dyld3/Closure.cpp

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25 #include <stdint.h>
  26 #include <assert.h>
  27 #include <uuid/uuid.h>
  28 #include <unistd.h>
  29 #include <limits.h>
  30 #include <mach-o/dyld_priv.h>
  31 #include <sys/stat.h>
  32 #include <sys/sysctl.h>
  33 #include <System/machine/cpu_capabilities.h>
  34
  35 extern "C" {
  36   #include <corecrypto/ccdigest.h>
  37   #include <corecrypto/ccsha2.h>
  38 }
  39
  40 #include "Closure.h"
  41 #include "MachOFile.h"
  42 #include "MachOLoaded.h"
  43 #include "StringUtils.h"
  44
  45 #include "objc-shared-cache.h"
  46
  47
  48 namespace dyld3 {
  49 namespace closure {
  50
  51
  52 ////////////////////////////  TypedBytes ////////////////////////////////////////
  53
  54 const void* TypedBytes::payload() const
  55 {
  56     return (uint8_t*)this + sizeof(TypedBytes);
  57 }
  58
  59 void* TypedBytes::payload()
  60 {
  61     return (uint8_t*)this + sizeof(TypedBytes);
  62 }
  63
  64
  65 ////////////////////////////  ContainerTypedBytes ////////////////////////////////////////
  66
  67 const TypedBytes* ContainerTypedBytes::first() const
  68 {
  69     return (TypedBytes*)payload();
  70 }
  71
  72 const TypedBytes* ContainerTypedBytes::next(const TypedBytes* p) const
  73 {
  74     assert((p->payloadLength & 0x3) == 0);
  75     return (TypedBytes*)((uint8_t*)(p->payload()) + p->payloadLength);
  76 }
  77
  78 void ContainerTypedBytes::forEachAttribute(void (^handler)(const TypedBytes* typedBytes, bool& stop)) const
  79 {
  80     assert(((long)this & 0x3) == 0);
  81     const TypedBytes* end = next(this);
  82     bool stop = false;
  83     for (const TypedBytes* p = first(); p < end && !stop; p = next(p)) {
  84         handler(p, stop);
  85     }
  86 }
  87
  88 void ContainerTypedBytes::forEachAttributePayload(Type requestedType, void (^handler)(const void* payload, uint32_t size, bool& stop)) const
  89 {
  90     forEachAttribute(^(const TypedBytes* typedBytes, bool& stop) {
  91         if ( (Type)(typedBytes->type) != requestedType )
  92             return;
  93         handler(typedBytes->payload(), typedBytes->payloadLength, stop);
  94     });
  95 }
  96
  97 const void* ContainerTypedBytes::findAttributePayload(Type requestedType, uint32_t* payloadSize) const
  98 {
  99     assert(((long)this & 0x3) == 0);
 100     if ( payloadSize != nullptr )
 101         *payloadSize = 0;
 102     const TypedBytes* end = next(this);
 103     bool stop = false;
 104     for (const TypedBytes* p = first(); p < end && !stop; p = next(p)) {
 105         if ( (Type)(p->type) == requestedType ) {
 106             if ( payloadSize != nullptr )
 107                 *payloadSize = p->payloadLength;
 108             return p->payload();
 109         }
 110     }
 111     return nullptr;
 112 }
 113
 114
 115 ////////////////////////////  Image ////////////////////////////////////////
 116
 117 const Image::Flags& Image::getFlags() const
 118 {
 119     return *(Flags*)((uint8_t*)this + 2*sizeof(TypedBytes));
 120 }
 121
 122 bool Image::isInvalid() const
 123 {
 124     return getFlags().isInvalid;
 125 }
 126
 127 size_t Image::size() const
 128 {
 129     return sizeof(TypedBytes) + this->payloadLength;
 130 }
 131
 132 ImageNum Image::imageNum() const
 133 {
 134     return getFlags().imageNum;
 135 }
 136
 137 // returns true iff 'num' is this image's ImageNum, or this image overrides that imageNum (in dyld cache)
 138 bool Image::representsImageNum(ImageNum num) const
 139 {
 140     const Flags& flags = getFlags();
 141     if ( flags.imageNum == num )
 142         return true;
 143     if ( !flags.isDylib )
 144         return false;
 145     if ( flags.inDyldCache )
 146         return false;
 147     ImageNum cacheImageNum;
 148     if ( isOverrideOfDyldCacheImage(cacheImageNum) )
 149         return (cacheImageNum == num);
 150     return false;
 151 }
 152
 153 uint32_t Image::maxLoadCount() const
 154 {
 155     return getFlags().maxLoadCount;
 156 }
 157
 158 bool Image::isBundle() const
 159 {
 160     return getFlags().isBundle;
 161 }
 162
 163 bool Image::isDylib() const
 164 {
 165     return getFlags().isDylib;
 166 }
 167
 168 bool Image::isExecutable() const
 169 {
 170     return getFlags().isExecutable;
 171 }
 172
 173 bool Image::hasObjC() const
 174 {
 175     return getFlags().hasObjC;
 176 }
 177
 178 bool Image::is64() const
 179 {
 180     return getFlags().is64;
 181 }
 182
 183 bool Image::hasWeakDefs() const
 184 {
 185     return getFlags().hasWeakDefs;
 186 }
 187
 188 bool Image::mayHavePlusLoads() const
 189 {
 190     return getFlags().mayHavePlusLoads;
 191 }
 192
 193 bool Image::neverUnload() const
 194 {
 195     return getFlags().neverUnload;
 196 }
 197
 198 bool Image::overridableDylib() const
 199 {
 200     return getFlags().overridableDylib;
 201 }
 202
 203 bool Image::inDyldCache() const
 204 {
 205     return getFlags().inDyldCache;
 206 }
 207
 208 const char* Image::path() const
 209 {
 210     // might be multiple pathWithHash enties, first is canonical name
 211     const PathAndHash* result = (PathAndHash*)findAttributePayload(Type::pathWithHash);
 212     assert(result && "Image missing pathWithHash");
 213     return result->path;
 214 }
 215
 216 const char* Image::leafName() const
 217 {
 218     uint32_t size;
 219     // might be multiple pathWithHash enties, first is canonical name
 220     const PathAndHash* result = (PathAndHash*)findAttributePayload(Type::pathWithHash, &size);
 221     assert(result && "Image missing pathWithHash");
 222     for (const char* p=(char*)result + size; p > result->path; --p) {
 223         if ( *p == '/' )
 224             return p+1;
 225     }
 226     return result->path;
 227 }
 228
 229 bool Image::hasFileModTimeAndInode(uint64_t& inode, uint64_t& mTime) const
 230 {
 231     uint32_t size;
 232     const FileInfo* info = (FileInfo*)(findAttributePayload(Type::fileInodeAndTime, &size));
 233     if ( info != nullptr ) {
 234         assert(size == sizeof(FileInfo));
 235         inode = info->inode;
 236         mTime = info->modTime;
 237         return true;
 238     }
 239     return false;
 240 }
 241
 242 void Image::forEachCDHash(void (^handler)(const uint8_t cdHash[20], bool& stop)) const
 243 {
 244     forEachAttribute(^(const TypedBytes* typedBytes, bool& stopLoop) {
 245         if ( (Type)(typedBytes->type) != Type::cdHash )
 246             return;
 247         assert(typedBytes->payloadLength == 20);
 248         const uint8_t* bytes = (const uint8_t*)typedBytes->payload();
 249         handler(bytes, stopLoop);
 250     });
 251 }
 252
 253 bool Image::getUuid(uuid_t uuid) const
 254 {
 255     uint32_t size;
 256     const uint8_t* bytes = (uint8_t*)(findAttributePayload(Type::uuid, &size));
 257     if ( bytes == nullptr )
 258         return false;
 259     assert(size == 16);
 260     memcpy(uuid, bytes, 16);
 261     return true;
 262 }
 263
 264 bool Image::hasCodeSignature(uint32_t& sigFileOffset, uint32_t& sigSize) const
 265 {
 266     uint32_t sz;
 267     const Image::CodeSignatureLocation* sigInfo = (Image::CodeSignatureLocation*)(findAttributePayload(Type::codeSignLoc, &sz));
 268     if ( sigInfo != nullptr ) {
 269         assert(sz == sizeof(Image::CodeSignatureLocation));
 270         sigFileOffset = sigInfo->fileOffset;
