 }
11561
11562 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
11563 // page as the first half of a 32-bit branch straddling two 4K pages.
11564 // This is a crude way of enforcing that. In addition, long conditional
11565 // branches of THUMB-2 have a range of +-1M. If we are fixing cortex-A8
11566 // erratum, limit the group size to (1M - 12k) to avoid unreachable
11567 // cortex-A8 stubs from long conditional branches.
11568 if (this->fix_cortex_a8_)
11569 {
11570 stubs_always_after_branch = true;
11571 const section_size_type cortex_a8_group_size = 1024 * (1024 - 12);
11572 stub_group_size = std::max(stub_group_size, cortex_a8_group_size);
11573 }
11574
11575 group_sections(layout, stub_group_size, stubs_always_after_branch, task);
11576
11577 // Also fix .ARM.exidx section coverage.
11578 Arm_output_section<big_endian>* exidx_output_section = NULL;
11579 for (Layout::Section_list::const_iterator p =
11580 layout->section_list().begin();
11581 p != layout->section_list().end();
11582 ++p)
11583 if ((*p)->type() == elfcpp::SHT_ARM_EXIDX)
11584 {
11585 if (exidx_output_section == NULL)
11586 exidx_output_section =
11587 Arm_output_section<big_endian>::as_arm_output_section(*p);
11588 else
11589 // We cannot handle this now.
11590 gold_error(_("multiple SHT_ARM_EXIDX sections %s and %s in a "
11591 "non-relocatable link"),
11592 exidx_output_section->name(),
11593 (*p)->name());
11594 }
11595
11596 if (exidx_output_section != NULL)
11597 {
11598 this->fix_exidx_coverage(layout, input_objects, exidx_output_section,
11599 symtab, task);
11600 done_exidx_fixup = true;
11601 }
11602 }
11603 else
11604 {
11605 // If this is not the first pass, addresses and file offsets have
11606 // been reset at this point, set them here.
11607 for (Stub_table_iterator sp = this->stub_tables_.begin();
11608 sp != this->stub_tables_.end();
11609 ++sp)
11610 {
11611 Arm_input_section<big_endian>* owner = (*sp)->owner();
11612 off_t off = align_address(owner->original_size(),
11613 (*sp)->addralign());
11614 (*sp)->set_address_and_file_offset(owner->address() + off,
11615 owner->offset() + off);
11616 }
11617 }
11618
11619 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
11620 // beginning of each relaxation pass, just blow away all the stubs.
11621 // Alternatively, we could selectively remove only the stubs and reloc
11622 // information for code sections that have moved since the last pass.
11623 // That would require more book-keeping.
11624 if (this->fix_cortex_a8_)
11625 {
11626 // Clear all Cortex-A8 reloc information.
11627 for (typename Cortex_a8_relocs_info::const_iterator p =
11628 this->cortex_a8_relocs_info_.begin();
11629 p != this->cortex_a8_relocs_info_.end();
11630 ++p)
11631 delete p->second;
11632 this->cortex_a8_relocs_info_.clear();
11633
11634 // Remove all Cortex-A8 stubs.
11635 for (Stub_table_iterator sp = this->stub_tables_.begin();
11636 sp != this->stub_tables_.end();
11637 ++sp)
11638 (*sp)->remove_all_cortex_a8_stubs();
11639 }
11640
11641 // Scan relocs for relocation stubs
11642 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11643 op != input_objects->relobj_end();
11644 ++op)
11645 {
11646 Arm_relobj<big_endian>* arm_relobj =
11647 Arm_relobj<big_endian>::as_arm_relobj(*op);
11648 // Lock the object so we can read from it. This is only called
11649 // single-threaded from Layout::finalize, so it is OK to lock.
11650 Task_lock_obj<Object> tl(task, arm_relobj);
11651 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
11652 }
11653
11654 // Check all stub tables to see if any of them have their data sizes
11655 // or addresses alignments changed. These are the only things that
11656 // matter.
