| // i386.cc -- i386 target support for gold. |
| |
| #include "gold.h" |
| |
| #include <cstring> |
| |
| #include "elfcpp.h" |
| #include "reloc.h" |
| #include "i386.h" |
| #include "object.h" |
| #include "symtab.h" |
| #include "layout.h" |
| #include "output.h" |
| #include "target.h" |
| #include "target-reloc.h" |
| #include "target-select.h" |
| |
| namespace |
| { |
| |
| using namespace gold; |
| |
| // The i386 target class. |
| |
| class Target_i386 : public Sized_target<32, false> |
| { |
| public: |
| Target_i386() |
| : Sized_target<32, false>(&i386_info), |
| got_(NULL) |
| { } |
| |
| // Scan the relocations to look for symbol adjustments. |
| void |
| scan_relocs(const General_options& options, |
| Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, false>* object, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| size_t local_symbol_count, |
| const unsigned char* plocal_symbols, |
| Symbol** global_symbols); |
| |
| // Relocate a section. |
| void |
| relocate_section(const Relocate_info<32, false>*, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| unsigned char* view, |
| elfcpp::Elf_types<32>::Elf_Addr view_address, |
| off_t view_size); |
| |
| private: |
| // The class which scans relocations. |
| struct Scan |
| { |
| inline void |
| local(const General_options& options, Symbol_table* symtab, |
| Layout* layout, Target_i386* target, |
| Sized_relobj<32, false>* object, |
| const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
| const elfcpp::Sym<32, false>& lsym); |
| |
| inline void |
| global(const General_options& options, Symbol_table* symtab, |
| Layout* layout, Target_i386* target, |
| Sized_relobj<32, false>* object, |
| const elfcpp::Rel<32, false>& reloc, unsigned int r_type, |
| Symbol* gsym); |
| }; |
| |
| // The class which implements relocation. |
| class Relocate |
| { |
| public: |
| Relocate() |
| : skip_call_tls_get_addr_(false) |
| { } |
| |
| ~Relocate() |
| { |
| if (this->skip_call_tls_get_addr_) |
| { |
| // FIXME: This needs to specify the location somehow. |
| fprintf(stderr, _("%s: missing expected TLS relocation\n"), |
| program_name); |
| gold_exit(false); |
| } |
| } |
| |
| // Do a relocation. Return false if the caller should not issue |
| // any warnings about this relocation. |
| inline bool |
| relocate(const Relocate_info<32, false>*, Target_i386*, size_t relnum, |
| const elfcpp::Rel<32, false>&, |
| unsigned int r_type, Sized_symbol<32>*, |
| elfcpp::Elf_types<32>::Elf_Addr, |
| unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, |
| off_t); |
| |
| private: |
| // Do a TLS relocation. |
| inline void |
| relocate_tls(const Relocate_info<32, false>*, size_t relnum, |
| const elfcpp::Rel<32, false>&, |
| unsigned int r_type, Sized_symbol<32>*, |
| elfcpp::Elf_types<32>::Elf_Addr, |
| unsigned char*, elfcpp::Elf_types<32>::Elf_Addr, off_t); |
| |
| // Do a TLS Initial-Exec to Local-Exec transition. |
| static inline void |
| tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum, |
| Output_segment* tls_segment, |
| const elfcpp::Rel<32, false>&, unsigned int r_type, |
| elfcpp::Elf_types<32>::Elf_Addr value, |
| unsigned char* view, |
| off_t view_size); |
| |
| // Do a TLS Global-Dynamic to Local-Exec transition. |
| inline void |
| tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum, |
| Output_segment* tls_segment, |
| const elfcpp::Rel<32, false>&, unsigned int r_type, |
| elfcpp::Elf_types<32>::Elf_Addr value, |
| unsigned char* view, |
| off_t view_size); |
| |
| // Check the range for a TLS relocation. |
