| /* 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 <stddef.h> |
| #include <sys/types.h> |
| |
| #include <unordered_map> |
| #include <unordered_set> |
| |
| #include "transform.h" |
| |
| #include "art_method.h" |
| #include "base/array_ref.h" |
| #include "base/globals.h" |
| #include "base/mem_map.h" |
| #include "class_linker.h" |
| #include "dex/dex_file.h" |
| #include "dex/dex_file_types.h" |
| #include "dex/utf.h" |
| #include "events-inl.h" |
| #include "fault_handler.h" |
| #include "gc_root-inl.h" |
| #include "jni_env_ext-inl.h" |
| #include "jvalue.h" |
| #include "jvmti.h" |
| #include "linear_alloc.h" |
| #include "mirror/array.h" |
| #include "mirror/class-inl.h" |
| #include "mirror/class_ext.h" |
| #include "mirror/class_loader-inl.h" |
| #include "mirror/string-inl.h" |
| #include "oat_file.h" |
| #include "scoped_thread_state_change-inl.h" |
| #include "stack.h" |
| #include "thread_list.h" |
| #include "ti_redefine.h" |
| #include "transform.h" |
| #include "utils/dex_cache_arrays_layout-inl.h" |
| |
| namespace openjdkjvmti { |
| |
| // A FaultHandler that will deal with initializing ClassDefinitions when they are actually needed. |
| class TransformationFaultHandler FINAL : public art::FaultHandler { |
| public: |
| explicit TransformationFaultHandler(art::FaultManager* manager) |
| : art::FaultHandler(manager), |
| uninitialized_class_definitions_lock_("JVMTI Initialized class definitions lock", |
| art::LockLevel::kSignalHandlingLock), |
| class_definition_initialized_cond_("JVMTI Initialized class definitions condition", |
| uninitialized_class_definitions_lock_) { |
| manager->AddHandler(this, /* generated_code */ false); |
| } |
| |
| ~TransformationFaultHandler() { |
| art::MutexLock mu(art::Thread::Current(), uninitialized_class_definitions_lock_); |
| uninitialized_class_definitions_.clear(); |
| } |
| |
| bool Action(int sig, siginfo_t* siginfo, void* context ATTRIBUTE_UNUSED) OVERRIDE { |
| DCHECK_EQ(sig, SIGSEGV); |
| art::Thread* self = art::Thread::Current(); |
| if (UNLIKELY(uninitialized_class_definitions_lock_.IsExclusiveHeld(self))) { |
| if (self != nullptr) { |
| LOG(FATAL) << "Recursive call into Transformation fault handler!"; |
| UNREACHABLE(); |
| } else { |
| LOG(ERROR) << "Possible deadlock due to recursive signal delivery of segv."; |
| } |
| } |
| uintptr_t ptr = reinterpret_cast<uintptr_t>(siginfo->si_addr); |
| ArtClassDefinition* res = nullptr; |
| |
| { |
| // NB Technically using a mutex and condition variables here is non-posix compliant but |
| // everything should be fine since both glibc and bionic implementations of mutexs and |
| // condition variables work fine so long as the thread was not interrupted during a |
| // lock/unlock (which it wasn't) on all architectures we care about. |
| art::MutexLock mu(self, uninitialized_class_definitions_lock_); |
| auto it = std::find_if(uninitialized_class_definitions_.begin(), |
| uninitialized_class_definitions_.end(), |
| [&](const auto op) { return op->ContainsAddress(ptr); }); |
| if (it != uninitialized_class_definitions_.end()) { |
| res = *it; |
| // Remove the class definition. |
| uninitialized_class_definitions_.erase(it); |
| // Put it in the initializing list |
| initializing_class_definitions_.push_back(res); |
| } else { |
| // Wait for the ptr to be initialized (if it is currently initializing). |
| while (DefinitionIsInitializing(ptr)) { |
| WaitForClassInitializationToFinish(); |
| } |
| // Return true (continue with user code) if we find that the definition has been |
| // initialized. Return false (continue on to next signal handler) if the definition is not |
| // initialized or found. |
| return std::find_if(initialized_class_definitions_.begin(), |
| initialized_class_definitions_.end(), |
| [&](const auto op) { return op->ContainsAddress(ptr); }) != |
| initialized_class_definitions_.end(); |
| } |
| } |
| |
| if (LIKELY(self != nullptr)) { |
| CHECK_EQ(self->GetState(), art::ThreadState::kNative) |
