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llvm-project/lld/lib/ReaderWriter/MachO/ArchHandler_x86_64.cpp

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//===- lib/FileFormat/MachO/ArchHandler_x86_64.cpp ------------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "ArchHandler.h"
#include "Atoms.h"
#include "MachONormalizedFileBinaryUtils.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/Triple.h"
#include "llvm/Support/ErrorHandling.h"
using namespace llvm::MachO;
using namespace lld::mach_o::normalized;
namespace lld {
namespace mach_o {
class ArchHandler_x86_64 : public ArchHandler {
public:
ArchHandler_x86_64();
virtual ~ArchHandler_x86_64();
const Registry::KindStrings *kindStrings() override { return _sKindStrings; }
Reference::KindArch kindArch() override {
return Reference::KindArch::x86_64;
}
/// Used by GOTPass to locate GOT References
bool isGOTAccess(const Reference &ref, bool &canBypassGOT) override {
if (ref.kindNamespace() != Reference::KindNamespace::mach_o)
return false;
assert(ref.kindArch() == Reference::KindArch::x86_64);
switch (ref.kindValue()) {
case ripRel32GotLoad:
canBypassGOT = true;
return true;
case ripRel32Got:
canBypassGOT = false;
return true;
default:
return false;
}
}
/// Used by GOTPass to update GOT References
void updateReferenceToGOT(const Reference *ref, bool targetNowGOT) override {
assert(ref->kindNamespace() == Reference::KindNamespace::mach_o);
assert(ref->kindArch() == Reference::KindArch::x86_64);
const_cast<Reference *>(ref)
->setKindValue(targetNowGOT ? ripRel32 : ripRel32GotLoadNowLea);
}
const StubInfo &stubInfo() override { return _sStubInfo; }
bool isCallSite(const Reference &) override;
bool isPointer(const Reference &) override;
bool isPairedReloc(const normalized::Relocation &) override;
std::error_code getReferenceInfo(const normalized::Relocation &reloc,
const DefinedAtom *inAtom,
uint32_t offsetInAtom,
uint64_t fixupAddress, bool swap,
FindAtomBySectionAndAddress atomFromAddress,
FindAtomBySymbolIndex atomFromSymbolIndex,
Reference::KindValue *kind,
const lld::Atom **target,
Reference::Addend *addend) override;
std::error_code
getPairReferenceInfo(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2,
const DefinedAtom *inAtom,
uint32_t offsetInAtom,
uint64_t fixupAddress, bool swap,
FindAtomBySectionAndAddress atomFromAddress,
FindAtomBySymbolIndex atomFromSymbolIndex,
Reference::KindValue *kind,
const lld::Atom **target,
Reference::Addend *addend) override;
virtual bool needsLocalSymbolInRelocatableFile(const DefinedAtom *atom) {
return (atom->contentType() == DefinedAtom::typeCString);
}
void generateAtomContent(const DefinedAtom &atom, bool relocatable,
FindAddressForAtom findAddress,
uint8_t *atomContentBuffer) override;
void appendSectionRelocations(const DefinedAtom &atom,
uint64_t atomSectionOffset,
const Reference &ref,
FindSymbolIndexForAtom symbolIndexForAtom,
FindSectionIndexForAtom sectionIndexForAtom,
FindAddressForAtom addressForAtom,
normalized::Relocations &relocs) override;
private:
static const Registry::KindStrings _sKindStrings[];
static const StubInfo _sStubInfo;
enum : Reference::KindValue {
invalid, /// for error condition
// Kinds found in mach-o .o files:
branch32, /// ex: call _foo
ripRel32, /// ex: movq _foo(%rip), %rax
ripRel32Minus1, /// ex: movb $0x12, _foo(%rip)
ripRel32Minus2, /// ex: movw $0x1234, _foo(%rip)
ripRel32Minus4, /// ex: movl $0x12345678, _foo(%rip)
ripRel32Anon, /// ex: movq L1(%rip), %rax
ripRel32GotLoad, /// ex: movq _foo@GOTPCREL(%rip), %rax
ripRel32Got, /// ex: pushq _foo@GOTPCREL(%rip)
pointer64, /// ex: .quad _foo
pointer64Anon, /// ex: .quad L1
delta64, /// ex: .quad _foo - .
delta32, /// ex: .long _foo - .
delta64Anon, /// ex: .quad L1 - .
delta32Anon, /// ex: .long L1 - .
