src/dyld_process_info.cpp

   1 /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*-
   2  *
   3  * Copyright (c) 2016 Apple Inc. All rights reserved.
   4  *
   5  * @APPLE_LICENSE_HEADER_START@
   6  *
   7  * This file contains Original Code and/or Modifications of Original Code
   8  * as defined in and that are subject to the Apple Public Source License
   9  * Version 2.0 (the 'License'). You may not use this file except in
  10  * compliance with the License. Please obtain a copy of the License at
  11  * http://www.opensource.apple.com/apsl/ and read it before using this
  12  * file.
  13  *
  14  * The Original Code and all software distributed under the License are
  15  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  16  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  17  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  19  * Please see the License for the specific language governing rights and
  20  * limitations under the License.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <limits.h>
  28 #include <stdio.h>
  29 #include <libproc.h>
  30 #include <sys/param.h>
  31 #include <mach/shared_region.h>
  32 #include <mach/mach_vm.h>
  33 #include <mach/vm_region.h>
  34 #include <libkern/OSAtomic.h>
  35
  36 #include "dyld_process_info.h"
  37 #include "dyld_process_info_internal.h"
  38 #include "dyld_images.h"
  39 #include "dyld_priv.h"
  40
  41 // this was in dyld_priv.h but it is no longer exported
  42 extern "C" {
  43     const struct dyld_all_image_infos* _dyld_get_all_image_infos();
  44 }
  45
  46 namespace {
  47
  48 void withRemoteBuffer(task_t task, vm_address_t remote_address, size_t remote_size, bool allow_truncation, kern_return_t *kr, void (^block)(void *buffer)) {
  49     kern_return_t r = KERN_SUCCESS;
  50     mach_vm_address_t local_address = 0;
  51     mach_vm_address_t local_size = remote_size;
  52     while (1) {
  53         vm_prot_t cur_protection, max_protection;
  54         r = mach_vm_remap(mach_task_self(),
  55                             &local_address,
  56                             local_size,
  57                             0,  // mask
  58                             VM_FLAGS_ANYWHERE | VM_FLAGS_RETURN_DATA_ADDR | VM_FLAGS_RESILIENT_CODESIGN,
  59                             task,
  60                             remote_address,
  61                             TRUE,  // Copy semantics: changes to this memory by the target process will not be visible in this process
  62                             &cur_protection,
  63                             &max_protection,
  64                             VM_INHERIT_DEFAULT);
  65         //Do this here to allow chaining of multiple embedded blocks with a single error out;
  66         if (kr != NULL) {
  67             *kr = r;
  68         }
  69         if (r == KERN_SUCCESS) {
  70             // We got someting, call the block and then exit
  71             block(reinterpret_cast<void *>(local_address));
  72             vm_deallocate(mach_task_self(), local_address, local_size);
  73             break;
  74         }
  75         if (!allow_truncation) {
  76             break;
  77         }
  78         // We did not get something, but we are allowed to truncate and try again
  79         uint64_t trunc_size = ((remote_address + local_size - 1) & PAGE_MASK) + 1;
  80         if (local_size <= trunc_size) {
  81             //Even if we truncate it will be in the same page, time to accept defeat
  82             break;
  83         } else {
  84             local_size -= trunc_size;
  85         }
  86     }
  87 }
  88
  89 template<typename T>
  90 void withRemoteObject(task_t task, vm_address_t remote_address, kern_return_t *kr, void (^block)(T t))
  91 {
  92     withRemoteBuffer(task, remote_address, sizeof(T), false, kr, ^(void *buffer) {
  93         block(*reinterpret_cast<T *>(buffer));
  94     });
  95 }
  96 };
  97
  98 //
  99 // Opaque object returned by _dyld_process_info_create()
 100 //
 101
 102 struct __attribute__((visibility("hidden"))) dyld_process_info_base {
 103     static dyld_process_info_base* make(task_t task, const dyld_all_image_infos_64& allImageInfo, const dyld_image_info_64 imageArray[], kern_return_t* kr);
