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8a5e3e08a6
Target::new_output_section. (Layout::attach_allocated_section_to_segment): Put large section sections in a separate load segment with the large segment flag set. (Layout::segment_precedes): Sort large data segments after other load segments. (align_file_offset): New static function. (Layout::set_segment_offsets): Use align_file_offset. * output.h (class Output_section): Add is_small_section_ and is_large_section_ fields. (Output_section::is_small_section): New function. (Output_section::set_is_small_section): New function. (Output_section::is_large_section): New function. (Output_section::set_is_large_section): New function. (Output_section::is_large_data_section): New function. (class Output_segment): Add is_large_data_segment_ field. (Output_segment::is_large_data_segment): New function. (Output_segment::set_is_large_data_segment): New function. * output.cc (Output_section::Output_section): Initialize new fields. (Output_segment::Output_segment): Likewise. (Output_segment::add_output_section): Add assertion that large data sections always go in large data segments. Force small data sections to the end of the list of data sections. Force small BSS sections to the start of the list of BSS sections. For large BSS sections to the end of the list of BSS sections. * symtab.h (class Symbol): Declare is_common_shndx. (Symbol::is_defined): Check Symbol::is_common_shndx. (Symbol::is_common): Likewise. (class Symbol_table): Define enum Commons_section_type. Update declarations. Add small_commons_ and large_commons_ fields. * symtab.cc (Symbol::is_common_shndx): New function. (Symbol_table::Symbol_table): Initialize new fields. (Symbol_table::add_from_object): Put small and large common symbols in the right list. (Symbol_table::sized_finalized_symbol): Check Symbol::is_common_shndx. (Symbol_table::sized_write_globals): Likewise. * common.cc (Symbol_table::do_allocate_commons): Allocate new common symbol lists. Don't call do_allocate_commons_list if the list is empty. (Symbol_table::do_allocate_commons_list): Remove is_tls parameter. Add comons_section_type parameter. Change all callers. Handle small and large common symbols. * object.cc (Sized_relobj::do_finalize_local_symbols): Check Symbol::is_common_shndx. * resolve.cc (symbol_to_bits): Likewise. * target.h (Target::small_common_shndx): New function. (Target::small_common_section_flags): New function. (Target::large_common_shndx): New function. (Target::large_common_section_flags): New function. (Target::new_output_section): New function. (Target::Target_info): Add small_common_shndx, large_common_shndx, small_common_section_flags, and large_common_section_flags fields. (Target::do_new_output_section): New virtual function. * arm.cc (Target_arm::arm_info): Initialize new fields. * i386.cc (Target_i386::i386_info): Likewise. * powerpc.cc (Target_powerpc::powerpc_info) [all versions]: Likewise. * sparc.c (Target_sparc::sparc_info) [all versions]: Likewise. * x86_64.cc (Target_x86_64::x86_64_info): Likewise. (Target_x86_64::do_new_output_section): New function. * configure.ac: Define conditional MCMODEL_MEDIUM. * testsuite/Makefile.am (check_PROGRAMS): Add large. (large_SOURCES, large_CFLAGS, large_DEPENDENCIES): Define. (large_LDFLAGS): Define. * testsuite/large.c: New file. * testsuite/testfile.cc (Target_test::test_target_info): Initialize new fields. * configure, testsuite/Makefile.in: Rebuild.
2696 lines
89 KiB
C++
2696 lines
89 KiB
C++
// i386.cc -- i386 target support for gold.
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// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
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// Written by Ian Lance Taylor <iant@google.com>.
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// This file is part of gold.
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 3 of the License, or
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// (at your option) any later version.
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
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// MA 02110-1301, USA.
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#include "gold.h"
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#include <cstring>
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#include "elfcpp.h"
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#include "parameters.h"
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#include "reloc.h"
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#include "i386.h"
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#include "object.h"
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#include "symtab.h"
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#include "layout.h"
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#include "output.h"
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#include "copy-relocs.h"
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#include "target.h"
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#include "target-reloc.h"
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#include "target-select.h"
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#include "tls.h"
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#include "freebsd.h"
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namespace
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{
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using namespace gold;
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class Output_data_plt_i386;
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// The i386 target class.
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// TLS info comes from
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// http://people.redhat.com/drepper/tls.pdf
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// http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
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class Target_i386 : public Target_freebsd<32, false>
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{
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public:
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typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
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Target_i386()
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: Target_freebsd<32, false>(&i386_info),
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got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
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copy_relocs_(elfcpp::R_386_COPY), dynbss_(NULL),
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got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
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{ }
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// Process the relocations to determine unreferenced sections for
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// garbage collection.
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void
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gc_process_relocs(const General_options& options,
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Symbol_table* symtab,
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Layout* layout,
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Sized_relobj<32, false>* object,
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unsigned int data_shndx,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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bool needs_special_offset_handling,
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size_t local_symbol_count,
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const unsigned char* plocal_symbols);
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// Scan the relocations to look for symbol adjustments.
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void
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scan_relocs(const General_options& options,
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Symbol_table* symtab,
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Layout* layout,
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Sized_relobj<32, false>* object,
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unsigned int data_shndx,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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bool needs_special_offset_handling,
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size_t local_symbol_count,
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const unsigned char* plocal_symbols);
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// Finalize the sections.
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void
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do_finalize_sections(Layout*);
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// Return the value to use for a dynamic which requires special
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// treatment.
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uint64_t
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do_dynsym_value(const Symbol*) const;
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// Relocate a section.
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void
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relocate_section(const Relocate_info<32, false>*,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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bool needs_special_offset_handling,
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unsigned char* view,
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elfcpp::Elf_types<32>::Elf_Addr view_address,
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section_size_type view_size);
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// Scan the relocs during a relocatable link.
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void
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scan_relocatable_relocs(const General_options& options,
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Symbol_table* symtab,
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Layout* layout,
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Sized_relobj<32, false>* object,
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unsigned int data_shndx,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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bool needs_special_offset_handling,
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size_t local_symbol_count,
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const unsigned char* plocal_symbols,
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Relocatable_relocs*);
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// Relocate a section during a relocatable link.
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void
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relocate_for_relocatable(const Relocate_info<32, false>*,
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unsigned int sh_type,
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const unsigned char* prelocs,
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size_t reloc_count,
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Output_section* output_section,
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off_t offset_in_output_section,
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const Relocatable_relocs*,
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unsigned char* view,
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elfcpp::Elf_types<32>::Elf_Addr view_address,
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section_size_type view_size,
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unsigned char* reloc_view,
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section_size_type reloc_view_size);
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// Return a string used to fill a code section with nops.
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std::string
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do_code_fill(section_size_type length) const;
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// Return whether SYM is defined by the ABI.
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bool
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do_is_defined_by_abi(const Symbol* sym) const
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{ return strcmp(sym->name(), "___tls_get_addr") == 0; }
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// Return whether a symbol name implies a local label. The UnixWare
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// 2.1 cc generates temporary symbols that start with .X, so we
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// recognize them here. FIXME: do other SVR4 compilers also use .X?.
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// If so, we should move the .X recognition into
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// Target::do_is_local_label_name.
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bool
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do_is_local_label_name(const char* name) const
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{
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if (name[0] == '.' && name[1] == 'X')
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return true;
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return Target::do_is_local_label_name(name);
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}
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// Return the size of the GOT section.
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section_size_type
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got_size()
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{
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gold_assert(this->got_ != NULL);
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return this->got_->data_size();
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}
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private:
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// The class which scans relocations.
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struct Scan
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{
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inline void
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local(const General_options& options, Symbol_table* symtab,
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Layout* layout, Target_i386* target,
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Sized_relobj<32, false>* object,
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unsigned int data_shndx,
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Output_section* output_section,
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const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
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const elfcpp::Sym<32, false>& lsym);
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inline void
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global(const General_options& options, Symbol_table* symtab,
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Layout* layout, Target_i386* target,
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Sized_relobj<32, false>* object,
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unsigned int data_shndx,
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Output_section* output_section,
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const elfcpp::Rel<32, false>& reloc, unsigned int r_type,
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Symbol* gsym);
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static void
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unsupported_reloc_local(Sized_relobj<32, false>*, unsigned int r_type);
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static void
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unsupported_reloc_global(Sized_relobj<32, false>*, unsigned int r_type,
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Symbol*);
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};
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// The class which implements relocation.
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class Relocate
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{
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public:
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Relocate()
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: skip_call_tls_get_addr_(false),
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local_dynamic_type_(LOCAL_DYNAMIC_NONE)
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{ }
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~Relocate()
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{
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if (this->skip_call_tls_get_addr_)
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{
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// FIXME: This needs to specify the location somehow.
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gold_error(_("missing expected TLS relocation"));
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}
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}
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// Return whether the static relocation needs to be applied.
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inline bool
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should_apply_static_reloc(const Sized_symbol<32>* gsym,
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int ref_flags,
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bool is_32bit,
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Output_section* output_section);
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// Do a relocation. Return false if the caller should not issue
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// any warnings about this relocation.
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inline bool
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relocate(const Relocate_info<32, false>*, Target_i386*, Output_section*,
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size_t relnum, const elfcpp::Rel<32, false>&,
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unsigned int r_type, const Sized_symbol<32>*,
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const Symbol_value<32>*,
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unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
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section_size_type);
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private:
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// Do a TLS relocation.
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inline void
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relocate_tls(const Relocate_info<32, false>*, Target_i386* target,
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size_t relnum, const elfcpp::Rel<32, false>&,
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unsigned int r_type, const Sized_symbol<32>*,
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const Symbol_value<32>*,
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unsigned char*, elfcpp::Elf_types<32>::Elf_Addr,
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section_size_type);
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// Do a TLS General-Dynamic to Initial-Exec transition.
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inline void
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tls_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
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Output_segment* tls_segment,
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const elfcpp::Rel<32, false>&, unsigned int r_type,
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elfcpp::Elf_types<32>::Elf_Addr value,
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unsigned char* view,
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section_size_type view_size);
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// Do a TLS General-Dynamic to Local-Exec transition.
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inline void
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tls_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
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Output_segment* tls_segment,
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const elfcpp::Rel<32, false>&, unsigned int r_type,
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elfcpp::Elf_types<32>::Elf_Addr value,
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unsigned char* view,
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section_size_type view_size);
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// Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Initial-Exec
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// transition.
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inline void
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tls_desc_gd_to_ie(const Relocate_info<32, false>*, size_t relnum,
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Output_segment* tls_segment,
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const elfcpp::Rel<32, false>&, unsigned int r_type,
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elfcpp::Elf_types<32>::Elf_Addr value,
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unsigned char* view,
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section_size_type view_size);
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// Do a TLS_GOTDESC or TLS_DESC_CALL General-Dynamic to Local-Exec
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// transition.
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inline void
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tls_desc_gd_to_le(const Relocate_info<32, false>*, size_t relnum,
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Output_segment* tls_segment,
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const elfcpp::Rel<32, false>&, unsigned int r_type,
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elfcpp::Elf_types<32>::Elf_Addr value,
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unsigned char* view,
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section_size_type view_size);
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// Do a TLS Local-Dynamic to Local-Exec transition.
