image_writer.cc revision a59dd80f9f48cb750d329d4d4af2d99d72b484d1
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 60using ::art::mirror::ArtField; 61using ::art::mirror::ArtMethod; 62using ::art::mirror::Class; 63using ::art::mirror::DexCache; 64using ::art::mirror::EntryPointFromInterpreter; 65using ::art::mirror::Object; 66using ::art::mirror::ObjectArray; 67using ::art::mirror::String; 68 69namespace art { 70 71bool 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 177void 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 210void 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 217bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const { 218 DCHECK(object != nullptr); 219 return object->GetLockWord(false).GetState() == LockWord::kForwardingAddress; 220} 221 222size_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 231bool 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 251void ImageWriter::ComputeLazyFieldsForImageClasses() { 252 ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); 253 class_linker->VisitClassesWithoutClassesLock(ComputeLazyFieldsForClassesVisitor, NULL); 254} 255 256bool 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 263void 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 291void 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 296bool ImageWriter::IsImageClass(Class* klass) { 297 return compiler_driver_.IsImageClass(klass->GetDescriptor().c_str()); 298} 299 300struct NonImageClasses { 301 ImageWriter* image_writer; 302 std::set<std::string>* non_image_classes; 303}; 304 305void ImageWriter::PruneNonImageClasses() { 306 if (compiler_driver_.GetImageClasses() == NULL) { 307 return; 308 } 309 Runtime* runtime = Runtime::Current(); 310 ClassLinker* class_linker = runtime->GetClassLinker(); 311 312 // Make a list of classes we would like to prune. 313 std::set<std::string> non_image_classes; 314 NonImageClasses context; 315 context.image_writer = this; 316 context.non_image_classes = &non_image_classes; 317 class_linker->VisitClasses(NonImageClassesVisitor, &context); 318 319 // Remove the undesired classes from the class roots. 320 for (const std::string& it : non_image_classes) { 321 class_linker->RemoveClass(it.c_str(), NULL); 322 } 323 324 // Clear references to removed classes from the DexCaches. 325 ArtMethod* resolution_method = runtime->GetResolutionMethod(); 326 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock()); 327 size_t dex_cache_count = class_linker->GetDexCacheCount(); 328 for (size_t idx = 0; idx < dex_cache_count; ++idx) { 329 DexCache* dex_cache = class_linker->GetDexCache(idx); 330 for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) { 331 Class* klass = dex_cache->GetResolvedType(i); 332 if (klass != NULL && !IsImageClass(klass)) { 333 dex_cache->SetResolvedType(i, NULL); 334 } 335 } 336 for (size_t i = 0; i < dex_cache->NumResolvedMethods(); i++) { 337 ArtMethod* method = dex_cache->GetResolvedMethod(i); 338 if (method != NULL && !IsImageClass(method->GetDeclaringClass())) { 339 dex_cache->SetResolvedMethod(i, resolution_method); 340 } 341 } 342 for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) { 343 ArtField* field = dex_cache->GetResolvedField(i); 344 if (field != NULL && !IsImageClass(field->GetDeclaringClass())) { 345 dex_cache->SetResolvedField(i, NULL); 346 } 347 } 348 } 349} 350 351bool ImageWriter::NonImageClassesVisitor(Class* klass, void* arg) { 352 NonImageClasses* context = reinterpret_cast<NonImageClasses*>(arg); 353 if (!context->image_writer->IsImageClass(klass)) { 354 context->non_image_classes->insert(klass->GetDescriptor()); 355 } 356 return true; 357} 358 359void ImageWriter::CheckNonImageClassesRemoved() 360 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 361 if (compiler_driver_.GetImageClasses() != nullptr) { 362 gc::Heap* heap = Runtime::Current()->GetHeap(); 363 ReaderMutexLock mu(Thread::Current(), *Locks::heap_bitmap_lock_); 364 heap->VisitObjects(CheckNonImageClassesRemovedCallback, this); 365 } 366} 367 368void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) { 