ImageLoaderMachO.cpp [plain text]
#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"
extern "C" void sys_icache_invalidate(void *, size_t);
#if __ppc__
#include <ppc_intrinsics.h>
#else
#define astrcmp(a,b) strcmp(a,b)
#endif
#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;
#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
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;
}
ImageLoaderMachO::ImageLoaderMachO(const char* moduleName, const struct mach_header* mh, uint64_t len, const LinkContext& context)
: ImageLoader(moduleName)
{
this->init();
fMachOData = (const uint8_t*)mh;
this->instantiateSegments((const uint8_t*)mh);
if ( mh->filetype != MH_EXECUTE )
ImageLoader::mapSegments((const void*)mh, len, context);
this->parseLoadCmds();
}
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)
{
this->init();
const unsigned int dataSize = sizeof(macho_header) + ((macho_header*)firstPage)->sizeofcmds;
uint8_t buffer[dataSize];
const uint8_t* fileData = firstPage;
if ( dataSize > 4096 ) {
fileData = buffer;
memcpy(buffer, firstPage, 4096);
pread(fd, &buffer[4096], dataSize-4096, offsetInFat+4096);
}
fMachOData = fileData;
fIsSplitSeg = ((((macho_header*)fileData)->flags & MH_SPLIT_SEGS) != 0) && (((macho_header*)fileData)->filetype == MH_DYLIB);
this->instantiateSegments(fileData);
if ( ((macho_header*)fileData)->filetype != MH_EXECUTE )
this->mapSegments(fd, offsetInFat, lenInFat, info.st_size, context);
this->parseLoadCmds();
}
ImageLoaderMachO::~ImageLoaderMachO()
{
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)];
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;
vm_prot_t init_prot;
};
struct _shared_region_range_np {
mach_vm_address_t address;
mach_vm_size_t size;
};
static int
_shared_region_map_file_np(
int fd, unsigned int regionCount, const _shared_region_mapping_np regions[], uint64_t* slide) {
int r = syscall(299, fd, regionCount, regions, slide);
return r;
}
static int
_shared_region_make_private_np(
unsigned int rangeCount, const _shared_region_range_np ranges[]) {
int r = syscall(300, rangeCount, ranges);
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, unsigned int regionCount, const _shared_region_mapping_np regions[]) {
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 ) {
}
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;
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;
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 );
if ( 0 != r ) {
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; 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;
}
}
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 ) {
}
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;
mmapAddress = mmap(mmapAddress, size, protection, MAP_FILE | MAP_FIXED | MAP_PRIVATE, fd, offset);
if ( mmapAddress == ((void*)(-1)) )
throw "mmap error";
}
}
sNextAltLoadAddress += biggestDiff;
sNextAltLoadAddress = (sNextAltLoadAddress + 4095) & (-4096);
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;
if ( !fIsSplitSeg )
return ImageLoader::mapSegments(fd, offsetInFat, lenInFat, fileLen, context);
if ( kSharedRegionStartState == sSharedRegionState ) {
if ( hasSharedRegionMapFile() ) {
if ( context.slideAndPackDylibs ) {
sharedRegionMakePrivate(context);
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()
{
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");
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]);
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)
{
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 *slidep = NULL;
int r = _shared_region_map_file_np(fd, mappingTableCount, mappingTable, slidep);
if ( 0 == r ) {
if(NULL != slidep && 0 != *slidep) {
}
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();
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;
this->setSlide(fgNextSplitSegAddress - baseAddress);
}
const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
_shared_region_mapping_np mappingTable[mappingTableCount];
initMappingTable(offsetInFat, mappingTable);
uint64_t slide = 0;
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); 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 ) {
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); 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)
{
void* loadAddress = 0;
loadAddress = mmap(NULL, fileLen, PROT_READ, MAP_FILE, fd, 0);
