1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include "image_writer.h" 18 19 #include <sys/stat.h> 20 21 #include <memory> 22 #include <vector> 23 24 #include "base/logging.h" 25 #include "base/unix_file/fd_file.h" 26 #include "class_linker.h" 27 #include "compiled_method.h" 28 #include "dex_file-inl.h" 29 #include "driver/compiler_driver.h" 30 #include "elf_file.h" 31 #include "elf_utils.h" 32 #include "elf_patcher.h" 33 #include "elf_writer.h" 34 #include "gc/accounting/card_table-inl.h" 35 #include "gc/accounting/heap_bitmap.h" 36 #include "gc/accounting/space_bitmap-inl.h" 37 #include "gc/heap.h" 38 #include "gc/space/large_object_space.h" 39 #include "gc/space/space-inl.h" 40 #include "globals.h" 41 #include "image.h" 42 #include "intern_table.h" 43 #include "lock_word.h" 44 #include "mirror/art_field-inl.h" 45 #include "mirror/art_method-inl.h" 46 #include "mirror/array-inl.h" 47 #include "mirror/class-inl.h" 48 #include "mirror/class_loader.h" 49 #include "mirror/dex_cache-inl.h" 50 #include "mirror/object-inl.h" 51 #include "mirror/object_array-inl.h" 52 #include "mirror/string-inl.h" 53 #include "oat.h" 54 #include "oat_file.h" 55 #include "runtime.h" 56 #include "scoped_thread_state_change.h" 57 #include "handle_scope-inl.h" 58 #include "utils.h" 59 60 using ::art::mirror::ArtField; 61 using ::art::mirror::ArtMethod; 62 using ::art::mirror::Class; 63 using ::art::mirror::DexCache; 64 using ::art::mirror::EntryPointFromInterpreter; 65 using ::art::mirror::Object; 66 using ::art::mirror::ObjectArray; 67 using ::art::mirror::String; 68 69 namespace art { 70 71 bool ImageWriter::Write(const std::string& image_filename, 72 uintptr_t image_begin, 73 const std::string& oat_filename, 74 const std::string& oat_location) { 75 CHECK(!image_filename.empty()); 76 77 CHECK_NE(image_begin, 0U); 78 image_begin_ = reinterpret_cast<byte*>(image_begin); 79 80 ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); 81 82 std::unique_ptr<File> oat_file(OS::OpenFileReadWrite(oat_filename.c_str())); 83 if (oat_file.get() == NULL) { 84 LOG(ERROR) << "Failed to open oat file " << oat_filename << " for " << oat_location; 85 return false; 86 } 87 std::string error_msg; 88 oat_file_ = OatFile::OpenReadable(oat_file.get(), oat_location, &error_msg); 89 if (oat_file_ == nullptr) { 90 LOG(ERROR) << "Failed to open writable oat file " << oat_filename << " for " << oat_location 91 << ": " << error_msg; 92 return false; 93 } 94 CHECK_EQ(class_linker->RegisterOatFile(oat_file_), oat_file_); 95 96 interpreter_to_interpreter_bridge_offset_ = 97 oat_file_->GetOatHeader().GetInterpreterToInterpreterBridgeOffset(); 98 interpreter_to_compiled_code_bridge_offset_ = 99 oat_file_->GetOatHeader().GetInterpreterToCompiledCodeBridgeOffset(); 100 101 jni_dlsym_lookup_offset_ = oat_file_->GetOatHeader().GetJniDlsymLookupOffset(); 102 103 portable_imt_conflict_trampoline_offset_ = 104 oat_file_->GetOatHeader().GetPortableImtConflictTrampolineOffset(); 105 portable_resolution_trampoline_offset_ = 106 oat_file_->GetOatHeader().GetPortableResolutionTrampolineOffset(); 107 portable_to_interpreter_bridge_offset_ = 108 oat_file_->GetOatHeader().GetPortableToInterpreterBridgeOffset(); 109 110 quick_generic_jni_trampoline_offset_ = 111 oat_file_->GetOatHeader().GetQuickGenericJniTrampolineOffset(); 112 quick_imt_conflict_trampoline_offset_ = 113 oat_file_->GetOatHeader().GetQuickImtConflictTrampolineOffset(); 114 quick_resolution_trampoline_offset_ = 115 oat_file_->GetOatHeader().GetQuickResolutionTrampolineOffset(); 116 quick_to_interpreter_bridge_offset_ = 117 oat_file_->GetOatHeader().GetQuickToInterpreterBridgeOffset(); 118 { 119 Thread::Current()->TransitionFromSuspendedToRunnable(); 120 PruneNonImageClasses(); // Remove junk 121 ComputeLazyFieldsForImageClasses(); // Add useful information 122 ComputeEagerResolvedStrings(); 123 Thread::Current()->TransitionFromRunnableToSuspended(kNative); 124 } 125 gc::Heap* heap = Runtime::Current()->GetHeap(); 126 heap->CollectGarbage(false); // Remove garbage. 