| /* 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/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.h" |
| #include "mirror/class_ext.h" |
| #include "mirror/object.h" |
| #include "object_lock.h" |
| #include "runtime.h" |
| #include "ScopedLocalRef.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, |
| /*out*/bool* success, |
| /*out*/std::string* error_msg) |
| : StackVisitor(thread, |
| /*context*/nullptr, |
| StackVisitor::StackWalkKind::kIncludeInlinedFrames), |
| allocator_(allocator), |
| obsoleted_methods_(obsoleted_methods), |
| obsolete_maps_(obsolete_maps), |
| success_(success), |
| is_runtime_frame_(false), |
| error_msg_(error_msg) { |
| *success_ = true; |
| } |
| |
| ~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 bool 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, |
| /*out*/std::string* error_msg) REQUIRES(art::Locks::mutator_lock_) { |
| bool success = true; |
| ObsoleteMethodStackVisitor visitor(thread, |
| allocator, |
| obsoleted_methods, |
| obsolete_maps, |
| &success, |
| error_msg); |
| visitor.WalkStack(); |
| if (!success) { |
| RestoreFrames(thread, *obsolete_maps, error_msg); |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| static void RestoreFrames( |
| art::Thread* thread ATTRIBUTE_UNUSED, |
| const std::unordered_map<art::ArtMethod*, art::ArtMethod*>& obsolete_maps ATTRIBUTE_UNUSED, |
| std::string* error_msg) |
| REQUIRES(art::Locks::mutator_lock_) { |
| LOG(FATAL) << "Restoring stack frames is not yet supported. Error was: " << *error_msg; |
| } |
| |
| bool VisitFrame() OVERRIDE REQUIRES(art::Locks::mutator_lock_) { |
| art::ArtMethod* old_method = GetMethod(); |
| // TODO REMOVE once either current_method doesn't stick around through suspend points or deopt |
| // works through runtime methods. |
| bool prev_was_runtime_frame_ = is_runtime_frame_; |
| is_runtime_frame_ = old_method->IsRuntimeMethod(); |
| if (obsoleted_methods_.find(old_method) != obsoleted_methods_.end()) { |
| // The check below works since when we deoptimize we set shadow frames for all frames until a |
| // native/runtime transition and for those set the return PC to a function that will complete |
| // the deoptimization. This does leave us with the unfortunate side-effect that frames just |
| // below runtime frames cannot be deoptimized at the moment. |
| // TODO REMOVE once either current_method doesn't stick around through suspend points or deopt |
| // works through runtime methods. |
| // TODO b/33616143 |
| if (!IsShadowFrame() && prev_was_runtime_frame_) { |
| *error_msg_ = StringPrintf("Deoptimization failed due to runtime method in stack."); |
| *success_ = false; |
| return false; |
| } |
| // 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); |
| if (method_storage == nullptr) { |
| *success_ = false; |
| *error_msg_ = StringPrintf("Unable to allocate storage for obsolete version of '%s'", |
| old_method->PrettyMethod().c_str()); |
| return false; |
| } |
| 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(); |
| 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_; |
| bool* success_; |
| // TODO REMOVE once either current_method doesn't stick around through suspend points or deopt |
| // works through runtime methods. |
| bool is_runtime_frame_; |
| std::string* error_msg_; |
| }; |
| |
| // 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, |
| 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; |
| } |
| |
| // TODO This should handle doing multiple classes at once so we need to do less cleanup when things |
| // go wrong. |
| jvmtiError Redefiner::RedefineClass(ArtJvmTiEnv* env, |
| art::Runtime* runtime, |