if ( loadAddress == ((void*)(-1)) )
throw "mmap error";
const unsigned int segmentCount = fSegments.size();
unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
const uintptr_t baseAddress = fSegments[0]->getPreferredLoadAddress();
sf_mapping mappingTable[mappingTableCount];
initMappingTable(offsetInFat, mappingTable, baseAddress);
int flags = 0; static bool firstTime = true;
if ( firstTime ) {
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, (char*)loadAddress, fileLen, &base_address, mappingTableCount, mappingTable, &flags); if ( 0 != r ) {
flags |= ALTERNATE_LOAD_SITE;
r = load_shared_file((char*)fPath,(char*)loadAddress, fileLen, &base_address,
mappingTableCount, mappingTable, &flags);
}
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()
{
const unsigned int segmentCount = fSegments.size();
for(unsigned int i=0; i < segmentCount; ++i){
Segment* seg = fSegments[i];
if ( strcmp(seg->getName(),"__LINKEDIT") == 0 )
fLinkEditBase = (uint8_t*)(seg->getActualLoadAddress() - seg->getFileOffset());
if ( strcmp(seg->getName(),"__TEXT") == 0 ) {
if ( seg->hasFixUps() )
fTextSegmentWithFixups = (SegmentMachO*)seg;
}
if ( (seg->getFileOffset() == 0) && (seg->getFileSize() != 0) ) {
fMachOData = (uint8_t*)(seg->getActualLoadAddress());
}
}
if ( this->hasCoalescedExports() )
++fgCountOfImagesWithWeakExports;
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:
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;
}
bool ImageLoaderMachO::isSubframeworkOf(const LinkContext& context, const ImageLoader* parent) const
{
if ( fReExportThruFramework != NULL ) {
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 ) {
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;
}
bool ImageLoaderMachO::hasSubLibrary(const LinkContext& context, const ImageLoader* child) const
{
if ( fHasSubLibraries ) {
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 ) {
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 ) {
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 ) {
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->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()
{
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 ) {
return getFirstWritableSegmentAddress();
}
#endif
return fSegments[0]->getActualLoadAddress();
}
#if __ppc__
static inline void otherRelocsPPC(uintptr_t* locationToFix, uint8_t relocationType, uint16_t otherHalf, uintptr_t slide)
{
struct ppcInstruction { uint16_t opcode; int16_t immediateValue; };
ppcInstruction* instruction = (ppcInstruction*)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;
}
}
#endif
void ImageLoaderMachO::doRebase(const LinkContext& context)
{
if ( this->usablePrebinding(context) && this->usesTwoLevelNameSpace() ) {
++fgImagesWithUsedPrebinding; return;
}
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 ( fTextSegmentWithFixups != NULL )
fTextSegmentWithFixups->tempWritable();
register const uintptr_t slide = this->fSlide;
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 ) {
}
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:
otherRelocsPPC((uintptr_t*)(reloc->r_address + relocBase), reloc->r_type, reloc[1].r_address, slide);
++reloc; 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:
*locationToFix = sreloc->r_value + slide;
break;
#endif
#if __ppc__
case PPC_RELOC_HI16:
case PPC_RELOC_LO16:
case PPC_RELOC_HA16:
++reloc; otherRelocsPPC(locationToFix, sreloc->r_type, reloc->r_address, slide);
break;
#endif
#if __i386__
case GENERIC_RELOC_PB_LA_PTR:
*locationToFix = sreloc->r_value + slide;
break;
#endif
default:
throw "unknown local scattered relocation type";
}
}
else {
throw "bad local scattered relocation length";
}
}
#endif
}
if ( fTextSegmentWithFixups != NULL ) {
fTextSegmentWithFixups->setPermissions();
sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(), fTextSegmentWithFixups->getSize());
}
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;
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 ) {
low = mid + 1;
}
else {
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 ) {
base = &pivot[1];
--n;
}
else {
}
}
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 ) {
if ( (theHint != NULL) && (theHint->isub_image > 0) && (theHint->isub_image <= fLibrariesCount) ) {
uint32_t index = 0;
ImageLoader* target = NULL;
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) {
