| /* 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 <algorithm> |
| #include <atomic> |
| #include <iterator> |
| #include <limits> |
| #include <sstream> |
| #include <string_view> |
| #include <unordered_map> |
| |
| #include <android-base/logging.h> |
| #include <android-base/stringprintf.h> |
| |
| #include "android-base/thread_annotations.h" |
| #include "art_field-inl.h" |
| #include "art_field.h" |
| #include "art_jvmti.h" |
| #include "art_method-inl.h" |
| #include "art_method.h" |
| #include "base/array_ref.h" |
| #include "base/casts.h" |
| #include "base/enums.h" |
| #include "base/globals.h" |
| #include "base/length_prefixed_array.h" |
| #include "base/utils.h" |
| #include "class_linker-inl.h" |
| #include "class_linker.h" |
| #include "class_root.h" |
| #include "class_status.h" |
| #include "debugger.h" |
| #include "dex/art_dex_file_loader.h" |
| #include "dex/class_accessor-inl.h" |
| #include "dex/class_accessor.h" |
| #include "dex/dex_file.h" |
| #include "dex/dex_file_loader.h" |
| #include "dex/dex_file_types.h" |
| #include "dex/primitive.h" |
| #include "dex/signature-inl.h" |
| #include "dex/signature.h" |
| #include "events-inl.h" |
| #include "events.h" |
| #include "gc/allocation_listener.h" |
| #include "gc/heap.h" |
| #include "gc/heap-inl.h" |
| #include "gc/heap-visit-objects-inl.h" |
| #include "handle.h" |
| #include "handle_scope.h" |
| #include "instrumentation.h" |
| #include "intern_table.h" |
| #include "jdwp/jdwp.h" |
| #include "jdwp/jdwp_constants.h" |
| #include "jdwp/jdwp_event.h" |
| #include "jdwp/object_registry.h" |
| #include "jit/jit.h" |
| #include "jit/jit_code_cache.h" |
| #include "jni/jni_env_ext-inl.h" |
| #include "jni/jni_id_manager.h" |
| #include "jvmti.h" |
| #include "jvmti_allocator.h" |
| #include "linear_alloc.h" |
| #include "mirror/array-alloc-inl.h" |
| #include "mirror/array.h" |
| #include "mirror/class-alloc-inl.h" |
| #include "mirror/class-inl.h" |
| #include "mirror/class-refvisitor-inl.h" |
| #include "mirror/class.h" |
| #include "mirror/class_ext-inl.h" |
| #include "mirror/dex_cache-inl.h" |
| #include "mirror/dex_cache.h" |
| #include "mirror/executable-inl.h" |
| #include "mirror/field-inl.h" |
| #include "mirror/method.h" |
| #include "mirror/method_handle_impl-inl.h" |
| #include "mirror/object.h" |
| #include "mirror/object_array-alloc-inl.h" |
| #include "mirror/object_array-inl.h" |
| #include "mirror/object_array.h" |
| #include "mirror/string.h" |
| #include "mirror/var_handle.h" |
| #include "nativehelper/scoped_local_ref.h" |
| #include "non_debuggable_classes.h" |
| #include "obj_ptr.h" |
| #include "object_lock.h" |
| #include "runtime.h" |
| #include "runtime_globals.h" |
| #include "stack.h" |
| #include "thread.h" |
| #include "thread_list.h" |
| #include "ti_breakpoint.h" |
| #include "ti_class_definition.h" |
| #include "ti_class_loader.h" |
| #include "ti_heap.h" |
| #include "ti_logging.h" |
| #include "ti_thread.h" |
| #include "transform.h" |
| #include "verifier/class_verifier.h" |
| #include "verifier/verifier_enums.h" |
| #include "well_known_classes.h" |
| #include "write_barrier.h" |
| |
| namespace openjdkjvmti { |
| |
| // Debug check to force us to directly check we saw all methods and fields exactly once directly. |
| // Normally we don't need to do this since if any are missing the count will be different |
| constexpr bool kCheckAllMethodsSeenOnce = art::kIsDebugBuild; |
| |
| using android::base::StringPrintf; |
| |
| // A helper that fills in a classes obsolete_methods_ and obsolete_dex_caches_ classExt fields as |
| // they are created. This ensures that we can always call any method of an obsolete ArtMethod object |
| // almost as soon as they are created since the GetObsoleteDexCache method will succeed. |
| class ObsoleteMap { |
| public: |
| art::ArtMethod* FindObsoleteVersion(art::ArtMethod* original) const |
| REQUIRES(art::Locks::mutator_lock_, art::Roles::uninterruptible_) { |
| auto method_pair = id_map_.find(original); |
| if (method_pair != id_map_.end()) { |
| art::ArtMethod* res = obsolete_methods_->GetElementPtrSize<art::ArtMethod*>( |
| method_pair->second, art::kRuntimePointerSize); |
| DCHECK(res != nullptr); |
| return res; |
| } else { |
| return nullptr; |
| } |
| } |
| |
| void RecordObsolete(art::ArtMethod* original, art::ArtMethod* obsolete) |
| REQUIRES(art::Locks::mutator_lock_, art::Roles::uninterruptible_) { |
| DCHECK(original != nullptr); |
| DCHECK(obsolete != nullptr); |
| int32_t slot = next_free_slot_++; |
| DCHECK_LT(slot, obsolete_methods_->GetLength()); |
| DCHECK(nullptr == |
| obsolete_methods_->GetElementPtrSize<art::ArtMethod*>(slot, art::kRuntimePointerSize)); |
| DCHECK(nullptr == obsolete_dex_caches_->Get(slot)); |
| obsolete_methods_->SetElementPtrSize(slot, obsolete, art::kRuntimePointerSize); |
| obsolete_dex_caches_->Set(slot, original_dex_cache_); |
| id_map_.insert({original, slot}); |
| } |
| |
| ObsoleteMap(art::ObjPtr<art::mirror::PointerArray> obsolete_methods, |
| art::ObjPtr<art::mirror::ObjectArray<art::mirror::DexCache>> obsolete_dex_caches, |
| art::ObjPtr<art::mirror::DexCache> original_dex_cache) |
| : next_free_slot_(0), |
| obsolete_methods_(obsolete_methods), |
| obsolete_dex_caches_(obsolete_dex_caches), |
| original_dex_cache_(original_dex_cache) { |
| // Figure out where the first unused slot in the obsolete_methods_ array is. |
| while (obsolete_methods_->GetElementPtrSize<art::ArtMethod*>( |
| next_free_slot_, art::kRuntimePointerSize) != nullptr) { |
| DCHECK(obsolete_dex_caches_->Get(next_free_slot_) != nullptr); |
| next_free_slot_++; |
| } |
| // Sanity check that the same slot in obsolete_dex_caches_ is free. |
| DCHECK(obsolete_dex_caches_->Get(next_free_slot_) == nullptr); |
| } |
| |
| struct ObsoleteMethodPair { |
| art::ArtMethod* old_method; |
| art::ArtMethod* obsolete_method; |
| }; |
| |
| class ObsoleteMapIter { |
| public: |
| using iterator_category = std::forward_iterator_tag; |
| using value_type = ObsoleteMethodPair; |
| using difference_type = ptrdiff_t; |
| using pointer = void; // Unsupported. |
| using reference = void; // Unsupported. |
| |
| ObsoleteMethodPair operator*() const |
| REQUIRES(art::Locks::mutator_lock_, art::Roles::uninterruptible_) { |
| art::ArtMethod* obsolete = map_->obsolete_methods_->GetElementPtrSize<art::ArtMethod*>( |
| iter_->second, art::kRuntimePointerSize); |
| DCHECK(obsolete != nullptr); |
| return { iter_->first, obsolete }; |
| } |
| |
| bool operator==(ObsoleteMapIter other) const { |
| return map_ == other.map_ && iter_ == other.iter_; |
| } |
| |
| bool operator!=(ObsoleteMapIter other) const { |
| return !(*this == other); |
| } |
| |
| ObsoleteMapIter operator++(int) { |
| ObsoleteMapIter retval = *this; |
| ++(*this); |
| return retval; |
| } |
| |
| ObsoleteMapIter operator++() { |
| ++iter_; |
| return *this; |
| } |
| |
| private: |
| ObsoleteMapIter(const ObsoleteMap* map, |
| std::unordered_map<art::ArtMethod*, int32_t>::const_iterator iter) |
| : map_(map), iter_(iter) {} |
| |
| const ObsoleteMap* map_; |
| std::unordered_map<art::ArtMethod*, int32_t>::const_iterator iter_; |
| |
| friend class ObsoleteMap; |
| }; |
| |
| ObsoleteMapIter end() const { |
| return ObsoleteMapIter(this, id_map_.cend()); |
| } |
| |
| ObsoleteMapIter begin() const { |
| return ObsoleteMapIter(this, id_map_.cbegin()); |
| } |
| |
| private: |
| int32_t next_free_slot_; |
| std::unordered_map<art::ArtMethod*, int32_t> id_map_; |
| // Pointers to the fields in mirror::ClassExt. These can be held as ObjPtr since this is only used |
| // when we have an exclusive mutator_lock_ (i.e. all threads are suspended). |
| art::ObjPtr<art::mirror::PointerArray> obsolete_methods_; |
| art::ObjPtr<art::mirror::ObjectArray<art::mirror::DexCache>> obsolete_dex_caches_; |
| art::ObjPtr<art::mirror::DexCache> original_dex_cache_; |
| }; |
| |
| // 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, |
| ObsoleteMap* 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, |
| ObsoleteMap* 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::ScopedAssertNoThreadSuspension snts("Fixing up the stack for obsolete methods."); |
| 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: " |
| << old_method->PrettyMethod() << " is inlined into " |
| << GetOuterMethod()->PrettyMethod(); |
| art::ArtMethod* new_obsolete_method = obsolete_maps_->FindObsoleteVersion(old_method); |
| if (new_obsolete_method == nullptr) { |
| // 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(art::Thread::Current(), 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(); |
| cl->SetEntryPointsForObsoleteMethod(new_obsolete_method); |
| obsolete_maps_->RecordObsolete(old_method, new_obsolete_method); |
| } |
| 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 are added to the obsolete_methods_ (and obsolete_dex_caches_) fields of |
| // the redefined classes ClassExt as it is filled. |
| ObsoleteMap* obsolete_maps_; |
| }; |
| |
| template <RedefinitionType kType> |
| jvmtiError |
| Redefiner::IsModifiableClassGeneric(jvmtiEnv* env, jclass klass, jboolean* is_redefinable) { |
| if (env == nullptr) { |
| return ERR(INVALID_ENVIRONMENT); |
| } |
| 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() || !obj->IsClass()) { |
| return ERR(INVALID_CLASS); |
| } |
| art::Handle<art::mirror::Class> h_klass(hs.NewHandle(obj->AsClass())); |
| std::string err_unused; |
