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llvm-project/lld/lib/ReaderWriter/MachO/ReferenceKinds.cpp
Nick Kledzik 4576c115ac [mach-o] Add parsing of arm/thumb relocations 
This converts the very complicated mach-o arm
relocations into the simple Reference Kinds in lld.

The next patch will use the internal Reference kinds
to fix up arm/thumb code.

llvm-svn: 212306
2014-07-04 00:11:09 +00:00

1101 lines
37 KiB
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//===- lib/FileFormat/MachO/ReferenceKinds.cpp ----------------------===//
//
// The LLVM Linker
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#include "ReferenceKinds.h"
#include "MachONormalizedFileBinaryUtils.h"
#include "Atoms.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 {
//===----------------------------------------------------------------------===//
// KindHandler
//===----------------------------------------------------------------------===//
KindHandler::KindHandler() {
}
KindHandler::~KindHandler() {
}
std::unique_ptr<mach_o::KindHandler>
KindHandler::create(MachOLinkingContext::Arch arch) {
switch (arch) {
case MachOLinkingContext::arch_x86_64:
return std::unique_ptr<mach_o::KindHandler>(new KindHandler_x86_64());
case MachOLinkingContext::arch_x86:
return std::unique_ptr<mach_o::KindHandler>(new KindHandler_x86());
case MachOLinkingContext::arch_armv6:
case MachOLinkingContext::arch_armv7:
case MachOLinkingContext::arch_armv7s:
return std::unique_ptr<mach_o::KindHandler>(new KindHandler_arm());
default:
llvm_unreachable("Unknown arch");
}
}
KindHandler::RelocPattern KindHandler::relocPattern(const Relocation &reloc) {
assert((reloc.type & 0xFFF0) == 0);
uint16_t result = reloc.type;
if (reloc.scattered)
result |= rScattered;
if (reloc.pcRel)
result |= rPcRel;
if (reloc.isExtern)
result |= rExtern;
switch(reloc.length) {
case 0:
break;
case 1:
result |= rLength2;
break;
case 2:
result |= rLength4;
break;
case 3:
result |= rLength8;
break;
default:
llvm_unreachable("bad r_length");
}
return result;
}
int16_t KindHandler::readS16(bool swap, const uint8_t *addr) {
return read16(swap, *reinterpret_cast<const uint16_t*>(addr));
}
int32_t KindHandler::readS32(bool swap, const uint8_t *addr) {
return read32(swap, *reinterpret_cast<const uint32_t*>(addr));
}
uint32_t KindHandler::readU32(bool swap, const uint8_t *addr) {
return read32(swap, *reinterpret_cast<const uint32_t*>(addr));
}
int64_t KindHandler::readS64(bool swap, const uint8_t *addr) {
return read64(swap, *reinterpret_cast<const uint64_t*>(addr));
}
//===----------------------------------------------------------------------===//
// KindHandler_x86_64
//===----------------------------------------------------------------------===//
KindHandler_x86_64::~KindHandler_x86_64() {
}
const Registry::KindStrings KindHandler_x86_64::kindStrings[] = {
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
};
bool KindHandler_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 KindHandler_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 KindHandler_x86_64::isLazyImmediate(const Reference &ref) {
if (ref.kindNamespace() != Reference::KindNamespace::mach_o)
return false;
assert(ref.kindArch() == Reference::KindArch::x86_64);
return (ref.kindValue() == lazyImmediateLocation);
}
bool KindHandler_x86_64::isLazyTarget(const Reference &ref) {
if (ref.kindNamespace() != Reference::KindNamespace::mach_o)
