/* * Copyright (C) 2011 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ #include "image_writer.h" #include #include #include #include #include "art_field-inl.h" #include "art_method-inl.h" #include "base/logging.h" #include "base/unix_file/fd_file.h" #include "class_linker-inl.h" #include "compiled_method.h" #include "dex_file-inl.h" #include "driver/compiler_driver.h" #include "elf_file.h" #include "elf_utils.h" #include "elf_writer.h" #include "gc/accounting/card_table-inl.h" #include "gc/accounting/heap_bitmap.h" #include "gc/accounting/space_bitmap-inl.h" #include "gc/heap.h" #include "gc/space/large_object_space.h" #include "gc/space/space-inl.h" #include "globals.h" #include "image.h" #include "intern_table.h" #include "linear_alloc.h" #include "lock_word.h" #include "mirror/abstract_method.h" #include "mirror/array-inl.h" #include "mirror/class-inl.h" #include "mirror/class_loader.h" #include "mirror/dex_cache-inl.h" #include "mirror/method.h" #include "mirror/object-inl.h" #include "mirror/object_array-inl.h" #include "mirror/string-inl.h" #include "oat.h" #include "oat_file.h" #include "runtime.h" #include "scoped_thread_state_change.h" #include "handle_scope-inl.h" #include "utils/dex_cache_arrays_layout-inl.h" using ::art::mirror::Class; using ::art::mirror::DexCache; using ::art::mirror::Object; using ::art::mirror::ObjectArray; using ::art::mirror::String; namespace art { // Separate objects into multiple bins to optimize dirty memory use. static constexpr bool kBinObjects = true; static void CheckNoDexObjectsCallback(Object* obj, void* arg ATTRIBUTE_UNUSED) SHARED_REQUIRES(Locks::mutator_lock_) { Class* klass = obj->GetClass(); CHECK_NE(PrettyClass(klass), "com.android.dex.Dex"); } static void CheckNoDexObjects() { ScopedObjectAccess soa(Thread::Current()); Runtime::Current()->GetHeap()->VisitObjects(CheckNoDexObjectsCallback, nullptr); } bool ImageWriter::PrepareImageAddressSpace() { target_ptr_size_ = InstructionSetPointerSize(compiler_driver_.GetInstructionSet()); { ScopedObjectAccess soa(Thread::Current()); PruneNonImageClasses(); // Remove junk ComputeLazyFieldsForImageClasses(); // Add useful information } gc::Heap* heap = Runtime::Current()->GetHeap(); heap->CollectGarbage(false); // Remove garbage. // Dex caches must not have their dex fields set in the image. These are memory buffers of mapped // dex files. // // We may open them in the unstarted-runtime code for class metadata. Their fields should all be // reset in PruneNonImageClasses and the objects reclaimed in the GC. Make sure that's actually // true. if (kIsDebugBuild) { CheckNoDexObjects(); } if (kIsDebugBuild) { ScopedObjectAccess soa(Thread::Current()); CheckNonImageClassesRemoved(); } { ScopedObjectAccess soa(Thread::Current()); CalculateNewObjectOffsets(); } // This needs to happen after CalculateNewObjectOffsets since it relies on intern_table_bytes_ and // bin size sums being calculated. if (!AllocMemory()) { return false; } return true; } bool ImageWriter::Write(const std::string& image_filename, const std::string& oat_filename, const std::string& oat_location) { CHECK(!image_filename.empty()); ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); std::unique_ptr oat_file(OS::OpenFileReadWrite(oat_filename.c_str())); if (oat_file.get() == nullptr) { PLOG(ERROR) << "Failed to open oat file " << oat_filename << " for " << oat_location; return false; } std::string error_msg; oat_file_ = OatFile::OpenReadable(oat_file.get(), oat_location, nullptr, &error_msg); if (oat_file_ == nullptr) { PLOG(ERROR) << "Failed to open writable oat file " << oat_filename << " for " << oat_location << ": " << error_msg; oat_file->Erase(); return false; } CHECK_EQ(class_linker->RegisterOatFile(oat_file_), oat_file_); interpreter_to_interpreter_bridge_offset_ = oat_file_->GetOatHeader().GetInterpreterToInterpreterBridgeOffset(); interpreter_to_compiled_code_bridge_offset_ = oat_file_->GetOatHeader().GetInterpreterToCompiledCodeBridgeOffset(); jni_dlsym_lookup_offset_ = oat_file_->GetOatHeader().GetJniDlsymLookupOffset(); quick_generic_jni_trampoline_offset_ = oat_file_->GetOatHeader().GetQuickGenericJniTrampolineOffset(); quick_imt_conflict_trampoline_offset_ = oat_file_->GetOatHeader().GetQuickImtConflictTrampolineOffset(); quick_resolution_trampoline_offset_ = oat_file_->GetOatHeader().GetQuickResolutionTrampolineOffset(); quick_to_interpreter_bridge_offset_ = oat_file_->GetOatHeader().GetQuickToInterpreterBridgeOffset(); size_t oat_loaded_size = 0; size_t oat_data_offset = 0; ElfWriter::GetOatElfInformation(oat_file.get(), &oat_loaded_size, &oat_data_offset); { ScopedObjectAccess soa(Thread::Current()); CreateHeader(oat_loaded_size, oat_data_offset); CopyAndFixupNativeData(); // TODO: heap validation can't handle these fix up passes. Runtime::Current()->GetHeap()->DisableObjectValidation(); CopyAndFixupObjects(); } SetOatChecksumFromElfFile(oat_file.get()); if (oat_file->FlushCloseOrErase() != 0) { LOG(ERROR) << "Failed to flush and close oat file " << oat_filename << " for " << oat_location; return false; } std::unique_ptr image_file(OS::CreateEmptyFile(image_filename.c_str())); ImageHeader* image_header = reinterpret_cast(image_->Begin()); if (image_file.get() == nullptr) { LOG(ERROR) << "Failed to open image file " << image_filename; return false; } if (fchmod(image_file->Fd(), 0644) != 0) { PLOG(ERROR) << "Failed to make image file world readable: " << image_filename; image_file->Erase(); return EXIT_FAILURE; } // Write out the image + fields + methods. const auto write_count = image_header->GetImageSize(); if (!image_file->WriteFully(image_->Begin(), write_count)) { PLOG(ERROR) << "Failed to write image file " << image_filename; image_file->Erase(); return false; } // Write out the image bitmap at the page aligned start of the image end. const ImageSection& bitmap_section = image_header->GetImageSection(ImageHeader::kSectionImageBitmap); CHECK_ALIGNED(bitmap_section.Offset(), kPageSize); if (!image_file->Write(reinterpret_cast(image_bitmap_->Begin()), bitmap_section.Size(), bitmap_section.Offset())) { PLOG(ERROR) << "Failed to write image file " << image_filename; image_file->Erase(); return false; } CHECK_EQ(bitmap_section.End(), static_cast(image_file->GetLength())); if (image_file->FlushCloseOrErase() != 0) { PLOG(ERROR) << "Failed to flush and close image file " << image_filename; return false; } return true; } void ImageWriter::SetImageOffset(mirror::Object* object, size_t offset) { DCHECK(object != nullptr); DCHECK_NE(offset, 0U); // The object is already deflated from when we set the bin slot. Just overwrite the lock word. object->SetLockWord(LockWord::FromForwardingAddress(offset), false); DCHECK_EQ(object->GetLockWord(false).ReadBarrierState(), 0u); DCHECK(IsImageOffsetAssigned(object)); } void ImageWriter::UpdateImageOffset(mirror::Object* obj, uintptr_t offset) { DCHECK(IsImageOffsetAssigned(obj)) << obj << " " << offset; obj->SetLockWord(LockWord::FromForwardingAddress(offset), false); DCHECK_EQ(obj->GetLockWord(false).ReadBarrierState(), 0u); } void ImageWriter::AssignImageOffset(mirror::Object* object, ImageWriter::BinSlot bin_slot) { DCHECK(object != nullptr); DCHECK_NE(image_objects_offset_begin_, 0u); size_t bin_slot_offset = bin_slot_offsets_[bin_slot.GetBin()]; size_t new_offset = bin_slot_offset + bin_slot.GetIndex(); DCHECK_ALIGNED(new_offset, kObjectAlignment); SetImageOffset(object, new_offset); DCHECK_LT(new_offset, image_end_); } bool ImageWriter::IsImageOffsetAssigned(mirror::Object* object) const { // Will also return true if the bin slot was assigned since we are reusing the lock word. DCHECK(object != nullptr); return