 104     static dyld_process_info_base* makeSuspended(task_t task, kern_return_t* kr);
 105
 106     uint32_t&                   retainCount() const { return _retainCount; }
 107     dyld_process_cache_info*    cacheInfo() const { return (dyld_process_cache_info*)(((char*)this) + _cacheInfoOffset); }
 108     dyld_process_state_info*    stateInfo() const { return (dyld_process_state_info*)(((char*)this) + _stateInfoOffset); }
 109     void                        forEachImage(void (^callback)(uint64_t machHeaderAddress, const uuid_t uuid, const char* path)) const;
 110     void                        forEachSegment(uint64_t machHeaderAddress, void (^callback)(uint64_t segmentAddress, uint64_t segmentSize, const char* segmentName)) const;
 111
 112 private:
 113     struct ImageInfo {
 114         uuid_t                  uuid;
 115         uint64_t                loadAddress;
 116         const char*             path;
 117         uint32_t                segmentStartIndex;
 118         uint32_t                segmentsCount;
 119     };
 120
 121     struct SegmentInfo {
 122         const char*             name;
 123         uint64_t                addr;
 124         uint64_t                size;
 125     };
 126
 127                                 dyld_process_info_base(unsigned imageCount, size_t totalSize);
 128     void*                       operator new (size_t, void* buf) { return buf; }
 129
 130     static bool                 inCache(uint64_t addr) { return (addr > SHARED_REGION_BASE) && (addr < SHARED_REGION_BASE+SHARED_REGION_SIZE); }
 131     kern_return_t               addImage(task_t task, bool sameCacheAsThisProcess, uint64_t imageAddress, uint64_t imagePath, const char* imagePathLocal);
 132     kern_return_t               addDyldImage(task_t task, uint64_t dyldAddress, uint64_t dyldPathAddress, const char* localPath);
 133
 134     bool                        invalid() { return ((char*)_stringRevBumpPtr < (char*)_curSegment); }
 135     const char*                 copyPath(task_t task, uint64_t pathAddr, kern_return_t* kr);
 136     const char*                 addString(const char*);
 137     const char*                 copySegmentName(const char*);
 138
 139     void                        addInfoFromLoadCommands(const mach_header* mh, uint64_t addressInTask, size_t size);
 140
 141     void                        inspectLocalImageLoadCommands(uint64_t imageAddress, void* func);
 142     kern_return_t               inspectRemoteImageLoadCommands(task_t task, uint64_t imageAddress, void* func);
 143
 144     mutable uint32_t            _retainCount;
 145     const uint32_t              _cacheInfoOffset;
 146     const uint32_t              _stateInfoOffset;
 147     const uint32_t              _imageInfosOffset;
 148     const uint32_t              _segmentInfosOffset;
 149     ImageInfo* const            _firstImage;
 150     ImageInfo*                  _curImage;
 151     SegmentInfo* const          _firstSegment;
 152     SegmentInfo*                _curSegment;
 153     uint32_t                    _curSegmentIndex;
 154     char*                       _stringRevBumpPtr;
 155
 156     // dyld_process_cache_info  cacheInfo;
 157     // dyld_process_state_info  stateInfo;
 158     // ImageInfo                images[];
 159     // SegmentInfo              segments[];
 160     // char                     stringPool[]
 161 };
 162
 163 dyld_process_info_base::dyld_process_info_base(unsigned imageCount, size_t totalSize)
 164  :  _retainCount(1), _cacheInfoOffset(sizeof(dyld_process_info_base)),
 165     _stateInfoOffset(sizeof(dyld_process_info_base) + sizeof(dyld_process_cache_info)),
 166     _imageInfosOffset(sizeof(dyld_process_info_base) + sizeof(dyld_process_cache_info) + sizeof(dyld_process_state_info)),
 167     _segmentInfosOffset(sizeof(dyld_process_info_base) + sizeof(dyld_process_cache_info) + sizeof(dyld_process_state_info) + imageCount*sizeof(ImageInfo)),
 168     _firstImage((ImageInfo*)(((uint8_t*)this) + _imageInfosOffset)),
 169     _curImage((ImageInfo*)(((uint8_t*)this) + _imageInfosOffset)),
 170     _firstSegment((SegmentInfo*)(((uint8_t*)this) + _segmentInfosOffset)),
 171     _curSegment((SegmentInfo*)(((uint8_t*)this) + _segmentInfosOffset)),
 172     _curSegmentIndex(0),
