X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Fx86_64.cc;h=c325fc00daa5f0232108e40c51edad1574580288;hb=f5c870d25d59bc1e6fcb6a836b6bd1981788982c;hp=75c2b7f1bd4dfb145af0308d1b8de872d60a7931;hpb=1b64748beda63e896f48cb4c9409d8629db10747;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/x86_64.cc b/gold/x86_64.cc index 75c2b7f1bd..c325fc00da 100644 --- a/gold/x86_64.cc +++ b/gold/x86_64.cc @@ -1,33 +1,24 @@ // x86_64.cc -- x86_64 target support for gold. -// Copyright 2006, 2007, Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009 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" @@ -41,10 +32,13 @@ #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 "gc.h" namespace { @@ -60,7 +54,7 @@ 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> +class Target_x86_64 : public Target_freebsd<64, false> { public: // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures @@ -68,28 +62,47 @@ class Target_x86_64 : public Sized_target<64, false> typedef Output_data_reloc Reloc_section; Target_x86_64() - : Sized_target<64, false>(&x86_64_info), + : Target_freebsd<64, false>(&x86_64_info), got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL), - copy_relocs_(NULL), dynbss_(NULL) + copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL), + got_mod_index_offset_(-1U), 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 + gc_process_relocs(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); + // Scan the relocations to look for symbol adjustments. void - scan_relocs(const General_options& options, - Symbol_table* symtab, + scan_relocs(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, - Symbol** global_symbols); + const unsigned char* plocal_symbols); // Finalize the sections. void - do_finalize_sections(Layout*); + do_finalize_sections(Layout*, const Input_objects*); // Return the value to use for a dynamic which requires special // treatment. @@ -102,40 +115,105 @@ class Target_x86_64 : public Sized_target<64, false> 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); + 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<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, + Relocatable_relocs*); + + // Relocate a section during a relocatable link. + void + relocate_for_relocatable(const Relocate_info<64, false>*, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + off_t offset_in_output_section, + const Relocatable_relocs*, + unsigned char* view, + elfcpp::Elf_types<64>::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(const Symbol* sym) const + { return strcmp(sym->name(), "__tls_get_addr") == 0; } + + // Adjust -fstack-split code which calls non-stack-split 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. + section_size_type + got_size() + { + gold_assert(this->got_ != NULL); + return this->got_->data_size(); + } private: // The class which scans relocations. - struct Scan + class Scan { + public: + Scan() + : issued_non_pic_error_(false) + { } + inline void - local(const General_options& options, Symbol_table* symtab, - Layout* layout, Target_x86_64* target, + local(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); inline void - global(const General_options& options, Symbol_table* symtab, - Layout* layout, Target_x86_64* target, + global(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); + private: static void unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type); static void unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type, Symbol*); + + void + check_non_pic(Relobj*, 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. @@ -143,7 +221,7 @@ class Target_x86_64 : public Sized_target<64, false> { public: Relocate() - : skip_call_tls_get_addr_(false) + : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false) { } ~Relocate() @@ -158,30 +236,32 @@ 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>&, + relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*, + 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); + section_size_type); private: // Do a TLS relocation. inline void - relocate_tls(const Relocate_info<64, false>*, size_t relnum, - const elfcpp::Rela<64, false>&, + 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); + unsigned char*, elfcpp::Elf_types<64>::Elf_Addr, + section_size_type); - // Do a TLS Initial-Exec to Local-Exec transition. - static inline void - tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum, + // Do a TLS General-Dynamic to Initial-Exec transition. + inline void + tls_gd_to_ie(const Relocate_info<64, false>*, size_t relnum, Output_segment* tls_segment, const elfcpp::Rela<64, false>&, unsigned int r_type, elfcpp::Elf_types<64>::Elf_Addr value, unsigned char* view, - off_t view_size); + elfcpp::Elf_types<64>::Elf_Addr, + section_size_type view_size); // Do a TLS General-Dynamic to Local-Exec transition. inline void @@ -190,7 +270,26 @@ class Target_x86_64 : public Sized_target<64, false> const elfcpp::Rela<64, false>&, unsigned int r_type, elfcpp::Elf_types<64>::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<64, false>*, size_t relnum, + Output_segment* tls_segment, + const elfcpp::Rela<64, false>&, unsigned int r_type, + elfcpp::Elf_types<64>::Elf_Addr value, + unsigned char* view, + elfcpp::Elf_types<64>::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<64, false>*, size_t relnum, + Output_segment* tls_segment, + const elfcpp::Rela<64, false>&, unsigned int r_type, + elfcpp::Elf_types<64>::Elf_Addr value, + unsigned char* view, + section_size_type view_size); // Do a TLS Local-Dynamic to Local-Exec transition. inline void @@ -199,11 +298,35 @@ class Target_x86_64 : public Sized_target<64, false> const elfcpp::Rela<64, false>&, unsigned int r_type, elfcpp::Elf_types<64>::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, + Output_segment* tls_segment, + const elfcpp::Rela<64, false>&, unsigned int r_type, + elfcpp::Elf_types<64>::Elf_Addr value, + unsigned char* view, + 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_; + + // This is set if we see a relocation which could load the address + // of the TLS block. Whether we see such a relocation determines + // how we handle the R_X86_64_DTPOFF32 relocation, which is used + // in debugging sections. + bool saw_tls_block_reloc_; + }; + + // 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*); }; // Adjust TLS relocation type based on the options and whether this @@ -215,10 +338,35 @@ class Target_x86_64 : public Sized_target<64, false> Output_data_got<64, false>* got_section(Symbol_table*, Layout*); + // Get the GOT PLT section. + Output_data_space* + got_plt_section() const + { + gold_assert(this->got_plt_ != NULL); + return this->got_plt_; + } + + // Create 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*); + // 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<64, false>* object); + // Get the PLT section. Output_data_plt_x86_64* plt_section() const @@ -231,16 +379,31 @@ class Target_x86_64 : public