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+++ dyld/dyld-750.5/src/ImageLoaderMachOClassic.cpp
@@ -0,0 +1,2092 @@
+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2004-2010 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@
+ */
+
+// work around until conformance work is complete rdar://problem/4508801
+#define __srr0 srr0
+#define __eip eip
+#define __rip rip
+
+
+#include <string.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/fcntl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <mach/mach.h>
+#include <mach/thread_status.h>
+#include <mach-o/loader.h>
+#include <mach-o/reloc.h>
+#include <mach-o/nlist.h>
+#include <sys/sysctl.h>
+#include <libkern/OSAtomic.h>
+#include <libkern/OSCacheControl.h>
+#include <mach-o/dyld_images.h>
+
+#if __x86_64__
+ #include <mach-o/x86_64/reloc.h>
+#endif
+#if __arm__
+ #include <mach-o/arm/reloc.h>
+#endif
+
+#include "ImageLoaderMachOClassic.h"
+
+// in dyldStartup.s
+extern "C" void stub_binding_helper_i386_old();
+
+
+#if __x86_64__
+ #define POINTER_RELOC X86_64_RELOC_UNSIGNED
+#else
+ #define POINTER_RELOC GENERIC_RELOC_VANILLA
+#endif
+
+
+// relocation_info.r_length field has value 3 for 64-bit executables and value 2 for 32-bit executables
+#if __LP64__
+ #define RELOC_SIZE 3
+ #define LC_SEGMENT_COMMAND LC_SEGMENT_64
+ #define LC_ROUTINES_COMMAND LC_ROUTINES_64
+ struct macho_segment_command : public segment_command_64 {};
+ struct macho_section : public section_64 {};
+ struct macho_routines_command : public routines_command_64 {};
+#else
+ #define RELOC_SIZE 2
+ #define LC_SEGMENT_COMMAND LC_SEGMENT
+ #define LC_ROUTINES_COMMAND LC_ROUTINES
+ struct macho_segment_command : public segment_command {};
+ struct macho_section : public section {};
+ struct macho_routines_command : public routines_command {};
+#endif
+
+
+
+
+// create image for main executable
+ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateMainExecutable(const macho_header* mh, uintptr_t slide, const char* path,
+ unsigned int segCount, unsigned int libCount, const LinkContext& context)
+{
+ ImageLoaderMachOClassic* image = ImageLoaderMachOClassic::instantiateStart(mh, path, segCount, libCount);
+
+ // set slide for PIE programs
+ image->setSlide(slide);
+
+ // for PIE record end of program, to know where to start loading dylibs
+ if ( slide != 0 )
+ fgNextPIEDylibAddress = (uintptr_t)image->getEnd();
+
+ image->disableCoverageCheck();
+ image->instantiateFinish(context);
+ image->setMapped(context);
+
+#if __i386__
+ // kernel may have mapped in __IMPORT segment read-only, we need it read/write to do binding
+ if ( image->fReadOnlyImportSegment ) {
+ for(unsigned int i=0; i < image->fSegmentsCount; ++i) {
+ if ( image->segIsReadOnlyImport(i) )
+ image->segMakeWritable(i, context);
+ }
+ }
+#endif
+
+ if ( context.verboseMapping ) {
+ dyld::log("dyld: Main executable mapped %s\n", path);
+ for(unsigned int i=0, e=image->segmentCount(); i < e; ++i) {
+ const char* name = image->segName(i);
+ if ( (strcmp(name, "__PAGEZERO") == 0) || (strcmp(name, "__UNIXSTACK") == 0) )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n", name, image->segPreferredLoadAddress(i), image->segPreferredLoadAddress(i)+image->segSize(i));
+ else
+ dyld::log("%18s at 0x%08lX->0x%08lX\n", name, image->segActualLoadAddress(i), image->segActualEndAddress(i));
+ }
+ }
+
+ return image;
+}
+
+// create image by mapping in a mach-o file
+ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromFile(const char* path, int fd, const uint8_t* fileData, size_t lenFileData,
+ uint64_t offsetInFat, uint64_t lenInFat, const struct stat& info,
+ unsigned int segCount, unsigned int libCount,
+ const struct linkedit_data_command* codeSigCmd, const LinkContext& context)
+{
+ ImageLoaderMachOClassic* image = ImageLoaderMachOClassic::instantiateStart((macho_header*)fileData, path, segCount, libCount);
+ try {
+ // record info about file
+ image->setFileInfo(info.st_dev, info.st_ino, info.st_mtime);
+
+ // if this image is code signed, let kernel validate signature before mapping any pages from image
+ image->loadCodeSignature(codeSigCmd, fd, offsetInFat, context);
+
+ // Validate that first data we read with pread actually matches with code signature
+ image->validateFirstPages(codeSigCmd, fd, fileData, lenFileData, offsetInFat, context);
+
+ // mmap segments
+ image->mapSegmentsClassic(fd, offsetInFat, lenInFat, info.st_size, context);
+
+ // finish up
+ image->instantiateFinish(context);
+
+ // if path happens to be same as in LC_DYLIB_ID load command use that, otherwise malloc a copy of the path
+ const char* installName = image->getInstallPath();
+ if ( (installName != NULL) && (strcmp(installName, path) == 0) && (path[0] == '/') )
+ image->setPathUnowned(installName);
+ else if ( (path[0] != '/') || (strstr(path, "../") != NULL) ) {
+ // rdar://problem/10733082 Fix up @path based paths during introspection
+ // rdar://problem/5135363 turn relative paths into absolute paths so gdb, Symbolication can later find them
+ char realPath[MAXPATHLEN];
+ if ( fcntl(fd, F_GETPATH, realPath) == 0 )
+ image->setPaths(path, realPath);
+ else
+ image->setPath(path);
+ }
+ else
+ image->setPath(path);
+
+ // make sure path is stable before recording in dyld_all_image_infos
+ image->setMapped(context);
+
+ }
+ catch (...) {
+ // ImageLoader::setMapped() can throw an exception to block loading of image
+ // <rdar://problem/6169686> Leaked fSegmentsArray and image segments during failed dlopen_preflight
+ delete image;
+ throw;
+ }
+
+ return image;
+}
+
+// create image by using cached mach-o file
+ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromCache(const macho_header* mh, const char* path, long slide, const struct stat& info,
+ unsigned int segCount, unsigned int libCount, const LinkContext& context)
+{
+ ImageLoaderMachOClassic* image = ImageLoaderMachOClassic::instantiateStart(mh, path, segCount, libCount);
+ try {
+ // record info about file
+ image->setFileInfo(info.st_dev, info.st_ino, info.st_mtime);
+
+ // remember this is from shared cache and cannot be unloaded
+ image->fInSharedCache = true;
+ image->setNeverUnload();
+ image->disableCoverageCheck();
+
+ // segments already mapped in cache
+ if ( context.verboseMapping ) {
+ dyld::log("dyld: Using shared cached for %s\n", path);
+ for(unsigned int i=0, e=image->segmentCount(); i < e; ++i) {
+ dyld::log("%18s at 0x%08lX->0x%08lX\n", image->segName(i), image->segActualLoadAddress(i), image->segActualEndAddress(i));
+ }
+ }
+
+ image->instantiateFinish(context);
+ image->setMapped(context);
+ }
+ catch (...) {
+ // ImageLoader::setMapped() can throw an exception to block loading of image
+ // <rdar://problem/6169686> Leaked fSegmentsArray and image segments during failed dlopen_preflight
+ delete image;
+ throw;
+ }
+
+ return image;
+}
+
+// create image by copying an in-memory mach-o file
+ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromMemory(const char* moduleName, const macho_header* mh, uint64_t len,
+ unsigned int segCount, unsigned int libCount, const LinkContext& context)
+{
+ ImageLoaderMachOClassic* image = ImageLoaderMachOClassic::instantiateStart(mh, moduleName, segCount, libCount);
+ try {
+ // map segments
+ if ( mh->filetype == MH_EXECUTE )
+ throw "can't load another MH_EXECUTE";
+
+ // vmcopy segments
+ image->ImageLoaderMachO::mapSegments((const void*)mh, len, context);
+
+ // for compatibility, never unload dylibs loaded from memory
+ image->setNeverUnload();
+
+ image->disableCoverageCheck();
+
+ // bundle loads need path copied
+ if ( moduleName != NULL )
+ image->setPath(moduleName);
+
+ image->instantiateFinish(context);
+ image->setMapped(context);
+ }
+ catch (...) {
+ // ImageLoader::setMapped() can throw an exception to block loading of image
+ // <rdar://problem/6169686> Leaked fSegmentsArray and image segments during failed dlopen_preflight
+ delete image;
+ throw;
+ }
+
+ return image;
+}
+
+
+ImageLoaderMachOClassic::ImageLoaderMachOClassic(const macho_header* mh, const char* path,
+ unsigned int segCount, uint32_t segOffsets[], unsigned int libCount)
+ : ImageLoaderMachO(mh, path, segCount, segOffsets, libCount), fStrings(NULL), fSymbolTable(NULL), fDynamicInfo(NULL)
+{
+}
+
+// construct ImageLoaderMachOClassic using "placement new" with SegmentMachO objects array at end
+ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateStart(const macho_header* mh, const char* path,
+ unsigned int segCount, unsigned int libCount)
+{
+ size_t size = sizeof(ImageLoaderMachOClassic) + segCount * sizeof(uint32_t) + libCount * sizeof(ImageLoader*);
+ ImageLoaderMachOClassic* allocatedSpace = static_cast<ImageLoaderMachOClassic*>(malloc(size));
+ if ( allocatedSpace == NULL )
+ throw "malloc failed";
+ uint32_t* segOffsets = ((uint32_t*)(((uint8_t*)allocatedSpace) + sizeof(ImageLoaderMachOClassic)));
+ bzero(&segOffsets[segCount], libCount*sizeof(void*)); // zero out lib array
+ return new (allocatedSpace) ImageLoaderMachOClassic(mh, path, segCount, segOffsets, libCount);
+}
+
+
+
+// common code to finish initializing object
+void ImageLoaderMachOClassic::instantiateFinish(const LinkContext& context)
+{
+ // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
+ this->parseLoadCmds(context);
+}
+
+ImageLoaderMachOClassic::~ImageLoaderMachOClassic()
+{
+ // don't do clean up in ~ImageLoaderMachO() because virtual call to segmentCommandOffsets() won't work
+ destroy();
+}
+
+uint32_t* ImageLoaderMachOClassic::segmentCommandOffsets() const
+{
+ return ((uint32_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOClassic)));
+}
+
+
+ImageLoader* ImageLoaderMachOClassic::libImage(unsigned int libIndex) const
