// x86_64.cc -- x86_64 target support for gold.
-// Copyright (C) 2006-2016 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.
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;
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
{
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.
// 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
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)
- {
- return new Output_data_plt_x86_64_standard<size>(layout, got, got_plt,
- got_irelative);
- }
+ 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_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>*,
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_undefined()
+ || gsym->is_predefined()
|| gsym->is_from_dynobj()
|| gsym->is_preemptible())
return false;
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;
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<>
NULL, // attributes_vendor
"_start", // entry_symbol_name
32, // hash_entry_size
+ elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
};
template<>
NULL, // attributes_vendor
"_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
return this->rela_irelative_;
}
+// Record a target-specific program property from the .note.gnu.property
+// section.
+template<int size>
+void
+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)
+{
+ uint32_t val = 0;
+
+ 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.
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.
{
// Check PC-relative offset overflow in PLT entry.
uint64_t plt_got_pcrel_offset = (got_address + got_offset
- - (plt_address + plt_offset + 6));
+ - (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,
+ plt_got_pcrel_offset);
+
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
+ elfcpp::Swap<32, false>::writeval(pov + 12,
+ - (plt_offset + plt_entry_size));
+
+ return 6;
+}
+
+// The reserved TLSDESC entry in the PLT for an executable.
+
+template<int size>
+const unsigned char
+Output_data_plt_x86_64_standard<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)
+ 0xff, 0x25, // jmpq *y(%rip)
+ 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
+ 0x0f, 0x1f, // nop
+ 0x40, 0
+};
+
+template<int size>
+void
+Output_data_plt_x86_64_standard<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 + 8,
+ (got_base
+ + tlsdesc_got_offset
+ - (plt_address + plt_offset
+ + 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 PLT entry %d"),
+ gold_error(_("PC-relative offset overflow in APLT entry %d"),
plt_index + 1);
- memcpy(pov, plt_entry, plt_entry_size);
- elfcpp::Swap_unaligned<32, false>::writeval(pov + 2,
- plt_got_pcrel_offset);
-
- elfcpp::Swap_unaligned<32, false>::writeval(pov + 7, plt_index);
- elfcpp::Swap<32, false>::writeval(pov + 12,
- - (plt_offset + plt_entry_size));
-
- return 6;
+ 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 PLT for an executable.
+// The reserved TLSDESC entry in the IBT PLT for an executable.
template<int size>
const unsigned char
-Output_data_plt_x86_64_standard<size>::tlsdesc_plt_entry[plt_entry_size] =
+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)
- 0xff, 0x25, // jmpq *y(%rip)
- 0, 0, 0, 0, // replaced with offset of reserved TLSDESC_GOT entry
- 0x0f, 0x1f, // nop
- 0x40, 0
+ 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_standard<size>::do_fill_tlsdesc_entry(
+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,
(got_address + 8
- (plt_address + plt_offset
+ 6)));
- elfcpp::Swap_unaligned<32, false>::writeval(pov + 8,
+ elfcpp::Swap_unaligned<32, false>::writeval(pov + 9,
(got_base
+ tlsdesc_got_offset
- (plt_address + plt_offset
- + 12)));
+ + 13)));
}
// The .eh_frame unwind information for the PLT.
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.
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.
+ 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);
+}
+
// Create the PLT section.
template<int 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>
// mov foo@GOTPCREL(%rip), %reg
// to lea foo(%rip), %reg.
// in Relocate::relocate.
- if ((r_type == elfcpp::R_X86_64_GOTPCREL
- || r_type == elfcpp::R_X86_64_GOTPCRELX
- || r_type == elfcpp::R_X86_64_REX_GOTPCRELX)
+ 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)
{
break;
}
-
// The symbol requires a GOT entry.
unsigned int r_sym = elfcpp::elf_r_sym<size>(reloc.get_r_info());
// 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)
{
{
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.
// (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 (r_offset >= 2
+ if (!parameters->incremental()
+ && r_offset >= 2
&& Target_x86_64<size>::can_convert_mov_to_lea(gsym, r_type,
r_offset, &view))
break;
- if (r_offset >= 2
+ if (!parameters->incremental()
+ && r_offset >= 2
&& Target_x86_64<size>::can_convert_callq_to_direct(gsym, r_type,
r_offset,
&view))
case elfcpp::R_X86_64_GOT64:
case elfcpp::R_X86_64_GOTPLT64:
- // R_X86_64_GOTPLT64 is obsolete and treated the the same as
+ // R_X86_64_GOTPLT64 is obsolete and treated the same as
// GOT64.
gold_assert(have_got_offset);
Reloc_funcs::rela64(view, got_offset, addend);
case elfcpp::R_X86_64_GOTOFF64:
{
- typename elfcpp::Elf_types<size>::Elf_Addr value;
- value = (psymval->value(object, 0)
- - target->got_plt_section()->address());
- Reloc_funcs::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;
// mov foo@GOTPCREL(%rip), %reg
// to lea foo(%rip), %reg.
// if possible.
- if ((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)))
+ 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);
// and jmpq *foo@GOTPCRELX(%rip) to
// jmpq foo
// nop
- else if (gsym != NULL
+ else if (!parameters->incremental()
+ && gsym != NULL
&& rela.get_r_offset() >= 2
&& Target_x86_64<size>::can_convert_callq_to_direct(gsym,
r_type,
if (gsym != NULL)
{
gold_assert(gsym->has_got_offset(GOT_TYPE_STANDARD));
- got_offset = gsym->got_offset(GOT_TYPE_STANDARD) - target->got_size();
+ 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));
+ 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());
}
{
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;
+ }
}
}
NULL, // attributes_vendor
"_start", // entry_symbol_name
32, // hash_entry_size
+ elfcpp::SHT_X86_64_UNWIND, // unwind_section_type
};
template<>
NULL, // attributes_vendor
"_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