// x86_64.cc -- x86_64 target support for gold.
-// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
-// Free Software Foundation, Inc.
+// Copyright (C) 2006-2020 Free Software Foundation, Inc.
// Written by Ian Lance Taylor <iant@google.com>.
// This file is part of gold.
using namespace gold;
+// A class to handle the .got.plt section.
+
+class Output_data_got_plt_x86_64 : public Output_section_data_build
+{
+ public:
+ Output_data_got_plt_x86_64(Layout* layout)
+ : Output_section_data_build(8),
+ layout_(layout)
+ { }
+
+ Output_data_got_plt_x86_64(Layout* layout, off_t data_size)
+ : Output_section_data_build(data_size, 8),
+ layout_(layout)
+ { }
+
+ protected:
+ // Write out the PLT data.
+ void
+ do_write(Output_file*);
+
+ // Write to a map file.
+ void
+ do_print_to_mapfile(Mapfile* mapfile) const
+ { mapfile->print_output_data(this, "** GOT PLT"); }
+
+ private:
+ // A pointer to the Layout class, so that we can find the .dynamic
+ // section when we write out the GOT PLT section.
+ Layout* layout_;
+};
+
// A class to handle the PLT data.
// This is an abstract base class that handles most of the linker details
// but does not know the actual contents of PLT entries. The derived
Output_data_plt_x86_64(Layout* layout, uint64_t addralign,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative)
- : Output_section_data(addralign), layout_(layout), tlsdesc_rel_(NULL),
+ : Output_section_data(addralign), 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_()
Output_data_plt_x86_64(Layout* layout, uint64_t plt_entry_size,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative,
unsigned int plt_count)
: Output_section_data((plt_count + 1) * plt_entry_size,
plt_entry_size, false),
- layout_(layout), tlsdesc_rel_(NULL), irelative_rel_(NULL), got_(got),
+ 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_()
{
has_irelative_section() const
{ return this->irelative_rel_ != NULL; }
- // Return the number of PLT entries.
+ // Get count of regular PLT entries.
+ unsigned int
+ regular_count() const
+ { return this->count_; }
+
+ // Return the total number of PLT entries.
unsigned int
entry_count() const
{ return this->count_ + this->irelative_count_; }
// Return the PLT address to use for a global symbol.
uint64_t
- address_for_global(const Symbol*);
+ address_for_global(const Symbol* sym)
+ { return do_address_for_global(sym); }
// Return the PLT address to use for a local symbol.
uint64_t
- address_for_local(const Relobj*, unsigned int symndx);
+ address_for_local(const Relobj* obj, unsigned int symndx)
+ { return do_address_for_local(obj, symndx); }
// Add .eh_frame information for the PLT.
void
{ this->do_add_eh_frame(layout); }
protected:
+ Output_data_got<64, false>*
+ got() const
+ { return this->got_; }
+
+ Output_data_got_plt_x86_64*
+ got_plt() const
+ { return this->got_plt_; }
+
+ Output_data_space*
+ got_irelative() const
+ { return this->got_irelative_; }
+
// Fill in the first PLT entry.
void
fill_first_plt_entry(unsigned char* pov,
unsigned int tlsdesc_got_offset,
unsigned int plt_offset) = 0;
+ // Return the PLT address to use for a global symbol.
+ virtual uint64_t
+ do_address_for_global(const Symbol* sym);
+
+ // Return the PLT address to use for a local symbol.
+ virtual uint64_t
+ do_address_for_local(const Relobj* obj, unsigned int symndx);
+
virtual void
do_add_eh_frame(Layout* layout) = 0;
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
// The .got section.
Output_data_got<64, false>* got_;
// The .got.plt section.
- Output_data_space* got_plt_;
+ Output_data_got_plt_x86_64* got_plt_;
// The part of the .got.plt section used for IRELATIVE relocs.
Output_data_space* got_irelative_;
// The number of PLT entries.
public:
Output_data_plt_x86_64_standard(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative)
: Output_data_plt_x86_64<size>(layout, plt_entry_size,
got, got_plt, got_irelative)
Output_data_plt_x86_64_standard(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative,
unsigned int plt_count)
: Output_data_plt_x86_64<size>(layout, plt_entry_size,
static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
};
+class Output_data_plt_x86_64_bnd : public Output_data_plt_x86_64<64>
+{
+ public:
+ Output_data_plt_x86_64_bnd(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative)
+ : Output_data_plt_x86_64<64>(layout, plt_entry_size,
+ got, got_plt, got_irelative),
+ aplt_offset_(0)
+ { }
+
+ Output_data_plt_x86_64_bnd(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative,
+ unsigned int plt_count)
+ : Output_data_plt_x86_64<64>(layout, plt_entry_size,
+ got, got_plt, got_irelative,
+ plt_count),
+ aplt_offset_(0)
+ { }
+
+ protected:
+ virtual unsigned int
+ do_get_plt_entry_size() const
+ { return plt_entry_size; }
+
+ // Return the PLT address to use for a global symbol.
+ uint64_t
+ do_address_for_global(const Symbol*);
+
+ // Return the PLT address to use for a local symbol.
+ uint64_t
+ do_address_for_local(const Relobj*, unsigned int symndx);
+
+ virtual void
+ do_add_eh_frame(Layout* layout)
+ {
+ layout->add_eh_frame_for_plt(this,
+ this->plt_eh_frame_cie,
+ this->plt_eh_frame_cie_size,
+ plt_eh_frame_fde,
+ plt_eh_frame_fde_size);
+ }
+
+ virtual void
+ do_fill_first_plt_entry(unsigned char* pov,
+ elfcpp::Elf_types<64>::Elf_Addr got_addr,
+ elfcpp::Elf_types<64>::Elf_Addr plt_addr);
+
+ virtual unsigned int
+ do_fill_plt_entry(unsigned char* pov,
+ elfcpp::Elf_types<64>::Elf_Addr got_address,
+ elfcpp::Elf_types<64>::Elf_Addr plt_address,
+ unsigned int got_offset,
+ unsigned int plt_offset,
+ unsigned int plt_index);
+
+ virtual void
+ do_fill_tlsdesc_entry(unsigned char* pov,
+ elfcpp::Elf_types<64>::Elf_Addr got_address,
+ elfcpp::Elf_types<64>::Elf_Addr plt_address,
+ elfcpp::Elf_types<64>::Elf_Addr got_base,
+ unsigned int tlsdesc_got_offset,
+ unsigned int plt_offset);
+
+ void
+ fill_aplt_entry(unsigned char* pov,
+ elfcpp::Elf_types<64>::Elf_Addr got_address,
+ elfcpp::Elf_types<64>::Elf_Addr plt_address,
+ unsigned int got_offset,
+ unsigned int plt_offset,
+ unsigned int plt_index);
+
+ private:
+ // Set the final size.
+ void
+ set_final_data_size();
+
+ // Write out the BND PLT data.
+ void
+ do_write(Output_file*);
+
+ // Offset of the Additional PLT (if using -z bndplt).
+ unsigned int aplt_offset_;
+
+ // The size of an entry in the PLT.
+ static const int plt_entry_size = 16;
+
+ // The size of an entry in the additional PLT.
+ static const int aplt_entry_size = 8;
+
+ // 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];
+
+ // Entries in the additional PLT.
+ static const unsigned char aplt_entry[aplt_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_fde_size = 32;
+ static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
+};
+
+// We use this PLT when Indirect Branch Tracking (IBT) is enabled.
+
+template <int size>
+class Output_data_plt_x86_64_ibt : public Output_data_plt_x86_64<size>
+{
+ public:
+ Output_data_plt_x86_64_ibt(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative)
+ : Output_data_plt_x86_64<size>(layout, plt_entry_size,
+ got, got_plt, got_irelative),
+ aplt_offset_(0)
+ { }
+
+ Output_data_plt_x86_64_ibt(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative,
+ unsigned int plt_count)
+ : Output_data_plt_x86_64<size>(layout, plt_entry_size,
+ got, got_plt, got_irelative,
+ plt_count),
+ aplt_offset_(0)
+ { }
+
+ protected:
+ virtual unsigned int
+ do_get_plt_entry_size() const
+ { return plt_entry_size; }
+
+ // Return the PLT address to use for a global symbol.
+ uint64_t
+ do_address_for_global(const Symbol*);
+
+ // Return the PLT address to use for a local symbol.
+ uint64_t
+ do_address_for_local(const Relobj*, unsigned int symndx);
+
+ virtual void
+ do_add_eh_frame(Layout* layout)
+ {
+ layout->add_eh_frame_for_plt(this,
+ this->plt_eh_frame_cie,
+ this->plt_eh_frame_cie_size,
+ plt_eh_frame_fde,
+ plt_eh_frame_fde_size);
+ }
+
+ virtual void
+ do_fill_first_plt_entry(unsigned char* pov,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_addr,
+ typename elfcpp::Elf_types<size>::Elf_Addr plt_addr);
+
+ virtual unsigned int
+ do_fill_plt_entry(unsigned char* pov,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_address,
+ typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
+ unsigned int got_offset,
+ unsigned int plt_offset,
+ unsigned int plt_index);
+
+ virtual void
+ do_fill_tlsdesc_entry(unsigned char* pov,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_address,
+ typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_base,
+ unsigned int tlsdesc_got_offset,
+ unsigned int plt_offset);
+
+ void
+ fill_aplt_entry(unsigned char* pov,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_address,
+ typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
+ unsigned int got_offset,
+ unsigned int plt_offset,
+ unsigned int plt_index);
+
+ private:
+ // Set the final size.
+ void
+ set_final_data_size();
+
+ // Write out the BND PLT data.
+ void
+ do_write(Output_file*);
+
+ // Offset of the Additional PLT (if using -z bndplt).
+ unsigned int aplt_offset_;
+
+ // The size of an entry in the PLT.
+ static const int plt_entry_size = 16;
+
+ // The size of an entry in the additional PLT.
+ static const int aplt_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];
+
+ // Entries in the additional PLT.
+ static const unsigned char aplt_entry[aplt_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_fde_size = 32;
+ static const unsigned char plt_eh_frame_fde[plt_eh_frame_fde_size];
+};
+
+template<int size>
+class Lazy_view
+{
+ public:
+ Lazy_view(Sized_relobj_file<size, false>* object, unsigned int data_shndx)
+ : object_(object), data_shndx_(data_shndx), view_(NULL), view_size_(0)
+ { }
+
+ inline unsigned char
+ operator[](size_t offset)
+ {
+ if (this->view_ == NULL)
+ this->view_ = this->object_->section_contents(this->data_shndx_,
+ &this->view_size_,
+ true);
+ if (offset >= this->view_size_)
+ return 0;
+ return this->view_[offset];
+ }
+
+ private:
+ Sized_relobj_file<size, false>* object_;
+ unsigned int data_shndx_;
+ const unsigned char* view_;
+ section_size_type view_size_;
+};
+
// The x86_64 target class.
// See the ABI at
// http://www.x86-64.org/documentation/abi.pdf
got_tlsdesc_(NULL), global_offset_table_(NULL), rela_dyn_(NULL),
rela_irelative_(NULL), copy_relocs_(elfcpp::R_X86_64_COPY),
got_mod_index_offset_(-1U), tlsdesc_reloc_info_(),
- tls_base_symbol_defined_(false)
+ tls_base_symbol_defined_(false), isa_1_used_(0), isa_1_needed_(0),
+ feature_1_(0), object_isa_1_used_(0), object_feature_1_(0),
+ seen_first_object_(false)
{ }
// Hook for a new output section.
const unsigned char* plocal_symbols,
Relocatable_relocs*);
+ // Scan the relocs for --emit-relocs.
+ void
+ emit_relocs_scan(Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<size, 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_syms,
+ Relocatable_relocs* rr);
+
// Emit relocations for a section.
void
relocate_relocs(
size_t reloc_count,
Output_section* output_section,
typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
- const Relocatable_relocs*,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
section_size_type view_size,
// 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.
