X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gold%2Flayout.cc;h=be437f3900e43484be96b20ef859b58c0b4feb5f;hb=refs%2Fheads%2Fconcurrent-displaced-stepping-2020-04-01;hp=4c48c3c4bb686d5a5b4dc8a847d6e8dc4a254197;hpb=117be58fad705e4df95c2e0bb2f3d46aa132eb20;p=deliverable%2Fbinutils-gdb.git diff --git a/gold/layout.cc b/gold/layout.cc index 4c48c3c4bb..be437f3900 100644 --- a/gold/layout.cc +++ b/gold/layout.cc @@ -1,7 +1,6 @@ // layout.cc -- lay out output file sections for gold -// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012 -// Free Software Foundation, Inc. +// Copyright (C) 2006-2020 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -35,6 +34,10 @@ #include "libiberty.h" #include "md5.h" #include "sha1.h" +#ifdef __MINGW32__ +#include +#include +#endif #include "parameters.h" #include "options.h" @@ -236,6 +239,50 @@ Free_list::print_stats() program_name, Free_list::num_allocate_visits); } +// A Hash_task computes the MD5 checksum of an array of char. + +class Hash_task : public Task +{ + public: + Hash_task(Output_file* of, + size_t offset, + size_t size, + unsigned char* dst, + Task_token* final_blocker) + : of_(of), offset_(offset), size_(size), dst_(dst), + final_blocker_(final_blocker) + { } + + void + run(Workqueue*) + { + const unsigned char* iv = + this->of_->get_input_view(this->offset_, this->size_); + md5_buffer(reinterpret_cast(iv), this->size_, this->dst_); + this->of_->free_input_view(this->offset_, this->size_, iv); + } + + Task_token* + is_runnable() + { return NULL; } + + // Unblock FINAL_BLOCKER_ when done. + void + locks(Task_locker* tl) + { tl->add(this, this->final_blocker_); } + + std::string + get_name() const + { return "Hash_task"; } + + private: + Output_file* of_; + const size_t offset_; + const size_t size_; + unsigned char* const dst_; + Task_token* const final_blocker_; +}; + // Layout::Relaxation_debug_check methods. // Check that sections and special data are in reset states. @@ -245,7 +292,8 @@ Free_list::print_stats() void Layout::Relaxation_debug_check::check_output_data_for_reset_values( const Layout::Section_list& sections, - const Layout::Data_list& special_outputs) + const Layout::Data_list& special_outputs, + const Layout::Data_list& relax_outputs) { for(Layout::Section_list::const_iterator p = sections.begin(); p != sections.end(); @@ -256,6 +304,8 @@ Layout::Relaxation_debug_check::check_output_data_for_reset_values( p != special_outputs.end(); ++p) gold_assert((*p)->address_and_file_offset_have_reset_values()); + + gold_assert(relax_outputs.empty()); } // Save information of SECTIONS for checking later. @@ -380,6 +430,7 @@ Layout::Layout(int number_of_input_files, Script_options* script_options) section_list_(), unattached_section_list_(), special_output_list_(), + relax_output_list_(), section_headers_(NULL), tls_segment_(NULL), relro_segment_(NULL), @@ -415,6 +466,7 @@ Layout::Layout(int number_of_input_files, Script_options* script_options) unique_segment_for_sections_specified_(false), incremental_inputs_(NULL), record_output_section_data_from_script_(false), + lto_slim_object_(false), script_output_section_data_list_(), segment_states_(NULL), relaxation_debug_check_(NULL), @@ -423,7 +475,8 @@ Layout::Layout(int number_of_input_files, Script_options* script_options) input_section_position_(), input_section_glob_(), incremental_base_(NULL), - free_list_() + free_list_(), + gnu_properties_() { // Make space for more than enough segments for a typical file. // This is just for efficiency--it's OK if we wind up needing more. @@ -470,6 +523,7 @@ static const char* gdb_sections[] = "addr", // Fission extension // "aranges", // not used by gdb as of 7.4 "frame", + "gdb_scripts", "info", "types", "line", @@ -478,8 +532,11 @@ static const char* gdb_sections[] = "macro", // "pubnames", // not used by gdb as of 7.4 // "pubtypes", // not used by gdb as of 7.4 + // "gnu_pubnames", // Fission extension + // "gnu_pubtypes", // Fission extension "ranges", "str", + "str_offsets", }; // This is the minimum set of sections needed for line numbers. @@ -490,6 +547,7 @@ static const char* lines_only_debug_sections[] = // "addr", // Fission extension // "aranges", // not used by gdb as of 7.4 // "frame", + // "gdb_scripts", "info", // "types", "line", @@ -498,8 +556,11 @@ static const char* lines_only_debug_sections[] = // "macro", // "pubnames", // not used by gdb as of 7.4 // "pubtypes", // not used by gdb as of 7.4 + // "gnu_pubnames", // Fission extension + // "gnu_pubtypes", // Fission extension // "ranges", "str", + "str_offsets", // Fission extension }; // These sections are the DWARF fast-lookup tables, and are not needed @@ -509,7 +570,9 @@ static const char* gdb_fast_lookup_sections[] = { "aranges", "pubnames", + "gnu_pubnames", "pubtypes", + "gnu_pubtypes", }; // Returns whether the given debug section is in the list of @@ -579,6 +642,15 @@ is_compressed_debug_section(const char* secname) return (is_prefix_of(".zdebug", secname)); } +std::string +corresponding_uncompressed_section_name(std::string secname) +{ + gold_assert(secname[0] == '.' && secname[1] == 'z'); + std::string ret("."); + ret.append(secname, 2, std::string::npos); + return ret; +} + // Whether to include this section in the link. template @@ -590,7 +662,13 @@ Layout::include_section(Sized_relobj_file*, const char* name, && (shdr.get_sh_flags() & elfcpp::SHF_EXCLUDE)) return false; - switch (shdr.get_sh_type()) + elfcpp::Elf_Word sh_type = shdr.get_sh_type(); + + if ((sh_type >= elfcpp::SHT_LOOS && sh_type <= elfcpp::SHT_HIOS) + || (sh_type >= elfcpp::SHT_LOPROC && sh_type <= elfcpp::SHT_HIPROC)) + return parameters->target().should_include_section(sh_type); + + switch (sh_type) { case elfcpp::SHT_NULL: case elfcpp::SHT_SYMTAB: @@ -827,7 +905,7 @@ Layout::keep_input_section(const Relobj* relobj, const char* name) bool keep; name = ss->output_section_name(file_name, name, &output_section_slot, - &script_section_type, &keep); + &script_section_type, &keep, true); return name != NULL && keep; } @@ -841,6 +919,7 @@ Layout::get_output_section_flags(elfcpp::Elf_Xword input_section_flags) // copied to the output section. input_section_flags &= ~ (elfcpp::SHF_INFO_LINK | elfcpp::SHF_GROUP + | elfcpp::SHF_COMPRESSED | elfcpp::SHF_MERGE | elfcpp::SHF_STRINGS); @@ -858,13 +937,16 @@ Layout::get_output_section_flags(elfcpp::Elf_Xword input_section_flags) // choosing an output section for an input section found in a input // file. ORDER is where this section should appear in the output // sections. IS_RELRO is true for a relro section. This will return -// NULL if the input section should be discarded. +// NULL if the input section should be discarded. MATCH_INPUT_SPEC +// is true if the section name should be matched against input specs +// in a linker script. Output_section* Layout::choose_output_section(const Relobj* relobj, const char* name, elfcpp::Elf_Word type, elfcpp::Elf_Xword flags, bool is_input_section, Output_section_order order, - bool is_relro) + bool is_relro, bool is_reloc, + bool match_input_spec) { // We should not see any input sections after we have attached // sections to segments. @@ -872,7 +954,7 @@ Layout::choose_output_section(const Relobj* relobj, const char* name, flags = this->get_output_section_flags(flags); - if (this->script_options_->saw_sections_clause()) + if (this->script_options_->saw_sections_clause() && !is_reloc) { // We are using a SECTIONS clause, so the output section is // chosen based only on the name. @@ -884,7 +966,8 @@ Layout::choose_output_section(const Relobj* relobj, const char* name, const char* orig_name = name; bool keep; name = ss->output_section_name(file_name, name, &output_section_slot, - &script_section_type, &keep); + &script_section_type, &keep, + match_input_spec); if (name == NULL) { @@ -958,19 +1041,16 @@ Layout::choose_output_section(const Relobj* relobj, const char* name, // FIXME: Handle SHF_OS_NONCONFORMING somewhere. size_t len = strlen(name); - char* uncompressed_name = NULL; + std::string uncompressed_name; // Compressed debug sections should be mapped to the corresponding // uncompressed section. if (is_compressed_debug_section(name)) { - uncompressed_name = new char[len]; - uncompressed_name[0] = '.'; - gold_assert(name[0] == '.' && name[1] == 'z'); - strncpy(&uncompressed_name[1], &name[2], len - 2); - uncompressed_name[len - 1] = '\0'; - len -= 1; - name = uncompressed_name; + uncompressed_name = + corresponding_uncompressed_section_name(std::string(name, len)); + name = uncompressed_name.c_str(); + len = uncompressed_name.length(); } // Turn NAME from the name of the input section into the name of the @@ -988,9 +1068,6 @@ Layout::choose_output_section(const Relobj* relobj, const char* name, Stringpool::Key name_key; name = this->namepool_.add_with_length(name, len, true, &name_key); - if (uncompressed_name != NULL) - delete[] uncompressed_name; - // Find or make the output section. The output section is selected // based on the section name, type, and flags. return this->get_output_section(name, name_key, type, flags, order, is_relro); @@ -1047,12 +1124,13 @@ Layout::special_ordering_of_input_section(const char* name) // wind up in the .text section. Sections that start with these // prefixes must appear first, and must appear in the order listed // here. - static const char* const text_section_sort[] = + static const char* const text_section_sort[] = { ".text.unlikely", ".text.exit", ".text.startup", - ".text.hot" + ".text.hot", + ".text.sorted" }; for (size_t i = 0; @@ -1078,58 +1156,86 @@ template Output_section* Layout::layout(Sized_relobj_file* object, unsigned int shndx, const char* name, const elfcpp::Shdr& shdr, - unsigned int reloc_shndx, unsigned int, off_t* off) + unsigned int sh_type, unsigned int reloc_shndx, + unsigned int, off_t* off) { *off = 0; if (!this->include_section(object, name, shdr)) return NULL; - elfcpp::Elf_Word sh_type = shdr.get_sh_type(); - // In a relocatable link a grouped section must not be combined with // any other sections. Output_section* os; if (parameters->options().relocatable() && (shdr.get_sh_flags() & elfcpp::SHF_GROUP) != 0) { + // Some flags in the input section should not be automatically + // copied to the output section. + elfcpp::Elf_Xword flags = (shdr.get_sh_flags() + & ~ elfcpp::SHF_COMPRESSED); name = this->namepool_.add(name, true, NULL); - os = this->make_output_section(name, sh_type, shdr.get_sh_flags(), + os = this->make_output_section(name, sh_type, flags, ORDER_INVALID, false); } else { - // Plugins can choose to place one or more subsets of sections in - // unique segments and this is done by mapping these section subsets - // to unique output sections. Check if this section needs to be - // remapped to a unique output section. - Section_segment_map::iterator it - = this->section_segment_map_.find(Const_section_id(object, shndx)); - if (it == this->section_segment_map_.end()) - { - os = this->choose_output_section(object, name, sh_type, - shdr.get_sh_flags(), true, - ORDER_INVALID, false); - } - else - { - // We know the name of the output section, directly call - // get_output_section here by-passing choose_output_section. + // All ".text.unlikely.*" sections can be moved to a unique + // segment with --text-unlikely-segment option. + bool text_unlikely_segment + = (parameters->options().text_unlikely_segment() + && is_prefix_of(".text.unlikely", + object->section_name(shndx).c_str())); + if (text_unlikely_segment) + { elfcpp::Elf_Xword flags = this->get_output_section_flags(shdr.get_sh_flags()); - const char* os_name = it->second->name; Stringpool::Key name_key; - os_name = this->namepool_.add(os_name, true, &name_key); + const char* os_name = this->namepool_.add(".text.unlikely", true, + &name_key); os = this->get_output_section(os_name, name_key, sh_type, flags, ORDER_INVALID, false); - if (!os->is_unique_segment()) + // Map this output section to a unique segment. This is done to + // separate "text" that is not likely to be executed from "text" + // that is likely executed. + os->set_is_unique_segment(); + } + else + { + // Plugins can choose to place one or more subsets of sections in + // unique segments and this is done by mapping these section subsets + // to unique output sections. Check if this section needs to be + // remapped to a unique output section. + Section_segment_map::iterator it + = this->section_segment_map_.find(Const_section_id(object, shndx)); + if (it == this->section_segment_map_.end()) { - os->set_is_unique_segment(); - os->set_extra_segment_flags(it->second->flags); - os->set_segment_alignment(it->second->align); + os = this->choose_output_section(object, name, sh_type, + shdr.get_sh_flags(), true, + ORDER_INVALID, false, false, + true); } - } + else + { + // We know the name of the output section, directly call + // get_output_section here by-passing choose_output_section. + elfcpp::Elf_Xword flags + = this->get_output_section_flags(shdr.get_sh_flags()); + + const char* os_name = it->second->name; + Stringpool::Key name_key; + os_name = this->namepool_.add(os_name, true, &name_key); + os = this->get_output_section(os_name, name_key, sh_type, flags, + ORDER_INVALID, false); + if (!os->is_unique_segment()) + { + os->set_is_unique_segment(); + os->set_extra_segment_flags(it->second->flags); + os->set_segment_alignment(it->second->align); + } + } + } if (os == NULL) return NULL; } @@ -1203,7 +1309,7 @@ void Layout::insert_section_segment_map(Const_section_id secn, Unique_segment_info *s) { - gold_assert(this->unique_segment_for_sections_specified_); + gold_assert(this->unique_segment_for_sections_specified_); this->section_segment_map_[secn] = s; } @@ -1211,7 +1317,7 @@ Layout::insert_section_segment_map(Const_section_id secn, template Output_section* -Layout::layout_reloc(Sized_relobj_file* object, +Layout::layout_reloc(Sized_relobj_file*, unsigned int, const elfcpp::Shdr& shdr, Output_section* data_section, @@ -1231,24 +1337,19 @@ Layout::layout_reloc(Sized_relobj_file* object, gold_unreachable(); name += data_section->name(); - // In a relocatable link relocs for a grouped section must not be - // combined with other reloc sections. - Output_section* os; - if (!parameters->options().relocatable() - || (data_section->flags() & elfcpp::SHF_GROUP) == 0) - os = this->choose_output_section(object, name.c_str(), sh_type, - shdr.get_sh_flags(), false, - ORDER_INVALID, false); - else + // If the output data section already has a reloc section, use that; + // otherwise, make a new one. + Output_section* os = data_section->reloc_section(); + if (os == NULL) { const char* n = this->namepool_.add(name.c_str(), true, NULL); os = this->make_output_section(n, sh_type, shdr.get_sh_flags(), ORDER_INVALID, false); + os->set_should_link_to_symtab(); + os->set_info_section(data_section); + data_section->set_reloc_section(os); } - os->set_should_link_to_symtab(); - os->set_info_section(data_section); - Output_section_data* posd; if (sh_type == elfcpp::SHT_REL) { @@ -1338,8 +1439,11 @@ Layout::layout_eh_frame(Sized_relobj_file* object, unsigned int reloc_shndx, unsigned int reloc_type, off_t* off) { + const unsigned int unwind_section_type = + parameters->target().unwind_section_type(); + gold_assert(shdr.get_sh_type() == elfcpp::SHT_PROGBITS - || shdr.get_sh_type() == elfcpp::SHT_X86_64_UNWIND); + || shdr.get_sh_type() == unwind_section_type); gold_assert((shdr.get_sh_flags() & elfcpp::SHF_ALLOC) != 0); Output_section* os = this->make_eh_frame_section(object); @@ -1350,15 +1454,21 @@ Layout::layout_eh_frame(Sized_relobj_file* object, elfcpp::Elf_Xword orig_flags = os->flags(); - if (!parameters->incremental() - && this->eh_frame_data_->add_ehframe_input_section(object, - symbols, - symbols_size, - symbol_names, - symbol_names_size, - shndx, - reloc_shndx, - reloc_type)) + Eh_frame::Eh_frame_section_disposition disp = + Eh_frame::EH_UNRECOGNIZED_SECTION; + if (!parameters->incremental()) + { + disp = this->eh_frame_data_->add_ehframe_input_section(object, + symbols, + symbols_size, + symbol_names, + symbol_names_size, + shndx, + reloc_shndx, + reloc_type); + } + + if (disp == Eh_frame::EH_OPTIMIZABLE_SECTION) { os->update_flags_for_input_section(shdr.get_sh_flags()); @@ -1370,35 +1480,49 @@ Layout::layout_eh_frame(Sized_relobj_file* object, os->set_order(ORDER_RELRO); } - // We found a .eh_frame section we are going to optimize, so now - // we can add the set of optimized sections to the output - // section. We need to postpone adding this until we've found a - // section we can optimize so that the .eh_frame section in - // crtbegin.o winds up at the start of the output section. - if (!this->added_eh_frame_data_) - { - os->add_output_section_data(this->eh_frame_data_); - this->added_eh_frame_data_ = true; - } *off = -1; + return os; } - else + + if (disp == Eh_frame::EH_END_MARKER_SECTION && !this->added_eh_frame_data_) { - // We couldn't handle this .eh_frame section for some reason. - // Add it as a normal section. - bool saw_sections_clause = this->script_options_->saw_sections_clause(); - *off = os->add_input_section(this, object, shndx, ".eh_frame", shdr, - reloc_shndx, saw_sections_clause); - this->have_added_input_section_ = true; + // We found the end marker section, so now we can add the set of + // optimized sections to the output section. We need to postpone + // adding this until we've found a section we can optimize so that + // the .eh_frame section in crtbeginT.o winds up at the start of + // the output section. + os->add_output_section_data(this->eh_frame_data_); + this->added_eh_frame_data_ = true; + } - if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)) - != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))) - os->set_order(this->default_section_order(os, false)); - } + // We couldn't handle this .eh_frame section for some reason. + // Add it as a normal section. + bool saw_sections_clause = this->script_options_->saw_sections_clause(); + *off = os->add_input_section(this, object, shndx, ".eh_frame", shdr, + reloc_shndx, saw_sections_clause); + this->have_added_input_section_ = true; + + if ((orig_flags & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR)) + != (os->flags() & (elfcpp::SHF_WRITE | elfcpp::SHF_EXECINSTR))) + os->set_order(this->default_section_order(os, false)); return os; } +void +Layout::finalize_eh_frame_section() +{ + // If we never found an end marker section, we need to add the + // optimized eh sections to the output section now. + if (!parameters->incremental() + && this->eh_frame_section_ != NULL + && !this->added_eh_frame_data_) + { + this->eh_frame_section_->add_output_section_data(this->eh_frame_data_); + this->added_eh_frame_data_ = true; + } +} + // Create and return the magic .eh_frame section. Create // .eh_frame_hdr also if appropriate. OBJECT is the object with the // input .eh_frame section; it may be NULL. @@ -1406,12 +1530,14 @@ Layout::layout_eh_frame(Sized_relobj_file* object, Output_section* Layout::make_eh_frame_section(const Relobj* object) { - // FIXME: On x86_64, this could use SHT_X86_64_UNWIND rather than - // SHT_PROGBITS. + const unsigned int unwind_section_type = + parameters->target().unwind_section_type(); + Output_section* os = this->choose_output_section(object, ".eh_frame", - elfcpp::SHT_PROGBITS, + unwind_section_type, elfcpp::SHF_ALLOC, false, - ORDER_EHFRAME, false); + ORDER_EHFRAME, false, false, + false); if (os == NULL) return NULL; @@ -1426,9 +1552,10 @@ Layout::make_eh_frame_section(const Relobj* object) { Output_section* hdr_os = this->choose_output_section(NULL, ".eh_frame_hdr", - elfcpp::SHT_PROGBITS, + unwind_section_type, elfcpp::SHF_ALLOC, false, - ORDER_EHFRAME, false); + ORDER_EHFRAME, false, false, + false); if (hdr_os != NULL) { @@ -1479,6 +1606,20 @@ Layout::add_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data, } } +// Remove all post-map .eh_frame information for a PLT. + +void +Layout::remove_eh_frame_for_plt(Output_data* plt, const unsigned char* cie_data, + size_t cie_length) +{ + if (parameters->incremental()) + { + // FIXME: Maybe this could work some day.... + return; + } + this->eh_frame_data_->remove_ehframe_for_plt(plt, cie_data, cie_length); +} + // Scan a .debug_info or .debug_types section, and add summary // information to the .gdb_index section. @@ -1497,7 +1638,7 @@ Layout::add_to_gdb_index(bool is_type_unit, Output_section* os = this->choose_output_section(NULL, ".gdb_index", elfcpp::SHT_PROGBITS, 0, false, ORDER_INVALID, - false); + false, false, false); if (os == NULL) return; @@ -1521,7 +1662,8 @@ Layout::add_output_section_data(const char* name, elfcpp::Elf_Word type, Output_section_order order, bool is_relro) { Output_section* os = this->choose_output_section(NULL, name, type, flags, - false, order, is_relro); + false, order, is_relro, + false, false); if (os != NULL) os->add_output_section_data(posd); return os; @@ -1658,6 +1800,10 @@ Layout::make_output_section(const char* name, elfcpp::Elf_Word type, && strcmp(name, ".text") == 0) os->set_may_sort_attached_input_sections(); + // GNU linker sorts section by name with --sort-section=name. + if (strcmp(parameters->options().sort_section(), "name") == 0) + os->set_must_sort_attached_input_sections(); + // Check for .stab*str sections, as .stab* sections need to link to // them. if (type == elfcpp::SHT_STRTAB @@ -1757,6 +1903,19 @@ Layout::default_section_order(Output_section* os, bool is_relro_local) return ORDER_INIT; else if (strcmp(os->name(), ".fini") == 0) return ORDER_FINI; + else if (parameters->options().keep_text_section_prefix()) + { + // -z,keep-text-section-prefix introduces additional + // output sections. + if (strcmp(os->name(), ".text.hot") == 0) + return ORDER_TEXT_HOT; + else if (strcmp(os->name(), ".text.startup") == 0) + return ORDER_TEXT_STARTUP; + else if (strcmp(os->name(), ".text.exit") == 0) + return ORDER_TEXT_EXIT; + else if (strcmp(os->name(), ".text.unlikely") == 0) + return ORDER_TEXT_UNLIKELY; + } } return is_execinstr ? ORDER_TEXT : ORDER_READONLY; } @@ -1839,44 +1998,44 @@ Layout::attach_allocated_section_to_segment(const Target* target, if (!os->is_unique_segment()) { for (p = this->segment_list_.begin(); - p != this->segment_list_.end(); + p != this->segment_list_.end(); ++p) { - if ((*p)->type() != elfcpp::PT_LOAD) - continue; - if ((*p)->is_unique_segment()) - continue; - if (!parameters->options().omagic() - && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W)) - continue; - if ((target->isolate_execinstr() || parameters->options().rosegment()) - && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X)) - continue; - // If -Tbss was specified, we need to separate the data and BSS - // segments. - if (parameters->options().user_set_Tbss()) - { - if ((os->type() == elfcpp::SHT_NOBITS) - == (*p)->has_any_data_sections()) - continue; - } - if (os->is_large_data_section() && !(*p)->is_large_data_segment()) - continue; - - if (is_address_set) - { - if ((*p)->are_addresses_set()) - continue; - - (*p)->add_initial_output_data(os); - (*p)->update_flags_for_output_section(seg_flags); - (*p)->set_addresses(addr, addr); - break; - } - - (*p)->add_output_section_to_load(this, os, seg_flags); - break; - } + if ((*p)->type() != elfcpp::PT_LOAD) + continue; + if ((*p)->is_unique_segment()) + continue; + if (!parameters->options().omagic() + && ((*p)->flags() & elfcpp::PF_W) != (seg_flags & elfcpp::PF_W)) + continue; + if ((target->isolate_execinstr() || parameters->options().rosegment()) + && ((*p)->flags() & elfcpp::PF_X) != (seg_flags & elfcpp::PF_X)) + continue; + // If -Tbss was specified, we need to separate the data and BSS + // segments. + if (parameters->options().user_set_Tbss()) + { + if ((os->type() == elfcpp::SHT_NOBITS) + == (*p)->has_any_data_sections()) + continue; + } + if (os->is_large_data_section() && !