+{
+ const uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOClassic) + fSegmentsCount*sizeof(uint32_t)));
+ // mask off low bits
+ return (ImageLoader*)(images[libIndex] & (-4));
+}
+
+bool ImageLoaderMachOClassic::libReExported(unsigned int libIndex) const
+{
+ const uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOClassic) + fSegmentsCount*sizeof(uint32_t)));
+ // re-export flag is low bit
+ return ((images[libIndex] & 1) != 0);
+}
+
+bool ImageLoaderMachOClassic::libIsUpward(unsigned int libIndex) const
+{
+ const uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOClassic) + fSegmentsCount*sizeof(uint32_t)));
+ // upward flag is second bit
+ return ((images[libIndex] & 2) != 0);
+}
+
+
+void ImageLoaderMachOClassic::setLibImage(unsigned int libIndex, ImageLoader* image, bool reExported, bool upward)
+{
+ uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOClassic) + fSegmentsCount*sizeof(uint32_t)));
+ uintptr_t value = (uintptr_t)image;
+ if ( reExported )
+ value |= 1;
+ if ( upward )
+ value |= 2;
+ images[libIndex] = value;
+}
+
+
+void ImageLoaderMachOClassic::setSymbolTableInfo(const macho_nlist* symbols, const char* strings, const dysymtab_command* dynSym)
+{
+ fSymbolTable = symbols;
+ fStrings = strings;
+ fDynamicInfo = dynSym;
+}
+
+
+
+#if SPLIT_SEG_DYLIB_SUPPORT
+unsigned int
+ImageLoaderMachOClassic::getExtraZeroFillEntriesCount()
+{
+ // calculate mapping entries
+ unsigned int extraZeroFillEntries = 0;
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ if ( segHasTrailingZeroFill(i) )
+ ++extraZeroFillEntries;
+ }
+
+ return extraZeroFillEntries;
+}
+
+void
+ImageLoaderMachOClassic::initMappingTable(uint64_t offsetInFat,
+ shared_file_mapping_np *mappingTable)
+{
+ for(unsigned int i=0,entryIndex=0; i < fSegmentsCount; ++i, ++entryIndex) {
+ shared_file_mapping_np* entry = &mappingTable[entryIndex];
+ entry->sfm_address = segActualLoadAddress(i);
+ entry->sfm_size = segFileSize(i);
+ entry->sfm_file_offset = segFileOffset(i) + offsetInFat;
+ entry->sfm_init_prot = VM_PROT_NONE;
+ if ( !segUnaccessible(i) ) {
+ if ( segExecutable(i) )
+ entry->sfm_init_prot |= VM_PROT_EXECUTE;
+ if ( segReadable(i) )
+ entry->sfm_init_prot |= VM_PROT_READ;
+ if ( segWriteable(i) )
+ entry->sfm_init_prot |= VM_PROT_WRITE | VM_PROT_COW;
+ }
+ entry->sfm_max_prot = entry->sfm_init_prot;
+ if ( segHasTrailingZeroFill(i) ) {
+ shared_file_mapping_np* zfentry = &mappingTable[++entryIndex];
+ zfentry->sfm_address = entry->sfm_address + segFileSize(i);
+ zfentry->sfm_size = segSize(i) - segFileSize(i);
+ zfentry->sfm_file_offset = 0;
+ zfentry->sfm_init_prot = entry->sfm_init_prot | VM_PROT_COW | VM_PROT_ZF;
+ zfentry->sfm_max_prot = zfentry->sfm_init_prot;
+ }
+ }
+}
+
+int
+ImageLoaderMachOClassic::mapSplitSegDylibOutsideSharedRegion(int fd,
+ uint64_t offsetInFat,
+ uint64_t lenInFat,
+ uint64_t fileLen,
+ const LinkContext& context)
+{
+ uintptr_t nextAltLoadAddress = 0;
+ const unsigned int segmentCount = fSegmentsCount;
+ const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
+ const unsigned int regionCount = segmentCount+extraZeroFillEntries;
+ shared_file_mapping_np regions[regionCount];
+ initMappingTable(offsetInFat, regions);
+ int r = -1;
+ // find space somewhere to allocate split seg
+ bool foundRoom = false;
+ while ( ! foundRoom ) {
+ foundRoom = true;
+ for(unsigned int i=0; i < regionCount; ++i) {
+ vm_address_t addr = (vm_address_t)(nextAltLoadAddress + regions[i].sfm_address - regions[0].sfm_address);
+ vm_size_t size = (vm_size_t)regions[i].sfm_size ;
+ r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
+ if ( 0 != r ) {
+ // no room here, deallocate what has succeeded so far
+ for(unsigned int j=0; j < i; ++j) {
+ addr = (vm_address_t)(nextAltLoadAddress + regions[j].sfm_address - regions[0].sfm_address);
+ size = (vm_size_t)(regions[j].sfm_size);
+ (void)vm_deallocate(mach_task_self(), addr, size);
+ }
+ nextAltLoadAddress += 0x00100000; // skip ahead 1MB and try again
+ // skip over shared region
+ if ( (SHARED_REGION_BASE <= nextAltLoadAddress) && (nextAltLoadAddress < (SHARED_REGION_BASE + SHARED_REGION_SIZE)) )
+ nextAltLoadAddress = (SHARED_REGION_BASE + SHARED_REGION_SIZE);
+ if ( nextAltLoadAddress > 0xFF000000 )
+ throw "can't map split seg anywhere";
+ foundRoom = false;
+ break;
+ }
+ }
+ }
+
+ // map in each region
+ uintptr_t slide = (uintptr_t)(nextAltLoadAddress - regions[0].sfm_address);
+ this->setSlide(slide);
+ for(unsigned int i=0; i < regionCount; ++i) {
+ if ( ((regions[i].sfm_init_prot & VM_PROT_ZF) != 0) || (regions[i].sfm_size == 0) ) {
+ // nothing to mmap for zero-fills areas, they are just vm_allocated
+ }
+ else {
+ void* mmapAddress = (void*)(uintptr_t)(regions[i].sfm_address + slide);
+ size_t size = (size_t)regions[i].sfm_size;
+ int protection = 0;
+ if ( regions[i].sfm_init_prot & VM_PROT_EXECUTE )
+ protection |= PROT_EXEC;
+ if ( regions[i].sfm_init_prot & VM_PROT_READ )
+ protection |= PROT_READ;
+ if ( regions[i].sfm_init_prot & VM_PROT_WRITE )
+ protection |= PROT_WRITE;
+ off_t offset = regions[i].sfm_file_offset;
+ //dyld::log("mmap(%p, 0x%08lX, %s\n", mmapAddress, size, fPath);
+ mmapAddress = mmap(mmapAddress, size, protection, MAP_FIXED | MAP_PRIVATE, fd, offset);
+ if ( mmapAddress == ((void*)(-1)) )
+ throw "mmap error";
+ }
+ }
+
+ // logging
+ if ( context.verboseMapping ) {
+ dyld::log("dyld: Mapping split-seg outside shared region, slid by 0x%08lX %s\n", this->fSlide, this->getPath());
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ const shared_file_mapping_np* entry = ®ions[entryIndex];
+ if ( (entry->sfm_init_prot & VM_PROT_ZF) == 0 )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n",
+ segName(segIndex), segActualLoadAddress(segIndex), segActualEndAddress(segIndex)-1);
+ if ( entryIndex < (regionCount-1) ) {
+ const shared_file_mapping_np* nextEntry = ®ions[entryIndex+1];
+ if ( (nextEntry->sfm_init_prot & VM_PROT_ZF) != 0 ) {
+ uint64_t segOffset = nextEntry->sfm_address - entry->sfm_address;
+ dyld::log("%18s at 0x%08lX->0x%08lX (zerofill)\n",
+ segName(segIndex), (uintptr_t)(segActualLoadAddress(segIndex) + segOffset), (uintptr_t)(segActualLoadAddress(segIndex) + segOffset + nextEntry->sfm_size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+
+ return r;
+}
+#endif // SPLIT_SEG_DYLIB_SUPPORT
+
+
+void ImageLoaderMachOClassic::mapSegmentsClassic(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
+{
+ // non-split segment libraries handled by super class
+ if ( !fIsSplitSeg )
+ return ImageLoaderMachO::mapSegments(fd, offsetInFat, lenInFat, fileLen, context);
+
+#if SPLIT_SEG_SHARED_REGION_SUPPORT
+ // don't map split-seg dylibs into shared region if shared cache is in use
+ if ( ! context.dyldLoadedAtSameAddressNeededBySharedCache ) {
+ // try to map into shared region at preferred address
+ if ( mapSplitSegDylibInfoSharedRegion(fd, offsetInFat, lenInFat, fileLen, context) == 0)
+ return;
+ }
+ // if there is a problem, fall into case where we map file somewhere outside the shared region
+#endif
+
+#if SPLIT_SEG_DYLIB_SUPPORT
+ // support old split-seg dylibs by mapping them where ever we find space
+ if ( mapSplitSegDylibOutsideSharedRegion(fd, offsetInFat, lenInFat, fileLen, context) != 0 )
+#endif
+ throw "mapping error";
+}
+
+
+#if SPLIT_SEG_SHARED_REGION_SUPPORT
+static int _shared_region_map_np(int fd, uint32_t count, const shared_file_mapping_np mappings[])
+{
+ return syscall(295, fd, count, mappings);
+}
+
+int
+ImageLoaderMachOClassic::mapSplitSegDylibInfoSharedRegion(int fd,
+ uint64_t offsetInFat,
+ uint64_t lenInFat,
+ uint64_t fileLen,
+ const LinkContext& context)
+{
+ // build table of segments to map
+ const unsigned int segmentCount = fSegmentsCount;
+ const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
+ const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
+ shared_file_mapping_np mappingTable[mappingTableCount];
+ initMappingTable(offsetInFat, mappingTable);
+
+ // try to map it in shared
+ int r = _shared_region_map_np(fd, mappingTableCount, mappingTable);
+ if ( 0 == r ) {
+ this->setNeverUnload();
+ if ( context.verboseMapping ) {
+ dyld::log("dyld: Mapping split-seg shared %s\n", this->getPath());
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ const shared_file_mapping_np* entry = &mappingTable[entryIndex];
+ if ( (entry->sfm_init_prot & VM_PROT_ZF) == 0 )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n",
+ segName(segIndex), segActualLoadAddress(segIndex), segActualEndAddress(segIndex)-1);
+ if ( entryIndex < (mappingTableCount-1) ) {
+ const shared_file_mapping_np* nextEntry = &mappingTable[entryIndex+1];
+ if ( (nextEntry->sfm_init_prot & VM_PROT_ZF) != 0 ) {
+ uint64_t segOffset = nextEntry->sfm_address - entry->sfm_address;
+ dyld::log("%18s at 0x%08lX->0x%08lX\n",
+ segName(segIndex), (uintptr_t)(segActualLoadAddress(segIndex) + segOffset),
+ (uintptr_t)(segActualLoadAddress(segIndex) + segOffset + nextEntry->sfm_size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+ }
+ return r;
+}
+
+#endif // SPLIT_SEG_SHARED_REGION_SUPPORT
+
+// test if this image is re-exported through parent (the image that loaded this one)
+bool ImageLoaderMachOClassic::isSubframeworkOf(const LinkContext& context, const ImageLoader* parent) const
+{
+ if ( fInUmbrella ) {
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if (cmd->cmd == LC_SUB_FRAMEWORK) {
+ const struct sub_framework_command* subf = (struct sub_framework_command*)cmd;
+ const char* exportThruName = (char*)cmd + subf->umbrella.offset;
+ // need to match LC_SUB_FRAMEWORK string against the leaf name of the install location of parent...