| *is_redefinable = |
| Redefiner::GetClassRedefinitionError<kType>(h_klass, &err_unused) != ERR(UNMODIFIABLE_CLASS) |
| ? JNI_TRUE |
| : JNI_FALSE; |
| return OK; |
| } |
| |
| jvmtiError |
| Redefiner::IsStructurallyModifiableClass(jvmtiEnv* env, jclass klass, jboolean* is_redefinable) { |
| return Redefiner::IsModifiableClassGeneric<RedefinitionType::kStructural>( |
| env, klass, is_redefinable); |
| } |
| |
| jvmtiError Redefiner::IsModifiableClass(jvmtiEnv* env, jclass klass, jboolean* is_redefinable) { |
| return Redefiner::IsModifiableClassGeneric<RedefinitionType::kNormal>(env, klass, is_redefinable); |
| } |
| |
| template <RedefinitionType kType> |
| jvmtiError Redefiner::GetClassRedefinitionError(jclass klass, /*out*/ std::string* error_msg) { |
| 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() || !obj->IsClass()) { |
| return ERR(INVALID_CLASS); |
| } |
| art::Handle<art::mirror::Class> h_klass(hs.NewHandle(obj->AsClass())); |
| return Redefiner::GetClassRedefinitionError(h_klass, error_msg); |
| } |
| |
| template <RedefinitionType kType> |
| jvmtiError Redefiner::GetClassRedefinitionError(art::Handle<art::mirror::Class> klass, |
| /*out*/ std::string* error_msg) { |
| art::Thread* self = art::Thread::Current(); |
| if (!klass->IsResolved()) { |
| // It's only a problem to try to retransform/redefine a unprepared class if it's happening on |
| // the same thread as the class-linking process. If it's on another thread we will be able to |
| // wait for the preparation to finish and continue from there. |
| if (klass->GetLockOwnerThreadId() == self->GetThreadId()) { |
| *error_msg = "Modification of class " + klass->PrettyClass() + |
| " from within the classes ClassLoad callback is not supported to prevent deadlocks." + |
| " Please use ClassFileLoadHook directly instead."; |
| return ERR(INTERNAL); |
| } else { |
| LOG(WARNING) << klass->PrettyClass() << " is not yet resolved. Attempting to transform " |
| << "it could cause arbitrary length waits as the class is being resolved."; |
| } |
| } |
| 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->IsStringClass()) { |
| *error_msg = "Modification of String class is 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); |
| } |
| |
| for (jclass c : art::NonDebuggableClasses::GetNonDebuggableClasses()) { |
| if (klass.Get() == self->DecodeJObject(c)->AsClass()) { |
| *error_msg = "Class might have stack frames that cannot be made obsolete"; |
| return ERR(UNMODIFIABLE_CLASS); |
| } |
| } |
| |
| if (kType == RedefinitionType::kStructural) { |
| // Class initialization interacts really badly with structural redefinition since we need to |
| // make the old class obsolete. We currently just blanket don't allow it. |
| // TODO It might be nice to allow this at some point. |
| if (klass->IsInitializing() && |
| !klass->IsInitialized() && |
| klass->GetClinitThreadId() == self->GetTid()) { |
| // We are in the class-init running on this thread. |
| *error_msg = "Modification of class " + klass->PrettyClass() + " during class" + |
| " initialization is not allowed."; |
| return ERR(INTERNAL); |
| } |
| if (!art::Runtime::Current()->GetClassLinker()->EnsureInitialized( |
| self, klass, /*can_init_fields=*/true, /*can_init_parents=*/true)) { |
| self->AssertPendingException(); |
| *error_msg = "Class " + klass->PrettyClass() + " failed initialization. Structural" + |
| " redefinition of erroneous classes is not allowed. Failure was: " + |
| self->GetException()->Dump(); |
| self->ClearException(); |
| return ERR(INVALID_CLASS); |
| } |
| art::StackHandleScope<2> hs(self); |
| art::Handle<art::mirror::ObjectArray<art::mirror::Class>> roots( |
| hs.NewHandle(art::Runtime::Current()->GetClassLinker()->GetClassRoots())); |
| art::MutableHandle<art::mirror::Class> obj(hs.NewHandle<art::mirror::Class>(nullptr)); |
| for (int32_t i = 0; i < roots->GetLength(); i++) { |
| obj.Assign(roots->Get(i)); |
| // check if the redefined class is a superclass of any root (i.e. mirror plus a few other |
| // important types). |
| if (klass->IsAssignableFrom(obj.Get())) { |
| std::string pc(klass->PrettyClass()); |
| *error_msg = StringPrintf("Class %s is an important runtime class and cannot be " |
| "structurally redefined.", |
| pc.c_str()); |
| return ERR(UNMODIFIABLE_CLASS); |
| } |
| } |
| // Check Thread specifically since it's not a root but too many things reach into it with Unsafe |
| // too allow structural redefinition. |
| if (klass->IsAssignableFrom( |
| self->DecodeJObject(art::WellKnownClasses::java_lang_Thread)->AsClass())) { |
| *error_msg = |
| "java.lang.Thread has fields accessed using sun.misc.unsafe directly. It is not " |
| "safe to structurally redefine it."; |
| return ERR(UNMODIFIABLE_CLASS); |
| } |
| // Check for already existing non-static fields/methods. |
| // TODO Remove this once we support generic method/field addition. |
| bool non_static_method = false; |
| klass->VisitMethods([&](art::ArtMethod* m) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| // Since direct-methods (ie privates + <init> are not in any vtable/iftable we can update |
| // them). |
| if (!m->IsDirect()) { |
| non_static_method = true; |
| *error_msg = StringPrintf("%s has a non-direct function %s", |
| klass->PrettyClass().c_str(), |
| m->PrettyMethod().c_str()); |
| } |
| }, art::kRuntimePointerSize); |
| if (non_static_method) { |
| return ERR(UNMODIFIABLE_CLASS); |
| } |
| bool non_static_field = false; |
| klass->VisitFields([&](art::ArtField* f) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| if (!f->IsStatic()) { |
| non_static_field = true; |
| *error_msg = StringPrintf( |
| "%s has a non-static field %s", klass->PrettyClass().c_str(), f->PrettyField().c_str()); |
| } |
| }); |
| if (non_static_field) { |
| return ERR(UNMODIFIABLE_CLASS); |
| } |
| // Check for fields/methods which were returned before moving to index jni id type. |
| // TODO We might want to rework how this is done. Once full redefinition is implemented we will |
| // need to check any subtypes too. |
| art::ObjPtr<art::mirror::ClassExt> ext(klass->GetExtData()); |
| if (!ext.IsNull()) { |
| bool non_index_id = false; |
| ext->VisitJFieldIDs([&](jfieldID id, uint32_t idx, bool is_static) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| if (!art::jni::JniIdManager::IsIndexId(id)) { |
| non_index_id = true; |
| *error_msg = |
| StringPrintf("%s Field %d (%s) has non-index jni-ids.", |
| (is_static ? "static" : "non-static"), |
| idx, |
| (is_static ? klass->GetStaticField(idx) |
| : klass->GetInstanceField(idx))->PrettyField().c_str()); |
| } |
| }); |
| ext->VisitJMethodIDs([&](jmethodID id, uint32_t idx) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| if (!art::jni::JniIdManager::IsIndexId(id)) { |
| non_index_id = true; |
| *error_msg = StringPrintf( |
| "method %d (%s) has non-index jni-ids.", |
| idx, |
| klass->GetDeclaredMethodsSlice(art::kRuntimePointerSize)[idx].PrettyMethod().c_str()); |
| } |
| }); |
| if (non_index_id) { |
| return ERR(UNMODIFIABLE_CLASS); |
| } |
| } |
| } |
| return OK; |
| } |
| |
| template jvmtiError Redefiner::GetClassRedefinitionError<RedefinitionType::kNormal>( |
| art::Handle<art::mirror::Class> klass, /*out*/ std::string* error_msg); |
| template jvmtiError Redefiner::GetClassRedefinitionError<RedefinitionType::kStructural>( |
| art::Handle<art::mirror::Class> klass, /*out*/ std::string* error_msg); |
| |
| // Moves dex data to an anonymous, read-only mmap'd region. |
| art::MemMap Redefiner::MoveDataToMemMap(const std::string& original_location, |
| art::ArrayRef<const unsigned char> data, |
| std::string* error_msg) { |
| art::MemMap map = art::MemMap::MapAnonymous( |
| StringPrintf("%s-transformed", original_location.c_str()).c_str(), |
| data.size(), |
| PROT_READ|PROT_WRITE, |
| /*low_4gb=*/ false, |
| error_msg); |
| if (LIKELY(map.IsValid())) { |
| memcpy(map.Begin(), data.data(), data.size()); |
| // 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::ArrayRef<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(jvmtiEnv* jenv, |
| jint class_count, |
| const jvmtiClassDefinition* definitions) { |
| art::Runtime* runtime = art::Runtime::Current(); |
| art::Thread* self = art::Thread::Current(); |
| ArtJvmTiEnv* env = ArtJvmTiEnv::AsArtJvmTiEnv(jenv); |
| if (env == nullptr) { |
| JVMTI_LOG(WARNING, env) << "FAILURE TO REDEFINE env was null!"; |
| return ERR(INVALID_ENVIRONMENT); |
| } else if (class_count < 0) { |
| JVMTI_LOG(WARNING, env) << "FAILURE TO REDEFINE 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) { |
| JVMTI_LOG(WARNING, env) << "FAILURE TO REDEFINE null definitions!"; |
| return ERR(NULL_POINTER); |
| } |
| std::string error_msg; |
| std::vector<ArtClassDefinition> def_vector; |
| def_vector.reserve(class_count); |
| for (jint i = 0; i < class_count; i++) { |
| jvmtiError res = Redefiner::GetClassRedefinitionError(definitions[i].klass, &error_msg); |
| if (res != OK) { |
| JVMTI_LOG(WARNING, env) << "FAILURE TO REDEFINE " << error_msg; |
| return res; |
| } |
| ArtClassDefinition def; |
| res = def.Init(self, definitions[i]); |
| if (res != OK) { |
| JVMTI_LOG(WARNING, env) << "FAILURE TO REDEFINE bad definition " << i; |
| return res; |
| } |
| def_vector.push_back(std::move(def)); |
| } |
| // Call all the transformation events. |
| Transformer::RetransformClassesDirect(self, &def_vector); |
| jvmtiError res = RedefineClassesDirect( |
