--- /dev/null
+// x86_64.cc -- x86_64 target support for gold.
+
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+// Written by Ian Lance Taylor <iant@google.com>.
+
+// This file is part of gold.
+
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
+// (at your option) any later version.
+
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
+
+#include "gold.h"
+
+#include <cstring>
+
+#include "elfcpp.h"
+#include "parameters.h"
+#include "reloc.h"
+#include "x86_64.h"
+#include "object.h"
+#include "symtab.h"
+#include "layout.h"
+#include "output.h"
+#include "copy-relocs.h"
+#include "target.h"
+#include "target-reloc.h"
+#include "target-select.h"
+#include "tls.h"
+#include "freebsd.h"
+#include "gc.h"
+
+namespace
+{
+
+using namespace gold;
+
+class Output_data_plt_x86_64;
+
+// The x86_64 target class.
+// See the ABI at
+// http://www.x86-64.org/documentation/abi.pdf
+// TLS info comes from
+// http://people.redhat.com/drepper/tls.pdf
+// http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
+
+class Target_x86_64 : public Target_freebsd<64, false>
+{
+ public:
+ // In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
+ // uses only Elf64_Rela relocation entries with explicit addends."
+ typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
+
+ Target_x86_64()
+ : Target_freebsd<64, false>(&x86_64_info),
+ got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL),
+ copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),
+ got_mod_index_offset_(-1U), tls_base_symbol_defined_(false)
+ { }
+
+ // Hook for a new output section.
+ void
+ do_new_output_section(Output_section*) const;
+
+ // Scan the relocations to look for symbol adjustments.
+ void
+ gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols);
+
+ // Scan the relocations to look for symbol adjustments.
+ void
+ scan_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols);
+
+ // Finalize the sections.
+ void
+ do_finalize_sections(Layout*);
+
+ // Return the value to use for a dynamic which requires special
+ // treatment.
+ uint64_t
+ do_dynsym_value(const Symbol*) const;
+
+ // Relocate a section.
+ void
+ relocate_section(const Relocate_info<64, false>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr view_address,
+ section_size_type view_size,
+ const Reloc_symbol_changes*);
+
+ // Scan the relocs during a relocatable link.
+ void
+ scan_relocatable_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols,
+ Relocatable_relocs*);
+
+ // Relocate a section during a relocatable link.
+ void
+ relocate_for_relocatable(const Relocate_info<64, false>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs*,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size);
+
+ // Return a string used to fill a code section with nops.
+ std::string
+ do_code_fill(section_size_type length) const;
+
+ // Return whether SYM is defined by the ABI.
+ bool
+ do_is_defined_by_abi(const Symbol* sym) const
+ { return strcmp(sym->name(), "__tls_get_addr") == 0; }
+
+ // Adjust -fstack-split code which calls non-stack-split code.
+ void
+ do_calls_non_split(Relobj* object, unsigned int shndx,
+ section_offset_type fnoffset, section_size_type fnsize,
+ unsigned char* view, section_size_type view_size,
+ std::string* from, std::string* to) const;
+
+ // Return the size of the GOT section.
+ section_size_type
+ got_size()
+ {
+ gold_assert(this->got_ != NULL);
+ return this->got_->data_size();
+ }
+
+ private:
+ // The class which scans relocations.
+ class Scan
+ {
+ public:
+ Scan()
+ : issued_non_pic_error_(false)
+ { }
+
+ inline void
+ local(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Target_x86_64* target,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
+ const elfcpp::Sym<64, false>& lsym);
+
+ inline void
+ global(const General_options& options, Symbol_table* symtab,
+ Layout* layout, Target_x86_64* target,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
+ Symbol* gsym);
+
+ private:
+ static void
+ unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
+
+ static void
+ unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type,
+ Symbol*);
+
+ void
+ check_non_pic(Relobj*, unsigned int r_type);
+
+ // Whether we have issued an error about a non-PIC compilation.
+ bool issued_non_pic_error_;
+ };
+
+ // The class which implements relocation.
+ class Relocate
+ {
+ public:
+ Relocate()
+ : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
+ { }
+
+ ~Relocate()
+ {
+ if (this->skip_call_tls_get_addr_)
+ {
+ // FIXME: This needs to specify the location somehow.
+ gold_error(_("missing expected TLS relocation"));
+ }
+ }
+
+ // Do a relocation. Return false if the caller should not issue
+ // any warnings about this relocation.
+ inline bool
+ relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*,
+ size_t relnum, const elfcpp::Rela<64, false>&,
+ unsigned int r_type, const Sized_symbol<64>*,
+ const Symbol_value<64>*,
+ unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
+ section_size_type);
+
+ private:
+ // Do a TLS relocation.
+ inline void
+ relocate_tls(const Relocate_info<64, false>*, Target_x86_64*,
+ size_t relnum, const elfcpp::Rela<64, false>&,
+ unsigned int r_type, const Sized_symbol<64>*,
+ const Symbol_value<64>*,
+ unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
+ section_size_type);
+
+ // Do a TLS General-Dynamic to Initial-Exec transition.
+ inline void
+ tls_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>&, unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr,
+ section_size_type view_size);
+
+ // Do a TLS General-Dynamic to Local-Exec transition.
+ inline void
+ tls_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>&, unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size);
+
+ // Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
+ inline void
+ tls_desc_gd_to_ie(const Relocate_info<64, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>&, unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr,
+ section_size_type view_size);
+
+ // Do a TLSDESC-style General-Dynamic to Local-Exec transition.
+ inline void
+ tls_desc_gd_to_le(const Relocate_info<64, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>&, unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size);
+
+ // Do a TLS Local-Dynamic to Local-Exec transition.
+ inline void
+ tls_ld_to_le(const Relocate_info<64, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>&, unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size);
+
+ // Do a TLS Initial-Exec to Local-Exec transition.
+ static inline void
+ tls_ie_to_le(const Relocate_info<64, false>*, size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>&, unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size);
+
+ // This is set if we should skip the next reloc, which should be a
+ // PLT32 reloc against ___tls_get_addr.
+ bool skip_call_tls_get_addr_;
+
+ // This is set if we see a relocation which could load the address
+ // of the TLS block. Whether we see such a relocation determines
+ // how we handle the R_X86_64_DTPOFF32 relocation, which is used
+ // in debugging sections.
+ bool saw_tls_block_reloc_;
+ };
+
+ // A class which returns the size required for a relocation type,
+ // used while scanning relocs during a relocatable link.
+ class Relocatable_size_for_reloc
+ {
+ public:
+ unsigned int
+ get_size_for_reloc(unsigned int, Relobj*);
+ };
+
+ // Adjust TLS relocation type based on the options and whether this
+ // is a local symbol.
+ static tls::Tls_optimization
+ optimize_tls_reloc(bool is_final, int r_type);
+
+ // Get the GOT section, creating it if necessary.
+ Output_data_got<64, false>*
+ got_section(Symbol_table*, Layout*);
+
+ // Get the GOT PLT section.
+ Output_data_space*
+ got_plt_section() const
+ {
+ gold_assert(this->got_plt_ != NULL);
+ return this->got_plt_;
+ }
+
+ // Create the PLT section.
+ void
+ make_plt_section(Symbol_table* symtab, Layout* layout);
+
+ // Create a PLT entry for a global symbol.
+ void
+ make_plt_entry(Symbol_table*, Layout*, Symbol*);
+
+ // Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
+ void
+ define_tls_base_symbol(Symbol_table*, Layout*);
+
+ // Create the reserved PLT and GOT entries for the TLS descriptor resolver.
+ void
+ reserve_tlsdesc_entries(Symbol_table* symtab, Layout* layout);
+
+ // Create a GOT entry for the TLS module index.
+ unsigned int
+ got_mod_index_entry(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<64, false>* object);
+
+ // Get the PLT section.
+ Output_data_plt_x86_64*
+ plt_section() const
+ {
+ gold_assert(this->plt_ != NULL);
+ return this->plt_;
+ }
+
+ // Get the dynamic reloc section, creating it if necessary.
+ Reloc_section*
+ rela_dyn_section(Layout*);
+
+ // Add a potential copy relocation.
+ void
+ copy_reloc(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int shndx, Output_section* output_section,
+ Symbol* sym, const elfcpp::Rela<64, false>& reloc)
+ {
+ this->copy_relocs_.copy_reloc(symtab, layout,
+ symtab->get_sized_symbol<64>(sym),
+ object, shndx, output_section,
+ reloc, this->rela_dyn_section(layout));
+ }
+
+ // Information about this specific target which we pass to the
+ // general Target structure.
