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src/ImageLoaderMachOClassic.cpp dyld-132.13 dyld-421.2
--- dyld/dyld-132.13/src/ImageLoaderMachOClassic.cpp
+++ dyld/dyld-421.2/src/ImageLoaderMachOClassic.cpp
@@ -1,6 +1,6 @@
 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
  *
- * Copyright (c) 2004-2008 Apple Inc. All rights reserved.
+ * Copyright (c) 2004-2010 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  * 
@@ -44,9 +44,6 @@
 #include <libkern/OSAtomic.h>
 #include <libkern/OSCacheControl.h>
 
-#if __ppc__ || __ppc64__
-	#include <mach-o/ppc/reloc.h>
-#endif
 #if __x86_64__
 	#include <mach-o/x86_64/reloc.h>
 #endif
@@ -57,16 +54,8 @@
 #include "ImageLoaderMachOClassic.h"
 #include "mach-o/dyld_images.h"
 
-// optimize strcmp for ppc
-#if __ppc__
-	#include <ppc_intrinsics.h>
-#else
-	#define astrcmp(a,b) strcmp(a,b)
-#endif
-
-
 // in dyldStartup.s
-extern "C" void fast_stub_binding_helper_interface();
+extern "C" void stub_binding_helper_i386_old();
 
 
 #if __x86_64__
@@ -106,11 +95,13 @@
 	image->setSlide(slide);
 
 	// for PIE record end of program, to know where to start loading dylibs
-	if ( (mh->flags & MH_PIE) && !context.noPIE )
+	if ( slide != 0 )
 		fgNextPIEDylibAddress = (uintptr_t)image->getEnd();
-	
+
+	image->disableCoverageCheck();
 	image->instantiateFinish(context);
-	
+	image->setMapped(context);
+
 #if __i386__
 	// kernel may have mapped in __IMPORT segment read-only, we need it read/write to do binding
 	if ( image->fReadOnlyImportSegment ) {
@@ -136,45 +127,52 @@
 }
 
 // create image by mapping in a mach-o file
-ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromFile(const char* path, int fd, const uint8_t* fileData, 
+ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromFile(const char* path, int fd, const uint8_t* fileData, size_t lenFileData,
 															uint64_t offsetInFat, uint64_t lenInFat, const struct stat& info, 
-															unsigned int segCount, unsigned int libCount, const LinkContext& context)
+															unsigned int segCount, unsigned int libCount, 
+															const struct linkedit_data_command* codeSigCmd, const LinkContext& context)
 {
 	ImageLoaderMachOClassic* image = ImageLoaderMachOClassic::instantiateStart((macho_header*)fileData, path, segCount, libCount);
 	try {
 		// record info about file  
 		image->setFileInfo(info.st_dev, info.st_ino, info.st_mtime);
 
+		// if this image is code signed, let kernel validate signature before mapping any pages from image
+		image->loadCodeSignature(codeSigCmd, fd, offsetInFat, context);
+		
+		// Validate that first data we read with pread actually matches with code signature
+		image->validateFirstPages(codeSigCmd, fd, fileData, lenFileData, offsetInFat, context);
+
 		// mmap segments
 		image->mapSegmentsClassic(fd, offsetInFat, lenInFat, info.st_size, context);
 
-	#if CODESIGNING_SUPPORT
-		// if this code is signed, validate the signature before accessing any mapped pages
-		image->loadCodeSignature(fileData, fd, offsetInFat);
-	#endif
-		
+		// finish up
+		image->instantiateFinish(context);
+
 		// if path happens to be same as in LC_DYLIB_ID load command use that, otherwise malloc a copy of the path
 		const char* installName = image->getInstallPath();
 		if ( (installName != NULL) && (strcmp(installName, path) == 0) && (path[0] == '/') )
 			image->setPathUnowned(installName);
-		else if ( path[0] != '/' ) {
+		else if ( (path[0] != '/') || (strstr(path, "../") != NULL) ) {
+			// rdar://problem/10733082 Fix up @path based paths during introspection
 			// rdar://problem/5135363 turn relative paths into absolute paths so gdb, Symbolication can later find them
 			char realPath[MAXPATHLEN];
-			if ( realpath(path, realPath) != NULL )
-				image->setPath(realPath);
+			if ( fcntl(fd, F_GETPATH, realPath) == 0 ) 
+				image->setPaths(path, realPath);
 			else
 				image->setPath(path);
 		}
 		else 
 			image->setPath(path);
+
+		// make sure path is stable before recording in dyld_all_image_infos
+		image->setMapped(context);
 
 		// pre-fetch content of __DATA segment for faster launches
 		// don't do this on prebound images or if prefetching is disabled
         if ( !context.preFetchDisabled && !image->isPrebindable())
 			image->preFetchDATA(fd, offsetInFat, context);
 
-		// finish up
-		image->instantiateFinish(context);
 	}
 	catch (...) {
 		// ImageLoader::setMapped() can throw an exception to block loading of image
@@ -187,7 +185,7 @@
 }
 
 // create image by using cached mach-o file
-ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromCache(const macho_header* mh, const char* path, const struct stat& info,
+ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromCache(const macho_header* mh, const char* path, long slide, const struct stat& info,
 																unsigned int segCount, unsigned int libCount, const LinkContext& context)
 {
 	ImageLoaderMachOClassic* image = ImageLoaderMachOClassic::instantiateStart(mh, path, segCount, libCount);
@@ -198,6 +196,7 @@
 		// remember this is from shared cache and cannot be unloaded
 		image->fInSharedCache = true;
 		image->setNeverUnload();
+		image->disableCoverageCheck();
 