369 ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg); 370 if (obj->IsClass()) { 371 Class* klass = obj->AsClass(); 372 if (!image_writer->IsImageClass(klass)) { 373 image_writer->DumpImageClasses(); 374 CHECK(image_writer->IsImageClass(klass)) << klass->GetDescriptor() 375 << " " << PrettyDescriptor(klass); 376 } 377 } 378} 379 380void ImageWriter::DumpImageClasses() { 381 CompilerDriver::DescriptorSet* image_classes = compiler_driver_.GetImageClasses(); 382 CHECK(image_classes != NULL); 383 for (const std::string& image_class : *image_classes) { 384 LOG(INFO) << " " << image_class; 385 } 386} 387 388void ImageWriter::CalculateObjectOffsets(Object* obj) { 389 DCHECK(obj != NULL); 390 // if it is a string, we want to intern it if its not interned. 391 if (obj->GetClass()->IsStringClass()) { 392 // we must be an interned string that was forward referenced and already assigned 393 if (IsImageOffsetAssigned(obj)) { 394 DCHECK_EQ(obj, obj->AsString()->Intern()); 395 return; 396 } 397 mirror::String* const interned = obj->AsString()->Intern(); 398 if (obj != interned) { 399 if (!IsImageOffsetAssigned(interned)) { 400 // interned obj is after us, allocate its location early 401 AssignImageOffset(interned); 402 } 403 // point those looking for this object to the interned version. 404 SetImageOffset(obj, GetImageOffset(interned)); 405 return; 406 } 407 // else (obj == interned), nothing to do but fall through to the normal case 408 } 409 410 AssignImageOffset(obj); 411} 412 413ObjectArray<Object>* ImageWriter::CreateImageRoots() const { 414 Runtime* runtime = Runtime::Current(); 415 ClassLinker* class_linker = runtime->GetClassLinker(); 416 Thread* self = Thread::Current(); 417 StackHandleScope<3> hs(self); 418 Handle<Class> object_array_class(hs.NewHandle( 419 class_linker->FindSystemClass(self, "[Ljava/lang/Object;"))); 420 421 // build an Object[] of all the DexCaches used in the source_space_. 422 // Since we can't hold the dex lock when allocating the dex_caches 423 // ObjectArray, we lock the dex lock twice, first to get the number 424 // of dex caches first and then lock it again to copy the dex 425 // caches. We check that the number of dex caches does not change. 426 size_t dex_cache_count; 427 { 428 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock()); 429 dex_cache_count = class_linker->GetDexCacheCount(); 430 } 431 Handle<ObjectArray<Object>> dex_caches( 432 hs.NewHandle(ObjectArray<Object>::Alloc(self, object_array_class.Get(), 433 dex_cache_count))); 434 CHECK(dex_caches.Get() != nullptr) << "Failed to allocate a dex cache array."; 435 { 436 ReaderMutexLock mu(Thread::Current(), *class_linker->DexLock()); 437 CHECK_EQ(dex_cache_count, class_linker->GetDexCacheCount()) 438 << "The number of dex caches changed."; 439 for (size_t i = 0; i < dex_cache_count; ++i) { 440 dex_caches->Set<false>(i, class_linker->GetDexCache(i)); 441 } 442 } 443 444 // build an Object[] of the roots needed to restore the runtime 445 Handle<ObjectArray<Object>> image_roots(hs.NewHandle( 446 ObjectArray<Object>::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax))); 447 image_roots->Set<false>(ImageHeader::kResolutionMethod, runtime->GetResolutionMethod()); 448 image_roots->Set<false>(ImageHeader::kImtConflictMethod, runtime->GetImtConflictMethod()); 449 image_roots->Set<false>(ImageHeader::kDefaultImt, runtime->GetDefaultImt()); 450 image_roots->Set<false>(ImageHeader::kCalleeSaveMethod, 451 runtime->GetCalleeSaveMethod(Runtime::kSaveAll)); 452 image_roots->Set<false>(ImageHeader::kRefsOnlySaveMethod, 453 runtime->GetCalleeSaveMethod(Runtime::kRefsOnly)); 454 image_roots->Set<false>(ImageHeader::kRefsAndArgsSaveMethod, 455 runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs)); 456 image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get()); 457 image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots()); 458 for (int i = 0; i < ImageHeader::kImageRootsMax; i++) { 459 CHECK(image_roots->Get(i) != NULL); 460 } 461 return image_roots.Get(); 462} 463 464// Walk instance fields of the given Class. Separate function to allow recursion on the super 465// class. 