| // 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; |
| |
| class Output_data_plt_i386; |
| |
| // The i386 target class. |
| |
| class Target_i386 : public Sized_target<32, false> |
| { |
| public: |
| typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
| |
| Target_i386() |
| : Sized_target<32, false>(&i386_info), |
| got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL), |
| copy_relocs_(NULL), dynbss_(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 data_shndx, |
| 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); |
| |
| // Finalize the sections. |
| void |
| do_finalize_sections(const General_options*, Layout*); |
| |
| // 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, |
| unsigned int data_shndx, |
| 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, |
| unsigned int data_shndx, |
| 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, const 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, const 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_final, int r_type); |
| |
| // Get the GOT section, creating it if necessary. |
| Output_data_got<32, false>* |
| got_section(const General_options*, Symbol_table*, Layout*); |
| |
| // Create a PLT entry for a global symbol. |
| void |
| make_plt_entry(const General_options* options, Symbol_table*, |
| Layout*, Symbol*); |
| |
| // Get the PLT section. |
| Output_data_plt_i386* |
| 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*); |
| |
| // Copy a relocation against a global symbol. |
| void |
| copy_reloc(const General_options*, Symbol_table*, Layout*, |
| Sized_relobj<32, false>*, unsigned int, |
| Symbol*, const elfcpp::Rel<32, false>&); |
| |
| // 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_; |
| // The PLT section. |
| Output_data_plt_i386* 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<32, false>* copy_relocs_; |
| // Space for variables copied with a COPY reloc. |
| Output_data_space* dynbss_; |
| }; |
| |
| 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(const General_options* options, Symbol_table* symtab, |
| Layout* layout) |
| { |
| if (this->got_ == NULL) |
| { |
| gold_assert(options != NULL && symtab != NULL && layout != NULL); |
| |
| this->got_ = new Output_data_got<32, false>(options); |
| |
| layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
| this->got_); |
| |
| // 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); |
| layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, |
| elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, |
| this->got_plt_); |
| |
| // The first three entries are reserved. |
| this->got_plt_->set_space_size(3 * 4); |
| |
| // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. |
| symtab->define_in_output_data(this, "_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. |
| |
| Target_i386::Reloc_section* |
| Target_i386::rel_dyn_section(Layout* layout) |
| { |
| if (this->rel_dyn_ == NULL) |
| { |
| gold_assert(layout != NULL); |
| this->rel_dyn_ = new Reloc_section(); |
| layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL, |
| elfcpp::SHF_ALLOC, this->rel_dyn_); |
| } |
| return this->rel_dyn_; |
| } |
| |
| // A class to handle the PLT data. |
| |
| class Output_data_plt_i386 : public Output_section_data |
| { |
| public: |
| typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section; |
| |
| Output_data_plt_i386(Layout*, Output_data_space*, bool is_shared); |
| |
| // 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); |
| |
| private: |
| // The size of an entry in the PLT. |
| static const int plt_entry_size = 16; |
| |
| // The first entry in the PLT for an executable. |
| static unsigned char exec_first_plt_entry[plt_entry_size]; |
| |
| // The first entry in the PLT for a shared object. |
| static unsigned char dyn_first_plt_entry[plt_entry_size]; |
| |
| // Other entries in the PLT for an executable. |
| static unsigned char exec_plt_entry[plt_entry_size]; |
| |
| // Other entries in the PLT for a shared object. |
| static unsigned char dyn_plt_entry[plt_entry_size]; |
| |
| // Set the final size. |
| void |
| do_set_address(uint64_t, off_t) |
| { this->set_data_size((this->count_ + 1) * plt_entry_size); } |
| |
| // 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_; |
| // Whether we are generated a shared object. |
| bool is_shared_; |
| }; |
| |
| // 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. |
| |
