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--- /dev/null
+++ dyld/dyld-551.4/dyld3/SharedCacheRuntime.cpp
@@ -0,0 +1,648 @@
+/*
+ * 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 <stdint.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/syscall.h>
+#include <sys/syslog.h>
+#include <sys/sysctl.h>
+#include <sys/mman.h>
+#include <mach/mach.h>
+#include <mach-o/fat.h>
+#include <mach-o/loader.h>
+#include <mach-o/ldsyms.h>
+#include <mach/shared_region.h>
+#include <mach/mach.h>
+#include <Availability.h>
+#include <TargetConditionals.h>
+
+#include "dyld_cache_format.h"
+#include "SharedCacheRuntime.h"
+#include "LaunchCache.h"
+#include "LaunchCacheFormat.h"
+#include "Loading.h"
+
+#define ENABLE_DYLIBS_TO_OVERRIDE_CACHE_SIZE 1024
+
+// should be in mach/shared_region.h
+extern "C" int __shared_region_check_np(uint64_t* startaddress);
+extern "C" int __shared_region_map_and_slide_np(int fd, uint32_t count, const shared_file_mapping_np mappings[], long slide, const dyld_cache_slide_info2* slideInfo, size_t slideInfoSize);
+
+
+namespace dyld {
+ extern int my_stat(const char* path, struct stat* buf);
+ extern int my_open(const char* path, int flag, int other);
+ extern void log(const char*, ...);
+}
+
+
+namespace dyld3 {
+
+
+struct CacheInfo
+{
+ int fd;
+ shared_file_mapping_np mappings[3];
+ uint64_t slideInfoAddressUnslid;
+ size_t slideInfoSize;
+ uint64_t cachedDylibsGroupUnslid;
+ uint64_t sharedRegionStart;
+ uint64_t sharedRegionSize;
+ uint64_t maxSlide;
+};
+
+
+
+
+#if __i386__
+ #define ARCH_NAME "i386"
+ #define ARCH_CACHE_MAGIC "dyld_v1 i386"
+#elif __x86_64__
+ #define ARCH_NAME "x86_64"
+ #define ARCH_CACHE_MAGIC "dyld_v1 x86_64"
+ #define ARCH_NAME_H "x86_64h"
+ #define ARCH_CACHE_MAGIC_H "dyld_v1 x86_64h"
+#elif __ARM_ARCH_7K__
+ #define ARCH_NAME "armv7k"
+ #define ARCH_CACHE_MAGIC "dyld_v1 armv7k"
+#elif __ARM_ARCH_7A__
+ #define ARCH_NAME "armv7"
+ #define ARCH_CACHE_MAGIC "dyld_v1 armv7"
+#elif __ARM_ARCH_7S__
+ #define ARCH_NAME "armv7s"
+ #define ARCH_CACHE_MAGIC "dyld_v1 armv7s"
+#elif __arm64e__
+ #define ARCH_NAME "arm64e"
+ #define ARCH_CACHE_MAGIC "dyld_v1 arm64e"
+#elif __arm64__
+ #define ARCH_NAME "arm64"
+ #define ARCH_CACHE_MAGIC "dyld_v1 arm64"
+#endif
+
+
+
+static void rebaseChain(uint8_t* pageContent, uint16_t startOffset, uintptr_t slideAmount, const dyld_cache_slide_info2* slideInfo)
+{
+ const uintptr_t deltaMask = (uintptr_t)(slideInfo->delta_mask);
+ const uintptr_t valueMask = ~deltaMask;
+ const uintptr_t valueAdd = (uintptr_t)(slideInfo->value_add);
+ const unsigned deltaShift = __builtin_ctzll(deltaMask) - 2;
+
+ uint32_t pageOffset = startOffset;
+ uint32_t delta = 1;
+ while ( delta != 0 ) {
+ uint8_t* loc = pageContent + pageOffset;
+ uintptr_t rawValue = *((uintptr_t*)loc);
+ delta = (uint32_t)((rawValue & deltaMask) >> deltaShift);
+ uintptr_t value = (rawValue & valueMask);
+ if ( value != 0 ) {
+ value += valueAdd;
+ value += slideAmount;
+ }
+ *((uintptr_t*)loc) = value;
+ //dyld::log(" pageOffset=0x%03X, loc=%p, org value=0x%08llX, new value=0x%08llX, delta=0x%X\n", pageOffset, loc, (uint64_t)rawValue, (uint64_t)value, delta);
+ pageOffset += delta;
+ }
+}
+
+
+static void getCachePath(const SharedCacheOptions& options, size_t pathBufferSize, char pathBuffer[])
