| //===-------- JITLink_EHFrameSupport.cpp - JITLink eh-frame utils ---------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "EHFrameSupportImpl.h" |
| |
| #include "llvm/BinaryFormat/Dwarf.h" |
| #include "llvm/Config/config.h" |
| #include "llvm/ExecutionEngine/JITLink/DWARFRecordSectionSplitter.h" |
| #include "llvm/ExecutionEngine/Orc/TargetProcess/RegisterEHFrames.h" |
| #include "llvm/Support/DynamicLibrary.h" |
| |
| #define DEBUG_TYPE "jitlink" |
| |
| namespace llvm { |
| namespace jitlink { |
| |
| EHFrameEdgeFixer::EHFrameEdgeFixer(StringRef EHFrameSectionName, |
| unsigned PointerSize, Edge::Kind Pointer32, |
| Edge::Kind Pointer64, Edge::Kind Delta32, |
| Edge::Kind Delta64, Edge::Kind NegDelta32) |
| : EHFrameSectionName(EHFrameSectionName), PointerSize(PointerSize), |
| Pointer32(Pointer32), Pointer64(Pointer64), Delta32(Delta32), |
| Delta64(Delta64), NegDelta32(NegDelta32) {} |
| |
| Error EHFrameEdgeFixer::operator()(LinkGraph &G) { |
| auto *EHFrame = G.findSectionByName(EHFrameSectionName); |
| |
| if (!EHFrame) { |
| LLVM_DEBUG({ |
| dbgs() << "EHFrameEdgeFixer: No " << EHFrameSectionName |
| << " section in \"" << G.getName() << "\". Nothing to do.\n"; |
| }); |
| return Error::success(); |
| } |
| |
| // Check that we support the graph's pointer size. |
| if (G.getPointerSize() != 4 && G.getPointerSize() != 8) |
| return make_error<JITLinkError>( |
| "EHFrameEdgeFixer only supports 32 and 64 bit targets"); |
| |
| LLVM_DEBUG({ |
| dbgs() << "EHFrameEdgeFixer: Processing " << EHFrameSectionName << " in \"" |
| << G.getName() << "\"...\n"; |
| }); |
| |
| ParseContext PC(G); |
| |
| // Build a map of all blocks and symbols in the text sections. We will use |
| // these for finding / building edge targets when processing FDEs. |
| for (auto &Sec : G.sections()) { |
| // Just record the most-canonical symbol (for eh-frame purposes) at each |
| // address. |
| for (auto *Sym : Sec.symbols()) { |
| auto &CurSym = PC.AddrToSym[Sym->getAddress()]; |
| if (!CurSym || (std::make_tuple(Sym->getLinkage(), Sym->getScope(), |
| !Sym->hasName(), Sym->getName()) < |
| std::make_tuple(CurSym->getLinkage(), CurSym->getScope(), |
| !CurSym->hasName(), CurSym->getName()))) |
| CurSym = Sym; |
| } |
| if (auto Err = PC.AddrToBlock.addBlocks(Sec.blocks(), |
| BlockAddressMap::includeNonNull)) |
| return Err; |
| } |
| |
| // Sort eh-frame blocks into address order to ensure we visit CIEs before |
| // their child FDEs. |
| std::vector<Block *> EHFrameBlocks; |
| for (auto *B : EHFrame->blocks()) |
| EHFrameBlocks.push_back(B); |
| llvm::sort(EHFrameBlocks, [](const Block *LHS, const Block *RHS) { |
| return LHS->getAddress() < RHS->getAddress(); |
| }); |
| |
| // Loop over the blocks in address order. |
| for (auto *B : EHFrameBlocks) |
| if (auto Err = processBlock(PC, *B)) |
| return Err; |
| |
| return Error::success(); |
| } |
| |
| static Expected<size_t> readCFIRecordLength(const Block &B, |
| BinaryStreamReader &R) { |
| uint32_t Length; |
| if (auto Err = R.readInteger(Length)) |
| return std::move(Err); |
| |
| // If Length < 0xffffffff then use the regular length field, otherwise |
| // read the extended length field. |
| if (Length != 0xffffffff) |
| return Length; |
| |
