// x86_64.cc -- x86_64 target support for gold.
-// Copyright 2006, 2007, Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <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 Library General Public License
-// as published by the Free Software Foundation; either version 2, or
+// This program is free software; you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
-// In addition to the permissions in the GNU Library General Public
-// License, the Free Software Foundation gives you unlimited
-// permission to link the compiled version of this file into
-// combinations with other programs, and to distribute those
-// combinations without any restriction coming from the use of this
-// file. (The Library Public License restrictions do apply in other
-// respects; for example, they cover modification of the file, and
-/// distribution when not linked into a combined executable.)
-
-// This program is distributed in the hope that it will be useful, but
-// WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
-// Library General Public License for more details.
-
-// You should have received a copy of the GNU Library General Public
-// License along with this program; if not, write to the Free Software
-// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA
-// 02110-1301, USA.
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with this program; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
+// MA 02110-1301, USA.
#include "gold.h"
#include "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
{
// http://people.redhat.com/drepper/tls.pdf
// http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
-class Target_x86_64 : public Sized_target<64, false>
+class Target_x86_64 : public Target_freebsd<64, false>
{
public:
// In the x86_64 ABI (p 68), it says "The AMD64 ABI architectures
typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
Target_x86_64()
- : Sized_target<64, false>(&x86_64_info),
+ : Target_freebsd<64, false>(&x86_64_info),
got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL),
- copy_relocs_(NULL), dynbss_(NULL), got_mod_index_offset_(-1U)
+ 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
- scan_relocs(const General_options& options,
- Symbol_table* symtab,
+ gc_process_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols);
+
+ // Scan the relocations to look for symbol adjustments.
+ void
+ scan_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<64, false>* object,
unsigned int data_shndx,
// Finalize the sections.
void
- do_finalize_sections(Layout*);
+ do_finalize_sections(Layout*, const Input_objects*);
// Return the value to use for a dynamic which requires special
// treatment.
bool needs_special_offset_handling,
unsigned char* view,
elfcpp::Elf_types<64>::Elf_Addr view_address,
- section_size_type view_size);
+ section_size_type view_size,
+ const Reloc_symbol_changes*);
+
+ // Scan the relocs during a relocatable link.
+ void
+ scan_relocatable_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols,
+ Relocatable_relocs*);
+
+ // Relocate a section during a relocatable link.
+ void
+ relocate_for_relocatable(const Relocate_info<64, false>*,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs*,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size);
// Return a string used to fill a code section with nops.
std::string
- do_code_fill(section_size_type length);
+ do_code_fill(section_size_type length) const;
// Return whether SYM is defined by the ABI.
bool
- do_is_defined_by_abi(Symbol* sym) const
+ do_is_defined_by_abi(const Symbol* sym) const
{ return strcmp(sym->name(), "__tls_get_addr") == 0; }
+ // 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()
private:
// The class which scans relocations.
- struct Scan
+ class Scan
{
+ public:
+ Scan()
+ : issued_non_pic_error_(false)
+ { }
+
inline void
- local(const General_options& options, Symbol_table* symtab,
- Layout* layout, Target_x86_64* target,
+ local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
Sized_relobj<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Sym<64, false>& lsym);
inline void
- global(const General_options& options, Symbol_table* symtab,
- Layout* layout, Target_x86_64* target,
+ global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
Sized_relobj<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
Symbol* gsym);
+ private:
static void
unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
static void
unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type,
Symbol*);
+
+ void
+ check_non_pic(Relobj*, unsigned int r_type);
+
+ // Whether we have issued an error about a non-PIC compilation.
+ bool issued_non_pic_error_;
};
// The class which implements relocation.
{
public:
Relocate()
- : skip_call_tls_get_addr_(false)
+ : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
{ }
~Relocate()
// Do a relocation. Return false if the caller should not issue
// any warnings about this relocation.
inline bool
- relocate(const Relocate_info<64, false>*, Target_x86_64*, size_t relnum,
- const elfcpp::Rela<64, false>&,
+ relocate(const Relocate_info<64, false>*, Target_x86_64*, Output_section*,
+ size_t relnum, const elfcpp::Rela<64, false>&,
unsigned int r_type, const Sized_symbol<64>*,
const Symbol_value<64>*,
unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
unsigned char*, elfcpp::Elf_types<64>::Elf_Addr,
section_size_type);
- // Do a TLS General-Dynamic to Local-Exec transition.
+ // 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.
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,
// 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
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,
Reloc_section*
rela_dyn_section(Layout*);
- // Return true if the symbol may need a COPY relocation.
- // References from an executable object to non-function symbols
- // defined in a dynamic object may need a COPY relocation.
- bool
- may_need_copy_reloc(Symbol* gsym)
+ // 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)
{
- return (!parameters->output_is_shared()
- && gsym->is_from_dynobj()
- && gsym->type() != elfcpp::STT_FUNC);
+ this->copy_relocs_.copy_reloc(symtab, layout,
+ symtab->get_sized_symbol<64>(sym),
+ object, shndx, output_section,
+ reloc, this->rela_dyn_section(layout));
}
- // Copy a relocation against a global symbol.
