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--- /dev/null
+++ dyld/dyld-940/other-tools/dsc_extractor.cpp
@@ -0,0 +1,1070 @@
+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2011 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 <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include <sys/syslimits.h>
+#include <libkern/OSByteOrder.h>
+#include <mach-o/arch.h>
+#include <mach-o/loader.h>
+#include <Availability.h>
+
+#include "CodeSigningTypes.h"
+#include <CommonCrypto/CommonHMAC.h>
+#include <CommonCrypto/CommonDigest.h>
+#include <CommonCrypto/CommonDigestSPI.h>
+
+#define NO_ULEB
+#include "Architectures.hpp"
+#include "MachOFileAbstraction.hpp"
+
+#include "dsc_iterator.h"
+#include "dsc_extractor.h"
+#include "DyldSharedCache.h"
+#include "MachOAnalyzer.h"
+#include "SupportedArchs.h"
+#include "Trie.hpp"
+#include "JSONWriter.h"
+#include "StringUtils.h"
+
+#include <vector>
+#include <set>
+#include <map>
+#include <unordered_map>
+#include <algorithm>
+#include <dispatch/dispatch.h>
+#include <optional>
+
+static int sharedCacheIsValid(const void* mapped_cache, uint64_t size) {
+ // First check that the size is good.
+ // Note the shared cache may not have a codeSignatureSize value set so we need to first make
+ // sure we have space for the CS_SuperBlob, then later crack that to check for the size of the rest.
+ const DyldSharedCache* dyldSharedCache = (DyldSharedCache*)mapped_cache;
+ uint64_t requiredSizeForCSSuperBlob = dyldSharedCache->header.codeSignatureOffset + sizeof(CS_SuperBlob);
+ const dyld_cache_mapping_info* mappings = (dyld_cache_mapping_info*)((uint8_t*)mapped_cache + dyldSharedCache->header.mappingOffset);
+ if ( requiredSizeForCSSuperBlob > size ) {
+ fprintf(stderr, "Error: dyld shared cache size 0x%08llx is less than required size of 0x%08llx.\n", size, requiredSizeForCSSuperBlob);
+ return -1;
+ }
+
+ // Now see if the code signatures are valid as that tells us the pages aren't corrupt.
+ // First find all of the regions of the shared cache we computed cd hashes
+ std::vector<std::pair<uint64_t, uint64_t>> sharedCacheRegions;
+ for (uint32_t i = 0; i != dyldSharedCache->header.mappingCount; ++i) {
+ sharedCacheRegions.emplace_back(std::make_pair(mappings[i].fileOffset, mappings[i].fileOffset + mappings[i].size));
+ }
+ if (dyldSharedCache->header.localSymbolsSize)
+ sharedCacheRegions.emplace_back(std::make_pair(dyldSharedCache->header.localSymbolsOffset, dyldSharedCache->header.localSymbolsOffset + dyldSharedCache->header.localSymbolsSize));
+ size_t inBbufferSize = 0;
+ for (auto& sharedCacheRegion : sharedCacheRegions)
+ inBbufferSize += (sharedCacheRegion.second - sharedCacheRegion.first);
+
+ // Now take the cd hash from the cache itself and validate the regions we found.
+ uint8_t* codeSignatureRegion = (uint8_t*)mapped_cache + dyldSharedCache->header.codeSignatureOffset;
+ CS_SuperBlob* sb = reinterpret_cast<CS_SuperBlob*>(codeSignatureRegion);
+ if (sb->magic != htonl(CSMAGIC_EMBEDDED_SIGNATURE)) {
+ fprintf(stderr, "Error: dyld shared cache code signature magic is incorrect.\n");
+ return -1;
+ }
+
+ size_t sbSize = ntohl(sb->length);
+ uint64_t requiredSizeForCS = dyldSharedCache->header.codeSignatureOffset + sbSize;
+ if ( requiredSizeForCS > size ) {
+ fprintf(stderr, "Error: dyld shared cache size 0x%08llx is less than required size of 0x%08llx.\n", size, requiredSizeForCS);
+ return -1;
+ }
+
+ // Find the offset to the code directory.
+ CS_CodeDirectory* cd = nullptr;
+ for (unsigned i =0; i != sb->count; ++i) {
+ if (ntohl(sb->index[i].type) == CSSLOT_CODEDIRECTORY) {
+ cd = (CS_CodeDirectory*)(codeSignatureRegion + ntohl(sb->index[i].offset));
+ break;
+ }
+ }
+
+ if (!cd) {
+ fprintf(stderr, "Error: dyld shared cache code signature directory is missing.\n");
+ return -1;
+ }
+
+ if ( (uint8_t*)cd > (codeSignatureRegion + sbSize) ) {
+ fprintf(stderr, "Error: dyld shared cache code signature directory is out of bounds.\n");
+ return -1;
+ }
+
+ if ( cd->magic != htonl(CSMAGIC_CODEDIRECTORY) ) {
+ fprintf(stderr, "Error: dyld shared cache code signature directory magic is incorrect.\n");
+ return -1;
+ }
+
+ uint32_t pageSize = 1 << cd->pageSize;
+ uint32_t slotCountFromRegions = (uint32_t)((inBbufferSize + pageSize - 1) / pageSize);
+ if ( ntohl(cd->nCodeSlots) < slotCountFromRegions ) {
+ fprintf(stderr, "Error: dyld shared cache code signature directory num slots is incorrect.\n");
+ return -1;
+ }
+
+ uint32_t dscDigestFormat = kCCDigestNone;
+ switch (cd->hashType) {
+ case CS_HASHTYPE_SHA1:
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
+ dscDigestFormat = kCCDigestSHA1;
+#pragma clang diagnostic pop
+ break;
+ case CS_HASHTYPE_SHA256:
+ dscDigestFormat = kCCDigestSHA256;
+ break;
+ default:
+ break;
+ }
+
+ if (dscDigestFormat != kCCDigestNone) {
+ const uint64_t csPageSize = 1 << cd->pageSize;
+ size_t hashOffset = ntohl(cd->hashOffset);
+ uint8_t* hashSlot = (uint8_t*)cd + hashOffset;
+ uint8_t cdHashBuffer[cd->hashSize];
+
+ // Skip local symbols for now as those aren't being codesign correctly right now.