| env, runtime, self, def_vector, RedefinitionType::kNormal, &error_msg); |
| if (res != OK) { |
| JVMTI_LOG(WARNING, env) << "FAILURE TO REDEFINE " << error_msg; |
| } |
| return res; |
| } |
| |
| jvmtiError Redefiner::StructurallyRedefineClassDirect(jvmtiEnv* env, |
| jclass klass, |
| const unsigned char* data, |
| jint data_size) { |
| if (env == nullptr) { |
| return ERR(INVALID_ENVIRONMENT); |
| } else if (ArtJvmTiEnv::AsArtJvmTiEnv(env)->capabilities.can_redefine_classes != 1) { |
| JVMTI_LOG(INFO, env) << "Does not have can_redefine_classes cap!"; |
| return ERR(MUST_POSSESS_CAPABILITY); |
| } |
| std::vector<ArtClassDefinition> acds; |
| ArtClassDefinition acd; |
| jvmtiError err = acd.Init( |
| art::Thread::Current(), |
| jvmtiClassDefinition{ .klass = klass, .class_byte_count = data_size, .class_bytes = data }); |
| if (err != OK) { |
| return err; |
| } |
| acds.push_back(std::move(acd)); |
| std::string err_msg; |
| err = RedefineClassesDirect(ArtJvmTiEnv::AsArtJvmTiEnv(env), |
| art::Runtime::Current(), |
| art::Thread::Current(), |
| acds, |
| RedefinitionType::kStructural, |
| &err_msg); |
| if (err != OK) { |
| JVMTI_LOG(WARNING, env) << "Failed structural redefinition: " << err_msg; |
| } |
| return err; |
| } |
| |
| jvmtiError Redefiner::RedefineClassesDirect(ArtJvmTiEnv* env, |
| art::Runtime* runtime, |
| art::Thread* self, |
| const std::vector<ArtClassDefinition>& definitions, |
| RedefinitionType type, |
| 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. |
| // TODO We should prevent user-code suspensions to make sure this isn't held for too long. |
| art::jit::ScopedJitSuspend suspend_jit; |
| // Get shared mutator lock so we can lock all the classes. |
| art::ScopedObjectAccess soa(self); |
| Redefiner r(env, runtime, self, type, error_msg); |
| for (const ArtClassDefinition& def : definitions) { |
| // Only try to transform classes that have been modified. |
| if (def.IsModified()) { |
| 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.GetClass(), &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.GetClass(), &signature_ptr, &generic_ptr_unused)) != OK) { |
| *error_msg_ = "Unable to get class signature!"; |
| return ret; |
| } |
| JvmtiUniquePtr<char> generic_unique_ptr(MakeJvmtiUniquePtr(env, generic_ptr_unused)); |
| JvmtiUniquePtr<char> signature_unique_ptr(MakeJvmtiUniquePtr(env, signature_ptr)); |
| art::MemMap map = MoveDataToMemMap(original_dex_location, def.GetDexData(), error_msg_); |
| std::ostringstream os; |
| if (!map.IsValid()) { |
| os << "Failed to create anonymous mmap for modified dex file of class " << def.GetName() |
| << "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); |
| } |
| std::string name = map.GetName(); |
| uint32_t checksum = reinterpret_cast<const art::DexFile::Header*>(map.Begin())->checksum_; |
| const art::ArtDexFileLoader dex_file_loader; |
| std::unique_ptr<const art::DexFile> dex_file(dex_file_loader.Open(name, |
| 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.GetName() << ": " << *error_msg_; |
| *error_msg_ = os.str(); |
| return ERR(INVALID_CLASS_FORMAT); |
| } |
| redefinitions_.push_back( |
| Redefiner::ClassRedefinition(this, |
| def.GetClass(), |
| dex_file.release(), |
| signature_ptr, |
| def.GetNewOriginalDexFile())); |
| return OK; |
| } |
| |
| art::ObjPtr<art::mirror::Class> Redefiner::ClassRedefinition::GetMirrorClass() { |
| return driver_->self_->DecodeJObject(klass_)->AsClass(); |
| } |
| |
| art::ObjPtr<art::mirror::ClassLoader> Redefiner::ClassRedefinition::GetClassLoader() { |
| return GetMirrorClass()->GetClassLoader(); |
| } |
| |
| art::mirror::DexCache* Redefiner::ClassRedefinition::CreateNewDexCache( |
| art::Handle<art::mirror::ClassLoader> loader) { |
| art::StackHandleScope<2> hs(driver_->self_); |
| art::ClassLinker* cl = driver_->runtime_->GetClassLinker(); |
| art::Handle<art::mirror::DexCache> cache(hs.NewHandle( |
| art::ObjPtr<art::mirror::DexCache>::DownCast( |
| art::GetClassRoot<art::mirror::DexCache>(cl)->AllocObject(driver_->self_)))); |
| if (cache.IsNull()) { |
| driver_->self_->AssertPendingOOMException(); |
| return nullptr; |
| } |
| art::Handle<art::mirror::String> location(hs.NewHandle( |
| cl->GetInternTable()->InternStrong(dex_file_->GetLocation().c_str()))); |
| if (location.IsNull()) { |
| driver_->self_->AssertPendingOOMException(); |
| return nullptr; |
| } |
| art::WriterMutexLock mu(driver_->self_, *art::Locks::dex_lock_); |
| art::mirror::DexCache::InitializeDexCache(driver_->self_, |
| cache.Get(), |
| location.Get(), |
| dex_file_.get(), |
| loader.IsNull() ? driver_->runtime_->GetLinearAlloc() |
| : loader->GetAllocator(), |
| art::kRuntimePointerSize); |
| return cache.Get(); |
| } |
| |
| 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::Object* Redefiner::ClassRedefinition::AllocateOrGetOriginalDexFile() { |
| // 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_.data()), |
| original_dex_file_.size()).Ptr(); |
| } |
| |
| // See if we already have one set. |
| art::ObjPtr<art::mirror::ClassExt> ext(GetMirrorClass()->GetExtData()); |
| if (!ext.IsNull()) { |
| art::ObjPtr<art::mirror::Object> old_original_dex_file(ext->GetOriginalDexFile()); |
| if (!old_original_dex_file.IsNull()) { |
| // We do. Use it. |
| return old_original_dex_file.Ptr(); |
| } |
| } |
| |
| // return the current dex_cache which has the dex file in it. |
| art::ObjPtr<art::mirror::DexCache> current_dex_cache(GetMirrorClass()->GetDexCache()); |
| // TODO Handle this or make it so it cannot happen. |
| if (current_dex_cache->GetDexFile()->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 current_dex_cache.Ptr(); |
| } |
| |
| struct CallbackCtx { |
| ObsoleteMap* obsolete_map; |
| art::LinearAlloc* allocator; |
| std::unordered_set<art::ArtMethod*> obsolete_methods; |
| |
| explicit CallbackCtx(ObsoleteMap* map, art::LinearAlloc* alloc) |
| : obsolete_map(map), 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::ObjPtr<art::mirror::Class> art_klass) { |
| DCHECK(!IsStructuralRedefinition()); |
| art::ScopedAssertNoThreadSuspension ns("No thread suspension during thread stack walking"); |
| art::ObjPtr<art::mirror::ClassExt> ext = art_klass->GetExtData(); |
| CHECK(ext->GetObsoleteMethods() != nullptr); |
| art::ClassLinker* linker = driver_->runtime_->GetClassLinker(); |
| // This holds pointers to the obsolete methods map fields which are updated as needed. |
| ObsoleteMap map(ext->GetObsoleteMethods(), ext->GetObsoleteDexCaches(), art_klass->GetDexCache()); |
| CallbackCtx ctx(&map, linker->GetAllocatorForClassLoader(art_klass->GetClassLoader())); |
| // Add all the declared methods to the map |
| for (auto& m : art_klass->GetDeclaredMethods(art::kRuntimePointerSize)) { |
| if (m.IsIntrinsic()) { |
| LOG(WARNING) << "Redefining intrinsic method " << m.PrettyMethod() << ". This may cause the " |
| << "unexpected use of the original definition of " << m.PrettyMethod() << "in " |
| << "methods that have already been compiled."; |
| } |
| // It is 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). Furthermore we would be unable to get some useful |
| // error checking from the interpreter which ensure we don't try to start executing obsolete |
| // methods. |
| ctx.obsolete_methods.insert(&m); |
| } |
| { |
| art::MutexLock mu(driver_->self_, *art::Locks::thread_list_lock_); |
| art::ThreadList* list = art::Runtime::Current()->GetThreadList(); |
| list->ForEach(DoAllocateObsoleteMethodsCallback, static_cast<void*>(&ctx)); |
| // After we've done walking all threads' stacks and updating method pointers on them, |
| // update JIT data structures (used by the stack walk above) to point to the new methods. |
| art::jit::Jit* jit = art::Runtime::Current()->GetJit(); |
| if (jit != nullptr) { |
| for (const ObsoleteMap::ObsoleteMethodPair& it : *ctx.obsolete_map) { |
| // 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(it.old_method, it.obsolete_method); |
| } |
| } |
| } |
| } |
| |
| namespace { |
| template <typename T> struct SignatureType {}; |
| template <> struct SignatureType<art::ArtField> { using type = std::string_view; }; |
| template <> struct SignatureType<art::ArtMethod> { using type = art::Signature; }; |
| |
| template <typename T> struct NameAndSignature { |
| public: |
| using SigType = typename SignatureType<T>::type; |
| |
| NameAndSignature(const art::DexFile* dex_file, uint32_t id); |
| |
| NameAndSignature(const std::string_view& name, const SigType& sig) : name_(name), sig_(sig) {} |
| |
| bool operator==(const NameAndSignature<T>& o) { |
| return name_ == o.name_ && sig_ == o.sig_; |
| } |
| |
| std::ostream& dump(std::ostream& os) const { |
| return os << "'" << name_ << "' (sig: " << sig_ << ")"; |
| } |
| |
| std::string ToString() const { |
| std::ostringstream os; |
| os << *this; |
| return os.str(); |
| } |
| |
| std::string_view name_; |
| SigType sig_; |
| }; |
| |
| template <typename T> |
| std::ostream& operator<<(std::ostream& os, const NameAndSignature<T>& nas) { |
| return nas.dump(os); |
| } |
| |
| using FieldNameAndSignature = NameAndSignature<art::ArtField>; |
| template <> |
| FieldNameAndSignature::NameAndSignature(const art::DexFile* dex_file, uint32_t id) |
| : FieldNameAndSignature(dex_file->GetFieldName(dex_file->GetFieldId(id)), |
| dex_file->GetFieldTypeDescriptor(dex_file->GetFieldId(id))) {} |
| |
| using MethodNameAndSignature = NameAndSignature<art::ArtMethod>; |
