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/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
*
* Copyright (c) 2004-2010 Apple Inc. All rights reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/
#define __STDC_LIMIT_MACROS
#include <stdint.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <mach/mach.h>
#include <mach-o/fat.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <libkern/OSAtomic.h>
#include "ImageLoader.h"
uint32_t ImageLoader::fgImagesUsedFromSharedCache = 0;
uint32_t ImageLoader::fgImagesWithUsedPrebinding = 0;
uint32_t ImageLoader::fgImagesRequiringCoalescing = 0;
uint32_t ImageLoader::fgImagesHasWeakDefinitions = 0;
uint32_t ImageLoader::fgTotalRebaseFixups = 0;
uint32_t ImageLoader::fgTotalBindFixups = 0;
uint32_t ImageLoader::fgTotalBindSymbolsResolved = 0;
uint32_t ImageLoader::fgTotalBindImageSearches = 0;
uint32_t ImageLoader::fgTotalLazyBindFixups = 0;
uint32_t ImageLoader::fgTotalPossibleLazyBindFixups = 0;
uint32_t ImageLoader::fgTotalSegmentsMapped = 0;
uint64_t ImageLoader::fgTotalBytesMapped = 0;
uint64_t ImageLoader::fgTotalBytesPreFetched = 0;
uint64_t ImageLoader::fgTotalLoadLibrariesTime;
uint64_t ImageLoader::fgTotalRebaseTime;
uint64_t ImageLoader::fgTotalBindTime;
uint64_t ImageLoader::fgTotalWeakBindTime;
uint64_t ImageLoader::fgTotalDOF;
uint64_t ImageLoader::fgTotalInitTime;
uint16_t ImageLoader::fgLoadOrdinal = 0;
std::vector<ImageLoader::InterposeTuple>ImageLoader::fgInterposingTuples;
uintptr_t ImageLoader::fgNextPIEDylibAddress = 0;
ImageLoader::ImageLoader(const char* path, unsigned int libCount)
: fPath(path), fRealPath(NULL), fDevice(0), fInode(0), fLastModified(0),
fPathHash(0), fDlopenReferenceCount(0), fInitializerRecursiveLock(NULL),
fDepth(0), fLoadOrder(fgLoadOrdinal++), fState(0), fLibraryCount(libCount),
fAllLibraryChecksumsAndLoadAddressesMatch(false), fLeaveMapped(false), fNeverUnload(false),
fHideSymbols(false), fMatchByInstallName(false),
fInterposed(false), fRegisteredDOF(false), fAllLazyPointersBound(false),
fBeingRemoved(false), fAddFuncNotified(false),
fPathOwnedByImage(false), fIsReferencedDownward(false),
fWeakSymbolsBound(false)
{
if ( fPath != NULL )
fPathHash = hash(fPath);
if ( libCount > 512 )
dyld::throwf("too many dependent dylibs in %s", path);
}
void ImageLoader::deleteImage(ImageLoader* image)
{
delete image;
}
ImageLoader::~ImageLoader()
{
if ( fRealPath != NULL )
delete [] fRealPath;
if ( fPathOwnedByImage && (fPath != NULL) )
delete [] fPath;
}
void ImageLoader::setFileInfo(dev_t device, ino_t inode, time_t modDate)
{
fDevice = device;
fInode = inode;
fLastModified = modDate;
}
void ImageLoader::setMapped(const LinkContext& context)
{
fState = dyld_image_state_mapped;
context.notifySingle(dyld_image_state_mapped, this); // note: can throw exception
}
int ImageLoader::compare(const ImageLoader* right) const
{
if ( this->fDepth == right->fDepth ) {
if ( this->fLoadOrder == right->fLoadOrder )
return 0;
else if ( this->fLoadOrder < right->fLoadOrder )
return -1;
else
return 1;
}
else {
if ( this->fDepth < right->fDepth )
return -1;
else
return 1;
}
}
void ImageLoader::setPath(const char* path)
{
if ( fPathOwnedByImage && (fPath != NULL) )
delete [] fPath;
fPath = new char[strlen(path)+1];
strcpy((char*)fPath, path);
fPathOwnedByImage = true; // delete fPath when this image is destructed
fPathHash = hash(fPath);
fRealPath = NULL;
}
void ImageLoader::setPathUnowned(const char* path)
{
if ( fPathOwnedByImage && (fPath != NULL) ) {
delete [] fPath;
}
fPath = path;
fPathOwnedByImage = false;
fPathHash = hash(fPath);
}
void ImageLoader::setPaths(const char* path, const char* realPath)
{
this->setPath(path);
fRealPath = new char[strlen(realPath)+1];
strcpy((char*)fRealPath, realPath);
}
const char* ImageLoader::getRealPath() const
{
if ( fRealPath != NULL )
return fRealPath;
else
return fPath;
}
uint32_t ImageLoader::hash(const char* path)
{
// this does not need to be a great hash
// it is just used to reduce the number of strcmp() calls
// of existing images when loading a new image
uint32_t h = 0;
for (const char* s=path; *s != '\0'; ++s)
h = h*5 + *s;
return h;
}
bool ImageLoader::matchInstallPath() const
{
return fMatchByInstallName;
}
void ImageLoader::setMatchInstallPath(bool match)
{
fMatchByInstallName = match;
}
bool ImageLoader::statMatch(const struct stat& stat_buf) const
{