 173     _stringRevBumpPtr((char*)(this)+totalSize)
 174 {
 175 }
 176
 177
 178 dyld_process_info_base* dyld_process_info_base::make(task_t task, const dyld_all_image_infos_64& allImageInfo, const dyld_image_info_64 imageArray[], kern_return_t* kr)
 179 {
 180     // figure out how many path strings will need to be copied and their size
 181     const dyld_all_image_infos* myInfo = _dyld_get_all_image_infos();
 182     bool sameCacheAsThisProcess = !allImageInfo.processDetachedFromSharedRegion
 183                                     && !myInfo->processDetachedFromSharedRegion
 184                                     && ((memcmp(myInfo->sharedCacheUUID, allImageInfo.sharedCacheUUID, 16) == 0)
 185                                     && (myInfo->sharedCacheSlide == allImageInfo.sharedCacheSlide));
 186     unsigned countOfPathsNeedingCopying = 0;
 187     if ( sameCacheAsThisProcess ) {
 188         for (int i=0; i < allImageInfo.infoArrayCount; ++i) {
 189             if ( !inCache(imageArray[i].imageFilePath) )
 190                 ++countOfPathsNeedingCopying;
 191         }
 192     }
 193     else {
 194         countOfPathsNeedingCopying = allImageInfo.infoArrayCount+1;
 195     }
 196     unsigned imageCountWithDyld = allImageInfo.infoArrayCount+1;
 197
 198     // allocate result object
 199     size_t allocationSize =   sizeof(dyld_process_info_base)
 200                             + sizeof(dyld_process_cache_info)
 201                             + sizeof(dyld_process_state_info)
 202                             + sizeof(ImageInfo)*(imageCountWithDyld)
 203                             + sizeof(SegmentInfo)*imageCountWithDyld*5
 204                             + countOfPathsNeedingCopying*PATH_MAX;
 205     void* storage = malloc(allocationSize);
 206     dyld_process_info_base* obj =  new (storage) dyld_process_info_base(imageCountWithDyld, allocationSize); // placement new()
 207
 208     // fill in base info
 209     dyld_process_cache_info* cacheInfo = obj->cacheInfo();
 210     memcpy(cacheInfo->cacheUUID, allImageInfo.sharedCacheUUID, 16);
 211     cacheInfo->cacheBaseAddress    = allImageInfo.sharedCacheBaseAddress;
 212     cacheInfo->privateCache        = allImageInfo.processDetachedFromSharedRegion;
 213     // if no cache is used, allImageInfo has all zeros for cache UUID
 214     cacheInfo->noCache = true;
 215     for (int i=0; i < 16; ++i) {
 216         if ( cacheInfo->cacheUUID[i] != 0 ) {
 217             cacheInfo->noCache = false;
 218         }
 219     }
 220
 221     dyld_process_state_info* stateInfo = obj->stateInfo();
 222     stateInfo->timestamp           = allImageInfo.infoArrayChangeTimestamp;
 223     stateInfo->imageCount          = imageCountWithDyld;
 224     stateInfo->initialImageCount   = (uint32_t)(allImageInfo.initialImageCount+1);
 225     if ( allImageInfo.infoArray != 0 )
 226         stateInfo->dyldState = dyld_process_state_dyld_initialized;
 227     if ( allImageInfo.libSystemInitialized != 0 ) {
 228         stateInfo->dyldState = dyld_process_state_libSystem_initialized;
 229         if ( allImageInfo.initialImageCount != allImageInfo.infoArrayCount )
 230             stateInfo->dyldState = dyld_process_state_program_running;
 231     }
 232     if ( allImageInfo.errorMessage != 0 )
 233         stateInfo->dyldState = allImageInfo.terminationFlags ? dyld_process_state_terminated_before_inits : dyld_process_state_dyld_terminated;
 234
 235     // fill in info for dyld
 236     if ( allImageInfo.dyldPath != 0 ) {
 237         if ( kern_return_t r = obj->addDyldImage(task, allImageInfo.dyldImageLoadAddress, allImageInfo.dyldPath, NULL) ) {
 238             if ( kr != NULL )
 239                 *kr = r;
 240             goto fail;
 241         }
 242     }
 243
 244     // fill in info for each image
 245     for (uint32_t i=0; i < allImageInfo.infoArrayCount; ++i) {
 246         if ( kern_return_t r = obj->addImage(task, sameCacheAsThisProcess, imageArray[i].imageLoadAddress, imageArray[i].imageFilePath, NULL) ) {
 247            if ( kr != NULL )
 248                 *kr = r;
 249             goto fail;
 250         }
 251     }
 252
 253     // sanity check internal data did not overflow
 254     if ( obj->invalid() )