+{
+ // set cache dir
+ if ( options.cacheDirOverride != nullptr ) {
+ strlcpy(pathBuffer, options.cacheDirOverride, pathBufferSize);
+ }
+ else {
+#if __IPHONE_OS_VERSION_MIN_REQUIRED
+ strlcpy(pathBuffer, IPHONE_DYLD_SHARED_CACHE_DIR, sizeof(IPHONE_DYLD_SHARED_CACHE_DIR));
+#else
+ strlcpy(pathBuffer, MACOSX_DYLD_SHARED_CACHE_DIR, sizeof(MACOSX_DYLD_SHARED_CACHE_DIR));
+#endif
+ }
+
+ // append file component of cache file
+ if ( pathBuffer[strlen(pathBuffer)-1] != '/' )
+ strlcat(pathBuffer, "/", pathBufferSize);
+#if __x86_64__ && !__IPHONE_OS_VERSION_MIN_REQUIRED
+ if ( options.useHaswell ) {
+ size_t len = strlen(pathBuffer);
+ struct stat haswellStatBuf;
+ strlcat(pathBuffer, DYLD_SHARED_CACHE_BASE_NAME ARCH_NAME_H, pathBufferSize);
+ if ( dyld::my_stat(pathBuffer, &haswellStatBuf) == 0 )
+ return;
+ // no haswell cache file, use regular x86_64 cache
+ pathBuffer[len] = '\0';
+ }
+#endif
+ strlcat(pathBuffer, DYLD_SHARED_CACHE_BASE_NAME ARCH_NAME, pathBufferSize);
+
+#if __IPHONE_OS_VERSION_MIN_REQUIRED && !TARGET_IPHONE_SIMULATOR
+ // use .development cache if it exists
+ struct stat enableStatBuf;
+ struct stat devCacheStatBuf;
+ struct stat optCacheStatBuf;
+ bool enableFileExists = (dyld::my_stat(IPHONE_DYLD_SHARED_CACHE_DIR "enable-dylibs-to-override-cache", &enableStatBuf) == 0);
+ bool devCacheExists = (dyld::my_stat(IPHONE_DYLD_SHARED_CACHE_DIR DYLD_SHARED_CACHE_BASE_NAME ARCH_NAME DYLD_SHARED_CACHE_DEVELOPMENT_EXT, &devCacheStatBuf) == 0);
+ bool optCacheExists = (dyld::my_stat(IPHONE_DYLD_SHARED_CACHE_DIR DYLD_SHARED_CACHE_BASE_NAME ARCH_NAME, &optCacheStatBuf) == 0);
+ if ( (enableFileExists && (enableStatBuf.st_size < ENABLE_DYLIBS_TO_OVERRIDE_CACHE_SIZE) && devCacheExists) || !optCacheExists )
+ strlcat(pathBuffer, DYLD_SHARED_CACHE_DEVELOPMENT_EXT, pathBufferSize);
+#endif
+
+}
+
+
+int openSharedCacheFile(const SharedCacheOptions& options, SharedCacheLoadInfo* results)
+{
+ getCachePath(options, sizeof(results->path), results->path);
+ return dyld::my_open(results->path, O_RDONLY, 0);
+}
+
+static bool validMagic(const SharedCacheOptions& options, const DyldSharedCache* cache)
+{
+ if ( strcmp(cache->header.magic, ARCH_CACHE_MAGIC) == 0 )
+ return true;
+
+#if __x86_64__
+ if ( options.useHaswell ) {
+ if ( strcmp(cache->header.magic, ARCH_CACHE_MAGIC_H) == 0 )
+ return true;
+ }
+#endif
+ return false;
+}
+
+
+static bool validPlatform(const SharedCacheOptions& options, const DyldSharedCache* cache)
+{
+ // grandfather in old cache that does not have platform in header
+ if ( cache->header.mappingOffset < 0xE0 )
+ return true;
+
+ if ( cache->header.platform != (uint32_t)MachOParser::currentPlatform() )
+ return false;
+
+#if TARGET_IPHONE_SIMULATOR
+ if ( cache->header.simulator == 0 )
+ return false;
+#else
+ if ( cache->header.simulator != 0 )
+ return false;
+#endif
+
+ return true;
+}
+
+
+static void verboseSharedCacheMappings(const shared_file_mapping_np mappings[3])
+{
+ for (int i=0; i < 3; ++i) {
+ dyld::log(" 0x%08llX->0x%08llX init=%x, max=%x %s%s%s\n",
+ mappings[i].sfm_address, mappings[i].sfm_address+mappings[i].sfm_size-1,
+ mappings[i].sfm_init_prot, mappings[i].sfm_init_prot,
+ ((mappings[i].sfm_init_prot & VM_PROT_READ) ? "read " : ""),
