Loading...
--- /dev/null
+++ dyld/dyld-132.13/src/ImageLoaderMachO.cpp
@@ -0,0 +1,1717 @@
+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2004-2008 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/nlist.h>
+#include <sys/sysctl.h>
+#include <libkern/OSAtomic.h>
+#include <libkern/OSCacheControl.h>
+
+#include "ImageLoaderMachO.h"
+#include "ImageLoaderMachOCompressed.h"
+#include "ImageLoaderMachOClassic.h"
+#include "mach-o/dyld_images.h"
+
+
+
+// relocation_info.r_length field has value 3 for 64-bit executables and value 2 for 32-bit executables
+#if __LP64__
+ #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 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
+
+uint32_t ImageLoaderMachO::fgSymbolTableBinarySearchs = 0;
+uint32_t ImageLoaderMachO::fgSymbolTrieSearchs = 0;
+
+
+ImageLoaderMachO::ImageLoaderMachO(const macho_header* mh, const char* path, unsigned int segCount,
+ uint32_t segOffsets[], unsigned int libCount)
+ : ImageLoader(path, libCount), fMachOData((uint8_t*)mh), fLinkEditBase(NULL), fSlide(0),
+ fEHFrameSectionOffset(0), fUnwindInfoSectionOffset(0), fDylibIDOffset(0),
+ fSegmentsCount(segCount), fIsSplitSeg(false), fInSharedCache(false),
+#if TEXT_RELOC_SUPPORT
+ fTextSegmentRebases(false),
+ fTextSegmentBinds(false),
+#endif
+#if __i386__
+ fReadOnlyImportSegment(false),
+#endif
+ fHasSubLibraries(false), fHasSubUmbrella(false), fInUmbrella(false), fHasDOFSections(false), fHasDashInit(false),
+ fHasInitializers(false), fHasTerminators(false)
+{
+ fIsSplitSeg = ((mh->flags & MH_SPLIT_SEGS) != 0);
+
+ // construct SegmentMachO object for each LC_SEGMENT cmd using "placement new" to put
+ // each SegmentMachO object in array at end of ImageLoaderMachO object
+ 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, segIndex=0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
+ const struct macho_segment_command* segCmd = (struct macho_segment_command*)cmd;
+ // ignore zero-sized segments
+ if ( segCmd->vmsize != 0 ) {
+ // record offset of load command
+ segOffsets[segIndex++] = (uint8_t*)segCmd - fMachOData;
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+}
+
+
+// determine if this mach-o file has classic or compressed LINKEDIT and number of segments it has
+void ImageLoaderMachO::sniffLoadCommands(const macho_header* mh, const char* path, bool* compressed,
+ unsigned int* segCount, unsigned int* libCount)
+{
+ *compressed = false;
+ *segCount = 0;
+ *libCount = 0;
+ const uint32_t cmd_count = mh->ncmds;
+ const struct load_command* const cmds = (struct load_command*)(((uint8_t*)mh) + sizeof(macho_header));
+ const struct load_command* const endCmds = (struct load_command*)(((uint8_t*)mh) + sizeof(macho_header) + mh->sizeofcmds);
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_DYLD_INFO:
+ case LC_DYLD_INFO_ONLY:
+ *compressed = true;
+ break;
+ case LC_SEGMENT_COMMAND:
+ // ignore zero-sized segments
+ if ( ((struct macho_segment_command*)cmd)->vmsize != 0 )
+ *segCount += 1;
+ break;
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ *libCount += 1;
+ break;
+ }
+ uint32_t cmdLength = cmd->cmdsize;
+ cmd = (const struct load_command*)(((char*)cmd)+cmdLength);
+ if ( cmd > endCmds ) {
+ dyld::throwf("malformed mach-o image: load command #%d length (%u) would exceed sizeofcmds (%u) in %s",
+ i, cmdLength, mh->sizeofcmds, path);
+ }
+ }
+ // fSegmentsArrayCount is only 8-bits
+ if ( *segCount > 255 )
+ dyld::throwf("malformed mach-o image: more than 255 segments in %s", path);
+
+ // fSegmentsArrayCount is only 8-bits
+ if ( *libCount > 4095 )
+ dyld::throwf("malformed mach-o image: more than 4095 dependent libraries in %s", path);
+
+ if ( needsAddedLibSystemDepency(*libCount, mh) )
+ *libCount = 1;
+}
+
+
+
+// create image for main executable
+ImageLoader* ImageLoaderMachO::instantiateMainExecutable(const macho_header* mh, uintptr_t slide, const char* path, const LinkContext& context)
+{
+ //dyld::log("ImageLoader=%ld, ImageLoaderMachO=%ld, ImageLoaderMachOClassic=%ld, ImageLoaderMachOCompressed=%ld\n",
+ // sizeof(ImageLoader), sizeof(ImageLoaderMachO), sizeof(ImageLoaderMachOClassic), sizeof(ImageLoaderMachOCompressed));
+ bool compressed;
+ unsigned int segCount;
+ unsigned int libCount;
+ sniffLoadCommands(mh, path, &compressed, &segCount, &libCount);
+ // instantiate concrete class based on content of load commands
+ if ( compressed )
+ return ImageLoaderMachOCompressed::instantiateMainExecutable(mh, slide, path, segCount, libCount, context);
+ else
+ return ImageLoaderMachOClassic::instantiateMainExecutable(mh, slide, path, segCount, libCount, context);
+}
+
+
+// create image by mapping in a mach-o file
+ImageLoader* ImageLoaderMachO::instantiateFromFile(const char* path, int fd, const uint8_t firstPage[4096], uint64_t offsetInFat,
+ uint64_t lenInFat, const struct stat& info, const LinkContext& context)
+{
+ // get load commands
+ const unsigned int dataSize = sizeof(macho_header) + ((macho_header*)firstPage)->sizeofcmds;
+ uint8_t buffer[dataSize];
+ const uint8_t* fileData = firstPage;
+ if ( dataSize > 4096 ) {
+ // only read more if cmds take up more space than first page
+ fileData = buffer;
+ memcpy(buffer, firstPage, 4096);
+ pread(fd, &buffer[4096], dataSize-4096, offsetInFat+4096);
+ }
+
+ bool compressed;
+ unsigned int segCount;
+ unsigned int libCount;
+ sniffLoadCommands((const macho_header*)fileData, path, &compressed, &segCount, &libCount);
+ // instantiate concrete class based on content of load commands
+ if ( compressed )
+ return ImageLoaderMachOCompressed::instantiateFromFile(path, fd, fileData, offsetInFat, lenInFat, info, segCount, libCount, context);
+ else
+ return ImageLoaderMachOClassic::instantiateFromFile(path, fd, fileData, offsetInFat, lenInFat, info, segCount, libCount, context);
+}
+
+// create image by using cached mach-o file
+ImageLoader* ImageLoaderMachO::instantiateFromCache(const macho_header* mh, const char* path, const struct stat& info, const LinkContext& context)
+{
+ // instantiate right concrete class
+ bool compressed;
+ unsigned int segCount;
+ unsigned int libCount;
+ sniffLoadCommands(mh, path, &compressed, &segCount, &libCount);
+ // instantiate concrete class based on content of load commands
+ if ( compressed )
+ return ImageLoaderMachOCompressed::instantiateFromCache(mh, path, info, segCount, libCount, context);
+ else
+ return ImageLoaderMachOClassic::instantiateFromCache(mh, path, info, segCount, libCount, context);
+}
+
+// create image by copying an in-memory mach-o file
+ImageLoader* ImageLoaderMachO::instantiateFromMemory(const char* moduleName, const macho_header* mh, uint64_t len, const LinkContext& context)
+{