+ // pie binaries, safe ICF cannot be done by looking at only relocation
+ // types, and for certain cases (e.g. R_X86_64_PC32), the instruction
+ // opcode is checked as well to distinguish a function call from taking
+ // a function's pointer.
bool
do_can_check_for_function_pointers() const
- { return !parameters->options().pie(); }
+ { return true; }
// Return the base for a DW_EH_PE_datarel encoding.
uint64_t
void
do_calls_non_split(Relobj* object, unsigned int shndx,
section_offset_type fnoffset, section_size_type fnsize,
+ const unsigned char* prelocs, size_t reloc_count,
unsigned char* view, section_size_type view_size,
std::string* from, std::string* to) const;
unsigned int
plt_entry_size() const;
+ // Return the size of each GOT entry.
+ unsigned int
+ got_entry_size() const
+ { return 8; };
+
// Create the GOT section for an incremental update.
Output_data_got_base*
init_got_plt_for_update(Symbol_table* symtab,
Output_data_plt_x86_64<size>*
make_data_plt(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative)
{
return this->do_make_data_plt(layout, got, got_plt, got_irelative);
Output_data_plt_x86_64<size>*
make_data_plt(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative,
unsigned int plt_count)
{
virtual Output_data_plt_x86_64<size>*
do_make_data_plt(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
- Output_data_space* got_irelative)
- {
- return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
- got_irelative);
- }
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative);
virtual Output_data_plt_x86_64<size>*
do_make_data_plt(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative,
- unsigned int plt_count)
- {
- return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
- got_irelative,
- plt_count);
- }
+ unsigned int plt_count);
private:
// The class which scans relocations.
check_non_pic(Relobj*, unsigned int r_type, Symbol*);
inline bool
- possible_function_pointer_reloc(unsigned int r_type);
+ possible_function_pointer_reloc(Sized_relobj_file<size, false>* src_obj,
+ unsigned int src_indx,
+ unsigned int r_offset,
+ unsigned int r_type);
bool
reloc_needs_plt_for_ifunc(Sized_relobj_file<size, false>*,
// Do a relocation. Return false if the caller should not issue
// any warnings about this relocation.
inline bool
- relocate(const Relocate_info<size, false>*, Target_x86_64*,
- Output_section*,
- size_t relnum, const elfcpp::Rela<size, false>&,
- unsigned int r_type, const Sized_symbol<size>*,
- const Symbol_value<size>*,
+ relocate(const Relocate_info<size, false>*, unsigned int,
+ Target_x86_64*, Output_section*, size_t, const unsigned char*,
+ const Sized_symbol<size>*, const Symbol_value<size>*,
unsigned char*, typename elfcpp::Elf_types<size>::Elf_Addr,
section_size_type);
// Do a TLS General-Dynamic to Initial-Exec transition.
inline void
tls_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
- Output_segment* tls_segment,
const elfcpp::Rela<size, false>&, unsigned int r_type,
typename elfcpp::Elf_types<size>::Elf_Addr value,
unsigned char* view,
// Do a TLSDESC-style General-Dynamic to Initial-Exec transition.
inline void
tls_desc_gd_to_ie(const Relocate_info<size, false>*, size_t relnum,
- Output_segment* tls_segment,
const elfcpp::Rela<size, false>&, unsigned int r_type,
typename elfcpp::Elf_types<size>::Elf_Addr value,
unsigned char* view,
bool skip_call_tls_get_addr_;
};
- // A class which returns the size required for a relocation type,
- // used while scanning relocs during a relocatable link.
- class Relocatable_size_for_reloc
+ // Check if relocation against this symbol is a candidate for
+ // conversion from
+ // mov foo@GOTPCREL(%rip), %reg
+ // to lea foo(%rip), %reg.
+ template<class View_type>
+ static inline bool
+ can_convert_mov_to_lea(const Symbol* gsym, unsigned int r_type,
+ size_t r_offset, View_type* view)
{
- public:
- unsigned int
- get_size_for_reloc(unsigned int, Relobj*);
- };
+ gold_assert(gsym != NULL);
+ // We cannot do the conversion unless it's one of these relocations.
+ if (r_type != elfcpp::R_X86_64_GOTPCREL
+ && r_type != elfcpp::R_X86_64_GOTPCRELX
+ && r_type != elfcpp::R_X86_64_REX_GOTPCRELX)
+ return false;
+ // We cannot convert references to IFUNC symbols, or to symbols that
+ // are not local to the current module.
+ // We can't do predefined symbols because they may become undefined
+ // (e.g., __ehdr_start when the headers aren't mapped to a segment).
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ || gsym->is_undefined()
+ || gsym->is_predefined()
+ || gsym->is_from_dynobj()
+ || gsym->is_preemptible())
+ return false;
+ // If we are building a shared object and the symbol is protected, we may
+ // need to go through the GOT.
+ if (parameters->options().shared()
+ && gsym->visibility() == elfcpp::STV_PROTECTED)
+ return false;
+ // We cannot convert references to the _DYNAMIC symbol.
+ if (strcmp(gsym->name(), "_DYNAMIC") == 0)
+ return false;
+ // Check for a MOV opcode.
+ return (*view)[r_offset - 2] == 0x8b;
+ }
+
+ // Convert
+ // callq *foo@GOTPCRELX(%rip) to
+ // addr32 callq foo
+ // and jmpq *foo@GOTPCRELX(%rip) to
+ // jmpq foo
+ // nop
+ template<class View_type>
+ static inline bool
+ can_convert_callq_to_direct(const Symbol* gsym, unsigned int r_type,
+ size_t r_offset, View_type* view)
+ {
+ gold_assert(gsym != NULL);
+ // We cannot do the conversion unless it's a GOTPCRELX relocation.
+ if (r_type != elfcpp::R_X86_64_GOTPCRELX)
+ return false;
+ // We cannot convert references to IFUNC symbols, or to symbols that
+ // are not local to the current module.
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ || gsym->is_undefined ()
+ || gsym->is_from_dynobj()
+ || gsym->is_preemptible())
+ return false;
+ // Check for a CALLQ or JMPQ opcode.
+ return ((*view)[r_offset - 2] == 0xff
+ && ((*view)[r_offset - 1] == 0x15
+ || (*view)[r_offset - 1] == 0x25));
+ }
// Adjust TLS relocation type based on the options and whether this
// is a local symbol.
got_section(Symbol_table*, Layout*);
// Get the GOT PLT section.
- Output_data_space*
+ Output_data_got_plt_x86_64*
got_plt_section() const
{
gold_assert(this->got_plt_ != NULL);
unsigned int shndx, Output_section* output_section,
Symbol* sym, const elfcpp::Rela<size, false>& reloc)
{
+ unsigned int r_type = elfcpp::elf_r_type<size>(reloc.get_r_info());
this->copy_relocs_.copy_reloc(symtab, layout,
symtab->get_sized_symbol<size>(sym),
object, shndx, output_section,
- reloc, this->rela_dyn_section(layout));
+ r_type, reloc.get_r_offset(),
+ reloc.get_r_addend(),
+ this->rela_dyn_section(layout));
}
+ // Record a target-specific program property in the .note.gnu.property
+ // section.
+ void
+ record_gnu_property(unsigned int, unsigned int, size_t,
+ const unsigned char*, const Object*);
+
+ // Merge the target-specific program properties from the current object.
+ void
+ merge_gnu_properties(const Object*);
+
+ // Finalize the target-specific program properties and add them back to
+ // the layout.
+ void
+ do_finalize_gnu_properties(Layout*) const;
+
// Information about this specific target which we pass to the
// general Target structure.
static const Target::Target_info x86_64_info;
// The PLT section.
Output_data_plt_x86_64<size>* plt_;
// The GOT PLT section.
- Output_data_space* got_plt_;
+ Output_data_got_plt_x86_64* got_plt_;
// The GOT section for IRELATIVE relocations.
Output_data_space* got_irelative_;
// The GOT section for TLSDESC relocations.
std::vector<Tlsdesc_info> tlsdesc_reloc_info_;
// True if the _TLS_MODULE_BASE_ symbol has been defined.
bool tls_base_symbol_defined_;
+ // Target-specific program properties, from .note.gnu.property section.
+ // Each bit represents a specific feature.
+ uint32_t isa_1_used_;
+ uint32_t isa_1_needed_;
+ uint32_t feature_1_;
+ // Target-specific properties from the current object.
+ // These bits get ORed into ISA_1_USED_ after all properties for the object
+ // have been processed. But if either is all zeroes (as when the property
+ // is absent from an object), the result should be all zeroes.
+ // (See PR ld/23486.)
+ uint32_t object_isa_1_used_;
+ // These bits get ANDed into FEATURE_1_ after all properties for the object
+ // have been processed.
+ uint32_t object_feature_1_;
+ // Whether we have seen our first object, for use in initializing FEATURE_1_.
+ bool seen_first_object_;
};
template<>
elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
NULL, // attributes_section
NULL, // attributes_vendor
- "_start" // entry_symbol_name
+ "_start", // entry_symbol_name
+ 32, // hash_entry_size
+ elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
};
template<>
elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
NULL, // attributes_section
NULL, // attributes_vendor
- "_start" // entry_symbol_name
+ "_start", // entry_symbol_name
+ 32, // hash_entry_size
+ elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
};
// This is called when a new output section is created. This is where
| elfcpp::SHF_WRITE),
this->got_, got_order, true);
- this->got_plt_ = new Output_data_space(8, "** GOT PLT");
+ this->got_plt_ = new Output_data_got_plt_x86_64(layout);
layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
return this->rela_irelative_;
}
-// Initialize the PLT section.
-
-template<int size>
-void
-Output_data_plt_x86_64<size>::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);
-}
-
+// Record a target-specific program property from the .note.gnu.property
+// section.
template<int size>
void
-Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
+Target_x86_64<size>::record_gnu_property(
+ unsigned int, unsigned int pr_type,
+ size_t pr_datasz, const unsigned char* pr_data,
+ const Object* object)
{
- os->set_entsize(this->get_plt_entry_size());
-}
-
-// Add an entry to the PLT.
+ uint32_t val = 0;
-template<int size>
-void
-Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
- Symbol* gsym)
+ switch (pr_type)
+ {
+ case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
+ case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
+ case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
+ if (pr_datasz != 4)
+ {
+ gold_warning(_("%s: corrupt .note.gnu.property section "
+ "(pr_datasz for property %d is not 4)"),
+ object->name().c_str(), pr_type);
+ return;
+ }
+ val = elfcpp::Swap<32, false>::readval(pr_data);
+ break;
+ default:
+ gold_warning(_("%s: unknown program property type 0x%x "
+ "in .note.gnu.property section"),
+ object->name().c_str(), pr_type);
+ break;
+ }
+
+ switch (pr_type)
+ {
+ case elfcpp::GNU_PROPERTY_X86_ISA_1_USED:
+ this->object_isa_1_used_ |= val;
+ break;
+ case elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED:
+ this->isa_1_needed_ |= val;
+ break;
+ case elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND:
+ // If we see multiple feature props in one object, OR them together.
+ this->object_feature_1_ |= val;
+ break;
+ }
+}
+
+// Merge the target-specific program properties from the current object.
+template<int size>
+void
+Target_x86_64<size>::merge_gnu_properties(const Object*)
+{
+ if (this->seen_first_object_)
+ {
+ // If any object is missing the ISA_1_USED property, we must omit
+ // it from the output file.
+ if (this->object_isa_1_used_ == 0)
+ this->isa_1_used_ = 0;
+ else if (this->isa_1_used_ != 0)
+ this->isa_1_used_ |= this->object_isa_1_used_;
+ this->feature_1_ &= this->object_feature_1_;
+ }
+ else
+ {
+ this->isa_1_used_ = this->object_isa_1_used_;
+ this->feature_1_ = this->object_feature_1_;
+ this->seen_first_object_ = true;
+ }
+ this->object_isa_1_used_ = 0;
+ this->object_feature_1_ = 0;
+}
+
+static inline void
+add_property(Layout* layout, unsigned int pr_type, uint32_t val)
+{
+ unsigned char buf[4];
+ elfcpp::Swap<32, false>::writeval(buf, val);
+ layout->add_gnu_property(elfcpp::NT_GNU_PROPERTY_TYPE_0, pr_type, 4, buf);
+}
+
+// Finalize the target-specific program properties and add them back to
+// the layout.