127 128 if (!AllocMemory()) { 129 return false; 130 } 131 132 if (kIsDebugBuild) { 133 ScopedObjectAccess soa(Thread::Current()); 134 CheckNonImageClassesRemoved(); 135 } 136 137 Thread::Current()->TransitionFromSuspendedToRunnable(); 138 size_t oat_loaded_size = 0; 139 size_t oat_data_offset = 0; 140 ElfWriter::GetOatElfInformation(oat_file.get(), oat_loaded_size, oat_data_offset); 141 CalculateNewObjectOffsets(oat_loaded_size, oat_data_offset); 142 CopyAndFixupObjects(); 143 144 PatchOatCodeAndMethods(oat_file.get()); 145 Thread::Current()->TransitionFromRunnableToSuspended(kNative); 146 147 std::unique_ptr<File> image_file(OS::CreateEmptyFile(image_filename.c_str())); 148 ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin()); 149 if (image_file.get() == NULL) { 150 LOG(ERROR) << "Failed to open image file " << image_filename; 151 return false; 152 } 153 if (fchmod(image_file->Fd(), 0644) != 0) { 154 PLOG(ERROR) << "Failed to make image file world readable: " << image_filename; 155 return EXIT_FAILURE; 156 } 157 158 // Write out the image. 159 CHECK_EQ(image_end_, image_header->GetImageSize()); 160 if (!image_file->WriteFully(image_->Begin(), image_end_)) { 161 PLOG(ERROR) << "Failed to write image file " << image_filename; 162 return false; 163 } 164 165 // Write out the image bitmap at the page aligned start of the image end. 166 CHECK_ALIGNED(image_header->GetImageBitmapOffset(), kPageSize); 167 if (!image_file->Write(reinterpret_cast<char*>(image_bitmap_->Begin()), 168 image_header->GetImageBitmapSize(), 169 image_header->GetImageBitmapOffset())) { 170 PLOG(ERROR) << "Failed to write image file " << image_filename; 171 return false; 172 } 173 174 return true; 175 } 176 177 void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) { 178 DCHECK(object != nullptr); 179 DCHECK_NE(offset, 0U); 180 DCHECK(!IsImageOffsetAssigned(object)); 181 mirror::Object* obj = reinterpret_cast<mirror::Object*>(image_->Begin() + offset); 182 DCHECK_ALIGNED(obj, kObjectAlignment); 183 image_bitmap_->Set(obj); 184 // Before we stomp over the lock word, save the hash code for later. 185 Monitor::Deflate(Thread::Current(), object);; 186 LockWord lw(object->GetLockWord(false)); 187 switch (lw.GetState()) { 188 case LockWord::kFatLocked: { 189 LOG(FATAL) << "Fat locked object " << obj << " found during object copy"; 190 break; 191 } 192 case LockWord::kThinLocked: { 193 LOG(FATAL) << "Thin locked object " << obj << " found during object copy"; 194 break; 195 } 196 case LockWord::kUnlocked: 197 // No hash, don't need to save it. 198 break; 199 case LockWord::kHashCode: 200 saved_hashes_.push_back(std::make_pair(obj, lw.GetHashCode())); 201 break; 202 default: 203 LOG(FATAL) << "Unreachable."; 204 break; 205 } 206 object->SetLockWord(LockWord::FromForwardingAddress(offset), false); 207 DCHECK(IsImageOffsetAssigned(object)); 208 } 209 210 void ImageWriter::AssignImageOffset(mirror::Object* object) { 211 DCHECK(object != nullptr); 212 SetImageOffset(object, image_end_); 213 image_end_ += RoundUp(object->SizeOf(), 8); // 64-bit alignment 214 DCHECK_LT(image_end_, image_->Size()); 215 } 216 217 bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const { 218 DCHECK(object != nullptr); 219 return object->GetLockWord(false).GetState() == LockWord::kForwardingAddress; 220 } 221 222 size_t ImageWriter::GetImageOffset(mirror::Object* object) const { 223 DCHECK(object != nullptr); 224 DCHECK(IsImageOffsetAssigned(object)); 225 LockWord lock_word = object->GetLockWord(false); 226 size_t offset = lock_word.ForwardingAddress(); 227 DCHECK_LT(offset, image_end_); 228 return offset; 229 } 230 231 bool ImageWriter::AllocMemory() { 232 size_t length = RoundUp(Runtime::Current()->GetHeap()->GetTotalMemory(), kPageSize); 233 std::string error_msg; 234 image_.reset(MemMap::MapAnonymous("image writer image", NULL, length, PROT_READ | PROT_WRITE, 235 true, &error_msg)); 236 if (UNLIKELY(image_.get() == nullptr)) { 237 LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg; 238 return false; 239 } 240 241 // Create the image bitmap. 