]> git.saurik.com Git - apple/dyld.git/blobdiff - launch-cache/update_dyld_shared_cache.cpp
dyld-239.4.tar.gz
[apple/dyld.git] / launch-cache / update_dyld_shared_cache.cpp
index ac9cc1ccc006a8be19b2a00e3d8b5e5dda11bb25..73cb11474a2a83cc4fcda9e68d7ecfbb0daa8bbf 100644 (file)
@@ -31,7 +31,9 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <math.h>
 #include <fcntl.h>
+#include <dlfcn.h>
 #include <signal.h>
 #include <errno.h>
 #include <sys/uio.h>
 #include <servers/bootstrap.h>
 #include <mach-o/loader.h>
 #include <mach-o/fat.h>
+#include <CoreFoundation/CoreFoundation.h>
+#include <Security/Security.h>
+#include <Security/SecCodeSigner.h>
+#include <CommonCrypto/CommonDigest.h>
 
 #include "dyld_cache_format.h"
 
 #include <vector>
 #include <set>
 #include <map>
-#include <ext/hash_map>
+#include <unordered_map>
 
 #include "Architectures.hpp"
 #include "MachOLayout.hpp"
 #include "MachORebaser.hpp"
 #include "MachOBinder.hpp"
 #include "CacheFileAbstraction.hpp"
+#include "dyld_cache_config.h"
 
 #define SELOPT_WRITE
 #include "objc-shared-cache.h"
 
-#define FIRST_DYLIB_TEXT_OFFSET 0x7000
-#define FIRST_DYLIB_DATA_OFFSET 0x1000
+#define FIRST_DYLIB_TEXT_OFFSET 0x8000
 
 #ifndef LC_FUNCTION_STARTS
     #define LC_FUNCTION_STARTS 0x26
@@ -95,15 +101,27 @@ static void warn(const char *arch, const char *format, ...)
 }
 
 
-static uint64_t pageAlign(uint64_t addr) { return ( (addr + 4095) & (-4096) ); }
+class CStringHash {
+public:
+       size_t operator()(const char* __s) const {
+               size_t __h = 0;
+               for ( ; *__s; ++__s)
+                       __h = 5 * __h + *__s;
+               return __h;
+       };
+};
+class CStringEquals
+{
+public:
+       bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); }
+};
+
+
 
 class ArchGraph
 {
 public:
-       struct CStringEquals {
-               bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); }
-       };
-       typedef __gnu_cxx::hash_map<const char*, const char*, __gnu_cxx::hash<const char*>, CStringEquals> StringToString;
+       typedef std::unordered_map<const char*, const char*, CStringHash, CStringEquals> StringToString;
 
        static void                     addArchPair(ArchPair ap);
        static void                     addRoot(const char* vpath, const std::set<ArchPair>& archs);
@@ -140,7 +158,7 @@ private:
                std::set<DependencyNode*>                                       fRootsDependentOnThis;
        };
 
-       typedef __gnu_cxx::hash_map<const char*, class DependencyNode*, __gnu_cxx::hash<const char*>, CStringEquals> PathToNode;
+       typedef std::unordered_map<const char*, class DependencyNode*, CStringHash, CStringEquals> PathToNode;
 
 
                                                                ArchGraph(ArchPair ap) : fArchPair(ap) {}
@@ -325,12 +343,25 @@ ArchGraph::DependencyNode* ArchGraph::getNode(const char* path)
                //fprintf(stderr, "adding %s node alias %s for %s\n", archName(fArchPair), node->getLayout()->getID().name, realPath);
                pos = fNodes.find(node->getLayout()->getID().name);
                if ( pos != fNodes.end() ) {
-                       // <rdar://problem/8305479> warn if two dylib in cache have same install_name
-                       char* msg;
-                       asprintf(&msg, "update_dyld_shared_cache: warning, found two dylibs with same install path: %s\n\t%s\n\t%s\n", 
-                                                                       node->getLayout()->getID().name, pos->second->getPath(), node->getPath());
-                       fprintf(stderr, "%s", msg);
-                       warnings.push_back(msg);
+                       // get uuids of two dylibs to see if this is accidental copy of a dylib or two differnent dylibs with same -install_name
+                       uuid_t uuid1;
+                       uuid_t uuid2;
+                       node->getLayout()->uuid(uuid1);
+                       pos->second->getLayout()->uuid(uuid2);
+                       if ( memcmp(&uuid1, &uuid2, 16) == 0 ) {
+                               // <rdar://problem/8305479> warn if two dylib in cache have same install_name
+                               char* msg;
+                               asprintf(&msg, "update_dyld_shared_cache: warning, found two copies of the same dylib with same install path: %s\n\t%s\n\t%s\n", 
+                                                                               node->getLayout()->getID().name, pos->second->getPath(), node->getPath());
+                               fprintf(stderr, "%s", msg);
+                               warnings.push_back(msg);
+                       }
+                       else {
+                               // <rdar://problem/12763450> update_dyld_shared_cache should fail if two images have same install name
+                               fprintf(stderr, "update_dyld_shared_cache: found two different dylibs with same install path: %s\n\t%s\n\t%s\n", 
+                                                       node->getLayout()->getID().name, pos->second->getPath(), node->getPath());
+                               exit(1);
+                       }
                }
                else
                        fNodes[node->getLayout()->getID().name] = node;
@@ -508,6 +539,8 @@ const char* ArchGraph::archName(ArchPair ap)
                                        return "armv7f";
                                case CPU_SUBTYPE_ARM_V7K:
                                        return "armv7k";
+                               case CPU_SUBTYPE_ARM_V7S:
+                                       return "armv7s";
                                default:
                                        return "arm";
                        }
@@ -595,6 +628,82 @@ bool ArchGraph::canBeShared(const MachOLayoutAbstraction* layout, ArchPair ap, c
 }
 
 
+
+class StringPool
+{
+public:
+                               StringPool();
+       const char*     getBuffer();
+       uint32_t        size();
+       uint32_t        add(const char* str);
+       uint32_t        addUnique(const char* str);
+       const char* stringAtIndex(uint32_t) const;
+private:
+       typedef std::unordered_map<const char*, uint32_t, CStringHash, CStringEquals> StringToOffset;
+
+       char*                   fBuffer;
+       uint32_t                fBufferAllocated;
+       uint32_t                fBufferUsed;
+       StringToOffset  fUniqueStrings;
+};
+
+
+StringPool::StringPool() 
+       : fBufferUsed(0), fBufferAllocated(48*1024*1024)
+{
+       fBuffer = (char*)malloc(fBufferAllocated);
+}
+
+uint32_t StringPool::add(const char* str)
+{
+       uint32_t len = strlen(str);
+       if ( (fBufferUsed + len + 1) > fBufferAllocated ) {
+               // grow buffer
+               throw "string buffer exhausted";
+       }
+       strcpy(&fBuffer[fBufferUsed], str);
+       uint32_t result = fBufferUsed;
+       fUniqueStrings[&fBuffer[fBufferUsed]] = result;
+       fBufferUsed += len+1;
+       return result;
+}
+
+uint32_t StringPool::addUnique(const char* str)
+{
+       StringToOffset::iterator pos = fUniqueStrings.find(str);
+       if ( pos != fUniqueStrings.end() ) 
+               return pos->second;
+       else {
+               //fprintf(stderr, "StringPool::addUnique() new string: %s\n", str);
+               return this->add(str);
+       }
+}
+
+uint32_t StringPool::size()
+{
+       return fBufferUsed;
+}
+
+const char*    StringPool::getBuffer()
+{
+       return fBuffer;
+}
+
+const char* StringPool::stringAtIndex(uint32_t index) const
+{
+       return &fBuffer[index];
+}
+
+
+
+struct LocalSymbolInfo
+{
+       uint32_t        dylibOffset;
+       uint32_t        nlistStartIndex;
+       uint32_t        nlistCount;
+};
+
+
 template <typename A>
 class SharedCache
 {
@@ -602,7 +711,7 @@ public:
                                                        SharedCache(ArchGraph* graph, const char* rootPath, const char* overlayPath, const char* cacheDir, bool explicitCacheDir,
                                                                                        bool alphaSort, bool verify, bool optimize, uint64_t dyldBaseAddress);
        bool                                    update(bool force, bool optimize, bool deleteExistingFirst, int archIndex, 
-                                                                               int archCount, bool keepSignatures);
+                                                                               int archCount, bool keepSignatures, bool dontMapLocalSymbols);
        static const char*              cacheFileSuffix(bool optimized, const char* archName);
 