return false;
assert(ref.kindArch() == Reference::KindArch::x86_64);
return (ref.kindValue() == lazyPointer);
}
bool KindHandler_x86_64::isPairedReloc(const Relocation &reloc) {
return (reloc.type == X86_64_RELOC_SUBTRACTOR);
}
Reference::KindValue
KindHandler_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
KindHandler_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
KindHandler_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
KindHandler_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 KindHandler_x86_64::applyFixup(Reference::KindNamespace ns,
Reference::KindArch arch,
Reference::KindValue kindValue,
uint64_t addend, uint8_t *location,
uint64_t fixupAddress,
uint64_t targetAddress,
uint64_t inAtomAddress) {
if (ns != Reference::KindNamespace::mach_o)
return;
assert(arch == Reference::KindArch::x86_64);
int32_t *loc32 = reinterpret_cast<int32_t*>(location);
uint64_t* loc64 = reinterpret_cast<uint64_t*>(location);
switch (kindValue) {
case branch32:
case ripRel32:
case ripRel32Got:
case ripRel32GotLoad:
*loc32 = (targetAddress - (fixupAddress+4)) + addend;
break;
case pointer64:
case pointer64Anon:
*loc64 = targetAddress + addend;
break;
case ripRel32Minus1:
*loc32 = (targetAddress - (fixupAddress+5)) + addend;
break;
case ripRel32Minus2:
*loc32 = (targetAddress - (fixupAddress+6)) + addend;
break;
case ripRel32Minus4:
*loc32 = (targetAddress - (fixupAddress+8)) + addend;
break;
case delta32:
case delta32Anon:
*loc32 = (targetAddress - fixupAddress) + addend;
break;
case delta64:
case delta64Anon:
*loc64 = (targetAddress - fixupAddress) + addend;
break;
case ripRel32GotLoadNowLea:
// Change MOVQ to LEA
assert(location[-2] == 0x8B);
location[-2] = 0x8D;
*loc32 = (targetAddress - (fixupAddress+4)) + addend;
break;
case lazyPointer:
case lazyImmediateLocation:
// do nothing
break;
default:
llvm_unreachable("invalid x86_64 Reference Kind");
break;
}
}
//===----------------------------------------------------------------------===//
// KindHandler_x86
//===----------------------------------------------------------------------===//
KindHandler_x86::~KindHandler_x86() {
}
const Registry::KindStrings KindHandler_x86::kindStrings[] = {
LLD_KIND_STRING_ENTRY(invalid),
LLD_KIND_STRING_ENTRY(branch32),
LLD_KIND_STRING_ENTRY(branch16),
LLD_KIND_STRING_ENTRY(abs32),
LLD_KIND_STRING_ENTRY(funcRel32),
LLD_KIND_STRING_ENTRY(pointer32),
LLD_KIND_STRING_ENTRY(delta32),
LLD_KIND_STRING_ENTRY(lazyPointer),
LLD_KIND_STRING_ENTRY(lazyImmediateLocation),
LLD_KIND_STRING_END
};
bool KindHandler_x86::isCallSite(const Reference &ref) {
return (ref.kindValue() == branch32);
}
bool KindHandler_x86::isPointer(const Reference &ref) {
return (ref.kindValue() == pointer32);
}
bool KindHandler_x86::isLazyImmediate(const Reference &ref) {
return (ref.kindValue() == lazyImmediateLocation);
}
bool KindHandler_x86::isLazyTarget(const Reference &ref) {
return (ref.kindValue() == lazyPointer);
}
bool KindHandler_x86::isPairedReloc(const Relocation &reloc) {
if (!reloc.scattered)
return false;
return (reloc.type == GENERIC_RELOC_LOCAL_SECTDIFF) ||
(reloc.type == GENERIC_RELOC_SECTDIFF);
}
std::error_code
KindHandler_x86::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;
DefinedAtom::ContentPermissions perms;
const uint8_t *fixupContent = &inAtom->rawContent()[offsetInAtom];
uint64_t targetAddress;
switch (relocPattern(reloc)) {
case GENERIC_RELOC_VANILLA | rPcRel | rExtern | rLength4:
// ex: call _foo (and _foo undefined)
*kind = branch32;
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = fixupAddress + 4 + readS32(swap, fixupContent);
break;
case GENERIC_RELOC_VANILLA | rPcRel | rLength4:
// ex: call _foo (and _foo defined)
*kind = branch32;
targetAddress = fixupAddress + 4 + readS32(swap, fixupContent);
return atomFromAddress(reloc.symbol, targetAddress, target, addend);
break;
case GENERIC_RELOC_VANILLA | rPcRel | rExtern | rLength2:
// ex: callw _foo (and _foo undefined)
*kind = branch16;
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = fixupAddress + 2 + readS16(swap, fixupContent);
break;
case GENERIC_RELOC_VANILLA | rPcRel | rLength2:
// ex: callw _foo (and _foo defined)
*kind = branch16;
targetAddress = fixupAddress + 2 + readS16(swap, fixupContent);
return atomFromAddress(reloc.symbol, targetAddress, target, addend);
break;
case GENERIC_RELOC_VANILLA | rExtern | rLength4:
// ex: movl _foo, %eax (and _foo undefined)
// ex: .long _foo (and _foo undefined)
perms = inAtom->permissions();
*kind = ((perms & DefinedAtom::permR_X) == DefinedAtom::permR_X)
? abs32 : pointer32;
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = readU32(swap, fixupContent);
break;
case GENERIC_RELOC_VANILLA | rLength4:
// ex: movl _foo, %eax (and _foo defined)
// ex: .long _foo (and _foo defined)
perms = inAtom->permissions();
*kind = ((perms & DefinedAtom::permR_X) == DefinedAtom::permR_X)
? abs32 : pointer32;
targetAddress = readU32(swap, fixupContent);
return atomFromAddress(reloc.symbol, targetAddress, target, addend);
break;
default:
return make_dynamic_error_code(Twine("unsupported i386 relocation type"));
}
return std::error_code();
}
std::error_code
KindHandler_x86::getPairReferenceInfo(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2,
const DefinedAtom *inAtom,
uint32_t offsetInAtom,
uint64_t fixupAddress, bool swap,
FindAtomBySectionAndAddress atomFromAddr,
FindAtomBySymbolIndex atomFromSymbolIndex,
Reference::KindValue *kind,
const lld::Atom **target,
Reference::Addend *addend) {
const uint8_t *fixupContent = &inAtom->rawContent()[offsetInAtom];
std::error_code ec;
DefinedAtom::ContentPermissions perms = inAtom->permissions();
uint32_t fromAddress;
uint32_t toAddress;
uint32_t value;
const lld::Atom *fromTarget;
Reference::Addend offsetInTo;
Reference::Addend offsetInFrom;
switch(relocPattern(reloc1) << 16 | relocPattern(reloc2)) {
case ((GENERIC_RELOC_SECTDIFF | rScattered | rLength4) << 16 |
GENERIC_RELOC_PAIR | rScattered | rLength4):
case ((GENERIC_RELOC_LOCAL_SECTDIFF | rScattered | rLength4) << 16 |
GENERIC_RELOC_PAIR | rScattered | rLength4):
toAddress = reloc1.value;
fromAddress = reloc2.value;
value = readS32(swap, fixupContent);
ec = atomFromAddr(0, toAddress, target, &offsetInTo);
if (ec)
return ec;
ec = atomFromAddr(0, fromAddress, &fromTarget, &offsetInFrom);
if (ec)
return ec;
if (fromTarget != inAtom)
return make_dynamic_error_code(Twine("SECTDIFF relocation where "
"subtrahend label is not in atom"));
*kind = ((perms & DefinedAtom::permR_X) == DefinedAtom::permR_X)
? funcRel32 : delta32;
if (*kind == funcRel32) {
// SECTDIFF relocations are used in i386 codegen where the function
// prolog does a CALL to the next instruction which POPs the return
// address into EBX which becomes the pic-base register. The POP
// instruction is label the used for the subtrahend in expressions.
