1 // arm.cc -- arm target support for gold.
3 // Copyright 2009, 2010 Free Software Foundation, Inc.
4 // Written by Doug Kwan <dougkwan@google.com> based on the i386 code
5 // by Ian Lance Taylor <iant@google.com>.
6 // This file also contains borrowed and adapted code from
9 // This file is part of gold.
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.
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.
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.
38 #include "parameters.h"
45 #include "copy-relocs.h"
47 #include "target-reloc.h"
48 #include "target-select.h"
52 #include "attributes.h"
53 #include "arm-reloc-property.h"
60 template<bool big_endian>
61 class Output_data_plt_arm;
63 template<bool big_endian>
66 template<bool big_endian>
67 class Arm_input_section;
69 class Arm_exidx_cantunwind;
71 class Arm_exidx_merged_section;
73 class Arm_exidx_fixup;
75 template<bool big_endian>
76 class Arm_output_section;
78 class Arm_exidx_input_section;
80 template<bool big_endian>
83 template<bool big_endian>
84 class Arm_relocate_functions;
86 template<bool big_endian>
87 class Arm_output_data_got;
89 template<bool big_endian>
93 typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address;
95 // Maximum branch offsets for ARM, THUMB and THUMB2.
96 const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8);
97 const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8);
98 const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4);
99 const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4);
100 const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4);
101 const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4);
103 // Thread Control Block size.
104 const size_t ARM_TCB_SIZE = 8;
106 // The arm target class.
108 // This is a very simple port of gold for ARM-EABI. It is intended for
109 // supporting Android only for the time being.
112 // - Implement all static relocation types documented in arm-reloc.def.
113 // - Make PLTs more flexible for different architecture features like
115 // There are probably a lot more.
117 // Ideally we would like to avoid using global variables but this is used
118 // very in many places and sometimes in loops. If we use a function
119 // returning a static instance of Arm_reloc_property_table, it will very
120 // slow in an threaded environment since the static instance needs to be
121 // locked. The pointer is below initialized in the
122 // Target::do_select_as_default_target() hook so that we do not spend time
123 // building the table if we are not linking ARM objects.
125 // An alternative is to to process the information in arm-reloc.def in
126 // compilation time and generate a representation of it in PODs only. That
127 // way we can avoid initialization when the linker starts.
129 Arm_reloc_property_table *arm_reloc_property_table = NULL;
131 // Instruction template class. This class is similar to the insn_sequence
132 // struct in bfd/elf32-arm.c.
137 // Types of instruction templates.
141 // THUMB16_SPECIAL_TYPE is used by sub-classes of Stub for instruction
142 // templates with class-specific semantics. Currently this is used
143 // only by the Cortex_a8_stub class for handling condition codes in
144 // conditional branches.
145 THUMB16_SPECIAL_TYPE,
151 // Factory methods to create instruction templates in different formats.
153 static const Insn_template
154 thumb16_insn(uint32_t data)
155 { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); }
157 // A Thumb conditional branch, in which the proper condition is inserted
158 // when we build the stub.
159 static const Insn_template
160 thumb16_bcond_insn(uint32_t data)
161 { return Insn_template(data, THUMB16_SPECIAL_TYPE, elfcpp::R_ARM_NONE, 1); }
163 static const Insn_template
164 thumb32_insn(uint32_t data)
165 { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); }
167 static const Insn_template
168 thumb32_b_insn(uint32_t data, int reloc_addend)
170 return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24,
174 static const Insn_template
175 arm_insn(uint32_t data)
176 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); }
178 static const Insn_template
179 arm_rel_insn(unsigned data, int reloc_addend)
180 { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); }
182 static const Insn_template
183 data_word(unsigned data, unsigned int r_type, int reloc_addend)
184 { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); }
186 // Accessors. This class is used for read-only objects so no modifiers
191 { return this->data_; }
193 // Return the instruction sequence type of this.
196 { return this->type_; }
198 // Return the ARM relocation type of this.
201 { return this->r_type_; }
205 { return this->reloc_addend_; }
207 // Return size of instruction template in bytes.
211 // Return byte-alignment of instruction template.
216 // We make the constructor private to ensure that only the factory
219 Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend)
220 : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend)
223 // Instruction specific data. This is used to store information like
224 // some of the instruction bits.
226 // Instruction template type.
228 // Relocation type if there is a relocation or R_ARM_NONE otherwise.
229 unsigned int r_type_;
230 // Relocation addend.
231 int32_t reloc_addend_;
234 // Macro for generating code to stub types. One entry per long/short
238 DEF_STUB(long_branch_any_any) \
239 DEF_STUB(long_branch_v4t_arm_thumb) \
240 DEF_STUB(long_branch_thumb_only) \
241 DEF_STUB(long_branch_v4t_thumb_thumb) \
242 DEF_STUB(long_branch_v4t_thumb_arm) \
243 DEF_STUB(short_branch_v4t_thumb_arm) \
244 DEF_STUB(long_branch_any_arm_pic) \
245 DEF_STUB(long_branch_any_thumb_pic) \
246 DEF_STUB(long_branch_v4t_thumb_thumb_pic) \
247 DEF_STUB(long_branch_v4t_arm_thumb_pic) \
248 DEF_STUB(long_branch_v4t_thumb_arm_pic) \
249 DEF_STUB(long_branch_thumb_only_pic) \
250 DEF_STUB(a8_veneer_b_cond) \
251 DEF_STUB(a8_veneer_b) \
252 DEF_STUB(a8_veneer_bl) \
253 DEF_STUB(a8_veneer_blx) \
254 DEF_STUB(v4_veneer_bx)
258 #define DEF_STUB(x) arm_stub_##x,
264 // First reloc stub type.
265 arm_stub_reloc_first = arm_stub_long_branch_any_any,
266 // Last reloc stub type.
267 arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic,
269 // First Cortex-A8 stub type.
270 arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond,
271 // Last Cortex-A8 stub type.
272 arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx,
275 arm_stub_type_last = arm_stub_v4_veneer_bx
279 // Stub template class. Templates are meant to be read-only objects.
280 // A stub template for a stub type contains all read-only attributes
281 // common to all stubs of the same type.
286 Stub_template(Stub_type, const Insn_template*, size_t);
294 { return this->type_; }
296 // Return an array of instruction templates.
299 { return this->insns_; }
301 // Return size of template in number of instructions.
304 { return this->insn_count_; }
306 // Return size of template in bytes.
309 { return this->size_; }
311 // Return alignment of the stub template.
314 { return this->alignment_; }
316 // Return whether entry point is in thumb mode.
318 entry_in_thumb_mode() const
319 { return this->entry_in_thumb_mode_; }
321 // Return number of relocations in this template.
324 { return this->relocs_.size(); }
326 // Return index of the I-th instruction with relocation.
328 reloc_insn_index(size_t i) const
330 gold_assert(i < this->relocs_.size());
331 return this->relocs_[i].first;
334 // Return the offset of the I-th instruction with relocation from the
335 // beginning of the stub.
337 reloc_offset(size_t i) const
339 gold_assert(i < this->relocs_.size());
340 return this->relocs_[i].second;
344 // This contains information about an instruction template with a relocation
345 // and its offset from start of stub.
346 typedef std::pair<size_t, section_size_type> Reloc;
348 // A Stub_template may not be copied. We want to share templates as much
350 Stub_template(const Stub_template&);
351 Stub_template& operator=(const Stub_template&);
355 // Points to an array of Insn_templates.
356 const Insn_template* insns_;
357 // Number of Insn_templates in insns_[].
359 // Size of templated instructions in bytes.
361 // Alignment of templated instructions.
363 // Flag to indicate if entry is in thumb mode.
364 bool entry_in_thumb_mode_;
365 // A table of reloc instruction indices and offsets. We can find these by
366 // looking at the instruction templates but we pre-compute and then stash
367 // them here for speed.
368 std::vector<Reloc> relocs_;
372 // A class for code stubs. This is a base class for different type of
373 // stubs used in the ARM target.
379 static const section_offset_type invalid_offset =
380 static_cast<section_offset_type>(-1);
383 Stub(const Stub_template* stub_template)
384 : stub_template_(stub_template), offset_(invalid_offset)
391 // Return the stub template.
393 stub_template() const
394 { return this->stub_template_; }
396 // Return offset of code stub from beginning of its containing stub table.
400 gold_assert(this->offset_ != invalid_offset);
401 return this->offset_;
404 // Set offset of code stub from beginning of its containing stub table.
406 set_offset(section_offset_type offset)
407 { this->offset_ = offset; }
409 // Return the relocation target address of the i-th relocation in the
410 // stub. This must be defined in a child class.
412 reloc_target(size_t i)
413 { return this->do_reloc_target(i); }
415 // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written.
417 write(unsigned char* view, section_size_type view_size, bool big_endian)
418 { this->do_write(view, view_size, big_endian); }
420 // Return the instruction for THUMB16_SPECIAL_TYPE instruction template
421 // for the i-th instruction.
423 thumb16_special(size_t i)
424 { return this->do_thumb16_special(i); }
427 // This must be defined in the child class.
429 do_reloc_target(size_t) = 0;
431 // This may be overridden in the child class.
433 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
436 this->do_fixed_endian_write<true>(view, view_size);
438 this->do_fixed_endian_write<false>(view, view_size);
441 // This must be overridden if a child class uses the THUMB16_SPECIAL_TYPE
442 // instruction template.
444 do_thumb16_special(size_t)
445 { gold_unreachable(); }
448 // A template to implement do_write.
449 template<bool big_endian>
451 do_fixed_endian_write(unsigned char*, section_size_type);
454 const Stub_template* stub_template_;
455 // Offset within the section of containing this stub.
456 section_offset_type offset_;
459 // Reloc stub class. These are stubs we use to fix up relocation because
460 // of limited branch ranges.
462 class Reloc_stub : public Stub
465 static const unsigned int invalid_index = static_cast<unsigned int>(-1);
466 // We assume we never jump to this address.
467 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
469 // Return destination address.
471 destination_address() const
473 gold_assert(this->destination_address_ != this->invalid_address);
474 return this->destination_address_;
477 // Set destination address.
479 set_destination_address(Arm_address address)
481 gold_assert(address != this->invalid_address);
482 this->destination_address_ = address;
485 // Reset destination address.
487 reset_destination_address()
488 { this->destination_address_ = this->invalid_address; }
490 // Determine stub type for a branch of a relocation of R_TYPE going
491 // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set,
492 // the branch target is a thumb instruction. TARGET is used for look
493 // up ARM-specific linker settings.
495 stub_type_for_reloc(unsigned int r_type, Arm_address branch_address,
496 Arm_address branch_target, bool target_is_thumb);
498 // Reloc_stub key. A key is logically a triplet of a stub type, a symbol
499 // and an addend. Since we treat global and local symbol differently, we
500 // use a Symbol object for a global symbol and a object-index pair for
505 // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and
506 // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL
507 // and R_SYM must not be invalid_index.
508 Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj,
509 unsigned int r_sym, int32_t addend)
510 : stub_type_(stub_type), addend_(addend)
514 this->r_sym_ = Reloc_stub::invalid_index;
515 this->u_.symbol = symbol;
519 gold_assert(relobj != NULL && r_sym != invalid_index);
520 this->r_sym_ = r_sym;
521 this->u_.relobj = relobj;
528 // Accessors: Keys are meant to be read-only object so no modifiers are
534 { return this->stub_type_; }
536 // Return the local symbol index or invalid_index.
539 { return this->r_sym_; }
541 // Return the symbol if there is one.
544 { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; }
546 // Return the relobj if there is one.
549 { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; }
551 // Whether this equals to another key k.
553 eq(const Key& k) const
555 return ((this->stub_type_ == k.stub_type_)
556 && (this->r_sym_ == k.r_sym_)
557 && ((this->r_sym_ != Reloc_stub::invalid_index)
558 ? (this->u_.relobj == k.u_.relobj)
559 : (this->u_.symbol == k.u_.symbol))
560 && (this->addend_ == k.addend_));
563 // Return a hash value.
567 return (this->stub_type_
569 ^ gold::string_hash<char>(
570 (this->r_sym_ != Reloc_stub::invalid_index)
571 ? this->u_.relobj->name().c_str()
572 : this->u_.symbol->name())
576 // Functors for STL associative containers.
580 operator()(const Key& k) const
581 { return k.hash_value(); }
587 operator()(const Key& k1, const Key& k2) const
588 { return k1.eq(k2); }
591 // Name of key. This is mainly for debugging.
597 Stub_type stub_type_;
598 // If this is a local symbol, this is the index in the defining object.
599 // Otherwise, it is invalid_index for a global symbol.
601 // If r_sym_ is invalid index. This points to a global symbol.
602 // Otherwise, this points a relobj. We used the unsized and target
603 // independent Symbol and Relobj classes instead of Sized_symbol<32> and
604 // Arm_relobj. This is done to avoid making the stub class a template
605 // as most of the stub machinery is endianness-neutral. However, it
606 // may require a bit of casting done by users of this class.
609 const Symbol* symbol;
610 const Relobj* relobj;
612 // Addend associated with a reloc.
617 // Reloc_stubs are created via a stub factory. So these are protected.
618 Reloc_stub(const Stub_template* stub_template)
619 : Stub(stub_template), destination_address_(invalid_address)
625 friend class Stub_factory;
627 // Return the relocation target address of the i-th relocation in the
630 do_reloc_target(size_t i)
632 // All reloc stub have only one relocation.
634 return this->destination_address_;
638 // Address of destination.
639 Arm_address destination_address_;
642 // Cortex-A8 stub class. We need a Cortex-A8 stub to redirect any 32-bit
643 // THUMB branch that meets the following conditions:
645 // 1. The branch straddles across a page boundary. i.e. lower 12-bit of
646 // branch address is 0xffe.
647 // 2. The branch target address is in the same page as the first word of the
649 // 3. The branch follows a 32-bit instruction which is not a branch.
651 // To do the fix up, we need to store the address of the branch instruction
652 // and its target at least. We also need to store the original branch
653 // instruction bits for the condition code in a conditional branch. The
654 // condition code is used in a special instruction template. We also want
655 // to identify input sections needing Cortex-A8 workaround quickly. We store
656 // extra information about object and section index of the code section
657 // containing a branch being fixed up. The information is used to mark
658 // the code section when we finalize the Cortex-A8 stubs.
661 class Cortex_a8_stub : public Stub
667 // Return the object of the code section containing the branch being fixed
671 { return this->relobj_; }
673 // Return the section index of the code section containing the branch being
677 { return this->shndx_; }
679 // Return the source address of stub. This is the address of the original
680 // branch instruction. LSB is 1 always set to indicate that it is a THUMB
683 source_address() const
684 { return this->source_address_; }
686 // Return the destination address of the stub. This is the branch taken
687 // address of the original branch instruction. LSB is 1 if it is a THUMB
688 // instruction address.
690 destination_address() const
691 { return this->destination_address_; }
693 // Return the instruction being fixed up.
695 original_insn() const
696 { return this->original_insn_; }
699 // Cortex_a8_stubs are created via a stub factory. So these are protected.
700 Cortex_a8_stub(const Stub_template* stub_template, Relobj* relobj,
701 unsigned int shndx, Arm_address source_address,
702 Arm_address destination_address, uint32_t original_insn)
703 : Stub(stub_template), relobj_(relobj), shndx_(shndx),
704 source_address_(source_address | 1U),
705 destination_address_(destination_address),
706 original_insn_(original_insn)
709 friend class Stub_factory;
711 // Return the relocation target address of the i-th relocation in the
714 do_reloc_target(size_t i)
716 if (this->stub_template()->type() == arm_stub_a8_veneer_b_cond)
718 // The conditional branch veneer has two relocations.
720 return i == 0 ? this->source_address_ + 4 : this->destination_address_;
724 // All other Cortex-A8 stubs have only one relocation.
726 return this->destination_address_;
730 // Return an instruction for the THUMB16_SPECIAL_TYPE instruction template.
732 do_thumb16_special(size_t);
735 // Object of the code section containing the branch being fixed up.
737 // Section index of the code section containing the branch begin fixed up.
739 // Source address of original branch.
740 Arm_address source_address_;
741 // Destination address of the original branch.
742 Arm_address destination_address_;
743 // Original branch instruction. This is needed for copying the condition
744 // code from a condition branch to its stub.
745 uint32_t original_insn_;
748 // ARMv4 BX Rx branch relocation stub class.
749 class Arm_v4bx_stub : public Stub
755 // Return the associated register.
758 { return this->reg_; }
761 // Arm V4BX stubs are created via a stub factory. So these are protected.
762 Arm_v4bx_stub(const Stub_template* stub_template, const uint32_t reg)
763 : Stub(stub_template), reg_(reg)
766 friend class Stub_factory;
768 // Return the relocation target address of the i-th relocation in the
771 do_reloc_target(size_t)
772 { gold_unreachable(); }
774 // This may be overridden in the child class.
776 do_write(unsigned char* view, section_size_type view_size, bool big_endian)
779 this->do_fixed_endian_v4bx_write<true>(view, view_size);
781 this->do_fixed_endian_v4bx_write<false>(view, view_size);
785 // A template to implement do_write.
786 template<bool big_endian>
788 do_fixed_endian_v4bx_write(unsigned char* view, section_size_type)
790 const Insn_template* insns = this->stub_template()->insns();
791 elfcpp::Swap<32, big_endian>::writeval(view,
793 + (this->reg_ << 16)));
794 view += insns[0].size();
795 elfcpp::Swap<32, big_endian>::writeval(view,
796 (insns[1].data() + this->reg_));
797 view += insns[1].size();
798 elfcpp::Swap<32, big_endian>::writeval(view,
799 (insns[2].data() + this->reg_));
802 // A register index (r0-r14), which is associated with the stub.
806 // Stub factory class.
811 // Return the unique instance of this class.
812 static const Stub_factory&
815 static Stub_factory singleton;
819 // Make a relocation stub.
821 make_reloc_stub(Stub_type stub_type) const
823 gold_assert(stub_type >= arm_stub_reloc_first
824 && stub_type <= arm_stub_reloc_last);
825 return new Reloc_stub(this->stub_templates_[stub_type]);
828 // Make a Cortex-A8 stub.
830 make_cortex_a8_stub(Stub_type stub_type, Relobj* relobj, unsigned int shndx,
831 Arm_address source, Arm_address destination,
832 uint32_t original_insn) const
834 gold_assert(stub_type >= arm_stub_cortex_a8_first
835 && stub_type <= arm_stub_cortex_a8_last);
836 return new Cortex_a8_stub(this->stub_templates_[stub_type], relobj, shndx,
837 source, destination, original_insn);
840 // Make an ARM V4BX relocation stub.
841 // This method creates a stub from the arm_stub_v4_veneer_bx template only.
843 make_arm_v4bx_stub(uint32_t reg) const
845 gold_assert(reg < 0xf);
846 return new Arm_v4bx_stub(this->stub_templates_[arm_stub_v4_veneer_bx],
851 // Constructor and destructor are protected since we only return a single
852 // instance created in Stub_factory::get_instance().
856 // A Stub_factory may not be copied since it is a singleton.
857 Stub_factory(const Stub_factory&);
858 Stub_factory& operator=(Stub_factory&);
860 // Stub templates. These are initialized in the constructor.
861 const Stub_template* stub_templates_[arm_stub_type_last+1];
864 // A class to hold stubs for the ARM target.
866 template<bool big_endian>
867 class Stub_table : public Output_data
870 Stub_table(Arm_input_section<big_endian>* owner)
871 : Output_data(), owner_(owner), reloc_stubs_(), reloc_stubs_size_(0),
872 reloc_stubs_addralign_(1), cortex_a8_stubs_(), arm_v4bx_stubs_(0xf),
873 prev_data_size_(0), prev_addralign_(1)
879 // Owner of this stub table.
880 Arm_input_section<big_endian>*
882 { return this->owner_; }
884 // Whether this stub table is empty.
888 return (this->reloc_stubs_.empty()
889 && this->cortex_a8_stubs_.empty()
890 && this->arm_v4bx_stubs_.empty());
893 // Return the current data size.
895 current_data_size() const
896 { return this->current_data_size_for_child(); }
898 // Add a STUB with using KEY. Caller is reponsible for avoid adding
899 // if already a STUB with the same key has been added.
901 add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key)
903 const Stub_template* stub_template = stub->stub_template();
904 gold_assert(stub_template->type() == key.stub_type());
905 this->reloc_stubs_[key] = stub;
907 // Assign stub offset early. We can do this because we never remove
908 // reloc stubs and they are in the beginning of the stub table.
909 uint64_t align = stub_template->alignment();
910 this->reloc_stubs_size_ = align_address(this->reloc_stubs_size_, align);
911 stub->set_offset(this->reloc_stubs_size_);
912 this->reloc_stubs_size_ += stub_template->size();
913 this->reloc_stubs_addralign_ =
914 std::max(this->reloc_stubs_addralign_, align);
917 // Add a Cortex-A8 STUB that fixes up a THUMB branch at ADDRESS.
918 // Caller is reponsible for avoid adding if already a STUB with the same
919 // address has been added.
921 add_cortex_a8_stub(Arm_address address, Cortex_a8_stub* stub)
923 std::pair<Arm_address, Cortex_a8_stub*> value(address, stub);
924 this->cortex_a8_stubs_.insert(value);
927 // Add an ARM V4BX relocation stub. A register index will be retrieved
930 add_arm_v4bx_stub(Arm_v4bx_stub* stub)
932 gold_assert(stub != NULL && this->arm_v4bx_stubs_[stub->reg()] == NULL);
933 this->arm_v4bx_stubs_[stub->reg()] = stub;
936 // Remove all Cortex-A8 stubs.
938 remove_all_cortex_a8_stubs();
940 // Look up a relocation stub using KEY. Return NULL if there is none.
942 find_reloc_stub(const Reloc_stub::Key& key) const
944 typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key);
945 return (p != this->reloc_stubs_.end()) ? p->second : NULL;
948 // Look up an arm v4bx relocation stub using the register index.
949 // Return NULL if there is none.
951 find_arm_v4bx_stub(const uint32_t reg) const
953 gold_assert(reg < 0xf);
954 return this->arm_v4bx_stubs_[reg];
957 // Relocate stubs in this stub table.
959 relocate_stubs(const Relocate_info<32, big_endian>*,
960 Target_arm<big_endian>*, Output_section*,
961 unsigned char*, Arm_address, section_size_type);
963 // Update data size and alignment at the end of a relaxation pass. Return
964 // true if either data size or alignment is different from that of the
965 // previous relaxation pass.
967 update_data_size_and_addralign();
969 // Finalize stubs. Set the offsets of all stubs and mark input sections
970 // needing the Cortex-A8 workaround.
974 // Apply Cortex-A8 workaround to an address range.
976 apply_cortex_a8_workaround_to_address_range(Target_arm<big_endian>*,
977 unsigned char*, Arm_address,
981 // Write out section contents.
983 do_write(Output_file*);
985 // Return the required alignment.
988 { return this->prev_addralign_; }
990 // Reset address and file offset.
992 do_reset_address_and_file_offset()
993 { this->set_current_data_size_for_child(this->prev_data_size_); }
995 // Set final data size.
997 set_final_data_size()
998 { this->set_data_size(this->current_data_size()); }
1001 // Relocate one stub.
1003 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
1004 Target_arm<big_endian>*, Output_section*,
1005 unsigned char*, Arm_address, section_size_type);
1007 // Unordered map of relocation stubs.
1009 Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash,
1010 Reloc_stub::Key::equal_to>
1013 // List of Cortex-A8 stubs ordered by addresses of branches being
1014 // fixed up in output.
1015 typedef std::map<Arm_address, Cortex_a8_stub*> Cortex_a8_stub_list;
1016 // List of Arm V4BX relocation stubs ordered by associated registers.
1017 typedef std::vector<Arm_v4bx_stub*> Arm_v4bx_stub_list;
1019 // Owner of this stub table.
1020 Arm_input_section<big_endian>* owner_;
1021 // The relocation stubs.
1022 Reloc_stub_map reloc_stubs_;
1023 // Size of reloc stubs.
1024 off_t reloc_stubs_size_;
1025 // Maximum address alignment of reloc stubs.
1026 uint64_t reloc_stubs_addralign_;
1027 // The cortex_a8_stubs.
1028 Cortex_a8_stub_list cortex_a8_stubs_;
1029 // The Arm V4BX relocation stubs.
1030 Arm_v4bx_stub_list arm_v4bx_stubs_;
1031 // data size of this in the previous pass.
1032 off_t prev_data_size_;
1033 // address alignment of this in the previous pass.
1034 uint64_t prev_addralign_;
1037 // Arm_exidx_cantunwind class. This represents an EXIDX_CANTUNWIND entry
1038 // we add to the end of an EXIDX input section that goes into the output.
1040 class Arm_exidx_cantunwind : public Output_section_data
1043 Arm_exidx_cantunwind(Relobj* relobj, unsigned int shndx)
1044 : Output_section_data(8, 4, true), relobj_(relobj), shndx_(shndx)
1047 // Return the object containing the section pointed by this.
1050 { return this->relobj_; }
1052 // Return the section index of the section pointed by this.
1055 { return this->shndx_; }
1059 do_write(Output_file* of)
1061 if (parameters->target().is_big_endian())
1062 this->do_fixed_endian_write<true>(of);
1064 this->do_fixed_endian_write<false>(of);
1068 // Implement do_write for a given endianness.
1069 template<bool big_endian>
1071 do_fixed_endian_write(Output_file*);
1073 // The object containing the section pointed by this.
1075 // The section index of the section pointed by this.
1076 unsigned int shndx_;
1079 // During EXIDX coverage fix-up, we compact an EXIDX section. The
1080 // Offset map is used to map input section offset within the EXIDX section
1081 // to the output offset from the start of this EXIDX section.
1083 typedef std::map<section_offset_type, section_offset_type>
1084 Arm_exidx_section_offset_map;
1086 // Arm_exidx_merged_section class. This represents an EXIDX input section
1087 // with some of its entries merged.
1089 class Arm_exidx_merged_section : public Output_relaxed_input_section
1092 // Constructor for Arm_exidx_merged_section.
1093 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
1094 // SECTION_OFFSET_MAP points to a section offset map describing how
1095 // parts of the input section are mapped to output. DELETED_BYTES is
1096 // the number of bytes deleted from the EXIDX input section.
1097 Arm_exidx_merged_section(
1098 const Arm_exidx_input_section& exidx_input_section,
1099 const Arm_exidx_section_offset_map& section_offset_map,
1100 uint32_t deleted_bytes);
1102 // Return the original EXIDX input section.
1103 const Arm_exidx_input_section&
1104 exidx_input_section() const
1105 { return this->exidx_input_section_; }
1107 // Return the section offset map.
1108 const Arm_exidx_section_offset_map&
1109 section_offset_map() const
1110 { return this->section_offset_map_; }
1113 // Write merged section into file OF.
1115 do_write(Output_file* of);
1118 do_output_offset(const Relobj*, unsigned int, section_offset_type,
1119 section_offset_type*) const;
1122 // Original EXIDX input section.
1123 const Arm_exidx_input_section& exidx_input_section_;
1124 // Section offset map.
1125 const Arm_exidx_section_offset_map& section_offset_map_;
1128 // A class to wrap an ordinary input section containing executable code.
1130 template<bool big_endian>
1131 class Arm_input_section : public Output_relaxed_input_section
1134 Arm_input_section(Relobj* relobj, unsigned int shndx)
1135 : Output_relaxed_input_section(relobj, shndx, 1),
1136 original_addralign_(1), original_size_(0), stub_table_(NULL)
1139 ~Arm_input_section()
1146 // Whether this is a stub table owner.
1148 is_stub_table_owner() const
1149 { return this->stub_table_ != NULL && this->stub_table_->owner() == this; }
1151 // Return the stub table.
1152 Stub_table<big_endian>*
1154 { return this->stub_table_; }
1156 // Set the stub_table.
1158 set_stub_table(Stub_table<big_endian>* stub_table)
1159 { this->stub_table_ = stub_table; }
1161 // Downcast a base pointer to an Arm_input_section pointer. This is
1162 // not type-safe but we only use Arm_input_section not the base class.
1163 static Arm_input_section<big_endian>*
1164 as_arm_input_section(Output_relaxed_input_section* poris)
1165 { return static_cast<Arm_input_section<big_endian>*>(poris); }
1168 // Write data to output file.
1170 do_write(Output_file*);
1172 // Return required alignment of this.
1174 do_addralign() const
1176 if (this->is_stub_table_owner())
1177 return std::max(this->stub_table_->addralign(),
1178 this->original_addralign_);
1180 return this->original_addralign_;
1183 // Finalize data size.
1185 set_final_data_size();
1187 // Reset address and file offset.
1189 do_reset_address_and_file_offset();
1193 do_output_offset(const Relobj* object, unsigned int shndx,
1194 section_offset_type offset,
1195 section_offset_type* poutput) const
1197 if ((object == this->relobj())
1198 && (shndx == this->shndx())
1200 && (convert_types<uint64_t, section_offset_type>(offset)
1201 <= this->original_size_))
1211 // Copying is not allowed.
1212 Arm_input_section(const Arm_input_section&);
1213 Arm_input_section& operator=(const Arm_input_section&);
1215 // Address alignment of the original input section.
1216 uint64_t original_addralign_;
1217 // Section size of the original input section.
1218 uint64_t original_size_;
1220 Stub_table<big_endian>* stub_table_;
1223 // Arm_exidx_fixup class. This is used to define a number of methods
1224 // and keep states for fixing up EXIDX coverage.
1226 class Arm_exidx_fixup
1229 Arm_exidx_fixup(Output_section* exidx_output_section)
1230 : exidx_output_section_(exidx_output_section), last_unwind_type_(UT_NONE),
1231 last_inlined_entry_(0), last_input_section_(NULL),
1232 section_offset_map_(NULL), first_output_text_section_(NULL)
1236 { delete this->section_offset_map_; }
1238 // Process an EXIDX section for entry merging. Return number of bytes to
1239 // be deleted in output. If parts of the input EXIDX section are merged
1240 // a heap allocated Arm_exidx_section_offset_map is store in the located
1241 // PSECTION_OFFSET_MAP. The caller owns the map and is reponsible for
1243 template<bool big_endian>
1245 process_exidx_section(const Arm_exidx_input_section* exidx_input_section,
1246 Arm_exidx_section_offset_map** psection_offset_map);
1248 // Append an EXIDX_CANTUNWIND entry pointing at the end of the last
1249 // input section, if there is not one already.
1251 add_exidx_cantunwind_as_needed();
1253 // Return the output section for the text section which is linked to the
1254 // first exidx input in output.
1256 first_output_text_section() const
1257 { return this->first_output_text_section_; }
1260 // Copying is not allowed.
1261 Arm_exidx_fixup(const Arm_exidx_fixup&);
1262 Arm_exidx_fixup& operator=(const Arm_exidx_fixup&);
1264 // Type of EXIDX unwind entry.
1269 // EXIDX_CANTUNWIND.
1270 UT_EXIDX_CANTUNWIND,
1277 // Process an EXIDX entry. We only care about the second word of the
1278 // entry. Return true if the entry can be deleted.
1280 process_exidx_entry(uint32_t second_word);
1282 // Update the current section offset map during EXIDX section fix-up.
1283 // If there is no map, create one. INPUT_OFFSET is the offset of a
1284 // reference point, DELETED_BYTES is the number of deleted by in the
1285 // section so far. If DELETE_ENTRY is true, the reference point and
1286 // all offsets after the previous reference point are discarded.
1288 update_offset_map(section_offset_type input_offset,
1289 section_size_type deleted_bytes, bool delete_entry);
1291 // EXIDX output section.
1292 Output_section* exidx_output_section_;
1293 // Unwind type of the last EXIDX entry processed.
1294 Unwind_type last_unwind_type_;
1295 // Last seen inlined EXIDX entry.
1296 uint32_t last_inlined_entry_;
1297 // Last processed EXIDX input section.
1298 const Arm_exidx_input_section* last_input_section_;
1299 // Section offset map created in process_exidx_section.
1300 Arm_exidx_section_offset_map* section_offset_map_;
1301 // Output section for the text section which is linked to the first exidx
1303 Output_section* first_output_text_section_;
1306 // Arm output section class. This is defined mainly to add a number of
1307 // stub generation methods.
1309 template<bool big_endian>
1310 class Arm_output_section : public Output_section
1313 typedef std::vector<std::pair<Relobj*, unsigned int> > Text_section_list;
1315 Arm_output_section(const char* name, elfcpp::Elf_Word type,
1316 elfcpp::Elf_Xword flags)
1317 : Output_section(name, type, flags)
1320 ~Arm_output_section()
1323 // Group input sections for stub generation.
1325 group_sections(section_size_type, bool, Target_arm<big_endian>*);
1327 // Downcast a base pointer to an Arm_output_section pointer. This is
1328 // not type-safe but we only use Arm_output_section not the base class.
1329 static Arm_output_section<big_endian>*
1330 as_arm_output_section(Output_section* os)
1331 { return static_cast<Arm_output_section<big_endian>*>(os); }
1333 // Append all input text sections in this into LIST.
1335 append_text_sections_to_list(Text_section_list* list);
1337 // Fix EXIDX coverage of this EXIDX output section. SORTED_TEXT_SECTION
1338 // is a list of text input sections sorted in ascending order of their
1339 // output addresses.
1341 fix_exidx_coverage(Layout* layout,
1342 const Text_section_list& sorted_text_section,
1343 Symbol_table* symtab);
1347 typedef Output_section::Input_section Input_section;
1348 typedef Output_section::Input_section_list Input_section_list;
1350 // Create a stub group.
1351 void create_stub_group(Input_section_list::const_iterator,
1352 Input_section_list::const_iterator,
1353 Input_section_list::const_iterator,
1354 Target_arm<big_endian>*,
1355 std::vector<Output_relaxed_input_section*>*);
1358 // Arm_exidx_input_section class. This represents an EXIDX input section.
1360 class Arm_exidx_input_section
1363 static const section_offset_type invalid_offset =
1364 static_cast<section_offset_type>(-1);
1366 Arm_exidx_input_section(Relobj* relobj, unsigned int shndx,
1367 unsigned int link, uint32_t size, uint32_t addralign)
1368 : relobj_(relobj), shndx_(shndx), link_(link), size_(size),
1369 addralign_(addralign)
1372 ~Arm_exidx_input_section()
1375 // Accessors: This is a read-only class.
1377 // Return the object containing this EXIDX input section.
1380 { return this->relobj_; }
1382 // Return the section index of this EXIDX input section.
1385 { return this->shndx_; }
1387 // Return the section index of linked text section in the same object.
1390 { return this->link_; }
1392 // Return size of the EXIDX input section.
1395 { return this->size_; }
1397 // Reutnr address alignment of EXIDX input section.
1400 { return this->addralign_; }
1403 // Object containing this.
1405 // Section index of this.
1406 unsigned int shndx_;
1407 // text section linked to this in the same object.
1409 // Size of this. For ARM 32-bit is sufficient.
1411 // Address alignment of this. For ARM 32-bit is sufficient.
1412 uint32_t addralign_;
1415 // Arm_relobj class.
1417 template<bool big_endian>
1418 class Arm_relobj : public Sized_relobj<32, big_endian>
1421 static const Arm_address invalid_address = static_cast<Arm_address>(-1);
1423 Arm_relobj(const std::string& name, Input_file* input_file, off_t offset,
1424 const typename elfcpp::Ehdr<32, big_endian>& ehdr)
1425 : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr),
1426 stub_tables_(), local_symbol_is_thumb_function_(),
1427 attributes_section_data_(NULL), mapping_symbols_info_(),
1428 section_has_cortex_a8_workaround_(NULL), exidx_section_map_(),
1429 output_local_symbol_count_needs_update_(false),
1430 merge_flags_and_attributes_(true)
1434 { delete this->attributes_section_data_; }
1436 // Return the stub table of the SHNDX-th section if there is one.
1437 Stub_table<big_endian>*
1438 stub_table(unsigned int shndx) const
1440 gold_assert(shndx < this->stub_tables_.size());
1441 return this->stub_tables_[shndx];
1444 // Set STUB_TABLE to be the stub_table of the SHNDX-th section.
1446 set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table)
1448 gold_assert(shndx < this->stub_tables_.size());
1449 this->stub_tables_[shndx] = stub_table;
1452 // Whether a local symbol is a THUMB function. R_SYM is the symbol table
1453 // index. This is only valid after do_count_local_symbol is called.
1455 local_symbol_is_thumb_function(unsigned int r_sym) const
1457 gold_assert(r_sym < this->local_symbol_is_thumb_function_.size());
1458 return this->local_symbol_is_thumb_function_[r_sym];
1461 // Scan all relocation sections for stub generation.
1463 scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*,
1466 // Convert regular input section with index SHNDX to a relaxed section.
1468 convert_input_section_to_relaxed_section(unsigned shndx)
1470 // The stubs have relocations and we need to process them after writing
1471 // out the stubs. So relocation now must follow section write.
1472 this->set_section_offset(shndx, -1ULL);
1473 this->set_relocs_must_follow_section_writes();
1476 // Downcast a base pointer to an Arm_relobj pointer. This is
1477 // not type-safe but we only use Arm_relobj not the base class.
1478 static Arm_relobj<big_endian>*
1479 as_arm_relobj(Relobj* relobj)
1480 { return static_cast<Arm_relobj<big_endian>*>(relobj); }
1482 // Processor-specific flags in ELF file header. This is valid only after
1485 processor_specific_flags() const
1486 { return this->processor_specific_flags_; }
1488 // Attribute section data This is the contents of the .ARM.attribute section
1490 const Attributes_section_data*
1491 attributes_section_data() const
1492 { return this->attributes_section_data_; }
1494 // Mapping symbol location.
1495 typedef std::pair<unsigned int, Arm_address> Mapping_symbol_position;
1497 // Functor for STL container.
1498 struct Mapping_symbol_position_less
1501 operator()(const Mapping_symbol_position& p1,
1502 const Mapping_symbol_position& p2) const
1504 return (p1.first < p2.first
1505 || (p1.first == p2.first && p1.second < p2.second));
1509 // We only care about the first character of a mapping symbol, so
1510 // we only store that instead of the whole symbol name.
1511 typedef std::map<Mapping_symbol_position, char,
1512 Mapping_symbol_position_less> Mapping_symbols_info;
1514 // Whether a section contains any Cortex-A8 workaround.
1516 section_has_cortex_a8_workaround(unsigned int shndx) const
1518 return (this->section_has_cortex_a8_workaround_ != NULL
1519 && (*this->section_has_cortex_a8_workaround_)[shndx]);
1522 // Mark a section that has Cortex-A8 workaround.
1524 mark_section_for_cortex_a8_workaround(unsigned int shndx)
1526 if (this->section_has_cortex_a8_workaround_ == NULL)
1527 this->section_has_cortex_a8_workaround_ =
1528 new std::vector<bool>(this->shnum(), false);
1529 (*this->section_has_cortex_a8_workaround_)[shndx] = true;
1532 // Return the EXIDX section of an text section with index SHNDX or NULL
1533 // if the text section has no associated EXIDX section.
1534 const Arm_exidx_input_section*
1535 exidx_input_section_by_link(unsigned int shndx) const
1537 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1538 return ((p != this->exidx_section_map_.end()
1539 && p->second->link() == shndx)
1544 // Return the EXIDX section with index SHNDX or NULL if there is none.
1545 const Arm_exidx_input_section*
1546 exidx_input_section_by_shndx(unsigned shndx) const
1548 Exidx_section_map::const_iterator p = this->exidx_section_map_.find(shndx);
1549 return ((p != this->exidx_section_map_.end()
1550 && p->second->shndx() == shndx)
1555 // Whether output local symbol count needs updating.
1557 output_local_symbol_count_needs_update() const
1558 { return this->output_local_symbol_count_needs_update_; }
1560 // Set output_local_symbol_count_needs_update flag to be true.
1562 set_output_local_symbol_count_needs_update()
1563 { this->output_local_symbol_count_needs_update_ = true; }
1565 // Update output local symbol count at the end of relaxation.
1567 update_output_local_symbol_count();
1569 // Whether we want to merge processor-specific flags and attributes.
1571 merge_flags_and_attributes() const
1572 { return this->merge_flags_and_attributes_; }
1575 // Post constructor setup.
1579 // Call parent's setup method.
1580 Sized_relobj<32, big_endian>::do_setup();
1582 // Initialize look-up tables.
1583 Stub_table_list empty_stub_table_list(this->shnum(), NULL);
1584 this->stub_tables_.swap(empty_stub_table_list);
1587 // Count the local symbols.
1589 do_count_local_symbols(Stringpool_template<char>*,
1590 Stringpool_template<char>*);
1593 do_relocate_sections(const Symbol_table* symtab, const Layout* layout,
1594 const unsigned char* pshdrs,
1595 typename Sized_relobj<32, big_endian>::Views* pivews);
1597 // Read the symbol information.
1599 do_read_symbols(Read_symbols_data* sd);
1601 // Process relocs for garbage collection.
1603 do_gc_process_relocs(Symbol_table*, Layout*, Read_relocs_data*);
1607 // Whether a section needs to be scanned for relocation stubs.
1609 section_needs_reloc_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1610 const Relobj::Output_sections&,
1611 const Symbol_table *, const unsigned char*);
1613 // Whether a section is a scannable text section.
1615 section_is_scannable(const elfcpp::Shdr<32, big_endian>&, unsigned int,
1616 const Output_section*, const Symbol_table *);
1618 // Whether a section needs to be scanned for the Cortex-A8 erratum.
1620 section_needs_cortex_a8_stub_scanning(const elfcpp::Shdr<32, big_endian>&,
1621 unsigned int, Output_section*,
1622 const Symbol_table *);
1624 // Scan a section for the Cortex-A8 erratum.
