src/ImageLoader.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.
  21  *
  22  * @APPLE_LICENSE_HEADER_END@
  23  */
  24
  25 #define __STDC_LIMIT_MACROS
  26 #include <stdint.h>
  27 #include <errno.h>
  28 #include <fcntl.h>
  29 #include <mach/mach.h>
  30 #include <mach-o/fat.h>
  31 #include <sys/types.h>
  32 #include <sys/stat.h>
  33 #include <sys/mman.h>
  34
  35 #include "ImageLoader.h"
  36
  37
  38 uint32_t                                                                ImageLoader::fgImagesWithUsedPrebinding = 0;
  39 uint32_t                                                                ImageLoader::fgTotalRebaseFixups = 0;
  40 uint32_t                                                                ImageLoader::fgTotalBindFixups = 0;
  41 uint32_t                                                                ImageLoader::fgTotalLazyBindFixups = 0;
  42 uint32_t                                                                ImageLoader::fgTotalPossibleLazyBindFixups = 0;
  43 uint64_t                                                                ImageLoader::fgTotalLoadLibrariesTime;
  44 uint64_t                                                                ImageLoader::fgTotalRebaseTime;
  45 uint64_t                                                                ImageLoader::fgTotalBindTime;
  46 uint64_t                                                                ImageLoader::fgTotalNotifyTime;
  47 uint64_t                                                                ImageLoader::fgTotalInitTime;
  48 uintptr_t                                                               ImageLoader::fgNextSplitSegAddress = 0x90000000;
  49 uintptr_t                                                               Segment::fgNextNonSplitSegAddress = 0x8FE00000;
  50
  51
  52
  53 __attribute__((noreturn))
  54 void throwf(const char* format, ...)
  55 {
  56         va_list list;
  57         char*   p;
  58         va_start(list, format);
  59         vasprintf(&p, format, list);
  60         va_end(list);
  61
  62         const char*     t = p;
  63         throw t;
  64 }
  65
  66 void ImageLoader::init(const char* path, uint64_t offsetInFat, dev_t device, ino_t inode, time_t modDate)
  67 {
  68         fPathHash = 0;
  69         fPath = NULL;
  70         if ( path != NULL )
  71                 this->setPath(path);
  72         fLogicalPath = NULL;
  73         fDevice = device;
  74         fInode = inode;
  75         fLastModified = modDate;
  76         fOffsetInFatFile = offsetInFat;
  77         //fSegments = NULL;
  78         fLibraries = NULL;
  79         fLibrariesCount = 0;
  80         fReferenceCount = 0;
  81         fAllLibraryChecksumsAndLoadAddressesMatch = false;
  82         fLeaveMapped = false;
  83         fHideSymbols = false;
  84         fMatchByInstallName = false;
  85         fLibrariesLoaded = false;
  86         fBased = false;
  87         fBoundAllNonLazy = false;
  88         fBoundAllLazy = false;
  89         fAnnounced = false;
  90         fInitialized = false;
  91         fNextAddImageIndex = 0;
  92 }
  93
  94
  95 ImageLoader::ImageLoader(const char* path, uint64_t offsetInFat, const struct stat& info)
  96 {
  97         init(path, offsetInFat, info.st_dev, info.st_ino, info.st_mtime);
  98 }
  99
 100 ImageLoader::ImageLoader(const char* moduleName)
 101 {
 102         init(moduleName, 0, 0, 0, 0);
 103 }
 104
 105
 106 ImageLoader::~ImageLoader()
 107 {
 108         // need to read up on STL and see if this is right way to destruct vector contents
 109         const unsigned int segmentCount = fSegments.size();
 110         for(unsigned int i=0; i < segmentCount; ++i){
 111                 Segment* seg = fSegments[i];
 112                 delete seg;
 113         }
 114         if ( fPath != NULL )
 115                 delete [] fPath;
 116         if ( fLogicalPath != NULL )
 117                 delete [] fLogicalPath;
 118 }
 119
 120
 121 void ImageLoader::setPath(const char* path)
 122 {
 123         if ( fPath != NULL ) {
 124                 // if duplicate path, do nothing
 125                 if ( strcmp(path, fPath) == 0 )
 126                         return;
 127                 delete [] fPath;
 128         }
 129         fPath = new char[strlen(path)+1];
 130         strcpy((char*)fPath, path);
 131         fPathHash = hash(fPath);
 132 }
 133
 134 void ImageLoader::setLogicalPath(const char* path)
 135 {
 136         if ( fPath == NULL ) {
 137                 // no physical path set yet, so use this path as physical
 138                 this->setPath(path);
 139         }
 140         else if ( strcmp(path, fPath) == 0 ) {
 141                 // do not set logical path because it is the same as the physical path
 142                 fLogicalPath = NULL;
 143         }
 144         else {
 145                 fLogicalPath = new char[strlen(path)+1];
 146                 strcpy((char*)fLogicalPath, path);
 147         }
 148 }
 149
 150 const char* ImageLoader::getLogicalPath() const
 151 {
 152         if ( fLogicalPath != NULL )
 153                 return fLogicalPath;
 154         else
 155                 return fPath;
 156 }
 157
 158 uint32_t ImageLoader::hash(const char* path)
 159 {
 160         // this does not need to be a great hash
 161         // it is just used to reduce the number of strcmp() calls
 162         // of existing images when loading a new image
 163         uint32_t h = 0;
 164         for (const char* s=path; *s != '\0'; ++s)
 165                 h = h*5 + *s;
 166         return h;
 167 }
 168
 169 bool ImageLoader::matchInstallPath() const