+ const char* parentInstallPath = parent->getInstallPath();
+ if ( parentInstallPath != NULL ) {
+ const char* lastSlash = strrchr(parentInstallPath, '/');
+ if ( lastSlash != NULL ) {
+ if ( strcmp(&lastSlash[1], exportThruName) == 0 )
+ return true;
+ if ( context.imageSuffix != NULL ) {
+ // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
+ for(const char* const* suffix = context.imageSuffix; *suffix != NULL; ++suffix) {
+ char reexportAndSuffix[strlen(*suffix)+strlen(exportThruName)+1];
+ strcpy(reexportAndSuffix, exportThruName);
+ strcat(reexportAndSuffix, *suffix);
+ if ( strcmp(&lastSlash[1], reexportAndSuffix) == 0 )
+ return true;
+ }
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+ return false;
+}
+
+// test if child is re-exported
+bool ImageLoaderMachOClassic::hasSubLibrary(const LinkContext& context, const ImageLoader* child) const
+{
+ if ( fHasSubLibraries ) {
+ // need to match LC_SUB_LIBRARY string against the leaf name (without extension) of the install location of child...
+ const char* childInstallPath = child->getInstallPath();
+ if ( childInstallPath != NULL ) {
+ const char* lastSlash = strrchr(childInstallPath, '/');
+ if ( lastSlash != NULL ) {
+ const char* firstDot = strchr(lastSlash, '.');
+ size_t len;
+ if ( firstDot == NULL )
+ len = strlen(lastSlash);
+ else
+ len = firstDot-lastSlash-1;
+ char childLeafName[len+1];
+ strncpy(childLeafName, &lastSlash[1], len);
+ childLeafName[len] = '\0';
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SUB_LIBRARY:
+ {
+ const struct sub_library_command* lib = (struct sub_library_command*)cmd;
+ const char* aSubLibName = (char*)cmd + lib->sub_library.offset;
+ if ( strcmp(aSubLibName, childLeafName) == 0 )
+ return true;
+ if ( context.imageSuffix != NULL ) {
+ // when DYLD_IMAGE_SUFFIX is used, childLeafName string needs imageSuffix removed from end
+ for(const char* const* suffix = context.imageSuffix; *suffix != NULL; ++suffix) {
+ char aSubLibNameAndSuffix[strlen(*suffix)+strlen(aSubLibName)+1];
+ strcpy(aSubLibNameAndSuffix, aSubLibName);
+ strcat(aSubLibNameAndSuffix, *suffix);
+ if ( strcmp(aSubLibNameAndSuffix, childLeafName) == 0 )
+ return true;
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+ }
+ }
+ if ( fHasSubUmbrella ) {
+ // need to match LC_SUB_UMBRELLA string against the leaf name of install location of child...
+ const char* childInstallPath = child->getInstallPath();
+ if ( childInstallPath != NULL ) {
+ const char* lastSlash = strrchr(childInstallPath, '/');
+ if ( lastSlash != NULL ) {
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SUB_UMBRELLA:
+ {
+ const struct sub_umbrella_command* um = (struct sub_umbrella_command*)cmd;
+ const char* aSubUmbrellaName = (char*)cmd + um->sub_umbrella.offset;
+ if ( strcmp(aSubUmbrellaName, &lastSlash[1]) == 0 )
+ return true;
+ if ( context.imageSuffix != NULL ) {
+ // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
+ for(const char* const* suffix = context.imageSuffix; *suffix != NULL; ++suffix) {
+ char umbrellaAndSuffix[strlen(*suffix)+strlen(aSubUmbrellaName)+1];
+ strcpy(umbrellaAndSuffix, aSubUmbrellaName);
+ strcat(umbrellaAndSuffix, *suffix);
+ if ( strcmp(umbrellaAndSuffix, &lastSlash[1]) == 0 )
+ return true;
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+ }
+ }
+ return false;
+}
+
+
+uintptr_t ImageLoaderMachOClassic::getFirstWritableSegmentAddress()
+{
+ // in split segment libraries r_address is offset from first writable segment
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ if ( segWriteable(i) )
+ return segActualLoadAddress(i);
+ }
+ throw "no writable segment";
+}
+
+uintptr_t ImageLoaderMachOClassic::getRelocBase()
+{
+ // r_address is either an offset from the first segment address
+ // or from the first writable segment address
+#if __x86_64__
+ return getFirstWritableSegmentAddress();
+#else
+ if ( fIsSplitSeg )
+ return getFirstWritableSegmentAddress();
+ else
+ return segActualLoadAddress(0);
+#endif
+}
+
+
+#if PREBOUND_IMAGE_SUPPORT
+void ImageLoaderMachOClassic::resetPreboundLazyPointers(const LinkContext& context)
+{
+ // loop through all local (internal) relocation records looking for pre-bound-lazy-pointer values
+ const uintptr_t relocBase = this->getRelocBase();
+ const uintptr_t slide = this->fSlide;
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->locreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nlocrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ if ( (reloc->r_address & R_SCATTERED) != 0 ) {
+ const struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
+ if (sreloc->r_length == RELOC_SIZE) {
+ uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
+ switch(sreloc->r_type) {
+ #if __i386__
+ case GENERIC_RELOC_PB_LA_PTR:
+ *locationToFix = sreloc->r_value + slide;
+ break;
+ #endif
+ #if __arm__
+ case ARM_RELOC_PB_LA_PTR:
+ *locationToFix = sreloc->r_value + slide;
+ break;
+ #endif
+ }
+ }
+ }
+ }
+}
+#endif
+
+
+
+
+void ImageLoaderMachOClassic::rebase(const LinkContext& context, uintptr_t slide)
+{
+ CRSetCrashLogMessage2(this->getPath());
+ const uintptr_t relocBase = this->getRelocBase();
+
+ // loop through all local (internal) relocation records
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->locreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nlocrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ uintptr_t rebaseAddr;
+ try {
+ #if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(reloc);
+ #endif
+ #if __x86_64__
+ // only one kind of local relocation supported for x86_64
+ if ( reloc->r_length != 3 )
+ throw "bad local relocation length";
+ if ( reloc->r_type != X86_64_RELOC_UNSIGNED )
+ throw "unknown local relocation type";
+ if ( reloc->r_pcrel != 0 )
+ throw "bad local relocation pc_rel";
+ if ( reloc->r_extern != 0 )
+ throw "extern relocation found with local relocations";
+ rebaseAddr = reloc->r_address + relocBase;
+ if ( ! this->containsAddress((void*)rebaseAddr) )
+ dyld::throwf("local reloc %p not in mapped image\n", (void*)rebaseAddr);
+ *((uintptr_t*)rebaseAddr) += slide;
+ if ( context.verboseRebase )
+ dyld::log("dyld: rebase: %s:*0x%08lX += 0x%08lX\n", this->getShortName(), rebaseAddr, slide);
+ #else
+ if ( (reloc->r_address & R_SCATTERED) == 0 ) {
+ if ( reloc->r_symbolnum == R_ABS ) {
+ // ignore absolute relocations
+ }
+ else if (reloc->r_length == RELOC_SIZE) {
+ switch(reloc->r_type) {
+ case GENERIC_RELOC_VANILLA:
+ rebaseAddr = reloc->r_address + relocBase;
+ if ( ! this->containsAddress((void*)rebaseAddr) )
+ dyld::throwf("local reloc %p not in mapped image\n", (void*)rebaseAddr);
+ *((uintptr_t*)rebaseAddr) += slide;
+ if ( context.verboseRebase )
+ dyld::log("dyld: rebase: %s:*0x%08lX += 0x%08lX\n", this->getShortName(), rebaseAddr, slide);
+ break;
+ default:
+ throw "unknown local relocation type";
+ }
+ }
+ else {
+ throw "bad local relocation length";
+ }
+ }
+ else {
+ const struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
+ if (sreloc->r_length == RELOC_SIZE) {
+ uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
+ switch(sreloc->r_type) {
+ case GENERIC_RELOC_VANILLA:
+ if ( ! this->containsAddress((void*)locationToFix) )
+ dyld::throwf("local scattered reloc %p not in mapped image\n", locationToFix);
+ *locationToFix += slide;
+ if ( context.verboseRebase )
+ dyld::log("dyld: rebase: %s:*0x%08lX += 0x%08lX\n", this->getShortName(), (uintptr_t)locationToFix, slide);
+ break;
+ #if __i386__
+ case GENERIC_RELOC_PB_LA_PTR:
+ // do nothing
+ break;
+ #elif __arm__
+ case ARM_RELOC_PB_LA_PTR:
+ // do nothing
+ break;
+ #endif
+ default:
+ throw "unknown local scattered relocation type";
+ }
+ }
+ else {
+ throw "bad local scattered relocation length";
+ }
+ }
+ #endif // x86_64
+ }
+ catch (const char* msg) {
+ const uint8_t* r = (uint8_t*)reloc;
+ dyld::throwf("%s in %s. reloc record at %p: 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X",
+ msg, this->getPath(), reloc, r[0], r[1], r[2], r[3], r[4], r[5], r[6], r[7]);
+ }
+ }
+
+ // update stats
+ fgTotalRebaseFixups += fDynamicInfo->nlocrel;
+ CRSetCrashLogMessage2(NULL);
+}
+
+
+
+const struct macho_nlist* ImageLoaderMachOClassic::binarySearchWithToc(const char* key, const char stringPool[], const struct macho_nlist symbols[],
+ const struct dylib_table_of_contents toc[], uint32_t symbolCount, uint32_t hintIndex) const
+{
+ int32_t high = symbolCount-1;
+ int32_t mid = hintIndex;
+
+ // handle out of range hint
+ if ( mid >= (int32_t)symbolCount )
+ mid = symbolCount/2;
+ ++ImageLoaderMachO::fgSymbolTableBinarySearchs;
+ ++fgTotalBindImageSearches;
+