+ bool compressed;
+ unsigned int segCount;
+ unsigned int libCount;
+ sniffLoadCommands(mh, moduleName, &compressed, &segCount, &libCount);
+ // instantiate concrete class based on content of load commands
+ if ( compressed )
+ return ImageLoaderMachOCompressed::instantiateFromMemory(moduleName, mh, len, segCount, libCount, context);
+ else
+ return ImageLoaderMachOClassic::instantiateFromMemory(moduleName, mh, len, segCount, libCount, context);
+}
+
+
+
+void ImageLoaderMachO::parseLoadCmds()
+{
+ // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ // set up pointer to __LINKEDIT segment
+ if ( strcmp(segName(i),"__LINKEDIT") == 0 )
+ fLinkEditBase = (uint8_t*)(segActualLoadAddress(i) - segFileOffset(i));
+#if TEXT_RELOC_SUPPORT
+ // __TEXT segment always starts at beginning of file and contains mach_header and load commands
+ if ( strcmp(segName(i),"__TEXT") == 0 ) {
+ if ( segHasRebaseFixUps(i) )
+ fTextSegmentRebases = true;
+ if ( segHasBindFixUps(i) )
+ fTextSegmentBinds = true;
+ }
+#endif
+#if __i386__
+ if ( segIsReadOnlyImport(i) )
+ fReadOnlyImportSegment = true;
+#endif
+ // some segment always starts at beginning of file and contains mach_header and load commands
+ if ( (segFileOffset(i) == 0) && (segFileSize(i) != 0) ) {
+ fMachOData = (uint8_t*)(segActualLoadAddress(i));
+ }
+ }
+
+ // keep count of prebound images with weak exports
+ if ( this->participatesInCoalescing() ) {
+ ++fgImagesRequiringCoalescing;
+ if ( this->hasCoalescedExports() )
+ ++fgImagesHasWeakDefinitions;
+ }
+
+ // keep count of images used in shared cache
+ if ( fInSharedCache )
+ ++fgImagesUsedFromSharedCache;
+
+ // walk load commands (mapped in at start of __TEXT segment)
+ const dyld_info_command* dyldInfo = NULL;
+ const macho_nlist* symbolTable = NULL;
+ const char* symbolTableStrings = NULL;
+ const dysymtab_command* dynSymbolTable = 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_SYMTAB:
+ {
+ const struct symtab_command* symtab = (struct symtab_command*)cmd;
+ symbolTableStrings = (const char*)&fLinkEditBase[symtab->stroff];
+ symbolTable = (macho_nlist*)(&fLinkEditBase[symtab->symoff]);
+ }
+ break;
+ case LC_DYSYMTAB:
+ dynSymbolTable = (struct dysymtab_command*)cmd;
+ break;
+ case LC_SUB_UMBRELLA:
+ fHasSubUmbrella = true;
+ break;
+ case LC_SUB_FRAMEWORK:
+ fInUmbrella = true;
+ break;
+ case LC_SUB_LIBRARY:
+ fHasSubLibraries = true;
+ break;
+ case LC_ROUTINES_COMMAND:
+ fHasDashInit = true;
+ break;
+ case LC_DYLD_INFO:
+ case LC_DYLD_INFO_ONLY:
+ dyldInfo = (struct dyld_info_command*)cmd;
+ break;
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const bool isTextSeg = (strcmp(seg->segname, "__TEXT") == 0);
+ 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_MOD_INIT_FUNC_POINTERS )
+ fHasInitializers = true;
+ else if ( type == S_MOD_TERM_FUNC_POINTERS )
+ fHasTerminators = true;
+ else if ( type == S_DTRACE_DOF )
+ fHasDOFSections = true;
+ else if ( isTextSeg && (strcmp(sect->sectname, "__eh_frame") == 0) )
+ fEHFrameSectionOffset = (uint8_t*)sect - fMachOData;
+ else if ( isTextSeg && (strcmp(sect->sectname, "__unwind_info") == 0) )
+ fUnwindInfoSectionOffset = (uint8_t*)sect - fMachOData;;
+ }
+ }
+ break;
+ case LC_TWOLEVEL_HINTS:
+ // no longer supported
+ break;
+ case LC_ID_DYLIB:
+ {
+ fDylibIDOffset = (uint8_t*)cmd - fMachOData;
+ }
+ break;
+ case LC_RPATH:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ // do nothing, just prevent LC_REQ_DYLD exception from occuring
+ break;
+ default:
+ if ( (cmd->cmd & LC_REQ_DYLD) != 0 )
+ dyld::throwf("unknown required load command 0x%08X", cmd->cmd);
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+ if ( dyldInfo != NULL )
+ this->setDyldInfo(dyldInfo);
+ if ( symbolTable != NULL)
+ this->setSymbolTableInfo(symbolTable, symbolTableStrings, dynSymbolTable);
+
+}
+
+// don't do this work in destructor because we need object to be full subclass
+// for UnmapSegments() to work
+void ImageLoaderMachO::destroy()
+{
+ // keep count of images with weak exports
+ if ( this->participatesInCoalescing() ) {
+ --fgImagesRequiringCoalescing;
+ if ( this->hasCoalescedExports() )
+ --fgImagesHasWeakDefinitions;
+ }
+
+ // keep count of images used in shared cache
+ if ( fInSharedCache )
+ --fgImagesUsedFromSharedCache;
+
+ // unmap image when done
+ UnmapSegments();
+}
+
+
+unsigned int ImageLoaderMachO::segmentCount() const
+{
+ return fSegmentsCount;
+}
+
+
+const macho_segment_command* ImageLoaderMachO::segLoadCommand(unsigned int segIndex) const
+{
+ uint32_t* lcOffsets = this->segmentCommandOffsets();
+ uint32_t lcOffset = lcOffsets[segIndex];
+ return (macho_segment_command*)(&fMachOData[lcOffset]);
+}
+
+const char* ImageLoaderMachO::segName(unsigned int segIndex) const
+{
+ return segLoadCommand(segIndex)->segname;
+}
+
+
+uintptr_t ImageLoaderMachO::segSize(unsigned int segIndex) const
+{
+ return segLoadCommand(segIndex)->vmsize;
+}
+
+
+uintptr_t ImageLoaderMachO::segFileSize(unsigned int segIndex) const
+{
+ return segLoadCommand(segIndex)->filesize;
+}
+
+
+bool ImageLoaderMachO::segHasTrailingZeroFill(unsigned int segIndex)
+{
+ return ( segWriteable(segIndex) && (segSize(segIndex) > segFileSize(segIndex)) );
+}
+
+
+uintptr_t ImageLoaderMachO::segFileOffset(unsigned int segIndex) const
+{
+ return segLoadCommand(segIndex)->fileoff;
+}
+
+
+bool ImageLoaderMachO::segReadable(unsigned int segIndex) const
+{
+ return ( (segLoadCommand(segIndex)->initprot & VM_PROT_READ) != 0);
+}
+
+
+bool ImageLoaderMachO::segWriteable(unsigned int segIndex) const
+{
+ return ( (segLoadCommand(segIndex)->initprot & VM_PROT_WRITE) != 0);
+}
+
+
+bool ImageLoaderMachO::segExecutable(unsigned int segIndex) const
+{
+ return ( (segLoadCommand(segIndex)->initprot & VM_PROT_EXECUTE) != 0);
+}
+
+
+bool ImageLoaderMachO::segUnaccessible(unsigned int segIndex) const
+{
+ return (segLoadCommand(segIndex)->initprot == 0);
+}
+
+bool ImageLoaderMachO::segHasPreferredLoadAddress(unsigned int segIndex) const
+{
+ return (segLoadCommand(segIndex)->vmaddr != 0);
+}
+
+uintptr_t ImageLoaderMachO::segPreferredLoadAddress(unsigned int segIndex) const
+{
+ return segLoadCommand(segIndex)->vmaddr;
+}
+
+uintptr_t ImageLoaderMachO::segActualLoadAddress(unsigned int segIndex) const
+{
+ return segLoadCommand(segIndex)->vmaddr + fSlide;
+}
+
+
+uintptr_t ImageLoaderMachO::segActualEndAddress(unsigned int segIndex) const
+{
+ return segActualLoadAddress(segIndex) + segSize(segIndex);
+}
+
+bool ImageLoaderMachO::segHasRebaseFixUps(unsigned int segIndex) const
+{
+ // scan sections for fix-up bit
+ const macho_segment_command* segCmd = segLoadCommand(segIndex);