 170 {
 171         return fMatchByInstallName;
 172 }
 173
 174 void ImageLoader::setMatchInstallPath(bool match)
 175 {
 176         fMatchByInstallName = match;
 177 }
 178
 179 bool ImageLoader::statMatch(const struct stat& stat_buf) const
 180 {
 181         return ( (this->fDevice == stat_buf.st_dev) && (this->fInode == stat_buf.st_ino) );
 182 }
 183
 184 const char* ImageLoader::getShortName() const
 185 {
 186         // try to return leaf name
 187         if ( fPath != NULL ) {
 188                 const char* s = strrchr(fPath, '/');
 189                 if ( s != NULL )
 190                         return &s[1];
 191         }
 192         return fPath;
 193 }
 194
 195 uint64_t ImageLoader::getOffsetInFatFile() const
 196 {
 197         return fOffsetInFatFile;
 198 }
 199
 200 void ImageLoader::setLeaveMapped()
 201 {
 202         fLeaveMapped = true;
 203         const unsigned int segmentCount = fSegments.size();
 204         for(unsigned int i=0; i < segmentCount; ++i){
 205                 fSegments[i]->setUnMapWhenDestructed(false);
 206         }
 207 }
 208
 209 void ImageLoader::setHideExports(bool hide)
 210 {
 211         fHideSymbols = hide;
 212 }
 213
 214 bool ImageLoader::hasHiddenExports() const
 215 {
 216         return fHideSymbols;
 217 }
 218
 219 bool ImageLoader::isLinked() const
 220 {
 221         return fBoundAllNonLazy;
 222 }
 223
 224 time_t ImageLoader::lastModified()
 225 {
 226         return fLastModified;
 227 }
 228
 229 bool ImageLoader::containsAddress(const void* addr) const
 230 {
 231         const unsigned int segmentCount = fSegments.size();
 232         for(unsigned int i=0; i < segmentCount; ++i){
 233                 Segment* seg = fSegments[i];
 234                 const uint8_t* start = (const uint8_t*)seg->getActualLoadAddress();
 235                 const uint8_t* end = start + seg->getSize();
 236                 if ( (start <= addr) && (addr < end) && !seg->unaccessible() )
 237                         return true;
 238         }
 239         return false;
 240 }
 241
 242 void ImageLoader::addMappedRegions(RegionsVector& regions) const
 243 {
 244         const unsigned int segmentCount = fSegments.size();
 245         for(unsigned int i=0; i < segmentCount; ++i){
 246                 Segment* seg = fSegments[i];
 247                 MappedRegion region;
 248                 region.address = seg->getActualLoadAddress();
 249                 region.size = seg->getSize();
 250                 regions.push_back(region);
 251         }
 252 }
 253
 254
 255 void ImageLoader::incrementReferenceCount()
 256 {
 257         ++fReferenceCount;
 258 }
 259
 260 bool ImageLoader::decrementReferenceCount()
 261 {
 262         return ( --fReferenceCount == 0 );
 263 }
 264
 265
 266 const ImageLoader::Symbol* ImageLoader::resolveSymbol(const char* name, bool searchSelf, ImageLoader** foundIn) const
 267 {
 268         const ImageLoader::Symbol* sym;
 269         // search self
 270         if ( searchSelf ) {
 271                 sym = this->findExportedSymbol(name, NULL, false, foundIn);
 272                 if ( sym != NULL )
 273                         return sym;
 274         }
 275
 276         // search directly dependent libraries
 277         for (uint32_t i=0; i < fLibrariesCount; ++i) {
 278                 ImageLoader* dependentImage = fLibraries[i].image;
 279                 if ( dependentImage != NULL ) {
 280                         const ImageLoader::Symbol* sym = dependentImage->findExportedSymbol(name, NULL, false, foundIn);
 281                         if ( sym != NULL )
 282                                 return sym;
 283                 }
 284         }
 285
 286         // search indirectly dependent libraries
 287         for (uint32_t i=0; i < fLibrariesCount; ++i) {
 288                 ImageLoader* dependentImage = fLibraries[i].image;
 289                 if ( dependentImage != NULL ) {
 290                         const ImageLoader::Symbol* sym = dependentImage->resolveSymbol(name, false, foundIn);
 291                         if ( sym != NULL )
 292                                 return sym;
 293                 }
 294         }
 295
 296         return NULL;
 297 }
 298
 299
 300
 301 void ImageLoader::link(const LinkContext& context, BindingLaziness bindness, InitializerRunning inits, uint32_t notifyCount)
 302 {
 303         uint64_t t1 = mach_absolute_time();
 304         this->recursiveLoadLibraries(context);
 305
 306         uint64_t t2 = mach_absolute_time();
 307         this->recursiveRebase(context);
 308
 309         uint64_t t3 = mach_absolute_time();
 310         this->recursiveBind(context, bindness);
 311
 312         uint64_t t4 = mach_absolute_time();
 313         this->recursiveImageNotification(context, notifyCount);
 314
 315         if ( (inits == kRunInitializers) || (inits == kDontRunInitializersButTellObjc) ) {
 316                 std::vector<ImageLoader*>       newImages;
 317                 this->recursiveImageAnnouncement(context, newImages);    // build bottom up list images being added
 318                 context.notifyAdding(newImages);        // tell gdb or anyone who cares about these
 319         }
 320
 321         uint64_t t5 = mach_absolute_time();
 322         if ( inits == kRunInitializers ) {
 323                 this->recursiveInitialization(context);
 324                 uint64_t t6 = mach_absolute_time();
 325                 fgTotalInitTime += t6 - t5;
 326         }
 327         fgTotalLoadLibrariesTime += t2 - t1;
 328         fgTotalRebaseTime += t3 - t2;
 329         fgTotalBindTime += t4 - t3;