+ //dyld::log("dyld: binarySearchWithToc for %s in %s\n", key, this->getShortName());
+
+ for (int32_t low = 0; low <= high; mid = (low+high)/2) {
+ const uint32_t index = toc[mid].symbol_index;
+ const struct macho_nlist* pivot = &symbols[index];
+ const char* pivotStr = &stringPool[pivot->n_un.n_strx];
+#if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(&toc[mid]);
+ noteAccessedLinkEditAddress(pivot);
+ noteAccessedLinkEditAddress(pivotStr);
+#endif
+ int cmp = strcmp(key, pivotStr);
+ if ( cmp == 0 )
+ return pivot;
+ if ( cmp > 0 ) {
+ // key > pivot
+ low = mid + 1;
+ }
+ else {
+ // key < pivot
+ high = mid - 1;
+ }
+ }
+ return NULL;
+}
+
+const struct macho_nlist* ImageLoaderMachOClassic::binarySearch(const char* key, const char stringPool[], const struct macho_nlist symbols[], uint32_t symbolCount) const
+{
+ // update stats
+ ++fgTotalBindImageSearches;
+ ++ImageLoaderMachO::fgSymbolTableBinarySearchs;
+
+ //dyld::log("dyld: binarySearch for %s in %s, stringpool=%p, symbols=%p, symbolCount=%u\n",
+ // key, this->getShortName(), stringPool, symbols, symbolCount);
+
+ const struct macho_nlist* base = symbols;
+ for (uint32_t n = symbolCount; n > 0; n /= 2) {
+ const struct macho_nlist* pivot = &base[n/2];
+ const char* pivotStr = &stringPool[pivot->n_un.n_strx];
+#if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(pivot);
+ noteAccessedLinkEditAddress(pivotStr);
+#endif
+ int cmp = strcmp(key, pivotStr);
+ if ( cmp == 0 )
+ return pivot;
+ if ( cmp > 0 ) {
+ // key > pivot
+ // move base to symbol after pivot
+ base = &pivot[1];
+ --n;
+ }
+ else {
+ // key < pivot
+ // keep same base
+ }
+ }
+ return NULL;
+}
+
+
+const ImageLoader::Symbol* ImageLoaderMachOClassic::findShallowExportedSymbol(const char* name, const ImageLoader** foundIn) const
+{
+ const struct macho_nlist* sym = NULL;
+ if ( fDynamicInfo->tocoff == 0 )
+ sym = binarySearch(name, fStrings, &fSymbolTable[fDynamicInfo->iextdefsym], fDynamicInfo->nextdefsym);
+ else
+ sym = binarySearchWithToc(name, fStrings, fSymbolTable, (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff],
+ fDynamicInfo->ntoc, fDynamicInfo->nextdefsym);
+ if ( sym != NULL ) {
+ if ( foundIn != NULL )
+ *foundIn = (ImageLoader*)this;
+ return (const Symbol*)sym;
+ }
+ return NULL;
+}
+
+
+
+bool ImageLoaderMachOClassic::containsSymbol(const void* addr) const
+{
+ return ( (fSymbolTable <= addr) && (addr < fStrings) );
+}
+
+
+uintptr_t ImageLoaderMachOClassic::exportedSymbolAddress(const LinkContext& context, const Symbol* symbol, const ImageLoader* requestor, bool runResolver) const
+{
+ const struct macho_nlist* sym = (macho_nlist*)symbol;
+ uintptr_t result = sym->n_value + fSlide;
+ #if __arm__
+ // processor assumes code address with low bit set is thumb
+ if (sym->n_desc & N_ARM_THUMB_DEF)
+ result |= 1;
+ #endif
+ return result;
+}
+
+bool ImageLoaderMachOClassic::exportedSymbolIsWeakDefintion(const Symbol* symbol) const
+{
+ const struct macho_nlist* nlistSym = (const struct macho_nlist*)symbol;
+ return ( (nlistSym->n_desc & N_WEAK_DEF) != 0 );
+}
+
+const char* ImageLoaderMachOClassic::exportedSymbolName(const Symbol* symbol) const
+{
+ const struct macho_nlist* nlistSym = (const struct macho_nlist*)symbol;
+ return &fStrings[nlistSym->n_un.n_strx];
+}
+
+unsigned int ImageLoaderMachOClassic::exportedSymbolCount() const
+{
+ return fDynamicInfo->nextdefsym;
+}
+
+const ImageLoader::Symbol* ImageLoaderMachOClassic::exportedSymbolIndexed(unsigned int index) const
+{
+ if ( index < fDynamicInfo->nextdefsym ) {
+ const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iextdefsym + index];
+ return (const ImageLoader::Symbol*)sym;
+ }
+ return NULL;
+}
+
+unsigned int ImageLoaderMachOClassic::importedSymbolCount() const
+{
+ return fDynamicInfo->nundefsym;
+}
+
+const ImageLoader::Symbol* ImageLoaderMachOClassic::importedSymbolIndexed(unsigned int index) const
+{
+ if ( index < fDynamicInfo->nundefsym ) {
+ const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iundefsym + index];
+ return (const ImageLoader::Symbol*)sym;
+ }
+ return NULL;
+}
+
+const char* ImageLoaderMachOClassic::importedSymbolName(const Symbol* symbol) const
+{
+ const struct macho_nlist* nlistSym = (const struct macho_nlist*)symbol;
+ return &fStrings[nlistSym->n_un.n_strx];
+}
+
+
+
+bool ImageLoaderMachOClassic::symbolIsWeakDefinition(const struct macho_nlist* symbol)
+{
+ // if a define and weak ==> coalesced
+ if ( ((symbol->n_type & N_TYPE) == N_SECT) && ((symbol->n_desc & N_WEAK_DEF) != 0) )
+ return true;
+
+ // regular symbol
+ return false;
+}
+
+bool ImageLoaderMachOClassic::symbolIsWeakReference(const struct macho_nlist* symbol)
+{
+ // if an undefine and not referencing a weak symbol ==> coalesced
+ if ( ((symbol->n_type & N_TYPE) != N_SECT) && ((symbol->n_desc & N_REF_TO_WEAK) != 0) )
+ return true;
+
+ // regular symbol
+ return false;
+}
+
+uintptr_t ImageLoaderMachOClassic::getSymbolAddress(const macho_nlist* sym, const LinkContext& context, bool runResolver) const
+{
+ return ImageLoaderMachO::getSymbolAddress((Symbol*)sym, this, context, runResolver);
+}
+
+uintptr_t ImageLoaderMachOClassic::resolveUndefined(const LinkContext& context, const struct macho_nlist* undefinedSymbol,
+ bool twoLevel, bool dontCoalesce, bool runResolver, const ImageLoader** foundIn)
+{
+ ++fgTotalBindSymbolsResolved;
+ const char* symbolName = &fStrings[undefinedSymbol->n_un.n_strx];
+
+#if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(undefinedSymbol);
+ noteAccessedLinkEditAddress(symbolName);
+#endif
+ if ( context.bindFlat || !twoLevel ) {
+ // flat lookup
+ if ( ((undefinedSymbol->n_type & N_PEXT) != 0) && ((undefinedSymbol->n_type & N_TYPE) == N_SECT) ) {
+ // is a multi-module private_extern internal reference that the linker did not optimize away
+ uintptr_t addr = this->getSymbolAddress(undefinedSymbol, context, false);
+ *foundIn = this;
+ return addr;
+ }
+ const Symbol* sym;
+ if ( context.flatExportFinder(symbolName, &sym, foundIn) ) {
+ if ( *foundIn != this )
+ context.addDynamicReference(this, const_cast<ImageLoader*>(*foundIn));
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ }
+ // if a bundle is loaded privately the above will not find its exports
+ if ( this->isBundle() && this->hasHiddenExports() ) {
+ // look in self for needed symbol
+ sym = this->findShallowExportedSymbol(symbolName, foundIn);
+ if ( sym != NULL )
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ }
+ if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
+ // definition can't be found anywhere
+ // if reference is weak_import, then it is ok, just return 0
+ return 0;
+ }
+ throwSymbolNotFound(context, symbolName, this->getPath(), "", "flat namespace");
+ }
+ else {
+ // symbol requires searching images with coalesced symbols (not done during prebinding)
+ if ( !context.prebinding && !dontCoalesce && (symbolIsWeakReference(undefinedSymbol) || symbolIsWeakDefinition(undefinedSymbol)) ) {
+ const Symbol* sym;
+ if ( context.coalescedExportFinder(symbolName, &sym, foundIn, nullptr) ) {
+ if ( *foundIn != this )
+ context.addDynamicReference(this, const_cast<ImageLoader*>(*foundIn));
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ }
+ //throwSymbolNotFound(context, symbolName, this->getPath(), "coalesced namespace");
+ //dyld::log("dyld: coalesced symbol %s not found in any coalesced image, falling back to two-level lookup", symbolName);
+ }
+
+ // if this is a real definition (not an undefined symbol) there is no ordinal
+ if ( (undefinedSymbol->n_type & N_TYPE) == N_SECT ) {
+ // static linker should never generate this case, but if it does, do something sane
+ uintptr_t addr = this->getSymbolAddress(undefinedSymbol, context, false);
+ *foundIn = this;
+ return addr;
+ }
+
+ // two level lookup
+ ImageLoader* target = NULL;
+ uint8_t ord = GET_LIBRARY_ORDINAL(undefinedSymbol->n_desc);
+ if ( ord == EXECUTABLE_ORDINAL ) {
+ target = context.mainExecutable;
+ }
+ else if ( ord == SELF_LIBRARY_ORDINAL ) {
+ target = this;
+ }
+ else if ( ord == DYNAMIC_LOOKUP_ORDINAL ) {
+ // rnielsen: HACKHACK
+ // flat lookup
+ const Symbol* sym;
+ if ( context.flatExportFinder(symbolName, &sym, foundIn) )
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ // no image has exports this symbol
+ // report error
+ context.undefinedHandler(symbolName);
+ // try looking again
+ if ( context.flatExportFinder(symbolName, &sym, foundIn) )
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+
+ throwSymbolNotFound(context, symbolName, this->getPath(), "", "dynamic lookup");
+ }
+ else if ( ord <= libraryCount() ) {
+ target = libImage(ord-1);