 255         goto fail;
 256
 257     return obj;
 258
 259 fail:
 260     free(obj);
 261     return NULL;
 262 }
 263
 264 dyld_process_info_base* dyld_process_info_base::makeSuspended(task_t task, kern_return_t* kr)
 265 {
 266     pid_t   pid;
 267     kern_return_t result = pid_for_task(task, &pid);
 268     if ( result != KERN_SUCCESS ) {
 269         if ( kr != NULL )
 270             *kr = result;
 271         return NULL;
 272     }
 273
 274     __block unsigned    imageCount = 0;  // main executable and dyld
 275     __block uint64_t    mainExecutableAddress = 0;
 276     __block uint64_t    dyldAddress = 0;
 277     char                dyldPathBuffer[PATH_MAX+1];
 278     char                mainExecutablePathBuffer[PATH_MAX+1];
 279     __block char *      dyldPath = &dyldPathBuffer[0];
 280     __block char *      mainExecutablePath = &mainExecutablePathBuffer[0];
 281     mach_vm_size_t      size;
 282     for (mach_vm_address_t address = 0; ; address += size) {
 283         vm_region_basic_info_data_64_t  info;
 284         mach_port_t                     objectName;
 285         unsigned int                    infoCount = VM_REGION_BASIC_INFO_COUNT_64;
 286         result = mach_vm_region(task, &address, &size, VM_REGION_BASIC_INFO,
 287                          (vm_region_info_t)&info, &infoCount, &objectName);
 288         if ( result != KERN_SUCCESS )
 289             break;
 290         if ( info.protection != (VM_PROT_READ|VM_PROT_EXECUTE) )
 291             continue;
 292             // read start of vm region to verify it is a mach header
 293             withRemoteObject(task, address, NULL, ^(mach_header_64 mhBuffer){
 294                 if ( (mhBuffer.magic != MH_MAGIC) && (mhBuffer.magic != MH_MAGIC_64) )
 295                     return;
 296                 // now know the region is the start of a mach-o file
 297                 if ( mhBuffer.filetype == MH_EXECUTE ) {
 298                     mainExecutableAddress = address;
 299                     int len = proc_regionfilename(pid, mainExecutableAddress, mainExecutablePath, PATH_MAX);
 300                     if ( len != 0 ) {
 301                         mainExecutablePath[len] = '\0';
 302                     }
 303                     ++imageCount;
 304                 }
 305                 else if ( mhBuffer.filetype == MH_DYLINKER ) {
 306                     dyldAddress = address;
 307                     int len = proc_regionfilename(pid, dyldAddress, dyldPath, PATH_MAX);
 308                     if ( len != 0 ) {
 309                         dyldPath[len] = '\0';
 310                     }
 311                     ++imageCount;
 312                 }
 313             });
 314             //fprintf(stderr, "vm region: addr=0x%llX, size=0x%llX, prot=0x%X\n", (uint64_t)address, (uint64_t)size, info.protection);
 315     }
 316     //fprintf(stderr, "dyld: addr=0x%llX, path=%s\n", dyldAddress, dyldPathBuffer);
 317     //fprintf(stderr, "app:  addr=0x%llX, path=%s\n", mainExecutableAddress, mainExecutablePathBuffer);
 318
 319     // allocate result object
 320     size_t allocationSize =   sizeof(dyld_process_info_base)
 321                             + sizeof(dyld_process_cache_info)
 322                             + sizeof(dyld_process_state_info)
 323                             + sizeof(ImageInfo)*(imageCount)
 324                             + sizeof(SegmentInfo)*imageCount*5
 325                             + imageCount*PATH_MAX;
 326     void* storage = malloc(allocationSize);
 327     dyld_process_info_base* obj =  new (storage) dyld_process_info_base(imageCount, allocationSize); // placement new()
 328
 329     // fill in base info
 330     dyld_process_cache_info* cacheInfo = obj->cacheInfo();
 331     bzero(cacheInfo->cacheUUID, 16);
 332     cacheInfo->cacheBaseAddress    = 0;
 333     cacheInfo->noCache             = true;
 334     cacheInfo->privateCache        = false;
 335
 336     dyld_process_state_info* stateInfo = obj->stateInfo();
 337     stateInfo->timestamp           = 0;
 338     stateInfo->imageCount          = imageCount;
 339     stateInfo->initialImageCount   = imageCount;
 340     stateInfo->dyldState           = dyld_process_state_not_started;
 341
 342     // fill in info for dyld