+ size_t bufferSize = 0;
+ for (auto& sharedCacheRegion : sharedCacheRegions) {
+ if ( (dyldSharedCache->header.localSymbolsSize != 0) && (sharedCacheRegion.first == dyldSharedCache->header.localSymbolsOffset) )
+ continue;
+ bufferSize += (sharedCacheRegion.second - sharedCacheRegion.first);
+ }
+ uint32_t slotCountToProcess = (uint32_t)((bufferSize + pageSize - 1) / pageSize);
+
+ for (unsigned i = 0; i != slotCountToProcess; ++i) {
+ // Skip data pages as those may have been slid by ASLR in the extracted file
+ uint64_t fileOffset = i * csPageSize;
+ bool isDataPage = false;
+ for (unsigned mappingIndex = 0; mappingIndex != dyldSharedCache->header.mappingCount; ++mappingIndex) {
+ if ( (mappings[mappingIndex].maxProt & VM_PROT_WRITE) == 0 )
+ continue;
+ if ( (fileOffset >= mappings[mappingIndex].fileOffset) && (fileOffset < (mappings[mappingIndex].fileOffset + mappings[mappingIndex].size)) ) {
+ isDataPage = true;
+ break;
+ }
+ }
+ if ( isDataPage )
+ continue;
+
+ CCDigest(dscDigestFormat, (uint8_t*)mapped_cache + fileOffset, (size_t)csPageSize, cdHashBuffer);
+ uint8_t* cacheCdHashBuffer = hashSlot + (i * cd->hashSize);
+ if (memcmp(cdHashBuffer, cacheCdHashBuffer, cd->hashSize) != 0) {
+ fprintf(stderr, "Error: dyld shared cache code signature for page %d is incorrect.\n", i);
+ return -1;
+ }
+ }
+ }
+ return 0;
+}
+
+// A MappedCache provides access to all the parts of a cache file, even those typically not mapped at runtime
+struct MappedCache {
+ const DyldSharedCache* dyldCache = nullptr;
+ size_t fileSize = 0;
+ size_t vmSize = 0;
+};
+
+// mmap() an shared cache file read/only but laid out like it would be at runtime
+static std::optional<MappedCache> mapCacheFile(const char* path,
+ uint64_t baseCacheUnslidAddress,
+ uint8_t* buffer,
+ bool isLocalSymbolsCache)
+{
+ struct stat statbuf;
+ if ( ::stat(path, &statbuf) ) {
+ fprintf(stderr, "Error: stat failed for dyld shared cache at %s\n", path);
+ return {};
+ }
+
+ int cache_fd = ::open(path, O_RDONLY);
+ if (cache_fd < 0) {
+ fprintf(stderr, "Error: failed to open shared cache file at %s\n", path);
+ return {};
+ }
+
+ uint8_t firstPage[4096];
+ if ( ::pread(cache_fd, firstPage, 4096, 0) != 4096 ) {
+ fprintf(stderr, "Error: failed to read shared cache file at %s\n", path);
+ return {};
+ }
+ const dyld_cache_header* header = (dyld_cache_header*)firstPage;
+ if ( strstr(header->magic, "dyld_v1") != header->magic ) {
+ fprintf(stderr, "Error: Invalid cache magic in file at %s\n", path);
+ return {};
+ }
+ if ( header->mappingCount == 0 ) {
+ fprintf(stderr, "Error: No mapping in shared cache file at %s\n", path);
+ return {};
+ }
+
+ // Use the cache code signature to see if the cache file is valid.
+ // Note we do this now, as we don't even want to trust the mappings are valid.
+ {
+ void* mapped_cache = ::mmap(nullptr, (size_t)statbuf.st_size, PROT_READ, MAP_PRIVATE, cache_fd, 0);
+ if (mapped_cache == MAP_FAILED) {
+ fprintf(stderr, "Error: mmap() for shared cache at %s failed, errno=%d\n", path, errno);
+ return {};
+ }
+ int isValidResult = sharedCacheIsValid(mapped_cache, statbuf.st_size);
+ ::munmap(mapped_cache, (size_t)statbuf.st_size);
+ if ( isValidResult != 0 ) {
+ fprintf(stderr, "Error: shared cache failed validity check for file at %s\n", path);
+ return {};
+ }
+ }
+
+ // The local symbols cache just wants an mmap as we don't want to change offsets there
+ if ( isLocalSymbolsCache ) {
+ void* mapped_cache = ::mmap(nullptr, (size_t)statbuf.st_size, PROT_READ, MAP_PRIVATE, cache_fd, 0);
+ if (mapped_cache == MAP_FAILED) {
+ fprintf(stderr, "Error: mmap() for shared cache at %s failed, errno=%d\n", path, errno);
+ return {};
+ }
+
+ ::close(cache_fd);
+
+ MappedCache mappedCache;
+ mappedCache.dyldCache = (DyldSharedCache*)mapped_cache;
+ mappedCache.fileSize = (size_t)statbuf.st_size;
+
+ return mappedCache;
+ }
+
+ const dyld_cache_mapping_info* mappings = (dyld_cache_mapping_info*)(firstPage + header->mappingOffset);
+ const dyld_cache_mapping_info* lastMapping = &mappings[header->mappingCount - 1];
+
+ // Allocate enough space for the cache and all subCaches
+ uint64_t subCacheBufferOffset = 0;
+ size_t vmSize = (size_t)((DyldSharedCache*)header)->mappedSize();
+ if ( baseCacheUnslidAddress == 0 ) {
+ // If the size is 0, then we might be looking directly at a sub cache. In that case just allocate a buffer large
+ // enough for its mappings.
