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 #include <sys/param.h>
  35 #include <sys/mount.h>
  36
  37 #include "ImageLoader.h"
  38
  39
  40 uint32_t                                                                ImageLoader::fgImagesWithUsedPrebinding = 0;
  41 uint32_t                                                                ImageLoader::fgTotalRebaseFixups = 0;
  42 uint32_t                                                                ImageLoader::fgTotalBindFixups = 0;
  43 uint32_t                                                                ImageLoader::fgTotalLazyBindFixups = 0;
  44 uint32_t                                                                ImageLoader::fgTotalPossibleLazyBindFixups = 0;
  45 uint64_t                                                                ImageLoader::fgTotalLoadLibrariesTime;
  46 uint64_t                                                                ImageLoader::fgTotalRebaseTime;
  47 uint64_t                                                                ImageLoader::fgTotalBindTime;
  48 uint64_t                                                                ImageLoader::fgTotalNotifyTime;
  49 uint64_t                                                                ImageLoader::fgTotalInitTime;
  50 uintptr_t                                                               ImageLoader::fgNextSplitSegAddress = 0x90000000;
  51 uintptr_t                                                               Segment::fgNextNonSplitSegAddress = 0x8FE00000;
  52
  53
  54
  55 __attribute__((noreturn))
  56 void throwf(const char* format, ...)
  57 {
  58         va_list list;
  59         char*   p;
  60         va_start(list, format);
  61         vasprintf(&p, format, list);
  62         va_end(list);
  63
  64         const char*     t = p;
  65         throw t;
  66 }
  67
  68 void ImageLoader::init(const char* path, uint64_t offsetInFat, dev_t device, ino_t inode, time_t modDate)
  69 {
  70         fPathHash = 0;
  71         fPath = NULL;
  72         if ( path != NULL )
  73                 this->setPath(path);
  74         fLogicalPath = NULL;
  75         fDevice = device;
  76         fInode = inode;
  77         fLastModified = modDate;
  78         fOffsetInFatFile = offsetInFat;
  79         //fSegments = NULL;
  80         fLibraries = NULL;
  81         fLibrariesCount = 0;
  82         fReferenceCount = 0;
  83         fAllLibraryChecksumsAndLoadAddressesMatch = false;
  84         fLeaveMapped = false;
  85         fHideSymbols = false;
  86         fMatchByInstallName = false;
  87         fLibrariesLoaded = false;
  88         fBased = false;
  89         fBoundAllNonLazy = false;
  90         fBoundAllLazy = false;
  91         fAnnounced = false;
  92         fInitialized = false;
  93         fNextAddImageIndex = 0;
  94 }
  95
  96
  97 ImageLoader::ImageLoader(const char* path, uint64_t offsetInFat, const struct stat& info)
  98 {
  99         init(path, offsetInFat, info.st_dev, info.st_ino, info.st_mtime);
 100 }
 101
 102 ImageLoader::ImageLoader(const char* moduleName)
 103 {
 104         init(moduleName, 0, 0, 0, 0);
 105 }
 106
 107
 108 ImageLoader::~ImageLoader()
 109 {
 110         // need to read up on STL and see if this is right way to destruct vector contents
 111         const unsigned int segmentCount = fSegments.size();
 112         for(unsigned int i=0; i < segmentCount; ++i){
 113                 Segment* seg = fSegments[i];
 114                 delete seg;
 115         }
 116         if ( fPath != NULL )
 117                 delete [] fPath;
 118         if ( fLogicalPath != NULL )
 119                 delete [] fLogicalPath;
 120 }
 121
 122
 123 void ImageLoader::setPath(const char* path)
 124 {
 125         if ( fPath != NULL ) {
 126                 // if duplicate path, do nothing
 127                 if ( strcmp(path, fPath) == 0 )
 128                         return;
 129                 delete [] fPath;
 130         }
 131         fPath = new char[strlen(path)+1];
 132         strcpy((char*)fPath, path);
 133         fPathHash = hash(fPath);
 134 }
 135
 136 void ImageLoader::setLogicalPath(const char* path)
 137 {
 138         if ( fPath == NULL ) {
 139                 // no physical path set yet, so use this path as physical
 140                 this->setPath(path);
 141         }
 142         else if ( strcmp(path, fPath) == 0 ) {
 143                 // do not set logical path because it is the same as the physical path
 144                 fLogicalPath = NULL;
 145         }
 146         else {
 147                 fLogicalPath = new char[strlen(path)+1];
 148                 strcpy((char*)fLogicalPath, path);
 149         }
 150 }
 151
 152 const char* ImageLoader::getLogicalPath() const
 153 {
 154         if ( fLogicalPath != NULL )
 155                 return fLogicalPath;
 156         else
 157                 return fPath;
 158 }
 159
 160 uint32_t ImageLoader::hash(const char* path)
 161 {
 162         // this does not need to be a great hash
 163         // it is just used to reduce the number of strcmp() calls
 164         // of existing images when loading a new image
 165         uint32_t h = 0;
 166         for (const char* s=path; *s != '\0'; ++s)
 167                 h = h*5 + *s;
 168         return h;
 169 }
 170
 171 bool ImageLoader::matchInstallPath() const
 172 {
 173         return fMatchByInstallName;
 174 }
 175
 176 void ImageLoader::setMatchInstallPath(bool match)
 177 {
 178         fMatchByInstallName = match;
 179 }
 180
 181 bool ImageLoader::statMatch(const struct stat& stat_buf) const
 182 {
 183         return ( (this->fDevice == stat_buf.st_dev) && (this->fInode == stat_buf.st_ino) );
 184 }
 185
 186 const char* ImageLoader::getShortName() const
 187 {
 188         // try to return leaf name
 189         if ( fPath != NULL ) {
