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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 | /* * Copyright (c) 2017 Apple Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ #include <TargetConditionals.h> #include "Defines.h" #if !TARGET_OS_EXCLAVEKIT #include <sys/types.h> #include <sys/stat.h> #include <sys/errno.h> #include <sys/mman.h> #include <mach/mach.h> #include <fcntl.h> #include <unistd.h> #endif #include <stdlib.h> #include <stdio.h> #include <assert.h> #include <mach-o/nlist.h> #if !TARGET_OS_EXCLAVEKIT extern "C" { #include <corecrypto/ccdigest.h> #include <corecrypto/ccsha1.h> #include <corecrypto/ccsha2.h> } #endif #include "Header.h" #include "MachOFile.h" #include "MachOLoaded.h" #include "CodeSigningTypes.h" using mach_o::Header; namespace dyld3 { void MachOLoaded::getLinkEditLoadCommands(Diagnostics& diag, LinkEditInfo& result) const { result.dyldInfo = nullptr; result.exportsTrie = nullptr; result.chainedFixups = nullptr; result.symTab = nullptr; result.dynSymTab = nullptr; result.splitSegInfo = nullptr; result.functionStarts = nullptr; result.dataInCode = nullptr; result.codeSig = nullptr; __block bool hasUUID = false; __block bool hasMinVersion = false; __block bool hasEncrypt = false; forEachLoadCommand(diag, ^(const load_command* cmd, bool& stop) { switch ( cmd->cmd ) { case LC_DYLD_INFO: case LC_DYLD_INFO_ONLY: if ( cmd->cmdsize != sizeof(dyld_info_command) ) diag.error("LC_DYLD_INFO load command size wrong"); else if ( result.dyldInfo != nullptr ) diag.error("multiple LC_DYLD_INFO load commands"); result.dyldInfo = (dyld_info_command*)cmd; break; case LC_DYLD_EXPORTS_TRIE: if ( cmd->cmdsize != sizeof(linkedit_data_command) ) diag.error("LC_DYLD_EXPORTS_TRIE load command size wrong"); else if ( result.exportsTrie != nullptr ) diag.error("multiple LC_DYLD_EXPORTS_TRIE load commands"); result.exportsTrie = (linkedit_data_command*)cmd; break; case LC_DYLD_CHAINED_FIXUPS: if ( cmd->cmdsize != sizeof(linkedit_data_command) ) diag.error("LC_DYLD_CHAINED_FIXUPS load command size wrong"); else if ( result.chainedFixups != nullptr ) diag.error("multiple LC_DYLD_CHAINED_FIXUPS load commands"); result.chainedFixups = (linkedit_data_command*)cmd; break; case LC_SYMTAB: if ( cmd->cmdsize != sizeof(symtab_command) ) diag.error("LC_SYMTAB load command size wrong"); else if ( result.symTab != nullptr ) diag.error("multiple LC_SYMTAB load commands"); result.symTab = (symtab_command*)cmd; break; case LC_DYSYMTAB: if ( cmd->cmdsize != sizeof(dysymtab_command) ) diag.error("LC_DYSYMTAB load command size wrong"); else if ( result.dynSymTab != nullptr ) diag.error("multiple LC_DYSYMTAB load commands"); result.dynSymTab = (dysymtab_command*)cmd; break; case LC_SEGMENT_SPLIT_INFO: if ( cmd->cmdsize != sizeof(linkedit_data_command) ) diag.error("LC_SEGMENT_SPLIT_INFO load command size wrong"); else if ( result.splitSegInfo != nullptr ) diag.error("multiple LC_SEGMENT_SPLIT_INFO load commands"); result.splitSegInfo = (linkedit_data_command*)cmd; break; case LC_FUNCTION_STARTS: if ( cmd->cmdsize != sizeof(linkedit_data_command) ) diag.error("LC_FUNCTION_STARTS load command size wrong"); else if ( result.functionStarts != nullptr ) diag.error("multiple LC_FUNCTION_STARTS load commands"); result.functionStarts = (linkedit_data_command*)cmd; break; case LC_DATA_IN_CODE: if ( cmd->cmdsize != sizeof(linkedit_data_command) ) diag.error("LC_DATA_IN_CODE load command size wrong"); else if ( result.dataInCode != nullptr ) diag.error("multiple LC_DATA_IN_CODE load commands"); result.dataInCode = (linkedit_data_command*)cmd; break; case LC_CODE_SIGNATURE: if ( cmd->cmdsize != sizeof(linkedit_data_command) ) diag.error("LC_CODE_SIGNATURE load command size wrong"); else if ( result.codeSig != nullptr ) diag.error("multiple LC_CODE_SIGNATURE load commands"); result.codeSig = (linkedit_data_command*)cmd; break; case LC_UUID: if ( cmd->cmdsize != sizeof(uuid_command) ) diag.error("LC_UUID load command size wrong"); else if ( hasUUID ) diag.error("multiple LC_UUID load commands"); hasUUID = true; break; case LC_VERSION_MIN_IPHONEOS: case LC_VERSION_MIN_MACOSX: case LC_VERSION_MIN_TVOS: case LC_VERSION_MIN_WATCHOS: if ( cmd->cmdsize != sizeof(version_min_command) ) diag.error("LC_VERSION_* load command size wrong"); else if ( hasMinVersion ) diag.error("multiple LC_VERSION_MIN_* load commands"); hasMinVersion = true; break; case LC_BUILD_VERSION: if ( cmd->cmdsize != (sizeof(build_version_command) + ((build_version_command*)cmd)->ntools * sizeof(build_tool_version)) ) diag.error("LC_BUILD_VERSION load command size wrong"); break; case LC_ENCRYPTION_INFO: if ( cmd->cmdsize != sizeof(encryption_info_command) ) diag.error("LC_ENCRYPTION_INFO load command size wrong"); else if ( hasEncrypt ) diag.error("multiple LC_ENCRYPTION_INFO load commands"); else if ( is64() ) diag.error("LC_ENCRYPTION_INFO found in 64-bit mach-o"); hasEncrypt = true; break; case LC_ENCRYPTION_INFO_64: if ( cmd->cmdsize != sizeof(encryption_info_command_64) ) diag.error("LC_ENCRYPTION_INFO_64 load command size wrong"); else if ( hasEncrypt ) diag.error("multiple LC_ENCRYPTION_INFO_64 load commands"); else if ( !is64() ) diag.error("LC_ENCRYPTION_INFO_64 found in 32-bit mach-o"); hasEncrypt = true; break; } }); if ( diag.noError() && (result.dynSymTab != nullptr) && (result.symTab == nullptr) ) diag.error("LC_DYSYMTAB but no LC_SYMTAB load command"); } void MachOLoaded::getLinkEditPointers(Diagnostics& diag, LinkEditInfo& result) const { getLinkEditLoadCommands(diag, result); if ( diag.noError() ) getLayoutInfo(result.layout); } const uint8_t* MachOLoaded::getExportsTrie(const LinkEditInfo& leInfo, uint64_t& trieSize) const { if ( leInfo.exportsTrie != nullptr) { trieSize = leInfo.exportsTrie->datasize; uint64_t offsetInLinkEdit = leInfo.exportsTrie->dataoff - leInfo.layout.linkeditFileOffset; return (uint8_t*)this + (leInfo.layout.linkeditUnslidVMAddr - leInfo.layout.textUnslidVMAddr) + offsetInLinkEdit; } else if ( leInfo.dyldInfo != nullptr ) { trieSize = leInfo.dyldInfo->export_size; uint64_t offsetInLinkEdit = leInfo.dyldInfo->export_off - leInfo.layout.linkeditFileOffset; return (uint8_t*)this + (leInfo.layout.linkeditUnslidVMAddr - leInfo.layout.textUnslidVMAddr) + offsetInLinkEdit; } trieSize = 0; return nullptr; } void MachOLoaded::getLayoutInfo(LayoutInfo& result) const { ((const Header*)this)->forEachSegment(^(const Header::SegmentInfo& info, bool& stop) { if ( info.segmentName == "__TEXT" ) { result.textUnslidVMAddr = (uintptr_t)info.vmaddr; result.slide = (uintptr_t)(((uint64_t)this) - info.vmaddr); } else if ( info.segmentName == "__LINKEDIT" ) { result.linkeditUnslidVMAddr = (uintptr_t)info.vmaddr; result.linkeditFileOffset = (uint32_t)info.fileOffset; result.linkeditFileSize = (uint32_t)info.fileSize; result.linkeditSegIndex = info.segmentIndex; } result.lastSegIndex = info.segmentIndex; }); } //#if BUILDING_LIBDYLD // this is only used by dlsym() at runtime. All other binding is done when the closure is built. bool MachOLoaded::hasExportedSymbol(const char* symbolName, DependentToMachOLoaded finder, void** result, bool* resultPointsToInstructions) const { typedef void* (*ResolverFunc)(void); ResolverFunc resolver; Diagnostics diag; FoundSymbol foundInfo; if ( findExportedSymbol(diag, symbolName, false, foundInfo, finder) ) { switch ( foundInfo.kind ) { case FoundSymbol::Kind::headerOffset: { *result = (uint8_t*)foundInfo.foundInDylib + foundInfo.value; *resultPointsToInstructions = false; int64_t slide = foundInfo.foundInDylib->getSlide(); foundInfo.foundInDylib->forEachSection(^(const Header::SectionInfo& sectInfo, bool& stop) { uint64_t sectStartAddr = sectInfo.address + slide; uint64_t sectEndAddr = sectStartAddr + sectInfo.size; if ( ((uint64_t)*result >= sectStartAddr) && ((uint64_t)*result < sectEndAddr) ) { *resultPointsToInstructions = (sectInfo.flags & S_ATTR_PURE_INSTRUCTIONS) || (sectInfo.flags & S_ATTR_SOME_INSTRUCTIONS); stop = true; } }); break; } case FoundSymbol::Kind::absolute: *result = (void*)(long)foundInfo.value; *resultPointsToInstructions = false; break; case FoundSymbol::Kind::resolverOffset: // foundInfo.value contains "stub". // in dlsym() we want to call resolver function to get final function address resolver = (ResolverFunc)((uint8_t*)foundInfo.foundInDylib + foundInfo.resolverFuncOffset); *result = (*resolver)(); // FIXME: Set this properly *resultPointsToInstructions = true; break; } return true; } return false; } //#endif // BUILDING_LIBDYLD bool MachOLoaded::findExportedSymbol(Diagnostics& diag, const char* symbolName, bool weakImport, FoundSymbol& foundInfo, DependentToMachOLoaded findDependent) const { LinkEditInfo leInfo; getLinkEditPointers(diag, leInfo); if ( diag.hasError() ) return false; uint64_t trieSize; if ( const uint8_t* trieStart = getExportsTrie(leInfo, trieSize) ) { const uint8_t* trieEnd = trieStart + trieSize; const uint8_t* node = trieWalk(diag, trieStart, trieEnd, symbolName); if ( node == nullptr ) { // symbol not exported from this image. Seach any re-exported dylibs __block unsigned depIndex = 0; __block bool foundInReExportedDylib = false; forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool& stop) { if ( isReExport && findDependent ) { if ( const MachOLoaded* depMH = findDependent(this, depIndex) ) { if ( depMH->findExportedSymbol(diag, symbolName, weakImport, foundInfo, findDependent) ) { stop = true; foundInReExportedDylib = true; } } } ++depIndex; }); return foundInReExportedDylib; } const uint8_t* p = node; const uint64_t flags = read_uleb128(diag, p, trieEnd); if ( flags & EXPORT_SYMBOL_FLAGS_REEXPORT ) { if ( !findDependent ) return false; // re-export from another dylib, lookup there const uint64_t ordinal = read_uleb128(diag, p, trieEnd); const char* importedName = (char*)p; if ( importedName[0] == '\0' ) importedName = symbolName; if ( (ordinal == 0) || (ordinal > dependentDylibCount()) ) { diag.error("re-export ordinal %lld out of range for %s", ordinal, symbolName); return false; } uint32_t depIndex = (uint32_t)(ordinal-1); if ( const MachOLoaded* depMH = findDependent(this, depIndex) ) { return depMH->findExportedSymbol(diag, importedName, weakImport, foundInfo, findDependent); } else if (weakImport) { return false; } else { diag.error("dependent dylib %lld not found for re-exported symbol %s", ordinal, symbolName); return false; } } foundInfo.kind = FoundSymbol::Kind::headerOffset; foundInfo.isThreadLocal = false; foundInfo.isWeakDef = false; foundInfo.foundInDylib = this; foundInfo.value = read_uleb128(diag, p, trieEnd); foundInfo.resolverFuncOffset = 0; foundInfo.foundSymbolName = symbolName; if ( diag.hasError() ) return false; switch ( flags & EXPORT_SYMBOL_FLAGS_KIND_MASK ) { case EXPORT_SYMBOL_FLAGS_KIND_REGULAR: if ( flags & EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER ) { foundInfo.kind = FoundSymbol::Kind::headerOffset; foundInfo.resolverFuncOffset = (uint32_t)read_uleb128(diag, p, trieEnd); } else { foundInfo.kind = FoundSymbol::Kind::headerOffset; } if ( flags & EXPORT_SYMBOL_FLAGS_WEAK_DEFINITION ) foundInfo.isWeakDef = true; break; case EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL: foundInfo.isThreadLocal = true; break; case EXPORT_SYMBOL_FLAGS_KIND_ABSOLUTE: foundInfo.kind = FoundSymbol::Kind::absolute; break; default: diag.error("unsupported exported symbol kind. flags=%llu at node offset=0x%0lX", flags, (long)(node-trieStart)); return false; } return true; } else { // this is an old binary (before macOS 10.6), scan the symbol table foundInfo.foundInDylib = nullptr; forEachGlobalSymbol(diag, ^(const char* aSymbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, bool& stop) { if ( strcmp(aSymbolName, symbolName) == 0 ) { foundInfo.kind = FoundSymbol::Kind::headerOffset; foundInfo.isThreadLocal = false; foundInfo.foundInDylib = this; foundInfo.value = n_value - leInfo.layout.textUnslidVMAddr; foundInfo.resolverFuncOffset = 0; foundInfo.foundSymbolName = symbolName; stop = true; } }); if ( foundInfo.foundInDylib == nullptr ) { // symbol not exported from this image. Search any re-exported dylibs __block unsigned depIndex = 0; forEachDependentDylib(^(const char* loadPath, bool isWeak, bool isReExport, bool isUpward, uint32_t compatVersion, uint32_t curVersion, bool& stop) { if ( isReExport && findDependent ) { if ( const MachOLoaded* depMH = findDependent(this, depIndex) ) { if ( depMH->findExportedSymbol(diag, symbolName, weakImport, foundInfo, findDependent) ) { stop = true; } } } ++depIndex; }); } return (foundInfo.foundInDylib != nullptr); } } intptr_t MachOLoaded::getSlide() const { Diagnostics diag; __block intptr_t slide = 0; forEachLoadCommand(diag, ^(const load_command* cmd, bool& stop) { if ( cmd->cmd == LC_SEGMENT_64 ) { const segment_command_64* seg = (segment_command_64*)cmd; if ( strcmp(seg->segname, "__TEXT") == 0 ) { slide = (uintptr_t)(((uint64_t)this) - seg->vmaddr); stop = true; } } else if ( cmd->cmd == LC_SEGMENT ) { const segment_command* seg = (segment_command*)cmd; if ( strcmp(seg->segname, "__TEXT") == 0 ) { slide = (uintptr_t)(((uint64_t)this) - seg->vmaddr); stop = true; } } }); diag.assertNoError(); // any malformations in the file should have been caught by earlier validate() call return slide; } const uint8_t* MachOLoaded::getLinkEditContent(const LayoutInfo& info, uint32_t fileOffset) const { uint32_t offsetInLinkedit = fileOffset - info.linkeditFileOffset; uintptr_t linkeditStartAddr = info.linkeditUnslidVMAddr + info.slide; return (uint8_t*)(linkeditStartAddr + offsetInLinkedit); } void MachOLoaded::forEachGlobalSymbol(Diagnostics& diag, void (^callback)(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, bool& stop)) const { LinkEditInfo leInfo; getLinkEditPointers(diag, leInfo); if ( diag.hasError() ) return; const bool is64Bit = is64(); if ( leInfo.symTab != nullptr ) { uint32_t globalsStartIndex = 0; uint32_t globalsCount = leInfo.symTab->nsyms; if ( leInfo.dynSymTab != nullptr ) { globalsStartIndex = leInfo.dynSymTab->iextdefsym; globalsCount = leInfo.dynSymTab->nextdefsym; } uint32_t maxStringOffset = leInfo.symTab->strsize; const char* stringPool = (char*)getLinkEditContent(leInfo.layout, leInfo.symTab->stroff); const struct nlist* symbols = (struct nlist*) (getLinkEditContent(leInfo.layout, leInfo.symTab->symoff)); const struct nlist_64* symbols64 = (struct nlist_64*)symbols; bool stop = false; for (uint32_t i=0; (i < globalsCount) && !stop; ++i) { if ( is64Bit ) { const struct nlist_64& sym = symbols64[globalsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( (sym.n_type & N_EXT) && ((sym.n_type & N_TYPE) == N_SECT) && ((sym.n_type & N_STAB) == 0) ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } else { const struct nlist& sym = symbols[globalsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( (sym.n_type & N_EXT) && ((sym.n_type & N_TYPE) == N_SECT) && ((sym.n_type & N_STAB) == 0) ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } } } } void MachOLoaded::forEachLocalSymbol(Diagnostics& diag, void (^callback)(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, bool& stop)) const { LinkEditInfo leInfo; getLinkEditPointers(diag, leInfo); if ( diag.hasError() ) return; const bool is64Bit = is64(); if ( leInfo.symTab != nullptr ) { uint32_t localsStartIndex = 0; uint32_t localsCount = leInfo.symTab->nsyms; if ( leInfo.dynSymTab != nullptr ) { localsStartIndex = leInfo.dynSymTab->ilocalsym; localsCount = leInfo.dynSymTab->nlocalsym; } uint32_t maxStringOffset = leInfo.symTab->strsize; const char* stringPool = (char*)getLinkEditContent(leInfo.layout, leInfo.symTab->stroff); const struct nlist* symbols = (struct nlist*) (getLinkEditContent(leInfo.layout, leInfo.symTab->symoff)); const struct nlist_64* symbols64 = (struct nlist_64*)(getLinkEditContent(leInfo.layout, leInfo.symTab->symoff)); bool stop = false; for (uint32_t i=0; (i < localsCount) && !stop; ++i) { if ( is64Bit ) { const struct nlist_64& sym = symbols64[localsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( ((sym.n_type & N_EXT) == 0) && ((sym.n_type & N_TYPE) == N_SECT) && ((sym.n_type & N_STAB) == 0) ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } else { const struct nlist& sym = symbols[localsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( ((sym.n_type & N_EXT) == 0) && ((sym.n_type & N_TYPE) == N_SECT) && ((sym.n_type & N_STAB) == 0) ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } } } } void MachOLoaded::forEachImportedSymbol(Diagnostics& diag, void (^callback)(const char* symbolName, uint64_t n_value, uint8_t n_type, uint8_t n_sect, uint16_t n_desc, bool& stop)) const { LinkEditInfo leInfo; getLinkEditPointers(diag, leInfo); if ( diag.hasError() ) return; const bool is64Bit = is64(); if ( leInfo.symTab != nullptr ) { uint32_t globalsStartIndex = 0; uint32_t globalsCount = leInfo.symTab->nsyms; if ( leInfo.dynSymTab != nullptr ) { globalsStartIndex = leInfo.dynSymTab->iundefsym; globalsCount = leInfo.dynSymTab->nundefsym; } uint32_t maxStringOffset = leInfo.symTab->strsize; const char* stringPool = (char*)getLinkEditContent(leInfo.layout, leInfo.symTab->stroff); const struct nlist* symbols = (struct nlist*) (getLinkEditContent(leInfo.layout, leInfo.symTab->symoff)); const struct nlist_64* symbols64 = (struct nlist_64*)symbols; bool stop = false; for (uint32_t i=0; (i < globalsCount) && !stop; ++i) { if ( is64Bit ) { const struct nlist_64& sym = symbols64[globalsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( (sym.n_type & N_TYPE) == N_UNDF ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } else { const struct nlist& sym = symbols[globalsStartIndex+i]; if ( sym.n_un.n_strx > maxStringOffset ) continue; if ( (sym.n_type & N_TYPE) == N_UNDF ) callback(&stringPool[sym.n_un.n_strx], sym.n_value, sym.n_type, sym.n_sect, sym.n_desc, stop); } } } } std::string_view MachOLoaded::segmentName(uint32_t targetSegIndex) const { __block std::string_view result; ((const Header*)this)->forEachSegment(^(const Header::SegmentInfo& info, bool& stop) { if ( targetSegIndex == info.segmentIndex ) { result = info.segmentName; stop = true; } }); return result; } bool MachOLoaded::findClosestFunctionStart(uint64_t address, uint64_t* functionStartAddress) const { Diagnostics diag; LinkEditInfo leInfo; getLinkEditPointers(diag, leInfo); if ( diag.hasError() ) return false; if ( leInfo.functionStarts == nullptr ) return false; const uint8_t* starts = getLinkEditContent(leInfo.layout, leInfo.functionStarts->dataoff); const uint8_t* startsEnd = starts + leInfo.functionStarts->datasize; uint64_t lastAddr = (uint64_t)(long)this; uint64_t runningAddr = lastAddr; while (diag.noError()) { uint64_t value = read_uleb128(diag, starts, startsEnd); if ( value == 0 ) break; lastAddr = runningAddr; runningAddr += value; //fprintf(stderr, " addr=0x%08llX\n", runningAddr); if ( runningAddr > address ) { *functionStartAddress = lastAddr; return true; } }; return false; } void MachOLoaded::forEachFunctionStart(void (^callback)(uint64_t runtimeOffset)) const { Diagnostics diag; LinkEditInfo leInfo; getLinkEditPointers(diag, leInfo); if ( diag.hasError() ) return; if ( leInfo.functionStarts == nullptr ) return; const uint8_t* starts = getLinkEditContent(leInfo.layout, leInfo.functionStarts->dataoff); const uint8_t* startsEnd = starts + leInfo.functionStarts->datasize; uint64_t runtimeOffset = 0; while (diag.noError()) { uint64_t value = read_uleb128(diag, starts, startsEnd); if ( value == 0 ) break; runtimeOffset += value; callback(runtimeOffset); }; } bool MachOLoaded::findClosestSymbol(uint64_t address, const char** symbolName, uint64_t* symbolAddr) const { Diagnostics diag; LinkEditInfo leInfo; getLinkEditPointers(diag, leInfo); if ( diag.hasError() ) return false; if ( (leInfo.symTab == nullptr) || (leInfo.dynSymTab == nullptr) ) return false; uint64_t targetUnslidAddress = address - leInfo.layout.slide; // find section index the address is in to validate n_sect __block uint32_t sectionIndexForTargetAddress = 0; forEachSection(^(const Header::SectionInfo& sectInfo, bool& stop) { ++sectionIndexForTargetAddress; if ( (sectInfo.address <= targetUnslidAddress) && (targetUnslidAddress < sectInfo.address+sectInfo.size) ) { stop = true; } }); uint32_t maxStringOffset = leInfo.symTab->strsize; const char* stringPool = (char*)getLinkEditContent(leInfo.layout, leInfo.symTab->stroff); const struct nlist* symbols = (struct nlist*) (getLinkEditContent(leInfo.layout, leInfo.symTab->symoff)); if ( is64() ) { const struct nlist_64* symbols64 = (struct nlist_64*)symbols; const struct nlist_64* bestSymbol = nullptr; // first walk all global symbols const struct nlist_64* const globalsStart = &symbols64[leInfo.dynSymTab->iextdefsym]; const struct nlist_64* const globalsEnd = &globalsStart[leInfo.dynSymTab->nextdefsym]; for (const struct nlist_64* s = globalsStart; s < globalsEnd; ++s) { if ( (s->n_type & N_TYPE) == N_SECT ) { if ( bestSymbol == nullptr ) { if ( (s->n_value <= targetUnslidAddress) && (s->n_sect == sectionIndexForTargetAddress) ) bestSymbol = s; } else if ( (s->n_value <= targetUnslidAddress) && (bestSymbol->n_value < s->n_value) && (s->n_sect == sectionIndexForTargetAddress) ) { bestSymbol = s; } } } // next walk all local symbols const struct nlist_64* const localsStart = &symbols64[leInfo.dynSymTab->ilocalsym]; const struct nlist_64* const localsEnd = &localsStart[leInfo.dynSymTab->nlocalsym]; for (const struct nlist_64* s = localsStart; s < localsEnd; ++s) { if ( ((s->n_type & N_TYPE) == N_SECT) && ((s->n_type & N_STAB) == 0) ) { if ( bestSymbol == nullptr ) { if ( (s->n_value <= targetUnslidAddress) && (s->n_sect == sectionIndexForTargetAddress) ) bestSymbol = s; } else if ( (s->n_value <= targetUnslidAddress) && (bestSymbol->n_value < s->n_value) && (s->n_sect == sectionIndexForTargetAddress) ) { bestSymbol = s; } } } if ( bestSymbol != NULL ) { *symbolAddr = bestSymbol->n_value + leInfo.layout.slide; if ( bestSymbol->n_un.n_strx < maxStringOffset ) *symbolName = &stringPool[bestSymbol->n_un.n_strx]; return true; } } else { const struct nlist* bestSymbol = nullptr; // first walk all global symbols const struct nlist* const globalsStart = &symbols[leInfo.dynSymTab->iextdefsym]; const struct nlist* const globalsEnd = &globalsStart[leInfo.dynSymTab->nextdefsym]; for (const struct nlist* s = globalsStart; s < globalsEnd; ++s) { if ( (s->n_type & N_TYPE) == N_SECT ) { if ( bestSymbol == nullptr ) { if ( (s->n_value <= targetUnslidAddress) && (s->n_sect == sectionIndexForTargetAddress) ) bestSymbol = s; } else if ( (s->n_value <= targetUnslidAddress) && (bestSymbol->n_value < s->n_value) && (s->n_sect == sectionIndexForTargetAddress) ) { bestSymbol = s; } } } // next walk all local symbols const struct nlist* const localsStart = &symbols[leInfo.dynSymTab->ilocalsym]; const struct nlist* const localsEnd = &localsStart[leInfo.dynSymTab->nlocalsym]; for (const struct nlist* s = localsStart; s < localsEnd; ++s) { if ( ((s->n_type & N_TYPE) == N_SECT) && ((s->n_type & N_STAB) == 0) ) { if ( bestSymbol == nullptr ) { if ( (s->n_value <= targetUnslidAddress) && (s->n_sect == sectionIndexForTargetAddress) ) bestSymbol = s; } else if ( (s->n_value <= targetUnslidAddress) && (bestSymbol->n_value < s->n_value) && (s->n_sect == sectionIndexForTargetAddress) ) { bestSymbol = s; } } } if ( bestSymbol != nullptr ) { *symbolAddr = bestSymbol->n_value + leInfo.layout.slide; if ( bestSymbol->n_un.n_strx < maxStringOffset ) *symbolName = &stringPool[bestSymbol->n_un.n_strx]; return true; } } return false; } const void* MachOLoaded::findSectionContent(const char* segName, const char* sectName, uint64_t& size) const { __block const void* result = nullptr; forEachSection(^(const Header::SectionInfo& sectInfo, bool& stop) { if ( sectInfo.sectionName != sectName ) return; if ( sectInfo.segmentName != segName ) return; size = sectInfo.size; if ( this->isPreload() ) result = (uint8_t*)this + sectInfo.fileOffset; else result = (void*)(sectInfo.address + getSlide()); stop = true; }); return result; } bool MachOLoaded::intersectsRange(uintptr_t start, uintptr_t