1626 scan_section_for_cortex_a8_erratum(const elfcpp::Shdr<32, big_endian>&,
1627 unsigned int, Output_section*,
1628 Target_arm<big_endian>*);
1630 // Find the linked text section of an EXIDX section by looking at the
1631 // first reloction of the EXIDX section. PSHDR points to the section
1632 // headers of a relocation section and PSYMS points to the local symbols.
1633 // PSHNDX points to a location storing the text section index if found.
1634 // Return whether we can find the linked section.
1636 find_linked_text_section(const unsigned char* pshdr,
1637 const unsigned char* psyms, unsigned int* pshndx);
1640 // Make a new Arm_exidx_input_section object for EXIDX section with
1641 // index SHNDX and section header SHDR. TEXT_SHNDX is the section
1642 // index of the linked text section.
1644 make_exidx_input_section(unsigned int shndx,
1645 const elfcpp::Shdr<32, big_endian>& shdr,
1646 unsigned int text_shndx);
1648 // Return the output address of either a plain input section or a
1649 // relaxed input section. SHNDX is the section index.
1651 simple_input_section_output_address(unsigned int, Output_section*);
1653 typedef std::vector<Stub_table<big_endian>*> Stub_table_list;
1654 typedef Unordered_map<unsigned int, const Arm_exidx_input_section*>
1657 // List of stub tables.
1658 Stub_table_list stub_tables_;
1659 // Bit vector to tell if a local symbol is a thumb function or not.
1660 // This is only valid after do_count_local_symbol is called.
1661 std::vector<bool> local_symbol_is_thumb_function_;
1662 // processor-specific flags in ELF file header.
1663 elfcpp::Elf_Word processor_specific_flags_;
1664 // Object attributes if there is an .ARM.attributes section or NULL.
1665 Attributes_section_data* attributes_section_data_;
1666 // Mapping symbols information.
1667 Mapping_symbols_info mapping_symbols_info_;
1668 // Bitmap to indicate sections with Cortex-A8 workaround or NULL.
1669 std::vector<bool>* section_has_cortex_a8_workaround_;
1670 // Map a text section to its associated .ARM.exidx section, if there is one.
1671 Exidx_section_map exidx_section_map_;
1672 // Whether output local symbol count needs updating.
1673 bool output_local_symbol_count_needs_update_;
1674 // Whether we merge processor flags and attributes of this object to
1676 bool merge_flags_and_attributes_;
1679 // Arm_dynobj class.
1681 template<bool big_endian>
1682 class Arm_dynobj : public Sized_dynobj<32, big_endian>
1685 Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset,
1686 const elfcpp::Ehdr<32, big_endian>& ehdr)
1687 : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr),
1688 processor_specific_flags_(0), attributes_section_data_(NULL)
1692 { delete this->attributes_section_data_; }
1694 // Downcast a base pointer to an Arm_relobj pointer. This is
1695 // not type-safe but we only use Arm_relobj not the base class.
1696 static Arm_dynobj<big_endian>*
1697 as_arm_dynobj(Dynobj* dynobj)
1698 { return static_cast<Arm_dynobj<big_endian>*>(dynobj); }
1700 // Processor-specific flags in ELF file header. This is valid only after
1703 processor_specific_flags() const
1704 { return this->processor_specific_flags_; }
1706 // Attributes section data.
1707 const Attributes_section_data*
1708 attributes_section_data() const
1709 { return this->attributes_section_data_; }
1712 // Read the symbol information.
1714 do_read_symbols(Read_symbols_data* sd);
1717 // processor-specific flags in ELF file header.
1718 elfcpp::Elf_Word processor_specific_flags_;
1719 // Object attributes if there is an .ARM.attributes section or NULL.
1720 Attributes_section_data* attributes_section_data_;
1723 // Functor to read reloc addends during stub generation.
1725 template<int sh_type, bool big_endian>
1726 struct Stub_addend_reader
1728 // Return the addend for a relocation of a particular type. Depending
1729 // on whether this is a REL or RELA relocation, read the addend from a
1730 // view or from a Reloc object.
1731 elfcpp::Elf_types<32>::Elf_Swxword
1733 unsigned int /* r_type */,
1734 const unsigned char* /* view */,
1735 const typename Reloc_types<sh_type,
1736 32, big_endian>::Reloc& /* reloc */) const;
1739 // Specialized Stub_addend_reader for SHT_REL type relocation sections.
1741 template<bool big_endian>
1742 struct Stub_addend_reader<elfcpp::SHT_REL, big_endian>
1744 elfcpp::Elf_types<32>::Elf_Swxword
1747 const unsigned char*,
1748 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const;
1751 // Specialized Stub_addend_reader for RELA type relocation sections.
1752 // We currently do not handle RELA type relocation sections but it is trivial
1753 // to implement the addend reader. This is provided for completeness and to
1754 // make it easier to add support for RELA relocation sections in the future.
1756 template<bool big_endian>
1757 struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian>
1759 elfcpp::Elf_types<32>::Elf_Swxword
1762 const unsigned char*,
1763 const typename Reloc_types<elfcpp::SHT_RELA, 32,
1764 big_endian>::Reloc& reloc) const
1765 { return reloc.get_r_addend(); }
1768 // Cortex_a8_reloc class. We keep record of relocation that may need
1769 // the Cortex-A8 erratum workaround.
1771 class Cortex_a8_reloc
1774 Cortex_a8_reloc(Reloc_stub* reloc_stub, unsigned r_type,
1775 Arm_address destination)
1776 : reloc_stub_(reloc_stub), r_type_(r_type), destination_(destination)
1782 // Accessors: This is a read-only class.
1784 // Return the relocation stub associated with this relocation if there is
1788 { return this->reloc_stub_; }
1790 // Return the relocation type.
1793 { return this->r_type_; }
1795 // Return the destination address of the relocation. LSB stores the THUMB
1799 { return this->destination_; }
1802 // Associated relocation stub if there is one, or NULL.
1803 const Reloc_stub* reloc_stub_;
1805 unsigned int r_type_;
1806 // Destination address of this relocation. LSB is used to distinguish
1808 Arm_address destination_;
1811 // Arm_output_data_got class. We derive this from Output_data_got to add
1812 // extra methods to handle TLS relocations in a static link.
1814 template<bool big_endian>
1815 class Arm_output_data_got : public Output_data_got<32, big_endian>
1818 Arm_output_data_got(Symbol_table* symtab, Layout* layout)
1819 : Output_data_got<32, big_endian>(), symbol_table_(symtab), layout_(layout)
1822 // Add a static entry for the GOT entry at OFFSET. GSYM is a global
1823 // symbol and R_TYPE is the code of a dynamic relocation that needs to be
1824 // applied in a static link.
1826 add_static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1827 { this->static_relocs_.push_back(Static_reloc(got_offset, r_type, gsym)); }
1829 // Add a static reloc for the GOT entry at OFFSET. RELOBJ is an object
1830 // defining a local symbol with INDEX. R_TYPE is the code of a dynamic
1831 // relocation that needs to be applied in a static link.
1833 add_static_reloc(unsigned int got_offset, unsigned int r_type,
1834 Sized_relobj<32, big_endian>* relobj, unsigned int index)
1836 this->static_relocs_.push_back(Static_reloc(got_offset, r_type, relobj,
1840 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
1841 // The first one is initialized to be 1, which is the module index for
1842 // the main executable and the second one 0. A reloc of the type
1843 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
1844 // be applied by gold. GSYM is a global symbol.
1846 add_tls_gd32_with_static_reloc(unsigned int got_type, Symbol* gsym);
1848 // Same as the above but for a local symbol in OBJECT with INDEX.
1850 add_tls_gd32_with_static_reloc(unsigned int got_type,
1851 Sized_relobj<32, big_endian>* object,
1852 unsigned int index);
1855 // Write out the GOT table.
1857 do_write(Output_file*);
1860 // This class represent dynamic relocations that need to be applied by
1861 // gold because we are using TLS relocations in a static link.
1865 Static_reloc(unsigned int got_offset, unsigned int r_type, Symbol* gsym)
1866 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(true)
1867 { this->u_.global.symbol = gsym; }
1869 Static_reloc(unsigned int got_offset, unsigned int r_type,
1870 Sized_relobj<32, big_endian>* relobj, unsigned int index)
1871 : got_offset_(got_offset), r_type_(r_type), symbol_is_global_(false)
1873 this->u_.local.relobj = relobj;
1874 this->u_.local.index = index;
1877 // Return the GOT offset.
1880 { return this->got_offset_; }
1885 { return this->r_type_; }
1887 // Whether the symbol is global or not.
1889 symbol_is_global() const
1890 { return this->symbol_is_global_; }
1892 // For a relocation against a global symbol, the global symbol.
1896 gold_assert(this->symbol_is_global_);
1897 return this->u_.global.symbol;
1900 // For a relocation against a local symbol, the defining object.
1901 Sized_relobj<32, big_endian>*
1904 gold_assert(!this->symbol_is_global_);
1905 return this->u_.local.relobj;
1908 // For a relocation against a local symbol, the local symbol index.
1912 gold_assert(!this->symbol_is_global_);
1913 return this->u_.local.index;
1917 // GOT offset of the entry to which this relocation is applied.
1918 unsigned int got_offset_;
1919 // Type of relocation.
1920 unsigned int r_type_;
1921 // Whether this relocation is against a global symbol.
1922 bool symbol_is_global_;
1923 // A global or local symbol.
1928 // For a global symbol, the symbol itself.
1933 // For a local symbol, the object defining object.
1934 Sized_relobj<32, big_endian>* relobj;
1935 // For a local symbol, the symbol index.
1941 // Symbol table of the output object.
1942 Symbol_table* symbol_table_;
1943 // Layout of the output object.
1945 // Static relocs to be applied to the GOT.
1946 std::vector<Static_reloc> static_relocs_;
1949 // Utilities for manipulating integers of up to 32-bits
1953 // Sign extend an n-bit unsigned integer stored in an uint32_t into
1954 // an int32_t. NO_BITS must be between 1 to 32.
1955 template<int no_bits>
1956 static inline int32_t
1957 sign_extend(uint32_t bits)
1959 gold_assert(no_bits >= 0 && no_bits <= 32);
1961 return static_cast<int32_t>(bits);
1962 uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits);
1964 uint32_t top_bit = 1U << (no_bits - 1);
1965 int32_t as_signed = static_cast<int32_t>(bits);
1966 return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed;
1969 // Detects overflow of an NO_BITS integer stored in a uint32_t.
1970 template<int no_bits>
1972 has_overflow(uint32_t bits)
1974 gold_assert(no_bits >= 0 && no_bits <= 32);
1977 int32_t max = (1 << (no_bits - 1)) - 1;
1978 int32_t min = -(1 << (no_bits - 1));
1979 int32_t as_signed = static_cast<int32_t>(bits);
1980 return as_signed > max || as_signed < min;
1983 // Detects overflow of an NO_BITS integer stored in a uint32_t when it
1984 // fits in the given number of bits as either a signed or unsigned value.
1985 // For example, has_signed_unsigned_overflow<8> would check
1986 // -128 <= bits <= 255
1987 template<int no_bits>
1989 has_signed_unsigned_overflow(uint32_t bits)
1991 gold_assert(no_bits >= 2 && no_bits <= 32);
1994 int32_t max = static_cast<int32_t>((1U << no_bits) - 1);
1995 int32_t min = -(1 << (no_bits - 1));
1996 int32_t as_signed = static_cast<int32_t>(bits);
1997 return as_signed > max || as_signed < min;
2000 // Select bits from A and B using bits in MASK. For each n in [0..31],
2001 // the n-th bit in the result is chosen from the n-th bits of A and B.
2002 // A zero selects A and a one selects B.
2003 static inline uint32_t
2004 bit_select(uint32_t a, uint32_t b, uint32_t mask)
2005 { return (a & ~mask) | (b & mask); }
2008 template<bool big_endian>
2009 class Target_arm : public Sized_target<32, big_endian>
2012 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
2015 // When were are relocating a stub, we pass this as the relocation number.
2016 static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1);
2019 : Sized_target<32, big_endian>(&arm_info),
2020 got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
2021 copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL),
2022 got_mod_index_offset_(-1U), tls_base_symbol_defined_(false),
2023 stub_tables_(), stub_factory_(Stub_factory::get_instance()),
2024 may_use_blx_(false), should_force_pic_veneer_(false),
2025 arm_input_section_map_(), attributes_section_data_(NULL),
2026 fix_cortex_a8_(false), cortex_a8_relocs_info_()
2029 // Whether we can use BLX.
2032 { return this->may_use_blx_; }
2034 // Set use-BLX flag.
2036 set_may_use_blx(bool value)
2037 { this->may_use_blx_ = value; }
2039 // Whether we force PCI branch veneers.
2041 should_force_pic_veneer() const
2042 { return this->should_force_pic_veneer_; }
2044 // Set PIC veneer flag.
2046 set_should_force_pic_veneer(bool value)
2047 { this->should_force_pic_veneer_ = value; }
2049 // Whether we use THUMB-2 instructions.
2051 using_thumb2() const
2053 Object_attribute* attr =
2054 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2055 int arch = attr->int_value();
2056 return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7;
2059 // Whether we use THUMB/THUMB-2 instructions only.
2061 using_thumb_only() const
2063 Object_attribute* attr =
2064 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2066 if (attr->int_value() == elfcpp::TAG_CPU_ARCH_V6_M
2067 || attr->int_value() == elfcpp::TAG_CPU_ARCH_V6S_M)
2069 if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7
2070 && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M)
2072 attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
2073 return attr->int_value() == 'M';
2076 // Whether we have an NOP instruction. If not, use mov r0, r0 instead.
2078 may_use_arm_nop() const
2080 Object_attribute* attr =
2081 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2082 int arch = attr->int_value();
2083 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2084 || arch == elfcpp::TAG_CPU_ARCH_V6K
2085 || arch == elfcpp::TAG_CPU_ARCH_V7
2086 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2089 // Whether we have THUMB-2 NOP.W instruction.
2091 may_use_thumb2_nop() const
2093 Object_attribute* attr =
2094 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
2095 int arch = attr->int_value();
2096 return (arch == elfcpp::TAG_CPU_ARCH_V6T2
2097 || arch == elfcpp::TAG_CPU_ARCH_V7
2098 || arch == elfcpp::TAG_CPU_ARCH_V7E_M);
2101 // Process the relocations to determine unreferenced sections for
2102 // garbage collection.
2104 gc_process_relocs(Symbol_table* symtab,
2106 Sized_relobj<32, big_endian>* object,
2107 unsigned int data_shndx,
2108 unsigned int sh_type,
2109 const unsigned char* prelocs,
2111 Output_section* output_section,
2112 bool needs_special_offset_handling,
2113 size_t local_symbol_count,
2114 const unsigned char* plocal_symbols);
2116 // Scan the relocations to look for symbol adjustments.
2118 scan_relocs(Symbol_table* symtab,
2120 Sized_relobj<32, big_endian>* object,
2121 unsigned int data_shndx,
2122 unsigned int sh_type,
2123 const unsigned char* prelocs,
2125 Output_section* output_section,
2126 bool needs_special_offset_handling,
2127 size_t local_symbol_count,
2128 const unsigned char* plocal_symbols);
2130 // Finalize the sections.
2132 do_finalize_sections(Layout*, const Input_objects*, Symbol_table*);
2134 // Return the value to use for a dynamic symbol which requires special
2137 do_dynsym_value(const Symbol*) const;
2139 // Relocate a section.
2141 relocate_section(const Relocate_info<32, big_endian>*,
2142 unsigned int sh_type,
2143 const unsigned char* prelocs,
2145 Output_section* output_section,
2146 bool needs_special_offset_handling,
2147 unsigned char* view,
2148 Arm_address view_address,
2149 section_size_type view_size,
2150 const Reloc_symbol_changes*);
2152 // Scan the relocs during a relocatable link.
2154 scan_relocatable_relocs(Symbol_table* symtab,
2156 Sized_relobj<32, big_endian>* object,
2157 unsigned int data_shndx,
2158 unsigned int sh_type,
2159 const unsigned char* prelocs,
2161 Output_section* output_section,
2162 bool needs_special_offset_handling,
2163 size_t local_symbol_count,
2164 const unsigned char* plocal_symbols,
2165 Relocatable_relocs*);
2167 // Relocate a section during a relocatable link.
2169 relocate_for_relocatable(const Relocate_info<32, big_endian>*,
2170 unsigned int sh_type,
2171 const unsigned char* prelocs,
2173 Output_section* output_section,
2174 off_t offset_in_output_section,
2175 const Relocatable_relocs*,
2176 unsigned char* view,
2177 Arm_address view_address,
2178 section_size_type view_size,
2179 unsigned char* reloc_view,
2180 section_size_type reloc_view_size);
2182 // Return whether SYM is defined by the ABI.
2184 do_is_defined_by_abi(Symbol* sym) const
2185 { return strcmp(sym->name(), "__tls_get_addr") == 0; }
2187 // Return whether there is a GOT section.
2189 has_got_section() const
2190 { return this->got_ != NULL; }
2192 // Return the size of the GOT section.
2196 gold_assert(this->got_ != NULL);
2197 return this->got_->data_size();
2200 // Map platform-specific reloc types
2202 get_real_reloc_type (unsigned int r_type);
2205 // Methods to support stub-generations.
2208 // Return the stub factory
2210 stub_factory() const
2211 { return this->stub_factory_; }
2213 // Make a new Arm_input_section object.
2214 Arm_input_section<big_endian>*
2215 new_arm_input_section(Relobj*, unsigned int);
2217 // Find the Arm_input_section object corresponding to the SHNDX-th input
2218 // section of RELOBJ.
2219 Arm_input_section<big_endian>*
2220 find_arm_input_section(Relobj* relobj, unsigned int shndx) const;
2222 // Make a new Stub_table
2223 Stub_table<big_endian>*
2224 new_stub_table(Arm_input_section<big_endian>*);
2226 // Scan a section for stub generation.
2228 scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int,
2229 const unsigned char*, size_t, Output_section*,
2230 bool, const unsigned char*, Arm_address,
2235 relocate_stub(Stub*, const Relocate_info<32, big_endian>*,
2236 Output_section*, unsigned char*, Arm_address,
2239 // Get the default ARM target.
2240 static Target_arm<big_endian>*
2243 gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM
2244 && parameters->target().is_big_endian() == big_endian);
2245 return static_cast<Target_arm<big_endian>*>(
2246 parameters->sized_target<32, big_endian>());
2249 // Whether NAME belongs to a mapping symbol.
2251 is_mapping_symbol_name(const char* name)
2255 && (name[1] == 'a' || name[1] == 't' || name[1] == 'd')
2256 && (name[2] == '\0' || name[2] == '.'));
2259 // Whether we work around the Cortex-A8 erratum.
2261 fix_cortex_a8() const
2262 { return this->fix_cortex_a8_; }
2264 // Whether we fix R_ARM_V4BX relocation.
2266 // 1 - replace with MOV instruction (armv4 target)
2267 // 2 - make interworking veneer (>= armv4t targets only)
2268 General_options::Fix_v4bx
2270 { return parameters->options().fix_v4bx(); }
2272 // Scan a span of THUMB code section for Cortex-A8 erratum.
2274 scan_span_for_cortex_a8_erratum(Arm_relobj<big_endian>*, unsigned int,
2275 section_size_type, section_size_type,
2276 const unsigned char*, Arm_address);
2278 // Apply Cortex-A8 workaround to a branch.
2280 apply_cortex_a8_workaround(const Cortex_a8_stub*, Arm_address,
2281 unsigned char*, Arm_address);
2284 // Make an ELF object.
2286 do_make_elf_object(const std::string&, Input_file*, off_t,
2287 const elfcpp::Ehdr<32, big_endian>& ehdr);
2290 do_make_elf_object(const std::string&, Input_file*, off_t,
2291 const elfcpp::Ehdr<32, !big_endian>&)
2292 { gold_unreachable(); }
2295 do_make_elf_object(const std::string&, Input_file*, off_t,
2296 const elfcpp::Ehdr<64, false>&)
2297 { gold_unreachable(); }
2300 do_make_elf_object(const std::string&, Input_file*, off_t,
2301 const elfcpp::Ehdr<64, true>&)
2302 { gold_unreachable(); }
2304 // Make an output section.
2306 do_make_output_section(const char* name, elfcpp::Elf_Word type,
2307 elfcpp::Elf_Xword flags)
2308 { return new Arm_output_section<big_endian>(name, type, flags); }
2311 do_adjust_elf_header(unsigned char* view, int len) const;
2313 // We only need to generate stubs, and hence perform relaxation if we are
2314 // not doing relocatable linking.
2316 do_may_relax() const
2317 { return !parameters->options().relocatable(); }
2320 do_relax(int, const Input_objects*, Symbol_table*, Layout*);
2322 // Determine whether an object attribute tag takes an integer, a
2325 do_attribute_arg_type(int tag) const;
2327 // Reorder tags during output.
2329 do_attributes_order(int num) const;
2331 // This is called when the target is selected as the default.
2333 do_select_as_default_target()
2335 // No locking is required since there should only be one default target.
2336 // We cannot have both the big-endian and little-endian ARM targets
2338 gold_assert(arm_reloc_property_table == NULL);
2339 arm_reloc_property_table = new Arm_reloc_property_table();
2343 // The class which scans relocations.
2348 : issued_non_pic_error_(false)
2352 local(Symbol_table* symtab, Layout* layout, Target_arm* target,
2353 Sized_relobj<32, big_endian>* object,
2354 unsigned int data_shndx,
2355 Output_section* output_section,
2356 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2357 const elfcpp::Sym<32, big_endian>& lsym);
2360 global(Symbol_table* symtab, Layout* layout, Target_arm* target,
2361 Sized_relobj<32, big_endian>* object,
2362 unsigned int data_shndx,
2363 Output_section* output_section,
2364 const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type,
2368 local_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2369 Sized_relobj<32, big_endian>* ,
2372 const elfcpp::Rel<32, big_endian>& ,
2374 const elfcpp::Sym<32, big_endian>&)
2378 global_reloc_may_be_function_pointer(Symbol_table* , Layout* , Target_arm* ,
2379 Sized_relobj<32, big_endian>* ,
2382 const elfcpp::Rel<32, big_endian>& ,
2383 unsigned int , Symbol*)
2388 unsupported_reloc_local(Sized_relobj<32, big_endian>*,
2389 unsigned int r_type);
2392 unsupported_reloc_global(Sized_relobj<32, big_endian>*,
2393 unsigned int r_type, Symbol*);
2396 check_non_pic(Relobj*, unsigned int r_type);
2398 // Almost identical to Symbol::needs_plt_entry except that it also
2399 // handles STT_ARM_TFUNC.
2401 symbol_needs_plt_entry(const Symbol* sym)
2403 // An undefined symbol from an executable does not need a PLT entry.
2404 if (sym->is_undefined() && !parameters->options().shared())
2407 return (!parameters->doing_static_link()
2408 && (sym->type() == elfcpp::STT_FUNC
2409 || sym->type() == elfcpp::STT_ARM_TFUNC)
2410 && (sym->is_from_dynobj()
2411 || sym->is_undefined()
2412 || sym->is_preemptible()));
2415 // Whether we have issued an error about a non-PIC compilation.
2416 bool issued_non_pic_error_;
2419 // The class which implements relocation.
2429 // Return whether the static relocation needs to be applied.
2431 should_apply_static_reloc(const Sized_symbol<32>* gsym,
2434 Output_section* output_section);
2436 // Do a relocation. Return false if the caller should not issue
2437 // any warnings about this relocation.
2439 relocate(const Relocate_info<32, big_endian>*, Target_arm*,
2440 Output_section*, size_t relnum,
2441 const elfcpp::Rel<32, big_endian>&,
2442 unsigned int r_type, const Sized_symbol<32>*,
2443 const Symbol_value<32>*,
2444 unsigned char*, Arm_address,
2447 // Return whether we want to pass flag NON_PIC_REF for this
2448 // reloc. This means the relocation type accesses a symbol not via
2451 reloc_is_non_pic (unsigned int r_type)
2455 // These relocation types reference GOT or PLT entries explicitly.
2456 case elfcpp::R_ARM_GOT_BREL:
2457 case elfcpp::R_ARM_GOT_ABS:
2458 case elfcpp::R_ARM_GOT_PREL:
2459 case elfcpp::R_ARM_GOT_BREL12:
2460 case elfcpp::R_ARM_PLT32_ABS:
2461 case elfcpp::R_ARM_TLS_GD32:
2462 case elfcpp::R_ARM_TLS_LDM32:
2463 case elfcpp::R_ARM_TLS_IE32:
2464 case elfcpp::R_ARM_TLS_IE12GP:
2466 // These relocate types may use PLT entries.
2467 case elfcpp::R_ARM_CALL:
2468 case elfcpp::R_ARM_THM_CALL:
2469 case elfcpp::R_ARM_JUMP24:
2470 case elfcpp::R_ARM_THM_JUMP24:
2471 case elfcpp::R_ARM_THM_JUMP19:
2472 case elfcpp::R_ARM_PLT32:
2473 case elfcpp::R_ARM_THM_XPC22:
2474 case elfcpp::R_ARM_PREL31:
2475 case elfcpp::R_ARM_SBREL31:
2484 // Do a TLS relocation.
2485 inline typename Arm_relocate_functions<big_endian>::Status
2486 relocate_tls(const Relocate_info<32, big_endian>*, Target_arm<big_endian>*,
2487 size_t, const elfcpp::Rel<32, big_endian>&, unsigned int,
2488 const Sized_symbol<32>*, const Symbol_value<32>*,
2489 unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
2494 // A class which returns the size required for a relocation type,
2495 // used while scanning relocs during a relocatable link.
2496 class Relocatable_size_for_reloc
2500 get_size_for_reloc(unsigned int, Relobj*);
2503 // Adjust TLS relocation type based on the options and whether this
2504 // is a local symbol.
2505 static tls::Tls_optimization
2506 optimize_tls_reloc(bool is_final, int r_type);
2508 // Get the GOT section, creating it if necessary.
2509 Arm_output_data_got<big_endian>*
2510 got_section(Symbol_table*, Layout*);
2512 // Get the GOT PLT section.
2514 got_plt_section() const
2516 gold_assert(this->got_plt_ != NULL);
2517 return this->got_plt_;
2520 // Create a PLT entry for a global symbol.
2522 make_plt_entry(Symbol_table*, Layout*, Symbol*);
2524 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
2526 define_tls_base_symbol(Symbol_table*, Layout*);
2528 // Create a GOT entry for the TLS module index.
2530 got_mod_index_entry(Symbol_table* symtab, Layout* layout,
2531 Sized_relobj<32, big_endian>* object);
2533 // Get the PLT section.
2534 const Output_data_plt_arm<big_endian>*
2537 gold_assert(this->plt_ != NULL);
2541 // Get the dynamic reloc section, creating it if necessary.
2543 rel_dyn_section(Layout*);
2545 // Get the section to use for TLS_DESC relocations.
2547 rel_tls_desc_section(Layout*) const;
2549 // Return true if the symbol may need a COPY relocation.
2550 // References from an executable object to non-function symbols
2551 // defined in a dynamic object may need a COPY relocation.
2553 may_need_copy_reloc(Symbol* gsym)
2555 return (gsym->type() != elfcpp::STT_ARM_TFUNC
2556 && gsym->may_need_copy_reloc());
2559 // Add a potential copy relocation.
2561 copy_reloc(Symbol_table* symtab, Layout* layout,
2562 Sized_relobj<32, big_endian>* object,
2563 unsigned int shndx, Output_section* output_section,
2564 Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc)
2566 this->copy_relocs_.copy_reloc(symtab, layout,
2567 symtab->get_sized_symbol<32>(sym),
2568 object, shndx, output_section, reloc,
2569 this->rel_dyn_section(layout));
2572 // Whether two EABI versions are compatible.
2574 are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2);
2576 // Merge processor-specific flags from input object and those in the ELF
2577 // header of the output.
2579 merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word);
2581 // Get the secondary compatible architecture.
2583 get_secondary_compatible_arch(const Attributes_section_data*);
2585 // Set the secondary compatible architecture.
2587 set_secondary_compatible_arch(Attributes_section_data*, int);
2590 tag_cpu_arch_combine(const char*, int, int*, int, int);
2592 // Helper to print AEABI enum tag value.
2594 aeabi_enum_name(unsigned int);
2596 // Return string value for TAG_CPU_name.
2598 tag_cpu_name_value(unsigned int);
2600 // Merge object attributes from input object and those in the output.
2602 merge_object_attributes(const char*, const Attributes_section_data*);
2604 // Helper to get an AEABI object attribute
2606 get_aeabi_object_attribute(int tag) const
2608 Attributes_section_data* pasd = this->attributes_section_data_;
2609 gold_assert(pasd != NULL);
2610 Object_attribute* attr =
2611 pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag);
2612 gold_assert(attr != NULL);
2617 // Methods to support stub-generations.
2620 // Group input sections for stub generation.
2622 group_sections(Layout*, section_size_type, bool);
2624 // Scan a relocation for stub generation.
2626 scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int,
2627 const Sized_symbol<32>*, unsigned int,
2628 const Symbol_value<32>*,
2629 elfcpp::Elf_types<32>::Elf_Swxword, Arm_address);
2631 // Scan a relocation section for stub.
2632 template<int sh_type>
2634 scan_reloc_section_for_stubs(
2635 const Relocate_info<32, big_endian>* relinfo,
2636 const unsigned char* prelocs,
2638 Output_section* output_section,
2639 bool needs_special_offset_handling,
2640 const unsigned char* view,
2641 elfcpp::Elf_types<32>::Elf_Addr view_address,
2644 // Fix .ARM.exidx section coverage.
2646 fix_exidx_coverage(Layout*, Arm_output_section<big_endian>*, Symbol_table*);
2648 // Functors for STL set.
2649 struct output_section_address_less_than
2652 operator()(const Output_section* s1, const Output_section* s2) const
2653 { return s1->address() < s2->address(); }
2656 // Information about this specific target which we pass to the
2657 // general Target structure.
2658 static const Target::Target_info arm_info;
2660 // The types of GOT entries needed for this platform.
2663 GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
2664 GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
2665 GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
2666 GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
2667 GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
2670 typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list;
2672 // Map input section to Arm_input_section.
2673 typedef Unordered_map<Section_id,
2674 Arm_input_section<big_endian>*,
2676 Arm_input_section_map;
2678 // Map output addresses to relocs for Cortex-A8 erratum.
2679 typedef Unordered_map<Arm_address, const Cortex_a8_reloc*>
2680 Cortex_a8_relocs_info;
2683 Arm_output_data_got<big_endian>* got_;
2685 Output_data_plt_arm<big_endian>* plt_;
2686 // The GOT PLT section.
2687 Output_data_space* got_plt_;
2688 // The dynamic reloc section.
2689 Reloc_section* rel_dyn_;
2690 // Relocs saved to avoid a COPY reloc.
2691 Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_;
2692 // Space for variables copied with a COPY reloc.
2693 Output_data_space* dynbss_;
2694 // Offset of the GOT entry for the TLS module index.
2695 unsigned int got_mod_index_offset_;
2696 // True if the _TLS_MODULE_BASE_ symbol has been defined.
2697 bool tls_base_symbol_defined_;
2698 // Vector of Stub_tables created.
2699 Stub_table_list stub_tables_;
2701 const Stub_factory &stub_factory_;
2702 // Whether we can use BLX.
2704 // Whether we force PIC branch veneers.
2705 bool should_force_pic_veneer_;
2706 // Map for locating Arm_input_sections.
2707 Arm_input_section_map arm_input_section_map_;
2708 // Attributes section data in output.
2709 Attributes_section_data* attributes_section_data_;
2710 // Whether we want to fix code for Cortex-A8 erratum.
2711 bool fix_cortex_a8_;
2712 // Map addresses to relocs for Cortex-A8 erratum.
2713 Cortex_a8_relocs_info cortex_a8_relocs_info_;
2716 template<bool big_endian>
2717 const Target::Target_info Target_arm<big_endian>::arm_info =
2720 big_endian, // is_big_endian
2721 elfcpp::EM_ARM, // machine_code
2722 false, // has_make_symbol
2723 false, // has_resolve
2724 false, // has_code_fill
2725 true, // is_default_stack_executable
2727 "/usr/lib/libc.so.1", // dynamic_linker
2728 0x8000, // default_text_segment_address
2729 0x1000, // abi_pagesize (overridable by -z max-page-size)
2730 0x1000, // common_pagesize (overridable by -z common-page-size)
2731 elfcpp::SHN_UNDEF, // small_common_shndx
2732 elfcpp::SHN_UNDEF, // large_common_shndx
2733 0, // small_common_section_flags
2734 0, // large_common_section_flags
2735 ".ARM.attributes", // attributes_section
2736 "aeabi" // attributes_vendor
2739 // Arm relocate functions class
2742 template<bool big_endian>
2743 class Arm_relocate_functions : public Relocate_functions<32, big_endian>
2748 STATUS_OKAY, // No error during relocation.
2749 STATUS_OVERFLOW, // Relocation oveflow.
2750 STATUS_BAD_RELOC // Relocation cannot be applied.
2754 typedef Relocate_functions<32, big_endian> Base;
2755 typedef Arm_relocate_functions<big_endian> This;
2757 // Encoding of imm16 argument for movt and movw ARM instructions
2760 // imm16 := imm4 | imm12
2762 // 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
2763 // +-------+---------------+-------+-------+-----------------------+
2764 // | | |imm4 | |imm12 |
2765 // +-------+---------------+-------+-------+-----------------------+
2767 // Extract the relocation addend from VAL based on the ARM
2768 // instruction encoding described above.
2769 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2770 extract_arm_movw_movt_addend(
2771 typename elfcpp::Swap<32, big_endian>::Valtype val)
2773 // According to the Elf ABI for ARM Architecture the immediate
2774 // field is sign-extended to form the addend.
2775 return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff));
2778 // Insert X into VAL based on the ARM instruction encoding described
2780 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2781 insert_val_arm_movw_movt(
2782 typename elfcpp::Swap<32, big_endian>::Valtype val,
2783 typename elfcpp::Swap<32, big_endian>::Valtype x)
2787 val |= (x & 0xf000) << 4;
2791 // Encoding of imm16 argument for movt and movw Thumb2 instructions
2794 // imm16 := imm4 | i | imm3 | imm8
2796 // 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
2797 // +---------+-+-----------+-------++-+-----+-------+---------------+
2798 // | |i| |imm4 || |imm3 | |imm8 |
2799 // +---------+-+-----------+-------++-+-----+-------+---------------+
2801 // Extract the relocation addend from VAL based on the Thumb2
2802 // instruction encoding described above.
2803 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2804 extract_thumb_movw_movt_addend(
2805 typename elfcpp::Swap<32, big_endian>::Valtype val)
2807 // According to the Elf ABI for ARM Architecture the immediate
2808 // field is sign-extended to form the addend.
2809 return utils::sign_extend<16>(((val >> 4) & 0xf000)
2810 | ((val >> 15) & 0x0800)
2811 | ((val >> 4) & 0x0700)
2815 // Insert X into VAL based on the Thumb2 instruction encoding
2817 static inline typename elfcpp::Swap<32, big_endian>::Valtype
2818 insert_val_thumb_movw_movt(
2819 typename elfcpp::Swap<32, big_endian>::Valtype val,
2820 typename elfcpp::Swap<32, big_endian>::Valtype x)
2823 val |= (x & 0xf000) << 4;
2824 val |= (x & 0x0800) << 15;
2825 val |= (x & 0x0700) << 4;
2826 val |= (x & 0x00ff);
2830 // Calculate the smallest constant Kn for the specified residual.
2831 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2833 calc_grp_kn(typename elfcpp::Swap<32, big_endian>::Valtype residual)
2839 // Determine the most significant bit in the residual and
2840 // align the resulting value to a 2-bit boundary.
2841 for (msb = 30; (msb >= 0) && !(residual & (3 << msb)); msb -= 2)
2843 // The desired shift is now (msb - 6), or zero, whichever
2845 return (((msb - 6) < 0) ? 0 : (msb - 6));
2848 // Calculate the final residual for the specified group index.
2849 // If the passed group index is less than zero, the method will return
2850 // the value of the specified residual without any change.
2851 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2852 static typename elfcpp::Swap<32, big_endian>::Valtype
2853 calc_grp_residual(typename elfcpp::Swap<32, big_endian>::Valtype residual,
2856 for (int n = 0; n <= group; n++)
2858 // Calculate which part of the value to mask.
2859 uint32_t shift = calc_grp_kn(residual);
2860 // Calculate the residual for the next time around.
2861 residual &= ~(residual & (0xff << shift));
2867 // Calculate the value of Gn for the specified group index.
2868 // We return it in the form of an encoded constant-and-rotation.
2869 // (see (AAELF 4.6.1.4 Static ARM relocations, Group Relocations, p.32)
2870 static typename elfcpp::Swap<32, big_endian>::Valtype
2871 calc_grp_gn(typename elfcpp::Swap<32, big_endian>::Valtype residual,
2874 typename elfcpp::Swap<32, big_endian>::Valtype gn = 0;
2877 for (int n = 0; n <= group; n++)
2879 // Calculate which part of the value to mask.
2880 shift = calc_grp_kn(residual);
2881 // Calculate Gn in 32-bit as well as encoded constant-and-rotation form.
2882 gn = residual & (0xff << shift);
2883 // Calculate the residual for the next time around.
2886 // Return Gn in the form of an encoded constant-and-rotation.
2887 return ((gn >> shift) | ((gn <= 0xff ? 0 : (32 - shift) / 2) << 8));
2891 // Handle ARM long branches.
2892 static typename This::Status
2893 arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
2894 unsigned char *, const Sized_symbol<32>*,
2895 const Arm_relobj<big_endian>*, unsigned int,
2896 const Symbol_value<32>*, Arm_address, Arm_address, bool);
2898 // Handle THUMB long branches.
2899 static typename This::Status
2900 thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*,
2901 unsigned char *, const Sized_symbol<32>*,
2902 const Arm_relobj<big_endian>*, unsigned int,
2903 const Symbol_value<32>*, Arm_address, Arm_address, bool);
2906 // Return the branch offset of a 32-bit THUMB branch.
2907 static inline int32_t
2908 thumb32_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
2910 // We use the Thumb-2 encoding (backwards compatible with Thumb-1)
2911 // involving the J1 and J2 bits.
2912 uint32_t s = (upper_insn & (1U << 10)) >> 10;
2913 uint32_t upper = upper_insn & 0x3ffU;
2914 uint32_t lower = lower_insn & 0x7ffU;
2915 uint32_t j1 = (lower_insn & (1U << 13)) >> 13;
2916 uint32_t j2 = (lower_insn & (1U << 11)) >> 11;
2917 uint32_t i1 = j1 ^ s ? 0 : 1;
2918 uint32_t i2 = j2 ^ s ? 0 : 1;
2920 return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22)
2921 | (upper << 12) | (lower << 1));
2924 // Insert OFFSET to a 32-bit THUMB branch and return the upper instruction.
2925 // UPPER_INSN is the original upper instruction of the branch. Caller is
2926 // responsible for overflow checking and BLX offset adjustment.
2927 static inline uint16_t
2928 thumb32_branch_upper(uint16_t upper_insn, int32_t offset)
2930 uint32_t s = offset < 0 ? 1 : 0;
2931 uint32_t bits = static_cast<uint32_t>(offset);
2932 return (upper_insn & ~0x7ffU) | ((bits >> 12) & 0x3ffU) | (s << 10);
2935 // Insert OFFSET to a 32-bit THUMB branch and return the lower instruction.
2936 // LOWER_INSN is the original lower instruction of the branch. Caller is
2937 // responsible for overflow checking and BLX offset adjustment.
2938 static inline uint16_t
2939 thumb32_branch_lower(uint16_t lower_insn, int32_t offset)
2941 uint32_t s = offset < 0 ? 1 : 0;
2942 uint32_t bits = static_cast<uint32_t>(offset);
2943 return ((lower_insn & ~0x2fffU)
2944 | ((((bits >> 23) & 1) ^ !s) << 13)
2945 | ((((bits >> 22) & 1) ^ !s) << 11)
2946 | ((bits >> 1) & 0x7ffU));
2949 // Return the branch offset of a 32-bit THUMB conditional branch.
2950 static inline int32_t
2951 thumb32_cond_branch_offset(uint16_t upper_insn, uint16_t lower_insn)
2953 uint32_t s = (upper_insn & 0x0400U) >> 10;
2954 uint32_t j1 = (lower_insn & 0x2000U) >> 13;
2955 uint32_t j2 = (lower_insn & 0x0800U) >> 11;
2956 uint32_t lower = (lower_insn & 0x07ffU);
2957 uint32_t upper = (s << 8) | (j2 << 7) | (j1 << 6) | (upper_insn & 0x003fU);
2959 return utils::sign_extend<21>((upper << 12) | (lower << 1));
2962 // Insert OFFSET to a 32-bit THUMB conditional branch and return the upper
2963 // instruction. UPPER_INSN is the original upper instruction of the branch.
2964 // Caller is responsible for overflow checking.
2965 static inline uint16_t
2966 thumb32_cond_branch_upper(uint16_t upper_insn, int32_t offset)
2968 uint32_t s = offset < 0 ? 1 : 0;
2969 uint32_t bits = static_cast<uint32_t>(offset);
2970 return (upper_insn & 0xfbc0U) | (s << 10) | ((bits & 0x0003f000U) >> 12);
2973 // Insert OFFSET to a 32-bit THUMB conditional branch and return the lower
2974 // instruction. LOWER_INSN is the original lower instruction of the branch.
2975 // Caller is reponsible for overflow checking.
