| // arm.cc -- arm target support for gold. |
| |
| // Copyright 2009 Free Software Foundation, Inc. |
| // Written by Doug Kwan <dougkwan@google.com> based on the i386 code |
| // by Ian Lance Taylor <iant@google.com>. |
| // This file also contains borrowed and adapted code from |
| // bfd/elf32-arm.c. |
| |
| // This file is part of gold. |
| |
| // This program is free software; you can redistribute it and/or modify |
| // it under the terms of the GNU General Public License as published by |
| // the Free Software Foundation; either version 3 of the License, or |
| // (at your option) any later version. |
| |
| // This program is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // You should have received a copy of the GNU General Public License |
| // along with this program; if not, write to the Free Software |
| // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, |
| // MA 02110-1301, USA. |
| |
| #include "gold.h" |
| |
| #include <cstring> |
| #include <limits> |
| #include <cstdio> |
| #include <string> |
| #include <algorithm> |
| |
| #include "elfcpp.h" |
| #include "parameters.h" |
| #include "reloc.h" |
| #include "arm.h" |
| #include "object.h" |
| #include "symtab.h" |
| #include "layout.h" |
| #include "output.h" |
| #include "copy-relocs.h" |
| #include "target.h" |
| #include "target-reloc.h" |
| #include "target-select.h" |
| #include "tls.h" |
| #include "defstd.h" |
| #include "gc.h" |
| #include "attributes.h" |
| |
| namespace |
| { |
| |
| using namespace gold; |
| |
| template<bool big_endian> |
| class Output_data_plt_arm; |
| |
| template<bool big_endian> |
| class Stub_table; |
| |
| template<bool big_endian> |
| class Arm_input_section; |
| |
| template<bool big_endian> |
| class Arm_output_section; |
| |
| template<bool big_endian> |
| class Arm_relobj; |
| |
| template<bool big_endian> |
| class Target_arm; |
| |
| // For convenience. |
| typedef elfcpp::Elf_types<32>::Elf_Addr Arm_address; |
| |
| // Maximum branch offsets for ARM, THUMB and THUMB2. |
| const int32_t ARM_MAX_FWD_BRANCH_OFFSET = ((((1 << 23) - 1) << 2) + 8); |
| const int32_t ARM_MAX_BWD_BRANCH_OFFSET = ((-((1 << 23) << 2)) + 8); |
| const int32_t THM_MAX_FWD_BRANCH_OFFSET = ((1 << 22) -2 + 4); |
| const int32_t THM_MAX_BWD_BRANCH_OFFSET = (-(1 << 22) + 4); |
| const int32_t THM2_MAX_FWD_BRANCH_OFFSET = (((1 << 24) - 2) + 4); |
| const int32_t THM2_MAX_BWD_BRANCH_OFFSET = (-(1 << 24) + 4); |
| |
| // The arm target class. |
| // |
| // This is a very simple port of gold for ARM-EABI. It is intended for |
| // supporting Android only for the time being. Only these relocation types |
| // are supported. |
| // |
| // R_ARM_NONE |
| // R_ARM_ABS32 |
| // R_ARM_ABS32_NOI |
| // R_ARM_ABS16 |
| // R_ARM_ABS12 |
| // R_ARM_ABS8 |
| // R_ARM_THM_ABS5 |
| // R_ARM_BASE_ABS |
| // R_ARM_REL32 |
| // R_ARM_THM_CALL |
| // R_ARM_COPY |
| // R_ARM_GLOB_DAT |
| // R_ARM_BASE_PREL |
| // R_ARM_JUMP_SLOT |
| // R_ARM_RELATIVE |
| // R_ARM_GOTOFF32 |
| // R_ARM_GOT_BREL |
| // R_ARM_GOT_PREL |
| // R_ARM_PLT32 |
| // R_ARM_CALL |
| // R_ARM_JUMP24 |
| // R_ARM_TARGET1 |
| // R_ARM_PREL31 |
| // R_ARM_ABS8 |
| // R_ARM_MOVW_ABS_NC |
| // R_ARM_MOVT_ABS |
| // R_ARM_THM_MOVW_ABS_NC |
| // R_ARM_THM_MOVT_ABS |
| // R_ARM_MOVW_PREL_NC |
| // R_ARM_MOVT_PREL |
| // R_ARM_THM_MOVW_PREL_NC |
| // R_ARM_THM_MOVT_PREL |
| // |
| // TODOs: |
| // - Support more relocation types as needed. |
| // - Make PLTs more flexible for different architecture features like |
| // Thumb-2 and BE8. |
| // There are probably a lot more. |
| |
| // Instruction template class. This class is similar to the insn_sequence |
| // struct in bfd/elf32-arm.c. |
| |
| class Insn_template |
| { |
| public: |
| // Types of instruction templates. |
| enum Type |
| { |
| THUMB16_TYPE = 1, |
| THUMB32_TYPE, |
| ARM_TYPE, |
| DATA_TYPE |
| }; |
| |
| // Factory methods to create instrunction templates in different formats. |
| |
| static const Insn_template |
| thumb16_insn(uint32_t data) |
| { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 0); } |
| |
| // A bit of a hack. A Thumb conditional branch, in which the proper |
| // condition is inserted when we build the stub. |
| static const Insn_template |
| thumb16_bcond_insn(uint32_t data) |
| { return Insn_template(data, THUMB16_TYPE, elfcpp::R_ARM_NONE, 1); } |
| |
| static const Insn_template |
| thumb32_insn(uint32_t data) |
| { return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_NONE, 0); } |
| |
| static const Insn_template |
| thumb32_b_insn(uint32_t data, int reloc_addend) |
| { |
| return Insn_template(data, THUMB32_TYPE, elfcpp::R_ARM_THM_JUMP24, |
| reloc_addend); |
| } |
| |
| static const Insn_template |
| arm_insn(uint32_t data) |
| { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_NONE, 0); } |
| |
| static const Insn_template |
| arm_rel_insn(unsigned data, int reloc_addend) |
| { return Insn_template(data, ARM_TYPE, elfcpp::R_ARM_JUMP24, reloc_addend); } |
| |
| static const Insn_template |
| data_word(unsigned data, unsigned int r_type, int reloc_addend) |
| { return Insn_template(data, DATA_TYPE, r_type, reloc_addend); } |
| |
| // Accessors. This class is used for read-only objects so no modifiers |
| // are provided. |
| |
| uint32_t |
| data() const |
| { return this->data_; } |
| |
| // Return the instruction sequence type of this. |
| Type |
| type() const |
| { return this->type_; } |
| |
| // Return the ARM relocation type of this. |
| unsigned int |
| r_type() const |
| { return this->r_type_; } |
| |
| int32_t |
| reloc_addend() const |
| { return this->reloc_addend_; } |
| |
| // Return size of instrunction template in bytes. |
| size_t |
| size() const; |
| |
| // Return byte-alignment of instrunction template. |
| unsigned |
| alignment() const; |
| |
| private: |
| // We make the constructor private to ensure that only the factory |
| // methods are used. |
| inline |
| Insn_template(unsigned data, Type type, unsigned int r_type, int reloc_addend) |
| : data_(data), type_(type), r_type_(r_type), reloc_addend_(reloc_addend) |
| { } |
| |
| // Instruction specific data. This is used to store information like |
| // some of the instruction bits. |
| uint32_t data_; |
| // Instruction template type. |
| Type type_; |
| // Relocation type if there is a relocation or R_ARM_NONE otherwise. |
| unsigned int r_type_; |
| // Relocation addend. |
| int32_t reloc_addend_; |
| }; |
| |
| // Macro for generating code to stub types. One entry per long/short |
| // branch stub |
| |
| #define DEF_STUBS \ |
| DEF_STUB(long_branch_any_any) \ |
| DEF_STUB(long_branch_v4t_arm_thumb) \ |
| DEF_STUB(long_branch_thumb_only) \ |
| DEF_STUB(long_branch_v4t_thumb_thumb) \ |
| DEF_STUB(long_branch_v4t_thumb_arm) \ |
| DEF_STUB(short_branch_v4t_thumb_arm) \ |
| DEF_STUB(long_branch_any_arm_pic) \ |
| DEF_STUB(long_branch_any_thumb_pic) \ |
| DEF_STUB(long_branch_v4t_thumb_thumb_pic) \ |
| DEF_STUB(long_branch_v4t_arm_thumb_pic) \ |
| DEF_STUB(long_branch_v4t_thumb_arm_pic) \ |
| DEF_STUB(long_branch_thumb_only_pic) \ |
| DEF_STUB(a8_veneer_b_cond) \ |
| DEF_STUB(a8_veneer_b) \ |
| DEF_STUB(a8_veneer_bl) \ |
| DEF_STUB(a8_veneer_blx) |
| |
| // Stub types. |
| |
| #define DEF_STUB(x) arm_stub_##x, |
| typedef enum |
| { |
| arm_stub_none, |
| DEF_STUBS |
| |
| // First reloc stub type. |
| arm_stub_reloc_first = arm_stub_long_branch_any_any, |
| // Last reloc stub type. |
| arm_stub_reloc_last = arm_stub_long_branch_thumb_only_pic, |
| |
| // First Cortex-A8 stub type. |
| arm_stub_cortex_a8_first = arm_stub_a8_veneer_b_cond, |
| // Last Cortex-A8 stub type. |
| arm_stub_cortex_a8_last = arm_stub_a8_veneer_blx, |
| |
| // Last stub type. |
| arm_stub_type_last = arm_stub_a8_veneer_blx |
| } Stub_type; |
| #undef DEF_STUB |
| |
| // Stub template class. Templates are meant to be read-only objects. |
| // A stub template for a stub type contains all read-only attributes |
| // common to all stubs of the same type. |
| |
| class Stub_template |
| { |
| public: |
| Stub_template(Stub_type, const Insn_template*, size_t); |
| |
| ~Stub_template() |
| { } |
| |
| // Return stub type. |
| Stub_type |
| type() const |
| { return this->type_; } |
| |
| // Return an array of instruction templates. |
| const Insn_template* |
| insns() const |
| { return this->insns_; } |
| |
| // Return size of template in number of instructions. |
| size_t |
| insn_count() const |
| { return this->insn_count_; } |
| |
| // Return size of template in bytes. |
| size_t |
| size() const |
| { return this->size_; } |
| |
| // Return alignment of the stub template. |
| unsigned |
| alignment() const |
| { return this->alignment_; } |
| |
| // Return whether entry point is in thumb mode. |
| bool |
| entry_in_thumb_mode() const |
| { return this->entry_in_thumb_mode_; } |
| |
| // Return number of relocations in this template. |
| size_t |
| reloc_count() const |
| { return this->relocs_.size(); } |
| |
| // Return index of the I-th instruction with relocation. |
| size_t |
| reloc_insn_index(size_t i) const |
| { |
| gold_assert(i < this->relocs_.size()); |
| return this->relocs_[i].first; |
| } |
| |
| // Return the offset of the I-th instruction with relocation from the |
| // beginning of the stub. |
| section_size_type |
| reloc_offset(size_t i) const |
| { |
| gold_assert(i < this->relocs_.size()); |
| return this->relocs_[i].second; |
| } |
| |
| private: |
| // This contains information about an instruction template with a relocation |
| // and its offset from start of stub. |
| typedef std::pair<size_t, section_size_type> Reloc; |
| |
| // A Stub_template may not be copied. We want to share templates as much |
| // as possible. |
| Stub_template(const Stub_template&); |
| Stub_template& operator=(const Stub_template&); |
| |
| // Stub type. |
| Stub_type type_; |
| // Points to an array of Insn_templates. |
| const Insn_template* insns_; |
| // Number of Insn_templates in insns_[]. |
| size_t insn_count_; |
| // Size of templated instructions in bytes. |
| size_t size_; |
| // Alignment of templated instructions. |
| unsigned alignment_; |
| // Flag to indicate if entry is in thumb mode. |
| bool entry_in_thumb_mode_; |
| // A table of reloc instruction indices and offsets. We can find these by |
| // looking at the instruction templates but we pre-compute and then stash |
| // them here for speed. |
| std::vector<Reloc> relocs_; |
| }; |
| |
| // |
| // A class for code stubs. This is a base class for different type of |
| // stubs used in the ARM target. |
| // |
| |
| class Stub |
| { |
| private: |
| static const section_offset_type invalid_offset = |
| static_cast<section_offset_type>(-1); |
| |
| public: |
| Stub(const Stub_template* stub_template) |
| : stub_template_(stub_template), offset_(invalid_offset) |
| { } |
| |
| virtual |
| ~Stub() |
| { } |
| |
| // Return the stub template. |
| const Stub_template* |
| stub_template() const |
| { return this->stub_template_; } |
| |
| // Return offset of code stub from beginning of its containing stub table. |
| section_offset_type |
| offset() const |
| { |
| gold_assert(this->offset_ != invalid_offset); |
| return this->offset_; |
| } |
| |
| // Set offset of code stub from beginning of its containing stub table. |
| void |
| set_offset(section_offset_type offset) |
| { this->offset_ = offset; } |
| |
| // Return the relocation target address of the i-th relocation in the |
| // stub. This must be defined in a child class. |
| Arm_address |
| reloc_target(size_t i) |
| { return this->do_reloc_target(i); } |
| |
| // Write a stub at output VIEW. BIG_ENDIAN select how a stub is written. |
| void |
| write(unsigned char* view, section_size_type view_size, bool big_endian) |
| { this->do_write(view, view_size, big_endian); } |
| |
| protected: |
| // This must be defined in the child class. |
| virtual Arm_address |
| do_reloc_target(size_t) = 0; |
| |
| // This must be defined in the child class. |
| virtual void |
| do_write(unsigned char*, section_size_type, bool) = 0; |
| |
| private: |
| // Its template. |
| const Stub_template* stub_template_; |
| // Offset within the section of containing this stub. |
| section_offset_type offset_; |
| }; |
| |
| // Reloc stub class. These are stubs we use to fix up relocation because |
| // of limited branch ranges. |
| |
| class Reloc_stub : public Stub |
| { |
| public: |
| static const unsigned int invalid_index = static_cast<unsigned int>(-1); |
| // We assume we never jump to this address. |
| static const Arm_address invalid_address = static_cast<Arm_address>(-1); |
| |
| // Return destination address. |
| Arm_address |
| destination_address() const |
| { |
| gold_assert(this->destination_address_ != this->invalid_address); |
| return this->destination_address_; |
| } |
| |
| // Set destination address. |
| void |
| set_destination_address(Arm_address address) |
| { |
| gold_assert(address != this->invalid_address); |
| this->destination_address_ = address; |
| } |
| |
| // Reset destination address. |
| void |
| reset_destination_address() |
| { this->destination_address_ = this->invalid_address; } |
| |
| // Determine stub type for a branch of a relocation of R_TYPE going |
| // from BRANCH_ADDRESS to BRANCH_TARGET. If TARGET_IS_THUMB is set, |
| // the branch target is a thumb instruction. TARGET is used for look |
| // up ARM-specific linker settings. |
| static Stub_type |
| stub_type_for_reloc(unsigned int r_type, Arm_address branch_address, |
| Arm_address branch_target, bool target_is_thumb); |
| |
| // Reloc_stub key. A key is logically a triplet of a stub type, a symbol |
| // and an addend. Since we treat global and local symbol differently, we |
| // use a Symbol object for a global symbol and a object-index pair for |
| // a local symbol. |
| class Key |
| { |
| public: |
| // If SYMBOL is not null, this is a global symbol, we ignore RELOBJ and |
| // R_SYM. Otherwise, this is a local symbol and RELOBJ must non-NULL |
| // and R_SYM must not be invalid_index. |
| Key(Stub_type stub_type, const Symbol* symbol, const Relobj* relobj, |
| unsigned int r_sym, int32_t addend) |
| : stub_type_(stub_type), addend_(addend) |
| { |
| if (symbol != NULL) |
| { |
| this->r_sym_ = Reloc_stub::invalid_index; |
| this->u_.symbol = symbol; |
| } |
| else |
| { |
| gold_assert(relobj != NULL && r_sym != invalid_index); |
| this->r_sym_ = r_sym; |
| this->u_.relobj = relobj; |
| } |
| } |
| |
| ~Key() |
| { } |
| |
| // Accessors: Keys are meant to be read-only object so no modifiers are |
| // provided. |
| |
| // Return stub type. |
| Stub_type |
| stub_type() const |
| { return this->stub_type_; } |
| |
| // Return the local symbol index or invalid_index. |
| unsigned int |
| r_sym() const |
| { return this->r_sym_; } |
| |
| // Return the symbol if there is one. |
| const Symbol* |
| symbol() const |
| { return this->r_sym_ == invalid_index ? this->u_.symbol : NULL; } |
| |
| // Return the relobj if there is one. |
| const Relobj* |
| relobj() const |
| { return this->r_sym_ != invalid_index ? this->u_.relobj : NULL; } |
| |
| // Whether this equals to another key k. |
| bool |
| eq(const Key& k) const |
| { |
| return ((this->stub_type_ == k.stub_type_) |
| && (this->r_sym_ == k.r_sym_) |
| && ((this->r_sym_ != Reloc_stub::invalid_index) |
| ? (this->u_.relobj == k.u_.relobj) |
| : (this->u_.symbol == k.u_.symbol)) |
| && (this->addend_ == k.addend_)); |
| } |
| |
| // Return a hash value. |
| size_t |
| hash_value() const |
| { |
| return (this->stub_type_ |
| ^ this->r_sym_ |
| ^ gold::string_hash<char>( |
| (this->r_sym_ != Reloc_stub::invalid_index) |
| ? this->u_.relobj->name().c_str() |
| : this->u_.symbol->name()) |
| ^ this->addend_); |
| } |
| |
| // Functors for STL associative containers. |
| struct hash |
| { |
| size_t |
| operator()(const Key& k) const |
| { return k.hash_value(); } |
| }; |
| |
| struct equal_to |
| { |
| bool |
| operator()(const Key& k1, const Key& k2) const |
| { return k1.eq(k2); } |
| }; |
| |
| // Name of key. This is mainly for debugging. |
| std::string |
| name() const; |
| |
| private: |
| // Stub type. |
| Stub_type stub_type_; |
| // If this is a local symbol, this is the index in the defining object. |
| // Otherwise, it is invalid_index for a global symbol. |
| unsigned int r_sym_; |
| // If r_sym_ is invalid index. This points to a global symbol. |
| // Otherwise, this points a relobj. We used the unsized and target |
| // independent Symbol and Relobj classes instead of Sized_symbol<32> and |
| // Arm_relobj. This is done to avoid making the stub class a template |
| // as most of the stub machinery is endianity-neutral. However, it |
| // may require a bit of casting done by users of this class. |
| union |
| { |
| const Symbol* symbol; |
| const Relobj* relobj; |
| } u_; |
| // Addend associated with a reloc. |
| int32_t addend_; |
| }; |
| |
| protected: |
| // Reloc_stubs are created via a stub factory. So these are protected. |
| Reloc_stub(const Stub_template* stub_template) |
| : Stub(stub_template), destination_address_(invalid_address) |
| { } |
| |
| ~Reloc_stub() |
| { } |
| |
| friend class Stub_factory; |
| |
| private: |
| // Return the relocation target address of the i-th relocation in the |
| // stub. |
| Arm_address |
| do_reloc_target(size_t i) |
| { |
| // All reloc stub have only one relocation. |
| gold_assert(i == 0); |
| return this->destination_address_; |
| } |
| |
| // A template to implement do_write below. |
| template<bool big_endian> |
| void inline |
| do_fixed_endian_write(unsigned char*, section_size_type); |
| |
| // Write a stub. |
| void |
| do_write(unsigned char* view, section_size_type view_size, bool big_endian); |
| |
| // Address of destination. |
| Arm_address destination_address_; |
| }; |
| |
| // Stub factory class. |
| |
| class Stub_factory |
| { |
| public: |
| // Return the unique instance of this class. |
| static const Stub_factory& |
| get_instance() |
| { |
| static Stub_factory singleton; |
| return singleton; |
| } |
| |
| // Make a relocation stub. |
| Reloc_stub* |
| make_reloc_stub(Stub_type stub_type) const |
| { |
| gold_assert(stub_type >= arm_stub_reloc_first |
| && stub_type <= arm_stub_reloc_last); |
| return new Reloc_stub(this->stub_templates_[stub_type]); |
| } |
| |
| private: |
| // Constructor and destructor are protected since we only return a single |
| // instance created in Stub_factory::get_instance(). |
| |
| Stub_factory(); |
| |
| // A Stub_factory may not be copied since it is a singleton. |
| Stub_factory(const Stub_factory&); |
| Stub_factory& operator=(Stub_factory&); |
| |
| // Stub templates. These are initialized in the constructor. |
| const Stub_template* stub_templates_[arm_stub_type_last+1]; |
| }; |
| |
| // A class to hold stubs for the ARM target. |
| |
| template<bool big_endian> |
| class Stub_table : public Output_data |
| { |
| public: |
| Stub_table(Arm_input_section<big_endian>* owner) |
| : Output_data(), addralign_(1), owner_(owner), has_been_changed_(false), |
| reloc_stubs_() |
| { } |
| |
| ~Stub_table() |
| { } |
| |
| // Owner of this stub table. |
| Arm_input_section<big_endian>* |
| owner() const |
| { return this->owner_; } |
| |
| // Whether this stub table is empty. |
| bool |
| empty() const |
| { return this->reloc_stubs_.empty(); } |
| |
| // Whether this has been changed. |
| bool |
| has_been_changed() const |
| { return this->has_been_changed_; } |
| |
| // Set the has-been-changed flag. |
| void |
| set_has_been_changed(bool value) |
| { this->has_been_changed_ = value; } |
| |
| // Return the current data size. |
| off_t |
| current_data_size() const |
| { return this->current_data_size_for_child(); } |
| |
| // Add a STUB with using KEY. Caller is reponsible for avoid adding |
| // if already a STUB with the same key has been added. |
| void |
| add_reloc_stub(Reloc_stub* stub, const Reloc_stub::Key& key); |
| |
| // Look up a relocation stub using KEY. Return NULL if there is none. |
| Reloc_stub* |
| find_reloc_stub(const Reloc_stub::Key& key) const |
| { |
| typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.find(key); |
| return (p != this->reloc_stubs_.end()) ? p->second : NULL; |
| } |
| |
| // Relocate stubs in this stub table. |
| void |
| relocate_stubs(const Relocate_info<32, big_endian>*, |
| Target_arm<big_endian>*, Output_section*, |
| unsigned char*, Arm_address, section_size_type); |
| |
| protected: |
| // Write out section contents. |
| void |
| do_write(Output_file*); |
| |
| // Return the required alignment. |
| uint64_t |
| do_addralign() const |
| { return this->addralign_; } |
| |
| // Finalize data size. |
| void |
| set_final_data_size() |
| { this->set_data_size(this->current_data_size_for_child()); } |
| |
| // Reset address and file offset. |
| void |
| do_reset_address_and_file_offset(); |
| |
| private: |
| // Unordered map of stubs. |
| typedef |
| Unordered_map<Reloc_stub::Key, Reloc_stub*, Reloc_stub::Key::hash, |
| Reloc_stub::Key::equal_to> |
| Reloc_stub_map; |
| |
| // Address alignment |
| uint64_t addralign_; |
| // Owner of this stub table. |
| Arm_input_section<big_endian>* owner_; |
| // This is set to true during relaxiong if the size of the stub table |
| // has been changed. |
| bool has_been_changed_; |
| // The relocation stubs. |
| Reloc_stub_map reloc_stubs_; |
| }; |
| |
| // A class to wrap an ordinary input section containing executable code. |
| |
| template<bool big_endian> |
| class Arm_input_section : public Output_relaxed_input_section |
| { |
| public: |
| Arm_input_section(Relobj* relobj, unsigned int shndx) |
| : Output_relaxed_input_section(relobj, shndx, 1), |
| original_addralign_(1), original_size_(0), stub_table_(NULL) |
| { } |
| |
| ~Arm_input_section() |
| { } |
| |
| // Initialize. |
| void |
| init(); |
| |
| // Whether this is a stub table owner. |
| bool |
| is_stub_table_owner() const |
| { return this->stub_table_ != NULL && this->stub_table_->owner() == this; } |
| |
| // Return the stub table. |
| Stub_table<big_endian>* |
| stub_table() const |
| { return this->stub_table_; } |
| |
| // Set the stub_table. |
| void |
| set_stub_table(Stub_table<big_endian>* stub_table) |
| { this->stub_table_ = stub_table; } |
| |
| // Downcast a base pointer to an Arm_input_section pointer. This is |
| // not type-safe but we only use Arm_input_section not the base class. |
| static Arm_input_section<big_endian>* |
| as_arm_input_section(Output_relaxed_input_section* poris) |
| { return static_cast<Arm_input_section<big_endian>*>(poris); } |
| |
| protected: |
| // Write data to output file. |
| void |
| do_write(Output_file*); |
| |
| // Return required alignment of this. |
| uint64_t |
| do_addralign() const |
| { |
| if (this->is_stub_table_owner()) |
| return std::max(this->stub_table_->addralign(), |
| this->original_addralign_); |
| else |
| return this->original_addralign_; |
| } |
| |
| // Finalize data size. |
| void |
| set_final_data_size(); |
| |
| // Reset address and file offset. |
| void |
| do_reset_address_and_file_offset(); |
| |
| // Output offset. |
| bool |
| do_output_offset(const Relobj* object, unsigned int shndx, |
| section_offset_type offset, |
| section_offset_type* poutput) const |
| { |
| if ((object == this->relobj()) |
| && (shndx == this->shndx()) |
| && (offset >= 0) |
| && (convert_types<uint64_t, section_offset_type>(offset) |
| <= this->original_size_)) |
| { |
| *poutput = offset; |
| return true; |
| } |
| else |
| return false; |
| } |
| |
| private: |
| // Copying is not allowed. |
| Arm_input_section(const Arm_input_section&); |
| Arm_input_section& operator=(const Arm_input_section&); |
| |
| // Address alignment of the original input section. |
| uint64_t original_addralign_; |
| // Section size of the original input section. |
| uint64_t original_size_; |
| // Stub table. |
| Stub_table<big_endian>* stub_table_; |
| }; |
| |
| // Arm output section class. This is defined mainly to add a number of |
| // stub generation methods. |
| |
| template<bool big_endian> |
| class Arm_output_section : public Output_section |
| { |
| public: |
| Arm_output_section(const char* name, elfcpp::Elf_Word type, |
| elfcpp::Elf_Xword flags) |
| : Output_section(name, type, flags) |
| { } |
| |
| ~Arm_output_section() |
| { } |
| |
| // Group input sections for stub generation. |
| void |
| group_sections(section_size_type, bool, Target_arm<big_endian>*); |
| |
| // Downcast a base pointer to an Arm_output_section pointer. This is |
| // not type-safe but we only use Arm_output_section not the base class. |
| static Arm_output_section<big_endian>* |
| as_arm_output_section(Output_section* os) |
| { return static_cast<Arm_output_section<big_endian>*>(os); } |
| |
| private: |
| // For convenience. |
| typedef Output_section::Input_section Input_section; |
| typedef Output_section::Input_section_list Input_section_list; |
| |
| // Create a stub group. |
| void create_stub_group(Input_section_list::const_iterator, |
| Input_section_list::const_iterator, |
| Input_section_list::const_iterator, |
| Target_arm<big_endian>*, |
| std::vector<Output_relaxed_input_section*>*); |
| }; |
| |
| // Arm_relobj class. |
| |
| template<bool big_endian> |
| class Arm_relobj : public Sized_relobj<32, big_endian> |
| { |
| public: |
| static const Arm_address invalid_address = static_cast<Arm_address>(-1); |
| |
| Arm_relobj(const std::string& name, Input_file* input_file, off_t offset, |
| const typename elfcpp::Ehdr<32, big_endian>& ehdr) |
| : Sized_relobj<32, big_endian>(name, input_file, offset, ehdr), |
| stub_tables_(), local_symbol_is_thumb_function_(), |
| attributes_section_data_(NULL) |
| { } |
| |
| ~Arm_relobj() |
| { delete this->attributes_section_data_; } |
| |
| // Return the stub table of the SHNDX-th section if there is one. |
| Stub_table<big_endian>* |
| stub_table(unsigned int shndx) const |
| { |
| gold_assert(shndx < this->stub_tables_.size()); |
| return this->stub_tables_[shndx]; |
| } |
| |
| // Set STUB_TABLE to be the stub_table of the SHNDX-th section. |
| void |
| set_stub_table(unsigned int shndx, Stub_table<big_endian>* stub_table) |
| { |
| gold_assert(shndx < this->stub_tables_.size()); |
| this->stub_tables_[shndx] = stub_table; |
| } |
| |
| // Whether a local symbol is a THUMB function. R_SYM is the symbol table |
| // index. This is only valid after do_count_local_symbol is called. |
| bool |
| local_symbol_is_thumb_function(unsigned int r_sym) const |
| { |
| gold_assert(r_sym < this->local_symbol_is_thumb_function_.size()); |
| return this->local_symbol_is_thumb_function_[r_sym]; |
| } |
| |
| // Scan all relocation sections for stub generation. |
| void |
| scan_sections_for_stubs(Target_arm<big_endian>*, const Symbol_table*, |
| const Layout*); |
| |
| // Convert regular input section with index SHNDX to a relaxed section. |
| void |
| convert_input_section_to_relaxed_section(unsigned shndx) |
| { |
| // The stubs have relocations and we need to process them after writing |
| // out the stubs. So relocation now must follow section write. |
| this->invalidate_section_offset(shndx); |
| this->set_relocs_must_follow_section_writes(); |
| } |
| |
| // Downcast a base pointer to an Arm_relobj pointer. This is |