| uint64_t ExtendedLength; |
| if (auto Err = R.readInteger(ExtendedLength)) |
| return std::move(Err); |
| |
| if (ExtendedLength > std::numeric_limits<size_t>::max()) |
| return make_error<JITLinkError>( |
| "In CFI record at " + |
| formatv("{0:x}", B.getAddress() + R.getOffset() - 12) + |
| ", extended length of " + formatv("{0:x}", ExtendedLength) + |
| " exceeds address-range max (" + |
| formatv("{0:x}", std::numeric_limits<size_t>::max())); |
| |
| return ExtendedLength; |
| } |
| |
| Error EHFrameEdgeFixer::processBlock(ParseContext &PC, Block &B) { |
| |
| LLVM_DEBUG(dbgs() << " Processing block at " << B.getAddress() << "\n"); |
| |
| // eh-frame should not contain zero-fill blocks. |
| if (B.isZeroFill()) |
| return make_error<JITLinkError>("Unexpected zero-fill block in " + |
| EHFrameSectionName + " section"); |
| |
| if (B.getSize() == 0) { |
| LLVM_DEBUG(dbgs() << " Block is empty. Skipping.\n"); |
| return Error::success(); |
| } |
| |
| // Find the offsets of any existing edges from this block. |
| BlockEdgeMap BlockEdges; |
| for (auto &E : B.edges()) |
| if (E.isRelocation()) { |
| if (BlockEdges.count(E.getOffset())) |
| return make_error<JITLinkError>( |
| "Multiple relocations at offset " + |
| formatv("{0:x16}", E.getOffset()) + " in " + EHFrameSectionName + |
| " block at address " + formatv("{0:x16}", B.getAddress())); |
| |
| BlockEdges[E.getOffset()] = EdgeTarget(E); |
| } |
| |
| CIEInfosMap CIEInfos; |
| BinaryStreamReader BlockReader( |
| StringRef(B.getContent().data(), B.getContent().size()), |
| PC.G.getEndianness()); |
| while (!BlockReader.empty()) { |
| size_t RecordStartOffset = BlockReader.getOffset(); |
| |
| LLVM_DEBUG({ |
| dbgs() << " Processing CFI record at " |
| << (B.getAddress() + RecordStartOffset) << "\n"; |
| }); |
| |
| // Get the record length. |
| Expected<size_t> RecordRemaining = readCFIRecordLength(B, BlockReader); |
| if (!RecordRemaining) |
| return RecordRemaining.takeError(); |
| |
| if (BlockReader.bytesRemaining() < *RecordRemaining) |
| return make_error<JITLinkError>( |
| "Incomplete CFI record at " + |
| formatv("{0:x16}", B.getAddress() + RecordStartOffset)); |
| |
| // Read the CIE delta for this record. |
| uint64_t CIEDeltaFieldOffset = BlockReader.getOffset() - RecordStartOffset; |
| uint32_t CIEDelta; |
| if (auto Err = BlockReader.readInteger(CIEDelta)) |
| return Err; |
| |
| if (CIEDelta == 0) { |
| if (auto Err = processCIE(PC, B, RecordStartOffset, |
| CIEDeltaFieldOffset + *RecordRemaining, |
| CIEDeltaFieldOffset, BlockEdges)) |
| return Err; |
| } else { |
| if (auto Err = processFDE(PC, B, RecordStartOffset, |
| CIEDeltaFieldOffset + *RecordRemaining, |
| CIEDeltaFieldOffset, CIEDelta, BlockEdges)) |
| return Err; |
| } |
| |
| // Move to the next record. |
| BlockReader.setOffset(RecordStartOffset + CIEDeltaFieldOffset + |
| *RecordRemaining); |
| } |
| |
| return Error::success(); |
| } |
| |
| Error EHFrameEdgeFixer::processCIE(ParseContext &PC, Block &B, |
| size_t RecordOffset, size_t RecordLength, |
| size_t CIEDeltaFieldOffset, |
| const BlockEdgeMap &BlockEdges) { |
| |
| LLVM_DEBUG(dbgs() << " Record is CIE\n"); |
| |
| auto RecordContent = B.getContent().slice(RecordOffset, RecordLength); |