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)segCmd + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[segCmd->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( (sect->flags & S_ATTR_LOC_RELOC) != 0 )
+ return true;
+ }
+ return false;
+}
+
+bool ImageLoaderMachO::segHasBindFixUps(unsigned int segIndex) const
+{
+ // scan sections for fix-up bit
+ const macho_segment_command* segCmd = segLoadCommand(segIndex);
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)segCmd + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[segCmd->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( (sect->flags & S_ATTR_EXT_RELOC) != 0 )
+ return true;
+ }
+ return false;
+}
+
+#if __i386__
+bool ImageLoaderMachO::segIsReadOnlyImport(unsigned int segIndex) const
+{
+ const macho_segment_command* segCmd = segLoadCommand(segIndex);
+ return ( (segCmd->initprot & VM_PROT_EXECUTE)
+ && ((segCmd->initprot & VM_PROT_WRITE) == 0)
+ && (strcmp(segCmd->segname, "__IMPORT") == 0) );
+}
+#endif
+
+
+void ImageLoaderMachO::UnmapSegments()
+{
+ // usually unmap image when done
+ if ( ! this->leaveMapped() && (this->getState() >= dyld_image_state_mapped) ) {
+ // unmap TEXT segment last because it contains load command being inspected
+ unsigned int textSegmentIndex = 0;
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ //dyld::log("unmap %s at 0x%08lX\n", seg->getName(), seg->getActualLoadAddress(this));
+ if ( strcmp(segName(i), "__TEXT") == 0 ) {
+ textSegmentIndex = i;
+ }
+ else {
+ // update stats
+ --ImageLoader::fgTotalSegmentsMapped;
+ ImageLoader::fgTotalBytesMapped -= segSize(i);
+ munmap((void*)segActualLoadAddress(i), segSize(i));
+ }
+ }
+ // now unmap TEXT
+ --ImageLoader::fgTotalSegmentsMapped;
+ ImageLoader::fgTotalBytesMapped -= segSize(textSegmentIndex);
+ munmap((void*)segActualLoadAddress(textSegmentIndex), segSize(textSegmentIndex));
+ }
+}
+
+
+// prefetch __DATA/__OBJC pages during launch, but not for dynamically loaded code
+void ImageLoaderMachO::preFetchDATA(int fd, uint64_t offsetInFat, const LinkContext& context)
+{
+ if ( context.linkingMainExecutable ) {
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ if ( segWriteable(i) && (segFileSize(i) > 0) ) {
+ // prefetch writable segment that have mmap'ed regions
+ radvisory advice;
+ advice.ra_offset = offsetInFat + segFileOffset(i);
+ advice.ra_count = segFileSize(i);
+ // limit prefetch to 1MB (256 pages)
+ if ( advice.ra_count > 1024*1024 )
+ advice.ra_count = 1024*1024;
+ // don't prefetch single pages, let them fault in
+ fgTotalBytesPreFetched += advice.ra_count;
+ fcntl(fd, F_RDADVISE, &advice);
+ if ( context.verboseMapping ) {
+ dyld::log("%18s prefetching 0x%0lX -> 0x%0lX\n",
+ segName(i), segActualLoadAddress(i), segActualLoadAddress(i)+advice.ra_count-1);
+ }
+ }
+ }
+ }
+}
+
+
+bool ImageLoaderMachO::segmentsMustSlideTogether() const
+{
+ return true;
+}
+
+bool ImageLoaderMachO::segmentsCanSlide() const
+{
+ return (this->isDylib() || this->isBundle() || this->isPositionIndependentExecutable());
+}
+
+bool ImageLoaderMachO::isBundle() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( mh->filetype == MH_BUNDLE );
+}
+
+bool ImageLoaderMachO::isDylib() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( mh->filetype == MH_DYLIB );
+}
+
+bool ImageLoaderMachO::isExecutable() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( mh->filetype == MH_EXECUTE );
+}
+
+bool ImageLoaderMachO::isPositionIndependentExecutable() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->filetype == MH_EXECUTE) && ((mh->flags & MH_PIE) != 0) );
+}
+
+
+bool ImageLoaderMachO::forceFlat() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_FORCE_FLAT) != 0 );
+}
+
+bool ImageLoaderMachO::usesTwoLevelNameSpace() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_TWOLEVEL) != 0 );
+}
+
+bool ImageLoaderMachO::isPrebindable() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_PREBOUND) != 0 );
+}
+
+bool ImageLoaderMachO::hasCoalescedExports() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_WEAK_DEFINES) != 0 );
+}
+
+bool ImageLoaderMachO::hasReferencesToWeakSymbols() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_BINDS_TO_WEAK) != 0 );
+}
+
+bool ImageLoaderMachO::participatesInCoalescing() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ // if image is loaded with RTLD_LOCAL, then its symbols' visibility
+ // is reduced and it can't coalesce with other images
+ if ( this->hasHiddenExports() )
+ return false;
+ return ( (mh->flags & (MH_WEAK_DEFINES|MH_BINDS_TO_WEAK)) != 0 );
+}
+
+
+
+void ImageLoaderMachO::setSlide(intptr_t slide)
+{
+ fSlide = slide;
+}
+
+#if CODESIGNING_SUPPORT
+void ImageLoaderMachO::loadCodeSignature(const uint8_t* fileData, int fd, uint64_t offsetInFatFile)
+{
+ // look for code signature load command
+ // do this in the read() memory buffer - not in the mapped __TEXT segment
+ const uint32_t cmd_count = ((macho_header*)fileData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fileData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_CODE_SIGNATURE ) {
+ const struct linkedit_data_command *sigcmd = (struct linkedit_data_command*) cmd;
+ // fLinkEditBase is not set up yet, so compute it
+ const uint8_t* linkEditBase = NULL;
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ // set up pointer to __LINKEDIT segment
+ if ( strcmp(segName(i),"__LINKEDIT") == 0 ) {
+ linkEditBase = (uint8_t*)(segActualLoadAddress(i) - segFileOffset(i));
+ break;
+ }
+ }
+ fsignatures_t siginfo;
+ siginfo.fs_file_start=offsetInFatFile; // CD coverage offset
+ siginfo.fs_blob_start=(void*)(linkEditBase+sigcmd->dataoff); // start of CD in file
+ siginfo.fs_blob_size=sigcmd->datasize; // size of CD
+ int result = fcntl(fd, F_ADDSIGS, &siginfo);
+ if ( result == -1 )
+ dyld::log("dyld: code signature failed for %s with errno=%d\n", this->getPath(), errno);
+ break; // only support one LC_CODE_SIGNATURE
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+#endif
+
+
+const char* ImageLoaderMachO::getInstallPath() const
+{
+ if ( fDylibIDOffset != 0 ) {
+ const dylib_command* dylibID = (dylib_command*)(&fMachOData[fDylibIDOffset]);
+ return (char*)dylibID + dylibID->dylib.name.offset;
+ }
+ return NULL;
+}
+
+
+
+void* ImageLoaderMachO::getMain() const
+{
+ 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_UNIXTHREAD:
+ {
+ #if __ppc__
+ const ppc_thread_state_t* registers = (ppc_thread_state_t*)(((char*)cmd) + 16);
+ return (void*)(registers->srr0 + fSlide);
+ #elif __ppc64__
+ const ppc_thread_state64_t* registers = (ppc_thread_state64_t*)(((char*)cmd) + 16);
+ return (void*)(registers->srr0 + fSlide);
+ #elif __i386__
+ const i386_thread_state_t* registers = (i386_thread_state_t*)(((char*)cmd) + 16);
