+/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
+ *
+ * Copyright (c) 2004-2005 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+#include <string.h>
+#include <fcntl.h>
+#include <sys/types.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>
+#if __ppc__ || __ppc64__
+ #include <mach-o/ppc/reloc.h>
+#endif
+
+#include "ImageLoaderMachO.h"
+#include "mach-o/dyld_gdb.h"
+
+// no header for this yet, rdar://problem/3850825
+extern "C" void sys_icache_invalidate(void *, size_t);
+
+// optimize strcmp for ppc
+#if __ppc__
+ #include <ppc_intrinsics.h>
+#else
+ #define astrcmp(a,b) strcmp(a,b)
+#endif
+
+// relocation_info.r_length field has value 3 for 64-bit executables and value 2 for 32-bit executables
+#if __LP64__
+ #define RELOC_SIZE 3
+ #define LC_SEGMENT_COMMAND LC_SEGMENT_64
+ #define LC_ROUTINES_COMMAND LC_ROUTINES_64
+ struct macho_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
+
+
+uint32_t ImageLoaderMachO::fgHintedBinaryTreeSearchs = 0;
+uint32_t ImageLoaderMachO::fgUnhintedBinaryTreeSearchs = 0;
+
+
+//#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);
+ sLinkEditPageBuckets.insert(page);
+ fprintf(stderr, "dyld: accessing page 0x%08lX in __LINKEDIT of %s\n", page, dyld::findImageContainingAddress(addr)->getPath());
+ }
+#endif
+
+// only way to share initialization in C++
+void ImageLoaderMachO::init()
+{
+ fMachOData = NULL;
+ fLinkEditBase = NULL;
+ fSymbolTable = NULL;
+ fStrings = NULL;
+ fDynamicInfo = NULL;
+ fSlide = 0;
+ fIsSplitSeg = false;
+ fHasSubLibraries= false;
+ fHasSubUmbrella = false;
+ fDashInit = NULL;
+ fModInitSection = NULL;
+ fModTermSection = NULL;
+ fDATAdyld = NULL;
+ fImageNotifySection = NULL;
+ fTwoLevelHints = NULL;
+ fDylibID = NULL;
+ fReExportThruFramework = NULL;
+ fTextSegmentWithFixups = NULL;
+}
+
+// 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 )
+ ImageLoader::mapSegments((const void*)mh, len, context);
+
+ // get pointers to interesting things
+ this->parseLoadCmds();
+}
+
+
+// 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();
+}
+
+
+
+
+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)];
+
+ // construct Segment object for each LC_SEGMENT cmd and add to list
+ const struct load_command* cmd = cmds;
+ for (unsigned long i = 0; i < cmd_count; ++i) {
+ if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
+ fSegments.push_back(new SegmentMachO((struct macho_segment_command*)cmd, this, fileData));
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+
+
+
+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 );
+}
+
+#if !__LP64__ // split segs not supported for 64-bits
+
+#if 1 // 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;
+};
+
+// 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
+{
+ //fprintf(stderr, "%s(%i, %u, %8p, %8p)\n", __func__, fd, regionCount, regions, slide);
+ //for ( unsigned int i=0; i < regionCount; ++i) {
+ // fprintf(stderr, "\taddress=0x%08llX, size=0x%08llX\n", regions[i].address, regions[i].size);
+ //}
+ int r = syscall(299, fd, regionCount, regions, slide);
+// if(0 != r)
+// fprintf(stderr, "%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
+{
+ //fprintf(stderr, "%s(%u, %8p)\n", __func__, rangeCount, ranges);
+ int r = syscall(300, rangeCount, ranges);
+// if(0 != r)
+// fprintf(stderr, "%s(%u, %8p) errno=%i (%s)\n", __func__, rangeCount, ranges, errno, strerror(errno));
+ return r;
+}
+#define KERN_SHREG_PRIVATIZABLE 54
+#endif // hack until kernel headers and glue are in system
+
+static uintptr_t sNextAltLoadAddress
+#if __ppc_
+ = 0xC0000000;
+#else
+ = 0;
+#endif
+
+
+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;
+}
+
+int
+ImageLoaderMachO::sharedRegionMapFilePrivateOutside(int fd,
+ uint64_t offsetInFat,
+ uint64_t lenInFat,
+ uint64_t fileLen,
+ const LinkContext& context)
+{
+ const unsigned int segmentCount = fSegments.size();
+ 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 )
+ 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 ) {
+ // do nothing vm_allocate() zero-fills by default
+ }
+ 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;
+ //fprintf(stderr, "mmap(%p, 0x%08lX, block=0x%08X, %s\n", mmapAddress, size, biggestDiff, fPath);
+ mmapAddress = mmap(mmapAddress, size, protection, MAP_FILE | 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 ) {
+ fprintf(stderr, "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 = fSegments[segIndex];
+ const _shared_region_mapping_np* entry = ®ions[entryIndex];
+ if ( (entry->init_prot & VM_PROT_ZF) == 0 )
+ fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), seg->getActualLoadAddress(), seg->getActualLoadAddress()+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;
+ fprintf(stderr, "%18s at 0x%08lX->0x%08lX (zerofill)\n",
+ seg->getName(), (uintptr_t)(seg->getActualLoadAddress() + segOffset), (uintptr_t)(seg->getActualLoadAddress() + segOffset + nextEntry->size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+
+ return r;
+}
+
+
+void ImageLoaderMachO::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
+{
+ enum SharedRegionState
+ {
+ kSharedRegionStartState = 0,
+ kSharedRegionLoadFileState,
+ kSharedRegionMapFileState,
+ kSharedRegionMapFilePrivateState,
+ kSharedRegionMapFilePrivateOutsideState,
+ };
+ static SharedRegionState sSharedRegionState = kSharedRegionStartState;
+
+ // non-split segment libraries handled by super class
+ if ( !fIsSplitSeg )
+ return ImageLoader::mapSegments(fd, offsetInFat, lenInFat, fileLen, context);
+
+ if ( kSharedRegionStartState == sSharedRegionState ) {
+ if ( hasSharedRegionMapFile() ) {
+ if ( (context.sharedRegionMode == kUsePrivateSharedRegion) || context.slideAndPackDylibs ) {
