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--- dyld/dyld-239.3/src/ImageLoader.cpp
+++ dyld/dyld-750.6/src/ImageLoader.cpp
@@ -34,7 +34,13 @@
#include <sys/mman.h>
#include <sys/param.h>
#include <sys/mount.h>
+#include <sys/sysctl.h>
#include <libkern/OSAtomic.h>
+#include <string_view>
+
+#include <atomic>
+
+#include "Tracing.h"
#include "ImageLoader.h"
@@ -51,24 +57,27 @@
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::fgTotalObjCSetupTime = 0;
+uint64_t ImageLoader::fgTotalDebuggerPausedTime = 0;
+uint64_t ImageLoader::fgTotalRebindCacheTime = 0;
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;
+uint32_t ImageLoader::fgSymbolTrieSearchs = 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),
+ : 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),
+ fLoadOrder(fgLoadOrdinal++), fDepth(0), fObjCMappedNotified(false), fState(0), fLibraryCount(libCount),
+ fMadeReadOnly(false), fAllLibraryChecksumsAndLoadAddressesMatch(false), fLeaveMapped(false), fNeverUnload(false),
fHideSymbols(false), fMatchByInstallName(false),
fInterposed(false), fRegisteredDOF(false), fAllLazyPointersBound(false),
fBeingRemoved(false), fAddFuncNotified(false),
@@ -106,7 +115,7 @@
void ImageLoader::setMapped(const LinkContext& context)
{
fState = dyld_image_state_mapped;
- context.notifySingle(dyld_image_state_mapped, this); // note: can throw exception
+ context.notifySingle(dyld_image_state_mapped, this, NULL); // note: can throw exception
}
int ImageLoader::compare(const ImageLoader* right) const
@@ -129,13 +138,16 @@
void ImageLoader::setPath(const char* path)
{
- if ( fPathOwnedByImage && (fPath != NULL) )
+ 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;
+ if ( fRealPath != NULL ) {
+ delete [] fRealPath;
+ fRealPath = NULL;
+ }
}
void ImageLoader::setPathUnowned(const char* path)
@@ -144,7 +156,7 @@
delete [] fPath;
}
fPath = path;
- fPathOwnedByImage = false;
+ fPathOwnedByImage = false;
fPathHash = hash(fPath);
}
@@ -155,14 +167,14 @@
strcpy((char*)fRealPath, realPath);
}
-const char* ImageLoader::getRealPath() const
-{
- if ( fRealPath != NULL )
+
+const char* ImageLoader::getRealPath() const
+{
+ if ( fRealPath != NULL )
return fRealPath;
else
- return fPath;
-}
-
+ return fPath;
+}
uint32_t ImageLoader::hash(const char* path)
{
@@ -190,15 +202,20 @@
return ( (this->fDevice == stat_buf.st_dev) && (this->fInode == stat_buf.st_ino) );
}
-const char* ImageLoader::getShortName() const
+const char* ImageLoader::shortName(const char* fullName)
{
// try to return leaf name
- if ( fPath != NULL ) {
- const char* s = strrchr(fPath, '/');
+ if ( fullName != NULL ) {
+ const char* s = strrchr(fullName, '/');
if ( s != NULL )
return &s[1];
}
- return fPath;
+ return fullName;
+}
+
+const char* ImageLoader::getShortName() const
+{
+ return shortName(fPath);
}
void ImageLoader::setLeaveMapped()
@@ -288,6 +305,18 @@
return true;
}
+bool ImageLoader::findExportedSymbolAddress(const LinkContext& context, const char* symbolName,
+ const ImageLoader* requestorImage, int requestorOrdinalOfDef,
+ bool runResolver, const ImageLoader** foundIn, uintptr_t* address) const
+{
+ const Symbol* sym = this->findExportedSymbol(symbolName, true, foundIn);
+ if ( sym != NULL ) {
+ *address = (*foundIn)->getExportedSymbolAddress(sym, context, requestorImage, runResolver);
+ return true;
+ }
+ return false;
+}
+
// private method that handles circular dependencies by only search any image once
const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImagesExcept(const char* name,
@@ -296,7 +325,7 @@
const ImageLoader::Symbol* sym;
// search self
if ( notInImgageList(this, dsiStart, dsiCur) ) {
- sym = this->findExportedSymbol(name, false, foundIn);
+ sym = this->findExportedSymbol(name, false, this->getPath(), foundIn);
if ( sym != NULL )
return sym;
*dsiCur++ = this;
@@ -306,7 +335,7 @@
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);
+ sym = dependentImage->findExportedSymbol(name, false, libPath(i), foundIn);
if ( sym != NULL )
return sym;
}
@@ -317,7 +346,7 @@
ImageLoader* dependentImage = libImage(i);
if ( (dependentImage != NULL) && notInImgageList(dependentImage, dsiStart, dsiCur) ) {
*dsiCur++ = dependentImage;
- const ImageLoader::Symbol* sym = dependentImage->findExportedSymbolInDependentImagesExcept(name, dsiStart, dsiCur, dsiEnd, foundIn);
+ sym = dependentImage->findExportedSymbolInDependentImagesExcept(name, dsiStart, dsiCur, dsiEnd, foundIn);
if ( sym != NULL )
return sym;
}
@@ -329,7 +358,7 @@
const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImages(const char* name, const LinkContext& context, const ImageLoader** foundIn) const
{
- unsigned int imageCount = context.imageCount();
+ unsigned int imageCount = context.imageCount()+2;
const ImageLoader* dontSearchImages[imageCount];
dontSearchImages[0] = this; // don't search this image
const ImageLoader** cur = &dontSearchImages[1];
@@ -338,7 +367,7 @@
const ImageLoader::Symbol* ImageLoader::findExportedSymbolInImageOrDependentImages(const char* name, const LinkContext& context, const ImageLoader** foundIn) const
{
- unsigned int imageCount = context.imageCount();
+ unsigned int imageCount = context.imageCount()+2;
const ImageLoader* dontSearchImages[imageCount];
const ImageLoader** cur = &dontSearchImages[0];
return this->findExportedSymbolInDependentImagesExcept(name, &dontSearchImages[0], cur, &dontSearchImages[imageCount], foundIn);
@@ -347,56 +376,180 @@
// this is called by initializeMainExecutable() to interpose on the initial set of images
void ImageLoader::applyInterposing(const LinkContext& context)
{
+ dyld3::ScopedTimer timer(DBG_DYLD_TIMING_APPLY_INTERPOSING, 0, 0, 0);
if ( fgInterposingTuples.size() != 0 )
this->recursiveApplyInterposing(context);
}
-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);
+
+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::applyInterposingToDyldCache(const LinkContext& context) {
+ if (!context.dyldCache)
+ return;
+ if (!context.dyldCache->header.builtFromChainedFixups)
+ return;
+ if (fgInterposingTuples.empty())
+ return;
+ // For each of the interposed addresses, see if any of them are in the shared cache. If so, find
+ // that image and apply its patch table to all uses.
