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2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 | /* * Copyright (c) 2017 Apple Inc. 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 "Array.h" #include "MachOLayout.h" #include "MachOFile.h" #include <TargetConditionals.h> #include "Defines.h" #if SUPPORT_CLASSIC_RELOCS #include <mach-o/reloc.h> #include <mach-o/x86_64/reloc.h> #endif #include <mach-o/nlist.h> // FIXME: We should get this from cctools #define DYLD_CACHE_ADJ_V2_FORMAT 0x7F namespace mach_o { // MARK: --- Layout methods --- Layout::Layout(MachOFileRef mf, std::span<SegmentLayout> segments, const LinkeditLayout& linkedit) : mf(std::move(mf)), segments(segments), linkedit(linkedit) { } uint64_t Layout::textUnslidVMAddr() const { for ( const SegmentLayout& segment : this->segments ) { if ( segment.kind == SegmentLayout::Kind::text ) return segment.vmAddr; } // MachOFile::preferredLoadAddress seems to return 0 if we didn't find __TEXT, so match it return 0; } bool Layout::isSwiftLibrary() const { if ( std::optional<uint32_t> flags = this->getObjcInfoFlags(); flags.has_value() ) { uint32_t swiftVersion = ((flags.value() >> 8) & 0xFF); return (swiftVersion != 0); } return false; } std::optional<uint32_t> Layout::getObjcInfoFlags() const { struct objc_image_info { int32_t version; uint32_t flags; }; __block std::optional<uint32_t> flags; this->mf->forEachSection(^(const dyld3::MachOFile::SectionInfo& sectInfo, bool malformedSectionRange, bool& stop) { if ( (strncmp(sectInfo.sectName, "__objc_imageinfo", 16) == 0) && (strncmp(sectInfo.segInfo.segName, "__DATA", 6) == 0) ) { uint64_t segmentOffset = sectInfo.sectFileOffset - sectInfo.segInfo.fileOffset; objc_image_info* info = (objc_image_info*)(this->segments[sectInfo.segInfo.segIndex].buffer + segmentOffset); flags = info->flags; stop = true; } }); return flags; } bool Layout::hasSection(std::string_view segmentName, std::string_view sectionName) const { __block bool result = false; this->mf->forEachSection(^(const dyld3::MachOFile::SectionInfo& sectInfo, bool malformedSectionRange, bool& stop) { if ( (sectInfo.segInfo.segName == segmentName) && (sectInfo.sectName == sectionName) ) { result = true; stop = true; } }); return result; } namespace { struct LinkEditContentChunk { const char* name; uint32_t alignment; uint32_t fileOffsetStart; uint32_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].fileOffsetStart > array[j+1].fileOffsetStart ) { LinkEditContentChunk temp = array[j]; array[j] = array[j+1]; array[j+1] = temp; done = false; } } if ( done ) break; } } }; } // anonymous namespace bool Layout::isValidLinkeditLayout(Diagnostics &diag, const char *path) const { typedef dyld3::MachOFile::Malformed Malformed; const uint32_t ptrSize = this->mf->pointerSize(); // build vector of all blobs in LINKEDIT LinkEditContentChunk blobs[32]; LinkEditContentChunk* bp = blobs; if ( const Linkedit& blob = this->linkedit.rebaseOpcodes; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"rebase opcodes", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.regularBindOpcodes; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"bind opcodes", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.weakBindOpcodes; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"weak bind opcodes", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.lazyBindOpcodes; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"lazy bind opcodes", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.exportsTrie; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"exports trie", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.chainedFixups; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"chained fixups", ptrSize, blob.fileOffset, blob.bufferSize }; } #if SUPPORT_CLASSIC_RELOCS if ( const Linkedit& blob = this->linkedit.localRelocs; blob.hasValue() ) { if ( blob.entryCount != 0 ) { uint32_t bufferSize = (uint32_t)(blob.entryCount * sizeof(relocation_info)); *bp++ = {"local relocations", ptrSize, blob.fileOffset, bufferSize }; } } if ( const Linkedit& blob = this->linkedit.externRelocs; blob.hasValue() ) { if ( blob.entryCount != 0 ) { uint32_t bufferSize = (uint32_t)(blob.entryCount * sizeof(relocation_info)); *bp++ = {"external relocations", ptrSize, blob.fileOffset, bufferSize }; } } #endif if ( const Linkedit& blob = this->linkedit.indirectSymbolTable; blob.hasValue() ) { if ( blob.entryCount != 0 ) { uint32_t bufferSize = (uint32_t)(blob.entryCount * sizeof(uint32_t)); *bp++ = {"indirect symbol table", 4, blob.fileOffset, bufferSize }; } } if ( const Linkedit& blob = this->linkedit.splitSegInfo; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"shared cache info", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.functionStarts; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"function starts", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.dataInCode; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"data in code", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.symbolTable; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"symbol table", ptrSize, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.symbolStrings; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"symbol table strings", 1, blob.fileOffset, blob.bufferSize }; } if ( const Linkedit& blob = this->linkedit.codeSignature; blob.hasValue() ) { if ( blob.bufferSize != 0 ) *bp++ = {"code signature", ptrSize, blob.fileOffset, blob.bufferSize }; } // check for bad combinations if ( (this->linkedit.dyldInfoCmd == LC_DYLD_INFO_ONLY) ) { if ( (this->linkedit.localRelocs.entryCount != 0) && this->mf->enforceFormat(Malformed::dyldInfoAndlocalRelocs) ) { diag.error("in '%s' malformed mach-o contains LC_DYLD_INFO_ONLY and local relocations", path); return false; } if ( this->linkedit.externRelocs.entryCount != 0 ) { diag.error("in '%s' malformed mach-o contains LC_DYLD_INFO_ONLY and external relocations", path); return false; } } bool checkMissingDyldInfo = true; #if BUILDING_DYLDINFO || BUILDING_APP_CACHE_UTIL checkMissingDyldInfo = this->mf->isDyldManaged() && !this->mf->isStaticExecutable(); #endif if ( (this->linkedit.dyldInfoCmd == 0 ) && !this->linkedit.hasDynSymTab && checkMissingDyldInfo ) { diag.error("in '%s' malformed mach-o misssing LC_DYLD_INFO and LC_DYSYMTAB", path); return false; } // FIXME: Remove this hack #if BUILDING_APP_CACHE_UTIL if ( this->mf->isFileSet() ) return true; #endif const unsigned long blobCount = bp - blobs; if ( blobCount == 0 ) { diag.error("in '%s' malformed mach-o missing LINKEDIT", path); return false; } // Find the linkedit uint32_t linkeditFileOffset = ~0U; uint32_t linkeditFileSize = ~0U; for ( const SegmentLayout& segment : this->segments ) { if ( segment.kind == SegmentLayout::Kind::linkedit ) { linkeditFileOffset = (uint32_t)segment.fileOffset; linkeditFileSize = (uint32_t)segment.fileSize; break; } } uint32_t linkeditFileEnd = linkeditFileOffset + linkeditFileSize; // sort blobs by file-offset and error on overlaps LinkEditContentChunk::sort(blobs, blobCount); uint32_t prevEnd = linkeditFileOffset; const char* prevName = "start of LINKEDIT"; for (unsigned long i=0; i < blobCount; ++i) { const LinkEditContentChunk& blob = blobs[i]; if ( blob.fileOffsetStart < prevEnd ) { diag.error("in '%s' LINKEDIT overlap of %s and %s", path, prevName, blob.name); return false; } if (dyld3::greaterThanAddOrOverflow(blob.fileOffsetStart, blob.size, linkeditFileEnd)) { diag.error("in '%s' LINKEDIT content '%s' extends beyond end of segment", path, blob.name); return false; } if ( (blob.fileOffsetStart & (blob.alignment-1)) != 0 ) { // <rdar://problem/51115705> relax code sig alignment for pre iOS13 Malformed kind = (strcmp(blob.name, "code signature") == 0) ? Malformed::codeSigAlignment : Malformed::linkeditAlignment; if ( this->mf->enforceFormat(kind) ) diag.error("in '%s' mis-aligned LINKEDIT content '%s'", path, blob.name); } prevEnd = blob.fileOffsetStart + blob.size; prevName = blob.name; } // Check for invalid symbol table sizes if ( this->linkedit.hasSymTab ) { const Linkedit& symbolTable = this->linkedit.symbolTable; if ( symbolTable.entryCount > 0x10000000 ) { diag.error("in '%s' malformed mach-o image: symbol table too large", path); return false; } if ( this->linkedit.hasDynSymTab ) { // validate indirect symbol table const Linkedit& localSymbolTable = this->linkedit.localSymbolTable; const Linkedit& globalSymbolTable = this->linkedit.globalSymbolTable; const Linkedit& undefSymbolTable = this->linkedit.undefSymbolTable; const Linkedit& indirectSymbolTable = this->linkedit.indirectSymbolTable; if ( indirectSymbolTable.entryCount != 0 ) { if ( indirectSymbolTable.entryCount > 0x10000000 ) { diag.error("in '%s' malformed mach-o image: indirect symbol table too large", path); return false; } } if ( (localSymbolTable.entryCount > symbolTable.entryCount) || (localSymbolTable.entryIndex > symbolTable.entryCount) ) { diag.error("in '%s' malformed mach-o image: indirect symbol table local symbol count exceeds total symbols", path); return false; } if ( (localSymbolTable.entryIndex + localSymbolTable.entryCount) < localSymbolTable.entryIndex ) { diag.error("in '%s' malformed mach-o image: indirect symbol table local symbol count wraps", path); return false; } if ( (globalSymbolTable.entryCount > symbolTable.entryCount) || (globalSymbolTable.entryIndex > symbolTable.entryCount) ) { diag.error("in '%s' malformed mach-o image: indirect symbol table extern symbol count exceeds total symbols", path); return false; } if ( (globalSymbolTable.entryIndex + globalSymbolTable.entryCount) < globalSymbolTable.entryIndex ) { diag.error("in '%s' malformed mach-o image: indirect symbol table extern symbol count wraps", path); return false; } if ( (undefSymbolTable.entryCount > symbolTable.entryCount) || (undefSymbolTable.entryIndex > symbolTable.entryCount) ) { diag.error("in '%s' malformed mach-o image: indirect symbol table undefined symbol count exceeds total symbols", path); return false; } if ( (undefSymbolTable.entryIndex + undefSymbolTable.entryCount) < undefSymbolTable.entryIndex ) { diag.error("in '%s' malformed mach-o image: indirect symbol table undefined symbol count wraps", path); return false; } } } return true; } bool Layout::findExportedSymbol(Diagnostics& diag, const char* symbolName, bool weakImport, FoundSymbol& foundInfo) const { if ( this->linkedit.exportsTrie.hasValue() ) { // FIXME: Move all this to the ExportTrie class const uint8_t* trieStart = this->linkedit.exportsTrie.buffer; const uint8_t* trieEnd = trieStart + this->linkedit.exportsTrie.bufferSize; const uint8_t* node = dyld3::MachOFile::trieWalk(diag, trieStart, trieEnd, symbolName); if ( node == nullptr ) { // symbol not exported from this image. Seach any re-exported dylibs // FIXME: Implement this #if 0 __block unsigned depIndex = 0; __block bool foundInReExportedDylib = false; forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool& stop) { if ( isReExport && findDependent ) { if ( const MachOLoaded* depMH = findDependent(this, depIndex) ) { if ( depMH->findExportedSymbol(diag, symbolName, weakImport, foundInfo, findDependent) ) { stop = true; foundInReExportedDylib = true; } } } ++depIndex; }); return foundInReExportedDylib; #endif return false; } const uint8_t* p = node; const uint64_t flags = dyld3::MachOFile::read_uleb128(diag, p, trieEnd); if ( flags & EXPORT_SYMBOL_FLAGS_REEXPORT ) { // FIXME: Implement this #if 0 if ( !findDependent ) return false; // re-export from another dylib, lookup there const uint64_t ordinal = dyld3::MachOFile::read_uleb128(diag, p, trieEnd); const char* importedName = (char*)p; if ( importedName[0] == '\0' ) importedName = symbolName; if ( (ordinal == 0) || (ordinal > dependentDylibCount()) ) { diag.error("re-export ordinal %lld out of range for %s", ordinal, symbolName); return false; } uint32_t depIndex = (uint32_t)(ordinal-1); if ( const MachOLoaded* depMH = findDependent(this, depIndex) ) { return depMH->findExportedSymbol(diag, importedName, weakImport, foundInfo, findDependent); } else if (weakImport) { return false; } else { diag.error("dependent dylib %lld not found for re-exported symbol %s", ordinal, symbolName); return false; } #endif return false; } foundInfo.kind = FoundSymbol::Kind::headerOffset; foundInfo.isThreadLocal = false; foundInfo.isWeakDef = false; foundInfo.foundInDylib = this->mf; foundInfo.value = dyld3::MachOFile::read_uleb128(diag, p, trieEnd); foundInfo.resolverFuncOffset = 0; foundInfo.foundSymbolName = symbolName; if ( diag.hasError() ) return false; switch ( flags & EXPORT_SYMBOL_FLAGS_KIND_MASK ) { case EXPORT_SYMBOL_FLAGS_KIND_REGULAR: if ( flags & EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER ) { foundInfo.kind = FoundSymbol::Kind::headerOffset; foundInfo.resolverFuncOffset = (uint32_t)dyld3::MachOFile::read_uleb128(diag, p, trieEnd); } else { foundInfo.kind = FoundSymbol::Kind::headerOffset; } if ( flags & EXPORT_SYMBOL_FLAGS_WEAK_DEFINITION ) foundInfo.isWeakDef = true; break; case EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL: foundInfo.isThreadLocal = true; break; case EXPORT_SYMBOL_FLAGS_KIND_ABSOLUTE: foundInfo.kind = FoundSymbol::Kind::absolute; break; default: diag.error("unsupported exported symbol kind. flags=%llu at node offset=0x%0lX", flags, (long)(node-trieStart)); return false; } return true; } else { // this is an old binary (before macOS 10.6), scan the symbol table foundInfo.foundInDylib.reset(); SymbolTable symbolTable(*this); symbolTable.forEachGlobalSymbol(diag, ^(const char* aSymbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, bool& stop) { if ( strcmp(aSymbolName, symbolName) == 0 ) { foundInfo.kind = FoundSymbol::Kind::headerOffset; foundInfo.isThreadLocal = false; foundInfo.foundInDylib = this->mf; foundInfo.value = n_value - this->textUnslidVMAddr(); foundInfo.resolverFuncOffset = 0; foundInfo.foundSymbolName = symbolName; stop = true; } }); // FIXME: Implement this #if 0 if ( !foundInfo.foundInDylib.has_value() ) { // symbol not exported from this image. Search any re-exported dylibs __block unsigned depIndex = 0; forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool& stop) { if ( isReExport && findDependent ) { if ( const MachOLoaded* depMH = findDependent(this, depIndex) ) { if ( depMH->findExportedSymbol(diag, symbolName, weakImport, foundInfo, findDependent) ) { stop = true; } } } ++depIndex; }); } #endif return foundInfo.foundInDylib.has_value(); } } // MARK: --- Fixups methods --- Fixups::Fixups(const Layout& layout) : layout(layout) { } void Fixups::forEachBindTarget(Diagnostics& diag, bool allowLazyBinds, intptr_t slide, void (^handler)(const BindTargetInfo& info, bool& stop), void (^overrideHandler)(const BindTargetInfo& info, bool& stop)) const { if ( this->layout.mf->isPreload() ) return; if ( this->layout.mf->hasChainedFixups() ) this->forEachBindTarget_ChainedFixups(diag, handler); else if ( this->layout.mf->hasOpcodeFixups() ) this->forEachBindTarget_Opcodes(diag, allowLazyBinds, handler, overrideHandler); #if SUPPORT_CLASSIC_RELOCS else this->forEachBindTarget_Relocations(diag, slide, handler); #endif } void Fixups::forEachBindTarget_ChainedFixups(Diagnostics& diag, void (^handler)(const BindTargetInfo& info, bool& stop)) const { __block unsigned targetIndex = 0; this->forEachChainedFixupTarget(diag, ^(int libOrdinal, const char* symbolName, uint64_t addend, bool weakImport, bool& stop) { BindTargetInfo info; info.targetIndex = targetIndex; info.libOrdinal = libOrdinal; info.symbolName = symbolName; info.addend = addend; info.weakImport = weakImport; info.lazyBind = false; handler(info, stop); ++targetIndex; }); // The C++ spec says main executables can define non-weak functions which override weak-defs in dylibs // This happens automatically for anything bound at launch, but the dyld cache is pre-bound so we need // to patch any binds that are overridden by this non-weak in the main executable. if ( diag.noError() && this->layout.mf->isMainExecutable() && this->layout.mf->hasWeakDefs() ) { dyld3::MachOFile::forEachTreatAsWeakDef(^(const char* symbolName) { BindTargetInfo info; info.targetIndex = targetIndex; info.libOrdinal = BIND_SPECIAL_DYLIB_WEAK_LOOKUP; info.symbolName = symbolName; info.addend = 0; info.weakImport = false; info.lazyBind = false; bool stop = false; handler(info, stop); ++targetIndex; }); } } void Fixups::parseOrgArm64eChainedFixups(Diagnostics& diag, void (^targetCount)(uint32_t totalTargets, bool& stop), void (^addTarget)(bool libraryOrdinalSet, uint32_t dylibCount, int libOrdinal, uint8_t type, const char* symbolName, uint64_t addend, bool weakImport, bool& stop), void (^addChainStart)(uint32_t segmentIndex, bool segIndexSet, uint64_t segmentOffset, uint16_t format, bool& stop)) const { bool stop = false; const uint32_t dylibCount = this->layout.mf->dependentDylibCount(); if ( this->layout.linkedit.regularBindOpcodes.hasValue() ) { // process bind opcodes const uint8_t* p = this->layout.linkedit.regularBindOpcodes.buffer; const uint8_t* end = p + this->layout.linkedit.regularBindOpcodes.bufferSize; uint8_t type = 0; uint64_t segmentOffset = 0; uint8_t segmentIndex = 0; const char* symbolName = NULL; int libraryOrdinal = 0; bool segIndexSet = false; bool libraryOrdinalSet = false; uint64_t targetTableCount; uint64_t addend = 0; bool weakImport = false; while ( !stop && diag.noError() && (p < end) ) { uint8_t immediate = *p & BIND_IMMEDIATE_MASK; uint8_t opcode = *p & BIND_OPCODE_MASK; ++p; switch (opcode) { case BIND_OPCODE_DONE: stop = true; break; case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: libraryOrdinal = immediate; libraryOrdinalSet = true; break; case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: libraryOrdinal = (int)dyld3::MachOFile::read_uleb128(diag, p, end); libraryOrdinalSet = true; break; case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: // the special ordinals are negative numbers if ( immediate == 0 ) libraryOrdinal = 0; else { int8_t signExtended = BIND_OPCODE_MASK | immediate; libraryOrdinal = signExtended; } libraryOrdinalSet = true; break; case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: weakImport = ( (immediate & BIND_SYMBOL_FLAGS_WEAK_IMPORT) != 0 ); symbolName = (char*)p; while (*p != '\0') ++p; ++p; break; case BIND_OPCODE_SET_TYPE_IMM: type = immediate; break; case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: segmentIndex = immediate; segmentOffset = dyld3::MachOFile::read_uleb128(diag, p, end); segIndexSet = true; break; case BIND_OPCODE_SET_ADDEND_SLEB: addend = dyld3::MachOFile::read_sleb128(diag, p, end); break; case BIND_OPCODE_DO_BIND: if ( addTarget ) addTarget(libraryOrdinalSet, dylibCount, libraryOrdinal, type, symbolName, addend, weakImport, stop); break; case BIND_OPCODE_THREADED: switch (immediate) { case BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB: targetTableCount = dyld3::MachOFile::read_uleb128(diag, p, end); if ( targetTableCount > 65535 ) { diag.error("BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB size too large"); stop = true; } else { if ( targetCount ) targetCount((uint32_t)targetTableCount, stop); } break; case BIND_SUBOPCODE_THREADED_APPLY: if ( addChainStart ) addChainStart(segmentIndex, segIndexSet, segmentOffset, DYLD_CHAINED_PTR_ARM64E, stop); break; default: diag.error("bad BIND_OPCODE_THREADED sub-opcode 0x%02X", immediate); } break; default: diag.error("bad bind opcode 0x%02X", immediate); } } if ( diag.hasError() ) return; } } void Fixups::forEachChainedFixupTarget(Diagnostics& diag, void (^callback)(int libOrdinal, const char* symbolName, uint64_t addend, bool weakImport, bool& stop)) const { if ( this->layout.linkedit.regularBindOpcodes.hasValue() ) { parseOrgArm64eChainedFixups(diag, nullptr, ^(bool libraryOrdinalSet, uint32_t dylibCount, int libOrdinal, uint8_t type, const char* symbolName, uint64_t fixAddend, bool weakImport, bool& stopChain) { callback(libOrdinal, symbolName, fixAddend, weakImport, stopChain); }, nullptr); } else if ( this->layout.linkedit.chainedFixups.hasValue() ) { const dyld_chained_fixups_header* header = (dyld_chained_fixups_header*)this->layout.linkedit.chainedFixups.buffer; dyld3::MachOFile::forEachChainedFixupTarget(diag, header, this->layout.linkedit.chainedFixups.cmd, callback); } } #if (BUILDING_DYLD || BUILDING_LIBDYLD) && !