dyld3/shared-cache/update_dyld_shared_cache.cpp

   1 /* -*- mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
   2  *
   3  * Copyright (c) 2014 Apple Inc. All rights reserved.
   4  *
   5  * @APPLE_LICENSE_HEADER_START@
   6  *
   7  * This file contains Original Code and/or Modifications of Original Code
   8  * as defined in and that are subject to the Apple Public Source License
   9  * Version 2.0 (the 'License'). You may not use this file except in
  10  * compliance with the License. Please obtain a copy of the License at
  11  * http://www.opensource.apple.com/apsl/ and read it before using this
  12  * file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  19  * Please see the License for the specific language governing rights and
  20  * limitations under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24
  25 #include <sys/types.h>
  26 #include <sys/stat.h>
  27 #include <sys/mman.h>
  28 #include <mach/mach.h>
  29 #include <mach/mach_time.h>
  30 #include <limits.h>
  31 #include <stdarg.h>
  32 #include <stdio.h>
  33 #include <stdlib.h>
  34 #include <math.h>
  35 #include <fcntl.h>
  36 #include <dlfcn.h>
  37 #include <signal.h>
  38 #include <errno.h>
  39 #include <assert.h>
  40 #include <sys/uio.h>
  41 #include <unistd.h>
  42 #include <sys/param.h>
  43 #include <sys/sysctl.h>
  44 #include <sys/resource.h>
  45 #include <dirent.h>
  46 #include <rootless.h>
  47 #include <dscsym.h>
  48 #include <dispatch/dispatch.h>
  49 #include <pthread/pthread.h>
  50 #include <Bom/Bom.h>
  51 #include <CoreFoundation/CoreFoundation.h>
  52
  53 #include <algorithm>
  54 #include <vector>
  55 #include <unordered_set>
  56 #include <unordered_set>
  57 #include <iostream>
  58 #include <fstream>
  59
  60 #include "MachOParser.h"
  61 #include "FileUtils.h"
  62 #include "StringUtils.h"
  63 #include "DyldSharedCache.h"
  64
  65 struct MappedMachOsByCategory
  66 {
  67     std::string                                 archName;
  68     std::vector<DyldSharedCache::MappedMachO>   dylibsForCache;
  69     std::vector<DyldSharedCache::MappedMachO>   otherDylibsAndBundles;
  70     std::vector<DyldSharedCache::MappedMachO>   mainExecutables;
  71 };
  72
  73 static const char* sAllowedPrefixes[] = {
  74     "/bin/",
  75     "/sbin/",
  76     "/usr/",
  77     "/System",
  78     "/Applications/App Store.app/",
  79     "/Applications/Automator.app/",
  80     "/Applications/Calculator.app/",
  81     "/Applications/Calendar.app/",
  82     "/Applications/Chess.app/",
  83     "/Applications/Contacts.app/",
  84 //    "/Applications/DVD Player.app/",
  85     "/Applications/Dashboard.app/",
  86     "/Applications/Dictionary.app/",
  87     "/Applications/FaceTime.app/",
  88     "/Applications/Font Book.app/",
  89     "/Applications/Image Capture.app/",
  90     "/Applications/Launchpad.app/",
  91     "/Applications/Mail.app/",
  92     "/Applications/Maps.app/",
  93     "/Applications/Messages.app/",
  94     "/Applications/Mission Control.app/",
  95     "/Applications/Notes.app/",
  96     "/Applications/Photo Booth.app/",
  97 //    "/Applications/Photos.app/",
  98     "/Applications/Preview.app/",
  99     "/Applications/QuickTime Player.app/",
 100     "/Applications/Reminders.app/",
 101     "/Applications/Safari.app/",
 102     "/Applications/Siri.app/",
 103     "/Applications/Stickies.app/",
 104     "/Applications/System Preferences.app/",
 105     "/Applications/TextEdit.app/",
 106     "/Applications/Time Machine.app/",
 107     "/Applications/iBooks.app/",
 108     "/Applications/iTunes.app/",
 109     "/Applications/Utilities/Activity Monitor.app",
 110     "/Applications/Utilities/AirPort Utility.app",
 111     "/Applications/Utilities/Audio MIDI Setup.app",
 112     "/Applications/Utilities/Bluetooth File Exchange.app",
 113     "/Applications/Utilities/Boot Camp Assistant.app",
 114     "/Applications/Utilities/ColorSync Utility.app",
 115     "/Applications/Utilities/Console.app",
 116     "/Applications/Utilities/Digital Color Meter.app",
 117     "/Applications/Utilities/Disk Utility.app",
 118     "/Applications/Utilities/Grab.app",
 119     "/Applications/Utilities/Grapher.app",
 120     "/Applications/Utilities/Keychain Access.app",
 121     "/Applications/Utilities/Migration Assistant.app",
 122     "/Applications/Utilities/Script Editor.app",
 123     "/Applications/Utilities/System Information.app",
 124     "/Applications/Utilities/Terminal.app",
 125     "/Applications/Utilities/VoiceOver Utility.app",
 126     "/Library/CoreMediaIO/Plug-Ins/DAL/"                // temp until plugins moved or closured working
 127 };
 128
 129 static const char* sDontUsePrefixes[] = {
 130     "/usr/share",
 131     "/usr/local/",
 132     "/System/Library/Assets",
 133     "/System/Library/StagedFrameworks",
 134     "/System/Library/Kernels/",
 135     "/bin/zsh",                             // until <rdar://31026756> is fixed
 136     "/System/Library/Frameworks/CoreServices.framework/Versions/A/Frameworks/Metadata.framework/Versions/A/Support/mdworker", // these load third party plugins
