]> git.saurik.com Git - apple/dyld.git/blobdiff - src/ImageLoaderMachOClassic.cpp
dyld-635.2.tar.gz
[apple/dyld.git] / src / ImageLoaderMachOClassic.cpp
index 33b055d94bee273ef19a8d5c9a851f3de26d7171..70068cdd12b7dd3c672269ae008cf385dad1b68e 100644 (file)
@@ -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
 #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__
@@ -108,7 +97,8 @@ ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateMainExecutable(cons
        // for PIE record end of program, to know where to start loading dylibs
        if ( slide != 0 )
                fgNextPIEDylibAddress = (uintptr_t)image->getEnd();
-       
+
+       image->disableCoverageCheck();
        image->instantiateFinish(context);
        image->setMapped(context);
 
@@ -137,7 +127,7 @@ ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateMainExecutable(cons
 }
 
 // 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 struct linkedit_data_command* codeSigCmd, const LinkContext& context)
@@ -147,12 +137,12 @@ ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromFile(const char
                // record info about file  
                image->setFileInfo(info.st_dev, info.st_ino, info.st_mtime);
 
-       #if CODESIGNING_SUPPORT
                // if this image is code signed, let kernel validate signature before mapping any pages from image
-               if ( codeSigCmd != NULL )
-                       image->loadCodeSignature(codeSigCmd, fd, offsetInFat);
-       #endif
+               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);
 
@@ -163,11 +153,12 @@ ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromFile(const char
                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);
                }
@@ -205,6 +196,7 @@ ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromCache(const mac
                // 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 ) {
@@ -243,6 +235,8 @@ ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateFromMemory(const ch
                // for compatibility, never unload dylibs loaded from memory
                image->setNeverUnload();
 
+               image->disableCoverageCheck();
+
                // bundle loads need path copied
                if ( moduleName != NULL ) 
                        image->setPath(moduleName);
@@ -286,7 +280,7 @@ ImageLoaderMachOClassic* ImageLoaderMachOClassic::instantiateStart(const macho_h
 void ImageLoaderMachOClassic::instantiateFinish(const LinkContext& context)
 {
        // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
-       this->parseLoadCmds();
+       this->parseLoadCmds(context);
 }
 
 ImageLoaderMachOClassic::~ImageLoaderMachOClassic()
@@ -365,11 +359,11 @@ void ImageLoaderMachOClassic::prefetchLINKEDIT(const LinkContext& context)
                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 ) {
@@ -442,14 +436,14 @@ ImageLoaderMachOClassic::mapSplitSegDylibOutsideSharedRegion(int fd,
        while ( ! foundRoom ) {
                foundRoom = true;
                for(unsigned int i=0; i < regionCount; ++i) {
-                       vm_address_t addr = nextAltLoadAddress + regions[i].sfm_address - regions[0].sfm_address;
-                       vm_size_t size = regions[i].sfm_size ;
+                       vm_address_t addr = (vm_address_t)(nextAltLoadAddress + regions[i].sfm_address - regions[0].sfm_address);
+                       vm_size_t size = (vm_size_t)regions[i].sfm_size ;
                        r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
                        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 = (vm_address_t)(nextAltLoadAddress + regions[j].sfm_address - regions[0].sfm_address);
+                                       size = (vm_size_t)(regions[j].sfm_size);
                                        (void)vm_deallocate(mach_task_self(), addr, size);
                                }
                                nextAltLoadAddress += 0x00100000;  // skip ahead 1MB and try again
@@ -465,7 +459,7 @@ ImageLoaderMachOClassic::mapSplitSegDylibOutsideSharedRegion(int fd,
        }
        
