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dyld-851.27.tar.gz
[apple/dyld.git] / src / ImageLoaderMachOCompressed.cpp
1 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
2 *
3 * Copyright (c) 2008 Apple Inc. All rights reserved.
4 *
5 * @APPLE_LICENSE_HEADER_START@
6 *
7 * This file contains Original Code and/or Modifications of Original Code
8 * as defined in and that are subject to the Apple Public Source License
9 * Version 2.0 (the 'License'). You may not use this file except in
10 * compliance with the License. Please obtain a copy of the License at
11 * http://www.opensource.apple.com/apsl/ and read it before using this
12 * file.
13 *
14 * The Original Code and all software distributed under the License are
15 * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
16 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
17 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
19 * Please see the License for the specific language governing rights and
20 * limitations under the License.
21 *
22 * @APPLE_LICENSE_HEADER_END@
23 */
24
25
26 #if __arm__ || __arm64__
27 #include <System/sys/mman.h>
28 #else
29 #include <sys/mman.h>
30 #endif
31 #include <string.h>
32 #include <fcntl.h>
33 #include <errno.h>
34 #include <sys/types.h>
35 #include <sys/fcntl.h>
36 #include <sys/stat.h>
37 #include <sys/param.h>
38 #include <mach/mach.h>
39 #include <mach/thread_status.h>
40 #include <mach-o/loader.h>
41 #include <mach-o/dyld_images.h>
42
43 #include "dyld2.h"
44 #include "ImageLoaderMachOCompressed.h"
45 #include "Closure.h"
46 #include "Array.h"
47
48 #ifndef BIND_SUBOPCODE_THREADED_SET_JOP
49 #define BIND_SUBOPCODE_THREADED_SET_JOP 0x0F
50 #endif
51
52 // relocation_info.r_length field has value 3 for 64-bit executables and value 2 for 32-bit executables
53 #if __LP64__
54 #define RELOC_SIZE 3
55 #define LC_SEGMENT_COMMAND LC_SEGMENT_64
56 #define LC_ROUTINES_COMMAND LC_ROUTINES_64
57 struct macho_segment_command : public segment_command_64 {};
58 struct macho_section : public section_64 {};
59 struct macho_routines_command : public routines_command_64 {};
60 #else
61 #define RELOC_SIZE 2
62 #define LC_SEGMENT_COMMAND LC_SEGMENT
63 #define LC_ROUTINES_COMMAND LC_ROUTINES
64 struct macho_segment_command : public segment_command {};
65 struct macho_section : public section {};
66 struct macho_routines_command : public routines_command {};
67 #endif
68
69
70
71 // create image for main executable
72 ImageLoaderMachOCompressed* ImageLoaderMachOCompressed::instantiateMainExecutable(const macho_header* mh, uintptr_t slide, const char* path,
73 unsigned int segCount, unsigned int libCount, const LinkContext& context)
74 {
75 ImageLoaderMachOCompressed* image = ImageLoaderMachOCompressed::instantiateStart(mh, path, segCount, libCount);
76
77 // set slide for PIE programs
78 image->setSlide(slide);
79
80 // for PIE record end of program, to know where to start loading dylibs
81 if ( slide != 0 )
82 fgNextPIEDylibAddress = (uintptr_t)image->getEnd();
83
84 image->disableCoverageCheck();
85 image->instantiateFinish(context);
86 image->setMapped(context);
87
88 if ( context.verboseMapping ) {
89 dyld::log("dyld: Main executable mapped %s\n", path);
90 for(unsigned int i=0, e=image->segmentCount(); i < e; ++i) {
91 const char* name = image->segName(i);
92 if ( (strcmp(name, "__PAGEZERO") == 0) || (strcmp(name, "__UNIXSTACK") == 0) )
93 dyld::log("%18s at 0x%08lX->0x%08lX\n", name, image->segPreferredLoadAddress(i), image->segPreferredLoadAddress(i)+image->segSize(i));
94 else
95 dyld::log("%18s at 0x%08lX->0x%08lX\n", name, image->segActualLoadAddress(i), image->segActualEndAddress(i));
96 }
97 }
98
99 return image;
100 }
101
102 // create image by mapping in a mach-o file
103 ImageLoaderMachOCompressed* ImageLoaderMachOCompressed::instantiateFromFile(const char* path, int fd, const uint8_t* fileData, size_t lenFileData,
104 uint64_t offsetInFat, uint64_t lenInFat, const struct stat& info,
105 unsigned int segCount, unsigned int libCount,
106 const struct linkedit_data_command* codeSigCmd,
107 const struct encryption_info_command* encryptCmd,
108 const LinkContext& context)
109 {
110 ImageLoaderMachOCompressed* image = ImageLoaderMachOCompressed::instantiateStart((macho_header*)fileData, path, segCount, libCount);
111
112 try {
113 // record info about file
114 image->setFileInfo(info.st_dev, info.st_ino, info.st_mtime);
115
116 // if this image is code signed, let kernel validate signature before mapping any pages from image
117 image->loadCodeSignature(codeSigCmd, fd, offsetInFat, context);
118
119 // Validate that first data we read with pread actually matches with code signature
120 image->validateFirstPages(codeSigCmd, fd, fileData, lenFileData, offsetInFat, context);
121
122 // mmap segments
123 image->mapSegments(fd, offsetInFat, lenInFat, info.st_size, context);
124
125 // if framework is FairPlay encrypted, register with kernel
126 image->registerEncryption(encryptCmd, context);
127
128 // probe to see if code signed correctly
129 image->crashIfInvalidCodeSignature();
130
131 // finish construction
132 image->instantiateFinish(context);
133
134 // if path happens to be same as in LC_DYLIB_ID load command use that, otherwise malloc a copy of the path
135 const char* installName = image->getInstallPath();
136 if ( (installName != NULL) && (strcmp(installName, path) == 0) && (path[0] == '/') )
137 image->setPathUnowned(installName);
138 #if TARGET_OS_OSX
139 // <rdar://problem/6563887> app crashes when libSystem cannot be found
140 else if ( (installName != NULL) && (strcmp(path, "/usr/lib/libgcc_s.1.dylib") == 0) && (strcmp(installName, "/usr/lib/libSystem.B.dylib") == 0) )
141 image->setPathUnowned("/usr/lib/libSystem.B.dylib");
142 #endif
143 else if ( (path[0] != '/') || (strstr(path, "../") != NULL) ) {
144 // rdar://problem/10733082 Fix up @rpath based paths during introspection
145 // rdar://problem/5135363 turn relative paths into absolute paths so gdb, Symbolication can later find them
146 char realPath[MAXPATHLEN];
147 if ( fcntl(fd, F_GETPATH, realPath) == 0 )
148 image->setPaths(path, realPath);
149 else
150 image->setPath(path);
151 }
152 else {
153 // <rdar://problem/46682306> always try to realpath dylibs since they may have been dlopen()ed using a symlink path
154 if ( installName != NULL ) {
155 char realPath[MAXPATHLEN];
156 if ( (fcntl(fd, F_GETPATH, realPath) == 0) && (strcmp(path, realPath) != 0) )
157 image->setPaths(path, realPath);
158 else
159 image->setPath(path);
160 }
161 else {
162 image->setPath(path);
163 }
164 }
165
166 // make sure path is stable before recording in dyld_all_image_infos
167 image->setMapped(context);
168
169 }
170 catch (...) {
171 // ImageLoader::setMapped() can throw an exception to block loading of image
172 // <rdar://problem/6169686> Leaked fSegmentsArray and image segments during failed dlopen_preflight
173 delete image;
174 throw;
175 }
176
177 return image;
178 }
179
180 // create image by using cached mach-o file
181 ImageLoaderMachOCompressed* ImageLoaderMachOCompressed::instantiateFromCache(const macho_header* mh, const char* path, long slide,
182 const struct stat& info, unsigned int segCount,
183 unsigned int libCount, const LinkContext& context)
184 {
185 ImageLoaderMachOCompressed* image = ImageLoaderMachOCompressed::instantiateStart(mh, path, segCount, libCount);
186 try {
187 // record info about file
188 image->setFileInfo(info.st_dev, info.st_ino, info.st_mtime);
189
190 // remember this is from shared cache and cannot be unloaded
191 image->fInSharedCache = true;
192 image->setNeverUnload();
193 image->setSlide(slide);
194 image->disableCoverageCheck();
195
196 // segments already mapped in cache
197 if ( context.verboseMapping ) {
198 dyld::log("dyld: Using shared cached for %s\n", path);
199 for(unsigned int i=0; i < image->fSegmentsCount; ++i) {
200 dyld::log("%18s at 0x%08lX->0x%08lX\n", image->segName(i), image->segActualLoadAddress(i), image->segActualEndAddress(i));
201 }
202 }
203
204 image->instantiateFinish(context);
205
206 #if TARGET_OS_SIMULATOR
207 char realPath[MAXPATHLEN] = { 0 };
208 if ( dyld::gLinkContext.rootPaths == NULL )
209 throw "root path is not set";
210 strlcpy(realPath, dyld::gLinkContext.rootPaths[0], MAXPATHLEN);
211 strlcat(realPath, path, MAXPATHLEN);
212 image->setPaths(path, realPath);
213 #endif
214 image->setMapped(context);
215 }
216 catch (...) {
217 // ImageLoader::setMapped() can throw an exception to block loading of image
218 // <rdar://problem/6169686> Leaked fSegmentsArray and image segments during failed dlopen_preflight
219 delete image;
220 throw;
221 }
222
223 return image;
224 }
225
226 // create image by copying an in-memory mach-o file
227 ImageLoaderMachOCompressed* ImageLoaderMachOCompressed::instantiateFromMemory(const char* moduleName, const macho_header* mh, uint64_t len,
228 unsigned int segCount, unsigned int libCount, const LinkContext& context)
229 {
230 ImageLoaderMachOCompressed* image = ImageLoaderMachOCompressed::instantiateStart(mh, moduleName, segCount, libCount);
231 try {
232 // map segments
233 if ( mh->filetype == MH_EXECUTE )
234 throw "can't load another MH_EXECUTE";
235
236 // vmcopy segments
237 image->mapSegments((const void*)mh, len, context);
238
239 // for compatibility, never unload dylibs loaded from memory
240 image->setNeverUnload();
241
242 image->disableCoverageCheck();
243
244 // bundle loads need path copied
245 if ( moduleName != NULL )
246 image->setPath(moduleName);
247
248 image->instantiateFinish(context);
249 image->setMapped(context);
250 }
251 catch (...) {
252 // ImageLoader::setMapped() can throw an exception to block loading of image
253 // <rdar://problem/6169686> Leaked fSegmentsArray and image segments during failed dlopen_preflight
254 delete image;
255 throw;
256 }
257
258 return image;
259 }
260
261
262 ImageLoaderMachOCompressed::ImageLoaderMachOCompressed(const macho_header* mh, const char* path, unsigned int segCount,
263 uint32_t segOffsets[], unsigned int libCount)
264 : ImageLoaderMachO(mh, path, segCount, segOffsets, libCount), fDyldInfo(NULL), fChainedFixups(NULL), fExportsTrie(NULL)
265 {
266 }
267
268 ImageLoaderMachOCompressed::~ImageLoaderMachOCompressed()
269 {
270 // don't do clean up in ~ImageLoaderMachO() because virtual call to segmentCommandOffsets() won't work
271 destroy();
272 }
273
274
275
276 // construct ImageLoaderMachOCompressed using "placement new" with SegmentMachO objects array at end
277 ImageLoaderMachOCompressed* ImageLoaderMachOCompressed::instantiateStart(const macho_header* mh, const char* path,
278 unsigned int segCount, unsigned int libCount)
279 {
