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--- dyld/dyld-132.13/src/ImageLoaderMachO.cpp
+++ /dev/null
@@ -1,1717 +0,0 @@
-/* -*- 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' : '.' );
- }
-}
-
-