image_writer.cc revision 1fb463e42cf1d67595cff66d19c0f99e3046f4c4
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 std::string temp; 298 return compiler_driver_.IsImageClass(klass->GetDescriptor(&temp)); 299} 300 301struct NonImageClasses { 302 ImageWriter* image_writer; 303 std::set<std::string>* non_image_classes; 304}; 305 306void 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 352bool 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 361void 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 370void 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 383void 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 391void 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 416ObjectArray<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::kImtUnimplementedMethod, 453 runtime->GetImtUnimplementedMethod()); 454 image_roots->Set<false>(ImageHeader::kDefaultImt, runtime->GetDefaultImt()); 455 image_roots->Set<false>(ImageHeader::kCalleeSaveMethod, 456 runtime->GetCalleeSaveMethod(Runtime::kSaveAll)); 457 image_roots->Set<false>(ImageHeader::kRefsOnlySaveMethod, 458 runtime->GetCalleeSaveMethod(Runtime::kRefsOnly)); 459 image_roots->Set<false>(ImageHeader::kRefsAndArgsSaveMethod, 460 runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs)); 461 image_roots->Set<false>(ImageHeader::kDexCaches, dex_caches.Get()); 462 image_roots->Set<false>(ImageHeader::kClassRoots, class_linker->GetClassRoots()); 463 for (int i = 0; i < ImageHeader::kImageRootsMax; i++) { 464 CHECK(image_roots->Get(i) != NULL); 465 } 466 return image_roots.Get(); 467} 468 469// Walk instance fields of the given Class. Separate function to allow recursion on the super 470// class. 471void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) { 472 // Visit fields of parent classes first. 473 StackHandleScope<1> hs(Thread::Current()); 474 Handle<mirror::Class> h_class(hs.NewHandle(klass)); 475 mirror::Class* super = h_class->GetSuperClass(); 476 if (super != nullptr) { 477 WalkInstanceFields(obj, super); 478 } 479 // 480 size_t num_reference_fields = h_class->NumReferenceInstanceFields(); 481 for (size_t i = 0; i < num_reference_fields; ++i) { 482 mirror::ArtField* field = h_class->GetInstanceField(i); 483 MemberOffset field_offset = field->GetOffset(); 484 mirror::Object* value = obj->GetFieldObject<mirror::Object>(field_offset); 485 if (value != nullptr) { 486 WalkFieldsInOrder(value); 487 } 488 } 489} 490 491// For an unvisited object, visit it then all its children found via fields. 492void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) { 493 if (!IsImageOffsetAssigned(obj)) { 494 // Walk instance fields of all objects 495 StackHandleScope<2> hs(Thread::Current()); 496 Handle<mirror::Object> h_obj(hs.NewHandle(obj)); 497 Handle<mirror::Class> klass(hs.NewHandle(obj->GetClass())); 498 // visit the object itself. 499 CalculateObjectOffsets(h_obj.Get()); 500 WalkInstanceFields(h_obj.Get(), klass.Get()); 501 // Walk static fields of a Class. 502 if (h_obj->IsClass()) { 503 size_t num_static_fields = klass->NumReferenceStaticFields(); 504 for (size_t i = 0; i < num_static_fields; ++i) { 505 mirror::ArtField* field = klass->GetStaticField(i); 506 MemberOffset field_offset = field->GetOffset(); 507 mirror::Object* value = h_obj->GetFieldObject<mirror::Object>(field_offset); 508 if (value != nullptr) { 509 WalkFieldsInOrder(value); 510 } 511 } 512 } else if (h_obj->IsObjectArray()) { 513 // Walk elements of an object array. 