+ sharedRegionMakePrivate(context);
+ sSharedRegionState = kSharedRegionMapFilePrivateState;
+ }
+ else if ( context.sharedRegionMode == kDontUseSharedRegion ) {
+ sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
+ }
+ else {
+ sSharedRegionState = kSharedRegionMapFileState;
+ }
+ }
+ else {
+ sSharedRegionState = kSharedRegionLoadFileState;
+ }
+ }
+
+ if ( kSharedRegionLoadFileState == sSharedRegionState ) {
+ if ( 0 != sharedRegionLoadFile(fd, offsetInFat, lenInFat, fileLen, context) ) {
+ sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
+ }
+ }
+ else
+ if ( kSharedRegionMapFileState == sSharedRegionState ) {
+ if ( 0 != sharedRegionMapFile(fd, offsetInFat, lenInFat, fileLen, context) ) {
+ sharedRegionMakePrivate(context);
+ sSharedRegionState = kSharedRegionMapFilePrivateState;
+ }
+ }
+
+ if ( kSharedRegionMapFilePrivateState == sSharedRegionState ) {
+ if ( 0 != sharedRegionMapFilePrivate(fd, offsetInFat, lenInFat, fileLen, context) ) {
+ sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
+ }
+ }
+
+ if ( kSharedRegionMapFilePrivateOutsideState == sSharedRegionState ) {
+ if ( 0 != sharedRegionMapFilePrivateOutside(fd, offsetInFat, lenInFat, fileLen, context) ) {
+ throw "mapping error";
+ }
+ }
+}
+
+unsigned int
+ImageLoaderMachO::getExtraZeroFillEntriesCount()
+{
+ // calculate mapping entries
+ const unsigned int segmentCount = fSegments.size();
+ unsigned int extraZeroFillEntries = 0;
+ for(unsigned int i=0; i < segmentCount; ++i){
+ Segment* seg = fSegments[i];
+ if ( seg->hasTrailingZeroFill() )
+ ++extraZeroFillEntries;
+ }
+
+ return extraZeroFillEntries;
+}
+
+void
+ImageLoaderMachO::initMappingTable(uint64_t offsetInFat,
+ _shared_region_mapping_np *mappingTable)
+{
+ unsigned int segmentCount = fSegments.size();
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = fSegments[segIndex];
+ _shared_region_mapping_np* entry = &mappingTable[entryIndex];
+ entry->address = seg->getActualLoadAddress();
+ 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::sharedRegionMakePrivate(const LinkContext& context)
+{
+ if ( context.verboseMapping )
+ fprintf(stderr, "dyld: making shared regions private\n");
+
+ // shared mapping failed, so make private copy of shared region and try mapping private
+ RegionsVector allRegions;
+ context.getAllMappedRegions(allRegions);
+ std::vector<_shared_region_range_np> splitSegRegions;
+ const unsigned int allRegiontCount = allRegions.size();
+ for(unsigned int i=0; i < allRegiontCount; ++i){
+ MappedRegion region = allRegions[i];
+ uint8_t highByte = region.address >> 28;
+ if ( (highByte == 9) || (highByte == 0xA) ) {
+ _shared_region_range_np splitRegion;
+ splitRegion.address = region.address;
+ splitRegion.size = region.size;
+ splitSegRegions.push_back(splitRegion);
+ }
+ }
+ int result = _shared_region_make_private_np(splitSegRegions.size(), &splitSegRegions[0]);
+ // 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 = fSegments.size();
+ 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
+ }
+ if ( context.verboseMapping ) {
+ fprintf(stderr, "dyld: Mapping split-seg shared %s\n", this->getPath());
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = fSegments[segIndex];
+ const _shared_region_mapping_np* entry = &mappingTable[entryIndex];
+ if ( (entry->init_prot & VM_PROT_ZF) == 0 )
+ fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), seg->getActualLoadAddress(), seg->getActualLoadAddress()+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;
+ fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), (uintptr_t)(seg->getActualLoadAddress() + segOffset), (uintptr_t)(seg->getActualLoadAddress() + segOffset + nextEntry->size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+ }
+ return r;
+}
+
+int
+ImageLoaderMachO::sharedRegionMapFilePrivate(int fd,
+ uint64_t offsetInFat,
+ uint64_t lenInFat,
+ uint64_t fileLen,
+ const LinkContext& context)
+{
+ const unsigned int segmentCount = fSegments.size();
+
+ // adjust base address of segments to pack next to last dylib
+ if ( context.slideAndPackDylibs ) {
+ uintptr_t lowestReadOnly = (uintptr_t)(-1);
+ uintptr_t lowestWritable = (uintptr_t)(-1);
+ for(unsigned int segIndex=0; segIndex < segmentCount; ++segIndex){
+ Segment* seg = fSegments[segIndex];
+ uintptr_t segEnd = seg->getActualLoadAddress();
+ if ( seg->writeable() ) {
+ if ( segEnd < lowestWritable )
+ lowestWritable = segEnd;
+ }
+ else {
+ if ( segEnd < lowestReadOnly )
+ lowestReadOnly = segEnd;
+ }
+ }
+ uintptr_t baseAddress;
+ if ( lowestWritable - 256*1024*1024 < lowestReadOnly )
+ baseAddress = lowestWritable - 256*1024*1024;
+ else
+ baseAddress = lowestReadOnly;
+ // record that we want dylb slid to fgNextSplitSegAddress
+ this->setSlide(fgNextSplitSegAddress - baseAddress);
+ }
+
+ // 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 = _shared_region_map_file_np(fd, mappingTableCount, mappingTable, context.slideAndPackDylibs ? NULL : &slide);
+ if ( 0 == r ) {
+ if ( 0 != slide ) {
+ slide = (slide) & (-4096); // round down to page boundary
+ this->setSlide(slide);
+ }
+ if ( context.verboseMapping ) {
+ if ( slide == 0 )
+ fprintf(stderr, "dyld: Mapping split-seg un-shared %s\n", this->getPath());
+ else
+ fprintf(stderr, "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 = fSegments[segIndex];
+ const _shared_region_mapping_np* entry = &mappingTable[entryIndex];
+ if ( (entry->init_prot & VM_PROT_ZF) == 0 )
+ fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), seg->getActualLoadAddress(), seg->getActualLoadAddress()+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;