 271         sigSize       = sigInfo->fileSize;
 272         return true;
 273     }
 274     return false;
 275 }
 276
 277 bool Image::isFairPlayEncrypted(uint32_t& textOffset, uint32_t& size) const
 278 {
 279     uint32_t sz;
 280     const Image::FairPlayRange* fpInfo = (Image::FairPlayRange*)(findAttributePayload(Type::fairPlayLoc, &sz));
 281     if ( fpInfo != nullptr ) {
 282         assert(sz == sizeof(Image::FairPlayRange));
 283         textOffset = fpInfo->rangeStart;
 284         size       = fpInfo->rangeLength;
 285         return true;
 286     }
 287     return false;
 288 }
 289
 290 const Array<Image::LinkedImage> Image::dependentsArray() const
 291 {
 292     uint32_t size;
 293     LinkedImage* dependents = (LinkedImage*)findAttributePayload(Type::dependents, &size);
 294     assert((size % sizeof(LinkedImage)) == 0);
 295     uintptr_t count = size / sizeof(LinkedImage);
 296     return Array<Image::LinkedImage>(dependents, count, count);
 297 }
 298
 299 void Image::forEachDependentImage(void (^handler)(uint32_t dependentIndex, LinkKind kind, ImageNum imageNum, bool& stop)) const
 300 {
 301     uint32_t size;
 302     const LinkedImage* dependents = (LinkedImage*)findAttributePayload(Type::dependents, &size);
 303     assert((size % sizeof(LinkedImage)) == 0);
 304     const uint32_t count = size / sizeof(LinkedImage);
 305     bool stop = false;
 306     for (uint32_t i=0; (i < count) && !stop; ++i) {
 307         LinkKind kind     = dependents[i].kind();
 308         ImageNum imageNum = dependents[i].imageNum();
 309         // ignore missing weak links
 310         if ( (imageNum == kMissingWeakLinkedImage) && (kind == LinkKind::weak) )
 311             continue;
 312         handler(i, kind, imageNum, stop);
 313     }
 314 }
 315
 316 ImageNum Image::dependentImageNum(uint32_t depIndex) const
 317 {
 318     uint32_t size;
 319     const LinkedImage* dependents = (LinkedImage*)findAttributePayload(Type::dependents, &size);
 320     assert((size % sizeof(LinkedImage)) == 0);
 321     const uint32_t count = size / sizeof(LinkedImage);
 322     assert(depIndex < count);
 323     return dependents[depIndex].imageNum();
 324 }
 325
 326
 327 uint32_t Image::hashFunction(const char* str)
 328 {
 329     uint32_t h = 0;
 330     for (const char* s=str; *s != '\0'; ++s)
 331         h = h*5 + *s;
 332     return h;
 333 }
 334
 335 void Image::forEachAlias(void (^handler)(const char* aliasPath, bool& stop)) const
 336 {
 337     __block bool foundFirst = false;
 338     forEachAttribute(^(const TypedBytes* typedBytes, bool& stopLoop) {
 339         if ( (Type)(typedBytes->type) != Type::pathWithHash )
 340             return;
 341         if ( foundFirst ) {
 342             const PathAndHash* aliasInfo = (PathAndHash*)typedBytes->payload();
 343             handler(aliasInfo->path, stopLoop);
 344         }
 345         else {
 346             foundFirst = true;
 347         }
 348     });
 349 }
 350
 351 bool Image::hasPathWithHash(const char* path, uint32_t hash) const
 352 {
 353     __block bool found = false;
 354     forEachAttribute(^(const TypedBytes* typedBytes, bool& stop) {
 355         if ( (Type)(typedBytes->type) != Type::pathWithHash )
 356             return;
 357         const PathAndHash* pathInfo = (PathAndHash*)typedBytes->payload();
 358         if ( (pathInfo->hash == hash) && (strcmp(path, pathInfo->path) == 0) ) {
 359             stop = true;
 360             found = true;
 361         }
 362     });
 363     return found;
 364 }
 365
 366 void Image::forEachDiskSegment(void (^handler)(uint32_t segIndex, uint32_t fileOffset, uint32_t fileSize, int64_t vmOffset, uint64_t vmSize,
 367                                                uint8_t permissions, bool laterReadOnly, bool& stop)) const
 368 {
 369     uint32_t size;
 370     const DiskSegment* segments = (DiskSegment*)findAttributePayload(Type::diskSegment, &size);
 371     assert(segments != nullptr);
 372     assert((size % sizeof(DiskSegment)) == 0);
 373     const uint32_t  count        = size / sizeof(DiskSegment);
 374     const uint32_t  pageSz       = pageSize();
 375     uint32_t        segIndex     = 0;
 376     uint32_t        fileOffset   = 0;
 377     int64_t         vmOffset     = 0;
 378     // decrement vmOffset by all segments before TEXT (e.g. PAGEZERO)
 379     for (uint32_t i=0; i < count; ++i) {
 380         const DiskSegment* seg = &segments[i];
 381         if ( seg->filePageCount != 0 ) {
 382             break;
 383         }
 384         vmOffset -= (uint64_t)seg->vmPageCount * pageSz;
 385     }
 386     // walk each segment and call handler
 387     bool stop = false;
 388     for (uint32_t i=0; i < count && !stop; ++i) {
 389         const DiskSegment* seg = &segments[i];
 390         uint64_t vmSize   = (uint64_t)seg->vmPageCount * pageSz;
 391         uint32_t fileSize = seg->filePageCount * pageSz;
 392         if ( !seg->paddingNotSeg ) {
 393             uint8_t perms   = seg->permissions;
 394             bool    laterRO = false;
 395             // read-only data segments are encoded as .w. , initially make them r/w
 396             if ( perms == Image::DiskSegment::kReadOnlyDataPermissions ) {
 397                 perms   = VM_PROT_READ|VM_PROT_WRITE;
 398                 laterRO = true;
 399             }
 400             handler(segIndex, ( fileSize == 0) ? 0 : fileOffset, fileSize, vmOffset, vmSize, perms, laterRO, stop);
 401             ++segIndex;
 402         }
 403         vmOffset   += vmSize;
 404         fileOffset += fileSize;
 405     }
 406 }
 407
 408 uint32_t Image::pageSize() const
 409 {
 410     if ( getFlags().has16KBpages )
 411         return 0x4000;
 412     else
 413         return 0x1000;
 414 }
 415
 416 uint32_t Image::cacheOffset() const
 417 {
 418     uint32_t size;
 419     const DyldCacheSegment* segments = (DyldCacheSegment*)findAttributePayload(Type::cacheSegment, &size);
 420     assert(segments != nullptr);
 421     assert((size % sizeof(DyldCacheSegment)) == 0);
 422     return segments[0].cacheOffset;
 423 }
 424
 425 void Image::forEachCacheSegment(void (^handler)(uint32_t segIndex, uint64_t vmOffset, uint64_t vmSize, uint8_t permissions, bool& stop)) const
 426 {
 427     uint32_t size;
 428     const DyldCacheSegment* segments = (DyldCacheSegment*)findAttributePayload(Type::cacheSegment, &size);
 429     assert(segments != nullptr);
 430     assert((size % sizeof(DyldCacheSegment)) == 0);
 431     const uint32_t  count = size / sizeof(DyldCacheSegment);
 432     bool stop = false;
 433     for (uint32_t i=0; i < count; ++i) {
 434         uint64_t vmOffset    = segments[i].cacheOffset - segments[0].cacheOffset;
 435         uint64_t vmSize      = segments[i].size;
 436         uint8_t  permissions = segments[i].permissions;
 437         handler(i, vmOffset, vmSize, permissions, stop);
 438         if ( stop )
 439             break;
 440     }
 441 }
 442
 443 uint64_t Image::textSize() const
 444 {
 445     __block uint64_t result = 0;
 446     if ( inDyldCache() ) {
 447         forEachCacheSegment(^(uint32_t segIndex, uint64_t vmOffset, uint64_t vmSize, uint8_t permissions, bool& stop) {
 448             result = vmSize;
 449             stop = true;
 450         });
 451     }
 452     else {
 453         forEachDiskSegment(^(uint32_t segIndex, uint32_t fileOffset, uint32_t fileSize, int64_t vmOffset, uint64_t vmSize, uint8_t permissions, bool laterReadOnly, bool& stop) {
