// http://www.x86-64.org/documentation/abi.pdf
// TLS info comes from
// http://people.redhat.com/drepper/tls.pdf
-// http://ia32-abi.googlegroups.com/web/RFC-TLSDESC-x86.txt?gda=kWQJPEQAAACEfYQFX0dubPQ2NuO4whhjkR4HAp8tBMb_I0iuUeQslmG1qiJ7UbTIup-M2XPURDRiZJyPR4BqKR2agJ-5jfT5Ley2_-oiOJ4zLNAGCw24Bg
+// http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt
class Target_x86_64 : public Sized_target<64, false>
{
Target_x86_64()
: Sized_target<64, false>(&x86_64_info),
- got_(NULL), plt_(NULL), got_plt_(NULL), rel_dyn_(NULL),
+ got_(NULL), plt_(NULL), got_plt_(NULL), rela_dyn_(NULL),
copy_relocs_(NULL), dynbss_(NULL)
{ }
// Get the dynamic reloc section, creating it if necessary.
Reloc_section*
- rel_dyn_section(Layout*);
+ rela_dyn_section(Layout*);
// Copy a relocation against a global symbol.
void
// The GOT PLT section.
Output_data_space* got_plt_;
// The dynamic reloc section.
- Reloc_section* rel_dyn_;
+ Reloc_section* rela_dyn_;
// Relocs saved to avoid a COPY reloc.
Copy_relocs<64, false>* copy_relocs_;
// Space for variables copied with a COPY reloc.
// Get the dynamic reloc section, creating it if necessary.
Target_x86_64::Reloc_section*
-Target_x86_64::rel_dyn_section(Layout* layout)
+Target_x86_64::rela_dyn_section(Layout* layout)
{
- if (this->rel_dyn_ == NULL)
+ if (this->rela_dyn_ == NULL)
{
gold_assert(layout != NULL);
- this->rel_dyn_ = new Reloc_section();
+ this->rela_dyn_ = new Reloc_section();
layout->add_output_section_data(".rela.dyn", elfcpp::SHT_RELA,
- elfcpp::SHF_ALLOC, this->rel_dyn_);
+ elfcpp::SHF_ALLOC, this->rela_dyn_);
}
- return this->rel_dyn_;
+ return this->rela_dyn_;
}
// A class to handle the PLT data.
// Add the COPY reloc.
ssym->set_needs_dynsym_entry();
- Reloc_section* rel_dyn = this->rel_dyn_section(layout);
- rel_dyn->add_global(ssym, elfcpp::R_X86_64_COPY, dynbss, offset, 0);
+ Reloc_section* rela_dyn = this->rela_dyn_section(layout);
+ rela_dyn->add_global(ssym, elfcpp::R_X86_64_COPY, dynbss, offset, 0);
}
}
// executable, we can switch to Local-Exec.
return elfcpp::R_X86_64_TPOFF32;
+ case elfcpp::R_X86_64_DTPOFF32:
+ // Another Local-Dynamic reloc.
+ return elfcpp::R_X86_64_TPOFF32;
+
+ case elfcpp::R_X86_64_DTPOFF64:
+ // Another Local-Dynamic reloc.
+ return elfcpp::R_X86_64_TPOFF64;
+
case elfcpp::R_X86_64_GOTTPOFF:
// These are Initial-Exec relocs which get the thread offset
// from the GOT. If we know that we are linking against the
Layout* layout,
Target_x86_64* target,
Sized_relobj<64, false>* object,
- unsigned int,
- const elfcpp::Rela<64, false>&,
+ unsigned int data_shndx,
+ const elfcpp::Rela<64, false>& reloc,
unsigned int r_type,
const elfcpp::Sym<64, false>&)
{
target->got_section(symtab, layout);
break;
+ case elfcpp::R_X86_64_GOT64:
+ case elfcpp::R_X86_64_GOT32:
+ case elfcpp::R_X86_64_GOTPCREL64:
+ case elfcpp::R_X86_64_GOTPCREL:
+ {
+ // The symbol requires a GOT entry.
+ Output_data_got<64, false>* got = target->got_section(symtab, layout);
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(reloc.get_r_info());
+ if (got->add_local(object, r_sym))
+ {
+ // If we are generating a shared object, we need to add a
+ // dynamic RELATIVE relocation for this symbol.