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;
}
}
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;
}
}
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;
}
}
}
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 ( ((symbol->n_type & N_TYPE) == N_SECT) && ((symbol->n_desc & N_WEAK_DEF) != 0) )
return true;
if ( ((symbol->n_type & N_TYPE) != N_SECT) && ((symbol->n_desc & N_REF_TO_WEAK) != 0) )
return true;
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); }
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 ) {
const Symbol* sym;
if ( context.flatExportFinder(symbolName, &sym, foundIn) )
return (*foundIn)->getExportedSymbolAddress(sym);
if ( this->isBundle() && this->hasHiddenExports() ) {
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) ) {
uintptr_t addr = undefinedSymbol->n_value + this->fSlide;
*foundIn = this;
return addr;
}
if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
return 0;
}
throwSymbolNotFound(symbolName, this->getPath(), "flat namespace");
}
else {
if ( this->needsCoalescing() && symbolRequiresCoalescing(undefinedSymbol) ) {
const Symbol* sym;
if ( context.coalescedExportFinder(symbolName, &sym, foundIn) )
return (*foundIn)->getExportedSymbolAddress(sym);
}
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 ) {
const Symbol* sym;
if ( context.flatExportFinder(symbolName, &sym, foundIn) )
return (*foundIn)->getExportedSymbolAddress(sym);
context.undefinedHandler(symbolName);
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) ) {
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";
}
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 ) {
*foundIn = this;
return undefinedSymbol->n_value + fSlide;
}
else if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
return 0;
}
throwSymbolNotFound(symbolName, this->getPath(), target->getPath());
}
}
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) ) {
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 {
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 ( fTextSegmentWithFixups != NULL )
fTextSegmentWithFixups->tempWritable();
const struct macho_nlist* lastUndefinedSymbol = 0;
uintptr_t symbolAddr = 0;
ImageLoader* image = NULL;
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 ( 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 ) {
if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_WEAK_DEF) != 0) ) {
if ( (value == undefinedSymbol->n_value) || this->isAddrInSection(value, undefinedSymbol->n_sect) )
value -= undefinedSymbol->n_value;
else
value = 0;
}
else {
value -= undefinedSymbol->n_value;
}
}
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 {
if ( !prebound || (*location != value) )
*location = value;
}
#else
if ( !prebound || (*location != value) )
*location = value;
#endif
}
break;
default:
throw "unknown external relocation type";
}
}
else {
throw "bad external relocation length";
}
}
if ( fTextSegmentWithFixups != NULL ) {
fTextSegmentWithFixups->setPermissions();
sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(), fTextSegmentWithFixups->getSize());
}
fgTotalBindFixups += fDynamicInfo->nextrel;
}
const mach_header* ImageLoaderMachO::machHeader() const
{
return (mach_header*)fMachOData;
}
uintptr_t ImageLoaderMachO::getSlide() const
{
return fSlide;
}
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__
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);
jmpTableEntryToPatch[0] = 0xE9; 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)
{
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) ) {
uint8_t* const jmpTableBase = (uint8_t*)(sect->addr + fSlide);
uint8_t* const jmpTableEnd = jmpTableBase + sect->size;
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)
{
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 ) {
fgTotalPossibleLazyBindFixups += elementCount;
if ( bindness == kNonLazyOnly )
continue;
}
#if __i386__
else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
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) {
}
else {
const struct macho_nlist* sym = &fSymbolTable[symbolIndex];
if ( symbolIndex == 0 ) {
if ( ((const macho_header*)fMachOData)->filetype == MH_EXECUTE ) {
static bool alreadyWarned = false;
if ( (sym->n_type & N_TYPE) != N_UNDF ) {
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 ( onlyCoalescedSymbols && !symbolRequiresCoalescing(sym) )
continue;