2976 static inline uint16_t
2977 thumb32_cond_branch_lower(uint16_t lower_insn, int32_t offset)
2979 uint32_t bits = static_cast<uint32_t>(offset);
2980 uint32_t j2 = (bits & 0x00080000U) >> 19;
2981 uint32_t j1 = (bits & 0x00040000U) >> 18;
2982 uint32_t lo = (bits & 0x00000ffeU) >> 1;
2984 return (lower_insn & 0xd000U) | (j1 << 13) | (j2 << 11) | lo;
2987 // R_ARM_ABS8: S + A
2988 static inline typename This::Status
2989 abs8(unsigned char *view,
2990 const Sized_relobj<32, big_endian>* object,
2991 const Symbol_value<32>* psymval)
2993 typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype;
2994 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
2995 Valtype* wv = reinterpret_cast<Valtype*>(view);
2996 Valtype val = elfcpp::Swap<8, big_endian>::readval(wv);
2997 Reltype addend = utils::sign_extend<8>(val);
2998 Reltype x = psymval->value(object, addend);
2999 val = utils::bit_select(val, x, 0xffU);
3000 elfcpp::Swap<8, big_endian>::writeval(wv, val);
3002 // R_ARM_ABS8 permits signed or unsigned results.
3003 int signed_x = static_cast<int32_t>(x);
3004 return ((signed_x < -128 || signed_x > 255)
3005 ? This::STATUS_OVERFLOW
3006 : This::STATUS_OKAY);
3009 // R_ARM_THM_ABS5: S + A
3010 static inline typename This::Status
3011 thm_abs5(unsigned char *view,
3012 const Sized_relobj<32, big_endian>* object,
3013 const Symbol_value<32>* psymval)
3015 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3016 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3017 Valtype* wv = reinterpret_cast<Valtype*>(view);
3018 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3019 Reltype addend = (val & 0x7e0U) >> 6;
3020 Reltype x = psymval->value(object, addend);
3021 val = utils::bit_select(val, x << 6, 0x7e0U);
3022 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3024 // R_ARM_ABS16 permits signed or unsigned results.
3025 int signed_x = static_cast<int32_t>(x);
3026 return ((signed_x < -32768 || signed_x > 65535)
3027 ? This::STATUS_OVERFLOW
3028 : This::STATUS_OKAY);
3031 // R_ARM_ABS12: S + A
3032 static inline typename This::Status
3033 abs12(unsigned char *view,
3034 const Sized_relobj<32, big_endian>* object,
3035 const Symbol_value<32>* psymval)
3037 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3038 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3039 Valtype* wv = reinterpret_cast<Valtype*>(view);
3040 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3041 Reltype addend = val & 0x0fffU;
3042 Reltype x = psymval->value(object, addend);
3043 val = utils::bit_select(val, x, 0x0fffU);
3044 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3045 return (utils::has_overflow<12>(x)
3046 ? This::STATUS_OVERFLOW
3047 : This::STATUS_OKAY);
3050 // R_ARM_ABS16: S + A
3051 static inline typename This::Status
3052 abs16(unsigned char *view,
3053 const Sized_relobj<32, big_endian>* object,
3054 const Symbol_value<32>* psymval)
3056 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3057 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3058 Valtype* wv = reinterpret_cast<Valtype*>(view);
3059 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3060 Reltype addend = utils::sign_extend<16>(val);
3061 Reltype x = psymval->value(object, addend);
3062 val = utils::bit_select(val, x, 0xffffU);
3063 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3064 return (utils::has_signed_unsigned_overflow<16>(x)
3065 ? This::STATUS_OVERFLOW
3066 : This::STATUS_OKAY);
3069 // R_ARM_ABS32: (S + A) | T
3070 static inline typename This::Status
3071 abs32(unsigned char *view,
3072 const Sized_relobj<32, big_endian>* object,
3073 const Symbol_value<32>* psymval,
3074 Arm_address thumb_bit)
3076 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3077 Valtype* wv = reinterpret_cast<Valtype*>(view);
3078 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3079 Valtype x = psymval->value(object, addend) | thumb_bit;
3080 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3081 return This::STATUS_OKAY;
3084 // R_ARM_REL32: (S + A) | T - P
3085 static inline typename This::Status
3086 rel32(unsigned char *view,
3087 const Sized_relobj<32, big_endian>* object,
3088 const Symbol_value<32>* psymval,
3089 Arm_address address,
3090 Arm_address thumb_bit)
3092 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3093 Valtype* wv = reinterpret_cast<Valtype*>(view);
3094 Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv);
3095 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3096 elfcpp::Swap<32, big_endian>::writeval(wv, x);
3097 return This::STATUS_OKAY;
3100 // R_ARM_THM_JUMP24: (S + A) | T - P
3101 static typename This::Status
3102 thm_jump19(unsigned char *view, const Arm_relobj<big_endian>* object,
3103 const Symbol_value<32>* psymval, Arm_address address,
3104 Arm_address thumb_bit);
3106 // R_ARM_THM_JUMP6: S + A – P
3107 static inline typename This::Status
3108 thm_jump6(unsigned char *view,
3109 const Sized_relobj<32, big_endian>* object,
3110 const Symbol_value<32>* psymval,
3111 Arm_address address)
3113 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3114 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3115 Valtype* wv = reinterpret_cast<Valtype*>(view);
3116 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3117 // bit[9]:bit[7:3]:’0’ (mask: 0x02f8)
3118 Reltype addend = (((val & 0x0200) >> 3) | ((val & 0x00f8) >> 2));
3119 Reltype x = (psymval->value(object, addend) - address);
3120 val = (val & 0xfd07) | ((x & 0x0040) << 3) | ((val & 0x003e) << 2);
3121 elfcpp::Swap<16, big_endian>::writeval(wv, val);
3122 // CZB does only forward jumps.
3123 return ((x > 0x007e)
3124 ? This::STATUS_OVERFLOW
3125 : This::STATUS_OKAY);
3128 // R_ARM_THM_JUMP8: S + A – P
3129 static inline typename This::Status
3130 thm_jump8(unsigned char *view,
3131 const Sized_relobj<32, big_endian>* object,
3132 const Symbol_value<32>* psymval,
3133 Arm_address address)
3135 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3136 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3137 Valtype* wv = reinterpret_cast<Valtype*>(view);
3138 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3139 Reltype addend = utils::sign_extend<8>((val & 0x00ff) << 1);
3140 Reltype x = (psymval->value(object, addend) - address);
3141 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xff00) | ((x & 0x01fe) >> 1));
3142 return (utils::has_overflow<8>(x)
3143 ? This::STATUS_OVERFLOW
3144 : This::STATUS_OKAY);
3147 // R_ARM_THM_JUMP11: S + A – P
3148 static inline typename This::Status
3149 thm_jump11(unsigned char *view,
3150 const Sized_relobj<32, big_endian>* object,
3151 const Symbol_value<32>* psymval,
3152 Arm_address address)
3154 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3155 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3156 Valtype* wv = reinterpret_cast<Valtype*>(view);
3157 Valtype val = elfcpp::Swap<16, big_endian>::readval(wv);
3158 Reltype addend = utils::sign_extend<11>((val & 0x07ff) << 1);
3159 Reltype x = (psymval->value(object, addend) - address);
3160 elfcpp::Swap<16, big_endian>::writeval(wv, (val & 0xf800) | ((x & 0x0ffe) >> 1));
3161 return (utils::has_overflow<11>(x)
3162 ? This::STATUS_OVERFLOW
3163 : This::STATUS_OKAY);
3166 // R_ARM_BASE_PREL: B(S) + A - P
3167 static inline typename This::Status
3168 base_prel(unsigned char* view,
3170 Arm_address address)
3172 Base::rel32(view, origin - address);
3176 // R_ARM_BASE_ABS: B(S) + A
3177 static inline typename This::Status
3178 base_abs(unsigned char* view,
3181 Base::rel32(view, origin);
3185 // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG
3186 static inline typename This::Status
3187 got_brel(unsigned char* view,
3188 typename elfcpp::Swap<32, big_endian>::Valtype got_offset)
3190 Base::rel32(view, got_offset);
3191 return This::STATUS_OKAY;
3194 // R_ARM_GOT_PREL: GOT(S) + A - P
3195 static inline typename This::Status
3196 got_prel(unsigned char *view,
3197 Arm_address got_entry,
3198 Arm_address address)
3200 Base::rel32(view, got_entry - address);
3201 return This::STATUS_OKAY;
3204 // R_ARM_PREL: (S + A) | T - P
3205 static inline typename This::Status
3206 prel31(unsigned char *view,
3207 const Sized_relobj<32, big_endian>* object,
3208 const Symbol_value<32>* psymval,
3209 Arm_address address,
3210 Arm_address thumb_bit)
3212 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3213 Valtype* wv = reinterpret_cast<Valtype*>(view);
3214 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3215 Valtype addend = utils::sign_extend<31>(val);
3216 Valtype x = (psymval->value(object, addend) | thumb_bit) - address;
3217 val = utils::bit_select(val, x, 0x7fffffffU);
3218 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3219 return (utils::has_overflow<31>(x) ?
3220 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3223 // R_ARM_MOVW_ABS_NC: (S + A) | T (relative address base is )
3224 // R_ARM_MOVW_PREL_NC: (S + A) | T - P
3225 // R_ARM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3226 // R_ARM_MOVW_BREL: ((S + A) | T) - B(S)
3227 static inline typename This::Status
3228 movw(unsigned char* view,
3229 const Sized_relobj<32, big_endian>* object,
3230 const Symbol_value<32>* psymval,
3231 Arm_address relative_address_base,
3232 Arm_address thumb_bit,
3233 bool check_overflow)
3235 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3236 Valtype* wv = reinterpret_cast<Valtype*>(view);
3237 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3238 Valtype addend = This::extract_arm_movw_movt_addend(val);
3239 Valtype x = ((psymval->value(object, addend) | thumb_bit)
3240 - relative_address_base);
3241 val = This::insert_val_arm_movw_movt(val, x);
3242 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3243 return ((check_overflow && utils::has_overflow<16>(x))
3244 ? This::STATUS_OVERFLOW
3245 : This::STATUS_OKAY);
3248 // R_ARM_MOVT_ABS: S + A (relative address base is 0)
3249 // R_ARM_MOVT_PREL: S + A - P
3250 // R_ARM_MOVT_BREL: S + A - B(S)
3251 static inline typename This::Status
3252 movt(unsigned char* view,
3253 const Sized_relobj<32, big_endian>* object,
3254 const Symbol_value<32>* psymval,
3255 Arm_address relative_address_base)
3257 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3258 Valtype* wv = reinterpret_cast<Valtype*>(view);
3259 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3260 Valtype addend = This::extract_arm_movw_movt_addend(val);
3261 Valtype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3262 val = This::insert_val_arm_movw_movt(val, x);
3263 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3264 // FIXME: IHI0044D says that we should check for overflow.
3265 return This::STATUS_OKAY;
3268 // R_ARM_THM_MOVW_ABS_NC: S + A | T (relative_address_base is 0)
3269 // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P
3270 // R_ARM_THM_MOVW_BREL_NC: ((S + A) | T) - B(S)
3271 // R_ARM_THM_MOVW_BREL: ((S + A) | T) - B(S)
3272 static inline typename This::Status
3273 thm_movw(unsigned char *view,
3274 const Sized_relobj<32, big_endian>* object,
3275 const Symbol_value<32>* psymval,
3276 Arm_address relative_address_base,
3277 Arm_address thumb_bit,
3278 bool check_overflow)
3280 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3281 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3282 Valtype* wv = reinterpret_cast<Valtype*>(view);
3283 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3284 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3285 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3287 (psymval->value(object, addend) | thumb_bit) - relative_address_base;
3288 val = This::insert_val_thumb_movw_movt(val, x);
3289 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3290 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3291 return ((check_overflow && utils::has_overflow<16>(x))
3292 ? This::STATUS_OVERFLOW
3293 : This::STATUS_OKAY);
3296 // R_ARM_THM_MOVT_ABS: S + A (relative address base is 0)
3297 // R_ARM_THM_MOVT_PREL: S + A - P
3298 // R_ARM_THM_MOVT_BREL: S + A - B(S)
3299 static inline typename This::Status
3300 thm_movt(unsigned char* view,
3301 const Sized_relobj<32, big_endian>* object,
3302 const Symbol_value<32>* psymval,
3303 Arm_address relative_address_base)
3305 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3306 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3307 Valtype* wv = reinterpret_cast<Valtype*>(view);
3308 Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3309 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3310 Reltype addend = This::extract_thumb_movw_movt_addend(val);
3311 Reltype x = (psymval->value(object, addend) - relative_address_base) >> 16;
3312 val = This::insert_val_thumb_movw_movt(val, x);
3313 elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16);
3314 elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff);
3315 return This::STATUS_OKAY;
3318 // R_ARM_THM_ALU_PREL_11_0: ((S + A) | T) - Pa (Thumb32)
3319 static inline typename This::Status
3320 thm_alu11(unsigned char* view,
3321 const Sized_relobj<32, big_endian>* object,
3322 const Symbol_value<32>* psymval,
3323 Arm_address address,
3324 Arm_address thumb_bit)
3326 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3327 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3328 Valtype* wv = reinterpret_cast<Valtype*>(view);
3329 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3330 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3332 // 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
3333 // -----------------------------------------------------------------------
3334 // ADD{S} 1 1 1 1 0|i|0|1 0 0 0|S|1 1 0 1||0|imm3 |Rd |imm8
3335 // ADDW 1 1 1 1 0|i|1|0 0 0 0|0|1 1 0 1||0|imm3 |Rd |imm8
3336 // ADR[+] 1 1 1 1 0|i|1|0 0 0 0|0|1 1 1 1||0|imm3 |Rd |imm8
3337 // SUB{S} 1 1 1 1 0|i|0|1 1 0 1|S|1 1 0 1||0|imm3 |Rd |imm8
3338 // SUBW 1 1 1 1 0|i|1|0 1 0 1|0|1 1 0 1||0|imm3 |Rd |imm8
3339 // ADR[-] 1 1 1 1 0|i|1|0 1 0 1|0|1 1 1 1||0|imm3 |Rd |imm8
3341 // Determine a sign for the addend.
3342 const int sign = ((insn & 0xf8ef0000) == 0xf0ad0000
3343 || (insn & 0xf8ef0000) == 0xf0af0000) ? -1 : 1;
3344 // Thumb2 addend encoding:
3345 // imm12 := i | imm3 | imm8
3346 int32_t addend = (insn & 0xff)
3347 | ((insn & 0x00007000) >> 4)
3348 | ((insn & 0x04000000) >> 15);
3349 // Apply a sign to the added.
3352 int32_t x = (psymval->value(object, addend) | thumb_bit)
3353 - (address & 0xfffffffc);
3354 Reltype val = abs(x);
3355 // Mask out the value and a distinct part of the ADD/SUB opcode
3356 // (bits 7:5 of opword).
3357 insn = (insn & 0xfb0f8f00)
3359 | ((val & 0x700) << 4)
3360 | ((val & 0x800) << 15);
3361 // Set the opcode according to whether the value to go in the
3362 // place is negative.
3366 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3367 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3368 return ((val > 0xfff) ?
3369 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3372 // R_ARM_THM_PC8: S + A - Pa (Thumb)
3373 static inline typename This::Status
3374 thm_pc8(unsigned char* view,
3375 const Sized_relobj<32, big_endian>* object,
3376 const Symbol_value<32>* psymval,
3377 Arm_address address)
3379 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3380 typedef typename elfcpp::Swap<16, big_endian>::Valtype Reltype;
3381 Valtype* wv = reinterpret_cast<Valtype*>(view);
3382 Valtype insn = elfcpp::Swap<16, big_endian>::readval(wv);
3383 Reltype addend = ((insn & 0x00ff) << 2);
3384 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3385 Reltype val = abs(x);
3386 insn = (insn & 0xff00) | ((val & 0x03fc) >> 2);
3388 elfcpp::Swap<16, big_endian>::writeval(wv, insn);
3389 return ((val > 0x03fc)
3390 ? This::STATUS_OVERFLOW
3391 : This::STATUS_OKAY);
3394 // R_ARM_THM_PC12: S + A - Pa (Thumb32)
3395 static inline typename This::Status
3396 thm_pc12(unsigned char* view,
3397 const Sized_relobj<32, big_endian>* object,
3398 const Symbol_value<32>* psymval,
3399 Arm_address address)
3401 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3402 typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype;
3403 Valtype* wv = reinterpret_cast<Valtype*>(view);
3404 Reltype insn = (elfcpp::Swap<16, big_endian>::readval(wv) << 16)
3405 | elfcpp::Swap<16, big_endian>::readval(wv + 1);
3406 // Determine a sign for the addend (positive if the U bit is 1).
3407 const int sign = (insn & 0x00800000) ? 1 : -1;
3408 int32_t addend = (insn & 0xfff);
3409 // Apply a sign to the added.
3412 int32_t x = (psymval->value(object, addend) - (address & 0xfffffffc));
3413 Reltype val = abs(x);
3414 // Mask out and apply the value and the U bit.
3415 insn = (insn & 0xff7ff000) | (val & 0xfff);
3416 // Set the U bit according to whether the value to go in the
3417 // place is positive.
3421 elfcpp::Swap<16, big_endian>::writeval(wv, insn >> 16);
3422 elfcpp::Swap<16, big_endian>::writeval(wv + 1, insn & 0xffff);
3423 return ((val > 0xfff) ?
3424 This::STATUS_OVERFLOW : This::STATUS_OKAY);
3428 static inline typename This::Status
3429 v4bx(const Relocate_info<32, big_endian>* relinfo,
3430 unsigned char *view,
3431 const Arm_relobj<big_endian>* object,
3432 const Arm_address address,
3433 const bool is_interworking)
3436 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3437 Valtype* wv = reinterpret_cast<Valtype*>(view);
3438 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3440 // Ensure that we have a BX instruction.
3441 gold_assert((val & 0x0ffffff0) == 0x012fff10);
3442 const uint32_t reg = (val & 0xf);
3443 if (is_interworking && reg != 0xf)
3445 Stub_table<big_endian>* stub_table =
3446 object->stub_table(relinfo->data_shndx);
3447 gold_assert(stub_table != NULL);
3449 Arm_v4bx_stub* stub = stub_table->find_arm_v4bx_stub(reg);
3450 gold_assert(stub != NULL);
3452 int32_t veneer_address =
3453 stub_table->address() + stub->offset() - 8 - address;
3454 gold_assert((veneer_address <= ARM_MAX_FWD_BRANCH_OFFSET)
3455 && (veneer_address >= ARM_MAX_BWD_BRANCH_OFFSET));
3456 // Replace with a branch to veneer (B <addr>)
3457 val = (val & 0xf0000000) | 0x0a000000
3458 | ((veneer_address >> 2) & 0x00ffffff);
3462 // Preserve Rm (lowest four bits) and the condition code
3463 // (highest four bits). Other bits encode MOV PC,Rm.
3464 val = (val & 0xf000000f) | 0x01a0f000;
3466 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3467 return This::STATUS_OKAY;
3470 // R_ARM_ALU_PC_G0_NC: ((S + A) | T) - P
3471 // R_ARM_ALU_PC_G0: ((S + A) | T) - P
3472 // R_ARM_ALU_PC_G1_NC: ((S + A) | T) - P
3473 // R_ARM_ALU_PC_G1: ((S + A) | T) - P
3474 // R_ARM_ALU_PC_G2: ((S + A) | T) - P
3475 // R_ARM_ALU_SB_G0_NC: ((S + A) | T) - B(S)
3476 // R_ARM_ALU_SB_G0: ((S + A) | T) - B(S)
3477 // R_ARM_ALU_SB_G1_NC: ((S + A) | T) - B(S)
3478 // R_ARM_ALU_SB_G1: ((S + A) | T) - B(S)
3479 // R_ARM_ALU_SB_G2: ((S + A) | T) - B(S)
3480 static inline typename This::Status
3481 arm_grp_alu(unsigned char* view,
3482 const Sized_relobj<32, big_endian>* object,
3483 const Symbol_value<32>* psymval,
3485 Arm_address address,
3486 Arm_address thumb_bit,
3487 bool check_overflow)
3489 gold_assert(group >= 0 && group < 3);
3490 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3491 Valtype* wv = reinterpret_cast<Valtype*>(view);
3492 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3494 // ALU group relocations are allowed only for the ADD/SUB instructions.
3495 // (0x00800000 - ADD, 0x00400000 - SUB)
3496 const Valtype opcode = insn & 0x01e00000;
3497 if (opcode != 0x00800000 && opcode != 0x00400000)
3498 return This::STATUS_BAD_RELOC;
3500 // Determine a sign for the addend.
3501 const int sign = (opcode == 0x00800000) ? 1 : -1;
3502 // shifter = rotate_imm * 2
3503 const uint32_t shifter = (insn & 0xf00) >> 7;
3504 // Initial addend value.
3505 int32_t addend = insn & 0xff;
3506 // Rotate addend right by shifter.
3507 addend = (addend >> shifter) | (addend << (32 - shifter));
3508 // Apply a sign to the added.
3511 int32_t x = ((psymval->value(object, addend) | thumb_bit) - address);
3512 Valtype gn = Arm_relocate_functions::calc_grp_gn(abs(x), group);
3513 // Check for overflow if required
3515 && (Arm_relocate_functions::calc_grp_residual(abs(x), group) != 0))
3516 return This::STATUS_OVERFLOW;
3518 // Mask out the value and the ADD/SUB part of the opcode; take care
3519 // not to destroy the S bit.
3521 // Set the opcode according to whether the value to go in the
3522 // place is negative.
3523 insn |= ((x < 0) ? 0x00400000 : 0x00800000);
3524 // Encode the offset (encoded Gn).
3527 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3528 return This::STATUS_OKAY;
3531 // R_ARM_LDR_PC_G0: S + A - P
3532 // R_ARM_LDR_PC_G1: S + A - P
3533 // R_ARM_LDR_PC_G2: S + A - P
3534 // R_ARM_LDR_SB_G0: S + A - B(S)
3535 // R_ARM_LDR_SB_G1: S + A - B(S)
3536 // R_ARM_LDR_SB_G2: S + A - B(S)
3537 static inline typename This::Status
3538 arm_grp_ldr(unsigned char* view,
3539 const Sized_relobj<32, big_endian>* object,
3540 const Symbol_value<32>* psymval,
3542 Arm_address address)
3544 gold_assert(group >= 0 && group < 3);
3545 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3546 Valtype* wv = reinterpret_cast<Valtype*>(view);
3547 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3549 const int sign = (insn & 0x00800000) ? 1 : -1;
3550 int32_t addend = (insn & 0xfff) * sign;
3551 int32_t x = (psymval->value(object, addend) - address);
3552 // Calculate the relevant G(n-1) value to obtain this stage residual.
3554 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3555 if (residual >= 0x1000)
3556 return This::STATUS_OVERFLOW;
3558 // Mask out the value and U bit.
3560 // Set the U bit for non-negative values.
3565 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3566 return This::STATUS_OKAY;
3569 // R_ARM_LDRS_PC_G0: S + A - P
3570 // R_ARM_LDRS_PC_G1: S + A - P
3571 // R_ARM_LDRS_PC_G2: S + A - P
3572 // R_ARM_LDRS_SB_G0: S + A - B(S)
3573 // R_ARM_LDRS_SB_G1: S + A - B(S)
3574 // R_ARM_LDRS_SB_G2: S + A - B(S)
3575 static inline typename This::Status
3576 arm_grp_ldrs(unsigned char* view,
3577 const Sized_relobj<32, big_endian>* object,
3578 const Symbol_value<32>* psymval,
3580 Arm_address address)
3582 gold_assert(group >= 0 && group < 3);
3583 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3584 Valtype* wv = reinterpret_cast<Valtype*>(view);
3585 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3587 const int sign = (insn & 0x00800000) ? 1 : -1;
3588 int32_t addend = (((insn & 0xf00) >> 4) + (insn & 0xf)) * sign;
3589 int32_t x = (psymval->value(object, addend) - address);
3590 // Calculate the relevant G(n-1) value to obtain this stage residual.
3592 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3593 if (residual >= 0x100)
3594 return This::STATUS_OVERFLOW;
3596 // Mask out the value and U bit.
3598 // Set the U bit for non-negative values.
3601 insn |= ((residual & 0xf0) << 4) | (residual & 0xf);
3603 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3604 return This::STATUS_OKAY;
3607 // R_ARM_LDC_PC_G0: S + A - P
3608 // R_ARM_LDC_PC_G1: S + A - P
3609 // R_ARM_LDC_PC_G2: S + A - P
3610 // R_ARM_LDC_SB_G0: S + A - B(S)
3611 // R_ARM_LDC_SB_G1: S + A - B(S)
3612 // R_ARM_LDC_SB_G2: S + A - B(S)
3613 static inline typename This::Status
3614 arm_grp_ldc(unsigned char* view,
3615 const Sized_relobj<32, big_endian>* object,
3616 const Symbol_value<32>* psymval,
3618 Arm_address address)
3620 gold_assert(group >= 0 && group < 3);
3621 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3622 Valtype* wv = reinterpret_cast<Valtype*>(view);
3623 Valtype insn = elfcpp::Swap<32, big_endian>::readval(wv);
3625 const int sign = (insn & 0x00800000) ? 1 : -1;
3626 int32_t addend = ((insn & 0xff) << 2) * sign;
3627 int32_t x = (psymval->value(object, addend) - address);
3628 // Calculate the relevant G(n-1) value to obtain this stage residual.
3630 Arm_relocate_functions::calc_grp_residual(abs(x), group - 1);
3631 if ((residual & 0x3) != 0 || residual >= 0x400)
3632 return This::STATUS_OVERFLOW;
3634 // Mask out the value and U bit.
3636 // Set the U bit for non-negative values.
3639 insn |= (residual >> 2);
3641 elfcpp::Swap<32, big_endian>::writeval(wv, insn);
3642 return This::STATUS_OKAY;
3646 // Relocate ARM long branches. This handles relocation types
3647 // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25.
3648 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3649 // undefined and we do not use PLT in this relocation. In such a case,
3650 // the branch is converted into an NOP.
3652 template<bool big_endian>
3653 typename Arm_relocate_functions<big_endian>::Status
3654 Arm_relocate_functions<big_endian>::arm_branch_common(
3655 unsigned int r_type,
3656 const Relocate_info<32, big_endian>* relinfo,
3657 unsigned char *view,
3658 const Sized_symbol<32>* gsym,
3659 const Arm_relobj<big_endian>* object,
3661 const Symbol_value<32>* psymval,
3662 Arm_address address,
3663 Arm_address thumb_bit,
3664 bool is_weakly_undefined_without_plt)
3666 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
3667 Valtype* wv = reinterpret_cast<Valtype*>(view);
3668 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
3670 bool insn_is_b = (((val >> 28) & 0xf) <= 0xe)
3671 && ((val & 0x0f000000UL) == 0x0a000000UL);
3672 bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL;
3673 bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe)
3674 && ((val & 0x0f000000UL) == 0x0b000000UL);
3675 bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL;
3676 bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL;
3678 // Check that the instruction is valid.
3679 if (r_type == elfcpp::R_ARM_CALL)
3681 if (!insn_is_uncond_bl && !insn_is_blx)
3682 return This::STATUS_BAD_RELOC;
3684 else if (r_type == elfcpp::R_ARM_JUMP24)
3686 if (!insn_is_b && !insn_is_cond_bl)
3687 return This::STATUS_BAD_RELOC;
3689 else if (r_type == elfcpp::R_ARM_PLT32)
3691 if (!insn_is_any_branch)
3692 return This::STATUS_BAD_RELOC;
3694 else if (r_type == elfcpp::R_ARM_XPC25)
3696 // FIXME: AAELF document IH0044C does not say much about it other
3697 // than it being obsolete.
3698 if (!insn_is_any_branch)
3699 return This::STATUS_BAD_RELOC;
3704 // A branch to an undefined weak symbol is turned into a jump to
3705 // the next instruction unless a PLT entry will be created.
3706 // Do the same for local undefined symbols.
3707 // The jump to the next instruction is optimized as a NOP depending
3708 // on the architecture.
3709 const Target_arm<big_endian>* arm_target =
3710 Target_arm<big_endian>::default_target();
3711 if (is_weakly_undefined_without_plt)
3713 Valtype cond = val & 0xf0000000U;
3714 if (arm_target->may_use_arm_nop())
3715 val = cond | 0x0320f000;
3717 val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0.
3718 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3719 return This::STATUS_OKAY;
3722 Valtype addend = utils::sign_extend<26>(val << 2);
3723 Valtype branch_target = psymval->value(object, addend);
3724 int32_t branch_offset = branch_target - address;
3726 // We need a stub if the branch offset is too large or if we need
3728 bool may_use_blx = arm_target->may_use_blx();
3729 Reloc_stub* stub = NULL;
3730 if (utils::has_overflow<26>(branch_offset)
3731 || ((thumb_bit != 0) && !(may_use_blx && r_type == elfcpp::R_ARM_CALL)))
3733 Valtype unadjusted_branch_target = psymval->value(object, 0);
3735 Stub_type stub_type =
3736 Reloc_stub::stub_type_for_reloc(r_type, address,
3737 unadjusted_branch_target,
3739 if (stub_type != arm_stub_none)
3741 Stub_table<big_endian>* stub_table =
3742 object->stub_table(relinfo->data_shndx);
3743 gold_assert(stub_table != NULL);
3745 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3746 stub = stub_table->find_reloc_stub(stub_key);
3747 gold_assert(stub != NULL);
3748 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3749 branch_target = stub_table->address() + stub->offset() + addend;
3750 branch_offset = branch_target - address;
3751 gold_assert(!utils::has_overflow<26>(branch_offset));
3755 // At this point, if we still need to switch mode, the instruction
3756 // must either be a BLX or a BL that can be converted to a BLX.
3760 gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL);
3761 val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23);
3764 val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL);
3765 elfcpp::Swap<32, big_endian>::writeval(wv, val);
3766 return (utils::has_overflow<26>(branch_offset)
3767 ? This::STATUS_OVERFLOW : This::STATUS_OKAY);
3770 // Relocate THUMB long branches. This handles relocation types
3771 // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22.
3772 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3773 // undefined and we do not use PLT in this relocation. In such a case,
3774 // the branch is converted into an NOP.
3776 template<bool big_endian>
3777 typename Arm_relocate_functions<big_endian>::Status
3778 Arm_relocate_functions<big_endian>::thumb_branch_common(
3779 unsigned int r_type,
3780 const Relocate_info<32, big_endian>* relinfo,
3781 unsigned char *view,
3782 const Sized_symbol<32>* gsym,
3783 const Arm_relobj<big_endian>* object,
3785 const Symbol_value<32>* psymval,
3786 Arm_address address,
3787 Arm_address thumb_bit,
3788 bool is_weakly_undefined_without_plt)
3790 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3791 Valtype* wv = reinterpret_cast<Valtype*>(view);
3792 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3793 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3795 // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference
3797 bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U;
3798 bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U;
3800 // Check that the instruction is valid.
3801 if (r_type == elfcpp::R_ARM_THM_CALL)
3803 if (!is_bl_insn && !is_blx_insn)
3804 return This::STATUS_BAD_RELOC;
3806 else if (r_type == elfcpp::R_ARM_THM_JUMP24)
3808 // This cannot be a BLX.
3810 return This::STATUS_BAD_RELOC;
3812 else if (r_type == elfcpp::R_ARM_THM_XPC22)
3814 // Check for Thumb to Thumb call.
3816 return This::STATUS_BAD_RELOC;
3819 gold_warning(_("%s: Thumb BLX instruction targets "
3820 "thumb function '%s'."),
3821 object->name().c_str(),
3822 (gsym ? gsym->name() : "(local)"));
3823 // Convert BLX to BL.
3824 lower_insn |= 0x1000U;
3830 // A branch to an undefined weak symbol is turned into a jump to
3831 // the next instruction unless a PLT entry will be created.
3832 // The jump to the next instruction is optimized as a NOP.W for
3833 // Thumb-2 enabled architectures.
3834 const Target_arm<big_endian>* arm_target =
3835 Target_arm<big_endian>::default_target();
3836 if (is_weakly_undefined_without_plt)
3838 if (arm_target->may_use_thumb2_nop())
3840 elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af);
3841 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000);
3845 elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000);
3846 elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00);
3848 return This::STATUS_OKAY;
3851 int32_t addend = This::thumb32_branch_offset(upper_insn, lower_insn);
3852 Arm_address branch_target = psymval->value(object, addend);
3854 // For BLX, bit 1 of target address comes from bit 1 of base address.
3855 bool may_use_blx = arm_target->may_use_blx();
3856 if (thumb_bit == 0 && may_use_blx)
3857 branch_target = utils::bit_select(branch_target, address, 0x2);
3859 int32_t branch_offset = branch_target - address;
3861 // We need a stub if the branch offset is too large or if we need
3863 bool thumb2 = arm_target->using_thumb2();
3864 if ((!thumb2 && utils::has_overflow<23>(branch_offset))
3865 || (thumb2 && utils::has_overflow<25>(branch_offset))
3866 || ((thumb_bit == 0)
3867 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
3868 || r_type == elfcpp::R_ARM_THM_JUMP24)))
3870 Arm_address unadjusted_branch_target = psymval->value(object, 0);
3872 Stub_type stub_type =
3873 Reloc_stub::stub_type_for_reloc(r_type, address,
3874 unadjusted_branch_target,
3877 if (stub_type != arm_stub_none)
3879 Stub_table<big_endian>* stub_table =
3880 object->stub_table(relinfo->data_shndx);
3881 gold_assert(stub_table != NULL);
3883 Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend);
3884 Reloc_stub* stub = stub_table->find_reloc_stub(stub_key);
3885 gold_assert(stub != NULL);
3886 thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0;
3887 branch_target = stub_table->address() + stub->offset() + addend;
3888 if (thumb_bit == 0 && may_use_blx)
3889 branch_target = utils::bit_select(branch_target, address, 0x2);
3890 branch_offset = branch_target - address;
3894 // At this point, if we still need to switch mode, the instruction
3895 // must either be a BLX or a BL that can be converted to a BLX.
3898 gold_assert(may_use_blx
3899 && (r_type == elfcpp::R_ARM_THM_CALL
3900 || r_type == elfcpp::R_ARM_THM_XPC22));
3901 // Make sure this is a BLX.
3902 lower_insn &= ~0x1000U;
3906 // Make sure this is a BL.
3907 lower_insn |= 0x1000U;
3910 // For a BLX instruction, make sure that the relocation is rounded up
3911 // to a word boundary. This follows the semantics of the instruction
3912 // which specifies that bit 1 of the target address will come from bit
3913 // 1 of the base address.
3914 if ((lower_insn & 0x5000U) == 0x4000U)
3915 gold_assert((branch_offset & 3) == 0);
3917 // Put BRANCH_OFFSET back into the insn. Assumes two's complement.
3918 // We use the Thumb-2 encoding, which is safe even if dealing with
3919 // a Thumb-1 instruction by virtue of our overflow check above. */
3920 upper_insn = This::thumb32_branch_upper(upper_insn, branch_offset);
3921 lower_insn = This::thumb32_branch_lower(lower_insn, branch_offset);
3923 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
3924 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
3926 gold_assert(!utils::has_overflow<25>(branch_offset));
3929 ? utils::has_overflow<25>(branch_offset)
3930 : utils::has_overflow<23>(branch_offset))
3931 ? This::STATUS_OVERFLOW
3932 : This::STATUS_OKAY);
3935 // Relocate THUMB-2 long conditional branches.
3936 // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly
3937 // undefined and we do not use PLT in this relocation. In such a case,
3938 // the branch is converted into an NOP.
3940 template<bool big_endian>
3941 typename Arm_relocate_functions<big_endian>::Status
3942 Arm_relocate_functions<big_endian>::thm_jump19(
3943 unsigned char *view,
3944 const Arm_relobj<big_endian>* object,
3945 const Symbol_value<32>* psymval,
3946 Arm_address address,
3947 Arm_address thumb_bit)
3949 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
3950 Valtype* wv = reinterpret_cast<Valtype*>(view);
3951 uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
3952 uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
3953 int32_t addend = This::thumb32_cond_branch_offset(upper_insn, lower_insn);
3955 Arm_address branch_target = psymval->value(object, addend);
3956 int32_t branch_offset = branch_target - address;
3958 // ??? Should handle interworking? GCC might someday try to
3959 // use this for tail calls.
3960 // FIXME: We do support thumb entry to PLT yet.
3963 gold_error(_("conditional branch to PLT in THUMB-2 not supported yet."));
3964 return This::STATUS_BAD_RELOC;
3967 // Put RELOCATION back into the insn.
3968 upper_insn = This::thumb32_cond_branch_upper(upper_insn, branch_offset);
3969 lower_insn = This::thumb32_cond_branch_lower(lower_insn, branch_offset);
3971 // Put the relocated value back in the object file:
3972 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
3973 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
3975 return (utils::has_overflow<21>(branch_offset)
3976 ? This::STATUS_OVERFLOW
3977 : This::STATUS_OKAY);
3980 // Get the GOT section, creating it if necessary.
3982 template<bool big_endian>
3983 Arm_output_data_got<big_endian>*
3984 Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout)
3986 if (this->got_ == NULL)
3988 gold_assert(symtab != NULL && layout != NULL);
3990 this->got_ = new Arm_output_data_got<big_endian>(symtab, layout);
3993 os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
3995 | elfcpp::SHF_WRITE),
3996 this->got_, false, false, false,
3998 // The old GNU linker creates a .got.plt section. We just
3999 // create another set of data in the .got section. Note that we
4000 // always create a PLT if we create a GOT, although the PLT
4002 this->got_plt_ = new Output_data_space(4, "** GOT PLT");
4003 os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
4005 | elfcpp::SHF_WRITE),
4006 this->got_plt_, false, false,
4009 // The first three entries are reserved.
4010 this->got_plt_->set_current_data_size(3 * 4);
4012 // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
4013 symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
4014 Symbol_table::PREDEFINED,
4016 0, 0, elfcpp::STT_OBJECT,
4018 elfcpp::STV_HIDDEN, 0,
4024 // Get the dynamic reloc section, creating it if necessary.
4026 template<bool big_endian>
4027 typename Target_arm<big_endian>::Reloc_section*
4028 Target_arm<big_endian>::rel_dyn_section(Layout* layout)
4030 if (this->rel_dyn_ == NULL)
4032 gold_assert(layout != NULL);
4033 this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
4034 layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
4035 elfcpp::SHF_ALLOC, this->rel_dyn_, true,
4036 false, false, false);
4038 return this->rel_dyn_;
4041 // Insn_template methods.
4043 // Return byte size of an instruction template.
4046 Insn_template::size() const
4048 switch (this->type())
4051 case THUMB16_SPECIAL_TYPE:
4062 // Return alignment of an instruction template.
4065 Insn_template::alignment() const
4067 switch (this->type())
4070 case THUMB16_SPECIAL_TYPE:
4081 // Stub_template methods.
4083 Stub_template::Stub_template(
4084 Stub_type type, const Insn_template* insns,
4086 : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1),
4087 entry_in_thumb_mode_(false), relocs_()
4091 // Compute byte size and alignment of stub template.
4092 for (size_t i = 0; i < insn_count; i++)
4094 unsigned insn_alignment = insns[i].alignment();
4095 size_t insn_size = insns[i].size();
4096 gold_assert((offset & (insn_alignment - 1)) == 0);
4097 this->alignment_ = std::max(this->alignment_, insn_alignment);
4098 switch (insns[i].type())
4100 case Insn_template::THUMB16_TYPE:
4101 case Insn_template::THUMB16_SPECIAL_TYPE:
4103 this->entry_in_thumb_mode_ = true;
4106 case Insn_template::THUMB32_TYPE:
4107 if (insns[i].r_type() != elfcpp::R_ARM_NONE)
4108 this->relocs_.push_back(Reloc(i, offset));
4110 this->entry_in_thumb_mode_ = true;
4113 case Insn_template::ARM_TYPE:
4114 // Handle cases where the target is encoded within the
4116 if (insns[i].r_type() == elfcpp::R_ARM_JUMP24)
4117 this->relocs_.push_back(Reloc(i, offset));
4120 case Insn_template::DATA_TYPE:
4121 // Entry point cannot be data.
4122 gold_assert(i != 0);
4123 this->relocs_.push_back(Reloc(i, offset));
4129 offset += insn_size;
4131 this->size_ = offset;
4136 // Template to implement do_write for a specific target endianness.
4138 template<bool big_endian>
4140 Stub::do_fixed_endian_write(unsigned char* view, section_size_type view_size)
4142 const Stub_template* stub_template = this->stub_template();
4143 const Insn_template* insns = stub_template->insns();
4145 // FIXME: We do not handle BE8 encoding yet.
4146 unsigned char* pov = view;
4147 for (size_t i = 0; i < stub_template->insn_count(); i++)
4149 switch (insns[i].type())
4151 case Insn_template::THUMB16_TYPE:
4152 elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff);
4154 case Insn_template::THUMB16_SPECIAL_TYPE:
4155 elfcpp::Swap<16, big_endian>::writeval(
4157 this->thumb16_special(i));
4159 case Insn_template::THUMB32_TYPE:
4161 uint32_t hi = (insns[i].data() >> 16) & 0xffff;
4162 uint32_t lo = insns[i].data() & 0xffff;
4163 elfcpp::Swap<16, big_endian>::writeval(pov, hi);
4164 elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo);
4167 case Insn_template::ARM_TYPE:
4168 case Insn_template::DATA_TYPE:
4169 elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data());
4174 pov += insns[i].size();
4176 gold_assert(static_cast<section_size_type>(pov - view) == view_size);
4179 // Reloc_stub::Key methods.
4181 // Dump a Key as a string for debugging.