 137     "/usr/bin/mdimport", // these load third party plugins
 138 };
 139
 140
 141 static bool verbose = false;
 142
 143
 144
 145 static bool addIfMachO(const std::string& pathPrefix, const std::string& runtimePath, const struct stat& statBuf, bool requireSIP, std::vector<MappedMachOsByCategory>& files)
 146 {
 147     // don't precompute closure info for any debug or profile dylibs
 148     if ( endsWith(runtimePath, "_profile.dylib") || endsWith(runtimePath, "_debug.dylib") || endsWith(runtimePath, "_profile") || endsWith(runtimePath, "_debug") )
 149         return false;
 150
 151     // read start of file to determine if it is mach-o or a fat file
 152     std::string fullPath = pathPrefix + runtimePath;
 153     int fd = ::open(fullPath.c_str(), O_RDONLY);
 154     if ( fd < 0 )
 155         return false;
 156     bool result = false;
 157     const void* wholeFile = ::mmap(NULL, statBuf.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
 158     if ( wholeFile != MAP_FAILED ) {
 159         Diagnostics diag;
 160         bool usedWholeFile = false;
 161         for (MappedMachOsByCategory& file : files) {
 162             size_t sliceOffset;
 163             size_t sliceLength;
 164             bool fatButMissingSlice;
 165             const void* slice = MAP_FAILED;
 166             if ( dyld3::FatUtil::isFatFileWithSlice(diag, wholeFile, statBuf.st_size, file.archName, sliceOffset, sliceLength, fatButMissingSlice) ) {
 167                 slice = ::mmap(NULL, sliceLength, PROT_READ, MAP_PRIVATE | MAP_RESILIENT_CODESIGN, fd, sliceOffset);
 168                 if ( slice != MAP_FAILED ) {
 169                     //fprintf(stderr, "mapped slice at %p size=0x%0lX, offset=0x%0lX for %s\n", p, len, offset, fullPath.c_str());
 170                     if ( !dyld3::MachOParser::isValidMachO(diag, file.archName, dyld3::Platform::macOS, slice, sliceLength, fullPath.c_str(), false) ) {
 171                         ::munmap((void*)slice, sliceLength);
 172                         slice = MAP_FAILED;
 173                     }
 174                 }
 175             }
 176             else if ( !fatButMissingSlice && dyld3::MachOParser::isValidMachO(diag, file.archName, dyld3::Platform::macOS, wholeFile, statBuf.st_size, fullPath.c_str(), false) ) {
 177                 slice           = wholeFile;
 178                 sliceLength     = statBuf.st_size;
 179                 sliceOffset     = 0;
 180                 usedWholeFile   = true;
 181                 //fprintf(stderr, "mapped whole file at %p size=0x%0lX for %s\n", p, len, inputPath.c_str());
 182             }
 183             std::vector<std::string> nonArchWarnings;
 184             for (const std::string& warning : diag.warnings()) {
 185                 if ( !contains(warning, "required architecture") && !contains(warning, "not a dylib") )
 186                     nonArchWarnings.push_back(warning);
 187             }
 188             diag.clearWarnings();
 189             if ( !nonArchWarnings.empty() ) {
 190                 fprintf(stderr, "update_dyld_shared_cache: warning: %s for %s: ", file.archName.c_str(), runtimePath.c_str());
 191                 for (const std::string& warning : nonArchWarnings) {
 192                     fprintf(stderr, "%s ", warning.c_str());
 193                 }
 194                 fprintf(stderr, "\n");
 195             }
 196             if ( slice != MAP_FAILED ) {
 197                 const mach_header* mh = (mach_header*)slice;
 198                 dyld3::MachOParser parser((mach_header*)slice);
 199                 bool sipProtected = isProtectedBySIP(fd);
 200                 bool issetuid = false;
 201                 if ( parser.isDynamicExecutable() ) {
 202                     // When SIP enabled, only build closures for SIP protected programs
 203                     if ( !requireSIP || sipProtected ) {
 204                         //fprintf(stderr, "requireSIP=%d, sipProtected=%d, path=%s\n", requireSIP, sipProtected, fullPath.c_str());
 205                         issetuid = (statBuf.st_mode & (S_ISUID|S_ISGID));
 206                         file.mainExecutables.emplace_back(runtimePath, mh, sliceLength, issetuid, sipProtected, sliceOffset, statBuf.st_mtime, statBuf.st_ino);
 207                     }
 208                 }
 209                 else if ( parser.canBePlacedInDyldCache(runtimePath) ) {
 210                     // when SIP is enabled, only dylib protected by SIP can go in cache
 211                     if ( !requireSIP || sipProtected )
 212                         file.dylibsForCache.emplace_back(runtimePath, mh, sliceLength, issetuid, sipProtected, sliceOffset, statBuf.st_mtime, statBuf.st_ino);
 213                     else
 214                         file.otherDylibsAndBundles.emplace_back(runtimePath, mh, sliceLength, issetuid, sipProtected, sliceOffset, statBuf.st_mtime, statBuf.st_ino);
 215                 }
 216                 else {
 217                     if ( parser.fileType() == MH_DYLIB ) {