 330         fgTotalNotifyTime += t5 - t4;
 331 }
 332
 333
 334 // only called pre-main on main executable
 335 // if crt.c is ever cleaned up, this could go away
 336 void ImageLoader::runInitializers(const LinkContext& context)
 337 {
 338                 std::vector<ImageLoader*>       newImages;
 339                 this->recursiveImageAnnouncement(context, newImages);    // build bottom up list images being added
 340                 context.notifyAdding(newImages);        // tell gdb or anyone who cares about these
 341
 342         this->recursiveInitialization(context);
 343 }
 344
 345 // called inside _dyld_register_func_for_add_image()
 346 void ImageLoader::runNotification(const LinkContext& context, uint32_t notifyCount)
 347 {
 348         this->recursiveImageNotification(context, notifyCount);
 349 }
 350
 351
 352 intptr_t ImageLoader::assignSegmentAddresses(const LinkContext& context)
 353 {
 354         // preflight and calculate slide if needed
 355         const unsigned int segmentCount = fSegments.size();
 356         intptr_t slide = 0;
 357         if ( this->segmentsCanSlide() && this->segmentsMustSlideTogether() ) {
 358                 bool needsToSlide = false;
 359                 uintptr_t lowAddr = UINTPTR_MAX;
 360                 uintptr_t highAddr = 0;
 361                 for(unsigned int i=0; i < segmentCount; ++i){
 362                         Segment* seg = fSegments[i];
 363                         const uintptr_t segLow = seg->getPreferredLoadAddress();
 364                         const uintptr_t segHigh = segLow + seg->getSize();
 365                         if ( segLow < lowAddr )
 366                                 lowAddr = segLow;
 367                         if ( segHigh > highAddr )
 368                                 highAddr = segHigh;
 369
 370                         if ( context.slideAndPackDylibs || !seg->hasPreferredLoadAddress() || !Segment::reserveAddressRange(seg->getPreferredLoadAddress(), seg->getSize()) )
 371                                 needsToSlide = true;
 372                 }
 373                 if ( needsToSlide ) {
 374                         // find a chunk of address space to hold all segments
 375                         uintptr_t addr = Segment::reserveAnAddressRange(highAddr-lowAddr, context);
 376                         slide = addr - lowAddr;
 377                 }
 378         }
 379         else if ( ! this->segmentsCanSlide() ) {
 380                 for(unsigned int i=0; i < segmentCount; ++i){
 381                         Segment* seg = fSegments[i];
 382                         if ( strcmp(seg->getName(), "__PAGEZERO") == 0 )
 383                                 continue;
 384                         if ( !Segment::reserveAddressRange(seg->getPreferredLoadAddress(), seg->getSize()) )
 385                                 throw "can't map";
 386                 }
 387         }
 388         else {
 389                 // mach-o does not support independently sliding segments
 390         }
 391         return slide;
 392 }
 393
 394
 395 void ImageLoader::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
 396 {
 397         if ( context.verboseMapping )
 398                 fprintf(stderr, "dyld: Mapping %s\n", this->getPath());
 399         // find address range for image
 400         intptr_t slide = this->assignSegmentAddresses(context);
 401         // map in all segments
 402         const unsigned int segmentCount = fSegments.size();
 403         for(unsigned int i=0; i < segmentCount; ++i){
 404                 Segment* seg = fSegments[i];
 405                 seg->map(fd, offsetInFat, slide, context);
 406         }
 407         // update slide to reflect load location
 408         this->setSlide(slide);
 409
 410         // now that it is mapped and slide is set, mark that we should unmap it when done
 411         for(unsigned int i=0; i < segmentCount; ++i){
 412                 fSegments[i]->setUnMapWhenDestructed(true);
 413         }
 414 }
 415
 416 void ImageLoader::mapSegments(const void* memoryImage, uint64_t imageLen, const LinkContext& context)
 417 {
 418         if ( context.verboseMapping )
 419                 fprintf(stderr, "dyld: Mapping memory %p\n", memoryImage);
 420         // find address range for image
 421         intptr_t slide = this->assignSegmentAddresses(context);
 422         // map in all segments
 423         const unsigned int segmentCount = fSegments.size();
 424         for(unsigned int i=0; i < segmentCount; ++i){
 425                 Segment* seg = fSegments[i];
 426                 seg->map(memoryImage, slide, context);
 427         }
 428         // update slide to reflect load location
 429         this->setSlide(slide);
 430         // set R/W permissions on all segments at slide location
 431         for(unsigned int i=0; i < segmentCount; ++i){
 432                 Segment* seg = fSegments[i];
 433                 seg->setPermissions();
 434         }
 435 }
 436
 437 bool ImageLoader::allDependentLibrariesAsWhenPreBound() const
 438 {
 439         return fAllLibraryChecksumsAndLoadAddressesMatch;
 440 }
 441
 442
 443 void ImageLoader::recursiveLoadLibraries(const LinkContext& context)
 444 {
 445         if ( ! fLibrariesLoaded ) {
 446                 // break cycles
 447                 fLibrariesLoaded = true;
 448
 449                 // get list of libraries this image needs
 450                 fLibrariesCount = this->doGetDependentLibraryCount();
 451                 fLibraries = new DependentLibrary[fLibrariesCount];
 452                 this->doGetDependentLibraries(fLibraries);
 453
 454                 // try to load each
