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+++ dyld/dyld-96.2/src/ImageLoaderMachO.cpp
@@ -0,0 +1,3159 @@
+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2004-2007 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 <sys/types.h>
+#include <sys/fcntl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <mach/shared_memory_server.h>
+#include <mach/mach.h>
+#include <mach/thread_status.h>
+#include <mach-o/loader.h>
+#include <mach-o/reloc.h>
+#include <mach-o/nlist.h>
+#include <sys/sysctl.h>
+#include <libkern/OSAtomic.h>
+#include <libkern/OSCacheControl.h>
+#if __ppc__ || __ppc64__
+ #include <mach-o/ppc/reloc.h>
+#endif
+#if __x86_64__
+ #include <mach-o/x86_64/reloc.h>
+#endif
+
+#ifndef MH_PIE
+ #define MH_PIE 0x200000
+#endif
+
+#ifndef S_DTRACE_DOF
+ #define S_DTRACE_DOF 0xF
+#endif
+
+#ifndef S_ATTR_SELF_MODIFYING_CODE
+ #define S_ATTR_SELF_MODIFYING_CODE 0x04000000
+#endif
+
+#include "ImageLoaderMachO.h"
+#include "mach-o/dyld_images.h"
+
+// optimize strcmp for ppc
+#if __ppc__
+ #include <ppc_intrinsics.h>
+#else
+ #define astrcmp(a,b) strcmp(a,b)
+#endif
+
+// in libc.a
+extern "C" void _spin_lock(uint32_t*);
+extern "C" void _spin_unlock(uint32_t*);
+
+
+// relocation_info.r_length field has value 3 for 64-bit executables and value 2 for 32-bit executables
+#if __LP64__
+ #define RELOC_SIZE 3
+ #define LC_SEGMENT_COMMAND LC_SEGMENT_64
+ #define LC_ROUTINES_COMMAND LC_ROUTINES_64
+ struct macho_header : public mach_header_64 {};
+ struct macho_segment_command : public segment_command_64 {};
+ struct macho_section : public section_64 {};
+ struct macho_nlist : public nlist_64 {};
+ struct macho_routines_command : public routines_command_64 {};
+#else
+ #define RELOC_SIZE 2
+ #define LC_SEGMENT_COMMAND LC_SEGMENT
+ #define LC_ROUTINES_COMMAND LC_ROUTINES
+ struct macho_header : public mach_header {};
+ struct macho_segment_command : public segment_command {};
+ struct macho_section : public section {};
+ struct macho_nlist : public nlist {};
+ struct macho_routines_command : public routines_command {};
+#endif
+
+#if __x86_64__
+ #define POINTER_RELOC X86_64_RELOC_UNSIGNED
+#else
+ #define POINTER_RELOC GENERIC_RELOC_VANILLA
+#endif
+
+uint32_t ImageLoaderMachO::fgHintedBinaryTreeSearchs = 0;
+uint32_t ImageLoaderMachO::fgUnhintedBinaryTreeSearchs = 0;
+uint32_t ImageLoaderMachO::fgCountOfImagesWithWeakExports = 0;
+
+#if __i386__
+uint32_t ImageLoaderMachO::fgReadOnlyImportSpinLock = 0;
+#endif
+
+//#define LINKEDIT_USAGE_DEBUG 1
+
+#if LINKEDIT_USAGE_DEBUG
+ #include <set>
+ static std::set<uintptr_t> sLinkEditPageBuckets;
+
+ namespace dyld {
+ extern ImageLoader* findImageContainingAddress(const void* addr);
+ };
+
+ static void noteAccessedLinkEditAddress(const void* addr)
+ {
+ uintptr_t page = ((uintptr_t)addr) & (-4096);
+ if ( sLinkEditPageBuckets.count(page) == 0 ) {
+ ImageLoader* inImage = dyld::findImageContainingAddress(addr);
+ dyld::log("dyld: accessing page 0x%016lX in __LINKEDIT of %s\n", page, inImage != NULL ? inImage->getPath() : "unknown" );
+ }
+ sLinkEditPageBuckets.insert(page);
+ }
+#endif
+
+// only way to share initialization in C++
+void ImageLoaderMachO::init()
+{
+ fMachOData = NULL;
+ fLinkEditBase = NULL;
+ fSymbolTable = NULL;
+ fStrings = NULL;
+ fDynamicInfo = NULL;
+ fSlide = 0;
+ fTwoLevelHints = NULL;
+ fDylibID = NULL;
+#if TEXT_RELOC_SUPPORT
+ fTextSegmentWithFixups = NULL;
+#endif
+#if __i386__
+ fReadOnlyImportSegment = NULL;
+#endif
+ fIsSplitSeg = false;
+ fInSharedCache = false;
+#if __ppc64__
+ f4GBWritable = false;
+#endif
+ fHasSubLibraries= false;
+ fHasSubUmbrella = false;
+ fInUmbrella = false;
+ fHasDOFSections = false;
+ fHasDashInit = false;
+ fHasInitializers= false;
+ fHasTerminators = false;
+#if IMAGE_NOTIFY_SUPPORT
+ fHasImageNotifySection = false;
+#endif
+}
+
+// create image for main executable
+ImageLoaderMachO::ImageLoaderMachO(const struct mach_header* mh, uintptr_t slide, const char* path, const LinkContext& context)
+ : ImageLoader(path)
+{
+ // clean slate
+ this->init();
+
+ // temporary use this buffer until TEXT is mapped in
+ fMachOData = (const uint8_t*)mh;
+
+ // create segments
+ this->instantiateSegments((const uint8_t*)mh);
+
+ // set slide for PIE programs
+ this->setSlide(slide);
+
+ // get pointers to interesting things
+ this->parseLoadCmds();
+
+ // update segments to reference load commands in mapped in __TEXT segment
+ this->adjustSegments();
+
+#if __i386__
+ // kernel may have mapped in __IMPORT segment read-only, we need it read/write to do binding
+ if ( fReadOnlyImportSegment != NULL )
+ fReadOnlyImportSegment->tempWritable(context, this);
+#endif
+
+ // for PIE record end of program, to know where to start loading dylibs
+ if ( mh->flags & MH_PIE )
+ Segment::fgNextPIEDylibAddress = (uintptr_t)this->getEnd();
+
+ // notify state change
+ this->setMapped(context);
+
+ if ( context.verboseMapping ) {
+ dyld::log("dyld: Main executable mapped %s\n", this->getPath());
+ for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
+ Segment* seg = *it;
+ if ( (strcmp(seg->getName(), "__PAGEZERO") == 0) || (strcmp(seg->getName(), "__UNIXSTACK") == 0) )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n", seg->getName(), seg->getPreferredLoadAddress(), seg->getPreferredLoadAddress()+seg->getSize());
+ else
+ dyld::log("%18s at 0x%08lX->0x%08lX\n", seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getSize());
+ }
+ }
+}
+
+
+// create image by copying an in-memory mach-o file
+ImageLoaderMachO::ImageLoaderMachO(const char* moduleName, const struct mach_header* mh, uint64_t len, const LinkContext& context)
+ : ImageLoader(moduleName)
+{
+ // clean slate
+ this->init();
+
+ // temporary use this buffer until TEXT is mapped in
+ fMachOData = (const uint8_t*)mh;
+
+ // create segments
+ this->instantiateSegments((const uint8_t*)mh);
+
+ // map segments
+ if ( mh->filetype == MH_EXECUTE ) {
+ throw "can't load another MH_EXECUTE";
+ }
+ else {
+ ImageLoader::mapSegments((const void*)mh, len, context);
+ }
+
+ // for compatibility, never unload dylibs loaded from memory
+ this->setNeverUnload();
+
+ // get pointers to interesting things
+ this->parseLoadCmds();
+
+ // update segments to reference load commands in mapped in __TEXT segment
+ this->adjustSegments();
+
+ // bundle loads need path copied
+ if ( moduleName != NULL )
+ this->setPath(moduleName);
+
+ // notify state change
+ this->setMapped(context);
+
+}
+
+// create image by using cached mach-o file
+ImageLoaderMachO::ImageLoaderMachO(const struct mach_header* mh, const char* path, const struct stat& info, const LinkContext& context)
+ : ImageLoader(path, 0, info)
+{
+ // clean slate
+ this->init();
+
+ // already mapped to mh address
+ fMachOData = (const uint8_t*)mh;
+
+ // usually a split seg
+ fIsSplitSeg = ((mh->flags & MH_SPLIT_SEGS) != 0);
+
+ // remember this is from shared cache and cannot be unloaded
+ fInSharedCache = true;
+ this->setNeverUnload();
+
+ // create segments
+ this->instantiateSegments((const uint8_t*)mh);
+
+ // segments already mapped in cache
+ if ( context.verboseMapping ) {
+ dyld::log("dyld: Using shared cached for %s\n", path);
+ for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
+ Segment* seg = *it;
+ dyld::log("%18s at 0x%08lX->0x%08lX\n", seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getSize());
+ }
+ }
+
+ // get pointers to interesting things
+ this->parseLoadCmds();
+
+ // note: path is mapped into cache so no need for ImageLoader to make a copy
+
+ // notify state change
+ this->setMapped(context);
+}
+
+
+// create image by mapping in a mach-o file
+ImageLoaderMachO::ImageLoaderMachO(const char* path, int fd, const uint8_t firstPage[4096], uint64_t offsetInFat,
+ uint64_t lenInFat, const struct stat& info, const LinkContext& context)
+ : ImageLoader(path, offsetInFat, info)
+{
+ // clean slate
+ this->init();
+
+ // read 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);
+ }
+
+ // temporary use this buffer until TEXT is mapped in
+ fMachOData = fileData;
+
+ // the meaning of many fields changes in split seg mach-o files
+ fIsSplitSeg = ((((macho_header*)fileData)->flags & MH_SPLIT_SEGS) != 0) && (((macho_header*)fileData)->filetype == MH_DYLIB);
+
+ // create segments
+ this->instantiateSegments(fileData);
+
+ // map segments, except for main executable which is already mapped in by kernel
+ if ( ((macho_header*)fileData)->filetype != MH_EXECUTE )
+ this->mapSegments(fd, offsetInFat, lenInFat, info.st_size, context);
+
+ // get pointers to interesting things
+ this->parseLoadCmds();
+
+ // update segments to reference load commands in mapped in __TEXT segment
+ this->adjustSegments();
+
+ // notify state change
+ this->setMapped(context);
+
+ // if path happens to be same as in LC_DYLIB_ID load command use that, otherwise malloc a copy of the path
+ const char* installName = getInstallPath();
+ if ( (installName != NULL) && (strcmp(installName, path) == 0) && (path[0] == '/') )
+ this->setPathUnowned(installName);
+ if ( path[0] != '/' ) {
+ // rdar://problem/5135363 turn relative paths into absolute paths so gdb, Symbolication can later find them
+ char realPath[MAXPATHLEN];
+ if ( realpath(path, realPath) != NULL )
+ this->setPath(realPath);
+ else
+ this->setPath(path);
+ }
+ else
+ this->setPath(path);
+
+ // tell kernel about pages we are going to need soon
+ if ( ! context.preFetchDisabled )
+ this->preFetch(fd, offsetInFat, context);
+
+}
+
+
+
+ImageLoaderMachO::~ImageLoaderMachO()
+{
+ // keep count of images with weak exports
+ if ( this->hasCoalescedExports() )
+ --fgCountOfImagesWithWeakExports;
+
+ // keep count of images used in shared cache
+ if ( fInSharedCache )
+ --fgImagesUsedFromSharedCache;
+
+ // usually unmap image when done
+ if ( ! this->leaveMapped() && (this->getState() >= dyld_image_state_mapped) ) {
+ // first segment has load commands, so unmap last
+ Segment* firstSeg = *(this->beginSegments());
+ for(ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
+ Segment* seg = *it;
+ if ( seg != firstSeg )
+ seg->unmap(this);
+ }
+ firstSeg->unmap(this);
+ }
+ // free segment objects
+ free(fSegmentsArray);
+}
+
+
+
+void ImageLoaderMachO::instantiateSegments(const uint8_t* fileData)
+{
+ const uint32_t cmd_count = ((macho_header*)fileData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fileData[sizeof(macho_header)];
+
+ // count LC_SEGMENT cmd and reserve that many segment slots
+ uint32_t segCount = 0;
+ const struct load_command* cmd = cmds;
+ for (unsigned long i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
+ // ignore zero-sized segments
+ if ( ((struct macho_segment_command*)cmd)->vmsize != 0 )
+ ++segCount;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ // fSegmentsArrayCount is only 8-bits
+ if ( segCount > 255 )
+ dyld::throwf("more than 255 segments in %s", this->getPath());
+
+ // allocate array of segment objects in one call to malloc()
+ //fSegmentsArray = static_cast<SegmentMachO*>(operator new[](segCount*sizeof(SegmentMachO)));
+ fSegmentsArray = static_cast<SegmentMachO*>(malloc(segCount*sizeof(SegmentMachO)));
+ fSegmentsArrayCount = segCount;
+
+ // construct Segment object for each LC_SEGMENT cmd using "placment new"
+ uint32_t segIndex = 0;
+ cmd = cmds;
+ for (unsigned long i = 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 )
+ new (&fSegmentsArray[segIndex++]) SegmentMachO(segCmd);
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+
+
+void ImageLoaderMachO::adjustSegments()