- void
- copy_reloc(const General_options*, Symbol_table*, Layout*,
- Sized_relobj<64, false>*, unsigned int,
- Output_section*, Symbol*, const elfcpp::Rela<64, false>&);
-
// 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.
// The dynamic reloc section.
Reloc_section* rela_dyn_;
// Relocs saved to avoid a COPY reloc.
- Copy_relocs<64, false>* copy_relocs_;
+ 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;
+ // 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 =
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
- 0x1000 // common_pagesize
+ 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>*
this->got_ = new Output_data_got<64, false>();
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_);
+ Output_section* os;
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_, false);
+ os->set_is_relro();
// The old GNU linker creates a .got.plt section. We just
// create another set of data in the .got section. Note that we
// always create a PLT if we create a GOT, although the PLT
// might be empty.
- this->got_plt_ = new Output_data_space(8);
- layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
- elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
- this->got_plt_);
+ this->got_plt_ = new Output_data_space(8, "** GOT PLT");
+ os = layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_plt_, false);
+ os->set_is_relro();
// The first three entries are reserved.
this->got_plt_->set_current_data_size(3 * 8);
// Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
- symtab->define_in_output_data(this, "_GLOBAL_OFFSET_TABLE_", NULL,
+ symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
this->got_plt_,
0, 0, elfcpp::STT_OBJECT,
elfcpp::STB_LOCAL,
if (this->rela_dyn_ == NULL)
{
gold_assert(layout != NULL);
- this->rela_dyn_ = new Reloc_section();
+ this->rela_dyn_ = new Reloc_section(parameters->options().combreloc());
layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
- elfcpp::SHF_ALLOC, this->rela_dyn_);
+ elfcpp::SHF_ALLOC, this->rela_dyn_, true);
}
return this->rela_dyn_;
}
public:
typedef Output_data_reloc<elfcpp::SHT_RELA, true, 64, false> Reloc_section;
- Output_data_plt_x86_64(Layout*, Output_data_space*);
+ Output_data_plt_x86_64(Layout*, Output_data_got<64, false>*,
+ Output_data_space*);
// Add an entry to the PLT.
void
add_entry(Symbol* gsym);
+ // Add the reserved TLSDESC_PLT entry to the PLT.
+ void
+ reserve_tlsdesc_entry(unsigned int got_offset)
+ { this->tlsdesc_got_offset_ = got_offset; }
+
+ // Return true if a TLSDESC_PLT entry has been reserved.
+ bool
+ has_tlsdesc_entry() const
+ { return this->tlsdesc_got_offset_ != -1U; }
+
+ // Return the GOT offset for the reserved TLSDESC_PLT entry.
+ unsigned int
+ get_tlsdesc_got_offset() const
+ { return this->tlsdesc_got_offset_; }
+
+ // Return the offset of the reserved TLSDESC_PLT entry.
+ unsigned int
+ get_tlsdesc_plt_offset() const
+ { return (this->count_ + 1) * plt_entry_size; }
+
// Return the .rel.plt section data.
const Reloc_section*
rel_plt() const
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;
// 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()
- { this->set_data_size((this->count_ + 1) * plt_entry_size); }
+ set_final_data_size();
// Write out the PLT data.
void
// 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,
// 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_plt_(got_plt), count_(0)
+ : Output_section_data(8), got_(got), got_plt_(got_plt), count_(0),
+ tlsdesc_got_offset_(-1U)
{
- this->rel_ = new Reloc_section();
+ this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
- elfcpp::SHF_ALLOC, this->rel_);
+ elfcpp::SHF_ALLOC, this->rel_, true);
}
void
Output_data_plt_x86_64::do_adjust_output_section(Output_section* os)
{
- // UnixWare sets the entsize of .plt to 4, and so does the old GNU
- // linker, and so do we.
- os->set_entsize(4);
+ os->set_entsize(plt_entry_size);
}
// Add an entry to the PLT.
// 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] =
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.
unsigned char* pov = oview;
- elfcpp::Elf_types<32>::Elf_Addr plt_address = this->address();
- elfcpp::Elf_types<32>::Elf_Addr got_address = this->got_plt_->address();
+ // The base address of the .plt section.
+ elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
+ // The base address of the .got section.
+ elfcpp::Elf_types<64>::Elf_Addr got_base = this->got_->address();
+ // The base address of the PLT portion of the .got section,
+ // which is where the GOT pointer will point, and where the
+ // three reserved GOT entries are located.
+ elfcpp::Elf_types<64>::Elf_Addr got_address = this->got_plt_->address();
memcpy(pov, first_plt_entry, plt_entry_size);
// 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));
+ 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;
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(got_file_offset, got_size, got_view);
}
-// Create a PLT entry for a global symbol.