 455                 bool canUsePrelinkingInfo = true;
 456                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 457                         DependentLibrary& requiredLib = fLibraries[i];
 458                         try {
 459                                 requiredLib.image = context.loadLibrary(requiredLib.name, true, this->getPath(), NULL);
 460                                 if ( requiredLib.image == this ) {
 461                                         // found circular reference, perhaps DYLD_LIBARY_PATH is causing this rdar://problem/3684168
 462                                         requiredLib.image = context.loadLibrary(requiredLib.name, false, NULL, NULL);
 463                                         if ( requiredLib.image != this )
 464                                                 fprintf(stderr, "dyld: warning DYLD_ setting caused circular dependency in %s\n", this->getPath());
 465                                 }
 466                                 LibraryInfo actualInfo = requiredLib.image->doGetLibraryInfo();
 467                                 requiredLib.checksumMatches = ( actualInfo.checksum == requiredLib.info.checksum );
 468                                 // check found library version is compatible
 469                                 if ( actualInfo.minVersion < requiredLib.info.minVersion ) {
 470                                         throwf("Incompatible library version: %s requires version %d.%d.%d or later, but %s provides version %d.%d.%d",
 471                                                         this->getShortName(), requiredLib.info.minVersion >> 16, (requiredLib.info.minVersion >> 8) & 0xff, requiredLib.info.minVersion & 0xff,
 472                                                         requiredLib.image->getShortName(), actualInfo.minVersion >> 16, (actualInfo.minVersion >> 8) & 0xff, actualInfo.minVersion & 0xff);
 473                                 }
 474                                 // prebinding for this image disabled if any dependent library changed or slid
 475                                 if ( !requiredLib.checksumMatches || (requiredLib.image->getSlide() != 0) )
 476                                         canUsePrelinkingInfo = false;
 477                                 //if ( context.verbosePrebinding ) {
 478                                 //      if ( !requiredLib.checksumMatches )
 479                                 //              fprintf(stderr, "dyld: checksum mismatch, (%lld v %lld) for %s referencing %s\n", requiredLib.info.checksum, actualInfo.checksum, this->getPath(),      requiredLib.image->getPath());
 480                                 //      if ( requiredLib.image->getSlide() != 0 )
 481                                 //              fprintf(stderr, "dyld: dependent library slid for %s referencing %s\n", this->getPath(), requiredLib.image->getPath());
 482                                 //}
 483                         }
 484                         catch (const char* msg) {
 485                                 //if ( context.verbosePrebinding )
 486                                 //      fprintf(stderr, "dyld: exception during processing for %s referencing %s\n", this->getPath(), requiredLib.image->getPath());
 487                                 if ( requiredLib.required ) {
 488                                         const char* formatString = "Library not loaded: %s\n  Referenced from: %s\n  Reason: %s";
 489                                         const char* referencedFrom = this->getPath();
 490                                         char buf[strlen(requiredLib.name)+strlen(referencedFrom)+strlen(formatString)+strlen(msg)+2];
 491                                         sprintf(buf, formatString, requiredLib.name, referencedFrom, msg);
 492                                         throw strdup(buf);  // this is a leak if exception doesn't halt program
 493                                 }
 494                                 // ok if weak library not found
 495                                 requiredLib.image = NULL;
 496                                 canUsePrelinkingInfo = false;  // this disables all prebinding, we may want to just slam import vectors for this lib to zero
 497                         }
 498                 }
 499                 fAllLibraryChecksumsAndLoadAddressesMatch = canUsePrelinkingInfo;
 500
 501                 // tell each to load its dependents
 502                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 503                         DependentLibrary& libInfo = fLibraries[i];
 504                         if ( libInfo.image != NULL ) {
 505                                 libInfo.isSubFramework = libInfo.image->isSubframeworkOf(context, this);
 506                                 libInfo.isReExported = libInfo.isSubFramework || this->hasSubLibrary(context, libInfo.image);
 507                                 //if ( libInfo.isReExported  )
 508                                 //      fprintf(stderr, "%s re-exports %s\n", strrchr(this->getPath(), '/'), strrchr(libInfo.image->getPath(),'/'));
 509                                 libInfo.image->recursiveLoadLibraries(context);
 510                         }
 511                 }
 512
 513                 // do deep prebind check
 514                 if ( fAllLibraryChecksumsAndLoadAddressesMatch ) {
 515                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 516                                 const DependentLibrary& libInfo = fLibraries[i];
 517                                 if ( libInfo.image != NULL ) {