11657 bool any_stub_table_changed = false;
11658 Unordered_set<const Output_section*> sections_needing_adjustment;
11659 for (Stub_table_iterator sp = this->stub_tables_.begin();
11660 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11661 ++sp)
11662 {
11663 if ((*sp)->update_data_size_and_addralign())
11664 {
11665 // Update data size of stub table owner.
11666 Arm_input_section<big_endian>* owner = (*sp)->owner();
11667 uint64_t address = owner->address();
11668 off_t offset = owner->offset();
11669 owner->reset_address_and_file_offset();
11670 owner->set_address_and_file_offset(address, offset);
11671
11672 sections_needing_adjustment.insert(owner->output_section());
11673 any_stub_table_changed = true;
11674 }
11675 }
11676
11677 // Output_section_data::output_section() returns a const pointer but we
11678 // need to update output sections, so we record all output sections needing
11679 // update above and scan the sections here to find out what sections need
11680 // to be updated.
11681 for (Layout::Section_list::const_iterator p = layout->section_list().begin();
11682 p != layout->section_list().end();
11683 ++p)
11684 {
11685 if (sections_needing_adjustment.find(*p)
11686 != sections_needing_adjustment.end())
11687 (*p)->set_section_offsets_need_adjustment();
11688 }
11689
11690 // Stop relaxation if no EXIDX fix-up and no stub table change.
11691 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
11692
11693 // Finalize the stubs in the last relaxation pass.
11694 if (!continue_relaxation)
11695 {
11696 for (Stub_table_iterator sp = this->stub_tables_.begin();
11697 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
11698 ++sp)
11699 (*sp)->finalize_stubs();
11700
11701 // Update output local symbol counts of objects if necessary.
11702 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
11703 op != input_objects->relobj_end();
11704 ++op)
11705 {
11706 Arm_relobj<big_endian>* arm_relobj =
11707 Arm_relobj<big_endian>::as_arm_relobj(*op);
11708
11709 // Update output local symbol counts. We need to discard local
11710 // symbols defined in parts of input sections that are discarded by
11711 // relaxation.
11712 if (arm_relobj->output_local_symbol_count_needs_update())
11713 {
11714 // We need to lock the object's file to update it.
11715 Task_lock_obj<Object> tl(task, arm_relobj);
11716 arm_relobj->update_output_local_symbol_count();
11717 }
11718 }
11719 }
11720
11721 return continue_relaxation;
11722 }
11723
11724 // Relocate a stub.
11725
11726 template<bool big_endian>
11727 void
11728 Target_arm<big_endian>::relocate_stub(
11729 Stub* stub,
11730 const Relocate_info<32, big_endian>* relinfo,
11731 Output_section* output_section,
11732 unsigned char* view,
11733 Arm_address address,
11734 section_size_type view_size)
11735 {
11736 Relocate relocate;
11737 const Stub_template* stub_template = stub->stub_template();
11738 for (size_t i = 0; i < stub_template->reloc_count(); i++)
11739 {
11740 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
11741 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
11742
11743 unsigned int r_type = insn->r_type();
11744 section_size_type reloc_offset = stub_template->reloc_offset(i);
11745 section_size_type reloc_size = insn->size();
11746 gold_assert(reloc_offset + reloc_size <= view_size);
11747
11748 // This is the address of the stub destination.
11749 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
11750 Symbol_value<32> symval;
11751 symval.set_output_value(target);
11752
11753 // Synthesize a fake reloc just in case. We don't have a symbol so
11754 // we use 0.
11755 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
11756 memset(reloc_buffer, 0, sizeof(reloc_buffer));
11757 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
11758 reloc_write.put_r_offset(reloc_offset);
11759 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
11760 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
11761
11762 relocate.relocate(relinfo, this, output_section,
11763 this->fake_relnum_for_stubs, rel, r_type,
11764 NULL, &symval, view + reloc_offset,
11765 address + reloc_offset, reloc_size);
11766 }
11767 }
11768
11769 // Determine whether an object attribute tag takes an integer, a
11770 // string or both.