242 image_bitmap_.reset(gc::accounting::ContinuousSpaceBitmap::Create("image bitmap", image_->Begin(), 243 length)); 244 if (image_bitmap_.get() == nullptr) { 245 LOG(ERROR) << "Failed to allocate memory for image bitmap"; 246 return false; 247 } 248 return true; 249 } 250 251 void ImageWriter::ComputeLazyFieldsForImageClasses() { 252 ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); 253 class_linker->VisitClassesWithoutClassesLock(ComputeLazyFieldsForClassesVisitor, NULL); 254 } 255 256 bool ImageWriter::ComputeLazyFieldsForClassesVisitor(Class* c, void* /*arg*/) { 257 Thread* self = Thread::Current(); 258 StackHandleScope<1> hs(self); 259 mirror::Class::ComputeName(hs.NewHandle(c)); 260 return true; 261 } 262 263 void ImageWriter::ComputeEagerResolvedStringsCallback(Object* obj, void* arg) { 264 if (!obj->GetClass()->IsStringClass()) { 265 return; 266 } 267 mirror::String* string = obj->AsString(); 268 const uint16_t* utf16_string = string->GetCharArray()->GetData() + string->GetOffset(); 269 ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); 270 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock()); 271 size_t dex_cache_count = class_linker->GetDexCacheCount(); 272 for (size_t i = 0; i < dex_cache_count; ++i) { 273 DexCache* dex_cache = class_linker->GetDexCache(i); 274 const DexFile& dex_file = *dex_cache->GetDexFile(); 275 const DexFile::StringId* string_id; 276 if (UNLIKELY(string->GetLength() == 0)) { 277 string_id = dex_file.FindStringId(""); 278 } else { 279 string_id = dex_file.FindStringId(utf16_string); 280 } 281 if (string_id != nullptr) { 282 // This string occurs in this dex file, assign the dex cache entry. 283 uint32_t string_idx = dex_file.GetIndexForStringId(*string_id); 284 if (dex_cache->GetResolvedString(string_idx) == NULL) { 285 dex_cache->SetResolvedString(string_idx, string); 286 } 287 } 288 } 289 } 290 291 void ImageWriter::ComputeEagerResolvedStrings() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 292 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 293 Runtime::Current()->GetHeap()->VisitObjects(ComputeEagerResolvedStringsCallback, this); 294 } 295 296 bool ImageWriter::IsImageClass(Class* klass) { 297 std::string temp; 298 return compiler_driver_.IsImageClass(klass->GetDescriptor(&temp)); 299 } 300 301 struct NonImageClasses { 302 ImageWriter* image_writer; 303 std::set<std::string>* non_image_classes; 304 }; 305 306 void ImageWriter::PruneNonImageClasses() { 307 if (compiler_driver_.GetImageClasses() == NULL) { 308 return; 309 } 310 Runtime* runtime = Runtime::Current(); 311 ClassLinker* class_linker = runtime->GetClassLinker(); 312 313 // Make a list of classes we would like to prune. 314 std::set<std::string> non_image_classes; 315 NonImageClasses context; 316 context.image_writer = this; 317 context.non_image_classes = &non_image_classes; 318 class_linker->VisitClasses(NonImageClassesVisitor, &context); 319 320 // Remove the undesired classes from the class roots. 321 for (const std::string& it : non_image_classes) { 322 class_linker->RemoveClass(it.c_str(), NULL); 323 } 324 325 // Clear references to removed classes from the DexCaches. 326 ArtMethod* resolution_method = runtime->GetResolutionMethod(); 327 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock()); 328 size_t dex_cache_count = class_linker->GetDexCacheCount(); 329 for (size_t idx = 0; idx < dex_cache_count; ++idx) { 330 DexCache* dex_cache = class_linker->GetDexCache(idx); 331 for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) { 332 Class* klass = dex_cache->GetResolvedType(i); 333 if (klass != NULL && !IsImageClass(klass)) { 334 dex_cache->SetResolvedType(i, NULL); 335 } 336 } 337 for (size_t i = 0; i < dex_cache->NumResolvedMethods(); i++) { 338 ArtMethod* method = dex_cache->GetResolvedMethod(i); 339 if (method != NULL && !IsImageClass(method->GetDeclaringClass())) { 340 dex_cache->SetResolvedMethod(i, resolution_method); 341 } 342 } 343 for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) { 344 ArtField* field = dex_cache->GetResolvedField(i); 345 if (field != NULL && !IsImageClass(field->GetDeclaringClass())) { 346 dex_cache->SetResolvedField(i, NULL); 347 } 348 } 349 } 350 } 351 352 bool ImageWriter::NonImageClassesVisitor(Class* klass, void* arg) { 353 NonImageClasses* context = reinterpret_cast<NonImageClasses*>(arg); 354 if (!context->image_writer->IsImageClass(klass)) { 355 std::string temp; 356 context->non_image_classes->insert(klass->GetDescriptor(&temp)); 357 } 358 return true; 