     // vm address = address AS WRITTEN into the cache
@@ -622,18 +731,19 @@ private:
 
        bool                                    notUpToDate(const char* path, unsigned int aliasCount);
        bool                                    notUpToDate(const void* cache, unsigned int aliasCount);
-       uint8_t*                                optimizeLINKEDIT(bool keepSignatures);
+       uint8_t*                                optimizeLINKEDIT(bool keepSignatures, bool dontMapLocalSymbols);
        void                                    optimizeObjC(std::vector<void*>& pointersInData);
 
        static void                             getSharedCacheBasAddresses(cpu_type_t arch, uint64_t* baseReadOnly, uint64_t* baseWritable);
        static cpu_type_t               arch();
-       static uint64_t                 sharedRegionReadOnlyStartAddress();
-       static uint64_t                 sharedRegionWritableStartAddress();
-       static uint64_t                 sharedRegionReadOnlySize();
-       static uint64_t                 sharedRegionWritableSize();
+       static uint64_t                 sharedRegionStartAddress();
+       static uint64_t                 sharedRegionSize();
+       static uint64_t                 sharedRegionStartWritableAddress(uint64_t);
+       static uint64_t                 sharedRegionStartReadOnlyAddress(uint64_t, uint64_t);
        static uint64_t                 getWritableSegmentNewAddress(uint64_t proposedNewAddress, uint64_t originalAddress, uint64_t executableSlide);
        static bool                             addCacheSlideInfo();
        
+       static uint64_t                 pageAlign(uint64_t addr);
        void                                    assignNewBaseAddresses(bool verify);
 
        struct LayoutInfo {
@@ -695,6 +805,9 @@ private:
        std::vector<LayoutInfo>                         fDylibs;
        std::vector<LayoutInfo>                         fDylibAliases;
        std::vector<shared_file_mapping_np>     fMappings;
+       std::vector<macho_nlist<P> >            fUnmappedLocalSymbols;
+       StringPool                                                      fUnmappedLocalsStringPool;
+       std::vector<LocalSymbolInfo>            fLocalSymbolInfos;
        uint32_t                                                        fHeaderSize;
     uint8_t*                                                   fInMemoryCache;
        uint64_t                                                        fDyldBaseAddress;
@@ -718,6 +831,7 @@ private:
        uint32_t                                                        fOffsetOfDataInCodeInCombinedLinkedit;
        uint32_t                                                        fSizeOfDataInCodeInCombinedLinkedit;
        uint32_t                                                        fLinkEditsTotalOptimizedSize;
+       uint32_t                                                        fUnmappedLocalSymbolsSize;
 };
 
 
@@ -814,21 +928,21 @@ template <>        cpu_type_t     SharedCache<x86>::arch()        { return CPU_TYPE_I386; }
 template <>     cpu_type_t     SharedCache<x86_64>::arch()     { return CPU_TYPE_X86_64; }
 template <>     cpu_type_t     SharedCache<arm>::arch()        { return CPU_TYPE_ARM; }
 
-template <>     uint64_t       SharedCache<x86>::sharedRegionReadOnlyStartAddress()    { return 0x90000000; }
-template <>     uint64_t       SharedCache<x86_64>::sharedRegionReadOnlyStartAddress() { return 0x7FFF80000000LL; }
-template <>     uint64_t       SharedCache<arm>::sharedRegionReadOnlyStartAddress()    { return 0x30000000; }
+template <>     uint64_t       SharedCache<x86>::sharedRegionStartAddress()                    { return 0x90000000; }
+template <>     uint64_t       SharedCache<x86_64>::sharedRegionStartAddress()                 { return 0x7FFF80000000LL; }
+template <>     uint64_t       SharedCache<arm>::sharedRegionStartAddress()                    { return ARM_SHARED_REGION_START; }
 
-template <>     uint64_t       SharedCache<x86>::sharedRegionWritableStartAddress()    { return 0xAC000000; }
-template <>     uint64_t       SharedCache<x86_64>::sharedRegionWritableStartAddress() { return 0x7FFF70000000LL; }
-template <>     uint64_t       SharedCache<arm>::sharedRegionWritableStartAddress()    { return 0x3E000000; }
+template <>     uint64_t       SharedCache<x86>::sharedRegionSize()                                    { return 0x20000000; }
+template <>     uint64_t       SharedCache<x86_64>::sharedRegionSize()                                 { return 0x40000000; }
+template <>     uint64_t       SharedCache<arm>::sharedRegionSize()                                    { return ARM_SHARED_REGION_SIZE; }
 
-template <>     uint64_t       SharedCache<x86>::sharedRegionReadOnlySize()                    { return 0x1C000000; }
-template <>     uint64_t       SharedCache<x86_64>::sharedRegionReadOnlySize()                 { return 0x40000000; }
-template <>     uint64_t       SharedCache<arm>::sharedRegionReadOnlySize()                    { return 0x0E000000; }
+template <>     uint64_t       SharedCache<x86>::sharedRegionStartWritableAddress(uint64_t exEnd)                      { return exEnd + 0x04000000; }
+template <>     uint64_t       SharedCache<x86_64>::sharedRegionStartWritableAddress(uint64_t exEnd)           { return 0x7FFF70000000LL; }
+template <>     uint64_t       SharedCache<arm>::sharedRegionStartWritableAddress(uint64_t exEnd)                      { return (exEnd + 16383) & (-16384); }
 
-template <>     uint64_t       SharedCache<x86>::sharedRegionWritableSize()                    { return 0x04000000; }
-template <>     uint64_t       SharedCache<x86_64>::sharedRegionWritableSize()                 { return 0x10000000; }
-template <>     uint64_t       SharedCache<arm>::sharedRegionWritableSize()                    { return 0x02000000; }
+template <>     uint64_t       SharedCache<x86>::sharedRegionStartReadOnlyAddress(uint64_t wrEnd, uint64_t exEnd)       { return wrEnd + 0x04000000; }
+template <>     uint64_t       SharedCache<x86_64>::sharedRegionStartReadOnlyAddress(uint64_t wrEnd, uint64_t exEnd){ return exEnd; }
+template <>     uint64_t       SharedCache<arm>::sharedRegionStartReadOnlyAddress(uint64_t wrEnd, uint64_t exEnd)       { return (wrEnd + 16383) & (-16384); }
 
 
 template <>     const char*    SharedCache<x86>::archName()    { return "i386"; }
@@ -839,6 +953,12 @@ template <>         const char*    SharedCache<x86>::cacheFileSuffix(bool, const char* arc
 template <>     const char*    SharedCache<x86_64>::cacheFileSuffix(bool, const char* archName){ return archName; }
 template <>     const char*    SharedCache<arm>::cacheFileSuffix(bool, const char* archName)   { return archName; }
 
+
+template <>  uint64_t          SharedCache<x86>::pageAlign(uint64_t addr)    { return ( (addr + 4095) & (-4096) ); }
+template <>  uint64_t          SharedCache<x86_64>::pageAlign(uint64_t addr) { return ( (addr + 4095) & (-4096) ); }
+template <>  uint64_t          SharedCache<arm>::pageAlign(uint64_t addr)    { return ( (addr + 4095) & (-4096) ); }
+
+
 template <typename A>
 SharedCache<A>::SharedCache(ArchGraph* graph, const char* rootPath, const char* overlayPath, const char* cacheDir, bool explicitCacheDir, bool alphaSort, bool verify, bool optimize, uint64_t dyldBaseAddress) 
   : fArchGraph(graph), fVerify(verify), fExistingIsNotUpToDate(true), 
@@ -851,7 +971,8 @@ SharedCache<A>::SharedCache(ArchGraph* graph, const char* rootPath, const char*
        fOffsetOfOldIndirectSymbolsInCombinedLinkedit(0), fSizeOfOldIndirectSymbolsInCombinedLinkedit(0),
        fOffsetOfOldStringPoolInCombinedLinkedit(0), fSizeOfOldStringPoolInCombinedLinkedit(0),
        fOffsetOfFunctionStartsInCombinedLinkedit(0), fSizeOfFunctionStartsInCombinedLinkedit(0),
-       fOffsetOfDataInCodeInCombinedLinkedit(0), fSizeOfDataInCodeInCombinedLinkedit(0)
+       fOffsetOfDataInCodeInCombinedLinkedit(0), fSizeOfDataInCodeInCombinedLinkedit(0),
+       fUnmappedLocalSymbolsSize(0)
 {
        if ( fArchGraph->getArchPair().arch != arch() )
                throwf("SharedCache object is wrong architecture: 0x%08X vs 0x%08X", fArchGraph->getArchPair().arch, arch());
@@ -950,6 +1071,7 @@ SharedCache<A>::SharedCache(ArchGraph* graph, const char* rootPath, const char*
        fHeaderSize = sizeof(dyld_cache_header) 
                                                        + fMappings.size()*sizeof(shared_file_mapping_np) 
                                                        + (fDylibs.size()+aliasCount)*sizeof(dyld_cache_image_info);
+       const uint64_t baseHeaderSize = fHeaderSize;
        //fprintf(stderr, "aliasCount=%d, fHeaderSize=0x%08X\n", aliasCount, fHeaderSize);
        // build list of aliases and compute where each ones path string will go
        for(typename std::vector<struct LayoutInfo>::const_iterator it = fDylibs.begin(); it != fDylibs.end(); ++it) {
@@ -973,21 +1095,21 @@ SharedCache<A>::SharedCache(ArchGraph* graph, const char* rootPath, const char*
                // if no existing cache, say so
                if ( fExistingCacheForVerification == NULL ) {
                        throwf("update_dyld_shared_cache[%u] for arch=%s, could not verify because cache file does not exist in /var/db/dyld/\n",
-                        getpid(), archName());
+                        getpid(), fArchGraph->archName());
                }
                const dyldCacheHeader<E>* header = (dyldCacheHeader<E>*)fExistingCacheForVerification;
                const dyldCacheImageInfo<E>* cacheEntry = (dyldCacheImageInfo<E>*)(fExistingCacheForVerification + header->imagesOffset());
                for(typename std::vector<LayoutInfo>::iterator it = fDylibs.begin(); it != fDylibs.end(); ++it, ++cacheEntry) {
                        if ( cacheEntry->address() != it->layout->getSegments()[0].newAddress() ) {
                                throwf("update_dyld_shared_cache[%u] warning: for arch=%s, could not verify cache because start address of %s is 0x%llX in cache, but should be 0x%llX\n",
-                                                       getpid(), archName(), it->layout->getID().name, cacheEntry->address(), it->layout->getSegments()[0].newAddress());
+                                                       getpid(), fArchGraph->archName(), it->layout->getID().name, cacheEntry->address(), it->layout->getSegments()[0].newAddress());
                        }
                }
        }
        
