diff options
Diffstat (limited to 'contrib/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp')
| -rw-r--r-- | contrib/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp | 499 |
1 files changed, 499 insertions, 0 deletions
diff --git a/contrib/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp b/contrib/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp new file mode 100644 index 0000000..4de46be --- /dev/null +++ b/contrib/llvm/lib/DebugInfo/DWARF/DWARFVerifier.cpp @@ -0,0 +1,499 @@ +//===- DWARFVerifier.cpp --------------------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +#include "llvm/DebugInfo/DWARF/DWARFVerifier.h" +#include "llvm/DebugInfo/DWARF/DWARFCompileUnit.h" +#include "llvm/DebugInfo/DWARF/DWARFContext.h" +#include "llvm/DebugInfo/DWARF/DWARFDebugLine.h" +#include "llvm/DebugInfo/DWARF/DWARFDie.h" +#include "llvm/DebugInfo/DWARF/DWARFFormValue.h" +#include "llvm/DebugInfo/DWARF/DWARFSection.h" +#include "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h" +#include "llvm/Support/raw_ostream.h" +#include <map> +#include <set> +#include <vector> + +using namespace llvm; +using namespace dwarf; +using namespace object; + +bool DWARFVerifier::verifyUnitHeader(const DWARFDataExtractor DebugInfoData, + uint32_t *Offset, unsigned UnitIndex, + uint8_t &UnitType, bool &isUnitDWARF64) { + uint32_t AbbrOffset, Length; + uint8_t AddrSize = 0; + uint16_t Version; + bool Success = true; + + bool ValidLength = false; + bool ValidVersion = false; + bool ValidAddrSize = false; + bool ValidType = true; + bool ValidAbbrevOffset = true; + + uint32_t OffsetStart = *Offset; + Length = DebugInfoData.getU32(Offset); + if (Length == UINT32_MAX) { + isUnitDWARF64 = true; + OS << format( + "Unit[%d] is in 64-bit DWARF format; cannot verify from this point.\n", + UnitIndex); + return false; + } + Version = DebugInfoData.getU16(Offset); + + if (Version >= 5) { + UnitType = DebugInfoData.getU8(Offset); + AddrSize = DebugInfoData.getU8(Offset); + AbbrOffset = DebugInfoData.getU32(Offset); + ValidType = DWARFUnit::isValidUnitType(UnitType); + } else { + UnitType = 0; + AbbrOffset = DebugInfoData.getU32(Offset); + AddrSize = DebugInfoData.getU8(Offset); + } + + if (!DCtx.getDebugAbbrev()->getAbbreviationDeclarationSet(AbbrOffset)) + ValidAbbrevOffset = false; + + ValidLength = DebugInfoData.isValidOffset(OffsetStart + Length + 3); + ValidVersion = DWARFContext::isSupportedVersion(Version); + ValidAddrSize = AddrSize == 4 || AddrSize == 8; + if (!ValidLength || !ValidVersion || !ValidAddrSize || !ValidAbbrevOffset || + !ValidType) { + Success = false; + OS << format("Units[%d] - start offset: 0x%08x \n", UnitIndex, OffsetStart); + if (!ValidLength) + OS << "\tError: The length for this unit is too " + "large for the .debug_info provided.\n"; + if (!ValidVersion) + OS << "\tError: The 16 bit unit header version is not valid.\n"; + if (!ValidType) + OS << "\tError: The unit type encoding is not valid.\n"; + if (!ValidAbbrevOffset) + OS << "\tError: The offset into the .debug_abbrev section is " + "not valid.\n"; + if (!ValidAddrSize) + OS << "\tError: The address size is unsupported.