diff options
Diffstat (limited to 'llvm/lib/ExecutionEngine/JITLink/JITLink_EHFrameSupport.cpp')
| -rw-r--r-- | llvm/lib/ExecutionEngine/JITLink/JITLink_EHFrameSupport.cpp | 533 |
1 files changed, 0 insertions, 533 deletions
diff --git a/llvm/lib/ExecutionEngine/JITLink/JITLink_EHFrameSupport.cpp b/llvm/lib/ExecutionEngine/JITLink/JITLink_EHFrameSupport.cpp deleted file mode 100644 index 38c537b5c78..00000000000 --- a/llvm/lib/ExecutionEngine/JITLink/JITLink_EHFrameSupport.cpp +++ /dev/null @@ -1,533 +0,0 @@ -//===-------- JITLink_EHFrameSupport.cpp - JITLink eh-frame utils ---------===// -// -// The LLVM Compiler Infrastructure -// -// This file is distributed under the University of Illinois Open Source -// License. See LICENSE.TXT for details. -// -//===----------------------------------------------------------------------===// - -#include "JITLink_EHFrameSupportImpl.h" - -#include "llvm/BinaryFormat/Dwarf.h" -#include "llvm/Support/DynamicLibrary.h" - -#define DEBUG_TYPE "jitlink" - -namespace llvm { -namespace jitlink { - -EHFrameParser::EHFrameParser(AtomGraph &G, Section &EHFrameSection, - StringRef EHFrameContent, - JITTargetAddress EHFrameAddress, - Edge::Kind FDEToCIERelocKind, - Edge::Kind FDEToTargetRelocKind) - : G(G), EHFrameSection(EHFrameSection), EHFrameContent(EHFrameContent), - EHFrameAddress(EHFrameAddress), - EHFrameReader(EHFrameContent, G.getEndianness()), - FDEToCIERelocKind(FDEToCIERelocKind), - FDEToTargetRelocKind(FDEToTargetRelocKind) {} - -Error EHFrameParser::atomize() { - while (!EHFrameReader.empty()) { - size_t RecordOffset = EHFrameReader.getOffset(); - - LLVM_DEBUG({ - dbgs() << "Processing eh-frame record at " - << format("0x%016" PRIx64, EHFrameAddress + RecordOffset) - << " (offset " << RecordOffset << ")\n"; - }); - - size_t CIELength = 0; - uint32_t CIELengthField; - if (auto Err = EHFrameReader.readInteger(CIELengthField)) - return Err; - - // Process CIE length/extended-length fields to build the atom. - // - // The value of these fields describe the length of the *rest* of the CIE - // (not including data up to the end of the field itself) so we have to - // bump CIELength to include the data up to the end of the field: 4 bytes - // for Length, or 12 bytes (4 bytes + 8 bytes) for ExtendedLength. - if (CIELengthField == 0) // Length 0 means end of __eh_frame section. - break; - - // If the regular length field's value is 0xffffffff, use extended length. - if (CIELengthField == 0xffffffff) { - uint64_t CIEExtendedLengthField; - if (auto Err = EHFrameReader.readInteger(CIEExtendedLengthField)) - return Err; - if (CIEExtendedLengthField > EHFrameReader.bytesRemaining()) - return make_error<JITLinkError>("CIE record extends past the end of " - "the __eh_frame section"); - if (CIEExtendedLengthField + 12 > std::numeric_limits<size_t>::max()) - return make_error<JITLinkError>("CIE record too large to process"); - CIELength = CIEExtendedLengthField + 12; - } else { - if (CIELengthField > EHFrameReader.bytesRemaining()) - return make_error<JITLinkError>("CIE record extends past the end of " - "the __eh_frame section"); - CIELength = CIELengthField + 4; - } - - LLVM_DEBUG(dbgs() << " length: " << CIELength << "\n"); - - // Add an atom for this record. - CurRecordAtom = &G.addAnonymousAtom( - EHFrameSection, EHFrameAddress + RecordOffset, G.getPointerSize()); - CurRecordAtom->setContent(EHFrameContent.substr(RecordOffset, CIELength)); - - // Read the CIE Pointer. - size_t CIEPointerAddress = EHFrameAddress + EHFrameReader.getOffset(); - uint32_t CIEPointer; - if (auto Err = EHFrameReader.readInteger(CIEPointer)) - return Err; - - // Based on the CIE pointer value, parse this as a CIE or FDE record. - if (CIEPointer == 0) { - if (auto Err = processCIE()) - return Err; - } else { - if (auto Err = processFDE(CIEPointerAddress, CIEPointer)) - return Err; - } - - EHFrameReader.setOffset(RecordOffset + CIELength); - } - - return Error::success(); -} - -Expected<EHFrameParser::AugmentationInfo> -EHFrameParser::parseAugmentationString() { - AugmentationInfo AugInfo; - uint8_t NextChar; - uint8_t *NextField = &AugInfo.Fields[0]; - - if (auto Err = EHFrameReader.readInteger(NextChar)) - return std::move(Err); - - while (NextChar != 0) { - switch (NextChar) { - case 'z': - AugInfo.AugmentationDataPresent = true; - break; - case 'e': - if (auto Err = EHFrameReader.readInteger(NextChar)) - return std::move(Err); - if (NextChar != 'h') - return make_error<JITLinkError>("Unrecognized substring e" + - Twine(NextChar) + - " in augmentation string"); - AugInfo.EHDataFieldPresent = true; - break; - case 'L': - case 'P': - case 'R': - *NextField++ = NextChar; - break; - default: - return make_error<JITLinkError>("Unrecognized character " + - Twine(NextChar) + - " in augmentation string"); - } - - if (auto Err = EHFrameReader.readInteger(NextChar)) - return std::move(Err); - } - - return std::move(AugInfo); -} - -Expected<JITTargetAddress> EHFrameParser::readAbsolutePointer() { - static_assert(sizeof(JITTargetAddress) == sizeof(uint64_t), - "Result must be able to hold a uint64_t"); - JITTargetAddress Addr; - if (G.getPointerSize() == 8) { - if (auto Err = EHFrameReader.readInteger(Addr)) - return std::move(Err); - } else if (G.getPointerSize() == 4) { - uint32_t Addr32; - if (auto Err = EHFrameReader.readInteger(Addr32)) - return std::move(Err); - Addr = Addr32; - } else - llvm_unreachable("Pointer size is not 32-bit or 64-bit"); - return Addr; -} - -Error EHFrameParser::processCIE() { - // Use the dwarf namespace for convenient access to pointer encoding - // constants. - using namespace dwarf; - - LLVM_DEBUG(dbgs() << " Record is CIE\n"); - - /// Reset state for the new CIE. - LSDAFieldPresent = false; - - uint8_t Version = 0; - if (auto Err = EHFrameReader.readInteger(Version)) - return Err; - - if (Version != 0x01) - return make_error<JITLinkError>("Bad CIE version " + Twine(Version) + - " (should be 0x01) in eh-frame"); - - auto AugInfo = parseAugmentationString(); - if (!AugInfo) - return AugInfo.takeError(); - - // Skip the EH Data field if present. - if (AugInfo->EHDataFieldPresent) - if (auto Err = EHFrameReader.skip(G.getPointerSize())) - return Err; - - // Read and sanity check the code alignment factor. - { - uint64_t CodeAlignmentFactor = 0; - if (auto Err = EHFrameReader.readULEB128(CodeAlignmentFactor)) - return Err; - if (CodeAlignmentFactor != 1) - return make_error<JITLinkError>("Unsupported CIE code alignment factor " + - Twine(CodeAlignmentFactor) + - " (expected 1)"); - } - - // Read and sanity check the data alignment factor. - { - int64_t DataAlignmentFactor = 0; - if (auto Err = EHFrameReader.readSLEB128(DataAlignmentFactor)) - return Err; - if (DataAlignmentFactor != -8) - return make_error<JITLinkError>("Unsupported CIE data alignment factor " + - Twine(DataAlignmentFactor) + - " (expected -8)"); - } - - // Skip the return address register field. - if (auto Err = EHFrameReader.skip(1)) - return Err; - - uint64_t AugmentationDataLength = 0; - if (auto Err = EHFrameReader.readULEB128(AugmentationDataLength)) - return Err; - - uint32_t AugmentationDataStartOffset = EHFrameReader.getOffset(); - - uint8_t *NextField = &AugInfo->Fields[0]; - while (uint8_t Field = *NextField++) { - switch (Field) { - case 'L': { - LSDAFieldPresent = true; - uint8_t LSDAPointerEncoding; - if (auto Err = EHFrameReader.readInteger(LSDAPointerEncoding)) - return Err; - if (LSDAPointerEncoding != (DW_EH_PE_pcrel | DW_EH_PE_absptr)) - return make_error<JITLinkError>( - "Unsupported LSDA pointer encoding " + - formatv("{0:x2}", LSDAPointerEncoding) + " in CIE at " + - formatv("{0:x16}", CurRecordAtom->getAddress())); - break; - } - case 'P': { - uint8_t PersonalityPointerEncoding = 0; - if (auto Err = EHFrameReader.readInteger(PersonalityPointerEncoding)) - return Err; - if (PersonalityPointerEncoding != - (DW_EH_PE_indirect | DW_EH_PE_pcrel | DW_EH_PE_sdata4)) - return make_error<JITLinkError>( - "Unspported personality pointer " - "encoding " + - formatv("{0:x2}", PersonalityPointerEncoding) + " in CIE at " + - formatv("{0:x16}", CurRecordAtom->getAddress())); - uint32_t PersonalityPointerAddress; - if (auto Err = EHFrameReader.readInteger(PersonalityPointerAddress)) - return Err; - break; - } - case 'R': { - uint8_t FDEPointerEncoding; - if (auto Err = EHFrameReader.readInteger(FDEPointerEncoding)) - return Err; - if (FDEPointerEncoding != (DW_EH_PE_pcrel | DW_EH_PE_absptr)) - return make_error<JITLinkError>( - "Unsupported FDE address pointer " - "encoding " + - formatv("{0:x2}", FDEPointerEncoding) + " in CIE at " + - formatv("{0:x16}", CurRecordAtom->getAddress())); - break; - } - default: - llvm_unreachable("Invalid augmentation string field"); - } - } - - if (EHFrameReader.getOffset() - AugmentationDataStartOffset > - AugmentationDataLength) - return make_error<JITLinkError>("Read past the end of the augmentation " - "data while parsing fields"); - - return Error::success(); -} - -Error EHFrameParser::processFDE(JITTargetAddress CIEPointerAddress, - uint32_t CIEPointer) { - LLVM_DEBUG(dbgs() << " Record is FDE\n"); - - LLVM_DEBUG({ - dbgs() << " CIE pointer: " - << format("0x%016" PRIx64, CIEPointerAddress - CIEPointer) << "\n"; - }); - - auto CIEAtom = G.findAtomByAddress(CIEPointerAddress - CIEPointer); - if (!CIEAtom) - return CIEAtom.takeError(); - - // The CIEPointer looks good. Add a relocation. - CurRecordAtom->addEdge(FDEToCIERelocKind, - CIEPointerAddress - CurRecordAtom->getAddress(), - *CIEAtom, 0); - - // Read and sanity check the PC-start pointer and size. - JITTargetAddress PCBeginAddress = EHFrameAddress + EHFrameReader.getOffset(); - - auto PCBeginDelta = readAbsolutePointer(); - if (!PCBeginDelta) - return PCBeginDelta.takeError(); - - JITTargetAddress PCBegin = PCBeginAddress + *PCBeginDelta; - LLVM_DEBUG({ - dbgs() << " PC begin: " << format("0x%016" PRIx64, PCBegin) << "\n"; - }); - - auto *TargetAtom = G.getAtomByAddress(PCBegin); - - if (!TargetAtom) - return make_error<JITLinkError>("FDE PC-begin " + - formatv("{0:x16}", PCBegin) + - " does not point at