 190                 const char* s = strrchr(fPath, '/');
 191                 if ( s != NULL )
 192                         return &s[1];
 193         }
 194         return fPath;
 195 }
 196
 197 uint64_t ImageLoader::getOffsetInFatFile() const
 198 {
 199         return fOffsetInFatFile;
 200 }
 201
 202 void ImageLoader::setLeaveMapped()
 203 {
 204         fLeaveMapped = true;
 205         const unsigned int segmentCount = fSegments.size();
 206         for(unsigned int i=0; i < segmentCount; ++i){
 207                 fSegments[i]->setUnMapWhenDestructed(false);
 208         }
 209 }
 210
 211 void ImageLoader::setHideExports(bool hide)
 212 {
 213         fHideSymbols = hide;
 214 }
 215
 216 bool ImageLoader::hasHiddenExports() const
 217 {
 218         return fHideSymbols;
 219 }
 220
 221 bool ImageLoader::isLinked() const
 222 {
 223         return fBoundAllNonLazy;
 224 }
 225
 226 time_t ImageLoader::lastModified()
 227 {
 228         return fLastModified;
 229 }
 230
 231 bool ImageLoader::containsAddress(const void* addr) const
 232 {
 233         const unsigned int segmentCount = fSegments.size();
 234         for(unsigned int i=0; i < segmentCount; ++i){
 235                 Segment* seg = fSegments[i];
 236                 const uint8_t* start = (const uint8_t*)seg->getActualLoadAddress();
 237                 const uint8_t* end = start + seg->getSize();
 238                 if ( (start <= addr) && (addr < end) && !seg->unaccessible() )
 239                         return true;
 240         }
 241         return false;
 242 }
 243
 244 void ImageLoader::addMappedRegions(RegionsVector& regions) const
 245 {
 246         const unsigned int segmentCount = fSegments.size();
 247         for(unsigned int i=0; i < segmentCount; ++i){
 248                 Segment* seg = fSegments[i];
 249                 MappedRegion region;
 250                 region.address = seg->getActualLoadAddress();
 251                 region.size = seg->getSize();
 252                 regions.push_back(region);
 253         }
 254 }
 255
 256
 257 void ImageLoader::incrementReferenceCount()
 258 {
 259         ++fReferenceCount;
 260 }
 261
 262 bool ImageLoader::decrementReferenceCount()
 263 {
 264         return ( --fReferenceCount == 0 );
 265 }
 266
 267 // private method that handles circular dependencies by only search any image once
 268 const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImagesExcept(const char* name, std::set<const ImageLoader*>& dontSearchImages, ImageLoader** foundIn) const
 269 {
 270         const ImageLoader::Symbol* sym;
 271         // search self
 272         if ( dontSearchImages.count(this) == 0 ) {
 273                 sym = this->findExportedSymbol(name, NULL, false, foundIn);
 274                 if ( sym != NULL )
 275                         return sym;
 276                 dontSearchImages.insert(this);
 277         }
 278
 279         // search directly dependent libraries
 280         for (uint32_t i=0; i < fLibrariesCount; ++i) {
 281                 ImageLoader* dependentImage = fLibraries[i].image;
 282                 if ( (dependentImage != NULL) && (dontSearchImages.count(dependentImage) == 0) ) {
 283                         const ImageLoader::Symbol* sym = dependentImage->findExportedSymbol(name, NULL, false, foundIn);
 284                         if ( sym != NULL )
 285                                 return sym;
 286                 }
 287         }
 288
 289         // search indirectly dependent libraries
 290         for (uint32_t i=0; i < fLibrariesCount; ++i) {
 291                 ImageLoader* dependentImage = fLibraries[i].image;
 292                 if ( (dependentImage != NULL) && (dontSearchImages.count(dependentImage) == 0) ) {
 293                         const ImageLoader::Symbol* sym = dependentImage->findExportedSymbolInDependentImagesExcept(name, dontSearchImages, foundIn);
 294                         if ( sym != NULL )
 295                                 return sym;
 296                         dontSearchImages.insert(dependentImage);
 297                 }
 298         }
 299
 300         return NULL;
 301 }
 302
 303
 304 const ImageLoader::Symbol* ImageLoader::findExportedSymbolInDependentImages(const char* name, ImageLoader** foundIn) const
 305 {
 306         std::set<const ImageLoader*> dontSearchImages;
 307         dontSearchImages.insert(this);  // don't search this image
 308         return this->findExportedSymbolInDependentImagesExcept(name, dontSearchImages, foundIn);
 309 }
 310
 311 const ImageLoader::Symbol* ImageLoader::findExportedSymbolInImageOrDependentImages(const char* name, ImageLoader** foundIn) const
 312 {
 313         std::set<const ImageLoader*> dontSearchImages;
 314         return this->findExportedSymbolInDependentImagesExcept(name, dontSearchImages, foundIn);
 315 }
 316
 317
 318 void ImageLoader::link(const LinkContext& context, BindingLaziness bindness, InitializerRunning inits, uint32_t notifyCount)
 319 {
 320         uint64_t t1 = mach_absolute_time();
 321         this->recursiveLoadLibraries(context);
 322
 323         uint64_t t2 = mach_absolute_time();
 324         this->recursiveRebase(context);
 325
 326         uint64_t t3 = mach_absolute_time();
 327         this->recursiveBind(context, bindness);
 328
 329         uint64_t t4 = mach_absolute_time();
 330         this->recursiveImageNotification(context, notifyCount);
 331
 332         if ( (inits == kRunInitializers) || (inits == kDontRunInitializersButTellObjc) ) {
 333                 std::vector<ImageLoader*>       newImages;
 334                 this->recursiveImageAnnouncement(context, newImages);    // build bottom up list images being added
 335                 context.notifyAdding(newImages);        // tell gdb or anyone who cares about these
 336         }
 337
 338         uint64_t t5 = mach_absolute_time();