 454             if ( permissions != 0) {
 455                 result = vmSize;
 456                 stop = true;
 457             }
 458         });
 459     }
 460     return result;
 461 }
 462
 463 bool Image::containsAddress(const void* addr, const void* imageLoadAddress, uint8_t* permsResult) const
 464 {
 465     __block bool  result     = false;
 466     uint64_t      targetAddr = (uint64_t)addr;
 467     uint64_t      imageStart = (uint64_t)imageLoadAddress;
 468     if ( inDyldCache() ) {
 469         forEachCacheSegment(^(uint32_t segIndex, uint64_t vmOffset, uint64_t vmSize, uint8_t permissions, bool& stop) {
 470             if ( (targetAddr >= imageStart+vmOffset) && (targetAddr < imageStart+vmOffset+vmSize) ) {
 471                 result = true;
 472                 if ( permsResult )
 473                     *permsResult = permissions;
 474                 stop = true;
 475             }
 476         });
 477     }
 478     else {
 479         forEachDiskSegment(^(uint32_t segIndex, uint32_t fileOffset, uint32_t fileSize, int64_t vmOffset, uint64_t vmSize, uint8_t permissions, bool laterReadOnly, bool& stop) {
 480             if ( (targetAddr >= imageStart+vmOffset) && (targetAddr < imageStart+vmOffset+vmSize) ) {
 481                 result = true;
 482                 if ( permsResult )
 483                     *permsResult = permissions;
 484                 stop = true;
 485             }
 486         });
 487     }
 488     return result;
 489 }
 490
 491 uint64_t Image::vmSizeToMap() const
 492 {
 493     uint32_t size;
 494     const Image::MappingInfo* info = (Image::MappingInfo*)(findAttributePayload(Type::mappingInfo, &size));
 495     assert(info != nullptr);
 496     assert(size == sizeof(Image::MappingInfo));
 497     return info->totalVmPages * pageSize();
 498 }
 499
 500 uint64_t Image::sliceOffsetInFile() const
 501 {
 502     uint32_t size;
 503     const Image::MappingInfo* info = (Image::MappingInfo*)(findAttributePayload(Type::mappingInfo, &size));
 504     assert(info != nullptr);
 505     assert(size == sizeof(Image::MappingInfo));
 506     return info->sliceOffsetIn4K * 0x1000;
 507 }
 508
 509 void Image::forEachInitializer(const void* imageLoadAddress, void (^handler)(const void* initializer)) const
 510 {
 511     uint32_t size;
 512     const uint32_t* inits = (uint32_t*)findAttributePayload(Type::initOffsets, &size);
 513     if ( inits != nullptr ) {
 514         assert((size % sizeof(uint32_t)) == 0);
 515         const uint32_t count = size / sizeof(uint32_t);
 516         for (uint32_t i=0; i < count; ++i) {
 517             uint32_t offset = inits[i];
 518             const void* init = (void*)((uint8_t*)imageLoadAddress + offset);
 519             handler(init);
 520         }
 521         return;
 522     }
 523     const Image::InitializerSectionRange* range = (Image::InitializerSectionRange*)findAttributePayload(Type::initsSection, &size);
 524     if ( range != nullptr ) {
 525         const uint32_t pointerSize = is64() ? 8 : 4;
 526         const uint32_t* start32 = (uint32_t*)((uint8_t*)imageLoadAddress + range->sectionOffset);
 527         const uint64_t* start64 = (uint64_t*)((uint8_t*)imageLoadAddress + range->sectionOffset);
 528         const uint32_t count = range->sectionSize / pointerSize;
 529         for (uint32_t i=0; i < count; ++i) {
 530             if ( pointerSize == 8 )
 531                 handler((void*)(long)(start64[i]));
 532             else
 533                 handler((void*)(long)(start32[i]));
 534         }
 535     }
 536 }
 537
 538 bool Image::forEachInitializerSection(void (^handler)(uint32_t sectionOffset, uint32_t sectionSize)) const
 539 {
 540     __block bool result = false;
 541     forEachAttributePayload(Type::initsSection, ^(const void* payload, uint32_t size, bool& stop) {
 542         const Image::InitializerSectionRange* range = (Image::InitializerSectionRange*)payload;
 543         assert((size % sizeof(Image::InitializerSectionRange)) == 0);
 544         handler(range->sectionOffset, range->sectionSize);
 545         result = true;
 546     });
 547     return result;
 548 }
 549
 550 bool Image::hasInitializers() const
 551 {
 552     uint32_t size;
 553     return ( findAttributePayload(Type::initOffsets, &size) != nullptr );
 554 }
 555
 556 bool Image::hasTerminators() const
 557 {
 558     return getFlags().hasTerminators;
 559 }
 560
 561 bool Image::hasReadOnlyData() const
 562 {
 563     return getFlags().hasReadOnlyData;
 564 }
 565
 566 bool Image::hasChainedFixups() const
 567 {
 568     return getFlags().hasChainedFixups;
 569 }
 570
 571 bool Image::hasPrecomputedObjC() const
 572 {
 573     return getFlags().hasPrecomputedObjC;
 574 }
 575
 576 void Image::forEachTerminator(const void* imageLoadAddress, void (^handler)(const void* terminator)) const
 577 {
 578     uint32_t size;
 579     const uint32_t* terms = (uint32_t*)findAttributePayload(Type::termOffsets, &size);
 580     if ( terms != nullptr ) {
 581         assert((size % sizeof(uint32_t)) == 0);
 582         const uint32_t count = size / sizeof(uint32_t);
 583         for (uint32_t i=0; i < count; ++i) {
 584             uint32_t offset = terms[i];
 585             const void* term = (void*)((uint8_t*)imageLoadAddress + offset);
 586             handler(term);
 587         }
 588     }
 589 }
 590
 591 void Image::forEachDOF(const void* imageLoadAddress, void (^handler)(const void* dofSection)) const
 592 {
 593     uint32_t size;
 594     const uint32_t* dofs = (uint32_t*)findAttributePayload(Type::dofOffsets, &size);
 595     if ( dofs != nullptr ) {
 596         assert((size % sizeof(uint32_t)) == 0);
 597         const uint32_t count = size / sizeof(uint32_t);
 598         for (uint32_t i=0; i < count; ++i) {
 599             uint32_t offset = dofs[i];
 600             const void* sect = (void*)((uint8_t*)imageLoadAddress + offset);
 601             handler(sect);
 602         }
 603     }
 604 }
 605
 606 void Image::forEachFixup(void (^rebase)(uint64_t imageOffsetToRebase, bool& stop),
 607                          void (^bind)(uint64_t imageOffsetToBind, ResolvedSymbolTarget bindTarget, bool& stop),
 608                          void (^chainedFixups)(uint64_t imageOffsetToStarts, const Array<ResolvedSymbolTarget>& targets, bool& stop),
 609                          void (^fixupObjCImageInfo)(uint64_t imageOffsetToFixup),
 610                          void (^fixupObjCProtocol)(uint64_t imageOffsetToBind, ResolvedSymbolTarget bindTarget, bool& stop),
 611                          void (^fixupObjCSelRef)(uint64_t imageOffsetToFixup, uint32_t selectorIndex, bool inSharedCache, bool& stop),
 612                          void (^fixupObjCStableSwift)(uint64_t imageOffsetToFixup, bool& stop),
 613                          void (^fixupObjCMethodList)(uint64_t imageOffsetToFixup, bool& stop)) const
 614 {
 615     const uint32_t pointerSize = is64() ? 8 : 4;
 616         uint64_t curRebaseOffset = 0;
 617         bool stop = false;
 618     for (const Image::RebasePattern& rebasePat : rebaseFixups()) {
 619         //fprintf(stderr, " repeat=0x%04X, contig=%d, skip=%d\n", rebasePat.repeatCount, rebasePat.contigCount, rebasePat.skipCount);
 620         if ( rebasePat.contigCount == 0 ) {
 621             // note: contigCount==0 means this just advances location
