X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gold%2Fx86_64.cc;h=22d5cc697e3b89f8df9afa940cf96d20aaa89b4f;hb=dddc0e16ef5d77e4f97d02ee0e2d4234c97dae0e;hp=cb687302f95331d0c4f2f6f7ffa7a30d546249fd;hpb=78d911fd3eb0d9f7ed7ab9dcf24f97c58278db4a;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/x86_64.cc b/gold/x86_64.cc index cb687302f9..3651d398ff 100644 --- a/gold/x86_64.cc +++ b/gold/x86_64.cc @@ -1,39 +1,31 @@ // x86_64.cc -- x86_64 target support for gold. -// Copyright 2006, 2007, Free Software Foundation, Inc. +// Copyright (C) 2006-2015 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // 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 Library General Public License -// as published by the Free Software Foundation; either version 2, or +// 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. -// In addition to the permissions in the GNU Library General Public -// License, the Free Software Foundation gives you unlimited -// permission to link the compiled version of this file into -// combinations with other programs, and to distribute those -// combinations without any restriction coming from the use of this -// file. (The Library Public License restrictions do apply in other -// respects; for example, they cover modification of the file, and -/// distribution when not linked into a combined executable.) - -// 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 -// Library General Public License for more details. - -// You should have received a copy of the GNU Library 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. +// 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 #include "elfcpp.h" +#include "dwarf.h" #include "parameters.h" #include "reloc.h" #include "x86_64.h" @@ -41,17 +33,375 @@ #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 "freebsd.h" +#include "nacl.h" +#include "gc.h" +#include "icf.h" namespace { using namespace gold; -class Output_data_plt_x86_64; +// A class to handle the .got.plt section. + +class Output_data_got_plt_x86_64 : public Output_section_data_build +{ + public: + Output_data_got_plt_x86_64(Layout* layout) + : Output_section_data_build(8), + layout_(layout) + { } + + Output_data_got_plt_x86_64(Layout* layout, off_t data_size) + : Output_section_data_build(data_size, 8), + layout_(layout) + { } + + protected: + // Write out the PLT data. + void + do_write(Output_file*); + + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, "** GOT PLT"); } + + private: + // A pointer to the Layout class, so that we can find the .dynamic + // section when we write out the GOT PLT section. + Layout* layout_; +}; + +// A class to handle the PLT data. +// This is an abstract base class that handles most of the linker details +// but does not know the actual contents of PLT entries. The derived +// classes below fill in those details. + +template +class Output_data_plt_x86_64 : public Output_section_data +{ + public: + typedef Output_data_reloc Reloc_section; + + Output_data_plt_x86_64(Layout* layout, uint64_t addralign, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative) + : Output_section_data(addralign), tlsdesc_rel_(NULL), + irelative_rel_(NULL), got_(got), got_plt_(got_plt), + got_irelative_(got_irelative), count_(0), irelative_count_(0), + tlsdesc_got_offset_(-1U), free_list_() + { this->init(layout); } + + Output_data_plt_x86_64(Layout* layout, uint64_t plt_entry_size, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative, + unsigned int plt_count) + : Output_section_data((plt_count + 1) * plt_entry_size, + plt_entry_size, false), + tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got), + got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count), + irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_() + { + this->init(layout); + + // Initialize the free list and reserve the first entry. + this->free_list_.init((plt_count + 1) * plt_entry_size, false); + this->free_list_.remove(0, plt_entry_size); + } + + // Initialize the PLT section. + void + init(Layout* layout); + + // Add an entry to the PLT. + void + add_entry(Symbol_table*, Layout*, Symbol* gsym); + + // Add an entry to the PLT for a local STT_GNU_IFUNC symbol. + unsigned int + add_local_ifunc_entry(Symbol_table* symtab, Layout*, + Sized_relobj_file* relobj, + unsigned int local_sym_index); + + // Add the relocation for a PLT entry. + void + add_relocation(Symbol_table*, Layout*, Symbol* gsym, + unsigned int got_offset); + + // Add the reserved TLSDESC_PLT entry to the PLT. + void + reserve_tlsdesc_entry(unsigned int got_offset) + { this->tlsdesc_got_offset_ = got_offset; } + + // Return true if a TLSDESC_PLT entry has been reserved. + bool + has_tlsdesc_entry() const + { return this->tlsdesc_got_offset_ != -1U; } + + // Return the GOT offset for the reserved TLSDESC_PLT entry. + unsigned int + get_tlsdesc_got_offset() const + { return this->tlsdesc_got_offset_; } + + // Return the offset of the reserved TLSDESC_PLT entry. + unsigned int + get_tlsdesc_plt_offset() const + { + return ((this->count_ + this->irelative_count_ + 1) + * this->get_plt_entry_size()); + } + + // Return the .rela.plt section data. + Reloc_section* + rela_plt() + { return this->rel_; } + + // Return where the TLSDESC relocations should go. + Reloc_section* + rela_tlsdesc(Layout*); + + // Return where the IRELATIVE relocations should go in the PLT + // relocations. + Reloc_section* + rela_irelative(Symbol_table*, Layout*); + + // Return whether we created a section for IRELATIVE relocations. + bool + has_irelative_section() const + { return this->irelative_rel_ != NULL; } + + // Return the number of PLT entries. + unsigned int + entry_count() const + { return this->count_ + this->irelative_count_; } + + // Return the offset of the first non-reserved PLT entry. + unsigned int + first_plt_entry_offset() + { return this->get_plt_entry_size(); } + + // Return the size of a PLT entry. + unsigned int + get_plt_entry_size() const + { return this->do_get_plt_entry_size(); } + + // Reserve a slot in the PLT for an existing symbol in an incremental update. + void + reserve_slot(unsigned int plt_index) + { + this->free_list_.remove((plt_index + 1) * this->get_plt_entry_size(), + (plt_index + 2) * this->get_plt_entry_size()); + } + + // Return the PLT address to use for a global symbol. + uint64_t + address_for_global(const Symbol*); + + // Return the PLT address to use for a local symbol. + uint64_t + address_for_local(const Relobj*, unsigned int symndx); + + // Add .eh_frame information for the PLT. + void + add_eh_frame(Layout* layout) + { this->do_add_eh_frame(layout); } + + protected: + // Fill in the first PLT entry. + void + fill_first_plt_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address) + { this->do_fill_first_plt_entry(pov, got_address, plt_address); } + + // Fill in a normal PLT entry. Returns the offset into the entry that + // should be the initial GOT slot value. + unsigned int + fill_plt_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + unsigned int got_offset, + unsigned int plt_offset, + unsigned int plt_index) + { + return this->do_fill_plt_entry(pov, got_address, plt_address, + got_offset, plt_offset, plt_index); + } + + // Fill in the reserved TLSDESC PLT entry. + void + fill_tlsdesc_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + typename elfcpp::Elf_types::Elf_Addr got_base, + unsigned int tlsdesc_got_offset, + unsigned int plt_offset) + { + this->do_fill_tlsdesc_entry(pov, got_address, plt_address, got_base, + tlsdesc_got_offset, plt_offset); + } + + virtual unsigned int + do_get_plt_entry_size() const = 0; + + virtual void + do_fill_first_plt_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_addr, + typename elfcpp::Elf_types::Elf_Addr plt_addr) + = 0; + + virtual unsigned int + do_fill_plt_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + unsigned int got_offset, + unsigned int plt_offset, + unsigned int plt_index) = 0; + + virtual void + do_fill_tlsdesc_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + typename elfcpp::Elf_types::Elf_Addr got_base, + unsigned int tlsdesc_got_offset, + unsigned int plt_offset) = 0; + + virtual void + do_add_eh_frame(Layout* layout) = 0; + + 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")); } + + // The CIE of the .eh_frame unwind information for the PLT. + static const int plt_eh_frame_cie_size = 16; + static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size]; + + private: + // Set the final size. + void + set_final_data_size(); + + // Write out the PLT data. + void + do_write(Output_file*); + + // The reloc section. + Reloc_section* rel_; + // The TLSDESC relocs, if necessary. These must follow the regular + // PLT relocs. + Reloc_section* tlsdesc_rel_; + // The IRELATIVE relocs, if necessary. These must follow the + // regular PLT relocations and the TLSDESC relocations. + Reloc_section* irelative_rel_; + // The .got section. + Output_data_got<64, false>* got_; + // The .got.plt section. + Output_data_got_plt_x86_64* got_plt_; + // The part of the .got.plt section used for IRELATIVE relocs. + Output_data_space* got_irelative_; + // The number of PLT entries. + unsigned int count_; + // Number of PLT entries with R_X86_64_IRELATIVE relocs. These + // follow the regular PLT entries. + unsigned int irelative_count_; + // Offset of the reserved TLSDESC_GOT entry when needed. + unsigned int tlsdesc_got_offset_; + // List of available regions within the section, for incremental + // update links. + Free_list free_list_; +}; + +template +class Output_data_plt_x86_64_standard : public Output_data_plt_x86_64 +{ + public: + Output_data_plt_x86_64_standard(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative) + : Output_data_plt_x86_64(layout, plt_entry_size, + got, got_plt, got_irelative) + { } + + Output_data_plt_x86_64_standard(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative, + unsigned int plt_count) + : Output_data_plt_x86_64(layout, plt_entry_size, + got, got_plt, got_irelative, + plt_count) + { } + + protected: + virtual unsigned int + do_get_plt_entry_size() const + { return plt_entry_size; } + + virtual void + do_add_eh_frame(Layout* layout) + { + layout->add_eh_frame_for_plt(this, + this->plt_eh_frame_cie, + this->plt_eh_frame_cie_size, + plt_eh_frame_fde, + plt_eh_frame_fde_size); + } + + virtual void + do_fill_first_plt_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_addr, + typename elfcpp::Elf_types::Elf_Addr plt_addr); + + virtual unsigned int + do_fill_plt_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + unsigned int got_offset, + unsigned int plt_offset, + unsigned int plt_index); + + virtual void + do_fill_tlsdesc_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + typename elfcpp::Elf_types::Elf_Addr got_base, + unsigned int tlsdesc_got_offset, + unsigned int plt_offset); + + private: + // The size of an entry in the PLT. + static const int plt_entry_size = 16; + + // The first entry in the PLT. + // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same + // procedure linkage table for both programs and shared objects." + static const unsigned char first_plt_entry[plt_entry_size]; + + // Other entries in the PLT for an executable. + static const unsigned char plt_entry[plt_entry_size]; + + // The reserved TLSDESC entry in the PLT for an executable. + static const unsigned char tlsdesc_plt_entry[plt_entry_size]; + + // The .eh_frame unwind information for the PLT. + static const int plt_eh_frame_fde_size = 32; + static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size]; +}; // The x86_64 target class. // See the ABI at @@ -60,25 +410,46 @@ class Output_data_plt_x86_64; // http://people.redhat.com/drepper/tls.pdf // http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt -class Target_x86_64 : public Sized_target<64, false> +template +class Target_x86_64 : public Sized_target { public: // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures // uses only Elf64_Rela relocation entries with explicit addends." - typedef Output_data_reloc Reloc_section; - - Target_x86_64() - : Sized_target<64, false>(&x86_64_info), - got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL), - copy_relocs_(NULL), dynbss_(NULL) + typedef Output_data_reloc Reloc_section; + + Target_x86_64(const Target::Target_info* info = &x86_64_info) + : Sized_target(info), + got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL), + got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL), + rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY), + got_mod_index_offset_(-1U), tlsdesc_reloc_info_(), + tls_base_symbol_defined_(false) { } + // Hook for a new output section. + void + do_new_output_section(Output_section*) const; + // Scan the relocations to look for symbol adjustments. void - scan_relocs(const General_options& options, - Symbol_table* symtab, + gc_process_relocs(Symbol_table* symtab, + Layout* layout, + Sized_relobj_file* 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<64, false>* object, + Sized_relobj_file* object, unsigned int data_shndx, unsigned int sh_type, const unsigned char* prelocs, @@ -90,7 +461,7 @@ class Target_x86_64 : public Sized_target<64, false> // Finalize the sections. void - do_finalize_sections(Layout*); + do_finalize_sections(Layout*, const Input_objects*, Symbol_table*); // Return the value to use for a dynamic which requires special // treatment. @@ -99,61 +470,296 @@ class Target_x86_64 : public Sized_target<64, false> // Relocate a section. void - relocate_section(const Relocate_info<64, false>*, + relocate_section(const Relocate_info*, unsigned int sh_type, const unsigned char* prelocs, size_t reloc_count, Output_section* output_section, bool needs_special_offset_handling, unsigned char* view, - elfcpp::Elf_types<64>::Elf_Addr view_address, - off_t view_size); + typename elfcpp::Elf_types::Elf_Addr 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_file* 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*); + + // Emit relocations for a section. + void + relocate_relocs( + const Relocate_info*, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + typename elfcpp::Elf_types::Elf_Off offset_in_output_section, + const Relocatable_relocs*, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr view_address, + section_size_type view_size, + unsigned char* reloc_view, + section_size_type reloc_view_size); // Return a string used to fill a code section with nops. std::string - do_code_fill(off_t length); + do_code_fill(section_size_type length) const; // Return whether SYM is defined by the ABI. bool - do_is_defined_by_abi(Symbol* sym) const + do_is_defined_by_abi(const Symbol* sym) const { return strcmp(sym->name(), "__tls_get_addr") == 0; } + // Return the symbol index to use for a target specific relocation. + // The only target specific relocation is R_X86_64_TLSDESC for a + // local symbol, which is an absolute reloc. + unsigned int + do_reloc_symbol_index(void*, unsigned int r_type) const + { + gold_assert(r_type == elfcpp::R_X86_64_TLSDESC); + return 0; + } + + // Return the addend to use for a target specific relocation. + uint64_t + do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const; + + // Return the PLT section. + uint64_t + do_plt_address_for_global(const Symbol* gsym) const + { return this->plt_section()->address_for_global(gsym); } + + uint64_t + do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const + { return this->plt_section()->address_for_local(relobj, symndx); } + + // This function should be defined in targets that can use relocation + // types to determine (implemented in local_reloc_may_be_function_pointer + // and global_reloc_may_be_function_pointer) + // if a function's pointer is taken. ICF uses this in safe mode to only + // fold those functions whose pointer is defintely not taken. For x86_64 + // pie binaries, safe ICF cannot be done by looking at relocation types. + bool + do_can_check_for_function_pointers() const + { return !parameters->options().pie(); } + + // Return the base for a DW_EH_PE_datarel encoding. + uint64_t + do_ehframe_datarel_base() const; + + // Adjust -fsplit-stack code which calls non-split-stack code. + void + do_calls_non_split(Relobj* object, unsigned int shndx, + section_offset_type fnoffset, section_size_type fnsize, + unsigned char* view, section_size_type view_size, + std::string* from, std::string* to) const; + // Return the size of the GOT section. - off_t - got_size() + section_size_type + got_size() const { gold_assert(this->got_ != NULL); return this->got_->data_size(); } + // Return the number of entries in the GOT. + unsigned int + got_entry_count() const + { + if (this->got_ == NULL) + return 0; + return this->got_size() / 8; + } + + // Return the number of entries in the PLT. + unsigned int + plt_entry_count() const; + + // Return the offset of the first non-reserved PLT entry. + unsigned int + first_plt_entry_offset() const; + + // Return the size of each PLT entry. + unsigned int + plt_entry_size() const; + + // Return the size of each GOT entry. + unsigned int + got_entry_size() const + { return 8; }; + + // Create the GOT section for an incremental update. + Output_data_got_base* + init_got_plt_for_update(Symbol_table* symtab, + Layout* layout, + unsigned int got_count, + unsigned int plt_count); + + // Reserve a GOT entry for a local symbol, and regenerate any + // necessary dynamic relocations. + void + reserve_local_got_entry(unsigned int got_index, + Sized_relobj* obj, + unsigned int r_sym, + unsigned int got_type); + + // Reserve a GOT entry for a global symbol, and regenerate any + // necessary dynamic relocations. + void + reserve_global_got_entry(unsigned int got_index, Symbol* gsym, + unsigned int got_type); + + // Register an existing PLT entry for a global symbol. + void + register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index, + Symbol* gsym); + + // Force a COPY relocation for a given symbol. + void + emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t); + + // Apply an incremental relocation. + void + apply_relocation(const Relocate_info* relinfo, + typename elfcpp::Elf_types::Elf_Addr r_offset, + unsigned int r_type, + typename elfcpp::Elf_types::Elf_Swxword r_addend, + const Symbol* gsym, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size); + + // Add a new reloc argument, returning the index in the vector. + size_t + add_tlsdesc_info(Sized_relobj_file* object, unsigned int r_sym) + { + this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym)); + return this->tlsdesc_reloc_info_.size() - 1; + } + + Output_data_plt_x86_64* + make_data_plt(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative) + { + return this->do_make_data_plt(layout, got, got_plt, got_irelative); + } + + Output_data_plt_x86_64* + make_data_plt(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative, + unsigned int plt_count) + { + return this->do_make_data_plt(layout, got, got_plt, got_irelative, + plt_count); + } + + virtual Output_data_plt_x86_64* + do_make_data_plt(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative) + { + return new Output_data_plt_x86_64_standard(layout, got, got_plt, + got_irelative); + } + + virtual Output_data_plt_x86_64* + do_make_data_plt(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative, + unsigned int plt_count) + { + return new Output_data_plt_x86_64_standard(layout, got, got_plt, + got_irelative, + plt_count); + } + private: // The class which scans relocations. - struct Scan + class Scan { + public: + Scan() + : issued_non_pic_error_(false) + { } + + static inline int + get_reference_flags(unsigned int r_type); + inline void - local(const General_options& options, Symbol_table* symtab, - Layout* layout, Target_x86_64* target, - Sized_relobj<64, false>* object, + local(Symbol_table* symtab, Layout* layout, Target_x86_64* target, + Sized_relobj_file* object, unsigned int data_shndx, Output_section* output_section, - const elfcpp::Rela<64, false>& reloc, unsigned int r_type, - const elfcpp::Sym<64, false>& lsym); + const elfcpp::Rela& reloc, unsigned int r_type, + const elfcpp::Sym& lsym, + bool is_discarded); inline void - global(const General_options& options, Symbol_table* symtab, - Layout* layout, Target_x86_64* target, - Sized_relobj<64, false>* object, + global(Symbol_table* symtab, Layout* layout, Target_x86_64* target, + Sized_relobj_file* object, unsigned int data_shndx, Output_section* output_section, - const elfcpp::Rela<64, false>& reloc, unsigned int r_type, + const elfcpp::Rela& reloc, unsigned int r_type, Symbol* gsym); + inline bool + local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout, + Target_x86_64* target, + Sized_relobj_file* object, + unsigned int data_shndx, + Output_section* output_section, + const elfcpp::Rela& reloc, + unsigned int r_type, + const elfcpp::Sym& lsym); + + inline bool + global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout, + Target_x86_64* target, + Sized_relobj_file* object, + unsigned