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inline void
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tls_ld_to_le(const Relocate_info<32, false>*, size_t relnum,
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Output_segment* tls_segment,
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const elfcpp::Rel<32, false>&, unsigned int r_type,
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elfcpp::Elf_types<32>::Elf_Addr value,
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unsigned char* view,
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section_size_type view_size);
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// Do a TLS Initial-Exec to Local-Exec transition.
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static inline void
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tls_ie_to_le(const Relocate_info<32, false>*, size_t relnum,
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Output_segment* tls_segment,
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const elfcpp::Rel<32, false>&, unsigned int r_type,
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elfcpp::Elf_types<32>::Elf_Addr value,
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unsigned char* view,
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section_size_type view_size);
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// We need to keep track of which type of local dynamic relocation
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// we have seen, so that we can optimize R_386_TLS_LDO_32 correctly.
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enum Local_dynamic_type
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{
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LOCAL_DYNAMIC_NONE,
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LOCAL_DYNAMIC_SUN,
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LOCAL_DYNAMIC_GNU
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};
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// This is set if we should skip the next reloc, which should be a
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// PLT32 reloc against ___tls_get_addr.
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bool skip_call_tls_get_addr_;
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// The type of local dynamic relocation we have seen in the section
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// being relocated, if any.
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Local_dynamic_type local_dynamic_type_;
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};
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// A class which returns the size required for a relocation type,
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// used while scanning relocs during a relocatable link.
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class Relocatable_size_for_reloc
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{
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public:
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unsigned int
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get_size_for_reloc(unsigned int, Relobj*);
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};
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// Adjust TLS relocation type based on the options and whether this
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// is a local symbol.
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static tls::Tls_optimization
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optimize_tls_reloc(bool is_final, int r_type);
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// Get the GOT section, creating it if necessary.
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Output_data_got<32, false>*
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got_section(Symbol_table*, Layout*);
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// Get the GOT PLT section.
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Output_data_space*
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got_plt_section() const
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{
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gold_assert(this->got_plt_ != NULL);
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return this->got_plt_;
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}
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// Create a PLT entry for a global symbol.
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void
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make_plt_entry(Symbol_table*, Layout*, Symbol*);
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// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
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void
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define_tls_base_symbol(Symbol_table*, Layout*);
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// Create a GOT entry for the TLS module index.
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unsigned int
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got_mod_index_entry(Symbol_table* symtab, Layout* layout,
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Sized_relobj<32, false>* object);
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// Get the PLT section.
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const Output_data_plt_i386*
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plt_section() const
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{
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gold_assert(this->plt_ != NULL);
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return this->plt_;
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}
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// Get the dynamic reloc section, creating it if necessary.
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Reloc_section*
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rel_dyn_section(Layout*);
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// Return true if the symbol may need a COPY relocation.
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// References from an executable object to non-function symbols
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// defined in a dynamic object may need a COPY relocation.
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bool
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may_need_copy_reloc(Symbol* gsym)
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{
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return (!parameters->options().shared()
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&& gsym->is_from_dynobj()
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&& gsym->type() != elfcpp::STT_FUNC);
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}
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// Add a potential copy relocation.
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void
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copy_reloc(Symbol_table* symtab, Layout* layout,
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Sized_relobj<32, false>* object,
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unsigned int shndx, Output_section* output_section,
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Symbol* sym, const elfcpp::Rel<32, false>& reloc)
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{
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this->copy_relocs_.copy_reloc(symtab, layout,
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symtab->get_sized_symbol<32>(sym),
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object, shndx, output_section, reloc,
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this->rel_dyn_section(layout));
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}
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// Information about this specific target which we pass to the
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// general Target structure.
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static const Target::Target_info i386_info;
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// The types of GOT entries needed for this platform.
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enum Got_type
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{
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GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
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GOT_TYPE_TLS_NOFFSET = 1, // GOT entry for negative TLS offset
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GOT_TYPE_TLS_OFFSET = 2, // GOT entry for positive TLS offset
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GOT_TYPE_TLS_PAIR = 3, // GOT entry for TLS module/offset pair
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GOT_TYPE_TLS_DESC = 4 // GOT entry for TLS_DESC pair
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};
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// The GOT section.
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Output_data_got<32, false>* got_;
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// The PLT section.
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Output_data_plt_i386* plt_;
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// The GOT PLT section.
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Output_data_space* got_plt_;
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// The dynamic reloc section.
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Reloc_section* rel_dyn_;
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// Relocs saved to avoid a COPY reloc.
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Copy_relocs<elfcpp::SHT_REL, 32, false> copy_relocs_;
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// Space for variables copied with a COPY reloc.
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Output_data_space* dynbss_;
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// Offset of the GOT entry for the TLS module index.
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unsigned int got_mod_index_offset_;
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// True if the _TLS_MODULE_BASE_ symbol has been defined.
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bool tls_base_symbol_defined_;
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};
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const Target::Target_info Target_i386::i386_info =
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{
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32, // size
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false, // is_big_endian
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elfcpp::EM_386, // machine_code
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false, // has_make_symbol
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false, // has_resolve
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true, // has_code_fill
|
|
true, // is_default_stack_executable
|
|
'\0', // wrap_char
|
|
"/usr/lib/libc.so.1", // dynamic_linker
|
|
0x08048000, // 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_UNDEF, // large_common_shndx
|
|
0, // small_common_section_flags
|
|
0 // large_common_section_flags
|
|
};
|
|
|
|
// Get the GOT section, creating it if necessary.
|
|
|
|
Output_data_got<32, false>*
|
|
Target_i386::got_section(Symbol_table* symtab, Layout* layout)
|
|
{
|
|
if (this->got_ == NULL)
|
|
{
|
|
gold_assert(symtab != NULL && layout != NULL);
|
|
|
|
this->got_ = new Output_data_got<32, false>();
|
|
|
|
Output_section* os;
|
|
os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
|
|
(elfcpp::SHF_ALLOC
|
|
| elfcpp::SHF_WRITE),
|
|
this->got_);
|
|
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.
|
|
this->got_plt_ = new Output_data_space(4, "** GOT PLT");
|
|
os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
|
|
(elfcpp::SHF_ALLOC
|
|
| elfcpp::SHF_WRITE),
|
|
this->got_plt_);
|
|
os->set_is_relro();
|
|
|
|
// The first three entries are reserved.
|
|
this->got_plt_->set_current_data_size(3 * 4);
|
|
|
|
// Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
|
|
symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
|
|
this->got_plt_,
|
|
0, 0, elfcpp::STT_OBJECT,
|
|
elfcpp::STB_LOCAL,
|
|
elfcpp::STV_HIDDEN, 0,
|
|
false, false);
|
|
}
|
|
|
|
return this->got_;
|
|
}
|
|
|
|
// Get the dynamic reloc section, creating it if necessary.
|
|
|
|
Target_i386::Reloc_section*
|
|
Target_i386::rel_dyn_section(Layout* layout)
|
|
{
|
|
if (this->rel_dyn_ == NULL)
|
|
{
|
|
gold_assert(layout != NULL);
|
|
this->rel_dyn_ = new Reloc_section(parameters->options().combreloc());
|
|
layout->add_output_section_data(".rel.dyn", elfcpp::SHT_REL,
|
|
elfcpp::SHF_ALLOC, this->rel_dyn_);
|
|
}
|
|
return this->rel_dyn_;
|
|
}
|
|
|
|
// A class to handle the PLT data.
|
|
|
|
class Output_data_plt_i386 : public Output_section_data
|
|
{
|
|
public:
|
|
typedef Output_data_reloc<elfcpp::SHT_REL, true, 32, false> Reloc_section;
|
|
|
|
Output_data_plt_i386(Layout*, Output_data_space*);
|
|
|
|
// Add an entry to the PLT.
|
|
void
|
|
add_entry(Symbol* gsym);
|
|
|
|
// Return the .rel.plt section data.
|
|
const Reloc_section*
|
|
rel_plt() const
|
|
{ return this->rel_; }
|
|
|
|
protected:
|
|
void
|
|
do_adjust_output_section(Output_section* os);
|
|
|
|
// 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;
|
|
|
|
// The first entry in the PLT for an executable.
|
|
static unsigned char exec_first_plt_entry[plt_entry_size];
|
|
|
|
// The first entry in the PLT for a shared object.
|
|
static unsigned char dyn_first_plt_entry[plt_entry_size];
|
|
|
|
// Other entries in the PLT for an executable.
|
|
static unsigned char exec_plt_entry[plt_entry_size];
|
|
|
|
// Other entries in the PLT for a shared object.
|
|
static unsigned char dyn_plt_entry[plt_entry_size];
|
|
|
|
// Set the final size.
|
|
void
|
|
set_final_data_size()
|
|
{ this->set_data_size((this->count_ + 1) * plt_entry_size); }
|
|
|
|
// Write out the PLT data.
|
|
void
|
|
do_write(Output_file*);
|
|
|
|
// The reloc section.
|
|
Reloc_section* rel_;
|
|
// The .got.plt section.
|
|
Output_data_space* got_plt_;
|
|
// The number of PLT entries.
|
|
unsigned int count_;
|
|
};
|
|
|
|
// Create the PLT section. The ordinary .got section is an argument,
|
|
// since we need to refer to the start. We also create our own .got
|
|
// section just for PLT entries.
|
|
|
|
Output_data_plt_i386::Output_data_plt_i386(Layout* layout,
|
|
Output_data_space* got_plt)
|
|
: Output_section_data(4), got_plt_(got_plt), count_(0)
|
|
{
|
|
this->rel_ = new Reloc_section(false);
|
|
layout->add_output_section_data(".rel.plt", elfcpp::SHT_REL,
|
|
elfcpp::SHF_ALLOC, this->rel_);
|
|
}
|
|
|
|
void
|
|
Output_data_plt_i386::do_adjust_output_section(Output_section* os)
|
|
{
|
|
// UnixWare sets the entsize of .plt to 4, and so does the old GNU
|
|
// linker, and so do we.
|
|
os->set_entsize(4);
|
|
}
|
|
|
|
// Add an entry to the PLT.
|
|
|
|
void
|
|
Output_data_plt_i386::add_entry(Symbol* gsym)
|
|
{
|
|
gold_assert(!gsym->has_plt_offset());
|
|
|
|
// Note that when setting the PLT offset we skip the initial
|
|
// reserved PLT entry.
|
|
gsym->set_plt_offset((this->count_ + 1) * plt_entry_size);
|
|
|
|
++this->count_;
|
|
|
|
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_current_data_size(got_offset + 4);
|
|
|
|
// Every PLT entry needs a reloc.
|
|
gsym->set_needs_dynsym_entry();
|
|
this->rel_->add_global(gsym, elfcpp::R_386_JUMP_SLOT, this->got_plt_,
|
|
got_offset);
|
|
|
|
// Note that we don't need to save the symbol. The contents of the
|
|
// PLT are independent of which symbols are used. The symbols only
|
|
// appear in the relocations.