 622             if ( (rebasePat.repeatCount == 0) && (rebasePat.skipCount == 0) ) {
 623                 // all zeros is special pattern that means reset to rebase offset to zero
 624                 curRebaseOffset = 0;
 625             }
 626             else {
 627                 curRebaseOffset += rebasePat.repeatCount * rebasePat.skipCount;
 628             }
 629         }
 630         else {
 631             for (int r=0; r < rebasePat.repeatCount && !stop; ++r) {
 632                 for (int i=0; i < rebasePat.contigCount && !stop; ++i) {
 633                     //fprintf(stderr, "  0x%08llX\n", curRebaseOffset);
 634                     rebase(curRebaseOffset, stop);
 635                     curRebaseOffset += pointerSize;
 636                 }
 637                 curRebaseOffset += pointerSize * rebasePat.skipCount;
 638             }
 639         }
 640         if ( stop )
 641             break;
 642     }
 643     if ( stop )
 644         return;
 645
 646     for (const Image::BindPattern& bindPat : bindFixups()) {
 647         uint64_t curBindOffset = bindPat.startVmOffset;
 648         for (uint16_t i=0; i < bindPat.repeatCount; ++i) {
 649             bind(curBindOffset, bindPat.target, stop);
 650             curBindOffset += (pointerSize * (1 + bindPat.skipCount));
 651             if ( stop )
 652                 break;
 653         }
 654         if ( stop )
 655             break;
 656     }
 657
 658     if (hasChainedFixups())
 659         chainedFixups(chainedStartsOffset(), chainedTargets(), stop);
 660
 661     if ( hasPrecomputedObjC() ) {
 662         ResolvedSymbolTarget objcProtocolClassTarget;
 663         uint64_t objcImageInfoVMOffset = 0;
 664         Array<ProtocolISAFixup> protocolISAFixups;
 665         Array<Image::SelectorReferenceFixup> selRefFixupEntries;
 666         Array<Image::ClassStableSwiftFixup> classStableSwiftFixups;
 667         Array<Image::MethodListFixup> methodListFixups;
 668         objcFixups(objcProtocolClassTarget, objcImageInfoVMOffset, protocolISAFixups,
 669                    selRefFixupEntries, classStableSwiftFixups, methodListFixups);
 670
 671         // Set the objc image info bit to tell libobjc we are optimized
 672         fixupObjCImageInfo(objcImageInfoVMOffset);
 673
 674
 675         // First bind all the protocols to the same Protocol class in libobjc
 676         for (const Image::ProtocolISAFixup& bindPat : protocolISAFixups) {
 677             uint64_t curBindOffset = bindPat.startVmOffset;
 678             for (uint16_t i=0; i < bindPat.repeatCount; ++i) {
 679                 fixupObjCProtocol(curBindOffset, objcProtocolClassTarget, stop);
 680                 curBindOffset += (pointerSize * (1 + bindPat.skipCount));
 681                 if ( stop )
 682                     break;
 683             }
 684             if ( stop )
 685                 break;
 686         }
 687
 688         for (uintptr_t i = 0, e = selRefFixupEntries.count(); i != e; ++i) {
 689             Image::SelectorReferenceFixup fixupEntry = selRefFixupEntries[i];
 690             // Start a new chain
 691             uint64_t curFixupOffset = fixupEntry.chainStartVMOffset;
 692             // Now walk the chain until we get a 'next' of 0
 693             while (i != e) {
 694                 fixupEntry = selRefFixupEntries[++i];
 695                 fixupObjCSelRef(curFixupOffset, fixupEntry.chainEntry.index, fixupEntry.chainEntry.inSharedCache, stop);
 696                 if ( stop )
 697                     break;
 698                 if ( fixupEntry.chainEntry.next == 0 )
 699                     break;
 700                 curFixupOffset += (4 * fixupEntry.chainEntry.next);
 701             }
 702         }
 703
 704         // Set classes to have stable Swift
 705         for (const Image::ClassStableSwiftFixup& bindPat : classStableSwiftFixups) {
 706             uint64_t curBindOffset = bindPat.startVmOffset;
 707             for (uint16_t i=0; i < bindPat.repeatCount; ++i) {
 708                 fixupObjCStableSwift(curBindOffset, stop);
 709                 curBindOffset += (pointerSize * (1 + bindPat.skipCount));
 710                 if ( stop )
 711                     break;
 712             }
 713             if ( stop )
 714                 break;
 715         }
 716
 717         // Set method lists to be fixed up
 718         for (const Image::MethodListFixup& bindPat : methodListFixups) {
 719             uint64_t curBindOffset = bindPat.startVmOffset;
 720             for (uint16_t i=0; i < bindPat.repeatCount; ++i) {
 721                 fixupObjCMethodList(curBindOffset, stop);
 722                 curBindOffset += (pointerSize * (1 + bindPat.skipCount));
 723                 if ( stop )
 724                     break;
 725             }
 726             if ( stop )
 727                 break;
 728         }
 729     }
 730 }
 731
 732 void Image::forEachTextReloc(void (^rebase)(uint32_t imageOffsetToRebase, bool& stop),
 733                              void (^bind)(uint32_t imageOffsetToBind, ResolvedSymbolTarget bindTarget, bool& stop)) const
 734 {
 735     bool stop = false;
 736     const Array<Image::TextFixupPattern> f = textFixups();
 737     for (const Image::TextFixupPattern& pat : f) {
 738         uint32_t curOffset = pat.startVmOffset;
 739         for (uint16_t i=0; i < pat.repeatCount; ++i) {
 740             if ( pat.target.raw == 0 )
 741                 rebase(curOffset, stop);
 742             else
 743                 bind(curOffset, pat.target, stop);
 744             curOffset += pat.skipCount;
 745         }
 746     }
 747 }
 748
 749 const Array<Image::RebasePattern> Image::rebaseFixups() const
 750 {
 751     uint32_t rebaseFixupsSize;
 752     Image::RebasePattern* rebaseFixupsContent = (RebasePattern*)findAttributePayload(Type::rebaseFixups, &rebaseFixupsSize);
 753     uint32_t rebaseCount = rebaseFixupsSize/sizeof(RebasePattern);
 754     return Array<RebasePattern>(rebaseFixupsContent, rebaseCount, rebaseCount);
 755 }
 756
 757 const Array<Image::BindPattern> Image::bindFixups() const
 758 {
 759     uint32_t bindFixupsSize;
 760     BindPattern* bindFixupsContent = (BindPattern*)findAttributePayload(Type::bindFixups, &bindFixupsSize);
 761     uint32_t bindCount = bindFixupsSize/sizeof(BindPattern);
 762     return Array<BindPattern>(bindFixupsContent, bindCount, bindCount);
 763 }
 764
 765 uint64_t Image::chainedStartsOffset() const
 766 {
 767     uint32_t size;
 768     uint64_t* startsOffset = (uint64_t*)findAttributePayload(Type::chainedStartsOffset, &size);
 769     if ( startsOffset == nullptr )
 770         return 0; // means no pre-computed offset to starts table
 771     assert(size == sizeof(uint64_t));
 772     return *startsOffset;
 773 }
 774
 775 void Image::objcFixups(ResolvedSymbolTarget& objcProtocolClassTarget,
 776                        uint64_t& objcImageInfoVMOffset,
 777                        Array<ProtocolISAFixup>& protocolISAFixups,
 778                        Array<SelectorReferenceFixup>& selRefFixups,
 779                        Array<ClassStableSwiftFixup>& classStableSwiftFixups,
 780                        Array<MethodListFixup>& methodListFixups) const
 781 {
 782     // The layout here is:
 783     //   ResolvedSymbolTarget
 784     //   uint64_t vmOffset to objc_imageinfo
 785     //   uint32_t protocol count