Sized_target<64, false> Reloc_section* rela_dyn_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, - Symbol*, const elfcpp::Rela<64, false>&); + copy_reloc(Symbol_table* symtab, Layout* layout, + Sized_relobj<64, false>* object, + unsigned int shndx, Output_section* output_section, + Symbol* sym, const elfcpp::Rela<64, false>& reloc) + { + this->copy_relocs_.copy_reloc(symtab, layout, + symtab->get_sized_symbol<64>(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; + 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 + }; + // The GOT section. Output_data_got<64, false>* got_; // The PLT section. @@ -250,9 +413,13 @@ class Target_x86_64 : public Sized_target<64, false> // The dynamic reloc section. Reloc_section* rela_dyn_; // Relocs saved to avoid a COPY reloc. - Copy_relocs<64, false>* copy_relocs_; + Copy_relocs copy_relocs_; // Space for variables copied with a COPY reloc. Output_data_space* dynbss_; + // Offset of the GOT entry for the TLS module index. + unsigned int got_mod_index_offset_; + // 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 = @@ -263,12 +430,28 @@ const Target::Target_info Target_x86_64::x86_64_info = false, // has_make_symbol false, // has_resolve true, // has_code_fill + true, // is_default_stack_executable + '\0', // wrap_char "/lib/ld64.so.1", // program interpreter - 0x400000, // text_segment_address - 0x1000, // abi_pagesize - 0x1000 // common_pagesize + 0x400000, // default_text_segment_address + 0x1000, // abi_pagesize (overridable by -z max-page-size) + 0x1000, // common_pagesize (overridable by -z common-page-size) + elfcpp::SHN_UNDEF, // small_common_shndx + elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx + 0, // small_common_section_flags + elfcpp::SHF_X86_64_LARGE // large_common_section_flags }; +// This is called when a new output section is created. This is where +// we handle the SHF_X86_64_LARGE. + +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. Output_data_got<64, false>* @@ -280,25 +463,29 @@ Target_x86_64::got_section(Symbol_table* symtab, Layout* layout) 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_); + Output_section* os; + os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_, false); + os->set_is_relro(); // The old GNU linker creates a .got.plt section. We just // create another set of data in the .got section. Note that we // always create a PLT if we create a GOT, although the PLT // might be empty. - // TODO(csilvers): do we really need an alignment of 8? - 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_); + this->got_plt_ = new Output_data_space(8, "** GOT PLT"); + os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS, + (elfcpp::SHF_ALLOC + | elfcpp::SHF_WRITE), + this->got_plt_, false); + os->set_is_relro(); // The first three entries are reserved. - this->got_plt_->set_space_size(3 * 8); + this->got_plt_->set_current_data_size(3 * 8); // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT. - symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL, + symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL, this->got_plt_, 0, 0, elfcpp::STT_OBJECT, elfcpp::STB_LOCAL, @@ -317,9 +504,9 @@ 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_, true); } return this->rela_dyn_; } @@ -331,12 +518,33 @@ class Output_data_plt_x86_64 : public Output_section_data public: typedef Output_data_reloc Reloc_section; - Output_data_plt_x86_64(Layout*, Output_data_space*); + Output_data_plt_x86_64(Layout*, Output_data_got<64, false>*, + Output_data_space*); // Add an entry to the PLT. void add_entry(Symbol* gsym); + // 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_ + 1) * plt_entry_size; } + // Return the .rel.plt section data. const Reloc_section* rel_plt() const @@ -346,6 +554,11 @@ class Output_data_plt_x86_64 : public Output_section_data void do_adjust_output_section(Output_section* os); + // Write to a map file. + void + do_print_to_mapfile(Mapfile* mapfile) const + { mapfile->print_output_data(this, _("** PLT")); } + private: // The size of an entry in the PLT. static const int plt_entry_size = 16; @@ -358,10 +571,12 @@ class Output_data_plt_x86_64 : public Output_section_data // Other entries in the PLT for an executable. static unsigned char plt_entry[plt_entry_size]; + // The reserved TLSDESC entry in the PLT for an executable. + static unsigned char tlsdesc_plt_entry[plt_entry_size]; + // Set the final size. void - do_set_address(uint64_t, off_t) - { this->set_data_size((this->count_ + 1) * plt_entry_size); } + set_final_data_size(); // Write out the PLT data. void @@ -369,10 +584,14 @@ class Output_data_plt_x86_64 : public Output_section_data // The reloc section. Reloc_section* rel_; + // The .got section. + Output_data_got<64, false>* got_; // The .got.plt section. Output_data_space* got_plt_; // The number of PLT entries. unsigned int count_; + // Offset of the reserved TLSDESC_GOT entry when needed. + unsigned int tlsdesc_got_offset_; }; // Create the PLT section. The ordinary .got section is an argument, @@ -380,21 +599,20 @@ class Output_data_plt_x86_64 : public Output_section_data // section just for PLT entries. Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout, + Output_data_got<64, false>* got, Output_data_space* got_plt) - // TODO(csilvers): do we really need an alignment of 8? - : Output_section_data(8), got_plt_(got_plt), count_(0) + : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0), + tlsdesc_got_offset_(-1U) { - 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_, true); } void 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(plt_entry_size); } // Add an entry to the PLT. @@ -410,12 +628,12 @@ Output_data_plt_x86_64::add_entry(Symbol* gsym) ++this->count_; - off_t got_offset = this->got_plt_->data_size(); + section_offset_type got_offset = this->got_plt_->current_data_size(); // Every PLT entry needs a GOT entry which points back to the PLT // entry (this will be changed by the dynamic linker, normally // lazily when the function is called). - this->got_plt_->set_space_size(got_offset + 8); + this->got_plt_->set_current_data_size(got_offset + 8); // Every PLT entry needs a reloc. gsym->set_needs_dynsym_entry(); @@ -427,15 +645,25 @@ Output_data_plt_x86_64::add_entry(Symbol* gsym) // appear in the relocations. } +// Set the final size. +void +Output_data_plt_x86_64::set_final_data_size() +{ + unsigned int count = this->count_; + if (this->has_tlsdesc_entry()) + ++count; + this->set_data_size((count + 1) * 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] = { // From AMD64 ABI Draft 0.98, page 76 0xff, 0x35, // pushq contents of memory address - 0, 0, 0, 0, // replaced with address of .got + 4 - 0xff, 0x25, // jmp indirect 0, 0, 0, 0, // replaced with address of .got + 8 + 0xff, 0x25, // jmp indirect + 0, 0, 0, 0, // replaced with address of .got + 16 0x90, 0x90, 0x90, 0x90 // noop (x4) }; @@ -452,6 +680,20 @@ unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] = 0, 0, 0, 0 // replaced with offset to start of .plt }; +// The