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                                         throw strdup(buf);  // this is a leak if exception doesn't halt program
 510                                 }
 511                                 // ok if weak library not found
 512                                 requiredLib.image = NULL;
 513                                 canUsePrelinkingInfo = false;  // this disables all prebinding, we may want to just slam import vectors for this lib to zero
 514                         }
 515                 }
 516                 fAllLibraryChecksumsAndLoadAddressesMatch = canUsePrelinkingInfo;
 517
 518                 // tell each to load its dependents
 519                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 520                         DependentLibrary& libInfo = fLibraries[i];
 521                         if ( libInfo.image != NULL ) {
 522                                 libInfo.isSubFramework = libInfo.image->isSubframeworkOf(context, this);
 523                                 libInfo.isReExported = libInfo.isSubFramework || this->hasSubLibrary(context, libInfo.image);
 524                                 //if ( libInfo.isReExported  )
 525                                 //      fprintf(stderr, "%s re-exports %s\n", strrchr(this->getPath(), '/'), strrchr(libInfo.image->getPath(),'/'));
 526                                 libInfo.image->recursiveLoadLibraries(context);
 527                         }
 528                 }
 529
 530                 // do deep prebind check
 531                 if ( fAllLibraryChecksumsAndLoadAddressesMatch ) {
 532                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 533                                 const DependentLibrary& libInfo = fLibraries[i];
 534                                 if ( libInfo.image != NULL ) {
 535                                         if ( !libInfo.image->allDependentLibrariesAsWhenPreBound() )
 536                                                 fAllLibraryChecksumsAndLoadAddressesMatch = false;
 537                                 }
 538                         }
 539                 }
 540
 541         }
 542 }
 543
 544 void ImageLoader::recursiveRebase(const LinkContext& context)
 545 {
 546         if ( ! fBased ) {
 547                 // break cycles
 548                 fBased = true;
 549
 550                 try {
 551                         // rebase lower level libraries first
 552                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 553                                 DependentLibrary& libInfo = fLibraries[i];
 554                                 if ( libInfo.image != NULL )
 555                                         libInfo.image->recursiveRebase(context);
 556                         }
 557
 558                         // rebase this image
 559                         doRebase(context);
 560                 }
 561                 catch (const char* msg) {
 562                         // this image is not rebased
 563                         fBased = false;
 564                         throw msg;
 565                 }
 566         }
 567 }
 568
 569
 570
 571
 572 void ImageLoader::recursiveBind(const LinkContext& context, BindingLaziness bindness)
 573 {
 574         // normally just non-lazy pointers are bound up front,
 575         // but DYLD_BIND_AT_LAUNCH will cause lazy pointers to be bound up from
 576         // and some dyld API's bind all lazys at runtime
 577         bool nonLazy = false;
 578         bool lazy = false;
 579         switch( bindness ) {
 580                 case kNonLazyOnly:
 581                         nonLazy = true;
 582                         break;
 583                 case kLazyAndNonLazy:
 584                         nonLazy = true;
 585                         lazy = true;
 586                         break;
 587                 case kLazyOnly:
 588                 case kLazyOnlyNoDependents:
 589                         lazy = true;
 590                         break;
 591         }
 592         const bool doNonLazy = nonLazy && !fBoundAllNonLazy;
 593         const bool doLazy = lazy && !fBoundAllLazy;
 594         if ( doNonLazy || doLazy ) {
 595                 // break cycles
 596                 bool oldBoundAllNonLazy = fBoundAllNonLazy;
 597                 bool oldBoundAllLazy = fBoundAllLazy;
 598                 fBoundAllNonLazy = fBoundAllNonLazy || nonLazy;
 599                 fBoundAllLazy = fBoundAllLazy || lazy;
 600
 601                 try {
 602                         // bind lower level libraries first
 603                         if ( bindness != kLazyOnlyNoDependents ) {
 604                                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 605                                         DependentLibrary& libInfo = fLibraries[i];
 606                                         if ( libInfo.image != NULL )
 607                                                 libInfo.image->recursiveBind(context, bindness);
 608                                 }
 609                         }
 610                         // bind this image
 611                         if ( doLazy && !doNonLazy )
 612                                 doBind(context, kLazyOnly);
 613                         else if ( !doLazy && doNonLazy )
 614                                 doBind(context, kNonLazyOnly);
 615                         else
 616                                 doBind(context, kLazyAndNonLazy);
 617                 }
 618                 catch (const char* msg) {
 619                         // restore state
 620                         fBoundAllNonLazy = oldBoundAllNonLazy;
 621                         fBoundAllLazy = oldBoundAllLazy;
 622                         throw msg;
 623                 }
 624         }
 625 }
 626
 627 //
 628 // This is complex because _dyld_register_func_for_add_image() is defined to not only
 629 // notify you of future image loads, but also of all currently loaded images.  Therefore
 630 // each image needs to track that all add-image-funcs have been notified about it.