object->GetLockWord(false).GetState() == LockWord::kForwardingAddress; } size_t ImageWriter::GetImageOffset(mirror::Object* object) const { DCHECK(object != nullptr); DCHECK(IsImageOffsetAssigned(object)); LockWord lock_word = object->GetLockWord(false); size_t offset = lock_word.ForwardingAddress(); DCHECK_LT(offset, image_end_); return offset; } void ImageWriter::SetImageBinSlot(mirror::Object* object, BinSlot bin_slot) { DCHECK(object != nullptr); DCHECK(!IsImageOffsetAssigned(object)); DCHECK(!IsImageBinSlotAssigned(object)); // Before we stomp over the lock word, save the hash code for later. Monitor::Deflate(Thread::Current(), object);; LockWord lw(object->GetLockWord(false)); switch (lw.GetState()) { case LockWord::kFatLocked: { LOG(FATAL) << "Fat locked object " << object << " found during object copy"; break; } case LockWord::kThinLocked: { LOG(FATAL) << "Thin locked object " << object << " found during object copy"; break; } case LockWord::kUnlocked: // No hash, don't need to save it. break; case LockWord::kHashCode: DCHECK(saved_hashcode_map_.find(object) == saved_hashcode_map_.end()); saved_hashcode_map_.emplace(object, lw.GetHashCode()); break; default: LOG(FATAL) << "Unreachable."; UNREACHABLE(); } object->SetLockWord(LockWord::FromForwardingAddress(bin_slot.Uint32Value()), false); DCHECK_EQ(object->GetLockWord(false).ReadBarrierState(), 0u); DCHECK(IsImageBinSlotAssigned(object)); } void ImageWriter::PrepareDexCacheArraySlots() { ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); Thread* const self = Thread::Current(); ReaderMutexLock mu(self, *class_linker->DexLock()); uint32_t size = 0u; for (jobject weak_root : class_linker->GetDexCaches()) { mirror::DexCache* dex_cache = down_cast(self->DecodeJObject(weak_root)); if (dex_cache == nullptr) { continue; } const DexFile* dex_file = dex_cache->GetDexFile(); dex_cache_array_starts_.Put(dex_file, size); DexCacheArraysLayout layout(target_ptr_size_, dex_file); DCHECK(layout.Valid()); DCHECK_EQ(dex_file->NumTypeIds() != 0u, dex_cache->GetResolvedTypes() != nullptr); AddDexCacheArrayRelocation(dex_cache->GetResolvedTypes(), size + layout.TypesOffset()); DCHECK_EQ(dex_file->NumMethodIds() != 0u, dex_cache->GetResolvedMethods() != nullptr); AddDexCacheArrayRelocation(dex_cache->GetResolvedMethods(), size + layout.MethodsOffset()); DCHECK_EQ(dex_file->NumFieldIds() != 0u, dex_cache->GetResolvedFields() != nullptr); AddDexCacheArrayRelocation(dex_cache->GetResolvedFields(), size + layout.FieldsOffset()); DCHECK_EQ(dex_file->NumStringIds() != 0u, dex_cache->GetStrings() != nullptr); AddDexCacheArrayRelocation(dex_cache->GetStrings(), size + layout.StringsOffset()); size += layout.Size(); } // Set the slot size early to avoid DCHECK() failures in IsImageBinSlotAssigned() // when AssignImageBinSlot() assigns their indexes out or order. bin_slot_sizes_[kBinDexCacheArray] = size; } void ImageWriter::AddDexCacheArrayRelocation(void* array, size_t offset) { if (array != nullptr) { native_object_relocations_.emplace( array, NativeObjectRelocation { offset, kNativeObjectRelocationTypeDexCacheArray }); } } void ImageWriter::AddMethodPointerArray(mirror::PointerArray* arr) { DCHECK(arr != nullptr); if (kIsDebugBuild) { for (size_t i = 0, len = arr->GetLength(); i < len; i++) { auto* method = arr->GetElementPtrSize(i, target_ptr_size_); if (method != nullptr && !method->IsRuntimeMethod()) { auto* klass = method->GetDeclaringClass(); CHECK(klass == nullptr || IsImageClass(klass)) << PrettyClass(klass) << " should be an image class"; } } } // kBinArtMethodClean picked arbitrarily, just required to differentiate between ArtFields and // ArtMethods. pointer_arrays_.emplace(arr, kBinArtMethodClean); } void ImageWriter::AssignImageBinSlot(mirror::Object* object) { DCHECK(object != nullptr); size_t object_size = object->SizeOf(); // The magic happens here. We segregate objects into different bins based // on how likely they are to get dirty at runtime. // // Likely-to-dirty objects get packed together into the same bin so that // at runtime their page dirtiness ratio (how many dirty objects a page has) is // maximized. // // This means more pages will stay either clean or shared dirty (with zygote) and // the app will use less of its own (private) memory. Bin bin = kBinRegular; size_t current_offset = 0u; if (kBinObjects) { // // Changing the bin of an object is purely a memory-use tuning. // It has no change on runtime correctness. // // Memory analysis has determined that the following types of objects get dirtied // the most: // // * Dex cache arrays are stored in a special bin. The arrays for each dex cache have // a fixed layout which helps improve generated code (using PC-relative addressing), // so we pre-calculate their offsets separately in PrepareDexCacheArraySlots(). // Since these arrays are huge, most pages do not overlap other objects and it's not // really important where they are for the clean/dirty separation. Due to their // special PC-relative addressing, we arbitrarily keep them at the end. // * Class'es which are verified [their clinit runs only at runtime] // - classes in general [because their static fields get overwritten] // - initialized classes with all-final statics are unlikely to be ever dirty, // so bin them separately // * Art Methods that are: // - native [their native entry point is not looked up until runtime] // - have declaring classes that aren't initialized // [their interpreter/quick entry points are trampolines until the class // becomes initialized] // // We also assume the following objects get dirtied either never or extremely rarely: // * Strings (they are immutable) // * Art methods that aren't native and have initialized declared classes // // We assume that "regular" bin objects are highly unlikely to become dirtied, // so packing them together will not result in a noticeably tighter dirty-to-clean ratio. // if (object->IsClass()) { bin = kBinClassVerified; mirror::Class* klass = object->AsClass(); // Add non-embedded vtable to the pointer array table if there is one. auto* vtable = klass->GetVTable(); if (vtable != nullptr) { AddMethodPointerArray(vtable); } auto* iftable = klass->GetIfTable(); if (iftable != nullptr) { for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { if (iftable->GetMethodArrayCount(i) > 0) { AddMethodPointerArray(iftable->GetMethodArray(i)); } } } if (klass->GetStatus() == Class::kStatusInitialized) { bin = kBinClassInitialized; // If the class's static fields are all final, put it into a separate bin // since it's very likely it will stay clean. uint32_t num_static_fields = klass->NumStaticFields(); if (num_static_fields == 0) { bin = kBinClassInitializedFinalStatics; } else { // Maybe all the statics are final? bool all_final = true; for (uint32_t i = 0; i < num_static_fields; ++i) { ArtField* field = klass->GetStaticField(i); if (!field->IsFinal()) { all_final = false; break; } } if (all_final) { bin = kBinClassInitializedFinalStatics; } } } } else if (object->GetClass()->IsStringClass()) { bin = kBinString; // Strings are almost always immutable (except for object header). } // else bin = kBinRegular } size_t offset_delta = RoundUp(object_size, kObjectAlignment); // 64-bit alignment current_offset = bin_slot_sizes_[bin]; // How many bytes the current bin is at (aligned). // Move the current bin size up to accomodate the object we just assigned a bin slot. bin_slot_sizes_[bin] += offset_delta; BinSlot new_bin_slot(bin, current_offset); SetImageBinSlot(object, new_bin_slot); ++bin_slot_count_[bin]; // Grow the image closer to the end by the object we just assigned. image_end_ += offset_delta; } bool