+ static const Target::Target_info x86_64_info;
+
+ enum Got_type
+ {
+ GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
+ GOT_TYPE_TLS_OFFSET = 1, // GOT entry for TLS offset
+ GOT_TYPE_TLS_PAIR = 2, // GOT entry for TLS module/offset pair
+ GOT_TYPE_TLS_DESC = 3 // GOT entry for TLS_DESC pair
+ };
+
+ // The GOT section.
+ Output_data_got<64, false>* got_;
+ // The PLT section.
+ Output_data_plt_x86_64* plt_;
+ // The GOT PLT section.
+ Output_data_space* got_plt_;
+ // The dynamic reloc section.
+ Reloc_section* rela_dyn_;
+ // Relocs saved to avoid a COPY reloc.
+ Copy_relocs<elfcpp::SHT_RELA, 64, false> copy_relocs_;
+ // Space for variables copied with a COPY reloc.
+ Output_data_space* dynbss_;
+ // Offset of the GOT entry for the TLS module index.
+ unsigned int got_mod_index_offset_;
+ // True if the _TLS_MODULE_BASE_ symbol has been defined.
+ bool tls_base_symbol_defined_;
+};
+
+const Target::Target_info Target_x86_64::x86_64_info =
+{
+ 64, // size
+ false, // is_big_endian
+ elfcpp::EM_X86_64, // machine_code
+ false, // has_make_symbol
+ false, // has_resolve
+ true, // has_code_fill
+ true, // is_default_stack_executable
+ '\0', // wrap_char
+ "/lib/ld64.so.1", // program interpreter
+ 0x400000, // default_text_segment_address
+ 0x1000, // abi_pagesize (overridable by -z max-page-size)
+ 0x1000, // common_pagesize (overridable by -z common-page-size)
+ elfcpp::SHN_UNDEF, // small_common_shndx
+ elfcpp::SHN_X86_64_LCOMMON, // large_common_shndx
+ 0, // small_common_section_flags
+ elfcpp::SHF_X86_64_LARGE // large_common_section_flags
+};
+
+// This is called when a new output section is created. This is where
+// we handle the SHF_X86_64_LARGE.
+
+void
+Target_x86_64::do_new_output_section(Output_section *os) const
+{
+ if ((os->flags() & elfcpp::SHF_X86_64_LARGE) != 0)
+ os->set_is_large_section();
+}
+
+// Get the GOT section, creating it if necessary.
+
+Output_data_got<64, false>*
+Target_x86_64::got_section(Symbol_table* symtab, Layout* layout)
+{
+ if (this->got_ == NULL)
+ {
+ gold_assert(symtab != NULL && layout != NULL);
+
+ this->got_ = new Output_data_got<64, 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(8, "** 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 * 8);
+
+ // 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_x86_64::Reloc_section*
+Target_x86_64::rela_dyn_section(Layout* layout)
+{
+ if (this->rela_dyn_ == NULL)
+ {
+ gold_assert(layout != NULL);
+ this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
+ layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
+ elfcpp::SHF_ALLOC, this->rela_dyn_);
+ }
+ return this->rela_dyn_;
+}
+
+// A class to handle the PLT data.
+
+class Output_data_plt_x86_64 : public Output_section_data
+{
+ public:
+ typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
+
+ Output_data_plt_x86_64(Layout*, Output_data_got<64, false>*,
+ Output_data_space*);
+
+ // Add an entry to the PLT.
+ void
+ add_entry(Symbol* gsym);
+
+ // Add the reserved TLSDESC_PLT entry to the PLT.
+ void
+ reserve_tlsdesc_entry(unsigned int got_offset)
+ { this->tlsdesc_got_offset_ = got_offset; }
+
+ // Return true if a TLSDESC_PLT entry has been reserved.
+ bool
+ has_tlsdesc_entry() const
+ { return this->tlsdesc_got_offset_ != -1U; }
+
+ // Return the GOT offset for the reserved TLSDESC_PLT entry.
+ unsigned int
+ get_tlsdesc_got_offset() const
+ { return this->tlsdesc_got_offset_; }
+
+ // Return the offset of the reserved TLSDESC_PLT entry.
+ unsigned int
+ get_tlsdesc_plt_offset() const
+ { return (this->count_ + 1) * plt_entry_size; }
+
+ // Return the .rel.plt section data.
+ const Reloc_section*
+ rel_plt() const
+ { 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.
+ // From the AMD64 ABI: "Unlike Intel386 ABI, this ABI uses the same
+ // procedure linkage table for both programs and shared objects."
+ static unsigned char first_plt_entry[plt_entry_size];
+
+ // Other entries in the PLT for an executable.
+ static unsigned char plt_entry[plt_entry_size];
+
+ // The reserved TLSDESC entry in the PLT for an executable.
+ static unsigned char tlsdesc_plt_entry[plt_entry_size];
+
+ // Set the final size.
+ void
+ set_final_data_size();
+
+ // Write out the PLT data.
+ void
+ do_write(Output_file*);
+
+ // The reloc section.
+ Reloc_section* rel_;
+ // The .got section.
+ Output_data_got<64, false>* got_;
+ // The .got.plt section.
+ Output_data_space* got_plt_;
+ // The number of PLT entries.
+ unsigned int count_;
+ // Offset of the reserved TLSDESC_GOT entry when needed.
+ unsigned int tlsdesc_got_offset_;
+};
+
+// Create the PLT section. The ordinary .got section is an argument,
+// since we need to refer to the start. We also create our own .got
+// section just for PLT entries.
+
+Output_data_plt_x86_64::Output_data_plt_x86_64(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_space* got_plt)
+ : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0),
+ tlsdesc_got_offset_(-1U)
+{
+ this->rel_ = new Reloc_section(false);
+ layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
+ elfcpp::SHF_ALLOC, this->rel_);
+}
+
+void
+Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
+{
+ os->set_entsize(plt_entry_size);
+}
+
+// Add an entry to the PLT.
+
+void
+Output_data_plt_x86_64::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 + 8);
+
+ // Every PLT entry needs a reloc.
+ gsym->set_needs_dynsym_entry();
+ this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
+ got_offset, 0);
+
+ // 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.
+}
+
+// Set the final size.
+void
+Output_data_plt_x86_64::set_final_data_size()
+{
+ unsigned int count = this->count_;
+ if (this->has_tlsdesc_entry())
+ ++count;
+ this->set_data_size((count + 1) * plt_entry_size);
+}
+
+// The first entry in the PLT for an executable.
+
+unsigned char Output_data_plt_x86_64::first_plt_entry[plt_entry_size] =
+{
+ // From AMD64 ABI Draft 0.98, page 76
+ 0xff, 0x35, // pushq contents of memory address
+ 0, 0, 0, 0, // replaced with address of .got + 8
+ 0xff, 0x25, // jmp indirect
+ 0, 0, 0, 0, // replaced with address of .got + 16
+ 0x90, 0x90, 0x90, 0x90 // noop (x4)
+};
+
+// Subsequent entries in the PLT for an executable.
+
+unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
+{
+ // From AMD64 ABI Draft 0.98, page 76
+ 0xff, 0x25, // jmpq indirect
+ 0, 0, 0, 0, // replaced with address of symbol in .got
+ 0x68, // pushq immediate
+ 0, 0, 0, 0, // replaced with offset into relocation table
+ 0xe9, // jmpq relative
+ 0, 0, 0, 0 // replaced with offset to start of .plt
+};
+
+// The reserved TLSDESC entry in the PLT for an executable.
+
+unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry[plt_entry_size] =
+{
+ // From Alexandre Oliva, "Thread-Local Storage Descriptors for IA32
+ // and AMD64/EM64T", Version 0.9.4 (2005-10-10).
+ 0xff, 0x35, // pushq x(%rip)
+ 0, 0, 0, 0, // replaced with address of linkmap GOT entry (at PLTGOT + 8)
+ 0xff, 0x25, // jmpq *y(%rip)
+ 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
+ 0x0f, 0x1f, // nop
+ 0x40, 0
+};
+
+// Write out the PLT. This uses the hand-coded instructions above,
+// and adjusts them as needed. This is specified by the AMD64 ABI.
+
+void
+Output_data_plt_x86_64::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;
+
+ // The base address of the .plt section.
+ elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
+ // The base address of the .got section.
+ elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
+ // The base address of the PLT portion of the .got section,
+ // which is where the GOT pointer will point, and where the
+ // three reserved GOT entries are located.
+ elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
+
+ memcpy(pov, first_plt_entry, plt_entry_size);
+ // We do a jmp relative to the PC at the end of this instruction.