\n"; + } + *Offset = OffsetStart + Length + 4; + return Success; +} + +bool DWARFVerifier::verifyUnitContents(DWARFUnit Unit) { + uint32_t NumUnitErrors = 0; + unsigned NumDies = Unit.getNumDIEs(); + for (unsigned I = 0; I < NumDies; ++I) { + auto Die = Unit.getDIEAtIndex(I); + if (Die.getTag() == DW_TAG_null) + continue; + for (auto AttrValue : Die.attributes()) { + NumUnitErrors += verifyDebugInfoAttribute(Die, AttrValue); + NumUnitErrors += verifyDebugInfoForm(Die, AttrValue); + } + } + return NumUnitErrors == 0; +} + +bool DWARFVerifier::handleDebugInfo() { + OS << "Verifying .debug_info Unit Header Chain...\n"; + + DWARFDataExtractor DebugInfoData(DCtx.getInfoSection(), DCtx.isLittleEndian(), + 0); + uint32_t NumDebugInfoErrors = 0; + uint32_t OffsetStart = 0, Offset = 0, UnitIdx = 0; + uint8_t UnitType = 0; + bool isUnitDWARF64 = false; + bool isHeaderChainValid = true; + bool hasDIE = DebugInfoData.isValidOffset(Offset); + while (hasDIE) { + OffsetStart = Offset; + if (!verifyUnitHeader(DebugInfoData, &Offset, UnitIdx, UnitType, + isUnitDWARF64)) { + isHeaderChainValid = false; + if (isUnitDWARF64) + break; + } else { + std::unique_ptr<DWARFUnit> Unit; + switch (UnitType) { + case dwarf::DW_UT_type: + case dwarf::DW_UT_split_type: { + DWARFUnitSection<DWARFTypeUnit> TUSection{}; + Unit.reset(new DWARFTypeUnit( + DCtx, DCtx.getInfoSection(), DCtx.getDebugAbbrev(), + &DCtx.getRangeSection(), DCtx.getStringSection(), + DCtx.getStringOffsetSection(), &DCtx.getAppleObjCSection(), + DCtx.getLineSection(), DCtx.isLittleEndian(), false, TUSection, + nullptr)); + break; + } + case dwarf::DW_UT_skeleton: + case dwarf::DW_UT_split_compile: + case dwarf::DW_UT_compile: + case dwarf::DW_UT_partial: + // UnitType = 0 means that we are + // verifying a compile unit in DWARF v4. + case 0: { + DWARFUnitSection<DWARFCompileUnit> CUSection{}; + Unit.reset(new DWARFCompileUnit( + DCtx, DCtx.getInfoSection(), DCtx.getDebugAbbrev(), + &DCtx.getRangeSection(), DCtx.getStringSection(), + DCtx.getStringOffsetSection(), &DCtx.getAppleObjCSection(), + DCtx.getLineSection(), DCtx.isLittleEndian(), false, CUSection, + nullptr)); + break; + } + default: { llvm_unreachable("Invalid UnitType."); } + } + Unit->extract(DebugInfoData, &OffsetStart); + if (!verifyUnitContents(*Unit)) + ++NumDebugInfoErrors; + } + hasDIE = DebugInfoData.isValidOffset(Offset); + ++UnitIdx; + } + if (UnitIdx == 0 && !hasDIE) { + OS << "Warning: .debug_info is empty.\n"; + isHeaderChainValid = true; + } + NumDebugInfoErrors += verifyDebugInfoReferences(); + return (isHeaderChainValid && NumDebugInfoErrors == 0); +} + +unsigned DWARFVerifier::verifyDebugInfoAttribute(const DWARFDie &Die, + DWARFAttribute &AttrValue) { + unsigned NumErrors = 0; + const auto Attr = AttrValue.Attr; + switch (Attr) { + case DW_AT_ranges: + // Make sure the offset in the DW_AT_ranges attribute is valid. + if (auto SectionOffset = AttrValue.Value.getAsSectionOffset()) { + if (*SectionOffset >= DCtx.getRangeSection().Data.size()) { + ++NumErrors; + OS << "error: DW_AT_ranges offset is beyond .debug_ranges " + "bounds:\n"; + Die.dump(OS, 0); + OS << "\n"; + } + } else { + ++NumErrors; + OS << "error: DIE has invalid DW_AT_ranges encoding:\n"; + Die.dump(OS, 0); + OS << "\n"; + } + break; + case DW_AT_stmt_list: + // Make sure the offset in the DW_AT_stmt_list attribute is valid. + if (auto SectionOffset = AttrValue.Value.getAsSectionOffset()) { + if (*SectionOffset >= DCtx.getLineSection().Data.size()) { + ++NumErrors; + OS << "error: DW_AT_stmt_list offset is beyond .debug_line " + "bounds: " + << format("0x%08" PRIx64, *SectionOffset) << "\n"; + Die.dump(OS, 0); + OS << "\n"; + } + } else { + ++NumErrors; + OS << "error: DIE has invalid DW_AT_stmt_list encoding:\n"; + Die.dump(OS, 0); + OS << "\n"; + } + break; + + default: + break; + } + return NumErrors; +} + +unsigned DWARFVerifier::verifyDebugInfoForm(const DWARFDie &Die, + DWARFAttribute &AttrValue) { + unsigned NumErrors = 0; + const auto Form = AttrValue.Value.getForm(); + switch (Form) { + case DW_FORM_ref1: + case DW_FORM_ref2: + case DW_FORM_ref4: + case DW_FORM_ref8: + case DW_FORM_ref_udata: { + // Verify all CU relative references are valid CU offsets. + Optional<uint64_t> RefVal = AttrValue.Value.getAsReference(); + assert(RefVal); + if (RefVal) { + auto DieCU = Die.getDwarfUnit(); + auto CUSize = DieCU->getNextUnitOffset() - DieCU->getOffset(); + auto CUOffset = AttrValue.Value.getRawUValue(); + if (CUOffset >= CUSize) { + ++NumErrors; + OS << "error: " << FormEncodingString(Form) << " CU offset " + << format("0x%08" PRIx64, CUOffset) + << " is invalid (must be less than CU size of " + << format("0x%08" PRIx32, CUSize) << "):\n"; + Die.dump(OS, 0); + OS << "\n"; + } else { + // Valid reference, but we will verify it points to an actual + // DIE later. + ReferenceToDIEOffsets[*RefVal].insert(Die.getOffset()); + } + } + break; + } + case DW_FORM_ref_addr: { + // Verify all absolute DIE references have valid offsets in the + // .debug_info section. + Optional<uint64_t> RefVal = AttrValue.Value.getAsReference(); + assert(RefVal); + if (RefVal) { + if (*RefVal >= DCtx.getInfoSection().Data.size()) { + ++NumErrors; + OS << "error: DW_FORM_ref_addr offset beyond .debug_info " + "bounds:\n"; + Die.dump(OS, 0); + OS << "\n"; + } else { + // Valid reference, but we will verify it points to an actual + // DIE later. + ReferenceToDIEOffsets[*RefVal].insert(Die.getOffset()); + } + } + break; + } + case DW_FORM_strp: { + auto SecOffset = AttrValue.Value.getAsSectionOffset(); + assert(SecOffset); // DW_FORM_strp is a section offset. + if (SecOffset && *SecOffset >= DCtx.getStringSection().size()) { + ++NumErrors; + OS << "error: DW_FORM_strp offset beyond .debug_str bounds:\n"; + Die.dump(OS, 0); + OS << "\n"; + } + break; + } + default: + break; + } + return NumErrors; +} + +unsigned DWARFVerifier::verifyDebugInfoReferences() { + // Take all references and make sure they point to an actual DIE by + // getting the DIE by offset and emitting an error + OS << "Verifying .debug_info references...