ImageWriter::WillMethodBeDirty(ArtMethod* m) const { if (m->IsNative()) { return true; } mirror::Class* declaring_class = m->GetDeclaringClass(); // Initialized is highly unlikely to dirty since there's no entry points to mutate. return declaring_class == nullptr || declaring_class->GetStatus() != Class::kStatusInitialized; } bool ImageWriter::IsImageBinSlotAssigned(mirror::Object* object) const { DCHECK(object != nullptr); // We always stash the bin slot into a lockword, in the 'forwarding address' state. // If it's in some other state, then we haven't yet assigned an image bin slot. if (object->GetLockWord(false).GetState() != LockWord::kForwardingAddress) { return false; } else if (kIsDebugBuild) { LockWord lock_word = object->GetLockWord(false); size_t offset = lock_word.ForwardingAddress(); BinSlot bin_slot(offset); DCHECK_LT(bin_slot.GetIndex(), bin_slot_sizes_[bin_slot.GetBin()]) << "bin slot offset should not exceed the size of that bin"; } return true; } ImageWriter::BinSlot ImageWriter::GetImageBinSlot(mirror::Object* object) const { DCHECK(object != nullptr); DCHECK(IsImageBinSlotAssigned(object)); LockWord lock_word = object->GetLockWord(false); size_t offset = lock_word.ForwardingAddress(); // TODO: ForwardingAddress should be uint32_t DCHECK_LE(offset, std::numeric_limits::max()); BinSlot bin_slot(static_cast(offset)); DCHECK_LT(bin_slot.GetIndex(), bin_slot_sizes_[bin_slot.GetBin()]); return bin_slot; } bool ImageWriter::AllocMemory() { const size_t length = RoundUp(image_objects_offset_begin_ + GetBinSizeSum() + intern_table_bytes_, kPageSize); std::string error_msg; image_.reset(MemMap::MapAnonymous("image writer image", nullptr, length, PROT_READ | PROT_WRITE, false, false, &error_msg)); if (UNLIKELY(image_.get() == nullptr)) { LOG(ERROR) << "Failed to allocate memory for image file generation: " << error_msg; return false; } // Create the image bitmap, only needs to cover mirror object section which is up to image_end_. CHECK_LE(image_end_, length); image_bitmap_.reset(gc::accounting::ContinuousSpaceBitmap::Create( "image bitmap", image_->Begin(), RoundUp(image_end_, kPageSize))); if (image_bitmap_.get() == nullptr) { LOG(ERROR) << "Failed to allocate memory for image bitmap"; return false; } return true; } class ComputeLazyFieldsForClassesVisitor : public ClassVisitor { public: bool Visit(Class* c) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { StackHandleScope<1> hs(Thread::Current()); mirror::Class::ComputeName(hs.NewHandle(c)); return true; } }; void ImageWriter::ComputeLazyFieldsForImageClasses() { ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); ComputeLazyFieldsForClassesVisitor visitor; class_linker->VisitClassesWithoutClassesLock(&visitor); } bool ImageWriter::IsImageClass(Class* klass) { if (klass == nullptr) { return false; } std::string temp; return compiler_driver_.IsImageClass(klass->GetDescriptor(&temp)); } class NonImageClassesVisitor : public ClassVisitor { public: explicit NonImageClassesVisitor(ImageWriter* image_writer) : image_writer_(image_writer) {} bool Visit(Class* klass) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { if (!image_writer_->IsImageClass(klass)) { std::string temp; non_image_classes_.insert(klass->GetDescriptor(&temp)); } return true; } std::set non_image_classes_; ImageWriter* const image_writer_; }; void ImageWriter::PruneNonImageClasses() { if (compiler_driver_.GetImageClasses() == nullptr) { return; } Runtime* runtime = Runtime::Current(); ClassLinker* class_linker = runtime->GetClassLinker(); Thread* self = Thread::Current(); // Make a list of classes we would like to prune. NonImageClassesVisitor visitor(this); class_linker->VisitClasses(&visitor); // Remove the undesired classes from the class roots. for (const std::string& it : visitor.non_image_classes_) { bool result = class_linker->RemoveClass(it.c_str(), nullptr); DCHECK(result); } // Clear references to removed classes from the DexCaches. ArtMethod* resolution_method = runtime->GetResolutionMethod(); ScopedAssertNoThreadSuspension sa(self, __FUNCTION__); ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); // For ClassInClassTable ReaderMutexLock mu2(self, *class_linker->DexLock()); for (jobject weak_root : class_linker->GetDexCaches()) { mirror::DexCache* dex_cache = down_cast(self->DecodeJObject(weak_root)); if (dex_cache == nullptr) { continue; } for (size_t i = 0; i < dex_cache->NumResolvedTypes(); i++) { Class* klass = dex_cache->GetResolvedType(i); if (klass != nullptr && !IsImageClass(klass)) { dex_cache->SetResolvedType(i, nullptr); } } ArtMethod** resolved_methods = dex_cache->GetResolvedMethods(); for (size_t i = 0, num = dex_cache->NumResolvedMethods(); i != num; ++i) { ArtMethod* method = mirror::DexCache::GetElementPtrSize(resolved_methods, i, target_ptr_size_); if (method != nullptr) { auto* declaring_class = method->GetDeclaringClass(); // Miranda methods may be held live by a class which was not an image class but have a // declaring class which is an image class. Set it to the resolution method to be safe and // prevent dangling pointers. if (method->IsMiranda() || !IsImageClass(declaring_class)) { mirror::DexCache::SetElementPtrSize(resolved_methods, i, resolution_method, target_ptr_size_); } else { // Check that the class is still in the classes table. DCHECK(class_linker->ClassInClassTable(declaring_class)) << "Class " << PrettyClass(declaring_class) << " not in class linker table"; } } } for (size_t i = 0; i < dex_cache->NumResolvedFields(); i++) { ArtField* field = dex_cache->GetResolvedField(i, target_ptr_size_); if (field != nullptr && !IsImageClass(field->GetDeclaringClass())) { dex_cache->SetResolvedField(i, nullptr, target_ptr_size_); } } // Clean the dex field. It might have been populated during the initialization phase, but // contains data only valid during a real run. dex_cache->SetFieldObject(mirror::DexCache::DexOffset(), nullptr); } // Drop the array class cache in the ClassLinker, as these are roots holding those classes live. class_linker->DropFindArrayClassCache(); } void ImageWriter::CheckNonImageClassesRemoved() { if (compiler_driver_.GetImageClasses() != nullptr) { gc::Heap* heap = Runtime::Current()->GetHeap(); heap->VisitObjects(CheckNonImageClassesRemovedCallback, this); } } void ImageWriter::CheckNonImageClassesRemovedCallback(Object* obj, void* arg) { ImageWriter* image_writer = reinterpret_cast(arg); if (obj->IsClass()) { Class* klass = obj->AsClass(); if (!image_writer->IsImageClass(klass)) { image_writer->DumpImageClasses(); std::string temp; CHECK(image_writer->IsImageClass(klass)) << klass->GetDescriptor(&temp) << " " << PrettyDescriptor(klass); } } } void ImageWriter::DumpImageClasses() { auto image_classes = compiler_driver_.GetImageClasses(); CHECK(image_classes != nullptr); for (const std::string& image_class : *image_classes) { LOG(INFO) << " " << image_class; } } void ImageWriter::CalculateObjectBinSlots(Object* obj) { DCHECK(obj != nullptr); // if it is a string, we want to intern it if its not interned. if (obj->GetClass()->IsStringClass()) { // we must be an interned string that was forward referenced and already assigned if (IsImageBinSlotAssigned(obj)) { DCHECK_EQ(obj, obj->AsString()->Intern()); return; } // InternImageString allows us to intern while holding the heap bitmap lock. This is safe since // we are guaranteed to not have GC during image writing. mirror::String* const interned = Runtime::Current()->GetInternTable()->InternStrongImageString( obj->AsString()); if (obj != interned) { if (!IsImageBinSlotAssigned(interned)) { // interned obj is after us, allocate its location early AssignImageBinSlot(interned); } // point those looking for