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
+ (got_address + 8
+ - (plt_address + 6)));
+ elfcpp::Swap<32, false>::writeval(pov + 8,
+ (got_address + 16
+ - (plt_address + 12)));
+ pov += plt_entry_size;
+
+ unsigned char* got_pov = got_view;
+
+ memset(got_pov, 0, 24);
+ got_pov += 24;
+
+ unsigned int plt_offset = plt_entry_size;
+ unsigned int got_offset = 24;
+ const unsigned int count = this->count_;
+ for (unsigned int plt_index = 0;
+ plt_index < count;
+ ++plt_index,
+ pov += plt_entry_size,
+ got_pov += 8,
+ plt_offset += plt_entry_size,
+ got_offset += 8)
+ {
+ // Set and adjust the PLT entry itself.
+ memcpy(pov, plt_entry, plt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
+ (got_address + got_offset
+ - (plt_address + plt_offset
+ + 6)));
+
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
+ elfcpp::Swap<32, false>::writeval(pov + 12,
+ - (plt_offset + plt_entry_size));
+
+ // Set the entry in the GOT.
+ elfcpp::Swap<64, false>::writeval(got_pov, plt_address + plt_offset + 6);
+ }
+
+ if (this->has_tlsdesc_entry())
+ {
+ // Set and adjust the reserved TLSDESC PLT entry.
+ unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
+ memcpy(pov, tlsdesc_plt_entry, plt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
+ (got_address + 8
+ - (plt_address + plt_offset
+ + 6)));
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
+ (got_base
+ + tlsdesc_got_offset
+ - (plt_address + plt_offset
+ + 12)));
+ pov += plt_entry_size;
+ }
+
+ gold_assert(static_cast<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 the PLT section.
+
+void
+Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout)
+{
+ if (this->plt_ == NULL)
+ {
+ // Create the GOT sections first.
+ this->got_section(symtab, layout);
+
+ this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
+ this->got_plt_);
+ layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_EXECINSTR),
+ this->plt_);
+ }
+}
+
+// Create a PLT entry for a global symbol.
+
+void
+Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
+ Symbol* gsym)
+{
+ if (gsym->has_plt_offset())
+ return;
+
+ if (this->plt_ == NULL)
+ this->make_plt_section(symtab, layout);
+
+ this->plt_->add_entry(gsym);
+}
+
+// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
+
+void
+Target_x86_64::define_tls_base_symbol(Symbol_table* symtab, Layout* layout)
+{
+ if (this->tls_base_symbol_defined_)
+ return;
+
+ Output_segment* tls_segment = layout->tls_segment();
+ if (tls_segment != NULL)
+ {
+ bool is_exec = parameters->options().output_is_executable();
+ symtab->define_in_output_segment("_TLS_MODULE_BASE_", NULL,
+ tls_segment, 0, 0,
+ elfcpp::STT_TLS,
+ elfcpp::STB_LOCAL,
+ elfcpp::STV_HIDDEN, 0,
+ (is_exec
+ ? Symbol::SEGMENT_END
+ : Symbol::SEGMENT_START),
+ true);
+ }
+ this->tls_base_symbol_defined_ = true;
+}
+
+// Create the reserved PLT and GOT entries for the TLS descriptor resolver.
+
+void
+Target_x86_64::reserve_tlsdesc_entries(Symbol_table* symtab,
+ Layout* layout)
+{
+ if (this->plt_ == NULL)
+ this->make_plt_section(symtab, layout);
+
+ if (!this->plt_->has_tlsdesc_entry())
+ {
+ // Allocate the TLSDESC_GOT entry.
+ Output_data_got<64, false>* got = this->got_section(symtab, layout);
+ unsigned int got_offset = got->add_constant(0);
+
+ // Allocate the TLSDESC_PLT entry.
+ this->plt_->reserve_tlsdesc_entry(got_offset);
+ }
+}
+
+// Create a GOT entry for the TLS module index.
+
+unsigned int
+Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
+ Sized_relobj<64, false>* object)
+{
+ if (this->got_mod_index_offset_ == -1U)
+ {
+ gold_assert(symtab != NULL && layout != NULL && object != NULL);
+ Reloc_section* rela_dyn = this->rela_dyn_section(layout);
+ Output_data_got<64, false>* got = this->got_section(symtab, layout);
+ unsigned int got_offset = got->add_constant(0);
+ rela_dyn->add_local(object, 0, elfcpp::R_X86_64_DTPMOD64, got,
+ got_offset, 0);
+ got->add_constant(0);
+ this->got_mod_index_offset_ = got_offset;
+ }
+ return this->got_mod_index_offset_;
+}
+
+// Optimize the TLS relocation type based on what we know about the
+// symbol. IS_FINAL is true if the final address of this symbol is
+// known at link time.
+
+tls::Tls_optimization
+Target_x86_64::optimize_tls_reloc(bool is_final, int r_type)
+{
+ // If we are generating a shared library, then we can't do anything
+ // in the linker.
+ if (parameters->options().shared())
+ return tls::TLSOPT_NONE;
+
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_TLSGD:
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC:
+ case elfcpp::R_X86_64_TLSDESC_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_X86_64_TLSLD:
+ // 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_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ // Another Local-Dynamic reloc.
+ return tls::TLSOPT_TO_LE;
+
+ case elfcpp::R_X86_64_GOTTPOFF:
+ // 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_X86_64_TPOFF32:
+ // 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_x86_64::Scan::unsupported_reloc_local(Sized_relobj<64, false>* object,
+ unsigned int r_type)
+{
+ gold_error(_("%s: unsupported reloc %u against local symbol"),
+ object->name().c_str(), r_type);
+}
+
+// We are about to emit a dynamic relocation of type R_TYPE. If the
+// dynamic linker does not support it, issue an error. The GNU linker
+// only issues a non-PIC error for an allocated read-only section.
+// Here we know the section is allocated, but we don't know that it is
+// read-only. But we check for all the relocation types which the
+// glibc dynamic linker supports, so it seems appropriate to issue an
+// error even if the section is not read-only.
+
+void
+Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type)
+{
+ switch (r_type)
+ {
+ // These are the relocation types supported by glibc for x86_64.
+ case elfcpp::R_X86_64_RELATIVE:
+ case elfcpp::R_X86_64_GLOB_DAT:
+ case elfcpp::R_X86_64_JUMP_SLOT:
+ case elfcpp::R_X86_64_DTPMOD64:
+ case elfcpp::R_X86_64_DTPOFF64:
+ case elfcpp::R_X86_64_TPOFF64:
+ case elfcpp::R_X86_64_64:
+ case elfcpp::R_X86_64_32:
+ case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_COPY:
+ return;
+
+ default:
+ // This prevents us from issuing more than one error per reloc
+ // section. But we can still wind up issuing more than one
+ // error per object file.
+ if (this->issued_non_pic_error_)
+ return;
+ gold_assert(parameters->options().output_is_position_independent());
+ object->error(_("requires unsupported dynamic reloc; "
+ "recompile with -fPIC"));
+ this->issued_non_pic_error_ = true;
+ return;
+
+ case elfcpp::R_X86_64_NONE:
+ gold_unreachable();
+ }
+}
+
+// Scan a relocation for a local symbol.
+
+inline void
+Target_x86_64::Scan::local(const General_options&,
+ Symbol_table* symtab,
+ Layout* layout,
+ Target_x86_64* target,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rela<64, false>& reloc,
+ unsigned int r_type,
+ const elfcpp::Sym<64, false>& lsym)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ break;
+
+ case elfcpp::R_X86_64_64:
+ // If building a shared library (or a position-independent
+ // executable), we need to create a dynamic relocation for this
+ // location. The relocation applied at link time will apply the
+ // link-time value, so we flag the location with an
+ // R_X86_64_RELATIVE relocation so the dynamic loader can
+ // relocate it easily.
+ if (parameters->options().output_is_position_independent())
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ rela_dyn->add_local_relative(object, r_sym,
+ elfcpp::R_X86_64_RELATIVE,
+ output_section, data_shndx,
+ reloc.get_r_offset(),
+ reloc.get_r_addend());
+ }
+ break;
+
+ case elfcpp::R_X86_64_32:
+ case elfcpp::R_X86_64_32S:
+ case elfcpp::R_X86_64_16:
+ case elfcpp::R_X86_64_8:
+ // If building a shared library (or a position-independent
+ // executable), we need to create a dynamic relocation for this
+ // location. We can't use an R_X86_64_RELATIVE relocation
+ // because that is always a 64-bit relocation.