514 int32_t length = h_obj->AsObjectArray<mirror::Object>()->GetLength(); 515 for (int32_t i = 0; i < length; i++) { 516 mirror::ObjectArray<mirror::Object>* obj_array = h_obj->AsObjectArray<mirror::Object>(); 517 mirror::Object* value = obj_array->Get(i); 518 if (value != nullptr) { 519 WalkFieldsInOrder(value); 520 } 521 } 522 } 523 } 524} 525 526void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) { 527 ImageWriter* writer = reinterpret_cast<ImageWriter*>(arg); 528 DCHECK(writer != nullptr); 529 writer->WalkFieldsInOrder(obj); 530} 531 532void ImageWriter::CalculateNewObjectOffsets(size_t oat_loaded_size, size_t oat_data_offset) { 533 CHECK_NE(0U, oat_loaded_size); 534 Thread* self = Thread::Current(); 535 StackHandleScope<1> hs(self); 536 Handle<ObjectArray<Object>> image_roots(hs.NewHandle(CreateImageRoots())); 537 538 gc::Heap* heap = Runtime::Current()->GetHeap(); 539 DCHECK_EQ(0U, image_end_); 540 541 // Leave space for the header, but do not write it yet, we need to 542 // know where image_roots is going to end up 543 image_end_ += RoundUp(sizeof(ImageHeader), 8); // 64-bit-alignment 544 545 { 546 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 547 // TODO: Image spaces only? 548 const char* old = self->StartAssertNoThreadSuspension("ImageWriter"); 549 DCHECK_LT(image_end_, image_->Size()); 550 // Clear any pre-existing monitors which may have been in the monitor words. 551 heap->VisitObjects(WalkFieldsCallback, this); 552 self->EndAssertNoThreadSuspension(old); 553 } 554 555 const byte* oat_file_begin = image_begin_ + RoundUp(image_end_, kPageSize); 556 const byte* oat_file_end = oat_file_begin + oat_loaded_size; 557 oat_data_begin_ = oat_file_begin + oat_data_offset; 558 const byte* oat_data_end = oat_data_begin_ + oat_file_->Size(); 559 560 // Return to write header at start of image with future location of image_roots. At this point, 561 // image_end_ is the size of the image (excluding bitmaps). 562 const size_t heap_bytes_per_bitmap_byte = kBitsPerByte * kObjectAlignment; 563 const size_t bitmap_bytes = RoundUp(image_end_, heap_bytes_per_bitmap_byte) / 564 heap_bytes_per_bitmap_byte; 565 ImageHeader image_header(PointerToLowMemUInt32(image_begin_), 566 static_cast<uint32_t>(image_end_), 567 RoundUp(image_end_, kPageSize), 568 RoundUp(bitmap_bytes, kPageSize), 569 PointerToLowMemUInt32(GetImageAddress(image_roots.Get())), 570 oat_file_->GetOatHeader().GetChecksum(), 571 PointerToLowMemUInt32(oat_file_begin), 572 PointerToLowMemUInt32(oat_data_begin_), 573 PointerToLowMemUInt32(oat_data_end), 574 PointerToLowMemUInt32(oat_file_end)); 575 memcpy(image_->Begin(), &image_header, sizeof(image_header)); 576 577 // Note that image_end_ is left at end of used space 578} 579 580void ImageWriter::CopyAndFixupObjects() 581 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { 582 Thread* self = Thread::Current(); 583 const char* old_cause = self->StartAssertNoThreadSuspension("ImageWriter"); 584 gc::Heap* heap = Runtime::Current()->GetHeap(); 585 // TODO: heap validation can't handle this fix up pass 586 heap->DisableObjectValidation(); 587 // TODO: Image spaces only? 588 WriterMutexLock mu(self, *Locks::heap_bitmap_lock_); 589 heap->VisitObjects(CopyAndFixupObjectsCallback, this); 590 // Fix up the object previously had hash codes. 591 for (const std::pair<mirror::Object*, uint32_t>& hash_pair : saved_hashes_) { 592 hash_pair.first->SetLockWord(LockWord::FromHashCode(hash_pair.second), false); 593 } 594 saved_hashes_.clear(); 595 self->EndAssertNoThreadSuspension(old_cause); 596} 597 598void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) { 599 DCHECK(obj != nullptr); 600 DCHECK(arg != nullptr); 601 ImageWriter* image_writer = reinterpret_cast<ImageWriter*>(arg); 602 // see GetLocalAddress for similar computation 603 size_t offset = image_writer->GetImageOffset(obj); 604 byte* dst = image_writer->image_->Begin() + offset; 605 const byte* src = reinterpret_cast<const byte*>(obj); 606 size_t n = obj->SizeOf(); 607 DCHECK_LT(offset + n, image_writer->image_->Size()); 608 memcpy(dst, src, n); 609 Object* copy = reinterpret_cast<Object*>(dst); 610 // Write in a hash code of objects which have inflated monitors or a hash code in their monitor 611 // word. 612 copy->SetLockWord(LockWord(), false); 613 image_writer->FixupObject(obj, copy); 614} 615 616class FixupVisitor { 617 public: 618 FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) { 619 } 620 621 void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const 622 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 623 Object* ref = obj->GetFieldObject<Object, kVerifyNone>(offset); 624 // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the 625 // image. 626 copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>( 627 offset, image_writer_->GetImageAddress(ref)); 628 } 629 630 // java.lang.ref.Reference visitor. 631 void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const 632 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 633 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { 634 copy_->SetFieldObjectWithoutWriteBarrier<false, true, kVerifyNone>( 635 mirror::Reference::ReferentOffset(), image_writer_->GetImageAddress(ref->GetReferent())); 636 } 637 638 protected: 639 ImageWriter* const image_writer_; 640 mirror::Object* const copy_; 641}; 642 643class FixupClassVisitor FINAL : public FixupVisitor { 644 public: 645 FixupClassVisitor(ImageWriter* image_writer, Object* copy) : FixupVisitor(image_writer, copy) { 646 } 647 648 void operator()(Object* obj, MemberOffset offset, bool /*is_static*/) const 649 EXCLUSIVE_LOCKS_REQUIRED(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { 650 DCHECK(obj->IsClass()); 651 FixupVisitor::operator()(obj, offset, false); 652 653 if (offset.Uint32Value() < mirror::Class::EmbeddedVTableOffset().Uint32Value()) { 654 return; 655 } 656 } 657 658 void operator()(mirror::Class* /*klass*/, mirror::Reference* ref) const 659 SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) 660 EXCLUSIVE_LOCKS_REQUIRED(Locks::heap_bitmap_lock_) { 661 LOG(FATAL) << "Reference not expected here."; 662 } 663}; 664 665void ImageWriter::FixupObject(Object* orig, Object* copy) { 666 DCHECK(orig != nullptr); 667 DCHECK(copy != nullptr); 668 if (kUseBakerOrBrooksReadBarrier) { 669 orig->AssertReadBarrierPointer(); 670 if (kUseBrooksReadBarrier) { 671 // Note the address 'copy' isn't the same as the image address of 'orig'. 672 copy->SetReadBarrierPointer(GetImageAddress(orig)); 673 DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig)); 674 } 675 } 676 if (orig->IsClass() && orig->AsClass()->ShouldHaveEmbeddedImtAndVTable()) { 677 FixupClassVisitor visitor(this, copy); 678 orig->VisitReferences<true /*visit class*/>(visitor, visitor); 679 } else { 680 FixupVisitor visitor(this, copy); 681 orig->VisitReferences<true /*visit class*/>(visitor, visitor); 682 } 683 if (orig->IsArtMethod<kVerifyNone>()) { 684 FixupMethod(orig->AsArtMethod<kVerifyNone>(), down_cast<ArtMethod*>(copy)); 685 } 686} 687 688const byte* ImageWriter::GetQuickCode(mirror::ArtMethod* method, bool* quick_is_interpreted) { 689 DCHECK(!method->IsResolutionMethod() && !method->IsImtConflictMethod() && 690 !method->IsImtUnimplementedMethod() && !method->IsAbstract()) << PrettyMethod(method); 691 692 // Use original code if it exists. Otherwise, set the code pointer to the resolution 693 // trampoline. 694 695 // Quick entrypoint: 696 const byte* quick_code = GetOatAddress(method->GetQuickOatCodeOffset()); 697 *quick_is_interpreted = false; 698 if (quick_code != nullptr && 699 (!method->IsStatic() || method->IsConstructor() || method->GetDeclaringClass()->IsInitialized())) { 700 // We have code for a non-static or initialized method, just use the code. 701 } else if (quick_code == nullptr && method->IsNative() && 702 (!method->IsStatic() || method->GetDeclaringClass()->IsInitialized())) { 703 // Non-static or initialized native method missing compiled code, use generic JNI version. 