| BinaryStreamReader RecordReader( |
| StringRef(RecordContent.data(), RecordContent.size()), |
| PC.G.getEndianness()); |
| |
| // Skip past the CIE delta field: we've already processed this far. |
| RecordReader.setOffset(CIEDeltaFieldOffset + 4); |
| |
| auto &CIESymbol = |
| PC.G.addAnonymousSymbol(B, RecordOffset, RecordLength, false, false); |
| CIEInformation CIEInfo(CIESymbol); |
| |
| uint8_t Version = 0; |
| if (auto Err = RecordReader.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(RecordReader); |
| if (!AugInfo) |
| return AugInfo.takeError(); |
| |
| // Skip the EH Data field if present. |
| if (AugInfo->EHDataFieldPresent) |
| if (auto Err = RecordReader.skip(PC.G.getPointerSize())) |
| return Err; |
| |
| // Read and validate the code alignment factor. |
| { |
| uint64_t CodeAlignmentFactor = 0; |
| if (auto Err = RecordReader.readULEB128(CodeAlignmentFactor)) |
| return Err; |
| } |
| |
| // Read and validate the data alignment factor. |
| { |
| int64_t DataAlignmentFactor = 0; |
| if (auto Err = RecordReader.readSLEB128(DataAlignmentFactor)) |
| return Err; |
| } |
| |
| // Skip the return address register field. |
| if (auto Err = RecordReader.skip(1)) |
| return Err; |
| |
| if (AugInfo->AugmentationDataPresent) { |
| |
| CIEInfo.AugmentationDataPresent = true; |
| |
| uint64_t AugmentationDataLength = 0; |
| if (auto Err = RecordReader.readULEB128(AugmentationDataLength)) |
| return Err; |
| |
| uint32_t AugmentationDataStartOffset = RecordReader.getOffset(); |
| |
| uint8_t *NextField = &AugInfo->Fields[0]; |
| while (uint8_t Field = *NextField++) { |
| switch (Field) { |
| case 'L': |
| CIEInfo.LSDAPresent = true; |
| if (auto PE = readPointerEncoding(RecordReader, B, "LSDA")) |
| CIEInfo.LSDAEncoding = *PE; |
| else |
| return PE.takeError(); |
| break; |
| case 'P': { |
| auto PersonalityPointerEncoding = |
| readPointerEncoding(RecordReader, B, "personality"); |
| if (!PersonalityPointerEncoding) |
| return PersonalityPointerEncoding.takeError(); |
| if (auto Err = |
| getOrCreateEncodedPointerEdge( |
| PC, BlockEdges, *PersonalityPointerEncoding, RecordReader, |
| B, RecordOffset + RecordReader.getOffset(), "personality") |
| .takeError()) |
| return Err; |
| break; |
| } |
| case 'R': |
| if (auto PE = readPointerEncoding(RecordReader, B, "address")) { |
| CIEInfo.AddressEncoding = *PE; |
| if (CIEInfo.AddressEncoding == dwarf::DW_EH_PE_omit) |
| return make_error<JITLinkError>( |
| "Invalid address encoding DW_EH_PE_omit in CIE at " + |
| formatv("{0:x}", (B.getAddress() + RecordOffset).getValue())); |
| } else |
| return PE.takeError(); |
| break; |
| default: |
| llvm_unreachable("Invalid augmentation string field"); |
| } |
| } |
| |
| if (RecordReader.getOffset() - AugmentationDataStartOffset > |
| AugmentationDataLength) |
| return make_error<JITLinkError>("Read past the end of the augmentation " |
| "data while parsing fields"); |
| } |
| |
| assert(!PC.CIEInfos.count(CIESymbol.getAddress()) && |
| "Multiple CIEs recorded at the same address?"); |
| PC.CIEInfos[CIESymbol.getAddress()] = std::move(CIEInfo); |
| |
| return Error::success(); |
| } |
| |
| Error EHFrameEdgeFixer::processFDE(ParseContext &PC, Block &B, |
| size_t RecordOffset, size_t RecordLength, |
