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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 <unistd.h>
26 #include <dirent.h>
27 #include <sys/errno.h>
28 #include <sys/fcntl.h>
29 #include <sys/param.h>
30 #include <sys/types.h>
31 #include <sys/stat.h>
32 #include <mach/mach.h>
33 #include <mach/mach_vm.h>
34 #include <mach/mach_time.h>
35 #include <mach/shared_region.h>
36 #include <apfs/apfs_fsctl.h>
37 #include <iostream>
38
39 #include <CommonCrypto/CommonHMAC.h>
40 #include <CommonCrypto/CommonDigest.h>
41 #include <CommonCrypto/CommonDigestSPI.h>
42
43 #include "mach-o/dyld_priv.h"
44 #include "ClosureBuilder.h"
45 #include "Closure.h"
46 #include "ClosureFileSystemNull.h"
47 #include "CodeSigningTypes.h"
48 #include "MachOFileAbstraction.hpp"
49 #include "SharedCacheBuilder.h"
50 #include "RootsChecker.h"
51 #include "IMPCachesBuilder.hpp"
52
53 #include "FileUtils.h"
54 #include "StringUtils.h"
55 #include "Trie.hpp"
56
57 #if __has_include("dyld_cache_config.h")
58 #include "dyld_cache_config.h"
59 #else
60 #define ARM_SHARED_REGION_START 0x1A000000ULL
61 #define ARM_SHARED_REGION_SIZE 0x26000000ULL
62 #define ARM64_SHARED_REGION_START 0x180000000ULL
63 #define ARM64_SHARED_REGION_SIZE 0x100000000ULL
64 #endif
65
66 #if ARM64_SHARED_REGION_START == 0x7FFF00000000
67 #define ARM64_DELTA_MASK 0x00FF000000000000
68 #else
69 #define ARM64_DELTA_MASK 0x00FFFF0000000000
70 #endif
71
72 #ifndef ARM64_32_SHARED_REGION_START
73 #define ARM64_32_SHARED_REGION_START 0x1A000000ULL
74 #define ARM64_32_SHARED_REGION_SIZE 0x26000000ULL
75 #endif
76
77 #define ARMV7K_CHAIN_BITS 0xC0000000
78
79 #if BUILDING_UPDATE_DYLD_CACHE_BUILDER
80 #define DISCONTIGUOUS_RX 0x7FFF20000000ULL
81 #else
82 #define DISCONTIGUOUS_RX 0x7FFF20000000ULL // size for MRM builder
83 #endif
84 #define DISCONTIGUOUS_RW 0x7FFF80000000ULL
85 #define DISCONTIGUOUS_RO 0x7FFFC0000000ULL
86 #define DISCONTIGUOUS_RX_SIZE (DISCONTIGUOUS_RW - DISCONTIGUOUS_RX)
87 #define DISCONTIGUOUS_RW_SIZE 0x40000000
88 #define DISCONTIGUOUS_RO_SIZE 0x3FE00000
89
90 const SharedCacheBuilder::ArchLayout SharedCacheBuilder::_s_archLayout[] = {
91 { DISCONTIGUOUS_RX, 0xEFE00000ULL, 0x40000000, 0x00FFFF0000000000, "x86_64", CS_PAGE_SIZE_4K, 14, 2, true, true, true },
92 { DISCONTIGUOUS_RX, 0xEFE00000ULL, 0x40000000, 0x00FFFF0000000000, "x86_64h", CS_PAGE_SIZE_4K, 14, 2, true, true, true },
93 { SHARED_REGION_BASE_I386, SHARED_REGION_SIZE_I386, 0x00200000, 0x0, "i386", CS_PAGE_SIZE_4K, 12, 0, false, false, true },
94 { ARM64_SHARED_REGION_START, ARM64_SHARED_REGION_SIZE, 0x02000000, ARM64_DELTA_MASK, "arm64", CS_PAGE_SIZE_4K, 14, 2, false, true, false },
95 #if SUPPORT_ARCH_arm64e
96 { ARM64_SHARED_REGION_START, ARM64_SHARED_REGION_SIZE, 0x02000000, ARM64_DELTA_MASK, "arm64e", CS_PAGE_SIZE_16K, 14, 2, false, true, false },
97 #endif
98 #if SUPPORT_ARCH_arm64_32
99 { ARM64_32_SHARED_REGION_START, ARM64_32_SHARED_REGION_SIZE, 0x02000000, 0xC0000000, "arm64_32", CS_PAGE_SIZE_16K, 14, 6, false, false, true },
100 #endif
101 { ARM_SHARED_REGION_START, ARM_SHARED_REGION_SIZE, 0x02000000, 0xE0000000, "armv7s", CS_PAGE_SIZE_4K, 14, 4, false, false, true },
102 { ARM_SHARED_REGION_START, ARM_SHARED_REGION_SIZE, 0x00400000, ARMV7K_CHAIN_BITS, "armv7k", CS_PAGE_SIZE_4K, 14, 4, false, false, true },
103 { 0x40000000, 0x40000000, 0x02000000, 0x0, "sim-x86", CS_PAGE_SIZE_4K, 14, 0, false, false, true }
104 };
105
106 // These are functions that are interposed by Instruments.app or ASan
107 const char* const SharedCacheBuilder::_s_neverStubEliminateSymbols[] = {
108 "___bzero",
109 "___cxa_atexit",
110 "___cxa_throw",
111 "__longjmp",
112 "__objc_autoreleasePoolPop",
113 "_accept",
114 "_access",
115 "_asctime",
116 "_asctime_r",
117 "_asprintf",
118 "_atoi",
119 "_atol",
120 "_atoll",
121 "_calloc",
122 "_chmod",
123 "_chown",
124 "_close",
125 "_confstr",
126 "_ctime",
127 "_ctime_r",
128 "_dispatch_after",
129 "_dispatch_after_f",
130 "_dispatch_async",
131 "_dispatch_async_f",
132 "_dispatch_barrier_async_f",
133 "_dispatch_group_async",
134 "_dispatch_group_async_f",
135 "_dispatch_source_set_cancel_handler",
136 "_dispatch_source_set_event_handler",
137 "_dispatch_sync_f",
138 "_dlclose",
139 "_dlopen",
140 "_dup",
141 "_dup2",
142 "_endgrent",
143 "_endpwent",
144 "_ether_aton",
145 "_ether_hostton",
146 "_ether_line",
147 "_ether_ntoa",
148 "_ether_ntohost",
149 "_fchmod",
150 "_fchown",
151 "_fclose",
152 "_fdopen",
153 "_fflush",
154 "_fopen",
155 "_fork",
156 "_fprintf",
157 "_free",
158 "_freopen",
159 "_frexp",
160 "_frexpf",
161 "_frexpl",
162 "_fscanf",
163 "_fstat",
164 "_fstatfs",
165 "_fstatfs64",
166 "_fsync",
167 "_ftime",
168 "_getaddrinfo",
169 "_getattrlist",
170 "_getcwd",
171 "_getgrent",
172 "_getgrgid",
173 "_getgrgid_r",
174 "_getgrnam",
175 "_getgrnam_r",
176 "_getgroups",
177 "_gethostbyaddr",
178 "_gethostbyname",
179 "_gethostbyname2",
180 "_gethostent",
181 "_getifaddrs",
182 "_getitimer",
183 "_getnameinfo",
184 "_getpass",
185 "_getpeername",
186 "_getpwent",
187 "_getpwnam",
188 "_getpwnam_r",
189 "_getpwuid",
190 "_getpwuid_r",
191 "_getsockname",
192 "_getsockopt",
193 "_gmtime",
194 "_gmtime_r",
195 "_if_indextoname",
196 "_if_nametoindex",
197 "_index",
198 "_inet_aton",
199 "_inet_ntop",
200 "_inet_pton",
201 "_initgroups",
202 "_ioctl",
203 "_lchown",
204 "_lgamma",
205 "_lgammaf",
206 "_lgammal",
207 "_link",
208 "_listxattr",
209 "_localtime",
210 "_localtime_r",
211 "_longjmp",
212 "_lseek",
213 "_lstat",
214 "_malloc",
215 "_malloc_create_zone",
216 "_malloc_default_purgeable_zone",
217 "_malloc_default_zone",
218 "_malloc_destroy_zone",
219 "_malloc_good_size",
220 "_malloc_make_nonpurgeable",
221 "_malloc_make_purgeable",
222 "_malloc_set_zone_name",
223 "_malloc_zone_from_ptr",
224 "_mbsnrtowcs",
225 "_mbsrtowcs",
226 "_mbstowcs",
227 "_memchr",
228 "_memcmp",
229 "_memcpy",
230 "_memmove",
231 "_memset",
232 "_mktime",
233 "_mlock",
234 "_mlockall",
235 "_modf",
236 "_modff",
237 "_modfl",
238 "_munlock",
239 "_munlockall",
240 "_objc_autoreleasePoolPop",
241 "_objc_setProperty",
242 "_objc_setProperty_atomic",
243 "_objc_setProperty_atomic_copy",
244 "_objc_setProperty_nonatomic",
245 "_objc_setProperty_nonatomic_copy",
246 "_objc_storeStrong",
247 "_open",
248 "_opendir",
249 "_poll",
250 "_posix_memalign",
251 "_pread",
252 "_printf",
253 "_pthread_attr_getdetachstate",
254 "_pthread_attr_getguardsize",
255 "_pthread_attr_getinheritsched",
256 "_pthread_attr_getschedparam",
257 "_pthread_attr_getschedpolicy",
258 "_pthread_attr_getscope",
259 "_pthread_attr_getstack",
260 "_pthread_attr_getstacksize",
261 "_pthread_condattr_getpshared",
262 "_pthread_create",
263 "_pthread_getschedparam",
264 "_pthread_join",
265 "_pthread_mutex_lock",
266 "_pthread_mutex_unlock",
267 "_pthread_mutexattr_getprioceiling",
268 "_pthread_mutexattr_getprotocol",
269 "_pthread_mutexattr_getpshared",
270 "_pthread_mutexattr_gettype",
271 "_pthread_rwlockattr_getpshared",
272 "_pwrite",
273 "_rand_r",
274 "_read",
275 "_readdir",
276 "_readdir_r",
277 "_readv",
278 "_readv$UNIX2003",
279 "_realloc",
280 "_realpath",
281 "_recv",
282 "_recvfrom",
283 "_recvmsg",
284 "_remquo",
285 "_remquof",
286 "_remquol",
287 "_scanf",
288 "_send",
289 "_sendmsg",
290 "_sendto",
291 "_setattrlist",
292 "_setgrent",
293 "_setitimer",
294 "_setlocale",
295 "_setpwent",
296 "_shm_open",
297 "_shm_unlink",
298 "_sigaction",
299 "_sigemptyset",
300 "_sigfillset",
301 "_siglongjmp",
302 "_signal",
303 "_sigpending",
304 "_sigprocmask",
305 "_sigwait",
306 "_snprintf",
307 "_sprintf",
308 "_sscanf",
309 "_stat",
310 "_statfs",
311 "_statfs64",
312 "_strcasecmp",
313 "_strcat",
314 "_strchr",
315 "_strcmp",
316 "_strcpy",
317 "_strdup",
318 "_strerror",
319 "_strerror_r",
320 "_strlen",
321 "_strncasecmp",
322 "_strncat",
323 "_strncmp",
324 "_strncpy",
325 "_strptime",
326 "_strtoimax",
327 "_strtol",
328 "_strtoll",
329 "_strtoumax",
330 "_tempnam",
331 "_time",
332 "_times",
333 "_tmpnam",
334 "_tsearch",
335 "_unlink",
336 "_valloc",
337 "_vasprintf",
338 "_vfprintf",
339 "_vfscanf",
340 "_vprintf",
341 "_vscanf",
342 "_vsnprintf",
343 "_vsprintf",
344 "_vsscanf",
345 "_wait",
346 "_wait$UNIX2003",
347 "_wait3",
348 "_wait4",
349 "_waitid",
350 "_waitid$UNIX2003",
351 "_waitpid",
352 "_waitpid$UNIX2003",
353 "_wcslen",
354 "_wcsnrtombs",
355 "_wcsrtombs",
356 "_wcstombs",
357 "_wordexp",
358 "_write",
359 "_writev",
360 "_writev$UNIX2003",
361 // <rdar://problem/22050956> always use stubs for C++ symbols that can be overridden
362 "__ZdaPv",
363 "__ZdlPv",
364 "__Znam",
365 "__Znwm",
366
367 nullptr
368 };
369
370
371 inline uint32_t absolutetime_to_milliseconds(uint64_t abstime)
372 {
373 return (uint32_t)(abstime/1000/1000);
374 }
375
376 // Handles building a list of input files to the SharedCacheBuilder itself.
377 class CacheInputBuilder {
378 public:
379 CacheInputBuilder(const dyld3::closure::FileSystem& fileSystem,
380 const dyld3::GradedArchs& archs, dyld3::Platform reqPlatform)
381 : fileSystem(fileSystem), reqArchs(archs), reqPlatform(reqPlatform) { }
382
383 // Loads and maps any MachOs in the given list of files.
384 void loadMachOs(std::vector<CacheBuilder::InputFile>& inputFiles,
385 std::vector<CacheBuilder::LoadedMachO>& dylibsToCache,
386 std::vector<CacheBuilder::LoadedMachO>& otherDylibs,
387 std::vector<CacheBuilder::LoadedMachO>& executables,
388 std::vector<CacheBuilder::LoadedMachO>& couldNotLoadFiles) {
389
390 std::map<std::string, uint64_t> dylibInstallNameMap;
391 for (CacheBuilder::InputFile& inputFile : inputFiles) {
392 char realerPath[MAXPATHLEN];
393 dyld3::closure::LoadedFileInfo loadedFileInfo = dyld3::MachOAnalyzer::load(inputFile.diag, fileSystem, inputFile.path, reqArchs, reqPlatform, realerPath);
394 if ( (reqPlatform == dyld3::Platform::macOS) && inputFile.diag.hasError() ) {
395 // Try again with iOSMac
396 inputFile.diag.clearError();
397 loadedFileInfo = dyld3::MachOAnalyzer::load(inputFile.diag, fileSystem, inputFile.path, reqArchs, dyld3::Platform::iOSMac, realerPath);
398 }
399 const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*)loadedFileInfo.fileContent;
400 if (ma == nullptr) {
401 couldNotLoadFiles.emplace_back((CacheBuilder::LoadedMachO){ DyldSharedCache::MappedMachO(), loadedFileInfo, &inputFile });
402 continue;
403 }
404
405 DyldSharedCache::MappedMachO mappedFile(inputFile.path, ma, loadedFileInfo.sliceLen, false, false,
406 loadedFileInfo.sliceOffset, loadedFileInfo.mtime, loadedFileInfo.inode);
407
408 // The file can be loaded with the given slice, but we may still want to exlude it from the cache.
409 if (ma->isDylib()) {
410 std::string installName = ma->installName();
411
412 const char* dylibPath = inputFile.path;
413 if ( (installName != inputFile.path) && (reqPlatform == dyld3::Platform::macOS) ) {
414 // We now typically require that install names and paths match. However symlinks may allow us to bring in a path which
415 // doesn't match its install name.
416 // For example:
417 // /usr/lib/libstdc++.6.0.9.dylib is a real file with install name /usr/lib/libstdc++.6.dylib
418 // /usr/lib/libstdc++.6.dylib is a symlink to /usr/lib/libstdc++.6.0.9.dylib
419 // So long as we add both paths (with one as an alias) then this will work, even if dylibs are removed from disk
420 // but the symlink remains.
421 char resolvedSymlinkPath[PATH_MAX];
422 if ( fileSystem.getRealPath(installName.c_str(), resolvedSymlinkPath) ) {
423 if (!strcmp(resolvedSymlinkPath, inputFile.path)) {
424 // Symlink is the install name and points to the on-disk dylib
425 //fprintf(stderr, "Symlink works: %s == %s\n", inputFile.path, installName.c_str());
426 dylibPath = installName.c_str();
427 }
428 }
429 }
430
431 if (!ma->canBePlacedInDyldCache(dylibPath, ^(const char* msg) {
432 inputFile.diag.warning("Dylib located at '%s' cannot be placed in cache because: %s", inputFile.path, msg);
433 })) {
434
435 if (!ma->canHavePrecomputedDlopenClosure(inputFile.path, ^(const char* msg) {
436 inputFile.diag.verbose("Dylib located at '%s' cannot prebuild dlopen closure in cache because: %s", inputFile.path, msg);
437 }) ) {
438 fileSystem.unloadFile(loadedFileInfo);
439 continue;
440 }
441 otherDylibs.emplace_back((CacheBuilder::LoadedMachO){ mappedFile, loadedFileInfo, &inputFile });
442 continue;
443 }
444
445 // Otherwise see if we have another file with this install name
446 auto iteratorAndInserted = dylibInstallNameMap.insert(std::make_pair(installName, dylibsToCache.size()));
447 if (iteratorAndInserted.second) {
448 // We inserted the dylib so we haven't seen another with this name.
449 if (installName[0] != '@' && installName != inputFile.path) {
450 inputFile.diag.warning("Dylib located at '%s' has installname '%s'", inputFile.path, installName.c_str());
451 }
452
453 dylibsToCache.emplace_back((CacheBuilder::LoadedMachO){ mappedFile, loadedFileInfo, &inputFile });
454 } else {
455 // We didn't insert this one so we've seen it before.
456 CacheBuilder::LoadedMachO& previousLoadedMachO = dylibsToCache[iteratorAndInserted.first->second];
457 inputFile.diag.warning("Multiple dylibs claim installname '%s' ('%s' and '%s')", installName.c_str(), inputFile.path, previousLoadedMachO.mappedFile.runtimePath.c_str());
458
459 // This is the "Good" one, overwrite
460 if (inputFile.path == installName) {
461 // Unload the old one
462 fileSystem.unloadFile(previousLoadedMachO.loadedFileInfo);
463
464 // And replace with this one.
465 previousLoadedMachO.mappedFile = mappedFile;
466 previousLoadedMachO.loadedFileInfo = loadedFileInfo;
467 }
468 }
469 } else if (ma->isBundle()) {
470
471 if (!ma->canHavePrecomputedDlopenClosure(inputFile.path, ^(const char* msg) {
472 inputFile.diag.verbose("Dylib located at '%s' cannot prebuild dlopen closure in cache because: %s", inputFile.path, msg);
473 }) ) {
474 fileSystem.unloadFile(loadedFileInfo);
475 continue;
476 }
477 otherDylibs.emplace_back((CacheBuilder::LoadedMachO){ mappedFile, loadedFileInfo, &inputFile });
478 } else if (ma->isDynamicExecutable()) {
479
480 // Let the platform exclude the file before we do anything else.
481 if (platformExcludesExecutablePath(inputFile.path)) {
482 inputFile.diag.verbose("Platform excluded file\n");
483 fileSystem.unloadFile(loadedFileInfo);
484 continue;
485 }
486 executables.emplace_back((CacheBuilder::LoadedMachO){ mappedFile, loadedFileInfo, &inputFile });
487 } else {
488 inputFile.diag.verbose("Unsupported mach file type\n");
489 fileSystem.unloadFile(loadedFileInfo);
490 }
491 }
492 }
493
494 private:
495
496 static bool platformExcludesExecutablePath_macOS(const std::string& path) {
497 // We no longer support ROSP, so skip all paths which start with the special prefix
498 if ( startsWith(path, "/System/Library/Templates/Data/") )
499 return true;
500
501 static const char* sAllowedPrefixes[] = {
502 "/bin/",
503 "/sbin/",
504 "/usr/",
505 "/System/",
506 "/Library/Apple/System/",
507 "/Library/Apple/usr/",
508 "/System/Applications/Safari.app/",
509 "/Library/CoreMediaIO/Plug-Ins/DAL/" // temp until plugins moved or closured working
510 };
511
512 bool inSearchDir = false;
513 for (const char* searchDir : sAllowedPrefixes ) {
514 if ( strncmp(searchDir, path.c_str(), strlen(searchDir)) == 0 ) {
515 inSearchDir = true;
516 break;
517 }
518 }
519
520 return !inSearchDir;
521 }
522
523 // Returns true if the current platform requires that this path be excluded from the shared cache
524 // Note that this overrides any exclusion from anywhere else.
525 bool platformExcludesExecutablePath(const std::string& path) {
526 switch (reqPlatform) {
527 case dyld3::Platform::unknown:
528 return false;
529 case dyld3::Platform::macOS:
530 return platformExcludesExecutablePath_macOS(path);
531 case dyld3::Platform::iOS:
532 return false;
533 case dyld3::Platform::tvOS:
534 return false;
535 case dyld3::Platform::watchOS:
536 return false;
537 case dyld3::Platform::bridgeOS:
538 return false;
539 case dyld3::Platform::iOSMac:
540 return platformExcludesExecutablePath_macOS(path);
541 case dyld3::Platform::iOS_simulator:
542 return false;
543 case dyld3::Platform::tvOS_simulator:
544 return false;
545 case dyld3::Platform::watchOS_simulator:
546 return false;
547 case dyld3::Platform::driverKit:
548 return false;
549 }
550 }
551
552 const dyld3::closure::FileSystem& fileSystem;
553 const dyld3::GradedArchs& reqArchs;
554 dyld3::Platform reqPlatform;
555 };
556
557 SharedCacheBuilder::SharedCacheBuilder(const DyldSharedCache::CreateOptions& options,
558 const dyld3::closure::FileSystem& fileSystem)
559 : CacheBuilder(options, fileSystem) {
560
561 std::string targetArch = options.archs->name();
562 if ( options.forSimulator && (options.archs == &dyld3::GradedArchs::i386) )
563 targetArch = "sim-x86";
564
565 for (const ArchLayout& layout : _s_archLayout) {
566 if ( layout.archName == targetArch ) {
567 _archLayout = &layout;
568 _is64 = _archLayout->is64;
569 break;
570 }
571 }
572
573 if (!_archLayout) {
574 _diagnostics.error("Tool was built without support for: '%s'", targetArch.c_str());
575 }
576 }
577
578 static void verifySelfContained(const dyld3::closure::FileSystem& fileSystem,
579 std::vector<CacheBuilder::LoadedMachO>& dylibsToCache,
580 std::vector<CacheBuilder::LoadedMachO>& otherDylibs,
581 std::vector<CacheBuilder::LoadedMachO>& couldNotLoadFiles)
582 {
583 // build map of dylibs
584 __block std::map<std::string, const CacheBuilder::LoadedMachO*> knownDylibs;
585 __block std::map<std::string, const CacheBuilder::LoadedMachO*> allDylibs;
586 for (const CacheBuilder::LoadedMachO& dylib : dylibsToCache) {
587 knownDylibs.insert({ dylib.mappedFile.runtimePath, &dylib });
588 allDylibs.insert({ dylib.mappedFile.runtimePath, &dylib });
589 if (const char* installName = dylib.mappedFile.mh->installName()) {
590 knownDylibs.insert({ installName, &dylib });
591 allDylibs.insert({ installName, &dylib });
592 }
593 }
594
595 for (const CacheBuilder::LoadedMachO& dylib : otherDylibs) {
596 allDylibs.insert({ dylib.mappedFile.runtimePath, &dylib });
597 if (const char* installName = dylib.mappedFile.mh->installName())
598 allDylibs.insert({ installName, &dylib });
599 }
600
601 for (const CacheBuilder::LoadedMachO& dylib : couldNotLoadFiles) {
602 allDylibs.insert({ dylib.inputFile->path, &dylib });
603 }
604
605 // Exclude bad unzippered twins. These are where a zippered binary links
606 // an unzippered twin
607 std::unordered_map<std::string, std::string> macOSPathToTwinPath;
608 for (const CacheBuilder::LoadedMachO& dylib : dylibsToCache) {
609 macOSPathToTwinPath[dylib.mappedFile.runtimePath] = "";
610 }
611 for (const CacheBuilder::LoadedMachO& dylib : dylibsToCache) {
612 if ( startsWith(dylib.mappedFile.runtimePath, "/System/iOSSupport/") ) {
613 std::string tail = dylib.mappedFile.runtimePath.substr(18);
614 if ( macOSPathToTwinPath.find(tail) != macOSPathToTwinPath.end() )
615 macOSPathToTwinPath[tail] = dylib.mappedFile.runtimePath;
616 }
617 }
618
619 __block std::map<std::string, std::set<std::string>> badDylibs;
620 for (const CacheBuilder::LoadedMachO& dylib : dylibsToCache) {
621 if ( badDylibs.count(dylib.mappedFile.runtimePath) != 0 )
622 continue;
623 if ( dylib.mappedFile.mh->isZippered() ) {
624 dylib.mappedFile.mh->forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool& stop) {
625 auto macOSAndTwinPath = macOSPathToTwinPath.find(loadPath);
626 if ( macOSAndTwinPath != macOSPathToTwinPath.end() ) {
627 const std::string& twinPath = macOSAndTwinPath->second;
628 if ( badDylibs.count(twinPath) != 0 )
629 return;
630 knownDylibs.erase(twinPath);
631 badDylibs[twinPath].insert(std::string("evicting UIKitForMac binary as it is linked by zippered binary '") + dylib.mappedFile.runtimePath + "'");
632 }
633 });
634 }
635 }
636
637 // HACK: Exclude some dylibs and transitive deps for now until we have project fixes
638 __block std::set<std::string> badProjects;
639 badProjects.insert("/System/Library/PrivateFrameworks/TuriCore.framework/Versions/A/TuriCore");
640 badProjects.insert("/System/Library/PrivateFrameworks/UHASHelloExtensionPoint-macOS.framework/Versions/A/UHASHelloExtensionPoint-macOS");
641
642 // check all dependencies to assure every dylib in cache only depends on other dylibs in cache
643 __block bool doAgain = true;
644 while ( doAgain ) {
645 doAgain = false;
646 // scan dylib list making sure all dependents are in dylib list
647 for (const CacheBuilder::LoadedMachO& dylib : dylibsToCache) {
648 if ( badDylibs.count(dylib.mappedFile.runtimePath) != 0 )
649 continue;
650 if ( badProjects.count(dylib.mappedFile.runtimePath) != 0 )
651 continue;
652 dylib.mappedFile.mh->forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool& stop) {
653 if (isWeak)
654 return;
655 if ( badProjects.count(loadPath) != 0 ) {
656 // We depend on a bad dylib, so add this one to the list too
657 badProjects.insert(dylib.mappedFile.runtimePath);
658 badProjects.insert(dylib.mappedFile.mh->installName());
659 knownDylibs.erase(dylib.mappedFile.runtimePath);
660 knownDylibs.erase(dylib.mappedFile.mh->installName());
661 badDylibs[dylib.mappedFile.runtimePath].insert(std::string("Depends on bad project '") + loadPath + "'");
662 doAgain = true;
663 return;
664 }
665 char resolvedSymlinkPath[PATH_MAX];
666 if ( knownDylibs.count(loadPath) == 0 ) {
667 // The loadPath was embedded when the dylib was built, but we may be in the process of moving
668 // a dylib with symlinks from old to new paths
669 // In this case, the realpath will tell us the new location
670 if ( fileSystem.getRealPath(loadPath, resolvedSymlinkPath) ) {
671 if ( strcmp(resolvedSymlinkPath, loadPath) != 0 ) {
672 loadPath = resolvedSymlinkPath;
673 }
674 }
675 }
676 if ( knownDylibs.count(loadPath) == 0 ) {
677 badDylibs[dylib.mappedFile.runtimePath].insert(std::string("Could not find dependency '") + loadPath + "'");
678 knownDylibs.erase(dylib.mappedFile.runtimePath);
679 knownDylibs.erase(dylib.mappedFile.mh->installName());
680 doAgain = true;
681 }
682 });
683 }
684 }
685
686 // Now walk the dylibs which depend on missing dylibs and see if any of them are required binaries.