|
|
}
|
|
|
|
// The first entry in the PLT for an executable.
|
|
|
|
unsigned char Output_data_plt_i386::exec_first_plt_entry[plt_entry_size] =
|
|
{
|
|
0xff, 0x35, // pushl contents of memory address
|
|
0, 0, 0, 0, // replaced with address of .got + 4
|
|
0xff, 0x25, // jmp indirect
|
|
0, 0, 0, 0, // replaced with address of .got + 8
|
|
0, 0, 0, 0 // unused
|
|
};
|
|
|
|
// The first entry in the PLT for a shared object.
|
|
|
|
unsigned char Output_data_plt_i386::dyn_first_plt_entry[plt_entry_size] =
|
|
{
|
|
0xff, 0xb3, 4, 0, 0, 0, // pushl 4(%ebx)
|
|
0xff, 0xa3, 8, 0, 0, 0, // jmp *8(%ebx)
|
|
0, 0, 0, 0 // unused
|
|
};
|
|
|
|
// Subsequent entries in the PLT for an executable.
|
|
|
|
unsigned char Output_data_plt_i386::exec_plt_entry[plt_entry_size] =
|
|
{
|
|
0xff, 0x25, // jmp indirect
|
|
0, 0, 0, 0, // replaced with address of symbol in .got
|
|
0x68, // pushl immediate
|
|
0, 0, 0, 0, // replaced with offset into relocation table
|
|
0xe9, // jmp relative
|
|
0, 0, 0, 0 // replaced with offset to start of .plt
|
|
};
|
|
|
|
// Subsequent entries in the PLT for a shared object.
|
|
|
|
unsigned char Output_data_plt_i386::dyn_plt_entry[plt_entry_size] =
|
|
{
|
|
0xff, 0xa3, // jmp *offset(%ebx)
|
|
0, 0, 0, 0, // replaced with offset of symbol in .got
|
|
0x68, // pushl immediate
|
|
0, 0, 0, 0, // replaced with offset into relocation table
|
|
0xe9, // jmp relative
|
|
0, 0, 0, 0 // replaced with offset to start of .plt
|
|
};
|
|
|
|
// Write out the PLT. This uses the hand-coded instructions above,
|
|
// and adjusts them as needed. This is all specified by the i386 ELF
|
|
// Processor Supplement.
|
|
|
|
void
|
|
Output_data_plt_i386::do_write(Output_file* of)
|
|
{
|
|
const off_t offset = this->offset();
|
|
const 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 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();
|
|
|
|
if (parameters->options().shared())
|
|
memcpy(pov, dyn_first_plt_entry, plt_entry_size);
|
|
else
|
|
{
|
|
memcpy(pov, exec_first_plt_entry, plt_entry_size);
|
|
elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_address + 4);
|
|
elfcpp::Swap<32, false>::writeval(pov + 8, got_address + 8);
|
|
}
|
|
pov += plt_entry_size;
|
|
|
|
unsigned char* got_pov = got_view;
|
|
|
|
memset(got_pov, 0, 12);
|
|
got_pov += 12;
|
|
|
|
const int rel_size = elfcpp::Elf_sizes<32>::rel_size;
|
|
|
|
unsigned int plt_offset = plt_entry_size;
|
|
unsigned int plt_rel_offset = 0;
|
|
unsigned int got_offset = 12;
|
|
const unsigned int count = this->count_;
|
|
for (unsigned int i = 0;
|
|
i < count;
|
|
++i,
|
|
pov += plt_entry_size,
|
|
got_pov += 4,
|
|
plt_offset += plt_entry_size,
|
|
plt_rel_offset += rel_size,
|
|
got_offset += 4)
|
|
{
|
|
// Set and adjust the PLT entry itself.
|
|
|
|
if (parameters->options().shared())
|
|
{
|
|
memcpy(pov, dyn_plt_entry, plt_entry_size);
|
|
elfcpp::Swap_unaligned<32, false>::writeval(pov + 2, got_offset);
|
|
}
|
|
else
|
|
{
|
|
memcpy(pov, exec_plt_entry, plt_entry_size);
|
|
elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
|
|
(got_address
|
|
+ got_offset));
|
|
}
|
|
|
|
elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_rel_offset);
|
|
elfcpp::Swap<32, false>::writeval(pov + 12,
|
|
- (plt_offset + plt_entry_size));
|
|
|
|
// Set the entry in the GOT.
|
|
elfcpp::Swap<32, false>::writeval(got_pov, plt_address + plt_offset + 6);
|
|
}
|
|
|
|
gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
|
|
gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
|
|
|
|
of->write_output_view(offset, oview_size, oview);
|
|
of->write_output_view(got_file_offset, got_size, got_view);
|
|
}
|
|
|
|
// Create a PLT entry for a global symbol.
|
|
|
|
void
|
|
Target_i386::make_plt_entry(Symbol_table* symtab, Layout* layout, Symbol* gsym)
|
|
{
|
|
if (gsym->has_plt_offset())
|
|
return;
|
|
|
|
if (this->plt_ == NULL)
|
|
{
|
|
// Create the GOT sections first.
|
|
this->got_section(symtab, layout);
|
|
|
|
this->plt_ = new Output_data_plt_i386(layout, this->got_plt_);
|
|
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
|
|
(elfcpp::SHF_ALLOC
|
|
| elfcpp::SHF_EXECINSTR),
|
|
this->plt_);
|
|
}
|
|
|
|
this->plt_->add_entry(gsym);
|
|
}
|
|
|
|
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
|
|
|
|
void
|
|
Target_i386::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
|
|
{
|
|
if (this->tls_base_symbol_defined_)
|
|
return;
|
|
|
|
Output_segment* tls_segment = layout->tls_segment();
|
|
if (tls_segment != NULL)
|
|
{
|
|
bool is_exec = parameters->options().output_is_executable();
|
|
symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
|
|
tls_segment, 0, 0,
|
|
elfcpp::STT_TLS,
|
|
elfcpp::STB_LOCAL,
|
|
elfcpp::STV_HIDDEN, 0,
|
|
(is_exec
|
|
? Symbol::SEGMENT_END
|
|
: Symbol::SEGMENT_START),
|
|
true);
|
|
}
|
|
this->tls_base_symbol_defined_ = true;
|
|
}
|
|
|
|
// Create a GOT entry for the TLS module index.
|
|
|
|
unsigned int
|
|
Target_i386::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
|
|
Sized_relobj<32, false>* object)
|
|
{
|
|
if (this->got_mod_index_offset_ == -1U)
|
|
{
|
|
gold_assert(symtab != NULL && layout != NULL && object != NULL);
|
|
Reloc_section* rel_dyn = this->rel_dyn_section(layout);
|
|
Output_data_got<32, false>* got = this->got_section(symtab, layout);
|
|
unsigned int got_offset = got->add_constant(0);
|
|
rel_dyn->add_local(object, 0, elfcpp::R_386_TLS_DTPMOD32, got,
|
|
got_offset);
|
|
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.
|
|
|
|
tls::Tls_optimization
|
|
Target_i386::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->options().shared())
|
|
return tls::TLSOPT_NONE;
|
|
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_TLS_GD:
|
|
case elfcpp::R_386_TLS_GOTDESC:
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
// These are General-Dynamic which permits fully general TLS
|
|
// access. Since we know that we are generating an executable,
|
|
// we can convert this to Initial-Exec. If we also know that
|
|
// this is a local symbol, we can further switch to Local-Exec.
|
|
if (is_final)
|
|
return tls::TLSOPT_TO_LE;
|
|
return tls::TLSOPT_TO_IE;
|
|
|
|
case elfcpp::R_386_TLS_LDM:
|
|
// This is Local-Dynamic, which refers to a local symbol in the
|
|
// dynamic TLS block. Since we know that we generating an
|
|
// executable, we can switch to Local-Exec.
|
|
return tls::TLSOPT_TO_LE;
|
|
|
|
case elfcpp::R_386_TLS_LDO_32:
|
|
// Another type of Local-Dynamic relocation.
|
|
return tls::TLSOPT_TO_LE;
|
|
|
|
case elfcpp::R_386_TLS_IE:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
// These are Initial-Exec relocs which get the thread offset
|
|
// from the GOT. If we know that we are linking against the
|
|
// local symbol, we can switch to Local-Exec, which links the
|
|
// thread offset into the instruction.
|
|
if (is_final)
|
|
return tls::TLSOPT_TO_LE;
|
|
return tls::TLSOPT_NONE;
|
|
|
|
case elfcpp::R_386_TLS_LE:
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
// When we already have Local-Exec, there is nothing further we
|
|
// can do.
|
|
return tls::TLSOPT_NONE;
|
|
|
|
default:
|
|
gold_unreachable();
|
|
}
|
|
}
|
|
|
|
// Report an unsupported relocation against a local symbol.
|
|
|
|
void
|
|
Target_i386::Scan::unsupported_reloc_local(Sized_relobj<32, false>* object,
|
|
unsigned int r_type)
|
|
{
|
|
gold_error(_("%s: unsupported reloc %u against local symbol"),
|
|
object->name().c_str(), r_type);
|
|
}
|
|
|
|
// Scan a relocation for a local symbol.
|
|
|
|
inline void
|
|
Target_i386::Scan::local(const General_options&,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Target_i386* target,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int data_shndx,
|
|
Output_section* output_section,
|
|
const elfcpp::Rel<32, false>& reloc,
|
|
unsigned int r_type,
|
|
const elfcpp::Sym<32, false>& lsym)
|
|
{
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_NONE:
|
|
case elfcpp::R_386_GNU_VTINHERIT:
|
|
case elfcpp::R_386_GNU_VTENTRY:
|
|
break;
|
|
|
|
case elfcpp::R_386_32:
|
|
// If building a shared library (or a position-independent
|
|
// executable), we need to create a dynamic relocation for
|
|
// this location. The relocation applied at link time will
|
|
// apply the link-time value, so we flag the location with
|
|
// an R_386_RELATIVE relocation so the dynamic loader can
|
|
// relocate it easily.
|
|
if (parameters->options().output_is_position_independent())
|
|
{
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
rel_dyn->add_local_relative(object, r_sym, elfcpp::R_386_RELATIVE,
|
|
output_section, data_shndx,
|
|
reloc.get_r_offset());
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_16:
|
|
case elfcpp::R_386_8:
|
|
// If building a shared library (or a position-independent
|
|
// executable), we need to create a dynamic relocation for
|
|
// this location. Because the addend needs to remain in the
|
|
// data section, we need to be careful not to apply this
|
|
// relocation statically.