+ ((mappings[i].sfm_init_prot & VM_PROT_WRITE) ? "write " : ""),
+ ((mappings[i].sfm_init_prot & VM_PROT_EXECUTE) ? "execute " : ""));
+ }
+}
+
+static bool preflightCacheFile(const SharedCacheOptions& options, SharedCacheLoadInfo* results, CacheInfo* info)
+{
+ // find and open shared cache file
+ int fd = openSharedCacheFile(options, results);
+ if ( fd == -1 ) {
+ results->errorMessage = "shared cache file cannot be opened";
+ return false;
+ }
+ struct stat cacheStatBuf;
+ if ( dyld::my_stat(results->path, &cacheStatBuf) != 0 ) {
+ results->errorMessage = "shared cache file cannot be stat()ed";
+ ::close(fd);
+ return false;
+ }
+ size_t cacheFileLength = (size_t)(cacheStatBuf.st_size);
+
+ // sanity check header and mappings
+ uint8_t firstPage[0x4000];
+ if ( ::pread(fd, firstPage, sizeof(firstPage), 0) != sizeof(firstPage) ) {
+ results->errorMessage = "shared cache header could not be read";
+ ::close(fd);
+ return false;
+ }
+ const DyldSharedCache* cache = (DyldSharedCache*)firstPage;
+ if ( !validMagic(options, cache) ) {
+ results->errorMessage = "shared cache file has wrong magic";
+ ::close(fd);
+ return false;
+ }
+ if ( !validPlatform(options, cache) ) {
+ results->errorMessage = "shared cache file is for a different platform";
+ ::close(fd);
+ return false;
+ }
+ if ( (cache->header.mappingCount != 3) || (cache->header.mappingOffset > 0x120) ) {
+ results->errorMessage = "shared cache file mappings are invalid";
+ ::close(fd);
+ return false;
+ }
+ const dyld_cache_mapping_info* const fileMappings = (dyld_cache_mapping_info*)&firstPage[cache->header.mappingOffset];
+ if ( (fileMappings[0].fileOffset != 0)
+ || ((fileMappings[0].address + fileMappings[0].size) > fileMappings[1].address)
+ || ((fileMappings[1].address + fileMappings[1].size) > fileMappings[2].address)
+ || ((fileMappings[0].fileOffset + fileMappings[0].size) != fileMappings[1].fileOffset)
+ || ((fileMappings[1].fileOffset + fileMappings[1].size) != fileMappings[2].fileOffset)
+ || ((cache->header.codeSignatureOffset + cache->header.codeSignatureSize) != cacheFileLength)
+ || (fileMappings[0].maxProt != (VM_PROT_READ|VM_PROT_EXECUTE))
+ || (fileMappings[1].maxProt != (VM_PROT_READ|VM_PROT_WRITE))
+ || (fileMappings[2].maxProt != VM_PROT_READ) ) {
+ results->errorMessage = "shared cache file mappings are invalid";
+ ::close(fd);
+ return false;
+ }
+
+ if ( cache->header.mappingOffset >= 0xF8 ) {
+ if ( (fileMappings[0].address != cache->header.sharedRegionStart) || ((fileMappings[2].address + fileMappings[2].size) > (cache->header.sharedRegionStart+cache->header.sharedRegionSize)) ) {
+ results->errorMessage = "shared cache file mapping addressses invalid";
+ ::close(fd);
+ return false;
+ }
+ }
+ else {
+ if ( (fileMappings[0].address != SHARED_REGION_BASE) || ((fileMappings[2].address + fileMappings[2].size) > (SHARED_REGION_BASE+SHARED_REGION_SIZE)) ) {
+ results->errorMessage = "shared cache file mapping addressses invalid";
+ ::close(fd);
+ return false;
+ }
+ }
+
+ // register code signature of cache file
+ fsignatures_t siginfo;
+ siginfo.fs_file_start = 0; // cache always starts at beginning of file
+ siginfo.fs_blob_start = (void*)cache->header.codeSignatureOffset;