359 } 360 361 void ImageWriter::CheckNonImageClassesRemoved() 362 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 363 if (compiler_driver_.GetImageClasses() != nullptr) { 364 gc::Heap* heap = Runtime::Current()->GetHeap(); 365 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 366 heap->VisitObjects(CheckNonImageClassesRemovedCallback, this); 367 } 368 } 369 370 void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) { 371 ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg); 372 if (obj->IsClass()) { 373 Class* klass = obj->AsClass(); 374 if (!image_writer->IsImageClass(klass)) { 375 image_writer->DumpImageClasses(); 376 std::string temp; 377 CHECK(image_writer->IsImageClass(klass)) << klass->GetDescriptor(&temp) 378 << " " << PrettyDescriptor(klass); 379 } 380 } 381 } 382 383 void ImageWriter::DumpImageClasses() { 384 const std::set<std::string>* image_classes = compiler_driver_.GetImageClasses(); 385 CHECK(image_classes != NULL); 386 for (const std::string& image_class : *image_classes) { 387 LOG(INFO) << " " << image_class; 388 } 389 } 390 391 void ImageWriter::CalculateObjectOffsets(Object* obj) { 392 DCHECK(obj != NULL); 393 // if it is a string, we want to intern it if its not interned. 394 if (obj->GetClass()->IsStringClass()) { 395 // we must be an interned string that was forward referenced and already assigned 396 if (IsImageOffsetAssigned(obj)) { 397 DCHECK_EQ(obj, obj->AsString()->Intern()); 398 return; 399 } 400 mirror::String* const interned = obj->AsString()->Intern(); 401 if (obj != interned) { 402 if (!IsImageOffsetAssigned(interned)) { 403 // interned obj is after us, allocate its location early 404 AssignImageOffset(interned); 405 } 406 // point those looking for this object to the interned version. 407 SetImageOffset(obj, GetImageOffset(interned)); 408 return; 409 } 410 // else (obj == interned), nothing to do but fall through to the normal case 411 } 412 413 AssignImageOffset(obj); 414 } 415 416 ObjectArray<Object>* ImageWriter::CreateImageRoots() const { 417 Runtime* runtime = Runtime::Current(); 418 ClassLinker* class_linker = runtime->GetClassLinker(); 419 Thread* self = Thread::Current(); 420 StackHandleScope<3> hs(self); 421 Handle<Class> object_array_class(hs.NewHandle( 422 class_linker->FindSystemClass(self, "[Ljava/lang/Object;"))); 423 424 // build an Object[] of all the DexCaches used in the source_space_. 425 // Since we can't hold the dex lock when allocating the dex_caches 426 // ObjectArray, we lock the dex lock twice, first to get the number 427 // of dex caches first and then lock it again to copy the dex 428 // caches. We check that the number of dex caches does not change. 429 size_t dex_cache_count; 430 { 431 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock()); 432 dex_cache_count = class_linker->GetDexCacheCount(); 433 } 434 Handle<ObjectArray<Object>> dex_caches( 435 hs.NewHandle(ObjectArray<Object>::Alloc(self, object_array_class.Get(), 436 dex_cache_count))); 437 CHECK(dex_caches.Get() != nullptr) << "Failed to allocate a dex cache array."; 438 { 439 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock()); 440 CHECK_EQ(dex_cache_count, class_linker->GetDexCacheCount()) 441 << "The number of dex caches changed."; 442 for (size_t i = 0; i < dex_cache_count; ++i) { 443 dex_caches->Set<false>(i, class_linker->GetDexCache(i)); 444 } 445 } 446 447 // build an Object[] of the roots needed to restore the runtime 448 Handle<ObjectArray<Object>> image_roots(hs.NewHandle( 449 ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax))); 450 image_roots->Set<false>(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod()); 451 image_roots->Set<false>(ImageHeader::kImtConflictMethod, runtime->GetImtConflictMethod()); 452 image_roots->Set<false>(ImageHeader::kDefaultImt, runtime->GetDefaultImt()); 453 image_roots->Set<false>(ImageHeader::kCalleeSaveMethod, 454 runtime->GetCalleeSaveMethod(Runtime::kSaveAll)); 455 image_roots->Set<false>(ImageHeader::kRefsOnlySaveMethod, 456 runtime->GetCalleeSaveMethod(Runtime::kRefsOnly)); 457 image_roots->Set<false>(ImageHeader::kRefsAndArgsSaveMethod, 458 runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs)); 459 image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get()); 460 image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots()); 461 for (int i = 0; i < ImageHeader::kImageRootsMax; i++) { 462 CHECK(image_roots->Get(i) != NULL); 463 } 464 return image_roots.Get(); 465 } 466 467 // Walk instance fields of the given Class. Separate function to allow recursion on the super 468 // class. 