 786     //   uint32_t selector reference count
 787     //   array of ProtocolISAFixup
 788     //   array of SelectorReferenceFixup
 789     //   optional uint32_t stable swift fixup count
 790     //   optional uint32_t method list fixup count
 791     //   optional array of ClassStableSwiftFixup
 792     //   optional array of MethodListFixup
 793
 794     if (!hasPrecomputedObjC())
 795         return;
 796
 797     uint32_t contentSize;
 798     const uint8_t* fixupsContent = (uint8_t*)findAttributePayload(Type::objcFixups, &contentSize);
 799     const uint8_t* fixupsContentEnd = fixupsContent + contentSize;
 800
 801     // Get the statically sized data
 802     uint32_t protocolFixupCount = 0;
 803     uint32_t selRefFixupCount = 0;
 804     memcpy(&objcProtocolClassTarget, fixupsContent, sizeof(ResolvedSymbolTarget));
 805     fixupsContent += sizeof(ResolvedSymbolTarget);
 806     memcpy(&objcImageInfoVMOffset, fixupsContent, sizeof(uint64_t));
 807     fixupsContent += sizeof(uint64_t);
 808     memcpy(&protocolFixupCount, fixupsContent, sizeof(uint32_t));
 809     fixupsContent += sizeof(uint32_t);
 810     memcpy(&selRefFixupCount, fixupsContent, sizeof(uint32_t));
 811     fixupsContent += sizeof(uint32_t);
 812
 813     // Get the protocol fixups
 814     if ( protocolFixupCount != 0) {
 815         protocolISAFixups = Array<ProtocolISAFixup>((ProtocolISAFixup*)fixupsContent, protocolFixupCount, protocolFixupCount);
 816         fixupsContent += (sizeof(ProtocolISAFixup) * protocolFixupCount);
 817     }
 818
 819     // Get the selector reference fixups
 820     if ( selRefFixupCount != 0) {
 821         selRefFixups = Array<SelectorReferenceFixup>((SelectorReferenceFixup*)fixupsContent, selRefFixupCount, selRefFixupCount);
 822         fixupsContent += (sizeof(SelectorReferenceFixup) * selRefFixupCount);
 823     }
 824
 825     // Old closures end here, but newer ones might have additional fixups
 826     if (fixupsContent == fixupsContentEnd)
 827         return;
 828
 829     uint32_t stableSwiftFixupCount = 0;
 830     uint32_t methodListFixupCount = 0;
 831     memcpy(&stableSwiftFixupCount, fixupsContent, sizeof(uint32_t));
 832     fixupsContent += sizeof(uint32_t);
 833     memcpy(&methodListFixupCount, fixupsContent, sizeof(uint32_t));
 834     fixupsContent += sizeof(uint32_t);
 835
 836     // Get the stable swift fixups
 837     if ( stableSwiftFixupCount != 0) {
 838         classStableSwiftFixups = Array<ClassStableSwiftFixup>((ClassStableSwiftFixup*)fixupsContent, stableSwiftFixupCount, stableSwiftFixupCount);
 839         fixupsContent += (sizeof(ClassStableSwiftFixup) * stableSwiftFixupCount);
 840     }
 841
 842     // Get the method list fixups
 843     if ( methodListFixupCount != 0) {
 844         methodListFixups = Array<MethodListFixup>((MethodListFixup*)fixupsContent, methodListFixupCount, methodListFixupCount);
 845         fixupsContent += (sizeof(MethodListFixup) * methodListFixupCount);
 846     }
 847 }
 848
 849 const Array<Image::ResolvedSymbolTarget> Image::chainedTargets() const
 850 {
 851     uint32_t size;
 852     ResolvedSymbolTarget* targetsContent = (ResolvedSymbolTarget*)findAttributePayload(Type::chainedFixupsTargets, &size);
 853     uint32_t count = size/sizeof(ResolvedSymbolTarget);
 854     return Array<ResolvedSymbolTarget>(targetsContent, count, count);
 855 }
 856
 857 const Array<Image::TextFixupPattern> Image::textFixups() const
 858 {
 859     uint32_t fixupsSize;
 860     TextFixupPattern* fixupsContent = (TextFixupPattern*)findAttributePayload(Type::textFixups, &fixupsSize);
 861     uint32_t count = fixupsSize/sizeof(TextFixupPattern);
 862     return Array<TextFixupPattern>(fixupsContent, count, count);
 863 }
 864
 865 bool Image::isOverrideOfDyldCacheImage(ImageNum& imageNum) const
 866 {
 867         uint32_t size;
 868         const uint32_t* content = (uint32_t*)findAttributePayload(Type::imageOverride, &size);
 869         if ( content != nullptr ) {
 870         assert(size == sizeof(uint32_t));
 871         imageNum = *content;
 872         return true;
 873     }
 874     return false;
 875 }
 876
 877 void Image::forEachImageToInitBefore(void (^handler)(ImageNum imageToInit, bool& stop)) const
 878 {
 879     uint32_t size;
 880     const ImageNum* initBefores = (ImageNum*)findAttributePayload(Type::initBefores, &size);
 881     if ( initBefores != nullptr ) {
 882         assert((size % sizeof(ImageNum)) == 0);
 883         const uint32_t count = size / sizeof(ImageNum);
 884         bool stop = false;
 885         for (uint32_t i=0; (i < count) && !stop; ++i) {
 886             handler(initBefores[i], stop);
 887         }
 888     }
 889 }
 890
 891 ////////////////////////////  ImageArray ////////////////////////////////////////
 892
 893 size_t ImageArray::size() const
 894 {
 895     return sizeof(TypedBytes) + this->payloadLength;
 896 }
 897
 898 size_t ImageArray::startImageNum() const
 899 {
 900     return firstImageNum;
 901 }
 902
 903 uint32_t ImageArray::imageCount() const
 904 {
 905     return count;
 906 }
 907
 908 void ImageArray::forEachImage(void (^callback)(const Image* image, bool& stop)) const
 909 {
 910     bool stop = false;
 911     for (uint32_t i=0; i < count && !stop; ++i) {
 912         const Image* image = (Image*)((uint8_t*)payload() + offsets[i]);
 913         callback(image, stop);
 914         if (stop)
 915             break;
 916     }
 917 }
 918
 919 bool ImageArray::hasPath(const char* path, ImageNum& num) const
 920 {
 921     const uint32_t hash = Image::hashFunction(path);
 922     __block bool found = false;
 923     forEachImage(^(const Image* image, bool& stop) {
 924         if ( image->hasPathWithHash(path, hash) ) {
 925             num   = image->imageNum();
 926             found = true;
 927             stop  = true;
 928         }
 929     });
 930     return found;
 931 }
 932
 933 const Image* ImageArray::imageForNum(ImageNum num) const
 934 {
 935     if (hasRoots) {
 936         __block const Image* foundImage = nullptr;
 937         forEachImage(^(const Image *image, bool &stop) {
 938             if (image->imageNum() == num) {
 939                 foundImage = image;
 940                 stop = true;
 941             }
 942         });
 943         return foundImage;
 944     }
 945     if ( num < firstImageNum )
 946         return nullptr;
 947
 948     uint32_t index = num - firstImageNum;
 949     if ( index >= count )
 950         return nullptr;
 951
 952     return (Image*)((uint8_t*)payload() + offsets[index]);
 953 }
 954
 955 const Image* ImageArray::findImage(const Array<const ImageArray*> imagesArrays, ImageNum imageNum)
 956 {
 957    for (const ImageArray* ia : imagesArrays) {
 958         if ( const Image* result = ia->imageForNum(imageNum) )
 959             return result;
 960     }
 961     return nullptr;
 962 }
 963
 964 void ImageArray::deallocate() const
 965 {
 966     ::vm_deallocate(mach_task_self(), (long)this, size());
 967 }
 968
 969 ////////////////////////////  Closure ////////////////////////////////////////
 970
 971 size_t Closure::size() const
 972 {
 973     return sizeof(TypedBytes) + this->payloadLength;
 974 }
 975
 976 const ImageArray* Closure::images() const
 977 {
 978     __block const TypedBytes* result = nullptr;
 979     forEachAttribute(^(const TypedBytes* typedBytes, bool& stop) {