        
        if ( fHeaderSize > FIRST_DYLIB_TEXT_OFFSET )
-               throwf("header size miscalculation 0x%08X", fHeaderSize);
+               throwf("header size overflow: allowed=0x%08X, base=0x%08llX, aliases=0x%08llX", FIRST_DYLIB_TEXT_OFFSET, baseHeaderSize, fHeaderSize-baseHeaderSize);
 }
 
 
@@ -1001,131 +1123,80 @@ uint64_t SharedCache<A>::getWritableSegmentNewAddress(uint64_t proposedNewAddres
 template <typename A>
 void SharedCache<A>::assignNewBaseAddresses(bool verify)
 {
-       uint64_t sharedCacheStartAddress = sharedRegionReadOnlyStartAddress();
-#if 0
-       if ( arch() == CPU_TYPE_X86_64 ) {
-               if ( verify ) {
-                       if ( fExistingCacheForVerification == NULL ) {
-                               throwf("update_dyld_shared_cache[%u] for arch=%s, could not verify because cache file does not exist in /var/db/dyld/\n",
-                                          getpid(), archName());
-                       }
-                       const dyldCacheHeader<E>* header = (dyldCacheHeader<E>*)fExistingCacheForVerification;
-                       const dyldCacheFileMapping<E>* mappings = (dyldCacheFileMapping<E>*)(fExistingCacheForVerification + header->mappingOffset());
-                       sharedCacheStartAddress = mappings[0].address();
-               }
-               else {
-                       // <rdar://problem/5274722> dyld shared cache can be more random
-                       uint64_t readOnlySize = 0;
-                       for(typename std::vector<LayoutInfo>::iterator it = fDylibs.begin(); it != fDylibs.end(); ++it) {
-                               if ( ! it->layout->hasSplitSegInfo() )
-                                       continue;
-                               std::vector<MachOLayoutAbstraction::Segment>& segs = ((MachOLayoutAbstraction*)(it->layout))->getSegments();
-                               for (int i=0; i < segs.size(); ++i) {
-                                       MachOLayoutAbstraction::Segment& seg = segs[i];
-                                       if ( ! seg.writable() )
-                                               readOnlySize += pageAlign(seg.size());
-                               }
+       // first layout TEXT for dylibs
+       const uint64_t startExecuteAddress = sharedRegionStartAddress();
+       uint64_t currentExecuteAddress = startExecuteAddress + FIRST_DYLIB_TEXT_OFFSET; 
+       for(typename std::vector<LayoutInfo>::iterator it = fDylibs.begin(); it != fDylibs.end(); ++it) {
+               std::vector<MachOLayoutAbstraction::Segment>& segs = ((MachOLayoutAbstraction*)(it->layout))->getSegments();
+               for (int i=0; i < segs.size(); ++i) {
+                       MachOLayoutAbstraction::Segment& seg = segs[i];
+                       seg.reset();
+                       if ( seg.executable() && !seg.writable() ) {
+                               // __TEXT segment
+                               if ( it->info.address == 0 )
+                                       it->info.address = currentExecuteAddress;
+                               seg.setNewAddress(currentExecuteAddress);
+                               currentExecuteAddress += pageAlign(seg.size());
                        }
-                       uint64_t maxSlide = sharedRegionReadOnlySize() - (readOnlySize + FIRST_DYLIB_TEXT_OFFSET);
-                       sharedCacheStartAddress = sharedRegionReadOnlyStartAddress() + pageAlign(arc4random() % maxSlide);
                }
        }
-#endif
-       uint64_t currentExecuteAddress = sharedCacheStartAddress + FIRST_DYLIB_TEXT_OFFSET;     
-       uint64_t currentWritableAddress = sharedRegionWritableStartAddress() + FIRST_DYLIB_DATA_OFFSET;
 
-       // first layout TEXT and DATA for dylibs
+       // layout DATA for dylibs
+       const uint64_t startWritableAddress = sharedRegionStartWritableAddress(currentExecuteAddress);
+       uint64_t currentWritableAddress = startWritableAddress;
        for(typename std::vector<LayoutInfo>::iterator it = fDylibs.begin(); it != fDylibs.end(); ++it) {
                std::vector<MachOLayoutAbstraction::Segment>& segs = ((MachOLayoutAbstraction*)(it->layout))->getSegments();
-               MachOLayoutAbstraction::Segment* executableSegment = NULL;
                for (int i=0; i < segs.size(); ++i) {
                        MachOLayoutAbstraction::Segment& seg = segs[i];
                        seg.reset();
                        if ( seg.writable() ) {
-                               if ( seg.executable() && it->layout->hasSplitSegInfo() ) {
-                                       // skip __IMPORT segments in this pass
-                               }
-                               else {
-                                       // __DATA segment
-                                       if (  it->layout->hasSplitSegInfo() ) {
-                                               if ( executableSegment == NULL )
-                                                       throwf("first segment in dylib is not executable for %s", it->layout->getID().name);
-                                               seg.setNewAddress(getWritableSegmentNewAddress(currentWritableAddress, seg.address(), executableSegment->newAddress() - executableSegment->address()));
-                                       }
-                                       else
-                                               seg.setNewAddress(currentWritableAddress);
-                                       currentWritableAddress = pageAlign(seg.newAddress() + seg.size());
-                               }
-                       }
-                       else {
-                               if ( seg.executable() ) {
-                                       // __TEXT segment
-                                       if ( it->info.address == 0 )
-                                               it->info.address = currentExecuteAddress;
-                                       executableSegment = &seg;
-                                       seg.setNewAddress(currentExecuteAddress);
-                                       currentExecuteAddress += pageAlign(seg.size());
-                               }
-                               else {
-                                       // skip read-only segments in this pass
-                               }
+                               if ( seg.executable() ) 
+                                       throw "found writable and executable segment";
+                               // __DATA segment
+                               seg.setNewAddress(currentWritableAddress);
+                               currentWritableAddress = pageAlign(seg.newAddress() + seg.size());
                        }
                }
        }
 
-       // append all read-only (but not LINKEDIT) segments at end of all TEXT segments
-       // append all IMPORT segments at end of all DATA segments rounded to next 2MB 
-       uint64_t currentReadOnlyAddress = currentExecuteAddress;
-       uint64_t startWritableExecutableAddress = (currentWritableAddress + 0x200000 - 1) & (-0x200000);
-       uint64_t currentWritableExecutableAddress = startWritableExecutableAddress;
+       // layout all read-only (but not LINKEDIT) segments
+       const uint64_t startReadOnlyAddress = sharedRegionStartReadOnlyAddress(currentWritableAddress, currentExecuteAddress);
+       uint64_t currentReadOnlyAddress = startReadOnlyAddress;
        for(typename std::vector<LayoutInfo>::iterator it = fDylibs.begin(); it != fDylibs.end(); ++it) {
                std::vector<MachOLayoutAbstraction::Segment>& segs = ((MachOLayoutAbstraction*)(it->layout))->getSegments();
                for(int i=0; i < segs.size(); ++i) {
                        MachOLayoutAbstraction::Segment& seg = segs[i];
-                       if ( !seg.writable() && !seg.executable() && (strcmp(seg.name(), "__LINKEDIT") != 0) ) {
-                               // allocate non-executable,read-only segments from end of read only shared region
+                       if ( seg.readable() && !seg.writable() && !seg.executable() && (strcmp(seg.name(), "__LINKEDIT") != 0) ) {
+                               // __UNICODE segment
                                seg.setNewAddress(currentReadOnlyAddress);
                                currentReadOnlyAddress += pageAlign(seg.size());
                        }
-                       else if ( seg.writable() && seg.executable() && it->layout->hasSplitSegInfo() ) {
-                               // allocate IMPORT segments to end of writable shared region
-                               seg.setNewAddress(currentWritableExecutableAddress);
-                               currentWritableExecutableAddress += pageAlign(seg.size());
-                       }
                }
        }       
 