687 for (auto badDylibsIterator : badDylibs) {
688 const std::string& dylibRuntimePath = badDylibsIterator.first;
689 auto requiredDylibIterator = allDylibs.find(dylibRuntimePath);
690 if (requiredDylibIterator == allDylibs.end())
691 continue;
692 if (!requiredDylibIterator->second->inputFile->mustBeIncluded())
693 continue;
694 // This dylib is required so mark all dependencies as requried too
695 __block std::vector<const CacheBuilder::LoadedMachO*> worklist;
696 worklist.push_back(requiredDylibIterator->second);
697 while (!worklist.empty()) {
698 const CacheBuilder::LoadedMachO* dylib = worklist.back();
699 worklist.pop_back();
700 if (!dylib->mappedFile.mh)
701 continue;
702 dylib->mappedFile.mh->forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool& stop) {
703 if (isWeak)
704 return;
705 auto dylibIterator = allDylibs.find(loadPath);
706 if (dylibIterator != allDylibs.end()) {
707 if (dylibIterator->second->inputFile->state == CacheBuilder::InputFile::Unset) {
708 dylibIterator->second->inputFile->state = CacheBuilder::InputFile::MustBeIncludedForDependent;
709 worklist.push_back(dylibIterator->second);
710 }
711 }
712 });
713 }
714 }
715
716 // FIXME: Make this an option we can pass in
717 const bool evictLeafDylibs = true;
718 if (evictLeafDylibs) {
719 doAgain = true;
720 while ( doAgain ) {
721 doAgain = false;
722
723 // build count of how many references there are to each dylib
724 __block std::set<std::string> referencedDylibs;
725 for (const CacheBuilder::LoadedMachO& dylib : dylibsToCache) {
726 if ( badDylibs.count(dylib.mappedFile.runtimePath) != 0 )
727 continue;
728 dylib.mappedFile.mh->forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool &stop) {
729 referencedDylibs.insert(loadPath);
730 });
731 }
732
733 // find all dylibs not referenced
734 for (const CacheBuilder::LoadedMachO& dylib : dylibsToCache) {
735 if ( badDylibs.count(dylib.mappedFile.runtimePath) != 0 )
736 continue;
737 const char* installName = dylib.mappedFile.mh->installName();
738 if ( (referencedDylibs.count(installName) == 0) && (dylib.inputFile->state == CacheBuilder::InputFile::MustBeExcludedIfUnused) ) {
739 badDylibs[dylib.mappedFile.runtimePath].insert(std::string("It has been explicitly excluded as it is unused"));
740 doAgain = true;
741 }
742 }
743 }
744 }
745
746 // Move bad dylibs from dylibs to cache to other dylibs.
747 for (const CacheBuilder::LoadedMachO& dylib : dylibsToCache) {
748 auto i = badDylibs.find(dylib.mappedFile.runtimePath);
749 if ( i != badDylibs.end()) {
750 otherDylibs.push_back(dylib);
751 for (const std::string& reason : i->second )
752 otherDylibs.back().inputFile->diag.warning("Dylib located at '%s' not placed in shared cache because: %s", dylib.mappedFile.runtimePath.c_str(), reason.c_str());
753 }
754 }
755
756 const auto& badDylibsLambdaRef = badDylibs;
757 dylibsToCache.erase(std::remove_if(dylibsToCache.begin(), dylibsToCache.end(), [&](const CacheBuilder::LoadedMachO& dylib) {
758 if (badDylibsLambdaRef.find(dylib.mappedFile.runtimePath) != badDylibsLambdaRef.end())
759 return true;
760 return false;
761 }), dylibsToCache.end());
762 }
763
764 // This is the new build API which takes the raw files (which could be FAT) and tries to build a cache from them.
765 // We should remove the other build() method, or make it private so that this can wrap it.
766 void SharedCacheBuilder::build(std::vector<CacheBuilder::InputFile>& inputFiles,
767 std::vector<DyldSharedCache::FileAlias>& aliases) {
768 // First filter down to files which are actually MachO's
769 CacheInputBuilder cacheInputBuilder(_fileSystem, *_options.archs, _options.platform);
770
771 std::vector<LoadedMachO> dylibsToCache;
772 std::vector<LoadedMachO> otherDylibs;
773 std::vector<LoadedMachO> executables;
774 std::vector<LoadedMachO> couldNotLoadFiles;
775 cacheInputBuilder.loadMachOs(inputFiles, dylibsToCache, otherDylibs, executables, couldNotLoadFiles);
776
777 verifySelfContained(_fileSystem, dylibsToCache, otherDylibs, couldNotLoadFiles);
778
779 // Check for required binaries before we try to build the cache
780 if (!_diagnostics.hasError()) {
781 // If we succeeded in building, then now see if there was a missing required file, and if so why its missing.
782 std::string errorString;
783 for (const LoadedMachO& dylib : otherDylibs) {
784 if (dylib.inputFile->mustBeIncluded()) {
785 // An error loading a required file must be propagated up to the top level diagnostic handler.
786 bool gotWarning = false;
787 for (const std::string& warning : dylib.inputFile->diag.warnings()) {
788 gotWarning = true;
789 std::string message = warning;
790 if (message.back() == '\n')
791 message.pop_back();
792 if (!errorString.empty())
793 errorString += "ERROR: ";
794 errorString += "Required binary was not included in the shared cache '" + std::string(dylib.inputFile->path) + "' because: " + message + "\n";
795 }
796 if (!gotWarning) {
797 if (!errorString.empty())
798 errorString += "ERROR: ";
799 errorString += "Required binary was not included in the shared cache '" + std::string(dylib.inputFile->path) + "' because: 'unknown error. Please report to dyld'\n";
800 }
801 }
802 }
803 for (const LoadedMachO& dylib : couldNotLoadFiles) {
804 if (dylib.inputFile->mustBeIncluded()) {
805 if (dylib.inputFile->diag.hasError()) {
806 if (!errorString.empty())
807 errorString += "ERROR: ";
808 errorString += "Required binary was not included in the shared cache '" + std::string(dylib.inputFile->path) + "' because: " + dylib.inputFile->diag.errorMessage() + "\n";
809 } else {
810 if (!errorString.empty())
811 errorString += "ERROR: ";
812 errorString += "Required binary was not included in the shared cache '" + std::string(dylib.inputFile->path) + "' because: 'unknown error. Please report to dyld'\n";
813
814 }
815 }
816 }
817 if (!errorString.empty()) {
818 _diagnostics.error("%s", errorString.c_str());
819 }
820 }
821
822 if (!_diagnostics.hasError())
823 build(dylibsToCache, otherDylibs, executables, aliases);
824
825 if (!_diagnostics.hasError()) {
826 // If we succeeded in building, then now see if there was a missing required file, and if so why its missing.
827 std::string errorString;
828 for (CacheBuilder::InputFile& inputFile : inputFiles) {
829 if (inputFile.mustBeIncluded() && inputFile.diag.hasError()) {
830 // An error loading a required file must be propagated up to the top level diagnostic handler.
831 std::string message = inputFile.diag.errorMessage();
832 if (message.back() == '\n')
833 message.pop_back();
834 errorString += "Required binary was not included in the shared cache '" + std::string(inputFile.path) + "' because: " + message + "\n";
835 }
836 }
837 if (!errorString.empty()) {
838 _diagnostics.error("%s", errorString.c_str());
839 }
840 }
841
842 // Add all the warnings from the input files to the top level warnings on the main diagnostics object.
843 for (CacheBuilder::InputFile& inputFile : inputFiles) {
844 for (const std::string& warning : inputFile.diag.warnings())
845 _diagnostics.warning("%s", warning.c_str());
846 }
847
848 // Clean up the loaded files
849 for (LoadedMachO& loadedMachO : dylibsToCache)
850 _fileSystem.unloadFile(loadedMachO.loadedFileInfo);
851 for (LoadedMachO& loadedMachO : otherDylibs)
852 _fileSystem.unloadFile(loadedMachO.loadedFileInfo);
853 for (LoadedMachO& loadedMachO : executables)
854 _fileSystem.unloadFile(loadedMachO.loadedFileInfo);
855 }
856
857 void SharedCacheBuilder::build(const std::vector<DyldSharedCache::MappedMachO>& dylibs,
858 const std::vector<DyldSharedCache::MappedMachO>& otherOsDylibsInput,
859 const std::vector<DyldSharedCache::MappedMachO>& osExecutables,
860 std::vector<DyldSharedCache::FileAlias>& aliases) {
861
862 std::vector<LoadedMachO> dylibsToCache;
863 std::vector<LoadedMachO> otherDylibs;
864 std::vector<LoadedMachO> executables;
865
866 for (const DyldSharedCache::MappedMachO& mappedMachO : dylibs) {
867 dyld3::closure::LoadedFileInfo loadedFileInfo;
868 loadedFileInfo.fileContent = mappedMachO.mh;
869 loadedFileInfo.fileContentLen = mappedMachO.length;
870 loadedFileInfo.sliceOffset = mappedMachO.sliceFileOffset;
871 loadedFileInfo.sliceLen = mappedMachO.length;
872 loadedFileInfo.inode = mappedMachO.inode;
873 loadedFileInfo.mtime = mappedMachO.modTime;
874 loadedFileInfo.path = mappedMachO.runtimePath.c_str();
875 dylibsToCache.emplace_back((LoadedMachO){ mappedMachO, loadedFileInfo, nullptr });
876 }
877
878 for (const DyldSharedCache::MappedMachO& mappedMachO : otherOsDylibsInput) {
879 dyld3::closure::LoadedFileInfo loadedFileInfo;
880 loadedFileInfo.fileContent = mappedMachO.mh;
881 loadedFileInfo.fileContentLen = mappedMachO.length;
882 loadedFileInfo.sliceOffset = mappedMachO.sliceFileOffset;
883 loadedFileInfo.sliceLen = mappedMachO.length;
884 loadedFileInfo.inode = mappedMachO.inode;
885 loadedFileInfo.mtime = mappedMachO.modTime;
886 loadedFileInfo.path = mappedMachO.runtimePath.c_str();
887 otherDylibs.emplace_back((LoadedMachO){ mappedMachO, loadedFileInfo, nullptr });
888 }
889
890 for (const DyldSharedCache::MappedMachO& mappedMachO : osExecutables) {
891 dyld3::closure::LoadedFileInfo loadedFileInfo;
892 loadedFileInfo.fileContent = mappedMachO.mh;
893 loadedFileInfo.fileContentLen = mappedMachO.length;
894 loadedFileInfo.sliceOffset = mappedMachO.sliceFileOffset;
895 loadedFileInfo.sliceLen = mappedMachO.length;
896 loadedFileInfo.inode = mappedMachO.inode;
897 loadedFileInfo.mtime = mappedMachO.modTime;
898 loadedFileInfo.path = mappedMachO.runtimePath.c_str();
899 executables.emplace_back((LoadedMachO){ mappedMachO, loadedFileInfo, nullptr });
900 }
901
902 build(dylibsToCache, otherDylibs, executables, aliases);
903 }
904
905 void SharedCacheBuilder::build(const std::vector<LoadedMachO>& dylibs,
906 const std::vector<LoadedMachO>& otherOsDylibsInput,
907 const std::vector<LoadedMachO>& osExecutables,
908 std::vector<DyldSharedCache::FileAlias>& aliases)
909 {
910 // <rdar://problem/21317611> error out instead of crash if cache has no dylibs
911 // FIXME: plist should specify required vs optional dylibs
912 if ( dylibs.size() < 30 ) {
913 _diagnostics.error("missing required minimum set of dylibs");
914 return;
915 }
916
917 _timeRecorder.pushTimedSection();
918
919 // make copy of dylib list and sort
920 makeSortedDylibs(dylibs, _options.dylibOrdering);
921
922 // allocate space used by largest possible cache plus room for LINKEDITS before optimization
923 _allocatedBufferSize = _archLayout->sharedMemorySize * 1.50;
924 if ( vm_allocate(mach_task_self(), &_fullAllocatedBuffer, _allocatedBufferSize, VM_FLAGS_ANYWHERE) != 0 ) {
925 _diagnostics.error("could not allocate buffer");
926 return;
927 }
928
929 _timeRecorder.recordTime("sort dylibs");
930
931 bool impCachesSuccess = false;
932 IMPCaches::HoleMap selectorAddressIntervals;
933 _impCachesBuilder = new IMPCaches::IMPCachesBuilder(_sortedDylibs, _options.objcOptimizations, _diagnostics, _timeRecorder, _fileSystem);
934
935 // Note, macOS allows install names and paths to mismatch. This is currently not supported by
936 // IMP caches as we use install names to look up the set of dylibs.
937 if ( _archLayout->is64
938 && (_options.platform != dyld3::Platform::macOS)
939 && ((_impCachesBuilder->neededClasses.size() > 0) || (_impCachesBuilder->neededMetaclasses.size() > 0))) {
940 // Build the class map across all dylibs (including cross-image superclass references)
941 _impCachesBuilder->buildClassesMap(_diagnostics);
942
943 // Determine which methods will end up in each class's IMP cache
944 impCachesSuccess = _impCachesBuilder->parseDylibs(_diagnostics);
945
946 // Compute perfect hash functions for IMP caches
947 if (impCachesSuccess) _impCachesBuilder->buildPerfectHashes(selectorAddressIntervals, _diagnostics);
948 }
949
950 constexpr bool log = false;
951 if (log) {
952 for (const auto& p : _impCachesBuilder->selectors.map) {
953 printf("0x%06x %s\n", p.second->offset, p.second->name);
954 }
955 }
956
957 _timeRecorder.recordTime("compute IMP caches");
958
959 IMPCaches::SelectorMap emptyMap;
960 IMPCaches::SelectorMap& selectorMap = impCachesSuccess ? _impCachesBuilder->selectors : emptyMap;
961 // assign addresses for each segment of each dylib in new cache
962 parseCoalescableSegments(selectorMap, selectorAddressIntervals);
963 processSelectorStrings(osExecutables, selectorAddressIntervals);
964
965 assignSegmentAddresses();
966 std::vector<const LoadedMachO*> overflowDylibs;
967 while ( cacheOverflowAmount() != 0 ) {
968 // IMP caches: we may need to recompute the selector addresses here to be slightly more compact
969 // if we remove dylibs? This is probably overkill.
970
971 if ( !_options.evictLeafDylibsOnOverflow ) {
972 _diagnostics.error("cache overflow by %lluMB", cacheOverflowAmount() / 1024 / 1024);
973 return;
974 }
975 size_t evictionCount = evictLeafDylibs(cacheOverflowAmount(), overflowDylibs);
976 // re-layout cache
977 for (DylibInfo& dylib : _sortedDylibs)
978 dylib.cacheLocation.clear();
979 _dataRegions.clear();
980 _coalescedText.clear();
981
982 // Re-generate the hole map to remove any cruft that was added when parsing the coalescable text the first time.
983 // Always clear the hole map, even if IMP caches are off, as it is used by the text coalescer
984 selectorAddressIntervals.clear();
985 if (impCachesSuccess) _impCachesBuilder->computeLowBits(selectorAddressIntervals);
986
987 parseCoalescableSegments(selectorMap, selectorAddressIntervals);
988 processSelectorStrings(osExecutables, selectorAddressIntervals);
989 assignSegmentAddresses();
990
991 _diagnostics.verbose("cache overflow, evicted %lu leaf dylibs\n", evictionCount);
992 }
993 markPaddingInaccessible();
994
995 // copy all segments into cache
996
997 unsigned long wastedSelectorsSpace = selectorAddressIntervals.totalHoleSize();
998 if (wastedSelectorsSpace > 0) {
999 _diagnostics.verbose("Selector placement for IMP caches wasted %lu bytes\n", wastedSelectorsSpace);
1000 if (log) {
1001 std::cerr << selectorAddressIntervals << std::endl;
1002 }
1003 }
1004
1005 _timeRecorder.recordTime("layout cache");
1006
1007 writeCacheHeader();
1008 copyRawSegments();
1009 _timeRecorder.recordTime("copy cached dylibs into buffer");
1010
1011 // rebase all dylibs for new location in cache
1012
1013 _aslrTracker.setDataRegion(firstDataRegion()->buffer, dataRegionsTotalSize());
1014 if ( !_options.cacheSupportsASLR )
1015 _aslrTracker.disable();
1016 adjustAllImagesForNewSegmentLocations(_archLayout->sharedMemoryStart, _aslrTracker,
1017 &_lohTracker, &_coalescedText);
1018 if ( _diagnostics.hasError() )
1019 return;
1020
1021 _timeRecorder.recordTime("adjust segments for new split locations");
1022
1023 // build ImageArray for dyld3, which has side effect of binding all cached dylibs
1024 buildImageArray(aliases);
1025 if ( _diagnostics.hasError() )
1026 return;
1027
1028 _timeRecorder.recordTime("bind all images");
1029
1030 // optimize ObjC
1031 DyldSharedCache* dyldCache = (DyldSharedCache*)_readExecuteRegion.buffer;
1032 optimizeObjC(impCachesSuccess, _impCachesBuilder->inlinedSelectors);
1033
1034 delete _impCachesBuilder;
1035 _impCachesBuilder = nullptr;
1036
1037 if ( _diagnostics.hasError() )
1038 return;
1039
1040 _timeRecorder.recordTime("optimize Objective-C");
1041
1042 if ( _options.optimizeStubs ) {
1043 __block std::vector<std::pair<const mach_header*, const char*>> images;
1044 dyldCache->forEachImage(^(const mach_header *mh, const char *installName) {
1045 images.push_back({ mh, installName });
1046 });
1047
1048 int64_t cacheSlide = (long)dyldCache - dyldCache->unslidLoadAddress();
1049 uint64_t cacheUnslideAddr = dyldCache->unslidLoadAddress();
1050 optimizeAwayStubs(images, cacheSlide, cacheUnslideAddr,
1051 dyldCache, _s_neverStubEliminateSymbols);
1052 }
1053
1054
1055 // FIPS seal corecrypto, This must be done after stub elimination (so that __TEXT,__text is not changed after sealing)
1056 fipsSign();
1057
1058 _timeRecorder.recordTime("do stub elimination");
1059
1060 // merge and compact LINKEDIT segments
1061 {
1062 // If we want to remove, not just unmap locals, then set the dylibs themselves to be stripped
1063 DylibStripMode dylibStripMode = DylibStripMode::stripNone;
1064 if ( _options.localSymbolMode == DyldSharedCache::LocalSymbolsMode::strip )
1065 dylibStripMode = CacheBuilder::DylibStripMode::stripLocals;
1066
1067 __block std::vector<std::tuple<const mach_header*, const char*, DylibStripMode>> images;
1068 dyldCache->forEachImage(^(const mach_header *mh, const char *installName) {
1069 images.push_back({ mh, installName, dylibStripMode });
1070 });
1071 optimizeLinkedit(&_localSymbolsRegion, images);
1072 }
1073
1074 // copy ImageArray to end of read-only region
1075 addImageArray();
1076 if ( _diagnostics.hasError() )
1077 return;
1078
1079 _timeRecorder.recordTime("optimize LINKEDITs");
1080
1081 // don't add dyld3 closures to simulator cache or the base system where size is more of an issue
1082 if ( _options.optimizeDyldDlopens ) {
1083 // compute and add dlopen closures for all other dylibs
1084 addOtherImageArray(otherOsDylibsInput, overflowDylibs);
1085 if ( _diagnostics.hasError() )
1086 return;
1087 }
1088 if ( _options.optimizeDyldLaunches ) {
1089 // compute and add launch closures to end of read-only region
1090 addClosures(osExecutables);
1091 if ( _diagnostics.hasError() )
1092 return;
1093 }
1094
1095 // update final readOnly region size
1096 dyld_cache_mapping_info* mappings = (dyld_cache_mapping_info*)(_readExecuteRegion.buffer + dyldCache->header.mappingOffset);
1097 mappings[dyldCache->header.mappingCount - 1].size = _readOnlyRegion.sizeInUse;
1098 dyld_cache_mapping_and_slide_info* slidableMappings = (dyld_cache_mapping_and_slide_info*)(_readExecuteRegion.buffer + dyldCache->header.mappingWithSlideOffset);
1099 slidableMappings[dyldCache->header.mappingCount - 1].size = _readOnlyRegion.sizeInUse;
1100 if ( _localSymbolsRegion.sizeInUse != 0 ) {
1101 dyldCache->header.localSymbolsOffset = _readOnlyRegion.cacheFileOffset + _readOnlyRegion.sizeInUse;
1102 dyldCache->header.localSymbolsSize = _localSymbolsRegion.sizeInUse;
1103 }
1104
1105 // record max slide now that final size is established
1106 if ( _archLayout->sharedRegionsAreDiscontiguous ) {
1107 // special case x86_64 which has three non-contiguous chunks each in their own 1GB regions
1108 uint64_t maxSlide0 = DISCONTIGUOUS_RX_SIZE - _readExecuteRegion.sizeInUse; // TEXT region has 1.5GB region
1109 uint64_t maxSlide1 = DISCONTIGUOUS_RW_SIZE - dataRegionsTotalSize();
1110 uint64_t maxSlide2 = DISCONTIGUOUS_RO_SIZE - _readOnlyRegion.sizeInUse;
1111 dyldCache->header.maxSlide = std::min(std::min(maxSlide0, maxSlide1), maxSlide2);
1112 }
1113 else {
1114 // <rdar://problem/49852839> branch predictor on arm64 currently only looks at low 32-bits, so don't slide cache more than 2GB
1115 if ( (_archLayout->sharedMemorySize == 0x100000000) && (_readExecuteRegion.sizeInUse < 0x80000000) )
1116 dyldCache->header.maxSlide = 0x80000000 - _readExecuteRegion.sizeInUse;
1117 else
1118 dyldCache->header.maxSlide = (_archLayout->sharedMemoryStart + _archLayout->sharedMemorySize) - (_readOnlyRegion.unslidLoadAddress + _readOnlyRegion.sizeInUse);
1119 }
1120
1121 // mark if any input dylibs were built with chained fixups
1122 dyldCache->header.builtFromChainedFixups = _someDylibsUsedChainedFixups;
1123
1124 _timeRecorder.recordTime("build %lu closures", osExecutables.size());
1125 // Emit the CF strings without their ISAs being signed
1126 // This must be after addImageArray() as it depends on hasImageIndex().
1127 // It also has to be before emitting slide info as it adds ASLR entries.
1128 emitContantObjects();
1129
1130 _timeRecorder.recordTime("emit constant objects");
1131
1132 // fill in slide info at start of region[2]
1133 // do this last because it modifies pointers in DATA segments
1134 if ( _options.cacheSupportsASLR ) {
1135 #if SUPPORT_ARCH_arm64e
1136 if ( strcmp(_archLayout->archName, "arm64e") == 0 )
1137 writeSlideInfoV3(_aslrTracker.bitmap(), _aslrTracker.dataPageCount());
1138 else
1139 #endif
1140 if ( _archLayout->is64 )
1141 writeSlideInfoV2<Pointer64<LittleEndian>>(_aslrTracker.bitmap(), _aslrTracker.dataPageCount());
1142 #if SUPPORT_ARCH_arm64_32 || SUPPORT_ARCH_armv7k
1143 else if ( _archLayout->pointerDeltaMask == 0xC0000000 )
1144 writeSlideInfoV4<Pointer32<LittleEndian>>(_aslrTracker.bitmap(), _aslrTracker.dataPageCount());
1145 #endif
1146 else
1147 writeSlideInfoV2<Pointer32<LittleEndian>>(_aslrTracker.bitmap(), _aslrTracker.dataPageCount());
1148 }
1149
1150 _timeRecorder.recordTime("compute slide info");
1151
1152 // last sanity check on size
1153 if ( cacheOverflowAmount() != 0 ) {
1154 _diagnostics.error("cache overflow after optimizations 0x%llX -> 0x%llX", _readExecuteRegion.unslidLoadAddress, _readOnlyRegion.unslidLoadAddress + _readOnlyRegion.sizeInUse);
1155 return;
1156 }
1157
1158 // codesignature is part of file, but is not mapped
1159 codeSign();
1160 if ( _diagnostics.hasError() )
1161 return;
1162
1163 _timeRecorder.recordTime("compute UUID and codesign cache file");
1164
1165 if (_options.verbose) {
1166 _timeRecorder.logTimings();
1167 }
1168
1169 return;
1170 }
1171
1172 const std::set<std::string> SharedCacheBuilder::warnings()
1173 {
1174 return _diagnostics.warnings();
1175 }
1176
1177 const std::set<const dyld3::MachOAnalyzer*> SharedCacheBuilder::evictions()
1178 {
1179 return _evictions;
1180 }
1181
1182 void SharedCacheBuilder::deleteBuffer()
1183 {
1184 // Cache buffer
1185 if ( _allocatedBufferSize != 0 ) {
1186 vm_deallocate(mach_task_self(), _fullAllocatedBuffer, _allocatedBufferSize);
1187 _fullAllocatedBuffer = 0;
1188 _allocatedBufferSize = 0;
1189 }
1190 // Local symbols buffer
1191 if ( _localSymbolsRegion.bufferSize != 0 ) {
1192 vm_deallocate(mach_task_self(), (vm_address_t)_localSymbolsRegion.buffer, _localSymbolsRegion.bufferSize);
1193 _localSymbolsRegion.buffer = 0;
1194 _localSymbolsRegion.bufferSize = 0;
1195 }
1196 // Code signatures
1197 if ( _codeSignatureRegion.bufferSize != 0 ) {
1198 vm_deallocate(mach_task_self(), (vm_address_t)_codeSignatureRegion.buffer, _codeSignatureRegion.bufferSize);
1199 _codeSignatureRegion.buffer = 0;
1200 _codeSignatureRegion.bufferSize = 0;
1201 }
1202 }
1203
1204
1205 void SharedCacheBuilder::makeSortedDylibs(const std::vector<LoadedMachO>& dylibs, const std::unordered_map<std::string, unsigned> sortOrder)
1206 {
1207 for (const LoadedMachO& dylib : dylibs) {
1208 _sortedDylibs.push_back({ &dylib, dylib.mappedFile.runtimePath, {} });
1209 }
1210
1211 std::sort(_sortedDylibs.begin(), _sortedDylibs.end(), [&](const DylibInfo& a, const DylibInfo& b) {
1212 const auto& orderA = sortOrder.find(a.input->mappedFile.runtimePath);
1213 const auto& orderB = sortOrder.find(b.input->mappedFile.runtimePath);
1214 bool foundA = (orderA != sortOrder.end());
1215 bool foundB = (orderB != sortOrder.end());
1216
1217 // Order all __DATA_DIRTY segments specified in the order file first, in
1218 // the order specified in the file, followed by any other __DATA_DIRTY
1219 // segments in lexicographic order.