__arm64e__ #define SUPPORT_OLD_ARM64E_FORMAT 0 #else #define SUPPORT_OLD_ARM64E_FORMAT 1 #endif // find dyld_chained_starts_in_image* in image // if old arm64e binary, synthesize dyld_chained_starts_in_image* void Fixups::withThreadedRebaseAsChainStarts(Diagnostics& diag, void (^callback)(const dyld_chained_fixups_header* header, uint64_t fixupsSize)) const { #if SUPPORT_OLD_ARM64E_FORMAT // don't want this code in non-arm64e dyld because it causes a stack protector which dereferences a GOT pointer before GOT is set up // old arm64e binary, create a dyld_chained_starts_in_image for caller uint64_t baseAddress = this->layout.mf->preferredLoadAddress(); uint64_t imagePageCount = this->layout.mf->mappedSize()/0x4000; size_t bufferSize = this->layout.linkedit.regularBindOpcodes.bufferSize + (size_t)imagePageCount*sizeof(uint16_t) + 512; BLOCK_ACCCESSIBLE_ARRAY(uint8_t, buffer, bufferSize); uint8_t* bufferEnd = &buffer[bufferSize]; dyld_chained_fixups_header* header = (dyld_chained_fixups_header*)buffer; header->fixups_version = 0; header->starts_offset = sizeof(dyld_chained_fixups_header); header->imports_offset = 0; header->symbols_offset = 0; header->imports_count = 0; header->imports_format = 0; header->symbols_format = 0; dyld_chained_starts_in_image* starts = (dyld_chained_starts_in_image*)(dyld_chained_starts_in_image*)((uint8_t*)header + header->starts_offset); starts->seg_count = (uint32_t)this->layout.segments.size(); for (uint32_t i=0; i < starts->seg_count; ++i) starts->seg_info_offset[i] = 0; __block uint8_t curSegIndex = 0; __block dyld_chained_starts_in_segment* curSeg = (dyld_chained_starts_in_segment*)(&(starts->seg_info_offset[starts->seg_count])); parseOrgArm64eChainedFixups(diag, nullptr, nullptr, ^(uint32_t segmentIndex, bool segIndexSet, uint64_t segmentOffset, uint16_t format, bool& stop) { uint32_t pageIndex = (uint32_t)(segmentOffset/0x1000); if ( segmentIndex != curSegIndex ) { if ( curSegIndex == 0 ) { starts->seg_info_offset[segmentIndex] = (uint32_t)((uint8_t*)curSeg - (uint8_t*)starts); } else { starts->seg_info_offset[segmentIndex] = (uint32_t)((uint8_t*)(&curSeg->page_start[curSeg->page_count]) - (uint8_t*)starts); curSeg = (dyld_chained_starts_in_segment*)((uint8_t*)starts+starts->seg_info_offset[segmentIndex]); assert((uint8_t*)curSeg < bufferEnd); } curSeg->page_count = 0; curSegIndex = segmentIndex; } while ( curSeg->page_count != pageIndex ) { assert((uint8_t*)(&curSeg->page_start[curSeg->page_count]) < bufferEnd); curSeg->page_start[curSeg->page_count] = 0xFFFF; curSeg->page_count++; } curSeg->size = (uint32_t)((uint8_t*)(&curSeg->page_start[pageIndex]) - (uint8_t*)curSeg); curSeg->page_size = 0x1000; // old arm64e encoding used 4KB pages curSeg->pointer_format = DYLD_CHAINED_PTR_ARM64E; curSeg->segment_offset = this->layout.segments[segmentIndex].vmAddr - baseAddress; curSeg->max_valid_pointer = 0; curSeg->page_count = pageIndex+1; assert((uint8_t*)(&curSeg->page_start[pageIndex]) < bufferEnd); curSeg->page_start[pageIndex] = segmentOffset & 0xFFF; //fprintf(stderr, "segment_offset=0x%llX, vmAddr=0x%llX\n", curSeg->segment_offset, segments[segmentIndex].vmAddr ); //printf("segIndex=%d, segOffset=0x%08llX, page_start[%d]=0x%04X, page_start[%d]=0x%04X\n", // segmentIndex, segmentOffset, pageIndex, curSeg->page_start[pageIndex], pageIndex-1, pageIndex ? curSeg->page_start[pageIndex-1] : 0); }); callback(header, (uint64_t)bufferSize); #endif } const dyld_chained_fixups_header* Fixups::chainedFixupsHeader() const { if ( this->layout.linkedit.chainedFixups.hasValue() ) { // find dyld_chained_starts_in_image from dyld_chained_fixups_header return (dyld_chained_fixups_header*)this->layout.linkedit.chainedFixups.buffer; } return nullptr; } // find dyld_chained_starts_in_image* in image // if old arm64e binary, synthesize dyld_chained_starts_in_image* void Fixups::withChainStarts(Diagnostics& diag, void (^callback)(const dyld_chained_starts_in_image*)) const { if ( const dyld_chained_fixups_header* chainHeader = this->chainedFixupsHeader() ) { // find dyld_chained_starts_in_image from dyld_chained_fixups_header callback((dyld_chained_starts_in_image*)((uint8_t*)chainHeader + chainHeader->starts_offset)); } #if SUPPORT_OLD_ARM64E_FORMAT // don't want this code in non-arm64e dyld because it causes a stack protector which dereferences a GOT pointer before GOT is set up else if ( this->layout.linkedit.regularBindOpcodes.hasValue() && (this->layout.mf->cputype == CPU_TYPE_ARM64) && (this->layout.mf->maskedCpuSubtype() == CPU_SUBTYPE_ARM64E) ) { // old arm64e binary, create a dyld_chained_starts_in_image for caller this->withThreadedRebaseAsChainStarts(diag, ^(const dyld_chained_fixups_header* header, uint64_t fixupsSize) { callback((dyld_chained_starts_in_image*)((uint8_t*)header + header->starts_offset)); }); } #endif else { diag.error("image does not use chained fixups"); } } void Fixups::forEachFixupInAllChains(Diagnostics& diag, const dyld_chained_starts_in_image* starts, bool notifyNonPointers, void (^handler)(ChainedFixupPointerOnDisk* fixupLocation, uint64_t fixupSegmentOffset, const dyld_chained_starts_in_segment* segInfo, bool& stop)) const { bool stopped = false; for (uint32_t segIndex=0; segIndex < starts->seg_count && !stopped; ++segIndex) { if ( starts->seg_info_offset[segIndex] == 0 ) continue; const dyld_chained_starts_in_segment* segInfo = (dyld_chained_starts_in_segment*)((uint8_t*)starts + starts->seg_info_offset[segIndex]); auto adaptor = ^(ChainedFixupPointerOnDisk* fixupLocation, uint64_t fixupSegmentOffset, bool& stop) { handler(fixupLocation, fixupSegmentOffset, segInfo, stop); }; forEachFixupInSegmentChains(diag, segInfo, segIndex, notifyNonPointers, adaptor); } } void Fixups::forEachFixupInSegmentChains(Diagnostics& diag, const dyld_chained_starts_in_segment* segInfo, uint32_t segIndex, bool notifyNonPointers, void (^handler)(ChainedFixupPointerOnDisk* fixupLocation, uint64_t fixupSegmentOffset, bool& stop)) const { const uint8_t* segmentBuffer = this->layout.segments[segIndex].buffer; auto adaptor = ^(ChainedFixupPointerOnDisk* fixupLocation, bool& stop) { uint64_t fixupSegmentOffset = (uint64_t)fixupLocation - (uint64_t)segmentBuffer; handler(fixupLocation, fixupSegmentOffset, stop); }; bool stopped = false; for (uint32_t pageIndex=0; pageIndex < segInfo->page_count && !stopped; ++pageIndex) { uint16_t offsetInPage = segInfo->page_start[pageIndex]; if ( offsetInPage == DYLD_CHAINED_PTR_START_NONE ) continue; const uint8_t* pageContentStart = segmentBuffer + (pageIndex * segInfo->page_size); if ( offsetInPage & DYLD_CHAINED_PTR_START_MULTI ) { // 32-bit chains which may need multiple starts per page uint32_t overflowIndex = offsetInPage & ~DYLD_CHAINED_PTR_START_MULTI; bool chainEnd = false; while (!stopped && !chainEnd) { chainEnd = (segInfo->page_start[overflowIndex] & DYLD_CHAINED_PTR_START_LAST); offsetInPage = (segInfo->page_start[overflowIndex] & ~DYLD_CHAINED_PTR_START_LAST); ChainedFixupPointerOnDisk* chain = (ChainedFixupPointerOnDisk*)(pageContentStart+offsetInPage); stopped = dyld3::MachOFile::walkChain(diag, chain, segInfo->pointer_format, notifyNonPointers, segInfo->max_valid_pointer, adaptor); ++overflowIndex; } } else { // one chain per page ChainedFixupPointerOnDisk* chain = (ChainedFixupPointerOnDisk*)(pageContentStart+offsetInPage); stopped = dyld3::MachOFile::walkChain(diag, chain, segInfo->pointer_format, notifyNonPointers, segInfo->max_valid_pointer, adaptor); } } } void Fixups::forEachFixupChainSegment(Diagnostics& diag, const dyld_chained_starts_in_image* starts, void (^handler)(const dyld_chained_starts_in_segment* segInfo, uint32_t segIndex, bool& stop)) { bool stopped = false; for (uint32_t segIndex=0; segIndex < starts->seg_count && !stopped; ++segIndex) { if ( starts->seg_info_offset[segIndex] == 0 ) continue; const dyld_chained_starts_in_segment* segInfo = (dyld_chained_starts_in_segment*)((uint8_t*)starts + starts->seg_info_offset[segIndex]); handler(segInfo, segIndex, stopped); } } uint16_t Fixups::chainedPointerFormat() const { if ( const dyld_chained_fixups_header* chainHeader = this->chainedFixupsHeader() ) { // get pointer format from chain info struct in LINKEDIT return dyld3::MachOFile::chainedPointerFormat(chainHeader); } assert(this->layout.mf->cputype == CPU_TYPE_ARM64 && (this->layout.mf->maskedCpuSubtype() == CPU_SUBTYPE_ARM64E) && "chainedPointerFormat() called on non-chained binary"); return DYLD_CHAINED_PTR_ARM64E; } // walk through all binds, unifying weak, lazy, and regular binds void Fixups::forEachBindUnified_Opcodes(Diagnostics& diag, bool allowLazyBinds, void (^handler)(uint64_t runtimeOffset, uint32_t segmentIndex, const BindTargetInfo& targetInfo, bool& stop), void (^overrideHandler)(uint64_t runtimeOffset, uint32_t segmentIndex, const BindTargetInfo& targetInfo, bool& stop)) const { { __block unsigned targetIndex = 0; __block BindTargetInfo targetInfo; BindDetailedHandler binder = ^(const char* opcodeName, bool segIndexSet, bool libraryOrdinalSet, uint32_t dylibCount, int libOrdinal, uint32_t pointerSize, uint32_t segmentIndex, uint64_t segmentOffset, uint8_t type, const char* symbolName, bool weakImport, bool lazyBind, uint64_t addend, bool targetOrAddendChanged, bool& stop) { uint64_t bindVmOffset = this->layout.segments[segmentIndex].vmAddr + segmentOffset; uint64_t runtimeOffset = bindVmOffset - this->layout.textUnslidVMAddr(); if ( targetOrAddendChanged ) { targetInfo.targetIndex = targetIndex++; targetInfo.libOrdinal = libOrdinal; targetInfo.symbolName = symbolName; targetInfo.addend = addend; targetInfo.weakImport = weakImport; targetInfo.lazyBind = lazyBind && allowLazyBinds; } handler(runtimeOffset, segmentIndex, targetInfo, stop); }; bool stopped = this->forEachBind_OpcodesRegular(diag, binder); if ( stopped ) return; stopped = this->forEachBind_OpcodesLazy(diag, binder); if ( stopped ) return; } // Opcode based weak-binds effectively override other binds/rebases. Process them last // To match dyld2, they are allowed to fail to find a target, in which case the normal rebase/bind will // not be overridden. { __block unsigned weakTargetIndex = 0; __block BindTargetInfo weakTargetInfo; BindDetailedHandler weakBinder = ^(const char* opcodeName, bool segIndexSet, bool libraryOrdinalSet, uint32_t dylibCount, int libOrdinal, uint32_t pointerSize, uint32_t segmentIndex, uint64_t segmentOffset, uint8_t type, const char* symbolName, bool weakImport, bool lazyBind, uint64_t addend, bool targetOrAddendChanged, bool& stop) { uint64_t bindVmOffset = this->layout.segments[segmentIndex].vmAddr + segmentOffset; uint64_t runtimeOffset = bindVmOffset - this->layout.textUnslidVMAddr(); if ( (symbolName != weakTargetInfo.symbolName) || (strcmp(symbolName, weakTargetInfo.symbolName) != 0) || (weakTargetInfo.addend != addend) ) { weakTargetInfo.targetIndex = weakTargetIndex++; weakTargetInfo.libOrdinal = BIND_SPECIAL_DYLIB_WEAK_LOOKUP; weakTargetInfo.symbolName = symbolName; weakTargetInfo.addend = addend; weakTargetInfo.weakImport = false; weakTargetInfo.lazyBind = false; } overrideHandler(runtimeOffset, segmentIndex, weakTargetInfo, stop); }; auto strongHandler = ^(const