+ if ( vmSize == 0 ) {
+ vmSize = (size_t)(lastMapping->address + lastMapping->size - mappings[0].address);
+ }
+ vm_address_t result;
+ kern_return_t r = ::vm_allocate(mach_task_self(), &result, vmSize, VM_FLAGS_ANYWHERE);
+ if ( r != KERN_SUCCESS ) {
+ fprintf(stderr, "Error: failed to allocate space to load shared cache file at %s\n", path);
+ return {};
+ }
+ buffer = (uint8_t*)result;
+ } else {
+ subCacheBufferOffset = mappings[0].address - baseCacheUnslidAddress;
+ }
+
+ for (uint32_t i=0; i < header->mappingCount; ++i) {
+ uint64_t mappingAddressOffset = mappings[i].address - mappings[0].address;
+ void* mapped_cache = ::mmap((void*)(buffer + mappingAddressOffset + subCacheBufferOffset), (size_t)mappings[i].size,
+ PROT_READ, MAP_FIXED | MAP_PRIVATE, cache_fd, mappings[i].fileOffset);
+ if (mapped_cache == MAP_FAILED) {
+ fprintf(stderr, "Error: mmap() for shared cache at %s failed, errno=%d\n", path, errno);
+ return {};
+ }
+ }
+
+ ::close(cache_fd);
+
+ MappedCache mappedCache;
+ mappedCache.dyldCache = (DyldSharedCache*)(buffer + subCacheBufferOffset);
+ mappedCache.fileSize = (size_t)statbuf.st_size;
+ mappedCache.vmSize = vmSize;
+
+ return mappedCache;
+}
+
+struct CacheFiles {
+ std::vector<MappedCache> caches;
+
+ // Keep track of the vm allocated space for the cache buffer so that we can free it later
+ vm_address_t cacheBuffer = 0;
+ vm_size_t allocatedBufferSize = 0;
+
+ // Local symbols are in an mmap()ed region
+ std::optional<MappedCache> localSymbolsCache;
+
+ void unload() {
+ vm_deallocate(mach_task_self(), cacheBuffer, allocatedBufferSize);
+ if ( localSymbolsCache.has_value() )
+ ::munmap((void*)localSymbolsCache->dyldCache, localSymbolsCache->fileSize);
+ }
+};
+
+static CacheFiles mapCacheFiles(const char* path)
+{
+ std::optional<MappedCache> mappedCache = mapCacheFile(path, 0, nullptr, false);
+ if ( !mappedCache.has_value() )
+ return {};
+
+ std::vector<MappedCache> caches;
+ caches.push_back(mappedCache.value());
+
+ const DyldSharedCache* cache = mappedCache.value().dyldCache;
+
+ // Load all subcaches, if we have them
+ if ( cache->header.mappingOffset >= __offsetof(dyld_cache_header, subCacheArrayCount) ) {
+ if ( cache->header.subCacheArrayCount != 0 ) {
+ const dyld_subcache_entry* subCacheEntries = (dyld_subcache_entry*)((uint8_t*)cache + cache->header.subCacheArrayOffset);
+
+ for (uint32_t i = 0; i != cache->header.subCacheArrayCount; ++i) {
+ std::string subCachePath = std::string(path) + "." + dyld3::json::decimal(i + 1);
+ std::optional<MappedCache> mappedSubCache = mapCacheFile(subCachePath.c_str(), cache->unslidLoadAddress(), (uint8_t*)cache, false);
+ if ( !mappedSubCache.has_value() )
+ return {};
+
+ const DyldSharedCache* subCache = mappedSubCache.value().dyldCache;
+
+ if ( memcmp(subCache->header.uuid, subCacheEntries[i].uuid, 16) != 0 ) {
+ uuid_string_t expectedUUIDString;
+ uuid_unparse_upper(subCacheEntries[i].uuid, expectedUUIDString);
+ uuid_string_t foundUUIDString;
+ uuid_unparse_upper(subCache->header.uuid, foundUUIDString);
+ fprintf(stderr, "Error: SubCache[%i] UUID mismatch. Expected %s, got %s\n", i, expectedUUIDString, foundUUIDString);
+ return {};
+ }
+
+ caches.push_back(mappedSubCache.value());
+ }
+ }
+ }
+
+ // On old caches, the locals come from the same file we are extracting from
+ std::string localSymbolsCachePath = path;
+ if ( cache->hasLocalSymbolsInfoFile() ) {
+ // On new caches, the locals come from a new subCache file
+ if ( endsWith(localSymbolsCachePath, ".development") )
+ localSymbolsCachePath.resize(localSymbolsCachePath.size() - strlen(".development"));
+ localSymbolsCachePath += ".symbols";
+ }
+
+ std::optional<MappedCache> localSymbolsMappedCache = mapCacheFile(localSymbolsCachePath.c_str(), 0, nullptr, true);
+ if ( localSymbolsMappedCache.has_value() && cache->hasLocalSymbolsInfoFile() ) {
+ // Validate the UUID of the symbols file
+ const DyldSharedCache* subCache = localSymbolsMappedCache.value().dyldCache;
+
+ if ( memcmp(subCache->header.uuid, cache->header.symbolFileUUID, 16) != 0 ) {
+ uuid_string_t expectedUUIDString;
+ uuid_unparse_upper(cache->header.symbolFileUUID, expectedUUIDString);
+ uuid_string_t foundUUIDString;
+ uuid_unparse_upper(subCache->header.uuid, foundUUIDString);
+ fprintf(stderr, "Error: Symbols subCache UUID mismatch. Expected %s, got %s\n", expectedUUIDString, foundUUIDString);
+ return {};
+ }
+ }
+
+ CacheFiles cacheFiles;
+ cacheFiles.caches = std::move(caches);
+ cacheFiles.cacheBuffer = (vm_address_t)cacheFiles.caches.front().dyldCache;
+ cacheFiles.allocatedBufferSize = (vm_size_t)cacheFiles.caches.front().vmSize;
+ cacheFiles.localSymbolsCache = localSymbolsMappedCache;
+ return cacheFiles;
+}
+
+struct seg_info
+{
+ seg_info(const char* n, uint64_t o, uint64_t s)
+ : segName(n), offset(o), sizem(s) { }
+ const char* segName;
+ uint64_t offset;
+ uint64_t sizem;
+};
+
+class CStringHash {
+public:
+ size_t operator()(const char* __s) const {
