dyld-45.1.tar.gz
[apple/dyld.git] / src / ImageLoaderMachO.cpp
1 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
2 *
3 * Copyright (c) 2004-2005 Apple Computer, 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.
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22 * @APPLE_LICENSE_HEADER_END@
23 */
24
25 #include <string.h>
26 #include <fcntl.h>
27 #include <sys/types.h>
28 #include <sys/stat.h>
29 #include <sys/mman.h>
30 #include <mach/shared_memory_server.h>
31 #include <mach/mach.h>
32 #include <mach/thread_status.h>
33 #include <mach-o/loader.h>
34 #include <mach-o/reloc.h>
35 #include <mach-o/nlist.h>
36 #include <sys/sysctl.h>
37 #if __ppc__ || __ppc64__
38 #include <mach-o/ppc/reloc.h>
39 #endif
40
41 #ifndef S_ATTR_SELF_MODIFYING_CODE
42 #define S_ATTR_SELF_MODIFYING_CODE 0x04000000
43 #endif
44
45 #include "ImageLoaderMachO.h"
46 #include "mach-o/dyld_gdb.h"
47
48 // no header for this yet, rdar://problem/3850825
49 extern "C" void sys_icache_invalidate(void *, size_t);
50
51 // optimize strcmp for ppc
52 #if __ppc__
53 #include <ppc_intrinsics.h>
54 #else
55 #define astrcmp(a,b) strcmp(a,b)
56 #endif
57
58 // relocation_info.r_length field has value 3 for 64-bit executables and value 2 for 32-bit executables
59 #if __LP64__
60 #define RELOC_SIZE 3
61 #define LC_SEGMENT_COMMAND LC_SEGMENT_64
62 #define LC_ROUTINES_COMMAND LC_ROUTINES_64
63 struct macho_header : public mach_header_64 {};
64 struct macho_segment_command : public segment_command_64 {};
65 struct macho_section : public section_64 {};
66 struct macho_nlist : public nlist_64 {};
67 struct macho_routines_command : public routines_command_64 {};
68 #else
69 #define RELOC_SIZE 2
70 #define LC_SEGMENT_COMMAND LC_SEGMENT
71 #define LC_ROUTINES_COMMAND LC_ROUTINES
72 struct macho_header : public mach_header {};
73 struct macho_segment_command : public segment_command {};
74 struct macho_section : public section {};
75 struct macho_nlist : public nlist {};
76 struct macho_routines_command : public routines_command {};
77 #endif
78
79 #define POINTER_RELOC GENERIC_RELOC_VANILLA
80
81 uint32_t ImageLoaderMachO::fgHintedBinaryTreeSearchs = 0;
82 uint32_t ImageLoaderMachO::fgUnhintedBinaryTreeSearchs = 0;
83 uint32_t ImageLoaderMachO::fgCountOfImagesWithWeakExports = 0;
84
85
86 //#define LINKEDIT_USAGE_DEBUG 1
87
88 #if LINKEDIT_USAGE_DEBUG
89 #include <set>
90 static std::set<uintptr_t> sLinkEditPageBuckets;
91
92 namespace dyld {
93 extern ImageLoader* findImageContainingAddress(const void* addr);
94 };
95
96 static void noteAccessedLinkEditAddress(const void* addr)
97 {
98 uintptr_t page = ((uintptr_t)addr) & (-4096);
99 sLinkEditPageBuckets.insert(page);
100 fprintf(stderr, "dyld: accessing page 0x%08lX in __LINKEDIT of %s\n", page, dyld::findImageContainingAddress(addr)->getPath());
101 }
102 #endif
103
104 // only way to share initialization in C++
105 void ImageLoaderMachO::init()
106 {
107 fMachOData = NULL;
108 fLinkEditBase = NULL;
109 fSymbolTable = NULL;
110 fStrings = NULL;
111 fDynamicInfo = NULL;
112 fSlide = 0;
113 fIsSplitSeg = false;
114 fHasSubLibraries= false;
115 fHasSubUmbrella = false;
116 fDashInit = NULL;
117 fModInitSection = NULL;
118 fModTermSection = NULL;
119 fDATAdyld = NULL;
120 fImageNotifySection = NULL;
121 fTwoLevelHints = NULL;
122 fDylibID = NULL;
123 fReExportThruFramework = NULL;
124 fTextSegmentWithFixups = NULL;
125 }
126
127 // create image by copying an in-memory mach-o file
128 ImageLoaderMachO::ImageLoaderMachO(const char* moduleName, const struct mach_header* mh, uint64_t len, const LinkContext& context)
129 : ImageLoader(moduleName)
130 {
131 // clean slate
132 this->init();
133
134 // temporary use this buffer until TEXT is mapped in
135 fMachOData = (const uint8_t*)mh;
136
137 // create segments
138 this->instantiateSegments((const uint8_t*)mh);
139
140 // map segments
141 if ( mh->filetype != MH_EXECUTE )
142 ImageLoader::mapSegments((const void*)mh, len, context);
143
144 // get pointers to interesting things
145 this->parseLoadCmds();
146 }
147
148
149 // create image by mapping in a mach-o file
150 ImageLoaderMachO::ImageLoaderMachO(const char* path, int fd, const uint8_t firstPage[4096], uint64_t offsetInFat,
151 uint64_t lenInFat, const struct stat& info, const LinkContext& context)
152 : ImageLoader(path, offsetInFat, info)
153 {
154 // clean slate
155 this->init();
156
157 // read load commands
158 const unsigned int dataSize = sizeof(macho_header) + ((macho_header*)firstPage)->sizeofcmds;
159 uint8_t buffer[dataSize];
160 const uint8_t* fileData = firstPage;
161 if ( dataSize > 4096 ) {
162 // only read more if cmds take up more space than first page
163 fileData = buffer;
164 memcpy(buffer, firstPage, 4096);
165 pread(fd, &buffer[4096], dataSize-4096, offsetInFat+4096);
166 }
167
168 // temporary use this buffer until TEXT is mapped in
169 fMachOData = fileData;
170
171 // the meaning of many fields changes in split seg mach-o files
172 fIsSplitSeg = ((((macho_header*)fileData)->flags & MH_SPLIT_SEGS) != 0) && (((macho_header*)fileData)->filetype == MH_DYLIB);
173
174 // create segments
175 this->instantiateSegments(fileData);
176
177 // map segments, except for main executable which is already mapped in by kernel
178 if ( ((macho_header*)fileData)->filetype != MH_EXECUTE )
179 this->mapSegments(fd, offsetInFat, lenInFat, info.st_size, context);
180
181 // get pointers to interesting things
182 this->parseLoadCmds();
183 }
184
185 ImageLoaderMachO::~ImageLoaderMachO()
186 {
187 // keep count of images with weak exports
188 if ( this->hasCoalescedExports() )
189 --fgCountOfImagesWithWeakExports;
190 }
191
192
193
194 void ImageLoaderMachO::instantiateSegments(const uint8_t* fileData)
195 {
196 const uint32_t cmd_count = ((macho_header*)fileData)->ncmds;
197 const struct load_command* const cmds = (struct load_command*)&fileData[sizeof(macho_header)];
198
199 // construct Segment object for each LC_SEGMENT cmd and add to list
200 const struct load_command* cmd = cmds;
201 for (unsigned long i = 0; i < cmd_count; ++i) {
202 if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
203 if ( (((struct macho_segment_command*)cmd)->vmsize != 0) || !fIsSplitSeg )
204 fSegments.push_back(new SegmentMachO((struct macho_segment_command*)cmd, this, fileData));
205 }
206 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
207 }
208 }
209
210
211
212 bool ImageLoaderMachO::segmentsMustSlideTogether() const
213 {
214 return true;
215 }
216
217 bool ImageLoaderMachO::segmentsCanSlide() const
218 {
219 const macho_header* mh = (macho_header*)fMachOData;
220 return ( (mh->filetype == MH_DYLIB) || (mh->filetype == MH_BUNDLE) );
221 }
222
223 bool ImageLoaderMachO::isBundle() const
224 {
225 const macho_header* mh = (macho_header*)fMachOData;
226 return ( mh->filetype == MH_BUNDLE );
227 }
228
229 bool ImageLoaderMachO::isDylib() const
230 {
231 const macho_header* mh = (macho_header*)fMachOData;
232 return ( mh->filetype == MH_DYLIB );
233 }
234
235 bool ImageLoaderMachO::forceFlat() const
236 {
237 const macho_header* mh = (macho_header*)fMachOData;
238 return ( (mh->flags & MH_FORCE_FLAT) != 0 );
239 }
240
241 bool ImageLoaderMachO::usesTwoLevelNameSpace() const
242 {
243 const macho_header* mh = (macho_header*)fMachOData;
244 return ( (mh->flags & MH_TWOLEVEL) != 0 );
245 }
246
247 bool ImageLoaderMachO::isPrebindable() const
248 {
249 const macho_header* mh = (macho_header*)fMachOData;
250 return ( (mh->flags & MH_PREBOUND) != 0 );
251 }
252
253 bool ImageLoaderMachO::hasCoalescedExports() const
254 {
255 const macho_header* mh = (macho_header*)fMachOData;
256 return ( (mh->flags & MH_WEAK_DEFINES) != 0 );
257 }
258
259 bool ImageLoaderMachO::needsCoalescing() const
260 {
261 const macho_header* mh = (macho_header*)fMachOData;
262 return ( (mh->flags & MH_BINDS_TO_WEAK) != 0 );
263 }
264
265 #if !__LP64__ // split segs not supported for 64-bits
266
267 #if 1 // hack until kernel headers and glue are in system
268 struct _shared_region_mapping_np {
269 mach_vm_address_t address;
270 mach_vm_size_t size;
271 mach_vm_offset_t file_offset;
272 vm_prot_t max_prot; /* read/write/execute/COW/ZF */
273 vm_prot_t init_prot; /* read/write/execute/COW/ZF */
274 };
275 struct _shared_region_range_np {
276 mach_vm_address_t address;
277 mach_vm_size_t size;
278 };
279
280 // Called by dyld.
281 // Requests the kernel to map a number of regions from the fd into the
282 // shared sections address range (0x90000000-0xAFFFFFFF).
283 // If shared_region_make_private_np() has not been called by this process,
284 // the file mapped in is seen in the address space of all processes that
285 // participate in using the shared region.
286 // If shared_region_make_private_np() _has_ been called by this process,
287 // the file mapped in is only seen by this process.
288 // If the slide parameter is not NULL and then regions cannot be mapped
289 // as requested, the kernel will try to map the file in at a different
290 // address in the shared region and return the distance slid.
291 // If the mapping requesting cannot be fulfilled, returns non-zero.
292 static int
293 _shared_region_map_file_np(
294 int fd, // file descriptor to map into shared region
295 unsigned int regionCount, // number of entres in array of regions
296 const _shared_region_mapping_np regions[], // the array of regions to map
297 uint64_t* slide) // the amount all regions were slid, NULL means don't attempt to slide
298 {
299 //fprintf(stderr, "%s(%i, %u, %8p, %8p)\n", __func__, fd, regionCount, regions, slide);
300 //for ( unsigned int i=0; i < regionCount; ++i) {
301 // fprintf(stderr, "\taddress=0x%08llX, size=0x%08llX\n", regions[i].address, regions[i].size);
302 //}
303 int r = syscall(299, fd, regionCount, regions, slide);
304 // if(0 != r)
305 // fprintf(stderr, "%s(%i, %u, %8p, %8p) errno=%i (%s)\n", __func__, fd, regionCount, regions, slide, errno, strerror(errno));
306 return r;
307 }
308 // Called by dyld if shared_region_map_file() fails.
309 // Requests the kernel to take this process out of using the shared region.
310 // The specified ranges are created as private copies from the shared region for this process.