| // not type-safe but we only use Arm_relobj not the base class. |
| static Arm_relobj<big_endian>* |
| as_arm_relobj(Relobj* relobj) |
| { return static_cast<Arm_relobj<big_endian>*>(relobj); } |
| |
| // Processor-specific flags in ELF file header. This is valid only after |
| // reading symbols. |
| elfcpp::Elf_Word |
| processor_specific_flags() const |
| { return this->processor_specific_flags_; } |
| |
| // Attribute section data This is the contents of the .ARM.attribute section |
| // if there is one. |
| const Attributes_section_data* |
| attributes_section_data() const |
| { return this->attributes_section_data_; } |
| |
| protected: |
| // Post constructor setup. |
| void |
| do_setup() |
| { |
| // Call parent's setup method. |
| Sized_relobj<32, big_endian>::do_setup(); |
| |
| // Initialize look-up tables. |
| Stub_table_list empty_stub_table_list(this->shnum(), NULL); |
| this->stub_tables_.swap(empty_stub_table_list); |
| } |
| |
| // Count the local symbols. |
| void |
| do_count_local_symbols(Stringpool_template<char>*, |
| Stringpool_template<char>*); |
| |
| void |
| do_relocate_sections(const Symbol_table* symtab, const Layout* layout, |
| const unsigned char* pshdrs, |
| typename Sized_relobj<32, big_endian>::Views* pivews); |
| |
| // Read the symbol information. |
| void |
| do_read_symbols(Read_symbols_data* sd); |
| |
| private: |
| // List of stub tables. |
| typedef std::vector<Stub_table<big_endian>*> Stub_table_list; |
| Stub_table_list stub_tables_; |
| // Bit vector to tell if a local symbol is a thumb function or not. |
| // This is only valid after do_count_local_symbol is called. |
| std::vector<bool> local_symbol_is_thumb_function_; |
| // processor-specific flags in ELF file header. |
| elfcpp::Elf_Word processor_specific_flags_; |
| // Object attributes if there is an .ARM.attributes section or NULL. |
| Attributes_section_data* attributes_section_data_; |
| }; |
| |
| // Arm_dynobj class. |
| |
| template<bool big_endian> |
| class Arm_dynobj : public Sized_dynobj<32, big_endian> |
| { |
| public: |
| Arm_dynobj(const std::string& name, Input_file* input_file, off_t offset, |
| const elfcpp::Ehdr<32, big_endian>& ehdr) |
| : Sized_dynobj<32, big_endian>(name, input_file, offset, ehdr), |
| processor_specific_flags_(0), attributes_section_data_(NULL) |
| { } |
| |
| ~Arm_dynobj() |
| { delete this->attributes_section_data_; } |
| |
| // Downcast a base pointer to an Arm_relobj pointer. This is |
| // not type-safe but we only use Arm_relobj not the base class. |
| static Arm_dynobj<big_endian>* |
| as_arm_dynobj(Dynobj* dynobj) |
| { return static_cast<Arm_dynobj<big_endian>*>(dynobj); } |
| |
| // Processor-specific flags in ELF file header. This is valid only after |
| // reading symbols. |
| elfcpp::Elf_Word |
| processor_specific_flags() const |
| { return this->processor_specific_flags_; } |
| |
| // Attributes section data. |
| const Attributes_section_data* |
| attributes_section_data() const |
| { return this->attributes_section_data_; } |
| |
| protected: |
| // Read the symbol information. |
| void |
| do_read_symbols(Read_symbols_data* sd); |
| |
| private: |
| // processor-specific flags in ELF file header. |
| elfcpp::Elf_Word processor_specific_flags_; |
| // Object attributes if there is an .ARM.attributes section or NULL. |
| Attributes_section_data* attributes_section_data_; |
| }; |
| |
| // Functor to read reloc addends during stub generation. |
| |
| template<int sh_type, bool big_endian> |
| struct Stub_addend_reader |
| { |
| // Return the addend for a relocation of a particular type. Depending |
| // on whether this is a REL or RELA relocation, read the addend from a |
| // view or from a Reloc object. |
| elfcpp::Elf_types<32>::Elf_Swxword |
| operator()( |
| unsigned int /* r_type */, |
| const unsigned char* /* view */, |
| const typename Reloc_types<sh_type, |
| 32, big_endian>::Reloc& /* reloc */) const; |
| }; |
| |
| // Specialized Stub_addend_reader for SHT_REL type relocation sections. |
| |
| template<bool big_endian> |
| struct Stub_addend_reader<elfcpp::SHT_REL, big_endian> |
| { |
| elfcpp::Elf_types<32>::Elf_Swxword |
| operator()( |
| unsigned int, |
| const unsigned char*, |
| const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const; |
| }; |
| |
| // Specialized Stub_addend_reader for RELA type relocation sections. |
| // We currently do not handle RELA type relocation sections but it is trivial |
| // to implement the addend reader. This is provided for completeness and to |
| // make it easier to add support for RELA relocation sections in the future. |
| |
| template<bool big_endian> |
| struct Stub_addend_reader<elfcpp::SHT_RELA, big_endian> |
| { |
| elfcpp::Elf_types<32>::Elf_Swxword |
| operator()( |
| unsigned int, |
| const unsigned char*, |
| const typename Reloc_types<elfcpp::SHT_RELA, 32, |
| big_endian>::Reloc& reloc) const |
| { return reloc.get_r_addend(); } |
| }; |
| |
| // Utilities for manipulating integers of up to 32-bits |
| |
| namespace utils |
| { |
| // Sign extend an n-bit unsigned integer stored in an uint32_t into |
| // an int32_t. NO_BITS must be between 1 to 32. |
| template<int no_bits> |
| static inline int32_t |
| sign_extend(uint32_t bits) |
| { |
| gold_assert(no_bits >= 0 && no_bits <= 32); |
| if (no_bits == 32) |
| return static_cast<int32_t>(bits); |
| uint32_t mask = (~((uint32_t) 0)) >> (32 - no_bits); |
| bits &= mask; |
| uint32_t top_bit = 1U << (no_bits - 1); |
| int32_t as_signed = static_cast<int32_t>(bits); |
| return (bits & top_bit) ? as_signed + (-top_bit * 2) : as_signed; |
| } |
| |
| // Detects overflow of an NO_BITS integer stored in a uint32_t. |
| template<int no_bits> |
| static inline bool |
| has_overflow(uint32_t bits) |
| { |
| gold_assert(no_bits >= 0 && no_bits <= 32); |
| if (no_bits == 32) |
| return false; |
| int32_t max = (1 << (no_bits - 1)) - 1; |
| int32_t min = -(1 << (no_bits - 1)); |
| int32_t as_signed = static_cast<int32_t>(bits); |
| return as_signed > max || as_signed < min; |
| } |
| |
| // Detects overflow of an NO_BITS integer stored in a uint32_t when it |
| // fits in the given number of bits as either a signed or unsigned value. |
| // For example, has_signed_unsigned_overflow<8> would check |
| // -128 <= bits <= 255 |
| template<int no_bits> |
| static inline bool |
| has_signed_unsigned_overflow(uint32_t bits) |
| { |
| gold_assert(no_bits >= 2 && no_bits <= 32); |
| if (no_bits == 32) |
| return false; |
| int32_t max = static_cast<int32_t>((1U << no_bits) - 1); |
| int32_t min = -(1 << (no_bits - 1)); |
| int32_t as_signed = static_cast<int32_t>(bits); |
| return as_signed > max || as_signed < min; |
| } |
| |
| // Select bits from A and B using bits in MASK. For each n in [0..31], |
| // the n-th bit in the result is chosen from the n-th bits of A and B. |
| // A zero selects A and a one selects B. |
| static inline uint32_t |
| bit_select(uint32_t a, uint32_t b, uint32_t mask) |
| { return (a & ~mask) | (b & mask); } |
| }; |
| |
| template<bool big_endian> |
| class Target_arm : public Sized_target<32, big_endian> |
| { |
| public: |
| typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian> |
| Reloc_section; |
| |
| // When were are relocating a stub, we pass this as the relocation number. |
| static const size_t fake_relnum_for_stubs = static_cast<size_t>(-1); |
| |
| Target_arm() |
| : Sized_target<32, big_endian>(&arm_info), |
| got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), |
| copy_relocs_(elfcpp::R_ARM_COPY), dynbss_(NULL), stub_tables_(), |
| stub_factory_(Stub_factory::get_instance()), may_use_blx_(false), |
| should_force_pic_veneer_(false), arm_input_section_map_(), |
| attributes_section_data_(NULL) |
| { } |
| |
| // Whether we can use BLX. |
| bool |
| may_use_blx() const |
| { return this->may_use_blx_; } |
| |
| // Set use-BLX flag. |
| void |
| set_may_use_blx(bool value) |
| { this->may_use_blx_ = value; } |
| |
| // Whether we force PCI branch veneers. |
| bool |
| should_force_pic_veneer() const |
| { return this->should_force_pic_veneer_; } |
| |
| // Set PIC veneer flag. |
| void |
| set_should_force_pic_veneer(bool value) |
| { this->should_force_pic_veneer_ = value; } |
| |
| // Whether we use THUMB-2 instructions. |
| bool |
| using_thumb2() const |
| { |
| Object_attribute* attr = |
| this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
| int arch = attr->int_value(); |
| return arch == elfcpp::TAG_CPU_ARCH_V6T2 || arch >= elfcpp::TAG_CPU_ARCH_V7; |
| } |
| |
| // Whether we use THUMB/THUMB-2 instructions only. |
| bool |
| using_thumb_only() const |
| { |
| Object_attribute* attr = |
| this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
| if (attr->int_value() != elfcpp::TAG_CPU_ARCH_V7 |
| && attr->int_value() != elfcpp::TAG_CPU_ARCH_V7E_M) |
| return false; |
| attr = this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch_profile); |
| return attr->int_value() == 'M'; |
| } |
| |
| // Whether we have an NOP instruction. If not, use mov r0, r0 instead. |
| bool |
| may_use_arm_nop() const |
| { |
| Object_attribute* attr = |
| this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
| int arch = attr->int_value(); |
| return (arch == elfcpp::TAG_CPU_ARCH_V6T2 |
| || arch == elfcpp::TAG_CPU_ARCH_V6K |
| || arch == elfcpp::TAG_CPU_ARCH_V7 |
| || arch == elfcpp::TAG_CPU_ARCH_V7E_M); |
| } |
| |
| // Whether we have THUMB-2 NOP.W instruction. |
| bool |
| may_use_thumb2_nop() const |
| { |
| Object_attribute* attr = |
| this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
| int arch = attr->int_value(); |
| return (arch == elfcpp::TAG_CPU_ARCH_V6T2 |
| || arch == elfcpp::TAG_CPU_ARCH_V7 |
| || arch == elfcpp::TAG_CPU_ARCH_V7E_M); |
| } |
| |
| // Process the relocations to determine unreferenced sections for |
| // garbage collection. |
| void |
| gc_process_relocs(Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| size_t local_symbol_count, |
| const unsigned char* plocal_symbols); |
| |
| // Scan the relocations to look for symbol adjustments. |
| void |
| scan_relocs(Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| size_t local_symbol_count, |
| const unsigned char* plocal_symbols); |
| |
| // Finalize the sections. |
| void |
| do_finalize_sections(Layout*, const Input_objects*, Symbol_table*); |
| |
| // Return the value to use for a dynamic symbol which requires special |
| // treatment. |
| uint64_t |
| do_dynsym_value(const Symbol*) const; |
| |
| // Relocate a section. |
| void |
| relocate_section(const Relocate_info<32, big_endian>*, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| unsigned char* view, |
| Arm_address view_address, |
| section_size_type view_size, |
| const Reloc_symbol_changes*); |
| |
| // Scan the relocs during a relocatable link. |
| void |
| scan_relocatable_relocs(Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| size_t local_symbol_count, |
| const unsigned char* plocal_symbols, |
| Relocatable_relocs*); |
| |
| // Relocate a section during a relocatable link. |
| void |
| relocate_for_relocatable(const Relocate_info<32, big_endian>*, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| off_t offset_in_output_section, |
| const Relocatable_relocs*, |
| unsigned char* view, |
| Arm_address view_address, |
| section_size_type view_size, |
| unsigned char* reloc_view, |
| section_size_type reloc_view_size); |
| |
| // Return whether SYM is defined by the ABI. |
| bool |
| do_is_defined_by_abi(Symbol* sym) const |
| { return strcmp(sym->name(), "__tls_get_addr") == 0; } |
| |
| // Return the size of the GOT section. |
| section_size_type |
| got_size() |
| { |
| gold_assert(this->got_ != NULL); |
| return this->got_->data_size(); |
| } |
| |
| // Map platform-specific reloc types |
| static unsigned int |
| get_real_reloc_type (unsigned int r_type); |
| |
| // |
| // Methods to support stub-generations. |
| // |
| |
| // Return the stub factory |
| const Stub_factory& |
| stub_factory() const |
| { return this->stub_factory_; } |
| |
| // Make a new Arm_input_section object. |
| Arm_input_section<big_endian>* |
| new_arm_input_section(Relobj*, unsigned int); |
| |
| // Find the Arm_input_section object corresponding to the SHNDX-th input |
| // section of RELOBJ. |
| Arm_input_section<big_endian>* |
| find_arm_input_section(Relobj* relobj, unsigned int shndx) const; |
| |
| // Make a new Stub_table |
| Stub_table<big_endian>* |
| new_stub_table(Arm_input_section<big_endian>*); |
| |
| // Scan a section for stub generation. |
| void |
| scan_section_for_stubs(const Relocate_info<32, big_endian>*, unsigned int, |
| const unsigned char*, size_t, Output_section*, |
| bool, const unsigned char*, Arm_address, |
| section_size_type); |
| |
| // Relocate a stub. |
| void |
| relocate_stub(Reloc_stub*, const Relocate_info<32, big_endian>*, |
| Output_section*, unsigned char*, Arm_address, |
| section_size_type); |
| |
| // Get the default ARM target. |
| static Target_arm<big_endian>* |
| default_target() |
| { |
| gold_assert(parameters->target().machine_code() == elfcpp::EM_ARM |
| && parameters->target().is_big_endian() == big_endian); |
| return static_cast<Target_arm<big_endian>*>( |
| parameters->sized_target<32, big_endian>()); |
| } |
| |
| // Whether relocation type uses LSB to distinguish THUMB addresses. |
| static bool |
| reloc_uses_thumb_bit(unsigned int r_type); |
| |
| protected: |
| // Make an ELF object. |
| Object* |
| do_make_elf_object(const std::string&, Input_file*, off_t, |
| const elfcpp::Ehdr<32, big_endian>& ehdr); |
| |
| Object* |
| do_make_elf_object(const std::string&, Input_file*, off_t, |
| const elfcpp::Ehdr<32, !big_endian>&) |
| { gold_unreachable(); } |
| |
| Object* |
| do_make_elf_object(const std::string&, Input_file*, off_t, |
| const elfcpp::Ehdr<64, false>&) |
| { gold_unreachable(); } |
| |
| Object* |
| do_make_elf_object(const std::string&, Input_file*, off_t, |
| const elfcpp::Ehdr<64, true>&) |
| { gold_unreachable(); } |
| |
| // Make an output section. |
| Output_section* |
| do_make_output_section(const char* name, elfcpp::Elf_Word type, |
| elfcpp::Elf_Xword flags) |
| { return new Arm_output_section<big_endian>(name, type, flags); } |
| |
| void |
| do_adjust_elf_header(unsigned char* view, int len) const; |
| |
| // We only need to generate stubs, and hence perform relaxation if we are |
| // not doing relocatable linking. |
| bool |
| do_may_relax() const |
| { return !parameters->options().relocatable(); } |
| |
| bool |
| do_relax(int, const Input_objects*, Symbol_table*, Layout*); |
| |
| // Determine whether an object attribute tag takes an integer, a |
| // string or both. |
| int |
| do_attribute_arg_type(int tag) const; |
| |
| // Reorder tags during output. |
| int |
| do_attributes_order(int num) const; |
| |
| private: |
| // The class which scans relocations. |
| class Scan |
| { |
| public: |
| Scan() |
| : issued_non_pic_error_(false) |
| { } |
| |
| inline void |
| local(Symbol_table* symtab, Layout* layout, Target_arm* target, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| Output_section* output_section, |
| const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, |
| const elfcpp::Sym<32, big_endian>& lsym); |
| |
| inline void |
| global(Symbol_table* symtab, Layout* layout, Target_arm* target, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| Output_section* output_section, |
| const elfcpp::Rel<32, big_endian>& reloc, unsigned int r_type, |
| Symbol* gsym); |
| |
| private: |
| static void |
| unsupported_reloc_local(Sized_relobj<32, big_endian>*, |
| unsigned int r_type); |
| |
| static void |
| unsupported_reloc_global(Sized_relobj<32, big_endian>*, |
| unsigned int r_type, Symbol*); |
| |
| void |
| check_non_pic(Relobj*, unsigned int r_type); |
| |
| // Almost identical to Symbol::needs_plt_entry except that it also |
| // handles STT_ARM_TFUNC. |
| static bool |
| symbol_needs_plt_entry(const Symbol* sym) |
| { |
| // An undefined symbol from an executable does not need a PLT entry. |
| if (sym->is_undefined() && !parameters->options().shared()) |
| return false; |
| |
| return (!parameters->doing_static_link() |
| && (sym->type() == elfcpp::STT_FUNC |
| || sym->type() == elfcpp::STT_ARM_TFUNC) |
| && (sym->is_from_dynobj() |
| || sym->is_undefined() |
| || sym->is_preemptible())); |
| } |
| |
| // Whether we have issued an error about a non-PIC compilation. |
| bool issued_non_pic_error_; |
| }; |
| |
| // The class which implements relocation. |
| class Relocate |
| { |
| public: |
| Relocate() |
| { } |
| |
| ~Relocate() |
| { } |
| |
| // Return whether the static relocation needs to be applied. |
| inline bool |
| should_apply_static_reloc(const Sized_symbol<32>* gsym, |
| int ref_flags, |
| bool is_32bit, |
| Output_section* output_section); |
| |
| // Do a relocation. Return false if the caller should not issue |
| // any warnings about this relocation. |
| inline bool |
| relocate(const Relocate_info<32, big_endian>*, Target_arm*, |
| Output_section*, size_t relnum, |
| const elfcpp::Rel<32, big_endian>&, |
| unsigned int r_type, const Sized_symbol<32>*, |
| const Symbol_value<32>*, |
| unsigned char*, Arm_address, |
| section_size_type); |
| |
| // Return whether we want to pass flag NON_PIC_REF for this |
| // reloc. This means the relocation type accesses a symbol not via |
| // GOT or PLT. |
| static inline bool |
| reloc_is_non_pic (unsigned int r_type) |
| { |
| switch (r_type) |
| { |
| // These relocation types reference GOT or PLT entries explicitly. |
| case elfcpp::R_ARM_GOT_BREL: |
| case elfcpp::R_ARM_GOT_ABS: |
| case elfcpp::R_ARM_GOT_PREL: |
| case elfcpp::R_ARM_GOT_BREL12: |
| case elfcpp::R_ARM_PLT32_ABS: |
| case elfcpp::R_ARM_TLS_GD32: |
| case elfcpp::R_ARM_TLS_LDM32: |
| case elfcpp::R_ARM_TLS_IE32: |
| case elfcpp::R_ARM_TLS_IE12GP: |
| |
| // These relocate types may use PLT entries. |
| case elfcpp::R_ARM_CALL: |
| case elfcpp::R_ARM_THM_CALL: |
| case elfcpp::R_ARM_JUMP24: |
| case elfcpp::R_ARM_THM_JUMP24: |
| case elfcpp::R_ARM_THM_JUMP19: |
| case elfcpp::R_ARM_PLT32: |
| case elfcpp::R_ARM_THM_XPC22: |
| return false; |
| |
| default: |
| return true; |
| } |
| } |
| }; |
| |
| // A class which returns the size required for a relocation type, |
| // used while scanning relocs during a relocatable link. |
| class Relocatable_size_for_reloc |
| { |
| public: |
| unsigned int |
| get_size_for_reloc(unsigned int, Relobj*); |
| }; |
| |
| // Get the GOT section, creating it if necessary. |
| Output_data_got<32, big_endian>* |
| got_section(Symbol_table*, Layout*); |
| |
| // Get the GOT PLT section. |
| Output_data_space* |
| got_plt_section() const |
| { |
| gold_assert(this->got_plt_ != NULL); |
| return this->got_plt_; |
| } |
| |
| // Create a PLT entry for a global symbol. |
| void |
| make_plt_entry(Symbol_table*, Layout*, Symbol*); |
| |
| // Get the PLT section. |
| const Output_data_plt_arm<big_endian>* |
| plt_section() const |
| { |
| gold_assert(this->plt_ != NULL); |
| return this->plt_; |
| } |
| |
| // Get the dynamic reloc section, creating it if necessary. |
| Reloc_section* |
| rel_dyn_section(Layout*); |
| |
| // Return true if the symbol may need a COPY relocation. |
| // References from an executable object to non-function symbols |
| // defined in a dynamic object may need a COPY relocation. |
| bool |
| may_need_copy_reloc(Symbol* gsym) |
| { |
| return (gsym->type() != elfcpp::STT_ARM_TFUNC |
| && gsym->may_need_copy_reloc()); |
| } |
| |
| // Add a potential copy relocation. |
| void |
| copy_reloc(Symbol_table* symtab, Layout* layout, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int shndx, Output_section* output_section, |
| Symbol* sym, const elfcpp::Rel<32, big_endian>& reloc) |
| { |
| this->copy_relocs_.copy_reloc(symtab, layout, |
| symtab->get_sized_symbol<32>(sym), |
| object, shndx, output_section, reloc, |
| this->rel_dyn_section(layout)); |
| } |
| |
| // Whether two EABI versions are compatible. |
| static bool |
| are_eabi_versions_compatible(elfcpp::Elf_Word v1, elfcpp::Elf_Word v2); |
| |
| // Merge processor-specific flags from input object and those in the ELF |
| // header of the output. |
| void |
| merge_processor_specific_flags(const std::string&, elfcpp::Elf_Word); |
| |
| // Get the secondary compatible architecture. |
| static int |
| get_secondary_compatible_arch(const Attributes_section_data*); |
| |
| // Set the secondary compatible architecture. |
| static void |
| set_secondary_compatible_arch(Attributes_section_data*, int); |
| |
| static int |
| tag_cpu_arch_combine(const char*, int, int*, int, int); |
| |
| // Helper to print AEABI enum tag value. |
| static std::string |
| aeabi_enum_name(unsigned int); |
| |
| // Return string value for TAG_CPU_name. |
| static std::string |
| tag_cpu_name_value(unsigned int); |
| |
| // Merge object attributes from input object and those in the output. |
| void |
| merge_object_attributes(const char*, const Attributes_section_data*); |
| |
| // Helper to get an AEABI object attribute |
| Object_attribute* |
| get_aeabi_object_attribute(int tag) const |
| { |
| Attributes_section_data* pasd = this->attributes_section_data_; |
| gold_assert(pasd != NULL); |
| Object_attribute* attr = |
| pasd->get_attribute(Object_attribute::OBJ_ATTR_PROC, tag); |
| gold_assert(attr != NULL); |
| return attr; |
| } |
| |
| // |
| // Methods to support stub-generations. |
| // |
| |
| // Group input sections for stub generation. |
| void |
| group_sections(Layout*, section_size_type, bool); |
| |
| // Scan a relocation for stub generation. |
| void |
| scan_reloc_for_stub(const Relocate_info<32, big_endian>*, unsigned int, |
| const Sized_symbol<32>*, unsigned int, |
| const Symbol_value<32>*, |
| elfcpp::Elf_types<32>::Elf_Swxword, Arm_address); |
| |
| // Scan a relocation section for stub. |
| template<int sh_type> |
| void |
| scan_reloc_section_for_stubs( |
| const Relocate_info<32, big_endian>* relinfo, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| const unsigned char* view, |
| elfcpp::Elf_types<32>::Elf_Addr view_address, |
| section_size_type); |
| |
| // Information about this specific target which we pass to the |
| // general Target structure. |
| static const Target::Target_info arm_info; |
| |
| // The types of GOT entries needed for this platform. |
| enum Got_type |
| { |
| GOT_TYPE_STANDARD = 0 // GOT entry for a regular symbol |
| }; |
| |
| typedef typename std::vector<Stub_table<big_endian>*> Stub_table_list; |
| |
| // Map input section to Arm_input_section. |
| typedef Unordered_map<Input_section_specifier, |
| Arm_input_section<big_endian>*, |
| Input_section_specifier::hash, |
| Input_section_specifier::equal_to> |
| Arm_input_section_map; |
| |
| // The GOT section. |
| Output_data_got<32, big_endian>* got_; |
| // The PLT section. |
| Output_data_plt_arm<big_endian>* plt_; |
| // The GOT PLT section. |
| Output_data_space* got_plt_; |
| // The dynamic reloc section. |
| Reloc_section* rel_dyn_; |
| // Relocs saved to avoid a COPY reloc. |
| Copy_relocs<elfcpp::SHT_REL, 32, big_endian> copy_relocs_; |
| // Space for variables copied with a COPY reloc. |
| Output_data_space* dynbss_; |
| // Vector of Stub_tables created. |
| Stub_table_list stub_tables_; |
| // Stub factory. |
| const Stub_factory &stub_factory_; |
| // Whether we can use BLX. |
| bool may_use_blx_; |
| // Whether we force PIC branch veneers. |
| bool should_force_pic_veneer_; |
| // Map for locating Arm_input_sections. |
| Arm_input_section_map arm_input_section_map_; |
| // Attributes section data in output. |
| Attributes_section_data* attributes_section_data_; |
| }; |
| |
| template<bool big_endian> |
| const Target::Target_info Target_arm<big_endian>::arm_info = |
| { |
| 32, // size |
| big_endian, // is_big_endian |
| elfcpp::EM_ARM, // machine_code |
| false, // has_make_symbol |
| false, // has_resolve |
| false, // has_code_fill |
| true, // is_default_stack_executable |
| '\0', // wrap_char |
| "/usr/lib/libc.so.1", // dynamic_linker |
| 0x8000, // default_text_segment_address |
| 0x1000, // abi_pagesize (overridable by -z max-page-size) |
| 0x1000, // common_pagesize (overridable by -z common-page-size) |
| elfcpp::SHN_UNDEF, // small_common_shndx |
| elfcpp::SHN_UNDEF, // large_common_shndx |
| 0, // small_common_section_flags |
| 0, // large_common_section_flags |
| ".ARM.attributes", // attributes_section |
| "aeabi" // attributes_vendor |
| }; |
| |
| // Arm relocate functions class |
| // |
| |
| template<bool big_endian> |
| class Arm_relocate_functions : public Relocate_functions<32, big_endian> |
| { |
| public: |
| typedef enum |
| { |
| STATUS_OKAY, // No error during relocation. |
| STATUS_OVERFLOW, // Relocation oveflow. |
| STATUS_BAD_RELOC // Relocation cannot be applied. |
| } Status; |
| |
| private: |
| typedef Relocate_functions<32, big_endian> Base; |
| typedef Arm_relocate_functions<big_endian> This; |
| |
| // Encoding of imm16 argument for movt and movw ARM instructions |
| // from ARM ARM: |
| // |
| // imm16 := imm4 | imm12 |
| // |
| // 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 |
| // +-------+---------------+-------+-------+-----------------------+ |
| // | | |imm4 | |imm12 | |
| // +-------+---------------+-------+-------+-----------------------+ |
| |
| // Extract the relocation addend from VAL based on the ARM |
| // instruction encoding described above. |
| static inline typename elfcpp::Swap<32, big_endian>::Valtype |
| extract_arm_movw_movt_addend( |
| typename elfcpp::Swap<32, big_endian>::Valtype val) |
| { |
| // According to the Elf ABI for ARM Architecture the immediate |
| // field is sign-extended to form the addend. |
| return utils::sign_extend<16>(((val >> 4) & 0xf000) | (val & 0xfff)); |
| } |
| |
| // Insert X into VAL based on the ARM instruction encoding described |
| // above. |
| static inline typename elfcpp::Swap<32, big_endian>::Valtype |
| insert_val_arm_movw_movt( |
| typename elfcpp::Swap<32, big_endian>::Valtype val, |
| typename elfcpp::Swap<32, big_endian>::Valtype x) |
| { |
| val &= 0xfff0f000; |
| val |= x & 0x0fff; |
| val |= (x & 0xf000) << 4; |
| return val; |
| } |
| |
| // Encoding of imm16 argument for movt and movw Thumb2 instructions |
| // from ARM ARM: |
| // |
| // imm16 := imm4 | i | imm3 | imm8 |
| // |
| // 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 |
| // +---------+-+-----------+-------++-+-----+-------+---------------+ |
| // | |i| |imm4 || |imm3 | |imm8 | |
| // +---------+-+-----------+-------++-+-----+-------+---------------+ |
| |
| // Extract the relocation addend from VAL based on the Thumb2 |
| // instruction encoding described above. |
| static inline typename elfcpp::Swap<32, big_endian>::Valtype |
| extract_thumb_movw_movt_addend( |
| typename elfcpp::Swap<32, big_endian>::Valtype val) |
| { |
| // According to the Elf ABI for ARM Architecture the immediate |
| // field is sign-extended to form the addend. |
| return utils::sign_extend<16>(((val >> 4) & 0xf000) |
| | ((val >> 15) & 0x0800) |
| | ((val >> 4) & 0x0700) |
| | (val & 0x00ff)); |
| } |
| |
| // Insert X into VAL based on the Thumb2 instruction encoding |
| // described above. |
| static inline typename elfcpp::Swap<32, big_endian>::Valtype |