+ if (parameters->options().output_is_position_independent())
+ {
+ this->check_non_pic(object, r_type);
+
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
+ if (lsym.get_st_type() != elfcpp::STT_SECTION)
+ rela_dyn->add_local(object, r_sym, r_type, output_section,
+ data_shndx, reloc.get_r_offset(),
+ reloc.get_r_addend());
+ else
+ {
+ gold_assert(lsym.get_st_value() == 0);
+ unsigned int shndx = lsym.get_st_shndx();
+ bool is_ordinary;
+ shndx = object->adjust_sym_shndx(r_sym, shndx,
+ &is_ordinary);
+ if (!is_ordinary)
+ object->error(_("section symbol %u has bad shndx %u"),
+ r_sym, shndx);
+ else
+ rela_dyn->add_local_section(object, shndx,
+ r_type, output_section,
+ data_shndx, reloc.get_r_offset(),
+ reloc.get_r_addend());
+ }
+ }
+ break;
+
+ case elfcpp::R_X86_64_PC64:
+ case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PC16:
+ case elfcpp::R_X86_64_PC8:
+ break;
+
+ case elfcpp::R_X86_64_PLT32:
+ // Since we know this is a local symbol, we can handle this as a
+ // PC32 reloc.
+ break;
+
+ case elfcpp::R_X86_64_GOTPC32:
+ case elfcpp::R_X86_64_GOTOFF64:
+ case elfcpp::R_X86_64_GOTPC64:
+ case elfcpp::R_X86_64_PLTOFF64:
+ // We need a GOT section.
+ target->got_section(symtab, layout);
+ // For PLTOFF64, we'd normally want a PLT section, but since we
+ // know this is a local symbol, no PLT is needed.
+ break;
+
+ case elfcpp::R_X86_64_GOT64:
+ case elfcpp::R_X86_64_GOT32:
+ case elfcpp::R_X86_64_GOTPCREL64:
+ case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPLT64:
+ {
+ // The symbol requires a GOT entry.
+ Output_data_got<64, false>* got = target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
+ if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
+ {
+ // If we are generating a shared object, we need to add a
+ // dynamic relocation for this symbol's GOT entry.
+ if (parameters->options().output_is_position_independent())
+ {
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ // R_X86_64_RELATIVE assumes a 64-bit relocation.
+ if (r_type != elfcpp::R_X86_64_GOT32)
+ rela_dyn->add_local_relative(
+ object, r_sym, elfcpp::R_X86_64_RELATIVE, got,
+ object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
+ else
+ {
+ this->check_non_pic(object, r_type);
+
+ gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
+ rela_dyn->add_local(
+ object, r_sym, r_type, got,
+ object->local_got_offset(r_sym, GOT_TYPE_STANDARD), 0);
+ }
+ }
+ }
+ // For GOTPLT64, we'd normally want a PLT section, but since
+ // we know this is a local symbol, no PLT is needed.
+ }
+ break;
+
+ case elfcpp::R_X86_64_COPY:
+ case elfcpp::R_X86_64_GLOB_DAT:
+ case elfcpp::R_X86_64_JUMP_SLOT:
+ case elfcpp::R_X86_64_RELATIVE:
+ // These are outstanding tls relocs, which are unexpected when linking
+ case elfcpp::R_X86_64_TPOFF64:
+ case elfcpp::R_X86_64_DTPMOD64:
+ case elfcpp::R_X86_64_TLSDESC:
+ 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_X86_64_TLSGD: // Global-dynamic
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_X86_64_TLSDESC_CALL:
+ case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
+ case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ {
+ bool output_is_shared = parameters->options().shared();
+ const tls::Tls_optimization optimized_type
+ = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_TLSGD: // General-dynamic
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a pair of GOT entries for the module index and
+ // dtv-relative offset.
+ Output_data_got<64, false>* got
+ = target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
+ unsigned int shndx = lsym.get_st_shndx();
+ bool is_ordinary;
+ shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
+ if (!is_ordinary)
+ object->error(_("local symbol %u has bad shndx %u"),
+ r_sym, shndx);
+ else
+ got->add_local_pair_with_rela(object, r_sym,
+ shndx,
+ GOT_TYPE_TLS_PAIR,
+ target->rela_dyn_section(layout),
+ elfcpp::R_X86_64_DTPMOD64, 0);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC:
+ target->define_tls_base_symbol(symtab, layout);
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create reserved PLT and GOT entries for the resolver.
+ target->reserve_tlsdesc_entries(symtab, layout);
+
+ // Generate a double GOT entry with an R_X86_64_TLSDESC reloc.
+ Output_data_got<64, false>* got
+ = target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
+ unsigned int shndx = lsym.get_st_shndx();
+ bool is_ordinary;
+ shndx = object->adjust_sym_shndx(r_sym, shndx, &is_ordinary);
+ if (!is_ordinary)
+ object->error(_("local symbol %u has bad shndx %u"),
+ r_sym, shndx);
+ else
+ got->add_local_pair_with_rela(object, r_sym,
+ shndx,
+ GOT_TYPE_TLS_DESC,
+ target->rela_dyn_section(layout),
+ elfcpp::R_X86_64_TLSDESC, 0);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ case elfcpp::R_X86_64_TLSDESC_CALL:
+ break;
+
+ case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a GOT entry for the module index.
+ target->got_mod_index_entry(symtab, layout, object);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ break;
+
+ case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
+ layout->set_has_static_tls();
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a GOT entry for the tp-relative offset.
+ Output_data_got<64, false>* got
+ = target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
+ got->add_local_with_rela(object, r_sym, GOT_TYPE_TLS_OFFSET,
+ target->rela_dyn_section(layout),
+ elfcpp::R_X86_64_TPOFF64);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ layout->set_has_static_tls();
+ if (output_is_shared)
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ default:
+ gold_unreachable();
+ }
+ }
+ break;
+
+ case elfcpp::R_X86_64_SIZE32:
+ case elfcpp::R_X86_64_SIZE64:
+ default:
+ gold_error(_("%s: unsupported reloc %u against local symbol"),
+ object->name().c_str(), r_type);
+ break;
+ }
+}
+
+
+// Report an unsupported relocation against a global symbol.
+
+void
+Target_x86_64::Scan::unsupported_reloc_global(Sized_relobj<64, 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_x86_64::Scan::global(const General_options&,
+ Symbol_table* symtab,
+ Layout* layout,
+ Target_x86_64* target,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ Output_section* output_section,
+ const elfcpp::Rela<64, false>& reloc,
+ unsigned int r_type,
+ Symbol* gsym)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ break;
+
+ case elfcpp::R_X86_64_64:
+ case elfcpp::R_X86_64_32:
+ case elfcpp::R_X86_64_32S:
+ case elfcpp::R_X86_64_16:
+ case elfcpp::R_X86_64_8:
+ {
+ // Make a PLT entry if necessary.
+ if (gsym->needs_plt_entry())
+ {
+ target->make_plt_entry(symtab, layout, gsym);
+ // Since this is not a PC-relative relocation, we may be
+ // taking the address of a function. In that case we need to
+ // set the entry in the dynamic symbol table to the address of
+ // the PLT entry.
+ if (gsym->is_from_dynobj() && !parameters->options().shared())
+ gsym->set_needs_dynsym_value();
+ }
+ // Make a dynamic relocation if necessary.
+ if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
+ {
+ if (gsym->may_need_copy_reloc())
+ {
+ target->copy_reloc(symtab, layout, object,
+ data_shndx, output_section, gsym, reloc);
+ }
+ else if (r_type == elfcpp::R_X86_64_64
+ && gsym->can_use_relative_reloc(false))
+ {
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
+ output_section, object,
+ data_shndx, reloc.get_r_offset(),
+ reloc.get_r_addend());
+ }
+ else
+ {
+ this->check_non_pic(object, r_type);
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ rela_dyn->add_global(gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset(),
+ reloc.get_r_addend());
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_X86_64_PC64:
+ case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PC16:
+ case elfcpp::R_X86_64_PC8:
+ {
+ // Make a PLT entry if necessary.
+ if (gsym->needs_plt_entry())
+ target->make_plt_entry(symtab, layout, gsym);
+ // Make a dynamic relocation if necessary.
+ int flags = Symbol::NON_PIC_REF;
+ if (gsym->type() == elfcpp::STT_FUNC)
+ flags |= Symbol::FUNCTION_CALL;
+ if (gsym->needs_dynamic_reloc(flags))
+ {
+ if (gsym->may_need_copy_reloc())
+ {
+ target->copy_reloc(symtab, layout, object,
+ data_shndx, output_section, gsym, reloc);
+ }
+ else
+ {
+ this->check_non_pic(object, r_type);
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ rela_dyn->add_global(gsym, r_type, output_section, object,
+ data_shndx, reloc.get_r_offset(),
+ reloc.get_r_addend());
+ }
+ }
+ }
+ break;
+
+ case elfcpp::R_X86_64_GOT64:
+ case elfcpp::R_X86_64_GOT32:
+ case elfcpp::R_X86_64_GOTPCREL64:
+ case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPLT64:
+ {
+ // The symbol requires a GOT entry.