+ uintptr_t cacheStart = (uintptr_t)context.dyldCache;
+ for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
+ if ( context.verboseInterposing )
+ dyld::log("dyld: interpose: Trying to interpose address 0x%08llx\n", (uint64_t)it->replacee);
+ uint32_t imageIndex;
+ uint32_t cacheOffsetOfReplacee = (uint32_t)(it->replacee - cacheStart);
+ if (!context.dyldCache->addressInText(cacheOffsetOfReplacee, &imageIndex))
+ continue;
+ dyld3::closure::ImageNum imageInCache = imageIndex+1;
+ if ( context.verboseInterposing )
+ dyld::log("dyld: interpose: Found shared cache image %d for 0x%08llx\n", imageInCache, (uint64_t)it->replacee);
+ context.dyldCache->forEachPatchableExport(imageIndex, ^(uint32_t cacheOffsetOfImpl, const char* exportName) {
+ // Skip patching anything other than this symbol
+ if (cacheOffsetOfImpl != cacheOffsetOfReplacee)
+ return;
+ if ( context.verboseInterposing ) {
+ const dyld3::closure::Image* image = context.dyldCache->cachedDylibsImageArray()->imageForNum(imageInCache);
+ dyld::log("dyld: interpose: Patching uses of symbol %s in shared cache binary at %s\n", exportName, image->path());
+ }
+ uintptr_t newLoc = it->replacement;
+ context.dyldCache->forEachPatchableUseOfExport(imageIndex, cacheOffsetOfImpl, ^(dyld_cache_patchable_location patchLocation) {
+ uintptr_t* loc = (uintptr_t*)(cacheStart+patchLocation.cacheOffset);
+#if __has_feature(ptrauth_calls)
+ if ( patchLocation.authenticated ) {
+ dyld3::MachOLoaded::ChainedFixupPointerOnDisk ptr = *(dyld3::MachOLoaded::ChainedFixupPointerOnDisk*)loc;
+ ptr.arm64e.authRebase.auth = true;
+ ptr.arm64e.authRebase.addrDiv = patchLocation.usesAddressDiversity;
+ ptr.arm64e.authRebase.diversity = patchLocation.discriminator;
+ ptr.arm64e.authRebase.key = patchLocation.key;
+ *loc = ptr.arm64e.signPointer(loc, newLoc + DyldSharedCache::getAddend(patchLocation));
+ if ( context.verboseInterposing )
+ dyld::log("dyld: interpose: *%p = %p (JOP: diversity 0x%04X, addr-div=%d, key=%s)\n",
+ loc, (void*)*loc, patchLocation.discriminator, patchLocation.usesAddressDiversity, DyldSharedCache::keyName(patchLocation));
+ return;
+ }
+#endif
+ if ( context.verboseInterposing )
+ dyld::log("dyld: interpose: *%p = 0x%0llX (dyld cache patch) to %s\n", loc, newLoc + DyldSharedCache::getAddend(patchLocation), exportName);
+ *loc = newLoc + (uintptr_t)DyldSharedCache::getAddend(patchLocation);
+ });
+ });
+ }
+}
+
+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);
+ }
+}
+
+// <rdar://problem/29099600> dyld should tell the kernel when it is doing root fix-ups
+void ImageLoader::vmAccountingSetSuspended(const LinkContext& context, bool suspend)
+{
+#if __arm__ || __arm64__
+ static bool sVmAccountingSuspended = false;
+ if ( suspend == sVmAccountingSuspended )
+ return;
+ if ( context.verboseBind )
+ dyld::log("set vm.footprint_suspend=%d\n", suspend);
+ int newValue = suspend ? 1 : 0;
+ int oldValue = 0;
+ size_t newlen = sizeof(newValue);
+ size_t oldlen = sizeof(oldValue);
+ int ret = sysctlbyname("vm.footprint_suspend", &oldValue, &oldlen, &newValue, newlen);
+ if ( context.verboseBind && (ret != 0) )
+ dyld::log("vm.footprint_suspend => %d, errno=%d\n", ret, errno);
+ sVmAccountingSuspended = suspend;
+#endif
+}
+
+
+void ImageLoader::link(const LinkContext& context, bool forceLazysBound, bool preflightOnly, bool neverUnload, const RPathChain& loaderRPaths, const char* imagePath)
+{
+ //dyld::log("ImageLoader::link(%s) refCount=%d, neverUnload=%d\n", imagePath, fDlopenReferenceCount, fNeverUnload);
// clear error strings
- (*context.setErrorStrings)(dyld_error_kind_none, NULL, NULL, NULL);
+ (*context.setErrorStrings)(0, NULL, NULL, NULL);
uint64_t t0 = mach_absolute_time();
- this->recursiveLoadLibraries(context, preflightOnly, loaderRPaths);
- context.notifyBatch(dyld_image_state_dependents_mapped);
-
+ this->recursiveLoadLibraries(context, preflightOnly, loaderRPaths, imagePath);
+ context.notifyBatch(dyld_image_state_dependents_mapped, preflightOnly);
+
// 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();
+ __block uint64_t t2, t3, t4, t5;
+ {
+ dyld3::ScopedTimer(DBG_DYLD_TIMING_APPLY_FIXUPS, 0, 0, 0);
+ t2 = mach_absolute_time();
+ this->recursiveRebaseWithAccounting(context);
+ context.notifyBatch(dyld_image_state_rebased, false);
+
+ t3 = mach_absolute_time();
+ if ( !context.linkingMainExecutable )
+ this->recursiveBindWithAccounting(context, forceLazysBound, neverUnload);
+
+ t4 = mach_absolute_time();
+ if ( !context.linkingMainExecutable )
+ this->weakBind(context);
+ t5 = mach_absolute_time();
+ }
// interpose any dynamically loaded images
if ( !context.linkingMainExecutable && (fgInterposingTuples.size() != 0) ) {
+ dyld3::ScopedTimer timer(DBG_DYLD_TIMING_APPLY_INTERPOSING, 0, 0, 0);
this->recursiveApplyInterposing(context);
}
-
+
+ // now that all fixups are done, make __DATA_CONST segments read-only
+ if ( !context.linkingMainExecutable )
+ this->recursiveMakeDataReadOnly(context);
+
+ if ( !context.linkingMainExecutable )
+ context.notifyBatch(dyld_image_state_bound, false);
+ uint64_t t6 = mach_absolute_time();
+
+ if ( context.registerDOFs != NULL ) {
+ std::vector<DOFInfo> dofs;
+ this->recursiveGetDOFSections(context, dofs);
+ context.registerDOFs(dofs);
+ }
+ uint64_t t7 = mach_absolute_time();
+
// clear error strings
- (*context.setErrorStrings)(dyld_error_kind_none, NULL, NULL, NULL);
+ (*context.setErrorStrings)(0, NULL, NULL, NULL);
fgTotalLoadLibrariesTime += t1 - t0;
fgTotalRebaseTime += t3 - t2;
@@ -423,13 +576,39 @@
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()+2;
+ 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.imagesAndPaths[i].first->recursiveInitialization(context, thisThread, images.imagesAndPaths[i].second, 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 this_thread = mach_thread_self();
- this->recursiveInitialization(context, this_thread, timingInfo);
- context.notifyBatch(dyld_image_state_initialized);