4184 Reloc_stub::Key::name() const
4186 if (this->r_sym_ == invalid_index)
4188 // Global symbol key name
4189 // <stub-type>:<symbol name>:<addend>.
4190 const std::string sym_name = this->u_.symbol->name();
4191 // We need to print two hex number and two colons. So just add 100 bytes
4192 // to the symbol name size.
4193 size_t len = sym_name.size() + 100;
4194 char* buffer = new char[len];
4195 int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_,
4196 sym_name.c_str(), this->addend_);
4197 gold_assert(c > 0 && c < static_cast<int>(len));
4199 return std::string(buffer);
4203 // local symbol key name
4204 // <stub-type>:<object>:<r_sym>:<addend>.
4205 const size_t len = 200;
4207 int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_,
4208 this->u_.relobj, this->r_sym_, this->addend_);
4209 gold_assert(c > 0 && c < static_cast<int>(len));
4210 return std::string(buffer);
4214 // Reloc_stub methods.
4216 // Determine the type of stub needed, if any, for a relocation of R_TYPE at
4217 // LOCATION to DESTINATION.
4218 // This code is based on the arm_type_of_stub function in
4219 // bfd/elf32-arm.c. We have changed the interface a liitle to keep the Stub
4223 Reloc_stub::stub_type_for_reloc(
4224 unsigned int r_type,
4225 Arm_address location,
4226 Arm_address destination,
4227 bool target_is_thumb)
4229 Stub_type stub_type = arm_stub_none;
4231 // This is a bit ugly but we want to avoid using a templated class for
4232 // big and little endianities.
4234 bool should_force_pic_veneer;
4237 if (parameters->target().is_big_endian())
4239 const Target_arm<true>* big_endian_target =
4240 Target_arm<true>::default_target();
4241 may_use_blx = big_endian_target->may_use_blx();
4242 should_force_pic_veneer = big_endian_target->should_force_pic_veneer();
4243 thumb2 = big_endian_target->using_thumb2();
4244 thumb_only = big_endian_target->using_thumb_only();
4248 const Target_arm<false>* little_endian_target =
4249 Target_arm<false>::default_target();
4250 may_use_blx = little_endian_target->may_use_blx();
4251 should_force_pic_veneer = little_endian_target->should_force_pic_veneer();
4252 thumb2 = little_endian_target->using_thumb2();
4253 thumb_only = little_endian_target->using_thumb_only();
4256 int64_t branch_offset;
4257 if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24)
4259 // For THUMB BLX instruction, bit 1 of target comes from bit 1 of the
4260 // base address (instruction address + 4).
4261 if ((r_type == elfcpp::R_ARM_THM_CALL) && may_use_blx && !target_is_thumb)
4262 destination = utils::bit_select(destination, location, 0x2);
4263 branch_offset = static_cast<int64_t>(destination) - location;
4265 // Handle cases where:
4266 // - this call goes too far (different Thumb/Thumb2 max
4268 // - it's a Thumb->Arm call and blx is not available, or it's a
4269 // Thumb->Arm branch (not bl). A stub is needed in this case.
4271 && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET
4272 || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET)))
4274 && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET
4275 || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET)))
4276 || ((!target_is_thumb)
4277 && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx)
4278 || (r_type == elfcpp::R_ARM_THM_JUMP24))))
4280 if (target_is_thumb)
4285 stub_type = (parameters->options().shared()
4286 || should_force_pic_veneer)
4289 && (r_type == elfcpp::R_ARM_THM_CALL))
4290 // V5T and above. Stub starts with ARM code, so
4291 // we must be able to switch mode before
4292 // reaching it, which is only possible for 'bl'
4293 // (ie R_ARM_THM_CALL relocation).
4294 ? arm_stub_long_branch_any_thumb_pic
4295 // On V4T, use Thumb code only.
4296 : arm_stub_long_branch_v4t_thumb_thumb_pic)
4300 && (r_type == elfcpp::R_ARM_THM_CALL))
4301 ? arm_stub_long_branch_any_any // V5T and above.
4302 : arm_stub_long_branch_v4t_thumb_thumb); // V4T.
4306 stub_type = (parameters->options().shared()
4307 || should_force_pic_veneer)
4308 ? arm_stub_long_branch_thumb_only_pic // PIC stub.
4309 : arm_stub_long_branch_thumb_only; // non-PIC stub.
4316 // FIXME: We should check that the input section is from an
4317 // object that has interwork enabled.
4319 stub_type = (parameters->options().shared()
4320 || should_force_pic_veneer)
4323 && (r_type == elfcpp::R_ARM_THM_CALL))
4324 ? arm_stub_long_branch_any_arm_pic // V5T and above.
4325 : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T.
4329 && (r_type == elfcpp::R_ARM_THM_CALL))
4330 ? arm_stub_long_branch_any_any // V5T and above.
4331 : arm_stub_long_branch_v4t_thumb_arm); // V4T.
4333 // Handle v4t short branches.
4334 if ((stub_type == arm_stub_long_branch_v4t_thumb_arm)
4335 && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET)
4336 && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET))
4337 stub_type = arm_stub_short_branch_v4t_thumb_arm;
4341 else if (r_type == elfcpp::R_ARM_CALL
4342 || r_type == elfcpp::R_ARM_JUMP24
4343 || r_type == elfcpp::R_ARM_PLT32)
4345 branch_offset = static_cast<int64_t>(destination) - location;
4346 if (target_is_thumb)
4350 // FIXME: We should check that the input section is from an
4351 // object that has interwork enabled.
4353 // We have an extra 2-bytes reach because of
4354 // the mode change (bit 24 (H) of BLX encoding).
4355 if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2)
4356 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)
4357 || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx)
4358 || (r_type == elfcpp::R_ARM_JUMP24)
4359 || (r_type == elfcpp::R_ARM_PLT32))
4361 stub_type = (parameters->options().shared()
4362 || should_force_pic_veneer)
4365 ? arm_stub_long_branch_any_thumb_pic// V5T and above.
4366 : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub.
4370 ? arm_stub_long_branch_any_any // V5T and above.
4371 : arm_stub_long_branch_v4t_arm_thumb); // V4T.
4377 if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET
4378 || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET))
4380 stub_type = (parameters->options().shared()
4381 || should_force_pic_veneer)
4382 ? arm_stub_long_branch_any_arm_pic // PIC stubs.
4383 : arm_stub_long_branch_any_any; /// non-PIC.
4391 // Cortex_a8_stub methods.
4393 // Return the instruction for a THUMB16_SPECIAL_TYPE instruction template.
4394 // I is the position of the instruction template in the stub template.
4397 Cortex_a8_stub::do_thumb16_special(size_t i)
4399 // The only use of this is to copy condition code from a conditional
4400 // branch being worked around to the corresponding conditional branch in
4402 gold_assert(this->stub_template()->type() == arm_stub_a8_veneer_b_cond
4404 uint16_t data = this->stub_template()->insns()[i].data();
4405 gold_assert((data & 0xff00U) == 0xd000U);
4406 data |= ((this->original_insn_ >> 22) & 0xf) << 8;
4410 // Stub_factory methods.
4412 Stub_factory::Stub_factory()
4414 // The instruction template sequences are declared as static
4415 // objects and initialized first time the constructor runs.
4417 // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx
4418 // to reach the stub if necessary.
4419 static const Insn_template elf32_arm_stub_long_branch_any_any[] =
4421 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4422 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4423 // dcd R_ARM_ABS32(X)
4426 // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not
4428 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] =
4430 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4431 Insn_template::arm_insn(0xe12fff1c), // bx ip
4432 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4433 // dcd R_ARM_ABS32(X)
4436 // Thumb -> Thumb long branch stub. Used on M-profile architectures.
4437 static const Insn_template elf32_arm_stub_long_branch_thumb_only[] =
4439 Insn_template::thumb16_insn(0xb401), // push {r0}
4440 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4441 Insn_template::thumb16_insn(0x4684), // mov ip, r0
4442 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4443 Insn_template::thumb16_insn(0x4760), // bx ip
4444 Insn_template::thumb16_insn(0xbf00), // nop
4445 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4446 // dcd R_ARM_ABS32(X)
4449 // V4T Thumb -> Thumb long branch stub. Using the stack is not
4451 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] =
4453 Insn_template::thumb16_insn(0x4778), // bx pc
4454 Insn_template::thumb16_insn(0x46c0), // nop
4455 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4456 Insn_template::arm_insn(0xe12fff1c), // bx ip
4457 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4458 // dcd R_ARM_ABS32(X)
4461 // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not
4463 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] =
4465 Insn_template::thumb16_insn(0x4778), // bx pc
4466 Insn_template::thumb16_insn(0x46c0), // nop
4467 Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4]
4468 Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0),
4469 // dcd R_ARM_ABS32(X)
4472 // V4T Thumb -> ARM short branch stub. Shorter variant of the above
4473 // one, when the destination is close enough.
4474 static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] =
4476 Insn_template::thumb16_insn(0x4778), // bx pc
4477 Insn_template::thumb16_insn(0x46c0), // nop
4478 Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8)
4481 // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use
4482 // blx to reach the stub if necessary.
4483 static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] =
4485 Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc]
4486 Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip
4487 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4488 // dcd R_ARM_REL32(X-4)
4491 // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use
4492 // blx to reach the stub if necessary. We can not add into pc;
4493 // it is not guaranteed to mode switch (different in ARMv6 and
4495 static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] =
4497 Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4]
4498 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4499 Insn_template::arm_insn(0xe12fff1c), // bx ip
4500 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4501 // dcd R_ARM_REL32(X)
4504 // V4T ARM -> ARM long branch stub, PIC.
4505 static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] =
4507 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4508 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4509 Insn_template::arm_insn(0xe12fff1c), // bx ip
4510 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4511 // dcd R_ARM_REL32(X)
4514 // V4T Thumb -> ARM long branch stub, PIC.
4515 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] =
4517 Insn_template::thumb16_insn(0x4778), // bx pc
4518 Insn_template::thumb16_insn(0x46c0), // nop
4519 Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0]
4520 Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc
4521 Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4),
4522 // dcd R_ARM_REL32(X)
4525 // Thumb -> Thumb long branch stub, PIC. Used on M-profile
4527 static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] =
4529 Insn_template::thumb16_insn(0xb401), // push {r0}
4530 Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8]
4531 Insn_template::thumb16_insn(0x46fc), // mov ip, pc
4532 Insn_template::thumb16_insn(0x4484), // add ip, r0
4533 Insn_template::thumb16_insn(0xbc01), // pop {r0}
4534 Insn_template::thumb16_insn(0x4760), // bx ip
4535 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4),
4536 // dcd R_ARM_REL32(X)
4539 // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not
4541 static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] =
4543 Insn_template::thumb16_insn(0x4778), // bx pc
4544 Insn_template::thumb16_insn(0x46c0), // nop
4545 Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4]
4546 Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip
4547 Insn_template::arm_insn(0xe12fff1c), // bx ip
4548 Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0),
4549 // dcd R_ARM_REL32(X)
4552 // Cortex-A8 erratum-workaround stubs.
4554 // Stub used for conditional branches (which may be beyond +/-1MB away,
4555 // so we can't use a conditional branch to reach this stub).
4562 static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] =
4564 Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true
4565 Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after
4566 Insn_template::thumb32_b_insn(0xf000b800, -4) // true:
4570 // Stub used for b.w and bl.w instructions.
4572 static const Insn_template elf32_arm_stub_a8_veneer_b[] =
4574 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4577 static const Insn_template elf32_arm_stub_a8_veneer_bl[] =
4579 Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest
4582 // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w
4583 // instruction (which switches to ARM mode) to point to this stub. Jump to
4584 // the real destination using an ARM-mode branch.
4585 static const Insn_template elf32_arm_stub_a8_veneer_blx[] =
4587 Insn_template::arm_rel_insn(0xea000000, -8) // b dest
4590 // Stub used to provide an interworking for R_ARM_V4BX relocation
4591 // (bx r[n] instruction).
4592 static const Insn_template elf32_arm_stub_v4_veneer_bx[] =
4594 Insn_template::arm_insn(0xe3100001), // tst r<n>, #1
4595 Insn_template::arm_insn(0x01a0f000), // moveq pc, r<n>
4596 Insn_template::arm_insn(0xe12fff10) // bx r<n>
4599 // Fill in the stub template look-up table. Stub templates are constructed
4600 // per instance of Stub_factory for fast look-up without locking
4601 // in a thread-enabled environment.
4603 this->stub_templates_[arm_stub_none] =
4604 new Stub_template(arm_stub_none, NULL, 0);
4606 #define DEF_STUB(x) \
4610 = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \
4611 Stub_type type = arm_stub_##x; \
4612 this->stub_templates_[type] = \
4613 new Stub_template(type, elf32_arm_stub_##x, array_size); \
4621 // Stub_table methods.
4623 // Removel all Cortex-A8 stub.
4625 template<bool big_endian>
4627 Stub_table<big_endian>::remove_all_cortex_a8_stubs()
4629 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4630 p != this->cortex_a8_stubs_.end();
4633 this->cortex_a8_stubs_.clear();
4636 // Relocate one stub. This is a helper for Stub_table::relocate_stubs().
4638 template<bool big_endian>
4640 Stub_table<big_endian>::relocate_stub(
4642 const Relocate_info<32, big_endian>* relinfo,
4643 Target_arm<big_endian>* arm_target,
4644 Output_section* output_section,
4645 unsigned char* view,
4646 Arm_address address,
4647 section_size_type view_size)
4649 const Stub_template* stub_template = stub->stub_template();
4650 if (stub_template->reloc_count() != 0)
4652 // Adjust view to cover the stub only.
4653 section_size_type offset = stub->offset();
4654 section_size_type stub_size = stub_template->size();
4655 gold_assert(offset + stub_size <= view_size);
4657 arm_target->relocate_stub(stub, relinfo, output_section, view + offset,
4658 address + offset, stub_size);
4662 // Relocate all stubs in this stub table.
4664 template<bool big_endian>
4666 Stub_table<big_endian>::relocate_stubs(
4667 const Relocate_info<32, big_endian>* relinfo,
4668 Target_arm<big_endian>* arm_target,
4669 Output_section* output_section,
4670 unsigned char* view,
4671 Arm_address address,
4672 section_size_type view_size)
4674 // If we are passed a view bigger than the stub table's. we need to
4676 gold_assert(address == this->address()
4678 == static_cast<section_size_type>(this->data_size())));
4680 // Relocate all relocation stubs.
4681 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4682 p != this->reloc_stubs_.end();
4684 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4685 address, view_size);
4687 // Relocate all Cortex-A8 stubs.
4688 for (Cortex_a8_stub_list::iterator p = this->cortex_a8_stubs_.begin();
4689 p != this->cortex_a8_stubs_.end();
4691 this->relocate_stub(p->second, relinfo, arm_target, output_section, view,
4692 address, view_size);
4694 // Relocate all ARM V4BX stubs.
4695 for (Arm_v4bx_stub_list::iterator p = this->arm_v4bx_stubs_.begin();
4696 p != this->arm_v4bx_stubs_.end();
4700 this->relocate_stub(*p, relinfo, arm_target, output_section, view,
4701 address, view_size);
4705 // Write out the stubs to file.
4707 template<bool big_endian>
4709 Stub_table<big_endian>::do_write(Output_file* of)
4711 off_t offset = this->offset();
4712 const section_size_type oview_size =
4713 convert_to_section_size_type(this->data_size());
4714 unsigned char* const oview = of->get_output_view(offset, oview_size);
4716 // Write relocation stubs.
4717 for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin();
4718 p != this->reloc_stubs_.end();
4721 Reloc_stub* stub = p->second;
4722 Arm_address address = this->address() + stub->offset();
4724 == align_address(address,
4725 stub->stub_template()->alignment()));
4726 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4730 // Write Cortex-A8 stubs.
4731 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4732 p != this->cortex_a8_stubs_.end();
4735 Cortex_a8_stub* stub = p->second;
4736 Arm_address address = this->address() + stub->offset();
4738 == align_address(address,
4739 stub->stub_template()->alignment()));
4740 stub->write(oview + stub->offset(), stub->stub_template()->size(),
4744 // Write ARM V4BX relocation stubs.
4745 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4746 p != this->arm_v4bx_stubs_.end();
4752 Arm_address address = this->address() + (*p)->offset();
4754 == align_address(address,
4755 (*p)->stub_template()->alignment()));
4756 (*p)->write(oview + (*p)->offset(), (*p)->stub_template()->size(),
4760 of->write_output_view(this->offset(), oview_size, oview);
4763 // Update the data size and address alignment of the stub table at the end
4764 // of a relaxation pass. Return true if either the data size or the
4765 // alignment changed in this relaxation pass.
4767 template<bool big_endian>
4769 Stub_table<big_endian>::update_data_size_and_addralign()
4771 // Go over all stubs in table to compute data size and address alignment.
4772 off_t size = this->reloc_stubs_size_;
4773 unsigned addralign = this->reloc_stubs_addralign_;
4775 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4776 p != this->cortex_a8_stubs_.end();
4779 const Stub_template* stub_template = p->second->stub_template();
4780 addralign = std::max(addralign, stub_template->alignment());
4781 size = (align_address(size, stub_template->alignment())
4782 + stub_template->size());
4785 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4786 p != this->arm_v4bx_stubs_.end();
4792 const Stub_template* stub_template = (*p)->stub_template();
4793 addralign = std::max(addralign, stub_template->alignment());
4794 size = (align_address(size, stub_template->alignment())
4795 + stub_template->size());
4798 // Check if either data size or alignment changed in this pass.
4799 // Update prev_data_size_ and prev_addralign_. These will be used
4800 // as the current data size and address alignment for the next pass.
4801 bool changed = size != this->prev_data_size_;
4802 this->prev_data_size_ = size;
4804 if (addralign != this->prev_addralign_)
4806 this->prev_addralign_ = addralign;
4811 // Finalize the stubs. This sets the offsets of the stubs within the stub
4812 // table. It also marks all input sections needing Cortex-A8 workaround.
4814 template<bool big_endian>
4816 Stub_table<big_endian>::finalize_stubs()
4818 off_t off = this->reloc_stubs_size_;
4819 for (Cortex_a8_stub_list::const_iterator p = this->cortex_a8_stubs_.begin();
4820 p != this->cortex_a8_stubs_.end();
4823 Cortex_a8_stub* stub = p->second;
4824 const Stub_template* stub_template = stub->stub_template();
4825 uint64_t stub_addralign = stub_template->alignment();
4826 off = align_address(off, stub_addralign);
4827 stub->set_offset(off);
4828 off += stub_template->size();
4830 // Mark input section so that we can determine later if a code section
4831 // needs the Cortex-A8 workaround quickly.
4832 Arm_relobj<big_endian>* arm_relobj =
4833 Arm_relobj<big_endian>::as_arm_relobj(stub->relobj());
4834 arm_relobj->mark_section_for_cortex_a8_workaround(stub->shndx());
4837 for (Arm_v4bx_stub_list::const_iterator p = this->arm_v4bx_stubs_.begin();
4838 p != this->arm_v4bx_stubs_.end();
4844 const Stub_template* stub_template = (*p)->stub_template();
4845 uint64_t stub_addralign = stub_template->alignment();
4846 off = align_address(off, stub_addralign);
4847 (*p)->set_offset(off);
4848 off += stub_template->size();
4851 gold_assert(off <= this->prev_data_size_);
4854 // Apply Cortex-A8 workaround to an address range between VIEW_ADDRESS
4855 // and VIEW_ADDRESS + VIEW_SIZE - 1. VIEW points to the mapped address
4856 // of the address range seen by the linker.
4858 template<bool big_endian>
4860 Stub_table<big_endian>::apply_cortex_a8_workaround_to_address_range(
4861 Target_arm<big_endian>* arm_target,
4862 unsigned char* view,
4863 Arm_address view_address,
4864 section_size_type view_size)
4866 // Cortex-A8 stubs are sorted by addresses of branches being fixed up.
4867 for (Cortex_a8_stub_list::const_iterator p =
4868 this->cortex_a8_stubs_.lower_bound(view_address);
4869 ((p != this->cortex_a8_stubs_.end())
4870 && (p->first < (view_address + view_size)));
4873 // We do not store the THUMB bit in the LSB of either the branch address
4874 // or the stub offset. There is no need to strip the LSB.
4875 Arm_address branch_address = p->first;
4876 const Cortex_a8_stub* stub = p->second;
4877 Arm_address stub_address = this->address() + stub->offset();
4879 // Offset of the branch instruction relative to this view.
4880 section_size_type offset =
4881 convert_to_section_size_type(branch_address - view_address);
4882 gold_assert((offset + 4) <= view_size);
4884 arm_target->apply_cortex_a8_workaround(stub, stub_address,
4885 view + offset, branch_address);
4889 // Arm_input_section methods.
4891 // Initialize an Arm_input_section.
4893 template<bool big_endian>
4895 Arm_input_section<big_endian>::init()
4897 Relobj* relobj = this->relobj();
4898 unsigned int shndx = this->shndx();
4900 // Cache these to speed up size and alignment queries. It is too slow
4901 // to call section_addraglin and section_size every time.
4902 this->original_addralign_ = relobj->section_addralign(shndx);
4903 this->original_size_ = relobj->section_size(shndx);
4905 // We want to make this look like the original input section after
4906 // output sections are finalized.
4907 Output_section* os = relobj->output_section(shndx);
4908 off_t offset = relobj->output_section_offset(shndx);
4909 gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx));
4910 this->set_address(os->address() + offset);
4911 this->set_file_offset(os->offset() + offset);
4913 this->set_current_data_size(this->original_size_);
4914 this->finalize_data_size();
4917 template<bool big_endian>
4919 Arm_input_section<big_endian>::do_write(Output_file* of)
4921 // We have to write out the original section content.
4922 section_size_type section_size;
4923 const unsigned char* section_contents =
4924 this->relobj()->section_contents(this->shndx(), §ion_size, false);
4925 of->write(this->offset(), section_contents, section_size);
4927 // If this owns a stub table and it is not empty, write it.
4928 if (this->is_stub_table_owner() && !this->stub_table_->empty())
4929 this->stub_table_->write(of);
4932 // Finalize data size.
4934 template<bool big_endian>
4936 Arm_input_section<big_endian>::set_final_data_size()
4938 // If this owns a stub table, finalize its data size as well.
4939 if (this->is_stub_table_owner())
4941 uint64_t address = this->address();
4943 // The stub table comes after the original section contents.
4944 address += this->original_size_;
4945 address = align_address(address, this->stub_table_->addralign());
4946 off_t offset = this->offset() + (address - this->address());
4947 this->stub_table_->set_address_and_file_offset(address, offset);
4948 address += this->stub_table_->data_size();
4949 gold_assert(address == this->address() + this->current_data_size());
4952 this->set_data_size(this->current_data_size());
4955 // Reset address and file offset.
4957 template<bool big_endian>
4959 Arm_input_section<big_endian>::do_reset_address_and_file_offset()
4961 // Size of the original input section contents.
4962 off_t off = convert_types<off_t, uint64_t>(this->original_size_);
4964 // If this is a stub table owner, account for the stub table size.
4965 if (this->is_stub_table_owner())
4967 Stub_table<big_endian>* stub_table = this->stub_table_;
4969 // Reset the stub table's address and file offset. The
4970 // current data size for child will be updated after that.
4971 stub_table_->reset_address_and_file_offset();
4972 off = align_address(off, stub_table_->addralign());
4973 off += stub_table->current_data_size();
4976 this->set_current_data_size(off);
4979 // Arm_exidx_cantunwind methods.
4981 // Write this to Output file OF for a fixed endianness.
4983 template<bool big_endian>
4985 Arm_exidx_cantunwind::do_fixed_endian_write(Output_file* of)
4987 off_t offset = this->offset();
4988 const section_size_type oview_size = 8;
4989 unsigned char* const oview = of->get_output_view(offset, oview_size);
4991 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
4992 Valtype* wv = reinterpret_cast<Valtype*>(oview);
4994 Output_section* os = this->relobj_->output_section(this->shndx_);
4995 gold_assert(os != NULL);
4997 Arm_relobj<big_endian>* arm_relobj =
4998 Arm_relobj<big_endian>::as_arm_relobj(this->relobj_);
4999 Arm_address output_offset =
5000 arm_relobj->get_output_section_offset(this->shndx_);
5001 Arm_address section_start;
5002 if (output_offset != Arm_relobj<big_endian>::invalid_address)
5003 section_start = os->address() + output_offset;
5006 // Currently this only happens for a relaxed section.
5007 const Output_relaxed_input_section* poris =
5008 os->find_relaxed_input_section(this->relobj_, this->shndx_);
5009 gold_assert(poris != NULL);
5010 section_start = poris->address();
5013 // We always append this to the end of an EXIDX section.
5014 Arm_address output_address =
5015 section_start + this->relobj_->section_size(this->shndx_);
5017 // Write out the entry. The first word either points to the beginning
5018 // or after the end of a text section. The second word is the special
5019 // EXIDX_CANTUNWIND value.
5020 uint32_t prel31_offset = output_address - this->address();
5021 if (utils::has_overflow<31>(offset))
5022 gold_error(_("PREL31 overflow in EXIDX_CANTUNWIND entry"));
5023 elfcpp::Swap<32, big_endian>::writeval(wv, prel31_offset & 0x7fffffffU);
5024 elfcpp::Swap<32, big_endian>::writeval(wv + 1, elfcpp::EXIDX_CANTUNWIND);
5026 of->write_output_view(this->offset(), oview_size, oview);
5029 // Arm_exidx_merged_section methods.
5031 // Constructor for Arm_exidx_merged_section.
5032 // EXIDX_INPUT_SECTION points to the unmodified EXIDX input section.
5033 // SECTION_OFFSET_MAP points to a section offset map describing how
5034 // parts of the input section are mapped to output. DELETED_BYTES is
5035 // the number of bytes deleted from the EXIDX input section.
5037 Arm_exidx_merged_section::Arm_exidx_merged_section(
5038 const Arm_exidx_input_section& exidx_input_section,
5039 const Arm_exidx_section_offset_map& section_offset_map,
5040 uint32_t deleted_bytes)
5041 : Output_relaxed_input_section(exidx_input_section.relobj(),
5042 exidx_input_section.shndx(),
5043 exidx_input_section.addralign()),
5044 exidx_input_section_(exidx_input_section),
5045 section_offset_map_(section_offset_map)
5047 // Fix size here so that we do not need to implement set_final_data_size.
5048 this->set_data_size(exidx_input_section.size() - deleted_bytes);
5049 this->fix_data_size();
5052 // Given an input OBJECT, an input section index SHNDX within that
5053 // object, and an OFFSET relative to the start of that input
5054 // section, return whether or not the corresponding offset within
5055 // the output section is known. If this function returns true, it
5056 // sets *POUTPUT to the output offset. The value -1 indicates that
5057 // this input offset is being discarded.
5060 Arm_exidx_merged_section::do_output_offset(
5061 const Relobj* relobj,
5063 section_offset_type offset,
5064 section_offset_type* poutput) const
5066 // We only handle offsets for the original EXIDX input section.
5067 if (relobj != this->exidx_input_section_.relobj()
5068 || shndx != this->exidx_input_section_.shndx())
5071 section_offset_type section_size =
5072 convert_types<section_offset_type>(this->exidx_input_section_.size());
5073 if (offset < 0 || offset >= section_size)
5074 // Input offset is out of valid range.
5078 // We need to look up the section offset map to determine the output
5079 // offset. Find the reference point in map that is first offset
5080 // bigger than or equal to this offset.
5081 Arm_exidx_section_offset_map::const_iterator p =
5082 this->section_offset_map_.lower_bound(offset);
5084 // The section offset maps are build such that this should not happen if
5085 // input offset is in the valid range.
5086 gold_assert(p != this->section_offset_map_.end());
5088 // We need to check if this is dropped.
5089 section_offset_type ref = p->first;
5090 section_offset_type mapped_ref = p->second;
5092 if (mapped_ref != Arm_exidx_input_section::invalid_offset)
5093 // Offset is present in output.
5094 *poutput = mapped_ref + (offset - ref);
5096 // Offset is discarded owing to EXIDX entry merging.
5103 // Write this to output file OF.
5106 Arm_exidx_merged_section::do_write(Output_file* of)
5108 // If we retain or discard the whole EXIDX input section, we would
5110 gold_assert(this->data_size() != this->exidx_input_section_.size()
5111 && this->data_size() != 0);
5113 off_t offset = this->offset();
5114 const section_size_type oview_size = this->data_size();
5115 unsigned char* const oview = of->get_output_view(offset, oview_size);
5117 Output_section* os = this->relobj()->output_section(this->shndx());
5118 gold_assert(os != NULL);
5120 // Get contents of EXIDX input section.
5121 section_size_type section_size;
5122 const unsigned char* section_contents =
5123 this->relobj()->section_contents(this->shndx(), §ion_size, false);
5124 gold_assert(section_size == this->exidx_input_section_.size());
5126 // Go over spans of input offsets and write only those that are not
5128 section_offset_type in_start = 0;
5129 section_offset_type out_start = 0;
5130 for(Arm_exidx_section_offset_map::const_iterator p =
5131 this->section_offset_map_.begin();
5132 p != this->section_offset_map_.end();
5135 section_offset_type in_end = p->first;
5136 gold_assert(in_end >= in_start);
5137 section_offset_type out_end = p->second;
5138 size_t in_chunk_size = convert_types<size_t>(in_end - in_start + 1);
5141 size_t out_chunk_size =
5142 convert_types<size_t>(out_end - out_start + 1);
5143 gold_assert(out_chunk_size == in_chunk_size);
5144 memcpy(oview + out_start, section_contents + in_start,
5146 out_start += out_chunk_size;
5148 in_start += in_chunk_size;
5151 gold_assert(convert_to_section_size_type(out_start) == oview_size);
5152 of->write_output_view(this->offset(), oview_size, oview);
5155 // Arm_exidx_fixup methods.
5157 // Append an EXIDX_CANTUNWIND in the current output section if the last entry
5158 // is not an EXIDX_CANTUNWIND entry already. The new EXIDX_CANTUNWIND entry
5159 // points to the end of the last seen EXIDX section.
5162 Arm_exidx_fixup::add_exidx_cantunwind_as_needed()
5164 if (this->last_unwind_type_ != UT_EXIDX_CANTUNWIND
5165 && this->last_input_section_ != NULL)
5167 Relobj* relobj = this->last_input_section_->relobj();
5168 unsigned int text_shndx = this->last_input_section_->link();
5169 Arm_exidx_cantunwind* cantunwind =
5170 new Arm_exidx_cantunwind(relobj, text_shndx);
5171 this->exidx_output_section_->add_output_section_data(cantunwind);
5172 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5176 // Process an EXIDX section entry in input. Return whether this entry
5177 // can be deleted in the output. SECOND_WORD in the second word of the
5181 Arm_exidx_fixup::process_exidx_entry(uint32_t second_word)
5184 if (second_word == elfcpp::EXIDX_CANTUNWIND)
5186 // Merge if previous entry is also an EXIDX_CANTUNWIND.
5187 delete_entry = this->last_unwind_type_ == UT_EXIDX_CANTUNWIND;
5188 this->last_unwind_type_ = UT_EXIDX_CANTUNWIND;
5190 else if ((second_word & 0x80000000) != 0)
5192 // Inlined unwinding data. Merge if equal to previous.
5193 delete_entry = (this->last_unwind_type_ == UT_INLINED_ENTRY
5194 && this->last_inlined_entry_ == second_word);
5195 this->last_unwind_type_ = UT_INLINED_ENTRY;
5196 this->last_inlined_entry_ = second_word;
5200 // Normal table entry. In theory we could merge these too,
5201 // but duplicate entries are likely to be much less common.
5202 delete_entry = false;
5203 this->last_unwind_type_ = UT_NORMAL_ENTRY;
5205 return delete_entry;
5208 // Update the current section offset map during EXIDX section fix-up.
5209 // If there is no map, create one. INPUT_OFFSET is the offset of a
5210 // reference point, DELETED_BYTES is the number of deleted by in the
5211 // section so far. If DELETE_ENTRY is true, the reference point and
5212 // all offsets after the previous reference point are discarded.
5215 Arm_exidx_fixup::update_offset_map(
5216 section_offset_type input_offset,
5217 section_size_type deleted_bytes,
5220 if (this->section_offset_map_ == NULL)
5221 this->section_offset_map_ = new Arm_exidx_section_offset_map();
5222 section_offset_type output_offset;
5224 output_offset = Arm_exidx_input_section::invalid_offset;
5226 output_offset = input_offset - deleted_bytes;
5227 (*this->section_offset_map_)[input_offset] = output_offset;
5230 // Process EXIDX_INPUT_SECTION for EXIDX entry merging. Return the number of
5231 // bytes deleted. If some entries are merged, also store a pointer to a newly
5232 // created Arm_exidx_section_offset_map object in *PSECTION_OFFSET_MAP. The
5233 // caller owns the map and is responsible for releasing it after use.
5235 template<bool big_endian>
5237 Arm_exidx_fixup::process_exidx_section(
5238 const Arm_exidx_input_section* exidx_input_section,
5239 Arm_exidx_section_offset_map** psection_offset_map)
5241 Relobj* relobj = exidx_input_section->relobj();
5242 unsigned shndx = exidx_input_section->shndx();
5243 section_size_type section_size;
5244 const unsigned char* section_contents =
5245 relobj->section_contents(shndx, §ion_size, false);
5247 if ((section_size % 8) != 0)
5249 // Something is wrong with this section. Better not touch it.
5250 gold_error(_("uneven .ARM.exidx section size in %s section %u"),
5251 relobj->name().c_str(), shndx);
5252 this->last_input_section_ = exidx_input_section;
5253 this->last_unwind_type_ = UT_NONE;
5257 uint32_t deleted_bytes = 0;
5258 bool prev_delete_entry = false;
5259 gold_assert(this->section_offset_map_ == NULL);
5261 for (section_size_type i = 0; i < section_size; i += 8)
5263 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
5265 reinterpret_cast<const Valtype*>(section_contents + i + 4);
5266 uint32_t second_word = elfcpp::Swap<32, big_endian>::readval(wv);
5268 bool delete_entry = this->process_exidx_entry(second_word);
5270 // Entry deletion causes changes in output offsets. We use a std::map
5271 // to record these. And entry (x, y) means input offset x
5272 // is mapped to output offset y. If y is invalid_offset, then x is
5273 // dropped in the output. Because of the way std::map::lower_bound
5274 // works, we record the last offset in a region w.r.t to keeping or
5275 // dropping. If there is no entry (x0, y0) for an input offset x0,
5276 // the output offset y0 of it is determined by the output offset y1 of
5277 // the smallest input offset x1 > x0 that there is an (x1, y1) entry
5278 // in the map. If y1 is not -1, then y0 = y1 + x0 - x1. Othewise, y1
5280 if (delete_entry != prev_delete_entry && i != 0)
5281 this->update_offset_map(i - 1, deleted_bytes, prev_delete_entry);
5283 // Update total deleted bytes for this entry.
5287 prev_delete_entry = delete_entry;
5290 // If section offset map is not NULL, make an entry for the end of
5292 if (this->section_offset_map_ != NULL)
5293 update_offset_map(section_size - 1, deleted_bytes, prev_delete_entry);
5295 *psection_offset_map = this->section_offset_map_;
5296 this->section_offset_map_ = NULL;
5297 this->last_input_section_ = exidx_input_section;
5299 // Set the first output text section so that we can link the EXIDX output
5300 // section to it. Ignore any EXIDX input section that is completely merged.
5301 if (this->first_output_text_section_ == NULL
5302 && deleted_bytes != section_size)
5304 unsigned int link = exidx_input_section->link();
5305 Output_section* os = relobj->output_section(link);
5306 gold_assert(os != NULL);
5307 this->first_output_text_section_ = os;
5310 return deleted_bytes;
5313 // Arm_output_section methods.
5315 // Create a stub group for input sections from BEGIN to END. OWNER
5316 // points to the input section to be the owner a new stub table.
5318 template<bool big_endian>
5320 Arm_output_section<big_endian>::create_stub_group(
5321 Input_section_list::const_iterator begin,
5322 Input_section_list::const_iterator end,
5323 Input_section_list::const_iterator owner,
5324 Target_arm<big_endian>* target,
5325 std::vector<Output_relaxed_input_section*>* new_relaxed_sections)
5327 // We use a different kind of relaxed section in an EXIDX section.
5328 // The static casting from Output_relaxed_input_section to
5329 // Arm_input_section is invalid in an EXIDX section. We are okay
5330 // because we should not be calling this for an EXIDX section.
5331 gold_assert(this->type() != elfcpp::SHT_ARM_EXIDX);
5333 // Currently we convert ordinary input sections into relaxed sections only
5334 // at this point but we may want to support creating relaxed input section
5335 // very early. So we check here to see if owner is already a relaxed
5338 Arm_input_section<big_endian>* arm_input_section;
5339 if (owner->is_relaxed_input_section())
5342 Arm_input_section<big_endian>::as_arm_input_section(
5343 owner->relaxed_input_section());
5347 gold_assert(owner->is_input_section());
5348 // Create a new relaxed input section.
5350 target->new_arm_input_section(owner->relobj(), owner->shndx());
5351 new_relaxed_sections->push_back(arm_input_section);
5354 // Create a stub table.
5355 Stub_table<big_endian>* stub_table =
5356 target->new_stub_table(arm_input_section);
5358 arm_input_section->set_stub_table(stub_table);
5360 Input_section_list::const_iterator p = begin;
5361 Input_section_list::const_iterator prev_p;
5363 // Look for input sections or relaxed input sections in [begin ... end].
5366 if (p->is_input_section() || p->is_relaxed_input_section())
5368 // The stub table information for input sections live
5369 // in their objects.
5370 Arm_relobj<big_endian>* arm_relobj =
5371 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5372 arm_relobj->set_stub_table(p->shndx(), stub_table);
5376 while (prev_p != end);
5379 // Group input sections for stub generation. GROUP_SIZE is roughly the limit
5380 // of stub groups. We grow a stub group by adding input section until the
5381 // size is just below GROUP_SIZE. The last input section will be converted
5382 // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add
5383 // input section after the stub table, effectively double the group size.
5385 // This is similar to the group_sections() function in elf32-arm.c but is
5386 // implemented differently.
5388 template<bool big_endian>
5390 Arm_output_section<big_endian>::group_sections(
5391 section_size_type group_size,
5392 bool stubs_always_after_branch,
5393 Target_arm<big_endian>* target)
5395 // We only care about sections containing code.
5396 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5399 // States for grouping.
5402 // No group is being built.
5404 // A group is being built but the stub table is not found yet.
5405 // We keep group a stub group until the size is just under GROUP_SIZE.
5406 // The last input section in the group will be used as the stub table.
5407 FINDING_STUB_SECTION,
5408 // A group is being built and we have already found a stub table.
5409 // We enter this state to grow a stub group by adding input section
5410 // after the stub table. This effectively doubles the group size.
5414 // Any newly created relaxed sections are stored here.
5415 std::vector<Output_relaxed_input_section*> new_relaxed_sections;
5417 State state = NO_GROUP;
5418 section_size_type off = 0;
5419 section_size_type group_begin_offset = 0;
5420 section_size_type group_end_offset = 0;
5421 section_size_type stub_table_end_offset = 0;
5422 Input_section_list::const_iterator group_begin =
5423 this->input_sections().end();
5424 Input_section_list::const_iterator stub_table =
5425 this->input_sections().end();
5426 Input_section_list::const_iterator group_end = this->input_sections().end();
5427 for (Input_section_list::const_iterator p = this->input_sections().begin();
5428 p != this->input_sections().end();
5431 section_size_type section_begin_offset =
5432 align_address(off, p->addralign());
5433 section_size_type section_end_offset =
5434 section_begin_offset + p->data_size();
5436 // Check to see if we should group the previously seens sections.
5442 case FINDING_STUB_SECTION:
5443 // Adding this section makes the group larger than GROUP_SIZE.
5444 if (section_end_offset - group_begin_offset >= group_size)
5446 if (stubs_always_after_branch)
5448 gold_assert(group_end != this->input_sections().end());
5449 this->create_stub_group(group_begin, group_end, group_end,
5450 target, &new_relaxed_sections);
5455 // But wait, there's more! Input sections up to
5456 // stub_group_size bytes after the stub table can be
5457 // handled by it too.
5458 state = HAS_STUB_SECTION;
5459 stub_table = group_end;
5460 stub_table_end_offset = group_end_offset;
5465 case HAS_STUB_SECTION:
5466 // Adding this section makes the post stub-section group larger
5468 if (section_end_offset - stub_table_end_offset >= group_size)
5470 gold_assert(group_end != this->input_sections().end());
5471 this->create_stub_group(group_begin, group_end, stub_table,
5472 target, &new_relaxed_sections);
5481 // If we see an input section and currently there is no group, start
5482 // a new one. Skip any empty sections.
5483 if ((p->is_input_section() || p->is_relaxed_input_section())
5484 && (p->relobj()->section_size(p->shndx()) != 0))
5486 if (state == NO_GROUP)
5488 state = FINDING_STUB_SECTION;
5490 group_begin_offset = section_begin_offset;
5493 // Keep track of the last input section seen.
5495 group_end_offset = section_end_offset;
5498 off = section_end_offset;
5501 // Create a stub group for any ungrouped sections.
5502 if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION)
5504 gold_assert(group_end != this->input_sections().end());
5505 this->create_stub_group(group_begin, group_end,
5506 (state == FINDING_STUB_SECTION
5509 target, &new_relaxed_sections);
5512 // Convert input section into relaxed input section in a batch.