11771
11772 template<bool big_endian>
11773 int
11774 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
11775 {
11776 if (tag == Object_attribute::Tag_compatibility)
11777 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11778 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
11779 else if (tag == elfcpp::Tag_nodefaults)
11780 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
11781 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
11782 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
11783 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
11784 else if (tag < 32)
11785 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
11786 else
11787 return ((tag & 1) != 0
11788 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
11789 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
11790 }
11791
11792 // Reorder attributes.
11793 //
11794 // The ABI defines that Tag_conformance should be emitted first, and that
11795 // Tag_nodefaults should be second (if either is defined). This sets those
11796 // two positions, and bumps up the position of all the remaining tags to
11797 // compensate.
11798
11799 template<bool big_endian>
11800 int
11801 Target_arm<big_endian>::do_attributes_order(int num) const
11802 {
11803 // Reorder the known object attributes in output. We want to move
11804 // Tag_conformance to position 4 and Tag_conformance to position 5
11805 // and shift everything between 4 .. Tag_conformance - 1 to make room.
11806 if (num == 4)
11807 return elfcpp::Tag_conformance;
11808 if (num == 5)
11809 return elfcpp::Tag_nodefaults;
11810 if ((num - 2) < elfcpp::Tag_nodefaults)
11811 return num - 2;
11812 if ((num - 1) < elfcpp::Tag_conformance)
11813 return num - 1;
11814 return num;
11815 }
11816
11817 // Scan a span of THUMB code for Cortex-A8 erratum.
11818
11819 template<bool big_endian>
11820 void
11821 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
11822 Arm_relobj<big_endian>* arm_relobj,
11823 unsigned int shndx,
11824 section_size_type span_start,
11825 section_size_type span_end,
11826 const unsigned char* view,
11827 Arm_address address)
11828 {
11829 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
11830 //
11831 // The opcode is BLX.W, BL.W, B.W, Bcc.W
11832 // The branch target is in the same 4KB region as the
11833 // first half of the branch.
11834 // The instruction before the branch is a 32-bit
11835 // length non-branch instruction.
11836 section_size_type i = span_start;
11837 bool last_was_32bit = false;
11838 bool last_was_branch = false;
11839 while (i < span_end)
11840 {
11841 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11842 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
11843 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
11844 bool is_blx = false, is_b = false;
11845 bool is_bl = false, is_bcc = false;
11846
11847 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
11848 if (insn_32bit)
11849 {
11850 // Load the rest of the insn (in manual-friendly order).
11851 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
11852
11853 // Encoding T4: B<c>.W.
11854 is_b = (insn & 0xf800d000U) == 0xf0009000U;
11855 // Encoding T1: BL<c>.W.
11856 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
11857 // Encoding T2: BLX<c>.W.
11858 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
11859 // Encoding T3: B<c>.W (not permitted in IT block).
11860 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
11861 && (insn & 0x07f00000U) != 0x03800000U);
11862 }
11863
11864 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
11865
11866 // If this instruction is a 32-bit THUMB branch that crosses a 4K
11867 // page boundary and it follows 32-bit non-branch instruction,
11868 // we need to work around.
11869 if (is_32bit_branch
11870 && ((address + i) & 0xfffU) == 0xffeU
11871 && last_was_32bit
11872 && !last_was_branch)
11873 {
11874 // Check to see if there is a relocation stub for this branch.