 980         if ( (Type)(typedBytes->type) == Type::imageArray ) {
 981             result = typedBytes;
 982             stop = true;
 983         }
 984     });
 985
 986     return (ImageArray*)result;
 987 }
 988
 989 ImageNum Closure::topImage() const
 990 {
 991     uint32_t size;
 992     const ImageNum* top = (ImageNum*)findAttributePayload(Type::topImage, &size);
 993     assert(top != nullptr);
 994     assert(size == sizeof(ImageNum));
 995     return *top;
 996 }
 997
 998 void Closure::forEachPatchEntry(void (^handler)(const PatchEntry& entry)) const
 999 {
1000         forEachAttributePayload(Type::cacheOverrides, ^(const void* payload, uint32_t size, bool& stop) {
1001         assert((size % sizeof(Closure::PatchEntry)) == 0);
1002         const PatchEntry* patches    = (PatchEntry*)payload;
1003         const PatchEntry* patchesEnd = (PatchEntry*)((char*)payload + size);
1004         for (const PatchEntry* p=patches; p < patchesEnd; ++p)
1005             handler(*p);
1006         });
1007 }
1008
1009 void Closure::forEachWarning(Closure::Warning::Type type, void (^handler)(const char* warning, bool& stop)) const
1010 {
1011     forEachAttributePayload(Type::warning, ^(const void* payload, uint32_t size, bool& stop) {
1012         const Closure::Warning* warning = (const Closure::Warning*)payload;
1013         if ( warning->type != type )
1014             return;
1015         handler(warning->message, stop);
1016     });
1017 }
1018
1019 void Closure::deallocate() const
1020 {
1021     ::vm_deallocate(mach_task_self(), (long)this, size());
1022 }
1023
1024 ////////////////////////////  LaunchClosure ////////////////////////////////////////
1025
1026 void LaunchClosure::forEachMustBeMissingFile(void (^handler)(const char* path, bool& stop)) const
1027 {
1028     uint32_t size;
1029     const char* paths = (const char*)findAttributePayload(Type::missingFiles, &size);
1030     bool stop = false;
1031     for (const char* s=paths; s < &paths[size]; ++s) {
1032         if ( *s != '\0' )
1033             handler(s, stop);
1034         if ( stop )
1035             break;
1036         s += strlen(s);
1037     }
1038 }
1039
1040 void LaunchClosure::forEachSkipIfExistsFile(void (^handler)(const SkippedFile& file, bool& stop)) const
1041 {
1042     uint32_t size;
1043     const uint64_t* files = (const uint64_t*)findAttributePayload(Type::existingFiles, &size);
1044     if (files == nullptr)
1045         return;
1046
1047     // The first entry is the length of the array
1048     uint64_t fileCount = *files++;
1049
1050     // Followed by count number of mod times and inodes
1051     const char* paths = (const char*)(files + (2 * fileCount));
1052     bool stop = false;
1053     for (const char* s=paths; s < &paths[size]; ++s) {
1054         if ( *s != '\0' ) {
1055             uint64_t inode = *files++;
1056             uint64_t mtime = *files++;
1057             SkippedFile skippedFile = { s, inode, mtime };
1058             handler(skippedFile, stop);
1059         }
1060         if ( stop )
1061             break;
1062         s += strlen(s);
1063     }
1064 }
1065
1066 bool LaunchClosure::builtAgainstDyldCache(uuid_t cacheUUID) const
1067 {
1068     uint32_t size;
1069     const uint8_t* uuidBytes = (uint8_t*)findAttributePayload(Type::dyldCacheUUID, &size);
1070     if ( uuidBytes == nullptr )
1071         return false;
1072     assert(size == sizeof(uuid_t));
1073     memcpy(cacheUUID, uuidBytes, sizeof(uuid_t));
1074     return true;
1075 }
1076
1077 const char* LaunchClosure::bootUUID() const
1078 {
1079     uint32_t size;
1080     return (char*)findAttributePayload(Type::bootUUID, &size);
1081 }
1082
1083 void LaunchClosure::forEachEnvVar(void (^handler)(const char* keyEqualValue, bool& stop)) const
1084 {
1085     forEachAttributePayload(Type::envVar, ^(const void* payload, uint32_t size, bool& stop) {
1086         handler((char*)payload, stop);
1087     });
1088 }
1089
1090 ImageNum LaunchClosure::libSystemImageNum() const
1091 {
1092     uint32_t size;
1093     const ImageNum* num = (ImageNum*)findAttributePayload(Type::libSystemNum, &size);
1094     assert(num != nullptr);
1095     assert(size == sizeof(ImageNum));
1096     return *num;
1097 }
1098
1099 void LaunchClosure::libDyldEntry(Image::ResolvedSymbolTarget& loc) const
1100 {
1101     uint32_t size;
1102     const Image::ResolvedSymbolTarget* data = (Image::ResolvedSymbolTarget*)findAttributePayload(Type::libDyldEntry, &size);
1103     assert(data != nullptr);
1104     assert(size == sizeof(Image::ResolvedSymbolTarget));
1105     loc = *data;
1106 }
1107
1108 bool LaunchClosure::mainEntry(Image::ResolvedSymbolTarget& mainLoc) const
1109 {
1110     uint32_t size;
1111     const Image::ResolvedSymbolTarget* data = (Image::ResolvedSymbolTarget*)findAttributePayload(Type::mainEntry, &size);
1112     if ( data == nullptr )
1113         return false;
1114     assert(size == sizeof(Image::ResolvedSymbolTarget));
1115     mainLoc = *data;
1116     return true;
1117 }
1118
1119 bool LaunchClosure::startEntry(Image::ResolvedSymbolTarget& startLoc) const
1120 {
1121     uint32_t size;
1122     const Image::ResolvedSymbolTarget* data = (Image::ResolvedSymbolTarget*)findAttributePayload(Type::startEntry, &size);
1123     if ( data == nullptr )
1124         return false;
1125     assert(size == sizeof(Image::ResolvedSymbolTarget));
1126     startLoc = *data;
1127     return true;
1128 }
1129
1130 const LaunchClosure::Flags& LaunchClosure::getFlags() const
1131 {
1132     uint32_t size;
1133     const Flags* flags = (Flags*)findAttributePayload(Type::closureFlags, &size);
1134     assert(flags != nullptr && "Closure missing Flags");
1135     return *flags;
1136 }
1137
1138 uint32_t LaunchClosure::initialLoadCount() const
1139 {
1140     return getFlags().initImageCount;
1141 }
1142
1143 bool LaunchClosure::usedAtPaths() const
1144 {
1145     return getFlags().usedAtPaths;
1146 }
1147
1148 bool LaunchClosure::usedFallbackPaths() const
1149 {
1150         return getFlags().usedFallbackPaths;
1151 }
1152
1153 bool LaunchClosure::hasInsertedLibraries() const
1154 {
1155     return getFlags().hasInsertedLibraries;
1156 }
1157
1158 bool LaunchClosure::hasInterposings() const
1159 {
1160     __block bool result = false;
1161
1162     forEachInterposingTuple(^(const InterposingTuple&, bool& stop) {
1163         result = true;
1164         stop = true;
1165     });
1166
1167     return result;
1168 }
1169
1170 void LaunchClosure::forEachInterposingTuple(void (^handler)(const InterposingTuple& tuple, bool& stop)) const
1171 {
1172         forEachAttributePayload(Type::interposeTuples, ^(const void* payload, uint32_t size, bool& stop) {
1173         assert((size % sizeof(InterposingTuple)) == 0);
1174         uintptr_t count = size / sizeof(InterposingTuple);
1175         const InterposingTuple* tuples = (InterposingTuple*)payload;
1176         for (uint32_t i=0; i < count && !stop; ++i) {
1177             handler(tuples[i], stop);
1178         }
1179         });
1180 }
1181 bool LaunchClosure::selectorHashTable(Array<Image::ObjCSelectorImage>& imageNums,
1182                                       const closure::ObjCSelectorOpt*& hashTable) const {
1183     uint32_t payloadSize = 0;
1184     const uint8_t* buffer = (const uint8_t*)findAttributePayload(Type::selectorTable, &payloadSize);
1185     if (buffer == nullptr)