5513 if (!new_relaxed_sections.empty())
5514 this->convert_input_sections_to_relaxed_sections(new_relaxed_sections);
5516 // Update the section offsets
5517 for (size_t i = 0; i < new_relaxed_sections.size(); ++i)
5519 Arm_relobj<big_endian>* arm_relobj =
5520 Arm_relobj<big_endian>::as_arm_relobj(
5521 new_relaxed_sections[i]->relobj());
5522 unsigned int shndx = new_relaxed_sections[i]->shndx();
5523 // Tell Arm_relobj that this input section is converted.
5524 arm_relobj->convert_input_section_to_relaxed_section(shndx);
5528 // Append non empty text sections in this to LIST in ascending
5529 // order of their position in this.
5531 template<bool big_endian>
5533 Arm_output_section<big_endian>::append_text_sections_to_list(
5534 Text_section_list* list)
5536 // We only care about text sections.
5537 if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0)
5540 gold_assert((this->flags() & elfcpp::SHF_ALLOC) != 0);
5542 for (Input_section_list::const_iterator p = this->input_sections().begin();
5543 p != this->input_sections().end();
5546 // We only care about plain or relaxed input sections. We also
5547 // ignore any merged sections.
5548 if ((p->is_input_section() || p->is_relaxed_input_section())
5549 && p->data_size() != 0)
5550 list->push_back(Text_section_list::value_type(p->relobj(),
5555 template<bool big_endian>
5557 Arm_output_section<big_endian>::fix_exidx_coverage(
5559 const Text_section_list& sorted_text_sections,
5560 Symbol_table* symtab)
5562 // We should only do this for the EXIDX output section.
5563 gold_assert(this->type() == elfcpp::SHT_ARM_EXIDX);
5565 // We don't want the relaxation loop to undo these changes, so we discard
5566 // the current saved states and take another one after the fix-up.
5567 this->discard_states();
5569 // Remove all input sections.
5570 uint64_t address = this->address();
5571 typedef std::list<Simple_input_section> Simple_input_section_list;
5572 Simple_input_section_list input_sections;
5573 this->reset_address_and_file_offset();
5574 this->get_input_sections(address, std::string(""), &input_sections);
5576 if (!this->input_sections().empty())
5577 gold_error(_("Found non-EXIDX input sections in EXIDX output section"));
5579 // Go through all the known input sections and record them.
5580 typedef Unordered_set<Section_id, Section_id_hash> Section_id_set;
5581 Section_id_set known_input_sections;
5582 for (Simple_input_section_list::const_iterator p = input_sections.begin();
5583 p != input_sections.end();
5586 // This should never happen. At this point, we should only see
5587 // plain EXIDX input sections.
5588 gold_assert(!p->is_relaxed_input_section());
5589 known_input_sections.insert(Section_id(p->relobj(), p->shndx()));
5592 Arm_exidx_fixup exidx_fixup(this);
5594 // Go over the sorted text sections.
5595 Section_id_set processed_input_sections;
5596 for (Text_section_list::const_iterator p = sorted_text_sections.begin();
5597 p != sorted_text_sections.end();
5600 Relobj* relobj = p->first;
5601 unsigned int shndx = p->second;
5603 Arm_relobj<big_endian>* arm_relobj =
5604 Arm_relobj<big_endian>::as_arm_relobj(relobj);
5605 const Arm_exidx_input_section* exidx_input_section =
5606 arm_relobj->exidx_input_section_by_link(shndx);
5608 // If this text section has no EXIDX section, force an EXIDX_CANTUNWIND
5609 // entry pointing to the end of the last seen EXIDX section.
5610 if (exidx_input_section == NULL)
5612 exidx_fixup.add_exidx_cantunwind_as_needed();
5616 Relobj* exidx_relobj = exidx_input_section->relobj();
5617 unsigned int exidx_shndx = exidx_input_section->shndx();
5618 Section_id sid(exidx_relobj, exidx_shndx);
5619 if (known_input_sections.find(sid) == known_input_sections.end())
5621 // This is odd. We have not seen this EXIDX input section before.
5622 // We cannot do fix-up. If we saw a SECTIONS clause in a script,
5623 // issue a warning instead. We assume the user knows what he
5624 // or she is doing. Otherwise, this is an error.
5625 if (layout->script_options()->saw_sections_clause())
5626 gold_warning(_("unwinding may not work because EXIDX input section"
5627 " %u of %s is not in EXIDX output section"),
5628 exidx_shndx, exidx_relobj->name().c_str());
5630 gold_error(_("unwinding may not work because EXIDX input section"
5631 " %u of %s is not in EXIDX output section"),
5632 exidx_shndx, exidx_relobj->name().c_str());
5634 exidx_fixup.add_exidx_cantunwind_as_needed();
5638 // Fix up coverage and append input section to output data list.
5639 Arm_exidx_section_offset_map* section_offset_map = NULL;
5640 uint32_t deleted_bytes =
5641 exidx_fixup.process_exidx_section<big_endian>(exidx_input_section,
5642 §ion_offset_map);
5644 if (deleted_bytes == exidx_input_section->size())
5646 // The whole EXIDX section got merged. Remove it from output.
5647 gold_assert(section_offset_map == NULL);
5648 exidx_relobj->set_output_section(exidx_shndx, NULL);
5650 // All local symbols defined in this input section will be dropped.
5651 // We need to adjust output local symbol count.
5652 arm_relobj->set_output_local_symbol_count_needs_update();
5654 else if (deleted_bytes > 0)
5656 // Some entries are merged. We need to convert this EXIDX input
5657 // section into a relaxed section.
5658 gold_assert(section_offset_map != NULL);
5659 Arm_exidx_merged_section* merged_section =
5660 new Arm_exidx_merged_section(*exidx_input_section,
5661 *section_offset_map, deleted_bytes);
5662 this->add_relaxed_input_section(merged_section);
5663 arm_relobj->convert_input_section_to_relaxed_section(exidx_shndx);
5665 // All local symbols defined in discarded portions of this input
5666 // section will be dropped. We need to adjust output local symbol
5668 arm_relobj->set_output_local_symbol_count_needs_update();
5672 // Just add back the EXIDX input section.
5673 gold_assert(section_offset_map == NULL);
5674 Output_section::Simple_input_section sis(exidx_relobj, exidx_shndx);
5675 this->add_simple_input_section(sis, exidx_input_section->size(),
5676 exidx_input_section->addralign());
5679 processed_input_sections.insert(Section_id(exidx_relobj, exidx_shndx));
5682 // Insert an EXIDX_CANTUNWIND entry at the end of output if necessary.
5683 exidx_fixup.add_exidx_cantunwind_as_needed();
5685 // Remove any known EXIDX input sections that are not processed.
5686 for (Simple_input_section_list::const_iterator p = input_sections.begin();
5687 p != input_sections.end();
5690 if (processed_input_sections.find(Section_id(p->relobj(), p->shndx()))
5691 == processed_input_sections.end())
5693 // We only discard a known EXIDX section because its linked
5694 // text section has been folded by ICF.
5695 Arm_relobj<big_endian>* arm_relobj =
5696 Arm_relobj<big_endian>::as_arm_relobj(p->relobj());
5697 const Arm_exidx_input_section* exidx_input_section =
5698 arm_relobj->exidx_input_section_by_shndx(p->shndx());
5699 gold_assert(exidx_input_section != NULL);
5700 unsigned int text_shndx = exidx_input_section->link();
5701 gold_assert(symtab->is_section_folded(p->relobj(), text_shndx));
5703 // Remove this from link.
5704 p->relobj()->set_output_section(p->shndx(), NULL);
5708 // Link exidx output section to the first seen output section and
5709 // set correct entry size.
5710 this->set_link_section(exidx_fixup.first_output_text_section());
5711 this->set_entsize(8);
5713 // Make changes permanent.
5714 this->save_states();
5715 this->set_section_offsets_need_adjustment();
5718 // Arm_relobj methods.
5720 // Determine if an input section is scannable for stub processing. SHDR is
5721 // the header of the section and SHNDX is the section index. OS is the output
5722 // section for the input section and SYMTAB is the global symbol table used to
5723 // look up ICF information.
5725 template<bool big_endian>
5727 Arm_relobj<big_endian>::section_is_scannable(
5728 const elfcpp::Shdr<32, big_endian>& shdr,
5730 const Output_section* os,
5731 const Symbol_table *symtab)
5733 // Skip any empty sections, unallocated sections or sections whose
5734 // type are not SHT_PROGBITS.
5735 if (shdr.get_sh_size() == 0
5736 || (shdr.get_sh_flags() & elfcpp::SHF_ALLOC) == 0
5737 || shdr.get_sh_type() != elfcpp::SHT_PROGBITS)
5740 // Skip any discarded or ICF'ed sections.
5741 if (os == NULL || symtab->is_section_folded(this, shndx))
5744 // If this requires special offset handling, check to see if it is
5745 // a relaxed section. If this is not, then it is a merged section that
5746 // we cannot handle.
5747 if (this->is_output_section_offset_invalid(shndx))
5749 const Output_relaxed_input_section* poris =
5750 os->find_relaxed_input_section(this, shndx);
5758 // Determine if we want to scan the SHNDX-th section for relocation stubs.
5759 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5761 template<bool big_endian>
5763 Arm_relobj<big_endian>::section_needs_reloc_stub_scanning(
5764 const elfcpp::Shdr<32, big_endian>& shdr,
5765 const Relobj::Output_sections& out_sections,
5766 const Symbol_table *symtab,
5767 const unsigned char* pshdrs)
5769 unsigned int sh_type = shdr.get_sh_type();
5770 if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA)
5773 // Ignore empty section.
5774 off_t sh_size = shdr.get_sh_size();
5778 // Ignore reloc section with unexpected symbol table. The
5779 // error will be reported in the final link.
5780 if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx())
5783 unsigned int reloc_size;
5784 if (sh_type == elfcpp::SHT_REL)
5785 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
5787 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
5789 // Ignore reloc section with unexpected entsize or uneven size.
5790 // The error will be reported in the final link.
5791 if (reloc_size != shdr.get_sh_entsize() || sh_size % reloc_size != 0)
5794 // Ignore reloc section with bad info. This error will be
5795 // reported in the final link.
5796 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
5797 if (index >= this->shnum())
5800 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
5801 const elfcpp::Shdr<32, big_endian> text_shdr(pshdrs + index * shdr_size);
5802 return this->section_is_scannable(text_shdr, index,
5803 out_sections[index], symtab);
5806 // Return the output address of either a plain input section or a relaxed
5807 // input section. SHNDX is the section index. We define and use this
5808 // instead of calling Output_section::output_address because that is slow
5809 // for large output.
5811 template<bool big_endian>
5813 Arm_relobj<big_endian>::simple_input_section_output_address(
5817 if (this->is_output_section_offset_invalid(shndx))
5819 const Output_relaxed_input_section* poris =
5820 os->find_relaxed_input_section(this, shndx);
5821 // We do not handle merged sections here.
5822 gold_assert(poris != NULL);
5823 return poris->address();
5826 return os->address() + this->get_output_section_offset(shndx);
5829 // Determine if we want to scan the SHNDX-th section for non-relocation stubs.
5830 // This is a helper for Arm_relobj::scan_sections_for_stubs() below.
5832 template<bool big_endian>
5834 Arm_relobj<big_endian>::section_needs_cortex_a8_stub_scanning(
5835 const elfcpp::Shdr<32, big_endian>& shdr,
5838 const Symbol_table* symtab)
5840 if (!this->section_is_scannable(shdr, shndx, os, symtab))
5843 // If the section does not cross any 4K-boundaries, it does not need to
5845 Arm_address address = this->simple_input_section_output_address(shndx, os);
5846 if ((address & ~0xfffU) == ((address + shdr.get_sh_size() - 1) & ~0xfffU))
5852 // Scan a section for Cortex-A8 workaround.
5854 template<bool big_endian>
5856 Arm_relobj<big_endian>::scan_section_for_cortex_a8_erratum(
5857 const elfcpp::Shdr<32, big_endian>& shdr,
5860 Target_arm<big_endian>* arm_target)
5862 // Look for the first mapping symbol in this section. It should be
5864 Mapping_symbol_position section_start(shndx, 0);
5865 typename Mapping_symbols_info::const_iterator p =
5866 this->mapping_symbols_info_.lower_bound(section_start);
5868 // There are no mapping symbols for this section. Treat it as a data-only
5869 // section. Issue a warning if section is marked as containing
5871 if (p == this->mapping_symbols_info_.end() || p->first.first != shndx)
5873 if ((this->section_flags(shndx) & elfcpp::SHF_EXECINSTR) != 0)
5874 gold_warning(_("cannot scan executable section %u of %s for Cortex-A8 "
5875 "erratum because it has no mapping symbols."),
5876 shndx, this->name().c_str());
5880 Arm_address output_address =
5881 this->simple_input_section_output_address(shndx, os);
5883 // Get the section contents.
5884 section_size_type input_view_size = 0;
5885 const unsigned char* input_view =
5886 this->section_contents(shndx, &input_view_size, false);
5888 // We need to go through the mapping symbols to determine what to
5889 // scan. There are two reasons. First, we should look at THUMB code and
5890 // THUMB code only. Second, we only want to look at the 4K-page boundary
5891 // to speed up the scanning.
5893 while (p != this->mapping_symbols_info_.end()
5894 && p->first.first == shndx)
5896 typename Mapping_symbols_info::const_iterator next =
5897 this->mapping_symbols_info_.upper_bound(p->first);
5899 // Only scan part of a section with THUMB code.
5900 if (p->second == 't')
5902 // Determine the end of this range.
5903 section_size_type span_start =
5904 convert_to_section_size_type(p->first.second);
5905 section_size_type span_end;
5906 if (next != this->mapping_symbols_info_.end()
5907 && next->first.first == shndx)
5908 span_end = convert_to_section_size_type(next->first.second);
5910 span_end = convert_to_section_size_type(shdr.get_sh_size());
5912 if (((span_start + output_address) & ~0xfffUL)
5913 != ((span_end + output_address - 1) & ~0xfffUL))
5915 arm_target->scan_span_for_cortex_a8_erratum(this, shndx,
5916 span_start, span_end,
5926 // Scan relocations for stub generation.
5928 template<bool big_endian>
5930 Arm_relobj<big_endian>::scan_sections_for_stubs(
5931 Target_arm<big_endian>* arm_target,
5932 const Symbol_table* symtab,
5933 const Layout* layout)
5935 unsigned int shnum = this->shnum();
5936 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
5938 // Read the section headers.
5939 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
5943 // To speed up processing, we set up hash tables for fast lookup of
5944 // input offsets to output addresses.
5945 this->initialize_input_to_output_maps();
5947 const Relobj::Output_sections& out_sections(this->output_sections());
5949 Relocate_info<32, big_endian> relinfo;
5950 relinfo.symtab = symtab;
5951 relinfo.layout = layout;
5952 relinfo.object = this;
5954 // Do relocation stubs scanning.
5955 const unsigned char* p = pshdrs + shdr_size;
5956 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
5958 const elfcpp::Shdr<32, big_endian> shdr(p);
5959 if (this->section_needs_reloc_stub_scanning(shdr, out_sections, symtab,
5962 unsigned int index = this->adjust_shndx(shdr.get_sh_info());
5963 Arm_address output_offset = this->get_output_section_offset(index);
5964 Arm_address output_address;
5965 if (output_offset != invalid_address)
5966 output_address = out_sections[index]->address() + output_offset;
5969 // Currently this only happens for a relaxed section.
5970 const Output_relaxed_input_section* poris =
5971 out_sections[index]->find_relaxed_input_section(this, index);
5972 gold_assert(poris != NULL);
5973 output_address = poris->address();
5976 // Get the relocations.
5977 const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(),
5981 // Get the section contents. This does work for the case in which
5982 // we modify the contents of an input section. We need to pass the
5983 // output view under such circumstances.
5984 section_size_type input_view_size = 0;
5985 const unsigned char* input_view =
5986 this->section_contents(index, &input_view_size, false);
5988 relinfo.reloc_shndx = i;
5989 relinfo.data_shndx = index;
5990 unsigned int sh_type = shdr.get_sh_type();
5991 unsigned int reloc_size;
5992 if (sh_type == elfcpp::SHT_REL)
5993 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
5995 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
5997 Output_section* os = out_sections[index];
5998 arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs,
5999 shdr.get_sh_size() / reloc_size,
6001 output_offset == invalid_address,
6002 input_view, output_address,
6007 // Do Cortex-A8 erratum stubs scanning. This has to be done for a section
6008 // after its relocation section, if there is one, is processed for
6009 // relocation stubs. Merging this loop with the one above would have been
6010 // complicated since we would have had to make sure that relocation stub
6011 // scanning is done first.
6012 if (arm_target->fix_cortex_a8())
6014 const unsigned char* p = pshdrs + shdr_size;
6015 for (unsigned int i = 1; i < shnum; ++i, p += shdr_size)
6017 const elfcpp::Shdr<32, big_endian> shdr(p);
6018 if (this->section_needs_cortex_a8_stub_scanning(shdr, i,
6021 this->scan_section_for_cortex_a8_erratum(shdr, i, out_sections[i],
6026 // After we've done the relocations, we release the hash tables,
6027 // since we no longer need them.
6028 this->free_input_to_output_maps();
6031 // Count the local symbols. The ARM backend needs to know if a symbol
6032 // is a THUMB function or not. For global symbols, it is easy because
6033 // the Symbol object keeps the ELF symbol type. For local symbol it is
6034 // harder because we cannot access this information. So we override the
6035 // do_count_local_symbol in parent and scan local symbols to mark
6036 // THUMB functions. This is not the most efficient way but I do not want to
6037 // slow down other ports by calling a per symbol targer hook inside
6038 // Sized_relobj<size, big_endian>::do_count_local_symbols.
6040 template<bool big_endian>
6042 Arm_relobj<big_endian>::do_count_local_symbols(
6043 Stringpool_template<char>* pool,
6044 Stringpool_template<char>* dynpool)
6046 // We need to fix-up the values of any local symbols whose type are
6049 // Ask parent to count the local symbols.
6050 Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool);
6051 const unsigned int loccount = this->local_symbol_count();
6055 // Intialize the thumb function bit-vector.
6056 std::vector<bool> empty_vector(loccount, false);
6057 this->local_symbol_is_thumb_function_.swap(empty_vector);
6059 // Read the symbol table section header.
6060 const unsigned int symtab_shndx = this->symtab_shndx();
6061 elfcpp::Shdr<32, big_endian>
6062 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6063 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6065 // Read the local symbols.
6066 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6067 gold_assert(loccount == symtabshdr.get_sh_info());
6068 off_t locsize = loccount * sym_size;
6069 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6070 locsize, true, true);
6072 // For mapping symbol processing, we need to read the symbol names.
6073 unsigned int strtab_shndx = this->adjust_shndx(symtabshdr.get_sh_link());
6074 if (strtab_shndx >= this->shnum())
6076 this->error(_("invalid symbol table name index: %u"), strtab_shndx);
6080 elfcpp::Shdr<32, big_endian>
6081 strtabshdr(this, this->elf_file()->section_header(strtab_shndx));
6082 if (strtabshdr.get_sh_type() != elfcpp::SHT_STRTAB)
6084 this->error(_("symbol table name section has wrong type: %u"),
6085 static_cast<unsigned int>(strtabshdr.get_sh_type()));
6088 const char* pnames =
6089 reinterpret_cast<const char*>(this->get_view(strtabshdr.get_sh_offset(),
6090 strtabshdr.get_sh_size(),
6093 // Loop over the local symbols and mark any local symbols pointing
6094 // to THUMB functions.
6096 // Skip the first dummy symbol.
6098 typename Sized_relobj<32, big_endian>::Local_values* plocal_values =
6099 this->local_values();
6100 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6102 elfcpp::Sym<32, big_endian> sym(psyms);
6103 elfcpp::STT st_type = sym.get_st_type();
6104 Symbol_value<32>& lv((*plocal_values)[i]);
6105 Arm_address input_value = lv.input_value();
6107 // Check to see if this is a mapping symbol.
6108 const char* sym_name = pnames + sym.get_st_name();
6109 if (Target_arm<big_endian>::is_mapping_symbol_name(sym_name))
6112 unsigned int input_shndx =
6113 this->adjust_sym_shndx(i, sym.get_st_shndx(), &is_ordinary);
6114 gold_assert(is_ordinary);
6116 // Strip of LSB in case this is a THUMB symbol.
6117 Mapping_symbol_position msp(input_shndx, input_value & ~1U);
6118 this->mapping_symbols_info_[msp] = sym_name[1];
6121 if (st_type == elfcpp::STT_ARM_TFUNC
6122 || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0)))
6124 // This is a THUMB function. Mark this and canonicalize the
6125 // symbol value by setting LSB.
6126 this->local_symbol_is_thumb_function_[i] = true;
6127 if ((input_value & 1) == 0)
6128 lv.set_input_value(input_value | 1);
6133 // Relocate sections.
6134 template<bool big_endian>
6136 Arm_relobj<big_endian>::do_relocate_sections(
6137 const Symbol_table* symtab,
6138 const Layout* layout,
6139 const unsigned char* pshdrs,
6140 typename Sized_relobj<32, big_endian>::Views* pviews)
6142 // Call parent to relocate sections.
6143 Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs,
6146 // We do not generate stubs if doing a relocatable link.
6147 if (parameters->options().relocatable())
6150 // Relocate stub tables.
6151 unsigned int shnum = this->shnum();
6153 Target_arm<big_endian>* arm_target =
6154 Target_arm<big_endian>::default_target();
6156 Relocate_info<32, big_endian> relinfo;
6157 relinfo.symtab = symtab;
6158 relinfo.layout = layout;
6159 relinfo.object = this;
6161 for (unsigned int i = 1; i < shnum; ++i)
6163 Arm_input_section<big_endian>* arm_input_section =
6164 arm_target->find_arm_input_section(this, i);
6166 if (arm_input_section != NULL
6167 && arm_input_section->is_stub_table_owner()
6168 && !arm_input_section->stub_table()->empty())
6170 // We cannot discard a section if it owns a stub table.
6171 Output_section* os = this->output_section(i);
6172 gold_assert(os != NULL);
6174 relinfo.reloc_shndx = elfcpp::SHN_UNDEF;
6175 relinfo.reloc_shdr = NULL;
6176 relinfo.data_shndx = i;
6177 relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size;
6179 gold_assert((*pviews)[i].view != NULL);
6181 // We are passed the output section view. Adjust it to cover the
6183 Stub_table<big_endian>* stub_table = arm_input_section->stub_table();
6184 gold_assert((stub_table->address() >= (*pviews)[i].address)
6185 && ((stub_table->address() + stub_table->data_size())
6186 <= (*pviews)[i].address + (*pviews)[i].view_size));
6188 off_t offset = stub_table->address() - (*pviews)[i].address;
6189 unsigned char* view = (*pviews)[i].view + offset;
6190 Arm_address address = stub_table->address();
6191 section_size_type view_size = stub_table->data_size();
6193 stub_table->relocate_stubs(&relinfo, arm_target, os, view, address,
6197 // Apply Cortex A8 workaround if applicable.
6198 if (this->section_has_cortex_a8_workaround(i))
6200 unsigned char* view = (*pviews)[i].view;
6201 Arm_address view_address = (*pviews)[i].address;
6202 section_size_type view_size = (*pviews)[i].view_size;
6203 Stub_table<big_endian>* stub_table = this->stub_tables_[i];
6205 // Adjust view to cover section.
6206 Output_section* os = this->output_section(i);
6207 gold_assert(os != NULL);
6208 Arm_address section_address =
6209 this->simple_input_section_output_address(i, os);
6210 uint64_t section_size = this->section_size(i);
6212 gold_assert(section_address >= view_address
6213 && ((section_address + section_size)
6214 <= (view_address + view_size)));
6216 unsigned char* section_view = view + (section_address - view_address);
6218 // Apply the Cortex-A8 workaround to the output address range
6219 // corresponding to this input section.
6220 stub_table->apply_cortex_a8_workaround_to_address_range(
6229 // Find the linked text section of an EXIDX section by looking the the first
6230 // relocation. 4.4.1 of the EHABI specifications says that an EXIDX section
6231 // must be linked to to its associated code section via the sh_link field of
6232 // its section header. However, some tools are broken and the link is not
6233 // always set. LD just drops such an EXIDX section silently, causing the
6234 // associated code not unwindabled. Here we try a little bit harder to
6235 // discover the linked code section.
6237 // PSHDR points to the section header of a relocation section of an EXIDX
6238 // section. If we can find a linked text section, return true and
6239 // store the text section index in the location PSHNDX. Otherwise
6242 template<bool big_endian>
6244 Arm_relobj<big_endian>::find_linked_text_section(
6245 const unsigned char* pshdr,
6246 const unsigned char* psyms,
6247 unsigned int* pshndx)
6249 elfcpp::Shdr<32, big_endian> shdr(pshdr);
6251 // If there is no relocation, we cannot find the linked text section.
6253 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6254 reloc_size = elfcpp::Elf_sizes<32>::rel_size;
6256 reloc_size = elfcpp::Elf_sizes<32>::rela_size;
6257 size_t reloc_count = shdr.get_sh_size() / reloc_size;
6259 // Get the relocations.
6260 const unsigned char* prelocs =
6261 this->get_view(shdr.get_sh_offset(), shdr.get_sh_size(), true, false);
6263 // Find the REL31 relocation for the first word of the first EXIDX entry.
6264 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
6266 Arm_address r_offset;
6267 typename elfcpp::Elf_types<32>::Elf_WXword r_info;
6268 if (shdr.get_sh_type() == elfcpp::SHT_REL)
6270 typename elfcpp::Rel<32, big_endian> reloc(prelocs);
6271 r_info = reloc.get_r_info();
6272 r_offset = reloc.get_r_offset();
6276 typename elfcpp::Rela<32, big_endian> reloc(prelocs);
6277 r_info = reloc.get_r_info();
6278 r_offset = reloc.get_r_offset();
6281 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
6282 if (r_type != elfcpp::R_ARM_PREL31 && r_type != elfcpp::R_ARM_SBREL31)
6285 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
6287 || r_sym >= this->local_symbol_count()
6291 // This is the relocation for the first word of the first EXIDX entry.
6292 // We expect to see a local section symbol.
6293 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6294 elfcpp::Sym<32, big_endian> sym(psyms + r_sym * sym_size);
6295 if (sym.get_st_type() == elfcpp::STT_SECTION)
6299 this->adjust_sym_shndx(r_sym, sym.get_st_shndx(), &is_ordinary);
6300 gold_assert(is_ordinary);
6310 // Make an EXIDX input section object for an EXIDX section whose index is
6311 // SHNDX. SHDR is the section header of the EXIDX section and TEXT_SHNDX
6312 // is the section index of the linked text section.
6314 template<bool big_endian>
6316 Arm_relobj<big_endian>::make_exidx_input_section(
6318 const elfcpp::Shdr<32, big_endian>& shdr,
6319 unsigned int text_shndx)
6321 // Issue an error and ignore this EXIDX section if it points to a text
6322 // section already has an EXIDX section.
6323 if (this->exidx_section_map_[text_shndx] != NULL)
6325 gold_error(_("EXIDX sections %u and %u both link to text section %u "
6327 shndx, this->exidx_section_map_[text_shndx]->shndx(),
6328 text_shndx, this->name().c_str());
6332 // Create an Arm_exidx_input_section object for this EXIDX section.
6333 Arm_exidx_input_section* exidx_input_section =
6334 new Arm_exidx_input_section(this, shndx, text_shndx, shdr.get_sh_size(),
6335 shdr.get_sh_addralign());
6336 this->exidx_section_map_[text_shndx] = exidx_input_section;
6338 // Also map the EXIDX section index to this.
6339 gold_assert(this->exidx_section_map_[shndx] == NULL);
6340 this->exidx_section_map_[shndx] = exidx_input_section;
6343 // Read the symbol information.
6345 template<bool big_endian>
6347 Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6349 // Call parent class to read symbol information.
6350 Sized_relobj<32, big_endian>::do_read_symbols(sd);
6352 // If this input file is a binary file, it has no processor
6353 // specific flags and attributes section.
6354 Input_file::Format format = this->input_file()->format();
6355 if (format != Input_file::FORMAT_ELF)
6357 gold_assert(format == Input_file::FORMAT_BINARY);
6358 this->merge_flags_and_attributes_ = false;
6362 // Read processor-specific flags in ELF file header.
6363 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6364 elfcpp::Elf_sizes<32>::ehdr_size,
6366 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6367 this->processor_specific_flags_ = ehdr.get_e_flags();
6369 // Go over the section headers and look for .ARM.attributes and .ARM.exidx
6371 std::vector<unsigned int> deferred_exidx_sections;
6372 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6373 const unsigned char* pshdrs = sd->section_headers->data();
6374 const unsigned char *ps = pshdrs + shdr_size;
6375 bool must_merge_flags_and_attributes = false;
6376 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6378 elfcpp::Shdr<32, big_endian> shdr(ps);
6380 // Sometimes an object has no contents except the section name string
6381 // table and an empty symbol table with the undefined symbol. We
6382 // don't want to merge processor-specific flags from such an object.
6383 if (shdr.get_sh_type() == elfcpp::SHT_SYMTAB)
6385 // Symbol table is not empty.
6386 const elfcpp::Elf_types<32>::Elf_WXword sym_size =
6387 elfcpp::Elf_sizes<32>::sym_size;
6388 if (shdr.get_sh_size() > sym_size)
6389 must_merge_flags_and_attributes = true;
6391 else if (shdr.get_sh_type() != elfcpp::SHT_STRTAB)
6392 // If this is neither an empty symbol table nor a string table,
6394 must_merge_flags_and_attributes = true;
6396 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6398 gold_assert(this->attributes_section_data_ == NULL);
6399 section_offset_type section_offset = shdr.get_sh_offset();
6400 section_size_type section_size =
6401 convert_to_section_size_type(shdr.get_sh_size());
6402 File_view* view = this->get_lasting_view(section_offset,
6403 section_size, true, false);
6404 this->attributes_section_data_ =
6405 new Attributes_section_data(view->data(), section_size);
6407 else if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6409 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6410 if (text_shndx >= this->shnum())
6411 gold_error(_("EXIDX section %u linked to invalid section %u"),
6413 else if (text_shndx == elfcpp::SHN_UNDEF)
6414 deferred_exidx_sections.push_back(i);
6416 this->make_exidx_input_section(i, shdr, text_shndx);
6421 if (!must_merge_flags_and_attributes)
6423 this->merge_flags_and_attributes_ = false;
6427 // Some tools are broken and they do not set the link of EXIDX sections.
6428 // We look at the first relocation to figure out the linked sections.
6429 if (!deferred_exidx_sections.empty())
6431 // We need to go over the section headers again to find the mapping
6432 // from sections being relocated to their relocation sections. This is
6433 // a bit inefficient as we could do that in the loop above. However,
6434 // we do not expect any deferred EXIDX sections normally. So we do not
6435 // want to slow down the most common path.
6436 typedef Unordered_map<unsigned int, unsigned int> Reloc_map;
6437 Reloc_map reloc_map;
6438 ps = pshdrs + shdr_size;
6439 for (unsigned int i = 1; i < this->shnum(); ++i, ps += shdr_size)
6441 elfcpp::Shdr<32, big_endian> shdr(ps);
6442 elfcpp::Elf_Word sh_type = shdr.get_sh_type();
6443 if (sh_type == elfcpp::SHT_REL || sh_type == elfcpp::SHT_RELA)
6445 unsigned int info_shndx = this->adjust_shndx(shdr.get_sh_info());
6446 if (info_shndx >= this->shnum())
6447 gold_error(_("relocation section %u has invalid info %u"),
6449 Reloc_map::value_type value(info_shndx, i);
6450 std::pair<Reloc_map::iterator, bool> result =
6451 reloc_map.insert(value);
6453 gold_error(_("section %u has multiple relocation sections "
6455 info_shndx, i, reloc_map[info_shndx]);
6459 // Read the symbol table section header.
6460 const unsigned int symtab_shndx = this->symtab_shndx();
6461 elfcpp::Shdr<32, big_endian>
6462 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6463 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6465 // Read the local symbols.
6466 const int sym_size =elfcpp::Elf_sizes<32>::sym_size;
6467 const unsigned int loccount = this->local_symbol_count();
6468 gold_assert(loccount == symtabshdr.get_sh_info());
6469 off_t locsize = loccount * sym_size;
6470 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6471 locsize, true, true);
6473 // Process the deferred EXIDX sections.
6474 for(unsigned int i = 0; i < deferred_exidx_sections.size(); ++i)
6476 unsigned int shndx = deferred_exidx_sections[i];
6477 elfcpp::Shdr<32, big_endian> shdr(pshdrs + shndx * shdr_size);
6478 unsigned int text_shndx;
6479 Reloc_map::const_iterator it = reloc_map.find(shndx);
6480 if (it != reloc_map.end()
6481 && find_linked_text_section(pshdrs + it->second * shdr_size,
6482 psyms, &text_shndx))
6483 this->make_exidx_input_section(shndx, shdr, text_shndx);
6485 gold_error(_("EXIDX section %u has no linked text section."),
6491 // Process relocations for garbage collection. The ARM target uses .ARM.exidx
6492 // sections for unwinding. These sections are referenced implicitly by
6493 // text sections linked in the section headers. If we ignore these implict
6494 // references, the .ARM.exidx sections and any .ARM.extab sections they use
6495 // will be garbage-collected incorrectly. Hence we override the same function
6496 // in the base class to handle these implicit references.
6498 template<bool big_endian>
6500 Arm_relobj<big_endian>::do_gc_process_relocs(Symbol_table* symtab,
6502 Read_relocs_data* rd)
6504 // First, call base class method to process relocations in this object.
6505 Sized_relobj<32, big_endian>::do_gc_process_relocs(symtab, layout, rd);
6507 // If --gc-sections is not specified, there is nothing more to do.
6508 // This happens when --icf is used but --gc-sections is not.
6509 if (!parameters->options().gc_sections())
6512 unsigned int shnum = this->shnum();
6513 const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6514 const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(),
6518 // Scan section headers for sections of type SHT_ARM_EXIDX. Add references
6519 // to these from the linked text sections.
6520 const unsigned char* ps = pshdrs + shdr_size;
6521 for (unsigned int i = 1; i < shnum; ++i, ps += shdr_size)
6523 elfcpp::Shdr<32, big_endian> shdr(ps);
6524 if (shdr.get_sh_type() == elfcpp::SHT_ARM_EXIDX)
6526 // Found an .ARM.exidx section, add it to the set of reachable
6527 // sections from its linked text section.
6528 unsigned int text_shndx = this->adjust_shndx(shdr.get_sh_link());
6529 symtab->gc()->add_reference(this, text_shndx, this, i);
6534 // Update output local symbol count. Owing to EXIDX entry merging, some local
6535 // symbols will be removed in output. Adjust output local symbol count
6536 // accordingly. We can only changed the static output local symbol count. It
6537 // is too late to change the dynamic symbols.
6539 template<bool big_endian>
6541 Arm_relobj<big_endian>::update_output_local_symbol_count()
6543 // Caller should check that this needs updating. We want caller checking
6544 // because output_local_symbol_count_needs_update() is most likely inlined.
6545 gold_assert(this->output_local_symbol_count_needs_update_);
6547 gold_assert(this->symtab_shndx() != -1U);
6548 if (this->symtab_shndx() == 0)
6550 // This object has no symbols. Weird but legal.
6554 // Read the symbol table section header.
6555 const unsigned int symtab_shndx = this->symtab_shndx();
6556 elfcpp::Shdr<32, big_endian>
6557 symtabshdr(this, this->elf_file()->section_header(symtab_shndx));
6558 gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB);
6560 // Read the local symbols.
6561 const int sym_size = elfcpp::Elf_sizes<32>::sym_size;
6562 const unsigned int loccount = this->local_symbol_count();
6563 gold_assert(loccount == symtabshdr.get_sh_info());
6564 off_t locsize = loccount * sym_size;
6565 const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(),
6566 locsize, true, true);
6568 // Loop over the local symbols.
6570 typedef typename Sized_relobj<32, big_endian>::Output_sections
6572 const Output_sections& out_sections(this->output_sections());
6573 unsigned int shnum = this->shnum();
6574 unsigned int count = 0;
6575 // Skip the first, dummy, symbol.
6577 for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size)
6579 elfcpp::Sym<32, big_endian> sym(psyms);
6581 Symbol_value<32>& lv((*this->local_values())[i]);
6583 // This local symbol was already discarded by do_count_local_symbols.
6584 if (lv.is_output_symtab_index_set() && !lv.has_output_symtab_entry())
6588 unsigned int shndx = this->adjust_sym_shndx(i, sym.get_st_shndx(),
6593 Output_section* os = out_sections[shndx];
6595 // This local symbol no longer has an output section. Discard it.
6598 lv.set_no_output_symtab_entry();
6602 // Currently we only discard parts of EXIDX input sections.
6603 // We explicitly check for a merged EXIDX input section to avoid
6604 // calling Output_section_data::output_offset unless necessary.
6605 if ((this->get_output_section_offset(shndx) == invalid_address)
6606 && (this->exidx_input_section_by_shndx(shndx) != NULL))
6608 section_offset_type output_offset =
6609 os->output_offset(this, shndx, lv.input_value());
6610 if (output_offset == -1)
6612 // This symbol is defined in a part of an EXIDX input section
6613 // that is discarded due to entry merging.
6614 lv.set_no_output_symtab_entry();
6623 this->set_output_local_symbol_count(count);
6624 this->output_local_symbol_count_needs_update_ = false;
6627 // Arm_dynobj methods.
6629 // Read the symbol information.
6631 template<bool big_endian>
6633 Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd)
6635 // Call parent class to read symbol information.
6636 Sized_dynobj<32, big_endian>::do_read_symbols(sd);
6638 // Read processor-specific flags in ELF file header.
6639 const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset,
6640 elfcpp::Elf_sizes<32>::ehdr_size,
6642 elfcpp::Ehdr<32, big_endian> ehdr(pehdr);
6643 this->processor_specific_flags_ = ehdr.get_e_flags();
6645 // Read the attributes section if there is one.
6646 // We read from the end because gas seems to put it near the end of
6647 // the section headers.
6648 const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size;
6649 const unsigned char *ps =
6650 sd->section_headers->data() + shdr_size * (this->shnum() - 1);
6651 for (unsigned int i = this->shnum(); i > 0; --i, ps -= shdr_size)
6653 elfcpp::Shdr<32, big_endian> shdr(ps);
6654 if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES)
6656 section_offset_type section_offset = shdr.get_sh_offset();
6657 section_size_type section_size =
6658 convert_to_section_size_type(shdr.get_sh_size());
6659 File_view* view = this->get_lasting_view(section_offset,
6660 section_size, true, false);
6661 this->attributes_section_data_ =
6662 new Attributes_section_data(view->data(), section_size);
6668 // Stub_addend_reader methods.
6670 // Read the addend of a REL relocation of type R_TYPE at VIEW.
6672 template<bool big_endian>
6673 elfcpp::Elf_types<32>::Elf_Swxword
6674 Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()(
6675 unsigned int r_type,
6676 const unsigned char* view,
6677 const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const
6679 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
6683 case elfcpp::R_ARM_CALL:
6684 case elfcpp::R_ARM_JUMP24:
6685 case elfcpp::R_ARM_PLT32:
6687 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6688 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6689 Valtype val = elfcpp::Swap<32, big_endian>::readval(wv);
6690 return utils::sign_extend<26>(val << 2);
6693 case elfcpp::R_ARM_THM_CALL:
6694 case elfcpp::R_ARM_THM_JUMP24:
6695 case elfcpp::R_ARM_THM_XPC22:
6697 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6698 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6699 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6700 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6701 return RelocFuncs::thumb32_branch_offset(upper_insn, lower_insn);
6704 case elfcpp::R_ARM_THM_JUMP19:
6706 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
6707 const Valtype* wv = reinterpret_cast<const Valtype*>(view);
6708 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
6709 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
6710 return RelocFuncs::thumb32_cond_branch_offset(upper_insn, lower_insn);
6718 // Arm_output_data_got methods.
6720 // Add a GOT pair for R_ARM_TLS_GD32. The creates a pair of GOT entries.
6721 // The first one is initialized to be 1, which is the module index for
6722 // the main executable and the second one 0. A reloc of the type
6723 // R_ARM_TLS_DTPOFF32 will be created for the second GOT entry and will
6724 // be applied by gold. GSYM is a global symbol.
6726 template<bool big_endian>
6728 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6729 unsigned int got_type,
6732 if (gsym->has_got_offset(got_type))
6735 // We are doing a static link. Just mark it as belong to module 1,
6737 unsigned int got_offset = this->add_constant(1);
6738 gsym->set_got_offset(got_type, got_offset);
6739 got_offset = this->add_constant(0);
6740 this->static_relocs_.push_back(Static_reloc(got_offset,
6741 elfcpp::R_ARM_TLS_DTPOFF32,
6745 // Same as the above but for a local symbol.
6747 template<bool big_endian>
6749 Arm_output_data_got<big_endian>::add_tls_gd32_with_static_reloc(
6750 unsigned int got_type,
6751 Sized_relobj<32, big_endian>* object,
6754 if (object->local_has_got_offset(index, got_type))
6757 // We are doing a static link. Just mark it as belong to module 1,
6759 unsigned int got_offset = this->add_constant(1);
6760 object->set_local_got_offset(index, got_type, got_offset);
6761 got_offset = this->add_constant(0);
6762 this->static_relocs_.push_back(Static_reloc(got_offset,
6763 elfcpp::R_ARM_TLS_DTPOFF32,
6767 template<bool big_endian>
6769 Arm_output_data_got<big_endian>::do_write(Output_file* of)
6771 // Call parent to write out GOT.
6772 Output_data_got<32, big_endian>::do_write(of);
6774 // We are done if there is no fix up.
