| /* Copyright (C) 2016 The Android Open Source Project |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This file implements interfaces from the file jvmti.h. This implementation |
| * is licensed under the same terms as the file jvmti.h. The |
| * copyright and license information for the file jvmti.h follows. |
| * |
| * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| #include "ti_redefine.h" |
| |
| #include <limits> |
| |
| #include "android-base/stringprintf.h" |
| |
| #include "art_jvmti.h" |
| #include "base/array_slice.h" |
| #include "base/logging.h" |
| #include "dex_file.h" |
| #include "dex_file_types.h" |
| #include "events-inl.h" |
| #include "gc/allocation_listener.h" |
| #include "gc/heap.h" |
| #include "instrumentation.h" |
| #include "jit/jit.h" |
| #include "jit/jit_code_cache.h" |
| #include "jni_env_ext-inl.h" |
| #include "jvmti_allocator.h" |
| #include "mirror/class-inl.h" |
| #include "mirror/class_ext.h" |
| #include "mirror/object.h" |
| #include "object_lock.h" |
| #include "runtime.h" |
| #include "ScopedLocalRef.h" |
| #include "ti_class_loader.h" |
| #include "transform.h" |
| #include "verifier/method_verifier.h" |
| #include "verifier/verifier_log_mode.h" |
| |
| namespace openjdkjvmti { |
| |
| using android::base::StringPrintf; |
| |
| // This visitor walks thread stacks and allocates and sets up the obsolete methods. It also does |
| // some basic sanity checks that the obsolete method is sane. |
| class ObsoleteMethodStackVisitor : public art::StackVisitor { |
| protected: |
| ObsoleteMethodStackVisitor( |
| art::Thread* thread, |
| art::LinearAlloc* allocator, |
| const std::unordered_set<art::ArtMethod*>& obsoleted_methods, |
| /*out*/std::unordered_map<art::ArtMethod*, art::ArtMethod*>* obsolete_maps) |
| : StackVisitor(thread, |
| /*context*/nullptr, |
| StackVisitor::StackWalkKind::kIncludeInlinedFrames), |
| allocator_(allocator), |
| obsoleted_methods_(obsoleted_methods), |
| obsolete_maps_(obsolete_maps) { } |
| |
| ~ObsoleteMethodStackVisitor() OVERRIDE {} |
| |
| public: |
| // Returns true if we successfully installed obsolete methods on this thread, filling |
| // obsolete_maps_ with the translations if needed. Returns false and fills error_msg if we fail. |
| // The stack is cleaned up when we fail. |
| static void UpdateObsoleteFrames( |
| art::Thread* thread, |
| art::LinearAlloc* allocator, |
| const std::unordered_set<art::ArtMethod*>& obsoleted_methods, |
| /*out*/std::unordered_map<art::ArtMethod*, art::ArtMethod*>* obsolete_maps) |
| REQUIRES(art::Locks::mutator_lock_) { |
| ObsoleteMethodStackVisitor visitor(thread, |
| allocator, |
| obsoleted_methods, |
| obsolete_maps); |
| visitor.WalkStack(); |
| } |
| |
| bool VisitFrame() OVERRIDE REQUIRES(art::Locks::mutator_lock_) { |
| art::ArtMethod* old_method = GetMethod(); |
| if (obsoleted_methods_.find(old_method) != obsoleted_methods_.end()) { |
| // We cannot ensure that the right dex file is used in inlined frames so we don't support |
| // redefining them. |
| DCHECK(!IsInInlinedFrame()) << "Inlined frames are not supported when using redefinition"; |
| // TODO We should really support intrinsic obsolete methods. |
| // TODO We should really support redefining intrinsics. |
| // We don't support intrinsics so check for them here. |
| DCHECK(!old_method->IsIntrinsic()); |
| art::ArtMethod* new_obsolete_method = nullptr; |
| auto obsolete_method_pair = obsolete_maps_->find(old_method); |
| if (obsolete_method_pair == obsolete_maps_->end()) { |
| // Create a new Obsolete Method and put it in the list. |
| art::Runtime* runtime = art::Runtime::Current(); |
| art::ClassLinker* cl = runtime->GetClassLinker(); |
| auto ptr_size = cl->GetImagePointerSize(); |
| const size_t method_size = art::ArtMethod::Size(ptr_size); |
| auto* method_storage = allocator_->Alloc(GetThread(), method_size); |
| CHECK(method_storage != nullptr) << "Unable to allocate storage for obsolete version of '" |
| << old_method->PrettyMethod() << "'"; |
| new_obsolete_method = new (method_storage) art::ArtMethod(); |
| new_obsolete_method->CopyFrom(old_method, ptr_size); |
| DCHECK_EQ(new_obsolete_method->GetDeclaringClass(), old_method->GetDeclaringClass()); |
| new_obsolete_method->SetIsObsolete(); |
| new_obsolete_method->SetDontCompile(); |
| obsolete_maps_->insert({old_method, new_obsolete_method}); |
| // Update JIT Data structures to point to the new method. |
| art::jit::Jit* jit = art::Runtime::Current()->GetJit(); |
| if (jit != nullptr) { |
| // Notify the JIT we are making this obsolete method. It will update the jit's internal |
| // structures to keep track of the new obsolete method. |
| jit->GetCodeCache()->MoveObsoleteMethod(old_method, new_obsolete_method); |
| } |
| } else { |
| new_obsolete_method = obsolete_method_pair->second; |
| } |
| DCHECK(new_obsolete_method != nullptr); |
| SetMethod(new_obsolete_method); |
| } |
| return true; |
| } |
| |
| private: |
| // The linear allocator we should use to make new methods. |
| art::LinearAlloc* allocator_; |
| // The set of all methods which could be obsoleted. |
| const std::unordered_set<art::ArtMethod*>& obsoleted_methods_; |
| // A map from the original to the newly allocated obsolete method for frames on this thread. The |
| // values in this map must be added to the obsolete_methods_ (and obsolete_dex_caches_) fields of |
| // the redefined classes ClassExt by the caller. |
| std::unordered_map<art::ArtMethod*, art::ArtMethod*>* obsolete_maps_; |
| }; |
| |
| jvmtiError Redefiner::IsModifiableClass(jvmtiEnv* env ATTRIBUTE_UNUSED, |
| jclass klass, |
| jboolean* is_redefinable) { |
| // TODO Check for the appropriate feature flags once we have enabled them. |
| art::Thread* self = art::Thread::Current(); |
| art::ScopedObjectAccess soa(self); |
| art::StackHandleScope<1> hs(self); |
| art::ObjPtr<art::mirror::Object> obj(self->DecodeJObject(klass)); |
| if (obj.IsNull()) { |
| return ERR(INVALID_CLASS); |
| } |
| art::Handle<art::mirror::Class> h_klass(hs.NewHandle(obj->AsClass())); |
| std::string err_unused; |
| *is_redefinable = |
| Redefiner::GetClassRedefinitionError(h_klass, &err_unused) == OK ? JNI_TRUE : JNI_FALSE; |
| return OK; |
| } |
| |
| jvmtiError Redefiner::GetClassRedefinitionError(art::Handle<art::mirror::Class> klass, |
| /*out*/std::string* error_msg) { |
| if (klass->IsPrimitive()) { |