+// Create the PLT section.
void
-Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
- Symbol* gsym)
+Target_x86_64::make_plt_section(Symbol_table* symtab, Layout* layout)
{
- if (gsym->has_plt_offset())
- return;
-
if (this->plt_ == NULL)
{
// Create the GOT sections first.
this->got_section(symtab, layout);
- this->plt_ = new Output_data_plt_x86_64(layout, this->got_plt_);
+ this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
+ this->got_plt_);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
- this->plt_);
+ this->plt_, false);
}
+}
+
+// Create a PLT entry for a global symbol.
+
+void
+Target_x86_64::make_plt_entry(Symbol_table* symtab, Layout* layout,
+ Symbol* gsym)
+{
+ if (gsym->has_plt_offset())
+ return;
+
+ if (this->plt_ == NULL)
+ this->make_plt_section(symtab, layout);
this->plt_->add_entry(gsym);
}
+// 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
return this->got_mod_index_offset_;
}
-// Handle a relocation against a non-function symbol defined in a
-// dynamic object. The traditional way to handle this is to generate
-// a COPY relocation to copy the variable at runtime from the shared
-// object into the executable's data segment. However, this is
-// undesirable in general, as if the size of the object changes in the
-// dynamic object, the executable will no longer work correctly. If
-// this relocation is in a writable section, then we can create a
-// dynamic reloc and the dynamic linker will resolve it to the correct
-// address at runtime. However, we do not want do that if the
-// relocation is in a read-only section, as it would prevent the
-// readonly segment from being shared. And if we have to eventually
-// generate a COPY reloc, then any dynamic relocations will be
-// useless. So this means that if this is a writable section, we need
-// to save the relocation until we see whether we have to create a
-// COPY relocation for this symbol for any other relocation.
-
-void
-Target_x86_64::copy_reloc(const General_options* options,
- Symbol_table* symtab,
- Layout* layout,
- Sized_relobj<64, false>* object,
- unsigned int data_shndx,
- Output_section* output_section,
- Symbol* gsym,
- const elfcpp::Rela<64, false>& rela)
-{
- Sized_symbol<64>* ssym;
- ssym = symtab->get_sized_symbol SELECT_SIZE_NAME(64) (gsym
- SELECT_SIZE(64));
-
- if (!Copy_relocs<64, false>::need_copy_reloc(options, object,
- data_shndx, ssym))
- {
- // So far we do not need a COPY reloc. Save this relocation.
- // If it turns out that we never need a COPY reloc for this
- // symbol, then we will emit the relocation.
- if (this->copy_relocs_ == NULL)
- this->copy_relocs_ = new Copy_relocs<64, false>();
- this->copy_relocs_->save(ssym, object, data_shndx, output_section, rela);
- }
- else
- {
- // Allocate space for this symbol in the .bss section.
-
- elfcpp::Elf_types<64>::Elf_WXword symsize = ssym->symsize();
-
- // There is no defined way to determine the required alignment
- // of the symbol. We pick the alignment based on the size. We
- // set an arbitrary maximum of 256.
- unsigned int align;
- for (align = 1; align < 512; align <<= 1)
- if ((symsize & align) != 0)
- break;
-
- if (this->dynbss_ == NULL)
- {
- this->dynbss_ = new Output_data_space(align);
- layout->add_output_section_data(".bss",
- elfcpp::SHT_NOBITS,
- (elfcpp::SHF_ALLOC
- | elfcpp::SHF_WRITE),
- this->dynbss_);
- }
-
- Output_data_space* dynbss = this->dynbss_;
-
- if (align > dynbss->addralign())
- dynbss->set_space_alignment(align);
-
- section_size_type dynbss_size = dynbss->current_data_size();
- dynbss_size = align_address(dynbss_size, align);
- section_size_type offset = dynbss_size;
- dynbss->set_current_data_size(dynbss_size + symsize);
-
- symtab->define_with_copy_reloc(this, ssym, dynbss, offset);
-
- // Add the COPY reloc.
- Reloc_section* rela_dyn = this->rela_dyn_section(layout);
- rela_dyn->add_global(ssym, elfcpp::R_X86_64_COPY, dynbss, offset, 0);
- }
-}
-
-
// 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.
{
// If we are generating a shared library, then we can't do anything
// in the linker.
- if (parameters->output_is_shared())
+ if (parameters->options().shared())
return tls::TLSOPT_NONE;
switch (r_type)
object->name().c_str(), r_type);
}
+// We are about to emit a dynamic relocation of type R_TYPE. If the
+// dynamic linker does not support it, issue an error. The GNU linker
+// only issues a non-PIC error for an allocated read-only section.
+// Here we know the section is allocated, but we don't know that it is
+// read-only. But we check for all the relocation types which the
+// glibc dynamic linker supports, so it seems appropriate to issue an
+// error even if the section is not read-only.