466void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) { 467 // Visit fields of parent classes first. 468 StackHandleScope<1> hs(Thread::Current()); 469 Handle<mirror::Class> h_class(hs.NewHandle(klass)); 470 mirror::Class* super = h_class->GetSuperClass(); 471 if (super != nullptr) { 472 WalkInstanceFields(obj, super); 473 } 474 // 475 size_t num_reference_fields = h_class->NumReferenceInstanceFields(); 476 for (size_t i = 0; i < num_reference_fields; ++i) { 477 mirror::ArtField* field = h_class->GetInstanceField(i); 478 MemberOffset field_offset = field->GetOffset(); 479 mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset); 480 if (value != nullptr) { 481 WalkFieldsInOrder(value); 482 } 483 } 484} 485 486// For an unvisited object, visit it then all its children found via fields. 487void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) { 488 if (!IsImageOffsetAssigned(obj)) { 489 // Walk instance fields of all objects 490 StackHandleScope<2> hs(Thread::Current()); 491 Handle<mirror::Object> h_obj(hs.NewHandle(obj)); 492 Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass())); 493 // visit the object itself. 494 CalculateObjectOffsets(h_obj.Get()); 495 WalkInstanceFields(h_obj.Get(), klass.Get()); 496 // Walk static fields of a Class. 497 if (h_obj->IsClass()) { 498 size_t num_static_fields = klass->NumReferenceStaticFields(); 499 for (size_t i = 0; i < num_static_fields; ++i) { 500 mirror::ArtField* field = klass->GetStaticField(i); 501 MemberOffset field_offset = field->GetOffset(); 502 mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset); 503 if (value != nullptr) { 504 WalkFieldsInOrder(value); 505 } 506 } 507 } else if (h_obj->IsObjectArray()) { 508 // Walk elements of an object array. 509 int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength(); 510 for (int32_t i = 0; i < length; i++) { 511 mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>(); 512 mirror::Object* value = obj_array->Get(i); 513 if (value != nullptr) { 514 WalkFieldsInOrder(value); 515 } 516 } 517 } 518 } 519} 520 521void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) { 522 ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg); 523 DCHECK(writer != nullptr); 524 writer->WalkFieldsInOrder(obj); 525} 526 527void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) { 528 CHECK_NE(0U, oat_loaded_size); 529 Thread* self = Thread::Current(); 530 StackHandleScope<1> hs(self); 531 Handle<ObjectArray<Object>> image_roots(hs.NewHandle(CreateImageRoots())); 532 533 gc::Heap* heap = Runtime::Current()->GetHeap(); 534 DCHECK_EQ(0U, image_end_); 535 536 // Leave space for the header, but do not write it yet, we need to 537 // know where image_roots is going to end up 538 image_end_ += RoundUp(sizeof(ImageHeader), 8); // 64-bit-alignment 539 540 { 541 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 542 // TODO: Image spaces only? 543 const char* old = self->StartAssertNoThreadSuspension("ImageWriter"); 544 DCHECK_LT(image_end_, image_->Size()); 545 // Clear any pre-existing monitors which may have been in the monitor words. 546 heap->VisitObjects(WalkFieldsCallback, this); 547 self->EndAssertNoThreadSuspension(old); 548 } 549 550 const byte* oat_file_begin = image_begin_ + RoundUp(image_end_, kPageSize); 551 const byte* oat_file_end = oat_file_begin + oat_loaded_size; 552 oat_data_begin_ = oat_file_begin + oat_data_offset; 553 const byte* oat_data_end = oat_data_begin_ + oat_file_->Size(); 554 555 // Return to write header at start of image with future location of image_roots. At this point, 556 // image_end_ is the size of the image (excluding bitmaps). 