1186         return false;
1187
1188     // Get count
1189     uint32_t count = 0;
1190     memcpy(&count, buffer, sizeof(uint32_t));
1191     buffer += sizeof(uint32_t);
1192
1193     // Get image nums
1194     imageNums = Array<Image::ObjCSelectorImage>((Image::ObjCSelectorImage*)buffer, count, count);
1195     buffer += sizeof(Image::ObjCSelectorImage) * count;
1196
1197     // Get hash table
1198     hashTable = (const closure::ObjCSelectorOpt*)buffer;
1199
1200     return true;
1201 }
1202
1203 bool LaunchClosure::classAndProtocolHashTables(Array<Image::ObjCClassImage>& imageNums,
1204                                                const ObjCClassOpt*& classHashTable,
1205                                                const ObjCClassOpt*& protocolHashTable) const {
1206     // The layout here is:
1207     //   uint32_t offset to class table (note this is 0 if there are no classes)
1208     //   uint32_t offset to protocol table (note this is 0 if there are no protocols)
1209     //   uint32_t num images
1210     //   ObjCClassImage[num images]
1211     //   class hash table
1212     //   [ padding to 4-byte alignment if needed
1213     //   protocol hash table
1214     //   [ padding to 4-byte alignment if needed
1215
1216     uint32_t payloadSize = 0;
1217     const uint8_t* buffer = (const uint8_t*)findAttributePayload(Type::classTable, &payloadSize);
1218     if (buffer == nullptr)
1219         return false;
1220
1221     uint32_t headerSize = sizeof(uint32_t) * 3;
1222
1223     uint32_t offsetToClassTable = 0;
1224     uint32_t offsetToProtocolTable = 0;
1225     uint32_t numImages = 0;
1226
1227     // Get the header
1228     memcpy(&offsetToClassTable,     buffer + 0, sizeof(uint32_t));
1229     memcpy(&offsetToProtocolTable,  buffer + 4, sizeof(uint32_t));
1230     memcpy(&numImages,              buffer + 8, sizeof(uint32_t));
1231
1232     // Get the image nums
1233     imageNums = Array<Image::ObjCClassImage>((Image::ObjCClassImage*)(buffer + headerSize), numImages, numImages);
1234
1235     // Get the class hash table if there is one
1236     if ( offsetToClassTable != 0 )
1237         classHashTable = (const ObjCClassOpt*)(buffer + offsetToClassTable);
1238
1239     // Write out out the protocol hash table if there is one
1240     if ( offsetToProtocolTable != 0 )
1241         protocolHashTable = (const ObjCClassOpt*)(buffer + offsetToProtocolTable);
1242
1243     return true;
1244 }
1245
1246 void LaunchClosure::duplicateClassesHashTable(const ObjCClassDuplicatesOpt*& duplicateClassesHashTable) const {
1247     uint32_t payloadSize = 0;
1248     const uint8_t* buffer = (const uint8_t*)findAttributePayload(Type::duplicateClassesTable, &payloadSize);
1249     if (buffer == nullptr)
1250         return;
1251
1252     duplicateClassesHashTable = (const ObjCClassDuplicatesOpt*)buffer;
1253 }
1254
1255 static void putHexNibble(uint8_t value, char*& p)
1256 {
1257     if ( value < 10 )
1258         *p++ = '0' + value;
1259     else
1260         *p++ = 'A' + value - 10;
1261 }
1262
1263 static void putHexByte(uint8_t value, char*& p)
1264 {
1265     value &= 0xFF;
1266     putHexNibble(value >> 4,   p);
1267     putHexNibble(value & 0x0F, p);
1268 }
1269
1270 static bool hashBootAndFileInfo(const char* mainExecutablePath, char hashString[32])
1271 {
1272     struct stat statbuf;
1273     if ( ::stat(mainExecutablePath, &statbuf) != 0)
1274         return false;
1275 #if !TARGET_OS_DRIVERKIT // Temp until core crypto is available
1276     const struct ccdigest_info* di = ccsha256_di();
1277     ccdigest_di_decl(di, hashTemp); // defines hashTemp array in stack
1278     ccdigest_init(di, hashTemp);
1279
1280     // put boot time into hash
1281     const uint64_t* bootTime = ((uint64_t*)_COMM_PAGE_BOOTTIME_USEC);
1282     ccdigest_update(di, hashTemp, sizeof(uint64_t), bootTime);
1283
1284     // put inode of executable into hash
1285     ccdigest_update(di, hashTemp, sizeof(statbuf.st_ino), &statbuf.st_ino);
1286
1287     // put mod-time of executable into hash
1288     ccdigest_update(di, hashTemp, sizeof(statbuf.st_mtime), &statbuf.st_mtime);
1289
1290     // complete hash computation and append as hex string
1291     uint8_t hashBits[32];
1292     ccdigest_final(di, hashTemp, hashBits);
1293     char* s = hashString;
1294     for (size_t i=0; i < sizeof(hashBits); ++i)
1295         putHexByte(hashBits[i], s);
1296     *s = '\0';
1297 #endif
1298     return true;
1299 }
1300
1301 bool LaunchClosure::buildClosureCachePath(const char* mainExecutablePath, char closurePath[], const char* tempDir,
1302                                           bool makeDirsIfMissing)
1303 {
1304     // <rdar://problem/47688842> dyld3 should only save closures to disk for containerized apps
1305     if ( strstr(tempDir, "/Containers/Data/") == nullptr )
1306         return false;
1307
1308     strlcpy(closurePath, tempDir, PATH_MAX);
1309     strlcat(closurePath, "/com.apple.dyld/", PATH_MAX);
1310
1311     // make sure dyld sub-dir exists
1312     if ( makeDirsIfMissing ) {
1313         struct stat statbuf;
1314         if ( ::stat(closurePath, &statbuf) != 0 ) {
1315             if ( ::mkdir(closurePath, S_IRWXU) != 0 )
1316                 return false;
1317         }
1318     }
1319
1320     const char* leafName = strrchr(mainExecutablePath, '/');
1321     if ( leafName == nullptr )
1322         leafName = mainExecutablePath;
1323     else
1324         ++leafName;
1325     strlcat(closurePath, leafName, PATH_MAX);
1326     strlcat(closurePath, "-", PATH_MAX);
1327
1328     if ( !hashBootAndFileInfo(mainExecutablePath, &closurePath[strlen(closurePath)]) )
1329         return false;
1330
1331     strlcat(closurePath, ".closure", PATH_MAX);
1332     return true;
1333 }
1334
1335 ////////////////////////////  ObjCStringTable ////////////////////////////////////////
1336
1337 uint32_t ObjCStringTable::hash(const char *key, size_t keylen) const
1338 {
1339     uint64_t val = objc_opt::lookup8((uint8_t*)key, keylen, salt);
1340     uint32_t index = (uint32_t)((shift == 64) ? 0 : (val>>shift)) ^ scramble[tab[val&mask]];
1341     return index;
1342 }
1343
1344 const char* ObjCStringTable::getString(const char* selName, const Array<uintptr_t>& baseAddresses) const {
1345     StringTarget target = getPotentialTarget(selName);
1346     if (target == sentinelTarget)
1347         return nullptr;
1348
1349     dyld3::closure::Image::ObjCImageOffset imageAndOffset;
1350     imageAndOffset.raw = target;
1351
1352     uintptr_t sectionBaseAddress = baseAddresses[imageAndOffset.imageIndex];
1353
1354     const char* value = (const char*)(sectionBaseAddress + imageAndOffset.imageOffset);
1355     if (!strcmp(selName, value))
1356         return value;
1357     return nullptr;
1358 }
1359
1360 ////////////////////////////  ObjCSelectorOpt ////////////////////////////////////////
1361 bool ObjCSelectorOpt::getStringLocation(uint32_t index, const Array<closure::Image::ObjCSelectorImage>& selImages,
1362                                         ImageNum& imageNum, uint64_t& vmOffset) const {
1363     if ( index >= capacity )
1364         return false;
1365
1366     StringTarget target = targets()[index];
1367     if ( target == indexNotFound )
1368         return false;
1369
1370     dyld3::closure::Image::ObjCImageOffset imageAndOffset;
1371     imageAndOffset.raw = target;
1372