+{
+ // tell each segment where is load command is finally mapped
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ uint32_t segIndex = 0;
+ const struct load_command* cmd = cmds;
+ for (unsigned long i = 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 ) {
+ fSegmentsArray[segIndex].adjust(segCmd);
+ ++segIndex;
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+
+void ImageLoaderMachO::preFetch(int fd, uint64_t offsetInFat, const LinkContext& context)
+{
+ // always prefetch a subrange of __LINKEDIT pages
+ uintptr_t symbolTableOffset = (uintptr_t)fSymbolTable - (uintptr_t)fLinkEditBase;
+ uintptr_t stringTableOffset = (uintptr_t)fStrings - (uintptr_t)fLinkEditBase;
+ uintptr_t start;
+ // if image did not load at preferred address
+ if ( fSegmentsArray[0].getPreferredLoadAddress() != (uintptr_t)fMachOData ) {
+ // local relocations will be processed, so start pre-fetch at local symbols
+ start = offsetInFat + fDynamicInfo->locreloff;
+ }
+ else {
+ // otherwise start pre-fetch at global symbols section of symbol table
+ start = offsetInFat + symbolTableOffset + fDynamicInfo->iextdefsym * sizeof(macho_nlist);
+ }
+ // prefetch ends at end of last undefined string in string pool
+ uintptr_t end = offsetInFat + stringTableOffset;
+ if ( fDynamicInfo->nundefsym != 0 )
+ end += fSymbolTable[fDynamicInfo->iundefsym+fDynamicInfo->nundefsym-1].n_un.n_strx;
+ else if ( fDynamicInfo->nextdefsym != 0 )
+ end += fSymbolTable[fDynamicInfo->iextdefsym+fDynamicInfo->nextdefsym-1].n_un.n_strx;
+
+ radvisory advice;
+ advice.ra_offset = start & (-4096); // page align
+ advice.ra_count = (end-advice.ra_offset+4095) & (-4096);
+ fgTotalBytesPreFetched += advice.ra_count;
+ fcntl(fd, F_RDADVISE, &advice);
+ if ( context.verboseMapping ) {
+ dyld::log("%18s prefetching 0x%0llX -> 0x%0llX\n",
+ "__LINKEDIT", advice.ra_offset+(uintptr_t)fLinkEditBase-offsetInFat, advice.ra_offset+advice.ra_count+(uintptr_t)fLinkEditBase-offsetInFat);
+ }
+
+ // prefetch __DATA/__OBJC pages during launch, but not for dynamically loaded code
+ if ( context.linkingMainExecutable ) {
+ for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
+ Segment* seg = *it;
+ if ( seg->writeable() && (seg->getFileSize() > 0) ) {
+ // prefetch writable segment that have mmap'ed regions
+ advice.ra_offset = offsetInFat + seg->getFileOffset();
+ advice.ra_count = seg->getFileSize();
+ // limit prefetch to 1MB (256 pages)
+ if ( advice.ra_count > 1024*1024 )
+ advice.ra_count = 1024*1024;
+ fgTotalBytesPreFetched += advice.ra_count;
+ fcntl(fd, F_RDADVISE, &advice);
+ if ( context.verboseMapping ) {
+ dyld::log("%18s prefetching 0x%0lX -> 0x%0lX\n",
+ seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+advice.ra_count-1);
+ }
+ }
+ }
+ }
+}
+
+bool ImageLoaderMachO::segmentsMustSlideTogether() const
+{
+ return true;
+}
+
+bool ImageLoaderMachO::segmentsCanSlide() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->filetype == MH_DYLIB) || (mh->filetype == MH_BUNDLE) );
+}
+
+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::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::needsCoalescing() const
+{
+ const macho_header* mh = (macho_header*)fMachOData;
+ return ( (mh->flags & MH_BINDS_TO_WEAK) != 0 );
+}
+
+
+
+
+
+
+// hack until kernel headers and glue are in system
+struct _shared_region_mapping_np {
+ mach_vm_address_t address;
+ mach_vm_size_t size;
+ mach_vm_offset_t file_offset;
+ vm_prot_t max_prot; /* read/write/execute/COW/ZF */
+ vm_prot_t init_prot; /* read/write/execute/COW/ZF */
+};
+struct _shared_region_range_np {
+ mach_vm_address_t address;
+ mach_vm_size_t size;
+};
+
+#if SPLIT_SEG_SHARED_REGION_SUPPORT
+// Called by dyld.
+// Requests the kernel to map a number of regions from the fd into the
+// shared sections address range (0x90000000-0xAFFFFFFF).
+// If shared_region_make_private_np() has not been called by this process,
+// the file mapped in is seen in the address space of all processes that
+// participate in using the shared region.
+// If shared_region_make_private_np() _has_ been called by this process,
+// the file mapped in is only seen by this process.
+// If the slide parameter is not NULL and then regions cannot be mapped
+// as requested, the kernel will try to map the file in at a different
+// address in the shared region and return the distance slid.
+// If the mapping requesting cannot be fulfilled, returns non-zero.
+static int
+_shared_region_map_file_np(
+ int fd, // file descriptor to map into shared region
+ unsigned int regionCount, // number of entres in array of regions
+ const _shared_region_mapping_np regions[], // the array of regions to map
+ uint64_t* slide) // the amount all regions were slid, NULL means don't attempt to slide
+{
+ //dyld::log("%s(%i, %u, %8p, %8p)\n", __func__, fd, regionCount, regions, slide);
+ //for ( unsigned int i=0; i < regionCount; ++i) {
+ // dyld::log("\taddress=0x%08llX, size=0x%08llX\n", regions[i].address, regions[i].size);
+ //}
+ int r = syscall(299, fd, regionCount, regions, slide);
+// if(0 != r)
+// dyld::log("%s(%i, %u, %8p, %8p) errno=%i (%s)\n", __func__, fd, regionCount, regions, slide, errno, strerror(errno));
+ return r;
+}
+// Called by dyld if shared_region_map_file() fails.
+// Requests the kernel to take this process out of using the shared region.
+// The specified ranges are created as private copies from the shared region for this process.
+static int
+_shared_region_make_private_np(
+ unsigned int rangeCount, // number of entres in array of msrp_range
+ const _shared_region_range_np ranges[]) // the array of shared regions to make private
+{
+ //dyld::log("%s(%u, %8p)\n", __func__, rangeCount, ranges);
+ int r = syscall(300, rangeCount, ranges);
+// if(0 != r)
+// dyld::log("%s(%u, %8p) errno=%i (%s)\n", __func__, rangeCount, ranges, errno, strerror(errno));
+ return r;
+}
+#define KERN_SHREG_PRIVATIZABLE 54
+
+
+static int
+_shared_region_map_file_with_mmap(
+ int fd, // file descriptor to map into shared region
+ unsigned int regionCount, // number of entres in array of regions
+ const _shared_region_mapping_np regions[]) // the array of regions to map
+{
+ // map in each region
+ for(unsigned int i=0; i < regionCount; ++i) {
+ void* mmapAddress = (void*)(uintptr_t)(regions[i].address);
+ size_t size = regions[i].size;
+ if ( (regions[i].init_prot & VM_PROT_ZF) != 0 ) {
+ // do nothing already vm_allocate() which zero fills
+ }
+ else {
+ int protection = 0;
+ if ( regions[i].init_prot & VM_PROT_EXECUTE )
+ protection |= PROT_EXEC;
+ if ( regions[i].init_prot & VM_PROT_READ )
+ protection |= PROT_READ;
+ if ( regions[i].init_prot & VM_PROT_WRITE )
+ protection |= PROT_WRITE;
+ off_t offset = regions[i].file_offset;
+ //dyld::log("mmap(%p, 0x%08lX, block=0x%08X, %s\n", mmapAddress, size, biggestDiff, fPath);
+ mmapAddress = mmap(mmapAddress, size, protection, MAP_FIXED | MAP_PRIVATE, fd, offset);
+ if ( mmapAddress == ((void*)(-1)) )
+ throw "mmap error";
+ }
+ }
+
+ return 0;
+}
+
+
+static
+bool
+hasSharedRegionMapFile(void)
+{
+ int mib[CTL_MAXNAME];
+ int value = 0;
+ size_t size;
+
+ mib[0] = CTL_KERN;
+ mib[1] = KERN_SHREG_PRIVATIZABLE;
+ size = sizeof (int);
+ if (sysctl(mib, 2, &value, &size, NULL, 0) != 0) {
+ value = 0;
+ }
+
+ return 0 != value;
+}
+
+#endif // SPLIT_SEG_SHARED_REGION_SUPPORT
+
+
+#if SPLIT_SEG_DYLIB_SUPPORT
+unsigned int
+ImageLoaderMachO::getExtraZeroFillEntriesCount()
+{
+ // calculate mapping entries
+ unsigned int extraZeroFillEntries = 0;
+ for(ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
+ Segment* seg = *it;
+ if ( seg->hasTrailingZeroFill() )
+ ++extraZeroFillEntries;
+ }
+
+ return extraZeroFillEntries;
+}
+
+void
+ImageLoaderMachO::initMappingTable(uint64_t offsetInFat,
+ _shared_region_mapping_np *mappingTable)
+{
+ unsigned int segmentCount = fSegmentsArrayCount;
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = &fSegmentsArray[segIndex];
+ _shared_region_mapping_np* entry = &mappingTable[entryIndex];
+ entry->address = seg->getActualLoadAddress(this);
+ entry->size = seg->getFileSize();
+ entry->file_offset = seg->getFileOffset() + offsetInFat;
+ entry->init_prot = VM_PROT_NONE;
+ if ( !seg->unaccessible() ) {
+ if ( seg->executable() )
+ entry->init_prot |= VM_PROT_EXECUTE;
+ if ( seg->readable() )
+ entry->init_prot |= VM_PROT_READ;
+ if ( seg->writeable() )
+ entry->init_prot |= VM_PROT_WRITE | VM_PROT_COW;
+ }
+ entry->max_prot = entry->init_prot;
+ if ( seg->hasTrailingZeroFill() ) {
+ _shared_region_mapping_np* zfentry = &mappingTable[++entryIndex];
+ zfentry->address = entry->address + seg->getFileSize();
+ zfentry->size = seg->getSize() - seg->getFileSize();
+ zfentry->file_offset = 0;
+ zfentry->init_prot = entry->init_prot | VM_PROT_COW | VM_PROT_ZF;
+ zfentry->max_prot = zfentry->init_prot;
+ }
+ }
+}
+
+int
+ImageLoaderMachO::sharedRegionMapFilePrivateOutside(int fd,
+ uint64_t offsetInFat,
+ uint64_t lenInFat,
+ uint64_t fileLen,
+ const LinkContext& context)
+{
+ static uintptr_t sNextAltLoadAddress
+ #if __ppc_
+ = 0xC0000000;
+ #else
+ = 0;
+ #endif
+
+ const unsigned int segmentCount = fSegmentsArrayCount;
+ const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
+ const unsigned int regionCount = segmentCount+extraZeroFillEntries;
+ _shared_region_mapping_np regions[regionCount];
+ initMappingTable(offsetInFat, regions);
+ int r = -1;
+ // find space somewhere to allocate split seg
+ bool foundRoom = false;
+ vm_size_t biggestDiff = 0;
+ while ( ! foundRoom ) {
+ foundRoom = true;
+ for(unsigned int i=0; i < regionCount; ++i) {
+ vm_address_t addr = sNextAltLoadAddress + regions[i].address - regions[0].address;
+ vm_size_t size = regions[i].size ;
+ r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
+ if ( 0 != r ) {
+ // no room here, deallocate what has succeeded so far
+ for(unsigned int j=0; j < i; ++j) {
+ vm_address_t addr = sNextAltLoadAddress + regions[j].address - regions[0].address;
+ vm_size_t size = regions[j].size ;
+ (void)vm_deallocate(mach_task_self(), addr, size);
+ }
+ sNextAltLoadAddress += 0x00100000; // skip ahead 1MB and try again
+ if ( (sNextAltLoadAddress & 0xF0000000) == 0x90000000 )
+ sNextAltLoadAddress = 0xB0000000;
+ if ( (sNextAltLoadAddress & 0xF0000000) == 0xF0000000 )
+ throw "can't map split seg anywhere";
+ foundRoom = false;
+ break;
+ }
+ vm_size_t high = (regions[i].address + size - regions[0].address) & 0x0FFFFFFF;
+ if ( high > biggestDiff )
+ biggestDiff = high;
+ }
+ }
+
+ // map in each region
+ uintptr_t slide = sNextAltLoadAddress - regions[0].address;
+ this->setSlide(slide);
+ for(unsigned int i=0; i < regionCount; ++i) {
+ if ( ((regions[i].init_prot & VM_PROT_ZF) != 0) || (regions[i].size == 0) ) {
+ // nothing to mmap for zero-fills areas, they are just vm_allocated
+ }
+ else {
+ void* mmapAddress = (void*)(uintptr_t)(regions[i].address + slide);
+ size_t size = regions[i].size;
+ int protection = 0;
+ if ( regions[i].init_prot & VM_PROT_EXECUTE )
+ protection |= PROT_EXEC;
+ if ( regions[i].init_prot & VM_PROT_READ )
+ protection |= PROT_READ;
+ if ( regions[i].init_prot & VM_PROT_WRITE )
+ protection |= PROT_WRITE;
+ off_t offset = regions[i].file_offset;
+ //dyld::log("mmap(%p, 0x%08lX, block=0x%08X, %s\n", mmapAddress, size, biggestDiff, fPath);
+ mmapAddress = mmap(mmapAddress, size, protection, MAP_FIXED | MAP_PRIVATE, fd, offset);
+ if ( mmapAddress == ((void*)(-1)) )
+ throw "mmap error";
+ }
+ }
+ // set so next maps right after this one