+ Output_data_got<64, false>* got = target->got_section(symtab, layout);
+ if (gsym->final_value_is_known())
+ got->add_global(gsym, GOT_TYPE_STANDARD);
+ else
+ {
+ // If this symbol is not fully resolved, we need to add a
+ // dynamic relocation for it.
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ if (gsym->is_from_dynobj()
+ || gsym->is_undefined()
+ || gsym->is_preemptible())
+ got->add_global_with_rela(gsym, GOT_TYPE_STANDARD, rela_dyn,
+ elfcpp::R_X86_64_GLOB_DAT);
+ else
+ {
+ if (got->add_global(gsym, GOT_TYPE_STANDARD))
+ rela_dyn->add_global_relative(
+ gsym, elfcpp::R_X86_64_RELATIVE, got,
+ gsym->got_offset(GOT_TYPE_STANDARD), 0);
+ }
+ }
+ // For GOTPLT64, we also need a PLT entry (but only if the
+ // symbol is not fully resolved).
+ if (r_type == elfcpp::R_X86_64_GOTPLT64
+ && !gsym->final_value_is_known())
+ target->make_plt_entry(symtab, layout, gsym);
+ }
+ break;
+
+ case elfcpp::R_X86_64_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_X86_64_GOTPC32:
+ case elfcpp::R_X86_64_GOTOFF64:
+ case elfcpp::R_X86_64_GOTPC64:
+ case elfcpp::R_X86_64_PLTOFF64:
+ // We need a GOT section.
+ target->got_section(symtab, layout);
+ // For PLTOFF64, we also need a PLT entry (but only if the
+ // symbol is not fully resolved).
+ if (r_type == elfcpp::R_X86_64_PLTOFF64
+ && !gsym->final_value_is_known())
+ target->make_plt_entry(symtab, layout, gsym);
+ break;
+
+ case elfcpp::R_X86_64_COPY:
+ case elfcpp::R_X86_64_GLOB_DAT:
+ case elfcpp::R_X86_64_JUMP_SLOT:
+ case elfcpp::R_X86_64_RELATIVE:
+ // These are outstanding tls relocs, which are unexpected when linking
+ case elfcpp::R_X86_64_TPOFF64:
+ case elfcpp::R_X86_64_DTPMOD64:
+ case elfcpp::R_X86_64_TLSDESC:
+ gold_error(_("%s: unexpected reloc %u in object file"),
+ object->name().c_str(), r_type);
+ break;
+
+ // These are initial tls relocs, which are expected for global()
+ case elfcpp::R_X86_64_TLSGD: // Global-dynamic
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_X86_64_TLSDESC_CALL:
+ case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
+ case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ {
+ const bool is_final = gsym->final_value_is_known();
+ const tls::Tls_optimization optimized_type
+ = Target_x86_64::optimize_tls_reloc(is_final, r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_TLSGD: // General-dynamic
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a pair of GOT entries for the module index and
+ // dtv-relative offset.
+ Output_data_got<64, false>* got
+ = target->got_section(symtab, layout);
+ got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_PAIR,
+ target->rela_dyn_section(layout),
+ elfcpp::R_X86_64_DTPMOD64,
+ elfcpp::R_X86_64_DTPOFF64);
+ }
+ else if (optimized_type == tls::TLSOPT_TO_IE)
+ {
+ // Create a GOT entry for the tp-relative offset.
+ Output_data_got<64, false>* got
+ = target->got_section(symtab, layout);
+ got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
+ target->rela_dyn_section(layout),
+ elfcpp::R_X86_64_TPOFF64);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC:
+ target->define_tls_base_symbol(symtab, layout);
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create reserved PLT and GOT entries for the resolver.
+ target->reserve_tlsdesc_entries(symtab, layout);
+
+ // Create a double GOT entry with an R_X86_64_TLSDESC reloc.
+ Output_data_got<64, false>* got
+ = target->got_section(symtab, layout);
+ got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC,
+ target->rela_dyn_section(layout),
+ elfcpp::R_X86_64_TLSDESC, 0);
+ }
+ else if (optimized_type == tls::TLSOPT_TO_IE)
+ {
+ // Create a GOT entry for the tp-relative offset.
+ Output_data_got<64, false>* got
+ = target->got_section(symtab, layout);
+ got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
+ target->rela_dyn_section(layout),
+ elfcpp::R_X86_64_TPOFF64);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+
+ case elfcpp::R_X86_64_TLSDESC_CALL:
+ break;
+
+ case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a GOT entry for the module index.
+ target->got_mod_index_entry(symtab, layout, object);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ break;
+
+ case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
+ layout->set_has_static_tls();
+ if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Create a GOT entry for the tp-relative offset.
+ Output_data_got<64, false>* got
+ = target->got_section(symtab, layout);
+ got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
+ target->rela_dyn_section(layout),
+ elfcpp::R_X86_64_TPOFF64);
+ }
+ else if (optimized_type != tls::TLSOPT_TO_LE)
+ unsupported_reloc_global(object, r_type, gsym);
+ break;
+
+ case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ layout->set_has_static_tls();
+ if (parameters->options().shared())
+ unsupported_reloc_local(object, r_type);
+ break;
+
+ default:
+ gold_unreachable();
+ }
+ }
+ break;
+
+ case elfcpp::R_X86_64_SIZE32:
+ case elfcpp::R_X86_64_SIZE64:
+ default:
+ gold_error(_("%s: unsupported reloc %u against global symbol %s"),
+ object->name().c_str(), r_type,
+ gsym->demangled_name().c_str());
+ break;
+ }
+}
+
+void
+Target_x86_64::gc_process_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols)
+{
+
+ if (sh_type == elfcpp::SHT_REL)
+ {
+ return;
+ }
+
+ gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
+ Target_x86_64::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_x86_64::scan_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols)
+{
+ if (sh_type == elfcpp::SHT_REL)
+ {
+ gold_error(_("%s: unsupported REL reloc section"),
+ object->name().c_str());
+ return;
+ }
+
+ gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
+ Target_x86_64::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_x86_64::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_RELA);
+ if (this->plt_->has_tlsdesc_entry())
+ {
+ unsigned int plt_offset = this->plt_->get_tlsdesc_plt_offset();
+ unsigned int got_offset = this->plt_->get_tlsdesc_got_offset();
+ this->got_->finalize_data_size();
+ odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_PLT,
+ this->plt_, plt_offset);
+ odyn->add_section_plus_offset(elfcpp::DT_TLSDESC_GOT,
+ this->got_, got_offset);
+ }
+ }
+
+ if (this->rela_dyn_ != NULL)
+ {
+ const Output_data* od = this->rela_dyn_;
+ odyn->add_section_address(elfcpp::DT_RELA, od);
+ odyn->add_section_size(elfcpp::DT_RELASZ, od);
+ odyn->add_constant(elfcpp::DT_RELAENT,
+ elfcpp::Elf_sizes<64>::rela_size);
+ }
+
+ if (!parameters->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->rela_dyn_section(layout));
+}
+
+// Perform a relocation.
+
+inline bool
+Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
+ Target_x86_64* target,
+ Output_section*,
+ size_t relnum,
+ const elfcpp::Rela<64, false>& rela,
+ unsigned int r_type,
+ const Sized_symbol<64>* gsym,
+ const Symbol_value<64>* psymval,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
+ section_size_type view_size)
+{
+ if (this->skip_call_tls_get_addr_)
+ {
+ if ((r_type != elfcpp::R_X86_64_PLT32
+ && r_type != elfcpp::R_X86_64_PC32)
+ || gsym == NULL
+ || strcmp(gsym->name(), "__tls_get_addr") != 0)
+ {
+ gold_error_at_location(relinfo, relnum, rela.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<64> symval;
+ if (gsym != NULL
+ && gsym->use_plt_offset(r_type == elfcpp::R_X86_64_PC64
+ || r_type == elfcpp::R_X86_64_PC32
+ || r_type == elfcpp::R_X86_64_PC16
+ || r_type == elfcpp::R_X86_64_PC8))
+ {
+ symval.set_output_value(target->plt_section()->address()
+ + gsym->plt_offset());
+ psymval = &symval;
+ }
+
+ const Sized_relobj<64, false>* object = relinfo->object;
+ const elfcpp::Elf_Xword addend = rela.get_r_addend();
+
+ // Get the GOT offset if needed.