 218                         std::string installName = parser.installName();
 219                         if ( startsWith(installName, "@") && !contains(runtimePath, ".app/") ) {
 220                             if (  startsWith(runtimePath, "/usr/lib/") || startsWith(runtimePath, "/System/Library/") )
 221                                 fprintf(stderr, "update_dyld_shared_cache: warning @rpath install name for system framework: %s\n", runtimePath.c_str());
 222                         }
 223                     }
 224                     file.otherDylibsAndBundles.emplace_back(runtimePath, mh, sliceLength, issetuid, sipProtected, sliceOffset, statBuf.st_mtime, statBuf.st_ino);
 225                 }
 226                 result = true;
 227             }
 228         }
 229         if ( !usedWholeFile )
 230             ::munmap((void*)wholeFile, statBuf.st_size);
 231     }
 232     ::close(fd);
 233     return result;
 234 }
 235
 236 static void findAllFiles(const std::vector<std::string>& pathPrefixes, bool requireSIP, std::vector<MappedMachOsByCategory>& files)
 237 {
 238     std::unordered_set<std::string> skipDirs;
 239     for (const char* s : sDontUsePrefixes)
 240         skipDirs.insert(s);
 241
 242     __block std::unordered_set<std::string> alreadyUsed;
 243     bool multiplePrefixes = (pathPrefixes.size() > 1);
 244     for (const std::string& prefix : pathPrefixes) {
 245         // get all files from overlay for this search dir
 246         for (const char* searchDir : sAllowedPrefixes ) {
 247             iterateDirectoryTree(prefix, searchDir, ^(const std::string& dirPath) { return (skipDirs.count(dirPath) != 0); }, ^(const std::string& path, const struct stat& statBuf) {
 248                 // ignore files that don't have 'x' bit set (all runnable mach-o files do)
 249                 const bool hasXBit = ((statBuf.st_mode & S_IXOTH) == S_IXOTH);
 250                 if ( !hasXBit && !endsWith(path, ".dylib") )
 251                     return;
 252
 253                 // ignore files too small
 254                 if ( statBuf.st_size < 0x3000 )
 255                     return;
 256
 257                 // don't add paths already found using previous prefix
 258                 if ( multiplePrefixes && (alreadyUsed.count(path) != 0) )
 259                     return;
 260
 261                 // if the file is mach-o, add to list
 262                 if ( addIfMachO(prefix, path, statBuf, requireSIP, files) ) {
 263                     if ( multiplePrefixes )
 264                         alreadyUsed.insert(path);
 265                 }
 266             });
 267         }
 268     }
 269 }
 270
 271
 272 static void findOSFilesViaBOMS(const std::vector<std::string>& pathPrefixes, bool requireSIP, std::vector<MappedMachOsByCategory>& files)
 273 {
 274     __block std::unordered_set<std::string> runtimePathsFound;
 275     for (const std::string& prefix : pathPrefixes) {
 276         iterateDirectoryTree(prefix, "/System/Library/Receipts", ^(const std::string&) { return false; }, ^(const std::string& path, const struct stat& statBuf) {
 277             if ( !contains(path, "com.apple.pkg.") )
 278                 return;
 279             if ( !endsWith(path, ".bom") )
 280                 return;
 281             std::string fullPath = prefix + path;
 282             BOMBom bom = BOMBomOpenWithSys(fullPath.c_str(), false, NULL);
 283             if ( bom == nullptr )
 284                 return;
 285             BOMFSObject rootFso = BOMBomGetRootFSObject(bom);
 286             if ( rootFso == nullptr ) {
 287                 BOMBomFree(bom);
 288                 return;
 289             }
 290             BOMBomEnumerator e = BOMBomEnumeratorNew(bom, rootFso);
 291             if ( e == nullptr ) {
 292                 fprintf(stderr, "Can't get enumerator for BOM root FSObject\n");
 293                 return;
 294             }
 295             BOMFSObjectFree(rootFso);
 296             //fprintf(stderr, "using BOM %s\n", path.c_str());
 297             while (BOMFSObject fso = BOMBomEnumeratorNext(e)) {
 298                 if ( BOMFSObjectIsBinaryObject(fso) ) {
 299                     const char* runPath = BOMFSObjectPathName(fso);
 300                     if ( (runPath[0] == '.') && (runPath[1] == '/') )
 301                         ++runPath;
 302                     if ( runtimePathsFound.count(runPath) == 0 ) {
 303                         // only add files from sAllowedPrefixes and not in sDontUsePrefixes
 304                         bool inSearchDir = false;
 305                         for (const char* searchDir : sAllowedPrefixes ) {
 306                             if ( strncmp(searchDir, runPath, strlen(searchDir)) == 0 )  {
 307                                 inSearchDir = true;
 308                                 break;
 309                             }
 310                         }
 311                         if ( inSearchDir ) {
 312                             bool inSkipDir = false;
 313                             for (const char* skipDir : sDontUsePrefixes) {