 631 // Since add-image-funcs cannot be removed, each has a unique index and each image
 632 // records the thru which index notificiation has already been done.
 633 //
 634 void ImageLoader::recursiveImageNotification(const LinkContext& context, uint32_t addImageCount)
 635 {
 636         if ( fNextAddImageIndex < addImageCount ) {
 637                 // break cycles
 638                 const uint32_t initIndex = fNextAddImageIndex;
 639                 fNextAddImageIndex = addImageCount;
 640
 641                 // notify all requestors about this image
 642                 context.imageNotification(this, initIndex);
 643
 644                 // notify about lower level libraries first
 645                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 646                         DependentLibrary& libInfo = fLibraries[i];
 647                         if ( libInfo.image != NULL )
 648                                 libInfo.image->recursiveImageNotification(context, addImageCount);
 649                 }
 650         }
 651 }
 652
 653
 654 void ImageLoader::recursiveImageAnnouncement(const LinkContext& context, std::vector<ImageLoader*>& newImages)
 655 {
 656         if ( ! fAnnounced ) {
 657                 // break cycles
 658                 fAnnounced = true;
 659
 660                 // announce lower level libraries first
 661                 for(unsigned int i=0; i < fLibrariesCount; ++i){
 662                         DependentLibrary& libInfo = fLibraries[i];
 663                         if ( libInfo.image != NULL )
 664                                 libInfo.image->recursiveImageAnnouncement(context, newImages);
 665                 }
 666
 667                 // add to list of images to notify gdb about
 668                 newImages.push_back(this);
 669                 //fprintf(stderr, "next size = %d\n", newImages.size());
 670
 671                 // remember that this image wants to be notified about other images
 672                  if ( this->hasImageNotification() )
 673                         context.addImageNeedingNotification(this);
 674         }
 675 }
 676
 677
 678
 679 void ImageLoader::recursiveInitialization(const LinkContext& context)
 680 {
 681         if ( ! fInitialized ) {
 682                 // break cycles
 683                 fInitialized = true;
 684
 685                 try {
 686                         // initialize lower level libraries first
 687                         for(unsigned int i=0; i < fLibrariesCount; ++i){
 688                                 DependentLibrary& libInfo = fLibraries[i];
 689                                 if ( libInfo.image != NULL )
 690                                         libInfo.image->recursiveInitialization(context);
 691                         }
 692
 693                         // record termination order
 694                         if ( this->needsTermination() )
 695                                 context.terminationRecorder(this);
 696
 697                         // initialize this image
 698                         this->doInitialization(context);
 699                 }
 700                 catch (const char* msg) {
 701                         // this image is not initialized
 702                         fInitialized = false;
 703                         throw msg;
 704                 }
 705         }
 706 }
 707
 708 void ImageLoader::reprebindCommit(const LinkContext& context, bool commit, bool unmapOld)
 709 {
 710         // do nothing on unprebound images
 711         if ( ! this->isPrebindable() )
 712                 return;
 713
 714         // do nothing if prebinding is up to date
 715         if ( this->usablePrebinding(context) )
 716                 return;
 717
 718         // make sure we are not replacing a symlink with a file
 719         char realFilePath[PATH_MAX];
 720         if ( realpath(this->getPath(), realFilePath) == NULL ) {
 721                 throwf("realpath() failed on %s, errno=%d", this->getPath(), errno);
 722         }
 723         // recreate temp file name
 724         char tempFilePath[strlen(realFilePath)+strlen("_redoprebinding")+2];
 725         ImageLoader::addSuffix(realFilePath, "_redoprebinding", tempFilePath);
 726
 727         if ( commit ) {
 728                 // all files successfully reprebound, so do swap
 729                 int result = rename(tempFilePath, realFilePath);
 730                 if ( result != 0 ) {
 731                         // if there are two dylibs with the same install path, the second will fail to prebind
 732                         // because the _redoprebinding temp file is gone.  In that case, log and go on.