+ sNextAltLoadAddress += biggestDiff;
+ sNextAltLoadAddress = (sNextAltLoadAddress + 4095) & (-4096);
+
+ // logging
+ if ( context.verboseMapping ) {
+ dyld::log("dyld: Mapping split-seg outside shared region, slid by 0x%08lX %s\n", this->fSlide, this->getPath());
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = &fSegmentsArray[segIndex];
+ const _shared_region_mapping_np* entry = ®ions[entryIndex];
+ if ( (entry->init_prot & VM_PROT_ZF) == 0 )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getFileSize()-1);
+ if ( entryIndex < (regionCount-1) ) {
+ const _shared_region_mapping_np* nextEntry = ®ions[entryIndex+1];
+ if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
+ uint64_t segOffset = nextEntry->address - entry->address;
+ dyld::log("%18s at 0x%08lX->0x%08lX (zerofill)\n",
+ seg->getName(), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset + nextEntry->size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+
+ return r;
+}
+
+
+void ImageLoaderMachO::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
+{
+ // non-split segment libraries handled by super class
+ if ( !fIsSplitSeg )
+ return ImageLoader::mapSegments(fd, offsetInFat, lenInFat, fileLen, context);
+
+#if SPLIT_SEG_SHARED_REGION_SUPPORT
+ enum SharedRegionState
+ {
+ kSharedRegionStartState = 0,
+ kSharedRegionMapFileState,
+ kSharedRegionMapFilePrivateState,
+ kSharedRegionMapFilePrivateMMapState,
+ kSharedRegionMapFilePrivateOutsideState,
+ };
+ static SharedRegionState sSharedRegionState = kSharedRegionStartState;
+
+ if ( kSharedRegionStartState == sSharedRegionState ) {
+ if ( hasSharedRegionMapFile() ) {
+ if ( context.sharedRegionMode == kUsePrivateSharedRegion ) {
+ sharedRegionMakePrivate(context);
+ sSharedRegionState = kSharedRegionMapFilePrivateState;
+ }
+ else if ( context.sharedRegionMode == kDontUseSharedRegion ) {
+ sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
+ }
+ else if ( context.sharedRegionMode == kSharedRegionIsSharedCache ) {
+ sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
+ }
+ else {
+ sSharedRegionState = kSharedRegionMapFileState;
+ }
+ }
+ else {
+ sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
+ }
+ }
+
+ if ( kSharedRegionMapFileState == sSharedRegionState ) {
+ if ( 0 != sharedRegionMapFile(fd, offsetInFat, lenInFat, fileLen, context) ) {
+ sharedRegionMakePrivate(context);
+ sSharedRegionState = kSharedRegionMapFilePrivateState;
+ }
+ }
+
+ if ( (kSharedRegionMapFilePrivateState == sSharedRegionState) || (kSharedRegionMapFilePrivateMMapState == sSharedRegionState) ) {
+ if ( 0 != sharedRegionMapFilePrivate(fd, offsetInFat, lenInFat, fileLen, context, (kSharedRegionMapFilePrivateMMapState == sSharedRegionState)) ) {
+ sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
+ }
+ }
+
+ if ( kSharedRegionMapFilePrivateOutsideState == sSharedRegionState ) {
+ if ( 0 != sharedRegionMapFilePrivateOutside(fd, offsetInFat, lenInFat, fileLen, context) ) {
+ throw "mapping error";
+ }
+ }
+#else
+ // support old split-seg dylibs by mapping them where ever we find space
+ if ( sharedRegionMapFilePrivateOutside(fd, offsetInFat, lenInFat, fileLen, context) != 0 ) {
+ throw "mapping error";
+ }
+#endif
+}
+#endif // SPLIT_SEG_DYLIB_SUPPORT
+
+
+#if SPLIT_SEG_SHARED_REGION_SUPPORT
+int ImageLoaderMachO::sharedRegionMakePrivate(const LinkContext& context)
+{
+ if ( context.verboseMapping )
+ dyld::log("dyld: making shared regions private\n");
+
+ // shared mapping failed, so make private copy of shared region and try mapping private
+ MappedRegion allRegions[context.imageCount()*8]; // assume average of less that eight segments per image
+ MappedRegion* end = context.getAllMappedRegions(allRegions);
+ _shared_region_range_np splitSegRegions[end-allRegions];
+ _shared_region_range_np* sp = splitSegRegions;
+ for (MappedRegion* p=allRegions; p < end; ++p) {
+ uint8_t highByte = p->address >> 28;
+ if ( (highByte == 9) || (highByte == 0xA) ) {
+ _shared_region_range_np splitRegion;
+ splitRegion.address = p->address;
+ splitRegion.size = p->size;
+ *sp++ = splitRegion;
+ }
+ }
+ int result = _shared_region_make_private_np(sp-splitSegRegions, splitSegRegions);
+ // notify gdb or other lurkers that this process is no longer using the shared region
+ dyld_all_image_infos.processDetachedFromSharedRegion = true;
+ return result;
+}
+
+int
+ImageLoaderMachO::sharedRegionMapFile(int fd,
+ uint64_t offsetInFat,
+ uint64_t lenInFat,
+ uint64_t fileLen,
+ const LinkContext& context)
+{
+ // build table of segments to map
+ const unsigned int segmentCount = fSegmentsArrayCount;
+ const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
+ const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
+ _shared_region_mapping_np mappingTable[mappingTableCount];
+ initMappingTable(offsetInFat, mappingTable);
+// uint64_t slide;
+ uint64_t *slidep = NULL;
+
+ // try to map it in shared
+ int r = _shared_region_map_file_np(fd, mappingTableCount, mappingTable, slidep);
+ if ( 0 == r ) {
+ if(NULL != slidep && 0 != *slidep) {
+ // update with actual load addresses
+ }
+ this->setNeverUnload();
+ if ( context.verboseMapping ) {
+ dyld::log("dyld: Mapping split-seg shared %s\n", this->getPath());
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = &fSegmentsArray[segIndex];
+ const _shared_region_mapping_np* entry = &mappingTable[entryIndex];
+ if ( (entry->init_prot & VM_PROT_ZF) == 0 )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getFileSize()-1);
+ if ( entryIndex < (mappingTableCount-1) ) {
+ const _shared_region_mapping_np* nextEntry = &mappingTable[entryIndex+1];
+ if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
+ uint64_t segOffset = nextEntry->address - entry->address;
+ dyld::log("%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset + nextEntry->size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+ }
+ return r;
+}
+
+
+int
+ImageLoaderMachO::sharedRegionMapFilePrivate(int fd,
+ uint64_t offsetInFat,
+ uint64_t lenInFat,
+ uint64_t fileLen,
+ const LinkContext& context,
+ bool usemmap)
+{
+ const unsigned int segmentCount = fSegmentsArrayCount;
+
+ // build table of segments to map
+ const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
+ const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
+ _shared_region_mapping_np mappingTable[mappingTableCount];
+ initMappingTable(offsetInFat, mappingTable);
+ uint64_t slide = 0;
+
+ // try map it in privately (don't allow sliding if we pre-calculated the load address to pack dylibs)
+ int r;
+ if ( usemmap )
+ r = _shared_region_map_file_with_mmap(fd, mappingTableCount, mappingTable);
+ else
+ r = _shared_region_map_file_np(fd, mappingTableCount, mappingTable, &slide);
+ if ( 0 == r ) {
+ if ( 0 != slide ) {
+ slide = (slide) & (-4096); // round down to page boundary
+ this->setSlide(slide);
+ }
+ this->setNeverUnload();
+ if ( context.verboseMapping ) {
+ if ( slide == 0 )
+ dyld::log("dyld: Mapping split-seg un-shared %s\n", this->getPath());
+ else
+ dyld::log("dyld: Mapping split-seg un-shared slid by 0x%08llX %s\n", slide, this->getPath());
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = &fSegmentsArray[segIndex];
+ const _shared_region_mapping_np* entry = &mappingTable[entryIndex];
+ if ( (entry->init_prot & VM_PROT_ZF) == 0 )
+ dyld::log("%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), seg->getActualLoadAddress(this), seg->getActualLoadAddress(this)+seg->getFileSize()-1);
+ if ( entryIndex < (mappingTableCount-1) ) {
+ const _shared_region_mapping_np* nextEntry = &mappingTable[entryIndex+1];
+ if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
+ uint64_t segOffset = nextEntry->address - entry->address;
+ dyld::log("%18s at 0x%08lX->0x%08lX (zerofill)\n",
+ seg->getName(), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset), (uintptr_t)(seg->getActualLoadAddress(this) + segOffset + nextEntry->size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+ }
+ if ( r != 0 )
+ dyld::throwf("can't rebase split-seg dylib %s because shared_region_map_file_np() returned %d", this->getPath(), r);
+
+ return r;
+}
+
+void
+ImageLoaderMachO::initMappingTable(uint64_t offsetInFat,
+ sf_mapping *mappingTable,
+ uintptr_t baseAddress)
+{
+ unsigned int segmentCount = fSegmentsArrayCount;
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = &fSegmentsArray[segIndex];
+ sf_mapping* entry = &mappingTable[entryIndex];
+ entry->mapping_offset = seg->getPreferredLoadAddress() - baseAddress;
+ entry->size = seg->getFileSize();
+ entry->file_offset = seg->getFileOffset() + offsetInFat;
+ entry->protection = VM_PROT_NONE;
+ if ( !seg->unaccessible() ) {
+ if ( seg->executable() )
+ entry->protection |= VM_PROT_EXECUTE;
+ if ( seg->readable() )
+ entry->protection |= VM_PROT_READ;
+ if ( seg->writeable() )
+ entry->protection |= VM_PROT_WRITE | VM_PROT_COW;
+ }
+
+ entry->cksum = 0;
+ if ( seg->hasTrailingZeroFill() ) {
+ sf_mapping* zfentry = &mappingTable[++entryIndex];
+ zfentry->mapping_offset = entry->mapping_offset + seg->getFileSize();
+ zfentry->size = seg->getSize() - seg->getFileSize();
+ zfentry->file_offset = 0;
+ zfentry->protection = entry->protection | VM_PROT_COW | VM_PROT_ZF;
+ zfentry->cksum = 0;
+ }
+ }
+}
+
+#endif // SPLIT_SEG_SHARED_REGION_SUPPORT
+
+
+
+void ImageLoaderMachO::setSlide(intptr_t slide)
+{
+ fSlide = slide;
+}
+
+void ImageLoaderMachO::parseLoadCmds()
+{
+ // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
+ for (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
+ Segment* seg = *it;
+ // set up pointer to __LINKEDIT segment
+ if ( strcmp(seg->getName(),"__LINKEDIT") == 0 )
+ fLinkEditBase = (uint8_t*)(seg->getActualLoadAddress(this) - seg->getFileOffset());
+#if TEXT_RELOC_SUPPORT
+ // __TEXT segment always starts at beginning of file and contains mach_header and load commands
+ if ( strcmp(seg->getName(),"__TEXT") == 0 ) {
+ if ( ((SegmentMachO*)seg)->hasFixUps() )
+ fTextSegmentWithFixups = (SegmentMachO*)seg;
+ }
+#endif
+#if __i386__
+ if ( seg->readOnlyImportStubs() )
+ fReadOnlyImportSegment = (SegmentMachO*)seg;
+#endif
+ // some segment always starts at beginning of file and contains mach_header and load commands
+ if ( (seg->getFileOffset() == 0) && (seg->getFileSize() != 0) ) {
+ fMachOData = (uint8_t*)(seg->getActualLoadAddress(this));
+ }
+ #if __ppc64__
+ // in 10.5 to support images that span 4GB (including pagezero) switch meaning of r_address
+ if ( ((seg->getPreferredLoadAddress() + seg->getSize() - fSegmentsArray[0].getPreferredLoadAddress()) > 0x100000000)
+ && seg->writeable() )
+ f4GBWritable = true;
+ #endif
+ }
+
+ // keep count of prebound images with weak exports
+ if ( this->hasCoalescedExports() )
+ ++fgCountOfImagesWithWeakExports;
+
+ // keep count of images used in shared cache
+ if ( fInSharedCache )
+ ++fgImagesUsedFromSharedCache;
+
+ // 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_SYMTAB:
+ {
+ const struct symtab_command* symtab = (struct symtab_command*)cmd;
+ fStrings = (const char*)&fLinkEditBase[symtab->stroff];
+ fSymbolTable = (struct macho_nlist*)(&fLinkEditBase[symtab->symoff]);
+ }
+ break;
+ case LC_DYSYMTAB:
+ fDynamicInfo = (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_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+#if IMAGE_NOTIFY_SUPPORT
+ const bool isDataSeg = (strcmp(seg->segname, "__DATA") == 0);
+#endif
+ 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;
+#if IMAGE_NOTIFY_SUPPORT
+ else if ( isDataSeg && (strcmp(sect->sectname, "__image_notify") == 0) )