 339         if ( inits == kRunInitializers ) {
 340                 this->recursiveInitialization(context);
 341                 uint64_t t6 = mach_absolute_time();
 342                 fgTotalInitTime += t6 - t5;
 343         }
 344         fgTotalLoadLibrariesTime += t2 - t1;
 345         fgTotalRebaseTime += t3 - t2;
 346         fgTotalBindTime += t4 - t3;
 347         fgTotalNotifyTime += t5 - t4;
 348 }
 349
 350
 351 // only called pre-main on main executable
 352 // if crt.c is ever cleaned up, this could go away
 353 void ImageLoader::runInitializers(const LinkContext& context)
 354 {
 355                 std::vector<ImageLoader*>       newImages;
 356                 this->recursiveImageAnnouncement(context, newImages);    // build bottom up list images being added
 357                 context.notifyAdding(newImages);        // tell gdb or anyone who cares about these
 358
 359         this->recursiveInitialization(context);
 360 }
 361
 362 // called inside _dyld_register_func_for_add_image()
 363 void ImageLoader::runNotification(const LinkContext& context, uint32_t notifyCount)
 364 {
 365         this->recursiveImageNotification(context, notifyCount);
 366 }
 367
 368
 369 intptr_t ImageLoader::assignSegmentAddresses(const LinkContext& context)
 370 {
 371         // preflight and calculate slide if needed
 372         const unsigned int segmentCount = fSegments.size();
 373         intptr_t slide = 0;
 374         if ( this->segmentsCanSlide() && this->segmentsMustSlideTogether() ) {
 375                 bool needsToSlide = false;
 376                 uintptr_t lowAddr = UINTPTR_MAX;
 377                 uintptr_t highAddr = 0;
 378                 for(unsigned int i=0; i < segmentCount; ++i){
 379                         Segment* seg = fSegments[i];
 380                         const uintptr_t segLow = seg->getPreferredLoadAddress();
 381                         const uintptr_t segHigh = segLow + seg->getSize();
 382                         if ( segLow < lowAddr )
 383                                 lowAddr = segLow;
 384                         if ( segHigh > highAddr )
 385                                 highAddr = segHigh;
 386
 387                         if ( context.slideAndPackDylibs || !seg->hasPreferredLoadAddress() || !Segment::reserveAddressRange(seg->getPreferredLoadAddress(), seg->getSize()) )
 388                                 needsToSlide = true;
 389                 }
 390                 if ( needsToSlide ) {
 391                         // find a chunk of address space to hold all segments
 392                         uintptr_t addr = Segment::reserveAnAddressRange(highAddr-lowAddr, context);
 393                         slide = addr - lowAddr;
 394                 }
 395         }
 396         else if ( ! this->segmentsCanSlide() ) {
 397                 for(unsigned int i=0; i < segmentCount; ++i){
 398                         Segment* seg = fSegments[i];
 399                         if ( strcmp(seg->getName(), "__PAGEZERO") == 0 )
 400                                 continue;
 401                         if ( !Segment::reserveAddressRange(seg->getPreferredLoadAddress(), seg->getSize()) )
 402                                 throw "can't map";
 403                 }
 404         }
 405         else {
 406                 // mach-o does not support independently sliding segments
 407         }
 408         return slide;
 409 }
 410
 411
 412 void ImageLoader::mapSegments(int fd, uint64_t offsetInFat, uint64_t lenInFat, uint64_t fileLen, const LinkContext& context)
 413 {
 414         if ( context.verboseMapping )
 415                 fprintf(stderr, "dyld: Mapping %s\n", this->getPath());
 416         // find address range for image
 417         intptr_t slide = this->assignSegmentAddresses(context);
 418         // map in all segments
 419         const unsigned int segmentCount = fSegments.size();
 420         for(unsigned int i=0; i < segmentCount; ++i){
 421                 Segment* seg = fSegments[i];
 422                 seg->map(fd, offsetInFat, slide, context);
 423         }
 424         // update slide to reflect load location
 425         this->setSlide(slide);
 426
 427         // now that it is mapped and slide is set, mark that we should unmap it when done
 428         for(unsigned int i=0; i < segmentCount; ++i){
 429                 fSegments[i]->setUnMapWhenDestructed(true);
 430         }
 431 }
 432
 433 void ImageLoader::mapSegments(const void* memoryImage, uint64_t imageLen, const LinkContext& context)
 434 {
 435         if ( context.verboseMapping )
 436                 fprintf(stderr, "dyld: Mapping memory %p\n", memoryImage);
 437         // find address range for image
 438         intptr_t slide = this->assignSegmentAddresses(context);
 439         // map in all segments
 440         const unsigned int segmentCount = fSegments.size();
 441         for(unsigned int i=0; i < segmentCount; ++i){
 442                 Segment* seg = fSegments[i];
 443                 seg->map(memoryImage, slide, context);
 444         }
 445         // update slide to reflect load location
 446         this->setSlide(slide);
 447         // set R/W permissions on all segments at slide location
 448         for(unsigned int i=0; i < segmentCount; ++i){
 449                 Segment* seg = fSegments[i];
 450                 seg->setPermissions();
 451         }
 452 }
 453
 454 bool ImageLoader::allDependentLibrariesAsWhenPreBound() const
 455 {
 456         return fAllLibraryChecksumsAndLoadAddressesMatch;
 457 }
 458
 459
 460 void ImageLoader::recursiveLoadLibraries(const LinkContext& context)
 461 {
 462         if ( ! fLibrariesLoaded ) {
 463                 // break cycles
 464                 fLibrariesLoaded = true;
 465
 466                 // get list of libraries this image needs
 467                 fLibrariesCount = this->doGetDependentLibraryCount();