 733                         if ( errno == ENOENT )
 734                                 fprintf(stderr, "update_prebinding: temp file missing: %s\n", tempFilePath);
 735                         else
 736                                 throwf("can't swap temporary re-prebound file: rename(%s,%s) returned errno=%d", tempFilePath, realFilePath, errno);
 737                 }
 738                 else if ( unmapOld ) {
 739                         this->prebindUnmap(context);
 740                 }
 741         }
 742         else {
 743                 // something went wrong during prebinding, delete the temp files
 744                 unlink(tempFilePath);
 745         }
 746 }
 747
 748 uint64_t ImageLoader::reprebind(const LinkContext& context, time_t timestamp)
 749 {
 750         // do nothing on unprebound images
 751         if ( ! this->isPrebindable() )
 752                 return INT64_MAX;
 753
 754         // do nothing if prebinding is up to date
 755         if ( this->usablePrebinding(context) ) {
 756                 if ( context.verbosePrebinding )
 757                         fprintf(stderr, "dyld: no need to re-prebind: %s\n", this->getPath());
 758                 return INT64_MAX;
 759         }
 760         // recreate temp file name
 761         char realFilePath[PATH_MAX];
 762         if ( realpath(this->getPath(), realFilePath) == NULL ) {
 763                 throwf("realpath() failed on %s, errno=%d", this->getPath(), errno);
 764         }
 765         char tempFilePath[strlen(realFilePath)+strlen("_redoprebinding")+2];
 766         ImageLoader::addSuffix(realFilePath, "_redoprebinding", tempFilePath);
 767
 768         // make copy of file and map it in
 769         uint8_t* fileToPrebind;
 770         uint64_t fileToPrebindSize;
 771         uint64_t freespace = this->copyAndMap(tempFilePath, &fileToPrebind, &fileToPrebindSize);
 772
 773         // do format specific prebinding
 774         this->doPrebinding(context, timestamp, fileToPrebind);
 775
 776         // flush and swap files
 777         int result = msync(fileToPrebind, fileToPrebindSize, MS_ASYNC);
 778         if ( result != 0 )
 779                 throw "error syncing re-prebound file";
 780         result = munmap(fileToPrebind, fileToPrebindSize);
 781         if ( result != 0 )
 782                 throw "error unmapping re-prebound file";
 783
 784         // log
 785         if ( context.verbosePrebinding )
 786                 fprintf(stderr, "dyld: re-prebound: %p %s\n", this->machHeader(), this->getPath());
 787
 788         return freespace;
 789 }
 790
 791 uint64_t ImageLoader::copyAndMap(const char* tempFile, uint8_t** fileToPrebind, uint64_t* fileToPrebindSize)
 792 {
 793         // reopen dylib
 794         int src = open(this->getPath(), O_RDONLY);
 795         if ( src == -1 )
 796                 throw "can't open image";
 797         struct stat stat_buf;
 798         if ( fstat(src, &stat_buf) == -1)
 799                 throw "can't stat image";
 800         if ( stat_buf.st_mtime != fLastModified )
 801                 throw "image file changed since it was loaded";
 802
 803         // create new file with all same permissions to hold copy of dylib
 804         unlink(tempFile);
 805         int dst = open(tempFile, O_CREAT | O_RDWR | O_TRUNC, stat_buf.st_mode);
 806         if ( dst == -1 )
 807                 throw "can't create temp image";
 808
 809         // mark source as "don't cache"
 810         (void)fcntl(src, F_NOCACHE, 1);
 811         // we want to cache the dst because we are about to map it in and modify it
 812
 813         // copy permission bits