| size_t CIEDeltaFieldOffset, |
| uint32_t CIEDelta, |
| const BlockEdgeMap &BlockEdges) { |
| LLVM_DEBUG(dbgs() << " Record is FDE\n"); |
| |
| orc::ExecutorAddr RecordAddress = B.getAddress() + RecordOffset; |
| |
| auto RecordContent = B.getContent().slice(RecordOffset, RecordLength); |
| BinaryStreamReader RecordReader( |
| StringRef(RecordContent.data(), RecordContent.size()), |
| PC.G.getEndianness()); |
| |
| // Skip past the CIE delta field: we've already read this far. |
| RecordReader.setOffset(CIEDeltaFieldOffset + 4); |
| |
| auto &FDESymbol = |
| PC.G.addAnonymousSymbol(B, RecordOffset, RecordLength, false, false); |
| |
| CIEInformation *CIEInfo = nullptr; |
| |
| { |
| // Process the CIE pointer field. |
| auto CIEEdgeItr = BlockEdges.find(RecordOffset + CIEDeltaFieldOffset); |
| orc::ExecutorAddr CIEAddress = |
| RecordAddress + orc::ExecutorAddrDiff(CIEDeltaFieldOffset) - |
| orc::ExecutorAddrDiff(CIEDelta); |
| if (CIEEdgeItr == BlockEdges.end()) { |
| |
| LLVM_DEBUG({ |
| dbgs() << " Adding edge at " |
| << (RecordAddress + CIEDeltaFieldOffset) |
| << " to CIE at: " << CIEAddress << "\n"; |
| }); |
| if (auto CIEInfoOrErr = PC.findCIEInfo(CIEAddress)) |
| CIEInfo = *CIEInfoOrErr; |
| else |
| return CIEInfoOrErr.takeError(); |
| assert(CIEInfo->CIESymbol && "CIEInfo has no CIE symbol set"); |
| B.addEdge(NegDelta32, RecordOffset + CIEDeltaFieldOffset, |
| *CIEInfo->CIESymbol, 0); |
| } else { |
| LLVM_DEBUG({ |
| dbgs() << " Already has edge at " |
| << (RecordAddress + CIEDeltaFieldOffset) << " to CIE at " |
| << CIEAddress << "\n"; |
| }); |
| auto &EI = CIEEdgeItr->second; |
| if (EI.Addend) |
| return make_error<JITLinkError>( |
| "CIE edge at " + |
| formatv("{0:x16}", RecordAddress + CIEDeltaFieldOffset) + |
| " has non-zero addend"); |
| if (auto CIEInfoOrErr = PC.findCIEInfo(EI.Target->getAddress())) |
| CIEInfo = *CIEInfoOrErr; |
| else |
| return CIEInfoOrErr.takeError(); |
| } |
| } |
| |
| // Process the PC-Begin field. |
| LLVM_DEBUG({ |
| dbgs() << " Processing PC-begin at " |
| << (RecordAddress + RecordReader.getOffset()) << "\n"; |
| }); |
| if (auto PCBegin = getOrCreateEncodedPointerEdge( |
| PC, BlockEdges, CIEInfo->AddressEncoding, RecordReader, B, |
| RecordReader.getOffset(), "PC begin")) { |
| assert(*PCBegin && "PC-begin symbol not set"); |
| if ((*PCBegin)->isDefined()) { |
| // Add a keep-alive edge from the FDE target to the FDE to ensure that the |
| // FDE is kept alive if its target is. |
| LLVM_DEBUG({ |
| dbgs() << " Adding keep-alive edge from target at " |
| << (*PCBegin)->getBlock().getAddress() << " to FDE at " |
| << RecordAddress << "\n"; |
| }); |
| (*PCBegin)->getBlock().addEdge(Edge::KeepAlive, 0, FDESymbol, 0); |
| } else { |
| LLVM_DEBUG({ |
| dbgs() << " WARNING: Not adding keep-alive edge to FDE at " |
| << RecordAddress << ", which points to " |
| << ((*PCBegin)->isExternal() ? "external" : "absolute") |
| << " symbol \"" << (*PCBegin)->getName() |
| << "\" -- FDE must be kept alive manually or it will be " |
| << "dead stripped.\n"; |
| }); |
| } |
| } else |
| return PCBegin.takeError(); |
| |
| // Skip over the PC range size field. |
| if (auto Err = skipEncodedPointer(CIEInfo->AddressEncoding, RecordReader)) |