704 quick_code = GetOatAddress(quick_generic_jni_trampoline_offset_); 705 } else if (quick_code == nullptr && !method->IsNative()) { 706 // We don't have code at all for a non-native method, use the interpreter. 707 quick_code = GetOatAddress(quick_to_interpreter_bridge_offset_); 708 *quick_is_interpreted = true; 709 } else { 710 CHECK(!method->GetDeclaringClass()->IsInitialized()); 711 // We have code for a static method, but need to go through the resolution stub for class 712 // initialization. 713 quick_code = GetOatAddress(quick_resolution_trampoline_offset_); 714 } 715 return quick_code; 716} 717 718const byte* ImageWriter::GetQuickEntryPoint(mirror::ArtMethod* method) { 719 // Calculate the quick entry point following the same logic as FixupMethod() below. 720 // The resolution method has a special trampoline to call. 721 Runtime* runtime = Runtime::Current(); 722 if (UNLIKELY(method == runtime->GetResolutionMethod())) { 723 return GetOatAddress(quick_resolution_trampoline_offset_); 724 } else if (UNLIKELY(method == runtime->GetImtConflictMethod() || 725 method == runtime->GetImtUnimplementedMethod())) { 726 return GetOatAddress(quick_imt_conflict_trampoline_offset_); 727 } else { 728 // We assume all methods have code. If they don't currently then we set them to the use the 729 // resolution trampoline. Abstract methods never have code and so we need to make sure their 730 // use results in an AbstractMethodError. We use the interpreter to achieve this. 731 if (UNLIKELY(method->IsAbstract())) { 732 return GetOatAddress(quick_to_interpreter_bridge_offset_); 733 } else { 734 bool quick_is_interpreted; 735 return GetQuickCode(method, &quick_is_interpreted); 736 } 737 } 738} 739 740void ImageWriter::FixupMethod(ArtMethod* orig, ArtMethod* copy) { 741 // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to 742 // oat_begin_ 743 744 // The resolution method has a special trampoline to call. 745 Runtime* runtime = Runtime::Current(); 746 if (UNLIKELY(orig == runtime->GetResolutionMethod())) { 747#if defined(ART_USE_PORTABLE_COMPILER) 748 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_resolution_trampoline_offset_)); 749#endif 750 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_resolution_trampoline_offset_)); 751 } else if (UNLIKELY(orig == runtime->GetImtConflictMethod() || 752 orig == runtime->GetImtUnimplementedMethod())) { 753#if defined(ART_USE_PORTABLE_COMPILER) 754 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_imt_conflict_trampoline_offset_)); 755#endif 756 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_imt_conflict_trampoline_offset_)); 757 } else { 758 // We assume all methods have code. If they don't currently then we set them to the use the 759 // resolution trampoline. Abstract methods never have code and so we need to make sure their 760 // use results in an AbstractMethodError. We use the interpreter to achieve this. 761 if (UNLIKELY(orig->IsAbstract())) { 762#if defined(ART_USE_PORTABLE_COMPILER) 763 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(GetOatAddress(portable_to_interpreter_bridge_offset_)); 764#endif 765 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(GetOatAddress(quick_to_interpreter_bridge_offset_)); 766 copy->SetEntryPointFromInterpreter<kVerifyNone>(reinterpret_cast<EntryPointFromInterpreter*> 767 (const_cast<byte*>(GetOatAddress(interpreter_to_interpreter_bridge_offset_)))); 768 } else { 769 bool quick_is_interpreted; 770 const