| Output_data_plt_i386::Output_data_plt_i386(Layout* layout, |
| Output_data_space* got_plt, |
| bool is_shared) |
| : Output_section_data(4), got_plt_(got_plt), is_shared_(is_shared) |
| { |
| this->rel_ = new Reloc_section(); |
| layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL, |
| elfcpp::SHF_ALLOC, this->rel_); |
| } |
| |
| // For some reason |
| |
| void |
| Output_data_plt_i386::do_adjust_output_section(Output_section* os) |
| { |
| // UnixWare sets the entsize of .plt to 4, and so does the old GNU |
| // linker, and so do we. |
| os->set_entsize(4); |
| } |
| |
| // Add an entry to the PLT. |
| |
| void |
| Output_data_plt_i386::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_ + 1) * plt_entry_size); |
| |
| ++this->count_; |
| |
| off_t got_offset = this->got_plt_->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_space_size(got_offset + 4); |
| |
| // Every PLT entry needs a reloc. |
| gsym->set_needs_dynsym_entry(); |
| this->rel_->add_global(gsym, elfcpp::R_386_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. |
| } |
| |
| // The first entry in the PLT for an executable. |
| |
| unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] = |
| { |
| 0xff, 0x35, // pushl contents of memory address |
| 0, 0, 0, 0, // replaced with address of .got + 4 |
| 0xff, 0x25, // jmp indirect |
| 0, 0, 0, 0, // replaced with address of .got + 8 |
| 0, 0, 0, 0 // unused |
| }; |
| |
| // The first entry in the PLT for a shared object. |
| |
| unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] = |
| { |
| 0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx) |
| 0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx) |
| 0, 0, 0, 0 // unused |
| }; |
| |
| // Subsequent entries in the PLT for an executable. |
| |
| unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] = |
| { |
| 0xff, 0x25, // jmp indirect |
| 0, 0, 0, 0, // replaced with address of symbol in .got |
| 0x68, // pushl immediate |
| 0, 0, 0, 0, // replaced with offset into relocation table |
| 0xe9, // jmp relative |
| 0, 0, 0, 0 // replaced with offset to start of .plt |
| }; |
| |
| // Subsequent entries in the PLT for a shared object. |
| |
| unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] = |
| { |
| 0xff, 0xa3, // jmp *offset(%ebx) |
| 0, 0, 0, 0, // replaced with offset of symbol in .got |
| 0x68, // pushl immediate |
| 0, 0, 0, 0, // replaced with offset into relocation table |
| 0xe9, // jmp relative |
| 0, 0, 0, 0 // replaced with offset to start of .plt |
| }; |
| |
| // Write out the PLT. This uses the hand-coded instructions above, |
| // and adjusts them as needed. This is all specified by the i386 ELF |
| // Processor Supplement. |
| |
| void |
| Output_data_plt_i386::do_write(Output_file* of) |
| { |
| const off_t offset = this->offset(); |
| const off_t oview_size = 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 off_t got_size = this->got_plt_->data_size(); |
| unsigned char* const got_view = of->get_output_view(got_file_offset, |
| got_size); |
| |
| unsigned char* pov = oview; |
| |
| elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address(); |
| elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address(); |
| |
| if (this->is_shared_) |
| memcpy(pov, dyn_first_plt_entry, plt_entry_size); |
| else |
| { |
| memcpy(pov, exec_first_plt_entry, plt_entry_size); |
| elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4); |
| elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8); |
| } |
| pov += plt_entry_size; |
| |
| 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 = plt_entry_size; |
| 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 += plt_entry_size, |
| got_pov += 4, |
| plt_offset += plt_entry_size, |
| plt_rel_offset += rel_size, |
| got_offset += 4) |
| { |
| // Set and adjust the PLT entry itself. |
| |
| if (this->is_shared_) |
| { |
| memcpy(pov, dyn_plt_entry, plt_entry_size); |
| elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); |
| } |
| else |
| { |
| memcpy(pov, exec_plt_entry, plt_entry_size); |
| elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, |
| (got_address |
| + got_offset)); |
| } |
| |
| elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset); |
| elfcpp::Swap<32, false>::writeval(pov + 12, |
| - (plt_offset + plt_entry_size)); |
| |
| // Set the entry in the GOT. |
| elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6); |
| } |
| |
| gold_assert(pov - oview == oview_size); |