 518                                         if ( !libInfo.image->allDependentLibrariesAsWhenPreBound() )
 519                                                 fAllLibraryChecksumsAndLoadAddressesMatch = false;
 520                                 }
 521                         }
 522                 }
 523
 524         }
 525 }
 526
 527 void ImageLoader::recursiveRebase(const LinkContext& context)
 528 {
 529         if ( ! fBased ) {
 530                 // break cycles
 531                 fBased = true;
 532
 533                 try {
 534                         // rebase lower level libraries first
 535                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 536                                 DependentLibrary& libInfo = fLibraries[i];
 537                                 if ( libInfo.image != NULL )
 538                                         libInfo.image->recursiveRebase(context);
 539                         }
 540
 541                         // rebase this image
 542                         doRebase(context);
 543                 }
 544                 catch (const char* msg) {
 545                         // this image is not rebased
 546                         fBased = false;
 547                         throw msg;
 548                 }
 549         }
 550 }
 551
 552
 553
 554
 555 void ImageLoader::recursiveBind(const LinkContext& context, BindingLaziness bindness)
 556 {
 557         // normally just non-lazy pointers are bound up front,
 558         // but DYLD_BIND_AT_LAUNCH will cause lazy pointers to be bound up from
 559         // and some dyld API's bind all lazys at runtime
 560         bool nonLazy = false;
 561         bool lazy = false;
 562         switch( bindness ) {
 563                 case kNonLazyOnly:
 564                         nonLazy = true;
 565                         break;
 566                 case kLazyAndNonLazy:
 567                         nonLazy = true;
 568                         lazy = true;
 569                         break;
 570                 case kLazyOnly:
 571                 case kLazyOnlyNoDependents:
 572                         lazy = true;
 573                         break;
 574         }
 575         const bool doNonLazy = nonLazy && !fBoundAllNonLazy;
 576         const bool doLazy = lazy && !fBoundAllLazy;
 577         if ( doNonLazy || doLazy ) {
 578                 // break cycles
 579                 bool oldBoundAllNonLazy = fBoundAllNonLazy;
 580                 bool oldBoundAllLazy = fBoundAllLazy;
 581                 fBoundAllNonLazy = fBoundAllNonLazy || nonLazy;
 582                 fBoundAllLazy = fBoundAllLazy || lazy;
 583
 584                 try {
 585                         // bind lower level libraries first
 586                         if ( bindness != kLazyOnlyNoDependents ) {
 587                                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 588                                         DependentLibrary& libInfo = fLibraries[i];
 589                                         if ( libInfo.image != NULL )
 590                                                 libInfo.image->recursiveBind(context, bindness);
 591                                 }
 592                         }
 593                         // bind this image
 594                         if ( doLazy && !doNonLazy )
 595                                 doBind(context, kLazyOnly);
 596                         else if ( !doLazy && doNonLazy )
 597                                 doBind(context, kNonLazyOnly);
 598                         else
 599                                 doBind(context, kLazyAndNonLazy);
 600                 }
 601                 catch (const char* msg) {
 602                         // restore state
 603                         fBoundAllNonLazy = oldBoundAllNonLazy;
 604                         fBoundAllLazy = oldBoundAllLazy;
 605                         throw msg;
 606                 }
 607         }
 608 }
 609
 610 //
 611 // This is complex because _dyld_register_func_for_add_image() is defined to not only
 612 // notify you of future image loads, but also of all currently loaded images.  Therefore
 613 // each image needs to track that all add-image-funcs have been notified about it.
 614 // Since add-image-funcs cannot be removed, each has a unique index and each image
 615 // records the thru which index notificiation has already been done.
 616 //
 617 void ImageLoader::recursiveImageNotification(const LinkContext& context, uint32_t addImageCount)
 618 {
 619         if ( fNextAddImageIndex < addImageCount ) {
 620                 // break cycles
 621                 const uint32_t initIndex = fNextAddImageIndex;
 622                 fNextAddImageIndex = addImageCount;
 623
 624                 // notify all requestors about this image
 625                 context.imageNotification(this, initIndex);
 626
 627                 // notify about lower level libraries first
 628                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 629                         DependentLibrary& libInfo = fLibraries[i];
 630                         if ( libInfo.image != NULL )
 631                                 libInfo.image->recursiveImageNotification(context, addImageCount);
 632                 }
 633         }
 634 }
 635
 636
 637 void ImageLoader::recursiveImageAnnouncement(const LinkContext& context, std::vector<ImageLoader*>& newImages)
 638 {
 639         if ( ! fAnnounced ) {
 640                 // break cycles
 641                 fAnnounced = true;
 642
 643                 // announce lower level libraries first