return ( (this->fDevice == stat_buf.st_dev) && (this->fInode == stat_buf.st_ino) );
}
const char* ImageLoader::getShortName() const
{
// try to return leaf name
if ( fPath != NULL ) {
const char* s = strrchr(fPath, '/');
if ( s != NULL )
return &s[1];
}
return fPath;
}
void ImageLoader::setLeaveMapped()
{
fLeaveMapped = true;
}
void ImageLoader::setHideExports(bool hide)
{
fHideSymbols = hide;
}
bool ImageLoader::hasHiddenExports() const
{
return fHideSymbols;
}
bool ImageLoader::isLinked() const
{
return (fState >= dyld_image_state_bound);
}
time_t ImageLoader::lastModified() const
{
return fLastModified;
}
bool ImageLoader::containsAddress(const void* addr) const
{
for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
const uint8_t* start = (const uint8_t*)segActualLoadAddress(i);
const uint8_t* end = (const uint8_t*)segActualEndAddress(i);
if ( (start <= addr) && (addr < end) && !segUnaccessible(i) )
return true;
}
return false;
}
bool ImageLoader::overlapsWithAddressRange(const void* start, const void* end) const
{
for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
const uint8_t* segStart = (const uint8_t*)segActualLoadAddress(i);
const uint8_t* segEnd = (const uint8_t*)segActualEndAddress(i);
if ( strcmp(segName(i), "__UNIXSTACK") == 0 ) {
// __UNIXSTACK never slides. This is the only place that cares
// and checking for that segment name in segActualLoadAddress()
// is too expensive.
segStart -= getSlide();
segEnd -= getSlide();
}
if ( (start <= segStart) && (segStart < end) )
return true;
if ( (start <= segEnd) && (segEnd < end) )
return true;
if ( (segStart < start) && (end < segEnd) )
return true;
}
return false;
}
void ImageLoader::getMappedRegions(MappedRegion*& regions) const
{
for(unsigned int i=0, e=segmentCount(); i < e; ++i) {
MappedRegion region;
region.address = segActualLoadAddress(i);
region.size = segSize(i);
*regions++ = region;
}
}
bool ImageLoader::dependsOn(ImageLoader* image) {
for(unsigned int i=0; i < libraryCount(); ++i) {
if ( libImage(i) == image )
return true;
}
return false;
}
static bool notInImgageList(const ImageLoader* image, const ImageLoader** dsiStart, const ImageLoader** dsiCur)
{
for (const ImageLoader** p = dsiStart; p < dsiCur; ++p)
if ( *p == image )
return false;
return true;
}
// private method that handles circular dependencies by only search any image once
const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImagesExcept(const char* name,
const ImageLoader** dsiStart, const ImageLoader**& dsiCur, const ImageLoader** dsiEnd, const ImageLoader** foundIn) const
{
const ImageLoader::Symbol* sym;
// search self
if ( notInImgageList(this, dsiStart, dsiCur) ) {
sym = this->findExportedSymbol(name, false, foundIn);
if ( sym != NULL )
return sym;
*dsiCur++ = this;
}
// search directly dependent libraries
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( (dependentImage != NULL) && notInImgageList(dependentImage, dsiStart, dsiCur) ) {
const ImageLoader::Symbol* sym = dependentImage->findExportedSymbol(name, false, foundIn);
if ( sym != NULL )
return sym;
}
}
// search indirectly dependent libraries
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( (dependentImage != NULL) && notInImgageList(dependentImage, dsiStart, dsiCur) ) {
*dsiCur++ = dependentImage;
const ImageLoader::Symbol* sym = dependentImage->findExportedSymbolInDependentImagesExcept(name, dsiStart, dsiCur, dsiEnd, foundIn);
if ( sym != NULL )
return sym;
}
}
return NULL;
}
const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImages(const char* name, const LinkContext& context, const ImageLoader** foundIn) const
{
unsigned int imageCount = context.imageCount();
const ImageLoader* dontSearchImages[imageCount];
dontSearchImages[0] = this; // don't search this image
const ImageLoader** cur = &dontSearchImages[1];
return this->findExportedSymbolInDependentImagesExcept(name, &dontSearchImages[0], cur, &dontSearchImages[imageCount], foundIn);
}
const ImageLoader::Symbol* ImageLoader::findExportedSymbolInImageOrDependentImages(const char* name, const LinkContext& context, const ImageLoader** foundIn) const
{
unsigned int imageCount = context.imageCount();
const ImageLoader* dontSearchImages[imageCount];
const ImageLoader** cur = &dontSearchImages[0];
return this->findExportedSymbolInDependentImagesExcept(name, &dontSearchImages[0], cur, &dontSearchImages[imageCount], foundIn);
}
