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--- dyld/dyld-45.3/src/ImageLoaderMachO.cpp
+++ /dev/null
@@ -1,2736 +0,0 @@
-/* -*- 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
-
-#ifndef S_ATTR_SELF_MODIFYING_CODE
- #define S_ATTR_SELF_MODIFYING_CODE 0x04000000
-#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
-
- #define POINTER_RELOC GENERIC_RELOC_VANILLA
-
-uint32_t ImageLoaderMachO::fgHintedBinaryTreeSearchs = 0;
-uint32_t ImageLoaderMachO::fgUnhintedBinaryTreeSearchs = 0;
-uint32_t ImageLoaderMachO::fgCountOfImagesWithWeakExports = 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();
-}
-
-ImageLoaderMachO::~ImageLoaderMachO()
-{
- // keep count of images with weak exports
- if ( this->hasCoalescedExports() )
- --fgCountOfImagesWithWeakExports;
-}
-
-
-
-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 ) {
- if ( (((struct macho_segment_command*)cmd)->vmsize != 0) || !fIsSplitSeg )
- 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 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;
- //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";
- }
- }
-
- 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;
-}
-
-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 )
- 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 ) {
- // 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,
- kSharedRegionMapFilePrivateMMapState,
- 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.slideAndPackDylibs ) {
- sharedRegionMakePrivate(context);
- // remove underlying submap and block out 0x90000000 to 0xAFFFFFFF
- vm_address_t addr = (vm_address_t)0x90000000;
- vm_deallocate(mach_task_self(), addr, 0x20000000);
- vm_allocate(mach_task_self(), &addr, 0x20000000, false);
- sSharedRegionState = kSharedRegionMapFilePrivateMMapState;
- }
- else if ( context.sharedRegionMode == kUsePrivateSharedRegion ) {
- 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) || (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";
- }
- }
-}
-
-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,
- bool usemmap)
-{
- 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;
- if ( usemmap )
- r = _shared_region_map_file_with_mmap(fd, mappingTableCount, mappingTable);
- else
- 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) )
- throwf("can't rebase split-seg dylib %s because shared_region_map_file_np() returned %d", this->getPath(), r);
-
- 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());
- }
- }
-
- // keep count of prebound images with weak exports
- if ( this->hasCoalescedExports() )
- ++fgCountOfImagesWithWeakExports;
-
- // 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;
- case LC_LOAD_WEAK_DYLIB:
- // do nothing, just prevent LC_REQ_DYLD exception from occuring
- break;
- default:
- if ( (cmd->cmd & LC_REQ_DYLD) != 0 )
- 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 ( 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::getFirstWritableSegmentAddress()
-{
- // in split segment libraries r_address is offset from first writable segment
- for (std::vector<class Segment*>::iterator it=fSegments.begin(); it != fSegments.end(); ++it) {
- if ( (*it)->writeable() ) {
- return (*it)->getActualLoadAddress();
- }
- }
- throw "no writable segment";
-}
-
-uintptr_t ImageLoaderMachO::getRelocBase()
-{
-#if __ppc__ || __i386__
- if ( fIsSplitSeg ) {
- // in split segment libraries r_address is offset from first writable segment
- return getFirstWritableSegmentAddress();
- }
-#endif
-
- // 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 __ppc__ || __ppc64__ || __i386__
- 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";
- }
- }
- #endif
- }
-
- // 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());
- }
-}
-
-// 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 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 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;
- #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;
- }
- 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;
- #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
- }
- 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::bindIndirectSymbol(uintptr_t* ptrToBind, const struct macho_section* sect, const char* symbolName, uintptr_t targetAddr, ImageLoader* targetImage, const LinkContext& context)
-{
- if ( context.verboseBind ) {
- const char* path = NULL;
- if ( targetImage != NULL )
- path = targetImage->getShortName();
- fprintf(stderr, "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) ) {
- uint8_t* const jmpTableEntryToPatch = (uint8_t*)ptrToBind;
- uint32_t rel32 = targetAddr - (((uint32_t)ptrToBind)+5);
- //fprintf(stderr, "rewriting stub at %p\n", jmpTableEntryToPatch);
- jmpTableEntryToPatch[0] = 0xE9; // JMP rel32
- jmpTableEntryToPatch[1] = rel32 & 0xFF;
- jmpTableEntryToPatch[2] = (rel32 >> 8) & 0xFF;
- jmpTableEntryToPatch[3] = (rel32 >> 16) & 0xFF;
- jmpTableEntryToPatch[4] = (rel32 >> 24) & 0xFF;
- }
- 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];
- ImageLoader* image = NULL;
- uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], twoLevel, &image);
- symbolAddr = this->bindIndirectSymbol(lazyPointer, sect, symbolName, symbolAddr, image, context);
- ++fgTotalLazyBindFixups;
- return symbolAddr;
- }
- }
- }
- 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;
- uint32_t elementSize = sizeof(uintptr_t);
- uint32_t elementCount = sect->size / elementSize;
- 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 += elementCount;
- if ( bindness == kNonLazyOnly )
- 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 ( bindness == kNonLazyOnly )