 468                 fLibraries = new DependentLibrary[fLibrariesCount];
 469                 this->doGetDependentLibraries(fLibraries);
 470
 471                 // try to load each
 472                 bool canUsePrelinkingInfo = true;
 473                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 474                         DependentLibrary& requiredLib = fLibraries[i];
 475                         try {
 476                                 requiredLib.image = context.loadLibrary(requiredLib.name, true, this->getPath(), NULL);
 477                                 if ( requiredLib.image == this ) {
 478                                         // found circular reference, perhaps DYLD_LIBARY_PATH is causing this rdar://problem/3684168
 479                                         requiredLib.image = context.loadLibrary(requiredLib.name, false, NULL, NULL);
 480                                         if ( requiredLib.image != this )
 481                                                 fprintf(stderr, "dyld: warning DYLD_ setting caused circular dependency in %s\n", this->getPath());
 482                                 }
 483                                 LibraryInfo actualInfo = requiredLib.image->doGetLibraryInfo();
 484                                 requiredLib.checksumMatches = ( actualInfo.checksum == requiredLib.info.checksum );
 485                                 // check found library version is compatible
 486                                 if ( actualInfo.minVersion < requiredLib.info.minVersion ) {
 487                                         throwf("Incompatible library version: %s requires version %d.%d.%d or later, but %s provides version %d.%d.%d",
 488                                                         this->getShortName(), requiredLib.info.minVersion >> 16, (requiredLib.info.minVersion >> 8) & 0xff, requiredLib.info.minVersion & 0xff,
 489                                                         requiredLib.image->getShortName(), actualInfo.minVersion >> 16, (actualInfo.minVersion >> 8) & 0xff, actualInfo.minVersion & 0xff);
 490                                 }
 491                                 // prebinding for this image disabled if any dependent library changed or slid
 492                                 if ( !requiredLib.checksumMatches || (requiredLib.image->getSlide() != 0) )
 493                                         canUsePrelinkingInfo = false;
 494                                 //if ( context.verbosePrebinding ) {
 495                                 //      if ( !requiredLib.checksumMatches )
 496                                 //              fprintf(stderr, "dyld: checksum mismatch, (%lld v %lld) for %s referencing %s\n", requiredLib.info.checksum, actualInfo.checksum, this->getPath(),      requiredLib.image->getPath());
 497                                 //      if ( requiredLib.image->getSlide() != 0 )
 498                                 //              fprintf(stderr, "dyld: dependent library slid for %s referencing %s\n", this->getPath(), requiredLib.image->getPath());
 499                                 //}
 500                         }
 501                         catch (const char* msg) {
 502                                 //if ( context.verbosePrebinding )
 503                                 //      fprintf(stderr, "dyld: exception during processing for %s referencing %s\n", this->getPath(), requiredLib.image->getPath());
 504                                 if ( requiredLib.required ) {
 505                                         const char* formatString = "Library not loaded: %s\n  Referenced from: %s\n  Reason: %s";
 506                                         const char* referencedFrom = this->getPath();
 507                                         char buf[strlen(requiredLib.name)+strlen(referencedFrom)+strlen(formatString)+strlen(msg)+2];
 508                                         sprintf(buf, formatString, requiredLib.name, referencedFrom, msg);
 509                                         fLibrariesLoaded = false;
 510                                         throw strdup(buf);  // this is a leak if exception doesn't halt program
 511                                 }
 512                                 // ok if weak library not found
 513                                 requiredLib.image = NULL;
 514                                 canUsePrelinkingInfo = false;  // this disables all prebinding, we may want to just slam import vectors for this lib to zero
 515                         }
 516                 }
 517                 fAllLibraryChecksumsAndLoadAddressesMatch = canUsePrelinkingInfo;
 518
 519                 // tell each to load its dependents
 520                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 521                         DependentLibrary& libInfo = fLibraries[i];
 522                         if ( libInfo.image != NULL ) {
 523                                 libInfo.isSubFramework = libInfo.image->isSubframeworkOf(context, this);
 524                                 libInfo.isReExported = libInfo.isSubFramework || this->hasSubLibrary(context, libInfo.image);
 525                                 //if ( libInfo.isReExported  )
 526                                 //      fprintf(stderr, "%s re-exports %s\n", strrchr(this->getPath(), '/'), strrchr(libInfo.image->getPath(),'/'));
 527                                 libInfo.image->recursiveLoadLibraries(context);
 528                         }
 529                 }
 530
 531                 // do deep prebind check
 532                 if ( fAllLibraryChecksumsAndLoadAddressesMatch ) {
 533                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 534                                 const DependentLibrary& libInfo = fLibraries[i];
 535                                 if ( libInfo.image != NULL ) {