+template<int size>
+void
+Target_x86_64<size>::do_finalize_gnu_properties(Layout* layout) const
+{
+ if (this->isa_1_used_ != 0)
+ add_property(layout, elfcpp::GNU_PROPERTY_X86_ISA_1_USED,
+ this->isa_1_used_);
+ if (this->isa_1_needed_ != 0)
+ add_property(layout, elfcpp::GNU_PROPERTY_X86_ISA_1_NEEDED,
+ this->isa_1_needed_);
+ if (this->feature_1_ != 0)
+ add_property(layout, elfcpp::GNU_PROPERTY_X86_FEATURE_1_AND,
+ this->feature_1_);
+}
+
+// Write the first three reserved words of the .got.plt section.
+// The remainder of the section is written while writing the PLT
+// in Output_data_plt_i386::do_write.
+
+void
+Output_data_got_plt_x86_64::do_write(Output_file* of)
+{
+ // 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.
+ const off_t got_file_offset = this->offset();
+ gold_assert(this->data_size() >= 24);
+ unsigned char* const got_view = of->get_output_view(got_file_offset, 24);
+ Output_section* dynamic = this->layout_->dynamic_section();
+ uint64_t dynamic_addr = dynamic == NULL ? 0 : dynamic->address();
+ elfcpp::Swap<64, false>::writeval(got_view, dynamic_addr);
+ memset(got_view + 8, 0, 16);
+ of->write_output_view(got_file_offset, 24, got_view);
+}
+
+// Initialize the PLT section.
+
+template<int size>
+void
+Output_data_plt_x86_64<size>::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);
+}
+
+template<int size>
+void
+Output_data_plt_x86_64<size>::do_adjust_output_section(Output_section* os)
+{
+ os->set_entsize(this->get_plt_entry_size());
+}
+
+// Add an entry to the PLT.
+
+template<int size>
+void
+Output_data_plt_x86_64<size>::add_entry(Symbol_table* symtab, Layout* layout,
+ Symbol* gsym)
{
gold_assert(!gsym->has_plt_offset());
unsigned int* pcount;
unsigned int offset;
unsigned int reserved;
- Output_data_space* got;
+ Output_section_data_build* got;
if (gsym->type() == elfcpp::STT_GNU_IFUNC
&& gsym->can_use_relative_reloc(false))
{
template<int size>
uint64_t
-Output_data_plt_x86_64<size>::address_for_global(const Symbol* gsym)
+Output_data_plt_x86_64<size>::do_address_for_global(const Symbol* gsym)
{
uint64_t offset = 0;
if (gsym->type() == elfcpp::STT_GNU_IFUNC
template<int size>
uint64_t
-Output_data_plt_x86_64<size>::address_for_local(const Relobj* object,
- unsigned int r_sym)
+Output_data_plt_x86_64<size>::do_address_for_local(const Relobj* object,
+ unsigned int r_sym)
{
return (this->address()
+ (this->count_ + 1) * this->get_plt_entry_size()
void
Output_data_plt_x86_64<size>::set_final_data_size()
{
- unsigned int count = this->count_ + this->irelative_count_;
+ // Number of regular and IFUNC PLT entries, plus the first entry.
+ unsigned int count = this->count_ + this->irelative_count_ + 1;
+ // Count the TLSDESC entry, if present.
if (this->has_tlsdesc_entry())
++count;
- this->set_data_size((count + 1) * this->get_plt_entry_size());
+ this->set_data_size(count * this->get_plt_entry_size());
}
// The first entry in the PLT for an executable.
unsigned int plt_offset,
unsigned int plt_index)
{
+ // Check PC-relative offset overflow in PLT entry.
+ uint64_t plt_got_pcrel_offset = (got_address + got_offset
+ - (plt_address + plt_offset + 6));
+ if (Bits<32>::has_overflow(plt_got_pcrel_offset))
+ gold_error(_("PC-relative offset overflow in PLT entry %d"),
+ plt_index + 1);
+
memcpy(pov, plt_entry, plt_entry_size);
elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
- (got_address + got_offset
- - (plt_address + plt_offset
- + 6)));
+ plt_got_pcrel_offset);
elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
elfcpp::Swap<32, false>::writeval(pov + 12,
+ 12)));
}
+// Return the APLT address to use for a global symbol (for -z bndplt).
+
+uint64_t
+Output_data_plt_x86_64_bnd::do_address_for_global(const Symbol* gsym)
+{
+ uint64_t offset = this->aplt_offset_;
+ // Convert the PLT offset into an APLT offset.
+ unsigned int plt_offset = gsym->plt_offset();
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ offset += this->regular_count() * aplt_entry_size;
+ else
+ plt_offset -= plt_entry_size;
+ plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
+ return this->address() + offset + plt_offset;
+}
+
+// Return the PLT address to use for a local symbol. These are always
+// IRELATIVE relocs.
+
+uint64_t
+Output_data_plt_x86_64_bnd::do_address_for_local(const Relobj* object,
+ unsigned int r_sym)
+{
+ // Convert the PLT offset into an APLT offset.
+ const Sized_relobj_file<64, false>* sized_relobj =
+ static_cast<const Sized_relobj_file<64, false>*>(object);
+ const Symbol_value<64>* psymval = sized_relobj->local_symbol(r_sym);
+ unsigned int plt_offset = ((object->local_plt_offset(r_sym)
+ - (psymval->is_ifunc_symbol()
+ ? 0 : plt_entry_size))
+ / (plt_entry_size / aplt_entry_size));
+ return (this->address()
+ + this->aplt_offset_
+ + this->regular_count() * aplt_entry_size
+ + plt_offset);
+}
+
+// Set the final size.
+void
+Output_data_plt_x86_64_bnd::set_final_data_size()
+{
+ // Number of regular and IFUNC PLT entries.
+ unsigned int count = this->entry_count();
+ // Count the first entry and the TLSDESC entry, if present.
+ unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
+ unsigned int plt_size = (count + extra) * plt_entry_size;
+ // Offset of the APLT.
+ this->aplt_offset_ = plt_size;
+ // Size of the APLT.
+ plt_size += count * aplt_entry_size;
+ this->set_data_size(plt_size);
+}
+
+// The first entry in the BND PLT.
+
+const unsigned char
+Output_data_plt_x86_64_bnd::first_plt_entry[plt_entry_size] =
+{
+ // From AMD64 ABI Draft 0.98, page 76
+ 0xff, 0x35, // pushq contents of memory address
+ 0, 0, 0, 0, // replaced with address of .got + 8
+ 0xf2, 0xff, 0x25, // bnd jmp indirect
+ 0, 0, 0, 0, // replaced with address of .got + 16
+ 0x0f, 0x1f, 0x00 // nop
+};
+
+void
+Output_data_plt_x86_64_bnd::do_fill_first_plt_entry(
+ unsigned char* pov,
+ elfcpp::Elf_types<64>::Elf_Addr got_address,
+ elfcpp::Elf_types<64>::Elf_Addr 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 + 9,
+ (got_address + 16
+ - (plt_address + 13)));
+}
+
+// Subsequent entries in the BND PLT.
+
+const unsigned char
+Output_data_plt_x86_64_bnd::plt_entry[plt_entry_size] =
+{
+ // From AMD64 ABI Draft 0.99.8, page 139
+ 0x68, // pushq immediate
+ 0, 0, 0, 0, // replaced with offset into relocation table
+ 0xf2, 0xe9, // bnd jmpq relative
+ 0, 0, 0, 0, // replaced with offset to start of .plt
+ 0x0f, 0x1f, 0x44, 0, 0 // nop
+};
+
+// Entries in the BND Additional PLT.
+
+const unsigned char
+Output_data_plt_x86_64_bnd::aplt_entry[aplt_entry_size] =
+{
+ // From AMD64 ABI Draft 0.99.8, page 139
+ 0xf2, 0xff, 0x25, // bnd jmpq indirect
+ 0, 0, 0, 0, // replaced with address of symbol in .got
+ 0x90, // nop
+};
+
+unsigned int
+Output_data_plt_x86_64_bnd::do_fill_plt_entry(
+ unsigned char* pov,
+ elfcpp::Elf_types<64>::Elf_Addr,
+ elfcpp::Elf_types<64>::Elf_Addr,
+ unsigned int,
+ unsigned int plt_offset,
+ unsigned int plt_index)
+{
+ memcpy(pov, plt_entry, plt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 1, plt_index);
+ elfcpp::Swap<32, false>::writeval(pov + 7, -(plt_offset + 11));
+ return 0;
+}
+
+void
+Output_data_plt_x86_64_bnd::fill_aplt_entry(
+ unsigned char* pov,
+ elfcpp::Elf_types<64>::Elf_Addr got_address,
+ elfcpp::Elf_types<64>::Elf_Addr plt_address,
+ unsigned int got_offset,
+ unsigned int plt_offset,
+ unsigned int plt_index)
+{
+ // Check PC-relative offset overflow in PLT entry.
+ uint64_t plt_got_pcrel_offset = (got_address + got_offset
+ - (plt_address + plt_offset + 7));
+ if (Bits<32>::has_overflow(plt_got_pcrel_offset))
+ gold_error(_("PC-relative offset overflow in APLT entry %d"),
+ plt_index + 1);
+
+ memcpy(pov, aplt_entry, aplt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 3, plt_got_pcrel_offset);
+}
+
+// The reserved TLSDESC entry in the PLT for an executable.
+
+const unsigned char
+Output_data_plt_x86_64_bnd::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)
+ 0xf2, 0xff, 0x25, // jmpq *y(%rip)
+ 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
+ 0x0f, 0x1f, 0 // nop
+};
+
+void
+Output_data_plt_x86_64_bnd::do_fill_tlsdesc_entry(
+ unsigned char* pov,
+ elfcpp::Elf_types<64>::Elf_Addr got_address,
+ elfcpp::Elf_types<64>::Elf_Addr plt_address,
+ elfcpp::Elf_types<64>::Elf_Addr got_base,
+ unsigned int tlsdesc_got_offset,
+ unsigned int plt_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 + 9,
+ (got_base
+ + tlsdesc_got_offset
+ - (plt_address + plt_offset
+ + 13)));
+}
+
+// Return the APLT address to use for a global symbol (for IBT).
+
+template<int size>
+uint64_t
+Output_data_plt_x86_64_ibt<size>::do_address_for_global(const Symbol* gsym)
+{
+ uint64_t offset = this->aplt_offset_;
+ // Convert the PLT offset into an APLT offset.
+ unsigned int plt_offset = gsym->plt_offset();
+ if (gsym->type() == elfcpp::STT_GNU_IFUNC
+ && gsym->can_use_relative_reloc(false))
+ offset += this->regular_count() * aplt_entry_size;
+ else
+ plt_offset -= plt_entry_size;
+ plt_offset = plt_offset / (plt_entry_size / aplt_entry_size);
+ return this->address() + offset + plt_offset;
+}
+
+// Return the PLT address to use for a local symbol. These are always
+// IRELATIVE relocs.
+
+template<int size>
+uint64_t
+Output_data_plt_x86_64_ibt<size>::do_address_for_local(const Relobj* object,
+ unsigned int r_sym)
+{
+ // Convert the PLT offset into an APLT offset.
+ const Sized_relobj_file<size, false>* sized_relobj =
+ static_cast<const Sized_relobj_file<size, false>*>(object);
+ const Symbol_value<size>* psymval = sized_relobj->local_symbol(r_sym);
+ unsigned int plt_offset = ((object->local_plt_offset(r_sym)
+ - (psymval->is_ifunc_symbol()
+ ? 0 : plt_entry_size))
+ / (plt_entry_size / aplt_entry_size));
+ return (this->address()
+ + this->aplt_offset_
+ + this->regular_count() * aplt_entry_size
+ + plt_offset);
+}
+
+// Set the final size.
+
+template<int size>
+void
+Output_data_plt_x86_64_ibt<size>::set_final_data_size()
+{
+ // Number of regular and IFUNC PLT entries.
+ unsigned int count = this->entry_count();
+ // Count the first entry and the TLSDESC entry, if present.
