| /* |
| * Copyright (C) 2012 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 "art_method-inl.h" |
| #include "base/callee_save_type.h" |
| #include "callee_save_frame.h" |
| #include "class_linker-inl.h" |
| #include "class_table-inl.h" |
| #include "dex/dex_file-inl.h" |
| #include "dex/dex_file_types.h" |
| #include "entrypoints/entrypoint_utils-inl.h" |
| #include "gc/heap.h" |
| #include "mirror/class-inl.h" |
| #include "mirror/class_loader.h" |
| #include "mirror/object-inl.h" |
| #include "mirror/object_array-inl.h" |
| #include "oat_file.h" |
| #include "runtime.h" |
| |
| namespace art { |
| |
| static void StoreObjectInBss(ArtMethod* outer_method, |
| const OatFile* oat_file, |
| size_t bss_offset, |
| ObjPtr<mirror::Object> object) REQUIRES_SHARED(Locks::mutator_lock_) { |
| // Used for storing Class or String in .bss GC roots. |
| static_assert(sizeof(GcRoot<mirror::Class>) == sizeof(GcRoot<mirror::Object>), "Size check."); |
| static_assert(sizeof(GcRoot<mirror::String>) == sizeof(GcRoot<mirror::Object>), "Size check."); |
| DCHECK_NE(bss_offset, IndexBssMappingLookup::npos); |
| DCHECK_ALIGNED(bss_offset, sizeof(GcRoot<mirror::Object>)); |
| if (UNLIKELY(!oat_file->IsExecutable())) { |
| // There are situations where we execute bytecode tied to an oat file opened |
| // as non-executable (i.e. the AOT-compiled code cannot be executed) and we |
| // can JIT that bytecode and get here without the .bss being mmapped. |
| return; |
| } |
| GcRoot<mirror::Object>* slot = reinterpret_cast<GcRoot<mirror::Object>*>( |
| const_cast<uint8_t*>(oat_file->BssBegin() + bss_offset)); |
| DCHECK_GE(slot, oat_file->GetBssGcRoots().data()); |
| DCHECK_LT(slot, oat_file->GetBssGcRoots().data() + oat_file->GetBssGcRoots().size()); |
| if (slot->IsNull()) { |
| // This may race with another thread trying to store the very same value but that's OK. |
| std::atomic<GcRoot<mirror::Object>>* atomic_slot = |
| reinterpret_cast<std::atomic<GcRoot<mirror::Object>>*>(slot); |
| static_assert(sizeof(*slot) == sizeof(*atomic_slot), "Size check"); |
| atomic_slot->store(GcRoot<mirror::Object>(object), std::memory_order_release); |
| // We need a write barrier for the class loader that holds the GC roots in the .bss. |
| ObjPtr<mirror::ClassLoader> class_loader = outer_method->GetClassLoader(); |
| Runtime* runtime = Runtime::Current(); |
| if (kIsDebugBuild) { |
| ClassTable* class_table = runtime->GetClassLinker()->ClassTableForClassLoader(class_loader); |
| CHECK(class_table != nullptr && !class_table->InsertOatFile(oat_file)) |
| << "Oat file with .bss GC roots was not registered in class table: " |
| << oat_file->GetLocation(); |
| } |
| if (class_loader != nullptr) { |
| WriteBarrier::ForEveryFieldWrite(class_loader); |
| } else { |
| runtime->GetClassLinker()->WriteBarrierForBootOatFileBssRoots(oat_file); |
| } |
| } else { |
| // Each slot serves to store exactly one Class or String. |
| DCHECK_EQ(object, slot->Read()); |
| } |
| } |
| |
| static inline void StoreTypeInBss(ArtMethod* outer_method, |
| dex::TypeIndex type_idx, |
| ObjPtr<mirror::Class> resolved_type) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| const DexFile* dex_file = outer_method->GetDexFile(); |
| DCHECK(dex_file != nullptr); |
| const OatDexFile* oat_dex_file = dex_file->GetOatDexFile(); |
| if (oat_dex_file != nullptr) { |
| size_t bss_offset = IndexBssMappingLookup::GetBssOffset(oat_dex_file->GetTypeBssMapping(), |
| type_idx.index_, |
| dex_file->NumTypeIds(), |
| sizeof(GcRoot<mirror::Class>)); |
| if (bss_offset != IndexBssMappingLookup::npos) { |
| StoreObjectInBss(outer_method, oat_dex_file->GetOatFile(), bss_offset, resolved_type); |
| } |
| } |
| } |
| |
| static inline void StoreStringInBss(ArtMethod* outer_method, |
| dex::StringIndex string_idx, |
| ObjPtr<mirror::String> resolved_string) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| const DexFile* dex_file = outer_method->GetDexFile(); |
| DCHECK(dex_file != nullptr); |
| const OatDexFile* oat_dex_file = dex_file->GetOatDexFile(); |
| if (oat_dex_file != nullptr) { |
| size_t bss_offset = IndexBssMappingLookup::GetBssOffset(oat_dex_file->GetStringBssMapping(), |
| string_idx.index_, |
| dex_file->NumStringIds(), |
| sizeof(GcRoot<mirror::Class>)); |
| if (bss_offset != IndexBssMappingLookup::npos) { |
| StoreObjectInBss(outer_method, oat_dex_file->GetOatFile(), bss_offset, resolved_string); |
| } |
| } |
| } |
| |
| static ALWAYS_INLINE bool CanReferenceBss(ArtMethod* outer_method, ArtMethod* caller) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| // .bss references are used only for AOT-compiled code and only when the instruction |
| // originates from the outer method's dex file and the type or string index is tied to |
| // that dex file. As we do not want to check if the call is coming from AOT-compiled |