+ if ( target == NULL ) {
+ // if target library not loaded and reference is weak or library is weak return 0
+ return 0;
+ }
+ }
+ else {
+ dyld::throwf("bad mach-o binary, library ordinal (%u) too big (max %u) for symbol %s in %s",
+ ord, libraryCount(), symbolName, this->getPath());
+ }
+
+ if ( target == NULL ) {
+ //dyld::log("resolveUndefined(%s) in %s\n", symbolName, this->getPath());
+ throw "symbol not found";
+ }
+
+ uintptr_t address;
+ if ( target->findExportedSymbolAddress(context, symbolName, this, ord, runResolver, foundIn, &address) )
+ return address;
+
+ if ( (undefinedSymbol->n_type & N_PEXT) != 0 ) {
+ // don't know why the static linker did not eliminate the internal reference to a private extern definition
+ *foundIn = this;
+ return this->getSymbolAddress(undefinedSymbol, context, false);
+ }
+ else if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
+ // if definition not found and reference is weak return 0
+ return 0;
+ }
+
+ // nowhere to be found
+ throwSymbolNotFound(context, symbolName, this->getPath(), "", target->getPath());
+ }
+}
+
+
+
+// returns if 'addr' is within the address range of section 'sectionIndex'
+// fSlide is not used. 'addr' is assumed to be a prebound address in this image
+bool ImageLoaderMachOClassic::isAddrInSection(uintptr_t addr, uint8_t sectionIndex)
+{
+ uint8_t currentSectionIndex = 1;
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ if ( (currentSectionIndex <= sectionIndex) && (sectionIndex < currentSectionIndex+seg->nsects) ) {
+ // 'sectionIndex' is in this segment, get section info
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const section = §ionsStart[sectionIndex-currentSectionIndex];
+ return ( (section->addr <= addr) && (addr < section->addr+section->size) );
+ }
+ else {
+ // 'sectionIndex' not in this segment, skip to next segment
+ currentSectionIndex += seg->nsects;
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+ return false;
+}
+
+void ImageLoaderMachOClassic::doBindExternalRelocations(const LinkContext& context)
+{
+ const uintptr_t relocBase = this->getRelocBase();
+ const bool twoLevel = this->usesTwoLevelNameSpace();
+ const bool prebound = this->isPrebindable();
+
+#if TEXT_RELOC_SUPPORT
+ // if there are __TEXT fixups, temporarily make __TEXT writable
+ if ( fTextSegmentBinds )
+ this->makeTextSegmentWritable(context, true);
+#endif
+ // cache last lookup
+ const struct macho_nlist* lastUndefinedSymbol = NULL;
+ uintptr_t symbolAddr = 0;
+ const ImageLoader* image = NULL;
+
+ // loop through all external relocation records and bind each
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ if (reloc->r_length == RELOC_SIZE) {
+ switch(reloc->r_type) {
+ case POINTER_RELOC:
+ {
+ const struct macho_nlist* undefinedSymbol = &fSymbolTable[reloc->r_symbolnum];
+ uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
+ if ( ! this->containsAddress((void*)location) )
+ dyld::throwf("external reloc %p not in mapped image %s\n", (void*)location, this->getPath());
+ uintptr_t value = *location;
+ bool symbolAddrCached = true;
+ #if __i386__
+ if ( reloc->r_pcrel ) {
+ value += (uintptr_t)location + 4 - fSlide;
+ }
+ #endif
+ if ( prebound ) {
+ // we are doing relocations, so prebinding was not usable
+ // in a prebound executable, the n_value field of an undefined symbol is set to the address where the symbol was found when prebound
+ // so, subtracting that gives the initial displacement which we need to add to the newly found symbol address
+ // if mach-o relocation structs had an "addend" field this complication would not be necessary.
+ if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_WEAK_DEF) != 0) ) {
+ // weak symbols need special casing, since *location may have been prebound to a definition in another image.
+ // If *location is currently prebound to somewhere in the same section as the weak definition, we assume
+ // that we can subtract off the weak symbol address to get the addend.
+ // If prebound elsewhere, we've lost the addend and have to assume it is zero.
+ // The prebinding to elsewhere only happens with 10.4+ update_prebinding which only operates on a small set of Apple dylibs
+ if ( (value == undefinedSymbol->n_value) || this->isAddrInSection(value, undefinedSymbol->n_sect) ) {
+ value -= undefinedSymbol->n_value;
+ #if __arm__
+ // if weak and thumb subtract off extra thumb bit
+ if ( (undefinedSymbol->n_desc & N_ARM_THUMB_DEF) != 0 )
+ value -= 1;
+ #endif
+ }
+ else
+ value = 0;
+ }
+ #if __arm__
+ else if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_ARM_THUMB_DEF) != 0) ) {
+ // it was prebound to a defined symbol for thumb code in the same linkage unit
+ // we need to subtract off one to get real addend
+ value -= (undefinedSymbol->n_value+1);
+ }
+ #endif
+ else {
+ // is undefined or non-weak symbol, so do subtraction to get addend
+ value -= undefinedSymbol->n_value;
+ }
+ }
+ // if undefinedSymbol is same as last time, then symbolAddr and image will resolve to the same too
+ if ( undefinedSymbol != lastUndefinedSymbol ) {
+ bool dontCoalesce = true;
+ if ( symbolIsWeakReference(undefinedSymbol) ) {
+ // when weakbind() is run on a classic mach-o encoding, it won't try
+ // to coalesce N_REF_TO_WEAK symbols because they are not in the sorted
+ // range of global symbols. To handle that case we do the coalesing now.
+ dontCoalesce = false;
+ }
+ symbolAddr = this->resolveUndefined(context, undefinedSymbol, twoLevel, dontCoalesce, false, &image);
+ lastUndefinedSymbol = undefinedSymbol;
+ symbolAddrCached = false;
+ }
+ if ( context.verboseBind && (undefinedSymbol != NULL) ) {
+ const char *path = NULL;
+ if ( image != NULL ) {
+ path = image->getShortName();
+ }
+ const char* cachedString = "(cached)";
+ if ( !symbolAddrCached )
+ cachedString = "";
+ if ( value == 0 ) {
+ dyld::log("dyld: bind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX%s\n",
+ this->getShortName(), (uintptr_t)location,
+ path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr, cachedString);
+ }
+ else {
+ dyld::log("dyld: bind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX%s + %ld\n",
+ this->getShortName(), (uintptr_t)location,
+ path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr, cachedString, value);
+ }
+ }
+ value += symbolAddr;
+ #if __i386__
+ if ( reloc->r_pcrel ) {
+ *location = value - ((uintptr_t)location + 4);
+ }
+ else {
+ // don't dirty page if prebound value was correct
+ if ( !prebound || (*location != value) )
+ *location = value;
+ }
+ #else
+ // don't dirty page if prebound value was correct
+ if ( !prebound || (*location != value) )
+ *location = value;
+ #endif
+ // update stats
+ ++fgTotalBindFixups;
+ }
+ break;
+ default:
+ throw "unknown external relocation type";
+ }
+ }
+ else {
+ throw "bad external relocation length";
+ }
+ }
+
+#if TEXT_RELOC_SUPPORT
+ // if there were __TEXT fixups, restore write protection
+ if ( fTextSegmentBinds ) {
+ this->makeTextSegmentWritable(context, true);
+ }
+#endif
+}
+
+
+
+uintptr_t ImageLoaderMachOClassic::bindIndirectSymbol(uintptr_t* ptrToBind, const struct macho_section* sect, const char* symbolName, uintptr_t targetAddr, const ImageLoader* targetImage, const LinkContext& context)
+{
+ if ( context.verboseBind ) {
+ const char* path = NULL;
+ if ( targetImage != NULL )
+ path = targetImage->getShortName();
+ dyld::log("dyld: bind indirect sym: %s:%s$%s = %s:%s, *0x%08lx = 0x%08lx\n",
+ this->getShortName(), symbolName, (((sect->flags & SECTION_TYPE)==S_NON_LAZY_SYMBOL_POINTERS) ? "non_lazy_ptr" : "lazy_ptr"),
+ ((path != NULL) ? path : "<weak_import-not-found>"), symbolName, (uintptr_t)ptrToBind, targetAddr);
+ }
+ if ( context.bindingHandler != NULL ) {
+ const char* path = NULL;
+ if ( targetImage != NULL )
+ path = targetImage->getShortName();
+ targetAddr = (uintptr_t)context.bindingHandler(path, symbolName, (void *)targetAddr);
+ }
+#if __i386__
+ // i386 has special self-modifying stubs that change from "CALL rel32" to "JMP rel32"
+ if ( ((sect->flags & SECTION_TYPE) == S_SYMBOL_STUBS) && ((sect->flags & S_ATTR_SELF_MODIFYING_CODE) != 0) && (sect->reserved2 == 5) ) {
+ uint32_t rel32 = targetAddr - (((uint32_t)ptrToBind)+5);
+ // re-write instruction in a thread-safe manner
+ // use 8-byte compare-and-swap to alter 5-byte jump table entries
+ // loop is required in case the extra three bytes that cover the next entry are altered by another thread
+ bool done = false;
+ while ( !done ) {
+ volatile int64_t* jumpPtr = (int64_t*)ptrToBind;
+ int pad = 0;
+ // By default the three extra bytes swapped follow the 5-byte JMP.