557 const size_t heap_bytes_per_bitmap_byte = kBitsPerByte * kObjectAlignment; 558 const size_t bitmap_bytes = RoundUp(image_end_, heap_bytes_per_bitmap_byte) / 559 heap_bytes_per_bitmap_byte; 560 ImageHeader image_header(PointerToLowMemUInt32(image_begin_), 561 static_cast<uint32_t>(image_end_), 562 RoundUp(image_end_, kPageSize), 563 RoundUp(bitmap_bytes, kPageSize), 564 PointerToLowMemUInt32(GetImageAddress(image_roots.Get())), 565 oat_file_->GetOatHeader().GetChecksum(), 566 PointerToLowMemUInt32(oat_file_begin), 567 PointerToLowMemUInt32(oat_data_begin_), 568 PointerToLowMemUInt32(oat_data_end), 569 PointerToLowMemUInt32(oat_file_end)); 570 memcpy(image_->Begin(), &image_header, sizeof(image_header)); 571 572 // Note that image_end_ is left at end of used space 573} 574 575void ImageWriter::CopyAndFixupObjects() 576 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 577 Thread* self = Thread::Current(); 578 const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter"); 579 gc::Heap* heap = Runtime::Current()->GetHeap(); 580 // TODO: heap validation can't handle this fix up pass 581 heap->DisableObjectValidation(); 582 // TODO: Image spaces only? 583 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 584 heap->VisitObjects(CopyAndFixupObjectsCallback, this); 585 // Fix up the object previously had hash codes. 586 for (const std::pair<mirror::Object*, uint32_t>& hash_pair : saved_hashes_) { 587 hash_pair.first->SetLockWord(LockWord::FromHashCode(hash_pair.second), false); 588 } 589 saved_hashes_.clear(); 590 self->EndAssertNoThreadSuspension(old_cause); 591} 592 593void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) { 594 DCHECK(obj != nullptr); 595 DCHECK(arg != nullptr); 596 ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg); 597 // see GetLocalAddress for similar computation 598 size_t offset = image_writer->GetImageOffset(obj); 599 byte* dst = image_writer->image_->Begin() + offset; 600 const byte* src = reinterpret_cast<const byte*>(obj); 601 size_t n = obj->SizeOf(); 602 DCHECK_LT(offset + n, image_writer->image_->Size()); 603 memcpy(dst, src, n); 604 Object* copy = reinterpret_cast<Object*>(dst); 605 // Write in a hash code of objects which have inflated monitors or a hash code in their monitor 606 // word. 607 copy->SetLockWord(LockWord(), false); 608 image_writer->FixupObject(obj, copy); 609} 610 611class FixupVisitor { 612 public: 613 FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) { 614 } 615 616 void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const 617 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 618 Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset); 619 // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the 620 // image. 621 copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>( 622 offset, image_writer_->GetImageAddress(ref)); 623 } 624 625 // java.lang.ref.Reference visitor. 626 void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const 627 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 628 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { 629 copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>( 630 mirror::Reference::ReferentOffset(), image_writer_->GetImageAddress(ref->GetReferent())); 631 } 632 633 protected: 634 ImageWriter* const image_writer_; 635 mirror::Object* const copy_; 636}; 637 638class FixupClassVisitor FINAL : public FixupVisitor { 639 public: 640 FixupClassVisitor(ImageWriter* image_writer, Object* copy) : FixupVisitor(image_writer, copy) { 641 } 642 643 void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const 644 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 645 DCHECK(obj->IsClass()); 646 FixupVisitor::operator()(obj, offset, false); 647 648 if (offset.Uint32Value() < mirror::Class::EmbeddedVTableOffset().Uint32Value()) { 649 return; 650 } 651 } 652 653 void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const 654 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 655 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { 656 LOG(FATAL) << "Reference not expected here."; 657 } 658}; 659 660void ImageWriter::FixupObject(Object* orig, Object* copy) { 661 DCHECK(orig != nullptr); 662 DCHECK(copy != nullptr); 663 if (kUseBakerOrBrooksReadBarrier) { 664 orig->AssertReadBarrierPointer(); 665 if (kUseBrooksReadBarrier) { 666 // Note the address 'copy' isn't the same as the image address of 'orig'. 