 		// segments already mapped in cache
 		if ( context.verboseMapping ) {
@@ -208,6 +207,7 @@
 		}
 
 		image->instantiateFinish(context);
+		image->setMapped(context);
 	}
 	catch (...) {
 		// ImageLoader::setMapped() can throw an exception to block loading of image
@@ -235,11 +235,14 @@
 		// for compatibility, never unload dylibs loaded from memory
 		image->setNeverUnload();
 
+		image->disableCoverageCheck();
+
 		// bundle loads need path copied
 		if ( moduleName != NULL ) 
 			image->setPath(moduleName);
 
 		image->instantiateFinish(context);
+		image->setMapped(context);
 	}
 	catch (...) {
 		// ImageLoader::setMapped() can throw an exception to block loading of image
@@ -277,10 +280,7 @@
 void ImageLoaderMachOClassic::instantiateFinish(const LinkContext& context)
 {
 	// now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
-	this->parseLoadCmds();
-	
-	// notify state change
-	this->setMapped(context);
+	this->parseLoadCmds(context);
 }
 
 ImageLoaderMachOClassic::~ImageLoaderMachOClassic()
@@ -298,8 +298,8 @@
 ImageLoader* ImageLoaderMachOClassic::libImage(unsigned int libIndex) const
 {
 	const uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOClassic) + fSegmentsCount*sizeof(uint32_t)));
-	// mask off low bit
-	return (ImageLoader*)(images[libIndex] & (-2));
+	// mask off low bits
+	return (ImageLoader*)(images[libIndex] & (-4));
 }
 
 bool ImageLoaderMachOClassic::libReExported(unsigned int libIndex) const
@@ -309,13 +309,22 @@
 	return ((images[libIndex] & 1) != 0);
 }	
 
-
-void ImageLoaderMachOClassic::setLibImage(unsigned int libIndex, ImageLoader* image, bool reExported)
+bool ImageLoaderMachOClassic::libIsUpward(unsigned int libIndex) const
+{
+	const uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOClassic) + fSegmentsCount*sizeof(uint32_t)));
+	// upward flag is second bit
+	return ((images[libIndex] & 2) != 0);
+}	
+
+
+void ImageLoaderMachOClassic::setLibImage(unsigned int libIndex, ImageLoader* image, bool reExported, bool upward)
 {
 	uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOClassic) + fSegmentsCount*sizeof(uint32_t)));
 	uintptr_t value = (uintptr_t)image;
 	if ( reExported ) 
 		value |= 1;
+	if ( upward ) 
+		value |= 2;
 	images[libIndex] = value;
 }
 
@@ -350,11 +359,11 @@
 		end += fSymbolTable[fDynamicInfo->iextdefsym+fDynamicInfo->nextdefsym-1].n_un.n_strx;
 		
 	// round to whole pages
-	start = start & (-4096);
-	end = (end + 4095) & (-4096);
+	start = dyld_page_trunc(start);
+	end = dyld_page_round(end);
 	
 	// skip if there is only one page
-	if ( (end-start) > 4096 ) {
+	if ( (end-start) > dyld_page_size ) {
 		madvise((void*)start, end-start, MADV_WILLNEED);
 		fgTotalBytesPreFetched += (end-start);
 		if ( context.verboseMapping ) {
@@ -433,8 +442,8 @@
 			if ( 0 != r ) {
 				// no room here, deallocate what has succeeded so far
 				for(unsigned int j=0; j < i; ++j) {
-					vm_address_t addr = nextAltLoadAddress + regions[j].sfm_address - regions[0].sfm_address;
-					vm_size_t size = regions[j].sfm_size ;
+					addr = nextAltLoadAddress + regions[j].sfm_address - regions[0].sfm_address;
+					size = regions[j].sfm_size ;
 					(void)vm_deallocate(mach_task_self(), addr, size);
 				}
 				nextAltLoadAddress += 0x00100000;  // skip ahead 1MB and try again
@@ -506,9 +515,12 @@
 		return ImageLoaderMachO::mapSegments(fd, offsetInFat, lenInFat, fileLen, context);
 
 #if SPLIT_SEG_SHARED_REGION_SUPPORT	
-	// try to map into shared region at preferred address
-	if ( mapSplitSegDylibInfoSharedRegion(fd, offsetInFat, lenInFat, fileLen, context) == 0) 
-		return;
+	// don't map split-seg dylibs into shared region if shared cache is in use
+	if ( ! context.dyldLoadedAtSameAddressNeededBySharedCache ) {
+		// try to map into shared region at preferred address
+		if ( mapSplitSegDylibInfoSharedRegion(fd, offsetInFat, lenInFat, fileLen, context) == 0) 
+			return;
+	}
 	// if there is a problem, fall into case where we map file somewhere outside the shared region
 #endif
 
@@ -614,7 +626,7 @@
 			const char* lastSlash = strrchr(childInstallPath, '/');
 			if ( lastSlash != NULL ) {
 				const char* firstDot = strchr(lastSlash, '.');
-				int len;
+				size_t len;
 				if ( firstDot == NULL )
 					len = strlen(lastSlash);
 				else
@@ -711,33 +723,6 @@
 }
 