+ size_t __h = 0;
+ for ( ; *__s; ++__s)
+ __h = 5 * __h + *__s;
+ return __h;
+ };
+};
+class CStringEquals {
+public:
+ bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); }
+};
+typedef std::unordered_map<const char*, std::vector<seg_info>, CStringHash, CStringEquals> NameToSegments;
+
+// Filter to find individual symbol re-exports in trie
+class NotReExportSymbol {
+public:
+ NotReExportSymbol(const std::set<int> &rd) :_reexportDeps(rd) {}
+ bool operator()(const ExportInfoTrie::Entry &entry) const {
+ return isSymbolReExport(entry);
+ }
+private:
+ bool isSymbolReExport(const ExportInfoTrie::Entry &entry) const {
+ if ( (entry.info.flags & EXPORT_SYMBOL_FLAGS_KIND_MASK) != EXPORT_SYMBOL_FLAGS_KIND_REGULAR )
+ return true;
+ if ( (entry.info.flags & EXPORT_SYMBOL_FLAGS_REEXPORT) == 0 )
+ return true;
+ // If the symbol comes from a dylib that is re-exported, this is not an individual symbol re-export
+ if ( _reexportDeps.count((int)entry.info.other) != 0 )
+ return true;
+ return false;
+ }
+ const std::set<int> &_reexportDeps;
+};
+
+template <typename P>
+struct LoadCommandInfo {
+};
+
+template <typename A>
+class LinkeditOptimizer {
+ typedef typename A::P P;
+ typedef typename A::P::E E;
+ typedef typename A::P::uint_t pint_t;
+
+private:
+ const uint8_t* linkeditBaseAddress = nullptr;
+ macho_segment_command<P>* linkEditSegCmd = nullptr;
+ symtab_command* symtab = nullptr;
+ dysymtab_command* dynamicSymTab = nullptr;
+ linkedit_data_command* functionStarts = nullptr;
+ linkedit_data_command* dataInCode = nullptr;
+ uint32_t exportsTrieOffset = 0;
+ uint32_t exportsTrieSize = 0;
+ std::set<int> reexportDeps;
+
+public:
+
+ void optimize_loadcommands(dyld3::MachOAnalyzer* mh, const DyldSharedCache* dyldCache)
+ {
+ // update header flags
+ mh->flags &= 0x7FFFFFFF; // remove in-cache bit
+
+ // update load commands
+ __block uint64_t cumulativeFileSize = 0;
+ __block int depIndex = 0;
+ Diagnostics diag;
+ mh->forEachLoadCommand(diag, ^(const load_command* cmd, bool &stop) {
+ switch ( cmd->cmd ) {
+ case macho_segment_command<P>::CMD: {
+ auto segCmd = (macho_segment_command<P>*)cmd;
+ if ( strcmp(segCmd->segname(), "__LINKEDIT") == 0 ) {
+ linkEditSegCmd = segCmd;
+ linkeditBaseAddress = (uint8_t*)dyldCache + (segCmd->vmaddr() - dyldCache->unslidLoadAddress());
+ // The dataoff field in load commands is relative to the start of the file, so subtract the file offset
+ // here to account for that
+ linkeditBaseAddress -= segCmd->fileoff();
+ }
+ segCmd->set_fileoff(cumulativeFileSize);
+ segCmd->set_filesize(segCmd->vmsize());
+
+ auto const sectionsStart = (macho_section<P>*)((char*)segCmd + sizeof(macho_segment_command<P>));
+ auto const sectionsEnd = §ionsStart[segCmd->nsects()];
+ for (auto sect = sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( sect->offset() != 0 ) {
+ sect->set_offset((uint32_t)(cumulativeFileSize + sect->addr() - segCmd->vmaddr()));
+ }
+ }
+ cumulativeFileSize += segCmd->filesize();
+ } break;
+ case LC_DYLD_INFO_ONLY: {
+ // zero out all dyld info. lldb only uses symbol table
+ auto dyldInfo = (dyld_info_command*)cmd;
+ exportsTrieOffset = dyldInfo->export_off;
+ exportsTrieSize = dyldInfo->export_size;
+ dyldInfo->rebase_off = 0;
+ dyldInfo->rebase_size = 0;
+ dyldInfo->bind_off = 0;
+ dyldInfo->bind_size = 0;
+ dyldInfo->weak_bind_off = 0;
+ dyldInfo->weak_bind_size = 0;
+ dyldInfo->lazy_bind_off = 0;
+ dyldInfo->lazy_bind_size = 0;
+ dyldInfo->export_off = 0;
+ dyldInfo->export_size = 0;
+ } break;
+ case LC_DYLD_EXPORTS_TRIE: {
+ // don't put export trie into extracted dylib. lldb only uses symbol table
+ linkedit_data_command* exportsTrie = (linkedit_data_command*)cmd;
+ exportsTrieOffset = exportsTrie->dataoff;
+ exportsTrieSize = exportsTrie->datasize;
+ exportsTrie->dataoff = 0;
+ exportsTrie->datasize = 0;
+ } break;
+ case LC_SYMTAB:
+ symtab = (symtab_command*)cmd;
+ break;
+ case LC_DYSYMTAB:
+ dynamicSymTab = (dysymtab_command*)cmd;
+ break;
+ case LC_FUNCTION_STARTS:
+ functionStarts = (linkedit_data_command*)cmd;
+ break;
+ case LC_DATA_IN_CODE:
+ dataInCode = (linkedit_data_command*)cmd;
+ break;
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ case LC_LOAD_UPWARD_DYLIB:
+ depIndex++;
+ if ( cmd->cmd == LC_REEXPORT_DYLIB ) {
+ reexportDeps.insert(depIndex);
+ }
+ break;
+ default:
+ break;
+ }
+ });
+
+ mh->removeLoadCommand(diag, ^(const load_command* cmd, bool& remove, bool &stop) {
+ switch ( cmd->cmd ) {
+ case LC_SEGMENT_SPLIT_INFO:
+ // <rdar://problem/23212513> dylibs iOS 9 dyld caches have bogus LC_SEGMENT_SPLIT_INFO
+ remove = true;
+ stop = true;
+ break;
+ default:
+ break;
+ }
+ });
+}
+
+ int optimize_linkedit(std::vector<uint8_t> &new_linkedit_data, uint64_t textOffsetInCache,
+ std::optional<const DyldSharedCache*> localSymbolsCache)
+ {
+ // rebuild symbol table
+ if ( (linkEditSegCmd == nullptr) || (linkeditBaseAddress == nullptr) ) {
+ fprintf(stderr, "__LINKEDIT not found\n");