-       // append all LINKEDIT segments at end of all read-only segments
+       // layout all LINKEDIT segments at end of all read-only segments
        fLinkEditsStartAddress = currentReadOnlyAddress;
        fFirstLinkEditSegment = NULL;
        for(typename std::vector<LayoutInfo>::iterator it = fDylibs.begin(); it != fDylibs.end(); ++it) {
                std::vector<MachOLayoutAbstraction::Segment>& segs = ((MachOLayoutAbstraction*)(it->layout))->getSegments();
                for(int i=0; i < segs.size(); ++i) {
                        MachOLayoutAbstraction::Segment& seg = segs[i];
-                       if ( !seg.writable() && !seg.executable() && (strcmp(seg.name(), "__LINKEDIT") == 0) ) {
+                       if ( seg.readable() && !seg.writable() && !seg.executable() && (strcmp(seg.name(), "__LINKEDIT") == 0) ) {
                                if ( fFirstLinkEditSegment == NULL ) 
                                        fFirstLinkEditSegment = &seg;
-                               // allocate non-executable,read-only segments from end of read only shared region
                                seg.setNewAddress(currentReadOnlyAddress);
                                currentReadOnlyAddress += pageAlign(seg.size());
                        }
                }
        }
-       fLinkEditsTotalUnoptimizedSize = (currentReadOnlyAddress - fLinkEditsStartAddress + 4095) & (-4096);
-
-    // <rdar://problem/9361288> i386 dyld shared cache overflows after adding libclh.dylib
-       if ( (currentReadOnlyAddress -  sharedRegionReadOnlyStartAddress()) > sharedRegionReadOnlySize() )
-               throwf("read-only slice of cache too big: %lluMB (max %lluMB)", 
-                               (currentReadOnlyAddress -  sharedRegionReadOnlyStartAddress())/(1024*1024),
-                          sharedRegionReadOnlySize()/(1024*1024));
-               
+       fLinkEditsTotalUnoptimizedSize = pageAlign(currentReadOnlyAddress - fLinkEditsStartAddress);
 
        // populate large mappings
        uint64_t cacheFileOffset = 0;
-       if ( currentExecuteAddress > sharedCacheStartAddress + FIRST_DYLIB_TEXT_OFFSET ) {
+       if ( currentExecuteAddress > startExecuteAddress ) {
                shared_file_mapping_np  executeMapping;
-               executeMapping.sfm_address              = sharedCacheStartAddress;
-               executeMapping.sfm_size                 = currentExecuteAddress - sharedCacheStartAddress;
+               executeMapping.sfm_address              = startExecuteAddress;
+               executeMapping.sfm_size                 = currentExecuteAddress - startExecuteAddress;
                executeMapping.sfm_file_offset  = cacheFileOffset;
                executeMapping.sfm_max_prot             = VM_PROT_READ | VM_PROT_EXECUTE;
                executeMapping.sfm_init_prot    = VM_PROT_READ | VM_PROT_EXECUTE;
@@ -1133,29 +1204,18 @@ void SharedCache<A>::assignNewBaseAddresses(bool verify)
                cacheFileOffset += executeMapping.sfm_size;
                
                shared_file_mapping_np  writableMapping;
-               writableMapping.sfm_address             = sharedRegionWritableStartAddress();
-               writableMapping.sfm_size                = currentWritableAddress - sharedRegionWritableStartAddress();
+               writableMapping.sfm_address             = startWritableAddress;
+               writableMapping.sfm_size                = currentWritableAddress - startWritableAddress;
                writableMapping.sfm_file_offset = cacheFileOffset;
                writableMapping.sfm_max_prot    = VM_PROT_READ | VM_PROT_WRITE;
                writableMapping.sfm_init_prot   = VM_PROT_READ | VM_PROT_WRITE;
                fMappings.push_back(writableMapping);
                cacheFileOffset += writableMapping.sfm_size;
-               
-               if ( currentWritableExecutableAddress > startWritableExecutableAddress ) {
-                       shared_file_mapping_np  writableExecutableMapping;
-                       writableExecutableMapping.sfm_address   = startWritableExecutableAddress;
-                       writableExecutableMapping.sfm_size              = currentWritableExecutableAddress - startWritableExecutableAddress;
-                       writableExecutableMapping.sfm_file_offset= cacheFileOffset;
-                       writableExecutableMapping.sfm_max_prot  = VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
-                       writableExecutableMapping.sfm_init_prot = VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE; 
-                       fMappings.push_back(writableExecutableMapping);
-                       cacheFileOffset += writableExecutableMapping.sfm_size;
-               }
-               
+                               
                // make read-only (contains LINKEDIT segments) last, so it can be cut back when optimized
                shared_file_mapping_np  readOnlyMapping;
-               readOnlyMapping.sfm_address             = currentExecuteAddress;
-               readOnlyMapping.sfm_size                = currentReadOnlyAddress - currentExecuteAddress;
+               readOnlyMapping.sfm_address             = startReadOnlyAddress;
+               readOnlyMapping.sfm_size                = currentReadOnlyAddress - startReadOnlyAddress;
                readOnlyMapping.sfm_file_offset = cacheFileOffset;
                readOnlyMapping.sfm_max_prot    = VM_PROT_READ;
                readOnlyMapping.sfm_init_prot   = VM_PROT_READ;
@@ -1165,7 +1225,7 @@ void SharedCache<A>::assignNewBaseAddresses(bool verify)
        else {
                // empty cache
                shared_file_mapping_np  cacheHeaderMapping;
-               cacheHeaderMapping.sfm_address          = sharedRegionWritableStartAddress();
+               cacheHeaderMapping.sfm_address          = startExecuteAddress;
                cacheHeaderMapping.sfm_size                     = FIRST_DYLIB_TEXT_OFFSET;
                cacheHeaderMapping.sfm_file_offset      = cacheFileOffset;
                cacheHeaderMapping.sfm_max_prot         = VM_PROT_READ;
@@ -1322,7 +1382,7 @@ bool SharedCache<A>::notUpToDate(const char* path, unsigned int aliasCount)
        struct stat stat_buf;
        ::fstat(fd, &stat_buf);
     uint32_t cacheFileSize = stat_buf.st_size;
-    uint32_t cacheAllocatedSize = (cacheFileSize + 4095) & (-4096);
+    uint32_t cacheAllocatedSize = pageAlign(cacheFileSize);
     uint8_t* mappingAddr = NULL;
        if ( vm_allocate(mach_task_self(), (vm_address_t*)(&mappingAddr), cacheAllocatedSize, VM_FLAGS_ANYWHERE) != KERN_SUCCESS )
         throwf("can't vm_allocate cache of size %u", cacheFileSize);
@@ -1348,76 +1408,6 @@ bool SharedCache<A>::notUpToDate(const char* path, unsigned int aliasCount)
        return result;
 }
 
-class CStringEquals
-{
-public:
-       bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); }
-};
-
-class StringPool
-{
-public:
-                               StringPool();
-       const char*     getBuffer();
-       uint32_t        size();
-       uint32_t        add(const char* str);
-       uint32_t        addUnique(const char* str);
-       const char* stringAtIndex(uint32_t) const;
-private:
-       typedef __gnu_cxx::hash_map<const char*, uint32_t, __gnu_cxx::hash<const char*>, CStringEquals> StringToOffset;
-
-       char*                   fBuffer;
-       uint32_t                fBufferAllocated;
-       uint32_t                fBufferUsed;
-       StringToOffset  fUniqueStrings;
-};
-
-
-StringPool::StringPool() 
-       : fBufferUsed(0), fBufferAllocated(32*1024*1024)
-{
-       fBuffer = (char*)malloc(fBufferAllocated);
-}
-
-uint32_t StringPool::add(const char* str)
-{
-       uint32_t len = strlen(str);
-       if ( (fBufferUsed + len + 1) > fBufferAllocated ) {
-               // grow buffer
-               throw "string buffer exhausted";
-       }
-       strcpy(&fBuffer[fBufferUsed], str);
-       uint32_t result = fBufferUsed;
-       fUniqueStrings[&fBuffer[fBufferUsed]] = result;
-       fBufferUsed += len+1;
-       return result;
-}
-
-uint32_t StringPool::addUnique(const char* str)
-{
-       StringToOffset::iterator pos = fUniqueStrings.find(str);
-       if ( pos != fUniqueStrings.end() ) 
-               return pos->second;
-       else {
-               //fprintf(stderr, "StringPool::addUnique() new string: %s\n", str);
-               return this->add(str);
-       }
-}
-
-uint32_t StringPool::size()
-{
-       return fBufferUsed;
-}
-
-const char*    StringPool::getBuffer()
-{
-       return fBuffer;
-}
-
-const char* StringPool::stringAtIndex(uint32_t index) const
-{
-       return &fBuffer[index];
-}
 