+ // 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_X86_64_GOT32:
+ case elfcpp::R_X86_64_GOT64:
+ case elfcpp::R_X86_64_GOTPLT64:
+ case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPCREL64:
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
+ got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
+ }
+ else
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
+ 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_X86_64_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ break;
+
+ case elfcpp::R_X86_64_64:
+ Relocate_functions<64, false>::rela64(view, object, psymval, addend);
+ break;
+
+ case elfcpp::R_X86_64_PC64:
+ Relocate_functions<64, false>::pcrela64(view, object, psymval, addend,
+ address);
+ break;
+
+ case elfcpp::R_X86_64_32:
+ // FIXME: we need to verify that value + addend fits into 32 bits:
+ // uint64_t x = value + addend;
+ // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
+ // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
+ Relocate_functions<64, false>::rela32(view, object, psymval, addend);
+ break;
+
+ case elfcpp::R_X86_64_32S:
+ // FIXME: we need to verify that value + addend fits into 32 bits:
+ // int64_t x = value + addend; // note this quantity is signed!
+ // x == static_cast<int64_t>(static_cast<int32_t>(x))
+ Relocate_functions<64, false>::rela32(view, object, psymval, addend);
+ break;
+
+ case elfcpp::R_X86_64_PC32:
+ Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
+ address);
+ break;
+
+ case elfcpp::R_X86_64_16:
+ Relocate_functions<64, false>::rela16(view, object, psymval, addend);
+ break;
+
+ case elfcpp::R_X86_64_PC16:
+ Relocate_functions<64, false>::pcrela16(view, object, psymval, addend,
+ address);
+ break;
+
+ case elfcpp::R_X86_64_8:
+ Relocate_functions<64, false>::rela8(view, object, psymval, addend);
+ break;
+
+ case elfcpp::R_X86_64_PC8:
+ Relocate_functions<64, false>::pcrela8(view, object, psymval, addend,
+ address);
+ break;
+
+ case elfcpp::R_X86_64_PLT32:
+ gold_assert(gsym == NULL
+ || gsym->has_plt_offset()
+ || gsym->final_value_is_known()
+ || (gsym->is_defined()
+ && !gsym->is_from_dynobj()
+ && !gsym->is_preemptible()));
+ // Note: while this code looks the same as for R_X86_64_PC32, it
+ // behaves differently because psymval was set to point to
+ // the PLT entry, rather than the symbol, in Scan::global().
+ Relocate_functions<64, false>::pcrela32(view, object, psymval, addend,
+ address);
+ break;
+
+ case elfcpp::R_X86_64_PLTOFF64:
+ {
+ gold_assert(gsym);
+ gold_assert(gsym->has_plt_offset()
+ || gsym->final_value_is_known());
+ elfcpp::Elf_types<64>::Elf_Addr got_address;
+ got_address = target->got_section(NULL, NULL)->address();
+ Relocate_functions<64, false>::rela64(view, object, psymval,
+ addend - got_address);
+ }
+
+ case elfcpp::R_X86_64_GOT32:
+ gold_assert(have_got_offset);
+ Relocate_functions<64, false>::rela32(view, got_offset, addend);
+ break;
+
+ case elfcpp::R_X86_64_GOTPC32:
+ {
+ gold_assert(gsym);
+ elfcpp::Elf_types<64>::Elf_Addr value;
+ value = target->got_plt_section()->address();
+ Relocate_functions<64, false>::pcrela32(view, value, addend, address);
+ }
+ break;
+
+ case elfcpp::R_X86_64_GOT64:
+ // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
+ // Since we always add a PLT entry, this is equivalent.
+ case elfcpp::R_X86_64_GOTPLT64:
+ gold_assert(have_got_offset);
+ Relocate_functions<64, false>::rela64(view, got_offset, addend);
+ break;
+
+ case elfcpp::R_X86_64_GOTPC64:
+ {
+ gold_assert(gsym);
+ elfcpp::Elf_types<64>::Elf_Addr value;
+ value = target->got_plt_section()->address();
+ Relocate_functions<64, false>::pcrela64(view, value, addend, address);
+ }
+ break;
+
+ case elfcpp::R_X86_64_GOTOFF64:
+ {
+ elfcpp::Elf_types<64>::Elf_Addr value;
+ value = (psymval->value(object, 0)
+ - target->got_plt_section()->address());
+ Relocate_functions<64, false>::rela64(view, value, addend);
+ }
+ break;
+
+ case elfcpp::R_X86_64_GOTPCREL:
+ {
+ gold_assert(have_got_offset);
+ elfcpp::Elf_types<64>::Elf_Addr value;
+ value = target->got_plt_section()->address() + got_offset;
+ Relocate_functions<64, false>::pcrela32(view, value, addend, address);
+ }
+ break;
+
+ case elfcpp::R_X86_64_GOTPCREL64:
+ {
+ gold_assert(have_got_offset);
+ elfcpp::Elf_types<64>::Elf_Addr value;
+ value = target->got_plt_section()->address() + got_offset;
+ Relocate_functions<64, false>::pcrela64(view, value, addend, address);
+ }
+ break;
+
+ case elfcpp::R_X86_64_COPY:
+ case elfcpp::R_X86_64_GLOB_DAT:
+ case elfcpp::R_X86_64_JUMP_SLOT:
+ case elfcpp::R_X86_64_RELATIVE:
+ // These are outstanding tls relocs, which are unexpected when linking
+ case elfcpp::R_X86_64_TPOFF64:
+ case elfcpp::R_X86_64_DTPMOD64:
+ case elfcpp::R_X86_64_TLSDESC:
+ gold_error_at_location(relinfo, relnum, rela.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_X86_64_TLSGD: // Global-dynamic
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_X86_64_TLSDESC_CALL:
+ case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
+ case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ this->relocate_tls(relinfo, target, relnum, rela, r_type, gsym, psymval,
+ view, address, view_size);
+ break;
+
+ case elfcpp::R_X86_64_SIZE32:
+ case elfcpp::R_X86_64_SIZE64:
+ default:
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("unsupported reloc %u"),
+ r_type);
+ break;
+ }
+
+ return true;
+}
+
+// Perform a TLS relocation.
+
+inline void
+Target_x86_64::Relocate::relocate_tls(const Relocate_info<64, false>* relinfo,
+ Target_x86_64* target,
+ size_t relnum,
+ const elfcpp::Rela<64, false>& rela,
+ unsigned int r_type,
+ const Sized_symbol<64>* gsym,
+ const Symbol_value<64>* psymval,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
+ section_size_type view_size)
+{
+ Output_segment* tls_segment = relinfo->layout->tls_segment();
+
+ const Sized_relobj<64, false>* object = relinfo->object;
+ const elfcpp::Elf_Xword addend = rela.get_r_addend();
+
+ elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
+
+ const bool is_final = (gsym == NULL
+ ? !parameters->options().output_is_position_independent()
+ : gsym->final_value_is_known());
+ const tls::Tls_optimization optimized_type
+ = Target_x86_64::optimize_tls_reloc(is_final, r_type);
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_TLSGD: // Global-dynamic
+ this->saw_tls_block_reloc_ = true;
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ gold_assert(tls_segment != NULL);
+ this->tls_gd_to_le(relinfo, relnum, tls_segment,
+ rela, r_type, value, view,
+ view_size);
+ break;
+ }
+ else
+ {
+ unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
+ ? GOT_TYPE_TLS_OFFSET
+ : GOT_TYPE_TLS_PAIR);
+ unsigned int got_offset;
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(got_type));
+ got_offset = gsym->got_offset(got_type) - target->got_size();
+ }
+ else
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
+ gold_assert(object->local_has_got_offset(r_sym, got_type));
+ got_offset = (object->local_got_offset(r_sym, got_type)
+ - target->got_size());
+ }
+ if (optimized_type == tls::TLSOPT_TO_IE)
+ {
+ gold_assert(tls_segment != NULL);
+ value = target->got_plt_section()->address() + got_offset;
+ this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
+ value, view, address, view_size);
+ break;
+ }
+ else if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Relocate the field with the offset of the pair of GOT
+ // entries.