+ fHasImageNotifySection = true;
+#endif
+ }
+ }
+ break;
+ case LC_TWOLEVEL_HINTS:
+ fTwoLevelHints = (struct twolevel_hints_command*)cmd;
+ break;
+ case LC_ID_DYLIB:
+ {
+ fDylibID = (struct dylib_command*)cmd;
+ }
+ 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);
+ }
+}
+
+
+
+
+const char* ImageLoaderMachO::getInstallPath() const
+{
+ if ( fDylibID != NULL ) {
+ return (char*)fDylibID + fDylibID->dylib.name.offset;
+ }
+ return NULL;
+}
+
+// test if this image is re-exported through parent (the image that loaded this one)
+bool ImageLoaderMachO::isSubframeworkOf(const LinkContext& context, const ImageLoader* parent) const
+{
+ if ( fInUmbrella ) {
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ if (cmd->cmd == LC_SUB_FRAMEWORK) {
+ const struct sub_framework_command* subf = (struct sub_framework_command*)cmd;
+ const char* exportThruName = (char*)cmd + subf->umbrella.offset;
+ // need to match LC_SUB_FRAMEWORK string against the leaf name of the install location of parent...
+ const char* parentInstallPath = parent->getInstallPath();
+ if ( parentInstallPath != NULL ) {
+ const char* lastSlash = strrchr(parentInstallPath, '/');
+ if ( lastSlash != NULL ) {
+ if ( strcmp(&lastSlash[1], exportThruName) == 0 )
+ return true;
+ if ( context.imageSuffix != NULL ) {
+ // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
+ char reexportAndSuffix[strlen(context.imageSuffix)+strlen(exportThruName)+1];
+ strcpy(reexportAndSuffix, exportThruName);
+ strcat(reexportAndSuffix, context.imageSuffix);
+ if ( strcmp(&lastSlash[1], reexportAndSuffix) == 0 )
+ return true;
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+ return false;
+}
+
+// test if child is re-exported
+bool ImageLoaderMachO::hasSubLibrary(const LinkContext& context, const ImageLoader* child) const
+{
+ if ( fHasSubLibraries ) {
+ // need to match LC_SUB_LIBRARY string against the leaf name (without extension) of the install location of child...
+ const char* childInstallPath = child->getInstallPath();
+ if ( childInstallPath != NULL ) {
+ const char* lastSlash = strrchr(childInstallPath, '/');
+ if ( lastSlash != NULL ) {
+ const char* firstDot = strchr(lastSlash, '.');
+ int len;
+ if ( firstDot == NULL )
+ len = strlen(lastSlash);
+ else
+ len = firstDot-lastSlash-1;
+ char childLeafName[len+1];
+ strncpy(childLeafName, &lastSlash[1], len);
+ childLeafName[len] = '\0';
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SUB_LIBRARY:
+ {
+ const struct sub_library_command* lib = (struct sub_library_command*)cmd;
+ const char* aSubLibName = (char*)cmd + lib->sub_library.offset;
+ if ( strcmp(aSubLibName, childLeafName) == 0 )
+ return true;
+ if ( context.imageSuffix != NULL ) {
+ // when DYLD_IMAGE_SUFFIX is used, childLeafName string needs imageSuffix removed from end
+ char aSubLibNameAndSuffix[strlen(context.imageSuffix)+strlen(aSubLibName)+1];
+ strcpy(aSubLibNameAndSuffix, aSubLibName);
+ strcat(aSubLibNameAndSuffix, context.imageSuffix);
+ if ( strcmp(aSubLibNameAndSuffix, childLeafName) == 0 )
+ return true;
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+ }
+ }
+ if ( fHasSubUmbrella ) {
+ // need to match LC_SUB_UMBRELLA string against the leaf name of install location of child...
+ const char* childInstallPath = child->getInstallPath();
+ if ( childInstallPath != NULL ) {
+ const char* lastSlash = strrchr(childInstallPath, '/');
+ if ( lastSlash != NULL ) {
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SUB_UMBRELLA:
+ {
+ const struct sub_umbrella_command* um = (struct sub_umbrella_command*)cmd;
+ const char* aSubUmbrellaName = (char*)cmd + um->sub_umbrella.offset;
+ if ( strcmp(aSubUmbrellaName, &lastSlash[1]) == 0 )
+ return true;
+ if ( context.imageSuffix != NULL ) {
+ // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
+ char umbrellaAndSuffix[strlen(context.imageSuffix)+strlen(aSubUmbrellaName)+1];
+ strcpy(umbrellaAndSuffix, aSubUmbrellaName);
+ strcat(umbrellaAndSuffix, context.imageSuffix);
+ if ( strcmp(umbrellaAndSuffix, &lastSlash[1]) == 0 )
+ return true;
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+ }
+ }
+ return false;
+}
+
+
+
+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 (unsigned long 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);
+ #else
+ #warning need processor specific code
+ #endif
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ return NULL;
+}
+
+
+uint32_t ImageLoaderMachO::doGetDependentLibraryCount()
+{
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ uint32_t count = 0;
+ const struct load_command* cmd = cmds;
+ for (unsigned long i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ case LC_REEXPORT_DYLIB:
+ ++count;
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ return count;
+}
+
+void ImageLoaderMachO::doGetDependentLibraries(DependentLibraryInfo libs[])
+{
+ 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 (unsigned long 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 ( fDylibID != NULL ) {
+ info.minVersion = fDylibID->dylib.compatibility_version;
+ info.maxVersion = fDylibID->dylib.current_version;
+ info.checksum = fDylibID->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 (unsigned long 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 ( issetugid() && (context.mainExecutable == this) ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in setuid 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 ( issetugid() ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in setuid 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] != '/') && issetugid() ) {
+ dyld::warn("LC_RPATH %s in %s being ignored in setuid program because it is a relative path\n", path, this->getPath());
+ break;
+ }
+ 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);
+ }
+}
+
+uintptr_t ImageLoaderMachO::getFirstWritableSegmentAddress()
+{
+ // in split segment libraries r_address is offset from first writable segment
+ for(ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
+ Segment* seg = *it;
+ if ( seg->writeable() )
+ return seg->getActualLoadAddress(this);
+ }
+ throw "no writable segment";
+}
+
+uintptr_t ImageLoaderMachO::getRelocBase()
+{
+ // r_address is either an offset from the first segment address
+ // or from the first writable segment address
+#if __ppc__ || __i386__
+ if ( fIsSplitSeg )
+ return getFirstWritableSegmentAddress();
+ else
+ return fSegmentsArray[0].getActualLoadAddress(this);
+#elif __ppc64__
+ if ( f4GBWritable )
+ return getFirstWritableSegmentAddress();
+ else
+ return fSegmentsArray[0].getActualLoadAddress(this);
+#elif __x86_64__
+ return getFirstWritableSegmentAddress();
+#endif
+}
+
+
+#if __ppc__
+static inline void otherRelocsPPC(uintptr_t* locationToFix, uint8_t relocationType, uint16_t otherHalf, uintptr_t slide)
+{
+ // low 16 bits of 32-bit ppc instructions need fixing
+ struct ppcInstruction { uint16_t opcode; int16_t immediateValue; };
+ ppcInstruction* instruction = (ppcInstruction*)locationToFix;
+ //uint32_t before = *((uint32_t*)locationToFix);
+ switch ( relocationType )
+ {
+ case PPC_RELOC_LO16:
+ instruction->immediateValue = ((otherHalf << 16) | instruction->immediateValue) + slide;
+ break;
+ case PPC_RELOC_HI16:
+ instruction->immediateValue = ((((instruction->immediateValue << 16) | otherHalf) + slide) >> 16);
+ break;
+ case PPC_RELOC_HA16:
+ int16_t signedOtherHalf = (int16_t)(otherHalf & 0xffff);
+ uint32_t temp = (instruction->immediateValue << 16) + signedOtherHalf + slide;
+ if ( (temp & 0x00008000) != 0 )
+ temp += 0x00008000;
+ instruction->immediateValue = temp >> 16;
+ }
+ //uint32_t after = *((uint32_t*)locationToFix);
+ //dyld::log("dyld: ppc fixup %0p type %d from 0x%08X to 0x%08X\n", locationToFix, relocationType, before, after);
+}
+#endif
+
+#if __ppc__ || __i386__
+void ImageLoaderMachO::resetPreboundLazyPointers(const LinkContext& context, uintptr_t relocBase)
+{
+ // loop through all local (internal) relocation records looking for pre-bound-lazy-pointer values
+ register const uintptr_t slide = this->fSlide;
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->locreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nlocrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ if ( (reloc->r_address & R_SCATTERED) != 0 ) {
+ const struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
+ if (sreloc->r_length == RELOC_SIZE) {
+ uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
+ switch(sreloc->r_type) {
+ #if __ppc__
+ case PPC_RELOC_PB_LA_PTR:
+ *locationToFix = sreloc->r_value + slide;
+ break;
+ #endif
+ #if __i386__
+ case GENERIC_RELOC_PB_LA_PTR:
+ *locationToFix = sreloc->r_value + slide;
+ break;
+ #endif
+ }
+ }
+ }
+ }
+}
+#endif
+
+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());
+ }
+ }
+
+ // cache values that are used in the following loop
+ const uintptr_t relocBase = this->getRelocBase();
+ register const uintptr_t slide = this->fSlide;
+
+ //dyld::log("slide=0x%08lX for %s\n", slide, this->getPath());
+
+#if __ppc__ || __i386__
+ // 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, relocBase);
+#endif
+
+ // if in shared cache and got here, then we depend on something not in the shared cache
+ if ( fInSharedCache )
+ context.notifySharedCacheInvalid();
+
+ // if loaded at preferred address, no rebasing necessary
+ if ( slide == 0 )
+ return;
+
+#if TEXT_RELOC_SUPPORT
+ // if there are __TEXT fixups, temporarily make __TEXT writable
+ if ( fTextSegmentWithFixups != NULL )
+ fTextSegmentWithFixups->tempWritable(context, this);
+#endif
+ // loop through all local (internal) relocation records
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->locreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nlocrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+#if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(reloc);
+#endif
+ #if __x86_64__
+ // only one kind of local relocation supported for x86_64
+ if ( reloc->r_length != 3 )
+ throw "bad local relocation length";
+ if ( reloc->r_type != X86_64_RELOC_UNSIGNED )
+ throw "unknown local relocation type";
+ if ( reloc->r_pcrel != 0 )
+ throw "bad local relocation pc_rel";
+ if ( reloc->r_extern != 0 )
+ throw "extern relocation found with local relocations";
+ *((uintptr_t*)(reloc->r_address + relocBase)) += slide;
+ #else
+ if ( (reloc->r_address & R_SCATTERED) == 0 ) {
+ if ( reloc->r_symbolnum == R_ABS ) {
+ // ignore absolute relocations
+ }
+ else if (reloc->r_length == RELOC_SIZE) {
+ switch(reloc->r_type) {
+ case GENERIC_RELOC_VANILLA:
+ *((uintptr_t*)(reloc->r_address + relocBase)) += slide;
+ break;
+ #if __ppc__
+ case PPC_RELOC_HI16:
+ case PPC_RELOC_LO16:
+ case PPC_RELOC_HA16:
+ // some tools leave object file relocations in linked images
+ otherRelocsPPC((uintptr_t*)(reloc->r_address + relocBase), reloc->r_type, reloc[1].r_address, slide);
+ ++reloc; // these relocations come in pairs, skip next
+ break;
+ #endif
+ default:
+ throw "unknown local relocation type";
+ }
+ }
+ else {
+ throw "bad local relocation length";
+ }
+ }
+ else {
+ const struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
+ if (sreloc->r_length == RELOC_SIZE) {
+ uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
+ switch(sreloc->r_type) {
+ case GENERIC_RELOC_VANILLA:
+ *locationToFix += slide;
+ break;
+ #if __ppc__
+ case PPC_RELOC_HI16:
+ case PPC_RELOC_LO16:
+ case PPC_RELOC_HA16:
+ // Metrowerks compiler sometimes leaves object file relocations in linked images???
