ErrorOr<void> X86TargetRelocationHandler::applyRelocation(
ELFWriter &writer, llvm::FileOutputBuffer &buf, const lld::AtomLayout &atom,
const Reference &ref) const {
uint8_t *atomContent = buf.getBufferStart() + atom._fileOffset;
uint8_t *location = atomContent + ref.offsetInAtom();
uint64_t targetVAddress = writer.addressOfAtom(ref.target());
uint64_t relocVAddress = atom._virtualAddr + ref.offsetInAtom();
switch (ref.kind()) {
case R_386_32:
reloc32(location, relocVAddress, targetVAddress, ref.addend());
break;
case R_386_PC32:
relocPC32(location, relocVAddress, targetVAddress, ref.addend());
break;
case lld::Reference::kindLayoutAfter:
case lld::Reference::kindLayoutBefore:
case lld::Reference::kindInGroup:
break;
default : {
std::string str;
llvm::raw_string_ostream s(str);
auto name = _targetInfo.stringFromRelocKind(ref.kind());
s << "Unhandled relocation: "
<< (name ? *name : "<unknown>" ) << " (" << ref.kind() << ")";
s.flush();
llvm_unreachable(str.c_str());
}
}
return error_code::success();
}
std::error_code X86TargetRelocationHandler::applyRelocation(
ELFWriter &writer, llvm::FileOutputBuffer &buf, const AtomLayout &atom,
const Reference &ref) const {
uint8_t *atomContent = buf.getBufferStart() + atom._fileOffset;
uint8_t *loc = atomContent + ref.offsetInAtom();
uint64_t target = writer.addressOfAtom(ref.target());
uint64_t reloc = atom._virtualAddr + ref.offsetInAtom();
if (ref.kindNamespace() != Reference::KindNamespace::ELF)
return std::error_code();
assert(ref.kindArch() == Reference::KindArch::x86);
switch (ref.kindValue()) {
case R_386_32:
reloc32(loc, reloc, target, ref.addend());
break;
case R_386_PC32:
relocPC32(loc, reloc, target, ref.addend());
break;
default:
return make_unhandled_reloc_error();
}
return std::error_code();
}
std::error_code X86_64TargetRelocationHandler::applyRelocation(
ELFWriter &writer, llvm::FileOutputBuffer &buf, const AtomLayout &atom,
const Reference &ref) const {
uint8_t *atomContent = buf.getBufferStart() + atom._fileOffset;
uint8_t *loc = atomContent + ref.offsetInAtom();
uint64_t target = writer.addressOfAtom(ref.target());
uint64_t reloc = atom._virtualAddr + ref.offsetInAtom();
if (ref.kindNamespace() != Reference::KindNamespace::ELF)
return std::error_code();
assert(ref.kindArch() == Reference::KindArch::x86_64);
switch (ref.kindValue()) {
case R_X86_64_NONE:
break;
case R_X86_64_64:
reloc64(loc, reloc, target, ref.addend());
break;
case R_X86_64_PC32:
case R_X86_64_GOTPCREL:
relocPC32(loc, reloc, target, ref.addend());
break;
case R_X86_64_32:
reloc32(loc, reloc, target, ref.addend());
break;
case R_X86_64_32S:
reloc32S(loc, reloc, target, ref.addend());
break;
case R_X86_64_16:
reloc16(loc, reloc, target, ref.addend());
break;
case R_X86_64_PC16:
relocPC16(loc, reloc, target, ref.addend());
break;
case R_X86_64_TPOFF64:
case R_X86_64_DTPOFF32:
case R_X86_64_TPOFF32: {
_tlsSize = _layout.getTLSSize();
if (ref.kindValue() == R_X86_64_TPOFF32 ||
ref.kindValue() == R_X86_64_DTPOFF32) {
write32le(loc, target - _tlsSize);
} else {
write64le(loc, target - _tlsSize);
}
break;
}
case R_X86_64_TLSGD: {
relocPC32(loc, reloc, target, ref.addend());
break;
}
case R_X86_64_TLSLD: {
// Rewrite to move %fs:0 into %rax. Technically we should verify that the
// next relocation is a PC32 to __tls_get_addr...
static uint8_t instr[] = { 0x66, 0x66, 0x66, 0x64, 0x48, 0x8b, 0x04, 0x25,
0x00, 0x00, 0x00, 0x00 };
std::memcpy(loc - 3, instr, sizeof(instr));
break;
}
case R_X86_64_PC64:
relocPC64(loc, reloc, target, ref.addend());
break;
case LLD_R_X86_64_GOTRELINDEX: {
const DefinedAtom *target = cast<const DefinedAtom>(ref.target());
for (const Reference *r : *target) {
if (r->kindValue() == R_X86_64_JUMP_SLOT) {
uint32_t index;
if (!_layout.getPLTRelocationTable()->getRelocationIndex(*r, index))
llvm_unreachable("Relocation doesn't exist");
reloc32(loc, 0, index, 0);
break;
}
}
break;
}
// Runtime only relocations. Ignore here.
case R_X86_64_RELATIVE:
case R_X86_64_IRELATIVE:
case R_X86_64_JUMP_SLOT:
case R_X86_64_GLOB_DAT:
case R_X86_64_DTPMOD64:
case R_X86_64_DTPOFF64:
break;
default:
return make_unhandled_reloc_error();
}
return std::error_code();
}