| return Err; |
| |
| if (CIEInfo->AugmentationDataPresent) { |
| uint64_t AugmentationDataSize; |
| if (auto Err = RecordReader.readULEB128(AugmentationDataSize)) |
| return Err; |
| |
| if (CIEInfo->LSDAPresent) |
| if (auto Err = getOrCreateEncodedPointerEdge( |
| PC, BlockEdges, CIEInfo->LSDAEncoding, RecordReader, B, |
| RecordReader.getOffset(), "LSDA") |
| .takeError()) |
| return Err; |
| } else { |
| LLVM_DEBUG(dbgs() << " Record does not have LSDA field.\n"); |
| } |
| |
| return Error::success(); |
| } |
| |
| Expected<EHFrameEdgeFixer::AugmentationInfo> |
| EHFrameEdgeFixer::parseAugmentationString(BinaryStreamReader &RecordReader) { |
| AugmentationInfo AugInfo; |
| uint8_t NextChar; |
| uint8_t *NextField = &AugInfo.Fields[0]; |
| |
| if (auto Err = RecordReader.readInteger(NextChar)) |
| return std::move(Err); |
| |
| while (NextChar != 0) { |
| switch (NextChar) { |
| case 'z': |
| AugInfo.AugmentationDataPresent = true; |
| break; |
| case 'e': |
| if (auto Err = RecordReader.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 = RecordReader.readInteger(NextChar)) |
| return std::move(Err); |
| } |
| |
| return std::move(AugInfo); |
| } |
| |
| Expected<uint8_t> EHFrameEdgeFixer::readPointerEncoding(BinaryStreamReader &R, |
| Block &InBlock, |
| const char *FieldName) { |
| using namespace dwarf; |
| |
| uint8_t PointerEncoding; |
| if (auto Err = R.readInteger(PointerEncoding)) |
| return std::move(Err); |
| |
| bool Supported = true; |
| switch (PointerEncoding & 0xf) { |
| case DW_EH_PE_uleb128: |
| case DW_EH_PE_udata2: |
| case DW_EH_PE_sleb128: |
| case DW_EH_PE_sdata2: |
| Supported = false; |
| break; |
| } |
| if (Supported) { |
| switch (PointerEncoding & 0x70) { |
| case DW_EH_PE_textrel: |
| case DW_EH_PE_datarel: |
| case DW_EH_PE_funcrel: |
| case DW_EH_PE_aligned: |
| Supported = false; |
| break; |
| } |
| } |
| |
| if (Supported) |
| return PointerEncoding; |
| |
| return make_error<JITLinkError>("Unsupported pointer encoding " + |
| formatv("{0:x2}", PointerEncoding) + " for " + |
| FieldName + "in CFI record at " + |
| formatv("{0:x16}", InBlock.getAddress())); |
| } |
| |
| Error EHFrameEdgeFixer::skipEncodedPointer(uint8_t PointerEncoding, |
| BinaryStreamReader &RecordReader) { |
| using namespace dwarf; |
| |
| // Switch absptr to corresponding udata encoding. |
| if ((PointerEncoding & 0xf) == DW_EH_PE_absptr) |
| PointerEncoding |= (PointerSize == 8) ? DW_EH_PE_udata8 : DW_EH_PE_udata4; |
| |
| switch (PointerEncoding & 0xf) { |
| case DW_EH_PE_udata4: |
| case DW_EH_PE_sdata4: |
| if (auto Err = RecordReader.skip(4)) |
| return Err; |
| break; |
| case DW_EH_PE_udata8: |
| case DW_EH_PE_sdata8: |
| if (auto Err = RecordReader.skip(8)) |
| return Err; |
| break; |
| default: |
| llvm_unreachable("Unrecognized encoding"); |
| } |
| return Error::success(); |
| } |
| |
| Expected<Symbol *> EHFrameEdgeFixer::getOrCreateEncodedPointerEdge( |
| ParseContext &PC, const BlockEdgeMap &BlockEdges, uint8_t PointerEncoding, |
| BinaryStreamReader &RecordReader, Block &BlockToFix, |
| size_t PointerFieldOffset, const char *FieldName) { |
| using namespace dwarf; |
| |
| if (PointerEncoding == DW_EH_PE_omit) |
| return nullptr; |
| |