+ siginfo.fs_blob_size = (size_t)(cache->header.codeSignatureSize);
+ int result = fcntl(fd, F_ADDFILESIGS_RETURN, &siginfo);
+ if ( result == -1 ) {
+ results->errorMessage = "code signature registration for shared cache failed";
+ ::close(fd);
+ return false;
+ }
+
+ // <rdar://problem/23188073> validate code signature covers entire shared cache
+ uint64_t codeSignedLength = siginfo.fs_file_start;
+ if ( codeSignedLength < cache->header.codeSignatureOffset ) {
+ results->errorMessage = "code signature does not cover entire shared cache file";
+ ::close(fd);
+ return false;
+ }
+ void* mappedData = ::mmap(NULL, sizeof(firstPage), PROT_READ|PROT_EXEC, MAP_PRIVATE, fd, 0);
+ if ( mappedData == MAP_FAILED ) {
+ results->errorMessage = "first page of shared cache not mmap()able";
+ ::close(fd);
+ return false;
+ }
+ if ( memcmp(mappedData, firstPage, sizeof(firstPage)) != 0 ) {
+ results->errorMessage = "first page of shared cache not mmap()able";
+ ::close(fd);
+ return false;
+ }
+ ::munmap(mappedData, sizeof(firstPage));
+
+ // fill out results
+ info->fd = fd;
+ for (int i=0; i < 3; ++i) {
+ info->mappings[i].sfm_address = fileMappings[i].address;
+ info->mappings[i].sfm_size = fileMappings[i].size;
+ info->mappings[i].sfm_file_offset = fileMappings[i].fileOffset;
+ info->mappings[i].sfm_max_prot = fileMappings[i].maxProt;
+ info->mappings[i].sfm_init_prot = fileMappings[i].initProt;
+ }
+ info->mappings[1].sfm_max_prot |= VM_PROT_SLIDE;
+ info->mappings[1].sfm_init_prot |= VM_PROT_SLIDE;
+ info->slideInfoAddressUnslid = fileMappings[2].address + cache->header.slideInfoOffset - fileMappings[2].fileOffset;
+ info->slideInfoSize = (long)cache->header.slideInfoSize;
+ if ( cache->header.mappingOffset > 0xD0 )
+ info->cachedDylibsGroupUnslid = cache->header.dylibsImageGroupAddr;
+ else
+ info->cachedDylibsGroupUnslid = 0;
+ if ( cache->header.mappingOffset >= 0xf8 ) {
+ info->sharedRegionStart = cache->header.sharedRegionStart;
+ info->sharedRegionSize = cache->header.sharedRegionSize;
+ info->maxSlide = cache->header.maxSlide;
+ }
+ else {
+ info->sharedRegionStart = SHARED_REGION_BASE;
+ info->sharedRegionSize = SHARED_REGION_SIZE;
+ info->maxSlide = SHARED_REGION_SIZE - (fileMappings[2].address + fileMappings[2].size - fileMappings[0].address);
+ }
+ return true;
+}
+
+#if !TARGET_IPHONE_SIMULATOR
+static bool reuseExistingCache(const SharedCacheOptions& options, SharedCacheLoadInfo* results)
+{
+ uint64_t cacheBaseAddress;
+#if __i386__
+ if ( syscall(294, &cacheBaseAddress) == 0 ) {
+#else
+ if ( __shared_region_check_np(&cacheBaseAddress) == 0 ) {
+#endif
+ const DyldSharedCache* existingCache = (DyldSharedCache*)cacheBaseAddress;
+ if ( validMagic(options, existingCache) ) {
+ const dyld_cache_mapping_info* const fileMappings = (dyld_cache_mapping_info*)(cacheBaseAddress + existingCache->header.mappingOffset);
+ results->loadAddress = existingCache;
+ results->slide = (long)(cacheBaseAddress - fileMappings[0].address);
+ if ( (existingCache->header.mappingOffset > 0xD0) && (existingCache->header.dylibsImageGroupAddr != 0) )
+ results->cachedDylibsGroup = (const launch_cache::binary_format::ImageGroup*)(existingCache->header.dylibsImageGroupAddr + results->slide);
+ else
+ results->cachedDylibsGroup = nullptr;