| *error_msg = "Modification of primitive classes is not supported"; |
| return ERR(UNMODIFIABLE_CLASS); |
| } else if (klass->IsInterface()) { |
| *error_msg = "Modification of Interface classes is currently not supported"; |
| return ERR(UNMODIFIABLE_CLASS); |
| } else if (klass->IsArrayClass()) { |
| *error_msg = "Modification of Array classes is not supported"; |
| return ERR(UNMODIFIABLE_CLASS); |
| } else if (klass->IsProxyClass()) { |
| *error_msg = "Modification of proxy classes is not supported"; |
| return ERR(UNMODIFIABLE_CLASS); |
| } |
| |
| // TODO We should check if the class has non-obsoletable methods on the stack |
| LOG(WARNING) << "presence of non-obsoletable methods on stacks is not currently checked"; |
| return OK; |
| } |
| |
| // Moves dex data to an anonymous, read-only mmap'd region. |
| std::unique_ptr<art::MemMap> Redefiner::MoveDataToMemMap(const std::string& original_location, |
| jint data_len, |
| const unsigned char* dex_data, |
| std::string* error_msg) { |
| std::unique_ptr<art::MemMap> map(art::MemMap::MapAnonymous( |
| StringPrintf("%s-transformed", original_location.c_str()).c_str(), |
| nullptr, |
| data_len, |
| PROT_READ|PROT_WRITE, |
| /*low_4gb*/false, |
| /*reuse*/false, |
| error_msg)); |
| if (map == nullptr) { |
| return map; |
| } |
| memcpy(map->Begin(), dex_data, data_len); |
| // Make the dex files mmap read only. This matches how other DexFiles are mmaped and prevents |
| // programs from corrupting it. |
| map->Protect(PROT_READ); |
| return map; |
| } |
| |
| Redefiner::ClassRedefinition::ClassRedefinition( |
| Redefiner* driver, |
| jclass klass, |
| const art::DexFile* redefined_dex_file, |
| const char* class_sig, |
| art::ArraySlice<const unsigned char> orig_dex_file) : |
| driver_(driver), |
| klass_(klass), |
| dex_file_(redefined_dex_file), |
| class_sig_(class_sig), |
| original_dex_file_(orig_dex_file) { |
| GetMirrorClass()->MonitorEnter(driver_->self_); |
| } |
| |
| Redefiner::ClassRedefinition::~ClassRedefinition() { |
| if (driver_ != nullptr) { |
| GetMirrorClass()->MonitorExit(driver_->self_); |
| } |
| } |
| |
| jvmtiError Redefiner::RedefineClasses(ArtJvmTiEnv* env, |
| art::Runtime* runtime, |
| art::Thread* self, |
| jint class_count, |
| const jvmtiClassDefinition* definitions, |
| /*out*/std::string* error_msg) { |
| if (env == nullptr) { |
| *error_msg = "env was null!"; |
| return ERR(INVALID_ENVIRONMENT); |
| } else if (class_count < 0) { |
| *error_msg = "class_count was less then 0"; |
| return ERR(ILLEGAL_ARGUMENT); |
| } else if (class_count == 0) { |
| // We don't actually need to do anything. Just return OK. |
| return OK; |
| } else if (definitions == nullptr) { |
| *error_msg = "null definitions!"; |
| return ERR(NULL_POINTER); |
| } |
| std::vector<ArtClassDefinition> def_vector; |
| def_vector.reserve(class_count); |
| for (jint i = 0; i < class_count; i++) { |
| // We make a copy of the class_bytes to pass into the retransformation. |
| // This makes cleanup easier (since we unambiguously own the bytes) and also is useful since we |
| // will need to keep the original bytes around unaltered for subsequent RetransformClasses calls |
| // to get the passed in bytes. |
| // TODO Implement saving the original bytes. |
| unsigned char* class_bytes_copy = nullptr; |
| jvmtiError res = env->Allocate(definitions[i].class_byte_count, &class_bytes_copy); |
| if (res != OK) { |
| return res; |
| } |
| memcpy(class_bytes_copy, definitions[i].class_bytes, definitions[i].class_byte_count); |
| |
| ArtClassDefinition def; |
| def.dex_len = definitions[i].class_byte_count; |
| def.dex_data = MakeJvmtiUniquePtr(env, class_bytes_copy); |
| // We are definitely modified. |
| def.SetModified(); |
| def.original_dex_file = art::ArraySlice<const unsigned char>(definitions[i].class_bytes, |
| definitions[i].class_byte_count); |
| res = Transformer::FillInTransformationData(env, definitions[i].klass, &def); |
| if (res != OK) { |
| return res; |
| } |
| def_vector.push_back(std::move(def)); |
| } |
| // Call all the transformation events. |
| jvmtiError res = Transformer::RetransformClassesDirect(env, |
| self, |
| &def_vector); |
| if (res != OK) { |
| // Something went wrong with transformation! |
| return res; |
| } |
| return RedefineClassesDirect(env, runtime, self, def_vector, error_msg); |
| } |
| |
| jvmtiError Redefiner::RedefineClassesDirect(ArtJvmTiEnv* env, |
| art::Runtime* runtime, |
| art::Thread* self, |
| const std::vector<ArtClassDefinition>& definitions, |
| std::string* error_msg) { |
| DCHECK(env != nullptr); |
| if (definitions.size() == 0) { |
| // We don't actually need to do anything. Just return OK. |
| return OK; |
| } |
| // Stop JIT for the duration of this redefine since the JIT might concurrently compile a method we |
| // are going to redefine. |
| art::jit::ScopedJitSuspend suspend_jit; |
| // Get shared mutator lock so we can lock all the classes. |
| art::ScopedObjectAccess soa(self); |
| Redefiner r(runtime, self, error_msg); |
| for (const ArtClassDefinition& def : definitions) { |
| // Only try to transform classes that have been modified. |
| if (def.IsModified(self)) { |
| jvmtiError res = r.AddRedefinition(env, def); |
| if (res != OK) { |
| return res; |
| } |
| } |
| } |
| return r.Run(); |
| } |
| |
| jvmtiError Redefiner::AddRedefinition(ArtJvmTiEnv* env, const ArtClassDefinition& def) { |
| std::string original_dex_location; |
| jvmtiError ret = OK; |
| if ((ret = GetClassLocation(env, def.klass, &original_dex_location))) { |
| *error_msg_ = "Unable to get original dex file location!"; |
| return ret; |
| } |
| char* generic_ptr_unused = nullptr; |
| char* signature_ptr = nullptr; |
| if ((ret = env->GetClassSignature(def.klass, &signature_ptr, &generic_ptr_unused)) != OK) { |
| *error_msg_ = "Unable to get class signature!"; |
| return ret; |
| } |
| JvmtiUniquePtr generic_unique_ptr(MakeJvmtiUniquePtr(env, generic_ptr_unused)); |
| JvmtiUniquePtr signature_unique_ptr(MakeJvmtiUniquePtr(env, signature_ptr)); |
| std::unique_ptr<art::MemMap> map(MoveDataToMemMap(original_dex_location, |
| def.dex_len, |
| def.dex_data.get(), |
| error_msg_)); |
| std::ostringstream os; |
| if (map.get() == nullptr) { |
| os << "Failed to create anonymous mmap for modified dex file of class " << def.name |
| << "in dex file " << original_dex_location << " because: " << *error_msg_; |
