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[RuntimeDyld, PowerPC] Fix relocation detection overflow

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Code in RuntimeDyldELF currently uses 32-bit temporaries to detect
whether a PPC64 relocation target is out of range. This is incorrect,
and can mis-detect overflow where the distance between relocation site
and target is close to a multiple of 4GB. Fixed by using 64-bit
temporaries.

Noticed while debugging PR32650.

Reviewer: hfinkel

Differential Revision: https://reviews.llvm.org/D33403

llvm-svn: 303632
This commit is contained in:
Ulrich Weigand 2017-05-23 12:43:57 +00:00
parent 82a8c72e68
commit a9fdeda7a8
1 changed files with 8 additions and 8 deletions
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16
lib/ExecutionEngine/RuntimeDyld/RuntimeDyldELF.cpp
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@ -737,23 +737,23 @@ void RuntimeDyldELF::resolvePPC64Relocation(const SectionEntry &Section,
writeInt16BE(LocalAddress, applyPPCha(Delta));
} break;
case ELF::R_PPC64_ADDR32: {
int32_t Result = static_cast<int32_t>(Value + Addend);
if (SignExtend32<32>(Result) != Result)
int64_t Result = static_cast<int64_t>(Value + Addend);
if (SignExtend64<32>(Result) != Result)
llvm_unreachable("Relocation R_PPC64_ADDR32 overflow");
writeInt32BE(LocalAddress, Result);
} break;
case ELF::R_PPC64_REL24: {
uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
if (SignExtend32<26>(delta) != delta)
int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
if (SignExtend64<26>(delta) != delta)
llvm_unreachable("Relocation R_PPC64_REL24 overflow");
// Generates a 'bl <address>' instruction
writeInt32BE(LocalAddress, 0x48000001 | (delta & 0x03FFFFFC));
} break;
case ELF::R_PPC64_REL32: {
uint64_t FinalAddress = Section.getLoadAddressWithOffset(Offset);
int32_t delta = static_cast<int32_t>(Value - FinalAddress + Addend);
if (SignExtend32<32>(delta) != delta)
int64_t delta = static_cast<int64_t>(Value - FinalAddress + Addend);
if (SignExtend64<32>(delta) != delta)
llvm_unreachable("Relocation R_PPC64_REL32 overflow");
writeInt32BE(LocalAddress, delta);
} break;
@ -1344,9 +1344,9 @@ RuntimeDyldELF::processRelocationRef(
}
uint8_t *RelocTarget =
Sections[Value.SectionID].getAddressWithOffset(Value.Addend);
int32_t delta = static_cast<int32_t>(Target - RelocTarget);
int64_t delta = static_cast<int64_t>(Target - RelocTarget);
// If it is within 26-bits branch range, just set the branch target
if (SignExtend32<26>(delta) == delta) {
if (SignExtend64<26>(delta) == delta) {
RelocationEntry RE(SectionID, Offset, RelType, Value.Addend);
if (Value.SymbolName)
addRelocationForSymbol(RE, Value.SymbolName);