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--- dyld/dyld-733.6/src/ImageLoader.cpp
+++ dyld/dyld-732.8/src/ImageLoader.cpp
@@ -36,7 +36,6 @@
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <libkern/OSAtomic.h>
-#include <string_view>
#include <atomic>
@@ -969,27 +968,12 @@
"__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];
unsigned imageIndexes[fgImagesRequiringCoalescing];
@@ -1007,65 +991,9 @@
// 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];
@@ -1082,51 +1010,40 @@
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 ) {
+ // 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 weak %s at 0x%lX in %s\n", nameToCoalesce, targetAddr, foundIn->getPath());
+ dyld::log("dyld: found strong %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);
+ 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());
}
@@ -1220,14 +1137,6 @@
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);
- }
- }
}
}
@@ -1272,223 +1181,6 @@
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");
}