+ // we don't know the path this cache was previously loaded from, assume default
+ getCachePath(options, sizeof(results->path), results->path);
+ if ( options.verbose ) {
+ const shared_file_mapping_np* const mappings = (shared_file_mapping_np*)(cacheBaseAddress + existingCache->header.mappingOffset);
+ dyld::log("re-using existing shared cache (%s):\n", results->path);
+ shared_file_mapping_np slidMappings[3];
+ for (int i=0; i < 3; ++i) {
+ slidMappings[i] = mappings[i];
+ slidMappings[i].sfm_address += results->slide;
+ }
+ verboseSharedCacheMappings(slidMappings);
+ }
+ }
+ else {
+ results->errorMessage = "existing shared cache in memory is not compatible";
+ }
+ return true;
+ }
+ return false;
+}
+
+static long pickCacheASLR(CacheInfo& info)
+{
+ // choose new random slide
+#if __IPHONE_OS_VERSION_MIN_REQUIRED
+ // <rdar://problem/20848977> change shared cache slide for 32-bit arm to always be 16k aligned
+ long slide = ((arc4random() % info.maxSlide) & (-16384));
+#else
+ long slide = ((arc4random() % info.maxSlide) & (-4096));
+#endif
+
+ // <rdar://problem/32031197> respect -disable_aslr boot-arg
+ if ( dyld3::loader::bootArgsContains("-disable_aslr") )
+ slide = 0;
+
+ // update mappings
+ for (uint32_t i=0; i < 3; ++i) {
+ info.mappings[i].sfm_address += slide;
+ }
+
+ return slide;
+}
+
+static bool mapCacheSystemWide(const SharedCacheOptions& options, SharedCacheLoadInfo* results)
+{
+ CacheInfo info;
+ if ( !preflightCacheFile(options, results, &info) )
+ return false;
+
+ const dyld_cache_slide_info2* slideInfo = nullptr;
+ if ( info.slideInfoSize != 0 ) {
+ results->slide = pickCacheASLR(info);
+ slideInfo = (dyld_cache_slide_info2*)(info.slideInfoAddressUnslid + results->slide);
+ }
+ if ( info.cachedDylibsGroupUnslid != 0 )
+ results->cachedDylibsGroup = (const launch_cache::binary_format::ImageGroup*)(info.cachedDylibsGroupUnslid + results->slide);
+ else
+ results->cachedDylibsGroup = nullptr;
+
+ int result = __shared_region_map_and_slide_np(info.fd, 3, info.mappings, results->slide, slideInfo, info.slideInfoSize);
+ ::close(info.fd);
+ if ( result == 0 ) {
+ results->loadAddress = (const DyldSharedCache*)(info.mappings[0].sfm_address);
+ }
+ else {
+ // could be another process beat us to it
+ if ( reuseExistingCache(options, results) )
+ return true;
+ // if cache does not exist, then really is an error
+ results->errorMessage = "syscall to map cache into shared region failed";
+ return false;
+ }
+
+ if ( options.verbose ) {
+ dyld::log("mapped dyld cache file system wide: %s\n", results->path);
+ verboseSharedCacheMappings(info.mappings);
+ }
+ return true;
+}
+#endif
+
+static bool mapCachePrivate(const SharedCacheOptions& options, SharedCacheLoadInfo* results)
+{
+ // open and validate cache file
+ CacheInfo info;
+ if ( !preflightCacheFile(options, results, &info) )
+ return false;
+
+ // compute ALSR slide
+ results->slide = 0;
+ const dyld_cache_slide_info2* slideInfo = nullptr;
+#if !TARGET_IPHONE_SIMULATOR // simulator caches do not support sliding
+ if ( info.slideInfoSize != 0 ) {
+ results->slide = pickCacheASLR(info);
+ slideInfo = (dyld_cache_slide_info2*)(info.slideInfoAddressUnslid + results->slide);
+ }
+#endif
+ results->loadAddress = (const DyldSharedCache*)(info.mappings[0].sfm_address);