+ if (parameters->output_is_shared())
+ {
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ rela_dyn->add_local(object, 0, elfcpp::R_X86_64_RELATIVE,
+ data_shndx, reloc.get_r_offset(), 0);
+ }
+ }
+ }
+ break;
+
case elfcpp::R_X86_64_COPY:
case elfcpp::R_X86_64_GLOB_DAT:
case elfcpp::R_X86_64_JUMP_SLOT:
// 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_DTPOFF64:
- case elfcpp::R_X86_64_DTPOFF32:
case elfcpp::R_X86_64_TLSDESC:
fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
program_name, object->name().c_str(), r_type);
case elfcpp::R_X86_64_TPOFF32: // TODO(csilvers): correct?
case elfcpp::R_X86_64_GOTPC32_TLSDESC: // TODO(csilvers): correct?
case elfcpp::R_X86_64_TLSDESC_CALL: // TODO(csilvers): correct?
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
{
bool output_is_shared = parameters->output_is_shared();
r_type = Target_x86_64::optimize_tls_reloc(!output_is_shared, r_type);
switch (r_type)
{
case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ case elfcpp::R_X86_64_TPOFF64:
// FIXME: If generating a shared object, we need to copy
// this relocation into the object.
gold_assert(!output_is_shared);
break;
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ break;
+
case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
case elfcpp::R_X86_64_TLSGD: // General Dynamic
case elfcpp::R_X86_64_TLSLD: // Local Dynamic
}
break;
- case elfcpp::R_X86_64_GOT64: // TODO(csilvers): correct?
- case elfcpp::R_X86_64_GOT32:
- case elfcpp::R_X86_64_GOTPCREL64: // TODO(csilvers): correct?
- case elfcpp::R_X86_64_GOTPCREL:
- case elfcpp::R_X86_64_GOTPLT64: // TODO(csilvers): correct?
+ case elfcpp::R_X86_64_GOTPLT64:
case elfcpp::R_X86_64_PLT32:
case elfcpp::R_X86_64_SIZE32: // TODO(csilvers): correct?
case elfcpp::R_X86_64_SIZE64: // TODO(csilvers): correct?
// dynamic relocation for it.
if (!gsym->final_value_is_known())
{
- Reloc_section* rel_dyn = target->rel_dyn_section(layout);
- rel_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT, got,
- gsym->got_offset(), 0);
+ Reloc_section* rela_dyn = target->rela_dyn_section(layout);
+ rela_dyn->add_global(gsym, elfcpp::R_X86_64_GLOB_DAT, got,
+ gsym->got_offset(), 0);
}
}
}
// 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_DTPOFF64:
- case elfcpp::R_X86_64_DTPOFF32:
case elfcpp::R_X86_64_TLSDESC:
fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
program_name, object->name().c_str(), r_type);
case elfcpp::R_X86_64_TPOFF32: // TODO(csilvers): correct?
case elfcpp::R_X86_64_GOTPC32_TLSDESC: // TODO(csilvers): correct?
case elfcpp::R_X86_64_TLSDESC_CALL: // TODO(csilvers): correct?
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
{
const bool is_final = gsym->final_value_is_known();
r_type = Target_x86_64::optimize_tls_reloc(is_final, r_type);
switch (r_type)
{
case elfcpp::R_X86_64_TPOFF32: // Local-exec
+ case elfcpp::R_X86_64_TPOFF64:
// FIXME: If generating a shared object, we need to copy
// this relocation into the object.
