// x86_64.cc -- x86_64 target support for gold.
-// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+// Copyright 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
#include <cstring>
#include "elfcpp.h"
+#include "dwarf.h"
#include "parameters.h"
#include "reloc.h"
#include "x86_64.h"
using namespace gold;
-class Output_data_plt_x86_64;
+// 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* layout, Output_data_got<64, false>* got,
+ Output_data_space* got_plt,
+ Output_data_space* got_irelative)
+ : Output_section_data(16), layout_(layout), tlsdesc_rel_(NULL),
+ irelative_rel_(NULL), got_(got), got_plt_(got_plt),
+ got_irelative_(got_irelative), count_(0), irelative_count_(0),
+ tlsdesc_got_offset_(-1U), free_list_()
+ { this->init(layout); }
+
+ Output_data_plt_x86_64(Layout* layout, Output_data_got<64, false>* got,
+ Output_data_space* got_plt,
+ Output_data_space* got_irelative,
+ unsigned int plt_count)
+ : Output_section_data((plt_count + 1) * plt_entry_size, 16, false),
+ layout_(layout), tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got),
+ got_plt_(got_plt), got_irelative_(got_irelative), count_(plt_count),
+ irelative_count_(0), tlsdesc_got_offset_(-1U), free_list_()
+ {
+ this->init(layout);
+
+ // Initialize the free list and reserve the first entry.
+ this->free_list_.init((plt_count + 1) * plt_entry_size, false);
+ this->free_list_.remove(0, plt_entry_size);
+ }
+
+ // Initialize the PLT section.
+ void
+ init(Layout* layout);
+
+ // Add an entry to the PLT.
+ void
+ add_entry(Symbol_table*, Layout*, Symbol* gsym);
+
+ // Add an entry to the PLT for a local STT_GNU_IFUNC symbol.
+ unsigned int
+ add_local_ifunc_entry(Symbol_table* symtab, Layout*,
+ Sized_relobj_file<64, false>* relobj,
+ unsigned int local_sym_index);
+
+ // Add the relocation for a PLT entry.
+ void
+ add_relocation(Symbol_table*, Layout*, Symbol* gsym,
+ unsigned int got_offset);
+
+ // 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_ + this->irelative_count_ + 1) * plt_entry_size; }
+
+ // Return the .rela.plt section data.
+ Reloc_section*
+ rela_plt()
+ { return this->rel_; }
+
+ // Return where the TLSDESC relocations should go.
+ Reloc_section*
+ rela_tlsdesc(Layout*);
+
+ // Return where the IRELATIVE relocations should go in the PLT
+ // relocations.
+ Reloc_section*
+ rela_irelative(Symbol_table*, Layout*);
+
+ // Return whether we created a section for IRELATIVE relocations.
+ bool
+ has_irelative_section() const
+ { return this->irelative_rel_ != NULL; }
+
+ // Return the number of PLT entries.
+ unsigned int
+ entry_count() const
+ { return this->count_ + this->irelative_count_; }
+
+ // Return the offset of the first non-reserved PLT entry.
+ static unsigned int
+ first_plt_entry_offset()
+ { return plt_entry_size; }
+
+ // Return the size of a PLT entry.
+ static unsigned int
+ get_plt_entry_size()
+ { return plt_entry_size; }
+
+ // Reserve a slot in the PLT for an existing symbol in an incremental update.
+ void
+ reserve_slot(unsigned int plt_index)
+ {
+ this->free_list_.remove((plt_index + 1) * plt_entry_size,
+ (plt_index + 2) * plt_entry_size);
+ }
+
+ // Return the PLT address to use for a global symbol.
+ uint64_t
+ address_for_global(const Symbol*);
+
+ // Return the PLT address to use for a local symbol.
+ uint64_t
+ address_for_local(const Relobj*, unsigned int symndx);
+
+ 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 const unsigned char first_plt_entry[plt_entry_size];
+
+ // Other entries in the PLT for an executable.
+ static const unsigned char plt_entry[plt_entry_size];
+
+ // The reserved TLSDESC entry in the PLT for an executable.
+ static const unsigned char tlsdesc_plt_entry[plt_entry_size];
+
+ // The .eh_frame unwind information for the PLT.
+ static const int plt_eh_frame_cie_size = 16;
+ static const int plt_eh_frame_fde_size = 32;
+ static const unsigned char plt_eh_frame_cie[plt_eh_frame_cie_size];
+ static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
+
+ // Set the final size.
+ void
+ set_final_data_size();
+
+ // Write out the PLT data.
+ void
+ do_write(Output_file*);
+
+ // A pointer to the Layout class, so that we can find the .dynamic
+ // section when we write out the GOT PLT section.
+ Layout* layout_;
+ // The reloc section.
+ Reloc_section* rel_;
+ // The TLSDESC relocs, if necessary. These must follow the regular
+ // PLT relocs.
+ Reloc_section* tlsdesc_rel_;
+ // The IRELATIVE relocs, if necessary. These must follow the
+ // regular PLT relocations and the TLSDESC relocations.
+ Reloc_section* irelative_rel_;
+ // The .got section.
+ Output_data_got<64, false>* got_;
+ // The .got.plt section.
+ Output_data_space* got_plt_;
+ // The part of the .got.plt section used for IRELATIVE relocs.
+ Output_data_space* got_irelative_;
+ // The number of PLT entries.
+ unsigned int count_;
+ // Number of PLT entries with R_X86_64_IRELATIVE relocs. These
+ // follow the regular PLT entries.
+ unsigned int irelative_count_;
+ // Offset of the reserved TLSDESC_GOT entry when needed.
+ unsigned int tlsdesc_got_offset_;
+ // List of available regions within the section, for incremental
+ // update links.
+ Free_list free_list_;
+};
// The x86_64 target class.
// See the ABI at
// 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>
+class Target_x86_64 : public Sized_target<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()
- : Target_freebsd<64, false>(&x86_64_info),
- got_(NULL), plt_(NULL), got_plt_(NULL), got_tlsdesc_(NULL),
- global_offset_table_(NULL), rela_dyn_(NULL),
- copy_relocs_(elfcpp::R_X86_64_COPY), dynbss_(NULL),
- got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
+ : Sized_target<64, false>(&x86_64_info),
+ got_(NULL), plt_(NULL), got_plt_(NULL), got_irelative_(NULL),
+ got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
+ rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
+ dynbss_(NULL), got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
tls_base_symbol_defined_(false)
{ }
- // This function should be defined in targets that can use relocation
- // types to determine (implemented in local_reloc_may_be_function_pointer
- // and global_reloc_may_be_function_pointer)
- // if a function's pointer is taken. ICF uses this in safe mode to only
- // fold those functions whose pointer is defintely not taken. For x86_64
- // pie binaries, safe ICF cannot be done by looking at relocation types.
- inline bool
- can_check_for_function_pointers() const
- { return !parameters->options().pie(); }
-
// Hook for a new output section.
void
do_new_output_section(Output_section*) const;
void
gc_process_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
void
scan_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
void
scan_relocatable_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
uint64_t
do_reloc_addend(void* arg, unsigned int r_type, uint64_t addend) const;
- // Adjust -fstack-split code which calls non-stack-split code.
+ // Return the PLT section.
+ uint64_t
+ do_plt_address_for_global(const Symbol* gsym) const
+ { return this->plt_section()->address_for_global(gsym); }
+
+ uint64_t
+ do_plt_address_for_local(const Relobj* relobj, unsigned int symndx) const
+ { return this->plt_section()->address_for_local(relobj, symndx); }
+
+ // This function should be defined in targets that can use relocation
+ // types to determine (implemented in local_reloc_may_be_function_pointer
+ // and global_reloc_may_be_function_pointer)
+ // if a function's pointer is taken. ICF uses this in safe mode to only
+ // fold those functions whose pointer is defintely not taken. For x86_64
+ // pie binaries, safe ICF cannot be done by looking at relocation types.