311 static int
312 _shared_region_make_private_np(
313 unsigned int rangeCount, // number of entres in array of msrp_range
314 const _shared_region_range_np ranges[]) // the array of shared regions to make private
315 {
316 //fprintf(stderr, "%s(%u, %8p)\n", __func__, rangeCount, ranges);
317 int r = syscall(300, rangeCount, ranges);
318 // if(0 != r)
319 // fprintf(stderr, "%s(%u, %8p) errno=%i (%s)\n", __func__, rangeCount, ranges, errno, strerror(errno));
320 return r;
321 }
322 #define KERN_SHREG_PRIVATIZABLE 54
323 #endif // hack until kernel headers and glue are in system
324
325 static uintptr_t sNextAltLoadAddress
326 #if __ppc_
327 = 0xC0000000;
328 #else
329 = 0;
330 #endif
331
332 static int
333 _shared_region_map_file_with_mmap(
334 int fd, // file descriptor to map into shared region
335 unsigned int regionCount, // number of entres in array of regions
336 const _shared_region_mapping_np regions[]) // the array of regions to map
337 {
338 // map in each region
339 for(unsigned int i=0; i < regionCount; ++i) {
340 void* mmapAddress = (void*)(uintptr_t)(regions[i].address);
341 size_t size = regions[i].size;
342 if ( (regions[i].init_prot & VM_PROT_ZF) != 0 ) {
343 // do nothing already vm_allocate() which zero fills
344 }
345 else {
346 int protection = 0;
347 if ( regions[i].init_prot & VM_PROT_EXECUTE )
348 protection |= PROT_EXEC;
349 if ( regions[i].init_prot & VM_PROT_READ )
350 protection |= PROT_READ;
351 if ( regions[i].init_prot & VM_PROT_WRITE )
352 protection |= PROT_WRITE;
353 off_t offset = regions[i].file_offset;
354 //fprintf(stderr, "mmap(%p, 0x%08lX, block=0x%08X, %s\n", mmapAddress, size, biggestDiff, fPath);
355 mmapAddress = mmap(mmapAddress, size, protection, MAP_FILE | MAP_FIXED | MAP_PRIVATE, fd, offset);
356 if ( mmapAddress == ((void*)(-1)) )
357 throw "mmap error";
358 }
359 }
360
361 return 0;
362 }
363
364
365 static
366 bool
367 hasSharedRegionMapFile(void)
368 {
369 int mib[CTL_MAXNAME];
370 int value = 0;
371 size_t size;
372
373 mib[0] = CTL_KERN;
374 mib[1] = KERN_SHREG_PRIVATIZABLE;
375 size = sizeof (int);
376 if (sysctl(mib, 2, &value, &size, NULL, 0) != 0) {
377 value = 0;
378 }
379
380 return 0 != value;
381 }
382
383 int
384 ImageLoaderMachO::sharedRegionMapFilePrivateOutside(int fd,
385 uint64_t offsetInFat,
386 uint64_t lenInFat,
387 uint64_t fileLen,
388 const LinkContext& context)
389 {
390 const unsigned int segmentCount = fSegments.size();
391 const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
392 const unsigned int regionCount = segmentCount+extraZeroFillEntries;
393 _shared_region_mapping_np regions[regionCount];
394 initMappingTable(offsetInFat, regions);
395 int r = -1;
396 // find space somewhere to allocate split seg
397 bool foundRoom = false;
398 vm_size_t biggestDiff = 0;
399 while ( ! foundRoom ) {
400 foundRoom = true;
401 for(unsigned int i=0; i < regionCount; ++i) {
402 vm_address_t addr = sNextAltLoadAddress + regions[i].address - regions[0].address;
403 vm_size_t size = regions[i].size ;
404 r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
405 if ( 0 != r ) {
406 // no room here, deallocate what has succeeded so far
407 for(unsigned int j=0; j < i; ++j) {
408 vm_address_t addr = sNextAltLoadAddress + regions[j].address - regions[0].address;
409 vm_size_t size = regions[j].size ;
410 (void)vm_deallocate(mach_task_self(), addr, size);
411 }
412 sNextAltLoadAddress += 0x00100000; // skip ahead 1MB and try again
413 if ( (sNextAltLoadAddress & 0xF0000000) == 0x90000000 )
414 sNextAltLoadAddress = 0xB0000000;
415 if ( (sNextAltLoadAddress & 0xF0000000) == 0xF0000000 )
416 throw "can't map split seg anywhere";
417 foundRoom = false;
418 break;
419 }
420 vm_size_t high = (regions[i].address + size - regions[0].address) & 0x0FFFFFFF;
421 if ( high > biggestDiff )
422 biggestDiff = high;
423 }
424 }
425
426 // map in each region
427 uintptr_t slide = sNextAltLoadAddress - regions[0].address;
428 this->setSlide(slide);
429 for(unsigned int i=0; i < regionCount; ++i) {
430 if ( (regions[i].init_prot & VM_PROT_ZF) != 0 ) {
431 // do nothing vm_allocate() zero-fills by default
432 }
433 else {
434 void* mmapAddress = (void*)(uintptr_t)(regions[i].address + slide);
435 size_t size = regions[i].size;
436 int protection = 0;
437 if ( regions[i].init_prot & VM_PROT_EXECUTE )
438 protection |= PROT_EXEC;
439 if ( regions[i].init_prot & VM_PROT_READ )
440 protection |= PROT_READ;
441 if ( regions[i].init_prot & VM_PROT_WRITE )
442 protection |= PROT_WRITE;
443 off_t offset = regions[i].file_offset;
444 //fprintf(stderr, "mmap(%p, 0x%08lX, block=0x%08X, %s\n", mmapAddress, size, biggestDiff, fPath);
445 mmapAddress = mmap(mmapAddress, size, protection, MAP_FILE | MAP_FIXED | MAP_PRIVATE, fd, offset);
446 if ( mmapAddress == ((void*)(-1)) )
447 throw "mmap error";
448 }
449 }
450 // set so next maps right after this one
451 sNextAltLoadAddress += biggestDiff;
452 sNextAltLoadAddress = (sNextAltLoadAddress + 4095) & (-4096);
453
454 // logging
455 if ( context.verboseMapping ) {
456 fprintf(stderr, "dyld: Mapping split-seg outside shared region, slid by 0x%08lX %s\n", this->fSlide, this->getPath());
457 for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
458 Segment* seg = fSegments[segIndex];
459 const _shared_region_mapping_np* entry = &regions[entryIndex];
460 if ( (entry->init_prot & VM_PROT_ZF) == 0 )
461 fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
462 seg->getName(), seg->getActualLoadAddress(), seg->getActualLoadAddress()+seg->getFileSize()-1);
463 if ( entryIndex < (regionCount-1) ) {
464 const _shared_region_mapping_np* nextEntry = &regions[entryIndex+1];
465 if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
466 uint64_t segOffset = nextEntry->address - entry->address;
467 fprintf(stderr, "%18s at 0x%08lX->0x%08lX (zerofill)\n",
468 seg->getName(), (uintptr_t)(seg->getActualLoadAddress() + segOffset), (uintptr_t)(seg->getActualLoadAddress() + segOffset + nextEntry->size - 1));
469 ++entryIndex;
470 }
471 }
472 }
473 }
474
475 return r;
476 }
477
478
479 void ImageLoaderMachO::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
480 {
481 enum SharedRegionState
482 {
483 kSharedRegionStartState = 0,
484 kSharedRegionLoadFileState,
485 kSharedRegionMapFileState,
486 kSharedRegionMapFilePrivateState,
487 kSharedRegionMapFilePrivateMMapState,
488 kSharedRegionMapFilePrivateOutsideState,
489 };
490 static SharedRegionState sSharedRegionState = kSharedRegionStartState;
491
492 // non-split segment libraries handled by super class
493 if ( !fIsSplitSeg )
494 return ImageLoader::mapSegments(fd, offsetInFat, lenInFat, fileLen, context);
495
496 if ( kSharedRegionStartState == sSharedRegionState ) {
497 if ( hasSharedRegionMapFile() ) {
498 if ( context.slideAndPackDylibs ) {
499 sharedRegionMakePrivate(context);
500 // remove underlying submap and block out 0x90000000 to 0xAFFFFFFF
501 vm_address_t addr = (vm_address_t)0x90000000;
502 vm_deallocate(mach_task_self(), addr, 0x20000000);
503 vm_allocate(mach_task_self(), &addr, 0x20000000, false);
504 sSharedRegionState = kSharedRegionMapFilePrivateMMapState;
505 }
506 else if ( context.sharedRegionMode == kUsePrivateSharedRegion ) {
507 sharedRegionMakePrivate(context);
508 sSharedRegionState = kSharedRegionMapFilePrivateState;
509 }
510 else if ( context.sharedRegionMode == kDontUseSharedRegion ) {
511 sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
512 }
513 else {
514 sSharedRegionState = kSharedRegionMapFileState;
515 }
516 }
517 else {
518 sSharedRegionState = kSharedRegionLoadFileState;
519 }
520 }
521
522 if ( kSharedRegionLoadFileState == sSharedRegionState ) {
523 if ( 0 != sharedRegionLoadFile(fd, offsetInFat, lenInFat, fileLen, context) ) {
524 sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
525 }
526 }
527 else
528 if ( kSharedRegionMapFileState == sSharedRegionState ) {
529 if ( 0 != sharedRegionMapFile(fd, offsetInFat, lenInFat, fileLen, context) ) {
530 sharedRegionMakePrivate(context);
531 sSharedRegionState = kSharedRegionMapFilePrivateState;
532 }
533 }
534
535 if ( (kSharedRegionMapFilePrivateState == sSharedRegionState) || (kSharedRegionMapFilePrivateMMapState == sSharedRegionState) ) {
536 if ( 0 != sharedRegionMapFilePrivate(fd, offsetInFat, lenInFat, fileLen, context, (kSharedRegionMapFilePrivateMMapState == sSharedRegionState)) ) {
537 sSharedRegionState = kSharedRegionMapFilePrivateOutsideState;
538 }
539 }
540
541 if ( kSharedRegionMapFilePrivateOutsideState == sSharedRegionState ) {
542 if ( 0 != sharedRegionMapFilePrivateOutside(fd, offsetInFat, lenInFat, fileLen, context) ) {
543 throw "mapping error";
544 }
545 }
546 }
547
548 unsigned int
549 ImageLoaderMachO::getExtraZeroFillEntriesCount()
550 {
551 // calculate mapping entries
552 const unsigned int segmentCount = fSegments.size();
553 unsigned int extraZeroFillEntries = 0;
554 for(unsigned int i=0; i < segmentCount; ++i){
555 Segment* seg = fSegments[i];
556 if ( seg->hasTrailingZeroFill() )
557 ++extraZeroFillEntries;
558 }
559
560 return extraZeroFillEntries;
561 }
562
563 void
564 ImageLoaderMachO::initMappingTable(uint64_t offsetInFat,
565 _shared_region_mapping_np *mappingTable)
566 {
567 unsigned int segmentCount = fSegments.size();
568 for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
569 Segment* seg = fSegments[segIndex];
570 _shared_region_mapping_np* entry = &mappingTable[entryIndex];
571 entry->address = seg->getActualLoadAddress();
572 entry->size = seg->getFileSize();
573 entry->file_offset = seg->getFileOffset() + offsetInFat;
574 entry->init_prot = VM_PROT_NONE;
575 if ( !seg->unaccessible() ) {
576 if ( seg->executable() )
577 entry->init_prot |= VM_PROT_EXECUTE;
578 if ( seg->readable() )
579 entry->init_prot |= VM_PROT_READ;
580 if ( seg->writeable() )
581 entry->init_prot |= VM_PROT_WRITE | VM_PROT_COW;
582 }
583 entry->max_prot = entry->init_prot;
584 if ( seg->hasTrailingZeroFill() ) {
585 _shared_region_mapping_np* zfentry = &mappingTable[++entryIndex];
586 zfentry->address = entry->address + seg->getFileSize();
587 zfentry->size = seg->getSize() - seg->getFileSize();
588 zfentry->file_offset = 0;
589 zfentry->init_prot = entry->init_prot | VM_PROT_COW | VM_PROT_ZF;
590 zfentry->max_prot = zfentry->init_prot;
591 }
592 }
593 }
594
595 int
596 ImageLoaderMachO::sharedRegionMakePrivate(const LinkContext& context)
597 {
598 if ( context.verboseMapping )
599 fprintf(stderr, "dyld: making shared regions private\n");
600
601 // shared mapping failed, so make private copy of shared region and try mapping private
602 RegionsVector allRegions;
603 context.getAllMappedRegions(allRegions);
604 std::vector<_shared_region_range_np> splitSegRegions;
605 const unsigned int allRegiontCount = allRegions.size();
606 for(unsigned int i=0; i < allRegiontCount; ++i){
607 MappedRegion region = allRegions[i];
608 uint8_t highByte = region.address >> 28;
609 if ( (highByte == 9) || (highByte == 0xA) ) {
610 _shared_region_range_np splitRegion;
611 splitRegion.address = region.address;
612 splitRegion.size = region.size;
613 splitSegRegions.push_back(splitRegion);
614 }
615 }
616 int result = _shared_region_make_private_np(splitSegRegions.size(), &splitSegRegions[0]);
617 // notify gdb or other lurkers that this process is no longer using the shared region
618 dyld_all_image_infos.processDetachedFromSharedRegion = true;
619 return result;
620 }
621
622 int
623 ImageLoaderMachO::sharedRegionMapFile(int fd,
624 uint64_t offsetInFat,
625 uint64_t lenInFat,
626 uint64_t fileLen,
627 const LinkContext& context)
628 {
629 // build table of segments to map
630 const unsigned int segmentCount = fSegments.size();
631 const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
632 const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
633 _shared_region_mapping_np mappingTable[mappingTableCount];
634 initMappingTable(offsetInFat, mappingTable);
635 // uint64_t slide;
636 uint64_t *slidep = NULL;
637
638 // try to map it in shared
639 int r = _shared_region_map_file_np(fd, mappingTableCount, mappingTable, slidep);
640 if ( 0 == r ) {
641 if(NULL != slidep && 0 != *slidep) {
642 // update with actual load addresses
643 }
644 if ( context.verboseMapping ) {
645 fprintf(stderr, "dyld: Mapping split-seg shared %s\n", this->getPath());
646 for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
647 Segment* seg = fSegments[segIndex];
648 const _shared_region_mapping_np* entry = &mappingTable[entryIndex];
649 if ( (entry->init_prot & VM_PROT_ZF) == 0 )
650 fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
651 seg->getName(), seg->getActualLoadAddress(), seg->getActualLoadAddress()+seg->getFileSize()-1);
652 if ( entryIndex < (mappingTableCount-1) ) {
653 const _shared_region_mapping_np* nextEntry = &mappingTable[entryIndex+1];
654 if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
655 uint64_t segOffset = nextEntry->address - entry->address;
656 fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
657 seg->getName(), (uintptr_t)(seg->getActualLoadAddress() + segOffset), (uintptr_t)(seg->getActualLoadAddress() + segOffset + nextEntry->size - 1));
658 ++entryIndex;
659 }
660 }
661 }
662 }
663 }
664 return r;
665 }
666
667
668 int
669 ImageLoaderMachO::sharedRegionMapFilePrivate(int fd,
670 uint64_t offsetInFat,
671 uint64_t lenInFat,
672 uint64_t fileLen,
673 const LinkContext& context,
674 bool usemmap)
675 {
676 const unsigned int segmentCount = fSegments.size();
677
678 // adjust base address of segments to pack next to last dylib
679 if ( context.slideAndPackDylibs ) {
680 uintptr_t lowestReadOnly = (uintptr_t)(-1);
681 uintptr_t lowestWritable = (uintptr_t)(-1);
682 for(unsigned int segIndex=0; segIndex < segmentCount; ++segIndex){
683 Segment* seg = fSegments[segIndex];
684 uintptr_t segEnd = seg->getActualLoadAddress();
685 if ( seg->writeable() ) {
686 if ( segEnd < lowestWritable )
687 lowestWritable = segEnd;
688 }
689 else {
690 if ( segEnd < lowestReadOnly )
691 lowestReadOnly = segEnd;
692 }
693 }
694 uintptr_t baseAddress;
695 if ( lowestWritable - 256*1024*1024 < lowestReadOnly )
696 baseAddress = lowestWritable - 256*1024*1024;
697 else
698 baseAddress = lowestReadOnly;
699 // record that we want dylb slid to fgNextSplitSegAddress