| insert_val_thumb_movw_movt( |
| typename elfcpp::Swap<32, big_endian>::Valtype val, |
| typename elfcpp::Swap<32, big_endian>::Valtype x) |
| { |
| val &= 0xfbf08f00; |
| val |= (x & 0xf000) << 4; |
| val |= (x & 0x0800) << 15; |
| val |= (x & 0x0700) << 4; |
| val |= (x & 0x00ff); |
| return val; |
| } |
| |
| // Handle ARM long branches. |
| static typename This::Status |
| arm_branch_common(unsigned int, const Relocate_info<32, big_endian>*, |
| unsigned char *, const Sized_symbol<32>*, |
| const Arm_relobj<big_endian>*, unsigned int, |
| const Symbol_value<32>*, Arm_address, Arm_address, bool); |
| |
| // Handle THUMB long branches. |
| static typename This::Status |
| thumb_branch_common(unsigned int, const Relocate_info<32, big_endian>*, |
| unsigned char *, const Sized_symbol<32>*, |
| const Arm_relobj<big_endian>*, unsigned int, |
| const Symbol_value<32>*, Arm_address, Arm_address, bool); |
| |
| public: |
| |
| // R_ARM_ABS8: S + A |
| static inline typename This::Status |
| abs8(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval) |
| { |
| typedef typename elfcpp::Swap<8, big_endian>::Valtype Valtype; |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<8, big_endian>::readval(wv); |
| Reltype addend = utils::sign_extend<8>(val); |
| Reltype x = psymval->value(object, addend); |
| val = utils::bit_select(val, x, 0xffU); |
| elfcpp::Swap<8, big_endian>::writeval(wv, val); |
| return (utils::has_signed_unsigned_overflow<8>(x) |
| ? This::STATUS_OVERFLOW |
| : This::STATUS_OKAY); |
| } |
| |
| // R_ARM_THM_ABS5: S + A |
| static inline typename This::Status |
| thm_abs5(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval) |
| { |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<16, big_endian>::readval(wv); |
| Reltype addend = (val & 0x7e0U) >> 6; |
| Reltype x = psymval->value(object, addend); |
| val = utils::bit_select(val, x << 6, 0x7e0U); |
| elfcpp::Swap<16, big_endian>::writeval(wv, val); |
| return (utils::has_overflow<5>(x) |
| ? This::STATUS_OVERFLOW |
| : This::STATUS_OKAY); |
| } |
| |
| // R_ARM_ABS12: S + A |
| static inline typename This::Status |
| abs12(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
| Reltype addend = val & 0x0fffU; |
| Reltype x = psymval->value(object, addend); |
| val = utils::bit_select(val, x, 0x0fffU); |
| elfcpp::Swap<32, big_endian>::writeval(wv, val); |
| return (utils::has_overflow<12>(x) |
| ? This::STATUS_OVERFLOW |
| : This::STATUS_OKAY); |
| } |
| |
| // R_ARM_ABS16: S + A |
| static inline typename This::Status |
| abs16(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval) |
| { |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<16, big_endian>::readval(wv); |
| Reltype addend = utils::sign_extend<16>(val); |
| Reltype x = psymval->value(object, addend); |
| val = utils::bit_select(val, x, 0xffffU); |
| elfcpp::Swap<16, big_endian>::writeval(wv, val); |
| return (utils::has_signed_unsigned_overflow<16>(x) |
| ? This::STATUS_OVERFLOW |
| : This::STATUS_OKAY); |
| } |
| |
| // R_ARM_ABS32: (S + A) | T |
| static inline typename This::Status |
| abs32(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address thumb_bit) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv); |
| Valtype x = psymval->value(object, addend) | thumb_bit; |
| elfcpp::Swap<32, big_endian>::writeval(wv, x); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_REL32: (S + A) | T - P |
| static inline typename This::Status |
| rel32(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype addend = elfcpp::Swap<32, big_endian>::readval(wv); |
| Valtype x = (psymval->value(object, addend) | thumb_bit) - address; |
| elfcpp::Swap<32, big_endian>::writeval(wv, x); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_THM_CALL: (S + A) | T - P |
| static inline typename This::Status |
| thm_call(const Relocate_info<32, big_endian>* relinfo, unsigned char *view, |
| const Sized_symbol<32>* gsym, const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, const Symbol_value<32>* psymval, |
| Arm_address address, Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| return thumb_branch_common(elfcpp::R_ARM_THM_CALL, relinfo, view, gsym, |
| object, r_sym, psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| } |
| |
| // R_ARM_THM_JUMP24: (S + A) | T - P |
| static inline typename This::Status |
| thm_jump24(const Relocate_info<32, big_endian>* relinfo, unsigned char *view, |
| const Sized_symbol<32>* gsym, const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, const Symbol_value<32>* psymval, |
| Arm_address address, Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| return thumb_branch_common(elfcpp::R_ARM_THM_JUMP24, relinfo, view, gsym, |
| object, r_sym, psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| } |
| |
| // R_ARM_THM_XPC22: (S + A) | T - P |
| static inline typename This::Status |
| thm_xpc22(const Relocate_info<32, big_endian>* relinfo, unsigned char *view, |
| const Sized_symbol<32>* gsym, const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, const Symbol_value<32>* psymval, |
| Arm_address address, Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| return thumb_branch_common(elfcpp::R_ARM_THM_XPC22, relinfo, view, gsym, |
| object, r_sym, psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| } |
| |
| // R_ARM_BASE_PREL: B(S) + A - P |
| static inline typename This::Status |
| base_prel(unsigned char* view, |
| Arm_address origin, |
| Arm_address address) |
| { |
| Base::rel32(view, origin - address); |
| return STATUS_OKAY; |
| } |
| |
| // R_ARM_BASE_ABS: B(S) + A |
| static inline typename This::Status |
| base_abs(unsigned char* view, |
| Arm_address origin) |
| { |
| Base::rel32(view, origin); |
| return STATUS_OKAY; |
| } |
| |
| // R_ARM_GOT_BREL: GOT(S) + A - GOT_ORG |
| static inline typename This::Status |
| got_brel(unsigned char* view, |
| typename elfcpp::Swap<32, big_endian>::Valtype got_offset) |
| { |
| Base::rel32(view, got_offset); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_GOT_PREL: GOT(S) + A - P |
| static inline typename This::Status |
| got_prel(unsigned char *view, |
| Arm_address got_entry, |
| Arm_address address) |
| { |
| Base::rel32(view, got_entry - address); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_PLT32: (S + A) | T - P |
| static inline typename This::Status |
| plt32(const Relocate_info<32, big_endian>* relinfo, |
| unsigned char *view, |
| const Sized_symbol<32>* gsym, |
| const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| return arm_branch_common(elfcpp::R_ARM_PLT32, relinfo, view, gsym, |
| object, r_sym, psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| } |
| |
| // R_ARM_XPC25: (S + A) | T - P |
| static inline typename This::Status |
| xpc25(const Relocate_info<32, big_endian>* relinfo, |
| unsigned char *view, |
| const Sized_symbol<32>* gsym, |
| const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| return arm_branch_common(elfcpp::R_ARM_XPC25, relinfo, view, gsym, |
| object, r_sym, psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| } |
| |
| // R_ARM_CALL: (S + A) | T - P |
| static inline typename This::Status |
| call(const Relocate_info<32, big_endian>* relinfo, |
| unsigned char *view, |
| const Sized_symbol<32>* gsym, |
| const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| return arm_branch_common(elfcpp::R_ARM_CALL, relinfo, view, gsym, |
| object, r_sym, psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| } |
| |
| // R_ARM_JUMP24: (S + A) | T - P |
| static inline typename This::Status |
| jump24(const Relocate_info<32, big_endian>* relinfo, |
| unsigned char *view, |
| const Sized_symbol<32>* gsym, |
| const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| return arm_branch_common(elfcpp::R_ARM_JUMP24, relinfo, view, gsym, |
| object, r_sym, psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| } |
| |
| // R_ARM_PREL: (S + A) | T - P |
| static inline typename This::Status |
| prel31(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
| Valtype addend = utils::sign_extend<31>(val); |
| Valtype x = (psymval->value(object, addend) | thumb_bit) - address; |
| val = utils::bit_select(val, x, 0x7fffffffU); |
| elfcpp::Swap<32, big_endian>::writeval(wv, val); |
| return (utils::has_overflow<31>(x) ? |
| This::STATUS_OVERFLOW : This::STATUS_OKAY); |
| } |
| |
| // R_ARM_MOVW_ABS_NC: (S + A) | T |
| static inline typename This::Status |
| movw_abs_nc(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address thumb_bit) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
| Valtype addend = This::extract_arm_movw_movt_addend(val); |
| Valtype x = psymval->value(object, addend) | thumb_bit; |
| val = This::insert_val_arm_movw_movt(val, x); |
| elfcpp::Swap<32, big_endian>::writeval(wv, val); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_MOVT_ABS: S + A |
| static inline typename This::Status |
| movt_abs(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
| Valtype addend = This::extract_arm_movw_movt_addend(val); |
| Valtype x = psymval->value(object, addend) >> 16; |
| val = This::insert_val_arm_movw_movt(val, x); |
| elfcpp::Swap<32, big_endian>::writeval(wv, val); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_THM_MOVW_ABS_NC: S + A | T |
| static inline typename This::Status |
| thm_movw_abs_nc(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address thumb_bit) |
| { |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Reltype val = ((elfcpp::Swap<16, big_endian>::readval(wv) << 16) |
| | elfcpp::Swap<16, big_endian>::readval(wv + 1)); |
| Reltype addend = extract_thumb_movw_movt_addend(val); |
| Reltype x = psymval->value(object, addend) | thumb_bit; |
| val = This::insert_val_thumb_movw_movt(val, x); |
| elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); |
| elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_THM_MOVT_ABS: S + A |
| static inline typename This::Status |
| thm_movt_abs(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval) |
| { |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Reltype val = ((elfcpp::Swap<16, big_endian>::readval(wv) << 16) |
| | elfcpp::Swap<16, big_endian>::readval(wv + 1)); |
| Reltype addend = This::extract_thumb_movw_movt_addend(val); |
| Reltype x = psymval->value(object, addend) >> 16; |
| val = This::insert_val_thumb_movw_movt(val, x); |
| elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); |
| elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_MOVW_PREL_NC: (S + A) | T - P |
| static inline typename This::Status |
| movw_prel_nc(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
| Valtype addend = This::extract_arm_movw_movt_addend(val); |
| Valtype x = (psymval->value(object, addend) | thumb_bit) - address; |
| val = This::insert_val_arm_movw_movt(val, x); |
| elfcpp::Swap<32, big_endian>::writeval(wv, val); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_MOVT_PREL: S + A - P |
| static inline typename This::Status |
| movt_prel(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address address) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
| Valtype addend = This::extract_arm_movw_movt_addend(val); |
| Valtype x = (psymval->value(object, addend) - address) >> 16; |
| val = This::insert_val_arm_movw_movt(val, x); |
| elfcpp::Swap<32, big_endian>::writeval(wv, val); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_THM_MOVW_PREL_NC: (S + A) | T - P |
| static inline typename This::Status |
| thm_movw_prel_nc(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit) |
| { |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16) |
| | elfcpp::Swap<16, big_endian>::readval(wv + 1); |
| Reltype addend = This::extract_thumb_movw_movt_addend(val); |
| Reltype x = (psymval->value(object, addend) | thumb_bit) - address; |
| val = This::insert_val_thumb_movw_movt(val, x); |
| elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); |
| elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); |
| return This::STATUS_OKAY; |
| } |
| |
| // R_ARM_THM_MOVT_PREL: S + A - P |
| static inline typename This::Status |
| thm_movt_prel(unsigned char *view, |
| const Sized_relobj<32, big_endian>* object, |
| const Symbol_value<32>* psymval, |
| Arm_address address) |
| { |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Reltype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Reltype val = (elfcpp::Swap<16, big_endian>::readval(wv) << 16) |
| | elfcpp::Swap<16, big_endian>::readval(wv + 1); |
| Reltype addend = This::extract_thumb_movw_movt_addend(val); |
| Reltype x = (psymval->value(object, addend) - address) >> 16; |
| val = This::insert_val_thumb_movw_movt(val, x); |
| elfcpp::Swap<16, big_endian>::writeval(wv, val >> 16); |
| elfcpp::Swap<16, big_endian>::writeval(wv + 1, val & 0xffff); |
| return This::STATUS_OKAY; |
| } |
| }; |
| |
| // Relocate ARM long branches. This handles relocation types |
| // R_ARM_CALL, R_ARM_JUMP24, R_ARM_PLT32 and R_ARM_XPC25. |
| // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly |
| // undefined and we do not use PLT in this relocation. In such a case, |
| // the branch is converted into an NOP. |
| |
| template<bool big_endian> |
| typename Arm_relocate_functions<big_endian>::Status |
| Arm_relocate_functions<big_endian>::arm_branch_common( |
| unsigned int r_type, |
| const Relocate_info<32, big_endian>* relinfo, |
| unsigned char *view, |
| const Sized_symbol<32>* gsym, |
| const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
| |
| bool insn_is_b = (((val >> 28) & 0xf) <= 0xe) |
| && ((val & 0x0f000000UL) == 0x0a000000UL); |
| bool insn_is_uncond_bl = (val & 0xff000000UL) == 0xeb000000UL; |
| bool insn_is_cond_bl = (((val >> 28) & 0xf) < 0xe) |
| && ((val & 0x0f000000UL) == 0x0b000000UL); |
| bool insn_is_blx = (val & 0xfe000000UL) == 0xfa000000UL; |
| bool insn_is_any_branch = (val & 0x0e000000UL) == 0x0a000000UL; |
| |
| // Check that the instruction is valid. |
| if (r_type == elfcpp::R_ARM_CALL) |
| { |
| if (!insn_is_uncond_bl && !insn_is_blx) |
| return This::STATUS_BAD_RELOC; |
| } |
| else if (r_type == elfcpp::R_ARM_JUMP24) |
| { |
| if (!insn_is_b && !insn_is_cond_bl) |
| return This::STATUS_BAD_RELOC; |
| } |
| else if (r_type == elfcpp::R_ARM_PLT32) |
| { |
| if (!insn_is_any_branch) |
| return This::STATUS_BAD_RELOC; |
| } |
| else if (r_type == elfcpp::R_ARM_XPC25) |
| { |
| // FIXME: AAELF document IH0044C does not say much about it other |
| // than it being obsolete. |
| if (!insn_is_any_branch) |
| return This::STATUS_BAD_RELOC; |
| } |
| else |
| gold_unreachable(); |
| |
| // A branch to an undefined weak symbol is turned into a jump to |
| // the next instruction unless a PLT entry will be created. |
| // Do the same for local undefined symbols. |
| // The jump to the next instruction is optimized as a NOP depending |
| // on the architecture. |
| const Target_arm<big_endian>* arm_target = |
| Target_arm<big_endian>::default_target(); |
| if (is_weakly_undefined_without_plt) |
| { |
| Valtype cond = val & 0xf0000000U; |
| if (arm_target->may_use_arm_nop()) |
| val = cond | 0x0320f000; |
| else |
| val = cond | 0x01a00000; // Using pre-UAL nop: mov r0, r0. |
| elfcpp::Swap<32, big_endian>::writeval(wv, val); |
| return This::STATUS_OKAY; |
| } |
| |
| Valtype addend = utils::sign_extend<26>(val << 2); |
| Valtype branch_target = psymval->value(object, addend); |
| int32_t branch_offset = branch_target - address; |
| |
| // We need a stub if the branch offset is too large or if we need |
| // to switch mode. |
| bool may_use_blx = arm_target->may_use_blx(); |
| Reloc_stub* stub = NULL; |
| if ((branch_offset > ARM_MAX_FWD_BRANCH_OFFSET) |
| || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET) |
| || ((thumb_bit != 0) && !(may_use_blx && r_type == elfcpp::R_ARM_CALL))) |
| { |
| Stub_type stub_type = |
| Reloc_stub::stub_type_for_reloc(r_type, address, branch_target, |
| (thumb_bit != 0)); |
| if (stub_type != arm_stub_none) |
| { |
| Stub_table<big_endian>* stub_table = |
| object->stub_table(relinfo->data_shndx); |
| gold_assert(stub_table != NULL); |
| |
| Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend); |
| stub = stub_table->find_reloc_stub(stub_key); |
| gold_assert(stub != NULL); |
| thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0; |
| branch_target = stub_table->address() + stub->offset() + addend; |
| branch_offset = branch_target - address; |
| gold_assert((branch_offset <= ARM_MAX_FWD_BRANCH_OFFSET) |
| && (branch_offset >= ARM_MAX_BWD_BRANCH_OFFSET)); |
| } |
| } |
| |
| // At this point, if we still need to switch mode, the instruction |
| // must either be a BLX or a BL that can be converted to a BLX. |
| if (thumb_bit != 0) |
| { |
| // Turn BL to BLX. |
| gold_assert(may_use_blx && r_type == elfcpp::R_ARM_CALL); |
| val = (val & 0xffffff) | 0xfa000000 | ((branch_offset & 2) << 23); |
| } |
| |
| val = utils::bit_select(val, (branch_offset >> 2), 0xffffffUL); |
| elfcpp::Swap<32, big_endian>::writeval(wv, val); |
| return (utils::has_overflow<26>(branch_offset) |
| ? This::STATUS_OVERFLOW : This::STATUS_OKAY); |
| } |
| |
| // Relocate THUMB long branches. This handles relocation types |
| // R_ARM_THM_CALL, R_ARM_THM_JUMP24 and R_ARM_THM_XPC22. |
| // If IS_WEAK_UNDEFINED_WITH_PLT is true. The target symbol is weakly |
| // undefined and we do not use PLT in this relocation. In such a case, |
| // the branch is converted into an NOP. |
| |
| template<bool big_endian> |
| typename Arm_relocate_functions<big_endian>::Status |
| Arm_relocate_functions<big_endian>::thumb_branch_common( |
| unsigned int r_type, |
| const Relocate_info<32, big_endian>* relinfo, |
| unsigned char *view, |
| const Sized_symbol<32>* gsym, |
| const Arm_relobj<big_endian>* object, |
| unsigned int r_sym, |
| const Symbol_value<32>* psymval, |
| Arm_address address, |
| Arm_address thumb_bit, |
| bool is_weakly_undefined_without_plt) |
| { |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| Valtype* wv = reinterpret_cast<Valtype*>(view); |
| uint32_t upper_insn = elfcpp::Swap<16, big_endian>::readval(wv); |
| uint32_t lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1); |
| |
| // FIXME: These tests are too loose and do not take THUMB/THUMB-2 difference |
| // into account. |
| bool is_bl_insn = (lower_insn & 0x1000U) == 0x1000U; |
| bool is_blx_insn = (lower_insn & 0x1000U) == 0x0000U; |
| |
| // Check that the instruction is valid. |
| if (r_type == elfcpp::R_ARM_THM_CALL) |
| { |
| if (!is_bl_insn && !is_blx_insn) |
| return This::STATUS_BAD_RELOC; |
| } |
| else if (r_type == elfcpp::R_ARM_THM_JUMP24) |
| { |
| // This cannot be a BLX. |
| if (!is_bl_insn) |
| return This::STATUS_BAD_RELOC; |
| } |
| else if (r_type == elfcpp::R_ARM_THM_XPC22) |
| { |
| // Check for Thumb to Thumb call. |
| if (!is_blx_insn) |
| return This::STATUS_BAD_RELOC; |
| if (thumb_bit != 0) |
| { |
| gold_warning(_("%s: Thumb BLX instruction targets " |
| "thumb function '%s'."), |
| object->name().c_str(), |
| (gsym ? gsym->name() : "(local)")); |
| // Convert BLX to BL. |
| lower_insn |= 0x1000U; |
| } |
| } |
| else |
| gold_unreachable(); |
| |
| // A branch to an undefined weak symbol is turned into a jump to |
| // the next instruction unless a PLT entry will be created. |
| // The jump to the next instruction is optimized as a NOP.W for |
| // Thumb-2 enabled architectures. |
| const Target_arm<big_endian>* arm_target = |
| Target_arm<big_endian>::default_target(); |
| if (is_weakly_undefined_without_plt) |
| { |
| if (arm_target->may_use_thumb2_nop()) |
| { |
| elfcpp::Swap<16, big_endian>::writeval(wv, 0xf3af); |
| elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0x8000); |
| } |
| else |
| { |
| elfcpp::Swap<16, big_endian>::writeval(wv, 0xe000); |
| elfcpp::Swap<16, big_endian>::writeval(wv + 1, 0xbf00); |
| } |
| return This::STATUS_OKAY; |
| } |
| |
| // Fetch the addend. We use the Thumb-2 encoding (backwards compatible |
| // with Thumb-1) involving the J1 and J2 bits. |
| uint32_t s = (upper_insn & (1 << 10)) >> 10; |
| uint32_t upper = upper_insn & 0x3ff; |
| uint32_t lower = lower_insn & 0x7ff; |
| uint32_t j1 = (lower_insn & (1 << 13)) >> 13; |
| uint32_t j2 = (lower_insn & (1 << 11)) >> 11; |
| uint32_t i1 = j1 ^ s ? 0 : 1; |
| uint32_t i2 = j2 ^ s ? 0 : 1; |
| |
| int32_t addend = (i1 << 23) | (i2 << 22) | (upper << 12) | (lower << 1); |
| // Sign extend. |
| addend = (addend | ((s ? 0 : 1) << 24)) - (1 << 24); |
| |
| Arm_address branch_target = psymval->value(object, addend); |
| int32_t branch_offset = branch_target - address; |
| |
| // We need a stub if the branch offset is too large or if we need |
| // to switch mode. |
| bool may_use_blx = arm_target->may_use_blx(); |
| bool thumb2 = arm_target->using_thumb2(); |
| if ((!thumb2 |
| && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET |
| || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET))) |
| || (thumb2 |
| && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET |
| || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET))) |
| || ((thumb_bit == 0) |
| && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx) |
| || r_type == elfcpp::R_ARM_THM_JUMP24))) |
| { |
| Stub_type stub_type = |
| Reloc_stub::stub_type_for_reloc(r_type, address, branch_target, |
| (thumb_bit != 0)); |
| if (stub_type != arm_stub_none) |
| { |
| Stub_table<big_endian>* stub_table = |
| object->stub_table(relinfo->data_shndx); |
| gold_assert(stub_table != NULL); |
| |
| Reloc_stub::Key stub_key(stub_type, gsym, object, r_sym, addend); |
| Reloc_stub* stub = stub_table->find_reloc_stub(stub_key); |
| gold_assert(stub != NULL); |
| thumb_bit = stub->stub_template()->entry_in_thumb_mode() ? 1 : 0; |
| branch_target = stub_table->address() + stub->offset() + addend; |
| branch_offset = branch_target - address; |
| } |
| } |
| |
| // At this point, if we still need to switch mode, the instruction |
| // must either be a BLX or a BL that can be converted to a BLX. |
| if (thumb_bit == 0) |
| { |
| gold_assert(may_use_blx |
| && (r_type == elfcpp::R_ARM_THM_CALL |
| || r_type == elfcpp::R_ARM_THM_XPC22)); |
| // Make sure this is a BLX. |
| lower_insn &= ~0x1000U; |
| } |
| else |
| { |
| // Make sure this is a BL. |
| lower_insn |= 0x1000U; |
| } |
| |
| uint32_t reloc_sign = (branch_offset < 0) ? 1 : 0; |
| uint32_t relocation = static_cast<uint32_t>(branch_offset); |
| |
| if ((lower_insn & 0x5000U) == 0x4000U) |
| // For a BLX instruction, make sure that the relocation is rounded up |
| // to a word boundary. This follows the semantics of the instruction |
| // which specifies that bit 1 of the target address will come from bit |
| // 1 of the base address. |
| relocation = (relocation + 2U) & ~3U; |
| |
| // Put BRANCH_OFFSET back into the insn. Assumes two's complement. |
| // We use the Thumb-2 encoding, which is safe even if dealing with |
| // a Thumb-1 instruction by virtue of our overflow check above. */ |
| upper_insn = (upper_insn & ~0x7ffU) |
| | ((relocation >> 12) & 0x3ffU) |
| | (reloc_sign << 10); |
| lower_insn = (lower_insn & ~0x2fffU) |
| | (((!((relocation >> 23) & 1U)) ^ reloc_sign) << 13) |
| | (((!((relocation >> 22) & 1U)) ^ reloc_sign) << 11) |
| | ((relocation >> 1) & 0x7ffU); |
| |
| elfcpp::Swap<16, big_endian>::writeval(wv, upper_insn); |
| elfcpp::Swap<16, big_endian>::writeval(wv + 1, lower_insn); |
| |
| return ((thumb2 |
| ? utils::has_overflow<25>(relocation) |
| : utils::has_overflow<23>(relocation)) |
| ? This::STATUS_OVERFLOW |
| : This::STATUS_OKAY); |
| } |
| |
| // Get the GOT section, creating it if necessary. |
| |
| template<bool big_endian> |
| Output_data_got<32, big_endian>* |
| Target_arm<big_endian>::got_section(Symbol_table* symtab, Layout* layout) |
| { |
| if (this->got_ == NULL) |
| { |
| gold_assert(symtab != NULL && layout != NULL); |
| |
| this->got_ = new Output_data_got<32, big_endian>(); |
| |
| Output_section* os; |
| os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| (elfcpp::SHF_ALLOC |
| | elfcpp::SHF_WRITE), |
| this->got_, false); |
| os->set_is_relro(); |
| |
| // The old GNU linker creates a .got.plt section. We just |
| // create another set of data in the .got section. Note that we |
| // always create a PLT if we create a GOT, although the PLT |
| // might be empty. |
| this->got_plt_ = new Output_data_space(4, "** GOT PLT"); |
| os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| (elfcpp::SHF_ALLOC |
| | elfcpp::SHF_WRITE), |
| this->got_plt_, false); |
| os->set_is_relro(); |
| |
| // The first three entries are reserved. |
| this->got_plt_->set_current_data_size(3 * 4); |
| |
| // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
| symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, |
| this->got_plt_, |
| 0, 0, elfcpp::STT_OBJECT, |
| elfcpp::STB_LOCAL, |
| elfcpp::STV_HIDDEN, 0, |
| false, false); |
| } |
| return this->got_; |
| } |
| |
| // Get the dynamic reloc section, creating it if necessary. |
| |
| template<bool big_endian> |
| typename Target_arm<big_endian>::Reloc_section* |
| Target_arm<big_endian>::rel_dyn_section(Layout* layout) |
| { |
| if (this->rel_dyn_ == NULL) |
| { |
| gold_assert(layout != NULL); |
| this->rel_dyn_ = new Reloc_section(parameters->options().combreloc()); |
| layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, |
| elfcpp::SHF_ALLOC, this->rel_dyn_, true); |
| } |
| return this->rel_dyn_; |
| } |
| |
| // Insn_template methods. |
| |
| // Return byte size of an instruction template. |
| |
| size_t |
| Insn_template::size() const |
| { |
| switch (this->type()) |
| { |
| case THUMB16_TYPE: |
| return 2; |
| case ARM_TYPE: |
| case THUMB32_TYPE: |
| case DATA_TYPE: |
| return 4; |
| default: |
| gold_unreachable(); |
| } |
| } |
| |
| // Return alignment of an instruction template. |
| |
| unsigned |
| Insn_template::alignment() const |
| { |
| switch (this->type()) |
| { |
| case THUMB16_TYPE: |
| case THUMB32_TYPE: |
| return 2; |
| case ARM_TYPE: |
| case DATA_TYPE: |
| return 4; |
| default: |
| gold_unreachable(); |
| } |
| } |
| |
| // Stub_template methods. |
| |
| Stub_template::Stub_template( |
| Stub_type type, const Insn_template* insns, |
| size_t insn_count) |
| : type_(type), insns_(insns), insn_count_(insn_count), alignment_(1), |
| entry_in_thumb_mode_(false), relocs_() |
| { |
| off_t offset = 0; |
| |
| // Compute byte size and alignment of stub template. |
| for (size_t i = 0; i < insn_count; i++) |
| { |
| unsigned insn_alignment = insns[i].alignment(); |
| size_t insn_size = insns[i].size(); |
| gold_assert((offset & (insn_alignment - 1)) == 0); |
| this->alignment_ = std::max(this->alignment_, insn_alignment); |
| switch (insns[i].type()) |
| { |
| case Insn_template::THUMB16_TYPE: |
| if (i == 0) |
| this->entry_in_thumb_mode_ = true; |
| break; |
| |
| case Insn_template::THUMB32_TYPE: |
| if (insns[i].r_type() != elfcpp::R_ARM_NONE) |
| this->relocs_.push_back(Reloc(i, offset)); |
| if (i == 0) |
| this->entry_in_thumb_mode_ = true; |
| break; |
| |
| case Insn_template::ARM_TYPE: |
| // Handle cases where the target is encoded within the |
| // instruction. |
| if (insns[i].r_type() == elfcpp::R_ARM_JUMP24) |
| this->relocs_.push_back(Reloc(i, offset)); |
| break; |
| |
| case Insn_template::DATA_TYPE: |
| // Entry point cannot be data. |