// this is called by initializeMainExecutable() to interpose on the initial set of images
void ImageLoader::applyInterposing(const LinkContext& context)
{
if ( fgInterposingTuples.size() != 0 )
this->recursiveApplyInterposing(context);
}
uintptr_t ImageLoader::interposedAddress(const LinkContext& context, uintptr_t address, const ImageLoader* inImage, const ImageLoader* onlyInImage)
{
//dyld::log("interposedAddress(0x%08llX), tupleCount=%lu\n", (uint64_t)address, fgInterposingTuples.size());
for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
//dyld::log(" interposedAddress: replacee=0x%08llX, replacement=0x%08llX, neverImage=%p, onlyImage=%p, inImage=%p\n",
// (uint64_t)it->replacee, (uint64_t)it->replacement, it->neverImage, it->onlyImage, inImage);
// replace all references to 'replacee' with 'replacement'
if ( (address == it->replacee) && (inImage != it->neverImage) && ((it->onlyImage == NULL) || (inImage == it->onlyImage)) ) {
if ( context.verboseInterposing ) {
dyld::log("dyld interposing: replace 0x%lX with 0x%lX\n", it->replacee, it->replacement);
}
return it->replacement;
}
}
return address;
}
void ImageLoader::addDynamicInterposingTuples(const struct dyld_interpose_tuple array[], size_t count)
{
for(size_t i=0; i < count; ++i) {
ImageLoader::InterposeTuple tuple;
tuple.replacement = (uintptr_t)array[i].replacement;
tuple.neverImage = NULL;
tuple.onlyImage = this;
tuple.replacee = (uintptr_t)array[i].replacee;
// chain to any existing interpositions
for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
if ( (it->replacee == tuple.replacee) && (it->onlyImage == this) ) {
tuple.replacee = it->replacement;
}
}
ImageLoader::fgInterposingTuples.push_back(tuple);
}
}
void ImageLoader::link(const LinkContext& context, bool forceLazysBound, bool preflightOnly, bool neverUnload, const RPathChain& loaderRPaths)
{
//dyld::log("ImageLoader::link(%s) refCount=%d, neverUnload=%d\n", this->getPath(), fDlopenReferenceCount, fNeverUnload);
// clear error strings
(*context.setErrorStrings)(dyld_error_kind_none, NULL, NULL, NULL);
uint64_t t0 = mach_absolute_time();
this->recursiveLoadLibraries(context, preflightOnly, loaderRPaths);
context.notifyBatch(dyld_image_state_dependents_mapped);
// we only do the loading step for preflights
if ( preflightOnly )
return;
uint64_t t1 = mach_absolute_time();
context.clearAllDepths();
this->recursiveUpdateDepth(context.imageCount());
uint64_t t2 = mach_absolute_time();
this->recursiveRebase(context);
context.notifyBatch(dyld_image_state_rebased);
uint64_t t3 = mach_absolute_time();
this->recursiveBind(context, forceLazysBound, neverUnload);
uint64_t t4 = mach_absolute_time();
if ( !context.linkingMainExecutable )
this->weakBind(context);
uint64_t t5 = mach_absolute_time();
context.notifyBatch(dyld_image_state_bound);
uint64_t t6 = mach_absolute_time();
std::vector<DOFInfo> dofs;
this->recursiveGetDOFSections(context, dofs);
context.registerDOFs(dofs);
uint64_t t7 = mach_absolute_time();
// interpose any dynamically loaded images
if ( !context.linkingMainExecutable && (fgInterposingTuples.size() != 0) ) {
this->recursiveApplyInterposing(context);
}
// clear error strings
(*context.setErrorStrings)(dyld_error_kind_none, NULL, NULL, NULL);
fgTotalLoadLibrariesTime += t1 - t0;
fgTotalRebaseTime += t3 - t2;
fgTotalBindTime += t4 - t3;
fgTotalWeakBindTime += t5 - t4;
fgTotalDOF += t7 - t6;
// done with initial dylib loads
fgNextPIEDylibAddress = 0;
}
void ImageLoader::printReferenceCounts()
{
dyld::log(" dlopen=%d for %s\n", fDlopenReferenceCount, getPath() );
}
bool ImageLoader::decrementDlopenReferenceCount()
{
if ( fDlopenReferenceCount == 0 )
return true;
--fDlopenReferenceCount;
return false;
}
// <rdar://problem/14412057> upward dylib initializers can be run too soon
// To handle dangling dylibs which are upward linked but not downward, all upward linked dylibs
// have their initialization postponed until after the recursion through downward dylibs
// has completed.
void ImageLoader::processInitializers(const LinkContext& context, mach_port_t thisThread,
InitializerTimingList& timingInfo, ImageLoader::UninitedUpwards& images)
{
uint32_t maxImageCount = context.imageCount();
ImageLoader::UninitedUpwards upsBuffer[maxImageCount];
ImageLoader::UninitedUpwards& ups = upsBuffer[0];
ups.count = 0;
// Calling recursive init on all images in images list, building a new list of
// uninitialized upward dependencies.