700 this->setSlide(fgNextSplitSegAddress - baseAddress);
701 }
702
703 // build table of segments to map
704 const unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
705 const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
706 _shared_region_mapping_np mappingTable[mappingTableCount];
707 initMappingTable(offsetInFat, mappingTable);
708 uint64_t slide = 0;
709
710 // try map it in privately (don't allow sliding if we pre-calculated the load address to pack dylibs)
711 int r;
712 if ( usemmap )
713 r = _shared_region_map_file_with_mmap(fd, mappingTableCount, mappingTable);
714 else
715 r = _shared_region_map_file_np(fd, mappingTableCount, mappingTable, context.slideAndPackDylibs ? NULL : &slide);
716 if ( 0 == r ) {
717 if ( 0 != slide ) {
718 slide = (slide) & (-4096); // round down to page boundary
719 this->setSlide(slide);
720 }
721 if ( context.verboseMapping ) {
722 if ( slide == 0 )
723 fprintf(stderr, "dyld: Mapping split-seg un-shared %s\n", this->getPath());
724 else
725 fprintf(stderr, "dyld: Mapping split-seg un-shared slid by 0x%08llX %s\n", slide, this->getPath());
726 for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
727 Segment* seg = fSegments[segIndex];
728 const _shared_region_mapping_np* entry = &mappingTable[entryIndex];
729 if ( (entry->init_prot & VM_PROT_ZF) == 0 )
730 fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
731 seg->getName(), seg->getActualLoadAddress(), seg->getActualLoadAddress()+seg->getFileSize()-1);
732 if ( entryIndex < (mappingTableCount-1) ) {
733 const _shared_region_mapping_np* nextEntry = &mappingTable[entryIndex+1];
734 if ( (nextEntry->init_prot & VM_PROT_ZF) != 0 ) {
735 uint64_t segOffset = nextEntry->address - entry->address;
736 fprintf(stderr, "%18s at 0x%08lX->0x%08lX (zerofill)\n",
737 seg->getName(), (uintptr_t)(seg->getActualLoadAddress() + segOffset), (uintptr_t)(seg->getActualLoadAddress() + segOffset + nextEntry->size - 1));
738 ++entryIndex;
739 }
740 }
741 }
742 }
743 if ( context.slideAndPackDylibs ) {
744 // calculate where next split-seg dylib can load
745 uintptr_t largestReadOnly = 0;
746 uintptr_t largestWritable = 0;
747 for (unsigned int segIndex=0; segIndex < segmentCount; ++segIndex) {
748 Segment* seg = fSegments[segIndex];
749 uintptr_t segEnd = seg->getActualLoadAddress()+seg->getSize();
750 segEnd = (segEnd+4095) & (-4096); // page align
751 if ( seg->writeable() ) {
752 if ( segEnd > largestWritable )
753 largestWritable = segEnd;
754 }
755 else {
756 if ( segEnd > largestReadOnly )
757 largestReadOnly = segEnd;
758 }
759 }
760 if ( largestWritable - 256*1024*1024 > largestReadOnly )
761 fgNextSplitSegAddress = largestWritable - 256*1024*1024;
762 else
763 fgNextSplitSegAddress = largestReadOnly;
764 }
765 }
766 if ( context.slideAndPackDylibs && (r != 0) )
767 throwf("can't rebase split-seg dylib %s because shared_region_map_file_np() returned %d", this->getPath(), r);
768
769 return r;
770 }
771
772
773 int
774 ImageLoaderMachO::sharedRegionLoadFile(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
775 {
776
777 // map in split segment file at random address, then tell kernel to share it
778 void* loadAddress = 0;
779 loadAddress = mmap(NULL, fileLen, PROT_READ, MAP_FILE, fd, 0);
780 if ( loadAddress == ((void*)(-1)) )
781 throw "mmap error";
782
783 // calculate mapping entries
784 const unsigned int segmentCount = fSegments.size();
785 unsigned int extraZeroFillEntries = getExtraZeroFillEntriesCount();
786
787 // build table of segments to map
788 const unsigned int mappingTableCount = segmentCount+extraZeroFillEntries;
789 const uintptr_t baseAddress = fSegments[0]->getPreferredLoadAddress();
790 sf_mapping mappingTable[mappingTableCount];
791 initMappingTable(offsetInFat, mappingTable, baseAddress);
792
793
794 // use load_shared_file() to map all segments at once
795 int flags = 0; // might need to set NEW_LOCAL_SHARED_REGIONS on first use
796 static bool firstTime = true;
797 if ( firstTime ) {
798 // when NEW_LOCAL_SHARED_REGIONS bit is set, this process will get is own shared region
799 // this is used by Xcode to prevent development libraries from polluting the global shared segment
800 if ( context.sharedRegionMode == kUsePrivateSharedRegion )
801 flags |= NEW_LOCAL_SHARED_REGIONS;
802 firstTime = false;
803 }
804
805 caddr_t base_address = (caddr_t)baseAddress;
806 kern_return_t r;
807 r = load_shared_file( (char*)fPath, // path of file to map shared
808 (char*)loadAddress, // beginning of local copy of sharable pages in file
809 fileLen, // end of shareable pages in file
810 &base_address, // beginning of address range to map
811 mappingTableCount, // number of entres in array of sf_mapping
812 mappingTable, // the array of sf_mapping
813 &flags); // in/out flags
814 if ( 0 != r ) {
815 // try again but tell kernel it is ok to slide
816 flags |= ALTERNATE_LOAD_SITE;
817 r = load_shared_file((char*)fPath,(char*)loadAddress, fileLen, &base_address,
818 mappingTableCount, mappingTable, &flags);
819 }
820
821 // unmap file from random address now that they are (hopefully) mapped into the shared region
822 munmap(loadAddress, fileLen);
823
824 if ( 0 == r ) {
825 if ( base_address != (caddr_t)baseAddress )
826 this->setSlide((uintptr_t)base_address - baseAddress);
827 if ( context.verboseMapping ) {
828 if ( base_address != (caddr_t)baseAddress )
829 fprintf(stderr, "dyld: Mapping split-seg load_shared_alt_region %s\n", this->getPath());
830 else
831 fprintf(stderr, "dyld: Mapping split-seg load_shared %s\n", this->getPath());
832 for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
833 Segment* seg = fSegments[segIndex];
834 const sf_mapping* entry = &mappingTable[entryIndex];
835 if ( (entry->protection & VM_PROT_ZF) == 0 )
836 fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
837 seg->getName(), seg->getActualLoadAddress(), seg->getActualLoadAddress()+seg->getFileSize()-1);
838 if ( entryIndex < (mappingTableCount-1) ) {
839 const sf_mapping* nextEntry = &mappingTable[entryIndex+1];
840 if ( (nextEntry->protection & VM_PROT_ZF) != 0 ) {
841 fprintf(stderr, "%18s at 0x%08lX->0x%08lX\n",
842 seg->getName(), (uintptr_t)(nextEntry->mapping_offset + base_address), (uintptr_t)(nextEntry->mapping_offset + base_address + nextEntry->size - 1));
843 ++entryIndex;
844 }
845 }
846 }
847 }
848 }
849 return r;
850 }
851 void
852 ImageLoaderMachO::initMappingTable(uint64_t offsetInFat,
853 sf_mapping *mappingTable,
854 uintptr_t baseAddress)
855 {
856 unsigned int segmentCount = fSegments.size();
857 for(unsigned int segIndex=0,entryIndex=0; segIndex < segmentCount; ++segIndex, ++entryIndex){
858 Segment* seg = fSegments[segIndex];
859 sf_mapping* entry = &mappingTable[entryIndex];
860 entry->mapping_offset = seg->getPreferredLoadAddress() - baseAddress;
861 entry->size = seg->getFileSize();
862 entry->file_offset = seg->getFileOffset() + offsetInFat;
863 entry->protection = VM_PROT_NONE;
864 if ( !seg->unaccessible() ) {
865 if ( seg->executable() )
866 entry->protection |= VM_PROT_EXECUTE;
867 if ( seg->readable() )
868 entry->protection |= VM_PROT_READ;
869 if ( seg->writeable() )
870 entry->protection |= VM_PROT_WRITE | VM_PROT_COW;
871 }
872
873 entry->cksum = 0;
874 if ( seg->hasTrailingZeroFill() ) {
875 sf_mapping* zfentry = &mappingTable[++entryIndex];
876 zfentry->mapping_offset = entry->mapping_offset + seg->getFileSize();
877 zfentry->size = seg->getSize() - seg->getFileSize();
878 zfentry->file_offset = 0;
879 zfentry->protection = entry->protection | VM_PROT_COW | VM_PROT_ZF;
880 zfentry->cksum = 0;
881 }
882 }
883 }
884
885 #endif // !__LP64__ split segs not supported for 64-bits
886
887
888 void ImageLoaderMachO::setSlide(intptr_t slide)
889 {
890 fSlide = slide;
891 }
892
893 void ImageLoaderMachO::parseLoadCmds()
894 {
895 // now that segments are mapped in, get real fMachOData, fLinkEditBase, and fSlide
896 const unsigned int segmentCount = fSegments.size();
897 for(unsigned int i=0; i < segmentCount; ++i){
898 Segment* seg = fSegments[i];
899 // set up pointer to __LINKEDIT segment
900 if ( strcmp(seg->getName(),"__LINKEDIT") == 0 )
901 fLinkEditBase = (uint8_t*)(seg->getActualLoadAddress() - seg->getFileOffset());
902 // __TEXT segment always starts at beginning of file and contains mach_header and load commands
903 if ( strcmp(seg->getName(),"__TEXT") == 0 ) {
904 if ( seg->hasFixUps() )
905 fTextSegmentWithFixups = (SegmentMachO*)seg;
906 }
907 // some segment always starts at beginning of file and contains mach_header and load commands
908 if ( (seg->getFileOffset() == 0) && (seg->getFileSize() != 0) ) {
909 fMachOData = (uint8_t*)(seg->getActualLoadAddress());
910 }
911 }
912
913 // keep count of prebound images with weak exports
914 if ( this->hasCoalescedExports() )
915 ++fgCountOfImagesWithWeakExports;
916
917 // walk load commands (mapped in at start of __TEXT segment)
918 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
919 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
920 const struct load_command* cmd = cmds;
921 for (uint32_t i = 0; i < cmd_count; ++i) {
922 switch (cmd->cmd) {
923 case LC_SYMTAB:
924 {
925 const struct symtab_command* symtab = (struct symtab_command*)cmd;
926 fStrings = (const char*)&fLinkEditBase[symtab->stroff];
927 fSymbolTable = (struct macho_nlist*)(&fLinkEditBase[symtab->symoff]);
928 }
929 break;
930 case LC_DYSYMTAB:
931 fDynamicInfo = (struct dysymtab_command*)cmd;
932 break;
933 case LC_SUB_UMBRELLA:
934 fHasSubUmbrella = true;
935 break;
936 case LC_SUB_FRAMEWORK:
937 {
938 const struct sub_framework_command* subf = (struct sub_framework_command*)cmd;
939 fReExportThruFramework = (char*)cmd + subf->umbrella.offset;
940 }
941 break;
942 case LC_SUB_LIBRARY:
943 fHasSubLibraries = true;
944 break;
945 case LC_ROUTINES_COMMAND:
946 fDashInit = (struct macho_routines_command*)cmd;
947 break;
948 case LC_SEGMENT_COMMAND:
949 {
950 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
951 const bool isDataSeg = (strcmp(seg->segname, "__DATA") == 0);
952 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
953 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
954 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
955 const uint8_t type = sect->flags & SECTION_TYPE;
956 if ( type == S_MOD_INIT_FUNC_POINTERS )
957 fModInitSection = sect;
958 else if ( type == S_MOD_TERM_FUNC_POINTERS )
959 fModTermSection = sect;
960 else if ( isDataSeg && (strcmp(sect->sectname, "__dyld") == 0) ) {
961 fDATAdyld = sect;
962 }
963 else if ( isDataSeg && (strcmp(sect->sectname, "__image_notify") == 0) )
964 fImageNotifySection = sect;
965 }
966 }
967 break;
968 case LC_TWOLEVEL_HINTS:
969 fTwoLevelHints = (struct twolevel_hints_command*)cmd;
970 break;
971 case LC_ID_DYLIB:
972 {
973 fDylibID = (struct dylib_command*)cmd;
974 }
975 break;
976 case LC_LOAD_WEAK_DYLIB:
977 // do nothing, just prevent LC_REQ_DYLD exception from occuring
978 break;
979 default:
980 if ( (cmd->cmd & LC_REQ_DYLD) != 0 )
981 throwf("unknown required load command 0x%08X", cmd->cmd);
982 }
983 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
984 }
985 }
986
987
988
989
990 const char* ImageLoaderMachO::getInstallPath() const
991 {
992 if ( fDylibID != NULL ) {
993 return (char*)fDylibID + fDylibID->dylib.name.offset;
994 }
995 return NULL;
996 }
997
998 // test if this image is re-exported through parent (the image that loaded this one)
999 bool ImageLoaderMachO::isSubframeworkOf(const LinkContext& context, const ImageLoader* parent) const
1000 {
1001 if ( fReExportThruFramework != NULL ) {
1002 // need to match LC_SUB_FRAMEWORK string against the leaf name of the install location of parent...
1003 const char* parentInstallPath = parent->getInstallPath();
1004 if ( parentInstallPath != NULL ) {
1005 const char* lastSlash = strrchr(parentInstallPath, '/');
1006 if ( lastSlash != NULL ) {
1007 if ( strcmp(&lastSlash[1], fReExportThruFramework) == 0 )
1008 return true;
1009 if ( context.imageSuffix != NULL ) {
1010 // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
1011 char reexportAndSuffix[strlen(context.imageSuffix)+strlen(fReExportThruFramework)+1];
1012 strcpy(reexportAndSuffix, fReExportThruFramework);
1013 strcat(reexportAndSuffix, context.imageSuffix);
1014 if ( strcmp(&lastSlash[1], reexportAndSuffix) == 0 )
1015 return true;
1016 }
1017 }
1018 }
1019 }
1020 return false;
1021 }
1022
1023 // test if child is re-exported
1024 bool ImageLoaderMachO::hasSubLibrary(const LinkContext& context, const ImageLoader* child) const
1025 {
1026 if ( fHasSubLibraries ) {
1027 // need to match LC_SUB_LIBRARY string against the leaf name (without extension) of the install location of child...
1028 const char* childInstallPath = child->getInstallPath();
1029 if ( childInstallPath != NULL ) {
1030 const char* lastSlash = strrchr(childInstallPath, '/');
1031 if ( lastSlash != NULL ) {
1032 const char* firstDot = strchr(lastSlash, '.');
1033 int len;
1034 if ( firstDot == NULL )
1035 len = strlen(lastSlash);
1036 else
1037 len = firstDot-lastSlash-1;
1038 char childLeafName[len+1];
1039 strncpy(childLeafName, &lastSlash[1], len);
1040 childLeafName[len] = '\0';
1041 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1042 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1043 const struct load_command* cmd = cmds;
1044 for (uint32_t i = 0; i < cmd_count; ++i) {
1045 switch (cmd->cmd) {
1046 case LC_SUB_LIBRARY:
1047 {
1048 const struct sub_library_command* lib = (struct sub_library_command*)cmd;
1049 const char* aSubLibName = (char*)cmd + lib->sub_library.offset;
1050 if ( strcmp(aSubLibName, childLeafName) == 0 )
1051 return true;
1052 if ( context.imageSuffix != NULL ) {
1053 // when DYLD_IMAGE_SUFFIX is used, childLeafName string needs imageSuffix removed from end
1054 char aSubLibNameAndSuffix[strlen(context.imageSuffix)+strlen(aSubLibName)+1];
1055 strcpy(aSubLibNameAndSuffix, aSubLibName);
1056 strcat(aSubLibNameAndSuffix, context.imageSuffix);
1057 if ( strcmp(aSubLibNameAndSuffix, childLeafName) == 0 )
1058 return true;
1059 }
1060 }
1061 break;
1062 }
1063 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1064 }
1065 }
1066 }
1067 }
1068 if ( fHasSubUmbrella ) {
1069 // need to match LC_SUB_UMBRELLA string against the leaf name of install location of child...