char* strongName) { }; this->forEachBind_OpcodesWeak(diag, weakBinder, strongHandler); } } void Fixups::forEachBindTarget_Opcodes(Diagnostics& diag, bool allowLazyBinds, void (^handler)(const BindTargetInfo& info, bool& stop), void (^overrideHandler)(const BindTargetInfo& info, bool& stop)) const { __block unsigned lastTargetIndex = -1; __block unsigned lastWeakBindTargetIndex = -1; this->forEachBindUnified_Opcodes(diag, allowLazyBinds, ^(uint64_t runtimeOffset, uint32_t segmentIndex, const BindTargetInfo& targetInfo, bool& stop) { // Regular/lazy binds if ( lastTargetIndex != targetInfo.targetIndex) { handler(targetInfo, stop); lastTargetIndex = targetInfo.targetIndex; } }, ^(uint64_t runtimeOffset, uint32_t segmentIndex, const BindTargetInfo& targetInfo, bool& stop) { // Weak binds if ( lastWeakBindTargetIndex != targetInfo.targetIndex) { overrideHandler(targetInfo, stop); lastWeakBindTargetIndex = targetInfo.targetIndex; } }); } bool Fixups::forEachBind_OpcodesLazy(Diagnostics& diag, BindDetailedHandler handler) const { if ( !this->layout.linkedit.lazyBindOpcodes.hasValue() ) return false; uint32_t lazyDoneCount = 0; uint32_t lazyBindCount = 0; const uint32_t ptrSize = this->layout.mf->pointerSize(); bool stop = false; const uint32_t dylibCount = this->layout.mf->dependentDylibCount(); const uint8_t* p = this->layout.linkedit.lazyBindOpcodes.buffer; const uint8_t* end = p + this->layout.linkedit.lazyBindOpcodes.bufferSize; uint8_t type = BIND_TYPE_POINTER; uint64_t segmentOffset = 0; uint8_t segmentIndex = 0; const char* symbolName = NULL; int libraryOrdinal = 0; bool segIndexSet = false; bool libraryOrdinalSet = false; int64_t addend = 0; bool weakImport = false; while ( !stop && diag.noError() && (p < end) ) { uint8_t immediate = *p & BIND_IMMEDIATE_MASK; uint8_t opcode = *p & BIND_OPCODE_MASK; ++p; switch (opcode) { case BIND_OPCODE_DONE: // this opcode marks the end of each lazy pointer binding ++lazyDoneCount; break; case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: libraryOrdinal = immediate; libraryOrdinalSet = true; break; case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: libraryOrdinal = (int)dyld3::MachOFile::read_uleb128(diag, p, end); libraryOrdinalSet = true; break; case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: // the special ordinals are negative numbers if ( immediate == 0 ) libraryOrdinal = 0; else { int8_t signExtended = BIND_OPCODE_MASK | immediate; libraryOrdinal = signExtended; } libraryOrdinalSet = true; break; case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: weakImport = ( (immediate & BIND_SYMBOL_FLAGS_WEAK_IMPORT) != 0 ); symbolName = (char*)p; while (*p != '\0') ++p; ++p; break; case BIND_OPCODE_SET_ADDEND_SLEB: addend = dyld3::MachOFile::read_sleb128(diag, p, end); break; case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: segmentIndex = immediate; segmentOffset = dyld3::MachOFile::read_uleb128(diag, p, end); segIndexSet = true; break; case BIND_OPCODE_DO_BIND: handler("BIND_OPCODE_DO_BIND", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, true, addend, true, stop); segmentOffset += ptrSize; ++lazyBindCount; break; case BIND_OPCODE_SET_TYPE_IMM: case BIND_OPCODE_ADD_ADDR_ULEB: case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB: case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: default: diag.error("bad lazy bind opcode 0x%02X", opcode); break; } } if ( lazyDoneCount > lazyBindCount+7 ) { // diag.error("lazy bind opcodes missing binds"); } return stop; } bool Fixups::forEachBind_OpcodesWeak(Diagnostics& diag, BindDetailedHandler handler, void (^strongHandler)(const char* symbolName)) const { if ( !this->layout.linkedit.weakBindOpcodes.hasValue() ) return false; const uint32_t ptrSize = this->layout.mf->pointerSize(); bool stop = false; const uint32_t dylibCount = this->layout.mf->dependentDylibCount(); const uint8_t* p = this->layout.linkedit.weakBindOpcodes.buffer; const uint8_t* end = p + this->layout.linkedit.weakBindOpcodes.bufferSize; uint8_t type = BIND_TYPE_POINTER; uint64_t segmentOffset = 0; uint8_t segmentIndex = 0; const char* symbolName = NULL; int libraryOrdinal = BIND_SPECIAL_DYLIB_WEAK_LOOKUP; bool segIndexSet = false; bool libraryOrdinalSet = true; int64_t addend = 0; bool weakImport = false; bool targetOrAddendChanged = true; bool done = false; uint64_t count; uint64_t skip; while ( !stop && diag.noError() && (p < end) && !done ) { uint8_t immediate = *p & BIND_IMMEDIATE_MASK; uint8_t opcode = *p & BIND_OPCODE_MASK; ++p; switch (opcode) { case BIND_OPCODE_DONE: done = true; break; case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: diag.error("unexpected dylib ordinal in weak_bind"); break; case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: weakImport = ( (immediate & BIND_SYMBOL_FLAGS_WEAK_IMPORT) != 0 ); symbolName = (char*)p; while (*p != '\0') ++p; ++p; if ( immediate & BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION ) { strongHandler(symbolName); } targetOrAddendChanged = true; break; case BIND_OPCODE_SET_TYPE_IMM: type = immediate; break; case BIND_OPCODE_SET_ADDEND_SLEB: addend = dyld3::MachOFile::read_sleb128(diag, p, end); targetOrAddendChanged = true; break; case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: segmentIndex = immediate; segmentOffset = dyld3::MachOFile::read_uleb128(diag, p, end); segIndexSet = true; break; case BIND_OPCODE_ADD_ADDR_ULEB: segmentOffset += dyld3::MachOFile::read_uleb128(diag, p, end); break; case BIND_OPCODE_DO_BIND: handler("BIND_OPCODE_DO_BIND", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); segmentOffset += ptrSize; targetOrAddendChanged = false; break; case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB: handler("BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); segmentOffset += dyld3::MachOFile::read_uleb128(diag, p, end) + ptrSize; targetOrAddendChanged = false; break; case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: handler("BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); segmentOffset += immediate*ptrSize + ptrSize; targetOrAddendChanged = false; break; case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: count = dyld3::MachOFile::read_uleb128(diag, p, end); skip = dyld3::MachOFile::read_uleb128(diag, p, end); for (uint32_t i=0; i < count; ++i) { handler("BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); segmentOffset += skip + ptrSize; targetOrAddendChanged = false; if ( stop ) break; } break; default: diag.error("bad bind opcode 0x%02X", *p); } } return stop; } bool Fixups::forEachBind_OpcodesRegular(Diagnostics& diag, BindDetailedHandler handler) const { if ( !this->layout.linkedit.regularBindOpcodes.hasValue() ) return false; const uint32_t ptrSize = this->layout.mf->pointerSize(); bool stop = false; const uint32_t dylibCount = this->layout.mf->dependentDylibCount(); const uint8_t* p = this->layout.linkedit.regularBindOpcodes.buffer; const uint8_t* end = p + this->layout.linkedit.regularBindOpcodes.bufferSize; uint8_t type = 0; uint64_t segmentOffset = 0; uint8_t segmentIndex = 0; const char* symbolName = NULL; int libraryOrdinal = 0; bool segIndexSet = false; bool libraryOrdinalSet = false; bool targetOrAddendChanged = false; bool done = false; int64_t addend = 0; uint64_t count; uint64_t skip; bool weakImport = false; while ( !stop && diag.noError() && (p < end) && !done ) { uint8_t immediate = *p & BIND_IMMEDIATE_MASK; uint8_t opcode = *p & BIND_OPCODE_MASK; ++p; switch (opcode) { case BIND_OPCODE_DONE: done = true; break; case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM: libraryOrdinal = immediate; libraryOrdinalSet = true; break; case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB: libraryOrdinal = (int)dyld3::MachOFile::read_uleb128(diag, p, end); libraryOrdinalSet = true; break; case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM: // the special ordinals are negative numbers if ( immediate == 0 ) libraryOrdinal = 0; else { int8_t signExtended = BIND_OPCODE_MASK | immediate; libraryOrdinal = signExtended; } libraryOrdinalSet = true; break; case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM: weakImport = ( (immediate & BIND_SYMBOL_FLAGS_WEAK_IMPORT) != 0 ); symbolName = (char*)p; while (*p != '\0') ++p; ++p; targetOrAddendChanged = true; break; case BIND_OPCODE_SET_TYPE_IMM: type = immediate; break; case BIND_OPCODE_SET_ADDEND_SLEB: addend = dyld3::MachOFile::read_sleb128(diag, p, end); targetOrAddendChanged = true; break; case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: segmentIndex = immediate; segmentOffset = dyld3::MachOFile::read_uleb128(diag, p, end); segIndexSet = true; break; case BIND_OPCODE_ADD_ADDR_ULEB: segmentOffset += dyld3::MachOFile::read_uleb128(diag, p, end); break; case BIND_OPCODE_DO_BIND: handler("BIND_OPCODE_DO_BIND", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); segmentOffset += ptrSize; targetOrAddendChanged = false; break; case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB: handler("BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); segmentOffset += dyld3::MachOFile::read_uleb128(diag, p, end) + ptrSize; targetOrAddendChanged = false; break; case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED: handler("BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); segmentOffset += immediate*ptrSize + ptrSize; targetOrAddendChanged = false; break; case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB: count = dyld3::MachOFile::read_uleb128(diag, p, end); skip = dyld3::MachOFile::read_uleb128(diag, p, end); for (uint32_t i=0; i < count; ++i) { handler("BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB", segIndexSet, libraryOrdinalSet, dylibCount, libraryOrdinal, ptrSize, segmentIndex, segmentOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); segmentOffset += skip + ptrSize; targetOrAddendChanged = false; if ( stop ) break; } break; default: diag.error("bad bind opcode 0x%02X", *p); } } return stop; } void Fixups::forEachBindLocation_Opcodes(Diagnostics& diag, void (^handler)(uint64_t runtimeOffset, uint32_t segmentIndex, unsigned targetIndex, bool& stop), void (^overrideHandler)(uint64_t runtimeOffset, uint32_t segmentIndex, unsigned overrideBindTargetIndex, bool& stop)) const { this->forEachBindUnified_Opcodes(diag, false, ^(uint64_t runtimeOffset, uint32_t segmentIndex, const BindTargetInfo& targetInfo, bool& stop) { handler(runtimeOffset, segmentIndex, targetInfo.targetIndex, stop); }, ^(uint64_t runtimeOffset, uint32_t segmentIndex, const