 
-#if __ppc__
-static inline void otherRelocsPPC(uintptr_t* locationToFix, uint8_t relocationType, uint16_t otherHalf, uintptr_t slide)
-{
-	// low 16 bits of 32-bit ppc instructions need fixing
-	struct ppcInstruction { uint16_t opcode; int16_t immediateValue; };
-	ppcInstruction* instruction = (ppcInstruction*)locationToFix;
-	//uint32_t before = *((uint32_t*)locationToFix);
-	switch ( relocationType )
-	{
-		case PPC_RELOC_LO16: 
-			instruction->immediateValue = ((otherHalf << 16) | instruction->immediateValue) + slide;
-			break;
-		case PPC_RELOC_HI16: 
-			instruction->immediateValue = ((((instruction->immediateValue << 16) | otherHalf) + slide) >> 16);
-			break;
-		case PPC_RELOC_HA16: 
-			int16_t signedOtherHalf = (int16_t)(otherHalf & 0xffff);
-			uint32_t temp = (instruction->immediateValue << 16) + signedOtherHalf + slide;
-			if ( (temp & 0x00008000) != 0 )
-				temp += 0x00008000;
-			instruction->immediateValue = temp >> 16;
-	}
-	//uint32_t after = *((uint32_t*)locationToFix);
-	//dyld::log("dyld: ppc fixup %0p type %d from 0x%08X to 0x%08X\n", locationToFix, relocationType, before, after);
-}
-#endif
-
 #if PREBOUND_IMAGE_SUPPORT
 void ImageLoaderMachOClassic::resetPreboundLazyPointers(const LinkContext& context)
 {
@@ -752,11 +737,6 @@
 			if (sreloc->r_length == RELOC_SIZE) {
 				uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
 				switch(sreloc->r_type) {
-		#if __ppc__ 
-					case PPC_RELOC_PB_LA_PTR:
-						*locationToFix = sreloc->r_value + slide;
-						break;
-		#endif
 		#if __i386__
 					case GENERIC_RELOC_PB_LA_PTR:
 						*locationToFix = sreloc->r_value + slide;
@@ -777,9 +757,9 @@
 
 
 
-void ImageLoaderMachOClassic::rebase(const LinkContext& context)
-{
-	register const uintptr_t slide = this->fSlide;
+void ImageLoaderMachOClassic::rebase(const LinkContext& context, uintptr_t slide)
+{
+	CRSetCrashLogMessage2(this->getPath());
 	const uintptr_t relocBase = this->getRelocBase();
 	
 	// prefetch any LINKEDIT pages needed
@@ -790,6 +770,7 @@
 	const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->locreloff]);
 	const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nlocrel];
 	for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+		uintptr_t rebaseAddr;
 		try {
 	#if LINKEDIT_USAGE_DEBUG
 			noteAccessedLinkEditAddress(reloc);
@@ -804,7 +785,12 @@
 				throw "bad local relocation pc_rel";
 			if ( reloc->r_extern != 0 ) 
 				throw "extern relocation found with local relocations";
-			*((uintptr_t*)(reloc->r_address + relocBase)) += slide;
+			rebaseAddr = reloc->r_address + relocBase;
+			if ( ! this->containsAddress((void*)rebaseAddr) )
+				dyld::throwf("local reloc %p not in mapped image\n", (void*)rebaseAddr);
+			*((uintptr_t*)rebaseAddr) += slide;
+			if ( context.verboseRebase )
+				dyld::log("dyld: rebase: %s:*0x%08lX += 0x%08lX\n", this->getShortName(), rebaseAddr, slide);
 		#else	
 			if ( (reloc->r_address & R_SCATTERED) == 0 ) {
 				if ( reloc->r_symbolnum == R_ABS ) {
@@ -813,17 +799,13 @@
 				else if (reloc->r_length == RELOC_SIZE) {
 					switch(reloc->r_type) {
 						case GENERIC_RELOC_VANILLA:
-							*((uintptr_t*)(reloc->r_address + relocBase)) += slide;
+							rebaseAddr = reloc->r_address + relocBase;
+							if ( ! this->containsAddress((void*)rebaseAddr) )
+								dyld::throwf("local reloc %p not in mapped image\n", (void*)rebaseAddr);
+							*((uintptr_t*)rebaseAddr) += slide;
+							if ( context.verboseRebase )
+								dyld::log("dyld: rebase: %s:*0x%08lX += 0x%08lX\n", this->getShortName(), rebaseAddr, slide);
 							break;
-			#if __ppc__
-						case PPC_RELOC_HI16: 
-						case PPC_RELOC_LO16: 
-						case PPC_RELOC_HA16: 
-							// some tools leave object file relocations in linked images
-							otherRelocsPPC((uintptr_t*)(reloc->r_address + relocBase), reloc->r_type, reloc[1].r_address, slide);
-							++reloc; // these relocations come in pairs, skip next
-							break;
-			#endif
 						default:
 							throw "unknown local relocation type";
 					}
@@ -838,26 +820,13 @@
 					uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
 					switch(sreloc->r_type) {
 						case GENERIC_RELOC_VANILLA:
+							if ( ! this->containsAddress((void*)locationToFix) ) 
+								dyld::throwf("local scattered reloc %p not in mapped image\n", locationToFix);
 							*locationToFix += slide;
+							if ( context.verboseRebase )
+								dyld::log("dyld: rebase: %s:*0x%08lX += 0x%08lX\n", this->getShortName(), (uintptr_t)locationToFix, slide);
 							break;
-			#if __ppc__
-						case PPC_RELOC_HI16: 
-						case PPC_RELOC_LO16: 
-						case PPC_RELOC_HA16: 
-							// Metrowerks compiler sometimes leaves object file relocations in linked images???
-							++reloc; // these relocations come in pairs, get next one
-							otherRelocsPPC(locationToFix, sreloc->r_type, reloc->r_address, slide);
-							break;
-						case PPC_RELOC_PB_LA_PTR:
-							// do nothing
-							break;
-			#elif __ppc64__
-						case PPC_RELOC_PB_LA_PTR:
-							// needed for compatibility with ppc64 binaries built with the first ld64
-							// which used PPC_RELOC_PB_LA_PTR relocs instead of GENERIC_RELOC_VANILLA for lazy pointers
-							*locationToFix += slide;
-							break;
-			#elif __i386__
+			#if __i386__
 						case GENERIC_RELOC_PB_LA_PTR:
 							// do nothing
 							break;
@@ -885,6 +854,7 @@
 	