1070 const char* childInstallPath = child->getInstallPath();
1071 if ( childInstallPath != NULL ) {
1072 const char* lastSlash = strrchr(childInstallPath, '/');
1073 if ( lastSlash != NULL ) {
1074 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1075 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1076 const struct load_command* cmd = cmds;
1077 for (uint32_t i = 0; i < cmd_count; ++i) {
1078 switch (cmd->cmd) {
1079 case LC_SUB_UMBRELLA:
1080 {
1081 const struct sub_umbrella_command* um = (struct sub_umbrella_command*)cmd;
1082 const char* aSubUmbrellaName = (char*)cmd + um->sub_umbrella.offset;
1083 if ( strcmp(aSubUmbrellaName, &lastSlash[1]) == 0 )
1084 return true;
1085 if ( context.imageSuffix != NULL ) {
1086 // when DYLD_IMAGE_SUFFIX is used, lastSlash string needs imageSuffix removed from end
1087 char umbrellaAndSuffix[strlen(context.imageSuffix)+strlen(aSubUmbrellaName)+1];
1088 strcpy(umbrellaAndSuffix, aSubUmbrellaName);
1089 strcat(umbrellaAndSuffix, context.imageSuffix);
1090 if ( strcmp(umbrellaAndSuffix, &lastSlash[1]) == 0 )
1091 return true;
1092 }
1093 }
1094 break;
1095 }
1096 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1097 }
1098 }
1099 }
1100 }
1101 return false;
1102 }
1103
1104
1105 void* ImageLoaderMachO::getMain() const
1106 {
1107 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1108 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1109 const struct load_command* cmd = cmds;
1110 for (unsigned long i = 0; i < cmd_count; ++i) {
1111 switch (cmd->cmd) {
1112 case LC_UNIXTHREAD:
1113 {
1114 #if __ppc__
1115 const ppc_thread_state_t* registers = (ppc_thread_state_t*)(((char*)cmd) + 16);
1116 return (void*)registers->srr0;
1117 #elif __ppc64__
1118 const ppc_thread_state64_t* registers = (ppc_thread_state64_t*)(((char*)cmd) + 16);
1119 return (void*)registers->srr0;
1120 #elif __i386__
1121 const i386_thread_state_t* registers = (i386_thread_state_t*)(((char*)cmd) + 16);
1122 return (void*)registers->eip;
1123 #else
1124 #warning need processor specific code
1125 #endif
1126 }
1127 break;
1128 }
1129 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1130 }
1131 return NULL;
1132 }
1133
1134
1135 uint32_t ImageLoaderMachO::doGetDependentLibraryCount()
1136 {
1137 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1138 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1139 uint32_t count = 0;
1140 const struct load_command* cmd = cmds;
1141 for (unsigned long i = 0; i < cmd_count; ++i) {
1142 switch (cmd->cmd) {
1143 case LC_LOAD_DYLIB:
1144 case LC_LOAD_WEAK_DYLIB:
1145 ++count;
1146 break;
1147 }
1148 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1149 }
1150 return count;
1151 }
1152
1153 void ImageLoaderMachO::doGetDependentLibraries(DependentLibrary libs[])
1154 {
1155 uint32_t index = 0;
1156 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1157 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1158 const struct load_command* cmd = cmds;
1159 for (unsigned long i = 0; i < cmd_count; ++i) {
1160 switch (cmd->cmd) {
1161 case LC_LOAD_DYLIB:
1162 case LC_LOAD_WEAK_DYLIB:
1163 {
1164 const struct dylib_command* dylib = (struct dylib_command*)cmd;
1165 DependentLibrary* lib = &libs[index++];
1166 lib->name = (char*)cmd + dylib->dylib.name.offset;
1167 //lib->name = strdup((char*)cmd + dylib->dylib.name.offset);
1168 lib->image = NULL;
1169 lib->info.checksum = dylib->dylib.timestamp;
1170 lib->info.minVersion = dylib->dylib.compatibility_version;
1171 lib->info.maxVersion = dylib->dylib.current_version;
1172 lib->required = (cmd->cmd == LC_LOAD_DYLIB);
1173 lib->checksumMatches = false;
1174 lib->isReExported = false;
1175 }
1176 break;
1177 }
1178 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1179 }
1180 }
1181
1182 ImageLoader::LibraryInfo ImageLoaderMachO::doGetLibraryInfo()
1183 {
1184 LibraryInfo info;
1185 if ( fDylibID != NULL ) {
1186 info.minVersion = fDylibID->dylib.compatibility_version;
1187 info.maxVersion = fDylibID->dylib.current_version;
1188 info.checksum = fDylibID->dylib.timestamp;
1189 }
1190 else {
1191 info.minVersion = 0;
1192 info.maxVersion = 0;
1193 info.checksum = 0;
1194 }
1195 return info;
1196 }
1197
1198 uintptr_t ImageLoaderMachO::getFirstWritableSegmentAddress()
1199 {
1200 // in split segment libraries r_address is offset from first writable segment
1201 for (std::vector<class Segment*>::iterator it=fSegments.begin(); it != fSegments.end(); ++it) {
1202 if ( (*it)->writeable() ) {
1203 return (*it)->getActualLoadAddress();
1204 }
1205 }
1206 throw "no writable segment";
1207 }
1208
1209 uintptr_t ImageLoaderMachO::getRelocBase()
1210 {
1211 #if __ppc__ || __i386__
1212 if ( fIsSplitSeg ) {
1213 // in split segment libraries r_address is offset from first writable segment
1214 return getFirstWritableSegmentAddress();
1215 }
1216 #endif
1217
1218 // in non-split segment libraries r_address is offset from first segment
1219 return fSegments[0]->getActualLoadAddress();
1220 }
1221
1222 #if __ppc__
1223 static inline void otherRelocsPPC(uintptr_t* locationToFix, uint8_t relocationType, uint16_t otherHalf, uintptr_t slide)
1224 {
1225 // low 16 bits of 32-bit ppc instructions need fixing
1226 struct ppcInstruction { uint16_t opcode; int16_t immediateValue; };
1227 ppcInstruction* instruction = (ppcInstruction*)locationToFix;
1228 //uint32_t before = *((uint32_t*)locationToFix);
1229 switch ( relocationType )
1230 {
1231 case PPC_RELOC_LO16:
1232 instruction->immediateValue = ((otherHalf << 16) | instruction->immediateValue) + slide;
1233 break;
1234 case PPC_RELOC_HI16:
1235 instruction->immediateValue = ((((instruction->immediateValue << 16) | otherHalf) + slide) >> 16);
1236 break;
1237 case PPC_RELOC_HA16:
1238 int16_t signedOtherHalf = (int16_t)(otherHalf & 0xffff);
1239 uint32_t temp = (instruction->immediateValue << 16) + signedOtherHalf + slide;
1240 if ( (temp & 0x00008000) != 0 )
1241 temp += 0x00008000;
1242 instruction->immediateValue = temp >> 16;
1243 }
1244 //uint32_t after = *((uint32_t*)locationToFix);
1245 //fprintf(stderr, "dyld: ppc fixup %0p type %d from 0x%08X to 0x%08X\n", locationToFix, relocationType, before, after);
1246 }
1247 #endif
1248
1249 void ImageLoaderMachO::doRebase(const LinkContext& context)
1250 {
1251 // if prebound and loaded at prebound address, then no need to rebase
1252 // Note: you might think that the check for allDependentLibrariesAsWhenPreBound() is not needed
1253 // but it is. If a dependent library changed, this image's lazy pointers into that library
1254 // need to be updated (reset back to lazy binding handler). That work is done most easily
1255 // here because there is a PPC_RELOC_PB_LA_PTR reloc record for each lazy pointer.
1256 if ( this->usablePrebinding(context) && this->usesTwoLevelNameSpace() ) {
1257 // skip rebasing cause prebound and prebinding not disabled
1258 ++fgImagesWithUsedPrebinding; // bump totals for statistics
1259 return;
1260 }
1261
1262 // print why prebinding was not used
1263 if ( context.verbosePrebinding ) {
1264 if ( !this->isPrebindable() ) {
1265 fprintf(stderr, "dyld: image not prebound, so could not use prebinding in %s\n", this->getPath());
1266 }
1267 else if ( fSlide != 0 ) {
1268 fprintf(stderr, "dyld: image slid, so could not use prebinding in %s\n", this->getPath());
1269 }
1270 else if ( !this->allDependentLibrariesAsWhenPreBound() ) {
1271 fprintf(stderr, "dyld: dependent libraries changed, so could not use prebinding in %s\n", this->getPath());
1272 }
1273 else if ( !this->usesTwoLevelNameSpace() ){
1274 fprintf(stderr, "dyld: image uses flat-namespace so, parts of prebinding ignored %s\n", this->getPath());
1275 }
1276 else {
1277 fprintf(stderr, "dyld: environment variable disabled use of prebinding in %s\n", this->getPath());
1278 }
1279 }
1280
1281 // if there are __TEXT fixups, temporarily make __TEXT writable
1282 if ( fTextSegmentWithFixups != NULL )
1283 fTextSegmentWithFixups->tempWritable();
1284
1285 // cache this value that is used in the following loop
1286 register const uintptr_t slide = this->fSlide;
1287
1288 // loop through all local (internal) relocation records
1289 const uintptr_t relocBase = this->getRelocBase();
1290 const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->locreloff]);
1291 const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nlocrel];
1292 for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
1293 #if __ppc__ || __ppc64__ || __i386__
1294 if ( (reloc->r_address & R_SCATTERED) == 0 ) {
1295 if ( reloc->r_symbolnum == R_ABS ) {
1296 // ignore absolute relocations
1297 }
1298 else if (reloc->r_length == RELOC_SIZE) {
1299 switch(reloc->r_type) {
1300 case GENERIC_RELOC_VANILLA:
1301 *((uintptr_t*)(reloc->r_address + relocBase)) += slide;
1302 break;
1303 #if __ppc__
1304 case PPC_RELOC_HI16:
1305 case PPC_RELOC_LO16:
1306 case PPC_RELOC_HA16:
1307 // some tools leave object file relocations in linked images
1308 otherRelocsPPC((uintptr_t*)(reloc->r_address + relocBase), reloc->r_type, reloc[1].r_address, slide);
1309 ++reloc; // these relocations come in pairs, skip next
1310 break;
1311 #endif
1312 default:
1313 throw "unknown local relocation type";
1314 }
1315 }
1316 else {
1317 throw "bad local relocation length";
1318 }
1319 }
1320 else {
1321 const struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
1322 if (sreloc->r_length == RELOC_SIZE) {
1323 uintptr_t* locationToFix = (uintptr_t*)(sreloc->r_address + relocBase);
1324 switch(sreloc->r_type) {
1325 case GENERIC_RELOC_VANILLA:
1326 *locationToFix += slide;
1327 break;
1328 #if __ppc__ || __ppc64__
1329 case PPC_RELOC_PB_LA_PTR:
1330 // should only see these in prebound images, and we got here so prebinding is being ignored
1331 *locationToFix = sreloc->r_value + slide;
1332 break;
1333 #endif
1334 #if __ppc__
1335 case PPC_RELOC_HI16:
1336 case PPC_RELOC_LO16:
1337 case PPC_RELOC_HA16:
1338 // Metrowerks compiler sometimes leaves object file relocations in linked images???