BindTargetInfo& weakTargetInfo, bool& stop) { overrideHandler(runtimeOffset, segmentIndex, weakTargetInfo.targetIndex, stop); }); } void Fixups::forEachBindLocation_Relocations(Diagnostics& diag, void (^handler)(uint64_t runtimeOffset, unsigned targetIndex, bool& stop)) const { // As we don't need the private externs workaround, we also don't need a slide here bool supportPrivateExternsWorkaround = false; intptr_t unusedSlide = 0; __block int targetIndex = -1; this->forEachBind_Relocations(diag, supportPrivateExternsWorkaround, unusedSlide, ^(const char* opcodeName, bool segIndexSet, bool libraryOrdinalSet, uint32_t dylibCount, int libOrdinal, uint32_t pointerSize, uint32_t segmentIndex, uint64_t segmentOffset, uint8_t type, const char* symbolName, bool weakImport, bool lazyBind, uint64_t addend, bool targetOrAddendChanged, bool& stop) { if ( targetOrAddendChanged ) ++targetIndex; uint64_t bindVMAddr = this->layout.segments[segmentIndex].vmAddr + segmentOffset; uint64_t runtimeOffset = bindVMAddr - this->layout.textUnslidVMAddr(); handler(runtimeOffset, targetIndex, stop); }); } // old binary, walk external relocations and indirect symbol table void Fixups::forEachBindTarget_Relocations(Diagnostics& diag, intptr_t slide, void (^handler)(const BindTargetInfo& info, bool& stop)) const { __block unsigned targetIndex = 0; this->forEachBind_Relocations(diag, true, slide, ^(const char* opcodeName, bool segIndexSet, bool libraryOrdinalSet, uint32_t dylibCount, int libOrdinal, uint32_t pointerSize, uint32_t segmentIndex, uint64_t segmentOffset, uint8_t type, const char* symbolName, bool weakImport, bool lazyBind, uint64_t addend, bool targetOrAddendChanged, bool& stop) { if ( targetOrAddendChanged ) { BindTargetInfo info; info.targetIndex = targetIndex; info.libOrdinal = libOrdinal; info.symbolName = symbolName; info.addend = addend; info.weakImport = weakImport; info.lazyBind = lazyBind; handler(info, stop); ++targetIndex; } }); } bool Fixups::forEachRebaseLocation_Opcodes(Diagnostics& diag, void (^handler)(uint64_t runtimeOffset, uint32_t segmentIndex, bool& stop)) const { return this->forEachRebase_Opcodes(diag, ^(const char* opcodeName, bool segIndexSet, uint32_t pointerSize, uint8_t segmentIndex, uint64_t segmentOffset, Rebase kind, bool& stop) { uint64_t rebaseVMAddr = this->layout.segments[segmentIndex].vmAddr + segmentOffset; uint64_t runtimeOffset = rebaseVMAddr - this->layout.textUnslidVMAddr(); handler(runtimeOffset, segmentIndex, stop); }); } void Fixups::forEachRebase(Diagnostics& diag, void (^callback)(uint64_t runtimeOffset, uint64_t rebasedValue, bool& stop)) const { if ( !this->layout.linkedit.rebaseOpcodes.hasValue() ) return; const bool is64 = this->layout.mf->is64(); this->forEachRebase_Opcodes(diag, ^(const char* opcodeName, bool segIndexSet, uint32_t pointerSize, uint8_t segmentIndex, uint64_t segmentOffset, Rebase kind, bool& stop) { uint64_t rebaseVMAddr = this->layout.segments[segmentIndex].vmAddr + segmentOffset; uint64_t runtimeOffset = rebaseVMAddr - this->layout.textUnslidVMAddr(); const uint8_t* fixupLoc = this->layout.segments[segmentIndex].buffer + segmentOffset; uint64_t targetVMAddr = 0; if ( is64 ) { targetVMAddr = *(uint64_t*)fixupLoc; } else { targetVMAddr = *(uint32_t*)fixupLoc; } callback(runtimeOffset, targetVMAddr, stop); }); } bool Fixups::forEachRebase_Opcodes(Diagnostics& diag, RebaseDetailHandler handler) const { const bool is64 = this->layout.mf->is64(); const Rebase pointerRebaseKind = is64 ? Rebase::pointer64 : Rebase::pointer32; assert(this->layout.linkedit.rebaseOpcodes.hasValue()); const uint8_t* const start = this->layout.linkedit.rebaseOpcodes.buffer; const uint8_t* const end = start + this->layout.linkedit.rebaseOpcodes.bufferSize; const uint8_t* p = start; const uint32_t ptrSize = this->layout.mf->pointerSize(); Rebase kind = Rebase::unknown; int segIndex = 0; uint64_t segOffset = 0; uint64_t count; uint64_t skip; bool segIndexSet = false; bool stop = false; while ( !stop && diag.noError() && (p < end) ) { uint8_t immediate = *p & REBASE_IMMEDIATE_MASK; uint8_t opcode = *p & REBASE_OPCODE_MASK; ++p; switch (opcode) { case REBASE_OPCODE_DONE: // Allow some padding, in case rebases were somehow aligned to 16-bytes in size if ( (end - p) > 15 ) diag.error("rebase opcodes terminated early at offset %d of %d", (int)(p-start), (int)(end-start)); stop = true; break; case REBASE_OPCODE_SET_TYPE_IMM: switch ( immediate ) { case REBASE_TYPE_POINTER: kind = pointerRebaseKind; break; case REBASE_TYPE_TEXT_ABSOLUTE32: kind = Rebase::textAbsolute32; break; case REBASE_TYPE_TEXT_PCREL32: kind = Rebase::textPCrel32; break; default: kind = Rebase::unknown; break; } break; case REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB: segIndex = immediate; segOffset = dyld3::MachOFile::read_uleb128(diag, p, end); segIndexSet = true; break; case REBASE_OPCODE_ADD_ADDR_ULEB: segOffset += dyld3::MachOFile::read_uleb128(diag, p, end); break; case REBASE_OPCODE_ADD_ADDR_IMM_SCALED: segOffset += immediate*ptrSize; break; case REBASE_OPCODE_DO_REBASE_IMM_TIMES: for (int i=0; i < immediate; ++i) { handler("REBASE_OPCODE_DO_REBASE_IMM_TIMES", segIndexSet, ptrSize, segIndex, segOffset, kind, stop); segOffset += ptrSize; if ( stop ) break; } break; case REBASE_OPCODE_DO_REBASE_ULEB_TIMES: count = dyld3::MachOFile::read_uleb128(diag, p, end); for (uint32_t i=0; i < count; ++i) { handler("REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB", segIndexSet, ptrSize, segIndex, segOffset, kind, stop); segOffset += ptrSize; if ( stop ) break; } break; case REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB: handler("REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB", segIndexSet, ptrSize, segIndex, segOffset, kind, stop); segOffset += dyld3::MachOFile::read_uleb128(diag, p, end) + ptrSize; break; case REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB: count = dyld3::MachOFile::read_uleb128(diag, p, end); if ( diag.hasError() ) break; skip = dyld3::MachOFile::read_uleb128(diag, p, end); for (uint32_t i=0; i < count; ++i) { handler("REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB", segIndexSet, ptrSize, segIndex, segOffset, kind, stop); segOffset += skip + ptrSize; if ( stop ) break; } break; default: diag.error("unknown rebase opcode 0x%02X", opcode); } } return stop; } bool Fixups::forEachRebaseLocation_Relocations(Diagnostics& diag, void (^handler)(uint64_t runtimeOffset, uint32_t segmentIndex, bool& stop)) const { return this->forEachRebase_Relocations(diag, ^(const char* opcodeName, bool segIndexSet, uint32_t pointerSize, uint8_t segmentIndex, uint64_t segmentOffset, Rebase kind, bool& stop) { uint64_t rebaseVmOffset = this->layout.segments[segmentIndex].vmAddr + segmentOffset; uint64_t runtimeOffset = rebaseVmOffset - this->layout.textUnslidVMAddr(); handler(runtimeOffset, segmentIndex, stop); }); } #if SUPPORT_CLASSIC_RELOCS // relocs are normally sorted, we don't want to use qsort because it may switch to mergesort which uses malloc static void sortRelocations(dyld3::Array<relocation_info>& relocs) { // The kernel linker has malloc, and old-style relocations are extremely common. So use qsort #if BUILDING_APP_CACHE_UTIL || BUILDING_DYLDINFO ::qsort(&relocs[0], (size_t)relocs.count(), sizeof(relocation_info), [](const void* l, const void* r) -> int { if ( ((relocation_info*)l)->r_address < ((relocation_info*)r)->r_address ) return -1; else return 1; }); #else uint64_t count = relocs.count(); for (uint64_t i=0; i < count-1; ++i) { bool done = true; for (uint64_t j=0; j < count-i-1; ++j) { if ( relocs[j].r_address > relocs[j+1].r_address ) { relocation_info temp = relocs[j]; relocs[j] = relocs[j+1]; relocs[j+1] = temp; done = false; } } if ( done ) break; } #endif } bool Fixups::forEachRebase_Relocations(Diagnostics& diag, RebaseDetailHandler handler) const { // old binary, walk relocations bool is64Bit = this->layout.mf->is64(); const uint8_t ptrSize = this->layout.mf->pointerSize(); const uint64_t relocsStartAddress = localRelocBaseAddress(); const relocation_info* const relocsStart = (const relocation_info*)this->layout.linkedit.localRelocs.buffer; const relocation_info* const relocsEnd = &relocsStart[this->layout.linkedit.localRelocs.entryCount]; const uint8_t relocSize = (is64Bit ? 3 : 2); bool stop = false; STACK_ALLOC_OVERFLOW_SAFE_ARRAY(relocation_info, relocs, 2048); for (const relocation_info* reloc=relocsStart; (reloc < relocsEnd) && !stop; ++reloc) { if ( reloc->r_length != relocSize ) { bool shouldEmitError = true; #if BUILDING_APP_CACHE_UTIL || BUILDING_DYLDINFO if ( this->layout.mf->usesClassicRelocationsInKernelCollection() && (reloc->r_length == 2) && (relocSize == 3) ) shouldEmitError = false; #endif if ( shouldEmitError ) { diag.error("local relocation has wrong r_length"); break; } } if ( reloc->r_type != 0 ) { // 0 == X86_64_RELOC_UNSIGNED == GENERIC_RELOC_VANILLA == ARM64_RELOC_UNSIGNED diag.error("local relocation has wrong r_type"); break; } relocs.push_back(*reloc); } if ( !relocs.empty() ) { sortRelocations(relocs); for (relocation_info reloc : relocs) { uint32_t addrOff = reloc.r_address; uint32_t segIndex = 0; uint64_t segOffset = 0; uint64_t addr = 0; #if BUILDING_APP_CACHE_UTIL || BUILDING_DYLDINFO // xnu for x86_64 has __HIB mapped before __DATA, so offsets appear to be // negative if ( this->layout.mf->isStaticExecutable() || this->layout.mf->isFileSet() ) { addr = relocsStartAddress + (int32_t)addrOff; } else { addr = relocsStartAddress + addrOff; } #else addr = relocsStartAddress + addrOff; #endif if ( segIndexAndOffsetForAddress(addr, segIndex, segOffset) ) { Rebase kind = (reloc.r_length == 2) ? Rebase::pointer32 : Rebase::pointer64; if ( this->layout.mf->cputype == CPU_TYPE_I386 ) { if ( this->layout.segments[segIndex].executable() ) kind = Rebase::textAbsolute32; } handler("local relocation", true, ptrSize, segIndex, segOffset, kind, stop); } else { diag.error("local relocation has out of range r_address"); break; } } } // then process indirect symbols const Rebase pointerRebaseKind = is64Bit ? Rebase::pointer64 : Rebase::pointer32; intptr_t unusedSlide = 0; forEachIndirectPointer(diag, false, unusedSlide, ^(uint64_t address, bool bind, int bindLibOrdinal, const char* bindSymbolName, bool bindWeakImport, bool bindLazy, bool selfModifyingStub, bool& indStop) { if ( bind ) return; uint32_t segIndex = 0; uint64_t segOffset = 0; if ( segIndexAndOffsetForAddress(address, segIndex, segOffset) ) { handler("local relocation", true, ptrSize, segIndex, segOffset, pointerRebaseKind, indStop); } else { diag.error("local relocation has out of range r_address"); indStop = true; } }); return stop; } bool Fixups::forEachBind_Relocations(Diagnostics& diag, bool supportPrivateExternsWorkaround, intptr_t slide, BindDetailedHandler handler) const { // Firmare binaries won't have a dynSymTab if ( !this->layout.linkedit.externRelocs.hasValue() ) return false; const uint64_t relocsStartAddress = externalRelocBaseAddress(); const relocation_info* const relocsStart = (const relocation_info*)this->layout.linkedit.externRelocs.buffer; const relocation_info* const relocsEnd = &relocsStart[this->layout.linkedit.externRelocs.entryCount]; bool is64Bit = this->layout.mf->is64() ; const uint32_t ptrSize = this->layout.mf->pointerSize(); const uint32_t dylibCount = this->layout.mf->dependentDylibCount(); const uint8_t relocSize = (is64Bit ? 