| << "Transformation fault handler occurred outside of native mode"; |
| } |
| |
| VLOG(signals) << "Lazy initialization of dex file for transformation of " << res->GetName() |
| << " during SEGV"; |
| res->InitializeMemory(); |
| |
| { |
| art::MutexLock mu(self, uninitialized_class_definitions_lock_); |
| // Move to initialized state and notify waiters. |
| initializing_class_definitions_.erase(std::find(initializing_class_definitions_.begin(), |
| initializing_class_definitions_.end(), |
| res)); |
| initialized_class_definitions_.push_back(res); |
| class_definition_initialized_cond_.Broadcast(self); |
| } |
| |
| return true; |
| } |
| |
| void RemoveDefinition(ArtClassDefinition* def) REQUIRES(!uninitialized_class_definitions_lock_) { |
| art::MutexLock mu(art::Thread::Current(), uninitialized_class_definitions_lock_); |
| auto it = std::find(uninitialized_class_definitions_.begin(), |
| uninitialized_class_definitions_.end(), |
| def); |
| if (it != uninitialized_class_definitions_.end()) { |
| uninitialized_class_definitions_.erase(it); |
| return; |
| } |
| while (std::find(initializing_class_definitions_.begin(), |
| initializing_class_definitions_.end(), |
| def) != initializing_class_definitions_.end()) { |
| WaitForClassInitializationToFinish(); |
| } |
| it = std::find(initialized_class_definitions_.begin(), |
| initialized_class_definitions_.end(), |
| def); |
| CHECK(it != initialized_class_definitions_.end()) << "Could not find class definition for " |
| << def->GetName(); |
| initialized_class_definitions_.erase(it); |
| } |
| |
| void AddArtDefinition(ArtClassDefinition* def) REQUIRES(!uninitialized_class_definitions_lock_) { |
| DCHECK(def->IsLazyDefinition()); |
| art::MutexLock mu(art::Thread::Current(), uninitialized_class_definitions_lock_); |
| uninitialized_class_definitions_.push_back(def); |
| } |
| |
| private: |
| bool DefinitionIsInitializing(uintptr_t ptr) REQUIRES(uninitialized_class_definitions_lock_) { |
| return std::find_if(initializing_class_definitions_.begin(), |
| initializing_class_definitions_.end(), |
| [&](const auto op) { return op->ContainsAddress(ptr); }) != |
| initializing_class_definitions_.end(); |
| } |
| |
| void WaitForClassInitializationToFinish() REQUIRES(uninitialized_class_definitions_lock_) { |
| class_definition_initialized_cond_.Wait(art::Thread::Current()); |
| } |
| |
| art::Mutex uninitialized_class_definitions_lock_ ACQUIRED_BEFORE(art::Locks::abort_lock_); |
| art::ConditionVariable class_definition_initialized_cond_ |
| GUARDED_BY(uninitialized_class_definitions_lock_); |
| |
| // A list of the class definitions that have a non-readable map. |
| std::vector<ArtClassDefinition*> uninitialized_class_definitions_ |
| GUARDED_BY(uninitialized_class_definitions_lock_); |
| |
| // A list of class definitions that are currently undergoing unquickening. Threads should wait |
| // until the definition is no longer in this before returning. |
| std::vector<ArtClassDefinition*> initializing_class_definitions_ |
| GUARDED_BY(uninitialized_class_definitions_lock_); |
| |
| // A list of class definitions that are already unquickened. Threads should immediately return if |
| // it is here. |
| std::vector<ArtClassDefinition*> initialized_class_definitions_ |
| GUARDED_BY(uninitialized_class_definitions_lock_); |
| }; |
| |
| static TransformationFaultHandler* gTransformFaultHandler = nullptr; |
| |
| void Transformer::Setup() { |
| // Although we create this the fault handler is actually owned by the 'art::fault_manager' which |
| // will take care of destroying it. |
| if (art::MemMap::kCanReplaceMapping && ArtClassDefinition::kEnableOnDemandDexDequicken) { |
| gTransformFaultHandler = new TransformationFaultHandler(&art::fault_manager); |
| } |
| } |
| |
| // Simple helper to add and remove the class definition from the fault handler. |
| class ScopedDefinitionHandler { |
| public: |
| explicit ScopedDefinitionHandler(ArtClassDefinition* def) |
| : def_(def), is_lazy_(def_->IsLazyDefinition()) { |
| if (is_lazy_) { |