11875 bool force_target_arm = false;
11876 bool force_target_thumb = false;
11877 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
11878 Cortex_a8_relocs_info::const_iterator p =
11879 this->cortex_a8_relocs_info_.find(address + i);
11880
11881 if (p != this->cortex_a8_relocs_info_.end())
11882 {
11883 cortex_a8_reloc = p->second;
11884 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
11885
11886 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11887 && !target_is_thumb)
11888 force_target_arm = true;
11889 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
11890 && target_is_thumb)
11891 force_target_thumb = true;
11892 }
11893
11894 off_t offset;
11895 Stub_type stub_type = arm_stub_none;
11896
11897 // Check if we have an offending branch instruction.
11898 uint16_t upper_insn = (insn >> 16) & 0xffffU;
11899 uint16_t lower_insn = insn & 0xffffU;
11900 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
11901
11902 if (cortex_a8_reloc != NULL
11903 && cortex_a8_reloc->reloc_stub() != NULL)
11904 // We've already made a stub for this instruction, e.g.
11905 // it's a long branch or a Thumb->ARM stub. Assume that
11906 // stub will suffice to work around the A8 erratum (see
11907 // setting of always_after_branch above).
11908 ;
11909 else if (is_bcc)
11910 {
11911 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
11912 lower_insn);
11913 stub_type = arm_stub_a8_veneer_b_cond;
11914 }
11915 else if (is_b || is_bl || is_blx)
11916 {
11917 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
11918 lower_insn);
11919 if (is_blx)
11920 offset &= ~3;
11921
11922 stub_type = (is_blx
11923 ? arm_stub_a8_veneer_blx
11924 : (is_bl
11925 ? arm_stub_a8_veneer_bl
11926 : arm_stub_a8_veneer_b));
11927 }
11928
11929 if (stub_type != arm_stub_none)
11930 {
11931 Arm_address pc_for_insn = address + i + 4;
11932
11933 // The original instruction is a BL, but the target is
11934 // an ARM instruction. If we were not making a stub,
11935 // the BL would have been converted to a BLX. Use the
11936 // BLX stub instead in that case.
11937 if (this->may_use_v5t_interworking() && force_target_arm
11938 && stub_type == arm_stub_a8_veneer_bl)
11939 {
11940 stub_type = arm_stub_a8_veneer_blx;
11941 is_blx = true;
11942 is_bl = false;
11943 }
11944 // Conversely, if the original instruction was
11945 // BLX but the target is Thumb mode, use the BL stub.
11946 else if (force_target_thumb
11947 && stub_type == arm_stub_a8_veneer_blx)
11948 {
11949 stub_type = arm_stub_a8_veneer_bl;
11950 is_blx = false;
11951 is_bl = true;
11952 }
11953
11954 if (is_blx)
11955 pc_for_insn &= ~3;
11956
11957 // If we found a relocation, use the proper destination,
11958 // not the offset in the (unrelocated) instruction.
11959 // Note this is always done if we switched the stub type above.
11960 if (cortex_a8_reloc != NULL)
11961 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
11962
11963 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
11964
11965 // Add a new stub if destination address in in the same page.
11966 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
11967 {
11968 Cortex_a8_stub* stub =
11969 this->stub_factory_.make_cortex_a8_stub(stub_type,
11970 arm_relobj, shndx,
11971 address + i,
11972 target, insn);
11973 Stub_table<big_endian>* stub_table =
11974 arm_relobj->stub_table(shndx);
11975 gold_assert(stub_table != NULL);
11976 stub_table->add_cortex_a8_stub(address + i, stub);
11977 }
11978 }
11979 }
11980
11981 i += insn_32bit ? 4 : 2;
11982 last_was_32bit = insn_32bit;
11983 last_was_branch = is_32bit_branch;
11984 }
11985 }
11986
11987 // Apply the Cortex-A8 workaround.