// The funcRel32 kind represents the 32-bit delta to some symbol from
// the start of the function (atom) containing the funcRel32.
uint32_t ta = fromAddress + value - toAddress;
*addend = ta - offsetInFrom;
} else {
*addend = fromAddress + value - toAddress;
}
return std::error_code();
break;
default:
return make_dynamic_error_code(Twine("unsupported i386 relocation type"));
}
}
void KindHandler_x86::applyFixup(Reference::KindNamespace ns,
Reference::KindArch arch,
Reference::KindValue kindValue,
uint64_t addend, uint8_t *location,
uint64_t fixupAddress,
uint64_t targetAddress,
uint64_t inAtomAddress) {
if (ns != Reference::KindNamespace::mach_o)
return;
assert(arch == Reference::KindArch::x86);
int32_t *loc32 = reinterpret_cast<int32_t*>(location);
int16_t *loc16 = reinterpret_cast<int16_t*>(location);
// FIXME: these writes may need a swap.
switch (kindValue) {
case branch32:
*loc32 = (targetAddress - (fixupAddress+4)) + addend;
break;
case branch16:
*loc16 = (targetAddress - (fixupAddress+4)) + addend;
break;
case pointer32:
case abs32:
*loc32 = targetAddress + addend;
break;
case funcRel32:
*loc32 = targetAddress - inAtomAddress + addend; // FIXME
break;
case delta32:
*loc32 = targetAddress - fixupAddress + addend;
break;
case lazyPointer:
case lazyImmediateLocation:
// do nothing
break;
default:
llvm_unreachable("invalid x86 Reference Kind");
break;
}
}
//===----------------------------------------------------------------------===//
// KindHandler_arm
//===----------------------------------------------------------------------===//
KindHandler_arm::~KindHandler_arm() {
}
const Registry::KindStrings KindHandler_arm::kindStrings[] = {
LLD_KIND_STRING_ENTRY(thumb_b22),
LLD_KIND_STRING_ENTRY(thumb_movw),
LLD_KIND_STRING_ENTRY(thumb_movt),
LLD_KIND_STRING_ENTRY(thumb_movw_funcRel),
LLD_KIND_STRING_ENTRY(thumb_movt_funcRel),
LLD_KIND_STRING_ENTRY(arm_b24),
LLD_KIND_STRING_ENTRY(arm_movw),
LLD_KIND_STRING_ENTRY(arm_movt),
LLD_KIND_STRING_ENTRY(arm_movw_funcRel),
LLD_KIND_STRING_ENTRY(arm_movt_funcRel),
LLD_KIND_STRING_ENTRY(pointer32),
LLD_KIND_STRING_ENTRY(delta32),
LLD_KIND_STRING_ENTRY(lazyPointer),
LLD_KIND_STRING_ENTRY(lazyImmediateLocation),
LLD_KIND_STRING_END
};
bool KindHandler_arm::isCallSite(const Reference &ref) {
return (ref.kindValue() == thumb_b22) ||
(ref.kindValue() == arm_b24);
}
bool KindHandler_arm::isPointer(const Reference &ref) {
return (ref.kindValue() == pointer32);
}
bool KindHandler_arm::isLazyImmediate(const Reference &ref) {
return (ref.kindValue() == lazyImmediateLocation);
}
bool KindHandler_arm::isLazyTarget(const Reference &ref) {
return (ref.kindValue() == lazyPointer);
}
bool KindHandler_arm::isPairedReloc(const Relocation &reloc) {
switch (reloc.type) {
case ARM_RELOC_SECTDIFF:
case ARM_RELOC_LOCAL_SECTDIFF:
case ARM_RELOC_HALF_SECTDIFF:
case ARM_RELOC_HALF:
return true;
default:
return false;
}
}
int32_t KindHandler_arm::getDisplacementFromThumbBranch(uint32_t instruction) {
uint32_t s = (instruction >> 10) & 0x1;
uint32_t j1 = (instruction >> 29) & 0x1;
uint32_t j2 = (instruction >> 27) & 0x1;
uint32_t imm10 = instruction & 0x3FF;
uint32_t imm11 = (instruction >> 16) & 0x7FF;
uint32_t i1 = (j1 == s);
uint32_t i2 = (j2 == s);
uint32_t dis = (s << 24) | (i1 << 23) | (i2 << 22)
| (imm10 << 12) | (imm11 << 1);
int32_t sdis = dis;
if (s)
return (sdis | 0xFE000000);
else
return sdis;
}
int32_t KindHandler_arm::getDisplacementFromArmBranch(uint32_t instruction) {
// Sign-extend imm24
int32_t displacement = (instruction & 0x00FFFFFF) << 2;
if ( (displacement & 0x02000000) != 0 )
displacement |= 0xFC000000;
// If this is BLX and H bit set, add 2.