+
+void
+Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type)
+{
+ switch (r_type)
+ {
+ // These are the relocation types supported by glibc for x86_64.
+ case elfcpp::R_X86_64_RELATIVE:
+ case elfcpp::R_X86_64_GLOB_DAT:
+ case elfcpp::R_X86_64_JUMP_SLOT:
+ case elfcpp::R_X86_64_DTPMOD64:
+ case elfcpp::R_X86_64_DTPOFF64:
+ case elfcpp::R_X86_64_TPOFF64:
+ case elfcpp::R_X86_64_64:
+ case elfcpp::R_X86_64_32:
+ case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_COPY:
+ return;
+
+ default:
+ // This prevents us from issuing more than one error per reloc
+ // section. But we can still wind up issuing more than one
+ // error per object file.
+ if (this->issued_non_pic_error_)
+ return;
+ gold_assert(parameters->options().output_is_position_independent());
+ object->error(_("requires unsupported dynamic reloc; "
+ "recompile with -fPIC"));
+ this->issued_non_pic_error_ = true;
+ return;
+
+ case elfcpp::R_X86_64_NONE:
+ gold_unreachable();
+ }
+}
+
// Scan a relocation for a local symbol.
inline void
-Target_x86_64::Scan::local(const General_options&,
- Symbol_table* symtab,
+Target_x86_64::Scan::local(Symbol_table* symtab,
Layout* layout,
Target_x86_64* target,
Sized_relobj<64, false>* object,
case elfcpp::R_X86_64_64:
// If building a shared library (or a position-independent
- // executable), we need to create a dynamic relocation for
- // this location. The relocation applied at link time will
- // apply the link-time value, so we flag the location with
- // an R_386_RELATIVE relocation so the dynamic loader can
+ // executable), we need to create a dynamic relocation for this
+ // location. The relocation applied at link time will apply the
+ // link-time value, so we flag the location with an
+ // R_X86_64_RELATIVE relocation so the dynamic loader can
// relocate it easily.
- if (parameters->output_is_position_independent())
+ 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);
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. The relocation applied at link time will
- // apply the link-time value, so we flag the location with
- // an R_386_RELATIVE relocation so the dynamic loader can
- // relocate it easily.
- if (parameters->output_is_position_independent())
+ // 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());
- rela_dyn->add_local(object, r_sym, r_type, output_section,
- data_shndx, reloc.get_r_offset(),
- reloc.get_r_addend());
+ 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;
// The symbol requires a GOT entry.
Output_data_got<64, false>* got = target->got_section(symtab, layout);
unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
- if (got->add_local(object, r_sym))
+ if (got->add_local(object, r_sym, GOT_TYPE_STANDARD))
{
// If we are generating a shared object, we need to add a
// dynamic relocation for this symbol's GOT entry.
- if (parameters->output_is_position_independent())
+ 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),
- 0);
+ 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
- rela_dyn->add_local(object, r_sym, r_type,
- got, object->local_got_offset(r_sym), 0);
+ {
+ 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
case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
case elfcpp::R_X86_64_TPOFF32: // Local-exec
{
- bool output_is_shared = parameters->output_is_shared();
+ bool output_is_shared = parameters->options().shared();
const tls::Tls_optimization optimized_type
= Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
switch (r_type)
Output_data_got<64, false>* got
= target->got_section(symtab, layout);
unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
- got->add_local_tls_with_rela(object, r_sym,
- lsym.get_st_shndx(), true,
- target->rela_dyn_section(layout),
- elfcpp::R_X86_64_DTPMOD64);
+ 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:
- case elfcpp::R_X86_64_TLSDESC_CALL:
- // FIXME: If not relaxing to LE, we need to generate
- // a GOT entry with a R_x86_64_TLSDESC reloc.
- if (optimized_type != tls::TLSOPT_TO_LE)
+ 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)
{
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->add_local_with_rela(object, r_sym, GOT_TYPE_TLS_OFFSET,
target->rela_dyn_section(layout),
elfcpp::R_X86_64_TPOFF64);
}
// Scan a relocation for a global symbol.
inline void
-Target_x86_64::Scan::global(const General_options& options,
- Symbol_table* symtab,
+Target_x86_64::Scan::global(Symbol_table* symtab,
Layout* layout,
Target_x86_64* target,
Sized_relobj<64, false>* object,
// 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())
+ if (gsym->is_from_dynobj() && !parameters->options().shared())
gsym->set_needs_dynsym_value();
}
// Make a dynamic relocation if necessary.
- if (gsym->needs_dynamic_reloc(true, false))
+ if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
{
- if (target->may_need_copy_reloc(gsym))
+ if (gsym->may_need_copy_reloc())
{
- target->copy_reloc(&options, symtab, layout, object,
+ target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
}
else if (r_type == elfcpp::R_X86_64_64
}
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(),
if (gsym->needs_plt_entry())
target->make_plt_entry(symtab, layout, gsym);
// Make a dynamic relocation if necessary.