for (uintptr_t i=0; i < images.count; ++i) {
images.images[i]->recursiveInitialization(context, thisThread, timingInfo, ups);
}
// If any upward dependencies remain, init them.
if ( ups.count > 0 )
processInitializers(context, thisThread, timingInfo, ups);
}
void ImageLoader::runInitializers(const LinkContext& context, InitializerTimingList& timingInfo)
{
uint64_t t1 = mach_absolute_time();
mach_port_t thisThread = mach_thread_self();
ImageLoader::UninitedUpwards up;
up.count = 1;
up.images[0] = this;
processInitializers(context, thisThread, timingInfo, up);
context.notifyBatch(dyld_image_state_initialized);
mach_port_deallocate(mach_task_self(), thisThread);
uint64_t t2 = mach_absolute_time();
fgTotalInitTime += (t2 - t1);
}
void ImageLoader::bindAllLazyPointers(const LinkContext& context, bool recursive)
{
if ( ! fAllLazyPointersBound ) {
fAllLazyPointersBound = true;
if ( recursive ) {
// bind lower level libraries first
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL )
dependentImage->bindAllLazyPointers(context, recursive);
}
}
// bind lazies in this image
this->doBindJustLazies(context);
}
}
bool ImageLoader::allDependentLibrariesAsWhenPreBound() const
{
return fAllLibraryChecksumsAndLoadAddressesMatch;
}
void ImageLoader::markedUsedRecursive(const std::vector<DynamicReference>& dynamicReferences)
{
// already visited here
if ( fMarkedInUse )
return;
fMarkedInUse = true;
// clear mark on all statically dependent dylibs
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL ) {
dependentImage->markedUsedRecursive(dynamicReferences);
}
}
// clear mark on all dynamically dependent dylibs
for (std::vector<ImageLoader::DynamicReference>::const_iterator it=dynamicReferences.begin(); it != dynamicReferences.end(); ++it) {
if ( it->from == this )
it->to->markedUsedRecursive(dynamicReferences);
}
}
unsigned int ImageLoader::recursiveUpdateDepth(unsigned int maxDepth)
{
// the purpose of this phase is to make the images sortable such that
// in a sort list of images, every image that an image depends on
// occurs in the list before it.
if ( fDepth == 0 ) {
// break cycles
fDepth = maxDepth;
// get depth of dependents
unsigned int minDependentDepth = maxDepth;
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( (dependentImage != NULL) && !libIsUpward(i) ) {
unsigned int d = dependentImage->recursiveUpdateDepth(maxDepth);
if ( d < minDependentDepth )
minDependentDepth = d;
}
}
// make me less deep then all my dependents
fDepth = minDependentDepth - 1;
}
return fDepth;
}
void ImageLoader::recursiveLoadLibraries(const LinkContext& context, bool preflightOnly, const RPathChain& loaderRPaths)
{
if ( fState < dyld_image_state_dependents_mapped ) {
// break cycles
fState = dyld_image_state_dependents_mapped;
// get list of libraries this image needs
DependentLibraryInfo libraryInfos[fLibraryCount];
this->doGetDependentLibraries(libraryInfos);
// get list of rpaths that this image adds
std::vector<const char*> rpathsFromThisImage;
this->getRPaths(context, rpathsFromThisImage);
const RPathChain thisRPaths(&loaderRPaths, &rpathsFromThisImage);
// try to load each
bool canUsePrelinkingInfo = true;
for(unsigned int i=0; i < fLibraryCount; ++i){
ImageLoader* dependentLib;
bool depLibReExported = false;
bool depLibReRequired = false;
bool depLibCheckSumsMatch = false;
DependentLibraryInfo& requiredLibInfo = libraryInfos[i];
#if DYLD_SHARED_CACHE_SUPPORT
if ( preflightOnly && context.inSharedCache(requiredLibInfo.name) ) {
// <rdar://problem/5910137> dlopen_preflight() on image in shared cache leaves it loaded but not objc initialized
// in preflight mode, don't even load dylib that are in the shared cache because they will never be unloaded
setLibImage(i, NULL, false, false);
continue;
}
#endif
try {
dependentLib = context.loadLibrary(requiredLibInfo.name, true, this->getPath(), &thisRPaths);
if ( dependentLib == this ) {
// found circular reference, perhaps DYLD_LIBARY_PATH is causing this rdar://problem/3684168
dependentLib = context.loadLibrary(requiredLibInfo.name, false, NULL, NULL);
if ( dependentLib != this )
dyld::warn("DYLD_ setting caused circular dependency in %s\n", this->getPath());
}
if ( fNeverUnload )
dependentLib->setNeverUnload();
if ( requiredLibInfo.upward ) {
}
else {
dependentLib->fIsReferencedDownward = true;
}
LibraryInfo actualInfo = dependentLib->doGetLibraryInfo();
depLibReRequired = requiredLibInfo.required;
depLibCheckSumsMatch = ( actualInfo.checksum == requiredLibInfo.info.checksum );
depLibReExported = requiredLibInfo.reExported;
if ( ! depLibReExported ) {
// for pre-10.5 binaries that did not use LC_REEXPORT_DYLIB