 343     if ( dyldAddress != 0 ) {
 344         if ( kern_return_t r = obj->addDyldImage(task, dyldAddress, 0, dyldPath) ) {
 345             if ( kr != NULL )
 346                 *kr = r;
 347             free(obj);
 348             return NULL;
 349         }
 350     }
 351
 352     // fill in info for each image
 353     if ( mainExecutableAddress != 0 ) {
 354         if ( kern_return_t r = obj->addImage(task, false, mainExecutableAddress, 0, mainExecutablePath) ) {
 355             if ( kr != NULL )
 356                 *kr = r;
 357             free(obj);
 358             return NULL;
 359         }
 360     }
 361
 362     return obj;
 363 }
 364
 365
 366
 367 const char* dyld_process_info_base::addString(const char* str)
 368 {
 369     size_t len = strlen(str) + 1;
 370     _stringRevBumpPtr -= len;
 371     strcpy(_stringRevBumpPtr, str);
 372     return _stringRevBumpPtr;
 373 }
 374
 375 const char* dyld_process_info_base::copyPath(task_t task, uint64_t stringAddressInTask, kern_return_t* kr)
 376 {
 377     __block const char* retval = NULL;
 378     withRemoteBuffer(task, stringAddressInTask, PATH_MAX+8, true, kr, ^(void *buffer) {
 379         retval = addString(static_cast<const char *>(buffer));
 380     });
 381     return retval;
 382 }
 383
 384 kern_return_t dyld_process_info_base::addImage(task_t task, bool sameCacheAsThisProcess, uint64_t imageAddress, uint64_t imagePath, const char* imagePathLocal)
 385 {
 386     _curImage->loadAddress = imageAddress;
 387     _curImage->segmentStartIndex = _curSegmentIndex;
 388     if ( imagePathLocal != NULL ) {
 389         _curImage->path = addString(imagePathLocal);
 390     }
 391     else if ( sameCacheAsThisProcess && inCache(imagePath) ) {
 392         _curImage->path = (const char*)imagePath;
 393     }
 394     else {
 395         kern_return_t kr;
 396         _curImage->path = copyPath(task, imagePath, &kr);
 397         if ( kr )
 398             return kr;
 399     }
 400     if ( sameCacheAsThisProcess && inCache(imageAddress) ) {
 401         addInfoFromLoadCommands((mach_header*)imageAddress, imageAddress, 32*1024);
 402     }
 403     else {
 404         __block kern_return_t kr = KERN_SUCCESS;
 405         withRemoteObject(task, imageAddress, &kr, ^(mach_header_64 mhBuffer) {
 406             size_t          headerPagesSize = sizeof(mach_header_64) + mhBuffer.sizeofcmds;
 407             withRemoteBuffer(task, imageAddress, headerPagesSize, false, &kr, ^(void * buffer) {
 408                 addInfoFromLoadCommands((mach_header*)buffer, imageAddress, headerPagesSize);
 409             });
 410         });
 411         if (kr != KERN_SUCCESS) {
 412             return kr;
 413         }
 414     }
 415     _curImage->segmentsCount = _curSegmentIndex - _curImage->segmentStartIndex;
 416     _curImage++;
 417     return KERN_SUCCESS;
 418 }
 419
 420
 421 kern_return_t dyld_process_info_base::addDyldImage(task_t task, uint64_t dyldAddress, uint64_t dyldPathAddress, const char* localPath)
 422 {
 423     __block kern_return_t kr = KERN_SUCCESS;
 424     _curImage->loadAddress = dyldAddress;
 425     _curImage->segmentStartIndex = _curSegmentIndex;
 426     if ( localPath != NULL ) {
 427         _curImage->path = addString(localPath);
 428     }
 429     else {
 430         _curImage->path = copyPath(task, dyldPathAddress, &kr);
 431         if ( kr )
 432             return kr;
 433     }
 434
 435     withRemoteObject(task, dyldAddress, &kr, ^(mach_header_64 mhBuffer) {
 436         size_t          headerPagesSize = sizeof(mach_header_64) + mhBuffer.sizeofcmds;
 437         withRemoteBuffer(task, dyldAddress, headerPagesSize, false, &kr, ^(void * buffer) {
 438             addInfoFromLoadCommands((mach_header*)buffer, dyldAddress, headerPagesSize);
 439         });
 440     });
 441     if (kr != KERN_SUCCESS) {
 442         return kr;
 443     }
 444
 445     _curImage->segmentsCount = _curSegmentIndex - _curImage->segmentStartIndex;
 446     _curImage++;
 447     return KERN_SUCCESS;
 448 }
 449
 450
 451 void dyld_process_info_base::addInfoFromLoadCommands(const mach_header* mh, uint64_t addressInTask, size_t size)
 452 {
 453     const load_command* startCmds = NULL;
 454     if ( mh->magic == MH_MAGIC_64 )