 314                                 if ( strncmp(skipDir, runPath, strlen(skipDir)) == 0 )  {
 315                                     inSkipDir = true;
 316                                     break;
 317                                 }
 318                             }
 319                             if ( !inSkipDir ) {
 320                                 for (const std::string& prefix2 : pathPrefixes) {
 321                                     struct stat statBuf2;
 322                                     std::string fullPath2 = prefix2 + runPath;
 323                                     if ( stat(fullPath2.c_str(), &statBuf2) == 0 ) {
 324                                         addIfMachO(prefix2, runPath, statBuf2, requireSIP, files);
 325                                         runtimePathsFound.insert(runPath);
 326                                         break;
 327                                     }
 328                                 }
 329                             }
 330                         }
 331                     }
 332                 }
 333                 BOMFSObjectFree(fso);
 334             }
 335
 336             BOMBomEnumeratorFree(e);
 337             BOMBomFree(bom);
 338         });
 339     }
 340 }
 341
 342
 343 static bool dontCache(const std::string& volumePrefix, const std::string& archName,
 344                       const std::unordered_set<std::string>& pathsWithDuplicateInstallName,
 345                       const DyldSharedCache::MappedMachO& aFile, bool warn,
 346                       const std::unordered_set<std::string>& skipDylibs)
 347 {
 348     if ( skipDylibs.count(aFile.runtimePath) )
 349         return true;
 350     if ( startsWith(aFile.runtimePath, "/usr/lib/system/introspection/") )
 351         return true;
 352     if ( startsWith(aFile.runtimePath, "/System/Library/QuickTime/") )
 353         return true;
 354     if ( startsWith(aFile.runtimePath, "/System/Library/Tcl/") )
 355         return true;
 356     if ( startsWith(aFile.runtimePath, "/System/Library/Perl/") )
 357         return true;
 358     if ( startsWith(aFile.runtimePath, "/System/Library/MonitorPanels/") )
 359         return true;
 360     if ( startsWith(aFile.runtimePath, "/System/Library/Accessibility/") )
 361         return true;
 362     if ( startsWith(aFile.runtimePath, "/usr/local/") )
 363         return true;
 364
 365     // anything inside a .app bundle is specific to app, so should not be in shared cache
 366     if ( aFile.runtimePath.find(".app/") != std::string::npos )
 367         return true;
 368
 369     if ( archName == "i386" ) {
 370         if ( startsWith(aFile.runtimePath, "/System/Library/CoreServices/") )
 371             return true;
 372         if ( startsWith(aFile.runtimePath, "/System/Library/Extensions/") )
 373             return true;
 374     }
 375
 376     if ( aFile.runtimePath.find("//") != std::string::npos ) {
 377         if (warn) fprintf(stderr, "update_dyld_shared_cache: warning: %s skipping because of bad install name %s\n", archName.c_str(), aFile.runtimePath.c_str());
 378         return true;
 379     }
 380
 381     dyld3::MachOParser parser(aFile.mh);
 382     const char* installName = parser.installName();
 383     if ( (pathsWithDuplicateInstallName.count(aFile.runtimePath) != 0) && (aFile.runtimePath != installName) ) {
 384         if (warn) fprintf(stderr, "update_dyld_shared_cache: warning: %s skipping because of duplicate install name %s\n", archName.c_str(), aFile.runtimePath.c_str());
 385         return true;
 386     }
 387
 388     if ( aFile.runtimePath != installName ) {
 389         // see if install name is a symlink to actual path
 390         std::string fullInstall = volumePrefix + installName;
 391         char resolvedPath[PATH_MAX];
 392         if ( realpath(fullInstall.c_str(), resolvedPath) != NULL ) {
 393             std::string resolvedSymlink = resolvedPath;
 394             if ( !volumePrefix.empty() ) {
 395                 resolvedSymlink = resolvedSymlink.substr(volumePrefix.size());
 396             }
 397             if ( aFile.runtimePath == resolvedSymlink ) {
 398                 return false;
 399             }
 400         }
 401         if (warn) fprintf(stderr, "update_dyld_shared_cache: warning: %s skipping because of bad install name %s\n", archName.c_str(), aFile.runtimePath.c_str());
 402         return true;
 403     }
 404     return false;
 405 }
 406
 407 static void pruneCachedDylibs(const std::string& volumePrefix, const std::unordered_set<std::string>& skipDylibs, MappedMachOsByCategory& fileSet)
 408 {
 409     std::unordered_set<std::string> pathsWithDuplicateInstallName;
 410
 411     std::unordered_map<std::string, std::string> installNameToFirstPath;
 412     for (DyldSharedCache::MappedMachO& aFile : fileSet.dylibsForCache) {
 413         dyld3::MachOParser parser(aFile.mh);
 414         const char* installName = parser.installName();
 415         auto pos = installNameToFirstPath.find(installName);