+ // But, if the 5-byte jump is up against the end of the __IMPORT segment
+ // We don't want to access bytes off the end of the segment, so we shift
+ // the extra bytes to precede the 5-byte JMP.
+ if ( (((uint32_t)ptrToBind + 8) & 0x00000FFC) == 0x00000000 ) {
+ jumpPtr = (int64_t*)((uint32_t)ptrToBind - 3);
+ pad = 3;
+ }
+ int64_t oldEntry = *jumpPtr;
+ union {
+ int64_t int64;
+ uint8_t bytes[8];
+ } newEntry;
+ newEntry.int64 = oldEntry;
+ newEntry.bytes[pad+0] = 0xE9; // JMP rel32
+ newEntry.bytes[pad+1] = rel32 & 0xFF;
+ newEntry.bytes[pad+2] = (rel32 >> 8) & 0xFF;
+ newEntry.bytes[pad+3] = (rel32 >> 16) & 0xFF;
+ newEntry.bytes[pad+4] = (rel32 >> 24) & 0xFF;
+ done = OSAtomicCompareAndSwap64Barrier(oldEntry, newEntry.int64, (int64_t*)jumpPtr);
+ }
+ }
+ else
+#endif
+ *ptrToBind = targetAddr;
+ return targetAddr;
+}
+
+uintptr_t ImageLoaderMachOClassic::doBindFastLazySymbol(uint32_t lazyBindingInfoOffset, const LinkContext& context, void (*lock)(), void (*unlock)())
+{
+ throw "compressed LINKEDIT lazy binder called with classic LINKEDIT";
+}
+
+uintptr_t ImageLoaderMachOClassic::doBindLazySymbol(uintptr_t* lazyPointer, const LinkContext& context)
+{
+ // scan for all lazy-pointer sections
+ const bool twoLevel = this->usesTwoLevelNameSpace();
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ uint32_t symbolIndex = INDIRECT_SYMBOL_LOCAL;
+ if ( type == S_LAZY_SYMBOL_POINTERS ) {
+ const size_t pointerCount = sect->size / sizeof(uintptr_t);
+ uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
+ if ( (lazyPointer >= symbolPointers) && (lazyPointer < &symbolPointers[pointerCount]) ) {
+ const uint32_t indirectTableOffset = sect->reserved1;
+ const size_t lazyIndex = lazyPointer - symbolPointers;
+ symbolIndex = indirectTable[indirectTableOffset + lazyIndex];
+ }
+ }
+ #if __i386__
+ else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
+ // 5 bytes stubs on i386 are new "fast stubs"
+ uint8_t* const jmpTableBase = (uint8_t*)(sect->addr + fSlide);
+ uint8_t* const jmpTableEnd = jmpTableBase + sect->size;
+ // initial CALL instruction in jump table leaves pointer to next entry, so back up
+ uint8_t* const jmpTableEntryToPatch = ((uint8_t*)lazyPointer) - 5;
+ lazyPointer = (uintptr_t*)jmpTableEntryToPatch;
+ if ( (jmpTableEntryToPatch >= jmpTableBase) && (jmpTableEntryToPatch < jmpTableEnd) ) {
+ const uint32_t indirectTableOffset = sect->reserved1;
+ const uint32_t entryIndex = (jmpTableEntryToPatch - jmpTableBase)/5;
+ symbolIndex = indirectTable[indirectTableOffset + entryIndex];
+ }
+ }
+ #endif
+ if ( symbolIndex != INDIRECT_SYMBOL_ABS && symbolIndex != INDIRECT_SYMBOL_LOCAL ) {
+ const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
+ const ImageLoader* image = NULL;
+ uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], twoLevel, false, true, &image);
+ symbolAddr = this->bindIndirectSymbol(lazyPointer, sect, symbolName, symbolAddr, image, context);
+ ++fgTotalLazyBindFixups;
+ return symbolAddr;
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ dyld::throwf("lazy pointer not found at address %p in image %s", lazyPointer, this->getPath());
+}
+
+
+
+void ImageLoaderMachOClassic::initializeCoalIterator(CoalIterator& it, unsigned int loadOrder, unsigned)
+{
+ it.image = this;
+ it.symbolName = " ";
+ it.loadOrder = loadOrder;
+ it.weakSymbol = false;
+ it.symbolMatches = false;
+ it.done = false;
+ it.type = 0;
+ if ( fDynamicInfo->tocoff != 0 ) {
+ it.curIndex = 0;
+ it.endIndex = fDynamicInfo->ntoc;
+ }
+ else {
+ it.curIndex = 0;
+ it.endIndex = fDynamicInfo->nextdefsym;
+ }
+}
+
+
+bool ImageLoaderMachOClassic::incrementCoalIterator(CoalIterator& it)
+{
+ if ( it.done )
+ return false;
+
+ if ( fDynamicInfo->tocoff != 0 ) {
+ if ( it.curIndex >= fDynamicInfo->ntoc ) {
+ it.done = true;
+ it.symbolName = "~~~";
+ return true;
+ }
+ else {
+ const dylib_table_of_contents* toc = (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff];
+ const uint32_t index = toc[it.curIndex].symbol_index;
+ const struct macho_nlist* sym = &fSymbolTable[index];
+ const char* symStr = &fStrings[sym->n_un.n_strx];
+ it.symbolName = symStr;
+ it.weakSymbol = (sym->n_desc & N_WEAK_DEF);
+ it.symbolMatches = false;
+ it.type = 0; // clear flag that says we applied updates for this symbol
+ //dyld::log("incrementCoalIterator() curIndex=%ld, symbolName=%s in %s\n", it.curIndex, symStr, this->getPath());
+ it.curIndex++;
+ return false;
+ }
+ }
+ else {
+ if ( it.curIndex >= fDynamicInfo->nextdefsym ) {
+ it.done = true;
+ it.symbolName = "~~~";
+ return true;
+ }
+ else {
+ const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iextdefsym+it.curIndex];
+ const char* symStr = &fStrings[sym->n_un.n_strx];
+ it.symbolName = symStr;
+ it.weakSymbol = (sym->n_desc & N_WEAK_DEF);
+ it.symbolMatches = false;
+ it.type = 0; // clear flag that says we applied updates for this symbol
+ //dyld::log("incrementCoalIterator() curIndex=%ld, symbolName=%s in %s\n", it.curIndex, symStr, this->getPath());
+ it.curIndex++;
+ return false;
+ }
+ }
+
+ return false;
+}
+
+uintptr_t ImageLoaderMachOClassic::getAddressCoalIterator(CoalIterator& it, const LinkContext& context)
+{
+ uint32_t symbol_index = 0;
+ if ( fDynamicInfo->tocoff != 0 ) {
+ const dylib_table_of_contents* toc = (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff];
+ symbol_index = toc[it.curIndex-1].symbol_index;
+ }
+ else {
+ symbol_index = fDynamicInfo->iextdefsym + (uint32_t)it.curIndex - 1;
+ }
+ const struct macho_nlist* sym = &fSymbolTable[symbol_index];
+ //dyld::log("getAddressCoalIterator() => 0x%llX, %s symbol_index=%d, in %s\n", (uint64_t)(sym->n_value + fSlide), &fStrings[sym->n_un.n_strx], symbol_index, this->getPath());
+#if __arm__
+ // processor assumes code address with low bit set is thumb
+ if (sym->n_desc & N_ARM_THUMB_DEF)
+ return (sym->n_value | 1) + fSlide ;
+ else
+ return sym->n_value + fSlide;
+#else
+ return sym->n_value + fSlide;
+#endif
+}
+
+
+void ImageLoaderMachOClassic::updateUsesCoalIterator(CoalIterator& it, uintptr_t value, ImageLoader* targetImage, unsigned targetIndex, const LinkContext& context)
+{
+ // flat_namespace images with classic LINKEDIT do not need late coalescing.
+ // They still need to be iterated becuase they may implement
+ // something needed by other coalescing images.
+ // But they need no updating because during the bind phase every symbol lookup is a full scan.
+ if ( !this->usesTwoLevelNameSpace() )
+ return;
+
+ // <rdar://problem/6570879> weak binding done too early with inserted libraries
+ if ( this->getState() < dyld_image_state_bound )
+ return;
+
+ uint32_t symbol_index = 0;
+ if ( fDynamicInfo->tocoff != 0 ) {
+ const dylib_table_of_contents* toc = (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff];
+ symbol_index = toc[it.curIndex-1].symbol_index;
+ }
+ else {
+ symbol_index = fDynamicInfo->iextdefsym + (uint32_t)it.curIndex - 1;
+ }
+
+ // if this image's copy of the symbol is not a weak definition nor a weak reference then nothing to coalesce here
+ if ( !symbolIsWeakReference(&fSymbolTable[symbol_index]) && !symbolIsWeakDefinition(&fSymbolTable[symbol_index]) ) {
+ return;
+ }
+
+ // <rdar://problem/6555720> malformed dylib with duplicate weak symbols causes re-binding
+ if ( it.type )
+ return;
+
+ bool boundSomething = false;
+ // scan external relocations for uses of symbol_index
+ const uintptr_t relocBase = this->getRelocBase();
+ const bool prebound = this->isPrebindable();
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ if ( reloc->r_symbolnum == symbol_index ) {
+ //dyld::log("found external reloc using symbol_index=%d in %s\n",symbol_index, this->getPath());
+ const struct macho_nlist* undefinedSymbol = &fSymbolTable[reloc->r_symbolnum];
+ const char* symbolName = &fStrings[undefinedSymbol->n_un.n_strx];
+ uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
+ const uintptr_t initialValue = *location;
+ uintptr_t addend = 0;
+ if ( prebound ) {
+ // we are doing relocations, so prebinding was not usable
+ // in a prebound executable, the n_value field of an undefined symbol is set to the address where the symbol was found when prebound
+ // so, subtracting that gives the initial displacement which we need to add to the newly found symbol address
+ // if mach-o relocation structs had an "addend" field this complication would not be necessary.