| static inline void |
| check_range(const Relocate_info<32, false>*, size_t relnum, |
| const elfcpp::Rel<32, false>&, off_t, off_t); |
| |
| // Check the validity of a TLS relocation. This is like assert. |
| static inline void |
| check_tls(const Relocate_info<32, false>*, size_t relnum, |
| const elfcpp::Rel<32, false>&, bool); |
| |
| // This is set if we should skip the next reloc, which should be a |
| // PLT32 reloc against ___tls_get_addr. |
| bool skip_call_tls_get_addr_; |
| }; |
| |
| // Adjust TLS relocation type based on the options and whether this |
| // is a local symbol. |
| static unsigned int |
| optimize_tls_reloc(const General_options*, bool is_local, int r_type); |
| |
| // Get the GOT section, creating it if necessary. |
| Output_data_got<32, false>* |
| got_section(Symbol_table*, Layout*); |
| |
| // Information about this specific target which we pass to the |
| // general Target structure. |
| static const Target::Target_info i386_info; |
| |
| // The GOT section. |
| Output_data_got<32, false>* got_; |
| }; |
| |
| const Target::Target_info Target_i386::i386_info = |
| { |
| 32, // size |
| false, // is_big_endian |
| elfcpp::EM_386, // machine_code |
| false, // has_make_symbol |
| false, // has_resolve |
| "/usr/lib/libc.so.1", // dynamic_linker |
| 0x08048000, // text_segment_address |
| 0x1000, // abi_pagesize |
| 0x1000 // common_pagesize |
| }; |
| |
| // Get the GOT section, creating it if necessary. |
| |
| Output_data_got<32, false>* |
| Target_i386::got_section(Symbol_table* symtab, Layout* layout) |
| { |
| if (this->got_ == NULL) |
| { |
| this->got_ = new Output_data_got<32, false>(); |
| |
| assert(symtab != NULL && layout != NULL); |
| layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| elfcpp::SHF_ALLOC, this->got_); |
| |
| // The first three entries are reserved. |
| this->got_->add_constant(0); |
| this->got_->add_constant(0); |
| this->got_->add_constant(0); |
| |
| // Define _GLOBAL_OFFSET_TABLE_ at the start of the section. |
| symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", this->got_, |
| 0, 0, elfcpp::STT_OBJECT, |
| elfcpp::STB_GLOBAL, |
| elfcpp::STV_HIDDEN, 0, |
| false, false); |
| } |
| return this->got_; |
| } |
| |
| // Optimize the TLS relocation type based on what we know about the |
| // symbol. IS_LOCAL is true if this symbol can be resolved entirely |
| // locally--i.e., does not have to be in the dynamic symbol table. |
| |
| unsigned int |
| Target_i386::optimize_tls_reloc(const General_options* options, bool is_local, |
| int r_type) |
| { |
| // If we are generating a shared library, then we can't do anything |
| // in the linker. |
| if (options->is_shared()) |
| return r_type; |
| |
| switch (r_type) |
| { |
| case elfcpp::R_386_TLS_GD: |
| case elfcpp::R_386_TLS_GOTDESC: |
| case elfcpp::R_386_TLS_DESC_CALL: |
| // These are Global-Dynamic which permits fully general TLS |
| // access. Since we know that we are generating an executable, |
| // we can convert this to Initial-Exec. If we also know that |
| // this is a local symbol, we can further switch to Local-Exec. |
| if (is_local) |
| return elfcpp::R_386_TLS_LE_32; |
| return elfcpp::R_386_TLS_IE_32; |
| |
| case elfcpp::R_386_TLS_LDM: |
| // This is Local-Dynamic, which refers to a local symbol in the |
| // dynamic TLS block. Since we know that we generating an |
| // executable, we can switch to Local-Exec. |
| return elfcpp::R_386_TLS_LE_32; |
| |
| case elfcpp::R_386_TLS_LDO_32: |
| // Another type of Local-Dynamic relocation. |