|
|
if (parameters->options().output_is_position_independent())
|
|
{
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
if (lsym.get_st_type() != elfcpp::STT_SECTION)
|
|
rel_dyn->add_local(object, r_sym, r_type, output_section,
|
|
data_shndx, reloc.get_r_offset());
|
|
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
|
|
rel_dyn->add_local_section(object, shndx,
|
|
r_type, output_section,
|
|
data_shndx, reloc.get_r_offset());
|
|
}
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_PC32:
|
|
case elfcpp::R_386_PC16:
|
|
case elfcpp::R_386_PC8:
|
|
break;
|
|
|
|
case elfcpp::R_386_PLT32:
|
|
// Since we know this is a local symbol, we can handle this as a
|
|
// PC32 reloc.
|
|
break;
|
|
|
|
case elfcpp::R_386_GOTOFF:
|
|
case elfcpp::R_386_GOTPC:
|
|
// We need a GOT section.
|
|
target->got_section(symtab, layout);
|
|
break;
|
|
|
|
case elfcpp::R_386_GOT32:
|
|
{
|
|
// The symbol requires a GOT entry.
|
|
Output_data_got<32, false>* got = target->got_section(symtab, layout);
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
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's GOT entry.
|
|
if (parameters->options().output_is_position_independent())
|
|
{
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
rel_dyn->add_local_relative(
|
|
object, r_sym, elfcpp::R_386_RELATIVE, got,
|
|
object->local_got_offset(r_sym, GOT_TYPE_STANDARD));
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
|
|
// These are relocations which should only be seen by the
|
|
// dynamic linker, and should never be seen here.
|
|
case elfcpp::R_386_COPY:
|
|
case elfcpp::R_386_GLOB_DAT:
|
|
case elfcpp::R_386_JUMP_SLOT:
|
|
case elfcpp::R_386_RELATIVE:
|
|
case elfcpp::R_386_TLS_TPOFF:
|
|
case elfcpp::R_386_TLS_DTPMOD32:
|
|
case elfcpp::R_386_TLS_DTPOFF32:
|
|
case elfcpp::R_386_TLS_TPOFF32:
|
|
case elfcpp::R_386_TLS_DESC:
|
|
gold_error(_("%s: unexpected reloc %u in object file"),
|
|
object->name().c_str(), r_type);
|
|
break;
|
|
|
|
// These are initial TLS relocs, which are expected when
|
|
// linking.
|
|
case elfcpp::R_386_TLS_GD: // Global-dynamic
|
|
case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
case elfcpp::R_386_TLS_LDM: // Local-dynamic
|
|
case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
|
|
case elfcpp::R_386_TLS_IE: // Initial-exec
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_LE: // Local-exec
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
{
|
|
bool output_is_shared = parameters->options().shared();
|
|
const tls::Tls_optimization optimized_type
|
|
= Target_i386::optimize_tls_reloc(!output_is_shared, r_type);
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_TLS_GD: // Global-dynamic
|
|
if (optimized_type == tls::TLSOPT_NONE)
|
|
{
|
|
// Create a pair of GOT entries for the module index and
|
|
// dtv-relative offset.
|
|
Output_data_got<32, false>* got
|
|
= target->got_section(symtab, layout);
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
unsigned int shndx = lsym.get_st_shndx();
|
|
bool is_ordinary;
|
|
shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
|
|
if (!is_ordinary)
|
|
object->error(_("local symbol %u has bad shndx %u"),
|
|
r_sym, shndx);
|
|
else
|
|
got->add_local_pair_with_rel(object, r_sym, shndx,
|
|
GOT_TYPE_TLS_PAIR,
|
|
target->rel_dyn_section(layout),
|
|
elfcpp::R_386_TLS_DTPMOD32, 0);
|
|
}
|
|
else if (optimized_type != tls::TLSOPT_TO_LE)
|
|
unsupported_reloc_local(object, r_type);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva)
|
|
target->define_tls_base_symbol(symtab, layout);
|
|
if (optimized_type == tls::TLSOPT_NONE)
|
|
{
|
|
// Create a double GOT entry with an R_386_TLS_DESC reloc.
|
|
Output_data_got<32, false>* got
|
|
= target->got_section(symtab, layout);
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
unsigned int shndx = lsym.get_st_shndx();
|
|
bool is_ordinary;
|
|
shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
|
|
if (!is_ordinary)
|
|
object->error(_("local symbol %u has bad shndx %u"),
|
|
r_sym, shndx);
|
|
else
|
|
got->add_local_pair_with_rel(object, r_sym, shndx,
|
|
GOT_TYPE_TLS_DESC,
|
|
target->rel_dyn_section(layout),
|
|
elfcpp::R_386_TLS_DESC, 0);
|
|
}
|
|
else if (optimized_type != tls::TLSOPT_TO_LE)
|
|
unsupported_reloc_local(object, r_type);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LDM: // 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_386_TLS_LDO_32: // Alternate local-dynamic
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE: // Initial-exec
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
layout->set_has_static_tls();
|
|
if (optimized_type == tls::TLSOPT_NONE)
|
|
{
|
|
// For the R_386_TLS_IE relocation, we need to create a
|
|
// dynamic relocation when building a shared library.
|
|
if (r_type == elfcpp::R_386_TLS_IE
|
|
&& parameters->options().shared())
|
|
{
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
unsigned int r_sym
|
|
= elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
rel_dyn->add_local_relative(object, r_sym,
|
|
elfcpp::R_386_RELATIVE,
|
|
output_section, data_shndx,
|
|
reloc.get_r_offset());
|
|
}
|
|
// Create a GOT entry for the tp-relative offset.
|
|
Output_data_got<32, false>* got
|
|
= target->got_section(symtab, layout);
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
|
|
? elfcpp::R_386_TLS_TPOFF32
|
|
: elfcpp::R_386_TLS_TPOFF);
|
|
unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
|
|
? GOT_TYPE_TLS_OFFSET
|
|
: GOT_TYPE_TLS_NOFFSET);
|
|
got->add_local_with_rel(object, r_sym, got_type,
|
|
target->rel_dyn_section(layout),
|
|
dyn_r_type);
|
|
}
|
|
else if (optimized_type != tls::TLSOPT_TO_LE)
|
|
unsupported_reloc_local(object, r_type);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LE: // Local-exec
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
layout->set_has_static_tls();
|
|
if (output_is_shared)
|
|
{
|
|
// We need to create a dynamic relocation.
|
|
gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(reloc.get_r_info());
|
|
unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
|
|
? elfcpp::R_386_TLS_TPOFF32
|
|
: elfcpp::R_386_TLS_TPOFF);
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
rel_dyn->add_local(object, r_sym, dyn_r_type, output_section,
|
|
data_shndx, reloc.get_r_offset());
|
|
}
|
|
break;
|
|
|
|
default:
|
|
gold_unreachable();
|
|
}
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_32PLT:
|
|
case elfcpp::R_386_TLS_GD_32:
|
|
case elfcpp::R_386_TLS_GD_PUSH:
|
|
case elfcpp::R_386_TLS_GD_CALL:
|
|
case elfcpp::R_386_TLS_GD_POP:
|
|
case elfcpp::R_386_TLS_LDM_32:
|
|
case elfcpp::R_386_TLS_LDM_PUSH:
|
|
case elfcpp::R_386_TLS_LDM_CALL:
|
|
case elfcpp::R_386_TLS_LDM_POP:
|
|
case elfcpp::R_386_USED_BY_INTEL_200:
|
|
default:
|
|
unsupported_reloc_local(object, r_type);
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Report an unsupported relocation against a global symbol.
|
|
|
|
void
|
|
Target_i386::Scan::unsupported_reloc_global(Sized_relobj<32, false>* object,
|
|
unsigned int r_type,
|
|
Symbol* gsym)
|
|
{
|
|
gold_error(_("%s: unsupported reloc %u against global symbol %s"),
|
|
object->name().c_str(), r_type, gsym->demangled_name().c_str());
|
|
}
|
|
|
|
// Scan a relocation for a global symbol.
|
|
|
|
inline void
|
|
Target_i386::Scan::global(const General_options&,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Target_i386* target,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int data_shndx,
|
|
Output_section* output_section,
|
|
const elfcpp::Rel<32, false>& reloc,
|
|
unsigned int r_type,
|
|
Symbol* gsym)
|
|
{
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_NONE:
|
|
case elfcpp::R_386_GNU_VTINHERIT:
|
|
case elfcpp::R_386_GNU_VTENTRY:
|
|
break;
|
|
|
|
case elfcpp::R_386_32:
|
|
case elfcpp::R_386_16:
|
|
case elfcpp::R_386_8:
|
|
{
|
|
// Make a PLT entry if necessary.
|
|
if (gsym->needs_plt_entry())
|
|
{
|
|
target->make_plt_entry(symtab, layout, gsym);
|
|
// Since this is not a PC-relative relocation, we may be
|
|
// taking the address of a function. In that case we need to
|
|
// set the entry in the dynamic symbol table to the address of
|
|
// the PLT entry.
|
|
if (gsym->is_from_dynobj() && !parameters->options().shared())
|
|
gsym->set_needs_dynsym_value();
|
|
}
|
|
// Make a dynamic relocation if necessary.
|
|
if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
|
|
{
|
|
if (target->may_need_copy_reloc(gsym))
|
|
{
|
|
target->copy_reloc(symtab, layout, object,
|
|
data_shndx, output_section, gsym, reloc);
|
|
}
|
|
else if (r_type == elfcpp::R_386_32
|
|
&& gsym->can_use_relative_reloc(false))
|
|
{
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
|
|
output_section, object,
|
|
data_shndx, reloc.get_r_offset());
|
|
}
|
|
else
|
|
{
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
rel_dyn->add_global(gsym, r_type, output_section, object,
|
|
data_shndx, reloc.get_r_offset());
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_PC32:
|
|
case elfcpp::R_386_PC16:
|
|
case elfcpp::R_386_PC8:
|
|
{
|
|
// Make a PLT entry if necessary.
|
|
if (gsym->needs_plt_entry())
|
|
{
|
|
// These relocations are used for function calls only in
|
|
// non-PIC code. For a 32-bit relocation in a shared library,
|
|
// we'll need a text relocation anyway, so we can skip the
|
|
// PLT entry and let the dynamic linker bind the call directly
|
|
// to the target. For smaller relocations, we should use a
|
|
// PLT entry to ensure that the call can reach.
|
|
if (!parameters->options().shared()
|
|
|| r_type != elfcpp::R_386_PC32)
|
|
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 (target->may_need_copy_reloc(gsym))
|
|
{
|
|
target->copy_reloc(symtab, layout, object,
|
|
data_shndx, output_section, gsym, reloc);
|
|
}
|
|
else
|
|
{
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
rel_dyn->add_global(gsym, r_type, output_section, object,
|
|
data_shndx, reloc.get_r_offset());
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_GOT32:
|
|
{
|
|
// The symbol requires a GOT entry.
|
|
Output_data_got<32, false>* got = target->got_section(symtab, layout);
|
|
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
|
|
// GOT entry with a dynamic relocation.