280 size_t size = sizeof(ImageLoaderMachOCompressed) + segCount * sizeof(uint32_t) + libCount * sizeof(ImageLoader*);
281 ImageLoaderMachOCompressed* allocatedSpace = static_cast<ImageLoaderMachOCompressed*>(malloc(size));
282 if ( allocatedSpace == NULL )
283 throw "malloc failed";
284 uint32_t* segOffsets = ((uint32_t*)(((uint8_t*)allocatedSpace) + sizeof(ImageLoaderMachOCompressed)));
285 bzero(&segOffsets[segCount], libCount*sizeof(void*)); // zero out lib array
286 return new (allocatedSpace) ImageLoaderMachOCompressed(mh, path, segCount, segOffsets, libCount);
287 }
288
289
290 // common code to finish initializing object
291 void ImageLoaderMachOCompressed::instantiateFinish(const LinkContext& context)
292 {
293 // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
294 this->parseLoadCmds(context);
295 }
296
297 uint32_t* ImageLoaderMachOCompressed::segmentCommandOffsets() const
298 {
299 return ((uint32_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOCompressed)));
300 }
301
302
303 ImageLoader* ImageLoaderMachOCompressed::libImage(unsigned int libIndex) const
304 {
305 const uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOCompressed) + fSegmentsCount*sizeof(uint32_t)));
306 // mask off low bits
307 return (ImageLoader*)(images[libIndex] & (-4));
308 }
309
310 bool ImageLoaderMachOCompressed::libReExported(unsigned int libIndex) const
311 {
312 const uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOCompressed) + fSegmentsCount*sizeof(uint32_t)));
313 // re-export flag is low bit
314 return ((images[libIndex] & 1) != 0);
315 }
316
317 bool ImageLoaderMachOCompressed::libIsUpward(unsigned int libIndex) const
318 {
319 const uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOCompressed) + fSegmentsCount*sizeof(uint32_t)));
320 // upward flag is second bit
321 return ((images[libIndex] & 2) != 0);
322 }
323
324
325 void ImageLoaderMachOCompressed::setLibImage(unsigned int libIndex, ImageLoader* image, bool reExported, bool upward)
326 {
327 uintptr_t* images = ((uintptr_t*)(((uint8_t*)this) + sizeof(ImageLoaderMachOCompressed) + fSegmentsCount*sizeof(uint32_t)));
328 uintptr_t value = (uintptr_t)image;
329 if ( reExported )
330 value |= 1;
331 if ( upward )
332 value |= 2;
333 images[libIndex] = value;
334 }
335
336
337 void ImageLoaderMachOCompressed::rebaseAt(const LinkContext& context, uintptr_t addr, uintptr_t slide, uint8_t type)
338 {
339 if ( context.verboseRebase ) {
340 dyld::log("dyld: rebase: %s:*0x%08lX += 0x%08lX\n", this->getShortName(), (uintptr_t)addr, slide);
341 }
342 //dyld::log("0x%08lX type=%d\n", addr, type);
343 uintptr_t* locationToFix = (uintptr_t*)addr;
344 switch (type) {
345 case REBASE_TYPE_POINTER:
346 *locationToFix += slide;
347 break;
348 case REBASE_TYPE_TEXT_ABSOLUTE32:
349 *locationToFix += slide;
350 break;
351 default:
352 dyld::throwf("bad rebase type %d", type);
353 }
354 }
355
356 void ImageLoaderMachOCompressed::throwBadRebaseAddress(uintptr_t address, uintptr_t segmentEndAddress, int segmentIndex,
357 const uint8_t* startOpcodes, const uint8_t* endOpcodes, const uint8_t* pos)
358 {
359 dyld::throwf("malformed rebase opcodes (%ld/%ld): address 0x%08lX is outside of segment %s (0x%08lX -> 0x%08lX)",
360 (intptr_t)(pos-startOpcodes), (intptr_t)(endOpcodes-startOpcodes), address, segName(segmentIndex),
361 segActualLoadAddress(segmentIndex), segmentEndAddress);
362 }
363
364 void ImageLoaderMachOCompressed::rebase(const LinkContext& context, uintptr_t slide)
365 {
366 // binary uses chained fixups where are applied during binding
367 if ( fDyldInfo == NULL )
368 return;
369
370 CRSetCrashLogMessage2(this->getPath());
371 const uint8_t* const start = fLinkEditBase + fDyldInfo->rebase_off;
372 const uint8_t* const end = &start[fDyldInfo->rebase_size];
373 const uint8_t* p = start;
374
375 if ( start == end )
376 return;
377
378 uint32_t ignore;
379 bool bindingBecauseOfRoot = this->overridesCachedDylib(ignore);
380 vmAccountingSetSuspended(context, bindingBecauseOfRoot);
381
382 try {
383 uint8_t type = 0;
384 int segmentIndex = 0;
385 uintptr_t address = segActualLoadAddress(0);
386 uintptr_t segmentStartAddress = segActualLoadAddress(0);
387 uintptr_t segmentEndAddress = segActualEndAddress(0);
388 uintptr_t count;
389 uintptr_t skip;
390 bool done = false;
391 while ( !done && (p < end) ) {
392 uint8_t immediate = *p & REBASE_IMMEDIATE_MASK;
393 uint8_t opcode = *p & REBASE_OPCODE_MASK;
394 ++p;
395 switch (opcode) {
396 case REBASE_OPCODE_DONE:
397 done = true;
398 break;
399 case REBASE_OPCODE_SET_TYPE_IMM:
400 type = immediate;
401 break;
402 case REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
403 segmentIndex = immediate;
404 if ( segmentIndex >= fSegmentsCount )
405 dyld::throwf("REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is too large (0..%d)",
406 segmentIndex, fSegmentsCount-1);
407 #if TEXT_RELOC_SUPPORT
408 if ( !segWriteable(segmentIndex) && !segHasRebaseFixUps(segmentIndex) && !segHasBindFixUps(segmentIndex) )
409 #else
410 if ( !segWriteable(segmentIndex) )
411 #endif
412 dyld::throwf("REBASE_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is not a writable segment (%s)",
413 segmentIndex, segName(segmentIndex));
414 segmentStartAddress = segActualLoadAddress(segmentIndex);
415 segmentEndAddress = segActualEndAddress(segmentIndex);
416 address = segmentStartAddress + read_uleb128(p, end);
417 break;
418 case REBASE_OPCODE_ADD_ADDR_ULEB:
419 address += read_uleb128(p, end);
420 break;
421 case REBASE_OPCODE_ADD_ADDR_IMM_SCALED:
422 address += immediate*sizeof(uintptr_t);
423 break;
424 case REBASE_OPCODE_DO_REBASE_IMM_TIMES:
425 for (int i=0; i < immediate; ++i) {
426 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
427 throwBadRebaseAddress(address, segmentEndAddress, segmentIndex, start, end, p);
428 rebaseAt(context, address, slide, type);
429 address += sizeof(uintptr_t);
430 }
431 fgTotalRebaseFixups += immediate;
432 break;
433 case REBASE_OPCODE_DO_REBASE_ULEB_TIMES:
434 count = read_uleb128(p, end);
435 for (uint32_t i=0; i < count; ++i) {
436 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
437 throwBadRebaseAddress(address, segmentEndAddress, segmentIndex, start, end, p);
438 rebaseAt(context, address, slide, type);
439 address += sizeof(uintptr_t);
440 }
441 fgTotalRebaseFixups += count;
442 break;
443 case REBASE_OPCODE_DO_REBASE_ADD_ADDR_ULEB:
444 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
445 throwBadRebaseAddress(address, segmentEndAddress, segmentIndex, start, end, p);
446 rebaseAt(context, address, slide, type);
447 address += read_uleb128(p, end) + sizeof(uintptr_t);
448 ++fgTotalRebaseFixups;
449 break;
450 case REBASE_OPCODE_DO_REBASE_ULEB_TIMES_SKIPPING_ULEB:
451 count = read_uleb128(p, end);
452 skip = read_uleb128(p, end);
453 for (uint32_t i=0; i < count; ++i) {
454 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
455 throwBadRebaseAddress(address, segmentEndAddress, segmentIndex, start, end, p);
456 rebaseAt(context, address, slide, type);
457 address += skip + sizeof(uintptr_t);
458 }
459 fgTotalRebaseFixups += count;
460 break;
461 default:
462 dyld::throwf("bad rebase opcode %d", *(p-1));
463 }
464 }
465 }
466 catch (const char* msg) {
467 const char* newMsg = dyld::mkstringf("%s in %s", msg, this->getPath());
468 free((void*)msg);
469 throw newMsg;
470 }
471 CRSetCrashLogMessage2(NULL);
472 }
473
474 const ImageLoader::Symbol* ImageLoaderMachOCompressed::findShallowExportedSymbol(const char* symbol, const ImageLoader** foundIn) const
475 {
476 //dyld::log("Compressed::findExportedSymbol(%s) in %s\n", symbol, this->getShortName());
477 uint32_t trieFileOffset = fDyldInfo ? fDyldInfo->export_off : fExportsTrie->dataoff;
478 uint32_t trieFileSize = fDyldInfo ? fDyldInfo->export_size : fExportsTrie->datasize;
479 if ( trieFileSize == 0 )
480 return NULL;
481 #if LOG_BINDINGS
482 dyld::logBindings("%s: %s\n", this->getShortName(), symbol);
483 #endif
484 ++ImageLoaderMachO::fgSymbolTrieSearchs;
485 const uint8_t* start = &fLinkEditBase[trieFileOffset];
486 const uint8_t* end = &start[trieFileSize];
487 const uint8_t* foundNodeStart = this->trieWalk(start, end, symbol);
488 if ( foundNodeStart != NULL ) {
489 const uint8_t* p = foundNodeStart;
490 const uintptr_t flags = read_uleb128(p, end);
491 // found match, return pointer to terminal part of node
492 if ( flags & EXPORT_SYMBOL_FLAGS_REEXPORT ) {
493 // re-export from another dylib, lookup there
494 const uintptr_t ordinal = read_uleb128(p, end);
495 const char* importedName = (char*)p;
496 if ( importedName[0] == '\0' )
497 importedName = symbol;
498 if ( (ordinal > 0) && (ordinal <= libraryCount()) ) {
499 const ImageLoader* reexportedFrom = libImage((unsigned int)ordinal-1);
500 // Missing weak-dylib
501 if ( reexportedFrom == NULL )
502 return NULL;
503 //dyld::log("Compressed::findExportedSymbol(), %s -> %s/%s\n", symbol, reexportedFrom->getShortName(), importedName);
504 const char* reExportLibPath = libPath((unsigned int)ordinal-1);
505 return reexportedFrom->findExportedSymbol(importedName, true, reExportLibPath, foundIn);
506 }
507 else {
508 //dyld::throwf("bad mach-o binary, library ordinal (%u) invalid (max %u) for re-exported symbol %s in %s",
509 // ordinal, libraryCount(), symbol, this->getPath());
510 }
511 }
512 else {
513 //dyld::log("findExportedSymbol(%s) in %s found match, returning %p\n", symbol, this->getShortName(), p);
514 if ( foundIn != NULL )
515 *foundIn = (ImageLoader*)this;
516 // return pointer to terminal part of node
517 return (Symbol*)foundNodeStart;
518 }
519 }
520 return NULL;
521 }
522
523
524 bool ImageLoaderMachOCompressed::containsSymbol(const void* addr) const
525 {
526 uint32_t trieFileOffset = fDyldInfo ? fDyldInfo->export_off : fExportsTrie->dataoff;
527 uint32_t trieFileSize = fDyldInfo ? fDyldInfo->export_size : fExportsTrie->datasize;
528 const uint8_t* start = &fLinkEditBase[trieFileOffset];
529 const uint8_t* end = &start[trieFileSize];
530 return ( (start <= addr) && (addr < end) );
531 }
532
533
534 uintptr_t ImageLoaderMachOCompressed::exportedSymbolAddress(const LinkContext& context, const Symbol* symbol, const ImageLoader* requestor, bool runResolver) const
535 {
536 uint32_t trieFileOffset = fDyldInfo ? fDyldInfo->export_off : fExportsTrie->dataoff;
537 uint32_t trieFileSize = fDyldInfo ? fDyldInfo->export_size : fExportsTrie->datasize;
538 const uint8_t* exportNode = (uint8_t*)symbol;
539 const uint8_t* exportTrieStart = fLinkEditBase + trieFileOffset;
540 const uint8_t* exportTrieEnd = exportTrieStart + trieFileSize;
541 if ( (exportNode < exportTrieStart) || (exportNode > exportTrieEnd) )
542 throw "symbol is not in trie";
543 //dyld::log("exportedSymbolAddress(): node=%p, nodeOffset=0x%04X in %s\n", symbol, (int)((uint8_t*)symbol - exportTrieStart), this->getShortName());