1339 ++reloc; // these relocations come in pairs, get next one
1340 otherRelocsPPC(locationToFix, sreloc->r_type, reloc->r_address, slide);
1341 break;
1342 #endif
1343 #if __i386__
1344 case GENERIC_RELOC_PB_LA_PTR:
1345 // should only see these in prebound images, and we got here so prebinding is being ignored
1346 *locationToFix = sreloc->r_value + slide;
1347 break;
1348 #endif
1349 default:
1350 throw "unknown local scattered relocation type";
1351 }
1352 }
1353 else {
1354 throw "bad local scattered relocation length";
1355 }
1356 }
1357 #endif
1358 }
1359
1360 // if there were __TEXT fixups, restore write protection
1361 if ( fTextSegmentWithFixups != NULL ) {
1362 fTextSegmentWithFixups->setPermissions();
1363 sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(), fTextSegmentWithFixups->getSize());
1364 }
1365
1366 // update stats
1367 fgTotalRebaseFixups += fDynamicInfo->nlocrel;
1368 }
1369
1370
1371 const struct macho_nlist* ImageLoaderMachO::binarySearchWithToc(const char* key, const char stringPool[], const struct macho_nlist symbols[],
1372 const struct dylib_table_of_contents toc[], uint32_t symbolCount, uint32_t hintIndex)
1373 {
1374 int32_t high = symbolCount-1;
1375 int32_t mid = hintIndex;
1376
1377 // handle out of range hint
1378 if ( mid >= (int32_t)symbolCount ) {
1379 mid = symbolCount/2;
1380 ++ImageLoaderMachO::fgUnhintedBinaryTreeSearchs;
1381 }
1382 else {
1383 ++ImageLoaderMachO::fgHintedBinaryTreeSearchs;
1384 }
1385
1386 for (int32_t low = 0; low <= high; mid = (low+high)/2) {
1387 const uint32_t index = toc[mid].symbol_index;
1388 const struct macho_nlist* pivot = &symbols[index];
1389 const char* pivotStr = &stringPool[pivot->n_un.n_strx];
1390 #if LINKEDIT_USAGE_DEBUG
1391 noteAccessedLinkEditAddress(&toc[mid]);
1392 noteAccessedLinkEditAddress(pivot);
1393 noteAccessedLinkEditAddress(pivotStr);
1394 #endif
1395 int cmp = astrcmp(key, pivotStr);
1396 if ( cmp == 0 )
1397 return pivot;
1398 if ( cmp > 0 ) {
1399 // key > pivot
1400 low = mid + 1;
1401 }
1402 else {
1403 // key < pivot
1404 high = mid - 1;
1405 }
1406 }
1407 return NULL;
1408 }
1409
1410 const struct macho_nlist* ImageLoaderMachO::binarySearch(const char* key, const char stringPool[], const struct macho_nlist symbols[], uint32_t symbolCount)
1411 {
1412 ++ImageLoaderMachO::fgUnhintedBinaryTreeSearchs;
1413 const struct macho_nlist* base = symbols;
1414 for (uint32_t n = symbolCount; n > 0; n /= 2) {
1415 const struct macho_nlist* pivot = &base[n/2];
1416 const char* pivotStr = &stringPool[pivot->n_un.n_strx];
1417 #if LINKEDIT_USAGE_DEBUG
1418 noteAccessedLinkEditAddress(pivot);
1419 noteAccessedLinkEditAddress(pivotStr);
1420 #endif
1421 int cmp = astrcmp(key, pivotStr);
1422 if ( cmp == 0 )
1423 return pivot;
1424 if ( cmp > 0 ) {
1425 // key > pivot
1426 // move base to symbol after pivot
1427 base = &pivot[1];
1428 --n;
1429 }
1430 else {
1431 // key < pivot
1432 // keep same base
1433 }
1434 }
1435 return NULL;
1436 }
1437
1438 const ImageLoader::Symbol* ImageLoaderMachO::findExportedSymbol(const char* name, const void* hint, bool searchReExports, ImageLoader** foundIn) const
1439 {
1440 const struct macho_nlist* sym = NULL;
1441 const struct twolevel_hint* theHint = (struct twolevel_hint*)hint;
1442 if ( fDynamicInfo->tocoff == 0 )
1443 sym = binarySearch(name, fStrings, &fSymbolTable[fDynamicInfo->iextdefsym], fDynamicInfo->nextdefsym);
1444 else {
1445 uint32_t start = fDynamicInfo->nextdefsym;
1446 if ( theHint != NULL )
1447 start = theHint->itoc;
1448 if ( (theHint == NULL) || (theHint->isub_image == 0) ) {
1449 sym = binarySearchWithToc(name, fStrings, fSymbolTable, (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff],
1450 fDynamicInfo->ntoc, start);
1451 }
1452 }
1453 if ( sym != NULL ) {
1454 if ( foundIn != NULL )
1455 *foundIn = (ImageLoader*)this;
1456
1457 return (const Symbol*)sym;
1458 }
1459
1460 if ( searchReExports ) {
1461 // hint might tell us to try a particular subimage
1462 if ( (theHint != NULL) && (theHint->isub_image > 0) && (theHint->isub_image <= fLibrariesCount) ) {
1463 // isub_image is an index into a list that is sorted non-rexported images first
1464 uint32_t index = 0;
1465 ImageLoader* target = NULL;
1466 // pass one, only look at sub-frameworks
1467 for (uint32_t i=0; i < fLibrariesCount; ++i) {
1468 DependentLibrary& libInfo = fLibraries[i];
1469 if ( libInfo.isSubFramework && (libInfo.image != NULL)) {
1470 if ( ++index == theHint->isub_image ) {
1471 target = libInfo.image;
1472 break;
1473 }
1474 }
1475 }
1476 if (target != NULL) {
1477 // pass two, only look at non-sub-framework-reexports
1478 for (uint32_t i=0; i < fLibrariesCount; ++i) {
1479 DependentLibrary& libInfo = fLibraries[i];
1480 if ( libInfo.isReExported && !libInfo.isSubFramework && (libInfo.image != NULL) ) {
1481 if ( ++index == theHint->isub_image ) {
1482 target = libInfo.image;
1483 break;
1484 }
1485 }
1486 }
1487 }
1488 if (target != NULL) {
1489 const Symbol* result = target->findExportedSymbol(name, NULL, searchReExports, foundIn);
1490 if ( result != NULL )
1491 return result;
1492 }
1493 }
1494
1495 // hint failed, try all sub images
1496 // pass one, only look at sub-frameworks
1497 for(unsigned int i=0; i < fLibrariesCount; ++i){
1498 DependentLibrary& libInfo = fLibraries[i];
1499 if ( (libInfo.image != NULL) && libInfo.isSubFramework ) {
1500 const Symbol* result = libInfo.image->findExportedSymbol(name, NULL, searchReExports, foundIn);
1501 if ( result != NULL )
1502 return result;
1503 }
1504 }
1505 // pass two, only look at non-sub-framework-reexports
1506 for(unsigned int i=0; i < fLibrariesCount; ++i){
1507 DependentLibrary& libInfo = fLibraries[i];
1508 if ( (libInfo.image != NULL) && libInfo.isReExported && !libInfo.isSubFramework ) {
1509 const Symbol* result = libInfo.image->findExportedSymbol(name, NULL, searchReExports, foundIn);
1510 if ( result != NULL )
1511 return result;
1512 }
1513 }
1514 }
1515
1516 // last change: the hint is wrong (non-zero but actually in this image)
1517 if ( (theHint != NULL) && (theHint->isub_image != 0) ) {
1518 sym = binarySearchWithToc(name, fStrings, fSymbolTable, (dylib_table_of_contents*)&fLinkEditBase[fDynamicInfo->tocoff],
1519 fDynamicInfo->ntoc, fDynamicInfo->nextdefsym);
1520 if ( sym != NULL ) {
1521 if ( foundIn != NULL )
1522 *foundIn = (ImageLoader*)this;
1523 return (const Symbol*)sym;
1524 }
1525 }
1526
1527
1528 return NULL;
1529 }
1530
1531
1532 uintptr_t ImageLoaderMachO::getExportedSymbolAddress(const Symbol* sym) const
1533 {
1534 const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
1535 return nlistSym->n_value + fSlide;
1536 }
1537
1538 ImageLoader::DefinitionFlags ImageLoaderMachO::getExportedSymbolInfo(const Symbol* sym) const
1539 {
1540 const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
1541 if ( (nlistSym->n_desc & N_WEAK_DEF) != 0 )
1542 return kWeakDefinition;
1543 return kNoDefinitionOptions;
1544 }
1545
1546 const char* ImageLoaderMachO::getExportedSymbolName(const Symbol* sym) const
1547 {
1548 const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
1549 return &fStrings[nlistSym->n_un.n_strx];
1550 }
1551
1552 uint32_t ImageLoaderMachO::getExportedSymbolCount() const
1553 {
1554 return fDynamicInfo->nextdefsym;
1555 }
1556
1557
1558 const ImageLoader::Symbol* ImageLoaderMachO::getIndexedExportedSymbol(uint32_t index) const
1559 {
1560 if ( index < fDynamicInfo->nextdefsym ) {
1561 const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iextdefsym + index];
1562 return (const ImageLoader::Symbol*)sym;
1563 }
1564 return NULL;
1565 }
1566
1567
1568 uint32_t ImageLoaderMachO::getImportedSymbolCount() const
1569 {
1570 return fDynamicInfo->nundefsym;
1571 }
1572
1573
1574 const ImageLoader::Symbol* ImageLoaderMachO::getIndexedImportedSymbol(uint32_t index) const
1575 {
1576 if ( index < fDynamicInfo->nundefsym ) {
1577 const struct macho_nlist* sym = &fSymbolTable[fDynamicInfo->iundefsym + index];
1578 return (const ImageLoader::Symbol*)sym;
1579 }
1580 return NULL;
1581 }
1582
1583
1584 ImageLoader::ReferenceFlags ImageLoaderMachO::geImportedSymbolInfo(const ImageLoader::Symbol* sym) const
1585 {
1586 const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
1587 ImageLoader::ReferenceFlags flags = kNoReferenceOptions;
1588 if ( ((nlistSym->n_type & N_TYPE) == N_UNDF) && (nlistSym->n_value != 0) )
1589 flags |= ImageLoader::kTentativeDefinition;
1590 if ( (nlistSym->n_desc & N_WEAK_REF) != 0 )
1591 flags |= ImageLoader::kWeakReference;
1592 return flags;
1593 }
1594
1595
1596 const char* ImageLoaderMachO::getImportedSymbolName(const ImageLoader::Symbol* sym) const
1597 {
1598 const struct macho_nlist* nlistSym = (const struct macho_nlist*)sym;
1599 return &fStrings[nlistSym->n_un.n_strx];
1600 }
1601
1602
1603 bool ImageLoaderMachO::getSectionContent(const char* segmentName, const char* sectionName, void** start, size_t* length)
1604 {
1605 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1606 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1607 const struct load_command* cmd = cmds;
1608 for (uint32_t i = 0; i < cmd_count; ++i) {
1609 switch (cmd->cmd) {
1610 case LC_SEGMENT_COMMAND:
1611 {
1612 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
1613 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
1614 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
1615 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
1616 if ( (strcmp(sect->segname, segmentName) == 0) && (strcmp(sect->sectname, sectionName) == 0) ) {
1617 *start = (uintptr_t*)(sect->addr + fSlide);
1618 *length = sect->size;
1619 return true;
1620 }
1621 }
1622 }
1623 break;
1624 }
1625 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1626 }
1627 return false;
1628 }
1629
1630
1631 bool ImageLoaderMachO::findSection(const void* imageInterior, const char** segmentName, const char** sectionName, size_t* sectionOffset)
1632 {
1633 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1634 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1635 const struct load_command* cmd = cmds;
1636 const uintptr_t unslidInteriorAddress = (uintptr_t)imageInterior - this->getSlide();
1637 for (uint32_t i = 0; i < cmd_count; ++i) {
1638 switch (cmd->cmd) {
1639 case LC_SEGMENT_COMMAND:
1640 {
1641 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
1642 if ( (unslidInteriorAddress >= seg->vmaddr) && (unslidInteriorAddress < (seg->vmaddr+seg->vmsize)) ) {
1643 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
1644 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
1645 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
1646 if ((sect->addr <= unslidInteriorAddress) && (unslidInteriorAddress < (sect->addr+sect->size))) {
1647 if ( segmentName != NULL )
1648 *segmentName = sect->segname;
1649 if ( sectionName != NULL )
1650 *sectionName = sect->sectname;
1651 if ( sectionOffset != NULL )
1652 *sectionOffset = unslidInteriorAddress - sect->addr;
1653 return true;
1654 }
1655 }
1656 }
1657 }
1658 break;
1659 }
1660 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1661 }
1662 return false;
1663 }
1664
1665
1666 bool ImageLoaderMachO::symbolRequiresCoalescing(const struct macho_nlist* symbol)
1667 {
1668 // if a define and weak ==> coalesced
1669 if ( ((symbol->n_type & N_TYPE) == N_SECT) && ((symbol->n_desc & N_WEAK_DEF) != 0) )
1670 return true;
1671 // if an undefine and not referencing a weak symbol ==> coalesced
1672 if ( ((symbol->n_type & N_TYPE) != N_SECT) && ((symbol->n_desc & N_REF_TO_WEAK) != 0) )
1673 return true;
1674
1675 // regular symbol
1676 return false;
1677 }
1678
1679
1680 static void __attribute__((noreturn)) throwSymbolNotFound(const char* symbol, const char* referencedFrom, const char* expectedIn)
1681 {
1682 const char* formatString = "Symbol not found: %s\n Referenced from: %s\n Expected in: %s\n";
1683 char buf[strlen(symbol)+strlen(referencedFrom)+strlen(expectedIn)+strlen(formatString)];
1684 sprintf(buf, formatString, symbol, referencedFrom, expectedIn);
1685 throw strdup(buf); // this is a leak if exception doesn't halt program
1686 }
1687
1688 uintptr_t ImageLoaderMachO::resolveUndefined(const LinkContext& context, const struct macho_nlist* undefinedSymbol, bool twoLevel, ImageLoader** foundIn)
1689 {
1690 const char* symbolName = &fStrings[undefinedSymbol->n_un.n_strx];
1691
1692 if ( context.bindFlat || !twoLevel ) {
1693 // flat lookup
1694 const Symbol* sym;
1695 if ( context.flatExportFinder(symbolName, &sym, foundIn) )
1696 return (*foundIn)->getExportedSymbolAddress(sym);
1697 // if a bundle is loaded privately the above will not find its exports
1698 if ( this->isBundle() && this->hasHiddenExports() ) {
1699 // look in self for needed symbol
1700 sym = this->findExportedSymbol(symbolName, NULL, false, foundIn);
1701 if ( sym != NULL )
1702 return (*foundIn)->getExportedSymbolAddress(sym);
1703 }
1704 if ( ((undefinedSymbol->n_type & N_PEXT) != 0) || ((undefinedSymbol->n_type & N_TYPE) == N_SECT) ) {
1705 // could be a multi-module private_extern internal reference
1706 // the static linker squirrels away the target address in n_value
1707 uintptr_t addr = undefinedSymbol->n_value + this->fSlide;
1708 *foundIn = this;
1709 return addr;
1710 }
1711 if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
1712 // definition can't be found anywhere
1713 // if reference is weak_import, then it is ok, just return 0
1714 return 0;
1715 }
1716 throwSymbolNotFound(symbolName, this->getPath(), "flat namespace");
1717 }
1718 else {
1719 // symbol requires searching images with coalesced symbols
1720 if ( this->needsCoalescing() && symbolRequiresCoalescing(undefinedSymbol) ) {
1721 const Symbol* sym;
1722 if ( context.coalescedExportFinder(symbolName, &sym, foundIn) )
1723 return (*foundIn)->getExportedSymbolAddress(sym);
1724 //throwSymbolNotFound(symbolName, this->getPath(), "coalesced namespace");
1725 //fprintf(stderr, "dyld: coalesced symbol %s not found in any coalesced image, falling back to two-level lookup", symbolName);
1726 }
1727
1728 // two level lookup
1729 void* hint = NULL;
1730 ImageLoader* target = NULL;
1731 uint8_t ord = GET_LIBRARY_ORDINAL(undefinedSymbol->n_desc);
1732 if ( ord == EXECUTABLE_ORDINAL ) {
1733 target = context.mainExecutable;
1734 }
1735 else if ( ord == SELF_LIBRARY_ORDINAL ) {
1736 target = this;
1737 }
1738 else if ( ord == DYNAMIC_LOOKUP_ORDINAL ) {
1739 // rnielsen: HACKHACK
1740 // flat lookup
1741 const Symbol* sym;
1742 if ( context.flatExportFinder(symbolName, &sym, foundIn) )
1743 return (*foundIn)->getExportedSymbolAddress(sym);
1744 // no image has exports this symbol
1745 // either report error or hope ZeroLink can just-in-time load an image
1746 context.undefinedHandler(symbolName);
1747 // try looking again
1748 if ( context.flatExportFinder(symbolName, &sym, foundIn) )
1749 return (*foundIn)->getExportedSymbolAddress(sym);
1750
1751 throwSymbolNotFound(symbolName, this->getPath(), "dynamic lookup");
1752 }
1753 else if ( ord <= fLibrariesCount ) {
1754 DependentLibrary& libInfo = fLibraries[ord-1];
1755 target = libInfo.image;
1756 if ( (target == NULL) && (((undefinedSymbol->n_desc & N_WEAK_REF) != 0) || !libInfo.required) ) {
1757 // if target library not loaded and reference is weak or library is weak return 0
1758 return 0;
1759 }
1760 }
1761 else {
1762 throw "corrupt binary, library ordinal too big";
1763 }
1764
1765 if ( target == NULL ) {
1766 fprintf(stderr, "resolveUndefined(%s) in %s\n", symbolName, this->getPath());
1767 throw "symbol not found";
1768 }
1769
1770 // interpret hint
1771 if ( fTwoLevelHints != NULL ) {
1772 uint32_t symIndex = undefinedSymbol - fSymbolTable;
1773 int32_t undefinedIndex = symIndex - fDynamicInfo->iundefsym;
1774 if ( (undefinedIndex >= 0) && ((uint32_t)undefinedIndex < fDynamicInfo->nundefsym) ) {
1775 const struct twolevel_hint* hints = (struct twolevel_hint*)(&fLinkEditBase[fTwoLevelHints->offset]);
1776 const struct twolevel_hint* theHint = &hints[undefinedIndex];
1777 hint = (void*)theHint;
1778 }
1779 }
1780
1781 const Symbol* sym = target->findExportedSymbol(symbolName, hint, true, foundIn);
1782 if ( sym!= NULL ) {
1783 return (*foundIn)->getExportedSymbolAddress(sym);
1784 }
1785 else if ( (undefinedSymbol->n_type & N_PEXT) != 0 ) {
1786 // don't know why the static linker did not eliminate the internal reference to a private extern definition
1787 *foundIn = this;
1788 return undefinedSymbol->n_value + fSlide;
1789 }
1790 else if ( (undefinedSymbol->n_desc & N_WEAK_REF) != 0 ) {
1791 // if definition not found and reference is weak return 0
1792 return 0;
1793 }
1794
1795 // nowhere to be found
1796 throwSymbolNotFound(symbolName, this->getPath(), target->getPath());
1797 }
1798 }
1799
1800 // returns if 'addr' is within the address range of section 'sectionIndex'
1801 // fSlide is not used. 'addr' is assumed to be a prebound address in this image
1802 bool ImageLoaderMachO::isAddrInSection(uintptr_t addr, uint8_t sectionIndex)
1803 {
1804 uint8_t currentSectionIndex = 1;
1805 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1806 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1807 const struct load_command* cmd = cmds;
1808 for (unsigned long i = 0; i < cmd_count; ++i) {
1809 if ( cmd->cmd == LC_SEGMENT_COMMAND ) {
1810 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
1811 if ( (currentSectionIndex <= sectionIndex) && (sectionIndex < currentSectionIndex+seg->nsects) ) {
1812 // 'sectionIndex' is in this segment, get section info
1813 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
1814 const struct macho_section* const section = &sectionsStart[sectionIndex-currentSectionIndex];
1815 return ( (section->addr <= addr) && (addr < section->addr+section->size) );
1816 }
1817 else {
1818 // 'sectionIndex' not in this segment, skip to next segment
1819 currentSectionIndex += seg->nsects;
1820 }
1821 }
1822 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
1823 }
1824
1825 return false;
1826 }
1827
1828 void ImageLoaderMachO::doBindExternalRelocations(const LinkContext& context, bool onlyCoalescedSymbols)
1829 {
1830 const uintptr_t relocBase = this->getRelocBase();
1831 const bool twoLevel = this->usesTwoLevelNameSpace();
1832 const bool prebound = this->isPrebindable();
1833
1834 // if there are __TEXT fixups, temporarily make __TEXT writable
1835 if ( fTextSegmentWithFixups != NULL )
1836 fTextSegmentWithFixups->tempWritable();
1837
1838 // cache last lookup
1839 const struct macho_nlist* lastUndefinedSymbol = 0;
1840 uintptr_t symbolAddr = 0;
1841 ImageLoader* image = NULL;
1842
1843 // loop through all external relocation records and bind each
1844 const relocation_info* const relocsStart = (struct relocation_info*)(&fLinkEditBase[fDynamicInfo->extreloff]);
1845 const relocation_info* const relocsEnd = &relocsStart[fDynamicInfo->nextrel];
1846 for (const relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
1847 if (reloc->r_length == RELOC_SIZE) {
1848 switch(reloc->r_type) {
1849 case POINTER_RELOC:
1850 {
1851 const struct macho_nlist* undefinedSymbol = &fSymbolTable[reloc->r_symbolnum];
1852 // if only processing coalesced symbols and this one does not require coalesceing, skip to next
1853 if ( onlyCoalescedSymbols && !symbolRequiresCoalescing(undefinedSymbol) )
1854 continue;
1855 uintptr_t* location = ((uintptr_t*)(reloc->r_address + relocBase));
1856 uintptr_t value = *location;
1857 #if __i386__
1858 if ( reloc->r_pcrel ) {
1859 value += (uintptr_t)location + 4 - fSlide;
1860 }
1861 #endif
1862 if ( prebound ) {
1863 // we are doing relocations, so prebinding was not usable
1864 // in a prebound executable, the n_value field of an undefined symbol is set to the address where the symbol was found when prebound
1865 // so, subtracting that gives the initial displacement which we need to add to the newly found symbol address
1866 // if mach-o relocation structs had an "addend" field this complication would not be necessary.