667 copy->SetReadBarrierPointer(GetImageAddress(orig)); 668 DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig)); 669 } 670 } 671 if (orig->IsClass() && orig->AsClass()->ShouldHaveEmbeddedImtAndVTable()) { 672 FixupClassVisitor visitor(this, copy); 673 orig->VisitReferences<true /*visit class*/>(visitor, visitor); 674 } else { 675 FixupVisitor visitor(this, copy); 676 orig->VisitReferences<true /*visit class*/>(visitor, visitor); 677 } 678 if (orig->IsArtMethod<kVerifyNone>()) { 679 FixupMethod(orig->AsArtMethod<kVerifyNone>(), down_cast<ArtMethod*>(copy)); 680 } 681} 682 683const byte* ImageWriter::GetQuickCode(mirror::ArtMethod* method, bool* quick_is_interpreted) { 684 DCHECK(!method->IsResolutionMethod() && !method->IsImtConflictMethod() && 685 !method->IsAbstract()) << PrettyMethod(method); 686 687 // Use original code if it exists. Otherwise, set the code pointer to the resolution 688 // trampoline. 689 690 // Quick entrypoint: 691 const byte* quick_code = GetOatAddress(method->GetQuickOatCodeOffset()); 692 *quick_is_interpreted = false; 693 if (quick_code != nullptr && 694 (!method->IsStatic() || method->IsConstructor() || method->GetDeclaringClass()->IsInitialized())) { 695 // We have code for a non-static or initialized method, just use the code. 696 } else if (quick_code == nullptr && method->IsNative() && 697 (!method->IsStatic() || method->GetDeclaringClass()->IsInitialized())) { 698 // Non-static or initialized native method missing compiled code, use generic JNI version. 699 quick_code = GetOatAddress(quick_generic_jni_trampoline_offset_); 700 } else if (quick_code == nullptr && !method->IsNative()) { 701 // We don't have code at all for a non-native method, use the interpreter. 702 quick_code = GetOatAddress(quick_to_interpreter_bridge_offset_); 703 *quick_is_interpreted = true; 704 } else { 705 CHECK(!method->GetDeclaringClass()->IsInitialized()); 706 // We have code for a static method, but need to go through the resolution stub for class 707 // initialization. 708 quick_code = GetOatAddress(quick_resolution_trampoline_offset_); 709 } 710 return quick_code; 711} 712 713const byte* ImageWriter::GetQuickEntryPoint(mirror::ArtMethod* method) { 714 // Calculate the quick entry point following the same logic as FixupMethod() below. 715 // The resolution method has a special trampoline to call. 716 if (UNLIKELY(method == Runtime::Current()->GetResolutionMethod())) { 717 return GetOatAddress(quick_resolution_trampoline_offset_); 718 } else if (UNLIKELY(method == Runtime::Current()->GetImtConflictMethod())) { 719 return GetOatAddress(quick_imt_conflict_trampoline_offset_); 720 } else { 721 // We assume all methods have code. If they don't currently then we set them to the use the 722 // resolution trampoline. Abstract methods never have code and so we need to make sure their 723 // use results in an AbstractMethodError. We use the interpreter to achieve this. 724 if (UNLIKELY(method->IsAbstract())) { 725 return GetOatAddress(quick_to_interpreter_bridge_offset_); 726 } else { 727 bool quick_is_interpreted; 728 return GetQuickCode(method, &quick_is_interpreted); 729 } 730 } 731} 732 733void ImageWriter::FixupMethod(ArtMethod* orig, ArtMethod* copy) { 734 // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to 735 // oat_begin_ 736 737 // The resolution method has a special trampoline to call. 738 if (UNLIKELY(orig == Runtime::Current()->GetResolutionMethod())) { 739 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_)); 740 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_)); 741 } else if (UNLIKELY(orig == Runtime::Current()->GetImtConflictMethod())) { 742 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_imt_conflict_trampoline_offset_)); 743 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_imt_conflict_trampoline_offset_)); 744 } else { 745 // We assume all methods have code. If they don't currently then we set them to the use the 746 // resolution trampoline. Abstract methods never have code and so we need to make sure their 747 // use results in an AbstractMethodError. We use the