// Kinds introduced by Passes:
ripRel32GotLoadNowLea, /// Target of GOT load is in linkage unit so
/// "movq _foo@GOTPCREL(%rip), %rax" can be changed
/// to "leaq _foo(%rip), %rax
lazyPointer, /// Location contains a lazy pointer.
lazyImmediateLocation, /// Location contains immediate value used in stub.
};
Reference::KindValue kindFromReloc(const normalized::Relocation &reloc);
Reference::KindValue kindFromRelocPair(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2);
void applyFixupFinal(const Reference &ref, uint8_t *location,
uint64_t fixupAddress, uint64_t targetAddress,
uint64_t inAtomAddress);
void applyFixupRelocatable(const Reference &ref, uint8_t *location,
uint64_t fixupAddress,
uint64_t targetAddress,
uint64_t inAtomAddress);
const bool _swap;
};
ArchHandler_x86_64::ArchHandler_x86_64() :
_swap(!MachOLinkingContext::isHostEndian(MachOLinkingContext::arch_x86_64)) {}
ArchHandler_x86_64::~ArchHandler_x86_64() { }
const Registry::KindStrings ArchHandler_x86_64::_sKindStrings[] = {
LLD_KIND_STRING_ENTRY(invalid), LLD_KIND_STRING_ENTRY(branch32),
LLD_KIND_STRING_ENTRY(ripRel32), LLD_KIND_STRING_ENTRY(ripRel32Minus1),
LLD_KIND_STRING_ENTRY(ripRel32Minus2), LLD_KIND_STRING_ENTRY(ripRel32Minus4),
LLD_KIND_STRING_ENTRY(ripRel32Anon), LLD_KIND_STRING_ENTRY(ripRel32GotLoad),
LLD_KIND_STRING_ENTRY(ripRel32GotLoadNowLea),
LLD_KIND_STRING_ENTRY(ripRel32Got), LLD_KIND_STRING_ENTRY(lazyPointer),
LLD_KIND_STRING_ENTRY(lazyImmediateLocation),
LLD_KIND_STRING_ENTRY(pointer64), LLD_KIND_STRING_ENTRY(pointer64Anon),
LLD_KIND_STRING_ENTRY(delta32), LLD_KIND_STRING_ENTRY(delta64),
LLD_KIND_STRING_ENTRY(delta32Anon), LLD_KIND_STRING_ENTRY(delta64Anon),
LLD_KIND_STRING_END
};
const ArchHandler::StubInfo ArchHandler_x86_64::_sStubInfo = {
"dyld_stub_binder",
// Lazy pointer references
{ Reference::KindArch::x86_64, pointer64, 0, 0 },
{ Reference::KindArch::x86_64, lazyPointer, 0, 0 },
// GOT pointer to dyld_stub_binder
{ Reference::KindArch::x86_64, pointer64, 0, 0 },
// x86_64 code alignment 2^1
1,
// Stub size and code
6,
{ 0xff, 0x25, 0x00, 0x00, 0x00, 0x00 }, // jmp *lazyPointer
{ Reference::KindArch::x86_64, ripRel32, 2, 0 },
// Stub Helper size and code
10,
{ 0x68, 0x00, 0x00, 0x00, 0x00, // pushq $lazy-info-offset
0xE9, 0x00, 0x00, 0x00, 0x00 }, // jmp helperhelper
{ Reference::KindArch::x86_64, lazyImmediateLocation, 1, 0 },
{ Reference::KindArch::x86_64, branch32, 6, 0 },
// Stub Helper-Common size and code
16,
{ 0x4C, 0x8D, 0x1D, 0x00, 0x00, 0x00, 0x00, // leaq cache(%rip),%r11
0x41, 0x53, // push %r11
0xFF, 0x25, 0x00, 0x00, 0x00, 0x00, // jmp *binder(%rip)
0x90 }, // nop
{ Reference::KindArch::x86_64, ripRel32, 3, 0 },
{ Reference::KindArch::x86_64, ripRel32, 11, 0 }
};
bool ArchHandler_x86_64::isCallSite(const Reference &ref) {
if (ref.kindNamespace() != Reference::KindNamespace::mach_o)
return false;
assert(ref.kindArch() == Reference::KindArch::x86_64);
return (ref.kindValue() == branch32);
}
bool ArchHandler_x86_64::isPointer(const Reference &ref) {
if (ref.kindNamespace() != Reference::KindNamespace::mach_o)
return false;
assert(ref.kindArch() == Reference::KindArch::x86_64);
Reference::KindValue kind = ref.kindValue();
return (kind == pointer64 || kind == pointer64Anon);
}
bool ArchHandler_x86_64::isPairedReloc(const Relocation &reloc) {
return (reloc.type == X86_64_RELOC_SUBTRACTOR);
}
Reference::KindValue
ArchHandler_x86_64::kindFromReloc(const Relocation &reloc) {
switch(relocPattern(reloc)) {
case X86_64_RELOC_BRANCH | rPcRel | rExtern | rLength4:
return branch32;
case X86_64_RELOC_SIGNED | rPcRel | rExtern | rLength4:
return ripRel32;
case X86_64_RELOC_SIGNED | rPcRel | rLength4:
return ripRel32Anon;
case X86_64_RELOC_SIGNED_1 | rPcRel | rExtern | rLength4:
return ripRel32Minus1;
case X86_64_RELOC_SIGNED_2 | rPcRel | rExtern | rLength4:
return ripRel32Minus2;
case X86_64_RELOC_SIGNED_4 | rPcRel | rExtern | rLength4:
return ripRel32Minus4;
case X86_64_RELOC_GOT_LOAD | rPcRel | rExtern | rLength4:
return ripRel32GotLoad;
case X86_64_RELOC_GOT | rPcRel | rExtern | rLength4:
return ripRel32Got;
case X86_64_RELOC_UNSIGNED | rExtern | rLength8:
return pointer64;