gold_assert(!parameters->output_is_shared());
break;
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ break;
+
case elfcpp::R_X86_64_GOTTPOFF: // Initial-exec
case elfcpp::R_X86_64_TLSGD: // General Dynamic
case elfcpp::R_X86_64_TLSLD: // Local Dynamic
odyn->add_constant(elfcpp::DT_PLTREL, elfcpp::DT_RELA);
}
- if (this->rel_dyn_ != NULL)
+ if (this->rela_dyn_ != NULL)
{
- const Output_data* od = this->rel_dyn_;
+ const Output_data* od = this->rela_dyn_;
odyn->add_section_address(elfcpp::DT_RELA, od);
odyn->add_section_size(elfcpp::DT_RELASZ, od);
odyn->add_constant(elfcpp::DT_RELAENT,
return;
if (this->copy_relocs_->any_to_emit())
{
- Reloc_section* rel_dyn = this->rel_dyn_section(layout);
- this->copy_relocs_->emit(rel_dyn);
+ Reloc_section* rela_dyn = this->rela_dyn_section(layout);
+ this->copy_relocs_->emit(rela_dyn);
}
delete this->copy_relocs_;
this->copy_relocs_ = NULL;
Target_x86_64::Relocate::relocate(const Relocate_info<64, false>* relinfo,
Target_x86_64* target,
size_t relnum,
- const elfcpp::Rela<64, false>& rel,
+ const elfcpp::Rela<64, false>& rela,
unsigned int r_type,
const Sized_symbol<64>* gsym,
const Symbol_value<64>* psymval,
{
if (r_type != elfcpp::R_X86_64_PLT32
|| gsym == NULL
- || strcmp(gsym->name(), "___tls_get_addr") != 0)
+ || strcmp(gsym->name(), "__tls_get_addr") != 0)
{
fprintf(stderr, _("%s: %s: missing expected TLS relocation\n"),
program_name,
- relinfo->location(relnum, rel.get_r_offset()).c_str());
+ relinfo->location(relnum, rela.get_r_offset()).c_str());
gold_exit(false);
}
}
const Sized_relobj<64, false>* object = relinfo->object;
- const elfcpp::Elf_Xword addend = rel.get_r_addend();
+ const elfcpp::Elf_Xword addend = rela.get_r_addend();
+
+ // Get the GOT offset if needed.
+ bool have_got_offset = false;
+ unsigned int got_offset = 0;
+ switch (r_type)
+ {
+ case elfcpp::R_X86_64_GOT32:
+ case elfcpp::R_X86_64_GOT64:
+ case elfcpp::R_X86_64_GOTPLT64:
+ case elfcpp::R_X86_64_GOTPCREL:
+ case elfcpp::R_X86_64_GOTPCREL64:
+ if (gsym != NULL)
+ {
+ gold_assert(gsym->has_got_offset());
+ got_offset = gsym->got_offset();
+ }
+ else
+ {
+ unsigned int r_sym = elfcpp::elf_r_sym<64>(rela.get_r_info());
+ got_offset = object->local_got_offset(r_sym);
+ }
+ have_got_offset = true;
+ break;
+
+ default:
+ break;
+ }
+
switch (r_type)
{
break;
case elfcpp::R_X86_64_GOT32:
- // Local GOT offsets not yet supported.
- gold_assert(gsym);
- gold_assert(gsym->has_got_offset());
- Relocate_functions<64, false>::rela32(view, gsym->got_offset(), addend);
+ gold_assert(have_got_offset);
+ Relocate_functions<64, false>::rela32(view, got_offset, addend);
break;
case elfcpp::R_X86_64_GOTPC32:
// 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: // TODO(csilvers): correct?
- // Local GOT offsets not yet supported.
- gold_assert(gsym);
- gold_assert(gsym->has_got_offset());
- Relocate_functions<64, false>::rela64(view, gsym->got_offset(), addend);
+ gold_assert(have_got_offset);
+ Relocate_functions<64, false>::rela64(view, got_offset, addend);
break;
case elfcpp::R_X86_64_GOTPC64:
case elfcpp::R_X86_64_GOTPCREL:
{
- // Local GOT offsets not yet supported.
- gold_assert(gsym);
- gold_assert(gsym->has_got_offset());
- elfcpp::Elf_types<64>::Elf_Addr value;
- value = (target->got_section(NULL, NULL)->address()
- + gsym->got_offset());
- Relocate_functions<64, false>::pcrela32(view, value, addend, address);
+ gold_assert(have_got_offset);
+ elfcpp::Elf_types<64>::Elf_Addr value;
+ value = target->got_section(NULL, NULL)->address() + got_offset;
+ Relocate_functions<64, false>::pcrela32(view, value, addend, address);
}
break;
case elfcpp::R_X86_64_GOTPCREL64:
{
- // Local GOT offsets not yet supported.