depLibReExported = dependentLib->isSubframeworkOf(context, this) || this->hasSubLibrary(context, dependentLib);
}
// check found library version is compatible
// <rdar://problem/89200806> 0xFFFFFFFF is wildcard that matches any version
if ( (requiredLibInfo.info.minVersion != 0xFFFFFFFF) && (actualInfo.minVersion < requiredLibInfo.info.minVersion) ) {
// record values for possible use by CrashReporter or Finder
dyld::throwf("Incompatible library version: %s requires version %d.%d.%d or later, but %s provides version %d.%d.%d",
this->getShortName(), requiredLibInfo.info.minVersion >> 16, (requiredLibInfo.info.minVersion >> 8) & 0xff, requiredLibInfo.info.minVersion & 0xff,
dependentLib->getShortName(), actualInfo.minVersion >> 16, (actualInfo.minVersion >> 8) & 0xff, actualInfo.minVersion & 0xff);
}
// prebinding for this image disabled if any dependent library changed
if ( !depLibCheckSumsMatch )
canUsePrelinkingInfo = false;
// prebinding for this image disabled unless both this and dependent are in the shared cache
if ( !dependentLib->inSharedCache() || !this->inSharedCache() )
canUsePrelinkingInfo = false;
//if ( context.verbosePrebinding ) {
// if ( !requiredLib.checksumMatches )
// fprintf(stderr, "dyld: checksum mismatch, (%u v %u) for %s referencing %s\n",
// requiredLibInfo.info.checksum, actualInfo.checksum, this->getPath(), dependentLib->getPath());
// if ( dependentLib->getSlide() != 0 )
// fprintf(stderr, "dyld: dependent library slid for %s referencing %s\n", this->getPath(), dependentLib->getPath());
//}
}
catch (const char* msg) {
//if ( context.verbosePrebinding )
// fprintf(stderr, "dyld: exception during processing for %s referencing %s\n", this->getPath(), dependentLib->getPath());
if ( requiredLibInfo.required ) {
fState = dyld_image_state_mapped;
// record values for possible use by CrashReporter or Finder
if ( strstr(msg, "Incompatible") != NULL )
(*context.setErrorStrings)(dyld_error_kind_dylib_version, this->getPath(), requiredLibInfo.name, NULL);
else if ( strstr(msg, "architecture") != NULL )
(*context.setErrorStrings)(dyld_error_kind_dylib_wrong_arch, this->getPath(), requiredLibInfo.name, NULL);
else
(*context.setErrorStrings)(dyld_error_kind_dylib_missing, this->getPath(), requiredLibInfo.name, NULL);
const char* newMsg = dyld::mkstringf("Library not loaded: %s\n Referenced from: %s\n Reason: %s", requiredLibInfo.name, this->getRealPath(), msg);
free((void*)msg); // our free() will do nothing if msg is a string literal
throw newMsg;
}
free((void*)msg); // our free() will do nothing if msg is a string literal
// ok if weak library not found
dependentLib = NULL;
canUsePrelinkingInfo = false; // this disables all prebinding, we may want to just slam import vectors for this lib to zero
}
setLibImage(i, dependentLib, depLibReExported, requiredLibInfo.upward);
}
fAllLibraryChecksumsAndLoadAddressesMatch = canUsePrelinkingInfo;
// tell each to load its dependents
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL ) {
dependentImage->recursiveLoadLibraries(context, preflightOnly, thisRPaths);
}
}
// do deep prebind check
if ( fAllLibraryChecksumsAndLoadAddressesMatch ) {
for(unsigned int i=0; i < libraryCount(); ++i){
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL ) {
if ( !dependentImage->allDependentLibrariesAsWhenPreBound() )
fAllLibraryChecksumsAndLoadAddressesMatch = false;
}
}
}
// free rpaths (getRPaths() malloc'ed each string)
for(std::vector<const char*>::iterator it=rpathsFromThisImage.begin(); it != rpathsFromThisImage.end(); ++it) {
const char* str = *it;
free((void*)str);
}
}
}
void ImageLoader::recursiveRebase(const LinkContext& context)
{
if ( fState < dyld_image_state_rebased ) {
// break cycles
fState = dyld_image_state_rebased;
try {
// rebase lower level libraries first
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL )
dependentImage->recursiveRebase(context);
}
// rebase this image
doRebase(context);
// notify
context.notifySingle(dyld_image_state_rebased, this);
}
catch (const char* msg) {
// this image is not rebased
fState = dyld_image_state_dependents_mapped;
CRSetCrashLogMessage2(NULL);
throw;
}
}
}
void ImageLoader::recursiveApplyInterposing(const LinkContext& context)
{
if ( ! fInterposed ) {
// break cycles
fInterposed = true;
try {
// interpose lower level libraries first
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL )
dependentImage->recursiveApplyInterposing(context);
}
// interpose this image
doInterpose(context);
}
catch (const char* msg) {
// this image is not interposed
fInterposed = false;
throw;
}
}
}
void ImageLoader::recursiveBind(const LinkContext& context, bool forceLazysBound, bool neverUnload)
{
// Normally just non-lazy pointers are bound immediately.