| gold_assert(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. |
| |
| void |
| Target_i386::make_plt_entry(const General_options* options, |
| 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(options, symtab, layout); |
| |
| this->plt_ = new Output_data_plt_i386(layout, this->got_plt_, |
| options->is_shared()); |
| layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, |
| (elfcpp::SHF_ALLOC |
| | elfcpp::SHF_EXECINSTR), |
| this->plt_); |
| } |
| |
| this->plt_->add_entry(gsym); |
| } |
| |
| // Handle a relocation against a non-function symbol defined in a |
| // dynamic object. The traditional way to handle this is to generate |
| // a COPY relocation to copy the variable at runtime from the shared |
| // object into the executable's data segment. However, this is |
| // undesirable in general, as if the size of the object changes in the |
| // dynamic object, the executable will no longer work correctly. If |
| // this relocation is in a writable section, then we can create a |
| // dynamic reloc and the dynamic linker will resolve it to the correct |
| // address at runtime. However, we do not want do that if the |
| // relocation is in a read-only section, as it would prevent the |
| // readonly segment from being shared. And if we have to eventually |
| // generate a COPY reloc, then any dynamic relocations will be |
| // useless. So this means that if this is a writable section, we need |
| // to save the relocation until we see whether we have to create a |
| // COPY relocation for this symbol for any other relocation. |
| |
| void |
| Target_i386::copy_reloc(const General_options* options, |
| Symbol_table* symtab, |
| Layout* layout, |
| Sized_relobj<32, false>* object, |
| unsigned int data_shndx, Symbol* gsym, |
| const elfcpp::Rel<32, false>& rel) |
| { |
| Sized_symbol<32>* ssym; |
| ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(32) (gsym |
| SELECT_SIZE(32)); |
| |
| if (!Copy_relocs<32, false>::need_copy_reloc(options, object, |
| data_shndx, ssym)) |
| { |
| // So far we do not need a COPY reloc. Save this relocation. |
| // If it turns out that we never need a COPY reloc for this |
| // symbol, then we will emit the relocation. |
| if (this->copy_relocs_ == NULL) |
| this->copy_relocs_ = new Copy_relocs<32, false>(); |
| this->copy_relocs_->save(ssym, object, data_shndx, rel); |
| } |
| else |
| { |
| // Allocate space for this symbol in the .bss section. |
| |
| elfcpp::Elf_types<32>::Elf_WXword symsize = ssym->symsize(); |
| |
| // There is no defined way to determine the required alignment |
| // of the symbol. We pick the alignment based on the size. We |
| // set an arbitrary maximum of 256. |
| unsigned int align; |
| for (align = 1; align < 512; align <<= 1) |
| if ((symsize & align) != 0) |
| break; |
| |
| if (this->dynbss_ == NULL) |
| { |
| this->dynbss_ = new Output_data_space(align); |
| layout->add_output_section_data(".bss", |
| elfcpp::SHT_NOBITS, |
| (elfcpp::SHF_ALLOC |
| | elfcpp::SHF_WRITE), |
| this->dynbss_); |
| } |
| |
| Output_data_space* dynbss = this->dynbss_; |
| |
| if (align > dynbss->addralign()) |
| dynbss->set_space_alignment(align); |
| |
| off_t dynbss_size = dynbss->data_size(); |
| dynbss_size = align_address(dynbss_size, align); |
| off_t offset = dynbss_size; |
| dynbss->set_space_size(dynbss_size + symsize); |
| |
| // Define the symbol in the .dynbss section. |
| symtab->define_in_output_data(this, ssym->name(), ssym->version(), |
| dynbss, offset, symsize, ssym->type(), |
| ssym->binding(), ssym->visibility(), |
| ssym->nonvis(), false, false); |
| |
| // Add the COPY reloc. |
| ssym->set_needs_dynsym_entry(); |
| Reloc_section* rel_dyn = this->rel_dyn_section(layout); |
| rel_dyn->add_global(ssym, elfcpp::R_386_COPY, dynbss, offset); |
| } |
| } |
| |
| // Optimize the TLS relocation type based on what we know about the |
| // symbol. IS_FINAL is true if the final address of this symbol is |
| // known at link time. |
| |
| unsigned int |
| Target_i386::optimize_tls_reloc(const General_options* options, |
| bool is_final, |
| 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_final) |
| 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_final) |
| 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: |
| gold_unreachable(); |
| } |
| } |
| |
| // 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, |
| unsigned int, |
| 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. |