this object to the interned version. SetImageBinSlot(obj, GetImageBinSlot(interned)); return; } // else (obj == interned), nothing to do but fall through to the normal case } AssignImageBinSlot(obj); } ObjectArray* ImageWriter::CreateImageRoots() const { Runtime* runtime = Runtime::Current(); ClassLinker* class_linker = runtime->GetClassLinker(); Thread* self = Thread::Current(); StackHandleScope<3> hs(self); Handle object_array_class(hs.NewHandle( class_linker->FindSystemClass(self, "[Ljava/lang/Object;"))); // build an Object[] of all the DexCaches used in the source_space_. // Since we can't hold the dex lock when allocating the dex_caches // ObjectArray, we lock the dex lock twice, first to get the number // of dex caches first and then lock it again to copy the dex // caches. We check that the number of dex caches does not change. size_t dex_cache_count; { ReaderMutexLock mu(self, *class_linker->DexLock()); dex_cache_count = class_linker->GetDexCacheCount(); } Handle> dex_caches( hs.NewHandle(ObjectArray::Alloc(self, object_array_class.Get(), dex_cache_count))); CHECK(dex_caches.Get() != nullptr) << "Failed to allocate a dex cache array."; { ReaderMutexLock mu(self, *class_linker->DexLock()); CHECK_EQ(dex_cache_count, class_linker->GetDexCacheCount()) << "The number of dex caches changed."; size_t i = 0; for (jobject weak_root : class_linker->GetDexCaches()) { mirror::DexCache* dex_cache = down_cast(self->DecodeJObject(weak_root)); dex_caches->Set(i, dex_cache); ++i; } } // build an Object[] of the roots needed to restore the runtime auto image_roots(hs.NewHandle( ObjectArray::Alloc(self, object_array_class.Get(), ImageHeader::kImageRootsMax))); image_roots->Set(ImageHeader::kDexCaches, dex_caches.Get()); image_roots->Set(ImageHeader::kClassRoots, class_linker->GetClassRoots()); for (int i = 0; i < ImageHeader::kImageRootsMax; i++) { CHECK(image_roots->Get(i) != nullptr); } return image_roots.Get(); } // Walk instance fields of the given Class. Separate function to allow recursion on the super // class. void ImageWriter::WalkInstanceFields(mirror::Object* obj, mirror::Class* klass) { // Visit fields of parent classes first. StackHandleScope<1> hs(Thread::Current()); Handle h_class(hs.NewHandle(klass)); mirror::Class* super = h_class->GetSuperClass(); if (super != nullptr) { WalkInstanceFields(obj, super); } // size_t num_reference_fields = h_class->NumReferenceInstanceFields(); MemberOffset field_offset = h_class->GetFirstReferenceInstanceFieldOffset(); for (size_t i = 0; i < num_reference_fields; ++i) { mirror::Object* value = obj->GetFieldObject(field_offset); if (value != nullptr) { WalkFieldsInOrder(value); } field_offset = MemberOffset(field_offset.Uint32Value() + sizeof(mirror::HeapReference)); } } // For an unvisited object, visit it then all its children found via fields. void ImageWriter::WalkFieldsInOrder(mirror::Object* obj) { // Use our own visitor routine (instead of GC visitor) to get better locality between // an object and its fields if (!IsImageBinSlotAssigned(obj)) { // Walk instance fields of all objects StackHandleScope<2> hs(Thread::Current()); Handle h_obj(hs.NewHandle(obj)); Handle klass(hs.NewHandle(obj->GetClass())); // visit the object itself. CalculateObjectBinSlots(h_obj.Get()); WalkInstanceFields(h_obj.Get(), klass.Get()); // Walk static fields of a Class. if (h_obj->IsClass()) { size_t num_reference_static_fields = klass->NumReferenceStaticFields(); MemberOffset field_offset = klass->GetFirstReferenceStaticFieldOffset(target_ptr_size_); for (size_t i = 0; i < num_reference_static_fields; ++i) { mirror::Object* value = h_obj->GetFieldObject(field_offset); if (value != nullptr) { WalkFieldsInOrder(value); } field_offset = MemberOffset(field_offset.Uint32Value() + sizeof(mirror::HeapReference)); } // Visit and assign offsets for fields and field arrays. auto* as_klass = h_obj->AsClass(); LengthPrefixedArray* fields[] = { as_klass->GetSFieldsPtr(), as_klass->GetIFieldsPtr(), }; for (LengthPrefixedArray* cur_fields : fields) { // Total array length including header. if (cur_fields != nullptr) { const size_t header_size = LengthPrefixedArray::ComputeSize(0); // Forward the entire array at once. auto it = native_object_relocations_.find(cur_fields); CHECK(it == native_object_relocations_.end()) << "Field array " << cur_fields << " already forwarded"; size_t& offset = bin_slot_sizes_[kBinArtField]; native_object_relocations_.emplace( cur_fields, NativeObjectRelocation { offset, kNativeObjectRelocationTypeArtFieldArray }); offset += header_size; // Forward individual fields so that we can quickly find where they belong. for (size_t i = 0, count = cur_fields->Length(); i < count; ++i) { // Need to forward arrays separate of fields. ArtField* field = &cur_fields->At(i); auto it2 = native_object_relocations_.find(field); CHECK(it2 == native_object_relocations_.end()) << "Field at index=" << i << " already assigned " << PrettyField(field) << " static=" << field->IsStatic(); native_object_relocations_.emplace( field, NativeObjectRelocation {offset, kNativeObjectRelocationTypeArtField }); offset += sizeof(ArtField); } } } // Visit and assign offsets for methods. LengthPrefixedArray* method_arrays[] = { as_klass->GetDirectMethodsPtr(), as_klass->GetVirtualMethodsPtr(), }; for (LengthPrefixedArray* array : method_arrays) { if (array == nullptr) { continue; } bool any_dirty = false; size_t count = 0; const size_t method_alignment = ArtMethod::Alignment(target_ptr_size_); const size_t method_size = ArtMethod::Size(target_ptr_size_); auto iteration_range = MakeIterationRangeFromLengthPrefixedArray(array, method_size, method_alignment); for (auto& m : iteration_range) { any_dirty = any_dirty || WillMethodBeDirty(&m); ++count; } NativeObjectRelocationType type = any_dirty ? kNativeObjectRelocationTypeArtMethodDirty : kNativeObjectRelocationTypeArtMethodClean; Bin bin_type = BinTypeForNativeRelocationType(type); // Forward the entire array at once, but header first. const size_t header_size = LengthPrefixedArray::ComputeSize(0, method_size, method_alignment); auto it = native_object_relocations_.find(array); CHECK(it == native_object_relocations_.end()) << "Method array " << array << " already forwarded"; size_t& offset = bin_slot_sizes_[bin_type]; native_object_relocations_.emplace(array, NativeObjectRelocation { offset, any_dirty ? kNativeObjectRelocationTypeArtMethodArrayDirty : kNativeObjectRelocationTypeArtMethodArrayClean }); offset += header_size; for (auto& m : iteration_range) { AssignMethodOffset(&m, type); } (any_dirty ? dirty_methods_ : clean_methods_) += count; } } else if (h_obj->IsObjectArray()) { // Walk elements of an object array. int32_t length = h_obj->AsObjectArray()->GetLength(); for (int32_t i = 0; i < length; i++) { mirror::ObjectArray* obj_array = h_obj->AsObjectArray(); mirror::Object* value = obj_array->Get(i); if (value != nullptr) { WalkFieldsInOrder(value); } } } } } void ImageWriter::AssignMethodOffset(ArtMethod* method, NativeObjectRelocationType type) { auto it = native_object_relocations_.find(method); CHECK(it == native_object_relocations_.end()) << "Method " << method << " already assigned " << PrettyMethod(method); size_t& offset = bin_slot_sizes_[BinTypeForNativeRelocationType(type)]; native_object_relocations_.emplace(method, NativeObjectRelocation { offset, type }); offset += ArtMethod::Size(target_ptr_size_); } void ImageWriter::WalkFieldsCallback(mirror::Object* obj, void* arg) { ImageWriter* writer = reinterpret_cast(arg); DCHECK(writer != nullptr); writer->WalkFieldsInOrder(obj); } void ImageWriter::UnbinObjectsIntoOffsetCallback(mirror::Object* obj, void* arg) { ImageWriter* writer = reinterpret_cast(arg); DCHECK(writer != nullptr); writer->UnbinObjectsIntoOffset(obj); } void ImageWriter::UnbinObjectsIntoOffset(mirror::Object* obj) { CHECK(obj != nullptr); // We know the bin slot, and the total bin sizes for all objects by now, // so calculate the object's final image offset. DCHECK(IsImageBinSlotAssigned(obj)); BinSlot bin_slot = GetImageBinSlot(obj); // Change the lockword from a bin slot into an offset AssignImageOffset(obj, bin_slot); } void ImageWriter::CalculateNewObjectOffsets() { Thread* const self = Thread::Current(); StackHandleScope<1> hs(self); Handle> image_roots(hs.NewHandle(CreateImageRoots())); auto* runtime = Runtime::Current(); auto* heap = runtime->GetHeap(); DCHECK_EQ(0U, image_end_); // Leave space for the header, but do not write it yet, we need to // know where image_roots is going to end up image_end_ += RoundUp(sizeof(ImageHeader), kObjectAlignment); // 64-bit-alignment image_objects_offset_begin_ = image_end_; // Clear any pre-existing monitors which may have been in the monitor words, assign bin slots. heap->VisitObjects(WalkFieldsCallback, this); // Write the image runtime methods. image_methods_[ImageHeader::kResolutionMethod] = runtime->GetResolutionMethod(); image_methods_[ImageHeader::kImtConflictMethod] = runtime->GetImtConflictMethod(); image_methods_[ImageHeader::kImtUnimplementedMethod] = runtime->GetImtUnimplementedMethod(); image_methods_[ImageHeader::kCalleeSaveMethod] = runtime->GetCalleeSaveMethod(Runtime::kSaveAll); image_methods_[ImageHeader::kRefsOnlySaveMethod] = runtime->GetCalleeSaveMethod(Runtime::kRefsOnly); image_methods_[ImageHeader::kRefsAndArgsSaveMethod] = runtime->GetCalleeSaveMethod(Runtime::kRefsAndArgs); // Add room for fake length prefixed array. const auto image_method_type = kNativeObjectRelocationTypeArtMethodArrayClean; auto it = native_object_relocations_.find(&image_method_array_); CHECK(it == native_object_relocations_.end()); size_t& offset = bin_slot_sizes_[BinTypeForNativeRelocationType(image_method_type)]; native_object_relocations_.emplace(&image_method_array_, NativeObjectRelocation { offset, image_method_type }); size_t method_alignment = ArtMethod::Alignment(target_ptr_size_); const size_t array_size = LengthPrefixedArray::ComputeSize( 0, ArtMethod::Size(target_ptr_size_), method_alignment); CHECK_ALIGNED_PARAM(array_size, method_alignment); offset += array_size; for (auto* m : image_methods_) { CHECK(m != nullptr); CHECK(m->IsRuntimeMethod()); AssignMethodOffset(m, kNativeObjectRelocationTypeArtMethodClean); } // Calculate size of the dex cache arrays slot and prepare offsets. PrepareDexCacheArraySlots(); // Calculate bin slot offsets. size_t bin_offset = image_objects_offset_begin_; for (size_t i = 0; i != kBinSize; ++i) { bin_slot_offsets_[i] = bin_offset; bin_offset += bin_slot_sizes_[i]; if (i == kBinArtField) { static_assert(kBinArtField + 1 == kBinArtMethodClean, "Methods follow fields."); static_assert(alignof(ArtField) == 4u, "ArtField alignment is 4."); DCHECK_ALIGNED(bin_offset, 4u); DCHECK(method_alignment == 4u || method_alignment == 8u); bin_offset = RoundUp(bin_offset, method_alignment); } } // NOTE: There may be additional padding between the bin slots and the intern table. DCHECK_EQ(image_end_, GetBinSizeSum(kBinMirrorCount) + image_objects_offset_begin_); // Transform each object's bin slot into an offset which will be used to do the final copy. heap->VisitObjects(UnbinObjectsIntoOffsetCallback, this); DCHECK_EQ(image_end_, GetBinSizeSum(kBinMirrorCount) + image_objects_offset_begin_); image_roots_address_ = PointerToLowMemUInt32(GetImageAddress(image_roots.Get())); // Update the native relocations by adding their bin sums. for (auto& pair : native_object_relocations_) { NativeObjectRelocation& relocation = pair.second; Bin bin_type = BinTypeForNativeRelocationType(relocation.type); relocation.offset += bin_slot_offsets_[bin_type]; } // Calculate how big the intern table will be after being serialized. auto* const intern_table = Runtime::Current()->GetInternTable(); CHECK_EQ(intern_table->WeakSize(), 0u) << " should have strong interned all the strings"; intern_table_bytes_ = intern_table->WriteToMemory(nullptr); // Note that image_end_ is left at end of used mirror object section. } void ImageWriter::CreateHeader(size_t oat_loaded_size, size_t oat_data_offset) { CHECK_NE(0U, oat_loaded_size); const uint8_t* oat_file_begin = GetOatFileBegin(); const uint8_t* oat_file_end = oat_file_begin + oat_loaded_size; oat_data_begin_ = oat_file_begin + oat_data_offset; const uint8_t* oat_data_end = oat_data_begin_ + oat_file_->Size(); // Create the image sections. ImageSection sections[ImageHeader::kSectionCount]; // Objects section auto* objects_section = §ions[ImageHeader::kSectionObjects]; *objects_section = ImageSection(0u, image_end_); size_t cur_pos = objects_section->End(); // Add field section. auto* field_section = §ions[ImageHeader::kSectionArtFields]; *field_section = ImageSection(cur_pos, bin_slot_sizes_[kBinArtField]); CHECK_EQ(bin_slot_offsets_[kBinArtField], field_section->Offset()); cur_pos = field_section->End(); // Round up to the alignment the required by the method section. cur_pos = RoundUp(cur_pos, ArtMethod::Alignment(target_ptr_size_)); // Add method section. auto* methods_section = §ions[ImageHeader::kSectionArtMethods]; *methods_section = ImageSection(cur_pos, bin_slot_sizes_[kBinArtMethodClean] + bin_slot_sizes_[kBinArtMethodDirty]); CHECK_EQ(bin_slot_offsets_[kBinArtMethodClean], methods_section->Offset()); cur_pos = methods_section->End(); // Add dex cache arrays section. auto* dex_cache_arrays_section = §ions[ImageHeader::kSectionDexCacheArrays]; *dex_cache_arrays_section = ImageSection(cur_pos, bin_slot_sizes_[kBinDexCacheArray]); CHECK_EQ(bin_slot_offsets_[kBinDexCacheArray], dex_cache_arrays_section->Offset()); cur_pos = dex_cache_arrays_section->End(); // Round up to the alignment the string table expects. See HashSet::WriteToMemory. cur_pos = RoundUp(cur_pos, sizeof(uint64_t)); // Calculate the size of the interned strings. auto* interned_strings_section = §ions[ImageHeader::kSectionInternedStrings]; *interned_strings_section = ImageSection(cur_pos, intern_table_bytes_); cur_pos = interned_strings_section->End(); // Finally bitmap section. const size_t bitmap_bytes = image_bitmap_->Size(); auto* bitmap_section = §ions[ImageHeader::kSectionImageBitmap]; *bitmap_section = ImageSection(RoundUp(cur_pos, kPageSize), RoundUp(bitmap_bytes, kPageSize)); cur_pos = bitmap_section->End(); if (kIsDebugBuild) { size_t idx = 0; for (const ImageSection& section : sections) { LOG(INFO) << static_cast(idx) << " " << section; ++idx; } LOG(INFO) << "Methods: clean=" << clean_methods_ << " dirty=" << dirty_methods_; } const size_t image_end = static_cast(interned_strings_section->End()); CHECK_EQ(AlignUp(image_begin_ + image_end, kPageSize), oat_file_begin) << "Oat file should be right after the image."; // Create the header. new (image_->Begin()) ImageHeader( PointerToLowMemUInt32(image_begin_), image_end, sections, image_roots_address_, oat_file_->GetOatHeader().GetChecksum(), PointerToLowMemUInt32(oat_file_begin), PointerToLowMemUInt32(oat_data_begin_), PointerToLowMemUInt32(oat_data_end), PointerToLowMemUInt32(oat_file_end), target_ptr_size_, compile_pic_); } ArtMethod* ImageWriter::GetImageMethodAddress(ArtMethod* method) { auto it = native_object_relocations_.find(method); CHECK(it != native_object_relocations_.end()) << PrettyMethod(method) << " @ " << method; CHECK_GE(it->second.offset, image_end_) << "ArtMethods should be after Objects"; return reinterpret_cast(image_begin_ + it->second.offset); } class