| return elfcpp::R_386_TLS_LE; |
| |
| case elfcpp::R_386_TLS_IE: |
| case elfcpp::R_386_TLS_GOTIE: |
| case elfcpp::R_386_TLS_IE_32: |
| // These are Initial-Exec relocs which get the thread offset |
| // from the GOT. If we know that we are linking against the |
| // local symbol, we can switch to Local-Exec, which links the |
| // thread offset into the instruction. |
| if (is_local) |
| return elfcpp::R_386_TLS_LE_32; |
| return r_type; |
| |
| case elfcpp::R_386_TLS_LE: |
| case elfcpp::R_386_TLS_LE_32: |
| // When we already have Local-Exec, there is nothing further we |
| // can do. |
| return r_type; |
| |
| default: |
| abort(); |
| } |
| } |
| |
| // Scan a relocation for a local symbol. |
| |
| inline void |
| Target_i386::Scan::local(const General_options& options, |
| Symbol_table* symtab, |
| Layout* layout, |
| Target_i386* target, |
| Sized_relobj<32, false>* object, |
| const elfcpp::Rel<32, false>&, unsigned int r_type, |
| const elfcpp::Sym<32, false>&) |
| { |
| switch (r_type) |
| { |
| case elfcpp::R_386_NONE: |
| case elfcpp::R_386_GNU_VTINHERIT: |
| case elfcpp::R_386_GNU_VTENTRY: |
| break; |
| |
| case elfcpp::R_386_32: |
| case elfcpp::R_386_16: |
| case elfcpp::R_386_8: |
| // FIXME: If we are generating a shared object we need to copy |
| // this relocation into the object. |
| break; |
| |
| case elfcpp::R_386_PC32: |
| case elfcpp::R_386_PC16: |
| case elfcpp::R_386_PC8: |
| break; |
| |
| case elfcpp::R_386_GOTOFF: |
| case elfcpp::R_386_GOTPC: |
| // We need a GOT section. |
| target->got_section(symtab, layout); |
| break; |
| |
| case elfcpp::R_386_COPY: |
| case elfcpp::R_386_GLOB_DAT: |
| case elfcpp::R_386_JUMP_SLOT: |
| case elfcpp::R_386_RELATIVE: |
| case elfcpp::R_386_TLS_TPOFF: |
| case elfcpp::R_386_TLS_DTPMOD32: |
| case elfcpp::R_386_TLS_DTPOFF32: |
| case elfcpp::R_386_TLS_TPOFF32: |
| case elfcpp::R_386_TLS_DESC: |
| fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), |
| program_name, object->name().c_str(), r_type); |
| gold_exit(false); |
| break; |
| |
| case elfcpp::R_386_TLS_IE: |
| case elfcpp::R_386_TLS_GOTIE: |
| case elfcpp::R_386_TLS_LE: |
| case elfcpp::R_386_TLS_GD: |
| case elfcpp::R_386_TLS_LDM: |
| case elfcpp::R_386_TLS_LDO_32: |
| case elfcpp::R_386_TLS_IE_32: |
| case elfcpp::R_386_TLS_LE_32: |
| case elfcpp::R_386_TLS_GOTDESC: |
| case elfcpp::R_386_TLS_DESC_CALL: |
| r_type = Target_i386::optimize_tls_reloc(&options, true, r_type); |
| switch (r_type) |
| { |
| case elfcpp::R_386_TLS_LE: |
| case elfcpp::R_386_TLS_LE_32: |
| // FIXME: If generating a shared object, we need to copy |
| // this relocation into the object. |
| break; |
| |
| case elfcpp::R_386_TLS_IE: |
| case elfcpp::R_386_TLS_GOTIE: |
| case elfcpp::R_386_TLS_GD: |
| case elfcpp::R_386_TLS_LDM: |
| case elfcpp::R_386_TLS_LDO_32: |
| case elfcpp::R_386_TLS_IE_32: |
| case elfcpp::R_386_TLS_GOTDESC: |
| case elfcpp::R_386_TLS_DESC_CALL: |
| fprintf(stderr, |
| _("%s: %s: unsupported reloc %u against local symbol\n"), |
| program_name, object->name().c_str(), r_type); |
| break; |
| } |
| break; |
| |
| case elfcpp::R_386_GOT32: |
| case elfcpp::R_386_PLT32: |
| case elfcpp::R_386_32PLT: |
| case elfcpp::R_386_TLS_GD_32: |
| case elfcpp::R_386_TLS_GD_PUSH: |
| case elfcpp::R_386_TLS_GD_CALL: |
| case elfcpp::R_386_TLS_GD_POP: |
| case elfcpp::R_386_TLS_LDM_32: |
| case elfcpp::R_386_TLS_LDM_PUSH: |
| case elfcpp::R_386_TLS_LDM_CALL: |
| case elfcpp::R_386_TLS_LDM_POP: |
| case elfcpp::R_386_USED_BY_INTEL_200: |
| default: |