+ value = target->got_plt_section()->address() + got_offset;
+ Relocate_functions<64, false>::pcrela32(view, value, addend,
+ address);
+ break;
+ }
+ }
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("unsupported reloc %u"), r_type);
+ break;
+
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_X86_64_TLSDESC_CALL:
+ this->saw_tls_block_reloc_ = true;
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ gold_assert(tls_segment != NULL);
+ this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
+ rela, r_type, value, view,
+ view_size);
+ break;
+ }
+ else
+ {
+ unsigned int got_type = (optimized_type == tls::TLSOPT_TO_IE
+ ? GOT_TYPE_TLS_OFFSET
+ : GOT_TYPE_TLS_DESC);
+ unsigned int got_offset;
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(got_type));
+ got_offset = gsym->got_offset(got_type) - target->got_size();
+ }
+ else
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
+ gold_assert(object->local_has_got_offset(r_sym, got_type));
+ got_offset = (object->local_got_offset(r_sym, got_type)
+ - target->got_size());
+ }
+ if (optimized_type == tls::TLSOPT_TO_IE)
+ {
+ gold_assert(tls_segment != NULL);
+ value = target->got_plt_section()->address() + got_offset;
+ this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
+ rela, r_type, value, view, address,
+ view_size);
+ break;
+ }
+ else if (optimized_type == tls::TLSOPT_NONE)
+ {
+ if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
+ {
+ // Relocate the field with the offset of the pair of GOT
+ // entries.
+ value = target->got_plt_section()->address() + got_offset;
+ Relocate_functions<64, false>::pcrela32(view, value, addend,
+ address);
+ }
+ break;
+ }
+ }
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("unsupported reloc %u"), r_type);
+ break;
+
+ case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ this->saw_tls_block_reloc_ = true;
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ gold_assert(tls_segment != NULL);
+ this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
+ value, view, view_size);
+ break;
+ }
+ else if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Relocate the field with the offset of the GOT entry for
+ // the module index.
+ unsigned int got_offset;
+ got_offset = (target->got_mod_index_entry(NULL, NULL, NULL)
+ - target->got_size());
+ value = target->got_plt_section()->address() + got_offset;
+ Relocate_functions<64, false>::pcrela32(view, value, addend,
+ address);
+ break;
+ }
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("unsupported reloc %u"), r_type);
+ break;
+
+ case elfcpp::R_X86_64_DTPOFF32:
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ // This relocation type is used in debugging information.
+ // In that case we need to not optimize the value. If we
+ // haven't seen a TLSLD reloc, then we assume we should not
+ // optimize this reloc.
+ if (this->saw_tls_block_reloc_)
+ {
+ gold_assert(tls_segment != NULL);
+ value -= tls_segment->memsz();
+ }
+ }
+ Relocate_functions<64, false>::rela32(view, value, addend);
+ break;
+
+ case elfcpp::R_X86_64_DTPOFF64:
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ // See R_X86_64_DTPOFF32, just above, for why we test this.
+ if (this->saw_tls_block_reloc_)
+ {
+ gold_assert(tls_segment != NULL);
+ value -= tls_segment->memsz();
+ }
+ }
+ Relocate_functions<64, false>::rela64(view, value, addend);
+ break;
+
+ case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
+ if (optimized_type == tls::TLSOPT_TO_LE)
+ {
+ gold_assert(tls_segment != NULL);
+ Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
+ rela, r_type, value, view,
+ view_size);
+ break;
+ }
+ else if (optimized_type == tls::TLSOPT_NONE)
+ {
+ // Relocate the field with the offset of the GOT entry for
+ // the tp-relative offset of the symbol.
+ unsigned int got_offset;
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(GOT_TYPE_TLS_OFFSET));
+ got_offset = (gsym->got_offset(GOT_TYPE_TLS_OFFSET)
+ - target->got_size());
+ }
+ else
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
+ gold_assert(object->local_has_got_offset(r_sym,
+ GOT_TYPE_TLS_OFFSET));
+ got_offset = (object->local_got_offset(r_sym, GOT_TYPE_TLS_OFFSET)
+ - target->got_size());
+ }
+ value = target->got_plt_section()->address() + got_offset;
+ Relocate_functions<64, false>::pcrela32(view, value, addend, address);
+ break;
+ }
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("unsupported reloc type %u"),
+ r_type);
+ break;
+
+ case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ value -= tls_segment->memsz();
+ Relocate_functions<64, false>::rela32(view, value, addend);
+ break;
+ }
+}
+
+// Do a relocation in which we convert a TLS General-Dynamic to an
+// Initial-Exec.
+
+inline void
+Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo,
+ size_t relnum,
+ Output_segment*,
+ const elfcpp::Rela<64, false>& rela,
+ unsigned int,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
+ section_size_type view_size)
+{
+ // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
+ // .word 0x6666; rex64; call __tls_get_addr
+ // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
+
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
+
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
+
+ memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
+
+ const elfcpp::Elf_Xword addend = rela.get_r_addend();
+ Relocate_functions<64, false>::pcrela32(view + 8, value, addend - 8, address);
+
+ // The next reloc should be a PLT32 reloc against __tls_get_addr.
+ // We can skip it.
+ this->skip_call_tls_get_addr_ = true;
+}
+
+// Do a relocation in which we convert a TLS General-Dynamic to a
+// Local-Exec.
+
+inline void
+Target_x86_64::Relocate::tls_gd_to_le(const Relocate_info<64, false>* relinfo,
+ size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>& rela,
+ unsigned int,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size)
+{
+ // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
+ // .word 0x6666; rex64; call __tls_get_addr
+ // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
+
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -4);
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
+
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ (memcmp(view - 4, "\x66\x48\x8d\x3d", 4) == 0));
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
+
+ memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
+
+ value -= tls_segment->memsz();
+ Relocate_functions<64, false>::rela32(view + 8, value, 0);
+
+ // The next reloc should be a PLT32 reloc against __tls_get_addr.
+ // We can skip it.
+ this->skip_call_tls_get_addr_ = true;
+}
+
+// Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
+
+inline void
+Target_x86_64::Relocate::tls_desc_gd_to_ie(
+ const Relocate_info<64, false>* relinfo,
+ size_t relnum,
+ Output_segment*,
+ const elfcpp::Rela<64, false>& rela,
+ unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
+ section_size_type view_size)
+{
+ if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
+ {
+ // leaq foo@tlsdesc(%rip), %rax
+ // ==> movq foo@gottpoff(%rip), %rax
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
+ view[-2] = 0x8b;
+ const elfcpp::Elf_Xword addend = rela.get_r_addend();
+ Relocate_functions<64, false>::pcrela32(view, value, addend, address);
+ }
+ else
+ {
+ // call *foo@tlscall(%rax)
+ // ==> nop; nop
+ gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ view[0] == 0xff && view[1] == 0x10);
+ view[0] = 0x66;
+ view[1] = 0x90;
+ }
+}
+
+// Do a TLSDESC-style General-Dynamic to Local-Exec transition.
+
+inline void
+Target_x86_64::Relocate::tls_desc_gd_to_le(
+ const Relocate_info<64, false>* relinfo,
+ size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>& rela,
+ unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size)
+{
+ if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
+ {
+ // leaq foo@tlsdesc(%rip), %rax
+ // ==> movq foo@tpoff, %rax
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x05);
+ view[-2] = 0xc7;
+ view[-1] = 0xc0;
+ value -= tls_segment->memsz();
+ Relocate_functions<64, false>::rela32(view, value, 0);
+ }
+ else
+ {
+ // call *foo@tlscall(%rax)
+ // ==> nop; nop
+ gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ view[0] == 0xff && view[1] == 0x10);
+ view[0] = 0x66;
+ view[1] = 0x90;
+ }
+}
+
+inline void
+Target_x86_64::Relocate::tls_ld_to_le(const Relocate_info<64, false>* relinfo,
+ size_t relnum,
+ Output_segment*,
+ const elfcpp::Rela<64, false>& rela,
+ unsigned int,
+ elfcpp::Elf_types<64>::Elf_Addr,
+ unsigned char* view,
+ section_size_type view_size)
+{
+ // leaq foo@tlsld(%rip),%rdi; call __tls_get_addr@plt;
+ // ... leq foo@dtpoff(%rax),%reg
+ // ==> .word 0x6666; .byte 0x66; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
+
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
+
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
+
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
+
+ memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
+
+ // 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_x86_64::Relocate::tls_ie_to_le(const Relocate_info<64, false>* relinfo,
+ size_t relnum,
+ Output_segment* tls_segment,
+ const elfcpp::Rela<64, false>& rela,
+ unsigned int,
+ elfcpp::Elf_types<64>::Elf_Addr value,
+ unsigned char* view,
+ section_size_type view_size)
+{
+ // We need to examine the opcodes to figure out which instruction we
+ // are looking at.