+ if ( info.cachedDylibsGroupUnslid != 0 )
+ results->cachedDylibsGroup = (const launch_cache::binary_format::ImageGroup*)(info.cachedDylibsGroupUnslid + results->slide);
+ else
+ results->cachedDylibsGroup = nullptr;
+
+ // remove the shared region sub-map
+ vm_deallocate(mach_task_self(), (vm_address_t)info.sharedRegionStart, (vm_size_t)info.sharedRegionSize);
+
+ // map cache just for this process with mmap()
+ for (int i=0; i < 3; ++i) {
+ void* mmapAddress = (void*)(uintptr_t)(info.mappings[i].sfm_address);
+ size_t size = (size_t)(info.mappings[i].sfm_size);
+ //dyld::log("dyld: mapping address %p with size 0x%08lX\n", mmapAddress, size);
+ int protection = 0;
+ if ( info.mappings[i].sfm_init_prot & VM_PROT_EXECUTE )
+ protection |= PROT_EXEC;
+ if ( info.mappings[i].sfm_init_prot & VM_PROT_READ )
+ protection |= PROT_READ;
+ if ( info.mappings[i].sfm_init_prot & VM_PROT_WRITE )
+ protection |= PROT_WRITE;
+ off_t offset = info.mappings[i].sfm_file_offset;
+ if ( ::mmap(mmapAddress, size, protection, MAP_FIXED | MAP_PRIVATE, info.fd, offset) != mmapAddress ) {
+ // failed to map some chunk of this shared cache file
+ // clear shared region
+ vm_deallocate(mach_task_self(), (vm_address_t)info.sharedRegionStart, (vm_size_t)info.sharedRegionSize);
+ // return failure
+ results->loadAddress = nullptr;
+ results->cachedDylibsGroup = nullptr;
+ results->errorMessage = "could not mmap() part of dyld cache";
+ return false;
+ }
+ }
+
+ // update all __DATA pages with slide info
+ const dyld_cache_slide_info* slideInfoHeader = (dyld_cache_slide_info*)slideInfo;
+ if ( slideInfoHeader != nullptr ) {
+ if ( slideInfoHeader->version != 2 ) {
+ results->errorMessage = "invalide slide info in cache file";
+ return false;
+ }
+ const dyld_cache_slide_info2* slideHeader = (dyld_cache_slide_info2*)slideInfo;
+ const uint32_t page_size = slideHeader->page_size;
+ const uint16_t* page_starts = (uint16_t*)((long)(slideInfo) + slideHeader->page_starts_offset);
+ const uint16_t* page_extras = (uint16_t*)((long)(slideInfo) + slideHeader->page_extras_offset);
+ const uintptr_t dataPagesStart = (uintptr_t)info.mappings[1].sfm_address;
+ for (int i=0; i < slideHeader->page_starts_count; ++i) {
+ uint8_t* page = (uint8_t*)(long)(dataPagesStart + (page_size*i));
+ uint16_t pageEntry = page_starts[i];
+ //dyld::log("page[%d]: page_starts[i]=0x%04X\n", i, pageEntry);
+ if ( pageEntry == DYLD_CACHE_SLIDE_PAGE_ATTR_NO_REBASE )
+ continue;
+ if ( pageEntry & DYLD_CACHE_SLIDE_PAGE_ATTR_EXTRA ) {
+ uint16_t chainIndex = (pageEntry & 0x3FFF);
+ bool done = false;
+ while ( !done ) {
+ uint16_t pInfo = page_extras[chainIndex];
+ uint16_t pageStartOffset = (pInfo & 0x3FFF)*4;
+ //dyld::log(" chain[%d] pageOffset=0x%03X\n", chainIndex, pageStartOffset);
+ rebaseChain(page, pageStartOffset, results->slide, slideInfo);
+ done = (pInfo & DYLD_CACHE_SLIDE_PAGE_ATTR_END);
+ ++chainIndex;
+ }
+ }
+ else {
+ uint32_t pageOffset = pageEntry * 4;
+ //dyld::log(" start pageOffset=0x%03X\n", pageOffset);
+ rebaseChain(page, pageOffset, results->slide, slideInfo);
+ }
+ }
+ }
+
+ if ( options.verbose ) {
+ dyld::log("mapped dyld cache file private to process (%s):\n", results->path);
+ verboseSharedCacheMappings(info.mappings);