if ((instruction & 0xFF000000) == 0xFB000000)
displacement += 2;
return displacement;
}
uint16_t KindHandler_arm::getWordFromThumbMov(uint32_t instruction) {
uint32_t i = ((instruction & 0x00000400) >> 10);
uint32_t imm4 = (instruction & 0x0000000F);
uint32_t imm3 = ((instruction & 0x70000000) >> 28);
uint32_t imm8 = ((instruction & 0x00FF0000) >> 16);
return (imm4 << 12) | (i << 11) | (imm3 << 8) | imm8;
}
uint16_t KindHandler_arm::getWordFromArmMov(uint32_t instruction) {
uint32_t imm4 = ((instruction & 0x000F0000) >> 16);
uint32_t imm12 = (instruction & 0x00000FFF);
return (imm4 << 12) | imm12;
}
uint32_t KindHandler_arm::clearThumbBit(uint32_t value, const Atom* target) {
// The assembler often adds one to the address of a thumb function.
// We need to undo that so it does not look like an addend.
if (value & 1) {
if (isa<DefinedAtom>(target)) {
const MachODefinedAtom *machoTarget = reinterpret_cast<
const MachODefinedAtom*>(target);
if (machoTarget->isThumb())
value &= -2; // mask off thumb-bit
}
}
return value;
}
std::error_code
KindHandler_arm::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;
const uint8_t *fixupContent = &inAtom->rawContent()[offsetInAtom];
uint64_t targetAddress;
uint32_t instruction = readU32(swap, fixupContent);
int32_t displacement;
switch (relocPattern(reloc)) {
case ARM_THUMB_RELOC_BR22 | rPcRel | rExtern | rLength4:
// ex: bl _foo (and _foo is undefined)
*kind = thumb_b22;
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
// Instruction contains branch to addend.
displacement = getDisplacementFromThumbBranch(instruction);
*addend = fixupAddress + 4 + displacement;
return std::error_code();
case ARM_THUMB_RELOC_BR22 | rPcRel | rLength4:
// ex: bl _foo (and _foo is defined)
*kind = thumb_b22;
displacement = getDisplacementFromThumbBranch(instruction);
targetAddress = fixupAddress + 4 + displacement;
return atomFromAddress(reloc.symbol, targetAddress, target, addend);
case ARM_THUMB_RELOC_BR22 | rScattered | rPcRel | rLength4:
// ex: bl _foo+4 (and _foo is defined)
*kind = thumb_b22;
displacement = getDisplacementFromThumbBranch(instruction);
targetAddress = fixupAddress + 4 + displacement;
if (E ec = atomFromAddress(0, reloc.value, target, addend))
return ec;
// reloc.value is target atom's address. Instruction contains branch
// to atom+addend.
