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All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ #include <stdint.h> #include <stdio.h> #include <string.h> #include <assert.h> #include <errno.h> #include <mach/machine.h> #include <mach-o/fat.h> #include <uuid/uuid.h> #include <TargetConditionals.h> #if !TARGET_OS_EXCLAVEKIT #include <mach-o/reloc.h> #include <libc_private.h> #endif // !TARGET_OS_EXCLAVEKIT #include "Image.h" #include "Misc.h" #include "CompactUnwind.h" #include "TargetPolicy.h" namespace mach_o { Image::Image(const void* buffer, size_t bufferSize, MappingKind kind) : _buffer((Header*)buffer), _bufferSize(bufferSize), _mappingKind(kind), _hasZerofillExpansion(false) { // figure out location of LINKEDIT switch ( kind ) { case MappingKind::wholeSliceMapped: _hasZerofillExpansion = false; break; case MappingKind::dyldLoadedPreFixups: case MappingKind::dyldLoadedPostFixups: // this is a loaded image with segments mapped at their respective VM addresses _hasZerofillExpansion = true; break; case MappingKind::unknown: _hasZerofillExpansion = inferIfZerofillExpanded(); break; } _linkeditBias = _buffer->computeLinkEditBias(_hasZerofillExpansion); // minimal check of load commands if ( Error err = _buffer->validStructureLoadCommands(bufferSize) ) return; // build parts makeExportsTrie(); makeSymbolTable(); makeRebaseOpcodes(); makeBindOpcodes(); makeLazyBindOpcodes(); makeWeakBindOpcodes(); makeChainedFixups(); makeFunctionStarts(); makeCompactUnwind(); makeSplitSegInfo(); makeFunctionVariants(); makeFunctionVariantFixups(); } // for dyld loaded images only Image::Image(const mach_header* mh) : _buffer((Header*)mh), _bufferSize(0), _mappingKind(MappingKind::dyldLoadedPostFixups) { // this is a loaded image with segments mapped at their respective VM addresses _hasZerofillExpansion = true; _linkeditBias = _buffer->computeLinkEditBias(_hasZerofillExpansion); // build parts makeExportsTrie(); makeSymbolTable(); makeRebaseOpcodes(); makeBindOpcodes(); makeLazyBindOpcodes(); makeWeakBindOpcodes(); makeChainedFixups(); makeFunctionStarts(); makeCompactUnwind(); makeSplitSegInfo(); makeFunctionVariants(); makeFunctionVariantFixups(); } // need move constructor because object has pointers to within itself (e.g. _exportsTrie points to _exportsTrieSpace) Image::Image(const Image&& other) : _buffer(other._buffer), _bufferSize(other._bufferSize), _linkeditBias(other._linkeditBias), _mappingKind(other._mappingKind), _hasZerofillExpansion(other._hasZerofillExpansion) { // build parts makeExportsTrie(); makeSymbolTable(); makeRebaseOpcodes(); makeBindOpcodes(); makeLazyBindOpcodes(); makeWeakBindOpcodes(); makeChainedFixups(); makeFunctionStarts(); makeCompactUnwind(); makeSplitSegInfo(); makeFunctionVariants(); makeFunctionVariantFixups(); } // used to figure out of mach-o was mapped with zero fill or not bool Image::inferIfZerofillExpanded() const { // MH_PRELOAD files can only be wholeSliceMapped because load commands and linkedit are not in segments if ( _buffer->isPreload() || _buffer->isFileSet() ) return false; // if file has no zero-fill, then both ways to load are the same if ( !_buffer->hasZerofillExpansion() ) return false; // if file is code-signed, check for code-sig-magic in both possible locations { uint32_t sigFileOffset; uint32_t sigSize; if ( _buffer->hasCodeSignature(sigFileOffset, sigSize) ) { if ( sigFileOffset < _bufferSize ) { const uint32_t* unexpandedLoc = (uint32_t*)((uint8_t*)_buffer + sigFileOffset); if ( *unexpandedLoc == 0xc00cdefa ) // CSMAGIC_EMBEDDED_SIGNATURE return false; const uint32_t* expandedLoc = (uint32_t*)((uint8_t*)_buffer + _buffer->zerofillExpansionAmount() + sigFileOffset); if ( *expandedLoc == 0xc00cdefa ) return true; } } } // FIXME: assert(false && "handle unsigned"); return false; } Error Image::validate() const { // validate mach_header and load commands if ( Error err = _buffer->valid(_bufferSize) ) return err; // create Policy object for this binary Policy policy(_buffer->arch(), _buffer->platformAndVersions(), _buffer->mh.filetype, false); // validate initializers if ( gImageValidateInitializers ) { if ( Error err = this->validInitializers(policy) ) return err; } // validate LINKEDIT if ( Error err = this->validLinkedit(policy) ) return err; return Error::none(); } Error Image::validLinkedit(const Policy& policy) const { // validate structure of linkedit if ( Error err = validStructureLinkedit(policy) ) return err; uint64_t maxVmOffset = 0x4000; uint32_t segCount = this->segmentCount(); MappedSegment segs[std::max(segCount,(uint32_t)1)]; for (uint32_t i=0; i < segCount; ++i) { segs[i] = this->segment(i); if ( segs[i].segName != "__LINKEDIT" ) { maxVmOffset = std::max(maxVmOffset, segs[i].runtimeOffset + segs[i].runtimeSize); } } std::span<const MappedSegment> segSpan{segs, segCount}; // if image has an exports trie, validate that if ( this->hasExportsTrie() ) { if ( Error err = this->exportsTrie().valid(header()->preferredLoadAddress(), maxVmOffset) ) return err; } // if image has a symbol table, validate that if ( this->hasSymbolTable() ) { if ( Error err = this->symbolTable().valid(maxVmOffset) ) return err; } // if image has rebase opcodes if ( this->hasRebaseOpcodes() ) { if ( Error err = this->rebaseOpcodes().valid(segSpan, _buffer->mayHaveTextFixups(), policy.enforceFixupsInWritableSegments()) ) return err; } // if image has bind opcodes if ( this->hasBindOpcodes() ) { if ( Error err = this->bindOpcodes().valid(segSpan, _buffer->linkedDylibCount(), _buffer->mayHaveTextFixups(), policy.enforceFixupsInWritableSegments()) ) return err; } // if image has lazy bind opcodes if ( this->hasLazyBindOpcodes() ) { if ( Error err = this->lazyBindOpcodes().valid(segSpan, _buffer->linkedDylibCount(), _buffer->mayHaveTextFixups(), policy.enforceFixupsInWritableSegments()) ) return err; } // if image has chained fixups if ( this->hasChainedFixups() ) { if ( Error err = this->chainedFixups().valid(_buffer->preferredLoadAddress(), segSpan) ) return err; } // if image has functions variant table if ( this->hasFunctionVariants() ) { if ( Error err = this->functionVariants().valid() ) return err; } return Error::none(); } namespace { struct LinkEditContentChunk { const char* name; uint32_t alignment; uint32_t fileOffset; size_t size; // only have a few chunks, so bubble sort is ok. Don't use libc's qsort because it may call malloc static void sort(LinkEditContentChunk array[], unsigned long count) { for ( unsigned i = 0; i < count - 1; ++i ) { bool done = true; for ( unsigned j = 0; j < count - i - 1; ++j ) { if ( array[j].fileOffset > array[j + 1].fileOffset ) { LinkEditContentChunk temp = array[j]; array[j] = array[j + 1]; array[j + 1] = temp; done = false; } } if ( done ) break; } } }; } // anonymous namespace #if !TARGET_OS_EXCLAVEKIT Error Image::validStructureLinkedit(const Policy& policy) const { // build vector of all blobs in LINKEDIT const uint32_t ptrSize = _buffer->pointerSize(); LinkEditContentChunk blobs[32]; __block LinkEditContentChunk* bp = blobs; __block uint32_t symCount = 0; __block uint32_t indSymCount = 0; __block bool hasIndSymTab = false; __block bool hasLocalRelocs = false; __block bool hasExternalRelocs = false; __block bool hasDyldInfo = false; __block bool hasChainedFixups = false; __block Error lcError; (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { switch ( cmd->cmd ) { case LC_SYMTAB: { const symtab_command* symbTabCmd = (symtab_command*)cmd; symCount = symbTabCmd->nsyms; if ( symCount != 0 ) { if ( symCount > 0x10000000 ) { lcError = Error("malformed mach-o image: symbol table too large"); stop = true; } size_t size = symCount * (ptrSize == 8 ? sizeof(nlist_64) : sizeof(struct nlist)); *bp++ = { "symbol table", ptrSize, symbTabCmd->symoff, (uint32_t)size }; } if ( symbTabCmd->strsize != 0 ) *bp++ = { "symbol table strings", 1, symbTabCmd->stroff, symbTabCmd->strsize }; } break; case LC_DYSYMTAB: { hasIndSymTab = true; const dysymtab_command* dySymTabCmd = (dysymtab_command*)cmd; if ( dySymTabCmd->nindirectsyms > 0x10000000 ) { lcError = Error("malformed mach-o image: indirect symbol table too large"); stop = true; } else if ( dySymTabCmd->ilocalsym != 0 ) { lcError = Error("malformed mach-o image: indirect symbol table ilocalsym != 0"); stop = true; } else if ( dySymTabCmd->iextdefsym != dySymTabCmd->nlocalsym ) { lcError = Error("malformed mach-o image: indirect symbol table iextdefsym != nlocalsym"); stop = true; } else if ( dySymTabCmd->iundefsym != (dySymTabCmd->iextdefsym + dySymTabCmd->nextdefsym) ) { lcError = Error("malformed mach-o image: indirect symbol table iundefsym != iextdefsym+nextdefsym"); stop = true; } indSymCount = dySymTabCmd->iundefsym + dySymTabCmd->nundefsym; if ( dySymTabCmd->nlocrel != 0 ) { hasLocalRelocs = true; *bp++ = { "local relocations", ptrSize, dySymTabCmd->locreloff, dySymTabCmd->nlocrel * sizeof(relocation_info) }; } if ( dySymTabCmd->nextrel != 0 ) { hasExternalRelocs = true; *bp++ = { "external relocations", ptrSize, dySymTabCmd->extreloff, dySymTabCmd->nextrel * sizeof(relocation_info) }; } if ( dySymTabCmd->nindirectsyms != 0 ) *bp++ = { "indirect symbol table", 4, dySymTabCmd->indirectsymoff, dySymTabCmd->nindirectsyms * 4 }; } break; case LC_DYLD_INFO_ONLY: hasDyldInfo = true; [[clang::fallthrough]]; case LC_DYLD_INFO: { const dyld_info_command* dyldInfoCmd = (dyld_info_command*)cmd; if ( dyldInfoCmd->rebase_size != 0 ) *bp++ = { "rebase opcodes", ptrSize, dyldInfoCmd->rebase_off, dyldInfoCmd->rebase_size }; if ( dyldInfoCmd->bind_size != 0 ) *bp++ = { "bind opcodes", ptrSize, dyldInfoCmd->bind_off, dyldInfoCmd->bind_size }; if ( dyldInfoCmd->weak_bind_size != 0 ) *bp++ = { "weak bind opcodes", ptrSize, dyldInfoCmd->weak_bind_off, dyldInfoCmd->weak_bind_size }; if ( dyldInfoCmd->lazy_bind_size != 0 ) *bp++ = { "lazy bind opcodes", ptrSize, dyldInfoCmd->lazy_bind_off, dyldInfoCmd->lazy_bind_size }; if ( dyldInfoCmd->export_size != 0 ) *bp++ = { "exports trie", ptrSize, dyldInfoCmd->export_off, dyldInfoCmd->export_size }; } break; case LC_SEGMENT_SPLIT_INFO: { const linkedit_data_command* splitSegCmd = (linkedit_data_command*)cmd; if ( splitSegCmd->datasize != 0 ) *bp++ = { "shared cache info", ptrSize, splitSegCmd->dataoff, splitSegCmd->datasize }; } break; case LC_ATOM_INFO: { const linkedit_data_command* relinkCmd = (linkedit_data_command*)cmd; if ( relinkCmd->datasize != 0 ) *bp++ = { "atom info", ptrSize, relinkCmd->dataoff, relinkCmd->datasize }; } break; case LC_FUNCTION_STARTS: { const linkedit_data_command* funStartsCmd = (linkedit_data_command*)cmd; if ( funStartsCmd->datasize != 0 ) *bp++ = { "function starts", ptrSize, funStartsCmd->dataoff, funStartsCmd->datasize }; } break; case LC_DATA_IN_CODE: { const linkedit_data_command* dataInCodeCmd = (linkedit_data_command*)cmd; if ( dataInCodeCmd->datasize != 0 ) *bp++ = { "data in code", ptrSize, dataInCodeCmd->dataoff, dataInCodeCmd->datasize }; } break; case LC_CODE_SIGNATURE: { const linkedit_data_command* codeSigCmd = (linkedit_data_command*)cmd; if ( codeSigCmd->datasize != 0 ) *bp++ = { "code signature", ptrSize, codeSigCmd->dataoff, codeSigCmd->datasize }; } break; case LC_DYLD_EXPORTS_TRIE: { const linkedit_data_command* exportsTrieCmd = (linkedit_data_command*)cmd; if ( exportsTrieCmd->datasize != 0 ) *bp++ = { "exports trie", ptrSize, exportsTrieCmd->dataoff, exportsTrieCmd->datasize }; } break; case LC_DYLD_CHAINED_FIXUPS: { const linkedit_data_command* chainedFixupsCmd = (linkedit_data_command*)cmd; hasChainedFixups = true; if ( chainedFixupsCmd->datasize != 0 ) *bp++ = { "chained fixups", ptrSize, chainedFixupsCmd->dataoff, chainedFixupsCmd->datasize }; } break; } }); if ( lcError ) return std::move(lcError); if ( hasIndSymTab && (symCount != indSymCount)) return Error("symbol count from symbol table and dynamic symbol table differ"); // check for bad combinations if ( hasDyldInfo && policy.enforceOneFixupEncoding() ) { if ( hasLocalRelocs ) return Error("malformed mach-o contains LC_DYLD_INFO_ONLY and local relocations"); if ( hasExternalRelocs ) return Error("malformed mach-o contains LC_DYLD_INFO_ONLY and external relocations"); } if ( hasChainedFixups ) { if ( hasLocalRelocs ) return Error("malformed mach-o contains LC_DYLD_CHAINED_FIXUPS and local relocations"); if ( hasExternalRelocs ) return Error("malformed mach-o contains LC_DYLD_CHAINED_FIXUPS and external relocations"); } if ( hasDyldInfo && hasChainedFixups ) return Error("malformed mach-o contains LC_DYLD_INFO and LC_DYLD_CHAINED_FIXUPS"); // find range of LINKEDIT __block uint64_t linkeditFileOffsetStart = 0; __block uint64_t linkeditFileOffsetEnd = 0; if ( _buffer->isObjectFile() || _buffer->isPreload() ) { // .o and -preload files don't have LINKEDIT, but the LINKEDIT content is still at the end of the file after the last section content _buffer->forEachSection(^(const Header::SectionInfo& info, bool& stop) { uint8_t sectType = (info.flags & SECTION_TYPE); bool isZeroFill = ((sectType == S_ZEROFILL) || (sectType == S_THREAD_LOCAL_ZEROFILL)); if ( isZeroFill ) return; uint64_t sectionEnd = info.fileOffset + info.size; if ( sectionEnd > linkeditFileOffsetStart ) linkeditFileOffsetStart = sectionEnd; }); linkeditFileOffsetEnd = _bufferSize; if ( linkeditFileOffsetStart == 0 ) { // if all sections are zerofill sections, look for symbol table as start of linkedit _buffer->forEachLoadCommandSafe(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_SYMTAB ) { const symtab_command* symTab = (symtab_command*)cmd; linkeditFileOffsetStart = symTab->symoff; } }); } } else { (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_SEGMENT_64 ) { const segment_command_64* segCmd = (segment_command_64*)cmd; if ( strcmp(segCmd->segname, "__LINKEDIT") == 0 ) { linkeditFileOffsetStart = segCmd->fileoff; linkeditFileOffsetEnd = segCmd->fileoff + segCmd->filesize; stop = true; } } else if ( cmd->cmd == LC_SEGMENT ) { const segment_command* segCmd = (segment_command*)cmd; if ( strcmp(segCmd->segname, "__LINKEDIT") == 0 ) { linkeditFileOffsetStart = segCmd->fileoff; linkeditFileOffsetEnd = segCmd->fileoff + segCmd->filesize; stop = true; } } }); if ( (linkeditFileOffsetStart == 0) || (linkeditFileOffsetEnd == 0) ) return Error("bad or unknown fileoffset/size for LINKEDIT"); } // sort blobs by file-offset and check for overlaps const unsigned long blobCount = bp - blobs; if ( blobCount == 0 ) { // ok for .o files or MH_FILESET to have no content and no symbols if ( _buffer->isObjectFile() || _buffer->isFileSet() ) return Error::none(); return Error("malformed mach-o has no LINKEDIT information"); } LinkEditContentChunk::sort(blobs, blobCount); uint64_t prevEnd = linkeditFileOffsetStart; const char* prevName = "start of LINKEDIT"; for ( unsigned long i = 0; i < blobCount; ++i ) { const LinkEditContentChunk& blob = blobs[i]; if ( blob.fileOffset < prevEnd ) { return Error("LINKEDIT overlap of %s and %s", prevName, blob.name); } if ( greaterThanAddOrOverflow((uint64_t)blob.fileOffset, blob.size, linkeditFileOffsetEnd) ) { return Error("LINKEDIT content '%s' extends beyond end of segment", blob.name); } if ( (blob.fileOffset & (blob.alignment - 1)) != 0 ) { // <rdar://problem/51115705> relax code sig alignment for pre iOS 13 if ( strcmp(blob.name, "code signature") == 0 ) { if ( policy.enforceCodeSignatureAligned() ) return Error("mis-aligned code signature"); } else { if ( policy.enforceLinkeditContentAlignment() ) return Error("mis-aligned LINKEDIT content '%s'", blob.name); } } prevEnd = blob.fileOffset + blob.size; prevName = blob.name; } return Error::none(); } struct VIS_HIDDEN SegmentRanges { struct SegmentRange { uint64_t vmAddrStart; uint64_t vmAddrEnd; uint32_t fileSize; }; bool contains(uint64_t vmAddr) const { for (const SegmentRange& range : segments) { if ( (range.vmAddrStart <= vmAddr) && (vmAddr < range.vmAddrEnd) ) return