1220 if ( foundA && foundB )
1221 return orderA->second < orderB->second;
1222 else if ( foundA )
1223 return true;
1224 else if ( foundB )
1225 return false;
1226
1227 // Sort mac before iOSMac
1228 bool isIOSMacA = strncmp(a.input->mappedFile.runtimePath.c_str(), "/System/iOSSupport/", 19) == 0;
1229 bool isIOSMacB = strncmp(b.input->mappedFile.runtimePath.c_str(), "/System/iOSSupport/", 19) == 0;
1230 if (isIOSMacA != isIOSMacB)
1231 return !isIOSMacA;
1232
1233 // Finally sort by path
1234 return a.input->mappedFile.runtimePath < b.input->mappedFile.runtimePath;
1235 });
1236 }
1237
1238 struct DylibAndSize
1239 {
1240 const CacheBuilder::LoadedMachO* input;
1241 const char* installName;
1242 uint64_t size;
1243 };
1244
1245 uint64_t SharedCacheBuilder::cacheOverflowAmount()
1246 {
1247 if ( _archLayout->sharedRegionsAreDiscontiguous ) {
1248 // for macOS x86_64 cache, need to check each region for overflow
1249 if ( _readExecuteRegion.sizeInUse > DISCONTIGUOUS_RX_SIZE )
1250 return (_readExecuteRegion.sizeInUse - DISCONTIGUOUS_RX_SIZE);
1251
1252 uint64_t dataSize = dataRegionsTotalSize();
1253 if ( dataSize > DISCONTIGUOUS_RW_SIZE )
1254 return (dataSize - DISCONTIGUOUS_RW_SIZE);
1255
1256 if ( _readOnlyRegion.sizeInUse > DISCONTIGUOUS_RO_SIZE )
1257 return (_readOnlyRegion.sizeInUse - DISCONTIGUOUS_RO_SIZE);
1258 }
1259 else {
1260 bool alreadyOptimized = (_readOnlyRegion.sizeInUse != _readOnlyRegion.bufferSize);
1261 uint64_t vmSize = _readOnlyRegion.unslidLoadAddress - _readExecuteRegion.unslidLoadAddress;
1262 if ( alreadyOptimized )
1263 vmSize += _readOnlyRegion.sizeInUse;
1264 else if ( _options.localSymbolMode == DyldSharedCache::LocalSymbolsMode::unmap )
1265 vmSize += (_readOnlyRegion.sizeInUse * 37/100); // assume locals removal and LINKEDIT optimzation reduces LINKEDITs %37 of original size
1266 else
1267 vmSize += (_readOnlyRegion.sizeInUse * 80/100); // assume LINKEDIT optimzation reduces LINKEDITs to %80 of original size
1268 if ( vmSize > _archLayout->sharedMemorySize )
1269 return vmSize - _archLayout->sharedMemorySize;
1270 }
1271 // fits in shared region
1272 return 0;
1273 }
1274
1275 size_t SharedCacheBuilder::evictLeafDylibs(uint64_t reductionTarget, std::vector<const LoadedMachO*>& overflowDylibs)
1276 {
1277 // build a reverse map of all dylib dependencies
1278 __block std::map<std::string, std::set<std::string>> references;
1279 std::map<std::string, std::set<std::string>>* referencesPtr = &references;
1280 for (const DylibInfo& dylib : _sortedDylibs) {
1281 // Esnure we have an entry (even if it is empty)
1282 if (references.count(dylib.input->mappedFile.mh->installName()) == 0) {
1283 references[dylib.input->mappedFile.mh->installName()] = std::set<std::string>();
1284 };
1285 dylib.input->mappedFile.mh->forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool &stop) {
1286 references[loadPath].insert(dylib.input->mappedFile.mh->installName());
1287 });
1288 }
1289
1290 // Find the sizes of all the dylibs
1291 std::vector<DylibAndSize> dylibsToSort;
1292 std::vector<DylibAndSize> sortedDylibs;
1293 for (const DylibInfo& dylib : _sortedDylibs) {
1294 const char* installName = dylib.input->mappedFile.mh->installName();
1295 __block uint64_t segsSize = 0;
1296 dylib.input->mappedFile.mh->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& info, bool& stop) {
1297 if ( strcmp(info.segName, "__LINKEDIT") != 0 )
1298 segsSize += info.vmSize;
1299 });
1300 dylibsToSort.push_back({ dylib.input, installName, segsSize });
1301 }
1302
1303 // Build an ordered list of what to remove. At each step we do following
1304 // 1) Find all dylibs that nothing else depends on
1305 // 2a) If any of those dylibs are not in the order select the largest one of them
1306 // 2b) If all the leaf dylibs are in the order file select the last dylib that appears last in the order file
1307 // 3) Remove all entries to the removed file from the reverse dependency map
1308 // 4) Go back to one and repeat until there are no more evictable dylibs
1309 // This results in us always choosing the locally optimal selection, and then taking into account how that impacts
1310 // the dependency graph for subsequent selections
1311
1312 bool candidateFound = true;
1313 while (candidateFound) {
1314 candidateFound = false;
1315 DylibAndSize candidate;
1316 uint64_t candidateOrder = 0;
1317 for(const auto& dylib : dylibsToSort) {
1318 const auto& i = referencesPtr->find(dylib.installName);
1319 assert(i != referencesPtr->end());
1320 if (!i->second.empty()) {
1321 continue;
1322 }
1323 const auto& j = _options.dylibOrdering.find(dylib.input->mappedFile.runtimePath);
1324 uint64_t order = 0;
1325 if (j != _options.dylibOrdering.end()) {
1326 order = j->second;
1327 } else {
1328 // Not in the order file, set order sot it goes to the front of the list
1329 order = UINT64_MAX;
1330 }
1331 if (order > candidateOrder ||
1332 (order == UINT64_MAX && candidate.size < dylib.size)) {
1333 // The new file is either a lower priority in the order file
1334 // or the same priority as the candidate but larger
1335 candidate = dylib;
1336 candidateOrder = order;
1337 candidateFound = true;
1338 }
1339 }
1340 if (candidateFound) {
1341 sortedDylibs.push_back(candidate);
1342 referencesPtr->erase(candidate.installName);
1343 for (auto& dependent : references) {
1344 (void)dependent.second.erase(candidate.installName);
1345 }
1346 auto j = std::find_if(dylibsToSort.begin(), dylibsToSort.end(), [&candidate](const DylibAndSize& dylib) {
1347 return (strcmp(candidate.installName, dylib.installName) == 0);
1348 });
1349 if (j != dylibsToSort.end()) {
1350 dylibsToSort.erase(j);
1351 }
1352 }
1353 }
1354
1355 // build set of dylibs that if removed will allow cache to build
1356 for (DylibAndSize& dylib : sortedDylibs) {
1357 if ( _options.verbose )
1358 _diagnostics.warning("to prevent cache overflow, not caching %s", dylib.installName);
1359 _evictions.insert(dylib.input->mappedFile.mh);
1360 // Track the evicted dylibs so we can try build "other" dlopen closures for them.
1361 overflowDylibs.push_back(dylib.input);
1362 if ( dylib.size > reductionTarget )
1363 break;
1364 reductionTarget -= dylib.size;
1365 }
1366
1367 // prune _sortedDylibs
1368 _sortedDylibs.erase(std::remove_if(_sortedDylibs.begin(), _sortedDylibs.end(), [&](const DylibInfo& dylib) {
1369 return (_evictions.count(dylib.input->mappedFile.mh) != 0);
1370 }),_sortedDylibs.end());
1371
1372 return _evictions.size();
1373 }
1374
1375
1376 void SharedCacheBuilder::writeCacheHeader()
1377 {
1378 // "dyld_v1" + spaces + archName(), with enough spaces to pad to 15 bytes
1379 std::string magic = "dyld_v1";
1380 magic.append(15 - magic.length() - strlen(_options.archs->name()), ' ');
1381 magic.append(_options.archs->name());
1382 assert(magic.length() == 15);
1383
1384 // 1 __TEXT segment, n __DATA segments, and 1 __LINKEDIT segment
1385 const uint32_t mappingCount = 2 + (uint32_t)_dataRegions.size();
1386 assert(mappingCount <= DyldSharedCache::MaxMappings);
1387
1388 // fill in header
1389 dyld_cache_header* dyldCacheHeader = (dyld_cache_header*)_readExecuteRegion.buffer;
1390 memcpy(dyldCacheHeader->magic, magic.c_str(), 16);
1391 dyldCacheHeader->mappingOffset = sizeof(dyld_cache_header);
1392 dyldCacheHeader->mappingCount = mappingCount;
1393 dyldCacheHeader->mappingWithSlideOffset = (uint32_t)(dyldCacheHeader->mappingOffset + mappingCount*sizeof(dyld_cache_mapping_and_slide_info));
1394 dyldCacheHeader->mappingWithSlideCount = mappingCount;
1395 dyldCacheHeader->imagesOffset = (uint32_t)(dyldCacheHeader->mappingWithSlideOffset + mappingCount*sizeof(dyld_cache_mapping_and_slide_info));
1396 dyldCacheHeader->imagesCount = (uint32_t)_sortedDylibs.size() + _aliasCount;
1397 dyldCacheHeader->dyldBaseAddress = 0;
1398 dyldCacheHeader->codeSignatureOffset = 0;
1399 dyldCacheHeader->codeSignatureSize = 0;
1400 dyldCacheHeader->slideInfoOffsetUnused = 0;
1401 dyldCacheHeader->slideInfoSizeUnused = 0;
1402 dyldCacheHeader->localSymbolsOffset = 0;
1403 dyldCacheHeader->localSymbolsSize = 0;
1404 dyldCacheHeader->cacheType = _options.optimizeStubs ? kDyldSharedCacheTypeProduction : kDyldSharedCacheTypeDevelopment;
1405 dyldCacheHeader->accelerateInfoAddr = 0;
1406 dyldCacheHeader->accelerateInfoSize = 0;
1407 bzero(dyldCacheHeader->uuid, 16);// overwritten later by recomputeCacheUUID()
1408 dyldCacheHeader->branchPoolsOffset = 0;
1409 dyldCacheHeader->branchPoolsCount = 0;
1410 dyldCacheHeader->imagesTextOffset = dyldCacheHeader->imagesOffset + sizeof(dyld_cache_image_info)*dyldCacheHeader->imagesCount;
1411 dyldCacheHeader->imagesTextCount = _sortedDylibs.size();
1412 dyldCacheHeader->patchInfoAddr = 0;
1413 dyldCacheHeader->patchInfoSize = 0;
1414 dyldCacheHeader->otherImageGroupAddrUnused = 0;
1415 dyldCacheHeader->otherImageGroupSizeUnused = 0;
1416 dyldCacheHeader->progClosuresAddr = 0;
1417 dyldCacheHeader->progClosuresSize = 0;
1418 dyldCacheHeader->progClosuresTrieAddr = 0;
1419 dyldCacheHeader->progClosuresTrieSize = 0;
1420 dyldCacheHeader->platform = (uint8_t)_options.platform;
1421 dyldCacheHeader->formatVersion = dyld3::closure::kFormatVersion;
1422 dyldCacheHeader->dylibsExpectedOnDisk = !_options.dylibsRemovedDuringMastering;
1423 dyldCacheHeader->simulator = _options.forSimulator;
1424 dyldCacheHeader->locallyBuiltCache = _options.isLocallyBuiltCache;
1425 dyldCacheHeader->builtFromChainedFixups= false;
1426 dyldCacheHeader->formatVersion = dyld3::closure::kFormatVersion;
1427 dyldCacheHeader->sharedRegionStart = _archLayout->sharedMemoryStart;
1428 dyldCacheHeader->sharedRegionSize = _archLayout->sharedMemorySize;
1429
1430 // fill in mappings
1431 dyld_cache_mapping_info* mappings = (dyld_cache_mapping_info*)(_readExecuteRegion.buffer + dyldCacheHeader->mappingOffset);
1432 assert(_readExecuteRegion.cacheFileOffset == 0);
1433 mappings[0].address = _readExecuteRegion.unslidLoadAddress;
1434 mappings[0].fileOffset = _readExecuteRegion.cacheFileOffset;
1435 mappings[0].size = _readExecuteRegion.sizeInUse;
1436 mappings[0].maxProt = VM_PROT_READ | VM_PROT_EXECUTE;
1437 mappings[0].initProt = VM_PROT_READ | VM_PROT_EXECUTE;
1438 for (uint32_t i = 0; i != _dataRegions.size(); ++i) {
1439 if ( i == 0 ) {
1440 assert(_dataRegions[i].cacheFileOffset == _readExecuteRegion.sizeInUse);
1441 }
1442
1443 assert(_dataRegions[i].initProt != 0);
1444 assert(_dataRegions[i].maxProt != 0);
1445
1446 mappings[i + 1].address = _dataRegions[i].unslidLoadAddress;
1447 mappings[i + 1].fileOffset = _dataRegions[i].cacheFileOffset;
1448 mappings[i + 1].size = _dataRegions[i].sizeInUse;
1449 mappings[i + 1].maxProt = _dataRegions[i].maxProt;
1450 mappings[i + 1].initProt = _dataRegions[i].initProt;
1451 }
1452 assert(_readOnlyRegion.cacheFileOffset == (_dataRegions.back().cacheFileOffset + _dataRegions.back().sizeInUse));
1453 mappings[mappingCount - 1].address = _readOnlyRegion.unslidLoadAddress;
1454 mappings[mappingCount - 1].fileOffset = _readOnlyRegion.cacheFileOffset;
1455 mappings[mappingCount - 1].size = _readOnlyRegion.sizeInUse;
1456 mappings[mappingCount - 1].maxProt = VM_PROT_READ;
1457 mappings[mappingCount - 1].initProt = VM_PROT_READ;
1458
1459 // Add in the new mappings with also have slide info
1460 dyld_cache_mapping_and_slide_info* slidableMappings = (dyld_cache_mapping_and_slide_info*)(_readExecuteRegion.buffer + dyldCacheHeader->mappingWithSlideOffset);
1461 slidableMappings[0].address = _readExecuteRegion.unslidLoadAddress;
1462 slidableMappings[0].fileOffset = _readExecuteRegion.cacheFileOffset;
1463 slidableMappings[0].size = _readExecuteRegion.sizeInUse;
1464 slidableMappings[0].maxProt = VM_PROT_READ | VM_PROT_EXECUTE;
1465 slidableMappings[0].initProt = VM_PROT_READ | VM_PROT_EXECUTE;
1466 slidableMappings[0].slideInfoFileOffset = 0;
1467 slidableMappings[0].slideInfoFileSize = 0;
1468 slidableMappings[0].flags = 0;
1469 for (uint32_t i = 0; i != _dataRegions.size(); ++i) {
1470 // Work out which flags this mapping has
1471 uint64_t flags = 0;
1472 if ( startsWith(_dataRegions[i].name, "__AUTH") )
1473 flags |= DYLD_CACHE_MAPPING_AUTH_DATA;
1474 if ( (_dataRegions[i].name == "__AUTH_DIRTY") || (_dataRegions[i].name == "__DATA_DIRTY") ) {
1475 flags |= DYLD_CACHE_MAPPING_DIRTY_DATA;
1476 } else if ( (_dataRegions[i].name == "__AUTH_CONST") || (_dataRegions[i].name == "__DATA_CONST") ) {
1477 flags |= DYLD_CACHE_MAPPING_CONST_DATA;
1478 }
1479
1480 assert(_dataRegions[i].initProt != 0);
1481 assert(_dataRegions[i].maxProt != 0);
1482
1483 slidableMappings[i + 1].address = _dataRegions[i].unslidLoadAddress;
1484 slidableMappings[i + 1].fileOffset = _dataRegions[i].cacheFileOffset;
1485 slidableMappings[i + 1].size = _dataRegions[i].sizeInUse;
1486 slidableMappings[i + 1].maxProt = _dataRegions[i].maxProt;
1487 slidableMappings[i + 1].initProt = _dataRegions[i].initProt;
1488 slidableMappings[i + 1].slideInfoFileOffset = _dataRegions[i].slideInfoFileOffset;
1489 slidableMappings[i + 1].slideInfoFileSize = _dataRegions[i].slideInfoFileSize;
1490 slidableMappings[i + 1].flags = flags;
1491 }
1492 slidableMappings[mappingCount - 1].address = _readOnlyRegion.unslidLoadAddress;
1493 slidableMappings[mappingCount - 1].fileOffset = _readOnlyRegion.cacheFileOffset;
1494 slidableMappings[mappingCount - 1].size = _readOnlyRegion.sizeInUse;
1495 slidableMappings[mappingCount - 1].maxProt = VM_PROT_READ;
1496 slidableMappings[mappingCount - 1].initProt = VM_PROT_READ;
1497 slidableMappings[mappingCount - 1].slideInfoFileOffset = 0;
1498 slidableMappings[mappingCount - 1].slideInfoFileSize = 0;
1499 slidableMappings[mappingCount - 1].flags = 0;
1500
1501 // fill in image table
1502 dyld_cache_image_info* images = (dyld_cache_image_info*)(_readExecuteRegion.buffer + dyldCacheHeader->imagesOffset);
1503 for (const DylibInfo& dylib : _sortedDylibs) {
1504 const char* installName = dylib.input->mappedFile.mh->installName();
1505 images->address = dylib.cacheLocation[0].dstCacheUnslidAddress;
1506 if ( _options.dylibsRemovedDuringMastering ) {
1507 images->modTime = 0;
1508 images->inode = pathHash(installName);
1509 }
1510 else {
1511 images->modTime = dylib.input->mappedFile.modTime;
1512 images->inode = dylib.input->mappedFile.inode;
1513 }
1514 uint32_t installNameOffsetInTEXT = (uint32_t)(installName - (char*)dylib.input->mappedFile.mh);
1515 images->pathFileOffset = (uint32_t)dylib.cacheLocation[0].dstCacheFileOffset + installNameOffsetInTEXT;
1516 ++images;
1517 }
1518 // append aliases image records and strings
1519 /*
1520 for (auto &dylib : _dylibs) {
1521 if (!dylib->installNameAliases.empty()) {
1522 for (const std::string& alias : dylib->installNameAliases) {
1523 images->set_address(_segmentMap[dylib][0].address);
1524 if (_manifest.platform() == "osx") {
1525 images->modTime = dylib->lastModTime;
1526 images->inode = dylib->inode;
1527 }
1528 else {
1529 images->modTime = 0;
1530 images->inode = pathHash(alias.c_str());
1531 }
1532 images->pathFileOffset = offset;
1533 //fprintf(stderr, "adding alias %s for %s\n", alias.c_str(), dylib->installName.c_str());
1534 ::strcpy((char*)&_buffer[offset], alias.c_str());
1535 offset += alias.size() + 1;
1536 ++images;
1537 }
1538 }
1539 }
1540 */
1541 // calculate start of text image array and trailing string pool
1542 dyld_cache_image_text_info* textImages = (dyld_cache_image_text_info*)(_readExecuteRegion.buffer + dyldCacheHeader->imagesTextOffset);
1543 uint32_t stringOffset = (uint32_t)(dyldCacheHeader->imagesTextOffset + sizeof(dyld_cache_image_text_info) * _sortedDylibs.size());
1544
1545 // write text image array and image names pool at same time
1546 for (const DylibInfo& dylib : _sortedDylibs) {
1547 dylib.input->mappedFile.mh->getUuid(textImages->uuid);
1548 textImages->loadAddress = dylib.cacheLocation[0].dstCacheUnslidAddress;
1549 textImages->textSegmentSize = (uint32_t)dylib.cacheLocation[0].dstCacheSegmentSize;
1550 textImages->pathOffset = stringOffset;
1551 const char* installName = dylib.input->mappedFile.mh->installName();
1552 ::strcpy((char*)_readExecuteRegion.buffer + stringOffset, installName);
1553 stringOffset += (uint32_t)strlen(installName)+1;
1554 ++textImages;
1555 }
1556
1557 // make sure header did not overflow into first mapped image
1558 const dyld_cache_image_info* firstImage = (dyld_cache_image_info*)(_readExecuteRegion.buffer + dyldCacheHeader->imagesOffset);
1559 assert(stringOffset <= (firstImage->address - mappings[0].address));
1560 }
1561
1562 void SharedCacheBuilder::processSelectorStrings(const std::vector<LoadedMachO>& executables, IMPCaches::HoleMap& selectorsHoleMap) {
1563 const bool log = false;
1564
1565 // We only do this optimisation to reduce the size of the shared cache executable closures
1566 // Skip this is those closures are not being built
1567 if ( !_options.optimizeDyldDlopens || !_options.optimizeDyldLaunches )
1568 return;
1569
1570 _selectorStringsFromExecutables = 0;
1571 uint64_t totalBytesPulledIn = 0;
1572
1573 // Don't do this optimisation on watchOS where the shared cache is too small
1574 if (_options.platform == dyld3::Platform::watchOS)
1575 return;
1576
1577 // Get the method name coalesced section as that is where we need to put these strings
1578 CacheBuilder::CacheCoalescedText::StringSection& cacheStringSection = _coalescedText.getSectionData("__objc_methname");
1579 for (const LoadedMachO& executable : executables) {
1580 const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*)executable.loadedFileInfo.fileContent;
1581
1582 uint64_t sizeBeforeProcessing = cacheStringSection.bufferSize;
1583
1584 ma->forEachObjCMethodName(^(const char* methodName) {
1585 std::string_view str = methodName;
1586 if (cacheStringSection.stringsToOffsets.find(str) == cacheStringSection.stringsToOffsets.end()) {
1587 int offset = selectorsHoleMap.addStringOfSize((unsigned)str.size() + 1);
1588 cacheStringSection.stringsToOffsets[str] = offset;
1589
1590 // If we inserted the string past the end then we need to include it in the total
1591 int possibleNewEnd = offset + (int)str.size() + 1;
1592 if (cacheStringSection.bufferSize < (uint32_t)possibleNewEnd) {
1593 cacheStringSection.bufferSize = (uint32_t)possibleNewEnd;
1594 }
1595 // if (log) printf("Selector: %s -> %s\n", ma->installName(), methodName);
1596 ++_selectorStringsFromExecutables;
1597 }
1598 });
1599
1600 uint64_t sizeAfterProcessing = cacheStringSection.bufferSize;
1601 totalBytesPulledIn += (sizeAfterProcessing - sizeBeforeProcessing);
1602 if ( log && (sizeBeforeProcessing != sizeAfterProcessing) ) {
1603 printf("Pulled in % 6lld bytes of selectors from %s\n",
1604 sizeAfterProcessing - sizeBeforeProcessing, executable.loadedFileInfo.path);
1605 }
1606 }
1607
1608 _diagnostics.verbose("Pulled in %lld selector strings (%lld bytes) from executables\n",
1609 _selectorStringsFromExecutables, totalBytesPulledIn);
1610 }
1611
1612 void SharedCacheBuilder::parseCoalescableSegments(IMPCaches::SelectorMap& selectors, IMPCaches::HoleMap& selectorsHoleMap) {
1613 const bool log = false;
1614
1615 for (DylibInfo& dylib : _sortedDylibs)
1616 _coalescedText.parseCoalescableText(dylib.input->mappedFile.mh, dylib.textCoalescer, selectors, selectorsHoleMap);
1617
1618 if (log) {
1619 for (const char* section : CacheCoalescedText::SupportedSections) {
1620 CacheCoalescedText::StringSection& sectionData = _coalescedText.getSectionData(section);
1621 printf("Coalesced %s from % 10lld -> % 10d, saving % 10lld bytes\n", section,
1622 sectionData.bufferSize + sectionData.savedSpace, sectionData.bufferSize, sectionData.savedSpace);
1623 }
1624 }
1625
1626 // arm64e needs to convert CF constants to tagged pointers
1627 if ( !strcmp(_archLayout->archName, "arm64e") ) {
1628 // Find the dylib which exports the CFString ISA. It's likely CoreFoundation but it could move
1629 CacheCoalescedText::CFSection& cfStrings = _coalescedText.cfStrings;
1630 for (DylibInfo& dylib : _sortedDylibs) {
1631 const dyld3::MachOAnalyzer* ma = dylib.input->mappedFile.mh;
1632 dyld3::MachOAnalyzer::FoundSymbol foundInfo;
1633 bool foundISASymbol = ma->findExportedSymbol(_diagnostics, cfStrings.isaClassName, false, foundInfo, nullptr);
1634 if ( foundISASymbol ) {
1635 // This dylib exports the ISA, so everyone else should look here for the ISA too.
1636 if ( cfStrings.isaInstallName != nullptr ) {
1637 // Found a duplicate. We can't do anything here
1638 _diagnostics.verbose("Could not optimize CFString's due to duplicate ISA symbols");
1639 cfStrings.isaInstallName = nullptr;
1640 break;
1641 } else {
1642 cfStrings.isaInstallName = ma->installName();
1643 cfStrings.isaVMOffset = foundInfo.value;
1644 }
1645 }
1646 }
1647 if ( cfStrings.isaInstallName != nullptr ) {
1648 for (DylibInfo& dylib : _sortedDylibs) {
1649 _coalescedText.parseCFConstants(dylib.input->mappedFile.mh, dylib.textCoalescer);
1650 }
1651 }
1652 }
1653 }
1654
1655 // This is the new method which will put all __DATA* mappings in to a their own mappings
1656 void SharedCacheBuilder::assignMultipleDataSegmentAddresses(uint64_t& addr, uint32_t totalProtocolDefCount) {
1657 uint64_t nextRegionFileOffset = _readExecuteRegion.sizeInUse;
1658
1659 const size_t dylibCount = _sortedDylibs.size();
1660 BLOCK_ACCCESSIBLE_ARRAY(uint32_t, dirtyDataSortIndexes, dylibCount);
1661 for (size_t i=0; i < dylibCount; ++i)
1662 dirtyDataSortIndexes[i] = (uint32_t)i;
1663 std::sort(&dirtyDataSortIndexes[0], &dirtyDataSortIndexes[dylibCount], [&](const uint32_t& a, const uint32_t& b) {
1664 const auto& orderA = _options.dirtyDataSegmentOrdering.find(_sortedDylibs[a].input->mappedFile.runtimePath);
1665 const auto& orderB = _options.dirtyDataSegmentOrdering.find(_sortedDylibs[b].input->mappedFile.runtimePath);
1666 bool foundA = (orderA != _options.dirtyDataSegmentOrdering.end());
1667 bool foundB = (orderB != _options.dirtyDataSegmentOrdering.end());
1668
1669 // Order all __DATA_DIRTY segments specified in the order file first, in the order specified in the file,
1670 // followed by any other __DATA_DIRTY segments in lexicographic order.