- mach_port_deallocate(mach_task_self(), this_thread);
+ mach_port_t thisThread = mach_thread_self();
+ ImageLoader::UninitedUpwards up;
+ up.count = 1;
+ up.imagesAndPaths[0] = { this, this->getPath() };
+ processInitializers(context, thisThread, timingInfo, up);
+ context.notifyBatch(dyld_image_state_initialized, false);
+ mach_port_deallocate(mach_task_self(), thisThread);
uint64_t t2 = mach_absolute_time();
fgTotalInitTime += (t2 - t1);
}
@@ -511,14 +690,13 @@
}
-void ImageLoader::recursiveLoadLibraries(const LinkContext& context, bool preflightOnly, const RPathChain& loaderRPaths)
+void ImageLoader::recursiveLoadLibraries(const LinkContext& context, bool preflightOnly, const RPathChain& loaderRPaths, const char* loadPath)
{
if ( fState < dyld_image_state_dependents_mapped ) {
// break cycles
fState = dyld_image_state_dependents_mapped;
// get list of libraries this image needs
- //dyld::log("ImageLoader::recursiveLoadLibraries() %ld = %d*%ld\n", fLibrariesCount*sizeof(DependentLibrary), fLibrariesCount, sizeof(DependentLibrary));
DependentLibraryInfo libraryInfos[fLibraryCount];
this->doGetDependentLibraries(libraryInfos);
@@ -532,22 +710,19 @@
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);
+ unsigned cacheIndex;
+ dependentLib = context.loadLibrary(requiredLibInfo.name, true, this->getPath(), &thisRPaths, cacheIndex);
if ( dependentLib == this ) {
// found circular reference, perhaps DYLD_LIBARY_PATH is causing this rdar://problem/3684168
- dependentLib = context.loadLibrary(requiredLibInfo.name, false, NULL, NULL);
+ dependentLib = context.loadLibrary(requiredLibInfo.name, false, NULL, NULL, cacheIndex);
if ( dependentLib != this )
dyld::warn("DYLD_ setting caused circular dependency in %s\n", this->getPath());
}
@@ -558,9 +733,7 @@
else {
dependentLib->fIsReferencedDownward = true;
}
- LibraryInfo actualInfo = dependentLib->doGetLibraryInfo();
- depLibReRequired = requiredLibInfo.required;
- depLibCheckSumsMatch = ( actualInfo.checksum == requiredLibInfo.info.checksum );
+ LibraryInfo actualInfo = dependentLib->doGetLibraryInfo(requiredLibInfo.info);
depLibReExported = requiredLibInfo.reExported;
if ( ! depLibReExported ) {
// for pre-10.5 binaries that did not use LC_REEXPORT_DYLIB
@@ -568,15 +741,16 @@
}
// 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) ) {
+ if ( (requiredLibInfo.info.minVersion != 0xFFFFFFFF) && (actualInfo.minVersion < requiredLibInfo.info.minVersion)
+ && ((dyld3::MachOFile*)(dependentLib->machHeader()))->enforceCompatVersion() ) {
// 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;
+ //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;
@@ -595,14 +769,23 @@
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);
+ if ( strstr(msg, "Incompatible library version") != NULL )
+ (*context.setErrorStrings)(DYLD_EXIT_REASON_DYLIB_WRONG_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);
+ (*context.setErrorStrings)(DYLD_EXIT_REASON_DYLIB_WRONG_ARCH, this->getPath(), requiredLibInfo.name, NULL);
+ else if ( strstr(msg, "file system sandbox") != NULL )
+ (*context.setErrorStrings)(DYLD_EXIT_REASON_FILE_SYSTEM_SANDBOX, this->getPath(), requiredLibInfo.name, NULL);
+ else if ( strstr(msg, "code signature") != NULL )
+ (*context.setErrorStrings)(DYLD_EXIT_REASON_CODE_SIGNATURE, this->getPath(), requiredLibInfo.name, NULL);
+ else if ( strstr(msg, "malformed") != NULL )
+ (*context.setErrorStrings)(DYLD_EXIT_REASON_MALFORMED_MACHO, this->getPath(), requiredLibInfo.name, NULL);
else
- (*context.setErrorStrings)(dyld_error_kind_dylib_missing, this->getPath(), requiredLibInfo.name, NULL);
- dyld::throwf("Library not loaded: %s\n Referenced from: %s\n Reason: %s", requiredLibInfo.name, this->getRealPath(), msg);
- }
+ (*context.setErrorStrings)(DYLD_EXIT_REASON_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
@@ -615,7 +798,7 @@
for(unsigned int i=0; i < libraryCount(); ++i) {
ImageLoader* dependentImage = libImage(i);
if ( dependentImage != NULL ) {
- dependentImage->recursiveLoadLibraries(context, preflightOnly, thisRPaths);
+ dependentImage->recursiveLoadLibraries(context, preflightOnly, thisRPaths, libraryInfos[i].name);
}
}
@@ -637,6 +820,13 @@
}
}
+}
+
+
+void ImageLoader::recursiveRebaseWithAccounting(const LinkContext& context)
+{
+ this->recursiveRebase(context);
+ vmAccountingSetSuspended(context, false);
}
void ImageLoader::recursiveRebase(const LinkContext& context)
@@ -657,7 +847,7 @@
doRebase(context);
// notify
- context.notifySingle(dyld_image_state_rebased, this);
+ context.notifySingle(dyld_image_state_rebased, this, NULL);
}
catch (const char* msg) {
// this image is not rebased
@@ -693,7 +883,36 @@
}
}
-
+void ImageLoader::recursiveMakeDataReadOnly(const LinkContext& context)
+{
+ if ( ! fMadeReadOnly ) {
+ // break cycles
+ fMadeReadOnly = true;
+
+ try {
+ // handle lower level libraries first
+ for(unsigned int i=0; i < libraryCount(); ++i) {
+ ImageLoader* dependentImage = libImage(i);
+ if ( dependentImage != NULL )
+ dependentImage->recursiveMakeDataReadOnly(context);
+ }
+
+ // if this image has __DATA_CONST, make that segment read-only
+ makeDataReadOnly();
+ }
+ catch (const char* msg) {
+ fMadeReadOnly = false;
+ throw;
+ }
+ }
+}
+
+
+void ImageLoader::recursiveBindWithAccounting(const LinkContext& context, bool forceLazysBound, bool neverUnload)
+{
+ this->recursiveBind(context, forceLazysBound, neverUnload);
+ vmAccountingSetSuspended(context, false);
+}
void ImageLoader::recursiveBind(const LinkContext& context, bool forceLazysBound, bool neverUnload)
{
@@ -721,7 +940,7 @@
if ( neverUnload )
this->setNeverUnload();
- context.notifySingle(dyld_image_state_bound, this);
+ context.notifySingle(dyld_image_state_bound, this, NULL);
}
catch (const char* msg) {
// restore state
@@ -732,39 +951,198 @@
}
}
+
+
+// These are mangled symbols for all the variants of operator new and delete
+// which a main executable can define (non-weak) and override the
+// weak-def implementation in the OS.