 	// update stats
 	fgTotalRebaseFixups += fDynamicInfo->nlocrel;
+	CRSetCrashLogMessage2(NULL);
 }
 
 
@@ -912,7 +882,7 @@
 		noteAccessedLinkEditAddress(pivot);
 		noteAccessedLinkEditAddress(pivotStr);
 #endif
-		int cmp = astrcmp(key, pivotStr);
+		int cmp = strcmp(key, pivotStr);
 		if ( cmp == 0 )
 			return pivot;
 		if ( cmp > 0 ) {
@@ -944,7 +914,7 @@
 		noteAccessedLinkEditAddress(pivot);
 		noteAccessedLinkEditAddress(pivotStr);
 #endif
-		int cmp = astrcmp(key, pivotStr);
+		int cmp = strcmp(key, pivotStr);
 		if ( cmp == 0 )
 			return pivot;
 		if ( cmp > 0 ) {
@@ -962,7 +932,7 @@
 }
 
 
-const ImageLoader::Symbol* ImageLoaderMachOClassic::findExportedSymbol(const char* name, const ImageLoader** foundIn) const
+const ImageLoader::Symbol* ImageLoaderMachOClassic::findShallowExportedSymbol(const char* name, const ImageLoader** foundIn) const
 {
 	const struct macho_nlist* sym = NULL;
 	if ( fDynamicInfo->tocoff == 0 )
@@ -986,7 +956,7 @@
 }
 
 
-uintptr_t ImageLoaderMachOClassic::exportedSymbolAddress(const Symbol* symbol) const
+uintptr_t ImageLoaderMachOClassic::exportedSymbolAddress(const LinkContext& context, const Symbol* symbol, const ImageLoader* requestor, bool runResolver) const
 {
 	const struct macho_nlist* sym = (macho_nlist*)symbol;
 	uintptr_t result = sym->n_value + fSlide;
@@ -1066,13 +1036,13 @@
 	return false;
 }
 
-uintptr_t ImageLoaderMachOClassic::getSymbolAddress(const macho_nlist* sym, const LinkContext& context) const
-{
-	return ImageLoaderMachO::getSymbolAddress((Symbol*)sym, this, context);
+uintptr_t ImageLoaderMachOClassic::getSymbolAddress(const macho_nlist* sym, const LinkContext& context, bool runResolver) const
+{
+	return ImageLoaderMachO::getSymbolAddress((Symbol*)sym, this, context, runResolver);
 }
 
 uintptr_t ImageLoaderMachOClassic::resolveUndefined(const LinkContext& context, const struct macho_nlist* undefinedSymbol, 
-										bool twoLevel, bool dontCoalesce, const ImageLoader** foundIn)
+										bool twoLevel, bool dontCoalesce, bool runResolver, const ImageLoader** foundIn)
 {
 	++fgTotalBindSymbolsResolved;
 	const char* symbolName = &fStrings[undefinedSymbol->n_un.n_strx];
@@ -1085,20 +1055,20 @@
 		// flat lookup
 		if ( ((undefinedSymbol->n_type & N_PEXT) != 0) && ((undefinedSymbol->n_type & N_TYPE) == N_SECT) ) {
 			// is a multi-module private_extern internal reference that the linker did not optimize away
-			uintptr_t addr = this->getSymbolAddress(undefinedSymbol, context);
+			uintptr_t addr = this->getSymbolAddress(undefinedSymbol, context, false);
 			*foundIn = this;
 			return addr;
 		}
 		const Symbol* sym;
 		if ( context.flatExportFinder(symbolName, &sym, foundIn) ) {
-			if ( (*foundIn != this) && !(*foundIn)->neverUnload() )
-					this->addDynamicReference(*foundIn);
+			if ( *foundIn != this )
+				context.addDynamicReference(this, const_cast<ImageLoader*>(*foundIn));
 			return (*foundIn)->getExportedSymbolAddress(sym, context, this);
 		}
 		// if a bundle is loaded privately the above will not find its exports
 		if ( this->isBundle() && this->hasHiddenExports() ) {
 			// look in self for needed symbol
-			sym = this->findExportedSymbol(symbolName, foundIn);
+			sym = this->findShallowExportedSymbol(symbolName, foundIn);
 			if ( sym != NULL )
 				return (*foundIn)->getExportedSymbolAddress(sym, context, this);
 		}
@@ -1107,25 +1077,25 @@
 			// if reference is weak_import, then it is ok, just return 0
 			return 0;
 		}
-		throwSymbolNotFound(symbolName, this->getPath(), "flat namespace");
+		throwSymbolNotFound(context, symbolName, this->getPath(), "", "flat namespace");
 	}
 	else {
 		// symbol requires searching images with coalesced symbols (not done during prebinding)
 		if ( !context.prebinding && !dontCoalesce && (symbolIsWeakReference(undefinedSymbol) || symbolIsWeakDefinition(undefinedSymbol)) ) {
 			const Symbol* sym;
 			if ( context.coalescedExportFinder(symbolName, &sym, foundIn) ) {
-				if ( (*foundIn != this) && !(*foundIn)->neverUnload() )
-					this->addDynamicReference(*foundIn);
+				if ( *foundIn != this )
+					context.addDynamicReference(this, const_cast<ImageLoader*>(*foundIn));
 				return (*foundIn)->getExportedSymbolAddress(sym, context, this);
 			}
-			//throwSymbolNotFound(symbolName, this->getPath(), "coalesced namespace");
+			//throwSymbolNotFound(context, symbolName, this->getPath(), "coalesced namespace");
 			//dyld::log("dyld: coalesced symbol %s not found in any coalesced image, falling back to two-level lookup", symbolName);
 		}
 		