544 uintptr_t flags = read_uleb128(exportNode, exportTrieEnd);
545 switch ( flags & EXPORT_SYMBOL_FLAGS_KIND_MASK ) {
546 case EXPORT_SYMBOL_FLAGS_KIND_REGULAR:
547 if ( runResolver && (flags & EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER) ) {
548 // this node has a stub and resolver, run the resolver to get target address
549 uintptr_t stub = read_uleb128(exportNode, exportTrieEnd) + (uintptr_t)fMachOData; // skip over stub
550 // <rdar://problem/10657737> interposing dylibs have the stub address as their replacee
551 uintptr_t interposedStub = interposedAddress(context, stub, requestor);
552 if ( interposedStub != stub )
553 return interposedStub;
554 // stub was not interposed, so run resolver
555 typedef uintptr_t (*ResolverProc)(void);
556 ResolverProc resolver = (ResolverProc)(read_uleb128(exportNode, exportTrieEnd) + (uintptr_t)fMachOData);
557 #if __has_feature(ptrauth_calls)
558 resolver = (ResolverProc)__builtin_ptrauth_sign_unauthenticated(resolver, ptrauth_key_asia, 0);
559 #endif
560 uintptr_t result = (*resolver)();
561 if ( context.verboseBind )
562 dyld::log("dyld: resolver at %p returned 0x%08lX\n", resolver, result);
563 #if __has_feature(ptrauth_calls)
564 result = (uintptr_t)__builtin_ptrauth_strip((void*)result, ptrauth_key_asia);
565 #endif
566 return result;
567 }
568 return read_uleb128(exportNode, exportTrieEnd) + (uintptr_t)fMachOData;
569 case EXPORT_SYMBOL_FLAGS_KIND_THREAD_LOCAL:
570 if ( flags & EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER )
571 dyld::throwf("unsupported exported symbol kind. flags=%lu at node=%p", flags, symbol);
572 return read_uleb128(exportNode, exportTrieEnd) + (uintptr_t)fMachOData;
573 case EXPORT_SYMBOL_FLAGS_KIND_ABSOLUTE:
574 if ( flags & EXPORT_SYMBOL_FLAGS_STUB_AND_RESOLVER )
575 dyld::throwf("unsupported exported symbol kind. flags=%lu at node=%p", flags, symbol);
576 return read_uleb128(exportNode, exportTrieEnd);
577 default:
578 dyld::throwf("unsupported exported symbol kind. flags=%lu at node=%p", flags, symbol);
579 }
580 }
581
582 bool ImageLoaderMachOCompressed::exportedSymbolIsWeakDefintion(const Symbol* symbol) const
583 {
584 uint32_t trieFileOffset = fDyldInfo ? fDyldInfo->export_off : fExportsTrie->dataoff;
585 uint32_t trieFileSize = fDyldInfo ? fDyldInfo->export_size : fExportsTrie->datasize;
586 const uint8_t* exportNode = (uint8_t*)symbol;
587 const uint8_t* exportTrieStart = fLinkEditBase + trieFileOffset;
588 const uint8_t* exportTrieEnd = exportTrieStart + trieFileSize;
589 if ( (exportNode < exportTrieStart) || (exportNode > exportTrieEnd) )
590 throw "symbol is not in trie";
591 uintptr_t flags = read_uleb128(exportNode, exportTrieEnd);
592 return ( flags & EXPORT_SYMBOL_FLAGS_WEAK_DEFINITION );
593 }
594
595
596 const char* ImageLoaderMachOCompressed::exportedSymbolName(const Symbol* symbol) const
597 {
598 throw "NSNameOfSymbol() not supported with compressed LINKEDIT";
599 }
600
601 unsigned int ImageLoaderMachOCompressed::exportedSymbolCount() const
602 {
603 throw "NSSymbolDefinitionCountInObjectFileImage() not supported with compressed LINKEDIT";
604 }
605
606 const ImageLoader::Symbol* ImageLoaderMachOCompressed::exportedSymbolIndexed(unsigned int index) const
607 {
608 throw "NSSymbolDefinitionNameInObjectFileImage() not supported with compressed LINKEDIT";
609 }
610
611 unsigned int ImageLoaderMachOCompressed::importedSymbolCount() const
612 {
613 throw "NSSymbolReferenceCountInObjectFileImage() not supported with compressed LINKEDIT";
614 }
615
616 const ImageLoader::Symbol* ImageLoaderMachOCompressed::importedSymbolIndexed(unsigned int index) const
617 {
618 throw "NSSymbolReferenceCountInObjectFileImage() not supported with compressed LINKEDIT";
619 }
620
621 const char* ImageLoaderMachOCompressed::importedSymbolName(const Symbol* symbol) const
622 {
623 throw "NSSymbolReferenceNameInObjectFileImage() not supported with compressed LINKEDIT";
624 }
625
626
627
628 uintptr_t ImageLoaderMachOCompressed::resolveFlat(const LinkContext& context, const char* symbolName, bool weak_import,
629 bool runResolver, const ImageLoader** foundIn)
630 {
631 const Symbol* sym;
632 if ( context.flatExportFinder(symbolName, &sym, foundIn) ) {
633 if ( *foundIn != this )
634 context.addDynamicReference(this, const_cast<ImageLoader*>(*foundIn));
635 return (*foundIn)->getExportedSymbolAddress(sym, context, this, runResolver);
636 }
637 // if a bundle is loaded privately the above will not find its exports
638 if ( this->isBundle() && this->hasHiddenExports() ) {
639 // look in self for needed symbol
640 sym = this->findShallowExportedSymbol(symbolName, foundIn);
641 if ( sym != NULL )
642 return (*foundIn)->getExportedSymbolAddress(sym, context, this, runResolver);
643 }
644 if ( weak_import ) {
645 // definition can't be found anywhere, ok because it is weak, just return 0
646 return 0;
647 }
648 throwSymbolNotFound(context, symbolName, this->getPath(), "", "flat namespace");
649 }
650
651
652 static void patchCacheUsesOf(const ImageLoader::LinkContext& context, const dyld3::closure::Image* overriddenImage,
653 uint32_t cacheOffsetOfImpl, const char* symbolName, uintptr_t newImpl,
654 DyldSharedCache::DataConstLazyScopedWriter& patcher)
655 {
656 patcher.makeWriteable();
657
658 uintptr_t cacheStart = (uintptr_t)context.dyldCache;
659 uint32_t imageIndex = overriddenImage->imageNum() - (uint32_t)context.dyldCache->cachedDylibsImageArray()->startImageNum();
660 context.dyldCache->forEachPatchableUseOfExport(imageIndex, cacheOffsetOfImpl, ^(dyld_cache_patchable_location patchLocation) {
661 uintptr_t* loc = (uintptr_t*)(cacheStart+patchLocation.cacheOffset);
662 #if __has_feature(ptrauth_calls)
663 if ( patchLocation.authenticated ) {
664 dyld3::MachOLoaded::ChainedFixupPointerOnDisk fixupInfo;
665 fixupInfo.arm64e.authRebase.auth = true;
666 fixupInfo.arm64e.authRebase.addrDiv = patchLocation.usesAddressDiversity;
667 fixupInfo.arm64e.authRebase.diversity = patchLocation.discriminator;
668 fixupInfo.arm64e.authRebase.key = patchLocation.key;
669 uintptr_t newValue = fixupInfo.arm64e.signPointer(loc, newImpl + DyldSharedCache::getAddend(patchLocation));
670 if ( *loc != newValue ) {
671 *loc = newValue;
672 if ( context.verboseBind )
673 dyld::log("dyld: cache fixup: *%p = %p (JOP: diversity 0x%04X, addr-div=%d, key=%s) to %s\n",
674 loc, (void*)newValue, patchLocation.discriminator, patchLocation.usesAddressDiversity, DyldSharedCache::keyName(patchLocation), symbolName);
675 }
676 return;
677 }
678 #endif
679 uintptr_t newValue = newImpl + (uintptr_t)DyldSharedCache::getAddend(patchLocation);
680 if ( *loc != newValue ) {
681 *loc = newValue;
682 if ( context.verboseBind )
683 dyld::log("dyld: cache fixup: *%p = %p to %s\n", loc, (void*)newValue, symbolName);
684 }
685 });
686 }
687
688
689
690 uintptr_t ImageLoaderMachOCompressed::resolveWeak(const LinkContext& context, const char* symbolName, bool weak_import,
691 bool runResolver, const ImageLoader** foundIn,
692 DyldSharedCache::DataConstLazyScopedWriter& patcher)
693 {
694 const Symbol* sym;
695 CoalesceNotifier notifier = nullptr;
696 __block uintptr_t foundOutsideCache = 0;
697 __block const char* foundOutsideCachePath = nullptr;
698 __block uintptr_t lastFoundInCache = 0;
699
700 if ( this->usesChainedFixups() ) {
701 notifier = ^(const Symbol* implSym, const ImageLoader* implIn, const mach_header* implMh) {
702 // This block is only called in dyld2 mode when a non-cached image is search for which weak-def implementation to use
703 // As a side effect of that search we notice any implementations outside and inside the cache,
704 // and use that to trigger patching the cache to use the implementation outside the cache.
705 uintptr_t implAddr = implIn->getExportedSymbolAddress(implSym, context, nullptr, false, symbolName);
706 if ( ((dyld3::MachOLoaded*)implMh)->inDyldCache() ) {
707 if ( foundOutsideCache != 0 ) {
708 // have an implementation in cache and and earlier one not in the cache, patch cache to use earlier one
709 lastFoundInCache = implAddr;
710 uint32_t imageIndex;
711 if ( context.dyldCache->findMachHeaderImageIndex(implMh, imageIndex) ) {
712 const dyld3::closure::Image* overriddenImage = context.dyldCache->cachedDylibsImageArray()->imageForNum(imageIndex+1);
713 uint32_t cacheOffsetOfImpl = (uint32_t)((uintptr_t)implAddr - (uintptr_t)context.dyldCache);
714 if ( context.verboseWeakBind )
715 dyld::log("dyld: weak bind, patching dyld cache uses of %s to use 0x%lX in %s\n", symbolName, foundOutsideCache, foundOutsideCachePath);
716 patchCacheUsesOf(context, overriddenImage, cacheOffsetOfImpl, symbolName, foundOutsideCache, patcher);
717 }
718 }
719 }
720 else {
721 // record first non-cache implementation
722 if ( foundOutsideCache == 0 ) {
723 foundOutsideCache = implAddr;
724 foundOutsideCachePath = implIn->getPath();
725 }
726 }
727 };
728 }
729
730 if ( context.coalescedExportFinder(symbolName, &sym, foundIn, notifier) ) {
731 if ( *foundIn != this )
732 context.addDynamicReference(this, const_cast<ImageLoader*>(*foundIn));
733 return (*foundIn)->getExportedSymbolAddress(sym, context, this, runResolver);
734 }
735 // if a bundle is loaded privately the above will not find its exports
736 if ( this->isBundle() && this->hasHiddenExports() ) {
737 // look in self for needed symbol
738 sym = this->findShallowExportedSymbol(symbolName, foundIn);
739 if ( sym != NULL )
740 return (*foundIn)->getExportedSymbolAddress(sym, context, this, runResolver);
741 }
742 if ( weak_import ) {
743 // definition can't be found anywhere, ok because it is weak, just return 0
744 return 0;
745 }
746 throwSymbolNotFound(context, symbolName, this->getPath(), "", "weak");
747 }
748
749
750 uintptr_t ImageLoaderMachOCompressed::resolveTwolevel(const LinkContext& context, const char* symbolName, const ImageLoader* definedInImage,
751 const ImageLoader* requestorImage, unsigned requestorOrdinalOfDef, bool weak_import, bool runResolver,
752 const ImageLoader** foundIn)
753 {
754 // two level lookup
755 uintptr_t address;
756 if ( definedInImage->findExportedSymbolAddress(context, symbolName, requestorImage, requestorOrdinalOfDef, runResolver, foundIn, &address) )
757 return address;
758
759 if ( weak_import ) {
760 // definition can't be found anywhere, ok because it is weak, just return 0
761 return 0;
762 }
763
764 // nowhere to be found, check if maybe this image is too new for this OS
765 char versMismatch[256];
766 versMismatch[0] = '\0';
767 uint32_t imageMinOS = this->minOSVersion();
768 // dyld is always built for the current OS, so we can get the current OS version
769 // from the load command in dyld itself.