+ fprintf(stderr, "%18s at 0x%08lX->0x%08lX (zerofill)\n",
+ seg->getName(), (uintptr_t)(seg->getActualLoadAddress() + segOffset), (uintptr_t)(seg->getActualLoadAddress() + segOffset + nextEntry->size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+ if ( context.slideAndPackDylibs ) {
+ // calculate where next split-seg dylib can load
+ uintptr_t largestReadOnly = 0;
+ uintptr_t largestWritable = 0;
+ for (unsigned int segIndex=0; segIndex < segmentCount; ++segIndex) {
+ Segment* seg = fSegments[segIndex];
+ uintptr_t segEnd = seg->getActualLoadAddress()+seg->getSize();
+ segEnd = (segEnd+4095) & (-4096); // page align
+ if ( seg->writeable() ) {
+ if ( segEnd > largestWritable )
+ largestWritable = segEnd;
+ }
+ else {
+ if ( segEnd > largestReadOnly )
+ largestReadOnly = segEnd;
+ }
+ }
+ if ( largestWritable - 256*1024*1024 > largestReadOnly )
+ fgNextSplitSegAddress = largestWritable - 256*1024*1024;
+ else
+ fgNextSplitSegAddress = largestReadOnly;
+ }
+ }
+ if ( context.slideAndPackDylibs && (r != 0) )
+ throw "can't rebase split-seg dylib";
+
+ return r;
+}
+
+
+int
+ImageLoaderMachO::sharedRegionLoadFile(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
+{
+
+ // map in split segment file at random address, then tell kernel to share it
+ void* loadAddress = 0;
+ loadAddress = mmap(NULL, fileLen, PROT_READ, MAP_FILE, fd, 0);
+ if ( loadAddress == ((void*)(-1)) )
+ throw "mmap error";
+
+ // calculate mapping entries
+ const unsigned int segmentCount = fSegments.size();
+ unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
+
+ // build table of segments to map
+ const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
+ const uintptr_t baseAddress = fSegments[0]->getPreferredLoadAddress();
+ sf_mapping mappingTable[mappingTableCount];
+ initMappingTable(offsetInFat, mappingTable, baseAddress);
+
+
+ // use load_shared_file() to map all segments at once
+ int flags = 0; // might need to set NEW_LOCAL_SHARED_REGIONS on first use
+ static bool firstTime = true;
+ if ( firstTime ) {
+ // when NEW_LOCAL_SHARED_REGIONS bit is set, this process will get is own shared region
+ // this is used by Xcode to prevent development libraries from polluting the global shared segment
+ if ( context.sharedRegionMode == kUsePrivateSharedRegion )
+ flags |= NEW_LOCAL_SHARED_REGIONS;
+ firstTime = false;
+ }
+
+ caddr_t base_address = (caddr_t)baseAddress;
+ kern_return_t r;
+ r = load_shared_file( (char*)fPath, // path of file to map shared
+ (char*)loadAddress, // beginning of local copy of sharable pages in file
+ fileLen, // end of shareable pages in file
+ &base_address, // beginning of address range to map
+ mappingTableCount, // number of entres in array of sf_mapping
+ mappingTable, // the array of sf_mapping
+ &flags); // in/out flags
+ if ( 0 != r ) {
+ // try again but tell kernel it is ok to slide
+ flags |= ALTERNATE_LOAD_SITE;
+ r = load_shared_file((char*)fPath,(char*)loadAddress, fileLen, &base_address,
+ mappingTableCount, mappingTable, &flags);
+ }
+
+ // unmap file from random address now that they are (hopefully) mapped into the shared region
+ munmap(loadAddress, fileLen);
+
+ if ( 0 == r ) {
+ if ( base_address != (caddr_t)baseAddress )
+ this->setSlide((uintptr_t)base_address - baseAddress);
+ if ( context.verboseMapping ) {
+ if ( base_address != (caddr_t)baseAddress )
+ fprintf(stderr, "dyld: Mapping split-seg load_shared_alt_region %s\n", this->getPath());
+ else
+ fprintf(stderr, "dyld: Mapping split-seg load_shared %s\n", this->getPath());
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = fSegments[segIndex];
+ const sf_mapping* entry = &mappingTable[entryIndex];
+ if ( (entry->protection & VM_PROT_ZF) == 0 )
+ fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), seg->getActualLoadAddress(), seg->getActualLoadAddress()+seg->getFileSize()-1);
+ if ( entryIndex < (mappingTableCount-1) ) {
+ const sf_mapping* nextEntry = &mappingTable[entryIndex+1];
+ if ( (nextEntry->protection & VM_PROT_ZF) != 0 ) {
+ fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
+ seg->getName(), (uintptr_t)(nextEntry->mapping_offset + base_address), (uintptr_t)(nextEntry->mapping_offset + base_address + nextEntry->size - 1));
+ ++entryIndex;
+ }
+ }
+ }
+ }
+ }
+ return r;
+}
+void
+ImageLoaderMachO::initMappingTable(uint64_t offsetInFat,
+ sf_mapping *mappingTable,
+ uintptr_t baseAddress)
+{
+ unsigned int segmentCount = fSegments.size();
+ for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
+ Segment* seg = fSegments[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 // !__LP64__ split segs not supported for 64-bits
+
+
+void ImageLoaderMachO::setSlide(intptr_t slide)
+{
+ fSlide = slide;
+}
+
+void ImageLoaderMachO::parseLoadCmds()
+{
+ // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
+ const unsigned int segmentCount = fSegments.size();
+ for(unsigned int i=0; i < segmentCount; ++i){
+ Segment* seg = fSegments[i];
+ // set up pointer to __LINKEDIT segment
+ if ( strcmp(seg->getName(),"__LINKEDIT") == 0 )
+ fLinkEditBase = (uint8_t*)(seg->getActualLoadAddress() - seg->getFileOffset());
+ // __TEXT segment always starts at beginning of file and contains mach_header and load commands
+ if ( strcmp(seg->getName(),"__TEXT") == 0 ) {
+ if ( seg->hasFixUps() )
+ fTextSegmentWithFixups = (SegmentMachO*)seg;
+ }
+ // 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());
+ }
+ }
+
+ // 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:
+ {
+ const struct sub_framework_command* subf = (struct sub_framework_command*)cmd;
+ fReExportThruFramework = (char*)cmd + subf->umbrella.offset;
+ }
+ break;
+ case LC_SUB_LIBRARY:
+ fHasSubLibraries = true;
+ break;
+ case LC_ROUTINES_COMMAND:
+ fDashInit = (struct macho_routines_command*)cmd;
+ break;
+ case LC_SEGMENT_COMMAND:
+ {
+ const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ const bool isDataSeg = (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) {
+ const uint8_t type = sect->flags & SECTION_TYPE;
+ if ( type == S_MOD_INIT_FUNC_POINTERS )
+ fModInitSection = sect;
+ else if ( type == S_MOD_TERM_FUNC_POINTERS )
+ fModTermSection = sect;
+ else if ( isDataSeg && (strcmp(sect->sectname, "__dyld") == 0) )
+ fDATAdyld = sect;
+ else if ( isDataSeg && (strcmp(sect->sectname, "__image_notify") == 0) )
+ fImageNotifySection = sect;
+ }
+ }
+ break;
+ case LC_TWOLEVEL_HINTS:
+ fTwoLevelHints = (struct twolevel_hints_command*)cmd;
+ break;
+ case LC_ID_DYLIB:
+ {
+ fDylibID = (struct dylib_command*)cmd;
+ }
+ break;
+ }
+ 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 ( fReExportThruFramework != NULL ) {
+ // 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], fReExportThruFramework) == 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(fReExportThruFramework)+1];
+ strcpy(reexportAndSuffix, fReExportThruFramework);
+ strcat(reexportAndSuffix, context.imageSuffix);
+ if ( strcmp(&lastSlash[1], reexportAndSuffix) == 0 )
+ return true;
+ }
+ }
+ }
+ }
+ 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;
+ #elif __ppc64__
+ const ppc_thread_state64_t* registers = (ppc_thread_state64_t*)(((char*)cmd) + 16);
+ return (void*)registers->srr0;
+ #elif __i386__
+ const i386_thread_state_t* registers = (i386_thread_state_t*)(((char*)cmd) + 16);
+ return (void*)registers->eip;
+ #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:
+ ++count;
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ return count;
+}
+
+void ImageLoaderMachO::doGetDependentLibraries(DependentLibrary 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:
+ {
+ const struct dylib_command* dylib = (struct dylib_command*)cmd;
+ DependentLibrary* lib = &libs[index++];
+ lib->name = (char*)cmd + dylib->dylib.name.offset;
+ //lib->name = strdup((char*)cmd + dylib->dylib.name.offset);
+ lib->image = NULL;
+ 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_DYLIB);
+ lib->checksumMatches = false;
+ lib->isReExported = false;
+ }
+ 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;
+}
+
+
+uintptr_t ImageLoaderMachO::getRelocBase()
+{
+ if ( fIsSplitSeg ) {
+ // in split segment libraries r_address is offset from first writable segment
+ const unsigned int segmentCount = fSegments.size();
+ for(unsigned int i=0; i < segmentCount; ++i){
+ Segment* seg = fSegments[i];
+ if ( seg->writeable() ) {
+ return seg->getActualLoadAddress();
+ }
+ }
+ }
+
+ // in non-split segment libraries r_address is offset from first segment
+ return fSegments[0]->getActualLoadAddress();
+}
+
+#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);
+ //fprintf(stderr, "dyld: ppc fixup %0p type %d from 0x%08X to 0x%08X\n", locationToFix, relocationType, before, after);
+}
+#endif
+
+void ImageLoaderMachO::doRebase(const LinkContext& context)
+{
+ // if prebound and loaded at prebound address, then no need to rebase
+ // Note: you might think that the check for allDependentLibrariesAsWhenPreBound() is not needed
+ // but it is. If a dependent library changed, this image's lazy pointers into that library
+ // need to be updated (reset back to lazy binding handler). That work is done most easily
+ // here because there is a PPC_RELOC_PB_LA_PTR reloc record for each lazy pointer.
+ if ( this->usablePrebinding(context) && this->usesTwoLevelNameSpace() ) {
+ // skip rebasing cause prebound and prebinding not disabled
+ ++fgImagesWithUsedPrebinding; // bump totals for statistics
+ return;
+ }
+
+ // print why prebinding was not used
+ if ( context.verbosePrebinding ) {
+ if ( !this->isPrebindable() ) {
+ fprintf(stderr, "dyld: image not prebound, so could not use prebinding in %s\n", this->getPath());
+ }
+ else if ( fSlide != 0 ) {
+ fprintf(stderr, "dyld: image slid, so could not use prebinding in %s\n", this->getPath());
+ }
+ else if ( !this->allDependentLibrariesAsWhenPreBound() ) {
+ fprintf(stderr, "dyld: dependent libraries changed, so could not use prebinding in %s\n", this->getPath());
+ }
+ else if ( !this->usesTwoLevelNameSpace() ){
+ fprintf(stderr, "dyld: image uses flat-namespace so, parts of prebinding ignored %s\n", this->getPath());
+ }
+ else {
+ fprintf(stderr, "dyld: environment variable disabled use of prebinding in %s\n", this->getPath());
+ }
+ }
+
+ // if there are __TEXT fixups, temporarily make __TEXT writable
+ if ( fTextSegmentWithFixups != NULL )
+ fTextSegmentWithFixups->tempWritable();
+
+ // cache this value that is used in the following loop
+ register const uintptr_t slide = this->fSlide;
+
+ // loop through all local (internal) relocation records
+ const uintptr_t relocBase = this->getRelocBase();
+ 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 ) {
+ 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__ || __ppc64__
+ case PPC_RELOC_PB_LA_PTR:
+ // should only see these in prebound images, and we got here so prebinding is being ignored
+ *locationToFix = sreloc->r_value + slide;
+ break;
+ #endif
+ #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;
+ #endif
+ #if __i386__
+ case GENERIC_RELOC_PB_LA_PTR:
+ // should only see these in prebound images, and we got here so prebinding is being ignored
+ *locationToFix = sreloc->r_value + slide;
+ break;
+ #endif
+ default:
+ throw "unknown local scattered relocation type";
+ }
+ }
+ else {
+ throw "bad local scattered relocation length";
+ }
+ }
+ }
+