 644                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 645                         DependentLibrary& libInfo = fLibraries[i];
 646                         if ( libInfo.image != NULL )
 647                                 libInfo.image->recursiveImageAnnouncement(context, newImages);
 648                 }
 649
 650                 // add to list of images to notify gdb about
 651                 newImages.push_back(this);
 652                 //fprintf(stderr, "next size = %d\n", newImages.size());
 653
 654                 // remember that this image wants to be notified about other images
 655                  if ( this->hasImageNotification() )
 656                         context.addImageNeedingNotification(this);
 657         }
 658 }
 659
 660
 661
 662 void ImageLoader::recursiveInitialization(const LinkContext& context)
 663 {
 664         if ( ! fInitialized ) {
 665                 // break cycles
 666                 fInitialized = true;
 667
 668                 try {
 669                         // initialize lower level libraries first
 670                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 671                                 DependentLibrary& libInfo = fLibraries[i];
 672                                 if ( libInfo.image != NULL )
 673                                         libInfo.image->recursiveInitialization(context);
 674                         }
 675
 676                         // record termination order
 677                         if ( this->needsTermination() )
 678                                 context.terminationRecorder(this);
 679
 680                         // initialize this image
 681                         this->doInitialization(context);
 682                 }
 683                 catch (const char* msg) {
 684                         // this image is not initialized
 685                         fInitialized = false;
 686                         throw msg;
 687                 }
 688         }
 689 }
 690
 691 void ImageLoader::reprebindCommit(const LinkContext& context, bool commit)
 692 {
 693         // do nothing on unprebound images
 694         if ( ! this->isPrebindable() )
 695                 return;
 696
 697         // do nothing if prebinding is up to date
 698         if ( this->usablePrebinding(context) )
 699                 return;
 700
 701         // make sure we are not replacing a symlink with a file
 702         char realFilePath[PATH_MAX];
 703         if ( realpath(this->getPath(), realFilePath) == NULL ) {
 704                 throwf("realpath() failed on %s, errno=%d", this->getPath(), errno);
 705         }
 706         // recreate temp file name
 707         char tempFilePath[PATH_MAX];
 708         ImageLoader::addSuffix(realFilePath, "_redoprebinding", tempFilePath);
 709
 710         if ( commit ) {
 711                 // all files successfully reprebound, so do swap
 712                 int result = rename(tempFilePath, realFilePath);
 713                 if ( result != 0 ) {
 714                         // if there are two dylibs with the same install path, the second will fail to prebind
 715                         // because the _redoprebinding temp file is gone.  In that case, log and go on.
 716                         if ( errno == ENOENT )
 717                                 fprintf(stderr, "update_prebinding: temp file missing: %s\n", tempFilePath);
 718                         else
 719                                 throwf("can't swap temporary re-prebound file: rename(%s,%s) returned errno=%d", tempFilePath, realFilePath, errno);
 720                 }
 721         }
 722         else {
 723                 // something went wrong during prebinding, delete the temp files
 724                 unlink(tempFilePath);
 725         }
 726 }
 727
 728 void ImageLoader::reprebind(const LinkContext& context, time_t timestamp)
 729 {
 730         // do nothing on unprebound images
 731         if ( ! this->isPrebindable() )
 732                 return;
 733
 734         // do nothing if prebinding is up to date
 735         if ( this->usablePrebinding(context) ) {
 736                 if ( context.verbosePrebinding )
 737                         fprintf(stderr, "dyld: no need to re-prebind: %s\n", this->getPath());
 738                 return;
 739         }
 740         // make copy of file and map it in
 741         char tempFilePath[PATH_MAX];
 742         realpath(this->getPath(), tempFilePath);
 743         ImageLoader::addSuffix(this->getPath(), "_redoprebinding", tempFilePath);
 744         uint8_t* fileToPrebind;
 745         uint64_t fileToPrebindSize;
 746         this->copyAndMap(tempFilePath, &fileToPrebind, &fileToPrebindSize);
 747
 748         // do format specific prebinding
 749         this->doPrebinding(context, timestamp, fileToPrebind);
 750
 751         // flush and swap files
 752         int result = msync(fileToPrebind, fileToPrebindSize, MS_ASYNC);
 753         if ( result != 0 )
 754                 throw "error syncing re-prebound file";
 755         result = munmap(fileToPrebind, fileToPrebindSize);
 756         if ( result != 0 )
 757                 throw "error unmapping re-prebound file";
 758
 759         // log
 760         if ( context.verbosePrebinding )
 761                 fprintf(stderr, "dyld: re-prebound: %s\n", this->getPath());
 762 }
 763
 764 void ImageLoader::copyAndMap(const char* tempFile, uint8_t** fileToPrebind, uint64_t* fileToPrebindSize)
 765 {
 766         // reopen dylib
 767         int src = open(this->getPath(), O_RDONLY);
 768         if ( src == -1 )
 769                 throw "can't open image";