+ return -1;
+ }
+ if ( symtab == nullptr ) {
+ fprintf(stderr, "LC_SYMTAB not found\n");
+ return -1;
+ }
+ if ( dynamicSymTab == nullptr ) {
+ fprintf(stderr, "LC_DYSYMTAB not found\n");
+ return -1;
+ }
+
+ const uint64_t newFunctionStartsOffset = new_linkedit_data.size();
+ uint32_t functionStartsSize = 0;
+ if ( functionStarts != NULL ) {
+ // copy function starts from original cache file to new mapped dylib file
+ functionStartsSize = functionStarts->datasize;
+ new_linkedit_data.insert(new_linkedit_data.end(),
+ linkeditBaseAddress + functionStarts->dataoff,
+ linkeditBaseAddress + functionStarts->dataoff + functionStartsSize);
+ }
+
+ // pointer align
+ while ((linkEditSegCmd->fileoff() + new_linkedit_data.size()) % sizeof(pint_t))
+ new_linkedit_data.push_back(0);
+
+ const uint64_t newDataInCodeOffset = new_linkedit_data.size();
+ uint32_t dataInCodeSize = 0;
+ if ( dataInCode != NULL ) {
+ // copy data-in-code info from original cache file to new mapped dylib file
+ dataInCodeSize = dataInCode->datasize;
+ new_linkedit_data.insert(new_linkedit_data.end(),
+ linkeditBaseAddress + dataInCode->dataoff,
+ linkeditBaseAddress + dataInCode->dataoff + dataInCodeSize);
+ }
+
+ std::vector<ExportInfoTrie::Entry> exports;
+ if ( exportsTrieSize != 0 ) {
+ const uint8_t* exportsStart = linkeditBaseAddress + exportsTrieOffset;
+ const uint8_t* exportsEnd = &exportsStart[exportsTrieSize];
+ ExportInfoTrie::parseTrie(exportsStart, exportsEnd, exports);
+ exports.erase(std::remove_if(exports.begin(), exports.end(), NotReExportSymbol(reexportDeps)), exports.end());
+ }
+
+ __block macho_nlist<P>* localNlists = nullptr;
+ __block uint32_t localNlistCount = 0;
+ if ( localSymbolsCache.has_value() ) {
+ const DyldSharedCache* localsCache = *localSymbolsCache;
+
+ macho_nlist<P>* allLocalNlists = (macho_nlist<P>*)localsCache->getLocalNlistEntries();
+ localsCache->forEachLocalSymbolEntry(^(uint64_t dylibCacheVMOffset, uint32_t nlistStartIndex, uint32_t nlistCount, bool& stop){
+ if (dylibCacheVMOffset == textOffsetInCache) {
+ localNlists = &allLocalNlists[nlistStartIndex];
+ localNlistCount = nlistCount;
+ stop = true;
+ }
+ });
+ }
+
+ // compute number of symbols in new symbol table
+ const macho_nlist<P>* mergedSymTabStart = (macho_nlist<P>*)(linkeditBaseAddress + symtab->symoff);
+ const macho_nlist<P>* const mergedSymTabend = &mergedSymTabStart[symtab->nsyms];
+ uint32_t newSymCount = symtab->nsyms;
+ if ( localNlistCount != 0 ) {
+ // if we are recombining with unmapped locals, recompute new total size
+ newSymCount = localNlistCount + dynamicSymTab->nextdefsym + dynamicSymTab->nundefsym;
+ }
+
+ // add room for N_INDR symbols for re-exported symbols
+ newSymCount += exports.size();
+
+ // copy symbol entries and strings from original cache file to new mapped dylib file
+ const char* mergedStringPoolStart = (const char*)linkeditBaseAddress + symtab->stroff;
+ const char* mergedStringPoolEnd = &mergedStringPoolStart[symtab->strsize];
+
+ // First count how many entries we need
+ std::vector<macho_nlist<P>> newSymTab;
+ newSymTab.reserve(newSymCount);
+ std::vector<char> newSymNames;
+
+ // first pool entry is always empty string
+ newSymNames.push_back('\0');
+
+ // local symbols are first in dylibs, if this cache has unmapped locals, insert them all first
+ uint32_t undefSymbolShift = 0;
+ if ( localNlistCount != 0 ) {
+ const DyldSharedCache* localsCache = *localSymbolsCache;
+ const char* localStrings = localsCache->getLocalStrings();
+ undefSymbolShift = localNlistCount - dynamicSymTab->nlocalsym;
+ // update load command to reflect new count of locals
+ dynamicSymTab->ilocalsym = (uint32_t)newSymTab.size();
+ dynamicSymTab->nlocalsym = localNlistCount;
+ // copy local symbols
+ for (uint32_t i=0; i < localNlistCount; ++i) {
+ const char* localName = &localStrings[localNlists[i].n_strx()];
+ if ( localName > localStrings + localsCache->getLocalStringsSize() )
+ localName = "<corrupt local symbol name>";
+ macho_nlist<P> t = localNlists[i];
+ t.set_n_strx((uint32_t)newSymNames.size());
+ newSymNames.insert(newSymNames.end(),
+ localName,
+ localName + (strlen(localName) + 1));
+ newSymTab.push_back(t);
+ }
+ // now start copying symbol table from start of externs instead of start of locals
+ mergedSymTabStart = &mergedSymTabStart[dynamicSymTab->iextdefsym];
+ }
+ // copy full symbol table from cache (skipping locals if they where elsewhere)
+ for (const macho_nlist<P>* s = mergedSymTabStart; s != mergedSymTabend; ++s) {
+ macho_nlist<P> t = *s;
+ t.set_n_strx((uint32_t)newSymNames.size());
+ const char* symName = &mergedStringPoolStart[s->n_strx()];
+ if ( symName > mergedStringPoolEnd )
+ symName = "<corrupt symbol name>";
+ newSymNames.insert(newSymNames.end(),
+ symName,
+ symName + (strlen(symName) + 1));
+ newSymTab.push_back(t);
+ }
+ // <rdar://problem/16529213> recreate N_INDR symbols in extracted dylibs for debugger