1867 if ( ((undefinedSymbol->n_type & N_TYPE) == N_SECT) && ((undefinedSymbol->n_desc & N_WEAK_DEF) != 0) ) {
1868 // weak symbols need special casing, since *location may have been prebound to a definition in another image.
1869 // If *location is currently prebound to somewhere in the same section as the weak definition, we assume
1870 // that we can subtract off the weak symbol address to get the addend.
1871 // If prebound elsewhere, we've lost the addend and have to assume it is zero.
1872 // The prebinding to elsewhere only happens with 10.4+ update_prebinding which only operates on a small set of Apple dylibs
1873 if ( (value == undefinedSymbol->n_value) || this->isAddrInSection(value, undefinedSymbol->n_sect) )
1874 value -= undefinedSymbol->n_value;
1875 else
1876 value = 0;
1877 }
1878 else {
1879 // is undefined or non-weak symbol, so do subtraction to get addend
1880 value -= undefinedSymbol->n_value;
1881 }
1882 }
1883 // if undefinedSymbol is same as last time, then symbolAddr and image will resolve to the same too
1884 if ( undefinedSymbol != lastUndefinedSymbol ) {
1885 symbolAddr = this->resolveUndefined(context, undefinedSymbol, twoLevel, &image);
1886 lastUndefinedSymbol = undefinedSymbol;
1887 }
1888 if ( context.verboseBind ) {
1889 const char *path = NULL;
1890 if(NULL != image) {
1891 path = image->getShortName();
1892 }
1893 if(0 == value) {
1894 fprintf(stderr, "dyld: bind: %s:0x%08lx = %s:%s, *0x%08lx = 0x%08lx\n",
1895 this->getShortName(), (uintptr_t)location,
1896 path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr);
1897 }
1898 else {
1899 fprintf(stderr, "dyld: bind: %s:0x%08lx = %s:%s, *0x%08lx = 0x%08lx + %ld\n",
1900 this->getShortName(), (uintptr_t)location,
1901 path, &fStrings[undefinedSymbol->n_un.n_strx], (uintptr_t)location, symbolAddr, value);
1902 }
1903 }
1904 value += symbolAddr;
1905 #if __i386__
1906 if ( reloc->r_pcrel ) {
1907 *location = value - ((uintptr_t)location + 4);
1908 }
1909 else {
1910 // don't dirty page if prebound value was correct
1911 if ( !prebound || (*location != value) )
1912 *location = value;
1913 }
1914 #else
1915 // don't dirty page if prebound value was correct
1916 if ( !prebound || (*location != value) )
1917 *location = value;
1918 #endif
1919 }
1920 break;
1921 default:
1922 throw "unknown external relocation type";
1923 }
1924 }
1925 else {
1926 throw "bad external relocation length";
1927 }
1928 }
1929
1930 // if there were __TEXT fixups, restore write protection
1931 if ( fTextSegmentWithFixups != NULL ) {
1932 fTextSegmentWithFixups->setPermissions();
1933 sys_icache_invalidate((void*)fTextSegmentWithFixups->getActualLoadAddress(), fTextSegmentWithFixups->getSize());
1934 }
1935
1936 // update stats
1937 fgTotalBindFixups += fDynamicInfo->nextrel;
1938 }
1939
1940 const mach_header* ImageLoaderMachO::machHeader() const
1941 {
1942 return (mach_header*)fMachOData;
1943 }
1944
1945 uintptr_t ImageLoaderMachO::getSlide() const
1946 {
1947 return fSlide;
1948 }
1949
1950 // hmm. maybe this should be up in ImageLoader??
1951 const void* ImageLoaderMachO::getBaseAddress() const
1952 {
1953 Segment* seg = fSegments[0];
1954 return (const void*)seg->getActualLoadAddress();
1955 }
1956
1957 uintptr_t ImageLoaderMachO::bindIndirectSymbol(uintptr_t* ptrToBind, const struct macho_section* sect, const char* symbolName, uintptr_t targetAddr, ImageLoader* targetImage, const LinkContext& context)
1958 {
1959 if ( context.verboseBind ) {
1960 const char* path = NULL;
1961 if ( targetImage != NULL )
1962 path = targetImage->getShortName();
1963 fprintf(stderr, "dyld: bind: %s:%s$%s = %s:%s, *0x%08lx = 0x%08lx\n",
1964 this->getShortName(), symbolName, (((sect->flags & SECTION_TYPE)==S_NON_LAZY_SYMBOL_POINTERS) ? "non_lazy_ptr" : "lazy_ptr"),
1965 path, symbolName, (uintptr_t)ptrToBind, targetAddr);
1966 }
1967 if ( context.bindingHandler != NULL ) {
1968 const char* path = NULL;
1969 if ( targetImage != NULL )
1970 path = targetImage->getShortName();
1971 targetAddr = (uintptr_t)context.bindingHandler(path, symbolName, (void *)targetAddr);
1972 }
1973 #if __i386__
1974 // i386 has special self-modifying stubs that change from "CALL rel32" to "JMP rel32"
1975 if ( ((sect->flags & SECTION_TYPE) == S_SYMBOL_STUBS) && ((sect->flags & S_ATTR_SELF_MODIFYING_CODE) != 0) && (sect->reserved2 == 5) ) {
1976 uint8_t* const jmpTableEntryToPatch = (uint8_t*)ptrToBind;
1977 uint32_t rel32 = targetAddr - (((uint32_t)ptrToBind)+5);
1978 //fprintf(stderr, "rewriting stub at %p\n", jmpTableEntryToPatch);
1979 jmpTableEntryToPatch[0] = 0xE9; // JMP rel32
1980 jmpTableEntryToPatch[1] = rel32 & 0xFF;
1981 jmpTableEntryToPatch[2] = (rel32 >> 8) & 0xFF;
1982 jmpTableEntryToPatch[3] = (rel32 >> 16) & 0xFF;
1983 jmpTableEntryToPatch[4] = (rel32 >> 24) & 0xFF;
1984 }
1985 else
1986 #endif
1987 *ptrToBind = targetAddr;
1988 return targetAddr;
1989 }
1990
1991
1992 uintptr_t ImageLoaderMachO::doBindLazySymbol(uintptr_t* lazyPointer, const LinkContext& context)
1993 {
1994 // scan for all non-lazy-pointer sections
1995 const bool twoLevel = this->usesTwoLevelNameSpace();
1996 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
1997 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
1998 const struct load_command* cmd = cmds;
1999 const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
2000 for (uint32_t i = 0; i < cmd_count; ++i) {
2001 switch (cmd->cmd) {
2002 case LC_SEGMENT_COMMAND:
2003 {
2004 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
2005 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
2006 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
2007 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
2008 const uint8_t type = sect->flags & SECTION_TYPE;
2009 uint32_t symbolIndex = INDIRECT_SYMBOL_LOCAL;
2010 if ( type == S_LAZY_SYMBOL_POINTERS ) {
2011 const uint32_t pointerCount = sect->size / sizeof(uintptr_t);
2012 uintptr_t* const symbolPointers = (uintptr_t*)(sect->addr + fSlide);
2013 if ( (lazyPointer >= symbolPointers) && (lazyPointer < &symbolPointers[pointerCount]) ) {
2014 const uint32_t indirectTableOffset = sect->reserved1;
2015 const uint32_t lazyIndex = lazyPointer - symbolPointers;
2016 symbolIndex = indirectTable[indirectTableOffset + lazyIndex];
2017 }
2018 }
2019 #if __i386__
2020 else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
2021 // 5 bytes stubs on i386 are new "fast stubs"
2022 uint8_t* const jmpTableBase = (uint8_t*)(sect->addr + fSlide);
2023 uint8_t* const jmpTableEnd = jmpTableBase + sect->size;
2024 // initial CALL instruction in jump table leaves pointer to next entry, so back up
2025 uint8_t* const jmpTableEntryToPatch = ((uint8_t*)lazyPointer) - 5;
2026 lazyPointer = (uintptr_t*)jmpTableEntryToPatch;
2027 if ( (jmpTableEntryToPatch >= jmpTableBase) && (jmpTableEntryToPatch < jmpTableEnd) ) {
2028 const uint32_t indirectTableOffset = sect->reserved1;
2029 const uint32_t entryIndex = (jmpTableEntryToPatch - jmpTableBase)/5;
2030 symbolIndex = indirectTable[indirectTableOffset + entryIndex];
2031 }
2032 }
2033 #endif
2034 if ( symbolIndex != INDIRECT_SYMBOL_ABS && symbolIndex != INDIRECT_SYMBOL_LOCAL ) {
2035 const char* symbolName = &fStrings[fSymbolTable[symbolIndex].n_un.n_strx];
2036 ImageLoader* image = NULL;
2037 uintptr_t symbolAddr = this->resolveUndefined(context, &fSymbolTable[symbolIndex], twoLevel, &image);
2038 symbolAddr = this->bindIndirectSymbol(lazyPointer, sect, symbolName, symbolAddr, image, context);
2039 ++fgTotalLazyBindFixups;
2040 return symbolAddr;
2041 }
2042 }
2043 }
2044 break;
2045 }
2046 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
2047 }
2048 throw "lazy pointer not found";
2049 }
2050
2051
2052
2053
2054 void ImageLoaderMachO::doBindIndirectSymbolPointers(const LinkContext& context, BindingLaziness bindness, bool onlyCoalescedSymbols)
2055 {
2056 // scan for all non-lazy-pointer sections
2057 const bool twoLevel = this->usesTwoLevelNameSpace();
2058 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
2059 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
2060 const struct load_command* cmd = cmds;
2061 const uint32_t* const indirectTable = (uint32_t*)&fLinkEditBase[fDynamicInfo->indirectsymoff];
2062 for (uint32_t i = 0; i < cmd_count; ++i) {
2063 switch (cmd->cmd) {
2064 case LC_SEGMENT_COMMAND:
2065 {
2066 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
2067 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
2068 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
2069 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
2070 const uint8_t type = sect->flags & SECTION_TYPE;
2071 uint32_t elementSize = sizeof(uintptr_t);
2072 uint32_t elementCount = sect->size / elementSize;
2073 if ( type == S_NON_LAZY_SYMBOL_POINTERS ) {
2074 if ( (bindness == kLazyOnly) || (bindness == kLazyOnlyNoDependents) )
2075 continue;
2076 }
2077 else if ( type == S_LAZY_SYMBOL_POINTERS ) {
2078 // process each symbol pointer in this section
2079 fgTotalPossibleLazyBindFixups += elementCount;
2080 if ( bindness == kNonLazyOnly )
2081 continue;
2082 }
2083 #if __i386__
2084 else if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
2085 // process each jmp entry in this section
2086 elementCount = sect->size / 5;
2087 elementSize = 5;
2088 fgTotalPossibleLazyBindFixups += elementCount;
2089 if ( bindness == kNonLazyOnly )
2090 continue;
2091 }
2092 #endif
2093 else {
2094 continue;
2095 }
2096 const uint32_t indirectTableOffset = sect->reserved1;
2097 uint8_t* ptrToBind = (uint8_t*)(sect->addr + fSlide);
2098 for (uint32_t j=0; j < elementCount; ++j, ptrToBind += elementSize) {
2099 uint32_t symbolIndex = indirectTable[indirectTableOffset + j];
2100 if ( symbolIndex == INDIRECT_SYMBOL_LOCAL) {
2101 *((uintptr_t*)ptrToBind) += this->fSlide;
2102 }
2103 else if ( symbolIndex == INDIRECT_SYMBOL_ABS) {
2104 // do nothing since already has absolute address
2105 }
2106 else {
2107 const struct macho_nlist* sym = &fSymbolTable[symbolIndex];
2108 if ( symbolIndex == 0 ) {
2109 // This could be rdar://problem/3534709
2110 if ( ((const macho_header*)fMachOData)->filetype == MH_EXECUTE ) {
2111 static bool alreadyWarned = false;
2112 if ( (sym->n_type & N_TYPE) != N_UNDF ) {
2113 // The indirect table parallels the (non)lazy pointer sections. For
2114 // instance, to find info about the fifth lazy pointer you look at the
2115 // fifth entry in the indirect table. (try otool -Iv on a file).