| *error_msg_ = os.str(); |
| return ERR(OUT_OF_MEMORY); |
| } |
| if (map->Size() < sizeof(art::DexFile::Header)) { |
| *error_msg_ = "Could not read dex file header because dex_data was too short"; |
| return ERR(INVALID_CLASS_FORMAT); |
| } |
| uint32_t checksum = reinterpret_cast<const art::DexFile::Header*>(map->Begin())->checksum_; |
| std::unique_ptr<const art::DexFile> dex_file(art::DexFile::Open(map->GetName(), |
| checksum, |
| std::move(map), |
| /*verify*/true, |
| /*verify_checksum*/true, |
| error_msg_)); |
| if (dex_file.get() == nullptr) { |
| os << "Unable to load modified dex file for " << def.name << ": " << *error_msg_; |
| *error_msg_ = os.str(); |
| return ERR(INVALID_CLASS_FORMAT); |
| } |
| redefinitions_.push_back( |
| Redefiner::ClassRedefinition(this, |
| def.klass, |
| dex_file.release(), |
| signature_ptr, |
| def.original_dex_file)); |
| return OK; |
| } |
| |
| art::mirror::Class* Redefiner::ClassRedefinition::GetMirrorClass() { |
| return driver_->self_->DecodeJObject(klass_)->AsClass(); |
| } |
| |
| art::mirror::ClassLoader* Redefiner::ClassRedefinition::GetClassLoader() { |
| return GetMirrorClass()->GetClassLoader(); |
| } |
| |
| art::mirror::DexCache* Redefiner::ClassRedefinition::CreateNewDexCache( |
| art::Handle<art::mirror::ClassLoader> loader) { |
| return driver_->runtime_->GetClassLinker()->RegisterDexFile(*dex_file_, loader.Get()).Ptr(); |
| } |
| |
| void Redefiner::RecordFailure(jvmtiError result, |
| const std::string& class_sig, |
| const std::string& error_msg) { |
| *error_msg_ = StringPrintf("Unable to perform redefinition of '%s': %s", |
| class_sig.c_str(), |
| error_msg.c_str()); |
| result_ = result; |
| } |
| |
| art::mirror::ByteArray* Redefiner::ClassRedefinition::AllocateOrGetOriginalDexFileBytes() { |
| // If we have been specifically given a new set of bytes use that |
| if (original_dex_file_.size() != 0) { |
| return art::mirror::ByteArray::AllocateAndFill( |
| driver_->self_, |
| reinterpret_cast<const signed char*>(&original_dex_file_.At(0)), |
| original_dex_file_.size()); |
| } |
| |
| // See if we already have one set. |
| art::ObjPtr<art::mirror::ClassExt> ext(GetMirrorClass()->GetExtData()); |
| if (!ext.IsNull()) { |
| art::ObjPtr<art::mirror::ByteArray> old_original_bytes(ext->GetOriginalDexFileBytes()); |
| if (!old_original_bytes.IsNull()) { |
| // We do. Use it. |
| return old_original_bytes.Ptr(); |
| } |
| } |
| |
| // Copy the current dex_file |
| const art::DexFile& current_dex_file = GetMirrorClass()->GetDexFile(); |
| // TODO Handle this or make it so it cannot happen. |
| if (current_dex_file.NumClassDefs() != 1) { |
| LOG(WARNING) << "Current dex file has more than one class in it. Calling RetransformClasses " |
| << "on this class might fail if no transformations are applied to it!"; |
| } |
| return art::mirror::ByteArray::AllocateAndFill( |
| driver_->self_, |
| reinterpret_cast<const signed char*>(current_dex_file.Begin()), |
| current_dex_file.Size()); |
| } |
| |
| struct CallbackCtx { |
| art::LinearAlloc* allocator; |
| std::unordered_map<art::ArtMethod*, art::ArtMethod*> obsolete_map; |
| std::unordered_set<art::ArtMethod*> obsolete_methods; |
| |
| explicit CallbackCtx(art::LinearAlloc* alloc) : allocator(alloc) {} |
| }; |
| |
| void DoAllocateObsoleteMethodsCallback(art::Thread* t, void* vdata) NO_THREAD_SAFETY_ANALYSIS { |
| CallbackCtx* data = reinterpret_cast<CallbackCtx*>(vdata); |
| ObsoleteMethodStackVisitor::UpdateObsoleteFrames(t, |
| data->allocator, |
| data->obsolete_methods, |
| &data->obsolete_map); |
| } |
| |
| // This creates any ArtMethod* structures needed for obsolete methods and ensures that the stack is |
| // updated so they will be run. |
| // TODO Rewrite so we can do this only once regardless of how many redefinitions there are. |
| void Redefiner::ClassRedefinition::FindAndAllocateObsoleteMethods(art::mirror::Class* art_klass) { |
| art::ScopedAssertNoThreadSuspension ns("No thread suspension during thread stack walking"); |
| art::mirror::ClassExt* ext = art_klass->GetExtData(); |
| CHECK(ext->GetObsoleteMethods() != nullptr); |
| art::ClassLinker* linker = driver_->runtime_->GetClassLinker(); |
| CallbackCtx ctx(linker->GetAllocatorForClassLoader(art_klass->GetClassLoader())); |
| // Add all the declared methods to the map |
| for (auto& m : art_klass->GetDeclaredMethods(art::kRuntimePointerSize)) { |
| // TODO It should be possible to simply filter out some methods where they cannot really become |
| // obsolete, such as native methods and keep their original (possibly optimized) |
| // implementations. We don't do this, however, since we would need to mark these functions |
| // (still in the classes declared_methods array) as obsolete so we will find the correct dex |
| // file to get meta-data from (for example about stack-frame size). |
| ctx.obsolete_methods.insert(&m); |
| // TODO Allow this or check in IsModifiableClass. |
| DCHECK(!m.IsIntrinsic()); |
| } |
| { |
| art::MutexLock mu(driver_->self_, *art::Locks::thread_list_lock_); |
| art::ThreadList* list = art::Runtime::Current()->GetThreadList(); |
| list->ForEach(DoAllocateObsoleteMethodsCallback, static_cast<void*>(&ctx)); |
| } |
| FillObsoleteMethodMap(art_klass, ctx.obsolete_map); |
| } |
| |
| // Fills the obsolete method map in the art_klass's extData. This is so obsolete methods are able to |
| // figure out their DexCaches. |
| void Redefiner::ClassRedefinition::FillObsoleteMethodMap( |
| art::mirror::Class* art_klass, |
| const std::unordered_map<art::ArtMethod*, art::ArtMethod*>& obsoletes) { |
| int32_t index = 0; |
| art::mirror::ClassExt* ext_data = art_klass->GetExtData(); |
| art::mirror::PointerArray* obsolete_methods = ext_data->GetObsoleteMethods(); |
| art::mirror::ObjectArray<art::mirror::DexCache>* obsolete_dex_caches = |
| ext_data->GetObsoleteDexCaches(); |
| int32_t num_method_slots = obsolete_methods->GetLength(); |
| // Find the first empty index. |
| for (; index < num_method_slots; index++) { |
| if (obsolete_methods->GetElementPtrSize<art::ArtMethod*>( |
| index, art::kRuntimePointerSize) == nullptr) { |
| break; |
| } |
| } |
| // Make sure we have enough space. |
| CHECK_GT(num_method_slots, static_cast<int32_t>(obsoletes.size() + index)); |
| CHECK(obsolete_dex_caches->Get(index) == nullptr); |
| // Fill in the map. |