interpreter to achieve this. 748 if (UNLIKELY(orig->IsAbstract())) { 749 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_to_interpreter_bridge_offset_)); 750 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_)); 751 copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*> 752 (const_cast<byte*>(GetOatAddress(interpreter_to_interpreter_bridge_offset_)))); 753 } else { 754 bool quick_is_interpreted; 755 const byte* quick_code = GetQuickCode(orig, &quick_is_interpreted); 756 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(quick_code); 757 758 // Portable entrypoint: 759 const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset()); 760 bool portable_is_interpreted = false; 761 if (portable_code != nullptr && 762 (!orig->IsStatic() || orig->IsConstructor() || orig->GetDeclaringClass()->IsInitialized())) { 763 // We have code for a non-static or initialized method, just use the code. 764 } else if (portable_code == nullptr && orig->IsNative() && 765 (!orig->IsStatic() || orig->GetDeclaringClass()->IsInitialized())) { 766 // Non-static or initialized native method missing compiled code, use generic JNI version. 767 // TODO: generic JNI support for LLVM. 768 portable_code = GetOatAddress(portable_resolution_trampoline_offset_); 769 } else if (portable_code == nullptr && !orig->IsNative()) { 770 // We don't have code at all for a non-native method, use the interpreter. 771 portable_code = GetOatAddress(portable_to_interpreter_bridge_offset_); 772 portable_is_interpreted = true; 773 } else { 774 CHECK(!orig->GetDeclaringClass()->IsInitialized()); 775 // We have code for a static method, but need to go through the resolution stub for class 776 // initialization. 777 portable_code = GetOatAddress(portable_resolution_trampoline_offset_); 778 } 779 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(portable_code); 780 781 // JNI entrypoint: 782 if (orig->IsNative()) { 783 // The native method's pointer is set to a stub to lookup via dlsym. 784 // Note this is not the code_ pointer, that is handled above. 785 copy->SetNativeMethod<kVerifyNone>(GetOatAddress(jni_dlsym_lookup_offset_)); 786 } else { 787 // Normal (non-abstract non-native) methods have various tables to relocate. 788 uint32_t native_gc_map_offset = orig->GetOatNativeGcMapOffset(); 789 const byte* native_gc_map = GetOatAddress(native_gc_map_offset); 790 copy->SetNativeGcMap<kVerifyNone>(reinterpret_cast<const uint8_t*>(native_gc_map)); 791 } 792 793 // Interpreter entrypoint: 794 // Set the interpreter entrypoint depending on whether there is compiled code or not. 795 uint32_t interpreter_code = (quick_is_interpreted && portable_is_interpreted) 796 ? interpreter_to_interpreter_bridge_offset_ 797 : interpreter_to_compiled_code_bridge_offset_; 798 copy->SetEntryPointFromInterpreter<kVerifyNone>( 799 reinterpret_cast<EntryPointFromInterpreter*>( 800 const_cast<byte*>(GetOatAddress(interpreter_code)))); 801 } 802 } 803} 804 805static OatHeader* GetOatHeaderFromElf(ElfFile* elf) { 806 Elf32_Shdr* data_sec = elf->FindSectionByName(".rodata"); 807 if (data_sec == nullptr) { 808 return nullptr; 809 } 810 return reinterpret_cast<OatHeader*>(elf->Begin() + data_sec->sh_offset); 811} 812 813void ImageWriter::PatchOatCodeAndMethods(File* elf_file) { 814 std::string error_msg; 815 std::unique_ptr<ElfFile> elf(ElfFile::Open(elf_file, PROT_READ|PROT_WRITE, 816 MAP_SHARED, &error_msg)); 817 if (elf.get() == nullptr) { 818 LOG(FATAL) << "Unable patch oat file: " << error_msg; 819 return; 820 } 821 if (!ElfPatcher::Patch(&compiler_driver_, elf.get(), oat_file_, 822 reinterpret_cast<uintptr_t>(oat_data_begin_), 823 GetImageAddressCallback, reinterpret_cast<void*>(this), 824 &error_msg)) { 825 LOG(FATAL) << "unable to patch oat file: " << error_msg; 826 return; 827 } 828 OatHeader* oat_header = GetOatHeaderFromElf(elf.get()); 829 CHECK(oat_header != nullptr); 830 CHECK(oat_header->IsValid()); 831 832 ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin()); 833 image_header->SetOatChecksum(oat_header->GetChecksum()); 834} 835 836} // namespace art 837