| fprintf(stderr, _("%s: %s: unsupported reloc %u against local symbol\n"), |
| program_name, object->name().c_str(), r_type); |
| break; |
| } |
| } |
| |
| // Scan a relocation for a global symbol. |
| |
| inline void |
| Target_i386::Scan::global(const General_options& options, |
| Symbol_table* symtab, |
| Layout* layout, |
| Target_i386* target, |
| Sized_relobj<32, false>* object, |
| const elfcpp::Rel<32, false>&, unsigned int r_type, |
| Symbol* gsym) |
| { |
| switch (r_type) |
| { |
| case elfcpp::R_386_NONE: |
| case elfcpp::R_386_GNU_VTINHERIT: |
| case elfcpp::R_386_GNU_VTENTRY: |
| break; |
| |
| case elfcpp::R_386_32: |
| case elfcpp::R_386_PC32: |
| case elfcpp::R_386_16: |
| case elfcpp::R_386_PC16: |
| case elfcpp::R_386_8: |
| case elfcpp::R_386_PC8: |
| // FIXME: If we are generating a shared object we may need to |
| // copy this relocation into the object. If this symbol is |
| // defined in a shared object, we may need to copy this |
| // relocation in order to avoid a COPY relocation. |
| break; |
| |
| case elfcpp::R_386_GOT32: |
| // The symbol requires a GOT entry. |
| if (target->got_section(symtab, layout)->add_global(gsym)) |
| { |
| // If this symbol is not resolved locally, we need to add a |
| // dynamic relocation for it. |
| if (!gsym->is_resolved_locally()) |
| abort(); |
| } |
| break; |
| |
| case elfcpp::R_386_PLT32: |
| // If the symbol is resolved locally, this is just a PC32 reloc. |
| if (gsym->is_resolved_locally()) |
| break; |
| fprintf(stderr, |
| _("%s: %s: unsupported reloc %u against global symbol %s\n"), |
| program_name, object->name().c_str(), r_type, gsym->name()); |
| break; |
| |
| case elfcpp::R_386_GOTOFF: |
| case elfcpp::R_386_GOTPC: |
| // We need a GOT section. |
| target->got_section(symtab, layout); |
| break; |
| |
| case elfcpp::R_386_COPY: |
| case elfcpp::R_386_GLOB_DAT: |
| case elfcpp::R_386_JUMP_SLOT: |
| case elfcpp::R_386_RELATIVE: |
| case elfcpp::R_386_TLS_TPOFF: |
| case elfcpp::R_386_TLS_DTPMOD32: |
| case elfcpp::R_386_TLS_DTPOFF32: |
| case elfcpp::R_386_TLS_TPOFF32: |
| case elfcpp::R_386_TLS_DESC: |
| fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), |
| program_name, object->name().c_str(), r_type); |
| gold_exit(false); |
| break; |
| |
| case elfcpp::R_386_TLS_IE: |
| case elfcpp::R_386_TLS_GOTIE: |
| case elfcpp::R_386_TLS_LE: |
| case elfcpp::R_386_TLS_GD: |
| case elfcpp::R_386_TLS_LDM: |
| case elfcpp::R_386_TLS_LDO_32: |
| case elfcpp::R_386_TLS_IE_32: |
| case elfcpp::R_386_TLS_LE_32: |
| case elfcpp::R_386_TLS_GOTDESC: |
| case elfcpp::R_386_TLS_DESC_CALL: |
| r_type = Target_i386::optimize_tls_reloc(&options, |
| gsym->is_resolved_locally(), |
| r_type); |
| switch (r_type) |
| { |
| case elfcpp::R_386_TLS_LE: |
| case elfcpp::R_386_TLS_LE_32: |
| // FIXME: If generating a shared object, we need to copy |
| // this relocation into the object. |
| break; |
| |
| case elfcpp::R_386_TLS_IE: |
| case elfcpp::R_386_TLS_GOTIE: |
| case elfcpp::R_386_TLS_GD: |
| case elfcpp::R_386_TLS_LDM: |
| case elfcpp::R_386_TLS_LDO_32: |
| case elfcpp::R_386_TLS_IE_32: |
| case elfcpp::R_386_TLS_GOTDESC: |
| case elfcpp::R_386_TLS_DESC_CALL: |
| fprintf(stderr, |
| _("%s: %s: unsupported reloc %u against global symbol %s\n"), |
| program_name, object->name().c_str(), r_type, gsym->name()); |
| break; |
| } |
| break; |
| |
| case elfcpp::R_386_32PLT: |
| case elfcpp::R_386_TLS_GD_32: |
| case elfcpp::R_386_TLS_GD_PUSH: |
| case elfcpp::R_386_TLS_GD_CALL: |
| case elfcpp::R_386_TLS_GD_POP: |
| case elfcpp::R_386_TLS_LDM_32: |