| // If there's already an edge here then just skip the encoded pointer and |
| // return the edge's target. |
| { |
| auto EdgeI = BlockEdges.find(PointerFieldOffset); |
| if (EdgeI != BlockEdges.end()) { |
| LLVM_DEBUG({ |
| dbgs() << " Existing edge at " |
| << (BlockToFix.getAddress() + PointerFieldOffset) << " to " |
| << FieldName << " at " << EdgeI->second.Target->getAddress(); |
| if (EdgeI->second.Target->hasName()) |
| dbgs() << " (" << EdgeI->second.Target->getName() << ")"; |
| dbgs() << "\n"; |
| }); |
| if (auto Err = skipEncodedPointer(PointerEncoding, RecordReader)) |
| return std::move(Err); |
| return EdgeI->second.Target; |
| } |
| } |
| |
| // Switch absptr to corresponding udata encoding. |
| if ((PointerEncoding & 0xf) == DW_EH_PE_absptr) |
| PointerEncoding |= (PointerSize == 8) ? DW_EH_PE_udata8 : DW_EH_PE_udata4; |
| |
| // We need to create an edge. Start by reading the field value. |
| uint64_t FieldValue; |
| bool Is64Bit = false; |
| switch (PointerEncoding & 0xf) { |
| case DW_EH_PE_udata4: { |
| uint32_t Val; |
| if (auto Err = RecordReader.readInteger(Val)) |
| return std::move(Err); |
| FieldValue = Val; |
| break; |
| } |
| case DW_EH_PE_sdata4: { |
| uint32_t Val; |
| if (auto Err = RecordReader.readInteger(Val)) |
| return std::move(Err); |
| FieldValue = Val; |
| break; |
| } |
| case DW_EH_PE_udata8: |
| case DW_EH_PE_sdata8: |
| Is64Bit = true; |
| if (auto Err = RecordReader.readInteger(FieldValue)) |
| return std::move(Err); |
| break; |
| default: |
| llvm_unreachable("Unsupported encoding"); |
| } |
| |
| // Find the edge target and edge kind to use. |
| orc::ExecutorAddr Target; |
| Edge::Kind PtrEdgeKind = Edge::Invalid; |
| if ((PointerEncoding & 0x70) == DW_EH_PE_pcrel) { |
| Target = BlockToFix.getAddress() + PointerFieldOffset; |
| PtrEdgeKind = Is64Bit ? Delta64 : Delta32; |
| } else |
| PtrEdgeKind = Is64Bit ? Pointer64 : Pointer32; |
| Target += FieldValue; |
| |
| // Find or create a symbol to point the edge at. |
| auto TargetSym = getOrCreateSymbol(PC, Target); |
| if (!TargetSym) |
| return TargetSym.takeError(); |
| BlockToFix.addEdge(PtrEdgeKind, PointerFieldOffset, *TargetSym, 0); |
| |
| LLVM_DEBUG({ |
| dbgs() << " Adding edge at " |
| << (BlockToFix.getAddress() + PointerFieldOffset) << " to " |
| << FieldName << " at " << TargetSym->getAddress(); |
| if (TargetSym->hasName()) |
| dbgs() << " (" << TargetSym->getName() << ")"; |
| dbgs() << "\n"; |
| }); |
| |
| return &*TargetSym; |
| } |
| |
| Expected<Symbol &> EHFrameEdgeFixer::getOrCreateSymbol(ParseContext &PC, |
| orc::ExecutorAddr Addr) { |
| // See whether we have a canonical symbol for the given address already. |
| auto CanonicalSymI = PC.AddrToSym.find(Addr); |
| if (CanonicalSymI != PC.AddrToSym.end()) |
| return *CanonicalSymI->second; |
| |
| // Otherwise search for a block covering the address and create a new symbol. |
| auto *B = PC.AddrToBlock.getBlockCovering(Addr); |
| if (!B) |
| return make_error<JITLinkError>("No symbol or block covering address " + |
| formatv("{0:x16}", Addr)); |
| |
| auto &S = |
| PC.G.addAnonymousSymbol(*B, Addr - B->getAddress(), 0, false, false); |
| PC.AddrToSym[S.getAddress()] = &S; |
| return S; |
| } |
| |
| char EHFrameNullTerminator::NullTerminatorBlockContent[4] = {0, 0, 0, 0}; |