6775 if (this->static_relocs_.empty())
6778 gold_assert(parameters->doing_static_link());
6780 const off_t offset = this->offset();
6781 const section_size_type oview_size =
6782 convert_to_section_size_type(this->data_size());
6783 unsigned char* const oview = of->get_output_view(offset, oview_size);
6785 Output_segment* tls_segment = this->layout_->tls_segment();
6786 gold_assert(tls_segment != NULL);
6788 // The thread pointer $tp points to the TCB, which is followed by the
6789 // TLS. So we need to adjust $tp relative addressing by this amount.
6790 Arm_address aligned_tcb_size =
6791 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
6793 for (size_t i = 0; i < this->static_relocs_.size(); ++i)
6795 Static_reloc& reloc(this->static_relocs_[i]);
6798 if (!reloc.symbol_is_global())
6800 Sized_relobj<32, big_endian>* object = reloc.relobj();
6801 const Symbol_value<32>* psymval =
6802 reloc.relobj()->local_symbol(reloc.index());
6804 // We are doing static linking. Issue an error and skip this
6805 // relocation if the symbol is undefined or in a discarded_section.
6807 unsigned int shndx = psymval->input_shndx(&is_ordinary);
6808 if ((shndx == elfcpp::SHN_UNDEF)
6810 && shndx != elfcpp::SHN_UNDEF
6811 && !object->is_section_included(shndx)
6812 && !this->symbol_table_->is_section_folded(object, shndx)))
6814 gold_error(_("undefined or discarded local symbol %u from "
6815 " object %s in GOT"),
6816 reloc.index(), reloc.relobj()->name().c_str());
6820 value = psymval->value(object, 0);
6824 const Symbol* gsym = reloc.symbol();
6825 gold_assert(gsym != NULL);
6826 if (gsym->is_forwarder())
6827 gsym = this->symbol_table_->resolve_forwards(gsym);
6829 // We are doing static linking. Issue an error and skip this
6830 // relocation if the symbol is undefined or in a discarded_section
6831 // unless it is a weakly_undefined symbol.
6832 if ((gsym->is_defined_in_discarded_section()
6833 || gsym->is_undefined())
6834 && !gsym->is_weak_undefined())
6836 gold_error(_("undefined or discarded symbol %s in GOT"),
6841 if (!gsym->is_weak_undefined())
6843 const Sized_symbol<32>* sym =
6844 static_cast<const Sized_symbol<32>*>(gsym);
6845 value = sym->value();
6851 unsigned got_offset = reloc.got_offset();
6852 gold_assert(got_offset < oview_size);
6854 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
6855 Valtype* wv = reinterpret_cast<Valtype*>(oview + got_offset);
6857 switch (reloc.r_type())
6859 case elfcpp::R_ARM_TLS_DTPOFF32:
6862 case elfcpp::R_ARM_TLS_TPOFF32:
6863 x = value + aligned_tcb_size;
6868 elfcpp::Swap<32, big_endian>::writeval(wv, x);
6871 of->write_output_view(offset, oview_size, oview);
6874 // A class to handle the PLT data.
6876 template<bool big_endian>
6877 class Output_data_plt_arm : public Output_section_data
6880 typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian>
6883 Output_data_plt_arm(Layout*, Output_data_space*);
6885 // Add an entry to the PLT.
6887 add_entry(Symbol* gsym);
6889 // Return the .rel.plt section data.
6890 const Reloc_section*
6892 { return this->rel_; }
6896 do_adjust_output_section(Output_section* os);
6898 // Write to a map file.
6900 do_print_to_mapfile(Mapfile* mapfile) const
6901 { mapfile->print_output_data(this, _("** PLT")); }
6904 // Template for the first PLT entry.
6905 static const uint32_t first_plt_entry[5];
6907 // Template for subsequent PLT entries.
6908 static const uint32_t plt_entry[3];
6910 // Set the final size.
6912 set_final_data_size()
6914 this->set_data_size(sizeof(first_plt_entry)
6915 + this->count_ * sizeof(plt_entry));
6918 // Write out the PLT data.
6920 do_write(Output_file*);
6922 // The reloc section.
6923 Reloc_section* rel_;
6924 // The .got.plt section.
6925 Output_data_space* got_plt_;
6926 // The number of PLT entries.
6927 unsigned int count_;
6930 // Create the PLT section. The ordinary .got section is an argument,
6931 // since we need to refer to the start. We also create our own .got
6932 // section just for PLT entries.
6934 template<bool big_endian>
6935 Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout,
6936 Output_data_space* got_plt)
6937 : Output_section_data(4), got_plt_(got_plt), count_(0)
6939 this->rel_ = new Reloc_section(false);
6940 layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
6941 elfcpp::SHF_ALLOC, this->rel_, true, false,
6945 template<bool big_endian>
6947 Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os)
6952 // Add an entry to the PLT.
6954 template<bool big_endian>
6956 Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym)
6958 gold_assert(!gsym->has_plt_offset());
6960 // Note that when setting the PLT offset we skip the initial
6961 // reserved PLT entry.
6962 gsym->set_plt_offset((this->count_) * sizeof(plt_entry)
6963 + sizeof(first_plt_entry));
6967 section_offset_type got_offset = this->got_plt_->current_data_size();
6969 // Every PLT entry needs a GOT entry which points back to the PLT
6970 // entry (this will be changed by the dynamic linker, normally
6971 // lazily when the function is called).
6972 this->got_plt_->set_current_data_size(got_offset + 4);
6974 // Every PLT entry needs a reloc.
6975 gsym->set_needs_dynsym_entry();
6976 this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_,
6979 // Note that we don't need to save the symbol. The contents of the
6980 // PLT are independent of which symbols are used. The symbols only
6981 // appear in the relocations.
6985 // FIXME: This is not very flexible. Right now this has only been tested
6986 // on armv5te. If we are to support additional architecture features like
6987 // Thumb-2 or BE8, we need to make this more flexible like GNU ld.
6989 // The first entry in the PLT.
6990 template<bool big_endian>
6991 const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] =
6993 0xe52de004, // str lr, [sp, #-4]!
6994 0xe59fe004, // ldr lr, [pc, #4]
6995 0xe08fe00e, // add lr, pc, lr
6996 0xe5bef008, // ldr pc, [lr, #8]!
6997 0x00000000, // &GOT[0] - .
7000 // Subsequent entries in the PLT.
7002 template<bool big_endian>
7003 const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] =
7005 0xe28fc600, // add ip, pc, #0xNN00000
7006 0xe28cca00, // add ip, ip, #0xNN000
7007 0xe5bcf000, // ldr pc, [ip, #0xNNN]!
7010 // Write out the PLT. This uses the hand-coded instructions above,
7011 // and adjusts them as needed. This is all specified by the arm ELF
7012 // Processor Supplement.
7014 template<bool big_endian>
7016 Output_data_plt_arm<big_endian>::do_write(Output_file* of)
7018 const off_t offset = this->offset();
7019 const section_size_type oview_size =
7020 convert_to_section_size_type(this->data_size());
7021 unsigned char* const oview = of->get_output_view(offset, oview_size);
7023 const off_t got_file_offset = this->got_plt_->offset();
7024 const section_size_type got_size =
7025 convert_to_section_size_type(this->got_plt_->data_size());
7026 unsigned char* const got_view = of->get_output_view(got_file_offset,
7028 unsigned char* pov = oview;
7030 Arm_address plt_address = this->address();
7031 Arm_address got_address = this->got_plt_->address();
7033 // Write first PLT entry. All but the last word are constants.
7034 const size_t num_first_plt_words = (sizeof(first_plt_entry)
7035 / sizeof(plt_entry[0]));
7036 for (size_t i = 0; i < num_first_plt_words - 1; i++)
7037 elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]);
7038 // Last word in first PLT entry is &GOT[0] - .
7039 elfcpp::Swap<32, big_endian>::writeval(pov + 16,
7040 got_address - (plt_address + 16));
7041 pov += sizeof(first_plt_entry);
7043 unsigned char* got_pov = got_view;
7045 memset(got_pov, 0, 12);
7048 const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
7049 unsigned int plt_offset = sizeof(first_plt_entry);
7050 unsigned int plt_rel_offset = 0;
7051 unsigned int got_offset = 12;
7052 const unsigned int count = this->count_;
7053 for (unsigned int i = 0;
7056 pov += sizeof(plt_entry),
7058 plt_offset += sizeof(plt_entry),
7059 plt_rel_offset += rel_size,
7062 // Set and adjust the PLT entry itself.
7063 int32_t offset = ((got_address + got_offset)
7064 - (plt_address + plt_offset + 8));
7066 gold_assert(offset >= 0 && offset < 0x0fffffff);
7067 uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff);
7068 elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0);
7069 uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff);
7070 elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1);
7071 uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff);
7072 elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2);
7074 // Set the entry in the GOT.
7075 elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address);
7078 gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
7079 gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
7081 of->write_output_view(offset, oview_size, oview);
7082 of->write_output_view(got_file_offset, got_size, got_view);
7085 // Create a PLT entry for a global symbol.
7087 template<bool big_endian>
7089 Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout,
7092 if (gsym->has_plt_offset())
7095 if (this->plt_ == NULL)
7097 // Create the GOT sections first.
7098 this->got_section(symtab, layout);
7100 this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_);
7101 layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
7103 | elfcpp::SHF_EXECINSTR),
7104 this->plt_, false, false, false, false);
7106 this->plt_->add_entry(gsym);
7109 // Get the section to use for TLS_DESC relocations.
7111 template<bool big_endian>
7112 typename Target_arm<big_endian>::Reloc_section*
7113 Target_arm<big_endian>::rel_tls_desc_section(Layout* layout) const
7115 return this->plt_section()->rel_tls_desc(layout);
7118 // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
7120 template<bool big_endian>
7122 Target_arm<big_endian>::define_tls_base_symbol(
7123 Symbol_table* symtab,
7126 if (this->tls_base_symbol_defined_)
7129 Output_segment* tls_segment = layout->tls_segment();
7130 if (tls_segment != NULL)
7132 bool is_exec = parameters->options().output_is_executable();
7133 symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
7134 Symbol_table::PREDEFINED,
7138 elfcpp::STV_HIDDEN, 0,
7140 ? Symbol::SEGMENT_END
7141 : Symbol::SEGMENT_START),
7144 this->tls_base_symbol_defined_ = true;
7147 // Create a GOT entry for the TLS module index.
7149 template<bool big_endian>
7151 Target_arm<big_endian>::got_mod_index_entry(
7152 Symbol_table* symtab,
7154 Sized_relobj<32, big_endian>* object)
7156 if (this->got_mod_index_offset_ == -1U)
7158 gold_assert(symtab != NULL && layout != NULL && object != NULL);
7159 Arm_output_data_got<big_endian>* got = this->got_section(symtab, layout);
7160 unsigned int got_offset;
7161 if (!parameters->doing_static_link())
7163 got_offset = got->add_constant(0);
7164 Reloc_section* rel_dyn = this->rel_dyn_section(layout);
7165 rel_dyn->add_local(object, 0, elfcpp::R_ARM_TLS_DTPMOD32, got,
7170 // We are doing a static link. Just mark it as belong to module 1,
7172 got_offset = got->add_constant(1);
7175 got->add_constant(0);
7176 this->got_mod_index_offset_ = got_offset;
7178 return this->got_mod_index_offset_;
7181 // Optimize the TLS relocation type based on what we know about the
7182 // symbol. IS_FINAL is true if the final address of this symbol is
7183 // known at link time.
7185 template<bool big_endian>
7186 tls::Tls_optimization
7187 Target_arm<big_endian>::optimize_tls_reloc(bool, int)
7189 // FIXME: Currently we do not do any TLS optimization.
7190 return tls::TLSOPT_NONE;
7193 // Report an unsupported relocation against a local symbol.
7195 template<bool big_endian>
7197 Target_arm<big_endian>::Scan::unsupported_reloc_local(
7198 Sized_relobj<32, big_endian>* object,
7199 unsigned int r_type)
7201 gold_error(_("%s: unsupported reloc %u against local symbol"),
7202 object->name().c_str(), r_type);
7205 // We are about to emit a dynamic relocation of type R_TYPE. If the
7206 // dynamic linker does not support it, issue an error. The GNU linker
7207 // only issues a non-PIC error for an allocated read-only section.
7208 // Here we know the section is allocated, but we don't know that it is
7209 // read-only. But we check for all the relocation types which the
7210 // glibc dynamic linker supports, so it seems appropriate to issue an
7211 // error even if the section is not read-only.
7213 template<bool big_endian>
7215 Target_arm<big_endian>::Scan::check_non_pic(Relobj* object,
7216 unsigned int r_type)
7220 // These are the relocation types supported by glibc for ARM.
7221 case elfcpp::R_ARM_RELATIVE:
7222 case elfcpp::R_ARM_COPY:
7223 case elfcpp::R_ARM_GLOB_DAT:
7224 case elfcpp::R_ARM_JUMP_SLOT:
7225 case elfcpp::R_ARM_ABS32:
7226 case elfcpp::R_ARM_ABS32_NOI:
7227 case elfcpp::R_ARM_PC24:
7228 // FIXME: The following 3 types are not supported by Android's dynamic
7230 case elfcpp::R_ARM_TLS_DTPMOD32:
7231 case elfcpp::R_ARM_TLS_DTPOFF32:
7232 case elfcpp::R_ARM_TLS_TPOFF32:
7237 // This prevents us from issuing more than one error per reloc
7238 // section. But we can still wind up issuing more than one
7239 // error per object file.
7240 if (this->issued_non_pic_error_)
7242 const Arm_reloc_property* reloc_property =
7243 arm_reloc_property_table->get_reloc_property(r_type);
7244 gold_assert(reloc_property != NULL);
7245 object->error(_("requires unsupported dynamic reloc %s; "
7246 "recompile with -fPIC"),
7247 reloc_property->name().c_str());
7248 this->issued_non_pic_error_ = true;
7252 case elfcpp::R_ARM_NONE:
7257 // Scan a relocation for a local symbol.
7258 // FIXME: This only handles a subset of relocation types used by Android
7259 // on ARM v5te devices.
7261 template<bool big_endian>
7263 Target_arm<big_endian>::Scan::local(Symbol_table* symtab,
7266 Sized_relobj<32, big_endian>* object,
7267 unsigned int data_shndx,
7268 Output_section* output_section,
7269 const elfcpp::Rel<32, big_endian>& reloc,
7270 unsigned int r_type,
7271 const elfcpp::Sym<32, big_endian>& lsym)
7273 r_type = get_real_reloc_type(r_type);
7276 case elfcpp::R_ARM_NONE:
7277 case elfcpp::R_ARM_V4BX:
7278 case elfcpp::R_ARM_GNU_VTENTRY:
7279 case elfcpp::R_ARM_GNU_VTINHERIT:
7282 case elfcpp::R_ARM_ABS32:
7283 case elfcpp::R_ARM_ABS32_NOI:
7284 // If building a shared library (or a position-independent
7285 // executable), we need to create a dynamic relocation for
7286 // this location. The relocation applied at link time will
7287 // apply the link-time value, so we flag the location with
7288 // an R_ARM_RELATIVE relocation so the dynamic loader can
7289 // relocate it easily.
7290 if (parameters->options().output_is_position_independent())
7292 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7293 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7294 // If we are to add more other reloc types than R_ARM_ABS32,
7295 // we need to add check_non_pic(object, r_type) here.
7296 rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE,
7297 output_section, data_shndx,
7298 reloc.get_r_offset());
7302 case elfcpp::R_ARM_ABS16:
7303 case elfcpp::R_ARM_ABS12:
7304 case elfcpp::R_ARM_THM_ABS5:
7305 case elfcpp::R_ARM_ABS8:
7306 case elfcpp::R_ARM_BASE_ABS:
7307 case elfcpp::R_ARM_MOVW_ABS_NC:
7308 case elfcpp::R_ARM_MOVT_ABS:
7309 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7310 case elfcpp::R_ARM_THM_MOVT_ABS:
7311 // If building a shared library (or a position-independent
7312 // executable), we need to create a dynamic relocation for
7313 // this location. Because the addend needs to remain in the
7314 // data section, we need to be careful not to apply this
7315 // relocation statically.
7316 if (parameters->options().output_is_position_independent())
7318 check_non_pic(object, r_type);
7319 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7320 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7321 if (lsym.get_st_type() != elfcpp::STT_SECTION)
7322 rel_dyn->add_local(object, r_sym, r_type, output_section,
7323 data_shndx, reloc.get_r_offset());
7326 gold_assert(lsym.get_st_value() == 0);
7327 unsigned int shndx = lsym.get_st_shndx();
7329 shndx = object->adjust_sym_shndx(r_sym, shndx,
7332 object->error(_("section symbol %u has bad shndx %u"),
7335 rel_dyn->add_local_section(object, shndx,
7336 r_type, output_section,
7337 data_shndx, reloc.get_r_offset());
7342 case elfcpp::R_ARM_PC24:
7343 case elfcpp::R_ARM_REL32:
7344 case elfcpp::R_ARM_LDR_PC_G0:
7345 case elfcpp::R_ARM_SBREL32:
7346 case elfcpp::R_ARM_THM_CALL:
7347 case elfcpp::R_ARM_THM_PC8:
7348 case elfcpp::R_ARM_BASE_PREL:
7349 case elfcpp::R_ARM_PLT32:
7350 case elfcpp::R_ARM_CALL:
7351 case elfcpp::R_ARM_JUMP24:
7352 case elfcpp::R_ARM_THM_JUMP24:
7353 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7354 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7355 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7356 case elfcpp::R_ARM_SBREL31:
7357 case elfcpp::R_ARM_PREL31:
7358 case elfcpp::R_ARM_MOVW_PREL_NC:
7359 case elfcpp::R_ARM_MOVT_PREL:
7360 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7361 case elfcpp::R_ARM_THM_MOVT_PREL:
7362 case elfcpp::R_ARM_THM_JUMP19:
7363 case elfcpp::R_ARM_THM_JUMP6:
7364 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7365 case elfcpp::R_ARM_THM_PC12:
7366 case elfcpp::R_ARM_REL32_NOI:
7367 case elfcpp::R_ARM_ALU_PC_G0_NC:
7368 case elfcpp::R_ARM_ALU_PC_G0:
7369 case elfcpp::R_ARM_ALU_PC_G1_NC:
7370 case elfcpp::R_ARM_ALU_PC_G1:
7371 case elfcpp::R_ARM_ALU_PC_G2:
7372 case elfcpp::R_ARM_LDR_PC_G1:
7373 case elfcpp::R_ARM_LDR_PC_G2:
7374 case elfcpp::R_ARM_LDRS_PC_G0:
7375 case elfcpp::R_ARM_LDRS_PC_G1:
7376 case elfcpp::R_ARM_LDRS_PC_G2:
7377 case elfcpp::R_ARM_LDC_PC_G0:
7378 case elfcpp::R_ARM_LDC_PC_G1:
7379 case elfcpp::R_ARM_LDC_PC_G2:
7380 case elfcpp::R_ARM_ALU_SB_G0_NC:
7381 case elfcpp::R_ARM_ALU_SB_G0:
7382 case elfcpp::R_ARM_ALU_SB_G1_NC:
7383 case elfcpp::R_ARM_ALU_SB_G1:
7384 case elfcpp::R_ARM_ALU_SB_G2:
7385 case elfcpp::R_ARM_LDR_SB_G0:
7386 case elfcpp::R_ARM_LDR_SB_G1:
7387 case elfcpp::R_ARM_LDR_SB_G2:
7388 case elfcpp::R_ARM_LDRS_SB_G0:
7389 case elfcpp::R_ARM_LDRS_SB_G1:
7390 case elfcpp::R_ARM_LDRS_SB_G2:
7391 case elfcpp::R_ARM_LDC_SB_G0:
7392 case elfcpp::R_ARM_LDC_SB_G1:
7393 case elfcpp::R_ARM_LDC_SB_G2:
7394 case elfcpp::R_ARM_MOVW_BREL_NC:
7395 case elfcpp::R_ARM_MOVT_BREL:
7396 case elfcpp::R_ARM_MOVW_BREL:
7397 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7398 case elfcpp::R_ARM_THM_MOVT_BREL:
7399 case elfcpp::R_ARM_THM_MOVW_BREL:
7400 case elfcpp::R_ARM_THM_JUMP11:
7401 case elfcpp::R_ARM_THM_JUMP8:
7402 // We don't need to do anything for a relative addressing relocation
7403 // against a local symbol if it does not reference the GOT.
7406 case elfcpp::R_ARM_GOTOFF32:
7407 case elfcpp::R_ARM_GOTOFF12:
7408 // We need a GOT section:
7409 target->got_section(symtab, layout);
7412 case elfcpp::R_ARM_GOT_BREL:
7413 case elfcpp::R_ARM_GOT_PREL:
7415 // The symbol requires a GOT entry.
7416 Arm_output_data_got<big_endian>* got =
7417 target->got_section(symtab, layout);
7418 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7419 if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
7421 // If we are generating a shared object, we need to add a
7422 // dynamic RELATIVE relocation for this symbol's GOT entry.
7423 if (parameters->options().output_is_position_independent())
7425 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7426 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7427 rel_dyn->add_local_relative(
7428 object, r_sym, elfcpp::R_ARM_RELATIVE, got,
7429 object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
7435 case elfcpp::R_ARM_TARGET1:
7436 case elfcpp::R_ARM_TARGET2:
7437 // This should have been mapped to another type already.
7439 case elfcpp::R_ARM_COPY:
7440 case elfcpp::R_ARM_GLOB_DAT:
7441 case elfcpp::R_ARM_JUMP_SLOT:
7442 case elfcpp::R_ARM_RELATIVE:
7443 // These are relocations which should only be seen by the
7444 // dynamic linker, and should never be seen here.
7445 gold_error(_("%s: unexpected reloc %u in object file"),
7446 object->name().c_str(), r_type);
7450 // These are initial TLS relocs, which are expected when
7452 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7453 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7454 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7455 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7456 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7458 bool output_is_shared = parameters->options().shared();
7459 const tls::Tls_optimization optimized_type
7460 = Target_arm<big_endian>::optimize_tls_reloc(!output_is_shared,
7464 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7465 if (optimized_type == tls::TLSOPT_NONE)
7467 // Create a pair of GOT entries for the module index and
7468 // dtv-relative offset.
7469 Arm_output_data_got<big_endian>* got
7470 = target->got_section(symtab, layout);
7471 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7472 unsigned int shndx = lsym.get_st_shndx();
7474 shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
7477 object->error(_("local symbol %u has bad shndx %u"),
7482 if (!parameters->doing_static_link())
7483 got->add_local_pair_with_rel(object, r_sym, shndx,
7485 target->rel_dyn_section(layout),
7486 elfcpp::R_ARM_TLS_DTPMOD32, 0);
7488 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR,
7492 // FIXME: TLS optimization not supported yet.
7496 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7497 if (optimized_type == tls::TLSOPT_NONE)
7499 // Create a GOT entry for the module index.
7500 target->got_mod_index_entry(symtab, layout, object);
7503 // FIXME: TLS optimization not supported yet.
7507 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7510 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7511 layout->set_has_static_tls();
7512 if (optimized_type == tls::TLSOPT_NONE)
7514 // Create a GOT entry for the tp-relative offset.
7515 Arm_output_data_got<big_endian>* got
7516 = target->got_section(symtab, layout);
7517 unsigned int r_sym =
7518 elfcpp::elf_r_sym<32>(reloc.get_r_info());
7519 if (!parameters->doing_static_link())
7520 got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET,
7521 target->rel_dyn_section(layout),
7522 elfcpp::R_ARM_TLS_TPOFF32);
7523 else if (!object->local_has_got_offset(r_sym,
7524 GOT_TYPE_TLS_OFFSET))
7526 got->add_local(object, r_sym, GOT_TYPE_TLS_OFFSET);
7527 unsigned int got_offset =
7528 object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET);
7529 got->add_static_reloc(got_offset,
7530 elfcpp::R_ARM_TLS_TPOFF32, object,
7535 // FIXME: TLS optimization not supported yet.
7539 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7540 layout->set_has_static_tls();
7541 if (output_is_shared)
7543 // We need to create a dynamic relocation.
7544 gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
7545 unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
7546 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7547 rel_dyn->add_local(object, r_sym, elfcpp::R_ARM_TLS_TPOFF32,
7548 output_section, data_shndx,
7549 reloc.get_r_offset());
7560 unsupported_reloc_local(object, r_type);
7565 // Report an unsupported relocation against a global symbol.
7567 template<bool big_endian>
7569 Target_arm<big_endian>::Scan::unsupported_reloc_global(
7570 Sized_relobj<32, big_endian>* object,
7571 unsigned int r_type,
7574 gold_error(_("%s: unsupported reloc %u against global symbol %s"),
7575 object->name().c_str(), r_type, gsym->demangled_name().c_str());
7578 // Scan a relocation for a global symbol.
7580 template<bool big_endian>
7582 Target_arm<big_endian>::Scan::global(Symbol_table* symtab,
7585 Sized_relobj<32, big_endian>* object,
7586 unsigned int data_shndx,
7587 Output_section* output_section,
7588 const elfcpp::Rel<32, big_endian>& reloc,
7589 unsigned int r_type,
7592 // A reference to _GLOBAL_OFFSET_TABLE_ implies that we need a got
7593 // section. We check here to avoid creating a dynamic reloc against
7594 // _GLOBAL_OFFSET_TABLE_.
7595 if (!target->has_got_section()
7596 && strcmp(gsym->name(), "_GLOBAL_OFFSET_TABLE_") == 0)
7597 target->got_section(symtab, layout);
7599 r_type = get_real_reloc_type(r_type);
7602 case elfcpp::R_ARM_NONE:
7603 case elfcpp::R_ARM_V4BX:
7604 case elfcpp::R_ARM_GNU_VTENTRY:
7605 case elfcpp::R_ARM_GNU_VTINHERIT:
7608 case elfcpp::R_ARM_ABS32:
7609 case elfcpp::R_ARM_ABS16:
7610 case elfcpp::R_ARM_ABS12:
7611 case elfcpp::R_ARM_THM_ABS5:
7612 case elfcpp::R_ARM_ABS8:
7613 case elfcpp::R_ARM_BASE_ABS:
7614 case elfcpp::R_ARM_MOVW_ABS_NC:
7615 case elfcpp::R_ARM_MOVT_ABS:
7616 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
7617 case elfcpp::R_ARM_THM_MOVT_ABS:
7618 case elfcpp::R_ARM_ABS32_NOI:
7619 // Absolute addressing relocations.
7621 // Make a PLT entry if necessary.
7622 if (this->symbol_needs_plt_entry(gsym))
7624 target->make_plt_entry(symtab, layout, gsym);
7625 // Since this is not a PC-relative relocation, we may be
7626 // taking the address of a function. In that case we need to
7627 // set the entry in the dynamic symbol table to the address of
7629 if (gsym->is_from_dynobj() && !parameters->options().shared())
7630 gsym->set_needs_dynsym_value();
7632 // Make a dynamic relocation if necessary.
7633 if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
7635 if (gsym->may_need_copy_reloc())
7637 target->copy_reloc(symtab, layout, object,
7638 data_shndx, output_section, gsym, reloc);
7640 else if ((r_type == elfcpp::R_ARM_ABS32
7641 || r_type == elfcpp::R_ARM_ABS32_NOI)
7642 && gsym->can_use_relative_reloc(false))
7644 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7645 rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE,
7646 output_section, object,
7647 data_shndx, reloc.get_r_offset());
7651 check_non_pic(object, r_type);
7652 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7653 rel_dyn->add_global(gsym, r_type, output_section, object,
7654 data_shndx, reloc.get_r_offset());
7660 case elfcpp::R_ARM_GOTOFF32:
7661 case elfcpp::R_ARM_GOTOFF12:
7662 // We need a GOT section.
7663 target->got_section(symtab, layout);
7666 case elfcpp::R_ARM_REL32:
7667 case elfcpp::R_ARM_LDR_PC_G0:
7668 case elfcpp::R_ARM_SBREL32:
7669 case elfcpp::R_ARM_THM_PC8:
7670 case elfcpp::R_ARM_BASE_PREL:
7671 case elfcpp::R_ARM_LDR_SBREL_11_0_NC:
7672 case elfcpp::R_ARM_ALU_SBREL_19_12_NC:
7673 case elfcpp::R_ARM_ALU_SBREL_27_20_CK:
7674 case elfcpp::R_ARM_MOVW_PREL_NC:
7675 case elfcpp::R_ARM_MOVT_PREL:
7676 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
7677 case elfcpp::R_ARM_THM_MOVT_PREL:
7678 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
7679 case elfcpp::R_ARM_THM_PC12:
7680 case elfcpp::R_ARM_REL32_NOI:
7681 case elfcpp::R_ARM_ALU_PC_G0_NC:
7682 case elfcpp::R_ARM_ALU_PC_G0:
7683 case elfcpp::R_ARM_ALU_PC_G1_NC:
7684 case elfcpp::R_ARM_ALU_PC_G1:
7685 case elfcpp::R_ARM_ALU_PC_G2:
7686 case elfcpp::R_ARM_LDR_PC_G1:
7687 case elfcpp::R_ARM_LDR_PC_G2:
7688 case elfcpp::R_ARM_LDRS_PC_G0:
7689 case elfcpp::R_ARM_LDRS_PC_G1:
7690 case elfcpp::R_ARM_LDRS_PC_G2:
7691 case elfcpp::R_ARM_LDC_PC_G0:
7692 case elfcpp::R_ARM_LDC_PC_G1:
7693 case elfcpp::R_ARM_LDC_PC_G2:
7694 case elfcpp::R_ARM_ALU_SB_G0_NC:
7695 case elfcpp::R_ARM_ALU_SB_G0:
7696 case elfcpp::R_ARM_ALU_SB_G1_NC:
7697 case elfcpp::R_ARM_ALU_SB_G1:
7698 case elfcpp::R_ARM_ALU_SB_G2:
7699 case elfcpp::R_ARM_LDR_SB_G0:
7700 case elfcpp::R_ARM_LDR_SB_G1:
7701 case elfcpp::R_ARM_LDR_SB_G2:
7702 case elfcpp::R_ARM_LDRS_SB_G0:
7703 case elfcpp::R_ARM_LDRS_SB_G1:
7704 case elfcpp::R_ARM_LDRS_SB_G2:
7705 case elfcpp::R_ARM_LDC_SB_G0:
7706 case elfcpp::R_ARM_LDC_SB_G1:
7707 case elfcpp::R_ARM_LDC_SB_G2:
7708 case elfcpp::R_ARM_MOVW_BREL_NC:
7709 case elfcpp::R_ARM_MOVT_BREL:
7710 case elfcpp::R_ARM_MOVW_BREL:
7711 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
7712 case elfcpp::R_ARM_THM_MOVT_BREL:
7713 case elfcpp::R_ARM_THM_MOVW_BREL:
7714 // Relative addressing relocations.
7716 // Make a dynamic relocation if necessary.
7717 int flags = Symbol::NON_PIC_REF;
7718 if (gsym->needs_dynamic_reloc(flags))
7720 if (target->may_need_copy_reloc(gsym))
7722 target->copy_reloc(symtab, layout, object,
7723 data_shndx, output_section, gsym, reloc);
7727 check_non_pic(object, r_type);
7728 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7729 rel_dyn->add_global(gsym, r_type, output_section, object,
7730 data_shndx, reloc.get_r_offset());
7736 case elfcpp::R_ARM_PC24:
7737 case elfcpp::R_ARM_THM_CALL:
7738 case elfcpp::R_ARM_PLT32:
7739 case elfcpp::R_ARM_CALL:
7740 case elfcpp::R_ARM_JUMP24:
7741 case elfcpp::R_ARM_THM_JUMP24:
7742 case elfcpp::R_ARM_SBREL31:
7743 case elfcpp::R_ARM_PREL31:
7744 case elfcpp::R_ARM_THM_JUMP19:
7745 case elfcpp::R_ARM_THM_JUMP6:
7746 case elfcpp::R_ARM_THM_JUMP11:
7747 case elfcpp::R_ARM_THM_JUMP8:
7748 // All the relocation above are branches except for the PREL31 ones.
7749 // A PREL31 relocation can point to a personality function in a shared
7750 // library. In that case we want to use a PLT because we want to
7751 // call the personality routine and the dyanmic linkers we care about
7752 // do not support dynamic PREL31 relocations. An REL31 relocation may
7753 // point to a function whose unwinding behaviour is being described but
7754 // we will not mistakenly generate a PLT for that because we should use
7755 // a local section symbol.
7757 // If the symbol is fully resolved, this is just a relative
7758 // local reloc. Otherwise we need a PLT entry.
7759 if (gsym->final_value_is_known())
7761 // If building a shared library, we can also skip the PLT entry
7762 // if the symbol is defined in the output file and is protected
7764 if (gsym->is_defined()
7765 && !gsym->is_from_dynobj()
7766 && !gsym->is_preemptible())
7768 target->make_plt_entry(symtab, layout, gsym);
7771 case elfcpp::R_ARM_GOT_BREL:
7772 case elfcpp::R_ARM_GOT_ABS:
7773 case elfcpp::R_ARM_GOT_PREL:
7775 // The symbol requires a GOT entry.
7776 Arm_output_data_got<big_endian>* got =
7777 target->got_section(symtab, layout);
7778 if (gsym->final_value_is_known())
7779 got->add_global(gsym, GOT_TYPE_STANDARD);
7782 // If this symbol is not fully resolved, we need to add a
7783 // GOT entry with a dynamic relocation.
7784 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7785 if (gsym->is_from_dynobj()
7786 || gsym->is_undefined()
7787 || gsym->is_preemptible())
7788 got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
7789 rel_dyn, elfcpp::R_ARM_GLOB_DAT);
7792 if (got->add_global(gsym, GOT_TYPE_STANDARD))
7793 rel_dyn->add_global_relative(
7794 gsym, elfcpp::R_ARM_RELATIVE, got,
7795 gsym->got_offset(GOT_TYPE_STANDARD));
7801 case elfcpp::R_ARM_TARGET1:
7802 case elfcpp::R_ARM_TARGET2:
7803 // These should have been mapped to other types already.
7805 case elfcpp::R_ARM_COPY:
7806 case elfcpp::R_ARM_GLOB_DAT:
7807 case elfcpp::R_ARM_JUMP_SLOT:
7808 case elfcpp::R_ARM_RELATIVE:
7809 // These are relocations which should only be seen by the
7810 // dynamic linker, and should never be seen here.
7811 gold_error(_("%s: unexpected reloc %u in object file"),
7812 object->name().c_str(), r_type);
7815 // These are initial tls relocs, which are expected when
7817 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7818 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7819 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7820 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7821 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7823 const bool is_final = gsym->final_value_is_known();
7824 const tls::Tls_optimization optimized_type
7825 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
7828 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
7829 if (optimized_type == tls::TLSOPT_NONE)
7831 // Create a pair of GOT entries for the module index and
7832 // dtv-relative offset.
7833 Arm_output_data_got<big_endian>* got
7834 = target->got_section(symtab, layout);
7835 if (!parameters->doing_static_link())
7836 got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
7837 target->rel_dyn_section(layout),
7838 elfcpp::R_ARM_TLS_DTPMOD32,
7839 elfcpp::R_ARM_TLS_DTPOFF32);
7841 got->add_tls_gd32_with_static_reloc(GOT_TYPE_TLS_PAIR, gsym);
7844 // FIXME: TLS optimization not supported yet.
7848 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
7849 if (optimized_type == tls::TLSOPT_NONE)
7851 // Create a GOT entry for the module index.
7852 target->got_mod_index_entry(symtab, layout, object);
7855 // FIXME: TLS optimization not supported yet.
7859 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
7862 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
7863 layout->set_has_static_tls();
7864 if (optimized_type == tls::TLSOPT_NONE)
7866 // Create a GOT entry for the tp-relative offset.
7867 Arm_output_data_got<big_endian>* got
7868 = target->got_section(symtab, layout);
7869 if (!parameters->doing_static_link())
7870 got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET,
7871 target->rel_dyn_section(layout),
7872 elfcpp::R_ARM_TLS_TPOFF32);
7873 else if (!gsym->has_got_offset(GOT_TYPE_TLS_OFFSET))
7875 got->add_global(gsym, GOT_TYPE_TLS_OFFSET);
7876 unsigned int got_offset =
7877 gsym->got_offset(GOT_TYPE_TLS_OFFSET);
7878 got->add_static_reloc(got_offset,
7879 elfcpp::R_ARM_TLS_TPOFF32, gsym);
7883 // FIXME: TLS optimization not supported yet.
7887 case elfcpp::R_ARM_TLS_LE32: // Local-exec
7888 layout->set_has_static_tls();
7889 if (parameters->options().shared())
7891 // We need to create a dynamic relocation.
7892 Reloc_section* rel_dyn = target->rel_dyn_section(layout);
7893 rel_dyn->add_global(gsym, elfcpp::R_ARM_TLS_TPOFF32,
7894 output_section, object,
7895 data_shndx, reloc.get_r_offset());
7906 unsupported_reloc_global(object, r_type, gsym);
7911 // Process relocations for gc.
7913 template<bool big_endian>
7915 Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab,
7917 Sized_relobj<32, big_endian>* object,
7918 unsigned int data_shndx,
7920 const unsigned char* prelocs,
7922 Output_section* output_section,
7923 bool needs_special_offset_handling,
7924 size_t local_symbol_count,
7925 const unsigned char* plocal_symbols)
7927 typedef Target_arm<big_endian> Arm;
7928 typedef typename Target_arm<big_endian>::Scan Scan;
7930 gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>(
7939 needs_special_offset_handling,
7944 // Scan relocations for a section.
7946 template<bool big_endian>
7948 Target_arm<big_endian>::scan_relocs(Symbol_table* symtab,
7950 Sized_relobj<32, big_endian>* object,
7951 unsigned int data_shndx,
7952 unsigned int sh_type,
7953 const unsigned char* prelocs,
7955 Output_section* output_section,
7956 bool needs_special_offset_handling,
7957 size_t local_symbol_count,
7958 const unsigned char* plocal_symbols)
7960 typedef typename Target_arm<big_endian>::Scan Scan;
7961 if (sh_type == elfcpp::SHT_RELA)
7963 gold_error(_("%s: unsupported RELA reloc section"),
7964 object->name().c_str());
7968 gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>(
7977 needs_special_offset_handling,
7982 // Finalize the sections.
7984 template<bool big_endian>
7986 Target_arm<big_endian>::do_finalize_sections(
7988 const Input_objects* input_objects,
7989 Symbol_table* symtab)
7991 // Create an empty uninitialized attribute section if we still don't have it
7993 if (this->attributes_section_data_ == NULL)
7994 this->attributes_section_data_ = new Attributes_section_data(NULL, 0);
7996 // Merge processor-specific flags.
7997 for (Input_objects::Relobj_iterator p = input_objects->relobj_begin();
7998 p != input_objects->relobj_end();
8001 Arm_relobj<big_endian>* arm_relobj =
8002 Arm_relobj<big_endian>::as_arm_relobj(*p);
8003 if (arm_relobj->merge_flags_and_attributes())
8005 this->merge_processor_specific_flags(
8007 arm_relobj->processor_specific_flags());
8008 this->merge_object_attributes(arm_relobj->name().c_str(),
8009 arm_relobj->attributes_section_data());
8013 for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin();
8014 p != input_objects->dynobj_end();
8017 Arm_dynobj<big_endian>* arm_dynobj =
8018 Arm_dynobj<big_endian>::as_arm_dynobj(*p);
8019 this->merge_processor_specific_flags(
8021 arm_dynobj->processor_specific_flags());
8022 this->merge_object_attributes(arm_dynobj->name().c_str(),
8023 arm_dynobj->attributes_section_data());
8027 const Object_attribute* cpu_arch_attr =
8028 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch);
8029 if (cpu_arch_attr->int_value() > elfcpp::TAG_CPU_ARCH_V4)
8030 this->set_may_use_blx(true);
8032 // Check if we need to use Cortex-A8 workaround.
8033 if (parameters->options().user_set_fix_cortex_a8())
8034 this->fix_cortex_a8_ = parameters->options().fix_cortex_a8();
8037 // If neither --fix-cortex-a8 nor --no-fix-cortex-a8 is used, turn on
8038 // Cortex-A8 erratum workaround for ARMv7-A or ARMv7 with unknown
8040 const Object_attribute* cpu_arch_profile_attr =
8041 this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile);
8042 this->fix_cortex_a8_ =
8043 (cpu_arch_attr->int_value() == elfcpp::TAG_CPU_ARCH_V7
8044 && (cpu_arch_profile_attr->int_value() == 'A'
8045 || cpu_arch_profile_attr->int_value() == 0));
8048 // Check if we can use V4BX interworking.
8049 // The V4BX interworking stub contains BX instruction,
8050 // which is not specified for some profiles.
8051 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING
8052 && !this->may_use_blx())
8053 gold_error(_("unable to provide V4BX reloc interworking fix up; "
8054 "the target profile does not support BX instruction"));
8056 // Fill in some more dynamic tags.
8057 const Reloc_section* rel_plt = (this->plt_ == NULL
8059 : this->plt_->rel_plt());
8060 layout->add_target_dynamic_tags(true, this->got_plt_, rel_plt,
8061 this->rel_dyn_, true, false);
8063 // Emit any relocs we saved in an attempt to avoid generating COPY
8065 if (this->copy_relocs_.any_saved_relocs())
8066 this->copy_relocs_.emit(this->rel_dyn_section(layout));
8068 // Handle the .ARM.exidx section.
8069 Output_section* exidx_section = layout->find_output_section(".ARM.exidx");
8070 if (exidx_section != NULL
8071 && exidx_section->type() == elfcpp::SHT_ARM_EXIDX
8072 && !parameters->options().relocatable())
8074 // Create __exidx_start and __exdix_end symbols.