| art::Thread* self, |
| jclass klass, |
| const std::string& original_dex_location, |
| jint data_len, |
| unsigned char* dex_data, |
| std::string* error_msg) { |
| std::unique_ptr<art::MemMap> map(MoveDataToMemMap(original_dex_location, |
| data_len, |
| dex_data, |
| error_msg)); |
| std::ostringstream os; |
| char* generic_ptr_unused = nullptr; |
| char* signature_ptr = nullptr; |
| if (env->GetClassSignature(klass, &signature_ptr, &generic_ptr_unused) != OK) { |
| signature_ptr = const_cast<char*>("<UNKNOWN CLASS>"); |
| } |
| if (map.get() == nullptr) { |
| os << "Failed to create anonymous mmap for modified dex file of class " << signature_ptr |
| << "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 " << signature_ptr << ": " << *error_msg; |
| *error_msg = os.str(); |
| return ERR(INVALID_CLASS_FORMAT); |
| } |
| // 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. |
| art::ScopedObjectAccess soa(self); |
| art::StackHandleScope<1> hs(self); |
| Redefiner r(runtime, self, klass, signature_ptr, dex_file, error_msg); |
| // Lock around this class to avoid races. |
| art::ObjectLock<art::mirror::Class> lock(self, hs.NewHandle(r.GetMirrorClass())); |
| return r.Run(); |
| } |
| |
| // TODO *MAJOR* This should return the actual source java.lang.DexFile object for the klass. |
| // TODO Make mirror of DexFile and associated types to make this less hellish. |
| // TODO Make mirror of BaseDexClassLoader and associated types to make this less hellish. |
| art::mirror::Object* Redefiner::FindSourceDexFileObject( |
| art::Handle<art::mirror::ClassLoader> loader) { |
| const char* dex_path_list_element_array_name = "[Ldalvik/system/DexPathList$Element;"; |
| const char* dex_path_list_element_name = "Ldalvik/system/DexPathList$Element;"; |
| const char* dex_file_name = "Ldalvik/system/DexFile;"; |
| const char* dex_path_list_name = "Ldalvik/system/DexPathList;"; |
| const char* dex_class_loader_name = "Ldalvik/system/BaseDexClassLoader;"; |
| |
| CHECK(!self_->IsExceptionPending()); |
| art::StackHandleScope<11> hs(self_); |
| art::ClassLinker* class_linker = runtime_->GetClassLinker(); |
| |
| art::Handle<art::mirror::ClassLoader> null_loader(hs.NewHandle<art::mirror::ClassLoader>( |
| nullptr)); |
| art::Handle<art::mirror::Class> base_dex_loader_class(hs.NewHandle(class_linker->FindClass( |
| self_, dex_class_loader_name, null_loader))); |
| |
| // Get all the ArtFields so we can look in the BaseDexClassLoader |
| art::ArtField* path_list_field = base_dex_loader_class->FindDeclaredInstanceField( |
| "pathList", dex_path_list_name); |
| CHECK(path_list_field != nullptr); |
| |
| art::ArtField* dex_path_list_element_field = |
| class_linker->FindClass(self_, dex_path_list_name, null_loader) |
| ->FindDeclaredInstanceField("dexElements", dex_path_list_element_array_name); |
| CHECK(dex_path_list_element_field != nullptr); |
| |
| art::ArtField* element_dex_file_field = |
| class_linker->FindClass(self_, dex_path_list_element_name, null_loader) |
| ->FindDeclaredInstanceField("dexFile", dex_file_name); |
| CHECK(element_dex_file_field != nullptr); |
| |
| // Check if loader is a BaseDexClassLoader |
| art::Handle<art::mirror::Class> loader_class(hs.NewHandle(loader->GetClass())); |
| if (!loader_class->IsSubClass(base_dex_loader_class.Get())) { |
| LOG(ERROR) << "The classloader is not a BaseDexClassLoader which is currently the only " |
| << "supported class loader type!"; |
| return nullptr; |
| } |
| // Start navigating the fields of the loader (now known to be a BaseDexClassLoader derivative) |
| art::Handle<art::mirror::Object> path_list( |
| hs.NewHandle(path_list_field->GetObject(loader.Get()))); |
