/* * 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 "class_linker.h" #include #include #include #include #include #include #include #include #include "art_field-inl.h" #include "art_method-inl.h" #include "base/arena_allocator.h" #include "base/casts.h" #include "base/logging.h" #include "base/scoped_arena_containers.h" #include "base/scoped_flock.h" #include "base/stl_util.h" #include "base/time_utils.h" #include "base/unix_file/fd_file.h" #include "base/value_object.h" #include "class_linker-inl.h" #include "compiler_callbacks.h" #include "debugger.h" #include "dex_file-inl.h" #include "entrypoints/runtime_asm_entrypoints.h" #include "gc_root-inl.h" #include "gc/accounting/card_table-inl.h" #include "gc/accounting/heap_bitmap.h" #include "gc/heap.h" #include "gc/space/image_space.h" #include "handle_scope.h" #include "intern_table.h" #include "interpreter/interpreter.h" #include "jit/jit.h" #include "jit/jit_code_cache.h" #include "leb128.h" #include "linear_alloc.h" #include "oat.h" #include "oat_file.h" #include "oat_file_assistant.h" #include "object_lock.h" #include "mirror/class.h" #include "mirror/class-inl.h" #include "mirror/class_loader.h" #include "mirror/dex_cache-inl.h" #include "mirror/field.h" #include "mirror/iftable-inl.h" #include "mirror/method.h" #include "mirror/object-inl.h" #include "mirror/object_array-inl.h" #include "mirror/proxy.h" #include "mirror/reference-inl.h" #include "mirror/stack_trace_element.h" #include "mirror/string-inl.h" #include "os.h" #include "runtime.h" #include "entrypoints/entrypoint_utils.h" #include "ScopedLocalRef.h" #include "scoped_thread_state_change.h" #include "handle_scope-inl.h" #include "thread-inl.h" #include "utils.h" #include "verifier/method_verifier.h" #include "well_known_classes.h" namespace art { static constexpr bool kSanityCheckObjects = kIsDebugBuild; // For b/21333911. static constexpr bool kDuplicateClassesCheck = false; static void ThrowNoClassDefFoundError(const char* fmt, ...) __attribute__((__format__(__printf__, 1, 2))) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_); static void ThrowNoClassDefFoundError(const char* fmt, ...) { va_list args; va_start(args, fmt); Thread* self = Thread::Current(); self->ThrowNewExceptionV("Ljava/lang/NoClassDefFoundError;", fmt, args); va_end(args); } bool ClassLinker::HasInitWithString( Thread* self, ClassLinker* class_linker, const char* descriptor) { ArtMethod* method = self->GetCurrentMethod(nullptr); StackHandleScope<1> hs(self); Handle class_loader(hs.NewHandle(method != nullptr ? method->GetDeclaringClass()->GetClassLoader() : nullptr)); mirror::Class* exception_class = class_linker->FindClass(self, descriptor, class_loader); if (exception_class == nullptr) { // No exc class ~ no -with-string. CHECK(self->IsExceptionPending()); self->ClearException(); return false; } ArtMethod* exception_init_method = exception_class->FindDeclaredDirectMethod( "", "(Ljava/lang/String;)V", image_pointer_size_); return exception_init_method != nullptr; } void ClassLinker::ThrowEarlierClassFailure(mirror::Class* c) { // The class failed to initialize on a previous attempt, so we want to throw // a NoClassDefFoundError (v2 2.17.5). The exception to this rule is if we // failed in verification, in which case v2 5.4.1 says we need to re-throw // the previous error. Runtime* const runtime = Runtime::Current(); if (!runtime->IsAotCompiler()) { // Give info if this occurs at runtime. LOG(INFO) << "Rejecting re-init on previously-failed class " << PrettyClass(c); } CHECK(c->IsErroneous()) << PrettyClass(c) << " " << c->GetStatus(); Thread* self = Thread::Current(); if (runtime->IsAotCompiler()) { // At compile time, accurate errors and NCDFE are disabled to speed compilation. mirror::Throwable* pre_allocated = runtime->GetPreAllocatedNoClassDefFoundError(); self->SetException(pre_allocated); } else { if (c->GetVerifyErrorClass() != nullptr) { // TODO: change the verifier to store an _instance_, with a useful detail message? // It's possible the exception doesn't have a (String). std::string temp; const char* descriptor = c->GetVerifyErrorClass()->GetDescriptor(&temp); if (HasInitWithString(self, this, descriptor)) { self->ThrowNewException(descriptor, PrettyDescriptor(c).c_str()); } else { self->ThrowNewException(descriptor, nullptr); } } else { self->ThrowNewException("Ljava/lang/NoClassDefFoundError;", PrettyDescriptor(c).c_str()); } } } static void VlogClassInitializationFailure(Handle klass) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { if (VLOG_IS_ON(class_linker)) { std::string temp; LOG(INFO) << "Failed to initialize class " << klass->GetDescriptor(&temp) << " from " << klass->GetLocation() << "\n" << Thread::Current()->GetException()->Dump(); } } static void WrapExceptionInInitializer(Handle klass) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { Thread* self = Thread::Current(); JNIEnv* env = self->GetJniEnv(); ScopedLocalRef cause(env, env->ExceptionOccurred()); CHECK(cause.get() != nullptr); env->ExceptionClear(); bool is_error = env->IsInstanceOf(cause.get(), WellKnownClasses::java_lang_Error); env->Throw(cause.get()); // We only wrap non-Error exceptions; an Error can just be used as-is. if (!is_error) { self->ThrowNewWrappedException("Ljava/lang/ExceptionInInitializerError;", nullptr); } VlogClassInitializationFailure(klass); } // Gap between two fields in object layout. struct FieldGap { uint32_t start_offset; // The offset from the start of the object. uint32_t size; // The gap size of 1, 2, or 4 bytes. }; struct FieldGapsComparator { explicit FieldGapsComparator() { } bool operator() (const FieldGap& lhs, const FieldGap& rhs) NO_THREAD_SAFETY_ANALYSIS { // Sort by gap size, largest first. Secondary sort by starting offset. return lhs.size > rhs.size || (lhs.size == rhs.size && lhs.start_offset < rhs.start_offset); } }; typedef std::priority_queue, FieldGapsComparator> FieldGaps; // Adds largest aligned gaps to queue of gaps. static void AddFieldGap(uint32_t gap_start, uint32_t gap_end, FieldGaps* gaps) { DCHECK(gaps != nullptr); uint32_t current_offset = gap_start; while (current_offset != gap_end) { size_t remaining = gap_end - current_offset; if (remaining >= sizeof(uint32_t) && IsAligned<4>(current_offset)) { gaps->push(FieldGap {current_offset, sizeof(uint32_t)}); current_offset += sizeof(uint32_t); } else if (remaining >= sizeof(uint16_t) && IsAligned<2>(current_offset)) { gaps->push(FieldGap {current_offset, sizeof(uint16_t)}); current_offset += sizeof(uint16_t); } else { gaps->push(FieldGap {current_offset, sizeof(uint8_t)}); current_offset += sizeof(uint8_t); } DCHECK_LE(current_offset, gap_end) << "Overran gap"; } } // Shuffle fields forward, making use of gaps whenever possible. template static void ShuffleForward(size_t* current_field_idx, MemberOffset* field_offset, std::deque* grouped_and_sorted_fields, FieldGaps* gaps) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { DCHECK(current_field_idx != nullptr); DCHECK(grouped_and_sorted_fields != nullptr); DCHECK(gaps != nullptr); DCHECK(field_offset != nullptr); DCHECK(IsPowerOfTwo(n)); while (!grouped_and_sorted_fields->empty()) { ArtField* field = grouped_and_sorted_fields->front(); Primitive::Type type = field->GetTypeAsPrimitiveType(); if (Primitive::ComponentSize(type) < n) { break; } if (!IsAligned(field_offset->Uint32Value())) { MemberOffset old_offset = *field_offset; *field_offset = MemberOffset(RoundUp(field_offset->Uint32Value(), n)); AddFieldGap(old_offset.Uint32Value(), field_offset->Uint32Value(), gaps); } CHECK(type != Primitive::kPrimNot) << PrettyField(field); // should be primitive types grouped_and_sorted_fields->pop_front(); if (!gaps->empty() && gaps->top().size >= n) { FieldGap gap = gaps->top(); gaps->pop(); DCHECK(IsAligned(gap.start_offset)); field->SetOffset(MemberOffset(gap.start_offset)); if (gap.size > n) { AddFieldGap(gap.start_offset + n, gap.start_offset + gap.size, gaps); } } else { DCHECK(IsAligned(field_offset->Uint32Value())); field->SetOffset(*field_offset); *field_offset = MemberOffset(field_offset->Uint32Value() + n); } ++(*current_field_idx); } } ClassLinker::ClassLinker(InternTable* intern_table) // dex_lock_ is recursive as it may be used in stack dumping. : dex_lock_("ClassLinker dex lock", kDefaultMutexLevel), dex_cache_image_class_lookup_required_(false), failed_dex_cache_class_lookups_(0), class_roots_(nullptr), array_iftable_(nullptr), find_array_class_cache_next_victim_(0), init_done_(false), log_new_dex_caches_roots_(false), log_new_class_table_roots_(false), intern_table_(intern_table), quick_resolution_trampoline_(nullptr), quick_imt_conflict_trampoline_(nullptr), quick_generic_jni_trampoline_(nullptr), quick_to_interpreter_bridge_trampoline_(nullptr), image_pointer_size_(sizeof(void*)) { CHECK(intern_table_ != nullptr); static_assert(kFindArrayCacheSize == arraysize(find_array_class_cache_), "Array cache size wrong."); std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot(nullptr)); } void ClassLinker::InitWithoutImage(std::vector> boot_class_path) { VLOG(startup) << "ClassLinker::Init"; Thread* const self = Thread::Current(); Runtime* const runtime = Runtime::Current(); gc::Heap* const heap = runtime->GetHeap(); CHECK(!heap->HasImageSpace()) << "Runtime has image. We should use it."; CHECK(!init_done_); // Use the pointer size from the runtime since we are probably creating the image. image_pointer_size_ = InstructionSetPointerSize(runtime->GetInstructionSet()); // java_lang_Class comes first, it's needed for AllocClass // The GC can't handle an object with a null class since we can't get the size of this object. heap->IncrementDisableMovingGC(self); StackHandleScope<64> hs(self); // 64 is picked arbitrarily. auto class_class_size = mirror::Class::ClassClassSize(image_pointer_size_); Handle java_lang_Class(hs.NewHandle(down_cast( heap->AllocNonMovableObject(self, nullptr, class_class_size, VoidFunctor())))); CHECK(java_lang_Class.Get() != nullptr); mirror::Class::SetClassClass(java_lang_Class.Get()); java_lang_Class->SetClass(java_lang_Class.Get()); if (kUseBakerOrBrooksReadBarrier) { java_lang_Class->AssertReadBarrierPointer(); } java_lang_Class->SetClassSize(class_class_size); java_lang_Class->SetPrimitiveType(Primitive::kPrimNot); heap->DecrementDisableMovingGC(self); // AllocClass(mirror::Class*) can now be used // Class[] is used for reflection support. auto class_array_class_size = mirror::ObjectArray::ClassSize(image_pointer_size_); Handle class_array_class(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), class_array_class_size))); class_array_class->SetComponentType(java_lang_Class.Get()); // java_lang_Object comes next so that object_array_class can be created. Handle java_lang_Object(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::Object::ClassSize(image_pointer_size_)))); CHECK(java_lang_Object.Get() != nullptr); // backfill Object as the super class of Class. java_lang_Class->SetSuperClass(java_lang_Object.Get()); mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusLoaded, self); // Object[] next to hold class roots. Handle object_array_class(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::ObjectArray::ClassSize(image_pointer_size_)))); object_array_class->SetComponentType(java_lang_Object.Get()); // Setup the char (primitive) class to be used for char[]. Handle char_class(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::Class::PrimitiveClassSize(image_pointer_size_)))); // The primitive char class won't be initialized by // InitializePrimitiveClass until line 459, but strings (and // internal char arrays) will be allocated before that and the // component size, which is computed from the primitive type, needs // to be set here. char_class->SetPrimitiveType(Primitive::kPrimChar); // Setup the char[] class to be used for String. Handle char_array_class(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); char_array_class->SetComponentType(char_class.Get()); mirror::CharArray::SetArrayClass(char_array_class.Get()); // Setup String. Handle java_lang_String(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::String::ClassSize(image_pointer_size_)))); mirror::String::SetClass(java_lang_String.Get()); mirror::Class::SetStatus(java_lang_String, mirror::Class::kStatusResolved, self); java_lang_String->SetStringClass(); // Setup java.lang.ref.Reference. Handle java_lang_ref_Reference(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::Reference::ClassSize(image_pointer_size_)))); mirror::Reference::SetClass(java_lang_ref_Reference.Get()); java_lang_ref_Reference->SetObjectSize(mirror::Reference::InstanceSize()); mirror::Class::SetStatus(java_lang_ref_Reference, mirror::Class::kStatusResolved, self); // Create storage for root classes, save away our work so far (requires descriptors). class_roots_ = GcRoot>( mirror::ObjectArray::Alloc(self, object_array_class.Get(), kClassRootsMax)); CHECK(!class_roots_.IsNull()); SetClassRoot(kJavaLangClass, java_lang_Class.Get()); SetClassRoot(kJavaLangObject, java_lang_Object.Get()); SetClassRoot(kClassArrayClass, class_array_class.Get()); SetClassRoot(kObjectArrayClass, object_array_class.Get()); SetClassRoot(kCharArrayClass, char_array_class.Get()); SetClassRoot(kJavaLangString, java_lang_String.Get()); SetClassRoot(kJavaLangRefReference, java_lang_ref_Reference.Get()); // Setup the primitive type classes. SetClassRoot(kPrimitiveBoolean, CreatePrimitiveClass(self, Primitive::kPrimBoolean)); SetClassRoot(kPrimitiveByte, CreatePrimitiveClass(self, Primitive::kPrimByte)); SetClassRoot(kPrimitiveShort, CreatePrimitiveClass(self, Primitive::kPrimShort)); SetClassRoot(kPrimitiveInt, CreatePrimitiveClass(self, Primitive::kPrimInt)); SetClassRoot(kPrimitiveLong, CreatePrimitiveClass(self, Primitive::kPrimLong)); SetClassRoot(kPrimitiveFloat, CreatePrimitiveClass(self, Primitive::kPrimFloat)); SetClassRoot(kPrimitiveDouble, CreatePrimitiveClass(self, Primitive::kPrimDouble)); SetClassRoot(kPrimitiveVoid, CreatePrimitiveClass(self, Primitive::kPrimVoid)); // Create array interface entries to populate once we can load system classes. array_iftable_ = GcRoot(AllocIfTable(self, 2)); // Create int array type for AllocDexCache (done in AppendToBootClassPath). Handle int_array_class(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); int_array_class->SetComponentType(GetClassRoot(kPrimitiveInt)); mirror::IntArray::SetArrayClass(int_array_class.Get()); SetClassRoot(kIntArrayClass, int_array_class.Get()); // Create long array type for AllocDexCache (done in AppendToBootClassPath). Handle long_array_class(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::Array::ClassSize(image_pointer_size_)))); long_array_class->SetComponentType(GetClassRoot(kPrimitiveLong)); mirror::LongArray::SetArrayClass(long_array_class.Get()); SetClassRoot(kLongArrayClass, long_array_class.Get()); // now that these are registered, we can use AllocClass() and AllocObjectArray // Set up DexCache. This cannot be done later since AppendToBootClassPath calls AllocDexCache. Handle java_lang_DexCache(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::DexCache::ClassSize(image_pointer_size_)))); SetClassRoot(kJavaLangDexCache, java_lang_DexCache.Get()); java_lang_DexCache->SetObjectSize(mirror::DexCache::InstanceSize()); mirror::Class::SetStatus(java_lang_DexCache, mirror::Class::kStatusResolved, self); // Set up array classes for string, field, method Handle object_array_string(hs.NewHandle( AllocClass(self, java_lang_Class.Get(), mirror::ObjectArray::ClassSize(image_pointer_size_)))); object_array_string->SetComponentType(java_lang_String.Get()); SetClassRoot(kJavaLangStringArrayClass, object_array_string.Get()); // Create runtime resolution and imt conflict methods. runtime->SetResolutionMethod(runtime->CreateResolutionMethod()); runtime->SetImtConflictMethod(runtime->CreateImtConflictMethod()); runtime->SetImtUnimplementedMethod(runtime->CreateImtConflictMethod()); // Setup boot_class_path_ and register class_path now that we can use AllocObjectArray to create // DexCache instances. Needs to be after String, Field, Method arrays since AllocDexCache uses // these roots. CHECK_NE(0U, boot_class_path.size()); for (auto& dex_file : boot_class_path) { CHECK(dex_file.get() != nullptr); AppendToBootClassPath(self, *dex_file); opened_dex_files_.push_back(std::move(dex_file)); } // now we can use FindSystemClass // run char class through InitializePrimitiveClass to finish init InitializePrimitiveClass(char_class.Get(), Primitive::kPrimChar); SetClassRoot(kPrimitiveChar, char_class.Get()); // needs descriptor // Set up GenericJNI entrypoint. That is mainly a hack for common_compiler_test.h so that // we do not need friend classes or a publicly exposed setter. quick_generic_jni_trampoline_ = GetQuickGenericJniStub(); if (!runtime->IsAotCompiler()) { // We need to set up the generic trampolines since we don't have an image. quick_resolution_trampoline_ = GetQuickResolutionStub(); quick_imt_conflict_trampoline_ = GetQuickImtConflictStub(); quick_to_interpreter_bridge_trampoline_ = GetQuickToInterpreterBridge(); } // Object, String and DexCache need to be rerun through FindSystemClass to finish init mirror::Class::SetStatus(java_lang_Object, mirror::Class::kStatusNotReady, self); CHECK_EQ(java_lang_Object.Get(), FindSystemClass(self, "Ljava/lang/Object;")); CHECK_EQ(java_lang_Object->GetObjectSize(), mirror::Object::InstanceSize()); mirror::Class::SetStatus(java_lang_String, mirror::Class::kStatusNotReady, self); mirror::Class* String_class = FindSystemClass(self, "Ljava/lang/String;"); if (java_lang_String.Get() != String_class) { std::ostringstream os1, os2; java_lang_String->DumpClass(os1, mirror::Class::kDumpClassFullDetail); String_class->DumpClass(os2, mirror::Class::kDumpClassFullDetail); LOG(FATAL) << os1.str() << "\n\n" << os2.str(); } mirror::Class::SetStatus(java_lang_DexCache, mirror::Class::kStatusNotReady, self); CHECK_EQ(java_lang_DexCache.Get(), FindSystemClass(self, "Ljava/lang/DexCache;")); CHECK_EQ(java_lang_DexCache->GetObjectSize(), mirror::DexCache::InstanceSize()); // Setup the primitive array type classes - can't be done until Object has a vtable. SetClassRoot(kBooleanArrayClass, FindSystemClass(self, "[Z")); mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass)); SetClassRoot(kByteArrayClass, FindSystemClass(self, "[B")); mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass)); CHECK_EQ(char_array_class.Get(), FindSystemClass(self, "[C")); SetClassRoot(kShortArrayClass, FindSystemClass(self, "[S")); mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass)); CHECK_EQ(int_array_class.Get(), FindSystemClass(self, "[I")); CHECK_EQ(long_array_class.Get(), FindSystemClass(self, "[J")); SetClassRoot(kFloatArrayClass, FindSystemClass(self, "[F")); mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass)); SetClassRoot(kDoubleArrayClass, FindSystemClass(self, "[D")); mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass)); CHECK_EQ(class_array_class.Get(), FindSystemClass(self, "[Ljava/lang/Class;")); CHECK_EQ(object_array_class.Get(), FindSystemClass(self, "[Ljava/lang/Object;")); // Setup the single, global copy of "iftable". auto java_lang_Cloneable = hs.NewHandle(FindSystemClass(self, "Ljava/lang/Cloneable;")); CHECK(java_lang_Cloneable.Get() != nullptr); auto java_io_Serializable = hs.NewHandle(FindSystemClass(self, "Ljava/io/Serializable;")); CHECK(java_io_Serializable.Get() != nullptr); // We assume that Cloneable/Serializable don't have superinterfaces -- normally we'd have to // crawl up and explicitly list all of the supers as well. array_iftable_.Read()->SetInterface(0, java_lang_Cloneable.Get()); array_iftable_.Read()->SetInterface(1, java_io_Serializable.Get()); // Sanity check Class[] and Object[]'s interfaces. GetDirectInterface may cause thread // suspension. CHECK_EQ(java_lang_Cloneable.Get(), mirror::Class::GetDirectInterface(self, class_array_class, 0)); CHECK_EQ(java_io_Serializable.Get(), mirror::Class::GetDirectInterface(self, class_array_class, 1)); CHECK_EQ(java_lang_Cloneable.Get(), mirror::Class::GetDirectInterface(self, object_array_class, 0)); CHECK_EQ(java_io_Serializable.Get(), mirror::Class::GetDirectInterface(self, object_array_class, 1)); // Run Class, ArtField, and ArtMethod through FindSystemClass. This initializes their // dex_cache_ fields and register them in class_table_. CHECK_EQ(java_lang_Class.Get(), FindSystemClass(self, "Ljava/lang/Class;")); CHECK_EQ(object_array_string.Get(), FindSystemClass(self, GetClassRootDescriptor(kJavaLangStringArrayClass))); // End of special init trickery, subsequent classes may be loaded via FindSystemClass. // Create java.lang.reflect.Proxy root. SetClassRoot(kJavaLangReflectProxy, FindSystemClass(self, "Ljava/lang/reflect/Proxy;")); // Create java.lang.reflect.Field.class root. auto* class_root = FindSystemClass(self, "Ljava/lang/reflect/Field;"); CHECK(class_root != nullptr); SetClassRoot(kJavaLangReflectField, class_root); mirror::Field::SetClass(class_root); // Create java.lang.reflect.Field array root. class_root = FindSystemClass(self, "[Ljava/lang/reflect/Field;"); CHECK(class_root != nullptr); SetClassRoot(kJavaLangReflectFieldArrayClass, class_root); mirror::Field::SetArrayClass(class_root); // Create java.lang.reflect.Constructor.class root and array root. class_root = FindSystemClass(self, "Ljava/lang/reflect/Constructor;"); CHECK(class_root != nullptr); SetClassRoot(kJavaLangReflectConstructor, class_root); mirror::Constructor::SetClass(class_root); class_root = FindSystemClass(self, "[Ljava/lang/reflect/Constructor;"); CHECK(class_root != nullptr); SetClassRoot(kJavaLangReflectConstructorArrayClass, class_root); mirror::Constructor::SetArrayClass(class_root); // Create java.lang.reflect.Method.class root and array root. class_root = FindSystemClass(self, "Ljava/lang/reflect/Method;"); CHECK(class_root != nullptr); SetClassRoot(kJavaLangReflectMethod, class_root); mirror::Method::SetClass(class_root); class_root = FindSystemClass(self, "[Ljava/lang/reflect/Method;"); CHECK(class_root != nullptr); SetClassRoot(kJavaLangReflectMethodArrayClass, class_root); mirror::Method::SetArrayClass(class_root); // java.lang.ref classes need to be specially flagged, but otherwise are normal classes // finish initializing Reference class mirror::Class::SetStatus(java_lang_ref_Reference, mirror::Class::kStatusNotReady, self); CHECK_EQ(java_lang_ref_Reference.Get(), FindSystemClass(self, "Ljava/lang/ref/Reference;")); CHECK_EQ(java_lang_ref_Reference->GetObjectSize(), mirror::Reference::InstanceSize()); CHECK_EQ(java_lang_ref_Reference->GetClassSize(), mirror::Reference::ClassSize(image_pointer_size_)); class_root = FindSystemClass(self, "Ljava/lang/ref/FinalizerReference;"); class_root->SetAccessFlags(class_root->GetAccessFlags() | kAccClassIsReference | kAccClassIsFinalizerReference); class_root = FindSystemClass(self, "Ljava/lang/ref/PhantomReference;"); class_root->SetAccessFlags(class_root->GetAccessFlags() | kAccClassIsReference | kAccClassIsPhantomReference); class_root = FindSystemClass(self, "Ljava/lang/ref/SoftReference;"); class_root->SetAccessFlags(class_root->GetAccessFlags() | kAccClassIsReference); class_root = FindSystemClass(self, "Ljava/lang/ref/WeakReference;"); class_root->SetAccessFlags(class_root->GetAccessFlags() | kAccClassIsReference | kAccClassIsWeakReference); // Setup the ClassLoader, verifying the object_size_. class_root = FindSystemClass(self, "Ljava/lang/ClassLoader;"); CHECK_EQ(class_root->GetObjectSize(), mirror::ClassLoader::InstanceSize()); SetClassRoot(kJavaLangClassLoader, class_root); // Set up java.lang.Throwable, java.lang.ClassNotFoundException, and // java.lang.StackTraceElement as a convenience. SetClassRoot(kJavaLangThrowable, FindSystemClass(self, "Ljava/lang/Throwable;")); mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable)); SetClassRoot(kJavaLangClassNotFoundException, FindSystemClass(self, "Ljava/lang/ClassNotFoundException;")); SetClassRoot(kJavaLangStackTraceElement, FindSystemClass(self, "Ljava/lang/StackTraceElement;")); SetClassRoot(kJavaLangStackTraceElementArrayClass, FindSystemClass(self, "[Ljava/lang/StackTraceElement;")); mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement)); // Ensure void type is resolved in the core's dex cache so java.lang.Void is correctly // initialized. { const DexFile& dex_file = java_lang_Object->GetDexFile(); const DexFile::StringId* void_string_id = dex_file.FindStringId("V"); CHECK(void_string_id != nullptr); uint32_t void_string_index = dex_file.GetIndexForStringId(*void_string_id); const DexFile::TypeId* void_type_id = dex_file.FindTypeId(void_string_index); CHECK(void_type_id != nullptr); uint16_t void_type_idx = dex_file.GetIndexForTypeId(*void_type_id); // Now we resolve void type so the dex cache contains it. We use java.lang.Object class // as referrer so the used dex cache is core's one. mirror::Class* resolved_type = ResolveType(dex_file, void_type_idx, java_lang_Object.Get()); CHECK_EQ(resolved_type, GetClassRoot(kPrimitiveVoid)); self->AssertNoPendingException(); } FinishInit(self); VLOG(startup) << "ClassLinker::InitFromCompiler exiting"; } void ClassLinker::FinishInit(Thread* self) { VLOG(startup) << "ClassLinker::FinishInit entering"; // Let the heap know some key offsets into java.lang.ref instances // Note: we hard code the field indexes here rather than using FindInstanceField // as the types of the field can't be resolved prior to the runtime being // fully initialized mirror::Class* java_lang_ref_Reference = GetClassRoot(kJavaLangRefReference); mirror::Class* java_lang_ref_FinalizerReference = FindSystemClass(self, "Ljava/lang/ref/FinalizerReference;"); ArtField* pendingNext = java_lang_ref_Reference->GetInstanceField(0); CHECK_STREQ(pendingNext->GetName(), "pendingNext"); CHECK_STREQ(pendingNext->GetTypeDescriptor(), "Ljava/lang/ref/Reference;"); ArtField* queue = java_lang_ref_Reference->GetInstanceField(1); CHECK_STREQ(queue->GetName(), "queue"); CHECK_STREQ(queue->GetTypeDescriptor(), "Ljava/lang/ref/ReferenceQueue;"); ArtField* queueNext = java_lang_ref_Reference->GetInstanceField(2); CHECK_STREQ(queueNext->GetName(), "queueNext"); CHECK_STREQ(queueNext->GetTypeDescriptor(), "Ljava/lang/ref/Reference;"); ArtField* referent = java_lang_ref_Reference->GetInstanceField(3); CHECK_STREQ(referent->GetName(), "referent"); CHECK_STREQ(referent->GetTypeDescriptor(), "Ljava/lang/Object;"); ArtField* zombie = java_lang_ref_FinalizerReference->GetInstanceField(2); CHECK_STREQ(zombie->GetName(), "zombie"); CHECK_STREQ(zombie->GetTypeDescriptor(), "Ljava/lang/Object;"); // ensure all class_roots_ are initialized for (size_t i = 0; i < kClassRootsMax; i++) { ClassRoot class_root = static_cast(i); mirror::Class* klass = GetClassRoot(class_root); CHECK(klass != nullptr); DCHECK(klass->IsArrayClass() || klass->IsPrimitive() || klass->GetDexCache() != nullptr); // note SetClassRoot does additional validation. // if possible add new checks there to catch