 455         startCmds = (load_command*)((char *)mh + sizeof(mach_header_64));
 456     else if ( mh->magic == MH_MAGIC )
 457         startCmds = (load_command*)((char *)mh + sizeof(mach_header));
 458     else
 459         return;  // not a mach-o file, or wrong endianness
 460
 461     const load_command* const cmdsEnd = (load_command*)((char*)startCmds + mh->sizeofcmds);
 462     const load_command* cmd = startCmds;
 463     for(uint32_t i = 0; i < mh->ncmds; ++i) {
 464         const load_command* nextCmd = (load_command*)((char *)cmd + cmd->cmdsize);
 465         if ( (cmd->cmdsize < 8) || (nextCmd > cmdsEnd) || (nextCmd < startCmds) ) {
 466             return;  // malformed load command
 467         }
 468         if ( cmd->cmd == LC_UUID ) {
 469             const uuid_command* uuidCmd = (uuid_command*)cmd;
 470             memcpy(_curImage->uuid, uuidCmd->uuid, 16);
 471         }
 472         else if ( cmd->cmd == LC_SEGMENT ) {
 473             const segment_command* segCmd = (segment_command*)cmd;
 474             _curSegment->name = copySegmentName(segCmd->segname);
 475             _curSegment->addr = segCmd->vmaddr;
 476             _curSegment->size = segCmd->vmsize;
 477             _curSegment++;
 478             _curSegmentIndex++;
 479         }
 480         else if ( cmd->cmd == LC_SEGMENT_64 ) {
 481             const segment_command_64* segCmd = (segment_command_64*)cmd;
 482             _curSegment->name = copySegmentName(segCmd->segname);
 483             _curSegment->addr = segCmd->vmaddr;
 484             _curSegment->size = segCmd->vmsize;
 485             _curSegment++;
 486             _curSegmentIndex++;
 487         }
 488         cmd = nextCmd;
 489     }
 490 }
 491
 492 const char* dyld_process_info_base::copySegmentName(const char* name)
 493 {
 494     // don't copy names of standard segments into string pool
 495     static const char* stdSegNames[] = {"__TEXT", "__DATA", "__LINKEDIT", "__DATA_DIRTY", "__DATA_CONST", "__OBJC", NULL };
 496     for (const char** s=stdSegNames; *s != NULL; ++s) {
 497         if ( strcmp(name, *s) == 0 )
 498         return *s;
 499     }
 500     // copy custom segment names into string pool
 501     return addString(name);
 502 }
 503
 504 void dyld_process_info_base::forEachImage(void (^callback)(uint64_t machHeaderAddress, const uuid_t uuid, const char* path)) const
 505 {
 506     for (const ImageInfo* p = _firstImage; p < _curImage; ++p) {
 507         callback(p->loadAddress, p->uuid, p->path);
 508     }
 509 }
 510
 511 void dyld_process_info_base::forEachSegment(uint64_t machHeaderAddress, void (^callback)(uint64_t segmentAddress, uint64_t segmentSize, const char* segmentName)) const
 512 {
 513     for (const ImageInfo* p = _firstImage; p < _curImage; ++p) {
 514         if ( p->loadAddress == machHeaderAddress ) {
 515             uint64_t slide = 0;
 516             for (int i=0; i < p->segmentsCount; ++i) {
 517                 const SegmentInfo* seg = &_firstSegment[p->segmentStartIndex+i];
 518                 if ( strcmp(seg->name, "__TEXT") == 0 ) {
 519                     slide = machHeaderAddress - seg->addr;
 520                     break;
 521                 }
 522             }
 523             for (int i=0; i < p->segmentsCount; ++i) {
 524                 const SegmentInfo* seg = &_firstSegment[p->segmentStartIndex+i];
 525                 callback(seg->addr + slide, seg->size, seg->name);
 526             }
 527             break;
 528         }
 529     }
 530 }
 531
 532
 533
 534
 535
 536 // Implementation that works with existing dyld data structures
 537 static dyld_process_info _dyld_process_info_create_inner(task_t task, uint64_t timestamp, kern_return_t* kr)
 538 {
 539     if ( kr != NULL )
 540         *kr = KERN_SUCCESS;
 541
 542     task_dyld_info_data_t task_dyld_info;
 543     mach_msg_type_number_t count = TASK_DYLD_INFO_COUNT;
 544     if ( kern_return_t r = task_info(task, TASK_DYLD_INFO, (task_info_t)&task_dyld_info, &count) ) {
 545         if ( kr != NULL )
 546             *kr = r;
 547         return  NULL;
 548     }
 549
 550     //The kernel will return MACH_VM_MIN_ADDRESS for an executable that has not had dyld loaded
 551     if (task_dyld_info.all_image_info_addr == MACH_VM_MIN_ADDRESS)