+ bool
+ do_can_check_for_function_pointers() const
+ { return !parameters->options().pie(); }
+
+ // Return the base for a DW_EH_PE_datarel encoding.
+ uint64_t
+ do_ehframe_datarel_base() const;
+
+ // Adjust -fsplit-stack code which calls non-split-stack code.
void
do_calls_non_split(Relobj* object, unsigned int shndx,
section_offset_type fnoffset, section_size_type fnsize,
// Return the size of the GOT section.
section_size_type
- got_size()
+ got_size() const
{
gold_assert(this->got_ != NULL);
return this->got_->data_size();
}
+ // Return the number of entries in the GOT.
+ unsigned int
+ got_entry_count() const
+ {
+ if (this->got_ == NULL)
+ return 0;
+ return this->got_size() / 8;
+ }
+
+ // Return the number of entries in the PLT.
+ unsigned int
+ plt_entry_count() const;
+
+ // Return the offset of the first non-reserved PLT entry.
+ unsigned int
+ first_plt_entry_offset() const;
+
+ // Return the size of each PLT entry.
+ unsigned int
+ plt_entry_size() const;
+
+ // Create the GOT section for an incremental update.
+ Output_data_got<64, false>*
+ init_got_plt_for_update(Symbol_table* symtab,
+ Layout* layout,
+ unsigned int got_count,
+ unsigned int plt_count);
+
+ // Reserve a GOT entry for a local symbol, and regenerate any
+ // necessary dynamic relocations.
+ void
+ reserve_local_got_entry(unsigned int got_index,
+ Sized_relobj<64, false>* obj,
+ unsigned int r_sym,
+ unsigned int got_type);
+
+ // Reserve a GOT entry for a global symbol, and regenerate any
+ // necessary dynamic relocations.
+ void
+ reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
+ unsigned int got_type);
+
+ // Register an existing PLT entry for a global symbol.
+ void
+ register_global_plt_entry(Symbol_table*, Layout*, unsigned int plt_index,
+ Symbol* gsym);
+
+ // Force a COPY relocation for a given symbol.
+ void
+ emit_copy_reloc(Symbol_table*, Symbol*, Output_section*, off_t);
+
+ // Apply an incremental relocation.
+ void
+ apply_relocation(const Relocate_info<64, false>* relinfo,
+ elfcpp::Elf_types<64>::Elf_Addr r_offset,
+ unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Swxword r_addend,
+ const Symbol* gsym,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
+ section_size_type view_size);
+
// Add a new reloc argument, returning the index in the vector.
size_t
- add_tlsdesc_info(Sized_relobj<64, false>* object, unsigned int r_sym)
+ add_tlsdesc_info(Sized_relobj_file<64, false>* object, unsigned int r_sym)
{
this->tlsdesc_reloc_info_.push_back(Tlsdesc_info(object, r_sym));
return this->tlsdesc_reloc_info_.size() - 1;
: issued_non_pic_error_(false)
{ }
+ static inline int
+ get_reference_flags(unsigned int r_type);
+
inline void
local(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
inline void
global(Symbol_table* symtab, Layout* layout, Target_x86_64* target,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<64, false>& reloc, unsigned int r_type,
inline bool
local_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
Target_x86_64* target,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<64, false>& reloc,
inline bool
global_reloc_may_be_function_pointer(Symbol_table* symtab, Layout* layout,
Target_x86_64* target,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<64, false>& reloc,
private:
static void
- unsupported_reloc_local(Sized_relobj<64, false>*, unsigned int r_type);
+ unsupported_reloc_local(Sized_relobj_file<64, false>*, unsigned int r_type);
static void
- unsupported_reloc_global(Sized_relobj<64, false>*, unsigned int r_type,
+ unsupported_reloc_global(Sized_relobj_file<64, false>*, unsigned int r_type,
Symbol*);
void
- check_non_pic(Relobj*, unsigned int r_type);
+ check_non_pic(Relobj*, unsigned int r_type, Symbol*);
inline bool
possible_function_pointer_reloc(unsigned int r_type);
+ bool
+ reloc_needs_plt_for_ifunc(Sized_relobj_file<64, false>*,
+ unsigned int r_type);
+
// Whether we have issued an error about a non-PIC compilation.
bool issued_non_pic_error_;
};
{
public:
Relocate()
- : skip_call_tls_get_addr_(false), saw_tls_block_reloc_(false)
+ : skip_call_tls_get_addr_(false)
{ }
~Relocate()
// 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,
void
make_plt_entry(Symbol_table*, Layout*, Symbol*);
+ // Create a PLT entry for a local STT_GNU_IFUNC symbol.
+ void
+ make_local_ifunc_plt_entry(Symbol_table*, Layout*,
+ Sized_relobj_file<64, false>* relobj,
+ unsigned int local_sym_index);
+
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
void
define_tls_base_symbol(Symbol_table*, 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);
+ Sized_relobj_file<64, false>* object);
// Get the PLT section.
Output_data_plt_x86_64*
Reloc_section*
rela_tlsdesc_section(Layout*) const;
+ // Get the section to use for IRELATIVE relocations.
+ Reloc_section*
+ rela_irelative_section(Layout*);
+
// Add a potential copy relocation.
void
copy_reloc(Symbol_table* symtab, Layout* layout,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int shndx, Output_section* output_section,
Symbol* sym, const elfcpp::Rela<64, false>& reloc)
{
// general Target structure.
static const Target::Target_info x86_64_info;
+ // The types of GOT entries needed for this platform.
+ // These values are exposed to the ABI in an incremental link.
+ // Do not renumber existing values without changing the version
+ // number of the .gnu_incremental_inputs section.
enum Got_type
{
GOT_TYPE_STANDARD = 0, // GOT entry for a regular symbol
// R_X86_64_TLSDESC against a local symbol.
struct Tlsdesc_info
{
- Tlsdesc_info(Sized_relobj<64, false>* a_object, unsigned int a_r_sym)
+ Tlsdesc_info(Sized_relobj_file<64, false>* a_object, unsigned int a_r_sym)
: object(a_object), r_sym(a_r_sym)
{ }
// The object in which the local symbol is defined.
- Sized_relobj<64, false>* object;
+ Sized_relobj_file<64, false>* object;
// The local symbol index in the object.
unsigned int r_sym;
};
Output_data_plt_x86_64* plt_;
// The GOT PLT section.
Output_data_space* got_plt_;
+ // The GOT section for IRELATIVE relocations.
+ Output_data_space* got_irelative_;
// The GOT section for TLSDESC relocations.
Output_data_got<64, false>* got_tlsdesc_;
// The _GLOBAL_OFFSET_TABLE_ symbol.
Symbol* global_offset_table_;
// The dynamic reloc section.
Reloc_section* rela_dyn_;
+ // The section to use for IRELATIVE relocs.
+ Reloc_section* rela_irelative_;
// Relocs saved to avoid a COPY reloc.
Copy_relocs<elfcpp::SHT_RELA, 64, false> copy_relocs_;
// Space for variables copied with a COPY reloc.
false, // has_resolve
true, // has_code_fill
true, // is_default_stack_executable
+ true, // can_icf_inline_merge_sections
'\0', // wrap_char
"/lib/ld64.so.1", // program interpreter
0x400000, // default_text_segment_address
// we handle the SHF_X86_64_LARGE.
void
-Target_x86_64::do_new_output_section(Output_section *os) const
+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();
{
gold_assert(symtab != NULL && layout != NULL);
+ // When using -z now, we can treat .got.plt as a relro section.
+ // Without -z now, it is modified after program startup by lazy
+ // PLT relocations.