- gold_assert(gsym);
- gold_assert(gsym->has_got_offset());
- elfcpp::Elf_types<64>::Elf_Addr value;
- value = (target->got_section(NULL, NULL)->address()
- + gsym->got_offset());
- Relocate_functions<64, false>::pcrela64(view, value, addend, address);
+ gold_assert(have_got_offset);
+ elfcpp::Elf_types<64>::Elf_Addr value;
+ value = target->got_section(NULL, NULL)->address() + got_offset;
+ Relocate_functions<64, false>::pcrela64(view, value, addend, address);
}
break;
// 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_DTPOFF64:
- case elfcpp::R_X86_64_DTPOFF32:
case elfcpp::R_X86_64_TLSDESC:
fprintf(stderr, _("%s: %s: unexpected reloc %u in object file\n"),
program_name,
- relinfo->location(relnum, rel.get_r_offset()).c_str(),
+ relinfo->location(relnum, rela.get_r_offset()).c_str(),
r_type);
gold_exit(false);
break;
case elfcpp::R_X86_64_TPOFF32: // TODO(csilvers): correct?
case elfcpp::R_X86_64_GOTPC32_TLSDESC: // TODO(csilvers): correct?
case elfcpp::R_X86_64_TLSDESC_CALL: // TODO(csilvers): correct?
- this->relocate_tls(relinfo, relnum, rel, r_type, gsym, psymval, view,
+ case elfcpp::R_X86_64_DTPOFF32:
+ case elfcpp::R_X86_64_DTPOFF64:
+ this->relocate_tls(relinfo, relnum, rela, r_type, gsym, psymval, view,
address, view_size);
break;
default:
fprintf(stderr, _("%s: %s: unsupported reloc %u\n"),
program_name,
- relinfo->location(relnum, rel.get_r_offset()).c_str(),
+ relinfo->location(relnum, rela.get_r_offset()).c_str(),
r_type);
gold_exit(false);
break;
r_type);
gold_exit(false);
break;
+
+ case elfcpp::R_X86_64_DTPOFF32:
+ if (opt_r_type == elfcpp::R_X86_64_TPOFF32)
+ value = value - (tls_segment->vaddr() + tls_segment->memsz());
+ else
+ value = value - tls_segment->vaddr();
+ Relocate_functions<64, false>::rel32(view, value);
+ break;
+
+ case elfcpp::R_X86_64_DTPOFF64:
+ if (opt_r_type == elfcpp::R_X86_64_TPOFF64)
+ value = value - (tls_segment->vaddr() + tls_segment->memsz());
+ else
+ value = value - tls_segment->vaddr();
+ Relocate_functions<64, false>::rel64(view, value);
+ break;
}
}
unsigned char* view,
off_t view_size)
{
- // We have to actually change the instructions, which means that we
- // need to examine the opcodes to figure out which instruction we
+ // We need to examine the opcodes to figure out which instruction we
// are looking at.
- // movl %gs:XX,%eax ==> movl $YY,%eax
- // movl %gs:XX,%reg ==> movl $YY,%reg
- // addl %gs:XX,%reg ==> addl $YY,%reg
- Target_x86_64::Relocate::check_range(relinfo, relnum, rel, view_size, -1);
+ // movq foo@gottpoff(%rip),%reg ==> movq $YY,%reg
+ // addq foo@gottpoff(%rip),%reg ==> addq $YY,%reg
+
+ Target_x86_64::Relocate::check_range(relinfo, relnum, rel, view_size, -3);
Target_x86_64::Relocate::check_range(relinfo, relnum, rel, view_size, 4);
- unsigned char op1 = view[-1];
- if (op1 == 0xa1)
+ unsigned char op1 = view[-3];
+ unsigned char op2 = view[-2];
+ unsigned char op3 = view[-1];
+ unsigned char reg = op3 >> 3;
+
+ if (op2 == 0x8b)
+ {
+ // movq
+ if (op1 == 0x4c)
+ view[-3] = 0x49;
+ view[-2] = 0xc7;
+ view[-1] = 0xc0 | reg;
+ }
+ else if (reg == 4)
{
- // movl XX,%eax ==> movl $YY,%eax
- view[-1] = 0xb8;
+ // Special handling for %rsp.