+ unsigned int extra = this->has_tlsdesc_entry() ? 2 : 1;
+ unsigned int plt_size = (count + extra) * plt_entry_size;
+ // Offset of the APLT.
+ this->aplt_offset_ = plt_size;
+ // Size of the APLT.
+ plt_size += count * aplt_entry_size;
+ this->set_data_size(plt_size);
+}
+
+// The first entry in the IBT PLT.
+
+template<>
+const unsigned char
+Output_data_plt_x86_64_ibt<32>::first_plt_entry[plt_entry_size] =
+{
+ // MPX isn't supported for x32, so we don't need the BND prefix.
+ // From AMD64 ABI Draft 0.98, page 76
+ 0xff, 0x35, // pushq contents of memory address
+ 0, 0, 0, 0, // replaced with address of .got + 8
+ 0xff, 0x25, // jmp indirect
+ 0, 0, 0, 0, // replaced with address of .got + 16
+ 0x90, 0x90, 0x90, 0x90 // noop (x4)
+};
+
+template<>
+const unsigned char
+Output_data_plt_x86_64_ibt<64>::first_plt_entry[plt_entry_size] =
+{
+ // Use the BND prefix so that IBT is compatible with MPX.
+ 0xff, 0x35, // pushq contents of memory address
+ 0, 0, 0, 0, // replaced with address of .got + 8
+ 0xf2, 0xff, 0x25, // bnd jmp indirect
+ 0, 0, 0, 0, // replaced with address of .got + 16
+ 0x0f, 0x1f, 0x00 // nop
+};
+
+template<int size>
+void
+Output_data_plt_x86_64_ibt<size>::do_fill_first_plt_entry(
+ unsigned char* pov,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_address,
+ typename elfcpp::Elf_types<size>::Elf_Addr plt_address)
+{
+ // Offsets to the addresses needing relocation.
+ const unsigned int roff1 = 2;
+ const unsigned int roff2 = (size == 32) ? 8 : 9;
+
+ 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 + roff1,
+ (got_address + 8
+ - (plt_address + roff1 + 4)));
+ elfcpp::Swap<32, false>::writeval(pov + roff2,
+ (got_address + 16
+ - (plt_address + roff2 + 4)));
+}
+
+// Subsequent entries in the IBT PLT.
+
+template<>
+const unsigned char
+Output_data_plt_x86_64_ibt<32>::plt_entry[plt_entry_size] =
+{
+ // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
+ 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
+ 0x68, // pushq immediate
+ 0, 0, 0, 0, // replaced with offset into relocation table
+ 0xe9, // jmpq relative
+ 0, 0, 0, 0, // replaced with offset to start of .plt
+ 0x90, 0x90 // nop
+};
+
+template<>
+const unsigned char
+Output_data_plt_x86_64_ibt<64>::plt_entry[plt_entry_size] =
+{
+ // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
+ 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
+ 0x68, // pushq immediate
+ 0, 0, 0, 0, // replaced with offset into relocation table
+ 0xf2, 0xe9, // bnd jmpq relative
+ 0, 0, 0, 0, // replaced with offset to start of .plt
+ 0x90 // nop
+};
+
+// Entries in the IBT Additional PLT.
+
+template<>
+const unsigned char
+Output_data_plt_x86_64_ibt<32>::aplt_entry[aplt_entry_size] =
+{
+ // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
+ 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
+ 0xff, 0x25, // jmpq indirect
+ 0, 0, 0, 0, // replaced with address of symbol in .got
+ 0x0f, 0x1f, 0x04, 0x00, // nop
+ 0x90, 0x90 // nop
+};
+
+template<>
+const unsigned char
+Output_data_plt_x86_64_ibt<64>::aplt_entry[aplt_entry_size] =
+{
+ // From AMD64 ABI Draft 1.0-rc1, Chapter 13.
+ 0xf3, 0x0f, 0x1e, 0xfa, // endbr64
+ 0xf2, 0xff, 0x25, // bnd jmpq indirect
+ 0, 0, 0, 0, // replaced with address of symbol in .got
+ 0x0f, 0x1f, 0x04, 0x00, // nop
+ 0x90, // nop
+};
+
+template<int size>
+unsigned int
+Output_data_plt_x86_64_ibt<size>::do_fill_plt_entry(
+ unsigned char* pov,
+ typename elfcpp::Elf_types<size>::Elf_Addr,
+ typename elfcpp::Elf_types<size>::Elf_Addr,
+ unsigned int,
+ unsigned int plt_offset,
+ unsigned int plt_index)
+{
+ // Offsets to the addresses needing relocation.
+ const unsigned int roff1 = 5;
+ const unsigned int roff2 = (size == 32) ? 10 : 11;
+
+ memcpy(pov, plt_entry, plt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + roff1, plt_index);
+ elfcpp::Swap<32, false>::writeval(pov + roff2, -(plt_offset + roff2 + 4));
+ return 0;
+}
+
+template<int size>
+void
+Output_data_plt_x86_64_ibt<size>::fill_aplt_entry(
+ unsigned char* pov,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_address,
+ typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
+ unsigned int got_offset,
+ unsigned int plt_offset,
+ unsigned int plt_index)
+{
+ // Offset to the address needing relocation.
+ const unsigned int roff = (size == 32) ? 6 : 7;
+
+ // Check PC-relative offset overflow in PLT entry.
+ uint64_t plt_got_pcrel_offset = (got_address + got_offset
+ - (plt_address + plt_offset + roff + 4));
+ if (Bits<32>::has_overflow(plt_got_pcrel_offset))
+ gold_error(_("PC-relative offset overflow in APLT entry %d"),
+ plt_index + 1);
+
+ memcpy(pov, aplt_entry, aplt_entry_size);
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + roff, plt_got_pcrel_offset);
+}
+
+// The reserved TLSDESC entry in the IBT PLT for an executable.
+
+template<int size>
+const unsigned char
+Output_data_plt_x86_64_ibt<size>::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)
+ 0xf2, 0xff, 0x25, // jmpq *y(%rip)
+ 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
+ 0x0f, 0x1f, 0 // nop
+};
+
+template<int size>
+void
+Output_data_plt_x86_64_ibt<size>::do_fill_tlsdesc_entry(
+ unsigned char* pov,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_address,
+ typename elfcpp::Elf_types<size>::Elf_Addr plt_address,
+ typename elfcpp::Elf_types<size>::Elf_Addr got_base,
+ unsigned int tlsdesc_got_offset,
+ unsigned int plt_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 + 9,
+ (got_base
+ + tlsdesc_got_offset
+ - (plt_address + plt_offset
+ + 13)));
+}
+
// The .eh_frame unwind information for the PLT.
template<int size>
elfcpp::DW_CFA_nop
};
+// The .eh_frame unwind information for the BND PLT.
+const unsigned char
+Output_data_plt_x86_64_bnd::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_lit5, // Push 5.
+ elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 5)
+ elfcpp::DW_OP_lit3, // Push 3.
+ elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 5) << 3)
+ elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=5)<<3)+%rsp+8
+ elfcpp::DW_CFA_nop, // Align to 32 bytes.
+ elfcpp::DW_CFA_nop,
+ elfcpp::DW_CFA_nop,
+ elfcpp::DW_CFA_nop
+};
+
+// The .eh_frame unwind information for the BND PLT.
+template<int size>
+const unsigned char
+Output_data_plt_x86_64_ibt<size>::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_lit9, // Push 9.
+ elfcpp::DW_OP_ge, // >= ((%rip & 0xf) >= 9)
+ elfcpp::DW_OP_lit3, // Push 3.
+ elfcpp::DW_OP_shl, // << (((%rip & 0xf) >= 9) << 3)
+ elfcpp::DW_OP_plus, // + ((((%rip&0xf)>=9)<<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.
this->fill_first_plt_entry(pov, got_address, plt_address);
pov += this->get_plt_entry_size();
- unsigned char* got_pov = got_view;
-
- // 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;
+ // The first three entries in the GOT are reserved, and are written
+ // by Output_data_got_plt_x86_64::do_write.
+ unsigned char* got_pov = got_view + 24;
unsigned int plt_offset = this->get_plt_entry_size();
unsigned int got_offset = 24;
++plt_index,
pov += this->get_plt_entry_size(),
got_pov += 8,
- plt_offset += this->get_plt_entry_size(),
+ plt_offset += this->get_plt_entry_size(),
+ got_offset += 8)
+ {
+ // Set and adjust the PLT entry itself.
+ unsigned int lazy_offset = this->fill_plt_entry(pov,
+ got_address, plt_address,
+ got_offset, plt_offset,
+ plt_index);
+
+ // Set the entry in the GOT.
+ elfcpp::Swap<64, false>::writeval(got_pov,
+ plt_address + plt_offset + lazy_offset);
+ }
+
+ if (this->has_tlsdesc_entry())
+ {
+ // Set and adjust the reserved TLSDESC PLT entry.
+ unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
+ this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
+ tlsdesc_got_offset, plt_offset);
+ pov += this->get_plt_entry_size();
+ }
+
+ gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
+ gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
+
+ of->write_output_view(offset, oview_size, oview);
+ of->write_output_view(got_file_offset, got_size, got_view);
+}
+
+// Write out the BND PLT.
+
+void
+Output_data_plt_x86_64_bnd::do_write(Output_file* of)
+{
+ const off_t offset = this->offset();
+ const section_size_type oview_size =
+ convert_to_section_size_type(this->data_size());
+ unsigned char* const oview = of->get_output_view(offset, oview_size);
+
+ Output_data_got<64, false>* got = this->got();
+ Output_data_got_plt_x86_64* got_plt = this->got_plt();
+ Output_data_space* got_irelative = this->got_irelative();
+
+ const off_t got_file_offset = got_plt->offset();
+ gold_assert(parameters->incremental_update()
+ || (got_file_offset + got_plt->data_size()
+ == got_irelative->offset()));
+ const section_size_type got_size =
+ convert_to_section_size_type(got_plt->data_size()
+ + got_irelative->data_size());
+ unsigned char* const got_view = of->get_output_view(got_file_offset,
+ got_size);
+
+ unsigned char* pov = oview;
+
+ // The base address of the .plt section.
+ elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
+ // The base address of the .got section.
+ elfcpp::Elf_types<64>::Elf_Addr got_base = 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 = got_plt->address();
+
+ this->fill_first_plt_entry(pov, got_address, plt_address);
+ pov += plt_entry_size;
+
+ // The first three entries in the GOT are reserved, and are written
+ // by Output_data_got_plt_x86_64::do_write.
+ unsigned char* got_pov = got_view + 24;
+
+ unsigned int plt_offset = plt_entry_size;
+ unsigned int got_offset = 24;
+ const unsigned int count = this->entry_count();
+ for (unsigned int plt_index = 0;
+ plt_index < count;
+ ++plt_index,
+ pov += plt_entry_size,
+ got_pov += 8,
+ plt_offset += plt_entry_size,
+ got_offset += 8)
+ {
+ // Set and adjust the PLT entry itself.
+ unsigned int lazy_offset = this->fill_plt_entry(pov,
+ got_address, plt_address,
+ got_offset, plt_offset,
+ plt_index);
+
+ // Set the entry in the GOT.
+ elfcpp::Swap<64, false>::writeval(got_pov,
+ plt_address + plt_offset + lazy_offset);
+ }
+
+ if (this->has_tlsdesc_entry())
+ {
+ // Set and adjust the reserved TLSDESC PLT entry.
+ unsigned int tlsdesc_got_offset = this->get_tlsdesc_got_offset();
+ this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
+ tlsdesc_got_offset, plt_offset);
+ pov += this->get_plt_entry_size();
+ plt_offset += plt_entry_size;
+ }
+
+ // Write the additional PLT.
+ got_offset = 24;
+ for (unsigned int plt_index = 0;
+ plt_index < count;
+ ++plt_index,
+ pov += aplt_entry_size,
+ plt_offset += aplt_entry_size,
+ got_offset += 8)
+ {
+ // Set and adjust the APLT entry.