| // code (that could be expensive), simply check if the caller has the same dex file. |
| // |
| // If we've accepted running AOT-compiled code despite the runtime class loader |
| // resolving the caller to a different dex file, this check shall prevent us from |
| // filling the .bss slot and we shall keep going through the slow path. This is slow |
| // but correct; we do not really care that much about performance in this odd case. |
| // |
| // JIT can inline throwing instructions across dex files and this check prevents |
| // looking up the index in the wrong dex file in that case. If the caller and outer |
| // method have the same dex file, we may or may not find a .bss slot to update; |
| // if we do, this can still benefit AOT-compiled code executed later. |
| return outer_method->GetDexFile() == caller->GetDexFile(); |
| } |
| |
| extern "C" mirror::Class* artInitializeStaticStorageFromCode(mirror::Class* klass, Thread* self) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| // Called to ensure static storage base is initialized for direct static field reads and writes. |
| // A class may be accessing another class' fields when it doesn't have access, as access has been |
| // given by inheritance. |
| ScopedQuickEntrypointChecks sqec(self); |
| DCHECK(klass != nullptr); |
| ClassLinker* class_linker = Runtime::Current()->GetClassLinker(); |
| StackHandleScope<1> hs(self); |
| Handle<mirror::Class> h_klass = hs.NewHandle(klass); |
| bool success = class_linker->EnsureInitialized( |
| self, h_klass, /* can_init_fields= */ true, /* can_init_parents= */ true); |
| if (UNLIKELY(!success)) { |
| return nullptr; |
| } |
| return h_klass.Get(); |
| } |
| |
| extern "C" mirror::Class* artResolveTypeFromCode(uint32_t type_idx, Thread* self) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| // Called when the .bss slot was empty or for main-path runtime call. |
| ScopedQuickEntrypointChecks sqec(self); |
| auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod( |
| self, CalleeSaveType::kSaveEverythingForClinit); |
| ArtMethod* caller = caller_and_outer.caller; |
| ObjPtr<mirror::Class> result = ResolveVerifyAndClinit(dex::TypeIndex(type_idx), |
| caller, |
| self, |
| /* can_run_clinit= */ false, |
| /* verify_access= */ false); |
| if (LIKELY(result != nullptr) && CanReferenceBss(caller_and_outer.outer_method, caller)) { |
| StoreTypeInBss(caller_and_outer.outer_method, dex::TypeIndex(type_idx), result); |
| } |
| return result.Ptr(); |
| } |
| |
| extern "C" mirror::Class* artResolveTypeAndVerifyAccessFromCode(uint32_t type_idx, Thread* self) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| // Called when caller isn't guaranteed to have access to a type. |
| ScopedQuickEntrypointChecks sqec(self); |
| auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self, |
| CalleeSaveType::kSaveEverything); |
| ArtMethod* caller = caller_and_outer.caller; |
| ObjPtr<mirror::Class> result = ResolveVerifyAndClinit(dex::TypeIndex(type_idx), |
| caller, |
| self, |
| /* can_run_clinit= */ false, |
| /* verify_access= */ true); |
| // Do not StoreTypeInBss(); access check entrypoint is never used together with .bss. |
| return result.Ptr(); |
| } |
| |
| extern "C" mirror::MethodHandle* artResolveMethodHandleFromCode(uint32_t method_handle_idx, |
| Thread* self) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| ScopedQuickEntrypointChecks sqec(self); |
| auto caller_and_outer = |
| GetCalleeSaveMethodCallerAndOuterMethod(self, CalleeSaveType::kSaveEverything); |
| ArtMethod* caller = caller_and_outer.caller; |
| ObjPtr<mirror::MethodHandle> result = ResolveMethodHandleFromCode(caller, method_handle_idx); |
| return result.Ptr(); |
| } |
| |
| extern "C" mirror::MethodType* artResolveMethodTypeFromCode(uint32_t proto_idx, Thread* self) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| ScopedQuickEntrypointChecks sqec(self); |
| auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self, |
| CalleeSaveType::kSaveEverything); |
| ArtMethod* caller = caller_and_outer.caller; |
| ObjPtr<mirror::MethodType> result = ResolveMethodTypeFromCode(caller, dex::ProtoIndex(proto_idx)); |
| return result.Ptr(); |
| } |
| |
| extern "C" mirror::String* artResolveStringFromCode(int32_t string_idx, Thread* self) |
| REQUIRES_SHARED(Locks::mutator_lock_) { |
| ScopedQuickEntrypointChecks sqec(self); |
| auto caller_and_outer = GetCalleeSaveMethodCallerAndOuterMethod(self, |
| CalleeSaveType::kSaveEverything); |
| ArtMethod* caller = caller_and_outer.caller; |
| ObjPtr<mirror::String> result = |
| Runtime::Current()->GetClassLinker()->ResolveString(dex::StringIndex(string_idx), caller); |
| if (LIKELY(result != nullptr) && CanReferenceBss(caller_and_outer.outer_method, caller)) { |
| StoreStringInBss(caller_and_outer.outer_method, dex::StringIndex(string_idx), result); |
| } |
| return result.Ptr(); |
| } |
| |
| } // namespace art |