 770         struct stat stat_buf;
 771         if ( fstat(src, &stat_buf) == -1)
 772                 throw "can't stat image";
 773         if ( stat_buf.st_mtime != fLastModified )
 774                 throw "image file changed since it was loaded";
 775
 776         // create new file with all same permissions to hold copy of dylib
 777         unlink(tempFile);
 778         int dst = open(tempFile, O_CREAT | O_RDWR | O_TRUNC, stat_buf.st_mode);
 779         if ( dst == -1 )
 780                 throw "can't create temp image";
 781
 782         // mark source as "don't cache"
 783         (void)fcntl(src, F_NOCACHE, 1);
 784         // we want to cache the dst because we are about to map it in and modify it
 785
 786         // copy permission bits
 787         if ( chmod(tempFile, stat_buf.st_mode & 07777) == -1 )
 788                 throw "can't chmod temp image";
 789         if ( chown(tempFile, stat_buf.st_uid, stat_buf.st_gid) == -1)
 790                 throw "can't chown temp image";
 791
 792         // copy contents
 793         ssize_t len;
 794         const uint32_t kBufferSize = 128*1024;
 795         static uint8_t* buffer = NULL;
 796         if ( buffer == NULL ) {
 797                 vm_address_t addr = 0;
 798                 if ( vm_allocate(mach_task_self(), &addr, kBufferSize, true /*find range*/) == KERN_SUCCESS )
 799                         buffer = (uint8_t*)addr;
 800                 else
 801                         throw "can't allcoate copy buffer";
 802         }
 803         while ( (len = read(src, buffer, kBufferSize)) > 0 ) {
 804                 write(dst, buffer, len);
 805         }
 806
 807         // map in dst file
 808         *fileToPrebindSize = stat_buf.st_size - fOffsetInFatFile; // this may map in too much, but it does not matter
 809         *fileToPrebind = (uint8_t*)mmap(NULL, *fileToPrebindSize, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, dst, fOffsetInFatFile);
 810         if ( *fileToPrebind == (uint8_t*)(-1) )
 811                 throw "can't mmap temp image";
 812
 813         // closing notes:
 814         //              ok to close file after mapped in
 815         //              ok to throw above without closing file because the throw will terminate update_prebinding
 816         int result1 = close(dst);
 817         int result2 = close(src);
 818         if ( (result1 != 0) || (result2 != 0) )
 819                 throw "can't close file";
 820 }
 821
 822
 823 static void printTime(const char* msg, uint64_t partTime, uint64_t totalTime)
 824 {
 825         static uint64_t sUnitsPerSecond = 0;
 826         if ( sUnitsPerSecond == 0 ) {
 827                 struct mach_timebase_info timeBaseInfo;
 828                 if ( mach_timebase_info(&timeBaseInfo) == KERN_SUCCESS ) {
 829                         sUnitsPerSecond = timeBaseInfo.denom;
 830                 }
 831         }
 832         if ( partTime < sUnitsPerSecond ) {
 833                 uint32_t milliSecondsTimeTen = (partTime*10000)/sUnitsPerSecond;
 834                 uint32_t milliSeconds = milliSecondsTimeTen/10;
 835                 uint32_t percentTimesTen = (partTime*1000)/totalTime;
 836                 uint32_t percent = percentTimesTen/10;
 837                 fprintf(stderr, "%s: %u.%u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimeTen-milliSeconds*10, percent, percentTimesTen-percent*10);
 838         }
 839         else {
 840                 uint32_t secondsTimeTen = (partTime*10)/sUnitsPerSecond;
 841                 uint32_t seconds = secondsTimeTen/100;
 842                 uint32_t percentTimesTen = (partTime*1000)/totalTime;
 843                 uint32_t percent = percentTimesTen/10;
 844                 fprintf(stderr, "%s: %u.%u seconds (%u.%u%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
 845         }
 846 }
 847
 848 static char* commatize(uint64_t in, char* out)
 849 {
 850         char* result = out;
 851         char rawNum[30];
 852         sprintf(rawNum, "%llu", in);
 853         const int rawNumLen = strlen(rawNum);
 854         for(int i=0; i < rawNumLen-1; ++i) {
 855                 *out++ = rawNum[i];
 856                 if ( ((rawNumLen-i) % 3) == 1 )
 857                         *out++ = ',';
 858         }
 859         *out++ = rawNum[rawNumLen-1];
 860         *out = '\0';
 861         return result;
 862 }
 863
 864
 865 void ImageLoader::printStatistics(unsigned int imageCount)
 866 {
 867         uint64_t totalTime = fgTotalLoadLibrariesTime + fgTotalRebaseTime + fgTotalBindTime + fgTotalNotifyTime + fgTotalInitTime;
 868         char commaNum1[40];
 869         char commaNum2[40];
 870
 871         printTime("total time", totalTime, totalTime);
 872         fprintf(stderr, "total images loaded:  %d (%d used prebinding)\n", imageCount, fgImagesWithUsedPrebinding);
 873         printTime("total images loading time", fgTotalLoadLibrariesTime, totalTime);
 874         fprintf(stderr, "total rebase fixups:  %s\n", commatize(fgTotalRebaseFixups, commaNum1));
 875         printTime("total rebase fixups time", fgTotalRebaseFixups, totalTime);
 876         fprintf(stderr, "total binding fixups: %s\n", commatize(fgTotalBindFixups, commaNum1));
 877         printTime("total binding fixups time", fgTotalBindTime, totalTime);
 878         fprintf(stderr, "total bindings lazily fixed up: %s of %s\n", commatize(fgTotalLazyBindFixups, commaNum1), commatize(fgTotalPossibleLazyBindFixups, commaNum2));
 879         printTime("total notify time time", fgTotalNotifyTime, totalTime);
 880         printTime("total init time time", fgTotalInitTime, totalTime);
 881 }
 882
 883