+ this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
+ plt_offset, plt_index);
+ }
+
+ gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
+ gold_assert(static_cast<section_size_type>(got_pov - got_view) == got_size);
+
+ of->write_output_view(offset, oview_size, oview);
+ of->write_output_view(got_file_offset, got_size, got_view);
+}
+
+// Write out the IBT PLT.
+
+template<int size>
+void
+Output_data_plt_x86_64_ibt<size>::do_write(Output_file* of)
+{
+ const off_t offset = this->offset();
+ const section_size_type oview_size =
+ convert_to_section_size_type(this->data_size());
+ unsigned char* const oview = of->get_output_view(offset, oview_size);
+
+ Output_data_got<64, false>* got = this->got();
+ Output_data_got_plt_x86_64* got_plt = this->got_plt();
+ Output_data_space* got_irelative = this->got_irelative();
+
+ const off_t got_file_offset = got_plt->offset();
+ gold_assert(parameters->incremental_update()
+ || (got_file_offset + got_plt->data_size()
+ == got_irelative->offset()));
+ const section_size_type got_size =
+ convert_to_section_size_type(got_plt->data_size()
+ + got_irelative->data_size());
+ unsigned char* const got_view = of->get_output_view(got_file_offset,
+ got_size);
+
+ unsigned char* pov = oview;
+
+ // The base address of the .plt section.
+ elfcpp::Elf_types<64>::Elf_Addr plt_address = this->address();
+ // The base address of the .got section.
+ elfcpp::Elf_types<64>::Elf_Addr got_base = 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 = got_plt->address();
+
+ this->fill_first_plt_entry(pov, got_address, plt_address);
+ pov += plt_entry_size;
+
+ // The first three entries in the GOT are reserved, and are written
+ // by Output_data_got_plt_x86_64::do_write.
+ unsigned char* got_pov = got_view + 24;
+
+ unsigned int plt_offset = plt_entry_size;
+ unsigned int got_offset = 24;
+ const unsigned int count = this->entry_count();
+ for (unsigned int plt_index = 0;
+ plt_index < count;
+ ++plt_index,
+ pov += plt_entry_size,
+ got_pov += 8,
+ plt_offset += plt_entry_size,
got_offset += 8)
{
// Set and adjust the PLT entry itself.
this->fill_tlsdesc_entry(pov, got_address, plt_address, got_base,
tlsdesc_got_offset, plt_offset);
pov += this->get_plt_entry_size();
+ plt_offset += plt_entry_size;
+ }
+
+ // Write the additional PLT.
+ got_offset = 24;
+ for (unsigned int plt_index = 0;
+ plt_index < count;
+ ++plt_index,
+ pov += aplt_entry_size,
+ plt_offset += aplt_entry_size,
+ got_offset += 8)
+ {
+ // Set and adjust the APLT entry.
+ this->fill_aplt_entry(pov, got_address, plt_address, got_offset,
+ plt_offset, plt_index);
}
gold_assert(static_cast<section_size_type>(pov - oview) == oview_size);
}
}
+template<>
+Output_data_plt_x86_64<32>*
+Target_x86_64<32>::do_make_data_plt(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative)
+{
+ if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
+ return new Output_data_plt_x86_64_ibt<32>(layout, got, got_plt,
+ got_irelative);
+ return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
+ got_irelative);
+}
+
+template<>
+Output_data_plt_x86_64<64>*
+Target_x86_64<64>::do_make_data_plt(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative)
+{
+ if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
+ return new Output_data_plt_x86_64_ibt<64>(layout, got, got_plt,
+ got_irelative);
+ else if (parameters->options().bndplt())
+ return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
+ got_irelative);
+ else
+ return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
+ got_irelative);
+}
+
+template<>
+Output_data_plt_x86_64<32>*
+Target_x86_64<32>::do_make_data_plt(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative,
+ unsigned int plt_count)
+{
+ if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
+ return new Output_data_plt_x86_64_ibt<32>(layout, got, got_plt,
+ got_irelative, plt_count);
+ return new Output_data_plt_x86_64_standard<32>(layout, got, got_plt,
+ got_irelative, plt_count);
+}
+
+template<>
+Output_data_plt_x86_64<64>*
+Target_x86_64<64>::do_make_data_plt(Layout* layout,
+ Output_data_got<64, false>* got,
+ Output_data_got_plt_x86_64* got_plt,
+ Output_data_space* got_irelative,
+ unsigned int plt_count)
+{
+ if (this->feature_1_ & elfcpp::GNU_PROPERTY_X86_FEATURE_1_IBT)
+ return new Output_data_plt_x86_64_ibt<64>(layout, got, got_plt,
+ got_irelative, plt_count);
+ else if (parameters->options().bndplt())
+ return new Output_data_plt_x86_64_bnd(layout, got, got_plt,
+ got_irelative, plt_count);
+ else
+ return new Output_data_plt_x86_64_standard<64>(layout, got, got_plt,
+ got_irelative,
+ plt_count);
+}
+
// Return the section for TLSDESC relocations.
template<int size>
unsigned int
Target_x86_64<size>::first_plt_entry_offset() const
{
+ if (this->plt_ == NULL)
+ return 0;
return this->plt_->first_plt_entry_offset();
}
unsigned int
Target_x86_64<size>::plt_entry_size() const
{
+ if (this->plt_ == NULL)
+ return 0;
return this->plt_->get_plt_entry_size();
}
true);
// Add the three reserved entries.
- this->got_plt_ = new Output_data_space((plt_count + 3) * 8, 8, "** GOT PLT");
+ this->got_plt_ = new Output_data_got_plt_x86_64(layout, (plt_count + 3) * 8);
layout->add_output_section_data(".got.plt", elfcpp::SHT_PROGBITS,
(elfcpp::SHF_ALLOC
| elfcpp::SHF_WRITE),
case elfcpp::R_X86_64_PC64:
case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PC32_BND:
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_PLT32_BND:
case elfcpp::R_X86_64_PLTOFF64:
return Symbol::FUNCTION_CALL | Symbol::RELATIVE_REF;
case elfcpp::R_X86_64_GOT32:
case elfcpp::R_X86_64_GOTPCREL64:
case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPCRELX:
+ case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_GOTPLT64:
// Absolute in GOT.
return Symbol::ABSOLUTE_REF;
// glibc supports these reloc types, but they can overflow.
case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PC32_BND:
// A PC relative reference is OK against a local symbol or if
// the symbol is defined locally.
if (gsym == NULL
&& !gsym->is_undefined()
&& !gsym->is_preemptible()))
return;
- /* Fall through. */
+ // Fall through.
case elfcpp::R_X86_64_32:
// R_X86_64_32 is OK for x32.
if (size == 32 && r_type == elfcpp::R_X86_64_32)
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());
+ {
+ const char *r_name;
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_32:
+ r_name = "R_X86_64_32";
+ break;
+ case elfcpp::R_X86_64_PC32:
+ r_name = "R_X86_64_PC32";
+ break;
+ case elfcpp::R_X86_64_PC32_BND:
+ r_name = "R_X86_64_PC32_BND";
+ break;
+ default:
+ gold_unreachable();
+ break;
+ }
+ object->error(_("requires dynamic %s reloc against '%s' "
+ "which may overflow at runtime; recompile "
+ "with -fPIC"),
+ r_name, gsym->name());
+ }
this->issued_non_pic_error_ = true;
return;
case elfcpp::R_X86_64_PC64:
case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PC32_BND:
case elfcpp::R_X86_64_PC16:
case elfcpp::R_X86_64_PC8:
break;
case elfcpp::R_X86_64_PLT32:
+ case elfcpp::R_X86_64_PLT32_BND:
// Since we know this is a local symbol, we can handle this as a
// PC32 reloc.
break;
case elfcpp::R_X86_64_GOT32:
case elfcpp::R_X86_64_GOTPCREL64:
case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPCRELX:
+ case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_GOTPLT64:
{
- // The symbol requires a GOT entry.
+ // The symbol requires a GOT section.
Output_data_got<64, false>* got = target->got_section(symtab, layout);
+
+ // If the relocation symbol isn't IFUNC,
+ // and is local, then we will convert
+ // mov foo@GOTPCREL(%rip), %reg
+ // to lea foo(%rip), %reg.
+ // in Relocate::relocate.
+ if (!parameters->incremental()
+ && (r_type == elfcpp::R_X86_64_GOTPCREL
+ || r_type == elfcpp::R_X86_64_GOTPCRELX
+ || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
+ && reloc.get_r_offset() >= 2
+ && !is_ifunc)
+ {
+ section_size_type stype;
+ const unsigned char* view = object->section_contents(data_shndx,
+ &stype, true);
+ if (view[reloc.get_r_offset() - 2] == 0x8b)
+ break;
+ }
+
+ // The symbol requires a GOT entry.
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
// For a STT_GNU_IFUNC symbol we want the PLT offset. That
// Returns true if this relocation type could be that of a function pointer.
template<int size>
inline bool
-Target_x86_64<size>::Scan::possible_function_pointer_reloc(unsigned int r_type)
+Target_x86_64<size>::Scan::possible_function_pointer_reloc(
+ Sized_relobj_file<size, false>* src_obj,
+ unsigned int src_indx,
+ unsigned int r_offset,
+ unsigned int r_type)
{
switch (r_type)
{
case elfcpp::R_X86_64_GOT32:
case elfcpp::R_X86_64_GOTPCREL64:
case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPCRELX:
+ case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_GOTPLT64:
{
return true;
}
+ case elfcpp::R_X86_64_PC32:
+ {
+ // This relocation may be used both for function calls and
+ // for taking address of a function. We distinguish between
+ // them by checking the opcodes.
+ uint64_t sh_flags = src_obj->section_flags(src_indx);
+ bool is_executable = (sh_flags & elfcpp::SHF_EXECINSTR) != 0;
+ if (is_executable)
+ {
+ section_size_type stype;
+ const unsigned char* view = src_obj->section_contents(src_indx,
+ &stype,
+ true);
+
+ // call
+ if (r_offset >= 1
+ && view[r_offset - 1] == 0xe8)
+ return false;
+
+ // jmp
+ if (r_offset >= 1
+ && view[r_offset - 1] == 0xe9)
+ return false;
+
+ // jo/jno/jb/jnb/je/jne/jna/ja/js/jns/jp/jnp/jl/jge/jle/jg
+ if (r_offset >= 2
+ && view[r_offset - 2] == 0x0f
+ && view[r_offset - 1] >= 0x80
+ && view[r_offset - 1] <= 0x8f)
+ return false;
+ }
+
+ // Be conservative and treat all others as function pointers.
+ return true;
+ }
}
return false;
}
Symbol_table* ,
Layout* ,
Target_x86_64<size>* ,
- Sized_relobj_file<size, false>* ,
- unsigned int ,
+ Sized_relobj_file<size, false>* src_obj,
+ unsigned int src_indx,
Output_section* ,
- const elfcpp::Rela<size, false>& ,
+ const elfcpp::Rela<size, false>& reloc,
unsigned int r_type,
const elfcpp::Sym<size, false>&)
{
// When building a shared library, do not fold any local symbols as it is
// not possible to distinguish pointer taken versus a call by looking at
// the relocation types.
- return (parameters->options().shared()
- || possible_function_pointer_reloc(r_type));
+ if (parameters->options().shared())
+ return true;
+
+ return possible_function_pointer_reloc(src_obj, src_indx,
+ reloc.get_r_offset(), r_type);
}
// For safe ICF, scan a relocation for a global symbol to check if it
Symbol_table*,
Layout* ,
Target_x86_64<size>* ,
- Sized_relobj_file<size, false>* ,
- unsigned int ,
+ Sized_relobj_file<size, false>* src_obj,
+ unsigned int src_indx,
Output_section* ,
- const elfcpp::Rela<size, false>& ,
+ const elfcpp::Rela<size, false>& reloc,
unsigned int r_type,
Symbol* gsym)
{
// When building a shared library, do not fold symbols whose visibility
// is hidden, internal or protected.