 		// if this is a real definition (not an undefined symbol) there is no ordinal
 		if ( (undefinedSymbol->n_type & N_TYPE) == N_SECT ) {
 			// static linker should never generate this case, but if it does, do something sane
-			uintptr_t addr = this->getSymbolAddress(undefinedSymbol, context);
+			uintptr_t addr = this->getSymbolAddress(undefinedSymbol, context, false);
 			*foundIn = this;
 			return addr;
 		}
@@ -1152,7 +1122,7 @@
 			if ( context.flatExportFinder(symbolName, &sym, foundIn) )
 				return (*foundIn)->getExportedSymbolAddress(sym, context, this);
 			
-			throwSymbolNotFound(symbolName, this->getPath(), "dynamic lookup");
+			throwSymbolNotFound(context, symbolName, this->getPath(), "", "dynamic lookup");
 		}
 		else if ( ord <= libraryCount() ) {
 			target = libImage(ord-1);
@@ -1170,15 +1140,15 @@
 			//dyld::log("resolveUndefined(%s) in %s\n", symbolName, this->getPath());
 			throw "symbol not found";
 		}
-				
-		const Symbol* sym = target->findExportedSymbol(symbolName, true, foundIn);
-		if ( sym!= NULL ) {
-			return (*foundIn)->getExportedSymbolAddress(sym, context, this);
-		}
-		else if ( (undefinedSymbol->n_type & N_PEXT) != 0 ) {
+
+		uintptr_t address;
+		if ( target->findExportedSymbolAddress(context, symbolName, this, ord, runResolver, foundIn, &address) )
+			return address;
+
+		if ( (undefinedSymbol->n_type & N_PEXT) != 0 ) {
 			// don't know why the static linker did not eliminate the internal reference to a private extern definition
 			*foundIn = this;
-			return this->getSymbolAddress(undefinedSymbol, context);
+			return this->getSymbolAddress(undefinedSymbol, context, false);
 		}
 		else if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
 			// if definition not found and reference is weak return 0
@@ -1186,7 +1156,7 @@
 		}
 		
 		// nowhere to be found
-		throwSymbolNotFound(symbolName, this->getPath(), target->getPath());
+		throwSymbolNotFound(context, symbolName, this->getPath(), "", target->getPath());
 	}
 }
 
@@ -1246,6 +1216,8 @@
 					{
 						const struct macho_nlist* undefinedSymbol = &fSymbolTable[reloc->r_symbolnum];
 						uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
+						if ( ! this->containsAddress((void*)location) )
+							dyld::throwf("external reloc %p not in mapped image %s\n", (void*)location, this->getPath());
 						uintptr_t value = *location;
 						bool symbolAddrCached = true;
 					#if __i386__
@@ -1296,7 +1268,7 @@
 								// range of global symbols.  To handle that case we do the coalesing now.
 								dontCoalesce = false;
 							}
-							symbolAddr = this->resolveUndefined(context, undefinedSymbol, twoLevel, dontCoalesce, &image);
+							symbolAddr = this->resolveUndefined(context, undefinedSymbol, twoLevel, dontCoalesce, false, &image);
 							lastUndefinedSymbol = undefinedSymbol;
 							symbolAddrCached = false;
 						}
@@ -1412,7 +1384,7 @@
 	return targetAddr;
 }
 