 814         if ( chmod(tempFile, stat_buf.st_mode & 07777) == -1 )
 815                 throwf("can't chmod temp image.  errno=%d for %s", errno, this->getPath());
 816         if ( chown(tempFile, stat_buf.st_uid, stat_buf.st_gid) == -1)
 817                 throwf("can't chown temp image.  errno=%d for %s", errno, this->getPath());
 818
 819         // copy contents
 820         ssize_t len;
 821         const uint32_t kBufferSize = 128*1024;
 822         static uint8_t* buffer = NULL;
 823         if ( buffer == NULL ) {
 824                 vm_address_t addr = 0;
 825                 if ( vm_allocate(mach_task_self(), &addr, kBufferSize, true /*find range*/) == KERN_SUCCESS )
 826                         buffer = (uint8_t*)addr;
 827                 else
 828                         throw "can't allcoate copy buffer";
 829         }
 830         while ( (len = read(src, buffer, kBufferSize)) > 0 ) {
 831                 if ( write(dst, buffer, len) == -1 )
 832                         throwf("write failure copying dylib errno=%d for %s", errno, this->getPath());
 833         }
 834
 835         // map in dst file
 836         *fileToPrebindSize = stat_buf.st_size - fOffsetInFatFile; // this may map in too much, but it does not matter
 837         *fileToPrebind = (uint8_t*)mmap(NULL, *fileToPrebindSize, PROT_READ | PROT_WRITE, MAP_FILE | MAP_SHARED, dst, fOffsetInFatFile);
 838         if ( *fileToPrebind == (uint8_t*)(-1) )
 839                 throw "can't mmap temp image";
 840
 841         // get free space remaining on dst volume
 842         struct statfs statfs_buf;
 843         if ( fstatfs(dst, &statfs_buf) != 0 )
 844                 throwf("can't fstatfs(), errno=%d for %s", errno, tempFile);
 845         uint64_t freespace = statfs_buf.f_bavail * statfs_buf.f_bsize;
 846
 847         // closing notes:
 848         //              ok to close file after mapped in
 849         //              ok to throw above without closing file because the throw will terminate update_prebinding
 850         int result1 = close(dst);
 851         int result2 = close(src);
 852         if ( (result1 != 0) || (result2 != 0) )
 853                 throw "can't close file";
 854
 855         return freespace;
 856 }
 857
 858
 859 static void printTime(const char* msg, uint64_t partTime, uint64_t totalTime)
 860 {
 861         static uint64_t sUnitsPerSecond = 0;
 862         if ( sUnitsPerSecond == 0 ) {
 863                 struct mach_timebase_info timeBaseInfo;
 864                 if ( mach_timebase_info(&timeBaseInfo) == KERN_SUCCESS ) {
 865                         sUnitsPerSecond = timeBaseInfo.denom;
 866                 }
 867         }
 868         if ( partTime < sUnitsPerSecond ) {
 869                 uint32_t milliSecondsTimeTen = (partTime*10000)/sUnitsPerSecond;
 870                 uint32_t milliSeconds = milliSecondsTimeTen/10;
 871                 uint32_t percentTimesTen = (partTime*1000)/totalTime;
 872                 uint32_t percent = percentTimesTen/10;
 873                 fprintf(stderr, "%s: %u.%u milliseconds (%u.%u%%)\n", msg, milliSeconds, milliSecondsTimeTen-milliSeconds*10, percent, percentTimesTen-percent*10);
 874         }
 875         else {
 876                 uint32_t secondsTimeTen = (partTime*10)/sUnitsPerSecond;
 877                 uint32_t seconds = secondsTimeTen/100;
 878                 uint32_t percentTimesTen = (partTime*1000)/totalTime;
 879                 uint32_t percent = percentTimesTen/10;
 880                 fprintf(stderr, "%s: %u.%u seconds (%u.%u%%)\n", msg, seconds, secondsTimeTen-seconds*10, percent, percentTimesTen-percent*10);
 881         }
 882 }
 883
 884 static char* commatize(uint64_t in, char* out)