| gold_assert(i != 0); |
| this->relocs_.push_back(Reloc(i, offset)); |
| break; |
| |
| default: |
| gold_unreachable(); |
| } |
| offset += insn_size; |
| } |
| this->size_ = offset; |
| } |
| |
| // Reloc_stub::Key methods. |
| |
| // Dump a Key as a string for debugging. |
| |
| std::string |
| Reloc_stub::Key::name() const |
| { |
| if (this->r_sym_ == invalid_index) |
| { |
| // Global symbol key name |
| // <stub-type>:<symbol name>:<addend>. |
| const std::string sym_name = this->u_.symbol->name(); |
| // We need to print two hex number and two colons. So just add 100 bytes |
| // to the symbol name size. |
| size_t len = sym_name.size() + 100; |
| char* buffer = new char[len]; |
| int c = snprintf(buffer, len, "%d:%s:%x", this->stub_type_, |
| sym_name.c_str(), this->addend_); |
| gold_assert(c > 0 && c < static_cast<int>(len)); |
| delete[] buffer; |
| return std::string(buffer); |
| } |
| else |
| { |
| // local symbol key name |
| // <stub-type>:<object>:<r_sym>:<addend>. |
| const size_t len = 200; |
| char buffer[len]; |
| int c = snprintf(buffer, len, "%d:%p:%u:%x", this->stub_type_, |
| this->u_.relobj, this->r_sym_, this->addend_); |
| gold_assert(c > 0 && c < static_cast<int>(len)); |
| return std::string(buffer); |
| } |
| } |
| |
| // Reloc_stub methods. |
| |
| // Determine the type of stub needed, if any, for a relocation of R_TYPE at |
| // LOCATION to DESTINATION. |
| // This code is based on the arm_type_of_stub function in |
| // bfd/elf32-arm.c. We have changed the interface a liitle to keep the Stub |
| // class simple. |
| |
| Stub_type |
| Reloc_stub::stub_type_for_reloc( |
| unsigned int r_type, |
| Arm_address location, |
| Arm_address destination, |
| bool target_is_thumb) |
| { |
| Stub_type stub_type = arm_stub_none; |
| |
| // This is a bit ugly but we want to avoid using a templated class for |
| // big and little endianities. |
| bool may_use_blx; |
| bool should_force_pic_veneer; |
| bool thumb2; |
| bool thumb_only; |
| if (parameters->target().is_big_endian()) |
| { |
| const Target_arm<true>* big_endian_target = |
| Target_arm<true>::default_target(); |
| may_use_blx = big_endian_target->may_use_blx(); |
| should_force_pic_veneer = big_endian_target->should_force_pic_veneer(); |
| thumb2 = big_endian_target->using_thumb2(); |
| thumb_only = big_endian_target->using_thumb_only(); |
| } |
| else |
| { |
| const Target_arm<false>* little_endian_target = |
| Target_arm<false>::default_target(); |
| may_use_blx = little_endian_target->may_use_blx(); |
| should_force_pic_veneer = little_endian_target->should_force_pic_veneer(); |
| thumb2 = little_endian_target->using_thumb2(); |
| thumb_only = little_endian_target->using_thumb_only(); |
| } |
| |
| int64_t branch_offset = (int64_t)destination - location; |
| |
| if (r_type == elfcpp::R_ARM_THM_CALL || r_type == elfcpp::R_ARM_THM_JUMP24) |
| { |
| // Handle cases where: |
| // - this call goes too far (different Thumb/Thumb2 max |
| // distance) |
| // - it's a Thumb->Arm call and blx is not available, or it's a |
| // Thumb->Arm branch (not bl). A stub is needed in this case. |
| if ((!thumb2 |
| && (branch_offset > THM_MAX_FWD_BRANCH_OFFSET |
| || (branch_offset < THM_MAX_BWD_BRANCH_OFFSET))) |
| || (thumb2 |
| && (branch_offset > THM2_MAX_FWD_BRANCH_OFFSET |
| || (branch_offset < THM2_MAX_BWD_BRANCH_OFFSET))) |
| || ((!target_is_thumb) |
| && (((r_type == elfcpp::R_ARM_THM_CALL) && !may_use_blx) |
| || (r_type == elfcpp::R_ARM_THM_JUMP24)))) |
| { |
| if (target_is_thumb) |
| { |
| // Thumb to thumb. |
| if (!thumb_only) |
| { |
| stub_type = (parameters->options().shared() |
| || should_force_pic_veneer) |
| // PIC stubs. |
| ? ((may_use_blx |
| && (r_type == elfcpp::R_ARM_THM_CALL)) |
| // V5T and above. Stub starts with ARM code, so |
| // we must be able to switch mode before |
| // reaching it, which is only possible for 'bl' |
| // (ie R_ARM_THM_CALL relocation). |
| ? arm_stub_long_branch_any_thumb_pic |
| // On V4T, use Thumb code only. |
| : arm_stub_long_branch_v4t_thumb_thumb_pic) |
| |
| // non-PIC stubs. |
| : ((may_use_blx |
| && (r_type == elfcpp::R_ARM_THM_CALL)) |
| ? arm_stub_long_branch_any_any // V5T and above. |
| : arm_stub_long_branch_v4t_thumb_thumb); // V4T. |
| } |
| else |
| { |
| stub_type = (parameters->options().shared() |
| || should_force_pic_veneer) |
| ? arm_stub_long_branch_thumb_only_pic // PIC stub. |
| : arm_stub_long_branch_thumb_only; // non-PIC stub. |
| } |
| } |
| else |
| { |
| // Thumb to arm. |
| |
| // FIXME: We should check that the input section is from an |
| // object that has interwork enabled. |
| |
| stub_type = (parameters->options().shared() |
| || should_force_pic_veneer) |
| // PIC stubs. |
| ? ((may_use_blx |
| && (r_type == elfcpp::R_ARM_THM_CALL)) |
| ? arm_stub_long_branch_any_arm_pic // V5T and above. |
| : arm_stub_long_branch_v4t_thumb_arm_pic) // V4T. |
| |
| // non-PIC stubs. |
| : ((may_use_blx |
| && (r_type == elfcpp::R_ARM_THM_CALL)) |
| ? arm_stub_long_branch_any_any // V5T and above. |
| : arm_stub_long_branch_v4t_thumb_arm); // V4T. |
| |
| // Handle v4t short branches. |
| if ((stub_type == arm_stub_long_branch_v4t_thumb_arm) |
| && (branch_offset <= THM_MAX_FWD_BRANCH_OFFSET) |
| && (branch_offset >= THM_MAX_BWD_BRANCH_OFFSET)) |
| stub_type = arm_stub_short_branch_v4t_thumb_arm; |
| } |
| } |
| } |
| else if (r_type == elfcpp::R_ARM_CALL |
| || r_type == elfcpp::R_ARM_JUMP24 |
| || r_type == elfcpp::R_ARM_PLT32) |
| { |
| if (target_is_thumb) |
| { |
| // Arm to thumb. |
| |
| // FIXME: We should check that the input section is from an |
| // object that has interwork enabled. |
| |
| // We have an extra 2-bytes reach because of |
| // the mode change (bit 24 (H) of BLX encoding). |
| if (branch_offset > (ARM_MAX_FWD_BRANCH_OFFSET + 2) |
| || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET) |
| || ((r_type == elfcpp::R_ARM_CALL) && !may_use_blx) |
| || (r_type == elfcpp::R_ARM_JUMP24) |
| || (r_type == elfcpp::R_ARM_PLT32)) |
| { |
| stub_type = (parameters->options().shared() |
| || should_force_pic_veneer) |
| // PIC stubs. |
| ? (may_use_blx |
| ? arm_stub_long_branch_any_thumb_pic// V5T and above. |
| : arm_stub_long_branch_v4t_arm_thumb_pic) // V4T stub. |
| |
| // non-PIC stubs. |
| : (may_use_blx |
| ? arm_stub_long_branch_any_any // V5T and above. |
| : arm_stub_long_branch_v4t_arm_thumb); // V4T. |
| } |
| } |
| else |
| { |
| // Arm to arm. |
| if (branch_offset > ARM_MAX_FWD_BRANCH_OFFSET |
| || (branch_offset < ARM_MAX_BWD_BRANCH_OFFSET)) |
| { |
| stub_type = (parameters->options().shared() |
| || should_force_pic_veneer) |
| ? arm_stub_long_branch_any_arm_pic // PIC stubs. |
| : arm_stub_long_branch_any_any; /// non-PIC. |
| } |
| } |
| } |
| |
| return stub_type; |
| } |
| |
| // Template to implement do_write for a specific target endianity. |
| |
| template<bool big_endian> |
| void inline |
| Reloc_stub::do_fixed_endian_write(unsigned char* view, |
| section_size_type view_size) |
| { |
| const Stub_template* stub_template = this->stub_template(); |
| const Insn_template* insns = stub_template->insns(); |
| |
| // FIXME: We do not handle BE8 encoding yet. |
| unsigned char* pov = view; |
| for (size_t i = 0; i < stub_template->insn_count(); i++) |
| { |
| switch (insns[i].type()) |
| { |
| case Insn_template::THUMB16_TYPE: |
| // Non-zero reloc addends are only used in Cortex-A8 stubs. |
| gold_assert(insns[i].reloc_addend() == 0); |
| elfcpp::Swap<16, big_endian>::writeval(pov, insns[i].data() & 0xffff); |
| break; |
| case Insn_template::THUMB32_TYPE: |
| { |
| uint32_t hi = (insns[i].data() >> 16) & 0xffff; |
| uint32_t lo = insns[i].data() & 0xffff; |
| elfcpp::Swap<16, big_endian>::writeval(pov, hi); |
| elfcpp::Swap<16, big_endian>::writeval(pov + 2, lo); |
| } |
| break; |
| case Insn_template::ARM_TYPE: |
| case Insn_template::DATA_TYPE: |
| elfcpp::Swap<32, big_endian>::writeval(pov, insns[i].data()); |
| break; |
| default: |
| gold_unreachable(); |
| } |
| pov += insns[i].size(); |
| } |
| gold_assert(static_cast<section_size_type>(pov - view) == view_size); |
| } |
| |
| // Write a reloc stub to VIEW with endianity specified by BIG_ENDIAN. |
| |
| void |
| Reloc_stub::do_write(unsigned char* view, section_size_type view_size, |
| bool big_endian) |
| { |
| if (big_endian) |
| this->do_fixed_endian_write<true>(view, view_size); |
| else |
| this->do_fixed_endian_write<false>(view, view_size); |
| } |
| |
| // Stub_factory methods. |
| |
| Stub_factory::Stub_factory() |
| { |
| // The instruction template sequences are declared as static |
| // objects and initialized first time the constructor runs. |
| |
| // Arm/Thumb -> Arm/Thumb long branch stub. On V5T and above, use blx |
| // to reach the stub if necessary. |
| static const Insn_template elf32_arm_stub_long_branch_any_any[] = |
| { |
| Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4] |
| Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
| // dcd R_ARM_ABS32(X) |
| }; |
| |
| // V4T Arm -> Thumb long branch stub. Used on V4T where blx is not |
| // available. |
| static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb[] = |
| { |
| Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0] |
| Insn_template::arm_insn(0xe12fff1c), // bx ip |
| Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
| // dcd R_ARM_ABS32(X) |
| }; |
| |
| // Thumb -> Thumb long branch stub. Used on M-profile architectures. |
| static const Insn_template elf32_arm_stub_long_branch_thumb_only[] = |
| { |
| Insn_template::thumb16_insn(0xb401), // push {r0} |
| Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8] |
| Insn_template::thumb16_insn(0x4684), // mov ip, r0 |
| Insn_template::thumb16_insn(0xbc01), // pop {r0} |
| Insn_template::thumb16_insn(0x4760), // bx ip |
| Insn_template::thumb16_insn(0xbf00), // nop |
| Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
| // dcd R_ARM_ABS32(X) |
| }; |
| |
| // V4T Thumb -> Thumb long branch stub. Using the stack is not |
| // allowed. |
| static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb[] = |
| { |
| Insn_template::thumb16_insn(0x4778), // bx pc |
| Insn_template::thumb16_insn(0x46c0), // nop |
| Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0] |
| Insn_template::arm_insn(0xe12fff1c), // bx ip |
| Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
| // dcd R_ARM_ABS32(X) |
| }; |
| |
| // V4T Thumb -> ARM long branch stub. Used on V4T where blx is not |
| // available. |
| static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm[] = |
| { |
| Insn_template::thumb16_insn(0x4778), // bx pc |
| Insn_template::thumb16_insn(0x46c0), // nop |
| Insn_template::arm_insn(0xe51ff004), // ldr pc, [pc, #-4] |
| Insn_template::data_word(0, elfcpp::R_ARM_ABS32, 0), |
| // dcd R_ARM_ABS32(X) |
| }; |
| |
| // V4T Thumb -> ARM short branch stub. Shorter variant of the above |
| // one, when the destination is close enough. |
| static const Insn_template elf32_arm_stub_short_branch_v4t_thumb_arm[] = |
| { |
| Insn_template::thumb16_insn(0x4778), // bx pc |
| Insn_template::thumb16_insn(0x46c0), // nop |
| Insn_template::arm_rel_insn(0xea000000, -8), // b (X-8) |
| }; |
| |
| // ARM/Thumb -> ARM long branch stub, PIC. On V5T and above, use |
| // blx to reach the stub if necessary. |
| static const Insn_template elf32_arm_stub_long_branch_any_arm_pic[] = |
| { |
| Insn_template::arm_insn(0xe59fc000), // ldr r12, [pc] |
| Insn_template::arm_insn(0xe08ff00c), // add pc, pc, ip |
| Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4), |
| // dcd R_ARM_REL32(X-4) |
| }; |
| |
| // ARM/Thumb -> Thumb long branch stub, PIC. On V5T and above, use |
| // blx to reach the stub if necessary. We can not add into pc; |
| // it is not guaranteed to mode switch (different in ARMv6 and |
| // ARMv7). |
| static const Insn_template elf32_arm_stub_long_branch_any_thumb_pic[] = |
| { |
| Insn_template::arm_insn(0xe59fc004), // ldr r12, [pc, #4] |
| Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip |
| Insn_template::arm_insn(0xe12fff1c), // bx ip |
| Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0), |
| // dcd R_ARM_REL32(X) |
| }; |
| |
| // V4T ARM -> ARM long branch stub, PIC. |
| static const Insn_template elf32_arm_stub_long_branch_v4t_arm_thumb_pic[] = |
| { |
| Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4] |
| Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip |
| Insn_template::arm_insn(0xe12fff1c), // bx ip |
| Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0), |
| // dcd R_ARM_REL32(X) |
| }; |
| |
| // V4T Thumb -> ARM long branch stub, PIC. |
| static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_arm_pic[] = |
| { |
| Insn_template::thumb16_insn(0x4778), // bx pc |
| Insn_template::thumb16_insn(0x46c0), // nop |
| Insn_template::arm_insn(0xe59fc000), // ldr ip, [pc, #0] |
| Insn_template::arm_insn(0xe08cf00f), // add pc, ip, pc |
| Insn_template::data_word(0, elfcpp::R_ARM_REL32, -4), |
| // dcd R_ARM_REL32(X) |
| }; |
| |
| // Thumb -> Thumb long branch stub, PIC. Used on M-profile |
| // architectures. |
| static const Insn_template elf32_arm_stub_long_branch_thumb_only_pic[] = |
| { |
| Insn_template::thumb16_insn(0xb401), // push {r0} |
| Insn_template::thumb16_insn(0x4802), // ldr r0, [pc, #8] |
| Insn_template::thumb16_insn(0x46fc), // mov ip, pc |
| Insn_template::thumb16_insn(0x4484), // add ip, r0 |
| Insn_template::thumb16_insn(0xbc01), // pop {r0} |
| Insn_template::thumb16_insn(0x4760), // bx ip |
| Insn_template::data_word(0, elfcpp::R_ARM_REL32, 4), |
| // dcd R_ARM_REL32(X) |
| }; |
| |
| // V4T Thumb -> Thumb long branch stub, PIC. Using the stack is not |
| // allowed. |
| static const Insn_template elf32_arm_stub_long_branch_v4t_thumb_thumb_pic[] = |
| { |
| Insn_template::thumb16_insn(0x4778), // bx pc |
| Insn_template::thumb16_insn(0x46c0), // nop |
| Insn_template::arm_insn(0xe59fc004), // ldr ip, [pc, #4] |
| Insn_template::arm_insn(0xe08fc00c), // add ip, pc, ip |
| Insn_template::arm_insn(0xe12fff1c), // bx ip |
| Insn_template::data_word(0, elfcpp::R_ARM_REL32, 0), |
| // dcd R_ARM_REL32(X) |
| }; |
| |
| // Cortex-A8 erratum-workaround stubs. |
| |
| // Stub used for conditional branches (which may be beyond +/-1MB away, |
| // so we can't use a conditional branch to reach this stub). |
| |
| // original code: |
| // |
| // b<cond> X |
| // after: |
| // |
| static const Insn_template elf32_arm_stub_a8_veneer_b_cond[] = |
| { |
| Insn_template::thumb16_bcond_insn(0xd001), // b<cond>.n true |
| Insn_template::thumb32_b_insn(0xf000b800, -4), // b.w after |
| Insn_template::thumb32_b_insn(0xf000b800, -4) // true: |
| // b.w X |
| }; |
| |
| // Stub used for b.w and bl.w instructions. |
| |
| static const Insn_template elf32_arm_stub_a8_veneer_b[] = |
| { |
| Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest |
| }; |
| |
| static const Insn_template elf32_arm_stub_a8_veneer_bl[] = |
| { |
| Insn_template::thumb32_b_insn(0xf000b800, -4) // b.w dest |
| }; |
| |
| // Stub used for Thumb-2 blx.w instructions. We modified the original blx.w |
| // instruction (which switches to ARM mode) to point to this stub. Jump to |
| // the real destination using an ARM-mode branch. |
| const Insn_template elf32_arm_stub_a8_veneer_blx[] = |
| { |
| Insn_template::arm_rel_insn(0xea000000, -8) // b dest |
| }; |
| |
| // Fill in the stub template look-up table. Stub templates are constructed |
| // per instance of Stub_factory for fast look-up without locking |
| // in a thread-enabled environment. |
| |
| this->stub_templates_[arm_stub_none] = |
| new Stub_template(arm_stub_none, NULL, 0); |
| |
| #define DEF_STUB(x) \ |
| do \ |
| { \ |
| size_t array_size \ |
| = sizeof(elf32_arm_stub_##x) / sizeof(elf32_arm_stub_##x[0]); \ |
| Stub_type type = arm_stub_##x; \ |
| this->stub_templates_[type] = \ |
| new Stub_template(type, elf32_arm_stub_##x, array_size); \ |
| } \ |
| while (0); |
| |
| DEF_STUBS |
| #undef DEF_STUB |
| } |
| |
| // Stub_table methods. |
| |
| // Add a STUB with using KEY. Caller is reponsible for avoid adding |
| // if already a STUB with the same key has been added. |
| |
| template<bool big_endian> |
| void |
| Stub_table<big_endian>::add_reloc_stub( |
| Reloc_stub* stub, |
| const Reloc_stub::Key& key) |
| { |
| const Stub_template* stub_template = stub->stub_template(); |
| gold_assert(stub_template->type() == key.stub_type()); |
| this->reloc_stubs_[key] = stub; |
| if (this->addralign_ < stub_template->alignment()) |
| this->addralign_ = stub_template->alignment(); |
| this->has_been_changed_ = true; |
| } |
| |
| template<bool big_endian> |
| void |
| Stub_table<big_endian>::relocate_stubs( |
| const Relocate_info<32, big_endian>* relinfo, |
| Target_arm<big_endian>* arm_target, |
| Output_section* output_section, |
| unsigned char* view, |
| Arm_address address, |
| section_size_type view_size) |
| { |
| // If we are passed a view bigger than the stub table's. we need to |
| // adjust the view. |
| gold_assert(address == this->address() |
| && (view_size |
| == static_cast<section_size_type>(this->data_size()))); |
| |
| for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin(); |
| p != this->reloc_stubs_.end(); |
| ++p) |
| { |
| Reloc_stub* stub = p->second; |
| const Stub_template* stub_template = stub->stub_template(); |
| if (stub_template->reloc_count() != 0) |
| { |
| // Adjust view to cover the stub only. |
| section_size_type offset = stub->offset(); |
| section_size_type stub_size = stub_template->size(); |
| gold_assert(offset + stub_size <= view_size); |
| |
| arm_target->relocate_stub(stub, relinfo, output_section, |
| view + offset, address + offset, |
| stub_size); |
| } |
| } |
| } |
| |
| // Reset address and file offset. |
| |
| template<bool big_endian> |
| void |
| Stub_table<big_endian>::do_reset_address_and_file_offset() |
| { |
| off_t off = 0; |
| uint64_t max_addralign = 1; |
| for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin(); |
| p != this->reloc_stubs_.end(); |
| ++p) |
| { |
| Reloc_stub* stub = p->second; |
| const Stub_template* stub_template = stub->stub_template(); |
| uint64_t stub_addralign = stub_template->alignment(); |
| max_addralign = std::max(max_addralign, stub_addralign); |
| off = align_address(off, stub_addralign); |
| stub->set_offset(off); |
| stub->reset_destination_address(); |
| off += stub_template->size(); |
| } |
| |
| this->addralign_ = max_addralign; |
| this->set_current_data_size_for_child(off); |
| } |
| |
| // Write out the stubs to file. |
| |
| template<bool big_endian> |
| void |
| Stub_table<big_endian>::do_write(Output_file* of) |
| { |
| off_t offset = this->offset(); |
| const section_size_type oview_size = |
| convert_to_section_size_type(this->data_size()); |
| unsigned char* const oview = of->get_output_view(offset, oview_size); |
| |
| for (typename Reloc_stub_map::const_iterator p = this->reloc_stubs_.begin(); |
| p != this->reloc_stubs_.end(); |
| ++p) |
| { |
| Reloc_stub* stub = p->second; |
| Arm_address address = this->address() + stub->offset(); |
| gold_assert(address |
| == align_address(address, |
| stub->stub_template()->alignment())); |
| stub->write(oview + stub->offset(), stub->stub_template()->size(), |
| big_endian); |
| } |
| of->write_output_view(this->offset(), oview_size, oview); |
| } |
| |
| // Arm_input_section methods. |
| |
| // Initialize an Arm_input_section. |
| |
| template<bool big_endian> |
| void |
| Arm_input_section<big_endian>::init() |
| { |
| Relobj* relobj = this->relobj(); |
| unsigned int shndx = this->shndx(); |
| |
| // Cache these to speed up size and alignment queries. It is too slow |
| // to call section_addraglin and section_size every time. |
| this->original_addralign_ = relobj->section_addralign(shndx); |
| this->original_size_ = relobj->section_size(shndx); |
| |
| // We want to make this look like the original input section after |
| // output sections are finalized. |
| Output_section* os = relobj->output_section(shndx); |
| off_t offset = relobj->output_section_offset(shndx); |
| gold_assert(os != NULL && !relobj->is_output_section_offset_invalid(shndx)); |
| this->set_address(os->address() + offset); |
| this->set_file_offset(os->offset() + offset); |
| |
| this->set_current_data_size(this->original_size_); |
| this->finalize_data_size(); |
| } |
| |
| template<bool big_endian> |
| void |
| Arm_input_section<big_endian>::do_write(Output_file* of) |
| { |
| // We have to write out the original section content. |
| section_size_type section_size; |
| const unsigned char* section_contents = |
| this->relobj()->section_contents(this->shndx(), §ion_size, false); |
| of->write(this->offset(), section_contents, section_size); |
| |
| // If this owns a stub table and it is not empty, write it. |
| if (this->is_stub_table_owner() && !this->stub_table_->empty()) |
| this->stub_table_->write(of); |
| } |
| |
| // Finalize data size. |
| |
| template<bool big_endian> |
| void |
| Arm_input_section<big_endian>::set_final_data_size() |
| { |
| // If this owns a stub table, finalize its data size as well. |
| if (this->is_stub_table_owner()) |
| { |
| uint64_t address = this->address(); |
| |
| // The stub table comes after the original section contents. |
| address += this->original_size_; |
| address = align_address(address, this->stub_table_->addralign()); |
| off_t offset = this->offset() + (address - this->address()); |
| this->stub_table_->set_address_and_file_offset(address, offset); |
| address += this->stub_table_->data_size(); |
| gold_assert(address == this->address() + this->current_data_size()); |
| } |
| |
| this->set_data_size(this->current_data_size()); |
| } |
| |
| // Reset address and file offset. |
| |
| template<bool big_endian> |
| void |
| Arm_input_section<big_endian>::do_reset_address_and_file_offset() |
| { |
| // Size of the original input section contents. |
| off_t off = convert_types<off_t, uint64_t>(this->original_size_); |
| |
| // If this is a stub table owner, account for the stub table size. |
| if (this->is_stub_table_owner()) |
| { |
| Stub_table<big_endian>* stub_table = this->stub_table_; |
| |
| // Reset the stub table's address and file offset. The |
| // current data size for child will be updated after that. |
| stub_table_->reset_address_and_file_offset(); |
| off = align_address(off, stub_table_->addralign()); |
| off += stub_table->current_data_size(); |
| } |
| |
| this->set_current_data_size(off); |
| } |
| |
| // Arm_output_section methods. |
| |
| // Create a stub group for input sections from BEGIN to END. OWNER |
| // points to the input section to be the owner a new stub table. |
| |
| template<bool big_endian> |
| void |
| Arm_output_section<big_endian>::create_stub_group( |
| Input_section_list::const_iterator begin, |
| Input_section_list::const_iterator end, |
| Input_section_list::const_iterator owner, |
| Target_arm<big_endian>* target, |
| std::vector<Output_relaxed_input_section*>* new_relaxed_sections) |
| { |
| // Currently we convert ordinary input sections into relaxed sections only |
| // at this point but we may want to support creating relaxed input section |
| // very early. So we check here to see if owner is already a relaxed |
| // section. |
| |
| Arm_input_section<big_endian>* arm_input_section; |
| if (owner->is_relaxed_input_section()) |
| { |
| arm_input_section = |
| Arm_input_section<big_endian>::as_arm_input_section( |
| owner->relaxed_input_section()); |
| } |
| else |
| { |
| gold_assert(owner->is_input_section()); |
| // Create a new relaxed input section. |
| arm_input_section = |
| target->new_arm_input_section(owner->relobj(), owner->shndx()); |
| new_relaxed_sections->push_back(arm_input_section); |
| } |
| |
| // Create a stub table. |
| Stub_table<big_endian>* stub_table = |
| target->new_stub_table(arm_input_section); |
| |
| arm_input_section->set_stub_table(stub_table); |
| |
| Input_section_list::const_iterator p = begin; |
| Input_section_list::const_iterator prev_p; |
| |
| // Look for input sections or relaxed input sections in [begin ... end]. |
| do |
| { |
| if (p->is_input_section() || p->is_relaxed_input_section()) |
| { |
| // The stub table information for input sections live |
| // in their objects. |
| Arm_relobj<big_endian>* arm_relobj = |
| Arm_relobj<big_endian>::as_arm_relobj(p->relobj()); |
| arm_relobj->set_stub_table(p->shndx(), stub_table); |
| } |
| prev_p = p++; |
| } |
| while (prev_p != end); |
| } |
| |
| // Group input sections for stub generation. GROUP_SIZE is roughly the limit |
| // of stub groups. We grow a stub group by adding input section until the |
| // size is just below GROUP_SIZE. The last input section will be converted |
| // into a stub table. If STUB_ALWAYS_AFTER_BRANCH is false, we also add |
| // input section after the stub table, effectively double the group size. |
| // |
| // This is similar to the group_sections() function in elf32-arm.c but is |
| // implemented differently. |
| |
| template<bool big_endian> |
| void |
| Arm_output_section<big_endian>::group_sections( |
| section_size_type group_size, |
| bool stubs_always_after_branch, |
| Target_arm<big_endian>* target) |
| { |
| // We only care about sections containing code. |
| if ((this->flags() & elfcpp::SHF_EXECINSTR) == 0) |
| return; |
| |
| // States for grouping. |
| typedef enum |
| { |
| // No group is being built. |
| NO_GROUP, |
| // A group is being built but the stub table is not found yet. |
| // We keep group a stub group until the size is just under GROUP_SIZE. |
| // The last input section in the group will be used as the stub table. |
| FINDING_STUB_SECTION, |
| // A group is being built and we have already found a stub table. |
| // We enter this state to grow a stub group by adding input section |
| // after the stub table. This effectively doubles the group size. |
| HAS_STUB_SECTION |
| } State; |
| |
| // Any newly created relaxed sections are stored here. |
| std::vector<Output_relaxed_input_section*> new_relaxed_sections; |
| |
| State state = NO_GROUP; |
| section_size_type off = 0; |
| section_size_type group_begin_offset = 0; |
| section_size_type group_end_offset = 0; |
| section_size_type stub_table_end_offset = 0; |
| Input_section_list::const_iterator group_begin = |
| this->input_sections().end(); |
| Input_section_list::const_iterator stub_table = |
| this->input_sections().end(); |
| Input_section_list::const_iterator group_end = this->input_sections().end(); |
| for (Input_section_list::const_iterator p = this->input_sections().begin(); |
| p != this->input_sections().end(); |
| ++p) |
| { |
| section_size_type section_begin_offset = |
| align_address(off, p->addralign()); |
| section_size_type section_end_offset = |
| section_begin_offset + p->data_size(); |
| |
| // Check to see if we should group the previously seens sections. |
| switch (state) |
| { |
| case NO_GROUP: |
| break; |
| |
| case FINDING_STUB_SECTION: |
| // Adding this section makes the group larger than GROUP_SIZE. |
| if (section_end_offset - group_begin_offset >= group_size) |
| { |
| if (stubs_always_after_branch) |
| { |
| gold_assert(group_end != this->input_sections().end()); |
| this->create_stub_group(group_begin, group_end, group_end, |
| target, &new_relaxed_sections); |
| state = NO_GROUP; |