+ if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_WEAK_DEF) != 0) ) {
+ // weak symbols need special casing, since *location may have been prebound to a definition in another image.
+ // If *location is currently prebound to somewhere in the same section as the weak definition, we assume
+ // that we can subtract off the weak symbol address to get the addend.
+ // If prebound elsewhere, we've lost the addend and have to assume it is zero.
+ // The prebinding to elsewhere only happens with 10.4+ update_prebinding which only operates on a small set of Apple dylibs
+ if ( (initialValue == undefinedSymbol->n_value) || this->isAddrInSection(initialValue, undefinedSymbol->n_sect) ) {
+ addend = initialValue - undefinedSymbol->n_value;
+ #if __arm__
+ // if weak and thumb subtract off extra thumb bit
+ if ( (undefinedSymbol->n_desc & N_ARM_THUMB_DEF) != 0 )
+ addend &= -2;
+ #endif
+ }
+ }
+ #if __arm__
+ else if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_ARM_THUMB_DEF) != 0) ) {
+ // it was prebound to a defined symbol for thumb code in the same linkage unit
+ // we need to subtract off one to get real addend
+ addend = initialValue - (undefinedSymbol->n_value+1);
+ }
+ #endif
+ else {
+ // is undefined or non-weak symbol, so do subtraction to get addend
+ addend = initialValue - undefinedSymbol->n_value;
+ }
+ }
+ else {
+ // non-prebound case
+ if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_WEAK_DEF) != 0) ) {
+ // if target is weak-def in same linkage unit, then bind phase has already set initialValue
+ // to be definition address plus addend
+ //dyld::log("weak def, initialValue=0x%lX, undefAddr=0x%lX\n", initialValue, undefinedSymbol->n_value+fSlide);
+ addend = initialValue - (undefinedSymbol->n_value + fSlide);
+ #if __arm__
+ // if weak and thumb subtract off extra thumb bit
+ if ( (undefinedSymbol->n_desc & N_ARM_THUMB_DEF) != 0 )
+ addend &= -2;
+ #endif
+ }
+ else {
+ // nothing fixed up yet, addend is just initial value
+ //dyld::log("addend=0x%lX\n", initialValue);
+ addend = initialValue;
+ }
+ }
+
+ uint8_t type = BIND_TYPE_POINTER;
+ #if __i386__
+ if ( reloc->r_pcrel )
+ type = BIND_TYPE_TEXT_PCREL32;
+ #endif
+ this->bindLocation(context, this->imageBaseAddress(), (uintptr_t)location, value, type, symbolName, addend, this->getPath(), targetImage ? targetImage->getPath() : NULL, "weak ", NULL, fSlide);
+ boundSomething = true;
+ }
+ }
+
+ // scan lazy and non-lazy pointers for uses of symbol_index
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ uint32_t elementSize = sizeof(uintptr_t);
+ switch ( sect->flags & SECTION_TYPE ) {
+ #if __i386__
+ case S_SYMBOL_STUBS:
+ if ( ((sect->flags & S_ATTR_SELF_MODIFYING_CODE) ==0) || (sect->reserved2 != 5) )
+ continue;
+ elementSize = 5;
+ [[clang::fallthrough]];
+ #endif
+ case S_NON_LAZY_SYMBOL_POINTERS:
+ case S_LAZY_SYMBOL_POINTERS:
+ {
+ size_t elementCount = sect->size / elementSize;
+ const uint32_t indirectTableOffset = sect->reserved1;
+ uint8_t* ptrToBind = (uint8_t*)(sect->addr + fSlide);
+ //dyld::log(" scanning section %s of %s starting at %p\n", sect->sectname, this->getShortName(), ptrToBind);
+ for (size_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
+ if ( indirectTable[indirectTableOffset + j] == symbol_index ) {
+ //dyld::log(" found symbol index match at %d/%d, ptrToBind=%p\n", j, elementCount, ptrToBind);
+ // update pointer
+ this->bindIndirectSymbol((uintptr_t*)ptrToBind, sect, it.symbolName, value, targetImage, context);
+ boundSomething = true;
+ }
+ }
+ }
+ break;
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ if ( boundSomething && (targetImage != this) ) {
+ context.addDynamicReference(this, targetImage);
+ }
+
+ // mark that this symbol has already been bound, so we don't try to bind again
+ it.type = 1;
+}
+
+
+void ImageLoaderMachOClassic::bindIndirectSymbolPointers(const LinkContext& context, bool bindNonLazys, bool bindLazys)
+{
+ // scan for all non-lazy-pointer sections
+ const bool twoLevel = this->usesTwoLevelNameSpace();
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ bool isLazySymbol = false;
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ uint32_t elementSize = sizeof(uintptr_t);
+ size_t elementCount = sect->size / elementSize;
+ if ( type == S_NON_LAZY_SYMBOL_POINTERS ) {
+ if ( ! bindNonLazys )
+ continue;
+ }
+ else if ( type == S_LAZY_SYMBOL_POINTERS ) {
+ // process each symbol pointer in this section
+ fgTotalPossibleLazyBindFixups += elementCount;
+ isLazySymbol = true;
+ if ( ! bindLazys )
+ continue;
+ }
+ #if __i386__
+ else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
+ // process each jmp entry in this section
+ elementCount = sect->size / 5;
+ elementSize = 5;
+ fgTotalPossibleLazyBindFixups += elementCount;
+ isLazySymbol = true;
+ if ( ! bindLazys )
+ continue;
+ }
+ #endif
+ else {
+ continue;
+ }
+ const uint32_t indirectTableOffset = sect->reserved1;
+ uint8_t* ptrToBind = (uint8_t*)(sect->addr + fSlide);
+ for (size_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
+ #if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(&indirectTable[indirectTableOffset + j]);
+ #endif
+ uint32_t symbolIndex = indirectTable[indirectTableOffset + j];
+ if ( symbolIndex == INDIRECT_SYMBOL_LOCAL) {
+ *((uintptr_t*)ptrToBind) += this->fSlide;
+ }
+ else if ( symbolIndex == INDIRECT_SYMBOL_ABS) {
+ // do nothing since already has absolute address
+ }
+ else {
+ const struct macho_nlist* sym = &fSymbolTable[symbolIndex];
+ if ( symbolIndex == 0 ) {
+ // This could be rdar://problem/3534709
+ if ( ((const macho_header*)fMachOData)->filetype == MH_EXECUTE ) {
+ static bool alreadyWarned = false;
+ if ( (sym->n_type & N_TYPE) != N_UNDF ) {
+ // The indirect table parallels the (non)lazy pointer sections. For
+ // instance, to find info about the fifth lazy pointer you look at the
+ // fifth entry in the indirect table. (try otool -Iv on a file).
+ // The entry in the indirect table contains an index into the symbol table.
+
+ // The bug in ld caused the entry in the indirect table to be zero
+ // (instead of a magic value that means a local symbol). So, if the
+ // symbolIndex == 0, we may be encountering the bug, or 0 may be a valid
+ // symbol table index. The check I put in place is to see if the zero'th
+ // symbol table entry is an import entry (usually it is a local symbol
+ // definition).
+ if ( context.verboseWarnings && !alreadyWarned ) {
+ dyld::log("dyld: malformed executable '%s', skipping indirect symbol to %s\n",
+ this->getPath(), &fStrings[sym->n_un.n_strx]);
+ alreadyWarned = true;
+ }
+ continue;
+ }
+ }
+ }
+ const ImageLoader* image = NULL;
+ // let weak definitions resolve to themselves, later coalescing may overwrite them
+ bool dontCoalesce = true;
+ if ( bindLazys && isLazySymbol ) {
+ // if this is something normally lazy bound, but we are forcing
+ // it to be bound now, do coalescing
+ dontCoalesce = false;
+ }
+ if ( symbolIsWeakReference(sym) ) {
+ // when weakbind() is run on a classic mach-o encoding, it won't try
+ // to coalesce N_REF_TO_WEAK symbols because they are not in the sorted
+ // range of global symbols. To handle that case we do the coalesing now.