- bool is_function_call = (gsym->type() == elfcpp::STT_FUNC);
- if (gsym->needs_dynamic_reloc(false, is_function_call))
+ 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))
+ if (gsym->may_need_copy_reloc())
{
- target->copy_reloc(&options, symtab, layout, object,
+ 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(),
// 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->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_preemptible())
- got->add_global_with_rela(gsym, rela_dyn,
+ 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))
- rela_dyn->add_global_relative(gsym,
- elfcpp::R_X86_64_RELATIVE,
- got, gsym->got_offset(), 0);
+ if (got->add_global(gsym, GOT_TYPE_STANDARD))
+ rela_dyn->add_global_relative(
+ gsym, elfcpp::R_X86_64_RELATIVE, got,
+ gsym->got_offset(GOT_TYPE_STANDARD), 0);
}
}
// For GOTPLT64, we also need a PLT entry (but only if the
// dtv-relative offset.
Output_data_got<64, false>* got
= target->got_section(symtab, layout);
- got->add_global_tls_with_rela(gsym,
- target->rela_dyn_section(layout),
- elfcpp::R_X86_64_DTPMOD64,
- elfcpp::R_X86_64_DTPOFF64);
+ 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->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
target->rela_dyn_section(layout),
elfcpp::R_X86_64_TPOFF64);
}
break;
case elfcpp::R_X86_64_GOTPC32_TLSDESC:
- case elfcpp::R_X86_64_TLSDESC_CALL:
- // FIXME: If not relaxing to LE, we need to generate
- // DTPMOD64 and DTPOFF64, or TLSDESC, relocs.
- if (optimized_type != tls::TLSOPT_TO_LE)
+ 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 tp-relative offset.
Output_data_got<64, false>* got
= target->got_section(symtab, layout);
- got->add_global_with_rela(gsym,
+ got->add_global_with_rela(gsym, GOT_TYPE_TLS_OFFSET,
target->rela_dyn_section(layout),
elfcpp::R_X86_64_TPOFF64);
}
case elfcpp::R_X86_64_TPOFF32: // Local-exec
layout->set_has_static_tls();
- if (parameters->output_is_shared())
+ if (parameters->options().shared())
unsupported_reloc_local(object, r_type);
break;
}
}
+void
+Target_x86_64::gc_process_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols)
+{
+
+ if (sh_type == elfcpp::SHT_REL)
+ {
+ return;
+ }
+
+ gold::gc_process_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
+ Target_x86_64::Scan>(
+ symtab,
+ layout,
+ this,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols);
+
+}
// Scan relocations for a section.
void
-Target_x86_64::scan_relocs(const General_options& options,
- Symbol_table* symtab,
+Target_x86_64::scan_relocs(Symbol_table* symtab,
Layout* layout,
Sized_relobj<64, false>* object,
unsigned int data_shndx,
gold::scan_relocs<64, false, Target_x86_64, elfcpp::SHT_RELA,
Target_x86_64::Scan>(
- options,
symtab,
layout,
this,
// Finalize the sections.
void
-Target_x86_64::do_finalize_sections(Layout* layout)
+Target_x86_64::do_finalize_sections(Layout* layout, const Input_objects*)
{
// Fill in some more dynamic tags.
Output_data_dynamic* const odyn = layout->dynamic_data();
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)
elfcpp::Elf_sizes<64>::rela_size);
}
- if (!parameters->output_is_shared())
+ if (!parameters->options().shared())
{
// The value of the DT_DEBUG tag is filled in by the dynamic
// linker at run time, and used by the debugger.
// Emit any relocs we saved in an attempt to avoid generating COPY
// relocs.
- if (this->copy_relocs_ == NULL)
- return;
- if (this->copy_relocs_->any_to_emit())
- {
- Reloc_section* rela_dyn = this->rela_dyn_section(layout);
- this->copy_relocs_->emit(rela_dyn);
- }
- delete this->copy_relocs_;
- this->copy_relocs_ = NULL;
+ if (this->copy_relocs_.any_saved_relocs())
+ this->copy_relocs_.emit(this->rela_dyn_section(layout));
}
// Perform a relocation.
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,
{
if (this->skip_call_tls_get_addr_)
{
- if (r_type != elfcpp::R_X86_64_PLT32
+ if ((r_type != elfcpp::R_X86_64_PLT32
+ && r_type != elfcpp::R_X86_64_PC32)
|| gsym == NULL
|| strcmp(gsym->name(), "__tls_get_addr") != 0)
{
// Pick the value to use for symbols defined in shared objects.