\n"; + unsigned NumErrors = 0; + for (auto Pair : ReferenceToDIEOffsets) { + auto Die = DCtx.getDIEForOffset(Pair.first); + if (Die) + continue; + ++NumErrors; + OS << "error: invalid DIE reference " << format("0x%08" PRIx64, Pair.first) + << ". Offset is in between DIEs:\n"; + for (auto Offset : Pair.second) { + auto ReferencingDie = DCtx.getDIEForOffset(Offset); + ReferencingDie.dump(OS, 0); + OS << "\n"; + } + OS << "\n"; + } + return NumErrors; +} + +void DWARFVerifier::verifyDebugLineStmtOffsets() { + std::map<uint64_t, DWARFDie> StmtListToDie; + for (const auto &CU : DCtx.compile_units()) { + auto Die = CU->getUnitDIE(); + // Get the attribute value as a section offset. No need to produce an + // error here if the encoding isn't correct because we validate this in + // the .debug_info verifier. + auto StmtSectionOffset = toSectionOffset(Die.find(DW_AT_stmt_list)); + if (!StmtSectionOffset) + continue; + const uint32_t LineTableOffset = *StmtSectionOffset; + auto LineTable = DCtx.getLineTableForUnit(CU.get()); + if (LineTableOffset < DCtx.getLineSection().Data.size()) { + if (!LineTable) { + ++NumDebugLineErrors; + OS << "error: .debug_line[" << format("0x%08" PRIx32, LineTableOffset) + << "] was not able to be parsed for CU:\n"; + Die.dump(OS, 0); + OS << '\n'; + continue; + } + } else { + // Make sure we don't get a valid line table back if the offset is wrong. + assert(LineTable == nullptr); + // Skip this line table as it isn't valid. No need to create an error + // here because we validate this in the .debug_info verifier. + continue; + } + auto Iter = StmtListToDie.find(LineTableOffset); + if (Iter != StmtListToDie.end()) { + ++NumDebugLineErrors; + OS << "error: two compile unit DIEs, " + << format("0x%08" PRIx32, Iter->second.getOffset()) << " and " + << format("0x%08" PRIx32, Die.getOffset()) + << ", have the same DW_AT_stmt_list section offset:\n"; + Iter->second.dump(OS, 0); + Die.dump(OS, 0); + OS << '\n'; + // Already verified this line table before, no need to do it again. + continue; + } + StmtListToDie[LineTableOffset] = Die; + } +} + +void DWARFVerifier::verifyDebugLineRows() { + for (const auto &CU : DCtx.compile_units()) { + auto Die = CU->getUnitDIE(); + auto LineTable = DCtx.getLineTableForUnit(CU.get()); + // If there is no line table we will have created an error in the + // .debug_info verifier or in verifyDebugLineStmtOffsets(). + if (!LineTable) + continue; + uint32_t MaxFileIndex = LineTable->Prologue.FileNames.size(); + uint64_t PrevAddress = 0; + uint32_t RowIndex = 0; + for (const auto &Row : LineTable->Rows) { + if (Row.Address < PrevAddress) { + ++NumDebugLineErrors; + OS << "error: .debug_line[" + << format("0x%08" PRIx64, + *toSectionOffset(Die.find(DW_AT_stmt_list))) + << "] row[" << RowIndex + << "] decreases in address from previous row:\n"; + + DWARFDebugLine::Row::dumpTableHeader(OS); + if (RowIndex > 0) + LineTable->Rows[RowIndex - 1].dump(OS); + Row.dump(OS); + OS << '\n'; + } + + if (Row.File > MaxFileIndex) { + ++NumDebugLineErrors; + OS << "error: .debug_line[" + << format("0x%08" PRIx64, + *toSectionOffset(Die.find(DW_AT_stmt_list))) + << "][" << RowIndex << "] has invalid file index " << Row.File + << " (valid values are [1," << MaxFileIndex << "]):\n"; + DWARFDebugLine::Row::dumpTableHeader(OS); + Row.dump(OS); + OS << '\n'; + } + if (Row.EndSequence) + PrevAddress = 0; + else + PrevAddress = Row.Address; + ++RowIndex; + } + } +} + +bool DWARFVerifier::handleDebugLine() { + NumDebugLineErrors = 0; + OS << "Verifying .debug_line...