 536                                         if ( !libInfo.image->allDependentLibrariesAsWhenPreBound() )
 537                                                 fAllLibraryChecksumsAndLoadAddressesMatch = false;
 538                                 }
 539                         }
 540                 }
 541
 542         }
 543 }
 544
 545 void ImageLoader::recursiveRebase(const LinkContext& context)
 546 {
 547         if ( ! fBased ) {
 548                 // break cycles
 549                 fBased = true;
 550
 551                 try {
 552                         // rebase lower level libraries first
 553                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 554                                 DependentLibrary& libInfo = fLibraries[i];
 555                                 if ( libInfo.image != NULL )
 556                                         libInfo.image->recursiveRebase(context);
 557                         }
 558
 559                         // rebase this image
 560                         doRebase(context);
 561                 }
 562                 catch (const char* msg) {
 563                         // this image is not rebased
 564                         fBased = false;
 565                         throw msg;
 566                 }
 567         }
 568 }
 569
 570
 571
 572
 573 void ImageLoader::recursiveBind(const LinkContext& context, BindingLaziness bindness)
 574 {
 575         // normally just non-lazy pointers are bound up front,
 576         // but DYLD_BIND_AT_LAUNCH will cause lazy pointers to be bound up from
 577         // and some dyld API's bind all lazys at runtime
 578         bool nonLazy = false;
 579         bool lazy = false;
 580         switch( bindness ) {
 581                 case kNonLazyOnly:
 582                         nonLazy = true;
 583                         break;
 584                 case kLazyAndNonLazy:
 585                         nonLazy = true;
 586                         lazy = true;
 587                         break;
 588                 case kLazyOnly:
 589                 case kLazyOnlyNoDependents:
 590                         lazy = true;
 591                         break;
 592         }
 593         const bool doNonLazy = nonLazy && !fBoundAllNonLazy;
 594         const bool doLazy = lazy && !fBoundAllLazy;
 595         if ( doNonLazy || doLazy ) {
 596                 // break cycles
 597                 bool oldBoundAllNonLazy = fBoundAllNonLazy;
 598                 bool oldBoundAllLazy = fBoundAllLazy;
 599                 fBoundAllNonLazy = fBoundAllNonLazy || nonLazy;
 600                 fBoundAllLazy = fBoundAllLazy || lazy;
 601
 602                 try {
 603                         // bind lower level libraries first
 604                         if ( bindness != kLazyOnlyNoDependents ) {
 605                                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 606                                         DependentLibrary& libInfo = fLibraries[i];
 607                                         if ( libInfo.image != NULL )
 608                                                 libInfo.image->recursiveBind(context, bindness);
 609                                 }
 610                         }
 611                         // bind this image
 612                         if ( doLazy && !doNonLazy )
 613                                 doBind(context, kLazyOnly);
 614                         else if ( !doLazy && doNonLazy )
 615                                 doBind(context, kNonLazyOnly);
 616                         else
 617                                 doBind(context, kLazyAndNonLazy);
 618                 }
 619                 catch (const char* msg) {
 620                         // restore state
 621                         fBoundAllNonLazy = oldBoundAllNonLazy;
 622                         fBoundAllLazy = oldBoundAllLazy;
 623                         throw msg;
 624                 }
 625         }
 626 }
 627
 628 //
 629 // This is complex because _dyld_register_func_for_add_image() is defined to not only
 630 // notify you of future image loads, but also of all currently loaded images.  Therefore
 631 // each image needs to track that all add-image-funcs have been notified about it.
 632 // Since add-image-funcs cannot be removed, each has a unique index and each image
 633 // records the thru which index notificiation has already been done.
 634 //
 635 void ImageLoader::recursiveImageNotification(const LinkContext& context, uint32_t addImageCount)
 636 {
 637         if ( fNextAddImageIndex < addImageCount ) {
 638                 // break cycles
 639                 const uint32_t initIndex = fNextAddImageIndex;
 640                 fNextAddImageIndex = addImageCount;
 641
 642                 // notify all requestors about this image
 643                 context.imageNotification(this, initIndex);
 644
 645                 // notify about lower level libraries first
 646                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 647                         DependentLibrary& libInfo = fLibraries[i];
 648                         if ( libInfo.image != NULL )
 649                                 libInfo.image->recursiveImageNotification(context, addImageCount);
 650                 }
 651         }
 652 }
 653
 654
 655 void ImageLoader::recursiveImageAnnouncement(const LinkContext& context, std::vector<ImageLoader*>& newImages)
 656 {
 657         if ( ! fAnnounced ) {
 658                 // break cycles
 659                 fAnnounced = true;
 660
 661                 // announce lower level libraries first
 662                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 663                         DependentLibrary& libInfo = fLibraries[i];
 664                         if ( libInfo.image != NULL )
 665                                 libInfo.image->recursiveImageAnnouncement(context, newImages);