469 void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) { 470 // Visit fields of parent classes first. 471 StackHandleScope<1> hs(Thread::Current()); 472 Handle<mirror::Class> h_class(hs.NewHandle(klass)); 473 mirror::Class* super = h_class->GetSuperClass(); 474 if (super != nullptr) { 475 WalkInstanceFields(obj, super); 476 } 477 // 478 size_t num_reference_fields = h_class->NumReferenceInstanceFields(); 479 for (size_t i = 0; i < num_reference_fields; ++i) { 480 mirror::ArtField* field = h_class->GetInstanceField(i); 481 MemberOffset field_offset = field->GetOffset(); 482 mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset); 483 if (value != nullptr) { 484 WalkFieldsInOrder(value); 485 } 486 } 487 } 488 489 // For an unvisited object, visit it then all its children found via fields. 490 void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) { 491 if (!IsImageOffsetAssigned(obj)) { 492 // Walk instance fields of all objects 493 StackHandleScope<2> hs(Thread::Current()); 494 Handle<mirror::Object> h_obj(hs.NewHandle(obj)); 495 Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass())); 496 // visit the object itself. 497 CalculateObjectOffsets(h_obj.Get()); 498 WalkInstanceFields(h_obj.Get(), klass.Get()); 499 // Walk static fields of a Class. 500 if (h_obj->IsClass()) { 501 size_t num_static_fields = klass->NumReferenceStaticFields(); 502 for (size_t i = 0; i < num_static_fields; ++i) { 503 mirror::ArtField* field = klass->GetStaticField(i); 504 MemberOffset field_offset = field->GetOffset(); 505 mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset); 506 if (value != nullptr) { 507 WalkFieldsInOrder(value); 508 } 509 } 510 } else if (h_obj->IsObjectArray()) { 511 // Walk elements of an object array. 512 int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength(); 513 for (int32_t i = 0; i < length; i++) { 514 mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>(); 515 mirror::Object* value = obj_array->Get(i); 516 if (value != nullptr) { 517 WalkFieldsInOrder(value); 518 } 519 } 520 } 521 } 522 } 523 524 void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) { 525 ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg); 526 DCHECK(writer != nullptr); 527 writer->WalkFieldsInOrder(obj); 528 } 529 530 void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) { 531 CHECK_NE(0U, oat_loaded_size); 532 Thread* self = Thread::Current(); 533 StackHandleScope<1> hs(self); 534 Handle<ObjectArray<Object>> image_roots(hs.NewHandle(CreateImageRoots())); 535 536 gc::Heap* heap = Runtime::Current()->GetHeap(); 537 DCHECK_EQ(0U, image_end_); 538 539 // Leave space for the header, but do not write it yet, we need to 540 // know where image_roots is going to end up 541 image_end_ += RoundUp(sizeof(ImageHeader), 8); // 64-bit-alignment 542 543 { 544 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 545 // TODO: Image spaces only? 546 const char* old = self->StartAssertNoThreadSuspension("ImageWriter"); 547 DCHECK_LT(image_end_, image_->Size()); 548 // Clear any pre-existing monitors which may have been in the monitor words. 549 heap->VisitObjects(WalkFieldsCallback, this); 550 self->EndAssertNoThreadSuspension(old); 551 } 552 553 const byte* oat_file_begin = image_begin_ + RoundUp(image_end_, kPageSize); 554 const byte* oat_file_end = oat_file_begin + oat_loaded_size; 555 oat_data_begin_ = oat_file_begin + oat_data_offset; 556 const byte* oat_data_end = oat_data_begin_ + oat_file_->Size(); 557 558 // Return to write header at start of image with future location of image_roots. At this point, 559 // image_end_ is the size of the image (excluding bitmaps). 