| } |
| else |
| { |
| // But wait, there's more! Input sections up to |
| // stub_group_size bytes after the stub table can be |
| // handled by it too. |
| state = HAS_STUB_SECTION; |
| stub_table = group_end; |
| stub_table_end_offset = group_end_offset; |
| } |
| } |
| break; |
| |
| case HAS_STUB_SECTION: |
| // Adding this section makes the post stub-section group larger |
| // than GROUP_SIZE. |
| if (section_end_offset - stub_table_end_offset >= group_size) |
| { |
| gold_assert(group_end != this->input_sections().end()); |
| this->create_stub_group(group_begin, group_end, stub_table, |
| target, &new_relaxed_sections); |
| state = NO_GROUP; |
| } |
| break; |
| |
| default: |
| gold_unreachable(); |
| } |
| |
| // If we see an input section and currently there is no group, start |
| // a new one. Skip any empty sections. |
| if ((p->is_input_section() || p->is_relaxed_input_section()) |
| && (p->relobj()->section_size(p->shndx()) != 0)) |
| { |
| if (state == NO_GROUP) |
| { |
| state = FINDING_STUB_SECTION; |
| group_begin = p; |
| group_begin_offset = section_begin_offset; |
| } |
| |
| // Keep track of the last input section seen. |
| group_end = p; |
| group_end_offset = section_end_offset; |
| } |
| |
| off = section_end_offset; |
| } |
| |
| // Create a stub group for any ungrouped sections. |
| if (state == FINDING_STUB_SECTION || state == HAS_STUB_SECTION) |
| { |
| gold_assert(group_end != this->input_sections().end()); |
| this->create_stub_group(group_begin, group_end, |
| (state == FINDING_STUB_SECTION |
| ? group_end |
| : stub_table), |
| target, &new_relaxed_sections); |
| } |
| |
| // Convert input section into relaxed input section in a batch. |
| if (!new_relaxed_sections.empty()) |
| this->convert_input_sections_to_relaxed_sections(new_relaxed_sections); |
| |
| // Update the section offsets |
| for (size_t i = 0; i < new_relaxed_sections.size(); ++i) |
| { |
| Arm_relobj<big_endian>* arm_relobj = |
| Arm_relobj<big_endian>::as_arm_relobj( |
| new_relaxed_sections[i]->relobj()); |
| unsigned int shndx = new_relaxed_sections[i]->shndx(); |
| // Tell Arm_relobj that this input section is converted. |
| arm_relobj->convert_input_section_to_relaxed_section(shndx); |
| } |
| } |
| |
| // Arm_relobj methods. |
| |
| // Scan relocations for stub generation. |
| |
| template<bool big_endian> |
| void |
| Arm_relobj<big_endian>::scan_sections_for_stubs( |
| Target_arm<big_endian>* arm_target, |
| const Symbol_table* symtab, |
| const Layout* layout) |
| { |
| unsigned int shnum = this->shnum(); |
| const unsigned int shdr_size = elfcpp::Elf_sizes<32>::shdr_size; |
| |
| // Read the section headers. |
| const unsigned char* pshdrs = this->get_view(this->elf_file()->shoff(), |
| shnum * shdr_size, |
| true, true); |
| |
| // To speed up processing, we set up hash tables for fast lookup of |
| // input offsets to output addresses. |
| this->initialize_input_to_output_maps(); |
| |
| const Relobj::Output_sections& out_sections(this->output_sections()); |
| |
| Relocate_info<32, big_endian> relinfo; |
| relinfo.symtab = symtab; |
| relinfo.layout = layout; |
| relinfo.object = this; |
| |
| const unsigned char* p = pshdrs + shdr_size; |
| for (unsigned int i = 1; i < shnum; ++i, p += shdr_size) |
| { |
| typename elfcpp::Shdr<32, big_endian> shdr(p); |
| |
| unsigned int sh_type = shdr.get_sh_type(); |
| if (sh_type != elfcpp::SHT_REL && sh_type != elfcpp::SHT_RELA) |
| continue; |
| |
| off_t sh_size = shdr.get_sh_size(); |
| if (sh_size == 0) |
| continue; |
| |
| unsigned int index = this->adjust_shndx(shdr.get_sh_info()); |
| if (index >= this->shnum()) |
| { |
| // Ignore reloc section with bad info. This error will be |
| // reported in the final link. |
| continue; |
| } |
| |
| Output_section* os = out_sections[index]; |
| if (os == NULL |
| || symtab->is_section_folded(this, index)) |
| { |
| // This relocation section is against a section which we |
| // discarded or if the section is folded into another |
| // section due to ICF. |
| continue; |
| } |
| Arm_address output_offset = this->get_output_section_offset(index); |
| |
| if (this->adjust_shndx(shdr.get_sh_link()) != this->symtab_shndx()) |
| { |
| // Ignore reloc section with unexpected symbol table. The |
| // error will be reported in the final link. |
| continue; |
| } |
| |
| const unsigned char* prelocs = this->get_view(shdr.get_sh_offset(), |
| sh_size, true, false); |
| |
| unsigned int reloc_size; |
| if (sh_type == elfcpp::SHT_REL) |
| reloc_size = elfcpp::Elf_sizes<32>::rel_size; |
| else |
| reloc_size = elfcpp::Elf_sizes<32>::rela_size; |
| |
| if (reloc_size != shdr.get_sh_entsize()) |
| { |
| // Ignore reloc section with unexpected entsize. The error |
| // will be reported in the final link. |
| continue; |
| } |
| |
| size_t reloc_count = sh_size / reloc_size; |
| if (static_cast<off_t>(reloc_count * reloc_size) != sh_size) |
| { |
| // Ignore reloc section with uneven size. The error will be |
| // reported in the final link. |
| continue; |
| } |
| |
| gold_assert(output_offset != invalid_address |
| || this->relocs_must_follow_section_writes()); |
| |
| // Get the section contents. This does work for the case in which |
| // we modify the contents of an input section. We need to pass the |
| // output view under such circumstances. |
| section_size_type input_view_size = 0; |
| const unsigned char* input_view = |
| this->section_contents(index, &input_view_size, false); |
| |
| relinfo.reloc_shndx = i; |
| relinfo.data_shndx = index; |
| arm_target->scan_section_for_stubs(&relinfo, sh_type, prelocs, |
| reloc_count, os, |
| output_offset == invalid_address, |
| input_view, |
| os->address(), |
| input_view_size); |
| } |
| |
| // After we've done the relocations, we release the hash tables, |
| // since we no longer need them. |
| this->free_input_to_output_maps(); |
| } |
| |
| // Count the local symbols. The ARM backend needs to know if a symbol |
| // is a THUMB function or not. For global symbols, it is easy because |
| // the Symbol object keeps the ELF symbol type. For local symbol it is |
| // harder because we cannot access this information. So we override the |
| // do_count_local_symbol in parent and scan local symbols to mark |
| // THUMB functions. This is not the most efficient way but I do not want to |
| // slow down other ports by calling a per symbol targer hook inside |
| // Sized_relobj<size, big_endian>::do_count_local_symbols. |
| |
| template<bool big_endian> |
| void |
| Arm_relobj<big_endian>::do_count_local_symbols( |
| Stringpool_template<char>* pool, |
| Stringpool_template<char>* dynpool) |
| { |
| // We need to fix-up the values of any local symbols whose type are |
| // STT_ARM_TFUNC. |
| |
| // Ask parent to count the local symbols. |
| Sized_relobj<32, big_endian>::do_count_local_symbols(pool, dynpool); |
| const unsigned int loccount = this->local_symbol_count(); |
| if (loccount == 0) |
| return; |
| |
| // Intialize the thumb function bit-vector. |
| std::vector<bool> empty_vector(loccount, false); |
| this->local_symbol_is_thumb_function_.swap(empty_vector); |
| |
| // Read the symbol table section header. |
| const unsigned int symtab_shndx = this->symtab_shndx(); |
| elfcpp::Shdr<32, big_endian> |
| symtabshdr(this, this->elf_file()->section_header(symtab_shndx)); |
| gold_assert(symtabshdr.get_sh_type() == elfcpp::SHT_SYMTAB); |
| |
| // Read the local symbols. |
| const int sym_size =elfcpp::Elf_sizes<32>::sym_size; |
| gold_assert(loccount == symtabshdr.get_sh_info()); |
| off_t locsize = loccount * sym_size; |
| const unsigned char* psyms = this->get_view(symtabshdr.get_sh_offset(), |
| locsize, true, true); |
| |
| // Loop over the local symbols and mark any local symbols pointing |
| // to THUMB functions. |
| |
| // Skip the first dummy symbol. |
| psyms += sym_size; |
| typename Sized_relobj<32, big_endian>::Local_values* plocal_values = |
| this->local_values(); |
| for (unsigned int i = 1; i < loccount; ++i, psyms += sym_size) |
| { |
| elfcpp::Sym<32, big_endian> sym(psyms); |
| elfcpp::STT st_type = sym.get_st_type(); |
| Symbol_value<32>& lv((*plocal_values)[i]); |
| Arm_address input_value = lv.input_value(); |
| |
| if (st_type == elfcpp::STT_ARM_TFUNC |
| || (st_type == elfcpp::STT_FUNC && ((input_value & 1) != 0))) |
| { |
| // This is a THUMB function. Mark this and canonicalize the |
| // symbol value by setting LSB. |
| this->local_symbol_is_thumb_function_[i] = true; |
| if ((input_value & 1) == 0) |
| lv.set_input_value(input_value | 1); |
| } |
| } |
| } |
| |
| // Relocate sections. |
| template<bool big_endian> |
| void |
| Arm_relobj<big_endian>::do_relocate_sections( |
| const Symbol_table* symtab, |
| const Layout* layout, |
| const unsigned char* pshdrs, |
| typename Sized_relobj<32, big_endian>::Views* pviews) |
| { |
| // Call parent to relocate sections. |
| Sized_relobj<32, big_endian>::do_relocate_sections(symtab, layout, pshdrs, |
| pviews); |
| |
| // We do not generate stubs if doing a relocatable link. |
| if (parameters->options().relocatable()) |
| return; |
| |
| // Relocate stub tables. |
| unsigned int shnum = this->shnum(); |
| |
| Target_arm<big_endian>* arm_target = |
| Target_arm<big_endian>::default_target(); |
| |
| Relocate_info<32, big_endian> relinfo; |
| relinfo.symtab = symtab; |
| relinfo.layout = layout; |
| relinfo.object = this; |
| |
| for (unsigned int i = 1; i < shnum; ++i) |
| { |
| Arm_input_section<big_endian>* arm_input_section = |
| arm_target->find_arm_input_section(this, i); |
| |
| if (arm_input_section == NULL |
| || !arm_input_section->is_stub_table_owner() |
| || arm_input_section->stub_table()->empty()) |
| continue; |
| |
| // We cannot discard a section if it owns a stub table. |
| Output_section* os = this->output_section(i); |
| gold_assert(os != NULL); |
| |
| relinfo.reloc_shndx = elfcpp::SHN_UNDEF; |
| relinfo.reloc_shdr = NULL; |
| relinfo.data_shndx = i; |
| relinfo.data_shdr = pshdrs + i * elfcpp::Elf_sizes<32>::shdr_size; |
| |
| gold_assert((*pviews)[i].view != NULL); |
| |
| // We are passed the output section view. Adjust it to cover the |
| // stub table only. |
| Stub_table<big_endian>* stub_table = arm_input_section->stub_table(); |
| gold_assert((stub_table->address() >= (*pviews)[i].address) |
| && ((stub_table->address() + stub_table->data_size()) |
| <= (*pviews)[i].address + (*pviews)[i].view_size)); |
| |
| off_t offset = stub_table->address() - (*pviews)[i].address; |
| unsigned char* view = (*pviews)[i].view + offset; |
| Arm_address address = stub_table->address(); |
| section_size_type view_size = stub_table->data_size(); |
| |
| stub_table->relocate_stubs(&relinfo, arm_target, os, view, address, |
| view_size); |
| } |
| } |
| |
| // Helper functions for both Arm_relobj and Arm_dynobj to read ARM |
| // ABI information. |
| |
| template<bool big_endian> |
| Attributes_section_data* |
| read_arm_attributes_section( |
| Object* object, |
| Read_symbols_data *sd) |
| { |
| // Read the attributes section if there is one. |
| // We read from the end because gas seems to put it near the end of |
| // the section headers. |
| const size_t shdr_size = elfcpp::Elf_sizes<32>::shdr_size; |
| const unsigned char *ps = |
| sd->section_headers->data() + shdr_size * (object->shnum() - 1); |
| for (unsigned int i = object->shnum(); i > 0; --i, ps -= shdr_size) |
| { |
| elfcpp::Shdr<32, big_endian> shdr(ps); |
| if (shdr.get_sh_type() == elfcpp::SHT_ARM_ATTRIBUTES) |
| { |
| section_offset_type section_offset = shdr.get_sh_offset(); |
| section_size_type section_size = |
| convert_to_section_size_type(shdr.get_sh_size()); |
| File_view* view = object->get_lasting_view(section_offset, |
| section_size, true, false); |
| return new Attributes_section_data(view->data(), section_size); |
| } |
| } |
| return NULL; |
| } |
| |
| // Read the symbol information. |
| |
| template<bool big_endian> |
| void |
| Arm_relobj<big_endian>::do_read_symbols(Read_symbols_data* sd) |
| { |
| // Call parent class to read symbol information. |
| Sized_relobj<32, big_endian>::do_read_symbols(sd); |
| |
| // Read processor-specific flags in ELF file header. |
| const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset, |
| elfcpp::Elf_sizes<32>::ehdr_size, |
| true, false); |
| elfcpp::Ehdr<32, big_endian> ehdr(pehdr); |
| this->processor_specific_flags_ = ehdr.get_e_flags(); |
| this->attributes_section_data_ = |
| read_arm_attributes_section<big_endian>(this, sd); |
| } |
| |
| // Arm_dynobj methods. |
| |
| // Read the symbol information. |
| |
| template<bool big_endian> |
| void |
| Arm_dynobj<big_endian>::do_read_symbols(Read_symbols_data* sd) |
| { |
| // Call parent class to read symbol information. |
| Sized_dynobj<32, big_endian>::do_read_symbols(sd); |
| |
| // Read processor-specific flags in ELF file header. |
| const unsigned char* pehdr = this->get_view(elfcpp::file_header_offset, |
| elfcpp::Elf_sizes<32>::ehdr_size, |
| true, false); |
| elfcpp::Ehdr<32, big_endian> ehdr(pehdr); |
| this->processor_specific_flags_ = ehdr.get_e_flags(); |
| this->attributes_section_data_ = |
| read_arm_attributes_section<big_endian>(this, sd); |
| } |
| |
| // Stub_addend_reader methods. |
| |
| // Read the addend of a REL relocation of type R_TYPE at VIEW. |
| |
| template<bool big_endian> |
| elfcpp::Elf_types<32>::Elf_Swxword |
| Stub_addend_reader<elfcpp::SHT_REL, big_endian>::operator()( |
| unsigned int r_type, |
| const unsigned char* view, |
| const typename Reloc_types<elfcpp::SHT_REL, 32, big_endian>::Reloc&) const |
| { |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_CALL: |
| case elfcpp::R_ARM_JUMP24: |
| case elfcpp::R_ARM_PLT32: |
| { |
| typedef typename elfcpp::Swap<32, big_endian>::Valtype Valtype; |
| const Valtype* wv = reinterpret_cast<const Valtype*>(view); |
| Valtype val = elfcpp::Swap<32, big_endian>::readval(wv); |
| return utils::sign_extend<26>(val << 2); |
| } |
| |
| case elfcpp::R_ARM_THM_CALL: |
| case elfcpp::R_ARM_THM_JUMP24: |
| case elfcpp::R_ARM_THM_XPC22: |
| { |
| // Fetch the addend. We use the Thumb-2 encoding (backwards |
| // compatible with Thumb-1) involving the J1 and J2 bits. |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| const Valtype* wv = reinterpret_cast<const Valtype*>(view); |
| Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv); |
| Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1); |
| |
| uint32_t s = (upper_insn & (1 << 10)) >> 10; |
| uint32_t upper = upper_insn & 0x3ff; |
| uint32_t lower = lower_insn & 0x7ff; |
| uint32_t j1 = (lower_insn & (1 << 13)) >> 13; |
| uint32_t j2 = (lower_insn & (1 << 11)) >> 11; |
| uint32_t i1 = j1 ^ s ? 0 : 1; |
| uint32_t i2 = j2 ^ s ? 0 : 1; |
| |
| return utils::sign_extend<25>((s << 24) | (i1 << 23) | (i2 << 22) |
| | (upper << 12) | (lower << 1)); |
| } |
| |
| case elfcpp::R_ARM_THM_JUMP19: |
| { |
| typedef typename elfcpp::Swap<16, big_endian>::Valtype Valtype; |
| const Valtype* wv = reinterpret_cast<const Valtype*>(view); |
| Valtype upper_insn = elfcpp::Swap<16, big_endian>::readval(wv); |
| Valtype lower_insn = elfcpp::Swap<16, big_endian>::readval(wv + 1); |
| |
| // Reconstruct the top three bits and squish the two 11 bit pieces |
| // together. |
| uint32_t S = (upper_insn & 0x0400) >> 10; |
| uint32_t J1 = (lower_insn & 0x2000) >> 13; |
| uint32_t J2 = (lower_insn & 0x0800) >> 11; |
| uint32_t upper = |
| (S << 8) | (J2 << 7) | (J1 << 6) | (upper_insn & 0x003f); |
| uint32_t lower = (lower_insn & 0x07ff); |
| return utils::sign_extend<23>((upper << 12) | (lower << 1)); |
| } |
| |
| default: |
| gold_unreachable(); |
| } |
| } |
| |
| // A class to handle the PLT data. |
| |
| template<bool big_endian> |
| class Output_data_plt_arm : public Output_section_data |
| { |
| public: |
| typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, big_endian> |
| Reloc_section; |
| |
| Output_data_plt_arm(Layout*, Output_data_space*); |
| |
| // Add an entry to the PLT. |
| void |
| add_entry(Symbol* gsym); |
| |
| // Return the .rel.plt section data. |
| const Reloc_section* |
| rel_plt() const |
| { return this->rel_; } |
| |
| protected: |
| void |
| do_adjust_output_section(Output_section* os); |
| |
| // Write to a map file. |
| void |
| do_print_to_mapfile(Mapfile* mapfile) const |
| { mapfile->print_output_data(this, _("** PLT")); } |
| |
| private: |
| // Template for the first PLT entry. |
| static const uint32_t first_plt_entry[5]; |
| |
| // Template for subsequent PLT entries. |
| static const uint32_t plt_entry[3]; |
| |
| // Set the final size. |
| void |
| set_final_data_size() |
| { |
| this->set_data_size(sizeof(first_plt_entry) |
| + this->count_ * sizeof(plt_entry)); |
| } |
| |
| // Write out the PLT data. |
| void |
| do_write(Output_file*); |
| |
| // The reloc section. |
| Reloc_section* rel_; |
| // The .got.plt section. |
| Output_data_space* got_plt_; |
| // The number of PLT entries. |
| unsigned int count_; |
| }; |
| |
| // Create the PLT section. The ordinary .got section is an argument, |
| // since we need to refer to the start. We also create our own .got |
| // section just for PLT entries. |
| |
| template<bool big_endian> |
| Output_data_plt_arm<big_endian>::Output_data_plt_arm(Layout* layout, |
| Output_data_space* got_plt) |
| : Output_section_data(4), got_plt_(got_plt), count_(0) |
| { |
| this->rel_ = new Reloc_section(false); |
| layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, |
| elfcpp::SHF_ALLOC, this->rel_, true); |
| } |
| |
| template<bool big_endian> |
| void |
| Output_data_plt_arm<big_endian>::do_adjust_output_section(Output_section* os) |
| { |
| os->set_entsize(0); |
| } |
| |
| // Add an entry to the PLT. |
| |
| template<bool big_endian> |
| void |
| Output_data_plt_arm<big_endian>::add_entry(Symbol* gsym) |
| { |
| gold_assert(!gsym->has_plt_offset()); |
| |
| // Note that when setting the PLT offset we skip the initial |
| // reserved PLT entry. |
| gsym->set_plt_offset((this->count_) * sizeof(plt_entry) |
| + sizeof(first_plt_entry)); |
| |
| ++this->count_; |
| |
| section_offset_type got_offset = this->got_plt_->current_data_size(); |
| |
| // Every PLT entry needs a GOT entry which points back to the PLT |
| // entry (this will be changed by the dynamic linker, normally |
| // lazily when the function is called). |
| this->got_plt_->set_current_data_size(got_offset + 4); |
| |
| // Every PLT entry needs a reloc. |
| gsym->set_needs_dynsym_entry(); |
| this->rel_->add_global(gsym, elfcpp::R_ARM_JUMP_SLOT, this->got_plt_, |
| got_offset); |
| |
| // Note that we don't need to save the symbol. The contents of the |
| // PLT are independent of which symbols are used. The symbols only |
| // appear in the relocations. |
| } |
| |
| // ARM PLTs. |
| // FIXME: This is not very flexible. Right now this has only been tested |
| // on armv5te. If we are to support additional architecture features like |
| // Thumb-2 or BE8, we need to make this more flexible like GNU ld. |
| |
| // The first entry in the PLT. |
| template<bool big_endian> |
| const uint32_t Output_data_plt_arm<big_endian>::first_plt_entry[5] = |
| { |
| 0xe52de004, // str lr, [sp, #-4]! |
| 0xe59fe004, // ldr lr, [pc, #4] |
| 0xe08fe00e, // add lr, pc, lr |
| 0xe5bef008, // ldr pc, [lr, #8]! |
| 0x00000000, // &GOT[0] - . |
| }; |
| |
| // Subsequent entries in the PLT. |
| |
| template<bool big_endian> |
| const uint32_t Output_data_plt_arm<big_endian>::plt_entry[3] = |
| { |
| 0xe28fc600, // add ip, pc, #0xNN00000 |
| 0xe28cca00, // add ip, ip, #0xNN000 |
| 0xe5bcf000, // ldr pc, [ip, #0xNNN]! |
| }; |
| |
| // Write out the PLT. This uses the hand-coded instructions above, |
| // and adjusts them as needed. This is all specified by the arm ELF |
| // Processor Supplement. |
| |
| template<bool big_endian> |
| void |
| Output_data_plt_arm<big_endian>::do_write(Output_file* of) |
| { |
| const off_t offset = this->offset(); |
| const section_size_type oview_size = |
| convert_to_section_size_type(this->data_size()); |
| unsigned char* const oview = of->get_output_view(offset, oview_size); |
| |
| const off_t got_file_offset = this->got_plt_->offset(); |
| const section_size_type got_size = |
| convert_to_section_size_type(this->got_plt_->data_size()); |
| unsigned char* const got_view = of->get_output_view(got_file_offset, |
| got_size); |
| unsigned char* pov = oview; |
| |
| Arm_address plt_address = this->address(); |
| Arm_address got_address = this->got_plt_->address(); |
| |
| // Write first PLT entry. All but the last word are constants. |
| const size_t num_first_plt_words = (sizeof(first_plt_entry) |
| / sizeof(plt_entry[0])); |
| for (size_t i = 0; i < num_first_plt_words - 1; i++) |
| elfcpp::Swap<32, big_endian>::writeval(pov + i * 4, first_plt_entry[i]); |
| // Last word in first PLT entry is &GOT[0] - . |
| elfcpp::Swap<32, big_endian>::writeval(pov + 16, |
| got_address - (plt_address + 16)); |
| pov += sizeof(first_plt_entry); |
| |
| unsigned char* got_pov = got_view; |
| |
| memset(got_pov, 0, 12); |
| got_pov += 12; |
| |
| const int rel_size = elfcpp::Elf_sizes<32>::rel_size; |
| unsigned int plt_offset = sizeof(first_plt_entry); |
| unsigned int plt_rel_offset = 0; |
| unsigned int got_offset = 12; |
| const unsigned int count = this->count_; |
| for (unsigned int i = 0; |
| i < count; |
| ++i, |
| pov += sizeof(plt_entry), |
| got_pov += 4, |
| plt_offset += sizeof(plt_entry), |
| plt_rel_offset += rel_size, |
| got_offset += 4) |
| { |
| // Set and adjust the PLT entry itself. |
| int32_t offset = ((got_address + got_offset) |
| - (plt_address + plt_offset + 8)); |
| |
| gold_assert(offset >= 0 && offset < 0x0fffffff); |
| uint32_t plt_insn0 = plt_entry[0] | ((offset >> 20) & 0xff); |
| elfcpp::Swap<32, big_endian>::writeval(pov, plt_insn0); |
| uint32_t plt_insn1 = plt_entry[1] | ((offset >> 12) & 0xff); |
| elfcpp::Swap<32, big_endian>::writeval(pov + 4, plt_insn1); |
| uint32_t plt_insn2 = plt_entry[2] | (offset & 0xfff); |
| elfcpp::Swap<32, big_endian>::writeval(pov + 8, plt_insn2); |
| |
| // Set the entry in the GOT. |
| elfcpp::Swap<32, big_endian>::writeval(got_pov, plt_address); |
| } |
| |
| gold_assert(static_cast<section_size_type>(pov - oview) == oview_size); |
| gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size); |
| |
| of->write_output_view(offset, oview_size, oview); |
| of->write_output_view(got_file_offset, got_size, got_view); |
| } |
| |
| // Create a PLT entry for a global symbol. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::make_plt_entry(Symbol_table* symtab, Layout* layout, |
| Symbol* gsym) |
| { |
| if (gsym->has_plt_offset()) |
| return; |
| |
| if (this->plt_ == NULL) |
| { |
| // Create the GOT sections first. |
| this->got_section(symtab, layout); |
| |
| this->plt_ = new Output_data_plt_arm<big_endian>(layout, this->got_plt_); |
| layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
| (elfcpp::SHF_ALLOC |
| | elfcpp::SHF_EXECINSTR), |
| this->plt_, false); |
| } |
| this->plt_->add_entry(gsym); |
| } |
| |
| // Report an unsupported relocation against a local symbol. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::Scan::unsupported_reloc_local( |
| Sized_relobj<32, big_endian>* object, |
| unsigned int r_type) |
| { |
| gold_error(_("%s: unsupported reloc %u against local symbol"), |
| object->name().c_str(), r_type); |
| } |
| |
| // We are about to emit a dynamic relocation of type R_TYPE. If the |
| // dynamic linker does not support it, issue an error. The GNU linker |
| // only issues a non-PIC error for an allocated read-only section. |
| // Here we know the section is allocated, but we don't know that it is |
| // read-only. But we check for all the relocation types which the |
| // glibc dynamic linker supports, so it seems appropriate to issue an |
| // error even if the section is not read-only. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::Scan::check_non_pic(Relobj* object, |
| unsigned int r_type) |
| { |
| switch (r_type) |
| { |
| // These are the relocation types supported by glibc for ARM. |
| case elfcpp::R_ARM_RELATIVE: |
| case elfcpp::R_ARM_COPY: |
| case elfcpp::R_ARM_GLOB_DAT: |
| case elfcpp::R_ARM_JUMP_SLOT: |
| case elfcpp::R_ARM_ABS32: |
| case elfcpp::R_ARM_ABS32_NOI: |
| case elfcpp::R_ARM_PC24: |
| // FIXME: The following 3 types are not supported by Android's dynamic |
| // linker. |
| case elfcpp::R_ARM_TLS_DTPMOD32: |
| case elfcpp::R_ARM_TLS_DTPOFF32: |
| case elfcpp::R_ARM_TLS_TPOFF32: |
| return; |
| |
| default: |
| // This prevents us from issuing more than one error per reloc |
| // section. But we can still wind up issuing more than one |
| // error per object file. |
| if (this->issued_non_pic_error_) |
| return; |
| object->error(_("requires unsupported dynamic reloc; " |
| "recompile with -fPIC")); |
| this->issued_non_pic_error_ = true; |
| return; |
| |
| case elfcpp::R_ARM_NONE: |
| gold_unreachable(); |
| } |
| } |
| |
| // Scan a relocation for a local symbol. |
| // FIXME: This only handles a subset of relocation types used by Android |
| // on ARM v5te devices. |
| |
| template<bool big_endian> |
| inline void |
| Target_arm<big_endian>::Scan::local(Symbol_table* symtab, |
| Layout* layout, |
| Target_arm* target, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| Output_section* output_section, |
| const elfcpp::Rel<32, big_endian>& reloc, |
| unsigned int r_type, |
| const elfcpp::Sym<32, big_endian>&) |
| { |
| r_type = get_real_reloc_type(r_type); |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_NONE: |
| break; |
| |
| case elfcpp::R_ARM_ABS32: |
| case elfcpp::R_ARM_ABS32_NOI: |
| // If building a shared library (or a position-independent |
| // executable), we need to create a dynamic relocation for |
| // this location. The relocation applied at link time will |
| // apply the link-time value, so we flag the location with |
| // an R_ARM_RELATIVE relocation so the dynamic loader can |
| // relocate it easily. |
| if (parameters->options().output_is_position_independent()) |
| { |
| Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| // If we are to add more other reloc types than R_ARM_ABS32, |
| // we need to add check_non_pic(object, r_type) here. |
| rel_dyn->add_local_relative(object, r_sym, elfcpp::R_ARM_RELATIVE, |
| output_section, data_shndx, |
| reloc.get_r_offset()); |
| } |
| break; |
| |
| case elfcpp::R_ARM_REL32: |
| case elfcpp::R_ARM_THM_CALL: |
| case elfcpp::R_ARM_CALL: |
| case elfcpp::R_ARM_PREL31: |
| case elfcpp::R_ARM_JUMP24: |
| case elfcpp::R_ARM_PLT32: |
| case elfcpp::R_ARM_THM_ABS5: |
| case elfcpp::R_ARM_ABS8: |
| case elfcpp::R_ARM_ABS12: |
| case elfcpp::R_ARM_ABS16: |
| case elfcpp::R_ARM_BASE_ABS: |
| case elfcpp::R_ARM_MOVW_ABS_NC: |
| case elfcpp::R_ARM_MOVT_ABS: |
| case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
| case elfcpp::R_ARM_THM_MOVT_ABS: |
| case elfcpp::R_ARM_MOVW_PREL_NC: |
| case elfcpp::R_ARM_MOVT_PREL: |
| case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
| case elfcpp::R_ARM_THM_MOVT_PREL: |
| break; |
| |
| case elfcpp::R_ARM_GOTOFF32: |
| // We need a GOT section: |
| target->got_section(symtab, layout); |
| break; |
| |
| case elfcpp::R_ARM_BASE_PREL: |
| // FIXME: What about this? |
| break; |
| |