int data_shndx, + Output_section* output_section, + const elfcpp::Rela& reloc, + unsigned int r_type, + Symbol* gsym); + + private: static void - unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type); + unsupported_reloc_local(Sized_relobj_file*, + unsigned int r_type); static void - unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type, - Symbol*); + unsupported_reloc_global(Sized_relobj_file*, + unsigned int r_type, Symbol*); + + void + check_non_pic(Relobj*, unsigned int r_type, Symbol*); + + inline bool + possible_function_pointer_reloc(unsigned int r_type); + + bool + reloc_needs_plt_for_ifunc(Sized_relobj_file*, + unsigned int r_type); + + // Whether we have issued an error about a non-PIC compilation. + bool issued_non_pic_error_; }; // The class which implements relocation. @@ -176,63 +782,113 @@ class Target_x86_64 : public Sized_target<64, false> // Do a relocation. Return false if the caller should not issue // any warnings about this relocation. inline bool - relocate(const Relocate_info<64, false>*, Target_x86_64*, size_t relnum, - const elfcpp::Rela<64, false>&, - unsigned int r_type, const Sized_symbol<64>*, - const Symbol_value<64>*, - unsigned char*, elfcpp::Elf_types<64>::Elf_Addr, - off_t); + relocate(const Relocate_info*, Target_x86_64*, + Output_section*, + size_t relnum, const elfcpp::Rela&, + unsigned int r_type, const Sized_symbol*, + const Symbol_value*, + unsigned char*, typename elfcpp::Elf_types::Elf_Addr, + section_size_type); private: // Do a TLS relocation. inline void - relocate_tls(const Relocate_info<64, false>*, Target_x86_64*, - size_t relnum, const elfcpp::Rela<64, false>&, - unsigned int r_type, const Sized_symbol<64>*, - const Symbol_value<64>*, - unsigned char*, elfcpp::Elf_types<64>::Elf_Addr, off_t); - - // Do a TLS General-Dynamic to Local-Exec transition. + relocate_tls(const Relocate_info*, Target_x86_64*, + size_t relnum, const elfcpp::Rela&, + unsigned int r_type, const Sized_symbol*, + const Symbol_value*, + unsigned char*, typename elfcpp::Elf_types::Elf_Addr, + section_size_type); + + // Do a TLS General-Dynamic to Initial-Exec transition. inline void - tls_gd_to_ie(const Relocate_info<64, false>*, size_t relnum, + tls_gd_to_ie(const Relocate_info*, size_t relnum, Output_segment* tls_segment, - const elfcpp::Rela<64, false>&, unsigned int r_type, - elfcpp::Elf_types<64>::Elf_Addr value, + const elfcpp::Rela&, unsigned int r_type, + typename elfcpp::Elf_types::Elf_Addr value, unsigned char* view, - off_t view_size); + typename elfcpp::Elf_types::Elf_Addr, + section_size_type view_size); // Do a TLS General-Dynamic to Local-Exec transition. inline void - tls_gd_to_le(const Relocate_info<64, false>*, size_t relnum, + tls_gd_to_le(const Relocate_info*, size_t relnum, Output_segment* tls_segment, - const elfcpp::Rela<64, false>&, unsigned int r_type, - elfcpp::Elf_types<64>::Elf_Addr value, + const elfcpp::Rela&, unsigned int r_type, + typename elfcpp::Elf_types::Elf_Addr value, unsigned char* view, - off_t view_size); + section_size_type view_size); + + // Do a TLSDESC-style General-Dynamic to Initial-Exec transition. + inline void + tls_desc_gd_to_ie(const Relocate_info*, size_t relnum, + Output_segment* tls_segment, + const elfcpp::Rela&, unsigned int r_type, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr, + section_size_type view_size); + + // Do a TLSDESC-style General-Dynamic to Local-Exec transition. + inline void + tls_desc_gd_to_le(const Relocate_info*, size_t relnum, + Output_segment* tls_segment, + const elfcpp::Rela&, unsigned int r_type, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned char* view, + section_size_type view_size); // Do a TLS Local-Dynamic to Local-Exec transition. inline void - tls_ld_to_le(const Relocate_info<64, false>*, size_t relnum, + tls_ld_to_le(const Relocate_info*, size_t relnum, Output_segment* tls_segment, - const elfcpp::Rela<64, false>&, unsigned int r_type, - elfcpp::Elf_types<64>::Elf_Addr value, + const elfcpp::Rela&, unsigned int r_type, + typename elfcpp::Elf_types::Elf_Addr value, unsigned char* view, - off_t view_size); + section_size_type view_size); // Do a TLS Initial-Exec to Local-Exec transition. static inline void - tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum, + tls_ie_to_le(const Relocate_info*, size_t relnum, Output_segment* tls_segment, - const elfcpp::Rela<64, false>&, unsigned int r_type, - elfcpp::Elf_types<64>::Elf_Addr value, + const elfcpp::Rela&, unsigned int r_type, + typename elfcpp::Elf_types::Elf_Addr value, unsigned char* view, - off_t view_size); + section_size_type view_size); // 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_; }; + // 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*); + }; + + // Check if relocation against this symbol is a candidate for + // conversion from + // mov foo@GOTPCREL(%rip), %reg + // to lea foo(%rip), %reg. + static bool + can_convert_mov_to_lea(const Symbol* gsym) + { + gold_assert(gsym != NULL); + return (gsym->type() != elfcpp::STT_GNU_IFUNC + && !gsym->is_undefined () + && !gsym->is_from_dynobj() + && !gsym->is_preemptible() + && (!parameters->options().shared() + || (gsym->visibility() != elfcpp::STV_DEFAULT + && gsym->visibility() != elfcpp::STV_PROTECTED) + || parameters->options().Bsymbolic()) + && strcmp(gsym->name(), "_DYNAMIC") != 0); + } + // Adjust TLS relocation type based on the options and whether this // is a local symbol. static tls::Tls_optimization @@ -243,19 +899,50 @@ class Target_x86_64 : public Sized_target<64, false> got_section(Symbol_table*, Layout*); // Get the GOT PLT section. - Output_data_space* + Output_data_got_plt_x86_64* got_plt_section() const { gold_assert(this->got_plt_ != NULL); return this->got_plt_; } + // Get the GOT section for TLSDESC entries. + Output_data_got<64, false>* + got_tlsdesc_section() const + { + gold_assert(this->got_tlsdesc_ != NULL); + return this->got_tlsdesc_; + } + + // Create the PLT section. + void + make_plt_section(Symbol_table* symtab, Layout* layout); + // Create a PLT entry for a global symbol. void make_plt_entry(Symbol_table*, Layout*, Symbol*); + // Create a PLT entry for a local STT_GNU_IFUNC symbol. + void + make_local_ifunc_plt_entry(Symbol_table*, Layout*, + Sized_relobj_file* relobj, + unsigned int local_sym_index); + + // Define the _TLS_MODULE_BASE_ symbol in the TLS segment. + void + define_tls_base_symbol(Symbol_table*, Layout*); + + // Create the reserved PLT and GOT entries for the TLS descriptor resolver. + void + reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout); + + // Create a GOT entry for the TLS module index. + unsigned int + got_mod_index_entry(Symbol_table* symtab, Layout* layout, + Sized_relobj_file* object); + // Get the PLT section. - Output_data_plt_x86_64* + Output_data_plt_x86_64* plt_section() const { gold_assert(this->plt_ != NULL); @@ -266,42 +953,88 @@ class Target_x86_64 : public Sized_target<64, false> Reloc_section* rela_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 (!parameters->output_is_shared() - && gsym->is_from_dynobj() - && gsym->type() != elfcpp::STT_FUNC); - } + // Get the section to use for TLSDESC relocations. + Reloc_section* + rela_tlsdesc_section(Layout*) const; + + // Get the section to use for IRELATIVE relocations. + Reloc_section* + rela_irelative_section(Layout*); - // Copy a relocation against a global symbol. + // Add a potential copy relocation. void - copy_reloc(const General_options*, Symbol_table*, Layout*, - Sized_relobj<64, false>*, unsigned int, - Output_section*, Symbol*, const elfcpp::Rela<64, false>&); + copy_reloc(Symbol_table* symtab, Layout* layout, + Sized_relobj_file* object, + unsigned int shndx, Output_section* output_section, + Symbol* sym, const elfcpp::Rela& reloc) + { + this->copy_relocs_.copy_reloc(symtab, layout, + symtab->get_sized_symbol(sym), + object, shndx, output_section, + reloc, this->rela_dyn_section(layout)); + } // Information about this specific target which we pass to the // general Target structure. static const Target::Target_info x86_64_info; + // The types of GOT entries needed for this platform. + // These values are exposed to the ABI in an incremental link. + // Do not renumber existing values without changing the version + // number of the .gnu_incremental_inputs section. + enum Got_type + { + GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol + GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset + GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair + GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair + }; + + // This type is used as the argument to the target specific + // relocation routines. The only target specific reloc is + // R_X86_64_TLSDESC against a local symbol. + struct Tlsdesc_info + { + Tlsdesc_info(Sized_relobj_file* a_object, unsigned int a_r_sym) + : object(a_object), r_sym(a_r_sym) + { } + + // The object in which the local symbol is defined. + Sized_relobj_file* object; + // The local symbol index in the object. + unsigned int r_sym; + }; + // The GOT section. Output_data_got<64, false>* got_; // The PLT section. - Output_data_plt_x86_64* plt_; + Output_data_plt_x86_64* plt_; // The GOT PLT section. - Output_data_space* got_plt_; + Output_data_got_plt_x86_64* got_plt_; + // The GOT section for IRELATIVE relocations. + Output_data_space* got_irelative_; + // The GOT section for TLSDESC relocations. + Output_data_got<64, false>* got_tlsdesc_; + // The _GLOBAL_OFFSET_TABLE_ symbol. + Symbol* global_offset_table_; // The dynamic reloc section. Reloc_section* rela_dyn_; + // The section to use for IRELATIVE relocs. + Reloc_section* rela_irelative_; // Relocs saved to avoid a COPY reloc. - Copy_relocs<64, false>* copy_relocs_; - // Space for variables copied with a COPY reloc. - Output_data_space* dynbss_; + Copy_relocs copy_relocs_; + // Offset of the GOT entry for the TLS module index. + unsigned int got_mod_index_offset_; + // We handle R_X86_64_TLSDESC against a local symbol as a target + // specific relocation. Here we store the object and local symbol + // index for the relocation. + std::vector tlsdesc_reloc_info_; + // True if the _TLS_MODULE_BASE_ symbol has been defined. + bool tls_base_symbol_defined_; }; -const Target::Target_info Target_x86_64::x86_64_info = +template<> +const Target::Target_info Target_x86_64<64>::x86_64_info = { 64, // size false, // is_big_endian @@ -310,46 +1043,134 @@ const Target::Target_info Target_x86_64::x86_64_info = false, // has_resolve true, // has_code_fill true, // is_default_stack_executable + true, // can_icf_inline_merge_sections + '\0', // wrap_char "/lib/ld64.so.1", // program interpreter 0x400000, // default_text_segment_address - 0x1000, // abi_pagesize - 0x1000 // common_pagesize + 0x1000, // abi_pagesize (overridable by -z max-page-size) + 0x1000, // common_pagesize (overridable by -z common-page-size) + false, // isolate_execinstr + 0, // rosegment_gap + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx + 0, // small_common_section_flags + elfcpp::SHF_X86_64_LARGE, // large_common_section_flags + NULL, // attributes_section + NULL, // attributes_vendor + "_start", // entry_symbol_name + 32, // hash_entry_size +}; + +template<> +const Target::Target_info Target_x86_64<32>::x86_64_info = +{ + 32, // size + false, // is_big_endian + elfcpp::EM_X86_64, // machine_code + false, // has_make_symbol + false, // has_resolve + true, // has_code_fill + true, // is_default_stack_executable + true, // can_icf_inline_merge_sections + '\0', // wrap_char + "/libx32/ldx32.so.1", // program interpreter + 0x400000, // default_text_segment_address + 0x1000, // abi_pagesize (overridable by -z max-page-size) + 0x1000, // common_pagesize (overridable by -z common-page-size) + false, // isolate_execinstr + 0, // rosegment_gap + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx + 0, // small_common_section_flags + elfcpp::SHF_X86_64_LARGE, // large_common_section_flags + NULL, // attributes_section + NULL, // attributes_vendor + "_start", // entry_symbol_name + 32, // hash_entry_size }; +// This is called when a new output section is created. This is where +// we handle the SHF_X86_64_LARGE. + +template +void +Target_x86_64::do_new_output_section(Output_section* os) const +{ + if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0) + os->set_is_large_section(); +} + // Get the GOT section, creating it if necessary. +template Output_data_got<64, false>* -Target_x86_64::got_section(Symbol_table* symtab, Layout* layout) +Target_x86_64::got_section(Symbol_table* symtab, Layout* layout) { if (this->got_ == NULL) { gold_assert(symtab != NULL && layout != NULL); + // When using -z now, we can treat .got.plt as a relro section. + // Without -z now, it is modified after program startup by lazy + // PLT relocations. + bool is_got_plt_relro = parameters->options().now(); + Output_section_order got_order = (is_got_plt_relro + ? ORDER_RELRO + : ORDER_RELRO_LAST); + Output_section_order got_plt_order = (is_got_plt_relro + ? ORDER_RELRO + : ORDER_NON_RELRO_FIRST); + this->got_ = new Output_data_got<64, false>(); 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(8); - layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, - elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, - this->got_plt_); + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_, got_order, true); + + this->got_plt_ = new Output_data_got_plt_x86_64(layout); + layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_plt_, got_plt_order, + is_got_plt_relro); // The first three entries are reserved. this->got_plt_->set_current_data_size(3 * 8); + if (!is_got_plt_relro) + { + // Those bytes can go into the relro segment. + layout->increase_relro(3 * 8); + } + // 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); + this->global_offset_table_ = + symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, + Symbol_table::PREDEFINED, + this->got_plt_, + 0, 0, elfcpp::STT_OBJECT, + elfcpp::STB_LOCAL, + elfcpp::STV_HIDDEN, 0, + false, false); + + // If there are any IRELATIVE relocations, they get GOT entries + // in .got.plt after the jump slot entries. + this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT"); + layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_irelative_, + got_plt_order, is_got_plt_relro); + + // If there are any TLSDESC relocations, they get GOT entries in + // .got.plt after the jump slot and IRELATIVE entries. + this->got_tlsdesc_ = new Output_data_got<64, false>(); + layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_tlsdesc_, + got_plt_order, is_got_plt_relro); } return this->got_; @@ -357,124 +1178,319 @@ Target_x86_64::got_section(Symbol_table* symtab, Layout* layout) // Get the dynamic reloc section, creating it if necessary. -Target_x86_64::Reloc_section* -Target_x86_64::rela_dyn_section(Layout* layout) +template +typename Target_x86_64::Reloc_section* +Target_x86_64::rela_dyn_section(Layout* layout) { if (this->rela_dyn_ == NULL) { gold_assert(layout != NULL); - this->rela_dyn_ = new Reloc_section(); + this->rela_dyn_ = new Reloc_section(parameters->options().combreloc()); layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA, - elfcpp::SHF_ALLOC, this->rela_dyn_); + elfcpp::SHF_ALLOC, this->rela_dyn_, + ORDER_DYNAMIC_RELOCS, false); } return this->rela_dyn_; } -// A class to handle the PLT data. +// Get the section to use for IRELATIVE relocs, creating it if +// necessary. These go in .rela.dyn, but only after all other dynamic +// relocations. They need to follow the other dynamic relocations so +// that they can refer to global variables initialized by those +// relocs. -class Output_data_plt_x86_64 : public Output_section_data +template +typename Target_x86_64::Reloc_section* +Target_x86_64::rela_irelative_section(Layout* layout) { - public: - typedef Output_data_reloc Reloc_section; - - Output_data_plt_x86_64(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); - - private: - // The size of an entry in the PLT. - static const int plt_entry_size = 16; - - // The first entry in the PLT. - // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same - // procedure linkage table for both programs and shared objects." - static unsigned char first_plt_entry[plt_entry_size]; - - // Other entries in the PLT for an executable. - static unsigned char plt_entry[plt_entry_size]; - - // Set the final size. - void - set_final_data_size() - { this->set_data_size((this->count_ + 1) * plt_entry_size); } + if (this->rela_irelative_ == NULL) + { + // Make sure we have already created the dynamic reloc section. + this->rela_dyn_section(layout); + this->rela_irelative_ = new Reloc_section(false); + layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA, + elfcpp::SHF_ALLOC, this->rela_irelative_, + ORDER_DYNAMIC_RELOCS, false); + gold_assert(this->rela_dyn_->output_section() + == this->rela_irelative_->output_section()); + } + return this->rela_irelative_; +} - // Write out the PLT data. - void - do_write(Output_file*); +// Write the first three reserved words of the .got.plt section. +// The remainder of the section is written while writing the PLT +// in Output_data_plt_i386::do_write. - // The reloc section. - Reloc_section* rel_; - // The .got.plt section. - Output_data_space* got_plt_; - // The number of PLT entries. - unsigned int count_; -}; +void +Output_data_got_plt_x86_64::do_write(Output_file* of) +{ + // The first entry in the GOT is the address of the .dynamic section + // aka the PT_DYNAMIC segment. The next two entries are reserved. + // We saved space for them when we created the section in + // Target_x86_64::got_section. + const off_t got_file_offset = this->offset(); + gold_assert(this->data_size() >= 24); + unsigned char* const got_view = of->get_output_view(got_file_offset, 24); + Output_section* dynamic = this->layout_->dynamic_section(); + uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address(); + elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr); + memset(got_view + 8, 0, 16); + of->write_output_view(got_file_offset, 24, got_view); +} -// 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. +// Initialize the PLT section. -Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout, - Output_data_space* got_plt) - : Output_section_data(8), got_plt_(got_plt), count_(0) +template +void +Output_data_plt_x86_64::init(Layout* layout) { - this->rel_ = new Reloc_section(); + this->rel_ = new Reloc_section(false); layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA, - elfcpp::SHF_ALLOC, this->rel_); + elfcpp::SHF_ALLOC, this->rel_, + ORDER_DYNAMIC_PLT_RELOCS, false); } +template void -Output_data_plt_x86_64::do_adjust_output_section(Output_section* os) +Output_data_plt_x86_64::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); + os->set_entsize(this->get_plt_entry_size()); } // Add an entry to the PLT. +template void -Output_data_plt_x86_64::add_entry(Symbol* gsym) +Output_data_plt_x86_64::add_entry(Symbol_table* symtab, Layout* layout, + 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); + unsigned int plt_index; + off_t plt_offset; + section_offset_type got_offset; + + unsigned int* pcount; + unsigned int offset; + unsigned int reserved; + Output_section_data_build* got; + if (gsym->type() == elfcpp::STT_GNU_IFUNC + && gsym->can_use_relative_reloc(false)) + { + pcount = &this->irelative_count_; + offset = 0; + reserved = 0; + got = this->got_irelative_; + } + else + { + pcount = &this->count_; + offset = 1; + reserved = 3; + got = this->got_plt_; + } + + if (!this->is_data_size_valid()) + { + // Note that when setting the PLT offset for a non-IRELATIVE + // entry we skip the initial reserved PLT entry. + plt_index = *pcount + offset; + plt_offset = plt_index * this->get_plt_entry_size(); - ++this->count_; + ++*pcount; - off_t got_offset = this->got_plt_->current_data_size(); + got_offset = (plt_index - offset + reserved) * 8; + gold_assert(got_offset == got->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 + 8); + // 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). + got->set_current_data_size(got_offset + 8); + } + else + { + // FIXME: This is probably not correct for IRELATIVE relocs. + + // For incremental updates, find an available slot. + plt_offset = this->free_list_.allocate(this->get_plt_entry_size(), + this->get_plt_entry_size(), 0); + if (plt_offset == -1) + gold_fallback(_("out of patch space (PLT);" + " relink with --incremental-full")); + + // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset + // can be calculated from the PLT index, adjusting for the three + // reserved entries at the beginning of the GOT. + plt_index = plt_offset / this->get_plt_entry_size() - 1; + got_offset = (plt_index - offset + reserved) * 8; + } + + gsym->set_plt_offset(plt_offset); // Every PLT entry needs a