 884 //
 885 // copy path and add suffix to result
 886 //
 887 //  /path/foo.dylib             _debug   =>   /path/foo_debug.dylib
 888 //  foo.dylib                   _debug   =>   foo_debug.dylib
 889 //  foo                         _debug   =>   foo_debug
 890 //  /path/bar                   _debug   =>   /path/bar_debug
 891 //  /path/bar.A.dylib   _debug   =>   /path/bar.A_debug.dylib
 892 //
 893 void ImageLoader::addSuffix(const char* path, const char* suffix, char* result)
 894 {
 895         strcpy(result, path);
 896
 897         char* start = strrchr(result, '/');
 898         if ( start != NULL )
 899                 start++;
 900         else
 901                 start = result;
 902
 903         char* dot = strrchr(start, '.');
 904         if ( dot != NULL ) {
 905                 strcpy(dot, suffix);
 906                 strcat(&dot[strlen(suffix)], &path[dot-result]);
 907         }
 908         else {
 909                 strcat(result, suffix);
 910         }
 911 }
 912
 913
 914 void Segment::map(int fd, uint64_t offsetInFatWrapper, intptr_t slide, const ImageLoader::LinkContext& context)
 915 {
 916         vm_offset_t fileOffset = this->getFileOffset() + offsetInFatWrapper;
 917         vm_size_t size = this->getFileSize();
 918         void* requestedLoadAddress = (void*)(this->getPreferredLoadAddress() + slide);
 919         int protection = 0;
 920         if ( !this->unaccessible() ) {
 921                 if ( this->executable() )
 922                         protection   |= PROT_EXEC;
 923                 if ( this->readable() )
 924                         protection   |= PROT_READ;
 925                 if ( this->writeable() )
 926                         protection   |= PROT_WRITE;
 927         }
 928         void* loadAddress = mmap(requestedLoadAddress, size, protection, MAP_FILE | MAP_FIXED | MAP_PRIVATE, fd, fileOffset);
 929         if ( loadAddress == ((void*)(-1)) )
 930                 throwf("mmap() error %d at address=0x%08lX, size=0x%08lX in Segment::map() mapping %s", errno, (uintptr_t)requestedLoadAddress, (uintptr_t)size, this->getImage()->getPath());
 931
 932         if ( context.verboseMapping )
 933                 fprintf(stderr, "%18s at %p->%p\n", this->getName(), loadAddress, (char*)loadAddress+this->getFileSize()-1);
 934 }
 935
 936 void Segment::map(const void* memoryImage, intptr_t slide, const ImageLoader::LinkContext& context)
 937 {
 938         vm_address_t loadAddress = this->getPreferredLoadAddress() + slide;
 939         vm_address_t srcAddr = (uintptr_t)memoryImage + this->getFileOffset();
 940         vm_size_t size = this->getFileSize();
 941         kern_return_t r = vm_copy(mach_task_self(), srcAddr, size, loadAddress);
 942         if ( r != KERN_SUCCESS )
 943                 throw "can't map segment";
 944
 945         if ( context.verboseMapping )
 946                 fprintf(stderr, "%18s at %p->%p\n", this->getName(), (char*)loadAddress, (char*)loadAddress+this->getFileSize()-1);
 947 }
 948
 949 void Segment::setPermissions()
 950 {
 951         vm_prot_t protection = 0;
 952         if ( !this->unaccessible() ) {
 953                 if ( this->executable() )
 954                         protection   |= VM_PROT_EXECUTE;
 955                 if ( this->readable() )
 956                         protection   |= VM_PROT_READ;
 957                 if ( this->writeable() )
 958                         protection   |= VM_PROT_WRITE;
 959         }
 960         vm_address_t addr = this->getActualLoadAddress();
 961         vm_size_t size = this->getSize();
 962         const bool setCurrentPermissions = false;
 963         kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, protection);
 964         if ( r != KERN_SUCCESS )
 965                 throw "can't set vm permissions for mapped segment";
 966 }
 967
 968 void Segment::tempWritable()
 969 {
 970         vm_address_t addr = this->getActualLoadAddress();
 971         vm_size_t size = this->getSize();
 972         const bool setCurrentPermissions = false;
 973         kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, VM_PROT_WRITE | VM_PROT_READ);
 974         if ( r != KERN_SUCCESS )
 975                 throw "can't set vm permissions for mapped segment";
 976 }
 977
 978
 979 bool Segment::hasTrailingZeroFill()
 980 {
 981         return ( this->writeable() && (this->getSize() > this->getFileSize()) );
 982 }
 983
 984
 985 uintptr_t Segment::reserveAnAddressRange(size_t length, const ImageLoader::LinkContext& context)
 986 {
 987         vm_address_t addr = 0;
 988         vm_size_t size = length;
 989         if ( context.slideAndPackDylibs ) {
 990                 addr = (fgNextNonSplitSegAddress - length) & (-4096); // page align
 991                 kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*use this range*/);
 992                 if ( r != KERN_SUCCESS )
 993                         throw "out of address space";
 994                 fgNextNonSplitSegAddress = addr;
 995         }
 996         else {
 997                 kern_return_t r = vm_allocate(mach_task_self(), &addr, size, true /*find range*/);
 998                 if ( r != KERN_SUCCESS )
 999                         throw "out of address space";
1000         }
1001         return addr;
1002 }
1003
1004 bool Segment::reserveAddressRange(uintptr_t start, size_t length)
1005 {
1006         vm_address_t addr = start;
1007         vm_size_t size = length;
1008         kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
1009         if ( r != KERN_SUCCESS )
1010                 return false;
1011         return true;
1012 }
1013
1014
1015