 552         return NULL;
 553
 554     if ( task_dyld_info.all_image_info_size > sizeof(dyld_all_image_infos_64) )
 555         return NULL;
 556
 557     // read all_image_infos struct
 558     dyld_all_image_infos_64 allImageInfo64;
 559     mach_vm_size_t readSize = task_dyld_info.all_image_info_size;
 560     if ( kern_return_t r = mach_vm_read_overwrite(task, task_dyld_info.all_image_info_addr, task_dyld_info.all_image_info_size, (vm_address_t)&allImageInfo64, &readSize) ) {
 561         if ( kr != NULL )
 562             *kr = r;
 563         return  NULL;
 564     }
 565     if ( allImageInfo64.infoArrayCount == 0 ) {
 566         // could be task was launch suspended or still launching, wait a moment to see
 567         usleep(1000 * 50); // 50ms
 568         if ( kern_return_t r = mach_vm_read_overwrite(task, task_dyld_info.all_image_info_addr, task_dyld_info.all_image_info_size, (vm_address_t)&allImageInfo64, &readSize) ) {
 569             if ( kr != NULL )
 570                 *kr = r;
 571             return  NULL;
 572         }
 573         // if infoArrayCount is still zero, then target was most likely launched suspended
 574         if ( allImageInfo64.infoArrayCount == 0 )
 575             return dyld_process_info_base::makeSuspended(task, kr);
 576     }
 577
 578     // bail out of dyld is too old
 579     if ( allImageInfo64.version < 15 ) {
 580         if ( kr != NULL )
 581             *kr = KERN_INVALID_HOST;
 582         return NULL;
 583     }
 584
 585     // normalize by expanding 32-bit all_image_infos into 64-bit one
 586     uint32_t imageCount = allImageInfo64.infoArrayCount;
 587     size_t imageArraySize = imageCount * sizeof(dyld_image_info_64);
 588     if ( task_dyld_info.all_image_info_format == TASK_DYLD_ALL_IMAGE_INFO_32 ) {
 589         const dyld_all_image_infos_32* allImageInfo32 = (dyld_all_image_infos_32*)&allImageInfo64;
 590         dyld_all_image_infos_64 info64;
 591         bzero(&info64, sizeof(info64));
 592         info64.version                  = allImageInfo32->version;
 593         info64.infoArrayCount           = allImageInfo32->infoArrayCount;
 594         info64.infoArray                = allImageInfo32->infoArray;
 595         info64.processDetachedFromSharedRegion = allImageInfo32->processDetachedFromSharedRegion;
 596         info64.libSystemInitialized     = allImageInfo32->libSystemInitialized;
 597         info64.dyldImageLoadAddress     = allImageInfo32->dyldImageLoadAddress;
 598         info64.initialImageCount        = allImageInfo32->initialImageCount;
 599         info64.uuidArrayCount           = allImageInfo32->uuidArrayCount;
 600         info64.uuidArray                = allImageInfo32->uuidArray;
 601         info64.dyldAllImageInfosAddress = allImageInfo32->dyldAllImageInfosAddress;
 602         info64.sharedCacheSlide         = allImageInfo32->sharedCacheSlide;
 603         info64.infoArrayChangeTimestamp = allImageInfo32->infoArrayChangeTimestamp;
 604         info64.sharedCacheBaseAddress   = allImageInfo32->sharedCacheBaseAddress;
 605         info64.dyldPath                 = allImageInfo32->dyldPath;
 606         memcpy((void*)(info64.sharedCacheUUID), (void*)(allImageInfo32->sharedCacheUUID), 16);
 607         allImageInfo64 = info64;
 608         imageCount = allImageInfo64.infoArrayCount;
 609         imageArraySize = imageCount * sizeof(dyld_image_info_32);
 610     }
 611
 612     // don't do any (more) work if target process's dyld timestamp has not changed since previous query
 613     if ( (timestamp != 0) && (timestamp == allImageInfo64.infoArrayChangeTimestamp) ) {
 614         if ( kr != NULL )
 615             *kr = KERN_SUCCESS;
 616         return NULL;
 617     }
 618
 619     // For the moment we are going to truncate any image list longer than 8192 because some programs do
 620     // terrible things that corrupt their own image lists and we need to stop clients from crashing
 621     // reading them. We can try to do something more advanced in the future. rdar://27446361
 622     imageCount = MIN(imageCount, 8192);
 623
 624     // read image array
 625     if ( allImageInfo64.infoArray == 0 ) {
 626         // dyld is in middle of updating image list, try again