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
if (gsym->is_from_dynobj()
|
|
|| gsym->is_undefined()
|
|
|| gsym->is_preemptible())
|
|
got->add_global_with_rel(gsym, GOT_TYPE_STANDARD,
|
|
rel_dyn, elfcpp::R_386_GLOB_DAT);
|
|
else
|
|
{
|
|
if (got->add_global(gsym, GOT_TYPE_STANDARD))
|
|
rel_dyn->add_global_relative(
|
|
gsym, elfcpp::R_386_RELATIVE, got,
|
|
gsym->got_offset(GOT_TYPE_STANDARD));
|
|
}
|
|
}
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_PLT32:
|
|
// If the symbol is fully resolved, this is just a PC32 reloc.
|
|
// Otherwise we need a PLT entry.
|
|
if (gsym->final_value_is_known())
|
|
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_386_GOTOFF:
|
|
case elfcpp::R_386_GOTPC:
|
|
// We need a GOT section.
|
|
target->got_section(symtab, layout);
|
|
break;
|
|
|
|
// These are relocations which should only be seen by the
|
|
// dynamic linker, and should never be seen here.
|
|
case elfcpp::R_386_COPY:
|
|
case elfcpp::R_386_GLOB_DAT:
|
|
case elfcpp::R_386_JUMP_SLOT:
|
|
case elfcpp::R_386_RELATIVE:
|
|
case elfcpp::R_386_TLS_TPOFF:
|
|
case elfcpp::R_386_TLS_DTPMOD32:
|
|
case elfcpp::R_386_TLS_DTPOFF32:
|
|
case elfcpp::R_386_TLS_TPOFF32:
|
|
case elfcpp::R_386_TLS_DESC:
|
|
gold_error(_("%s: unexpected reloc %u in object file"),
|
|
object->name().c_str(), r_type);
|
|
break;
|
|
|
|
// These are initial tls relocs, which are expected when
|
|
// linking.
|
|
case elfcpp::R_386_TLS_GD: // Global-dynamic
|
|
case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
case elfcpp::R_386_TLS_LDM: // Local-dynamic
|
|
case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
|
|
case elfcpp::R_386_TLS_IE: // Initial-exec
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_LE: // Local-exec
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
{
|
|
const bool is_final = gsym->final_value_is_known();
|
|
const tls::Tls_optimization optimized_type
|
|
= Target_i386::optimize_tls_reloc(is_final, r_type);
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_TLS_GD: // Global-dynamic
|
|
if (optimized_type == tls::TLSOPT_NONE)
|
|
{
|
|
// Create a pair of GOT entries for the module index and
|
|
// dtv-relative offset.
|
|
Output_data_got<32, false>* got
|
|
= target->got_section(symtab, layout);
|
|
got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_PAIR,
|
|
target->rel_dyn_section(layout),
|
|
elfcpp::R_386_TLS_DTPMOD32,
|
|
elfcpp::R_386_TLS_DTPOFF32);
|
|
}
|
|
else if (optimized_type == tls::TLSOPT_TO_IE)
|
|
{
|
|
// Create a GOT entry for the tp-relative offset.
|
|
Output_data_got<32, false>* got
|
|
= target->got_section(symtab, layout);
|
|
got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
|
|
target->rel_dyn_section(layout),
|
|
elfcpp::R_386_TLS_TPOFF);
|
|
}
|
|
else if (optimized_type != tls::TLSOPT_TO_LE)
|
|
unsupported_reloc_global(object, r_type, gsym);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (~oliva url)
|
|
target->define_tls_base_symbol(symtab, layout);
|
|
if (optimized_type == tls::TLSOPT_NONE)
|
|
{
|
|
// Create a double GOT entry with an R_386_TLS_DESC reloc.
|
|
Output_data_got<32, false>* got
|
|
= target->got_section(symtab, layout);
|
|
got->add_global_pair_with_rel(gsym, GOT_TYPE_TLS_DESC,
|
|
target->rel_dyn_section(layout),
|
|
elfcpp::R_386_TLS_DESC, 0);
|
|
}
|
|
else if (optimized_type == tls::TLSOPT_TO_IE)
|
|
{
|
|
// Create a GOT entry for the tp-relative offset.
|
|
Output_data_got<32, false>* got
|
|
= target->got_section(symtab, layout);
|
|
got->add_global_with_rel(gsym, GOT_TYPE_TLS_NOFFSET,
|
|
target->rel_dyn_section(layout),
|
|
elfcpp::R_386_TLS_TPOFF);
|
|
}
|
|
else if (optimized_type != tls::TLSOPT_TO_LE)
|
|
unsupported_reloc_global(object, r_type, gsym);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LDM: // 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_386_TLS_LDO_32: // Alternate local-dynamic
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE: // Initial-exec
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
layout->set_has_static_tls();
|
|
if (optimized_type == tls::TLSOPT_NONE)
|
|
{
|
|
// For the R_386_TLS_IE relocation, we need to create a
|
|
// dynamic relocation when building a shared library.
|
|
if (r_type == elfcpp::R_386_TLS_IE
|
|
&& parameters->options().shared())
|
|
{
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
rel_dyn->add_global_relative(gsym, elfcpp::R_386_RELATIVE,
|
|
output_section, object,
|
|
data_shndx,
|
|
reloc.get_r_offset());
|
|
}
|
|
// Create a GOT entry for the tp-relative offset.
|
|
Output_data_got<32, false>* got
|
|
= target->got_section(symtab, layout);
|
|
unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_IE_32
|
|
? elfcpp::R_386_TLS_TPOFF32
|
|
: elfcpp::R_386_TLS_TPOFF);
|
|
unsigned int got_type = (r_type == elfcpp::R_386_TLS_IE_32
|
|
? GOT_TYPE_TLS_OFFSET
|
|
: GOT_TYPE_TLS_NOFFSET);
|
|
got->add_global_with_rel(gsym, got_type,
|
|
target->rel_dyn_section(layout),
|
|
dyn_r_type);
|
|
}
|
|
else if (optimized_type != tls::TLSOPT_TO_LE)
|
|
unsupported_reloc_global(object, r_type, gsym);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LE: // Local-exec
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
layout->set_has_static_tls();
|
|
if (parameters->options().shared())
|
|
{
|
|
// We need to create a dynamic relocation.
|
|
unsigned int dyn_r_type = (r_type == elfcpp::R_386_TLS_LE_32
|
|
? elfcpp::R_386_TLS_TPOFF32
|
|
: elfcpp::R_386_TLS_TPOFF);
|
|
Reloc_section* rel_dyn = target->rel_dyn_section(layout);
|
|
rel_dyn->add_global(gsym, dyn_r_type, output_section, object,
|
|
data_shndx, reloc.get_r_offset());
|
|
}
|
|
break;
|
|
|
|
default:
|
|
gold_unreachable();
|
|
}
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_32PLT:
|
|
case elfcpp::R_386_TLS_GD_32:
|
|
case elfcpp::R_386_TLS_GD_PUSH:
|
|
case elfcpp::R_386_TLS_GD_CALL:
|
|
case elfcpp::R_386_TLS_GD_POP:
|
|
case elfcpp::R_386_TLS_LDM_32:
|
|
case elfcpp::R_386_TLS_LDM_PUSH:
|
|
case elfcpp::R_386_TLS_LDM_CALL:
|
|
case elfcpp::R_386_TLS_LDM_POP:
|
|
case elfcpp::R_386_USED_BY_INTEL_200:
|
|
default:
|
|
unsupported_reloc_global(object, r_type, gsym);
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Process relocations for gc.
|
|
|
|
void
|
|
Target_i386::gc_process_relocs(const General_options& options,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int data_shndx,
|
|
unsigned int,
|
|
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)
|
|
{
|
|
gold::gc_process_relocs<32, false, Target_i386, elfcpp::SHT_REL,
|
|
Target_i386::Scan>(
|
|
options,
|
|
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_i386::scan_relocs(const General_options& options,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int data_shndx,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
Output_section* output_section,
|
|
bool needs_special_offset_handling,
|
|
size_t local_symbol_count,
|
|
const unsigned char* plocal_symbols)
|
|
{
|
|
if (sh_type == elfcpp::SHT_RELA)
|
|
{
|
|
gold_error(_("%s: unsupported RELA reloc section"),
|
|
object->name().c_str());
|
|
return;
|
|
}
|
|
|
|
gold::scan_relocs<32, false, Target_i386, elfcpp::SHT_REL,
|
|
Target_i386::Scan>(
|
|
options,
|
|
symtab,
|
|
layout,
|
|
this,
|
|
object,
|
|
data_shndx,
|
|
prelocs,
|
|
reloc_count,
|
|
output_section,
|
|
needs_special_offset_handling,
|
|
local_symbol_count,
|
|
plocal_symbols);
|
|
}
|
|
|
|
// Finalize the sections.
|
|
|
|
void
|
|
Target_i386::do_finalize_sections(Layout* layout)
|
|
{
|
|
// Fill in some more dynamic tags.
|
|
Output_data_dynamic* const odyn = layout->dynamic_data();
|
|
if (odyn != NULL)
|
|
{
|
|
if (this->got_plt_ != NULL)
|
|
odyn->add_section_address(elfcpp::DT_PLTGOT, this->got_plt_);
|
|
|
|
if (this->plt_ != NULL)
|
|
{
|
|
const Output_data* od = this->plt_->rel_plt();
|
|
odyn->add_section_size(elfcpp::DT_PLTRELSZ, od);
|
|
odyn->add_section_address(elfcpp::DT_JMPREL, od);
|
|
odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_REL);
|
|
}
|
|
|
|
if (this->rel_dyn_ != NULL)
|
|
{
|
|
const Output_data* od = this->rel_dyn_;
|
|
odyn->add_section_address(elfcpp::DT_REL, od);
|
|
odyn->add_section_size(elfcpp::DT_RELSZ, od);
|
|
odyn->add_constant(elfcpp::DT_RELENT,
|
|
elfcpp::Elf_sizes<32>::rel_size);
|
|
}
|
|
|
|
if (!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.
|
|
odyn->add_constant(elfcpp::DT_DEBUG, 0);
|
|
}
|
|
}
|
|
|
|
// Emit any relocs we saved in an attempt to avoid generating COPY
|
|
// relocs.
|
|
if (this->copy_relocs_.any_saved_relocs())
|
|
this->copy_relocs_.emit(this->rel_dyn_section(layout));
|
|
}
|
|
|
|
// Return whether a direct absolute static relocation needs to be applied.
|
|
// In cases where Scan::local() or Scan::global() has created
|
|
// a dynamic relocation other than R_386_RELATIVE, the addend
|
|
// of the relocation is carried in the data, and we must not
|
|
// apply the static relocation.
|
|
|
|
inline bool
|
|
Target_i386::Relocate::should_apply_static_reloc(const Sized_symbol<32>* gsym,
|
|
int ref_flags,
|
|
bool is_32bit,
|
|
Output_section* output_section)
|
|
{
|
|
// If the output section is not allocated, then we didn't call
|
|
// scan_relocs, we didn't create a dynamic reloc, and we must apply
|
|
// the reloc here.