-uintptr_t ImageLoaderMachOClassic::doBindFastLazySymbol(uint32_t lazyBindingInfoOffset, const LinkContext& context)
+uintptr_t ImageLoaderMachOClassic::doBindFastLazySymbol(uint32_t lazyBindingInfoOffset, const LinkContext& context, void (*lock)(), void (*unlock)())
 {
 	throw "compressed LINKEDIT lazy binder called with classic LINKEDIT";
 }
@@ -1436,11 +1408,11 @@
 						const uint8_t type = sect->flags & SECTION_TYPE;
 						uint32_t symbolIndex = INDIRECT_SYMBOL_LOCAL;
 						if ( type == S_LAZY_SYMBOL_POINTERS ) {
-							const uint32_t pointerCount = sect->size / sizeof(uintptr_t);
+							const size_t pointerCount = sect->size / sizeof(uintptr_t);
 							uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
 							if ( (lazyPointer >= symbolPointers) && (lazyPointer < &symbolPointers[pointerCount]) ) {
 								const uint32_t indirectTableOffset = sect->reserved1;
-								const uint32_t lazyIndex = lazyPointer - symbolPointers;
+								const size_t lazyIndex = lazyPointer - symbolPointers;
 								symbolIndex = indirectTable[indirectTableOffset + lazyIndex];
 							}
 						}
@@ -1462,7 +1434,7 @@
 						if ( symbolIndex != INDIRECT_SYMBOL_ABS && symbolIndex != INDIRECT_SYMBOL_LOCAL ) {
 							const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
 							const ImageLoader* image = NULL;
-							uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], twoLevel, false, &image);
+							uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], twoLevel, false, true, &image);
 							symbolAddr = this->bindIndirectSymbol(lazyPointer, sect, symbolName, symbolAddr, image,  context);
 							++fgTotalLazyBindFixups;
 							return symbolAddr;
@@ -1478,7 +1450,7 @@
 
 
 
-void ImageLoaderMachOClassic::initializeCoalIterator(CoalIterator& it, unsigned int loadOrder)
+void ImageLoaderMachOClassic::initializeCoalIterator(CoalIterator& it, unsigned int loadOrder, unsigned)
 {
 	it.image = this;
 	it.symbolName = " ";
@@ -1553,15 +1525,23 @@
 		symbol_index = toc[it.curIndex-1].symbol_index;
 	}
 	else {
-		symbol_index = fDynamicInfo->iextdefsym+it.curIndex-1;
+		symbol_index = fDynamicInfo->iextdefsym + (uint32_t)it.curIndex - 1;
 	}	
 	const struct macho_nlist* sym = &fSymbolTable[symbol_index];
 	//dyld::log("getAddressCoalIterator() => 0x%llX, %s symbol_index=%d, in %s\n", (uint64_t)(sym->n_value + fSlide), &fStrings[sym->n_un.n_strx], symbol_index, this->getPath());
+#if __arm__
+		// processor assumes code address with low bit set is thumb
+		if (sym->n_desc & N_ARM_THUMB_DEF)
+			return (sym->n_value | 1) + fSlide ;
+		else
+			return sym->n_value + fSlide;
+#else
 	return sym->n_value + fSlide;
-}
-
-
-void ImageLoaderMachOClassic::updateUsesCoalIterator(CoalIterator& it, uintptr_t value, ImageLoader* targetImage, const LinkContext& context)
+#endif
+}
+
+
+void ImageLoaderMachOClassic::updateUsesCoalIterator(CoalIterator& it, uintptr_t value, ImageLoader* targetImage, unsigned targetIndex, const LinkContext& context)
 {
 	// flat_namespace images with classic LINKEDIT do not need late coalescing.
 	// They still need to be iterated becuase they may implement
@@ -1580,7 +1560,7 @@
 		symbol_index = toc[it.curIndex-1].symbol_index;
 	}
 	else {
-		symbol_index = fDynamicInfo->iextdefsym+it.curIndex-1;
+		symbol_index = fDynamicInfo->iextdefsym + (uint32_t)it.curIndex - 1;
 	}	
 
 	// if this image's copy of the symbol is not a weak definition nor a weak reference then nothing to coalesce here
@@ -1622,7 +1602,7 @@
 			#if __arm__
 						// if weak and thumb subtract off extra thumb bit
 						if ( (undefinedSymbol->n_desc & N_ARM_THUMB_DEF) != 0 )
-							addend += 1;
+							addend &= -2;
 			#endif
 					}
 				} 
@@ -1645,6 +1625,11 @@
 					// to be definition address plus addend
 					//dyld::log("weak def, initialValue=0x%lX, undefAddr=0x%lX\n", initialValue, undefinedSymbol->n_value+fSlide);
 					addend = initialValue - (undefinedSymbol->n_value + fSlide);
+		#if __arm__
+					// if weak and thumb subtract off extra thumb bit
+					if ( (undefinedSymbol->n_desc & N_ARM_THUMB_DEF) != 0 )
+						addend &= -2;
+		#endif
 				}
 				else {
 					// nothing fixed up yet, addend is just initial value
@@ -1658,7 +1643,7 @@
 			if ( reloc->r_pcrel ) 
 				type = BIND_TYPE_TEXT_PCREL32;
 		#endif
-			this->bindLocation(context, (uintptr_t)location, value, targetImage, type, symbolName, addend, "weak ");
+			this->bindLocation(context, (uintptr_t)location, value, type, symbolName, addend, this->getPath(), targetImage ? targetImage->getPath() : NULL, "weak ");
 			boundSomething = true;
 		}
 	}
@@ -1685,11 +1670,11 @@
 					case S_NON_LAZY_SYMBOL_POINTERS:
 					case S_LAZY_SYMBOL_POINTERS:
 					{
-						uint32_t elementCount = sect->size / elementSize;
+						size_t elementCount = sect->size / elementSize;
 						const uint32_t indirectTableOffset = sect->reserved1;
 						uint8_t* ptrToBind = (uint8_t*)(sect->addr + fSlide);
 						//dyld::log(" scanning section %s of %s starting at %p\n", sect->sectname, this->getShortName(), ptrToBind);
-						for (uint32_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
+						for (size_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
 							if ( indirectTable[indirectTableOffset + j] == symbol_index ) {
 								//dyld::log("  found symbol index match at %d/%d, ptrToBind=%p\n", j, elementCount, ptrToBind);
 								// update pointer
@@ -1704,8 +1689,9 @@
 		}
 		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
 	}
-	if ( boundSomething && (targetImage != this) && !targetImage->neverUnload() )
-		this->addDynamicReference(targetImage);
+	if ( boundSomething && (targetImage != this) ) {
+		context.addDynamicReference(this, targetImage);
+	}
 	