1373     imageNum = selImages[imageAndOffset.imageIndex].imageNum;
1374     vmOffset = selImages[imageAndOffset.imageIndex].offset + imageAndOffset.imageOffset;
1375     return true;;
1376 }
1377
1378 void ObjCSelectorOpt::forEachString(const Array<Image::ObjCSelectorImage>& selectorImages,
1379                                     void (^callback)(uint64_t selVMOffset, ImageNum imageNum)) const {
1380     dyld3::Array<StringTarget> stringTargets = targets();
1381     for (unsigned i = 0; i != capacity; ++i) {
1382         dyld3::closure::Image::ObjCImageOffset imageAndOffset;
1383         imageAndOffset.raw = stringTargets[i];
1384
1385         if (imageAndOffset.raw == sentinelTarget)
1386             continue;
1387
1388         callback(selectorImages[imageAndOffset.imageIndex].offset + imageAndOffset.imageOffset,
1389                  selectorImages[imageAndOffset.imageIndex].imageNum);
1390     }
1391 }
1392
1393 ////////////////////////////  ObjCClassOpt ////////////////////////////////////////
1394
1395 void ObjCClassOpt::forEachClass(const char* className, const Array<std::pair<uintptr_t, uintptr_t>>& nameAndDataBaseAddresses,
1396                                 void (^callback)(void* classPtr, bool isLoaded, bool* stop)) const {
1397     uint32_t index = getIndex(className);
1398     if ( index == closure::ObjCStringTable::indexNotFound )
1399         return;
1400
1401     StringTarget target = targets()[index];
1402     if ( target == sentinelTarget )
1403         return;
1404
1405     // We have a potential target.  First check if the name is an exact match given the hash matched
1406     closure::Image::ObjCImageOffset classNameImageAndOffset;
1407     classNameImageAndOffset.raw = target;
1408
1409     uintptr_t nameBaseAddress = 0;
1410     uintptr_t dataBaseAddress = 0;
1411     std::tie(nameBaseAddress, dataBaseAddress) = nameAndDataBaseAddresses[classNameImageAndOffset.imageIndex];
1412
1413     const char* value = (const char*)(nameBaseAddress + classNameImageAndOffset.imageOffset);
1414     if ( strcmp(className, value) != 0 )
1415         return;
1416
1417     // The name matched so now call the handler on all the classes for this name
1418     Array<closure::ObjCClassOpt::ClassTarget> classOffsetsArray = classOffsets();
1419     Array<closure::ObjCClassOpt::ClassTarget> duplicatesArray = duplicateOffsets(duplicateCount());
1420
1421     const closure::ObjCClassOpt::ClassTarget& classOffset = classOffsetsArray[index];
1422     if (classOffset.classData.isDuplicate == 0) {
1423         // This class has a single implementation
1424         void* classImpl = (void*)(dataBaseAddress + classOffset.classData.imageOffset);
1425         bool stop = false;
1426         callback(classImpl, true, &stop);
1427     } else {
1428         // This class has mulitple implementations
1429         uint32_t duplicateCount = classOffset.duplicateData.count;
1430         uint32_t duplicateStartIndex = classOffset.duplicateData.index;
1431         for (uint32_t dupeIndex = 0; dupeIndex != duplicateCount; ++dupeIndex) {
1432             closure::ObjCClassOpt::ClassTarget& duplicateClass = duplicatesArray[duplicateStartIndex + dupeIndex];
1433
1434             std::tie(nameBaseAddress, dataBaseAddress) = nameAndDataBaseAddresses[duplicateClass.classData.imageIndex];
1435             void* classImpl = (void*)(dataBaseAddress + duplicateClass.classData.imageOffset);
1436             bool            stop                = false;
1437             callback(classImpl, true, &stop);
1438             if (stop)
1439                 break;
1440         }
1441     }
1442 }
1443
1444 void ObjCClassOpt::forEachClass(const Array<Image::ObjCClassImage>& classImages,
1445                                 void (^nameCallback)(uint64_t classNameVMOffset, ImageNum imageNum),
1446                                 void (^implCallback)(uint64_t classVMOffset, ImageNum imageNum)) const {
1447
1448     dyld3::Array<StringTarget> stringTargets = targets();
1449     dyld3::Array<ObjCClassOpt::ClassTarget> classOffsetsArray = classOffsets();
1450     dyld3::Array<ObjCClassOpt::ClassTarget> duplicatesArray = duplicateOffsets(duplicateCount());
1451     for (unsigned i = 0; i != capacity; ++i) {
1452         dyld3::closure::Image::ObjCImageOffset classNameImageAndOffset;
1453         classNameImageAndOffset.raw = stringTargets[i];
1454
1455         if (classNameImageAndOffset.raw == sentinelTarget)
1456             continue;
1457
1458         nameCallback(classImages[classNameImageAndOffset.imageIndex].offsetOfClassNames + classNameImageAndOffset.imageOffset,
1459                      classImages[classNameImageAndOffset.imageIndex].imageNum);
1460
1461         // Walk each class for this key
1462         const ObjCClassOpt::ClassTarget& classOffset = classOffsetsArray[i];
1463         if (classOffset.classData.isDuplicate == 0) {
1464             // This class has a single implementation
1465             implCallback(classImages[classOffset.classData.imageIndex].offsetOfClasses + classOffset.classData.imageOffset,
1466                          classImages[classOffset.classData.imageIndex].imageNum);
1467         } else {
1468             // This class has mulitple implementations
1469             uint32_t duplicateCount = classOffset.duplicateData.count;
1470             uint32_t duplicateStartIndex = classOffset.duplicateData.index;
1471             for (uint32_t dupeIndex = 0; dupeIndex != duplicateCount; ++dupeIndex) {
1472                 ObjCClassOpt::ClassTarget& duplicateClass = duplicatesArray[duplicateStartIndex + dupeIndex];
1473                 implCallback(classImages[duplicateClass.classData.imageIndex].offsetOfClasses + duplicateClass.classData.imageOffset,
1474                              classImages[duplicateClass.classData.imageIndex].imageNum);
1475             }
1476         }
1477     }
1478 }
1479
1480 ////////////////////////////  ObjCClassDuplicatesOpt ////////////////////////////////////////
1481
1482 bool ObjCClassDuplicatesOpt::getClassLocation(const char* className, const objc_opt::objc_opt_t* objCOpt, void*& classImpl) const {
1483     uint32_t potentialTarget = getPotentialTarget(className);
1484     if (potentialTarget == sentinelTarget)
1485         return false;
1486
1487     objc_opt::objc_clsopt_t* clsOpt = objCOpt->clsopt();
1488
1489     Image::ObjCDuplicateClass duplicateClass;
1490     duplicateClass.raw = potentialTarget;
1491
1492     const char* sharedCacheClassName = clsOpt->getClassNameForIndex(duplicateClass.sharedCacheClassOptIndex);
1493     if (strcmp(className, sharedCacheClassName) != 0)
1494         return false;
1495
1496     classImpl = clsOpt->getClassForIndex(duplicateClass.sharedCacheClassOptIndex, duplicateClass.sharedCacheClassDuplicateIndex);
1497     return true;
1498 }
1499
1500 void ObjCClassDuplicatesOpt::forEachClass(void (^callback)(Image::ObjCDuplicateClass duplicateClass)) const {
1501     dyld3::Array<StringTarget> stringTargets = targets();
1502     for (unsigned i = 0; i != capacity; ++i) {
1503         StringTarget target = stringTargets[i];
1504         if ( target == sentinelTarget )
1505             continue;
1506         Image::ObjCDuplicateClass duplicateClass;
1507         duplicateClass.raw = (uint32_t)target;
1508         callback(duplicateClass);
1509     }
1510 }
1511
1512
1513 } // namespace closure
1514 } // namespace dyld3
1515
1516
1517