+static const char* const sTreatAsWeak[] = {
+ "__Znwm", "__ZnwmRKSt9nothrow_t",
+ "__Znam", "__ZnamRKSt9nothrow_t",
+ "__ZdlPv", "__ZdlPvRKSt9nothrow_t", "__ZdlPvm",
+ "__ZdaPv", "__ZdaPvRKSt9nothrow_t", "__ZdaPvm",
+ "__ZnwmSt11align_val_t", "__ZnwmSt11align_val_tRKSt9nothrow_t",
+ "__ZnamSt11align_val_t", "__ZnamSt11align_val_tRKSt9nothrow_t",
+ "__ZdlPvSt11align_val_t", "__ZdlPvSt11align_val_tRKSt9nothrow_t", "__ZdlPvmSt11align_val_t",
+ "__ZdaPvSt11align_val_t", "__ZdaPvSt11align_val_tRKSt9nothrow_t", "__ZdaPvmSt11align_val_t"
+};
+
+size_t ImageLoader::HashCString::hash(const char* v) {
+ // FIXME: Use hash<string_view> when it has the correct visibility markup
+ return std::hash<std::string_view>{}(v);
+}
+
+bool ImageLoader::EqualCString::equal(const char* s1, const char* s2) {
+ return strcmp(s1, s2) == 0;
+}
+
void ImageLoader::weakBind(const LinkContext& context)
{
+
+ if (!context.useNewWeakBind) {
+ weakBindOld(context);
+ return;
+ }
+
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);
+ unsigned imageIndexes[fgImagesRequiringCoalescing];
+ int count = context.getCoalescedImages(imagesNeedingCoalescing, imageIndexes);
// 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 )
+ if ( ! imagesNeedingCoalescing[i]->weakSymbolsBound(imageIndexes[i]) )
++countNotYetWeakBound;
- if ( imagesNeedingCoalescing[i]->hasCoalescedExports() ) {
- ++countOfImagesWithWeakDefinitions;
- if ( ! imagesNeedingCoalescing[i]->inSharedCache() )
- ++countOfImagesWithWeakDefinitionsNotInSharedCache;
- }
+ 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) ) {
+ if (!context.weakDefMapInitialized) {
+ // Initialize the weak def map as the link context doesn't run static initializers
+ new (&context.weakDefMap) dyld3::Map<const char*, std::pair<const ImageLoader*, uintptr_t>, ImageLoader::HashCString, ImageLoader::EqualCString>();
+ context.weakDefMapInitialized = true;
+ }
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+ // only do alternate algorithm for dlopen(). Use traditional algorithm for launch
+ if ( !context.linkingMainExecutable ) {
+ // Don't take the memory hit of weak defs on the launch path until we hit a dlopen with more weak symbols to bind
+ if (!context.weakDefMapProcessedLaunchDefs) {
+ context.weakDefMapProcessedLaunchDefs = true;
+
+ // Walk the nlist for all binaries from launch and fill in the map with any other weak defs
+ for (int i=0; i < count; ++i) {
+ const ImageLoader* image = imagesNeedingCoalescing[i];
+ // skip images without defs. We've processed launch time refs already
+ if ( !image->hasCoalescedExports() )
+ continue;
+ // Only process binaries which have had their weak symbols bound, ie, not the new ones we are processing now
+ // from this dlopen
+ if ( !image->weakSymbolsBound(imageIndexes[i]) )
+ continue;
+
+ Diagnostics diag;
+ const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*)image->machHeader();
+ ma->forEachWeakDef(diag, ^(const char *symbolName, uintptr_t imageOffset, bool isFromExportTrie) {
+ uintptr_t targetAddr = (uintptr_t)ma + imageOffset;
+ if ( isFromExportTrie ) {
+ // Avoid duplicating the string if we already have the symbol name
+ if ( context.weakDefMap.find(symbolName) != context.weakDefMap.end() )
+ return;
+ symbolName = strdup(symbolName);
+ }
+ context.weakDefMap.insert({ symbolName, { image, targetAddr } });
+ });
+ }
+ }
+
+ // Walk the nlist for all binaries in dlopen and fill in the map with any other weak defs
+ for (int i=0; i < count; ++i) {
+ const ImageLoader* image = imagesNeedingCoalescing[i];
+ if ( image->weakSymbolsBound(imageIndexes[i]) )
+ continue;
+ // skip images without defs. We'll process refs later
+ if ( !image->hasCoalescedExports() )
+ continue;
+ Diagnostics diag;
+ const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*)image->machHeader();
+ ma->forEachWeakDef(diag, ^(const char *symbolName, uintptr_t imageOffset, bool isFromExportTrie) {
+ uintptr_t targetAddr = (uintptr_t)ma + imageOffset;
+ if ( isFromExportTrie ) {
+ // Avoid duplicating the string if we already have the symbol name
+ if ( context.weakDefMap.find(symbolName) != context.weakDefMap.end() )
+ return;
+ symbolName = strdup(symbolName);
+ }
+ context.weakDefMap.insert({ symbolName, { image, targetAddr } });
+ });
+ }
+ // for all images that need weak binding
+ for (int i=0; i < count; ++i) {
+ ImageLoader* imageBeingFixedUp = imagesNeedingCoalescing[i];
+ if ( imageBeingFixedUp->weakSymbolsBound(imageIndexes[i]) )
+ continue; // weak binding already completed
+ bool imageBeingFixedUpInCache = imageBeingFixedUp->inSharedCache();
+
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: checking for weak symbols in %s\n", imageBeingFixedUp->getPath());
+ // for all symbols that need weak binding in this image
+ ImageLoader::CoalIterator coalIterator;
+ imageBeingFixedUp->initializeCoalIterator(coalIterator, i, imageIndexes[i]);
+ while ( !imageBeingFixedUp->incrementCoalIterator(coalIterator) ) {
+ const char* nameToCoalesce = coalIterator.symbolName;
+ uintptr_t targetAddr = 0;
+ const ImageLoader* targetImage;
+ // Seatch the map for a previous definition to use
+ auto weakDefIt = context.weakDefMap.find(nameToCoalesce);
+ if ( (weakDefIt != context.weakDefMap.end()) && (weakDefIt->second.first != nullptr) ) {
+ // Found a previous defition
+ targetImage = weakDefIt->second.first;
+ targetAddr = weakDefIt->second.second;
+ } else {
+ // scan all images looking for definition to use
+ for (int j=0; j < count; ++j) {
+ const ImageLoader* anImage = imagesNeedingCoalescing[j];
+ bool anImageInCache = anImage->inSharedCache();
+ // <rdar://problem/47986398> Don't look at images in dyld cache because cache is
+ // already coalesced. Only images outside cache can potentially override something in cache.