|
|
if ((output_section->flags() & elfcpp::SHF_ALLOC) == 0)
|
|
return true;
|
|
|
|
// For local symbols, we will have created a non-RELATIVE dynamic
|
|
// relocation only if (a) the output is position independent,
|
|
// (b) the relocation is absolute (not pc- or segment-relative), and
|
|
// (c) the relocation is not 32 bits wide.
|
|
if (gsym == NULL)
|
|
return !(parameters->options().output_is_position_independent()
|
|
&& (ref_flags & Symbol::ABSOLUTE_REF)
|
|
&& !is_32bit);
|
|
|
|
// For global symbols, we use the same helper routines used in the
|
|
// scan pass. If we did not create a dynamic relocation, or if we
|
|
// created a RELATIVE dynamic relocation, we should apply the static
|
|
// relocation.
|
|
bool has_dyn = gsym->needs_dynamic_reloc(ref_flags);
|
|
bool is_rel = (ref_flags & Symbol::ABSOLUTE_REF)
|
|
&& gsym->can_use_relative_reloc(ref_flags
|
|
& Symbol::FUNCTION_CALL);
|
|
return !has_dyn || is_rel;
|
|
}
|
|
|
|
// Perform a relocation.
|
|
|
|
inline bool
|
|
Target_i386::Relocate::relocate(const Relocate_info<32, false>* relinfo,
|
|
Target_i386* target,
|
|
Output_section *output_section,
|
|
size_t relnum,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int r_type,
|
|
const Sized_symbol<32>* gsym,
|
|
const Symbol_value<32>* psymval,
|
|
unsigned char* view,
|
|
elfcpp::Elf_types<32>::Elf_Addr address,
|
|
section_size_type view_size)
|
|
{
|
|
if (this->skip_call_tls_get_addr_)
|
|
{
|
|
if ((r_type != elfcpp::R_386_PLT32
|
|
&& r_type != elfcpp::R_386_PC32)
|
|
|| gsym == NULL
|
|
|| strcmp(gsym->name(), "___tls_get_addr") != 0)
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
|
|
_("missing expected TLS relocation"));
|
|
else
|
|
{
|
|
this->skip_call_tls_get_addr_ = false;
|
|
return false;
|
|
}
|
|
}
|
|
|
|
// Pick the value to use for symbols defined in shared objects.
|
|
Symbol_value<32> symval;
|
|
if (gsym != NULL
|
|
&& gsym->use_plt_offset(r_type == elfcpp::R_386_PC8
|
|
|| r_type == elfcpp::R_386_PC16
|
|
|| r_type == elfcpp::R_386_PC32))
|
|
{
|
|
symval.set_output_value(target->plt_section()->address()
|
|
+ gsym->plt_offset());
|
|
psymval = &symval;
|
|
}
|
|
|
|
const Sized_relobj<32, false>* object = relinfo->object;
|
|
|
|
// 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)
|
|
{
|
|
case elfcpp::R_386_GOT32:
|
|
if (gsym != NULL)
|
|
{
|
|
gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
|
|
got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
|
|
- target->got_size());
|
|
}
|
|
else
|
|
{
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
|
|
gold_assert(object->local_has_got_offset(r_sym, GOT_TYPE_STANDARD));
|
|
got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
|
|
- target->got_size());
|
|
}
|
|
have_got_offset = true;
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_NONE:
|
|
case elfcpp::R_386_GNU_VTINHERIT:
|
|
case elfcpp::R_386_GNU_VTENTRY:
|
|
break;
|
|
|
|
case elfcpp::R_386_32:
|
|
if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, true,
|
|
output_section))
|
|
Relocate_functions<32, false>::rel32(view, object, psymval);
|
|
break;
|
|
|
|
case elfcpp::R_386_PC32:
|
|
{
|
|
int ref_flags = Symbol::NON_PIC_REF;
|
|
if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
|
|
ref_flags |= Symbol::FUNCTION_CALL;
|
|
if (should_apply_static_reloc(gsym, ref_flags, true, output_section))
|
|
Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_16:
|
|
if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
|
|
output_section))
|
|
Relocate_functions<32, false>::rel16(view, object, psymval);
|
|
break;
|
|
|
|
case elfcpp::R_386_PC16:
|
|
{
|
|
int ref_flags = Symbol::NON_PIC_REF;
|
|
if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
|
|
ref_flags |= Symbol::FUNCTION_CALL;
|
|
if (should_apply_static_reloc(gsym, ref_flags, false, output_section))
|
|
Relocate_functions<32, false>::pcrel16(view, object, psymval, address);
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_8:
|
|
if (should_apply_static_reloc(gsym, Symbol::ABSOLUTE_REF, false,
|
|
output_section))
|
|
Relocate_functions<32, false>::rel8(view, object, psymval);
|
|
break;
|
|
|
|
case elfcpp::R_386_PC8:
|
|
{
|
|
int ref_flags = Symbol::NON_PIC_REF;
|
|
if (gsym != NULL && gsym->type() == elfcpp::STT_FUNC)
|
|
ref_flags |= Symbol::FUNCTION_CALL;
|
|
if (should_apply_static_reloc(gsym, ref_flags, false,
|
|
output_section))
|
|
Relocate_functions<32, false>::pcrel8(view, object, psymval, address);
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_PLT32:
|
|
gold_assert(gsym == NULL
|
|
|| gsym->has_plt_offset()
|
|
|| gsym->final_value_is_known()
|
|
|| (gsym->is_defined()
|
|
&& !gsym->is_from_dynobj()
|
|
&& !gsym->is_preemptible()));
|
|
Relocate_functions<32, false>::pcrel32(view, object, psymval, address);
|
|
break;
|
|
|
|
case elfcpp::R_386_GOT32:
|
|
gold_assert(have_got_offset);
|
|
Relocate_functions<32, false>::rel32(view, got_offset);
|
|
break;
|
|
|
|
case elfcpp::R_386_GOTOFF:
|
|
{
|
|
elfcpp::Elf_types<32>::Elf_Addr value;
|
|
value = (psymval->value(object, 0)
|
|
- target->got_plt_section()->address());
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_GOTPC:
|
|
{
|
|
elfcpp::Elf_types<32>::Elf_Addr value;
|
|
value = target->got_plt_section()->address();
|
|
Relocate_functions<32, false>::pcrel32(view, value, address);
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_COPY:
|
|
case elfcpp::R_386_GLOB_DAT:
|
|
case elfcpp::R_386_JUMP_SLOT:
|
|
case elfcpp::R_386_RELATIVE:
|
|
// These are outstanding tls relocs, which are unexpected when
|
|
// linking.
|
|
case elfcpp::R_386_TLS_TPOFF:
|
|
case elfcpp::R_386_TLS_DTPMOD32:
|
|
case elfcpp::R_386_TLS_DTPOFF32:
|
|
case elfcpp::R_386_TLS_TPOFF32:
|
|
case elfcpp::R_386_TLS_DESC:
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
|
|
_("unexpected reloc %u in object file"),
|
|
r_type);
|
|
break;
|
|
|
|
// These are initial tls relocs, which are expected when
|
|
// linking.
|
|
case elfcpp::R_386_TLS_GD: // Global-dynamic
|
|
case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
case elfcpp::R_386_TLS_LDM: // Local-dynamic
|
|
case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
|
|
case elfcpp::R_386_TLS_IE: // Initial-exec
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_LE: // Local-exec
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
this->relocate_tls(relinfo, target, relnum, rel, r_type, gsym, psymval,
|
|
view, address, view_size);
|
|
break;
|
|
|
|
case elfcpp::R_386_32PLT:
|
|
case elfcpp::R_386_TLS_GD_32:
|
|
case elfcpp::R_386_TLS_GD_PUSH:
|
|
case elfcpp::R_386_TLS_GD_CALL:
|
|
case elfcpp::R_386_TLS_GD_POP:
|
|
case elfcpp::R_386_TLS_LDM_32:
|
|
case elfcpp::R_386_TLS_LDM_PUSH:
|
|
case elfcpp::R_386_TLS_LDM_CALL:
|
|
case elfcpp::R_386_TLS_LDM_POP:
|
|
case elfcpp::R_386_USED_BY_INTEL_200:
|
|
default:
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
|
|
_("unsupported reloc %u"),
|
|
r_type);
|
|
break;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
// Perform a TLS relocation.
|
|
|
|
inline void
|
|
Target_i386::Relocate::relocate_tls(const Relocate_info<32, false>* relinfo,
|
|
Target_i386* target,
|
|
size_t relnum,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int r_type,
|
|
const Sized_symbol<32>* gsym,
|
|
const Symbol_value<32>* psymval,
|
|
unsigned char* view,
|
|
elfcpp::Elf_types<32>::Elf_Addr,
|
|
section_size_type view_size)
|
|
{
|
|
Output_segment* tls_segment = relinfo->layout->tls_segment();
|
|
|
|
const Sized_relobj<32, false>* object = relinfo->object;
|
|
|
|
elfcpp::Elf_types<32>::Elf_Addr value = psymval->value(object, 0);
|
|
|
|
const bool is_final =
|
|
(gsym == NULL
|
|
? !parameters->options().output_is_position_independent()
|
|
: gsym->final_value_is_known());
|
|
const tls::Tls_optimization optimized_type
|
|
= Target_i386::optimize_tls_reloc(is_final, r_type);
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_TLS_GD: // Global-dynamic
|
|
if (optimized_type == tls::TLSOPT_TO_LE)
|
|
{
|
|
gold_assert(tls_segment != NULL);
|
|
this->tls_gd_to_le(relinfo, relnum, tls_segment,
|
|
rel, r_type, value, view,
|
|
view_size);
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
|
|
? GOT_TYPE_TLS_NOFFSET
|
|
: 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<32>(rel.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);
|
|
this->tls_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
|
|
got_offset, view, view_size);
|
|
break;
|
|
}
|
|
else if (optimized_type == tls::TLSOPT_NONE)
|
|
{
|
|
// Relocate the field with the offset of the pair of GOT
|
|
// entries.
|
|
Relocate_functions<32, false>::rel32(view, got_offset);
|
|
break;
|
|
}
|
|
}
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
|
|
_("unsupported reloc %u"),
|
|
r_type);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
|
|
if (optimized_type == tls::TLSOPT_TO_LE)
|
|
{
|
|
gold_assert(tls_segment != NULL);
|
|
this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
|
|
rel, r_type, value, view,
|
|
view_size);
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
|
|
? GOT_TYPE_TLS_NOFFSET
|
|
: 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<32>(rel.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);
|
|
this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment, rel, r_type,
|
|
got_offset, view, view_size);
|
|
break;
|
|
}
|
|
else if (optimized_type == tls::TLSOPT_NONE)
|
|
{
|
|
if (r_type == elfcpp::R_386_TLS_GOTDESC)
|
|
{
|
|
// Relocate the field with the offset of the pair of GOT
|
|
// entries.