+ return (void*)(registers->eip + fSlide);
+ #elif __x86_64__
+ const x86_thread_state64_t* registers = (x86_thread_state64_t*)(((char*)cmd) + 16);
+ return (void*)(registers->rip + fSlide);
+ #elif __arm__
+ const arm_thread_state_t* registers = (arm_thread_state_t*)(((char*)cmd) + 16);
+ return (void*)(registers->__pc + fSlide);
+ #else
+ #warning need processor specific code
+ #endif
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ return NULL;
+}
+
+bool ImageLoaderMachO::needsAddedLibSystemDepency(unsigned int libCount, const macho_header* mh)
+{
+ // <rdar://problem/6357561> ensure that every image depends on something which depends on libSystem
+ if ( libCount > 1 )
+ return false;
+
+ // <rdar://problem/6409800> dyld implicit-libSystem breaks valgrind
+ if ( mh->filetype == MH_EXECUTE )
+ return false;
+
+ bool isNonOSdylib = false;
+ const uint32_t cmd_count = mh->ncmds;
+ const struct load_command* const cmds = (struct load_command*)((uint8_t*)mh+sizeof(macho_header));
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ return false;
+ case LC_ID_DYLIB:
+ {
+ const dylib_command* dylibID = (dylib_command*)cmd;
+ const char* installPath = (char*)cmd + dylibID->dylib.name.offset;
+ // It is OK for OS dylibs (libSystem or libmath or Rosetta shims) to have no dependents
+ // but all other dylibs must depend on libSystem for initialization to initialize libSystem first
+ // <rdar://problem/6497528> rosetta circular dependency spew
+ isNonOSdylib = ( (strncmp(installPath, "/usr/lib/", 9) != 0) && (strncmp(installPath, "/usr/libexec/oah/Shims", 9) != 0) );
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ return isNonOSdylib;
+}
+
+
+void ImageLoaderMachO::doGetDependentLibraries(DependentLibraryInfo libs[])
+{
+ if ( needsAddedLibSystemDepency(libraryCount(), (macho_header*)fMachOData) ) {
+ DependentLibraryInfo* lib = &libs[0];
+ lib->name = "/usr/lib/libSystem.B.dylib";
+ lib->info.checksum = 0;
+ lib->info.minVersion = 0;
+ lib->info.maxVersion = 0;
+ lib->required = false;
+ lib->reExported = false;
+ }
+ else {
+ uint32_t index = 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_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ {
+ const struct dylib_command* dylib = (struct dylib_command*)cmd;
+ DependentLibraryInfo* lib = &libs[index++];
+ lib->name = (char*)cmd + dylib->dylib.name.offset;
+ //lib->name = strdup((char*)cmd + dylib->dylib.name.offset);
+ lib->info.checksum = dylib->dylib.timestamp;
+ lib->info.minVersion = dylib->dylib.compatibility_version;
+ lib->info.maxVersion = dylib->dylib.current_version;
+ lib->required = (cmd->cmd != LC_LOAD_WEAK_DYLIB);
+ lib->reExported = (cmd->cmd == LC_REEXPORT_DYLIB);
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+}
+
+ImageLoader::LibraryInfo ImageLoaderMachO::doGetLibraryInfo()
+{
+ LibraryInfo info;
+ if ( fDylibIDOffset != 0 ) {
+ const dylib_command* dylibID = (dylib_command*)(&fMachOData[fDylibIDOffset]);
+ info.minVersion = dylibID->dylib.compatibility_version;
+ info.maxVersion = dylibID->dylib.current_version;
+ info.checksum = dylibID->dylib.timestamp;
+ }
+ else {
+ info.minVersion = 0;
+ info.maxVersion = 0;
+ info.checksum = 0;
+ }
+ return info;
+}
+
+void ImageLoaderMachO::getRPaths(const LinkContext& context, std::vector<const char*>& paths) const
+{
+ 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_RPATH:
+ const char* path = (char*)cmd + ((struct rpath_command*)cmd)->path.offset;
+ if ( strncmp(path, "@loader_path/", 13) == 0 ) {
+ if ( context.processIsRestricted && (context.mainExecutable == this) ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in restricted program because of @loader_path\n", path, this->getPath());
+ break;
+ }
+ char resolvedPath[PATH_MAX];
+ if ( realpath(this->getPath(), resolvedPath) != NULL ) {
+ char newRealPath[strlen(resolvedPath) + strlen(path)];
+ strcpy(newRealPath, resolvedPath);
+ char* addPoint = strrchr(newRealPath,'/');
+ if ( addPoint != NULL )
+ strcpy(&addPoint[1], &path[13]);
+ else
+ strcpy(newRealPath, &path[13]);
+ path = strdup(newRealPath);
+ }
+ }
+ else if ( strncmp(path, "@executable_path/", 17) == 0 ) {
+ if ( context.processIsRestricted ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in restricted program because of @executable_path\n", path, this->getPath());
+ break;
+ }
+ char resolvedPath[PATH_MAX];
+ if ( realpath(context.mainExecutable->getPath(), resolvedPath) != NULL ) {
+ char newRealPath[strlen(resolvedPath) + strlen(path)];
+ strcpy(newRealPath, resolvedPath);
+ char* addPoint = strrchr(newRealPath,'/');
+ if ( addPoint != NULL )
+ strcpy(&addPoint[1], &path[17]);
+ else
+ strcpy(newRealPath, &path[17]);
+ path = strdup(newRealPath);
+ }
+ }
+ else if ( (path[0] != '/') && context.processIsRestricted ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in restricted program because it is a relative path\n", path, this->getPath());
+ break;
+ }
+ else if ( (path[0] == '/') && (context.rootPaths != NULL) ) {
+ // <rdar://problem/5869973> DYLD_ROOT_PATH should apply to LC_RPATH rpaths
+ // DYLD_ROOT_PATH can be a list of paths, but at this point we can only support one, so use first combination that exists
+ bool found = false;
+ for(const char** rp = context.rootPaths; *rp != NULL; ++rp) {
+ char newPath[PATH_MAX];
+ strcpy(newPath, *rp);
+ strcat(newPath, path);
+ struct stat stat_buf;
+ if ( stat(newPath, &stat_buf) != -1 ) {
+ //dyld::log("combined DYLD_ROOT_PATH and LC_RPATH: %s\n", newPath);
+ path = strdup(newPath);
+ found = true;
+ break;
+ }
+ }
+ if ( ! found ) {
+ // make copy so that all elements of 'paths' can be freed
+ path = strdup(path);
+ }
+ }
+ else {
+ // make copy so that all elements of 'paths' can be freed
+ path = strdup(path);
+ }
+ paths.push_back(path);
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+
+bool ImageLoaderMachO::getUUID(uuid_t uuid) const
+{
+ 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_UUID:
+ uuid_command* uc = (uuid_command*)cmd;
+ memcpy(uuid, uc->uuid, 16);
+ return true;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ bzero(uuid, 16);
+ return false;
+}
+
+void ImageLoaderMachO::doRebase(const LinkContext& context)
+{
+ // if prebound and loaded at prebound address, then no need to rebase
+ if ( this->usablePrebinding(context) ) {
+ // skip rebasing because prebinding is valid
+ ++fgImagesWithUsedPrebinding; // bump totals for statistics
+ return;
+ }
+
+ // print why prebinding was not used
+ if ( context.verbosePrebinding ) {
+ if ( !this->isPrebindable() ) {
+ dyld::log("dyld: image not prebound, so could not use prebinding in %s\n", this->getPath());
+ }
+ else if ( fSlide != 0 ) {