1671 if ( foundA && foundB )
1672 return orderA->second < orderB->second;
1673 else if ( foundA )
1674 return true;
1675 else if ( foundB )
1676 return false;
1677 else
1678 return _sortedDylibs[a].input->mappedFile.runtimePath < _sortedDylibs[b].input->mappedFile.runtimePath;
1679 });
1680
1681 bool supportsAuthFixups = false;
1682
1683 // This tracks which segments contain authenticated data, even if their name isn't __AUTH*
1684 std::set<uint32_t> authenticatedSegments[dylibCount];
1685 if ( strcmp(_archLayout->archName, "arm64e") == 0 ) {
1686 supportsAuthFixups = true;
1687
1688 for (DylibInfo& dylib : _sortedDylibs) {
1689 uint64_t dylibIndex = &dylib - _sortedDylibs.data();
1690 __block std::set<uint32_t>& authSegmentIndices = authenticatedSegments[dylibIndex];
1691
1692 // Put all __DATA_DIRTY segments in the __AUTH region first, then we don't need to walk their chains
1693 dylib.input->mappedFile.mh->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& segInfo, bool& stop) {
1694 if ( strcmp(segInfo.segName, "__DATA_DIRTY") == 0 ) {
1695 authSegmentIndices.insert(segInfo.segIndex);
1696 stop = true;
1697 }
1698 });
1699 dylib.input->mappedFile.mh->withChainStarts(_diagnostics, 0,
1700 ^(const dyld_chained_starts_in_image *starts) {
1701 dylib.input->mappedFile.mh->forEachFixupChainSegment(_diagnostics, starts,
1702 ^(const dyld_chained_starts_in_segment* segmentInfo, uint32_t segIndex, bool& stopSegment) {
1703 // Skip walking segments we already know are __AUTH, ie, __DATA_DIRTY
1704 if ( authSegmentIndices.count(segIndex) )
1705 return;
1706
1707 dylib.input->mappedFile.mh->forEachFixupInSegmentChains(_diagnostics, segmentInfo, false,
1708 ^(dyld3::MachOLoaded::ChainedFixupPointerOnDisk* fixupLoc, const dyld_chained_starts_in_segment* segInfo, bool& stopChain) {
1709 uint16_t chainedFixupsFormat = segInfo->pointer_format;
1710 assert( (chainedFixupsFormat == DYLD_CHAINED_PTR_ARM64E) || (chainedFixupsFormat == DYLD_CHAINED_PTR_ARM64E_USERLAND) || (chainedFixupsFormat == DYLD_CHAINED_PTR_ARM64E_USERLAND24) );
1711
1712 if ( fixupLoc->arm64e.authRebase.auth ) {
1713 authSegmentIndices.insert(segIndex);
1714 stopChain = true;
1715 return;
1716 }
1717 });
1718 });
1719 });
1720 }
1721 }
1722
1723 // Categorize each segment in each binary
1724 enum class SegmentType : uint8_t {
1725 skip, // used for non-data segments we should ignore here
1726 data,
1727 dataDirty,
1728 dataConst,
1729 auth,
1730 authDirty,
1731 authConst,
1732 };
1733
1734 BLOCK_ACCCESSIBLE_ARRAY(uint64_t, textSegVmAddrs, dylibCount);
1735 BLOCK_ACCCESSIBLE_ARRAY(std::vector<SegmentType>, segmentTypes, dylibCount);
1736
1737 // Just in case __AUTH is used in a non-arm64e binary, we can force it to use data enums
1738 SegmentType authSegment = supportsAuthFixups ? SegmentType::auth : SegmentType::data;
1739 SegmentType authConstSegment = supportsAuthFixups ? SegmentType::authConst : SegmentType::dataConst;
1740
1741 for (const DylibInfo& dylib : _sortedDylibs) {
1742 uint64_t dylibIndex = &dylib - _sortedDylibs.data();
1743 __block std::set<uint32_t>& authSegmentIndices = authenticatedSegments[dylibIndex];
1744 __block std::vector<SegmentType>& dylibSegmentTypes = segmentTypes[dylibIndex];
1745 uint64_t &textSegVmAddr = textSegVmAddrs[dylibIndex];
1746 dylib.input->mappedFile.mh->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& segInfo, bool& stop) {
1747 if ( strcmp(segInfo.segName, "__TEXT") == 0 ) {
1748 textSegVmAddr = segInfo.vmAddr;
1749 }
1750
1751 // Skip non-DATA segments
1752 if ( segInfo.protections != (VM_PROT_READ | VM_PROT_WRITE) ) {
1753 dylibSegmentTypes.push_back(SegmentType::skip);
1754 return;
1755 }
1756
1757 // If we don't have split seg v2, then all remaining segments must look like __DATA so that they
1758 // stay contiguous
1759 if (!dylib.input->mappedFile.mh->isSplitSegV2()) {
1760 dylibSegmentTypes.push_back(SegmentType::data);
1761 return;
1762 }
1763
1764 __block bool supportsDataConst = true;
1765 if ( dylib.input->mappedFile.mh->isSwiftLibrary() ) {
1766 uint64_t objcConstSize = 0;
1767 bool containsObjCSection = dylib.input->mappedFile.mh->findSectionContent(segInfo.segName, "__objc_const", objcConstSize);
1768
1769 // <rdar://problem/66284631> Don't put __objc_const read-only memory as Swift has method lists we can't see
1770 if ( containsObjCSection )
1771 supportsDataConst = false;
1772 } else if ( !strcmp(dylib.input->mappedFile.mh->installName(), "/System/Library/Frameworks/Foundation.framework/Foundation") ||
1773 !strcmp(dylib.input->mappedFile.mh->installName(), "/System/Library/Frameworks/Foundation.framework/Versions/C/Foundation") ) {
1774 // <rdar://problem/69813664> _NSTheOneTruePredicate is incompatible with __DATA_CONST
1775 supportsDataConst = false;
1776 } else if ( !strcmp(dylib.input->mappedFile.mh->installName(), "/usr/lib/system/libdispatch.dylib") ) {
1777 // rdar://72361509 (Speechrecognitiond crashing on AzulE18E123)
1778 supportsDataConst = false;
1779 } else if ( !strcmp(dylib.input->mappedFile.mh->installName(), "/System/Library/Frameworks/CoreFoundation.framework/CoreFoundation") ||
1780 !strcmp(dylib.input->mappedFile.mh->installName(), "/System/Library/Frameworks/CoreFoundation.framework/Versions/A/CoreFoundation") ) {
1781 // rdar://74112547 CF writes to kCFNull constant object
1782 supportsDataConst = false;
1783 }
1784
1785 // Don't use data const for dylibs containing resolver functions. This will be fixed in ld64 by moving their pointer atoms to __DATA
1786 if ( supportsDataConst && endsWith(segInfo.segName, "_CONST") ) {
1787 dylib.input->mappedFile.mh->forEachExportedSymbol(_diagnostics,
1788 ^(const char *symbolName, uint64_t imageOffset, uint64_t flags, uint64_t other, const char *importName, bool &stop) {
1789 if ( (flags & EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER ) != 0 ) {
1790 _diagnostics.verbose("%s: preventing use of __DATA_CONST due to resolvers\n", dylib.dylibID.c_str());
1791 supportsDataConst = false;
1792 stop = true;
1793 }
1794 });
1795 }
1796
1797 // If we are still allowed to use __DATA_CONST, then make sure that we are not using pointer based method lists. These may not be written in libobjc due
1798 // to uniquing or sorting (as those are done in the builder), but clients can still call setIMP to mutate them.
1799 if ( supportsDataConst && endsWith(segInfo.segName, "_CONST") ) {
1800 uint64_t segStartVMAddr = segInfo.vmAddr;
1801 uint64_t segEndVMAddr = segInfo.vmAddr + segInfo.vmSize;
1802
1803 auto vmAddrConverter = dylib.input->mappedFile.mh->makeVMAddrConverter(false);
1804 const uint32_t pointerSize = dylib.input->mappedFile.mh->pointerSize();
1805
1806 __block bool foundPointerBasedMethodList = false;
1807 auto visitMethodList = ^(uint64_t methodListVMAddr) {
1808 if ( foundPointerBasedMethodList )
1809 return;
1810 if ( methodListVMAddr == 0 )
1811 return;
1812 // Ignore method lists in other segments
1813 if ( (methodListVMAddr < segStartVMAddr) || (methodListVMAddr >= segEndVMAddr) )
1814 return;
1815 auto visitMethod = ^(uint64_t methodVMAddr, const dyld3::MachOAnalyzer::ObjCMethod& method) { };
1816 bool isRelativeMethodList = false;
1817 dylib.input->mappedFile.mh->forEachObjCMethod(methodListVMAddr, vmAddrConverter, visitMethod, &isRelativeMethodList);
1818 if ( !isRelativeMethodList )
1819 foundPointerBasedMethodList = true;
1820 };
1821
1822 auto visitClass = ^(Diagnostics& diag, uint64_t classVMAddr,
1823 uint64_t classSuperclassVMAddr, uint64_t classDataVMAddr,
1824 const dyld3::MachOAnalyzer::ObjCClassInfo& objcClass, bool isMetaClass) {
1825 visitMethodList(objcClass.baseMethodsVMAddr(pointerSize));
1826 };
1827
1828 auto visitCategory = ^(Diagnostics& diag, uint64_t categoryVMAddr,
1829 const dyld3::MachOAnalyzer::ObjCCategory& objcCategory) {
1830 visitMethodList(objcCategory.instanceMethodsVMAddr);
1831 visitMethodList(objcCategory.classMethodsVMAddr);
1832 };
1833
1834 // Walk the class list
1835 Diagnostics classDiag;
1836 dylib.input->mappedFile.mh->forEachObjCClass(classDiag, vmAddrConverter, visitClass);
1837
1838 // Walk the category list
1839 Diagnostics categoryDiag;
1840 dylib.input->mappedFile.mh->forEachObjCCategory(categoryDiag, vmAddrConverter, visitCategory);
1841
1842 // Note we don't walk protocols as they don't have an IMP to set
1843
1844 if ( foundPointerBasedMethodList ) {
1845 _diagnostics.verbose("%s: preventing use of read-only %s due to pointer based method list\n", dylib.dylibID.c_str(), segInfo.segName);
1846 supportsDataConst = false;
1847 }
1848 }
1849
1850 // __AUTH_CONST
1851 if ( strcmp(segInfo.segName, "__AUTH_CONST") == 0 ) {
1852 dylibSegmentTypes.push_back(supportsDataConst ? authConstSegment : authSegment);
1853 return;
1854 }
1855
1856 // __DATA_CONST
1857 if ( (strcmp(segInfo.segName, "__DATA_CONST") == 0) || (strcmp(segInfo.segName, "__OBJC_CONST") == 0) ) {
1858 if ( authSegmentIndices.count(segInfo.segIndex) ) {
1859 // _diagnostics.verbose("%s: treating authenticated %s as __AUTH_CONST\n", dylib.dylibID.c_str(), segInfo.segName);
1860 dylibSegmentTypes.push_back(supportsDataConst ? SegmentType::authConst : SegmentType::auth);
1861 } else {
1862 dylibSegmentTypes.push_back(supportsDataConst ? SegmentType::dataConst : SegmentType::data);
1863 }
1864 return;
1865 }
1866
1867 // __DATA_DIRTY
1868 if ( strcmp(segInfo.segName, "__DATA_DIRTY") == 0 ) {
1869 if ( authSegmentIndices.count(segInfo.segIndex) ) {
1870 dylibSegmentTypes.push_back(SegmentType::authDirty);
1871 } else {
1872 dylibSegmentTypes.push_back(SegmentType::dataDirty);
1873 }
1874 return;
1875 }
1876
1877 // __AUTH
1878 if ( strcmp(segInfo.segName, "__AUTH") == 0 ) {
1879 dylibSegmentTypes.push_back(authSegment);
1880 return;
1881 }
1882
1883 // DATA
1884 if ( authSegmentIndices.count(segInfo.segIndex) ) {
1885 // _diagnostics.verbose("%s: treating authenticated %s as __AUTH\n", dylib.dylibID.c_str(), segInfo.segName);
1886 dylibSegmentTypes.push_back(SegmentType::auth);
1887 } else {
1888 dylibSegmentTypes.push_back(SegmentType::data);
1889 }
1890 });
1891 }
1892
1893 auto processDylibSegments = ^(SegmentType onlyType, Region& region) {
1894 for (size_t unsortedDylibIndex = 0; unsortedDylibIndex != dylibCount; ++unsortedDylibIndex) {
1895 size_t dylibIndex = unsortedDylibIndex;
1896 if ( (onlyType == SegmentType::dataDirty) || (onlyType == SegmentType::authDirty) )
1897 dylibIndex = dirtyDataSortIndexes[dylibIndex];
1898
1899 DylibInfo& dylib = _sortedDylibs[dylibIndex];
1900 const std::vector<SegmentType>& dylibSegmentTypes = segmentTypes[dylibIndex];
1901 const uint64_t textSegVmAddr = textSegVmAddrs[dylibIndex];
1902
1903 bool forcePageAlignedData = false;
1904 if ( (_options.platform == dyld3::Platform::macOS) && (onlyType == SegmentType::data) ) {
1905 forcePageAlignedData = dylib.input->mappedFile.mh->hasUnalignedPointerFixups();
1906 //if ( forcePageAlignedData )
1907 // warning("unaligned pointer in %s\n", dylib.input->mappedFile.runtimePath.c_str());
1908 }
1909
1910 dylib.input->mappedFile.mh->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& segInfo, bool& stop) {
1911 if ( dylibSegmentTypes[segInfo.segIndex] != onlyType )
1912 return;
1913
1914 // We may have coalesced the sections at the end of this segment. In that case, shrink the segment to remove them.
1915 __block size_t sizeOfSections = 0;
1916 __block bool foundCoalescedSection = false;
1917 dylib.input->mappedFile.mh->forEachSection(^(const dyld3::MachOAnalyzer::SectionInfo &sectInfo, bool malformedSectionRange, bool &stopSection) {
1918 if (strcmp(sectInfo.segInfo.segName, segInfo.segName) != 0)
1919 return;
1920 if ( dylib.textCoalescer.sectionWasCoalesced(segInfo.segName, sectInfo.sectName)) {
1921 foundCoalescedSection = true;
1922 } else {
1923 sizeOfSections = sectInfo.sectAddr + sectInfo.sectSize - segInfo.vmAddr;
1924 }
1925 });
1926 if (!foundCoalescedSection)
1927 sizeOfSections = segInfo.sizeOfSections;
1928
1929 if ( !forcePageAlignedData ) {
1930 // Pack __DATA segments
1931 addr = align(addr, segInfo.p2align);
1932 }
1933 else {
1934 // Keep __DATA segments 4K or more aligned
1935 addr = align(addr, std::max((int)segInfo.p2align, (int)12));
1936 }
1937
1938 size_t copySize = std::min((size_t)segInfo.fileSize, (size_t)sizeOfSections);
1939 uint64_t offsetInRegion = addr - region.unslidLoadAddress;
1940 SegmentMappingInfo loc;
1941 loc.srcSegment = (uint8_t*)dylib.input->mappedFile.mh + segInfo.vmAddr - textSegVmAddr;
1942 loc.segName = segInfo.segName;
1943 loc.dstSegment = region.buffer + offsetInRegion;
1944 loc.dstCacheUnslidAddress = addr;
1945 loc.dstCacheFileOffset = (uint32_t)(region.cacheFileOffset + offsetInRegion);
1946 loc.dstCacheSegmentSize = (uint32_t)sizeOfSections;
1947 loc.dstCacheFileSize = (uint32_t)copySize;
1948 loc.copySegmentSize = (uint32_t)copySize;
1949 loc.srcSegmentIndex = segInfo.segIndex;
1950 dylib.cacheLocation.push_back(loc);
1951 addr += loc.dstCacheSegmentSize;
1952 });
1953 }
1954
1955 // align region end
1956 addr = align(addr, _archLayout->sharedRegionAlignP2);
1957 };
1958
1959 struct DataRegion {
1960 const char* regionName;
1961 SegmentType dataSegment;
1962 std::optional<SegmentType> dirtySegment;
1963 // Note this is temporary as once all platforms/archs support __DATA_CONST, we can move to a DataRegion just for CONST
1964 std::optional<SegmentType> dataConstSegment;
1965 bool addCFStrings;
1966 bool addObjCRW;
1967 };
1968 std::vector<DataRegion> dataRegions;
1969
1970 // We only support __DATA_CONST on arm64(e) for now.
1971 bool supportDataConst = false;
1972 //supportDataConst |= strcmp(_archLayout->archName, "arm64") == 0;
1973 supportDataConst |= strcmp(_archLayout->archName, "arm64e") == 0;
1974 if ( supportDataConst ) {
1975 bool addObjCRWToData = !supportsAuthFixups;
1976 DataRegion dataWriteRegion = { "__DATA", SegmentType::data, SegmentType::dataDirty, {}, false, addObjCRWToData };
1977 DataRegion dataConstRegion = { "__DATA_CONST", SegmentType::dataConst, {}, {}, true, false };
1978 DataRegion authWriteRegion = { "__AUTH", SegmentType::auth, SegmentType::authDirty, {}, false, !addObjCRWToData };
1979 DataRegion authConstRegion = { "__AUTH_CONST", SegmentType::authConst, {}, {}, false, false };
1980 dataRegions.push_back(dataWriteRegion);
1981 dataRegions.push_back(dataConstRegion);
1982 if ( supportsAuthFixups ) {
1983 dataRegions.push_back(authWriteRegion);
1984 dataRegions.push_back(authConstRegion);
1985 }
1986 } else {
1987 DataRegion dataWriteRegion = { "__DATA", SegmentType::data, SegmentType::dataDirty, SegmentType::dataConst, false, true };
1988 dataRegions.push_back(dataWriteRegion);
1989 }
1990
1991 for (DataRegion& dataRegion : dataRegions)
1992 {
1993 Region region;
1994 region.buffer = (uint8_t*)_fullAllocatedBuffer + addr - _archLayout->sharedMemoryStart;
1995 region.bufferSize = 0;
1996 region.sizeInUse = 0;
1997 region.unslidLoadAddress = addr;
1998 region.cacheFileOffset = nextRegionFileOffset;
1999 region.name = dataRegion.regionName;
2000 region.initProt = endsWith(dataRegion.regionName, "_CONST") ? VM_PROT_READ : (VM_PROT_READ | VM_PROT_WRITE);
2001 region.maxProt = VM_PROT_READ | VM_PROT_WRITE;
2002
2003 // layout all __DATA_DIRTY segments, sorted (FIXME)
2004 if (dataRegion.dirtySegment.has_value())
2005 processDylibSegments(*dataRegion.dirtySegment, region);
2006
2007 // layout all __DATA segments (and other r/w non-dirty, non-const, non-auth) segments
2008 processDylibSegments(dataRegion.dataSegment, region);
2009
2010 // When __DATA_CONST is not its own DataRegion, we fold it in to the __DATA DataRegion
2011 if (dataRegion.dataConstSegment.has_value())
2012 processDylibSegments(*dataRegion.dataConstSegment, region);
2013
2014 // Make space for the cfstrings
2015 if ( (dataRegion.addCFStrings) && (_coalescedText.cfStrings.bufferSize != 0) ) {
2016 // Keep __DATA segments 4K or more aligned
2017 addr = align(addr, 12);
2018 uint64_t offsetInRegion = addr - region.unslidLoadAddress;
2019
2020 CacheCoalescedText::CFSection& cacheSection = _coalescedText.cfStrings;
2021 cacheSection.bufferAddr = region.buffer + offsetInRegion;
2022 cacheSection.bufferVMAddr = addr;
2023 cacheSection.cacheFileOffset = region.cacheFileOffset + offsetInRegion;
2024 addr += cacheSection.bufferSize;
2025 }
2026
2027 if ( dataRegion.addObjCRW ) {
2028 // reserve space for objc r/w optimization tables
2029 _objcReadWriteBufferSizeAllocated = align(computeReadWriteObjC((uint32_t)_sortedDylibs.size(), totalProtocolDefCount), 14);
2030 addr = align(addr, 4); // objc r/w section contains pointer and must be at least pointer align
2031 _objcReadWriteBuffer = region.buffer + (addr - region.unslidLoadAddress);
2032 _objcReadWriteFileOffset = (uint32_t)((_objcReadWriteBuffer - region.buffer) + region.cacheFileOffset);
2033 addr += _objcReadWriteBufferSizeAllocated;
2034
2035
2036 // align region end
2037 addr = align(addr, _archLayout->sharedRegionAlignP2);
2038 }
2039
2040 // align DATA region end
2041 uint64_t endDataAddress = addr;
2042 region.bufferSize = endDataAddress - region.unslidLoadAddress;
2043 region.sizeInUse = region.bufferSize;
2044
2045 _dataRegions.push_back(region);
2046 nextRegionFileOffset = region.cacheFileOffset + region.sizeInUse;
2047
2048 // Only arm64 and arm64e shared caches have enough space to pad between __DATA and __DATA_CONST
2049 // All other caches are overflowing.
2050 if ( !strcmp(_archLayout->archName, "arm64") || !strcmp(_archLayout->archName, "arm64e") )
2051 addr = align((addr + _archLayout->sharedRegionPadding), _archLayout->sharedRegionAlignP2);
2052 }
2053
2054 // Sanity check that we didn't put the same segment in 2 different ranges
2055 for (DylibInfo& dylib : _sortedDylibs) {
2056 std::unordered_set<uint64_t> seenSegmentIndices;
2057 for (SegmentMappingInfo& segmentInfo : dylib.cacheLocation) {
2058 if ( seenSegmentIndices.count(segmentInfo.srcSegmentIndex) != 0 ) {
2059 _diagnostics.error("%s segment %s was duplicated in layout",
2060 dylib.input->mappedFile.mh->installName(), segmentInfo.segName);
2061 return;
2062 }
2063 seenSegmentIndices.insert(segmentInfo.srcSegmentIndex);
2064 }
2065 }
2066 }
2067
2068 void SharedCacheBuilder::assignSegmentAddresses()
2069 {
2070 // calculate size of header info and where first dylib's mach_header should start
2071 size_t startOffset = sizeof(dyld_cache_header) + DyldSharedCache::MaxMappings * sizeof(dyld_cache_mapping_info);
2072 startOffset += DyldSharedCache::MaxMappings * sizeof(dyld_cache_mapping_and_slide_info);
2073 startOffset += sizeof(dyld_cache_image_info) * _sortedDylibs.size();
2074 startOffset += sizeof(dyld_cache_image_text_info) * _sortedDylibs.size();
2075 for (const DylibInfo& dylib : _sortedDylibs) {
2076 startOffset += (strlen(dylib.input->mappedFile.mh->installName()) + 1);
2077 }
2078 //fprintf(stderr, "%s total header size = 0x%08lX\n", _options.archName.c_str(), startOffset);
2079 startOffset = align(startOffset, 12);
2080
2081 // HACK!: Rebase v4 assumes that values below 0x8000 are not pointers (encoding as offsets from the cache header).
2082 // If using a minimal cache, we need to pad out the cache header to make sure a pointer doesn't fall within that range
2083 #if SUPPORT_ARCH_arm64_32 || SUPPORT_ARCH_armv7k
2084 if ( _options.cacheSupportsASLR && !_archLayout->is64 ) {
2085 if ( _archLayout->pointerDeltaMask == 0xC0000000 )
2086 startOffset = std::max(startOffset, (size_t)0x8000);
2087 }
2088 #endif
2089
2090 // assign TEXT segment addresses
2091 _readExecuteRegion.buffer = (uint8_t*)_fullAllocatedBuffer;
2092 _readExecuteRegion.bufferSize = 0;
2093 _readExecuteRegion.sizeInUse = 0;
2094 _readExecuteRegion.unslidLoadAddress = _archLayout->sharedMemoryStart;
2095 _readExecuteRegion.cacheFileOffset = 0;
2096 __block uint64_t addr = _readExecuteRegion.unslidLoadAddress + startOffset; // header
2097 for (DylibInfo& dylib : _sortedDylibs) {
2098 __block uint64_t textSegVmAddr = 0;
2099 dylib.input->mappedFile.mh->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& segInfo, bool& stop) {
2100 if ( strcmp(segInfo.segName, "__TEXT") == 0 )
2101 textSegVmAddr = segInfo.vmAddr;
2102 if ( segInfo.protections != (VM_PROT_READ | VM_PROT_EXECUTE) )
2103 return;
2104 // We may have coalesced the sections at the end of this segment. In that case, shrink the segment to remove them.
2105 __block size_t sizeOfSections = 0;
2106 __block bool foundCoalescedSection = false;
2107 dylib.input->mappedFile.mh->forEachSection(^(const dyld3::MachOAnalyzer::SectionInfo &sectInfo, bool malformedSectionRange, bool &stopSection) {
2108 if (strcmp(sectInfo.segInfo.segName, segInfo.segName) != 0)
2109 return;
2110 if ( dylib.textCoalescer.sectionWasCoalesced(segInfo.segName, sectInfo.sectName)) {
2111 foundCoalescedSection = true;
2112 } else {
2113 sizeOfSections = sectInfo.sectAddr + sectInfo.sectSize - segInfo.vmAddr;
2114 }
2115 });
2116 if (!foundCoalescedSection)
2117 sizeOfSections = segInfo.sizeOfSections;
2118
2119 // Keep __TEXT segments 4K or more aligned
2120 addr = align(addr, std::max((int)segInfo.p2align, (int)12));
2121 uint64_t offsetInRegion = addr - _readExecuteRegion.unslidLoadAddress;
2122 SegmentMappingInfo loc;
2123 loc.srcSegment = (uint8_t*)dylib.input->mappedFile.mh + segInfo.vmAddr - textSegVmAddr;
2124 loc.segName = segInfo.segName;
2125 loc.dstSegment = _readExecuteRegion.buffer + offsetInRegion;
2126 loc.dstCacheUnslidAddress = addr;
2127 loc.dstCacheFileOffset = (uint32_t)offsetInRegion;
2128 loc.dstCacheSegmentSize = (uint32_t)align(sizeOfSections, 12);
2129 loc.dstCacheFileSize = (uint32_t)align(sizeOfSections, 12);
2130 loc.copySegmentSize = (uint32_t)sizeOfSections;
2131 loc.srcSegmentIndex = segInfo.segIndex;
2132 dylib.cacheLocation.push_back(loc);
2133 addr += loc.dstCacheSegmentSize;
2134 });
2135 }
2136
2137 // reserve space for objc optimization tables and deduped strings
2138 uint64_t objcReadOnlyBufferVMAddr = addr;
2139 _objcReadOnlyBuffer = _readExecuteRegion.buffer + (addr - _readExecuteRegion.unslidLoadAddress);
2140
2141 // First the strings as we'll fill in the objc tables later in the optimizer
2142 for (const char* section: CacheCoalescedText::SupportedSections) {
2143 CacheCoalescedText::StringSection& cacheStringSection = _coalescedText.getSectionData(section);
2144 cacheStringSection.bufferAddr = _readExecuteRegion.buffer + (addr - _readExecuteRegion.unslidLoadAddress);
2145 cacheStringSection.bufferVMAddr = addr;
2146 addr += cacheStringSection.bufferSize;
2147 }
2148
2149 addr = align(addr, 14);
2150 _objcReadOnlyBufferSizeUsed = addr - objcReadOnlyBufferVMAddr;
2151
2152 uint32_t totalSelectorRefCount = (uint32_t)_selectorStringsFromExecutables;
2153 uint32_t totalClassDefCount = 0;
2154 uint32_t totalProtocolDefCount = 0;
2155 for (DylibInfo& dylib : _sortedDylibs) {
2156 dyld3::MachOAnalyzer::ObjCInfo info = dylib.input->mappedFile.mh->getObjCInfo();
2157 totalSelectorRefCount += info.selRefCount;
2158 totalClassDefCount += info.classDefCount;
2159 totalProtocolDefCount += info.protocolDefCount;
2160 }
2161
2162 // now that shared cache coalesces all selector strings, use that better count
2163 uint32_t coalescedSelectorCount = (uint32_t)_coalescedText.objcMethNames.stringsToOffsets.size();
2164 if ( coalescedSelectorCount > totalSelectorRefCount )
2165 totalSelectorRefCount = coalescedSelectorCount;
2166 addr += align(computeReadOnlyObjC(totalSelectorRefCount, totalClassDefCount, totalProtocolDefCount), 14);
2167
2168 size_t impCachesSize = _impCachesBuilder->totalIMPCachesSize();
2169 size_t alignedImpCachesSize = align(impCachesSize, 14);
2170 _diagnostics.verbose("Reserving %zd bytes for IMP caches (aligned to %zd)\n", impCachesSize, alignedImpCachesSize);
2171 addr += alignedImpCachesSize;
2172
2173 _objcReadOnlyBufferSizeAllocated = addr - objcReadOnlyBufferVMAddr;
2174
2175 // align TEXT region end
2176 uint64_t endTextAddress = align(addr, _archLayout->sharedRegionAlignP2);
2177 _readExecuteRegion.bufferSize = endTextAddress - _readExecuteRegion.unslidLoadAddress;
2178 _readExecuteRegion.sizeInUse = _readExecuteRegion.bufferSize;
2179
2180
2181 // assign __DATA* addresses
2182 if ( _archLayout->sharedRegionsAreDiscontiguous )
2183 addr = DISCONTIGUOUS_RW;
2184 else
2185 addr = align((addr + _archLayout->sharedRegionPadding), _archLayout->sharedRegionAlignP2);
2186
2187 // __DATA*
2188 assignMultipleDataSegmentAddresses(addr, totalProtocolDefCount);
2189
2190 // start read-only region
2191 if ( _archLayout->sharedRegionsAreDiscontiguous )
2192 addr = DISCONTIGUOUS_RO;
2193 else
2194 addr = align((addr + _archLayout->sharedRegionPadding), _archLayout->sharedRegionAlignP2);
2195 _readOnlyRegion.buffer = (uint8_t*)_fullAllocatedBuffer + addr - _archLayout->sharedMemoryStart;
2196 _readOnlyRegion.bufferSize = 0;
2197 _readOnlyRegion.sizeInUse = 0;
2198 _readOnlyRegion.unslidLoadAddress = addr;
2199 _readOnlyRegion.cacheFileOffset = lastDataRegion()->cacheFileOffset + lastDataRegion()->sizeInUse;
2200
2201
2202 // reserve space for kernel ASLR slide info at start of r/o region
2203 if ( _options.cacheSupportsASLR ) {
2204 size_t slideInfoSize = sizeof(dyld_cache_slide_info);
2205 slideInfoSize = std::max(slideInfoSize, sizeof(dyld_cache_slide_info2));
2206 slideInfoSize = std::max(slideInfoSize, sizeof(dyld_cache_slide_info3));
2207 slideInfoSize = std::max(slideInfoSize, sizeof(dyld_cache_slide_info4));
2208 // We need one slide info header per data region, plus enough space for that regions pages
2209 // Each region will also be padded to a page-size so that the kernel can wire it.