reserved TLSDESC entry in the PLT for an executable. + +unsigned char Output_data_plt_x86_64::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 +}; + // Write out the PLT. This uses the hand-coded instructions above, // and adjusts them as needed. This is specified by the AMD64 ABI. @@ -459,28 +701,35 @@ void 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(); + const section_size_type got_size = + convert_to_section_size_type(this->got_plt_->data_size()); unsigned char* const got_view = of->get_output_view(got_file_offset, got_size); unsigned char* pov = oview; - 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. + elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address(); + // The base address of the .got section. + elfcpp::Elf_types<64>::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. + elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address(); memcpy(pov, first_plt_entry, plt_entry_size); - if (!parameters->output_is_shared()) - { - // 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)); - } + // 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; unsigned char* got_pov = got_view; @@ -501,14 +750,10 @@ Output_data_plt_x86_64::do_write(Output_file* of) { // Set and adjust the PLT entry itself. memcpy(pov, plt_entry, plt_entry_size); - if (parameters->output_is_shared()) - // FIXME(csilvers): what's the right thing to write here? - elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset); - else - elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, - (got_address + got_offset - - (plt_address + plt_offset - + 6))); + 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, @@ -518,123 +763,129 @@ Output_data_plt_x86_64::do_write(Output_file* of) elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6); } - 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(); + 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))); + pov += 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. 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_ = new Output_data_plt_x86_64(layout, this->got_, + this->got_plt_); layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS, (elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR), - this->plt_); + this->plt_, false); } +} + +// Create a PLT entry for a global symbol. + +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(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. +// Define the _TLS_MODULE_BASE_ symbol in the TLS segment. void -Target_x86_64::copy_reloc(const General_options* options, - Symbol_table* symtab, - Layout* layout, - Sized_relobj<64, false>* object, - unsigned int data_shndx, Symbol* gsym, - const elfcpp::Rela<64, false>& rela) +Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, Layout* layout) { - Sized_symbol<64>* ssym; - ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(64) (gsym - SELECT_SIZE(64)); + if (this->tls_base_symbol_defined_) + return; - if (!Copy_relocs<64, false>::need_copy_reloc(options, object, - data_shndx, ssym)) + Output_segment* tls_segment = layout->tls_segment(); + if (tls_segment != NULL) { - // 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, rela); + bool is_exec = parameters->options().output_is_executable(); + symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL, + tls_segment, 0, 0, + elfcpp::STT_TLS, + elfcpp::STB_LOCAL, + elfcpp::STV_HIDDEN, 0, + (is_exec + ? Symbol::SEGMENT_END + : Symbol::SEGMENT_START), + true); } - else - { - // Allocate space for this symbol in the .bss section. - - elfcpp::Elf_types<64>::Elf_WXword symsize = ssym->symsize(); - - // There is no defined way to determine the required alignment - // of the symbol. We pick the alignment based on the size. We - // set an arbitrary maximum of 256. - unsigned int align; - for (align = 1; align < 512; align <<= 1) - if ((symsize & align) != 0) - break; + this->tls_base_symbol_defined_ = true; +} - if (this->dynbss_ == NULL) - { - this->dynbss_ = new Output_data_space(align); - layout->add_output_section_data(".bss", - elfcpp::SHT_NOBITS, - (elfcpp::SHF_ALLOC - | elfcpp::SHF_WRITE), - this->dynbss_); - } +// Create the reserved PLT and GOT entries for the TLS descriptor resolver. - Output_data_space* dynbss = this->dynbss_; +void +Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab, + Layout* layout) +{ + if (this->plt_ == NULL) + this->make_plt_section(symtab, layout); - if (align > dynbss->addralign()) - dynbss->set_space_alignment(align); + 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); - off_t dynbss_size = dynbss->data_size(); - dynbss_size = align_address(dynbss_size, align); - off_t offset = dynbss_size; - dynbss->set_space_size(dynbss_size + symsize); + // Allocate the TLSDESC_PLT entry. + this->plt_->reserve_tlsdesc_entry(got_offset); + } +} - // Define the symbol in the .dynbss section. - symtab->define_in_output_data(this, ssym->name(), ssym->version(), - dynbss, offset, symsize, ssym->type(), - ssym->binding(), ssym->visibility(), - ssym->nonvis(), false, false); +// Create a GOT entry for the TLS module index. - // Add the COPY reloc. - ssym->set_needs_dynsym_entry(); +unsigned int +Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout, + Sized_relobj<64, false>* 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); - rela_dyn->add_global(ssym, elfcpp::R_X86_64_COPY, dynbss, offset, 0); + 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. @@ -644,7 +895,7 @@ 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) @@ -700,18 +951,61 @@ Target_x86_64::Scan::unsupported_reloc_local(Sized_relobj<64, false>* object, 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. + +void +Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type) +{ + switch (r_type) + { + // These are the relocation types supported by glibc for x86_64. + case elfcpp::R_X86_64_RELATIVE: + 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_32: + case elfcpp::R_X86_64_PC32: + case elfcpp::R_X86_64_COPY: + 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; " + "recompile with -fPIC")); + this->issued_non_pic_error_ = true; + return; + + case elfcpp::R_X86_64_NONE: + gold_unreachable(); + } +} + // Scan a relocation for a local symbol. inline void -Target_x86_64::Scan::local(const General_options&, - Symbol_table* symtab, +Target_x86_64::Scan::local(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>&) + const elfcpp::Sym<64, false>& lsym) { switch (r_type) { @@ -721,13 +1015,59 @@ Target_x86_64::Scan::local(const General_options&, 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_X86_64_RELATIVE relocation so the dynamic loader can + // relocate it easily. + if (parameters->options().output_is_position_independent()) + { + unsigned int r_sym = elfcpp::elf_r_sym<64>(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()); + } + 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: - // FIXME: If we are generating a shared object we need to copy - // this relocation into the