11988
11989 template<bool big_endian>
11990 void
11991 Target_arm<big_endian>::apply_cortex_a8_workaround(
11992 const Cortex_a8_stub* stub,
11993 Arm_address stub_address,
11994 unsigned char* insn_view,
11995 Arm_address insn_address)
11996 {
11997 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
11998 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
11999 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
12000 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
12001 off_t branch_offset = stub_address - (insn_address + 4);
12002
12003 typedef class Arm_relocate_functions<big_endian> RelocFuncs;
12004 switch (stub->stub_template()->type())
12005 {
12006 case arm_stub_a8_veneer_b_cond:
12007 // For a conditional branch, we re-write it to be an unconditional
12008 // branch to the stub. We use the THUMB-2 encoding here.
12009 upper_insn = 0xf000U;
12010 lower_insn = 0xb800U;
12011 // Fall through
12012 case arm_stub_a8_veneer_b:
12013 case arm_stub_a8_veneer_bl:
12014 case arm_stub_a8_veneer_blx:
12015 if ((lower_insn & 0x5000U) == 0x4000U)
12016 // For a BLX instruction, make sure that the relocation is
12017 // rounded up to a word boundary. This follows the semantics of
12018 // the instruction which specifies that bit 1 of the target
12019 // address will come from bit 1 of the base address.
12020 branch_offset = (branch_offset + 2) & ~3;
12021
12022 // Put BRANCH_OFFSET back into the insn.
12023 gold_assert(!Bits<25>::has_overflow32(branch_offset));
12024 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
12025 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
12026 break;
12027
12028 default:
12029 gold_unreachable();
12030 }
12031
12032 // Put the relocated value back in the object file:
12033 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
12034 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
12035 }
12036
12037 // Target selector for ARM. Note this is never instantiated directly.
12038 // It's only used in Target_selector_arm_nacl, below.
12039
12040 template<bool big_endian>
12041 class Target_selector_arm : public Target_selector
12042 {
12043 public:
12044 Target_selector_arm()
12045 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
12046 (big_endian ? "elf32-bigarm" : "elf32-littlearm"),
12047 (big_endian ? "armelfb" : "armelf"))
12048 { }
12049
12050 Target*
12051 do_instantiate_target()
12052 { return new Target_arm<big_endian>(); }
12053 };
12054
12055 // Fix .ARM.exidx section coverage.
12056
12057 template<bool big_endian>
12058 void
12059 Target_arm<big_endian>::fix_exidx_coverage(
12060 Layout* layout,
12061 const Input_objects* input_objects,
12062 Arm_output_section<big_endian>* exidx_section,
12063 Symbol_table* symtab,
12064 const Task* task)
12065 {
12066 // We need to look at all the input sections in output in ascending
12067 // order of of output address. We do that by building a sorted list
12068 // of output sections by addresses. Then we looks at the output sections
12069 // in order. The input sections in an output section are already sorted
12070 // by addresses within the output section.
12071
12072 typedef std::set<Output_section*, output_section_address_less_than>
12073 Sorted_output_section_list;
12074 Sorted_output_section_list sorted_output_sections;
12075
12076 // Find out all the output sections of input sections pointed by
12077 // EXIDX input sections.
12078 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
12079 p != input_objects->relobj_end();
12080 ++p)
12081 {
12082 Arm_relobj<big_endian>* arm_relobj =
12083 Arm_relobj<big_endian>::as_arm_relobj(*p);
12084 std::vector<unsigned int> shndx_list;
12085 arm_relobj->get_exidx_shndx_list(&shndx_list);
12086 for (size_t i = 0; i < shndx_list.size(); ++i)
12087 {
12088 const Arm_exidx_input_section* exidx_input_section =
12089 arm_relobj->exidx_input_section_by_shndx(shndx_list[i]);
12090 gold_assert(exidx_input_section != NULL);
12091 if (!exidx_input_section->has_errors())
12092 {
12093 unsigned int text_shndx = exidx_input_section->link();
12094 Output_section* os = arm_relobj->output_section(text_shndx);
12095 if (os != NULL && (os->flags() & elfcpp::SHF_ALLOC) != 0)
12096 sorted_output_sections.insert(os);
12097 }
12098 }
12099 }
12100
12101 // Go over the output sections in ascending order of output addresses.