2116 // The entry in the indirect table contains an index into the symbol table.
2117
2118 // The bug in ld caused the entry in the indirect table to be zero
2119 // (instead of a magic value that means a local symbol). So, if the
2120 // symbolIndex == 0, we may be encountering the bug, or 0 may be a valid
2121 // symbol table index. The check I put in place is to see if the zero'th
2122 // symbol table entry is an import entry (usually it is a local symbol
2123 // definition).
2124 if ( context.verboseWarnings && !alreadyWarned ) {
2125 fprintf(stderr, "dyld: malformed executable '%s', skipping indirect symbol to %s\n",
2126 this->getPath(), &fStrings[sym->n_un.n_strx]);
2127 alreadyWarned = true;
2128 }
2129 continue;
2130 }
2131 }
2132 }
2133 ImageLoader *image = NULL;
2134 // if only processing coalesced symbols and this one does not require coalesceing, skip to next
2135 if ( onlyCoalescedSymbols && !symbolRequiresCoalescing(sym) )
2136 continue;
2137 uintptr_t symbolAddr;
2138 symbolAddr = resolveUndefined(context, sym, twoLevel, &image);
2139
2140 // update pointer
2141 symbolAddr = this->bindIndirectSymbol((uintptr_t*)ptrToBind, sect, &fStrings[sym->n_un.n_strx], symbolAddr, image, context);
2142 }
2143 }
2144 // update stats
2145 fgTotalBindFixups += elementCount;
2146 }
2147 }
2148 break;
2149 }
2150 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
2151 }
2152 }
2153
2154 /*
2155 * The address of these symbols are written in to the (__DATA,__dyld) section
2156 * at the following offsets:
2157 * at offset 0 stub_binding_helper_interface
2158 * at offset 4 _dyld_func_lookup
2159 * at offset 8 start_debug_thread
2160 * The 'C' types (if any) for these symbols are ignored here and all are
2161 * declared as longs so the assignment of their address in to the section will
2162 * not require a cast. stub_binding_helper_interface is really a label in the
2163 * assembly code interface for the stub binding. It does not have a meaningful
2164 * 'C' type. _dyld_func_lookup is the routine in dyld_libfuncs.c.
2165 * start_debug_thread is the routine in debug.c.
2166 *
2167 * For ppc the image's stub_binding_binding_helper is read from:
2168 * at offset 20 the image's stub_binding_binding_helper address
2169 * and saved into to the image structure.
2170 */
2171 struct DATAdyld {
2172 void* dyldLazyBinder; // filled in at launch by dyld to point into dyld to &stub_binding_helper_interface
2173 void* dyldFuncLookup; // filled in at launch by dyld to point into dyld to &_dyld_func_lookup
2174 void* startDebugThread; // debugger interface ???
2175 void* debugPort; // debugger interface ???
2176 void* debugThread; // debugger interface ???
2177 void* stubBindHelper; // filled in at static link time to point to stub helper in image
2178 void* coreDebug; // ???
2179 };
2180
2181 // These are defined in dyldStartup.s
2182 extern "C" void stub_binding_helper();
2183 extern "C" bool dyld_func_lookup(const char* name, uintptr_t* address);
2184 extern "C" void fast_stub_binding_helper_interface();
2185
2186
2187 void ImageLoaderMachO::setupLazyPointerHandler(const LinkContext& context)
2188 {
2189 if ( fDATAdyld != NULL ) {
2190 struct DATAdyld* dd = (struct DATAdyld*)(fDATAdyld->addr + fSlide);
2191 if ( fDATAdyld->size > offsetof(DATAdyld, dyldLazyBinder) ) {
2192 if ( dd->dyldLazyBinder != (void*)&stub_binding_helper )
2193 dd->dyldLazyBinder = (void*)&stub_binding_helper;
2194 }
2195 if ( fDATAdyld->size > offsetof(DATAdyld, dyldFuncLookup) ) {
2196 if ( dd->dyldFuncLookup != (void*)&dyld_func_lookup )
2197 dd->dyldFuncLookup = (void*)&dyld_func_lookup;
2198 }
2199 //if ( fDATAdyld->size > offsetof(DATAdyld, startDebugThread) )
2200 // dd->startDebugThread = &start_debug_thread;
2201 #ifdef __ppc__
2202 //if ( fDATAdyld->size > offsetof(DATAdyld, stubBindHelper) )
2203 // save = dd->stubBindHelper;
2204 #endif
2205 }
2206 #if __i386__
2207 if ( ! this->usablePrebinding(context) || !this->usesTwoLevelNameSpace() ) {
2208 // reset all "fast" stubs
2209 const uint32_t cmd_count = ((macho_header*)fMachOData)->ncmds;
2210 const struct load_command* const cmds = (struct load_command*)&fMachOData[sizeof(macho_header)];
2211 const struct load_command* cmd = cmds;
2212 for (uint32_t i = 0; i < cmd_count; ++i) {
2213 switch (cmd->cmd) {
2214 case LC_SEGMENT_COMMAND:
2215 {
2216 const struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
2217 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
2218 const struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
2219 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
2220 const uint8_t type = sect->flags & SECTION_TYPE;
2221 if ( (type == S_SYMBOL_STUBS) && (sect->flags & S_ATTR_SELF_MODIFYING_CODE) && (sect->reserved2 == 5) ) {
2222 // reset each jmp entry in this section
2223 uint8_t* start = (uint8_t*)(sect->addr + this->fSlide);
2224 uint8_t* end = start + sect->size;
2225 uintptr_t dyldHandler = (uintptr_t)&fast_stub_binding_helper_interface;
2226 for (uint8_t* entry = start; entry < end; entry += 5) {
2227 uint32_t rel32 = dyldHandler - (((uint32_t)entry)+5);
2228 entry[0] = 0xE8; // CALL rel32
2229 entry[1] = rel32 & 0xFF;
2230 entry[2] = (rel32 >> 8) & 0xFF;
2231 entry[3] = (rel32 >> 16) & 0xFF;
2232 entry[4] = (rel32 >> 24) & 0xFF;
2233 }
2234 }
2235 }
2236 }
2237 }
2238 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
2239 }
2240 }
2241 #endif
2242 }
2243
2244 bool ImageLoaderMachO::usablePrebinding(const LinkContext& context) const
2245 {
2246 // if prebound and loaded at prebound address, and all libraries are same as when this was prebound, then no need to bind
2247 if ( this->isPrebindable() && this->allDependentLibrariesAsWhenPreBound() && (this->getSlide() == 0) ) {
2248 // allow environment variables to disable prebinding
2249 if ( context.bindFlat )
2250 return false;
2251 switch ( context.prebindUsage ) {
2252 case kUseAllPrebinding:
2253 return true;
2254 case kUseSplitSegPrebinding:
2255 return this->fIsSplitSeg;
2256 case kUseAllButAppPredbinding:
2257 return (this != context.mainExecutable);
2258 case kUseNoPrebinding:
2259 return false;
2260 }
2261 }
2262 return false;
2263 }
2264
2265 void ImageLoaderMachO::doBind(const LinkContext& context, BindingLaziness bindness)
2266 {
2267 // set dyld entry points in image
2268 this->setupLazyPointerHandler(context);
2269
2270 // if prebound and loaded at prebound address, and all libraries are same as when this was prebound, then no need to bind
2271 // note: flat-namespace binaries need to be imports rebound (even if correctly prebound)
2272 if ( this->usablePrebinding(context) && this->usesTwoLevelNameSpace() ) {
2273 // if image has coalesced symbols, then these need to be rebound, unless this is the only image with weak symbols
2274 if ( this->needsCoalescing() && (fgCountOfImagesWithWeakExports > 1) ) {
2275 this->doBindExternalRelocations(context, true);
2276 this->doBindIndirectSymbolPointers(context, kLazyAndNonLazy, true);
2277 }
2278 // skip binding because prebound and prebinding not disabled
2279 return;
2280 }
2281
2282 // values bound by name are stored two different ways in mach-o
2283 switch (bindness) {
2284 case kNonLazyOnly:
2285 case kLazyAndNonLazy:
2286 // external relocations are used for data initialized to external symbols
2287 this->doBindExternalRelocations(context, false);
2288 break;
2289 case kLazyOnly:
2290 case kLazyOnlyNoDependents:
2291 break;
2292 }
2293 // "indirect symbols" are used for code references to external symbols
2294 this->doBindIndirectSymbolPointers(context, bindness, false);
2295 }
2296
2297
2298
2299 void ImageLoaderMachO::doImageInit(const LinkContext& context)
2300 {
2301 if ( fDashInit != NULL ) {
2302 Initializer func = (Initializer)(fDashInit->init_address + fSlide);
2303 if ( context.verboseInit )
2304 fprintf(stderr, "dyld: calling -init function 0x%p in %s\n", func, this->getPath());
2305 func(context.argc, context.argv, context.envp, context.apple);
2306 }
2307 }
2308
2309 void ImageLoaderMachO::doModInitFunctions(const LinkContext& context)
2310 {
2311 if ( fModInitSection != NULL ) {
2312 Initializer* inits = (Initializer*)(fModInitSection->addr + fSlide);
2313 const uint32_t count = fModInitSection->size / sizeof(uintptr_t);
2314 for (uint32_t i=0; i < count; ++i) {
2315 Initializer func = inits[i];
2316 if ( context.verboseInit )
2317 fprintf(stderr, "dyld: calling initializer function %p in %s\n", func, this->getPath());
2318 func(context.argc, context.argv, context.envp, context.apple);
2319 }
2320 }
2321 }
2322
2323
2324 void ImageLoaderMachO::doInitialization(const LinkContext& context)
2325 {
2326 // mach-o has -init and static initializers
2327 doImageInit(context);
2328 doModInitFunctions(context);
2329 }
2330
2331 bool ImageLoaderMachO::needsInitialization()
2332 {
2333 return ( (fDashInit != NULL) || (fModInitSection != NULL) );
2334 }
2335
2336
2337 bool ImageLoaderMachO::needsTermination()
2338 {
2339 return ( fModTermSection != NULL );
2340 }
2341
2342 bool ImageLoaderMachO::hasImageNotification()
2343 {
2344 return ( fImageNotifySection != NULL );
2345 }
2346
2347
2348 void ImageLoaderMachO::doTermination(const LinkContext& context)
2349 {
2350 if ( fModTermSection != NULL ) {
2351 Terminator* terms = (Terminator*)(fModTermSection->addr + fSlide);
2352 const uint32_t count = fModTermSection->size / sizeof(uintptr_t);
2353 for (uint32_t i=count; i > 0; --i) {
2354 Terminator func = terms[i-1];
2355 if ( context.verboseInit )
2356 fprintf(stderr, "dyld: calling terminaton function %p in %s\n", func, this->getPath());
2357 func();
2358 }
2359 }
2360 }
2361
2362 void ImageLoaderMachO::doNotification(enum dyld_image_mode mode, uint32_t infoCount, const struct dyld_image_info info[])
2363 {
2364 if ( fImageNotifySection != NULL ) {
2365 dyld_image_notifier* notes = (dyld_image_notifier*)(fImageNotifySection->addr + fSlide);
2366 const uint32_t count = fImageNotifySection->size / sizeof(uintptr_t);
2367 for (uint32_t i=count; i > 0; --i) {
2368 dyld_image_notifier func = notes[i-1];
2369 func(mode, infoCount, info);
2370 }
2371 }
2372 }
2373
2374 void ImageLoaderMachO::printStatistics(unsigned int imageCount)
2375 {
2376 ImageLoader::printStatistics(imageCount);
2377 fprintf(stderr, "total hinted binary tree searches: %d\n", fgHintedBinaryTreeSearchs);
2378 fprintf(stderr, "total unhinted binary tree searches: %d\n", fgUnhintedBinaryTreeSearchs);
2379 fprintf(stderr, "total images with weak exports: %d\n", fgCountOfImagesWithWeakExports);
2380
2381 #if LINKEDIT_USAGE_DEBUG
2382 fprintf(stderr, "linkedit pages accessed (%lu):\n", sLinkEditPageBuckets.size());
2383 #endif
2384 }
2385
2386 void ImageLoaderMachO::doPrebinding(const LinkContext& context, time_t timestamp, uint8_t* fileToPrebind)
2387 {
2388 // update __DATA segment
2389 this->applyPrebindingToDATA(fileToPrebind);
2390
2391 // update load commands
2392 this->applyPrebindingToLoadCommands(context, fileToPrebind, timestamp);
2393
2394 // update symbol table
2395 this->applyPrebindingToLinkEdit(context, fileToPrebind);
2396 }
2397
2398 void ImageLoaderMachO::applyPrebindingToDATA(uint8_t* fileToPrebind)
2399 {
2400 const unsigned int segmentCount = fSegments.size();
2401 for(unsigned int i=0; i < segmentCount; ++i) {
2402 SegmentMachO* seg = (SegmentMachO*)fSegments[i];
2403 if ( seg->writeable() ) {
2404 memcpy(&fileToPrebind[seg->fFileOffset], (void*)seg->getActualLoadAddress(), seg->fFileSize);
2405 }
2406 }
2407 }
2408
2409 void ImageLoaderMachO::applyPrebindingToLoadCommands(const LinkContext& context, uint8_t* fileToPrebind, time_t timestamp)
2410 {
2411 macho_header* mh = (macho_header*)fileToPrebind;
2412 const uint32_t cmd_count = mh->ncmds;
2413 const struct load_command* const cmds = (struct load_command*)&fileToPrebind[sizeof(macho_header)];
2414 const struct load_command* cmd = cmds;