- return ((parameters->options().shared()
- && (gsym->visibility() == elfcpp::STV_INTERNAL
- || gsym->visibility() == elfcpp::STV_PROTECTED
- || gsym->visibility() == elfcpp::STV_HIDDEN))
- || possible_function_pointer_reloc(r_type));
+ if (parameters->options().shared()
+ && (gsym->visibility() == elfcpp::STV_INTERNAL
+ || gsym->visibility() == elfcpp::STV_PROTECTED
+ || gsym->visibility() == elfcpp::STV_HIDDEN))
+ return true;
+
+ return possible_function_pointer_reloc(src_obj, src_indx,
+ reloc.get_r_offset(), r_type);
}
// Scan a relocation for a global symbol.
// Make a dynamic relocation if necessary.
if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
{
- if (gsym->may_need_copy_reloc())
+ if (!parameters->options().output_is_position_independent()
+ && gsym->may_need_copy_reloc())
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
case elfcpp::R_X86_64_PC64:
case elfcpp::R_X86_64_PC32:
+ case elfcpp::R_X86_64_PC32_BND:
case elfcpp::R_X86_64_PC16:
case elfcpp::R_X86_64_PC8:
{
// Make a dynamic relocation if necessary.
if (gsym->needs_dynamic_reloc(Scan::get_reference_flags(r_type)))
{
- if (gsym->may_need_copy_reloc())
+ if (parameters->options().output_is_executable()
+ && gsym->may_need_copy_reloc())
{
target->copy_reloc(symtab, layout, object,
data_shndx, output_section, gsym, reloc);
case elfcpp::R_X86_64_GOT32:
case elfcpp::R_X86_64_GOTPCREL64:
case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPCRELX:
+ case elfcpp::R_X86_64_REX_GOTPCRELX:
case elfcpp::R_X86_64_GOTPLT64:
{
// The symbol requires a GOT entry.
Output_data_got<64, false>* got = target->got_section(symtab, layout);
+
+ // If we convert this from
+ // mov foo@GOTPCREL(%rip), %reg
+ // to lea foo(%rip), %reg.
+ // OR
+ // if we convert
+ // (callq|jmpq) *foo@GOTPCRELX(%rip) to
+ // (callq|jmpq) foo
+ // in Relocate::relocate, then there is nothing to do here.
+ // We cannot make these optimizations in incremental linking mode,
+ // because we look at the opcode to decide whether or not to make
+ // change, and during an incremental update, the change may have
+ // already been applied.
+
+ Lazy_view<size> view(object, data_shndx);
+ size_t r_offset = reloc.get_r_offset();
+ if (!parameters->incremental()
+ && r_offset >= 2
+ && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
+ r_offset, &view))
+ break;
+
+ if (!parameters->incremental()
+ && r_offset >= 2
+ && Target_x86_64<size>::can_convert_callq_to_direct(gsym, r_type,
+ r_offset,
+ &view))
+ break;
+
if (gsym->final_value_is_known())
{
// For a STT_GNU_IFUNC symbol we want the PLT address.
}
}
}
- // For GOTPLT64, we also need a PLT entry (but only if the
- // symbol is not fully resolved).
- if (r_type == elfcpp::R_X86_64_GOTPLT64
- && !gsym->final_value_is_known())
- target->make_plt_entry(symtab, layout, gsym);
}
break;
case elfcpp::R_X86_64_PLT32:
+ case elfcpp::R_X86_64_PLT32_BND:
// If the symbol is fully resolved, this is just a PC32 reloc.
// Otherwise we need a PLT entry.
if (gsym->final_value_is_known())
case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
case elfcpp::R_X86_64_TPOFF32: // Local-exec
{
- const bool is_final = gsym->final_value_is_known();
+ // For the Initial-Exec model, we can treat undef symbols as final
+ // when building an executable.
+ const bool is_final = (gsym->final_value_is_known() ||
+ (r_type == elfcpp::R_X86_64_GOTTPOFF &&
+ gsym->is_undefined() &&
+ parameters->options().output_is_executable()));
const tls::Tls_optimization optimized_type
= Target_x86_64<size>::optimize_tls_reloc(is_final, r_type);
switch (r_type)
size_t local_symbol_count,
const unsigned char* plocal_symbols)
{
+ typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
+ Classify_reloc;
if (sh_type == elfcpp::SHT_REL)
{
return;
}
- gold::gc_process_relocs<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
- typename Target_x86_64<size>::Scan,
- typename Target_x86_64<size>::Relocatable_size_for_reloc>(
+ gold::gc_process_relocs<size, false, Target_x86_64<size>, Scan,
+ Classify_reloc>(
symtab,
layout,
this,
size_t local_symbol_count,
const unsigned char* plocal_symbols)
{
+ typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
+ Classify_reloc;
+
if (sh_type == elfcpp::SHT_REL)
{
gold_error(_("%s: unsupported REL reloc section"),
return;
}
- gold::scan_relocs<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
- typename Target_x86_64<size>::Scan>(
+ gold::scan_relocs<size, false, Target_x86_64<size>, Scan, Classify_reloc>(
symtab,
layout,
this,
}
}
+// For x32, we need to handle PC-relative relocations using full 64-bit
+// arithmetic, so that we can detect relocation overflows properly.
+// This class overrides the pcrela32_check methods from the defaults in
+// Relocate_functions in reloc.h.
+
+template<int size>
+class X86_64_relocate_functions : public Relocate_functions<size, false>
+{
+ public:
+ typedef Relocate_functions<size, false> Base;
+
+ // Do a simple PC relative relocation with the addend in the
+ // relocation.
+ static inline typename Base::Reloc_status
+ pcrela32_check(unsigned char* view,
+ typename elfcpp::Elf_types<64>::Elf_Addr value,
+ typename elfcpp::Elf_types<64>::Elf_Swxword addend,
+ typename elfcpp::Elf_types<64>::Elf_Addr address)
+ {
+ typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ value = value + addend - address;
+ elfcpp::Swap<32, false>::writeval(wv, value);
+ return (Bits<32>::has_overflow(value)
+ ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
+ }
+
+ // Do a simple PC relative relocation with a Symbol_value with the
+ // addend in the relocation.
+ static inline typename Base::Reloc_status
+ pcrela32_check(unsigned char* view,
+ const Sized_relobj_file<size, false>* object,
+ const Symbol_value<size>* psymval,
+ typename elfcpp::Elf_types<64>::Elf_Swxword addend,
+ typename elfcpp::Elf_types<64>::Elf_Addr address)
+ {
+ typedef typename elfcpp::Swap<32, false>::Valtype Valtype;
+ Valtype* wv = reinterpret_cast<Valtype*>(view);
+ typename elfcpp::Elf_types<64>::Elf_Addr value;
+ if (addend >= 0)
+ value = psymval->value(object, addend);
+ else
+ {
+ // For negative addends, get the symbol value without
+ // the addend, then add the addend using 64-bit arithmetic.
+ value = psymval->value(object, 0);
+ value += addend;
+ }
+ value -= address;
+ elfcpp::Swap<32, false>::writeval(wv, value);
+ return (Bits<32>::has_overflow(value)
+ ? Base::RELOC_OVERFLOW : Base::RELOC_OK);
+ }
+};
+
// Perform a relocation.
template<int size>
inline bool
Target_x86_64<size>::Relocate::relocate(
const Relocate_info<size, false>* relinfo,
+ unsigned int,
Target_x86_64<size>* target,
Output_section*,
size_t relnum,
- const elfcpp::Rela<size, false>& rela,
- unsigned int r_type,
+ const unsigned char* preloc,
const Sized_symbol<size>* gsym,
const Symbol_value<size>* psymval,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr address,
section_size_type view_size)
{
+ typedef X86_64_relocate_functions<size> Reloc_funcs;
+ const elfcpp::Rela<size, false> rela(preloc);
+ unsigned int r_type = elfcpp::elf_r_type<size>(rela.get_r_info());
+
if (this->skip_call_tls_get_addr_)
{
if ((r_type != elfcpp::R_X86_64_PLT32
+ && r_type != elfcpp::R_X86_64_GOTPCREL
+ && r_type != elfcpp::R_X86_64_GOTPCRELX
+ && r_type != elfcpp::R_X86_64_PLT32_BND
+ && r_type != elfcpp::R_X86_64_PC32_BND
&& r_type != elfcpp::R_X86_64_PC32)
|| gsym == NULL
|| strcmp(gsym->name(), "__tls_get_addr") != 0)
{
gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
_("missing expected TLS relocation"));
+ this->skip_call_tls_get_addr_ = false;
}
else
{
// We need to subtract the size of the GOT section to get
// the actual offset to use in the relocation.
bool have_got_offset = false;
- unsigned int got_offset = 0;
+ // Since the actual offset is always negative, we use signed int to
+ // support 64-bit GOT relocations.
+ int got_offset = 0;
switch (r_type)
{
case elfcpp::R_X86_64_GOT32:
case elfcpp::R_X86_64_GOT64:
case elfcpp::R_X86_64_GOTPLT64:
- case elfcpp::R_X86_64_GOTPCREL:
case elfcpp::R_X86_64_GOTPCREL64:
if (gsym != NULL)
{
break;
}
+ typename Reloc_funcs::Reloc_status rstatus = Reloc_funcs::RELOC_OK;
+
switch (r_type)
{
case elfcpp::R_X86_64_NONE:
break;
case elfcpp::R_X86_64_64:
- Relocate_functions<size, false>::rela64(view, object, psymval, addend);
+ Reloc_funcs::rela64(view, object, psymval, addend);
break;
case elfcpp::R_X86_64_PC64:
- Relocate_functions<size, false>::pcrela64(view, object, psymval, addend,
+ Reloc_funcs::pcrela64(view, object, psymval, addend,
address);
break;
case elfcpp::R_X86_64_32:
- // FIXME: we need to verify that value + addend fits into 32 bits:
- // uint64_t x = value + addend;
- // x == static_cast<uint64_t>(static_cast<uint32_t>(x))
- // Likewise for other <=32-bit relocations (but see R_X86_64_32S).
- Relocate_functions<size, false>::rela32(view, object, psymval, addend);
+ rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
+ Reloc_funcs::CHECK_UNSIGNED);
break;
case elfcpp::R_X86_64_32S:
- // FIXME: we need to verify that value + addend fits into 32 bits:
- // int64_t x = value + addend; // note this quantity is signed!
- // x == static_cast<int64_t>(static_cast<int32_t>(x))
- Relocate_functions<size, false>::rela32(view, object, psymval, addend);
+ rstatus = Reloc_funcs::rela32_check(view, object, psymval, addend,
+ Reloc_funcs::CHECK_SIGNED);
break;
case elfcpp::R_X86_64_PC32:
- Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
- address);
+ case elfcpp::R_X86_64_PC32_BND:
+ rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
+ address);
break;
case elfcpp::R_X86_64_16:
- Relocate_functions<size, false>::rela16(view, object, psymval, addend);
+ Reloc_funcs::rela16(view, object, psymval, addend);
break;
case elfcpp::R_X86_64_PC16:
- Relocate_functions<size, false>::pcrela16(view, object, psymval, addend,
- address);
+ Reloc_funcs::pcrela16(view, object, psymval, addend, address);
break;
case elfcpp::R_X86_64_8:
- Relocate_functions<size, false>::rela8(view, object, psymval, addend);
+ Reloc_funcs::rela8(view, object, psymval, addend);
break;
case elfcpp::R_X86_64_PC8:
- Relocate_functions<size, false>::pcrela8(view, object, psymval, addend,
- address);
+ Reloc_funcs::pcrela8(view, object, psymval, addend, address);
break;
case elfcpp::R_X86_64_PLT32:
+ case elfcpp::R_X86_64_PLT32_BND:
gold_assert(gsym == NULL
|| gsym->has_plt_offset()
|| gsym->final_value_is_known()
// Note: while this code looks the same as for R_X86_64_PC32, it
// behaves differently because psymval was set to point to
// the PLT entry, rather than the symbol, in Scan::global().
- Relocate_functions<size, false>::pcrela32(view, object, psymval, addend,
- address);
+ rstatus = Reloc_funcs::pcrela32_check(view, object, psymval, addend,
+ address);
break;
case elfcpp::R_X86_64_PLTOFF64:
gold_assert(gsym->has_plt_offset()
|| gsym->final_value_is_known());
typename elfcpp::Elf_types<size>::Elf_Addr got_address;
- got_address = target->got_section(NULL, NULL)->address();
- Relocate_functions<size, false>::rela64(view, object, psymval,
- addend - got_address);
+ // This is the address of GLOBAL_OFFSET_TABLE.