// The exceptions are:
// 1) DYLD_BIND_AT_LAUNCH will cause lazy pointers to be bound immediately
// 2) some API's (e.g. RTLD_NOW) can cause lazy pointers to be bound immediately
if ( fState < dyld_image_state_bound ) {
// break cycles
fState = dyld_image_state_bound;
try {
// bind lower level libraries first
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL )
dependentImage->recursiveBind(context, forceLazysBound, neverUnload);
}
// bind this image
this->doBind(context, forceLazysBound);
// mark if lazys are also bound
if ( forceLazysBound || this->usablePrebinding(context) )
fAllLazyPointersBound = true;
// mark as never-unload if requested
if ( neverUnload )
this->setNeverUnload();
context.notifySingle(dyld_image_state_bound, this);
}
catch (const char* msg) {
// restore state
fState = dyld_image_state_rebased;
CRSetCrashLogMessage2(NULL);
throw;
}
}
}
void ImageLoader::weakBind(const LinkContext& context)
{
if ( context.verboseWeakBind )
dyld::log("dyld: weak bind start:\n");
uint64_t t1 = mach_absolute_time();
// get set of ImageLoaders that participate in coalecsing
ImageLoader* imagesNeedingCoalescing[fgImagesRequiringCoalescing];
int count = context.getCoalescedImages(imagesNeedingCoalescing);
// count how many have not already had weakbinding done
int countNotYetWeakBound = 0;
int countOfImagesWithWeakDefinitions = 0;
int countOfImagesWithWeakDefinitionsNotInSharedCache = 0;
for(int i=0; i < count; ++i) {
if ( ! imagesNeedingCoalescing[i]->fWeakSymbolsBound )
++countNotYetWeakBound;
if ( imagesNeedingCoalescing[i]->hasCoalescedExports() ) {
++countOfImagesWithWeakDefinitions;
if ( ! imagesNeedingCoalescing[i]->inSharedCache() )
++countOfImagesWithWeakDefinitionsNotInSharedCache;
}
}
// don't need to do any coalescing if only one image has overrides, or all have already been done
if ( (countOfImagesWithWeakDefinitionsNotInSharedCache > 0) && (countNotYetWeakBound > 0) ) {
// make symbol iterators for each
ImageLoader::CoalIterator iterators[count];
ImageLoader::CoalIterator* sortedIts[count];
for(int i=0; i < count; ++i) {
imagesNeedingCoalescing[i]->initializeCoalIterator(iterators[i], i);
sortedIts[i] = &iterators[i];
if ( context.verboseWeakBind )
dyld::log("dyld: weak bind load order %d/%d for %s\n", i, count, imagesNeedingCoalescing[i]->getPath());
}
// walk all symbols keeping iterators in sync by
// only ever incrementing the iterator with the lowest symbol
int doneCount = 0;
while ( doneCount != count ) {
//for(int i=0; i < count; ++i)
// dyld::log("sym[%d]=%s ", sortedIts[i]->loadOrder, sortedIts[i]->symbolName);
//dyld::log("\n");
// increment iterator with lowest symbol
if ( sortedIts[0]->image->incrementCoalIterator(*sortedIts[0]) )
++doneCount;
// re-sort iterators
for(int i=1; i < count; ++i) {
int result = strcmp(sortedIts[i-1]->symbolName, sortedIts[i]->symbolName);
if ( result == 0 )
sortedIts[i-1]->symbolMatches = true;
if ( result > 0 ) {
// new one is bigger then next, so swap
ImageLoader::CoalIterator* temp = sortedIts[i-1];
sortedIts[i-1] = sortedIts[i];
sortedIts[i] = temp;
}
if ( result < 0 )
break;
}
// process all matching symbols just before incrementing the lowest one that matches
if ( sortedIts[0]->symbolMatches && !sortedIts[0]->done ) {
const char* nameToCoalesce = sortedIts[0]->symbolName;
// pick first symbol in load order (and non-weak overrides weak)
uintptr_t targetAddr = 0;
ImageLoader* targetImage = NULL;
for(int i=0; i < count; ++i) {
if ( strcmp(iterators[i].symbolName, nameToCoalesce) == 0 ) {
if ( context.verboseWeakBind )
dyld::log("dyld: weak bind, found %s weak=%d in %s \n", nameToCoalesce, iterators[i].weakSymbol, iterators[i].image->getPath());
if ( iterators[i].weakSymbol ) {
if ( targetAddr == 0 ) {
targetAddr = iterators[i].image->getAddressCoalIterator(iterators[i], context);
if ( targetAddr != 0 )
targetImage = iterators[i].image;
}
}
else {
targetAddr = iterators[i].image->getAddressCoalIterator(iterators[i], context);
if ( targetAddr != 0 ) {
targetImage = iterators[i].image;
// strong implementation found, stop searching
break;
}
}
}
}
// tell each to bind to this symbol (unless already bound)