 
 template <typename A>
@@ -1431,7 +1421,10 @@ public:
                void                                                            copyWeakBindInfo(uint32_t&);
                void                                                            copyLazyBindInfo(uint32_t&);
                void                                                            copyExportInfo(uint32_t&);
-               void                                                            copyLocalSymbols(uint32_t symbolTableOffset, uint32_t&);
+               void                                                            copyLocalSymbols(uint32_t symbolTableOffset, uint32_t&, bool dontMapLocalSymbols,
+                                                                                                                       uint8_t* cacheStart, StringPool& unmappedLocalsStringPool, 
+                                                                                                                       std::vector<macho_nlist<typename A::P> >& unmappedSymbols,
+                                                                                                                       std::vector<LocalSymbolInfo>& info);
                void                                                            copyExportedSymbols(uint32_t symbolTableOffset, uint32_t&);
                void                                                            copyImportedSymbols(uint32_t symbolTableOffset, uint32_t&);
                void                                                            copyExternalRelocations(uint32_t& offset);
@@ -1482,6 +1475,8 @@ private:
        uint32_t                                                                        fIndirectSymbolTableOffsetInfoNewLinkEdit;
        uint32_t                                                                        fFunctionStartsOffsetInNewLinkEdit;
        uint32_t                                                                        fDataInCodeOffsetInNewLinkEdit;
+       uint32_t                                                                        fUnmappedLocalSymbolsStartIndexInNewLinkEdit;
+       uint32_t                                                                        fUnmappedLocalSymbolsCountInNewLinkEdit;
 };
 
 
@@ -1500,7 +1495,8 @@ LinkEditOptimizer<A>::LinkEditOptimizer(const MachOLayoutAbstraction& layout, co
        fExportedSymbolsStartIndexInNewLinkEdit(0), fExportedSymbolsCountInNewLinkEdit(0),
        fImportSymbolsStartIndexInNewLinkEdit(0), fImportedSymbolsCountInNewLinkEdit(0),
        fExternalRelocationsOffsetIntoNewLinkEdit(0), fIndirectSymbolTableOffsetInfoNewLinkEdit(0),
-       fFunctionStartsOffsetInNewLinkEdit(0), fDataInCodeOffsetInNewLinkEdit(0)
+       fFunctionStartsOffsetInNewLinkEdit(0), fDataInCodeOffsetInNewLinkEdit(0),
+       fUnmappedLocalSymbolsStartIndexInNewLinkEdit(0), fUnmappedLocalSymbolsCountInNewLinkEdit(0)
        
 {
        fHeader = (const macho_header<P>*)fLayout.getSegments()[0].mappedAddress();
@@ -1609,25 +1605,46 @@ void LinkEditOptimizer<A>::copyExportInfo(uint32_t& offset)
 }
 
 
-
 template <typename A>
-void LinkEditOptimizer<A>::copyLocalSymbols(uint32_t symbolTableOffset, uint32_t& symbolIndex)
+void LinkEditOptimizer<A>::copyLocalSymbols(uint32_t symbolTableOffset, uint32_t& symbolIndex, bool dontMapLocalSymbols, uint8_t* cacheStart, 
+                                                                                       StringPool&     unmappedLocalsStringPool, std::vector<macho_nlist<P> >& unmappedSymbols,
+                                                                                       std::vector<LocalSymbolInfo>& dylibInfos)
 {
        fLocalSymbolsStartIndexInNewLinkEdit = symbolIndex;
+       LocalSymbolInfo localInfo;
+       localInfo.dylibOffset = ((uint8_t*)fHeader) - cacheStart;
+       localInfo.nlistStartIndex = unmappedSymbols.size();
+       localInfo.nlistCount = 0;
        fSymbolTableStartOffsetInNewLinkEdit = symbolTableOffset + symbolIndex*sizeof(macho_nlist<P>);
        macho_nlist<P>* const newSymbolTableStart = (macho_nlist<P>*)(fNewLinkEditStart+symbolTableOffset);
        const macho_nlist<P>* const firstLocal = &fSymbolTable[fDynamicSymbolTable->ilocalsym()];
        const macho_nlist<P>* const lastLocal  = &fSymbolTable[fDynamicSymbolTable->ilocalsym()+fDynamicSymbolTable->nlocalsym()];
        uint32_t oldIndex = fDynamicSymbolTable->ilocalsym();
        for (const macho_nlist<P>* entry = firstLocal; entry < lastLocal; ++entry, ++oldIndex) {
-               if ( (entry->n_type() & N_TYPE) == N_SECT ) {
+               // <rdar://problem/12237639> don't copy stab symbols
+               if ( (entry->n_sect() != NO_SECT) && ((entry->n_type() & N_STAB) == 0) ) {
+                       const char* name = &fStrings[entry->n_strx()];
                        macho_nlist<P>* newSymbolEntry = &newSymbolTableStart[symbolIndex];
                        *newSymbolEntry = *entry;
-                       newSymbolEntry->set_n_strx(fNewStringPool.addUnique(&fStrings[entry->n_strx()]));
-                       ++symbolIndex;
+                       if ( dontMapLocalSymbols ) {
+                               // if local in __text, add <redacted> symbol name to shared cache so backtraces don't have bogus names
+                               if ( entry->n_sect() == 1 ) {
+                                       newSymbolEntry->set_n_strx(fNewStringPool.addUnique("<redacted>"));
+                                       ++symbolIndex;
+                               }
+                               // copy local symbol to unmmapped locals area
+                               unmappedSymbols.push_back(*entry);                      
+                               unmappedSymbols.back().set_n_strx(unmappedLocalsStringPool.addUnique(name));
+                       }
+                       else {
+                               newSymbolEntry->set_n_strx(fNewStringPool.addUnique(name));
+                               ++symbolIndex;
+                       }
                }
        }
        fLocalSymbolsCountInNewLinkEdit = symbolIndex - fLocalSymbolsStartIndexInNewLinkEdit;
+       localInfo.nlistCount = unmappedSymbols.size() - localInfo.nlistStartIndex;
+       dylibInfos.push_back(localInfo);
        //fprintf(stderr, "%u locals starting at %u for %s\n", fLocalSymbolsCountInNewLinkEdit, fLocalSymbolsStartIndexInNewLinkEdit, fLayout.getFilePath());
 }
 
@@ -1870,7 +1887,7 @@ void LinkEditOptimizer<A>::updateLoadCommands(uint64_t newVMAddress, uint64_t si
 
 
 template <typename A>
-uint8_t* SharedCache<A>::optimizeLINKEDIT(bool keepSignatures)
+uint8_t* SharedCache<A>::optimizeLINKEDIT(bool keepSignatures, bool dontMapLocalSymbols)
 {
        // allocate space for optimized LINKEDIT area
        uint8_t* newLinkEdit = new uint8_t[fLinkEditsTotalUnoptimizedSize];
@@ -1916,8 +1933,11 @@ uint8_t* SharedCache<A>::optimizeLINKEDIT(bool keepSignatures)
        fOffsetOfOldSymbolTableInfoInCombinedLinkedit = offset;
        uint32_t symbolTableOffset = offset;
        uint32_t symbolTableIndex = 0;
+       if ( dontMapLocalSymbols ) 
+               fUnmappedLocalSymbols.reserve(16384);
        for(typename std::vector<LinkEditOptimizer<A>*>::iterator it = optimizers.begin(); it != optimizers.end(); ++it) {
-               (*it)->copyLocalSymbols(symbolTableOffset, symbolTableIndex);
+               (*it)->copyLocalSymbols(symbolTableOffset, symbolTableIndex, dontMapLocalSymbols, fInMemoryCache,
+                                                               fUnmappedLocalsStringPool, fUnmappedLocalSymbols, fLocalSymbolInfos);
                (*it)->copyExportedSymbols(symbolTableOffset, symbolTableIndex);
                (*it)->copyImportedSymbols(symbolTableOffset, symbolTableIndex);
        }
@@ -1958,11 +1978,11 @@ uint8_t* SharedCache<A>::optimizeLINKEDIT(bool keepSignatures)
        fSizeOfOldStringPoolInCombinedLinkedit = stringPool.size();
        
        // total new size round up to page size
-       fLinkEditsTotalOptimizedSize = (fOffsetOfOldStringPoolInCombinedLinkedit + fSizeOfOldStringPoolInCombinedLinkedit + 4095) & (-4096);
+       fLinkEditsTotalOptimizedSize = pageAlign(fOffsetOfOldStringPoolInCombinedLinkedit + fSizeOfOldStringPoolInCombinedLinkedit);
        
        // choose new linkedit file offset 
        uint32_t linkEditsFileOffset = cacheFileOffsetForVMAddress(fLinkEditsStartAddress);
-//     uint32_t linkEditsFileOffset = fLinkEditsStartAddress - sharedRegionReadOnlyStartAddress();     
+//     uint32_t linkEditsFileOffset = fLinkEditsStartAddress - sharedRegionStartAddress();     
 