| for (auto& obs : obsoletes) { |
| obsolete_methods->SetElementPtrSize(index, obs.second, art::kRuntimePointerSize); |
| obsolete_dex_caches->Set(index, art_klass->GetDexCache()); |
| index++; |
| } |
| } |
| |
| // Try and get the declared method. First try to get a virtual method then a direct method if that's |
| // not found. |
| static art::ArtMethod* FindMethod(art::Handle<art::mirror::Class> klass, |
| const char* name, |
| art::Signature sig) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| art::ArtMethod* m = klass->FindDeclaredVirtualMethod(name, sig, art::kRuntimePointerSize); |
| if (m == nullptr) { |
| m = klass->FindDeclaredDirectMethod(name, sig, art::kRuntimePointerSize); |
| } |
| return m; |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckSameMethods() { |
| art::StackHandleScope<1> hs(driver_->self_); |
| art::Handle<art::mirror::Class> h_klass(hs.NewHandle(GetMirrorClass())); |
| DCHECK_EQ(dex_file_->NumClassDefs(), 1u); |
| |
| art::ClassDataItemIterator new_iter(*dex_file_, |
| dex_file_->GetClassData(dex_file_->GetClassDef(0))); |
| |
| // Make sure we have the same number of methods. |
| uint32_t num_new_method = new_iter.NumVirtualMethods() + new_iter.NumDirectMethods(); |
| uint32_t num_old_method = h_klass->GetDeclaredMethodsSlice(art::kRuntimePointerSize).size(); |
| if (num_new_method != num_old_method) { |
| bool bigger = num_new_method > num_old_method; |
| RecordFailure(bigger ? ERR(UNSUPPORTED_REDEFINITION_METHOD_ADDED) |
| : ERR(UNSUPPORTED_REDEFINITION_METHOD_DELETED), |
| StringPrintf("Total number of declared methods changed from %d to %d", |
| num_old_method, num_new_method)); |
| return false; |
| } |
| |
| // Skip all of the fields. We should have already checked this. |
| while (new_iter.HasNextStaticField() || new_iter.HasNextInstanceField()) { |
| new_iter.Next(); |
| } |
| // Check each of the methods. NB we don't need to specifically check for removals since the 2 dex |
| // files have the same number of methods, which means there must be an equal amount of additions |
| // and removals. |
| for (; new_iter.HasNextVirtualMethod() || new_iter.HasNextDirectMethod(); new_iter.Next()) { |
| // Get the data on the method we are searching for |
| const art::DexFile::MethodId& new_method_id = dex_file_->GetMethodId(new_iter.GetMemberIndex()); |
| const char* new_method_name = dex_file_->GetMethodName(new_method_id); |
| art::Signature new_method_signature = dex_file_->GetMethodSignature(new_method_id); |
| art::ArtMethod* old_method = FindMethod(h_klass, new_method_name, new_method_signature); |
| // If we got past the check for the same number of methods above that means there must be at |
| // least one added and one removed method. We will return the ADDED failure message since it is |
| // easier to get a useful error report for it. |
| if (old_method == nullptr) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_METHOD_ADDED), |
| StringPrintf("Unknown method '%s' (sig: %s) was added!", |
| new_method_name, |
| new_method_signature.ToString().c_str())); |
| return false; |
| } |
| // Since direct methods have different flags than virtual ones (specifically direct methods must |
| // have kAccPrivate or kAccStatic or kAccConstructor flags) we can tell if a method changes from |
| // virtual to direct. |
| uint32_t new_flags = new_iter.GetMethodAccessFlags(); |
| if (new_flags != (old_method->GetAccessFlags() & art::kAccValidMethodFlags)) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED), |
| StringPrintf("method '%s' (sig: %s) had different access flags", |
| new_method_name, |
| new_method_signature.ToString().c_str())); |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckSameFields() { |
| art::StackHandleScope<1> hs(driver_->self_); |
| art::Handle<art::mirror::Class> h_klass(hs.NewHandle(GetMirrorClass())); |
| DCHECK_EQ(dex_file_->NumClassDefs(), 1u); |
| art::ClassDataItemIterator new_iter(*dex_file_, |
| dex_file_->GetClassData(dex_file_->GetClassDef(0))); |
| const art::DexFile& old_dex_file = h_klass->GetDexFile(); |
| art::ClassDataItemIterator old_iter(old_dex_file, |
| old_dex_file.GetClassData(*h_klass->GetClassDef())); |
| // Instance and static fields can be differentiated by their flags so no need to check them |
| // separately. |
| while (new_iter.HasNextInstanceField() || new_iter.HasNextStaticField()) { |
| // Get the data on the method we are searching for |
| const art::DexFile::FieldId& new_field_id = dex_file_->GetFieldId(new_iter.GetMemberIndex()); |
| const char* new_field_name = dex_file_->GetFieldName(new_field_id); |
| const char* new_field_type = dex_file_->GetFieldTypeDescriptor(new_field_id); |
| |
| if (!(old_iter.HasNextInstanceField() || old_iter.HasNextStaticField())) { |
| // We are missing the old version of this method! |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED), |
| StringPrintf("Unknown field '%s' (type: %s) added!", |
| new_field_name, |
| new_field_type)); |
| return false; |
| } |
| |
| const art::DexFile::FieldId& old_field_id = old_dex_file.GetFieldId(old_iter.GetMemberIndex()); |
| const char* old_field_name = old_dex_file.GetFieldName(old_field_id); |
| const char* old_field_type = old_dex_file.GetFieldTypeDescriptor(old_field_id); |
| |
| // Check name and type. |
| if (strcmp(old_field_name, new_field_name) != 0 || |
| strcmp(old_field_type, new_field_type) != 0) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED), |
| StringPrintf("Field changed from '%s' (sig: %s) to '%s' (sig: %s)!", |
| old_field_name, |
| old_field_type, |
| new_field_name, |
| new_field_type)); |
| return false; |
| } |
| |
| // Since static fields have different flags than instance ones (specifically static fields must |
| // have the kAccStatic flag) we can tell if a field changes from static to instance. |
| if (new_iter.GetFieldAccessFlags() != old_iter.GetFieldAccessFlags()) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED), |
| StringPrintf("Field '%s' (sig: %s) had different access flags", |
| new_field_name, |
| new_field_type)); |
| return false; |
| } |
| |
| new_iter.Next(); |
| old_iter.Next(); |
| } |
| if (old_iter.HasNextInstanceField() || old_iter.HasNextStaticField()) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED), |
| StringPrintf("field '%s' (sig: %s) is missing!", |
| old_dex_file.GetFieldName(old_dex_file.GetFieldId( |
| old_iter.GetMemberIndex())), |