 416         if ( pos == installNameToFirstPath.end() ) {
 417             installNameToFirstPath[installName] = aFile.runtimePath;
 418         }
 419         else {
 420             pathsWithDuplicateInstallName.insert(aFile.runtimePath);
 421             pathsWithDuplicateInstallName.insert(installNameToFirstPath[installName]);
 422         }
 423     }
 424
 425     for (DyldSharedCache::MappedMachO& aFile : fileSet.dylibsForCache) {
 426         if ( dontCache(volumePrefix, fileSet.archName, pathsWithDuplicateInstallName, aFile, true, skipDylibs) )
 427             fileSet.otherDylibsAndBundles.push_back(aFile);
 428     }
 429     fileSet.dylibsForCache.erase(std::remove_if(fileSet.dylibsForCache.begin(), fileSet.dylibsForCache.end(),
 430         [&](const DyldSharedCache::MappedMachO& aFile) { return dontCache(volumePrefix, fileSet.archName, pathsWithDuplicateInstallName, aFile, false, skipDylibs); }),
 431         fileSet.dylibsForCache.end());
 432 }
 433
 434 static void pruneOtherDylibs(const std::string& volumePrefix, MappedMachOsByCategory& fileSet)
 435 {
 436     // other OS dylibs should not contain dylibs that are embedded in some .app bundle
 437     fileSet.otherDylibsAndBundles.erase(std::remove_if(fileSet.otherDylibsAndBundles.begin(), fileSet.otherDylibsAndBundles.end(),
 438         [&](const DyldSharedCache::MappedMachO& aFile) { return (aFile.runtimePath.find(".app/") != std::string::npos); }),
 439         fileSet.otherDylibsAndBundles.end());
 440 }
 441
 442
 443 static void pruneExecutables(const std::string& volumePrefix, MappedMachOsByCategory& fileSet)
 444 {
 445     // don't build closures for xcode shims in /usr/bin (e.g. /usr/bin/clang) which re-exec themselves to a tool inside Xcode.app
 446     fileSet.mainExecutables.erase(std::remove_if(fileSet.mainExecutables.begin(), fileSet.mainExecutables.end(),
 447         [&](const DyldSharedCache::MappedMachO& aFile) {
 448             if ( !startsWith(aFile.runtimePath, "/usr/bin/") )
 449                 return false;
 450             dyld3::MachOParser parser(aFile.mh);
 451             __block bool isXcodeShim = false;
 452             parser.forEachDependentDylib(^(const char* loadPath, bool, bool, bool, uint32_t, uint32_t, bool &stop) {
 453                 if ( strcmp(loadPath, "/usr/lib/libxcselect.dylib") == 0 )
 454                     isXcodeShim = true;
 455             });
 456             return isXcodeShim;
 457         }), fileSet.mainExecutables.end());
 458 }
 459
 460 static bool existingCacheUpToDate(const std::string& existingCache, const std::vector<DyldSharedCache::MappedMachO>& currentDylibs)
 461 {
 462     // if no existing cache, it is not up-to-date
 463     int fd = ::open(existingCache.c_str(), O_RDONLY);
 464     if ( fd < 0 )
 465         return false;
 466
 467     // build map of found dylibs
 468     std::unordered_map<std::string, const DyldSharedCache::MappedMachO*> currentDylibMap;
 469     for (const DyldSharedCache::MappedMachO& aFile : currentDylibs) {
 470         //fprintf(stderr, "0x%0llX 0x%0llX  %s\n", aFile.inode, aFile.modTime, aFile.runtimePath.c_str());
 471         currentDylibMap[aFile.runtimePath] = &aFile;
 472     }
 473
 474     // make sure all dylibs in existing cache have same mtime and inode as found dylib
 475     __block bool foundMismatch = false;
 476     const uint64_t cacheMapLen = 0x40000000;
 477     void *p = ::mmap(NULL, cacheMapLen, PROT_READ, MAP_PRIVATE, fd, 0);
 478     if ( p != MAP_FAILED ) {
 479         const DyldSharedCache* cache = (DyldSharedCache*)p;
 480         cache->forEachImageEntry(^(const char* installName, uint64_t mTime, uint64_t inode) {
 481             bool foundMatch = false;
 482             auto pos = currentDylibMap.find(installName);
 483             if ( pos != currentDylibMap.end() ) {
 484                 const DyldSharedCache::MappedMachO* foundDylib = pos->second;
 485                 if ( (foundDylib->inode == inode) && (foundDylib->modTime == mTime) ) {
 486                     foundMatch = true;
 487                 }
 488             }
 489             if ( !foundMatch ) {
 490                 // use slow path and look for any dylib with a matching inode and mtime
 491                 bool foundSlow = false;
 492                 for (const DyldSharedCache::MappedMachO& aFile : currentDylibs) {
 493                     if ( (aFile.inode == inode) && (aFile.modTime == mTime) ) {
 494                         foundSlow = true;
 495                         break;
 496                     }
 497                 }
 498                 if ( !foundSlow ) {
 499                     foundMismatch = true;
 500                     if ( verbose )
 501                         fprintf(stderr, "rebuilding dyld cache because dylib changed: %s\n", installName);
 502                 }
 503             }
 504          });
 505         ::munmap(p, cacheMapLen);
 506     }
 507
 508     ::close(fd);
 509
 510     return !foundMismatch;
 511 }
 512
 513
 514 inline uint32_t absolutetime_to_milliseconds(uint64_t abstime)