+ bool is_got_plt_relro = parameters->options().now();
+ Output_section_order got_order = (is_got_plt_relro
+ ? ORDER_RELRO
+ : ORDER_RELRO_LAST);
+ Output_section_order got_plt_order = (is_got_plt_relro
+ ? ORDER_RELRO
+ : ORDER_NON_RELRO_FIRST);
+
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_, ORDER_RELRO_LAST,
- true);
+ this->got_, got_order, true);
this->got_plt_ = new Output_data_space(8, "** GOT PLT");
layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
- this->got_plt_, ORDER_NON_RELRO_FIRST,
- false);
+ this->got_plt_, got_plt_order,
+ is_got_plt_relro);
// The first three entries are reserved.
this->got_plt_->set_current_data_size(3 * 8);
- // Those bytes can go into the relro segment.
- layout->increase_relro(3 * 8);
+ if (!is_got_plt_relro)
+ {
+ // Those bytes can go into the relro segment.
+ layout->increase_relro(3 * 8);
+ }
// Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
this->global_offset_table_ =
elfcpp::STV_HIDDEN, 0,
false, false);
+ // If there are any IRELATIVE relocations, they get GOT entries
+ // in .got.plt after the jump slot entries.
+ this->got_irelative_ = new Output_data_space(8, "** GOT IRELATIVE PLT");
+ layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_irelative_,
+ got_plt_order, is_got_plt_relro);
+
// If there are any TLSDESC relocations, they get GOT entries in
- // .got.plt after the jump slot entries.
+ // .got.plt after the jump slot and IRELATIVE entries.
this->got_tlsdesc_ = new Output_data_got<64, false>();
layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
this->got_tlsdesc_,
- ORDER_NON_RELRO_FIRST, false);
+ got_plt_order, is_got_plt_relro);
}
return this->got_;
return this->rela_dyn_;
}
-// A class to handle the PLT data.
+// Get the section to use for IRELATIVE relocs, creating it if
+// necessary. These go in .rela.dyn, but only after all other dynamic
+// relocations. They need to follow the other dynamic relocations so
+// that they can refer to global variables initialized by those
+// relocs.
-class Output_data_plt_x86_64 : public Output_section_data
+Target_x86_64::Reloc_section*
+Target_x86_64::rela_irelative_section(Layout* layout)
{
- 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 .rela.plt section data.
- const Reloc_section*
- rela_plt() const
- { return this->rel_; }
-
- // Return where the TLSDESC relocations should go.
- Reloc_section*
- rela_tlsdesc(Layout*);
-
- 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 TLSDESC relocs, if necessary. These must follow the regular
- // PLT relocs.
- Reloc_section* tlsdesc_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_;
-};
+ if (this->rela_irelative_ == NULL)
+ {
+ // Make sure we have already created the dynamic reloc section.
+ this->rela_dyn_section(layout);
+ this->rela_irelative_ = new Reloc_section(false);
+ layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
+ elfcpp::SHF_ALLOC, this->rela_irelative_,
+ ORDER_DYNAMIC_RELOCS, false);
+ gold_assert(this->rela_dyn_->output_section()
+ == this->rela_irelative_->output_section());
+ }
+ return this->rela_irelative_;
+}
-// 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.
+// Initialize the PLT section.
-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), tlsdesc_rel_(NULL), got_(got), got_plt_(got_plt),
- count_(0), tlsdesc_got_offset_(-1U)
+void
+Output_data_plt_x86_64::init(Layout* layout)
{
this->rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
elfcpp::SHF_ALLOC, this->rel_,
ORDER_DYNAMIC_PLT_RELOCS, false);
+
+ // Add unwind information if requested.
+ if (parameters->options().ld_generated_unwind_info())
+ layout->add_eh_frame_for_plt(this, plt_eh_frame_cie, plt_eh_frame_cie_size,
+ plt_eh_frame_fde, plt_eh_frame_fde_size);
}
void
// Add an entry to the PLT.
void
-Output_data_plt_x86_64::add_entry(Symbol* gsym)
+Output_data_plt_x86_64::add_entry(Symbol_table* symtab, Layout* layout,
+ 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);
+ unsigned int plt_index;
+ off_t plt_offset;
+ section_offset_type got_offset;
- ++this->count_;
+ unsigned int* pcount;
+ unsigned int offset;
+ unsigned int reserved;
+ Output_data_space* got;
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ {
+ pcount = &this->irelative_count_;
+ offset = 0;
+ reserved = 0;
+ got = this->got_irelative_;
+ }
+ else
+ {
+ pcount = &this->count_;
+ offset = 1;
+ reserved = 3;
+ got = this->got_plt_;
+ }
- section_offset_type got_offset = this->got_plt_->current_data_size();
+ if (!this->is_data_size_valid())
+ {
+ // Note that when setting the PLT offset for a non-IRELATIVE
+ // entry we skip the initial reserved PLT entry.
+ plt_index = *pcount + offset;
+ plt_offset = plt_index * plt_entry_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);
+ ++*pcount;
+
+ got_offset = (plt_index - offset + reserved) * 8;
+ gold_assert(got_offset == got->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).
+ got->set_current_data_size(got_offset + 8);
+ }
+ else
+ {
+ // FIXME: This is probably not correct for IRELATIVE relocs.
+
+ // For incremental updates, find an available slot.
+ plt_offset = this->free_list_.allocate(plt_entry_size, plt_entry_size, 0);
+ if (plt_offset == -1)
+ gold_fallback(_("out of patch space (PLT);"
+ " relink with --incremental-full"));
+
+ // The GOT and PLT entries have a 1-1 correspondance, so the GOT offset
+ // can be calculated from the PLT index, adjusting for the three
+ // reserved entries at the beginning of the GOT.
+ plt_index = plt_offset / plt_entry_size - 1;
+ got_offset = (plt_index - offset + reserved) * 8;
+ }
+
+ gsym->set_plt_offset(plt_offset);
// 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);
+ this->add_relocation(symtab, layout, gsym, got_offset);
// Note that we don't need to save the symbol. The contents of the
// PLT are independent of which symbols are used. The symbols only
// appear in the relocations.
}
-// Return where the TLSDESC relocations should go, creating it if
-// necessary. These follow the JUMP_SLOT relocations.
+// Add an entry to the PLT for a local STT_GNU_IFUNC symbol. Return
+// the PLT offset.
+
+unsigned int
+Output_data_plt_x86_64::add_local_ifunc_entry(
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<64, false>* relobj,
+ unsigned int local_sym_index)
+{
+ unsigned int plt_offset = this->irelative_count_ * plt_entry_size;
+ ++this->irelative_count_;
+
+ section_offset_type got_offset = this->got_irelative_->current_data_size();
+
+ // Every PLT entry needs a GOT entry which points back to the PLT
+ // entry.
+ this->got_irelative_->set_current_data_size(got_offset + 8);
+
+ // Every PLT entry needs a reloc.
+ Reloc_section* rela = this->rela_irelative(symtab, layout);
+ rela->add_symbolless_local_addend(relobj, local_sym_index,
+ elfcpp::R_X86_64_IRELATIVE,
+ this->got_irelative_, got_offset, 0);
+
+ return plt_offset;
+}
+
+// Add the relocation for a PLT entry.
+
+void
+Output_data_plt_x86_64::add_relocation(Symbol_table* symtab, Layout* layout,
+ Symbol* gsym, unsigned int got_offset)
+{
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ {
+ Reloc_section* rela = this->rela_irelative(symtab, layout);
+ rela->add_symbolless_global_addend(gsym, elfcpp::R_X86_64_IRELATIVE,
+ this->got_irelative_, got_offset, 0);
+ }
+ else
+ {
+ gsym->set_needs_dynsym_entry();
+ this->rel_->add_global(gsym, elfcpp::R_X86_64_JUMP_SLOT, this->got_plt_,
+ got_offset, 0);
+ }
+}
+
+// Return where the TLSDESC relocations should go, creating it if
+// necessary. These follow the JUMP_SLOT relocations.