| old_dex_file.GetFieldTypeDescriptor(old_dex_file.GetFieldId( |
| old_iter.GetMemberIndex())))); |
| return false; |
| } |
| return true; |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckClass() { |
| // TODO Might just want to put it in a ObjPtr and NoSuspend assert. |
| art::StackHandleScope<1> hs(driver_->self_); |
| // Easy check that only 1 class def is present. |
| if (dex_file_->NumClassDefs() != 1) { |
| RecordFailure(ERR(ILLEGAL_ARGUMENT), |
| StringPrintf("Expected 1 class def in dex file but found %d", |
| dex_file_->NumClassDefs())); |
| return false; |
| } |
| // Get the ClassDef from the new DexFile. |
| // Since the dex file has only a single class def the index is always 0. |
| const art::DexFile::ClassDef& def = dex_file_->GetClassDef(0); |
| // Get the class as it is now. |
| art::Handle<art::mirror::Class> current_class(hs.NewHandle(GetMirrorClass())); |
| |
| // Check the access flags didn't change. |
| if (def.GetJavaAccessFlags() != (current_class->GetAccessFlags() & art::kAccValidClassFlags)) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_CLASS_MODIFIERS_CHANGED), |
| "Cannot change modifiers of class by redefinition"); |
| return false; |
| } |
| |
| // Check class name. |
| // These should have been checked by the dexfile verifier on load. |
| DCHECK_NE(def.class_idx_, art::dex::TypeIndex::Invalid()) << "Invalid type index"; |
| const char* descriptor = dex_file_->StringByTypeIdx(def.class_idx_); |
| DCHECK(descriptor != nullptr) << "Invalid dex file structure!"; |
| if (!current_class->DescriptorEquals(descriptor)) { |
| std::string storage; |
| RecordFailure(ERR(NAMES_DONT_MATCH), |
| StringPrintf("expected file to contain class called '%s' but found '%s'!", |
| current_class->GetDescriptor(&storage), |
| descriptor)); |
| return false; |
| } |
| if (current_class->IsObjectClass()) { |
| if (def.superclass_idx_ != art::dex::TypeIndex::Invalid()) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Superclass added!"); |
| return false; |
| } |
| } else { |
| const char* super_descriptor = dex_file_->StringByTypeIdx(def.superclass_idx_); |
| DCHECK(descriptor != nullptr) << "Invalid dex file structure!"; |
| if (!current_class->GetSuperClass()->DescriptorEquals(super_descriptor)) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Superclass changed"); |
| return false; |
| } |
| } |
| const art::DexFile::TypeList* interfaces = dex_file_->GetInterfacesList(def); |
| if (interfaces == nullptr) { |
| if (current_class->NumDirectInterfaces() != 0) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Interfaces added"); |
| return false; |
| } |
| } else { |
| DCHECK(!current_class->IsProxyClass()); |
| const art::DexFile::TypeList* current_interfaces = current_class->GetInterfaceTypeList(); |
| if (current_interfaces == nullptr || current_interfaces->Size() != interfaces->Size()) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Interfaces added or removed"); |
| return false; |
| } |
| // The order of interfaces is (barely) meaningful so we error if it changes. |
| const art::DexFile& orig_dex_file = current_class->GetDexFile(); |
| for (uint32_t i = 0; i < interfaces->Size(); i++) { |
| if (strcmp( |
| dex_file_->StringByTypeIdx(interfaces->GetTypeItem(i).type_idx_), |
| orig_dex_file.StringByTypeIdx(current_interfaces->GetTypeItem(i).type_idx_)) != 0) { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), |
| "Interfaces changed or re-ordered"); |
| return false; |
| } |
| } |
| } |
| LOG(WARNING) << "No verification is done on annotations of redefined classes."; |
| |
| return true; |
| } |
| |
| // TODO Move this to use IsRedefinable when that function is made. |
| bool Redefiner::ClassRedefinition::CheckRedefinable() { |
| std::string err; |
| art::StackHandleScope<1> hs(driver_->self_); |
| |
| art::Handle<art::mirror::Class> h_klass(hs.NewHandle(GetMirrorClass())); |
| jvmtiError res = Redefiner::GetClassRedefinitionError(h_klass, &err); |
| if (res != OK) { |
| RecordFailure(res, err); |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckRedefinitionIsValid() { |
| return CheckRedefinable() && |
| CheckClass() && |
| CheckSameFields() && |
| CheckSameMethods(); |
| } |
| |
| // A wrapper that lets us hold onto the arbitrary sized data needed for redefinitions in a |
| // reasonably sane way. This adds no fields to the normal ObjectArray. By doing this we can avoid |
| // having to deal with the fact that we need to hold an arbitrary number of references live. |
| class RedefinitionDataHolder { |
| public: |
| enum DataSlot : int32_t { |
| kSlotSourceClassLoader = 0, |
| kSlotJavaDexFile = 1, |
| kSlotNewDexFileCookie = 2, |
| kSlotNewDexCache = 3, |
| kSlotMirrorClass = 4, |
| kSlotOrigDexFile = 5, |
| |
| // Must be last one. |
| kNumSlots = 6, |
| }; |
| |
| // This needs to have a HandleScope passed in that is capable of creating a new Handle without |
| // overflowing. Only one handle will be created. This object has a lifetime identical to that of |
| // the passed in handle-scope. |
| RedefinitionDataHolder(art::StackHandleScope<1>* hs, |
| art::Runtime* runtime, |
| art::Thread* self, |
| int32_t num_redefinitions) REQUIRES_SHARED(art::Locks::mutator_lock_) : |
| arr_( |
| hs->NewHandle( |
| art::mirror::ObjectArray<art::mirror::Object>::Alloc( |
| self, |
| runtime->GetClassLinker()->GetClassRoot(art::ClassLinker::kObjectArrayClass), |
| num_redefinitions * kNumSlots))) {} |
| |
| bool IsNull() const REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return arr_.IsNull(); |
| } |
| |
| // TODO Maybe make an iterable view type to simplify using this. |
| art::mirror::ClassLoader* GetSourceClassLoader(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::down_cast<art::mirror::ClassLoader*>(GetSlot(klass_index, kSlotSourceClassLoader)); |
| } |
| art::mirror::Object* GetJavaDexFile(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return GetSlot(klass_index, kSlotJavaDexFile); |
| } |
| art::mirror::LongArray* GetNewDexFileCookie(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::down_cast<art::mirror::LongArray*>(GetSlot(klass_index, kSlotNewDexFileCookie)); |
| } |
| art::mirror::DexCache* GetNewDexCache(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::down_cast<art::mirror::DexCache*>(GetSlot(klass_index, kSlotNewDexCache)); |
| } |