- 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) {
- 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 ) {
- 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);
-
- // update pointer
- symbolAddr = this->bindIndirectSymbol((uintptr_t*)ptrToBind, sect, &fStrings[sym->n_un.n_strx], symbolAddr, image, context);
- }
- }
- // update stats
- fgTotalBindFixups += elementCount;
- }
- }
- 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);
-extern "C" void fast_stub_binding_helper_interface();
-
-
-void ImageLoaderMachO::setupLazyPointerHandler(const LinkContext& context)
-{
- 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
- }
-#if __i386__
- if ( ! this->usablePrebinding(context) || !this->usesTwoLevelNameSpace() ) {
- // reset all "fast" stubs
- const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
- const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
- const struct load_command* cmd = cmds;
- for (uint32_t i = 0; i < cmd_count; ++i) {
- switch (cmd->cmd) {
- case LC_SEGMENT_COMMAND:
- {
- const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
- const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
- const struct macho_section* const sectionsEnd = §ionsStart[seg->nsects];
- for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
- const uint8_t type = sect->flags & SECTION_TYPE;
- if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
- // reset each jmp entry in this section
- 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;
- for (uint8_t* entry = start; entry < end; entry += 5) {
- uint32_t rel32 = dyldHandler - (((uint32_t)entry)+5);
- entry[0] = 0xE8; // CALL rel32
- entry[1] = rel32 & 0xFF;
- entry[2] = (rel32 >> 8) & 0xFF;
- entry[3] = (rel32 >> 16) & 0xFF;
- entry[4] = (rel32 >> 24) & 0xFF;
- }
- }
- }
- }
- }
- cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
- }
- }
-#endif
-}
-
-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(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 be imports rebound (even if correctly prebound)
- if ( this->usablePrebinding(context) && this->usesTwoLevelNameSpace() ) {
- // 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, 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);
- fprintf(stderr, "total images with weak exports: %d\n", fgCountOfImagesWithWeakExports);
-
-#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) {
- if ( (entry->n_type & N_TYPE) == N_SECT )
- 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_sect != NO_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;
- }
- }
- }
- }
-
- // if multi-module, fix up objc_addr (10.4 and later runtime does not use this, but we want to keep file checksum consistent)
- if ( dysymtab->nmodtab != 0 ) {
- dylib_module* const modulesStart = (struct dylib_module*)(&fileToPrebind[dysymtab->modtaboff]);
- dylib_module* const modulesEnd = &modulesStart[dysymtab->nmodtab];
- for (dylib_module* module=modulesStart; module < modulesEnd; ++module) {
- if ( module->objc_module_info_size != 0 ) {
- module->objc_module_info_addr += fSlide;
- }
- }
- }
-}
-
-// file on disk has been reprebound, but we are still mapped to old file
-void ImageLoaderMachO::prebindUnmap(const LinkContext& context)
-{
- // this removes all mappings to the old file, so the kernel will unlink (delete) it.
- // We need to leave the load commands and __LINKEDIT in place
- for (std::vector<class Segment*>::iterator it=fSegments.begin(); it != fSegments.end(); ++it) {
- void* segmentAddress = (void*)((*it)->getActualLoadAddress());
- uintptr_t segmentSize = (*it)->getSize();
- //fprintf(stderr, "unmapping segment %s at %p for %s\n", (*it)->getName(), segmentAddress, this->getPath());
- // save load commands at beginning of __TEXT segment
- if ( segmentAddress == fMachOData ) {
- // typically load commands are one or two pages in size, so ok to alloc on stack
- uint32_t loadCmdSize = sizeof(macho_header) + ((macho_header*)fMachOData)->sizeofcmds;
- uint32_t loadCmdPages = (loadCmdSize+4095) & (-4096);
- uint8_t loadcommands[loadCmdPages];
- memcpy(loadcommands, fMachOData, loadCmdPages);
- // unmap whole __TEXT segment
- munmap((void*)(fMachOData), segmentSize);
- // allocate and copy back mach_header and load commands
- vm_address_t addr = (vm_address_t)fMachOData;
- int r2 = vm_allocate(mach_task_self(), &addr, loadCmdPages, false /*at this address*/);
- if ( r2 != 0 )
- fprintf(stderr, "prebindUnmap() vm_allocate for __TEXT %d failed\n", loadCmdPages);
- memcpy((void*)fMachOData, loadcommands, loadCmdPages);
- //fprintf(stderr, "copying back load commands to %p size=%u for %s\n", segmentAddress, loadCmdPages, this->getPath());
- }
- else if ( strcmp((*it)->getName(), "__LINKEDIT") == 0 ) {
- uint32_t linkEditSize = segmentSize;
- uint32_t linkEditPages = (linkEditSize+4095) & (-4096);
- void* linkEditTmp = malloc(linkEditPages);
- memcpy(linkEditTmp, segmentAddress, linkEditPages);
- // unmap whole __LINKEDIT segment
- munmap(segmentAddress, segmentSize);
- vm_address_t addr = (vm_address_t)segmentAddress;
- int r2 = vm_allocate(mach_task_self(), &addr, linkEditPages, false /*at this address*/);
- if ( r2 != 0 )
- fprintf(stderr, "prebindUnmap() vm_allocate for __LINKEDIT %d failed\n", linkEditPages);
- memcpy(segmentAddress, linkEditTmp, linkEditPages);
- //fprintf(stderr, "copying back __LINKEDIT to %p size=%u for %s\n", segmentAddress, linkEditPages, this->getPath());
- free(linkEditTmp);
- }
- else {
- // unmap any other segment
- munmap((void*)(segmentAddress), (*it)->getSize());
- }
- }
-}
-
-
-
-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;
-}
-
-
-
-
-