560 const size_t heap_bytes_per_bitmap_byte = kBitsPerByte * kObjectAlignment; 561 const size_t bitmap_bytes = RoundUp(image_end_, heap_bytes_per_bitmap_byte) / 562 heap_bytes_per_bitmap_byte; 563 ImageHeader image_header(PointerToLowMemUInt32(image_begin_), 564 static_cast<uint32_t>(image_end_), 565 RoundUp(image_end_, kPageSize), 566 RoundUp(bitmap_bytes, kPageSize), 567 PointerToLowMemUInt32(GetImageAddress(image_roots.Get())), 568 oat_file_->GetOatHeader().GetChecksum(), 569 PointerToLowMemUInt32(oat_file_begin), 570 PointerToLowMemUInt32(oat_data_begin_), 571 PointerToLowMemUInt32(oat_data_end), 572 PointerToLowMemUInt32(oat_file_end)); 573 memcpy(image_->Begin(), &image_header, sizeof(image_header)); 574 575 // Note that image_end_ is left at end of used space 576 } 577 578 void ImageWriter::CopyAndFixupObjects() 579 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 580 Thread* self = Thread::Current(); 581 const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter"); 582 gc::Heap* heap = Runtime::Current()->GetHeap(); 583 // TODO: heap validation can't handle this fix up pass 584 heap->DisableObjectValidation(); 585 // TODO: Image spaces only? 586 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 587 heap->VisitObjects(CopyAndFixupObjectsCallback, this); 588 // Fix up the object previously had hash codes. 589 for (const std::pair<mirror::Object*, uint32_t>& hash_pair : saved_hashes_) { 590 hash_pair.first->SetLockWord(LockWord::FromHashCode(hash_pair.second), false); 591 } 592 saved_hashes_.clear(); 593 self->EndAssertNoThreadSuspension(old_cause); 594 } 595 596 void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) { 597 DCHECK(obj != nullptr); 598 DCHECK(arg != nullptr); 599 ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg); 600 // see GetLocalAddress for similar computation 601 size_t offset = image_writer->GetImageOffset(obj); 602 byte* dst = image_writer->image_->Begin() + offset; 603 const byte* src = reinterpret_cast<const byte*>(obj); 604 size_t n = obj->SizeOf(); 605 DCHECK_LT(offset + n, image_writer->image_->Size()); 606 memcpy(dst, src, n); 607 Object* copy = reinterpret_cast<Object*>(dst); 608 // Write in a hash code of objects which have inflated monitors or a hash code in their monitor 609 // word. 610 copy->SetLockWord(LockWord(), false); 611 image_writer->FixupObject(obj, copy); 612 } 613 614 class FixupVisitor { 615 public: 616 FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) { 617 } 618 619 void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const 620 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 621 Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset); 622 // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the 623 // image. 624 copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>( 625 offset, image_writer_->GetImageAddress(ref)); 626 } 627 628 // java.lang.ref.Reference visitor. 629 void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const 630 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 631 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { 632 copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>( 633 mirror::Reference::ReferentOffset(), image_writer_->GetImageAddress(ref->GetReferent())); 634 } 635 636 protected: 637 ImageWriter* const image_writer_; 638 mirror::Object* const copy_; 639 }; 640 641 class FixupClassVisitor FINAL : public FixupVisitor { 642 public: 643 FixupClassVisitor(ImageWriter* image_writer, Object* copy) : FixupVisitor(image_writer, copy) { 644 } 645 646 void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const 647 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 648 DCHECK(obj->IsClass()); 649 FixupVisitor::operator()(obj, offset, false); 650 651 if (offset.Uint32Value() < mirror::Class::EmbeddedVTableOffset().Uint32Value()) { 652 return; 653 } 654 } 655 656 void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const 657 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 658 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { 659 LOG(FATAL) << "Reference not expected here."; 660 } 661 }; 662 663 void ImageWriter::FixupObject(Object* orig, Object* copy) { 664 DCHECK(orig != nullptr); 665 DCHECK(copy != nullptr); 666 if (kUseBakerOrBrooksReadBarrier) { 667 orig->AssertReadBarrierPointer(); 668 if (kUseBrooksReadBarrier) { 669 // Note the address 'copy' isn't the same as the image address of 'orig'. 