| art::mirror::Class* GetMirrorClass(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::down_cast<art::mirror::Class*>(GetSlot(klass_index, kSlotMirrorClass)); |
| } |
| |
| art::mirror::ByteArray* GetOriginalDexFileBytes(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::down_cast<art::mirror::ByteArray*>(GetSlot(klass_index, kSlotOrigDexFile)); |
| } |
| |
| void SetSourceClassLoader(jint klass_index, art::mirror::ClassLoader* loader) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotSourceClassLoader, loader); |
| } |
| void SetJavaDexFile(jint klass_index, art::mirror::Object* dexfile) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotJavaDexFile, dexfile); |
| } |
| void SetNewDexFileCookie(jint klass_index, art::mirror::LongArray* cookie) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotNewDexFileCookie, cookie); |
| } |
| void SetNewDexCache(jint klass_index, art::mirror::DexCache* cache) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotNewDexCache, cache); |
| } |
| void SetMirrorClass(jint klass_index, art::mirror::Class* klass) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotMirrorClass, klass); |
| } |
| void SetOriginalDexFileBytes(jint klass_index, art::mirror::ByteArray* bytes) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotOrigDexFile, bytes); |
| } |
| |
| int32_t Length() const REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return arr_->GetLength() / kNumSlots; |
| } |
| |
| private: |
| mutable art::Handle<art::mirror::ObjectArray<art::mirror::Object>> arr_; |
| |
| art::mirror::Object* GetSlot(jint klass_index, |
| DataSlot slot) const REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| DCHECK_LT(klass_index, Length()); |
| return arr_->Get((kNumSlots * klass_index) + slot); |
| } |
| |
| void SetSlot(jint klass_index, |
| DataSlot slot, |
| art::ObjPtr<art::mirror::Object> obj) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| DCHECK(!art::Runtime::Current()->IsActiveTransaction()); |
| DCHECK_LT(klass_index, Length()); |
| arr_->Set<false>((kNumSlots * klass_index) + slot, obj); |
| } |
| |
| DISALLOW_COPY_AND_ASSIGN(RedefinitionDataHolder); |
| }; |
| |
| // TODO Stash and update soft failure state |
| bool Redefiner::ClassRedefinition::CheckVerification(int32_t klass_index, |
| const RedefinitionDataHolder& holder) { |
| DCHECK_EQ(dex_file_->NumClassDefs(), 1u); |
| art::StackHandleScope<2> hs(driver_->self_); |
| std::string error; |
| // TODO Make verification log level lower |
| art::verifier::MethodVerifier::FailureKind failure = |
| art::verifier::MethodVerifier::VerifyClass(driver_->self_, |
| dex_file_.get(), |
| hs.NewHandle(holder.GetNewDexCache(klass_index)), |
| hs.NewHandle(GetClassLoader()), |
| dex_file_->GetClassDef(0), /*class_def*/ |
| nullptr, /*compiler_callbacks*/ |
| false, /*allow_soft_failures*/ |
| /*log_level*/ |
| art::verifier::HardFailLogMode::kLogWarning, |
| &error); |
| bool passes = failure == art::verifier::MethodVerifier::kNoFailure; |
| if (!passes) { |
| RecordFailure(ERR(FAILS_VERIFICATION), "Failed to verify class. Error was: " + error); |
| } |
| return passes; |
| } |
| |
| // Looks through the previously allocated cookies to see if we need to update them with another new |
| // dexfile. This is so that even if multiple classes with the same classloader are redefined at |
| // once they are all added to the classloader. |
| bool Redefiner::ClassRedefinition::AllocateAndRememberNewDexFileCookie( |
| int32_t klass_index, |
| art::Handle<art::mirror::ClassLoader> source_class_loader, |
| art::Handle<art::mirror::Object> dex_file_obj, |
| /*out*/RedefinitionDataHolder* holder) { |
| art::StackHandleScope<2> hs(driver_->self_); |
| art::MutableHandle<art::mirror::LongArray> old_cookie( |
| hs.NewHandle<art::mirror::LongArray>(nullptr)); |
| bool has_older_cookie = false; |
| // See if we already have a cookie that a previous redefinition got from the same classloader. |
| for (int32_t i = 0; i < klass_index; i++) { |
| if (holder->GetSourceClassLoader(i) == source_class_loader.Get()) { |
| // Since every instance of this classloader should have the same cookie associated with it we |
| // can stop looking here. |
| has_older_cookie = true; |
| old_cookie.Assign(holder->GetNewDexFileCookie(i)); |
| break; |
| } |
| } |
| if (old_cookie.IsNull()) { |
| // No older cookie. Get it directly from the dex_file_obj |
| // We should not have seen this classloader elsewhere. |
| CHECK(!has_older_cookie); |
| old_cookie.Assign(ClassLoaderHelper::GetDexFileCookie(dex_file_obj)); |
| } |
| // Use the old cookie to generate the new one with the new DexFile* added in. |
| art::Handle<art::mirror::LongArray> |
| new_cookie(hs.NewHandle(ClassLoaderHelper::AllocateNewDexFileCookie(driver_->self_, |
| old_cookie, |
| dex_file_.get()))); |
| // Make sure the allocation worked. |
| if (new_cookie.IsNull()) { |
| return false; |
| } |
| |
| // Save the cookie. |
| holder->SetNewDexFileCookie(klass_index, new_cookie.Get()); |
| // If there are other copies of this same classloader we need to make sure that we all have the |
| // same cookie. |
| if (has_older_cookie) { |
| for (int32_t i = 0; i < klass_index; i++) { |
| // We will let the GC take care of the cookie we allocated for this one. |
| if (holder->GetSourceClassLoader(i) == source_class_loader.Get()) { |
| holder->SetNewDexFileCookie(i, new_cookie.Get()); |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| bool Redefiner::ClassRedefinition::FinishRemainingAllocations( |
| int32_t klass_index, /*out*/RedefinitionDataHolder* holder) { |
| art::ScopedObjectAccessUnchecked soa(driver_->self_); |
| art::StackHandleScope<2> hs(driver_->self_); |
| holder->SetMirrorClass(klass_index, GetMirrorClass()); |
| // This shouldn't allocate |
| art::Handle<art::mirror::ClassLoader> loader(hs.NewHandle(GetClassLoader())); |
| // The bootclasspath is handled specially so it doesn't have a j.l.DexFile. |
| if (!art::ClassLinker::IsBootClassLoader(soa, loader.Get())) { |
| holder->SetSourceClassLoader(klass_index, loader.Get()); |
| art::Handle<art::mirror::Object> dex_file_obj(hs.NewHandle( |
| ClassLoaderHelper::FindSourceDexFileObject(driver_->self_, loader))); |
| holder->SetJavaDexFile(klass_index, dex_file_obj.Get()); |
| if (dex_file_obj.Get() == nullptr) { |
| // TODO Better error msg. |
| RecordFailure(ERR(INTERNAL), "Unable to find dex file!"); |
| return false; |