+ for (std::vector<ExportInfoTrie::Entry>::iterator it = exports.begin(); it != exports.end(); ++it) {
+ macho_nlist<P> t;
+ memset(&t, 0, sizeof(t));
+ t.set_n_strx((uint32_t)newSymNames.size());
+ t.set_n_type(N_INDR | N_EXT);
+ t.set_n_sect(0);
+ t.set_n_desc(0);
+ newSymNames.insert(newSymNames.end(),
+ it->name.c_str(),
+ it->name.c_str() + (it->name.size() + 1));
+ const char* importName = it->info.importName.c_str();
+ if ( *importName == '\0' )
+ importName = it->name.c_str();
+ t.set_n_value(newSymNames.size());
+ newSymNames.insert(newSymNames.end(),
+ importName,
+ importName + (strlen(importName) + 1));
+ newSymTab.push_back(t);
+ }
+
+ if ( newSymCount != newSymTab.size() ) {
+ fprintf(stderr, "symbol count miscalculation\n");
+ return -1;
+ }
+
+ //const uint64_t newStringPoolOffset = newIndSymTabOffset + dynamicSymTab->nindirectsyms()*sizeof(uint32_t);
+ //macho_nlist<P>* const newSymTabStart = (macho_nlist<P>*)(((uint8_t*)mh) + newSymTabOffset);
+ //char* const newStringPoolStart = (char*)mh + newStringPoolOffset;
+
+ // pointer align
+ while ((linkEditSegCmd->fileoff() + new_linkedit_data.size()) % sizeof(pint_t))
+ new_linkedit_data.push_back(0);
+
+ const uint64_t newSymTabOffset = new_linkedit_data.size();
+
+ // Copy sym tab
+ for (macho_nlist<P>& sym : newSymTab) {
+ uint8_t symData[sizeof(macho_nlist<P>)];
+ memcpy(&symData, &sym, sizeof(sym));
+ new_linkedit_data.insert(new_linkedit_data.end(), &symData[0], &symData[sizeof(macho_nlist<P>)]);
+ }
+
+ const size_t newIndSymTabOffset = new_linkedit_data.size();
+
+ // Copy (and adjust) indirect symbol table
+ const uint32_t* mergedIndSymTab = (uint32_t*)(linkeditBaseAddress + dynamicSymTab->indirectsymoff);
+ new_linkedit_data.insert(new_linkedit_data.end(),
+ (char*)mergedIndSymTab,
+ (char*)(mergedIndSymTab + dynamicSymTab->nindirectsyms));
+ if ( undefSymbolShift != 0 ) {
+ uint32_t* newIndSymTab = (uint32_t*)&new_linkedit_data[newIndSymTabOffset];
+ for (uint32_t i=0; i < dynamicSymTab->nindirectsyms; ++i) {
+ newIndSymTab[i] += undefSymbolShift;
+ }
+ }
+ const uint64_t newStringPoolOffset = new_linkedit_data.size();
+
+ // pointer align string pool size
+ while (newSymNames.size() % sizeof(pint_t))
+ newSymNames.push_back('\0');
+
+ new_linkedit_data.insert(new_linkedit_data.end(), newSymNames.begin(), newSymNames.end());
+
+ // update load commands
+ if ( functionStarts != NULL ) {
+ functionStarts->dataoff = (uint32_t)(newFunctionStartsOffset + linkEditSegCmd->fileoff());
+ functionStarts->datasize = functionStartsSize;
+ }
+ if ( dataInCode != NULL ) {
+ dataInCode->dataoff = (uint32_t)(newDataInCodeOffset + linkEditSegCmd->fileoff());
+ dataInCode->datasize = dataInCodeSize;
+ }
+
+ symtab->nsyms = newSymCount;
+ symtab->symoff = (uint32_t)(newSymTabOffset + linkEditSegCmd->fileoff());
+ symtab->stroff = (uint32_t)(newStringPoolOffset + linkEditSegCmd->fileoff());
+ symtab->strsize = (uint32_t)newSymNames.size();
+ dynamicSymTab->extreloff = 0;
+ dynamicSymTab->nextrel = 0;
+ dynamicSymTab->locreloff = 0;
+ dynamicSymTab->nlocrel = 0;
+ dynamicSymTab->indirectsymoff = (uint32_t)(newIndSymTabOffset + linkEditSegCmd->fileoff());
+ linkEditSegCmd->set_filesize(symtab->stroff + symtab->strsize - linkEditSegCmd->fileoff());
+ linkEditSegCmd->set_vmsize((linkEditSegCmd->filesize() + 4095) & (-4096));
+
+ return 0;
+ }
+
+};
+
+static void make_dirs(const char* file_path)
+{
+ //printf("make_dirs(%s)\n", file_path);
+ char dirs[strlen(file_path)+1];
+ strcpy(dirs, file_path);
+ char* lastSlash = strrchr(dirs, '/');
+ if ( lastSlash == NULL )
+ return;
+ lastSlash[1] = '\0';
+ struct stat stat_buf;
+ if ( stat(dirs, &stat_buf) != 0 ) {
+ char* afterSlash = &dirs[1];
+ char* slash;
+ while ( (slash = strchr(afterSlash, '/')) != NULL ) {
+ *slash = '\0';
+ ::mkdir(dirs, S_IRWXU | S_IRGRP|S_IXGRP | S_IROTH|S_IXOTH);
+ //printf("mkdir(%s)\n", dirs);
+ *slash = '/';
+ afterSlash = slash+1;
+ }
+ }
+}
+
+
+
+template <typename A>
+void dylib_maker(const void* mapped_cache, std::optional<const DyldSharedCache*> localSymbolsCache,
+ std::vector<uint8_t> &dylib_data, const std::vector<seg_info>& segments) {
+
+ size_t additionalSize = 0;
+ for(std::vector<seg_info>::const_iterator it=segments.begin(); it != segments.end(); ++it) {
+ if ( strcmp(it->segName, "__LINKEDIT") != 0 )
+ additionalSize += it->sizem;
+ }
+
+ std::vector<uint8_t> new_dylib_data;
+ new_dylib_data.reserve(additionalSize);
+
+ // Write regular segments into the buffer
+ uint64_t textOffsetInCache = 0;
+ for( std::vector<seg_info>::const_iterator it=segments.begin(); it != segments.end(); ++it) {
+
+ if(strcmp(it->segName, "__TEXT") == 0 )
+ textOffsetInCache = it->offset;
+
+ //printf("segName=%s, offset=0x%llX, size=0x%0llX\n", it->segName, it->offset, it->sizem);
+ // Copy all but the __LINKEDIT. It will be copied later during the optimizer in to a temporary buffer but it would
+ // not be efficient to copy it all now for each dylib.