        // map in each region
-       uintptr_t slide = nextAltLoadAddress - regions[0].sfm_address;
+       uintptr_t slide = (uintptr_t)(nextAltLoadAddress - regions[0].sfm_address);
        this->setSlide(slide);
        for(unsigned int i=0; i < regionCount; ++i) {
                if ( ((regions[i].sfm_init_prot & VM_PROT_ZF) != 0) || (regions[i].sfm_size == 0) ) {
@@ -473,7 +467,7 @@ ImageLoaderMachOClassic::mapSplitSegDylibOutsideSharedRegion(int fd,
                }
                else {
                        void* mmapAddress = (void*)(uintptr_t)(regions[i].sfm_address + slide);
-                       size_t size = regions[i].sfm_size;
+                       size_t size = (size_t)regions[i].sfm_size;
                        int protection = 0;
                        if ( regions[i].sfm_init_prot & VM_PROT_EXECUTE )
                                protection   |= PROT_EXEC;
@@ -607,11 +601,13 @@ bool ImageLoaderMachOClassic::isSubframeworkOf(const LinkContext& context, const
                                                        return true;
                                                if ( context.imageSuffix != NULL ) {
                                                        // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
-                                                       char reexportAndSuffix[strlen(context.imageSuffix)+strlen(exportThruName)+1];
-                                                       strcpy(reexportAndSuffix, exportThruName);
-                                                       strcat(reexportAndSuffix, context.imageSuffix);
-                                                       if ( strcmp(&lastSlash[1], reexportAndSuffix) == 0 )
-                                                               return true;
+                                                       for(const char* const* suffix = context.imageSuffix; *suffix != NULL; ++suffix) {
+                                                               char reexportAndSuffix[strlen(*suffix)+strlen(exportThruName)+1];
+                                                               strcpy(reexportAndSuffix, exportThruName);
+                                                               strcat(reexportAndSuffix, *suffix);
+                                                               if ( strcmp(&lastSlash[1], reexportAndSuffix) == 0 )
+                                                                       return true;
+                                                       }
                                                }
                                        }
                                }
@@ -632,7 +628,7 @@ bool ImageLoaderMachOClassic::hasSubLibrary(const LinkContext& context, const Im
                        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
@@ -653,11 +649,13 @@ bool ImageLoaderMachOClassic::hasSubLibrary(const LinkContext& context, const Im
                                                                        return true;
                                                                if ( context.imageSuffix != NULL ) {
                                                                        // when DYLD_IMAGE_SUFFIX is used, childLeafName string needs imageSuffix removed from end
-                                                                       char aSubLibNameAndSuffix[strlen(context.imageSuffix)+strlen(aSubLibName)+1];
-                                                                       strcpy(aSubLibNameAndSuffix, aSubLibName);
-                                                                       strcat(aSubLibNameAndSuffix, context.imageSuffix);
-                                                                       if ( strcmp(aSubLibNameAndSuffix, childLeafName) == 0 )
-                                                                               return true;
+                                                                       for(const char* const* suffix = context.imageSuffix; *suffix != NULL; ++suffix) {
+                                                                               char aSubLibNameAndSuffix[strlen(*suffix)+strlen(aSubLibName)+1];
+                                                                               strcpy(aSubLibNameAndSuffix, aSubLibName);
+                                                                               strcat(aSubLibNameAndSuffix, *suffix);
+                                                                               if ( strcmp(aSubLibNameAndSuffix, childLeafName) == 0 )
+                                                                                       return true;
+                                                                       }
                                                                }
                                                        }
                                                        break;
@@ -686,11 +684,13 @@ bool ImageLoaderMachOClassic::hasSubLibrary(const LinkContext& context, const Im
                                                                        return true;
                                                                if ( context.imageSuffix != NULL ) {
                                                                        // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
-                                                                       char umbrellaAndSuffix[strlen(context.imageSuffix)+strlen(aSubUmbrellaName)+1];
-                                                                       strcpy(umbrellaAndSuffix, aSubUmbrellaName);
-                                                                       strcat(umbrellaAndSuffix, context.imageSuffix);
-                                                                       if ( strcmp(umbrellaAndSuffix, &lastSlash[1]) == 0 )
-                                                                               return true;
+                                                                       for(const char* const* suffix = context.imageSuffix; *suffix != NULL; ++suffix) {
+                                                                               char umbrellaAndSuffix[strlen(*suffix)+strlen(aSubUmbrellaName)+1];
+                                                                               strcpy(umbrellaAndSuffix, aSubUmbrellaName);
+                                                                               strcat(umbrellaAndSuffix, *suffix);
+                                                                               if ( strcmp(umbrellaAndSuffix, &lastSlash[1]) == 0 )
+                                                                                       return true;
+                                                                       }
                                                                }
                                                        }
                                                        break;
@@ -729,39 +729,12 @@ uintptr_t ImageLoaderMachOClassic::getRelocBase()
 }
 