| CHECK(path_list.Get() != nullptr); |
| CHECK(!self_->IsExceptionPending()); |
| art::Handle<art::mirror::ObjectArray<art::mirror::Object>> dex_elements_list(hs.NewHandle( |
| dex_path_list_element_field->GetObject(path_list.Get())-> |
| AsObjectArray<art::mirror::Object>())); |
| CHECK(!self_->IsExceptionPending()); |
| CHECK(dex_elements_list.Get() != nullptr); |
| size_t num_elements = dex_elements_list->GetLength(); |
| art::MutableHandle<art::mirror::Object> current_element( |
| hs.NewHandle<art::mirror::Object>(nullptr)); |
| art::MutableHandle<art::mirror::Object> first_dex_file( |
| hs.NewHandle<art::mirror::Object>(nullptr)); |
| // Iterate over the DexPathList$Element to find the right one |
| // TODO Or not ATM just return the first one. |
| for (size_t i = 0; i < num_elements; i++) { |
| current_element.Assign(dex_elements_list->Get(i)); |
| CHECK(current_element.Get() != nullptr); |
| CHECK(!self_->IsExceptionPending()); |
| CHECK(dex_elements_list.Get() != nullptr); |
| CHECK_EQ(current_element->GetClass(), class_linker->FindClass(self_, |
| dex_path_list_element_name, |
| null_loader)); |
| // TODO It would be cleaner to put the art::DexFile into the dalvik.system.DexFile the class |
| // comes from but it is more annoying because we would need to find this class. It is not |
| // necessary for proper function since we just need to be in front of the classes old dex file |
| // in the path. |
| first_dex_file.Assign(element_dex_file_field->GetObject(current_element.Get())); |
| if (first_dex_file.Get() != nullptr) { |
| return first_dex_file.Get(); |
| } |
| } |
| return nullptr; |
| } |
| |
| art::mirror::Class* Redefiner::GetMirrorClass() { |
| return self_->DecodeJObject(klass_)->AsClass(); |
| } |
| |
| art::mirror::ClassLoader* Redefiner::GetClassLoader() { |
| return GetMirrorClass()->GetClassLoader(); |
| } |
| |
| art::mirror::DexCache* Redefiner::CreateNewDexCache(art::Handle<art::mirror::ClassLoader> loader) { |
| return runtime_->GetClassLinker()->RegisterDexFile(*dex_file_, loader.Get()); |
| } |
| |
| // TODO Really wishing I had that mirror of java.lang.DexFile now. |
| art::mirror::LongArray* Redefiner::AllocateDexFileCookie( |
| art::Handle<art::mirror::Object> java_dex_file_obj) { |
| art::StackHandleScope<2> hs(self_); |
| // mCookie is nulled out if the DexFile has been closed but mInternalCookie sticks around until |
| // the object is finalized. Since they always point to the same array if mCookie is not null we |
| // just use the mInternalCookie field. We will update one or both of these fields later. |
| // TODO Should I get the class from the classloader or directly? |
| art::ArtField* internal_cookie_field = java_dex_file_obj->GetClass()->FindDeclaredInstanceField( |
| "mInternalCookie", "Ljava/lang/Object;"); |
| // TODO Add check that mCookie is either null or same as mInternalCookie |
| CHECK(internal_cookie_field != nullptr); |
| art::Handle<art::mirror::LongArray> cookie( |
| hs.NewHandle(internal_cookie_field->GetObject(java_dex_file_obj.Get())->AsLongArray())); |
| // TODO Maybe make these non-fatal. |
| CHECK(cookie.Get() != nullptr); |
| CHECK_GE(cookie->GetLength(), 1); |
| art::Handle<art::mirror::LongArray> new_cookie( |
| hs.NewHandle(art::mirror::LongArray::Alloc(self_, cookie->GetLength() + 1))); |
| if (new_cookie.Get() == nullptr) { |
| self_->AssertPendingOOMException(); |
| return nullptr; |
| } |
| // Copy the oat-dex field at the start. |
| // TODO Should I clear this field? |
| // TODO This is a really crappy thing here with the first element being different. |
| new_cookie->SetWithoutChecks<false>(0, cookie->GetWithoutChecks(0)); |