670 copy->SetReadBarrierPointer(GetImageAddress(orig)); 671 DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig)); 672 } 673 } 674 if (orig->IsClass() && orig->AsClass()->ShouldHaveEmbeddedImtAndVTable()) { 675 FixupClassVisitor visitor(this, copy); 676 orig->VisitReferences<true /*visit class*/>(visitor, visitor); 677 } else { 678 FixupVisitor visitor(this, copy); 679 orig->VisitReferences<true /*visit class*/>(visitor, visitor); 680 } 681 if (orig->IsArtMethod<kVerifyNone>()) { 682 FixupMethod(orig->AsArtMethod<kVerifyNone>(), down_cast<ArtMethod*>(copy)); 683 } 684 } 685 686 const byte* ImageWriter::GetQuickCode(mirror::ArtMethod* method, bool* quick_is_interpreted) { 687 DCHECK(!method->IsResolutionMethod() && !method->IsImtConflictMethod() && 688 !method->IsAbstract()) << PrettyMethod(method); 689 690 // Use original code if it exists. Otherwise, set the code pointer to the resolution 691 // trampoline. 692 693 // Quick entrypoint: 694 const byte* quick_code = GetOatAddress(method->GetQuickOatCodeOffset()); 695 *quick_is_interpreted = false; 696 if (quick_code != nullptr && 697 (!method->IsStatic() || method->IsConstructor() || method->GetDeclaringClass()->IsInitialized())) { 698 // We have code for a non-static or initialized method, just use the code. 699 } else if (quick_code == nullptr && method->IsNative() && 700 (!method->IsStatic() || method->GetDeclaringClass()->IsInitialized())) { 701 // Non-static or initialized native method missing compiled code, use generic JNI version. 702 quick_code = GetOatAddress(quick_generic_jni_trampoline_offset_); 703 } else if (quick_code == nullptr && !method->IsNative()) { 704 // We don't have code at all for a non-native method, use the interpreter. 705 quick_code = GetOatAddress(quick_to_interpreter_bridge_offset_); 706 *quick_is_interpreted = true; 707 } else { 708 CHECK(!method->GetDeclaringClass()->IsInitialized()); 709 // We have code for a static method, but need to go through the resolution stub for class 710 // initialization. 711 quick_code = GetOatAddress(quick_resolution_trampoline_offset_); 712 } 713 return quick_code; 714 } 715 716 const byte* ImageWriter::GetQuickEntryPoint(mirror::ArtMethod* method) { 717 // Calculate the quick entry point following the same logic as FixupMethod() below. 718 // The resolution method has a special trampoline to call. 719 if (UNLIKELY(method == Runtime::Current()->GetResolutionMethod())) { 720 return GetOatAddress(quick_resolution_trampoline_offset_); 721 } else if (UNLIKELY(method == Runtime::Current()->GetImtConflictMethod())) { 722 return GetOatAddress(quick_imt_conflict_trampoline_offset_); 723 } else { 724 // We assume all methods have code. If they don't currently then we set them to the use the 725 // resolution trampoline. Abstract methods never have code and so we need to make sure their 726 // use results in an AbstractMethodError. We use the interpreter to achieve this. 727 if (UNLIKELY(method->IsAbstract())) { 728 return GetOatAddress(quick_to_interpreter_bridge_offset_); 729 } else { 730 bool quick_is_interpreted; 731 return GetQuickCode(method, &quick_is_interpreted); 732 } 733 } 734 } 735 736 void ImageWriter::FixupMethod(ArtMethod* orig, ArtMethod* copy) { 737 // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to 738 // oat_begin_ 739 740 // The resolution method has a special trampoline to call. 741 if (UNLIKELY(orig == Runtime::Current()->GetResolutionMethod())) { 742 #if defined(ART_USE_PORTABLE_COMPILER) 743 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_)); 744 #endif 745 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_)); 746 } else if (UNLIKELY(orig == Runtime::Current()->GetImtConflictMethod())) { 747 #if defined(ART_USE_PORTABLE_COMPILER) 748 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_imt_conflict_trampoline_offset_)); 749 #endif 750 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_imt_conflict_trampoline_offset_)); 751 } else { 752 // We assume all methods have code. If they don't currently then we set them to the use the 753 // resolution trampoline. Abstract methods never have code and so we need to make sure their 754 // use results in an AbstractMethodError. We