12102 typedef typename Arm_output_section<big_endian>::Text_section_list
12103 Text_section_list;
12104 Text_section_list sorted_text_sections;
12105 for (typename Sorted_output_section_list::iterator p =
12106 sorted_output_sections.begin();
12107 p != sorted_output_sections.end();
12108 ++p)
12109 {
12110 Arm_output_section<big_endian>* arm_output_section =
12111 Arm_output_section<big_endian>::as_arm_output_section(*p);
12112 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
12113 }
12114
12115 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab,
12116 merge_exidx_entries(), task);
12117 }
12118
12119 template<bool big_endian>
12120 void
12121 Target_arm<big_endian>::do_define_standard_symbols(
12122 Symbol_table* symtab,
12123 Layout* layout)
12124 {
12125 // Handle the .ARM.exidx section.
12126 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
12127
12128 if (exidx_section != NULL)
12129 {
12130 // Create __exidx_start and __exidx_end symbols.
12131 symtab->define_in_output_data("__exidx_start",
12132 NULL, // version
12133 Symbol_table::PREDEFINED,
12134 exidx_section,
12135 0, // value
12136 0, // symsize
12137 elfcpp::STT_NOTYPE,
12138 elfcpp::STB_GLOBAL,
12139 elfcpp::STV_HIDDEN,
12140 0, // nonvis
12141 false, // offset_is_from_end
12142 true); // only_if_ref
12143
12144 symtab->define_in_output_data("__exidx_end",
12145 NULL, // version
12146 Symbol_table::PREDEFINED,
12147 exidx_section,
12148 0, // value
12149 0, // symsize
12150 elfcpp::STT_NOTYPE,
12151 elfcpp::STB_GLOBAL,
12152 elfcpp::STV_HIDDEN,
12153 0, // nonvis
12154 true, // offset_is_from_end
12155 true); // only_if_ref
12156 }
12157 else
12158 {
12159 // Define __exidx_start and __exidx_end even when .ARM.exidx
12160 // section is missing to match ld's behaviour.
12161 symtab->define_as_constant("__exidx_start", NULL,
12162 Symbol_table::PREDEFINED,
12163 0, 0, elfcpp::STT_OBJECT,
12164 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12165 true, false);
12166 symtab->define_as_constant("__exidx_end", NULL,
12167 Symbol_table::PREDEFINED,
12168 0, 0, elfcpp::STT_OBJECT,
12169 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
12170 true, false);
12171 }
12172 }
12173
12174 // NaCl variant. It uses different PLT contents.
12175
12176 template<bool big_endian>
12177 class Output_data_plt_arm_nacl;
12178
12179 template<bool big_endian>
12180 class Target_arm_nacl : public Target_arm<big_endian>
12181 {
12182 public:
12183 Target_arm_nacl()
12184 : Target_arm<big_endian>(&arm_nacl_info)
12185 { }
12186
12187 protected:
12188 virtual Output_data_plt_arm<big_endian>*
12189 do_make_data_plt(Layout* layout, Output_data_space* got_plt)
12190 { return new Output_data_plt_arm_nacl<big_endian>(layout, got_plt); }
12191
12192 private:
12193 static const Target::Target_info arm_nacl_info;
12194 };
12195
12196 template<bool big_endian>
12197 const Target::Target_info Target_arm_nacl<big_endian>::arm_nacl_info =
12198 {
12199 32, // size
12200 big_endian, // is_big_endian
12201 elfcpp::EM_ARM, // machine_code
12202 false, // has_make_symbol
12203 false, // has_resolve
12204 false, // has_code_fill
12205 true, // is_default_stack_executable
12206 false, // can_icf_inline_merge_sections
12207 '\0', // wrap_char
12208 "/lib/ld-nacl-arm.so.1", // dynamic_linker
12209 0x20000, // default_text_segment_address
12210 0x10000, // abi_pagesize (overridable by -z max-page-size)
12211 0x10000, // common_pagesize (overridable by -z common-page-size)
12212 true, // isolate_execinstr
12213 0x10000000, // rosegment_gap
12214 elfcpp::SHN_UNDEF, // small_common_shndx
12215 elfcpp::SHN_UNDEF, // large_common_shndx
12216 0, // small_common_section_flags
12217 0, // large_common_section_flags
12218 ".ARM.attributes", // attributes_section
12219 "aeabi" // attributes_vendor
12220 };
12221
12222 template<bool big_endian>
12223 class Output_data_plt_arm_nacl : public Output_data_plt_arm<big_endian>
12224 {
12225 public:
12226 Output_data_plt_arm_nacl(Layout* layout, Output_data_space* got_plt)
12227 : Output_data_plt_arm<big_endian>(layout, 16, got_plt)
12228 { }
12229
12230 protected:
12231 // Return the offset of the first non-reserved PLT entry.