+
+Output_data_plt_x86_64::Reloc_section*
+Output_data_plt_x86_64::rela_tlsdesc(Layout* layout)
+{
+ if (this->tlsdesc_rel_ == NULL)
+ {
+ this->tlsdesc_rel_ = new Reloc_section(false);
+ layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
+ elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
+ ORDER_DYNAMIC_PLT_RELOCS, false);
+ gold_assert(this->tlsdesc_rel_->output_section()
+ == this->rel_->output_section());
+ }
+ return this->tlsdesc_rel_;
+}
+
+// Return where the IRELATIVE relocations should go in the PLT. These
+// follow the JUMP_SLOT and the TLSDESC relocations.
Output_data_plt_x86_64::Reloc_section*
-Output_data_plt_x86_64::rela_tlsdesc(Layout* layout)
+Output_data_plt_x86_64::rela_irelative(Symbol_table* symtab, Layout* layout)
{
- if (this->tlsdesc_rel_ == NULL)
+ if (this->irelative_rel_ == NULL)
{
- this->tlsdesc_rel_ = new Reloc_section(false);
+ // Make sure we have a place for the TLSDESC relocations, in
+ // case we see any later on.
+ this->rela_tlsdesc(layout);
+ this->irelative_rel_ = new Reloc_section(false);
layout->add_output_section_data(".rela.plt", elfcpp::SHT_RELA,
- elfcpp::SHF_ALLOC, this->tlsdesc_rel_,
+ elfcpp::SHF_ALLOC, this->irelative_rel_,
ORDER_DYNAMIC_PLT_RELOCS, false);
- gold_assert(this->tlsdesc_rel_->output_section() ==
- this->rel_->output_section());
+ gold_assert(this->irelative_rel_->output_section()
+ == this->rel_->output_section());
+
+ if (parameters->doing_static_link())
+ {
+ // A statically linked executable will only have a .rela.plt
+ // section to hold R_X86_64_IRELATIVE relocs for
+ // STT_GNU_IFUNC symbols. The library will use these
+ // symbols to locate the IRELATIVE relocs at program startup
+ // time.
+ symtab->define_in_output_data("__rela_iplt_start", NULL,
+ Symbol_table::PREDEFINED,
+ this->irelative_rel_, 0, 0,
+ elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
+ elfcpp::STV_HIDDEN, 0, false, true);
+ symtab->define_in_output_data("__rela_iplt_end", NULL,
+ Symbol_table::PREDEFINED,
+ this->irelative_rel_, 0, 0,
+ elfcpp::STT_NOTYPE, elfcpp::STB_GLOBAL,
+ elfcpp::STV_HIDDEN, 0, true, true);
+ }
}
- return this->tlsdesc_rel_;
+ return this->irelative_rel_;
+}
+
+// Return the PLT address to use for a global symbol.
+
+uint64_t
+Output_data_plt_x86_64::address_for_global(const Symbol* gsym)
+{
+ uint64_t offset = 0;
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ offset = (this->count_ + 1) * plt_entry_size;
+ return this->address() + offset;
+}
+
+// Return the PLT address to use for a local symbol. These are always
+// IRELATIVE relocs.
+
+uint64_t
+Output_data_plt_x86_64::address_for_local(const Relobj*, unsigned int)
+{
+ return this->address() + (this->count_ + 1) * plt_entry_size;
}
// Set the final size.
void
Output_data_plt_x86_64::set_final_data_size()
{
- unsigned int count = this->count_;
+ unsigned int count = this->count_ + this->irelative_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] =
+const 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
// Subsequent entries in the PLT for an executable.
-unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
+const unsigned char Output_data_plt_x86_64::plt_entry[plt_entry_size] =
{
// From AMD64 ABI Draft 0.98, page 76
0xff, 0x25, // jmpq indirect
// The reserved TLSDESC entry in the PLT for an executable.
-unsigned char Output_data_plt_x86_64::tlsdesc_plt_entry[plt_entry_size] =
+const 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).
0x40, 0
};
+// The .eh_frame unwind information for the PLT.
+
+const unsigned char
+Output_data_plt_x86_64::plt_eh_frame_cie[plt_eh_frame_cie_size] =
+{
+ 1, // CIE version.
+ 'z', // Augmentation: augmentation size included.
+ 'R', // Augmentation: FDE encoding included.
+ '\0', // End of augmentation string.
+ 1, // Code alignment factor.
+ 0x78, // Data alignment factor.
+ 16, // Return address column.
+ 1, // Augmentation size.
+ (elfcpp::DW_EH_PE_pcrel // FDE encoding.
+ | elfcpp::DW_EH_PE_sdata4),
+ elfcpp::DW_CFA_def_cfa, 7, 8, // DW_CFA_def_cfa: r7 (rsp) ofs 8.
+ elfcpp::DW_CFA_offset + 16, 1,// DW_CFA_offset: r16 (rip) at cfa-8.
+ elfcpp::DW_CFA_nop, // Align to 16 bytes.
+ elfcpp::DW_CFA_nop
+};
+
+const unsigned char
+Output_data_plt_x86_64::plt_eh_frame_fde[plt_eh_frame_fde_size] =
+{
+ 0, 0, 0, 0, // Replaced with offset to .plt.
+ 0, 0, 0, 0, // Replaced with size of .plt.
+ 0, // Augmentation size.
+ elfcpp::DW_CFA_def_cfa_offset, 16, // DW_CFA_def_cfa_offset: 16.
+ elfcpp::DW_CFA_advance_loc + 6, // Advance 6 to __PLT__ + 6.
+ elfcpp::DW_CFA_def_cfa_offset, 24, // DW_CFA_def_cfa_offset: 24.
+ elfcpp::DW_CFA_advance_loc + 10, // Advance 10 to __PLT__ + 16.
+ elfcpp::DW_CFA_def_cfa_expression, // DW_CFA_def_cfa_expression.
+ 11, // Block length.
+ elfcpp::DW_OP_breg7, 8, // Push %rsp + 8.
+ elfcpp::DW_OP_breg16, 0, // Push %rip.
+ elfcpp::DW_OP_lit15, // Push 0xf.
+ elfcpp::DW_OP_and, // & (%rip & 0xf).
+ elfcpp::DW_OP_lit11, // Push 0xb.
+ elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 0xb)
+ elfcpp::DW_OP_lit3, // Push 3.
+ elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 0xb) << 3)
+ elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=0xb)<<3)+%rsp+8
+ elfcpp::DW_CFA_nop, // Align to 32 bytes.
+ elfcpp::DW_CFA_nop,
+ elfcpp::DW_CFA_nop,
+ elfcpp::DW_CFA_nop
+};
+
// 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* const oview = of->get_output_view(offset, oview_size);
const off_t got_file_offset = this->got_plt_->offset();
+ gold_assert(parameters->incremental_update()
+ || (got_file_offset + this->got_plt_->data_size()
+ == this->got_irelative_->offset()));
const section_size_type got_size =
- convert_to_section_size_type(this->got_plt_->data_size());
+ convert_to_section_size_type(this->got_plt_->data_size()
+ + this->got_irelative_->data_size());
unsigned char* const got_view = of->get_output_view(got_file_offset,
got_size);
unsigned char* got_pov = got_view;
- memset(got_pov, 0, 24);
- got_pov += 24;
+ // The first entry in the GOT is the address of the .dynamic section
+ // aka the PT_DYNAMIC segment. The next two entries are reserved.
+ // We saved space for them when we created the section in
+ // Target_x86_64::got_section.
+ Output_section* dynamic = this->layout_->dynamic_section();
+ uint32_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
+ elfcpp::Swap<64, false>::writeval(got_pov, dynamic_addr);
+ got_pov += 8;
+ memset(got_pov, 0, 16);
+ got_pov += 16;
unsigned int plt_offset = plt_entry_size;
unsigned int got_offset = 24;
- const unsigned int count = this->count_;
+ const unsigned int count = this->count_ + this->irelative_count_;
for (unsigned int plt_index = 0;
plt_index < count;
++plt_index,
this->got_section(symtab, layout);
this->plt_ = new Output_data_plt_x86_64(layout, this->got_,
- this->got_plt_);
+ this->got_plt_,
+ this->got_irelative_);
layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_EXECINSTR),
this->plt_, ORDER_PLT, false);
+
+ // Make the sh_info field of .rela.plt point to .plt.
+ Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
+ rela_plt_os->set_info_section(this->plt_->output_section());
}
}
if (this->plt_ == NULL)
this->make_plt_section(symtab, layout);
- this->plt_->add_entry(gsym);
+ this->plt_->add_entry(symtab, layout, gsym);
+}
+
+// Make a PLT entry for a local STT_GNU_IFUNC symbol.
+
+void
+Target_x86_64::make_local_ifunc_plt_entry(Symbol_table* symtab, Layout* layout,
+ Sized_relobj_file<64, false>* relobj,
+ unsigned int local_sym_index)
+{
+ if (relobj->local_has_plt_offset(local_sym_index))
+ return;
+ if (this->plt_ == NULL)
+ this->make_plt_section(symtab, layout);
+ unsigned int plt_offset = this->plt_->add_local_ifunc_entry(symtab, layout,
+ relobj,
+ local_sym_index);
+ relobj->set_local_plt_offset(local_sym_index, plt_offset);
+}
+
+// Return the number of entries in the PLT.
+
+unsigned int
+Target_x86_64::plt_entry_count() const
+{
+ if (this->plt_ == NULL)
+ return 0;
+ return this->plt_->entry_count();
+}
+
+// Return the offset of the first non-reserved PLT entry.
+
+unsigned int
+Target_x86_64::first_plt_entry_offset() const
+{
+ return Output_data_plt_x86_64::first_plt_entry_offset();
+}
+
+// Return the size of each PLT entry.
+
+unsigned int
+Target_x86_64::plt_entry_size() const
+{
+ return Output_data_plt_x86_64::get_plt_entry_size();
+}
+
+// Create the GOT and PLT sections for an incremental update.
+
+Output_data_got<64, false>*
+Target_x86_64::init_got_plt_for_update(Symbol_table* symtab,
+ Layout* layout,
+ unsigned int got_count,
+ unsigned int plt_count)
+{
+ gold_assert(this->got_ == NULL);
+
+ this->got_ = new Output_data_got<64, false>(got_count * 8);
+ layout->add_output_section_data(".got", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_, ORDER_RELRO_LAST,
+ true);
+
+ // Add the three reserved entries.
+ this->got_plt_ = new Output_data_space((plt_count + 3) * 8, 8, "** GOT PLT");
+ layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
+ (elfcpp::SHF_ALLOC
+ | elfcpp::SHF_WRITE),
+ this->got_plt_, ORDER_NON_RELRO_FIRST,
+ false);
+
+ // Define _GLOBAL_OFFSET_TABLE_ at the start of the PLT.
+ this->global_offset_table_ =
+ symtab->define_in_output_data("_GLOBAL_OFFSET_TABLE_", NULL,
+ Symbol_table::PREDEFINED,
+ this->got_plt_,
+ 0, 0, elfcpp::STT_OBJECT,
+ elfcpp::STB_LOCAL,
+ elfcpp::STV_HIDDEN, 0,
+ false, false);
+
+ // If there are any TLSDESC relocations, they get GOT entries in
+ // .got.plt after the jump slot entries.
+ // FIXME: Get the count for TLSDESC entries.
+ this->got_tlsdesc_ = new Output_data_got<64, false>(0);
+ layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
+ this->got_tlsdesc_,
+ ORDER_NON_RELRO_FIRST, false);
+
+ // If there are any IRELATIVE relocations, they get GOT entries in
+ // .got.plt after the jump slot and TLSDESC entries.
+ this->got_irelative_ = new Output_data_space(0, 8, "** GOT IRELATIVE PLT");
+ layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC | elfcpp::SHF_WRITE,
+ this->got_irelative_,
+ ORDER_NON_RELRO_FIRST, false);
+
+ // Create the PLT section.
+ this->plt_ = new Output_data_plt_x86_64(layout, this->got_, this->got_plt_,
+ this->got_irelative_, plt_count);
+ layout->add_output_section_data(".plt", elfcpp::SHT_PROGBITS,
+ elfcpp::SHF_ALLOC | elfcpp::SHF_EXECINSTR,
+ this->plt_, ORDER_PLT, false);
+
+ // Make the sh_info field of .rela.plt point to .plt.
+ Output_section* rela_plt_os = this->plt_->rela_plt()->output_section();
+ rela_plt_os->set_info_section(this->plt_->output_section());
+
+ // Create the rela_dyn section.
+ this->rela_dyn_section(layout);
+
+ return this->got_;
+}
+
+// Reserve a GOT entry for a local symbol, and regenerate any
+// necessary dynamic relocations.
+
+void
+Target_x86_64::reserve_local_got_entry(
+ unsigned int got_index,
+ Sized_relobj<64, false>* obj,
+ unsigned int r_sym,
+ unsigned int got_type)
+{
+ unsigned int got_offset = got_index * 8;
+ Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
+
+ this->got_->reserve_local(got_index, obj, r_sym, got_type);
+ switch (got_type)
+ {
+ case GOT_TYPE_STANDARD:
+ if (parameters->options().output_is_position_independent())
+ rela_dyn->add_local_relative(obj, r_sym, elfcpp::R_X86_64_RELATIVE,
+ this->got_, got_offset, 0, false);
+ break;
+ case GOT_TYPE_TLS_OFFSET:
+ rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_TPOFF64,
+ this->got_, got_offset, 0);
+ break;
+ case GOT_TYPE_TLS_PAIR:
+ this->got_->reserve_slot(got_index + 1);
+ rela_dyn->add_local(obj, r_sym, elfcpp::R_X86_64_DTPMOD64,
+ this->got_, got_offset, 0);
+ break;
+ case GOT_TYPE_TLS_DESC:
+ gold_fatal(_("TLS_DESC not yet supported for incremental linking"));
+ // this->got_->reserve_slot(got_index + 1);
+ // rela_dyn->add_target_specific(elfcpp::R_X86_64_TLSDESC, arg,
+ // this->got_, got_offset, 0);
+ break;
+ default:
+ gold_unreachable();
+ }
+}
+
+// Reserve a GOT entry for a global symbol, and regenerate any
+// necessary dynamic relocations.
+
+void
+Target_x86_64::reserve_global_got_entry(unsigned int got_index, Symbol* gsym,
+ unsigned int got_type)
+{
+ unsigned int got_offset = got_index * 8;
+ Reloc_section* rela_dyn = this->rela_dyn_section(NULL);
+
+ this->got_->reserve_global(got_index, gsym, got_type);
+ switch (got_type)
+ {
+ case GOT_TYPE_STANDARD:
+ if (!gsym->final_value_is_known())
+ {
+ if (gsym->is_from_dynobj()
+ || gsym->is_undefined()
+ || gsym->is_preemptible()
+ || gsym->type() == elfcpp::STT_GNU_IFUNC)
+ rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT,
+ this->got_, got_offset, 0);
+ else
+ rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_RELATIVE,
+ this->got_, got_offset, 0);
+ }
+ break;
+ case GOT_TYPE_TLS_OFFSET:
+ rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TPOFF64,
+ this->got_, got_offset, 0);
+ break;
+ case GOT_TYPE_TLS_PAIR:
+ this->got_->reserve_slot(got_index + 1);
+ rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPMOD64,
+ this->got_, got_offset, 0);
+ rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_DTPOFF64,
+ this->got_, got_offset + 8, 0);
+ break;
+ case GOT_TYPE_TLS_DESC:
+ this->got_->reserve_slot(got_index + 1);
+ rela_dyn->add_global_relative(gsym, elfcpp::R_X86_64_TLSDESC,
+ this->got_, got_offset, 0);
+ break;
+ default:
+ gold_unreachable();
+ }
+}
+
+// Register an existing PLT entry for a global symbol.