errors early } CHECK(!array_iftable_.IsNull()); // disable the slow paths in FindClass and CreatePrimitiveClass now // that Object, Class, and Object[] are setup init_done_ = true; VLOG(startup) << "ClassLinker::FinishInit exiting"; } void ClassLinker::RunRootClinits() { Thread* self = Thread::Current(); for (size_t i = 0; i < ClassLinker::kClassRootsMax; ++i) { mirror::Class* c = GetClassRoot(ClassRoot(i)); if (!c->IsArrayClass() && !c->IsPrimitive()) { StackHandleScope<1> hs(self); Handle h_class(hs.NewHandle(GetClassRoot(ClassRoot(i)))); EnsureInitialized(self, h_class, true, true); self->AssertNoPendingException(); } } } const OatFile* ClassLinker::RegisterOatFile(const OatFile* oat_file) { WriterMutexLock mu(Thread::Current(), dex_lock_); if (kIsDebugBuild) { for (size_t i = 0; i < oat_files_.size(); ++i) { CHECK_NE(oat_file, oat_files_[i]) << oat_file->GetLocation(); } } VLOG(class_linker) << "Registering " << oat_file->GetLocation(); oat_files_.push_back(oat_file); return oat_file; } OatFile& ClassLinker::GetImageOatFile(gc::space::ImageSpace* space) { VLOG(startup) << "ClassLinker::GetImageOatFile entering"; OatFile* oat_file = space->ReleaseOatFile(); CHECK_EQ(RegisterOatFile(oat_file), oat_file); VLOG(startup) << "ClassLinker::GetImageOatFile exiting"; return *oat_file; } class DexFileAndClassPair : ValueObject { public: DexFileAndClassPair(const DexFile* dex_file, size_t current_class_index, bool from_loaded_oat) : cached_descriptor_(GetClassDescriptor(dex_file, current_class_index)), dex_file_(dex_file), current_class_index_(current_class_index), from_loaded_oat_(from_loaded_oat) {} DexFileAndClassPair(const DexFileAndClassPair&) = default; DexFileAndClassPair& operator=(const DexFileAndClassPair& rhs) { cached_descriptor_ = rhs.cached_descriptor_; dex_file_ = rhs.dex_file_; current_class_index_ = rhs.current_class_index_; from_loaded_oat_ = rhs.from_loaded_oat_; return *this; } const char* GetCachedDescriptor() const { return cached_descriptor_; } bool operator<(const DexFileAndClassPair& rhs) const { const char* lhsDescriptor = cached_descriptor_; const char* rhsDescriptor = rhs.cached_descriptor_; int cmp = strcmp(lhsDescriptor, rhsDescriptor); if (cmp != 0) { // Note that the order must be reversed. We want to iterate over the classes in dex files. // They are sorted lexicographically. Thus, the priority-queue must be a min-queue. return cmp > 0; } return dex_file_ < rhs.dex_file_; } bool DexFileHasMoreClasses() const { return current_class_index_ + 1 < dex_file_->NumClassDefs(); } DexFileAndClassPair GetNext() const { return DexFileAndClassPair(dex_file_, current_class_index_ + 1, from_loaded_oat_); } size_t GetCurrentClassIndex() const { return current_class_index_; } bool FromLoadedOat() const { return from_loaded_oat_; } const DexFile* GetDexFile() const { return dex_file_; } void DeleteDexFile() { delete dex_file_; dex_file_ = nullptr; } private: static const char* GetClassDescriptor(const DexFile* dex_file, size_t index) { const DexFile::ClassDef& class_def = dex_file->GetClassDef(static_cast(index)); return dex_file->StringByTypeIdx(class_def.class_idx_); } const char* cached_descriptor_; const DexFile* dex_file_; size_t current_class_index_; bool from_loaded_oat_; // We only need to compare mismatches between what we load now // and what was loaded before. Any old duplicates must have been // OK, and any new "internal" duplicates are as well (they must // be from multidex, which resolves correctly). }; static void AddDexFilesFromOat(const OatFile* oat_file, bool already_loaded, std::priority_queue* heap) { const std::vector& oat_dex_files = oat_file->GetOatDexFiles(); for (const OatDexFile* oat_dex_file : oat_dex_files) { std::string error; std::unique_ptr dex_file = oat_dex_file->OpenDexFile(&error); if (dex_file.get() == nullptr) { LOG(WARNING) << "Could not create dex file from oat file: " << error; } else { if (dex_file->NumClassDefs() > 0U) { heap->emplace(dex_file.release(), 0U, already_loaded); } } } } static void AddNext(DexFileAndClassPair* original, std::priority_queue* heap) { if (original->DexFileHasMoreClasses()) { heap->push(original->GetNext()); } else { // Need to delete the dex file. original->DeleteDexFile(); } } static void FreeDexFilesInHeap(std::priority_queue* heap) { while (!heap->empty()) { delete heap->top().GetDexFile(); heap->pop(); } } const OatFile* ClassLinker::GetBootOatFile() { gc::space::ImageSpace* image_space = Runtime::Current()->GetHeap()->GetImageSpace(); if (image_space == nullptr) { return nullptr; } return image_space->GetOatFile(); } const OatFile* ClassLinker::GetPrimaryOatFile() { ReaderMutexLock mu(Thread::Current(), dex_lock_); const OatFile* boot_oat_file = GetBootOatFile(); if (boot_oat_file != nullptr) { for (const OatFile* oat_file : oat_files_) { if (oat_file != boot_oat_file) { return oat_file; } } } return nullptr; } // Check for class-def collisions in dex files. // // This works by maintaining a heap with one class from each dex file, sorted by the class // descriptor. Then a dex-file/class pair is continually removed from the heap and compared // against the following top element. If the descriptor is the same, it is now checked whether // the two elements agree on whether their dex file was from an already-loaded oat-file or the // new oat file. Any disagreement indicates a collision. bool ClassLinker::HasCollisions(const OatFile* oat_file, std::string* error_msg) { if (!kDuplicateClassesCheck) { return false; } // Dex files are registered late - once a class is actually being loaded. We have to compare // against the open oat files. Take the dex_lock_ that protects oat_files_ accesses. ReaderMutexLock mu(Thread::Current(), dex_lock_); std::priority_queue queue; // Add dex files from already loaded oat files, but skip boot. { const OatFile* boot_oat = GetBootOatFile(); for (const OatFile* loaded_oat_file : oat_files_) { if (loaded_oat_file == boot_oat) { continue; } AddDexFilesFromOat(loaded_oat_file, true, &queue); } } if (queue.empty()) { // No other oat files, return early. return false; } // Add dex files from the oat file to check. AddDexFilesFromOat(oat_file, false, &queue); // Now drain the queue. while (!queue.empty()) { DexFileAndClassPair compare_pop = queue.top(); queue.pop(); // Compare against the following elements. while (!queue.empty()) { DexFileAndClassPair top = queue.top(); if (strcmp(compare_pop.GetCachedDescriptor(), top.GetCachedDescriptor()) == 0) { // Same descriptor. Check whether it's crossing old-oat-files to new-oat-files. if (compare_pop.FromLoadedOat() != top.FromLoadedOat()) { *error_msg = StringPrintf("Found duplicated class when checking oat files: '%s' in %s and %s", compare_pop.GetCachedDescriptor(), compare_pop.GetDexFile()->GetLocation().c_str(), top.GetDexFile()->GetLocation().c_str()); FreeDexFilesInHeap(&queue); return true; } // Pop it. queue.pop(); AddNext(&top, &queue); } else { // Something else. Done here. break; } } AddNext(&compare_pop, &queue); } return false; } std::vector> ClassLinker::OpenDexFilesFromOat( const char* dex_location, const char* oat_location, std::vector* error_msgs) { CHECK(error_msgs != nullptr); // Verify we aren't holding the mutator lock, which could starve GC if we // have to generate or relocate an oat file. Locks::mutator_lock_->AssertNotHeld(Thread::Current()); OatFileAssistant oat_file_assistant(dex_location, oat_location, kRuntimeISA, !Runtime::Current()->IsAotCompiler()); // Lock the target oat location to avoid races generating and loading the // oat file. std::string error_msg; if (!oat_file_assistant.Lock(&error_msg)) { // Don't worry too much if this fails. If it does fail, it's unlikely we // can generate an oat file anyway. VLOG(class_linker) << "OatFileAssistant::Lock: " << error_msg; } // Check if we already have an up-to-date oat file open. const OatFile* source_oat_file = nullptr; { ReaderMutexLock mu(Thread::Current(), dex_lock_); for (const OatFile* oat_file : oat_files_) { CHECK(oat_file != nullptr); if (oat_file_assistant.GivenOatFileIsUpToDate(*oat_file)) { source_oat_file = oat_file; break; } } } // If we didn't have an up-to-date oat file open, try to load one from disk. if (source_oat_file == nullptr) { // Update the oat file on disk if we can. This may fail, but that's okay. // Best effort is all that matters here. if (!oat_file_assistant.MakeUpToDate(&error_msg)) { LOG(WARNING) << error_msg; } // Get the oat file on disk. std::unique_ptr oat_file = oat_file_assistant.GetBestOatFile(); if (oat_file.get() != nullptr) { // Take the file only if it has no collisions, or we must take it because of preopting. bool accept_oat_file = !HasCollisions(oat_file.get(), &error_msg); if (!accept_oat_file) { // Failed the collision check. Print warning. if (Runtime::Current()->IsDexFileFallbackEnabled()) { LOG(WARNING) << "Found duplicate classes, falling back to interpreter mode for " << dex_location; } else { LOG(WARNING) << "Found duplicate classes, dex-file-fallback disabled, will be failing to " " load classes for " << dex_location; } LOG(WARNING) << error_msg; // However, if the app was part of /system and preopted, there is no original dex file // available. In that case grudgingly accept the oat file. if (!DexFile::MaybeDex(dex_location)) { accept_oat_file = true; LOG(WARNING) << "Dex location " << dex_location << " does not seem to include dex file. " << "Allow oat file use. This is potentially dangerous."; } } if (accept_oat_file) { source_oat_file = oat_file.release(); RegisterOatFile(source_oat_file); } } } std::vector> dex_files; // Load the dex files from the oat file. if (source_oat_file != nullptr) { dex_files = oat_file_assistant.LoadDexFiles(*source_oat_file, dex_location); if (dex_files.empty()) { error_msgs->push_back("Failed to open dex files from " + source_oat_file->GetLocation()); } } // Fall back to running out of the original dex file if we couldn't load any // dex_files from the oat file. if (dex_files.empty()) { if (oat_file_assistant.HasOriginalDexFiles()) { if (Runtime::Current()->IsDexFileFallbackEnabled()) { if (!DexFile::Open(dex_location, dex_location, &error_msg, &dex_files)) { LOG(WARNING) << error_msg; error_msgs->push_back("Failed to open dex files from " + std::string(dex_location)); } } else { error_msgs->push_back("Fallback mode disabled, skipping dex files."); } } else { error_msgs->push_back("No original dex files found for dex location " + std::string(dex_location)); } } return dex_files; } const OatFile* ClassLinker::FindOpenedOatFileFromOatLocation(const std::string& oat_location) { ReaderMutexLock mu(Thread::Current(), dex_lock_); for (size_t i = 0; i < oat_files_.size(); i++) { const OatFile* oat_file = oat_files_[i]; DCHECK(oat_file != nullptr); if (oat_file->GetLocation() == oat_location) { return oat_file; } } return nullptr; } static void SanityCheckArtMethod(ArtMethod* m, mirror::Class* expected_class, gc::space::ImageSpace* space) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { if (m->IsRuntimeMethod()) { CHECK(m->GetDeclaringClass() == nullptr) << PrettyMethod(m); } else if (m->IsMiranda()) { CHECK(m->GetDeclaringClass() != nullptr) << PrettyMethod(m); } else if (expected_class != nullptr) { CHECK_EQ(m->GetDeclaringClassUnchecked(), expected_class) << PrettyMethod(m); } if (space != nullptr) { auto& header = space->GetImageHeader(); auto& methods = header.GetMethodsSection(); auto offset = reinterpret_cast(m) - space->Begin(); CHECK(methods.Contains(offset)) << m << " not in " << methods; } } static void SanityCheckArtMethodPointerArray( mirror::PointerArray* arr, mirror::Class* expected_class, size_t pointer_size, gc::space::ImageSpace* space) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { CHECK(arr != nullptr); for (int32_t j = 0; j < arr->GetLength(); ++j) { auto* method = arr->GetElementPtrSize(j, pointer_size); // expected_class == null means we are a dex cache. if (expected_class != nullptr) { CHECK(method != nullptr); } if (method != nullptr) { SanityCheckArtMethod(method, expected_class, space); } } } static void SanityCheckObjectsCallback(mirror::Object* obj, void* arg ATTRIBUTE_UNUSED) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { DCHECK(obj != nullptr); CHECK(obj->GetClass() != nullptr) << "Null class in object " << obj; CHECK(obj->GetClass()->GetClass() != nullptr) << "Null class class " << obj; if (obj->IsClass()) { auto klass = obj->AsClass(); ArtField* fields[2] = { klass->GetSFields(), klass->GetIFields() }; size_t num_fields[2] = { klass->NumStaticFields(), klass->NumInstanceFields() }; for (size_t i = 0; i < 2; ++i) { for (size_t j = 0; j < num_fields[i]; ++j) { CHECK_EQ(fields[i][j].GetDeclaringClass(), klass); } } auto* runtime = Runtime::Current(); auto* image_space = runtime->GetHeap()->GetImageSpace(); auto pointer_size = runtime->GetClassLinker()->GetImagePointerSize(); for (auto& m : klass->GetDirectMethods(pointer_size)) { SanityCheckArtMethod(&m, klass, image_space); } for (auto& m : klass->GetVirtualMethods(pointer_size)) { SanityCheckArtMethod(&m, klass, image_space); } auto* vtable = klass->GetVTable(); if (vtable != nullptr) { SanityCheckArtMethodPointerArray(vtable, nullptr, pointer_size, image_space); } if (klass->ShouldHaveEmbeddedImtAndVTable()) { for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { SanityCheckArtMethod(klass->GetEmbeddedImTableEntry(i, pointer_size), nullptr, image_space); } for (int32_t i = 0; i < klass->GetEmbeddedVTableLength(); ++i) { SanityCheckArtMethod(klass->GetEmbeddedVTableEntry(i, pointer_size), nullptr, image_space); } } auto* iftable = klass->GetIfTable(); if (iftable != nullptr) { for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { if (iftable->GetMethodArrayCount(i) > 0) { SanityCheckArtMethodPointerArray(iftable->GetMethodArray(i), nullptr, pointer_size, image_space); } } } } } void ClassLinker::InitFromImage() { VLOG(startup) << "ClassLinker::InitFromImage entering"; CHECK(!init_done_); Runtime* const runtime = Runtime::Current(); Thread* const self = Thread::Current(); gc::Heap* const heap = runtime->GetHeap(); gc::space::ImageSpace* const space = heap->GetImageSpace(); CHECK(space != nullptr); image_pointer_size_ = space->GetImageHeader().GetPointerSize(); dex_cache_image_class_lookup_required_ = true; OatFile& oat_file = GetImageOatFile(space); CHECK_EQ(oat_file.GetOatHeader().GetImageFileLocationOatChecksum(), 0U); CHECK_EQ(oat_file.GetOatHeader().GetImageFileLocationOatDataBegin(), 0U); const char* image_file_location = oat_file.GetOatHeader(). GetStoreValueByKey(OatHeader::kImageLocationKey); CHECK(image_file_location == nullptr || *image_file_location == 0); quick_resolution_trampoline_ = oat_file.GetOatHeader().GetQuickResolutionTrampoline(); quick_imt_conflict_trampoline_ = oat_file.GetOatHeader().GetQuickImtConflictTrampoline(); quick_generic_jni_trampoline_ = oat_file.GetOatHeader().GetQuickGenericJniTrampoline(); quick_to_interpreter_bridge_trampoline_ = oat_file.GetOatHeader().GetQuickToInterpreterBridge(); mirror::Object* dex_caches_object = space->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); mirror::ObjectArray* dex_caches = dex_caches_object->AsObjectArray(); StackHandleScope<1> hs(self); Handle> class_roots(hs.NewHandle( space->GetImageHeader().GetImageRoot(ImageHeader::kClassRoots)-> AsObjectArray())); class_roots_ = GcRoot>(class_roots.Get()); // Special case of setting up the String class early so that we can test arbitrary objects // as being Strings or not mirror::String::SetClass(GetClassRoot(kJavaLangString)); CHECK_EQ(oat_file.GetOatHeader().GetDexFileCount(), static_cast(dex_caches->GetLength())); for (int32_t i = 0; i < dex_caches->GetLength(); i++) { StackHandleScope<1> hs2(self); Handle dex_cache(hs2.NewHandle(dex_caches->Get(i))); const std::string& dex_file_location(dex_cache->GetLocation()->ToModifiedUtf8()); const OatFile::OatDexFile* oat_dex_file = oat_file.GetOatDexFile(dex_file_location.c_str(), nullptr); CHECK(oat_dex_file != nullptr) << oat_file.GetLocation() << " " << dex_file_location; std::string error_msg; std::unique_ptr dex_file = oat_dex_file->OpenDexFile(&error_msg); if (dex_file.get() == nullptr) { LOG(FATAL) << "Failed to open dex file " << dex_file_location << " from within oat file " << oat_file.GetLocation() << " error '" << error_msg << "'"; UNREACHABLE(); } if (kSanityCheckObjects) { SanityCheckArtMethodPointerArray(dex_cache->GetResolvedMethods(), nullptr, image_pointer_size_, space); } CHECK_EQ(dex_file->GetLocationChecksum(), oat_dex_file->GetDexFileLocationChecksum()); AppendToBootClassPath(*dex_file.get(), dex_cache); opened_dex_files_.push_back(std::move(dex_file)); } CHECK(ValidPointerSize(image_pointer_size_)) << image_pointer_size_; // Set classes on AbstractMethod early so that IsMethod tests can be performed during the live // bitmap walk. if (!runtime->IsAotCompiler()) { // Only the Aot compiler supports having an image with a different pointer size than the // runtime. This happens on the host for compile 32 bit tests since we use a 64 bit libart // compiler. We may also use 32 bit dex2oat on a system with 64 bit apps. CHECK_EQ(image_pointer_size_, sizeof(void*)); } if (kSanityCheckObjects) { for (int32_t i = 0; i < dex_caches->GetLength(); i++) { auto* dex_cache = dex_caches->Get(i); for (size_t j = 0; j < dex_cache->NumResolvedFields(); ++j) { auto* field = dex_cache->GetResolvedField(j, image_pointer_size_); if (field != nullptr) { CHECK(field->GetDeclaringClass()->GetClass() != nullptr); } } } heap->VisitObjects(SanityCheckObjectsCallback, nullptr); } // Set entry point to interpreter if in InterpretOnly mode. if (!runtime->IsAotCompiler() && runtime->GetInstrumentation()->InterpretOnly()) { const auto& header = space->GetImageHeader(); const auto& methods = header.GetMethodsSection(); const auto art_method_size = ArtMethod::ObjectSize(image_pointer_size_); for (uintptr_t pos = 0; pos < methods.Size(); pos += art_method_size) { auto* method = reinterpret_cast(space->Begin() + pos + methods.Offset()); if (kIsDebugBuild && !method->IsRuntimeMethod()) { CHECK(method->GetDeclaringClass() != nullptr); } if (!method->IsNative()) { method->SetEntryPointFromInterpreterPtrSize( artInterpreterToInterpreterBridge, image_pointer_size_); if (!method->IsRuntimeMethod() && method != runtime->GetResolutionMethod()) { method->SetEntryPointFromQuickCompiledCodePtrSize(GetQuickToInterpreterBridge(), image_pointer_size_); } } } } // reinit class_roots_ mirror::Class::SetClassClass(class_roots->Get(kJavaLangClass)); class_roots_ = GcRoot>(class_roots.Get()); // reinit array_iftable_ from any array class instance, they should be == array_iftable_ = GcRoot(GetClassRoot(kObjectArrayClass)->GetIfTable()); DCHECK_EQ(array_iftable_.Read(), GetClassRoot(kBooleanArrayClass)->GetIfTable()); // String class root was set above mirror::Field::SetClass(GetClassRoot(kJavaLangReflectField)); mirror::Field::SetArrayClass(GetClassRoot(kJavaLangReflectFieldArrayClass)); mirror::Constructor::SetClass(GetClassRoot(kJavaLangReflectConstructor)); mirror::Constructor::SetArrayClass(GetClassRoot(kJavaLangReflectConstructorArrayClass)); mirror::Method::SetClass(GetClassRoot(kJavaLangReflectMethod)); mirror::Method::SetArrayClass(GetClassRoot(kJavaLangReflectMethodArrayClass)); mirror::Reference::SetClass(GetClassRoot(kJavaLangRefReference)); mirror::BooleanArray::SetArrayClass(GetClassRoot(kBooleanArrayClass)); mirror::ByteArray::SetArrayClass(GetClassRoot(kByteArrayClass)); mirror::CharArray::SetArrayClass(GetClassRoot(kCharArrayClass)); mirror::DoubleArray::SetArrayClass(GetClassRoot(kDoubleArrayClass)); mirror::FloatArray::SetArrayClass(GetClassRoot(kFloatArrayClass)); mirror::IntArray::SetArrayClass(GetClassRoot(kIntArrayClass)); mirror::LongArray::SetArrayClass(GetClassRoot(kLongArrayClass)); mirror::ShortArray::SetArrayClass(GetClassRoot(kShortArrayClass)); mirror::Throwable::SetClass(GetClassRoot(kJavaLangThrowable)); mirror::StackTraceElement::SetClass(GetClassRoot(kJavaLangStackTraceElement)); FinishInit(self); VLOG(startup) << "ClassLinker::InitFromImage exiting"; } bool ClassLinker::ClassInClassTable(mirror::Class* klass) { ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); auto it = class_table_.Find(GcRoot(klass)); if (it == class_table_.end()) { return false; } return it->Read() == klass; } void ClassLinker::VisitClassRoots(RootVisitor* visitor, VisitRootFlags flags) { WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); BufferedRootVisitor buffered_visitor( visitor, RootInfo(kRootStickyClass)); if ((flags & kVisitRootFlagAllRoots) != 0) { // Argument for how root visiting deals with ArtField and ArtMethod roots. // There is 3 GC cases to handle: // Non moving concurrent: // This case is easy to handle since the reference members of ArtMethod and ArtFields are held // live by the class and class roots. In this case we probably don't even need to call // VisitNativeRoots. // // Moving non-concurrent: // This case needs to call visit VisitNativeRoots in case the classes or dex cache arrays move. // To prevent missing roots, this case needs to ensure that there is no // suspend points between the point which we allocate ArtMethod arrays and place them in a // class which is in the class table. // // Moving concurrent: // Need to make sure to not copy ArtMethods without doing read barriers since the roots are // marked concurrently and we don't hold the classlinker_classes_lock_ when we do the copy. for (GcRoot& root : class_table_) { buffered_visitor.VisitRoot(root); if ((flags & kVisitRootFlagNonMoving) == 0) { // Don't bother visiting ArtField and ArtMethod if kVisitRootFlagNonMoving is set since // these roots are all reachable from the class or dex cache. root.Read()->VisitNativeRoots(buffered_visitor, image_pointer_size_); } } // PreZygote classes can't move so we won't need to update fields' declaring classes. for (GcRoot& root : pre_zygote_class_table_) { buffered_visitor.VisitRoot(root); if ((flags & kVisitRootFlagNonMoving) == 0) { root.Read()->VisitNativeRoots(buffered_visitor, image_pointer_size_); } } } else if ((flags & kVisitRootFlagNewRoots) != 0) { for (auto& root : new_class_roots_) { mirror::Class* old_ref = root.Read(); old_ref->VisitNativeRoots(buffered_visitor, image_pointer_size_); root.VisitRoot(visitor, RootInfo(kRootStickyClass)); mirror::Class* new_ref = root.Read(); if (UNLIKELY(new_ref != old_ref)) { // Uh ohes, GC moved a root in the log. Need to search the class_table and update the // corresponding object. This is slow, but luckily for us, this may only happen with a // concurrent moving GC. auto it = class_table_.Find(GcRoot(old_ref)); DCHECK(it != class_table_.end()); *it = GcRoot(new_ref); } } } buffered_visitor.Flush(); // Flush before clearing new_class_roots_. if ((flags & kVisitRootFlagClearRootLog) != 0) { new_class_roots_.clear(); } if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) { log_new_class_table_roots_ = true; } else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) { log_new_class_table_roots_ = false; } // We deliberately ignore the class roots in the image since we // handle image roots by using the MS/CMS rescanning of dirty cards. } // Keep in sync with InitCallback. Anything we visit, we need to // reinit references to when reinitializing a ClassLinker from a // mapped image. void ClassLinker::VisitRoots(RootVisitor* visitor, VisitRootFlags flags) { class_roots_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); Thread* const self = Thread::Current(); { ReaderMutexLock mu(self, dex_lock_); if ((flags & kVisitRootFlagAllRoots) != 0) { for (GcRoot& dex_cache : dex_caches_) { dex_cache.VisitRoot(visitor, RootInfo(kRootVMInternal)); } } else if ((flags & kVisitRootFlagNewRoots) != 0) { for (size_t index : new_dex_cache_roots_) { dex_caches_[index].VisitRoot(visitor, RootInfo(kRootVMInternal)); } } if ((flags & kVisitRootFlagClearRootLog) != 0) { new_dex_cache_roots_.clear(); } if ((flags & kVisitRootFlagStartLoggingNewRoots) != 0) { log_new_dex_caches_roots_ = true; } else if ((flags & kVisitRootFlagStopLoggingNewRoots) != 0) { log_new_dex_caches_roots_ = false; } } VisitClassRoots(visitor, flags); array_iftable_.