FixupRootVisitor : public RootVisitor { public: explicit FixupRootVisitor(ImageWriter* image_writer) : image_writer_(image_writer) { } void VisitRoots(mirror::Object*** roots, size_t count, const RootInfo& info ATTRIBUTE_UNUSED) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { for (size_t i = 0; i < count; ++i) { *roots[i] = ImageAddress(*roots[i]); } } void VisitRoots(mirror::CompressedReference** roots, size_t count, const RootInfo& info ATTRIBUTE_UNUSED) OVERRIDE SHARED_REQUIRES(Locks::mutator_lock_) { for (size_t i = 0; i < count; ++i) { roots[i]->Assign(ImageAddress(roots[i]->AsMirrorPtr())); } } private: ImageWriter* const image_writer_; mirror::Object* ImageAddress(mirror::Object* obj) SHARED_REQUIRES(Locks::mutator_lock_) { const size_t offset = image_writer_->GetImageOffset(obj); auto* const dest = reinterpret_cast(image_writer_->image_begin_ + offset); VLOG(compiler) << "Update root from " << obj << " to " << dest; return dest; } }; void ImageWriter::CopyAndFixupNativeData() { // Copy ArtFields and methods to their locations and update the array for convenience. for (auto& pair : native_object_relocations_) { NativeObjectRelocation& relocation = pair.second; auto* dest = image_->Begin() + relocation.offset; DCHECK_GE(dest, image_->Begin() + image_end_); switch (relocation.type) { case kNativeObjectRelocationTypeArtField: { memcpy(dest, pair.first, sizeof(ArtField)); reinterpret_cast(dest)->SetDeclaringClass( GetImageAddress(reinterpret_cast(pair.first)->GetDeclaringClass())); break; } case kNativeObjectRelocationTypeArtMethodClean: case kNativeObjectRelocationTypeArtMethodDirty: { CopyAndFixupMethod(reinterpret_cast(pair.first), reinterpret_cast(dest)); break; } // For arrays, copy just the header since the elements will get copied by their corresponding // relocations. case kNativeObjectRelocationTypeArtFieldArray: { memcpy(dest, pair.first, LengthPrefixedArray::ComputeSize(0)); break; } case kNativeObjectRelocationTypeArtMethodArrayClean: case kNativeObjectRelocationTypeArtMethodArrayDirty: { memcpy(dest, pair.first, LengthPrefixedArray::ComputeSize( 0, ArtMethod::Size(target_ptr_size_), ArtMethod::Alignment(target_ptr_size_))); break; case kNativeObjectRelocationTypeDexCacheArray: // Nothing to copy here, everything is done in FixupDexCache(). break; } } } // Fixup the image method roots. auto* image_header = reinterpret_cast(image_->Begin()); const ImageSection& methods_section = image_header->GetMethodsSection(); for (size_t i = 0; i < ImageHeader::kImageMethodsCount; ++i) { auto* m = image_methods_[i]; CHECK(m != nullptr); auto it = native_object_relocations_.find(m); CHECK(it != native_object_relocations_.end()) << "No fowarding for " << PrettyMethod(m); NativeObjectRelocation& relocation = it->second; CHECK(methods_section.Contains(relocation.offset)) << relocation.offset << " not in " << methods_section; CHECK(relocation.IsArtMethodRelocation()) << relocation.type; auto* dest = reinterpret_cast(image_begin_ + it->second.offset); image_header->SetImageMethod(static_cast(i), dest); } // Write the intern table into the image. const ImageSection& intern_table_section = image_header->GetImageSection( ImageHeader::kSectionInternedStrings); InternTable* const intern_table = Runtime::Current()->GetInternTable(); uint8_t* const memory_ptr = image_->Begin() + intern_table_section.Offset(); const size_t intern_table_bytes = intern_table->WriteToMemory(memory_ptr); // Fixup the pointers in the newly written intern table to contain image addresses. InternTable temp_table; // Note that we require that ReadFromMemory does not make an internal copy of the elements so that // the VisitRoots() will update the memory directly rather than the copies. // This also relies on visit roots not doing any verification which could fail after we update // the roots to be the image addresses. temp_table.ReadFromMemory(memory_ptr); CHECK_EQ(temp_table.Size(), intern_table->Size()); FixupRootVisitor visitor(this); temp_table.VisitRoots(&visitor, kVisitRootFlagAllRoots); CHECK_EQ(intern_table_bytes, intern_table_bytes_); } void ImageWriter::CopyAndFixupObjects() { gc::Heap* heap = Runtime::Current()->GetHeap(); heap->VisitObjects(CopyAndFixupObjectsCallback, this); // Fix up the object previously had hash codes. for (const auto& hash_pair : saved_hashcode_map_) { Object* obj = hash_pair.first; DCHECK_EQ(obj->GetLockWord(false).ReadBarrierState(), 0U); obj->SetLockWord(LockWord::FromHashCode(hash_pair.second, 0U), false); } saved_hashcode_map_.clear(); } void ImageWriter::CopyAndFixupObjectsCallback(Object* obj, void* arg) { DCHECK(obj != nullptr); DCHECK(arg != nullptr); reinterpret_cast(arg)->CopyAndFixupObject(obj); } void ImageWriter::FixupPointerArray(mirror::Object* dst, mirror::PointerArray* arr, mirror::Class* klass, Bin array_type) { CHECK(klass->IsArrayClass()); CHECK(arr->IsIntArray() || arr->IsLongArray()) << PrettyClass(klass) << " " << arr; // Fixup int and long pointers for the ArtMethod or ArtField arrays. const size_t num_elements = arr->GetLength(); dst->SetClass(GetImageAddress(arr->GetClass())); auto* dest_array = down_cast(dst); for (size_t i = 0, count = num_elements; i < count; ++i) { auto* elem = arr->GetElementPtrSize(i, target_ptr_size_); if (elem != nullptr) { auto it = native_object_relocations_.find(elem); if (UNLIKELY(it == native_object_relocations_.end())) { if (it->second.IsArtMethodRelocation()) { auto* method = reinterpret_cast(elem); LOG(FATAL) << "No relocation entry for ArtMethod " << PrettyMethod(method) << " @ " << method << " idx=" << i << "/" << num_elements << " with declaring class " << PrettyClass(method->GetDeclaringClass()); } else { CHECK_EQ(array_type, kBinArtField); auto* field = reinterpret_cast(elem); LOG(FATAL) << "No relocation entry for ArtField " << PrettyField(field) << " @ " << field << " idx=" << i << "/" << num_elements << " with declaring class " << PrettyClass(field->GetDeclaringClass()); } UNREACHABLE(); } else { elem = image_begin_ + it->second.offset; } } dest_array->SetElementPtrSize(i, elem, target_ptr_size_); } } void ImageWriter::CopyAndFixupObject(Object* obj) { size_t offset = GetImageOffset(obj); auto* dst = reinterpret_cast(image_->Begin() + offset); DCHECK_LT(offset, image_end_); const auto* src = reinterpret_cast(obj); image_bitmap_->Set(dst); // Mark the obj as live. const size_t n = obj->SizeOf(); DCHECK_LE(offset + n, image_->Size()); memcpy(dst, src, n); // Write in a hash code of objects which have inflated monitors or a hash code in their monitor // word. const auto it = saved_hashcode_map_.find(obj); dst->SetLockWord(it != saved_hashcode_map_.end() ? LockWord::FromHashCode(it->second, 0u) : LockWord::Default(), false); FixupObject(obj, dst); } // Rewrite all the references in the copied object to point to their image address equivalent class FixupVisitor { public: FixupVisitor(ImageWriter* image_writer, Object* copy) : image_writer_(image_writer), copy_(copy) { } // Ignore class roots since we don't have a way to map them to the destination. These are handled // with other logic. void VisitRootIfNonNull(mirror::CompressedReference* root ATTRIBUTE_UNUSED) const {} void VisitRoot(mirror::CompressedReference* root ATTRIBUTE_UNUSED) const {} void operator()(Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { Object* ref = obj->GetFieldObject(offset); // Use SetFieldObjectWithoutWriteBarrier to avoid card marking since we are writing to the // image. copy_->SetFieldObjectWithoutWriteBarrier( offset, image_writer_->GetImageAddress(ref)); } // java.lang.ref.Reference visitor. void operator()(mirror::Class* klass ATTRIBUTE_UNUSED, mirror::Reference* ref) const SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(Locks::heap_bitmap_lock_) { copy_->SetFieldObjectWithoutWriteBarrier( mirror::Reference::ReferentOffset(), image_writer_->GetImageAddress(ref->GetReferent())); } protected: ImageWriter* const image_writer_; mirror::Object* const copy_; }; class FixupClassVisitor FINAL : public FixupVisitor { public: FixupClassVisitor(ImageWriter* image_writer, Object* copy) : FixupVisitor(image_writer, copy) { } void operator()(Object* obj, MemberOffset offset, bool is_static ATTRIBUTE_UNUSED) const REQUIRES(Locks::mutator_lock_, Locks::heap_bitmap_lock_) { DCHECK(obj->IsClass()); FixupVisitor::operator()(obj, offset, /*is_static*/false); } void operator()(mirror::Class* klass ATTRIBUTE_UNUSED, mirror::Reference* ref ATTRIBUTE_UNUSED) const SHARED_REQUIRES(Locks::mutator_lock_) REQUIRES(Locks::heap_bitmap_lock_) { LOG(FATAL) << "Reference not expected here."; } }; uintptr_t ImageWriter::NativeOffsetInImage(void* obj) { DCHECK(obj != nullptr); auto it = native_object_relocations_.find(obj); CHECK(it != native_object_relocations_.end()) << obj; const NativeObjectRelocation& relocation = it->second; return relocation.offset; } template T* ImageWriter::NativeLocationInImage(T* obj) { if (obj == nullptr) { return nullptr; } return reinterpret_cast(image_begin_ + NativeOffsetInImage(obj)); } void ImageWriter::FixupClass(mirror::Class* orig, mirror::Class* copy) { // Update the field arrays. copy->SetSFieldsPtrUnchecked(NativeLocationInImage(orig->GetSFieldsPtr())); copy->SetIFieldsPtrUnchecked(NativeLocationInImage(orig->GetIFieldsPtr())); // Update direct and virtual method arrays. copy->SetDirectMethodsPtrUnchecked(NativeLocationInImage(orig->GetDirectMethodsPtr())); copy->SetVirtualMethodsPtr(NativeLocationInImage(orig->GetVirtualMethodsPtr())); // Update dex cache strings. copy->SetDexCacheStrings(NativeLocationInImage(orig->GetDexCacheStrings())); // Fix up embedded tables. if (orig->ShouldHaveEmbeddedImtAndVTable()) { for (int32_t i = 0; i < orig->GetEmbeddedVTableLength(); ++i) { auto it = native_object_relocations_.find(orig->GetEmbeddedVTableEntry(i, target_ptr_size_)); CHECK(it != native_object_relocations_.end()) << PrettyClass(orig); copy->SetEmbeddedVTableEntryUnchecked( i, reinterpret_cast(image_begin_ + it->second.offset), target_ptr_size_); } for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { auto it = native_object_relocations_.find(orig->GetEmbeddedImTableEntry(i, target_ptr_size_)); CHECK(it != native_object_relocations_.end()) << PrettyClass(orig); copy->SetEmbeddedImTableEntry( i, reinterpret_cast(image_begin_ + it->second.offset), target_ptr_size_); } } FixupClassVisitor visitor(this, copy); static_cast(orig)->VisitReferences(visitor, visitor); } void ImageWriter::FixupObject(Object* orig, Object* copy) { DCHECK(orig != nullptr); DCHECK(copy != nullptr); if (kUseBakerOrBrooksReadBarrier) { orig->AssertReadBarrierPointer(); if (kUseBrooksReadBarrier) { // Note the address 'copy' isn't the same as the image address of 'orig'. copy->SetReadBarrierPointer(GetImageAddress(orig)); DCHECK_EQ(copy->GetReadBarrierPointer(), GetImageAddress(orig)); } } auto* klass = orig->GetClass(); if (klass->IsIntArrayClass() || klass->IsLongArrayClass()) { // Is this a native pointer array? auto it = pointer_arrays_.find(down_cast(orig)); if (it != pointer_arrays_.end()) { // Should only need to fixup every pointer array exactly once. FixupPointerArray(copy, down_cast(orig), klass, it->second); pointer_arrays_.erase(it); return; } } if (orig->IsClass()) { FixupClass(orig->AsClass(), down_cast(copy)); } else { if (klass == mirror::Method::StaticClass() || klass == mirror::Constructor::StaticClass()) { // Need to go update the ArtMethod. auto* dest = down_cast(copy); auto* src = down_cast(orig); ArtMethod* src_method = src->GetArtMethod(); auto it = native_object_relocations_.find(src_method); CHECK(it != native_object_relocations_.end()) << "Missing relocation for AbstractMethod.artMethod " << PrettyMethod(src_method); dest->SetArtMethod( reinterpret_cast(image_begin_ + it->second.offset)); } else if (!klass->IsArrayClass()) { ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); if (klass == class_linker->GetClassRoot(ClassLinker::kJavaLangDexCache)) { FixupDexCache(down_cast(orig), down_cast(copy)); } else if (klass->IsSubClass(down_cast( class_linker->GetClassRoot(ClassLinker::kJavaLangClassLoader)))) { // If src is a ClassLoader, set the class table to null so that it gets recreated by the // ClassLoader. down_cast(copy)->SetClassTable(nullptr); } } FixupVisitor visitor(this, copy); orig->VisitReferences(visitor, visitor); } } void ImageWriter::FixupDexCache(mirror::DexCache* orig_dex_cache, mirror::DexCache* copy_dex_cache) { // Though the DexCache array fields are usually treated as native pointers, we set the full // 64-bit values here, clearing the top 32 bits for 32-bit targets. The zero-extension is // done by casting to the unsigned type uintptr_t before casting to int64_t, i.e. // static_cast(reinterpret_cast(image_begin_ + offset))). GcRoot* orig_strings = orig_dex_cache->GetStrings(); if (orig_strings != nullptr) { uintptr_t copy_strings_offset = NativeOffsetInImage(orig_strings); copy_dex_cache->SetField64( mirror::DexCache::StringsOffset(), static_cast(reinterpret_cast(image_begin_ + copy_strings_offset))); GcRoot* copy_strings = reinterpret_cast*>(image_->Begin() + copy_strings_offset); for (size_t i = 0, num = orig_dex_cache->NumStrings(); i != num; ++i) { copy_strings[i] = GcRoot(GetImageAddress(orig_strings[i].Read())); } } GcRoot* orig_types = orig_dex_cache->GetResolvedTypes(); if (orig_types != nullptr) { uintptr_t copy_types_offset = NativeOffsetInImage(orig_types); copy_dex_cache->SetField64( mirror::DexCache::ResolvedTypesOffset(), static_cast(reinterpret_cast(image_begin_ + copy_types_offset))); GcRoot* copy_types = reinterpret_cast*>(image_->Begin() + copy_types_offset); for (size_t i = 0, num = orig_dex_cache->NumResolvedTypes(); i != num; ++i) { copy_types[i] = GcRoot(GetImageAddress(orig_types[i].Read())); } } ArtMethod** orig_methods = orig_dex_cache->GetResolvedMethods(); if (orig_methods != nullptr) { uintptr_t copy_methods_offset = NativeOffsetInImage(orig_methods); copy_dex_cache->SetField64( mirror::DexCache::ResolvedMethodsOffset(), static_cast(reinterpret_cast(image_begin_ + copy_methods_offset))); ArtMethod** copy_methods = reinterpret_cast(image_->Begin() + copy_methods_offset); for (size_t i = 0, num = orig_dex_cache->NumResolvedMethods(); i != num; ++i) { ArtMethod* orig = mirror::DexCache::GetElementPtrSize(orig_methods, i, target_ptr_size_); ArtMethod* copy = NativeLocationInImage(orig); mirror::DexCache::SetElementPtrSize(copy_methods, i, copy, target_ptr_size_); } } ArtField** orig_fields = orig_dex_cache->GetResolvedFields(); if (orig_fields != nullptr) { uintptr_t copy_fields_offset = NativeOffsetInImage(orig_fields); copy_dex_cache->SetField64( mirror::DexCache::ResolvedFieldsOffset(), static_cast(reinterpret_cast(image_begin_ + copy_fields_offset))); ArtField** copy_fields = reinterpret_cast(image_->Begin() + copy_fields_offset); for (size_t i = 0, num = orig_dex_cache->NumResolvedFields(); i != num; ++i) { ArtField* orig = mirror::DexCache::GetElementPtrSize(orig_fields, i, target_ptr_size_); ArtField* copy = NativeLocationInImage(orig); mirror::DexCache::SetElementPtrSize(copy_fields, i, copy, target_ptr_size_); } } } const uint8_t* ImageWriter::GetQuickCode(ArtMethod* method, bool* quick_is_interpreted) { DCHECK(!method->IsResolutionMethod() && !method->IsImtConflictMethod() && !method->IsImtUnimplementedMethod() && !method->IsAbstract()) << PrettyMethod(method); // Use