+
+void
+Target_x86_64::register_global_plt_entry(Symbol_table* symtab,
+ Layout* layout,
+ unsigned int plt_index,
+ Symbol* gsym)
+{
+ gold_assert(this->plt_ != NULL);
+ gold_assert(!gsym->has_plt_offset());
+
+ this->plt_->reserve_slot(plt_index);
+
+ gsym->set_plt_offset((plt_index + 1) * this->plt_entry_size());
+
+ unsigned int got_offset = (plt_index + 3) * 8;
+ this->plt_->add_relocation(symtab, layout, gsym, got_offset);
+}
+
+// Force a COPY relocation for a given symbol.
+
+void
+Target_x86_64::emit_copy_reloc(
+ Symbol_table* symtab, Symbol* sym, Output_section* os, off_t offset)
+{
+ this->copy_relocs_.emit_copy_reloc(symtab,
+ symtab->get_sized_symbol<64>(sym),
+ os,
+ offset,
+ this->rela_dyn_section(NULL));
}
// Define the _TLS_MODULE_BASE_ symbol in the TLS segment.
unsigned int
Target_x86_64::got_mod_index_entry(Symbol_table* symtab, Layout* layout,
- Sized_relobj<64, false>* object)
+ Sized_relobj_file<64, false>* object)
{
if (this->got_mod_index_offset_ == -1U)
{
}
}
+// Get the Reference_flags for a particular relocation.
+
+int
+Target_x86_64::Scan::get_reference_flags(unsigned int r_type)
+{
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_NONE:
+ case elfcpp::R_X86_64_GNU_VTINHERIT:
+ case elfcpp::R_X86_64_GNU_VTENTRY:
+ case elfcpp::R_X86_64_GOTPC32:
+ case elfcpp::R_X86_64_GOTPC64:
+ // No symbol reference.
+ return 0;
+
+ 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:
+ return Symbol::ABSOLUTE_REF;
+
+ case elfcpp::R_X86_64_PC64:
+ case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PC16:
+ case elfcpp::R_X86_64_PC8:
+ case elfcpp::R_X86_64_GOTOFF64:
+ return Symbol::RELATIVE_REF;
+
+ case elfcpp::R_X86_64_PLT32:
+ case elfcpp::R_X86_64_PLTOFF64:
+ return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
+
+ 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:
+ // Absolute in GOT.
+ return Symbol::ABSOLUTE_REF;
+
+ 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 Symbol::TLS_REF;
+
+ 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:
+ case elfcpp::R_X86_64_IRELATIVE:
+ case elfcpp::R_X86_64_TPOFF64:
+ case elfcpp::R_X86_64_DTPMOD64:
+ case elfcpp::R_X86_64_TLSDESC:
+ case elfcpp::R_X86_64_SIZE32:
+ case elfcpp::R_X86_64_SIZE64:
+ default:
+ // Not expected. We will give an error later.
+ return 0;
+ }
+}
+
// 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)
+Target_x86_64::Scan::unsupported_reloc_local(
+ Sized_relobj_file<64, false>* object,
+ unsigned int r_type)
{
gold_error(_("%s: unsupported reloc %u against local symbol"),
object->name().c_str(), r_type);
// 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.
+// error even if the section is not read-only. If GSYM is not NULL,
+// it is the symbol the relocation is against; if it is NULL, the
+// relocation is against a local symbol.
void
-Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type)
+Target_x86_64::Scan::check_non_pic(Relobj* object, unsigned int r_type,
+ Symbol* gsym)
{
switch (r_type)
{
- // These are the relocation types supported by glibc for x86_64.
+ // These are the relocation types supported by glibc for x86_64
+ // which should always work.
case elfcpp::R_X86_64_RELATIVE:
+ case elfcpp::R_X86_64_IRELATIVE:
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;
+ // glibc supports these reloc types, but they can overflow.
+ case elfcpp::R_X86_64_PC32:
+ // A PC relative reference is OK against a local symbol or if
+ // the symbol is defined locally.
+ if (gsym == NULL
+ || (!gsym->is_from_dynobj()
+ && !gsym->is_undefined()
+ && !gsym->is_preemptible()))
+ return;
+ /* Fall through. */
+ case elfcpp::R_X86_64_32:
+ if (this->issued_non_pic_error_)
+ return;
+ gold_assert(parameters->options().output_is_position_independent());
+ if (gsym == NULL)
+ object->error(_("requires dynamic R_X86_64_32 reloc which may "
+ "overflow at runtime; recompile with -fPIC"));
+ else
+ object->error(_("requires dynamic %s reloc against '%s' which may "
+ "overflow at runtime; recompile with -fPIC"),
+ (r_type == elfcpp::R_X86_64_32
+ ? "R_X86_64_32"
+ : "R_X86_64_PC32"),
+ gsym->name());
+ this->issued_non_pic_error_ = true;
+ return;
+
default:
// This prevents us from issuing more than one error per reloc
// section. But we can still wind up issuing more than one
if (this->issued_non_pic_error_)
return;
gold_assert(parameters->options().output_is_position_independent());
- object->error(_("requires unsupported dynamic reloc; "
- "recompile with -fPIC"));
+ object->error(_("requires unsupported dynamic reloc %u; "
+ "recompile with -fPIC"),
+ r_type);
this->issued_non_pic_error_ = true;
return;
}
}
+// Return whether we need to make a PLT entry for a relocation of the
+// given type against a STT_GNU_IFUNC symbol.
+
+bool
+Target_x86_64::Scan::reloc_needs_plt_for_ifunc(
+ Sized_relobj_file<64, false>* object,
+ unsigned int r_type)
+{
+ int flags = Scan::get_reference_flags(r_type);
+ if (flags & Symbol::TLS_REF)
+ gold_error(_("%s: unsupported TLS reloc %u for IFUNC symbol"),
+ object->name().c_str(), r_type);
+ return flags != 0;
+}
+
// Scan a relocation for a local symbol.
inline void
Target_x86_64::Scan::local(Symbol_table* symtab,
Layout* layout,
Target_x86_64* target,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<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)
{
+ // A local STT_GNU_IFUNC symbol may require a PLT entry.
+ bool is_ifunc = lsym.get_st_type() == elfcpp::STT_GNU_IFUNC;
+ if (is_ifunc && this->reloc_needs_plt_for_ifunc(object, r_type))
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
+ target->make_local_ifunc_plt_entry(symtab, layout, object, r_sym);
+ }
+
switch (r_type)
{
case elfcpp::R_X86_64_NONE:
{
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());
+ 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(), is_ifunc);
}
break;
// because that is always a 64-bit relocation.
if (parameters->options().output_is_position_independent())
{
- this->check_non_pic(object, r_type);
+ this->check_non_pic(object, r_type, NULL);
Reloc_section* rela_dyn = target->rela_dyn_section(layout);
unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
// 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))
+
+ // For a STT_GNU_IFUNC symbol we want the PLT offset. That
+ // lets function pointers compare correctly with shared
+ // libraries. Otherwise we would need an IRELATIVE reloc.
+ bool is_new;
+ if (is_ifunc)
+ is_new = got->add_local_plt(object, r_sym, GOT_TYPE_STANDARD);
+ else
+ is_new = got->add_local(object, r_sym, GOT_TYPE_STANDARD);
+ if (is_new)
{
// If we are generating a shared object, we need to add a
// dynamic relocation for this symbol's GOT entry.