| case elfcpp::R_ARM_GOT_BREL: |
| case elfcpp::R_ARM_GOT_PREL: |
| { |
| // The symbol requires a GOT entry. |
| Output_data_got<32, big_endian>* got = |
| target->got_section(symtab, layout); |
| unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| if (got->add_local(object, r_sym, GOT_TYPE_STANDARD)) |
| { |
| // If we are generating a shared object, we need to add a |
| // dynamic RELATIVE relocation for this symbol's GOT entry. |
| if (parameters->options().output_is_position_independent()) |
| { |
| Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info()); |
| rel_dyn->add_local_relative( |
| object, r_sym, elfcpp::R_ARM_RELATIVE, got, |
| object->local_got_offset(r_sym, GOT_TYPE_STANDARD)); |
| } |
| } |
| } |
| break; |
| |
| case elfcpp::R_ARM_TARGET1: |
| // This should have been mapped to another type already. |
| // Fall through. |
| case elfcpp::R_ARM_COPY: |
| case elfcpp::R_ARM_GLOB_DAT: |
| case elfcpp::R_ARM_JUMP_SLOT: |
| case elfcpp::R_ARM_RELATIVE: |
| // These are relocations which should only be seen by the |
| // dynamic linker, and should never be seen here. |
| gold_error(_("%s: unexpected reloc %u in object file"), |
| object->name().c_str(), r_type); |
| break; |
| |
| default: |
| unsupported_reloc_local(object, r_type); |
| break; |
| } |
| } |
| |
| // Report an unsupported relocation against a global symbol. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::Scan::unsupported_reloc_global( |
| Sized_relobj<32, big_endian>* object, |
| unsigned int r_type, |
| Symbol* gsym) |
| { |
| gold_error(_("%s: unsupported reloc %u against global symbol %s"), |
| object->name().c_str(), r_type, gsym->demangled_name().c_str()); |
| } |
| |
| // Scan a relocation for a global symbol. |
| // FIXME: This only handles a subset of relocation types used by Android |
| // on ARM v5te devices. |
| |
| template<bool big_endian> |
| inline void |
| Target_arm<big_endian>::Scan::global(Symbol_table* symtab, |
| Layout* layout, |
| Target_arm* target, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| Output_section* output_section, |
| const elfcpp::Rel<32, big_endian>& reloc, |
| unsigned int r_type, |
| Symbol* gsym) |
| { |
| r_type = get_real_reloc_type(r_type); |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_NONE: |
| break; |
| |
| case elfcpp::R_ARM_ABS32: |
| case elfcpp::R_ARM_ABS32_NOI: |
| { |
| // Make a dynamic relocation if necessary. |
| if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF)) |
| { |
| if (target->may_need_copy_reloc(gsym)) |
| { |
| target->copy_reloc(symtab, layout, object, |
| data_shndx, output_section, gsym, reloc); |
| } |
| else if (gsym->can_use_relative_reloc(false)) |
| { |
| // If we are to add more other reloc types than R_ARM_ABS32, |
| // we need to add check_non_pic(object, r_type) here. |
| Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| rel_dyn->add_global_relative(gsym, elfcpp::R_ARM_RELATIVE, |
| output_section, object, |
| data_shndx, reloc.get_r_offset()); |
| } |
| else |
| { |
| // If we are to add more other reloc types than R_ARM_ABS32, |
| // we need to add check_non_pic(object, r_type) here. |
| Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| rel_dyn->add_global(gsym, r_type, output_section, object, |
| data_shndx, reloc.get_r_offset()); |
| } |
| } |
| } |
| break; |
| |
| case elfcpp::R_ARM_MOVW_ABS_NC: |
| case elfcpp::R_ARM_MOVT_ABS: |
| case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
| case elfcpp::R_ARM_THM_MOVT_ABS: |
| case elfcpp::R_ARM_MOVW_PREL_NC: |
| case elfcpp::R_ARM_MOVT_PREL: |
| case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
| case elfcpp::R_ARM_THM_MOVT_PREL: |
| break; |
| |
| case elfcpp::R_ARM_THM_ABS5: |
| case elfcpp::R_ARM_ABS8: |
| case elfcpp::R_ARM_ABS12: |
| case elfcpp::R_ARM_ABS16: |
| case elfcpp::R_ARM_BASE_ABS: |
| { |
| // No dynamic relocs of this kinds. |
| // Report the error in case of PIC. |
| int flags = Symbol::NON_PIC_REF; |
| if (gsym->type() == elfcpp::STT_FUNC |
| || gsym->type() == elfcpp::STT_ARM_TFUNC) |
| flags |= Symbol::FUNCTION_CALL; |
| if (gsym->needs_dynamic_reloc(flags)) |
| check_non_pic(object, r_type); |
| } |
| break; |
| |
| case elfcpp::R_ARM_REL32: |
| case elfcpp::R_ARM_PREL31: |
| { |
| // Make a dynamic relocation if necessary. |
| int flags = Symbol::NON_PIC_REF; |
| if (gsym->needs_dynamic_reloc(flags)) |
| { |
| if (target->may_need_copy_reloc(gsym)) |
| { |
| target->copy_reloc(symtab, layout, object, |
| data_shndx, output_section, gsym, reloc); |
| } |
| else |
| { |
| check_non_pic(object, r_type); |
| Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| rel_dyn->add_global(gsym, r_type, output_section, object, |
| data_shndx, reloc.get_r_offset()); |
| } |
| } |
| } |
| break; |
| |
| case elfcpp::R_ARM_JUMP24: |
| case elfcpp::R_ARM_THM_JUMP24: |
| case elfcpp::R_ARM_CALL: |
| case elfcpp::R_ARM_THM_CALL: |
| |
| if (Target_arm<big_endian>::Scan::symbol_needs_plt_entry(gsym)) |
| target->make_plt_entry(symtab, layout, gsym); |
| else |
| { |
| // Check to see if this is a function that would need a PLT |
| // but does not get one because the function symbol is untyped. |
| // This happens in assembly code missing a proper .type directive. |
| if ((!gsym->is_undefined() || parameters->options().shared()) |
| && !parameters->doing_static_link() |
| && gsym->type() == elfcpp::STT_NOTYPE |
| && (gsym->is_from_dynobj() |
| || gsym->is_undefined() |
| || gsym->is_preemptible())) |
| gold_error(_("%s is not a function."), |
| gsym->demangled_name().c_str()); |
| } |
| break; |
| |
| case elfcpp::R_ARM_PLT32: |
| // If the symbol is fully resolved, this is just a relative |
| // local reloc. Otherwise we need a PLT entry. |
| if (gsym->final_value_is_known()) |
| break; |
| // If building a shared library, we can also skip the PLT entry |
| // if the symbol is defined in the output file and is protected |
| // or hidden. |
| if (gsym->is_defined() |
| && !gsym->is_from_dynobj() |
| && !gsym->is_preemptible()) |
| break; |
| target->make_plt_entry(symtab, layout, gsym); |
| break; |
| |
| case elfcpp::R_ARM_GOTOFF32: |
| // We need a GOT section. |
| target->got_section(symtab, layout); |
| break; |
| |
| case elfcpp::R_ARM_BASE_PREL: |
| // FIXME: What about this? |
| break; |
| |
| case elfcpp::R_ARM_GOT_BREL: |
| case elfcpp::R_ARM_GOT_PREL: |
| { |
| // The symbol requires a GOT entry. |
| Output_data_got<32, big_endian>* got = |
| target->got_section(symtab, layout); |
| if (gsym->final_value_is_known()) |
| got->add_global(gsym, GOT_TYPE_STANDARD); |
| else |
| { |
| // If this symbol is not fully resolved, we need to add a |
| // GOT entry with a dynamic relocation. |
| Reloc_section* rel_dyn = target->rel_dyn_section(layout); |
| if (gsym->is_from_dynobj() |
| || gsym->is_undefined() |
| || gsym->is_preemptible()) |
| got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, |
| rel_dyn, elfcpp::R_ARM_GLOB_DAT); |
| else |
| { |
| if (got->add_global(gsym, GOT_TYPE_STANDARD)) |
| rel_dyn->add_global_relative( |
| gsym, elfcpp::R_ARM_RELATIVE, got, |
| gsym->got_offset(GOT_TYPE_STANDARD)); |
| } |
| } |
| } |
| break; |
| |
| case elfcpp::R_ARM_TARGET1: |
| // This should have been mapped to another type already. |
| // Fall through. |
| case elfcpp::R_ARM_COPY: |
| case elfcpp::R_ARM_GLOB_DAT: |
| case elfcpp::R_ARM_JUMP_SLOT: |
| case elfcpp::R_ARM_RELATIVE: |
| // These are relocations which should only be seen by the |
| // dynamic linker, and should never be seen here. |
| gold_error(_("%s: unexpected reloc %u in object file"), |
| object->name().c_str(), r_type); |
| break; |
| |
| default: |
| unsupported_reloc_global(object, r_type, gsym); |
| break; |
| } |
| } |
| |
| // Process relocations for gc. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::gc_process_relocs(Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| unsigned int, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| size_t local_symbol_count, |
| const unsigned char* plocal_symbols) |
| { |
| typedef Target_arm<big_endian> Arm; |
| typedef typename Target_arm<big_endian>::Scan Scan; |
| |
| gold::gc_process_relocs<32, big_endian, Arm, elfcpp::SHT_REL, Scan>( |
| symtab, |
| layout, |
| this, |
| object, |
| data_shndx, |
| prelocs, |
| reloc_count, |
| output_section, |
| needs_special_offset_handling, |
| local_symbol_count, |
| plocal_symbols); |
| } |
| |
| // Scan relocations for a section. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::scan_relocs(Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| size_t local_symbol_count, |
| const unsigned char* plocal_symbols) |
| { |
| typedef typename Target_arm<big_endian>::Scan Scan; |
| if (sh_type == elfcpp::SHT_RELA) |
| { |
| gold_error(_("%s: unsupported RELA reloc section"), |
| object->name().c_str()); |
| return; |
| } |
| |
| gold::scan_relocs<32, big_endian, Target_arm, elfcpp::SHT_REL, Scan>( |
| symtab, |
| layout, |
| this, |
| object, |
| data_shndx, |
| prelocs, |
| reloc_count, |
| output_section, |
| needs_special_offset_handling, |
| local_symbol_count, |
| plocal_symbols); |
| } |
| |
| // Finalize the sections. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::do_finalize_sections( |
| Layout* layout, |
| const Input_objects* input_objects, |
| Symbol_table* symtab) |
| { |
| // Merge processor-specific flags. |
| for (Input_objects::Relobj_iterator p = input_objects->relobj_begin(); |
| p != input_objects->relobj_end(); |
| ++p) |
| { |
| Arm_relobj<big_endian>* arm_relobj = |
| Arm_relobj<big_endian>::as_arm_relobj(*p); |
| this->merge_processor_specific_flags( |
| arm_relobj->name(), |
| arm_relobj->processor_specific_flags()); |
| this->merge_object_attributes(arm_relobj->name().c_str(), |
| arm_relobj->attributes_section_data()); |
| |
| } |
| |
| for (Input_objects::Dynobj_iterator p = input_objects->dynobj_begin(); |
| p != input_objects->dynobj_end(); |
| ++p) |
| { |
| Arm_dynobj<big_endian>* arm_dynobj = |
| Arm_dynobj<big_endian>::as_arm_dynobj(*p); |
| this->merge_processor_specific_flags( |
| arm_dynobj->name(), |
| arm_dynobj->processor_specific_flags()); |
| this->merge_object_attributes(arm_dynobj->name().c_str(), |
| arm_dynobj->attributes_section_data()); |
| } |
| |
| // Check BLX use. |
| Object_attribute* attr = |
| this->get_aeabi_object_attribute(elfcpp::Tag_CPU_arch); |
| if (attr->int_value() > elfcpp::TAG_CPU_ARCH_V4) |
| this->set_may_use_blx(true); |
| |
| // Fill in some more dynamic tags. |
| Output_data_dynamic* const odyn = layout->dynamic_data(); |
| if (odyn != NULL) |
| { |
| if (this->got_plt_ != NULL |
| && this->got_plt_->output_section() != NULL) |
| odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); |
| |
| if (this->plt_ != NULL |
| && this->plt_->output_section() != NULL) |
| { |
| const Output_data* od = this->plt_->rel_plt(); |
| odyn->add_section_size(elfcpp::DT_PLTRELSZ, od); |
| odyn->add_section_address(elfcpp::DT_JMPREL, od); |
| odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL); |
| } |
| |
| if (this->rel_dyn_ != NULL |
| && this->rel_dyn_->output_section() != NULL) |
| { |
| const Output_data* od = this->rel_dyn_; |
| odyn->add_section_address(elfcpp::DT_REL, od); |
| odyn->add_section_size(elfcpp::DT_RELSZ, od); |
| odyn->add_constant(elfcpp::DT_RELENT, |
| elfcpp::Elf_sizes<32>::rel_size); |
| } |
| |
| if (!parameters->options().shared()) |
| { |
| // The value of the DT_DEBUG tag is filled in by the dynamic |
| // linker at run time, and used by the debugger. |
| odyn->add_constant(elfcpp::DT_DEBUG, 0); |
| } |
| } |
| |
| // Emit any relocs we saved in an attempt to avoid generating COPY |
| // relocs. |
| if (this->copy_relocs_.any_saved_relocs()) |
| this->copy_relocs_.emit(this->rel_dyn_section(layout)); |
| |
| // Handle the .ARM.exidx section. |
| Output_section* exidx_section = layout->find_output_section(".ARM.exidx"); |
| if (exidx_section != NULL |
| && exidx_section->type() == elfcpp::SHT_ARM_EXIDX |
| && !parameters->options().relocatable()) |
| { |
| // Create __exidx_start and __exdix_end symbols. |
| symtab->define_in_output_data("__exidx_start", NULL, exidx_section, |
| 0, 0, elfcpp::STT_OBJECT, |
| elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0, |
| false, false); |
| symtab->define_in_output_data("__exidx_end", NULL, exidx_section, |
| 0, 0, elfcpp::STT_OBJECT, |
| elfcpp::STB_GLOBAL, elfcpp::STV_HIDDEN, 0, |
| true, false); |
| |
| // For the ARM target, we need to add a PT_ARM_EXIDX segment for |
| // the .ARM.exidx section. |
| if (!layout->script_options()->saw_phdrs_clause()) |
| { |
| gold_assert(layout->find_output_segment(elfcpp::PT_ARM_EXIDX, 0, 0) |
| == NULL); |
| Output_segment* exidx_segment = |
| layout->make_output_segment(elfcpp::PT_ARM_EXIDX, elfcpp::PF_R); |
| exidx_segment->add_output_section(exidx_section, elfcpp::PF_R, |
| false); |
| } |
| } |
| |
| // Create an .ARM.attributes section if there is not one already. |
| Output_attributes_section_data* attributes_section = |
| new Output_attributes_section_data(*this->attributes_section_data_); |
| layout->add_output_section_data(".ARM.attributes", |
| elfcpp::SHT_ARM_ATTRIBUTES, 0, |
| attributes_section, false); |
| } |
| |
| // Return whether a direct absolute static relocation needs to be applied. |
| // In cases where Scan::local() or Scan::global() has created |
| // a dynamic relocation other than R_ARM_RELATIVE, the addend |
| // of the relocation is carried in the data, and we must not |
| // apply the static relocation. |
| |
| template<bool big_endian> |
| inline bool |
| Target_arm<big_endian>::Relocate::should_apply_static_reloc( |
| const Sized_symbol<32>* gsym, |
| int ref_flags, |
| bool is_32bit, |
| Output_section* output_section) |
| { |
| // If the output section is not allocated, then we didn't call |
| // scan_relocs, we didn't create a dynamic reloc, and we must apply |
| // the reloc here. |
| if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0) |
| return true; |
| |
| // For local symbols, we will have created a non-RELATIVE dynamic |
| // relocation only if (a) the output is position independent, |
| // (b) the relocation is absolute (not pc- or segment-relative), and |
| // (c) the relocation is not 32 bits wide. |
| if (gsym == NULL) |
| return !(parameters->options().output_is_position_independent() |
| && (ref_flags & Symbol::ABSOLUTE_REF) |
| && !is_32bit); |
| |
| // For global symbols, we use the same helper routines used in the |
| // scan pass. If we did not create a dynamic relocation, or if we |
| // created a RELATIVE dynamic relocation, we should apply the static |
| // relocation. |
| bool has_dyn = gsym->needs_dynamic_reloc(ref_flags); |
| bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF) |
| && gsym->can_use_relative_reloc(ref_flags |
| & Symbol::FUNCTION_CALL); |
| return !has_dyn || is_rel; |
| } |
| |
| // Perform a relocation. |
| |
| template<bool big_endian> |
| inline bool |
| Target_arm<big_endian>::Relocate::relocate( |
| const Relocate_info<32, big_endian>* relinfo, |
| Target_arm* target, |
| Output_section *output_section, |
| size_t relnum, |
| const elfcpp::Rel<32, big_endian>& rel, |
| unsigned int r_type, |
| const Sized_symbol<32>* gsym, |
| const Symbol_value<32>* psymval, |
| unsigned char* view, |
| Arm_address address, |
| section_size_type /* view_size */ ) |
| { |
| typedef Arm_relocate_functions<big_endian> Arm_relocate_functions; |
| |
| r_type = get_real_reloc_type(r_type); |
| |
| const Arm_relobj<big_endian>* object = |
| Arm_relobj<big_endian>::as_arm_relobj(relinfo->object); |
| |
| // If the final branch target of a relocation is THUMB instruction, this |
| // is 1. Otherwise it is 0. |
| Arm_address thumb_bit = 0; |
| Symbol_value<32> symval; |
| bool is_weakly_undefined_without_plt = false; |
| if (relnum != Target_arm<big_endian>::fake_relnum_for_stubs) |
| { |
| if (gsym != NULL) |
| { |
| // This is a global symbol. Determine if we use PLT and if the |
| // final target is THUMB. |
| if (gsym->use_plt_offset(reloc_is_non_pic(r_type))) |
| { |
| // This uses a PLT, change the symbol value. |
| symval.set_output_value(target->plt_section()->address() |
| + gsym->plt_offset()); |
| psymval = &symval; |
| } |
| else if (gsym->is_weak_undefined()) |
| { |
| // This is a weakly undefined symbol and we do not use PLT |
| // for this relocation. A branch targeting this symbol will |
| // be converted into an NOP. |
| is_weakly_undefined_without_plt = true; |
| } |
| else |
| { |
| // Set thumb bit if symbol: |
| // -Has type STT_ARM_TFUNC or |
| // -Has type STT_FUNC, is defined and with LSB in value set. |
| thumb_bit = |
| (((gsym->type() == elfcpp::STT_ARM_TFUNC) |
| || (gsym->type() == elfcpp::STT_FUNC |
| && !gsym->is_undefined() |
| && ((psymval->value(object, 0) & 1) != 0))) |
| ? 1 |
| : 0); |
| } |
| } |
| else |
| { |
| // This is a local symbol. Determine if the final target is THUMB. |
| // We saved this information when all the local symbols were read. |
| elfcpp::Elf_types<32>::Elf_WXword r_info = rel.get_r_info(); |
| unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info); |
| thumb_bit = object->local_symbol_is_thumb_function(r_sym) ? 1 : 0; |
| } |
| } |
| else |
| { |
| // This is a fake relocation synthesized for a stub. It does not have |
| // a real symbol. We just look at the LSB of the symbol value to |
| // determine if the target is THUMB or not. |
| thumb_bit = ((psymval->value(object, 0) & 1) != 0); |
| } |
| |
| // Strip LSB if this points to a THUMB target. |
| if (thumb_bit != 0 |
| && Target_arm<big_endian>::reloc_uses_thumb_bit(r_type) |
| && ((psymval->value(object, 0) & 1) != 0)) |
| { |
| Arm_address stripped_value = |
| psymval->value(object, 0) & ~static_cast<Arm_address>(1); |
| symval.set_output_value(stripped_value); |
| psymval = &symval; |
| } |
| |
| // Get the GOT offset if needed. |
| // The GOT pointer points to the end of the GOT section. |
| // We need to subtract the size of the GOT section to get |
| // the actual offset to use in the relocation. |
| bool have_got_offset = false; |
| unsigned int got_offset = 0; |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_GOT_BREL: |
| case elfcpp::R_ARM_GOT_PREL: |
| if (gsym != NULL) |
| { |
| gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD)); |
| got_offset = (gsym->got_offset(GOT_TYPE_STANDARD) |
| - target->got_size()); |
| } |
| else |
| { |
| unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD)); |
| got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD) |
| - target->got_size()); |
| } |
| have_got_offset = true; |
| break; |
| |
| default: |
| break; |
| } |
| |
| // To look up relocation stubs, we need to pass the symbol table index of |
| // a local symbol. |
| unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info()); |
| |
| typename Arm_relocate_functions::Status reloc_status = |
| Arm_relocate_functions::STATUS_OKAY; |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_NONE: |
| break; |
| |
| case elfcpp::R_ARM_ABS8: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, |
| output_section)) |
| reloc_status = Arm_relocate_functions::abs8(view, object, psymval); |
| break; |
| |
| case elfcpp::R_ARM_ABS12: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, |
| output_section)) |
| reloc_status = Arm_relocate_functions::abs12(view, object, psymval); |
| break; |
| |
| case elfcpp::R_ARM_ABS16: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, |
| output_section)) |
| reloc_status = Arm_relocate_functions::abs16(view, object, psymval); |
| break; |
| |
| case elfcpp::R_ARM_ABS32: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, |
| output_section)) |
| reloc_status = Arm_relocate_functions::abs32(view, object, psymval, |
| thumb_bit); |
| break; |
| |
| case elfcpp::R_ARM_ABS32_NOI: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, |
| output_section)) |
| // No thumb bit for this relocation: (S + A) |
| reloc_status = Arm_relocate_functions::abs32(view, object, psymval, |
| 0); |
| break; |
| |
| case elfcpp::R_ARM_MOVW_ABS_NC: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, |
| output_section)) |
| reloc_status = Arm_relocate_functions::movw_abs_nc(view, object, |
| psymval, |
| thumb_bit); |
| else |
| gold_error(_("relocation R_ARM_MOVW_ABS_NC cannot be used when making" |
| "a shared object; recompile with -fPIC")); |
| break; |
| |
| case elfcpp::R_ARM_MOVT_ABS: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, |
| output_section)) |
| reloc_status = Arm_relocate_functions::movt_abs(view, object, psymval); |
| else |
| gold_error(_("relocation R_ARM_MOVT_ABS cannot be used when making" |
| "a shared object; recompile with -fPIC")); |
| break; |
| |
| case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, |
| output_section)) |
| reloc_status = Arm_relocate_functions::thm_movw_abs_nc(view, object, |
| psymval, |
| thumb_bit); |
| else |
| gold_error(_("relocation R_ARM_THM_MOVW_ABS_NC cannot be used when" |
| "making a shared object; recompile with -fPIC")); |
| break; |
| |
| case elfcpp::R_ARM_THM_MOVT_ABS: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, |
| output_section)) |
| reloc_status = Arm_relocate_functions::thm_movt_abs(view, object, |
| psymval); |
| else |
| gold_error(_("relocation R_ARM_THM_MOVT_ABS cannot be used when" |
| "making a shared object; recompile with -fPIC")); |
| break; |
| |
| case elfcpp::R_ARM_MOVW_PREL_NC: |
| reloc_status = Arm_relocate_functions::movw_prel_nc(view, object, |
| psymval, address, |
| thumb_bit); |
| break; |
| |
| case elfcpp::R_ARM_MOVT_PREL: |
| reloc_status = Arm_relocate_functions::movt_prel(view, object, |
| psymval, address); |
| break; |
| |
| case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
| reloc_status = Arm_relocate_functions::thm_movw_prel_nc(view, object, |
| psymval, address, |
| thumb_bit); |
| break; |
| |
| case elfcpp::R_ARM_THM_MOVT_PREL: |
| reloc_status = Arm_relocate_functions::thm_movt_prel(view, object, |
| psymval, address); |
| break; |
| |
| case elfcpp::R_ARM_REL32: |
| reloc_status = Arm_relocate_functions::rel32(view, object, psymval, |
| address, thumb_bit); |
| break; |
| |
| case elfcpp::R_ARM_THM_ABS5: |
| if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false, |
| output_section)) |
| reloc_status = Arm_relocate_functions::thm_abs5(view, object, psymval); |
| break; |
| |
| case elfcpp::R_ARM_THM_CALL: |
| reloc_status = |
| Arm_relocate_functions::thm_call(relinfo, view, gsym, object, r_sym, |
| psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| break; |
| |
| case elfcpp::R_ARM_XPC25: |
| reloc_status = |
| Arm_relocate_functions::xpc25(relinfo, view, gsym, object, r_sym, |
| psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| break; |
| |
| case elfcpp::R_ARM_THM_XPC22: |
| reloc_status = |
| Arm_relocate_functions::thm_xpc22(relinfo, view, gsym, object, r_sym, |
| psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| break; |
| |
| case elfcpp::R_ARM_GOTOFF32: |
| { |
| Arm_address got_origin; |
| got_origin = target->got_plt_section()->address(); |
| reloc_status = Arm_relocate_functions::rel32(view, object, psymval, |
| got_origin, thumb_bit); |
| } |
| break; |
| |
| case elfcpp::R_ARM_BASE_PREL: |
| { |
| uint32_t origin; |
| // Get the addressing origin of the output segment defining the |
| // symbol gsym (AAELF 4.6.1.2 Relocation types) |
| gold_assert(gsym != NULL); |
| if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT) |
| origin = gsym->output_segment()->vaddr(); |
| else if (gsym->source () == Symbol::IN_OUTPUT_DATA) |
| origin = gsym->output_data()->address(); |
| else |
| { |
| gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| _("cannot find origin of R_ARM_BASE_PREL")); |
| return true; |
| } |
| reloc_status = Arm_relocate_functions::base_prel(view, origin, address); |
| } |
| break; |
| |
| case elfcpp::R_ARM_BASE_ABS: |
| { |
| if (!should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true, |
| output_section)) |
| break; |
| |
| uint32_t origin; |
| // Get the addressing origin of the output segment defining |
| // the symbol gsym (AAELF 4.6.1.2 Relocation types). |
| if (gsym == NULL) |
| // R_ARM_BASE_ABS with the NULL symbol will give the |
| // absolute address of the GOT origin (GOT_ORG) (see ARM IHI |
| // 0044C (AAELF): 4.6.1.8 Proxy generating relocations). |
| origin = target->got_plt_section()->address(); |
| else if (gsym->source() == Symbol::IN_OUTPUT_SEGMENT) |
| origin = gsym->output_segment()->vaddr(); |
| else if (gsym->source () == Symbol::IN_OUTPUT_DATA) |
| origin = gsym->output_data()->address(); |
| else |
| { |
| gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| _("cannot find origin of R_ARM_BASE_ABS")); |
| return true; |
| } |
| |
| reloc_status = Arm_relocate_functions::base_abs(view, origin); |
| } |
| break; |
| |
| case elfcpp::R_ARM_GOT_BREL: |
| gold_assert(have_got_offset); |
| reloc_status = Arm_relocate_functions::got_brel(view, got_offset); |
| break; |
| |
| case elfcpp::R_ARM_GOT_PREL: |
| gold_assert(have_got_offset); |
| // Get the address origin for GOT PLT, which is allocated right |
| // after the GOT section, to calculate an absolute address of |
| // the symbol GOT entry (got_origin + got_offset). |
| Arm_address got_origin; |
| got_origin = target->got_plt_section()->address(); |
| reloc_status = Arm_relocate_functions::got_prel(view, |
| got_origin + got_offset, |
| address); |
| break; |
| |
| case elfcpp::R_ARM_PLT32: |
| gold_assert(gsym == NULL |
| || gsym->has_plt_offset() |
| || gsym->final_value_is_known() |
| || (gsym->is_defined() |
| && !gsym->is_from_dynobj() |
| && !gsym->is_preemptible())); |
| reloc_status = |
| Arm_relocate_functions::plt32(relinfo, view, gsym, object, r_sym, |
| psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| break; |
| |
| case elfcpp::R_ARM_CALL: |
| reloc_status = |
| Arm_relocate_functions::call(relinfo, view, gsym, object, r_sym, |
| psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| break; |
| |
| case elfcpp::R_ARM_JUMP24: |
| reloc_status = |
| Arm_relocate_functions::jump24(relinfo, view, gsym, object, r_sym, |
| psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| break; |
| |
| case elfcpp::R_ARM_THM_JUMP24: |
| reloc_status = |
| Arm_relocate_functions::thm_jump24(relinfo, view, gsym, object, r_sym, |
| psymval, address, thumb_bit, |
| is_weakly_undefined_without_plt); |
| break; |
| |
| case elfcpp::R_ARM_PREL31: |
| reloc_status = Arm_relocate_functions::prel31(view, object, psymval, |
| address, thumb_bit); |
| break; |
| |
| case elfcpp::R_ARM_TARGET1: |
| // This should have been mapped to another type already. |
| // Fall through. |
| case elfcpp::R_ARM_COPY: |
| case elfcpp::R_ARM_GLOB_DAT: |
| case elfcpp::R_ARM_JUMP_SLOT: |
| case elfcpp::R_ARM_RELATIVE: |
| // These are relocations which should only be seen by the |
| // dynamic linker, and should never be seen here. |
| gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| _("unexpected reloc %u in object file"), |
| r_type); |
| break; |
| |
| default: |
| gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| _("unsupported reloc %u"), |
| r_type); |
| break; |
| } |
| |
| // Report any errors. |
| switch (reloc_status) |
| { |
| case Arm_relocate_functions::STATUS_OKAY: |
| break; |