reloc. - gsym->set_needs_dynsym_entry(); - this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_, - got_offset, 0); + this->add_relocation(symtab, layout, gsym, 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. } +// Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return +// the PLT offset. + +template +unsigned int +Output_data_plt_x86_64::add_local_ifunc_entry( + Symbol_table* symtab, + Layout* layout, + Sized_relobj_file* relobj, + unsigned int local_sym_index) +{ + unsigned int plt_offset = this->irelative_count_ * this->get_plt_entry_size(); + ++this->irelative_count_; + + section_offset_type got_offset = this->got_irelative_->current_data_size(); + + // Every PLT entry needs a GOT entry which points back to the PLT + // entry. + this->got_irelative_->set_current_data_size(got_offset + 8); + + // Every PLT entry needs a reloc. + Reloc_section* rela = this->rela_irelative(symtab, layout); + rela->add_symbolless_local_addend(relobj, local_sym_index, + elfcpp::R_X86_64_IRELATIVE, + this->got_irelative_, got_offset, 0); + + return plt_offset; +} + +// Add the relocation for a PLT entry. + +template +void +Output_data_plt_x86_64::add_relocation(Symbol_table* symtab, + Layout* layout, + Symbol* gsym, + unsigned int got_offset) +{ + if (gsym->type() == elfcpp::STT_GNU_IFUNC + && gsym->can_use_relative_reloc(false)) + { + Reloc_section* rela = this->rela_irelative(symtab, layout); + rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE, + this->got_irelative_, got_offset, 0); + } + else + { + gsym->set_needs_dynsym_entry(); + this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_, + got_offset, 0); + } +} + +// Return where the TLSDESC relocations should go, creating it if +// necessary. These follow the JUMP_SLOT relocations. + +template +typename Output_data_plt_x86_64::Reloc_section* +Output_data_plt_x86_64::rela_tlsdesc(Layout* layout) +{ + if (this->tlsdesc_rel_ == NULL) + { + this->tlsdesc_rel_ = new Reloc_section(false); + layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA, + elfcpp::SHF_ALLOC, this->tlsdesc_rel_, + ORDER_DYNAMIC_PLT_RELOCS, false); + gold_assert(this->tlsdesc_rel_->output_section() + == this->rel_->output_section()); + } + return this->tlsdesc_rel_; +} + +// Return where the IRELATIVE relocations should go in the PLT. These +// follow the JUMP_SLOT and the TLSDESC relocations. + +template +typename Output_data_plt_x86_64::Reloc_section* +Output_data_plt_x86_64::rela_irelative(Symbol_table* symtab, + Layout* layout) +{ + if (this->irelative_rel_ == NULL) + { + // Make sure we have a place for the TLSDESC relocations, in + // case we see any later on. + this->rela_tlsdesc(layout); + this->irelative_rel_ = new Reloc_section(false); + layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA, + elfcpp::SHF_ALLOC, this->irelative_rel_, + ORDER_DYNAMIC_PLT_RELOCS, false); + gold_assert(this->irelative_rel_->output_section() + == this->rel_->output_section()); + + if (parameters->doing_static_link()) + { + // A statically linked executable will only have a .rela.plt + // section to hold R_X86_64_IRELATIVE relocs for + // STT_GNU_IFUNC symbols. The library will use these + // symbols to locate the IRELATIVE relocs at program startup + // time. + symtab->define_in_output_data("__rela_iplt_start", NULL, + Symbol_table::PREDEFINED, + this->irelative_rel_, 0, 0, + elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, + elfcpp::STV_HIDDEN, 0, false, true); + symtab->define_in_output_data("__rela_iplt_end", NULL, + Symbol_table::PREDEFINED, + this->irelative_rel_, 0, 0, + elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, + elfcpp::STV_HIDDEN, 0, true, true); + } + } + return this->irelative_rel_; +} + +// Return the PLT address to use for a global symbol. + +template +uint64_t +Output_data_plt_x86_64::address_for_global(const Symbol* gsym) +{ + uint64_t offset = 0; + if (gsym->type() == elfcpp::STT_GNU_IFUNC + && gsym->can_use_relative_reloc(false)) + offset = (this->count_ + 1) * this->get_plt_entry_size(); + return this->address() + offset + gsym->plt_offset(); +} + +// Return the PLT address to use for a local symbol. These are always +// IRELATIVE relocs. + +template +uint64_t +Output_data_plt_x86_64::address_for_local(const Relobj* object, + unsigned int r_sym) +{ + return (this->address() + + (this->count_ + 1) * this->get_plt_entry_size() + + object->local_plt_offset(r_sym)); +} + +// Set the final size. +template +void +Output_data_plt_x86_64::set_final_data_size() +{ + unsigned int count = this->count_ + this->irelative_count_; + if (this->has_tlsdesc_entry()) + ++count; + this->set_data_size((count + 1) * this->get_plt_entry_size()); +} + // The first entry in the PLT for an executable. -unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] = +template +const unsigned char +Output_data_plt_x86_64_standard::first_plt_entry[plt_entry_size] = { // From AMD64 ABI Draft 0.98, page 76 0xff, 0x35, // pushq contents of memory address @@ -484,9 +1500,28 @@ unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] = 0x90, 0x90, 0x90, 0x90 // noop (x4) }; +template +void +Output_data_plt_x86_64_standard::do_fill_first_plt_entry( + unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address) +{ + memcpy(pov, first_plt_entry, plt_entry_size); + // We do a jmp relative to the PC at the end of this instruction. + elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, + (got_address + 8 + - (plt_address + 6))); + elfcpp::Swap<32, false>::writeval(pov + 8, + (got_address + 16 + - (plt_address + 12))); +} + // Subsequent entries in the PLT for an executable. -unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] = +template +const unsigned char +Output_data_plt_x86_64_standard::plt_entry[plt_entry_size] = { // From AMD64 ABI Draft 0.98, page 76 0xff, 0x25, // jmpq indirect @@ -497,189 +1532,587 @@ unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] = 0, 0, 0, 0 // replaced with offset to start of .plt }; +template +unsigned int +Output_data_plt_x86_64_standard::do_fill_plt_entry( + unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + unsigned int got_offset, + unsigned int plt_offset, + unsigned int plt_index) +{ + // Check PC-relative offset overflow in PLT entry. + uint64_t plt_got_pcrel_offset = (got_address + got_offset + - (plt_address + plt_offset + 6)); + if (Bits<32>::has_overflow(plt_got_pcrel_offset)) + gold_error(_("PC-relative offset overflow in PLT entry %d"), + plt_index + 1); + + memcpy(pov, plt_entry, plt_entry_size); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, + plt_got_pcrel_offset); + + elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index); + elfcpp::Swap<32, false>::writeval(pov + 12, + - (plt_offset + plt_entry_size)); + + return 6; +} + +// The reserved TLSDESC entry in the PLT for an executable. + +template +const unsigned char +Output_data_plt_x86_64_standard::tlsdesc_plt_entry[plt_entry_size] = +{ + // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32 + // and AMD64/EM64T", Version 0.9.4 (2005-10-10). + 0xff, 0x35, // pushq x(%rip) + 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8) + 0xff, 0x25, // jmpq *y(%rip) + 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry + 0x0f, 0x1f, // nop + 0x40, 0 +}; + +template +void +Output_data_plt_x86_64_standard::do_fill_tlsdesc_entry( + unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + typename elfcpp::Elf_types::Elf_Addr got_base, + unsigned int tlsdesc_got_offset, + unsigned int plt_offset) +{ + memcpy(pov, tlsdesc_plt_entry, plt_entry_size); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, + (got_address + 8 + - (plt_address + plt_offset + + 6))); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 8, + (got_base + + tlsdesc_got_offset + - (plt_address + plt_offset + + 12))); +} + +// The .eh_frame unwind information for the PLT. + +template +const unsigned char +Output_data_plt_x86_64::plt_eh_frame_cie[plt_eh_frame_cie_size] = +{ + 1, // CIE version. + 'z', // Augmentation: augmentation size included. + 'R', // Augmentation: FDE encoding included. + '\0', // End of augmentation string. + 1, // Code alignment factor. + 0x78, // Data alignment factor. + 16, // Return address column. + 1, // Augmentation size. + (elfcpp::DW_EH_PE_pcrel // FDE encoding. + | elfcpp::DW_EH_PE_sdata4), + elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8. + elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8. + elfcpp::DW_CFA_nop, // Align to 16 bytes. + elfcpp::DW_CFA_nop +}; + +template +const unsigned char +Output_data_plt_x86_64_standard::plt_eh_frame_fde[plt_eh_frame_fde_size] = +{ + 0, 0, 0, 0, // Replaced with offset to .plt. + 0, 0, 0, 0, // Replaced with size of .plt. + 0, // Augmentation size. + elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16. + elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6. + elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24. + elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16. + elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression. + 11, // Block length. + elfcpp::DW_OP_breg7, 8, // Push %rsp + 8. + elfcpp::DW_OP_breg16, 0, // Push %rip. + elfcpp::DW_OP_lit15, // Push 0xf. + elfcpp::DW_OP_and, // & (%rip & 0xf). + elfcpp::DW_OP_lit11, // Push 0xb. + elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 0xb) + elfcpp::DW_OP_lit3, // Push 3. + elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 0xb) << 3) + elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8 + elfcpp::DW_CFA_nop, // Align to 32 bytes. + elfcpp::DW_CFA_nop, + elfcpp::DW_CFA_nop, + elfcpp::DW_CFA_nop +}; + // Write out the PLT. This uses the hand-coded instructions above, // and adjusts them as needed. This is specified by the AMD64 ABI. +template void -Output_data_plt_x86_64::do_write(Output_file* of) +Output_data_plt_x86_64::do_write(Output_file* of) { const off_t offset = this->offset(); - const off_t oview_size = this->data_size(); + 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 off_t got_size = this->got_plt_->data_size(); + gold_assert(parameters->incremental_update() + || (got_file_offset + this->got_plt_->data_size() + == this->got_irelative_->offset())); + const section_size_type got_size = + convert_to_section_size_type(this->got_plt_->data_size() + + this->got_irelative_->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(); + // The base address of the .plt section. + typename elfcpp::Elf_types::Elf_Addr plt_address = this->address(); + // The base address of the .got section. + typename elfcpp::Elf_types::Elf_Addr got_base = this->got_->address(); + // The base address of the PLT portion of the .got section, + // which is where the GOT pointer will point, and where the + // three reserved GOT entries are located. + typename elfcpp::Elf_types::Elf_Addr got_address + = this->got_plt_->address(); - memcpy(pov, first_plt_entry, plt_entry_size); - // We do a jmp relative to the PC at the end of this instruction. - elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 8 - - (plt_address + 6)); - elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 16 - - (plt_address + 12)); - pov += plt_entry_size; + this->fill_first_plt_entry(pov, got_address, plt_address); + pov += this->get_plt_entry_size(); - unsigned char* got_pov = got_view; + // The first three entries in the GOT are reserved, and are written + // by Output_data_got_plt_x86_64::do_write. + unsigned char* got_pov = got_view + 24; - memset(got_pov, 0, 24); - got_pov += 24; - - unsigned int plt_offset = plt_entry_size; + unsigned int plt_offset = this->get_plt_entry_size(); unsigned int got_offset = 24; - const unsigned int count = this->count_; + const unsigned int count = this->count_ + this->irelative_count_; for (unsigned int plt_index = 0; plt_index < count; ++plt_index, - pov += plt_entry_size, + pov += this->get_plt_entry_size(), got_pov += 8, - plt_offset += plt_entry_size, + plt_offset += this->get_plt_entry_size(), got_offset += 8) { // Set and adjust the PLT entry itself. - memcpy(pov, plt_entry, plt_entry_size); - elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, - (got_address + got_offset - - (plt_address + plt_offset - + 6))); - - elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index); - elfcpp::Swap<32, false>::writeval(pov + 12, - - (plt_offset + plt_entry_size)); + unsigned int lazy_offset = this->fill_plt_entry(pov, + got_address, plt_address, + got_offset, plt_offset, + plt_index); // Set the entry in the GOT. - elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6); + elfcpp::Swap<64, false>::writeval(got_pov, + plt_address + plt_offset + lazy_offset); } - gold_assert(pov - oview == oview_size); - gold_assert(got_pov - got_view == got_size); + if (this->has_tlsdesc_entry()) + { + // Set and adjust the reserved TLSDESC PLT entry. + unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset(); + this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base, + tlsdesc_got_offset, plt_offset); + pov += this->get_plt_entry_size(); + } + + gold_assert(static_cast(pov - oview) == oview_size); + gold_assert(static_cast(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. +// Create the PLT section. +template void -Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout, - Symbol* gsym) +Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout) { - 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_x86_64(layout, this->got_plt_); + this->plt_ = this->make_data_plt(layout, this->got_, this->got_plt_, + this->got_irelative_); + + // Add unwind information if requested. + if (parameters->options().ld_generated_unwind_info()) + this->plt_->add_eh_frame(layout); + layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR), - this->plt_); + this->plt_, ORDER_PLT, false); + + // Make the sh_info field of .rela.plt point to .plt. + Output_section* rela_plt_os = this->plt_->rela_plt()->output_section(); + rela_plt_os->set_info_section(this->plt_->output_section()); } +} + +// Return the section for TLSDESC relocations. + +template +typename Target_x86_64::Reloc_section* +Target_x86_64::rela_tlsdesc_section(Layout* layout) const +{ + return this->plt_section()->rela_tlsdesc(layout); +} + +// Create a PLT entry for a global symbol. + +template +void +Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout, + Symbol* gsym) +{ + if (gsym->has_plt_offset()) + return; + + if (this->plt_ == NULL) + this->make_plt_section(symtab, layout); + + this->plt_->add_entry(symtab, layout, gsym); +} + +// Make a PLT entry for a local STT_GNU_IFUNC symbol. + +template +void +Target_x86_64::make_local_ifunc_plt_entry( + Symbol_table* symtab, Layout* layout, + Sized_relobj_file* relobj, + unsigned int local_sym_index) +{ + if (relobj->local_has_plt_offset(local_sym_index)) + return; + if (this->plt_ == NULL) + this->make_plt_section(symtab, layout); + unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout, + relobj, + local_sym_index); + relobj->set_local_plt_offset(local_sym_index, plt_offset); +} + +// Return the number of entries in the PLT. + +template +unsigned int +Target_x86_64::plt_entry_count() const +{ + if (this->plt_ == NULL) + return 0; + return this->plt_->entry_count(); +} + +// Return the offset of the first non-reserved PLT entry. + +template +unsigned int +Target_x86_64::first_plt_entry_offset() const +{ + return this->plt_->first_plt_entry_offset(); +} + +// Return the size of each PLT entry. + +template +unsigned int +Target_x86_64::plt_entry_size() const +{ + return this->plt_->get_plt_entry_size(); +} + +// Create the GOT and PLT sections for an incremental update. + +template +Output_data_got_base* +Target_x86_64::init_got_plt_for_update(Symbol_table* symtab, + Layout* layout, + unsigned int got_count, + unsigned int plt_count) +{ + gold_assert(this->got_ == NULL); + + this->got_ = new Output_data_got<64, false>(got_count * 8); + layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_, ORDER_RELRO_LAST, + true); + + // Add the three reserved entries. + this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8); + layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_plt_, ORDER_NON_RELRO_FIRST, + false); + + // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. + this->global_offset_table_ = + symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, + Symbol_table::PREDEFINED, + this->got_plt_, + 0, 0, elfcpp::STT_OBJECT, + elfcpp::STB_LOCAL, + elfcpp::STV_HIDDEN, 0, + false, false); + + // If there are any TLSDESC relocations, they get GOT entries in + // .got.plt after the jump slot entries. + // FIXME: Get the count for TLSDESC entries. + this->got_tlsdesc_ = new Output_data_got<64, false>(0); + layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, + elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, + this->got_tlsdesc_, + ORDER_NON_RELRO_FIRST, false); + + // If there are any IRELATIVE relocations, they get GOT entries in + // .got.plt after the jump slot and TLSDESC entries. + this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT"); + layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS, + elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE, + this->got_irelative_, + ORDER_NON_RELRO_FIRST, false); + + // Create the PLT section. + this->plt_ = this->make_data_plt(layout, this->got_, + this->got_plt_, + this->got_irelative_, + plt_count); + + // Add unwind information if requested. + if (parameters->options().ld_generated_unwind_info()) + this->plt_->add_eh_frame(layout); + + layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, + elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR, + this->plt_, ORDER_PLT, false); + + // Make the sh_info field of .rela.plt point to .plt. + Output_section* rela_plt_os = this->plt_->rela_plt()->output_section(); + rela_plt_os->set_info_section(this->plt_->output_section()); + + // Create the rela_dyn section. + this->rela_dyn_section(layout); + + return this->got_; +} - 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. +// Reserve a GOT entry for a local symbol, and regenerate any +// necessary dynamic relocations. +template void -Target_x86_64::copy_reloc(const General_options* options, - Symbol_table* symtab, - Layout* layout, - Sized_relobj<64, false>* object, - unsigned int data_shndx, - Output_section* output_section, - Symbol* gsym, - const elfcpp::Rela<64, false>& rela) -{ - Sized_symbol<64>* ssym; - ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(64) (gsym - SELECT_SIZE(64)); - - if (!Copy_relocs<64, false>::need_copy_reloc(options, object, - data_shndx, ssym)) +Target_x86_64::reserve_local_got_entry( + unsigned int got_index, + Sized_relobj* obj, + unsigned int r_sym, + unsigned int got_type) +{ + unsigned int got_offset = got_index * 8; + Reloc_section* rela_dyn = this->rela_dyn_section(NULL); + + this->got_->reserve_local(got_index, obj, r_sym, got_type); + switch (got_type) { - // 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<64, false>(); - this->copy_relocs_->save(ssym, object, data_shndx, output_section, rela); + case GOT_TYPE_STANDARD: + if (parameters->options().output_is_position_independent()) + rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE, + this->got_, got_offset, 0, false); + break; + case GOT_TYPE_TLS_OFFSET: + rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64, + this->got_, got_offset, 0); + break; + case GOT_TYPE_TLS_PAIR: + this->got_->reserve_slot(got_index + 1); + rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64, + this->got_, got_offset, 0); + break; + case GOT_TYPE_TLS_DESC: + gold_fatal(_("TLS_DESC not yet supported for incremental linking")); + // this->got_->reserve_slot(got_index + 1); + // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg, + // this->got_, got_offset, 0); + break; + default: + gold_unreachable(); } - else - { - // Allocate space for this symbol in the .bss section. +} - elfcpp::Elf_types<64>::Elf_WXword symsize = ssym->symsize(); +// Reserve a GOT entry for a global symbol, and regenerate any +// necessary dynamic relocations. - // 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; +template +void +Target_x86_64::reserve_global_got_entry(unsigned int got_index, + Symbol* gsym, + unsigned int got_type) +{ + unsigned int got_offset = got_index * 8; + Reloc_section* rela_dyn = this->rela_dyn_section(NULL); - if (this->dynbss_ == NULL) + this->got_->reserve_global(got_index, gsym, got_type); + switch (got_type) + { + case GOT_TYPE_STANDARD: + if (!gsym->final_value_is_known()) { - this->dynbss_ = new Output_data_space(align); - layout->add_output_section_data(".bss", - elfcpp::SHT_NOBITS, - (elfcpp::SHF_ALLOC - | elfcpp::SHF_WRITE), - this->dynbss_); + if (gsym->is_from_dynobj() + || gsym->is_undefined() + || gsym->is_preemptible() + || gsym->type() == elfcpp::STT_GNU_IFUNC) + rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT, + this->got_, got_offset, 0); + else + rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE, + this->got_, got_offset, 0, false); } + break; + case