| gTransformFaultHandler->AddArtDefinition(def_); |
| } |
| } |
| |
| ~ScopedDefinitionHandler() { |
| if (is_lazy_) { |
| gTransformFaultHandler->RemoveDefinition(def_); |
| } |
| } |
| |
| private: |
| ArtClassDefinition* def_; |
| bool is_lazy_; |
| }; |
| |
| // Initialize templates. |
| template |
| void Transformer::TransformSingleClassDirect<ArtJvmtiEvent::kClassFileLoadHookNonRetransformable>( |
| EventHandler* event_handler, art::Thread* self, /*in-out*/ArtClassDefinition* def); |
| template |
| void Transformer::TransformSingleClassDirect<ArtJvmtiEvent::kClassFileLoadHookRetransformable>( |
| EventHandler* event_handler, art::Thread* self, /*in-out*/ArtClassDefinition* def); |
| |
| template<ArtJvmtiEvent kEvent> |
| void Transformer::TransformSingleClassDirect(EventHandler* event_handler, |
| art::Thread* self, |
| /*in-out*/ArtClassDefinition* def) { |
| static_assert(kEvent == ArtJvmtiEvent::kClassFileLoadHookNonRetransformable || |
| kEvent == ArtJvmtiEvent::kClassFileLoadHookRetransformable, |
| "bad event type"); |
| // We don't want to do transitions between calling the event and setting the new data so change to |
| // native state early. This also avoids any problems that the FaultHandler might have in |
| // determining if an access to the dex_data is from generated code or not. |
| art::ScopedThreadStateChange stsc(self, art::ThreadState::kNative); |
| ScopedDefinitionHandler handler(def); |
| jint new_len = -1; |
| unsigned char* new_data = nullptr; |
| art::ArrayRef<const unsigned char> dex_data = def->GetDexData(); |
| event_handler->DispatchEvent<kEvent>( |
| self, |
| static_cast<JNIEnv*>(self->GetJniEnv()), |
| def->GetClass(), |
| def->GetLoader(), |
| def->GetName().c_str(), |
| def->GetProtectionDomain(), |
| static_cast<jint>(dex_data.size()), |
| dex_data.data(), |
| /*out*/&new_len, |
| /*out*/&new_data); |
| def->SetNewDexData(new_len, new_data); |
| } |
| |
| jvmtiError Transformer::RetransformClassesDirect( |
| EventHandler* event_handler, |
| art::Thread* self, |
| /*in-out*/std::vector<ArtClassDefinition>* definitions) { |
| for (ArtClassDefinition& def : *definitions) { |
| TransformSingleClassDirect<ArtJvmtiEvent::kClassFileLoadHookRetransformable>(event_handler, |
| self, |
| &def); |
| } |
| return OK; |
| } |
| |
| jvmtiError Transformer::RetransformClasses(ArtJvmTiEnv* env, |
| EventHandler* event_handler, |
| art::Runtime* runtime, |
| art::Thread* self, |
| jint class_count, |
| const jclass* classes, |
| /*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 (classes == nullptr) { |
| *error_msg = "null classes!"; |
| return ERR(NULL_POINTER); |
| } |
| // A holder that will Deallocate all the class bytes buffers on destruction. |
| std::vector<ArtClassDefinition> definitions; |
| jvmtiError res = OK; |
| for (jint i = 0; i < class_count; i++) { |
| res = Redefiner::GetClassRedefinitionError(classes[i], error_msg); |
| if (res != OK) { |
| return res; |
| } |
| ArtClassDefinition def; |
| res = def.Init(self, classes[i]); |
| if (res != OK) { |
| return res; |
| } |
| definitions.push_back(std::move(def)); |
| } |
| res = RetransformClassesDirect(event_handler, self, &definitions); |
| if (res != OK) { |
| return res; |
| } |
| return Redefiner::RedefineClassesDirect(env, runtime, self, definitions, error_msg); |
| } |
| |
| // TODO Move this somewhere else, ti_class? |
| jvmtiError GetClassLocation(ArtJvmTiEnv* env, jclass klass, /*out*/std::string* location) { |
| JNIEnv* jni_env = nullptr; |
| jint ret = env->art_vm->GetEnv(reinterpret_cast<void**>(&jni_env), JNI_VERSION_1_1); |
| if (ret != JNI_OK) { |
| // TODO Different error might be better? |
| return ERR(INTERNAL); |
| } |
| art::ScopedObjectAccess soa(jni_env); |
| art::StackHandleScope<1> hs(art::Thread::Current()); |
| art::Handle<art::mirror::Class> hs_klass(hs.NewHandle(soa.Decode<art::mirror::Class>(klass))); |
| const art::DexFile& dex = hs_klass->GetDexFile(); |
| *location = dex.GetLocation(); |
| return OK; |
| } |
| |
| } // namespace openjdkjvmti |