 
-#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)
 {
        // loop through all local (internal) relocation records looking for pre-bound-lazy-pointer values
        const uintptr_t relocBase = this->getRelocBase();
-       register const uintptr_t slide = this->fSlide;
+    const uintptr_t slide = this->fSlide;
        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) {
@@ -770,11 +743,6 @@ void ImageLoaderMachOClassic::resetPreboundLazyPointers(const LinkContext& conte
                        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;
@@ -795,10 +763,9 @@ void ImageLoaderMachOClassic::resetPreboundLazyPointers(const LinkContext& conte
 
 
 
-void ImageLoaderMachOClassic::rebase(const LinkContext& context)
+void ImageLoaderMachOClassic::rebase(const LinkContext& context, uintptr_t slide)
 {
        CRSetCrashLogMessage2(this->getPath());
-       register const uintptr_t slide = this->fSlide;
        const uintptr_t relocBase = this->getRelocBase();
        
        // prefetch any LINKEDIT pages needed
@@ -809,6 +776,7 @@ void ImageLoaderMachOClassic::rebase(const LinkContext& context)
        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);
@@ -823,7 +791,12 @@ void ImageLoaderMachOClassic::rebase(const LinkContext& context)
                                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 ) {
@@ -832,17 +805,13 @@ void ImageLoaderMachOClassic::rebase(const LinkContext& context)
                                else if (reloc->r_length == RELOC_SIZE) {
                                        switch(reloc->r_type) {
                                                case GENERIC_RELOC_VANILLA:
-                                                       *((uintptr_t*)(reloc->r_address + relocBase)) += slide;
-                                                       break;
-                       #if __ppc__
-                                               case PPC_RELOC_HI16: 
-                                               case PPC_RELOC_LO16: 
-                                               case PPC_RELOC_HA16: 
-                                                       // 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
+                                                       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;
-                       #endif
                                                default:
                                                        throw "unknown local relocation type";
                                        }
@@ -857,26 +826,13 @@ void ImageLoaderMachOClassic::rebase(const LinkContext& context)
                                        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;
@@ -932,7 +888,7 @@ const struct macho_nlist* ImageLoaderMachOClassic::binarySearchWithToc(const cha
                noteAccessedLinkEditAddress(pivot);
                noteAccessedLinkEditAddress(pivotStr);
 #endif
-               int cmp = astrcmp(key, pivotStr);
+               int cmp = strcmp(key, pivotStr);
                if ( cmp == 0 )
                        return pivot;
                if ( cmp > 0 ) {
@@ -964,7 +920,7 @@ const struct macho_nlist* ImageLoaderMachOClassic::binarySearch(const char* key,
                noteAccessedLinkEditAddress(pivot);
                noteAccessedLinkEditAddress(pivotStr);
 #endif
-               int cmp = astrcmp(key, pivotStr);
+               int cmp = strcmp(key, pivotStr);
                if ( cmp == 0 )
                        return pivot;
                if ( cmp > 0 ) {
@@ -982,7 +938,7 @@ const struct macho_nlist* ImageLoaderMachOClassic::binarySearch(const char* key,
 }
 
 
-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 )
@@ -1006,7 +962,7 @@ bool ImageLoaderMachOClassic::containsSymbol(const void* addr) const
 }
 
 
-uintptr_t ImageLoaderMachOClassic::exportedSymbolAddress(const LinkContext& context, const Symbol* symbol, bool runResolver) 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;
@@ -1092,7 +1048,7 @@ uintptr_t ImageLoaderMachOClassic::getSymbolAddress(const macho_nlist* sym, cons
 }
 