2210 for (Region& region : _dataRegions) {
2211 uint64_t offsetInRegion = addr - _readOnlyRegion.unslidLoadAddress;
2212 region.slideInfoBuffer = _readOnlyRegion.buffer + offsetInRegion;
2213 region.slideInfoBufferSizeAllocated = align(slideInfoSize + (region.sizeInUse/4096) * _archLayout->slideInfoBytesPerPage + 0x4000, _archLayout->sharedRegionAlignP2);
2214 region.slideInfoFileOffset = _readOnlyRegion.cacheFileOffset + offsetInRegion;
2215 addr += region.slideInfoBufferSizeAllocated;
2216 }
2217 }
2218
2219 // layout all read-only (but not LINKEDIT) segments
2220 for (DylibInfo& dylib : _sortedDylibs) {
2221 __block uint64_t textSegVmAddr = 0;
2222 dylib.input->mappedFile.mh->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& segInfo, bool& stop) {
2223 if ( strcmp(segInfo.segName, "__TEXT") == 0 )
2224 textSegVmAddr = segInfo.vmAddr;
2225 if ( segInfo.protections != VM_PROT_READ )
2226 return;
2227 if ( strcmp(segInfo.segName, "__LINKEDIT") == 0 )
2228 return;
2229
2230 // Keep segments segments 4K or more aligned
2231 addr = align(addr, std::max((int)segInfo.p2align, (int)12));
2232 uint64_t offsetInRegion = addr - _readOnlyRegion.unslidLoadAddress;
2233 SegmentMappingInfo loc;
2234 loc.srcSegment = (uint8_t*)dylib.input->mappedFile.mh + segInfo.vmAddr - textSegVmAddr;
2235 loc.segName = segInfo.segName;
2236 loc.dstSegment = _readOnlyRegion.buffer + offsetInRegion;
2237 loc.dstCacheUnslidAddress = addr;
2238 loc.dstCacheFileOffset = (uint32_t)(_readOnlyRegion.cacheFileOffset + offsetInRegion);
2239 loc.dstCacheSegmentSize = (uint32_t)align(segInfo.sizeOfSections, 12);
2240 loc.dstCacheFileSize = (uint32_t)segInfo.sizeOfSections;
2241 loc.copySegmentSize = (uint32_t)segInfo.sizeOfSections;
2242 loc.srcSegmentIndex = segInfo.segIndex;
2243 dylib.cacheLocation.push_back(loc);
2244 addr += loc.dstCacheSegmentSize;
2245 });
2246 }
2247
2248 // layout all LINKEDIT segments (after other read-only segments), aligned to 16KB
2249 addr = align(addr, 14);
2250 _nonLinkEditReadOnlySize = addr - _readOnlyRegion.unslidLoadAddress;
2251 for (DylibInfo& dylib : _sortedDylibs) {
2252 __block uint64_t textSegVmAddr = 0;
2253 dylib.input->mappedFile.mh->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& segInfo, bool& stop) {
2254 if ( strcmp(segInfo.segName, "__TEXT") == 0 )
2255 textSegVmAddr = segInfo.vmAddr;
2256 if ( segInfo.protections != VM_PROT_READ )
2257 return;
2258 if ( strcmp(segInfo.segName, "__LINKEDIT") != 0 )
2259 return;
2260 // Keep segments segments 4K or more aligned
2261 addr = align(addr, std::max((int)segInfo.p2align, (int)12));
2262 size_t copySize = std::min((size_t)segInfo.fileSize, (size_t)segInfo.sizeOfSections);
2263 uint64_t offsetInRegion = addr - _readOnlyRegion.unslidLoadAddress;
2264 SegmentMappingInfo loc;
2265 loc.srcSegment = (uint8_t*)dylib.input->mappedFile.mh + segInfo.vmAddr - textSegVmAddr;
2266 loc.segName = segInfo.segName;
2267 loc.dstSegment = _readOnlyRegion.buffer + offsetInRegion;
2268 loc.dstCacheUnslidAddress = addr;
2269 loc.dstCacheFileOffset = (uint32_t)(_readOnlyRegion.cacheFileOffset + offsetInRegion);
2270 loc.dstCacheSegmentSize = (uint32_t)align(segInfo.sizeOfSections, 12);
2271 loc.dstCacheFileSize = (uint32_t)copySize;
2272 loc.copySegmentSize = (uint32_t)copySize;
2273 loc.srcSegmentIndex = segInfo.segIndex;
2274 dylib.cacheLocation.push_back(loc);
2275 addr += loc.dstCacheSegmentSize;
2276 });
2277 }
2278
2279 // align r/o region end
2280 addr = align(addr, _archLayout->sharedRegionAlignP2);
2281 uint64_t endReadOnlyAddress = addr;
2282 _readOnlyRegion.bufferSize = endReadOnlyAddress - _readOnlyRegion.unslidLoadAddress + 0x100000;
2283 _readOnlyRegion.sizeInUse = _readOnlyRegion.bufferSize;
2284
2285 //fprintf(stderr, "RX region=%p -> %p, logical addr=0x%llX\n", _readExecuteRegion.buffer, _readExecuteRegion.buffer+_readExecuteRegion.bufferSize, _readExecuteRegion.unslidLoadAddress);
2286 //fprintf(stderr, "RW region=%p -> %p, logical addr=0x%llX\n", readWriteRegion.buffer, readWriteRegion.buffer+readWriteRegion.bufferSize, readWriteRegion.unslidLoadAddress);
2287 //fprintf(stderr, "RO region=%p -> %p, logical addr=0x%llX\n", _readOnlyRegion.buffer, _readOnlyRegion.buffer+_readOnlyRegion.bufferSize, _readOnlyRegion.unslidLoadAddress);
2288
2289 // sort SegmentMappingInfo for each image to be in the same order as original segments
2290 for (DylibInfo& dylib : _sortedDylibs) {
2291 std::sort(dylib.cacheLocation.begin(), dylib.cacheLocation.end(), [&](const SegmentMappingInfo& a, const SegmentMappingInfo& b) {
2292 return a.srcSegmentIndex < b.srcSegmentIndex;
2293 });
2294 }
2295 }
2296
2297 // Return the total size of the data regions, including padding between them.
2298 // Note this assumes they are contiguous, or that we don't care about including
2299 // additional space between them.
2300 uint64_t SharedCacheBuilder::dataRegionsTotalSize() const {
2301 const Region* firstRegion = nullptr;
2302 const Region* lastRegion = nullptr;
2303 for (const Region& region : _dataRegions) {
2304 if ( (firstRegion == nullptr) || (region.buffer < firstRegion->buffer) )
2305 firstRegion = &region;
2306 if ( (lastRegion == nullptr) || (region.buffer > lastRegion->buffer) )
2307 lastRegion = &region;
2308 }
2309 return (lastRegion->buffer - firstRegion->buffer) + lastRegion->sizeInUse;
2310 }
2311
2312
2313 // Return the total size of the data regions, excluding padding between them
2314 uint64_t SharedCacheBuilder::dataRegionsSizeInUse() const {
2315 size_t size = 0;
2316 for (const Region& dataRegion : _dataRegions)
2317 size += dataRegion.sizeInUse;
2318 return size;
2319 }
2320
2321 // Return the earliest data region by address
2322 const CacheBuilder::Region* SharedCacheBuilder::firstDataRegion() const {
2323 const Region* firstRegion = nullptr;
2324 for (const Region& region : _dataRegions) {
2325 if ( (firstRegion == nullptr) || (region.buffer < firstRegion->buffer) )
2326 firstRegion = &region;
2327 }
2328 return firstRegion;
2329 }
2330
2331 // Return the lateset data region by address
2332 const CacheBuilder::Region* SharedCacheBuilder::lastDataRegion() const {
2333 const Region* lastRegion = nullptr;
2334 for (const Region& region : _dataRegions) {
2335 if ( (lastRegion == nullptr) || (region.buffer > lastRegion->buffer) )
2336 lastRegion = &region;
2337 }
2338 return lastRegion;
2339 }
2340 static dyld_cache_patchable_location makePatchLocation(size_t cacheOff, dyld3::MachOAnalyzerSet::PointerMetaData pmd, uint64_t addend) {
2341 dyld_cache_patchable_location patch;
2342 patch.cacheOffset = cacheOff;
2343 patch.high7 = pmd.high8 >> 1;
2344 patch.addend = addend;
2345 patch.authenticated = pmd.authenticated;
2346 patch.usesAddressDiversity = pmd.usesAddrDiversity;
2347 patch.key = pmd.key;
2348 patch.discriminator = pmd.diversity;
2349 // check for truncations
2350 assert(patch.cacheOffset == cacheOff);
2351 assert(patch.addend == addend);
2352 assert((patch.high7 << 1) == pmd.high8);
2353 return patch;
2354 }
2355
2356 void SharedCacheBuilder::buildImageArray(std::vector<DyldSharedCache::FileAlias>& aliases)
2357 {
2358 typedef dyld3::closure::ClosureBuilder::CachedDylibInfo CachedDylibInfo;
2359
2360 // convert STL data structures to simple arrays to passe to makeDyldCacheImageArray()
2361 __block std::vector<CachedDylibInfo> dylibInfos;
2362 __block std::unordered_map<dyld3::closure::ImageNum, const dyld3::MachOLoaded*> imageNumToML;
2363 DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
2364 cache->forEachImage(^(const mach_header* mh, const char* installName) {
2365 const dyld3::MachOLoaded* ml = (dyld3::MachOLoaded*)mh;
2366 if ( !_someDylibsUsedChainedFixups && ml->hasChainedFixups() )
2367 _someDylibsUsedChainedFixups = true;
2368 uint64_t mtime;
2369 uint64_t inode;
2370 cache->getIndexedImageEntry((uint32_t)dylibInfos.size(), mtime, inode);
2371 CachedDylibInfo entry;
2372 entry.fileInfo.fileContent = mh;
2373 entry.fileInfo.path = installName;
2374 entry.fileInfo.sliceOffset = 0;
2375 entry.fileInfo.inode = inode;
2376 entry.fileInfo.mtime = mtime;
2377 dylibInfos.push_back(entry);
2378 imageNumToML[(dyld3::closure::ImageNum)(dylibInfos.size())] = ml;
2379 });
2380
2381 // Convert symlinks from STL to simple char pointers.
2382 std::vector<dyld3::closure::ClosureBuilder::CachedDylibAlias> dylibAliases;
2383 dylibAliases.reserve(aliases.size());
2384 for (const auto& alias : aliases)
2385 dylibAliases.push_back({ alias.realPath.c_str(), alias.aliasPath.c_str() });
2386
2387 typedef dyld3::MachOAnalyzerSet::FixupTarget FixupTarget;
2388 typedef dyld3::MachOAnalyzerSet::PointerMetaData PointerMetaData;
2389
2390 dyld3::closure::ClosureBuilder::DylibFixupHandler handler = ^(const dyld3::MachOLoaded* fixupIn, uint64_t fixupLocRuntimeOffset,
2391 PointerMetaData pmd, const FixupTarget& target) {
2392 uint8_t* fixupLoc = (uint8_t*)fixupIn + fixupLocRuntimeOffset;
2393 uint32_t* fixupLoc32 = (uint32_t*)fixupLoc;
2394 uint64_t* fixupLoc64 = (uint64_t*)fixupLoc;
2395 uint64_t targetSymbolOffsetInCache;
2396 switch ( target.kind ) {
2397 case FixupTarget::Kind::rebase:
2398 // rebasing already done in AdjustDylibSegments, but if input dylib uses chained fixups, target might not fit
2399 if ( _archLayout->is64 ) {
2400 if ( pmd.authenticated )
2401 _aslrTracker.setAuthData(fixupLoc, pmd.diversity, pmd.usesAddrDiversity, pmd.key);
2402 if ( pmd.high8 )
2403 _aslrTracker.setHigh8(fixupLoc, pmd.high8);
2404 uint64_t targetVmAddr;
2405 if ( _aslrTracker.hasRebaseTarget64(fixupLoc, &targetVmAddr) )
2406 *fixupLoc64 = targetVmAddr;
2407 else
2408 *fixupLoc64 = (uint8_t*)target.foundInImage._mh - _readExecuteRegion.buffer + target.offsetInImage + _readExecuteRegion.unslidLoadAddress;
2409 }
2410 else {
2411 uint32_t targetVmAddr;
2412 assert(_aslrTracker.hasRebaseTarget32(fixupLoc, &targetVmAddr) && "32-bit archs always store target in side table");
2413 *fixupLoc32 = targetVmAddr;
2414 }
2415 break;
2416 case FixupTarget::Kind::bindAbsolute:
2417 if ( _archLayout->is64 )
2418 *fixupLoc64 = target.offsetInImage;
2419 else
2420 *fixupLoc32 = (uint32_t)(target.offsetInImage);
2421 // don't record absolute targets for ASLR
2422 _aslrTracker.remove(fixupLoc);
2423 break;
2424 case FixupTarget::Kind::bindToImage:
2425 targetSymbolOffsetInCache = (uint8_t*)target.foundInImage._mh - _readExecuteRegion.buffer + target.offsetInImage - target.addend;
2426 if ( !target.weakCoalesced || !_aslrTracker.has(fixupLoc) ) {
2427 // this handler is called a second time for weak_bind info, which we ignore when building cache
2428 _aslrTracker.add(fixupLoc);
2429 if ( _archLayout->is64 ) {
2430 if ( pmd.high8 )
2431 _aslrTracker.setHigh8(fixupLoc, pmd.high8);
2432 if ( pmd.authenticated )
2433 _aslrTracker.setAuthData(fixupLoc, pmd.diversity, pmd.usesAddrDiversity, pmd.key);
2434 *fixupLoc64 = _archLayout->sharedMemoryStart + targetSymbolOffsetInCache + target.addend;
2435 }
2436 else {
2437 assert(targetSymbolOffsetInCache < (_readOnlyRegion.buffer - _readExecuteRegion.buffer) && "offset not into TEXT or DATA of cache file");
2438 uint32_t targetVmAddr;
2439 if ( _aslrTracker.hasRebaseTarget32(fixupLoc, &targetVmAddr) )
2440 *fixupLoc32 = targetVmAddr;
2441 else
2442 *fixupLoc32 = (uint32_t)(_archLayout->sharedMemoryStart + targetSymbolOffsetInCache + target.addend);
2443 }
2444 }
2445 _dylibToItsExports[target.foundInImage._mh].insert(targetSymbolOffsetInCache);
2446 if ( target.isWeakDef )
2447 _dylibWeakExports.insert({ target.foundInImage._mh, targetSymbolOffsetInCache });
2448 _exportsToUses[targetSymbolOffsetInCache].push_back(makePatchLocation(fixupLoc - _readExecuteRegion.buffer, pmd, target.addend));
2449 _exportsToName[targetSymbolOffsetInCache] = target.foundSymbolName;
2450 break;
2451 case FixupTarget::Kind::bindMissingSymbol:
2452 // if there are missing symbols, makeDyldCacheImageArray() will error
2453 break;
2454 }
2455 };
2456
2457
2458 // build ImageArray for all dylibs in dyld cache
2459 dyld3::closure::PathOverrides pathOverrides;
2460 dyld3::RootsChecker rootsChecker;
2461 dyld3::closure::ClosureBuilder cb(dyld3::closure::kFirstDyldCacheImageNum, _fileSystem, rootsChecker, cache, false, *_options.archs, pathOverrides,
2462 dyld3::closure::ClosureBuilder::AtPath::none, false, nullptr, _options.platform, handler);
2463 dyld3::Array<CachedDylibInfo> dylibs(&dylibInfos[0], dylibInfos.size(), dylibInfos.size());
2464 const dyld3::Array<dyld3::closure::ClosureBuilder::CachedDylibAlias> aliasesArray(dylibAliases.data(), dylibAliases.size(), dylibAliases.size());
2465 _imageArray = cb.makeDyldCacheImageArray(dylibs, aliasesArray);
2466 if ( cb.diagnostics().hasError() ) {
2467 _diagnostics.error("%s", cb.diagnostics().errorMessage().c_str());
2468 return;
2469 }
2470 }
2471
2472 static bool operator==(const dyld_cache_patchable_location& a, const dyld_cache_patchable_location& b) {
2473 return a.cacheOffset == b.cacheOffset;
2474 }
2475
2476 void SharedCacheBuilder::addImageArray()
2477 {
2478 // build trie of dylib paths
2479 __block std::vector<DylibIndexTrie::Entry> dylibEntrys;
2480 _imageArray->forEachImage(^(const dyld3::closure::Image* image, bool& stop) {
2481 dylibEntrys.push_back(DylibIndexTrie::Entry(image->path(), DylibIndex(image->imageNum()-1)));
2482 image->forEachAlias(^(const char *aliasPath, bool &innerStop) {
2483 dylibEntrys.push_back(DylibIndexTrie::Entry(aliasPath, DylibIndex(image->imageNum()-1)));
2484 });
2485 });
2486 DylibIndexTrie dylibsTrie(dylibEntrys);
2487 std::vector<uint8_t> trieBytes;
2488 dylibsTrie.emit(trieBytes);
2489 while ( (trieBytes.size() % 4) != 0 )
2490 trieBytes.push_back(0);
2491
2492 // build set of functions to never stub-eliminate because tools may need to override them
2493 std::unordered_set<std::string> alwaysGeneratePatch;
2494 for (const char* const* p=_s_neverStubEliminateSymbols; *p != nullptr; ++p)
2495 alwaysGeneratePatch.insert(*p);
2496
2497 // Add the patches for the image array.
2498 __block uint64_t numPatchImages = _imageArray->size();
2499 __block uint64_t numPatchExports = 0;
2500 __block uint64_t numPatchLocations = 0;
2501 __block uint64_t numPatchExportNameBytes = 0;
2502
2503 auto needsPatch = [&](bool dylibNeedsPatching, const dyld3::MachOLoaded* mh,
2504 CacheOffset offset) -> bool {
2505 if (dylibNeedsPatching)
2506 return true;
2507 if (_dylibWeakExports.find({ mh, offset }) != _dylibWeakExports.end())
2508 return true;
2509 const std::string& exportName = _exportsToName[offset];
2510 return alwaysGeneratePatch.find(exportName) != alwaysGeneratePatch.end();
2511 };
2512
2513 // First calculate how much space we need
2514 const DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
2515 cache->forEachImage(^(const mach_header* mh, const char* installName) {
2516 const dyld3::MachOLoaded* ml = (const dyld3::MachOLoaded*)mh;
2517 const std::set<CacheOffset>& dylibExports = _dylibToItsExports[ml];
2518
2519 // On a customer cache, only store patch locations for interposable dylibs and weak binding
2520 bool dylibNeedsPatching = cache->isOverridablePath(installName);
2521
2522 uint64_t numDylibExports = 0;
2523 for (CacheOffset exportCacheOffset : dylibExports) {
2524 if (!needsPatch(dylibNeedsPatching, ml, exportCacheOffset))
2525 continue;
2526 std::vector<dyld_cache_patchable_location>& uses = _exportsToUses[exportCacheOffset];
2527 uses.erase(std::unique(uses.begin(), uses.end()), uses.end());
2528 numPatchLocations += uses.size();
2529
2530 std::string exportName = _exportsToName[exportCacheOffset];
2531 numPatchExportNameBytes += exportName.size() + 1;
2532 }
2533 numPatchExports += numDylibExports;
2534 });
2535
2536 // Now reserve the space
2537 __block std::vector<dyld_cache_image_patches> patchImages;
2538 __block std::vector<dyld_cache_patchable_export> patchExports;
2539 __block std::vector<dyld_cache_patchable_location> patchLocations;
2540 __block std::vector<char> patchExportNames;
2541
2542 patchImages.reserve(numPatchImages);
2543 patchExports.reserve(numPatchExports);
2544 patchLocations.reserve(numPatchLocations);
2545 patchExportNames.reserve(numPatchExportNameBytes);
2546
2547 // And now fill it with the patch data
2548 cache->forEachImage(^(const mach_header* mh, const char* installName) {
2549 const dyld3::MachOLoaded* ml = (const dyld3::MachOLoaded*)mh;
2550 const std::set<CacheOffset>& dylibExports = _dylibToItsExports[ml];
2551
2552 // On a customer cache, only store patch locations for interposable dylibs and weak binding
2553 bool dylibNeedsPatching = cache->isOverridablePath(installName);
2554
2555 // Add the patch image which points in to the exports
2556 dyld_cache_image_patches patchImage;
2557 patchImage.patchExportsStartIndex = (uint32_t)patchExports.size();
2558 patchImage.patchExportsCount = 0;
2559
2560 // Then add each export which points to a list of locations and a name
2561 for (CacheOffset exportCacheOffset : dylibExports) {
2562 if (!needsPatch(dylibNeedsPatching, ml, exportCacheOffset))
2563 continue;
2564 ++patchImage.patchExportsCount;
2565 std::vector<dyld_cache_patchable_location>& uses = _exportsToUses[exportCacheOffset];
2566
2567 dyld_cache_patchable_export cacheExport;
2568 cacheExport.cacheOffsetOfImpl = (uint32_t)exportCacheOffset;
2569 cacheExport.patchLocationsStartIndex = (uint32_t)patchLocations.size();
2570 cacheExport.patchLocationsCount = (uint32_t)uses.size();
2571 cacheExport.exportNameOffset = (uint32_t)patchExportNames.size();
2572 patchExports.push_back(cacheExport);
2573
2574 // Now add the list of locations.