original code if it exists. Otherwise, set the code pointer to the resolution // trampoline. // Quick entrypoint: uint32_t quick_oat_code_offset = PointerToLowMemUInt32( method->GetEntryPointFromQuickCompiledCodePtrSize(target_ptr_size_)); const uint8_t* quick_code = GetOatAddress(quick_oat_code_offset); *quick_is_interpreted = false; if (quick_code != nullptr && (!method->IsStatic() || method->IsConstructor() || method->GetDeclaringClass()->IsInitialized())) { // We have code for a non-static or initialized method, just use the code. DCHECK_GE(quick_code, oat_data_begin_); } else if (quick_code == nullptr && method->IsNative() && (!method->IsStatic() || method->GetDeclaringClass()->IsInitialized())) { // Non-static or initialized native method missing compiled code, use generic JNI version. quick_code = GetOatAddress(quick_generic_jni_trampoline_offset_); DCHECK_GE(quick_code, oat_data_begin_); } else if (quick_code == nullptr && !method->IsNative()) { // We don't have code at all for a non-native method, use the interpreter. quick_code = GetOatAddress(quick_to_interpreter_bridge_offset_); *quick_is_interpreted = true; DCHECK_GE(quick_code, oat_data_begin_); } else { CHECK(!method->GetDeclaringClass()->IsInitialized()); // We have code for a static method, but need to go through the resolution stub for class // initialization. quick_code = GetOatAddress(quick_resolution_trampoline_offset_); DCHECK_GE(quick_code, oat_data_begin_); } return quick_code; } const uint8_t* ImageWriter::GetQuickEntryPoint(ArtMethod* method) { // Calculate the quick entry point following the same logic as FixupMethod() below. // The resolution method has a special trampoline to call. Runtime* runtime = Runtime::Current(); if (UNLIKELY(method == runtime->GetResolutionMethod())) { return GetOatAddress(quick_resolution_trampoline_offset_); } else if (UNLIKELY(method == runtime->GetImtConflictMethod() || method == runtime->GetImtUnimplementedMethod())) { return GetOatAddress(quick_imt_conflict_trampoline_offset_); } else { // We assume all methods have code. If they don't currently then we set them to the use the // resolution trampoline. Abstract methods never have code and so we need to make sure their // use results in an AbstractMethodError. We use the interpreter to achieve this. if (UNLIKELY(method->IsAbstract())) { return GetOatAddress(quick_to_interpreter_bridge_offset_); } else { bool quick_is_interpreted; return GetQuickCode(method, &quick_is_interpreted); } } } void ImageWriter::CopyAndFixupMethod(ArtMethod* orig, ArtMethod* copy) { memcpy(copy, orig, ArtMethod::Size(target_ptr_size_)); copy->SetDeclaringClass(GetImageAddress(orig->GetDeclaringClassUnchecked())); ArtMethod** orig_resolved_methods = orig->GetDexCacheResolvedMethods(target_ptr_size_); copy->SetDexCacheResolvedMethods(NativeLocationInImage(orig_resolved_methods), target_ptr_size_); GcRoot* orig_resolved_types = orig->GetDexCacheResolvedTypes(target_ptr_size_); copy->SetDexCacheResolvedTypes(NativeLocationInImage(orig_resolved_types), target_ptr_size_); // OatWriter replaces the code_ with an offset value. Here we re-adjust to a pointer relative to // oat_begin_ // The resolution method has a special trampoline to call. Runtime* runtime = Runtime::Current(); if (UNLIKELY(orig == runtime->GetResolutionMethod())) { copy->SetEntryPointFromQuickCompiledCodePtrSize( GetOatAddress(quick_resolution_trampoline_offset_), target_ptr_size_); } else if (UNLIKELY(orig == runtime->GetImtConflictMethod() || orig == runtime->GetImtUnimplementedMethod())) { copy->SetEntryPointFromQuickCompiledCodePtrSize( GetOatAddress(quick_imt_conflict_trampoline_offset_), target_ptr_size_); } else if (UNLIKELY(orig->IsRuntimeMethod())) { bool found_one = false; for (size_t i = 0; i < static_cast(Runtime::kLastCalleeSaveType); ++i) { auto idx = static_cast(i); if (runtime->HasCalleeSaveMethod(idx) && runtime->GetCalleeSaveMethod(idx) == orig) { found_one = true; break; } } CHECK(found_one) << "Expected to find callee save method but got " << PrettyMethod(orig); CHECK(copy->IsRuntimeMethod()); } else { // We assume all methods have code. If they don't currently then we set them to the use the // resolution trampoline. Abstract methods never have code and so we need to make sure their // use results in an AbstractMethodError. We use the interpreter to achieve this. if (UNLIKELY(orig->IsAbstract())) { copy->SetEntryPointFromQuickCompiledCodePtrSize( GetOatAddress(quick_to_interpreter_bridge_offset_), target_ptr_size_); } else { bool quick_is_interpreted; const uint8_t* quick_code = GetQuickCode(orig, &quick_is_interpreted); copy->SetEntryPointFromQuickCompiledCodePtrSize(quick_code, target_ptr_size_); // JNI entrypoint: if (orig->IsNative()) { // The native method's pointer is set to a stub to lookup via dlsym. // Note this is not the code_ pointer, that is handled above. copy->SetEntryPointFromJniPtrSize( GetOatAddress(jni_dlsym_lookup_offset_), target_ptr_size_); } } } } static OatHeader* GetOatHeaderFromElf(ElfFile* elf) { uint64_t data_sec_offset; bool has_data_sec = elf->GetSectionOffsetAndSize(".rodata", &data_sec_offset, nullptr); if (!has_data_sec) { return nullptr; } return reinterpret_cast(elf->Begin() + data_sec_offset); } void ImageWriter::SetOatChecksumFromElfFile(File* elf_file) { std::string error_msg; std::unique_ptr elf(ElfFile::Open(elf_file, PROT_READ|PROT_WRITE, MAP_SHARED, &error_msg)); if (elf.get() == nullptr) { LOG(FATAL) << "Unable open oat file: " << error_msg; return; } OatHeader* oat_header = GetOatHeaderFromElf(elf.get()); CHECK(oat_header != nullptr); CHECK(oat_header->IsValid()); ImageHeader* image_header = reinterpret_cast(image_->Begin()); image_header->SetOatChecksum(oat_header->GetChecksum()); } size_t ImageWriter::GetBinSizeSum(ImageWriter::Bin up_to) const { DCHECK_LE(up_to, kBinSize); return std::accumulate(&bin_slot_sizes_[0], &bin_slot_sizes_[up_to], /*init*/0); } ImageWriter::BinSlot::BinSlot(uint32_t lockword) : lockword_(lockword) { // These values may need to get updated if more bins are added to the enum Bin static_assert(kBinBits == 3, "wrong number of bin bits"); static_assert(kBinShift == 27, "wrong number of shift"); static_assert(sizeof(BinSlot) == sizeof(LockWord), "BinSlot/LockWord must have equal sizes"); DCHECK_LT(GetBin(), kBinSize); DCHECK_ALIGNED(GetIndex(), kObjectAlignment); } ImageWriter::BinSlot::BinSlot(Bin bin, uint32_t index) : BinSlot(index | (static_cast(bin) << kBinShift)) { DCHECK_EQ(index, GetIndex()); } ImageWriter::Bin ImageWriter::BinSlot::GetBin() const { return static_cast((lockword_ & kBinMask) >> kBinShift); } uint32_t ImageWriter::BinSlot::GetIndex() const { return lockword_ & ~kBinMask; } uint8_t* ImageWriter::GetOatFileBegin() const { DCHECK_GT(intern_table_bytes_, 0u); size_t native_sections_size = bin_slot_sizes_[kBinArtField] + bin_slot_sizes_[kBinArtMethodDirty] + bin_slot_sizes_[kBinArtMethodClean] + bin_slot_sizes_[kBinDexCacheArray] + intern_table_bytes_; return image_begin_ + RoundUp(image_end_ + native_sections_size, kPageSize); } ImageWriter::Bin ImageWriter::BinTypeForNativeRelocationType(NativeObjectRelocationType type) { switch (type) { case kNativeObjectRelocationTypeArtField: case kNativeObjectRelocationTypeArtFieldArray: return kBinArtField; case kNativeObjectRelocationTypeArtMethodClean: case kNativeObjectRelocationTypeArtMethodArrayClean: return kBinArtMethodClean; case kNativeObjectRelocationTypeArtMethodDirty: case kNativeObjectRelocationTypeArtMethodArrayDirty: return kBinArtMethodDirty; case kNativeObjectRelocationTypeDexCacheArray: return kBinDexCacheArray; } UNREACHABLE(); } } // namespace art