| template <> |
| MethodNameAndSignature::NameAndSignature(const art::DexFile* dex_file, uint32_t id) |
| : MethodNameAndSignature(dex_file->GetMethodName(dex_file->GetMethodId(id)), |
| dex_file->GetMethodSignature(dex_file->GetMethodId(id))) {} |
| |
| } // namespace |
| |
| void Redefiner::ClassRedefinition::RecordNewMethodAdded() { |
| DCHECK(driver_->IsStructuralRedefinition()); |
| added_methods_ = true; |
| } |
| void Redefiner::ClassRedefinition::RecordNewFieldAdded() { |
| DCHECK(driver_->IsStructuralRedefinition()); |
| added_fields_ = true; |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckMethods() { |
| art::StackHandleScope<1> hs(driver_->self_); |
| art::Handle<art::mirror::Class> h_klass(hs.NewHandle(GetMirrorClass())); |
| DCHECK_EQ(dex_file_->NumClassDefs(), 1u); |
| |
| // Make sure we have the same number of methods (or the same or greater if we're structural). |
| art::ClassAccessor accessor(*dex_file_, dex_file_->GetClassDef(0)); |
| uint32_t num_new_method = accessor.NumMethods(); |
| uint32_t num_old_method = h_klass->GetDeclaredMethodsSlice(art::kRuntimePointerSize).size(); |
| const bool is_structural = driver_->IsStructuralRedefinition(); |
| if (!is_structural && 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. |
| // 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. We should have already checked the fields. |
| const art::DexFile& old_dex_file = h_klass->GetDexFile(); |
| art::ClassAccessor old_accessor(old_dex_file, *h_klass->GetClassDef()); |
| // We need this to check for methods going missing in structural cases. |
| std::vector<bool> seen_old_methods( |
| (kCheckAllMethodsSeenOnce || is_structural) ? old_accessor.NumMethods() : 0, false); |
| const auto old_methods = old_accessor.GetMethods(); |
| for (const art::ClassAccessor::Method& new_method : accessor.GetMethods()) { |
| // Get the data on the method we are searching for |
| MethodNameAndSignature new_method_id(dex_file_.get(), new_method.GetIndex()); |
| const auto old_iter = |
| std::find_if(old_methods.cbegin(), old_methods.cend(), [&](const auto& current_old_method) { |
| MethodNameAndSignature old_method_id(&old_dex_file, current_old_method.GetIndex()); |
| return old_method_id == new_method_id; |
| }); |
| |
| if (old_iter == old_methods.cend()) { |
| // TODO Support adding non-static methods. |
| if (is_structural && new_method.IsStaticOrDirect()) { |
| RecordNewMethodAdded(); |
| } else { |
| RecordFailure( |
| ERR(UNSUPPORTED_REDEFINITION_METHOD_ADDED), |
| StringPrintf("Unknown virtual method %s was added!", new_method_id.ToString().c_str())); |
| return false; |
| } |
| } else if (new_method.GetAccessFlags() != old_iter->GetAccessFlags()) { |
| RecordFailure( |
| ERR(UNSUPPORTED_REDEFINITION_METHOD_MODIFIERS_CHANGED), |
| StringPrintf("method %s had different access flags", new_method_id.ToString().c_str())); |
| return false; |
| } else if (kCheckAllMethodsSeenOnce || is_structural) { |
| // We only need this if we are structural. |
| size_t off = std::distance(old_methods.cbegin(), old_iter); |
| DCHECK(!seen_old_methods[off]) |
| << "field at " << off << "(" |
| << MethodNameAndSignature(&old_dex_file, old_iter->GetIndex()) << ") already seen?"; |
| seen_old_methods[off] = true; |
| } |
| } |
| if ((kCheckAllMethodsSeenOnce || is_structural) && |
| !std::all_of(seen_old_methods.cbegin(), seen_old_methods.cend(), [](auto x) { return x; })) { |
| DCHECK(is_structural) << "We should have hit an earlier failure before getting here!"; |
| auto first_fail = |
| std::find_if(seen_old_methods.cbegin(), seen_old_methods.cend(), [](auto x) { return !x; }); |
| auto off = std::distance(seen_old_methods.cbegin(), first_fail); |
| auto fail = old_methods.cbegin(); |
| std::advance(fail, off); |
| RecordFailure( |
| ERR(UNSUPPORTED_REDEFINITION_METHOD_DELETED), |
| StringPrintf("Method %s missing!", |
| FieldNameAndSignature(&old_dex_file, fail->GetIndex()).ToString().c_str())); |
| return false; |
| } |
| return true; |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckFields() { |
| art::StackHandleScope<1> hs(driver_->self_); |
| art::Handle<art::mirror::Class> h_klass(hs.NewHandle(GetMirrorClass())); |
| DCHECK_EQ(dex_file_->NumClassDefs(), 1u); |
| art::ClassAccessor new_accessor(*dex_file_, dex_file_->GetClassDef(0)); |
| |
| const art::DexFile& old_dex_file = h_klass->GetDexFile(); |
| art::ClassAccessor old_accessor(old_dex_file, *h_klass->GetClassDef()); |
| // Instance and static fields can be differentiated by their flags so no need to check them |
| // separately. |
| std::vector<bool> seen_old_fields(old_accessor.NumFields(), false); |
| const auto old_fields = old_accessor.GetFields(); |
| for (const art::ClassAccessor::Field& new_field : new_accessor.GetFields()) { |
| // Get the data on the method we are searching for |
| FieldNameAndSignature new_field_id(dex_file_.get(), new_field.GetIndex()); |
| const auto old_iter = |
| std::find_if(old_fields.cbegin(), old_fields.cend(), [&](const auto& old_iter) { |
| FieldNameAndSignature old_field_id(&old_dex_file, old_iter.GetIndex()); |
| return old_field_id == new_field_id; |
| }); |
| if (old_iter == old_fields.cend()) { |
| // TODO Support adding non-static fields. |
| if (driver_->IsStructuralRedefinition() && new_field.IsStatic()) { |
| RecordNewFieldAdded(); |
| } else { |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED), |
| StringPrintf("Unknown field %s added!", new_field_id.ToString().c_str())); |
| return false; |
| } |
| } else if (new_field.GetAccessFlags() != old_iter->GetAccessFlags()) { |
| RecordFailure( |
| ERR(UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED), |
| StringPrintf("Field %s had different access flags", new_field_id.ToString().c_str())); |
| return false; |
| } else { |
| size_t off = std::distance(old_fields.cbegin(), old_iter); |
| DCHECK(!seen_old_fields[off]) |
| << "field at " << off << "(" << FieldNameAndSignature(&old_dex_file, old_iter->GetIndex()) |
| << ") already seen?"; |
| seen_old_fields[off] = true; |
| } |
| } |
| if (!std::all_of(seen_old_fields.cbegin(), seen_old_fields.cend(), [](auto x) { return x; })) { |
| auto first_fail = |
| std::find_if(seen_old_fields.cbegin(), seen_old_fields.cend(), [](auto x) { return !x; }); |
| auto off = std::distance(seen_old_fields.cbegin(), first_fail); |
| auto fail = old_fields.cbegin(); |
| std::advance(fail, off); |
| RecordFailure( |
| ERR(UNSUPPORTED_REDEFINITION_SCHEMA_CHANGED), |
| StringPrintf("Field %s is missing!", |
| FieldNameAndSignature(&old_dex_file, fail->GetIndex()).ToString().c_str())); |
| return false; |
| } |
| return true; |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckClass() { |
| 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::dex::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::dex::TypeList* interfaces = dex_file_->GetInterfacesList(def); |
| if (interfaces == nullptr) { |
| if (current_class->NumDirectInterfaces() != 0) { |
| // TODO Support this for kStructural. |
| RecordFailure(ERR(UNSUPPORTED_REDEFINITION_HIERARCHY_CHANGED), "Interfaces added"); |
| return false; |
| } |
| } else { |
| DCHECK(!current_class->IsProxyClass()); |
| const art::dex::TypeList* current_interfaces = current_class->GetInterfaceTypeList(); |
| if (current_interfaces == nullptr || current_interfaces->Size() != interfaces->Size()) { |
| // TODO Support this for kStructural. |
| 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; |
| } |
| } |
| } |
| return true; |
| } |
| |
| 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; |
| switch (driver_->type_) { |
| case RedefinitionType::kNormal: |
| res = Redefiner::GetClassRedefinitionError<RedefinitionType::kNormal>(h_klass, &err); |
| break; |
| case RedefinitionType::kStructural: |
| res = Redefiner::GetClassRedefinitionError<RedefinitionType::kStructural>(h_klass, &err); |
| break; |
| } |
| if (res != OK) { |
| RecordFailure(res, err); |
| return false; |
| } else { |
| return true; |
| } |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckRedefinitionIsValid() { |
| return CheckRedefinable() && CheckClass() && CheckFields() && CheckMethods(); |
| } |
| |
| class RedefinitionDataIter; |
| |
| // 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, |
| kSlotOldObsoleteMethods = 6, |
| kSlotOldDexCaches = 7, |
| kSlotNewClassObject = 8, |
| |
| // Must be last one. |
| kNumSlots = 9, |
| }; |
| |
| // 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, |
| std::vector<Redefiner::ClassRedefinition>* redefinitions) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) : |
| arr_(hs->NewHandle(art::mirror::ObjectArray<art::mirror::Object>::Alloc( |
| self, |
| art::GetClassRoot<art::mirror::ObjectArray<art::mirror::Object>>(runtime->GetClassLinker()), |
| redefinitions->size() * kNumSlots))), |
| redefinitions_(redefinitions) {} |
| |
| bool IsNull() const REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return arr_.IsNull(); |
| } |
| |
| art::ObjPtr<art::mirror::ClassLoader> GetSourceClassLoader(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::ObjPtr<art::mirror::ClassLoader>::DownCast( |
| GetSlot(klass_index, kSlotSourceClassLoader)); |
| } |
| art::ObjPtr<art::mirror::Object> GetJavaDexFile(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return GetSlot(klass_index, kSlotJavaDexFile); |
| } |