+ if (strcmp(it->segName, "__LINKEDIT") == 0 )
+ continue;
+ std::copy(((uint8_t*)mapped_cache)+it->offset, ((uint8_t*)mapped_cache)+it->offset+it->sizem, std::back_inserter(new_dylib_data));
+ }
+
+ // optimize linkedit
+ std::vector<uint8_t> new_linkedit_data;
+ new_linkedit_data.reserve(1 << 20);
+
+ LinkeditOptimizer<A> linkeditOptimizer;
+ dyld3::MachOAnalyzer* mh = (dyld3::MachOAnalyzer*)&new_dylib_data.front();
+ linkeditOptimizer.optimize_loadcommands(mh, ((DyldSharedCache*)mapped_cache));
+ linkeditOptimizer.optimize_linkedit(new_linkedit_data, textOffsetInCache, localSymbolsCache);
+
+ new_dylib_data.insert(new_dylib_data.end(), new_linkedit_data.begin(), new_linkedit_data.end());
+
+ // Page align file
+ while (new_dylib_data.size() % 4096)
+ new_dylib_data.push_back(0);
+
+ dylib_data.insert(dylib_data.end(), new_dylib_data.begin(), new_dylib_data.end());
+}
+
+typedef __typeof(dylib_maker<x86>) dylib_maker_func;
+typedef void (^progress_block)(unsigned current, unsigned total);
+
+struct SharedCacheExtractor;
+struct SharedCacheDylibExtractor {
+ SharedCacheDylibExtractor(const char* name, std::vector<seg_info> segInfo)
+ : name(name), segInfo(segInfo) { }
+
+ void extractCache(SharedCacheExtractor& context);
+
+ const char* name;
+ const std::vector<seg_info> segInfo;
+ int result = 0;
+};
+
+struct SharedCacheExtractor {
+ SharedCacheExtractor(const NameToSegments& map,
+ const char* extraction_root_path,
+ dylib_maker_func* dylib_create_func,
+ const void* mapped_cache,
+ std::optional<const DyldSharedCache*> localSymbolsCache,
+ progress_block progress)
+ : map(map), extraction_root_path(extraction_root_path),
+ dylib_create_func(dylib_create_func), mapped_cache(mapped_cache),
+ localSymbolsCache(localSymbolsCache),
+ progress(progress) {
+
+ extractors.reserve(map.size());
+ for (auto it : map)
+ extractors.emplace_back(it.first, it.second);
+
+ // Limit the number of open files. 16 seems to give better performance than higher numbers.