*addend += (targetAddress - reloc.value);
return std::error_code();
case ARM_RELOC_BR24 | rPcRel | rExtern | rLength4:
// ex: bl _foo (and _foo is undefined)
*kind = arm_b24;
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
// Instruction contains branch to addend.
displacement = getDisplacementFromArmBranch(instruction);
*addend = fixupAddress + 8 + displacement;
return std::error_code();
case ARM_RELOC_BR24 | rPcRel | rLength4:
// ex: bl _foo (and _foo is defined)
*kind = arm_b24;
displacement = getDisplacementFromArmBranch(instruction);
targetAddress = fixupAddress + 8 + displacement;
return atomFromAddress(reloc.symbol, targetAddress, target, addend);
case ARM_RELOC_BR24 | rScattered | rPcRel | rLength4:
// ex: bl _foo+4 (and _foo is defined)
*kind = arm_b24;
displacement = getDisplacementFromArmBranch(instruction);
targetAddress = fixupAddress + 8 + displacement;
if (E ec = atomFromAddress(0, reloc.value, target, addend))
return ec;
// reloc.value is target atom's address. Instruction contains branch
// to atom+addend.
*addend += (targetAddress - reloc.value);
return std::error_code();
case ARM_RELOC_VANILLA | rExtern | rLength4:
// ex: .long _foo (and _foo is undefined)
*kind = pointer32;
if (E ec = atomFromSymbolIndex(reloc.symbol, target))
return ec;
*addend = instruction;
return std::error_code();
case ARM_RELOC_VANILLA | rLength4:
// ex: .long _foo (and _foo is defined)
*kind = pointer32;
if (E ec = atomFromAddress(reloc.symbol, instruction, target, addend))
return ec;
*addend = clearThumbBit((uint32_t)*addend, *target);
return std::error_code();
case ARM_RELOC_VANILLA | rScattered | rLength4:
// ex: .long _foo+a (and _foo is defined)
*kind = pointer32;
if (E ec = atomFromAddress(0, reloc.value, target, addend))
return ec;
*addend += (clearThumbBit(instruction, *target) - reloc.value);
return std::error_code();
default:
return make_dynamic_error_code(Twine("unsupported arm relocation type"));
}
return std::error_code();
}
std::error_code
KindHandler_arm::getPairReferenceInfo(const normalized::Relocation &reloc1,
const normalized::Relocation &reloc2,
const DefinedAtom *inAtom,
uint32_t offsetInAtom,
uint64_t fixupAddress, bool swap,
FindAtomBySectionAndAddress atomFromAddr,
FindAtomBySymbolIndex atomFromSymbolIndex,
Reference::KindValue *kind,
const lld::Atom **target,
Reference::Addend *addend) {
bool pointerDiff = false;
bool funcRel;
bool top;
bool thumbReloc;
switch(relocPattern(reloc1) << 16 | relocPattern(reloc2)) {
case ((ARM_RELOC_HALF_SECTDIFF | rScattered | rLength4) << 16 |
ARM_RELOC_PAIR | rScattered | rLength4):
// ex: movw r1, :lower16:(_x-L1) [thumb mode]
*kind = thumb_movw_funcRel;
funcRel = true;
top = false;
thumbReloc = true;
break;
case ((ARM_RELOC_HALF_SECTDIFF | rScattered | rLength8) << 16 |
ARM_RELOC_PAIR | rScattered | rLength8):
// ex: movt r1, :upper16:(_x-L1) [thumb mode]
*kind = thumb_movt_funcRel;
funcRel = true;
top = true;
thumbReloc = true;
break;
case ((ARM_RELOC_HALF_SECTDIFF | rScattered | rLength1) << 16 |