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); for (GcRoot& root : find_array_class_cache_) { root.VisitRootIfNonNull(visitor, RootInfo(kRootVMInternal)); } } void ClassLinker::VisitClasses(ClassVisitor* visitor, void* arg) { if (dex_cache_image_class_lookup_required_) { MoveImageClassesToClassTable(); } // TODO: why isn't this a ReaderMutexLock? WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); for (GcRoot& root : class_table_) { if (!visitor(root.Read(), arg)) { return; } } for (GcRoot& root : pre_zygote_class_table_) { if (!visitor(root.Read(), arg)) { return; } } } static bool GetClassesVisitorSet(mirror::Class* c, void* arg) { std::set* classes = reinterpret_cast*>(arg); classes->insert(c); return true; } struct GetClassesVisitorArrayArg { Handle>* classes; int32_t index; bool success; }; static bool GetClassesVisitorArray(mirror::Class* c, void* varg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { GetClassesVisitorArrayArg* arg = reinterpret_cast(varg); if (arg->index < (*arg->classes)->GetLength()) { (*arg->classes)->Set(arg->index, c); arg->index++; return true; } else { arg->success = false; return false; } } void ClassLinker::VisitClassesWithoutClassesLock(ClassVisitor* visitor, void* arg) { // TODO: it may be possible to avoid secondary storage if we iterate over dex caches. The problem // is avoiding duplicates. if (!kMovingClasses) { std::set classes; VisitClasses(GetClassesVisitorSet, &classes); for (mirror::Class* klass : classes) { if (!visitor(klass, arg)) { return; } } } else { Thread* self = Thread::Current(); StackHandleScope<1> hs(self); MutableHandle> classes = hs.NewHandle>(nullptr); GetClassesVisitorArrayArg local_arg; local_arg.classes = &classes; local_arg.success = false; // We size the array assuming classes won't be added to the class table during the visit. // If this assumption fails we iterate again. while (!local_arg.success) { size_t class_table_size; { ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); class_table_size = class_table_.Size() + pre_zygote_class_table_.Size(); } mirror::Class* class_type = mirror::Class::GetJavaLangClass(); mirror::Class* array_of_class = FindArrayClass(self, &class_type); classes.Assign( mirror::ObjectArray::Alloc(self, array_of_class, class_table_size)); CHECK(classes.Get() != nullptr); // OOME. local_arg.index = 0; local_arg.success = true; VisitClasses(GetClassesVisitorArray, &local_arg); } for (int32_t i = 0; i < classes->GetLength(); ++i) { // If the class table shrank during creation of the clases array we expect null elements. If // the class table grew then the loop repeats. If classes are created after the loop has // finished then we don't visit. mirror::Class* klass = classes->Get(i); if (klass != nullptr && !visitor(klass, arg)) { return; } } } } ClassLinker::~ClassLinker() { mirror::Class::ResetClass(); mirror::Constructor::ResetClass(); mirror::Field::ResetClass(); mirror::Method::ResetClass(); mirror::Reference::ResetClass(); mirror::StackTraceElement::ResetClass(); mirror::String::ResetClass(); mirror::Throwable::ResetClass(); mirror::BooleanArray::ResetArrayClass(); mirror::ByteArray::ResetArrayClass(); mirror::CharArray::ResetArrayClass(); mirror::Constructor::ResetArrayClass(); mirror::DoubleArray::ResetArrayClass(); mirror::Field::ResetArrayClass(); mirror::FloatArray::ResetArrayClass(); mirror::Method::ResetArrayClass(); mirror::IntArray::ResetArrayClass(); mirror::LongArray::ResetArrayClass(); mirror::ShortArray::ResetArrayClass(); STLDeleteElements(&oat_files_); } mirror::PointerArray* ClassLinker::AllocPointerArray(Thread* self, size_t length) { return down_cast(image_pointer_size_ == 8u ? static_cast(mirror::LongArray::Alloc(self, length)) : static_cast(mirror::IntArray::Alloc(self, length))); } mirror::DexCache* ClassLinker::AllocDexCache(Thread* self, const DexFile& dex_file) { StackHandleScope<6> hs(self); auto dex_cache(hs.NewHandle(down_cast( GetClassRoot(kJavaLangDexCache)->AllocObject(self)))); if (dex_cache.Get() == nullptr) { self->AssertPendingOOMException(); return nullptr; } auto location(hs.NewHandle(intern_table_->InternStrong(dex_file.GetLocation().c_str()))); if (location.Get() == nullptr) { self->AssertPendingOOMException(); return nullptr; } auto strings(hs.NewHandle(AllocStringArray(self, dex_file.NumStringIds()))); if (strings.Get() == nullptr) { self->AssertPendingOOMException(); return nullptr; } auto types(hs.NewHandle(AllocClassArray(self, dex_file.NumTypeIds()))); if (types.Get() == nullptr) { self->AssertPendingOOMException(); return nullptr; } auto methods(hs.NewHandle(AllocPointerArray(self, dex_file.NumMethodIds()))); if (methods.Get() == nullptr) { self->AssertPendingOOMException(); return nullptr; } auto fields(hs.NewHandle(AllocPointerArray(self, dex_file.NumFieldIds()))); if (fields.Get() == nullptr) { self->AssertPendingOOMException(); return nullptr; } dex_cache->Init(&dex_file, location.Get(), strings.Get(), types.Get(), methods.Get(), fields.Get(), image_pointer_size_); return dex_cache.Get(); } mirror::Class* ClassLinker::AllocClass(Thread* self, mirror::Class* java_lang_Class, uint32_t class_size) { DCHECK_GE(class_size, sizeof(mirror::Class)); gc::Heap* heap = Runtime::Current()->GetHeap(); mirror::Class::InitializeClassVisitor visitor(class_size); mirror::Object* k = kMovingClasses ? heap->AllocObject(self, java_lang_Class, class_size, visitor) : heap->AllocNonMovableObject(self, java_lang_Class, class_size, visitor); if (UNLIKELY(k == nullptr)) { self->AssertPendingOOMException(); return nullptr; } return k->AsClass(); } mirror::Class* ClassLinker::AllocClass(Thread* self, uint32_t class_size) { return AllocClass(self, GetClassRoot(kJavaLangClass), class_size); } mirror::ObjectArray* ClassLinker::AllocStackTraceElementArray( Thread* self, size_t length) { return mirror::ObjectArray::Alloc( self, GetClassRoot(kJavaLangStackTraceElementArrayClass), length); } mirror::Class* ClassLinker::EnsureResolved(Thread* self, const char* descriptor, mirror::Class* klass) { DCHECK(klass != nullptr); // For temporary classes we must wait for them to be retired. if (init_done_ && klass->IsTemp()) { CHECK(!klass->IsResolved()); if (klass->IsErroneous()) { ThrowEarlierClassFailure(klass); return nullptr; } StackHandleScope<1> hs(self); Handle h_class(hs.NewHandle(klass)); ObjectLock lock(self, h_class); // Loop and wait for the resolving thread to retire this class. while (!h_class->IsRetired() && !h_class->IsErroneous()) { lock.WaitIgnoringInterrupts(); } if (h_class->IsErroneous()) { ThrowEarlierClassFailure(h_class.Get()); return nullptr; } CHECK(h_class->IsRetired()); // Get the updated class from class table. klass = LookupClass(self, descriptor, ComputeModifiedUtf8Hash(descriptor), h_class.Get()->GetClassLoader()); } // Wait for the class if it has not already been linked. if (!klass->IsResolved() && !klass->IsErroneous()) { StackHandleScope<1> hs(self); HandleWrapper h_class(hs.NewHandleWrapper(&klass)); ObjectLock lock(self, h_class); // Check for circular dependencies between classes. if (!h_class->IsResolved() && h_class->GetClinitThreadId() == self->GetTid()) { ThrowClassCircularityError(h_class.Get()); mirror::Class::SetStatus(h_class, mirror::Class::kStatusError, self); return nullptr; } // Wait for the pending initialization to complete. while (!h_class->IsResolved() && !h_class->IsErroneous()) { lock.WaitIgnoringInterrupts(); } } if (klass->IsErroneous()) { ThrowEarlierClassFailure(klass); return nullptr; } // Return the loaded class. No exceptions should be pending. CHECK(klass->IsResolved()) << PrettyClass(klass); self->AssertNoPendingException(); return klass; } typedef std::pair ClassPathEntry; // Search a collection of DexFiles for a descriptor ClassPathEntry FindInClassPath(const char* descriptor, size_t hash, const std::vector& class_path) { for (const DexFile* dex_file : class_path) { const DexFile::ClassDef* dex_class_def = dex_file->FindClassDef(descriptor, hash); if (dex_class_def != nullptr) { return ClassPathEntry(dex_file, dex_class_def); } } return ClassPathEntry(nullptr, nullptr); } static bool IsBootClassLoader(ScopedObjectAccessAlreadyRunnable& soa, mirror::ClassLoader* class_loader) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { return class_loader == nullptr || class_loader->GetClass() == soa.Decode(WellKnownClasses::java_lang_BootClassLoader); } bool ClassLinker::FindClassInPathClassLoader(ScopedObjectAccessAlreadyRunnable& soa, Thread* self, const char* descriptor, size_t hash, Handle class_loader, mirror::Class** result) { // Termination case: boot class-loader. if (IsBootClassLoader(soa, class_loader.Get())) { // The boot class loader, search the boot class path. ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_); if (pair.second != nullptr) { mirror::Class* klass = LookupClass(self, descriptor, hash, nullptr); if (klass != nullptr) { *result = EnsureResolved(self, descriptor, klass); } else { *result = DefineClass(self, descriptor, hash, NullHandle(), *pair.first, *pair.second); } if (*result == nullptr) { CHECK(self->IsExceptionPending()) << descriptor; self->ClearException(); } } else { *result = nullptr; } return true; } // Unsupported class-loader? if (class_loader->GetClass() != soa.Decode(WellKnownClasses::dalvik_system_PathClassLoader)) { *result = nullptr; return false; } // Handles as RegisterDexFile may allocate dex caches (and cause thread suspension). StackHandleScope<4> hs(self); Handle h_parent(hs.NewHandle(class_loader->GetParent())); bool recursive_result = FindClassInPathClassLoader(soa, self, descriptor, hash, h_parent, result); if (!recursive_result) { // Something wrong up the chain. return false; } if (*result != nullptr) { // Found the class up the chain. return true; } // Handle this step. // Handle as if this is the child PathClassLoader. // The class loader is a PathClassLoader which inherits from BaseDexClassLoader. // We need to get the DexPathList and loop through it. ArtField* const cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie); ArtField* const dex_file_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); mirror::Object* dex_path_list = soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList)-> GetObject(class_loader.Get()); if (dex_path_list != nullptr && dex_file_field != nullptr && cookie_field != nullptr) { // DexPathList has an array dexElements of Elements[] which each contain a dex file. mirror::Object* dex_elements_obj = soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements)-> GetObject(dex_path_list); // Loop through each dalvik.system.DexPathList$Element's dalvik.system.DexFile and look // at the mCookie which is a DexFile vector. if (dex_elements_obj != nullptr) { Handle> dex_elements = hs.NewHandle(dex_elements_obj->AsObjectArray()); for (int32_t i = 0; i < dex_elements->GetLength(); ++i) { mirror::Object* element = dex_elements->GetWithoutChecks(i); if (element == nullptr) { // Should never happen, fall back to java code to throw a NPE. break; } mirror::Object* dex_file = dex_file_field->GetObject(element); if (dex_file != nullptr) { mirror::LongArray* long_array = cookie_field->GetObject(dex_file)->AsLongArray(); if (long_array == nullptr) { // This should never happen so log a warning. LOG(WARNING) << "Null DexFile::mCookie for " << descriptor; break; } int32_t long_array_size = long_array->GetLength(); for (int32_t j = 0; j < long_array_size; ++j) { const DexFile* cp_dex_file = reinterpret_cast(static_cast( long_array->GetWithoutChecks(j))); const DexFile::ClassDef* dex_class_def = cp_dex_file->FindClassDef(descriptor, hash); if (dex_class_def != nullptr) { RegisterDexFile(*cp_dex_file); mirror::Class* klass = DefineClass(self, descriptor, hash, class_loader, *cp_dex_file, *dex_class_def); if (klass == nullptr) { CHECK(self->IsExceptionPending()) << descriptor; self->ClearException(); // TODO: Is it really right to break here, and not check the other dex files? return true; } *result = klass; return true; } } } } } self->AssertNoPendingException(); } // Result is still null from the parent call, no need to set it again... return true; } mirror::Class* ClassLinker::FindClass(Thread* self, const char* descriptor, Handle class_loader) { DCHECK_NE(*descriptor, '\0') << "descriptor is empty string"; DCHECK(self != nullptr); self->AssertNoPendingException(); if (descriptor[1] == '\0') { // only the descriptors of primitive types should be 1 character long, also avoid class lookup // for primitive classes that aren't backed by dex files. return FindPrimitiveClass(descriptor[0]); } const size_t hash = ComputeModifiedUtf8Hash(descriptor); // Find the class in the loaded classes table. mirror::Class* klass = LookupClass(self, descriptor, hash, class_loader.Get()); if (klass != nullptr) { return EnsureResolved(self, descriptor, klass); } // Class is not yet loaded. if (descriptor[0] == '[') { return CreateArrayClass(self, descriptor, hash, class_loader); } else if (class_loader.Get() == nullptr) { // The boot class loader, search the boot class path. ClassPathEntry pair = FindInClassPath(descriptor, hash, boot_class_path_); if (pair.second != nullptr) { return DefineClass(self, descriptor, hash, NullHandle(), *pair.first, *pair.second); } else { // The boot class loader is searched ahead of the application class loader, failures are // expected and will be wrapped in a ClassNotFoundException. Use the pre-allocated error to // trigger the chaining with a proper stack trace. mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); self->SetException(pre_allocated); return nullptr; } } else { ScopedObjectAccessUnchecked soa(self); mirror::Class* cp_klass; if (FindClassInPathClassLoader(soa, self, descriptor, hash, class_loader, &cp_klass)) { // The chain was understood. So the value in cp_klass is either the class we were looking // for, or not found. if (cp_klass != nullptr) { return cp_klass; } // TODO: We handle the boot classpath loader in FindClassInPathClassLoader. Try to unify this // and the branch above. TODO: throw the right exception here. // We'll let the Java-side rediscover all this and throw the exception with the right stack // trace. } if (Runtime::Current()->IsAotCompiler()) { // Oops, compile-time, can't run actual class-loader code. mirror::Throwable* pre_allocated = Runtime::Current()->GetPreAllocatedNoClassDefFoundError(); self->SetException(pre_allocated); return nullptr; } ScopedLocalRef class_loader_object(soa.Env(), soa.AddLocalReference(class_loader.Get())); std::string class_name_string(DescriptorToDot(descriptor)); ScopedLocalRef result(soa.Env(), nullptr); { ScopedThreadStateChange tsc(self, kNative); ScopedLocalRef class_name_object(soa.Env(), soa.Env()->NewStringUTF(class_name_string.c_str())); if (class_name_object.get() == nullptr) { DCHECK(self->IsExceptionPending()); // OOME. return nullptr; } CHECK(class_loader_object.get() != nullptr); result.reset(soa.Env()->CallObjectMethod(class_loader_object.get(), WellKnownClasses::java_lang_ClassLoader_loadClass, class_name_object.get())); } if (self->IsExceptionPending()) { // If the ClassLoader threw, pass that exception up. return nullptr; } else if (result.get() == nullptr) { // broken loader - throw NPE to be compatible with Dalvik ThrowNullPointerException(StringPrintf("ClassLoader.loadClass returned null for %s", class_name_string.c_str()).c_str()); return nullptr; } else { // success, return mirror::Class* return soa.Decode(result.get()); } } UNREACHABLE(); } mirror::Class* ClassLinker::DefineClass(Thread* self, const char* descriptor, size_t hash, Handle class_loader, const DexFile& dex_file, const DexFile::ClassDef& dex_class_def) { StackHandleScope<3> hs(self); auto klass = hs.NewHandle(nullptr); // Load the class from the dex file. if (UNLIKELY(!init_done_)) { // finish up init of hand crafted class_roots_ if (strcmp(descriptor, "Ljava/lang/Object;") == 0) { klass.Assign(GetClassRoot(kJavaLangObject)); } else if (strcmp(descriptor, "Ljava/lang/Class;") == 0) { klass.Assign(GetClassRoot(kJavaLangClass)); } else if (strcmp(descriptor, "Ljava/lang/String;") == 0) { klass.Assign(GetClassRoot(kJavaLangString)); } else if (strcmp(descriptor, "Ljava/lang/ref/Reference;") == 0) { klass.Assign(GetClassRoot(kJavaLangRefReference)); } else if (strcmp(descriptor, "Ljava/lang/DexCache;") == 0) { klass.Assign(GetClassRoot(kJavaLangDexCache)); } } if (klass.Get() == nullptr) { // Allocate a class with the status of not ready. // Interface object should get the right size here. Regular class will // figure out the right size later and be replaced with one of the right // size when the class becomes resolved. klass.Assign(AllocClass(self, SizeOfClassWithoutEmbeddedTables(dex_file, dex_class_def))); } if (UNLIKELY(klass.Get() == nullptr)) { CHECK(self->IsExceptionPending()); // Expect an OOME. return nullptr; } klass->SetDexCache(FindDexCache(dex_file)); SetupClass(dex_file, dex_class_def, klass, class_loader.Get()); // Mark the string class by setting its access flag. if (UNLIKELY(!init_done_)) { if (strcmp(descriptor, "Ljava/lang/String;") == 0) { klass->SetStringClass(); } } ObjectLock lock(self, klass); klass->SetClinitThreadId(self->GetTid()); // Add the newly loaded class to the loaded classes table. mirror::Class* existing = InsertClass(descriptor, klass.Get(), hash); if (existing != nullptr) { // We failed to insert because we raced with another thread. Calling EnsureResolved may cause // this thread to block. return EnsureResolved(self, descriptor, existing); } // Load the fields and other things after we are inserted in the table. This is so that we don't // end up allocating unfree-able linear alloc resources and then lose the race condition. The // other reason is that the field roots are only visited from the class table. So we need to be // inserted before we allocate / fill in these fields. LoadClass(self, dex_file, dex_class_def, klass); if (self->IsExceptionPending()) { // An exception occured during load, set status to erroneous while holding klass' lock in case // notification is necessary. if (!klass->IsErroneous()) { mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); } return nullptr; } // Finish loading (if necessary) by finding parents CHECK(!klass->IsLoaded()); if (!LoadSuperAndInterfaces(klass, dex_file)) { // Loading failed. if (!klass->IsErroneous()) { mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); } return nullptr; } CHECK(klass->IsLoaded()); // Link the class (if necessary) CHECK(!klass->IsResolved()); // TODO: Use fast jobjects? auto interfaces = hs.NewHandle>(nullptr); MutableHandle h_new_class = hs.NewHandle(nullptr); if (!LinkClass(self, descriptor, klass, interfaces, &h_new_class)) { // Linking failed. if (!klass->IsErroneous()) { mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); } return nullptr; } self->AssertNoPendingException(); CHECK(h_new_class.Get() != nullptr) << descriptor; CHECK(h_new_class->IsResolved()) << descriptor; // Instrumentation may have updated entrypoints for all methods of all // classes. However it could not update methods of this class while we // were loading it. Now the class is resolved, we can update entrypoints // as required by instrumentation. if (Runtime::Current()->GetInstrumentation()->AreExitStubsInstalled()) { // We must be in the kRunnable state to prevent instrumentation from // suspending all threads to update entrypoints while we are doing it // for this class. DCHECK_EQ(self->GetState(), kRunnable); Runtime::Current()->GetInstrumentation()->InstallStubsForClass(h_new_class.Get()); } /* * We send CLASS_PREPARE events to the debugger from here. The * definition of "preparation" is creating the static fields for a * class and initializing them to the standard default values, but not * executing any code (that comes later, during "initialization"). * * We did the static preparation in LinkClass. * * The class has been prepared and resolved but possibly not yet verified * at this point. */ Dbg::PostClassPrepare(h_new_class.Get()); return h_new_class.Get(); } uint32_t ClassLinker::SizeOfClassWithoutEmbeddedTables(const DexFile& dex_file, const DexFile::ClassDef& dex_class_def) { const uint8_t* class_data = dex_file.GetClassData(dex_class_def); size_t num_ref = 0; size_t num_8 = 0; size_t num_16 = 0; size_t num_32 = 0; size_t num_64 = 0; if (class_data != nullptr) { for (ClassDataItemIterator it(dex_file, class_data); it.HasNextStaticField(); it.Next()) { const DexFile::FieldId& field_id = dex_file.GetFieldId(it.GetMemberIndex()); const char* descriptor = dex_file.GetFieldTypeDescriptor(field_id); char c = descriptor[0]; switch (c) { case 'L': case '[': num_ref++; break; case 'J': case 'D': num_64++; break; case 'I': case 'F': num_32++; break; case 'S': case 'C': num_16++; break; case 'B': case 'Z': num_8++; break; default: LOG(FATAL) << "Unknown descriptor: " << c; UNREACHABLE(); } } } return mirror::Class::ComputeClassSize(false, 0, num_8, num_16, num_32, num_64, num_ref, image_pointer_size_); } OatFile::OatClass ClassLinker::FindOatClass(const DexFile& dex_file, uint16_t class_def_idx, bool* found) { DCHECK_NE(class_def_idx, DexFile::kDexNoIndex16); const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); if (oat_dex_file == nullptr) { *found = false; return OatFile::OatClass::Invalid(); } *found = true; return oat_dex_file->GetOatClass(class_def_idx); } static uint32_t GetOatMethodIndexFromMethodIndex(const DexFile& dex_file, uint16_t class_def_idx, uint32_t method_idx) { const DexFile::ClassDef& class_def = dex_file.GetClassDef(class_def_idx); const uint8_t* class_data = dex_file.GetClassData(class_def); CHECK(class_data != nullptr); ClassDataItemIterator it(dex_file, class_data); // Skip fields while (it.HasNextStaticField()) { it.Next(); } while (it.HasNextInstanceField()) { it.Next(); } // Process methods size_t class_def_method_index = 0; while (it.HasNextDirectMethod()) { if (it.GetMemberIndex() == method_idx) { return class_def_method_index; } class_def_method_index++; it.Next(); } while (it.HasNextVirtualMethod()) { if (it.GetMemberIndex() == method_idx) { return class_def_method_index; } class_def_method_index++; it.Next(); } DCHECK(!it.HasNext()); LOG(FATAL) << "Failed to find method index " << method_idx << " in " << dex_file.GetLocation(); UNREACHABLE(); } const OatFile::OatMethod ClassLinker::FindOatMethodFor(ArtMethod* method, bool* found) { // Although we overwrite the trampoline of non-static methods, we may get here via the resolution // method for direct methods (or virtual methods made direct). mirror::Class* declaring_class = method->GetDeclaringClass(); size_t oat_method_index; if (method->IsStatic() || method->IsDirect()) { // Simple case where the oat method index was stashed at load time. oat_method_index = method->GetMethodIndex(); } else { // We're invoking a virtual method directly (thanks to sharpening), compute the oat_method_index // by search for its position in the declared virtual methods. oat_method_index = declaring_class->NumDirectMethods(); size_t end = declaring_class->NumVirtualMethods(); bool found_virtual = false; for (size_t i = 0; i < end; i++) { // Check method index instead of identity in case of duplicate method definitions. if (method->GetDexMethodIndex() == declaring_class->GetVirtualMethod(i, image_pointer_size_)->GetDexMethodIndex()) { found_virtual = true; break; } oat_method_index++; } CHECK(found_virtual) << "Didn't find oat method index for virtual method: " << PrettyMethod(method); } DCHECK_EQ(oat_method_index, GetOatMethodIndexFromMethodIndex(*declaring_class->GetDexCache()->GetDexFile(), method->GetDeclaringClass()->GetDexClassDefIndex(), method->GetDexMethodIndex())); OatFile::OatClass oat_class = FindOatClass(*declaring_class->GetDexCache()->GetDexFile(), declaring_class->GetDexClassDefIndex(), found); if (!(*found)) { return OatFile::OatMethod::Invalid(); } return oat_class.GetOatMethod(oat_method_index); } // Special case to get oat code without overwriting a trampoline. const void* ClassLinker::GetQuickOatCodeFor(ArtMethod* method) { CHECK(!method->IsAbstract()) << PrettyMethod(method); if (method->IsProxyMethod()) { return GetQuickProxyInvokeHandler(); } bool found; OatFile::OatMethod oat_method = FindOatMethodFor(method, &found); if (found) { auto* code = oat_method.GetQuickCode(); if (code != nullptr) { return code; } } jit::Jit* const jit = Runtime::Current()->GetJit(); if (jit != nullptr) { auto* code = jit->GetCodeCache()->GetCodeFor(method); if (code != nullptr) { return code; } } if (method->IsNative()) { // No code and native? Use generic trampoline. return GetQuickGenericJniStub(); } return GetQuickToInterpreterBridge(); } const void* ClassLinker::GetOatMethodQuickCodeFor(ArtMethod* method) { if (method->IsNative() || method->IsAbstract() || method->IsProxyMethod()) { return nullptr; } bool found; OatFile::OatMethod oat_method = FindOatMethodFor(method, &found); if (found) { return oat_method.GetQuickCode(); } jit::Jit* jit = Runtime::Current()->GetJit(); if (jit != nullptr) { auto* code = jit->GetCodeCache()->GetCodeFor(method); if (code != nullptr) { return code; } } return nullptr; } const void* ClassLinker::GetQuickOatCodeFor(const DexFile& dex_file, uint16_t class_def_idx, uint32_t method_idx) { bool found; OatFile::OatClass oat_class = FindOatClass(dex_file, class_def_idx, &found); if (!found) { return nullptr; } uint32_t oat_method_idx = GetOatMethodIndexFromMethodIndex(dex_file, class_def_idx, method_idx); return oat_class.GetOatMethod(oat_method_idx).GetQuickCode(); } // Returns true if the method must run with interpreter, false otherwise. static bool NeedsInterpreter(ArtMethod* method, const void* quick_code) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { if (quick_code == nullptr) { // No code: need interpreter. // May return true for native code, in the case of generic JNI // DCHECK(!method->IsNative()); return true; } // If interpreter mode is enabled, every method (except native and proxy) must // be run with interpreter. return Runtime::Current()->GetInstrumentation()->InterpretOnly() && !method->IsNative() && !method->IsProxyMethod(); } void ClassLinker::FixupStaticTrampolines(mirror::Class* klass) { DCHECK(klass->IsInitialized()) << PrettyDescriptor(klass); if (klass->NumDirectMethods() == 0) { return; // No direct methods => no static methods. } Runtime* runtime = Runtime::Current(); if (!runtime->IsStarted()) { if (runtime->IsAotCompiler() || runtime->GetHeap()->HasImageSpace()) { return; // OAT file unavailable. } } const DexFile& dex_file = klass->GetDexFile(); const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); CHECK(dex_class_def != nullptr); const uint8_t* class_data = dex_file.GetClassData(*dex_class_def); // There should always be class data if there were direct methods. CHECK(class_data != nullptr) << PrettyDescriptor(klass); ClassDataItemIterator it(dex_file, class_data); // Skip fields while (it.HasNextStaticField()) { it.Next(); } while (it.HasNextInstanceField()) { it.Next(); } bool has_oat_class; OatFile::OatClass oat_class = FindOatClass(dex_file, klass->GetDexClassDefIndex(), &has_oat_class); // Link the code of methods skipped by LinkCode. for (size_t method_index = 0; it.HasNextDirectMethod(); ++method_index, it.Next()) { ArtMethod* method = klass->GetDirectMethod(method_index, image_pointer_size_); if (!method->IsStatic()) { // Only update static methods. continue; } const void* quick_code = nullptr; if (has_oat_class) { OatFile::OatMethod oat_method = oat_class.GetOatMethod(method_index); quick_code = oat_method.GetQuickCode(); } const bool enter_interpreter = NeedsInterpreter(method, quick_code); if (enter_interpreter) { // Use interpreter entry point. // Check whether the method is native, in which case it's generic JNI. if (quick_code == nullptr && method->IsNative()) { quick_code = GetQuickGenericJniStub(); } else { quick_code = GetQuickToInterpreterBridge(); } } runtime->GetInstrumentation()->UpdateMethodsCode(method, quick_code); } // Ignore virtual methods on the iterator. } void ClassLinker::LinkCode(ArtMethod* method, const OatFile::OatClass* oat_class, uint32_t class_def_method_index) { Runtime* const runtime = Runtime::Current(); if (runtime->IsAotCompiler()) { // The following code only applies to a non-compiler runtime. return; } // Method shouldn't have already been linked. DCHECK(method->GetEntryPointFromQuickCompiledCode() == nullptr); if (oat_class != nullptr) { // Every kind of method should at least get an invoke stub from the oat_method. // non-abstract methods also get their code pointers. const OatFile::OatMethod oat_method = oat_class->GetOatMethod(class_def_method_index); oat_method.LinkMethod(method); } // Install entry point from interpreter. bool enter_interpreter = NeedsInterpreter(method, method->GetEntryPointFromQuickCompiledCode()); if (enter_interpreter && !method->IsNative()) { method->SetEntryPointFromInterpreter(artInterpreterToInterpreterBridge); } else { method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); } if (method->IsAbstract()) { method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); return; } if (method->IsStatic() && !method->IsConstructor()) { // For static methods excluding the class initializer, install the trampoline. // It will be replaced by the proper entry point by ClassLinker::FixupStaticTrampolines // after initializing class (see ClassLinker::InitializeClass method). method->SetEntryPointFromQuickCompiledCode(GetQuickResolutionStub()); } else if (enter_interpreter) { if (!method->IsNative()) { // Set entry point from compiled code if there's no code or in interpreter only mode. method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); } else { method->SetEntryPointFromQuickCompiledCode(GetQuickGenericJniStub()); } } if (method->IsNative()) { // Unregistering restores the dlsym lookup stub. method->UnregisterNative(); if (enter_interpreter) { // We have a native method here without code. Then it should have either the generic JNI // trampoline as entrypoint (non-static), or the resolution trampoline (static). // TODO: this doesn't handle all the cases where trampolines may be installed. const void* entry_point = method->GetEntryPointFromQuickCompiledCode(); DCHECK(IsQuickGenericJniStub(entry_point) || IsQuickResolutionStub(entry_point)); } } } void ClassLinker::SetupClass(const DexFile& dex_file, const DexFile::ClassDef& dex_class_def, Handle klass, mirror::ClassLoader* class_loader) { CHECK(klass.Get() != nullptr); CHECK(klass->GetDexCache() != nullptr); CHECK_EQ(mirror::Class::kStatusNotReady, klass->GetStatus()); const char* descriptor = dex_file.GetClassDescriptor(dex_class_def); CHECK(descriptor != nullptr); klass->SetClass(GetClassRoot(kJavaLangClass)); uint32_t access_flags = dex_class_def.GetJavaAccessFlags(); CHECK_EQ(access_flags & ~kAccJavaFlagsMask, 0U); klass->SetAccessFlags(access_flags); klass->SetClassLoader(class_loader); DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot); mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, nullptr); klass->SetDexClassDefIndex(dex_file.GetIndexForClassDef(dex_class_def)); klass->SetDexTypeIndex(dex_class_def.class_idx_); CHECK(klass->GetDexCacheStrings() != nullptr); } void ClassLinker::LoadClass(Thread* self, const DexFile& dex_file, const DexFile::ClassDef& dex_class_def, Handle klass) { const uint8_t* class_data = dex_file.GetClassData(dex_class_def); if (class_data == nullptr) { return; // no fields or methods - for example a marker interface } bool has_oat_class = false; if (Runtime::Current()->IsStarted() && !Runtime::Current()->IsAotCompiler()) { OatFile::OatClass oat_class = FindOatClass(dex_file, klass->GetDexClassDefIndex(), &has_oat_class); if (has_oat_class) { LoadClassMembers(self, dex_file, class_data, klass, &oat_class); } } if (!has_oat_class) { LoadClassMembers(self, dex_file, class_data, klass, nullptr); } } ArtField* ClassLinker::AllocArtFieldArray(Thread* self, size_t length) { auto* const la = Runtime::Current()->GetLinearAlloc(); auto* ptr = reinterpret_cast(la->AllocArray(self, length)); CHECK(ptr!