        // update load commands so that all dylibs shared different areas of the same LINKEDIT segment
        for(typename std::vector<LinkEditOptimizer<A>*>::iterator it = optimizers.begin(); it != optimizers.end(); ++it) {
@@ -2315,6 +2335,69 @@ static void cleanup(int sig)
 }
 
 
+// <rdar://problem/10730767> update_dyld_shared_cache should use sync_volume_np() instead of sync() 
+static void sync_volume(const char* volumePath)
+{
+#if __MAC_OS_X_VERSION_MIN_REQUIRED >= 1080
+       int error = sync_volume_np(volumePath, SYNC_VOLUME_FULLSYNC|SYNC_VOLUME_FULLSYNC);
+#else
+       int full_sync = 3; // SYNC_VOLUME_FULLSYNC | SYNC_VOLUME_FULLSYNC
+       int error = 0;
+       if ( fsctl(volumePath, 0x80004101 /*FSCTL_SYNC_VOLUME*/, &full_sync, 0) == -1) 
+               error = errno;
+#endif
+       if ( error )
+               ::sync();
+}
+
+
+// <rdar://problem/12552226> update shared cache should sign the shared cache
+static bool adhoc_codesign_share_cache(const char* path)
+{
+       CFURLRef target = ::CFURLCreateFromFileSystemRepresentation(NULL, (const UInt8 *)path, strlen(path), FALSE);
+       if ( target == NULL )
+               return false;
+
+       SecStaticCodeRef code;
+       OSStatus status = ::SecStaticCodeCreateWithPath(target, kSecCSDefaultFlags, &code);
+       CFRelease(target);
+       if ( status ) {
+               ::fprintf(stderr, "codesign: failed to create url to signed object\n");
+               return false;
+       }
+
+       const void * keys[1] = { (void *)kSecCodeSignerIdentity } ;
+       const void * values[1] = { (void *)kCFNull };
+       CFDictionaryRef params = ::CFDictionaryCreate(NULL, keys, values, 1, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
+       if ( params == NULL ) {
+               CFRelease(code);
+               return false;
+       }
+       
+       SecCodeSignerRef signer;
+       status = ::SecCodeSignerCreate(params, kSecCSDefaultFlags, &signer);
+       CFRelease(params);
+       if ( status ) {
+               CFRelease(code);
+               ::fprintf(stderr, "codesign: failed to create signer object\n");
+               return false;
+       }
+
+       status = ::SecCodeSignerAddSignatureWithErrors(signer, code, kSecCSDefaultFlags, NULL);
+       CFRelease(code);
+       CFRelease(signer);
+       if ( status ) {
+               ::fprintf(stderr, "codesign: failed to sign object: %s\n", path);
+               return false;
+       }
+
+       if ( verbose )
+               ::fprintf(stderr, "codesigning complete of %s\n", path);
+       
+       return true;
+}
+
+
 
 template <>     bool   SharedCache<x86_64>::addCacheSlideInfo(){ return true; }
 template <>     bool   SharedCache<arm>::addCacheSlideInfo()   { return true; }
@@ -2324,7 +2407,7 @@ template <>        bool   SharedCache<x86>::addCacheSlideInfo()   { return false; }
 
 template <typename A>
 bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst, int archIndex,
-                                                               int archCount, bool keepSignatures)
+                                                               int archCount, bool keepSignatures, bool dontMapLocalSymbols)
 {
        bool didUpdate = false;
        
@@ -2374,6 +2457,8 @@ bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst,
                        header->set_codeSignatureSize(0);
                        header->set_slideInfoOffset(0);
                        header->set_slideInfoSize(0);
+                       header->set_localSymbolsOffset(0);
+                       header->set_localSymbolsSize(0);
                        
                        // fill in mappings
                        dyldCacheFileMapping<E>* mapping = (dyldCacheFileMapping<E>*)&inMemoryCache[sizeof(dyldCacheHeader<E>)];
@@ -2479,10 +2564,6 @@ bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst,
                        std::vector<void*> pointersInData;
                        pointersInData.reserve(1024);
                        
-                       // add pointer in start of __DATA to start of __TEXT to remain compatible with previous dylds
-                       pint_t* dataStartPtr = (pint_t*)(&inMemoryCache[fMappings[1].sfm_file_offset]);
-                       P::setP(*dataStartPtr, fMappings[0].sfm_address);
-
                        // rebase each dylib in shared cache
                        for(typename std::vector<LayoutInfo>::const_iterator it = fDylibs.begin(); it != fDylibs.end(); ++it) {
                                try {
@@ -2542,7 +2623,7 @@ bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst,
                        // merge/optimize all LINKEDIT segments
                        if ( optimize ) {
                                //fprintf(stderr, "update_dyld_shared_cache: original cache file size %uMB\n", cacheFileSize/(1024*1024));
-                               cacheFileSize = (this->optimizeLINKEDIT(keepSignatures) - inMemoryCache);
+                               cacheFileSize = (this->optimizeLINKEDIT(keepSignatures, dontMapLocalSymbols) - inMemoryCache);
                                //fprintf(stderr, "update_dyld_shared_cache: optimized cache file size %uMB\n", cacheFileSize/(1024*1024));
                                // update header to reduce mapping size
                                dyldCacheHeader<E>* cacheHeader = (dyldCacheHeader<E>*)inMemoryCache;
@@ -2623,7 +2704,7 @@ bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst,
                                }
                                slideInfo->set_entries_count(entry_count);
        
-                               int slideInfoPageSize = (slideInfo->entries_offset() + entry_count*entry_size + 4095) & (-4096);
+                               int slideInfoPageSize = pageAlign(slideInfo->entries_offset() + entry_count*entry_size);
                                cacheFileSize += slideInfoPageSize;
                        
                                // update mappings to increase RO size
@@ -2644,6 +2725,70 @@ bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst,
                                memcpy(&inMemoryCache[cacheHeader->slideInfoOffset()], slideInfo, slideInfoPageSize);   
                        }
                        
+                       // make sure after all optimizations, that whole cache file fits into shared region address range
+                       {
+                               dyldCacheHeader<E>* cacheHeader = (dyldCacheHeader<E>*)inMemoryCache;
+                               dyldCacheFileMapping<E>* mappings = (dyldCacheFileMapping<E>*)&inMemoryCache[cacheHeader->mappingOffset()];
+                               for (int i=0; i < cacheHeader->mappingCount(); ++i) {
+                                       uint64_t endAddr = mappings[i].address() + mappings[i].size();
+                                       if ( endAddr > (sharedRegionStartAddress() + sharedRegionSize()) ) {
+                                               throwf("update_dyld_shared_cache[%u] for arch=%s, shared cache will not fit in address space: 0x%llX\n",
+                                                       getpid(), fArchGraph->archName(), endAddr);
+                                       }
+                               }
+                       }
+                       
+                       // append local symbol info in an unmapped region
+                       if ( dontMapLocalSymbols ) {
+                               uint32_t spaceAtEnd = allocatedCacheSize - cacheFileSize;
+                               uint32_t localSymbolsOffset = pageAlign(cacheFileSize);
+                               dyldCacheLocalSymbolsInfo<E>* infoHeader = (dyldCacheLocalSymbolsInfo<E>*)(&inMemoryCache[localSymbolsOffset]);
+                               const uint32_t entriesOffset = sizeof(dyldCacheLocalSymbolsInfo<E>);
+                               const uint32_t entriesCount = fLocalSymbolInfos.size();
+                               const uint32_t nlistOffset = entriesOffset + entriesCount * sizeof(dyldCacheLocalSymbolEntry<E>);
+                               const uint32_t nlistCount = fUnmappedLocalSymbols.size();
+                               const uint32_t stringsOffset = nlistOffset + nlistCount * sizeof(macho_nlist<P>);
+                               const uint32_t stringsSize = fUnmappedLocalsStringPool.size();
+                               if ( stringsOffset+stringsSize > spaceAtEnd ) 
+                                       throwf("update_dyld_shared_cache[%u] for arch=%s, out of space for local symbols. Have 0x%X, Need 0x%X\n",
+                                                       getpid(), fArchGraph->archName(), spaceAtEnd, stringsOffset+stringsSize);
+                               // fill in local symbols info
+                               infoHeader->set_nlistOffset(nlistOffset);
+                               infoHeader->set_nlistCount(nlistCount);
+                               infoHeader->set_stringsOffset(stringsOffset);
+                               infoHeader->set_stringsSize(stringsSize);
+                               infoHeader->set_entriesOffset(entriesOffset);
+                               infoHeader->set_entriesCount(entriesCount);
+                               // copy info for each dylib
+                               dyldCacheLocalSymbolEntry<E>* entries = (dyldCacheLocalSymbolEntry<E>*)(&inMemoryCache[localSymbolsOffset+entriesOffset]);
+                               for (int i=0; i < entriesCount; ++i) {
+                                       entries[i].set_dylibOffset(fLocalSymbolInfos[i].dylibOffset);
+                                       entries[i].set_nlistStartIndex(fLocalSymbolInfos[i].nlistStartIndex);
+                                       entries[i].set_nlistCount(fLocalSymbolInfos[i].nlistCount);
+                               }
+                               // copy nlists
+                               memcpy(&inMemoryCache[localSymbolsOffset+nlistOffset], &fUnmappedLocalSymbols[0], nlistCount*sizeof(macho_nlist<P>));
+                               // copy string pool
+                               memcpy(&inMemoryCache[localSymbolsOffset+stringsOffset], fUnmappedLocalsStringPool.getBuffer(), stringsSize);
+                               
+                               // update state
+                               fUnmappedLocalSymbolsSize = pageAlign(stringsOffset + stringsSize);
+                               cacheFileSize = localSymbolsOffset + fUnmappedLocalSymbolsSize;
+                               
+                               // update header to show location of slidePointers
+                               dyldCacheHeader<E>* cacheHeader = (dyldCacheHeader<E>*)inMemoryCache;
+                               cacheHeader->set_localSymbolsOffset(localSymbolsOffset);
+                               cacheHeader->set_localSymbolsSize(stringsOffset+stringsSize);
+                               cacheHeader->set_codeSignatureOffset(cacheFileSize);
+                       }
+                       
+                       // compute UUID of whole cache
+                       uint8_t digest[16];
+                       CC_MD5(inMemoryCache, cacheFileSize, digest);
+                       // <rdar://problem/6723729> uuids should conform to RFC 4122 UUID version 4 & UUID version 5 formats
+                       digest[6] = ( digest[6] & 0x0F ) | ( 3 << 4 );
+                       digest[8] = ( digest[8] & 0x3F ) | 0x80;
+                       ((dyldCacheHeader<E>*)inMemoryCache)->set_uuid(digest);
                        