8075 symtab->define_in_output_data("__exidx_start", NULL,
8076 Symbol_table::PREDEFINED,
8077 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8078 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8080 symtab->define_in_output_data("__exidx_end", NULL,
8081 Symbol_table::PREDEFINED,
8082 exidx_section, 0, 0, elfcpp::STT_OBJECT,
8083 elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0,
8086 // For the ARM target, we need to add a PT_ARM_EXIDX segment for
8087 // the .ARM.exidx section.
8088 if (!layout->script_options()->saw_phdrs_clause())
8090 gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0, 0)
8092 Output_segment* exidx_segment =
8093 layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R);
8094 exidx_segment->add_output_section(exidx_section, elfcpp::PF_R,
8099 // Create an .ARM.attributes section unless we have no regular input
8100 // object. In that case the output will be empty.
8101 if (input_objects->number_of_relobjs() != 0)
8103 Output_attributes_section_data* attributes_section =
8104 new Output_attributes_section_data(*this->attributes_section_data_);
8105 layout->add_output_section_data(".ARM.attributes",
8106 elfcpp::SHT_ARM_ATTRIBUTES, 0,
8107 attributes_section, false, false, false,
8112 // Return whether a direct absolute static relocation needs to be applied.
8113 // In cases where Scan::local() or Scan::global() has created
8114 // a dynamic relocation other than R_ARM_RELATIVE, the addend
8115 // of the relocation is carried in the data, and we must not
8116 // apply the static relocation.
8118 template<bool big_endian>
8120 Target_arm<big_endian>::Relocate::should_apply_static_reloc(
8121 const Sized_symbol<32>* gsym,
8124 Output_section* output_section)
8126 // If the output section is not allocated, then we didn't call
8127 // scan_relocs, we didn't create a dynamic reloc, and we must apply
8129 if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
8132 // For local symbols, we will have created a non-RELATIVE dynamic
8133 // relocation only if (a) the output is position independent,
8134 // (b) the relocation is absolute (not pc- or segment-relative), and
8135 // (c) the relocation is not 32 bits wide.
8137 return !(parameters->options().output_is_position_independent()
8138 && (ref_flags & Symbol::ABSOLUTE_REF)
8141 // For global symbols, we use the same helper routines used in the
8142 // scan pass. If we did not create a dynamic relocation, or if we
8143 // created a RELATIVE dynamic relocation, we should apply the static
8145 bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
8146 bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
8147 && gsym->can_use_relative_reloc(ref_flags
8148 & Symbol::FUNCTION_CALL);
8149 return !has_dyn || is_rel;
8152 // Perform a relocation.
8154 template<bool big_endian>
8156 Target_arm<big_endian>::Relocate::relocate(
8157 const Relocate_info<32, big_endian>* relinfo,
8159 Output_section *output_section,
8161 const elfcpp::Rel<32, big_endian>& rel,
8162 unsigned int r_type,
8163 const Sized_symbol<32>* gsym,
8164 const Symbol_value<32>* psymval,
8165 unsigned char* view,
8166 Arm_address address,
8167 section_size_type view_size)
8169 typedef Arm_relocate_functions<big_endian> Arm_relocate_functions;
8171 r_type = get_real_reloc_type(r_type);
8172 const Arm_reloc_property* reloc_property =
8173 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8174 if (reloc_property == NULL)
8176 std::string reloc_name =
8177 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8178 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8179 _("cannot relocate %s in object file"),
8180 reloc_name.c_str());
8184 const Arm_relobj<big_endian>* object =
8185 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
8187 // If the final branch target of a relocation is THUMB instruction, this
8188 // is 1. Otherwise it is 0.
8189 Arm_address thumb_bit = 0;
8190 Symbol_value<32> symval;
8191 bool is_weakly_undefined_without_plt = false;
8192 if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs)
8196 // This is a global symbol. Determine if we use PLT and if the
8197 // final target is THUMB.
8198 if (gsym->use_plt_offset(reloc_is_non_pic(r_type)))
8200 // This uses a PLT, change the symbol value.
8201 symval.set_output_value(target->plt_section()->address()
8202 + gsym->plt_offset());
8205 else if (gsym->is_weak_undefined())
8207 // This is a weakly undefined symbol and we do not use PLT
8208 // for this relocation. A branch targeting this symbol will
8209 // be converted into an NOP.
8210 is_weakly_undefined_without_plt = true;
8214 // Set thumb bit if symbol:
8215 // -Has type STT_ARM_TFUNC or
8216 // -Has type STT_FUNC, is defined and with LSB in value set.
8218 (((gsym->type() == elfcpp::STT_ARM_TFUNC)
8219 || (gsym->type() == elfcpp::STT_FUNC
8220 && !gsym->is_undefined()
8221 && ((psymval->value(object, 0) & 1) != 0)))
8228 // This is a local symbol. Determine if the final target is THUMB.
8229 // We saved this information when all the local symbols were read.
8230 elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info();
8231 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
8232 thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0;
8237 // This is a fake relocation synthesized for a stub. It does not have
8238 // a real symbol. We just look at the LSB of the symbol value to
8239 // determine if the target is THUMB or not.
8240 thumb_bit = ((psymval->value(object, 0) & 1) != 0);
8243 // Strip LSB if this points to a THUMB target.
8245 && reloc_property->uses_thumb_bit()
8246 && ((psymval->value(object, 0) & 1) != 0))
8248 Arm_address stripped_value =
8249 psymval->value(object, 0) & ~static_cast<Arm_address>(1);
8250 symval.set_output_value(stripped_value);
8254 // Get the GOT offset if needed.
8255 // The GOT pointer points to the end of the GOT section.
8256 // We need to subtract the size of the GOT section to get
8257 // the actual offset to use in the relocation.
8258 bool have_got_offset = false;
8259 unsigned int got_offset = 0;
8262 case elfcpp::R_ARM_GOT_BREL:
8263 case elfcpp::R_ARM_GOT_PREL:
8266 gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
8267 got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
8268 - target->got_size());
8272 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8273 gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
8274 got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
8275 - target->got_size());
8277 have_got_offset = true;
8284 // To look up relocation stubs, we need to pass the symbol table index of
8286 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8288 // Get the addressing origin of the output segment defining the
8289 // symbol gsym if needed (AAELF 4.6.1.2 Relocation types).
8290 Arm_address sym_origin = 0;
8291 if (reloc_property->uses_symbol_base())
8293 if (r_type == elfcpp::R_ARM_BASE_ABS && gsym == NULL)
8294 // R_ARM_BASE_ABS with the NULL symbol will give the
8295 // absolute address of the GOT origin (GOT_ORG) (see ARM IHI
8296 // 0044C (AAELF): 4.6.1.8 Proxy generating relocations).
8297 sym_origin = target->got_plt_section()->address();
8298 else if (gsym == NULL)
8300 else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT)
8301 sym_origin = gsym->output_segment()->vaddr();
8302 else if (gsym->source() == Symbol::IN_OUTPUT_DATA)
8303 sym_origin = gsym->output_data()->address();
8305 // TODO: Assumes the segment base to be zero for the global symbols
8306 // till the proper support for the segment-base-relative addressing
8307 // will be implemented. This is consistent with GNU ld.
8310 // For relative addressing relocation, find out the relative address base.
8311 Arm_address relative_address_base = 0;
8312 switch(reloc_property->relative_address_base())
8314 case Arm_reloc_property::RAB_NONE:
8315 // Relocations with relative address bases RAB_TLS and RAB_tp are
8316 // handled by relocate_tls. So we do not need to do anything here.
8317 case Arm_reloc_property::RAB_TLS:
8318 case Arm_reloc_property::RAB_tp:
8320 case Arm_reloc_property::RAB_B_S:
8321 relative_address_base = sym_origin;
8323 case Arm_reloc_property::RAB_GOT_ORG:
8324 relative_address_base = target->got_plt_section()->address();
8326 case Arm_reloc_property::RAB_P:
8327 relative_address_base = address;
8329 case Arm_reloc_property::RAB_Pa:
8330 relative_address_base = address & 0xfffffffcU;
8336 typename Arm_relocate_functions::Status reloc_status =
8337 Arm_relocate_functions::STATUS_OKAY;
8338 bool check_overflow = reloc_property->checks_overflow();
8341 case elfcpp::R_ARM_NONE:
8344 case elfcpp::R_ARM_ABS8:
8345 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8347 reloc_status = Arm_relocate_functions::abs8(view, object, psymval);
8350 case elfcpp::R_ARM_ABS12:
8351 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8353 reloc_status = Arm_relocate_functions::abs12(view, object, psymval);
8356 case elfcpp::R_ARM_ABS16:
8357 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8359 reloc_status = Arm_relocate_functions::abs16(view, object, psymval);
8362 case elfcpp::R_ARM_ABS32:
8363 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8365 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8369 case elfcpp::R_ARM_ABS32_NOI:
8370 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
8372 // No thumb bit for this relocation: (S + A)
8373 reloc_status = Arm_relocate_functions::abs32(view, object, psymval,
8377 case elfcpp::R_ARM_MOVW_ABS_NC:
8378 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8380 reloc_status = Arm_relocate_functions::movw(view, object, psymval,
8385 case elfcpp::R_ARM_MOVT_ABS:
8386 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8388 reloc_status = Arm_relocate_functions::movt(view, object, psymval, 0);
8391 case elfcpp::R_ARM_THM_MOVW_ABS_NC:
8392 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8394 reloc_status = Arm_relocate_functions::thm_movw(view, object, psymval,
8395 0, thumb_bit, false);
8398 case elfcpp::R_ARM_THM_MOVT_ABS:
8399 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8401 reloc_status = Arm_relocate_functions::thm_movt(view, object,
8405 case elfcpp::R_ARM_MOVW_PREL_NC:
8406 case elfcpp::R_ARM_MOVW_BREL_NC:
8407 case elfcpp::R_ARM_MOVW_BREL:
8409 Arm_relocate_functions::movw(view, object, psymval,
8410 relative_address_base, thumb_bit,
8414 case elfcpp::R_ARM_MOVT_PREL:
8415 case elfcpp::R_ARM_MOVT_BREL:
8417 Arm_relocate_functions::movt(view, object, psymval,
8418 relative_address_base);
8421 case elfcpp::R_ARM_THM_MOVW_PREL_NC:
8422 case elfcpp::R_ARM_THM_MOVW_BREL_NC:
8423 case elfcpp::R_ARM_THM_MOVW_BREL:
8425 Arm_relocate_functions::thm_movw(view, object, psymval,
8426 relative_address_base,
8427 thumb_bit, check_overflow);
8430 case elfcpp::R_ARM_THM_MOVT_PREL:
8431 case elfcpp::R_ARM_THM_MOVT_BREL:
8433 Arm_relocate_functions::thm_movt(view, object, psymval,
8434 relative_address_base);
8437 case elfcpp::R_ARM_REL32:
8438 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8439 address, thumb_bit);
8442 case elfcpp::R_ARM_THM_ABS5:
8443 if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8445 reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval);
8448 // Thumb long branches.
8449 case elfcpp::R_ARM_THM_CALL:
8450 case elfcpp::R_ARM_THM_XPC22:
8451 case elfcpp::R_ARM_THM_JUMP24:
8453 Arm_relocate_functions::thumb_branch_common(
8454 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8455 thumb_bit, is_weakly_undefined_without_plt);
8458 case elfcpp::R_ARM_GOTOFF32:
8460 Arm_address got_origin;
8461 got_origin = target->got_plt_section()->address();
8462 reloc_status = Arm_relocate_functions::rel32(view, object, psymval,
8463 got_origin, thumb_bit);
8467 case elfcpp::R_ARM_BASE_PREL:
8468 gold_assert(gsym != NULL);
8470 Arm_relocate_functions::base_prel(view, sym_origin, address);
8473 case elfcpp::R_ARM_BASE_ABS:
8475 if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
8479 reloc_status = Arm_relocate_functions::base_abs(view, sym_origin);
8483 case elfcpp::R_ARM_GOT_BREL:
8484 gold_assert(have_got_offset);
8485 reloc_status = Arm_relocate_functions::got_brel(view, got_offset);
8488 case elfcpp::R_ARM_GOT_PREL:
8489 gold_assert(have_got_offset);
8490 // Get the address origin for GOT PLT, which is allocated right
8491 // after the GOT section, to calculate an absolute address of
8492 // the symbol GOT entry (got_origin + got_offset).
8493 Arm_address got_origin;
8494 got_origin = target->got_plt_section()->address();
8495 reloc_status = Arm_relocate_functions::got_prel(view,
8496 got_origin + got_offset,
8500 case elfcpp::R_ARM_PLT32:
8501 case elfcpp::R_ARM_CALL:
8502 case elfcpp::R_ARM_JUMP24:
8503 case elfcpp::R_ARM_XPC25:
8504 gold_assert(gsym == NULL
8505 || gsym->has_plt_offset()
8506 || gsym->final_value_is_known()
8507 || (gsym->is_defined()
8508 && !gsym->is_from_dynobj()
8509 && !gsym->is_preemptible()));
8511 Arm_relocate_functions::arm_branch_common(
8512 r_type, relinfo, view, gsym, object, r_sym, psymval, address,
8513 thumb_bit, is_weakly_undefined_without_plt);
8516 case elfcpp::R_ARM_THM_JUMP19:
8518 Arm_relocate_functions::thm_jump19(view, object, psymval, address,
8522 case elfcpp::R_ARM_THM_JUMP6:
8524 Arm_relocate_functions::thm_jump6(view, object, psymval, address);
8527 case elfcpp::R_ARM_THM_JUMP8:
8529 Arm_relocate_functions::thm_jump8(view, object, psymval, address);
8532 case elfcpp::R_ARM_THM_JUMP11:
8534 Arm_relocate_functions::thm_jump11(view, object, psymval, address);
8537 case elfcpp::R_ARM_PREL31:
8538 reloc_status = Arm_relocate_functions::prel31(view, object, psymval,
8539 address, thumb_bit);
8542 case elfcpp::R_ARM_V4BX:
8543 if (target->fix_v4bx() > General_options::FIX_V4BX_NONE)
8545 const bool is_v4bx_interworking =
8546 (target->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING);
8548 Arm_relocate_functions::v4bx(relinfo, view, object, address,
8549 is_v4bx_interworking);
8553 case elfcpp::R_ARM_THM_PC8:
8555 Arm_relocate_functions::thm_pc8(view, object, psymval, address);
8558 case elfcpp::R_ARM_THM_PC12:
8560 Arm_relocate_functions::thm_pc12(view, object, psymval, address);
8563 case elfcpp::R_ARM_THM_ALU_PREL_11_0:
8565 Arm_relocate_functions::thm_alu11(view, object, psymval, address,
8569 case elfcpp::R_ARM_ALU_PC_G0_NC:
8570 case elfcpp::R_ARM_ALU_PC_G0:
8571 case elfcpp::R_ARM_ALU_PC_G1_NC:
8572 case elfcpp::R_ARM_ALU_PC_G1:
8573 case elfcpp::R_ARM_ALU_PC_G2:
8574 case elfcpp::R_ARM_ALU_SB_G0_NC:
8575 case elfcpp::R_ARM_ALU_SB_G0:
8576 case elfcpp::R_ARM_ALU_SB_G1_NC:
8577 case elfcpp::R_ARM_ALU_SB_G1:
8578 case elfcpp::R_ARM_ALU_SB_G2:
8580 Arm_relocate_functions::arm_grp_alu(view, object, psymval,
8581 reloc_property->group_index(),
8582 relative_address_base,
8583 thumb_bit, check_overflow);
8586 case elfcpp::R_ARM_LDR_PC_G0:
8587 case elfcpp::R_ARM_LDR_PC_G1:
8588 case elfcpp::R_ARM_LDR_PC_G2:
8589 case elfcpp::R_ARM_LDR_SB_G0:
8590 case elfcpp::R_ARM_LDR_SB_G1:
8591 case elfcpp::R_ARM_LDR_SB_G2:
8593 Arm_relocate_functions::arm_grp_ldr(view, object, psymval,
8594 reloc_property->group_index(),
8595 relative_address_base);
8598 case elfcpp::R_ARM_LDRS_PC_G0:
8599 case elfcpp::R_ARM_LDRS_PC_G1:
8600 case elfcpp::R_ARM_LDRS_PC_G2:
8601 case elfcpp::R_ARM_LDRS_SB_G0:
8602 case elfcpp::R_ARM_LDRS_SB_G1:
8603 case elfcpp::R_ARM_LDRS_SB_G2:
8605 Arm_relocate_functions::arm_grp_ldrs(view, object, psymval,
8606 reloc_property->group_index(),
8607 relative_address_base);
8610 case elfcpp::R_ARM_LDC_PC_G0:
8611 case elfcpp::R_ARM_LDC_PC_G1:
8612 case elfcpp::R_ARM_LDC_PC_G2:
8613 case elfcpp::R_ARM_LDC_SB_G0:
8614 case elfcpp::R_ARM_LDC_SB_G1:
8615 case elfcpp::R_ARM_LDC_SB_G2:
8617 Arm_relocate_functions::arm_grp_ldc(view, object, psymval,
8618 reloc_property->group_index(),
8619 relative_address_base);
8622 // These are initial tls relocs, which are expected when
8624 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8625 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8626 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8627 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8628 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8630 this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
8631 view, address, view_size);
8638 // Report any errors.
8639 switch (reloc_status)
8641 case Arm_relocate_functions::STATUS_OKAY:
8643 case Arm_relocate_functions::STATUS_OVERFLOW:
8644 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8645 _("relocation overflow in %s"),
8646 reloc_property->name().c_str());
8648 case Arm_relocate_functions::STATUS_BAD_RELOC:
8649 gold_error_at_location(
8653 _("unexpected opcode while processing relocation %s"),
8654 reloc_property->name().c_str());
8663 // Perform a TLS relocation.
8665 template<bool big_endian>
8666 inline typename Arm_relocate_functions<big_endian>::Status
8667 Target_arm<big_endian>::Relocate::relocate_tls(
8668 const Relocate_info<32, big_endian>* relinfo,
8669 Target_arm<big_endian>* target,
8671 const elfcpp::Rel<32, big_endian>& rel,
8672 unsigned int r_type,
8673 const Sized_symbol<32>* gsym,
8674 const Symbol_value<32>* psymval,
8675 unsigned char* view,
8676 elfcpp::Elf_types<32>::Elf_Addr address,
8677 section_size_type /*view_size*/ )
8679 typedef Arm_relocate_functions<big_endian> ArmRelocFuncs;
8680 typedef Relocate_functions<32, big_endian> RelocFuncs;
8681 Output_segment* tls_segment = relinfo->layout->tls_segment();
8683 const Sized_relobj<32, big_endian>* object = relinfo->object;
8685 elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
8687 const bool is_final = (gsym == NULL
8688 ? !parameters->options().shared()
8689 : gsym->final_value_is_known());
8690 const tls::Tls_optimization optimized_type
8691 = Target_arm<big_endian>::optimize_tls_reloc(is_final, r_type);
8694 case elfcpp::R_ARM_TLS_GD32: // Global-dynamic
8696 unsigned int got_type = GOT_TYPE_TLS_PAIR;
8697 unsigned int got_offset;
8700 gold_assert(gsym->has_got_offset(got_type));
8701 got_offset = gsym->got_offset(got_type) - target->got_size();
8705 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8706 gold_assert(object->local_has_got_offset(r_sym, got_type));
8707 got_offset = (object->local_got_offset(r_sym, got_type)
8708 - target->got_size());
8710 if (optimized_type == tls::TLSOPT_NONE)
8712 Arm_address got_entry =
8713 target->got_plt_section()->address() + got_offset;
8715 // Relocate the field with the PC relative offset of the pair of
8717 RelocFuncs::pcrel32(view, got_entry, address);
8718 return ArmRelocFuncs::STATUS_OKAY;
8723 case elfcpp::R_ARM_TLS_LDM32: // Local-dynamic
8724 if (optimized_type == tls::TLSOPT_NONE)
8726 // Relocate the field with the offset of the GOT entry for
8727 // the module index.
8728 unsigned int got_offset;
8729 got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
8730 - target->got_size());
8731 Arm_address got_entry =
8732 target->got_plt_section()->address() + got_offset;
8734 // Relocate the field with the PC relative offset of the pair of
8736 RelocFuncs::pcrel32(view, got_entry, address);
8737 return ArmRelocFuncs::STATUS_OKAY;
8741 case elfcpp::R_ARM_TLS_LDO32: // Alternate local-dynamic
8742 RelocFuncs::rel32(view, value);
8743 return ArmRelocFuncs::STATUS_OKAY;
8745 case elfcpp::R_ARM_TLS_IE32: // Initial-exec
8746 if (optimized_type == tls::TLSOPT_NONE)
8748 // Relocate the field with the offset of the GOT entry for
8749 // the tp-relative offset of the symbol.
8750 unsigned int got_type = GOT_TYPE_TLS_OFFSET;
8751 unsigned int got_offset;
8754 gold_assert(gsym->has_got_offset(got_type));
8755 got_offset = gsym->got_offset(got_type);
8759 unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
8760 gold_assert(object->local_has_got_offset(r_sym, got_type));
8761 got_offset = object->local_got_offset(r_sym, got_type);
8764 // All GOT offsets are relative to the end of the GOT.
8765 got_offset -= target->got_size();
8767 Arm_address got_entry =
8768 target->got_plt_section()->address() + got_offset;
8770 // Relocate the field with the PC relative offset of the GOT entry.
8771 RelocFuncs::pcrel32(view, got_entry, address);
8772 return ArmRelocFuncs::STATUS_OKAY;
8776 case elfcpp::R_ARM_TLS_LE32: // Local-exec
8777 // If we're creating a shared library, a dynamic relocation will
8778 // have been created for this location, so do not apply it now.
8779 if (!parameters->options().shared())
8781 gold_assert(tls_segment != NULL);
8783 // $tp points to the TCB, which is followed by the TLS, so we
8784 // need to add TCB size to the offset.
8785 Arm_address aligned_tcb_size =
8786 align_address(ARM_TCB_SIZE, tls_segment->maximum_alignment());
8787 RelocFuncs::rel32(view, value + aligned_tcb_size);
8790 return ArmRelocFuncs::STATUS_OKAY;
8796 gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
8797 _("unsupported reloc %u"),
8799 return ArmRelocFuncs::STATUS_BAD_RELOC;
8802 // Relocate section data.
8804 template<bool big_endian>
8806 Target_arm<big_endian>::relocate_section(
8807 const Relocate_info<32, big_endian>* relinfo,
8808 unsigned int sh_type,
8809 const unsigned char* prelocs,
8811 Output_section* output_section,
8812 bool needs_special_offset_handling,
8813 unsigned char* view,
8814 Arm_address address,
8815 section_size_type view_size,
8816 const Reloc_symbol_changes* reloc_symbol_changes)
8818 typedef typename Target_arm<big_endian>::Relocate Arm_relocate;
8819 gold_assert(sh_type == elfcpp::SHT_REL);
8821 // See if we are relocating a relaxed input section. If so, the view
8822 // covers the whole output section and we need to adjust accordingly.
8823 if (needs_special_offset_handling)
8825 const Output_relaxed_input_section* poris =
8826 output_section->find_relaxed_input_section(relinfo->object,
8827 relinfo->data_shndx);
8830 Arm_address section_address = poris->address();
8831 section_size_type section_size = poris->data_size();
8833 gold_assert((section_address >= address)
8834 && ((section_address + section_size)
8835 <= (address + view_size)));
8837 off_t offset = section_address - address;
8840 view_size = section_size;
8844 gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL,
8851 needs_special_offset_handling,
8855 reloc_symbol_changes);
8858 // Return the size of a relocation while scanning during a relocatable
8861 template<bool big_endian>
8863 Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc(
8864 unsigned int r_type,
8867 r_type = get_real_reloc_type(r_type);
8868 const Arm_reloc_property* arp =
8869 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
8874 std::string reloc_name =
8875 arm_reloc_property_table->reloc_name_in_error_message(r_type);
8876 gold_error(_("%s: unexpected %s in object file"),
8877 object->name().c_str(), reloc_name.c_str());
8882 // Scan the relocs during a relocatable link.
8884 template<bool big_endian>
8886 Target_arm<big_endian>::scan_relocatable_relocs(
8887 Symbol_table* symtab,
8889 Sized_relobj<32, big_endian>* object,
8890 unsigned int data_shndx,
8891 unsigned int sh_type,
8892 const unsigned char* prelocs,
8894 Output_section* output_section,
8895 bool needs_special_offset_handling,
8896 size_t local_symbol_count,
8897 const unsigned char* plocal_symbols,
8898 Relocatable_relocs* rr)
8900 gold_assert(sh_type == elfcpp::SHT_REL);
8902 typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
8903 Relocatable_size_for_reloc> Scan_relocatable_relocs;
8905 gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL,
8906 Scan_relocatable_relocs>(
8914 needs_special_offset_handling,
8920 // Relocate a section during a relocatable link.
8922 template<bool big_endian>
8924 Target_arm<big_endian>::relocate_for_relocatable(
8925 const Relocate_info<32, big_endian>* relinfo,
8926 unsigned int sh_type,
8927 const unsigned char* prelocs,
8929 Output_section* output_section,
8930 off_t offset_in_output_section,
8931 const Relocatable_relocs* rr,
8932 unsigned char* view,
8933 Arm_address view_address,
8934 section_size_type view_size,
8935 unsigned char* reloc_view,
8936 section_size_type reloc_view_size)
8938 gold_assert(sh_type == elfcpp::SHT_REL);
8940 gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>(
8945 offset_in_output_section,
8954 // Return the value to use for a dynamic symbol which requires special
8955 // treatment. This is how we support equality comparisons of function
8956 // pointers across shared library boundaries, as described in the
8957 // processor specific ABI supplement.
8959 template<bool big_endian>
8961 Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const
8963 gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
8964 return this->plt_section()->address() + gsym->plt_offset();
8967 // Map platform-specific relocs to real relocs
8969 template<bool big_endian>
8971 Target_arm<big_endian>::get_real_reloc_type (unsigned int r_type)
8975 case elfcpp::R_ARM_TARGET1:
8976 // This is either R_ARM_ABS32 or R_ARM_REL32;
8977 return elfcpp::R_ARM_ABS32;
8979 case elfcpp::R_ARM_TARGET2:
8980 // This can be any reloc type but ususally is R_ARM_GOT_PREL
8981 return elfcpp::R_ARM_GOT_PREL;
8988 // Whether if two EABI versions V1 and V2 are compatible.
8990 template<bool big_endian>
8992 Target_arm<big_endian>::are_eabi_versions_compatible(
8993 elfcpp::Elf_Word v1,
8994 elfcpp::Elf_Word v2)
8996 // v4 and v5 are the same spec before and after it was released,
8997 // so allow mixing them.
8998 if ((v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5)
8999 || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4))
9005 // Combine FLAGS from an input object called NAME and the processor-specific
9006 // flags in the ELF header of the output. Much of this is adapted from the
9007 // processor-specific flags merging code in elf32_arm_merge_private_bfd_data
9008 // in bfd/elf32-arm.c.
9010 template<bool big_endian>
9012 Target_arm<big_endian>::merge_processor_specific_flags(
9013 const std::string& name,
9014 elfcpp::Elf_Word flags)
9016 if (this->are_processor_specific_flags_set())
9018 elfcpp::Elf_Word out_flags = this->processor_specific_flags();
9020 // Nothing to merge if flags equal to those in output.
9021 if (flags == out_flags)
9024 // Complain about various flag mismatches.
9025 elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags);
9026 elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags);
9027 if (!this->are_eabi_versions_compatible(version1, version2)
9028 && parameters->options().warn_mismatch())
9029 gold_error(_("Source object %s has EABI version %d but output has "
9030 "EABI version %d."),
9032 (flags & elfcpp::EF_ARM_EABIMASK) >> 24,
9033 (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24);
9037 // If the input is the default architecture and had the default
9038 // flags then do not bother setting the flags for the output
9039 // architecture, instead allow future merges to do this. If no
9040 // future merges ever set these flags then they will retain their
9041 // uninitialised values, which surprise surprise, correspond
9042 // to the default values.
9046 // This is the first time, just copy the flags.
9047 // We only copy the EABI version for now.
9048 this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK);
9052 // Adjust ELF file header.
9053 template<bool big_endian>
9055 Target_arm<big_endian>::do_adjust_elf_header(
9056 unsigned char* view,
9059 gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size);
9061 elfcpp::Ehdr<32, big_endian> ehdr(view);
9062 unsigned char e_ident[elfcpp::EI_NIDENT];
9063 memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT);
9065 if (elfcpp::arm_eabi_version(this->processor_specific_flags())
9066 == elfcpp::EF_ARM_EABI_UNKNOWN)
9067 e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM;
9069 e_ident[elfcpp::EI_OSABI] = 0;
9070 e_ident[elfcpp::EI_ABIVERSION] = 0;
9072 // FIXME: Do EF_ARM_BE8 adjustment.
9074 elfcpp::Ehdr_write<32, big_endian> oehdr(view);
9075 oehdr.put_e_ident(e_ident);
9078 // do_make_elf_object to override the same function in the base class.
9079 // We need to use a target-specific sub-class of Sized_relobj<32, big_endian>
9080 // to store ARM specific information. Hence we need to have our own
9081 // ELF object creation.
9083 template<bool big_endian>
9085 Target_arm<big_endian>::do_make_elf_object(
9086 const std::string& name,
9087 Input_file* input_file,
9088 off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr)
9090 int et = ehdr.get_e_type();
9091 if (et == elfcpp::ET_REL)
9093 Arm_relobj<big_endian>* obj =
9094 new Arm_relobj<big_endian>(name, input_file, offset, ehdr);
9098 else if (et == elfcpp::ET_DYN)
9100 Sized_dynobj<32, big_endian>* obj =
9101 new Arm_dynobj<big_endian>(name, input_file, offset, ehdr);
9107 gold_error(_("%s: unsupported ELF file type %d"),
9113 // Read the architecture from the Tag_also_compatible_with attribute, if any.
9114 // Returns -1 if no architecture could be read.
9115 // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c.
9117 template<bool big_endian>
9119 Target_arm<big_endian>::get_secondary_compatible_arch(
9120 const Attributes_section_data* pasd)
9122 const Object_attribute *known_attributes =
9123 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9125 // Note: the tag and its argument below are uleb128 values, though
9126 // currently-defined values fit in one byte for each.
9127 const std::string& sv =
9128 known_attributes[elfcpp::Tag_also_compatible_with].string_value();
9130 && sv.data()[0] == elfcpp::Tag_CPU_arch
9131 && (sv.data()[1] & 128) != 128)
9132 return sv.data()[1];
9134 // This tag is "safely ignorable", so don't complain if it looks funny.
9138 // Set, or unset, the architecture of the Tag_also_compatible_with attribute.
9139 // The tag is removed if ARCH is -1.
9140 // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c.
9142 template<bool big_endian>
9144 Target_arm<big_endian>::set_secondary_compatible_arch(
9145 Attributes_section_data* pasd,
9148 Object_attribute *known_attributes =
9149 pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC);
9153 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value("");
9157 // Note: the tag and its argument below are uleb128 values, though
9158 // currently-defined values fit in one byte for each.
9160 sv[0] = elfcpp::Tag_CPU_arch;
9161 gold_assert(arch != 0);
9165 known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv);
9168 // Combine two values for Tag_CPU_arch, taking secondary compatibility tags
9170 // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c.
9172 template<bool big_endian>
9174 Target_arm<big_endian>::tag_cpu_arch_combine(
9177 int* secondary_compat_out,
9179 int secondary_compat)
9181 #define T(X) elfcpp::TAG_CPU_ARCH_##X
9182 static const int v6t2[] =
9194 static const int v6k[] =
9207 static const int v7[] =
9221 static const int v6_m[] =
9236 static const int v6s_m[] =
9252 static const int v7e_m[] =
9269 static const int v4t_plus_v6_m[] =
9285 T(V4T_PLUS_V6_M) // V4T plus V6_M.
9287 static const int *comb[] =
9295 // Pseudo-architecture.
9299 // Check we've not got a higher architecture than we know about.
9301 if (oldtag >= elfcpp::MAX_TAG_CPU_ARCH || newtag >= elfcpp::MAX_TAG_CPU_ARCH)
9303 gold_error(_("%s: unknown CPU architecture"), name);
9307 // Override old tag if we have a Tag_also_compatible_with on the output.
9309 if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T))
9310 || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M)))
9311 oldtag = T(V4T_PLUS_V6_M);
9313 // And override the new tag if we have a Tag_also_compatible_with on the
9316 if ((newtag == T(V6_M) && secondary_compat == T(V4T))
9317 || (newtag == T(V4T) && secondary_compat == T(V6_M)))
9318 newtag = T(V4T_PLUS_V6_M);
9320 // Architectures before V6KZ add features monotonically.
9321 int tagh = std::max(oldtag, newtag);
9322 if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ)
9325 int tagl = std::min(oldtag, newtag);
9326 int result = comb[tagh - T(V6T2)][tagl];
9328 // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M)
9329 // as the canonical version.
9330 if (result == T(V4T_PLUS_V6_M))
9333 *secondary_compat_out = T(V6_M);
9336 *secondary_compat_out = -1;
9340 gold_error(_("%s: conflicting CPU architectures %d/%d"),
9341 name, oldtag, newtag);
9349 // Helper to print AEABI enum tag value.
9351 template<bool big_endian>
9353 Target_arm<big_endian>::aeabi_enum_name(unsigned int value)
9355 static const char *aeabi_enum_names[] =
9356 { "", "variable-size", "32-bit", "" };
9357 const size_t aeabi_enum_names_size =
9358 sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]);
9360 if (value < aeabi_enum_names_size)
9361 return std::string(aeabi_enum_names[value]);
9365 sprintf(buffer, "<unknown value %u>", value);
9366 return std::string(buffer);
9370 // Return the string value to store in TAG_CPU_name.
9372 template<bool big_endian>
9374 Target_arm<big_endian>::tag_cpu_name_value(unsigned int value)
9376 static const char *name_table[] = {
9377 // These aren't real CPU names, but we can't guess
9378 // that from the architecture version alone.
9394 const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]);
9396 if (value < name_table_size)
9397 return std::string(name_table[value]);
9401 sprintf(buffer, "<unknown CPU value %u>", value);
9402 return std::string(buffer);
9406 // Merge object attributes from input file called NAME with those of the
9407 // output. The input object attributes are in the object pointed by PASD.
9409 template<bool big_endian>
9411 Target_arm<big_endian>::merge_object_attributes(
9413 const Attributes_section_data* pasd)
9415 // Return if there is no attributes section data.
9419 // If output has no object attributes, just copy.
9420 if (this->attributes_section_data_ == NULL)
9422 this->attributes_section_data_ = new Attributes_section_data(*pasd);
9426 const int vendor = Object_attribute::OBJ_ATTR_PROC;
9427 const Object_attribute* in_attr = pasd->known_attributes(vendor);
9428 Object_attribute* out_attr =
9429 this->attributes_section_data_->known_attributes(vendor);
9431 // This needs to happen before Tag_ABI_FP_number_model is merged. */
9432 if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value()
9433 != out_attr[elfcpp::Tag_ABI_VFP_args].int_value())
9435 // Ignore mismatches if the object doesn't use floating point. */
9436 if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0)
9437 out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value(
9438 in_attr[elfcpp::Tag_ABI_VFP_args].int_value());
9439 else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0
9440 && parameters->options().warn_mismatch())
9441 gold_error(_("%s uses VFP register arguments, output does not"),
9445 for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i)
9447 // Merge this attribute with existing attributes.
9450 case elfcpp::Tag_CPU_raw_name:
9451 case elfcpp::Tag_CPU_name:
9452 // These are merged after Tag_CPU_arch.
9455 case elfcpp::Tag_ABI_optimization_goals:
9456 case elfcpp::Tag_ABI_FP_optimization_goals:
9457 // Use the first value seen.
9460 case elfcpp::Tag_CPU_arch:
9462 unsigned int saved_out_attr = out_attr->int_value();
9463 // Merge Tag_CPU_arch and Tag_also_compatible_with.
9464 int secondary_compat =
9465 this->get_secondary_compatible_arch(pasd);
9466 int secondary_compat_out =
9467 this->get_secondary_compatible_arch(
9468 this->attributes_section_data_);
9469 out_attr[i].set_int_value(
9470 tag_cpu_arch_combine(name, out_attr[i].int_value(),
9471 &secondary_compat_out,
9472 in_attr[i].int_value(),
9474 this->set_secondary_compatible_arch(this->attributes_section_data_,
9475 secondary_compat_out);
9477 // Merge Tag_CPU_name and Tag_CPU_raw_name.
9478 if (out_attr[i].int_value() == saved_out_attr)
9479 ; // Leave the names alone.
9480 else if (out_attr[i].int_value() == in_attr[i].int_value())
9482 // The output architecture has been changed to match the
9483 // input architecture. Use the input names.
9484 out_attr[elfcpp::Tag_CPU_name].set_string_value(
9485 in_attr[elfcpp::Tag_CPU_name].string_value());
9486 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(
9487 in_attr[elfcpp::Tag_CPU_raw_name].string_value());
9491 out_attr[elfcpp::Tag_CPU_name].set_string_value("");
9492 out_attr[elfcpp::Tag_CPU_raw_name].set_string_value("");
9495 // If we still don't have a value for Tag_CPU_name,
9496 // make one up now. Tag_CPU_raw_name remains blank.
9497 if (out_attr[elfcpp::Tag_CPU_name].string_value() == "")
9499 const std::string cpu_name =
9500 this->tag_cpu_name_value(out_attr[i].int_value());
9501 // FIXME: If we see an unknown CPU, this will be set
9502 // to "<unknown CPU n>", where n is the attribute value.
9503 // This is different from BFD, which leaves the name alone.
9504 out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name);
9509 case elfcpp::Tag_ARM_ISA_use:
9510 case elfcpp::Tag_THUMB_ISA_use:
9511 case elfcpp::Tag_WMMX_arch:
9512 case elfcpp::Tag_Advanced_SIMD_arch:
9513 // ??? Do Advanced_SIMD (NEON) and WMMX conflict?
9514 case elfcpp::Tag_ABI_FP_rounding:
9515 case elfcpp::Tag_ABI_FP_exceptions:
9516 case elfcpp::Tag_ABI_FP_user_exceptions:
9517 case elfcpp::Tag_ABI_FP_number_model:
9518 case elfcpp::Tag_VFP_HP_extension:
9519 case elfcpp::Tag_CPU_unaligned_access:
9520 case elfcpp::Tag_T2EE_use:
9521 case elfcpp::Tag_Virtualization_use:
9522 case elfcpp::Tag_MPextension_use:
9523 // Use the largest value specified.
9524 if (in_attr[i].int_value() > out_attr[i].int_value())
9525 out_attr[i].set_int_value(in_attr[i].int_value());
9528 case elfcpp::Tag_ABI_align8_preserved:
9529 case elfcpp::Tag_ABI_PCS_RO_data:
9530 // Use the smallest value specified.
9531 if (in_attr[i].int_value() < out_attr[i].int_value())
9532 out_attr[i].set_int_value(in_attr[i].int_value());
9535 case elfcpp::Tag_ABI_align8_needed:
9536 if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0)
9537 && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0
9538 || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value()
9541 // This error message should be enabled once all non-conformant
9542 // binaries in the toolchain have had the attributes set
9544 // gold_error(_("output 8-byte data alignment conflicts with %s"),
9548 case elfcpp::Tag_ABI_FP_denormal:
9549 case elfcpp::Tag_ABI_PCS_GOT_use:
9551 // These tags have 0 = don't care, 1 = strong requirement,
9552 // 2 = weak requirement.
9553 static const int order_021[3] = {0, 2, 1};
9555 // Use the "greatest" from the sequence 0, 2, 1, or the largest
9556 // value if greater than 2 (for future-proofing).
9557 if ((in_attr[i].int_value() > 2
9558 && in_attr[i].int_value() > out_attr[i].int_value())
9559 || (in_attr[i].int_value() <= 2
9560 && out_attr[i].int_value() <= 2
9561 && (order_021[in_attr[i].int_value()]
9562 > order_021[out_attr[i].int_value()])))
9563 out_attr[i].set_int_value(in_attr[i].int_value());
9567 case elfcpp::Tag_CPU_arch_profile:
9568 if (out_attr[i].int_value() != in_attr[i].int_value())
9570 // 0 will merge with anything.
9571 // 'A' and 'S' merge to 'A'.
9572 // 'R' and 'S' merge to 'R'.
9573 // 'M' and 'A|R|S' is an error.
9574 if (out_attr[i].int_value() == 0
9575 || (out_attr[i].int_value() == 'S'
9576 && (in_attr[i].int_value() == 'A'
9577 || in_attr[i].int_value() == 'R')))
9578 out_attr[i].set_int_value(in_attr[i].int_value());
9579 else if (in_attr[i].int_value() == 0
9580 || (in_attr[i].int_value() == 'S'
9581 && (out_attr[i].int_value() == 'A'
9582 || out_attr[i].int_value() == 'R')))
9584 else if (parameters->options().warn_mismatch())
9587 (_("conflicting architecture profiles %c/%c"),
9588 in_attr[i].int_value() ? in_attr[i].int_value() : '0',
9589 out_attr[i].int_value() ? out_attr[i].int_value() : '0');
9593 case elfcpp::Tag_VFP_arch:
9610 // Values greater than 6 aren't defined, so just pick the
9612 if (in_attr[i].int_value() > 6
9613 && in_attr[i].int_value() > out_attr[i].int_value())
9615 *out_attr = *in_attr;
9618 // The output uses the superset of input features
9619 // (ISA version) and registers.