12232 virtual unsigned int
12233 do_first_plt_entry_offset() const
12234 { return sizeof(first_plt_entry); }
12235
12236 // Return the size of a PLT entry.
12237 virtual unsigned int
12238 do_get_plt_entry_size() const
12239 { return sizeof(plt_entry); }
12240
12241 virtual void
12242 do_fill_first_plt_entry(unsigned char* pov,
12243 Arm_address got_address,
12244 Arm_address plt_address);
12245
12246 virtual void
12247 do_fill_plt_entry(unsigned char* pov,
12248 Arm_address got_address,
12249 Arm_address plt_address,
12250 unsigned int got_offset,
12251 unsigned int plt_offset);
12252
12253 private:
12254 inline uint32_t arm_movw_immediate(uint32_t value)
12255 {
12256 return (value & 0x00000fff) | ((value & 0x0000f000) << 4);
12257 }
12258
12259 inline uint32_t arm_movt_immediate(uint32_t value)
12260 {
12261 return ((value & 0x0fff0000) >> 16) | ((value & 0xf0000000) >> 12);
12262 }
12263
12264 // Template for the first PLT entry.
12265 static const uint32_t first_plt_entry[16];
12266
12267 // Template for subsequent PLT entries.
12268 static const uint32_t plt_entry[4];
12269 };
12270
12271 // The first entry in the PLT.
12272 template<bool big_endian>
12273 const uint32_t Output_data_plt_arm_nacl<big_endian>::first_plt_entry[16] =
12274 {
12275 // First bundle:
12276 0xe300c000, // movw ip, #:lower16:&GOT[2]-.+8
12277 0xe340c000, // movt ip, #:upper16:&GOT[2]-.+8
12278 0xe08cc00f, // add ip, ip, pc
12279 0xe52dc008, // str ip, [sp, #-8]!
12280 // Second bundle:
12281 0xe3ccc103, // bic ip, ip, #0xc0000000
12282 0xe59cc000, // ldr ip, [ip]
12283 0xe3ccc13f, // bic ip, ip, #0xc000000f
12284 0xe12fff1c, // bx ip
12285 // Third bundle:
12286 0xe320f000, // nop
12287 0xe320f000, // nop
12288 0xe320f000, // nop
12289 // .Lplt_tail:
12290 0xe50dc004, // str ip, [sp, #-4]
12291 // Fourth bundle:
12292 0xe3ccc103, // bic ip, ip, #0xc0000000
12293 0xe59cc000, // ldr ip, [ip]
12294 0xe3ccc13f, // bic ip, ip, #0xc000000f
12295 0xe12fff1c, // bx ip
12296 };
12297
12298 template<bool big_endian>
12299 void
12300 Output_data_plt_arm_nacl<big_endian>::do_fill_first_plt_entry(
12301 unsigned char* pov,
12302 Arm_address got_address,
12303 Arm_address plt_address)
12304 {
12305 // Write first PLT entry. All but first two words are constants.