| } |
| // Allocate the new dex file cookie. |
| if (!AllocateAndRememberNewDexFileCookie(klass_index, loader, dex_file_obj, holder)) { |
| driver_->self_->AssertPendingOOMException(); |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate dex file array for class loader"); |
| return false; |
| } |
| } |
| holder->SetNewDexCache(klass_index, CreateNewDexCache(loader)); |
| if (holder->GetNewDexCache(klass_index) == nullptr) { |
| driver_->self_->AssertPendingException(); |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate DexCache"); |
| return false; |
| } |
| |
| // We won't always need to set this field. |
| holder->SetOriginalDexFileBytes(klass_index, AllocateOrGetOriginalDexFileBytes()); |
| if (holder->GetOriginalDexFileBytes(klass_index) == nullptr) { |
| driver_->self_->AssertPendingOOMException(); |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate array for original dex file"); |
| return false; |
| } |
| return true; |
| } |
| |
| bool Redefiner::CheckAllRedefinitionAreValid() { |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| if (!redef.CheckRedefinitionIsValid()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool Redefiner::EnsureAllClassAllocationsFinished() { |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| if (!redef.EnsureClassAllocationsFinished()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool Redefiner::FinishAllRemainingAllocations(RedefinitionDataHolder& holder) { |
| int32_t cnt = 0; |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| // Allocate the data this redefinition requires. |
| if (!redef.FinishRemainingAllocations(cnt, &holder)) { |
| return false; |
| } |
| cnt++; |
| } |
| return true; |
| } |
| |
| void Redefiner::ClassRedefinition::ReleaseDexFile() { |
| dex_file_.release(); |
| } |
| |
| void Redefiner::ReleaseAllDexFiles() { |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| redef.ReleaseDexFile(); |
| } |
| } |
| |
| bool Redefiner::CheckAllClassesAreVerified(const RedefinitionDataHolder& holder) { |
| int32_t cnt = 0; |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| if (!redef.CheckVerification(cnt, holder)) { |
| return false; |
| } |
| cnt++; |
| } |
| return true; |
| } |
| |
| jvmtiError Redefiner::Run() { |
| art::StackHandleScope<1> hs(self_); |
| // Allocate an array to hold onto all java temporary objects associated with this redefinition. |
| // We will let this be collected after the end of this function. |
| RedefinitionDataHolder holder(&hs, runtime_, self_, redefinitions_.size()); |
| if (holder.IsNull()) { |
| self_->AssertPendingOOMException(); |
| self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Could not allocate storage for temporaries"); |
| return result_; |
| } |
| |
| // First we just allocate the ClassExt and its fields that we need. These can be updated |
| // atomically without any issues (since we allocate the map arrays as empty) so we don't bother |
| // doing a try loop. The other allocations we need to ensure that nothing has changed in the time |
| // between allocating them and pausing all threads before we can update them so we need to do a |
| // try loop. |
| if (!CheckAllRedefinitionAreValid() || |
| !EnsureAllClassAllocationsFinished() || |
| !FinishAllRemainingAllocations(holder) || |
| !CheckAllClassesAreVerified(holder)) { |
| // TODO Null out the ClassExt fields we allocated (if possible, might be racing with another |
| // redefineclass call which made it even bigger. Leak shouldn't be huge (2x array of size |
| // declared_methods_.length) but would be good to get rid of. All other allocations should be |
| // cleaned up by the GC eventually. |
| return result_; |
| } |
| int32_t counter = 0; |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| if (holder.GetSourceClassLoader(counter) == nullptr) { |
| runtime_->GetClassLinker()->AppendToBootClassPath(self_, redef.GetDexFile()); |
| } |
| counter++; |
| } |
| // Disable GC and wait for it to be done if we are a moving GC. This is fine since we are done |
| // allocating so no deadlocks. |
| art::gc::Heap* heap = runtime_->GetHeap(); |
| if (heap->IsGcConcurrentAndMoving()) { |
| // GC moving objects can cause deadlocks as we are deoptimizing the stack. |
| heap->IncrementDisableMovingGC(self_); |
| } |
| // Do transition to final suspension |
| // TODO We might want to give this its own suspended state! |
| // TODO This isn't right. We need to change state without any chance of suspend ideally! |
| self_->TransitionFromRunnableToSuspended(art::ThreadState::kNative); |
| runtime_->GetThreadList()->SuspendAll( |
| "Final installation of redefined Classes!", /*long_suspend*/true); |
| // TODO We need to invalidate all breakpoints in the redefined class with the debugger. |
| // TODO We need to deal with any instrumentation/debugger deoptimized_methods_. |
| // TODO We need to update all debugger MethodIDs so they note the method they point to is |
| // obsolete or implement some other well defined semantics. |
| // TODO We need to decide on & implement semantics for JNI jmethodids when we redefine methods. |
| counter = 0; |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| art::ScopedAssertNoThreadSuspension nts("Updating runtime objects for redefinition"); |
| if (holder.GetSourceClassLoader(counter) != nullptr) { |
| ClassLoaderHelper::UpdateJavaDexFile(holder.GetJavaDexFile(counter), |
| holder.GetNewDexFileCookie(counter)); |
| } |
| art::mirror::Class* klass = holder.GetMirrorClass(counter); |
| // TODO Rewrite so we don't do a stack walk for each and every class. |
| redef.FindAndAllocateObsoleteMethods(klass); |
| redef.UpdateClass(klass, holder.GetNewDexCache(counter), |
| holder.GetOriginalDexFileBytes(counter)); |
| counter++; |
| } |
| // TODO Verify the new Class. |
| // TODO Shrink the obsolete method maps if possible? |
| // TODO find appropriate class loader. |
| // TODO Put this into a scoped thing. |
| runtime_->GetThreadList()->ResumeAll(); |
| // Get back shared mutator lock as expected for return. |
| self_->TransitionFromSuspendedToRunnable(); |
| // TODO Do the dex_file release at a more reasonable place. This works but it muddles who really |
| // owns the DexFile and when ownership is transferred. |
| ReleaseAllDexFiles(); |
| if (heap->IsGcConcurrentAndMoving()) { |
| heap->DecrementDisableMovingGC(self_); |
| } |
| return OK; |