true; } return false; } private: SegmentRange localAlloc[8]; public: dyld3::Array<SegmentRange> segments { localAlloc, sizeof(localAlloc) / sizeof(localAlloc[0]) }; }; Error Image::validInitializers(const Policy& policy) const { // rdar://127245061 (ld-prime initializer verification fails on Go object files) // Go creates object files with segment protections set to 0, while normally // they're set to all. Object files consist of a single segment though, so // we can skip the checks entirely. if ( header()->isObjectFile() ) return Error::none(); uint64_t prefLoadAddress = header()->preferredLoadAddress(); uint64_t slide = header()->getSlide(); __block Error anErr; __block SegmentRanges executableSegments; header()->forEachSegment(^(const Header::SegmentInfo& info, bool& stop) { if ( (info.initProt & VM_PROT_EXECUTE) != 0 ) { executableSegments.segments.push_back({ info.vmaddr, info.vmaddr + info.vmsize, (uint32_t)info.fileSize }); } }); if (executableSegments.segments.empty()) { return Error("no executable segments"); } // validate LC_ROUTINES initializer header()->forEachLoadCommandSafe(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_ROUTINES ) { const routines_command* routines = (routines_command*)cmd; uint64_t dashInitAddr = routines->init_address; if ( !executableSegments.contains(dashInitAddr) ) { anErr = Error("LC_ROUTINES initializer 0x%08llX is not an offset to an executable segment", dashInitAddr); stop = true; } } else if ( cmd->cmd == LC_ROUTINES_64 ) { const routines_command_64* routines = (routines_command_64*)cmd; uint64_t dashInitAddr = routines->init_address; if ( !executableSegments.contains(dashInitAddr) ) { anErr = Error("LC_ROUTINES _64 initializer 0x%08llX is not an offset to an executable segment", dashInitAddr); stop = true; } } }); // validate any function pointers in __DATA,__mod_init_func section header()->forEachSection(^(const Header::SectionInfo& sectInfo, bool& stop) { uint8_t sectType = (sectInfo.flags & SECTION_TYPE); if ( (sectType == S_MOD_INIT_FUNC_POINTERS) || (sectType == S_MOD_TERM_FUNC_POINTERS) ) { if ( (sectInfo.size % header()->pointerSize()) != 0 ) { anErr = Error("section %.*s/%.*s size (%llu) is not a multiple of pointer-size", (int)sectInfo.segmentName.size(), sectInfo.segmentName.data(), (int)sectInfo.sectionName.size(), sectInfo.sectionName.data(), sectInfo.size); stop = true; return; } if ( (sectInfo.address % header()->pointerSize()) != 0 ) { anErr = Error("section %.*s/%.*s address (0x%llX) is not pointer aligned", (int)sectInfo.segmentName.size(), sectInfo.segmentName.data(), (int)sectInfo.sectionName.size(), sectInfo.sectionName.data(), sectInfo.address); stop = true; return; } const uint8_t* sectionContent = (uint8_t*)header() + sectInfo.fileOffset; if ( header()->inDyldCache() ) sectionContent = (uint8_t*)(sectInfo.address + header()->getSlide()); if ( gImageAssumeContentRebased ) { // in dyld, when this is called, the image is already rebased, so we can use pointers in section const uintptr_t* initsStart = (uintptr_t*)sectionContent; const uintptr_t* initsEnd = (uintptr_t*)((uint8_t*)sectionContent + sectInfo.size); for (const uintptr_t* p=initsStart; p < initsEnd; ++p) { if ( !executableSegments.contains(*p) ) { anErr = Error("initializer 0x%08lX is not in an executable segment", *p); break; } } } else { if ( header()->is64() ) { const uint64_t* initsStart = (uint64_t*)sectionContent; const uint64_t* initsEnd = (uint64_t*)((uint8_t*)sectionContent + sectInfo.size); for (const uint64_t* p=initsStart; p < initsEnd; ++p) { uint64_t anInit = *p; anInit -= prefLoadAddress; // FIXME: as a quick hack, the low 32-bits with either rebase opcodes or chained fixups is offset in image uint32_t low32 = (uint32_t)anInit; if ( !executableSegments.contains(prefLoadAddress+low32) ) { anErr = Error("initializer %lu/%llu is not in an executable segment", p-initsStart, sectInfo.size/8); break; } } } else { const uint32_t* initsStart = (uint32_t*)sectionContent; const uint32_t* initsEnd = (uint32_t*)((uint8_t*)sectionContent + sectInfo.size); for (const uint32_t* p=initsStart; p < initsEnd; ++p) { uint32_t anInit = *p; anInit -= (uint32_t)prefLoadAddress; // FIXME: as a quick hack, the low 26-bits with either rebase opcodes or chained fixups is offset in image uint32_t low26 = anInit & 0x03FFFFFF; if ( !executableSegments.contains(prefLoadAddress+low26) ) { anErr = Error("initializer %lu/%llu is not in an executable segment", p-initsStart, sectInfo.size/84); break; } } } } if ( sectType == S_MOD_TERM_FUNC_POINTERS ) { if ( header()->isDyldManaged() && header()->isArch("arm6e") ) anErr = Error("terminators section %.*s/%.*s not supported for arm64e", (int)sectInfo.segmentName.size(), sectInfo.segmentName.data(), (int)sectInfo.sectionName.size(), sectInfo.sectionName.data()); } } }); if ( anErr.hasError() ) return std::move(anErr); // validate offsets in __TEXT,__init_offsets header()->forEachSection(^(const Header::SectionInfo& sectInfo, bool& stop) { if ( (sectInfo.flags & SECTION_TYPE) == S_INIT_FUNC_OFFSETS ) { const uint8_t* content = (uint8_t*)(sectInfo.address + slide); if ( sectInfo.segInitProt & VM_PROT_WRITE ) { anErr = Error("initializer offsets section %.*s/%.