12306 const size_t num_first_plt_words = (sizeof(first_plt_entry)
12307 / sizeof(first_plt_entry[0]));
12308
12309 int32_t got_displacement = got_address + 8 - (plt_address + 16);
12310
12311 elfcpp::Swap<32, big_endian>::writeval
12312 (pov + 0, first_plt_entry[0] | arm_movw_immediate (got_displacement));
12313 elfcpp::Swap<32, big_endian>::writeval
12314 (pov + 4, first_plt_entry[1] | arm_movt_immediate (got_displacement));
12315
12316 for (size_t i = 2; i < num_first_plt_words; ++i)
12317 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
12318 }
12319
12320 // Subsequent entries in the PLT.
12321
12322 template<bool big_endian>
12323 const uint32_t Output_data_plt_arm_nacl<big_endian>::plt_entry[4] =
12324 {
12325 0xe300c000, // movw ip, #:lower16:&GOT[n]-.+8
12326 0xe340c000, // movt ip, #:upper16:&GOT[n]-.+8
12327 0xe08cc00f, // add ip, ip, pc
12328 0xea000000, // b .Lplt_tail
12329 };
12330
12331 template<bool big_endian>
12332 void
12333 Output_data_plt_arm_nacl<big_endian>::do_fill_plt_entry(
12334 unsigned char* pov,
12335 Arm_address got_address,
12336 Arm_address plt_address,
12337 unsigned int got_offset,
12338 unsigned int plt_offset)
12339 {
12340 // Calculate the displacement between the PLT slot and the
12341 // common tail that's part of the special initial PLT slot.
12342 int32_t tail_displacement = (plt_address + (11 * sizeof(uint32_t))
12343 - (plt_address + plt_offset
12344 + sizeof(plt_entry) + sizeof(uint32_t)));
12345 gold_assert((tail_displacement & 3) == 0);
12346 tail_displacement >>= 2;
12347
12348 gold_assert ((tail_displacement & 0xff000000) == 0
12349 || (-tail_displacement & 0xff000000) == 0);
12350
12351 // Calculate the displacement between the PLT slot and the entry
12352 // in the GOT. The offset accounts for the value produced by
12353 // adding to pc in the penultimate instruction of the PLT stub.
12354 const int32_t got_displacement = (got_address + got_offset
12355 - (plt_address + sizeof(plt_entry)));
12356
12357 elfcpp::Swap<32, big_endian>::writeval
12358 (pov + 0, plt_entry[0] | arm_movw_immediate (got_displacement));
12359 elfcpp::Swap<32, big_endian>::writeval
12360 (pov + 4, plt_entry[1] | arm_movt_immediate (got_displacement));
12361 elfcpp::Swap<32, big_endian>::writeval
12362 (pov + 8, plt_entry[2]);
12363 elfcpp::Swap<32, big_endian>::writeval
12364 (pov + 12, plt_entry[3] | (tail_displacement & 0x00ffffff));
12365 }
12366
12367 // Target selectors.
12368
12369 template<bool big_endian>
12370 class Target_selector_arm_nacl
12371 : public Target_selector_nacl<Target_selector_arm<big_endian>,
12372 Target_arm_nacl<big_endian> >
12373 {
12374 public:
12375 Target_selector_arm_nacl()
12376 : Target_selector_nacl<Target_selector_arm<big_endian>,
12377 Target_arm_nacl<big_endian> >(
12378 "arm",
12379 big_endian ? "elf32-bigarm-nacl" : "elf32-littlearm-nacl",
12380 big_endian ? "armelfb_nacl" : "armelf_nacl")
12381 { }
12382 };
12383
12384 Target_selector_arm_nacl<false> target_selector_arm;
12385 Target_selector_arm_nacl<true> target_selector_armbe;
12386
12387 } // End anonymous namespace.
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