|
|
Relocate_functions<32, false>::rel32(view, got_offset);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
|
|
_("unsupported reloc %u"),
|
|
r_type);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LDM: // Local-dynamic
|
|
if (this->local_dynamic_type_ == LOCAL_DYNAMIC_SUN)
|
|
{
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
|
|
_("both SUN and GNU model "
|
|
"TLS relocations"));
|
|
break;
|
|
}
|
|
this->local_dynamic_type_ = LOCAL_DYNAMIC_GNU;
|
|
if (optimized_type == tls::TLSOPT_TO_LE)
|
|
{
|
|
gold_assert(tls_segment != NULL);
|
|
this->tls_ld_to_le(relinfo, relnum, tls_segment, rel, 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());
|
|
Relocate_functions<32, false>::rel32(view, got_offset);
|
|
break;
|
|
}
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
|
|
_("unsupported reloc %u"),
|
|
r_type);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
|
|
// This reloc can appear in debugging sections, in which case we
|
|
// won't see the TLS_LDM reloc. The local_dynamic_type field
|
|
// tells us this.
|
|
if (optimized_type == tls::TLSOPT_TO_LE
|
|
&& this->local_dynamic_type_ != LOCAL_DYNAMIC_NONE)
|
|
{
|
|
gold_assert(tls_segment != NULL);
|
|
value -= tls_segment->memsz();
|
|
}
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_IE: // Initial-exec
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
if (optimized_type == tls::TLSOPT_TO_LE)
|
|
{
|
|
gold_assert(tls_segment != NULL);
|
|
Target_i386::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
|
|
rel, 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_type = (r_type == elfcpp::R_386_TLS_IE_32
|
|
? GOT_TYPE_TLS_OFFSET
|
|
: GOT_TYPE_TLS_NOFFSET);
|
|
unsigned int got_offset;
|
|
if (gsym != NULL)
|
|
{
|
|
gold_assert(gsym->has_got_offset(got_type));
|
|
got_offset = gsym->got_offset(got_type);
|
|
}
|
|
else
|
|
{
|
|
unsigned int r_sym = elfcpp::elf_r_sym<32>(rel.get_r_info());
|
|
gold_assert(object->local_has_got_offset(r_sym, got_type));
|
|
got_offset = object->local_got_offset(r_sym, got_type);
|
|
}
|
|
// For the R_386_TLS_IE relocation, we need to apply the
|
|
// absolute address of the GOT entry.
|
|
if (r_type == elfcpp::R_386_TLS_IE)
|
|
got_offset += target->got_plt_section()->address();
|
|
// All GOT offsets are relative to the end of the GOT.
|
|
got_offset -= target->got_size();
|
|
Relocate_functions<32, false>::rel32(view, got_offset);
|
|
break;
|
|
}
|
|
gold_error_at_location(relinfo, relnum, rel.get_r_offset(),
|
|
_("unsupported reloc %u"),
|
|
r_type);
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LE: // Local-exec
|
|
// If we're creating a shared library, a dynamic relocation will
|
|
// have been created for this location, so do not apply it now.
|
|
if (!parameters->options().shared())
|
|
{
|
|
gold_assert(tls_segment != NULL);
|
|
value -= tls_segment->memsz();
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
}
|
|
break;
|
|
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
// If we're creating a shared library, a dynamic relocation will
|
|
// have been created for this location, so do not apply it now.
|
|
if (!parameters->options().shared())
|
|
{
|
|
gold_assert(tls_segment != NULL);
|
|
value = tls_segment->memsz() - value;
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Do a relocation in which we convert a TLS General-Dynamic to a
|
|
// Local-Exec.
|
|
|
|
inline void
|
|
Target_i386::Relocate::tls_gd_to_le(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
Output_segment* tls_segment,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
section_size_type view_size)
|
|
{
|
|
// leal foo(,%reg,1),%eax; call ___tls_get_addr
|
|
// ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
|
|
// leal foo(%reg),%eax; call ___tls_get_addr
|
|
// ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
|
|
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
|
|
|
|
unsigned char op1 = view[-1];
|
|
unsigned char op2 = view[-2];
|
|
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
op2 == 0x8d || op2 == 0x04);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
|
|
|
|
int roff = 5;
|
|
|
|
if (op2 == 0x04)
|
|
{
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
|
|
memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
|
|
}
|
|
else
|
|
{
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
(op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
|
|
if (rel.get_r_offset() + 9 < view_size
|
|
&& view[9] == 0x90)
|
|
{
|
|
// There is a trailing nop. Use the size byte subl.
|
|
memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
|
|
roff = 6;
|
|
}
|
|
else
|
|
{
|
|
// Use the five byte subl.
|
|
memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
|
|
}
|
|
}
|
|
|
|
value = tls_segment->memsz() - value;
|
|
Relocate_functions<32, false>::rel32(view + roff, value);
|
|
|
|
// The next reloc should be a PLT32 reloc against __tls_get_addr.
|
|
// We can skip it.
|
|
this->skip_call_tls_get_addr_ = true;
|
|
}
|
|
|
|
// Do a relocation in which we convert a TLS General-Dynamic to an
|
|
// Initial-Exec.
|
|
|
|
inline void
|
|
Target_i386::Relocate::tls_gd_to_ie(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
Output_segment*,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
section_size_type view_size)
|
|
{
|
|
// leal foo(,%ebx,1),%eax; call ___tls_get_addr
|
|
// ==> movl %gs:0,%eax; addl foo@gotntpoff(%ebx),%eax
|
|
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
|
|
|
|
unsigned char op1 = view[-1];
|
|
unsigned char op2 = view[-2];
|
|
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
op2 == 0x8d || op2 == 0x04);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
|
|
|
|
int roff = 5;
|
|
|
|
// FIXME: For now, support only the first (SIB) form.
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(), op2 == 0x04);
|
|
|
|
if (op2 == 0x04)
|
|
{
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -3);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[-3] == 0x8d);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
((op1 & 0xc7) == 0x05 && op1 != (4 << 3)));
|
|
memcpy(view - 3, "\x65\xa1\0\0\0\0\x03\x83\0\0\0", 12);
|
|
}
|
|
else
|
|
{
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
(op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
|
|
if (rel.get_r_offset() + 9 < view_size
|
|
&& view[9] == 0x90)
|
|
{
|
|
// FIXME: This is not the right instruction sequence.
|
|
// There is a trailing nop. Use the size byte subl.
|
|
memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
|
|
roff = 6;
|
|
}
|
|
else
|
|
{
|
|
// FIXME: This is not the right instruction sequence.
|
|
// Use the five byte subl.
|
|
memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
|
|
}
|
|
}
|
|
|
|
Relocate_functions<32, false>::rel32(view + roff, value);
|
|
|
|
// The next reloc should be a PLT32 reloc against __tls_get_addr.
|
|
// We can skip it.
|
|
this->skip_call_tls_get_addr_ = true;
|
|
}
|
|
|
|
// Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
|
|
// General-Dynamic to a Local-Exec.
|
|
|
|
inline void
|
|
Target_i386::Relocate::tls_desc_gd_to_le(
|
|
const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
Output_segment* tls_segment,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int r_type,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
section_size_type view_size)
|
|
{
|
|
if (r_type == elfcpp::R_386_TLS_GOTDESC)
|
|
{
|
|
// leal foo@TLSDESC(%ebx), %eax
|
|
// ==> leal foo@NTPOFF, %eax
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
view[-2] == 0x8d && view[-1] == 0x83);
|
|
view[-1] = 0x05;
|
|
value -= tls_segment->memsz();
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
}
|
|
else
|
|
{
|
|
// call *foo@TLSCALL(%eax)
|
|
// ==> nop; nop
|
|
gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
view[0] == 0xff && view[1] == 0x10);
|
|
view[0] = 0x66;
|
|
view[1] = 0x90;
|
|
}
|
|
}
|
|
|
|
// Do a relocation in which we convert a TLS_GOTDESC or TLS_DESC_CALL
|
|
// General-Dynamic to an Initial-Exec.
|
|
|
|
inline void
|
|
Target_i386::Relocate::tls_desc_gd_to_ie(
|
|
const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
Output_segment*,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int r_type,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
section_size_type view_size)
|
|
{
|
|
if (r_type == elfcpp::R_386_TLS_GOTDESC)
|
|
{
|
|
// leal foo@TLSDESC(%ebx), %eax
|
|
// ==> movl foo@GOTNTPOFF(%ebx), %eax
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
view[-2] == 0x8d && view[-1] == 0x83);
|
|
view[-2] = 0x8b;
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
}
|
|
else
|
|
{
|
|
// call *foo@TLSCALL(%eax)
|
|
// ==> nop; nop
|
|
gold_assert(r_type == elfcpp::R_386_TLS_DESC_CALL);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 2);
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
view[0] == 0xff && view[1] == 0x10);
|
|
view[0] = 0x66;
|
|
view[1] = 0x90;
|
|
}
|
|
}
|
|
|
|
// Do a relocation in which we convert a TLS Local-Dynamic to a
|
|
// Local-Exec.
|
|
|
|
inline void
|
|
Target_i386::Relocate::tls_ld_to_le(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
Output_segment*,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int,
|
|
elfcpp::Elf_types<32>::Elf_Addr,
|
|
unsigned char* view,
|
|
section_size_type view_size)
|
|
{
|
|
// leal foo(%reg), %eax; call ___tls_get_addr
|
|
// ==> movl %gs:0,%eax; nop; leal 0(%esi,1),%esi
|
|
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 9);
|
|
|
|
// FIXME: Does this test really always pass?
