diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Object/MachOObjectFile.cpp | 282 |
1 files changed, 281 insertions, 1 deletions
diff --git a/llvm/lib/Object/MachOObjectFile.cpp b/llvm/lib/Object/MachOObjectFile.cpp index 7e7e8c49315..bb973b41db2 100644 --- a/llvm/lib/Object/MachOObjectFile.cpp +++ b/llvm/lib/Object/MachOObjectFile.cpp @@ -58,6 +58,17 @@ getSegmentLoadCommandNumSections(const MachOObjectFile *O, return S.nsects; } +static bool isPageZeroSegment(const MachOObjectFile *O, + const MachOObjectFile::LoadCommandInfo &L) { + if (O->is64Bit()) { + MachO::segment_command_64 S = O->getSegment64LoadCommand(L); + return StringRef("__PAGEZERO").equals(S.segname); + } + MachO::segment_command S = O->getSegmentLoadCommand(L); + return StringRef("__PAGEZERO").equals(S.segname); +} + + static const char * getSectionPtr(const MachOObjectFile *O, MachOObjectFile::LoadCommandInfo L, unsigned Sec) { @@ -229,7 +240,8 @@ MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian, bool Is64bits, std::error_code &EC) : ObjectFile(getMachOType(IsLittleEndian, Is64bits), Object), SymtabLoadCmd(nullptr), DysymtabLoadCmd(nullptr), - DataInCodeLoadCmd(nullptr), DyldInfoLoadCmd(nullptr) { + DataInCodeLoadCmd(nullptr), DyldInfoLoadCmd(nullptr), + HasPageZeroSegment(false) { uint32_t LoadCommandCount = this->getHeader().ncmds; MachO::LoadCommandType SegmentLoadType = is64Bit() ? MachO::LC_SEGMENT_64 : MachO::LC_SEGMENT; @@ -255,6 +267,8 @@ MachOObjectFile::MachOObjectFile(MemoryBufferRef Object, bool IsLittleEndian, const char *Sec = getSectionPtr(this, Load, J); Sections.push_back(Sec); } + if (isPageZeroSegment(this, Load)) + HasPageZeroSegment = true; } else if (Load.C.cmd == MachO::LC_LOAD_DYLIB || Load.C.cmd == MachO::LC_LOAD_WEAK_DYLIB || Load.C.cmd == MachO::LC_LAZY_LOAD_DYLIB || @@ -1860,6 +1874,272 @@ iterator_range<rebase_iterator> MachOObjectFile::rebaseTable() const { return rebaseTable(getDyldInfoRebaseOpcodes(), is64Bit()); } + +MachOBindEntry::MachOBindEntry(ArrayRef<uint8_t> Bytes, bool is64Bit, + Kind BK) + : Opcodes(Bytes), Ptr(Bytes.begin()), SegmentOffset(0), SegmentIndex(0), + Ordinal(0), Flags(0), Addend(0), RemainingLoopCount(0), AdvanceAmount(0), + BindType(0), PointerSize(is64Bit ? 8 : 4), + TableKind(BK), Malformed(false), Done(false) {} + +void MachOBindEntry::moveToFirst() { + Ptr = Opcodes.begin(); + moveNext(); +} + +void MachOBindEntry::moveToEnd() { + Ptr = Opcodes.end(); + RemainingLoopCount = 0; + Done = true; +} + +void MachOBindEntry::moveNext() { + // If in the middle of some loop, move to next binding in loop. + SegmentOffset += AdvanceAmount; + if (RemainingLoopCount) { + --RemainingLoopCount; + return; + } + if (Ptr == Opcodes.end()) { + Done = true; + return; + } + bool More = true; + while (More && !Malformed) { + // Parse next opcode and set up next loop. + uint8_t Byte = *Ptr++; + uint8_t ImmValue = Byte & MachO::BIND_IMMEDIATE_MASK; + uint8_t Opcode = Byte & MachO::BIND_OPCODE_MASK; + int8_t SignExtended; + const uint8_t *SymStart; + switch (Opcode) { + case MachO::BIND_OPCODE_DONE: + if (TableKind == Kind::Lazy) { + // Lazying bindings have a DONE opcode between entries. Need to ignore + // it to advance to next entry. But need not if this is last entry. + bool NotLastEntry = false; + for (const uint8_t *P = Ptr; P < Opcodes.end(); ++P) { + if (*P) { + NotLastEntry = true; + } + } + if (NotLastEntry) + break; + } + More = false; + Done = true; + moveToEnd(); + DEBUG_WITH_TYPE("mach-o-bind", llvm::dbgs() << "BIND_OPCODE_DONE\n"); + break; + case MachO::BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: + Ordinal = ImmValue; + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: " + << "Ordinal=" << Ordinal << "\n"); + break; + case MachO::BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: + Ordinal = readULEB128(); + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: " + << "Ordinal=" << Ordinal << "\n"); + break; + case MachO::BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: + if (ImmValue) { + SignExtended = MachO::BIND_OPCODE_MASK | ImmValue; + Ordinal = SignExtended; + } else + Ordinal = 0; + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: " + << "Ordinal=" << Ordinal << "\n"); + break; + case MachO::BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: + Flags = ImmValue; + SymStart = Ptr; + while (*Ptr) { + ++Ptr; + } + ++Ptr; + SymbolName = StringRef(reinterpret_cast<const char*>(SymStart), + Ptr-SymStart); + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: " + << "SymbolName=" << SymbolName << "\n"); + if (TableKind == Kind::Weak) { + if (ImmValue & MachO::BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION) + return; + } + break; + case MachO::BIND_OPCODE_SET_TYPE_IMM: + BindType = ImmValue; + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_SET_TYPE_IMM: " + << "BindType=" << (int)BindType << "\n"); + break; + case MachO::BIND_OPCODE_SET_ADDEND_SLEB: + Addend = readSLEB128(); + if (TableKind == Kind::Lazy) + Malformed = true; + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_SET_ADDEND_SLEB: " + << "Addend=" << Addend << "\n"); + break; + case MachO::BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: + SegmentIndex = ImmValue; + SegmentOffset = readULEB128(); + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: " + << "SegmentIndex=" << SegmentIndex << ", " + << format("SegmentOffset=0x%06X", SegmentOffset) + << "\n"); + break; + case MachO::BIND_OPCODE_ADD_ADDR_ULEB: + SegmentOffset += readULEB128(); + DEBUG_WITH_TYPE("mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_ADD_ADDR_ULEB: " + << format("SegmentOffset=0x%06X", + SegmentOffset) << "\n"); + break; + case MachO::BIND_OPCODE_DO_BIND: + AdvanceAmount = PointerSize; + RemainingLoopCount = 0; + DEBUG_WITH_TYPE("mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_DO_BIND: " + << format("SegmentOffset=0x%06X", + SegmentOffset) << "\n"); + return; + case MachO::BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB: + AdvanceAmount = readULEB128(); + RemainingLoopCount = 0; + if (TableKind == Kind::Lazy) + Malformed = true; + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_DO_BIND_IMM_TIMES: " + << format("SegmentOffset=0x%06X", SegmentOffset) + << ", AdvanceAmount=" << AdvanceAmount + << ", RemainingLoopCount=" << RemainingLoopCount + << "\n"); + return; + case MachO::BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: + AdvanceAmount = ImmValue * PointerSize; + RemainingLoopCount = 0; + if (TableKind == Kind::Lazy) + Malformed = true; + DEBUG_WITH_TYPE("mach-o-bind", + llvm::dbgs() + << "BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: " + << format("SegmentOffset=0x%06X", + SegmentOffset) << "\n"); + return; + case MachO::BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: + RemainingLoopCount = readULEB128() - 1; + AdvanceAmount = readULEB128() + PointerSize; + if (TableKind == Kind::Lazy) + Malformed = true; + DEBUG_WITH_TYPE( + "mach-o-bind", + llvm::dbgs() << "BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: " + << format("SegmentOffset=0x%06X", SegmentOffset) + << ", AdvanceAmount=" << AdvanceAmount + << ", RemainingLoopCount=" << RemainingLoopCount + << "\n"); + return; + default: + Malformed = true; + } + } +} + +uint64_t MachOBindEntry::readULEB128() { + unsigned Count; + uint64_t Result = decodeULEB128(Ptr, &Count); + Ptr += Count; + if (Ptr > Opcodes.end()) { + Ptr = Opcodes.end(); + Malformed = true; + } + return Result; +} + +int64_t MachOBindEntry::readSLEB128() { + unsigned Count; + int64_t Result = decodeSLEB128(Ptr, &Count); + Ptr += Count; + if (Ptr > Opcodes.end()) { + Ptr = Opcodes.end(); + Malformed = true; + } + return Result; +} + + +uint32_t MachOBindEntry::segmentIndex() const { return SegmentIndex; } + +uint64_t MachOBindEntry::segmentOffset() const { return SegmentOffset; } + +StringRef MachOBindEntry::typeName() const { + switch (BindType) { + case MachO::BIND_TYPE_POINTER: + return "pointer"; + case MachO::BIND_TYPE_TEXT_ABSOLUTE32: + return "text abs32"; + case MachO::BIND_TYPE_TEXT_PCREL32: + return "text rel32"; + } + return "unknown"; +} + +StringRef MachOBindEntry::symbolName() const { return SymbolName; } + +int64_t MachOBindEntry::addend() const { return Addend; } + +uint32_t MachOBindEntry::flags() const { return Flags; } + +int MachOBindEntry::ordinal() const { return Ordinal; } + +bool MachOBindEntry::operator==(const MachOBindEntry &Other) const { + assert(Opcodes == Other.Opcodes && "compare iterators of different files"); + return (Ptr == Other.Ptr) && + (RemainingLoopCount == Other.RemainingLoopCount) && + (Done == Other.Done); +} + +iterator_range<bind_iterator> +MachOObjectFile::bindTable(ArrayRef<uint8_t> Opcodes, bool is64, + MachOBindEntry::Kind BKind) { + MachOBindEntry Start(Opcodes, is64, BKind); + Start.moveToFirst(); + + MachOBindEntry Finish(Opcodes, is64, BKind); + Finish.moveToEnd(); + + return iterator_range<bind_iterator>(bind_iterator(Start), + bind_iterator(Finish)); +} + +iterator_range<bind_iterator> MachOObjectFile::bindTable() const { + return bindTable(getDyldInfoBindOpcodes(), is64Bit(), + MachOBindEntry::Kind::Regular); +} + +iterator_range<bind_iterator> MachOObjectFile::lazyBindTable() const { + return bindTable(getDyldInfoLazyBindOpcodes(), is64Bit(), + MachOBindEntry::Kind::Lazy); +} + +iterator_range<bind_iterator> MachOObjectFile::weakBindTable() const { + return bindTable(getDyldInfoWeakBindOpcodes(), is64Bit(), + MachOBindEntry::Kind::Weak); +} + StringRef MachOObjectFile::getSectionFinalSegmentName(DataRefImpl Sec) const { ArrayRef<char> Raw = getSectionRawFinalSegmentName(Sec); 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