| art::ObjPtr<art::mirror::LongArray> GetNewDexFileCookie(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::ObjPtr<art::mirror::LongArray>::DownCast( |
| GetSlot(klass_index, kSlotNewDexFileCookie)); |
| } |
| art::ObjPtr<art::mirror::DexCache> GetNewDexCache(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::ObjPtr<art::mirror::DexCache>::DownCast(GetSlot(klass_index, kSlotNewDexCache)); |
| } |
| art::ObjPtr<art::mirror::Class> GetMirrorClass(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::ObjPtr<art::mirror::Class>::DownCast(GetSlot(klass_index, kSlotMirrorClass)); |
| } |
| |
| art::ObjPtr<art::mirror::Object> GetOriginalDexFile(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::ObjPtr<art::mirror::Object>::DownCast(GetSlot(klass_index, kSlotOrigDexFile)); |
| } |
| |
| art::ObjPtr<art::mirror::PointerArray> GetOldObsoleteMethods(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::ObjPtr<art::mirror::PointerArray>::DownCast( |
| GetSlot(klass_index, kSlotOldObsoleteMethods)); |
| } |
| |
| art::ObjPtr<art::mirror::ObjectArray<art::mirror::DexCache>> GetOldDexCaches( |
| jint klass_index) const REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::ObjPtr<art::mirror::ObjectArray<art::mirror::DexCache>>::DownCast( |
| GetSlot(klass_index, kSlotOldDexCaches)); |
| } |
| |
| art::ObjPtr<art::mirror::Class> GetNewClassObject(jint klass_index) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return art::ObjPtr<art::mirror::Class>::DownCast(GetSlot(klass_index, kSlotNewClassObject)); |
| } |
| |
| void SetSourceClassLoader(jint klass_index, art::ObjPtr<art::mirror::ClassLoader> loader) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotSourceClassLoader, loader); |
| } |
| void SetJavaDexFile(jint klass_index, art::ObjPtr<art::mirror::Object> dexfile) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotJavaDexFile, dexfile); |
| } |
| void SetNewDexFileCookie(jint klass_index, art::ObjPtr<art::mirror::LongArray> cookie) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotNewDexFileCookie, cookie); |
| } |
| void SetNewDexCache(jint klass_index, art::ObjPtr<art::mirror::DexCache> cache) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotNewDexCache, cache); |
| } |
| void SetMirrorClass(jint klass_index, art::ObjPtr<art::mirror::Class> klass) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotMirrorClass, klass); |
| } |
| void SetOriginalDexFile(jint klass_index, art::ObjPtr<art::mirror::Object> bytes) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotOrigDexFile, bytes); |
| } |
| void SetOldObsoleteMethods(jint klass_index, art::ObjPtr<art::mirror::PointerArray> methods) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotOldObsoleteMethods, methods); |
| } |
| void SetOldDexCaches(jint klass_index, |
| art::ObjPtr<art::mirror::ObjectArray<art::mirror::DexCache>> caches) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotOldDexCaches, caches); |
| } |
| |
| void SetNewClassObject(jint klass_index, art::ObjPtr<art::mirror::Class> klass) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| SetSlot(klass_index, kSlotNewClassObject, klass); |
| } |
| |
| int32_t Length() const REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return arr_->GetLength() / kNumSlots; |
| } |
| |
| std::vector<Redefiner::ClassRedefinition>* GetRedefinitions() |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return redefinitions_; |
| } |
| |
| bool operator==(const RedefinitionDataHolder& other) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return arr_.Get() == other.arr_.Get(); |
| } |
| |
| bool operator!=(const RedefinitionDataHolder& other) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return !(*this == other); |
| } |
| |
| RedefinitionDataIter begin() REQUIRES_SHARED(art::Locks::mutator_lock_); |
| RedefinitionDataIter end() REQUIRES_SHARED(art::Locks::mutator_lock_); |
| |
| private: |
| mutable art::Handle<art::mirror::ObjectArray<art::mirror::Object>> arr_; |
| std::vector<Redefiner::ClassRedefinition>* redefinitions_; |
| |
| art::ObjPtr<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); |
| }; |
| |
| class RedefinitionDataIter { |
| public: |
| RedefinitionDataIter(int32_t idx, RedefinitionDataHolder& holder) : idx_(idx), holder_(holder) {} |
| |
| RedefinitionDataIter(const RedefinitionDataIter&) = default; |
| RedefinitionDataIter(RedefinitionDataIter&&) = default; |
| RedefinitionDataIter& operator=(const RedefinitionDataIter&) = default; |
| RedefinitionDataIter& operator=(RedefinitionDataIter&&) = default; |
| |
| bool operator==(const RedefinitionDataIter& other) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return idx_ == other.idx_ && holder_ == other.holder_; |
| } |
| |
| bool operator!=(const RedefinitionDataIter& other) const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return !(*this == other); |
| } |
| |
| RedefinitionDataIter operator++() { // Value after modification. |
| idx_++; |
| return *this; |
| } |
| |
| RedefinitionDataIter operator++(int) { |
| RedefinitionDataIter temp = *this; |
| idx_++; |
| return temp; |
| } |
| |
| RedefinitionDataIter operator+(ssize_t delta) const { |
| RedefinitionDataIter temp = *this; |
| temp += delta; |
| return temp; |
| } |
| |
| RedefinitionDataIter& operator+=(ssize_t delta) { |
| idx_ += delta; |
| return *this; |
| } |
| |
| Redefiner::ClassRedefinition& GetRedefinition() REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return (*holder_.GetRedefinitions())[idx_]; |
| } |
| |
| RedefinitionDataHolder& GetHolder() { |
| return holder_; |
| } |
| |
| art::ObjPtr<art::mirror::ClassLoader> GetSourceClassLoader() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetSourceClassLoader(idx_); |
| } |
| art::ObjPtr<art::mirror::Object> GetJavaDexFile() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetJavaDexFile(idx_); |
| } |
| art::ObjPtr<art::mirror::LongArray> GetNewDexFileCookie() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetNewDexFileCookie(idx_); |
| } |
| art::ObjPtr<art::mirror::DexCache> GetNewDexCache() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetNewDexCache(idx_); |
| } |
| art::ObjPtr<art::mirror::Class> GetMirrorClass() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetMirrorClass(idx_); |
| } |
| art::ObjPtr<art::mirror::Object> GetOriginalDexFile() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetOriginalDexFile(idx_); |
| } |
| art::ObjPtr<art::mirror::PointerArray> GetOldObsoleteMethods() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetOldObsoleteMethods(idx_); |
| } |
| art::ObjPtr<art::mirror::ObjectArray<art::mirror::DexCache>> GetOldDexCaches() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetOldDexCaches(idx_); |
| } |
| |
| art::ObjPtr<art::mirror::Class> GetNewClassObject() const |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return holder_.GetNewClassObject(idx_); |
| } |
| |
| int32_t GetIndex() const { |
| return idx_; |
| } |
| |
| void SetSourceClassLoader(art::mirror::ClassLoader* loader) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetSourceClassLoader(idx_, loader); |
| } |
| void SetJavaDexFile(art::ObjPtr<art::mirror::Object> dexfile) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetJavaDexFile(idx_, dexfile); |
| } |
| void SetNewDexFileCookie(art::ObjPtr<art::mirror::LongArray> cookie) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetNewDexFileCookie(idx_, cookie); |
| } |
| void SetNewDexCache(art::ObjPtr<art::mirror::DexCache> cache) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetNewDexCache(idx_, cache); |
| } |
| void SetMirrorClass(art::ObjPtr<art::mirror::Class> klass) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetMirrorClass(idx_, klass); |
| } |
| void SetOriginalDexFile(art::ObjPtr<art::mirror::Object> bytes) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetOriginalDexFile(idx_, bytes); |
| } |
| void SetOldObsoleteMethods(art::ObjPtr<art::mirror::PointerArray> methods) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetOldObsoleteMethods(idx_, methods); |
| } |
| void SetOldDexCaches(art::ObjPtr<art::mirror::ObjectArray<art::mirror::DexCache>> caches) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetOldDexCaches(idx_, caches); |
| } |
| void SetNewClassObject(art::ObjPtr<art::mirror::Class> klass) |
| REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| holder_.SetNewClassObject(idx_, klass); |
| } |
| |
| private: |
| int32_t idx_; |
| RedefinitionDataHolder& holder_; |
| }; |
| |
| RedefinitionDataIter RedefinitionDataHolder::begin() { |
| return RedefinitionDataIter(0, *this); |
| } |
| |
| RedefinitionDataIter RedefinitionDataHolder::end() { |
| return RedefinitionDataIter(Length(), *this); |
| } |
| |
| bool Redefiner::ClassRedefinition::CheckVerification(const RedefinitionDataIter& iter) { |
| DCHECK_EQ(dex_file_->NumClassDefs(), 1u); |
| art::StackHandleScope<2> hs(driver_->self_); |
| std::string error; |
| // TODO Make verification log level lower |
| art::verifier::FailureKind failure = |
| art::verifier::ClassVerifier::VerifyClass(driver_->self_, |
| dex_file_.get(), |
| hs.NewHandle(iter.GetNewDexCache()), |
| hs.NewHandle(GetClassLoader()), |
| /*class_def=*/ dex_file_->GetClassDef(0), |
| /*callbacks=*/ nullptr, |
| /*allow_soft_failures=*/ true, |
| /*log_level=*/ |
| art::verifier::HardFailLogMode::kLogWarning, |
| art::Runtime::Current()->GetTargetSdkVersion(), |
| &error); |
| switch (failure) { |
| case art::verifier::FailureKind::kNoFailure: |