| case elfcpp::R_386_TLS_LDM_PUSH: |
| case elfcpp::R_386_TLS_LDM_CALL: |
| case elfcpp::R_386_TLS_LDM_POP: |
| case elfcpp::R_386_USED_BY_INTEL_200: |
| default: |
| fprintf(stderr, |
| _("%s: %s: unsupported reloc %u against global symbol %s\n"), |
| program_name, object->name().c_str(), r_type, gsym->name()); |
| break; |
| } |
| } |
| |
| // Scan relocations for a section. |
| |
| void |
| Target_i386::scan_relocs(const General_options& options, |
| Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, false>* object, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| size_t local_symbol_count, |
| const unsigned char* plocal_symbols, |
| Symbol** global_symbols) |
| { |
| if (sh_type == elfcpp::SHT_RELA) |
| { |
| fprintf(stderr, _("%s: %s: unsupported RELA reloc section\n"), |
| program_name, object->name().c_str()); |
| gold_exit(false); |
| } |
| |
| gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL, |
| Target_i386::Scan>( |
| options, |
| symtab, |
| layout, |
| this, |
| object, |
| prelocs, |
| reloc_count, |
| local_symbol_count, |
| plocal_symbols, |
| global_symbols); |
| } |
| |
| // Perform a relocation. |
| |
| inline bool |
| Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo, |
| Target_i386* target, |
| size_t relnum, |
| const elfcpp::Rel<32, false>& rel, |
| unsigned int r_type, |
| Sized_symbol<32>* gsym, |
| elfcpp::Elf_types<32>::Elf_Addr value, |
| unsigned char* view, |
| elfcpp::Elf_types<32>::Elf_Addr address, |
| off_t view_size) |
| { |
| if (this->skip_call_tls_get_addr_) |
| { |
| if (r_type != elfcpp::R_386_PLT32 |
| || gsym == NULL |
| || strcmp(gsym->name(), "___tls_get_addr") != 0) |
| { |
| fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str()); |
| gold_exit(false); |
| } |
| |
| this->skip_call_tls_get_addr_ = false; |
| |
| return false; |
| } |
| |
| switch (r_type) |
| { |
| case elfcpp::R_386_NONE: |
| case elfcpp::R_386_GNU_VTINHERIT: |
| case elfcpp::R_386_GNU_VTENTRY: |
| break; |
| |
| case elfcpp::R_386_32: |
| Relocate_functions<32, false>::rel32(view, value); |
| break; |
| |
| case elfcpp::R_386_PC32: |
| Relocate_functions<32, false>::pcrel32(view, value, address); |
| break; |
| |
| case elfcpp::R_386_16: |
| Relocate_functions<32, false>::rel16(view, value); |
| break; |
| |
| case elfcpp::R_386_PC16: |
| Relocate_functions<32, false>::pcrel16(view, value, address); |
| break; |
| |
| case elfcpp::R_386_8: |
| Relocate_functions<32, false>::rel8(view, value); |
| break; |
| |
| case elfcpp::R_386_PC8: |
| Relocate_functions<32, false>::pcrel8(view, value, address); |
| break; |
| |
| case elfcpp::R_386_PLT32: |
| if (gsym->is_resolved_locally()) |
| Relocate_functions<32, false>::pcrel32(view, value, address); |
| else |
| fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str(), |
| r_type); |
| break; |
| |
| case elfcpp::R_386_GOT32: |
| // Local GOT offsets not yet supported. |
| assert(gsym); |
| assert(gsym->has_got_offset()); |
| value = gsym->got_offset(); |
| Relocate_functions<32, false>::rel32(view, value); |
| break; |
| |
| case elfcpp::R_386_GOTOFF: |
| value -= target->got_section(NULL, NULL)->address(); |
| Relocate_functions<32, false>::rel32(view, value); |
| break; |
| |
| case elfcpp::R_386_GOTPC: |
| value = target->got_section(NULL, NULL)->address(); |
| Relocate_functions<32, false>::pcrel32(view, value, address); |
| break; |
| |
| case elfcpp::R_386_COPY: |
| case elfcpp::R_386_GLOB_DAT: |
| case elfcpp::R_386_JUMP_SLOT: |
| case elfcpp::R_386_RELATIVE: |
| case elfcpp::R_386_TLS_TPOFF: |