770 extern const mach_header __dso_handle;
771 uint32_t dyldMinOS = ImageLoaderMachO::minOSVersion(&__dso_handle);
772 if ( imageMinOS > dyldMinOS ) {
773 #if TARGET_OS_OSX
774 const char* msg = dyld::mkstringf(" (which was built for Mac OS X %d.%d)", imageMinOS >> 16, (imageMinOS >> 8) & 0xFF);
775 #else
776 const char* msg = dyld::mkstringf(" (which was built for iOS %d.%d)", imageMinOS >> 16, (imageMinOS >> 8) & 0xFF);
777 #endif
778 strcpy(versMismatch, msg);
779 ::free((void*)msg);
780 }
781 throwSymbolNotFound(context, symbolName, this->getPath(), versMismatch, definedInImage->getPath());
782 }
783
784
785 uintptr_t ImageLoaderMachOCompressed::resolve(const LinkContext& context, const char* symbolName,
786 uint8_t symboFlags, long libraryOrdinal, const ImageLoader** targetImage,
787 DyldSharedCache::DataConstLazyScopedWriter& patcher,
788 LastLookup* last, bool runResolver)
789 {
790 *targetImage = NULL;
791
792 // only clients that benefit from caching last lookup pass in a LastLookup struct
793 if ( last != NULL ) {
794 if ( (last->ordinal == libraryOrdinal)
795 && (last->flags == symboFlags)
796 && (last->name == symbolName) ) {
797 *targetImage = last->foundIn;
798 return last->result;
799 }
800 }
801
802 bool weak_import = (symboFlags & BIND_SYMBOL_FLAGS_WEAK_IMPORT);
803 uintptr_t symbolAddress;
804 if ( context.bindFlat || (libraryOrdinal == BIND_SPECIAL_DYLIB_FLAT_LOOKUP) ) {
805 symbolAddress = this->resolveFlat(context, symbolName, weak_import, runResolver, targetImage);
806 }
807 else if ( libraryOrdinal == BIND_SPECIAL_DYLIB_WEAK_LOOKUP ) {
808 symbolAddress = this->resolveWeak(context, symbolName, weak_import, runResolver, targetImage, patcher);
809 }
810 else {
811 if ( libraryOrdinal == BIND_SPECIAL_DYLIB_MAIN_EXECUTABLE ) {
812 *targetImage = context.mainExecutable;
813 }
814 else if ( libraryOrdinal == BIND_SPECIAL_DYLIB_SELF ) {
815 *targetImage = this;
816 }
817 else if ( libraryOrdinal <= 0 ) {
818 dyld::throwf("bad mach-o binary, unknown special library ordinal (%ld) too big for symbol %s in %s",
819 libraryOrdinal, symbolName, this->getPath());
820 }
821 else if ( (unsigned)libraryOrdinal <= libraryCount() ) {
822 *targetImage = libImage((unsigned int)libraryOrdinal-1);
823 }
824 else {
825 dyld::throwf("bad mach-o binary, library ordinal (%ld) too big (max %u) for symbol %s in %s",
826 libraryOrdinal, libraryCount(), symbolName, this->getPath());
827 }
828 if ( *targetImage == NULL ) {
829 if ( weak_import ) {
830 // if target library not loaded and reference is weak or library is weak return 0
831 symbolAddress = 0;
832 }
833 else {
834 // Try get the path from the load commands
835 if ( const char* depPath = libPath((unsigned int)libraryOrdinal-1) ) {
836 dyld::throwf("can't resolve symbol %s in %s because dependent dylib %s could not be loaded",
837 symbolName, this->getPath(), depPath);
838 } else {
839 dyld::throwf("can't resolve symbol %s in %s because dependent dylib #%ld could not be loaded",
840 symbolName, this->getPath(), libraryOrdinal);
841 }
842 }
843 }
844 else {
845 symbolAddress = resolveTwolevel(context, symbolName, *targetImage, this, (unsigned)libraryOrdinal, weak_import, runResolver, targetImage);
846 }
847 }
848
849 // save off lookup results if client wants
850 if ( last != NULL ) {
851 last->ordinal = libraryOrdinal;
852 last->flags = symboFlags;
853 last->name = symbolName;
854 last->foundIn = *targetImage;
855 last->result = symbolAddress;
856 }
857
858 return symbolAddress;
859 }
860
861 uintptr_t ImageLoaderMachOCompressed::bindAt(const LinkContext& context, ImageLoaderMachOCompressed* image,
862 uintptr_t addr, uint8_t type, const char* symbolName,
863 uint8_t symbolFlags, intptr_t addend, long libraryOrdinal,
864 ExtraBindData *extraBindData,
865 const char* msg, DyldSharedCache::DataConstLazyScopedWriter& patcher,
866 LastLookup* last, bool runResolver)
867 {
868 const ImageLoader* targetImage;
869 uintptr_t symbolAddress;
870
871 // resolve symbol
872 if (type == BIND_TYPE_THREADED_REBASE) {
873 symbolAddress = 0;
874 targetImage = nullptr;
875 } else
876 symbolAddress = image->resolve(context, symbolName, symbolFlags, libraryOrdinal, &targetImage, patcher, last, runResolver);
877
878 // do actual update
879 return image->bindLocation(context, image->imageBaseAddress(), addr, symbolAddress, type, symbolName, addend, image->getPath(), targetImage ? targetImage->getPath() : NULL, msg, extraBindData, image->fSlide);
880 }
881
882
883 void ImageLoaderMachOCompressed::throwBadBindingAddress(uintptr_t address, uintptr_t segmentEndAddress, int segmentIndex,
884 const uint8_t* startOpcodes, const uint8_t* endOpcodes, const uint8_t* pos)
885 {
886 dyld::throwf("malformed binding opcodes (%ld/%ld): address 0x%08lX is outside segment %s (0x%08lX -> 0x%08lX)",
887 (intptr_t)(pos-startOpcodes), (intptr_t)(endOpcodes-startOpcodes), address, segName(segmentIndex),
888 segActualLoadAddress(segmentIndex), segmentEndAddress);
889 }
890
891 void ImageLoaderMachOCompressed::doBind(const LinkContext& context, bool forceLazysBound, const ImageLoader* reExportParent)
892 {
893 CRSetCrashLogMessage2(this->getPath());
894
895 // if prebound and loaded at prebound address, and all libraries are same as when this was prebound, then no need to bind
896 // note: flat-namespace binaries need to have imports rebound (even if correctly prebound)
897 if ( this->usablePrebinding(context) ) {
898 // don't need to bind
899 // except weak which may now be inline with the regular binds
900 if ( this->participatesInCoalescing() && (fDyldInfo != nullptr) ) {
901 // run through all binding opcodes
902 DyldSharedCache::DataConstLazyScopedWriter patcher(context.dyldCache, mach_task_self(), context.verboseMapping ? &dyld::log : nullptr);
903 auto* patcherPtr = &patcher;
904 eachBind(context, ^(const LinkContext& ctx, ImageLoaderMachOCompressed* image,
905 uintptr_t addr, uint8_t type, const char* symbolName,
906 uint8_t symbolFlags, intptr_t addend, long libraryOrdinal,
907 ExtraBindData *extraBindData,
908 const char* msg, LastLookup* last, bool runResolver) {
909 if ( libraryOrdinal != BIND_SPECIAL_DYLIB_WEAK_LOOKUP )
910 return (uintptr_t)0;
911 return ImageLoaderMachOCompressed::bindAt(ctx, image, addr, type, symbolName, symbolFlags,
912 addend, libraryOrdinal, extraBindData,
913 msg, *patcherPtr, last, runResolver);
914 });
915 }
916 }
917 else {
918 uint64_t t0 = mach_absolute_time();
919
920 uint32_t ignore;
921 bool bindingBecauseOfRoot = ( this->overridesCachedDylib(ignore) || this->inSharedCache() );
922 vmAccountingSetSuspended(context, bindingBecauseOfRoot);
923
924 if ( fChainedFixups != NULL ) {
925 DyldSharedCache::DataConstLazyScopedWriter patcher(context.dyldCache, mach_task_self(), context.verboseMapping ? &dyld::log : nullptr);
926 const dyld_chained_fixups_header* fixupsHeader = (dyld_chained_fixups_header*)(fLinkEditBase + fChainedFixups->dataoff);
927 doApplyFixups(context, fixupsHeader, patcher);
928 }
929 else if ( fDyldInfo != nullptr ) {
930 #if TEXT_RELOC_SUPPORT
931 // if there are __TEXT fixups, temporarily make __TEXT writable
932 if ( fTextSegmentBinds )
933 this->makeTextSegmentWritable(context, true);
934 #endif
935
936 // make the cache writable for this block
937 DyldSharedCache::DataConstLazyScopedWriter patcher(context.dyldCache, mach_task_self(), context.verboseMapping ? &dyld::log : nullptr);
938 auto* patcherPtr = &patcher;
939 if ( this->inSharedCache() )
940 patcher.makeWriteable();
941
942 // run through all binding opcodes
943 eachBind(context, ^(const LinkContext& ctx, ImageLoaderMachOCompressed* image,
944 uintptr_t addr, uint8_t type, const char* symbolName,
945 uint8_t symbolFlags, intptr_t addend, long libraryOrdinal,
946 ExtraBindData *extraBindData,
947 const char* msg, LastLookup* last, bool runResolver) {
948 return ImageLoaderMachOCompressed::bindAt(ctx, image, addr, type, symbolName, symbolFlags,
949 addend, libraryOrdinal, extraBindData,
950 msg, *patcherPtr, last, runResolver);
951 });
952
953 #if TEXT_RELOC_SUPPORT
954 // if there were __TEXT fixups, restore write protection
955 if ( fTextSegmentBinds )
956 this->makeTextSegmentWritable(context, false);
957 #endif
958
959 // if this image is in the shared cache, but depends on something no longer in the shared cache,
960 // there is no way to reset the lazy pointers, so force bind them now
961 if ( forceLazysBound || fInSharedCache )
962 this->doBindJustLazies(context, patcher);
963
964 // this image is in cache, but something below it is not. If
965 // this image has lazy pointer to a resolver function, then
966 // the stub may have been altered to point to a shared lazy pointer.
967 if ( fInSharedCache )
968 this->updateOptimizedLazyPointers(context);
969 }
970
971 uint64_t t1 = mach_absolute_time();
972 ImageLoader::fgTotalRebindCacheTime += (t1-t0);
973 }
974
975 // See if this dylib overrides something in the dyld cache
976 uint32_t dyldCacheOverrideImageNum;
977 if ( context.dyldCache && context.dyldCache->header.builtFromChainedFixups && overridesCachedDylib(dyldCacheOverrideImageNum) ) {
978
979 // make the cache writable for this block
980 DyldSharedCache::DataConstLazyScopedWriter patcher(context.dyldCache, mach_task_self(), context.verboseMapping ? &dyld::log : nullptr);
981 auto* patcherPtr = &patcher;
982
983 // need to patch all other places in cache that point to the overridden dylib, to point to this dylib instead
984 const dyld3::closure::Image* overriddenImage = context.dyldCache->cachedDylibsImageArray()->imageForNum(dyldCacheOverrideImageNum);
985 uint32_t imageIndex = dyldCacheOverrideImageNum - (uint32_t)context.dyldCache->cachedDylibsImageArray()->startImageNum();
986 //dyld::log("doBind() found override of %s\n", this->getPath());
987 context.dyldCache->forEachPatchableExport(imageIndex, ^(uint32_t cacheOffsetOfImpl, const char* exportName) {
988 uintptr_t newImpl = 0;
989 const ImageLoader* foundIn = nullptr;
990 if ( this->findExportedSymbolAddress(context, exportName, NULL, 0, false, &foundIn, &newImpl) ) {
991 //dyld::log(" patchCacheUsesOf(%s) found in %s\n", exportName, foundIn->getPath());
992 patchCacheUsesOf(context, overriddenImage, cacheOffsetOfImpl, exportName, newImpl, *patcherPtr);
993 }
994 else {
995 // <rdar://problem/59196856> allow patched impls to move between re-export sibling dylibs
996 if ( reExportParent != nullptr ) {
997 reExportParent->forEachReExportDependent(^(const ImageLoader* reExportedDep, bool& stop) {
998 uintptr_t siblingImpl = 0;
999 const ImageLoader* foundInSibling = nullptr;
1000 if ( reExportedDep->findExportedSymbolAddress(context, exportName, NULL, 0, false, &foundInSibling, &siblingImpl) ) {
1001 stop = true;
1002 //dyld::log(" patchCacheUsesOf(%s) found in sibling %s\n", exportName, foundInSibling->getPath());
1003 patchCacheUsesOf(context, overriddenImage, cacheOffsetOfImpl, exportName, siblingImpl, *patcherPtr);
1004 }
1005 });
1006 }
1007 }
1008 });
1009 }
1010
1011 // set up dyld entry points in image
1012 // do last so flat main executables will have __dyld or __program_vars set up
1013 this->setupLazyPointerHandler(context);
1014 CRSetCrashLogMessage2(NULL);
1015 }
1016
1017
1018 void ImageLoaderMachOCompressed::doBindJustLazies(const LinkContext& context, DyldSharedCache::DataConstLazyScopedWriter& patcher)
1019 {
1020 eachLazyBind(context, ^(const LinkContext& ctx, ImageLoaderMachOCompressed* image,
1021 uintptr_t addr, uint8_t type, const char* symbolName,
1022 uint8_t symbolFlags, intptr_t addend, long libraryOrdinal,
1023 ExtraBindData *extraBindData,
1024 const char* msg, LastLookup* last, bool runResolver) {
1025 return ImageLoaderMachOCompressed::bindAt(ctx, image, addr, type, symbolName, symbolFlags,
1026 addend, libraryOrdinal, extraBindData,
1027 msg, patcher, last, runResolver);
1028 });
1029 }
1030
1031 void ImageLoaderMachOCompressed::doApplyFixups(const LinkContext& context, const dyld_chained_fixups_header* fixupsHeader,
1032 DyldSharedCache::DataConstLazyScopedWriter& patcher)
1033 {
1034 const dyld3::MachOLoaded* ml = (dyld3::MachOLoaded*)machHeader();
1035 const dyld_chained_starts_in_image* starts = (dyld_chained_starts_in_image*)((uint8_t*)fixupsHeader + fixupsHeader->starts_offset);
1036
1037 // build table of resolved targets for each symbol ordinal
1038 STACK_ALLOC_OVERFLOW_SAFE_ARRAY(const void*, targetAddrs, 128);
1039 targetAddrs.reserve(fixupsHeader->imports_count);
1040 __block Diagnostics diag;
1041 const dyld3::MachOAnalyzer* ma = (dyld3::MachOAnalyzer*)ml;
1042 ma->forEachChainedFixupTarget(diag, ^(int libOrdinal, const char* symbolName, uint64_t addend, bool weakImport, bool& stop) {
1043 const ImageLoader* targetImage;
1044 uint8_t symbolFlags = weakImport ? BIND_SYMBOL_FLAGS_WEAK_IMPORT : 0;
1045 try {
1046 uintptr_t symbolAddress = this->resolve(context, symbolName, symbolFlags, libOrdinal, &targetImage, patcher, NULL, true);
1047 targetAddrs.push_back((void*)(symbolAddress + addend));
1048 }
1049 catch (const char* msg) {
1050 stop = true;
1051 diag.error("%s", msg);
1052 }
1053 });
1054 if ( diag.hasError() )
1055 throw strdup(diag.errorMessage());
1056
1057 auto logFixups = ^(void* loc, void* newValue) {
1058 dyld::log("dyld: fixup: %s:%p = %p\n", this->getShortName(), loc, newValue);
1059 };
1060 if ( !context.verboseBind )
1061 logFixups = nullptr;
1062
1063 ml->fixupAllChainedFixups(diag, starts, fSlide, targetAddrs, logFixups);
1064 if ( diag.hasError() )
1065 throw strdup(diag.errorMessage());
1066 }
1067
1068 void ImageLoaderMachOCompressed::registerInterposing(const LinkContext& context)
1069 {
1070 // mach-o files advertise interposing by having a __DATA __interpose section
1071 struct InterposeData { uintptr_t replacement; uintptr_t replacee; };
1072
1073 // FIDME: It seems wrong to need a patcher here, but resolve may call resolveWeak and patch the cache.