2575 patchLocations.insert(patchLocations.end(), uses.begin(), uses.end());
2576
2577 // And add the export name
2578 const std::string& exportName = _exportsToName[exportCacheOffset];
2579 patchExportNames.insert(patchExportNames.end(), &exportName[0], &exportName[0] + exportName.size() + 1);
2580 }
2581 patchImages.push_back(patchImage);
2582 });
2583
2584 while ( (patchExportNames.size() % 4) != 0 )
2585 patchExportNames.push_back('\0');
2586
2587 uint64_t patchInfoSize = sizeof(dyld_cache_patch_info);
2588 patchInfoSize += sizeof(dyld_cache_image_patches) * patchImages.size();
2589 patchInfoSize += sizeof(dyld_cache_patchable_export) * patchExports.size();
2590 patchInfoSize += sizeof(dyld_cache_patchable_location) * patchLocations.size();
2591 patchInfoSize += patchExportNames.size();
2592
2593 // check for fit
2594 uint64_t imageArraySize = _imageArray->size();
2595 size_t freeSpace = _readOnlyRegion.bufferSize - _readOnlyRegion.sizeInUse;
2596 if ( (imageArraySize+trieBytes.size()+patchInfoSize) > freeSpace ) {
2597 _diagnostics.error("cache buffer too small to hold ImageArray and Trie (buffer size=%lldMB, imageArray size=%lldMB, trie size=%luKB, patch size=%lluKB, free space=%ldMB)",
2598 _allocatedBufferSize/1024/1024, imageArraySize/1024/1024, trieBytes.size()/1024, patchInfoSize/1024, freeSpace/1024/1024);
2599 return;
2600 }
2601
2602 // copy into cache and update header
2603 DyldSharedCache* dyldCache = (DyldSharedCache*)_readExecuteRegion.buffer;
2604 dyldCache->header.dylibsImageArrayAddr = _readOnlyRegion.unslidLoadAddress + _readOnlyRegion.sizeInUse;
2605 dyldCache->header.dylibsImageArraySize = imageArraySize;
2606 dyldCache->header.dylibsTrieAddr = dyldCache->header.dylibsImageArrayAddr + imageArraySize;
2607 dyldCache->header.dylibsTrieSize = trieBytes.size();
2608 ::memcpy(_readOnlyRegion.buffer + _readOnlyRegion.sizeInUse, _imageArray, imageArraySize);
2609 ::memcpy(_readOnlyRegion.buffer + _readOnlyRegion.sizeInUse + imageArraySize, &trieBytes[0], trieBytes.size());
2610
2611 // Also write out the patch info
2612 dyldCache->header.patchInfoAddr = dyldCache->header.dylibsTrieAddr + dyldCache->header.dylibsTrieSize;
2613 dyldCache->header.patchInfoSize = patchInfoSize;
2614 dyld_cache_patch_info patchInfo;
2615 patchInfo.patchTableArrayAddr = dyldCache->header.patchInfoAddr + sizeof(dyld_cache_patch_info);
2616 patchInfo.patchTableArrayCount = patchImages.size();
2617 patchInfo.patchExportArrayAddr = patchInfo.patchTableArrayAddr + (patchInfo.patchTableArrayCount * sizeof(dyld_cache_image_patches));
2618 patchInfo.patchExportArrayCount = patchExports.size();
2619 patchInfo.patchLocationArrayAddr = patchInfo.patchExportArrayAddr + (patchInfo.patchExportArrayCount * sizeof(dyld_cache_patchable_export));
2620 patchInfo.patchLocationArrayCount = patchLocations.size();
2621 patchInfo.patchExportNamesAddr = patchInfo.patchLocationArrayAddr + (patchInfo.patchLocationArrayCount * sizeof(dyld_cache_patchable_location));
2622 patchInfo.patchExportNamesSize = patchExportNames.size();
2623 ::memcpy(_readOnlyRegion.buffer + dyldCache->header.patchInfoAddr - _readOnlyRegion.unslidLoadAddress,
2624 &patchInfo, sizeof(dyld_cache_patch_info));
2625 ::memcpy(_readOnlyRegion.buffer + patchInfo.patchTableArrayAddr - _readOnlyRegion.unslidLoadAddress,
2626 &patchImages[0], sizeof(patchImages[0]) * patchImages.size());
2627 ::memcpy(_readOnlyRegion.buffer + patchInfo.patchExportArrayAddr - _readOnlyRegion.unslidLoadAddress,
2628 &patchExports[0], sizeof(patchExports[0]) * patchExports.size());
2629 ::memcpy(_readOnlyRegion.buffer + patchInfo.patchLocationArrayAddr - _readOnlyRegion.unslidLoadAddress,
2630 &patchLocations[0], sizeof(patchLocations[0]) * patchLocations.size());
2631 ::memcpy(_readOnlyRegion.buffer + patchInfo.patchExportNamesAddr - _readOnlyRegion.unslidLoadAddress,
2632 &patchExportNames[0], patchExportNames.size());
2633
2634 _readOnlyRegion.sizeInUse += align(imageArraySize+trieBytes.size()+patchInfoSize,14);
2635
2636 // Free the underlying image array buffer
2637 _imageArray->deallocate();
2638 _imageArray = nullptr;
2639 }
2640
2641 void SharedCacheBuilder::addOtherImageArray(const std::vector<LoadedMachO>& otherDylibsAndBundles, std::vector<const LoadedMachO*>& overflowDylibs)
2642 {
2643 DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
2644 dyld3::closure::PathOverrides pathOverrides;
2645 dyld3::closure::FileSystemNull nullFileSystem;
2646 dyld3::RootsChecker rootsChecker;
2647 dyld3::closure::ClosureBuilder cb(dyld3::closure::kFirstOtherOSImageNum, nullFileSystem, rootsChecker, cache, false, *_options.archs, pathOverrides,
2648 dyld3::closure::ClosureBuilder::AtPath::none, false, nullptr, _options.platform);
2649
2650 // make ImageArray for other dylibs and bundles
2651 STACK_ALLOC_ARRAY(dyld3::closure::LoadedFileInfo, others, otherDylibsAndBundles.size() + overflowDylibs.size());
2652 for (const LoadedMachO& other : otherDylibsAndBundles) {
2653 if ( !contains(other.loadedFileInfo.path, "staged_system_apps/") )
2654 others.push_back(other.loadedFileInfo);
2655 }
2656
2657 for (const LoadedMachO* dylib : overflowDylibs) {
2658 if (dylib->mappedFile.mh->canHavePrecomputedDlopenClosure(dylib->mappedFile.runtimePath.c_str(), ^(const char*) {}) )
2659 others.push_back(dylib->loadedFileInfo);
2660 }
2661
2662 // Sort the others array by name so that it is deterministic
2663 std::sort(others.begin(), others.end(),
2664 [](const dyld3::closure::LoadedFileInfo& a, const dyld3::closure::LoadedFileInfo& b) {
2665 // Sort mac before iOSMac
2666 bool isIOSMacA = strncmp(a.path, "/System/iOSSupport/", 19) == 0;
2667 bool isIOSMacB = strncmp(b.path, "/System/iOSSupport/", 19) == 0;
2668 if (isIOSMacA != isIOSMacB)
2669 return !isIOSMacA;
2670 return strcmp(a.path, b.path) < 0;
2671 });
2672
2673 const dyld3::closure::ImageArray* otherImageArray = cb.makeOtherDylibsImageArray(others, (uint32_t)_sortedDylibs.size());
2674
2675 // build trie of paths
2676 __block std::vector<DylibIndexTrie::Entry> otherEntrys;
2677 otherImageArray->forEachImage(^(const dyld3::closure::Image* image, bool& stop) {
2678 if ( !image->isInvalid() )
2679 otherEntrys.push_back(DylibIndexTrie::Entry(image->path(), DylibIndex(image->imageNum())));
2680 });
2681 DylibIndexTrie dylibsTrie(otherEntrys);
2682 std::vector<uint8_t> trieBytes;
2683 dylibsTrie.emit(trieBytes);
2684 while ( (trieBytes.size() % 4) != 0 )
2685 trieBytes.push_back(0);
2686
2687 // check for fit
2688 uint64_t imageArraySize = otherImageArray->size();
2689 size_t freeSpace = _readOnlyRegion.bufferSize - _readOnlyRegion.sizeInUse;
2690 if ( imageArraySize+trieBytes.size() > freeSpace ) {
2691 _diagnostics.error("cache buffer too small to hold ImageArray and Trie (buffer size=%lldMB, imageArray size=%lldMB, trie size=%luKB, free space=%ldMB)",
2692 _allocatedBufferSize/1024/1024, imageArraySize/1024/1024, trieBytes.size()/1024, freeSpace/1024/1024);
2693 return;
2694 }
2695
2696 // copy into cache and update header
2697 DyldSharedCache* dyldCache = (DyldSharedCache*)_readExecuteRegion.buffer;
2698 dyldCache->header.otherImageArrayAddr = _readOnlyRegion.unslidLoadAddress + _readOnlyRegion.sizeInUse;
2699 dyldCache->header.otherImageArraySize = imageArraySize;
2700 dyldCache->header.otherTrieAddr = dyldCache->header.otherImageArrayAddr + imageArraySize;
2701 dyldCache->header.otherTrieSize = trieBytes.size();
2702 ::memcpy(_readOnlyRegion.buffer + _readOnlyRegion.sizeInUse, otherImageArray, imageArraySize);
2703 ::memcpy(_readOnlyRegion.buffer + _readOnlyRegion.sizeInUse + imageArraySize, &trieBytes[0], trieBytes.size());
2704 _readOnlyRegion.sizeInUse += align(imageArraySize+trieBytes.size(),14);
2705
2706 // Free the underlying buffer
2707 otherImageArray->deallocate();
2708 }
2709
2710
2711 void SharedCacheBuilder::addClosures(const std::vector<LoadedMachO>& osExecutables)
2712 {
2713 const DyldSharedCache* dyldCache = (DyldSharedCache*)_readExecuteRegion.buffer;
2714
2715 __block std::vector<Diagnostics> osExecutablesDiags;
2716 __block std::vector<const dyld3::closure::LaunchClosure*> osExecutablesClosures;
2717 osExecutablesDiags.resize(osExecutables.size());
2718 osExecutablesClosures.resize(osExecutables.size());
2719
2720 dispatch_apply(osExecutables.size(), DISPATCH_APPLY_AUTO, ^(size_t index) {
2721 const LoadedMachO& loadedMachO = osExecutables[index];
2722 // don't pre-build closures for staged apps into dyld cache, since they won't run from that location
2723 if ( startsWith(loadedMachO.mappedFile.runtimePath, "/private/var/staged_system_apps/") ) {
2724 return;
2725 }
2726
2727 // prebuilt closures use the cdhash of the dylib to verify that the dylib is still the same
2728 // at runtime as when the shared cache processed it. We must have a code signature to record this information
2729 uint32_t codeSigFileOffset;
2730 uint32_t codeSigSize;
2731 if ( !loadedMachO.mappedFile.mh->hasCodeSignature(codeSigFileOffset, codeSigSize) ) {
2732 return;
2733 }
2734
2735 dyld3::closure::PathOverrides pathOverrides;
2736 dyld3::RootsChecker rootsChecker;
2737 dyld3::closure::ClosureBuilder builder(dyld3::closure::kFirstLaunchClosureImageNum, _fileSystem, rootsChecker, dyldCache, false, *_options.archs, pathOverrides,
2738 dyld3::closure::ClosureBuilder::AtPath::all, false, nullptr, _options.platform, nullptr);
2739 bool issetuid = false;
2740 if ( this->_options.platform == dyld3::Platform::macOS || dyld3::MachOFile::isSimulatorPlatform(this->_options.platform) )
2741 _fileSystem.fileExists(loadedMachO.loadedFileInfo.path, nullptr, nullptr, &issetuid, nullptr);
2742 const dyld3::closure::LaunchClosure* mainClosure = builder.makeLaunchClosure(loadedMachO.loadedFileInfo, issetuid);
2743 if ( builder.diagnostics().hasError() ) {
2744 osExecutablesDiags[index].error("%s", builder.diagnostics().errorMessage().c_str());
2745 }
2746 else {
2747 assert(mainClosure != nullptr);
2748 osExecutablesClosures[index] = mainClosure;
2749 }
2750 });
2751
2752 std::map<std::string, const dyld3::closure::LaunchClosure*> closures;
2753 for (uint64_t i = 0, e = osExecutables.size(); i != e; ++i) {
2754 const LoadedMachO& loadedMachO = osExecutables[i];
2755 const Diagnostics& diag = osExecutablesDiags[i];
2756 if (diag.hasError()) {
2757 if ( _options.verbose ) {
2758 _diagnostics.warning("building closure for '%s': %s", loadedMachO.mappedFile.runtimePath.c_str(), diag.errorMessage().c_str());
2759 for (const std::string& warn : diag.warnings() )
2760 _diagnostics.warning("%s", warn.c_str());
2761 }
2762 if ( loadedMachO.inputFile && (loadedMachO.inputFile->mustBeIncluded()) ) {
2763 loadedMachO.inputFile->diag.error("%s", diag.errorMessage().c_str());
2764 }
2765 } else {
2766 // Note, a closure could be null here if it has a path we skip.
2767 if (osExecutablesClosures[i] != nullptr)
2768 closures[loadedMachO.mappedFile.runtimePath] = osExecutablesClosures[i];
2769 }
2770 }
2771
2772 osExecutablesDiags.clear();
2773 osExecutablesClosures.clear();
2774
2775 // preflight space needed
2776 size_t closuresSpace = 0;
2777 for (const auto& entry : closures) {
2778 closuresSpace += entry.second->size();
2779 }
2780 size_t freeSpace = _readOnlyRegion.bufferSize - _readOnlyRegion.sizeInUse;
2781 if ( closuresSpace > freeSpace ) {
2782 _diagnostics.error("cache buffer too small to hold all closures (buffer size=%lldMB, closures size=%ldMB, free space=%ldMB)",
2783 _allocatedBufferSize/1024/1024, closuresSpace/1024/1024, freeSpace/1024/1024);
2784 return;
2785 }
2786 DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
2787 cache->header.progClosuresAddr = _readOnlyRegion.unslidLoadAddress + _readOnlyRegion.sizeInUse;
2788 uint8_t* closuresBase = _readOnlyRegion.buffer + _readOnlyRegion.sizeInUse;
2789 std::vector<DylibIndexTrie::Entry> closureEntrys;
2790 uint32_t currentClosureOffset = 0;
2791 for (const auto& entry : closures) {
2792 const dyld3::closure::LaunchClosure* closure = entry.second;
2793 closureEntrys.push_back(DylibIndexTrie::Entry(entry.first, DylibIndex(currentClosureOffset)));
2794 size_t size = closure->size();
2795 assert((size % 4) == 0);
2796 memcpy(closuresBase+currentClosureOffset, closure, size);
2797 currentClosureOffset += size;
2798 freeSpace -= size;
2799 closure->deallocate();
2800 }
2801 cache->header.progClosuresSize = currentClosureOffset;
2802 _readOnlyRegion.sizeInUse += currentClosureOffset;
2803 freeSpace = _readOnlyRegion.bufferSize - _readOnlyRegion.sizeInUse;
2804 // build trie of indexes into closures list
2805 DylibIndexTrie closureTrie(closureEntrys);
2806 std::vector<uint8_t> trieBytes;
2807 closureTrie.emit(trieBytes);
2808 while ( (trieBytes.size() % 8) != 0 )
2809 trieBytes.push_back(0);
2810 if ( trieBytes.size() > freeSpace ) {
2811 _diagnostics.error("cache buffer too small to hold all closures trie (buffer size=%lldMB, trie size=%ldMB, free space=%ldMB)",
2812 _allocatedBufferSize/1024/1024, trieBytes.size()/1024/1024, freeSpace/1024/1024);
2813 return;
2814 }
2815 memcpy(_readOnlyRegion.buffer + _readOnlyRegion.sizeInUse, &trieBytes[0], trieBytes.size());
2816 cache->header.progClosuresTrieAddr = _readOnlyRegion.unslidLoadAddress + _readOnlyRegion.sizeInUse;
2817 cache->header.progClosuresTrieSize = trieBytes.size();
2818 _readOnlyRegion.sizeInUse += trieBytes.size();
2819 _readOnlyRegion.sizeInUse = align(_readOnlyRegion.sizeInUse, 14);
2820 }
2821
2822 void SharedCacheBuilder::emitContantObjects() {
2823 if ( _coalescedText.cfStrings.bufferSize == 0 )
2824 return;
2825
2826 assert(_coalescedText.cfStrings.isaInstallName != nullptr);
2827 DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
2828 __block uint64_t targetSymbolOffsetInCache = 0;
2829 __block const dyld3::MachOAnalyzer* targetSymbolMA = nullptr;
2830 __block const dyld3::MachOAnalyzer* libdyldMA = nullptr;
2831 cache->forEachImage(^(const mach_header* mh, const char* installName) {
2832 const dyld3::MachOAnalyzer* ma = (const dyld3::MachOAnalyzer*)mh;
2833
2834 if ( strcmp(installName, "/usr/lib/system/libdyld.dylib") == 0 ) {
2835 libdyldMA = ma;
2836 }
2837
2838 if ( targetSymbolOffsetInCache != 0 )
2839 return;
2840 if ( strcmp(installName, _coalescedText.cfStrings.isaInstallName) != 0 )
2841 return;
2842 dyld3::MachOAnalyzer::FoundSymbol foundInfo;
2843 bool foundSymbol = ma->findExportedSymbol(_diagnostics, _coalescedText.cfStrings.isaClassName,
2844 false, foundInfo, nullptr);
2845 if ( foundSymbol ) {
2846 targetSymbolOffsetInCache = (uint8_t*)ma - _readExecuteRegion.buffer + foundInfo.value;
2847 targetSymbolMA = ma;
2848 }
2849 });
2850 if ( targetSymbolOffsetInCache == 0 ) {
2851 _diagnostics.error("Could not find export of '%s' in '%s'", _coalescedText.cfStrings.isaClassName,
2852 _coalescedText.cfStrings.isaInstallName);
2853 return;
2854 }
2855 if ( libdyldMA == nullptr ) {
2856 _diagnostics.error("Could not libdyld.dylib in shared cache");
2857 return;
2858 }
2859
2860 // If all binds to this symbol were via CF constants, then we'll never have seen the ISA patch export
2861 // os add it now just in case
2862 _dylibToItsExports[targetSymbolMA].insert(targetSymbolOffsetInCache);
2863 _exportsToName[targetSymbolOffsetInCache] = _coalescedText.cfStrings.isaClassName;
2864
2865 // CFString's have so far just been memcpy'ed from the source dylib to the shared cache.
2866 // We now need to rewrite their ISAs to be rebases to the ___CFConstantStringClassReference class
2867 const uint64_t cfStringAtomSize = (uint64_t)DyldSharedCache::ConstantClasses::cfStringAtomSize;
2868 assert( (_coalescedText.cfStrings.bufferSize % cfStringAtomSize) == 0);
2869 for (uint64_t bufferOffset = 0; bufferOffset != _coalescedText.cfStrings.bufferSize; bufferOffset += cfStringAtomSize) {
2870 uint8_t* atomBuffer = _coalescedText.cfStrings.bufferAddr + bufferOffset;
2871 // The ISA fixup is at an offset of 0 in to the atom
2872 uint8_t* fixupLoc = atomBuffer;
2873 // We purposefully want to remove the pointer authentication from the ISA so
2874 // just use an empty pointer metadata
2875 dyld3::Loader::PointerMetaData pmd;
2876 uint64_t addend = 0;
2877 _exportsToUses[targetSymbolOffsetInCache].push_back(makePatchLocation(fixupLoc - _readExecuteRegion.buffer, pmd, addend));
2878 *(uint64_t*)fixupLoc = _archLayout->sharedMemoryStart + targetSymbolOffsetInCache;
2879 _aslrTracker.add(fixupLoc);
2880 }
2881
2882 // Set the ranges in the libdyld in the shared cache. At runtime we can use these to quickly check if a given address
2883 // is a valid constant
2884 typedef std::pair<const uint8_t*, const uint8_t*> ObjCConstantRange;
2885 std::pair<const void*, uint64_t> sharedCacheRanges = cache->getObjCConstantRange();
2886 uint64_t numRanges = sharedCacheRanges.second / sizeof(ObjCConstantRange);
2887 dyld3::Array<ObjCConstantRange> rangeArray((ObjCConstantRange*)sharedCacheRanges.first, numRanges, numRanges);
2888
2889 if ( numRanges > dyld_objc_string_kind ) {
2890 rangeArray[dyld_objc_string_kind].first = (const uint8_t*)_coalescedText.cfStrings.bufferVMAddr;
2891 rangeArray[dyld_objc_string_kind].second = rangeArray[dyld_objc_string_kind].first + _coalescedText.cfStrings.bufferSize;
2892 _aslrTracker.add(&rangeArray[dyld_objc_string_kind].first);
2893 _aslrTracker.add(&rangeArray[dyld_objc_string_kind].second);
2894 }
2895
2896 // Update the __SHARED_CACHE range in libdyld to contain the cf/objc constants
2897 libdyldMA->forEachLoadCommand(_diagnostics, ^(const load_command* cmd, bool& stop) {
2898 // We don't handle 32-bit as this is only needed for pointer authentication
2899 assert(cmd->cmd != LC_SEGMENT);
2900 if ( cmd->cmd == LC_SEGMENT_64 ) {
2901 segment_command_64* seg = (segment_command_64*)cmd;
2902 if ( strcmp(seg->segname, "__SHARED_CACHE") == 0 ) {
2903 // Update the range of this segment, and any sections inside
2904 seg->vmaddr = _coalescedText.cfStrings.bufferVMAddr;
2905 seg->vmsize = _coalescedText.cfStrings.bufferSize;
2906 seg->fileoff = _coalescedText.cfStrings.cacheFileOffset;
2907 seg->fileoff = _coalescedText.cfStrings.bufferSize;
2908 section_64* const sectionsStart = (section_64*)((char*)seg + sizeof(struct segment_command_64));
2909 section_64* const sectionsEnd = &sectionsStart[seg->nsects];
2910 for (section_64* sect=sectionsStart; sect < sectionsEnd; ++sect) {
2911 if ( !strcmp(sect->sectname, "__cfstring") ) {
2912 sect->addr = _coalescedText.cfStrings.bufferVMAddr;
2913 sect->size = _coalescedText.cfStrings.bufferSize;
2914 sect->offset = (uint32_t)_coalescedText.cfStrings.cacheFileOffset;
2915 }
2916 }
2917 stop = true;
2918 }
2919 }
2920 });
2921 }
2922
2923
2924 bool SharedCacheBuilder::writeCache(void (^cacheSizeCallback)(uint64_t size), bool (^copyCallback)(const uint8_t* src, uint64_t size, uint64_t dstOffset))
2925 {
2926 const dyld_cache_header* cacheHeader = (dyld_cache_header*)_readExecuteRegion.buffer;
2927 const dyld_cache_mapping_info* mappings = (dyld_cache_mapping_info*)(_readExecuteRegion.buffer + cacheHeader->mappingOffset);
2928 const uint32_t mappingsCount = cacheHeader->mappingCount;
2929 // Check the sizes of all the regions are correct
2930 assert(_readExecuteRegion.sizeInUse == mappings[0].size);
2931 for (uint32_t i = 0; i != _dataRegions.size(); ++i) {
2932 assert(_dataRegions[i].sizeInUse == mappings[i + 1].size);
2933 }
2934 assert(_readOnlyRegion.sizeInUse == mappings[mappingsCount - 1].size);
2935
2936 // Check the file offsets of all the regions are correct
2937 assert(_readExecuteRegion.cacheFileOffset == mappings[0].fileOffset);
2938 for (uint32_t i = 0; i != _dataRegions.size(); ++i) {
2939 assert(_dataRegions[i].cacheFileOffset == mappings[i + 1].fileOffset);
2940 }
2941 assert(_readOnlyRegion.cacheFileOffset == mappings[mappingsCount - 1].fileOffset);
2942 assert(_codeSignatureRegion.sizeInUse == cacheHeader->codeSignatureSize);
2943 assert(cacheHeader->codeSignatureOffset == _readOnlyRegion.cacheFileOffset+_readOnlyRegion.sizeInUse+_localSymbolsRegion.sizeInUse);
2944
2945 // Make sure the slidable mappings have the same ranges as the original mappings
2946 const dyld_cache_mapping_and_slide_info* slidableMappings = (dyld_cache_mapping_and_slide_info*)(_readExecuteRegion.buffer + cacheHeader->mappingWithSlideOffset);
2947 assert(cacheHeader->mappingCount == cacheHeader->mappingWithSlideCount);
2948 for (uint32_t i = 0; i != cacheHeader->mappingCount; ++i) {
2949 assert(mappings[i].address == slidableMappings[i].address);
2950 assert(mappings[i].size == slidableMappings[i].size);
2951 assert(mappings[i].fileOffset == slidableMappings[i].fileOffset);
2952 assert(mappings[i].maxProt == slidableMappings[i].maxProt);
2953 assert(mappings[i].initProt == slidableMappings[i].initProt);
2954 }
2955
2956 // Now that we know everything is correct, actually copy the data
2957 cacheSizeCallback(_readExecuteRegion.sizeInUse+dataRegionsSizeInUse()+_readOnlyRegion.sizeInUse+_localSymbolsRegion.sizeInUse+_codeSignatureRegion.sizeInUse);
2958 bool fullyWritten = copyCallback(_readExecuteRegion.buffer, _readExecuteRegion.sizeInUse, mappings[0].fileOffset);
2959 for (uint32_t i = 0; i != _dataRegions.size(); ++i) {
2960 fullyWritten &= copyCallback(_dataRegions[i].buffer, _dataRegions[i].sizeInUse, mappings[i + 1].fileOffset);
2961 }
2962 fullyWritten &= copyCallback(_readOnlyRegion.buffer, _readOnlyRegion.sizeInUse, mappings[cacheHeader->mappingCount - 1].fileOffset);
2963 if ( _localSymbolsRegion.sizeInUse != 0 ) {
2964 assert(cacheHeader->localSymbolsOffset == mappings[cacheHeader->mappingCount - 1].fileOffset+_readOnlyRegion.sizeInUse);
2965 fullyWritten &= copyCallback(_localSymbolsRegion.buffer, _localSymbolsRegion.sizeInUse, cacheHeader->localSymbolsOffset);
2966 }
2967 fullyWritten &= copyCallback(_codeSignatureRegion.buffer, _codeSignatureRegion.sizeInUse, cacheHeader->codeSignatureOffset);
2968 return fullyWritten;
2969 }
2970
2971
2972 void SharedCacheBuilder::writeFile(const std::string& path)
2973 {
2974 std::string pathTemplate = path + "-XXXXXX";
2975 size_t templateLen = strlen(pathTemplate.c_str())+2;
2976 BLOCK_ACCCESSIBLE_ARRAY(char, pathTemplateSpace, templateLen);
2977 strlcpy(pathTemplateSpace, pathTemplate.c_str(), templateLen);
2978 int fd = mkstemp(pathTemplateSpace);
2979 if ( fd != -1 ) {
2980 auto cacheSizeCallback = ^(uint64_t size) {
2981 // set final cache file size (may help defragment file)
2982 ::ftruncate(fd, size);
2983 };
2984 auto copyCallback = ^(const uint8_t* src, uint64_t size, uint64_t dstOffset) {
2985 uint64_t writtenSize = pwrite(fd, src, size, dstOffset);
2986 return writtenSize == size;
2987 };
2988 // <rdar://problem/55370916> TOCTOU: verify path is still a realpath (not changed)
2989 char tempPath[MAXPATHLEN];
2990 if ( ::fcntl(fd, F_GETPATH, tempPath) == 0 ) {
2991 size_t tempPathLen = strlen(tempPath);
2992 if ( tempPathLen > 7 )
2993 tempPath[tempPathLen-7] = '\0'; // remove trailing -xxxxxx
2994 if ( path != tempPath ) {
2995 _diagnostics.error("output file path changed from: '%s' to: '%s'", path.c_str(), tempPath);
2996 ::close(fd);
2997 return;
2998 }
2999 }
3000 else {
3001 _diagnostics.error("unable to fcntl(fd, F_GETPATH) on output file");
3002 ::close(fd);
3003 return;
3004 }
3005 bool fullyWritten = writeCache(cacheSizeCallback, copyCallback);
3006 if ( fullyWritten ) {
3007 ::fchmod(fd, S_IRUSR|S_IRGRP|S_IROTH); // mkstemp() makes file "rw-------", switch it to "r--r--r--"
3008 // <rdar://problem/55370916> TOCTOU: verify path is still a realpath (not changed)
3009 // For MRM bringup, dyld installs symlinks from:
3010 // dyld_shared_cache_x86_64 -> ../../../../System/Library/dyld/dyld_shared_cache_x86_64
3011 // dyld_shared_cache_x86_64h -> ../../../../System/Library/dyld/dyld_shared_cache_x86_64h
3012 // We don't want to follow that symlink when we install the cache, but instead write over it
3013 auto lastSlash = path.find_last_of("/");
3014 if ( lastSlash != std::string::npos ) {
3015 std::string directoryPath = path.substr(0, lastSlash);
3016
3017 char resolvedPath[PATH_MAX];
3018 ::realpath(directoryPath.c_str(), resolvedPath);
3019 // Note: if the target cache file does not already exist, realpath() will return NULL, but still fill in the path buffer
3020 if ( directoryPath != resolvedPath ) {
3021 _diagnostics.error("output directory file path changed from: '%s' to: '%s'", directoryPath.c_str(), resolvedPath);
3022 return;
3023 }
3024 }
3025 if ( ::rename(pathTemplateSpace, path.c_str()) == 0) {
3026 ::close(fd);
3027 return; // success
3028 } else {
3029 _diagnostics.error("could not rename file '%s' to: '%s'", pathTemplateSpace, path.c_str());
3030 }
3031 }
3032 else {
3033 _diagnostics.error("could not write file %s", pathTemplateSpace);
3034 }
3035 ::close(fd);
3036 ::unlink(pathTemplateSpace);
3037 }
3038 else {
3039 _diagnostics.error("could not open file %s", pathTemplateSpace);
3040 }
3041 }
3042
3043 void SharedCacheBuilder::writeBuffer(uint8_t*& buffer, uint64_t& bufferSize) {
3044 auto cacheSizeCallback = ^(uint64_t size) {
3045 buffer = (uint8_t*)malloc(size);
3046 bufferSize = size;
3047 };
3048 auto copyCallback = ^(const uint8_t* src, uint64_t size, uint64_t dstOffset) {
3049 memcpy(buffer + dstOffset, src, size);
3050 return true;
3051 };
3052 bool fullyWritten = writeCache(cacheSizeCallback, copyCallback);
3053 assert(fullyWritten);
3054 }
3055
3056 void SharedCacheBuilder::writeMapFile(const std::string& path)
3057 {
3058 std::string mapContent = getMapFileBuffer();
3059 safeSave(mapContent.c_str(), mapContent.size(), path);
3060 }
3061
3062 std::string SharedCacheBuilder::getMapFileBuffer() const
3063 {
3064 const DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
3065 return cache->mapFile();
3066 }
3067
3068 std::string SharedCacheBuilder::getMapFileJSONBuffer(const std::string& cacheDisposition) const
3069 {
3070 const DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
3071 return cache->generateJSONMap(cacheDisposition.c_str());
3072 }
3073
3074 void SharedCacheBuilder::markPaddingInaccessible()
3075 {
3076 // region between RX and RW
3077 uint8_t* startPad1 = _readExecuteRegion.buffer+_readExecuteRegion.sizeInUse;
3078 uint8_t* endPad1 = firstDataRegion()->buffer;
3079 ::vm_protect(mach_task_self(), (vm_address_t)startPad1, endPad1-startPad1, false, 0);
3080
3081 // region between RW and RO
3082 const Region* lastRegion = lastDataRegion();
3083 uint8_t* startPad2 = lastRegion->buffer+lastRegion->sizeInUse;
3084 uint8_t* endPad2 = _readOnlyRegion.buffer;
3085 ::vm_protect(mach_task_self(), (vm_address_t)startPad2, endPad2-startPad2, false, 0);
3086 }
3087
3088
3089 void SharedCacheBuilder::forEachCacheDylib(void (^callback)(const std::string& path)) {
3090 for (const DylibInfo& dylibInfo : _sortedDylibs)
3091 callback(dylibInfo.dylibID);
3092 }
3093
3094
3095 void SharedCacheBuilder::forEachCacheSymlink(void (^callback)(const std::string& path))
3096 {
3097 const DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
3098 const dyld3::closure::ImageArray* images = cache->cachedDylibsImageArray();
3099 if ( images == nullptr )
3100 return;
3101
3102 // Aliases we folded in to the cache are in the cache dylib closures
3103 images->forEachImage(^(const dyld3::closure::Image *image, bool &stop) {
3104 image->forEachAlias(^(const char *aliasPath, bool &stop) {
3105 callback(aliasPath);
3106 });
3107 });
3108 }
3109
3110
3111 uint64_t SharedCacheBuilder::pathHash(const char* path)
3112 {
3113 uint64_t sum = 0;
3114 for (const char* s=path; *s != '\0'; ++s)
3115 sum += sum*4 + *s;
3116 return sum;
3117 }
3118
3119
3120 void SharedCacheBuilder::findDylibAndSegment(const void* contentPtr, std::string& foundDylibName, std::string& foundSegName)
3121 {
3122 foundDylibName = "???";
3123 foundSegName = "???";
3124 uint64_t unslidVmAddr = ((uint8_t*)contentPtr - _readExecuteRegion.buffer) + _readExecuteRegion.unslidLoadAddress;
3125 const DyldSharedCache* cache = (DyldSharedCache*)_readExecuteRegion.buffer;
3126 cache->forEachImage(^(const mach_header* mh, const char* installName) {
3127 ((dyld3::MachOLoaded*)mh)->forEachSegment(^(const dyld3::MachOFile::SegmentInfo& info, bool &stop) {
3128 if ( (unslidVmAddr >= info.vmAddr) && (unslidVmAddr < (info.vmAddr+info.vmSize)) ) {
3129 foundDylibName = installName;
3130 foundSegName = info.segName;
3131 stop = true;
3132 }
3133 });
3134 });
3135 }
3136
3137
3138 void SharedCacheBuilder::fipsSign()
3139 {
3140 // find libcorecrypto.dylib in cache being built
3141 DyldSharedCache* dyldCache = (DyldSharedCache*)_readExecuteRegion.buffer;
3142 __block const dyld3::MachOLoaded* ml = nullptr;
3143 dyldCache->forEachImage(^(const mach_header* mh, const char* installName) {
3144 if ( strcmp(installName, "/usr/lib/system/libcorecrypto.dylib") == 0 )
3145 ml = (dyld3::MachOLoaded*)mh;
3146 });
3147 if ( ml == nullptr ) {
3148 _diagnostics.warning("Could not find libcorecrypto.dylib, skipping FIPS sealing");
3149 return;
3150 }
3151
3152 // find location in libcorecrypto.dylib to store hash of __text section
3153 uint64_t hashStoreSize;
3154 const void* hashStoreLocation = ml->findSectionContent("__TEXT", "__fips_hmacs", hashStoreSize);
3155 if ( hashStoreLocation == nullptr ) {
3156 _diagnostics.warning("Could not find __TEXT/__fips_hmacs section in libcorecrypto.dylib, skipping FIPS sealing");
3157 return;
3158 }
3159 if ( hashStoreSize != 32 ) {
3160 _diagnostics.warning("__TEXT/__fips_hmacs section in libcorecrypto.dylib is not 32 bytes in size, skipping FIPS sealing");
3161 return;
3162 }
3163
3164 // compute hmac hash of __text section
3165 uint64_t textSize;
3166 const void* textLocation = ml->findSectionContent("__TEXT", "__text", textSize);
3167 if ( textLocation == nullptr ) {
3168 _diagnostics.warning("Could not find __TEXT/__text section in libcorecrypto.dylib, skipping FIPS sealing");
3169 return;
3170 }
3171 unsigned char hmac_key = 0;
3172 CCHmac(kCCHmacAlgSHA256, &hmac_key, 1, textLocation, textSize, (void*)hashStoreLocation); // store hash directly into hashStoreLocation
3173 }
3174
3175 void SharedCacheBuilder::codeSign()
3176 {
3177 uint8_t dscHashType;
3178 uint8_t dscHashSize;
3179 uint32_t dscDigestFormat;
3180 bool agile = false;
3181
3182 // select which codesigning hash
3183 switch (_options.codeSigningDigestMode) {
3184 case DyldSharedCache::Agile:
3185 agile = true;
3186 // Fall through to SHA1, because the main code directory remains SHA1 for compatibility.