3 : 2); const void* symbolTable = this->layout.linkedit.symbolTable.buffer; const struct nlist_64* symbols64 = (nlist_64*)symbolTable; const struct nlist* symbols32 = (struct nlist*)symbolTable; const char* stringPool = (char*)this->layout.linkedit.symbolStrings.buffer; uint32_t symCount = this->layout.linkedit.symbolTable.entryCount; uint32_t poolSize = this->layout.linkedit.symbolStrings.bufferSize; uint32_t lastSymIndx = -1; uint64_t lastAddend = 0; bool stop = false; for (const relocation_info* reloc=relocsStart; (reloc < relocsEnd) && !stop; ++reloc) { bool isBranch = false; #if BUILDING_APP_CACHE_UTIL || BUILDING_DYLDINFO if ( this->layout.mf->isKextBundle() ) { // kext's may have other kinds of relocations, eg, branch relocs. Skip them if ( this->layout.mf->isArch("x86_64") || this->layout.mf->isArch("x86_64h") ) { if ( reloc->r_type == X86_64_RELOC_BRANCH ) { if ( reloc->r_length != 2 ) { diag.error("external relocation has wrong r_length"); break; } if ( reloc->r_pcrel != true ) { diag.error("external relocation should be pcrel"); break; } isBranch = true; } } } #endif if ( !isBranch ) { if ( reloc->r_length != relocSize ) { diag.error("external relocation has wrong r_length"); break; } if ( reloc->r_type != 0 ) { // 0 == X86_64_RELOC_UNSIGNED == GENERIC_RELOC_VANILLA == ARM64_RELOC_UNSIGNED diag.error("external relocation has wrong r_type"); break; } } uint32_t segIndex = 0; uint64_t segOffset = 0; if ( segIndexAndOffsetForAddress(relocsStartAddress+reloc->r_address, segIndex, segOffset) ) { uint32_t symbolIndex = reloc->r_symbolnum; if ( symbolIndex > symCount ) { diag.error("external relocation has out of range r_symbolnum"); break; } else { uint32_t strOffset = is64Bit ? symbols64[symbolIndex].n_un.n_strx : symbols32[symbolIndex].n_un.n_strx; uint16_t n_desc = is64Bit ? symbols64[symbolIndex].n_desc : symbols32[symbolIndex].n_desc; uint8_t n_type = is64Bit ? symbols64[symbolIndex].n_type : symbols32[symbolIndex].n_type; uint32_t libOrdinal = libOrdinalFromDesc(n_desc); if ( strOffset >= poolSize ) { diag.error("external relocation has r_symbolnum=%d which has out of range n_strx", symbolIndex); break; } else { const char* symbolName = stringPool + strOffset; bool weakImport = (n_desc & N_WEAK_REF); const uint8_t* content = this->layout.segments[segIndex].buffer + segOffset; uint64_t addend = (reloc->r_length == 3) ? *((uint64_t*)content) : *((uint32_t*)content); // Handle defined weak def symbols which need to get a special ordinal if ( ((n_type & N_TYPE) == N_SECT) && ((n_type & N_EXT) != 0) && ((n_desc & N_WEAK_DEF) != 0) ) libOrdinal = BIND_SPECIAL_DYLIB_WEAK_LOOKUP; uint8_t type = isBranch ? BIND_TYPE_TEXT_PCREL32 : BIND_TYPE_POINTER; bool targetOrAddendChanged = (lastSymIndx != symbolIndex) || (lastAddend != addend); handler("external relocation", true, true, dylibCount, libOrdinal, ptrSize, segIndex, segOffset, type, symbolName, weakImport, false, addend, targetOrAddendChanged, stop); lastSymIndx = symbolIndex; lastAddend = addend; } } } else { diag.error("local relocation has out of range r_address"); break; } } // then process indirect symbols forEachIndirectPointer(diag, supportPrivateExternsWorkaround, slide, ^(uint64_t address, bool bind, int bindLibOrdinal, const char* bindSymbolName, bool bindWeakImport, bool bindLazy, bool selfModifyingStub, bool& indStop) { if ( !bind ) return; uint32_t segIndex = 0; uint64_t segOffset = 0; if ( segIndexAndOffsetForAddress(address, segIndex, segOffset) ) { handler("indirect symbol", true, true, dylibCount, bindLibOrdinal, ptrSize, segIndex, segOffset, BIND_TYPE_POINTER, bindSymbolName, bindWeakImport, bindLazy, 0, true, indStop); } else { diag.error("indirect symbol has out of range address"); indStop = true; } }); return false; } #endif // SUPPORT_CLASSIC_RELOCS void Fixups::forEachIndirectPointer(Diagnostics& diag, bool supportPrivateExternsWorkaround, intptr_t slide, void (^handler)(uint64_t pointerAddress, bool bind, int bindLibOrdinal, const char* bindSymbolName, bool bindWeakImport, bool bindLazy, bool selfModifyingStub, bool& stop)) const { // find lazy and non-lazy pointer sections const bool is64Bit = this->layout.mf->is64(); const uint32_t* const indirectSymbolTable = (uint32_t*)this->layout.linkedit.indirectSymbolTable.buffer; const uint32_t indirectSymbolTableCount = this->layout.linkedit.indirectSymbolTable.entryCount; const uint32_t ptrSize = this->layout.mf->pointerSize(); const void* symbolTable = this->layout.linkedit.symbolTable.buffer; const struct nlist_64* symbols64 = (nlist_64*)symbolTable; const struct nlist* symbols32 = (struct nlist*)symbolTable; const char* stringPool = (char*)this->layout.linkedit.symbolStrings.buffer; uint32_t symCount = this->layout.linkedit.symbolTable.entryCount; uint32_t poolSize = this->layout.linkedit.symbolStrings.bufferSize; __block bool stop = false; // Old kexts put S_LAZY_SYMBOL_POINTERS on the __got section, even if they didn't have indirect symbols to prcess. // In that case, skip the loop as there shouldn't be anything to process if ( (indirectSymbolTableCount == 0) && this->layout.mf->isKextBundle() ) return; this->layout.mf->forEachSection(^(const dyld3::MachOFile::SectionInfo& sectInfo, bool malformedSectionRange, bool& sectionStop) { uint8_t sectionType = (sectInfo.sectFlags & SECTION_TYPE); bool selfModifyingStub = (sectionType == S_SYMBOL_STUBS) && (sectInfo.sectFlags & S_ATTR_SELF_MODIFYING_CODE) && (sectInfo.reserved2 == 5) && (this->layout.mf->cputype == CPU_TYPE_I386); if ( (sectionType != S_LAZY_SYMBOL_POINTERS) && (sectionType != S_NON_LAZY_SYMBOL_POINTERS) && !selfModifyingStub ) return; if ( (sectInfo.sectFlags & S_ATTR_SELF_MODIFYING_CODE) && !selfModifyingStub ) { diag.error("S_ATTR_SELF_MODIFYING_CODE section type only valid in old i386 binaries"); sectionStop = true; return; } uint32_t elementSize = selfModifyingStub ? sectInfo.reserved2 : ptrSize; uint32_t elementCount = (uint32_t)(sectInfo.sectSize/elementSize); if ( dyld3::greaterThanAddOrOverflow(sectInfo.reserved1, elementCount, indirectSymbolTableCount) ) { diag.error("section %s overflows indirect symbol table", sectInfo.sectName); sectionStop = true; return; } for (uint32_t i=0; (i < elementCount) && !stop; ++i) { uint32_t symNum = indirectSymbolTable[sectInfo.reserved1 + i]; if ( symNum == INDIRECT_SYMBOL_ABS ) continue; if ( symNum == INDIRECT_SYMBOL_LOCAL ) { handler(sectInfo.sectAddr+i*elementSize, false, 0, "", false, false, false, stop); continue; } if ( symNum > symCount ) { diag.error("indirect symbol[%d] = %d which is invalid symbol index", sectInfo.reserved1 + i, symNum); sectionStop = true; return; } uint16_t n_desc = is64Bit ? symbols64[symNum].n_desc : symbols32[symNum].n_desc; uint8_t n_type = is64Bit ? symbols64[symNum].n_type : symbols32[symNum].n_type; uint32_t libOrdinal = libOrdinalFromDesc(n_desc); uint32_t strOffset = is64Bit ? symbols64[symNum].n_un.n_strx : symbols32[symNum].n_un.n_strx; if ( strOffset > poolSize ) { diag.error("symbol[%d] string offset out of range", sectInfo.reserved1 + i); sectionStop = true; return; } const char* symbolName = stringPool + strOffset; bool weakImport = (n_desc & N_WEAK_REF); bool lazy = (sectionType == S_LAZY_SYMBOL_POINTERS); #if SUPPORT_PRIVATE_EXTERNS_WORKAROUND if ( lazy && ((n_type & N_PEXT) != 0) ) { // don't know why the static linker did not eliminate the internal reference to a private extern definition // As this is private extern, we know the symbol lookup will fail. We also know that this is a lazy-bind, and so // there is a corresponding rebase. The rebase will be run later, and will slide whatever value is in here. // So lets change the value in this slot, and let the existing rebase slide it for us // Note we only want to change the value in memory once, before rebases are applied. We don't want to accidentally // change it again later. if ( supportPrivateExternsWorkaround ) { uintptr_t* ptr = (uintptr_t*)((uint8_t*)(sectInfo.sectAddr+i*elementSize) + slide); uint64_t n_value = is64Bit ? symbols64[symNum].n_value : symbols32[symNum].n_value; *ptr = (uintptr_t)n_value; } continue; } #endif // Handle defined weak def symbols which need to get a special ordinal if ( ((n_type & N_TYPE) == N_SECT) && ((n_type & N_EXT) != 0) && ((n_desc & N_WEAK_DEF) != 0) ) libOrdinal = BIND_SPECIAL_DYLIB_WEAK_LOOKUP; handler(sectInfo.sectAddr+i*elementSize, true, libOrdinal, symbolName, weakImport, lazy, selfModifyingStub, stop); } sectionStop = stop; }); } uint64_t Fixups::localRelocBaseAddress() const { if ( this->layout.mf->isArch("x86_64") || this->layout.mf->isArch("x86_64h") ) { #if BUILDING_APP_CACHE_UTIL || BUILDING_DYLDINFO if ( this->layout.mf->isKextBundle() ) { // for kext bundles the reloc base address starts at __TEXT segment return this->layout.segments[0].vmAddr; } #endif // for all other kinds, the x86_64 reloc base address starts at first writable segment (usually __DATA) for ( const SegmentLayout& segment : this->layout.segments ) { if ( segment.writable() ) return segment.vmAddr; } } return this->layout.segments[0].vmAddr; } uint64_t Fixups::externalRelocBaseAddress() const { // Dyld caches are too large for a raw r_address, so everything is an offset from the base address if ( this->layout.mf->inDyldCache() ) { return this->layout.mf->preferredLoadAddress(); } #if BUILDING_APP_CACHE_UTIL || BUILDING_DYLDINFO if ( this->layout.mf->isKextBundle() ) { // for kext bundles the reloc base address starts at __TEXT segment return this->layout.mf->preferredLoadAddress(); } #endif if ( this->layout.mf->isArch("x86_64") || this->layout.mf->isArch("x86_64h") ) { // for x86_64 reloc base address starts at first writable segment (usually __DATA) for ( const SegmentLayout& segment : this->layout.segments ) { if ( segment.writable() ) return segment.vmAddr; } } // For everyone else we start at 0 return 0; } bool Fixups::segIndexAndOffsetForAddress(uint64_t addr, uint32_t& segIndex, uint64_t& segOffset) const { for (uint32_t i=0; i < this->layout.segments.size(); ++i) { const SegmentLayout& segment = this->layout.segments[i]; if ( (segment.vmAddr <= addr) && (addr < (segment.vmAddr + segment.vmSize)) ) { segIndex = i; segOffset = addr - segment.vmAddr; return true; } } return false; } int Fixups::libOrdinalFromDesc(uint16_t n_desc) const { // -flat_namespace is always flat lookup if ( (this->layout.mf->flags & MH_TWOLEVEL) == 0 ) return BIND_SPECIAL_DYLIB_FLAT_LOOKUP; // extract byte from undefined symbol entry int libIndex = GET_LIBRARY_ORDINAL(n_desc); switch ( libIndex ) { case SELF_LIBRARY_ORDINAL: return BIND_SPECIAL_DYLIB_SELF; case DYNAMIC_LOOKUP_ORDINAL: return BIND_SPECIAL_DYLIB_FLAT_LOOKUP; case EXECUTABLE_ORDINAL: return BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE; } return libIndex; } // MARK: --- SplitSeg methods --- SplitSeg::SplitSeg(const Layout& layout) : layout(layout) { } bool SplitSeg::hasMarker() const { if ( !this->layout.linkedit.splitSegInfo.hasValue() ) return false; return this->layout.linkedit.splitSegInfo.bufferSize == 0; } bool SplitSeg::isV1() const { if ( !this->layout.linkedit.splitSegInfo.hasValue() ) return false; const void* splitSegStart = this->layout.linkedit.splitSegInfo.buffer; return (*(const uint8_t*)splitSegStart) != DYLD_CACHE_ADJ_V2_FORMAT; } bool SplitSeg::isV2() const { if ( !this->layout.linkedit.splitSegInfo.hasValue() ) return false; const void* splitSegStart = this->layout.linkedit.splitSegInfo.buffer; return (*(const uint8_t*)splitSegStart) == DYLD_CACHE_ADJ_V2_FORMAT; } bool SplitSeg::hasValue() const { return this->layout.linkedit.splitSegInfo.hasValue(); } void SplitSeg::forEachReferenceV2(Diagnostics& diag, ReferenceCallbackV2 callback) const { const uint8_t* infoStart = layout.linkedit.splitSegInfo.buffer; const uint8_t* infoEnd = infoStart + layout.linkedit.splitSegInfo.bufferSize; if ( *infoStart++ != DYLD_CACHE_ADJ_V2_FORMAT ) { return; } // Whole :== <count> FromToSection+ // FromToSection :== <from-sect-index> <to-sect-index> <count> ToOffset+ // ToOffset :== <to-sect-offset-delta> <count> FromOffset+ // FromOffset :== <kind> <count> <from-sect-offset-delta> const uint8_t* p = infoStart; uint64_t sectionCount = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); for (uint64_t i=0; i < sectionCount; ++i) { uint64_t fromSectionIndex = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); uint64_t toSectionIndex = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); uint64_t toOffsetCount = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); uint64_t toSectionOffset = 0; for (uint64_t j=0; j < toOffsetCount; ++j) { uint64_t toSectionDelta = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); uint64_t fromOffsetCount = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); toSectionOffset += toSectionDelta; for (uint64_t k=0; k < fromOffsetCount; ++k) { uint64_t kind = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); if ( kind > 13 ) { diag.error("bad kind (%llu) value in %s\n", kind, this->layout.mf->installName()); } uint64_t fromSectDeltaCount = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); uint64_t fromSectionOffset = 0; for (uint64_t l=0; l < fromSectDeltaCount; ++l) { uint64_t delta = dyld3::MachOFile::read_uleb128(diag, p, infoEnd); fromSectionOffset += delta; bool stop = false; callback(fromSectionIndex, fromSectionOffset, toSectionIndex, toSectionOffset, stop); if ( stop ) return; } } } } } void SplitSeg::forEachSplitSegSection(void (^callback)(std::string_view segmentName, std::string_view sectionName, uint64_t sectionVMAddr)) const { callback("mach header", "", 0); this->layout.mf->forEachSection(^(const dyld3::MachOFile::SectionInfo §Info, bool malformedSectionRange, bool &stop) { std::string_view segmentName(sectInfo.segInfo.segName, strnlen(sectInfo.segInfo.segName, 16)); std::string_view sectionName(sectInfo.sectName, strnlen(sectInfo.sectName, 16)); callback(segmentName, sectionName, sectInfo.sectAddr); }); } // MARK: --- ExportTrie methods --- ExportTrie::ExportTrie(const Layout& layout) : layout(layout) { } static void recurseTrie(Diagnostics& diag, const uint8_t* const start, const uint8_t* p, const uint8_t* const end, dyld3::OverflowSafeArray<char>& cummulativeString, int curStrOffset, bool& stop, ExportTrie::ExportsCallback callback) { if ( p >= end ) { diag.error("malformed trie, node past end"); return; } const uint64_t terminalSize = dyld3::MachOFile::read_uleb128(diag, p, end); const uint8_t* children = p + terminalSize; if ( terminalSize != 0 ) { uint64_t imageOffset = 0; uint64_t flags = dyld3::MachOFile::read_uleb128(diag, p, end); uint64_t other = 0; const char* importName = nullptr; if ( flags & EXPORT_SYMBOL_FLAGS_REEXPORT ) { other = dyld3::MachOFile::read_uleb128(diag, p, end); // dylib ordinal importName = (char*)p; } else { imageOffset = dyld3::MachOFile::read_uleb128(diag, p, end); if ( flags & EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER ) other = dyld3::MachOFile::read_uleb128(diag, p, end); else other = 0; } if ( diag.hasError() ) return; callback(cummulativeString.begin(), imageOffset, flags, other, importName, stop); if ( stop ) return; } if ( children > end ) { diag.error("malformed trie, terminalSize extends beyond trie data"); return; } const uint8_t childrenCount = *children++; const uint8_t* s = children; for (uint8_t i=0; i < childrenCount; ++i) { int edgeStrLen = 0; while (*s != '\0') { cummulativeString.resize(curStrOffset+edgeStrLen + 1); cummulativeString[curStrOffset+edgeStrLen] = *s++; ++edgeStrLen; if ( s > end ) { diag.error("malformed trie node, child node extends past end of trie\n"); return; } } cummulativeString.resize(curStrOffset+edgeStrLen + 1); cummulativeString[curStrOffset+edgeStrLen] = *s++; uint64_t childNodeOffset = dyld3::MachOFile::read_uleb128(diag, s, end); if (childNodeOffset == 0) { diag.error("malformed trie, childNodeOffset==0"); return; } recurseTrie(diag, start, start+childNodeOffset, end, cummulativeString, curStrOffset+edgeStrLen, stop, callback); if ( diag.hasError() || stop ) return; } } void ExportTrie::forEachExportedSymbol(Diagnostics& diag, ExportsCallback callback) const { if ( layout.linkedit.exportsTrie.hasValue() ) { const uint8_t* trieStart = layout.linkedit.exportsTrie.buffer; const uint8_t* trieEnd = trieStart + layout.linkedit.exportsTrie.bufferSize; // We still emit empty export trie load commands just as a placeholder to show we have // no exports. In that case, don't start recursing as we'll immediately think we ran // of the end of the buffer if ( trieStart == trieEnd ) return; bool stop = false; STACK_ALLOC_OVERFLOW_SAFE_ARRAY(char, cummulativeString, 4096); recurseTrie(diag, trieStart, trieStart, trieEnd, cummulativeString, 0, stop, callback); } } // MARK: --- ChainedFixupPointerOnDisk methods --- uint64_t ChainedFixupPointerOnDisk::Arm64e::unpackTarget() const { assert(this->authBind.bind == 0); assert(this->authBind.auth == 0); return ((uint64_t)(this->rebase.high8) << 56) | (this->rebase.target); } uint64_t ChainedFixupPointerOnDisk::Arm64e::signExtendedAddend() const { assert(this->authBind.bind == 1); assert(this->authBind.auth == 0); uint64_t addend19 = this->bind.addend; if ( addend19 & 0x40000 ) return addend19 | 0xFFFFFFFFFFFC0000ULL; else return addend19; } const char* ChainedFixupPointerOnDisk::Arm64e::keyName(uint8_t keyBits) { static const char* const names[] = { "IA", "IB", "DA", "DB" }; assert(keyBits < 4); return names[keyBits]; } const char* ChainedFixupPointerOnDisk::Arm64e::keyName() const { assert(this->authBind.auth == 1); return keyName(this->authBind.key); } uint64_t ChainedFixupPointerOnDisk::Arm64e::signPointer(uint64_t unsignedAddr, void* loc, bool addrDiv, uint16_t diversity, uint8_t key) { // don't sign NULL if ( unsignedAddr == 0 ) return 0; #if __has_feature(ptrauth_calls) uint64_t extendedDiscriminator = diversity; if ( addrDiv ) extendedDiscriminator = __builtin_ptrauth_blend_discriminator(loc, extendedDiscriminator); switch ( key ) { case 0: // IA return (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)unsignedAddr, 0, extendedDiscriminator); case 1: // IB return (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)unsignedAddr, 1, extendedDiscriminator); case 2: // DA return (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)unsignedAddr, 2, extendedDiscriminator); case 3: // DB return (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)unsignedAddr, 3, extendedDiscriminator); } assert(0 && "invalid signing key"); #else assert(0 && "arm64e signing only arm64e"); #endif } uint64_t ChainedFixupPointerOnDisk::Arm64e::signPointer(void* loc, uint64_t target) const { assert(this->authBind.auth == 1); return signPointer(target, loc, authBind.addrDiv, authBind.diversity, authBind.key); } uint64_t ChainedFixupPointerOnDisk::Generic64::unpackedTarget() const { return (((uint64_t)this->rebase.high8) << 56) | (uint64_t)(this->rebase.target); } uint64_t ChainedFixupPointerOnDisk::Generic64::signExtendedAddend() const { uint64_t addend27 = this->bind.addend; uint64_t top8Bits = addend27 & 0x00007F80000ULL; uint64_t bottom19Bits = addend27 & 0x0000007FFFFULL; uint64_t newValue = (top8Bits << 13) | (((uint64_t)(bottom19Bits << 37) >> 37) & 0x00FFFFFFFFFFFFFF); return newValue; } const char* ChainedFixupPointerOnDisk::Kernel64::keyName() const { static const char* names[] = { "IA", "IB", "DA", "DB" }; assert(this->isAuth == 1); uint8_t keyBits = this->key; assert(keyBits < 4); return names[keyBits]; } uint64_t ChainedFixupPointerOnDisk::Cache64e::high8() const { assert(this->regular.auth == 0); return ((uint64_t)(this->regular.high8) << 56); } const char* ChainedFixupPointerOnDisk::Cache64e::keyName() const { assert(this->auth.auth == 1); static const char* const names[] = { "IA", "DA" }; assert(this->auth.keyIsData < 2); return names[this->auth.keyIsData]; } uint64_t ChainedFixupPointerOnDisk::Cache64e::signPointer(uint64_t unsignedAddr, void* loc, bool addrDiv, uint16_t diversity, uint8_t keyIsData) { // don't sign NULL if ( unsignedAddr == 0 ) return 0; #if __has_feature(ptrauth_calls) uint64_t extendedDiscriminator = diversity; if ( addrDiv ) extendedDiscriminator = __builtin_ptrauth_blend_discriminator(loc, extendedDiscriminator); switch ( keyIsData ) { case 0: // IA return (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)unsignedAddr, 0, extendedDiscriminator); case 1: // DA return (uintptr_t)__builtin_ptrauth_sign_unauthenticated((void*)unsignedAddr, 2, extendedDiscriminator); } assert(0 && "invalid signing key"); #else assert(0 && "arm64e signing only arm64e"); #endif } uint64_t ChainedFixupPointerOnDisk::Cache64e::signPointer(void* loc, uint64_t target) const { assert(this->auth.auth == 1); return signPointer(target, loc, auth.addrDiv, auth.diversity, auth.keyIsData); } bool ChainedFixupPointerOnDisk::isRebase(uint16_t pointerFormat, uint64_t preferedLoadAddress, uint64_t& targetRuntimeOffset) const { switch (pointerFormat) { case DYLD_CHAINED_PTR_ARM64E: case DYLD_CHAINED_PTR_ARM64E_USERLAND: case DYLD_CHAINED_PTR_ARM64E_USERLAND24: case DYLD_CHAINED_PTR_ARM64E_KERNEL: case DYLD_CHAINED_PTR_ARM64E_FIRMWARE: if ( this->arm64e.bind.bind ) return false; if ( this->arm64e.authRebase.auth ) { targetRuntimeOffset = this->arm64e.authRebase.target; return true; } else { targetRuntimeOffset = this->arm64e.unpackTarget(); if ( (pointerFormat == DYLD_CHAINED_PTR_ARM64E) || (pointerFormat == DYLD_CHAINED_PTR_ARM64E_FIRMWARE) ) { targetRuntimeOffset -= preferedLoadAddress; } return true; } break; case DYLD_CHAINED_PTR_64: case DYLD_CHAINED_PTR_64_OFFSET: if ( this->generic64.bind.bind ) return false; targetRuntimeOffset = this->generic64.unpackedTarget(); if ( pointerFormat == DYLD_CHAINED_PTR_64 ) targetRuntimeOffset -= preferedLoadAddress; return true; break; case DYLD_CHAINED_PTR_64_KERNEL_CACHE: case DYLD_CHAINED_PTR_X86_64_KERNEL_CACHE: targetRuntimeOffset = this->kernel64.target; return true; break; case DYLD_CHAINED_PTR_32: if ( this->generic32.bind.bind ) return false; targetRuntimeOffset = this->generic32.rebase.target - preferedLoadAddress; return true; break; case DYLD_CHAINED_PTR_32_FIRMWARE: targetRuntimeOffset = this->firmware32.target - preferedLoadAddress; return true; break; case DYLD_CHAINED_PTR_ARM64E_SHARED_CACHE: if ( this->cache64e.regular.auth ) { targetRuntimeOffset = this->cache64e.auth.runtimeOffset; return true; } else { targetRuntimeOffset = this->cache64e.regular.runtimeOffset; return true; } break; default: break; } assert(0 && "unsupported pointer chain format"); } bool ChainedFixupPointerOnDisk::isBind(uint16_t pointerFormat, uint32_t& bindOrdinal, int64_t& addend) const { addend = 0; switch (pointerFormat) { case DYLD_CHAINED_PTR_ARM64E: case DYLD_CHAINED_PTR_ARM64E_USERLAND: case DYLD_CHAINED_PTR_ARM64E_USERLAND24: case DYLD_CHAINED_PTR_ARM64E_KERNEL: case DYLD_CHAINED_PTR_ARM64E_FIRMWARE: if ( !this->arm64e.authBind.bind ) return false; if ( this->arm64e.authBind.auth ) { if ( pointerFormat == DYLD_CHAINED_PTR_ARM64E_USERLAND24 ) bindOrdinal = this->arm64e.authBind24.ordinal; else bindOrdinal = this->arm64e.authBind.ordinal; return true; } else { if ( pointerFormat == DYLD_CHAINED_PTR_ARM64E_USERLAND24 ) bindOrdinal = this->arm64e.bind24.ordinal; else bindOrdinal = this->arm64e.bind.ordinal; addend = this->arm64e.signExtendedAddend(); return true; } break; case DYLD_CHAINED_PTR_64: case DYLD_CHAINED_PTR_64_OFFSET: if ( !this->generic64.bind.bind ) return false; bindOrdinal = this->generic64.bind.ordinal; addend = this->generic64.bind.addend; return true; break; case DYLD_CHAINED_PTR_32: if ( !this->generic32.bind.bind ) return false; bindOrdinal = this->generic32.bind.ordinal; addend = this->generic32.bind.addend; return true; break; case DYLD_CHAINED_PTR_64_KERNEL_CACHE: case DYLD_CHAINED_PTR_X86_64_KERNEL_CACHE: return false; default: break; } assert(0 && "unsupported pointer chain format"); } unsigned ChainedFixupPointerOnDisk::strideSize(uint16_t pointerFormat) { switch (pointerFormat) { case DYLD_CHAINED_PTR_ARM64E: case DYLD_CHAINED_PTR_ARM64E_USERLAND: case DYLD_CHAINED_PTR_ARM64E_USERLAND24: case DYLD_CHAINED_PTR_ARM64E_SHARED_CACHE: return 8; case DYLD_CHAINED_PTR_ARM64E_KERNEL: case DYLD_CHAINED_PTR_ARM64E_FIRMWARE: case DYLD_CHAINED_PTR_32_FIRMWARE: case DYLD_CHAINED_PTR_64: case DYLD_CHAINED_PTR_64_OFFSET: case DYLD_CHAINED_PTR_32: case DYLD_CHAINED_PTR_32_CACHE: case DYLD_CHAINED_PTR_64_KERNEL_CACHE: return 4; case DYLD_CHAINED_PTR_X86_64_KERNEL_CACHE: return 1; } assert(0 && "unsupported pointer chain format"); } // MARK: --- SymbolTable methods --- SymbolTable::SymbolTable(const Layout& layout) : layout(layout) { } void SymbolTable::forEachLocalSymbol(Diagnostics& diag, void (^callback)(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, bool& stop)) const { const bool is64Bit = this->layout.mf->is64(); if ( this->layout.linkedit.symbolTable.hasValue() ) { uint32_t localsStartIndex = 0; uint32_t localsCount = this->layout.linkedit.symbolTable.entryCount; if ( this->layout.linkedit.localSymbolTable.hasValue() ) { localsStartIndex = this->layout.linkedit.localSymbolTable.entryIndex; localsCount = this->layout.linkedit.localSymbolTable.entryCount; } uint32_t maxStringOffset = this->layout.linkedit.symbolStrings.bufferSize; const char* stringPool = (char*)this->layout.linkedit.symbolStrings.buffer; const struct nlist* symbols = (struct nlist*)this->layout.linkedit.symbolTable.buffer; const struct nlist_64* symbols64 = (struct nlist_64*)this->layout.linkedit.symbolTable.buffer; bool stop = false; for (uint32_t i=0; (i < localsCount) && !stop; ++i) { if ( is64Bit ) { const struct nlist_64& sym = symbols64[localsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( ((sym.n_type & N_EXT) == 0) && ((sym.n_type & N_TYPE) == N_SECT) && ((sym.n_type & N_STAB) == 0) ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } else { const struct nlist& sym = symbols[localsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( ((sym.n_type & N_EXT) == 0) && ((sym.n_type & N_TYPE) == N_SECT) && ((sym.n_type & N_STAB) == 0) ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } } } } void SymbolTable::forEachGlobalSymbol(Diagnostics& diag, void (^callback)(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, bool& stop)) const { const bool is64Bit = this->layout.mf->is64(); if ( this->layout.linkedit.symbolTable.hasValue() ) { uint32_t globalsStartIndex = 0; uint32_t globalsCount = this->layout.linkedit.symbolTable.entryCount; if ( this->layout.linkedit.globalSymbolTable.hasValue() ) { globalsStartIndex = this->layout.linkedit.globalSymbolTable.entryIndex; globalsCount = this->layout.linkedit.globalSymbolTable.entryCount; } uint32_t maxStringOffset = this->layout.linkedit.symbolStrings.bufferSize; const char* stringPool = (char*)this->layout.linkedit.symbolStrings.buffer; const struct nlist* symbols = (struct nlist*)this->layout.linkedit.symbolTable.buffer; const struct nlist_64* symbols64 = (struct nlist_64*)this->layout.linkedit.symbolTable.buffer; bool stop = false; for (uint32_t i=0; (i < globalsCount) && !stop; ++i) { if ( is64Bit ) { const struct nlist_64& sym = symbols64[globalsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( (sym.n_type & N_EXT) && ((sym.n_type & N_TYPE) == N_SECT) && ((sym.n_type & N_STAB) == 0) ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } else { const struct nlist& sym = symbols[globalsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( (sym.n_type & N_EXT) && ((sym.n_type & N_TYPE) == N_SECT) && ((sym.n_type & N_STAB) == 0) ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } } } } void SymbolTable::forEachImportedSymbol(Diagnostics& diag, void (^callback)(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, bool& stop)) const { const bool is64Bit = this->layout.mf->is64(); if ( this->layout.linkedit.symbolTable.hasValue() ) { uint32_t undefsStartIndex = 0; uint32_t undefsCount = this->layout.linkedit.symbolTable.entryCount; if ( this->layout.linkedit.undefSymbolTable.hasValue() ) { undefsStartIndex = this->layout.linkedit.undefSymbolTable.entryIndex; undefsCount = this->layout.linkedit.undefSymbolTable.entryCount; } uint32_t maxStringOffset = this->layout.linkedit.symbolStrings.bufferSize; const char* stringPool = (char*)this->layout.linkedit.symbolStrings.buffer; const struct nlist* symbols = (struct nlist*)this->layout.linkedit.symbolTable.buffer; const struct nlist_64* symbols64 = (struct nlist_64*)this->layout.linkedit.symbolTable.buffer; bool stop = false; for (uint32_t i=0; (i < undefsCount) && !stop; ++i) { if ( is64Bit ) { const struct nlist_64& sym = symbols64[undefsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( (sym.n_type & N_TYPE) == N_UNDF ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } else { const struct nlist& sym = symbols[undefsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( (sym.n_type & N_TYPE) == N_UNDF ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } } } } void SymbolTable::forEachIndirectSymbol(Diagnostics& diag, void (^callback)(const char* symbolName, uint32_t symNum)) const { // find lazy and non-lazy pointer sections const bool is64Bit = this->layout.mf->is64(); const uint32_t* const indirectSymbolTable = (uint32_t*)this->layout.linkedit.indirectSymbolTable.buffer; const uint32_t indirectSymbolTableCount = this->layout.linkedit.indirectSymbolTable.entryCount; const void* symbolTable = this->layout.linkedit.symbolTable.buffer; const struct nlist_64* symbols64 = (nlist_64*)symbolTable; const struct nlist* symbols32 = (struct nlist*)symbolTable; const char* stringPool = (char*)this->layout.linkedit.symbolStrings.buffer; uint32_t symCount = this->layout.linkedit.symbolTable.entryCount; uint32_t poolSize = this->layout.linkedit.symbolStrings.bufferSize; if ( indirectSymbolTableCount == 0 ) return; for (uint32_t i = 0; i != indirectSymbolTableCount; ++i ) { uint32_t symNum = indirectSymbolTable[i]; if ( symNum == INDIRECT_SYMBOL_ABS ) { // FIXME: The client wants to know about all the entries, so what should we pass here? callback(nullptr, symNum); continue; } if ( symNum == INDIRECT_SYMBOL_LOCAL ) { callback("", symNum); continue; } if ( symNum == (INDIRECT_SYMBOL_LOCAL | INDIRECT_SYMBOL_ABS) ) { // FIXME: We are using the "local" callback. Should we use the "abs" one instead callback("", symNum); continue; } if ( symNum > symCount ) { diag.error("indirect symbol[%d] = %d which is invalid symbol index", i, symNum); return; } uint32_t strOffset = is64Bit ? symbols64[symNum].n_un.n_strx : symbols32[symNum].n_un.n_strx; if ( strOffset > poolSize ) { diag.error("symbol[%d] string offset out of range", i); return; } const char* symbolName = stringPool + strOffset; callback(symbolName, symNum); } } } // namespace mach_o |