+ if (op1 == 0x4c)
+ view[-3] = 0x49;
+ view[-2] = 0x81;
+ view[-1] = 0xc0 | reg;
}
else
{
- Target_x86_64::Relocate::check_range(relinfo, relnum, rel,
- view_size, -2);
-
- unsigned char op2 = view[-2];
- if (op2 == 0x8b)
- {
- // movl XX,%reg ==> movl $YY,%reg
- Target_x86_64::Relocate::check_tls(relinfo, relnum, rel,
- (op1 & 0xc7) == 0x05);
- view[-2] = 0xc7;
- view[-1] = 0xc0 | ((op1 >> 3) & 7);
- }
- else if (op2 == 0x03)
- {
- // addl XX,%reg ==> addl $YY,%reg
- Target_x86_64::Relocate::check_tls(relinfo, relnum, rel,
- (op1 & 0xc7) == 0x05);
- view[-2] = 0x81;
- view[-1] = 0xc0 | ((op1 >> 3) & 7);
- }
- else
- Target_x86_64::Relocate::check_tls(relinfo, relnum, rel, 0);
+ // addq
+ if (op1 == 0x4c)
+ view[-3] = 0x4d;
+ view[-2] = 0x8d;
+ view[-1] = 0x80 | reg | (reg << 3);
}
value = value - (tls_segment->vaddr() + tls_segment->memsz());
- Relocate_functions<64, false>::rel32(view, value);
+ Relocate_functions<64, false>::rela32(view, value, 0);
}
// Do a relocation in which we convert a TLS Global-Dynamic to a
unsigned char* view,
off_t view_size)
{
- // leal foo(,%reg,1),%eax; call ___tls_get_addr
- // ==> movl %gs,0,%eax; subl $foo@tpoff,%eax
- // leal foo(%reg),%eax; call ___tls_get_addr
- // ==> movl %gs:0,%eax; subl $foo@tpoff,%eax
-
- Target_x86_64::Relocate::check_range(relinfo, relnum, rel, view_size, -2);
- Target_x86_64::Relocate::check_range(relinfo, relnum, rel, view_size, 9);
+ // .byte 0x66; leaq foo@tlsgd(%rip),%rdi;
+ // .word 0x6666; rex64; call __tls_get_addr
+ // ==> movq %fs:0,%rax; leaq x@tpoff(%rax),%rax
- unsigned char op1 = view[-1];
- unsigned char op2 = view[-2];
+ Target_x86_64::Relocate::check_range(relinfo, relnum, rel, view_size, -4);
+ Target_x86_64::Relocate::check_range(relinfo, relnum, rel, view_size, 12);
Target_x86_64::Relocate::check_tls(relinfo, relnum, rel,
- op2 == 0x8d || op2 == 0x04);
+ (memcmp(view - 4, "\x66\x48\x8d\x3d", 4)
+ == 0));
Target_x86_64::Relocate::check_tls(relinfo, relnum, rel,
- view[4] == 0xe8);
+ (memcmp(view + 4, "\x66\x66\x48\xe8", 4)
+ == 0));
- int roff = 5;
+ memcpy(view - 4, "\x64\x48\x8b\x04\x25\0\0\0\0\x48\x8d\x80\0\0\0\0", 16);
- if (op2 == 0x04)
- {
- Target_x86_64::Relocate::check_range(relinfo, relnum, rel, view_size, -3);
- Target_x86_64::Relocate::check_tls(relinfo, relnum, rel,
- view[-3] == 0x8d);
- Target_x86_64::Relocate::check_tls(relinfo, relnum, rel,
- ((op1 & 0xc7) == 0x05
- && op1 != (4 << 3)));
- memcpy(view - 3, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
- }
- else
- {
- Target_x86_64::Relocate::check_tls(relinfo, relnum, rel,
- (op1 & 0xf8) == 0x80 && (op1 & 7) != 4);
- if (static_cast<off_t>(rel.get_r_offset() + 9) < view_size
- && view[9] == 0x90)
- {
- // There is a trailing nop. Use the size byte subl.
- memcpy(view - 2, "\x65\xa1\0\0\0\0\x81\xe8\0\0\0", 12);
- roff = 6;
- }
- else
- {
- // Use the five byte subl.
- memcpy(view - 2, "\x65\xa1\0\0\0\0\x2d\0\0\0", 11);
- }
- }
-
- value = tls_segment->vaddr() + tls_segment->memsz() - value;
- Relocate_functions<64, false>::rel32(view + roff, value);
+ value = value - (tls_segment->vaddr() + tls_segment->memsz());
+ Relocate_functions<64, false>::rela32(view + 8, value, 0);
// The next reloc should be a PLT32 reloc against __tls_get_addr.
// We can skip it.