| case Arm_relocate_functions::STATUS_OVERFLOW: |
| gold_error_at_location(relinfo, relnum, rel.get_r_offset(), |
| _("relocation overflow in relocation %u"), |
| r_type); |
| break; |
| case Arm_relocate_functions::STATUS_BAD_RELOC: |
| gold_error_at_location( |
| relinfo, |
| relnum, |
| rel.get_r_offset(), |
| _("unexpected opcode while processing relocation %u"), |
| r_type); |
| break; |
| default: |
| gold_unreachable(); |
| } |
| |
| return true; |
| } |
| |
| // Relocate section data. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::relocate_section( |
| const Relocate_info<32, big_endian>* relinfo, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| unsigned char* view, |
| Arm_address address, |
| section_size_type view_size, |
| const Reloc_symbol_changes* reloc_symbol_changes) |
| { |
| typedef typename Target_arm<big_endian>::Relocate Arm_relocate; |
| gold_assert(sh_type == elfcpp::SHT_REL); |
| |
| Arm_input_section<big_endian>* arm_input_section = |
| this->find_arm_input_section(relinfo->object, relinfo->data_shndx); |
| |
| // This is an ARM input section and the view covers the whole output |
| // section. |
| if (arm_input_section != NULL) |
| { |
| gold_assert(needs_special_offset_handling); |
| Arm_address section_address = arm_input_section->address(); |
| section_size_type section_size = arm_input_section->data_size(); |
| |
| gold_assert((arm_input_section->address() >= address) |
| && ((arm_input_section->address() |
| + arm_input_section->data_size()) |
| <= (address + view_size))); |
| |
| off_t offset = section_address - address; |
| view += offset; |
| address += offset; |
| view_size = section_size; |
| } |
| |
| gold::relocate_section<32, big_endian, Target_arm, elfcpp::SHT_REL, |
| Arm_relocate>( |
| relinfo, |
| this, |
| prelocs, |
| reloc_count, |
| output_section, |
| needs_special_offset_handling, |
| view, |
| address, |
| view_size, |
| reloc_symbol_changes); |
| } |
| |
| // Return the size of a relocation while scanning during a relocatable |
| // link. |
| |
| template<bool big_endian> |
| unsigned int |
| Target_arm<big_endian>::Relocatable_size_for_reloc::get_size_for_reloc( |
| unsigned int r_type, |
| Relobj* object) |
| { |
| r_type = get_real_reloc_type(r_type); |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_NONE: |
| return 0; |
| |
| case elfcpp::R_ARM_ABS8: |
| return 1; |
| |
| case elfcpp::R_ARM_ABS16: |
| case elfcpp::R_ARM_THM_ABS5: |
| return 2; |
| |
| case elfcpp::R_ARM_ABS32: |
| case elfcpp::R_ARM_ABS32_NOI: |
| case elfcpp::R_ARM_ABS12: |
| case elfcpp::R_ARM_BASE_ABS: |
| case elfcpp::R_ARM_REL32: |
| case elfcpp::R_ARM_THM_CALL: |
| case elfcpp::R_ARM_GOTOFF32: |
| case elfcpp::R_ARM_BASE_PREL: |
| case elfcpp::R_ARM_GOT_BREL: |
| case elfcpp::R_ARM_GOT_PREL: |
| case elfcpp::R_ARM_PLT32: |
| case elfcpp::R_ARM_CALL: |
| case elfcpp::R_ARM_JUMP24: |
| case elfcpp::R_ARM_PREL31: |
| case elfcpp::R_ARM_MOVW_ABS_NC: |
| case elfcpp::R_ARM_MOVT_ABS: |
| case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
| case elfcpp::R_ARM_THM_MOVT_ABS: |
| case elfcpp::R_ARM_MOVW_PREL_NC: |
| case elfcpp::R_ARM_MOVT_PREL: |
| case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
| case elfcpp::R_ARM_THM_MOVT_PREL: |
| return 4; |
| |
| case elfcpp::R_ARM_TARGET1: |
| // This should have been mapped to another type already. |
| // Fall through. |
| case elfcpp::R_ARM_COPY: |
| case elfcpp::R_ARM_GLOB_DAT: |
| case elfcpp::R_ARM_JUMP_SLOT: |
| case elfcpp::R_ARM_RELATIVE: |
| // These are relocations which should only be seen by the |
| // dynamic linker, and should never be seen here. |
| gold_error(_("%s: unexpected reloc %u in object file"), |
| object->name().c_str(), r_type); |
| return 0; |
| |
| default: |
| object->error(_("unsupported reloc %u in object file"), r_type); |
| return 0; |
| } |
| } |
| |
| // Scan the relocs during a relocatable link. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::scan_relocatable_relocs( |
| Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, big_endian>* object, |
| unsigned int data_shndx, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| size_t local_symbol_count, |
| const unsigned char* plocal_symbols, |
| Relocatable_relocs* rr) |
| { |
| gold_assert(sh_type == elfcpp::SHT_REL); |
| |
| typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL, |
| Relocatable_size_for_reloc> Scan_relocatable_relocs; |
| |
| gold::scan_relocatable_relocs<32, big_endian, elfcpp::SHT_REL, |
| Scan_relocatable_relocs>( |
| symtab, |
| layout, |
| object, |
| data_shndx, |
| prelocs, |
| reloc_count, |
| output_section, |
| needs_special_offset_handling, |
| local_symbol_count, |
| plocal_symbols, |
| rr); |
| } |
| |
| // Relocate a section during a relocatable link. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::relocate_for_relocatable( |
| const Relocate_info<32, big_endian>* relinfo, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| off_t offset_in_output_section, |
| const Relocatable_relocs* rr, |
| unsigned char* view, |
| Arm_address view_address, |
| section_size_type view_size, |
| unsigned char* reloc_view, |
| section_size_type reloc_view_size) |
| { |
| gold_assert(sh_type == elfcpp::SHT_REL); |
| |
| gold::relocate_for_relocatable<32, big_endian, elfcpp::SHT_REL>( |
| relinfo, |
| prelocs, |
| reloc_count, |
| output_section, |
| offset_in_output_section, |
| rr, |
| view, |
| view_address, |
| view_size, |
| reloc_view, |
| reloc_view_size); |
| } |
| |
| // Return the value to use for a dynamic symbol which requires special |
| // treatment. This is how we support equality comparisons of function |
| // pointers across shared library boundaries, as described in the |
| // processor specific ABI supplement. |
| |
| template<bool big_endian> |
| uint64_t |
| Target_arm<big_endian>::do_dynsym_value(const Symbol* gsym) const |
| { |
| gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset()); |
| return this->plt_section()->address() + gsym->plt_offset(); |
| } |
| |
| // Map platform-specific relocs to real relocs |
| // |
| template<bool big_endian> |
| unsigned int |
| Target_arm<big_endian>::get_real_reloc_type (unsigned int r_type) |
| { |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_TARGET1: |
| // This is either R_ARM_ABS32 or R_ARM_REL32; |
| return elfcpp::R_ARM_ABS32; |
| |
| case elfcpp::R_ARM_TARGET2: |
| // This can be any reloc type but ususally is R_ARM_GOT_PREL |
| return elfcpp::R_ARM_GOT_PREL; |
| |
| default: |
| return r_type; |
| } |
| } |
| |
| // Whether if two EABI versions V1 and V2 are compatible. |
| |
| template<bool big_endian> |
| bool |
| Target_arm<big_endian>::are_eabi_versions_compatible( |
| elfcpp::Elf_Word v1, |
| elfcpp::Elf_Word v2) |
| { |
| // v4 and v5 are the same spec before and after it was released, |
| // so allow mixing them. |
| if ((v1 == elfcpp::EF_ARM_EABI_VER4 && v2 == elfcpp::EF_ARM_EABI_VER5) |
| || (v1 == elfcpp::EF_ARM_EABI_VER5 && v2 == elfcpp::EF_ARM_EABI_VER4)) |
| return true; |
| |
| return v1 == v2; |
| } |
| |
| // Combine FLAGS from an input object called NAME and the processor-specific |
| // flags in the ELF header of the output. Much of this is adapted from the |
| // processor-specific flags merging code in elf32_arm_merge_private_bfd_data |
| // in bfd/elf32-arm.c. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::merge_processor_specific_flags( |
| const std::string& name, |
| elfcpp::Elf_Word flags) |
| { |
| if (this->are_processor_specific_flags_set()) |
| { |
| elfcpp::Elf_Word out_flags = this->processor_specific_flags(); |
| |
| // Nothing to merge if flags equal to those in output. |
| if (flags == out_flags) |
| return; |
| |
| // Complain about various flag mismatches. |
| elfcpp::Elf_Word version1 = elfcpp::arm_eabi_version(flags); |
| elfcpp::Elf_Word version2 = elfcpp::arm_eabi_version(out_flags); |
| if (!this->are_eabi_versions_compatible(version1, version2)) |
| gold_error(_("Source object %s has EABI version %d but output has " |
| "EABI version %d."), |
| name.c_str(), |
| (flags & elfcpp::EF_ARM_EABIMASK) >> 24, |
| (out_flags & elfcpp::EF_ARM_EABIMASK) >> 24); |
| } |
| else |
| { |
| // If the input is the default architecture and had the default |
| // flags then do not bother setting the flags for the output |
| // architecture, instead allow future merges to do this. If no |
| // future merges ever set these flags then they will retain their |
| // uninitialised values, which surprise surprise, correspond |
| // to the default values. |
| if (flags == 0) |
| return; |
| |
| // This is the first time, just copy the flags. |
| // We only copy the EABI version for now. |
| this->set_processor_specific_flags(flags & elfcpp::EF_ARM_EABIMASK); |
| } |
| } |
| |
| // Adjust ELF file header. |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::do_adjust_elf_header( |
| unsigned char* view, |
| int len) const |
| { |
| gold_assert(len == elfcpp::Elf_sizes<32>::ehdr_size); |
| |
| elfcpp::Ehdr<32, big_endian> ehdr(view); |
| unsigned char e_ident[elfcpp::EI_NIDENT]; |
| memcpy(e_ident, ehdr.get_e_ident(), elfcpp::EI_NIDENT); |
| |
| if (elfcpp::arm_eabi_version(this->processor_specific_flags()) |
| == elfcpp::EF_ARM_EABI_UNKNOWN) |
| e_ident[elfcpp::EI_OSABI] = elfcpp::ELFOSABI_ARM; |
| else |
| e_ident[elfcpp::EI_OSABI] = 0; |
| e_ident[elfcpp::EI_ABIVERSION] = 0; |
| |
| // FIXME: Do EF_ARM_BE8 adjustment. |
| |
| elfcpp::Ehdr_write<32, big_endian> oehdr(view); |
| oehdr.put_e_ident(e_ident); |
| } |
| |
| // do_make_elf_object to override the same function in the base class. |
| // We need to use a target-specific sub-class of Sized_relobj<32, big_endian> |
| // to store ARM specific information. Hence we need to have our own |
| // ELF object creation. |
| |
| template<bool big_endian> |
| Object* |
| Target_arm<big_endian>::do_make_elf_object( |
| const std::string& name, |
| Input_file* input_file, |
| off_t offset, const elfcpp::Ehdr<32, big_endian>& ehdr) |
| { |
| int et = ehdr.get_e_type(); |
| if (et == elfcpp::ET_REL) |
| { |
| Arm_relobj<big_endian>* obj = |
| new Arm_relobj<big_endian>(name, input_file, offset, ehdr); |
| obj->setup(); |
| return obj; |
| } |
| else if (et == elfcpp::ET_DYN) |
| { |
| Sized_dynobj<32, big_endian>* obj = |
| new Arm_dynobj<big_endian>(name, input_file, offset, ehdr); |
| obj->setup(); |
| return obj; |
| } |
| else |
| { |
| gold_error(_("%s: unsupported ELF file type %d"), |
| name.c_str(), et); |
| return NULL; |
| } |
| } |
| |
| // Read the architecture from the Tag_also_compatible_with attribute, if any. |
| // Returns -1 if no architecture could be read. |
| // This is adapted from get_secondary_compatible_arch() in bfd/elf32-arm.c. |
| |
| template<bool big_endian> |
| int |
| Target_arm<big_endian>::get_secondary_compatible_arch( |
| const Attributes_section_data* pasd) |
| { |
| const Object_attribute *known_attributes = |
| pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC); |
| |
| // Note: the tag and its argument below are uleb128 values, though |
| // currently-defined values fit in one byte for each. |
| const std::string& sv = |
| known_attributes[elfcpp::Tag_also_compatible_with].string_value(); |
| if (sv.size() == 2 |
| && sv.data()[0] == elfcpp::Tag_CPU_arch |
| && (sv.data()[1] & 128) != 128) |
| return sv.data()[1]; |
| |
| // This tag is "safely ignorable", so don't complain if it looks funny. |
| return -1; |
| } |
| |
| // Set, or unset, the architecture of the Tag_also_compatible_with attribute. |
| // The tag is removed if ARCH is -1. |
| // This is adapted from set_secondary_compatible_arch() in bfd/elf32-arm.c. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::set_secondary_compatible_arch( |
| Attributes_section_data* pasd, |
| int arch) |
| { |
| Object_attribute *known_attributes = |
| pasd->known_attributes(Object_attribute::OBJ_ATTR_PROC); |
| |
| if (arch == -1) |
| { |
| known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(""); |
| return; |
| } |
| |
| // Note: the tag and its argument below are uleb128 values, though |
| // currently-defined values fit in one byte for each. |
| char sv[3]; |
| sv[0] = elfcpp::Tag_CPU_arch; |
| gold_assert(arch != 0); |
| sv[1] = arch; |
| sv[2] = '\0'; |
| |
| known_attributes[elfcpp::Tag_also_compatible_with].set_string_value(sv); |
| } |
| |
| // Combine two values for Tag_CPU_arch, taking secondary compatibility tags |
| // into account. |
| // This is adapted from tag_cpu_arch_combine() in bfd/elf32-arm.c. |
| |
| template<bool big_endian> |
| int |
| Target_arm<big_endian>::tag_cpu_arch_combine( |
| const char* name, |
| int oldtag, |
| int* secondary_compat_out, |
| int newtag, |
| int secondary_compat) |
| { |
| #define T(X) elfcpp::TAG_CPU_ARCH_##X |
| static const int v6t2[] = |
| { |
| T(V6T2), // PRE_V4. |
| T(V6T2), // V4. |
| T(V6T2), // V4T. |
| T(V6T2), // V5T. |
| T(V6T2), // V5TE. |
| T(V6T2), // V5TEJ. |
| T(V6T2), // V6. |
| T(V7), // V6KZ. |
| T(V6T2) // V6T2. |
| }; |
| static const int v6k[] = |
| { |
| T(V6K), // PRE_V4. |
| T(V6K), // V4. |
| T(V6K), // V4T. |
| T(V6K), // V5T. |
| T(V6K), // V5TE. |
| T(V6K), // V5TEJ. |
| T(V6K), // V6. |
| T(V6KZ), // V6KZ. |
| T(V7), // V6T2. |
| T(V6K) // V6K. |
| }; |
| static const int v7[] = |
| { |
| T(V7), // PRE_V4. |
| T(V7), // V4. |
| T(V7), // V4T. |
| T(V7), // V5T. |
| T(V7), // V5TE. |
| T(V7), // V5TEJ. |
| T(V7), // V6. |
| T(V7), // V6KZ. |
| T(V7), // V6T2. |
| T(V7), // V6K. |
| T(V7) // V7. |
| }; |
| static const int v6_m[] = |
| { |
| -1, // PRE_V4. |
| -1, // V4. |
| T(V6K), // V4T. |
| T(V6K), // V5T. |
| T(V6K), // V5TE. |
| T(V6K), // V5TEJ. |
| T(V6K), // V6. |
| T(V6KZ), // V6KZ. |
| T(V7), // V6T2. |
| T(V6K), // V6K. |
| T(V7), // V7. |
| T(V6_M) // V6_M. |
| }; |
| static const int v6s_m[] = |
| { |
| -1, // PRE_V4. |
| -1, // V4. |
| T(V6K), // V4T. |
| T(V6K), // V5T. |
| T(V6K), // V5TE. |
| T(V6K), // V5TEJ. |
| T(V6K), // V6. |
| T(V6KZ), // V6KZ. |
| T(V7), // V6T2. |
| T(V6K), // V6K. |
| T(V7), // V7. |
| T(V6S_M), // V6_M. |
| T(V6S_M) // V6S_M. |
| }; |
| static const int v7e_m[] = |
| { |
| -1, // PRE_V4. |
| -1, // V4. |
| T(V7E_M), // V4T. |
| T(V7E_M), // V5T. |
| T(V7E_M), // V5TE. |
| T(V7E_M), // V5TEJ. |
| T(V7E_M), // V6. |
| T(V7E_M), // V6KZ. |
| T(V7E_M), // V6T2. |
| T(V7E_M), // V6K. |
| T(V7E_M), // V7. |
| T(V7E_M), // V6_M. |
| T(V7E_M), // V6S_M. |
| T(V7E_M) // V7E_M. |
| }; |
| static const int v4t_plus_v6_m[] = |
| { |
| -1, // PRE_V4. |
| -1, // V4. |
| T(V4T), // V4T. |
| T(V5T), // V5T. |
| T(V5TE), // V5TE. |
| T(V5TEJ), // V5TEJ. |
| T(V6), // V6. |
| T(V6KZ), // V6KZ. |
| T(V6T2), // V6T2. |
| T(V6K), // V6K. |
| T(V7), // V7. |
| T(V6_M), // V6_M. |
| T(V6S_M), // V6S_M. |
| T(V7E_M), // V7E_M. |
| T(V4T_PLUS_V6_M) // V4T plus V6_M. |
| }; |
| static const int *comb[] = |
| { |
| v6t2, |
| v6k, |
| v7, |
| v6_m, |
| v6s_m, |
| v7e_m, |
| // Pseudo-architecture. |
| v4t_plus_v6_m |
| }; |
| |
| // Check we've not got a higher architecture than we know about. |
| |
| if (oldtag >= elfcpp::MAX_TAG_CPU_ARCH || newtag >= elfcpp::MAX_TAG_CPU_ARCH) |
| { |
| gold_error(_("%s: unknown CPU architecture"), name); |
| return -1; |
| } |
| |
| // Override old tag if we have a Tag_also_compatible_with on the output. |
| |
| if ((oldtag == T(V6_M) && *secondary_compat_out == T(V4T)) |
| || (oldtag == T(V4T) && *secondary_compat_out == T(V6_M))) |
| oldtag = T(V4T_PLUS_V6_M); |
| |
| // And override the new tag if we have a Tag_also_compatible_with on the |
| // input. |
| |
| if ((newtag == T(V6_M) && secondary_compat == T(V4T)) |
| || (newtag == T(V4T) && secondary_compat == T(V6_M))) |
| newtag = T(V4T_PLUS_V6_M); |
| |
| // Architectures before V6KZ add features monotonically. |
| int tagh = std::max(oldtag, newtag); |
| if (tagh <= elfcpp::TAG_CPU_ARCH_V6KZ) |
| return tagh; |
| |
| int tagl = std::min(oldtag, newtag); |
| int result = comb[tagh - T(V6T2)][tagl]; |
| |
| // Use Tag_CPU_arch == V4T and Tag_also_compatible_with (Tag_CPU_arch V6_M) |
| // as the canonical version. |
| if (result == T(V4T_PLUS_V6_M)) |
| { |
| result = T(V4T); |
| *secondary_compat_out = T(V6_M); |
| } |
| else |
| *secondary_compat_out = -1; |
| |
| if (result == -1) |
| { |
| gold_error(_("%s: conflicting CPU architectures %d/%d"), |
| name, oldtag, newtag); |
| return -1; |
| } |
| |
| return result; |
| #undef T |
| } |
| |
| // Helper to print AEABI enum tag value. |
| |
| template<bool big_endian> |
| std::string |
| Target_arm<big_endian>::aeabi_enum_name(unsigned int value) |
| { |
| static const char *aeabi_enum_names[] = |
| { "", "variable-size", "32-bit", "" }; |
| const size_t aeabi_enum_names_size = |
| sizeof(aeabi_enum_names) / sizeof(aeabi_enum_names[0]); |
| |
| if (value < aeabi_enum_names_size) |
| return std::string(aeabi_enum_names[value]); |
| else |
| { |
| char buffer[100]; |
| sprintf(buffer, "<unknown value %u>", value); |
| return std::string(buffer); |
| } |
| } |
| |
| // Return the string value to store in TAG_CPU_name. |
| |
| template<bool big_endian> |
| std::string |
| Target_arm<big_endian>::tag_cpu_name_value(unsigned int value) |
| { |
| static const char *name_table[] = { |
| // These aren't real CPU names, but we can't guess |
| // that from the architecture version alone. |
| "Pre v4", |
| "ARM v4", |
| "ARM v4T", |
| "ARM v5T", |
| "ARM v5TE", |
| "ARM v5TEJ", |
| "ARM v6", |
| "ARM v6KZ", |
| "ARM v6T2", |
| "ARM v6K", |
| "ARM v7", |
| "ARM v6-M", |
| "ARM v6S-M", |
| "ARM v7E-M" |
| }; |
| const size_t name_table_size = sizeof(name_table) / sizeof(name_table[0]); |
| |
| if (value < name_table_size) |
| return std::string(name_table[value]); |
| else |
| { |
| char buffer[100]; |
| sprintf(buffer, "<unknown CPU value %u>", value); |
| return std::string(buffer); |
| } |
| } |
| |
| // Merge object attributes from input file called NAME with those of the |
| // output. The input object attributes are in the object pointed by PASD. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::merge_object_attributes( |
| const char* name, |
| const Attributes_section_data* pasd) |
| { |
| // Return if there is no attributes section data. |
| if (pasd == NULL) |
| return; |
| |
| // If output has no object attributes, just copy. |
| if (this->attributes_section_data_ == NULL) |
| { |
| this->attributes_section_data_ = new Attributes_section_data(*pasd); |
| return; |
| } |
| |
| const int vendor = Object_attribute::OBJ_ATTR_PROC; |
| const Object_attribute* in_attr = pasd->known_attributes(vendor); |
| Object_attribute* out_attr = |
| this->attributes_section_data_->known_attributes(vendor); |
| |
| // This needs to happen before Tag_ABI_FP_number_model is merged. */ |
| if (in_attr[elfcpp::Tag_ABI_VFP_args].int_value() |
| != out_attr[elfcpp::Tag_ABI_VFP_args].int_value()) |
| { |
| // Ignore mismatches if the object doesn't use floating point. */ |
| if (out_attr[elfcpp::Tag_ABI_FP_number_model].int_value() == 0) |
| out_attr[elfcpp::Tag_ABI_VFP_args].set_int_value( |
| in_attr[elfcpp::Tag_ABI_VFP_args].int_value()); |
| else if (in_attr[elfcpp::Tag_ABI_FP_number_model].int_value() != 0) |
| gold_error(_("%s uses VFP register arguments, output does not"), |
| name); |
| } |
| |
| for (int i = 4; i < Vendor_object_attributes::NUM_KNOWN_ATTRIBUTES; ++i) |
| { |
| // Merge this attribute with existing attributes. |
| switch (i) |
| { |
| case elfcpp::Tag_CPU_raw_name: |
| case elfcpp::Tag_CPU_name: |
| // These are merged after Tag_CPU_arch. |
| break; |
| |
| case elfcpp::Tag_ABI_optimization_goals: |
| case elfcpp::Tag_ABI_FP_optimization_goals: |
| // Use the first value seen. |
| break; |
| |
| case elfcpp::Tag_CPU_arch: |
| { |
| unsigned int saved_out_attr = out_attr->int_value(); |
| // Merge Tag_CPU_arch and Tag_also_compatible_with. |
| int secondary_compat = |
| this->get_secondary_compatible_arch(pasd); |
| int secondary_compat_out = |
| this->get_secondary_compatible_arch( |
| this->attributes_section_data_); |
| out_attr[i].set_int_value( |
| tag_cpu_arch_combine(name, out_attr[i].int_value(), |
| &secondary_compat_out, |
| in_attr[i].int_value(), |
| secondary_compat)); |
| this->set_secondary_compatible_arch(this->attributes_section_data_, |
| secondary_compat_out); |
| |
| // Merge Tag_CPU_name and Tag_CPU_raw_name. |
| if (out_attr[i].int_value() == saved_out_attr) |
| ; // Leave the names alone. |
| else if (out_attr[i].int_value() == in_attr[i].int_value()) |
| { |
| // The output architecture has been changed to match the |
| // input architecture. Use the input names. |
| out_attr[elfcpp::Tag_CPU_name].set_string_value( |
| in_attr[elfcpp::Tag_CPU_name].string_value()); |
| out_attr[elfcpp::Tag_CPU_raw_name].set_string_value( |
| in_attr[elfcpp::Tag_CPU_raw_name].string_value()); |
| } |
| else |
| { |
| out_attr[elfcpp::Tag_CPU_name].set_string_value(""); |
| out_attr[elfcpp::Tag_CPU_raw_name].set_string_value(""); |
| } |
| |
| // If we still don't have a value for Tag_CPU_name, |
| // make one up now. Tag_CPU_raw_name remains blank. |
| if (out_attr[elfcpp::Tag_CPU_name].string_value() == "") |
| { |
| const std::string cpu_name = |
| this->tag_cpu_name_value(out_attr[i].int_value()); |
| // FIXME: If we see an unknown CPU, this will be set |
| // to "<unknown CPU n>", where n is the attribute value. |
| // This is different from BFD, which leaves the name alone. |
| out_attr[elfcpp::Tag_CPU_name].set_string_value(cpu_name); |
| } |
| } |
| break; |
| |
| case elfcpp::Tag_ARM_ISA_use: |
| case elfcpp::Tag_THUMB_ISA_use: |
| case elfcpp::Tag_WMMX_arch: |
| case elfcpp::Tag_Advanced_SIMD_arch: |
| // ??? Do Advanced_SIMD (NEON) and WMMX conflict? |
| case elfcpp::Tag_ABI_FP_rounding: |
| case elfcpp::Tag_ABI_FP_exceptions: |
| case elfcpp::Tag_ABI_FP_user_exceptions: |
| case elfcpp::Tag_ABI_FP_number_model: |
| case elfcpp::Tag_VFP_HP_extension: |
| case elfcpp::Tag_CPU_unaligned_access: |
| case elfcpp::Tag_T2EE_use: |
| case elfcpp::Tag_Virtualization_use: |
| case elfcpp::Tag_MPextension_use: |
| // Use the largest value specified. |
| if (in_attr[i].int_value() > out_attr[i].int_value()) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| break; |
| |
| case elfcpp::Tag_ABI_align8_preserved: |
| case elfcpp::Tag_ABI_PCS_RO_data: |
| // Use the smallest value specified. |
| if (in_attr[i].int_value() < out_attr[i].int_value()) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| break; |
| |
| case elfcpp::Tag_ABI_align8_needed: |
| if ((in_attr[i].int_value() > 0 || out_attr[i].int_value() > 0) |
| && (in_attr[elfcpp::Tag_ABI_align8_preserved].int_value() == 0 |
| || (out_attr[elfcpp::Tag_ABI_align8_preserved].int_value() |
| == 0))) |
| { |
| // This error message should be enabled once all non-conformant |
| // binaries in the toolchain have had the attributes set |
| // properly. |
| // gold_error(_("output 8-byte data alignment conflicts with %s"), |
| // name); |
| } |
| // Fall through. |
| case elfcpp::Tag_ABI_FP_denormal: |
| case elfcpp::Tag_ABI_PCS_GOT_use: |
| { |
| // These tags have 0 = don't care, 1 = strong requirement, |
| // 2 = weak requirement. |
| static const int order_021[3] = {0, 2, 1}; |
| |
| // Use the "greatest" from the sequence 0, 2, 1, or the largest |
| // value if greater than 2 (for future-proofing). |
| if ((in_attr[i].int_value() > 2 |
| && in_attr[i].int_value() > out_attr[i].int_value()) |
| || (in_attr[i].int_value() <= 2 |
| && out_attr[i].int_value() <= 2 |
| && (order_021[in_attr[i].int_value()] |
| > order_021[out_attr[i].int_value()]))) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| } |
| break; |
| |
| case elfcpp::Tag_CPU_arch_profile: |
| if (out_attr[i].int_value() != in_attr[i].int_value()) |
| { |
| // 0 will merge with anything. |
| // 'A' and 'S' merge to 'A'. |
| // 'R' and 'S' merge to 'R'. |
| // 'M' and 'A|R|S' is an error. |
| if (out_attr[i].int_value() == 0 |
| || (out_attr[i].int_value() == 'S' |
| && (in_attr[i].int_value() == 'A' |
| || in_attr[i].int_value() == 'R'))) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| else if (in_attr[i].int_value() == 0 |
| || (in_attr[i].int_value() == 'S' |
| && (out_attr[i].int_value() == 'A' |
| || out_attr[i].int_value() == 'R'))) |
| ; // Do nothing. |
| else |
| { |
| gold_error |
| (_("conflicting architecture profiles %c/%c"), |
| in_attr[i].int_value() ? in_attr[i].int_value() : '0', |
| out_attr[i].int_value() ? out_attr[i].int_value() : '0'); |
| } |
| } |
| break; |
| case elfcpp::Tag_VFP_arch: |
| { |
| static const struct |
| { |
| int ver; |
| int regs; |
| } vfp_versions[7] = |
| { |
| {0, 0}, |
| {1, 16}, |
| {2, 16}, |
| {3, 32}, |
| {3, 16}, |
| {4, 32}, |
| {4, 16} |
| }; |
| |
| // Values greater than 6 aren't defined, so just pick the |
| // biggest. |
| if (in_attr[i].int_value() > 6 |
| && in_attr[i].int_value() > out_attr[i].int_value()) |
| { |
| *out_attr = *in_attr; |
| break; |
| } |
| // The output uses the superset of input features |
| // (ISA version) and registers. |
| int ver = std::max(vfp_versions[in_attr[i].int_value()].ver, |
| vfp_versions[out_attr[i].int_value()].ver); |
| int regs = std::max(vfp_versions[in_attr[i].int_value()].regs, |
| vfp_versions[out_attr[i].int_value()].regs); |
| // This assumes all possible supersets are also a valid |
| // options. |
| int newval; |
| for (newval = 6; newval > 0; newval--) |
| { |
| if (regs == vfp_versions[newval].regs |
| && ver == vfp_versions[newval].ver) |
| break; |
| } |
| out_attr[i].set_int_value(newval); |
| } |
| break; |
| case elfcpp::Tag_PCS_config: |
| if (out_attr[i].int_value() == 0) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| else if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0) |
| { |
| // It's sometimes ok to mix different configs, so this is only |
| // a warning. |
| gold_warning(_("%s: conflicting platform configuration"), name); |
| } |
| break; |
| case elfcpp::Tag_ABI_PCS_R9_use: |
| if (in_attr[i].int_value() != out_attr[i].int_value() |
| && out_attr[i].int_value() != elfcpp::AEABI_R9_unused |
| && in_attr[i].int_value() != elfcpp::AEABI_R9_unused) |
| { |
| gold_error(_("%s: conflicting use of R9"), name); |
| } |
| if (out_attr[i].int_value() == elfcpp::AEABI_R9_unused) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| break; |
| case elfcpp::Tag_ABI_PCS_RW_data: |
| if (in_attr[i].int_value() == elfcpp::AEABI_PCS_RW_data_SBrel |
| && (in_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value() |
| != elfcpp::AEABI_R9_SB) |
| && (out_attr[elfcpp::Tag_ABI_PCS_R9_use].int_value() |
| != elfcpp::AEABI_R9_unused)) |
| { |
| gold_error(_("%s: SB relative addressing conflicts with use " |
| "of R9"), |
| name); |
| } |
| // Use the smallest value specified. |
| if (in_attr[i].int_value() < out_attr[i].int_value()) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| break; |
| case elfcpp::Tag_ABI_PCS_wchar_t: |
| // FIXME: Make it possible to turn off this warning. |
| if (out_attr[i].int_value() |
| && in_attr[i].int_value() |
| && out_attr[i].int_value() != in_attr[i].int_value()) |
| { |
| gold_warning(_("%s uses %u-byte wchar_t yet the output is to " |
| "use %u-byte wchar_t; use of wchar_t values " |
| "across objects may fail"), |
| name, in_attr[i].int_value(), |
| out_attr[i].int_value()); |
| } |