(*p)->is_large_data_segment()) + continue; + + if (is_address_set) + { + if ((*p)->are_addresses_set()) + continue; + + (*p)->add_initial_output_data(os); + (*p)->update_flags_for_output_section(seg_flags); + (*p)->set_addresses(addr, addr); + break; + } + + (*p)->add_output_section_to_load(this, os, seg_flags); + break; + } } if (p == this->segment_list_.end() @@ -2027,21 +2186,252 @@ Layout::layout_gnu_stack(bool seen_gnu_stack, uint64_t gnu_stack_flags, if ((gnu_stack_flags & elfcpp::SHF_EXECINSTR) != 0) { this->input_requires_executable_stack_ = true; - if (parameters->options().warn_execstack() - || parameters->options().is_stack_executable()) + if (parameters->options().warn_execstack()) gold_warning(_("%s: requires executable stack"), obj->name().c_str()); } } } +// Read a value with given size and endianness. + +static inline uint64_t +read_sized_value(size_t size, const unsigned char* buf, bool is_big_endian, + const Object* object) +{ + uint64_t val = 0; + if (size == 4) + { + if (is_big_endian) + val = elfcpp::Swap<32, true>::readval(buf); + else + val = elfcpp::Swap<32, false>::readval(buf); + } + else if (size == 8) + { + if (is_big_endian) + val = elfcpp::Swap<64, true>::readval(buf); + else + val = elfcpp::Swap<64, false>::readval(buf); + } + else + { + gold_warning(_("%s: in .note.gnu.property section, " + "pr_datasz must be 4 or 8"), + object->name().c_str()); + } + return val; +} + +// Write a value with given size and endianness. + +static inline void +write_sized_value(uint64_t value, size_t size, unsigned char* buf, + bool is_big_endian) +{ + if (size == 4) + { + if (is_big_endian) + elfcpp::Swap<32, true>::writeval(buf, static_cast(value)); + else + elfcpp::Swap<32, false>::writeval(buf, static_cast(value)); + } + else if (size == 8) + { + if (is_big_endian) + elfcpp::Swap<64, true>::writeval(buf, value); + else + elfcpp::Swap<64, false>::writeval(buf, value); + } + else + { + // We will have already complained about this. + } +} + +// Handle the .note.gnu.property section at layout time. + +void +Layout::layout_gnu_property(unsigned int note_type, + unsigned int pr_type, + size_t pr_datasz, + const unsigned char* pr_data, + const Object* object) +{ + // We currently support only the one note type. + gold_assert(note_type == elfcpp::NT_GNU_PROPERTY_TYPE_0); + + if (pr_type >= elfcpp::GNU_PROPERTY_LOPROC + && pr_type < elfcpp::GNU_PROPERTY_HIPROC) + { + // Target-dependent property value; call the target to record. + const int size = parameters->target().get_size(); + const bool is_big_endian = parameters->target().is_big_endian(); + if (size == 32) + { + if (is_big_endian) + { +#ifdef HAVE_TARGET_32_BIG + parameters->sized_target<32, true>()-> + record_gnu_property(note_type, pr_type, pr_datasz, pr_data, + object); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_32_LITTLE + parameters->sized_target<32, false>()-> + record_gnu_property(note_type, pr_type, pr_datasz, pr_data, + object); +#else + gold_unreachable(); +#endif + } + } + else if (size == 64) + { + if (is_big_endian) + { +#ifdef HAVE_TARGET_64_BIG + parameters->sized_target<64, true>()-> + record_gnu_property(note_type, pr_type, pr_datasz, pr_data, + object); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_64_LITTLE + parameters->sized_target<64, false>()-> + record_gnu_property(note_type, pr_type, pr_datasz, pr_data, + object); +#else + gold_unreachable(); +#endif + } + } + else + gold_unreachable(); + return; + } + + Gnu_properties::iterator pprop = this->gnu_properties_.find(pr_type); + if (pprop == this->gnu_properties_.end()) + { + Gnu_property prop; + prop.pr_datasz = pr_datasz; + prop.pr_data = new unsigned char[pr_datasz]; + memcpy(prop.pr_data, pr_data, pr_datasz); + this->gnu_properties_[pr_type] = prop; + } + else + { + const bool is_big_endian = parameters->target().is_big_endian(); + switch (pr_type) + { + case elfcpp::GNU_PROPERTY_STACK_SIZE: + // Record the maximum value seen. + { + uint64_t val1 = read_sized_value(pprop->second.pr_datasz, + pprop->second.pr_data, + is_big_endian, object); + uint64_t val2 = read_sized_value(pr_datasz, pr_data, + is_big_endian, object); + if (val2 > val1) + write_sized_value(val2, pprop->second.pr_datasz, + pprop->second.pr_data, is_big_endian); + } + break; + case elfcpp::GNU_PROPERTY_NO_COPY_ON_PROTECTED: + // No data to merge. + break; + default: + gold_warning(_("%s: unknown program property type %d " + "in .note.gnu.property section"), + object->name().c_str(), pr_type); + } + } +} + +// Merge per-object properties with program properties. +// This lets the target identify objects that are missing certain +// properties, in cases where properties must be ANDed together. + +void +Layout::merge_gnu_properties(const Object* object) +{ + const int size = parameters->target().get_size(); + const bool is_big_endian = parameters->target().is_big_endian(); + if (size == 32) + { + if (is_big_endian) + { +#ifdef HAVE_TARGET_32_BIG + parameters->sized_target<32, true>()->merge_gnu_properties(object); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_32_LITTLE + parameters->sized_target<32, false>()->merge_gnu_properties(object); +#else + gold_unreachable(); +#endif + } + } + else if (size == 64) + { + if (is_big_endian) + { +#ifdef HAVE_TARGET_64_BIG + parameters->sized_target<64, true>()->merge_gnu_properties(object); +#else + gold_unreachable(); +#endif + } + else + { +#ifdef HAVE_TARGET_64_LITTLE + parameters->sized_target<64, false>()->merge_gnu_properties(object); +#else + gold_unreachable(); +#endif + } + } + else + gold_unreachable(); +} + +// Add a target-specific property for the output .note.gnu.property section. + +void +Layout::add_gnu_property(unsigned int note_type, + unsigned int pr_type, + size_t pr_datasz, + const unsigned char* pr_data) +{ + gold_assert(note_type == elfcpp::NT_GNU_PROPERTY_TYPE_0); + + Gnu_property prop; + prop.pr_datasz = pr_datasz; + prop.pr_data = new unsigned char[pr_datasz]; + memcpy(prop.pr_data, pr_data, pr_datasz); + this->gnu_properties_[pr_type] = prop; +} + // Create automatic note sections. void Layout::create_notes() { + this->create_gnu_properties_note(); this->create_gold_note(); - this->create_executable_stack_info(); + this->create_stack_segment(); this->create_build_id(); } @@ -2059,7 +2449,7 @@ Layout::create_initial_dynamic_sections(Symbol_table* symtab) (elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE), false, ORDER_RELRO, - true); + true, false, false); // A linker script may discard .dynamic, so check for NULL. if (this->dynamic_section_ != NULL) @@ -2105,7 +2495,7 @@ Layout::define_section_symbols(Symbol_table* symtab) 0, // symsize elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, - elfcpp::STV_DEFAULT, + elfcpp::STV_PROTECTED, 0, // nonvis false, // offset_is_from_end true); // only_if_ref @@ -2118,7 +2508,7 @@ Layout::define_section_symbols(Symbol_table* symtab) 0, // symsize elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, - elfcpp::STV_DEFAULT, + elfcpp::STV_PROTECTED, 0, // nonvis true, // offset_is_from_end true); // only_if_ref @@ -2286,6 +2676,20 @@ Layout::clean_up_after_relaxation() ++p) delete *p; this->script_output_section_data_list_.clear(); + + // Special-case fill output objects are recreated each time through + // the relaxation loop. + this->reset_relax_output(); +} + +void +Layout::reset_relax_output() +{ + for (Data_list::const_iterator p = this->relax_output_list_.begin(); + p != this->relax_output_list_.end(); + ++p) + delete *p; + this->relax_output_list_.clear(); } // Prepare for relaxation. @@ -2308,12 +2712,29 @@ Layout::prepare_for_relaxation() if (is_debugging_enabled(DEBUG_RELAXATION)) this->relaxation_debug_check_->check_output_data_for_reset_values( - this->section_list_, this->special_output_list_); + this->section_list_, this->special_output_list_, + this->relax_output_list_); // Also enable recording of output section data from scripts. this->record_output_section_data_from_script_ = true; } +// If the user set the address of the text segment, that may not be +// compatible with putting the segment headers and file headers into +// that segment. For isolate_execinstr() targets, it's the rodata +// segment rather than text where we might put the headers. +static inline bool +load_seg_unusable_for_headers(const Target* target) +{ + const General_options& options = parameters->options(); + if (target->isolate_execinstr()) + return (options.user_set_Trodata_segment() + && options.Trodata_segment() % target->abi_pagesize() != 0); + else + return (options.user_set_Ttext() + && options.Ttext() % target->abi_pagesize() != 0); +} + // Relaxation loop body: If target has no relaxation, this runs only once // Otherwise, the target relaxation hook is called at the end of // each iteration. If the hook returns true, it means re-layout of @@ -2366,11 +2787,7 @@ Layout::relaxation_loop_body( != General_options::OBJECT_FORMAT_ELF) load_seg = NULL; - // If the user set the address of the text segment, that may not be - // compatible with putting the segment headers and file headers into - // that segment. - if (parameters->options().user_set_Ttext() - && parameters->options().Ttext() % target->abi_pagesize() != 0) + if (load_seg_unusable_for_headers(target)) { load_seg = NULL; phdr_seg = NULL; @@ -2460,7 +2877,7 @@ Layout::relaxation_loop_body( return off; } -// Search the list of patterns and find the postion of the given section +// Search the list of patterns and find the position of the given section // name in the output section. If the section name matches a glob // pattern and a non-glob name, then the non-glob position takes // precedence. Return 0 if no match is found. @@ -2563,6 +2980,9 @@ off_t Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab, Target* target, const Task* task) { + unsigned int local_dynamic_count = 0; + unsigned int forced_local_dynamic_count = 0; + target->finalize_sections(this, input_objects, symtab); this->count_local_symbols(task, input_objects); @@ -2583,11 +3003,12 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab, // Create the dynamic symbol table, including the hash table. Output_section* dynstr; std::vector dynamic_symbols; - unsigned int local_dynamic_count; Versions versions(*this->script_options()->version_script_info(), &this->dynpool_); this->create_dynamic_symtab(input_objects, symtab, &dynstr, - &local_dynamic_count, &dynamic_symbols, + &local_dynamic_count, + &forced_local_dynamic_count, + &dynamic_symbols, &versions); // Create the .interp section to hold the name of the @@ -2608,7 +3029,9 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab, // Create the version sections. We can't do this until the // dynamic string table is complete. - this->create_version_sections(&versions, symtab, local_dynamic_count, + this->create_version_sections(&versions, symtab, + (local_dynamic_count + + forced_local_dynamic_count), dynamic_symbols, dynstr); // Set the size of the _DYNAMIC symbol. We can't do this until @@ -2658,12 +3081,14 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab, // If there is a load segment that contains the file and program headers, // provide a symbol __ehdr_start pointing there. // A program can use this to examine itself robustly. - if (load_seg != NULL) - symtab->define_in_output_segment("__ehdr_start", NULL, - Symbol_table::PREDEFINED, load_seg, 0, 0, - elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL, - elfcpp::STV_DEFAULT, 0, - Symbol::SEGMENT_START, true); + Symbol *ehdr_start = symtab->lookup("__ehdr_start"); + if (ehdr_start != NULL && ehdr_start->is_predefined()) + { + if (load_seg != NULL) + ehdr_start->set_output_segment(load_seg, Symbol::SEGMENT_START); + else + ehdr_start->set_undefined(); + } // Set the file offsets of all the non-data sections we've seen so // far which don't have to wait for the input sections. We need @@ -2676,7 +3101,8 @@ Layout::finalize(const Input_objects* input_objects, Symbol_table* symtab, shndx = this->set_section_indexes(shndx); // Create the symbol table sections. - this->create_symtab_sections(input_objects, symtab, shndx, &off); + this->create_symtab_sections(input_objects, symtab, shndx, &off, + local_dynamic_count); if (!parameters->doing_static_link()) this->assign_local_dynsym_offsets(input_objects); @@ -2812,7 +3238,8 @@ Layout::create_note(const char* name, int note_type, } Output_section* os = this->choose_output_section(NULL, section_name, elfcpp::SHT_NOTE, - flags, false, order, false); + flags, false, order, false, + false, true); if (os == NULL) return NULL; @@ -2826,6 +3253,58 @@ Layout::create_note(const char* name, int note_type, return os; } +// Create a .note.gnu.property section to record program properties +// accumulated from the input files. + +void +Layout::create_gnu_properties_note() +{ + parameters->target().finalize_gnu_properties(this); + + if (this->gnu_properties_.empty()) + return; + + const unsigned int size = parameters->target().get_size(); + const bool is_big_endian = parameters->target().is_big_endian(); + + // Compute the total size of the properties array. + size_t descsz = 0; + for (Gnu_properties::const_iterator prop = this->gnu_properties_.begin(); + prop != this->gnu_properties_.end(); + ++prop) + { + descsz = align_address(descsz + 8 + prop->second.pr_datasz, size / 8); + } + + // Create the note section. + size_t trailing_padding; + Output_section* os = this->create_note("GNU", elfcpp::NT_GNU_PROPERTY_TYPE_0, + ".note.gnu.property", descsz, + true, &trailing_padding); + if (os == NULL) + return; + gold_assert(trailing_padding == 0); + + // Allocate and fill the properties array. + unsigned char* desc = new unsigned char[descsz]; + unsigned char* p = desc; + for (Gnu_properties::const_iterator prop = this->gnu_properties_.begin(); + prop != this->gnu_properties_.end(); + ++prop) + { + size_t datasz = prop->second.pr_datasz; + size_t aligned_datasz = align_address(prop->second.pr_datasz, size / 8); + write_sized_value(prop->first, 4, p, is_big_endian); + write_sized_value(datasz, 4, p + 4, is_big_endian); + memcpy(p + 8, prop->second.pr_data, datasz); + if (aligned_datasz > datasz) + memset(p + 8 + datasz, 0, aligned_datasz - datasz); + p += 8 + aligned_datasz; + } + Output_section_data* posd = new Output_data_const(desc, descsz, 4); + os->add_output_section_data(posd); +} + // For an executable or shared library, create a note to record the // version of gold used to create the binary. @@ -2862,18 +3341,29 @@ Layout::create_gold_note() // executable. Otherwise, if at least one input file a // .note.GNU-stack section, and some input file has no .note.GNU-stack // section, we use the target default for whether the stack should be -// executable. Otherwise, we don't generate a stack note. When -// generating a object file, we create a .note.GNU-stack section with -// the appropriate marking. When generating an executable or shared -// library, we create a PT_GNU_STACK segment. +// executable. If -z stack-size was used to set a p_memsz value for +// PT_GNU_STACK, we generate the segment regardless. Otherwise, we +// don't generate a stack note. When generating a object file, we +// create a .note.GNU-stack section with the appropriate marking. +// When generating an executable or shared library, we create a +// PT_GNU_STACK segment. void -Layout::create_executable_stack_info() +Layout::create_stack_segment() { bool is_stack_executable; if (parameters->options().is_execstack_set()) - is_stack_executable = parameters->options().is_stack_executable(); - else if (!this->input_with_gnu_stack_note_) + { + is_stack_executable = parameters->options().is_stack_executable(); + if (!is_stack_executable + && this->input_requires_executable_stack_ + && parameters->options().warn_execstack()) + gold_warning(_("one or more inputs require executable stack, " + "but -z noexecstack was given")); + } + else if (!this->input_with_gnu_stack_note_ + && (!parameters->options().user_set_stack_size() + || parameters->options().relocatable())) return; else { @@ -2902,7 +3392,12 @@ Layout::create_executable_stack_info() int flags = elfcpp::PF_R | elfcpp::PF_W; if (is_stack_executable) flags |= elfcpp::PF_X; - this->make_output_segment(elfcpp::PT_GNU_STACK, flags); + Output_segment* seg = + this->make_output_segment(elfcpp::PT_GNU_STACK, flags); + seg->set_size(parameters->options().stack_size()); + // BFD lets targets override this default alignment, but the only + // targets that do so are ones that Gold does not support so far. + seg->set_minimum_p_align(16); } } @@ -2924,10 +3419,11 @@ Layout::create_build_id() std::string desc; if (strcmp(style, "md5") == 0) descsz = 128 / 8; - else if (strcmp(style, "sha1") == 0) + else if ((strcmp(style, "sha1") == 0) || (strcmp(style, "tree") == 0)) descsz = 160 / 8; else if (strcmp(style, "uuid") == 0) { +#ifndef __MINGW32__ const size_t uuidsz = 128 / 8; char buffer[uuidsz]; @@ -2950,6 +3446,26 @@ Layout::create_build_id() desc.assign(buffer, uuidsz); descsz = uuidsz; +#else // __MINGW32__ + UUID uuid; + typedef RPC_STATUS (RPC_ENTRY *UuidCreateFn)(UUID *Uuid); + + HMODULE rpc_library = LoadLibrary("rpcrt4.dll"); + if (!rpc_library) + gold_error(_("--build-id=uuid failed: could not load rpcrt4.dll")); + else + { + UuidCreateFn uuid_create = reinterpret_cast( + GetProcAddress(rpc_library, "UuidCreate")); + if (!uuid_create) + gold_error(_("--build-id=uuid failed: could not find UuidCreate")); + else if (uuid_create(&uuid) != RPC_S_OK) + gold_error(_("__build_id=uuid failed: call UuidCreate() failed")); + FreeLibrary(rpc_library); + } + desc.assign(reinterpret_cast(&uuid), sizeof(UUID)); + descsz = sizeof(UUID); +#endif // __MINGW32__ } else if (strncmp(style, "0x", 2) == 0) { @@ -3120,6 +3636,11 @@ bool