| case art::verifier::FailureKind::kSoftFailure: |
| return true; |
| case art::verifier::FailureKind::kHardFailure: { |
| RecordFailure(ERR(FAILS_VERIFICATION), "Failed to verify class. Error was: " + error); |
| return false; |
| } |
| } |
| } |
| |
| // 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( |
| art::Handle<art::mirror::ClassLoader> source_class_loader, |
| art::Handle<art::mirror::Object> dex_file_obj, |
| /*out*/RedefinitionDataIter* cur_data) { |
| 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 (auto old_data = cur_data->GetHolder().begin(); old_data != *cur_data; ++old_data) { |
| if (old_data.GetSourceClassLoader() == 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(old_data.GetNewDexFileCookie()); |
| 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. |
| cur_data->SetNewDexFileCookie(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 (auto old_data = cur_data->GetHolder().begin(); old_data != *cur_data; ++old_data) { |
| // We will let the GC take care of the cookie we allocated for this one. |
| if (old_data.GetSourceClassLoader() == source_class_loader.Get()) { |
| old_data.SetNewDexFileCookie(new_cookie.Get()); |
| } |
| } |
| } |
| |
| return true; |
| } |
| |
| bool Redefiner::ClassRedefinition::FinishRemainingAllocations( |
| /*out*/RedefinitionDataIter* cur_data) { |
| art::ScopedObjectAccessUnchecked soa(driver_->self_); |
| art::StackHandleScope<4> hs(driver_->self_); |
| cur_data->SetMirrorClass(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())) { |
| cur_data->SetSourceClassLoader(loader.Get()); |
| art::Handle<art::mirror::Object> dex_file_obj(hs.NewHandle( |
| ClassLoaderHelper::FindSourceDexFileObject(driver_->self_, loader))); |
| cur_data->SetJavaDexFile(dex_file_obj.Get()); |
| if (dex_file_obj == nullptr) { |
| RecordFailure(ERR(INTERNAL), "Unable to find dex file!"); |
| return false; |
| } |
| // Allocate the new dex file cookie. |
| if (!AllocateAndRememberNewDexFileCookie(loader, dex_file_obj, cur_data)) { |
| driver_->self_->AssertPendingOOMException(); |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate dex file array for class loader"); |
| return false; |
| } |
| } |
| cur_data->SetNewDexCache(CreateNewDexCache(loader)); |
| if (cur_data->GetNewDexCache() == 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. |
| cur_data->SetOriginalDexFile(AllocateOrGetOriginalDexFile()); |
| if (cur_data->GetOriginalDexFile() == nullptr) { |
| driver_->self_->AssertPendingOOMException(); |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate array for original dex file"); |
| return false; |
| } |
| if (added_fields_ || added_methods_) { |
| art::Handle<art::mirror::Class> nc(hs.NewHandle( |
| AllocateNewClassObject(hs.NewHandle(cur_data->GetNewDexCache())))); |
| if (nc.IsNull()) { |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Unable to allocate new class object"); |
| return false; |
| } |
| |
| cur_data->SetNewClassObject(nc.Get()); |
| } |
| return true; |
| } |
| |
| uint32_t Redefiner::ClassRedefinition::GetNewClassSize(bool with_embedded_tables, |
| art::Handle<art::mirror::Class> old_klass) { |
| // TODO Once we can add methods this won't work any more. |
| uint32_t num_vtable_entries = old_klass->GetVTableLength(); |
| uint32_t num_8bit_static_fields = 0; |
| uint32_t num_16bit_static_fields = 0; |
| uint32_t num_32bit_static_fields = 0; |
| uint32_t num_64bit_static_fields = 0; |
| uint32_t num_ref_static_fields = 0; |
| art::ClassAccessor accessor(*dex_file_, dex_file_->GetClassDef(0)); |
| for (const art::ClassAccessor::Field& f : accessor.GetStaticFields()) { |
| std::string_view desc(dex_file_->GetFieldTypeDescriptor(dex_file_->GetFieldId(f.GetIndex()))); |
| if (desc[0] == 'L' || desc[0] == '[') { |
| num_ref_static_fields++; |
| } else if (desc == "Z" || desc == "B") { |
| num_8bit_static_fields++; |
| } else if (desc == "C" || desc == "S") { |
| num_16bit_static_fields++; |
| } else if (desc == "I" || desc == "F") { |
| num_32bit_static_fields++; |
| } else if (desc == "J" || desc == "D") { |
| num_64bit_static_fields++; |
| } else { |
| LOG(FATAL) << "Unknown type descriptor! " << desc; |
| } |
| } |
| |
| return art::mirror::Class::ComputeClassSize(with_embedded_tables, |
| with_embedded_tables ? num_vtable_entries : 0, |
| num_8bit_static_fields, |
| num_16bit_static_fields, |
| num_32bit_static_fields, |
| num_64bit_static_fields, |
| num_ref_static_fields, |
| art::kRuntimePointerSize); |
| } |
| |
| art::ObjPtr<art::mirror::Class> |
| Redefiner::ClassRedefinition::AllocateNewClassObject(art::Handle<art::mirror::DexCache> cache) { |
| // This is a stripped down DefineClass. We don't want to use DefineClass directly because it needs |
| // to perform a lot of extra steps to tell the ClassTable and the jit and everything about a new |
| // class. For now we will need to rely on our tests catching any issues caused by changes in how |
| // class_linker sets up classes. |
| // TODO Unify/move this into ClassLinker maybe. |
| art::StackHandleScope<5> hs(driver_->self_); |
| art::ClassLinker* linker = driver_->runtime_->GetClassLinker(); |
| art::Handle<art::mirror::Class> old_class(hs.NewHandle(GetMirrorClass())); |
| art::Handle<art::mirror::Class> new_class(hs.NewHandle(linker->AllocClass( |
| driver_->self_, GetNewClassSize(/*with_embedded_tables=*/false, old_class)))); |
| if (new_class.IsNull()) { |
| driver_->self_->AssertPendingOOMException(); |
| JVMTI_LOG(ERROR, driver_->env_) << "Unable to allocate new class object!"; |
| return nullptr; |
| } |
| new_class->SetDexCache(cache.Get()); |
| linker->SetupClass(*dex_file_, dex_file_->GetClassDef(0), new_class, old_class->GetClassLoader()); |
| |
| // Make sure we are ready for linking. The lock isn't really needed since this isn't visible to |
| // other threads but the linker expects it. |
| art::ObjectLock<art::mirror::Class> lock(driver_->self_, new_class); |
| new_class->SetClinitThreadId(driver_->self_->GetTid()); |
| // Make sure we have a valid empty iftable even if there are errors. |
| new_class->SetIfTable(art::GetClassRoot<art::mirror::Object>(linker)->GetIfTable()); |
| linker->LoadClass(driver_->self_, *dex_file_, dex_file_->GetClassDef(0), new_class); |
| // NB. We know the interfaces and supers didn't change! :) |
| art::MutableHandle<art::mirror::Class> linked_class(hs.NewHandle<art::mirror::Class>(nullptr)); |
| art::Handle<art::mirror::ObjectArray<art::mirror::Class>> proxy_ifaces( |
| hs.NewHandle<art::mirror::ObjectArray<art::mirror::Class>>(nullptr)); |
| // No changing hierarchy so everything is loaded. |
| new_class->SetSuperClass(old_class->GetSuperClass()); |
| art::mirror::Class::SetStatus(new_class, art::ClassStatus::kLoaded, nullptr); |
| if (!linker->LinkClass(driver_->self_, nullptr, new_class, proxy_ifaces, &linked_class)) { |
| JVMTI_LOG(ERROR, driver_->env_) |
| << "failed to link class due to " |
| << (driver_->self_->IsExceptionPending() ? driver_->self_->GetException()->Dump() |
| : " unknown"); |
| driver_->self_->ClearException(); |
| return nullptr; |
| } |
| // We will initialize it manually. |
| art::ObjectLock<art::mirror::Class> objlock(driver_->self_, linked_class); |
| // We already verified the class earlier. No need to do it again. |
| linked_class->SetVerificationAttempted(); |
| // Mark the class as initialized. |
| CHECK(old_class->IsInitialized()) |
| << "Attempting to redefine an uninitalized class " << old_class->PrettyClass() |
| << " status=" << old_class->GetStatus(); |
| linker->ForceClassInitialized(driver_->self_, linked_class); |
| // Make sure we have ext-data space for method & field ids. We won't know if we need them until |
| // it's too late to create them. |
| // TODO We might want to remove these arrays if they're not needed. |
| if (art::mirror::Class::GetOrCreateInstanceFieldIds(linked_class).IsNull() || |
| art::mirror::Class::GetOrCreateStaticFieldIds(linked_class).IsNull() || |
| art::mirror::Class::GetOrCreateMethodIds(linked_class).IsNull()) { |
| driver_->self_->AssertPendingOOMException(); |
| driver_->self_->ClearException(); |
| JVMTI_LOG(ERROR, driver_->env_) << "Unable to allocate jni-id arrays!"; |
| return nullptr; |
| } |
| // Finish setting up methods. |
| linked_class->VisitMethods([&](art::ArtMethod* m) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| linker->SetEntryPointsToInterpreter(m); |
| m->SetNotIntrinsic(); |
| DCHECK(m->IsCopied() || m->GetDeclaringClass() == linked_class.Get()) |
| << m->PrettyMethod() |
| << " m->GetDeclaringClass(): " << m->GetDeclaringClass()->PrettyClass() |
| << " != linked_class.Get(): " << linked_class->PrettyClass(); |
| }, art::kRuntimePointerSize); |
| if (art::kIsDebugBuild) { |
| linked_class->VisitFields([&](art::ArtField* f) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| DCHECK_EQ(f->GetDeclaringClass(), linked_class.Get()); |
| }); |
| } |
| return linked_class.Get(); |
| } |
| |
| void Redefiner::ClassRedefinition::UnregisterJvmtiBreakpoints() { |
| BreakpointUtil::RemoveBreakpointsInClass(driver_->env_, GetMirrorClass().Ptr()); |
| } |
| |
| void Redefiner::ClassRedefinition::UnregisterBreakpoints() { |
| if (LIKELY(!art::Dbg::IsDebuggerActive())) { |
| return; |
| } |
| art::JDWP::JdwpState* state = art::Dbg::GetJdwpState(); |
| if (state != nullptr) { |
| state->UnregisterLocationEventsOnClass(GetMirrorClass()); |
| } |
| } |
| |