+ dyld::log("dyld: image slid, so could not use prebinding in %s\n", this->getPath());
+ }
+ else if ( !this->allDependentLibrariesAsWhenPreBound() ) {
+ dyld::log("dyld: dependent libraries changed, so could not use prebinding in %s\n", this->getPath());
+ }
+ else if ( !this->usesTwoLevelNameSpace() ){
+ dyld::log("dyld: image uses flat-namespace so, parts of prebinding ignored %s\n", this->getPath());
+ }
+ else {
+ dyld::log("dyld: environment variable disabled use of prebinding in %s\n", this->getPath());
+ }
+ }
+
+ //dyld::log("slide=0x%08lX for %s\n", slide, this->getPath());
+
+#if PREBOUND_IMAGE_SUPPORT
+ // if prebound and we got here, then prebinding is not valid, so reset all lazy pointers
+ // if this image is in the shared cache, do not reset, they will be bound in doBind()
+ if ( this->isPrebindable() && !fInSharedCache )
+ this->resetPreboundLazyPointers(context);
+#endif
+
+ // if loaded at preferred address, no rebasing necessary
+ if ( this->fSlide == 0 )
+ return;
+
+#if TEXT_RELOC_SUPPORT
+ // if there are __TEXT fixups, temporarily make __TEXT writable
+ if ( fTextSegmentRebases )
+ this->makeTextSegmentWritable(context, true);
+#endif
+
+ // do actual rebasing
+ this->rebase(context);
+
+#if TEXT_RELOC_SUPPORT
+ // if there were __TEXT fixups, restore write protection
+ if ( fTextSegmentRebases )
+ this->makeTextSegmentWritable(context, false);
+
+#endif
+}
+
+#if TEXT_RELOC_SUPPORT
+void ImageLoaderMachO::makeTextSegmentWritable(const LinkContext& context, bool writeable)
+{
+ int textSegmentIndex = 0;
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ if ( strcmp(segName(i), "__TEXT") == 0 ) {
+ textSegmentIndex = i;
+ break;
+ }
+ }
+
+ if ( writeable ) {
+ segMakeWritable(textSegmentIndex, context);
+ }
+ else {
+ segProtect(textSegmentIndex, context);
+ sys_icache_invalidate((void*)segActualLoadAddress(textSegmentIndex), segSize(textSegmentIndex));
+ }
+}
+#endif
+
+const ImageLoader::Symbol* ImageLoaderMachO::findExportedSymbol(const char* name, bool searchReExports, const ImageLoader** foundIn) const
+{
+ // look in this image first
+ const ImageLoader::Symbol* result = this->findExportedSymbol(name, foundIn);
+ if ( result != NULL )
+ return result;
+
+ if ( searchReExports ) {
+ for(unsigned int i=0; i < libraryCount(); ++i){
+ if ( libReExported(i) ) {
+ ImageLoader* image = libImage(i);
+ if ( image != NULL ) {
+ const Symbol* result = image->findExportedSymbol(name, searchReExports, foundIn);
+ if ( result != NULL )
+ return result;
+ }
+ }
+ }
+ }
+
+
+ return NULL;
+}
+
+
+
+uintptr_t ImageLoaderMachO::getExportedSymbolAddress(const Symbol* sym, const LinkContext& context, const ImageLoader* requestor) const
+{
+ return this->getSymbolAddress(sym, requestor, context);
+}
+
+uintptr_t ImageLoaderMachO::getSymbolAddress(const Symbol* sym, const ImageLoader* requestor, const LinkContext& context) const
+{
+ uintptr_t result = exportedSymbolAddress(sym);
+ return result;
+}
+
+ImageLoader::DefinitionFlags ImageLoaderMachO::getExportedSymbolInfo(const Symbol* sym) const
+{
+ if ( exportedSymbolIsWeakDefintion(sym) )
+ return kWeakDefinition;
+ else
+ return kNoDefinitionOptions;
+}
+
+const char* ImageLoaderMachO::getExportedSymbolName(const Symbol* sym) const
+{
+ return exportedSymbolName(sym);
+}
+
+uint32_t ImageLoaderMachO::getExportedSymbolCount() const
+{
+ return exportedSymbolCount();
+}
+
+
+const ImageLoader::Symbol* ImageLoaderMachO::getIndexedExportedSymbol(uint32_t index) const
+{
+ return exportedSymbolIndexed(index);
+}
+
+
+uint32_t ImageLoaderMachO::getImportedSymbolCount() const
+{
+ return importedSymbolCount();
+}
+
+
+const ImageLoader::Symbol* ImageLoaderMachO::getIndexedImportedSymbol(uint32_t index) const
+{
+ return importedSymbolIndexed(index);
+}
+
+
+ImageLoader::ReferenceFlags ImageLoaderMachO::getImportedSymbolInfo(const ImageLoader::Symbol* sym) const
+{
+ ImageLoader::ReferenceFlags flags = kNoReferenceOptions;
+ return flags;
+}
+
+
+const char* ImageLoaderMachO::getImportedSymbolName(const ImageLoader::Symbol* sym) const
+{
+ return importedSymbolName(sym);
+}
+
+
+bool ImageLoaderMachO::getSectionContent(const char* segmentName, const char* sectionName, void** start, size_t* length)
+{
+ 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) {
+ if ( (strcmp(sect->segname, segmentName) == 0) && (strcmp(sect->sectname, sectionName) == 0) ) {
+ *start = (uintptr_t*)(sect->addr + fSlide);
+ *length = sect->size;
+ return true;
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ *start = NULL;
+ *length = 0;
+ return false;
+}
+
+void ImageLoaderMachO::getUnwindInfo(dyld_unwind_sections* info)
+{
+ info->mh = this->machHeader();
+ info->dwarf_section = 0;
+ info->dwarf_section_length = 0;
+ info->compact_unwind_section = 0;
+ info->compact_unwind_section_length = 0;
+ if ( fEHFrameSectionOffset != 0 ) {
+ const macho_section* sect = (macho_section*)&fMachOData[fEHFrameSectionOffset];
+ info->dwarf_section = (void*)(sect->addr + fSlide);
+ info->dwarf_section_length = sect->size;
+ }
+ if ( fUnwindInfoSectionOffset != 0 ) {
+ const macho_section* sect = (macho_section*)&fMachOData[fUnwindInfoSectionOffset];
+ info->compact_unwind_section = (void*)(sect->addr + fSlide);
+ info->compact_unwind_section_length = sect->size;
+ }
+}
+
+
+bool ImageLoaderMachO::findSection(const void* imageInterior, const char** segmentName, const char** sectionName, size_t* sectionOffset)
+{
+ 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 uintptr_t unslidInteriorAddress = (uintptr_t)imageInterior - this->getSlide();
+ 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;
+ if ( (unslidInteriorAddress >= seg->vmaddr) && (unslidInteriorAddress < (seg->vmaddr+seg->vmsize)) ) {
+ 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) {
+ if ((sect->addr <= unslidInteriorAddress) && (unslidInteriorAddress < (sect->addr+sect->size))) {
+ if ( segmentName != NULL )
+ *segmentName = sect->segname;
+ if ( sectionName != NULL )
+ *sectionName = sect->sectname;
+ if ( sectionOffset != NULL )
+ *sectionOffset = unslidInteriorAddress - sect->addr;
+ return true;
+ }
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ return false;
+}
+
+
+void __attribute__((noreturn)) ImageLoaderMachO::throwSymbolNotFound(const char* symbol, const char* referencedFrom, const char* expectedIn)
+{
+ dyld::throwf("Symbol not found: %s\n Referenced from: %s\n Expected in: %s\n", symbol, referencedFrom, expectedIn);
+}
+
+const mach_header* ImageLoaderMachO::machHeader() const
+{
+ return (mach_header*)fMachOData;
+}
+
+uintptr_t ImageLoaderMachO::getSlide() const
+{
+ return fSlide;
+}
+
+// hmm. maybe this should be up in ImageLoader??