= nullptr); std::uninitialized_fill_n(ptr, length, ArtField()); return ptr; } ArtMethod* ClassLinker::AllocArtMethodArray(Thread* self, size_t length) { const size_t method_size = ArtMethod::ObjectSize(image_pointer_size_); uintptr_t ptr = reinterpret_cast( Runtime::Current()->GetLinearAlloc()->Alloc(self, method_size * length)); CHECK_NE(ptr, 0u); for (size_t i = 0; i < length; ++i) { new(reinterpret_cast(ptr + i * method_size)) ArtMethod; } return reinterpret_cast(ptr); } void ClassLinker::LoadClassMembers(Thread* self, const DexFile& dex_file, const uint8_t* class_data, Handle klass, const OatFile::OatClass* oat_class) { { // Note: We cannot have thread suspension until the field and method arrays are setup or else // Class::VisitFieldRoots may miss some fields or methods. ScopedAssertNoThreadSuspension nts(self, __FUNCTION__); // Load static fields. ClassDataItemIterator it(dex_file, class_data); const size_t num_sfields = it.NumStaticFields(); ArtField* sfields = num_sfields != 0 ? AllocArtFieldArray(self, num_sfields) : nullptr; for (size_t i = 0; it.HasNextStaticField(); i++, it.Next()) { CHECK_LT(i, num_sfields); LoadField(it, klass, &sfields[i]); } klass->SetSFields(sfields); klass->SetNumStaticFields(num_sfields); DCHECK_EQ(klass->NumStaticFields(), num_sfields); // Load instance fields. const size_t num_ifields = it.NumInstanceFields(); ArtField* ifields = num_ifields != 0 ? AllocArtFieldArray(self, num_ifields) : nullptr; for (size_t i = 0; it.HasNextInstanceField(); i++, it.Next()) { CHECK_LT(i, num_ifields); LoadField(it, klass, &ifields[i]); } klass->SetIFields(ifields); klass->SetNumInstanceFields(num_ifields); DCHECK_EQ(klass->NumInstanceFields(), num_ifields); // Load methods. if (it.NumDirectMethods() != 0) { klass->SetDirectMethodsPtr(AllocArtMethodArray(self, it.NumDirectMethods())); } klass->SetNumDirectMethods(it.NumDirectMethods()); if (it.NumVirtualMethods() != 0) { klass->SetVirtualMethodsPtr(AllocArtMethodArray(self, it.NumVirtualMethods())); } klass->SetNumVirtualMethods(it.NumVirtualMethods()); size_t class_def_method_index = 0; uint32_t last_dex_method_index = DexFile::kDexNoIndex; size_t last_class_def_method_index = 0; for (size_t i = 0; it.HasNextDirectMethod(); i++, it.Next()) { ArtMethod* method = klass->GetDirectMethodUnchecked(i, image_pointer_size_); LoadMethod(self, dex_file, it, klass, method); LinkCode(method, oat_class, class_def_method_index); uint32_t it_method_index = it.GetMemberIndex(); if (last_dex_method_index == it_method_index) { // duplicate case method->SetMethodIndex(last_class_def_method_index); } else { method->SetMethodIndex(class_def_method_index); last_dex_method_index = it_method_index; last_class_def_method_index = class_def_method_index; } class_def_method_index++; } for (size_t i = 0; it.HasNextVirtualMethod(); i++, it.Next()) { ArtMethod* method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); LoadMethod(self, dex_file, it, klass, method); DCHECK_EQ(class_def_method_index, it.NumDirectMethods() + i); LinkCode(method, oat_class, class_def_method_index); class_def_method_index++; } DCHECK(!it.HasNext()); } self->AllowThreadSuspension(); } void ClassLinker::LoadField(const ClassDataItemIterator& it, Handle klass, ArtField* dst) { const uint32_t field_idx = it.GetMemberIndex(); dst->SetDexFieldIndex(field_idx); dst->SetDeclaringClass(klass.Get()); dst->SetAccessFlags(it.GetFieldAccessFlags()); } void ClassLinker::LoadMethod(Thread* self, const DexFile& dex_file, const ClassDataItemIterator& it, Handle klass, ArtMethod* dst) { uint32_t dex_method_idx = it.GetMemberIndex(); const DexFile::MethodId& method_id = dex_file.GetMethodId(dex_method_idx); const char* method_name = dex_file.StringDataByIdx(method_id.name_idx_); ScopedAssertNoThreadSuspension ants(self, "LoadMethod"); dst->SetDexMethodIndex(dex_method_idx); dst->SetDeclaringClass(klass.Get()); dst->SetCodeItemOffset(it.GetMethodCodeItemOffset()); dst->SetDexCacheResolvedMethods(klass->GetDexCache()->GetResolvedMethods()); dst->SetDexCacheResolvedTypes(klass->GetDexCache()->GetResolvedTypes()); uint32_t access_flags = it.GetMethodAccessFlags(); if (UNLIKELY(strcmp("finalize", method_name) == 0)) { // Set finalizable flag on declaring class. if (strcmp("V", dex_file.GetShorty(method_id.proto_idx_)) == 0) { // Void return type. if (klass->GetClassLoader() != nullptr) { // All non-boot finalizer methods are flagged. klass->SetFinalizable(); } else { std::string temp; const char* klass_descriptor = klass->GetDescriptor(&temp); // The Enum class declares a "final" finalize() method to prevent subclasses from // introducing a finalizer. We don't want to set the finalizable flag for Enum or its // subclasses, so we exclude it here. // We also want to avoid setting the flag on Object, where we know that finalize() is // empty. if (strcmp(klass_descriptor, "Ljava/lang/Object;") != 0 && strcmp(klass_descriptor, "Ljava/lang/Enum;") != 0) { klass->SetFinalizable(); } } } } else if (method_name[0] == '<') { // Fix broken access flags for initializers. Bug 11157540. bool is_init = (strcmp("", method_name) == 0); bool is_clinit = !is_init && (strcmp("", method_name) == 0); if (UNLIKELY(!is_init && !is_clinit)) { LOG(WARNING) << "Unexpected '<' at start of method name " << method_name; } else { if (UNLIKELY((access_flags & kAccConstructor) == 0)) { LOG(WARNING) << method_name << " didn't have expected constructor access flag in class " << PrettyDescriptor(klass.Get()) << " in dex file " << dex_file.GetLocation(); access_flags |= kAccConstructor; } } } dst->SetAccessFlags(access_flags); } void ClassLinker::AppendToBootClassPath(Thread* self, const DexFile& dex_file) { StackHandleScope<1> hs(self); Handle dex_cache(hs.NewHandle(AllocDexCache(self, dex_file))); CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for " << dex_file.GetLocation(); AppendToBootClassPath(dex_file, dex_cache); } void ClassLinker::AppendToBootClassPath(const DexFile& dex_file, Handle dex_cache) { CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation(); boot_class_path_.push_back(&dex_file); RegisterDexFile(dex_file, dex_cache); } bool ClassLinker::IsDexFileRegisteredLocked(const DexFile& dex_file) { dex_lock_.AssertSharedHeld(Thread::Current()); for (size_t i = 0; i != dex_caches_.size(); ++i) { mirror::DexCache* dex_cache = GetDexCache(i); if (dex_cache->GetDexFile() == &dex_file) { return true; } } return false; } bool ClassLinker::IsDexFileRegistered(const DexFile& dex_file) { ReaderMutexLock mu(Thread::Current(), dex_lock_); return IsDexFileRegisteredLocked(dex_file); } void ClassLinker::RegisterDexFileLocked(const DexFile& dex_file, Handle dex_cache) { dex_lock_.AssertExclusiveHeld(Thread::Current()); CHECK(dex_cache.Get() != nullptr) << dex_file.GetLocation(); CHECK(dex_cache->GetLocation()->Equals(dex_file.GetLocation())) << dex_cache->GetLocation()->ToModifiedUtf8() << " " << dex_file.GetLocation(); dex_caches_.push_back(GcRoot(dex_cache.Get())); dex_cache->SetDexFile(&dex_file); if (log_new_dex_caches_roots_) { // TODO: This is not safe if we can remove dex caches. new_dex_cache_roots_.push_back(dex_caches_.size() - 1); } } void ClassLinker::RegisterDexFile(const DexFile& dex_file) { Thread* self = Thread::Current(); { ReaderMutexLock mu(self, dex_lock_); if (IsDexFileRegisteredLocked(dex_file)) { return; } } // Don't alloc while holding the lock, since allocation may need to // suspend all threads and another thread may need the dex_lock_ to // get to a suspend point. StackHandleScope<1> hs(self); Handle dex_cache(hs.NewHandle(AllocDexCache(self, dex_file))); CHECK(dex_cache.Get() != nullptr) << "Failed to allocate dex cache for " << dex_file.GetLocation(); { WriterMutexLock mu(self, dex_lock_); if (IsDexFileRegisteredLocked(dex_file)) { return; } RegisterDexFileLocked(dex_file, dex_cache); } } void ClassLinker::RegisterDexFile(const DexFile& dex_file, Handle dex_cache) { WriterMutexLock mu(Thread::Current(), dex_lock_); RegisterDexFileLocked(dex_file, dex_cache); } mirror::DexCache* ClassLinker::FindDexCache(const DexFile& dex_file) { ReaderMutexLock mu(Thread::Current(), dex_lock_); // Search assuming unique-ness of dex file. for (size_t i = 0; i != dex_caches_.size(); ++i) { mirror::DexCache* dex_cache = GetDexCache(i); if (dex_cache->GetDexFile() == &dex_file) { return dex_cache; } } // Search matching by location name. std::string location(dex_file.GetLocation()); for (size_t i = 0; i != dex_caches_.size(); ++i) { mirror::DexCache* dex_cache = GetDexCache(i); if (dex_cache->GetDexFile()->GetLocation() == location) { return dex_cache; } } // Failure, dump diagnostic and abort. for (size_t i = 0; i != dex_caches_.size(); ++i) { mirror::DexCache* dex_cache = GetDexCache(i); LOG(ERROR) << "Registered dex file " << i << " = " << dex_cache->GetDexFile()->GetLocation(); } LOG(FATAL) << "Failed to find DexCache for DexFile " << location; UNREACHABLE(); } void ClassLinker::FixupDexCaches(ArtMethod* resolution_method) { ReaderMutexLock mu(Thread::Current(), dex_lock_); for (auto& dex_cache : dex_caches_) { dex_cache.Read()->Fixup(resolution_method, image_pointer_size_); } } mirror::Class* ClassLinker::CreatePrimitiveClass(Thread* self, Primitive::Type type) { mirror::Class* klass = AllocClass(self, mirror::Class::PrimitiveClassSize(image_pointer_size_)); if (UNLIKELY(klass == nullptr)) { self->AssertPendingOOMException(); return nullptr; } return InitializePrimitiveClass(klass, type); } mirror::Class* ClassLinker::InitializePrimitiveClass(mirror::Class* primitive_class, Primitive::Type type) { CHECK(primitive_class != nullptr); // Must hold lock on object when initializing. Thread* self = Thread::Current(); StackHandleScope<1> hs(self); Handle h_class(hs.NewHandle(primitive_class)); ObjectLock lock(self, h_class); h_class->SetAccessFlags(kAccPublic | kAccFinal | kAccAbstract); h_class->SetPrimitiveType(type); mirror::Class::SetStatus(h_class, mirror::Class::kStatusInitialized, self); const char* descriptor = Primitive::Descriptor(type); mirror::Class* existing = InsertClass(descriptor, h_class.Get(), ComputeModifiedUtf8Hash(descriptor)); CHECK(existing == nullptr) << "InitPrimitiveClass(" << type << ") failed"; return h_class.Get(); } // Create an array class (i.e. the class object for the array, not the // array itself). "descriptor" looks like "[C" or "[[[[B" or // "[Ljava/lang/String;". // // If "descriptor" refers to an array of primitives, look up the // primitive type's internally-generated class object. // // "class_loader" is the class loader of the class that's referring to // us. It's used to ensure that we're looking for the element type in // the right context. It does NOT become the class loader for the // array class; that always comes from the base element class. // // Returns null with an exception raised on failure. mirror::Class* ClassLinker::CreateArrayClass(Thread* self, const char* descriptor, size_t hash, Handle class_loader) { // Identify the underlying component type CHECK_EQ('[', descriptor[0]); StackHandleScope<2> hs(self); MutableHandle component_type(hs.NewHandle(FindClass(self, descriptor + 1, class_loader))); if (component_type.Get() == nullptr) { DCHECK(self->IsExceptionPending()); // We need to accept erroneous classes as component types. const size_t component_hash = ComputeModifiedUtf8Hash(descriptor + 1); component_type.Assign(LookupClass(self, descriptor + 1, component_hash, class_loader.Get())); if (component_type.Get() == nullptr) { DCHECK(self->IsExceptionPending()); return nullptr; } else { self->ClearException(); } } if (UNLIKELY(component_type->IsPrimitiveVoid())) { ThrowNoClassDefFoundError("Attempt to create array of void primitive type"); return nullptr; } // See if the component type is already loaded. Array classes are // always associated with the class loader of their underlying // element type -- an array of Strings goes with the loader for // java/lang/String -- so we need to look for it there. (The // caller should have checked for the existence of the class // before calling here, but they did so with *their* class loader, // not the component type's loader.) // // If we find it, the caller adds "loader" to the class' initiating // loader list, which should prevent us from going through this again. // // This call is unnecessary if "loader" and "component_type->GetClassLoader()" // are the same, because our caller (FindClass) just did the // lookup. (Even if we get this wrong we still have correct behavior, // because we effectively do this lookup again when we add the new // class to the hash table --- necessary because of possible races with // other threads.) if (class_loader.Get() != component_type->GetClassLoader()) { mirror::Class* new_class = LookupClass(self, descriptor, hash, component_type->GetClassLoader()); if (new_class != nullptr) { return new_class; } } // Fill out the fields in the Class. // // It is possible to execute some methods against arrays, because // all arrays are subclasses of java_lang_Object_, so we need to set // up a vtable. We can just point at the one in java_lang_Object_. // // Array classes are simple enough that we don't need to do a full // link step. auto new_class = hs.NewHandle(nullptr); if (UNLIKELY(!init_done_)) { // Classes that were hand created, ie not by FindSystemClass if (strcmp(descriptor, "[Ljava/lang/Class;") == 0) { new_class.Assign(GetClassRoot(kClassArrayClass)); } else if (strcmp(descriptor, "[Ljava/lang/Object;") == 0) { new_class.Assign(GetClassRoot(kObjectArrayClass)); } else if (strcmp(descriptor, GetClassRootDescriptor(kJavaLangStringArrayClass)) == 0) { new_class.Assign(GetClassRoot(kJavaLangStringArrayClass)); } else if (strcmp(descriptor, "[C") == 0) { new_class.Assign(GetClassRoot(kCharArrayClass)); } else if (strcmp(descriptor, "[I") == 0) { new_class.Assign(GetClassRoot(kIntArrayClass)); } else if (strcmp(descriptor, "[J") == 0) { new_class.Assign(GetClassRoot(kLongArrayClass)); } } if (new_class.Get() == nullptr) { new_class.Assign(AllocClass(self, mirror::Array::ClassSize(image_pointer_size_))); if (new_class.Get() == nullptr) { self->AssertPendingOOMException(); return nullptr; } new_class->SetComponentType(component_type.Get()); } ObjectLock lock(self, new_class); // Must hold lock on object when initializing. DCHECK(new_class->GetComponentType() != nullptr); mirror::Class* java_lang_Object = GetClassRoot(kJavaLangObject); new_class->SetSuperClass(java_lang_Object); new_class->SetVTable(java_lang_Object->GetVTable()); new_class->SetPrimitiveType(Primitive::kPrimNot); new_class->SetClassLoader(component_type->GetClassLoader()); mirror::Class::SetStatus(new_class, mirror::Class::kStatusLoaded, self); { ArtMethod* imt[mirror::Class::kImtSize]; std::fill_n(imt, arraysize(imt), Runtime::Current()->GetImtUnimplementedMethod()); new_class->PopulateEmbeddedImtAndVTable(imt, image_pointer_size_); } mirror::Class::SetStatus(new_class, mirror::Class::kStatusInitialized, self); // don't need to set new_class->SetObjectSize(..) // because Object::SizeOf delegates to Array::SizeOf // All arrays have java/lang/Cloneable and java/io/Serializable as // interfaces. We need to set that up here, so that stuff like // "instanceof" works right. // // Note: The GC could run during the call to FindSystemClass, // so we need to make sure the class object is GC-valid while we're in // there. Do this by clearing the interface list so the GC will just // think that the entries are null. // Use the single, global copies of "interfaces" and "iftable" // (remember not to free them for arrays). { mirror::IfTable* array_iftable = array_iftable_.Read(); CHECK(array_iftable != nullptr); new_class->SetIfTable(array_iftable); } // Inherit access flags from the component type. int access_flags = new_class->GetComponentType()->GetAccessFlags(); // Lose any implementation detail flags; in particular, arrays aren't finalizable. access_flags &= kAccJavaFlagsMask; // Arrays can't be used as a superclass or interface, so we want to add "abstract final" // and remove "interface". access_flags |= kAccAbstract | kAccFinal; access_flags &= ~kAccInterface; new_class->SetAccessFlags(access_flags); mirror::Class* existing = InsertClass(descriptor, new_class.Get(), hash); if (existing == nullptr) { return new_class.Get(); } // Another thread must have loaded the class after we // started but before we finished. Abandon what we've // done. // // (Yes, this happens.) return existing; } mirror::Class* ClassLinker::FindPrimitiveClass(char type) { switch (type) { case 'B': return GetClassRoot(kPrimitiveByte); case 'C': return GetClassRoot(kPrimitiveChar); case 'D': return GetClassRoot(kPrimitiveDouble); case 'F': return GetClassRoot(kPrimitiveFloat); case 'I': return GetClassRoot(kPrimitiveInt); case 'J': return GetClassRoot(kPrimitiveLong); case 'S': return GetClassRoot(kPrimitiveShort); case 'Z': return GetClassRoot(kPrimitiveBoolean); case 'V': return GetClassRoot(kPrimitiveVoid); default: break; } std::string printable_type(PrintableChar(type)); ThrowNoClassDefFoundError("Not a primitive type: %s", printable_type.c_str()); return nullptr; } mirror::Class* ClassLinker::InsertClass(const char* descriptor, mirror::Class* klass, size_t hash) { if (VLOG_IS_ON(class_linker)) { mirror::DexCache* dex_cache = klass->GetDexCache(); std::string source; if (dex_cache != nullptr) { source += " from "; source += dex_cache->GetLocation()->ToModifiedUtf8(); } LOG(INFO) << "Loaded class " << descriptor << source; } WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); mirror::Class* existing = LookupClassFromTableLocked(descriptor, klass->GetClassLoader(), hash); if (existing != nullptr) { return existing; } if (kIsDebugBuild && !klass->IsTemp() && klass->GetClassLoader() == nullptr && dex_cache_image_class_lookup_required_) { // Check a class loaded with the system class loader matches one in the image if the class // is in the image. existing = LookupClassFromImage(descriptor); if (existing != nullptr) { CHECK_EQ(klass, existing); } } VerifyObject(klass); class_table_.InsertWithHash(GcRoot(klass), hash); if (log_new_class_table_roots_) { new_class_roots_.push_back(GcRoot(klass)); } return nullptr; } void ClassLinker::UpdateClassVirtualMethods(mirror::Class* klass, ArtMethod* new_methods, size_t new_num_methods) { // classlinker_classes_lock_ is used to guard against races between root marking and changing the // direct and virtual method pointers. WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); klass->SetNumVirtualMethods(new_num_methods); klass->SetVirtualMethodsPtr(new_methods); if (log_new_class_table_roots_) { new_class_roots_.push_back(GcRoot(klass)); } } mirror::Class* ClassLinker::UpdateClass(const char* descriptor, mirror::Class* klass, size_t hash) { WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); auto existing_it = class_table_.FindWithHash(std::make_pair(descriptor, klass->GetClassLoader()), hash); CHECK(existing_it != class_table_.end()); mirror::Class* existing = existing_it->Read(); CHECK_NE(existing, klass) << descriptor; CHECK(!existing->IsResolved()) << descriptor; CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusResolving) << descriptor; CHECK(!klass->IsTemp()) << descriptor; if (kIsDebugBuild && klass->GetClassLoader() == nullptr && dex_cache_image_class_lookup_required_) { // Check a class loaded with the system class loader matches one in the image if the class // is in the image. existing = LookupClassFromImage(descriptor); if (existing != nullptr) { CHECK_EQ(klass, existing) << descriptor; } } VerifyObject(klass); // Update the element in the hash set. *existing_it = GcRoot(klass); if (log_new_class_table_roots_) { new_class_roots_.push_back(GcRoot(klass)); } return existing; } bool ClassLinker::RemoveClass(const char* descriptor, mirror::ClassLoader* class_loader) { WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); auto pair = std::make_pair(descriptor, class_loader); auto it = class_table_.Find(pair); if (it != class_table_.end()) { class_table_.Erase(it); return true; } it = pre_zygote_class_table_.Find(pair); if (it != pre_zygote_class_table_.end()) { pre_zygote_class_table_.Erase(it); return true; } return false; } mirror::Class* ClassLinker::LookupClass(Thread* self, const char* descriptor, size_t hash, mirror::ClassLoader* class_loader) { { ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); mirror::Class* result = LookupClassFromTableLocked(descriptor, class_loader, hash); if (result != nullptr) { return result; } } if (class_loader != nullptr || !dex_cache_image_class_lookup_required_) { return nullptr; } else { // Lookup failed but need to search dex_caches_. mirror::Class* result = LookupClassFromImage(descriptor); if (result != nullptr) { InsertClass(descriptor, result, hash); } else { // Searching the image dex files/caches failed, we don't want to get into this situation // often as map searches are faster, so after kMaxFailedDexCacheLookups move all image // classes into the class table. constexpr uint32_t kMaxFailedDexCacheLookups = 1000; if (++failed_dex_cache_class_lookups_ > kMaxFailedDexCacheLookups) { MoveImageClassesToClassTable(); } } return result; } } mirror::Class* ClassLinker::LookupClassFromTableLocked(const char* descriptor, mirror::ClassLoader* class_loader, size_t hash) { auto descriptor_pair = std::make_pair(descriptor, class_loader); auto it = pre_zygote_class_table_.FindWithHash(descriptor_pair, hash); if (it == pre_zygote_class_table_.end()) { it = class_table_.FindWithHash(descriptor_pair, hash); if (it == class_table_.end()) { return nullptr; } } return it->Read(); } static mirror::ObjectArray* GetImageDexCaches() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { gc::space::ImageSpace* image = Runtime::Current()->GetHeap()->GetImageSpace(); CHECK(image != nullptr); mirror::Object* root = image->GetImageHeader().GetImageRoot(ImageHeader::kDexCaches); return root->AsObjectArray(); } void ClassLinker::MoveImageClassesToClassTable() { Thread* self = Thread::Current(); WriterMutexLock mu(self, *Locks::classlinker_classes_lock_); if (!dex_cache_image_class_lookup_required_) { return; // All dex cache classes are already in the class table. } ScopedAssertNoThreadSuspension ants(self, "Moving image classes to class table"); mirror::ObjectArray* dex_caches = GetImageDexCaches(); std::string temp; for (int32_t i = 0; i < dex_caches->GetLength(); i++) { mirror::DexCache* dex_cache = dex_caches->Get(i); mirror::ObjectArray* types = dex_cache->GetResolvedTypes(); for (int32_t j = 0; j < types->GetLength(); j++) { mirror::Class* klass = types->Get(j); if (klass != nullptr) { DCHECK(klass->GetClassLoader() == nullptr); const char* descriptor = klass->GetDescriptor(&temp); size_t hash = ComputeModifiedUtf8Hash(descriptor); mirror::Class* existing = LookupClassFromTableLocked(descriptor, nullptr, hash); if (existing != nullptr) { CHECK_EQ(existing, klass) << PrettyClassAndClassLoader(existing) << " != " << PrettyClassAndClassLoader(klass); } else { class_table_.Insert(GcRoot(klass)); if (log_new_class_table_roots_) { new_class_roots_.push_back(GcRoot(klass)); } } } } } dex_cache_image_class_lookup_required_ = false; } void ClassLinker::MoveClassTableToPreZygote() { WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); DCHECK(pre_zygote_class_table_.Empty()); pre_zygote_class_table_ = std::move(class_table_); class_table_.Clear(); } mirror::Class* ClassLinker::LookupClassFromImage(const char* descriptor) { ScopedAssertNoThreadSuspension ants(Thread::Current(), "Image class lookup"); mirror::ObjectArray* dex_caches = GetImageDexCaches(); for (int32_t i = 0; i < dex_caches->GetLength(); ++i) { mirror::DexCache* dex_cache = dex_caches->Get(i); const DexFile* dex_file = dex_cache->GetDexFile(); // Try binary searching the string/type index. const DexFile::StringId* string_id = dex_file->FindStringId(descriptor); if (string_id != nullptr) { const DexFile::TypeId* type_id = dex_file->FindTypeId(dex_file->GetIndexForStringId(*string_id)); if (type_id != nullptr) { uint16_t type_idx = dex_file->GetIndexForTypeId(*type_id); mirror::Class* klass = dex_cache->GetResolvedType(type_idx); if (klass != nullptr) { return klass; } } } } return nullptr; } void ClassLinker::LookupClasses(const char* descriptor, std::vector& result) { result.clear(); if (dex_cache_image_class_lookup_required_) { MoveImageClassesToClassTable(); } WriterMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); while (true) { auto it = class_table_.Find(descriptor); if (it == class_table_.end()) { break; } result.push_back(it->Read()); class_table_.Erase(it); } for (mirror::Class* k : result) { class_table_.Insert(GcRoot(k)); } size_t pre_zygote_start = result.size(); // Now handle the pre zygote table. // Note: This dirties the pre-zygote table but shouldn't be an issue since LookupClasses is only // called from the debugger. while (true) { auto it = pre_zygote_class_table_.Find(descriptor); if (it == pre_zygote_class_table_.end()) { break; } result.push_back(it->Read()); pre_zygote_class_table_.Erase(it); } for (size_t i = pre_zygote_start; i < result.size(); ++i) { pre_zygote_class_table_.Insert(GcRoot(result[i])); } } void ClassLinker::VerifyClass(Thread* self, Handle klass) { // TODO: assert that the monitor on the Class is held ObjectLock lock(self, klass); // Don't attempt to re-verify if already sufficiently verified. if (klass->IsVerified()) { EnsurePreverifiedMethods(klass); return; } if (klass->IsCompileTimeVerified() && Runtime::Current()->IsAotCompiler()) { return; } // The class might already be erroneous, for example at compile time if we attempted to verify // this class as a parent to another. if (klass->IsErroneous()) { ThrowEarlierClassFailure(klass.Get()); return; } if (klass->GetStatus() == mirror::Class::kStatusResolved) { mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifying, self); } else { CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime) << PrettyClass(klass.Get()); CHECK(!Runtime::Current()->IsAotCompiler()); mirror::Class::SetStatus(klass, mirror::Class::kStatusVerifyingAtRuntime, self); } // Skip verification if disabled. if (!Runtime::Current()->IsVerificationEnabled()) { mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); EnsurePreverifiedMethods(klass); return; } // Verify super class. StackHandleScope<2> hs(self); Handle super(hs.NewHandle(klass->GetSuperClass())); if (super.Get() != nullptr) { // Acquire lock to prevent races on verifying the super class. ObjectLock super_lock(self, super); if (!super->IsVerified() && !super->IsErroneous()) { VerifyClass(self, super); } if (!super->IsCompileTimeVerified()) { std::string error_msg( StringPrintf("Rejecting class %s that attempts to sub-class erroneous class %s", PrettyDescriptor(klass.Get()).c_str(), PrettyDescriptor(super.Get()).c_str())); LOG(WARNING) << error_msg << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); Handle cause(hs.NewHandle(self->GetException())); if (cause.Get() != nullptr) { self->ClearException(); } ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); if (cause.Get() != nullptr) { self->GetException()->SetCause(cause.Get()); } ClassReference ref(klass->GetDexCache()->GetDexFile(), klass->GetDexClassDefIndex()); if (Runtime::Current()->IsAotCompiler()) { Runtime::Current()->GetCompilerCallbacks()->ClassRejected(ref); } mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); return; } } // Try to use verification information from the oat file, otherwise do runtime verification. const DexFile& dex_file = *klass->GetDexCache()->GetDexFile(); mirror::Class::Status oat_file_class_status(mirror::Class::kStatusNotReady); bool preverified = VerifyClassUsingOatFile(dex_file, klass.Get(), oat_file_class_status); if (oat_file_class_status == mirror::Class::kStatusError) { VLOG(class_linker) << "Skipping runtime verification of erroneous class " << PrettyDescriptor(klass.Get()) << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8(); ThrowVerifyError(klass.Get(), "Rejecting class %s because it failed compile-time verification", PrettyDescriptor(klass.Get()).c_str()); mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); return; } verifier::MethodVerifier::FailureKind verifier_failure = verifier::MethodVerifier::kNoFailure; std::string error_msg; if (!preverified) { verifier_failure = verifier::MethodVerifier::VerifyClass(self, klass.Get(), Runtime::Current()->IsAotCompiler(), &error_msg); } if (preverified || verifier_failure != verifier::MethodVerifier::kHardFailure) { if (!preverified && verifier_failure != verifier::MethodVerifier::kNoFailure) { VLOG(class_linker) << "Soft verification failure in class " << PrettyDescriptor(klass.Get()) << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() << " because: " << error_msg; } self->AssertNoPendingException(); // Make sure all classes referenced by catch blocks are resolved. ResolveClassExceptionHandlerTypes(dex_file, klass); if (verifier_failure == verifier::MethodVerifier::kNoFailure) { // Even though there were no verifier failures we need to respect whether the super-class // was verified or requiring runtime reverification. if (super.Get() == nullptr || super->IsVerified()) { mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); } else { CHECK_EQ(super->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); // Pretend a soft failure occured so that we don't consider the class verified below. verifier_failure = verifier::MethodVerifier::kSoftFailure; } } else { CHECK_EQ(verifier_failure, verifier::MethodVerifier::kSoftFailure); // Soft failures at compile time should be retried at runtime. Soft // failures at runtime will be handled by slow paths in the generated // code. Set status accordingly. if (Runtime::Current()->IsAotCompiler()) { mirror::Class::SetStatus(klass, mirror::Class::kStatusRetryVerificationAtRuntime, self); } else { mirror::Class::SetStatus(klass, mirror::Class::kStatusVerified, self); // As this is a fake verified status, make sure the methods are _not_ marked preverified // later. klass->SetPreverified(); } } } else { LOG(WARNING) << "Verification failed on class " << PrettyDescriptor(klass.Get()) << " in " << klass->GetDexCache()->GetLocation()->ToModifiedUtf8() << " because: " << error_msg; self->AssertNoPendingException(); ThrowVerifyError(klass.Get(), "%s", error_msg.c_str()); mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); } if (preverified || verifier_failure == verifier::MethodVerifier::kNoFailure) { // Class is verified so we don't need to do any access check on its methods. // Let the interpreter know it by setting the kAccPreverified flag onto each // method. // Note: we're going here during compilation and at runtime. When we set the // kAccPreverified flag when compiling image classes, the flag is recorded // in the image and is set when loading the image. EnsurePreverifiedMethods(klass); } } void ClassLinker::EnsurePreverifiedMethods(Handle klass) { if (!klass->IsPreverified()) { klass->SetPreverifiedFlagOnAllMethods(image_pointer_size_); klass->SetPreverified(); } } bool ClassLinker::VerifyClassUsingOatFile(const DexFile& dex_file, mirror::Class* klass, mirror::Class::Status& oat_file_class_status) { // If we're compiling, we can only verify the class using the oat file if // we are not compiling the image or if the class we're verifying is not part of // the app. In other words, we will only check for preverification of bootclasspath // classes. if (Runtime::Current()->IsAotCompiler()) { // Are we compiling the bootclasspath? if (Runtime::Current()->GetCompilerCallbacks()->IsBootImage()) { return false; } // We are compiling an app (not the image). // Is this an app class? (I.e. not a bootclasspath class) if (klass->GetClassLoader() != nullptr) { return false; } } const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); // In case we run without an image there won't be a backing oat file. if (oat_dex_file == nullptr) { return false; } // We may be running with a preopted oat file but without image. In this case, // we don't skip verification of preverified classes to ensure we initialize // dex caches with all types resolved during verification. // We need to trust image classes, as these might be coming out of a pre-opted, quickened boot // image (that we just failed loading), and the verifier can't be run on quickened opcodes when // the runtime isn't started. On the other hand, app classes can be re-verified even if they are // already pre-opted, as then the runtime is started. if (!Runtime::Current()->IsAotCompiler() && !Runtime::Current()->GetHeap()->HasImageSpace() && klass->GetClassLoader() != nullptr) { return false; } uint16_t class_def_index = klass->GetDexClassDefIndex(); oat_file_class_status = oat_dex_file->GetOatClass(class_def_index).GetStatus(); if (oat_file_class_status == mirror::Class::kStatusVerified || oat_file_class_status == mirror::Class::kStatusInitialized) { return true; } if (oat_file_class_status == mirror::Class::kStatusRetryVerificationAtRuntime) { // Compile time verification failed with a soft error. Compile time verification can fail // because we have incomplete type information. Consider the following: // class ... { // Foo x; // .... () { // if (...) { // v1 gets assigned a type of resolved class Foo // } else { // v1 gets assigned a type of unresolved class Bar // } // iput x = v1 // } } // when we merge v1 following the if-the-else it results in Conflict // (see verifier::RegType::Merge) as we can't know the type of Bar and we could possibly be // allowing an unsafe assignment to the field x in the iput (javac may have compiled this as // it knew Bar was a sub-class of Foo, but for us this may have been moved into a separate apk // at compile time). return false; } if (oat_file_class_status == mirror::Class::kStatusError) { // Compile time verification failed with a hard error. This is caused by invalid instructions // in the class. These errors are unrecoverable. return false; } if (oat_file_class_status == mirror::Class::kStatusNotReady) { // Status is uninitialized if we couldn't determine the status at compile time, for example, // not loading the class. // TODO: when the verifier doesn't rely on Class-es failing to resolve/load the type hierarchy // isn't a problem and this case shouldn't occur return false; } std::string temp; LOG(FATAL) << "Unexpected class status: " << oat_file_class_status << " " << dex_file.GetLocation() << " " << PrettyClass(klass) << " " << klass->GetDescriptor(&temp); UNREACHABLE(); } void ClassLinker::ResolveClassExceptionHandlerTypes(const DexFile& dex_file, Handle klass) { for (size_t i = 0; i < klass->NumDirectMethods(); i++) { ResolveMethodExceptionHandlerTypes(dex_file, klass->GetDirectMethod(i, image_pointer_size_)); } for (size_t i = 0; i < klass->NumVirtualMethods(); i++) { ResolveMethodExceptionHandlerTypes(dex_file, klass->GetVirtualMethod(i, image_pointer_size_)); } } void ClassLinker::ResolveMethodExceptionHandlerTypes(const DexFile& dex_file, ArtMethod* method) { // similar to DexVerifier::ScanTryCatchBlocks and dex2oat's ResolveExceptionsForMethod. const DexFile::CodeItem* code_item = dex_file.GetCodeItem(method->GetCodeItemOffset()); if (code_item == nullptr) { return; // native or abstract method } if (code_item->tries_size_ == 0) { return; // nothing to process } const uint8_t* handlers_ptr = DexFile::GetCatchHandlerData(*code_item, 0); uint32_t handlers_size = DecodeUnsignedLeb128(&handlers_ptr); ClassLinker* linker = Runtime::Current()->GetClassLinker(); for (uint32_t idx = 0; idx < handlers_size; idx++) { CatchHandlerIterator iterator(handlers_ptr); for (; iterator.HasNext(); iterator.Next()) { // Ensure exception types are resolved so that they don't need resolution to be delivered, // unresolved exception types will be ignored by exception delivery if (iterator.GetHandlerTypeIndex() != DexFile::kDexNoIndex16) { mirror::Class* exception_type = linker->ResolveType(iterator.GetHandlerTypeIndex(), method); if (exception_type == nullptr) { DCHECK(Thread::Current()->IsExceptionPending()); Thread::Current()->ClearException(); } } } handlers_ptr = iterator.EndDataPointer(); } } mirror::Class* ClassLinker::CreateProxyClass(ScopedObjectAccessAlreadyRunnable& soa, jstring name, jobjectArray interfaces, jobject loader, jobjectArray methods, jobjectArray throws) { Thread* self = soa.Self(); StackHandleScope<10> hs(self); MutableHandle klass(hs.NewHandle( AllocClass(self, GetClassRoot(kJavaLangClass), sizeof(mirror::Class)))); if (klass.Get() == nullptr) { CHECK(self->IsExceptionPending()); // OOME. return nullptr; } DCHECK(klass->GetClass() != nullptr); klass->SetObjectSize(sizeof(mirror::Proxy)); // Set the class access flags incl. preverified, so we do not try to set the flag on the methods. klass->SetAccessFlags(kAccClassIsProxy | kAccPublic | kAccFinal | kAccPreverified); klass->SetClassLoader(soa.Decode(loader)); DCHECK_EQ(klass->GetPrimitiveType(), Primitive::kPrimNot); klass->SetName(soa.Decode(name)); klass->SetDexCache(GetClassRoot(kJavaLangReflectProxy)->GetDexCache()); mirror::Class::SetStatus(klass, mirror::Class::kStatusIdx, self); std::string descriptor(GetDescriptorForProxy(klass.Get())); size_t hash = ComputeModifiedUtf8Hash(descriptor.c_str()); // Insert the class before loading the fields as the field roots // (ArtField::declaring_class_) are only visited from the class // table. There can't be any suspend points between inserting the // class and setting the field arrays below. mirror::Class* existing = InsertClass(descriptor.c_str(), klass.Get(), hash); CHECK(existing == nullptr); // Instance fields are inherited, but we add a couple of static fields... const size_t num_fields = 2; ArtField* sfields = AllocArtFieldArray(self, num_fields); klass->SetSFields(sfields); klass->SetNumStaticFields(num_fields); // 1. Create a static field 'interfaces' that holds the _declared_ interfaces implemented by // our proxy, so Class.getInterfaces doesn't return the flattened set. ArtField* interfaces_sfield = &sfields[0]; interfaces_sfield->SetDexFieldIndex(0); interfaces_sfield->SetDeclaringClass(klass.Get()); interfaces_sfield->SetAccessFlags(kAccStatic | kAccPublic | kAccFinal); // 2. Create a static field 'throws' that holds exceptions thrown by our methods. ArtField* throws_sfield = &sfields[1]; throws_sfield->SetDexFieldIndex(1); throws_sfield->SetDeclaringClass(klass.Get()); throws_sfield->SetAccessFlags(kAccStatic | kAccPublic | kAccFinal); // Proxies have 1 direct method, the constructor auto* directs = AllocArtMethodArray(self, 1); // Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we // want to throw OOM in the future. if (UNLIKELY(directs == nullptr)) { self->AssertPendingOOMException(); return nullptr; } klass->SetDirectMethodsPtr(directs); klass->SetNumDirectMethods(1u); CreateProxyConstructor(klass, klass->GetDirectMethodUnchecked(0, image_pointer_size_)); // Create virtual method using specified prototypes. auto h_methods = hs.NewHandle(soa.Decode*>(methods)); DCHECK_EQ(h_methods->GetClass(), mirror::Method::ArrayClass()) << PrettyClass(h_methods->GetClass()); const size_t num_virtual_methods = h_methods->GetLength(); auto* virtuals = AllocArtMethodArray(self, num_virtual_methods); // Currently AllocArtMethodArray cannot return null, but the OOM logic is left there in case we // want to throw OOM in the future. if (UNLIKELY(virtuals == nullptr)) { self->AssertPendingOOMException(); return nullptr; } klass->SetVirtualMethodsPtr(virtuals); klass->SetNumVirtualMethods(num_virtual_methods); for (size_t i = 0; i < num_virtual_methods; ++i) { auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); auto* prototype = h_methods->Get(i)->GetArtMethod(); CreateProxyMethod(klass, prototype, virtual_method); DCHECK(virtual_method->GetDeclaringClass() != nullptr); DCHECK(prototype->GetDeclaringClass() != nullptr); } // The super class is java.lang.reflect.Proxy klass->SetSuperClass(GetClassRoot(kJavaLangReflectProxy)); // Now effectively in the loaded state. mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, self); self->AssertNoPendingException(); MutableHandle new_class = hs.NewHandle(nullptr); { // Must hold lock on object when resolved. ObjectLock resolution_lock(self, klass); // Link the fields and virtual methods, creating vtable and iftables. // The new class will replace the old one in the class table. Handle> h_interfaces( hs.NewHandle(soa.Decode*>(interfaces))); if (!LinkClass(self, descriptor.c_str(), klass, h_interfaces, &new_class)) { mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); return nullptr; } } CHECK(klass->IsRetired()); CHECK_NE(klass.Get(), new_class.Get()); klass.Assign(new_class.Get()); CHECK_EQ(interfaces_sfield->GetDeclaringClass(), klass.Get()); interfaces_sfield->SetObject(klass.Get(), soa.Decode*>(interfaces)); CHECK_EQ(throws_sfield->GetDeclaringClass(), klass.Get()); throws_sfield->SetObject(klass.Get(), soa.Decode >*>(throws)); { // Lock on klass is released. Lock new class object. ObjectLock initialization_lock(self, klass); mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self); } // sanity checks if (kIsDebugBuild) { CHECK(klass->GetIFields() == nullptr); CheckProxyConstructor(klass->GetDirectMethod(0, image_pointer_size_)); for (size_t i = 0; i < num_virtual_methods; ++i) { auto* virtual_method = klass->GetVirtualMethodUnchecked(i, image_pointer_size_); auto* prototype = h_methods->Get(i++)->GetArtMethod(); CheckProxyMethod(virtual_method, prototype); } StackHandleScope<1> hs2(self); Handle decoded_name = hs2.NewHandle(soa.Decode(name)); std::string interfaces_field_name(StringPrintf("java.lang.Class[] %s.interfaces", decoded_name->ToModifiedUtf8().c_str())); CHECK_EQ(PrettyField(klass->GetStaticField(0)), interfaces_field_name); std::string throws_field_name(StringPrintf("java.lang.Class[][] %s.throws", decoded_name->ToModifiedUtf8().c_str())); CHECK_EQ(PrettyField(klass->GetStaticField(1)), throws_field_name); CHECK_EQ(klass.Get()->GetInterfaces(), soa.Decode*>(interfaces)); CHECK_EQ(klass.Get()->GetThrows(), soa.Decode>*>(throws)); } return klass.Get(); } std::string ClassLinker::GetDescriptorForProxy(mirror::Class* proxy_class) { DCHECK(proxy_class->IsProxyClass()); mirror::String* name = proxy_class->GetName(); DCHECK(name != nullptr); return DotToDescriptor(name->ToModifiedUtf8().c_str()); } ArtMethod* ClassLinker::FindMethodForProxy(mirror::Class* proxy_class, ArtMethod* proxy_method) { DCHECK(proxy_class->IsProxyClass()); DCHECK(proxy_method->IsProxyMethod()); { ReaderMutexLock mu(Thread::Current(), dex_lock_); // Locate the dex cache of the original interface/Object for (const GcRoot& root : dex_caches_) { auto* dex_cache = root.Read(); if (proxy_method->HasSameDexCacheResolvedTypes(dex_cache->GetResolvedTypes())) { ArtMethod* resolved_method = dex_cache->GetResolvedMethod( proxy_method->GetDexMethodIndex(), image_pointer_size_); CHECK(resolved_method != nullptr); return resolved_method; } } } LOG(FATAL) << "Didn't find dex cache for " << PrettyClass(proxy_class) << " " << PrettyMethod(proxy_method); UNREACHABLE(); } void ClassLinker::CreateProxyConstructor(Handle klass, ArtMethod* out) { // Create constructor for Proxy that must initialize the method. CHECK_EQ(GetClassRoot(kJavaLangReflectProxy)->NumDirectMethods(), 16u); ArtMethod* proxy_constructor = GetClassRoot(kJavaLangReflectProxy)->GetDirectMethodUnchecked( 2, image_pointer_size_); // Ensure constructor is in dex cache so that we can use the dex cache to look up the overridden // constructor method. GetClassRoot(kJavaLangReflectProxy)->GetDexCache()->SetResolvedMethod( proxy_constructor->GetDexMethodIndex(), proxy_constructor, image_pointer_size_); // Clone the existing constructor of Proxy (our constructor would just invoke it so steal its // code_ too) DCHECK(out != nullptr); out->CopyFrom(proxy_constructor, image_pointer_size_); // Make this constructor public and fix the class to be our Proxy version out->SetAccessFlags((out->GetAccessFlags() & ~kAccProtected) | kAccPublic); out->SetDeclaringClass(klass.Get()); } void ClassLinker::CheckProxyConstructor(ArtMethod* constructor) const { CHECK(constructor->IsConstructor()); auto* np = constructor->GetInterfaceMethodIfProxy(image_pointer_size_); CHECK_STREQ(np->GetName(), ""); CHECK_STREQ(np->GetSignature().ToString().c_str(), "(Ljava/lang/reflect/InvocationHandler;)V"); DCHECK(constructor->IsPublic()); } void ClassLinker::CreateProxyMethod(Handle klass, ArtMethod* prototype, ArtMethod* out) { // Ensure prototype is in dex cache so that we can use the dex cache to look up the overridden // prototype method auto* dex_cache = prototype->GetDeclaringClass()->GetDexCache(); // Avoid dirtying the dex cache unless we need to. if (dex_cache->GetResolvedMethod(prototype->GetDexMethodIndex(), image_pointer_size_) != prototype) { dex_cache->SetResolvedMethod( prototype->GetDexMethodIndex(), prototype, image_pointer_size_); } // We steal everything from the prototype (such as DexCache, invoke stub, etc.) then specialize // as necessary DCHECK(out != nullptr); out->CopyFrom(prototype, image_pointer_size_); // Set class to be the concrete proxy class and clear the abstract flag, modify exceptions to // the intersection of throw exceptions as defined in Proxy out->SetDeclaringClass(klass.Get()); out->SetAccessFlags((out->GetAccessFlags() & ~kAccAbstract) | kAccFinal); // At runtime the method looks like a reference and argument saving method, clone the code // related parameters from this method. out->SetEntryPointFromQuickCompiledCode(GetQuickProxyInvokeHandler()); out->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); } void ClassLinker::CheckProxyMethod(ArtMethod* method, ArtMethod* prototype) const { // Basic sanity CHECK(!prototype->IsFinal()); CHECK(method->IsFinal()); CHECK(!method->IsAbstract()); // The proxy method doesn't have its own dex cache or dex file and so it steals those of its // interface prototype. The exception to this are Constructors and the Class of the Proxy itself. CHECK(prototype->HasSameDexCacheResolvedMethods(method)); CHECK(prototype->HasSameDexCacheResolvedTypes(method)); auto* np = method->GetInterfaceMethodIfProxy(image_pointer_size_); CHECK_EQ(prototype->GetDeclaringClass()->GetDexCache(), np->GetDexCache()); CHECK_EQ(prototype->GetDexMethodIndex(), method->GetDexMethodIndex()); CHECK_STREQ(np->GetName(), prototype->GetName()); CHECK_STREQ(np->GetShorty(), prototype->GetShorty()); // More complex sanity - via dex cache CHECK_EQ(np->GetReturnType(), prototype->GetReturnType()); } bool ClassLinker::CanWeInitializeClass(mirror::Class* klass, bool can_init_statics, bool can_init_parents) { if (can_init_statics && can_init_parents) { return true; } if (!can_init_statics) { // Check if there's a class initializer. ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_); if (clinit != nullptr) { return false; } // Check if there are encoded static values needing initialization. if (klass->NumStaticFields() != 0) { const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); DCHECK(dex_class_def != nullptr); if (dex_class_def->static_values_off_ != 0) { return false; } } } if (klass->IsInterface() || !klass->HasSuperClass()) { return true; } mirror::Class* super_class = klass->GetSuperClass(); if (!can_init_parents && !super_class->IsInitialized()) { return false; } return CanWeInitializeClass(super_class, can_init_statics, can_init_parents); } bool ClassLinker::InitializeClass(Thread* self, Handle klass, bool can_init_statics, bool can_init_parents) { // see JLS 3rd edition, 12.4.2 "Detailed Initialization Procedure" for the locking protocol // Are we already initialized and therefore done? // Note: we differ from the JLS here as we don't do this under the lock, this is benign as // an initialized class will never change its state. if (klass->IsInitialized()) { return true; } // Fast fail if initialization requires a full runtime. Not part of the JLS. if (!CanWeInitializeClass(klass.Get(), can_init_statics, can_init_parents)) { return false; } self->AllowThreadSuspension(); uint64_t t0; { ObjectLock lock(self, klass); // Re-check under the lock in case another thread initialized ahead of us. if (klass->IsInitialized()) { return true; } // Was the class already found to be erroneous? Done under the lock to match the JLS. if (klass->IsErroneous()) { ThrowEarlierClassFailure(klass.Get()); VlogClassInitializationFailure(klass); return false; } CHECK(klass->IsResolved()) << PrettyClass(klass.Get()) << ": state=" << klass->GetStatus(); if (!klass->IsVerified()) { VerifyClass(self, klass); if (!klass->IsVerified()) { // We failed to verify, expect either the klass to be erroneous or verification failed at // compile time. if (klass->IsErroneous()) { CHECK(self->IsExceptionPending()); VlogClassInitializationFailure(klass); } else { CHECK(Runtime::Current()->IsAotCompiler()); CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusRetryVerificationAtRuntime); } return false; } else { self->AssertNoPendingException(); } } // If the class is kStatusInitializing, either this thread is // initializing higher up the stack or another thread has beat us // to initializing and we need to wait. Either way, this // invocation of InitializeClass will not be responsible for // running and will return. if (klass->GetStatus() == mirror::Class::kStatusInitializing) { // Could have got an exception during verification. if (self->IsExceptionPending()) { VlogClassInitializationFailure(klass); return false; } // We caught somebody else in the act; was it us? if (klass->GetClinitThreadId() == self->GetTid()) { // Yes. That's fine. Return so we can continue initializing. return true; } // No. That's fine. Wait for another thread to finish initializing. return WaitForInitializeClass(klass, self, lock); } if (!ValidateSuperClassDescriptors(klass)) { mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); return false; } self->AllowThreadSuspension(); CHECK_EQ(klass->GetStatus(), mirror::Class::kStatusVerified) << PrettyClass(klass.Get()); // From here out other threads may observe that we're initializing and so changes of state // require the a notification. klass->SetClinitThreadId(self->GetTid()); mirror::Class::SetStatus(klass, mirror::Class::kStatusInitializing, self); t0 = NanoTime(); } // Initialize super classes, must be done while initializing for the JLS. if (!klass->IsInterface() && klass->HasSuperClass()) { mirror::Class* super_class = klass->GetSuperClass(); if (!super_class->IsInitialized()) { CHECK(!super_class->IsInterface()); CHECK(can_init_parents); StackHandleScope<1> hs(self); Handle handle_scope_super(hs.NewHandle(super_class)); bool super_initialized = InitializeClass(self, handle_scope_super, can_init_statics, true); if (!super_initialized) { // The super class was verified ahead of entering initializing, we should only be here if // the super class became erroneous due to initialization. CHECK(handle_scope_super->IsErroneous() && self->IsExceptionPending()) << "Super class initialization failed for " << PrettyDescriptor(handle_scope_super.Get()) << " that has unexpected status " << handle_scope_super->GetStatus() << "\nPending exception:\n" << (self->GetException() != nullptr ? self->GetException()->Dump() : ""); ObjectLock lock(self, klass); // Initialization failed because the super-class is erroneous. mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); return false; } } } const size_t num_static_fields = klass->NumStaticFields(); if (num_static_fields > 0) { const DexFile::ClassDef* dex_class_def = klass->GetClassDef(); CHECK(dex_class_def != nullptr); const DexFile& dex_file = klass->GetDexFile(); StackHandleScope<3> hs(self); Handle class_loader(hs.NewHandle(klass->GetClassLoader())); Handle dex_cache(hs.NewHandle(klass->GetDexCache())); // Eagerly fill in static fields so that the we don't have to do as many expensive // Class::FindStaticField in ResolveField. for (size_t i = 0; i < num_static_fields; ++i) { ArtField* field = klass->GetStaticField(i); const uint32_t field_idx = field->GetDexFieldIndex(); ArtField* resolved_field = dex_cache->GetResolvedField(field_idx, image_pointer_size_); if (resolved_field == nullptr) { dex_cache->SetResolvedField(field_idx, field, image_pointer_size_); } else { DCHECK_EQ(field, resolved_field); } } EncodedStaticFieldValueIterator value_it(dex_file, &dex_cache, &class_loader, this, *dex_class_def); const uint8_t* class_data = dex_file.GetClassData(*dex_class_def); ClassDataItemIterator field_it(dex_file, class_data); if (value_it.HasNext()) { DCHECK(field_it.HasNextStaticField()); CHECK(can_init_statics); for ( ; value_it.HasNext(); value_it.Next(), field_it.Next()) { ArtField* field = ResolveField( dex_file, field_it.GetMemberIndex(), dex_cache, class_loader, true); if (Runtime::Current()->IsActiveTransaction()) { value_it.ReadValueToField(field); } else { value_it.ReadValueToField(field); } DCHECK(!value_it.HasNext() || field_it.HasNextStaticField()); } } } ArtMethod* clinit = klass->FindClassInitializer(image_pointer_size_); if (clinit != nullptr) { CHECK(can_init_statics); JValue result; clinit->Invoke(self, nullptr, 0, &result, "V"); } self->AllowThreadSuspension(); uint64_t t1 = NanoTime(); bool success = true; { ObjectLock lock(self, klass); if (self->IsExceptionPending()) { WrapExceptionInInitializer(klass); mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); success = false; } else if (Runtime::Current()->IsTransactionAborted()) { // The exception thrown when the transaction aborted has been caught and cleared // so we need to throw it again now. VLOG(compiler) << "Return from class initializer of " << PrettyDescriptor(klass.Get()) << " without exception while transaction was aborted: re-throw it now."; Runtime::Current()->ThrowTransactionAbortError(self); mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); success = false; } else { RuntimeStats* global_stats = Runtime::Current()->GetStats(); RuntimeStats* thread_stats = self->GetStats(); ++global_stats->class_init_count; ++thread_stats->class_init_count; global_stats->class_init_time_ns += (t1 - t0); thread_stats->class_init_time_ns += (t1 - t0); // Set the class as initialized except if failed to initialize static fields. mirror::Class::SetStatus(klass, mirror::Class::kStatusInitialized, self); if (VLOG_IS_ON(class_linker)) { std::string temp; LOG(INFO) << "Initialized class " << klass->GetDescriptor(&temp) << " from " << klass->GetLocation(); } // Opportunistically set static method trampolines to their destination. FixupStaticTrampolines(klass.Get()); } } return success; } bool ClassLinker::WaitForInitializeClass(Handle klass, Thread* self, ObjectLock& lock) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { while (true) { self->AssertNoPendingException(); CHECK(!klass->IsInitialized()); lock.WaitIgnoringInterrupts(); // When we wake up, repeat the test for init-in-progress. If // there's an exception pending (only possible if // we were not using WaitIgnoringInterrupts), bail out. if (self->IsExceptionPending()) { WrapExceptionInInitializer(klass); mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); return false; } // Spurious wakeup? Go back to waiting. if (klass->GetStatus() == mirror::Class::kStatusInitializing) { continue; } if (klass->GetStatus() == mirror::Class::kStatusVerified && Runtime::Current()->IsAotCompiler()) { // Compile time initialization failed. return false; } if (klass->IsErroneous()) { // The caller wants an exception, but it was thrown in a // different thread. Synthesize one here. ThrowNoClassDefFoundError(" failed for class %s; see exception in other thread", PrettyDescriptor(klass.Get()).c_str()); VlogClassInitializationFailure(klass); return false; } if (klass->IsInitialized()) { return true; } LOG(FATAL) << "Unexpected class status. " << PrettyClass(klass.Get()) << " is " << klass->GetStatus(); } UNREACHABLE(); } static void ThrowSignatureCheckResolveReturnTypeException(Handle klass, Handle super_klass, ArtMethod* method, ArtMethod* m) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { DCHECK(Thread::Current()->IsExceptionPending()); DCHECK(!m->IsProxyMethod()); const DexFile* dex_file = m->GetDexFile(); const DexFile::MethodId& method_id = dex_file->GetMethodId(m->GetDexMethodIndex()); const DexFile::ProtoId& proto_id = dex_file->GetMethodPrototype(method_id); uint16_t return_type_idx = proto_id.return_type_idx_; std::string return_type = PrettyType(return_type_idx, *dex_file); std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader()); ThrowWrappedLinkageError(klass.Get(), "While checking class %s method %s signature against %s %s: " "Failed to resolve return type %s with %s", PrettyDescriptor(klass.Get()).c_str(), PrettyMethod(method).c_str(), super_klass->IsInterface() ? "interface" : "superclass", PrettyDescriptor(super_klass.Get()).c_str(), return_type.c_str(), class_loader.c_str()); } static void ThrowSignatureCheckResolveArgException(Handle klass, Handle super_klass, ArtMethod* method, ArtMethod* m, uint32_t index, uint32_t arg_type_idx) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { DCHECK(Thread::Current()->IsExceptionPending()); DCHECK(!m->IsProxyMethod()); const DexFile* dex_file = m->GetDexFile(); std::string arg_type = PrettyType(arg_type_idx, *dex_file); std::string class_loader = PrettyTypeOf(m->GetDeclaringClass()->GetClassLoader()); ThrowWrappedLinkageError(klass.Get(), "While checking class %s method %s signature against %s %s: " "Failed to resolve arg %u type %s with %s", PrettyDescriptor(klass.Get()).c_str(), PrettyMethod(method).c_str(), super_klass->IsInterface() ? "interface" : "superclass", PrettyDescriptor(super_klass.Get()).c_str(), index, arg_type.c_str(), class_loader.c_str()); } static void ThrowSignatureMismatch(Handle klass, Handle super_klass, ArtMethod* method, const std::string& error_msg) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { ThrowLinkageError(klass.Get(), "Class %s method %s resolves differently in %s %s: %s", PrettyDescriptor(klass.Get()).c_str(), PrettyMethod(method).c_str(), super_klass->IsInterface() ? "interface" : "superclass", PrettyDescriptor(super_klass.Get()).c_str(), error_msg.c_str()); } static bool HasSameSignatureWithDifferentClassLoaders(Thread* self, Handle klass, Handle super_klass, ArtMethod* method1, ArtMethod* method2) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { { StackHandleScope<1> hs(self); Handle return_type(hs.NewHandle(method1->GetReturnType())); if (UNLIKELY(return_type.Get() == nullptr)) { ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method1); return false; } mirror::Class* other_return_type = method2->GetReturnType(); if (UNLIKELY(other_return_type == nullptr)) { ThrowSignatureCheckResolveReturnTypeException(klass, super_klass, method1, method2); return false; } if (UNLIKELY(other_return_type != return_type.Get())) { ThrowSignatureMismatch(klass, super_klass, method1, StringPrintf("Return types mismatch: %s(%p) vs %s(%p)", PrettyClassAndClassLoader(return_type.Get()).c_str(), return_type.Get(), PrettyClassAndClassLoader(other_return_type).c_str(), other_return_type)); return false; } } const DexFile::TypeList* types1 = method1->GetParameterTypeList(); const DexFile::TypeList* types2 = method2->GetParameterTypeList(); if (types1 == nullptr) { if (types2 != nullptr && types2->Size() != 0) { ThrowSignatureMismatch(klass, super_klass, method1, StringPrintf("Type list mismatch with %s", PrettyMethod(method2, true).c_str())); return false; } return true; } else if (UNLIKELY(types2 == nullptr)) { if (types1->Size() != 0) { ThrowSignatureMismatch(klass, super_klass, method1, StringPrintf("Type list mismatch with %s", PrettyMethod(method2, true).c_str())); return false; } return true; } uint32_t num_types = types1->Size(); if (UNLIKELY(num_types != types2->Size())) { ThrowSignatureMismatch(klass, super_klass, method1, StringPrintf("Type list mismatch with %s", PrettyMethod(method2, true).c_str())); return false; } for (uint32_t i = 0; i < num_types; ++i) { StackHandleScope<1> hs(self); uint32_t param_type_idx = types1->GetTypeItem(i).type_idx_; Handle param_type(hs.NewHandle( method1->GetClassFromTypeIndex(param_type_idx, true))); if (UNLIKELY(param_type.Get() == nullptr)) { ThrowSignatureCheckResolveArgException(klass, super_klass, method1, method1, i, param_type_idx); return false; } uint32_t other_param_type_idx = types2->GetTypeItem(i).type_idx_; mirror::Class* other_param_type = method2->GetClassFromTypeIndex(other_param_type_idx, true); if (UNLIKELY(other_param_type == nullptr)) { ThrowSignatureCheckResolveArgException(klass, super_klass, method1, method2, i, other_param_type_idx); return false; } if (UNLIKELY(param_type.Get() != other_param_type)) { ThrowSignatureMismatch(klass, super_klass, method1, StringPrintf("Parameter %u type mismatch: %s(%p) vs %s(%p)", i, PrettyClassAndClassLoader(param_type.Get()).c_str(), param_type.Get(), PrettyClassAndClassLoader(other_param_type).c_str(), other_param_type)); return false; } } return true; } bool ClassLinker::ValidateSuperClassDescriptors(Handle klass) { if (klass->IsInterface()) { return true; } // Begin with the methods local to the superclass. Thread* self = Thread::Current(); StackHandleScope<1> hs(self); MutableHandle super_klass(hs.NewHandle(nullptr)); if (klass->HasSuperClass() && klass->GetClassLoader() != klass->GetSuperClass()->GetClassLoader()) { super_klass.Assign(klass->GetSuperClass()); for (int i = klass->GetSuperClass()->GetVTableLength() - 1; i >= 0; --i) { auto* m = klass->GetVTableEntry(i, image_pointer_size_); auto* super_m = klass->GetSuperClass()->GetVTableEntry(i, image_pointer_size_); if (m != super_m) { if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, klass, super_klass, m, super_m))) { self->AssertPendingException(); return false; } } } } for (int32_t i = 0; i < klass->GetIfTableCount(); ++i) { super_klass.Assign(klass->GetIfTable()->GetInterface(i)); if (klass->GetClassLoader() != super_klass->GetClassLoader()) { uint32_t num_methods = super_klass->NumVirtualMethods(); for (uint32_t j = 0; j < num_methods; ++j) { auto* m = klass->GetIfTable()->GetMethodArray(i)->GetElementPtrSize( j, image_pointer_size_); auto* super_m = super_klass->GetVirtualMethod(j, image_pointer_size_); if (m != super_m) { if (UNLIKELY(!HasSameSignatureWithDifferentClassLoaders(self, klass, super_klass, m, super_m))) { self->AssertPendingException(); return false; } } } } } return true; } bool ClassLinker::EnsureInitialized(Thread* self, Handle c, bool can_init_fields, bool can_init_parents) { DCHECK(c.Get() != nullptr); if (c->IsInitialized()) { EnsurePreverifiedMethods(c); return true; } const bool success = InitializeClass(self, c, can_init_fields, can_init_parents); if (!success) { if (can_init_fields && can_init_parents) { CHECK(self->IsExceptionPending()) << PrettyClass(c.Get()); } } else { self->AssertNoPendingException(); } return success; } void ClassLinker::FixupTemporaryDeclaringClass(mirror::Class* temp_class, mirror::Class* new_class) { ArtField* fields = new_class->GetIFields(); DCHECK_EQ(temp_class->NumInstanceFields(), new_class->NumInstanceFields()); for (size_t i = 0, count = new_class->NumInstanceFields(); i < count; i++) { if (fields[i].GetDeclaringClass() == temp_class) { fields[i].SetDeclaringClass(new_class); } } fields = new_class->GetSFields(); DCHECK_EQ(temp_class->NumStaticFields(), new_class->NumStaticFields()); for (size_t i = 0, count = new_class->NumStaticFields(); i < count; i++) { if (fields[i].GetDeclaringClass() == temp_class) { fields[i].SetDeclaringClass(new_class); } } DCHECK_EQ(temp_class->NumDirectMethods(), new_class->NumDirectMethods()); for (auto& method : new_class->GetDirectMethods(image_pointer_size_)) { if (method.GetDeclaringClass() == temp_class) { method.SetDeclaringClass(new_class); } } DCHECK_EQ(temp_class->NumVirtualMethods(), new_class->NumVirtualMethods()); for (auto& method : new_class->GetVirtualMethods(image_pointer_size_)) { if (method.GetDeclaringClass() == temp_class) { method.SetDeclaringClass(new_class); } } } bool ClassLinker::LinkClass(Thread* self, const char* descriptor, Handle klass, Handle> interfaces, MutableHandle* h_new_class_out) { CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus()); if (!LinkSuperClass(klass)) { return false; } ArtMethod* imt[mirror::Class::kImtSize]; std::fill_n(imt, arraysize(imt), Runtime::Current()->GetImtUnimplementedMethod()); if (!LinkMethods(self, klass, interfaces, imt)) { return false; } if (!LinkInstanceFields(self, klass)) { return false; } size_t class_size; if (!LinkStaticFields(self, klass, &class_size)) { return false; } CreateReferenceInstanceOffsets(klass); CHECK_EQ(mirror::Class::kStatusLoaded, klass->GetStatus()); if (!klass->IsTemp() || (!init_done_ && klass->GetClassSize() == class_size)) { // We don't need to retire this class as it has no embedded tables or it was created the // correct size during class linker initialization. CHECK_EQ(klass->GetClassSize(), class_size) << PrettyDescriptor(klass.Get()); if (klass->ShouldHaveEmbeddedImtAndVTable()) { klass->PopulateEmbeddedImtAndVTable(imt, image_pointer_size_); } // This will notify waiters on klass that saw the not yet resolved // class in the class_table_ during EnsureResolved. mirror::Class::SetStatus(klass, mirror::Class::kStatusResolved, self); h_new_class_out->Assign(klass.Get()); } else { CHECK(!klass->IsResolved()); // Retire the temporary class and create the correctly sized resolved class. StackHandleScope<1> hs(self); auto h_new_class = hs.NewHandle(klass->CopyOf(self, class_size, imt, image_pointer_size_)); if (UNLIKELY(h_new_class.Get() == nullptr)) { self->AssertPendingOOMException(); mirror::Class::SetStatus(klass, mirror::Class::kStatusError, self); return false; } CHECK_EQ(h_new_class->GetClassSize(), class_size); ObjectLock lock(self, h_new_class); FixupTemporaryDeclaringClass(klass.Get(), h_new_class.Get()); mirror::Class* existing = UpdateClass(descriptor, h_new_class.Get(), ComputeModifiedUtf8Hash(descriptor)); CHECK(existing == nullptr || existing == klass.Get()); // This will notify waiters on temp class that saw the not yet resolved class in the // class_table_ during EnsureResolved. mirror::Class::SetStatus(klass, mirror::Class::kStatusRetired, self); CHECK_EQ(h_new_class->GetStatus(), mirror::Class::kStatusResolving); // This will notify waiters on new_class that saw the not yet resolved // class in the class_table_ during EnsureResolved. mirror::Class::SetStatus(h_new_class, mirror::Class::kStatusResolved, self); // Return the new class. h_new_class_out->Assign(h_new_class.Get()); } return true; } static void CountMethodsAndFields(ClassDataItemIterator& dex_data, size_t* virtual_methods, size_t* direct_methods, size_t* static_fields, size_t* instance_fields) { *virtual_methods = *direct_methods = *static_fields = *instance_fields = 0; while (dex_data.HasNextStaticField()) { dex_data.Next(); (*static_fields)++; } while (dex_data.HasNextInstanceField()) { dex_data.Next(); (*instance_fields)++; } while (dex_data.HasNextDirectMethod()) { (*direct_methods)++; dex_data.Next(); } while (dex_data.HasNextVirtualMethod()) { (*virtual_methods)++; dex_data.Next(); } DCHECK(!dex_data.HasNext()); } static void DumpClass(std::ostream& os, const DexFile& dex_file, const DexFile::ClassDef& dex_class_def, const char* suffix) { ClassDataItemIterator dex_data(dex_file, dex_file.GetClassData(dex_class_def)); os << dex_file.GetClassDescriptor(dex_class_def) << suffix << ":\n"; os << " Static fields:\n"; while (dex_data.HasNextStaticField()) { const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex()); os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n"; dex_data.Next(); } os << " Instance fields:\n"; while (dex_data.HasNextInstanceField()) { const DexFile::FieldId& id = dex_file.GetFieldId(dex_data.GetMemberIndex()); os << " " << dex_file.GetFieldTypeDescriptor(id) << " " << dex_file.GetFieldName(id) << "\n"; dex_data.Next(); } os << " Direct methods:\n"; while (dex_data.HasNextDirectMethod()) { const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex()); os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n"; dex_data.Next(); } os << " Virtual methods:\n"; while (dex_data.HasNextVirtualMethod()) { const DexFile::MethodId& id = dex_file.GetMethodId(dex_data.GetMemberIndex()); os << " " << dex_file.GetMethodName(id) << dex_file.GetMethodSignature(id).ToString() << "\n"; dex_data.Next(); } } static std::string DumpClasses(const DexFile& dex_file1, const DexFile::ClassDef& dex_class_def1, const DexFile& dex_file2, const DexFile::ClassDef& dex_class_def2) { std::ostringstream os; DumpClass(os, dex_file1, dex_class_def1, " (Compile time)"); DumpClass(os, dex_file2, dex_class_def2, " (Runtime)"); return os.str(); } // Very simple structural check on whether the classes match. Only compares the number of // methods and fields. static bool SimpleStructuralCheck(const DexFile& dex_file1, const DexFile::ClassDef& dex_class_def1, const DexFile& dex_file2, const DexFile::ClassDef& dex_class_def2, std::string* error_msg) { ClassDataItemIterator dex_data1(dex_file1, dex_file1.GetClassData(dex_class_def1)); ClassDataItemIterator dex_data2(dex_file2, dex_file2.GetClassData(dex_class_def2)); // Counters for current dex file. size_t dex_virtual_methods1, dex_direct_methods1, dex_static_fields1, dex_instance_fields1; CountMethodsAndFields(dex_data1, &dex_virtual_methods1, &dex_direct_methods1, &dex_static_fields1, &dex_instance_fields1); // Counters for compile-time dex file. size_t dex_virtual_methods2, dex_direct_methods2, dex_static_fields2, dex_instance_fields2; CountMethodsAndFields(dex_data2, &dex_virtual_methods2, &dex_direct_methods2, &dex_static_fields2, &dex_instance_fields2); if (dex_virtual_methods1 != dex_virtual_methods2) { std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); *error_msg = StringPrintf("Virtual method count off: %zu vs %zu\n%s", dex_virtual_methods1, dex_virtual_methods2, class_dump.c_str()); return false; } if (dex_direct_methods1 != dex_direct_methods2) { std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); *error_msg = StringPrintf("Direct method count off: %zu vs %zu\n%s", dex_direct_methods1, dex_direct_methods2, class_dump.c_str()); return false; } if (dex_static_fields1 != dex_static_fields2) { std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); *error_msg = StringPrintf("Static field count off: %zu vs %zu\n%s", dex_static_fields1, dex_static_fields2, class_dump.c_str()); return false; } if (dex_instance_fields1 != dex_instance_fields2) { std::string class_dump = DumpClasses(dex_file1, dex_class_def1, dex_file2, dex_class_def2); *error_msg = StringPrintf("Instance field count off: %zu vs %zu\n%s", dex_instance_fields1, dex_instance_fields2, class_dump.c_str()); return false; } return true; } // Checks whether a the super-class changed from what we had at compile-time. This would // invalidate quickening. static bool CheckSuperClassChange(Handle klass, const DexFile& dex_file, const DexFile::ClassDef& class_def, mirror::Class* super_class) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { // Check for unexpected changes in the superclass. // Quick check 1) is the super_class class-loader the boot class loader? This always has // precedence. if (super_class->GetClassLoader() != nullptr && // Quick check 2) different dex cache? Breaks can only occur for different dex files, // which is implied by different dex cache. klass->GetDexCache() != super_class->GetDexCache()) { // Now comes the expensive part: things can be broken if (a) the klass' dex file has a // definition for the super-class, and (b) the files are in separate oat files. The oat files // are referenced from the dex file, so do (b) first. Only relevant if we have oat files. const OatDexFile* class_oat_dex_file = dex_file.GetOatDexFile(); const OatFile* class_oat_file = nullptr; if (class_oat_dex_file != nullptr) { class_oat_file = class_oat_dex_file->GetOatFile(); } if (class_oat_file != nullptr) { const OatDexFile* loaded_super_oat_dex_file = super_class->GetDexFile().GetOatDexFile(); const OatFile* loaded_super_oat_file = nullptr; if (loaded_super_oat_dex_file != nullptr) { loaded_super_oat_file = loaded_super_oat_dex_file->GetOatFile(); } if (loaded_super_oat_file != nullptr && class_oat_file != loaded_super_oat_file) { // Now check (a). const DexFile::ClassDef* super_class_def = dex_file.FindClassDef(class_def.superclass_idx_); if (super_class_def != nullptr) { // Uh-oh, we found something. Do our check. std::string error_msg; if (!SimpleStructuralCheck(dex_file, *super_class_def, super_class->GetDexFile(), *super_class->GetClassDef(), &error_msg)) { // Print a warning to the log. This exception might be caught, e.g., as common in test // drivers. When the class is later tried to be used, we re-throw a new instance, as we // only save the type of the exception. LOG(WARNING) << "Incompatible structural change detected: " << StringPrintf( "Structural change of %s is hazardous (%s at compile time, %s at runtime): %s", PrettyType(super_class_def->class_idx_, dex_file).c_str(), class_oat_file->GetLocation().c_str(), loaded_super_oat_file->GetLocation().c_str(), error_msg.c_str()); ThrowIncompatibleClassChangeError(klass.Get(), "Structural change of %s is hazardous (%s at compile time, %s at runtime): %s", PrettyType(super_class_def->class_idx_, dex_file).c_str(), class_oat_file->GetLocation().c_str(), loaded_super_oat_file->GetLocation().c_str(), error_msg.c_str()); return false; } } } } } return true; } bool ClassLinker::LoadSuperAndInterfaces(Handle klass, const DexFile& dex_file) { CHECK_EQ(mirror::Class::kStatusIdx, klass->GetStatus()); const DexFile::ClassDef& class_def = dex_file.GetClassDef(klass->GetDexClassDefIndex()); uint16_t super_class_idx = class_def.superclass_idx_; if (super_class_idx != DexFile::kDexNoIndex16) { mirror::Class* super_class = ResolveType(dex_file, super_class_idx, klass.Get()); if (super_class == nullptr) { DCHECK(Thread::Current()->IsExceptionPending()); return false; } // Verify if (!klass->CanAccess(super_class)) { ThrowIllegalAccessError(klass.Get(), "Class %s extended by class %s is inaccessible", PrettyDescriptor(super_class).c_str(), PrettyDescriptor(klass.Get()).c_str()); return false; } CHECK(super_class->IsResolved()); klass->SetSuperClass(super_class); if (!CheckSuperClassChange(klass, dex_file, class_def, super_class)) { DCHECK(Thread::Current()->IsExceptionPending()); return false; } } const DexFile::TypeList* interfaces = dex_file.GetInterfacesList(class_def); if (interfaces != nullptr) { for (size_t i = 0; i < interfaces->Size(); i++) { uint16_t idx = interfaces->GetTypeItem(i).type_idx_; mirror::Class* interface = ResolveType(dex_file, idx, klass.Get()); if (interface == nullptr) { DCHECK(Thread::Current()->IsExceptionPending()); return false; } // Verify if (!klass->CanAccess(interface)) { // TODO: the RI seemed to ignore this in my testing. ThrowIllegalAccessError(klass.Get(), "Interface %s implemented by class %s is inaccessible", PrettyDescriptor(interface).c_str(), PrettyDescriptor(klass.Get()).c_str()); return false; } } } // Mark the class as loaded. mirror::Class::SetStatus(klass, mirror::Class::kStatusLoaded, nullptr); return true; } bool ClassLinker::LinkSuperClass(Handle klass) { CHECK(!klass->IsPrimitive()); mirror::Class* super = klass->GetSuperClass(); if (klass.Get() == GetClassRoot(kJavaLangObject)) { if (super != nullptr) { ThrowClassFormatError(klass.Get(), "java.lang.Object must not have a superclass"); return false; } return true; } if (super == nullptr) { ThrowLinkageError(klass.Get(), "No superclass defined for class %s", PrettyDescriptor(klass.Get()).c_str()); return false; } // Verify if (super->IsFinal() || super->IsInterface()) { ThrowIncompatibleClassChangeError(klass.Get(), "Superclass %s of %s is %s", PrettyDescriptor(super).c_str(), PrettyDescriptor(klass.Get()).c_str(), super->IsFinal() ? "declared final" : "an interface"); return false; } if (!klass->CanAccess(super)) { ThrowIllegalAccessError(klass.Get(), "Superclass %s is inaccessible to class %s", PrettyDescriptor(super).c_str(), PrettyDescriptor(klass.Get()).c_str()); return false; } // Inherit kAccClassIsFinalizable from the superclass in case this // class doesn't override finalize. if (super->IsFinalizable()) { klass->SetFinalizable(); } // Inherit reference flags (if any) from the superclass. int reference_flags = (super->GetAccessFlags() & kAccReferenceFlagsMask); if (reference_flags != 0) { klass->SetAccessFlags(klass->GetAccessFlags() | reference_flags); } // Disallow custom direct subclasses of java.lang.ref.Reference. if (init_done_ && super == GetClassRoot(kJavaLangRefReference)) { ThrowLinkageError(klass.Get(), "Class %s attempts to subclass java.lang.ref.Reference, which is not allowed", PrettyDescriptor(klass.Get()).c_str()); return false; } if (kIsDebugBuild) { // Ensure super classes are fully resolved prior to resolving fields.. while (super != nullptr) { CHECK(super->IsResolved()); super = super->GetSuperClass(); } } return true; } // Populate the class vtable and itable. Compute return type indices. bool ClassLinker::LinkMethods(Thread* self, Handle klass, Handle> interfaces, ArtMethod** out_imt) { self->AllowThreadSuspension(); if (klass->IsInterface()) { // No vtable. size_t count = klass->NumVirtualMethods(); if (!IsUint<16>(count)) { ThrowClassFormatError(klass.Get(), "Too many methods on interface: %zd", count); return false; } for (size_t i = 0; i < count; ++i) { klass->GetVirtualMethodDuringLinking(i, image_pointer_size_)->SetMethodIndex(i); } } else if (!LinkVirtualMethods(self, klass)) { // Link virtual methods first. return false; } return LinkInterfaceMethods(self, klass, interfaces, out_imt); // Link interface method last. } // Comparator for name and signature of a method, used in finding overriding methods. Implementation // avoids the use of handles, if it didn't then rather than compare dex files we could compare dex // caches in the implementation below. class MethodNameAndSignatureComparator FINAL : public ValueObject { public: explicit MethodNameAndSignatureComparator(ArtMethod* method) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) : dex_file_(method->GetDexFile()), mid_(&dex_file_->GetMethodId(method->GetDexMethodIndex())), name_(nullptr), name_len_(0) { DCHECK(!method->IsProxyMethod()) << PrettyMethod(method); } const char* GetName() { if (name_ == nullptr) { name_ = dex_file_->StringDataAndUtf16LengthByIdx(mid_->name_idx_, &name_len_); } return name_; } bool HasSameNameAndSignature(ArtMethod* other) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { DCHECK(!other->IsProxyMethod()) << PrettyMethod(other); const DexFile* other_dex_file = other->GetDexFile(); const DexFile::MethodId& other_mid = other_dex_file->GetMethodId(other->GetDexMethodIndex()); if (dex_file_ == other_dex_file) { return