1074 // That would require weak symbols in the interposing section though, which may not be supported.
1075 DyldSharedCache::DataConstLazyScopedWriter patcher(context.dyldCache, mach_task_self(), context.verboseMapping ? &dyld::log : nullptr);
1076 auto* patcherPtr = &patcher;
1077
1078 __block Diagnostics diag;
1079 const dyld3::MachOAnalyzer* ma = (dyld3::MachOAnalyzer*)fMachOData;
1080 ma->forEachInterposingSection(diag, ^(uint64_t vmOffset, uint64_t vmSize, bool& stopSections) {
1081 if ( ma->hasChainedFixups() ) {
1082 const uint16_t pointerFormat = ma->chainedPointerFormat();
1083 const uint8_t* sectionStart = fMachOData+vmOffset;
1084 const uint8_t* sectionEnd = fMachOData+vmOffset+vmSize;
1085 ma->withChainStarts(diag, ma->chainStartsOffset(), ^(const dyld_chained_starts_in_image* startsInfo) {
1086 __block uintptr_t lastRebaseTarget = 0;
1087 ma->forEachFixupInAllChains(diag, startsInfo, false, ^(dyld3::MachOLoaded::ChainedFixupPointerOnDisk* fixupLoc, const dyld_chained_starts_in_segment* segInfo, bool& stopFixups) {
1088 if ( ((uint8_t*)fixupLoc < sectionStart) || ((uint8_t*)fixupLoc >= sectionEnd) )
1089 return;
1090 uint64_t rebaseTargetRuntimeOffset;
1091 uint32_t bindOrdinal;
1092 int64_t ptrAddend;
1093 if ( fixupLoc->isRebase(pointerFormat, 0, rebaseTargetRuntimeOffset) ) {
1094 //dyld::log("interpose rebase at fixup at %p to 0x%0llX\n", fixupLoc, rebaseTargetRuntimeOffset);
1095 lastRebaseTarget = (uintptr_t)(fMachOData+rebaseTargetRuntimeOffset);
1096 }
1097 else if ( fixupLoc->isBind(pointerFormat, bindOrdinal, ptrAddend) ) {
1098 //dyld::log("interpose bind fixup at %p to bind ordinal %d\n", fixupLoc, bindOrdinal);
1099 __block uint32_t targetBindIndex = 0;
1100 ma->forEachChainedFixupTarget(diag, ^(int libraryOrdinal, const char* symbolName, uint64_t addend, bool weakImport, bool& stop) {
1101 if ( targetBindIndex == bindOrdinal ) {
1102 //dyld::log("interpose bind fixup at %p is to %s libOrdinal=%d\n", fixupLoc, symbolName, libraryOrdinal);
1103 LastLookup* last = NULL;
1104 const ImageLoader* targetImage;
1105 uintptr_t targetBindAddress = 0;
1106 try {
1107 targetBindAddress = this->resolve(context, symbolName, 0, libraryOrdinal, &targetImage, *patcherPtr, last, false);
1108 }
1109 catch (const char* msg) {
1110 if ( !weakImport )
1111 throw msg;
1112 targetBindAddress = 0;
1113 }
1114 //dyld::log("interpose bind fixup at %p is bound to 0x%lX\n", fixupLoc, targetBindAddress);
1115 // <rdar://problem/25686570> ignore interposing on a weak function that does not exist
1116 if ( targetBindAddress == 0 )
1117 return;
1118 ImageLoader::InterposeTuple tuple;
1119 tuple.replacement = lastRebaseTarget;
1120 tuple.neverImage = this;
1121 tuple.onlyImage = NULL;
1122 tuple.replacee = targetBindAddress;
1123 // <rdar://problem/7937695> verify that replacement is in this image
1124 if ( this->containsAddress((void*)tuple.replacement) ) {
1125 if ( context.verboseInterposing )
1126 dyld::log("dyld: interposing 0x%lx with 0x%lx\n", tuple.replacee, tuple.replacement);
1127 // chain to any existing interpositions
1128 for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
1129 if ( it->replacee == tuple.replacee ) {
1130 tuple.replacee = it->replacement;
1131 }
1132 }
1133 ImageLoader::fgInterposingTuples.push_back(tuple);
1134 }
1135 }
1136 ++targetBindIndex;
1137 });
1138 }
1139 });
1140 });
1141 }
1142 else {
1143 // traditional (non-chained) fixups
1144 const size_t count = (size_t)(vmSize / sizeof(InterposeData));
1145 const InterposeData* interposeArray = (InterposeData*)(fMachOData+vmOffset);
1146 if ( context.verboseInterposing )
1147 dyld::log("dyld: found %lu interposing tuples in %s\n", count, getPath());
1148 for (size_t j=0; j < count; ++j) {
1149 uint64_t bindOffset = ((uint8_t*)&(interposeArray[j].replacee)) - fMachOData;
1150 ma->forEachBind(diag, ^(uint64_t runtimeOffset, int libOrdinal, const char* symbolName, bool weakImport, bool lazyBind, uint64_t addend, bool& stopBinds) {
1151 if ( bindOffset != runtimeOffset )
1152 return;
1153 stopBinds = true;
1154 LastLookup* last = NULL;
1155 const ImageLoader* targetImage;
1156 uintptr_t targetBindAddress = 0;
1157 try {
1158 targetBindAddress = this->resolve(context, symbolName, 0, libOrdinal, &targetImage, *patcherPtr, last, false);
1159 }
1160 catch (const char* msg) {
1161 if ( !weakImport )
1162 throw msg;
1163 targetBindAddress = 0;
1164 }
1165 ImageLoader::InterposeTuple tuple;
1166 tuple.replacement = interposeArray[j].replacement;
1167 tuple.neverImage = this;
1168 tuple.onlyImage = NULL;
1169 tuple.replacee = targetBindAddress;
1170 // <rdar://problem/25686570> ignore interposing on a weak function that does not exist
1171 if ( tuple.replacee == 0 )
1172 return;
1173 // <rdar://problem/7937695> verify that replacement is in this image
1174 if ( this->containsAddress((void*)tuple.replacement) ) {
1175 if ( context.verboseInterposing )
1176 dyld::log("dyld: interposing 0x%lx with 0x%lx\n", tuple.replacee, tuple.replacement);
1177 // chain to any existing interpositions
1178 for (std::vector<InterposeTuple>::iterator it=fgInterposingTuples.begin(); it != fgInterposingTuples.end(); it++) {
1179 if ( it->replacee == tuple.replacee ) {
1180 tuple.replacee = it->replacement;
1181 }
1182 }
1183 ImageLoader::fgInterposingTuples.push_back(tuple);
1184 }
1185 }, ^(const char* symbolName){
1186 });
1187 }
1188 }
1189 });
1190 }
1191
1192 bool ImageLoaderMachOCompressed::usesChainedFixups() const
1193 {
1194 return ((dyld3::MachOLoaded*)machHeader())->hasChainedFixups();
1195 }
1196
1197 struct ThreadedBindData {
1198 ThreadedBindData(const char* symbolName, int64_t addend, long libraryOrdinal, uint8_t symbolFlags, uint8_t type)
1199 : symbolName(symbolName), addend(addend), libraryOrdinal(libraryOrdinal), symbolFlags(symbolFlags), type(type) { }
1200
1201 std::tuple<const char*, int64_t, long, bool, uint8_t> pack() const {
1202 return std::make_tuple(symbolName, addend, libraryOrdinal, symbolFlags, type);
1203 }
1204
1205 const char* symbolName = nullptr;
1206 int64_t addend = 0;
1207 long libraryOrdinal = 0;
1208 uint8_t symbolFlags = 0;
1209 uint8_t type = 0;
1210 };
1211
1212 void ImageLoaderMachOCompressed::makeDataReadOnly() const
1213 {
1214 #if !TEXT_RELOC_SUPPORT
1215 if ( fReadOnlyDataSegment && !this->ImageLoader::inSharedCache() ) {
1216 for (unsigned int i=0; i < fSegmentsCount; ++i) {
1217 if ( segIsReadOnlyData(i) ) {
1218 uintptr_t start = segActualLoadAddress(i);
1219 uintptr_t size = segSize(i);
1220 #if defined(__x86_64__) && !TARGET_OS_SIMULATOR
1221 if ( dyld::isTranslated() ) {
1222 // <rdar://problem/48325338> can't mprotect non-16KB segments
1223 if ( ((size & 0x3FFF) != 0) || ((start & 0x3FFF) != 0) )
1224 continue;
1225 }
1226 #endif
1227 ::mprotect((void*)start, size, PROT_READ);
1228 //dyld::log("make read-only 0x%09lX -> 0x%09lX\n", (long)start, (long)(start+size));
1229 }
1230 }
1231 }
1232 #endif
1233 }
1234
1235
1236 void ImageLoaderMachOCompressed::eachBind(const LinkContext& context, bind_handler handler)
1237 {
1238 try {
1239 uint8_t type = 0;
1240 int segmentIndex = -1;
1241 uintptr_t address = segActualLoadAddress(0);
1242 uintptr_t segmentStartAddress = segActualLoadAddress(0);
1243 uintptr_t segmentEndAddress = segActualEndAddress(0);
1244 const char* symbolName = NULL;
1245 uint8_t symboFlags = 0;
1246 bool libraryOrdinalSet = false;
1247 long libraryOrdinal = 0;
1248 intptr_t addend = 0;
1249 uintptr_t count;
1250 uintptr_t skip;
1251 uintptr_t segOffset = 0;
1252
1253 dyld3::OverflowSafeArray<ThreadedBindData> ordinalTable;
1254 bool useThreadedRebaseBind = false;
1255 ExtraBindData extraBindData;
1256 LastLookup last = { 0, 0, NULL, 0, NULL };
1257 const uint8_t* const start = fLinkEditBase + fDyldInfo->bind_off;
1258 const uint8_t* const end = &start[fDyldInfo->bind_size];
1259 const uint8_t* p = start;
1260 bool done = false;
1261 while ( !done && (p < end) ) {
1262 uint8_t immediate = *p & BIND_IMMEDIATE_MASK;
1263 uint8_t opcode = *p & BIND_OPCODE_MASK;
1264 ++p;
1265 switch (opcode) {
1266 case BIND_OPCODE_DONE:
1267 done = true;
1268 break;
1269 case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM:
1270 libraryOrdinal = immediate;
1271 libraryOrdinalSet = true;
1272 break;
1273 case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:
1274 libraryOrdinal = read_uleb128(p, end);
1275 libraryOrdinalSet = true;
1276 break;
1277 case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM:
1278 // the special ordinals are negative numbers
1279 if ( immediate == 0 )
1280 libraryOrdinal = 0;
1281 else {
1282 int8_t signExtended = BIND_OPCODE_MASK | immediate;
1283 libraryOrdinal = signExtended;
1284 }
1285 libraryOrdinalSet = true;
1286 break;
1287 case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
1288 symbolName = (char*)p;
1289 symboFlags = immediate;
1290 while (*p != '\0')
1291 ++p;
1292 ++p;
1293 break;
1294 case BIND_OPCODE_SET_TYPE_IMM:
1295 type = immediate;
1296 break;
1297 case BIND_OPCODE_SET_ADDEND_SLEB:
1298 addend = read_sleb128(p, end);
1299 break;
1300 case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
1301 segmentIndex = immediate;
1302 if ( (segmentIndex >= fSegmentsCount) || (segmentIndex < 0) )
1303 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is out of range (0..%d)",
1304 segmentIndex, fSegmentsCount-1);
1305 #if TEXT_RELOC_SUPPORT
1306 if ( !segWriteable(segmentIndex) && !segHasRebaseFixUps(segmentIndex) && !segHasBindFixUps(segmentIndex) )
1307 #else
1308 if ( !segWriteable(segmentIndex) )
1309 #endif
1310 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is not writable", segmentIndex);
1311 segOffset = read_uleb128(p, end);
1312 if ( segOffset > segSize(segmentIndex) )
1313 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has offset 0x%08lX beyond segment size (0x%08lX)", segOffset, segSize(segmentIndex));
1314 segmentStartAddress = segActualLoadAddress(segmentIndex);
1315 address = segmentStartAddress + segOffset;
1316 segmentEndAddress = segActualEndAddress(segmentIndex);
1317 break;
1318 case BIND_OPCODE_ADD_ADDR_ULEB:
1319 address += read_uleb128(p, end);
1320 break;
1321 case BIND_OPCODE_DO_BIND:
1322 if (!useThreadedRebaseBind) {
1323 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
1324 throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, p);
1325 if ( symbolName == NULL )
1326 dyld::throwf("BIND_OPCODE_DO_BIND missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM");
1327 if ( segmentIndex == -1 )
1328 dyld::throwf("BIND_OPCODE_DO_BIND missing preceding BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB");
1329 if ( !libraryOrdinalSet )
1330 dyld::throwf("BIND_OPCODE_DO_BIND missing preceding BIND_OPCODE_SET_DYLIB_ORDINAL*");
1331 handler(context, this, address, type, symbolName, symboFlags, addend, libraryOrdinal,
1332 &extraBindData, "", &last, false);
1333 address += sizeof(intptr_t);
1334 } else {
1335 ordinalTable.push_back(ThreadedBindData(symbolName, addend, libraryOrdinal, symboFlags, type));
1336 }
1337 break;
1338 case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
1339 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
1340 throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, p);
1341 if ( symbolName == NULL )
1342 dyld::throwf("BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM");
1343 if ( segmentIndex == -1 )
1344 dyld::throwf("BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB missing preceding BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB");
1345 if ( !libraryOrdinalSet )
1346 dyld::throwf("BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB missing preceding BIND_OPCODE_SET_DYLIB_ORDINAL*");
1347 handler(context, this, address, type, symbolName, symboFlags, addend, libraryOrdinal,
1348 &extraBindData, "", &last, false);
1349 address += read_uleb128(p, end) + sizeof(intptr_t);
1350 break;
1351 case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
1352 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
1353 throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, p);
1354 if ( symbolName == NULL )
1355 dyld::throwf("BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM");
1356 if ( segmentIndex == -1 )
1357 dyld::throwf("BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED missing preceding BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB");
1358 if ( !libraryOrdinalSet )
1359 dyld::throwf("BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED missing preceding BIND_OPCODE_SET_DYLIB_ORDINAL*");
1360 handler(context, this, address, type, symbolName, symboFlags, addend, libraryOrdinal,
1361 &extraBindData, "", &last, false);
1362 address += immediate*sizeof(intptr_t) + sizeof(intptr_t);
1363 break;
1364 case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
1365 if ( symbolName == NULL )
1366 dyld::throwf("BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM");
1367 if ( segmentIndex == -1 )
1368 dyld::throwf("BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB missing preceding BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB");
1369 count = read_uleb128(p, end);
1370 if ( !libraryOrdinalSet )
1371 dyld::throwf("BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB missing preceding BIND_OPCODE_SET_DYLIB_ORDINAL*");
1372 skip = read_uleb128(p, end);
1373 for (uint32_t i=0; i < count; ++i) {
1374 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
1375 throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, p);
1376 handler(context, this, address, type, symbolName, symboFlags, addend, libraryOrdinal,
1377 &extraBindData, "", &last, false);
1378 address += skip + sizeof(intptr_t);
1379 }
1380 break;
1381 case BIND_OPCODE_THREADED:
1382 if (sizeof(intptr_t) != 8) {
1383 dyld::throwf("BIND_OPCODE_THREADED require 64-bit");
1384 return;
1385 }
1386 // Note the immediate is a sub opcode
1387 switch (immediate) {
1388 case BIND_SUBOPCODE_THREADED_SET_BIND_ORDINAL_TABLE_SIZE_ULEB:
1389 count = read_uleb128(p, end);
1390 ordinalTable.clear();
1391 // FIXME: ld64 wrote the wrong value here and we need to offset by 1 for now.