case X86_64_RELOC_UNSIGNED | rLength8:
return pointer64Anon;
default:
return invalid;
}
}
std::error_code
ArchHandler_x86_64::getReferenceInfo(const Relocation &reloc,
const DefinedAtom *inAtom,
uint32_t offsetInAtom,
uint64_t fixupAddress, bool swap,
FindAtomBySectionAndAddress atomFromAddress,
FindAtomBySymbolIndex atomFromSymbolIndex,
Reference::KindValue *kind,
const lld::Atom **target,
Reference::Addend *addend) {
typedef std::error_code E;
*kind = kindFromReloc(reloc);
if (*kind == invalid)
return make_dynamic_error_code(Twine("unknown type"));
const uint8_t *fixupContent = &inAtom->rawContent()[offsetInAtom];
uint64_t targetAddress;
switch (*kind) {
case branch32:
case ripRel32:
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = readS32(swap, fixupContent);
return std::error_code();
case ripRel32Minus1:
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = readS32(swap, fixupContent) + 1;
return std::error_code();
case ripRel32Minus2:
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = readS32(swap, fixupContent) + 2;
return std::error_code();
case ripRel32Minus4:
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = readS32(swap, fixupContent) + 4;
return std::error_code();
case ripRel32Anon:
targetAddress = fixupAddress + 4 + readS32(swap, fixupContent);
return atomFromAddress(reloc.symbol, targetAddress, target, addend);
case ripRel32GotLoad:
case ripRel32Got:
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = 0;
return std::error_code();
case pointer64:
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = readS64(swap, fixupContent);
return std::error_code();
case pointer64Anon:
targetAddress = readS64(swap, fixupContent);
return atomFromAddress(reloc.symbol, targetAddress, target, addend);
default:
llvm_unreachable("bad reloc kind");
}
}
Reference::KindValue
ArchHandler_x86_64::kindFromRelocPair(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2) {
switch(relocPattern(reloc1) << 16 | relocPattern(reloc2)) {
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength8) << 16 |
X86_64_RELOC_UNSIGNED | rExtern | rLength8):
return delta64;
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength4) << 16 |
X86_64_RELOC_UNSIGNED | rExtern | rLength4):
return delta32;
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength8) << 16 |
X86_64_RELOC_UNSIGNED | rLength8):
return delta64Anon;
case ((X86_64_RELOC_SUBTRACTOR | rExtern | rLength4) << 16 |
X86_64_RELOC_UNSIGNED | rLength4):
return delta32Anon;
default:
llvm_unreachable("bad reloc pairs");
}
}
std::error_code
ArchHandler_x86_64::getPairReferenceInfo(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2,
const DefinedAtom *inAtom,
uint32_t offsetInAtom,
uint64_t fixupAddress, bool swap,
FindAtomBySectionAndAddress atomFromAddress,
FindAtomBySymbolIndex atomFromSymbolIndex,
Reference::KindValue *kind,
const lld::Atom **target,
Reference::Addend *addend) {
*kind = kindFromRelocPair(reloc1, reloc2);
if (*kind == invalid)
return make_dynamic_error_code(Twine("unknown pair"));
const uint8_t *fixupContent = &inAtom->rawContent()[offsetInAtom];
typedef std::error_code E;
uint64_t targetAddress;
const lld::Atom *fromTarget;
if (E ec = atomFromSymbolIndex(reloc1.symbol, &fromTarget))
return ec;
if (fromTarget != inAtom)
return make_dynamic_error_code(Twine("pointer diff not in base atom"));
switch (*kind) {
case delta64:
if (E ec = atomFromSymbolIndex(reloc2.symbol, target))
return ec;
*addend = readS64(swap, fixupContent) + offsetInAtom;
return std::error_code();
case delta32:
if (E ec = atomFromSymbolIndex(reloc2.symbol, target))
return ec;
*addend = readS32(swap, fixupContent) + offsetInAtom;
return std::error_code();
case delta64Anon:
targetAddress = offsetInAtom + readS64(swap, fixupContent);
return atomFromAddress(reloc2.symbol, targetAddress, target, addend);
case delta32Anon:
targetAddress = offsetInAtom + readS32(swap, fixupContent);
return atomFromAddress(reloc2.symbol, targetAddress, target, addend);
default:
llvm_unreachable("bad reloc pair kind");
}
}
void ArchHandler_x86_64::generateAtomContent(const DefinedAtom &atom,
bool relocatable,
FindAddressForAtom findAddress,
uint8_t *atomContentBuffer) {
// Copy raw bytes.