object. - gold_assert(!parameters->output_is_shared()); + // 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()) + { + this->check_non_pic(object, r_type); + + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + unsigned int r_sym = elfcpp::elf_r_sym<64>(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: @@ -736,33 +1076,55 @@ Target_x86_64::Scan::local(const General_options&, case elfcpp::R_X86_64_PC8: break; - case elfcpp::R_X86_64_GOTPC32: // TODO(csilvers): correct? + case elfcpp::R_X86_64_PLT32: + // Since we know this is a local symbol, we can handle this as a + // PC32 reloc. + break; + + case elfcpp::R_X86_64_GOTPC32: case elfcpp::R_X86_64_GOTOFF64: - case elfcpp::R_X86_64_GOTPC64: // TODO(csilvers): correct? - case elfcpp::R_X86_64_PLTOFF64: // TODO(csilvers): correct? + case elfcpp::R_X86_64_GOTPC64: + case elfcpp::R_X86_64_PLTOFF64: // We need a GOT section. target->got_section(symtab, layout); + // For PLTOFF64, we'd normally want a PLT section, but since we + // know this is a local symbol, no PLT is needed. break; 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_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 (got->add_local(object, r_sym, GOT_TYPE_STANDARD)) { // If we are generating a shared object, we need to add a - // dynamic RELATIVE relocation for this symbol. - if (parameters->output_is_shared()) + // dynamic relocation for this symbol's GOT entry. + if (parameters->options().output_is_position_independent()) { Reloc_section* rela_dyn = target->rela_dyn_section(layout); - rela_dyn->add_local(object, 0, elfcpp::R_X86_64_RELATIVE, - data_shndx, reloc.get_r_offset(), 0); + // R_X86_64_RELATIVE assumes a 64-bit relocation. + if (r_type != elfcpp::R_X86_64_GOT32) + rela_dyn->add_local_relative( + object, r_sym, elfcpp::R_X86_64_RELATIVE, got, + object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0); + else + { + this->check_non_pic(object, r_type); + + 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; @@ -779,50 +1141,110 @@ Target_x86_64::Scan::local(const General_options&, break; // These are initial tls relocs, which are expected when linking - case elfcpp::R_X86_64_TLSGD: - case elfcpp::R_X86_64_GOTPC32_TLSDESC: + 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: - case elfcpp::R_X86_64_GOTTPOFF: - case elfcpp::R_X86_64_TPOFF32: + 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 { - 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); switch (r_type) { - case elfcpp::R_X86_64_TPOFF32: // Local-exec - // FIXME: If generating a shared object, we need to copy - // this relocation into the object. - gold_assert(!output_is_shared); + 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()); + 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_rela(object, r_sym, + shndx, + GOT_TYPE_TLS_PAIR, + target->rela_dyn_section(layout), + elfcpp::R_X86_64_DTPMOD64, 0); + } + else if (optimized_type != tls::TLSOPT_TO_LE) + unsupported_reloc_local(object, r_type); + break; + + 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. + Output_data_got<64, false>* got + = target->got_section(symtab, layout); + unsigned int r_sym = elfcpp::elf_r_sym<64>(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_rela(object, r_sym, + shndx, + GOT_TYPE_TLS_DESC, + target->rela_dyn_section(layout), + elfcpp::R_X86_64_TLSDESC, 0); + } + else if (optimized_type != tls::TLSOPT_TO_LE) + unsupported_reloc_local(object, r_type); break; - case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec - // FIXME: If not relaxing to LE, we need to generate a - // TPOFF64 reloc. - if (optimized_type != tls::TLSOPT_TO_LE) - unsupported_reloc_local(object, r_type); - break; + 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. + 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: - // FIXME: If not relaxing to LE, we need to generate a - // DTPMOD64 reloc. - if (optimized_type != tls::TLSOPT_TO_LE) - unsupported_reloc_local(object, r_type); 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<64>(reloc.get_r_info()); + got->add_local_with_rela(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_TLSGD: // General-dynamic - 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 relocs. - if (optimized_type != tls::TLSOPT_TO_LE) - 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: @@ -831,10 +1253,8 @@ Target_x86_64::Scan::local(const General_options&, } break; - case elfcpp::R_X86_64_GOTPLT64: - case elfcpp::R_X86_64_PLT32: - case elfcpp::R_X86_64_SIZE32: // TODO(csilvers): correct? - case elfcpp::R_X86_64_SIZE64: // TODO(csilvers): correct? + case elfcpp::R_X86_64_SIZE32: + case elfcpp::R_X86_64_SIZE64: default: gold_error(_("%s: unsupported reloc %u against local symbol"), object->name().c_str(), r_type); @@ -851,18 +1271,18 @@ Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj<64, false>* object, Symbol* gsym) { gold_error(_("%s: unsupported reloc %u against global symbol %s"), - object->name().c_str(), r_type, gsym->name()); + object->name().c_str(), r_type, gsym->demangled_name().c_str()); } // Scan a relocation for a global symbol. inline void -Target_x86_64::Scan::global(const General_options& options, - Symbol_table* symtab, +Target_x86_64::Scan::global(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) @@ -875,44 +1295,80 @@ Target_x86_64::Scan::global(const General_options& options, break; case elfcpp::R_X86_64_64: - case elfcpp::R_X86_64_PC64: case elfcpp::R_X86_64_32: case elfcpp::R_X86_64_32S: - case elfcpp::R_X86_64_PC32: case elfcpp::R_X86_64_16: - case elfcpp::R_X86_64_PC16: case elfcpp::R_X86_64_8: - case elfcpp::R_X86_64_PC8: - // FIXME: If we are generating a shared object we may need to - // copy this relocation into the object. If this symbol is - // defined in a shared object, we may need to copy this - // relocation in order to avoid a COPY relocation. - gold_assert(!parameters->output_is_shared()); - - if (gsym->is_from_dynobj()) - { - // This symbol is defined in a dynamic object. If it is a - // function, we make a PLT entry. Otherwise we need to - // either generate a COPY reloc or copy this reloc. - if (gsym->type() == elfcpp::STT_FUNC) - { - target->make_plt_entry(symtab, layout, gsym); - - // If this is not a PC relative reference, then we may - // be taking the address of the function. In that case - // we need to set the entry in the dynamic symbol table - // to the address of the PLT entry. - if (r_type != elfcpp::R_X86_64_PC64 - && r_type != elfcpp::R_X86_64_PC32 - && r_type != elfcpp::R_X86_64_PC16 - && r_type != elfcpp::R_X86_64_PC8) - gsym->set_needs_dynsym_value(); - } - else - target->copy_reloc(&options, symtab, layout, object, data_shndx, - gsym, reloc); - } + { + // 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(Symbol::ABSOLUTE_REF)) + { + if (gsym->may_need_copy_reloc()) + { + target->copy_reloc(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_global_relative(gsym, elfcpp::R_X86_64_RELATIVE, + output_section, object, + data_shndx, reloc.get_r_offset(), + reloc.get_r_addend()); + } + else + { + this->check_non_pic(object, r_type); + 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_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. + int flags = Symbol::NON_PIC_REF; + if (gsym->type() == elfcpp::STT_FUNC) + flags |= Symbol::FUNCTION_CALL; + if (gsym->needs_dynamic_reloc(flags)) + { + if (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); + 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_GOT64: @@ -923,17 +1379,31 @@ Target_x86_64::Scan::global(const General_options& options, { // The symbol requires a GOT entry. Output_data_got<64, false>* got = target->got_section(symtab, layout); - if (got->add_global(gsym)) - { + if (gsym->final_value_is_known()) + got->add_global(gsym, GOT_TYPE_STANDARD); + else + { // If this symbol is not fully resolved, we need to add a // dynamic relocation for it. - if (!gsym->final_value_is_known()) + Reloc_section* rela_dyn = target->rela_dyn_section(layout); + if (gsym->is_from_dynobj() + || gsym->is_undefined() + || gsym->is_preemptible()) + got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn, + elfcpp::R_X86_64_GLOB_DAT); + else { - Reloc_section* rela_dyn = target->rela_dyn_section(layout); - rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT, got, - gsym->got_offset(), 0); + if (got->add_global(gsym, GOT_TYPE_STANDARD)) + rela_dyn->add_global_relative( + gsym, elfcpp::R_X86_64_RELATIVE, got, + gsym->got_offset(GOT_TYPE_STANDARD), 0); } } + // 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); } break; @@ -942,15 +1412,27 @@ Target_x86_64::Scan::global(const General_options& options, // Otherwise we need a PLT entry. if (gsym->final_value_is_known()) break; + // If building a shared library, we can also skip the PLT entry + // if the symbol is defined in the output file and is protected + // or hidden. + if (gsym->is_defined() + && !gsym->is_from_dynobj() + && !gsym->is_preemptible()) + break; target->make_plt_entry(symtab, layout, gsym); break; - case elfcpp::R_X86_64_GOTPC32: // TODO(csilvers): correct? + case elfcpp::R_X86_64_GOTPC32: case elfcpp::R_X86_64_GOTOFF64: - case elfcpp::R_X86_64_GOTPC64: // TODO(csilvers): correct? - case elfcpp::R_X86_64_PLTOFF64: // TODO(csilvers): correct? + case elfcpp::R_X86_64_GOTPC64: + case elfcpp::R_X86_64_PLTOFF64: // We need a GOT section. target->got_section(symtab, layout); + // For PLTOFF64, we also need a PLT entry (but only if the + // symbol is not fully resolved). + if (r_type == elfcpp::R_X86_64_PLTOFF64 + && !gsym->final_value_is_known()) + target->make_plt_entry(symtab, layout, gsym); break; case elfcpp::R_X86_64_COPY: @@ -966,80 +1448,174 @@ Target_x86_64::Scan::global(const General_options& options, break; // These are initial tls relocs, which are expected for global() - case elfcpp::R_X86_64_TLSGD: - case elfcpp::R_X86_64_TLSLD: - case elfcpp::R_X86_64_GOTTPOFF: - case elfcpp::R_X86_64_TPOFF32: - case elfcpp::R_X86_64_GOTPC32_TLSDESC: + 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 { const bool is_final = gsym->final_value_is_known(); const tls::Tls_optimization optimized_type = Target_x86_64::optimize_tls_reloc(is_final, r_type); switch (r_type) { - case elfcpp::R_X86_64_TPOFF32: // Local-exec - // FIXME: If generating a shared object, we need to copy - // this relocation into the object. - gold_assert(is_final); + 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_pair_with_rela(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, 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_GOTTPOFF: // Initial-exec - // FIXME: If not relaxing to LE, we need to generate a - // TPOFF64 reloc. - 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_DTPOFF32: - case elfcpp::R_X86_64_DTPOFF64: - // FIXME: If not relaxing to LE, we need to generate a - // DTPMOD64 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); + + // Create a double GOT entry with an R_X86_64_TLSDESC reloc. + Output_data_got<64, false>* got + = target->got_section(symtab, layout); + got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC, + target->rela_dyn_section(layout), + 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_rela(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_TLSGD: // General-dynamic - 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) - unsupported_reloc_global(object, r_type, gsym); break; - default: + case elfcpp::R_X86_64_TLSLD: // Local-dynamic + if (optimized_type == tls::TLSOPT_NONE) + { + // 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: + 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); + got->add_global_with_rela(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_local(object, r_type); + break; + + default: gold_unreachable(); } } break; - case elfcpp::R_X86_64_SIZE32: // TODO(csilvers): correct? - case elfcpp::R_X86_64_SIZE64: // TODO(csilvers): correct? + + case elfcpp::R_X86_64_SIZE32: + case elfcpp::R_X86_64_SIZE64: default: gold_error(_("%s: unsupported reloc %u against global symbol %s"), - object->name().c_str(), r_type, gsym->name()); + object->name().c_str(), r_type, + gsym->demangled_name().c_str()); break; } } +void +Target_x86_64::gc_process_relocs(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) +{ + + if (sh_type == elfcpp::SHT_REL) + { + return; + } + + gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA, + Target_x86_64::Scan>( + symtab, + layout, + this, + object, + data_shndx, + prelocs, + reloc_count, + output_section, + needs_special_offset_handling, + local_symbol_count, + plocal_symbols); + +} // Scan relocations for a section. void -Target_x86_64::scan_relocs(const General_options& options, - Symbol_table* symtab, +Target_x86_64::scan_relocs(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, - Symbol** global_symbols) + const unsigned char* plocal_symbols) { if (sh_type == elfcpp::SHT_REL) { @@ -1050,7 +1626,6 @@ Target_x86_64::scan_relocs(const General_options& options, gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA, Target_x86_64::Scan>( - options, symtab, layout, this, @@ -1058,15 +1633,16 @@ Target_x86_64::scan_relocs(const General_options& options, data_shndx, prelocs, reloc_count, + output_section, + needs_special_offset_handling, local_symbol_count, - plocal_symbols, - global_symbols); + plocal_symbols); } // Finalize the sections. void -Target_x86_64::do_finalize_sections(Layout* layout) +Target_x86_64::do_finalize_sections(Layout* layout, const Input_objects*) { // Fill in some more dynamic tags. Output_data_dynamic* const odyn = layout->dynamic_data(); @@ -1081,6 +1657,16 @@ Target_x86_64::do_finalize_sections(Layout* layout) 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->plt_->has_tlsdesc_entry()) + { + 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); + } } if (this->rela_dyn_ != NULL) @@ -1092,7 +1678,7 @@ Target_x86_64::do_finalize_sections(Layout* layout) elfcpp::Elf_sizes<64>::rela_size); } - if (!parameters->output_is_shared()) + if (!parameters->options().shared()) { // The value