+const void* ImageLoaderMachO::getEnd() const
+{
+ uintptr_t lastAddress = 0;
+ for(unsigned int i=0; i < fSegmentsCount; ++i) {
+ uintptr_t segEnd = segActualEndAddress(i);
+ if ( strcmp(segName(i), "__UNIXSTACK") != 0 ) {
+ if ( segEnd > lastAddress )
+ lastAddress = segEnd;
+ }
+ }
+ return (const void*)lastAddress;
+}
+
+
+uintptr_t ImageLoaderMachO::bindLocation(const LinkContext& context, uintptr_t location, uintptr_t value,
+ const ImageLoader* targetImage, uint8_t type, const char* symbolName,
+ intptr_t addend, const char* msg)
+{
+ // log
+ if ( context.verboseBind ) {
+ if ( addend != 0 )
+ dyld::log("dyld: %sbind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX + %ld\n",
+ msg, this->getShortName(), (uintptr_t)location,
+ ((targetImage != NULL) ? targetImage->getShortName() : "<weak_import-missing>"),
+ symbolName, (uintptr_t)location, value, addend);
+ else
+ dyld::log("dyld: %sbind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX\n",
+ msg, this->getShortName(), (uintptr_t)location,
+ ((targetImage != NULL) ? targetImage->getShortName() : "<weak>import-missing>"),
+ symbolName, (uintptr_t)location, value);
+ }
+
+ // do actual update
+ uintptr_t* locationToFix = (uintptr_t*)location;
+ uint32_t* loc32;
+ uintptr_t newValue = value+addend;
+ uint32_t value32;
+ switch (type) {
+ case BIND_TYPE_POINTER:
+ // test first so we don't needless dirty pages
+ if ( *locationToFix != newValue )
+ *locationToFix = newValue;
+ break;
+ case BIND_TYPE_TEXT_ABSOLUTE32:
+ loc32 = (uint32_t*)locationToFix;
+ value32 = (uint32_t)newValue;
+ if ( *loc32 != value32 )
+ *loc32 = value32;
+ break;
+ case BIND_TYPE_TEXT_PCREL32:
+ loc32 = (uint32_t*)locationToFix;
+ value32 = (uint32_t)newValue - (((uintptr_t)locationToFix) + 4);
+ if ( *loc32 != value32 )
+ *loc32 = value32;
+ break;
+ default:
+ dyld::throwf("bad bind type %d", type);
+ }
+
+ // update statistics
+ ++fgTotalBindFixups;
+
+ return newValue;
+}
+
+
+
+
+
+#if SUPPORT_OLD_CRT_INITIALIZATION
+// first 16 bytes of "start" in crt1.o
+#if __ppc__
+ static uint32_t sStandardEntryPointInstructions[4] = { 0x7c3a0b78, 0x3821fffc, 0x54210034, 0x38000000 };
+#elif __i386__
+ static uint8_t sStandardEntryPointInstructions[16] = { 0x6a, 0x00, 0x89, 0xe5, 0x83, 0xe4, 0xf0, 0x83, 0xec, 0x10, 0x8b, 0x5d, 0x04, 0x89, 0x5c, 0x24 };
+#endif
+#endif
+
+struct DATAdyld {
+ void* dyldLazyBinder; // filled in at launch by dyld to point into dyld to &stub_binding_helper_interface
+ void* dyldFuncLookup; // filled in at launch by dyld to point into dyld to &_dyld_func_lookup
+ // the following only exist in main executables built for 10.5 or later
+ ProgramVars vars;
+};
+
+// These are defined in dyldStartup.s
+extern "C" void stub_binding_helper();
+extern "C" bool dyld_func_lookup(const char* name, uintptr_t* address);
+
+
+void ImageLoaderMachO::setupLazyPointerHandler(const LinkContext& context)
+{
+ 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;
+ // set up __dyld section
+ // optimizations:
+ // 1) do nothing if image is in dyld shared cache and dyld loaded at same address as when cache built
+ // 2) first read __dyld value, if already correct don't write, this prevents dirtying a page
+ if ( !fInSharedCache || !context.dyldLoadedAtSameAddressNeededBySharedCache ) {
+ 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 ( strcmp(seg->segname, "__DATA") == 0 ) {
+ 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) {
+ if ( strcmp(sect->sectname, "__dyld" ) == 0 ) {
+ struct DATAdyld* dd = (struct DATAdyld*)(sect->addr + fSlide);
+ if ( sect->size > offsetof(DATAdyld, dyldLazyBinder) ) {
+ if ( dd->dyldLazyBinder != (void*)&stub_binding_helper )
+ dd->dyldLazyBinder = (void*)&stub_binding_helper;
+ }
+ if ( sect->size > offsetof(DATAdyld, dyldFuncLookup) ) {
+ if ( dd->dyldFuncLookup != (void*)&dyld_func_lookup )
+ dd->dyldFuncLookup = (void*)&dyld_func_lookup;
+ }
+ if ( mh->filetype == MH_EXECUTE ) {
+ // there are two ways to get the program variables
+ if ( (sect->size > offsetof(DATAdyld, vars)) && (dd->vars.mh == mh) ) {
+ // some really old binaries have space for vars, but it is zero filled
+ // main executable has 10.5 style __dyld section that has program variable pointers
+ context.setNewProgramVars(dd->vars);
+ }
+ else {
+ // main executable is pre-10.5 and requires the symbols names to be looked up
+ this->lookupProgramVars(context);
+ #if SUPPORT_OLD_CRT_INITIALIZATION
+ // If the first 16 bytes of the entry point's instructions do not
+ // match what crt1.o supplies, then the program has a custom entry point.