| void Redefiner::UnregisterAllBreakpoints() { |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| redef.UnregisterBreakpoints(); |
| redef.UnregisterJvmtiBreakpoints(); |
| } |
| } |
| |
| bool Redefiner::CheckAllRedefinitionAreValid() { |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| if (!redef.CheckRedefinitionIsValid()) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| void Redefiner::RestoreObsoleteMethodMapsIfUnneeded(RedefinitionDataHolder& holder) { |
| for (RedefinitionDataIter data = holder.begin(); data != holder.end(); ++data) { |
| data.GetRedefinition().RestoreObsoleteMethodMapsIfUnneeded(&data); |
| } |
| } |
| |
| bool Redefiner::EnsureAllClassAllocationsFinished(RedefinitionDataHolder& holder) { |
| for (RedefinitionDataIter data = holder.begin(); data != holder.end(); ++data) { |
| if (!data.GetRedefinition().EnsureClassAllocationsFinished(&data)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| bool Redefiner::FinishAllRemainingAllocations(RedefinitionDataHolder& holder) { |
| for (RedefinitionDataIter data = holder.begin(); data != holder.end(); ++data) { |
| // Allocate the data this redefinition requires. |
| if (!data.GetRedefinition().FinishRemainingAllocations(&data)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| void Redefiner::ClassRedefinition::ReleaseDexFile() { |
| dex_file_.release(); // NOLINT b/117926937 |
| } |
| |
| void Redefiner::ReleaseAllDexFiles() { |
| for (Redefiner::ClassRedefinition& redef : redefinitions_) { |
| redef.ReleaseDexFile(); |
| } |
| } |
| |
| bool Redefiner::CheckAllClassesAreVerified(RedefinitionDataHolder& holder) { |
| for (RedefinitionDataIter data = holder.begin(); data != holder.end(); ++data) { |
| if (!data.GetRedefinition().CheckVerification(data)) { |
| return false; |
| } |
| } |
| return true; |
| } |
| |
| class ScopedDisableConcurrentAndMovingGc { |
| public: |
| ScopedDisableConcurrentAndMovingGc(art::gc::Heap* heap, art::Thread* self) |
| : heap_(heap), self_(self) { |
| if (heap_->IsGcConcurrentAndMoving()) { |
| heap_->IncrementDisableMovingGC(self_); |
| } |
| } |
| |
| ~ScopedDisableConcurrentAndMovingGc() { |
| if (heap_->IsGcConcurrentAndMoving()) { |
| heap_->DecrementDisableMovingGC(self_); |
| } |
| } |
| private: |
| art::gc::Heap* heap_; |
| art::Thread* self_; |
| }; |
| |
| 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_); |
| 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(holder) || |
| !FinishAllRemainingAllocations(holder) || |
| !CheckAllClassesAreVerified(holder)) { |
| return result_; |
| } |
| |
| // At this point we can no longer fail without corrupting the runtime state. |
| for (RedefinitionDataIter data = holder.begin(); data != holder.end(); ++data) { |
| art::ClassLinker* cl = runtime_->GetClassLinker(); |
| cl->RegisterExistingDexCache(data.GetNewDexCache(), data.GetSourceClassLoader()); |
| if (data.GetSourceClassLoader() == nullptr) { |
| cl->AppendToBootClassPath(self_, data.GetRedefinition().GetDexFile()); |
| } |
| } |
| UnregisterAllBreakpoints(); |
| |
| // 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. |
| ScopedDisableConcurrentAndMovingGc sdcamgc(runtime_->GetHeap(), 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! |
| art::ScopedThreadSuspension sts(self_, art::ThreadState::kNative); |
| art::ScopedSuspendAll ssa("Final installation of redefined Classes!", /*long_suspend=*/true); |
| for (RedefinitionDataIter data = holder.begin(); data != holder.end(); ++data) { |
| art::ScopedAssertNoThreadSuspension nts("Updating runtime objects for redefinition"); |
| ClassRedefinition& redef = data.GetRedefinition(); |
| if (data.GetSourceClassLoader() != nullptr) { |
| ClassLoaderHelper::UpdateJavaDexFile(data.GetJavaDexFile(), data.GetNewDexFileCookie()); |
| } |
| redef.UpdateClass(data); |
| } |
| RestoreObsoleteMethodMapsIfUnneeded(holder); |
| // TODO We should check for if any of the redefined methods are intrinsic methods here and, if any |
| // are, force a full-world deoptimization before finishing redefinition. If we don't do this then |
| // methods that have been jitted prior to the current redefinition being applied might continue |
| // to use the old versions of the intrinsics! |
| // 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(); |
| return OK; |
| } |
| |
| void Redefiner::ClassRedefinition::UpdateMethods(art::ObjPtr<art::mirror::Class> mclass, |
| const art::dex::ClassDef& class_def) { |
| art::ClassLinker* linker = driver_->runtime_->GetClassLinker(); |
| art::PointerSize image_pointer_size = linker->GetImagePointerSize(); |
| const art::dex::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->GetDeclaredMethods(image_pointer_size)) { |
| const art::dex::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::dex::ProtoId* proto_id = dex_file_->FindProtoId(method_return_idx, new_type_list); |
| CHECK(proto_id != nullptr || old_type_list == nullptr); |
| const art::dex::MethodId* method_id = dex_file_->FindMethodId(declaring_class_id, |
| *new_name_id, |
| *proto_id); |
| 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)); |
| // Clear all the intrinsics related flags. |
| method.SetNotIntrinsic(); |
| } |
| } |
| |
| 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::dex::TypeId* new_declaring_id = |
| dex_file_->FindTypeId(field.GetDeclaringClass()->GetDescriptor(&declaring_class_name)); |
| const art::dex::StringId* new_name_id = dex_file_->FindStringId(field.GetName()); |
| const art::dex::TypeId* new_type_id = dex_file_->FindTypeId(field.GetTypeDescriptor()); |
| CHECK(new_name_id != nullptr && new_type_id != nullptr && new_declaring_id != nullptr); |
| const art::dex::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)); |
| } |
| } |
| } |
| |
| void Redefiner::ClassRedefinition::CollectNewFieldAndMethodMappings( |
| const RedefinitionDataIter& data, |
| std::map<art::ArtMethod*, art::ArtMethod*>* method_map, |
| std::map<art::ArtField*, art::ArtField*>* field_map) { |
| art::ObjPtr<art::mirror::Class> old_cls(data.GetMirrorClass()); |
| art::ObjPtr<art::mirror::Class> new_cls(data.GetNewClassObject()); |
| for (art::ArtField& f : old_cls->GetSFields()) { |
| (*field_map)[&f] = new_cls->FindDeclaredStaticField(f.GetName(), f.GetTypeDescriptor()); |
| } |
| for (art::ArtField& f : old_cls->GetIFields()) { |
| (*field_map)[&f] = new_cls->FindDeclaredInstanceField(f.GetName(), f.GetTypeDescriptor()); |
| } |
| auto new_methods = new_cls->GetMethods(art::kRuntimePointerSize); |
| for (art::ArtMethod& m : old_cls->GetMethods(art::kRuntimePointerSize)) { |
| // No support for finding methods in this way since it's generally not needed. Just do it the |
| // easy way. |
| auto nm_iter = std::find_if( |
| new_methods.begin(), |
| new_methods.end(), |
| [&](art::ArtMethod& cand) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| return cand.GetNameView() == m.GetNameView() && cand.GetSignature() == m.GetSignature(); |
| }); |
| CHECK(nm_iter != new_methods.end()) |
| << "Could not find redefined version of " << m.PrettyMethod(); |
| (*method_map)[&m] = &(*nm_iter); |
| } |
| } |
| |
| void Redefiner::ClassRedefinition::UpdateClassStructurally(const RedefinitionDataIter& holder) { |
| DCHECK(IsStructuralRedefinition()); |
| // LETS GO. We've got all new class structures so no need to do all the updating of the stacks. |
| // Instead we need to update everything else. |
| // Just replace the class and be done with it. |
| art::Locks::mutator_lock_->AssertExclusiveHeld(driver_->self_); |
| art::ScopedAssertNoThreadSuspension sants(__FUNCTION__); |
| art::ObjPtr<art::mirror::Class> orig(holder.GetMirrorClass()); |
| art::ObjPtr<art::mirror::Class> replacement(holder.GetNewClassObject()); |
| // Collect mappings from old to new fields/methods |
| std::map<art::ArtMethod*, art::ArtMethod*> method_map; |
| std::map<art::ArtField*, art::ArtField*> field_map; |
| CollectNewFieldAndMethodMappings(holder, &method_map, &field_map); |
| // Copy over the fields of the object. |
| CHECK(!orig.IsNull()); |
| CHECK(!replacement.IsNull()); |
| for (art::ArtField& f : orig->GetSFields()) { |
| art::ArtField* new_field = |
| replacement->FindDeclaredStaticField(f.GetName(), f.GetTypeDescriptor()); |
| CHECK(new_field != nullptr) << "could not find new version of " << f.PrettyField(); |
| art::Primitive::Type ftype = f.GetTypeAsPrimitiveType(); |
| CHECK_EQ(ftype, new_field->GetTypeAsPrimitiveType()) |
| << f.PrettyField() << " vs " << new_field->PrettyField(); |
| if (ftype == art::Primitive::kPrimNot) { |
| new_field->SetObject<false>(replacement, f.GetObject(orig)); |
| } else { |
| switch (ftype) { |
| #define UPDATE_FIELD(TYPE) \ |
| case art::Primitive::kPrim##TYPE: \ |
| new_field->Set##TYPE<false>(replacement, f.Get##TYPE(orig)); \ |
| break |
| |
| UPDATE_FIELD(Int); |
| UPDATE_FIELD(Float); |
| UPDATE_FIELD(Long); |
| UPDATE_FIELD(Double); |
| UPDATE_FIELD(Short); |
| UPDATE_FIELD(Char); |
| UPDATE_FIELD(Byte); |
| UPDATE_FIELD(Boolean); |
| case art::Primitive::kPrimNot: |
| case art::Primitive::kPrimVoid: |
| LOG(FATAL) << "Unexpected field with type " << ftype << " found!"; |
| UNREACHABLE(); |
| #undef UPDATE_FIELD |
| } |
| } |
| } |
| // Mark old class obsolete. |
| orig->SetObsoleteObject(); |
| // Mark methods obsolete. We need to wait until later to actually clear the jit data. |
| for (art::ArtMethod& m : orig->GetMethods(art::kRuntimePointerSize)) { |