                        if ( fVerify ) {
                                // if no existing cache, say so
@@ -2758,6 +2903,9 @@ bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst,
                                if ( result != 0 ) 
                                        fprintf(stderr, "update_dyld_shared_cache: warning, close() failed with errno=%d for %s\n", errno, tempCachePath);
                                
+                               if ( !iPhoneOS )
+                                       adhoc_codesign_share_cache(tempCachePath);
+
                                // <rdar://problem/7901042> Make life easier for the kernel at shutdown.
                                // If we just move the new cache file over the old, the old file
                                // may need to exist in the open-unlink state.  But because it
@@ -2788,7 +2936,7 @@ bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst,
                                
                                
                                // flush everything to disk to assure rename() gets recorded
-                               ::sync();
+                               sync_volume(fCacheFilePath);
                                didUpdate = true;
                                
                                // restore default signal handlers
@@ -2817,57 +2965,71 @@ bool SharedCache<A>::update(bool force, bool optimize, bool deleteExistingFirst,
                                                else if ( it->sfm_init_prot == (VM_PROT_EXECUTE|VM_PROT_WRITE|VM_PROT_READ) )
                                                        prot = "WX";
                                                if ( it->sfm_size > 1024*1024 )
-                                                       fprintf(fmap, "mapping %s %4lluMB 0x%0llX -> 0x%0llX\n", prot, it->sfm_size/(1024*1024),
+                                                       fprintf(fmap, "mapping  %s %4lluMB 0x%0llX -> 0x%0llX\n", prot, it->sfm_size/(1024*1024),
                                                                                                                                it->sfm_address, it->sfm_address+it->sfm_size);
                                                else
-                                                       fprintf(fmap, "mapping %s %4lluKB 0x%0llX -> 0x%0llX\n", prot, it->sfm_size/1024,
+                                                       fprintf(fmap, "mapping  %s %4lluKB 0x%0llX -> 0x%0llX\n", prot, it->sfm_size/1024,
                                                                                                                                it->sfm_address, it->sfm_address+it->sfm_size);
                                        }
 
-                                       fprintf(fmap, "linkedit   %4uKB 0x%0llX -> 0x%0llX weak binding info\n",                
+                                       fprintf(fmap, " linkedit   %4uKB 0x%0llX -> 0x%0llX weak binding info\n",               
                                                                (fOffsetOfExportInfoInCombinedLinkedit-fOffsetOfWeakBindInfoInCombinedLinkedit)/1024,
                                                                fLinkEditsStartAddress+fOffsetOfWeakBindInfoInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfExportInfoInCombinedLinkedit);
-                                       fprintf(fmap, "linkedit   %4uKB 0x%0llX -> 0x%0llX export info\n",              
+                                       fprintf(fmap, " linkedit   %4uKB 0x%0llX -> 0x%0llX export info\n",             
                                                                (fOffsetOfBindInfoInCombinedLinkedit-fOffsetOfExportInfoInCombinedLinkedit)/1024,
                                                                fLinkEditsStartAddress+fOffsetOfExportInfoInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfBindInfoInCombinedLinkedit);
-                                       fprintf(fmap, "linkedit   %4uKB 0x%0llX -> 0x%0llX binding info\n",             
+                                       fprintf(fmap, " linkedit   %4uKB 0x%0llX -> 0x%0llX binding info\n",            
                                                                (fOffsetOfLazyBindInfoInCombinedLinkedit-fOffsetOfBindInfoInCombinedLinkedit)/1024,
                                                                fLinkEditsStartAddress+fOffsetOfBindInfoInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfLazyBindInfoInCombinedLinkedit);
-                                       fprintf(fmap, "linkedit   %4uKB 0x%0llX -> 0x%0llX lazy binding info\n",                
+                                       fprintf(fmap, " linkedit   %4uKB 0x%0llX -> 0x%0llX lazy binding info\n",               
                                                                (fOffsetOfOldSymbolTableInfoInCombinedLinkedit-fOffsetOfLazyBindInfoInCombinedLinkedit)/1024,
                                                                fLinkEditsStartAddress+fOffsetOfLazyBindInfoInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfOldSymbolTableInfoInCombinedLinkedit);
-                                       fprintf(fmap, "linkedit   %4uMB 0x%0llX -> 0x%0llX non-dyld symbol table size\n",               
+                                       fprintf(fmap, " linkedit   %4uMB 0x%0llX -> 0x%0llX non-dyld symbol table size\n",              
                                                                (fSizeOfOldSymbolTableInfoInCombinedLinkedit)/(1024*1024),
                                                                fLinkEditsStartAddress+fOffsetOfOldSymbolTableInfoInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfOldSymbolTableInfoInCombinedLinkedit+fSizeOfOldSymbolTableInfoInCombinedLinkedit);                              
                                        if ( fSizeOfFunctionStartsInCombinedLinkedit != 0 )
-                                               fprintf(fmap, "linkedit   %4uKB 0x%0llX -> 0x%0llX non-dyld functions starts size\n",           
+                                               fprintf(fmap, " linkedit   %4uKB 0x%0llX -> 0x%0llX non-dyld functions starts size\n",          
                                                                fSizeOfFunctionStartsInCombinedLinkedit/1024,
                                                                fLinkEditsStartAddress+fOffsetOfFunctionStartsInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfFunctionStartsInCombinedLinkedit+fSizeOfFunctionStartsInCombinedLinkedit);                              
                                        if ( fSizeOfDataInCodeInCombinedLinkedit != 0 )
-                                               fprintf(fmap, "linkedit   %4uKB 0x%0llX -> 0x%0llX non-dyld data-in-code info size\n",          
+                                               fprintf(fmap, " linkedit   %4uKB 0x%0llX -> 0x%0llX non-dyld data-in-code info size\n",         
                                                                fSizeOfDataInCodeInCombinedLinkedit/1024,
                                                                fLinkEditsStartAddress+fOffsetOfDataInCodeInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfDataInCodeInCombinedLinkedit+fSizeOfDataInCodeInCombinedLinkedit);                              
                                        if ( fSizeOfOldExternalRelocationsInCombinedLinkedit != 0 )
-                                               fprintf(fmap, "linkedit   %4uKB 0x%0llX -> 0x%0llX non-dyld external relocs size\n",            
+                                               fprintf(fmap, " linkedit   %4uKB 0x%0llX -> 0x%0llX non-dyld external relocs size\n",           
                                                                fSizeOfOldExternalRelocationsInCombinedLinkedit/1024,
                                                                fLinkEditsStartAddress+fOffsetOfOldExternalRelocationsInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfOldExternalRelocationsInCombinedLinkedit+fSizeOfOldExternalRelocationsInCombinedLinkedit);                              
-                                       fprintf(fmap, "linkedit   %4uKB 0x%0llX -> 0x%0llX non-dyld indirect symbol table size\n",              
+                                       fprintf(fmap, " linkedit   %4uKB 0x%0llX -> 0x%0llX non-dyld indirect symbol table size\n",             
                                                                fSizeOfOldIndirectSymbolsInCombinedLinkedit/1024,
                                                                fLinkEditsStartAddress+fOffsetOfOldIndirectSymbolsInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfOldIndirectSymbolsInCombinedLinkedit+fSizeOfOldIndirectSymbolsInCombinedLinkedit);                              
-                                       fprintf(fmap, "linkedit   %4uMB 0x%0llX -> 0x%0llX non-dyld string pool\n",             
+                                       fprintf(fmap, " linkedit   %4uMB 0x%0llX -> 0x%0llX non-dyld string pool\n",            
                                                                (fSizeOfOldStringPoolInCombinedLinkedit)/(1024*1024),
                                                                fLinkEditsStartAddress+fOffsetOfOldStringPoolInCombinedLinkedit,
                                                                fLinkEditsStartAddress+fOffsetOfOldStringPoolInCombinedLinkedit+fSizeOfOldStringPoolInCombinedLinkedit);                                
                                        