+ // if there were __TEXT fixups, restore write protection
+ if ( fTextSegmentWithFixups != NULL ) {
+ fTextSegmentWithFixups->setPermissions();
+ sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(), fTextSegmentWithFixups->getSize());
+ }
+
+ // 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)
+{
+ 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;
+ }
+
+ 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)
+{
+ ++ImageLoaderMachO::fgUnhintedBinaryTreeSearchs;
+ 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, 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
+{
+ const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
+ return nlistSym->n_value + fSlide;
+}
+
+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)
+{
+ const char* formatString = "Symbol not found: %s\n Referenced from: %s\n Expected in: %s\n";
+ char buf[strlen(symbol)+strlen(referencedFrom)+strlen(expectedIn)+strlen(formatString)];
+ sprintf(buf, formatString, symbol, referencedFrom, expectedIn);
+ throw strdup(buf); // this is a leak if exception doesn't halt program
+}
+
+uintptr_t ImageLoaderMachO::resolveUndefined(const LinkContext& context, const struct macho_nlist* undefinedSymbol, bool twoLevel, ImageLoader** foundIn)
+{
+ const char* symbolName = &fStrings[undefinedSymbol->n_un.n_strx];
+
+ if ( context.bindFlat || !twoLevel ) {
+ // flat lookup
+ const Symbol* sym;
+ if ( context.flatExportFinder(symbolName, &sym, foundIn) )
+ return (*foundIn)->getExportedSymbolAddress(sym);
+ // 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);
+ }
+ if ( ((undefinedSymbol->n_type & N_PEXT) != 0) || ((undefinedSymbol->n_type & N_TYPE) == N_SECT) ) {
+ // could be a multi-module private_extern internal reference
+ // the static linker squirrels away the target address in n_value
+ uintptr_t addr = undefinedSymbol->n_value + this->fSlide;
+ *foundIn = this;
+ return addr;
+ }
+ 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
+ if ( this->needsCoalescing() && symbolRequiresCoalescing(undefinedSymbol) ) {
+ const Symbol* sym;
+ if ( context.coalescedExportFinder(symbolName, &sym, foundIn) )
+ return (*foundIn)->getExportedSymbolAddress(sym);
+ //throwSymbolNotFound(symbolName, this->getPath(), "coalesced namespace");
+ //fprintf(stderr, "dyld: coalesced symbol %s not found in any coalesced image, falling back to two-level lookup", symbolName);
+ }
+
+ // 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);
+ // 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);
+
+ 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 {
+ throw "corrupt binary, library ordinal too big";
+ }
+
+ if ( target == NULL ) {
+ fprintf(stderr, "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);
+ }
+ 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 undefinedSymbol->n_value + fSlide;
+ }
+ 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());
+ }
+}
+
+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 there are __TEXT fixups, temporarily make __TEXT writable
+ if ( fTextSegmentWithFixups != NULL )
+ fTextSegmentWithFixups->tempWritable();
+
+ // cache last lookup
+ const struct macho_nlist* lastUndefinedSymbol = 0;
+ uintptr_t symbolAddr = 0;
+ 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 GENERIC_RELOC_VANILLA:
+ {
+ 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;
+ if ( prebound ) {
+ // we are doing relocations, so prebinding was not usable
+ // in a prebound executable, the n_value field 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 would not be necessary.
+ 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;
+ }
+ if ( context.verboseBind ) {
+ const char *path = NULL;
+ if(NULL != image) {
+ path = image->getShortName();
+ }
+ if(0 == value) {
+ fprintf(stderr, "dyld: bind: %s:0x%08lx = %s:%s, *0x%08lx = 0x%08lx\n",
+ this->getShortName(), (uintptr_t)location,
+ path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr);
+ }
+ else {
+ fprintf(stderr, "dyld: bind: %s:0x%08lx = %s:%s, *0x%08lx = 0x%08lx + %ld\n",
+ this->getShortName(), (uintptr_t)location,
+ path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr, value);
+ }
+ }
+ value += symbolAddr;
+ *location = value;
+ }
+ break;
+ default:
+ throw "unknown external relocation type";
+ }
+ }
+ else {
+ throw "bad external relocation length";
+ }
+ }
+
+ // if there were __TEXT fixups, restore write protection
+ if ( fTextSegmentWithFixups != NULL ) {
+ fTextSegmentWithFixups->setPermissions();
+ sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(), fTextSegmentWithFixups->getSize());
+ }
+
+ // update stats
+ fgTotalBindFixups += fDynamicInfo->nextrel;
+}
+
+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::getBaseAddress() const
+{
+ Segment* seg = fSegments[0];
+ return (const void*)seg->getActualLoadAddress();
+}
+
+
+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;
+ 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;
+ uint32_t symbolIndex = indirectTable[indirectTableOffset + lazyIndex];
+ if ( symbolIndex != INDIRECT_SYMBOL_ABS && symbolIndex != INDIRECT_SYMBOL_LOCAL ) {
+ ImageLoader *image = NULL;
+ const char *path = NULL;
+ uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], twoLevel, &image);
+ if ( context.verboseBind ) {
+ if(NULL == path && NULL != image) {
+ path = image->getShortName();
+ }
+ fprintf(stderr, "dyld: bind: %s:%s$%s = %s:%s, *0x%08lx = 0x%08lx\n",
+ this->getShortName(), &fStrings[fSymbolTable[symbolIndex].n_un.n_strx], "lazy_ptr",
+ path, &fStrings[fSymbolTable[symbolIndex].n_un.n_strx], (uintptr_t)&symbolPointers[lazyIndex], symbolAddr);
+ }
+ if ( NULL != context.bindingHandler ) {