| case elfcpp::R_386_TLS_DTPMOD32: |
| case elfcpp::R_386_TLS_DTPOFF32: |
| case elfcpp::R_386_TLS_TPOFF32: |
| case elfcpp::R_386_TLS_DESC: |
| fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str(), |
| r_type); |
| gold_exit(false); |
| break; |
| |
| case elfcpp::R_386_TLS_IE: |
| case elfcpp::R_386_TLS_GOTIE: |
| case elfcpp::R_386_TLS_LE: |
| case elfcpp::R_386_TLS_GD: |
| case elfcpp::R_386_TLS_LDM: |
| case elfcpp::R_386_TLS_LDO_32: |
| case elfcpp::R_386_TLS_IE_32: |
| case elfcpp::R_386_TLS_LE_32: |
| case elfcpp::R_386_TLS_GOTDESC: |
| case elfcpp::R_386_TLS_DESC_CALL: |
| this->relocate_tls(relinfo, relnum, rel, r_type, gsym, value, view, |
| address, view_size); |
| break; |
| |
| case elfcpp::R_386_32PLT: |
| case elfcpp::R_386_TLS_GD_32: |
| case elfcpp::R_386_TLS_GD_PUSH: |
| case elfcpp::R_386_TLS_GD_CALL: |
| case elfcpp::R_386_TLS_GD_POP: |
| case elfcpp::R_386_TLS_LDM_32: |
| case elfcpp::R_386_TLS_LDM_PUSH: |
| case elfcpp::R_386_TLS_LDM_CALL: |
| case elfcpp::R_386_TLS_LDM_POP: |
| case elfcpp::R_386_USED_BY_INTEL_200: |
| default: |
| fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str(), |
| r_type); |
| // gold_exit(false); |
| break; |
| } |
| |
| return true; |
| } |
| |
| // Perform a TLS relocation. |
| |
| inline void |
| Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo, |
| size_t relnum, |
| const elfcpp::Rel<32, false>& rel, |
| unsigned int r_type, |
| Sized_symbol<32>* gsym, |
| elfcpp::Elf_types<32>::Elf_Addr value, |
| unsigned char* view, |
| elfcpp::Elf_types<32>::Elf_Addr, |
| off_t view_size) |
| { |
| Output_segment* tls_segment = relinfo->layout->tls_segment(); |
| if (tls_segment == NULL) |
| { |
| fprintf(stderr, _("%s: %s: TLS reloc but no TLS segment\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str()); |
| gold_exit(false); |
| } |
| |
| const bool is_local = gsym == NULL || gsym->is_resolved_locally(); |
| const unsigned int opt_r_type = |
| Target_i386::optimize_tls_reloc(relinfo->options, is_local, r_type); |
| switch (r_type) |
| { |
| case elfcpp::R_386_TLS_LE_32: |
| value = tls_segment->vaddr() + tls_segment->memsz() - value; |
| Relocate_functions<32, false>::rel32(view, value); |
| break; |
| |
| case elfcpp::R_386_TLS_LE: |
| value = value - (tls_segment->vaddr() + tls_segment->memsz()); |
| Relocate_functions<32, false>::rel32(view, value); |
| break; |
| |
| case elfcpp::R_386_TLS_IE: |
| case elfcpp::R_386_TLS_GOTIE: |
| case elfcpp::R_386_TLS_IE_32: |
| if (opt_r_type == elfcpp::R_386_TLS_LE_32) |
| { |
| Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, |
| rel, r_type, value, view, |
| view_size); |
| break; |
| } |
| fprintf(stderr, _("%s: %s: unsupported reloc type %u\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str(), |
| r_type); |
| // gold_exit(false); |
| break; |
| |
| case elfcpp::R_386_TLS_GD: |
| if (opt_r_type == elfcpp::R_386_TLS_LE_32) |
| { |
| this->tls_gd_to_le(relinfo, relnum, tls_segment, |
| rel, r_type, value, view, |
| view_size); |
| break; |
| } |
| fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str(), |
| r_type); |
| // gold_exit(false); |
| break; |
| |
| case elfcpp::R_386_TLS_LDM: |
| case elfcpp::R_386_TLS_LDO_32: |
| case elfcpp::R_386_TLS_GOTDESC: |
| case elfcpp::R_386_TLS_DESC_CALL: |
| fprintf(stderr, _("%s: %s: unsupported reloc %u\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str(), |
| r_type); |
| // gold_exit(false); |
| break; |
| } |
| } |
| |
| // Do a relocation in which we convert a TLS Initial-Exec to a |
| // Local-Exec. |
| |