+ sema = dispatch_semaphore_create(16);
+ }
+ int extractCaches();
+
+ static void extractCache(void *ctx, size_t i);
+
+ const NameToSegments& map;
+ std::vector<SharedCacheDylibExtractor> extractors;
+ dispatch_semaphore_t sema;
+ const char* extraction_root_path;
+ dylib_maker_func* dylib_create_func;
+ const void* mapped_cache;
+ std::optional<const DyldSharedCache*> localSymbolsCache;
+ progress_block progress;
+ std::atomic_int count = { 0 };
+};
+
+int SharedCacheExtractor::extractCaches() {
+ dispatch_queue_t process_queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_LOW, 0);
+ dispatch_apply_f(map.size(), process_queue,
+ this, extractCache);
+
+ int result = 0;
+ for (const SharedCacheDylibExtractor& extractor : extractors) {
+ if (extractor.result != 0) {
+ result = extractor.result;
+ break;
+ }
+ }
+ return result;
+}
+
+void SharedCacheExtractor::extractCache(void *ctx, size_t i) {
+ SharedCacheExtractor& context = *(SharedCacheExtractor*)ctx;
+ dispatch_semaphore_wait(context.sema, DISPATCH_TIME_FOREVER);
+ context.extractors[i].extractCache(context);
+ dispatch_semaphore_signal(context.sema);
+}
+
+void SharedCacheDylibExtractor::extractCache(SharedCacheExtractor &context) {
+
+ char dylib_path[PATH_MAX];
+ strcpy(dylib_path, context.extraction_root_path);
+ strcat(dylib_path, "/");
+ strcat(dylib_path, name);
+
+ //printf("%s with %lu segments\n", dylib_path, it->second.size());
+ // make sure all directories in this path exist
+ make_dirs(dylib_path);
+
+ // open file, create if does not already exist
+ int fd = ::open(dylib_path, O_CREAT | O_TRUNC | O_EXLOCK | O_RDWR, 0644);
+ if ( fd == -1 ) {
+ fprintf(stderr, "can't open or create dylib file %s, errnor=%d\n", dylib_path, errno);
+ result = -1;
+ return;
+ }
+
+ std::vector<uint8_t> vec;
+ context.dylib_create_func(context.mapped_cache, context.localSymbolsCache, vec, segInfo);
+ context.progress(context.count++, (unsigned)context.map.size());
+
+ // Write file data
+ if( write(fd, &vec.front(), vec.size()) == -1) {
+ fprintf(stderr, "error writing, errnor=%d\n", errno);
+ result = -1;
+ }
+
+ close(fd);
+}
+
+int dyld_shared_cache_extract_dylibs_progress(const char* shared_cache_file_path, const char* extraction_root_path,
+ progress_block progress)
+{
+ CacheFiles mappedCaches = mapCacheFiles(shared_cache_file_path);
+ if ( mappedCaches.caches.empty() )
+ return -1;
+
+ const DyldSharedCache* mapped_cache = mappedCaches.caches.front().dyldCache;
+
+ // instantiate arch specific dylib maker
+ dylib_maker_func* dylib_create_func = nullptr;
+ if ( strcmp((char*)mapped_cache, "dyld_v1 i386") == 0 )
+ dylib_create_func = dylib_maker<x86>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 x86_64") == 0 )
+ dylib_create_func = dylib_maker<x86_64>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 x86_64h") == 0 )
+ dylib_create_func = dylib_maker<x86_64>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 armv5") == 0 )
+ dylib_create_func = dylib_maker<arm>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 armv6") == 0 )
+ dylib_create_func = dylib_maker<arm>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 armv7") == 0 )
+ dylib_create_func = dylib_maker<arm>;
+ else if ( strncmp((char*)mapped_cache, "dyld_v1 armv7", 14) == 0 )
+ dylib_create_func = dylib_maker<arm>;
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 arm64") == 0 )
+ dylib_create_func = dylib_maker<arm64>;
+#if SUPPORT_ARCH_arm64e
+ else if ( strcmp((char*)mapped_cache, "dyld_v1 arm64e") == 0 )
+ dylib_create_func = dylib_maker<arm64>;
+#endif
+#if SUPPORT_ARCH_arm64_32
+ else if ( strcmp((char*)mapped_cache, "dyld_v1arm64_32") == 0 )
+ dylib_create_func = dylib_maker<arm64_32>;
+#endif
+ else {
+ fprintf(stderr, "Error: unrecognized dyld shared cache magic.\n");
+ mappedCaches.unload();
+ return -1;
+ }
+
+ // iterate through all images in cache and build map of dylibs and segments
+ __block NameToSegments map;
+ int result = 0;
+
+ if ( mapped_cache->mappedSize() == 0 ) {
+ mappedCaches.unload();
+ return result;
+ }
+
+ mapped_cache->forEachImage(^(const mach_header *mh, const char *installName) {
+ ((const dyld3::MachOAnalyzer*)mh)->forEachSegment(^(const dyld3::MachOAnalyzer::SegmentInfo &info, bool &stop) {
+ map[installName].push_back(seg_info(info.segName, info.vmAddr - mapped_cache->unslidLoadAddress(), info.vmSize));
+ });
+ });
+
+ if( result != 0 ) {
+ fprintf(stderr, "Error: dyld_shared_cache_iterate_segments_with_slide failed.\n");
+ mappedCaches.unload();
+ return result;
+ }
+
+ // for each dylib instantiate a dylib file
+ std::optional<const DyldSharedCache*> localSymbolsCache;
+ if ( mappedCaches.localSymbolsCache.has_value() )
+ localSymbolsCache = mappedCaches.localSymbolsCache->dyldCache;
+ SharedCacheExtractor extractor(map, extraction_root_path, dylib_create_func,
+ mapped_cache, localSymbolsCache, progress);
+ result = extractor.extractCaches();
+
+ mappedCaches.unload();
+ return result;
+}
+
+
+
+int dyld_shared_cache_extract_dylibs(const char* shared_cache_file_path, const char* extraction_root_path)
+{
+ return dyld_shared_cache_extract_dylibs_progress(shared_cache_file_path, extraction_root_path,
+ ^(unsigned , unsigned) {} );
+}
+
+
+#if 0
+// test program
+#include <stdio.h>
+#include <stddef.h>
+#include <dlfcn.h>
+
+
+typedef int (*extractor_proc)(const char* shared_cache_file_path, const char* extraction_root_path,
+ void (^progress)(unsigned current, unsigned total));
+
+int main(int argc, const char* argv[])
+{
+ if ( argc != 3 ) {
+ fprintf(stderr, "usage: dsc_extractor <path-to-cache-file> <path-to-device-dir>\n");
+ return 1;
+ }
+
+ //void* handle = dlopen("/Volumes/my/src/dyld/build/Debug/dsc_extractor.bundle", RTLD_LAZY);
+ void* handle = dlopen("/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/usr/lib/dsc_extractor.bundle", RTLD_LAZY);
+ if ( handle == NULL ) {
+ fprintf(stderr, "dsc_extractor.bundle could not be loaded\n");
+ return 1;
+ }
+
+ extractor_proc proc = (extractor_proc)dlsym(handle, "dyld_shared_cache_extract_dylibs_progress");
+ if ( proc == NULL ) {
+ fprintf(stderr, "dsc_extractor.bundle did not have dyld_shared_cache_extract_dylibs_progress symbol\n");
+ return 1;
+ }
+
+ int result = (*proc)(argv[1], argv[2], ^(unsigned c, unsigned total) { printf("%d/%d\n", c, total); } );
+ fprintf(stderr, "dyld_shared_cache_extract_dylibs_progress() => %d\n", result);
+ return 0;
+}
+
+
+#endif
+
+
+
+