+                                       fprintf(fmap, "unmapped -- %4uMB local symbol info\n", fUnmappedLocalSymbolsSize/(1024*1024));                                  
+                                       
+                                       uint64_t endMappingAddr = fMappings[2].sfm_address + fMappings[2].sfm_size;
+                                       fprintf(fmap, "total map   %4lluMB\n", (endMappingAddr - sharedRegionStartAddress())/(1024*1024));      
+                                       if ( sharedRegionStartWritableAddress(0) == 0x7FFF70000000LL ) {
+                                               // x86_64 has different slide constraints
+                                               uint64_t freeSpace = 256*1024*1024 - fMappings[1].sfm_size;
+                                               fprintf(fmap, "r/w space   %4lluMB -> %d bits of entropy for ASLR\n\n", freeSpace/(1024*1024), (int)log2(freeSpace/4096));
+                                       }
+                                       else {
+                                               uint64_t freeSpace = sharedRegionStartAddress() + sharedRegionSize() - endMappingAddr;
+                                               fprintf(fmap, "free space  %4lluMB -> %d bits of entropy for ASLR\n\n", freeSpace/(1024*1024), (int)log2(freeSpace/4096));
+                                       }
+                                       
                                        for(typename std::vector<LayoutInfo>::const_iterator it = fDylibs.begin(); it != fDylibs.end(); ++it) {
                                                fprintf(fmap, "%s\n", it->layout->getID().name);
                                                for (std::vector<const char*>::const_iterator ait = it->aliases.begin(); ait != it->aliases.end(); ++ait) 
@@ -2967,8 +3129,9 @@ static void parsePathsFile(const char* filePath, std::vector<const char*>& paths
                                        // <rdar://problem/8305479> images in shared cache are bound against different IOKit than found at runtime
                                        // HACK:  Just ignore the known bad IOKit
                                        if ( strcmp(symbolStart, "/System/Library/Frameworks/IOKit.framework/IOKit") == 0 ) {
-                                               fprintf(stderr, "update_dyld_shared_cache: warning, ignoring /System/Library/Frameworks/IOKit.framework/IOKit\n");
-                                               warnings.push_back("update_dyld_shared_cache: warning, ignoring /System/Library/Frameworks/IOKit.framework/IOKit\n");
+                                               // Disable warning because after three years <rdar://problem/7089957> has still not been fixed...
+                                               //fprintf(stderr, "update_dyld_shared_cache: warning, ignoring /System/Library/Frameworks/IOKit.framework/IOKit\n");
+                                               //warnings.push_back("update_dyld_shared_cache: warning, ignoring /System/Library/Frameworks/IOKit.framework/IOKit\n");
                                        }
                                        else {
                                                paths.push_back(symbolStart);
@@ -3108,7 +3271,7 @@ static void deleteOrphanTempCacheFiles()
 
 
 static bool updateSharedeCacheFile(const char* rootPath, const char* overlayPath, const char* cacheDir, bool explicitCacheDir, const std::set<ArchPair>& onlyArchs, 
-                                                                       bool force, bool alphaSort, bool optimize, bool deleteExistingFirst, bool verify, bool keepSignatures)
+                                                                       bool force, bool alphaSort, bool optimize, bool deleteExistingFirst, bool verify, bool keepSignatures, bool dontMapLocalSymbols)
 {
        bool didUpdate = false;
        // get dyld load address info
@@ -3136,19 +3299,19 @@ static bool updateSharedeCacheFile(const char* rootPath, const char* overlayPath
                        case CPU_TYPE_I386:
                                {
                                        SharedCache<x86> cache(ArchGraph::graphForArchPair(*a), rootPath, overlayPath, cacheDir, explicitCacheDir, alphaSort, verify, optimize, dyldBaseAddress);
-                                       didUpdate |= cache.update(force, optimize, deleteExistingFirst, index, archCount, keepSignatures);
+                                       didUpdate |= cache.update(force, optimize, deleteExistingFirst, index, archCount, keepSignatures, dontMapLocalSymbols);
                                }
                                break;
                        case CPU_TYPE_X86_64:
                                {
                                        SharedCache<x86_64> cache(ArchGraph::graphForArchPair(*a), rootPath, overlayPath, cacheDir, explicitCacheDir, alphaSort, verify, optimize, dyldBaseAddress);
-                                       didUpdate |= cache.update(force, optimize, deleteExistingFirst, index, archCount, keepSignatures);
+                                       didUpdate |= cache.update(force, optimize, deleteExistingFirst, index, archCount, keepSignatures, dontMapLocalSymbols);
                                }
                                break;
                        case CPU_TYPE_ARM:
                                {
                                        SharedCache<arm> cache(ArchGraph::graphForArchPair(*a), rootPath, overlayPath, cacheDir, explicitCacheDir, alphaSort, verify, optimize, dyldBaseAddress);
-                                       didUpdate |= cache.update(force, optimize, deleteExistingFirst, index, archCount, keepSignatures);
+                                       didUpdate |= cache.update(force, optimize, deleteExistingFirst, index, archCount, keepSignatures, dontMapLocalSymbols);
                                }
                                break;
                }
@@ -3179,6 +3342,7 @@ int main(int argc, const char* argv[])
        bool verify = false;
        bool keepSignatures = false;
        bool explicitCacheDir = false;
+       bool dontMapLocalSymbols = false;
        const char* cacheDir = NULL;
        
        try {
@@ -3207,8 +3371,12 @@ int main(int argc, const char* argv[])
                                else if ( strcmp(arg, "-no_opt") == 0 ) {
                                        optimize = false;
                                }
+                               else if ( strcmp(arg, "-dont_map_local_symbols") == 0 ) {
+                                       dontMapLocalSymbols = true;
+                               }
                                else if ( strcmp(arg, "-iPhone") == 0 ) {
                                        iPhoneOS = true;
+                                       alphaSort = true;
                                }
                                else if ( strcmp(arg, "-dylib_list") == 0 ) {
                                        dylibListFile = argv[++i];
@@ -3249,6 +3417,8 @@ int main(int argc, const char* argv[])
                                                onlyArchs.insert(ArchPair(CPU_TYPE_ARM, CPU_SUBTYPE_ARM_V7F));
                                        else if ( strcmp(arch, "armv7k") == 0 )
                                                onlyArchs.insert(ArchPair(CPU_TYPE_ARM, CPU_SUBTYPE_ARM_V7K));
+                                       else if ( strcmp(arch, "armv7s") == 0 )
+                                               onlyArchs.insert(ArchPair(CPU_TYPE_ARM, CPU_SUBTYPE_ARM_V7S));
                                        else 
                                                throwf("unknown architecture %s", arch);
                                }
@@ -3316,8 +3486,23 @@ int main(int argc, const char* argv[])
                        setSharedDylibs(rootPath, overlayPath, dylibListFile, onlyArchs);
                else
                        scanForSharedDylibs(rootPath, overlayPath, "/var/db/dyld/shared_region_roots/", onlyArchs);
-               updateSharedeCacheFile(rootPath, overlayPath, cacheDir, explicitCacheDir, onlyArchs, force, alphaSort, optimize, 
-                                                               false, verify, keepSignatures);
+               bool didUpdate = updateSharedeCacheFile(rootPath, overlayPath, cacheDir, explicitCacheDir, onlyArchs, force, alphaSort, optimize,
+                                                               false, verify, keepSignatures, dontMapLocalSymbols);
+                                                               
+               if ( didUpdate && !iPhoneOS ) {
+                       void* handle = dlopen("/usr/lib/libspindump.dylib", RTLD_LAZY);
+                       if ( handle != NULL ) {
+                               typedef bool (*dscsym_proc_t)(const char *root);
+                               dscsym_proc_t proc = (dscsym_proc_t)dlsym(handle, "dscsym_save_nuggets_for_current_caches");
+                               const char* nuggetRootPath = "/";
+                               if ( overlayPath[0] != '\0' ) 
+                                       nuggetRootPath = overlayPath;
+                               else if ( rootPath[0] != '\0' )
+                                       nuggetRootPath = rootPath;
+                               (*proc)(nuggetRootPath);
+                       }
+                       dlclose(handle);
+               }
        }
        catch (const char* msg) {
                fprintf(stderr, "update_dyld_shared_cache failed: %s\n", msg);