 666                 }
 667
 668                 // add to list of images to notify gdb about
 669                 newImages.push_back(this);
 670                 //fprintf(stderr, "next size = %d\n", newImages.size());
 671
 672                 // remember that this image wants to be notified about other images
 673                  if ( this->hasImageNotification() )
 674                         context.addImageNeedingNotification(this);
 675         }
 676 }
 677
 678
 679
 680 void ImageLoader::recursiveInitialization(const LinkContext& context)
 681 {
 682         if ( ! fInitialized ) {
 683                 // break cycles
 684                 fInitialized = true;
 685
 686                 try {
 687                         // initialize lower level libraries first
 688                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 689                                 DependentLibrary& libInfo = fLibraries[i];
 690                                 if ( libInfo.image != NULL )
 691                                         libInfo.image->recursiveInitialization(context);
 692                         }
 693
 694                         // record termination order
 695                         if ( this->needsTermination() )
 696                                 context.terminationRecorder(this);
 697
 698                         // initialize this image
 699                         this->doInitialization(context);
 700                 }
 701                 catch (const char* msg) {
 702                         // this image is not initialized
 703                         fInitialized = false;
 704                         throw msg;
 705                 }
 706         }
 707 }
 708
 709 void ImageLoader::reprebindCommit(const LinkContext& context, bool commit, bool unmapOld)
 710 {
 711         // do nothing on unprebound images
 712         if ( ! this->isPrebindable() )
 713                 return;
 714
 715         // do nothing if prebinding is up to date
 716         if ( this->usablePrebinding(context) )
 717                 return;
 718
 719         // make sure we are not replacing a symlink with a file
 720         char realFilePath[PATH_MAX];
 721         if ( realpath(this->getPath(), realFilePath) == NULL ) {
 722                 throwf("realpath() failed on %s, errno=%d", this->getPath(), errno);
 723         }
 724         // recreate temp file name
 725         char tempFilePath[strlen(realFilePath)+strlen("_redoprebinding")+2];
 726         ImageLoader::addSuffix(realFilePath, "_redoprebinding", tempFilePath);
 727
 728         if ( commit ) {
 729                 // all files successfully reprebound, so do swap
 730                 int result = rename(tempFilePath, realFilePath);
 731                 if ( result != 0 ) {
 732                         // if there are two dylibs with the same install path, the second will fail to prebind
 733                         // because the _redoprebinding temp file is gone.  In that case, log and go on.
 734                         if ( errno == ENOENT )
 735                                 fprintf(stderr, "update_prebinding: temp file missing: %s\n", tempFilePath);
 736                         else
 737                                 throwf("can't swap temporary re-prebound file: rename(%s,%s) returned errno=%d", tempFilePath, realFilePath, errno);
 738                 }
 739                 else if ( unmapOld ) {
 740                         this->prebindUnmap(context);
 741                 }
 742         }
 743         else {
 744                 // something went wrong during prebinding, delete the temp files
 745                 unlink(tempFilePath);
 746         }
 747 }
 748
 749 uint64_t ImageLoader::reprebind(const LinkContext& context, time_t timestamp)
 750 {
 751         // do nothing on unprebound images
 752         if ( ! this->isPrebindable() )
 753                 return INT64_MAX;
 754
 755         // do nothing if prebinding is up to date
 756         if ( this->usablePrebinding(context) ) {
 757                 if ( context.verbosePrebinding )
 758                         fprintf(stderr, "dyld: no need to re-prebind: %s\n", this->getPath());
 759                 return INT64_MAX;
 760         }
 761         // recreate temp file name
 762         char realFilePath[PATH_MAX];
 763         if ( realpath(this->getPath(), realFilePath) == NULL ) {
 764                 throwf("realpath() failed on %s, errno=%d", this->getPath(), errno);
 765         }
 766         char tempFilePath[strlen(realFilePath)+strlen("_redoprebinding")+2];
 767         ImageLoader::addSuffix(realFilePath, "_redoprebinding", tempFilePath);
 768
 769         // make copy of file and map it in
 770         uint8_t* fileToPrebind;
 771         uint64_t fileToPrebindSize;
 772         uint64_t freespace = this->copyAndMap(tempFilePath, &fileToPrebind, &fileToPrebindSize);
 773
 774         // do format specific prebinding
 775         this->doPrebinding(context, timestamp, fileToPrebind);
 776
 777         // flush and swap files
 778         int result = msync(fileToPrebind, fileToPrebindSize, MS_ASYNC);
 779         if ( result != 0 )
 780                 throw "error syncing re-prebound file";
 781         result = munmap(fileToPrebind, fileToPrebindSize);
 782         if ( result != 0 )
 783                 throw "error unmapping re-prebound file";
 784
 785         // log
 786         if ( context.verbosePrebinding )
 787                 fprintf(stderr, "dyld: re-prebound: %p %s\n", this->machHeader(), this->getPath());
 788
 789         return freespace;
 790 }
 791
 792 uint64_t ImageLoader::copyAndMap(const char* tempFile, uint8_t** fileToPrebind, uint64_t* fileToPrebindSize)
 793 {
 794         // reopen dylib
 795         int src = open(this->getPath(), O_RDONLY);
 796         if ( src == -1 )