+ ++reloc; // these relocations come in pairs, get next one
+ otherRelocsPPC(locationToFix, sreloc->r_type, reloc->r_address, slide);
+ break;
+ case PPC_RELOC_PB_LA_PTR:
+ // do nothing
+ break;
+ #elif __ppc64__
+ case PPC_RELOC_PB_LA_PTR:
+ // needed for compatibility with ppc64 binaries built with the first ld64
+ // which used PPC_RELOC_PB_LA_PTR relocs instead of GENERIC_RELOC_VANILLA for lazy pointers
+ *locationToFix += slide;
+ break;
+ #elif __i386__
+ case GENERIC_RELOC_PB_LA_PTR:
+ // do nothing
+ break;
+ #endif
+ default:
+ throw "unknown local scattered relocation type";
+ }
+ }
+ else {
+ throw "bad local scattered relocation length";
+ }
+ }
+ #endif // x86_64
+ }
+
+#if TEXT_RELOC_SUPPORT
+ // if there were __TEXT fixups, restore write protection
+ if ( fTextSegmentWithFixups != NULL ) {
+ fTextSegmentWithFixups->setPermissions(context,this);
+ sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(this), fTextSegmentWithFixups->getSize());
+ }
+#endif
+ // update stats
+ fgTotalRebaseFixups += fDynamicInfo->nlocrel;
+}
+
+
+const struct macho_nlist* ImageLoaderMachO::binarySearchWithToc(const char* key, const char stringPool[], const struct macho_nlist symbols[],
+ const struct dylib_table_of_contents toc[], uint32_t symbolCount, uint32_t hintIndex) const
+{
+ int32_t high = symbolCount-1;
+ int32_t mid = hintIndex;
+
+ // handle out of range hint
+ if ( mid >= (int32_t)symbolCount ) {
+ mid = symbolCount/2;
+ ++ImageLoaderMachO::fgUnhintedBinaryTreeSearchs;
+ }
+ else {
+ ++ImageLoaderMachO::fgHintedBinaryTreeSearchs;
+ }
+ ++fgTotalBindImageSearches;
+
+ //dyld::log("dyld: binarySearchWithToc for %s in %s\n", key, this->getShortName());
+
+ for (int32_t low = 0; low <= high; mid = (low+high)/2) {
+ const uint32_t index = toc[mid].symbol_index;
+ const struct macho_nlist* pivot = &symbols[index];
+ const char* pivotStr = &stringPool[pivot->n_un.n_strx];
+#if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(&toc[mid]);
+ noteAccessedLinkEditAddress(pivot);
+ noteAccessedLinkEditAddress(pivotStr);
+#endif
+ int cmp = astrcmp(key, pivotStr);
+ if ( cmp == 0 )
+ return pivot;
+ if ( cmp > 0 ) {
+ // key > pivot
+ low = mid + 1;
+ }
+ else {
+ // key < pivot
+ high = mid - 1;
+ }
+ }
+ return NULL;
+}
+
+const struct macho_nlist* ImageLoaderMachO::binarySearch(const char* key, const char stringPool[], const struct macho_nlist symbols[], uint32_t symbolCount) const
+{
+ // update stats
+ ++fgTotalBindImageSearches;
+ ++ImageLoaderMachO::fgUnhintedBinaryTreeSearchs;
+
+ //dyld::log("dyld: binarySearch for %s in %s, stringpool=%p, symbols=%p, symbolCount=%u\n",
+ // key, this->getShortName(), stringPool, symbols, symbolCount);
+
+ const struct macho_nlist* base = symbols;
+ for (uint32_t n = symbolCount; n > 0; n /= 2) {
+ const struct macho_nlist* pivot = &base[n/2];
+ const char* pivotStr = &stringPool[pivot->n_un.n_strx];
+#if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(pivot);
+ noteAccessedLinkEditAddress(pivotStr);
+#endif
+ int cmp = astrcmp(key, pivotStr);
+ if ( cmp == 0 )
+ return pivot;
+ if ( cmp > 0 ) {
+ // key > pivot
+ // move base to symbol after pivot
+ base = &pivot[1];
+ --n;
+ }
+ else {
+ // key < pivot
+ // keep same base
+ }
+ }
+ return NULL;
+}
+
+const ImageLoader::Symbol* ImageLoaderMachO::findExportedSymbol(const char* name, const void* hint, bool searchReExports, const ImageLoader** foundIn) const
+{
+ const struct macho_nlist* sym = NULL;
+ const struct twolevel_hint* theHint = (struct twolevel_hint*)hint;
+ if ( fDynamicInfo->tocoff == 0 )
+ sym = binarySearch(name, fStrings, &fSymbolTable[fDynamicInfo->iextdefsym], fDynamicInfo->nextdefsym);
+ else {
+ uint32_t start = fDynamicInfo->nextdefsym;
+ if ( theHint != NULL )
+ start = theHint->itoc;
+ if ( (theHint == NULL) || (theHint->isub_image == 0) ) {
+ sym = binarySearchWithToc(name, fStrings, fSymbolTable, (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff],
+ fDynamicInfo->ntoc, start);
+ }
+ }
+ if ( sym != NULL ) {
+ if ( foundIn != NULL )
+ *foundIn = (ImageLoader*)this;
+
+ return (const Symbol*)sym;
+ }
+
+ if ( searchReExports ) {
+ // hint might tell us to try a particular subimage
+ if ( (theHint != NULL) && (theHint->isub_image > 0) && (theHint->isub_image <= fLibrariesCount) ) {
+ // isub_image is an index into a list that is sorted non-rexported images first
+ uint32_t index = 0;
+ ImageLoader* target = NULL;
+ // pass one, only look at sub-frameworks
+ for (uint32_t i=0; i < fLibrariesCount; ++i) {
+ DependentLibrary& libInfo = fLibraries[i];
+ if ( libInfo.isSubFramework && (libInfo.image != NULL)) {
+ if ( ++index == theHint->isub_image ) {
+ target = libInfo.image;
+ break;
+ }
+ }
+ }
+ if (target != NULL) {
+ // pass two, only look at non-sub-framework-reexports
+ for (uint32_t i=0; i < fLibrariesCount; ++i) {
+ DependentLibrary& libInfo = fLibraries[i];
+ if ( libInfo.isReExported && !libInfo.isSubFramework && (libInfo.image != NULL) ) {
+ if ( ++index == theHint->isub_image ) {
+ target = libInfo.image;
+ break;
+ }
+ }
+ }
+ }
+ if (target != NULL) {
+ const Symbol* result = target->findExportedSymbol(name, NULL, searchReExports, foundIn);
+ if ( result != NULL )
+ return result;
+ }
+ }
+
+ // hint failed, try all sub images
+ // pass one, only look at sub-frameworks
+ for(unsigned int i=0; i < fLibrariesCount; ++i){
+ DependentLibrary& libInfo = fLibraries[i];
+ if ( (libInfo.image != NULL) && libInfo.isSubFramework ) {
+ const Symbol* result = libInfo.image->findExportedSymbol(name, NULL, searchReExports, foundIn);
+ if ( result != NULL )
+ return result;
+ }
+ }
+ // pass two, only look at non-sub-framework-reexports
+ for(unsigned int i=0; i < fLibrariesCount; ++i){
+ DependentLibrary& libInfo = fLibraries[i];
+ if ( (libInfo.image != NULL) && libInfo.isReExported && !libInfo.isSubFramework ) {
+ const Symbol* result = libInfo.image->findExportedSymbol(name, NULL, searchReExports, foundIn);
+ if ( result != NULL )
+ return result;
+ }
+ }
+ }
+
+ // last change: the hint is wrong (non-zero but actually in this image)
+ if ( (theHint != NULL) && (theHint->isub_image != 0) ) {
+ sym = binarySearchWithToc(name, fStrings, fSymbolTable, (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff],
+ fDynamicInfo->ntoc, fDynamicInfo->nextdefsym);
+ if ( sym != NULL ) {
+ if ( foundIn != NULL )
+ *foundIn = (ImageLoader*)this;
+ return (const Symbol*)sym;
+ }
+ }
+
+
+ return NULL;
+}
+
+
+
+
+uintptr_t ImageLoaderMachO::getExportedSymbolAddress(const Symbol* sym, const LinkContext& context, const ImageLoader* requestor) const
+{
+ return this->getSymbolAddress((const struct macho_nlist*)sym, requestor, context);
+}
+
+uintptr_t ImageLoaderMachO::getSymbolAddress(const struct macho_nlist* sym, const ImageLoader* requestor, const LinkContext& context) const
+{
+ uintptr_t result = sym->n_value + fSlide;
+ return result;
+}
+
+ImageLoader::DefinitionFlags ImageLoaderMachO::getExportedSymbolInfo(const Symbol* sym) const
+{
+ const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
+ if ( (nlistSym->n_desc & N_WEAK_DEF) != 0 )
+ return kWeakDefinition;
+ return kNoDefinitionOptions;
+}
+
+const char* ImageLoaderMachO::getExportedSymbolName(const Symbol* sym) const
+{
+ const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
+ return &fStrings[nlistSym->n_un.n_strx];
+}
+
+uint32_t ImageLoaderMachO::getExportedSymbolCount() const
+{
+ return fDynamicInfo->nextdefsym;
+}
+
+
+const ImageLoader::Symbol* ImageLoaderMachO::getIndexedExportedSymbol(uint32_t index) const
+{
+ if ( index < fDynamicInfo->nextdefsym ) {
+ const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iextdefsym + index];
+ return (const ImageLoader::Symbol*)sym;
+ }
+ return NULL;
+}
+
+
+uint32_t ImageLoaderMachO::getImportedSymbolCount() const
+{
+ return fDynamicInfo->nundefsym;
+}
+
+
+const ImageLoader::Symbol* ImageLoaderMachO::getIndexedImportedSymbol(uint32_t index) const
+{
+ if ( index < fDynamicInfo->nundefsym ) {
+ const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iundefsym + index];
+ return (const ImageLoader::Symbol*)sym;
+ }
+ return NULL;
+}
+
+
+ImageLoader::ReferenceFlags ImageLoaderMachO::geImportedSymbolInfo(const ImageLoader::Symbol* sym) const
+{
+ const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
+ ImageLoader::ReferenceFlags flags = kNoReferenceOptions;
+ if ( ((nlistSym->n_type & N_TYPE) == N_UNDF) && (nlistSym->n_value != 0) )
+ flags |= ImageLoader::kTentativeDefinition;
+ if ( (nlistSym->n_desc & N_WEAK_REF) != 0 )
+ flags |= ImageLoader::kWeakReference;
+ return flags;
+}
+
+
+const char* ImageLoaderMachO::getImportedSymbolName(const ImageLoader::Symbol* sym) const
+{
+ const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
+ return &fStrings[nlistSym->n_un.n_strx];
+}
+
+
+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);
+ }
+ return false;
+}
+
+
+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;
+}
+
+