+ if ( anImageInCache && imageBeingFixedUpInCache )
+ continue;
+
+ //dyld::log("looking for %s in %s\n", nameToCoalesce, anImage->getPath());
+ const ImageLoader* foundIn;
+ const Symbol* sym = anImage->findExportedSymbol(nameToCoalesce, false, &foundIn);
+ if ( sym != NULL ) {
+ targetAddr = foundIn->getExportedSymbolAddress(sym, context);
+ targetImage = foundIn;
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: found weak %s at 0x%lX in %s\n", nameToCoalesce, targetAddr, foundIn->getPath());
+ break;
+ }
+ }
+ }
+ if ( (targetAddr != 0) && (coalIterator.image != targetImage) ) {
+ coalIterator.image->updateUsesCoalIterator(coalIterator, targetAddr, (ImageLoader*)targetImage, 0, context);
+ if (weakDefIt == context.weakDefMap.end()) {
+ if (targetImage->neverUnload()) {
+ // Add never unload defs to the map for next time
+ context.weakDefMap.insert({ nameToCoalesce, { targetImage, targetAddr } });
+ if ( context.verboseWeakBind ) {
+ dyld::log("dyld: weak binding adding %s to map\n", nameToCoalesce);
+ }
+ } else {
+ // Add a placeholder for unloadable symbols which makes us fall back to the regular search
+ context.weakDefMap.insert({ nameToCoalesce, { targetImage, targetAddr } });
+ if ( context.verboseWeakBind ) {
+ dyld::log("dyld: weak binding adding unloadable placeholder %s to map\n", nameToCoalesce);
+ }
+ }
+ }
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: adjusting uses of %s in %s to use definition from %s\n", nameToCoalesce, coalIterator.image->getPath(), targetImage->getPath());
+ }
+ }
+ imageBeingFixedUp->setWeakSymbolsBound(imageIndexes[i]);
+ }
+ }
+ else
+#endif // __MAC_OS_X_VERSION_MIN_REQUIRED
+ {
// 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);
+ imagesNeedingCoalescing[i]->initializeCoalIterator(iterators[i], i, imageIndexes[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());
+ dyld::log("dyld: weak bind load order %d/%d for %s\n", i, count, imagesNeedingCoalescing[i]->getIndexedPath(imageIndexes[i]));
}
// walk all symbols keeping iterators in sync by
@@ -797,54 +1175,318 @@
// pick first symbol in load order (and non-weak overrides weak)
uintptr_t targetAddr = 0;
ImageLoader* targetImage = NULL;
+ unsigned targetImageIndex = 0;
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());
+ dyld::log("dyld: weak bind, found %s weak=%d in %s \n", nameToCoalesce, iterators[i].weakSymbol, iterators[i].image->getIndexedPath((unsigned)iterators[i].imageIndex));
if ( iterators[i].weakSymbol ) {
if ( targetAddr == 0 ) {
targetAddr = iterators[i].image->getAddressCoalIterator(iterators[i], context);
- if ( targetAddr != 0 )
+ if ( targetAddr != 0 ) {
targetImage = iterators[i].image;
+ targetImageIndex = (unsigned)iterators[i].imageIndex;
+ }
}
}
else {
targetAddr = iterators[i].image->getAddressCoalIterator(iterators[i], context);
if ( targetAddr != 0 ) {
targetImage = iterators[i].image;
+ targetImageIndex = (unsigned)iterators[i].imageIndex;
// strong implementation found, stop searching
break;
}
}
}
}
- if ( context.verboseWeakBind )
- dyld::log("dyld: weak binding all uses of %s to copy from %s\n", nameToCoalesce, targetImage->getShortName());
-
// 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->getIndexedShortName(targetImageIndex));
+ }
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);
+ 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->getIndexedShortName((unsigned)iterators[i].imageIndex),
+ targetAddr, targetImage->getIndexedShortName(targetImageIndex));
+ }
+ if ( ! iterators[i].image->weakSymbolsBound(imageIndexes[i]) )
+ iterators[i].image->updateUsesCoalIterator(iterators[i], targetAddr, targetImage, targetImageIndex, context);
iterators[i].symbolMatches = false;
}
}
- }
-
- }
- }
-
+ if (targetImage->neverUnload()) {
+ // Add never unload defs to the map for next time
+ context.weakDefMap.insert({ nameToCoalesce, { targetImage, targetAddr } });
+ if ( context.verboseWeakBind ) {
+ dyld::log("dyld: weak binding adding %s to map\n",
+ nameToCoalesce);
+ }
+ }
+ }
+
+ }
+ }
+
+ for (int i=0; i < count; ++i) {
+ if ( imagesNeedingCoalescing[i]->weakSymbolsBound(imageIndexes[i]) )
+ continue; // skip images already processed
+
+ if ( imagesNeedingCoalescing[i]->usesChainedFixups() ) {
+ // during binding of references to weak-def symbols, the dyld cache was patched
+ // but if main executable has non-weak override of operator new or delete it needs is handled here
+ for (const char* weakSymbolName : sTreatAsWeak) {
+ const ImageLoader* dummy;
+ imagesNeedingCoalescing[i]->resolveWeak(context, weakSymbolName, true, false, &dummy);
+ }
+ }
+#if __arm64e__
+ else {
+ // support traditional arm64 app on an arm64e device
+ // look for weak def symbols in this image which may override the cache
+ ImageLoader::CoalIterator coaler;
+ imagesNeedingCoalescing[i]->initializeCoalIterator(coaler, i, 0);
+ imagesNeedingCoalescing[i]->incrementCoalIterator(coaler);
+ while ( !coaler.done ) {
+ const ImageLoader* dummy;
+ // a side effect of resolveWeak() is to patch cache
+ imagesNeedingCoalescing[i]->resolveWeak(context, coaler.symbolName, true, false, &dummy);
+ imagesNeedingCoalescing[i]->incrementCoalIterator(coaler);
+ }
+ }
+#endif
+ }
+
// mark all as having all weak symbols bound
for(int i=0; i < count; ++i) {
- imagesNeedingCoalescing[i]->fWeakSymbolsBound = true;
- }
- }
+ imagesNeedingCoalescing[i]->setWeakSymbolsBound(imageIndexes[i]);
+ }
+ }
+ }
+
uint64_t t2 = mach_absolute_time();
fgTotalWeakBindTime += t2 - t1;
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: weak bind end\n");
+}
+
+
+void ImageLoader::weakBindOld(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];