1392 ordinalTable.reserve(count + 1);
1393 useThreadedRebaseBind = true;
1394 break;
1395 case BIND_SUBOPCODE_THREADED_APPLY: {
1396 uint64_t delta = 0;
1397 do {
1398 address = segmentStartAddress + segOffset;
1399 uint64_t value = *(uint64_t*)address;
1400
1401
1402 bool isRebase = (value & (1ULL << 62)) == 0;
1403 if (isRebase) {
1404 {
1405 // Call the bind handler which knows about our bind type being set to rebase
1406 handler(context, this, address, BIND_TYPE_THREADED_REBASE, nullptr, 0, 0, 0,
1407 nullptr, "", &last, false);
1408 }
1409 } else {
1410 // the ordinal is bits [0..15]
1411 uint16_t ordinal = value & 0xFFFF;
1412 if (ordinal >= ordinalTable.count()) {
1413 dyld::throwf("bind ordinal (%d) is out of range (max=%lu) for disk pointer 0x%16llX at segIndex=%d, segOffset=0x%0lX in %s",
1414 ordinal, ordinalTable.count(),value, segmentIndex, segOffset, this->getPath());
1415 return;
1416 }
1417 std::tie(symbolName, addend, libraryOrdinal, symboFlags, type) = ordinalTable[ordinal].pack();
1418 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
1419 throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, p);
1420 {
1421 handler(context, this, address, BIND_TYPE_THREADED_BIND,
1422 symbolName, symboFlags, addend, libraryOrdinal,
1423 nullptr, "", &last, false);
1424 }
1425 }
1426
1427 // The delta is bits [51..61]
1428 // And bit 62 is to tell us if we are a rebase (0) or bind (1)
1429 value &= ~(1ULL << 62);
1430 delta = ( value & 0x3FF8000000000000 ) >> 51;
1431 segOffset += delta * sizeof(intptr_t);
1432 } while ( delta != 0 );
1433 break;
1434 }
1435
1436 default:
1437 dyld::throwf("bad threaded bind subopcode 0x%02X", *p);
1438 }
1439 break;
1440 default:
1441 dyld::throwf("bad bind opcode %d in bind info", *p);
1442 }
1443 }
1444 }
1445 catch (const char* msg) {
1446 const char* newMsg = dyld::mkstringf("%s in %s", msg, this->getPath());
1447 free((void*)msg);
1448 throw newMsg;
1449 }
1450 }
1451
1452 void ImageLoaderMachOCompressed::eachLazyBind(const LinkContext& context, bind_handler handler)
1453 {
1454 try {
1455 uint8_t type = BIND_TYPE_POINTER;
1456 int segmentIndex = -1;
1457 uintptr_t address = segActualLoadAddress(0);
1458 uintptr_t segmentStartAddress = segActualLoadAddress(0);
1459 uintptr_t segmentEndAddress = segActualEndAddress(0);
1460 uintptr_t segOffset;
1461 const char* symbolName = NULL;
1462 uint8_t symboFlags = 0;
1463 long libraryOrdinal = 0;
1464 intptr_t addend = 0;
1465 const uint8_t* const start = fLinkEditBase + fDyldInfo->lazy_bind_off;
1466 const uint8_t* const end = &start[fDyldInfo->lazy_bind_size];
1467 const uint8_t* p = start;
1468 bool done = false;
1469 while ( !done && (p < end) ) {
1470 uint8_t immediate = *p & BIND_IMMEDIATE_MASK;
1471 uint8_t opcode = *p & BIND_OPCODE_MASK;
1472 ++p;
1473 switch (opcode) {
1474 case BIND_OPCODE_DONE:
1475 // there is BIND_OPCODE_DONE at end of each lazy bind, don't stop until end of whole sequence
1476 break;
1477 case BIND_OPCODE_SET_DYLIB_ORDINAL_IMM:
1478 libraryOrdinal = immediate;
1479 break;
1480 case BIND_OPCODE_SET_DYLIB_ORDINAL_ULEB:
1481 libraryOrdinal = read_uleb128(p, end);
1482 break;
1483 case BIND_OPCODE_SET_DYLIB_SPECIAL_IMM:
1484 // the special ordinals are negative numbers
1485 if ( immediate == 0 )
1486 libraryOrdinal = 0;
1487 else {
1488 int8_t signExtended = BIND_OPCODE_MASK | immediate;
1489 libraryOrdinal = signExtended;
1490 }
1491 break;
1492 case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
1493 symbolName = (char*)p;
1494 symboFlags = immediate;
1495 while (*p != '\0')
1496 ++p;
1497 ++p;
1498 break;
1499 case BIND_OPCODE_SET_TYPE_IMM:
1500 type = immediate;
1501 break;
1502 case BIND_OPCODE_SET_ADDEND_SLEB:
1503 addend = read_sleb128(p, end);
1504 break;
1505 case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
1506 segmentIndex = immediate;
1507 if ( (segmentIndex >= fSegmentsCount) || (segmentIndex < 0) )
1508 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is out of range (0..%d)",
1509 segmentIndex, fSegmentsCount-1);
1510 if ( !segWriteable(segmentIndex) )
1511 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is not writable", segmentIndex);
1512 segOffset = read_uleb128(p, end);
1513 if ( segOffset > segSize(segmentIndex) )
1514 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has offset 0x%08lX beyond segment size (0x%08lX)", segOffset, segSize(segmentIndex));
1515 segmentStartAddress = segActualLoadAddress(segmentIndex);
1516 segmentEndAddress = segActualEndAddress(segmentIndex);
1517 address = segmentStartAddress + segOffset;
1518 break;
1519 case BIND_OPCODE_ADD_ADDR_ULEB:
1520 address += read_uleb128(p, end);
1521 break;
1522 case BIND_OPCODE_DO_BIND:
1523 if ( segmentIndex == -1 )
1524 dyld::throwf("BIND_OPCODE_DO_BIND missing preceding BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB");
1525 if ( (address < segmentStartAddress) || (address >= segmentEndAddress) )
1526 throwBadBindingAddress(address, segmentEndAddress, segmentIndex, start, end, p);
1527 if ( symbolName == NULL )
1528 dyld::throwf("BIND_OPCODE_DO_BIND missing preceding BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM");
1529 handler(context, this, address, type, symbolName, symboFlags, addend, libraryOrdinal,
1530 NULL, "forced lazy ", NULL, false);
1531 address += sizeof(intptr_t);
1532 break;
1533 case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
1534 case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
1535 case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
1536 default:
1537 dyld::throwf("bad lazy bind opcode %d", *p);
1538 }
1539 }
1540 }
1541
1542 catch (const char* msg) {
1543 const char* newMsg = dyld::mkstringf("%s in %s", msg, this->getPath());
1544 free((void*)msg);
1545 throw newMsg;
1546 }
1547 }
1548
1549 // A program built targeting 10.5 will have hybrid stubs. When used with weak symbols
1550 // the classic lazy loader is used even when running on 10.6
1551 uintptr_t ImageLoaderMachOCompressed::doBindLazySymbol(uintptr_t* lazyPointer, const LinkContext& context,
1552 DyldSharedCache::DataConstLazyScopedWriter& patcher)
1553 {
1554 // only works with compressed LINKEDIT if classic symbol table is also present
1555 const macho_nlist* symbolTable = NULL;
1556 const char* symbolTableStrings = NULL;
1557 const dysymtab_command* dynSymbolTable = NULL;
1558 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1559 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1560 const struct load_command* cmd = cmds;
1561 for (uint32_t i = 0; i < cmd_count; ++i) {
1562 switch (cmd->cmd) {
1563 case LC_SYMTAB:
1564 {
1565 const struct symtab_command* symtab = (struct symtab_command*)cmd;
1566 symbolTableStrings = (const char*)&fLinkEditBase[symtab->stroff];
1567 symbolTable = (macho_nlist*)(&fLinkEditBase[symtab->symoff]);
1568 }
1569 break;
1570 case LC_DYSYMTAB:
1571 dynSymbolTable = (struct dysymtab_command*)cmd;
1572 break;
1573 }
1574 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1575 }
1576 // no symbol table => no lookup by address
1577 if ( (symbolTable == NULL) || (dynSymbolTable == NULL) )
1578 dyld::throwf("classic lazy binding used with compressed LINKEDIT at %p in image %s", lazyPointer, this->getPath());
1579
1580 // scan for all lazy-pointer sections
1581 const bool twoLevel = this->usesTwoLevelNameSpace();
1582 const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[dynSymbolTable->indirectsymoff];
1583 cmd = cmds;
1584 for (uint32_t i = 0; i < cmd_count; ++i) {
1585 switch (cmd->cmd) {
1586 case LC_SEGMENT_COMMAND:
1587 {
1588 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
1589 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
1590 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
1591 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
1592 const uint8_t type = sect->flags & SECTION_TYPE;
1593 uint32_t symbolIndex = INDIRECT_SYMBOL_LOCAL;
1594 if ( type == S_LAZY_SYMBOL_POINTERS ) {
1595 const size_t pointerCount = sect->size / sizeof(uintptr_t);
1596 uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
1597 if ( (lazyPointer >= symbolPointers) && (lazyPointer < &symbolPointers[pointerCount]) ) {
1598 const uint32_t indirectTableOffset = sect->reserved1;
1599 const size_t lazyIndex = lazyPointer - symbolPointers;
1600 symbolIndex = indirectTable[indirectTableOffset + lazyIndex];
1601 }
1602 }
1603 if ( (symbolIndex != INDIRECT_SYMBOL_ABS) && (symbolIndex != INDIRECT_SYMBOL_LOCAL) ) {
1604 const macho_nlist* symbol = &symbolTable[symbolIndex];
1605 const char* symbolName = &symbolTableStrings[symbol->n_un.n_strx];
1606 int libraryOrdinal = GET_LIBRARY_ORDINAL(symbol->n_desc);
1607 if ( !twoLevel || context.bindFlat )
1608 libraryOrdinal = BIND_SPECIAL_DYLIB_FLAT_LOOKUP;
1609 uintptr_t ptrToBind = (uintptr_t)lazyPointer;
1610 uintptr_t symbolAddr = bindAt(context, this, ptrToBind, BIND_TYPE_POINTER, symbolName, 0, 0, libraryOrdinal,
1611 NULL, "lazy ", patcher, NULL);
1612 ++fgTotalLazyBindFixups;
1613 return symbolAddr;
1614 }
1615 }
1616 }
1617 break;
1618 }
1619 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1620 }
1621 dyld::throwf("lazy pointer not found at address %p in image %s", lazyPointer, this->getPath());
1622 }
1623
1624
1625
1626 uintptr_t ImageLoaderMachOCompressed::doBindFastLazySymbol(uint32_t lazyBindingInfoOffset, const LinkContext& context,
1627 void (*lock)(), void (*unlock)())
1628 {
1629 // <rdar://problem/8663923> race condition with flat-namespace lazy binding
1630 if ( this->usesTwoLevelNameSpace() ) {
1631 // two-level namespace lookup does not require lock because dependents can't be unloaded before this image
1632 }
1633 else {
1634 // acquire dyld global lock
1635 if ( lock != NULL )
1636 lock();
1637 }
1638
1639 DyldSharedCache::DataConstLazyScopedWriter patcher(context.dyldCache, mach_task_self(), context.verboseMapping ? &dyld::log : nullptr);
1640
1641 const uint8_t* const start = fLinkEditBase + fDyldInfo->lazy_bind_off;
1642 const uint8_t* const end = &start[fDyldInfo->lazy_bind_size];