+ // This means it might be doing something that needs to be executed before
+ // initializers are run.
+ if ( memcmp(this->getMain(), sStandardEntryPointInstructions, 16) != 0 ) {
+ if ( context.verboseInit )
+ dyld::log("dyld: program uses non-standard entry point so delaying running of initializers\n");
+ context.setRunInitialzersOldWay();
+ }
+ #endif
+ }
+ }
+ }
+ else if ( (strcmp(sect->sectname, "__program_vars" ) == 0) && (mh->filetype == MH_EXECUTE) ) {
+ // this is a Mac OS X 10.6 or later main executable
+ struct ProgramVars* pv = (struct ProgramVars*)(sect->addr + fSlide);
+ context.setNewProgramVars(*pv);
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+}
+
+
+void ImageLoaderMachO::lookupProgramVars(const LinkContext& context) const
+{
+ ProgramVars vars = context.programVars;
+ const ImageLoader::Symbol* sym;
+
+ // get mach header directly
+ vars.mh = (macho_header*)fMachOData;
+
+ // lookup _NXArgc
+ sym = this->findExportedSymbol("_NXArgc", false, NULL);
+ if ( sym != NULL )
+ vars.NXArgcPtr = (int*)this->getExportedSymbolAddress(sym, context, this);
+
+ // lookup _NXArgv
+ sym = this->findExportedSymbol("_NXArgv", false, NULL);
+ if ( sym != NULL )
+ vars.NXArgvPtr = (const char***)this->getExportedSymbolAddress(sym, context, this);
+
+ // lookup _environ
+ sym = this->findExportedSymbol("_environ", false, NULL);
+ if ( sym != NULL )
+ vars.environPtr = (const char***)this->getExportedSymbolAddress(sym, context, this);
+
+ // lookup __progname
+ sym = this->findExportedSymbol("___progname", false, NULL);
+ if ( sym != NULL )
+ vars.__prognamePtr = (const char**)this->getExportedSymbolAddress(sym, context, this);
+
+ context.setNewProgramVars(vars);
+}
+
+
+bool ImageLoaderMachO::usablePrebinding(const LinkContext& context) const
+{
+ // if prebound and loaded at prebound address, and all libraries are same as when this was prebound, then no need to bind
+ if ( (this->isPrebindable() || fInSharedCache)
+ && (this->getSlide() == 0)
+ && this->usesTwoLevelNameSpace()
+ && this->allDependentLibrariesAsWhenPreBound() ) {
+ // allow environment variables to disable prebinding
+ if ( context.bindFlat )
+ return false;
+ switch ( context.prebindUsage ) {
+ case kUseAllPrebinding:
+ return true;
+ case kUseSplitSegPrebinding:
+ return this->fIsSplitSeg;
+ case kUseAllButAppPredbinding:
+ return (this != context.mainExecutable);
+ case kUseNoPrebinding:
+ return false;
+ }
+ }
+ return false;
+}
+
+
+void ImageLoaderMachO::doImageInit(const LinkContext& context)
+{
+ if ( fHasDashInit ) {
+ 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_ROUTINES_COMMAND:
+ Initializer func = (Initializer)(((struct macho_routines_command*)cmd)->init_address + fSlide);
+ if ( context.verboseInit )
+ dyld::log("dyld: calling -init function 0x%p in %s\n", func, this->getPath());
+ func(context.argc, context.argv, context.envp, context.apple, &context.programVars);
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+}
+
+void ImageLoaderMachO::doModInitFunctions(const LinkContext& context)
+{
+ if ( fHasInitializers ) {
+ 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;
+ 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_MOD_INIT_FUNC_POINTERS ) {
+ Initializer* inits = (Initializer*)(sect->addr + fSlide);
+ const uint32_t count = sect->size / sizeof(uintptr_t);
+ for (uint32_t i=0; i < count; ++i) {
+ Initializer func = inits[i];
+ if ( context.verboseInit )
+ dyld::log("dyld: calling initializer function %p in %s\n", func, this->getPath());
+ func(context.argc, context.argv, context.envp, context.apple, &context.programVars);
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+ }
+}
+
+
+
+
+
+
+void ImageLoaderMachO::doGetDOFSections(const LinkContext& context, std::vector<ImageLoader::DOFInfo>& dofs)
+{
+ if ( fHasDOFSections ) {
+ // walk load commands (mapped in at start of __TEXT segment)
+ 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) {
+ if ( (sect->flags & SECTION_TYPE) == S_DTRACE_DOF ) {
+ ImageLoader::DOFInfo info;
+ info.dof = (void*)(sect->addr + fSlide);
+ info.imageHeader = this->machHeader();
+ info.imageShortName = this->getShortName();
+ dofs.push_back(info);
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+}
+
+
+void ImageLoaderMachO::doInitialization(const LinkContext& context)
+{
+ // mach-o has -init and static initializers
+ doImageInit(context);
+ doModInitFunctions(context);
+}
+
+bool ImageLoaderMachO::needsInitialization()
+{
+ return ( fHasDashInit || fHasInitializers );
+}
+
+
+bool ImageLoaderMachO::needsTermination()
+{
+ return fHasTerminators;
+}
+
+
+void ImageLoaderMachO::doTermination(const LinkContext& context)
+{
+ if ( fHasTerminators ) {
+ 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;
+ 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_MOD_TERM_FUNC_POINTERS ) {
+ Terminator* terms = (Terminator*)(sect->addr + fSlide);
+ const uint32_t count = sect->size / sizeof(uintptr_t);
+ for (uint32_t i=count; i > 0; --i) {
+ Terminator func = terms[i-1];
+ if ( context.verboseInit )
+ dyld::log("dyld: calling termination function %p in %s\n", func, this->getPath());
+ func();
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+}
+
+
+void ImageLoaderMachO::printStatistics(unsigned int imageCount)
+{
+ ImageLoader::printStatistics(imageCount);
+ dyld::log("total symbol trie searches: %d\n", fgSymbolTrieSearchs);
+ dyld::log("total symbol table binary searches: %d\n", fgSymbolTableBinarySearchs);
+ dyld::log("total images defining/using weak symbols: %u/%u\n", fgImagesHasWeakDefinitions, fgImagesRequiringCoalescing);
+}
+
+
+intptr_t ImageLoaderMachO::assignSegmentAddresses(const LinkContext& context)
+{
+ // preflight and calculate slide if needed
+ const bool inPIE = (fgNextPIEDylibAddress != 0);
+ intptr_t slide = 0;
+ if ( this->segmentsCanSlide() && this->segmentsMustSlideTogether() ) {
+ bool needsToSlide = false;
+ bool imageHasPreferredLoadAddress = segHasPreferredLoadAddress(0);
+ uintptr_t lowAddr = (unsigned long)(-1);
+ uintptr_t highAddr = 0;
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ const uintptr_t segLow = segPreferredLoadAddress(i);
+ const uintptr_t segHigh = (segLow + segSize(i) + 4095) & -4096;
+ if ( segLow < lowAddr )
+ lowAddr = segLow;
+ if ( segHigh > highAddr )
+ highAddr = segHigh;
+
+ if ( needsToSlide || !imageHasPreferredLoadAddress || inPIE || !reserveAddressRange(segPreferredLoadAddress(i), segSize(i)) )