| inline void |
| Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo, |
| size_t relnum, |
| Output_segment* tls_segment, |
| const elfcpp::Rel<32, false>& rel, |
| unsigned int r_type, |
| elfcpp::Elf_types<32>::Elf_Addr value, |
| unsigned char* view, |
| off_t view_size) |
| { |
| // We have to actually change the instructions, which means that we |
| // need to examine the opcodes to figure out which instruction we |
| // are looking at. |
| if (r_type == elfcpp::R_386_TLS_IE) |
| { |
| // movl %gs:XX,%eax ==> movl $YY,%eax |
| // movl %gs:XX,%reg ==> movl $YY,%reg |
| // addl %gs:XX,%reg ==> addl $YY,%reg |
| Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -1); |
| Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4); |
| |
| unsigned char op1 = view[-1]; |
| if (op1 == 0xa1) |
| { |
| // movl XX,%eax ==> movl $YY,%eax |
| view[-1] = 0xb8; |
| } |
| else |
| { |
| Target_i386::Relocate::check_range(relinfo, relnum, rel, |
| view_size, -2); |
| |
| unsigned char op2 = view[-2]; |
| if (op2 == 0x8b) |
| { |
| // movl XX,%reg ==> movl $YY,%reg |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, |
| (op1 & 0xc7) == 0x05); |
| view[-2] = 0xc7; |
| view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| } |
| else if (op2 == 0x03) |
| { |
| // addl XX,%reg ==> addl $YY,%reg |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, |
| (op1 & 0xc7) == 0x05); |
| view[-2] = 0x81; |
| view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| } |
| else |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0); |
| } |
| } |
| else |
| { |
| // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 |
| // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 |
| // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 |
| Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2); |
| Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 4); |
| |
| unsigned char op1 = view[-1]; |
| unsigned char op2 = view[-2]; |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, |
| (op1 & 0xc0) == 0x80 && (op1 & 7) != 4); |
| if (op2 == 0x8b) |
| { |
| // movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2 |
| view[-2] = 0xc7; |
| view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| } |
| else if (op2 == 0x2b) |
| { |
| // subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2 |
| view[-2] = 0x81; |
| view[-1] = 0xe8 | ((op1 >> 3) & 7); |
| } |
| else if (op2 == 0x03) |
| { |
| // addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2 |
| view[-2] = 0x81; |
| view[-1] = 0xc0 | ((op1 >> 3) & 7); |
| } |
| else |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, 0); |
| } |
| |
| value = tls_segment->vaddr() + tls_segment->memsz() - value; |
| if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE) |
| value = - value; |
| |
| Relocate_functions<32, false>::rel32(view, value); |
| } |
| |
| // Do a relocation in which we convert a TLS Global-Dynamic to a |
| // Local-Exec. |
| |
| inline void |
| Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo, |
| size_t relnum, |
| Output_segment* tls_segment, |
| const elfcpp::Rel<32, false>& rel, |
| unsigned int, |
| elfcpp::Elf_types<32>::Elf_Addr value, |
| unsigned char* view, |
| off_t view_size) |
| { |
| // leal foo(,%reg,1),%eax; call ___tls_get_addr |
| // ==> movl %gs,0,%eax; subl $foo@tpoff,%eax |
| // leal foo(%reg),%eax; call ___tls_get_addr |
| // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax |
| |
| Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -2); |
| Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, 9); |