+bool ImageLoaderMachO::symbolRequiresCoalescing(const struct macho_nlist* symbol)
+{
+ // if a define and weak ==> coalesced
+ if ( ((symbol->n_type & N_TYPE) == N_SECT) && ((symbol->n_desc & N_WEAK_DEF) != 0) )
+ return true;
+ // if an undefine and not referencing a weak symbol ==> coalesced
+ if ( ((symbol->n_type & N_TYPE) != N_SECT) && ((symbol->n_desc & N_REF_TO_WEAK) != 0) )
+ return true;
+
+ // regular symbol
+ return false;
+}
+
+
+static void __attribute__((noreturn)) 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);
+}
+
+uintptr_t ImageLoaderMachO::resolveUndefined(const LinkContext& context, const struct macho_nlist* undefinedSymbol, bool twoLevel, const ImageLoader** foundIn)
+{
+ ++fgTotalBindSymbolsResolved;
+ const char* symbolName = &fStrings[undefinedSymbol->n_un.n_strx];
+
+#if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(undefinedSymbol);
+ noteAccessedLinkEditAddress(symbolName);
+#endif
+ if ( context.bindFlat || !twoLevel ) {
+ // flat lookup
+ if ( ((undefinedSymbol->n_type & N_PEXT) != 0) && ((undefinedSymbol->n_type & N_TYPE) == N_SECT) ) {
+ // is a multi-module private_extern internal reference that the linker did not optimize away
+ uintptr_t addr = this->getSymbolAddress(undefinedSymbol, this, context);
+ *foundIn = this;
+ return addr;
+ }
+ const Symbol* sym;
+ if ( context.flatExportFinder(symbolName, &sym, foundIn) ) {
+ if ( (*foundIn != this) && !(*foundIn)->neverUnload() )
+ this->addDynamicReference(*foundIn);
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ }
+ // if a bundle is loaded privately the above will not find its exports
+ if ( this->isBundle() && this->hasHiddenExports() ) {
+ // look in self for needed symbol
+ sym = this->findExportedSymbol(symbolName, NULL, false, foundIn);
+ if ( sym != NULL )
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ }
+ if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
+ // definition can't be found anywhere
+ // if reference is weak_import, then it is ok, just return 0
+ return 0;
+ }
+ throwSymbolNotFound(symbolName, this->getPath(), "flat namespace");
+ }
+ else {
+ // symbol requires searching images with coalesced symbols (not done during prebinding)
+ if ( !context.prebinding && this->needsCoalescing() && symbolRequiresCoalescing(undefinedSymbol) ) {
+ const Symbol* sym;
+ if ( context.coalescedExportFinder(symbolName, &sym, foundIn) ) {
+ if ( (*foundIn != this) && !(*foundIn)->neverUnload() )
+ this->addDynamicReference(*foundIn);
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ }
+ //throwSymbolNotFound(symbolName, this->getPath(), "coalesced namespace");
+ //dyld::log("dyld: coalesced symbol %s not found in any coalesced image, falling back to two-level lookup", symbolName);
+ }
+
+ // if this is a real definition (not an undefined symbol) there is no ordinal
+ if ( (undefinedSymbol->n_type & N_TYPE) == N_SECT ) {
+ // static linker should never generate this case, but if it does, do something sane
+ uintptr_t addr = this->getSymbolAddress(undefinedSymbol, this, context);
+ *foundIn = this;
+ return addr;
+ }
+
+ // two level lookup
+ void* hint = NULL;
+ ImageLoader* target = NULL;
+ uint8_t ord = GET_LIBRARY_ORDINAL(undefinedSymbol->n_desc);
+ if ( ord == EXECUTABLE_ORDINAL ) {
+ target = context.mainExecutable;
+ }
+ else if ( ord == SELF_LIBRARY_ORDINAL ) {
+ target = this;
+ }
+ else if ( ord == DYNAMIC_LOOKUP_ORDINAL ) {
+ // rnielsen: HACKHACK
+ // flat lookup
+ const Symbol* sym;
+ if ( context.flatExportFinder(symbolName, &sym, foundIn) )
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ // no image has exports this symbol
+ // either report error or hope ZeroLink can just-in-time load an image
+ context.undefinedHandler(symbolName);
+ // try looking again
+ if ( context.flatExportFinder(symbolName, &sym, foundIn) )
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+
+ throwSymbolNotFound(symbolName, this->getPath(), "dynamic lookup");
+ }
+ else if ( ord <= fLibrariesCount ) {
+ DependentLibrary& libInfo = fLibraries[ord-1];
+ target = libInfo.image;
+ if ( (target == NULL) && (((undefinedSymbol->n_desc & N_WEAK_REF) != 0) || !libInfo.required) ) {
+ // if target library not loaded and reference is weak or library is weak return 0
+ return 0;
+ }
+ }
+ else {
+ dyld::throwf("bad mach-o binary, library ordinal (%u) too big (max %u) for symbol %s in %s",
+ ord, fLibrariesCount, symbolName, this->getPath());
+ }
+
+ if ( target == NULL ) {
+ //dyld::log("resolveUndefined(%s) in %s\n", symbolName, this->getPath());
+ throw "symbol not found";
+ }
+
+ // interpret hint
+ if ( fTwoLevelHints != NULL ) {
+ uint32_t symIndex = undefinedSymbol - fSymbolTable;
+ int32_t undefinedIndex = symIndex - fDynamicInfo->iundefsym;
+ if ( (undefinedIndex >= 0) && ((uint32_t)undefinedIndex < fDynamicInfo->nundefsym) ) {
+ const struct twolevel_hint* hints = (struct twolevel_hint*)(&fLinkEditBase[fTwoLevelHints->offset]);
+ const struct twolevel_hint* theHint = &hints[undefinedIndex];
+ hint = (void*)theHint;
+ }
+ }
+
+ const Symbol* sym = target->findExportedSymbol(symbolName, hint, true, foundIn);
+ if ( sym!= NULL ) {
+ return (*foundIn)->getExportedSymbolAddress(sym, context, this);
+ }
+ else if ( (undefinedSymbol->n_type & N_PEXT) != 0 ) {
+ // don't know why the static linker did not eliminate the internal reference to a private extern definition
+ *foundIn = this;
+ return this->getSymbolAddress(undefinedSymbol, this, context);
+ }
+ else if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
+ // if definition not found and reference is weak return 0
+ return 0;
+ }
+
+ // nowhere to be found
+ throwSymbolNotFound(symbolName, this->getPath(), target->getPath());
+ }
+}
+
+// returns if 'addr' is within the address range of section 'sectionIndex'
+// fSlide is not used. 'addr' is assumed to be a prebound address in this image
+bool ImageLoaderMachO::isAddrInSection(uintptr_t addr, uint8_t sectionIndex)
+{
+ uint8_t currentSectionIndex = 1;
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (unsigned long i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ if ( (currentSectionIndex <= sectionIndex) && (sectionIndex < currentSectionIndex+seg->nsects) ) {
+ // 'sectionIndex' is in this segment, get section info
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const section = §ionsStart[sectionIndex-currentSectionIndex];
+ return ( (section->addr <= addr) && (addr < section->addr+section->size) );
+ }
+ else {
+ // 'sectionIndex' not in this segment, skip to next segment
+ currentSectionIndex += seg->nsects;
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+ return false;
+}
+
+void ImageLoaderMachO::doBindExternalRelocations(const LinkContext& context, bool onlyCoalescedSymbols)
+{
+ const uintptr_t relocBase = this->getRelocBase();
+ const bool twoLevel = this->usesTwoLevelNameSpace();
+ const bool prebound = this->isPrebindable();
+
+#if TEXT_RELOC_SUPPORT
+ // if there are __TEXT fixups, temporarily make __TEXT writable
+ if ( fTextSegmentWithFixups != NULL )
+ fTextSegmentWithFixups->tempWritable(context, this);
+#endif
+ // cache last lookup
+ const struct macho_nlist* lastUndefinedSymbol = NULL;
+ uintptr_t symbolAddr = 0;
+ const ImageLoader* image = NULL;
+
+ // loop through all external relocation records and bind each
+ const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
+ const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
+ for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ if (reloc->r_length == RELOC_SIZE) {
+ switch(reloc->r_type) {
+ case POINTER_RELOC:
+ {
+ const struct macho_nlist* undefinedSymbol = &fSymbolTable[reloc->r_symbolnum];
+ // if only processing coalesced symbols and this one does not require coalesceing, skip to next
+ if ( onlyCoalescedSymbols && !symbolRequiresCoalescing(undefinedSymbol) )
+ continue;
+ uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
+ uintptr_t value = *location;
+ bool symbolAddrCached = true;
+ #if __i386__
+ if ( reloc->r_pcrel ) {
+ value += (uintptr_t)location + 4 - fSlide;
+ }
+ #endif
+ if ( prebound ) {
+ // we are doing relocations, so prebinding was not usable
+ // in a prebound executable, the n_value field of an undefined symbol is set to the address where the symbol was found when prebound
+ // so, subtracting that gives the initial displacement which we need to add to the newly found symbol address
+ // if mach-o relocation structs had an "addend" field this complication would not be necessary.
+ if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_WEAK_DEF) != 0) ) {
+ // weak symbols need special casing, since *location may have been prebound to a definition in another image.
+ // If *location is currently prebound to somewhere in the same section as the weak definition, we assume
+ // that we can subtract off the weak symbol address to get the addend.
+ // If prebound elsewhere, we've lost the addend and have to assume it is zero.