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);
+ {
+ unsigned int got_offset =
+ object->local_got_offset(r_sym, GOT_TYPE_STANDARD);
+ rela_dyn->add_local_relative(object, r_sym,
+ elfcpp::R_X86_64_RELATIVE,
+ got, got_offset, 0, is_ifunc);
+ }
else
{
- this->check_non_pic(object, r_type);
+ this->check_non_pic(object, r_type, NULL);
gold_assert(lsym.get_st_type() != elfcpp::STT_SECTION);
rela_dyn->add_local(
case elfcpp::R_X86_64_GLOB_DAT:
case elfcpp::R_X86_64_JUMP_SLOT:
case elfcpp::R_X86_64_RELATIVE:
+ case elfcpp::R_X86_64_IRELATIVE:
// These are outstanding tls relocs, which are unexpected when linking
case elfcpp::R_X86_64_TPOFF64:
case elfcpp::R_X86_64_DTPMOD64:
// 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)
+Target_x86_64::Scan::unsupported_reloc_global(
+ Sized_relobj_file<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());
Symbol_table* ,
Layout* ,
Target_x86_64* ,
- Sized_relobj<64, false>* ,
+ Sized_relobj_file<64, false>* ,
unsigned int ,
Output_section* ,
const elfcpp::Rela<64, false>& ,
Symbol_table*,
Layout* ,
Target_x86_64* ,
- Sized_relobj<64, false>* ,
+ Sized_relobj_file<64, false>* ,
unsigned int ,
Output_section* ,
const elfcpp::Rela<64, false>& ,
Target_x86_64::Scan::global(Symbol_table* symtab,
Layout* layout,
Target_x86_64* target,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
Output_section* output_section,
const elfcpp::Rela<64, false>& reloc,
unsigned int r_type,
Symbol* gsym)
{
+ // A STT_GNU_IFUNC symbol may require a PLT entry.
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && this->reloc_needs_plt_for_ifunc(object, r_type))
+ target->make_plt_entry(symtab, layout, gsym);
+
switch (r_type)
{
case elfcpp::R_X86_64_NONE:
gsym->set_needs_dynsym_value();
}
// Make a dynamic relocation if necessary.
- if (gsym->needs_dynamic_reloc(Symbol::ABSOLUTE_REF))
+ if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
{
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->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false)
+ && !gsym->is_from_dynobj()
+ && !gsym->is_undefined()
+ && !gsym->is_preemptible())
+ {
+ // Use an IRELATIVE reloc for a locally defined
+ // STT_GNU_IFUNC symbol. This makes a function
+ // address in a PIE executable match the address in a
+ // shared library that it links against.
+ Reloc_section* rela_dyn =
+ target->rela_irelative_section(layout);
+ unsigned int r_type = elfcpp::R_X86_64_IRELATIVE;
+ rela_dyn->add_symbolless_global_addend(gsym, r_type,
+ output_section, object,
+ data_shndx,
+ reloc.get_r_offset(),
+ reloc.get_r_addend());
+ }
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());
+ 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);
+ this->check_non_pic(object, r_type, gsym);
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.
- int flags = Symbol::NON_PIC_REF;
- if (gsym->is_func())
- flags |= Symbol::FUNCTION_CALL;
- if (gsym->needs_dynamic_reloc(flags))
+ if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
{
if (gsym->may_need_copy_reloc())
{
}
else
{
- this->check_non_pic(object, r_type);
+ this->check_non_pic(object, r_type, gsym);
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_TYPE_STANDARD);
+ {
+ // For a STT_GNU_IFUNC symbol we want the PLT address.
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC)
+ got->add_global_plt(gsym, GOT_TYPE_STANDARD);
+ else
+ 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())
+
+ // Use a GLOB_DAT rather than a RELATIVE reloc if:
+ //
+ // 1) The symbol may be defined in some other module.
+ //
+ // 2) We are building a shared library and this is a
+ // protected symbol; using GLOB_DAT means that the dynamic
+ // linker can use the address of the PLT in the main
+ // executable when appropriate so that function address
+ // comparisons work.
+ //
+ // 3) This is a STT_GNU_IFUNC symbol in position dependent
+ // code, again so that function address comparisons work.
+ if (gsym->is_from_dynobj()
+ || gsym->is_undefined()
+ || gsym->is_preemptible()
+ || (gsym->visibility() == elfcpp::STV_PROTECTED
+ && parameters->options().shared())
+ || (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && parameters->options().output_is_position_independent()))
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 a STT_GNU_IFUNC symbol we want to write the PLT
+ // offset into the GOT, so that function pointer
+ // comparisons work correctly.
+ bool is_new;
+ if (gsym->type() != elfcpp::STT_GNU_IFUNC)
+ is_new = got->add_global(gsym, GOT_TYPE_STANDARD);
+ else
+ {
+ is_new = got->add_global_plt(gsym, GOT_TYPE_STANDARD);
+ // Tell the dynamic linker to use the PLT address
+ // when resolving relocations.
+ if (gsym->is_from_dynobj()
+ && !parameters->options().shared())
+ gsym->set_needs_dynsym_value();
+ }
+ if (is_new)
+ {
+ unsigned int got_off = gsym->got_offset(GOT_TYPE_STANDARD);
+ rela_dyn->add_global_relative(gsym,
+ elfcpp::R_X86_64_RELATIVE,
+ got, got_off, 0);
+ }
}
}
// For GOTPLT64, we also need a PLT entry (but only if the
case elfcpp::R_X86_64_GLOB_DAT:
case elfcpp::R_X86_64_JUMP_SLOT:
case elfcpp::R_X86_64_RELATIVE:
+ case elfcpp::R_X86_64_IRELATIVE:
// These are outstanding tls relocs, which are unexpected when linking
case elfcpp::R_X86_64_TPOFF64:
case elfcpp::R_X86_64_DTPMOD64:
// the section has been created.
target->got_section(symtab, layout);
Output_data_got<64, false>* got = target->got_tlsdesc_section();
- Reloc_section *rt = target->rela_tlsdesc_section(layout);
+ Reloc_section* rt = target->rela_tlsdesc_section(layout);
got->add_global_pair_with_rela(gsym, GOT_TYPE_TLS_DESC, rt,
elfcpp::R_X86_64_TLSDESC, 0);
}
void
Target_x86_64::gc_process_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
void
Target_x86_64::scan_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
uint64_t data_size = this->got_plt_->current_data_size();
symtab->get_sized_symbol<64>(sym)->set_symsize(data_size);
}
+
+ if (parameters->doing_static_link()
+ && (this->plt_ == NULL || !this->plt_->has_irelative_section()))
+ {
+ // If linking statically, make sure that the __rela_iplt symbols
+ // were defined if necessary, even if we didn't create a PLT.
+ static const Define_symbol_in_segment syms[] =
+ {
+ {
+ "__rela_iplt_start", // name
+ elfcpp::PT_LOAD, // segment_type
+ elfcpp::PF_W, // segment_flags_set
+ elfcpp::PF(0), // segment_flags_clear
+ 0, // value
+ 0, // size
+ elfcpp::STT_NOTYPE, // type
+ elfcpp::STB_GLOBAL, // binding
+ elfcpp::STV_HIDDEN, // visibility
+ 0, // nonvis
+ Symbol::SEGMENT_START, // offset_from_base
+ true // only_if_ref
+ },
+ {
+ "__rela_iplt_end", // name
+ elfcpp::PT_LOAD, // segment_type
+ elfcpp::PF_W, // segment_flags_set
+ elfcpp::PF(0), // segment_flags_clear
+ 0, // value
+ 0, // size
+ elfcpp::STT_NOTYPE, // type
+ elfcpp::STB_GLOBAL, // binding
+ elfcpp::STV_HIDDEN, // visibility
+ 0, // nonvis
+ Symbol::SEGMENT_START, // offset_from_base
+ true // only_if_ref
+ }
+ };
+
+ symtab->define_symbols(layout, 2, syms,
+ layout->script_options()->saw_sections_clause());
+ }
}
// Perform a relocation.
}
}
- // Pick the value to use for symbols defined in shared objects.
+ const Sized_relobj_file<64, false>* object = relinfo->object;
+
+ // Pick the value to use for symbols defined in the PLT.