9620 int ver = std::max(vfp_versions[in_attr[i].int_value()].ver,
9621 vfp_versions[out_attr[i].int_value()].ver);
9622 int regs = std::max(vfp_versions[in_attr[i].int_value()].regs,
9623 vfp_versions[out_attr[i].int_value()].regs);
9624 // This assumes all possible supersets are also a valid
9627 for (newval = 6; newval > 0; newval--)
9629 if (regs == vfp_versions[newval].regs
9630 && ver == vfp_versions[newval].ver)
9633 out_attr[i].set_int_value(newval);
9636 case elfcpp::Tag_PCS_config:
9637 if (out_attr[i].int_value() == 0)
9638 out_attr[i].set_int_value(in_attr[i].int_value());
9639 else if (in_attr[i].int_value() != 0
9640 && out_attr[i].int_value() != 0
9641 && parameters->options().warn_mismatch())
9643 // It's sometimes ok to mix different configs, so this is only
9645 gold_warning(_("%s: conflicting platform configuration"), name);
9648 case elfcpp::Tag_ABI_PCS_R9_use:
9649 if (in_attr[i].int_value() != out_attr[i].int_value()
9650 && out_attr[i].int_value() != elfcpp::AEABI_R9_unused
9651 && in_attr[i].int_value() != elfcpp::AEABI_R9_unused
9652 && parameters->options().warn_mismatch())
9654 gold_error(_("%s: conflicting use of R9"), name);
9656 if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused)
9657 out_attr[i].set_int_value(in_attr[i].int_value());
9659 case elfcpp::Tag_ABI_PCS_RW_data:
9660 if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel
9661 && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
9662 != elfcpp::AEABI_R9_SB)
9663 && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value()
9664 != elfcpp::AEABI_R9_unused)
9665 && parameters->options().warn_mismatch())
9667 gold_error(_("%s: SB relative addressing conflicts with use "
9671 // Use the smallest value specified.
9672 if (in_attr[i].int_value() < out_attr[i].int_value())
9673 out_attr[i].set_int_value(in_attr[i].int_value());
9675 case elfcpp::Tag_ABI_PCS_wchar_t:
9676 // FIXME: Make it possible to turn off this warning.
9677 if (out_attr[i].int_value()
9678 && in_attr[i].int_value()
9679 && out_attr[i].int_value() != in_attr[i].int_value()
9680 && parameters->options().warn_mismatch())
9682 gold_warning(_("%s uses %u-byte wchar_t yet the output is to "
9683 "use %u-byte wchar_t; use of wchar_t values "
9684 "across objects may fail"),
9685 name, in_attr[i].int_value(),
9686 out_attr[i].int_value());
9688 else if (in_attr[i].int_value() && !out_attr[i].int_value())
9689 out_attr[i].set_int_value(in_attr[i].int_value());
9691 case elfcpp::Tag_ABI_enum_size:
9692 if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused)
9694 if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused
9695 || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide)
9697 // The existing object is compatible with anything.
9698 // Use whatever requirements the new object has.
9699 out_attr[i].set_int_value(in_attr[i].int_value());
9701 // FIXME: Make it possible to turn off this warning.
9702 else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide
9703 && out_attr[i].int_value() != in_attr[i].int_value()
9704 && parameters->options().warn_mismatch())
9706 unsigned int in_value = in_attr[i].int_value();
9707 unsigned int out_value = out_attr[i].int_value();
9708 gold_warning(_("%s uses %s enums yet the output is to use "
9709 "%s enums; use of enum values across objects "
9712 this->aeabi_enum_name(in_value).c_str(),
9713 this->aeabi_enum_name(out_value).c_str());
9717 case elfcpp::Tag_ABI_VFP_args:
9720 case elfcpp::Tag_ABI_WMMX_args:
9721 if (in_attr[i].int_value() != out_attr[i].int_value()
9722 && parameters->options().warn_mismatch())
9724 gold_error(_("%s uses iWMMXt register arguments, output does "
9729 case Object_attribute::Tag_compatibility:
9730 // Merged in target-independent code.
9732 case elfcpp::Tag_ABI_HardFP_use:
9733 // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP).
9734 if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2)
9735 || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1))
9736 out_attr[i].set_int_value(3);
9737 else if (in_attr[i].int_value() > out_attr[i].int_value())
9738 out_attr[i].set_int_value(in_attr[i].int_value());
9740 case elfcpp::Tag_ABI_FP_16bit_format:
9741 if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0)
9743 if (in_attr[i].int_value() != out_attr[i].int_value()
9744 && parameters->options().warn_mismatch())
9745 gold_error(_("fp16 format mismatch between %s and output"),
9748 if (in_attr[i].int_value() != 0)
9749 out_attr[i].set_int_value(in_attr[i].int_value());
9752 case elfcpp::Tag_nodefaults:
9753 // This tag is set if it exists, but the value is unused (and is
9754 // typically zero). We don't actually need to do anything here -
9755 // the merge happens automatically when the type flags are merged
9758 case elfcpp::Tag_also_compatible_with:
9759 // Already done in Tag_CPU_arch.
9761 case elfcpp::Tag_conformance:
9762 // Keep the attribute if it matches. Throw it away otherwise.
9763 // No attribute means no claim to conform.
9764 if (in_attr[i].string_value() != out_attr[i].string_value())
9765 out_attr[i].set_string_value("");
9770 const char* err_object = NULL;
9772 // The "known_obj_attributes" table does contain some undefined
9773 // attributes. Ensure that there are unused.
9774 if (out_attr[i].int_value() != 0
9775 || out_attr[i].string_value() != "")
9776 err_object = "output";
9777 else if (in_attr[i].int_value() != 0
9778 || in_attr[i].string_value() != "")
9781 if (err_object != NULL
9782 && parameters->options().warn_mismatch())
9784 // Attribute numbers >=64 (mod 128) can be safely ignored.
9786 gold_error(_("%s: unknown mandatory EABI object attribute "
9790 gold_warning(_("%s: unknown EABI object attribute %d"),
9794 // Only pass on attributes that match in both inputs.
9795 if (!in_attr[i].matches(out_attr[i]))
9797 out_attr[i].set_int_value(0);
9798 out_attr[i].set_string_value("");
9803 // If out_attr was copied from in_attr then it won't have a type yet.
9804 if (in_attr[i].type() && !out_attr[i].type())
9805 out_attr[i].set_type(in_attr[i].type());
9808 // Merge Tag_compatibility attributes and any common GNU ones.
9809 this->attributes_section_data_->merge(name, pasd);
9811 // Check for any attributes not known on ARM.
9812 typedef Vendor_object_attributes::Other_attributes Other_attributes;
9813 const Other_attributes* in_other_attributes = pasd->other_attributes(vendor);
9814 Other_attributes::const_iterator in_iter = in_other_attributes->begin();
9815 Other_attributes* out_other_attributes =
9816 this->attributes_section_data_->other_attributes(vendor);
9817 Other_attributes::iterator out_iter = out_other_attributes->begin();
9819 while (in_iter != in_other_attributes->end()
9820 || out_iter != out_other_attributes->end())
9822 const char* err_object = NULL;
9825 // The tags for each list are in numerical order.
9826 // If the tags are equal, then merge.
9827 if (out_iter != out_other_attributes->end()
9828 && (in_iter == in_other_attributes->end()
9829 || in_iter->first > out_iter->first))
9831 // This attribute only exists in output. We can't merge, and we
9832 // don't know what the tag means, so delete it.
9833 err_object = "output";
9834 err_tag = out_iter->first;
9835 int saved_tag = out_iter->first;
9836 delete out_iter->second;
9837 out_other_attributes->erase(out_iter);
9838 out_iter = out_other_attributes->upper_bound(saved_tag);
9840 else if (in_iter != in_other_attributes->end()
9841 && (out_iter != out_other_attributes->end()
9842 || in_iter->first < out_iter->first))
9844 // This attribute only exists in input. We can't merge, and we
9845 // don't know what the tag means, so ignore it.
9847 err_tag = in_iter->first;
9850 else // The tags are equal.
9852 // As present, all attributes in the list are unknown, and
9853 // therefore can't be merged meaningfully.
9854 err_object = "output";
9855 err_tag = out_iter->first;
9857 // Only pass on attributes that match in both inputs.
9858 if (!in_iter->second->matches(*(out_iter->second)))
9860 // No match. Delete the attribute.
9861 int saved_tag = out_iter->first;
9862 delete out_iter->second;
9863 out_other_attributes->erase(out_iter);
9864 out_iter = out_other_attributes->upper_bound(saved_tag);
9868 // Matched. Keep the attribute and move to the next.
9874 if (err_object && parameters->options().warn_mismatch())
9876 // Attribute numbers >=64 (mod 128) can be safely ignored. */
9877 if ((err_tag & 127) < 64)
9879 gold_error(_("%s: unknown mandatory EABI object attribute %d"),
9880 err_object, err_tag);
9884 gold_warning(_("%s: unknown EABI object attribute %d"),
9885 err_object, err_tag);
9891 // Stub-generation methods for Target_arm.
9893 // Make a new Arm_input_section object.
9895 template<bool big_endian>
9896 Arm_input_section<big_endian>*
9897 Target_arm<big_endian>::new_arm_input_section(
9901 Section_id sid(relobj, shndx);
9903 Arm_input_section<big_endian>* arm_input_section =
9904 new Arm_input_section<big_endian>(relobj, shndx);
9905 arm_input_section->init();
9907 // Register new Arm_input_section in map for look-up.
9908 std::pair<typename Arm_input_section_map::iterator, bool> ins =
9909 this->arm_input_section_map_.insert(std::make_pair(sid, arm_input_section));
9911 // Make sure that it we have not created another Arm_input_section
9912 // for this input section already.
9913 gold_assert(ins.second);
9915 return arm_input_section;
9918 // Find the Arm_input_section object corresponding to the SHNDX-th input
9919 // section of RELOBJ.
9921 template<bool big_endian>
9922 Arm_input_section<big_endian>*
9923 Target_arm<big_endian>::find_arm_input_section(
9925 unsigned int shndx) const
9927 Section_id sid(relobj, shndx);
9928 typename Arm_input_section_map::const_iterator p =
9929 this->arm_input_section_map_.find(sid);
9930 return (p != this->arm_input_section_map_.end()) ? p->second : NULL;
9933 // Make a new stub table.
9935 template<bool big_endian>
9936 Stub_table<big_endian>*
9937 Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner)
9939 Stub_table<big_endian>* stub_table =
9940 new Stub_table<big_endian>(owner);
9941 this->stub_tables_.push_back(stub_table);
9943 stub_table->set_address(owner->address() + owner->data_size());
9944 stub_table->set_file_offset(owner->offset() + owner->data_size());
9945 stub_table->finalize_data_size();
9950 // Scan a relocation for stub generation.
9952 template<bool big_endian>
9954 Target_arm<big_endian>::scan_reloc_for_stub(
9955 const Relocate_info<32, big_endian>* relinfo,
9956 unsigned int r_type,
9957 const Sized_symbol<32>* gsym,
9959 const Symbol_value<32>* psymval,
9960 elfcpp::Elf_types<32>::Elf_Swxword addend,
9961 Arm_address address)
9963 typedef typename Target_arm<big_endian>::Relocate Relocate;
9965 const Arm_relobj<big_endian>* arm_relobj =
9966 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
9968 bool target_is_thumb;
9969 Symbol_value<32> symval;
9972 // This is a global symbol. Determine if we use PLT and if the
9973 // final target is THUMB.
9974 if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type)))
9976 // This uses a PLT, change the symbol value.
9977 symval.set_output_value(this->plt_section()->address()
9978 + gsym->plt_offset());
9980 target_is_thumb = false;
9982 else if (gsym->is_undefined())
9983 // There is no need to generate a stub symbol is undefined.
9988 ((gsym->type() == elfcpp::STT_ARM_TFUNC)
9989 || (gsym->type() == elfcpp::STT_FUNC
9990 && !gsym->is_undefined()
9991 && ((psymval->value(arm_relobj, 0) & 1) != 0)));
9996 // This is a local symbol. Determine if the final target is THUMB.
9997 target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym);
10000 // Strip LSB if this points to a THUMB target.
10001 const Arm_reloc_property* reloc_property =
10002 arm_reloc_property_table->get_implemented_static_reloc_property(r_type);
10003 gold_assert(reloc_property != NULL);
10004 if (target_is_thumb
10005 && reloc_property->uses_thumb_bit()
10006 && ((psymval->value(arm_relobj, 0) & 1) != 0))
10008 Arm_address stripped_value =
10009 psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1);
10010 symval.set_output_value(stripped_value);
10014 // Get the symbol value.
10015 Symbol_value<32>::Value value = psymval->value(arm_relobj, 0);
10017 // Owing to pipelining, the PC relative branches below actually skip
10018 // two instructions when the branch offset is 0.
10019 Arm_address destination;
10022 case elfcpp::R_ARM_CALL:
10023 case elfcpp::R_ARM_JUMP24:
10024 case elfcpp::R_ARM_PLT32:
10026 destination = value + addend + 8;
10028 case elfcpp::R_ARM_THM_CALL:
10029 case elfcpp::R_ARM_THM_XPC22:
10030 case elfcpp::R_ARM_THM_JUMP24:
10031 case elfcpp::R_ARM_THM_JUMP19:
10033 destination = value + addend + 4;
10036 gold_unreachable();
10039 Reloc_stub* stub = NULL;
10040 Stub_type stub_type =
10041 Reloc_stub::stub_type_for_reloc(r_type, address, destination,
10043 if (stub_type != arm_stub_none)
10045 // Try looking up an existing stub from a stub table.
10046 Stub_table<big_endian>* stub_table =
10047 arm_relobj->stub_table(relinfo->data_shndx);
10048 gold_assert(stub_table != NULL);
10050 // Locate stub by destination.
10051 Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend);
10053 // Create a stub if there is not one already
10054 stub = stub_table->find_reloc_stub(stub_key);
10057 // create a new stub and add it to stub table.
10058 stub = this->stub_factory().make_reloc_stub(stub_type);
10059 stub_table->add_reloc_stub(stub, stub_key);
10062 // Record the destination address.
10063 stub->set_destination_address(destination
10064 | (target_is_thumb ? 1 : 0));
10067 // For Cortex-A8, we need to record a relocation at 4K page boundary.
10068 if (this->fix_cortex_a8_
10069 && (r_type == elfcpp::R_ARM_THM_JUMP24
10070 || r_type == elfcpp::R_ARM_THM_JUMP19
10071 || r_type == elfcpp::R_ARM_THM_CALL
10072 || r_type == elfcpp::R_ARM_THM_XPC22)
10073 && (address & 0xfffU) == 0xffeU)
10075 // Found a candidate. Note we haven't checked the destination is
10076 // within 4K here: if we do so (and don't create a record) we can't
10077 // tell that a branch should have been relocated when scanning later.
10078 this->cortex_a8_relocs_info_[address] =
10079 new Cortex_a8_reloc(stub, r_type,
10080 destination | (target_is_thumb ? 1 : 0));
10084 // This function scans a relocation sections for stub generation.
10085 // The template parameter Relocate must be a class type which provides
10086 // a single function, relocate(), which implements the machine
10087 // specific part of a relocation.
10089 // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type:
10090 // SHT_REL or SHT_RELA.
10092 // PRELOCS points to the relocation data. RELOC_COUNT is the number
10093 // of relocs. OUTPUT_SECTION is the output section.
10094 // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be
10095 // mapped to output offsets.
10097 // VIEW is the section data, VIEW_ADDRESS is its memory address, and
10098 // VIEW_SIZE is the size. These refer to the input section, unless
10099 // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to
10100 // the output section.
10102 template<bool big_endian>
10103 template<int sh_type>
10105 Target_arm<big_endian>::scan_reloc_section_for_stubs(
10106 const Relocate_info<32, big_endian>* relinfo,
10107 const unsigned char* prelocs,
10108 size_t reloc_count,
10109 Output_section* output_section,
10110 bool needs_special_offset_handling,
10111 const unsigned char* view,
10112 elfcpp::Elf_types<32>::Elf_Addr view_address,
10115 typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype;
10116 const int reloc_size =
10117 Reloc_types<sh_type, 32, big_endian>::reloc_size;
10119 Arm_relobj<big_endian>* arm_object =
10120 Arm_relobj<big_endian>::as_arm_relobj(relinfo->object);
10121 unsigned int local_count = arm_object->local_symbol_count();
10123 Comdat_behavior comdat_behavior = CB_UNDETERMINED;
10125 for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size)
10127 Reltype reloc(prelocs);
10129 typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info();
10130 unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info);
10131 unsigned int r_type = elfcpp::elf_r_type<32>(r_info);
10133 r_type = this->get_real_reloc_type(r_type);
10135 // Only a few relocation types need stubs.
10136 if ((r_type != elfcpp::R_ARM_CALL)
10137 && (r_type != elfcpp::R_ARM_JUMP24)
10138 && (r_type != elfcpp::R_ARM_PLT32)
10139 && (r_type != elfcpp::R_ARM_THM_CALL)
10140 && (r_type != elfcpp::R_ARM_THM_XPC22)
10141 && (r_type != elfcpp::R_ARM_THM_JUMP24)
10142 && (r_type != elfcpp::R_ARM_THM_JUMP19)
10143 && (r_type != elfcpp::R_ARM_V4BX))
10146 section_offset_type offset =
10147 convert_to_section_size_type(reloc.get_r_offset());
10149 if (needs_special_offset_handling)
10151 offset = output_section->output_offset(relinfo->object,
10152 relinfo->data_shndx,
10158 // Create a v4bx stub if --fix-v4bx-interworking is used.
10159 if (r_type == elfcpp::R_ARM_V4BX)
10161 if (this->fix_v4bx() == General_options::FIX_V4BX_INTERWORKING)
10163 // Get the BX instruction.
10164 typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype;
10165 const Valtype* wv =
10166 reinterpret_cast<const Valtype*>(view + offset);
10167 elfcpp::Elf_types<32>::Elf_Swxword insn =
10168 elfcpp::Swap<32, big_endian>::readval(wv);
10169 const uint32_t reg = (insn & 0xf);
10173 // Try looking up an existing stub from a stub table.
10174 Stub_table<big_endian>* stub_table =
10175 arm_object->stub_table(relinfo->data_shndx);
10176 gold_assert(stub_table != NULL);
10178 if (stub_table->find_arm_v4bx_stub(reg) == NULL)
10180 // create a new stub and add it to stub table.
10181 Arm_v4bx_stub* stub =
10182 this->stub_factory().make_arm_v4bx_stub(reg);
10183 gold_assert(stub != NULL);
10184 stub_table->add_arm_v4bx_stub(stub);
10192 Stub_addend_reader<sh_type, big_endian> stub_addend_reader;
10193 elfcpp::Elf_types<32>::Elf_Swxword addend =
10194 stub_addend_reader(r_type, view + offset, reloc);
10196 const Sized_symbol<32>* sym;
10198 Symbol_value<32> symval;
10199 const Symbol_value<32> *psymval;
10200 if (r_sym < local_count)
10203 psymval = arm_object->local_symbol(r_sym);
10205 // If the local symbol belongs to a section we are discarding,
10206 // and that section is a debug section, try to find the
10207 // corresponding kept section and map this symbol to its
10208 // counterpart in the kept section. The symbol must not
10209 // correspond to a section we are folding.
10211 unsigned int shndx = psymval->input_shndx(&is_ordinary);
10213 && shndx != elfcpp::SHN_UNDEF
10214 && !arm_object->is_section_included(shndx)
10215 && !(relinfo->symtab->is_section_folded(arm_object, shndx)))
10217 if (comdat_behavior == CB_UNDETERMINED)
10220 arm_object->section_name(relinfo->data_shndx);
10221 comdat_behavior = get_comdat_behavior(name.c_str());
10223 if (comdat_behavior == CB_PRETEND)
10226 typename elfcpp::Elf_types<32>::Elf_Addr value =
10227 arm_object->map_to_kept_section(shndx, &found);
10229 symval.set_output_value(value + psymval->input_value());
10231 symval.set_output_value(0);
10235 symval.set_output_value(0);
10237 symval.set_no_output_symtab_entry();
10243 const Symbol* gsym = arm_object->global_symbol(r_sym);
10244 gold_assert(gsym != NULL);
10245 if (gsym->is_forwarder())
10246 gsym = relinfo->symtab->resolve_forwards(gsym);
10248 sym = static_cast<const Sized_symbol<32>*>(gsym);
10249 if (sym->has_symtab_index())
10250 symval.set_output_symtab_index(sym->symtab_index());
10252 symval.set_no_output_symtab_entry();
10254 // We need to compute the would-be final value of this global
10256 const Symbol_table* symtab = relinfo->symtab;
10257 const Sized_symbol<32>* sized_symbol =
10258 symtab->get_sized_symbol<32>(gsym);
10259 Symbol_table::Compute_final_value_status status;
10260 Arm_address value =
10261 symtab->compute_final_value<32>(sized_symbol, &status);
10263 // Skip this if the symbol has not output section.
10264 if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION)
10267 symval.set_output_value(value);
10271 // If symbol is a section symbol, we don't know the actual type of
10272 // destination. Give up.
10273 if (psymval->is_section_symbol())
10276 this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval,
10277 addend, view_address + offset);
10281 // Scan an input section for stub generation.
10283 template<bool big_endian>
10285 Target_arm<big_endian>::scan_section_for_stubs(
10286 const Relocate_info<32, big_endian>* relinfo,
10287 unsigned int sh_type,
10288 const unsigned char* prelocs,
10289 size_t reloc_count,
10290 Output_section* output_section,
10291 bool needs_special_offset_handling,
10292 const unsigned char* view,
10293 Arm_address view_address,
10294 section_size_type view_size)
10296 if (sh_type == elfcpp::SHT_REL)
10297 this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>(
10302 needs_special_offset_handling,
10306 else if (sh_type == elfcpp::SHT_RELA)
10307 // We do not support RELA type relocations yet. This is provided for
10309 this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>(
10314 needs_special_offset_handling,
10319 gold_unreachable();
10322 // Group input sections for stub generation.
10324 // We goup input sections in an output sections so that the total size,
10325 // including any padding space due to alignment is smaller than GROUP_SIZE
10326 // unless the only input section in group is bigger than GROUP_SIZE already.
10327 // Then an ARM stub table is created to follow the last input section
10328 // in group. For each group an ARM stub table is created an is placed
10329 // after the last group. If STUB_ALWATS_AFTER_BRANCH is false, we further
10330 // extend the group after the stub table.
10332 template<bool big_endian>
10334 Target_arm<big_endian>::group_sections(
10336 section_size_type group_size,
10337 bool stubs_always_after_branch)
10339 // Group input sections and insert stub table
10340 Layout::Section_list section_list;
10341 layout->get_allocated_sections(§ion_list);
10342 for (Layout::Section_list::const_iterator p = section_list.begin();
10343 p != section_list.end();
10346 Arm_output_section<big_endian>* output_section =
10347 Arm_output_section<big_endian>::as_arm_output_section(*p);
10348 output_section->group_sections(group_size, stubs_always_after_branch,
10353 // Relaxation hook. This is where we do stub generation.
10355 template<bool big_endian>
10357 Target_arm<big_endian>::do_relax(
10359 const Input_objects* input_objects,
10360 Symbol_table* symtab,
10363 // No need to generate stubs if this is a relocatable link.
10364 gold_assert(!parameters->options().relocatable());
10366 // If this is the first pass, we need to group input sections into
10368 bool done_exidx_fixup = false;
10371 // Determine the stub group size. The group size is the absolute
10372 // value of the parameter --stub-group-size. If --stub-group-size
10373 // is passed a negative value, we restict stubs to be always after
10374 // the stubbed branches.
10375 int32_t stub_group_size_param =
10376 parameters->options().stub_group_size();
10377 bool stubs_always_after_branch = stub_group_size_param < 0;
10378 section_size_type stub_group_size = abs(stub_group_size_param);
10380 // The Cortex-A8 erratum fix depends on stubs not being in the same 4K
10381 // page as the first half of a 32-bit branch straddling two 4K pages.
10382 // This is a crude way of enforcing that.
10383 if (this->fix_cortex_a8_)
10384 stubs_always_after_branch = true;
10386 if (stub_group_size == 1)
10389 // Thumb branch range is +-4MB has to be used as the default
10390 // maximum size (a given section can contain both ARM and Thumb
10391 // code, so the worst case has to be taken into account). If we are
10392 // fixing cortex-a8 errata, the branch range has to be even smaller,
10393 // since wide conditional branch has a range of +-1MB only.
10395 // This value is 24K less than that, which allows for 2025
10396 // 12-byte stubs. If we exceed that, then we will fail to link.
10397 // The user will have to relink with an explicit group size
10399 if (this->fix_cortex_a8_)
10400 stub_group_size = 1024276;
10402 stub_group_size = 4170000;
10405 group_sections(layout, stub_group_size, stubs_always_after_branch);
10407 // Also fix .ARM.exidx section coverage.
10408 Output_section* os = layout->find_output_section(".ARM.exidx");
10409 if (os != NULL && os->type() == elfcpp::SHT_ARM_EXIDX)
10411 Arm_output_section<big_endian>* exidx_output_section =
10412 Arm_output_section<big_endian>::as_arm_output_section(os);
10413 this->fix_exidx_coverage(layout, exidx_output_section, symtab);
10414 done_exidx_fixup = true;
10418 // The Cortex-A8 stubs are sensitive to layout of code sections. At the
10419 // beginning of each relaxation pass, just blow away all the stubs.
10420 // Alternatively, we could selectively remove only the stubs and reloc
10421 // information for code sections that have moved since the last pass.
10422 // That would require more book-keeping.
10423 typedef typename Stub_table_list::iterator Stub_table_iterator;
10424 if (this->fix_cortex_a8_)
10426 // Clear all Cortex-A8 reloc information.
10427 for (typename Cortex_a8_relocs_info::const_iterator p =
10428 this->cortex_a8_relocs_info_.begin();
10429 p != this->cortex_a8_relocs_info_.end();
10432 this->cortex_a8_relocs_info_.clear();
10434 // Remove all Cortex-A8 stubs.
10435 for (Stub_table_iterator sp = this->stub_tables_.begin();
10436 sp != this->stub_tables_.end();
10438 (*sp)->remove_all_cortex_a8_stubs();
10441 // Scan relocs for relocation stubs
10442 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
10443 op != input_objects->relobj_end();
10446 Arm_relobj<big_endian>* arm_relobj =
10447 Arm_relobj<big_endian>::as_arm_relobj(*op);
10448 arm_relobj->scan_sections_for_stubs(this, symtab, layout);
10451 // Check all stub tables to see if any of them have their data sizes
10452 // or addresses alignments changed. These are the only things that
10454 bool any_stub_table_changed = false;
10455 Unordered_set<const Output_section*> sections_needing_adjustment;
10456 for (Stub_table_iterator sp = this->stub_tables_.begin();
10457 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
10460 if ((*sp)->update_data_size_and_addralign())
10462 // Update data size of stub table owner.
10463 Arm_input_section<big_endian>* owner = (*sp)->owner();
10464 uint64_t address = owner->address();
10465 off_t offset = owner->offset();
10466 owner->reset_address_and_file_offset();
10467 owner->set_address_and_file_offset(address, offset);
10469 sections_needing_adjustment.insert(owner->output_section());
10470 any_stub_table_changed = true;
10474 // Output_section_data::output_section() returns a const pointer but we
10475 // need to update output sections, so we record all output sections needing
10476 // update above and scan the sections here to find out what sections need
10478 for(Layout::Section_list::const_iterator p = layout->section_list().begin();
10479 p != layout->section_list().end();
10482 if (sections_needing_adjustment.find(*p)
10483 != sections_needing_adjustment.end())
10484 (*p)->set_section_offsets_need_adjustment();
10487 // Stop relaxation if no EXIDX fix-up and no stub table change.
10488 bool continue_relaxation = done_exidx_fixup || any_stub_table_changed;
10490 // Finalize the stubs in the last relaxation pass.
10491 if (!continue_relaxation)
10493 for (Stub_table_iterator sp = this->stub_tables_.begin();
10494 (sp != this->stub_tables_.end()) && !any_stub_table_changed;
10496 (*sp)->finalize_stubs();
10498 // Update output local symbol counts of objects if necessary.
10499 for (Input_objects::Relobj_iterator op = input_objects->relobj_begin();
10500 op != input_objects->relobj_end();
10503 Arm_relobj<big_endian>* arm_relobj =
10504 Arm_relobj<big_endian>::as_arm_relobj(*op);
10506 // Update output local symbol counts. We need to discard local
10507 // symbols defined in parts of input sections that are discarded by
10509 if (arm_relobj->output_local_symbol_count_needs_update())
10510 arm_relobj->update_output_local_symbol_count();
10514 return continue_relaxation;
10517 // Relocate a stub.
10519 template<bool big_endian>
10521 Target_arm<big_endian>::relocate_stub(
10523 const Relocate_info<32, big_endian>* relinfo,
10524 Output_section* output_section,
10525 unsigned char* view,
10526 Arm_address address,
10527 section_size_type view_size)
10530 const Stub_template* stub_template = stub->stub_template();
10531 for (size_t i = 0; i < stub_template->reloc_count(); i++)
10533 size_t reloc_insn_index = stub_template->reloc_insn_index(i);
10534 const Insn_template* insn = &stub_template->insns()[reloc_insn_index];
10536 unsigned int r_type = insn->r_type();
10537 section_size_type reloc_offset = stub_template->reloc_offset(i);
10538 section_size_type reloc_size = insn->size();
10539 gold_assert(reloc_offset + reloc_size <= view_size);
10541 // This is the address of the stub destination.
10542 Arm_address target = stub->reloc_target(i) + insn->reloc_addend();
10543 Symbol_value<32> symval;
10544 symval.set_output_value(target);
10546 // Synthesize a fake reloc just in case. We don't have a symbol so
10548 unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size];
10549 memset(reloc_buffer, 0, sizeof(reloc_buffer));
10550 elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer);
10551 reloc_write.put_r_offset(reloc_offset);
10552 reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type));
10553 elfcpp::Rel<32, big_endian> rel(reloc_buffer);
10555 relocate.relocate(relinfo, this, output_section,
10556 this->fake_relnum_for_stubs, rel, r_type,
10557 NULL, &symval, view + reloc_offset,
10558 address + reloc_offset, reloc_size);
10562 // Determine whether an object attribute tag takes an integer, a
10565 template<bool big_endian>
10567 Target_arm<big_endian>::do_attribute_arg_type(int tag) const
10569 if (tag == Object_attribute::Tag_compatibility)
10570 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
10571 | Object_attribute::ATTR_TYPE_FLAG_STR_VAL);
10572 else if (tag == elfcpp::Tag_nodefaults)
10573 return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL
10574 | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT);
10575 else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name)
10576 return Object_attribute::ATTR_TYPE_FLAG_STR_VAL;
10578 return Object_attribute::ATTR_TYPE_FLAG_INT_VAL;
10580 return ((tag & 1) != 0
10581 ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL
10582 : Object_attribute::ATTR_TYPE_FLAG_INT_VAL);
10585 // Reorder attributes.
10587 // The ABI defines that Tag_conformance should be emitted first, and that
10588 // Tag_nodefaults should be second (if either is defined). This sets those
10589 // two positions, and bumps up the position of all the remaining tags to
10592 template<bool big_endian>
10594 Target_arm<big_endian>::do_attributes_order(int num) const
10596 // Reorder the known object attributes in output. We want to move
10597 // Tag_conformance to position 4 and Tag_conformance to position 5
10598 // and shift eveything between 4 .. Tag_conformance - 1 to make room.
10600 return elfcpp::Tag_conformance;
10602 return elfcpp::Tag_nodefaults;
10603 if ((num - 2) < elfcpp::Tag_nodefaults)
10605 if ((num - 1) < elfcpp::Tag_conformance)
10610 // Scan a span of THUMB code for Cortex-A8 erratum.
10612 template<bool big_endian>
10614 Target_arm<big_endian>::scan_span_for_cortex_a8_erratum(
10615 Arm_relobj<big_endian>* arm_relobj,
10616 unsigned int shndx,
10617 section_size_type span_start,
10618 section_size_type span_end,
10619 const unsigned char* view,
10620 Arm_address address)
10622 // Scan for 32-bit Thumb-2 branches which span two 4K regions, where:
10624 // The opcode is BLX.W, BL.W, B.W, Bcc.W
10625 // The branch target is in the same 4KB region as the
10626 // first half of the branch.
10627 // The instruction before the branch is a 32-bit
10628 // length non-branch instruction.
10629 section_size_type i = span_start;
10630 bool last_was_32bit = false;
10631 bool last_was_branch = false;
10632 while (i < span_end)
10634 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
10635 const Valtype* wv = reinterpret_cast<const Valtype*>(view + i);
10636 uint32_t insn = elfcpp::Swap<16, big_endian>::readval(wv);
10637 bool is_blx = false, is_b = false;
10638 bool is_bl = false, is_bcc = false;
10640 bool insn_32bit = (insn & 0xe000) == 0xe000 && (insn & 0x1800) != 0x0000;
10643 // Load the rest of the insn (in manual-friendly order).
10644 insn = (insn << 16) | elfcpp::Swap<16, big_endian>::readval(wv + 1);
10646 // Encoding T4: B<c>.W.
10647 is_b = (insn & 0xf800d000U) == 0xf0009000U;
10648 // Encoding T1: BL<c>.W.
10649 is_bl = (insn & 0xf800d000U) == 0xf000d000U;
10650 // Encoding T2: BLX<c>.W.
10651 is_blx = (insn & 0xf800d000U) == 0xf000c000U;
10652 // Encoding T3: B<c>.W (not permitted in IT block).
10653 is_bcc = ((insn & 0xf800d000U) == 0xf0008000U
10654 && (insn & 0x07f00000U) != 0x03800000U);
10657 bool is_32bit_branch = is_b || is_bl || is_blx || is_bcc;
10659 // If this instruction is a 32-bit THUMB branch that crosses a 4K
10660 // page boundary and it follows 32-bit non-branch instruction,
10661 // we need to work around.
10662 if (is_32bit_branch
10663 && ((address + i) & 0xfffU) == 0xffeU
10665 && !last_was_branch)
10667 // Check to see if there is a relocation stub for this branch.
10668 bool force_target_arm = false;
10669 bool force_target_thumb = false;
10670 const Cortex_a8_reloc* cortex_a8_reloc = NULL;
10671 Cortex_a8_relocs_info::const_iterator p =
10672 this->cortex_a8_relocs_info_.find(address + i);
10674 if (p != this->cortex_a8_relocs_info_.end())
10676 cortex_a8_reloc = p->second;
10677 bool target_is_thumb = (cortex_a8_reloc->destination() & 1) != 0;
10679 if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
10680 && !target_is_thumb)
10681 force_target_arm = true;
10682 else if (cortex_a8_reloc->r_type() == elfcpp::R_ARM_THM_CALL
10683 && target_is_thumb)
10684 force_target_thumb = true;
10688 Stub_type stub_type = arm_stub_none;
10690 // Check if we have an offending branch instruction.
10691 uint16_t upper_insn = (insn >> 16) & 0xffffU;
10692 uint16_t lower_insn = insn & 0xffffU;
10693 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
10695 if (cortex_a8_reloc != NULL
10696 && cortex_a8_reloc->reloc_stub() != NULL)
10697 // We've already made a stub for this instruction, e.g.
10698 // it's a long branch or a Thumb->ARM stub. Assume that
10699 // stub will suffice to work around the A8 erratum (see
10700 // setting of always_after_branch above).
10704 offset = RelocFuncs::thumb32_cond_branch_offset(upper_insn,
10706 stub_type = arm_stub_a8_veneer_b_cond;
10708 else if (is_b || is_bl || is_blx)
10710 offset = RelocFuncs::thumb32_branch_offset(upper_insn,
10715 stub_type = (is_blx
10716 ? arm_stub_a8_veneer_blx
10718 ? arm_stub_a8_veneer_bl
10719 : arm_stub_a8_veneer_b));
10722 if (stub_type != arm_stub_none)
10724 Arm_address pc_for_insn = address + i + 4;
10726 // The original instruction is a BL, but the target is
10727 // an ARM instruction. If we were not making a stub,
10728 // the BL would have been converted to a BLX. Use the
10729 // BLX stub instead in that case.
10730 if (this->may_use_blx() && force_target_arm
10731 && stub_type == arm_stub_a8_veneer_bl)
10733 stub_type = arm_stub_a8_veneer_blx;
10737 // Conversely, if the original instruction was
10738 // BLX but the target is Thumb mode, use the BL stub.
10739 else if (force_target_thumb
10740 && stub_type == arm_stub_a8_veneer_blx)
10742 stub_type = arm_stub_a8_veneer_bl;
10750 // If we found a relocation, use the proper destination,
10751 // not the offset in the (unrelocated) instruction.
10752 // Note this is always done if we switched the stub type above.
10753 if (cortex_a8_reloc != NULL)
10754 offset = (off_t) (cortex_a8_reloc->destination() - pc_for_insn);
10756 Arm_address target = (pc_for_insn + offset) | (is_blx ? 0 : 1);
10758 // Add a new stub if destination address in in the same page.
10759 if (((address + i) & ~0xfffU) == (target & ~0xfffU))
10761 Cortex_a8_stub* stub =
10762 this->stub_factory_.make_cortex_a8_stub(stub_type,
10766 Stub_table<big_endian>* stub_table =
10767 arm_relobj->stub_table(shndx);
10768 gold_assert(stub_table != NULL);
10769 stub_table->add_cortex_a8_stub(address + i, stub);
10774 i += insn_32bit ? 4 : 2;
10775 last_was_32bit = insn_32bit;
10776 last_was_branch = is_32bit_branch;
10780 // Apply the Cortex-A8 workaround.
10782 template<bool big_endian>
10784 Target_arm<big_endian>::apply_cortex_a8_workaround(
10785 const Cortex_a8_stub* stub,
10786 Arm_address stub_address,
10787 unsigned char* insn_view,
10788 Arm_address insn_address)
10790 typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype;
10791 Valtype* wv = reinterpret_cast<Valtype*>(insn_view);
10792 Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv);
10793 Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1);
10794 off_t branch_offset = stub_address - (insn_address + 4);
10796 typedef struct Arm_relocate_functions<big_endian> RelocFuncs;
10797 switch (stub->stub_template()->type())
10799 case arm_stub_a8_veneer_b_cond:
10800 gold_assert(!utils::has_overflow<21>(branch_offset));
10801 upper_insn = RelocFuncs::thumb32_cond_branch_upper(upper_insn,
10803 lower_insn = RelocFuncs::thumb32_cond_branch_lower(lower_insn,
10807 case arm_stub_a8_veneer_b:
10808 case arm_stub_a8_veneer_bl:
10809 case arm_stub_a8_veneer_blx:
10810 if ((lower_insn & 0x5000U) == 0x4000U)
10811 // For a BLX instruction, make sure that the relocation is
10812 // rounded up to a word boundary. This follows the semantics of
10813 // the instruction which specifies that bit 1 of the target
10814 // address will come from bit 1 of the base address.
10815 branch_offset = (branch_offset + 2) & ~3;
10817 // Put BRANCH_OFFSET back into the insn.
10818 gold_assert(!utils::has_overflow<25>(branch_offset));
10819 upper_insn = RelocFuncs::thumb32_branch_upper(upper_insn, branch_offset);
10820 lower_insn = RelocFuncs::thumb32_branch_lower(lower_insn, branch_offset);
10824 gold_unreachable();
10827 // Put the relocated value back in the object file:
10828 elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn);
10829 elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn);
10832 template<bool big_endian>
10833 class Target_selector_arm : public Target_selector
10836 Target_selector_arm()
10837 : Target_selector(elfcpp::EM_ARM, 32, big_endian,
10838 (big_endian ? "elf32-bigarm" : "elf32-littlearm"))
10842 do_instantiate_target()
10843 { return new Target_arm<big_endian>(); }
10846 // Fix .ARM.exidx section coverage.
10848 template<bool big_endian>
10850 Target_arm<big_endian>::fix_exidx_coverage(
10852 Arm_output_section<big_endian>* exidx_section,
10853 Symbol_table* symtab)
10855 // We need to look at all the input sections in output in ascending
10856 // order of of output address. We do that by building a sorted list
10857 // of output sections by addresses. Then we looks at the output sections
10858 // in order. The input sections in an output section are already sorted
10859 // by addresses within the output section.
10861 typedef std::set<Output_section*, output_section_address_less_than>
10862 Sorted_output_section_list;
10863 Sorted_output_section_list sorted_output_sections;
10864 Layout::Section_list section_list;
10865 layout->get_allocated_sections(§ion_list);
10866 for (Layout::Section_list::const_iterator p = section_list.begin();
10867 p != section_list.end();
10870 // We only care about output sections that contain executable code.
10871 if (((*p)->flags() & elfcpp::SHF_EXECINSTR) != 0)
10872 sorted_output_sections.insert(*p);
10875 // Go over the output sections in ascending order of output addresses.
10876 typedef typename Arm_output_section<big_endian>::Text_section_list
10878 Text_section_list sorted_text_sections;
10879 for(typename Sorted_output_section_list::iterator p =
10880 sorted_output_sections.begin();
10881 p != sorted_output_sections.end();
10884 Arm_output_section<big_endian>* arm_output_section =
10885 Arm_output_section<big_endian>::as_arm_output_section(*p);
10886 arm_output_section->append_text_sections_to_list(&sorted_text_sections);
10889 exidx_section->fix_exidx_coverage(layout, sorted_text_sections, symtab);
10892 Target_selector_arm<false> target_selector_arm;
10893 Target_selector_arm<true> target_selector_armbe;
10895 } // End anonymous namespace.