| |
| unsigned char op1 = view[-1]; |
| unsigned char op2 = view[-2]; |
| |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, |
| op2 == 0x8d || op2 == 0x04); |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, |
| view[4] == 0xe8); |
| |
| int roff = 5; |
| |
| if (op2 == 0x04) |
| { |
| Target_i386::Relocate::check_range(relinfo, relnum, rel, view_size, -3); |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, |
| view[-3] == 0x8d); |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, |
| ((op1 & 0xc7) == 0x05 |
| && op1 != (4 << 3))); |
| memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
| } |
| else |
| { |
| Target_i386::Relocate::check_tls(relinfo, relnum, rel, |
| (op1 & 0xf8) == 0x80 && (op1 & 7) != 4); |
| if (rel.get_r_offset() + 9 < view_size && view[9] == 0x90) |
| { |
| // There is a trailing nop. Use the size byte subl. |
| memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12); |
| roff = 6; |
| } |
| else |
| { |
| // Use the five byte subl. |
| memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11); |
| } |
| } |
| |
| value = tls_segment->vaddr() + tls_segment->memsz() - value; |
| Relocate_functions<32, false>::rel32(view + roff, value); |
| |
| // The next reloc should be a PLT32 reloc against __tls_get_addr. |
| // We can skip it. |
| this->skip_call_tls_get_addr_ = true; |
| } |
| |
| // Check the range for a TLS relocation. |
| |
| inline void |
| Target_i386::Relocate::check_range(const Relocate_info<32, false>* relinfo, |
| size_t relnum, |
| const elfcpp::Rel<32, false>& rel, |
| off_t view_size, off_t off) |
| { |
| off_t offset = rel.get_r_offset() + off; |
| if (offset < 0 || offset > view_size) |
| { |
| fprintf(stderr, _("%s: %s: TLS relocation out of range\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str()); |
| gold_exit(false); |
| } |
| } |
| |
| // Check the validity of a TLS relocation. This is like assert. |
| |
| inline void |
| Target_i386::Relocate::check_tls(const Relocate_info<32, false>* relinfo, |
| size_t relnum, |
| const elfcpp::Rel<32, false>& rel, |
| bool valid) |
| { |
| if (!valid) |
| { |
| fprintf(stderr, |
| _("%s: %s: TLS relocation against invalid instruction\n"), |
| program_name, |
| relinfo->location(relnum, rel.get_r_offset()).c_str()); |
| gold_exit(false); |
| } |
| } |
| |
| // Relocate section data. |
| |
| void |
| Target_i386::relocate_section(const Relocate_info<32, false>* relinfo, |
| unsigned int sh_type, |
| const unsigned char* prelocs, |
| size_t reloc_count, |
| unsigned char* view, |
| elfcpp::Elf_types<32>::Elf_Addr address, |
| off_t view_size) |
| { |
| assert(sh_type == elfcpp::SHT_REL); |
| |
| gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL, |
| Target_i386::Relocate>( |
| relinfo, |
| this, |
| prelocs, |
| reloc_count, |
| view, |
| address, |
| view_size); |
| } |
| |
| // The selector for i386 object files. |
| |
| class Target_selector_i386 : public Target_selector |
| { |
| public: |
| Target_selector_i386() |
| : Target_selector(elfcpp::EM_386, 32, false) |
| { } |
| |
| Target* |
| recognize(int machine, int osabi, int abiversion); |
| |
| private: |
| Target_i386* target_; |
| }; |
| |
| // Recognize an i386 object file when we already know that the machine |
| // number is EM_386. |
| |
| Target* |
| Target_selector_i386::recognize(int, int, int) |
| { |
| if (this->target_ == NULL) |
| this->target_ = new Target_i386(); |
| return this->target_; |
| } |
| |
| Target_selector_i386 target_selector_i386; |
| |
| } // End anonymous namespace. |