| new_cookie->SetWithoutChecks<false>( |
| 1, static_cast<int64_t>(reinterpret_cast<intptr_t>(dex_file_.get()))); |
| new_cookie->Memcpy(2, cookie.Get(), 1, cookie->GetLength() - 1); |
| return new_cookie.Get(); |
| } |
| |
| void Redefiner::RecordFailure(jvmtiError result, const std::string& error_msg) { |
| *error_msg_ = StringPrintf("Unable to perform redefinition of '%s': %s", |
| class_sig_, |
| error_msg.c_str()); |
| result_ = result; |
| } |
| |
| bool Redefiner::FinishRemainingAllocations( |
| /*out*/art::MutableHandle<art::mirror::ClassLoader>* source_class_loader, |
| /*out*/art::MutableHandle<art::mirror::Object>* java_dex_file_obj, |
| /*out*/art::MutableHandle<art::mirror::LongArray>* new_dex_file_cookie, |
| /*out*/art::MutableHandle<art::mirror::DexCache>* new_dex_cache) { |
| art::StackHandleScope<4> hs(self_); |
| // This shouldn't allocate |
| art::Handle<art::mirror::ClassLoader> loader(hs.NewHandle(GetClassLoader())); |
| if (loader.Get() == nullptr) { |
| // TODO Better error msg. |
| RecordFailure(ERR(INTERNAL), "Unable to find class loader!"); |
| return false; |
| } |
| art::Handle<art::mirror::Object> dex_file_obj(hs.NewHandle(FindSourceDexFileObject(loader))); |
| if (dex_file_obj.Get() == nullptr) { |
| // TODO Better error msg. |
| RecordFailure(ERR(INTERNAL), "Unable to find class loader!"); |
| return false; |
| } |
| art::Handle<art::mirror::LongArray> new_cookie(hs.NewHandle(AllocateDexFileCookie(dex_file_obj))); |
| if (new_cookie.Get() == nullptr) { |
| self_->AssertPendingOOMException(); |
| self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate dex file array for class loader"); |
| return false; |
| } |
| art::Handle<art::mirror::DexCache> dex_cache(hs.NewHandle(CreateNewDexCache(loader))); |
| if (dex_cache.Get() == nullptr) { |
| self_->AssertPendingOOMException(); |
| self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate DexCache"); |
| return false; |
| } |
| source_class_loader->Assign(loader.Get()); |
| java_dex_file_obj->Assign(dex_file_obj.Get()); |
| new_dex_file_cookie->Assign(new_cookie.Get()); |
| new_dex_cache->Assign(dex_cache.Get()); |
| return true; |
| } |
| |
| struct CallbackCtx { |
| Redefiner* const r; |
| art::LinearAlloc* allocator; |
| std::unordered_map<art::ArtMethod*, art::ArtMethod*> obsolete_map; |
| std::unordered_set<art::ArtMethod*> obsolete_methods; |
| bool success; |
| std::string* error_msg; |
| |
| CallbackCtx(Redefiner* self, art::LinearAlloc* alloc, std::string* error) |
| : r(self), allocator(alloc), success(true), error_msg(error) {} |
| }; |
| |
| void DoRestoreObsoleteMethodsCallback(art::Thread* t, void* vdata) NO_THREAD_SAFETY_ANALYSIS { |
| CallbackCtx* data = reinterpret_cast<CallbackCtx*>(vdata); |
| ObsoleteMethodStackVisitor::RestoreFrames(t, data->obsolete_map, data->error_msg); |
| } |
| |
| void DoAllocateObsoleteMethodsCallback(art::Thread* t, void* vdata) NO_THREAD_SAFETY_ANALYSIS { |
| CallbackCtx* data = reinterpret_cast<CallbackCtx*>(vdata); |
| if (data->success) { |
| // Don't do anything if we already failed once. |
| data->success = ObsoleteMethodStackVisitor::UpdateObsoleteFrames(t, |
| data->allocator, |
| data->obsolete_methods, |
| &data->obsolete_map, |
| data->error_msg); |
| } |
| } |
| |
| // This creates any ArtMethod* structures needed for obsolete methods and ensures that the stack is |
| // updated so they will be run. |
| bool Redefiner::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); |
| CallbackCtx ctx(this, art_klass->GetClassLoader()->GetAllocator(), error_msg_); |
| // Add all the declared methods to the map |