*s must be in read-only segment", (int)sectInfo.segmentName.size(), sectInfo.segmentName.data(), (int)sectInfo.sectionName.size(), sectInfo.sectionName.data()); stop = true; return; } if ( (sectInfo.size % 4) != 0 ) { anErr = Error("initializer offsets section %.*s/%.*s has bad size", (int)sectInfo.segmentName.size(), sectInfo.segmentName.data(), (int)sectInfo.sectionName.size(), sectInfo.sectionName.data()); stop = true; return; } if ( (sectInfo.address % 4) != 0 ) { anErr = Error("initializer offsets section %.*s/%.*s is not 4-byte aligned", (int)sectInfo.segmentName.size(), sectInfo.segmentName.data(), (int)sectInfo.sectionName.size(), sectInfo.sectionName.data()); stop = true; return; } const uint32_t* initsStart = (uint32_t*)content; const uint32_t* initsEnd = (uint32_t*)((uint8_t*)content + sectInfo.size); for (const uint32_t* p=initsStart; p < initsEnd; ++p) { uint32_t anInitOffset = *p; if ( !executableSegments.contains(prefLoadAddress + anInitOffset) ) { anErr = Error("initializer 0x%08X is not an offset to an executable segment", anInitOffset); stop = true; break; } } } }); if ( anErr.hasError() ) return std::move(anErr); return Error::none(); } #endif // !TARGET_OS_EXCLAVEKIT void Image::makeExportsTrie() { // if image has an exports trie, use placement new to build ExportTrie object in _exportsTrieSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_DYLD_EXPORTS_TRIE ) { const linkedit_data_command* exportsTrie = (linkedit_data_command*)cmd; if ( exportsTrie->dataoff != 0 ) _exportsTrie = new (_exportsTrieSpace) ExportsTrie(_linkeditBias + exportsTrie->dataoff, exportsTrie->datasize); } else if ( (cmd->cmd == LC_DYLD_INFO) || (cmd->cmd == LC_DYLD_INFO_ONLY) ) { const dyld_info_command* dyldInfo = (dyld_info_command*)cmd; if ( dyldInfo->export_off != 0 ) _exportsTrie = new (_exportsTrieSpace) ExportsTrie(_linkeditBias + dyldInfo->export_off, dyldInfo->export_size); } }); } void Image::makeSymbolTable() { // if image has an nlist symbol table, use placement new to build SymbolTable object in _symbolTableSpace __block const symtab_command* symTabCmd = nullptr; __block const dysymtab_command* dynSymTabCmd = nullptr; (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_SYMTAB ) { symTabCmd = (symtab_command*)cmd; } else if ( cmd->cmd == LC_DYSYMTAB ) { dynSymTabCmd = (dysymtab_command*)cmd; } }); if ( symTabCmd == nullptr ) return; uint32_t nlocalsym = 0; uint32_t nextdefsym = 0; uint32_t nundefsym = 0; if ( dynSymTabCmd != nullptr ) { // some .o files do not have LC_DYSYMTAB nlocalsym = dynSymTabCmd->nlocalsym; nextdefsym = dynSymTabCmd->nextdefsym; nundefsym = dynSymTabCmd->nundefsym; } if ( _buffer->is64() ) { uint64_t preferredLoadAddress = _buffer->preferredLoadAddress(); const struct nlist_64* nlistArray = (struct nlist_64*)(_linkeditBias + symTabCmd->symoff); _symbolTable = new (_symbolTableSpace) NListSymbolTable(preferredLoadAddress, nlistArray, symTabCmd->nsyms, (char*)_linkeditBias + symTabCmd->stroff, symTabCmd->strsize, nlocalsym, nextdefsym, nundefsym); } else { uint32_t preferredLoadAddress = (uint32_t)_buffer->preferredLoadAddress(); const struct nlist* nlistArray = (struct nlist*)(_linkeditBias + symTabCmd->symoff); _symbolTable = new (_symbolTableSpace) NListSymbolTable(preferredLoadAddress, nlistArray, symTabCmd->nsyms, (char*)_linkeditBias + symTabCmd->stroff, symTabCmd->strsize, nlocalsym, nextdefsym, nundefsym); } } void Image::makeRebaseOpcodes() { // if image has an rebase opcpdes, use placement new to build RebaseOpcodes object in _rebaseOpcodesSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( (cmd->cmd == LC_DYLD_INFO) || (cmd->cmd == LC_DYLD_INFO_ONLY) ) { const dyld_info_command* dyldInfoCmd = (dyld_info_command*)cmd; if ( dyldInfoCmd->rebase_size != 0 ) _rebaseOpcodes = new (_rebaseOpcodesSpace) RebaseOpcodes(_linkeditBias + dyldInfoCmd->rebase_off, dyldInfoCmd->rebase_size, _buffer->is64()); } }); } void Image::makeBindOpcodes() { // if image has an rebase opcpdes, use placement new to build BindOpcodes object in _bindOpcodesSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( (cmd->cmd == LC_DYLD_INFO) || (cmd->cmd == LC_DYLD_INFO_ONLY) ) { const dyld_info_command* dyldInfoCmd = (dyld_info_command*)cmd; if ( dyldInfoCmd->bind_size != 0 ) _bindOpcodes = new (_bindOpcodesSpace) BindOpcodes(_linkeditBias + dyldInfoCmd->bind_off, dyldInfoCmd->bind_size, _buffer->is64()); } }); } void Image::makeLazyBindOpcodes() { // if image has an rebase opcpdes, use placement new to build LazyBindOpcodes object in _lazyBindOpcodesSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( (cmd->cmd == LC_DYLD_INFO) || (cmd->cmd == LC_DYLD_INFO_ONLY) ) { const dyld_info_command* dyldInfoCmd = (dyld_info_command*)cmd; if ( dyldInfoCmd->lazy_bind_size != 0 ) _lazyBindOpcodes = new (_lazyBindOpcodesSpace) LazyBindOpcodes(_linkeditBias + dyldInfoCmd->lazy_bind_off, dyldInfoCmd->lazy_bind_size, _buffer->is64()); } }); } void Image::makeWeakBindOpcodes() { // if image has an rebase opcpdes, use placement new to build BindOpcodes object in _weakBindOpcodesSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( (cmd->cmd == LC_DYLD_INFO) || (cmd->cmd == LC_DYLD_INFO_ONLY) ) { const dyld_info_command* dyldInfoCmd = (dyld_info_command*)cmd; if ( dyldInfoCmd->weak_bind_size != 0 ) _weakBindOpcodes = new (_weakBindOpcodesSpace) BindOpcodes(_linkeditBias + dyldInfoCmd->weak_bind_off, dyldInfoCmd->weak_bind_size, _buffer->is64()); } }); } void Image::makeChainedFixups() { // if image has an fixup chains, use placement new to build ChainedFixups object in _chainedFixupsSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_DYLD_CHAINED_FIXUPS ) { const linkedit_data_command* chainedFixupsCmd = (linkedit_data_command*)cmd; if ( chainedFixupsCmd->datasize != 0 ) { const dyld_chained_fixups_header* fixupsHeader = (dyld_chained_fixups_header*)(_linkeditBias + chainedFixupsCmd->dataoff); _chainedFixups = new (_chainedFixupsSpace) ChainedFixups(fixupsHeader, chainedFixupsCmd->datasize); stop = true; } } }); if ( !header()->isPreload() && !header()->isStaticExecutable() ) return; if ( _chainedFixups == nullptr ) { header()->forEachSection(^(const Header::SectionInfo& info, bool& stop) { if ( (info.sectionName == "__chain_fixups") && (info.segmentName == "__TEXT") ) { const dyld_chained_fixups_header* fixupsHeader = (dyld_chained_fixups_header*)((uint8_t*)header() + info.fileOffset); _chainedFixups = new (_chainedFixupsSpace) ChainedFixups(fixupsHeader, (size_t)info.size); } }); } } void Image::makeFunctionStarts() { // if image has an function starts, use placement new to build FunctionStarts object in _functionStartsSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_FUNCTION_STARTS ) { const linkedit_data_command* funcStartsCmd = (linkedit_data_command*)cmd; if ( funcStartsCmd->datasize != 0 ) { const uint8_t* functionsStartBytes = (uint8_t*)(_linkeditBias + funcStartsCmd->dataoff); _functionStarts = new (_functionStartsSpace) FunctionStarts(functionsStartBytes, funcStartsCmd->datasize); } } }); } void Image::makeCompactUnwind() { // if image has an a compact unwind section, use placement new to build CompactUnwind object in _compactUnwindSpace _buffer->forEachSection(^(const Header::SectionInfo& info, bool& stop) { if ( (info.sectionName == "__unwind_info") && info.segmentName.starts_with("__TEXT") ) { const uint8_t* sectionContent = (uint8_t*)_buffer + info.fileOffset; _compactUnwind = new (_compactUnwindSpace) CompactUnwind(_buffer->arch(), sectionContent, (size_t)info.size); stop = true; } }); } void Image::makeSplitSegInfo() { // if image has a split seg info load command, use placement new to build SplitSegInfo object in _splitSegInfoSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_SEGMENT_SPLIT_INFO ) { const linkedit_data_command* splitSegCmd = (linkedit_data_command*)cmd; const uint8_t* startBytes = (uint8_t*)(_linkeditBias + splitSegCmd->dataoff); _splitSegInfo = new (_splitSegSpace) SplitSegInfo(startBytes, splitSegCmd->datasize); stop = true; } }); } void Image::makeFunctionVariants() { // if image has a LC_FUNCTION_VARIANTS load command, use placement new to build FunctionVariants object in _functionVariantsSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_FUNCTION_VARIANTS ) { const linkedit_data_command* functionVariantsCmd = (linkedit_data_command*)cmd; const uint8_t* startBytes = (uint8_t*)(_linkeditBias + functionVariantsCmd->dataoff); _functionVariants = new (_functionVariantsSpace) FunctionVariants(std::span<const uint8_t>(startBytes, functionVariantsCmd->datasize)); stop = true; } }); } void Image::makeFunctionVariantFixups() { // if image has a LC_FUNCTION_VARIANT_FIXUPS load command, use placement new to build _functionVariantFixups object in _functionVariantFixupsSpace (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_FUNCTION_VARIANT_FIXUPS ) { const linkedit_data_command* functionVariantFixupsCmd = (linkedit_data_command*)cmd; const uint8_t* startBytes = (uint8_t*)(_linkeditBias + functionVariantFixupsCmd->dataoff); _functionVariantFixups = new (_functionVariantFixupsSpace) FunctionVariantFixups(std::span<const uint8_t>(startBytes, functionVariantFixupsCmd->datasize)); stop = true; } }); } uint32_t Image::segmentCount() const { __block uint32_t count = 0; (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( (cmd->cmd == LC_SEGMENT) || (cmd->cmd == LC_SEGMENT_64) ) ++count; }); return count; } MappedSegment Image::segment(uint32_t segIndex) const { __block MappedSegment result; __block uint32_t curSegIndex = 0; __block uint64_t textVmAddr = 0; (void)_buffer->forEachLoadCommand(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_SEGMENT_64 ) { const segment_command_64* segCmd = (segment_command_64*)cmd; if ( strcmp(segCmd->segname, "__TEXT") == 0 ) textVmAddr = segCmd->vmaddr; if ( curSegIndex == segIndex ) { result.runtimeOffset = segCmd->vmaddr - textVmAddr; if ( _hasZerofillExpansion ) result.content = (uint8_t*)_buffer + (segCmd->vmaddr - textVmAddr); else result.content = (uint8_t*)_buffer + segCmd->fileoff; result.runtimeSize = segCmd->vmsize; result.fileOffset = segCmd->fileoff; result.segName = segCmd->segname; result.readable = ((segCmd->initprot & VM_PROT_READ) != 0); result.writable = ((segCmd->initprot & VM_PROT_WRITE) != 0); result.executable = ((segCmd->initprot & VM_PROT_EXECUTE) != 0); stop = true; } ++curSegIndex; } else if ( cmd->cmd == LC_SEGMENT ) { const segment_command* segCmd = (segment_command*)cmd; if ( strcmp(segCmd->segname, "__TEXT") == 0 ) textVmAddr = segCmd->vmaddr; if ( curSegIndex == segIndex ) { result.runtimeOffset = segCmd->vmaddr - textVmAddr; if ( _hasZerofillExpansion ) result.content = (uint8_t*)_buffer + (segCmd->vmaddr - textVmAddr); else result.content = (uint8_t*)_buffer + segCmd->fileoff; result.runtimeSize = segCmd->vmsize; result.fileOffset = segCmd->fileoff; result.segName = segCmd->segname; result.readable = ((segCmd->initprot & VM_PROT_READ) != 0); result.writable = ((segCmd->initprot & VM_PROT_WRITE) != 0); result.executable = ((segCmd->initprot & VM_PROT_EXECUTE) != 0); stop = true; } ++curSegIndex; } }); return result; } void Image::withSegments(void (^callback)(std::span<const MappedSegment> segments)) const { const uint32_t count = segmentCount(); MappedSegment segments[count]; for (uint32_t segIndex=0; segIndex < count; ++segIndex) segments[segIndex] = this->segment(segIndex); callback(std::span(segments, count)); } // This is a high level abstraction for mach-o files. No matter the format, it returns all bind targets void Image::forEachBindTarget(void (^callback)(const Fixup::BindTarget& targetInfo, bool& stop)) const { if ( this->hasChainedFixups() ) { this->chainedFixups().forEachBindTarget(callback); } else if ( this->hasBindOpcodes() ) { // FIXME: Do we want to pass up the strong binds? this->bindOpcodes().forEachBindTarget(callback, ^(const char* symbolName) { }); if ( hasLazyBindOpcodes() ) this->lazyBindOpcodes().forEachBindTarget(callback, ^(const char* symbolName) { }); } } void Image::forEachFixup(void (^callback)(const Fixup& fixup, bool& stop)) const { withSegments(^(std::span<const MappedSegment> segments) { forEachFixup(segments, callback); }); } // This is a high level abstraction for mach-o files. No matter the format, it iterates all fixups void Image::forEachFixup(std::span<const MappedSegment> segments, void (^callback)(const Fixup& fixup, bool& stop)) const { const uint64_t prefLoadAddr = this->header()->preferredLoadAddress(); uint16_t fwPointerFormat; uint32_t fwStartsCount; const uint32_t* fwStarts; if ( this->hasChainedFixups() ) { const ChainedFixups& chainedFixups = this->chainedFixups(); // userland binary with LC_DYLD_CHAINED_FIXUPS or firmware with __chain_fixups section std::vector<uint64_t> segOffsetTable; if ( header()->isPreload() ) { // build segOffsetTable from chained fixups header for (int segIndex=0; ; ++segIndex) { const dyld_chained_starts_in_segment* segInfo = chainedFixups.startsForSegment(segIndex); if ( segInfo == nullptr ) break; segOffsetTable.push_back(segInfo->segment_offset); } } chainedFixups.forEachFixupChainStartLocation(segments, ^(const void* chainStart, uint32_t segIndex, uint32_t pageIndex, uint32_t pageSize, const ChainedFixups::PointerFormat& pf, bool& stop) { pf.forEachFixupLocationInChain(chainStart, prefLoadAddr, &segments[segIndex], segOffsetTable, pageIndex, pageSize, callback); }); } else if ( this->header()->hasFirmwareChainStarts(&fwPointerFormat, &fwStartsCount, &fwStarts) ) { // firmware binary with __TEXT,__chain_starts section // Note: for historical reasons firmware __chain_starts section use file-offsets from the start of __TEXT // but that can be changed with -fixup_chains_section_vm linker option. But which option is used is not // encoded in the binary, so we need a heuristic here. bool startOffsetsAreFileOffsets = true; if ( (fwStartsCount > 0) && (segments.back().fileOffset + segments.back().runtimeSize < fwStarts[fwStartsCount-1]) ) startOffsetsAreFileOffsets = false; const ChainedFixups::PointerFormat& pf = ChainedFixups::PointerFormat::make(fwPointerFormat); for (uint32_t i=0; i < fwStartsCount; ++i) { const void* chainStart = nullptr; if ( startOffsetsAreFileOffsets ) { chainStart = ((uint8_t*)this->header()) + segments[0].fileOffset + fwStarts[i]; } else { for (const MappedSegment& seg : segments) { uint32_t startOffset = fwStarts[i]; if ( (seg.runtimeOffset <= startOffset) && (startOffset < seg.runtimeOffset+seg.runtimeSize) ) { uint64_t vmOffsetInSegment = startOffset - seg.runtimeOffset; chainStart = ((uint8_t*)this->header()) + seg.fileOffset + vmOffsetInSegment; break; } } } pf.forEachFixupLocationInChain(chainStart, prefLoadAddr, nullptr, {}, 0, 0, ^(const Fixup& fixup, bool& stop) { Fixup fixupWithSeg = fixup; uint64_t chainOffset = (uint8_t*)fixup.location - ((uint8_t*)this->header()); // Note: firmware chains can cross segments, so we cannot pre-compute 'seg' for (size_t s=0; s < segments.size(); ++s) { if ( (segments[s].fileOffset <= chainOffset) && (chainOffset < segments[s].fileOffset+segments[s].runtimeSize) ) { fixupWithSeg.segment = &segments[s]; break; } } callback(fixupWithSeg, stop); }); } } else if ( this->header()->hasFirmwareRebaseRuns() ) { // firmware binary with __TEXT,__rebase_info section bool is64 = this->header()->is64(); this->header()->forEachFirmwareRebaseRuns(^(uint32_t address, bool& stop) { // Note: __rebase_info addresses are vmaddrs const MappedSegment* seg = nullptr; uint64_t segOffset = 0; for (size_t s=0; s < segments.size(); ++s) { uint64_t segStartAddresss = prefLoadAddr+segments[s].runtimeOffset; if ( (segStartAddresss <= address) && (address < segStartAddresss+segments[s].runtimeSize) ) { seg = &segments[s]; segOffset = address - segStartAddresss; break; } } if ( seg != nullptr ) { const void* loc = (uint8_t*)seg->content + segOffset; uint64_t targetVmAddr = is64 ? (*(uint64_t*)loc) : (*(uint32_t*)loc); Fixup