 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];
@@ -1111,14 +1067,14 @@ uintptr_t ImageLoaderMachOClassic::resolveUndefined(const LinkContext& context,
                }
                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);
                }
@@ -1127,15 +1083,15 @@ uintptr_t ImageLoaderMachOClassic::resolveUndefined(const LinkContext& context,
                        // if reference is weak_import, then it is ok, just return 0
                        return 0;
                }
-               throwSymbolNotFound(context, 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 ( context.coalescedExportFinder(symbolName, &sym, foundIn, nullptr) ) {
+                               if ( *foundIn != this )
+                                       context.addDynamicReference(this, const_cast<ImageLoader*>(*foundIn));
                                return (*foundIn)->getExportedSymbolAddress(sym, context, this);
                        }
                        //throwSymbolNotFound(context, symbolName, this->getPath(), "coalesced namespace");
@@ -1172,7 +1128,7 @@ uintptr_t ImageLoaderMachOClassic::resolveUndefined(const LinkContext& context,
                        if ( context.flatExportFinder(symbolName, &sym, foundIn) )
                                return (*foundIn)->getExportedSymbolAddress(sym, context, this);
                        
-                       throwSymbolNotFound(context, symbolName, this->getPath(), "dynamic lookup");
+                       throwSymbolNotFound(context, symbolName, this->getPath(), "", "dynamic lookup");
                }
                else if ( ord <= libraryCount() ) {
                        target = libImage(ord-1);
@@ -1190,12 +1146,12 @@ uintptr_t ImageLoaderMachOClassic::resolveUndefined(const LinkContext& context,
                        //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, false);
@@ -1206,7 +1162,7 @@ uintptr_t ImageLoaderMachOClassic::resolveUndefined(const LinkContext& context,
                }
                
                // nowhere to be found
-               throwSymbolNotFound(context, symbolName, this->getPath(), target->getPath());
+               throwSymbolNotFound(context, symbolName, this->getPath(), "", target->getPath());
        }
 }
 
@@ -1266,6 +1222,8 @@ void ImageLoaderMachOClassic::doBindExternalRelocations(const LinkContext& conte
                                        {
                                                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__
@@ -1316,7 +1274,7 @@ void ImageLoaderMachOClassic::doBindExternalRelocations(const LinkContext& conte
                                                                // 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;
                                                }
@@ -1456,11 +1414,11 @@ uintptr_t ImageLoaderMachOClassic::doBindLazySymbol(uintptr_t* lazyPointer, cons
                                                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];
                                                        }
                                                }
@@ -1482,7 +1440,7 @@ uintptr_t ImageLoaderMachOClassic::doBindLazySymbol(uintptr_t* lazyPointer, cons
                                                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;
@@ -1498,7 +1456,7 @@ uintptr_t ImageLoaderMachOClassic::doBindLazySymbol(uintptr_t* lazyPointer, cons
 
 
 
-void ImageLoaderMachOClassic::initializeCoalIterator(CoalIterator& it, unsigned int loadOrder)
+void ImageLoaderMachOClassic::initializeCoalIterator(CoalIterator& it, unsigned int loadOrder, unsigned)
 {
        it.image = this;
        it.symbolName = " ";
@@ -1573,7 +1531,7 @@ uintptr_t ImageLoaderMachOClassic::getAddressCoalIterator(CoalIterator& it, cons
                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());
@@ -1589,7 +1547,7 @@ uintptr_t ImageLoaderMachOClassic::getAddressCoalIterator(CoalIterator& it, cons
 }
 