| for (auto& m : art_klass->GetDeclaredMethods(art::kRuntimePointerSize)) { |
| ctx.obsolete_methods.insert(&m); |
| } |
| for (art::ArtMethod* old_method : ctx.obsolete_methods) { |
| if (old_method->IsIntrinsic()) { |
| *error_msg_ = StringPrintf("Method '%s' is intrinsic and cannot be made obsolete!", |
| old_method->PrettyMethod().c_str()); |
| return false; |
| } |
| } |
| { |
| art::MutexLock mu(self_, *art::Locks::thread_list_lock_); |
| art::ThreadList* list = art::Runtime::Current()->GetThreadList(); |
| list->ForEach(DoAllocateObsoleteMethodsCallback, static_cast<void*>(&ctx)); |
| if (!ctx.success) { |
| list->ForEach(DoRestoreObsoleteMethodsCallback, static_cast<void*>(&ctx)); |
| return false; |
| } |
| } |
| FillObsoleteMethodMap(art_klass, ctx.obsolete_map); |
| return true; |
| } |
| |
| // 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::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++; |
| } |
| } |
| |
| // TODO It should be possible to only deoptimize the specific obsolete methods. |
| // TODO ReJitEverything can (sort of) fail. In certain cases it will skip deoptimizing some frames. |
| // If one of these frames is an obsolete method we have a problem. b/33616143 |
| // TODO This shouldn't be necessary once we can ensure that the current method is not kept in |
| // registers across suspend points. |
| // TODO Pending b/33630159 |
| void Redefiner::EnsureObsoleteMethodsAreDeoptimized() { |
| art::ScopedAssertNoThreadSuspension nts("Deoptimizing everything!"); |
| art::instrumentation::Instrumentation* i = runtime_->GetInstrumentation(); |
| i->ReJitEverything("libOpenJkdJvmti - Class Redefinition"); |
| } |
| |
| bool Redefiner::CheckClass() { |
| // TODO Might just want to put it in a ObjPtr and NoSuspend assert. |
| art::StackHandleScope<1> hs(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::CheckRedefinable() { |
| art::ObjPtr<art::mirror::Class> klass(GetMirrorClass()); |
| if (klass->IsPrimitive()) { |
| RecordFailure(ERR(UNMODIFIABLE_CLASS), |
| "Modification of primitive classes is not supported"); |
| return false; |
| } else if (klass->IsInterface()) { |
| RecordFailure(ERR(UNMODIFIABLE_CLASS), |
| "Modification of Interface classes is currently not supported"); |
| return false; |
| } else if (klass->IsArrayClass()) { |
| RecordFailure(ERR(UNMODIFIABLE_CLASS), |
| "Modification of Array classes is not supported"); |
| return false; |
| } else if (klass->IsProxyClass()) { |
| RecordFailure(ERR(UNMODIFIABLE_CLASS), |
| "Modification of proxy classes is not supported"); |
| return false; |
| } |
| |
| // 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 true; |
| } |
| |
| bool Redefiner::CheckRedefinitionIsValid() { |
| return CheckRedefinable() && |
| CheckClass() && |
| CheckSameFields() && |
| CheckSameMethods(); |
| } |
| |
| jvmtiError Redefiner::Run() { |
| art::StackHandleScope<5> hs(self_); |
| // TODO We might want to have a global lock (or one based on the class being redefined at least) |
| // in order to make cleanup easier. Not a huge deal though. |
| // |
| // 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 (!CheckRedefinitionIsValid() || !EnsureClassAllocationsFinished()) { |
| return result_; |
| } |
| art::MutableHandle<art::mirror::ClassLoader> source_class_loader( |
| hs.NewHandle<art::mirror::ClassLoader>(nullptr)); |
| art::MutableHandle<art::mirror::Object> java_dex_file( |
| hs.NewHandle<art::mirror::Object>(nullptr)); |
| art::MutableHandle<art::mirror::LongArray> new_dex_file_cookie( |
| hs.NewHandle<art::mirror::LongArray>(nullptr)); |
| art::MutableHandle<art::mirror::DexCache> new_dex_cache( |
| hs.NewHandle<art::mirror::DexCache>(nullptr)); |