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
view[-2] == 0x8d && view[-1] == 0x83);
|
|
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(), view[4] == 0xe8);
|
|
|
|
memcpy(view - 2, "\x65\xa1\0\0\0\0\x90\x8d\x74\x26\0", 11);
|
|
|
|
// 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 Initial-Exec to a
|
|
// Local-Exec.
|
|
|
|
inline void
|
|
Target_i386::Relocate::tls_ie_to_le(const Relocate_info<32, false>* relinfo,
|
|
size_t relnum,
|
|
Output_segment* tls_segment,
|
|
const elfcpp::Rel<32, false>& rel,
|
|
unsigned int r_type,
|
|
elfcpp::Elf_types<32>::Elf_Addr value,
|
|
unsigned char* view,
|
|
section_size_type view_size)
|
|
{
|
|
// We have to actually change the instructions, which means that we
|
|
// need to examine the opcodes to figure out which instruction we
|
|
// are looking at.
|
|
if (r_type == elfcpp::R_386_TLS_IE)
|
|
{
|
|
// movl %gs:XX,%eax ==> movl $YY,%eax
|
|
// movl %gs:XX,%reg ==> movl $YY,%reg
|
|
// addl %gs:XX,%reg ==> addl $YY,%reg
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -1);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
|
|
|
|
unsigned char op1 = view[-1];
|
|
if (op1 == 0xa1)
|
|
{
|
|
// movl XX,%eax ==> movl $YY,%eax
|
|
view[-1] = 0xb8;
|
|
}
|
|
else
|
|
{
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
|
|
|
|
unsigned char op2 = view[-2];
|
|
if (op2 == 0x8b)
|
|
{
|
|
// movl XX,%reg ==> movl $YY,%reg
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
(op1 & 0xc7) == 0x05);
|
|
view[-2] = 0xc7;
|
|
view[-1] = 0xc0 | ((op1 >> 3) & 7);
|
|
}
|
|
else if (op2 == 0x03)
|
|
{
|
|
// addl XX,%reg ==> addl $YY,%reg
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
(op1 & 0xc7) == 0x05);
|
|
view[-2] = 0x81;
|
|
view[-1] = 0xc0 | ((op1 >> 3) & 7);
|
|
}
|
|
else
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
|
|
// movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
|
|
// addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, -2);
|
|
tls::check_range(relinfo, relnum, rel.get_r_offset(), view_size, 4);
|
|
|
|
unsigned char op1 = view[-1];
|
|
unsigned char op2 = view[-2];
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(),
|
|
(op1 & 0xc0) == 0x80 && (op1 & 7) != 4);
|
|
if (op2 == 0x8b)
|
|
{
|
|
// movl %gs:XX(%reg1),%reg2 ==> movl $YY,%reg2
|
|
view[-2] = 0xc7;
|
|
view[-1] = 0xc0 | ((op1 >> 3) & 7);
|
|
}
|
|
else if (op2 == 0x2b)
|
|
{
|
|
// subl %gs:XX(%reg1),%reg2 ==> subl $YY,%reg2
|
|
view[-2] = 0x81;
|
|
view[-1] = 0xe8 | ((op1 >> 3) & 7);
|
|
}
|
|
else if (op2 == 0x03)
|
|
{
|
|
// addl %gs:XX(%reg1),%reg2 ==> addl $YY,$reg2
|
|
view[-2] = 0x81;
|
|
view[-1] = 0xc0 | ((op1 >> 3) & 7);
|
|
}
|
|
else
|
|
tls::check_tls(relinfo, relnum, rel.get_r_offset(), 0);
|
|
}
|
|
|
|
value = tls_segment->memsz() - value;
|
|
if (r_type == elfcpp::R_386_TLS_IE || r_type == elfcpp::R_386_TLS_GOTIE)
|
|
value = - value;
|
|
|
|
Relocate_functions<32, false>::rel32(view, value);
|
|
}
|
|
|
|
// Relocate section data.
|
|
|
|
void
|
|
Target_i386::relocate_section(const Relocate_info<32, false>* relinfo,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
Output_section* output_section,
|
|
bool needs_special_offset_handling,
|
|
unsigned char* view,
|
|
elfcpp::Elf_types<32>::Elf_Addr address,
|
|
section_size_type view_size)
|
|
{
|
|
gold_assert(sh_type == elfcpp::SHT_REL);
|
|
|
|
gold::relocate_section<32, false, Target_i386, elfcpp::SHT_REL,
|
|
Target_i386::Relocate>(
|
|
relinfo,
|
|
this,
|
|
prelocs,
|
|
reloc_count,
|
|
output_section,
|
|
needs_special_offset_handling,
|
|
view,
|
|
address,
|
|
view_size);
|
|
}
|
|
|
|
// Return the size of a relocation while scanning during a relocatable
|
|
// link.
|
|
|
|
unsigned int
|
|
Target_i386::Relocatable_size_for_reloc::get_size_for_reloc(
|
|
unsigned int r_type,
|
|
Relobj* object)
|
|
{
|
|
switch (r_type)
|
|
{
|
|
case elfcpp::R_386_NONE:
|
|
case elfcpp::R_386_GNU_VTINHERIT:
|
|
case elfcpp::R_386_GNU_VTENTRY:
|
|
case elfcpp::R_386_TLS_GD: // Global-dynamic
|
|
case elfcpp::R_386_TLS_GOTDESC: // Global-dynamic (from ~oliva url)
|
|
case elfcpp::R_386_TLS_DESC_CALL:
|
|
case elfcpp::R_386_TLS_LDM: // Local-dynamic
|
|
case elfcpp::R_386_TLS_LDO_32: // Alternate local-dynamic
|
|
case elfcpp::R_386_TLS_IE: // Initial-exec
|
|
case elfcpp::R_386_TLS_IE_32:
|
|
case elfcpp::R_386_TLS_GOTIE:
|
|
case elfcpp::R_386_TLS_LE: // Local-exec
|
|
case elfcpp::R_386_TLS_LE_32:
|
|
return 0;
|
|
|
|
case elfcpp::R_386_32:
|
|
case elfcpp::R_386_PC32:
|
|
case elfcpp::R_386_GOT32:
|
|
case elfcpp::R_386_PLT32:
|
|
case elfcpp::R_386_GOTOFF:
|
|
case elfcpp::R_386_GOTPC:
|
|
return 4;
|
|
|
|
case elfcpp::R_386_16:
|
|
case elfcpp::R_386_PC16:
|
|
return 2;
|
|
|
|
case elfcpp::R_386_8:
|
|
case elfcpp::R_386_PC8:
|
|
return 1;
|
|
|
|
// These are relocations which should only be seen by the
|
|
// dynamic linker, and should never be seen here.
|
|
case elfcpp::R_386_COPY:
|
|
case elfcpp::R_386_GLOB_DAT:
|
|
case elfcpp::R_386_JUMP_SLOT:
|
|
case elfcpp::R_386_RELATIVE:
|
|
case elfcpp::R_386_TLS_TPOFF:
|
|
case elfcpp::R_386_TLS_DTPMOD32:
|
|
case elfcpp::R_386_TLS_DTPOFF32:
|
|
case elfcpp::R_386_TLS_TPOFF32:
|
|
case elfcpp::R_386_TLS_DESC:
|
|
object->error(_("unexpected reloc %u in object file"), r_type);
|
|
return 0;
|
|
|
|
case elfcpp::R_386_32PLT:
|
|
case elfcpp::R_386_TLS_GD_32:
|
|
case elfcpp::R_386_TLS_GD_PUSH:
|
|
case elfcpp::R_386_TLS_GD_CALL:
|
|
case elfcpp::R_386_TLS_GD_POP:
|
|
case elfcpp::R_386_TLS_LDM_32:
|
|
case elfcpp::R_386_TLS_LDM_PUSH:
|
|
case elfcpp::R_386_TLS_LDM_CALL:
|
|
case elfcpp::R_386_TLS_LDM_POP:
|
|
case elfcpp::R_386_USED_BY_INTEL_200:
|
|
default:
|
|
object->error(_("unsupported reloc %u in object file"), r_type);
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
// Scan the relocs during a relocatable link.
|
|
|
|
void
|
|
Target_i386::scan_relocatable_relocs(const General_options& options,
|
|
Symbol_table* symtab,
|
|
Layout* layout,
|
|
Sized_relobj<32, false>* object,
|
|
unsigned int data_shndx,
|
|
unsigned int sh_type,
|
|
const unsigned char* prelocs,
|
|
size_t reloc_count,
|
|
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_REL);
|
|
|
|
typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_REL,
|
|
Relocatable_size_for_reloc> Scan_relocatable_relocs;
|
|
|
|
gold::scan_relocatable_relocs<32, false, elfcpp::SHT_REL,
|
|
Scan_relocatable_relocs>(
|
|
options,
|
|
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_i386::relocate_for_relocatable(
|
|
const Relocate_info<32, 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<32>::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_REL);
|
|
|
|
gold::relocate_for_relocatable<32, false, elfcpp::SHT_REL>(
|
|
relinfo,
|
|
prelocs,
|
|
reloc_count,
|
|
output_section,
|
|
offset_in_output_section,
|
|
rr,
|
|
view,
|
|
view_address,
|
|
view_size,
|
|
reloc_view,
|
|
reloc_view_size);
|
|
}
|
|
|
|
// Return the value to use for a dynamic which requires special
|
|
// treatment. This is how we support equality comparisons of function
|
|
// pointers across shared library boundaries, as described in the
|
|
// processor specific ABI supplement.
|
|
|
|
uint64_t
|
|
Target_i386::do_dynsym_value(const Symbol* gsym) const
|
|
{
|
|
gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
|
|
return this->plt_section()->address() + gsym->plt_offset();
|
|
}
|
|
|
|
// Return a string used to fill a code section with nops to take up
|
|
// the specified length.
|
|
|
|
std::string
|
|
Target_i386::do_code_fill(section_size_type length) const
|
|
{
|
|
if (length >= 16)
|
|
{
|
|
// Build a jmp instruction to skip over the bytes.
|
|
unsigned char jmp[5];
|
|
jmp[0] = 0xe9;
|
|
elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
|
|
return (std::string(reinterpret_cast<char*>(&jmp[0]), 5)
|
|
+ std::string(length - 5, '\0'));
|
|
}
|
|
|
|
// Nop sequences of various lengths.
|
|
const char nop1[1] = { 0x90 }; // nop
|
|
const char nop2[2] = { 0x66, 0x90 }; // xchg %ax %ax
|
|
const char nop3[3] = { 0x8d, 0x76, 0x00 }; // leal 0(%esi),%esi
|
|
const char nop4[4] = { 0x8d, 0x74, 0x26, 0x00}; // leal 0(%esi,1),%esi
|
|
const char nop5[5] = { 0x90, 0x8d, 0x74, 0x26, // nop
|
|
0x00 }; // leal 0(%esi,1),%esi
|
|
const char nop6[6] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
|
|
0x00, 0x00 };
|
|
const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
|
|
0x00, 0x00, 0x00 };
|
|
const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
|
|
0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
|
|
const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
|
|
0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
|
|
0x00 };
|
|
const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
|
|
0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
|
|
0x00, 0x00 };
|
|
const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
|
|
0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
|
|
0x00, 0x00, 0x00 };
|
|
const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
|
|
0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
|
|
0x00, 0x00, 0x00, 0x00 };
|
|
const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
|
|
0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
|
|
0x27, 0x00, 0x00, 0x00,
|
|
0x00 };
|
|
const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
|
|
0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
|
|
0xbc, 0x27, 0x00, 0x00,
|
|
0x00, 0x00 };
|
|
const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
|
|
0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
|
|
0x90, 0x90, 0x90, 0x90,
|
|
0x90, 0x90, 0x90 };
|
|
|
|
const char* nops[16] = {
|
|
NULL,
|
|
nop1, nop2, nop3, nop4, nop5, nop6, nop7,
|
|
nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
|
|
};
|
|
|
|
return std::string(nops[length], length);
|
|
}
|
|
|
|
// The selector for i386 object files.
|
|
|
|
class Target_selector_i386 : public Target_selector_freebsd
|
|
{
|
|
public:
|
|
Target_selector_i386()
|
|
: Target_selector_freebsd(elfcpp::EM_386, 32, false,
|
|
"elf32-i386", "elf32-i386-freebsd")
|
|
{ }
|
|
|
|
Target*
|
|
do_instantiate_target()
|
|
{ return new Target_i386(); }
|
|
};
|
|
|
|
Target_selector_i386 target_selector_i386;
|
|
|
|
} // End anonymous namespace.
|