GOT_TYPE_TLS_OFFSET: + rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64, + this->got_, got_offset, 0, false); + break; + case GOT_TYPE_TLS_PAIR: + this->got_->reserve_slot(got_index + 1); + rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64, + this->got_, got_offset, 0, false); + rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64, + this->got_, got_offset + 8, 0, false); + break; + case GOT_TYPE_TLS_DESC: + this->got_->reserve_slot(got_index + 1); + rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC, + this->got_, got_offset, 0, false); + break; + default: + gold_unreachable(); + } +} + +// Register an existing PLT entry for a global symbol. - Output_data_space* dynbss = this->dynbss_; +template +void +Target_x86_64::register_global_plt_entry(Symbol_table* symtab, + Layout* layout, + unsigned int plt_index, + Symbol* gsym) +{ + gold_assert(this->plt_ != NULL); + gold_assert(!gsym->has_plt_offset()); + + this->plt_->reserve_slot(plt_index); - if (align > dynbss->addralign()) - dynbss->set_space_alignment(align); + gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size()); - off_t dynbss_size = dynbss->current_data_size(); - dynbss_size = align_address(dynbss_size, align); - off_t offset = dynbss_size; - dynbss->set_current_data_size(dynbss_size + symsize); + unsigned int got_offset = (plt_index + 3) * 8; + this->plt_->add_relocation(symtab, layout, gsym, got_offset); +} - symtab->define_with_copy_reloc(this, ssym, dynbss, offset); +// Force a COPY relocation for a given symbol. - // Add the COPY reloc. - Reloc_section* rela_dyn = this->rela_dyn_section(layout); - rela_dyn->add_global(ssym, elfcpp::R_X86_64_COPY, dynbss, offset, 0); +template +void +Target_x86_64::emit_copy_reloc( + Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset) +{ + this->copy_relocs_.emit_copy_reloc(symtab, + symtab->get_sized_symbol(sym), + os, + offset, + this->rela_dyn_section(NULL)); +} + +// Define the _TLS_MODULE_BASE_ symbol in the TLS segment. + +template +void +Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, + Layout* layout) +{ + if (this->tls_base_symbol_defined_) + return; + + Output_segment* tls_segment = layout->tls_segment(); + if (tls_segment != NULL) + { + bool is_exec = parameters->options().output_is_executable(); + symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL, + Symbol_table::PREDEFINED, + tls_segment, 0, 0, + elfcpp::STT_TLS, + elfcpp::STB_LOCAL, + elfcpp::STV_HIDDEN, 0, + (is_exec + ? Symbol::SEGMENT_END + : Symbol::SEGMENT_START), + true); } + this->tls_base_symbol_defined_ = true; } +// Create the reserved PLT and GOT entries for the TLS descriptor resolver. + +template +void +Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab, + Layout* layout) +{ + if (this->plt_ == NULL) + this->make_plt_section(symtab, layout); + + if (!this->plt_->has_tlsdesc_entry()) + { + // Allocate the TLSDESC_GOT entry. + Output_data_got<64, false>* got = this->got_section(symtab, layout); + unsigned int got_offset = got->add_constant(0); + + // Allocate the TLSDESC_PLT entry. + this->plt_->reserve_tlsdesc_entry(got_offset); + } +} + +// Create a GOT entry for the TLS module index. + +template +unsigned int +Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout, + Sized_relobj_file* object) +{ + if (this->got_mod_index_offset_ == -1U) + { + gold_assert(symtab != NULL && layout != NULL && object != NULL); + Reloc_section* rela_dyn = this->rela_dyn_section(layout); + Output_data_got<64, false>* got = this->got_section(symtab, layout); + unsigned int got_offset = got->add_constant(0); + rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got, + got_offset, 0); + got->add_constant(0); + this->got_mod_index_offset_ = got_offset; + } + return this->got_mod_index_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. +template tls::Tls_optimization -Target_x86_64::optimize_tls_reloc(bool is_final, int r_type) +Target_x86_64::optimize_tls_reloc(bool is_final, int r_type) { // If we are generating a shared library, then we can't do anything // in the linker. - if (parameters->output_is_shared()) + if (parameters->options().shared()) return tls::TLSOPT_NONE; switch (r_type) @@ -725,80 +2158,314 @@ Target_x86_64::optimize_tls_reloc(bool is_final, int r_type) } } -// Report an unsupported relocation against a local symbol. - -void -Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj<64, false>* object, - unsigned int r_type) -{ - gold_error(_("%s: unsupported reloc %u against local symbol"), - object->name().c_str(), r_type); -} - -// Scan a relocation for a local symbol. +// Get the Reference_flags for a particular relocation. -inline void -Target_x86_64::Scan::local(const General_options&, - Symbol_table* symtab, - Layout* layout, - Target_x86_64* target, - Sized_relobj<64, false>* object, - unsigned int data_shndx, - Output_section* output_section, - const elfcpp::Rela<64, false>& reloc, - unsigned int r_type, - const elfcpp::Sym<64, false>& lsym) +template +int +Target_x86_64::Scan::get_reference_flags(unsigned int r_type) { switch (r_type) { case elfcpp::R_X86_64_NONE: - case elfcpp::R_386_GNU_VTINHERIT: - case elfcpp::R_386_GNU_VTENTRY: - break; + case elfcpp::R_X86_64_GNU_VTINHERIT: + case elfcpp::R_X86_64_GNU_VTENTRY: + case elfcpp::R_X86_64_GOTPC32: + case elfcpp::R_X86_64_GOTPC64: + // No symbol reference. + return 0; case elfcpp::R_X86_64_64: - // 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_386_RELATIVE relocation so the dynamic loader can - // relocate it easily. - if (parameters->output_is_position_independent()) - { - Reloc_section* rela_dyn = target->rela_dyn_section(layout); - rela_dyn->add_local(object, 0, elfcpp::R_X86_64_RELATIVE, - output_section, data_shndx, - reloc.get_r_offset(), 0); - } - break; - case elfcpp::R_X86_64_32: case elfcpp::R_X86_64_32S: case elfcpp::R_X86_64_16: case elfcpp::R_X86_64_8: + return Symbol::ABSOLUTE_REF; + + case elfcpp::R_X86_64_PC64: + case elfcpp::R_X86_64_PC32: + case elfcpp::R_X86_64_PC32_BND: + case elfcpp::R_X86_64_PC16: + case elfcpp::R_X86_64_PC8: + case elfcpp::R_X86_64_GOTOFF64: + return Symbol::RELATIVE_REF; + + case elfcpp::R_X86_64_PLT32: + case elfcpp::R_X86_64_PLT32_BND: + case elfcpp::R_X86_64_PLTOFF64: + return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF; + + case elfcpp::R_X86_64_GOT64: + case elfcpp::R_X86_64_GOT32: + case elfcpp::R_X86_64_GOTPCREL64: + case elfcpp::R_X86_64_GOTPCREL: + case elfcpp::R_X86_64_GOTPCRELX: + case elfcpp::R_X86_64_REX_GOTPCRELX: + case elfcpp::R_X86_64_GOTPLT64: + // Absolute in GOT. + return Symbol::ABSOLUTE_REF; + + case elfcpp::R_X86_64_TLSGD: // Global-dynamic + case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url) + case elfcpp::R_X86_64_TLSDESC_CALL: + case elfcpp::R_X86_64_TLSLD: // Local-dynamic + case elfcpp::R_X86_64_DTPOFF32: + case elfcpp::R_X86_64_DTPOFF64: + case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec + case elfcpp::R_X86_64_TPOFF32: // Local-exec + return Symbol::TLS_REF; + + case elfcpp::R_X86_64_COPY: + case elfcpp::R_X86_64_GLOB_DAT: + case elfcpp::R_X86_64_JUMP_SLOT: + case elfcpp::R_X86_64_RELATIVE: + case elfcpp::R_X86_64_IRELATIVE: + case elfcpp::R_X86_64_TPOFF64: + case elfcpp::R_X86_64_DTPMOD64: + case elfcpp::R_X86_64_TLSDESC: + case elfcpp::R_X86_64_SIZE32: + case elfcpp::R_X86_64_SIZE64: + default: + // Not expected. We will give an error later. + return 0; + } +} + +// Report an unsupported relocation against a local symbol. + +template +void +Target_x86_64::Scan::unsupported_reloc_local( + Sized_relobj_file* 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. If GSYM is not NULL, +// it is the symbol the relocation is against; if it is NULL, the +// relocation is against a local symbol. + +template +void +Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type, + Symbol* gsym) +{ + switch (r_type) + { + // These are the relocation types supported by glibc for x86_64 + // which should always work. + case elfcpp::R_X86_64_RELATIVE: + case elfcpp::R_X86_64_IRELATIVE: + case elfcpp::R_X86_64_GLOB_DAT: + case elfcpp::R_X86_64_JUMP_SLOT: + case elfcpp::R_X86_64_DTPMOD64: + case elfcpp::R_X86_64_DTPOFF64: + case elfcpp::R_X86_64_TPOFF64: + case elfcpp::R_X86_64_64: + case elfcpp::R_X86_64_COPY: + return; + + // glibc supports these reloc types, but they can overflow. + case elfcpp::R_X86_64_PC32: + case elfcpp::R_X86_64_PC32_BND: + // A PC relative reference is OK against a local symbol or if + // the symbol is defined locally. + if (gsym == NULL + || (!gsym->is_from_dynobj() + && !gsym->is_undefined() + && !gsym->is_preemptible())) + return; + /* Fall through. */ + case elfcpp::R_X86_64_32: + // R_X86_64_32 is OK for x32. + if (size == 32 && r_type == elfcpp::R_X86_64_32) + return; + if (this->issued_non_pic_error_) + return; + gold_assert(parameters->options().output_is_position_independent()); + if (gsym == NULL) + object->error(_("requires dynamic R_X86_64_32 reloc which may " + "overflow at runtime; recompile with -fPIC")); + else + { + const char *r_name; + switch (r_type) + { + case elfcpp::R_X86_64_32: + r_name = "R_X86_64_32"; + break; + case elfcpp::R_X86_64_PC32: + r_name = "R_X86_64_PC32"; + break; + case elfcpp::R_X86_64_PC32_BND: + r_name = "R_X86_64_PC32_BND"; + break; + default: + gold_unreachable(); + break; + } + object->error(_("requires dynamic %s reloc against '%s' " + "which may overflow at runtime; recompile " + "with -fPIC"), + r_name, gsym->name()); + } + this->issued_non_pic_error_ = true; + 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; + gold_assert(parameters->options().output_is_position_independent()); + object->error(_("requires unsupported dynamic reloc %u; " + "recompile with -fPIC"), + r_type); + this->issued_non_pic_error_ = true; + return; + + case elfcpp::R_X86_64_NONE: + gold_unreachable(); + } +} + +// Return whether we need to make a PLT entry for a relocation of the +// given type against a STT_GNU_IFUNC symbol. + +template +bool +Target_x86_64::Scan::reloc_needs_plt_for_ifunc( + Sized_relobj_file* object, + unsigned int r_type) +{ + int flags = Scan::get_reference_flags(r_type); + if (flags & Symbol::TLS_REF) + gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"), + object->name().c_str(), r_type); + return flags != 0; +} + +// Scan a relocation for a local symbol. + +template +inline void +Target_x86_64::Scan::local(Symbol_table* symtab, + Layout* layout, + Target_x86_64* target, + Sized_relobj_file* object, + unsigned int data_shndx, + Output_section* output_section, + const elfcpp::Rela& reloc, + unsigned int r_type, + const elfcpp::Sym& lsym, + bool is_discarded) +{ + if (is_discarded) + return; + + // A local STT_GNU_IFUNC symbol may require a PLT entry. + bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC; + if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type)) + { + unsigned int r_sym = elfcpp::elf_r_sym(reloc.get_r_info()); + target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym); + } + + switch (r_type) + { + case elfcpp::R_X86_64_NONE: + case elfcpp::R_X86_64_GNU_VTINHERIT: + case elfcpp::R_X86_64_GNU_VTENTRY: + break; + + case elfcpp::R_X86_64_64: // 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_386_RELATIVE relocation so the dynamic loader can + // 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_X86_64_RELATIVE relocation so the dynamic loader can // relocate it easily. - if (parameters->output_is_position_independent()) - { - Reloc_section* rela_dyn = target->rela_dyn_section(layout); - unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info()); - rela_dyn->add_local(object, r_sym, r_type, output_section, - data_shndx, reloc.get_r_offset(), - reloc.get_r_addend()); - } + if (parameters->options().output_is_position_independent()) + { + unsigned int r_sym = elfcpp::elf_r_sym(reloc.get_r_info()); + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + rela_dyn->add_local_relative(object, r_sym, + (size == 32 + ? elfcpp::R_X86_64_RELATIVE64 + : elfcpp::R_X86_64_RELATIVE), + output_section, data_shndx, + reloc.get_r_offset(), + reloc.get_r_addend(), is_ifunc); + } + break; + + case elfcpp::R_X86_64_32: + case elfcpp::R_X86_64_32S: + case elfcpp::R_X86_64_16: + case elfcpp::R_X86_64_8: + // If building a shared library (or a position-independent + // executable), we need to create a dynamic relocation for this + // location. We can't use an R_X86_64_RELATIVE relocation + // because that is always a 64-bit relocation. + if (parameters->options().output_is_position_independent()) + { + // Use R_X86_64_RELATIVE relocation for R_X86_64_32 under x32. + if (size == 32 && r_type == elfcpp::R_X86_64_32) + { + unsigned int r_sym = elfcpp::elf_r_sym(reloc.get_r_info()); + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + rela_dyn->add_local_relative(object, r_sym, + elfcpp::R_X86_64_RELATIVE, + output_section, data_shndx, + reloc.get_r_offset(), + reloc.get_r_addend(), is_ifunc); + break; + } + + this->check_non_pic(object, r_type, NULL); + + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + unsigned int r_sym = elfcpp::elf_r_sym(reloc.get_r_info()); + if (lsym.get_st_type() != elfcpp::STT_SECTION) + rela_dyn->add_local(object, r_sym, r_type, output_section, + data_shndx, reloc.get_r_offset(), + reloc.get_r_addend()); + else + { + gold_assert(lsym.get_st_value() == 0); + unsigned int shndx = lsym.get_st_shndx(); + bool is_ordinary; + shndx = object->adjust_sym_shndx(r_sym, shndx, + &is_ordinary); + if (!is_ordinary) + object->error(_("section symbol %u has bad shndx %u"), + r_sym, shndx); + else + rela_dyn->add_local_section(object, shndx, + r_type, output_section, + data_shndx, reloc.get_r_offset(), + reloc.get_r_addend()); + } + } break; case elfcpp::R_X86_64_PC64: case elfcpp::R_X86_64_PC32: + case elfcpp::R_X86_64_PC32_BND: case elfcpp::R_X86_64_PC16: case elfcpp::R_X86_64_PC8: break; case elfcpp::R_X86_64_PLT32: + case elfcpp::R_X86_64_PLT32_BND: // Since we know this is a local symbol, we can handle this as a // PC32 reloc. break; @@ -817,29 +2484,72 @@ Target_x86_64::Scan::local(const General_options&, case elfcpp::R_X86_64_GOT32: case elfcpp::R_X86_64_GOTPCREL64: case elfcpp::R_X86_64_GOTPCREL: + case elfcpp::R_X86_64_GOTPCRELX: + case elfcpp::R_X86_64_REX_GOTPCRELX: case elfcpp::R_X86_64_GOTPLT64: { - // The symbol requires a GOT entry. - Output_data_got<64, false>* got = target->got_section(symtab, layout); - unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info()); - if (got->add_local(object, r_sym)) - { - // If we are generating a shared object, we need to add a - // dynamic relocation for this symbol's GOT entry. - if (parameters->output_is_position_independent()) - { - Reloc_section* rela_dyn = target->rela_dyn_section(layout); + // The symbol requires a GOT section. + Output_data_got<64, false>* got = target->got_section(symtab, layout); + + // If the relocation symbol isn't IFUNC, + // and is local, then we will convert + // mov foo@GOTPCREL(%rip), %reg + // to lea foo(%rip), %reg. + // in Relocate::relocate. + if ((r_type == elfcpp::R_X86_64_GOTPCREL + || r_type == elfcpp::R_X86_64_GOTPCRELX + || r_type == elfcpp::R_X86_64_REX_GOTPCRELX) + && reloc.get_r_offset() >= 2 + && !is_ifunc) + { + section_size_type stype; + const unsigned char* view = object->section_contents(data_shndx, + &stype, true); + if (view[reloc.get_r_offset() - 2] == 0x8b) + break; + } + + + // The symbol requires a GOT entry. + unsigned int r_sym = elfcpp::elf_r_sym(reloc.get_r_info()); + + // For a STT_GNU_IFUNC symbol we want the PLT offset. That + // lets function pointers compare correctly with shared + // libraries. Otherwise we would need an IRELATIVE reloc. + bool is_new; + if (is_ifunc) + is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD); + else + is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD); + if (is_new) + { + // If we are generating a shared object, we need to add a + // dynamic relocation for this symbol's GOT entry. + if (parameters->options().output_is_position_independent()) + { + Reloc_section* rela_dyn = target->rela_dyn_section(layout); // R_X86_64_RELATIVE assumes a 64-bit relocation. if (r_type != elfcpp::R_X86_64_GOT32) - rela_dyn->add_local(object, 0, elfcpp::R_X86_64_RELATIVE, - got, object->local_got_offset(r_sym), 0); - else - rela_dyn->add_local(object, r_sym, r_type, - got, object->local_got_offset(r_sym), 0); - } - } - // For GOTPLT64, we'd normally want a PLT section, but since - // we know this is a local symbol, no PLT is needed. + { + unsigned int got_offset = + object->local_got_offset(r_sym, GOT_TYPE_STANDARD); + rela_dyn->add_local_relative(object, r_sym, + elfcpp::R_X86_64_RELATIVE, + got, got_offset, 0, is_ifunc); + } + else + { + this->check_non_pic(object, r_type, NULL); + + gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION); + rela_dyn->add_local( + object, r_sym, r_type, got, + object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0); + } + } + } + // For GOTPLT64, we'd normally want a PLT section, but since + // we know this is a local symbol, no PLT is needed. } break; @@ -847,6 +2557,7 @@ Target_x86_64::Scan::local(const General_options&, case elfcpp::R_X86_64_GLOB_DAT: case elfcpp::R_X86_64_JUMP_SLOT: case elfcpp::R_X86_64_RELATIVE: + case elfcpp::R_X86_64_IRELATIVE: // These are outstanding tls relocs, which are unexpected when linking case elfcpp::R_X86_64_TPOFF64: case elfcpp::R_X86_64_DTPMOD64: @@ -865,78 +2576,113 @@ Target_x86_64::Scan::local(const General_options&, case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec case elfcpp::R_X86_64_TPOFF32: // Local-exec { - bool output_is_shared = parameters->output_is_shared(); + bool output_is_shared = parameters->options().shared(); const tls::Tls_optimization optimized_type - = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type); + = Target_x86_64::optimize_tls_reloc(!output_is_shared, + r_type); switch (r_type) { - case elfcpp::R_X86_64_TLSGD: // General-dynamic - if (optimized_type == tls::TLSOPT_NONE) - { - // Create a pair of GOT entries for the module index and - // dtv-relative offset. - Output_data_got<64, false>* got - = target->got_section(symtab, layout); - unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info()); - got->add_local_tls_with_rela(object, r_sym, - lsym.get_st_shndx(), true, - target->rela_dyn_section(layout), - elfcpp::R_X86_64_DTPMOD64); - } - else if (optimized_type != tls::TLSOPT_TO_LE) + case elfcpp::R_X86_64_TLSGD: // General-dynamic + if (optimized_type == tls::TLSOPT_NONE) + { + // Create a pair of GOT entries for the module index and + // dtv-relative offset. + Output_data_got<64, false>* got + = target->got_section(symtab, layout); + unsigned int r_sym = elfcpp::elf_r_sym(reloc.get_r_info()); + unsigned int shndx = lsym.get_st_shndx(); + bool is_ordinary; + shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary); + if (!is_ordinary) + object->error(_("local symbol %u has bad shndx %u"), + r_sym, shndx); + else + got->add_local_pair_with_rel(object, r_sym, + shndx, + GOT_TYPE_TLS_PAIR, + target->rela_dyn_section(layout), + elfcpp::R_X86_64_DTPMOD64); + } + else if (optimized_type != tls::TLSOPT_TO_LE) unsupported_reloc_local(object, r_type); - break; + break; - case elfcpp::R_X86_64_GOTPC32_TLSDESC: - case elfcpp::R_X86_64_TLSDESC_CALL: - // FIXME: If not relaxing to LE, we need to generate - // a GOT entry with a R_x86_64_TLSDESC reloc. - if (optimized_type != tls::TLSOPT_TO_LE) + case elfcpp::R_X86_64_GOTPC32_TLSDESC: + target->define_tls_base_symbol(symtab, layout); + if (optimized_type == tls::TLSOPT_NONE) + { + // Create reserved PLT and GOT entries for the resolver. + target->reserve_tlsdesc_entries(symtab, layout); + + // Generate a double GOT entry with an + // R_X86_64_TLSDESC reloc. The R_X86_64_TLSDESC reloc + // is resolved lazily, so the GOT entry needs to be in + // an area in .got.plt, not .got. Call got_section to + // make sure the section has been created. + target->got_section(symtab, layout); + Output_data_got<64, false>* got = target->got_tlsdesc_section(); + unsigned int r_sym = elfcpp::elf_r_sym(reloc.get_r_info()); + if (!object->local_has_got_offset(r_sym, GOT_TYPE_TLS_DESC)) + { + unsigned int got_offset = got->add_constant(0); + got->add_constant(0); + object->set_local_got_offset(r_sym, GOT_TYPE_TLS_DESC, + got_offset); + Reloc_section* rt = target->rela_tlsdesc_section(layout); + // We store the arguments we need in a vector, and + // use the index into the vector as the parameter + // to pass to the target specific routines. + uintptr_t intarg = target->add_tlsdesc_info(object, r_sym); + void* arg = reinterpret_cast(intarg); + rt->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg, + got, got_offset, 0); + } + } + else if (optimized_type != tls::TLSOPT_TO_LE) unsupported_reloc_local(object, r_type); break; - case elfcpp::R_X86_64_TLSLD: // Local-dynamic + case elfcpp::R_X86_64_TLSDESC_CALL: + break; + + case elfcpp::R_X86_64_TLSLD: // Local-dynamic if (optimized_type == tls::TLSOPT_NONE) { - // Create a GOT entry for the module index. - Output_data_got<64, false>* got - = target->got_section(symtab, layout); - unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info()); - got->add_local_tls_with_rela(object, r_sym, - lsym.get_st_shndx(), false, - target->rela_dyn_section(layout), - elfcpp::R_X86_64_DTPMOD64); + // Create a GOT entry for the module index. + target->got_mod_index_entry(symtab, layout, object); } else if (optimized_type != tls::TLSOPT_TO_LE) unsupported_reloc_local(object, r_type); break; - case elfcpp::R_X86_64_DTPOFF32: - case elfcpp::R_X86_64_DTPOFF64: + case elfcpp::R_X86_64_DTPOFF32: + case elfcpp::R_X86_64_DTPOFF64: + break; + + case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec + layout->set_has_static_tls(); + if (optimized_type == tls::TLSOPT_NONE) + { + // Create a GOT entry for the tp-relative offset. + Output_data_got<64, false>* got + = target->got_section(symtab, layout); + unsigned int r_sym = elfcpp::elf_r_sym(reloc.get_r_info()); + got->add_local_with_rel(object, r_sym, GOT_TYPE_TLS_OFFSET, + target->rela_dyn_section(layout), + elfcpp::R_X86_64_TPOFF64); + } + else if (optimized_type != tls::TLSOPT_TO_LE) + unsupported_reloc_local(object, r_type); break; - case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec - if (optimized_type == tls::TLSOPT_NONE) - { - // Create a GOT entry for the tp-relative offset. - Output_data_got<64, false>* got - = target->got_section(symtab, layout); - unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info()); - got->add_local_with_rela(object, r_sym, - target->rela_dyn_section(layout), - elfcpp::R_X86_64_TPOFF64); - } - else if (optimized_type != tls::TLSOPT_TO_LE) - unsupported_reloc_local(object, r_type); - break; - - case elfcpp::R_X86_64_TPOFF32: // Local-exec - if (output_is_shared) - unsupported_reloc_local(object, r_type); + case elfcpp::R_X86_64_TPOFF32: // Local-exec + layout->set_has_static_tls(); + if (output_is_shared) + unsupported_reloc_local(object, r_type); break; - default: - gold_unreachable(); + default: + gold_unreachable(); } } break; @@ -953,34 +2699,117 @@ Target_x86_64::Scan::local(const General_options&, // Report an unsupported relocation against a global symbol. +template void -Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj<64, false>* object, - unsigned int r_type, - Symbol* gsym) +Target_x86_64::Scan::unsupported_reloc_global( + Sized_relobj_file* 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()); } +// Returns true if this relocation type could be that of a function pointer. +template +inline bool +Target_x86_64::Scan::possible_function_pointer_reloc(unsigned int r_type) +{ + switch (r_type) + { + case elfcpp::R_X86_64_64: + case elfcpp::R_X86_64_32: + case elfcpp::R_X86_64_32S: + case elfcpp::R_X86_64_16: + case elfcpp::R_X86_64_8: + case elfcpp::R_X86_64_GOT64: + case elfcpp::R_X86_64_GOT32: + case elfcpp::R_X86_64_GOTPCREL64: + case elfcpp::R_X86_64_GOTPCREL: + case elfcpp::R_X86_64_GOTPCRELX: + case elfcpp::R_X86_64_REX_GOTPCRELX: + case elfcpp::R_X86_64_GOTPLT64: + { + return true; + } + } + return false; +} + +// For safe ICF, scan a relocation for a local symbol to check if it +// corresponds to a function pointer being taken. In that case mark +// the function whose pointer was taken as not foldable. + +template +inline bool +Target_x86_64::Scan::local_reloc_may_be_function_pointer( + Symbol_table* , + Layout* , + Target_x86_64* , + Sized_relobj_file* , + unsigned int , + Output_section* , + const elfcpp::Rela& , + unsigned int r_type, + const elfcpp::Sym&) +{ + // When building a shared library, do not fold any local symbols as it is + // not possible to distinguish pointer taken versus a call by looking at + // the relocation types. + return (parameters->options().shared() + || possible_function_pointer_reloc(r_type)); +} + +// For safe ICF, scan a relocation for a global symbol to check if it +// corresponds to a function pointer being taken. In that case mark +// the function whose pointer was taken as not foldable. + +template +inline bool +Target_x86_64::Scan::global_reloc_may_be_function_pointer( + Symbol_table*, + Layout* , + Target_x86_64* , + Sized_relobj_file* , + unsigned int , + Output_section* , + const elfcpp::Rela& , + unsigned int r_type, + Symbol* gsym) +{ + // When building a shared library, do not fold symbols whose visibility + // is hidden, internal or protected. + return ((parameters->options().shared() + && (gsym->visibility() == elfcpp::STV_INTERNAL + || gsym->visibility() == elfcpp::STV_PROTECTED + || gsym->visibility() == elfcpp::STV_HIDDEN)) + || possible_function_pointer_reloc(r_type)); +} + // Scan a relocation for a global symbol. +template inline void -Target_x86_64::Scan::global(const General_options& options, - Symbol_table* symtab, - Layout* layout, - Target_x86_64* target, - Sized_relobj<64, false>* object, - unsigned int data_shndx, - Output_section* output_section, - const elfcpp::Rela<64, false>& reloc, - unsigned int r_type, - Symbol* gsym) +Target_x86_64::Scan::global(Symbol_table* symtab, + Layout* layout, + Target_x86_64* target, + Sized_relobj_file* object, + unsigned int data_shndx, + Output_section* output_section, + const elfcpp::Rela& reloc, + unsigned int r_type, + Symbol* gsym) { + // A STT_GNU_IFUNC symbol may require a PLT entry. + if (gsym->type() == elfcpp::STT_GNU_IFUNC + && this->reloc_needs_plt_for_ifunc(object, r_type)) + target->make_plt_entry(symtab, layout, gsym); + switch (r_type) { case elfcpp::R_X86_64_NONE: - case elfcpp::R_386_GNU_VTINHERIT: - case elfcpp::R_386_GNU_VTENTRY: + case elfcpp::R_X86_64_GNU_VTINHERIT: + case elfcpp::R_X86_64_GNU_VTENTRY: break; case elfcpp::R_X86_64_64: @@ -989,69 +2818,97 @@ Target_x86_64::Scan::global(const General_options& options, case elfcpp::R_X86_64_16: case elfcpp::R_X86_64_8: { - // Make a PLT entry if necessary. - if (gsym->needs_plt_entry()) - { - target->make_plt_entry(symtab, layout, gsym); - // Since this is not a PC-relative relocation, we may be - // taking the address of a function. In that case we need to - // set the entry in the dynamic symbol table to the address of - // the PLT entry. - if (gsym->is_from_dynobj()) - gsym->set_needs_dynsym_value(); - } - // Make a dynamic relocation if necessary. - if (gsym->needs_dynamic_reloc(true, false)) - { - if (target->may_need_copy_reloc(gsym)) - { - target->copy_reloc(&options, symtab, layout, object, - data_shndx, output_section, gsym, reloc); - } - else if (r_type == elfcpp::R_X86_64_64 - && gsym->can_use_relative_reloc(false)) - { - Reloc_section* rela_dyn = target->rela_dyn_section(layout); - rela_dyn->add_local(object, 0, elfcpp::R_X86_64_RELATIVE, - output_section, data_shndx, - reloc.get_r_offset(), 0); - } - else - { - Reloc_section* rela_dyn = target->rela_dyn_section(layout); - rela_dyn->add_global(gsym, r_type, output_section, object, - data_shndx, reloc.get_r_offset(), - reloc.get_r_addend()); - } - } + // Make a PLT entry if necessary. + if (gsym->needs_plt_entry()) + { + target->make_plt_entry(symtab, layout, gsym); + // Since this is not a PC-relative relocation, we may be + // taking the address of a function. In that case we need to + // set the entry in the dynamic symbol table to the address of + // the PLT entry. + if (gsym->is_from_dynobj() && !parameters->options().shared()) + gsym->set_needs_dynsym_value(); + } + // Make a dynamic relocation if necessary. + if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))) + { + if (!parameters->options().output_is_position_independent() + && gsym->may_need_copy_reloc()) + { + target->copy_reloc(symtab, layout, object, + data_shndx, output_section, gsym, reloc); + } + else if (((size == 64 && r_type == elfcpp::R_X86_64_64) + || (size == 32 && r_type == elfcpp::R_X86_64_32)) + && gsym->type() == elfcpp::STT_GNU_IFUNC + && gsym->can_use_relative_reloc(false) + && !gsym->is_from_dynobj() + && !gsym->is_undefined() + && !gsym->is_preemptible()) + { + // Use an IRELATIVE reloc for a locally defined + // STT_GNU_IFUNC symbol. This makes a function + // address in a PIE executable match the address in a + // shared library that it links against. + Reloc_section* rela_dyn = + target->rela_irelative_section(layout); + unsigned int r_type = elfcpp::R_X86_64_IRELATIVE; + rela_dyn->add_symbolless_global_addend(gsym, r_type, + output_section, object, + data_shndx, + reloc.get_r_offset(), + reloc.get_r_addend()); + } + else if (((size == 64 && r_type == elfcpp::R_X86_64_64) + || (size == 32 && r_type == elfcpp::R_X86_64_32)) + && gsym->can_use_relative_reloc(false)) + { + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE, + output_section, object, + data_shndx, + reloc.get_r_offset(), + reloc.get_r_addend(), false); + } + else + { + this->check_non_pic(object, r_type, gsym); + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + rela_dyn->add_global(gsym, r_type, output_section, object, + data_shndx, reloc.get_r_offset(), + reloc.get_r_addend()); + } + } } break; case elfcpp::R_X86_64_PC64: case elfcpp::R_X86_64_PC32: + case elfcpp::R_X86_64_PC32_BND: case elfcpp::R_X86_64_PC16: case elfcpp::R_X86_64_PC8: { - // Make a PLT entry if necessary. - if (gsym->needs_plt_entry()) - target->make_plt_entry(symtab, layout, gsym); - // Make a dynamic relocation if necessary. - bool is_function_call = (gsym->type() == elfcpp::STT_FUNC); - if (gsym->needs_dynamic_reloc(false, is_function_call)) - { - if (target->may_need_copy_reloc(gsym)) - { - target->copy_reloc(&options, symtab, layout, object, - data_shndx, output_section, gsym, reloc); - } - else - { - Reloc_section* rela_dyn = target->rela_dyn_section(layout); - rela_dyn->add_global(gsym, r_type, output_section, object, - data_shndx, reloc.get_r_offset(), - reloc.get_r_addend()); - } - } + // Make a PLT entry if necessary. + if (gsym->needs_plt_entry()) + target->make_plt_entry(symtab, layout, gsym); + // Make a dynamic relocation if necessary. + if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type))) + { + if (parameters->options().output_is_executable() + && gsym->may_need_copy_reloc()) + { + target->copy_reloc(symtab, layout, object, + data_shndx, output_section, gsym, reloc); + } + else + { + this->check_non_pic(object, r_type, gsym); + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + rela_dyn->add_global(gsym, r_type, output_section, object, + data_shndx, reloc.get_r_offset(), + reloc.get_r_addend()); + } + } } break; @@ -1059,40 +2916,96 @@ Target_x86_64::Scan::global(const General_options& options, case elfcpp::R_X86_64_GOT32: case elfcpp::R_X86_64_GOTPCREL64: case elfcpp::R_X86_64_GOTPCREL: + case elfcpp::R_X86_64_GOTPCRELX: + case elfcpp::R_X86_64_REX_GOTPCRELX: case elfcpp::R_X86_64_GOTPLT64: { - // The symbol requires a GOT entry. - Output_data_got<64, false>* got = target->got_section(symtab, layout); - if (gsym->final_value_is_known()) - got->add_global(gsym); - else - { - // If this symbol is not fully resolved, we need to add a - // dynamic relocation for it. - Reloc_section* rela_dyn = target->rela_dyn_section(layout); - if (gsym->is_from_dynobj() || gsym->is_preemptible()) - got->add_global_with_rela(gsym, rela_dyn, - elfcpp::R_X86_64_GLOB_DAT); - else - { - if (got->add_global(gsym)) - { - rela_dyn->add_local(object, 0, elfcpp::R_X86_64_RELATIVE, - got, gsym->got_offset(), 0); - // Make sure we write the link-time value to the GOT. - gsym->set_needs_value_in_got(); - } - } - } - // For GOTPLT64, we also need a PLT entry (but only if the - // symbol is not fully resolved). - if (r_type == elfcpp::R_X86_64_GOTPLT64 - && !gsym->final_value_is_known()) - target->make_plt_entry(symtab, layout, gsym); + // The symbol requires a GOT entry. + Output_data_got<64, false>* got = target->got_section(symtab, layout); + + // If we convert this from + // mov foo@GOTPCREL(%rip), %reg + // to lea foo(%rip), %reg. + // in Relocate::relocate, then there is nothing to do here. + if ((r_type == elfcpp::R_X86_64_GOTPCREL + || r_type == elfcpp::R_X86_64_GOTPCRELX + || r_type == elfcpp::R_X86_64_REX_GOTPCRELX) + && reloc.get_r_offset() >= 2 + && Target_x86_64::can_convert_mov_to_lea(gsym)) + { + section_size_type stype; + const unsigned char* view = object->section_contents(data_shndx, + &stype, true); + if (view[reloc.get_r_offset() - 2] == 0x8b) + break; + } + + if (gsym->final_value_is_known()) + { + // For a STT_GNU_IFUNC symbol we want the PLT address. + if (gsym->type() == elfcpp::STT_GNU_IFUNC) + got->add_global_plt(gsym, GOT_TYPE_STANDARD); + else + got->add_global(gsym, GOT_TYPE_STANDARD); + } + else + { + // If this symbol is not fully resolved, we need to add a + // dynamic relocation for it. + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + + // Use a GLOB_DAT rather than a RELATIVE reloc if: + // + // 1) The symbol may be defined in some other module. + // + // 2) We are building a shared library and this is a + // protected symbol; using GLOB_DAT means that the dynamic + // linker can use the address of the PLT in the main + // executable when appropriate so that function address + // comparisons work. + // + // 3) This is a STT_GNU_IFUNC symbol in position dependent + // code, again so that function address comparisons work. + if (gsym->is_from_dynobj() + || gsym->is_undefined() + || gsym->is_preemptible() + || (gsym->visibility() == elfcpp::STV_PROTECTED + && parameters->options().shared()) + || (gsym->type() == elfcpp::STT_GNU_IFUNC + && parameters->options().output_is_position_independent())) + got->add_global_with_rel(gsym, GOT_TYPE_STANDARD, rela_dyn, + elfcpp::R_X86_64_GLOB_DAT); + else + { + // For a STT_GNU_IFUNC symbol we want to write the PLT + // offset into the GOT, so that function pointer + // comparisons work correctly. + bool is_new; + if (gsym->type() != elfcpp::STT_GNU_IFUNC) + is_new = got->add_global(gsym, GOT_TYPE_STANDARD); + else + { + is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD); + // Tell the dynamic linker to use the PLT address + // when resolving relocations. + if (gsym->is_from_dynobj() + && !parameters->options().shared()) + gsym->set_needs_dynsym_value(); + } + if (is_new) + { + unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD); + rela_dyn->add_global_relative(gsym, + elfcpp::R_X86_64_RELATIVE, + got, got_off, 0, false); + } + } + } } break; case elfcpp::R_X86_64_PLT32: + case elfcpp::R_X86_64_PLT32_BND: // If the symbol is fully resolved, this is just a PC32 reloc. // Otherwise we need a PLT entry. if (gsym->final_value_is_known()) @@ -1101,8 +3014,8 @@ Target_x86_64::Scan::global(const General_options& options, // 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()) + && !gsym->is_from_dynobj() + && !gsym->is_preemptible()) break; target->make_plt_entry(symtab, layout, gsym); break; @@ -1124,6 +3037,7 @@ Target_x86_64::Scan::global(const General_options& options, case elfcpp::R_X86_64_GLOB_DAT: case elfcpp::R_X86_64_JUMP_SLOT: case elfcpp::R_X86_64_RELATIVE: + case elfcpp::R_X86_64_IRELATIVE: // These are outstanding tls relocs, which are unexpected when linking case elfcpp::R_X86_64_TPOFF64: case elfcpp::R_X86_64_DTPMOD64: @@ -1142,83 +3056,112 @@ Target_x86_64::Scan::global(const General_options& options, case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec case elfcpp::R_X86_64_TPOFF32: // Local-exec { - const bool is_final = gsym->final_value_is_known(); + // For the Initial-Exec model, we can treat undef symbols as final + // when building an executable. + const bool is_final = (gsym->final_value_is_known() || + (r_type == elfcpp::R_X86_64_GOTTPOFF && + gsym->is_undefined() && + parameters->options().output_is_executable())); const tls::Tls_optimization optimized_type - = Target_x86_64::optimize_tls_reloc(is_final, r_type); + = Target_x86_64::optimize_tls_reloc(is_final, r_type); switch (r_type) { - case elfcpp::R_X86_64_TLSGD: // General-dynamic + case elfcpp::R_X86_64_TLSGD: // General-dynamic if (optimized_type == tls::TLSOPT_NONE) { - // Create a pair of GOT entries for the module index and - // dtv-relative offset. - Output_data_got<64, false>* got - = target->got_section(symtab, layout); - got->add_global_tls_with_rela(gsym, - target->rela_dyn_section(layout), - elfcpp::R_X86_64_DTPMOD64, - elfcpp::R_X86_64_DTPOFF64); + // Create a pair of GOT entries for the module index and + // dtv-relative offset. + Output_data_got<64, false>* got + = target->got_section(symtab, layout); + got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR, + target->rela_dyn_section(layout), + elfcpp::R_X86_64_DTPMOD64, + elfcpp::R_X86_64_DTPOFF64); } else if (optimized_type == tls::TLSOPT_TO_IE) { - // Create a GOT entry for the tp-relative offset. - Output_data_got<64, false>* got - = target->got_section(symtab, layout); - got->add_global_with_rela(gsym, - target->rela_dyn_section(layout), - elfcpp::R_X86_64_TPOFF64); + // Create a GOT entry for the tp-relative offset. + Output_data_got<64, false>* got + = target->got_section(symtab, layout); + got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET, + target->rela_dyn_section(layout), + elfcpp::R_X86_64_TPOFF64); } else if (optimized_type != tls::TLSOPT_TO_LE) unsupported_reloc_global(object, r_type, gsym); break; - case elfcpp::R_X86_64_GOTPC32_TLSDESC: - case elfcpp::R_X86_64_TLSDESC_CALL: - // FIXME: If not relaxing to LE, we need to generate - // DTPMOD64 and DTPOFF64, or TLSDESC, relocs. - if (optimized_type != tls::TLSOPT_TO_LE) + case elfcpp::R_X86_64_GOTPC32_TLSDESC: + target->define_tls_base_symbol(symtab, layout); + if (optimized_type == tls::TLSOPT_NONE) + { + // Create reserved PLT and GOT entries for the resolver. + target->reserve_tlsdesc_entries(symtab, layout); + + // Create a double GOT entry with an R_X86_64_TLSDESC + // reloc. The R_X86_64_TLSDESC reloc is resolved + // lazily, so the GOT entry needs to be in an area in + // .got.plt, not .got. Call got_section to make sure + // the section has been created. + target->got_section(symtab, layout); + Output_data_got<64, false>* got = target->got_tlsdesc_section(); + Reloc_section* rt = target->rela_tlsdesc_section(layout); + got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC, rt, + elfcpp::R_X86_64_TLSDESC, 0); + } + else if (optimized_type == tls::TLSOPT_TO_IE) + { + // Create a GOT entry for the tp-relative offset. + Output_data_got<64, false>* got + = target->got_section(symtab, layout); + got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET, + target->rela_dyn_section(layout), + elfcpp::R_X86_64_TPOFF64); + } + else if (optimized_type != tls::TLSOPT_TO_LE) unsupported_reloc_global(object, r_type, gsym); break; - case elfcpp::R_X86_64_TLSLD: // Local-dynamic + case elfcpp::R_X86_64_TLSDESC_CALL: + break; + + case elfcpp::R_X86_64_TLSLD: // Local-dynamic if (optimized_type == tls::TLSOPT_NONE) { - // Create a GOT entry for the module index. - Output_data_got<64, false>* got - = target->got_section(symtab, layout); - got->add_global_tls_with_rela(gsym, - target->rela_dyn_section(layout), - elfcpp::R_X86_64_DTPMOD64); + // Create a GOT entry for the module index. + target->got_mod_index_entry(symtab, layout, object); } else if (optimized_type != tls::TLSOPT_TO_LE) unsupported_reloc_global(object, r_type, gsym); break; - case elfcpp::R_X86_64_DTPOFF32: - case elfcpp::R_X86_64_DTPOFF64: + case elfcpp::R_X86_64_DTPOFF32: + case elfcpp::R_X86_64_DTPOFF64: break; - case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec - if (optimized_type == tls::TLSOPT_NONE) - { - // Create a GOT entry for the tp-relative offset. - Output_data_got<64, false>* got - = target->got_section(symtab, layout); - got->add_global_with_rela(gsym, - target->rela_dyn_section(layout), - elfcpp::R_X86_64_TPOFF64); - } - else if (optimized_type != tls::TLSOPT_TO_LE) - unsupported_reloc_global(object, r_type, gsym); - break; - - case elfcpp::R_X86_64_TPOFF32: // Local-exec - if (parameters->output_is_shared()) - unsupported_reloc_local(object, r_type); + case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec + layout->set_has_static_tls(); + if (optimized_type == tls::TLSOPT_NONE) + { + // Create a GOT entry for the tp-relative offset. + Output_data_got<64, false>* got + = target->got_section(symtab, layout); + got->add_global_with_rel(gsym, GOT_TYPE_TLS_OFFSET, + target->rela_dyn_section(layout), + elfcpp::R_X86_64_TPOFF64); + } + else if (optimized_type != tls::TLSOPT_TO_LE) + unsupported_reloc_global(object, r_type, gsym); + break; + + case elfcpp::R_X86_64_TPOFF32: // Local-exec + layout->set_has_static_tls(); + if (parameters->options().shared()) + unsupported_reloc_global(object, r_type, gsym); break; - default: - gold_unreachable(); + default: + gold_unreachable(); } } break; @@ -1228,26 +3171,62 @@ Target_x86_64::Scan::global(const General_options& options, default: gold_error(_("%s: unsupported reloc %u against global symbol %s"), object->name().c_str(), r_type, - gsym->demangled_name().c_str()); + gsym->demangled_name().c_str()); break; } } +template +void +Target_x86_64::gc_process_relocs(Symbol_table* symtab, + Layout* layout, + Sized_relobj_file* 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) +{ + + if (sh_type == elfcpp::SHT_REL) + { + return; + } + + gold::gc_process_relocs, elfcpp::SHT_RELA, + typename Target_x86_64::Scan, + typename Target_x86_64::Relocatable_size_for_reloc>( + 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 void -Target_x86_64::scan_relocs(const General_options& options, - Symbol_table* symtab, - Layout* layout, - Sized_relobj<64, false>* 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) +Target_x86_64::scan_relocs(Symbol_table* symtab, + Layout* layout, + Sized_relobj_file* 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) { if (sh_type == elfcpp::SHT_REL) { @@ -1256,9 +3235,8 @@ Target_x86_64::scan_relocs(const General_options& options, return; } - gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA, - Target_x86_64::Scan>( - options, + gold::scan_relocs, elfcpp::SHT_RELA, + typename Target_x86_64::Scan>( symtab, layout, this, @@ -1274,71 +3252,116 @@ Target_x86_64::scan_relocs(const General_options& options, // Finalize the sections. +template void -Target_x86_64::do_finalize_sections(Layout* layout) +Target_x86_64::do_finalize_sections( + Layout* layout, + const Input_objects*, + Symbol_table* symtab) { + const Reloc_section* rel_plt = (this->plt_ == NULL + ? NULL + : this->plt_->rela_plt()); + layout->add_target_dynamic_tags(false, this->got_plt_, rel_plt, + this->rela_dyn_, true, false); + // 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_RELA); - } - - if (this->rela_dyn_ != NULL) - { - const Output_data* od = this->rela_dyn_; - odyn->add_section_address(elfcpp::DT_RELA, od); - odyn->add_section_size(elfcpp::DT_RELASZ, od); - odyn->add_constant(elfcpp::DT_RELAENT, - elfcpp::Elf_sizes<64>::rela_size); - } - - if (!parameters->output_is_shared()) + if (this->plt_ != NULL + && this->plt_->output_section() != NULL + && this->plt_->has_tlsdesc_entry()) { - // 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); + unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset(); + unsigned int got_offset = this->plt_->get_tlsdesc_got_offset(); + this->got_->finalize_data_size(); + odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT, + this->plt_, plt_offset); + odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT, + this->got_, got_offset); } } // 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()) + if (this->copy_relocs_.any_saved_relocs()) + this->copy_relocs_.emit(this->rela_dyn_section(layout)); + + // Set the size of the _GLOBAL_OFFSET_TABLE_ symbol to the size of + // the .got.plt section. + Symbol* sym = this->global_offset_table_; + if (sym != NULL) { - Reloc_section* rela_dyn = this->rela_dyn_section(layout); - this->copy_relocs_->emit(rela_dyn); + uint64_t data_size = this->got_plt_->current_data_size(); + symtab->get_sized_symbol(sym)->set_symsize(data_size); + } + + if (parameters->doing_static_link() + && (this->plt_ == NULL || !this->plt_->has_irelative_section())) + { + // If linking statically, make sure that the __rela_iplt symbols + // were defined if necessary, even if we didn't create a PLT. + static const Define_symbol_in_segment syms[] = + { + { + "__rela_iplt_start", // name + elfcpp::PT_LOAD, // segment_type + elfcpp::PF_W, // segment_flags_set + elfcpp::PF(0), // segment_flags_clear + 0, // value + 0, // size + elfcpp::STT_NOTYPE, // type + elfcpp::STB_GLOBAL, // binding + elfcpp::STV_HIDDEN, // visibility + 0, // nonvis + Symbol::SEGMENT_START, // offset_from_base + true // only_if_ref + }, + { + "__rela_iplt_end", // name + elfcpp::PT_LOAD, // segment_type + elfcpp::PF_W, // segment_flags_set + elfcpp::PF(0), // segment_flags_clear + 0, // value + 0, // size + elfcpp::STT_NOTYPE, // type + elfcpp::STB_GLOBAL, // binding + elfcpp::STV_HIDDEN, // visibility + 0, // nonvis + Symbol::SEGMENT_START, // offset_from_base + true // only_if_ref + } + }; + + symtab->define_symbols(layout, 2, syms, + layout->script_options()->saw_sections_clause()); } - delete this->copy_relocs_; - this->copy_relocs_ = NULL; } // Perform a relocation. +template inline bool -Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, - Target_x86_64* target, - size_t relnum, - const elfcpp::Rela<64, false>& rela, - unsigned int r_type, - const Sized_symbol<64>* gsym, - const Symbol_value<64>* psymval, - unsigned char* view, - elfcpp::Elf_types<64>::Elf_Addr address, - off_t view_size) +Target_x86_64::Relocate::relocate( + const Relocate_info* relinfo, + Target_x86_64* target, + Output_section*, + size_t relnum, + const elfcpp::Rela& rela, + unsigned int r_type, + const Sized_symbol* gsym, + const Symbol_value* psymval, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size) { if (this->skip_call_tls_get_addr_) { - if (r_type != elfcpp::R_X86_64_PLT32 + if ((r_type != elfcpp::R_X86_64_PLT32 + && r_type != elfcpp::R_X86_64_PLT32_BND + && r_type != elfcpp::R_X86_64_PC32_BND + && r_type != elfcpp::R_X86_64_PC32) || gsym == NULL || strcmp(gsym->name(), "__tls_get_addr") != 0) { @@ -1352,20 +3375,29 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, } } - // Pick the value to use for symbols defined in shared objects. - Symbol_value<64> symval; + if (view == NULL) + return true; + + const Sized_relobj_file* object = relinfo->object; + + // Pick the value to use for symbols defined in the PLT. + Symbol_value symval; if (gsym != NULL - && (gsym->is_from_dynobj() - || (parameters->output_is_shared() - && gsym->is_preemptible())) - && gsym->has_plt_offset()) + && gsym->use_plt_offset(Scan::get_reference_flags(r_type))) { - symval.set_output_value(target->plt_section()->address() - + gsym->plt_offset()); + symval.set_output_value(target->plt_address_for_global(gsym)); psymval = &symval; } + else if (gsym == NULL && psymval->is_ifunc_symbol()) + { + unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); + if (object->local_has_plt_offset(r_sym)) + { + symval.set_output_value(target->plt_address_for_local(object, r_sym)); + psymval = &symval; + } + } - const Sized_relobj<64, false>* object = relinfo->object; const elfcpp::Elf_Xword addend = rela.get_r_addend(); // Get the GOT offset if needed. @@ -1373,25 +3405,27 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, // 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; + // Since the actual offset is always negative, we use signed int to + // support 64-bit GOT relocations. + int got_offset = 0; switch (r_type) { case elfcpp::R_X86_64_GOT32: case elfcpp::R_X86_64_GOT64: case elfcpp::R_X86_64_GOTPLT64: - case elfcpp::R_X86_64_GOTPCREL: case elfcpp::R_X86_64_GOTPCREL64: if (gsym != NULL) - { - gold_assert(gsym->has_got_offset()); - got_offset = gsym->got_offset() - target->got_size(); - } - else - { - unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info()); - gold_assert(object->local_has_got_offset(r_sym)); - got_offset = object->local_got_offset(r_sym) - target->got_size(); - } + { + 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(rela.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; @@ -1402,17 +3436,17 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, switch (r_type) { case elfcpp::R_X86_64_NONE: - case elfcpp::R_386_GNU_VTINHERIT: - case elfcpp::R_386_GNU_VTENTRY: + case elfcpp::R_X86_64_GNU_VTINHERIT: + case elfcpp::R_X86_64_GNU_VTENTRY: break; case elfcpp::R_X86_64_64: - Relocate_functions<64, false>::rela64(view, object, psymval, addend); + Relocate_functions::rela64(view, object, psymval, addend); break; case elfcpp::R_X86_64_PC64: - Relocate_functions<64, false>::pcrela64(view, object, psymval, addend, - address); + Relocate_functions::pcrela64(view, object, psymval, addend, + address); break; case elfcpp::R_X86_64_32: @@ -1420,116 +3454,153 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, // uint64_t x = value + addend; // x == static_cast(static_cast(x)) // Likewise for other <=32-bit relocations (but see R_X86_64_32S). - Relocate_functions<64, false>::rela32(view, object, psymval, addend); + Relocate_functions::rela32(view, object, psymval, addend); break; case elfcpp::R_X86_64_32S: // FIXME: we need to verify that value + addend fits into 32 bits: // int64_t x = value + addend; // note this quantity is signed! // x == static_cast(static_cast(x)) - Relocate_functions<64, false>::rela32(view, object, psymval, addend); + Relocate_functions::rela32(view, object, psymval, addend); break; case elfcpp::R_X86_64_PC32: - Relocate_functions<64, false>::pcrela32(view, object, psymval, addend, - address); + case elfcpp::R_X86_64_PC32_BND: + Relocate_functions::pcrela32(view, object, psymval, addend, + address); break; case elfcpp::R_X86_64_16: - Relocate_functions<64, false>::rela16(view, object, psymval, addend); + Relocate_functions::rela16(view, object, psymval, addend); break; case elfcpp::R_X86_64_PC16: - Relocate_functions<64, false>::pcrela16(view, object, psymval, addend, - address); + Relocate_functions::pcrela16(view, object, psymval, addend, + address); break; case elfcpp::R_X86_64_8: - Relocate_functions<64, false>::rela8(view, object, psymval, addend); + Relocate_functions::rela8(view, object, psymval, addend); break; case elfcpp::R_X86_64_PC8: - Relocate_functions<64, false>::pcrela8(view, object, psymval, addend, - address); + Relocate_functions::pcrela8(view, object, psymval, addend, + address); break; case elfcpp::R_X86_64_PLT32: + case elfcpp::R_X86_64_PLT32_BND: gold_assert(gsym == NULL - || gsym->has_plt_offset() - || gsym->final_value_is_known()); + || gsym->has_plt_offset() + || gsym->final_value_is_known() + || (gsym->is_defined() + && !gsym->is_from_dynobj() + && !gsym->is_preemptible())); // Note: while this code looks the same as for R_X86_64_PC32, it // behaves differently because psymval was set to point to // the PLT entry, rather than the symbol, in Scan::global(). - Relocate_functions<64, false>::pcrela32(view, object, psymval, addend, - address); + Relocate_functions::pcrela32(view, object, psymval, addend, + address); break; case elfcpp::R_X86_64_PLTOFF64: { - gold_assert(gsym); - gold_assert(gsym->has_plt_offset() - || gsym->final_value_is_known()); - elfcpp::Elf_types<64>::Elf_Addr got_address; - got_address = target->got_section(NULL, NULL)->address(); - Relocate_functions<64, false>::rela64(view, object, psymval, - addend - got_address); + gold_assert(gsym); + gold_assert(gsym->has_plt_offset() + || gsym->final_value_is_known()); + typename elfcpp::Elf_types::Elf_Addr got_address; + // This is the address of GLOBAL_OFFSET_TABLE. + got_address = target->got_plt_section()->address(); + Relocate_functions::rela64(view, object, psymval, + addend - got_address); } + break; case elfcpp::R_X86_64_GOT32: gold_assert(have_got_offset); - Relocate_functions<64, false>::rela32(view, got_offset, addend); + Relocate_functions::rela32(view, got_offset, addend); break; case elfcpp::R_X86_64_GOTPC32: { - gold_assert(gsym); - elfcpp::Elf_types<64>::Elf_Addr value; + gold_assert(gsym); + typename elfcpp::Elf_types::Elf_Addr value; value = target->got_plt_section()->address(); - Relocate_functions<64, false>::pcrela32(view, value, addend, address); + Relocate_functions::pcrela32(view, value, addend, address); } break; case elfcpp::R_X86_64_GOT64: - // The ABI doc says "Like GOT64, but indicates a PLT entry is needed." - // Since we always add a PLT entry, this is equivalent. case elfcpp::R_X86_64_GOTPLT64: + // R_X86_64_GOTPLT64 is obsolete and treated the the same as + // GOT64. gold_assert(have_got_offset); - Relocate_functions<64, false>::rela64(view, got_offset, addend); + Relocate_functions::rela64(view, got_offset, addend); break; case elfcpp::R_X86_64_GOTPC64: { - gold_assert(gsym); - elfcpp::Elf_types<64>::Elf_Addr value; + gold_assert(gsym); + typename elfcpp::Elf_types::Elf_Addr value; value = target->got_plt_section()->address(); - Relocate_functions<64, false>::pcrela64(view, value, addend, address); + Relocate_functions::pcrela64(view, value, addend, address); } break; case elfcpp::R_X86_64_GOTOFF64: { - elfcpp::Elf_types<64>::Elf_Addr value; + typename elfcpp::Elf_types::Elf_Addr value; value = (psymval->value(object, 0) - target->got_plt_section()->address()); - Relocate_functions<64, false>::rela64(view, value, addend); + Relocate_functions::rela64(view, value, addend); } break; case elfcpp::R_X86_64_GOTPCREL: + case elfcpp::R_X86_64_GOTPCRELX: + case elfcpp::R_X86_64_REX_GOTPCRELX: { - gold_assert(have_got_offset); - elfcpp::Elf_types<64>::Elf_Addr value; - value = target->got_plt_section()->address() + got_offset; - Relocate_functions<64, false>::pcrela32(view, value, addend, address); + // Convert + // mov foo@GOTPCREL(%rip), %reg + // to lea foo(%rip), %reg. + // if possible. + if (rela.get_r_offset() >= 2 + && view[-2] == 0x8b + && ((gsym == NULL && !psymval->is_ifunc_symbol()) + || (gsym != NULL + && Target_x86_64::can_convert_mov_to_lea(gsym)))) + { + view[-2] = 0x8d; + Relocate_functions::pcrela32(view, object, psymval, addend, + address); + } + else + { + 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(rela.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()); + } + typename elfcpp::Elf_types::Elf_Addr value; + value = target->got_plt_section()->address() + got_offset; + Relocate_functions::pcrela32(view, value, addend, address); + } } break; case elfcpp::R_X86_64_GOTPCREL64: { - gold_assert(have_got_offset); - elfcpp::Elf_types<64>::Elf_Addr value; - value = target->got_plt_section()->address() + got_offset; - Relocate_functions<64, false>::pcrela64(view, value, addend, address); + gold_assert(have_got_offset); + typename elfcpp::Elf_types::Elf_Addr value; + value = target->got_plt_section()->address() + got_offset; + Relocate_functions::pcrela64(view, value, addend, address); } break; @@ -1537,6 +3608,7 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, case elfcpp::R_X86_64_GLOB_DAT: case elfcpp::R_X86_64_JUMP_SLOT: case elfcpp::R_X86_64_RELATIVE: + case elfcpp::R_X86_64_IRELATIVE: // These are outstanding tls relocs, which are unexpected when linking case elfcpp::R_X86_64_TPOFF64: case elfcpp::R_X86_64_DTPMOD64: @@ -1556,7 +3628,7 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec case elfcpp::R_X86_64_TPOFF32: // Local-exec this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval, - view, address, view_size); + view, address, view_size); break; case elfcpp::R_X86_64_SIZE32: @@ -1573,163 +3645,309 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, // Perform a TLS relocation. +template inline void -Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo, - Target_x86_64* target, - size_t relnum, - const elfcpp::Rela<64, false>& rela, - unsigned int r_type, - const Sized_symbol<64>* gsym, - const Symbol_value<64>* psymval, - unsigned char* view, - elfcpp::Elf_types<64>::Elf_Addr, - off_t view_size) +Target_x86_64::Relocate::relocate_tls( + const Relocate_info* relinfo, + Target_x86_64* target, + size_t relnum, + const elfcpp::Rela& rela, + unsigned int r_type, + const Sized_symbol* gsym, + const Symbol_value* psymval, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size) { Output_segment* tls_segment = relinfo->layout->tls_segment(); - const Sized_relobj<64, false>* object = relinfo->object; + const Sized_relobj_file* object = relinfo->object; + const elfcpp::Elf_Xword addend = rela.get_r_addend(); + elfcpp::Shdr data_shdr(relinfo->data_shdr); + bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0; - elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0); + typename elfcpp::Elf_types::Elf_Addr value = psymval->value(relinfo->object, 0); const bool is_final = (gsym == NULL - ? !parameters->output_is_position_independent() + ? !parameters->options().shared() : gsym->final_value_is_known()); - const tls::Tls_optimization optimized_type - = Target_x86_64::optimize_tls_reloc(is_final, r_type); + tls::Tls_optimization optimized_type + = Target_x86_64::optimize_tls_reloc(is_final, r_type); switch (r_type) { case elfcpp::R_X86_64_TLSGD: // Global-dynamic - case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url) - case elfcpp::R_X86_64_TLSDESC_CALL: + if (!is_executable && optimized_type == tls::TLSOPT_TO_LE) + { + // If this code sequence is used in a non-executable section, + // we will not optimize the R_X86_64_DTPOFF32/64 relocation, + // on the assumption that it's being used by itself in a debug + // section. Therefore, in the unlikely event that the code + // sequence appears in a non-executable section, we simply + // leave it unoptimized. + optimized_type = tls::TLSOPT_NONE; + } if (optimized_type == tls::TLSOPT_TO_LE) { - gold_assert(tls_segment != NULL); + if (tls_segment == NULL) + { + gold_assert(parameters->errors()->error_count() > 0 + || issue_undefined_symbol_error(gsym)); + return; + } this->tls_gd_to_le(relinfo, relnum, tls_segment, rela, r_type, value, view, view_size); break; } else - { - unsigned int got_offset; - if (gsym != NULL) - { - gold_assert(gsym->has_tls_got_offset(true)); - got_offset = gsym->tls_got_offset(true) - target->got_size(); - } - else - { - unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info()); - gold_assert(object->local_has_tls_got_offset(r_sym, true)); - got_offset = (object->local_tls_got_offset(r_sym, true) - - target->got_size()); - } - if (optimized_type == tls::TLSOPT_TO_IE) - { - gold_assert(tls_segment != NULL); - this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type, - got_offset, view, view_size); - break; - } - else if (optimized_type == tls::TLSOPT_NONE) - { - // Relocate the field with the offset of the pair of GOT - // entries. - Relocate_functions<64, false>::rel64(view, got_offset); - break; - } - } + { + unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE + ? GOT_TYPE_TLS_OFFSET + : GOT_TYPE_TLS_PAIR); + unsigned int got_offset; + if (gsym != NULL) + { + gold_assert(gsym->has_got_offset(got_type)); + got_offset = gsym->got_offset(got_type) - target->got_size(); + } + else + { + unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); + gold_assert(object->local_has_got_offset(r_sym, got_type)); + got_offset = (object->local_got_offset(r_sym, got_type) + - target->got_size()); + } + if (optimized_type == tls::TLSOPT_TO_IE) + { + value = target->got_plt_section()->address() + got_offset; + this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type, + value, view, address, view_size); + break; + } + else if (optimized_type == tls::TLSOPT_NONE) + { + // Relocate the field with the offset of the pair of GOT + // entries. + value = target->got_plt_section()->address() + got_offset; + Relocate_functions::pcrela32(view, value, addend, + address); + break; + } + } + gold_error_at_location(relinfo, relnum, rela.get_r_offset(), + _("unsupported reloc %u"), r_type); + break; + + case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url) + case elfcpp::R_X86_64_TLSDESC_CALL: + if (!is_executable && optimized_type == tls::TLSOPT_TO_LE) + { + // See above comment for R_X86_64_TLSGD. + optimized_type = tls::TLSOPT_NONE; + } + if (optimized_type == tls::TLSOPT_TO_LE) + { + if (tls_segment == NULL) + { + gold_assert(parameters->errors()->error_count() > 0 + || issue_undefined_symbol_error(gsym)); + return; + } + this->tls_desc_gd_to_le(relinfo, relnum, tls_segment, + rela, r_type, value, view, + view_size); + break; + } + else + { + unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE + ? GOT_TYPE_TLS_OFFSET + : GOT_TYPE_TLS_DESC); + unsigned int got_offset = 0; + if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC + && optimized_type == tls::TLSOPT_NONE) + { + // We created GOT entries in the .got.tlsdesc portion of + // the .got.plt section, but the offset stored in the + // symbol is the offset within .got.tlsdesc. + got_offset = (target->got_size() + + target->got_plt_section()->data_size()); + } + if (gsym != NULL) + { + gold_assert(gsym->has_got_offset(got_type)); + got_offset += gsym->got_offset(got_type) - target->got_size(); + } + else + { + unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); + gold_assert(object->local_has_got_offset(r_sym, got_type)); + got_offset += (object->local_got_offset(r_sym, got_type) + - target->got_size()); + } + if (optimized_type == tls::TLSOPT_TO_IE) + { + if (tls_segment == NULL) + { + gold_assert(parameters->errors()->error_count() > 0 + || issue_undefined_symbol_error(gsym)); + return; + } + value = target->got_plt_section()->address() + got_offset; + this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, + rela, r_type, value, view, address, + view_size); + break; + } + else if (optimized_type == tls::TLSOPT_NONE) + { + if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC) + { + // Relocate the field with the offset of the pair of GOT + // entries. + value = target->got_plt_section()->address() + got_offset; + Relocate_functions::pcrela32(view, value, addend, + address); + } + break; + } + } gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("unsupported reloc %u"), r_type); break; case elfcpp::R_X86_64_TLSLD: // Local-dynamic + if (!is_executable && optimized_type == tls::TLSOPT_TO_LE) + { + // See above comment for R_X86_64_TLSGD. + optimized_type = tls::TLSOPT_NONE; + } if (optimized_type == tls::TLSOPT_TO_LE) - { - gold_assert(tls_segment != NULL); + { + if (tls_segment == NULL) + { + gold_assert(parameters->errors()->error_count() > 0 + || issue_undefined_symbol_error(gsym)); + return; + } this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type, value, view, view_size); break; - } + } else if (optimized_type == tls::TLSOPT_NONE) - { - // Relocate the field with the offset of the GOT entry for - // the module index. - unsigned int got_offset; - if (gsym != NULL) - { - gold_assert(gsym->has_tls_got_offset(false)); - got_offset = gsym->tls_got_offset(false) - target->got_size(); - } - else - { - unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info()); - gold_assert(object->local_has_tls_got_offset(r_sym, false)); - got_offset = (object->local_tls_got_offset(r_sym, false) - - target->got_size()); - } - Relocate_functions<64, false>::rel64(view, got_offset); - break; - } + { + // Relocate the field with the offset of the GOT entry for + // the module index. + unsigned int got_offset; + got_offset = (target->got_mod_index_entry(NULL, NULL, NULL) + - target->got_size()); + value = target->got_plt_section()->address() + got_offset; + Relocate_functions::pcrela32(view, value, addend, + address); + break; + } gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("unsupported reloc %u"), r_type); break; case elfcpp::R_X86_64_DTPOFF32: - gold_assert(tls_segment != NULL); - if (optimized_type == tls::TLSOPT_TO_LE) - value = value - (tls_segment->vaddr() + tls_segment->memsz()); - else - value = value - tls_segment->vaddr(); - Relocate_functions<64, false>::rel32(view, value); + // This relocation type is used in debugging information. + // In that case we need to not optimize the value. If the + // section is not executable, then we assume we should not + // optimize this reloc. See comments above for R_X86_64_TLSGD, + // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and + // R_X86_64_TLSLD. + if (optimized_type == tls::TLSOPT_TO_LE && is_executable) + { + if (tls_segment == NULL) + { + gold_assert(parameters->errors()->error_count() > 0 + || issue_undefined_symbol_error(gsym)); + return; + } + value -= tls_segment->memsz(); + } + Relocate_functions::rela32(view, value, addend); break; case elfcpp::R_X86_64_DTPOFF64: - gold_assert(tls_segment != NULL); - if (optimized_type == tls::TLSOPT_TO_LE) - value = value - (tls_segment->vaddr() + tls_segment->memsz()); - else - value = value - tls_segment->vaddr(); - Relocate_functions<64, false>::rel64(view, value); + // See R_X86_64_DTPOFF32, just above, for why we check for is_executable. + if (optimized_type == tls::TLSOPT_TO_LE && is_executable) + { + if (tls_segment == NULL) + { + gold_assert(parameters->errors()->error_count() > 0 + || issue_undefined_symbol_error(gsym)); + return; + } + value -= tls_segment->memsz(); + } + Relocate_functions::rela64(view, value, addend); break; case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec - if (optimized_type == tls::TLSOPT_TO_LE) + if (gsym != NULL + && gsym->is_undefined() + && parameters->options().output_is_executable()) { - gold_assert(tls_segment != NULL); - Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, - rela, r_type, value, view, - view_size); + Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, + NULL, rela, + r_type, value, view, + view_size); + break; + } + else if (optimized_type == tls::TLSOPT_TO_LE) + { + if (tls_segment == NULL) + { + gold_assert(parameters->errors()->error_count() > 0 + || issue_undefined_symbol_error(gsym)); + return; + } + Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, + tls_segment, rela, + r_type, value, view, + view_size); break; } else if (optimized_type == tls::TLSOPT_NONE) - { - // Relocate the field with the offset of the GOT entry for - // the tp-relative offset of the symbol. - unsigned int got_offset; - if (gsym != NULL) - { - gold_assert(gsym->has_got_offset()); - got_offset = gsym->got_offset() - target->got_size(); - } - else - { - unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info()); - gold_assert(object->local_has_got_offset(r_sym)); - got_offset = (object->local_got_offset(r_sym) - - target->got_size()); - } - Relocate_functions<64, false>::rel64(view, got_offset); - break; - } + { + // Relocate the field with the offset of the GOT entry for + // the tp-relative offset of the symbol. + unsigned int got_offset; + if (gsym != NULL) + { + gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET)); + got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET) + - target->got_size()); + } + else + { + unsigned int r_sym = elfcpp::elf_r_sym(rela.get_r_info()); + gold_assert(object->local_has_got_offset(r_sym, + GOT_TYPE_TLS_OFFSET)); + got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET) + - target->got_size()); + } + value = target->got_plt_section()->address() + got_offset; + Relocate_functions::pcrela32(view, value, addend, + address); + break; + } gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("unsupported reloc type %u"), r_type); break; case elfcpp::R_X86_64_TPOFF32: // Local-exec - value = value - (tls_segment->vaddr() + tls_segment->memsz()); - Relocate_functions<64, false>::rel32(view, value); + if (tls_segment == NULL) + { + gold_assert(parameters->errors()->error_count() > 0 + || issue_undefined_symbol_error(gsym)); + return; + } + value -= tls_segment->memsz(); + Relocate_functions::rela32(view, value, addend); break; } } @@ -1737,32 +3955,54 @@ Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo, // Do a relocation in which we convert a TLS General-Dynamic to an // Initial-Exec. +template inline void -Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo, - size_t relnum, - Output_segment* tls_segment, - const elfcpp::Rela<64, false>& rela, - unsigned int, - elfcpp::Elf_types<64>::Elf_Addr value, - unsigned char* view, - off_t view_size) -{ - // .byte 0x66; leaq foo@tlsgd(%rip),%rdi; - // .word 0x6666; rex64; call __tls_get_addr - // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax - - tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4); - tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12); +Target_x86_64::Relocate::tls_gd_to_ie( + const Relocate_info* relinfo, + size_t relnum, + Output_segment*, + const elfcpp::Rela& rela, + unsigned int, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size) +{ + // For SIZE == 64: + // .byte 0x66; leaq foo@tlsgd(%rip),%rdi; + // .word 0x6666; rex64; call __tls_get_addr + // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax + // For SIZE == 32: + // leaq foo@tlsgd(%rip),%rdi; + // .word 0x6666; rex64; call __tls_get_addr + // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12); tls::check_tls(relinfo, relnum, rela.get_r_offset(), - (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0)); - tls::check_tls(relinfo, relnum, rela.get_r_offset(), - (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0)); + (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0)); - memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16); + if (size == 64) + { + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, + -4); + tls::check_tls(relinfo, relnum, rela.get_r_offset(), + (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0)); + memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", + 16); + } + else + { + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, + -3); + tls::check_tls(relinfo, relnum, rela.get_r_offset(), + (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0)); + memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", + 15); + } - value = value - (tls_segment->vaddr() + tls_segment->memsz()); - Relocate_functions<64, false>::rela32(view + 8, value, 0); + const elfcpp::Elf_Xword addend = rela.get_r_addend(); + Relocate_functions::pcrela32(view + 8, value, addend - 8, + address); // The next reloc should be a PLT32 reloc against __tls_get_addr. // We can skip it. @@ -1772,61 +4012,171 @@ Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo, // Do a relocation in which we convert a TLS General-Dynamic to a // Local-Exec. +template inline void -Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo, - size_t relnum, - Output_segment* tls_segment, - const elfcpp::Rela<64, false>& rela, - unsigned int, - elfcpp::Elf_types<64>::Elf_Addr value, - unsigned char* view, - off_t view_size) -{ - // .byte 0x66; leaq foo@tlsgd(%rip),%rdi; - // .word 0x6666; rex64; call __tls_get_addr - // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax - - tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4); - tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12); +Target_x86_64::Relocate::tls_gd_to_le( + const Relocate_info* relinfo, + size_t relnum, + Output_segment* tls_segment, + const elfcpp::Rela& rela, + unsigned int, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned char* view, + section_size_type view_size) +{ + // For SIZE == 64: + // .byte 0x66; leaq foo@tlsgd(%rip),%rdi; + // .word 0x6666; rex64; call __tls_get_addr + // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax + // For SIZE == 32: + // leaq foo@tlsgd(%rip),%rdi; + // .word 0x6666; rex64; call __tls_get_addr + // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12); tls::check_tls(relinfo, relnum, rela.get_r_offset(), - (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0)); - tls::check_tls(relinfo, relnum, rela.get_r_offset(), - (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0)); + (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0)); - memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16); + if (size == 64) + { + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, + -4); + tls::check_tls(relinfo, relnum, rela.get_r_offset(), + (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0)); + memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", + 16); + } + else + { + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, + -3); + tls::check_tls(relinfo, relnum, rela.get_r_offset(), + (memcmp(view - 3, "\x48\x8d\x3d", 3) == 0)); + + memcpy(view - 3, "\x64\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", + 15); + } - value = value - (tls_segment->vaddr() + tls_segment->memsz()); - Relocate_functions<64, false>::rela32(view + 8, value, 0); + value -= tls_segment->memsz(); + Relocate_functions::rela32(view + 8, value, 0); // The next reloc should be a PLT32 reloc against __tls_get_addr. // We can skip it. this->skip_call_tls_get_addr_ = true; } +// Do a TLSDESC-style General-Dynamic to Initial-Exec transition. + +template +inline void +Target_x86_64::Relocate::tls_desc_gd_to_ie( + const Relocate_info* relinfo, + size_t relnum, + Output_segment*, + const elfcpp::Rela& rela, + unsigned int r_type, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size) +{ + if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC) + { + // leaq foo@tlsdesc(%rip), %rax + // ==> movq foo@gottpoff(%rip), %rax + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3); + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4); + tls::check_tls(relinfo, relnum, rela.get_r_offset(), + view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05); + view[-2] = 0x8b; + const elfcpp::Elf_Xword addend = rela.get_r_addend(); + Relocate_functions::pcrela32(view, value, addend, address); + } + else + { + // call *foo@tlscall(%rax) + // ==> nop; nop + gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL); + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2); + tls::check_tls(relinfo, relnum, rela.get_r_offset(), + view[0] == 0xff && view[1] == 0x10); + view[0] = 0x66; + view[1] = 0x90; + } +} + +// Do a TLSDESC-style General-Dynamic to Local-Exec transition. + +template inline void -Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo, - size_t relnum, - Output_segment*, - const elfcpp::Rela<64, false>& rela, - unsigned int, - elfcpp::Elf_types<64>::Elf_Addr, - unsigned char* view, - off_t view_size) +Target_x86_64::Relocate::tls_desc_gd_to_le( + const Relocate_info* relinfo, + size_t relnum, + Output_segment* tls_segment, + const elfcpp::Rela& rela, + unsigned int r_type, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned char* view, + section_size_type view_size) +{ + if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC) + { + // leaq foo@tlsdesc(%rip), %rax + // ==> movq foo@tpoff, %rax + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3); + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4); + tls::check_tls(relinfo, relnum, rela.get_r_offset(), + view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05); + view[-2] = 0xc7; + view[-1] = 0xc0; + value -= tls_segment->memsz(); + Relocate_functions::rela32(view, value, 0); + } + else + { + // call *foo@tlscall(%rax) + // ==> nop; nop + gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL); + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2); + tls::check_tls(relinfo, relnum, rela.get_r_offset(), + view[0] == 0xff && view[1] == 0x10); + view[0] = 0x66; + view[1] = 0x90; + } +} + +template +inline void +Target_x86_64::Relocate::tls_ld_to_le( + const Relocate_info* relinfo, + size_t relnum, + Output_segment*, + const elfcpp::Rela& rela, + unsigned int, + typename elfcpp::Elf_types::Elf_Addr, + unsigned char* view, + section_size_type view_size) { // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt; + // For SIZE == 64: // ... leq foo@dtpoff(%rax),%reg // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx + // For SIZE == 32: + // ... leq foo@dtpoff(%rax),%reg + // ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3); tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9); tls::check_tls(relinfo, relnum, rela.get_r_offset(), - view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d); + view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d); tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8); - memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12); + if (size == 64) + memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12); + else + memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12); // The next reloc should be a PLT32 reloc against __tls_get_addr. // We can skip it. @@ -1836,15 +4186,17 @@ Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo, // Do a relocation in which we convert a TLS Initial-Exec to a // Local-Exec. +template inline void -Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo, - size_t relnum, - Output_segment* tls_segment, - const elfcpp::Rela<64, false>& rela, - unsigned int, - elfcpp::Elf_types<64>::Elf_Addr value, - unsigned char* view, - off_t view_size) +Target_x86_64::Relocate::tls_ie_to_le( + const Relocate_info* relinfo, + size_t relnum, + Output_segment* tls_segment, + const elfcpp::Rela& rela, + unsigned int, + typename elfcpp::Elf_types::Elf_Addr value, + unsigned char* view, + section_size_type view_size) { // We need to examine the opcodes to figure out which instruction we // are looking at. @@ -1864,7 +4216,9 @@ Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo, { // movq if (op1 == 0x4c) - view[-3] = 0x49; + view[-3] = 0x49; + else if (size == 32 && op1 == 0x44) + view[-3] = 0x41; view[-2] = 0xc7; view[-1] = 0xc0 | reg; } @@ -1872,7 +4226,9 @@ Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo, { // Special handling for %rsp. if (op1 == 0x4c) - view[-3] = 0x49; + view[-3] = 0x49; + else if (size == 32 && op1 == 0x44) + view[-3] = 0x41; view[-2] = 0x81; view[-1] = 0xc0 | reg; } @@ -1880,32 +4236,39 @@ Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo, { // addq if (op1 == 0x4c) - view[-3] = 0x4d; + view[-3] = 0x4d; + else if (size == 32 && op1 == 0x44) + view[-3] = 0x45; view[-2] = 0x8d; view[-1] = 0x80 | reg | (reg << 3); } - value = value - (tls_segment->vaddr() + tls_segment->memsz()); - Relocate_functions<64, false>::rela32(view, value, 0); + if (tls_segment != NULL) + value -= tls_segment->memsz(); + Relocate_functions::rela32(view, value, 0); } // Relocate section data. +template void -Target_x86_64::relocate_section(const Relocate_info<64, false>* 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, - elfcpp::Elf_types<64>::Elf_Addr address, - off_t view_size) +Target_x86_64::relocate_section( + const Relocate_info* 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, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size, + const Reloc_symbol_changes* reloc_symbol_changes) { gold_assert(sh_type == elfcpp::SHT_RELA); - gold::relocate_section<64, false, Target_x86_64, elfcpp::SHT_RELA, - Target_x86_64::Relocate>( + gold::relocate_section, elfcpp::SHT_RELA, + typename Target_x86_64::Relocate, + gold::Default_comdat_behavior>( relinfo, this, prelocs, @@ -1914,74 +4277,261 @@ Target_x86_64::relocate_section(const Relocate_info<64, false>* relinfo, needs_special_offset_handling, view, address, + view_size, + reloc_symbol_changes); +} + +// Apply an incremental relocation. Incremental relocations always refer +// to global symbols. + +template +void +Target_x86_64::apply_relocation( + const Relocate_info* relinfo, + typename elfcpp::Elf_types::Elf_Addr r_offset, + unsigned int r_type, + typename elfcpp::Elf_types::Elf_Swxword r_addend, + const Symbol* gsym, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr address, + section_size_type view_size) +{ + gold::apply_relocation, + typename Target_x86_64::Relocate>( + relinfo, + this, + r_offset, + r_type, + r_addend, + gsym, + view, + address, view_size); } +// Return the size of a relocation while scanning during a relocatable +// link. + +template +unsigned int +Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc( + unsigned int r_type, + Relobj* object) +{ + switch (r_type) + { + case elfcpp::R_X86_64_NONE: + case elfcpp::R_X86_64_GNU_VTINHERIT: + case elfcpp::R_X86_64_GNU_VTENTRY: + case elfcpp::R_X86_64_TLSGD: // Global-dynamic + case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url) + case elfcpp::R_X86_64_TLSDESC_CALL: + case elfcpp::R_X86_64_TLSLD: // Local-dynamic + case elfcpp::R_X86_64_DTPOFF32: + case elfcpp::R_X86_64_DTPOFF64: + case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec + case elfcpp::R_X86_64_TPOFF32: // Local-exec + return 0; + + case elfcpp::R_X86_64_64: + case elfcpp::R_X86_64_PC64: + case elfcpp::R_X86_64_GOTOFF64: + case elfcpp::R_X86_64_GOTPC64: + case elfcpp::R_X86_64_PLTOFF64: + case elfcpp::R_X86_64_GOT64: + case elfcpp::R_X86_64_GOTPCREL64: + case elfcpp::R_X86_64_GOTPCREL: + case elfcpp::R_X86_64_GOTPCRELX: + case elfcpp::R_X86_64_REX_GOTPCRELX: + case elfcpp::R_X86_64_GOTPLT64: + return 8; + + case elfcpp::R_X86_64_32: + case elfcpp::R_X86_64_32S: + case elfcpp::R_X86_64_PC32: + case elfcpp::R_X86_64_PC32_BND: + case elfcpp::R_X86_64_PLT32: + case elfcpp::R_X86_64_PLT32_BND: + case elfcpp::R_X86_64_GOTPC32: + case elfcpp::R_X86_64_GOT32: + return 4; + + case elfcpp::R_X86_64_16: + case elfcpp::R_X86_64_PC16: + return 2; + + case elfcpp::R_X86_64_8: + case elfcpp::R_X86_64_PC8: + return 1; + + case elfcpp::R_X86_64_COPY: + case elfcpp::R_X86_64_GLOB_DAT: + case elfcpp::R_X86_64_JUMP_SLOT: + case elfcpp::R_X86_64_RELATIVE: + case elfcpp::R_X86_64_IRELATIVE: + // These are outstanding tls relocs, which are unexpected when linking + case elfcpp::R_X86_64_TPOFF64: + case elfcpp::R_X86_64_DTPMOD64: + case elfcpp::R_X86_64_TLSDESC: + object->error(_("unexpected reloc %u in object file"), r_type); + return 0; + + case elfcpp::R_X86_64_SIZE32: + case elfcpp::R_X86_64_SIZE64: + default: + object->error(_("unsupported reloc %u against local symbol"), r_type); + return 0; + } +} + +// Scan the relocs during a relocatable link. + +template +void +Target_x86_64::scan_relocatable_relocs( + Symbol_table* symtab, + Layout* layout, + Sized_relobj_file* 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_RELA); + + typedef gold::Default_scan_relocatable_relocs Scan_relocatable_relocs; + + gold::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 +void +Target_x86_64::relocate_relocs( + const Relocate_info* relinfo, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + typename elfcpp::Elf_types::Elf_Off offset_in_output_section, + const Relocatable_relocs* rr, + unsigned char* view, + typename elfcpp::Elf_types::Elf_Addr view_address, + section_size_type view_size, + unsigned char* reloc_view, + section_size_type reloc_view_size) +{ + gold_assert(sh_type == elfcpp::SHT_RELA); + + gold::relocate_relocs( + 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 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 uint64_t -Target_x86_64::do_dynsym_value(const Symbol* gsym) const +Target_x86_64::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(); + return