+ if(NULL == path && NULL != image) {
+ path = image->getPath();
+ }
+ symbolAddr = (uintptr_t)context.bindingHandler(path, &fStrings[fSymbolTable[symbolIndex].n_un.n_strx], (void *)symbolAddr);
+ }
+ symbolPointers[lazyIndex] = symbolAddr;
+ // update stats
+ fgTotalLazyBindFixups++;
+ return symbolPointers[lazyIndex];
+ }
+ }
+ }
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+ throw "lazy pointer not found";
+}
+
+
+
+void ImageLoaderMachO::doBindIndirectSymbolPointers(const LinkContext& context, BindingLaziness bindness, bool onlyCoalescedSymbols)
+{
+ // 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;
+ const uint32_t pointerCount = sect->size / sizeof(uintptr_t);
+ if ( type == S_NON_LAZY_SYMBOL_POINTERS ) {
+ if ( (bindness == kLazyOnly) || (bindness == kLazyOnlyNoDependents) )
+ continue;
+ }
+ else if ( type == S_LAZY_SYMBOL_POINTERS ) {
+ // process each symbol pointer in this section
+ fgTotalPossibleLazyBindFixups += pointerCount;
+ if ( bindness == kNonLazyOnly )
+ continue;
+ }
+ else {
+ continue;
+ }
+ const uint32_t indirectTableOffset = sect->reserved1;
+ uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
+ for (uint32_t j=0; j < pointerCount; ++j) {
+ uint32_t symbolIndex = indirectTable[indirectTableOffset + j];
+ if ( symbolIndex == INDIRECT_SYMBOL_LOCAL) {
+ symbolPointers[j] += 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 ) {
+ fprintf(stderr, "dyld: malformed executable '%s', skipping indirect symbol to %s\n",
+ this->getPath(), &fStrings[sym->n_un.n_strx]);
+ alreadyWarned = true;
+ }
+ continue;
+ }
+ }
+ }
+ 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);
+ if ( context.verboseBind ) {
+ const char *path = NULL;
+ if(NULL != image) {
+ path = image->getShortName();
+ }
+ const char *typeName;
+ if ( type == S_LAZY_SYMBOL_POINTERS ) {
+ typeName = "lazy_ptr";
+ }
+ else {
+ typeName = "non_lazy_ptr";
+ }
+ fprintf(stderr, "dyld: bind: %s:%s$%s = %s:%s, *0x%08lx = 0x%08lx\n",
+ this->getShortName(), &fStrings[sym->n_un.n_strx], typeName,
+ path, &fStrings[sym->n_un.n_strx], (uintptr_t)&symbolPointers[j], symbolAddr);
+ }
+ symbolPointers[j] = symbolAddr;
+ }
+ }
+ // update stats
+ fgTotalBindFixups += pointerCount;
+ }
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+
+/*
+ * The address of these symbols are written in to the (__DATA,__dyld) section
+ * at the following offsets:
+ * at offset 0 stub_binding_helper_interface
+ * at offset 4 _dyld_func_lookup
+ * at offset 8 start_debug_thread
+ * The 'C' types (if any) for these symbols are ignored here and all are
+ * declared as longs so the assignment of their address in to the section will
+ * not require a cast. stub_binding_helper_interface is really a label in the
+ * assembly code interface for the stub binding. It does not have a meaningful
+ * 'C' type. _dyld_func_lookup is the routine in dyld_libfuncs.c.
+ * start_debug_thread is the routine in debug.c.
+ *
+ * For ppc the image's stub_binding_binding_helper is read from:
+ * at offset 20 the image's stub_binding_binding_helper address
+ * and saved into to the image structure.
+ */
+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
+ void* startDebugThread; // debugger interface ???
+ void* debugPort; // debugger interface ???
+ void* debugThread; // debugger interface ???
+ void* stubBindHelper; // filled in at static link time to point to stub helper in image
+ void* coreDebug; // ???
+};
+
+// These are defined in dyldStartup.s
+extern "C" void stub_binding_helper();
+extern "C" bool dyld_func_lookup(const char* name, uintptr_t* address);
+
+
+void ImageLoaderMachO::setupLazyPointerHandler()
+{
+ if ( fDATAdyld != NULL ) {
+ struct DATAdyld* dd = (struct DATAdyld*)(fDATAdyld->addr + fSlide);
+ if ( fDATAdyld->size > offsetof(DATAdyld, dyldLazyBinder) ) {
+ if ( dd->dyldLazyBinder != (void*)&stub_binding_helper )
+ dd->dyldLazyBinder = (void*)&stub_binding_helper;
+ }
+ if ( fDATAdyld->size > offsetof(DATAdyld, dyldFuncLookup) ) {
+ if ( dd->dyldFuncLookup != (void*)&dyld_func_lookup )
+ dd->dyldFuncLookup = (void*)&dyld_func_lookup;
+ }
+ //if ( fDATAdyld->size > offsetof(DATAdyld, startDebugThread) )
+ // dd->startDebugThread = &start_debug_thread;
+#ifdef __ppc__
+ //if ( fDATAdyld->size > offsetof(DATAdyld, stubBindHelper) )
+ // save = dd->stubBindHelper;
+#endif
+ }
+}
+
+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() && this->allDependentLibrariesAsWhenPreBound() && (this->getSlide() == 0) ) {
+ // 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::doBind(const LinkContext& context, BindingLaziness bindness)
+{
+ // set dyld entry points in image
+ this->setupLazyPointerHandler();
+
+ // 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 be imports rebound (even if correctly prebound)
+ if ( this->usablePrebinding(context) && this->usesTwoLevelNameSpace() ) {
+ // if image has coalesced symbols, then these need to be rebound
+ if ( this->needsCoalescing() ) {
+ this->doBindExternalRelocations(context, true);
+ this->doBindIndirectSymbolPointers(context, kLazyAndNonLazy, true);
+ }
+ // skip binding because prebound and prebinding not disabled
+ return;
+ }
+
+ // values bound by name are stored two different ways in mach-o
+ switch (bindness) {
+ case kNonLazyOnly:
+ case kLazyAndNonLazy:
+ // external relocations are used for data initialized to external symbols
+ this->doBindExternalRelocations(context, false);
+ break;
+ case kLazyOnly:
+ case kLazyOnlyNoDependents:
+ break;
+ }
+ // "indirect symbols" are used for code references to external symbols
+ this->doBindIndirectSymbolPointers(context, bindness, false);
+}
+
+
+