if ( targetAddr != 0 ) {
if ( context.verboseWeakBind )
dyld::log("dyld: weak binding all uses of %s to copy from %s\n", nameToCoalesce, targetImage->getShortName());
for(int i=0; i < count; ++i) {
if ( strcmp(iterators[i].symbolName, nameToCoalesce) == 0 ) {
if ( context.verboseWeakBind )
dyld::log("dyld: weak bind, setting all uses of %s in %s to 0x%lX from %s\n", nameToCoalesce, iterators[i].image->getShortName(), targetAddr, targetImage->getShortName());
if ( ! iterators[i].image->fWeakSymbolsBound )
iterators[i].image->updateUsesCoalIterator(iterators[i], targetAddr, targetImage, context);
iterators[i].symbolMatches = false;
}
}
}
}
}
// mark all as having all weak symbols bound
for(int i=0; i < count; ++i) {
imagesNeedingCoalescing[i]->fWeakSymbolsBound = true;
}
}
uint64_t t2 = mach_absolute_time();
fgTotalWeakBindTime += t2 - t1;
if ( context.verboseWeakBind )
dyld::log("dyld: weak bind end\n");
}
void ImageLoader::recursiveGetDOFSections(const LinkContext& context, std::vector<DOFInfo>& dofs)
{
if ( ! fRegisteredDOF ) {
// break cycles
fRegisteredDOF = true;
// gather lower level libraries first
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL )
dependentImage->recursiveGetDOFSections(context, dofs);
}
this->doGetDOFSections(context, dofs);
}
}
void ImageLoader::setNeverUnloadRecursive() {
if ( ! fNeverUnload ) {
// break cycles
fNeverUnload = true;
// gather lower level libraries first
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL )
dependentImage->setNeverUnloadRecursive();
}
}
}
void ImageLoader::recursiveSpinLock(recursive_lock& rlock)
{
// try to set image's ivar fInitializerRecursiveLock to point to this lock_info
// keep trying until success (spin)
while ( ! OSAtomicCompareAndSwapPtrBarrier(NULL, &rlock, (void**)&fInitializerRecursiveLock) ) {
// if fInitializerRecursiveLock already points to a different lock_info, if it is for
// the same thread we are on, the increment the lock count, otherwise continue to spin
if ( (fInitializerRecursiveLock != NULL) && (fInitializerRecursiveLock->thread == rlock.thread) )
break;
}
++(fInitializerRecursiveLock->count);
}
void ImageLoader::recursiveSpinUnLock()
{
if ( --(fInitializerRecursiveLock->count) == 0 )
fInitializerRecursiveLock = NULL;
}
void ImageLoader::recursiveInitialization(const LinkContext& context, mach_port_t this_thread,
InitializerTimingList& timingInfo, UninitedUpwards& uninitUps)
{
recursive_lock lock_info(this_thread);
recursiveSpinLock(lock_info);
if ( fState < dyld_image_state_dependents_initialized-1 ) {
uint8_t oldState = fState;
// break cycles
fState = dyld_image_state_dependents_initialized-1;
try {
// initialize lower level libraries first
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL ) {
// don't try to initialize stuff "above" me yet
if ( libIsUpward(i) ) {
uninitUps.images[uninitUps.count] = dependentImage;
uninitUps.count++;
}
else if ( dependentImage->fDepth >= fDepth ) {
dependentImage->recursiveInitialization(context, this_thread, timingInfo, uninitUps);
}
}
}
// record termination order
if ( this->needsTermination() )
context.terminationRecorder(this);
// let objc know we are about to initialize this image
uint64_t t1 = mach_absolute_time();
fState = dyld_image_state_dependents_initialized;
oldState = fState;
context.notifySingle(dyld_image_state_dependents_initialized, this);
// initialize this image
bool hasInitializers = this->doInitialization(context);
// let anyone know we finished initializing this image
fState = dyld_image_state_initialized;
oldState = fState;
context.notifySingle(dyld_image_state_initialized, this);
if ( hasInitializers ) {
uint64_t t2 = mach_absolute_time();
timingInfo.images[timingInfo.count].image = this;
timingInfo.images[timingInfo.count].initTime = (t2-t1);
timingInfo.count++;
}
}
catch (const char* msg) {
// this image is not initialized
fState = oldState;
recursiveSpinUnLock();
throw;
}
}
recursiveSpinUnLock();
}
static void printTime(const char* msg, uint64_t partTime, uint64_t totalTime)
{
static uint64_t sUnitsPerSecond = 0;
if ( sUnitsPerSecond == 0 ) {
struct mach_timebase_info timeBaseInfo;