3187 [[clang::fallthrough]];
3188 case DyldSharedCache::SHA1only:
3189 #pragma clang diagnostic push
3190 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
3191 dscHashType = CS_HASHTYPE_SHA1;
3192 dscHashSize = CS_HASH_SIZE_SHA1;
3193 dscDigestFormat = kCCDigestSHA1;
3194 #pragma clang diagnostic pop
3195 break;
3196 case DyldSharedCache::SHA256only:
3197 dscHashType = CS_HASHTYPE_SHA256;
3198 dscHashSize = CS_HASH_SIZE_SHA256;
3199 dscDigestFormat = kCCDigestSHA256;
3200 break;
3201 default:
3202 _diagnostics.error("codeSigningDigestMode has unknown, unexpected value %d, bailing out.",
3203 _options.codeSigningDigestMode);
3204 return;
3205 }
3206
3207 std::string cacheIdentifier = "com.apple.dyld.cache.";
3208 cacheIdentifier += _options.archs->name();
3209 if ( _options.dylibsRemovedDuringMastering ) {
3210 if ( _options.optimizeStubs )
3211 cacheIdentifier += ".release";
3212 else
3213 cacheIdentifier += ".development";
3214 }
3215 // get pointers into shared cache buffer
3216 size_t inBbufferSize = _readExecuteRegion.sizeInUse+dataRegionsSizeInUse()+_readOnlyRegion.sizeInUse+_localSymbolsRegion.sizeInUse;
3217
3218 const uint16_t pageSize = _archLayout->csPageSize;
3219
3220 // layout code signature contents
3221 uint32_t blobCount = agile ? 4 : 3;
3222 size_t idSize = cacheIdentifier.size()+1; // +1 for terminating 0
3223 uint32_t slotCount = (uint32_t)((inBbufferSize + pageSize - 1) / pageSize);
3224 uint32_t xSlotCount = CSSLOT_REQUIREMENTS;
3225 size_t idOffset = offsetof(CS_CodeDirectory, end_withExecSeg);
3226 size_t hashOffset = idOffset+idSize + dscHashSize*xSlotCount;
3227 size_t hash256Offset = idOffset+idSize + CS_HASH_SIZE_SHA256*xSlotCount;
3228 size_t cdSize = hashOffset + (slotCount * dscHashSize);
3229 size_t cd256Size = agile ? hash256Offset + (slotCount * CS_HASH_SIZE_SHA256) : 0;
3230 size_t reqsSize = 12;
3231 size_t cmsSize = sizeof(CS_Blob);
3232 size_t cdOffset = sizeof(CS_SuperBlob) + blobCount*sizeof(CS_BlobIndex);
3233 size_t cd256Offset = cdOffset + cdSize;
3234 size_t reqsOffset = cd256Offset + cd256Size; // equals cdOffset + cdSize if not agile
3235 size_t cmsOffset = reqsOffset + reqsSize;
3236 size_t sbSize = cmsOffset + cmsSize;
3237 size_t sigSize = align(sbSize, 14); // keep whole cache 16KB aligned
3238
3239 // allocate space for blob
3240 vm_address_t codeSigAlloc;
3241 if ( vm_allocate(mach_task_self(), &codeSigAlloc, sigSize, VM_FLAGS_ANYWHERE) != 0 ) {
3242 _diagnostics.error("could not allocate code signature buffer");
3243 return;
3244 }
3245 _codeSignatureRegion.buffer = (uint8_t*)codeSigAlloc;
3246 _codeSignatureRegion.bufferSize = sigSize;
3247 _codeSignatureRegion.sizeInUse = sigSize;
3248
3249 // create overall code signature which is a superblob
3250 CS_SuperBlob* sb = reinterpret_cast<CS_SuperBlob*>(_codeSignatureRegion.buffer);
3251 sb->magic = htonl(CSMAGIC_EMBEDDED_SIGNATURE);
3252 sb->length = htonl(sbSize);
3253 sb->count = htonl(blobCount);
3254 sb->index[0].type = htonl(CSSLOT_CODEDIRECTORY);
3255 sb->index[0].offset = htonl(cdOffset);
3256 sb->index[1].type = htonl(CSSLOT_REQUIREMENTS);
3257 sb->index[1].offset = htonl(reqsOffset);
3258 sb->index[2].type = htonl(CSSLOT_CMS_SIGNATURE);
3259 sb->index[2].offset = htonl(cmsOffset);
3260 if ( agile ) {
3261 sb->index[3].type = htonl(CSSLOT_ALTERNATE_CODEDIRECTORIES + 0);
3262 sb->index[3].offset = htonl(cd256Offset);
3263 }
3264
3265 // fill in empty requirements
3266 CS_RequirementsBlob* reqs = (CS_RequirementsBlob*)(((char*)sb)+reqsOffset);
3267 reqs->magic = htonl(CSMAGIC_REQUIREMENTS);
3268 reqs->length = htonl(sizeof(CS_RequirementsBlob));
3269 reqs->data = 0;
3270
3271 // initialize fixed fields of Code Directory
3272 CS_CodeDirectory* cd = (CS_CodeDirectory*)(((char*)sb)+cdOffset);
3273 cd->magic = htonl(CSMAGIC_CODEDIRECTORY);
3274 cd->length = htonl(cdSize);
3275 cd->version = htonl(0x20400); // supports exec segment
3276 cd->flags = htonl(kSecCodeSignatureAdhoc);
3277 cd->hashOffset = htonl(hashOffset);
3278 cd->identOffset = htonl(idOffset);
3279 cd->nSpecialSlots = htonl(xSlotCount);
3280 cd->nCodeSlots = htonl(slotCount);
3281 cd->codeLimit = htonl(inBbufferSize);
3282 cd->hashSize = dscHashSize;
3283 cd->hashType = dscHashType;
3284 cd->platform = 0; // not platform binary
3285 cd->pageSize = __builtin_ctz(pageSize); // log2(CS_PAGE_SIZE);
3286 cd->spare2 = 0; // unused (must be zero)
3287 cd->scatterOffset = 0; // not supported anymore
3288 cd->teamOffset = 0; // no team ID
3289 cd->spare3 = 0; // unused (must be zero)
3290 cd->codeLimit64 = 0; // falls back to codeLimit
3291
3292 // executable segment info
3293 cd->execSegBase = htonll(_readExecuteRegion.cacheFileOffset); // base of TEXT segment
3294 cd->execSegLimit = htonll(_readExecuteRegion.sizeInUse); // size of TEXT segment
3295 cd->execSegFlags = 0; // not a main binary
3296
3297 // initialize dynamic fields of Code Directory
3298 strcpy((char*)cd + idOffset, cacheIdentifier.c_str());
3299
3300 // add special slot hashes
3301 uint8_t* hashSlot = (uint8_t*)cd + hashOffset;
3302 uint8_t* reqsHashSlot = &hashSlot[-CSSLOT_REQUIREMENTS*dscHashSize];
3303 CCDigest(dscDigestFormat, (uint8_t*)reqs, sizeof(CS_RequirementsBlob), reqsHashSlot);
3304
3305 CS_CodeDirectory* cd256;
3306 uint8_t* hash256Slot;
3307 uint8_t* reqsHash256Slot;
3308 if ( agile ) {
3309 // Note that the assumption here is that the size up to the hashes is the same as for
3310 // sha1 code directory, and that they come last, after everything else.
3311
3312 cd256 = (CS_CodeDirectory*)(((char*)sb)+cd256Offset);
3313 cd256->magic = htonl(CSMAGIC_CODEDIRECTORY);
3314 cd256->length = htonl(cd256Size);
3315 cd256->version = htonl(0x20400); // supports exec segment
3316 cd256->flags = htonl(kSecCodeSignatureAdhoc);
3317 cd256->hashOffset = htonl(hash256Offset);
3318 cd256->identOffset = htonl(idOffset);
3319 cd256->nSpecialSlots = htonl(xSlotCount);
3320 cd256->nCodeSlots = htonl(slotCount);
3321 cd256->codeLimit = htonl(inBbufferSize);
3322 cd256->hashSize = CS_HASH_SIZE_SHA256;
3323 cd256->hashType = CS_HASHTYPE_SHA256;
3324 cd256->platform = 0; // not platform binary
3325 cd256->pageSize = __builtin_ctz(pageSize); // log2(CS_PAGE_SIZE);
3326 cd256->spare2 = 0; // unused (must be zero)
3327 cd256->scatterOffset = 0; // not supported anymore
3328 cd256->teamOffset = 0; // no team ID
3329 cd256->spare3 = 0; // unused (must be zero)
3330 cd256->codeLimit64 = 0; // falls back to codeLimit
3331
3332 // executable segment info
3333 cd256->execSegBase = cd->execSegBase;
3334 cd256->execSegLimit = cd->execSegLimit;
3335 cd256->execSegFlags = cd->execSegFlags;
3336
3337 // initialize dynamic fields of Code Directory
3338 strcpy((char*)cd256 + idOffset, cacheIdentifier.c_str());
3339
3340 // add special slot hashes
3341 hash256Slot = (uint8_t*)cd256 + hash256Offset;
3342 reqsHash256Slot = &hash256Slot[-CSSLOT_REQUIREMENTS*CS_HASH_SIZE_SHA256];
3343 CCDigest(kCCDigestSHA256, (uint8_t*)reqs, sizeof(CS_RequirementsBlob), reqsHash256Slot);
3344 }
3345 else {
3346 cd256 = NULL;
3347 hash256Slot = NULL;
3348 reqsHash256Slot = NULL;
3349 }
3350
3351 // fill in empty CMS blob for ad-hoc signing
3352 CS_Blob* cms = (CS_Blob*)(((char*)sb)+cmsOffset);
3353 cms->magic = htonl(CSMAGIC_BLOBWRAPPER);
3354 cms->length = htonl(sizeof(CS_Blob));
3355
3356
3357 // alter header of cache to record size and location of code signature
3358 // do this *before* hashing each page
3359 dyld_cache_header* cache = (dyld_cache_header*)_readExecuteRegion.buffer;
3360 cache->codeSignatureOffset = inBbufferSize;
3361 cache->codeSignatureSize = sigSize;
3362
3363 struct SlotRange {
3364 uint64_t start = 0;
3365 uint64_t end = 0;
3366 const uint8_t* buffer = nullptr;
3367 };
3368 std::vector<SlotRange> regionSlots;
3369 // __TEXT
3370 regionSlots.push_back({ 0, (_readExecuteRegion.sizeInUse / pageSize), _readExecuteRegion.buffer });
3371 // __DATA
3372 for (const Region& dataRegion : _dataRegions) {
3373 // The first data region starts at the end of __TEXT, and subsequent regions are
3374 // after the previous __DATA region.
3375 uint64_t previousEnd = regionSlots.back().end;
3376 uint64_t numSlots = dataRegion.sizeInUse / pageSize;
3377 regionSlots.push_back({ previousEnd, previousEnd + numSlots, dataRegion.buffer });
3378 }
3379 // __LINKEDIT
3380 {
3381 uint64_t previousEnd = regionSlots.back().end;
3382 uint64_t numSlots = _readOnlyRegion.sizeInUse / pageSize;
3383 regionSlots.push_back({ previousEnd, previousEnd + numSlots, _readOnlyRegion.buffer });
3384 }
3385 // local symbols
3386 if ( _localSymbolsRegion.sizeInUse != 0 ) {
3387 uint64_t previousEnd = regionSlots.back().end;
3388 uint64_t numSlots = _localSymbolsRegion.sizeInUse / pageSize;
3389 regionSlots.push_back({ previousEnd, previousEnd + numSlots, _localSymbolsRegion.buffer });
3390 }
3391
3392 auto codeSignPage = ^(size_t i) {
3393 // move to correct region
3394 for (const SlotRange& slotRange : regionSlots) {
3395 if ( (i >= slotRange.start) && (i < slotRange.end) ) {
3396 const uint8_t* code = slotRange.buffer + ((i - slotRange.start) * pageSize);
3397
3398 CCDigest(dscDigestFormat, code, pageSize, hashSlot + (i * dscHashSize));
3399
3400 if ( agile ) {
3401 CCDigest(kCCDigestSHA256, code, pageSize, hash256Slot + (i * CS_HASH_SIZE_SHA256));
3402 }
3403 return;
3404 }
3405 }
3406 assert(0 && "Out of range slot");
3407 };
3408
3409 // compute hashes
3410 dispatch_apply(slotCount, DISPATCH_APPLY_AUTO, ^(size_t i) {
3411 codeSignPage(i);
3412 });
3413
3414 // Now that we have a code signature, compute a cache UUID by hashing the code signature blob
3415 {
3416 uint8_t* uuidLoc = cache->uuid;
3417 assert(uuid_is_null(uuidLoc));
3418 static_assert(offsetof(dyld_cache_header, uuid) / CS_PAGE_SIZE_4K == 0, "uuid is expected in the first page of the cache");
3419 uint8_t fullDigest[CC_SHA256_DIGEST_LENGTH];
3420 CC_SHA256((const void*)cd, (unsigned)cdSize, fullDigest);
3421 memcpy(uuidLoc, fullDigest, 16);
3422 // <rdar://problem/6723729> uuids should conform to RFC 4122 UUID version 4 & UUID version 5 formats
3423 uuidLoc[6] = ( uuidLoc[6] & 0x0F ) | ( 3 << 4 );
3424 uuidLoc[8] = ( uuidLoc[8] & 0x3F ) | 0x80;
3425
3426 // Now codesign page 0 again, because we modified it by setting uuid in header
3427 codeSignPage(0);
3428 }
3429
3430 // hash of entire code directory (cdHash) uses same hash as each page
3431 uint8_t fullCdHash[dscHashSize];
3432 CCDigest(dscDigestFormat, (const uint8_t*)cd, cdSize, fullCdHash);
3433 // Note: cdHash is defined as first 20 bytes of hash
3434 memcpy(_cdHashFirst, fullCdHash, 20);
3435 if ( agile ) {
3436 uint8_t fullCdHash256[CS_HASH_SIZE_SHA256];
3437 CCDigest(kCCDigestSHA256, (const uint8_t*)cd256, cd256Size, fullCdHash256);
3438 // Note: cdHash is defined as first 20 bytes of hash, even for sha256
3439 memcpy(_cdHashSecond, fullCdHash256, 20);
3440 }
3441 else {
3442 memset(_cdHashSecond, 0, 20);
3443 }
3444 }
3445
3446 const bool SharedCacheBuilder::agileSignature()
3447 {
3448 return _options.codeSigningDigestMode == DyldSharedCache::Agile;
3449 }
3450
3451 static const std::string cdHash(uint8_t hash[20])
3452 {
3453 char buff[48];
3454 for (int i = 0; i < 20; ++i)
3455 sprintf(&buff[2*i], "%2.2x", hash[i]);
3456 return buff;
3457 }
3458
3459 const std::string SharedCacheBuilder::cdHashFirst()
3460 {
3461 return cdHash(_cdHashFirst);
3462 }
3463
3464 const std::string SharedCacheBuilder::cdHashSecond()
3465 {
3466 return cdHash(_cdHashSecond);
3467 }
3468
3469 const std::string SharedCacheBuilder::uuid() const
3470 {
3471 dyld_cache_header* cache = (dyld_cache_header*)_readExecuteRegion.buffer;
3472 uuid_string_t uuidStr;
3473 uuid_unparse(cache->uuid, uuidStr);
3474 return uuidStr;
3475 }
3476
3477 void SharedCacheBuilder::forEachDylibInfo(void (^callback)(const DylibInfo& dylib, Diagnostics& dylibDiag)) {
3478 for (const DylibInfo& dylibInfo : _sortedDylibs) {
3479 // The shared cache builder doesn't use per-dylib errors right now
3480 // so just share the global diagnostics
3481 callback(dylibInfo, _diagnostics);
3482 }
3483 }
3484
3485
3486
3487 template <typename P>
3488 bool SharedCacheBuilder::makeRebaseChainV2(uint8_t* pageContent, uint16_t lastLocationOffset, uint16_t offset, const dyld_cache_slide_info2* info)
3489 {
3490 typedef typename P::uint_t pint_t;
3491
3492 const pint_t deltaMask = (pint_t)(info->delta_mask);
3493 const pint_t valueMask = ~deltaMask;
3494 const pint_t valueAdd = (pint_t)(info->value_add);
3495 const unsigned deltaShift = __builtin_ctzll(deltaMask) - 2;
3496 const uint32_t maxDelta = (uint32_t)(deltaMask >> deltaShift);
3497
3498 pint_t* lastLoc = (pint_t*)&pageContent[lastLocationOffset+0];
3499 pint_t lastValue = (pint_t)P::getP(*lastLoc);
3500 if ( (lastValue - valueAdd) & deltaMask ) {
3501 std::string dylibName;
3502 std::string segName;
3503 findDylibAndSegment((void*)pageContent, dylibName, segName);
3504 _diagnostics.error("rebase pointer (0x%0lX) does not point within cache. lastOffset=0x%04X, seg=%s, dylib=%s\n",
3505 (long)lastValue, lastLocationOffset, segName.c_str(), dylibName.c_str());
3506 return false;
3507 }
3508 if ( offset <= (lastLocationOffset+maxDelta) ) {
3509 // previous location in range, make link from it
3510 // encode this location into last value
3511 pint_t delta = offset - lastLocationOffset;
3512 pint_t newLastValue = ((lastValue - valueAdd) & valueMask) | (delta << deltaShift);
3513 //warning(" add chain: delta = %d, lastOffset=0x%03X, offset=0x%03X, org value=0x%08lX, new value=0x%08lX",
3514 // offset - lastLocationOffset, lastLocationOffset, offset, (long)lastValue, (long)newLastValue);
3515 uint8_t highByte;
3516 if ( _aslrTracker.hasHigh8(lastLoc, &highByte) ) {
3517 uint64_t tbi = (uint64_t)highByte << 56;
3518 newLastValue |= tbi;
3519 }
3520 P::setP(*lastLoc, newLastValue);
3521 return true;
3522 }
3523 //fprintf(stderr, " too big delta = %d, lastOffset=0x%03X, offset=0x%03X\n", offset - lastLocationOffset, lastLocationOffset, offset);
3524
3525 // distance between rebase locations is too far
3526 // see if we can make a chain from non-rebase locations
3527 uint16_t nonRebaseLocationOffsets[1024];
3528 unsigned nrIndex = 0;
3529 for (uint16_t i = lastLocationOffset; i < offset-maxDelta; ) {
3530 nonRebaseLocationOffsets[nrIndex] = 0;
3531 for (int j=maxDelta; j > 0; j -= 4) {
3532 pint_t value = (pint_t)P::getP(*(pint_t*)&pageContent[i+j]);
3533 if ( value == 0 ) {
3534 // Steal values of 0 to be used in the rebase chain
3535 nonRebaseLocationOffsets[nrIndex] = i+j;
3536 break;
3537 }
3538 }
3539 if ( nonRebaseLocationOffsets[nrIndex] == 0 ) {
3540 lastValue = (pint_t)P::getP(*lastLoc);
3541 pint_t newValue = ((lastValue - valueAdd) & valueMask);
3542 //warning(" no way to make non-rebase delta chain, terminate off=0x%03X, old value=0x%08lX, new value=0x%08lX", lastLocationOffset, (long)value, (long)newValue);
3543 P::setP(*lastLoc, newValue);
3544 return false;
3545 }
3546 i = nonRebaseLocationOffsets[nrIndex];
3547 ++nrIndex;
3548 }
3549
3550 // we can make chain. go back and add each non-rebase location to chain
3551 uint16_t prevOffset = lastLocationOffset;
3552 pint_t* prevLoc = (pint_t*)&pageContent[prevOffset];
3553 for (unsigned n=0; n < nrIndex; ++n) {
3554 uint16_t nOffset = nonRebaseLocationOffsets[n];
3555 assert(nOffset != 0);
3556 pint_t* nLoc = (pint_t*)&pageContent[nOffset];
3557 pint_t delta2 = nOffset - prevOffset;
3558 pint_t value = (pint_t)P::getP(*prevLoc);
3559 pint_t newValue;
3560 if ( value == 0 )
3561 newValue = (delta2 << deltaShift);
3562 else
3563 newValue = ((value - valueAdd) & valueMask) | (delta2 << deltaShift);
3564 //warning(" non-rebase delta = %d, to off=0x%03X, old value=0x%08lX, new value=0x%08lX", delta2, nOffset, (long)value, (long)newValue);
3565 P::setP(*prevLoc, newValue);
3566 prevOffset = nOffset;
3567 prevLoc = nLoc;
3568 }
3569 pint_t delta3 = offset - prevOffset;
3570 pint_t value = (pint_t)P::getP(*prevLoc);
3571 pint_t newValue;
3572 if ( value == 0 )
3573 newValue = (delta3 << deltaShift);
3574 else
3575 newValue = ((value - valueAdd) & valueMask) | (delta3 << deltaShift);
3576 //warning(" non-rebase delta = %d, to off=0x%03X, old value=0x%08lX, new value=0x%08lX", delta3, offset, (long)value, (long)newValue);
3577 P::setP(*prevLoc, newValue);
3578
3579 return true;
3580 }
3581
3582
3583 template <typename P>
3584 void SharedCacheBuilder::addPageStartsV2(uint8_t* pageContent, const bool bitmap[], const dyld_cache_slide_info2* info,
3585 std::vector<uint16_t>& pageStarts, std::vector<uint16_t>& pageExtras)
3586 {
3587 typedef typename P::uint_t pint_t;
3588
3589 const pint_t deltaMask = (pint_t)(info->delta_mask);
3590 const pint_t valueMask = ~deltaMask;
3591 const uint32_t pageSize = info->page_size;
3592 const pint_t valueAdd = (pint_t)(info->value_add);
3593
3594 uint16_t startValue = DYLD_CACHE_SLIDE_PAGE_ATTR_NO_REBASE;
3595 uint16_t lastLocationOffset = 0xFFFF;
3596 for(uint32_t i=0; i < pageSize/4; ++i) {
3597 unsigned offset = i*4;
3598 if ( bitmap[i] ) {
3599 if ( startValue == DYLD_CACHE_SLIDE_PAGE_ATTR_NO_REBASE ) {
3600 // found first rebase location in page
3601 startValue = i;
3602 }
3603 else if ( !makeRebaseChainV2<P>(pageContent, lastLocationOffset, offset, info) ) {
3604 // can't record all rebasings in one chain
3605 if ( (startValue & DYLD_CACHE_SLIDE_PAGE_ATTR_EXTRA) == 0 ) {
3606 // switch page_start to "extras" which is a list of chain starts
3607 unsigned indexInExtras = (unsigned)pageExtras.size();
3608 if ( indexInExtras > 0x3FFF ) {
3609 _diagnostics.error("rebase overflow in v2 page extras");
3610 return;
3611 }
3612 pageExtras.push_back(startValue);
3613 startValue = indexInExtras | DYLD_CACHE_SLIDE_PAGE_ATTR_EXTRA;
3614 }
3615 pageExtras.push_back(i);
3616 }
3617 lastLocationOffset = offset;
3618 }
3619 }
3620 if ( lastLocationOffset != 0xFFFF ) {
3621 // mark end of chain
3622 pint_t* lastLoc = (pint_t*)&pageContent[lastLocationOffset];
3623 pint_t lastValue = (pint_t)P::getP(*lastLoc);
3624 pint_t newValue = ((lastValue - valueAdd) & valueMask);
3625 P::setP(*lastLoc, newValue);
3626 }
3627 if ( startValue & DYLD_CACHE_SLIDE_PAGE_ATTR_EXTRA ) {
3628 // add end bit to extras
3629 pageExtras.back() |= DYLD_CACHE_SLIDE_PAGE_ATTR_END;
3630 }
3631 pageStarts.push_back(startValue);
3632 }
3633
3634 template <typename P>
3635 void SharedCacheBuilder::writeSlideInfoV2(const bool bitmapForAllDataRegions[], unsigned dataPageCountForAllDataRegions)
3636 {
3637 typedef typename P::uint_t pint_t;
3638 typedef typename P::E E;
3639
3640 const uint32_t pageSize = _aslrTracker.pageSize();
3641 const uint8_t* firstDataRegionBuffer = firstDataRegion()->buffer;
3642 for (uint32_t dataRegionIndex = 0; dataRegionIndex != _dataRegions.size(); ++dataRegionIndex) {
3643 Region& dataRegion = _dataRegions[dataRegionIndex];
3644
3645 // fill in fixed info
3646 assert(dataRegion.slideInfoFileOffset != 0);
3647 assert((dataRegion.sizeInUse % pageSize) == 0);
3648 unsigned dataPageCount = (uint32_t)dataRegion.sizeInUse / pageSize;
3649 dyld_cache_slide_info2* info = (dyld_cache_slide_info2*)dataRegion.slideInfoBuffer;
3650 info->version = 2;
3651 info->page_size = pageSize;
3652 info->delta_mask = _archLayout->pointerDeltaMask;
3653 info->value_add = _archLayout->useValueAdd ? _archLayout->sharedMemoryStart : 0;
3654
3655 // set page starts and extras for each page
3656 std::vector<uint16_t> pageStarts;
3657 std::vector<uint16_t> pageExtras;
3658 pageStarts.reserve(dataPageCount);
3659
3660 const size_t bitmapEntriesPerPage = (sizeof(bool)*(pageSize/4));
3661 uint8_t* pageContent = dataRegion.buffer;
3662 unsigned numPagesFromFirstDataRegion = (uint32_t)(dataRegion.buffer - firstDataRegionBuffer) / pageSize;
3663 assert((numPagesFromFirstDataRegion + dataPageCount) <= dataPageCountForAllDataRegions);
3664 const bool* bitmapForRegion = (const bool*)bitmapForAllDataRegions + (bitmapEntriesPerPage * numPagesFromFirstDataRegion);
3665 const bool* bitmapForPage = bitmapForRegion;
3666 for (unsigned i=0; i < dataPageCount; ++i) {