+void ImageLoaderMachO::doImageInit(const LinkContext& context)
+{
+ if ( fDashInit != NULL ) {
+ Initializer func = (Initializer)(fDashInit->init_address + fSlide);
+ if ( context.verboseInit )
+ fprintf(stderr, "dyld: calling -init function 0x%p in %s\n", func, this->getPath());
+ func(context.argc, context.argv, context.envp, context.apple);
+ }
+}
+
+void ImageLoaderMachO::doModInitFunctions(const LinkContext& context)
+{
+ if ( fModInitSection != NULL ) {
+ Initializer* inits = (Initializer*)(fModInitSection->addr + fSlide);
+ const uint32_t count = fModInitSection->size / sizeof(uintptr_t);
+ for (uint32_t i=0; i < count; ++i) {
+ Initializer func = inits[i];
+ if ( context.verboseInit )
+ fprintf(stderr, "dyld: calling initializer function %p in %s\n", func, this->getPath());
+ func(context.argc, context.argv, context.envp, context.apple);
+ }
+ }
+}
+
+
+void ImageLoaderMachO::doInitialization(const LinkContext& context)
+{
+ // mach-o has -init and static initializers
+ doImageInit(context);
+ doModInitFunctions(context);
+}
+
+bool ImageLoaderMachO::needsInitialization()
+{
+ return ( (fDashInit != NULL) || (fModInitSection != NULL) );
+}
+
+
+bool ImageLoaderMachO::needsTermination()
+{
+ return ( fModTermSection != NULL );
+}
+
+bool ImageLoaderMachO::hasImageNotification()
+{
+ return ( fImageNotifySection != NULL );
+}
+
+
+void ImageLoaderMachO::doTermination(const LinkContext& context)
+{
+ if ( fModTermSection != NULL ) {
+ Terminator* terms = (Terminator*)(fModTermSection->addr + fSlide);
+ const uint32_t count = fModTermSection->size / sizeof(uintptr_t);
+ for (uint32_t i=count; i > 0; --i) {
+ Terminator func = terms[i-1];
+ if ( context.verboseInit )
+ fprintf(stderr, "dyld: calling terminaton function %p in %s\n", func, this->getPath());
+ func();
+ }
+ }
+}
+
+void ImageLoaderMachO::doNotification(enum dyld_image_mode mode, uint32_t infoCount, const struct dyld_image_info info[])
+{
+ if ( fImageNotifySection != NULL ) {
+ dyld_image_notifier* notes = (dyld_image_notifier*)(fImageNotifySection->addr + fSlide);
+ const uint32_t count = fImageNotifySection->size / sizeof(uintptr_t);
+ for (uint32_t i=count; i > 0; --i) {
+ dyld_image_notifier func = notes[i-1];
+ func(mode, infoCount, info);
+ }
+ }
+}
+
+void ImageLoaderMachO::printStatistics(unsigned int imageCount)
+{
+ ImageLoader::printStatistics(imageCount);
+ fprintf(stderr, "total hinted binary tree searches: %d\n", fgHintedBinaryTreeSearchs);
+ fprintf(stderr, "total unhinted binary tree searches: %d\n", fgUnhintedBinaryTreeSearchs);
+
+#if LINKEDIT_USAGE_DEBUG
+ fprintf(stderr, "linkedit pages accessed (%lu):\n", sLinkEditPageBuckets.size());
+#endif
+}
+
+void ImageLoaderMachO::doPrebinding(const LinkContext& context, time_t timestamp, uint8_t* fileToPrebind)
+{
+ // update __DATA segment
+ this->applyPrebindingToDATA(fileToPrebind);
+
+ // update load commands
+ this->applyPrebindingToLoadCommands(context, fileToPrebind, timestamp);
+
+ // update symbol table
+ this->applyPrebindingToLinkEdit(context, fileToPrebind);
+}
+
+void ImageLoaderMachO::applyPrebindingToDATA(uint8_t* fileToPrebind)
+{
+ const unsigned int segmentCount = fSegments.size();
+ for(unsigned int i=0; i < segmentCount; ++i) {
+ SegmentMachO* seg = (SegmentMachO*)fSegments[i];
+ if ( seg->writeable() ) {
+ memcpy(&fileToPrebind[seg->fFileOffset], (void*)seg->getActualLoadAddress(), seg->fFileSize);
+ }
+ }
+}
+
+void ImageLoaderMachO::applyPrebindingToLoadCommands(const LinkContext& context, uint8_t* fileToPrebind, time_t timestamp)
+{
+ macho_header* mh = (macho_header*)fileToPrebind;
+ const uint32_t cmd_count = mh->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fileToPrebind[sizeof(macho_header)];
+ const struct load_command* cmd = cmds;
+ for (uint32_t i = 0; i < cmd_count; ++i) {
+ switch (cmd->cmd) {
+ case LC_LOAD_DYLIB:
+ case LC_LOAD_WEAK_DYLIB:
+ {
+ // update each dylib load command with the timestamp of the target dylib
+ struct dylib_command* dylib = (struct dylib_command*)cmd;
+ const char* name = (char*)cmd + dylib->dylib.name.offset;
+ for (const DependentLibrary* dl=fLibraries; dl < &fLibraries[fLibrariesCount]; dl++) {
+ if (strcmp(dl->name, name) == 0 ) {
+ // found matching DependentLibrary for this load command
+ ImageLoaderMachO* targetImage = (ImageLoaderMachO*)(dl->image); // !!! assume only mach-o images are prebound
+ if ( ! targetImage->isPrebindable() )
+ throw "dependent dylib is not prebound";
+ // if the target is currently being re-prebound then its timestamp will be the same as this one
+ if ( ! targetImage->usablePrebinding(context) ) {
+ dylib->dylib.timestamp = timestamp;
+ }
+ else {
+ // otherwise dependent library is already correctly prebound, so use its checksum
+ dylib->dylib.timestamp = targetImage->doGetLibraryInfo().checksum;
+ }
+ break;
+ }
+ }
+ }
+ break;
+ case LC_ID_DYLIB:
+ {
+ // update the ID of this library with the new timestamp
+ struct dylib_command* dylib = (struct dylib_command*)cmd;
+ dylib->dylib.timestamp = timestamp;
+ }
+ break;
+ case LC_SEGMENT_COMMAND:
+ // if dylib was rebased, update segment commands
+ if ( fSlide != 0 ) {
+ struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+ seg->vmaddr += fSlide;
+ struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+ struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
+ for (struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ sect->addr += fSlide;
+ }
+ }
+ break;
+ case LC_ROUTINES_COMMAND:
+ // if dylib was rebased, update -init command
+ if ( fSlide != 0 ) {
+ struct macho_routines_command* routines = (struct macho_routines_command*)cmd;
+ routines->init_address += fSlide;