 627         return NULL;
 628     }
 629     dyld_image_info_64 imageArray64[imageCount];
 630     if ( kern_return_t r = mach_vm_read_overwrite(task, allImageInfo64.infoArray, imageArraySize, (vm_address_t)&imageArray64, &readSize) ) {
 631         // if image array moved, try whole thing again
 632         if ( kr != NULL ) {
 633             *kr = r;
 634         }
 635         return  NULL;
 636     }
 637     // normalize by expanding 32-bit image_infos into 64-bit ones
 638     if ( task_dyld_info.all_image_info_format == TASK_DYLD_ALL_IMAGE_INFO_32 ) {
 639         const dyld_image_info_32* imageArray32 = (dyld_image_info_32*)&imageArray64;
 640         dyld_image_info_64 tempArray[imageCount];
 641         for (uint32_t i=0; i < imageCount; ++i) {
 642             tempArray[i].imageLoadAddress = imageArray32[i].imageLoadAddress;
 643             tempArray[i].imageFilePath    = imageArray32[i].imageFilePath;
 644             tempArray[i].imageFileModDate = imageArray32[i].imageFileModDate;
 645         }
 646         memcpy(imageArray64, tempArray, sizeof(dyld_image_info_64)*imageCount);
 647     }
 648
 649     // create object based on local copy of all image infos and image array
 650     dyld_process_info result = dyld_process_info_base::make(task, allImageInfo64, imageArray64, kr);
 651
 652     // verify nothing has changed by re-reading all_image_infos struct and checking timestamp
 653     if ( result != NULL ) {
 654         dyld_all_image_infos_64 allImageInfo64again;
 655         readSize = task_dyld_info.all_image_info_size;
 656         if ( kern_return_t r = mach_vm_read_overwrite(task, task_dyld_info.all_image_info_addr, task_dyld_info.all_image_info_size, (vm_address_t)&allImageInfo64again, &readSize) ) {
 657             if ( kr != NULL )
 658                 *kr = r;
 659             free((void*)result);
 660             return  NULL;
 661         }
 662         uint64_t doneTimeStamp = allImageInfo64again.infoArrayChangeTimestamp;
 663         if ( task_dyld_info.all_image_info_format == TASK_DYLD_ALL_IMAGE_INFO_32 ) {
 664             const dyld_all_image_infos_32* allImageInfo32 = (dyld_all_image_infos_32*)&allImageInfo64again;
 665             doneTimeStamp = allImageInfo32->infoArrayChangeTimestamp;
 666         }
 667         if ( allImageInfo64.infoArrayChangeTimestamp != doneTimeStamp ) {
 668             // image list has changed since we started reading it
 669             // throw out what we have and start over
 670             free((void*)result);
 671             result = nullptr;
 672         }
 673     }
 674
 675     return result;
 676 }
 677
 678
 679 dyld_process_info _dyld_process_info_create(task_t task, uint64_t timestamp, kern_return_t* kr)
 680 {
 681     // Other process may be loading and unloading as we read its memory, which can cause a read failure
 682     // <rdar://problem30067343&29567679> Retry if something fails
 683     for (int i=0; i < 100; ++i) {
 684         if ( dyld_process_info result = _dyld_process_info_create_inner( task,  timestamp, kr) )
 685             return result;
 686
 687     }
 688     return NULL;
 689 }
 690
 691 void _dyld_process_info_get_state(dyld_process_info info, dyld_process_state_info* stateInfo)
 692 {
 693     *stateInfo = *info->stateInfo();
 694 }
 695
 696 void _dyld_process_info_get_cache(dyld_process_info info, dyld_process_cache_info* cacheInfo)
 697 {
 698     *cacheInfo = *info->cacheInfo();
 699 }
 700
 701 void _dyld_process_info_retain(dyld_process_info info)
 702 {
 703     info->retainCount() += 1;
 704 }
 705
 706 void _dyld_process_info_release(dyld_process_info info)
 707 {
 708     info->retainCount() -= 1;
 709     if ( info->retainCount() == 0 )
 710         free((void*)info);
 711 }
 712
 713 void _dyld_process_info_for_each_image(dyld_process_info info, void (^callback)(uint64_t machHeaderAddress, const uuid_t uuid, const char* path))
 714 {
 715     info->forEachImage(callback);
 716 }
 717
 718
 719 void _dyld_process_info_for_each_segment(dyld_process_info info, uint64_t machHeaderAddress, void (^callback)(uint64_t segmentAddress, uint64_t segmentSize, const char* segmentName))
 720 {
 721     info->forEachSegment(machHeaderAddress, callback);
 722 }
 723
 724
 725