+ unsigned imageIndexes[fgImagesRequiringCoalescing];
+ int count = context.getCoalescedImages(imagesNeedingCoalescing, imageIndexes);
+
+ // count how many have not already had weakbinding done
+ int countNotYetWeakBound = 0;
+ int countOfImagesWithWeakDefinitionsNotInSharedCache = 0;
+ for(int i=0; i < count; ++i) {
+ if ( ! imagesNeedingCoalescing[i]->weakSymbolsBound(imageIndexes[i]) )
+ ++countNotYetWeakBound;
+ 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) ) {
+#if __MAC_OS_X_VERSION_MIN_REQUIRED
+ // only do alternate algorithm for dlopen(). Use traditional algorithm for launch
+ if ( !context.linkingMainExecutable ) {
+ // for all images that need weak binding
+ for (int i=0; i < count; ++i) {
+ ImageLoader* imageBeingFixedUp = imagesNeedingCoalescing[i];
+ if ( imageBeingFixedUp->weakSymbolsBound(imageIndexes[i]) )
+ continue; // weak binding already completed
+ bool imageBeingFixedUpInCache = imageBeingFixedUp->inSharedCache();
+
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: checking for weak symbols in %s\n", imageBeingFixedUp->getPath());
+ // for all symbols that need weak binding in this image
+ ImageLoader::CoalIterator coalIterator;
+ imageBeingFixedUp->initializeCoalIterator(coalIterator, i, imageIndexes[i]);
+ while ( !imageBeingFixedUp->incrementCoalIterator(coalIterator) ) {
+ const char* nameToCoalesce = coalIterator.symbolName;
+ uintptr_t targetAddr = 0;
+ const ImageLoader* targetImage;
+ // scan all images looking for definition to use
+ for (int j=0; j < count; ++j) {
+ const ImageLoader* anImage = imagesNeedingCoalescing[j];
+ bool anImageInCache = anImage->inSharedCache();
+ // <rdar://problem/47986398> Don't look at images in dyld cache because cache is
+ // already coalesced. Only images outside cache can potentially override something in cache.
+ if ( anImageInCache && imageBeingFixedUpInCache )
+ continue;
+
+ //dyld::log("looking for %s in %s\n", nameToCoalesce, anImage->getPath());
+ const ImageLoader* foundIn;
+ const Symbol* sym = anImage->findExportedSymbol(nameToCoalesce, false, &foundIn);
+ if ( sym != NULL ) {
+ if ( (foundIn->getExportedSymbolInfo(sym) & ImageLoader::kWeakDefinition) == 0 ) {
+ // found non-weak def, use it and stop looking
+ targetAddr = foundIn->getExportedSymbolAddress(sym, context);
+ targetImage = foundIn;
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: found strong %s at 0x%lX in %s\n", nameToCoalesce, targetAddr, foundIn->getPath());
+ break;
+ }
+ else {
+ // found weak-def, only use if no weak found yet
+ if ( targetAddr == 0 ) {
+ targetAddr = foundIn->getExportedSymbolAddress(sym, context);
+ targetImage = foundIn;
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: found weak %s at 0x%lX in %s\n", nameToCoalesce, targetAddr, foundIn->getPath());
+ }
+ }
+ }
+ }
+ if ( (targetAddr != 0) && (coalIterator.image != targetImage) ) {
+ coalIterator.image->updateUsesCoalIterator(coalIterator, targetAddr, (ImageLoader*)targetImage, 0, context);
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: adjusting uses of %s in %s to use definition from %s\n", nameToCoalesce, coalIterator.image->getPath(), targetImage->getPath());
+ }
+ }
+ imageBeingFixedUp->setWeakSymbolsBound(imageIndexes[i]);
+ }
+ }
+ else
+#endif // __MAC_OS_X_VERSION_MIN_REQUIRED
+ {
+ // 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, imageIndexes[i]);
+ sortedIts[i] = &iterators[i];
+ if ( context.verboseWeakBind )
+ dyld::log("dyld: weak bind load order %d/%d for %s\n", i, count, imagesNeedingCoalescing[i]->getIndexedPath(imageIndexes[i]));
+ }
+
+ // 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;
+ unsigned targetImageIndex = 0;
+ 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->getIndexedPath((unsigned)iterators[i].imageIndex));
+ if ( iterators[i].weakSymbol ) {
+ if ( targetAddr == 0 ) {
+ targetAddr = iterators[i].image->getAddressCoalIterator(iterators[i], context);
+ if ( targetAddr != 0 ) {
+ targetImage = iterators[i].image;
+ targetImageIndex = (unsigned)iterators[i].imageIndex;
+ }
+ }
+ }
+ else {
+ targetAddr = iterators[i].image->getAddressCoalIterator(iterators[i], context);
+ if ( targetAddr != 0 ) {
+ targetImage = iterators[i].image;
+ targetImageIndex = (unsigned)iterators[i].imageIndex;
+ // 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->getIndexedShortName(targetImageIndex));
+ }
+ 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->getIndexedShortName((unsigned)iterators[i].imageIndex),
+ targetAddr, targetImage->getIndexedShortName(targetImageIndex));
+ }
+ if ( ! iterators[i].image->weakSymbolsBound(imageIndexes[i]) )
+ iterators[i].image->updateUsesCoalIterator(iterators[i], targetAddr, targetImage, targetImageIndex, context);
+ iterators[i].symbolMatches = false;
+ }
+ }
+ }
+
+ }
+ }
+
+ for (int i=0; i < count; ++i) {
+ if ( imagesNeedingCoalescing[i]->weakSymbolsBound(imageIndexes[i]) )
+ continue; // skip images already processed
+
+ if ( imagesNeedingCoalescing[i]->usesChainedFixups() ) {
+ // during binding of references to weak-def symbols, the dyld cache was patched
+ // but if main executable has non-weak override of operator new or delete it needs is handled here
+ for (const char* weakSymbolName : sTreatAsWeak) {
+ const ImageLoader* dummy;
+ imagesNeedingCoalescing[i]->resolveWeak(context, weakSymbolName, true, false, &dummy);
+ }
+ }
+#if __arm64e__
+ else {
+ // support traditional arm64 app on an arm64e device
+ // look for weak def symbols in this image which may override the cache
+ ImageLoader::CoalIterator coaler;
+ imagesNeedingCoalescing[i]->initializeCoalIterator(coaler, i, 0);
+ imagesNeedingCoalescing[i]->incrementCoalIterator(coaler);