mid_->name_idx_ == other_mid.name_idx_ && mid_->proto_idx_ == other_mid.proto_idx_; } GetName(); // Only used to make sure its calculated. uint32_t other_name_len; const char* other_name = other_dex_file->StringDataAndUtf16LengthByIdx(other_mid.name_idx_, &other_name_len); if (name_len_ != other_name_len || strcmp(name_, other_name) != 0) { return false; } return dex_file_->GetMethodSignature(*mid_) == other_dex_file->GetMethodSignature(other_mid); } private: // Dex file for the method to compare against. const DexFile* const dex_file_; // MethodId for the method to compare against. const DexFile::MethodId* const mid_; // Lazily computed name from the dex file's strings. const char* name_; // Lazily computed name length. uint32_t name_len_; }; class LinkVirtualHashTable { public: LinkVirtualHashTable(Handle klass, size_t hash_size, uint32_t* hash_table, size_t image_pointer_size) : klass_(klass), hash_size_(hash_size), hash_table_(hash_table), image_pointer_size_(image_pointer_size) { std::fill(hash_table_, hash_table_ + hash_size_, invalid_index_); } void Add(uint32_t virtual_method_index) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { ArtMethod* local_method = klass_->GetVirtualMethodDuringLinking( virtual_method_index, image_pointer_size_); const char* name = local_method->GetInterfaceMethodIfProxy(image_pointer_size_)->GetName(); uint32_t hash = ComputeModifiedUtf8Hash(name); uint32_t index = hash % hash_size_; // Linear probe until we have an empty slot. while (hash_table_[index] != invalid_index_) { if (++index == hash_size_) { index = 0; } } hash_table_[index] = virtual_method_index; } uint32_t FindAndRemove(MethodNameAndSignatureComparator* comparator) SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { const char* name = comparator->GetName(); uint32_t hash = ComputeModifiedUtf8Hash(name); size_t index = hash % hash_size_; while (true) { const uint32_t value = hash_table_[index]; // Since linear probe makes continuous blocks, hitting an invalid index means we are done // the block and can safely assume not found. if (value == invalid_index_) { break; } if (value != removed_index_) { // This signifies not already overriden. ArtMethod* virtual_method = klass_->GetVirtualMethodDuringLinking(value, image_pointer_size_); if (comparator->HasSameNameAndSignature( virtual_method->GetInterfaceMethodIfProxy(image_pointer_size_))) { hash_table_[index] = removed_index_; return value; } } if (++index == hash_size_) { index = 0; } } return GetNotFoundIndex(); } static uint32_t GetNotFoundIndex() { return invalid_index_; } private: static const uint32_t invalid_index_; static const uint32_t removed_index_; Handle klass_; const size_t hash_size_; uint32_t* const hash_table_; const size_t image_pointer_size_; }; const uint32_t LinkVirtualHashTable::invalid_index_ = std::numeric_limits::max(); const uint32_t LinkVirtualHashTable::removed_index_ = std::numeric_limits::max() - 1; bool ClassLinker::LinkVirtualMethods(Thread* self, Handle klass) { const size_t num_virtual_methods = klass->NumVirtualMethods(); if (klass->HasSuperClass()) { const size_t super_vtable_length = klass->GetSuperClass()->GetVTableLength(); const size_t max_count = num_virtual_methods + super_vtable_length; StackHandleScope<2> hs(self); Handle super_class(hs.NewHandle(klass->GetSuperClass())); MutableHandle vtable; if (super_class->ShouldHaveEmbeddedImtAndVTable()) { vtable = hs.NewHandle(AllocPointerArray(self, max_count)); if (UNLIKELY(vtable.Get() == nullptr)) { self->AssertPendingOOMException(); return false; } for (size_t i = 0; i < super_vtable_length; i++) { vtable->SetElementPtrSize( i, super_class->GetEmbeddedVTableEntry(i, image_pointer_size_), image_pointer_size_); } if (num_virtual_methods == 0) { klass->SetVTable(vtable.Get()); return true; } } else { auto* super_vtable = super_class->GetVTable(); CHECK(super_vtable != nullptr) << PrettyClass(super_class.Get()); if (num_virtual_methods == 0) { klass->SetVTable(super_vtable); return true; } vtable = hs.NewHandle(down_cast( super_vtable->CopyOf(self, max_count))); if (UNLIKELY(vtable.Get() == nullptr)) { self->AssertPendingOOMException(); return false; } } // How the algorithm works: // 1. Populate hash table by adding num_virtual_methods from klass. The values in the hash // table are: invalid_index for unused slots, index super_vtable_length + i for a virtual // method which has not been matched to a vtable method, and j if the virtual method at the // index overrode the super virtual method at index j. // 2. Loop through super virtual methods, if they overwrite, update hash table to j // (j < super_vtable_length) to avoid redundant checks. (TODO maybe use this info for reducing // the need for the initial vtable which we later shrink back down). // 3. Add non overridden methods to the end of the vtable. static constexpr size_t kMaxStackHash = 250; const size_t hash_table_size = num_virtual_methods * 3; uint32_t* hash_table_ptr; std::unique_ptr hash_heap_storage; if (hash_table_size <= kMaxStackHash) { hash_table_ptr = reinterpret_cast( alloca(hash_table_size * sizeof(*hash_table_ptr))); } else { hash_heap_storage.reset(new uint32_t[hash_table_size]); hash_table_ptr = hash_heap_storage.get(); } LinkVirtualHashTable hash_table(klass, hash_table_size, hash_table_ptr, image_pointer_size_); // Add virtual methods to the hash table. for (size_t i = 0; i < num_virtual_methods; ++i) { DCHECK(klass->GetVirtualMethodDuringLinking( i, image_pointer_size_)->GetDeclaringClass() != nullptr); hash_table.Add(i); } // Loop through each super vtable method and see if they are overriden by a method we added to // the hash table. for (size_t j = 0; j < super_vtable_length; ++j) { // Search the hash table to see if we are overidden by any method. ArtMethod* super_method = vtable->GetElementPtrSize(j, image_pointer_size_); MethodNameAndSignatureComparator super_method_name_comparator( super_method->GetInterfaceMethodIfProxy(image_pointer_size_)); uint32_t hash_index = hash_table.FindAndRemove(&super_method_name_comparator); if (hash_index != hash_table.GetNotFoundIndex()) { ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking( hash_index, image_pointer_size_); if (klass->CanAccessMember(super_method->GetDeclaringClass(), super_method->GetAccessFlags())) { if (super_method->IsFinal()) { ThrowLinkageError(klass.Get(), "Method %s overrides final method in class %s", PrettyMethod(virtual_method).c_str(), super_method->GetDeclaringClassDescriptor()); return false; } vtable->SetElementPtrSize(j, virtual_method, image_pointer_size_); virtual_method->SetMethodIndex(j); } else { LOG(WARNING) << "Before Android 4.1, method " << PrettyMethod(virtual_method) << " would have incorrectly overridden the package-private method in " << PrettyDescriptor(super_method->GetDeclaringClassDescriptor()); } } } // Add the non overridden methods at the end. size_t actual_count = super_vtable_length; for (size_t i = 0; i < num_virtual_methods; ++i) { ArtMethod* local_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); size_t method_idx = local_method->GetMethodIndexDuringLinking(); if (method_idx < super_vtable_length && local_method == vtable->GetElementPtrSize(method_idx, image_pointer_size_)) { continue; } vtable->SetElementPtrSize(actual_count, local_method, image_pointer_size_); local_method->SetMethodIndex(actual_count); ++actual_count; } if (!IsUint<16>(actual_count)) { ThrowClassFormatError(klass.Get(), "Too many methods defined on class: %zd", actual_count); return false; } // Shrink vtable if possible CHECK_LE(actual_count, max_count); if (actual_count < max_count) { vtable.Assign(down_cast(vtable->CopyOf(self, actual_count))); if (UNLIKELY(vtable.Get() == nullptr)) { self->AssertPendingOOMException(); return false; } } klass->SetVTable(vtable.Get()); } else { CHECK_EQ(klass.Get(), GetClassRoot(kJavaLangObject)); if (!IsUint<16>(num_virtual_methods)) { ThrowClassFormatError(klass.Get(), "Too many methods: %d", static_cast(num_virtual_methods)); return false; } auto* vtable = AllocPointerArray(self, num_virtual_methods); if (UNLIKELY(vtable == nullptr)) { self->AssertPendingOOMException(); return false; } for (size_t i = 0; i < num_virtual_methods; ++i) { ArtMethod* virtual_method = klass->GetVirtualMethodDuringLinking(i, image_pointer_size_); vtable->SetElementPtrSize(i, virtual_method, image_pointer_size_); virtual_method->SetMethodIndex(i & 0xFFFF); } klass->SetVTable(vtable); } return true; } bool ClassLinker::LinkInterfaceMethods(Thread* self, Handle klass, Handle> interfaces, ArtMethod** out_imt) { StackHandleScope<3> hs(self); Runtime* const runtime = Runtime::Current(); const bool has_superclass = klass->HasSuperClass(); const size_t super_ifcount = has_superclass ? klass->GetSuperClass()->GetIfTableCount() : 0U; const bool have_interfaces = interfaces.Get() != nullptr; const size_t num_interfaces = have_interfaces ? interfaces->GetLength() : klass->NumDirectInterfaces(); const size_t method_size = ArtMethod::ObjectSize(image_pointer_size_); if (num_interfaces == 0) { if (super_ifcount == 0) { // Class implements no interfaces. DCHECK_EQ(klass->GetIfTableCount(), 0); DCHECK(klass->GetIfTable() == nullptr); return true; } // Class implements same interfaces as parent, are any of these not marker interfaces? bool has_non_marker_interface = false; mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable(); for (size_t i = 0; i < super_ifcount; ++i) { if (super_iftable->GetMethodArrayCount(i) > 0) { has_non_marker_interface = true; break; } } // Class just inherits marker interfaces from parent so recycle parent's iftable. if (!has_non_marker_interface) { klass->SetIfTable(super_iftable); return true; } } size_t ifcount = super_ifcount + num_interfaces; for (size_t i = 0; i < num_interfaces; i++) { mirror::Class* interface = have_interfaces ? interfaces->GetWithoutChecks(i) : mirror::Class::GetDirectInterface(self, klass, i); DCHECK(interface != nullptr); if (UNLIKELY(!interface->IsInterface())) { std::string temp; ThrowIncompatibleClassChangeError(klass.Get(), "Class %s implements non-interface class %s", PrettyDescriptor(klass.Get()).c_str(), PrettyDescriptor(interface->GetDescriptor(&temp)).c_str()); return false; } ifcount += interface->GetIfTableCount(); } MutableHandle iftable(hs.NewHandle(AllocIfTable(self, ifcount))); if (UNLIKELY(iftable.Get() == nullptr)) { self->AssertPendingOOMException(); return false; } if (super_ifcount != 0) { mirror::IfTable* super_iftable = klass->GetSuperClass()->GetIfTable(); for (size_t i = 0; i < super_ifcount; i++) { mirror::Class* super_interface = super_iftable->GetInterface(i); iftable->SetInterface(i, super_interface); } } self->AllowThreadSuspension(); // Flatten the interface inheritance hierarchy. size_t idx = super_ifcount; for (size_t i = 0; i < num_interfaces; i++) { mirror::Class* interface = have_interfaces ? interfaces->Get(i) : mirror::Class::GetDirectInterface(self, klass, i); // Check if interface is already in iftable bool duplicate = false; for (size_t j = 0; j < idx; j++) { mirror::Class* existing_interface = iftable->GetInterface(j); if (existing_interface == interface) { duplicate = true; break; } } if (!duplicate) { // Add this non-duplicate interface. iftable->SetInterface(idx++, interface); // Add this interface's non-duplicate super-interfaces. for (int32_t j = 0; j < interface->GetIfTableCount(); j++) { mirror::Class* super_interface = interface->GetIfTable()->GetInterface(j); bool super_duplicate = false; for (size_t k = 0; k < idx; k++) { mirror::Class* existing_interface = iftable->GetInterface(k); if (existing_interface == super_interface) { super_duplicate = true; break; } } if (!super_duplicate) { iftable->SetInterface(idx++, super_interface); } } } } self->AllowThreadSuspension(); // Shrink iftable in case duplicates were found if (idx < ifcount) { DCHECK_NE(num_interfaces, 0U); iftable.Assign(down_cast( iftable->CopyOf(self, idx * mirror::IfTable::kMax))); if (UNLIKELY(iftable.Get() == nullptr)) { self->AssertPendingOOMException(); return false; } ifcount = idx; } else { DCHECK_EQ(idx, ifcount); } klass->SetIfTable(iftable.Get()); // If we're an interface, we don't need the vtable pointers, so we're done. if (klass->IsInterface()) { return true; } // These are allocated on the heap to begin, we then transfer to linear alloc when we re-create // the virtual methods array. // Need to use low 4GB arenas for compiler or else the pointers wont fit in 32 bit method array // during cross compilation. // Use the linear alloc pool since this one is in the low 4gb for the compiler. ArenaStack stack(runtime->GetLinearAlloc()->GetArenaPool()); ScopedArenaAllocator allocator(&stack); ScopedArenaVector miranda_methods(allocator.Adapter()); MutableHandle vtable(hs.NewHandle(klass->GetVTableDuringLinking())); ArtMethod* const unimplemented_method = runtime->GetImtUnimplementedMethod(); ArtMethod* const conflict_method = runtime->GetImtConflictMethod(); // Copy the IMT from the super class if possible. bool extend_super_iftable = false; if (has_superclass) { mirror::Class* super_class = klass->GetSuperClass(); extend_super_iftable = true; if (super_class->ShouldHaveEmbeddedImtAndVTable()) { for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { out_imt[i] = super_class->GetEmbeddedImTableEntry(i, image_pointer_size_); } } else { // No imt in the super class, need to reconstruct from the iftable. mirror::IfTable* if_table = super_class->GetIfTable(); const size_t length = super_class->GetIfTableCount(); for (size_t i = 0; i < length; ++i) { mirror::Class* interface = iftable->GetInterface(i); const size_t num_virtuals = interface->NumVirtualMethods(); const size_t method_array_count = if_table->GetMethodArrayCount(i); DCHECK_EQ(num_virtuals, method_array_count); if (method_array_count == 0) { continue; } auto* method_array = if_table->GetMethodArray(i); for (size_t j = 0; j < num_virtuals; ++j) { auto method = method_array->GetElementPtrSize(j, image_pointer_size_); DCHECK(method != nullptr) << PrettyClass(super_class); if (method->IsMiranda()) { continue; } ArtMethod* interface_method = interface->GetVirtualMethod(j, image_pointer_size_); uint32_t imt_index = interface_method->GetDexMethodIndex() % mirror::Class::kImtSize; auto*& imt_ref = out_imt[imt_index]; if (imt_ref == unimplemented_method) { imt_ref = method; } else if (imt_ref != conflict_method) { imt_ref = conflict_method; } } } } } // Allocate method arrays before since we don't want miss visiting miranda method roots due to // thread suspension. for (size_t i = 0; i < ifcount; ++i) { size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods(); if (num_methods > 0) { const bool is_super = i < super_ifcount; const bool super_interface = is_super && extend_super_iftable; mirror::PointerArray* method_array; if (super_interface) { mirror::IfTable* if_table = klass->GetSuperClass()->GetIfTable(); DCHECK(if_table != nullptr); DCHECK(if_table->GetMethodArray(i) != nullptr); // If we are working on a super interface, try extending the existing method array. method_array = down_cast(if_table->GetMethodArray(i)->Clone(self)); } else { method_array = AllocPointerArray(self, num_methods); } if (UNLIKELY(method_array == nullptr)) { self->AssertPendingOOMException(); return false; } iftable->SetMethodArray(i, method_array); } } auto* old_cause = self->StartAssertNoThreadSuspension( "Copying ArtMethods for LinkInterfaceMethods"); for (size_t i = 0; i < ifcount; ++i) { size_t num_methods = iftable->GetInterface(i)->NumVirtualMethods(); if (num_methods > 0) { StackHandleScope<2> hs2(self); const bool is_super = i < super_ifcount; const bool super_interface = is_super && extend_super_iftable; auto method_array(hs2.NewHandle(iftable->GetMethodArray(i))); ArtMethod* input_virtual_methods = nullptr; Handle input_vtable_array = NullHandle(); int32_t input_array_length = 0; if (super_interface) { // We are overwriting a super class interface, try to only virtual methods instead of the // whole vtable. input_virtual_methods = klass->GetVirtualMethodsPtr(); input_array_length = klass->NumVirtualMethods(); } else { // A new interface, we need the whole vtable in case a new interface method is implemented // in the whole superclass. input_vtable_array = vtable; input_array_length = input_vtable_array->GetLength(); } if (input_array_length == 0) { // If the added virtual methods is empty, do nothing. DCHECK(super_interface); continue; } for (size_t j = 0; j < num_methods; ++j) { auto* interface_method = iftable->GetInterface(i)->GetVirtualMethod( j, image_pointer_size_); MethodNameAndSignatureComparator interface_name_comparator( interface_method->GetInterfaceMethodIfProxy(image_pointer_size_)); int32_t k; // For each method listed in the interface's method list, find the // matching method in our class's method list. We want to favor the // subclass over the superclass, which just requires walking // back from the end of the vtable. (This only matters if the // superclass defines a private method and this class redefines // it -- otherwise it would use the same vtable slot. In .dex files // those don't end up in the virtual method table, so it shouldn't // matter which direction we go. We walk it backward anyway.) for (k = input_array_length - 1; k >= 0; --k) { ArtMethod* vtable_method = input_virtual_methods != nullptr ? reinterpret_cast( reinterpret_cast(input_virtual_methods) + method_size * k) : input_vtable_array->GetElementPtrSize(k, image_pointer_size_); ArtMethod* vtable_method_for_name_comparison = vtable_method->GetInterfaceMethodIfProxy(image_pointer_size_); if (interface_name_comparator.HasSameNameAndSignature( vtable_method_for_name_comparison)) { if (!vtable_method->IsAbstract() && !vtable_method->IsPublic()) { // Must do EndAssertNoThreadSuspension before throw since the throw can cause // allocations. self->EndAssertNoThreadSuspension(old_cause); ThrowIllegalAccessError(klass.Get(), "Method '%s' implementing interface method '%s' is not public", PrettyMethod(vtable_method).c_str(), PrettyMethod(interface_method).c_str()); return false; } method_array->SetElementPtrSize(j, vtable_method, image_pointer_size_); // Place method in imt if entry is empty, place conflict otherwise. uint32_t imt_index = interface_method->GetDexMethodIndex() % mirror::Class::kImtSize; auto** imt_ref = &out_imt[imt_index]; if (*imt_ref == unimplemented_method) { *imt_ref = vtable_method; } else if (*imt_ref != conflict_method) { // If we are not a conflict and we have the same signature and name as the imt entry, // it must be that we overwrote a superclass vtable entry. MethodNameAndSignatureComparator imt_comparator( (*imt_ref)->GetInterfaceMethodIfProxy(image_pointer_size_)); *imt_ref = imt_comparator.HasSameNameAndSignature(vtable_method_for_name_comparison) ? vtable_method : conflict_method; } break; } } if (k < 0 && !super_interface) { ArtMethod* miranda_method = nullptr; for (auto& mir_method : miranda_methods) { if (interface_name_comparator.HasSameNameAndSignature(mir_method)) { miranda_method = mir_method; break; } } if (miranda_method == nullptr) { miranda_method = reinterpret_cast(allocator.Alloc(method_size)); CHECK(miranda_method != nullptr); // Point the interface table at a phantom slot. new(miranda_method) ArtMethod(*interface_method, image_pointer_size_); miranda_methods.push_back(miranda_method); } method_array->SetElementPtrSize(j, miranda_method, image_pointer_size_); } } } } if (!miranda_methods.empty()) { const size_t old_method_count = klass->NumVirtualMethods(); const size_t new_method_count = old_method_count + miranda_methods.size(); // Attempt to realloc to save RAM if possible. ArtMethod* old_virtuals = klass->GetVirtualMethodsPtr(); // The Realloced virtual methods aren't visiblef from the class roots, so there is no issue // where GCs could attempt to mark stale pointers due to memcpy. And since we overwrite the // realloced memory with out->CopyFrom, we are guaranteed to have objects in the to space since // CopyFrom has internal read barriers. auto* virtuals = reinterpret_cast(runtime->GetLinearAlloc()->Realloc( self, old_virtuals, old_method_count * method_size, new_method_count * method_size)); if (UNLIKELY(virtuals == nullptr)) { self->AssertPendingOOMException(); return false; } ScopedArenaUnorderedMap move_table(allocator.Adapter()); if (virtuals != old_virtuals) { // Maps from heap allocated miranda method to linear alloc miranda method. StrideIterator out(reinterpret_cast(virtuals), method_size); // Copy over the old methods + miranda methods. for (auto& m : klass->GetVirtualMethods(image_pointer_size_)) { move_table.emplace(&m, &*out); // The CopyFrom is only necessary to not miss read barriers since Realloc won't do read // barriers when it copies. out->CopyFrom(&m, image_pointer_size_); ++out; } } StrideIterator out( reinterpret_cast(virtuals) + old_method_count * method_size, method_size); // Copy over miranda methods before copying vtable since CopyOf may cause thread suspension and // we want the roots of the miranda methods to get visited. for (ArtMethod* mir_method : miranda_methods) { out->CopyFrom(mir_method, image_pointer_size_); out->SetAccessFlags(out->GetAccessFlags() | kAccMiranda); move_table.emplace(mir_method, &*out); ++out; } UpdateClassVirtualMethods(klass.Get(), virtuals, new_method_count); // Done copying methods, they are all roots in the class now, so we can end the no thread // suspension assert. self->EndAssertNoThreadSuspension(old_cause); const size_t old_vtable_count = vtable->GetLength(); const size_t new_vtable_count = old_vtable_count + miranda_methods.size(); miranda_methods.clear(); vtable.Assign(down_cast(vtable->CopyOf(self, new_vtable_count))); if (UNLIKELY(vtable.Get() == nullptr)) { self->AssertPendingOOMException(); return false; } out = StrideIterator( reinterpret_cast(virtuals) + old_method_count * method_size, method_size); size_t vtable_pos = old_vtable_count; for (size_t i = old_method_count; i < new_method_count; ++i) { // Leave the declaring class alone as type indices are relative to it out->SetMethodIndex(0xFFFF & vtable_pos); vtable->SetElementPtrSize(vtable_pos, &*out, image_pointer_size_); ++out; ++vtable_pos; } CHECK_EQ(vtable_pos, new_vtable_count); // Update old vtable methods. for (size_t i = 0; i < old_vtable_count; ++i) { auto* m = vtable->GetElementPtrSize(i, image_pointer_size_); DCHECK(m != nullptr) << PrettyClass(klass.Get()); auto it = move_table.find(m); if (it != move_table.end()) { auto* new_m = it->second; DCHECK(new_m != nullptr) << PrettyClass(klass.Get()); vtable->SetElementPtrSize(i, new_m, image_pointer_size_); } } klass->SetVTable(vtable.Get()); // Go fix up all the stale miranda pointers. for (size_t i = 0; i < ifcount; ++i) { for (size_t j = 0, count = iftable->GetMethodArrayCount(i); j < count; ++j) { auto* method_array = iftable->GetMethodArray(i); auto* m = method_array->GetElementPtrSize(j, image_pointer_size_); DCHECK(m != nullptr) << PrettyClass(klass.Get()); auto it = move_table.find(m); if (it != move_table.end()) { auto* new_m = it->second; DCHECK(new_m != nullptr) << PrettyClass(klass.Get()); method_array->SetElementPtrSize(j, new_m, image_pointer_size_); } } } // Fix up IMT in case it has any miranda methods in it. for (size_t i = 0; i < mirror::Class::kImtSize; ++i) { auto it = move_table.find(out_imt[i]); if (it != move_table.end()) { out_imt[i] = it->second; } } // Check that there are no stale methods are in the dex cache array. if (kIsDebugBuild) { auto* resolved_methods = klass->GetDexCache()->GetResolvedMethods(); for (size_t i = 0, count = resolved_methods->GetLength(); i < count; ++i) { auto* m = resolved_methods->GetElementPtrSize(i, image_pointer_size_); CHECK(move_table.find(m) == move_table.end()) << PrettyMethod(m); } } // Put some random garbage in old virtuals to help find stale pointers. if (virtuals != old_virtuals) { memset(old_virtuals, 0xFEu, ArtMethod::ObjectSize(image_pointer_size_) * old_method_count); } } else { self->EndAssertNoThreadSuspension(old_cause); } if (kIsDebugBuild) { auto* check_vtable = klass->GetVTableDuringLinking(); for (int i = 0; i < check_vtable->GetLength(); ++i) { CHECK(check_vtable->GetElementPtrSize(i, image_pointer_size_) != nullptr); } } return true; } bool ClassLinker::LinkInstanceFields(Thread* self, Handle klass) { CHECK(klass.Get() != nullptr); return LinkFields(self, klass, false, nullptr); } bool ClassLinker::LinkStaticFields(Thread* self, Handle klass, size_t* class_size) { CHECK(klass.Get() != nullptr); return LinkFields(self, klass, true, class_size); } struct LinkFieldsComparator { explicit LinkFieldsComparator() SHARED_LOCKS_REQUIRED(Locks::mutator_lock_) { } // No thread safety analysis as will be called from STL. Checked lock held in constructor. bool operator()(ArtField* field1, ArtField* field2) NO_THREAD_SAFETY_ANALYSIS { // First come reference fields, then 64-bit, then 32-bit, and then 16-bit, then finally 8-bit. Primitive::Type type1 = field1->GetTypeAsPrimitiveType(); Primitive::Type type2 = field2->GetTypeAsPrimitiveType(); if (type1 != type2) { if (type1 == Primitive::kPrimNot) { // Reference always goes first. return true; } if (type2 == Primitive::kPrimNot) { // Reference always goes first. return false; } size_t size1 = Primitive::ComponentSize(type1); size_t size2 = Primitive::ComponentSize(type2); if (size1 != size2) { // Larger primitive types go first. return size1 > size2; } // Primitive types differ but sizes match. Arbitrarily order by primitive type. return type1 < type2; } // Same basic group? Then sort by dex field index. This is guaranteed to be sorted // by name and for equal names by type id index. // NOTE: This works also for proxies. Their static fields are assigned appropriate indexes. return field1->GetDexFieldIndex() < field2->GetDexFieldIndex(); } }; bool ClassLinker::LinkFields(Thread* self, Handle klass, bool is_static, size_t* class_size) { self->AllowThreadSuspension(); const size_t num_fields = is_static ? klass->NumStaticFields() : klass->NumInstanceFields(); ArtField* const fields = is_static ? klass->GetSFields() : klass->GetIFields(); // Initialize field_offset MemberOffset field_offset(0); if (is_static) { field_offset = klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_); } else { mirror::Class* super_class = klass->GetSuperClass(); if (super_class != nullptr) { CHECK(super_class->IsResolved()) << PrettyClass(klass.Get()) << " " << PrettyClass(super_class); field_offset = MemberOffset(super_class->GetObjectSize()); } } CHECK_EQ(num_fields == 0, fields == nullptr) << PrettyClass(klass.Get()); // we want a relatively stable order so that adding new fields // minimizes disruption of C++ version such as Class and Method. std::deque grouped_and_sorted_fields; const char* old_no_suspend_cause = self->StartAssertNoThreadSuspension( "Naked ArtField references in deque"); for (size_t i = 0; i < num_fields; i++) { grouped_and_sorted_fields.push_back(&fields[i]); } std::sort(grouped_and_sorted_fields.begin(), grouped_and_sorted_fields.end(), LinkFieldsComparator()); // References