 	// mark that this symbol has already been bound, so we don't try to bind again
 	it.type = 1;
@@ -1731,7 +1717,7 @@
 						bool isLazySymbol = false;
 						const uint8_t type = sect->flags & SECTION_TYPE;
 						uint32_t elementSize = sizeof(uintptr_t);
-						uint32_t elementCount = sect->size / elementSize;
+						size_t elementCount = sect->size / elementSize;
 						if ( type == S_NON_LAZY_SYMBOL_POINTERS ) {
 							if ( ! bindNonLazys )
 								continue;
@@ -1759,7 +1745,7 @@
 						}
 						const uint32_t indirectTableOffset = sect->reserved1;
 						uint8_t* ptrToBind = (uint8_t*)(sect->addr + fSlide);
-						for (uint32_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
+						for (size_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
 				#if LINKEDIT_USAGE_DEBUG
 							noteAccessedLinkEditAddress(&indirectTable[indirectTableOffset + j]);
 				#endif
@@ -1811,7 +1797,7 @@
 									// range of global symbols.  To handle that case we do the coalesing now.
 									dontCoalesce = false;
 								}
-								uintptr_t symbolAddr = resolveUndefined(context, sym, twoLevel, dontCoalesce, &image);
+								uintptr_t symbolAddr = resolveUndefined(context, sym, twoLevel, dontCoalesce, false, &image);
 								// update pointer
 								symbolAddr = this->bindIndirectSymbol((uintptr_t*)ptrToBind, sect, &fStrings[sym->n_un.n_strx], symbolAddr, image,  context);
 								// update stats
@@ -1852,7 +1838,7 @@
 							const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
 							uint8_t* start = (uint8_t*)(sect->addr + this->fSlide);
 							uint8_t* end = start + sect->size;
-							uintptr_t dyldHandler = (uintptr_t)&fast_stub_binding_helper_interface;
+							uintptr_t dyldHandler = (uintptr_t)&stub_binding_helper_i386_old;
 							uint32_t entryIndex = 0;
 							for (uint8_t* entry = start; entry < end; entry += 5, ++entryIndex) {
 								bool installLazyHandler = true;
@@ -1866,7 +1852,7 @@
 										const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
 										const ImageLoader* image = NULL;
 										try {
-											uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], this->usesTwoLevelNameSpace(), false, &image);
+											uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], this->usesTwoLevelNameSpace(), false, false, &image);
 											symbolAddr = this->bindIndirectSymbol((uintptr_t*)entry, sect, symbolName, symbolAddr, image, context);
 											++fgTotalBindFixups;
 											uint32_t rel32 = symbolAddr - (((uint32_t)entry)+5);
@@ -1905,6 +1891,7 @@
 
 void ImageLoaderMachOClassic::doBind(const LinkContext& context, bool forceLazysBound)
 {
+	CRSetCrashLogMessage2(this->getPath());
 #if __i386__
 	this->initializeLazyStubs(context);
 #endif
@@ -1918,6 +1905,12 @@
 		// no valid prebinding, so bind symbols.
 		// values bound by name are stored two different ways in classic mach-o:
 		
+	#if TEXT_RELOC_SUPPORT
+		// if there are __TEXT fixups, temporarily make __TEXT writable
+		if ( fTextSegmentBinds ) 
+			this->makeTextSegmentWritable(context, true);
+	#endif
+
 		// 1) external relocations are used for data initialized to external symbols
 		this->doBindExternalRelocations(context);
 		
@@ -1925,10 +1918,17 @@
 		// if this image is in the shared cache, there is no way to reset the lazy pointers, so bind them now
 		this->bindIndirectSymbolPointers(context, true, forceLazysBound || fInSharedCache);
 
+	#if TEXT_RELOC_SUPPORT
+		// if there were __TEXT fixups, restore write protection
+		if ( fTextSegmentBinds ) 
+			this->makeTextSegmentWritable(context, false);
+	#endif	
 	}
 	
 	// set up dyld entry points in image
 	this->setupLazyPointerHandler(context);
+	
+	CRSetCrashLogMessage2(NULL);
 }
 