\n"; + verifyDebugLineStmtOffsets(); + verifyDebugLineRows(); + return NumDebugLineErrors == 0; +} + +bool DWARFVerifier::handleAppleNames() { + NumAppleNamesErrors = 0; + + DWARFDataExtractor AppleNamesSection(DCtx.getAppleNamesSection(), + DCtx.isLittleEndian(), 0); + DataExtractor StrData(DCtx.getStringSection(), DCtx.isLittleEndian(), 0); + DWARFAcceleratorTable AppleNames(AppleNamesSection, StrData); + + if (!AppleNames.extract()) { + return true; + } + + OS << "Verifying .apple_names...\n"; + + // Verify that all buckets have a valid hash index or are empty. + uint32_t NumBuckets = AppleNames.getNumBuckets(); + uint32_t NumHashes = AppleNames.getNumHashes(); + + uint32_t BucketsOffset = + AppleNames.getSizeHdr() + AppleNames.getHeaderDataLength(); + uint32_t HashesBase = BucketsOffset + NumBuckets * 4; + uint32_t OffsetsBase = HashesBase + NumHashes * 4; + + for (uint32_t BucketIdx = 0; BucketIdx < NumBuckets; ++BucketIdx) { + uint32_t HashIdx = AppleNamesSection.getU32(&BucketsOffset); + if (HashIdx >= NumHashes && HashIdx != UINT32_MAX) { + OS << format("error: Bucket[%d] has invalid hash index: %u\n", BucketIdx, + HashIdx); + ++NumAppleNamesErrors; + } + } + + uint32_t NumAtoms = AppleNames.getAtomsDesc().size(); + if (NumAtoms == 0) { + OS << "error: no atoms; failed to read HashData\n"; + ++NumAppleNamesErrors; + return false; + } + + if (!AppleNames.validateForms()) { + OS << "error: unsupported form; failed to read HashData\n"; + ++NumAppleNamesErrors; + return false; + } + + for (uint32_t HashIdx = 0; HashIdx < NumHashes; ++HashIdx) { + uint32_t HashOffset = HashesBase + 4 * HashIdx; + uint32_t DataOffset = OffsetsBase + 4 * HashIdx; + uint32_t Hash = AppleNamesSection.getU32(&HashOffset); + uint32_t HashDataOffset = AppleNamesSection.getU32(&DataOffset); + if (!AppleNamesSection.isValidOffsetForDataOfSize(HashDataOffset, + sizeof(uint64_t))) { + OS << format("error: Hash[%d] has invalid HashData offset: 0x%08x\n", + HashIdx, HashDataOffset); + ++NumAppleNamesErrors; + } + + uint32_t StrpOffset; + uint32_t StringOffset; + uint32_t StringCount = 0; + uint32_t DieOffset = dwarf::DW_INVALID_OFFSET; + + while ((StrpOffset = AppleNamesSection.getU32(&HashDataOffset)) != 0) { + const uint32_t NumHashDataObjects = + AppleNamesSection.getU32(&HashDataOffset); + for (uint32_t HashDataIdx = 0; HashDataIdx < NumHashDataObjects; + ++HashDataIdx) { + DieOffset = AppleNames.readAtoms(HashDataOffset); + if (!DCtx.getDIEForOffset(DieOffset)) { + const uint32_t BucketIdx = + NumBuckets ? (Hash % NumBuckets) : UINT32_MAX; + StringOffset = StrpOffset; + const char *Name = StrData.getCStr(&StringOffset); + if (!Name) + Name = "<NULL>"; + + OS << format( + "error: .apple_names Bucket[%d] Hash[%d] = 0x%08x " + "Str[%u] = 0x%08x " + "DIE[%d] = 0x%08x is not a valid DIE offset for \"%s\".\n", + BucketIdx, HashIdx, Hash, StringCount, StrpOffset, HashDataIdx, + DieOffset, Name); + + ++NumAppleNamesErrors; + } + } + ++StringCount; + } + } + return NumAppleNamesErrors == 0; +} |