should be at the front. size_t current_field = 0; size_t num_reference_fields = 0; FieldGaps gaps; for (; current_field < num_fields; current_field++) { ArtField* field = grouped_and_sorted_fields.front(); Primitive::Type type = field->GetTypeAsPrimitiveType(); bool isPrimitive = type != Primitive::kPrimNot; if (isPrimitive) { break; // past last reference, move on to the next phase } if (UNLIKELY(!IsAligned)>( field_offset.Uint32Value()))) { MemberOffset old_offset = field_offset; field_offset = MemberOffset(RoundUp(field_offset.Uint32Value(), 4)); AddFieldGap(old_offset.Uint32Value(), field_offset.Uint32Value(), &gaps); } DCHECK(IsAligned)>(field_offset.Uint32Value())); grouped_and_sorted_fields.pop_front(); num_reference_fields++; field->SetOffset(field_offset); field_offset = MemberOffset(field_offset.Uint32Value() + sizeof(mirror::HeapReference)); } // Gaps are stored as a max heap which means that we must shuffle from largest to smallest // otherwise we could end up with suboptimal gap fills. ShuffleForward<8>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); ShuffleForward<4>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); ShuffleForward<2>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); ShuffleForward<1>(¤t_field, &field_offset, &grouped_and_sorted_fields, &gaps); CHECK(grouped_and_sorted_fields.empty()) << "Missed " << grouped_and_sorted_fields.size() << " fields."; self->EndAssertNoThreadSuspension(old_no_suspend_cause); // We lie to the GC about the java.lang.ref.Reference.referent field, so it doesn't scan it. if (!is_static && klass->DescriptorEquals("Ljava/lang/ref/Reference;")) { // We know there are no non-reference fields in the Reference classes, and we know // that 'referent' is alphabetically last, so this is easy... CHECK_EQ(num_reference_fields, num_fields) << PrettyClass(klass.Get()); CHECK_STREQ(fields[num_fields - 1].GetName(), "referent") << PrettyClass(klass.Get()); --num_reference_fields; } size_t size = field_offset.Uint32Value(); // Update klass if (is_static) { klass->SetNumReferenceStaticFields(num_reference_fields); *class_size = size; } else { klass->SetNumReferenceInstanceFields(num_reference_fields); if (!klass->IsVariableSize()) { std::string temp; DCHECK_GE(size, sizeof(mirror::Object)) << klass->GetDescriptor(&temp); size_t previous_size = klass->GetObjectSize(); if (previous_size != 0) { // Make sure that we didn't originally have an incorrect size. CHECK_EQ(previous_size, size) << klass->GetDescriptor(&temp); } klass->SetObjectSize(size); } } if (kIsDebugBuild) { // Make sure that the fields array is ordered by name but all reference // offsets are at the beginning as far as alignment allows. MemberOffset start_ref_offset = is_static ? klass->GetFirstReferenceStaticFieldOffsetDuringLinking(image_pointer_size_) : klass->GetFirstReferenceInstanceFieldOffset(); MemberOffset end_ref_offset(start_ref_offset.Uint32Value() + num_reference_fields * sizeof(mirror::HeapReference)); MemberOffset current_ref_offset = start_ref_offset; for (size_t i = 0; i < num_fields; i++) { ArtField* field = &fields[i]; VLOG(class_linker) << "LinkFields: " << (is_static ? "static" : "instance") << " class=" << PrettyClass(klass.Get()) << " field=" << PrettyField(field) << " offset=" << field->GetOffset(); if (i != 0) { ArtField* const prev_field = &fields[i - 1]; // NOTE: The field names can be the same. This is not possible in the Java language // but it's valid Java/dex bytecode and for example proguard can generate such bytecode. CHECK_LE(strcmp(prev_field->GetName(), field->GetName()), 0); } Primitive::Type type = field->GetTypeAsPrimitiveType(); bool is_primitive = type != Primitive::kPrimNot; if (klass->DescriptorEquals("Ljava/lang/ref/Reference;") && strcmp("referent", field->GetName()) == 0) { is_primitive = true; // We lied above, so we have to expect a lie here. } MemberOffset offset = field->GetOffsetDuringLinking(); if (is_primitive) { if (offset.Uint32Value() < end_ref_offset.Uint32Value()) { // Shuffled before references. size_t type_size = Primitive::ComponentSize(type); CHECK_LT(type_size, sizeof(mirror::HeapReference)); CHECK_LT(offset.Uint32Value(), start_ref_offset.Uint32Value()); CHECK_LE(offset.Uint32Value() + type_size, start_ref_offset.Uint32Value()); CHECK(!IsAligned)>(offset.Uint32Value())); } } else { CHECK_EQ(current_ref_offset.Uint32Value(), offset.Uint32Value()); current_ref_offset = MemberOffset(current_ref_offset.Uint32Value() + sizeof(mirror::HeapReference)); } } CHECK_EQ(current_ref_offset.Uint32Value(), end_ref_offset.Uint32Value()); } return true; } // Set the bitmap of reference instance field offsets. void ClassLinker::CreateReferenceInstanceOffsets(Handle klass) { uint32_t reference_offsets = 0; mirror::Class* super_class = klass->GetSuperClass(); // Leave the reference offsets as 0 for mirror::Object (the class field is handled specially). if (super_class != nullptr) { reference_offsets = super_class->GetReferenceInstanceOffsets(); // Compute reference offsets unless our superclass overflowed. if (reference_offsets != mirror::Class::kClassWalkSuper) { size_t num_reference_fields = klass->NumReferenceInstanceFieldsDuringLinking(); if (num_reference_fields != 0u) { // All of the fields that contain object references are guaranteed be grouped in memory // starting at an appropriately aligned address after super class object data. uint32_t start_offset = RoundUp(super_class->GetObjectSize(), sizeof(mirror::HeapReference)); uint32_t start_bit = (start_offset - mirror::kObjectHeaderSize) / sizeof(mirror::HeapReference); if (start_bit + num_reference_fields > 32) { reference_offsets = mirror::Class::kClassWalkSuper; } else { reference_offsets |= (0xffffffffu << start_bit) & (0xffffffffu >> (32 - (start_bit + num_reference_fields))); } } } } klass->SetReferenceInstanceOffsets(reference_offsets); } mirror::String* ClassLinker::ResolveString(const DexFile& dex_file, uint32_t string_idx, Handle dex_cache) { DCHECK(dex_cache.Get() != nullptr); mirror::String* resolved = dex_cache->GetResolvedString(string_idx); if (resolved != nullptr) { return resolved; } uint32_t utf16_length; const char* utf8_data = dex_file.StringDataAndUtf16LengthByIdx(string_idx, &utf16_length); mirror::String* string = intern_table_->InternStrong(utf16_length, utf8_data); dex_cache->SetResolvedString(string_idx, string); return string; } mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file, uint16_t type_idx, mirror::Class* referrer) { StackHandleScope<2> hs(Thread::Current()); Handle dex_cache(hs.NewHandle(referrer->GetDexCache())); Handle class_loader(hs.NewHandle(referrer->GetClassLoader())); return ResolveType(dex_file, type_idx, dex_cache, class_loader); } mirror::Class* ClassLinker::ResolveType(const DexFile& dex_file, uint16_t type_idx, Handle dex_cache, Handle class_loader) { DCHECK(dex_cache.Get() != nullptr); mirror::Class* resolved = dex_cache->GetResolvedType(type_idx); if (resolved == nullptr) { Thread* self = Thread::Current(); const char* descriptor = dex_file.StringByTypeIdx(type_idx); resolved = FindClass(self, descriptor, class_loader); if (resolved != nullptr) { // TODO: we used to throw here if resolved's class loader was not the // boot class loader. This was to permit different classes with the // same name to be loaded simultaneously by different loaders dex_cache->SetResolvedType(type_idx, resolved); } else { CHECK(self->IsExceptionPending()) << "Expected pending exception for failed resolution of: " << descriptor; // Convert a ClassNotFoundException to a NoClassDefFoundError. StackHandleScope<1> hs(self); Handle cause(hs.NewHandle(self->GetException())); if (cause->InstanceOf(GetClassRoot(kJavaLangClassNotFoundException))) { DCHECK(resolved == nullptr); // No Handle needed to preserve resolved. self->ClearException(); ThrowNoClassDefFoundError("Failed resolution of: %s", descriptor); self->GetException()->SetCause(cause.Get()); } } } DCHECK((resolved == nullptr) || resolved->IsResolved() || resolved->IsErroneous()) << PrettyDescriptor(resolved) << " " << resolved->GetStatus(); return resolved; } ArtMethod* ClassLinker::ResolveMethod(const DexFile& dex_file, uint32_t method_idx, Handle dex_cache, Handle class_loader, ArtMethod* referrer, InvokeType type) { DCHECK(dex_cache.Get() != nullptr); // Check for hit in the dex cache. ArtMethod* resolved = dex_cache->GetResolvedMethod(method_idx, image_pointer_size_); if (resolved != nullptr && !resolved->IsRuntimeMethod()) { DCHECK(resolved->GetDeclaringClassUnchecked() != nullptr) << resolved->GetDexMethodIndex(); return resolved; } // Fail, get the declaring class. const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); mirror::Class* klass = ResolveType(dex_file, method_id.class_idx_, dex_cache, class_loader); if (klass == nullptr) { DCHECK(Thread::Current()->IsExceptionPending()); return nullptr; } // Scan using method_idx, this saves string compares but will only hit for matching dex // caches/files. switch (type) { case kDirect: // Fall-through. case kStatic: resolved = klass->FindDirectMethod(dex_cache.Get(), method_idx, image_pointer_size_); DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr); break; case kInterface: resolved = klass->FindInterfaceMethod(dex_cache.Get(), method_idx, image_pointer_size_); DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface()); break; case kSuper: // Fall-through. case kVirtual: resolved = klass->FindVirtualMethod(dex_cache.Get(), method_idx, image_pointer_size_); break; default: LOG(FATAL) << "Unreachable - invocation type: " << type; UNREACHABLE(); } if (resolved == nullptr) { // Search by name, which works across dex files. const char* name = dex_file.StringDataByIdx(method_id.name_idx_); const Signature signature = dex_file.GetMethodSignature(method_id); switch (type) { case kDirect: // Fall-through. case kStatic: resolved = klass->FindDirectMethod(name, signature, image_pointer_size_); DCHECK(resolved == nullptr || resolved->GetDeclaringClassUnchecked() != nullptr); break; case kInterface: resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); DCHECK(resolved == nullptr || resolved->GetDeclaringClass()->IsInterface()); break; case kSuper: // Fall-through. case kVirtual: resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); break; } } // If we found a method, check for incompatible class changes. if (LIKELY(resolved != nullptr && !resolved->CheckIncompatibleClassChange(type))) { // Be a good citizen and update the dex cache to speed subsequent calls. dex_cache->SetResolvedMethod(method_idx, resolved, image_pointer_size_); return resolved; } else { // If we had a method, it's an incompatible-class-change error. if (resolved != nullptr) { ThrowIncompatibleClassChangeError(type, resolved->GetInvokeType(), resolved, referrer); } else { // We failed to find the method which means either an access error, an incompatible class // change, or no such method. First try to find the method among direct and virtual methods. const char* name = dex_file.StringDataByIdx(method_id.name_idx_); const Signature signature = dex_file.GetMethodSignature(method_id); switch (type) { case kDirect: case kStatic: resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); // Note: kDirect and kStatic are also mutually exclusive, but in that case we would // have had a resolved method before, which triggers the "true" branch above. break; case kInterface: case kVirtual: case kSuper: resolved = klass->FindDirectMethod(name, signature, image_pointer_size_); break; } // If we found something, check that it can be accessed by the referrer. bool exception_generated = false; if (resolved != nullptr && referrer != nullptr) { mirror::Class* methods_class = resolved->GetDeclaringClass(); mirror::Class* referring_class = referrer->GetDeclaringClass(); if (!referring_class->CanAccess(methods_class)) { ThrowIllegalAccessErrorClassForMethodDispatch(referring_class, methods_class, resolved, type); exception_generated = true; } else if (!referring_class->CanAccessMember(methods_class, resolved->GetAccessFlags())) { ThrowIllegalAccessErrorMethod(referring_class, resolved); exception_generated = true; } } if (!exception_generated) { // Otherwise, throw an IncompatibleClassChangeError if we found something, and check // interface methods and throw if we find the method there. If we find nothing, throw a // NoSuchMethodError. switch (type) { case kDirect: case kStatic: if (resolved != nullptr) { ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer); } else { resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); if (resolved != nullptr) { ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer); } else { ThrowNoSuchMethodError(type, klass, name, signature); } } break; case kInterface: if (resolved != nullptr) { ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); } else { resolved = klass->FindVirtualMethod(name, signature, image_pointer_size_); if (resolved != nullptr) { ThrowIncompatibleClassChangeError(type, kVirtual, resolved, referrer); } else { ThrowNoSuchMethodError(type, klass, name, signature); } } break; case kSuper: if (resolved != nullptr) { ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); } else { ThrowNoSuchMethodError(type, klass, name, signature); } break; case kVirtual: if (resolved != nullptr) { ThrowIncompatibleClassChangeError(type, kDirect, resolved, referrer); } else { resolved = klass->FindInterfaceMethod(name, signature, image_pointer_size_); if (resolved != nullptr) { ThrowIncompatibleClassChangeError(type, kInterface, resolved, referrer); } else { ThrowNoSuchMethodError(type, klass, name, signature); } } break; } } } Thread::Current()->AssertPendingException(); return nullptr; } } ArtField* ClassLinker::ResolveField(const DexFile& dex_file, uint32_t field_idx, Handle dex_cache, Handle class_loader, bool is_static) { DCHECK(dex_cache.Get() != nullptr); ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_); if (resolved != nullptr) { return resolved; } const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); Thread* const self = Thread::Current(); StackHandleScope<1> hs(self); Handle klass( hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader))); if (klass.Get() == nullptr) { DCHECK(Thread::Current()->IsExceptionPending()); return nullptr; } if (is_static) { resolved = mirror::Class::FindStaticField(self, klass, dex_cache.Get(), field_idx); } else { resolved = klass->FindInstanceField(dex_cache.Get(), field_idx); } if (resolved == nullptr) { const char* name = dex_file.GetFieldName(field_id); const char* type = dex_file.GetFieldTypeDescriptor(field_id); if (is_static) { resolved = mirror::Class::FindStaticField(self, klass, name, type); } else { resolved = klass->FindInstanceField(name, type); } if (resolved == nullptr) { ThrowNoSuchFieldError(is_static ? "static " : "instance ", klass.Get(), type, name); return nullptr; } } dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_); return resolved; } ArtField* ClassLinker::ResolveFieldJLS(const DexFile& dex_file, uint32_t field_idx, Handle dex_cache, Handle class_loader) { DCHECK(dex_cache.Get() != nullptr); ArtField* resolved = dex_cache->GetResolvedField(field_idx, image_pointer_size_); if (resolved != nullptr) { return resolved; } const DexFile::FieldId& field_id = dex_file.GetFieldId(field_idx); Thread* self = Thread::Current(); StackHandleScope<1> hs(self); Handle klass( hs.NewHandle(ResolveType(dex_file, field_id.class_idx_, dex_cache, class_loader))); if (klass.Get() == nullptr) { DCHECK(Thread::Current()->IsExceptionPending()); return nullptr; } StringPiece name(dex_file.StringDataByIdx(field_id.name_idx_)); StringPiece type(dex_file.StringDataByIdx( dex_file.GetTypeId(field_id.type_idx_).descriptor_idx_)); resolved = mirror::Class::FindField(self, klass, name, type); if (resolved != nullptr) { dex_cache->SetResolvedField(field_idx, resolved, image_pointer_size_); } else { ThrowNoSuchFieldError("", klass.Get(), type, name); } return resolved; } const char* ClassLinker::MethodShorty(uint32_t method_idx, ArtMethod* referrer, uint32_t* length) { mirror::Class* declaring_class = referrer->GetDeclaringClass(); mirror::DexCache* dex_cache = declaring_class->GetDexCache(); const DexFile& dex_file = *dex_cache->GetDexFile(); const DexFile::MethodId& method_id = dex_file.GetMethodId(method_idx); return dex_file.GetMethodShorty(method_id, length); } void ClassLinker::DumpAllClasses(int flags) { if (dex_cache_image_class_lookup_required_) { MoveImageClassesToClassTable(); } // TODO: at the time this was written, it wasn't safe to call PrettyField with the ClassLinker // lock held, because it might need to resolve a field's type, which would try to take the lock. std::vector all_classes; { ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); for (GcRoot& it : class_table_) { all_classes.push_back(it.Read()); } } for (size_t i = 0; i < all_classes.size(); ++i) { all_classes[i]->DumpClass(std::cerr, flags); } } static OatFile::OatMethod CreateOatMethod(const void* code) { CHECK(code != nullptr); const uint8_t* base = reinterpret_cast(code); // Base of data points at code. base -= sizeof(void*); // Move backward so that code_offset != 0. const uint32_t code_offset = sizeof(void*); return OatFile::OatMethod(base, code_offset); } bool ClassLinker::IsQuickResolutionStub(const void* entry_point) const { return (entry_point == GetQuickResolutionStub()) || (quick_resolution_trampoline_ == entry_point); } bool ClassLinker::IsQuickToInterpreterBridge(const void* entry_point) const { return (entry_point == GetQuickToInterpreterBridge()) || (quick_to_interpreter_bridge_trampoline_ == entry_point); } bool ClassLinker::IsQuickGenericJniStub(const void* entry_point) const { return (entry_point == GetQuickGenericJniStub()) || (quick_generic_jni_trampoline_ == entry_point); } const void* ClassLinker::GetRuntimeQuickGenericJniStub() const { return GetQuickGenericJniStub(); } void ClassLinker::SetEntryPointsToCompiledCode(ArtMethod* method, const void* method_code) const { OatFile::OatMethod oat_method = CreateOatMethod(method_code); oat_method.LinkMethod(method); method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); } void ClassLinker::SetEntryPointsToInterpreter(ArtMethod* method) const { if (!method->IsNative()) { method->SetEntryPointFromInterpreter(artInterpreterToInterpreterBridge); method->SetEntryPointFromQuickCompiledCode(GetQuickToInterpreterBridge()); } else { const void* quick_method_code = GetQuickGenericJniStub(); OatFile::OatMethod oat_method = CreateOatMethod(quick_method_code); oat_method.LinkMethod(method); method->SetEntryPointFromInterpreter(artInterpreterToCompiledCodeBridge); } } void ClassLinker::DumpForSigQuit(std::ostream& os) { Thread* self = Thread::Current(); if (dex_cache_image_class_lookup_required_) { ScopedObjectAccess soa(self); MoveImageClassesToClassTable(); } ReaderMutexLock mu(self, *Locks::classlinker_classes_lock_); os << "Zygote loaded classes=" << pre_zygote_class_table_.Size() << " post zygote classes=" << class_table_.Size() << "\n"; } size_t ClassLinker::NumLoadedClasses() { if (dex_cache_image_class_lookup_required_) { MoveImageClassesToClassTable(); } ReaderMutexLock mu(Thread::Current(), *Locks::classlinker_classes_lock_); // Only return non zygote classes since these are the ones which apps which care about. return class_table_.Size(); } pid_t ClassLinker::GetClassesLockOwner() { return Locks::classlinker_classes_lock_->GetExclusiveOwnerTid(); } pid_t ClassLinker::GetDexLockOwner() { return dex_lock_.GetExclusiveOwnerTid(); } void ClassLinker::SetClassRoot(ClassRoot class_root, mirror::Class* klass) { DCHECK(!init_done_); DCHECK(klass != nullptr); DCHECK(klass->GetClassLoader() == nullptr); mirror::ObjectArray* class_roots = class_roots_.Read(); DCHECK(class_roots != nullptr); DCHECK(class_roots->Get(class_root) == nullptr); class_roots->Set(class_root, klass); } const char* ClassLinker::GetClassRootDescriptor(ClassRoot class_root) { static const char* class_roots_descriptors[] = { "Ljava/lang/Class;", "Ljava/lang/Object;", "[Ljava/lang/Class;", "[Ljava/lang/Object;", "Ljava/lang/String;", "Ljava/lang/DexCache;", "Ljava/lang/ref/Reference;", "Ljava/lang/reflect/Constructor;", "Ljava/lang/reflect/Field;", "Ljava/lang/reflect/Method;", "Ljava/lang/reflect/Proxy;", "[Ljava/lang/String;", "[Ljava/lang/reflect/Constructor;", "[Ljava/lang/reflect/Field;", "[Ljava/lang/reflect/Method;", "Ljava/lang/ClassLoader;", "Ljava/lang/Throwable;", "Ljava/lang/ClassNotFoundException;", "Ljava/lang/StackTraceElement;", "Z", "B", "C", "D", "F", "I", "J", "S", "V", "[Z", "[B", "[C", "[D", "[F", "[I", "[J", "[S", "[Ljava/lang/StackTraceElement;", }; static_assert(arraysize(class_roots_descriptors) == size_t(kClassRootsMax), "Mismatch between class descriptors and class-root enum"); const char* descriptor = class_roots_descriptors[class_root]; CHECK(descriptor != nullptr); return descriptor; } std::size_t ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot& root) const { std::string temp; return ComputeModifiedUtf8Hash(root.Read()->GetDescriptor(&temp)); } bool ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot& a, const GcRoot& b) const { if (a.Read()->GetClassLoader() != b.Read()->GetClassLoader()) { return false; } std::string temp; return a.Read()->DescriptorEquals(b.Read()->GetDescriptor(&temp)); } std::size_t ClassLinker::ClassDescriptorHashEquals::operator()( const std::pair& element) const { return ComputeModifiedUtf8Hash(element.first); } bool ClassLinker::ClassDescriptorHashEquals::operator()( const GcRoot& a, const std::pair& b) const { if (a.Read()->GetClassLoader() != b.second) { return false; } return a.Read()->DescriptorEquals(b.first); } bool ClassLinker::ClassDescriptorHashEquals::operator()(const GcRoot& a, const char* descriptor) const { return a.Read()->DescriptorEquals(descriptor); } std::size_t ClassLinker::ClassDescriptorHashEquals::operator()(const char* descriptor) const { return ComputeModifiedUtf8Hash(descriptor); } bool ClassLinker::MayBeCalledWithDirectCodePointer(ArtMethod* m) { if (Runtime::Current()->UseJit()) { // JIT can have direct code pointers from any method to any other method. return true; } // Non-image methods don't use direct code pointer. if (!m->GetDeclaringClass()->IsBootStrapClassLoaded()) { return false; } if (m->IsPrivate()) { // The method can only be called inside its own oat file. Therefore it won't be called using // its direct code if the oat file has been compiled in PIC mode. const DexFile& dex_file = m->GetDeclaringClass()->GetDexFile(); const OatFile::OatDexFile* oat_dex_file = dex_file.GetOatDexFile(); if (oat_dex_file == nullptr) { // No oat file: the method has not been compiled. return false; } const OatFile* oat_file = oat_dex_file->GetOatFile(); return oat_file != nullptr && !oat_file->IsPic(); } else { // The method can be called outside its own oat file. Therefore it won't be called using its // direct code pointer only if all loaded oat files have been compiled in PIC mode. ReaderMutexLock mu(Thread::Current(), dex_lock_); for (const OatFile* oat_file : oat_files_) { if (!oat_file->IsPic()) { return true; } } return false; } } jobject ClassLinker::CreatePathClassLoader(Thread* self, std::vector& dex_files) { // SOAAlreadyRunnable is protected, and we need something to add a global reference. // We could move the jobject to the callers, but all call-sites do this... ScopedObjectAccessUnchecked soa(self); // Register the dex files. for (const DexFile* dex_file : dex_files) { RegisterDexFile(*dex_file); } // For now, create a libcore-level DexFile for each ART DexFile. This "explodes" multidex. StackHandleScope<10> hs(self); ArtField* dex_elements_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList_dexElements); mirror::Class* dex_elements_class = dex_elements_field->GetType(); DCHECK(dex_elements_class != nullptr); DCHECK(dex_elements_class->IsArrayClass()); Handle> h_dex_elements(hs.NewHandle( mirror::ObjectArray::Alloc(self, dex_elements_class, dex_files.size()))); Handle h_dex_element_class = hs.NewHandle(dex_elements_class->GetComponentType()); ArtField* element_file_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexPathList__Element_dexFile); DCHECK_EQ(h_dex_element_class.Get(), element_file_field->GetDeclaringClass()); ArtField* cookie_field = soa.DecodeField(WellKnownClasses::dalvik_system_DexFile_cookie); DCHECK_EQ(cookie_field->GetDeclaringClass(), element_file_field->GetType()); // Fill the elements array. int32_t index = 0; for (const DexFile* dex_file : dex_files) { StackHandleScope<3> hs2(self); Handle h_long_array = hs2.NewHandle(mirror::LongArray::Alloc(self, 1)); DCHECK(h_long_array.Get() != nullptr); h_long_array->Set(0, reinterpret_cast(dex_file)); Handle h_dex_file = hs2.NewHandle( cookie_field->GetDeclaringClass()->AllocObject(self)); DCHECK(h_dex_file.Get() != nullptr); cookie_field->SetObject(h_dex_file.Get(), h_long_array.Get()); Handle h_element = hs2.NewHandle(h_dex_element_class->AllocObject(self)); DCHECK(h_element.Get() != nullptr); element_file_field->SetObject(h_element.Get(), h_dex_file.Get()); h_dex_elements->Set(index, h_element.Get()); index++; } DCHECK_EQ(index, h_dex_elements->GetLength()); // Create DexPathList. Handle h_dex_path_list = hs.NewHandle( dex_elements_field->GetDeclaringClass()->AllocObject(self)); DCHECK(h_dex_path_list.Get() != nullptr); // Set elements. dex_elements_field->SetObject(h_dex_path_list.Get(), h_dex_elements.Get()); // Create PathClassLoader. Handle h_path_class_class = hs.NewHandle( soa.Decode(WellKnownClasses::dalvik_system_PathClassLoader)); Handle h_path_class_loader = hs.NewHandle( h_path_class_class->AllocObject(self)); DCHECK(h_path_class_loader.Get() != nullptr); // Set DexPathList. ArtField* path_list_field = soa.DecodeField(WellKnownClasses::dalvik_system_PathClassLoader_pathList); DCHECK(path_list_field != nullptr); path_list_field->SetObject(h_path_class_loader.Get(), h_dex_path_list.Get()); // Make a pretend boot-classpath. // TODO: Should we scan the image? ArtField* const parent_field = mirror::Class::FindField(self, hs.NewHandle(h_path_class_loader->GetClass()), "parent", "Ljava/lang/ClassLoader;"); DCHECK(parent_field!= nullptr); mirror::Object* boot_cl = soa.Decode(WellKnownClasses::java_lang_BootClassLoader)->AllocObject(self); parent_field->SetObject(h_path_class_loader.Get(), boot_cl); // Make it a global ref and return. ScopedLocalRef local_ref( soa.Env(), soa.Env()->AddLocalReference(h_path_class_loader.Get())); return soa.Env()->NewGlobalRef(local_ref.get()); } ArtMethod* ClassLinker::CreateRuntimeMethod() { ArtMethod* method = AllocArtMethodArray(Thread::Current(), 1); CHECK(method != nullptr); method->SetDexMethodIndex(DexFile::kDexNoIndex); CHECK(method->IsRuntimeMethod()); return method; } void ClassLinker::DropFindArrayClassCache() { std::fill_n(find_array_class_cache_, kFindArrayCacheSize, GcRoot(nullptr)); find_array_class_cache_next_victim_ = 0; } } // namespace art