ARM_RELOC_PAIR | rScattered | rLength1):
// ex: movw r1, :lower16:(_x-L1) [arm mode]
*kind = arm_movw_funcRel;
funcRel = true;
top = false;
thumbReloc = false;
break;
case ((ARM_RELOC_HALF_SECTDIFF | rScattered | rLength2) << 16 |
ARM_RELOC_PAIR | rScattered | rLength2):
// ex: movt r1, :upper16:(_x-L1) [arm mode]
*kind = arm_movt_funcRel;
funcRel = true;
top = true;
thumbReloc = false;
break;
case ((ARM_RELOC_HALF | rLength4) << 16 |
ARM_RELOC_PAIR | rLength4):
// ex: movw r1, :lower16:_x [thumb mode]
*kind = thumb_movw;
funcRel = false;
top = false;
thumbReloc = true;
break;
case ((ARM_RELOC_HALF | rLength8) << 16 |
ARM_RELOC_PAIR | rLength8):
// ex: movt r1, :upper16:_x [thumb mode]
*kind = thumb_movt;
funcRel = false;
top = true;
thumbReloc = true;
break;
case ((ARM_RELOC_HALF | rLength1) << 16 |
ARM_RELOC_PAIR | rLength1):
// ex: movw r1, :lower16:_x [arm mode]
*kind = arm_movw;
funcRel = false;
top = false;
thumbReloc = false;
break;
case ((ARM_RELOC_HALF | rLength2) << 16 |
ARM_RELOC_PAIR | rLength2):
// ex: movt r1, :upper16:_x [arm mode]
*kind = arm_movt;
funcRel = false;
top = true;
thumbReloc = false;
break;
case ((ARM_RELOC_HALF | rScattered | rLength4) << 16 |
ARM_RELOC_PAIR | rLength4):
// ex: movw r1, :lower16:_x+a [thumb mode]
*kind = thumb_movw;
funcRel = false;
top = false;
thumbReloc = true;
break;
case ((ARM_RELOC_HALF | rScattered | rLength8) << 16 |
ARM_RELOC_PAIR | rLength8):
// ex: movt r1, :upper16:_x+a [thumb mode]
*kind = thumb_movt;
funcRel = false;
top = true;
thumbReloc = true;
break;
case ((ARM_RELOC_HALF | rScattered | rLength1) << 16 |
ARM_RELOC_PAIR | rLength1):
// ex: movw r1, :lower16:_x+a [arm mode]
*kind = arm_movw;
funcRel = false;
top = false;
thumbReloc = false;
break;
case ((ARM_RELOC_HALF | rScattered | rLength2) << 16 |
ARM_RELOC_PAIR | rLength2):
// ex: movt r1, :upper16:_x+a [arm mode]
*kind = arm_movt;
funcRel = false;
top = true;
thumbReloc = false;
break;
case ((ARM_RELOC_HALF | rExtern | rLength4) << 16 |
ARM_RELOC_PAIR | rLength4):
// ex: movw r1, :lower16:_undef [thumb mode]
*kind = thumb_movw;
funcRel = false;
top = false;
thumbReloc = true;
break;
case ((ARM_RELOC_HALF | rExtern | rLength8) << 16 |
ARM_RELOC_PAIR | rLength8):
// ex: movt r1, :upper16:_undef [thumb mode]
*kind = thumb_movt;
funcRel = false;
top = true;
thumbReloc = true;
break;
case ((ARM_RELOC_HALF | rExtern | rLength1) << 16 |
ARM_RELOC_PAIR | rLength1):
// ex: movw r1, :lower16:_undef [arm mode]
*kind = arm_movw;
funcRel = false;
top = false;
thumbReloc = false;
break;
case ((ARM_RELOC_HALF | rExtern | rLength2) << 16 |
ARM_RELOC_PAIR | rLength2):
// ex: movt r1, :upper16:_undef [arm mode]
*kind = arm_movt;
funcRel = false;
top = true;
thumbReloc = false;
break;
case ((ARM_RELOC_SECTDIFF | rScattered | rLength4) << 16 |
ARM_RELOC_PAIR | rScattered | rLength4):
case ((ARM_RELOC_LOCAL_SECTDIFF | rScattered | rLength4) << 16 |
ARM_RELOC_PAIR | rScattered | rLength4):
// ex: .long _foo - .