Layout::segment_precedes(const Output_segment* seg1, const Output_segment* seg2) { + // In order to produce a stable ordering if we're called with the same pointer + // return false. + if (seg1 == seg2) + return false; + elfcpp::Elf_Word type1 = seg1->type(); elfcpp::Elf_Word type2 = seg2->type(); @@ -3175,12 +3696,14 @@ Layout::segment_precedes(const Output_segment* seg1, // The order of non-PT_LOAD segments is unimportant. We simply sort // by the numeric segment type and flags values. There should not - // be more than one segment with the same type and flags. + // be more than one segment with the same type and flags, except + // when a linker script specifies such. if (type1 != elfcpp::PT_LOAD) { if (type1 != type2) return type1 < type2; - gold_assert(flags1 != flags2); + gold_assert(flags1 != flags2 + || this->script_options_->saw_phdrs_clause()); return flags1 < flags2; } @@ -3245,7 +3768,8 @@ Layout::segment_precedes(const Output_segment* seg1, // here if plugins want unique segments for subsets of sections. gold_assert(this->script_options_->saw_phdrs_clause() || parameters->options().any_section_start() - || this->is_unique_segment_for_sections_specified()); + || this->is_unique_segment_for_sections_specified() + || parameters->options().text_unlikely_segment()); return false; } @@ -3262,8 +3786,22 @@ align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize) return aligned_off; } +// On targets where the text segment contains only executable code, +// a non-executable segment is never the text segment. + +static inline bool +is_text_segment(const Target* target, const Output_segment* seg) +{ + elfcpp::Elf_Xword flags = seg->flags(); + if ((flags & elfcpp::PF_W) != 0) + return false; + if ((flags & elfcpp::PF_X) == 0) + return !target->isolate_execinstr(); + return true; +} + // Set the file offsets of all the segments, and all the sections they -// contain. They have all been created. LOAD_SEG must be be laid out +// contain. They have all been created. LOAD_SEG must be laid out // first. Return the offset of the data to follow. off_t @@ -3353,10 +3891,17 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, addr = (*p)->paddr(); } else if (parameters->options().user_set_Ttext() - && ((*p)->flags() & elfcpp::PF_W) == 0) + && (parameters->options().omagic() + || is_text_segment(target, *p))) { are_addresses_set = true; } + else if (parameters->options().user_set_Trodata_segment() + && ((*p)->flags() & (elfcpp::PF_W | elfcpp::PF_X)) == 0) + { + addr = parameters->options().Trodata_segment(); + are_addresses_set = true; + } else if (parameters->options().user_set_Tdata() && ((*p)->flags() & elfcpp::PF_W) != 0 && (!parameters->options().user_set_Tbss() @@ -3392,7 +3937,9 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, // put them on different pages in memory. We will revisit this // decision once we know the size of the segment. - addr = align_address(addr, (*p)->maximum_alignment()); + uint64_t max_align = (*p)->maximum_alignment(); + if (max_align > abi_pagesize) + addr = align_address(addr, max_align); aligned_addr = addr; if (load_seg == *p) @@ -3403,7 +3950,10 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, // If the target wants a fixed minimum distance from the // text segment to the read-only segment, move up now. - uint64_t min_addr = start_addr + target->rosegment_gap(); + uint64_t min_addr = + start_addr + (parameters->options().user_set_rosegment_gap() + ? parameters->options().rosegment_gap() + : target->rosegment_gap()); if (addr < min_addr) addr = min_addr; @@ -3424,7 +3974,13 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, if (!parameters->options().nmagic() && !parameters->options().omagic()) - off = align_file_offset(off, addr, abi_pagesize); + { + // Here we are also taking care of the case when + // the maximum segment alignment is larger than the page size. + off = align_file_offset(off, addr, + std::max(abi_pagesize, + (*p)->maximum_alignment())); + } else { // This is -N or -n with a section script which prevents @@ -3441,7 +3997,8 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, unsigned int shndx_hold = *pshndx; bool has_relro = false; - uint64_t new_addr = (*p)->set_section_addresses(this, false, addr, + uint64_t new_addr = (*p)->set_section_addresses(target, this, + false, addr, &increase_relro, &has_relro, &off, pshndx); @@ -3482,7 +4039,8 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, increase_relro = 0; has_relro = false; - new_addr = (*p)->set_section_addresses(this, true, addr, + new_addr = (*p)->set_section_addresses(target, this, + true, addr, &increase_relro, &has_relro, &off, pshndx); @@ -3518,6 +4076,8 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, // so they land after the segments starting at LOAD_SEG. off = align_file_offset(off, 0, target->abi_pagesize()); + this->reset_relax_output(); + for (Segment_list::iterator p = this->segment_list_.begin(); *p != load_seg; ++p) @@ -3531,8 +4091,8 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, bool has_relro = false; const uint64_t old_addr = (*p)->vaddr(); const uint64_t old_end = old_addr + (*p)->memsz(); - uint64_t new_addr = (*p)->set_section_addresses(this, true, - old_addr, + uint64_t new_addr = (*p)->set_section_addresses(target, this, + true, old_addr, &increase_relro, &has_relro, &off, @@ -3550,7 +4110,9 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, p != this->segment_list_.end(); ++p) { - if ((*p)->type() != elfcpp::PT_LOAD) + // PT_GNU_STACK was set up correctly when it was created. + if ((*p)->type() != elfcpp::PT_LOAD + && (*p)->type() != elfcpp::PT_GNU_STACK) (*p)->set_offset((*p)->type() == elfcpp::PT_GNU_RELRO ? increase_relro : 0); @@ -3593,7 +4155,8 @@ Layout::set_relocatable_section_offsets(Output_data* file_header, (*p)->set_address(0); (*p)->set_file_offset(off); (*p)->finalize_data_size(); - off += (*p)->data_size(); + if ((*p)->type() != elfcpp::SHT_NOBITS) + off += (*p)->data_size(); (*p)->set_out_shndx(*pshndx); ++*pshndx; @@ -3785,7 +4348,8 @@ void Layout::create_symtab_sections(const Input_objects* input_objects, Symbol_table* symtab, unsigned int shnum, - off_t* poff) + off_t* poff, + unsigned int local_dynamic_count) { int symsize; unsigned int align; @@ -3839,18 +4403,15 @@ Layout::create_symtab_sections(const Input_objects* input_objects, gold_assert(static_cast(local_symcount * symsize) == off); off_t dynoff; - size_t dyn_global_index; size_t dyncount; if (this->dynsym_section_ == NULL) { dynoff = 0; - dyn_global_index = 0; dyncount = 0; } else { - dyn_global_index = this->dynsym_section_->info(); - off_t locsize = dyn_global_index * this->dynsym_section_->entsize(); + off_t locsize = local_dynamic_count * this->dynsym_section_->entsize(); dynoff = this->dynsym_section_->offset() + locsize; dyncount = (this->dynsym_section_->data_size() - locsize) / symsize; gold_assert(static_cast(dyncount * symsize) @@ -3858,7 +4419,7 @@ Layout::create_symtab_sections(const Input_objects* input_objects, } off_t global_off = off; - off = symtab->finalize(off, dynoff, dyn_global_index, dyncount, + off = symtab->finalize(off, dynoff, local_dynamic_count, dyncount, &this->sympool_, &local_symcount); if (!parameters->options().strip_all()) @@ -4024,12 +4585,18 @@ Layout::allocated_output_section_count() const } // Create the dynamic symbol table. +// *PLOCAL_DYNAMIC_COUNT will be set to the number of local symbols +// from input objects, and *PFORCED_LOCAL_DYNAMIC_COUNT will be set +// to the number of global symbols that have been forced local. +// We need to remember the former because the forced-local symbols are +// written along with the global symbols in Symtab::write_globals(). void Layout::create_dynamic_symtab(const Input_objects* input_objects, Symbol_table* symtab, Output_section** pdynstr, unsigned int* plocal_dynamic_count, + unsigned int* pforced_local_dynamic_count, std::vector* pdynamic_symbols, Versions* pversions) { @@ -4064,10 +4631,14 @@ Layout::create_dynamic_symtab(const Input_objects* input_objects, } unsigned int local_symcount = index; - *plocal_dynamic_count = local_symcount; + unsigned int forced_local_count = 0; - index = symtab->set_dynsym_indexes(index, pdynamic_symbols, - &this->dynpool_, pversions); + index = symtab->set_dynsym_indexes(index, &forced_local_count, + pdynamic_symbols, &this->dynpool_, + pversions); + + *plocal_dynamic_count = local_symcount; + *pforced_local_dynamic_count = forced_local_count; int symsize; unsigned int align; @@ -4092,7 +4663,7 @@ Layout::create_dynamic_symtab(const Input_objects* input_objects, elfcpp::SHF_ALLOC, false, ORDER_DYNAMIC_LINKER, - false); + false, false, false); // Check for NULL as a linker script may discard .dynsym. if (dynsym != NULL) @@ -4102,7 +4673,7 @@ Layout::create_dynamic_symtab(const Input_objects* input_objects, "** dynsym"); dynsym->add_output_section_data(odata); - dynsym->set_info(local_symcount); + dynsym->set_info(local_symcount + forced_local_count); dynsym->set_entsize(symsize); dynsym->set_addralign(align); @@ -4129,7 +4700,8 @@ Layout::create_dynamic_symtab(const Input_objects* input_objects, this->choose_output_section(NULL, ".dynsym_shndx", elfcpp::SHT_SYMTAB_SHNDX, elfcpp::SHF_ALLOC, - false, ORDER_DYNAMIC_LINKER, false); + false, ORDER_DYNAMIC_LINKER, false, false, + false); if (dynsym_xindex != NULL) { @@ -4157,7 +4729,7 @@ Layout::create_dynamic_symtab(const Input_objects* input_objects, elfcpp::SHF_ALLOC, false, ORDER_DYNAMIC_LINKER, - false); + false, false, false); *pdynstr = dynstr; if (dynstr != NULL) { @@ -4176,20 +4748,24 @@ Layout::create_dynamic_symtab(const Input_objects* input_objects, } } - // Create the hash tables. + // Create the hash tables. The Gnu-style hash table must be + // built first, because it changes the order of the symbols + // in the dynamic symbol table. - if (strcmp(parameters->options().hash_style(), "sysv") == 0 + if (strcmp(parameters->options().hash_style(), "gnu") == 0 || strcmp(parameters->options().hash_style(), "both") == 0) { unsigned char* phash; unsigned int hashlen; - Dynobj::create_elf_hash_table(*pdynamic_symbols, local_symcount, + Dynobj::create_gnu_hash_table(*pdynamic_symbols, + local_symcount + forced_local_count, &phash, &hashlen); Output_section* hashsec = - this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH, + this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH, elfcpp::SHF_ALLOC, false, - ORDER_DYNAMIC_LINKER, false); + ORDER_DYNAMIC_LINKER, false, false, + false); Output_section_data* hashdata = new Output_data_const_buffer(phash, hashlen, @@ -4202,25 +4778,32 @@ Layout::create_dynamic_symtab(const Input_objects* input_objects, { if (dynsym != NULL) hashsec->set_link_section(dynsym); - hashsec->set_entsize(4); - } - if (odyn != NULL) - odyn->add_section_address(elfcpp::DT_HASH, hashsec); + // For a 64-bit target, the entries in .gnu.hash do not have + // a uniform size, so we only set the entry size for a + // 32-bit target. + if (parameters->target().get_size() == 32) + hashsec->set_entsize(4); + + if (odyn != NULL) + odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec); + } } - if (strcmp(parameters->options().hash_style(), "gnu") == 0 + if (strcmp(parameters->options().hash_style(), "sysv") == 0 || strcmp(parameters->options().hash_style(), "both") == 0) { unsigned char* phash; unsigned int hashlen; - Dynobj::create_gnu_hash_table(*pdynamic_symbols, local_symcount, + Dynobj::create_elf_hash_table(*pdynamic_symbols, + local_symcount + forced_local_count, &phash, &hashlen); Output_section* hashsec = - this->choose_output_section(NULL, ".gnu.hash", elfcpp::SHT_GNU_HASH, + this->choose_output_section(NULL, ".hash", elfcpp::SHT_HASH, elfcpp::SHF_ALLOC, false, - ORDER_DYNAMIC_LINKER, false); + ORDER_DYNAMIC_LINKER, false, false, + false); Output_section_data* hashdata = new Output_data_const_buffer(phash, hashlen, @@ -4233,16 +4816,11 @@ Layout::create_dynamic_symtab(const Input_objects* input_objects, { if (dynsym != NULL) hashsec->set_link_section(dynsym); - - // For a 64-bit target, the entries in .gnu.hash do not have - // a uniform size, so we only set the entry size for a - // 32-bit target. - if (parameters->target().get_size() == 32) - hashsec->set_entsize(4); - - if (odyn != NULL) - odyn->add_section_address(elfcpp::DT_GNU_HASH, hashsec); + hashsec->set_entsize(parameters->target().hash_entry_size() / 8); } + + if (odyn != NULL) + odyn->add_section_address(elfcpp::DT_HASH, hashsec); } } @@ -4332,7 +4910,7 @@ Layout::sized_create_version_sections( elfcpp::SHF_ALLOC, false, ORDER_DYNAMIC_LINKER, - false); + false, false, false); // Check for NULL since a linker script may discard this section. if (vsec != NULL) @@ -4363,7 +4941,8 @@ Layout::sized_create_version_sections( vdsec = this->choose_output_section(NULL, ".gnu.version_d", elfcpp::SHT_GNU_verdef, elfcpp::SHF_ALLOC, - false, ORDER_DYNAMIC_LINKER, false); + false, ORDER_DYNAMIC_LINKER, false, + false, false); if (vdsec != NULL) { @@ -4395,7 +4974,8 @@ Layout::sized_create_version_sections( vnsec = this->choose_output_section(NULL, ".gnu.version_r", elfcpp::SHT_GNU_verneed, elfcpp::SHF_ALLOC, - false, ORDER_DYNAMIC_LINKER, false); + false, ORDER_DYNAMIC_LINKER, false, + false, false); if (vnsec != NULL) { @@ -4444,7 +5024,7 @@ Layout::create_interp(const Target* target) elfcpp::SHT_PROGBITS, elfcpp::SHF_ALLOC, false, ORDER_INTERP, - false); + false, false, false); if (osec != NULL) osec->add_output_section_data(odata); } @@ -4553,6 +5133,15 @@ Layout::add_target_dynamic_tags(bool use_rel, const Output_data* plt_got, } } +void +Layout::add_target_specific_dynamic_tag(elfcpp::DT tag, unsigned int val) +{ + Output_data_dynamic* odyn = this->dynamic_data_; + if (odyn == NULL) + return; + odyn->add_constant(tag, val); +} + // Finish the .dynamic section and PT_DYNAMIC segment. void @@ -4723,7 +5312,8 @@ Layout::finish_dynamic_section(const Input_objects* input_objects, flags |= elfcpp::DF_STATIC_TLS; if (parameters->options().origin()) flags |= elfcpp::DF_ORIGIN; - if (parameters->options().Bsymbolic()) + if (parameters->options().Bsymbolic() + && !parameters->options().have_dynamic_list()) { flags |= elfcpp::DF_SYMBOLIC; // Add DT_SYMBOLIC for compatibility with older loaders. @@ -4735,6 +5325,8 @@ Layout::finish_dynamic_section(const Input_objects* input_objects, odyn->add_constant(elfcpp::DT_FLAGS, flags); flags = 0; + if (parameters->options().global()) + flags |= elfcpp::DF_1_GLOBAL; if (parameters->options().initfirst()) flags |= elfcpp::DF_1_INITFIRST; if (parameters->options().interpose()) @@ -4836,6 +5428,21 @@ const Layout::Section_name_mapping Layout::section_name_mapping[] = MAPPING_INIT(".gnu.linkonce.armextab.", ".ARM.extab"), MAPPING_INIT(".ARM.exidx", ".ARM.exidx"), MAPPING_INIT(".gnu.linkonce.armexidx.", ".ARM.exidx"), + MAPPING_INIT(".gnu.build.attributes.", ".gnu.build.attributes"), +}; + +// Mapping for ".text" section prefixes with -z,keep-text-section-prefix. +const Layout::Section_name_mapping Layout::text_section_name_mapping[] = +{ + MAPPING_INIT(".text.hot.", ".text.hot"), + MAPPING_INIT_EXACT(".text.hot", ".text.hot"), + MAPPING_INIT(".text.unlikely.", ".text.unlikely"), + MAPPING_INIT_EXACT(".text.unlikely", ".text.unlikely"), + MAPPING_INIT(".text.startup.", ".text.startup"), + MAPPING_INIT_EXACT(".text.startup", ".text.startup"), + MAPPING_INIT(".text.exit.", ".text.exit"), + MAPPING_INIT_EXACT(".text.exit", ".text.exit"), + MAPPING_INIT(".text.", ".text"), }; #undef MAPPING_INIT #undef MAPPING_INIT_EXACT @@ -4844,6 +5451,39 @@ const int Layout::section_name_mapping_count = (sizeof(Layout::section_name_mapping) / sizeof(Layout::section_name_mapping[0])); +const int Layout::text_section_name_mapping_count = + (sizeof(Layout::text_section_name_mapping) + / sizeof(Layout::text_section_name_mapping[0])); + +// Find section name NAME in PSNM and return the mapped name if found +// with the length set in PLEN. +const char * +Layout::match_section_name(const Layout::Section_name_mapping* psnm, + const int count, + const char* name, size_t* plen) +{ + for (int i = 0; i < count; ++i, ++psnm) + { + if (psnm->fromlen > 0) + { + if (strncmp(name, psnm->from, psnm->fromlen) == 0) + { + *plen = psnm->tolen; + return psnm->to; + } + } + else + { + if (strcmp(name, psnm->from) == 0) + { + *plen = psnm->tolen; + return psnm->to; + } + } + } + return NULL; +} + // Choose the output section name to use given an input section name. // Set *PLEN to the length of the name. *PLEN is initialized to the // length of NAME. @@ -4887,27 +5527,21 @@ Layout::output_section_name(const Relobj* relobj, const char* name, // not found in the table, we