+ }
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+}
+
+void ImageLoaderMachO::applyPrebindingToLinkEdit(const LinkContext& context, uint8_t* fileToPrebind)
+{
+ // In prebound images, the n_value of the symbol table entry for is the prebound address
+ // This is needed when prebinding can't be used, to back solve for any possible addend in non-lazy pointers
+ const char* stringPool = NULL;
+ struct macho_nlist* symbolTable = NULL;
+ const struct dysymtab_command* dysymtab = NULL;
+
+ // get symbol table info
+ macho_header* mh = (macho_header*)fileToPrebind;
+ const uint32_t cmd_count = mh->ncmds;
+ const struct load_command* const cmds = (struct load_command*)&fileToPrebind[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;
+ stringPool = (const char*)&fileToPrebind[symtab->stroff];
+ symbolTable = (struct macho_nlist*)(&fileToPrebind[symtab->symoff]);
+ }
+ break;
+ case LC_DYSYMTAB:
+ dysymtab = (struct dysymtab_command*)cmd;
+ break;
+ }
+ cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+ }
+
+ // walk all imports and re-resolve their n_value (needed incase prebinding is invalid)
+ struct macho_nlist* lastImport = &symbolTable[dysymtab->iundefsym+dysymtab->nundefsym];
+ for (struct macho_nlist* entry = &symbolTable[dysymtab->iundefsym]; entry < lastImport; ++entry) {
+ ImageLoader* dummy;
+ entry->n_value = this->resolveUndefined(context, entry, this->usesTwoLevelNameSpace(), &dummy);
+ }
+
+ // walk all exports and slide their n_value
+ struct macho_nlist* lastExport = &symbolTable[dysymtab->iextdefsym+dysymtab->nextdefsym];
+ for (struct macho_nlist* entry = &symbolTable[dysymtab->iextdefsym]; entry < lastExport; ++entry) {
+ entry->n_value += fSlide;
+ }
+
+ // walk all local symbols and slide their n_value
+ struct macho_nlist* lastLocal = &symbolTable[dysymtab->ilocalsym+dysymtab->nlocalsym];
+ for (struct macho_nlist* entry = &symbolTable[dysymtab->ilocalsym]; entry < lastLocal; ++entry) {
+ if ( (entry->n_type & N_TYPE) == N_SECT )
+ entry->n_value += fSlide;
+ }
+
+ // walk all local relocations and reset every PPC_RELOC_PB_LA_PTR r_value
+ relocation_info* const relocsStart = (struct relocation_info*)(&fileToPrebind[dysymtab->locreloff]);
+ relocation_info* const relocsEnd = &relocsStart[dysymtab->nlocrel];
+ for (relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+ if ( (reloc->r_address & R_SCATTERED) != 0 ) {
+ struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
+ if (sreloc->r_length == RELOC_SIZE) {
+ switch(sreloc->r_type) {
+ #if __ppc__ || __ppc64__
+ case PPC_RELOC_PB_LA_PTR:
+ #elif __i386__
+ case GENERIC_RELOC_PB_LA_PTR:
+ #else
+ #error unknown architecture
+ #endif
+ sreloc->r_value += fSlide;
+ break;
+ }
+ }
+ }
+ }
+
+}
+
+
+SegmentMachO::SegmentMachO(const struct macho_segment_command* cmd, ImageLoaderMachO* image, const uint8_t* fileData)
+ : fImage(image), fSize(cmd->vmsize), fFileSize(cmd->filesize), fFileOffset(cmd->fileoff), fPreferredLoadAddress(cmd->vmaddr),
+ fVMProtection(cmd->initprot), fHasFixUps(false), fUnMapOnDestruction(false)
+{
+ strncpy(fName, cmd->segname, 16);
+ fName[16] = '\0';
+ // scan sections for fix-up bit
+ const struct macho_section* const sectionsStart = (struct macho_section*)((char*)cmd + sizeof(struct macho_segment_command));
+ const struct macho_section* const sectionsEnd = §ionsStart[cmd->nsects];
+ for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+ if ( (sect->flags & (S_ATTR_EXT_RELOC | S_ATTR_LOC_RELOC)) != 0 )
+ fHasFixUps = true;
+ }
+}
+
+SegmentMachO::~SegmentMachO()
+{
+ if ( fUnMapOnDestruction ) {
+ //fprintf(stderr, "unmapping segment %s at 0x%08lX\n", getName(), getActualLoadAddress());
+ munmap((void*)(this->getActualLoadAddress()), this->getSize());
+ }
+}
+
+const ImageLoader* SegmentMachO::getImage()
+{
+ return fImage;
+}
+
+const char* SegmentMachO::getName()
+{
+ return fName;
+}
+
+uintptr_t SegmentMachO::getSize()
+{
+ return fSize;
+}
+
+uintptr_t SegmentMachO::getFileSize()
+{
+ return fFileSize;
+}
+
+uintptr_t SegmentMachO::getFileOffset()
+{
+ return fFileOffset;
+}
+
+bool SegmentMachO::readable()
+{
+ return ( (fVMProtection & VM_PROT_READ) != 0);
+}
+
+bool SegmentMachO::writeable()
+{
+ return ((fVMProtection & VM_PROT_WRITE) != 0);
+}
+
+bool SegmentMachO::executable()
+{
+ return ((fVMProtection & VM_PROT_EXECUTE) != 0);
+}
+
+bool SegmentMachO::unaccessible()
+{
+ return (fVMProtection == 0);
+}
+
+bool SegmentMachO::hasFixUps()
+{
+ return fHasFixUps;
+}
+
+uintptr_t SegmentMachO::getActualLoadAddress()
+{
+ return fPreferredLoadAddress + fImage->fSlide;
+}
+
+uintptr_t SegmentMachO::getPreferredLoadAddress()
+{
+ return fPreferredLoadAddress;
+}
+
+bool SegmentMachO::hasPreferredLoadAddress()
+{
+ return (fPreferredLoadAddress != 0);
+}
+
+void SegmentMachO::setUnMapWhenDestructed(bool unmap)
+{
+ fUnMapOnDestruction = unmap;
+}
+
+static uint32_t *buildCRCTable(void)
+{
+ uint32_t *table = new uint32_t[256];
+ uint32_t p = 0xedb88320UL; // standard CRC-32 polynomial
+
+ for (unsigned int i = 0; i < 256; i++) {
+ uint32_t c = i;
+ for (unsigned int j = 0; j < 8; j++) {
+ if ( c & 1 ) c = p ^ (c >> 1);
+ else c = c >> 1;
+ }
+ table[i] = c;
+ }
+
+ return table;
+}
+
+uint32_t SegmentMachO::crc32()
+{
+ if ( !readable() ) return 0;
+
+ static uint32_t *crcTable = NULL;
+ if ( !crcTable ) crcTable = buildCRCTable();
+
+ uint32_t crc = ~(uint32_t)0;
+ uint8_t *p = (uint8_t *)getActualLoadAddress();
+ uint8_t *end = p + getSize();
+ while ( p < end ) {
+ crc = crcTable[(crc & 0xff) ^ (*p++)] ^ (crc >> 8);
+ }
+ return crc ^ ~(uint32_t)0;
+}
+
+
+
+
+
projects / apple / dyld.git / commitdiff