 
-void ImageLoaderMachOClassic::updateUsesCoalIterator(CoalIterator& it, uintptr_t value, ImageLoader* targetImage, const LinkContext& context)
+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
@@ -1608,7 +1566,7 @@ void ImageLoaderMachOClassic::updateUsesCoalIterator(CoalIterator& it, uintptr_t
                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
@@ -1691,7 +1649,7 @@ void ImageLoaderMachOClassic::updateUsesCoalIterator(CoalIterator& it, uintptr_t
                        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, this->imageBaseAddress(), (uintptr_t)location, value, type, symbolName, addend, this->getPath(), targetImage ? targetImage->getPath() : NULL, "weak ", NULL, fSlide);
                        boundSomething = true;
                }
        }
@@ -1718,11 +1676,11 @@ void ImageLoaderMachOClassic::updateUsesCoalIterator(CoalIterator& it, uintptr_t
                                        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
@@ -1737,8 +1695,9 @@ void ImageLoaderMachOClassic::updateUsesCoalIterator(CoalIterator& it, uintptr_t
                }
                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;
@@ -1764,7 +1723,7 @@ void ImageLoaderMachOClassic::bindIndirectSymbolPointers(const LinkContext& cont
                                                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;
@@ -1792,7 +1751,7 @@ void ImageLoaderMachOClassic::bindIndirectSymbolPointers(const LinkContext& cont
                                                }
                                                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
@@ -1844,7 +1803,7 @@ void ImageLoaderMachOClassic::bindIndirectSymbolPointers(const LinkContext& cont
                                                                        // 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
@@ -1885,7 +1844,7 @@ void ImageLoaderMachOClassic::initializeLazyStubs(const LinkContext& context)
                                                        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;
@@ -1899,7 +1858,7 @@ void ImageLoaderMachOClassic::initializeLazyStubs(const LinkContext& context)
                                                                                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);
@@ -2003,19 +1962,12 @@ void ImageLoaderMachOClassic::doInterpose(const LinkContext& context)
                                        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 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);
-                                                       for (uint32_t pointerIndex=0; pointerIndex < pointerCount; ++pointerIndex) {
-                                                               for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
-                                                                       // replace all references to 'replacee' with 'replacement'
-                                                                       if ( (symbolPointers[pointerIndex] == it->replacee) && (this != it->replacementImage) ) {
-                                                                               if ( context.verboseInterposing ) {
-                                                                                       dyld::log("dyld: interposing: at %p replace 0x%lX with 0x%lX in %s\n", 
-                                                                                               &symbolPointers[pointerIndex], it->replacee, it->replacement, this->getPath());
-                                                                               }
-                                                                               symbolPointers[pointerIndex] = it->replacement;
-                                                                       }
-                                                               }
+                                                       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__
@@ -2028,16 +1980,10 @@ void ImageLoaderMachOClassic::doInterpose(const LinkContext& context)
                                                                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;
-                                                                       for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
-                                                                               // replace all references to 'replacee' with 'replacement'
-                                                                               if ( (it->replacee == target) && (this != it->replacementImage) ) {
-                                                                                       if ( context.verboseInterposing ) {
-                                                                                               dyld::log("dyld: interposing: at %p replace JMP 0x%lX with JMP 0x%lX in %s\n", 
-                                                                                                       &entry[1], it->replacee, it->replacement, this->getPath());
-                                                                                       }
-                                                                                       uint32_t newRel32 = it->replacement - (uint32_t)&entry[5];
-                                                                                       *((uint32_t*)&entry[1]) = newRel32; // assume unaligned store of uint32_t is ok
-                                                                               }
+                                                                       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
                                                                        }
                                                                }
                                                        }
@@ -2060,14 +2006,76 @@ void ImageLoaderMachOClassic::doInterpose(const LinkContext& context)
                                case POINTER_RELOC:
                                        {
                                                uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
-                                               for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
+                                               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 == it->replacee) && (this != it->replacementImage) ) {
+                                                       if ( *location == (uintptr_t)context.dynamicInterposeArray[i].replacee ) {
                                                                if ( context.verboseInterposing ) {
-                                                                       dyld::log("dyld: interposing: at %p replace 0x%lX with 0x%lX in %s\n", 
-                                                                               location, it->replacee, it->replacement, this->getPath());
+                                                                       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 = it->replacement;
+                                                               *location = (uintptr_t)context.dynamicInterposeArray[i].replacement;
                                                        }
                                                }
                                        }