simply use it as the output section // name. - const Section_name_mapping* psnm = section_name_mapping; - for (int i = 0; i < section_name_mapping_count; ++i, ++psnm) + if (parameters->options().keep_text_section_prefix() + && is_prefix_of(".text", name)) { - if (psnm->fromlen > 0) - { - if (strncmp(name, psnm->from, psnm->fromlen) == 0) - { - *plen = psnm->tolen; - return psnm->to; - } - } - else - { - if (strcmp(name, psnm->from) == 0) - { - *plen = psnm->tolen; - return psnm->to; - } - } + const char* match = match_section_name(text_section_name_mapping, + text_section_name_mapping_count, + name, plen); + if (match != NULL) + return match; } + const char* match = match_section_name(section_name_mapping, + section_name_mapping_count, name, plen); + if (match != NULL) + return match; + // As an additional complication, .ctors sections are output in // either .ctors or .init_array sections, and .dtors sections are // output in either .dtors or .fini_array sections. @@ -5168,6 +5802,13 @@ Layout::write_data(const Symbol_table* symtab, Output_file* of) const p != this->special_output_list_.end(); ++p) (*p)->write(of); + + // Write out the Output_data which are not in an Output_section + // and are regenerated in each iteration of relaxation. + for (Data_list::const_iterator p = this->relax_output_list_.begin(); + p != this->relax_output_list_.end(); + ++p) + (*p)->write(of); } // Write out the Output_sections which can only be written after the @@ -5208,44 +5849,49 @@ Layout::write_sections_after_input_sections(Output_file* of) this->section_headers_->write(of); } -// If the build ID requires computing a checksum, do so here, and -// write it out. We compute a checksum over the entire file because -// that is simplest. +// If a tree-style build ID was requested, the parallel part of that computation +// is already done, and the final hash-of-hashes is computed here. For other +// types of build IDs, all the work is done here. void -Layout::write_build_id(Output_file* of) const +Layout::write_build_id(Output_file* of, unsigned char* array_of_hashes, + size_t size_of_hashes) const { if (this->build_id_note_ == NULL) return; - const unsigned char* iv = of->get_input_view(0, this->output_file_size_); - unsigned char* ov = of->get_output_view(this->build_id_note_->offset(), this->build_id_note_->data_size()); - const char* style = parameters->options().build_id(); - if (strcmp(style, "sha1") == 0) + if (array_of_hashes == NULL) { - sha1_ctx ctx; - sha1_init_ctx(&ctx); - sha1_process_bytes(iv, this->output_file_size_, &ctx); - sha1_finish_ctx(&ctx, ov); + const size_t output_file_size = this->output_file_size(); + const unsigned char* iv = of->get_input_view(0, output_file_size); + const char* style = parameters->options().build_id(); + + // If we get here with style == "tree" then the output must be + // too small for chunking, and we use SHA-1 in that case. + if ((strcmp(style, "sha1") == 0) || (strcmp(style, "tree") == 0)) + sha1_buffer(reinterpret_cast(iv), output_file_size, ov); + else if (strcmp(style, "md5") == 0) + md5_buffer(reinterpret_cast(iv), output_file_size, ov); + else + gold_unreachable(); + + of->free_input_view(0, output_file_size, iv); } - else if (strcmp(style, "md5") == 0) + else { - md5_ctx ctx; - md5_init_ctx(&ctx); - md5_process_bytes(iv, this->output_file_size_, &ctx); - md5_finish_ctx(&ctx, ov); + // Non-overlapping substrings of the output file have been hashed. + // Compute SHA-1 hash of the hashes. + sha1_buffer(reinterpret_cast(array_of_hashes), + size_of_hashes, ov); + delete[] array_of_hashes; } - else - gold_unreachable(); of->write_output_view(this->build_id_note_->offset(), this->build_id_note_->data_size(), ov); - - of->free_input_view(0, this->output_file_size_, iv); } // Write out a binary file. This is called after the link is @@ -5306,6 +5952,10 @@ Layout::print_to_mapfile(Mapfile* mapfile) const p != this->segment_list_.end(); ++p) (*p)->print_sections_to_mapfile(mapfile); + for (Section_list::const_iterator p = this->unattached_section_list_.begin(); + p != this->unattached_section_list_.end(); + ++p) + (*p)->print_to_mapfile(mapfile); } // Print statistical information to stderr. This is used for --stats. @@ -5340,6 +5990,8 @@ void Write_sections_task::locks(Task_locker* tl) { tl->add(this, this->output_sections_blocker_); + if (this->input_sections_blocker_ != NULL) + tl->add(this, this->input_sections_blocker_); tl->add(this, this->final_blocker_); } @@ -5433,15 +6085,69 @@ Write_after_input_sections_task::run(Workqueue*) this->layout_->write_sections_after_input_sections(this->of_); } +// Build IDs can be computed as a "flat" sha1 or md5 of a string of bytes, +// or as a "tree" where each chunk of the string is hashed and then those +// hashes are put into a (much smaller) string which is hashed with sha1. +// We compute a checksum over the entire file because that is simplest. + +void +Build_id_task_runner::run(Workqueue* workqueue, const Task*) +{ + Task_token* post_hash_tasks_blocker = new Task_token(true); + const Layout* layout = this->layout_; + Output_file* of = this->of_; + const size_t filesize = (layout->output_file_size() <= 0 ? 0 + : static_cast(layout->output_file_size())); + unsigned char* array_of_hashes = NULL; + size_t size_of_hashes = 0; + + if (strcmp(this->options_->build_id(), "tree") == 0 + && this->options_->build_id_chunk_size_for_treehash() > 0 + && filesize > 0 + && (filesize >= this->options_->build_id_min_file_size_for_treehash())) + { + static const size_t MD5_OUTPUT_SIZE_IN_BYTES = 16; + const size_t chunk_size = + this->options_->build_id_chunk_size_for_treehash(); + const size_t num_hashes = ((filesize - 1) / chunk_size) + 1; + post_hash_tasks_blocker->add_blockers(num_hashes); + size_of_hashes = num_hashes * MD5_OUTPUT_SIZE_IN_BYTES; + array_of_hashes = new unsigned char[size_of_hashes]; + unsigned char *dst = array_of_hashes; + for (size_t i = 0, src_offset = 0; i < num_hashes; + i++, dst += MD5_OUTPUT_SIZE_IN_BYTES, src_offset += chunk_size) + { + size_t size = std::min(chunk_size, filesize - src_offset); + workqueue->queue(new Hash_task(of, + src_offset, + size, + dst, + post_hash_tasks_blocker)); + } + } + + // Queue the final task to write the build id and close the output file. + workqueue->queue(new Task_function(new Close_task_runner(this->options_, + layout, + of, + array_of_hashes, + size_of_hashes), + post_hash_tasks_blocker, + "Task_function Close_task_runner")); +} + // Close_task_runner methods. -// Run the task--close the file. +// Finish up the build ID computation, if necessary, and write a binary file, +// if necessary. Then close the output file. void Close_task_runner::run(Workqueue*, const Task*) { - // If we need to compute a checksum for the BUILD if, we do so here. - this->layout_->write_build_id(this->of_); + // At this point the multi-threaded part of the build ID computation, + // if any, is done. See Build_id_task_runner. + this->layout_->write_build_id(this->of_, this->array_of_hashes_, + this->size_of_hashes_); // If we've been asked to create a binary file, we do so here. if (this->options_->oformat_enum() != General_options::OBJECT_FORMAT_ELF) @@ -5492,7 +6198,7 @@ Layout::layout<32, false>(Sized_relobj_file<32, false>* object, unsigned int shndx, const char* name, const elfcpp::Shdr<32, false>& shdr, - unsigned int, unsigned int, off_t*); + unsigned int, unsigned int, unsigned int, off_t*); #endif #ifdef HAVE_TARGET_32_BIG @@ -5502,7 +6208,7 @@ Layout::layout<32, true>(Sized_relobj_file<32, true>* object, unsigned int shndx, const char* name, const elfcpp::Shdr<32, true>& shdr, - unsigned int, unsigned int, off_t*); + unsigned int, unsigned int, unsigned int, off_t*); #endif #ifdef HAVE_TARGET_64_LITTLE @@ -5512,7 +6218,7 @@ Layout::layout<64, false>(Sized_relobj_file<64, false>* object, unsigned int shndx, const char* name, const elfcpp::Shdr<64, false>& shdr, - unsigned int, unsigned int, off_t*); + unsigned int, unsigned int, unsigned int, off_t*); #endif #ifdef HAVE_TARGET_64_BIG @@ -5522,7 +6228,7 @@ Layout::layout<64, true>(Sized_relobj_file<64, true>* object, unsigned int shndx, const char* name, const elfcpp::Shdr<64, true>& shdr, - unsigned int, unsigned int, off_t*); + unsigned int, unsigned int, unsigned int, off_t*); #endif #ifdef HAVE_TARGET_32_LITTLE