+ while ( !coaler.done ) {
+ const ImageLoader* dummy;
+ // a side effect of resolveWeak() is to patch cache
+ imagesNeedingCoalescing[i]->resolveWeak(context, coaler.symbolName, true, false, &dummy);
+ imagesNeedingCoalescing[i]->incrementCoalIterator(coaler);
+ }
+ }
+#endif
+ }
+
+ // mark all as having all weak symbols bound
+ for(int i=0; i < count; ++i) {
+ imagesNeedingCoalescing[i]->setWeakSymbolsBound(imageIndexes[i]);
+ }
+ }
+ }
+
+ uint64_t t2 = mach_absolute_time();
+ fgTotalWeakBindTime += t2 - t1;
+
if ( context.verboseWeakBind )
dyld::log("dyld: weak bind end\n");
}
@@ -885,13 +1527,16 @@
{
// try to set image's ivar fInitializerRecursiveLock to point to this lock_info
// keep trying until success (spin)
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wdeprecated-declarations"
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);
+#pragma clang diagnostic pop
+ ++(fInitializerRecursiveLock->count);
}
void ImageLoader::recursiveSpinUnLock()
@@ -900,8 +1545,21 @@
fInitializerRecursiveLock = NULL;
}
-
-void ImageLoader::recursiveInitialization(const LinkContext& context, mach_port_t this_thread, InitializerTimingList& timingInfo)
+void ImageLoader::InitializerTimingList::addTime(const char* name, uint64_t time)
+{
+ for (int i=0; i < count; ++i) {
+ if ( strcmp(images[i].shortName, name) == 0 ) {
+ images[i].initTime += time;
+ return;
+ }
+ }
+ images[count].initTime = time;
+ images[count].shortName = name;
+ ++count;
+}
+
+void ImageLoader::recursiveInitialization(const LinkContext& context, mach_port_t this_thread, const char* pathToInitialize,
+ InitializerTimingList& timingInfo, UninitedUpwards& uninitUps)
{
recursive_lock lock_info(this_thread);
recursiveSpinLock(lock_info);
@@ -911,55 +1569,42 @@
// break cycles
fState = dyld_image_state_dependents_initialized-1;
try {
- bool hasUpwards = false;
// 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
- bool isUpward = libIsUpward(i);
- if ( (dependentImage->fDepth >= fDepth) && !isUpward ) {
- dependentImage->recursiveInitialization(context, this_thread, timingInfo);
+ // don't try to initialize stuff "above" me yet
+ if ( libIsUpward(i) ) {
+ uninitUps.imagesAndPaths[uninitUps.count] = { dependentImage, libPath(i) };
+ uninitUps.count++;
}
- hasUpwards |= isUpward;
+ else if ( dependentImage->fDepth >= fDepth ) {
+ dependentImage->recursiveInitialization(context, this_thread, libPath(i), 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);
+ context.notifySingle(dyld_image_state_dependents_initialized, this, &timingInfo);
// initialize this image
bool hasInitializers = this->doInitialization(context);
- // <rdar://problem/10491874> initialize any upward depedencies
- if ( hasUpwards ) {
- for(unsigned int i=0; i < libraryCount(); ++i) {
- ImageLoader* dependentImage = libImage(i);
- // <rdar://problem/10643239> ObjC CG hang
- // only init upward lib here if lib is not downwardly referenced somewhere
- if ( (dependentImage != NULL) && libIsUpward(i) && !dependentImage->isReferencedDownward() ) {
- dependentImage->recursiveInitialization(context, this_thread, timingInfo);
- }
- }
- }
-
// let anyone know we finished initializing this image
fState = dyld_image_state_initialized;
oldState = fState;
- context.notifySingle(dyld_image_state_initialized, this);
+ context.notifySingle(dyld_image_state_initialized, this, NULL);
if ( hasInitializers ) {
uint64_t t2 = mach_absolute_time();
- timingInfo.images[timingInfo.count].image = this;
- timingInfo.images[timingInfo.count].initTime = (t2-t1);
- timingInfo.count++;
+ timingInfo.addTime(this->getShortName(), t2-t1);
}
}
catch (const char* msg) {
@@ -979,21 +1624,26 @@
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 ( mach_timebase_info(&timeBaseInfo) != KERN_SUCCESS )
+ return;
+ sUnitsPerSecond = 1000000000ULL * timeBaseInfo.denom / timeBaseInfo.numer;
}
if ( partTime < sUnitsPerSecond ) {
- uint32_t milliSecondsTimesHundred = (partTime*100000)/sUnitsPerSecond;
- uint32_t milliSeconds = milliSecondsTimesHundred/100;
- uint32_t percentTimesTen = (partTime*1000)/totalTime;
+ 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);
+ if ( milliSeconds >= 100 )
+ dyld::log("%s: %u.%02u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimesHundred-milliSeconds*100, percent, percentTimesTen-percent*10);
+ else if ( milliSeconds >= 10 )
+ dyld::log("%s: %u.%02u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimesHundred-milliSeconds*100, percent, percentTimesTen-percent*10);
+ else
+ dyld::log("%s: %u.%02u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimesHundred-milliSeconds*100, percent, percentTimesTen-percent*10);
}
else {
- uint32_t secondsTimeTen = (partTime*10)/sUnitsPerSecond;
+ uint32_t secondsTimeTen = (uint32_t)((partTime*10)/sUnitsPerSecond);
uint32_t seconds = secondsTimeTen/10;
- uint32_t percentTimesTen = (partTime*1000)/totalTime;
+ 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);
}
@@ -1023,25 +1673,43 @@
void ImageLoader::printStatistics(unsigned int imageCount, const InitializerTimingList& timingInfo)
{
- uint64_t totalTime = fgTotalLoadLibrariesTime + fgTotalRebaseTime + fgTotalBindTime + fgTotalWeakBindTime + fgTotalDOF + fgTotalInitTime;
+ uint64_t totalTime = fgTotalLoadLibrariesTime + fgTotalRebaseTime + fgTotalBindTime + fgTotalWeakBindTime + fgTotalDOF + fgTotalInitTime;
+
+ uint64_t totalDyldTime = totalTime - fgTotalDebuggerPausedTime - fgTotalRebindCacheTime;
+ printTime("Total pre-main time", totalDyldTime, totalDyldTime);
+ printTime(" dylib loading time", fgTotalLoadLibrariesTime-fgTotalDebuggerPausedTime, totalDyldTime);
+ printTime(" rebase/binding time", fgTotalRebaseTime+fgTotalBindTime+fgTotalWeakBindTime-fgTotalRebindCacheTime, totalDyldTime);