byte* quick_code = GetQuickCode(orig, &quick_is_interpreted); 771 copy->SetEntryPointFromQuickCompiledCode<kVerifyNone>(quick_code); 772 773 // Portable entrypoint: 774 bool portable_is_interpreted = false; 775#if defined(ART_USE_PORTABLE_COMPILER) 776 const byte* portable_code = GetOatAddress(orig->GetPortableOatCodeOffset()); 777 if (portable_code != nullptr && 778 (!orig->IsStatic() || orig->IsConstructor() || orig->GetDeclaringClass()->IsInitialized())) { 779 // We have code for a non-static or initialized method, just use the code. 780 } else if (portable_code == nullptr && orig->IsNative() && 781 (!orig->IsStatic() || orig->GetDeclaringClass()->IsInitialized())) { 782 // Non-static or initialized native method missing compiled code, use generic JNI version. 783 // TODO: generic JNI support for LLVM. 784 portable_code = GetOatAddress(portable_resolution_trampoline_offset_); 785 } else if (portable_code == nullptr && !orig->IsNative()) { 786 // We don't have code at all for a non-native method, use the interpreter. 787 portable_code = GetOatAddress(portable_to_interpreter_bridge_offset_); 788 portable_is_interpreted = true; 789 } else { 790 CHECK(!orig->GetDeclaringClass()->IsInitialized()); 791 // We have code for a static method, but need to go through the resolution stub for class 792 // initialization. 793 portable_code = GetOatAddress(portable_resolution_trampoline_offset_); 794 } 795 copy->SetEntryPointFromPortableCompiledCode<kVerifyNone>(portable_code); 796#endif 797 // JNI entrypoint: 798 if (orig->IsNative()) { 799 // The native method's pointer is set to a stub to lookup via dlsym. 800 // Note this is not the code_ pointer, that is handled above. 801 copy->SetNativeMethod<kVerifyNone>(GetOatAddress(jni_dlsym_lookup_offset_)); 802 } else { 803 // Normal (non-abstract non-native) methods have various tables to relocate. 804 uint32_t native_gc_map_offset = orig->GetOatNativeGcMapOffset(); 805 const byte* native_gc_map = GetOatAddress(native_gc_map_offset); 806 copy->SetNativeGcMap<kVerifyNone>(reinterpret_cast<const uint8_t*>(native_gc_map)); 807 } 808 809 // Interpreter entrypoint: 810 // Set the interpreter entrypoint depending on whether there is compiled code or not. 811 uint32_t interpreter_code = (quick_is_interpreted && portable_is_interpreted) 812 ? interpreter_to_interpreter_bridge_offset_ 813 : interpreter_to_compiled_code_bridge_offset_; 814 copy->SetEntryPointFromInterpreter<kVerifyNone>( 815 reinterpret_cast<EntryPointFromInterpreter*>( 816 const_cast<byte*>(GetOatAddress(interpreter_code)))); 817 } 818 } 819} 820 821static OatHeader* GetOatHeaderFromElf(ElfFile* elf) { 822 Elf32_Shdr* data_sec = elf->FindSectionByName(".rodata"); 823 if (data_sec == nullptr) { 824 return nullptr; 825 } 826 return reinterpret_cast<OatHeader*>(elf->Begin() + data_sec->sh_offset); 827} 828 829void ImageWriter::PatchOatCodeAndMethods(File* elf_file) { 830 std::string error_msg; 831 std::unique_ptr<ElfFile> elf(ElfFile::Open(elf_file, PROT_READ|PROT_WRITE, 832 MAP_SHARED, &error_msg)); 833 if (elf.get() == nullptr) { 834 LOG(FATAL) << "Unable patch oat file: " << error_msg; 835 return; 836 } 837 if (!ElfPatcher::Patch(&compiler_driver_, elf.get(), oat_file_, 838 reinterpret_cast<uintptr_t>(oat_data_begin_), 839 GetImageAddressCallback, reinterpret_cast<void*>(this), 840 &error_msg)) { 841 LOG(FATAL) << "unable to patch oat file: " << error_msg; 842 return; 843 } 844 OatHeader* oat_header = GetOatHeaderFromElf(elf.get()); 845 CHECK(oat_header != nullptr); 846 CHECK(oat_header->IsValid()); 847 848 ImageHeader* image_header = reinterpret_cast<ImageHeader*>(image_->Begin()); 849 image_header->SetOatChecksum(oat_header->GetChecksum()); 850} 851 852} // namespace art 853