| |
| EHFrameNullTerminator::EHFrameNullTerminator(StringRef EHFrameSectionName) |
| : EHFrameSectionName(EHFrameSectionName) {} |
| |
| Error EHFrameNullTerminator::operator()(LinkGraph &G) { |
| auto *EHFrame = G.findSectionByName(EHFrameSectionName); |
| |
| if (!EHFrame) |
| return Error::success(); |
| |
| LLVM_DEBUG({ |
| dbgs() << "EHFrameNullTerminator adding null terminator to " |
| << EHFrameSectionName << "\n"; |
| }); |
| |
| auto &NullTerminatorBlock = |
| G.createContentBlock(*EHFrame, NullTerminatorBlockContent, |
| orc::ExecutorAddr(~uint64_t(4)), 1, 0); |
| G.addAnonymousSymbol(NullTerminatorBlock, 0, 4, false, true); |
| return Error::success(); |
| } |
| |
| EHFrameRegistrar::~EHFrameRegistrar() = default; |
| |
| Error InProcessEHFrameRegistrar::registerEHFrames( |
| orc::ExecutorAddrRange EHFrameSection) { |
| return orc::registerEHFrameSection(EHFrameSection.Start.toPtr<void *>(), |
| EHFrameSection.size()); |
| } |
| |
| Error InProcessEHFrameRegistrar::deregisterEHFrames( |
| orc::ExecutorAddrRange EHFrameSection) { |
| return orc::deregisterEHFrameSection(EHFrameSection.Start.toPtr<void *>(), |
| EHFrameSection.size()); |
| } |
| |
| EHFrameCFIBlockInspector EHFrameCFIBlockInspector::FromEdgeScan(Block &B) { |
| if (B.edges_empty()) |
| return EHFrameCFIBlockInspector(nullptr); |
| if (B.edges_size() == 1) |
| return EHFrameCFIBlockInspector(&*B.edges().begin()); |
| SmallVector<Edge *, 3> Es; |
| for (auto &E : B.edges()) |
| Es.push_back(&E); |
| assert(Es.size() >= 2 && Es.size() <= 3 && "Unexpected number of edges"); |
| llvm::sort(Es, [](const Edge *LHS, const Edge *RHS) { |
| return LHS->getOffset() < RHS->getOffset(); |
| }); |
| return EHFrameCFIBlockInspector(*Es[0], *Es[1], |
| Es.size() == 3 ? Es[2] : nullptr); |
| return EHFrameCFIBlockInspector(nullptr); |
| } |
| |
| EHFrameCFIBlockInspector::EHFrameCFIBlockInspector(Edge *PersonalityEdge) |
| : PersonalityEdge(PersonalityEdge) {} |
| |
| EHFrameCFIBlockInspector::EHFrameCFIBlockInspector(Edge &CIEEdge, |
| Edge &PCBeginEdge, |
| Edge *LSDAEdge) |
| : CIEEdge(&CIEEdge), PCBeginEdge(&PCBeginEdge), LSDAEdge(LSDAEdge) {} |
| |
| LinkGraphPassFunction |
| createEHFrameRecorderPass(const Triple &TT, |
| StoreFrameRangeFunction StoreRangeAddress) { |
| const char *EHFrameSectionName = nullptr; |
| if (TT.getObjectFormat() == Triple::MachO) |
| EHFrameSectionName = "__TEXT,__eh_frame"; |
| else |
| EHFrameSectionName = ".eh_frame"; |
| |
| auto RecordEHFrame = |
| [EHFrameSectionName, |
| StoreFrameRange = std::move(StoreRangeAddress)](LinkGraph &G) -> Error { |
| // Search for a non-empty eh-frame and record the address of the first |
| // symbol in it. |
| orc::ExecutorAddr Addr; |
| size_t Size = 0; |
| if (auto *S = G.findSectionByName(EHFrameSectionName)) { |
| auto R = SectionRange(*S); |
| Addr = R.getStart(); |
| Size = R.getSize(); |
| } |
| if (!Addr && Size != 0) |
| return make_error<JITLinkError>( |
| StringRef(EHFrameSectionName) + |
| " section can not have zero address with non-zero size"); |
| StoreFrameRange(Addr, Size); |
| return Error::success(); |
| }; |
| |
| return RecordEHFrame; |
| } |
| |
| } // end namespace jitlink |
| } // end namespace llvm |