+ // The prebinding to elsewhere only happens with 10.4+ update_prebinding which only operates on a small set of Apple dylibs
+ if ( (value == undefinedSymbol->n_value) || this->isAddrInSection(value, undefinedSymbol->n_sect) )
+ value -= undefinedSymbol->n_value;
+ else
+ value = 0;
+ }
+ else {
+ // is undefined or non-weak symbol, so do subtraction to get addend
+ value -= undefinedSymbol->n_value;
+ }
+ }
+ // if undefinedSymbol is same as last time, then symbolAddr and image will resolve to the same too
+ if ( undefinedSymbol != lastUndefinedSymbol ) {
+ symbolAddr = this->resolveUndefined(context, undefinedSymbol, twoLevel, &image);
+ lastUndefinedSymbol = undefinedSymbol;
+ symbolAddrCached = false;
+ }
+ if ( context.verboseBind ) {
+ const char *path = NULL;
+ if ( image != NULL ) {
+ path = image->getShortName();
+ }
+ const char* cachedString = "(cached)";
+ if ( !symbolAddrCached )
+ cachedString = "";
+ if ( value == 0 ) {
+ dyld::log("dyld: bind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX%s\n",
+ this->getShortName(), (uintptr_t)location,
+ path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr, cachedString);
+ }
+ else {
+ dyld::log("dyld: bind: %s:0x%08lX = %s:%s, *0x%08lX = 0x%08lX%s + %ld\n",
+ this->getShortName(), (uintptr_t)location,
+ path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr, cachedString, value);
+ }
+ }
+ value += symbolAddr;
+ #if __i386__
+ if ( reloc->r_pcrel ) {
+ *location = value - ((uintptr_t)location + 4);
+ }
+ else {
+ // don't dirty page if prebound value was correct
+ if ( !prebound || (*location != value) )
+ *location = value;
+ }
+ #else
+ // don't dirty page if prebound value was correct
+ if ( !prebound || (*location != value) )
+ *location = value;
+ #endif
+ // update stats
+ ++fgTotalBindFixups;
+ }
+ break;
+ default:
+ throw "unknown external relocation type";
+ }
+ }
+ else {
+ throw "bad external relocation length";
+ }
+ }
+
+#if TEXT_RELOC_SUPPORT
+ // if there were __TEXT fixups, restore write protection
+ if ( fTextSegmentWithFixups != NULL ) {
+ fTextSegmentWithFixups->setPermissions(context, this);
+ sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(this), fTextSegmentWithFixups->getSize());
+ }
+#endif
+}
+
+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 (ImageLoader::SegmentIterator it = this->beginSegments(); it != this->endSegments(); ++it ) {
+ Segment* seg = *it;
+ uintptr_t segEnd = seg->getActualLoadAddress(this) + seg->getSize();
+ if ( segEnd > lastAddress )
+ lastAddress = segEnd;
+ }
+ return (const void*)lastAddress;
+}
+
+uintptr_t ImageLoaderMachO::bindIndirectSymbol(uintptr_t* ptrToBind, const struct macho_section* sect, const char* symbolName, uintptr_t targetAddr, const ImageLoader* targetImage, const LinkContext& context)
+{
+ if ( context.verboseBind ) {
+ const char* path = NULL;
+ if ( targetImage != NULL )
+ path = targetImage->getShortName();
+ dyld::log("dyld: bind: %s:%s$%s = %s:%s, *0x%08lx = 0x%08lx\n",
+ this->getShortName(), symbolName, (((sect->flags & SECTION_TYPE)==S_NON_LAZY_SYMBOL_POINTERS) ? "non_lazy_ptr" : "lazy_ptr"),
+ path, symbolName, (uintptr_t)ptrToBind, targetAddr);
+ }
+ if ( context.bindingHandler != NULL ) {
+ const char* path = NULL;
+ if ( targetImage != NULL )
+ path = targetImage->getShortName();
+ targetAddr = (uintptr_t)context.bindingHandler(path, symbolName, (void *)targetAddr);
+ }
+#if __i386__
+ // i386 has special self-modifying stubs that change from "CALL rel32" to "JMP rel32"
+ if ( ((sect->flags & SECTION_TYPE) == S_SYMBOL_STUBS) && ((sect->flags & S_ATTR_SELF_MODIFYING_CODE) != 0) && (sect->reserved2 == 5) ) {
+ uint32_t rel32 = targetAddr - (((uint32_t)ptrToBind)+5);
+ // re-write instruction in a thread-safe manner
+ // use 8-byte compare-and-swap to alter 5-byte jump table entries
+ // loop is required in case the extra three bytes that cover the next entry are altered by another thread
+ bool done = false;
+ while ( !done ) {
+ volatile int64_t* jumpPtr = (int64_t*)ptrToBind;
+ int pad = 0;
+ // By default the three extra bytes swapped follow the 5-byte JMP.
+ // But, if the 5-byte jump is up against the end of the __IMPORT segment
+ // We don't want to access bytes off the end of the segment, so we shift
+ // the extra bytes to precede the 5-byte JMP.
+ if ( (((uint32_t)ptrToBind + 8) & 0x00000FFC) == 0x00000000 ) {
+ jumpPtr = (int64_t*)((uint32_t)ptrToBind - 3);
+ pad = 3;
+ }
+ int64_t oldEntry = *jumpPtr;
+ union {
+ int64_t int64;
+ uint8_t bytes[8];
+ } newEntry;
+ newEntry.int64 = oldEntry;
+ newEntry.bytes[pad+0] = 0xE9; // JMP rel32
+ newEntry.bytes[pad+1] = rel32 & 0xFF;
+ newEntry.bytes[pad+2] = (rel32 >> 8) & 0xFF;
+ newEntry.bytes[pad+3] = (rel32 >> 16) & 0xFF;
+ newEntry.bytes[pad+4] = (rel32 >> 24) & 0xFF;
+ done = OSAtomicCompareAndSwap64Barrier(oldEntry, newEntry.int64, (int64_t*)jumpPtr);
+ }
+ }
+ else
+#endif
+ *ptrToBind = targetAddr;
+ return targetAddr;
+}
+
+
+uintptr_t ImageLoaderMachO::doBindLazySymbol(uintptr_t* lazyPointer, const LinkContext& context)
+{
+ // scan for all non-lazy-pointer sections
+ const bool twoLevel = this->usesTwoLevelNameSpace();
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ uint32_t symbolIndex = INDIRECT_SYMBOL_LOCAL;
+ if ( type == S_LAZY_SYMBOL_POINTERS ) {
+ const uint32_t pointerCount = sect->size / sizeof(uintptr_t);
+ uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
+ if ( (lazyPointer >= symbolPointers) && (lazyPointer < &symbolPointers[pointerCount]) ) {
+ const uint32_t indirectTableOffset = sect->reserved1;
+ const uint32_t lazyIndex = lazyPointer - symbolPointers;
+ symbolIndex = indirectTable[indirectTableOffset + lazyIndex];
+ }
+ }
+ #if __i386__
+ else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
+ // 5 bytes stubs on i386 are new "fast stubs"
+ uint8_t* const jmpTableBase = (uint8_t*)(sect->addr + fSlide);
+ uint8_t* const jmpTableEnd = jmpTableBase + sect->size;
+ // initial CALL instruction in jump table leaves pointer to next entry, so back up
+ uint8_t* const jmpTableEntryToPatch = ((uint8_t*)lazyPointer) - 5;
+ lazyPointer = (uintptr_t*)jmpTableEntryToPatch;
+ if ( (jmpTableEntryToPatch >= jmpTableBase) && (jmpTableEntryToPatch < jmpTableEnd) ) {
+ const uint32_t indirectTableOffset = sect->reserved1;
+ const uint32_t entryIndex = (jmpTableEntryToPatch - jmpTableBase)/5;
+ symbolIndex = indirectTable[indirectTableOffset + entryIndex];
+ }
+ }
+ #endif
+ if ( symbolIndex != INDIRECT_SYMBOL_ABS && symbolIndex != INDIRECT_SYMBOL_LOCAL ) {
+ const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
+ const ImageLoader* image = NULL;
+ uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], twoLevel, &image);
+ #if __i386__
+ this->makeImportSegmentWritable(context);
+ #endif
+ symbolAddr = this->bindIndirectSymbol(lazyPointer, sect, symbolName, symbolAddr, image, context);
+ ++fgTotalLazyBindFixups;
+ #if __i386__
+ this->makeImportSegmentReadOnly(context);
+ #endif
+ return symbolAddr;
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ dyld::throwf("lazy pointer not found at address %p in image %s", lazyPointer, this->getPath());
+}
+
+
+#if __i386__
+//
+// For security the __IMPORT segments in the shared cache are normally not writable.
+// Any image can also be linked with -read_only_stubs to make their __IMPORT segments normally not writable.
+// For these images, dyld must change the page protection before updating them.
+// The spin lock is required because lazy symbol binding is done without taking the global dyld lock.
+// It keeps only one __IMPORT segment writable at a time.
+// Pre-main(), the shared cache __IMPORT segments are always writable, so we don't need to change the protection.
+//
+void ImageLoaderMachO::makeImportSegmentWritable(const LinkContext& context)
+{
+ if ( fReadOnlyImportSegment != NULL ) {
+ if ( fInSharedCache ) {
+ if ( context.startedInitializingMainExecutable ) {
+ _spin_lock(&fgReadOnlyImportSpinLock);
+ context.makeSharedCacheImportSegmentsWritable(true);
+ }
+ }
+ else {
+ _spin_lock(&fgReadOnlyImportSpinLock);
+ fReadOnlyImportSegment->tempWritable(context, this);
+ }
+ }
+}
+
+void ImageLoaderMachO::makeImportSegmentReadOnly(const LinkContext& context)
+{
+ if ( fReadOnlyImportSegment != NULL ) {
+ if ( fInSharedCache ) {
+ if ( context.startedInitializingMainExecutable ) {
+ context.makeSharedCacheImportSegmentsWritable(false);
+ _spin_unlock(&fgReadOnlyImportSpinLock);
+ }
+ }
+ else {
+ fReadOnlyImportSegment->setPermissions(context, this);
+ _spin_unlock(&fgReadOnlyImportSpinLock);
+ }
+ }
+}
+#endif
+
+void ImageLoaderMachO::doBindIndirectSymbolPointers(const LinkContext& context, bool bindNonLazys, bool bindLazys, bool onlyCoalescedSymbols)
+{
+#if __i386__
+ this->makeImportSegmentWritable(context);
+#endif
+ // scan for all non-lazy-pointer sections
+ const bool twoLevel = this->usesTwoLevelNameSpace();
+ const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ uint32_t elementSize = sizeof(uintptr_t);
+ uint32_t elementCount = sect->size / elementSize;
+ if ( type == S_NON_LAZY_SYMBOL_POINTERS ) {
+ if ( ! bindNonLazys )
+ continue;
+ }
+ else if ( type == S_LAZY_SYMBOL_POINTERS ) {
+ // process each symbol pointer in this section
+ fgTotalPossibleLazyBindFixups += elementCount;
+ if ( ! bindLazys )
+ continue;
+ }
+ #if __i386__
+ else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
+ // process each jmp entry in this section
+ elementCount = sect->size / 5;
+ elementSize = 5;
+ fgTotalPossibleLazyBindFixups += elementCount;
+ if ( ! bindLazys )
+ continue;
+ }
+ #endif
+ else {
+ continue;
+ }
+ const uint32_t indirectTableOffset = sect->reserved1;
+ uint8_t* ptrToBind = (uint8_t*)(sect->addr + fSlide);
+ for (uint32_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
+ #if LINKEDIT_USAGE_DEBUG
+ noteAccessedLinkEditAddress(&indirectTable[indirectTableOffset + j]);
+ #endif
+ uint32_t symbolIndex = indirectTable[indirectTableOffset + j];
+ if ( symbolIndex == INDIRECT_SYMBOL_LOCAL) {
+ *((uintptr_t*)ptrToBind) += this->fSlide;
+ }
+ else if ( symbolIndex == INDIRECT_SYMBOL_ABS) {
+ // do nothing since already has absolute address
+ }
+ else {
+ const struct macho_nlist* sym = &fSymbolTable[symbolIndex];
+ if ( symbolIndex == 0 ) {
+ // This could be rdar://problem/3534709
+ if ( ((const macho_header*)fMachOData)->filetype == MH_EXECUTE ) {
+ static bool alreadyWarned = false;
+ if ( (sym->n_type & N_TYPE) != N_UNDF ) {
+ // The indirect table parallels the (non)lazy pointer sections. For
+ // instance, to find info about the fifth lazy pointer you look at the
+ // fifth entry in the indirect table. (try otool -Iv on a file).