use the interpreter to achieve this. 755 if (UNLIKELY(orig->IsAbstract())) { 756 #if defined(ART_USE_PORTABLE_COMPILER) 757 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_to_interpreter_bridge_offset_)); 758 #endif 759 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_)); 760 copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*> 761 (const_cast<byte*>(GetOatAddress(interpreter_to_interpreter_bridge_offset_)))); 762 } else { 763 bool quick_is_interpreted; 764 const byte* quick_code = GetQuickCode(orig, &quick_is_interpreted); 765 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(quick_code); 766 767 // Portable entrypoint: 768 bool portable_is_interpreted = false; 769 #if defined(ART_USE_PORTABLE_COMPILER) 770 const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset()); 771 if (portable_code != nullptr && 772 (!orig->IsStatic() || orig->IsConstructor() || orig->GetDeclaringClass()->IsInitialized())) { 773 // We have code for a non-static or initialized method, just use the code. 774 } else if (portable_code == nullptr && orig->IsNative() && 775 (!orig->IsStatic() || orig->GetDeclaringClass()->IsInitialized())) { 776 // Non-static or initialized native method missing compiled code, use generic JNI version. 777 // TODO: generic JNI support for LLVM. 778 portable_code = GetOatAddress(portable_resolution_trampoline_offset_); 779 } else if (portable_code == nullptr && !orig->IsNative()) { 780 // We don't have code at all for a non-native method, use the interpreter. 781 portable_code = GetOatAddress(portable_to_interpreter_bridge_offset_); 782 portable_is_interpreted = true; 783 } else { 784 CHECK(!orig->GetDeclaringClass()->IsInitialized()); 785 // We have code for a static method, but need to go through the resolution stub for class 786 // initialization. 787 portable_code = GetOatAddress(portable_resolution_trampoline_offset_); 788 } 789 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(portable_code); 790 #endif 791 // JNI entrypoint: 792 if (orig->IsNative()) { 793 // The native method's pointer is set to a stub to lookup via dlsym. 794 // Note this is not the code_ pointer, that is handled above. 795 copy->SetNativeMethod<kVerifyNone>(GetOatAddress(jni_dlsym_lookup_offset_)); 796 } else { 797 // Normal (non-abstract non-native) methods have various tables to relocate. 798 uint32_t native_gc_map_offset = orig->GetOatNativeGcMapOffset(); 799 const byte* native_gc_map = GetOatAddress(native_gc_map_offset); 800 copy->SetNativeGcMap<kVerifyNone>(reinterpret_cast<const uint8_t*>(native_gc_map)); 801 } 802 803 // Interpreter entrypoint: 804 // Set the interpreter entrypoint depending on whether there is compiled code or not. 805 uint32_t interpreter_code = (quick_is_interpreted && portable_is_interpreted) 806 ? interpreter_to_interpreter_bridge_offset_ 807 : interpreter_to_compiled_code_bridge_offset_; 808 copy->SetEntryPointFromInterpreter<kVerifyNone>( 809 reinterpret_cast<EntryPointFromInterpreter*>( 810 const_cast<byte*>(GetOatAddress(interpreter_code)))); 811 } 812 } 813 } 814 815 static OatHeader* GetOatHeaderFromElf(ElfFile* elf) { 816 Elf32_Shdr* data_sec = elf->FindSectionByName(".rodata"); 817 if (data_sec == nullptr) { 818 return nullptr; 819 } 820 return reinterpret_cast<OatHeader*>(elf->Begin() + data_sec->sh_offset); 821 } 822 823 void ImageWriter::PatchOatCodeAndMethods(File* elf_file) { 824 std::string error_msg; 825 std::unique_ptr<ElfFile> elf(ElfFile::Open(elf_file, PROT_READ|PROT_WRITE, 826 MAP_SHARED, &error_msg)); 827 if (elf.get() == nullptr) { 828 LOG(FATAL) << "Unable patch oat file: " << error_msg; 829 return; 830 } 831 if (!ElfPatcher::Patch(&compiler_driver_, elf.get(), oat_file_, 832 reinterpret_cast<uintptr_t>(oat_data_begin_), 833 GetImageAddressCallback, reinterpret_cast<void*>(this), 834 &error_msg)) { 835 LOG(FATAL) << "unable to patch oat file: " << error_msg; 836 return; 837 } 838 OatHeader* oat_header = GetOatHeaderFromElf(elf.get()); 839 CHECK(oat_header != nullptr); 840 CHECK(oat_header->IsValid()); 841 842 ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin()); 843 image_header->SetOatChecksum(oat_header->GetChecksum()); 844 } 845 846 } // namespace art 847