+ needsToSlide = true;
+ }
+ if ( needsToSlide ) {
+ // find a chunk of address space to hold all segments
+ uintptr_t addr = reserveAnAddressRange(highAddr-lowAddr, context);
+ slide = addr - lowAddr;
+ }
+ }
+ else if ( ! this->segmentsCanSlide() ) {
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ if ( strcmp(segName(i), "__PAGEZERO") == 0 )
+ continue;
+ if ( !reserveAddressRange(segPreferredLoadAddress(i), segSize(i)) )
+ throw "can't map";
+ }
+ }
+ else {
+ throw "mach-o does not support independently sliding segments";
+ }
+ return slide;
+}
+
+
+uintptr_t ImageLoaderMachO::reserveAnAddressRange(size_t length, const ImageLoader::LinkContext& context)
+{
+ vm_address_t addr = 0;
+ vm_size_t size = length;
+ // in PIE programs, load initial dylibs after main executable so they don't have fixed addresses either
+ if ( fgNextPIEDylibAddress != 0 ) {
+ addr = fgNextPIEDylibAddress + (arc4random() & 0x3) * 4096; // add small random padding between dylibs
+ kern_return_t r = vm_allocate(mach_task_self(), &addr, size, VM_FLAGS_FIXED);
+ if ( r == KERN_SUCCESS ) {
+ fgNextPIEDylibAddress = addr + size;
+ return addr;
+ }
+ fgNextPIEDylibAddress = 0;
+ }
+ kern_return_t r = vm_allocate(mach_task_self(), &addr, size, VM_FLAGS_ANYWHERE);
+ if ( r != KERN_SUCCESS )
+ throw "out of address space";
+
+ return addr;
+}
+
+bool ImageLoaderMachO::reserveAddressRange(uintptr_t start, size_t length)
+{
+ vm_address_t addr = start;
+ vm_size_t size = length;
+ kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
+ if ( r != KERN_SUCCESS )
+ return false;
+ return true;
+}
+
+
+
+void ImageLoaderMachO::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
+{
+ // find address range for image
+ intptr_t slide = this->assignSegmentAddresses(context);
+ if ( context.verboseMapping )
+ dyld::log("dyld: Mapping %s\n", this->getPath());
+ // map in all segments
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ vm_offset_t fileOffset = segFileOffset(i) + offsetInFat;
+ vm_size_t size = segFileSize(i);
+ void* requestedLoadAddress = (void*)(segPreferredLoadAddress(i) + slide);
+ int protection = 0;
+ if ( !segUnaccessible(i) ) {
+ if ( segExecutable(i) )
+ protection |= PROT_EXEC;
+ if ( segReadable(i) )
+ protection |= PROT_READ;
+ if ( segWriteable(i) )
+ protection |= PROT_WRITE;
+ }
+ #if __i386__
+ // initially map __IMPORT segments R/W so dyld can update them
+ if ( segIsReadOnlyImport(i) )
+ protection |= PROT_WRITE;
+ #endif
+ // wholly zero-fill segments have nothing to mmap() in
+ if ( size > 0 ) {
+ if ( (fileOffset+size) > fileLen ) {
+ dyld::throwf("truncated mach-o error: segment %s extends to %llu which is past end of file %llu",
+ segName(i), (uint64_t)(fileOffset+size), fileLen);
+ }
+ void* loadAddress = mmap(requestedLoadAddress, size, protection, MAP_FIXED | MAP_PRIVATE, fd, fileOffset);
+ if ( loadAddress == ((void*)(-1)) ) {
+ dyld::throwf("mmap() error %d at address=0x%08lX, size=0x%08lX segment=%s in Segment::map() mapping %s",
+ errno, (uintptr_t)requestedLoadAddress, (uintptr_t)size, segName(i), getPath());
+ }
+ }
+ // update stats
+ ++ImageLoader::fgTotalSegmentsMapped;
+ ImageLoader::fgTotalBytesMapped += size;
+ if ( context.verboseMapping )
+ dyld::log("%18s at 0x%08lX->0x%08lX with permissions %c%c%c\n", segName(i), (uintptr_t)requestedLoadAddress, (uintptr_t)((char*)requestedLoadAddress+size-1),
+ (protection & PROT_READ) ? 'r' : '.', (protection & PROT_WRITE) ? 'w' : '.', (protection & PROT_EXEC) ? 'x' : '.' );
+ }
+ // update slide to reflect load location
+ this->setSlide(slide);
+}
+
+void ImageLoaderMachO::mapSegments(const void* memoryImage, uint64_t imageLen, const LinkContext& context)
+{
+ // find address range for image
+ intptr_t slide = this->assignSegmentAddresses(context);
+ if ( context.verboseMapping )
+ dyld::log("dyld: Mapping memory %p\n", memoryImage);
+ // map in all segments
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ vm_address_t loadAddress = segPreferredLoadAddress(i) + slide;
+ vm_address_t srcAddr = (uintptr_t)memoryImage + segFileOffset(i);
+ vm_size_t size = segFileSize(i);
+ kern_return_t r = vm_copy(mach_task_self(), srcAddr, size, loadAddress);
+ if ( r != KERN_SUCCESS )
+ throw "can't map segment";
+ if ( context.verboseMapping )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n", segName(i), (uintptr_t)loadAddress, (uintptr_t)loadAddress+size-1);
+ }
+ // update slide to reflect load location
+ this->setSlide(slide);
+ // set R/W permissions on all segments at slide location
+ for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
+ segProtect(i, context);
+ }
+}
+
+
+void ImageLoaderMachO::segProtect(unsigned int segIndex, const ImageLoader::LinkContext& context)
+{
+ vm_prot_t protection = 0;
+ if ( !segUnaccessible(segIndex) ) {
+ if ( segExecutable(segIndex) )
+ protection |= PROT_EXEC;
+ if ( segReadable(segIndex) )
+ protection |= PROT_READ;
+ if ( segWriteable(segIndex) )
+ protection |= PROT_WRITE;
+ }
+ vm_address_t addr = segActualLoadAddress(segIndex);
+ vm_size_t size = segSize(segIndex);
+ const bool setCurrentPermissions = false;
+ kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, protection);
+ if ( r != KERN_SUCCESS )
+ throw "can't set vm permissions for mapped segment";
+ if ( context.verboseMapping ) {
+ dyld::log("%18s at 0x%08lX->0x%08lX altered permissions to %c%c%c\n", segName(segIndex), (uintptr_t)addr, (uintptr_t)addr+size-1,
+ (protection & PROT_READ) ? 'r' : '.', (protection & PROT_WRITE) ? 'w' : '.', (protection & PROT_EXEC) ? 'x' : '.' );
+ }
+}
+
+void ImageLoaderMachO::segMakeWritable(unsigned int segIndex, const ImageLoader::LinkContext& context)
+{
+ vm_address_t addr = segActualLoadAddress(segIndex);
+ vm_size_t size = segSize(segIndex);
+ const bool setCurrentPermissions = false;
+ vm_prot_t protection = VM_PROT_WRITE | VM_PROT_READ;
+ if ( segExecutable(segIndex) )
+ protection |= VM_PROT_EXECUTE;
+ kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, protection);
+ if ( r != KERN_SUCCESS )
+ throw "can't set vm permissions for mapped segment";
+ if ( context.verboseMapping ) {
+ dyld::log("%18s at 0x%08lX->0x%08lX altered permissions to %c%c%c\n", segName(segIndex), (uintptr_t)addr, (uintptr_t)addr+size-1,
+ (protection & PROT_READ) ? 'r' : '.', (protection & PROT_WRITE) ? 'w' : '.', (protection & PROT_EXEC) ? 'x' : '.' );
+ }
+}
+
+