 885 {
 886         char* result = out;
 887         char rawNum[30];
 888         sprintf(rawNum, "%llu", in);
 889         const int rawNumLen = strlen(rawNum);
 890         for(int i=0; i < rawNumLen-1; ++i) {
 891                 *out++ = rawNum[i];
 892                 if ( ((rawNumLen-i) % 3) == 1 )
 893                         *out++ = ',';
 894         }
 895         *out++ = rawNum[rawNumLen-1];
 896         *out = '\0';
 897         return result;
 898 }
 899
 900
 901 void ImageLoader::printStatistics(unsigned int imageCount)
 902 {
 903         uint64_t totalTime = fgTotalLoadLibrariesTime + fgTotalRebaseTime + fgTotalBindTime + fgTotalNotifyTime + fgTotalInitTime;
 904         char commaNum1[40];
 905         char commaNum2[40];
 906
 907         printTime("total time", totalTime, totalTime);
 908         fprintf(stderr, "total images loaded:  %d (%d used prebinding)\n", imageCount, fgImagesWithUsedPrebinding);
 909         printTime("total images loading time", fgTotalLoadLibrariesTime, totalTime);
 910         fprintf(stderr, "total rebase fixups:  %s\n", commatize(fgTotalRebaseFixups, commaNum1));
 911         printTime("total rebase fixups time", fgTotalRebaseFixups, totalTime);
 912         fprintf(stderr, "total binding fixups: %s\n", commatize(fgTotalBindFixups, commaNum1));
 913         printTime("total binding fixups time", fgTotalBindTime, totalTime);
 914         fprintf(stderr, "total bindings lazily fixed up: %s of %s\n", commatize(fgTotalLazyBindFixups, commaNum1), commatize(fgTotalPossibleLazyBindFixups, commaNum2));
 915         printTime("total notify time time", fgTotalNotifyTime, totalTime);
 916         printTime("total init time time", fgTotalInitTime, totalTime);
 917 }
 918
 919
 920 //
 921 // copy path and add suffix to result
 922 //
 923 //  /path/foo.dylib             _debug   =>   /path/foo_debug.dylib
 924 //  foo.dylib                   _debug   =>   foo_debug.dylib
 925 //  foo                         _debug   =>   foo_debug
 926 //  /path/bar                   _debug   =>   /path/bar_debug
 927 //  /path/bar.A.dylib   _debug   =>   /path/bar.A_debug.dylib
 928 //
 929 void ImageLoader::addSuffix(const char* path, const char* suffix, char* result)
 930 {
 931         strcpy(result, path);
 932
 933         char* start = strrchr(result, '/');
 934         if ( start != NULL )
 935                 start++;
 936         else
 937                 start = result;
 938
 939         char* dot = strrchr(start, '.');
 940         if ( dot != NULL ) {
 941                 strcpy(dot, suffix);
 942                 strcat(&dot[strlen(suffix)], &path[dot-result]);
 943         }
 944         else {
 945                 strcat(result, suffix);
 946         }
 947 }
 948
 949
 950 void Segment::map(int fd, uint64_t offsetInFatWrapper, intptr_t slide, const ImageLoader::LinkContext& context)
 951 {
 952         vm_offset_t fileOffset = this->getFileOffset() + offsetInFatWrapper;
 953         vm_size_t size = this->getFileSize();
 954         void* requestedLoadAddress = (void*)(this->getPreferredLoadAddress() + slide);
 955         int protection = 0;
 956         if ( !this->unaccessible() ) {
 957                 if ( this->executable() )
 958                         protection   |= PROT_EXEC;
 959                 if ( this->readable() )
 960                         protection   |= PROT_READ;
 961                 if ( this->writeable() )
 962                         protection   |= PROT_WRITE;
 963         }
 964         void* loadAddress = mmap(requestedLoadAddress, size, protection, MAP_FILE | MAP_FIXED | MAP_PRIVATE, fd, fileOffset);
 965         if ( loadAddress == ((void*)(-1)) )