 515 {
 516     return (uint32_t)(abstime/1000/1000);
 517 }
 518
 519 static bool runningOnHaswell()
 520 {
 521     // check system is capable of running x86_64h code
 522     struct host_basic_info  info;
 523     mach_msg_type_number_t  count    = HOST_BASIC_INFO_COUNT;
 524     mach_port_t             hostPort = mach_host_self();
 525     kern_return_t           result   = host_info(hostPort, HOST_BASIC_INFO, (host_info_t)&info, &count);
 526     mach_port_deallocate(mach_task_self(), hostPort);
 527
 528     return ( (result == KERN_SUCCESS) && (info.cpu_subtype == CPU_SUBTYPE_X86_64_H) );
 529 }
 530
 531
 532
 533 #define TERMINATE_IF_LAST_ARG( s )      \
 534     do {                                \
 535         if ( i == argc - 1 ) {          \
 536             fprintf(stderr, s );        \
 537             return 1;                   \
 538         }                               \
 539     } while ( 0 )
 540
 541 int main(int argc, const char* argv[])
 542 {
 543     std::string                     rootPath;
 544     std::string                     overlayPath;
 545     std::string                     dylibListFile;
 546     bool                            universal = false;
 547     bool                            force = false;
 548     bool                            searchDisk = false;
 549     bool                            dylibsRemoved = false;
 550     std::string                     cacheDir;
 551     std::unordered_set<std::string> archStrs;
 552     std::unordered_set<std::string> skipDylibs;
 553
 554     // parse command line options
 555     for (int i = 1; i < argc; ++i) {
 556         const char* arg = argv[i];
 557         if (strcmp(arg, "-debug") == 0) {
 558             verbose = true;
 559         }
 560         else if (strcmp(arg, "-verbose") == 0) {
 561             verbose = true;
 562         }
 563         else if (strcmp(arg, "-dont_map_local_symbols") == 0) {
 564             //We are going to ignore this
 565         }
 566         else if (strcmp(arg, "-dylib_list") == 0) {
 567             TERMINATE_IF_LAST_ARG("-dylib_list missing argument");
 568             dylibListFile = argv[++i];
 569         }
 570         else if ((strcmp(arg, "-root") == 0) || (strcmp(arg, "--root") == 0)) {
 571             TERMINATE_IF_LAST_ARG("-root missing path argument\n");
 572             rootPath = argv[++i];
 573         }
 574         else if (strcmp(arg, "-overlay") == 0) {
 575             TERMINATE_IF_LAST_ARG("-overlay missing path argument\n");
 576             overlayPath = argv[++i];
 577         }
 578         else if (strcmp(arg, "-cache_dir") == 0) {
 579             TERMINATE_IF_LAST_ARG("-cache_dir missing path argument\n");
 580             cacheDir = argv[++i];
 581         }
 582         else if (strcmp(arg, "-arch") == 0) {
 583             TERMINATE_IF_LAST_ARG("-arch missing argument\n");
 584             archStrs.insert(argv[++i]);
 585         }
 586         else if (strcmp(arg, "-search_disk") == 0) {
 587             searchDisk = true;
 588         }
 589         else if (strcmp(arg, "-dylibs_removed_in_mastering") == 0) {
 590             dylibsRemoved = true;
 591         }
 592         else if (strcmp(arg, "-force") == 0) {
 593             force = true;
 594         }
 595         else if (strcmp(arg, "-sort_by_name") == 0) {
 596             //No-op, we always do this now
 597         }
 598         else if (strcmp(arg, "-universal_boot") == 0) {
 599             universal = true;
 600         }
 601         else if (strcmp(arg, "-skip") == 0) {
 602             TERMINATE_IF_LAST_ARG("-skip missing argument\n");
 603             skipDylibs.insert(argv[++i]);
 604         }
 605         else {
 606             //usage();
 607             fprintf(stderr, "update_dyld_shared_cache: unknown option: %s\n", arg);
 608             return 1;
 609         }
 610     }
 611
 612     if ( !rootPath.empty() & !overlayPath.empty() ) {
 613         fprintf(stderr, "-root and -overlay cannot be used together\n");
 614         return 1;
 615     }
 616     // canonicalize rootPath
 617     if ( !rootPath.empty() ) {
 618         char resolvedPath[PATH_MAX];
 619         if ( realpath(rootPath.c_str(), resolvedPath) != NULL ) {
 620             rootPath = resolvedPath;
 621         }
 622         // <rdar://problem/33223984> when building closures for boot volume, pathPrefixes should be empty
 623         if ( rootPath == "/" ) {
 624             rootPath = "";
 625         }
 626     }
 627     // canonicalize overlayPath
 628     if ( !overlayPath.empty() ) {
 629         char resolvedPath[PATH_MAX];
 630         if ( realpath(overlayPath.c_str(), resolvedPath) != NULL ) {
 631             overlayPath = resolvedPath;
 632         }
 633     }
 634     //
 635     // pathPrefixes for three modes:
 636     //   1) no options: { "" }           // search only boot volume
 637     //   2) -overlay:   { overlay, "" }  // search overlay, then boot volume
 638     //   3) -root:      { root }         // search only -root volume
 639     //