| m.SetIsObsolete(); |
| m.SetDontCompile(); |
| DCHECK_EQ(orig, m.GetDeclaringClass()); |
| } |
| // Copy the lock-word |
| replacement->SetLockWord(orig->GetLockWord(false), false); |
| orig->SetLockWord(art::LockWord::Default(), false); |
| // Update live pointers in ART code. |
| // TODO Performing 2 stack-walks back to back isn't the greatest. We might want to try to combine |
| // it with the one ReplaceReferences does. Doing so would be rather complicated though. |
| driver_->runtime_->VisitReflectiveTargets( |
| [&](art::ArtField* f, const auto& info) REQUIRES(art::Locks::mutator_lock_) { |
| auto it = field_map.find(f); |
| if (it == field_map.end()) { |
| return f; |
| } |
| VLOG(plugin) << "Updating " << info << " object for (field) " << it->second->PrettyField(); |
| return it->second; |
| }, |
| [&](art::ArtMethod* m, const auto& info) REQUIRES(art::Locks::mutator_lock_) { |
| auto it = method_map.find(m); |
| if (it == method_map.end()) { |
| return m; |
| } |
| VLOG(plugin) << "Updating " << info << " object for (method) " |
| << it->second->PrettyMethod(); |
| return it->second; |
| }); |
| |
| // Force every frame of every thread to deoptimize (any frame might have eg offsets compiled in). |
| driver_->runtime_->GetInstrumentation()->DeoptimizeAllThreadFrames(); |
| |
| // Actually perform the general replacement. This doesn't affect ArtMethod/ArtFields. |
| // This replaces the mirror::Class in 'holder' as well. It's magic! |
| HeapExtensions::ReplaceReference(driver_->self_, orig, replacement); |
| |
| // Save the old class so that the JIT gc doesn't get confused by it being collected before the |
| // jit code. This is also needed to keep the dex-caches of any obsolete methods live. |
| replacement->GetExtData()->SetObsoleteClass(orig); |
| |
| // Clear the static fields of the old-class. |
| for (art::ArtField& f : orig->GetSFields()) { |
| switch (f.GetTypeAsPrimitiveType()) { |
| #define UPDATE_FIELD(TYPE) \ |
| case art::Primitive::kPrim ## TYPE: \ |
| f.Set ## TYPE <false>(orig, 0); \ |
| break |
| |
| UPDATE_FIELD(Int); |
| UPDATE_FIELD(Float); |
| UPDATE_FIELD(Long); |
| UPDATE_FIELD(Double); |
| UPDATE_FIELD(Short); |
| UPDATE_FIELD(Char); |
| UPDATE_FIELD(Byte); |
| UPDATE_FIELD(Boolean); |
| case art::Primitive::kPrimNot: |
| f.SetObject<false>(orig, nullptr); |
| break; |
| case art::Primitive::kPrimVoid: |
| LOG(FATAL) << "Unexpected field with type void found!"; |
| UNREACHABLE(); |
| #undef UPDATE_FIELD |
| } |
| } |
| |
| art::jit::Jit* jit = driver_->runtime_->GetJit(); |
| if (jit != nullptr) { |
| // Clear jit. |
| // TODO We might want to have some way to tell the JIT not to wait the kJitSamplesBatchSize |
| // invokes to start compiling things again. |
| jit->GetCodeCache()->InvalidateAllCompiledCode(); |
| } |
| |
| // Clear thread caches |
| { |
| // TODO We might be able to avoid doing this but given the rather unstructured nature of the |
| // interpreter cache it's probably not worth the effort. |
| art::MutexLock mu(driver_->self_, *art::Locks::thread_list_lock_); |
| driver_->runtime_->GetThreadList()->ForEach( |
| [](art::Thread* t) { t->GetInterpreterCache()->Clear(t); }); |
| } |
| |
| if (art::kIsDebugBuild) { |
| // Just make sure we didn't screw up any of the now obsolete methods or fields. We need their |
| // declaring-class to still be the obolete class |
| orig->VisitMethods([&](art::ArtMethod* method) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| DCHECK_EQ(method->GetDeclaringClass(), orig) << method->GetDeclaringClass()->PrettyClass() |
| << " vs " << orig->PrettyClass(); |
| }, art::kRuntimePointerSize); |
| orig->VisitFields([&](art::ArtField* field) REQUIRES_SHARED(art::Locks::mutator_lock_) { |
| DCHECK_EQ(field->GetDeclaringClass(), orig) << field->GetDeclaringClass()->PrettyClass() |
| << " vs " << orig->PrettyClass(); |
| }); |
| } |
| } |
| |
| // Redefines the class in place |
| void Redefiner::ClassRedefinition::UpdateClassInPlace(const RedefinitionDataIter& holder) { |
| art::ObjPtr<art::mirror::Class> mclass(holder.GetMirrorClass()); |
| // TODO Rewrite so we don't do a stack walk for each and every class. |
| FindAndAllocateObsoleteMethods(mclass); |
| art::ObjPtr<art::mirror::DexCache> new_dex_cache(holder.GetNewDexCache()); |
| art::ObjPtr<art::mirror::Object> original_dex_file(holder.GetOriginalDexFile()); |
| DCHECK_EQ(dex_file_->NumClassDefs(), 1u); |
| const art::dex::ClassDef& class_def = dex_file_->GetClassDef(0); |
| UpdateMethods(mclass, class_def); |
| UpdateFields(mclass); |
| |
| art::ObjPtr<art::mirror::ClassExt> ext(mclass->GetExtData()); |
| CHECK(!ext.IsNull()); |
| ext->SetOriginalDexFile(original_dex_file); |
| |
| // If this is the first time the class is being redefined, store |
| // the native DexFile pointer and initial ClassDef index in ClassExt. |
| // This preserves the pointer for hiddenapi access checks which need |
| // to read access flags from the initial DexFile. |
| if (ext->GetPreRedefineDexFile() == nullptr) { |
| ext->SetPreRedefineDexFile(&mclass->GetDexFile()); |
| ext->SetPreRedefineClassDefIndex(mclass->GetDexClassDefIndex()); |
| } |
| |
| // 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()))); |
| |
| // Notify the jit that all the methods in this class were redefined. Need to do this last since |
| // the jit relies on the dex_file_ being correct (for native methods at least) to find the method |
| // meta-data. |
| art::jit::Jit* jit = driver_->runtime_->GetJit(); |
| if (jit != nullptr) { |
| art::PointerSize image_pointer_size = |
| driver_->runtime_->GetClassLinker()->GetImagePointerSize(); |
| auto code_cache = jit->GetCodeCache(); |
| // Non-invokable methods don't have any JIT data associated with them so we don't need to tell |
| // the jit about them. |
| for (art::ArtMethod& method : mclass->GetDeclaredMethods(image_pointer_size)) { |
| if (method.IsInvokable()) { |
| code_cache->NotifyMethodRedefined(&method); |
| } |
| } |
| } |
| } |
| |
| // Performs final updates to class for redefinition. |
| void Redefiner::ClassRedefinition::UpdateClass(const RedefinitionDataIter& holder) { |
| if (IsStructuralRedefinition()) { |
| UpdateClassStructurally(holder); |
| } else { |
| UpdateClassInPlace(holder); |
| } |
| } |
| |
| // Restores the old obsolete methods maps if it turns out they weren't needed (ie there were no new |
| // obsolete methods). |
| void Redefiner::ClassRedefinition::RestoreObsoleteMethodMapsIfUnneeded( |
| const RedefinitionDataIter* cur_data) { |
| if (IsStructuralRedefinition()) { |
| // We didn't touch these in this case. |
| return; |
| } |
| art::ObjPtr<art::mirror::Class> klass = GetMirrorClass(); |
| art::ObjPtr<art::mirror::ClassExt> ext = klass->GetExtData(); |
| art::ObjPtr<art::mirror::PointerArray> methods = ext->GetObsoleteMethods(); |
| art::ObjPtr<art::mirror::PointerArray> old_methods = cur_data->GetOldObsoleteMethods(); |
| int32_t old_length = old_methods == nullptr ? 0 : old_methods->GetLength(); |
| int32_t expected_length = |
| old_length + klass->NumDirectMethods() + klass->NumDeclaredVirtualMethods(); |
| // Check to make sure we are only undoing this one. |
| if (methods.IsNull()) { |
| // No new obsolete methods! We can get rid of the maps. |
| ext->SetObsoleteArrays(cur_data->GetOldObsoleteMethods(), cur_data->GetOldDexCaches()); |
| } else if (expected_length == methods->GetLength()) { |
| for (int32_t i = 0; i < expected_length; i++) { |
| art::ArtMethod* expected = nullptr; |
| if (i < old_length) { |
| expected = old_methods->GetElementPtrSize<art::ArtMethod*>(i, art::kRuntimePointerSize); |
| } |
| if (methods->GetElementPtrSize<art::ArtMethod*>(i, art::kRuntimePointerSize) != expected) { |
| // We actually have some new obsolete methods. Just abort since we cannot safely shrink the |
| // obsolete methods array. |
| return; |
| } |
| } |
| // No new obsolete methods! We can get rid of the maps. |
| ext->SetObsoleteArrays(cur_data->GetOldObsoleteMethods(), cur_data->GetOldDexCaches()); |
| } |
| } |
| |
| // This function does all (java) allocations we need to do for the Class being redefined. |
| // TODO Change this name maybe? |
| bool Redefiner::ClassRedefinition::EnsureClassAllocationsFinished( |
| /*out*/RedefinitionDataIter* cur_data) { |
| art::StackHandleScope<2> hs(driver_->self_); |
| art::Handle<art::mirror::Class> klass(hs.NewHandle( |
| driver_->self_->DecodeJObject(klass_)->AsClass())); |
| if (klass == nullptr) { |
| RecordFailure(ERR(INVALID_CLASS), "Unable to decode class argument!"); |
| return false; |
| } |
| // Allocate the classExt |
| art::Handle<art::mirror::ClassExt> ext = |
| hs.NewHandle(art::mirror::Class::EnsureExtDataPresent(klass, driver_->self_)); |
| if (ext == nullptr) { |
| // No memory. Clear exception (it's not useful) and return error. |
| driver_->self_->AssertPendingOOMException(); |
| driver_->self_->ClearException(); |
| RecordFailure(ERR(OUT_OF_MEMORY), "Could not allocate ClassExt"); |
| return false; |
| } |
| if (!IsStructuralRedefinition()) { |
| // First save the old values of the 2 arrays that make up the obsolete methods maps. Then |
| // 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. |
| cur_data->SetOldObsoleteMethods(ext->GetObsoleteMethods()); |
| cur_data->SetOldDexCaches(ext->GetObsoleteDexCaches()); |
| if (!art::mirror::ClassExt::ExtendObsoleteArrays( |
| ext, 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 |