uintptr_t symbolAddr;
symbolAddr = resolveUndefined(context, sym, twoLevel, &image);
symbolAddr = this->bindIndirectSymbol((uintptr_t*)ptrToBind, sect, &fStrings[sym->n_un.n_strx], symbolAddr, image, context);
}
}
fgTotalBindFixups += elementCount;
}
}
break;
}
cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
}
}
struct DATAdyld {
void* dyldLazyBinder; void* dyldFuncLookup; void* startDebugThread; void* debugPort; void* debugThread; void* stubBindHelper; void* coreDebug; };
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;
}
#ifdef __ppc__
#endif
}
#if __i386__
if ( ! this->usablePrebinding(context) || !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;
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) ) {
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; 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 ( this->isPrebindable() && this->allDependentLibrariesAsWhenPreBound() && (this->getSlide() == 0) ) {
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)
{
this->setupLazyPointerHandler(context);
if ( this->usablePrebinding(context) && this->usesTwoLevelNameSpace() ) {
if ( this->needsCoalescing() && (fgCountOfImagesWithWeakExports > 1) ) {
this->doBindExternalRelocations(context, true);
this->doBindIndirectSymbolPointers(context, kLazyAndNonLazy, true);
}
return;
}
switch (bindness) {
case kNonLazyOnly:
case kLazyAndNonLazy:
this->doBindExternalRelocations(context, false);
break;
case kLazyOnly:
case kLazyOnlyNoDependents:
break;
}
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)
{
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)
{
this->applyPrebindingToDATA(fileToPrebind);
this->applyPrebindingToLoadCommands(context, fileToPrebind, timestamp);
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:
{
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 ) {
ImageLoaderMachO* targetImage = (ImageLoaderMachO*)(dl->image); if ( ! targetImage->isPrebindable() )
throw "dependent dylib is not prebound";
if ( ! targetImage->usablePrebinding(context) ) {
dylib->dylib.timestamp = timestamp;
}
else {
dylib->dylib.timestamp = targetImage->doGetLibraryInfo().checksum;
}
break;
}
}
}
break;
case LC_ID_DYLIB:
{
struct dylib_command* dylib = (struct dylib_command*)cmd;
dylib->dylib.timestamp = timestamp;
}
break;
case LC_SEGMENT_COMMAND:
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 ( 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)
{
const char* stringPool = NULL;
struct macho_nlist* symbolTable = NULL;
const struct dysymtab_command* dysymtab = NULL;
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);
}
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);
}
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;
}
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;
}
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 ( 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;
}
}
}
}
void ImageLoaderMachO::prebindUnmap(const LinkContext& context)
{
for (std::vector<class Segment*>::iterator it=fSegments.begin(); it != fSegments.end(); ++it) {
void* segmentAddress = (void*)((*it)->getActualLoadAddress());
uintptr_t segmentSize = (*it)->getSize();
if ( segmentAddress == fMachOData ) {
uint32_t loadCmdSize = sizeof(macho_header) + ((macho_header*)fMachOData)->sizeofcmds;
uint32_t loadCmdPages = (loadCmdSize+4095) & (-4096);
uint8_t loadcommands[loadCmdPages];
memcpy(loadcommands, fMachOData, loadCmdPages);
munmap((void*)(fMachOData), segmentSize);
vm_address_t addr = (vm_address_t)fMachOData;
int r2 = vm_allocate(mach_task_self(), &addr, loadCmdPages, false );
if ( r2 != 0 )
fprintf(stderr, "prebindUnmap() vm_allocate for __TEXT %d failed\n", loadCmdPages);
memcpy((void*)fMachOData, loadcommands, loadCmdPages);
}
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);
munmap(segmentAddress, segmentSize);
vm_address_t addr = (vm_address_t)segmentAddress;
int r2 = vm_allocate(mach_task_self(), &addr, linkEditPages, false );
if ( r2 != 0 )
fprintf(stderr, "prebindUnmap() vm_allocate for __LINKEDIT %d failed\n", linkEditPages);
memcpy(segmentAddress, linkEditTmp, linkEditPages);
free(linkEditTmp);
}
else {
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';
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 ) {
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;
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;
}