+ dontCoalesce = false;
+ }
+ uintptr_t symbolAddr = resolveUndefined(context, sym, twoLevel, dontCoalesce, false, &image);
+ // update pointer
+ this->bindIndirectSymbol((uintptr_t*)ptrToBind, sect, &fStrings[sym->n_un.n_strx], symbolAddr, image, context);
+ // update stats
+ ++fgTotalBindFixups;
+ }
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+
+
+
+#if __i386__
+void ImageLoaderMachOClassic::initializeLazyStubs(const LinkContext& context)
+{
+ if ( ! this->usablePrebinding(context) ) {
+ // reset all "fast" stubs
+ const macho_header* mh = (macho_header*)fMachOData;
+ const uint32_t cmd_count = mh->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
+ // reset each jmp entry in this section
+ const uint32_t indirectTableOffset = sect->reserved1;
+ const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
+ uint8_t* start = (uint8_t*)(sect->addr + this->fSlide);
+ uint8_t* end = start + sect->size;
+ uintptr_t dyldHandler = (uintptr_t)&stub_binding_helper_i386_old;
+ uint32_t entryIndex = 0;
+ for (uint8_t* entry = start; entry < end; entry += 5, ++entryIndex) {
+ bool installLazyHandler = true;
+ // jump table entries that cross a (64-byte) cache line boundary have the potential to cause crashes
+ // if the instruction is updated by one thread while being executed by another
+ if ( ((uint32_t)entry & 0xFFFFFFC0) != ((uint32_t)entry+4 & 0xFFFFFFC0) ) {
+ // need to bind this now to avoid a potential problem if bound lazily
+ uint32_t symbolIndex = indirectTable[indirectTableOffset + entryIndex];
+ // the latest linker marks 64-byte crossing stubs with INDIRECT_SYMBOL_ABS so they are not used
+ if ( symbolIndex != INDIRECT_SYMBOL_ABS ) {
+ const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
+ const ImageLoader* image = NULL;
+ try {
+ uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], this->usesTwoLevelNameSpace(), false, false, &image);
+ symbolAddr = this->bindIndirectSymbol((uintptr_t*)entry, sect, symbolName, symbolAddr, image, context);
+ ++fgTotalBindFixups;
+ uint32_t rel32 = symbolAddr - (((uint32_t)entry)+5);
+ entry[0] = 0xE9; // JMP rel32
+ entry[1] = rel32 & 0xFF;
+ entry[2] = (rel32 >> 8) & 0xFF;
+ entry[3] = (rel32 >> 16) & 0xFF;
+ entry[4] = (rel32 >> 24) & 0xFF;
+ installLazyHandler = false;
+ }
+ catch (const char* msg) {
+ // ignore errors when binding symbols early
+ // maybe the function is never called, and therefore erroring out now would be a regression
+ }
+ }
+ }
+ if ( installLazyHandler ) {
+ uint32_t rel32 = dyldHandler - (((uint32_t)entry)+5);
+ entry[0] = 0xE8; // CALL rel32
+ entry[1] = rel32 & 0xFF;
+ entry[2] = (rel32 >> 8) & 0xFF;
+ entry[3] = (rel32 >> 16) & 0xFF;
+ entry[4] = (rel32 >> 24) & 0xFF;
+ }
+ }
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+}
+#endif // __i386__
+
+
+void ImageLoaderMachOClassic::doBind(const LinkContext& context, bool forceLazysBound)
+{
+ CRSetCrashLogMessage2(this->getPath());
+#if __i386__
+ this->initializeLazyStubs(context);
+#endif
+
+ // if prebound and loaded at prebound address, and all libraries are same as when this was prebound, then no need to bind
+ // note: flat-namespace binaries need to have imports rebound (even if correctly prebound)
+ if ( this->usablePrebinding(context) ) {
+ // binding already up to date
+ }
+ else {
+ // no valid prebinding, so bind symbols.
+ // values bound by name are stored two different ways in classic mach-o:
+
+ #if TEXT_RELOC_SUPPORT
+ // if there are __TEXT fixups, temporarily make __TEXT writable
+ if ( fTextSegmentBinds )
+ this->makeTextSegmentWritable(context, true);
+ #endif
+
+ // 1) external relocations are used for data initialized to external symbols
+ this->doBindExternalRelocations(context);
+
+ // 2) "indirect symbols" are used for code references to external symbols
+ // if this image is in the shared cache, there is no way to reset the lazy pointers, so bind them now
+ this->bindIndirectSymbolPointers(context, true, forceLazysBound || fInSharedCache);
+
+ #if TEXT_RELOC_SUPPORT
+ // if there were __TEXT fixups, restore write protection
+ if ( fTextSegmentBinds )
+ this->makeTextSegmentWritable(context, false);
+ #endif
+ }
+
+ // set up dyld entry points in image
+ this->setupLazyPointerHandler(context);
+
+ CRSetCrashLogMessage2(NULL);
+}
+
+void ImageLoaderMachOClassic::doBindJustLazies(const LinkContext& context)
+{
+ // some API called requested that all lazy pointers in this image be force bound
+ this->bindIndirectSymbolPointers(context, false, true);
+}
+
+void ImageLoaderMachOClassic::doInterpose(const LinkContext& context)
+{
+ if ( context.verboseInterposing )
+ dyld::log("dyld: interposing %lu tuples onto: %s\n", fgInterposingTuples.size(), this->getPath());
+
+ // scan indirect symbols
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ if ( (type == S_NON_LAZY_SYMBOL_POINTERS) || (type == S_LAZY_SYMBOL_POINTERS) ) {
+ const size_t pointerCount = sect->size / sizeof(uintptr_t);
+ uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
+ for (size_t pointerIndex=0; pointerIndex < pointerCount; ++pointerIndex) {
+ uintptr_t newValue = interposedAddress(context, symbolPointers[pointerIndex], this);
+ if ( newValue != symbolPointers[pointerIndex] )
+ symbolPointers[pointerIndex] = newValue;
+ }
+ }
+ #if __i386__
+ // i386 has special self-modifying stubs that might be prebound to "JMP rel32" that need checking
+ else if ( (type == S_SYMBOL_STUBS) && ((sect->flags & S_ATTR_SELF_MODIFYING_CODE) != 0) && (sect->reserved2 == 5) ) {
+ // check each jmp entry in this section
+ uint8_t* start = (uint8_t*)(sect->addr + this->fSlide);
+ uint8_t* end = start + sect->size;
+ for (uint8_t* entry = start; entry < end; entry += 5) {
+ if ( entry[0] == 0xE9 ) { // 0xE9 == JMP
+ uint32_t rel32 = *((uint32_t*)&entry[1]); // assume unaligned load of uint32_t is ok
+ uint32_t target = (uint32_t)&entry[5] + rel32;
+ uint32_t newTarget = interposedAddress(context, target, this);
+ if ( newTarget != target ) {
+ uint32_t newRel32 = newTarget - (uint32_t)&entry[5];
+ *((uint32_t*)&entry[1]) = newRel32; // assume unaligned store of uint32_t is ok
+ }
+ }
+ }
+ }
+ #endif
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+ // scan external relocations
+ const uintptr_t relocBase = this->getRelocBase();
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ if (reloc->r_length == RELOC_SIZE) {
+ switch(reloc->r_type) {
+ case POINTER_RELOC:
+ {
+ uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
+ uintptr_t value = *location;
+ uintptr_t newValue = interposedAddress(context, value, this);
+ if ( newValue != value )
+ *location = newValue;
+ }
+ break;
+ }
+ }
+ }
+}
+
+void ImageLoaderMachOClassic::dynamicInterpose(const LinkContext& context)
+{
+ if ( context.verboseInterposing )
+ dyld::log("dyld: dynamic interposing %lu tuples onto image: %s\n", context.dynamicInterposeCount, this->getPath());
+
+ // scan indirect symbols
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ if ( (type == S_NON_LAZY_SYMBOL_POINTERS) || (type == S_LAZY_SYMBOL_POINTERS) ) {
+ const size_t pointerCount = sect->size / sizeof(uintptr_t);
+ uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
+ for (size_t pointerIndex=0; pointerIndex < pointerCount; ++pointerIndex) {
+ for(size_t j=0; j < context.dynamicInterposeCount; ++j) {
+ // replace all references to 'replacee' with 'replacement'
+ if ( symbolPointers[pointerIndex] == (uintptr_t)context.dynamicInterposeArray[j].replacee ) {
+ if ( context.verboseInterposing ) {
+ dyld::log("dyld: dynamic interposing: at %p replace %p with %p in %s\n",
+ &symbolPointers[pointerIndex], context.dynamicInterposeArray[j].replacee, context.dynamicInterposeArray[j].replacement, this->getPath());
+ }
+ symbolPointers[pointerIndex] = (uintptr_t)context.dynamicInterposeArray[j].replacement;
+ }
+ }
+ }
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+ // scan external relocations
+ const uintptr_t relocBase = this->getRelocBase();
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ if (reloc->r_length == RELOC_SIZE) {
+ switch(reloc->r_type) {
+ case POINTER_RELOC:
+ {
+ uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
+ for(size_t i=0; i < context.dynamicInterposeCount; ++i) {
+ // replace all references to 'replacee' with 'replacement'
+ if ( *location == (uintptr_t)context.dynamicInterposeArray[i].replacee ) {
+ if ( context.verboseInterposing ) {
+ dyld::log("dyld: dynamic interposing: at %p replace %p with %p in %s\n",
+ location, context.dynamicInterposeArray[i].replacee, context.dynamicInterposeArray[i].replacement, this->getPath());
+ }
+ *location = (uintptr_t)context.dynamicInterposeArray[i].replacement;
+ }
+ }
+ }
+ break;
+ }
+ }
+ }
+}
+
+
+const char* ImageLoaderMachOClassic::findClosestSymbol(const void* addr, const void** closestAddr) const
+{
+ uintptr_t targetAddress = (uintptr_t)addr - fSlide;
+ const struct macho_nlist* bestSymbol = NULL;
+ // first walk all global symbols
+ const struct macho_nlist* const globalsStart = &fSymbolTable[fDynamicInfo->iextdefsym];
+ const struct macho_nlist* const globalsEnd= &globalsStart[fDynamicInfo->nextdefsym];
+ for (const struct macho_nlist* s = globalsStart; s < globalsEnd; ++s) {
+ if ( (s->n_type & N_TYPE) == N_SECT ) {
+ if ( bestSymbol == NULL ) {
+ if ( s->n_value <= targetAddress )
+ bestSymbol = s;
+ }
+ else if ( (s->n_value <= targetAddress) && (bestSymbol->n_value < s->n_value) ) {
+ bestSymbol = s;
+ }
+ }
+ }
+ // next walk all local symbols
+ const struct macho_nlist* const localsStart = &fSymbolTable[fDynamicInfo->ilocalsym];
+ const struct macho_nlist* const localsEnd= &localsStart[fDynamicInfo->nlocalsym];
+ for (const struct macho_nlist* s = localsStart; s < localsEnd; ++s) {
+ if ( ((s->n_type & N_TYPE) == N_SECT) && ((s->n_type & N_STAB) == 0) ) {
+ if ( bestSymbol == NULL ) {
+ if ( s->n_value <= targetAddress )
+ bestSymbol = s;
+ }
+ else if ( (s->n_value <= targetAddress) && (bestSymbol->n_value < s->n_value) ) {
+ bestSymbol = s;
+ }
+ }
+ }
+ if ( bestSymbol != NULL ) {
+#if __arm__
+ if (bestSymbol->n_desc & N_ARM_THUMB_DEF)
+ *closestAddr = (void*)((bestSymbol->n_value | 1) + fSlide);
+ else
+ *closestAddr = (void*)(bestSymbol->n_value + fSlide);
+#else
+ *closestAddr = (void*)(bestSymbol->n_value + fSlide);
+#endif
+ return &fStrings[bestSymbol->n_un.n_strx];
+ }
+ return NULL;
+}
+
+