+ got_address = target->got_plt_section()->address();
+ Reloc_funcs::rela64(view, object, psymval, addend - got_address);
}
+ break;
case elfcpp::R_X86_64_GOT32:
gold_assert(have_got_offset);
- Relocate_functions<size, false>::rela32(view, got_offset, addend);
+ Reloc_funcs::rela32(view, got_offset, addend);
break;
case elfcpp::R_X86_64_GOTPC32:
gold_assert(gsym);
typename elfcpp::Elf_types<size>::Elf_Addr value;
value = target->got_plt_section()->address();
- Relocate_functions<size, false>::pcrela32(view, value, addend, address);
+ Reloc_funcs::pcrela32_check(view, value, addend, address);
}
break;
case elfcpp::R_X86_64_GOT64:
- // The ABI doc says "Like GOT64, but indicates a PLT entry is needed."
- // Since we always add a PLT entry, this is equivalent.
case elfcpp::R_X86_64_GOTPLT64:
+ // R_X86_64_GOTPLT64 is obsolete and treated the same as
+ // GOT64.
gold_assert(have_got_offset);
- Relocate_functions<size, false>::rela64(view, got_offset, addend);
+ Reloc_funcs::rela64(view, got_offset, addend);
break;
case elfcpp::R_X86_64_GOTPC64:
gold_assert(gsym);
typename elfcpp::Elf_types<size>::Elf_Addr value;
value = target->got_plt_section()->address();
- Relocate_functions<size, false>::pcrela64(view, value, addend, address);
+ Reloc_funcs::pcrela64(view, value, addend, address);
}
break;
case elfcpp::R_X86_64_GOTOFF64:
{
- typename elfcpp::Elf_types<size>::Elf_Addr value;
- value = (psymval->value(object, 0)
- - target->got_plt_section()->address());
- Relocate_functions<size, false>::rela64(view, value, addend);
+ typename elfcpp::Elf_types<size>::Elf_Addr reladdr;
+ reladdr = target->got_plt_section()->address();
+ Reloc_funcs::pcrela64(view, object, psymval, addend, reladdr);
}
break;
case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPCRELX:
+ case elfcpp::R_X86_64_REX_GOTPCRELX:
{
- gold_assert(have_got_offset);
- typename elfcpp::Elf_types<size>::Elf_Addr value;
- value = target->got_plt_section()->address() + got_offset;
- Relocate_functions<size, false>::pcrela32(view, value, addend, address);
+ // Convert
+ // mov foo@GOTPCREL(%rip), %reg
+ // to lea foo(%rip), %reg.
+ // if possible.
+ if (!parameters->incremental()
+ && ((gsym == NULL
+ && rela.get_r_offset() >= 2
+ && view[-2] == 0x8b
+ && !psymval->is_ifunc_symbol())
+ || (gsym != NULL
+ && rela.get_r_offset() >= 2
+ && Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
+ 0, &view))))
+ {
+ view[-2] = 0x8d;
+ Reloc_funcs::pcrela32(view, object, psymval, addend, address);
+ }
+ // Convert
+ // callq *foo@GOTPCRELX(%rip) to
+ // addr32 callq foo
+ // and jmpq *foo@GOTPCRELX(%rip) to
+ // jmpq foo
+ // nop
+ else if (!parameters->incremental()
+ && gsym != NULL
+ && rela.get_r_offset() >= 2
+ && Target_x86_64<size>::can_convert_callq_to_direct(gsym,
+ r_type,
+ 0, &view))
+ {
+ if (view[-1] == 0x15)
+ {
+ // Convert callq *foo@GOTPCRELX(%rip) to addr32 callq.
+ // Opcode of addr32 is 0x67 and opcode of direct callq is 0xe8.
+ view[-2] = 0x67;
+ view[-1] = 0xe8;
+ // Convert GOTPCRELX to 32-bit pc relative reloc.
+ Reloc_funcs::pcrela32(view, object, psymval, addend, address);
+ }
+ else
+ {
+ // Convert jmpq *foo@GOTPCRELX(%rip) to
+ // jmpq foo
+ // nop
+ // The opcode of direct jmpq is 0xe9.
+ view[-2] = 0xe9;
+ // The opcode of nop is 0x90.
+ view[3] = 0x90;
+ // Convert GOTPCRELX to 32-bit pc relative reloc. jmpq is rip
+ // relative and since the instruction following the jmpq is now
+ // the nop, offset the address by 1 byte. The start of the
+ // relocation also moves ahead by 1 byte.
+ Reloc_funcs::pcrela32(&view[-1], object, psymval, addend,
+ address - 1);
+ }
+ }
+ else
+ {
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
+ got_offset = (gsym->got_offset(GOT_TYPE_STANDARD)
+ - target->got_size());
+ }
+ else
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
+ gold_assert(object->local_has_got_offset(r_sym,
+ GOT_TYPE_STANDARD));
+ got_offset = (object->local_got_offset(r_sym, GOT_TYPE_STANDARD)
+ - target->got_size());
+ }
+ typename elfcpp::Elf_types<size>::Elf_Addr value;
+ value = target->got_plt_section()->address() + got_offset;
+ Reloc_funcs::pcrela32_check(view, value, addend, address);
+ }
}
break;
gold_assert(have_got_offset);
typename elfcpp::Elf_types<size>::Elf_Addr value;
value = target->got_plt_section()->address() + got_offset;
- Relocate_functions<size, false>::pcrela64(view, value, addend, address);
+ Reloc_funcs::pcrela64(view, value, addend, address);
}
break;
break;
}
+ if (rstatus == Reloc_funcs::RELOC_OVERFLOW)
+ {
+ if (gsym == NULL)
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<size>(rela.get_r_info());
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("relocation overflow: "
+ "reference to local symbol %u in %s"),
+ r_sym, object->name().c_str());
+ }
+ else if (gsym->is_defined() && gsym->source() == Symbol::FROM_OBJECT)
+ {
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("relocation overflow: "
+ "reference to '%s' defined in %s"),
+ gsym->name(),
+ gsym->object()->name().c_str());
+ }
+ else
+ {
+ gold_error_at_location(relinfo, relnum, rela.get_r_offset(),
+ _("relocation overflow: reference to '%s'"),
+ gsym->name());
+ }
+ }
+
return true;
}
if (optimized_type == tls::TLSOPT_TO_IE)
{
value = target->got_plt_section()->address() + got_offset;
- this->tls_gd_to_ie(relinfo, relnum, tls_segment, rela, r_type,
+ this->tls_gd_to_ie(relinfo, relnum, rela, r_type,
value, view, address, view_size);
break;
}
}
if (optimized_type == tls::TLSOPT_TO_IE)
{
- 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,
+ this->tls_desc_gd_to_ie(relinfo, relnum,
rela, r_type, value, view, address,
view_size);
break;
break;
case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
- if (optimized_type == tls::TLSOPT_TO_LE)
+ if (gsym != NULL
+ && gsym->is_undefined()
+ && parameters->options().output_is_executable())
+ {
+ Target_x86_64<size>::Relocate::tls_ie_to_le(relinfo, relnum,
+ NULL, rela,
+ r_type, value, view,
+ view_size);
+ break;
+ }
+ else if (optimized_type == tls::TLSOPT_TO_LE)
{
if (tls_segment == NULL)
{
Target_x86_64<size>::Relocate::tls_gd_to_ie(
const Relocate_info<size, false>* relinfo,
size_t relnum,
- Output_segment*,
const elfcpp::Rela<size, false>& rela,
unsigned int,
typename elfcpp::Elf_types<size>::Elf_Addr value,
{
// For SIZE == 64:
// .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
- // .word 0x6666; rex64; call __tls_get_addr
+ // .word 0x6666; rex64; call __tls_get_addr@PLT
+ // ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
+ // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
+ // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
// ==> movq %fs:0,%rax; addq x@gottpoff(%rip),%rax
// For SIZE == 32:
// leaq foo@tlsgd(%rip),%rdi;
- // .word 0x6666; rex64; call __tls_get_addr
+ // .word 0x6666; rex64; call __tls_get_addr@PLT
+ // ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
+ // leaq foo@tlsgd(%rip),%rdi;
+ // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
// ==> movl %fs:0,%eax; addq x@gottpoff(%rip),%rax
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
- (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
+ (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
+ || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
if (size == 64)
{
{
// For SIZE == 64:
// .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
- // .word 0x6666; rex64; call __tls_get_addr
+ // .word 0x6666; rex64; call __tls_get_addr@PLT
+ // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
+ // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
+ // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
// ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
// For SIZE == 32:
// leaq foo@tlsgd(%rip),%rdi;
- // .word 0x6666; rex64; call __tls_get_addr
+ // .word 0x6666; rex64; call __tls_get_addr@PLT
+ // ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
+ // leaq foo@tlsgd(%rip),%rdi;
+ // .word 0x66; rex64; call *__tls_get_addr@GOTPCREL(%rip)
// ==> movl %fs:0,%eax; leaq x@tpoff(%rax),%rax
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 12);
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
- (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0));
+ (memcmp(view + 4, "\x66\x66\x48\xe8", 4) == 0
+ || memcmp(view + 4, "\x66\x48\xff", 3) == 0));
if (size == 64)
{
Target_x86_64<size>::Relocate::tls_desc_gd_to_ie(
const Relocate_info<size, false>* relinfo,
size_t relnum,
- Output_segment*,
const elfcpp::Rela<size, false>& rela,
unsigned int r_type,
typename elfcpp::Elf_types<size>::Elf_Addr value,
{
if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
{
- // leaq foo@tlsdesc(%rip), %rax
- // ==> movq foo@gottpoff(%rip), %rax
+ // LP64: leaq foo@tlsdesc(%rip), %rax
+ // ==> movq foo@gottpoff(%rip), %rax
+ // X32: rex leal foo@tlsdesc(%rip), %eax
+ // ==> rex movl foo@gottpoff(%rip), %eax
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[-3] & 0xfb) == 0x48
+ || (size == 32 && (view[-3] & 0xfb) == 0x40))
+ && view[-2] == 0x8d
+ && (view[-1] & 0xc7) == 0x05));
view[-2] = 0x8b;
const elfcpp::Elf_Xword addend = rela.get_r_addend();
Relocate_functions<size, false>::pcrela32(view, value, addend, address);
}
else
{
- // call *foo@tlscall(%rax)
- // ==> nop; nop
+ // LP64: call *foo@tlscall(%rax)
+ // ==> xchg %ax, %ax
+ // X32: call *foo@tlscall(%eax)
+ // ==> nopl (%rax)
gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
+ int prefix = 0;
+ if (size == 32 && view[0] == 0x67)
+ {
+ tls::check_range(relinfo, relnum, rela.get_r_offset(),
+ view_size, 3);
+ prefix = 1;
+ }
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
- view[0] == 0xff && view[1] == 0x10);
- view[0] = 0x66;
- view[1] = 0x90;
+ view[prefix] == 0xff && view[prefix + 1] == 0x10);
+ if (prefix)
+ {
+ view[0] = 0x0f;
+ view[1] = 0x1f;
+ view[2] = 0x00;
+ }
+ else
+ {
+ view[0] = 0x66;
+ view[1] = 0x90;
+ }
}
}
{
if (r_type == elfcpp::R_X86_64_GOTPC32_TLSDESC)
{
- // leaq foo@tlsdesc(%rip), %rax
- // ==> movq foo@tpoff, %rax
+ // LP64: leaq foo@tlsdesc(%rip), %rax
+ // ==> movq foo@tpoff, %rax
+ // X32: rex leal foo@tlsdesc(%rip), %eax
+ // ==> rex movl foo@tpoff, %eax
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[-3] & 0xfb) == 0x48
+ || (size == 32 && (view[-3] & 0xfb) == 0x40))
+ && view[-2] == 0x8d
+ && (view[-1] & 0xc7) == 0x05));
+ view[-3] = (view[-3] & 0x48) | ((view[-3] >> 2) & 1);
view[-2] = 0xc7;
- view[-1] = 0xc0;
+ view[-1] = 0xc0 | ((view[-1] >> 3) & 7);
value -= tls_segment->memsz();
Relocate_functions<size, false>::rela32(view, value, 0);
}
else
{
- // call *foo@tlscall(%rax)
- // ==> nop; nop
+ // LP64: call *foo@tlscall(%rax)
+ // ==> xchg %ax, %ax
+ // X32: call *foo@tlscall(%eax)
+ // ==> nopl (%rax)
gold_assert(r_type == elfcpp::R_X86_64_TLSDESC_CALL);
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 2);
+ int prefix = 0;
+ if (size == 32 && view[0] == 0x67)
+ {
+ tls::check_range(relinfo, relnum, rela.get_r_offset(),
+ view_size, 3);
+ prefix = 1;
+ }
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
- view[0] == 0xff && view[1] == 0x10);
- view[0] = 0x66;
- view[1] = 0x90;
+ view[prefix] == 0xff && view[prefix + 1] == 0x10);
+ if (prefix)
+ {
+ view[0] = 0x0f;
+ view[1] = 0x1f;
+ view[2] = 0x00;
+ }
+ else
+ {
+ view[0] = 0x66;
+ view[1] = 0x90;
+ }
}
}
// For SIZE == 32:
// ... leq foo@dtpoff(%rax),%reg
// ==> nopl 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
+ // leaq foo@tlsld(%rip),%rdi; call *__tls_get_addr@GOTPCREL(%rip)
+ // For SIZE == 64:
+ // ... leq foo@dtpoff(%rax),%reg
+ // ==> .word 0x6666; .byte 0x6666; movq %fs:0,%rax ... leaq x@tpoff(%rax),%rdx
+ // For SIZE == 32:
+ // ... leq foo@dtpoff(%rax),%reg
+ // ==> nopw 0x0(%rax); movl %fs:0,%eax ... leaq x@tpoff(%rax),%rdx
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, -3);
tls::check_range(relinfo, relnum, rela.get_r_offset(), view_size, 9);
tls::check_tls(relinfo, relnum, rela.get_r_offset(),
view[-3] == 0x48 && view[-2] == 0x8d && view[-1] == 0x3d);
- tls::check_tls(relinfo, relnum, rela.get_r_offset(), view[4] == 0xe8);
+ tls::check_tls(relinfo, relnum, rela.get_r_offset(),
+ view[4] == 0xe8 || view[4] == 0xff);
- if (size == 64)
- memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
+ if (view[4] == 0xe8)
+ {
+ if (size == 64)
+ memcpy(view - 3, "\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0", 12);
+ else
+ memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
+ }
else
- memcpy(view - 3, "\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0", 12);
+ {
+ if (size == 64)
+ memcpy(view - 3, "\x66\x66\x66\x66\x64\x48\x8b\x04\x25\0\0\0\0",
+ 13);
+ else
+ memcpy(view - 3, "\x66\x0f\x1f\x40\x00\x64\x8b\x04\x25\0\0\0\0",
+ 13);
+ }
// The next reloc should be a PLT32 reloc against __tls_get_addr.