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))
+ && gsym->use_plt_offset(Scan::get_reference_flags(r_type)))
{
- symval.set_output_value(target->plt_section()->address()
+ symval.set_output_value(target->plt_address_for_global(gsym)
+ gsym->plt_offset());
psymval = &symval;
}
+ else if (gsym == NULL && psymval->is_ifunc_symbol())
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
+ if (object->local_has_plt_offset(r_sym))
+ {
+ symval.set_output_value(target->plt_address_for_local(object, r_sym)
+ + object->local_plt_offset(r_sym));
+ 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.
case elfcpp::R_X86_64_GLOB_DAT:
case elfcpp::R_X86_64_JUMP_SLOT:
case elfcpp::R_X86_64_RELATIVE:
+ case elfcpp::R_X86_64_IRELATIVE:
// These are outstanding tls relocs, which are unexpected when linking
case elfcpp::R_X86_64_TPOFF64:
case elfcpp::R_X86_64_DTPMOD64:
{
Output_segment* tls_segment = relinfo->layout->tls_segment();
- const Sized_relobj<64, false>* object = relinfo->object;
+ const Sized_relobj_file<64, false>* object = relinfo->object;
const elfcpp::Elf_Xword addend = rela.get_r_addend();
+ elfcpp::Shdr<64, false> data_shdr(relinfo->data_shdr);
+ bool is_executable = (data_shdr.get_sh_flags() & elfcpp::SHF_EXECINSTR) != 0;
elfcpp::Elf_types<64>::Elf_Addr value = psymval->value(relinfo->object, 0);
const bool is_final = (gsym == NULL
? !parameters->options().shared()
: gsym->final_value_is_known());
- const tls::Tls_optimization optimized_type
+ 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 (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
+ {
+ // If this code sequence is used in a non-executable section,
+ // we will not optimize the R_X86_64_DTPOFF32/64 relocation,
+ // on the assumption that it's being used by itself in a debug
+ // section. Therefore, in the unlikely event that the code
+ // sequence appears in a non-executable section, we simply
+ // leave it unoptimized.
+ optimized_type = tls::TLSOPT_NONE;
+ }
if (optimized_type == tls::TLSOPT_TO_LE)
{
- gold_assert(tls_segment != NULL);
+ if (tls_segment == NULL)
+ {
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
+ }
this->tls_gd_to_le(relinfo, relnum, tls_segment,
rela, r_type, value, view,
view_size);
}
if (optimized_type == tls::TLSOPT_TO_IE)
{
- gold_assert(tls_segment != NULL);
+ if (tls_segment == NULL)
+ {
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
+ }
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);
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 (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
+ {
+ // See above comment for R_X86_64_TLSGD.
+ optimized_type = tls::TLSOPT_NONE;
+ }
if (optimized_type == tls::TLSOPT_TO_LE)
{
- gold_assert(tls_segment != NULL);
+ if (tls_segment == NULL)
+ {
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
+ }
this->tls_desc_gd_to_le(relinfo, relnum, tls_segment,
rela, r_type, value, view,
view_size);
}
if (optimized_type == tls::TLSOPT_TO_IE)
{
- gold_assert(tls_segment != NULL);
+ if (tls_segment == NULL)
+ {
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
+ }
value = target->got_plt_section()->address() + got_offset;
this->tls_desc_gd_to_ie(relinfo, relnum, tls_segment,
rela, r_type, value, view, address,
break;
case elfcpp::R_X86_64_TLSLD: // Local-dynamic
- this->saw_tls_block_reloc_ = true;
+ if (!is_executable && optimized_type == tls::TLSOPT_TO_LE)
+ {
+ // See above comment for R_X86_64_TLSGD.
+ optimized_type = tls::TLSOPT_NONE;
+ }
if (optimized_type == tls::TLSOPT_TO_LE)
{
- gold_assert(tls_segment != NULL);
+ if (tls_segment == NULL)
+ {
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
+ }
this->tls_ld_to_le(relinfo, relnum, tls_segment, rela, r_type,
value, view, view_size);
break;
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_)
+ // This relocation type is used in debugging information.
+ // In that case we need to not optimize the value. If the
+ // section is not executable, then we assume we should not
+ // optimize this reloc. See comments above for R_X86_64_TLSGD,
+ // R_X86_64_GOTPC32_TLSDESC, R_X86_64_TLSDESC_CALL, and
+ // R_X86_64_TLSLD.
+ if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
+ {
+ if (tls_segment == NULL)
{
- gold_assert(tls_segment != NULL);
- value -= tls_segment->memsz();
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
}
- }
+ 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_)
+ // See R_X86_64_DTPOFF32, just above, for why we check for is_executable.
+ if (optimized_type == tls::TLSOPT_TO_LE && is_executable)
+ {
+ if (tls_segment == NULL)
{
- gold_assert(tls_segment != NULL);
- value -= tls_segment->memsz();
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
}
- }
+ 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);
+ if (tls_segment == NULL)
+ {
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
+ }
Target_x86_64::Relocate::tls_ie_to_le(relinfo, relnum, tls_segment,
rela, r_type, value, view,
view_size);
break;
case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ if (tls_segment == NULL)
+ {
+ gold_assert(parameters->errors()->error_count() > 0
+ || issue_undefined_symbol_error(gsym));
+ return;
+ }
value -= tls_segment->memsz();
Relocate_functions<64, false>::rela32(view, value, addend);
break;
reloc_symbol_changes);
}
+// Apply an incremental relocation. Incremental relocations always refer
+// to global symbols.
+
+void
+Target_x86_64::apply_relocation(
+ const Relocate_info<64, false>* relinfo,
+ elfcpp::Elf_types<64>::Elf_Addr r_offset,
+ unsigned int r_type,
+ elfcpp::Elf_types<64>::Elf_Swxword r_addend,
+ const Symbol* gsym,
+ unsigned char* view,
+ elfcpp::Elf_types<64>::Elf_Addr address,
+ section_size_type view_size)
+{
+ gold::apply_relocation<64, false, Target_x86_64, Target_x86_64::Relocate>(
+ relinfo,
+ this,
+ r_offset,
+ r_type,
+ r_addend,
+ gsym,
+ view,
+ address,
+ view_size);
+}
+
// Return the size of a relocation while scanning during a relocatable
// link.
case elfcpp::R_X86_64_GLOB_DAT:
case elfcpp::R_X86_64_JUMP_SLOT:
case elfcpp::R_X86_64_RELATIVE:
+ case elfcpp::R_X86_64_IRELATIVE:
// These are outstanding tls relocs, which are unexpected when linking
case elfcpp::R_X86_64_TPOFF64:
case elfcpp::R_X86_64_DTPMOD64:
void
Target_x86_64::scan_relocatable_relocs(Symbol_table* symtab,
Layout* layout,
- Sized_relobj<64, false>* object,
+ Sized_relobj_file<64, false>* object,
unsigned int data_shndx,
unsigned int sh_type,
const unsigned char* prelocs,
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 this->plt_address_for_global(gsym) + gsym->plt_offset();
}
// Return a string used to fill a code section with nops to take up
return psymval->value(ti.object, 0);
}
+// Return the value to use for the base of a DW_EH_PE_datarel offset
+// in an FDE. Solaris and SVR4 use DW_EH_PE_datarel because their
+// assembler can not write out the difference between two labels in
+// different sections, so instead of using a pc-relative value they
+// use an offset from the GOT.
+
+uint64_t
+Target_x86_64::do_ehframe_datarel_base() const
+{
+ gold_assert(this->global_offset_table_ != NULL);
+ Symbol* sym = this->global_offset_table_;
+ Sized_symbol<64>* ssym = static_cast<Sized_symbol<64>*>(sym);
+ return ssym->value();
+}
+
// FNOFFSET in section SHNDX in OBJECT is the start of a function
-// compiled with -fstack-split. The function calls non-stack-split
+// compiled with -fsplit-stack. The function calls non-split-stack
// code. We have to change the function so that it always ensures
// that it has enough stack space to run some random function.
public:
Target_selector_x86_64()
: Target_selector_freebsd(elfcpp::EM_X86_64, 64, false, "elf64-x86-64",
- "elf64-x86-64-freebsd")
+ "elf64-x86-64-freebsd", "elf_x86_64")
{ }
Target*
projects / deliverable / binutils-gdb.git / blobdiff