 640     std::vector<std::string> pathPrefixes;
 641     if ( !overlayPath.empty() )
 642         pathPrefixes.push_back(overlayPath);
 643     pathPrefixes.push_back(rootPath);
 644
 645
 646     if ( cacheDir.empty() ) {
 647         // write cache file into -root or -overlay directory, if used
 648         if ( rootPath != "/" )
 649             cacheDir = rootPath +  MACOSX_DYLD_SHARED_CACHE_DIR;
 650         else if ( !overlayPath.empty()  )
 651             cacheDir = overlayPath +  MACOSX_DYLD_SHARED_CACHE_DIR;
 652         else
 653             cacheDir = MACOSX_DYLD_SHARED_CACHE_DIR;
 654     }
 655
 656     int err = mkpath_np(cacheDir.c_str(), S_IRWXU | S_IRGRP|S_IXGRP | S_IROTH|S_IXOTH);
 657     if ( (err != 0) && (err != EEXIST) ) {
 658         fprintf(stderr, "mkpath_np fail: %d", err);
 659         return 1;
 660     }
 661
 662     if ( archStrs.empty() ) {
 663         if ( universal ) {
 664             // <rdar://problem/26182089> -universal_boot should make all possible dyld caches
 665             archStrs.insert("i386");
 666             archStrs.insert("x86_64");
 667             archStrs.insert("x86_64h");
 668         }
 669         else {
 670             // just make caches for this machine
 671             archStrs.insert("i386");
 672             archStrs.insert(runningOnHaswell() ? "x86_64h" : "x86_64");
 673         }
 674     }
 675
 676     uint64_t t1 = mach_absolute_time();
 677
 678     // find all mach-o files for requested architectures
 679     bool requireDylibsBeRootlessProtected = isProtectedBySIP(cacheDir);
 680     __block std::vector<MappedMachOsByCategory> allFileSets;
 681     if ( archStrs.count("x86_64") )
 682         allFileSets.push_back({"x86_64"});
 683     if ( archStrs.count("x86_64h") )
 684         allFileSets.push_back({"x86_64h"});
 685     if ( archStrs.count("i386") )
 686         allFileSets.push_back({"i386"});
 687     if ( searchDisk )
 688         findAllFiles(pathPrefixes, requireDylibsBeRootlessProtected, allFileSets);
 689     else {
 690         std::unordered_set<std::string> runtimePathsFound;
 691         findOSFilesViaBOMS(pathPrefixes, requireDylibsBeRootlessProtected, allFileSets);
 692     }
 693
 694     // nothing in OS uses i386 dylibs, so only dylibs used by third party apps need to be in cache
 695     for (MappedMachOsByCategory& fileSet : allFileSets) {
 696         pruneCachedDylibs(rootPath, skipDylibs, fileSet);
 697         pruneOtherDylibs(rootPath, fileSet);
 698         pruneExecutables(rootPath, fileSet);
 699    }
 700
 701     uint64_t t2 = mach_absolute_time();
 702     if ( verbose ) {
 703         if ( searchDisk )
 704             fprintf(stderr, "time to scan file system and construct lists of mach-o files: %ums\n", absolutetime_to_milliseconds(t2-t1));
 705         else
 706             fprintf(stderr, "time to read BOM and construct lists of mach-o files: %ums\n", absolutetime_to_milliseconds(t2-t1));
 707     }
 708
 709     // build caches in parallel on machines with at leat 4GB of RAM
 710     uint64_t memSize = 0;
 711     size_t sz = sizeof(memSize);;
 712     bool buildInParallel = false;
 713     if ( sysctlbyname("hw.memsize", &memSize, &sz, NULL, 0) == 0 ) {
 714         if ( memSize >= 0x100000000ULL )
 715             buildInParallel = true;
 716     }
 717     dispatch_queue_t dqueue = buildInParallel ? dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0)
 718                                               : dispatch_queue_create("serial-queue", DISPATCH_QUEUE_SERIAL);
 719
 720     // build all caches
 721     __block bool cacheBuildFailure = false;
 722     __block bool wroteSomeCacheFile = false;
 723     dispatch_apply(allFileSets.size(), dqueue, ^(size_t index) {
 724         MappedMachOsByCategory& fileSet = allFileSets[index];
 725         const std::string outFile = cacheDir + "/dyld_shared_cache_" + fileSet.archName;
 726
 727         DyldSharedCache::MappedMachO (^loader)(const std::string&) = ^DyldSharedCache::MappedMachO(const std::string& runtimePath) {
 728             if ( skipDylibs.count(runtimePath) )
 729                 return DyldSharedCache::MappedMachO();
 730             for (const std::string& prefix : pathPrefixes) {
 731                 std::string fullPath = prefix + runtimePath;
 732                 struct stat statBuf;
 733                 if ( stat(fullPath.c_str(), &statBuf) == 0 ) {
 734                     std::vector<MappedMachOsByCategory> mappedFiles;
 735                     mappedFiles.push_back({fileSet.archName});
 736                     if ( addIfMachO(prefix, runtimePath, statBuf, requireDylibsBeRootlessProtected, mappedFiles) ) {
 737                         if ( !mappedFiles.back().dylibsForCache.empty() )
 738                             return mappedFiles.back().dylibsForCache.back();
 739                     }
 740                 }
 741             }
 742             return DyldSharedCache::MappedMachO();
 743         };
 744         size_t startCount = fileSet.dylibsForCache.size();