| if (!FinishRemainingAllocations(&source_class_loader, |
| &java_dex_file, |
| &new_dex_file_cookie, |
| &new_dex_cache)) { |
| // 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. |
| // new_dex_file_cookie & new_dex_cache should be cleaned up by the GC. |
| return result_; |
| } |
| // Get the mirror class now that we aren't allocating anymore. |
| art::Handle<art::mirror::Class> art_class(hs.NewHandle(GetMirrorClass())); |
| // 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_); |
| } |
| // Enable assertion that this thread isn't interrupted during this installation. |
| // After this we will need to do real cleanup in case of failure. Prior to this we could simply |
| // return and would let everything get cleaned up or harmlessly leaked. |
| // 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 Class!", /*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. |
| // TODO Might want to move this into a different type. |
| // Now we reach the part where we must do active cleanup if something fails. |
| // TODO We should really Retry if this fails instead of simply aborting. |
| // Set the new DexFileCookie returns the original so we can fix it back up if redefinition fails |
| art::ObjPtr<art::mirror::LongArray> original_dex_file_cookie(nullptr); |
| if (!UpdateJavaDexFile(java_dex_file.Get(), |
| new_dex_file_cookie.Get(), |
| &original_dex_file_cookie) || |
| !FindAndAllocateObsoleteMethods(art_class.Get())) { |
| // Release suspendAll |
| runtime_->GetThreadList()->ResumeAll(); |
| // Get back shared mutator lock as expected for return. |
| self_->TransitionFromSuspendedToRunnable(); |
| if (heap->IsGcConcurrentAndMoving()) { |
| heap->DecrementDisableMovingGC(self_); |
| } |
| return result_; |
| } |
| if (!UpdateClass(art_class.Get(), new_dex_cache.Get())) { |
| // TODO Should have some form of scope to do this. |
| RestoreJavaDexFile(java_dex_file.Get(), original_dex_file_cookie); |
| // Release suspendAll |
| runtime_->GetThreadList()->ResumeAll(); |
| // Get back shared mutator lock as expected for return. |
| self_->TransitionFromSuspendedToRunnable(); |
| if (heap->IsGcConcurrentAndMoving()) { |
| heap->DecrementDisableMovingGC(self_); |
| } |
| return result_; |
| } |
| // Ensure that obsolete methods are deoptimized. This is needed since optimized methods may have |
| // pointers to their ArtMethod's stashed in registers that they then use to attempt to hit the |
| // DexCache. |
| // TODO This can fail (leave some methods optimized) near runtime methods (including |
| // quick-to-interpreter transition function). |
| // TODO We probably don't need this at all once we have a way to ensure that the |
| // current_art_method is never stashed in a (physical) register by the JIT and lost to the |
| // stack-walker. |
| EnsureObsoleteMethodsAreDeoptimized(); |
| // TODO Verify the new Class. |
| // TODO Failure then undo updates to 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. |
| dex_file_.release(); |
| if (heap->IsGcConcurrentAndMoving()) { |
| heap->DecrementDisableMovingGC(self_); |
| } |
| return OK; |
| } |
| |
| void Redefiner::RestoreJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file, |
| art::ObjPtr<art::mirror::LongArray> orig_cookie) { |
| art::ArtField* internal_cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField( |
| "mInternalCookie", "Ljava/lang/Object;"); |
| art::ArtField* cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField( |
| "mCookie", "Ljava/lang/Object;"); |
| art::ObjPtr<art::mirror::LongArray> new_cookie( |
| cookie_field->GetObject(java_dex_file)->AsLongArray()); |
| internal_cookie_field->SetObject<false>(java_dex_file, orig_cookie); |