atom"); - - if (TargetAtom->getAddress() != PCBegin) - return make_error<JITLinkError>( - "FDE PC-begin " + formatv("{0:x16}", PCBegin) + - " does not point to start of atom at " + - formatv("{0:x16}", TargetAtom->getAddress())); - - LLVM_DEBUG(dbgs() << " FDE target: " << *TargetAtom << "\n"); - - // The PC-start pointer and size look good. Add relocations. - CurRecordAtom->addEdge(FDEToTargetRelocKind, - PCBeginAddress - CurRecordAtom->getAddress(), - *TargetAtom, 0); - - // Add a keep-alive relocation from the function to the FDE to ensure it is - // not dead stripped. - TargetAtom->addEdge(Edge::KeepAlive, 0, *CurRecordAtom, 0); - - // Skip over the PC range size field. - if (auto Err = EHFrameReader.skip(G.getPointerSize())) - return Err; - - if (LSDAFieldPresent) { - uint64_t AugmentationDataSize; - if (auto Err = EHFrameReader.readULEB128(AugmentationDataSize)) - return Err; - if (AugmentationDataSize != G.getPointerSize()) - return make_error<JITLinkError>("Unexpected FDE augmentation data size " - "(expected " + - Twine(G.getPointerSize()) + ", got " + - Twine(AugmentationDataSize) + ")"); - JITTargetAddress LSDAAddress = EHFrameAddress + EHFrameReader.getOffset(); - auto LSDADelta = readAbsolutePointer(); - if (!LSDADelta) - return LSDADelta.takeError(); - - JITTargetAddress LSDA = LSDAAddress + *LSDADelta; - - auto *LSDAAtom = G.getAtomByAddress(LSDA); - - if (!LSDAAtom) - return make_error<JITLinkError>("FDE LSDA " + formatv("{0:x16}", LSDA) + - " does not point at atom"); - - if (LSDAAtom->getAddress() != LSDA) - return make_error<JITLinkError>( - "FDE LSDA " + formatv("{0:x16}", LSDA) + - " does not point to start of atom at " + - formatv("{0:x16}", LSDAAtom->getAddress())); - - LLVM_DEBUG(dbgs() << " FDE LSDA: " << *LSDAAtom << "\n"); - - // LSDA looks good. Add relocations. - CurRecordAtom->addEdge(FDEToTargetRelocKind, - LSDAAddress - CurRecordAtom->getAddress(), *LSDAAtom, - 0); - } - - return Error::success(); -} - -Error addEHFrame(AtomGraph &G, Section &EHFrameSection, - StringRef EHFrameContent, JITTargetAddress EHFrameAddress, - Edge::Kind FDEToCIERelocKind, - Edge::Kind FDEToTargetRelocKind) { - return EHFrameParser(G, EHFrameSection, EHFrameContent, EHFrameAddress, - FDEToCIERelocKind, FDEToTargetRelocKind) - .atomize(); -} - -// Determine whether we can register EH tables. -#if (defined(__GNUC__) && !defined(__ARM_EABI__) && !defined(__ia64__) && \ - !defined(__SEH__) && !defined(__USING_SJLJ_EXCEPTIONS__)) -#define HAVE_EHTABLE_SUPPORT 1 -#else -#define HAVE_EHTABLE_SUPPORT 0 -#endif - -#if HAVE_EHTABLE_SUPPORT -extern "C" void __register_frame(const void *); -extern "C" void __deregister_frame(const void *); - -Error registerFrameWrapper(const void *P) { - __register_frame(P); - return Error::success(); -} - -Error deregisterFrameWrapper(const void *P) { - __deregister_frame(P); - return Error::success(); -} - -#else - -// The building compiler does not have __(de)register_frame but -// it may be found at runtime in a dynamically-loaded library. -// For example, this happens when building LLVM with Visual C++ -// but using the MingW runtime. -static Error registerFrameWrapper(const void *P) { - static void((*RegisterFrame)(const void *)) = 0; - - if (!RegisterFrame) - *(void **)&RegisterFrame = - llvm::sys::DynamicLibrary::SearchForAddressOfSymbol("__register_frame"); - - if (RegisterFrame) { - RegisterFrame(P); - return Error::success(); - } - - return make_error<JITLinkError>("could not register eh-frame: " - "__register_frame function not found"); -} - -static Error deregisterFrameWrapper(const void *P) { - static void((*DeregisterFrame)(const void *)) = 0; - - if (!DeregisterFrame) - *(void **)&DeregisterFrame = - llvm::sys::DynamicLibrary::SearchForAddressOfSymbol( - "__deregister_frame"); - - if (DeregisterFrame) { - DeregisterFrame(P); - return Error::success(); - } - - return make_error<JITLinkError>("could not deregister eh-frame: " - "__deregister_frame function not found"); -} -#endif - -#ifdef __APPLE__ - -template <typename HandleFDEFn> -Error walkAppleEHFrameSection(const char *const SectionStart, - HandleFDEFn HandleFDE) { - const char *CurCFIRecord = SectionStart; - uint64_t Size = *reinterpret_cast<const uint32_t *>(CurCFIRecord); - - while (Size != 0) { - const char *OffsetField = CurCFIRecord + (Size == 0xffffffff ? 12 : 4); - if (Size == 0xffffffff) - Size = *reinterpret_cast<const uint64_t *>(CurCFIRecord + 4) + 12; - else - Size += 4; - uint32_t Offset = *reinterpret_cast<const uint32_t *>(OffsetField); - if (Offset != 0) - if (auto Err = HandleFDE(CurCFIRecord)) - return Err; - - LLVM_DEBUG({ - dbgs() << "Registering eh-frame section:\n"; - dbgs() << "Processing " << (Offset ? "FDE" : "CIE") << " @" - << (void *)CurCFIRecord << ": ["; - for (unsigned I = 0; I < Size; ++I) - dbgs() << format(" 0x%02" PRIx8, *(CurCFIRecord + I)); - dbgs() << " ]\n"; - }); - CurCFIRecord += Size; - - Size = *reinterpret_cast<const uint32_t *>(CurCFIRecord); - } - - return Error::success(); -} - -#endif // __APPLE__ - -Error registerEHFrameSection(const void *EHFrameSectionAddr) { -#ifdef __APPLE__ - // On Darwin __register_frame has to be called for each FDE entry. - return walkAppleEHFrameSection(static_cast<const char *>(EHFrameSectionAddr), - registerFrameWrapper); -#else - // On Linux __register_frame takes a single argument: - // a pointer to the start of the .eh_frame section. - - // How can it find the end? Because crtendS.o is linked - // in and it has an .eh_frame section with four zero chars. - return registerFrameWrapper(EHFrameSectionAddr); -#endif -} - -Error deregisterEHFrameSection(const void *EHFrameSectionAddr) { -#ifdef __APPLE__ - return walkAppleEHFrameSection(static_cast<const char *>(EHFrameSectionAddr), - deregisterFrameWrapper); -#else - return deregisterFrameWrapper(EHFrameSectionAddr); -#endif -} - -AtomGraphPassFunction createEHFrameRecorderPass(const Triple &TT, - JITTargetAddress &EHFrameAddr) { - const char *EHFrameSectionName = nullptr; - if (TT.getObjectFormat() == Triple::MachO) - EHFrameSectionName = "__eh_frame"; - else - EHFrameSectionName = ".eh_frame"; - - auto RecordEHFrame = [EHFrameSectionName, - &EHFrameAddr](AtomGraph &G) -> Error { - // Search for a non-empty eh-frame and record the address of the first atom - // in it. - JITTargetAddress Addr = 0; - for (auto &S : G.sections()) - if (S.getName() == EHFrameSectionName && !S.atoms_empty()) { - Addr = (*S.atoms().begin())->getAddress(); - for (auto *DA : S.atoms()) - if (DA->getAddress() < Addr) - Addr = DA->getAddress(); - break; - } - - EHFrameAddr = Addr; - return Error::success(); - }; - - return RecordEHFrame; -} - -} // end namespace jitlink -} // end namespace llvm |