pointerDiff = true;
break;
default:
return make_dynamic_error_code(Twine("unsupported arm relocation pair"));
}
const uint8_t *fixupContent = &inAtom->rawContent()[offsetInAtom];
std::error_code ec;
uint32_t instruction = readU32(swap, fixupContent);
uint32_t value;
uint32_t fromAddress;
uint32_t toAddress;
uint16_t instruction16;
uint16_t other16;
const lld::Atom *fromTarget;
Reference::Addend offsetInTo;
Reference::Addend offsetInFrom;
if (pointerDiff) {
toAddress = reloc1.value;
fromAddress = reloc2.value;
ec = atomFromAddr(0, toAddress, target, &offsetInTo);
if (ec)
return ec;
ec = atomFromAddr(0, fromAddress, &fromTarget, &offsetInFrom);
if (ec)
return ec;
if (fromTarget != inAtom)
return make_dynamic_error_code(Twine("SECTDIFF relocation where "
"subtrahend label is not in atom"));
*kind = delta32;
value = clearThumbBit(instruction, *target);
*addend = value - (toAddress - fromAddress);
} else if (funcRel) {
toAddress = reloc1.value;
fromAddress = reloc2.value;
ec = atomFromAddr(0, toAddress, target, &offsetInTo);
if (ec)
return ec;
ec = atomFromAddr(0, fromAddress, &fromTarget, &offsetInFrom);
if (ec)
return ec;
if (fromTarget != inAtom)
return make_dynamic_error_code(Twine("ARM_RELOC_HALF_SECTDIFF relocation "
"where subtrahend label is not in atom"));
other16 = (reloc2.offset & 0xFFFF);
if (thumbReloc)
instruction16 = getWordFromThumbMov(instruction);
else
instruction16 = getWordFromArmMov(instruction);
if (top)
value = (instruction16 << 16) | other16;
else
value = (other16 << 16) | instruction16;
value = clearThumbBit(value, *target);
int64_t ta = (int64_t)value - (toAddress - fromAddress);
*addend = ta - offsetInFrom;
return std::error_code();
} else {
uint32_t sectIndex;
if (thumbReloc)
instruction16 = getWordFromThumbMov(instruction);
else
instruction16 = getWordFromArmMov(instruction);
other16 = (reloc2.offset & 0xFFFF);
if (top)
value = (instruction16 << 16) | other16;
else
value = (other16 << 16) | instruction16;
if (reloc1.isExtern) {
ec = atomFromSymbolIndex(reloc1.symbol, target);
if (ec)
return ec;
*addend = value;
} else {
if (reloc1.scattered) {
toAddress = reloc1.value;
sectIndex = 0;
} else {
toAddress = value;
sectIndex = reloc1.symbol;
}
ec = atomFromAddr(sectIndex, toAddress, target, &offsetInTo);
if (ec)
return ec;
*addend = value - toAddress;
}
}
return std::error_code();
}
void KindHandler_arm::applyFixup(Reference::KindNamespace ns,
Reference::KindArch arch,
Reference::KindValue kindValue,
uint64_t addend, uint8_t *location,
uint64_t fixupAddress,
uint64_t targetAddress,
uint64_t inAtomAddress) {
if (ns != Reference::KindNamespace::mach_o)
return;
assert(arch == Reference::KindArch::ARM);
//int32_t *loc32 = reinterpret_cast<int32_t*>(location);
// FIXME: these writes may need a swap.
switch (kindValue) {
case thumb_b22:
// FIXME
break;
case thumb_movw:
// FIXME
break;
case thumb_movt:
// FIXME
break;
case thumb_movw_funcRel:
// FIXME
break;
case thumb_movt_funcRel:
// FIXME
break;
case arm_b24:
// FIXME
break;
case arm_movw:
// FIXME
break;
case arm_movt:
// FIXME
break;
case arm_movw_funcRel:
// FIXME
break;
case arm_movt_funcRel:
// FIXME
break;
case pointer32:
// FIXME
break;
case delta32:
// FIXME
break;
case lazyPointer:
case lazyImmediateLocation:
// do nothing
break;
case invalid:
llvm_unreachable("invalid ARM Reference Kind");
break;
}
}
} // namespace mach_o
} // namespace lld
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