 797                 throw "can't open image";
 798         struct stat stat_buf;
 799         if ( fstat(src, &stat_buf) == -1)
 800                 throw "can't stat image";
 801         if ( stat_buf.st_mtime != fLastModified )
 802                 throw "image file changed since it was loaded";
 803
 804         // create new file with all same permissions to hold copy of dylib
 805         unlink(tempFile);
 806         int dst = open(tempFile, O_CREAT | O_RDWR | O_TRUNC, stat_buf.st_mode);
 807         if ( dst == -1 )
 808                 throw "can't create temp image";
 809
 810         // mark source as "don't cache"
 811         (void)fcntl(src, F_NOCACHE, 1);
 812         // we want to cache the dst because we are about to map it in and modify it
 813
 814         // copy permission bits
 815         if ( chmod(tempFile, stat_buf.st_mode & 07777) == -1 )
 816                 throwf("can't chmod temp image.  errno=%d for %s", errno, this->getPath());
 817         if ( chown(tempFile, stat_buf.st_uid, stat_buf.st_gid) == -1)
 818                 throwf("can't chown temp image.  errno=%d for %s", errno, this->getPath());
 819
 820         // copy contents
 821         ssize_t len;
 822         const uint32_t kBufferSize = 128*1024;
 823         static uint8_t* buffer = NULL;
 824         if ( buffer == NULL ) {
 825                 vm_address_t addr = 0;
 826                 if ( vm_allocate(mach_task_self(), &addr, kBufferSize, true /*find range*/) == KERN_SUCCESS )
 827                         buffer = (uint8_t*)addr;
 828                 else
 829                         throw "can't allcoate copy buffer";
 830         }
 831         while ( (len = read(src, buffer, kBufferSize)) > 0 ) {
 832                 if ( write(dst, buffer, len) == -1 )
 833                         throwf("write failure copying dylib errno=%d for %s", errno, this->getPath());
 834         }
 835
 836         // map in dst file
 837         *fileToPrebindSize = stat_buf.st_size - fOffsetInFatFile; // this may map in too much, but it does not matter
 838         *fileToPrebind = (uint8_t*)mmap(NULL, *fileToPrebindSize, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, dst, fOffsetInFatFile);
 839         if ( *fileToPrebind == (uint8_t*)(-1) )
 840                 throw "can't mmap temp image";
 841
 842         // get free space remaining on dst volume
 843         struct statfs statfs_buf;
 844         if ( fstatfs(dst, &statfs_buf) != 0 )
 845                 throwf("can't fstatfs(), errno=%d for %s", errno, tempFile);
 846         uint64_t freespace = (uint64_t)statfs_buf.f_bavail * (uint64_t)statfs_buf.f_bsize;
 847
 848         // closing notes:
 849         //              ok to close file after mapped in
 850         //              ok to throw above without closing file because the throw will terminate update_prebinding
 851         int result1 = close(dst);
 852         int result2 = close(src);
 853         if ( (result1 != 0) || (result2 != 0) )
 854                 throw "can't close file";
 855
 856         return freespace;
 857 }
 858
 859
 860 static void printTime(const char* msg, uint64_t partTime, uint64_t totalTime)
 861 {
 862         static uint64_t sUnitsPerSecond = 0;
 863         if ( sUnitsPerSecond == 0 ) {
 864                 struct mach_timebase_info timeBaseInfo;
 865                 if ( mach_timebase_info(&timeBaseInfo) == KERN_SUCCESS ) {
 866                         sUnitsPerSecond = timeBaseInfo.denom;
 867                 }
 868         }
 869         if ( partTime < sUnitsPerSecond ) {
 870                 uint32_t milliSecondsTimeTen = (partTime*10000)/sUnitsPerSecond;
 871                 uint32_t milliSeconds = milliSecondsTimeTen/10;
 872                 uint32_t percentTimesTen = (partTime*1000)/totalTime;
 873                 uint32_t percent = percentTimesTen/10;
 874                 fprintf(stderr, "%s: %u.%u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimeTen-milliSeconds*10, percent, percentTimesTen-percent*10);
 875         }
 876         else {
 877                 uint32_t secondsTimeTen = (partTime*10)/sUnitsPerSecond;
 878                 uint32_t seconds = secondsTimeTen/100;
 879                 uint32_t percentTimesTen = (partTime*1000)/totalTime;
 880                 uint32_t percent = percentTimesTen/10;
 881                 fprintf(stderr, "%s: %u.%u seconds (%u.%u%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
 882         }
 883 }
 884
 885 static char* commatize(uint64_t in, char* out)
 886 {
 887         char* result = out;
 888         char rawNum[30];
 889         sprintf(rawNum, "%llu", in);
 890         const int rawNumLen = strlen(rawNum);
 891         for(int i=0; i < rawNumLen-1; ++i) {
 892                 *out++ = rawNum[i];
 893                 if ( ((rawNumLen-i) % 3) == 1 )
 894                         *out++ = ',';
 895         }
 896         *out++ = rawNum[rawNumLen-1];
 897         *out = '\0';
 898         return result;
 899 }
 900
 901
 902 void ImageLoader::printStatistics(unsigned int imageCount)
 903 {
 904         uint64_t totalTime = fgTotalLoadLibrariesTime + fgTotalRebaseTime + fgTotalBindTime + fgTotalNotifyTime + fgTotalInitTime;
 905         char commaNum1[40];
 906         char commaNum2[40];
 907
 908         printTime("total time", totalTime, totalTime);
 909         fprintf(stderr, "total images loaded:  %d (%d used prebinding)\n", imageCount, fgImagesWithUsedPrebinding);
 910         printTime("total images loading time", fgTotalLoadLibrariesTime, totalTime);
 911         fprintf(stderr, "total rebase fixups:  %s\n", commatize(fgTotalRebaseFixups, commaNum1));
 912         printTime("total rebase fixups time", fgTotalRebaseFixups, totalTime);
 913         fprintf(stderr, "total binding fixups: %s\n", commatize(fgTotalBindFixups, commaNum1));
 914         printTime("total binding fixups time", fgTotalBindTime, totalTime);