 745         std::vector<std::pair<DyldSharedCache::MappedMachO, std::set<std::string>>> excludes;
 746         DyldSharedCache::verifySelfContained(fileSet.dylibsForCache, loader, excludes);
 747         for (size_t i=startCount; i < fileSet.dylibsForCache.size(); ++i) {
 748             fprintf(stderr, "update_dyld_shared_cache: warning: %s not in .bom, but adding required dylib %s\n", fileSet.archName.c_str(), fileSet.dylibsForCache[i].runtimePath.c_str());
 749         }
 750         for (auto& exclude : excludes) {
 751             std::string reasons = "(\"";
 752             for (auto i = exclude.second.begin(); i != exclude.second.end(); ++i) {
 753                 reasons += *i;
 754                 if (i != --exclude.second.end()) {
 755                     reasons += "\", \"";
 756                 }
 757             }
 758             reasons += "\")";
 759             fprintf(stderr, "update_dyld_shared_cache: warning: %s rejected from cached dylibs: %s (%s)\n", fileSet.archName.c_str(), exclude.first.runtimePath.c_str(), reasons.c_str());
 760             fileSet.otherDylibsAndBundles.push_back(exclude.first);
 761         }
 762
 763         // check if cache is already up to date
 764         if ( !force ) {
 765             if ( existingCacheUpToDate(outFile, fileSet.dylibsForCache) )
 766                 return;
 767         }
 768
 769          // add any extra dylibs needed which were not in .bom
 770         fprintf(stderr, "update_dyld_shared_cache: %s incorporating %lu OS dylibs, tracking %lu others, building closures for %lu executables\n", fileSet.archName.c_str(), fileSet.dylibsForCache.size(), fileSet.otherDylibsAndBundles.size(), fileSet.mainExecutables.size());
 771         //for (const DyldSharedCache::MappedMachO& aFile : fileSet.dylibsForCache) {
 772         //    fprintf(stderr, "  %s\n", aFile.runtimePath.c_str());
 773         //}
 774
 775
 776         // build cache new cache file
 777         DyldSharedCache::CreateOptions options;
 778         options.archName                     = fileSet.archName;
 779         options.platform                     = dyld3::Platform::macOS;
 780         options.excludeLocalSymbols          = false;
 781         options.optimizeStubs                = false;
 782         options.optimizeObjC                 = true;
 783         options.codeSigningDigestMode        = DyldSharedCache::SHA256only;
 784         options.dylibsRemovedDuringMastering = dylibsRemoved;
 785         options.inodesAreSameAsRuntime       = true;
 786         options.cacheSupportsASLR            = (fileSet.archName != "i386");
 787         options.forSimulator                 = false;
 788         options.verbose                      = verbose;
 789         options.evictLeafDylibsOnOverflow    = true;
 790         options.pathPrefixes                 = pathPrefixes;
 791         DyldSharedCache::CreateResults results = DyldSharedCache::create(options, fileSet.dylibsForCache, fileSet.otherDylibsAndBundles, fileSet.mainExecutables);
 792
 793         // print any warnings
 794         for (const std::string& warn : results.warnings) {
 795             fprintf(stderr, "update_dyld_shared_cache: warning: %s %s\n", fileSet.archName.c_str(), warn.c_str());
 796         }
 797         if ( !results.errorMessage.empty() ) {
 798             // print error (if one)
 799             fprintf(stderr, "update_dyld_shared_cache: %s\n", results.errorMessage.c_str());
 800             cacheBuildFailure = true;
 801         }
 802         else {
 803             // save new cache file to disk and write new .map file
 804             assert(results.cacheContent != nullptr);
 805             if ( !safeSave(results.cacheContent, results.cacheLength, outFile) )
 806                 cacheBuildFailure = true;
 807             if ( !cacheBuildFailure ) {
 808                 std::string mapStr = results.cacheContent->mapFile();
 809                 std::string outFileMap = cacheDir + "/dyld_shared_cache_" + fileSet.archName + ".map";
 810                 safeSave(mapStr.c_str(), mapStr.size(), outFileMap);
 811                 wroteSomeCacheFile = true;
 812             }
 813             // free created cache buffer
 814             vm_deallocate(mach_task_self(), (vm_address_t)results.cacheContent, results.cacheLength);
 815         }
 816     });
 817
 818
 819     // Save off spintrace data
 820     if ( wroteSomeCacheFile ) {
 821         void* h = dlopen("/usr/lib/libdscsym.dylib", 0);
 822         if ( h != nullptr ) {
 823             typedef int (*dscym_func)(const char*);
 824             dscym_func func = (dscym_func)dlsym(h, "dscsym_save_dscsyms_for_current_caches");
 825             std::string nuggetRoot = rootPath;
 826             if ( nuggetRoot.empty() )
 827                  nuggetRoot = overlayPath;
 828             if ( nuggetRoot.empty() )
 829                  nuggetRoot = "/";
 830             (*func)(nuggetRoot.c_str());
 831         }
 832     }
 833
 834
 835     // we could unmap all input files, but tool is about to quit
 836
 837     return (cacheBuildFailure ? 1 : 0);
 838 }
 839