+ }
+ return true;
+}
+
+
+
+bool loadDyldCache(const SharedCacheOptions& options, SharedCacheLoadInfo* results)
+{
+ results->loadAddress = 0;
+ results->slide = 0;
+ results->cachedDylibsGroup = nullptr;
+ results->errorMessage = nullptr;
+
+#if TARGET_IPHONE_SIMULATOR
+ // simulator only supports mmap()ing cache privately into process
+ return mapCachePrivate(options, results);
+#else
+ if ( options.forcePrivate ) {
+ // mmap cache into this process only
+ return mapCachePrivate(options, results);
+ }
+ else {
+ // fast path: when cache is already mapped into shared region
+ if ( reuseExistingCache(options, results) )
+ return (results->errorMessage != nullptr);
+
+ // slow path: this is first process to load cache
+ return mapCacheSystemWide(options, results);
+ }
+#endif
+}
+
+
+bool findInSharedCacheImage(const SharedCacheLoadInfo& loadInfo, const char* dylibPathToFind, SharedCacheFindDylibResults* results)
+{
+ if ( loadInfo.loadAddress == nullptr )
+ return false;
+
+ // HACK: temp support for old caches
+ if ( (loadInfo.cachedDylibsGroup == nullptr) || (loadInfo.loadAddress->header.formatVersion != launch_cache::binary_format::kFormatVersion) ) {
+ const dyld_cache_image_info* const start = (dyld_cache_image_info*)((uint8_t*)loadInfo.loadAddress + loadInfo.loadAddress->header.imagesOffset);
+ const dyld_cache_image_info* const end = &start[loadInfo.loadAddress->header.imagesCount];
+ for (const dyld_cache_image_info* p = start; p != end; ++p) {
+ const char* aPath = (char*)loadInfo.loadAddress + p->pathFileOffset;
+ if ( strcmp(aPath, dylibPathToFind) == 0 ) {
+ results->mhInCache = (const mach_header*)(p->address+loadInfo.slide);
+ results->pathInCache = aPath;
+ results->slideInCache = loadInfo.slide;
+ results->imageData = nullptr;
+ return true;
+ }
+ }
+ return false;
+ }
+ // HACK: end
+
+ launch_cache::ImageGroup dylibsGroup(loadInfo.cachedDylibsGroup);
+ uint32_t foundIndex;
+ const launch_cache::binary_format::Image* imageData = dylibsGroup.findImageByPath(dylibPathToFind, foundIndex);
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+ // <rdar://problem/32740215> handle symlink to cached dylib
+ if ( imageData == nullptr ) {
+ char resolvedPath[PATH_MAX];
+ if ( realpath(dylibPathToFind, resolvedPath) != nullptr )
+ imageData = dylibsGroup.findImageByPath(resolvedPath, foundIndex);
+ }
+#endif
+ if ( imageData == nullptr )
+ return false;
+
+ launch_cache::Image image(imageData);
+ results->mhInCache = (const mach_header*)((uintptr_t)loadInfo.loadAddress + image.cacheOffset());
+ results->pathInCache = image.path();
+ results->slideInCache = loadInfo.slide;
+ results->imageData = imageData;
+ return true;
+}
+
+
+bool pathIsInSharedCacheImage(const SharedCacheLoadInfo& loadInfo, const char* dylibPathToFind)
+{
+ if ( (loadInfo.loadAddress == nullptr) || (loadInfo.cachedDylibsGroup == nullptr) || (loadInfo.loadAddress->header.formatVersion != launch_cache::binary_format::kFormatVersion) )
+ return false;
+
+ launch_cache::ImageGroup dylibsGroup(loadInfo.cachedDylibsGroup);
+ uint32_t foundIndex;
+ const launch_cache::binary_format::Image* imageData = dylibsGroup.findImageByPath(dylibPathToFind, foundIndex);
+ return (imageData != nullptr);
+}
+
+
+} // namespace dyld3
+