 void ImageLoaderMachOClassic::doBindJustLazies(const LinkContext& context)
@@ -1936,6 +1936,149 @@
 	// some API called requested that all lazy pointers in this image be force bound
 	this->bindIndirectSymbolPointers(context, false, true);
 }
+
+void ImageLoaderMachOClassic::doInterpose(const LinkContext& context)
+{
+	if ( context.verboseInterposing )
+		dyld::log("dyld: interposing %lu tuples onto: %s\n", fgInterposingTuples.size(), this->getPath());
+
+	// scan indirect symbols
+	const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+	const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_SEGMENT_COMMAND:
+				{
+					const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+					const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+					const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
+					for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+						const uint8_t type = sect->flags & SECTION_TYPE;
+						if ( (type == S_NON_LAZY_SYMBOL_POINTERS) || (type == S_LAZY_SYMBOL_POINTERS) ) {
+							const size_t pointerCount = sect->size / sizeof(uintptr_t);
+							uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
+							for (size_t pointerIndex=0; pointerIndex < pointerCount; ++pointerIndex) {
+								uintptr_t newValue = interposedAddress(context, symbolPointers[pointerIndex], this);
+								if ( newValue != symbolPointers[pointerIndex] )
+									symbolPointers[pointerIndex] = newValue;
+							}
+						}
+				#if __i386__
+						// i386 has special self-modifying stubs that might be prebound to "JMP rel32" that need checking
+						else if ( (type == S_SYMBOL_STUBS) && ((sect->flags & S_ATTR_SELF_MODIFYING_CODE) != 0) && (sect->reserved2 == 5) ) {
+							// check each jmp entry in this section
+							uint8_t* start = (uint8_t*)(sect->addr + this->fSlide);
+							uint8_t* end = start + sect->size;
+							for (uint8_t* entry = start; entry < end; entry += 5) {
+								if ( entry[0] == 0xE9 ) { // 0xE9 == JMP 
+									uint32_t rel32 = *((uint32_t*)&entry[1]); // assume unaligned load of uint32_t is ok
+									uint32_t target = (uint32_t)&entry[5] + rel32;
+									uint32_t newTarget = interposedAddress(context, target, this);
+									if ( newTarget != target ) {
+										uint32_t newRel32 = newTarget - (uint32_t)&entry[5];
+										*((uint32_t*)&entry[1]) = newRel32; // assume unaligned store of uint32_t is ok
+									}
+								}
+							}
+						}
+				#endif
+					}
+				}
+				break;
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+	
+	// scan external relocations 
+	const uintptr_t relocBase = this->getRelocBase();
+	const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
+	const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
+	for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+		if (reloc->r_length == RELOC_SIZE) {
+			switch(reloc->r_type) {
+				case POINTER_RELOC:
+					{
+						uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
+						uintptr_t value = *location;
+						uintptr_t newValue = interposedAddress(context, value, this);
+						if ( newValue != value )
+							*location = newValue;
+					}
+					break;
+			}
+		}
+	}
+}
+
+void ImageLoaderMachOClassic::dynamicInterpose(const LinkContext& context) 
+{
+	if ( context.verboseInterposing )
+		dyld::log("dyld: dynamic interposing %lu tuples onto image: %s\n", context.dynamicInterposeCount, this->getPath());
+
+	// scan indirect symbols
+	const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
+	const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
+	const struct load_command* cmd = cmds;
+	for (uint32_t i = 0; i < cmd_count; ++i) {
+		switch (cmd->cmd) {
+			case LC_SEGMENT_COMMAND:
+				{
+					const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
+					const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
+					const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
+					for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
+						const uint8_t type = sect->flags & SECTION_TYPE;
+						if ( (type == S_NON_LAZY_SYMBOL_POINTERS) || (type == S_LAZY_SYMBOL_POINTERS) ) {
+							const size_t pointerCount = sect->size / sizeof(uintptr_t);
+							uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
+							for (size_t pointerIndex=0; pointerIndex < pointerCount; ++pointerIndex) {
+								for(size_t j=0; j < context.dynamicInterposeCount; ++j) {
+									// replace all references to 'replacee' with 'replacement'
+									if ( symbolPointers[pointerIndex] == (uintptr_t)context.dynamicInterposeArray[j].replacee ) {
+										if ( context.verboseInterposing ) {
+											dyld::log("dyld: dynamic interposing: at %p replace %p with %p in %s\n", 
+												&symbolPointers[pointerIndex], context.dynamicInterposeArray[j].replacee, context.dynamicInterposeArray[j].replacement, this->getPath());
+										}
+										symbolPointers[pointerIndex] = (uintptr_t)context.dynamicInterposeArray[j].replacement;
+									}
+								}
+							}
+						}
+					}
+				}
+				break;
+		}
+		cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
+	}
+	
+	// scan external relocations 
+	const uintptr_t relocBase = this->getRelocBase();
+	const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
+	const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
+	for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
+		if (reloc->r_length == RELOC_SIZE) {
+			switch(reloc->r_type) {
+				case POINTER_RELOC:
+					{
+						uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
+						for(size_t i=0; i < context.dynamicInterposeCount; ++i) {
+							// replace all references to 'replacee' with 'replacement'
+							if ( *location == (uintptr_t)context.dynamicInterposeArray[i].replacee ) {
+								if ( context.verboseInterposing ) {
+									dyld::log("dyld: dynamic interposing: at %p replace %p with %p in %s\n", 
+										location, context.dynamicInterposeArray[i].replacee, context.dynamicInterposeArray[i].replacement, this->getPath());
+								}
+								*location = (uintptr_t)context.dynamicInterposeArray[i].replacement;
+							}
+						}
+					}
+					break;
+			}
+		}
+	}
+}
+
 
 const char* ImageLoaderMachOClassic::findClosestSymbol(const void* addr, const void** closestAddr) const
 {
@@ -1970,7 +2113,14 @@
 		}
 	}
 	if ( bestSymbol != NULL ) {
+#if __arm__
+		if (bestSymbol->n_desc & N_ARM_THUMB_DEF)
+			*closestAddr = (void*)((bestSymbol->n_value | 1) + fSlide);
+		else
+			*closestAddr = (void*)(bestSymbol->n_value + fSlide);
+#else
 		*closestAddr = (void*)(bestSymbol->n_value + fSlide);
+#endif
 		return &fStrings[bestSymbol->n_un.n_strx];
 	}
 	return NULL;