// We can skip it.
// movq
if (op1 == 0x4c)
view[-3] = 0x49;
+ else if (size == 32 && op1 == 0x44)
+ view[-3] = 0x41;
view[-2] = 0xc7;
view[-1] = 0xc0 | reg;
}
// Special handling for %rsp.
if (op1 == 0x4c)
view[-3] = 0x49;
+ else if (size == 32 && op1 == 0x44)
+ view[-3] = 0x41;
view[-2] = 0x81;
view[-1] = 0xc0 | reg;
}
// addq
if (op1 == 0x4c)
view[-3] = 0x4d;
+ else if (size == 32 && op1 == 0x44)
+ view[-3] = 0x45;
view[-2] = 0x8d;
view[-1] = 0x80 | reg | (reg << 3);
}
- value -= tls_segment->memsz();
+ if (tls_segment != NULL)
+ value -= tls_segment->memsz();
Relocate_functions<size, false>::rela32(view, value, 0);
}
section_size_type view_size,
const Reloc_symbol_changes* reloc_symbol_changes)
{
+ typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
+ Classify_reloc;
+
gold_assert(sh_type == elfcpp::SHT_RELA);
- gold::relocate_section<size, false, Target_x86_64<size>, elfcpp::SHT_RELA,
- typename Target_x86_64<size>::Relocate,
- gold::Default_comdat_behavior>(
+ gold::relocate_section<size, false, Target_x86_64<size>, Relocate,
+ gold::Default_comdat_behavior, Classify_reloc>(
relinfo,
this,
prelocs,
view_size);
}
-// Return the size of a relocation while scanning during a relocatable
-// link.
+// Scan the relocs during a relocatable link.
template<int size>
-unsigned int
-Target_x86_64<size>::Relocatable_size_for_reloc::get_size_for_reloc(
- unsigned int r_type,
- Relobj* object)
+void
+Target_x86_64<size>::scan_relocatable_relocs(
+ Symbol_table* symtab,
+ Layout* layout,
+ Sized_relobj_file<size, 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)
{
- 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_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;
+ typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
+ Classify_reloc;
+ typedef gold::Default_scan_relocatable_relocs<Classify_reloc>
+ Scan_relocatable_relocs;
- 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:
- 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:
- case elfcpp::R_X86_64_TLSDESC:
- object->error(_("unexpected reloc %u in object file"), r_type);
- return 0;
+ gold_assert(sh_type == elfcpp::SHT_RELA);
- 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;
- }
+ gold::scan_relocatable_relocs<size, false, Scan_relocatable_relocs>(
+ symtab,
+ layout,
+ object,
+ data_shndx,
+ prelocs,
+ reloc_count,
+ output_section,
+ needs_special_offset_handling,
+ local_symbol_count,
+ plocal_symbols,
+ rr);
}
-// Scan the relocs during a relocatable link.
+// Scan the relocs for --emit-relocs.
template<int size>
void
-Target_x86_64<size>::scan_relocatable_relocs(
+Target_x86_64<size>::emit_relocs_scan(
Symbol_table* symtab,
Layout* layout,
Sized_relobj_file<size, false>* object,
Output_section* output_section,
bool needs_special_offset_handling,
size_t local_symbol_count,
- const unsigned char* plocal_symbols,
+ const unsigned char* plocal_syms,
Relocatable_relocs* rr)
{
- gold_assert(sh_type == elfcpp::SHT_RELA);
+ typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
+ Classify_reloc;
+ typedef gold::Default_emit_relocs_strategy<Classify_reloc>
+ Emit_relocs_strategy;
- typedef gold::Default_scan_relocatable_relocs<elfcpp::SHT_RELA,
- Relocatable_size_for_reloc> Scan_relocatable_relocs;
+ gold_assert(sh_type == elfcpp::SHT_RELA);
- gold::scan_relocatable_relocs<size, false, elfcpp::SHT_RELA,
- Scan_relocatable_relocs>(
+ gold::scan_relocatable_relocs<size, false, Emit_relocs_strategy>(
symtab,
layout,
object,
output_section,
needs_special_offset_handling,
local_symbol_count,
- plocal_symbols,
+ plocal_syms,
rr);
}
size_t reloc_count,
Output_section* output_section,
typename elfcpp::Elf_types<size>::Elf_Off offset_in_output_section,
- const Relocatable_relocs* rr,
unsigned char* view,
typename elfcpp::Elf_types<size>::Elf_Addr view_address,
section_size_type view_size,
unsigned char* reloc_view,
section_size_type reloc_view_size)
{
+ typedef gold::Default_classify_reloc<elfcpp::SHT_RELA, size, false>
+ Classify_reloc;
+
gold_assert(sh_type == elfcpp::SHT_RELA);
- gold::relocate_relocs<size, false, elfcpp::SHT_RELA>(
+ gold::relocate_relocs<size, false, Classify_reloc>(
relinfo,
prelocs,
reloc_count,
output_section,
offset_in_output_section,
- rr,
view,
view_address,
view_size,
// code. We have to change the function so that it always ensures
// that it has enough stack space to run some random function.
+static const unsigned char cmp_insn_32[] = { 0x64, 0x3b, 0x24, 0x25 };
+static const unsigned char lea_r10_insn_32[] = { 0x44, 0x8d, 0x94, 0x24 };
+static const unsigned char lea_r11_insn_32[] = { 0x44, 0x8d, 0x9c, 0x24 };
+
+static const unsigned char cmp_insn_64[] = { 0x64, 0x48, 0x3b, 0x24, 0x25 };
+static const unsigned char lea_r10_insn_64[] = { 0x4c, 0x8d, 0x94, 0x24 };
+static const unsigned char lea_r11_insn_64[] = { 0x4c, 0x8d, 0x9c, 0x24 };
+
template<int size>
void
Target_x86_64<size>::do_calls_non_split(Relobj* object, unsigned int shndx,
section_offset_type fnoffset,
section_size_type fnsize,
+ const unsigned char*,
+ size_t,
unsigned char* view,
section_size_type view_size,
std::string* from,
std::string* to) const
{
+ const char* const cmp_insn = reinterpret_cast<const char*>
+ (size == 32 ? cmp_insn_32 : cmp_insn_64);
+ const char* const lea_r10_insn = reinterpret_cast<const char*>
+ (size == 32 ? lea_r10_insn_32 : lea_r10_insn_64);
+ const char* const lea_r11_insn = reinterpret_cast<const char*>
+ (size == 32 ? lea_r11_insn_32 : lea_r11_insn_64);
+
+ const size_t cmp_insn_len =
+ (size == 32 ? sizeof(cmp_insn_32) : sizeof(cmp_insn_64));
+ const size_t lea_r10_insn_len =
+ (size == 32 ? sizeof(lea_r10_insn_32) : sizeof(lea_r10_insn_64));
+ const size_t lea_r11_insn_len =
+ (size == 32 ? sizeof(lea_r11_insn_32) : sizeof(lea_r11_insn_64));
+ const size_t nop_len = (size == 32 ? 7 : 8);
+
// 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)
+ if (this->match_view(view, view_size, fnoffset, cmp_insn, cmp_insn_len)
+ && fnsize > nop_len + 1)
{
// 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);
+ this->set_view_to_nop(view, view_size, fnoffset + 1, nop_len);
}
// lea NN(%rsp),%r10
// lea NN(%rsp),%r11
else if ((this->match_view(view, view_size, fnoffset,
- "\x4c\x8d\x94\x24", 4)
+ lea_r10_insn, lea_r10_insn_len)
|| this->match_view(view, view_size, fnoffset,
- "\x4c\x8d\x9c\x24", 4))
+ lea_r11_insn, lea_r11_insn_len))
&& fnsize > 8)
{
// This is loading an offset from the stack pointer for a
public:
Output_data_plt_x86_64_nacl(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative)
: Output_data_plt_x86_64<size>(layout, plt_entry_size,
got, got_plt, got_irelative)
Output_data_plt_x86_64_nacl(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative,
unsigned int plt_count)
: Output_data_plt_x86_64<size>(layout, plt_entry_size,
virtual Output_data_plt_x86_64<size>*
do_make_data_plt(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative)
{
return new Output_data_plt_x86_64_nacl<size>(layout, got, got_plt,
virtual Output_data_plt_x86_64<size>*
do_make_data_plt(Layout* layout,
Output_data_got<64, false>* got,
- Output_data_space* got_plt,
+ Output_data_got_plt_x86_64* got_plt,
Output_data_space* got_irelative,
unsigned int plt_count)
{
elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
NULL, // attributes_section
NULL, // attributes_vendor
- "_start" // entry_symbol_name
+ "_start", // entry_symbol_name
+ 32, // hash_entry_size
+ elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
};
template<>
elfcpp::SHF_X86_64_LARGE, // large_common_section_flags
NULL, // attributes_section
NULL, // attributes_vendor
- "_start" // entry_symbol_name
+ "_start", // entry_symbol_name
+ 32, // hash_entry_size
+ elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
};
#define NACLMASK 0xe0 // 32-byte alignment mask.
projects / deliverable / binutils-gdb.git / blobdiff