if ( mach_timebase_info(&timeBaseInfo) == KERN_SUCCESS ) {
sUnitsPerSecond = 1000000000ULL * timeBaseInfo.denom / timeBaseInfo.numer;
}
}
if ( partTime < sUnitsPerSecond ) {
uint32_t milliSecondsTimesHundred = (uint32_t)((partTime*100000)/sUnitsPerSecond);
uint32_t milliSeconds = (uint32_t)(milliSecondsTimesHundred/100);
uint32_t percentTimesTen = (uint32_t)((partTime*1000)/totalTime);
uint32_t percent = percentTimesTen/10;
dyld::log("%s: %u.%02u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimesHundred-milliSeconds*100, percent, percentTimesTen-percent*10);
}
else {
uint32_t secondsTimeTen = (uint32_t)((partTime*10)/sUnitsPerSecond);
uint32_t seconds = secondsTimeTen/10;
uint32_t percentTimesTen = (uint32_t)((partTime*1000)/totalTime);
uint32_t percent = percentTimesTen/10;
dyld::log("%s: %u.%u seconds (%u.%u%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
}
}
static char* commatize(uint64_t in, char* out)
{
uint64_t div10 = in / 10;
uint8_t delta = in - div10*10;
char* s = &out[32];
int digitCount = 1;
*s = '\0';
*(--s) = '0' + delta;
in = div10;
while ( in != 0 ) {
if ( (digitCount % 3) == 0 )
*(--s) = ',';
div10 = in / 10;
delta = in - div10*10;
*(--s) = '0' + delta;
in = div10;
++digitCount;
}
return s;
}
void ImageLoader::printStatistics(unsigned int imageCount, const InitializerTimingList& timingInfo)
{
uint64_t totalTime = fgTotalLoadLibrariesTime + fgTotalRebaseTime + fgTotalBindTime + fgTotalWeakBindTime + fgTotalDOF + fgTotalInitTime;
char commaNum1[40];
char commaNum2[40];
printTime("total time", totalTime, totalTime);
#if __IPHONE_OS_VERSION_MIN_REQUIRED
if ( fgImagesUsedFromSharedCache != 0 )
dyld::log("total images loaded: %d (%u from dyld shared cache)\n", imageCount, fgImagesUsedFromSharedCache);
else
dyld::log("total images loaded: %d\n", imageCount);
#else
dyld::log("total images loaded: %d (%u from dyld shared cache)\n", imageCount, fgImagesUsedFromSharedCache);
#endif
dyld::log("total segments mapped: %u, into %llu pages with %llu pages pre-fetched\n", fgTotalSegmentsMapped, fgTotalBytesMapped/4096, fgTotalBytesPreFetched/4096);
printTime("total images loading time", fgTotalLoadLibrariesTime, totalTime);
printTime("total dtrace DOF registration time", fgTotalDOF, totalTime);
dyld::log("total rebase fixups: %s\n", commatize(fgTotalRebaseFixups, commaNum1));
printTime("total rebase fixups time", fgTotalRebaseTime, totalTime);
dyld::log("total binding fixups: %s\n", commatize(fgTotalBindFixups, commaNum1));
if ( fgTotalBindSymbolsResolved != 0 ) {
uint32_t avgTimesTen = (fgTotalBindImageSearches * 10) / fgTotalBindSymbolsResolved;
uint32_t avgInt = fgTotalBindImageSearches / fgTotalBindSymbolsResolved;
uint32_t avgTenths = avgTimesTen - (avgInt*10);
dyld::log("total binding symbol lookups: %s, average images searched per symbol: %u.%u\n",
commatize(fgTotalBindSymbolsResolved, commaNum1), avgInt, avgTenths);
}
printTime("total binding fixups time", fgTotalBindTime, totalTime);
printTime("total weak binding fixups time", fgTotalWeakBindTime, totalTime);
dyld::log("total bindings lazily fixed up: %s of %s\n", commatize(fgTotalLazyBindFixups, commaNum1), commatize(fgTotalPossibleLazyBindFixups, commaNum2));
printTime("total initializer time", fgTotalInitTime, totalTime);
for (uintptr_t i=0; i < timingInfo.count; ++i) {
dyld::log("%21s ", timingInfo.images[i].image->getShortName());
printTime("", timingInfo.images[i].initTime, totalTime);
}
}
//
// copy path and add suffix to result
//
// /path/foo.dylib _debug => /path/foo_debug.dylib
// foo.dylib _debug => foo_debug.dylib
// foo _debug => foo_debug
// /path/bar _debug => /path/bar_debug
// /path/bar.A.dylib _debug => /path/bar.A_debug.dylib
//
void ImageLoader::addSuffix(const char* path, const char* suffix, char* result)
{
strcpy(result, path);
char* start = strrchr(result, '/');
if ( start != NULL )
start++;
else
start = result;
char* dot = strrchr(start, '.');
if ( dot != NULL ) {
strcpy(dot, suffix);
strcat(&dot[strlen(suffix)], &path[dot-result]);
}
else {
strcat(result, suffix);
}
}
VECTOR_NEVER_DESTRUCTED_IMPL(ImageLoader::InterposeTuple);
VECTOR_NEVER_DESTRUCTED_IMPL(ImagePair);