fixup(loc, seg, targetVmAddr-prefLoadAddr); callback(fixup, stop); } }); } else if ( this->header()->hasOpcodeFixups() ) { // userland binary with LC_DYLD_INFO uint32_t bindOrdinal = 0; if ( this->hasBindOpcodes() ) { bindOrdinal = this->bindOpcodes().forEachBindLocation(segments, bindOrdinal, callback); } if ( this->hasLazyBindOpcodes() ) { this->lazyBindOpcodes().forEachBindLocation(segments, bindOrdinal, callback); } if ( this->hasRebaseOpcodes() ) { this->rebaseOpcodes().forEachRebaseLocation(segments, prefLoadAddr, callback); } } else { // unsupported format } } void Image::forEachFilesetImage(void (^callback)(const Image& entryImage, std::string_view name, bool& stop)) const { int64_t slide = header()->getSlide(); header()->forEachLoadCommandSafe(^(const load_command *cmd, bool &stop) { if (cmd->cmd == LC_FILESET_ENTRY) { const fileset_entry_command* app_cache_cmd = (const fileset_entry_command*)cmd; const char* name = (char*)app_cache_cmd + app_cache_cmd->entry_id.offset; void* entryStart = (void*)(app_cache_cmd->vmaddr + slide); size_t entrySize = _bufferSize - (size_t)((uint64_t)entryStart - (uint64_t)header()); Image entryImage(entryStart, entrySize, MappingKind::wholeSliceMapped); callback(entryImage, name, stop); return; } }); } std::span<const uint32_t> Image::indirectSymbolTable() const { uint32_t fileOffset; uint32_t count; if ( header()->hasIndirectSymbolTable(fileOffset, count) ) { return std::span<const uint32_t>((uint32_t*)(_linkeditBias + fileOffset), count); } return std::span<const uint32_t>(); } std::span<uint8_t> Image::atomInfo() const { uint32_t fileOffset; uint32_t count; if ( header()->hasAtomInfo(fileOffset, count) ) { return std::span<uint8_t>((uint8_t*)(_linkeditBias + fileOffset), count); } return std::span<uint8_t>(); } static void forEachPointerInSection(const Header* hdr, uint8_t sectionType, uint64_t prefLoadAddress, bool contentRebased, void (^callback)(uint32_t offset)) { hdr->forEachSection(^(const Header::SectionInfo& sectInfo, bool& stop) { if ( (sectInfo.flags & SECTION_TYPE) == sectionType ) { const uint8_t* sectionContent = (uint8_t*)hdr + sectInfo.fileOffset; if ( hdr->inDyldCache() ) sectionContent = (uint8_t*)(sectInfo.address + hdr->getSlide()); if ( contentRebased ) { // in dyld, when this is called, the image is already rebased, so we can use pointers in section const uintptr_t* initsStart = (uintptr_t*)sectionContent; const uintptr_t* initsEnd = (uintptr_t*)((uint8_t*)sectionContent + sectInfo.size); for (const uintptr_t* p=initsStart; p < initsEnd; ++p) { uintptr_t anInit = *p; uint32_t anInitOffset = (uint32_t)(anInit - prefLoadAddress); callback(anInitOffset); } } else { if ( hdr->is64() ) { const uint64_t* initsStart = (uint64_t*)sectionContent; const uint64_t* initsEnd = (uint64_t*)((uint8_t*)sectionContent + sectInfo.size); for (const uint64_t* p=initsStart; p < initsEnd; ++p) { uint64_t anInit = *p; // FIXME: as a quick hack, the low 32-bits with either rebase opcodes or chained fixups is offset in image callback((uint32_t)anInit); } } else { const uint32_t* initsStart = (uint32_t*)sectionContent; const uint32_t* initsEnd = (uint32_t*)((uint8_t*)sectionContent + sectInfo.size); for (const uint32_t* p=initsStart; p < initsEnd; ++p) { uint32_t anInitOffset = *p; // FIXME: as a quick hack, the low 26-bits with either rebase opcodes or chained fixups is offset in image callback(anInitOffset & 0x03FFFFFF); } } } } }); } void Image::forEachInitializer(bool contentRebased, void (^callback)(uint32_t offset)) const { const Header* hdr = header(); uint64_t prefLoadAddress = hdr->preferredLoadAddress(); // if dylib linked with -init linker option, that initializer is first hdr->forEachLoadCommandSafe(^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_ROUTINES ) { const routines_command* routines = (routines_command*)cmd; uint64_t dashInit = routines->init_address; callback((uint32_t)(dashInit - prefLoadAddress)); } else if ( cmd->cmd == LC_ROUTINES_64 ) { const routines_command_64* routines = (routines_command_64*)cmd; uint64_t dashInit = routines->init_address; callback((uint32_t)(dashInit - prefLoadAddress)); } }); // next any function pointers in __DATA,__mod_init_func section forEachPointerInSection(hdr, S_MOD_INIT_FUNC_POINTERS, prefLoadAddress, contentRebased, callback); // next any function pointers in __TEXT,__init_offsets hdr->forEachSection(^(const Header::SectionInfo& sectInfo, bool& stop) { if ( (sectInfo.flags & SECTION_TYPE) == S_INIT_FUNC_OFFSETS ) { const uint8_t* sectionContent = (uint8_t*)hdr + sectInfo.fileOffset; if ( hdr->inDyldCache() ) sectionContent = (uint8_t*)(sectInfo.address + hdr->getSlide()); const uint32_t* initsStart = (uint32_t*)sectionContent; const uint32_t* initsEnd = (uint32_t*)((uint8_t*)sectionContent + sectInfo.size); for (const uint32_t* p=initsStart; p < initsEnd; ++p) { uint32_t anInitOffset = *p; callback(anInitOffset); } } }); } void Image::forEachClassicTerminator(bool contentRebased, void (^callback)(uint32_t offset)) const { uint64_t prefLoadAddress = header()->preferredLoadAddress(); // any function pointers in __DATA,__mod_term_func section forEachPointerInSection(header(), S_MOD_TERM_FUNC_POINTERS, prefLoadAddress, contentRebased, callback); } } // namespace mach_o |