+
+ // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
+ // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
+
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
+ tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 4);
+
+ unsigned char op1 = view[-3];
+ unsigned char op2 = view[-2];
+ unsigned char op3 = view[-1];
+ unsigned char reg = op3 >> 3;
+
+ if (op2 == 0x8b)
+ {
+ // movq
+ if (op1 == 0x4c)
+ view[-3] = 0x49;
+ view[-2] = 0xc7;
+ view[-1] = 0xc0 | reg;
+ }
+ else if (reg == 4)
+ {
+ // Special handling for %rsp.
+ if (op1 == 0x4c)
+ view[-3] = 0x49;
+ view[-2] = 0x81;
+ view[-1] = 0xc0 | reg;
+ }
+ else
+ {
+ // addq
+ if (op1 == 0x4c)
+ view[-3] = 0x4d;
+ view[-2] = 0x8d;
+ view[-1] = 0x80 | reg | (reg << 3);
+ }
+
+ value -= tls_segment->memsz();
+ Relocate_functions<64, false>::rela32(view, value, 0);
+}
+
+// Relocate section data.
+
+void
+Target_x86_64::relocate_section(
+ const Relocate_info<64, false>* relinfo,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
+ section_size_type view_size,
+ const Reloc_symbol_changes* reloc_symbol_changes)
+{
+ gold_assert(sh_type == elfcpp::SHT_RELA);
+
+ gold::relocate_section<64, false, Target_x86_64, elfcpp::SHT_RELA,
+ Target_x86_64::Relocate>(
+ relinfo,
+ this,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ view,
+ address,
+ view_size,
+ reloc_symbol_changes);
+}
+
+// Return the size of a relocation while scanning during a relocatable
+// link.
+
+unsigned int
+Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
+ unsigned int r_type,
+ Relobj* object)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ case elfcpp::R_X86_64_TLSGD: // Global-dynamic
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_X86_64_TLSDESC_CALL:
+ case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
+ case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ return 0;
+
+ case elfcpp::R_X86_64_64:
+ case elfcpp::R_X86_64_PC64:
+ case elfcpp::R_X86_64_GOTOFF64:
+ case elfcpp::R_X86_64_GOTPC64:
+ case elfcpp::R_X86_64_PLTOFF64:
+ case elfcpp::R_X86_64_GOT64:
+ case elfcpp::R_X86_64_GOTPCREL64:
+ case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPLT64:
+ return 8;
+
+ case elfcpp::R_X86_64_32:
+ case elfcpp::R_X86_64_32S:
+ case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PLT32:
+ case elfcpp::R_X86_64_GOTPC32:
+ case elfcpp::R_X86_64_GOT32:
+ return 4;
+
+ case elfcpp::R_X86_64_16:
+ case elfcpp::R_X86_64_PC16:
+ return 2;
+
+ case elfcpp::R_X86_64_8:
+ case elfcpp::R_X86_64_PC8:
+ return 1;
+
+ case elfcpp::R_X86_64_COPY:
+ case elfcpp::R_X86_64_GLOB_DAT:
+ case elfcpp::R_X86_64_JUMP_SLOT:
+ case elfcpp::R_X86_64_RELATIVE:
+ // These are outstanding tls relocs, which are unexpected when linking
+ case elfcpp::R_X86_64_TPOFF64:
+ case elfcpp::R_X86_64_DTPMOD64:
+ case elfcpp::R_X86_64_TLSDESC:
+ object->error(_("unexpected reloc %u in object file"), r_type);
+ return 0;
+
+ case elfcpp::R_X86_64_SIZE32:
+ case elfcpp::R_X86_64_SIZE64:
+ default:
+ object->error(_("unsupported reloc %u against local symbol"), r_type);
+ return 0;
+ }
+}
+
+// Scan the relocs during a relocatable link.
+
+void
+Target_x86_64::scan_relocatable_relocs(const General_options& options,
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols,
+ Relocatable_relocs* rr)
+{
+ gold_assert(sh_type == elfcpp::SHT_RELA);
+
+ typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
+ Relocatable_size_for_reloc> Scan_relocatable_relocs;
+
+ gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
+ 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_x86_64::relocate_for_relocatable(
+ const Relocate_info<64, false>* relinfo,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs* rr,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size)
+{
+ gold_assert(sh_type == elfcpp::SHT_RELA);
+
+ gold::relocate_for_relocatable<64, false, elfcpp::SHT_RELA>(
+ relinfo,
+ prelocs,
+ reloc_count,
+ output_section,
+ offset_in_output_section,
+ rr,
+ view,
+ view_address,
+ view_size,
+ reloc_view,
+ reloc_view_size);
+}
+
+// Return the value to use for a dynamic which requires special
+// 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_x86_64::do_dynsym_value(const Symbol* gsym) const
+{
+ gold_assert(gsym->is_from_dynobj() && gsym->has_plt_offset());
+ return this->plt_section()->address() + gsym->plt_offset();
+}
+
+// Return a string used to fill a code section with nops to take up
+// the specified length.
+
+std::string
+Target_x86_64::do_code_fill(section_size_type length) const
+{
+ if (length >= 16)
+ {
+ // Build a jmpq instruction to skip over the bytes.
+ unsigned char jmp[5];
+ jmp[0] = 0xe9;
+ elfcpp::Swap_unaligned<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] = { 0x0f, 0x1f, 0x00 }; // nop (%rax)
+ const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax)
+ const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1)
+ 0x00 };
+ const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1)
+ 0x00, 0x00 };
+ const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax)
+ 0x00, 0x00, 0x00 };
+ const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00 };
+ const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00,
+ 0x00 };
+ const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
+ 0x84, 0x00, 0x00, 0x00,
+ 0x00, 0x00 };
+ const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
+ 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00 };
+ const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
+ 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00 };
+ const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00,
+ 0x00 };
+ const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x66, 0x2e, 0x0f, 0x1f, // data16
+ 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00 };
+ const char nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x66, 0x66, 0x2e, 0x0f, // data16; data16
+ 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00 };
+
+ const char* nops[16] = {
+ NULL,
+ nop1, nop2, nop3, nop4, nop5, nop6, nop7,
+ nop8, nop9, nop10, nop11, nop12, nop13, nop14, nop15
+ };
+
+ return std::string(nops[length], length);
+}
+
+// FNOFFSET in section SHNDX in OBJECT is the start of a function
+// compiled with -fstack-split. The function calls non-stack-split
+// code. We have to change the function so that it always ensures
+// that it has enough stack space to run some random function.
+
+void
+Target_x86_64::do_calls_non_split(Relobj* object, unsigned int shndx,
+ section_offset_type fnoffset,
+ section_size_type fnsize,
+ unsigned char* view,
+ section_size_type view_size,
+ std::string* from,
+ std::string* to) const
+{
+ // The function starts with a comparison of the stack pointer and a
+ // field in the TCB. This is followed by a jump.
+
+ // cmp %fs:NN,%rsp
+ if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
+ && fnsize > 9)
+ {
+ // We will call __morestack if the carry flag is set after this
+ // comparison. We turn the comparison into an stc instruction
+ // and some nops.
+ view[fnoffset] = '\xf9';
+ this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
+ }
+ // lea NN(%rsp),%r10
+ else if (this->match_view(view, view_size, fnoffset, "\x4c\x8d\x94\x24", 4)
+ && fnsize > 8)
+ {
+ // This is loading an offset from the stack pointer for a
+ // comparison. The offset is negative, so we decrease the
+ // offset by the amount of space we need for the stack. This
+ // means we will avoid calling __morestack if there happens to
+ // be plenty of space on the stack already.
+ unsigned char* pval = view + fnoffset + 4;
+ uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
+ val -= parameters->options().split_stack_adjust_size();
+ elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
+ }
+ else
+ {
+ if (!object->has_no_split_stack())
+ object->error(_("failed to match split-stack sequence at "
+ "section %u offset %0zx"),
+ shndx, fnoffset);
+ return;
+ }
+
+ // We have to change the function so that it calls
+ // __morestack_non_split instead of __morestack. The former will
+ // allocate additional stack space.
+ *from = "__morestack";
+ *to = "__morestack_non_split";
+}
+
+// The selector for x86_64 object files.
+
+class Target_selector_x86_64 : public Target_selector_freebsd
+{
+public:
+ Target_selector_x86_64()
+ : Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
+ "elf64-x86-64-freebsd")
+ { }
+
+ Target*
+ do_instantiate_target()
+ { return new Target_x86_64(); }
+
+};
+
+Target_selector_x86_64 target_selector_x86_64;
+
+} // End anonymous namespace.
projects / msp430-binutils.git / blobdiff