+ // The entry in the indirect table contains an index into the symbol table.
+
+ // The bug in ld caused the entry in the indirect table to be zero
+ // (instead of a magic value that means a local symbol). So, if the
+ // symbolIndex == 0, we may be encountering the bug, or 0 may be a valid
+ // symbol table index. The check I put in place is to see if the zero'th
+ // symbol table entry is an import entry (usually it is a local symbol
+ // definition).
+ if ( context.verboseWarnings && !alreadyWarned ) {
+ dyld::log("dyld: malformed executable '%s', skipping indirect symbol to %s\n",
+ this->getPath(), &fStrings[sym->n_un.n_strx]);
+ alreadyWarned = true;
+ }
+ continue;
+ }
+ }
+ }
+ const ImageLoader* image = NULL;
+ // if only processing coalesced symbols and this one does not require coalesceing, skip to next
+ if ( onlyCoalescedSymbols && !symbolRequiresCoalescing(sym) )
+ continue;
+ uintptr_t symbolAddr;
+ symbolAddr = resolveUndefined(context, sym, twoLevel, &image);
+
+ // update pointer
+ symbolAddr = this->bindIndirectSymbol((uintptr_t*)ptrToBind, sect, &fStrings[sym->n_un.n_strx], symbolAddr, image, context);
+ // update stats
+ ++fgTotalBindFixups;
+ }
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+#if __i386__
+ this->makeImportSegmentReadOnly(context);
+#endif
+}
+
+#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);
+extern "C" void fast_stub_binding_helper_interface();
+
+
+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
+ }
+ }
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+#if __i386__
+ if ( ! this->usablePrebinding(context) ) {
+ // reset all "fast" stubs
+ this->makeImportSegmentWritable(context);
+ cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
+ // reset each jmp entry in this section
+ const uint32_t indirectTableOffset = sect->reserved1;
+ const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
+ uint8_t* start = (uint8_t*)(sect->addr + this->fSlide);
+ uint8_t* end = start + sect->size;
+ uintptr_t dyldHandler = (uintptr_t)&fast_stub_binding_helper_interface;
+ uint32_t entryIndex = 0;
+ for (uint8_t* entry = start; entry < end; entry += 5, ++entryIndex) {
+ bool installLazyHandler = true;
+ // jump table entries that cross a (64-byte) cache line boundary have the potential to cause crashes
+ // if the instruction is updated by one thread while being executed by another
+ if ( ((uint32_t)entry & 0xFFFFFFC0) != ((uint32_t)entry+4 & 0xFFFFFFC0) ) {
+ // need to bind this now to avoid a potential problem if bound lazily
+ uint32_t symbolIndex = indirectTable[indirectTableOffset + entryIndex];
+ // the latest linker marks 64-byte crossing stubs with INDIRECT_SYMBOL_ABS so they are not used
+ if ( symbolIndex != INDIRECT_SYMBOL_ABS ) {
+ const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
+ const ImageLoader* image = NULL;
+ try {
+ uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], this->usesTwoLevelNameSpace(), &image);
+ symbolAddr = this->bindIndirectSymbol((uintptr_t*)entry, sect, symbolName, symbolAddr, image, context);
+ ++fgTotalBindFixups;
+ uint32_t rel32 = symbolAddr - (((uint32_t)entry)+5);
+ entry[0] = 0xE9; // JMP rel32
+ entry[1] = rel32 & 0xFF;
+ entry[2] = (rel32 >> 8) & 0xFF;
+ entry[3] = (rel32 >> 16) & 0xFF;
+ entry[4] = (rel32 >> 24) & 0xFF;
+ installLazyHandler = false;
+ }
+ catch (const char* msg) {
+ // ignore errors when binding symbols early
+ // maybe the function is never called, and therefore erroring out now would be a regression
+ }
+ }
+ }
+ if ( installLazyHandler ) {
+ uint32_t rel32 = dyldHandler - (((uint32_t)entry)+5);
+ entry[0] = 0xE8; // CALL rel32
+ entry[1] = rel32 & 0xFF;
+ entry[2] = (rel32 >> 8) & 0xFF;
+ entry[3] = (rel32 >> 16) & 0xFF;
+ entry[4] = (rel32 >> 24) & 0xFF;
+ }
+ }
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ this->makeImportSegmentReadOnly(context);
+ }
+#endif
+}
+
+
+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", NULL, false, NULL);
+ if ( sym != NULL )
+ vars.NXArgcPtr = (int*)this->getExportedSymbolAddress(sym, context, this);
+
+ // lookup _NXArgv
+ sym = this->findExportedSymbol("_NXArgv", NULL, false, NULL);
+ if ( sym != NULL )
+ vars.NXArgvPtr = (const char***)this->getExportedSymbolAddress(sym, context, this);
+
+ // lookup _environ
+ sym = this->findExportedSymbol("_environ", NULL, false, NULL);
+ if ( sym != NULL )
+ vars.environPtr = (const char***)this->getExportedSymbolAddress(sym, context, this);
+
+ // lookup __progname
+ sym = this->findExportedSymbol("___progname", NULL, 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::doBindJustLazies(const LinkContext& context)
+{
+ // some API called requested that all lazy pointers in this image be force bound
+ this->doBindIndirectSymbolPointers(context, false, true, false);
+}
+
+void ImageLoaderMachO::doBind(const LinkContext& context, bool forceLazysBound)
+{
+ // set dyld entry points in image
+ this->setupLazyPointerHandler(context);
+
+ // if prebound and loaded at prebound address, and all libraries are same as when this was prebound, then no need to bind
+ // note: flat-namespace binaries need to have imports rebound (even if correctly prebound)
+ if ( this->usablePrebinding(context) ) {
+ // if image has coalesced symbols, then these need to be rebound, unless this is the only image with weak symbols
+ if ( this->needsCoalescing() && (fgCountOfImagesWithWeakExports > 1) ) {
+ this->doBindExternalRelocations(context, true);
+ this->doBindIndirectSymbolPointers(context, true, true, true);
+ }
+ else {
+ ++fgImagesRequiringNoFixups;
+ }
+
+ // skip binding because prebound and prebinding not disabled
+ return;
+ }
+
+ // values bound by name are stored two different ways in mach-o:
+
+ // 1) external relocations are used for data initialized to external symbols
+ this->doBindExternalRelocations(context, false);
+
+ // 2) "indirect symbols" are used for code references to external symbols
+ // if this image is in the shared cache, there is noway to reset the lazy pointers, so bind them now
+ this->doBindIndirectSymbolPointers(context, true, forceLazysBound || fInSharedCache, false);
+}
+
+void ImageLoaderMachO::doUpdateMappingPermissions(const LinkContext& context)
+{
+#if __i386__
+ if ( (fReadOnlyImportSegment != NULL) && !fInSharedCache )
+ fReadOnlyImportSegment->setPermissions(context, this);
+#endif
+}
+
+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 (unsigned long 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 (unsigned long 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;
+}
+
+#if IMAGE_NOTIFY_SUPPORT
+bool ImageLoaderMachO::hasImageNotification()
+{
+ return fHasImageNotifySection;
+}
+#endif
+
+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 (unsigned long 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 terminaton function %p in %s\n", func, this->getPath());
+ func();
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+}
+
+#if IMAGE_NOTIFY_SUPPORT
+void ImageLoaderMachO::doNotification(enum dyld_image_mode mode, uint32_t infoCount, const struct dyld_image_info info[])
+{
+ if ( fHasImageNotifySection ) {
+ 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 (unsigned long 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, "__image_notify") == 0 ) {
+ dyld_image_notifier* notes = (dyld_image_notifier*)(sect->addr + fSlide);
+ const uint32_t count = sect->size / sizeof(uintptr_t);
+ for (uint32_t i=count; i > 0; --i) {
+ dyld_image_notifier func = notes[i-1];
+ func(mode, infoCount, info);
+ }
+ }
+ }
+ }
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ }
+}
+#endif
+
+void ImageLoaderMachO::printStatistics(unsigned int imageCount)
+{
+ ImageLoader::printStatistics(imageCount);
+ //dyld::log("total hinted binary tree searches: %d\n", fgHintedBinaryTreeSearchs);
+ //dyld::log("total unhinted binary tree searches: %d\n", fgUnhintedBinaryTreeSearchs);
+ dyld::log("total images with weak exports: %d\n", fgCountOfImagesWithWeakExports);
+
+#if LINKEDIT_USAGE_DEBUG
+ dyld::log("linkedit pages accessed (%lu):\n", sLinkEditPageBuckets.size());
+#endif
+}
+
+
+ImageLoader::SegmentIterator ImageLoaderMachO::beginSegments() const
+{
+ return SegmentIterator(fSegmentsArray);
+}
+
+ImageLoader::SegmentIterator ImageLoaderMachO::endSegments() const
+{
+ return SegmentIterator(&fSegmentsArray[fSegmentsArrayCount]);
+}
+
+SegmentMachO::SegmentMachO(const struct macho_segment_command* cmd)
+ : fSegmentLoadCommand(cmd)
+{
+}
+
+SegmentMachO::~SegmentMachO()
+{
+}
+
+void SegmentMachO::adjust(const struct macho_segment_command* cmd)
+{
+ fSegmentLoadCommand = cmd;
+}
+
+void SegmentMachO::unmap(const ImageLoader* image)
+{
+ // update stats
+ --ImageLoader::fgTotalSegmentsMapped;
+ ImageLoader::fgTotalBytesMapped -= fSegmentLoadCommand->vmsize;
+ munmap((void*)(this->getActualLoadAddress(image)), fSegmentLoadCommand->vmsize);
+}
+
+
+const char* SegmentMachO::getName()
+{
+ return fSegmentLoadCommand->segname;
+}
+
+uintptr_t SegmentMachO::getSize()
+{
+ return fSegmentLoadCommand->vmsize;
+}
+
+uintptr_t SegmentMachO::getFileSize()
+{
+ return fSegmentLoadCommand->filesize;
+}
+
+uintptr_t SegmentMachO::getFileOffset()
+{
+ return fSegmentLoadCommand->fileoff;
+}
+
+bool SegmentMachO::readable()
+{
+ return ( (fSegmentLoadCommand->initprot & VM_PROT_READ) != 0);
+}
+
+bool SegmentMachO::writeable()
+{
+ return ((fSegmentLoadCommand->initprot & VM_PROT_WRITE) != 0);
+}
+
+bool SegmentMachO::executable()
+{
+ return ((fSegmentLoadCommand->initprot & VM_PROT_EXECUTE) != 0);
+}
+
+bool SegmentMachO::unaccessible()
+{
+ return (fSegmentLoadCommand->initprot == 0);
+}
+
+#if TEXT_RELOC_SUPPORT
+bool SegmentMachO::hasFixUps()
+{
+ // scan sections for fix-up bit
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)fSegmentLoadCommand + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[fSegmentLoadCommand->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( (sect->flags & (S_ATTR_EXT_RELOC | S_ATTR_LOC_RELOC)) != 0 )
+ return true;
+ }
+ return false;
+}
+#endif
+
+#if __i386__
+bool SegmentMachO::readOnlyImportStubs()
+{
+ return ( (fSegmentLoadCommand->initprot & VM_PROT_EXECUTE)
+ && ((fSegmentLoadCommand->initprot & VM_PROT_WRITE) == 0)
+ && (strcmp(fSegmentLoadCommand->segname, "__IMPORT") == 0) );
+}
+#endif
+
+uintptr_t SegmentMachO::getActualLoadAddress(const ImageLoader* inImage)
+{
+ return fSegmentLoadCommand->vmaddr + inImage->getSlide();
+}
+
+uintptr_t SegmentMachO::getPreferredLoadAddress()
+{
+ return fSegmentLoadCommand->vmaddr;
+}
+
+bool SegmentMachO::hasPreferredLoadAddress()
+{
+ return (fSegmentLoadCommand->vmaddr != 0);
+}
+
+
+Segment* SegmentMachO::next(Segment* location)
+{
+ return &((SegmentMachO*)location)[1];
+}
+
+
+
+
+
+