of the DT_DEBUG tag is filled in by the dynamic // linker at run time, and used by the debugger. @@ -1102,15 +1688,8 @@ Target_x86_64::do_finalize_sections(Layout* layout) // Emit any relocs we saved in an attempt to avoid generating COPY // relocs. - if (this->copy_relocs_ == NULL) - return; - if (this->copy_relocs_->any_to_emit()) - { - Reloc_section* rela_dyn = this->rela_dyn_section(layout); - this->copy_relocs_->emit(rela_dyn); - } - delete this->copy_relocs_; - this->copy_relocs_ = NULL; + if (this->copy_relocs_.any_saved_relocs()) + this->copy_relocs_.emit(this->rela_dyn_section(layout)); } // Perform a relocation. @@ -1118,6 +1697,7 @@ Target_x86_64::do_finalize_sections(Layout* layout) inline bool Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, Target_x86_64* target, + Output_section*, size_t relnum, const elfcpp::Rela<64, false>& rela, unsigned int r_type, @@ -1125,11 +1705,12 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, const Symbol_value<64>* psymval, unsigned char* view, elfcpp::Elf_types<64>::Elf_Addr address, - off_t view_size) + 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_PC32) || gsym == NULL || strcmp(gsym->name(), "__tls_get_addr") != 0) { @@ -1145,7 +1726,11 @@ 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 (gsym != NULL && gsym->is_from_dynobj() && gsym->has_plt_offset()) + if (gsym != NULL + && gsym->use_plt_offset(r_type == elfcpp::R_X86_64_PC64 + || r_type == elfcpp::R_X86_64_PC32 + || r_type == elfcpp::R_X86_64_PC16 + || r_type == elfcpp::R_X86_64_PC8)) { symval.set_output_value(target->plt_section()->address() + gsym->plt_offset()); @@ -1156,6 +1741,9 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, const elfcpp::Elf_Xword addend = rela.get_r_addend(); // Get the GOT offset if needed. + // The GOT pointer points to the end of the GOT section. + // We need to subtract the size of the GOT section to get + // the actual offset to use in the relocation. bool have_got_offset = false; unsigned int got_offset = 0; switch (r_type) @@ -1167,13 +1755,15 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, case elfcpp::R_X86_64_GOTPCREL64: if (gsym != NULL) { - gold_assert(gsym->has_got_offset()); - got_offset = gsym->got_offset(); + 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<64>(rela.get_r_info()); - got_offset = object->local_got_offset(r_sym); + 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; @@ -1237,12 +1827,30 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, break; case elfcpp::R_X86_64_PLT32: - gold_assert(gsym->has_plt_offset() - || gsym->final_value_is_known()); + gold_assert(gsym == NULL + || 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); 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); + } + case elfcpp::R_X86_64_GOT32: gold_assert(have_got_offset); Relocate_functions<64, false>::rela32(view, got_offset, addend); @@ -1252,7 +1860,7 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, { gold_assert(gsym); elfcpp::Elf_types<64>::Elf_Addr value; - value = target->got_section(NULL, NULL)->address(); + value = target->got_plt_section()->address(); Relocate_functions<64, false>::pcrela32(view, value, addend, address); } break; @@ -1260,7 +1868,7 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, 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: // TODO(csilvers): correct? + case elfcpp::R_X86_64_GOTPLT64: gold_assert(have_got_offset); Relocate_functions<64, false>::rela64(view, got_offset, addend); break; @@ -1269,7 +1877,7 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, { gold_assert(gsym); elfcpp::Elf_types<64>::Elf_Addr value; - value = target->got_section(NULL, NULL)->address(); + value = target->got_plt_section()->address(); Relocate_functions<64, false>::pcrela64(view, value, addend, address); } break; @@ -1278,7 +1886,7 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, { elfcpp::Elf_types<64>::Elf_Addr value; value = (psymval->value(object, 0) - - target->got_section(NULL, NULL)->address()); + - target->got_plt_section()->address()); Relocate_functions<64, false>::rela64(view, value, addend); } break; @@ -1287,7 +1895,7 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, { gold_assert(have_got_offset); elfcpp::Elf_types<64>::Elf_Addr value; - value = target->got_section(NULL, NULL)->address() + got_offset; + value = target->got_plt_section()->address() + got_offset; Relocate_functions<64, false>::pcrela32(view, value, addend, address); } break; @@ -1296,7 +1904,7 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, { gold_assert(have_got_offset); elfcpp::Elf_types<64>::Elf_Addr value; - value = target->got_section(NULL, NULL)->address() + got_offset; + value = target->got_plt_section()->address() + got_offset; Relocate_functions<64, false>::pcrela64(view, value, addend, address); } break; @@ -1315,21 +1923,20 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, break; // These are initial tls relocs, which are expected when linking - case elfcpp::R_X86_64_TLSGD: - case elfcpp::R_X86_64_TLSLD: - case elfcpp::R_X86_64_GOTTPOFF: - case elfcpp::R_X86_64_TPOFF32: - case elfcpp::R_X86_64_GOTPC32_TLSDESC: + 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: - this->relocate_tls(relinfo, relnum, rela, r_type, gsym, psymval, view, - address, view_size); + 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); break; - case elfcpp::R_X86_64_SIZE32: // TODO(csilvers): correct? - case elfcpp::R_X86_64_SIZE64: // TODO(csilvers): correct? - case elfcpp::R_X86_64_PLTOFF64: // TODO(csilvers): implement me! + case elfcpp::R_X86_64_SIZE32: + case elfcpp::R_X86_64_SIZE64: default: gold_error_at_location(relinfo, relnum, rela.get_r_offset(), _("unsupported reloc %u"), @@ -1344,147 +1951,267 @@ Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo, 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) + elfcpp::Elf_types<64>::Elf_Addr address, + section_size_type view_size) { Output_segment* tls_segment = relinfo->layout->tls_segment(); - if (tls_segment == NULL) - { - gold_error_at_location(relinfo, relnum, rela.get_r_offset(), - _("TLS reloc but no TLS segment")); - return; - } + + const Sized_relobj<64, false>* object = relinfo->object; + const elfcpp::Elf_Xword addend = rela.get_r_addend(); elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0); const bool is_final = (gsym == NULL - ? !parameters->output_is_shared() + ? !parameters->options().output_is_position_independent() : gsym->final_value_is_known()); const tls::Tls_optimization optimized_type = Target_x86_64::optimize_tls_reloc(is_final, r_type); switch (r_type) { - case elfcpp::R_X86_64_TPOFF32: // Local-exec reloc - value = value - (tls_segment->vaddr() + tls_segment->memsz()); - Relocate_functions<64, false>::rel32(view, value); - break; - - case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec reloc + case elfcpp::R_X86_64_TLSGD: // Global-dynamic + this->saw_tls_block_reloc_ = true; if (optimized_type == tls::TLSOPT_TO_LE) { - Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment, - rela, r_type, value, view, - view_size); + gold_assert(tls_segment != NULL); + this->tls_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_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<64>(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) + { + gold_assert(tls_segment != NULL); + 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<64, false>::pcrela32(view, value, addend, + address); + break; + } + } gold_error_at_location(relinfo, relnum, rela.get_r_offset(), - _("unsupported reloc type %u"), - r_type); + _("unsupported reloc %u"), r_type); break; - case elfcpp::R_X86_64_TLSGD: - case elfcpp::R_X86_64_GOTPC32_TLSDESC: + case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url) case elfcpp::R_X86_64_TLSDESC_CALL: + this->saw_tls_block_reloc_ = true; if (optimized_type == tls::TLSOPT_TO_LE) { - this->tls_gd_to_le(relinfo, relnum, tls_segment, - rela, r_type, value, view, - view_size); + gold_assert(tls_segment != NULL); + 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; + 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<64>(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) + { + gold_assert(tls_segment != NULL); + 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<64, false>::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: + case elfcpp::R_X86_64_TLSLD: // Local-dynamic + this->saw_tls_block_reloc_ = true; if (optimized_type == tls::TLSOPT_TO_LE) { + gold_assert(tls_segment != NULL); 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; + got_offset = (target->got_mod_index_entry(NULL, NULL, NULL) + - target->got_size()); + value = target->got_plt_section()->address() + got_offset; + Relocate_functions<64, false>::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: 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 we + // haven't seen a TLSLD reloc, then we assume we should not + // optimize this reloc. + if (this->saw_tls_block_reloc_) + { + gold_assert(tls_segment != NULL); + value -= tls_segment->memsz(); + } + } + Relocate_functions<64, false>::rela32(view, value, addend); break; case elfcpp::R_X86_64_DTPOFF64: 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 test this. + if (this->saw_tls_block_reloc_) + { + gold_assert(tls_segment != NULL); + value -= tls_segment->memsz(); + } + } + Relocate_functions<64, false>::rela64(view, value, addend); + break; + + case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec + if (optimized_type == tls::TLSOPT_TO_LE) + { + gold_assert(tls_segment != NULL); + 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_TYPE_TLS_OFFSET)); + got_offset = (gsym->got_offset(GOT_TYPE_TLS_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_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<64, false>::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 -= tls_segment->memsz(); + Relocate_functions<64, false>::rela32(view, value, addend); break; } } -// Do a relocation in which we convert a TLS Initial-Exec to a -// Local-Exec. +// Do a relocation in which we convert a TLS General-Dynamic to an +// Initial-Exec. inline void -Target_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo, +Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo, size_t relnum, - Output_segment* tls_segment, + Output_segment*, const elfcpp::Rela<64, false>& rela, unsigned int, elfcpp::Elf_types<64>::Elf_Addr value, unsigned char* view, - off_t view_size) + elfcpp::Elf_types<64>::Elf_Addr address, + section_size_type view_size) { - // We need to examine the opcodes to figure out which instruction we - // are looking at. + // .byte 0x66; leaq foo@tlsgd(%rip),%rdi; + // .word 0x6666; rex64; call __tls_get_addr + // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax - // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg - // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4); + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12); - 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(), + (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)); - unsigned char op1 = view[-3]; - unsigned char op2 = view[-2]; - unsigned char op3 = view[-1]; - unsigned char reg = op3 >> 3; + memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16); - if (op2 == 0x8b) - { - // movq - if (op1 == 0x4c) - view[-3] = 0x49; - view[-2] = 0xc7; - view[-1] = 0xc0 | reg; - } - else if (reg == 4) - { - // Special handling for %rsp. - if (op1 == 0x4c) - view[-3] = 0x49; - view[-2] = 0x81; - view[-1] = 0xc0 | reg; - } - else - { - // addq - if (op1 == 0x4c) - view[-3] = 0x4d; - view[-2] = 0x8d; - view[-1] = 0x80 | reg | (reg << 3); - } + const elfcpp::Elf_Xword addend = rela.get_r_addend(); + Relocate_functions<64, false>::pcrela32(view + 8, value, addend - 8, address); - value = value - (tls_segment->vaddr() + tls_segment->memsz()); - Relocate_functions<64, false>::rela32(view, 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 relocation in which we convert a TLS General-Dynamic to a @@ -1498,7 +2225,7 @@ Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo, unsigned int, elfcpp::Elf_types<64>::Elf_Addr value, unsigned char* view, - off_t view_size) + section_size_type view_size) { // .byte 0x66; leaq foo@tlsgd(%rip),%rdi; // .word 0x6666; rex64; call __tls_get_addr @@ -1514,7 +2241,7 @@ Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo, memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16); - value = value - (tls_segment->vaddr() + tls_segment->memsz()); + value -= tls_segment->memsz(); Relocate_functions<64, false>::rela32(view + 8, value, 0); // The next reloc should be a PLT32 reloc against __tls_get_addr. @@ -1522,6 +2249,84 @@ Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo, this->skip_call_tls_get_addr_ = true; } +// Do a TLSDESC-style General-Dynamic to Initial-Exec transition. + +inline void +Target_x86_64::Relocate::tls_desc_gd_to_ie( + const Relocate_info<64, false>* relinfo, + size_t relnum, + Output_segment*, + const elfcpp::Rela<64, false>& rela, + unsigned int r_type, + elfcpp::Elf_types<64>::Elf_Addr value, + unsigned char* view, + elfcpp::Elf_types<64>::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<64, false>::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. + +inline void +Target_x86_64::Relocate::tls_desc_gd_to_le( + const Relocate_info<64, false>* relinfo, + size_t relnum, + Output_segment* tls_segment, + const elfcpp::Rela<64, false>& rela, + unsigned int r_type, + elfcpp::Elf_types<64>::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<64, false>::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; + } +} + inline void Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo, size_t relnum, @@ -1530,7 +2335,7 @@ Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo, unsigned int, elfcpp::Elf_types<64>::Elf_Addr, unsigned char* view, - off_t view_size) + section_size_type view_size) { // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt; // ... leq foo@dtpoff(%rax),%reg @@ -1551,16 +2356,76 @@ Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo, this->skip_call_tls_get_addr_ = true; } +// Do a relocation in which we convert a TLS Initial-Exec to a +// Local-Exec. + +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, + section_size_type view_size) +{ + // We need to examine the opcodes to figure out which instruction we + // are looking at. + + // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg + // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg + + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3); + tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4); + + unsigned char op1 = view[-3]; + unsigned char op2 = view[-2]; + unsigned char op3 = view[-1]; + unsigned char reg = op3 >> 3; + + if (op2 == 0x8b) + { + // movq + if (op1 == 0x4c) + view[-3] = 0x49; + view[-2] = 0xc7; + view[-1] = 0xc0 | reg; + } + else if (reg == 4) + { + // Special handling for %rsp. + if (op1 == 0x4c) + view[-3] = 0x49; + view[-2] = 0x81; + view[-1] = 0xc0 | reg; + } + else + { + // addq + if (op1 == 0x4c) + view[-3] = 0x4d; + view[-2] = 0x8d; + view[-1] = 0x80 | reg | (reg << 3); + } + + value -= tls_segment->memsz(); + Relocate_functions<64, false>::rela32(view, value, 0); +} + // Relocate section data. void -Target_x86_64::relocate_section(const Relocate_info<64, false>* relinfo, - unsigned int sh_type, - const unsigned char* prelocs, - size_t reloc_count, - unsigned char* view, - elfcpp::Elf_types<64>::Elf_Addr address, - off_t view_size) +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, + section_size_type view_size, + const Reloc_symbol_changes* reloc_symbol_changes) { gold_assert(sh_type == elfcpp::SHT_RELA); @@ -1570,9 +2435,150 @@ Target_x86_64::relocate_section(const Relocate_info<64, false>* relinfo, this, prelocs, reloc_count, + output_section, + needs_special_offset_handling, view, address, - view_size); + view_size, + reloc_symbol_changes); +} + +// Return the size of a relocation while scanning during a relocatable +// link. + +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_386_GNU_VTINHERIT: + case elfcpp::R_386_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_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_PLT32: + 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: + // 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. + +void +Target_x86_64::scan_relocatable_relocs(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, + Relocatable_relocs* rr) +{ + gold_assert(sh_type == elfcpp::SHT_RELA); + + typedef gold::Default_scan_relocatable_relocs Scan_relocatable_relocs; + + gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA, + 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. + +void +Target_x86_64::relocate_for_relocatable( + const Relocate_info<64, false>* relinfo, + unsigned int sh_type, + const unsigned char* prelocs, + size_t reloc_count, + Output_section* output_section, + off_t offset_in_output_section, + const Relocatable_relocs* rr, + unsigned char* view, + elfcpp::Elf_types<64>::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_for_relocatable<64, false, elfcpp::SHT_RELA>( + 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 @@ -1591,14 +2597,14 @@ Target_x86_64::do_dynsym_value(const Symbol* gsym) const // the specified length. 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')); } @@ -1606,40 +2612,40 @@ Target_x86_64::do_code_fill(off_t length) // 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 + const char nop3[3] = { 0x0f, 0x1f, 0x00 }; // nop (%rax) + const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax) + const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1) + 0x00 }; + const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1) 0x00, 0x00 }; - const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi + const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax) 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 + const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1) + 0x00, 0x00, 0x00, 0x00 }; + const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1) + 0x00, 0x00, 0x00, 0x00, 0x00 }; - const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi - 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi + const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1) + 0x84, 0x00, 0x00, 0x00, 0x00, 0x00 }; - const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi - 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi + const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16 + 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1) 0x00, 0x00, 0x00 }; - const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi - 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi + const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16 + 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1) 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, + const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16 + 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1) + 0x00, 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, + const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16 + 0x66, 0x2e, 0x0f, 0x1f, // data16 + 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1) 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 nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16 + 0x66, 0x66, 0x2e, 0x0f, // data16; data16 + 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1) + 0x00, 0x00, 0x00 }; const char* nops[16] = { NULL, @@ -1650,33 +2656,79 @@ Target_x86_64::do_code_fill(off_t length) return std::string(nops[length], length); } +// FNOFFSET in section SHNDX in OBJECT is the start of a function +// compiled with -fstack-split. The function calls non-stack-split +// code. We have to change the function so that it always ensures +// that it has enough stack space to run some random function. + +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 +{ + // 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, "\x64\x48\x3b\x24\x25", 5) + && fnsize > 9) + { + // 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, 8); + } + // lea NN(%rsp),%r10 + else if (this->match_view(view, view_size, fnoffset, "\x4c\x8d\x94\x24", 4) + && 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, 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. -class Target_selector_x86_64 : public Target_selector +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, 64, false, "elf64-x86-64", + "elf64-x86-64-freebsd") { } Target* - recognize(int machine, int osabi, int abiversion); + do_instantiate_target() + { return new Target_x86_64(); } - private: - Target_x86_64* target_; }; -// Recognize an x86_64 object file when we already know that the machine -// number is EM_X86_64. - -Target* -Target_selector_x86_64::recognize(int, int, int) -{ - if (this->target_ == NULL) - this->target_ = new Target_x86_64(); - return this->target_; -} - Target_selector_x86_64 target_selector_x86_64; } // End anonymous namespace.