Symbol_value<64> symval;
if (gsym != NULL
- && (gsym->is_from_dynobj()
- || (parameters->output_is_shared()
- && gsym->is_preemptible()))
- && gsym->has_plt_offset())
+ && 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());
case elfcpp::R_X86_64_GOTPCREL64:
if (gsym != NULL)
{
- gold_assert(gsym->has_got_offset());
- got_offset = gsym->got_offset() - target->got_size();
+ gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
+ got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
}
else
{
unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
- gold_assert(object->local_has_got_offset(r_sym));
- got_offset = object->local_got_offset(r_sym) - target->got_size();
+ gold_assert(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;
case elfcpp::R_X86_64_PLT32:
gold_assert(gsym == NULL
|| gsym->has_plt_offset()
- || gsym->final_value_is_known());
+ || 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().
elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
const bool is_final = (gsym == NULL
- ? !parameters->output_is_position_independent()
+ ? !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
- 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);
}
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_tls_got_offset(true));
- got_offset = gsym->tls_got_offset(true) - target->got_size();
+ 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_tls_got_offset(r_sym, true));
- got_offset = (object->local_tls_got_offset(r_sym, true)
+ 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,
- got_offset, view, view_size);
+ value, view, address, view_size);
break;
}
else if (optimized_type == tls::TLSOPT_NONE)
_("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);
break;
case elfcpp::R_X86_64_DTPOFF32:
- gold_assert(tls_segment != NULL);
if (optimized_type == tls::TLSOPT_TO_LE)
- value -= tls_segment->memsz();
- Relocate_functions<64, false>::rela32(view, value, 0);
+ {
+ // 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:
- gold_assert(tls_segment != NULL);
if (optimized_type == tls::TLSOPT_TO_LE)
- value -= tls_segment->memsz();
- Relocate_functions<64, false>::rela64(view, value, 0);
+ {
+ // 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
unsigned int got_offset;
if (gsym != NULL)
{
- gold_assert(gsym->has_got_offset());
- got_offset = gsym->got_offset() - target->got_size();
+ 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_offset = (object->local_got_offset(r_sym)
+ 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;
case elfcpp::R_X86_64_TPOFF32: // Local-exec
value -= tls_segment->memsz();
- Relocate_functions<64, false>::rela32(view, value, 0);
+ Relocate_functions<64, false>::rela32(view, value, addend);
break;
}
}
inline void
Target_x86_64::Relocate::tls_gd_to_ie(const Relocate_info<64, false>* relinfo,
size_t relnum,
- Output_segment* tls_segment,
+ Output_segment*,
const elfcpp::Rela<64, false>& rela,
unsigned int,
elfcpp::Elf_types<64>::Elf_Addr value,
unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
section_size_type view_size)
{
// .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x03\x05\0\0\0\0", 16);
- value -= tls_segment->memsz();
- Relocate_functions<64, false>::rela32(view + 8, value, 0);
+ 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 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,
// 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)
+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);
needs_special_offset_handling,
view,
address,
- view_size);
+ view_size,
+ reloc_symbol_changes);
+}
+
+// Return the size of a relocation while scanning during a relocatable
+// link.
+
+unsigned int
+Target_x86_64::Relocatable_size_for_reloc::get_size_for_reloc(
+ unsigned int r_type,
+ Relobj* object)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_NONE:
+ case elfcpp::R_386_GNU_VTINHERIT:
+ case elfcpp::R_386_GNU_VTENTRY:
+ case elfcpp::R_X86_64_TLSGD: // Global-dynamic
+ case elfcpp::R_X86_64_GOTPC32_TLSDESC: // Global-dynamic (from ~oliva url)
+ case elfcpp::R_X86_64_TLSDESC_CALL:
+ case elfcpp::R_X86_64_TLSLD: // Local-dynamic
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
+ case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ return 0;
+
+ case elfcpp::R_X86_64_64:
+ case elfcpp::R_X86_64_PC64:
+ case elfcpp::R_X86_64_GOTOFF64:
+ case elfcpp::R_X86_64_GOTPC64:
+ case elfcpp::R_X86_64_PLTOFF64:
+ case elfcpp::R_X86_64_GOT64:
+ case elfcpp::R_X86_64_GOTPCREL64:
+ case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPLT64:
+ return 8;
+
+ case elfcpp::R_X86_64_32:
+ case elfcpp::R_X86_64_32S:
+ case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PLT32:
+ case elfcpp::R_X86_64_GOTPC32:
+ case elfcpp::R_X86_64_GOT32:
+ return 4;
+
+ case elfcpp::R_X86_64_16:
+ case elfcpp::R_X86_64_PC16:
+ return 2;
+
+ case elfcpp::R_X86_64_8:
+ case elfcpp::R_X86_64_PC8:
+ return 1;
+
+ case elfcpp::R_X86_64_COPY:
+ case elfcpp::R_X86_64_GLOB_DAT:
+ case elfcpp::R_X86_64_JUMP_SLOT:
+ case elfcpp::R_X86_64_RELATIVE:
+ // These are outstanding tls relocs, which are unexpected when linking
+ case elfcpp::R_X86_64_TPOFF64:
+ case elfcpp::R_X86_64_DTPMOD64:
+ case elfcpp::R_X86_64_TLSDESC:
+ object->error(_("unexpected reloc %u in object file"), r_type);
+ return 0;
+
+ case elfcpp::R_X86_64_SIZE32:
+ case elfcpp::R_X86_64_SIZE64:
+ default:
+ object->error(_("unsupported reloc %u against local symbol"), r_type);
+ return 0;
+ }
+}
+
+// Scan the relocs during a relocatable link.