+ printTime(" ObjC setup time", fgTotalObjCSetupTime, totalDyldTime);
+ printTime(" initializer time", fgTotalInitTime-fgTotalObjCSetupTime, totalDyldTime);
+ dyld::log(" slowest intializers :\n");
+ for (uintptr_t i=0; i < timingInfo.count; ++i) {
+ uint64_t t = timingInfo.images[i].initTime;
+ if ( t*50 < totalDyldTime )
+ continue;
+ dyld::log("%30s ", timingInfo.images[i].shortName);
+ if ( strncmp(timingInfo.images[i].shortName, "libSystem.", 10) == 0 )
+ t -= fgTotalObjCSetupTime;
+ printTime("", t, totalDyldTime);
+ }
+ dyld::log("\n");
+}
+
+void ImageLoader::printStatisticsDetails(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));
+ printTime(" total time", totalTime, totalTime);
+ dyld::log(" total images loaded: %d (%u from dyld shared cache)\n", imageCount, fgImagesUsedFromSharedCache);
+ dyld::log(" total segments mapped: %u, into %llu pages\n", fgTotalSegmentsMapped, fgTotalBytesMapped/4096);
+ printTime(" total images loading time", fgTotalLoadLibrariesTime, totalTime);
+ printTime(" total load time in ObjC", fgTotalObjCSetupTime, totalTime);
+ printTime(" total debugger pause time", fgTotalDebuggerPausedTime, 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;
@@ -1049,13 +1717,19 @@
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);
+ printTime(" total binding fixups time", fgTotalBindTime, totalTime);
+ printTime(" total weak binding fixups time", fgTotalWeakBindTime, totalTime);
+ printTime(" total redo shared cached bindings time", fgTotalRebindCacheTime, totalTime);
+ dyld::log(" total bindings lazily fixed up: %s of %s\n", commatize(fgTotalLazyBindFixups, commaNum1), commatize(fgTotalPossibleLazyBindFixups, commaNum2));
+ printTime(" total time in initializers and ObjC +load", fgTotalInitTime-fgTotalObjCSetupTime, totalTime);
for (uintptr_t i=0; i < timingInfo.count; ++i) {
- dyld::log("%21s ", timingInfo.images[i].image->getShortName());
- printTime("", timingInfo.images[i].initTime, totalTime);
+ uint64_t t = timingInfo.images[i].initTime;
+ if ( t*1000 < totalTime )
+ continue;
+ dyld::log("%42s ", timingInfo.images[i].shortName);
+ if ( strncmp(timingInfo.images[i].shortName, "libSystem.", 10) == 0 )
+ t -= fgTotalObjCSetupTime;
+ printTime("", t, totalTime);
}
}
@@ -1091,6 +1765,128 @@
}
+//
+// This function is the hotspot of symbol lookup. It was pulled out of findExportedSymbol()
+// to enable it to be re-written in assembler if needed.
+//
+const uint8_t* ImageLoader::trieWalk(const uint8_t* start, const uint8_t* end, const char* s)
+{
+ //dyld::log("trieWalk(%p, %p, %s)\n", start, end, s);
+ ++fgSymbolTrieSearchs;
+ const uint8_t* p = start;
+ while ( p != NULL ) {
+ uintptr_t terminalSize = *p++;
+ if ( terminalSize > 127 ) {
+ // except for re-export-with-rename, all terminal sizes fit in one byte
+ --p;
+ terminalSize = read_uleb128(p, end);
+ }
+ if ( (*s == '\0') && (terminalSize != 0) ) {
+ //dyld::log("trieWalk(%p) returning %p\n", start, p);
+ return p;
+ }
+ const uint8_t* children = p + terminalSize;
+ if ( children > end ) {
+ dyld::log("trieWalk() malformed trie node, terminalSize=0x%lx extends past end of trie\n", terminalSize);
+ return NULL;
+ }
+ //dyld::log("trieWalk(%p) sym=%s, terminalSize=%lu, children=%p\n", start, s, terminalSize, children);
+ uint8_t childrenRemaining = *children++;
+ p = children;
+ uintptr_t nodeOffset = 0;
+ for (; childrenRemaining > 0; --childrenRemaining) {
+ const char* ss = s;
+ //dyld::log("trieWalk(%p) child str=%s\n", start, (char*)p);
+ bool wrongEdge = false;
+ // scan whole edge to get to next edge
+ // if edge is longer than target symbol name, don't read past end of symbol name
+ char c = *p;
+ while ( c != '\0' ) {
+ if ( !wrongEdge ) {
+ if ( c != *ss )
+ wrongEdge = true;
+ ++ss;
+ }
+ ++p;
+ c = *p;
+ }
+ if ( wrongEdge ) {
+ // advance to next child
+ ++p; // skip over zero terminator
+ // skip over uleb128 until last byte is found
+ while ( (*p & 0x80) != 0 )
+ ++p;
+ ++p; // skip over last byte of uleb128
+ if ( p > end ) {
+ dyld::log("trieWalk() malformed trie node, child node extends past end of trie\n");
+ return NULL;
+ }
+ }
+ else {
+ // the symbol so far matches this edge (child)
+ // so advance to the child's node
+ ++p;
+ nodeOffset = read_uleb128(p, end);
+ if ( (nodeOffset == 0) || ( &start[nodeOffset] > end) ) {
+ dyld::log("trieWalk() malformed trie child, nodeOffset=0x%lx out of range\n", nodeOffset);
+ return NULL;
+ }
+ s = ss;
+ //dyld::log("trieWalk() found matching edge advancing to node 0x%lx\n", nodeOffset);
+ break;
+ }
+ }
+ if ( nodeOffset != 0 )
+ p = &start[nodeOffset];
+ else
+ p = NULL;
+ }
+ //dyld::log("trieWalk(%p) return NULL\n", start);
+ return NULL;
+}
+
+
+
+uintptr_t ImageLoader::read_uleb128(const uint8_t*& p, const uint8_t* end)
+{
+ uint64_t result = 0;
+ int bit = 0;
+ do {
+ if (p == end)
+ dyld::throwf("malformed uleb128");
+
+ uint64_t slice = *p & 0x7f;
+
+ if (bit > 63)
+ dyld::throwf("uleb128 too big for uint64, bit=%d, result=0x%0llX", bit, result);
+ else {
+ result |= (slice << bit);
+ bit += 7;
+ }
+ } while (*p++ & 0x80);
+ return (uintptr_t)result;
+}
+
+
+intptr_t ImageLoader::read_sleb128(const uint8_t*& p, const uint8_t* end)
+{
+ int64_t result = 0;
+ int bit = 0;
+ uint8_t byte;
+ do {
+ if (p == end)
+ throw "malformed sleb128";
+ byte = *p++;
+ result |= (((int64_t)(byte & 0x7f)) << bit);
+ bit += 7;
+ } while (byte & 0x80);
+ // sign extend negative numbers
+ if ( (byte & 0x40) != 0 )
+ result |= (~0ULL) << bit;
+ return (intptr_t)result;
+}
+
+
VECTOR_NEVER_DESTRUCTED_IMPL(ImageLoader::InterposeTuple);
VECTOR_NEVER_DESTRUCTED_IMPL(ImagePair);