1643 uint8_t segIndex;
1644 uintptr_t segOffset;
1645 int libraryOrdinal;
1646 const char* symbolName;
1647 bool doneAfterBind;
1648 uintptr_t result;
1649 do {
1650 if ( ! getLazyBindingInfo(lazyBindingInfoOffset, start, end, &segIndex, &segOffset, &libraryOrdinal, &symbolName, &doneAfterBind) )
1651 dyld::throwf("bad lazy bind info");
1652
1653 if ( segIndex >= fSegmentsCount )
1654 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is too large (0..%d)",
1655 segIndex, fSegmentsCount-1);
1656 if ( segOffset > segSize(segIndex) )
1657 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has offset 0x%08lX beyond segment size (0x%08lX)", segOffset, segSize(segIndex));
1658 uintptr_t address = segActualLoadAddress(segIndex) + segOffset;
1659 result = bindAt(context, this, address, BIND_TYPE_POINTER, symbolName, 0, 0, libraryOrdinal,
1660 NULL, "lazy ", patcher, NULL, true);
1661 // <rdar://problem/24140465> Some old apps had multiple lazy symbols bound at once
1662 } while (!doneAfterBind && !context.strictMachORequired);
1663
1664 if ( !this->usesTwoLevelNameSpace() ) {
1665 // release dyld global lock
1666 if ( unlock != NULL )
1667 unlock();
1668 }
1669 return result;
1670 }
1671
1672 void ImageLoaderMachOCompressed::initializeCoalIterator(CoalIterator& it, unsigned int loadOrder, unsigned)
1673 {
1674 it.image = this;
1675 it.symbolName = " ";
1676 it.loadOrder = loadOrder;
1677 it.weakSymbol = false;
1678 it.symbolMatches = false;
1679 it.done = false;
1680 it.curIndex = 0;
1681 it.endIndex = (this->fDyldInfo ? this->fDyldInfo->weak_bind_size : 0);
1682 it.address = 0;
1683 it.type = 0;
1684 it.addend = 0;
1685 }
1686
1687
1688 bool ImageLoaderMachOCompressed::incrementCoalIterator(CoalIterator& it)
1689 {
1690 if ( it.done )
1691 return false;
1692
1693 if ( (this->fDyldInfo == nullptr) || (this->fDyldInfo->weak_bind_size == 0) ) {
1694 /// hmmm, ld set MH_WEAK_DEFINES or MH_BINDS_TO_WEAK, but there is no weak binding info
1695 it.done = true;
1696 it.symbolName = "~~~";
1697 return true;
1698 }
1699 const uint8_t* start = fLinkEditBase + fDyldInfo->weak_bind_off;
1700 const uint8_t* p = start + it.curIndex;
1701 const uint8_t* end = fLinkEditBase + fDyldInfo->weak_bind_off + this->fDyldInfo->weak_bind_size;
1702 uintptr_t count;
1703 uintptr_t skip;
1704 uintptr_t segOffset;
1705 while ( p < end ) {
1706 uint8_t immediate = *p & BIND_IMMEDIATE_MASK;
1707 uint8_t opcode = *p & BIND_OPCODE_MASK;
1708 ++p;
1709 switch (opcode) {
1710 case BIND_OPCODE_DONE:
1711 it.done = true;
1712 it.curIndex = p - start;
1713 it.symbolName = "~~~"; // sorts to end
1714 return true;
1715 case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
1716 it.symbolName = (char*)p;
1717 it.weakSymbol = ((immediate & BIND_SYMBOL_FLAGS_NON_WEAK_DEFINITION) == 0);
1718 it.symbolMatches = false;
1719 while (*p != '\0')
1720 ++p;
1721 ++p;
1722 it.curIndex = p - start;
1723 return false;
1724 case BIND_OPCODE_SET_TYPE_IMM:
1725 it.type = immediate;
1726 break;
1727 case BIND_OPCODE_SET_ADDEND_SLEB:
1728 it.addend = read_sleb128(p, end);
1729 break;
1730 case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
1731 if ( immediate >= fSegmentsCount )
1732 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is too large (0..%d)",
1733 immediate, fSegmentsCount-1);
1734 #if __arm__
1735 // <rdar://problem/23138428> iOS app compatibility
1736 if ( !segWriteable(immediate) && it.image->isPositionIndependentExecutable() )
1737 #elif TEXT_RELOC_SUPPORT
1738 // <rdar://problem/23479396&23590867> i386 OS X app compatibility
1739 if ( !segWriteable(immediate) && !segHasRebaseFixUps(immediate) && !segHasBindFixUps(immediate)
1740 && (!it.image->isExecutable() || it.image->isPositionIndependentExecutable()) )
1741 #else
1742 if ( !segWriteable(immediate) )
1743 #endif
1744 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB targets segment %s which is not writable", segName(immediate));
1745 segOffset = read_uleb128(p, end);
1746 if ( segOffset > segSize(immediate) )
1747 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has offset 0x%08lX beyond segment size (0x%08lX)", segOffset, segSize(immediate));
1748 it.address = segActualLoadAddress(immediate) + segOffset;
1749 break;
1750 case BIND_OPCODE_ADD_ADDR_ULEB:
1751 it.address += read_uleb128(p, end);
1752 break;
1753 case BIND_OPCODE_DO_BIND:
1754 it.address += sizeof(intptr_t);
1755 break;
1756 case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
1757 it.address += read_uleb128(p, end) + sizeof(intptr_t);
1758 break;
1759 case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
1760 it.address += immediate*sizeof(intptr_t) + sizeof(intptr_t);
1761 break;
1762 case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
1763 count = read_uleb128(p, end);
1764 skip = read_uleb128(p, end);
1765 for (uint32_t i=0; i < count; ++i) {
1766 it.address += skip + sizeof(intptr_t);
1767 }
1768 break;
1769 default:
1770 dyld::throwf("bad weak bind opcode '%d' found after processing %d bytes in '%s'", *p, (int)(p-start), this->getPath());
1771 }
1772 }
1773 /// hmmm, BIND_OPCODE_DONE is missing...
1774 it.done = true;
1775 it.symbolName = "~~~";
1776 //dyld::log("missing BIND_OPCODE_DONE for image %s\n", this->getPath());
1777 return true;
1778 }
1779
1780 uintptr_t ImageLoaderMachOCompressed::getAddressCoalIterator(CoalIterator& it, const LinkContext& context)
1781 {
1782 //dyld::log("looking for %s in %s\n", it.symbolName, this->getPath());
1783 const ImageLoader* foundIn = NULL;
1784 const ImageLoader::Symbol* sym = this->findShallowExportedSymbol(it.symbolName, &foundIn);
1785 if ( sym != NULL ) {
1786 //dyld::log("sym=%p, foundIn=%p\n", sym, foundIn);
1787 return foundIn->getExportedSymbolAddress(sym, context, this);
1788 }
1789 return 0;
1790 }
1791
1792
1793 void ImageLoaderMachOCompressed::updateUsesCoalIterator(CoalIterator& it, uintptr_t value, ImageLoader* targetImage, unsigned targetIndex, const LinkContext& context)
1794 {
1795 // <rdar://problem/6570879> weak binding done too early with inserted libraries
1796 if ( this->getState() < dyld_image_state_bound )
1797 return;
1798
1799 if ( fDyldInfo == nullptr )
1800 return;
1801
1802 const uint8_t* start = fLinkEditBase + fDyldInfo->weak_bind_off;
1803 const uint8_t* p = start + it.curIndex;
1804 const uint8_t* end = fLinkEditBase + fDyldInfo->weak_bind_off + this->fDyldInfo->weak_bind_size;
1805
1806 uint8_t type = it.type;
1807 uintptr_t address = it.address;
1808 const char* symbolName = it.symbolName;
1809 intptr_t addend = it.addend;
1810 uintptr_t count;
1811 uintptr_t skip;
1812 uintptr_t segOffset;
1813 bool done = false;
1814 bool boundSomething = false;
1815 while ( !done && (p < end) ) {
1816 uint8_t immediate = *p & BIND_IMMEDIATE_MASK;
1817 uint8_t opcode = *p & BIND_OPCODE_MASK;
1818 ++p;
1819 switch (opcode) {
1820 case BIND_OPCODE_DONE:
1821 done = true;
1822 break;
1823 case BIND_OPCODE_SET_SYMBOL_TRAILING_FLAGS_IMM:
1824 done = true;
1825 break;
1826 case BIND_OPCODE_SET_TYPE_IMM:
1827 type = immediate;
1828 break;
1829 case BIND_OPCODE_SET_ADDEND_SLEB:
1830 addend = read_sleb128(p, end);
1831 break;
1832 case BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB:
1833 if ( immediate >= fSegmentsCount )
1834 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has segment %d which is too large (0..%d)",
1835 immediate, fSegmentsCount-1);
1836 #if __arm__
1837 // <rdar://problem/23138428> iOS app compatibility
1838 if ( !segWriteable(immediate) && it.image->isPositionIndependentExecutable() )
1839 #elif TEXT_RELOC_SUPPORT
1840 // <rdar://problem/23479396&23590867> i386 OS X app compatibility
1841 if ( !segWriteable(immediate) && !segHasRebaseFixUps(immediate) && !segHasBindFixUps(immediate)
1842 && (!it.image->isExecutable() || it.image->isPositionIndependentExecutable()) )
1843 #else
1844 if ( !segWriteable(immediate) )
1845 #endif
1846 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB targets segment %s which is not writable", segName(immediate));
1847 segOffset = read_uleb128(p, end);
1848 if ( segOffset > segSize(immediate) )
1849 dyld::throwf("BIND_OPCODE_SET_SEGMENT_AND_OFFSET_ULEB has offset 0x%08lX beyond segment size (0x%08lX)", segOffset, segSize(immediate));
1850 address = segActualLoadAddress(immediate) + segOffset;
1851 break;
1852 case BIND_OPCODE_ADD_ADDR_ULEB:
1853 address += read_uleb128(p, end);
1854 break;
1855 case BIND_OPCODE_DO_BIND:
1856 bindLocation(context, this->imageBaseAddress(), address, value, type, symbolName, addend, this->getPath(), targetImage ? targetImage->getPath() : NULL, "weak ", NULL, fSlide);
1857 boundSomething = true;
1858 address += sizeof(intptr_t);
1859 break;
1860 case BIND_OPCODE_DO_BIND_ADD_ADDR_ULEB:
1861 bindLocation(context, this->imageBaseAddress(), address, value, type, symbolName, addend, this->getPath(), targetImage ? targetImage->getPath() : NULL, "weak ", NULL, fSlide);
1862 boundSomething = true;
1863 address += read_uleb128(p, end) + sizeof(intptr_t);
1864 break;
1865 case BIND_OPCODE_DO_BIND_ADD_ADDR_IMM_SCALED:
1866 bindLocation(context, this->imageBaseAddress(), address, value, type, symbolName, addend, this->getPath(), targetImage ? targetImage->getPath() : NULL, "weak ", NULL, fSlide);
1867 boundSomething = true;
1868 address += immediate*sizeof(intptr_t) + sizeof(intptr_t);
1869 break;
1870 case BIND_OPCODE_DO_BIND_ULEB_TIMES_SKIPPING_ULEB:
1871 count = read_uleb128(p, end);
1872 skip = read_uleb128(p, end);
1873 for (uint32_t i=0; i < count; ++i) {
1874 bindLocation(context, this->imageBaseAddress(), address, value, type, symbolName, addend, this->getPath(), targetImage ? targetImage->getPath() : NULL, "weak ", NULL, fSlide);
1875 boundSomething = true;
1876 address += skip + sizeof(intptr_t);
1877 }
1878 break;
1879 default:
1880 dyld::throwf("bad bind opcode %d in weak binding info", *p);
1881 }
1882 }
1883 // C++ weak coalescing cannot be tracked by reference counting. Error on side of never unloading.