| gold_assert(!options.is_shared()); |
| 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(&options, 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, |
| !options.is_shared(), |
| 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. |
| gold_assert(!options.is_shared()); |
| 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, |
| unsigned int data_shndx, |
| const elfcpp::Rel<32, false>& reloc, |
| 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. |
| gold_assert(!options.is_shared()); |
| |
| if (gsym->is_from_dynobj()) |
| { |
| // This symbol is defined in a dynamic object. If it is a |
| // function, we make a PLT entry. Otherwise we need to |
| // either generate a COPY reloc or copy this reloc. |
| if (gsym->type() == elfcpp::STT_FUNC) |
| target->make_plt_entry(&options, symtab, layout, gsym); |
| else |
| target->copy_reloc(&options, symtab, layout, object, data_shndx, |
| gsym, reloc); |
| } |
| |
| break; |
| |
| case elfcpp::R_386_GOT32: |
| // The symbol requires a GOT entry. |
| if (target->got_section(&options, symtab, layout)->add_global(gsym)) |
| { |
| // If this symbol is not fully resolved, we need to add a |
| // dynamic relocation for it. |
| if (!gsym->final_value_is_known(&options)) |
| gold_unreachable(); |
| } |
| break; |
| |
| case elfcpp::R_386_PLT32: |
| // If the symbol is fully resolved, this is just a PC32 reloc. |
| // Otherwise we need a PLT entry. |
| if (gsym->final_value_is_known(&options)) |
| break; |
| target->make_plt_entry(&options, symtab, layout, gsym); |
| break; |
| |
| case elfcpp::R_386_GOTOFF: |
| case elfcpp::R_386_GOTPC: |
| // We need a GOT section. |
| target->got_section(&options, 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: |
| { |
| const bool is_final = gsym->final_value_is_known(&options); |
| r_type = Target_i386::optimize_tls_reloc(&options, is_final, 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. |
| gold_assert(!options.is_shared()); |
| 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 data_shndx, |
| 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, |
| data_shndx, |
| prelocs, |
| reloc_count, |
| local_symbol_count, |
| plocal_symbols, |
| global_symbols); |
| } |
| |
| // Finalize the sections. |
| |
| void |
| Target_i386::do_finalize_sections(const General_options* options, |
| Layout* layout) |
| { |
| // Fill in some more dynamic tags. |
| Output_data_dynamic* const odyn = layout->dynamic_data(); |
| if (odyn != NULL) |
| { |
| if (this->got_plt_ != NULL) |
| odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_); |
| |
| if (this->plt_ != 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) |
| { |
| 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 (!options->is_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_ == NULL) |
| return; |
| if (this->copy_relocs_->any_to_emit()) |
| { |
| Reloc_section* rel_dyn = this->rel_dyn_section(layout); |
| this->copy_relocs_->emit(rel_dyn); |
| } |
| delete this->copy_relocs_; |
| this->copy_relocs_ = NULL; |
| } |
| |
| // 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, |
| const 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; |
| } |
| |
| // Pick the value to use for symbols defined in shared objects. |
| if (gsym != NULL && gsym->is_from_dynobj()) |
| { |
| if (gsym->has_plt_offset()) |
| value = target->plt_section()->address() + gsym->plt_offset(); |
| else |
| gold_unreachable(); |
| } |
| |
| 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: |
| gold_assert(gsym->has_plt_offset() |
| || gsym->final_value_is_known(relinfo->options)); |
| Relocate_functions<32, false>::pcrel32(view, value, address); |
| break; |
| |
| case elfcpp::R_386_GOT32: |
| // Local GOT offsets not yet supported. |
| gold_assert(gsym); |
| gold_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, NULL)->address(); |
| Relocate_functions<32, false>::rel32(view, value); |
| break; |
| |
| case elfcpp::R_386_GOTPC: |
| value = target->got_section(NULL, 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, |
| const 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_final = (gsym == NULL |
| ? !relinfo->options->is_shared() |
| : gsym->final_value_is_known(relinfo->options)); |
| const unsigned int opt_r_type = |
| Target_i386::optimize_tls_reloc(relinfo->options, is_final, 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) |
| { |
| gold_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. |