 966                 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());
 967
 968         if ( context.verboseMapping )
 969                 fprintf(stderr, "%18s at %p->%p\n", this->getName(), loadAddress, (char*)loadAddress+this->getFileSize()-1);
 970 }
 971
 972 void Segment::map(const void* memoryImage, intptr_t slide, const ImageLoader::LinkContext& context)
 973 {
 974         vm_address_t loadAddress = this->getPreferredLoadAddress() + slide;
 975         vm_address_t srcAddr = (uintptr_t)memoryImage + this->getFileOffset();
 976         vm_size_t size = this->getFileSize();
 977         kern_return_t r = vm_copy(mach_task_self(), srcAddr, size, loadAddress);
 978         if ( r != KERN_SUCCESS )
 979                 throw "can't map segment";
 980
 981         if ( context.verboseMapping )
 982                 fprintf(stderr, "%18s at %p->%p\n", this->getName(), (char*)loadAddress, (char*)loadAddress+this->getFileSize()-1);
 983 }
 984
 985 void Segment::setPermissions()
 986 {
 987         vm_prot_t protection = 0;
 988         if ( !this->unaccessible() ) {
 989                 if ( this->executable() )
 990                         protection   |= VM_PROT_EXECUTE;
 991                 if ( this->readable() )
 992                         protection   |= VM_PROT_READ;
 993                 if ( this->writeable() )
 994                         protection   |= VM_PROT_WRITE;
 995         }
 996         vm_address_t addr = this->getActualLoadAddress();
 997         vm_size_t size = this->getSize();
 998         const bool setCurrentPermissions = false;
 999         kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, protection);
1000         if ( r != KERN_SUCCESS )
1001                 throw "can't set vm permissions for mapped segment";
1002 }
1003
1004 void Segment::tempWritable()
1005 {
1006         vm_address_t addr = this->getActualLoadAddress();
1007         vm_size_t size = this->getSize();
1008         const bool setCurrentPermissions = false;
1009         kern_return_t r = vm_protect(mach_task_self(), addr, size, setCurrentPermissions, VM_PROT_WRITE | VM_PROT_READ);
1010         if ( r != KERN_SUCCESS )
1011                 throw "can't set vm permissions for mapped segment";
1012 }
1013
1014
1015 bool Segment::hasTrailingZeroFill()
1016 {
1017         return ( this->writeable() && (this->getSize() > this->getFileSize()) );
1018 }
1019
1020
1021 uintptr_t Segment::reserveAnAddressRange(size_t length, const ImageLoader::LinkContext& context)
1022 {
1023         vm_address_t addr = 0;
1024         vm_size_t size = length;
1025         if ( context.slideAndPackDylibs ) {
1026                 addr = (fgNextNonSplitSegAddress - length) & (-4096); // page align
1027                 kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*use this range*/);
1028                 if ( r != KERN_SUCCESS )
1029                         throw "out of address space";
1030                 fgNextNonSplitSegAddress = addr;
1031         }
1032         else {
1033                 kern_return_t r = vm_allocate(mach_task_self(), &addr, size, true /*find range*/);
1034                 if ( r != KERN_SUCCESS )
1035                         throw "out of address space";
1036         }
1037         return addr;
1038 }
1039
1040 bool Segment::reserveAddressRange(uintptr_t start, size_t length)
1041 {
1042         vm_address_t addr = start;
1043         vm_size_t size = length;
1044         kern_return_t r = vm_allocate(mach_task_self(), &addr, size, false /*only this range*/);
1045         if ( r != KERN_SUCCESS )
1046                 return false;
1047         return true;
1048 }
1049
1050
1051