| } |
| |
| void Redefiner::ClassRedefinition::UpdateMethods(art::ObjPtr<art::mirror::Class> mclass, |
| art::ObjPtr<art::mirror::DexCache> new_dex_cache, |
| const art::DexFile::ClassDef& class_def) { |
| art::ClassLinker* linker = driver_->runtime_->GetClassLinker(); |
| art::PointerSize image_pointer_size = linker->GetImagePointerSize(); |
| const art::DexFile::TypeId& declaring_class_id = dex_file_->GetTypeId(class_def.class_idx_); |
| const art::DexFile& old_dex_file = mclass->GetDexFile(); |
| // Update methods. |
| for (art::ArtMethod& method : mclass->GetMethods(image_pointer_size)) { |
| const art::DexFile::StringId* new_name_id = dex_file_->FindStringId(method.GetName()); |
| art::dex::TypeIndex method_return_idx = |
| dex_file_->GetIndexForTypeId(*dex_file_->FindTypeId(method.GetReturnTypeDescriptor())); |
| const auto* old_type_list = method.GetParameterTypeList(); |
| std::vector<art::dex::TypeIndex> new_type_list; |
| for (uint32_t i = 0; old_type_list != nullptr && i < old_type_list->Size(); i++) { |
| new_type_list.push_back( |
| dex_file_->GetIndexForTypeId( |
| *dex_file_->FindTypeId( |
| old_dex_file.GetTypeDescriptor( |
| old_dex_file.GetTypeId( |
| old_type_list->GetTypeItem(i).type_idx_))))); |
| } |
| const art::DexFile::ProtoId* proto_id = dex_file_->FindProtoId(method_return_idx, |
| new_type_list); |
| // TODO Return false, cleanup. |
| CHECK(proto_id != nullptr || old_type_list == nullptr); |
| const art::DexFile::MethodId* method_id = dex_file_->FindMethodId(declaring_class_id, |
| *new_name_id, |
| *proto_id); |
| // TODO Return false, cleanup. |
| CHECK(method_id != nullptr); |
| uint32_t dex_method_idx = dex_file_->GetIndexForMethodId(*method_id); |
| method.SetDexMethodIndex(dex_method_idx); |
| linker->SetEntryPointsToInterpreter(&method); |
| method.SetCodeItemOffset(dex_file_->FindCodeItemOffset(class_def, dex_method_idx)); |
| method.SetDexCacheResolvedMethods(new_dex_cache->GetResolvedMethods(), image_pointer_size); |
| // Notify the jit that this method is redefined. |
| art::jit::Jit* jit = driver_->runtime_->GetJit(); |
| if (jit != nullptr) { |
| jit->GetCodeCache()->NotifyMethodRedefined(&method); |
| } |
| } |
| } |
| |
| void Redefiner::ClassRedefinition::UpdateFields(art::ObjPtr<art::mirror::Class> mclass) { |
| // TODO The IFields & SFields pointers should be combined like the methods_ arrays were. |
| for (auto fields_iter : {mclass->GetIFields(), mclass->GetSFields()}) { |
| for (art::ArtField& field : fields_iter) { |
| std::string declaring_class_name; |
| const art::DexFile::TypeId* new_declaring_id = |
| dex_file_->FindTypeId(field.GetDeclaringClass()->GetDescriptor(&declaring_class_name)); |
| const art::DexFile::StringId* new_name_id = dex_file_->FindStringId(field.GetName()); |
| const art::DexFile::TypeId* new_type_id = dex_file_->FindTypeId(field.GetTypeDescriptor()); |
| // TODO Handle error, cleanup. |
| CHECK(new_name_id != nullptr && new_type_id != nullptr && new_declaring_id != nullptr); |
| const art::DexFile::FieldId* new_field_id = |
| dex_file_->FindFieldId(*new_declaring_id, *new_name_id, *new_type_id); |
| CHECK(new_field_id != nullptr); |
| // We only need to update the index since the other data in the ArtField cannot be updated. |
| field.SetDexFieldIndex(dex_file_->GetIndexForFieldId(*new_field_id)); |
| } |
| } |
| } |
| |
| // Performs updates to class that will allow us to verify it. |
| void Redefiner::ClassRedefinition::UpdateClass( |
| art::ObjPtr<art::mirror::Class> mclass, |
| art::ObjPtr<art::mirror::DexCache> new_dex_cache, |
| art::ObjPtr<art::mirror::ByteArray> original_dex_file) { |
| DCHECK_EQ(dex_file_->NumClassDefs(), 1u); |
| const art::DexFile::ClassDef& class_def = dex_file_->GetClassDef(0); |
| UpdateMethods(mclass, new_dex_cache, class_def); |
| UpdateFields(mclass); |
| |
| // Update the class fields. |
| // Need to update class last since the ArtMethod gets its DexFile from the class (which is needed |
| // to call GetReturnTypeDescriptor and GetParameterTypeList above). |
| mclass->SetDexCache(new_dex_cache.Ptr()); |
| mclass->SetDexClassDefIndex(dex_file_->GetIndexForClassDef(class_def)); |
| mclass->SetDexTypeIndex(dex_file_->GetIndexForTypeId(*dex_file_->FindTypeId(class_sig_.c_str()))); |
| art::ObjPtr<art::mirror::ClassExt> ext(mclass->GetExtData()); |
| CHECK(!ext.IsNull()); |
| ext->SetOriginalDexFileBytes(original_dex_file); |
| } |
| |
| // This function does all (java) allocations we need to do for the Class being redefined. |
| // TODO Change this name maybe? |
| bool Redefiner::ClassRedefinition::EnsureClassAllocationsFinished() { |
| art::StackHandleScope<2> hs(driver_->self_); |
| art::Handle<art::mirror::Class> klass(hs.NewHandle( |
| driver_->self_->DecodeJObject(klass_)->AsClass())); |
| if (klass.Get() == nullptr) { |
| RecordFailure(ERR(INVALID_CLASS), "Unable to decode class argument!"); |
| return false; |
| } |
| // Allocate the classExt |
| art::Handle<art::mirror::ClassExt> ext(hs.NewHandle(klass->EnsureExtDataPresent(driver_->self_))); |
| if (ext.Get() == nullptr) { |
| // No memory. Clear exception (it's not useful) and return error. |
| // TODO This doesn't need to be fatal. We could just not support obsolete methods after hitting |
| // this case. |
| driver_->self_->AssertPendingOOMException(); |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Could not allocate ClassExt"); |
| return false; |
| } |
| // Allocate the 2 arrays that make up the obsolete methods map. Since the contents of the arrays |
| // are only modified when all threads (other than the modifying one) are suspended we don't need |
| // to worry about missing the unsyncronized writes to the array. We do synchronize when setting it |
| // however, since that can happen at any time. |
| // TODO Clear these after we walk the stacks in order to free them in the (likely?) event there |
| // are no obsolete methods. |
| { |
| art::ObjectLock<art::mirror::ClassExt> lock(driver_->self_, ext); |
| if (!ext->ExtendObsoleteArrays( |
| driver_->self_, klass->GetDeclaredMethodsSlice(art::kRuntimePointerSize).size())) { |
| // OOM. Clear exception and return error. |
| driver_->self_->AssertPendingOOMException(); |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate/extend obsolete methods map"); |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| } // namespace openjdkjvmti |