 915         fprintf(stderr, "total bindings lazily fixed up: %s of %s\n", commatize(fgTotalLazyBindFixups, commaNum1), commatize(fgTotalPossibleLazyBindFixups, commaNum2));
 916         printTime("total notify time time", fgTotalNotifyTime, totalTime);
 917         printTime("total init time time", fgTotalInitTime, totalTime);
 918 }
 919
 920
 921 //
 922 // copy path and add suffix to result
 923 //
 924 //  /path/foo.dylib             _debug   =>   /path/foo_debug.dylib
 925 //  foo.dylib                   _debug   =>   foo_debug.dylib
 926 //  foo                         _debug   =>   foo_debug
 927 //  /path/bar                   _debug   =>   /path/bar_debug
 928 //  /path/bar.A.dylib   _debug   =>   /path/bar.A_debug.dylib
 929 //
 930 void ImageLoader::addSuffix(const char* path, const char* suffix, char* result)
 931 {
 932         strcpy(result, path);
 933
 934         char* start = strrchr(result, '/');
 935         if ( start != NULL )
 936                 start++;
 937         else
 938                 start = result;
 939
 940         char* dot = strrchr(start, '.');
 941         if ( dot != NULL ) {
 942                 strcpy(dot, suffix);
 943                 strcat(&dot[strlen(suffix)], &path[dot-result]);
 944         }
 945         else {
 946                 strcat(result, suffix);
 947         }
 948 }
 949
 950
 951 void Segment::map(int fd, uint64_t offsetInFatWrapper, intptr_t slide, const ImageLoader::LinkContext& context)
 952 {
 953         vm_offset_t fileOffset = this->getFileOffset() + offsetInFatWrapper;
 954         vm_size_t size = this->getFileSize();
 955         void* requestedLoadAddress = (void*)(this->getPreferredLoadAddress() + slide);
 956         int protection = 0;
 957         if ( !this->unaccessible() ) {
 958                 if ( this->executable() )
 959                         protection   |= PROT_EXEC;
 960                 if ( this->readable() )
 961                         protection   |= PROT_READ;
 962                 if ( this->writeable() )
 963                         protection   |= PROT_WRITE;
 964         }
 965         void* loadAddress = mmap(requestedLoadAddress, size, protection, MAP_FILE | MAP_FIXED | MAP_PRIVATE, fd, fileOffset);
 966         if ( loadAddress == ((void*)(-1)) )
 967                 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());
 968
 969         if ( context.verboseMapping )
 970                 fprintf(stderr, "%18s at %p->%p\n", this->getName(), loadAddress, (char*)loadAddress+this->getFileSize()-1);
 971 }
 972
 973 void Segment::map(const void* memoryImage, intptr_t slide, const ImageLoader::LinkContext& context)
 974 {
 975         vm_address_t loadAddress = this->getPreferredLoadAddress() + slide;
 976         vm_address_t srcAddr = (uintptr_t)memoryImage + this->getFileOffset();
 977         vm_size_t size = this->getFileSize();
 978         kern_return_t r = vm_copy(mach_task_self(), srcAddr, size, loadAddress);
 979         if ( r != KERN_SUCCESS )
 980                 throw "can't map segment";
 981
 982         if ( context.verboseMapping )
 983                 fprintf(stderr, "%18s at %p->%p\n", this->getName(), (char*)loadAddress, (char*)loadAddress+this->getFileSize()-1);
 984 }
 985
 986 void Segment::setPermissions()
 987 {
 988         vm_prot_t protection = 0;
 989         if ( !this->unaccessible() ) {
 990                 if ( this->executable() )
 991                         protection   |= VM_PROT_EXECUTE;
 992                 if ( this->readable() )
 993                         protection   |= VM_PROT_READ;
 994                 if ( this->writeable() )
 995                         protection   |= VM_PROT_WRITE;
 996         }
 997         vm_address_t addr = this->getActualLoadAddress();
 998         vm_size_t size = this->getSize();
 999         const bool setCurrentPermissions = false;
1000         kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, protection);
1001         if ( r != KERN_SUCCESS )
1002                 throw "can't set vm permissions for mapped segment";
1003 }
1004
1005 void Segment::tempWritable()
1006 {
1007         vm_address_t addr = this->getActualLoadAddress();
1008         vm_size_t size = this->getSize();
1009         const bool setCurrentPermissions = false;
1010         kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, VM_PROT_WRITE | VM_PROT_READ);
1011         if ( r != KERN_SUCCESS )
1012                 throw "can't set vm permissions for mapped segment";
1013 }
1014
1015
1016 bool Segment::hasTrailingZeroFill()
1017 {
1018         return ( this->writeable() && (this->getSize() > this->getFileSize()) );
1019 }
1020
1021
1022 uintptr_t Segment::reserveAnAddressRange(size_t length, const ImageLoader::LinkContext& context)
1023 {
1024         vm_address_t addr = 0;
1025         vm_size_t size = length;
1026         if ( context.slideAndPackDylibs ) {
1027                 addr = (fgNextNonSplitSegAddress - length) & (-4096); // page align
1028                 kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*use this range*/);
1029                 if ( r != KERN_SUCCESS )
1030                         throw "out of address space";
1031                 fgNextNonSplitSegAddress = addr;
1032         }
1033         else {
1034                 kern_return_t r = vm_allocate(mach_task_self(), &addr, size, true /*find range*/);
1035                 if ( r != KERN_SUCCESS )
1036                         throw "out of address space";
1037         }
1038         return addr;
1039 }
1040
1041 bool Segment::reserveAddressRange(uintptr_t start, size_t length)
1042 {
1043         vm_address_t addr = start;
1044         vm_size_t size = length;
1045         kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
1046         if ( r != KERN_SUCCESS )
1047                 return false;
1048         return true;
1049 }
1050
1051
1052