| else if (in_attr[i].int_value() && !out_attr[i].int_value()) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| break; |
| case elfcpp::Tag_ABI_enum_size: |
| if (in_attr[i].int_value() != elfcpp::AEABI_enum_unused) |
| { |
| if (out_attr[i].int_value() == elfcpp::AEABI_enum_unused |
| || out_attr[i].int_value() == elfcpp::AEABI_enum_forced_wide) |
| { |
| // The existing object is compatible with anything. |
| // Use whatever requirements the new object has. |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| } |
| // FIXME: Make it possible to turn off this warning. |
| else if (in_attr[i].int_value() != elfcpp::AEABI_enum_forced_wide |
| && out_attr[i].int_value() != in_attr[i].int_value()) |
| { |
| unsigned int in_value = in_attr[i].int_value(); |
| unsigned int out_value = out_attr[i].int_value(); |
| gold_warning(_("%s uses %s enums yet the output is to use " |
| "%s enums; use of enum values across objects " |
| "may fail"), |
| name, |
| this->aeabi_enum_name(in_value).c_str(), |
| this->aeabi_enum_name(out_value).c_str()); |
| } |
| } |
| break; |
| case elfcpp::Tag_ABI_VFP_args: |
| // Aready done. |
| break; |
| case elfcpp::Tag_ABI_WMMX_args: |
| if (in_attr[i].int_value() != out_attr[i].int_value()) |
| { |
| gold_error(_("%s uses iWMMXt register arguments, output does " |
| "not"), |
| name); |
| } |
| break; |
| case Object_attribute::Tag_compatibility: |
| // Merged in target-independent code. |
| break; |
| case elfcpp::Tag_ABI_HardFP_use: |
| // 1 (SP) and 2 (DP) conflict, so combine to 3 (SP & DP). |
| if ((in_attr[i].int_value() == 1 && out_attr[i].int_value() == 2) |
| || (in_attr[i].int_value() == 2 && out_attr[i].int_value() == 1)) |
| out_attr[i].set_int_value(3); |
| else if (in_attr[i].int_value() > out_attr[i].int_value()) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| break; |
| case elfcpp::Tag_ABI_FP_16bit_format: |
| if (in_attr[i].int_value() != 0 && out_attr[i].int_value() != 0) |
| { |
| if (in_attr[i].int_value() != out_attr[i].int_value()) |
| gold_error(_("fp16 format mismatch between %s and output"), |
| name); |
| } |
| if (in_attr[i].int_value() != 0) |
| out_attr[i].set_int_value(in_attr[i].int_value()); |
| break; |
| |
| case elfcpp::Tag_nodefaults: |
| // This tag is set if it exists, but the value is unused (and is |
| // typically zero). We don't actually need to do anything here - |
| // the merge happens automatically when the type flags are merged |
| // below. |
| break; |
| case elfcpp::Tag_also_compatible_with: |
| // Already done in Tag_CPU_arch. |
| break; |
| case elfcpp::Tag_conformance: |
| // Keep the attribute if it matches. Throw it away otherwise. |
| // No attribute means no claim to conform. |
| if (in_attr[i].string_value() != out_attr[i].string_value()) |
| out_attr[i].set_string_value(""); |
| break; |
| |
| default: |
| { |
| const char* err_object = NULL; |
| |
| // The "known_obj_attributes" table does contain some undefined |
| // attributes. Ensure that there are unused. |
| if (out_attr[i].int_value() != 0 |
| || out_attr[i].string_value() != "") |
| err_object = "output"; |
| else if (in_attr[i].int_value() != 0 |
| || in_attr[i].string_value() != "") |
| err_object = name; |
| |
| if (err_object != NULL) |
| { |
| // Attribute numbers >=64 (mod 128) can be safely ignored. |
| if ((i & 127) < 64) |
| gold_error(_("%s: unknown mandatory EABI object attribute " |
| "%d"), |
| err_object, i); |
| else |
| gold_warning(_("%s: unknown EABI object attribute %d"), |
| err_object, i); |
| } |
| |
| // Only pass on attributes that match in both inputs. |
| if (!in_attr[i].matches(out_attr[i])) |
| { |
| out_attr[i].set_int_value(0); |
| out_attr[i].set_string_value(""); |
| } |
| } |
| } |
| |
| // If out_attr was copied from in_attr then it won't have a type yet. |
| if (in_attr[i].type() && !out_attr[i].type()) |
| out_attr[i].set_type(in_attr[i].type()); |
| } |
| |
| // Merge Tag_compatibility attributes and any common GNU ones. |
| this->attributes_section_data_->merge(name, pasd); |
| |
| // Check for any attributes not known on ARM. |
| typedef Vendor_object_attributes::Other_attributes Other_attributes; |
| const Other_attributes* in_other_attributes = pasd->other_attributes(vendor); |
| Other_attributes::const_iterator in_iter = in_other_attributes->begin(); |
| Other_attributes* out_other_attributes = |
| this->attributes_section_data_->other_attributes(vendor); |
| Other_attributes::iterator out_iter = out_other_attributes->begin(); |
| |
| while (in_iter != in_other_attributes->end() |
| || out_iter != out_other_attributes->end()) |
| { |
| const char* err_object = NULL; |
| int err_tag = 0; |
| |
| // The tags for each list are in numerical order. |
| // If the tags are equal, then merge. |
| if (out_iter != out_other_attributes->end() |
| && (in_iter == in_other_attributes->end() |
| || in_iter->first > out_iter->first)) |
| { |
| // This attribute only exists in output. We can't merge, and we |
| // don't know what the tag means, so delete it. |
| err_object = "output"; |
| err_tag = out_iter->first; |
| int saved_tag = out_iter->first; |
| delete out_iter->second; |
| out_other_attributes->erase(out_iter); |
| out_iter = out_other_attributes->upper_bound(saved_tag); |
| } |
| else if (in_iter != in_other_attributes->end() |
| && (out_iter != out_other_attributes->end() |
| || in_iter->first < out_iter->first)) |
| { |
| // This attribute only exists in input. We can't merge, and we |
| // don't know what the tag means, so ignore it. |
| err_object = name; |
| err_tag = in_iter->first; |
| ++in_iter; |
| } |
| else // The tags are equal. |
| { |
| // As present, all attributes in the list are unknown, and |
| // therefore can't be merged meaningfully. |
| err_object = "output"; |
| err_tag = out_iter->first; |
| |
| // Only pass on attributes that match in both inputs. |
| if (!in_iter->second->matches(*(out_iter->second))) |
| { |
| // No match. Delete the attribute. |
| int saved_tag = out_iter->first; |
| delete out_iter->second; |
| out_other_attributes->erase(out_iter); |
| out_iter = out_other_attributes->upper_bound(saved_tag); |
| } |
| else |
| { |
| // Matched. Keep the attribute and move to the next. |
| ++out_iter; |
| ++in_iter; |
| } |
| } |
| |
| if (err_object) |
| { |
| // Attribute numbers >=64 (mod 128) can be safely ignored. */ |
| if ((err_tag & 127) < 64) |
| { |
| gold_error(_("%s: unknown mandatory EABI object attribute %d"), |
| err_object, err_tag); |
| } |
| else |
| { |
| gold_warning(_("%s: unknown EABI object attribute %d"), |
| err_object, err_tag); |
| } |
| } |
| } |
| } |
| |
| // Return whether a relocation type used the LSB to distinguish THUMB |
| // addresses. |
| template<bool big_endian> |
| bool |
| Target_arm<big_endian>::reloc_uses_thumb_bit(unsigned int r_type) |
| { |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_PC24: |
| case elfcpp::R_ARM_ABS32: |
| case elfcpp::R_ARM_REL32: |
| case elfcpp::R_ARM_SBREL32: |
| case elfcpp::R_ARM_THM_CALL: |
| case elfcpp::R_ARM_GLOB_DAT: |
| case elfcpp::R_ARM_JUMP_SLOT: |
| case elfcpp::R_ARM_GOTOFF32: |
| case elfcpp::R_ARM_PLT32: |
| case elfcpp::R_ARM_CALL: |
| case elfcpp::R_ARM_JUMP24: |
| case elfcpp::R_ARM_THM_JUMP24: |
| case elfcpp::R_ARM_SBREL31: |
| case elfcpp::R_ARM_PREL31: |
| case elfcpp::R_ARM_MOVW_ABS_NC: |
| case elfcpp::R_ARM_MOVW_PREL_NC: |
| case elfcpp::R_ARM_THM_MOVW_ABS_NC: |
| case elfcpp::R_ARM_THM_MOVW_PREL_NC: |
| case elfcpp::R_ARM_THM_JUMP19: |
| case elfcpp::R_ARM_THM_ALU_PREL_11_0: |
| case elfcpp::R_ARM_ALU_PC_G0_NC: |
| case elfcpp::R_ARM_ALU_PC_G0: |
| case elfcpp::R_ARM_ALU_PC_G1_NC: |
| case elfcpp::R_ARM_ALU_PC_G1: |
| case elfcpp::R_ARM_ALU_PC_G2: |
| case elfcpp::R_ARM_ALU_SB_G0_NC: |
| case elfcpp::R_ARM_ALU_SB_G0: |
| case elfcpp::R_ARM_ALU_SB_G1_NC: |
| case elfcpp::R_ARM_ALU_SB_G1: |
| case elfcpp::R_ARM_ALU_SB_G2: |
| case elfcpp::R_ARM_MOVW_BREL_NC: |
| case elfcpp::R_ARM_MOVW_BREL: |
| case elfcpp::R_ARM_THM_MOVW_BREL_NC: |
| case elfcpp::R_ARM_THM_MOVW_BREL: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| // Stub-generation methods for Target_arm. |
| |
| // Make a new Arm_input_section object. |
| |
| template<bool big_endian> |
| Arm_input_section<big_endian>* |
| Target_arm<big_endian>::new_arm_input_section( |
| Relobj* relobj, |
| unsigned int shndx) |
| { |
| Input_section_specifier iss(relobj, shndx); |
| |
| Arm_input_section<big_endian>* arm_input_section = |
| new Arm_input_section<big_endian>(relobj, shndx); |
| arm_input_section->init(); |
| |
| // Register new Arm_input_section in map for look-up. |
| std::pair<typename Arm_input_section_map::iterator, bool> ins = |
| this->arm_input_section_map_.insert(std::make_pair(iss, arm_input_section)); |
| |
| // Make sure that it we have not created another Arm_input_section |
| // for this input section already. |
| gold_assert(ins.second); |
| |
| return arm_input_section; |
| } |
| |
| // Find the Arm_input_section object corresponding to the SHNDX-th input |
| // section of RELOBJ. |
| |
| template<bool big_endian> |
| Arm_input_section<big_endian>* |
| Target_arm<big_endian>::find_arm_input_section( |
| Relobj* relobj, |
| unsigned int shndx) const |
| { |
| Input_section_specifier iss(relobj, shndx); |
| typename Arm_input_section_map::const_iterator p = |
| this->arm_input_section_map_.find(iss); |
| return (p != this->arm_input_section_map_.end()) ? p->second : NULL; |
| } |
| |
| // Make a new stub table. |
| |
| template<bool big_endian> |
| Stub_table<big_endian>* |
| Target_arm<big_endian>::new_stub_table(Arm_input_section<big_endian>* owner) |
| { |
| Stub_table<big_endian>* stub_table = |
| new Stub_table<big_endian>(owner); |
| this->stub_tables_.push_back(stub_table); |
| |
| stub_table->set_address(owner->address() + owner->data_size()); |
| stub_table->set_file_offset(owner->offset() + owner->data_size()); |
| stub_table->finalize_data_size(); |
| |
| return stub_table; |
| } |
| |
| // Scan a relocation for stub generation. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::scan_reloc_for_stub( |
| const Relocate_info<32, big_endian>* relinfo, |
| unsigned int r_type, |
| const Sized_symbol<32>* gsym, |
| unsigned int r_sym, |
| const Symbol_value<32>* psymval, |
| elfcpp::Elf_types<32>::Elf_Swxword addend, |
| Arm_address address) |
| { |
| typedef typename Target_arm<big_endian>::Relocate Relocate; |
| |
| const Arm_relobj<big_endian>* arm_relobj = |
| Arm_relobj<big_endian>::as_arm_relobj(relinfo->object); |
| |
| bool target_is_thumb; |
| Symbol_value<32> symval; |
| if (gsym != NULL) |
| { |
| // This is a global symbol. Determine if we use PLT and if the |
| // final target is THUMB. |
| if (gsym->use_plt_offset(Relocate::reloc_is_non_pic(r_type))) |
| { |
| // This uses a PLT, change the symbol value. |
| symval.set_output_value(this->plt_section()->address() |
| + gsym->plt_offset()); |
| psymval = &symval; |
| target_is_thumb = false; |
| } |
| else if (gsym->is_undefined()) |
| // There is no need to generate a stub symbol is undefined. |
| return; |
| else |
| { |
| target_is_thumb = |
| ((gsym->type() == elfcpp::STT_ARM_TFUNC) |
| || (gsym->type() == elfcpp::STT_FUNC |
| && !gsym->is_undefined() |
| && ((psymval->value(arm_relobj, 0) & 1) != 0))); |
| } |
| } |
| else |
| { |
| // This is a local symbol. Determine if the final target is THUMB. |
| target_is_thumb = arm_relobj->local_symbol_is_thumb_function(r_sym); |
| } |
| |
| // Strip LSB if this points to a THUMB target. |
| if (target_is_thumb |
| && Target_arm<big_endian>::reloc_uses_thumb_bit(r_type) |
| && ((psymval->value(arm_relobj, 0) & 1) != 0)) |
| { |
| Arm_address stripped_value = |
| psymval->value(arm_relobj, 0) & ~static_cast<Arm_address>(1); |
| symval.set_output_value(stripped_value); |
| psymval = &symval; |
| } |
| |
| // Get the symbol value. |
| Symbol_value<32>::Value value = psymval->value(arm_relobj, 0); |
| |
| // Owing to pipelining, the PC relative branches below actually skip |
| // two instructions when the branch offset is 0. |
| Arm_address destination; |
| switch (r_type) |
| { |
| case elfcpp::R_ARM_CALL: |
| case elfcpp::R_ARM_JUMP24: |
| case elfcpp::R_ARM_PLT32: |
| // ARM branches. |
| destination = value + addend + 8; |
| break; |
| case elfcpp::R_ARM_THM_CALL: |
| case elfcpp::R_ARM_THM_XPC22: |
| case elfcpp::R_ARM_THM_JUMP24: |
| case elfcpp::R_ARM_THM_JUMP19: |
| // THUMB branches. |
| destination = value + addend + 4; |
| break; |
| default: |
| gold_unreachable(); |
| } |
| |
| Stub_type stub_type = |
| Reloc_stub::stub_type_for_reloc(r_type, address, destination, |
| target_is_thumb); |
| |
| // This reloc does not need a stub. |
| if (stub_type == arm_stub_none) |
| return; |
| |
| // Try looking up an existing stub from a stub table. |
| Stub_table<big_endian>* stub_table = |
| arm_relobj->stub_table(relinfo->data_shndx); |
| gold_assert(stub_table != NULL); |
| |
| // Locate stub by destination. |
| Reloc_stub::Key stub_key(stub_type, gsym, arm_relobj, r_sym, addend); |
| |
| // Create a stub if there is not one already |
| Reloc_stub* stub = stub_table->find_reloc_stub(stub_key); |
| if (stub == NULL) |
| { |
| // create a new stub and add it to stub table. |
| stub = this->stub_factory().make_reloc_stub(stub_type); |
| stub_table->add_reloc_stub(stub, stub_key); |
| } |
| |
| // Record the destination address. |
| stub->set_destination_address(destination |
| | (target_is_thumb ? 1 : 0)); |
| } |
| |
| // This function scans a relocation sections for stub generation. |
| // The template parameter Relocate must be a class type which provides |
| // a single function, relocate(), which implements the machine |
| // specific part of a relocation. |
| |
| // BIG_ENDIAN is the endianness of the data. SH_TYPE is the section type: |
| // SHT_REL or SHT_RELA. |
| |
| // PRELOCS points to the relocation data. RELOC_COUNT is the number |
| // of relocs. OUTPUT_SECTION is the output section. |
| // NEEDS_SPECIAL_OFFSET_HANDLING is true if input offsets need to be |
| // mapped to output offsets. |
| |
| // VIEW is the section data, VIEW_ADDRESS is its memory address, and |
| // VIEW_SIZE is the size. These refer to the input section, unless |
| // NEEDS_SPECIAL_OFFSET_HANDLING is true, in which case they refer to |
| // the output section. |
| |
| template<bool big_endian> |
| template<int sh_type> |
| void inline |
| Target_arm<big_endian>::scan_reloc_section_for_stubs( |
| const Relocate_info<32, big_endian>* relinfo, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| const unsigned char* view, |
| elfcpp::Elf_types<32>::Elf_Addr view_address, |
| section_size_type) |
| { |
| typedef typename Reloc_types<sh_type, 32, big_endian>::Reloc Reltype; |
| const int reloc_size = |
| Reloc_types<sh_type, 32, big_endian>::reloc_size; |
| |
| Arm_relobj<big_endian>* arm_object = |
| Arm_relobj<big_endian>::as_arm_relobj(relinfo->object); |
| unsigned int local_count = arm_object->local_symbol_count(); |
| |
| Comdat_behavior comdat_behavior = CB_UNDETERMINED; |
| |
| for (size_t i = 0; i < reloc_count; ++i, prelocs += reloc_size) |
| { |
| Reltype reloc(prelocs); |
| |
| typename elfcpp::Elf_types<32>::Elf_WXword r_info = reloc.get_r_info(); |
| unsigned int r_sym = elfcpp::elf_r_sym<32>(r_info); |
| unsigned int r_type = elfcpp::elf_r_type<32>(r_info); |
| |
| r_type = this->get_real_reloc_type(r_type); |
| |
| // Only a few relocation types need stubs. |
| if ((r_type != elfcpp::R_ARM_CALL) |
| && (r_type != elfcpp::R_ARM_JUMP24) |
| && (r_type != elfcpp::R_ARM_PLT32) |
| && (r_type != elfcpp::R_ARM_THM_CALL) |
| && (r_type != elfcpp::R_ARM_THM_XPC22) |
| && (r_type != elfcpp::R_ARM_THM_JUMP24) |
| && (r_type != elfcpp::R_ARM_THM_JUMP19)) |
| continue; |
| |
| section_offset_type offset = |
| convert_to_section_size_type(reloc.get_r_offset()); |
| |
| if (needs_special_offset_handling) |
| { |
| offset = output_section->output_offset(relinfo->object, |
| relinfo->data_shndx, |
| offset); |
| if (offset == -1) |
| continue; |
| } |
| |
| // Get the addend. |
| Stub_addend_reader<sh_type, big_endian> stub_addend_reader; |
| elfcpp::Elf_types<32>::Elf_Swxword addend = |
| stub_addend_reader(r_type, view + offset, reloc); |
| |
| const Sized_symbol<32>* sym; |
| |
| Symbol_value<32> symval; |
| const Symbol_value<32> *psymval; |
| if (r_sym < local_count) |
| { |
| sym = NULL; |
| psymval = arm_object->local_symbol(r_sym); |
| |
| // If the local symbol belongs to a section we are discarding, |
| // and that section is a debug section, try to find the |
| // corresponding kept section and map this symbol to its |
| // counterpart in the kept section. The symbol must not |
| // correspond to a section we are folding. |
| bool is_ordinary; |
| unsigned int shndx = psymval->input_shndx(&is_ordinary); |
| if (is_ordinary |
| && shndx != elfcpp::SHN_UNDEF |
| && !arm_object->is_section_included(shndx) |
| && !(relinfo->symtab->is_section_folded(arm_object, shndx))) |
| { |
| if (comdat_behavior == CB_UNDETERMINED) |
| { |
| std::string name = |
| arm_object->section_name(relinfo->data_shndx); |
| comdat_behavior = get_comdat_behavior(name.c_str()); |
| } |
| if (comdat_behavior == CB_PRETEND) |
| { |
| bool found; |
| typename elfcpp::Elf_types<32>::Elf_Addr value = |
| arm_object->map_to_kept_section(shndx, &found); |
| if (found) |
| symval.set_output_value(value + psymval->input_value()); |
| else |
| symval.set_output_value(0); |
| } |
| else |
| { |
| symval.set_output_value(0); |
| } |
| symval.set_no_output_symtab_entry(); |
| psymval = &symval; |
| } |
| } |
| else |
| { |
| const Symbol* gsym = arm_object->global_symbol(r_sym); |
| gold_assert(gsym != NULL); |
| if (gsym->is_forwarder()) |
| gsym = relinfo->symtab->resolve_forwards(gsym); |
| |
| sym = static_cast<const Sized_symbol<32>*>(gsym); |
| if (sym->has_symtab_index()) |
| symval.set_output_symtab_index(sym->symtab_index()); |
| else |
| symval.set_no_output_symtab_entry(); |
| |
| // We need to compute the would-be final value of this global |
| // symbol. |
| const Symbol_table* symtab = relinfo->symtab; |
| const Sized_symbol<32>* sized_symbol = |
| symtab->get_sized_symbol<32>(gsym); |
| Symbol_table::Compute_final_value_status status; |
| Arm_address value = |
| symtab->compute_final_value<32>(sized_symbol, &status); |
| |
| // Skip this if the symbol has not output section. |
| if (status == Symbol_table::CFVS_NO_OUTPUT_SECTION) |
| continue; |
| |
| symval.set_output_value(value); |
| psymval = &symval; |
| } |
| |
| // If symbol is a section symbol, we don't know the actual type of |
| // destination. Give up. |
| if (psymval->is_section_symbol()) |
| continue; |
| |
| this->scan_reloc_for_stub(relinfo, r_type, sym, r_sym, psymval, |
| addend, view_address + offset); |
| } |
| } |
| |
| // Scan an input section for stub generation. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::scan_section_for_stubs( |
| const Relocate_info<32, big_endian>* relinfo, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| Output_section* output_section, |
| bool needs_special_offset_handling, |
| const unsigned char* view, |
| Arm_address view_address, |
| section_size_type view_size) |
| { |
| if (sh_type == elfcpp::SHT_REL) |
| this->scan_reloc_section_for_stubs<elfcpp::SHT_REL>( |
| relinfo, |
| prelocs, |
| reloc_count, |
| output_section, |
| needs_special_offset_handling, |
| view, |
| view_address, |
| view_size); |
| else if (sh_type == elfcpp::SHT_RELA) |
| // We do not support RELA type relocations yet. This is provided for |
| // completeness. |
| this->scan_reloc_section_for_stubs<elfcpp::SHT_RELA>( |
| relinfo, |
| prelocs, |
| reloc_count, |
| output_section, |
| needs_special_offset_handling, |
| view, |
| view_address, |
| view_size); |
| else |
| gold_unreachable(); |
| } |
| |
| // Group input sections for stub generation. |
| // |
| // We goup input sections in an output sections so that the total size, |
| // including any padding space due to alignment is smaller than GROUP_SIZE |
| // unless the only input section in group is bigger than GROUP_SIZE already. |
| // Then an ARM stub table is created to follow the last input section |
| // in group. For each group an ARM stub table is created an is placed |
| // after the last group. If STUB_ALWATS_AFTER_BRANCH is false, we further |
| // extend the group after the stub table. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::group_sections( |
| Layout* layout, |
| section_size_type group_size, |
| bool stubs_always_after_branch) |
| { |
| // Group input sections and insert stub table |
| Layout::Section_list section_list; |
| layout->get_allocated_sections(§ion_list); |
| for (Layout::Section_list::const_iterator p = section_list.begin(); |
| p != section_list.end(); |
| ++p) |
| { |
| Arm_output_section<big_endian>* output_section = |
| Arm_output_section<big_endian>::as_arm_output_section(*p); |
| output_section->group_sections(group_size, stubs_always_after_branch, |
| this); |
| } |
| } |
| |
| // Relaxation hook. This is where we do stub generation. |
| |
| template<bool big_endian> |
| bool |
| Target_arm<big_endian>::do_relax( |
| int pass, |
| const Input_objects* input_objects, |
| Symbol_table* symtab, |
| Layout* layout) |
| { |
| // No need to generate stubs if this is a relocatable link. |
| gold_assert(!parameters->options().relocatable()); |
| |
| // If this is the first pass, we need to group input sections into |
| // stub groups. |
| if (pass == 1) |
| { |
| // Determine the stub group size. The group size is the absolute |
| // value of the parameter --stub-group-size. If --stub-group-size |
| // is passed a negative value, we restict stubs to be always after |
| // the stubbed branches. |
| int32_t stub_group_size_param = |
| parameters->options().stub_group_size(); |
| bool stubs_always_after_branch = stub_group_size_param < 0; |
| section_size_type stub_group_size = abs(stub_group_size_param); |
| |
| if (stub_group_size == 1) |
| { |
| // Default value. |
| // Thumb branch range is +-4MB has to be used as the default |
| // maximum size (a given section can contain both ARM and Thumb |
| // code, so the worst case has to be taken into account). |
| // |
| // This value is 24K less than that, which allows for 2025 |
| // 12-byte stubs. If we exceed that, then we will fail to link. |
| // The user will have to relink with an explicit group size |
| // option. |
| stub_group_size = 4170000; |
| } |
| |
| group_sections(layout, stub_group_size, stubs_always_after_branch); |
| } |
| |
| // clear changed flags for all stub_tables |
| typedef typename Stub_table_list::iterator Stub_table_iterator; |
| for (Stub_table_iterator sp = this->stub_tables_.begin(); |
| sp != this->stub_tables_.end(); |
| ++sp) |
| (*sp)->set_has_been_changed(false); |
| |
| // scan relocs for stubs |
| for (Input_objects::Relobj_iterator op = input_objects->relobj_begin(); |
| op != input_objects->relobj_end(); |
| ++op) |
| { |
| Arm_relobj<big_endian>* arm_relobj = |
| Arm_relobj<big_endian>::as_arm_relobj(*op); |
| arm_relobj->scan_sections_for_stubs(this, symtab, layout); |
| } |
| |
| bool any_stub_table_changed = false; |
| for (Stub_table_iterator sp = this->stub_tables_.begin(); |
| (sp != this->stub_tables_.end()) && !any_stub_table_changed; |
| ++sp) |
| { |
| if ((*sp)->has_been_changed()) |
| any_stub_table_changed = true; |
| } |
| |
| return any_stub_table_changed; |
| } |
| |
| // Relocate a stub. |
| |
| template<bool big_endian> |
| void |
| Target_arm<big_endian>::relocate_stub( |
| Reloc_stub* stub, |
| const Relocate_info<32, big_endian>* relinfo, |
| Output_section* output_section, |
| unsigned char* view, |
| Arm_address address, |
| section_size_type view_size) |
| { |
| Relocate relocate; |
| const Stub_template* stub_template = stub->stub_template(); |
| for (size_t i = 0; i < stub_template->reloc_count(); i++) |
| { |
| size_t reloc_insn_index = stub_template->reloc_insn_index(i); |
| const Insn_template* insn = &stub_template->insns()[reloc_insn_index]; |
| |
| unsigned int r_type = insn->r_type(); |
| section_size_type reloc_offset = stub_template->reloc_offset(i); |
| section_size_type reloc_size = insn->size(); |
| gold_assert(reloc_offset + reloc_size <= view_size); |
| |
| // This is the address of the stub destination. |
| Arm_address target = stub->reloc_target(i); |
| Symbol_value<32> symval; |
| symval.set_output_value(target); |
| |
| // Synthesize a fake reloc just in case. We don't have a symbol so |
| // we use 0. |
| unsigned char reloc_buffer[elfcpp::Elf_sizes<32>::rel_size]; |
| memset(reloc_buffer, 0, sizeof(reloc_buffer)); |
| elfcpp::Rel_write<32, big_endian> reloc_write(reloc_buffer); |
| reloc_write.put_r_offset(reloc_offset); |
| reloc_write.put_r_info(elfcpp::elf_r_info<32>(0, r_type)); |
| elfcpp::Rel<32, big_endian> rel(reloc_buffer); |
| |
| relocate.relocate(relinfo, this, output_section, |
| this->fake_relnum_for_stubs, rel, r_type, |
| NULL, &symval, view + reloc_offset, |
| address + reloc_offset, reloc_size); |
| } |
| } |
| |
| // Determine whether an object attribute tag takes an integer, a |
| // string or both. |
| |
| template<bool big_endian> |
| int |
| Target_arm<big_endian>::do_attribute_arg_type(int tag) const |
| { |
| if (tag == Object_attribute::Tag_compatibility) |
| return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL |
| | Object_attribute::ATTR_TYPE_FLAG_STR_VAL); |
| else if (tag == elfcpp::Tag_nodefaults) |
| return (Object_attribute::ATTR_TYPE_FLAG_INT_VAL |
| | Object_attribute::ATTR_TYPE_FLAG_NO_DEFAULT); |
| else if (tag == elfcpp::Tag_CPU_raw_name || tag == elfcpp::Tag_CPU_name) |
| return Object_attribute::ATTR_TYPE_FLAG_STR_VAL; |
| else if (tag < 32) |
| return Object_attribute::ATTR_TYPE_FLAG_INT_VAL; |
| else |
| return ((tag & 1) != 0 |
| ? Object_attribute::ATTR_TYPE_FLAG_STR_VAL |
| : Object_attribute::ATTR_TYPE_FLAG_INT_VAL); |
| } |
| |
| // Reorder attributes. |
| // |
| // The ABI defines that Tag_conformance should be emitted first, and that |
| // Tag_nodefaults should be second (if either is defined). This sets those |
| // two positions, and bumps up the position of all the remaining tags to |
| // compensate. |
| |
| template<bool big_endian> |
| int |
| Target_arm<big_endian>::do_attributes_order(int num) const |
| { |
| // Reorder the known object attributes in output. We want to move |
| // Tag_conformance to position 4 and Tag_conformance to position 5 |
| // and shift eveything between 4 .. Tag_conformance - 1 to make room. |
| if (num == 4) |
| return elfcpp::Tag_conformance; |
| if (num == 5) |
| return elfcpp::Tag_nodefaults; |
| if ((num - 2) < elfcpp::Tag_nodefaults) |
| return num - 2; |
| if ((num - 1) < elfcpp::Tag_conformance) |
| return num - 1; |
| return num; |
| } |
| |
| template<bool big_endian> |
| class Target_selector_arm : public Target_selector |
| { |
| public: |
| Target_selector_arm() |
| : Target_selector(elfcpp::EM_ARM, 32, big_endian, |
| (big_endian ? "elf32-bigarm" : "elf32-littlearm")) |
| { } |
| |
| Target* |
| do_instantiate_target() |
| { return new Target_arm<big_endian>(); } |
| }; |
| |
| Target_selector_arm<false> target_selector_arm; |
| Target_selector_arm<true> target_selector_armbe; |
| |
| } // End anonymous namespace. |