1884 if ( boundSomething && (targetImage != this) )
1885 context.addDynamicReference(this, targetImage);
1886 }
1887
1888 uintptr_t ImageLoaderMachOCompressed::interposeAt(const LinkContext& context, ImageLoaderMachOCompressed* image,
1889 uintptr_t addr, uint8_t type, const char*,
1890 uint8_t, intptr_t, long,
1891 ExtraBindData *extraBindData,
1892 const char*, LastLookup*, bool runResolver)
1893 {
1894 if ( type == BIND_TYPE_POINTER ) {
1895 uintptr_t* fixupLocation = (uintptr_t*)addr;
1896 uintptr_t curValue = *fixupLocation;
1897 uintptr_t newValue = interposedAddress(context, curValue, image);
1898 if ( newValue != curValue) {
1899 *fixupLocation = newValue;
1900 }
1901 }
1902 return 0;
1903 }
1904
1905 void ImageLoaderMachOCompressed::doInterpose(const LinkContext& context)
1906 {
1907 if ( context.verboseInterposing )
1908 dyld::log("dyld: interposing %lu tuples onto image: %s\n", fgInterposingTuples.size(), this->getPath());
1909
1910 const dyld3::MachOAnalyzer* ma = (dyld3::MachOAnalyzer*)fMachOData;
1911 if ( !ma->hasChainedFixups() && (fDyldInfo != nullptr) ) {
1912 // Note: all binds that happen as part of normal loading and fixups will have interposing applied.
1913 // There is only two cases where we need to parse bind opcodes and apply interposing:
1914
1915 // make the cache writable for this block
1916 DyldSharedCache::DataConstLazyScopedWriter patcher(context.dyldCache, mach_task_self(), context.verboseMapping ? &dyld::log : nullptr);
1917 if ( ma->inDyldCache() )
1918 patcher.makeWriteable();
1919
1920 // 1) Lazy pointers are either not bound yet, or in dyld cache they are prebound (to uninterposed target)
1921 eachLazyBind(context, ^(const LinkContext& ctx, ImageLoaderMachOCompressed* image,
1922 uintptr_t addr, uint8_t type, const char* symbolName,
1923 uint8_t symbolFlags, intptr_t addend, long libraryOrdinal,
1924 ExtraBindData *extraBindData,
1925 const char* msg, LastLookup* last, bool runResolver) {
1926 return ImageLoaderMachOCompressed::interposeAt(ctx, image, addr, type, symbolName, symbolFlags,
1927 addend, libraryOrdinal, extraBindData,
1928 msg, last, runResolver);
1929 });
1930
1931 // 2) non-lazy pointers in the dyld cache need to be interposed
1932 if ( ma->inDyldCache() ) {
1933 eachBind(context, ^(const LinkContext& ctx, ImageLoaderMachOCompressed* image,
1934 uintptr_t addr, uint8_t type, const char* symbolName,
1935 uint8_t symbolFlags, intptr_t addend, long libraryOrdinal,
1936 ExtraBindData *extraBindData,
1937 const char* msg, LastLookup* last, bool runResolver) {
1938 return ImageLoaderMachOCompressed::interposeAt(ctx, image, addr, type, symbolName, symbolFlags,
1939 addend, libraryOrdinal, extraBindData,
1940 msg, last, runResolver);
1941 });
1942 }
1943
1944 }
1945 }
1946
1947
1948 uintptr_t ImageLoaderMachOCompressed::dynamicInterposeAt(const LinkContext& context, ImageLoaderMachOCompressed* image,
1949 uintptr_t addr, uint8_t type, const char* symbolName,
1950 uint8_t, intptr_t, long,
1951 ExtraBindData *extraBindData,
1952 const char*, LastLookup*, bool runResolver)
1953 {
1954 if ( type == BIND_TYPE_POINTER ) {
1955 uintptr_t* fixupLocation = (uintptr_t*)addr;
1956 uintptr_t value = *fixupLocation;
1957 // don't apply interposing to table entries.
1958 if ( (context.dynamicInterposeArray <= (void*)addr) && ((void*)addr < &context.dynamicInterposeArray[context.dynamicInterposeCount]) )
1959 return 0;
1960 for(size_t i=0; i < context.dynamicInterposeCount; ++i) {
1961 if ( value == (uintptr_t)context.dynamicInterposeArray[i].replacee ) {
1962 if ( context.verboseInterposing ) {
1963 dyld::log("dyld: dynamic interposing: at %p replace %p with %p in %s\n",
1964 fixupLocation, context.dynamicInterposeArray[i].replacee, context.dynamicInterposeArray[i].replacement, image->getPath());
1965 }
1966 *fixupLocation = (uintptr_t)context.dynamicInterposeArray[i].replacement;
1967 }
1968 }
1969 }
1970 return 0;
1971 }
1972
1973 void ImageLoaderMachOCompressed::dynamicInterpose(const LinkContext& context)
1974 {
1975 if ( context.verboseInterposing )
1976 dyld::log("dyld: dynamic interposing %lu tuples onto image: %s\n", context.dynamicInterposeCount, this->getPath());
1977
1978 // update already bound references to symbols
1979 eachBind(context, ^(const LinkContext& ctx, ImageLoaderMachOCompressed* image,
1980 uintptr_t addr, uint8_t type, const char* symbolName,
1981 uint8_t symbolFlags, intptr_t addend, long libraryOrdinal,
1982 ExtraBindData *extraBindData,
1983 const char* msg, LastLookup* last, bool runResolver) {
1984 return ImageLoaderMachOCompressed::dynamicInterposeAt(ctx, image, addr, type, symbolName, symbolFlags,
1985 addend, libraryOrdinal, extraBindData,
1986 msg, last, runResolver);
1987 });
1988 eachLazyBind(context, ^(const LinkContext& ctx, ImageLoaderMachOCompressed* image,
1989 uintptr_t addr, uint8_t type, const char* symbolName,
1990 uint8_t symbolFlags, intptr_t addend, long libraryOrdinal,
1991 ExtraBindData *extraBindData,
1992 const char* msg, LastLookup* last, bool runResolver) {
1993 return ImageLoaderMachOCompressed::dynamicInterposeAt(ctx, image, addr, type, symbolName, symbolFlags,
1994 addend, libraryOrdinal, extraBindData,
1995 msg, last, runResolver);
1996 });
1997 }
1998
1999 const char* ImageLoaderMachOCompressed::findClosestSymbol(const void* addr, const void** closestAddr) const
2000 {
2001 return ImageLoaderMachO::findClosestSymbol((mach_header*)fMachOData, addr, closestAddr);
2002 }
2003
2004
2005 #if PREBOUND_IMAGE_SUPPORT
2006 void ImageLoaderMachOCompressed::resetPreboundLazyPointers(const LinkContext& context)
2007 {
2008 // no way to back off a prebound compress image
2009 }
2010 #endif
2011
2012
2013 #if __arm__ || __x86_64__
2014 void ImageLoaderMachOCompressed::updateAlternateLazyPointer(uint8_t* stub, void** originalLazyPointerAddr, const LinkContext& context)
2015 {
2016 #if __arm__
2017 uint32_t* instructions = (uint32_t*)stub;
2018 // sanity check this is a stub we understand
2019 if ( (instructions[0] != 0xe59fc004) || (instructions[1] != 0xe08fc00c) || (instructions[2] != 0xe59cf000) )
2020 return;
2021
2022 void** lazyPointerAddr = (void**)(instructions[3] + (stub + 12));
2023 #endif
2024 #if __x86_64__
2025 // sanity check this is a stub we understand
2026 if ( (stub[0] != 0xFF) || (stub[1] != 0x25) )
2027 return;
2028 int32_t ripOffset = *((int32_t*)(&stub[2]));
2029 void** lazyPointerAddr = (void**)(ripOffset + stub + 6);
2030 #endif
2031
2032 // if stub does not use original lazy pointer (meaning it was optimized by update_dyld_shared_cache)
2033 if ( lazyPointerAddr != originalLazyPointerAddr ) {
2034 // <rdar://problem/12928448> only de-optimization lazy pointers if they are part of shared cache not loaded (because overridden)
2035 const ImageLoader* lazyPointerImage = context.findImageContainingAddress(lazyPointerAddr);
2036 if ( lazyPointerImage != NULL )
2037 return;
2038
2039 // copy newly re-bound lazy pointer value to shared lazy pointer
2040 *lazyPointerAddr = *originalLazyPointerAddr;
2041
2042 if ( context.verboseBind )
2043 dyld::log("dyld: alter bind: %s: *0x%08lX = 0x%08lX \n",
2044 this->getShortName(), (long)lazyPointerAddr, (long)*originalLazyPointerAddr);
2045 }
2046 }
2047 #endif
2048
2049
2050 // <rdar://problem/8890875> overriding shared cache dylibs with resolvers fails
2051 void ImageLoaderMachOCompressed::updateOptimizedLazyPointers(const LinkContext& context)
2052 {
2053 #if __arm__ || __x86_64__
2054 // find stubs and indirect symbol table
2055 const struct macho_section* stubsSection = NULL;
2056 const dysymtab_command* dynSymbolTable = NULL;
2057 const macho_header* mh = (macho_header*)fMachOData;
2058 const uint32_t cmd_count = mh->ncmds;
2059 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
2060 const struct load_command* cmd = cmds;
2061 for (uint32_t i = 0; i < cmd_count; ++i) {
2062 if (cmd->cmd == LC_SEGMENT_COMMAND) {
2063 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
2064 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
2065 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
2066 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
2067 const uint8_t type = sect->flags & SECTION_TYPE;
2068 if ( type == S_SYMBOL_STUBS )
2069 stubsSection = sect;
2070 }
2071 }
2072 else if ( cmd->cmd == LC_DYSYMTAB ) {
2073 dynSymbolTable = (struct dysymtab_command*)cmd;
2074 }
2075 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
2076 }
2077 if ( dynSymbolTable == NULL )
2078 return;
2079 const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[dynSymbolTable->indirectsymoff];
2080 if ( stubsSection == NULL )
2081 return;
2082 const uint32_t stubsSize = stubsSection->reserved2;
2083 const uint32_t stubsCount = (uint32_t)(stubsSection->size / stubsSize);
2084 const uint32_t stubsIndirectTableOffset = stubsSection->reserved1;
2085 if ( (stubsIndirectTableOffset+stubsCount) > dynSymbolTable->nindirectsyms )
2086 return;
2087 uint8_t* const stubsAddr = (uint8_t*)(stubsSection->addr + this->fSlide);
2088
2089 // for each lazy pointer section
2090 cmd = cmds;
2091 for (uint32_t i = 0; i < cmd_count; ++i) {
2092 if (cmd->cmd == LC_SEGMENT_COMMAND) {
2093 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
2094 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
2095 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
2096 for (const struct macho_section* lazyPointerSection=sectionsStart; lazyPointerSection < sectionsEnd; ++lazyPointerSection) {
2097 const uint8_t type = lazyPointerSection->flags & SECTION_TYPE;
2098 if ( type != S_LAZY_SYMBOL_POINTERS )
2099 continue;
2100 const uint32_t lazyPointersCount = (uint32_t)(lazyPointerSection->size / sizeof(void*));
2101 const uint32_t lazyPointersIndirectTableOffset = lazyPointerSection->reserved1;
2102 if ( (lazyPointersIndirectTableOffset+lazyPointersCount) > dynSymbolTable->nindirectsyms )
2103 continue;
2104 void** const lazyPointersAddr = (void**)(lazyPointerSection->addr + this->fSlide);
2105 // for each lazy pointer
2106 for(uint32_t lpIndex=0; lpIndex < lazyPointersCount; ++lpIndex) {
2107 const uint32_t lpSymbolIndex = indirectTable[lazyPointersIndirectTableOffset+lpIndex];
2108 // find matching stub and validate it uses this lazy pointer
2109 for(uint32_t stubIndex=0; stubIndex < stubsCount; ++stubIndex) {
2110 if ( indirectTable[stubsIndirectTableOffset+stubIndex] == lpSymbolIndex ) {
2111 this->updateAlternateLazyPointer(stubsAddr+stubIndex*stubsSize, &lazyPointersAddr[lpIndex], context);
2112 break;
2113 }
2114 }
2115 }
2116
2117 }
2118 }
2119 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
2120 }
2121
2122 #endif
2123 }
2124
2125
2126 void ImageLoaderMachOCompressed::registerEncryption(const encryption_info_command* encryptCmd, const LinkContext& context)
2127 {
2128 #if (__arm__ || __arm64__) && !TARGET_OS_SIMULATOR
2129 if ( encryptCmd == NULL )
2130 return;
2131 // fMachOData not set up yet, need to manually find mach_header
2132 const mach_header* mh = NULL;
2133 for(unsigned int i=0; i < fSegmentsCount; ++i) {
2134 if ( (segFileOffset(i) == 0) && (segFileSize(i) != 0) ) {
2135 mh = (mach_header*)segActualLoadAddress(i);
2136 void* start = ((uint8_t*)mh) + encryptCmd->cryptoff;
2137 size_t len = encryptCmd->cryptsize;
2138 uint32_t cputype = mh->cputype;
2139 uint32_t cpusubtype = mh->cpusubtype;
2140 uint32_t cryptid = encryptCmd->cryptid;
2141 if (context.verboseMapping) {
2142 dyld::log(" 0x%08lX->0x%08lX configured for FairPlay decryption\n", (long)start, (long)start+len);
2143 }
2144 int result = mremap_encrypted(start, len, cryptid, cputype, cpusubtype);
2145 if ( result != 0 ) {
2146 dyld::throwf("mremap_encrypted() => %d, errno=%d for %s\n", result, errno, this->getPath());
2147 }
2148 return;
2149 }
2150 }
2151 #endif
2152 }
2153
2154
2155
mirror of dyld