+
+void
+Target_x86_64::scan_relocatable_relocs(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj<64, false>* object,
+ unsigned int data_shndx,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ bool needs_special_offset_handling,
+ size_t local_symbol_count,
+ const unsigned char* plocal_symbols,
+ Relocatable_relocs* rr)
+{
+ gold_assert(sh_type == elfcpp::SHT_RELA);
+
+ typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
+ Relocatable_size_for_reloc> Scan_relocatable_relocs;
+
+ gold::scan_relocatable_relocs<64, false, elfcpp::SHT_RELA,
+ Scan_relocatable_relocs>(
+ symtab,
+ layout,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols,
+ rr);
+}
+
+// Relocate a section during a relocatable link.
+
+void
+Target_x86_64::relocate_for_relocatable(
+ const Relocate_info<64, false>* relinfo,
+ unsigned int sh_type,
+ const unsigned char* prelocs,
+ size_t reloc_count,
+ Output_section* output_section,
+ off_t offset_in_output_section,
+ const Relocatable_relocs* rr,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr view_address,
+ section_size_type view_size,
+ unsigned char* reloc_view,
+ section_size_type reloc_view_size)
+{
+ gold_assert(sh_type == elfcpp::SHT_RELA);
+
+ gold::relocate_for_relocatable<64, false, elfcpp::SHT_RELA>(
+ relinfo,
+ prelocs,
+ reloc_count,
+ output_section,
+ offset_in_output_section,
+ rr,
+ view,
+ view_address,
+ view_size,
+ reloc_view,
+ reloc_view_size);
}
// Return the value to use for a dynamic which requires special
// the specified length.
std::string
-Target_x86_64::do_code_fill(section_size_type length)
+Target_x86_64::do_code_fill(section_size_type length) const
{
if (length >= 16)
{
// Build a jmpq instruction to skip over the bytes.
unsigned char jmp[5];
jmp[0] = 0xe9;
- elfcpp::Swap_unaligned<64, false>::writeval(jmp + 1, length - 5);
+ elfcpp::Swap_unaligned<32, false>::writeval(jmp + 1, length - 5);
return (std::string(reinterpret_cast<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
+ const char nop3[3] = { 0x0f, 0x1f, 0x00 }; // nop (%rax)
+ const char nop4[4] = { 0x0f, 0x1f, 0x40, 0x00}; // nop 0(%rax)
+ const char nop5[5] = { 0x0f, 0x1f, 0x44, 0x00, // nop 0(%rax,%rax,1)
+ 0x00 };
+ const char nop6[6] = { 0x66, 0x0f, 0x1f, 0x44, // nopw 0(%rax,%rax,1)
0x00, 0x00 };
- const char nop7[7] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
+ const char nop7[7] = { 0x0f, 0x1f, 0x80, 0x00, // nopl 0L(%rax)
0x00, 0x00, 0x00 };
- const char nop8[8] = { 0x90, 0x8d, 0xb4, 0x26, // nop
- 0x00, 0x00, 0x00, 0x00 }; // leal 0L(%esi,1),%esi
- const char nop9[9] = { 0x89, 0xf6, 0x8d, 0xbc, // movl %esi,%esi
- 0x27, 0x00, 0x00, 0x00, // leal 0L(%edi,1),%edi
+ const char nop8[8] = { 0x0f, 0x1f, 0x84, 0x00, // nopl 0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00 };
+ const char nop9[9] = { 0x66, 0x0f, 0x1f, 0x84, // nopw 0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00,
0x00 };
- const char nop10[10] = { 0x8d, 0x76, 0x00, 0x8d, // leal 0(%esi),%esi
- 0xbc, 0x27, 0x00, 0x00, // leal 0L(%edi,1),%edi
+ const char nop10[10] = { 0x66, 0x2e, 0x0f, 0x1f, // nopw %cs:0L(%rax,%rax,1)
+ 0x84, 0x00, 0x00, 0x00,
0x00, 0x00 };
- const char nop11[11] = { 0x8d, 0x74, 0x26, 0x00, // leal 0(%esi,1),%esi
- 0x8d, 0xbc, 0x27, 0x00, // leal 0L(%edi,1),%edi
+ const char nop11[11] = { 0x66, 0x66, 0x2e, 0x0f, // data16
+ 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
0x00, 0x00, 0x00 };
- const char nop12[12] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
- 0x00, 0x00, 0x8d, 0xbf, // leal 0L(%edi),%edi
+ const char nop12[12] = { 0x66, 0x66, 0x66, 0x2e, // data16; data16
+ 0x0f, 0x1f, 0x84, 0x00, // nopw %cs:0L(%rax,%rax,1)
0x00, 0x00, 0x00, 0x00 };
- const char nop13[13] = { 0x8d, 0xb6, 0x00, 0x00, // leal 0L(%esi),%esi
- 0x00, 0x00, 0x8d, 0xbc, // leal 0L(%edi,1),%edi
- 0x27, 0x00, 0x00, 0x00,
+ const char nop13[13] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x2e, 0x0f, 0x1f, 0x84, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00, 0x00,
0x00 };
- const char nop14[14] = { 0x8d, 0xb4, 0x26, 0x00, // leal 0L(%esi,1),%esi
- 0x00, 0x00, 0x00, 0x8d, // leal 0L(%edi,1),%edi
- 0xbc, 0x27, 0x00, 0x00,
+ const char nop14[14] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x66, 0x2e, 0x0f, 0x1f, // data16
+ 0x84, 0x00, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
0x00, 0x00 };
- const char nop15[15] = { 0xeb, 0x0d, 0x90, 0x90, // jmp .+15
- 0x90, 0x90, 0x90, 0x90, // nop,nop,nop,...