2415 for (uint32_t i = 0; i < cmd_count; ++i) {
2416 switch (cmd->cmd) {
2417 case LC_LOAD_DYLIB:
2418 case LC_LOAD_WEAK_DYLIB:
2419 {
2420 // update each dylib load command with the timestamp of the target dylib
2421 struct dylib_command* dylib = (struct dylib_command*)cmd;
2422 const char* name = (char*)cmd + dylib->dylib.name.offset;
2423 for (const DependentLibrary* dl=fLibraries; dl < &fLibraries[fLibrariesCount]; dl++) {
2424 if (strcmp(dl->name, name) == 0 ) {
2425 // found matching DependentLibrary for this load command
2426 ImageLoaderMachO* targetImage = (ImageLoaderMachO*)(dl->image); // !!! assume only mach-o images are prebound
2427 if ( ! targetImage->isPrebindable() )
2428 throw "dependent dylib is not prebound";
2429 // if the target is currently being re-prebound then its timestamp will be the same as this one
2430 if ( ! targetImage->usablePrebinding(context) ) {
2431 dylib->dylib.timestamp = timestamp;
2432 }
2433 else {
2434 // otherwise dependent library is already correctly prebound, so use its checksum
2435 dylib->dylib.timestamp = targetImage->doGetLibraryInfo().checksum;
2436 }
2437 break;
2438 }
2439 }
2440 }
2441 break;
2442 case LC_ID_DYLIB:
2443 {
2444 // update the ID of this library with the new timestamp
2445 struct dylib_command* dylib = (struct dylib_command*)cmd;
2446 dylib->dylib.timestamp = timestamp;
2447 }
2448 break;
2449 case LC_SEGMENT_COMMAND:
2450 // if dylib was rebased, update segment commands
2451 if ( fSlide != 0 ) {
2452 struct macho_segment_command* seg = (struct macho_segment_command*)cmd;
2453 seg->vmaddr += fSlide;
2454 struct macho_section* const sectionsStart = (struct macho_section*)((char*)seg + sizeof(struct macho_segment_command));
2455 struct macho_section* const sectionsEnd = &sectionsStart[seg->nsects];
2456 for (struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
2457 sect->addr += fSlide;
2458 }
2459 }
2460 break;
2461 case LC_ROUTINES_COMMAND:
2462 // if dylib was rebased, update -init command
2463 if ( fSlide != 0 ) {
2464 struct macho_routines_command* routines = (struct macho_routines_command*)cmd;
2465 routines->init_address += fSlide;
2466 }
2467 break;
2468 }
2469 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
2470 }
2471 }
2472
2473 void ImageLoaderMachO::applyPrebindingToLinkEdit(const LinkContext& context, uint8_t* fileToPrebind)
2474 {
2475 // In prebound images, the n_value of the symbol table entry for is the prebound address
2476 // This is needed when prebinding can't be used, to back solve for any possible addend in non-lazy pointers
2477 const char* stringPool = NULL;
2478 struct macho_nlist* symbolTable = NULL;
2479 const struct dysymtab_command* dysymtab = NULL;
2480
2481 // get symbol table info
2482 macho_header* mh = (macho_header*)fileToPrebind;
2483 const uint32_t cmd_count = mh->ncmds;
2484 const struct load_command* const cmds = (struct load_command*)&fileToPrebind[sizeof(macho_header)];
2485 const struct load_command* cmd = cmds;
2486 for (uint32_t i = 0; i < cmd_count; ++i) {
2487 switch (cmd->cmd) {
2488 case LC_SYMTAB:
2489 {
2490 const struct symtab_command* symtab = (struct symtab_command*)cmd;
2491 stringPool = (const char*)&fileToPrebind[symtab->stroff];
2492 symbolTable = (struct macho_nlist*)(&fileToPrebind[symtab->symoff]);
2493 }
2494 break;
2495 case LC_DYSYMTAB:
2496 dysymtab = (struct dysymtab_command*)cmd;
2497 break;
2498 }
2499 cmd = (const struct load_command*)(((char*)cmd)+cmd->cmdsize);
2500 }
2501
2502 // walk all imports and re-resolve their n_value (needed incase prebinding is invalid)
2503 struct macho_nlist* lastImport = &symbolTable[dysymtab->iundefsym+dysymtab->nundefsym];
2504 for (struct macho_nlist* entry = &symbolTable[dysymtab->iundefsym]; entry < lastImport; ++entry) {
2505 ImageLoader* dummy;
2506 entry->n_value = this->resolveUndefined(context, entry, this->usesTwoLevelNameSpace(), &dummy);
2507 }
2508
2509 // walk all exports and slide their n_value
2510 struct macho_nlist* lastExport = &symbolTable[dysymtab->iextdefsym+dysymtab->nextdefsym];
2511 for (struct macho_nlist* entry = &symbolTable[dysymtab->iextdefsym]; entry < lastExport; ++entry) {
2512 if ( (entry->n_type & N_TYPE) == N_SECT )
2513 entry->n_value += fSlide;
2514 }
2515
2516 // walk all local symbols and slide their n_value
2517 struct macho_nlist* lastLocal = &symbolTable[dysymtab->ilocalsym+dysymtab->nlocalsym];
2518 for (struct macho_nlist* entry = &symbolTable[dysymtab->ilocalsym]; entry < lastLocal; ++entry) {
2519 if ( entry->n_sect != NO_SECT )
2520 entry->n_value += fSlide;
2521 }
2522
2523 // walk all local relocations and reset every PPC_RELOC_PB_LA_PTR r_value
2524 relocation_info* const relocsStart = (struct relocation_info*)(&fileToPrebind[dysymtab->locreloff]);
2525 relocation_info* const relocsEnd = &relocsStart[dysymtab->nlocrel];
2526 for (relocation_info* reloc=relocsStart; reloc < relocsEnd; ++reloc) {
2527 if ( (reloc->r_address & R_SCATTERED) != 0 ) {
2528 struct scattered_relocation_info* sreloc = (struct scattered_relocation_info*)reloc;
2529 if (sreloc->r_length == RELOC_SIZE) {
2530 switch(sreloc->r_type) {
2531 #if __ppc__ || __ppc64__
2532 case PPC_RELOC_PB_LA_PTR:
2533 #elif __i386__
2534 case GENERIC_RELOC_PB_LA_PTR:
2535 #else
2536 #error unknown architecture
2537 #endif
2538 sreloc->r_value += fSlide;
2539 break;
2540 }
2541 }
2542 }
2543 }
2544
2545 // if multi-module, fix up objc_addr (10.4 and later runtime does not use this, but we want to keep file checksum consistent)
2546 if ( dysymtab->nmodtab != 0 ) {
2547 dylib_module* const modulesStart = (struct dylib_module*)(&fileToPrebind[dysymtab->modtaboff]);
2548 dylib_module* const modulesEnd = &modulesStart[dysymtab->nmodtab];
2549 for (dylib_module* module=modulesStart; module < modulesEnd; ++module) {
2550 if ( module->objc_module_info_size != 0 ) {
2551 module->objc_module_info_addr += fSlide;
2552 }
2553 }
2554 }
2555 }
2556
2557 // file on disk has been reprebound, but we are still mapped to old file
2558 void ImageLoaderMachO::prebindUnmap(const LinkContext& context)
2559 {
2560 // this removes all mappings to the old file, so the kernel will unlink (delete) it.
2561 // We need to leave the load commands and __LINKEDIT in place
2562 for (std::vector<class Segment*>::iterator it=fSegments.begin(); it != fSegments.end(); ++it) {
2563 void* segmentAddress = (void*)((*it)->getActualLoadAddress());
2564 uintptr_t segmentSize = (*it)->getSize();
2565 //fprintf(stderr, "unmapping segment %s at %p for %s\n", (*it)->getName(), segmentAddress, this->getPath());
2566 // save load commands at beginning of __TEXT segment
2567 if ( segmentAddress == fMachOData ) {
2568 // typically load commands are one or two pages in size, so ok to alloc on stack
2569 uint32_t loadCmdSize = sizeof(macho_header) + ((macho_header*)fMachOData)->sizeofcmds;
2570 uint32_t loadCmdPages = (loadCmdSize+4095) & (-4096);
2571 uint8_t loadcommands[loadCmdPages];
2572 memcpy(loadcommands, fMachOData, loadCmdPages);
2573 // unmap whole __TEXT segment
2574 munmap((void*)(fMachOData), segmentSize);
2575 // allocate and copy back mach_header and load commands
2576 vm_address_t addr = (vm_address_t)fMachOData;
2577 int r2 = vm_allocate(mach_task_self(), &addr, loadCmdPages, false /*at this address*/);
2578 if ( r2 != 0 )
2579 fprintf(stderr, "prebindUnmap() vm_allocate for __TEXT %d failed\n", loadCmdPages);
2580 memcpy((void*)fMachOData, loadcommands, loadCmdPages);
2581 //fprintf(stderr, "copying back load commands to %p size=%u for %s\n", segmentAddress, loadCmdPages, this->getPath());
2582 }
2583 else if ( strcmp((*it)->getName(), "__LINKEDIT") == 0 ) {
2584 uint32_t linkEditSize = segmentSize;
2585 uint32_t linkEditPages = (linkEditSize+4095) & (-4096);
2586 void* linkEditTmp = malloc(linkEditPages);
2587 memcpy(linkEditTmp, segmentAddress, linkEditPages);
2588 // unmap whole __LINKEDIT segment
2589 munmap(segmentAddress, segmentSize);
2590 vm_address_t addr = (vm_address_t)segmentAddress;
2591 int r2 = vm_allocate(mach_task_self(), &addr, linkEditPages, false /*at this address*/);
2592 if ( r2 != 0 )
2593 fprintf(stderr, "prebindUnmap() vm_allocate for __LINKEDIT %d failed\n", linkEditPages);
2594 memcpy(segmentAddress, linkEditTmp, linkEditPages);
2595 //fprintf(stderr, "copying back __LINKEDIT to %p size=%u for %s\n", segmentAddress, linkEditPages, this->getPath());
2596 free(linkEditTmp);
2597 }
2598 else {
2599 // unmap any other segment
2600 munmap((void*)(segmentAddress), (*it)->getSize());
2601 }
2602 }
2603 }
2604
2605
2606
2607 SegmentMachO::SegmentMachO(const struct macho_segment_command* cmd, ImageLoaderMachO* image, const uint8_t* fileData)
2608 : fImage(image), fSize(cmd->vmsize), fFileSize(cmd->filesize), fFileOffset(cmd->fileoff), fPreferredLoadAddress(cmd->vmaddr),
2609 fVMProtection(cmd->initprot), fHasFixUps(false), fUnMapOnDestruction(false)
2610 {
2611 strncpy(fName, cmd->segname, 16);
2612 fName[16] = '\0';
2613 // scan sections for fix-up bit
2614 const struct macho_section* const sectionsStart = (struct macho_section*)((char*)cmd + sizeof(struct macho_segment_command));
2615 const struct macho_section* const sectionsEnd = &sectionsStart[cmd->nsects];
2616 for (const struct macho_section* sect=sectionsStart; sect < sectionsEnd; ++sect) {
2617 if ( (sect->flags & (S_ATTR_EXT_RELOC | S_ATTR_LOC_RELOC)) != 0 )
2618 fHasFixUps = true;
2619 }
2620 }
2621
2622 SegmentMachO::~SegmentMachO()
2623 {
2624 if ( fUnMapOnDestruction ) {
2625 //fprintf(stderr, "unmapping segment %s at 0x%08lX\n", getName(), getActualLoadAddress());
2626 munmap((void*)(this->getActualLoadAddress()), this->getSize());
2627 }
2628 }
2629
2630 const ImageLoader* SegmentMachO::getImage()
2631 {
2632 return fImage;
2633 }
2634
2635 const char* SegmentMachO::getName()
2636 {
2637 return fName;
2638 }
2639
2640 uintptr_t SegmentMachO::getSize()
2641 {
2642 return fSize;
2643 }
2644
2645 uintptr_t SegmentMachO::getFileSize()
2646 {
2647 return fFileSize;
2648 }
2649
2650 uintptr_t SegmentMachO::getFileOffset()
2651 {
2652 return fFileOffset;
2653 }
2654
2655 bool SegmentMachO::readable()
2656 {
2657 return ( (fVMProtection & VM_PROT_READ) != 0);
2658 }
2659
2660 bool SegmentMachO::writeable()
2661 {
2662 return ((fVMProtection & VM_PROT_WRITE) != 0);
2663 }
2664
2665 bool SegmentMachO::executable()
2666 {
2667 return ((fVMProtection & VM_PROT_EXECUTE) != 0);
2668 }
2669
2670 bool SegmentMachO::unaccessible()
2671 {
2672 return (fVMProtection == 0);
2673 }
2674
2675 bool SegmentMachO::hasFixUps()
2676 {
2677 return fHasFixUps;
2678 }
2679
2680 uintptr_t SegmentMachO::getActualLoadAddress()
2681 {
2682 return fPreferredLoadAddress + fImage->fSlide;
2683 }
2684
2685 uintptr_t SegmentMachO::getPreferredLoadAddress()
2686 {
2687 return fPreferredLoadAddress;
2688 }
2689
2690 bool SegmentMachO::hasPreferredLoadAddress()
2691 {
2692 return (fPreferredLoadAddress != 0);
2693 }
2694
2695 void SegmentMachO::setUnMapWhenDestructed(bool unmap)
2696 {
2697 fUnMapOnDestruction = unmap;
2698 }
2699
2700 static uint32_t *buildCRCTable(void)
2701 {
2702 uint32_t *table = new uint32_t[256];
2703 uint32_t p = 0xedb88320UL; // standard CRC-32 polynomial
2704
2705 for (unsigned int i = 0; i < 256; i++) {
2706 uint32_t c = i;
2707 for (unsigned int j = 0; j < 8; j++) {
2708 if ( c & 1 ) c = p ^ (c >> 1);
2709 else c = c >> 1;
2710 }
2711 table[i] = c;
2712 }
2713
2714 return table;
2715 }
2716
2717 uint32_t SegmentMachO::crc32()
2718 {
2719 if ( !readable() ) return 0;
2720
2721 static uint32_t *crcTable = NULL;
2722 if ( !crcTable ) crcTable = buildCRCTable();
2723
2724 uint32_t crc = ~(uint32_t)0;
2725 uint8_t *p = (uint8_t *)getActualLoadAddress();
2726 uint8_t *end = p + getSize();
2727 while ( p < end ) {
2728 crc = crcTable[(crc & 0xff) ^ (*p++)] ^ (crc >> 8);
2729 }
2730 return crc ^ ~(uint32_t)0;
2731 }
2732
2733
2734
2735
2736