length) const { __block bool result = false; uintptr_t slide = getSlide(); ((const Header*)this)->forEachSegment(^(const Header::SegmentInfo& info, bool& stop) { if ( (info.vmaddr + info.vmsize + slide >= start) && (info.vmaddr + slide < start + length) ) result = true; }); return result; } //#if BUILDING_DYLD || BUILDING_LIBDYLD void MachOLoaded::fixupAllChainedFixups(Diagnostics& diag, const dyld_chained_starts_in_image* starts, uintptr_t slide, Array<const void*> bindTargets, void (^logFixup)(void* loc, void* newValue)) const { forEachFixupInAllChains(diag, starts, true, ^(ChainedFixupPointerOnDisk* fixupLoc, const dyld_chained_starts_in_segment* segInfo, bool& stop) { void* newValue; switch (segInfo->pointer_format) { #if __LP64__ #if __has_feature(ptrauth_calls) case DYLD_CHAINED_PTR_ARM64E: case DYLD_CHAINED_PTR_ARM64E_KERNEL: case DYLD_CHAINED_PTR_ARM64E_USERLAND: case DYLD_CHAINED_PTR_ARM64E_USERLAND24: if ( fixupLoc->arm64e.authRebase.auth ) { if ( fixupLoc->arm64e.authBind.bind ) { uint32_t bindOrdinal = (segInfo->pointer_format == DYLD_CHAINED_PTR_ARM64E_USERLAND24) ? fixupLoc->arm64e.authBind24.ordinal : fixupLoc->arm64e.authBind.ordinal; if ( bindOrdinal >= bindTargets.count() ) { diag.error("out of range bind ordinal %d (max %llu)", bindOrdinal, bindTargets.count()); stop = true; break; } else { // authenticated bind newValue = (void*)(bindTargets[bindOrdinal]); if (newValue != 0) // Don't sign missing weak imports newValue = (void*)fixupLoc->arm64e.signPointer(fixupLoc, (uintptr_t)newValue); } } else { // authenticated rebase newValue = (void*)fixupLoc->arm64e.signPointer(fixupLoc, (uintptr_t)this + fixupLoc->arm64e.authRebase.target); } } else { if ( fixupLoc->arm64e.bind.bind ) { uint32_t bindOrdinal = (segInfo->pointer_format == DYLD_CHAINED_PTR_ARM64E_USERLAND24) ? fixupLoc->arm64e.bind24.ordinal : fixupLoc->arm64e.bind.ordinal; if ( bindOrdinal >= bindTargets.count() ) { diag.error("out of range bind ordinal %d (max %llu)", bindOrdinal, bindTargets.count()); stop = true; break; } else { // plain bind newValue = (void*)((long)bindTargets[bindOrdinal] + fixupLoc->arm64e.signExtendedAddend()); } } else { // plain rebase (old format target is vmaddr, new format target is offset) if ( segInfo->pointer_format == DYLD_CHAINED_PTR_ARM64E ) newValue = (void*)(fixupLoc->arm64e.unpackTarget()+slide); else newValue = (void*)((uintptr_t)this + fixupLoc->arm64e.unpackTarget()); } } if ( logFixup ) logFixup(fixupLoc, newValue); fixupLoc->raw64 = (uintptr_t)newValue; break; #endif case DYLD_CHAINED_PTR_64: case DYLD_CHAINED_PTR_64_OFFSET: if ( fixupLoc->generic64.bind.bind ) { if ( fixupLoc->generic64.bind.ordinal >= bindTargets.count() ) { diag.error("out of range bind ordinal %d (max %llu)", fixupLoc->generic64.bind.ordinal, bindTargets.count()); stop = true; break; } else { newValue = (void*)((long)bindTargets[fixupLoc->generic64.bind.ordinal] + fixupLoc->generic64.signExtendedAddend()); } } else { // plain rebase (old format target is vmaddr, new format target is offset) if ( segInfo->pointer_format == DYLD_CHAINED_PTR_64 ) newValue = (void*)(fixupLoc->generic64.unpackedTarget()+slide); else newValue = (void*)((uintptr_t)this + fixupLoc->generic64.unpackedTarget()); } if ( logFixup ) logFixup(fixupLoc, newValue); fixupLoc->raw64 = (uintptr_t)newValue; break; #else case DYLD_CHAINED_PTR_32: if ( fixupLoc->generic32.bind.bind ) { if ( fixupLoc->generic32.bind.ordinal >= bindTargets.count() ) { diag.error("out of range bind ordinal %d (max %llu)", fixupLoc->generic32.bind.ordinal, bindTargets.count()); stop = true; break; } else { newValue = (void*)((long)bindTargets[fixupLoc->generic32.bind.ordinal] + fixupLoc->generic32.bind.addend); } } else { if ( fixupLoc->generic32.rebase.target > segInfo->max_valid_pointer ) { // handle non-pointers in chain uint32_t bias = (0x04000000 + segInfo->max_valid_pointer)/2; newValue = (void*)(fixupLoc->generic32.rebase.target - bias); } else { newValue = (void*)(fixupLoc->generic32.rebase.target + slide); } } if ( logFixup ) logFixup(fixupLoc, newValue); fixupLoc->raw32 = (uint32_t)(uintptr_t)newValue; break; #endif // __LP64__ default: diag.error("unsupported pointer chain format: 0x%04X", segInfo->pointer_format); stop = true; break; } }); } //#endif void MachOLoaded::forEachFixupInSegmentChains(Diagnostics& diag, const dyld_chained_starts_in_segment* segInfo, bool notifyNonPointers, void (^handler)(ChainedFixupPointerOnDisk* fixupLocation, const dyld_chained_starts_in_segment* segInfo, bool& stop)) const { auto adaptor = ^(ChainedFixupPointerOnDisk* fixupLocation, bool& stop) { handler(fixupLocation, segInfo, stop); }; bool stopped = false; for (uint32_t pageIndex=0; pageIndex < segInfo->page_count && !stopped; ++pageIndex) { uint16_t offsetInPage = segInfo->page_start[pageIndex]; if ( offsetInPage == DYLD_CHAINED_PTR_START_NONE ) continue; if ( offsetInPage & DYLD_CHAINED_PTR_START_MULTI ) { // 32-bit chains which may need multiple starts per page uint32_t overflowIndex = offsetInPage & ~DYLD_CHAINED_PTR_START_MULTI; bool chainEnd = false; while (!stopped && !chainEnd) { chainEnd = (segInfo->page_start[overflowIndex] & DYLD_CHAINED_PTR_START_LAST); offsetInPage = (segInfo->page_start[overflowIndex] & ~DYLD_CHAINED_PTR_START_LAST); uint8_t* pageContentStart = (uint8_t*)this + segInfo->segment_offset + (pageIndex * segInfo->page_size); ChainedFixupPointerOnDisk* chain = (ChainedFixupPointerOnDisk*)(pageContentStart+offsetInPage); stopped = walkChain(diag, chain, segInfo->pointer_format, notifyNonPointers, segInfo->max_valid_pointer, adaptor); ++overflowIndex; } } else { // one chain per page uint8_t* pageContentStart = (uint8_t*)this + segInfo->segment_offset + (pageIndex * segInfo->page_size); ChainedFixupPointerOnDisk* chain = (ChainedFixupPointerOnDisk*)(pageContentStart+offsetInPage); stopped = walkChain(diag, chain, segInfo->pointer_format, notifyNonPointers, segInfo->max_valid_pointer, adaptor); } } } void MachOLoaded::forEachFixupInAllChains(Diagnostics& diag, const dyld_chained_starts_in_image* starts, bool notifyNonPointers, void (^handler)(ChainedFixupPointerOnDisk* fixupLocation, const dyld_chained_starts_in_segment* segInfo, bool& stop)) const { bool stopped = false; for (uint32_t segIndex=0; segIndex < starts->seg_count && !stopped; ++segIndex) { if ( starts->seg_info_offset[segIndex] == 0 ) continue; const dyld_chained_starts_in_segment* segInfo = (dyld_chained_starts_in_segment*)((uint8_t*)starts + starts->seg_info_offset[segIndex]); forEachFixupInSegmentChains(diag, segInfo, notifyNonPointers, handler); } } void MachOLoaded::forEachFixupInAllChains(Diagnostics& diag, uint16_t pointer_format, uint32_t starts_count, const uint32_t chain_starts[], void (^handler)(ChainedFixupPointerOnDisk* fixupLocation, bool& stop)) const { auto adaptor = ^(ChainedFixupPointerOnDisk* fixupLocation, bool& stop) { handler(fixupLocation, stop); }; for (uint32_t i=0; i < starts_count; ++i) { const uint32_t startVmOffset = chain_starts[i]; __block ChainedFixupPointerOnDisk* chain = nullptr; if ( this->isPreload() ) { // starts are vm-offsets but image is not loaded with zerofill, so need to map vm-offsets to file-offsets __block uint64_t startVmAddr = ~0ULL; ((const Header*)this)->forEachSegment(^(const Header::SegmentInfo& info, bool& stop) { if ( startVmAddr == ~0ULL ) startVmAddr = info.vmaddr + startVmOffset; if ( (info.vmaddr <= startVmAddr) && (startVmAddr < (info.vmaddr + info.vmsize)) ) { uint64_t startFileOffset = info.fileOffset + startVmAddr - info.vmaddr; chain = (ChainedFixupPointerOnDisk*)((uint8_t*)this + startFileOffset); stop = true; } }); } else { chain = (ChainedFixupPointerOnDisk*)((uint8_t*)this + startVmOffset); } if ( walkChain(diag, chain, pointer_format, false, 0, adaptor) ) break; } } uint64_t MachOLoaded::firstSegmentFileOffset() const { __block uint64_t result = 0; ((const Header*)this)->forEachSegment(^(const Header::SegmentInfo& info, bool& stop) { result = info.fileOffset; stop = true; }); return result; } } // namespace dyld3 |