this->plt_address_for_global(gsym); } // Return a string used to fill a code section with nops to take up // the specified length. +template std::string -Target_x86_64::do_code_fill(off_t length) +Target_x86_64::do_code_fill(section_size_type length) const { if (length >= 16) { // Build a jmpq instruction to skip over the bytes. unsigned char jmp[5]; jmp[0] = 0xe9; - elfcpp::Swap_unaligned<64, false>::writeval(jmp + 1, length - 5); + elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5); return (std::string(reinterpret_cast(&jmp[0]), 5) - + std::string(length - 5, '\0')); + + std::string(length - 5, static_cast(0x90))); } // Nop sequences of various lengths. - const char nop1[1] = { 0x90 }; // nop - const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax - const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi - const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi - const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop - 0x00 }; // leal 0(%esi,1),%esi - const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi - 0x00, 0x00 }; - const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi - 0x00, 0x00, 0x00 }; - const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop - 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi - const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi - 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi - 0x00 }; - const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi - 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi - 0x00, 0x00 }; - const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi - 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi - 0x00, 0x00, 0x00 }; - const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi - 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi - 0x00, 0x00, 0x00, 0x00 }; - const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi - 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi - 0x27, 0x00, 0x00, 0x00, - 0x00 }; - const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi - 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi - 0xbc, 0x27, 0x00, 0x00, - 0x00, 0x00 }; - const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15 - 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,... - 0x90, 0x90, 0x90, 0x90, - 0x90, 0x90, 0x90 }; + const char nop1[1] = { '\x90' }; // nop + const char nop2[2] = { '\x66', '\x90' }; // xchg %ax %ax + const char nop3[3] = { '\x0f', '\x1f', '\x00' }; // nop (%rax) + const char nop4[4] = { '\x0f', '\x1f', '\x40', // nop 0(%rax) + '\x00'}; + const char nop5[5] = { '\x0f', '\x1f', '\x44', // nop 0(%rax,%rax,1) + '\x00', '\x00' }; + const char nop6[6] = { '\x66', '\x0f', '\x1f', // nopw 0(%rax,%rax,1) + '\x44', '\x00', '\x00' }; + const char nop7[7] = { '\x0f', '\x1f', '\x80', // nopl 0L(%rax) + '\x00', '\x00', '\x00', + '\x00' }; + const char nop8[8] = { '\x0f', '\x1f', '\x84', // nopl 0L(%rax,%rax,1) + '\x00', '\x00', '\x00', + '\x00', '\x00' }; + const char nop9[9] = { '\x66', '\x0f', '\x1f', // nopw 0L(%rax,%rax,1) + '\x84', '\x00', '\x00', + '\x00', '\x00', '\x00' }; + const char nop10[10] = { '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1) + '\x1f', '\x84', '\x00', + '\x00', '\x00', '\x00', + '\x00' }; + const char nop11[11] = { '\x66', '\x66', '\x2e', // data16 + '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1) + '\x00', '\x00', '\x00', + '\x00', '\x00' }; + const char nop12[12] = { '\x66', '\x66', '\x66', // data16; data16 + '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1) + '\x84', '\x00', '\x00', + '\x00', '\x00', '\x00' }; + const char nop13[13] = { '\x66', '\x66', '\x66', // data16; data16; data16 + '\x66', '\x2e', '\x0f', // nopw %cs:0L(%rax,%rax,1) + '\x1f', '\x84', '\x00', + '\x00', '\x00', '\x00', + '\x00' }; + const char nop14[14] = { '\x66', '\x66', '\x66', // data16; data16; data16 + '\x66', '\x66', '\x2e', // data16 + '\x0f', '\x1f', '\x84', // nopw %cs:0L(%rax,%rax,1) + '\x00', '\x00', '\x00', + '\x00', '\x00' }; + const char nop15[15] = { '\x66', '\x66', '\x66', // data16; data16; data16 + '\x66', '\x66', '\x66', // data16; data16 + '\x2e', '\x0f', '\x1f', // nopw %cs:0L(%rax,%rax,1) + '\x84', '\x00', '\x00', + '\x00', '\x00', '\x00' }; const char* nops[16] = { NULL, @@ -1992,33 +4542,520 @@ Target_x86_64::do_code_fill(off_t length) return std::string(nops[length], length); } -// The selector for x86_64 object files. +// Return the addend to use for a target specific relocation. The +// only target specific relocation is R_X86_64_TLSDESC for a local +// symbol. We want to set the addend is the offset of the local +// symbol in the TLS segment. -class Target_selector_x86_64 : public Target_selector +template +uint64_t +Target_x86_64::do_reloc_addend(void* arg, unsigned int r_type, + uint64_t) const +{ + gold_assert(r_type == elfcpp::R_X86_64_TLSDESC); + uintptr_t intarg = reinterpret_cast(arg); + gold_assert(intarg < this->tlsdesc_reloc_info_.size()); + const Tlsdesc_info& ti(this->tlsdesc_reloc_info_[intarg]); + const Symbol_value* psymval = ti.object->local_symbol(ti.r_sym); + gold_assert(psymval->is_tls_symbol()); + // The value of a TLS symbol is the offset in the TLS segment. + return psymval->value(ti.object, 0); +} + +// Return the value to use for the base of a DW_EH_PE_datarel offset +// in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their +// assembler can not write out the difference between two labels in +// different sections, so instead of using a pc-relative value they +// use an offset from the GOT. + +template +uint64_t +Target_x86_64::do_ehframe_datarel_base() const +{ + gold_assert(this->global_offset_table_ != NULL); + Symbol* sym = this->global_offset_table_; + Sized_symbol* ssym = static_cast*>(sym); + return ssym->value(); +} + +// FNOFFSET in section SHNDX in OBJECT is the start of a function +// compiled with -fsplit-stack. The function calls non-split-stack +// code. We have to change the function so that it always ensures +// that it has enough stack space to run some random function. + +static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 }; +static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 }; +static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 }; + +static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 }; +static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 }; +static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 }; + +template +void +Target_x86_64::do_calls_non_split(Relobj* object, unsigned int shndx, + section_offset_type fnoffset, + section_size_type fnsize, + unsigned char* view, + section_size_type view_size, + std::string* from, + std::string* to) const +{ + const char* const cmp_insn = reinterpret_cast + (size == 32 ? cmp_insn_32 : cmp_insn_64); + const char* const lea_r10_insn = reinterpret_cast + (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64); + const char* const lea_r11_insn = reinterpret_cast + (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64); + + const size_t cmp_insn_len = + (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64)); + const size_t lea_r10_insn_len = + (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64)); + const size_t lea_r11_insn_len = + (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64)); + const size_t nop_len = (size == 32 ? 7 : 8); + + // The function starts with a comparison of the stack pointer and a + // field in the TCB. This is followed by a jump. + + // cmp %fs:NN,%rsp + if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len) + && fnsize > nop_len + 1) + { + // We will call __morestack if the carry flag is set after this + // comparison. We turn the comparison into an stc instruction + // and some nops. + view[fnoffset] = '\xf9'; + this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len); + } + // lea NN(%rsp),%r10 + // lea NN(%rsp),%r11 + else if ((this->match_view(view, view_size, fnoffset, + lea_r10_insn, lea_r10_insn_len) + || this->match_view(view, view_size, fnoffset, + lea_r11_insn, lea_r11_insn_len)) + && fnsize > 8) + { + // This is loading an offset from the stack pointer for a + // comparison. The offset is negative, so we decrease the + // offset by the amount of space we need for the stack. This + // means we will avoid calling __morestack if there happens to + // be plenty of space on the stack already. + unsigned char* pval = view + fnoffset + 4; + uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval); + val -= parameters->options().split_stack_adjust_size(); + elfcpp::Swap_unaligned<32, false>::writeval(pval, val); + } + else + { + if (!object->has_no_split_stack()) + object->error(_("failed to match split-stack sequence at " + "section %u offset %0zx"), + shndx, static_cast(fnoffset)); + return; + } + + // We have to change the function so that it calls + // __morestack_non_split instead of __morestack. The former will + // allocate additional stack space. + *from = "__morestack"; + *to = "__morestack_non_split"; +} + +// The selector for x86_64 object files. Note this is never instantiated +// directly. It's only used in Target_selector_x86_64_nacl, below. + +template +class Target_selector_x86_64 : public Target_selector_freebsd { public: Target_selector_x86_64() - : Target_selector(elfcpp::EM_X86_64, 64, false) + : Target_selector_freebsd(elfcpp::EM_X86_64, size, false, + (size == 64 + ? "elf64-x86-64" : "elf32-x86-64"), + (size == 64 + ? "elf64-x86-64-freebsd" + : "elf32-x86-64-freebsd"), + (size == 64 ? "elf_x86_64" : "elf32_x86_64")) { } Target* - recognize(int machine, int osabi, int abiversion); + do_instantiate_target() + { return new Target_x86_64(); } + +}; + +// NaCl variant. It uses different PLT contents. + +template +class Output_data_plt_x86_64_nacl : public Output_data_plt_x86_64 +{ + public: + Output_data_plt_x86_64_nacl(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative) + : Output_data_plt_x86_64(layout, plt_entry_size, + got, got_plt, got_irelative) + { } + + Output_data_plt_x86_64_nacl(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative, + unsigned int plt_count) + : Output_data_plt_x86_64(layout, plt_entry_size, + got, got_plt, got_irelative, + plt_count) + { } + + protected: + virtual unsigned int + do_get_plt_entry_size() const + { return plt_entry_size; } + + virtual void + do_add_eh_frame(Layout* layout) + { + layout->add_eh_frame_for_plt(this, + this->plt_eh_frame_cie, + this->plt_eh_frame_cie_size, + plt_eh_frame_fde, + plt_eh_frame_fde_size); + } + + virtual void + do_fill_first_plt_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_addr, + typename elfcpp::Elf_types::Elf_Addr plt_addr); + + virtual unsigned int + do_fill_plt_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + unsigned int got_offset, + unsigned int plt_offset, + unsigned int plt_index); + + virtual void + do_fill_tlsdesc_entry(unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + typename elfcpp::Elf_types::Elf_Addr got_base, + unsigned int tlsdesc_got_offset, + unsigned int plt_offset); private: - Target_x86_64* target_; + // The size of an entry in the PLT. + static const int plt_entry_size = 64; + + // The first entry in the PLT. + static const unsigned char first_plt_entry[plt_entry_size]; + + // Other entries in the PLT for an executable. + static const unsigned char plt_entry[plt_entry_size]; + + // The reserved TLSDESC entry in the PLT for an executable. + static const unsigned char tlsdesc_plt_entry[plt_entry_size]; + + // The .eh_frame unwind information for the PLT. + static const int plt_eh_frame_fde_size = 32; + static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size]; }; -// Recognize an x86_64 object file when we already know that the machine -// number is EM_X86_64. +template +class Target_x86_64_nacl : public Target_x86_64 +{ + public: + Target_x86_64_nacl() + : Target_x86_64(&x86_64_nacl_info) + { } + + virtual Output_data_plt_x86_64* + do_make_data_plt(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative) + { + return new Output_data_plt_x86_64_nacl(layout, got, got_plt, + got_irelative); + } + + virtual Output_data_plt_x86_64* + do_make_data_plt(Layout* layout, + Output_data_got<64, false>* got, + Output_data_got_plt_x86_64* got_plt, + Output_data_space* got_irelative, + unsigned int plt_count) + { + return new Output_data_plt_x86_64_nacl(layout, got, got_plt, + got_irelative, + plt_count); + } + + virtual std::string + do_code_fill(section_size_type length) const; + + private: + static const Target::Target_info x86_64_nacl_info; +}; -Target* -Target_selector_x86_64::recognize(int, int, int) +template<> +const Target::Target_info Target_x86_64_nacl<64>::x86_64_nacl_info = { - if (this->target_ == NULL) - this->target_ = new Target_x86_64(); - return this->target_; + 64, // size + false, // is_big_endian + elfcpp::EM_X86_64, // machine_code + false, // has_make_symbol + false, // has_resolve + true, // has_code_fill + true, // is_default_stack_executable + true, // can_icf_inline_merge_sections + '\0', // wrap_char + "/lib64/ld-nacl-x86-64.so.1", // dynamic_linker + 0x20000, // default_text_segment_address + 0x10000, // abi_pagesize (overridable by -z max-page-size) + 0x10000, // common_pagesize (overridable by -z common-page-size) + true, // isolate_execinstr + 0x10000000, // rosegment_gap + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx + 0, // small_common_section_flags + elfcpp::SHF_X86_64_LARGE, // large_common_section_flags + NULL, // attributes_section + NULL, // attributes_vendor + "_start", // entry_symbol_name + 32, // hash_entry_size +}; + +template<> +const Target::Target_info Target_x86_64_nacl<32>::x86_64_nacl_info = +{ + 32, // size + false, // is_big_endian + elfcpp::EM_X86_64, // machine_code + false, // has_make_symbol + false, // has_resolve + true, // has_code_fill + true, // is_default_stack_executable + true, // can_icf_inline_merge_sections + '\0', // wrap_char + "/lib/ld-nacl-x86-64.so.1", // dynamic_linker + 0x20000, // default_text_segment_address + 0x10000, // abi_pagesize (overridable by -z max-page-size) + 0x10000, // common_pagesize (overridable by -z common-page-size) + true, // isolate_execinstr + 0x10000000, // rosegment_gap + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx + 0, // small_common_section_flags + elfcpp::SHF_X86_64_LARGE, // large_common_section_flags + NULL, // attributes_section + NULL, // attributes_vendor + "_start", // entry_symbol_name + 32, // hash_entry_size +}; + +#define NACLMASK 0xe0 // 32-byte alignment mask. + +// The first entry in the PLT. + +template +const unsigned char +Output_data_plt_x86_64_nacl::first_plt_entry[plt_entry_size] = +{ + 0xff, 0x35, // pushq contents of memory address + 0, 0, 0, 0, // replaced with address of .got + 8 + 0x4c, 0x8b, 0x1d, // mov GOT+16(%rip), %r11 + 0, 0, 0, 0, // replaced with address of .got + 16 + 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d + 0x4d, 0x01, 0xfb, // add %r15, %r11 + 0x41, 0xff, 0xe3, // jmpq *%r11 + + // 9-byte nop sequence to pad out to the next 32-byte boundary. + 0x66, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw 0x0(%rax,%rax,1) + + // 32 bytes of nop to pad out to the standard size + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes + 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1) + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes + 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1) + 0x66, // excess data32 prefix + 0x90 // nop +}; + +template +void +Output_data_plt_x86_64_nacl::do_fill_first_plt_entry( + unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address) +{ + memcpy(pov, first_plt_entry, plt_entry_size); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, + (got_address + 8 + - (plt_address + 2 + 4))); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 9, + (got_address + 16 + - (plt_address + 9 + 4))); +} + +// Subsequent entries in the PLT. + +template +const unsigned char +Output_data_plt_x86_64_nacl::plt_entry[plt_entry_size] = +{ + 0x4c, 0x8b, 0x1d, // mov name@GOTPCREL(%rip),%r11 + 0, 0, 0, 0, // replaced with address of symbol in .got + 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d + 0x4d, 0x01, 0xfb, // add %r15, %r11 + 0x41, 0xff, 0xe3, // jmpq *%r11 + + // 15-byte nop sequence to pad out to the next 32-byte boundary. + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes + 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1) + + // Lazy GOT entries point here (32-byte aligned). + 0x68, // pushq immediate + 0, 0, 0, 0, // replaced with index into relocation table + 0xe9, // jmp relative + 0, 0, 0, 0, // replaced with offset to start of .plt0 + + // 22 bytes of nop to pad out to the standard size. + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes + 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1) + 0x0f, 0x1f, 0x80, 0, 0, 0, 0, // nopl 0x0(%rax) +}; + +template +unsigned int +Output_data_plt_x86_64_nacl::do_fill_plt_entry( + unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + unsigned int got_offset, + unsigned int plt_offset, + unsigned int plt_index) +{ + memcpy(pov, plt_entry, plt_entry_size); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 3, + (got_address + got_offset + - (plt_address + plt_offset + + 3 + 4))); + + elfcpp::Swap_unaligned<32, false>::writeval(pov + 33, plt_index); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 38, + - (plt_offset + 38 + 4)); + + return 32; +} + +// The reserved TLSDESC entry in the PLT. + +template +const unsigned char +Output_data_plt_x86_64_nacl::tlsdesc_plt_entry[plt_entry_size] = +{ + 0xff, 0x35, // pushq x(%rip) + 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8) + 0x4c, 0x8b, 0x1d, // mov y(%rip),%r11 + 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry + 0x41, 0x83, 0xe3, NACLMASK, // and $-32, %r11d + 0x4d, 0x01, 0xfb, // add %r15, %r11 + 0x41, 0xff, 0xe3, // jmpq *%r11 + + // 41 bytes of nop to pad out to the standard size. + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes + 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1) + 0x66, 0x66, 0x66, 0x66, 0x66, 0x66, // excess data32 prefixes + 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1) + 0x66, 0x66, // excess data32 prefixes + 0x2e, 0x0f, 0x1f, 0x84, 0, 0, 0, 0, 0, // nopw %cs:0x0(%rax,%rax,1) +}; + +template +void +Output_data_plt_x86_64_nacl::do_fill_tlsdesc_entry( + unsigned char* pov, + typename elfcpp::Elf_types::Elf_Addr got_address, + typename elfcpp::Elf_types::Elf_Addr plt_address, + typename elfcpp::Elf_types::Elf_Addr got_base, + unsigned int tlsdesc_got_offset, + unsigned int plt_offset) +{ + memcpy(pov, tlsdesc_plt_entry, plt_entry_size); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, + (got_address + 8 + - (plt_address + plt_offset + + 2 + 4))); + elfcpp::Swap_unaligned<32, false>::writeval(pov + 9, + (got_base + + tlsdesc_got_offset + - (plt_address + plt_offset + + 9 + 4))); } -Target_selector_x86_64 target_selector_x86_64; +// The .eh_frame unwind information for the PLT. + +template +const unsigned char +Output_data_plt_x86_64_nacl::plt_eh_frame_fde[plt_eh_frame_fde_size] = +{ + 0, 0, 0, 0, // Replaced with offset to .plt. + 0, 0, 0, 0, // Replaced with size of .plt. + 0, // Augmentation size. + elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16. + elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6. + elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24. + elfcpp::DW_CFA_advance_loc + 58, // Advance 58 to __PLT__ + 64. + elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression. + 13, // Block length. + elfcpp::DW_OP_breg7, 8, // Push %rsp + 8. + elfcpp::DW_OP_breg16, 0, // Push %rip. + elfcpp::DW_OP_const1u, 63, // Push 0x3f. + elfcpp::DW_OP_and, // & (%rip & 0x3f). + elfcpp::DW_OP_const1u, 37, // Push 0x25. + elfcpp::DW_OP_ge, // >= ((%rip & 0x3f) >= 0x25) + elfcpp::DW_OP_lit3, // Push 3. + elfcpp::DW_OP_shl, // << (((%rip & 0x3f) >= 0x25) << 3) + elfcpp::DW_OP_plus, // + ((((%rip&0x3f)>=0x25)<<3)+%rsp+8 + elfcpp::DW_CFA_nop, // Align to 32 bytes. + elfcpp::DW_CFA_nop +}; + +// Return a string used to fill a code section with nops. +// For NaCl, long NOPs are only valid if they do not cross +// bundle alignment boundaries, so keep it simple with one-byte NOPs. +template +std::string +Target_x86_64_nacl::do_code_fill(section_size_type length) const +{ + return std::string(length, static_cast(0x90)); +} + +// The selector for x86_64-nacl object files. + +template +class Target_selector_x86_64_nacl + : public Target_selector_nacl, + Target_x86_64_nacl > +{ + public: + Target_selector_x86_64_nacl() + : Target_selector_nacl, + Target_x86_64_nacl >("x86-64", + size == 64 + ? "elf64-x86-64-nacl" + : "elf32-x86-64-nacl", + size == 64 + ? "elf_x86_64_nacl" + : "elf32_x86_64_nacl") + { } +}; + +Target_selector_x86_64_nacl<64> target_selector_x86_64; +Target_selector_x86_64_nacl<32> target_selector_x32; } // End anonymous namespace.