memcpy(atomContentBuffer, atom.rawContent().data(), atom.size());
// Apply fix-ups.
for (const Reference *ref : atom) {
uint32_t offset = ref->offsetInAtom();
const Atom *target = ref->target();
uint64_t targetAddress = 0;
if (isa<DefinedAtom>(target))
targetAddress = findAddress(*target);
uint64_t atomAddress = findAddress(atom);
uint64_t fixupAddress = atomAddress + offset;
if (relocatable) {
applyFixupRelocatable(*ref, &atomContentBuffer[offset],
fixupAddress, targetAddress,
atomAddress);
} else {
applyFixupFinal(*ref, &atomContentBuffer[offset],
fixupAddress, targetAddress,
atomAddress);
}
}
}
void ArchHandler_x86_64::applyFixupFinal(const Reference &ref,
uint8_t *location,
uint64_t fixupAddress,
uint64_t targetAddress,
uint64_t inAtomAddress) {
if (ref.kindNamespace() != Reference::KindNamespace::mach_o)
return;
assert(ref.kindArch() == Reference::KindArch::x86_64);
int32_t *loc32 = reinterpret_cast<int32_t *>(location);
uint64_t *loc64 = reinterpret_cast<uint64_t *>(location);
switch (ref.kindValue()) {
case branch32:
case ripRel32:
case ripRel32Got:
case ripRel32GotLoad:
write32(*loc32, _swap, (targetAddress - (fixupAddress + 4)) + ref.addend());
break;
case pointer64:
case pointer64Anon:
write64(*loc64, _swap, targetAddress + ref.addend());
break;
case ripRel32Minus1:
write32(*loc32, _swap, (targetAddress - (fixupAddress + 5)) + ref.addend());
break;
case ripRel32Minus2:
write32(*loc32, _swap, (targetAddress - (fixupAddress + 6)) + ref.addend());
break;
case ripRel32Minus4:
write32(*loc32, _swap, (targetAddress - (fixupAddress + 8)) + ref.addend());
break;
case delta32:
case delta32Anon:
write32(*loc32, _swap, (targetAddress - fixupAddress) + ref.addend());
break;
case delta64:
case delta64Anon:
write64(*loc64, _swap, (targetAddress - fixupAddress) + ref.addend());
break;
case ripRel32GotLoadNowLea:
// Change MOVQ to LEA
assert(location[-2] == 0x8B);
location[-2] = 0x8D;
write32(*loc32, _swap, (targetAddress - (fixupAddress + 4)) + ref.addend());
break;
case lazyPointer:
case lazyImmediateLocation:
// do nothing
break;
default:
llvm_unreachable("invalid x86_64 Reference Kind");
break;
}
}
void ArchHandler_x86_64::applyFixupRelocatable(const Reference &ref,
uint8_t *location,
uint64_t fixupAddress,
uint64_t targetAddress,
uint64_t inAtomAddress) {
int32_t *loc32 = reinterpret_cast<int32_t *>(location);
uint64_t *loc64 = reinterpret_cast<uint64_t *>(location);
switch (ref.kindValue()) {
case branch32:
case ripRel32:
case ripRel32Got:
case ripRel32GotLoad:
write32(*loc32, _swap, ref.addend());
break;
case pointer64:
write64(*loc64, _swap, ref.addend());
break;
case pointer64Anon:
write64(*loc64, _swap, targetAddress + ref.addend());
break;
case ripRel32Minus1:
write32(*loc32, _swap, ref.addend() - 1);
break;
case ripRel32Minus2:
write32(*loc32, _swap, ref.addend() - 2);
break;
case ripRel32Minus4:
write32(*loc32, _swap, ref.addend() - 4);
break;
case delta32:
write32(*loc32, _swap, ref.addend() + inAtomAddress - fixupAddress);
break;
case delta32Anon:
write32(*loc32, _swap, (targetAddress - fixupAddress) + ref.addend());
break;
case delta64:
write64(*loc64, _swap, ref.addend() + inAtomAddress - fixupAddress);
break;
case delta64Anon:
write64(*loc64, _swap, (targetAddress - fixupAddress) + ref.addend());
break;
case ripRel32GotLoadNowLea:
llvm_unreachable("ripRel32GotLoadNowLea implies GOT pass was run");
break;
case lazyPointer:
case lazyImmediateLocation:
llvm_unreachable("lazy reference kind implies Stubs pass was run");
break;
default:
llvm_unreachable("unknown x86_64 Reference Kind");
break;
}
}
void ArchHandler_x86_64::appendSectionRelocations(
const DefinedAtom &atom,
uint64_t atomSectionOffset,
const Reference &ref,
FindSymbolIndexForAtom symbolIndexForAtom,
FindSectionIndexForAtom sectionIndexForAtom,
FindAddressForAtom addressForAtom,
normalized::Relocations &relocs) {
if (ref.kindNamespace() != Reference::KindNamespace::mach_o)
return;
assert(ref.kindArch() == Reference::KindArch::x86_64);
uint32_t sectionOffset = atomSectionOffset + ref.offsetInAtom();
switch (ref.kindValue()) {
case branch32:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_BRANCH | rPcRel | rExtern | rLength4);
break;
case ripRel32:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_SIGNED | rPcRel | rExtern | rLength4 );
break;
case ripRel32Got:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_GOT | rPcRel | rExtern | rLength4 );
break;
case ripRel32GotLoad:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_GOT_LOAD | rPcRel | rExtern | rLength4 );
break;
case pointer64:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_UNSIGNED | rExtern | rLength8);
break;
case pointer64Anon:
appendReloc(relocs, sectionOffset, sectionIndexForAtom(*ref.target()), 0,
X86_64_RELOC_UNSIGNED | rLength8);
break;
case ripRel32Minus1:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_SIGNED_1 | rPcRel | rExtern | rLength4 );
break;
case ripRel32Minus2:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_SIGNED_2 | rPcRel | rExtern | rLength4 );
break;
case ripRel32Minus4:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_SIGNED_4 | rPcRel | rExtern | rLength4 );
break;
case delta32:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(atom), 0,
X86_64_RELOC_SUBTRACTOR | rExtern | rLength4 );
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_UNSIGNED | rExtern | rLength4 );
break;
case delta32Anon:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(atom), 0,
X86_64_RELOC_SUBTRACTOR | rExtern | rLength4 );
appendReloc(relocs, sectionOffset, sectionIndexForAtom(*ref.target()), 0,
X86_64_RELOC_UNSIGNED | rLength4 );
break;
case delta64:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(atom), 0,
X86_64_RELOC_SUBTRACTOR | rExtern | rLength8 );
appendReloc(relocs, sectionOffset, symbolIndexForAtom(*ref.target()), 0,
X86_64_RELOC_UNSIGNED | rExtern | rLength8 );
break;
case delta64Anon:
appendReloc(relocs, sectionOffset, symbolIndexForAtom(atom), 0,
X86_64_RELOC_SUBTRACTOR | rExtern | rLength8 );
appendReloc(relocs, sectionOffset, sectionIndexForAtom(*ref.target()), 0,
X86_64_RELOC_UNSIGNED | rLength8 );
break;
case ripRel32GotLoadNowLea:
llvm_unreachable("ripRel32GotLoadNowLea implies GOT pass was run");
break;
case lazyPointer:
case lazyImmediateLocation:
llvm_unreachable("lazy reference kind implies Stubs pass was run");
break;
default:
llvm_unreachable("unknown x86_64 Reference Kind");
break;
}
}
std::unique_ptr<mach_o::ArchHandler> ArchHandler::create_x86_64() {
return std::unique_ptr<mach_o::ArchHandler>(new ArchHandler_x86_64());
}
} // namespace mach_o
} // namespace lld
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