- 0x90, 0x90, 0x90, 0x90,
- 0x90, 0x90, 0x90 };
+ const char nop15[15] = { 0x66, 0x66, 0x66, 0x66, // data16; data16; data16
+ 0x66, 0x66, 0x2e, 0x0f, // data16; data16
+ 0x1f, 0x84, 0x00, 0x00, // nopw %cs:0L(%rax,%rax,1)
+ 0x00, 0x00, 0x00 };
const char* nops[16] = {
NULL,
return std::string(nops[length], length);
}
+// FNOFFSET in section SHNDX in OBJECT is the start of a function
+// compiled with -fstack-split. The function calls non-stack-split
+// code. We have to change the function so that it always ensures
+// that it has enough stack space to run some random function.
+
+void
+Target_x86_64::do_calls_non_split(Relobj* object, unsigned int shndx,
+ section_offset_type fnoffset,
+ section_size_type fnsize,
+ unsigned char* view,
+ section_size_type view_size,
+ std::string* from,
+ std::string* to) const
+{
+ // The function starts with a comparison of the stack pointer and a
+ // field in the TCB. This is followed by a jump.
+
+ // cmp %fs:NN,%rsp
+ if (this->match_view(view, view_size, fnoffset, "\x64\x48\x3b\x24\x25", 5)
+ && fnsize > 9)
+ {
+ // We will call __morestack if the carry flag is set after this
+ // comparison. We turn the comparison into an stc instruction
+ // and some nops.
+ view[fnoffset] = '\xf9';
+ this->set_view_to_nop(view, view_size, fnoffset + 1, 8);
+ }
+ // lea NN(%rsp),%r10
+ else if (this->match_view(view, view_size, fnoffset, "\x4c\x8d\x94\x24", 4)
+ && fnsize > 8)
+ {
+ // This is loading an offset from the stack pointer for a
+ // comparison. The offset is negative, so we decrease the
+ // offset by the amount of space we need for the stack. This
+ // means we will avoid calling __morestack if there happens to
+ // be plenty of space on the stack already.
+ unsigned char* pval = view + fnoffset + 4;
+ uint32_t val = elfcpp::Swap_unaligned<32, false>::readval(pval);
+ val -= parameters->options().split_stack_adjust_size();
+ elfcpp::Swap_unaligned<32, false>::writeval(pval, val);
+ }
+ else
+ {
+ if (!object->has_no_split_stack())
+ object->error(_("failed to match split-stack sequence at "
+ "section %u offset %0zx"),
+ shndx, fnoffset);
+ return;
+ }
+
+ // We have to change the function so that it calls
+ // __morestack_non_split instead of __morestack. The former will
+ // allocate additional stack space.
+ *from = "__morestack";
+ *to = "__morestack_non_split";
+}
+
// The selector for x86_64 object files.
-class Target_selector_x86_64 : public Target_selector
+class Target_selector_x86_64 : public Target_selector_freebsd
{
public:
Target_selector_x86_64()
- : Target_selector(elfcpp::EM_X86_64, 64, false)
+ : Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
+ "elf64-x86-64-freebsd")
{ }
Target*
- recognize(int machine, int osabi, int abiversion);
+ do_instantiate_target()
+ { return new Target_x86_64(); }
- private:
- Target_x86_64* target_;
};
-// Recognize an x86_64 object file when we already know that the machine
-// number is EM_X86_64.
-
-Target*
-Target_selector_x86_64::recognize(int, int, int)
-{
- if (this->target_ == NULL)
- this->target_ = new Target_x86_64();
- return this->target_;
-}
-
Target_selector_x86_64 target_selector_x86_64;
} // End anonymous namespace.
projects / deliverable / binutils-gdb.git / blobdiff