3667 //warning("page[%d]", i);
3668 addPageStartsV2<P>(pageContent, bitmapForPage, info, pageStarts, pageExtras);
3669 if ( _diagnostics.hasError() ) {
3670 return;
3671 }
3672 pageContent += pageSize;
3673 bitmapForPage += (sizeof(bool)*(pageSize/4));
3674 }
3675
3676 // fill in computed info
3677 info->page_starts_offset = sizeof(dyld_cache_slide_info2);
3678 info->page_starts_count = (unsigned)pageStarts.size();
3679 info->page_extras_offset = (unsigned)(sizeof(dyld_cache_slide_info2)+pageStarts.size()*sizeof(uint16_t));
3680 info->page_extras_count = (unsigned)pageExtras.size();
3681 uint16_t* pageStartsBuffer = (uint16_t*)((char*)info + info->page_starts_offset);
3682 uint16_t* pageExtrasBuffer = (uint16_t*)((char*)info + info->page_extras_offset);
3683 for (unsigned i=0; i < pageStarts.size(); ++i)
3684 pageStartsBuffer[i] = pageStarts[i];
3685 for (unsigned i=0; i < pageExtras.size(); ++i)
3686 pageExtrasBuffer[i] = pageExtras[i];
3687 // update header with final size
3688 uint64_t slideInfoSize = align(info->page_extras_offset + pageExtras.size()*sizeof(uint16_t), _archLayout->sharedRegionAlignP2);
3689 dataRegion.slideInfoFileSize = slideInfoSize;
3690 if ( dataRegion.slideInfoFileSize > dataRegion.slideInfoBufferSizeAllocated ) {
3691 _diagnostics.error("kernel slide info overflow buffer");
3692 }
3693 // Update the mapping entry on the cache header
3694 const dyld_cache_header* cacheHeader = (dyld_cache_header*)_readExecuteRegion.buffer;
3695 dyld_cache_mapping_and_slide_info* slidableMappings = (dyld_cache_mapping_and_slide_info*)(_readExecuteRegion.buffer + cacheHeader->mappingWithSlideOffset);
3696 slidableMappings[1 + dataRegionIndex].slideInfoFileSize = dataRegion.slideInfoFileSize;
3697 //fprintf(stderr, "pageCount=%u, page_starts_count=%lu, page_extras_count=%lu\n", dataPageCount, pageStarts.size(), pageExtras.size());
3698 }
3699 }
3700
3701 #if SUPPORT_ARCH_arm64_32 || SUPPORT_ARCH_armv7k
3702 // fits in to int16_t
3703 static bool smallValue(uint64_t value)
3704 {
3705 uint32_t high = (value & 0xFFFF8000);
3706 return (high == 0) || (high == 0xFFFF8000);
3707 }
3708
3709 template <typename P>
3710 bool SharedCacheBuilder::makeRebaseChainV4(uint8_t* pageContent, uint16_t lastLocationOffset, uint16_t offset, const dyld_cache_slide_info4* info)
3711 {
3712 typedef typename P::uint_t pint_t;
3713
3714 const pint_t deltaMask = (pint_t)(info->delta_mask);
3715 const pint_t valueMask = ~deltaMask;
3716 const pint_t valueAdd = (pint_t)(info->value_add);
3717 const unsigned deltaShift = __builtin_ctzll(deltaMask) - 2;
3718 const uint32_t maxDelta = (uint32_t)(deltaMask >> deltaShift);
3719
3720 pint_t* lastLoc = (pint_t*)&pageContent[lastLocationOffset+0];
3721 pint_t lastValue = (pint_t)P::getP(*lastLoc);
3722 if ( (lastValue - valueAdd) & deltaMask ) {
3723 std::string dylibName;
3724 std::string segName;
3725 findDylibAndSegment((void*)pageContent, dylibName, segName);
3726 _diagnostics.error("rebase pointer does not point within cache. lastOffset=0x%04X, seg=%s, dylib=%s\n",
3727 lastLocationOffset, segName.c_str(), dylibName.c_str());
3728 return false;
3729 }
3730 if ( offset <= (lastLocationOffset+maxDelta) ) {
3731 // previous location in range, make link from it
3732 // encode this location into last value
3733 pint_t delta = offset - lastLocationOffset;
3734 pint_t newLastValue = ((lastValue - valueAdd) & valueMask) | (delta << deltaShift);
3735 //warning(" add chain: delta = %d, lastOffset=0x%03X, offset=0x%03X, org value=0x%08lX, new value=0x%08lX",
3736 // offset - lastLocationOffset, lastLocationOffset, offset, (long)lastValue, (long)newLastValue);
3737 P::setP(*lastLoc, newLastValue);
3738 return true;
3739 }
3740 //fprintf(stderr, " too big delta = %d, lastOffset=0x%03X, offset=0x%03X\n", offset - lastLocationOffset, lastLocationOffset, offset);
3741
3742 // distance between rebase locations is too far
3743 // see if we can make a chain from non-rebase locations
3744 uint16_t nonRebaseLocationOffsets[1024];
3745 unsigned nrIndex = 0;
3746 for (uint16_t i = lastLocationOffset; i < offset-maxDelta; ) {
3747 nonRebaseLocationOffsets[nrIndex] = 0;
3748 for (int j=maxDelta; j > 0; j -= 4) {
3749 pint_t value = (pint_t)P::getP(*(pint_t*)&pageContent[i+j]);
3750 if ( smallValue(value) ) {
3751 // Steal values of 0 to be used in the rebase chain
3752 nonRebaseLocationOffsets[nrIndex] = i+j;
3753 break;
3754 }
3755 }
3756 if ( nonRebaseLocationOffsets[nrIndex] == 0 ) {
3757 lastValue = (pint_t)P::getP(*lastLoc);
3758 pint_t newValue = ((lastValue - valueAdd) & valueMask);
3759 //fprintf(stderr, " no way to make non-rebase delta chain, terminate off=0x%03X, old value=0x%08lX, new value=0x%08lX\n",
3760 // lastLocationOffset, (long)lastValue, (long)newValue);
3761 P::setP(*lastLoc, newValue);
3762 return false;
3763 }
3764 i = nonRebaseLocationOffsets[nrIndex];
3765 ++nrIndex;
3766 }
3767
3768 // we can make chain. go back and add each non-rebase location to chain
3769 uint16_t prevOffset = lastLocationOffset;
3770 pint_t* prevLoc = (pint_t*)&pageContent[prevOffset];
3771 for (unsigned n=0; n < nrIndex; ++n) {
3772 uint16_t nOffset = nonRebaseLocationOffsets[n];
3773 assert(nOffset != 0);
3774 pint_t* nLoc = (pint_t*)&pageContent[nOffset];
3775 uint32_t delta2 = nOffset - prevOffset;
3776 pint_t value = (pint_t)P::getP(*prevLoc);
3777 pint_t newValue;
3778 if ( smallValue(value) )
3779 newValue = (value & valueMask) | (delta2 << deltaShift);
3780 else
3781 newValue = ((value - valueAdd) & valueMask) | (delta2 << deltaShift);
3782 //warning(" non-rebase delta = %d, to off=0x%03X, old value=0x%08lX, new value=0x%08lX", delta2, nOffset, (long)value, (long)newValue);
3783 P::setP(*prevLoc, newValue);
3784 prevOffset = nOffset;
3785 prevLoc = nLoc;
3786 }
3787 uint32_t delta3 = offset - prevOffset;
3788 pint_t value = (pint_t)P::getP(*prevLoc);
3789 pint_t newValue;
3790 if ( smallValue(value) )
3791 newValue = (value & valueMask) | (delta3 << deltaShift);
3792 else
3793 newValue = ((value - valueAdd) & valueMask) | (delta3 << deltaShift);
3794 //warning(" non-rebase delta = %d, to off=0x%03X, old value=0x%08lX, new value=0x%08lX", delta3, offset, (long)value, (long)newValue);
3795 P::setP(*prevLoc, newValue);
3796
3797 return true;
3798 }
3799
3800
3801 template <typename P>
3802 void SharedCacheBuilder::addPageStartsV4(uint8_t* pageContent, const bool bitmap[], const dyld_cache_slide_info4* info,
3803 std::vector<uint16_t>& pageStarts, std::vector<uint16_t>& pageExtras)
3804 {
3805 typedef typename P::uint_t pint_t;
3806
3807 const pint_t deltaMask = (pint_t)(info->delta_mask);
3808 const pint_t valueMask = ~deltaMask;
3809 const uint32_t pageSize = info->page_size;
3810 const pint_t valueAdd = (pint_t)(info->value_add);
3811
3812 uint16_t startValue = DYLD_CACHE_SLIDE4_PAGE_NO_REBASE;
3813 uint16_t lastLocationOffset = 0xFFFF;
3814 for(uint32_t i=0; i < pageSize/4; ++i) {
3815 unsigned offset = i*4;
3816 if ( bitmap[i] ) {
3817 if ( startValue == DYLD_CACHE_SLIDE4_PAGE_NO_REBASE ) {
3818 // found first rebase location in page
3819 startValue = i;
3820 }
3821 else if ( !makeRebaseChainV4<P>(pageContent, lastLocationOffset, offset, info) ) {
3822 // can't record all rebasings in one chain
3823 if ( (startValue & DYLD_CACHE_SLIDE4_PAGE_USE_EXTRA) == 0 ) {
3824 // switch page_start to "extras" which is a list of chain starts
3825 unsigned indexInExtras = (unsigned)pageExtras.size();
3826 if ( indexInExtras >= DYLD_CACHE_SLIDE4_PAGE_INDEX ) {
3827 _diagnostics.error("rebase overflow in v4 page extras");
3828 return;
3829 }
3830 pageExtras.push_back(startValue);
3831 startValue = indexInExtras | DYLD_CACHE_SLIDE4_PAGE_USE_EXTRA;
3832 }
3833 pageExtras.push_back(i);
3834 }
3835 lastLocationOffset = offset;
3836 }
3837 }
3838 if ( lastLocationOffset != 0xFFFF ) {
3839 // mark end of chain
3840 pint_t* lastLoc = (pint_t*)&pageContent[lastLocationOffset];
3841 pint_t lastValue = (pint_t)P::getP(*lastLoc);
3842 pint_t newValue = ((lastValue - valueAdd) & valueMask);
3843 P::setP(*lastLoc, newValue);
3844 if ( startValue & DYLD_CACHE_SLIDE4_PAGE_USE_EXTRA ) {
3845 // add end bit to extras
3846 pageExtras.back() |= DYLD_CACHE_SLIDE4_PAGE_EXTRA_END;
3847 }
3848 }
3849 pageStarts.push_back(startValue);
3850 }
3851
3852
3853
3854 template <typename P>
3855 void SharedCacheBuilder::writeSlideInfoV4(const bool bitmapForAllDataRegions[], unsigned dataPageCountForAllDataRegions)
3856 {
3857 typedef typename P::uint_t pint_t;
3858 typedef typename P::E E;
3859
3860 const uint32_t pageSize = _aslrTracker.pageSize();
3861 const uint8_t* firstDataRegionBuffer = firstDataRegion()->buffer;
3862 for (uint32_t dataRegionIndex = 0; dataRegionIndex != _dataRegions.size(); ++dataRegionIndex) {
3863 Region& dataRegion = _dataRegions[dataRegionIndex];
3864
3865 // fill in fixed info
3866 assert(dataRegion.slideInfoFileOffset != 0);
3867 assert((dataRegion.sizeInUse % pageSize) == 0);
3868 unsigned dataPageCount = (uint32_t)dataRegion.sizeInUse / pageSize;
3869 dyld_cache_slide_info4* info = (dyld_cache_slide_info4*)dataRegion.slideInfoBuffer;
3870 info->version = 4;
3871 info->page_size = pageSize;
3872 info->delta_mask = _archLayout->pointerDeltaMask;
3873 info->value_add = info->value_add = _archLayout->useValueAdd ? _archLayout->sharedMemoryStart : 0;
3874
3875 // set page starts and extras for each page
3876 std::vector<uint16_t> pageStarts;
3877 std::vector<uint16_t> pageExtras;
3878 pageStarts.reserve(dataPageCount);
3879 const size_t bitmapEntriesPerPage = (sizeof(bool)*(pageSize/4));
3880 uint8_t* pageContent = dataRegion.buffer;
3881 unsigned numPagesFromFirstDataRegion = (uint32_t)(dataRegion.buffer - firstDataRegionBuffer) / pageSize;
3882 assert((numPagesFromFirstDataRegion + dataPageCount) <= dataPageCountForAllDataRegions);
3883 const bool* bitmapForRegion = (const bool*)bitmapForAllDataRegions + (bitmapEntriesPerPage * numPagesFromFirstDataRegion);
3884 const bool* bitmapForPage = bitmapForRegion;
3885 for (unsigned i=0; i < dataPageCount; ++i) {
3886 addPageStartsV4<P>(pageContent, bitmapForPage, info, pageStarts, pageExtras);
3887 if ( _diagnostics.hasError() ) {
3888 return;
3889 }
3890 pageContent += pageSize;
3891 bitmapForPage += (sizeof(bool)*(pageSize/4));
3892 }
3893 // fill in computed info
3894 info->page_starts_offset = sizeof(dyld_cache_slide_info4);
3895 info->page_starts_count = (unsigned)pageStarts.size();
3896 info->page_extras_offset = (unsigned)(sizeof(dyld_cache_slide_info4)+pageStarts.size()*sizeof(uint16_t));
3897 info->page_extras_count = (unsigned)pageExtras.size();
3898 uint16_t* pageStartsBuffer = (uint16_t*)((char*)info + info->page_starts_offset);
3899 uint16_t* pageExtrasBuffer = (uint16_t*)((char*)info + info->page_extras_offset);
3900 for (unsigned i=0; i < pageStarts.size(); ++i)
3901 pageStartsBuffer[i] = pageStarts[i];
3902 for (unsigned i=0; i < pageExtras.size(); ++i)
3903 pageExtrasBuffer[i] = pageExtras[i];
3904 // update header with final size
3905 uint64_t slideInfoSize = align(info->page_extras_offset + pageExtras.size()*sizeof(uint16_t), _archLayout->sharedRegionAlignP2);
3906 dataRegion.slideInfoFileSize = slideInfoSize;
3907 if ( dataRegion.slideInfoFileSize > dataRegion.slideInfoBufferSizeAllocated ) {
3908 _diagnostics.error("kernel slide info overflow buffer");
3909 }
3910 // Update the mapping entry on the cache header
3911 const dyld_cache_header* cacheHeader = (dyld_cache_header*)_readExecuteRegion.buffer;
3912 dyld_cache_mapping_and_slide_info* slidableMappings = (dyld_cache_mapping_and_slide_info*)(_readExecuteRegion.buffer + cacheHeader->mappingWithSlideOffset);
3913 slidableMappings[1 + dataRegionIndex].slideInfoFileSize = dataRegion.slideInfoFileSize;
3914 //fprintf(stderr, "pageCount=%u, page_starts_count=%lu, page_extras_count=%lu\n", dataPageCount, pageStarts.size(), pageExtras.size());
3915 }
3916 }
3917 #endif
3918
3919 /*
3920 void CacheBuilder::writeSlideInfoV1()
3921 {
3922 // build one 128-byte bitmap per page (4096) of DATA
3923 uint8_t* const dataStart = (uint8_t*)_buffer.get() + regions[1].fileOffset;
3924 uint8_t* const dataEnd = dataStart + regions[1].size;
3925 const long bitmapSize = (dataEnd - dataStart)/(4*8);
3926 uint8_t* bitmap = (uint8_t*)calloc(bitmapSize, 1);
3927 for (void* p : _pointersForASLR) {
3928 if ( (p < dataStart) || ( p > dataEnd) )
3929 terminate("DATA pointer for sliding, out of range\n");
3930 long offset = (long)((uint8_t*)p - dataStart);
3931 if ( (offset % 4) != 0 )
3932 terminate("pointer not 4-byte aligned in DATA offset 0x%08lX\n", offset);
3933 long byteIndex = offset / (4*8);
3934 long bitInByte = (offset % 32) >> 2;
3935 bitmap[byteIndex] |= (1 << bitInByte);
3936 }
3937
3938 // allocate worst case size block of all slide info
3939 const unsigned entry_size = 4096/(8*4); // 8 bits per byte, possible pointer every 4 bytes.
3940 const unsigned toc_count = (unsigned)bitmapSize/entry_size;
3941 dyld_cache_slide_info* slideInfo = (dyld_cache_slide_info*)((uint8_t*)_buffer + _slideInfoFileOffset);
3942 slideInfo->version = 1;
3943 slideInfo->toc_offset = sizeof(dyld_cache_slide_info);
3944 slideInfo->toc_count = toc_count;
3945 slideInfo->entries_offset = (slideInfo->toc_offset+2*toc_count+127)&(-128);
3946 slideInfo->entries_count = 0;
3947 slideInfo->entries_size = entry_size;
3948 // append each unique entry
3949 const dyldCacheSlideInfoEntry* bitmapAsEntries = (dyldCacheSlideInfoEntry*)bitmap;
3950 dyldCacheSlideInfoEntry* const entriesInSlidInfo = (dyldCacheSlideInfoEntry*)((char*)slideInfo+slideInfo->entries_offset());
3951 int entry_count = 0;
3952 for (int i=0; i < toc_count; ++i) {
3953 const dyldCacheSlideInfoEntry* thisEntry = &bitmapAsEntries[i];
3954 // see if it is same as one already added
3955 bool found = false;
3956 for (int j=0; j < entry_count; ++j) {
3957 if ( memcmp(thisEntry, &entriesInSlidInfo[j], entry_size) == 0 ) {
3958 slideInfo->set_toc(i, j);
3959 found = true;
3960 break;
3961 }
3962 }
3963 if ( !found ) {
3964 // append to end
3965 memcpy(&entriesInSlidInfo[entry_count], thisEntry, entry_size);
3966 slideInfo->set_toc(i, entry_count++);
3967 }
3968 }
3969 slideInfo->entries_count = entry_count;
3970 ::free((void*)bitmap);
3971
3972 _buffer.header->slideInfoSize = align(slideInfo->entries_offset + entry_count*entry_size, _archLayout->sharedRegionAlignP2);
3973 }
3974
3975 */
3976
3977
3978 void SharedCacheBuilder::setPointerContentV3(dyld3::MachOLoaded::ChainedFixupPointerOnDisk* loc, uint64_t targetVMAddr, size_t next)
3979 {
3980 assert(targetVMAddr > _readExecuteRegion.unslidLoadAddress);
3981 assert(targetVMAddr < _readOnlyRegion.unslidLoadAddress+_readOnlyRegion.sizeInUse);
3982 dyld3::MachOLoaded::ChainedFixupPointerOnDisk tmp;
3983 uint16_t diversity;
3984 bool hasAddrDiv;
3985 uint8_t key;
3986 if ( _aslrTracker.hasAuthData(loc, &diversity, &hasAddrDiv, &key) ) {
3987 // if base cache address cannot fit into target, then use offset
3988 tmp.arm64e.authRebase.target = _readExecuteRegion.unslidLoadAddress;
3989 if ( tmp.arm64e.authRebase.target != _readExecuteRegion.unslidLoadAddress )
3990 targetVMAddr -= _readExecuteRegion.unslidLoadAddress;
3991 loc->arm64e.authRebase.target = targetVMAddr;
3992 loc->arm64e.authRebase.diversity = diversity;
3993 loc->arm64e.authRebase.addrDiv = hasAddrDiv;
3994 loc->arm64e.authRebase.key = key;
3995 loc->arm64e.authRebase.next = next;
3996 loc->arm64e.authRebase.bind = 0;
3997 loc->arm64e.authRebase.auth = 1;
3998 assert(loc->arm64e.authRebase.target == targetVMAddr && "target truncated");
3999 assert(loc->arm64e.authRebase.next == next && "next location truncated");
4000 }
4001 else {
4002 uint8_t highByte = 0;
4003 _aslrTracker.hasHigh8(loc, &highByte);
4004 // if base cache address cannot fit into target, then use offset
4005 tmp.arm64e.rebase.target = _readExecuteRegion.unslidLoadAddress;
4006 if ( tmp.arm64e.rebase.target != _readExecuteRegion.unslidLoadAddress )
4007 targetVMAddr -= _readExecuteRegion.unslidLoadAddress;
4008 loc->arm64e.rebase.target = targetVMAddr;
4009 loc->arm64e.rebase.high8 = highByte;
4010 loc->arm64e.rebase.next = next;
4011 loc->arm64e.rebase.bind = 0;
4012 loc->arm64e.rebase.auth = 0;
4013 assert(loc->arm64e.rebase.target == targetVMAddr && "target truncated");
4014 assert(loc->arm64e.rebase.next == next && "next location truncated");
4015 }
4016 }
4017
4018 uint16_t SharedCacheBuilder::pageStartV3(uint8_t* pageContent, uint32_t pageSize, const bool bitmap[])
4019 {
4020 const int maxPerPage = pageSize / 4;
4021 uint16_t result = DYLD_CACHE_SLIDE_V3_PAGE_ATTR_NO_REBASE;
4022 dyld3::MachOLoaded::ChainedFixupPointerOnDisk* lastLoc = nullptr;
4023 for (int i=0; i < maxPerPage; ++i) {
4024 if ( bitmap[i] ) {
4025 if ( result == DYLD_CACHE_SLIDE_V3_PAGE_ATTR_NO_REBASE ) {
4026 // found first rebase location in page
4027 result = i * 4;
4028 }
4029 dyld3::MachOLoaded::ChainedFixupPointerOnDisk* loc = (dyld3::MachOLoaded::ChainedFixupPointerOnDisk*)(pageContent + i*4);;
4030 if ( lastLoc != nullptr ) {
4031 // convert vmaddr based pointers to arm64e dyld cache chains
4032 setPointerContentV3(lastLoc, lastLoc->raw64, loc - lastLoc);
4033 }
4034 lastLoc = loc;
4035 }
4036 }
4037 if ( lastLoc != nullptr ) {
4038 // convert vmaddr based pointers to arm64e dyld cache chain, and mark end of chain
4039 setPointerContentV3(lastLoc, lastLoc->raw64, 0);
4040 }
4041 return result;
4042 }
4043
4044
4045 void SharedCacheBuilder::writeSlideInfoV3(const bool bitmapForAllDataRegions[], unsigned dataPageCountForAllDataRegions)
4046 {
4047 const uint32_t pageSize = _aslrTracker.pageSize();
4048 const uint8_t* firstDataRegionBuffer = firstDataRegion()->buffer;
4049 for (uint32_t dataRegionIndex = 0; dataRegionIndex != _dataRegions.size(); ++dataRegionIndex) {
4050 Region& dataRegion = _dataRegions[dataRegionIndex];
4051 // fprintf(stderr, "writeSlideInfoV3: %s 0x%llx->0x%llx\n", dataRegion.name.c_str(), dataRegion.cacheFileOffset, dataRegion.cacheFileOffset + dataRegion.sizeInUse);
4052 // fill in fixed info
4053 assert(dataRegion.slideInfoFileOffset != 0);
4054 assert((dataRegion.sizeInUse % pageSize) == 0);
4055 unsigned dataPageCount = (uint32_t)dataRegion.sizeInUse / pageSize;
4056 dyld_cache_slide_info3* info = (dyld_cache_slide_info3*)dataRegion.slideInfoBuffer;
4057 info->version = 3;
4058 info->page_size = pageSize;
4059 info->page_starts_count = dataPageCount;
4060 info->auth_value_add = _archLayout->sharedMemoryStart;
4061
4062 // fill in per-page starts
4063 const size_t bitmapEntriesPerPage = (sizeof(bool)*(pageSize/4));
4064 uint8_t* pageContent = dataRegion.buffer;
4065 unsigned numPagesFromFirstDataRegion = (uint32_t)(dataRegion.buffer - firstDataRegionBuffer) / pageSize;
4066 assert((numPagesFromFirstDataRegion + dataPageCount) <= dataPageCountForAllDataRegions);
4067 const bool* bitmapForRegion = (const bool*)bitmapForAllDataRegions + (bitmapEntriesPerPage * numPagesFromFirstDataRegion);
4068 const bool* bitmapForPage = bitmapForRegion;
4069 //for (unsigned i=0; i < dataPageCount; ++i) {
4070 dispatch_apply(dataPageCount, DISPATCH_APPLY_AUTO, ^(size_t i) {
4071 info->page_starts[i] = pageStartV3(pageContent + (i * pageSize), pageSize, bitmapForPage + (i * bitmapEntriesPerPage));
4072 });
4073
4074 // update region with final size
4075 dataRegion.slideInfoFileSize = align(__offsetof(dyld_cache_slide_info3, page_starts[dataPageCount]), _archLayout->sharedRegionAlignP2);
4076 if ( dataRegion.slideInfoFileSize > dataRegion.slideInfoBufferSizeAllocated ) {
4077 _diagnostics.error("kernel slide info overflow buffer");
4078 }
4079 // Update the mapping entry on the cache header
4080 const dyld_cache_header* cacheHeader = (dyld_cache_header*)_readExecuteRegion.buffer;
4081 dyld_cache_mapping_and_slide_info* slidableMappings = (dyld_cache_mapping_and_slide_info*)(_readExecuteRegion.buffer + cacheHeader->mappingWithSlideOffset);
4082 slidableMappings[1 + dataRegionIndex].slideInfoFileSize = dataRegion.slideInfoFileSize;
4083 }
4084 }
mirror of dyld