| if (!new_cookie.IsNull()) { |
| cookie_field->SetObject<false>(java_dex_file, orig_cookie); |
| } |
| } |
| |
| bool Redefiner::UpdateMethods(art::ObjPtr<art::mirror::Class> mclass, |
| art::ObjPtr<art::mirror::DexCache> new_dex_cache, |
| const art::DexFile::ClassDef& class_def) { |
| art::ClassLinker* linker = 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); |
| method.SetDexCacheResolvedTypes(new_dex_cache->GetResolvedTypes(), image_pointer_size); |
| // Notify the jit that this method is redefined. |
| art::jit::Jit* jit = runtime_->GetJit(); |
| if (jit != nullptr) { |
| jit->GetCodeCache()->NotifyMethodRedefined(&method); |
| } |
| } |
| return true; |
| } |
| |
| bool Redefiner::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)); |
| } |
| } |
| return true; |
| } |
| |
| // Performs updates to class that will allow us to verify it. |
| bool Redefiner::UpdateClass(art::ObjPtr<art::mirror::Class> mclass, |
| art::ObjPtr<art::mirror::DexCache> new_dex_cache) { |
| const art::DexFile::ClassDef* class_def = art::OatFile::OatDexFile::FindClassDef( |
| *dex_file_, class_sig_, art::ComputeModifiedUtf8Hash(class_sig_)); |
| if (class_def == nullptr) { |
| RecordFailure(ERR(INVALID_CLASS_FORMAT), "Unable to find ClassDef!"); |
| return false; |
| } |
| if (!UpdateMethods(mclass, new_dex_cache, *class_def)) { |
| // TODO Investigate appropriate error types. |
| RecordFailure(ERR(INTERNAL), "Unable to update class methods."); |
| return false; |
| } |
| if (!UpdateFields(mclass)) { |
| // TODO Investigate appropriate error types. |
| RecordFailure(ERR(INTERNAL), "Unable to update class fields."); |
| return false; |
| } |
| |
| // 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_))); |
| return true; |
| } |
| |
| bool Redefiner::UpdateJavaDexFile(art::ObjPtr<art::mirror::Object> java_dex_file, |
| art::ObjPtr<art::mirror::LongArray> new_cookie, |
| /*out*/art::ObjPtr<art::mirror::LongArray>* original_cookie) { |
| art::ArtField* internal_cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField( |
| "mInternalCookie", "Ljava/lang/Object;"); |
| art::ArtField* cookie_field = java_dex_file->GetClass()->FindDeclaredInstanceField( |
| "mCookie", "Ljava/lang/Object;"); |
| CHECK(internal_cookie_field != nullptr); |
| art::ObjPtr<art::mirror::LongArray> orig_internal_cookie( |
| internal_cookie_field->GetObject(java_dex_file)->AsLongArray()); |
| art::ObjPtr<art::mirror::LongArray> orig_cookie( |
| cookie_field->GetObject(java_dex_file)->AsLongArray()); |
| internal_cookie_field->SetObject<false>(java_dex_file, new_cookie); |
| *original_cookie = orig_internal_cookie; |
| if (!orig_cookie.IsNull()) { |
| cookie_field->SetObject<false>(java_dex_file, new_cookie); |
| } |
| return true; |
| } |
| |
| // This function does all (java) allocations we need to do for the Class being redefined. |
| // TODO Change this name maybe? |
| bool Redefiner::EnsureClassAllocationsFinished() { |
| art::StackHandleScope<2> hs(self_); |
| art::Handle<art::mirror::Class> klass(hs.NewHandle(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(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. |
| self_->AssertPendingOOMException(); |
| 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(self_, ext); |
| if (!ext->ExtendObsoleteArrays( |
| self_, klass->GetDeclaredMethodsSlice(art::kRuntimePointerSize).size())) { |
| // OOM. Clear exception and return error. |
| self_->AssertPendingOOMException(); |
| self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate/extend obsolete methods map"); |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| } // namespace openjdkjvmti |
