1 /* Copyright (C) 2016 The Android Open Source Project
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This file implements interfaces from the file jvmti.h. This implementation
5 * is licensed under the same terms as the file jvmti.h. The
6 * copyright and license information for the file jvmti.h follows.
7 *
8 * Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights reserved.
9 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
10 *
11 * This code is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License version 2 only, as
13 * published by the Free Software Foundation. Oracle designates this
14 * particular file as subject to the "Classpath" exception as provided
15 * by Oracle in the LICENSE file that accompanied this code.
16 *
17 * This code is distributed in the hope that it will be useful, but WITHOUT
18 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
19 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
20 * version 2 for more details (a copy is included in the LICENSE file that
21 * accompanied this code).
22 *
23 * You should have received a copy of the GNU General Public License version
24 * 2 along with this work; if not, write to the Free Software Foundation,
25 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
26 *
27 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
28 * or visit www.oracle.com if you need additional information or have any
29 * questions.
30 */
31
32 #include "transform.h"
33
34 #include <stddef.h>
35 #include <sys/types.h>
36
37 #include <unordered_map>
38 #include <unordered_set>
39
40 #include "art_method.h"
41 #include "base/array_ref.h"
42 #include "base/globals.h"
43 #include "base/logging.h"
44 #include "base/mem_map.h"
45 #include "class_linker.h"
46 #include "dex/dex_file.h"
47 #include "dex/dex_file_types.h"
48 #include "dex/utf.h"
49 #include "events-inl.h"
50 #include "events.h"
51 #include "fault_handler.h"
52 #include "gc_root-inl.h"
53 #include "handle_scope-inl.h"
54 #include "jni/jni_env_ext-inl.h"
55 #include "jvalue.h"
56 #include "jvmti.h"
57 #include "linear_alloc.h"
58 #include "mirror/array.h"
59 #include "mirror/class-inl.h"
60 #include "mirror/class_ext.h"
61 #include "mirror/class_loader-inl.h"
62 #include "mirror/string-inl.h"
63 #include "oat/oat_file.h"
64 #include "scoped_thread_state_change-inl.h"
65 #include "stack.h"
66 #include "thread_list.h"
67 #include "ti_logging.h"
68 #include "ti_redefine.h"
69
70 namespace openjdkjvmti {
71
72 static EventHandler* gEventHandler = nullptr;
73
Register(EventHandler * eh)74 void Transformer::Register(EventHandler* eh) {
75 gEventHandler = eh;
76 }
77
78 // Initialize templates.
79 template void Transformer::CallClassFileLoadHooksSingleClass<
80 ArtJvmtiEvent::kClassFileLoadHookNonRetransformable>(EventHandler* event_handler,
81 art::Thread* self,
82 /*in-out*/ ArtClassDefinition* def);
83 template void Transformer::CallClassFileLoadHooksSingleClass<
84 ArtJvmtiEvent::kClassFileLoadHookRetransformable>(EventHandler* event_handler,
85 art::Thread* self,
86 /*in-out*/ ArtClassDefinition* def);
87 template void Transformer::CallClassFileLoadHooksSingleClass<
88 ArtJvmtiEvent::kStructuralDexFileLoadHook>(EventHandler* event_handler,
89 art::Thread* self,
90 /*in-out*/ ArtClassDefinition* def);
91
92 template <ArtJvmtiEvent kEvent>
CallClassFileLoadHooksSingleClass(EventHandler * event_handler,art::Thread * self,ArtClassDefinition * def)93 void Transformer::CallClassFileLoadHooksSingleClass(EventHandler* event_handler,
94 art::Thread* self,
95 /*in-out*/ ArtClassDefinition* def) {
96 static_assert(kEvent == ArtJvmtiEvent::kClassFileLoadHookNonRetransformable ||
97 kEvent == ArtJvmtiEvent::kClassFileLoadHookRetransformable ||
98 kEvent == ArtJvmtiEvent::kStructuralDexFileLoadHook,
99 "bad event type");
100 // We don't want to do transitions between calling the event and setting the new data so change to
101 // native state early.
102 art::ScopedThreadStateChange stsc(self, art::ThreadState::kNative);
103 jint new_len = -1;
104 unsigned char* new_data = nullptr;
105 art::ArrayRef<const unsigned char> dex_data = def->GetDexData();
106 event_handler->DispatchEvent<kEvent>(
107 self,
108 static_cast<JNIEnv*>(self->GetJniEnv()),
109 def->GetClass(),
110 def->GetLoader(),
111 def->GetName().c_str(),
112 def->GetProtectionDomain(),
113 static_cast<jint>(dex_data.size()),
114 dex_data.data(),
115 /*out*/&new_len,
116 /*out*/&new_data);
117 def->SetNewDexData(new_len, new_data, kEvent);
118 }
119
120 template <RedefinitionType kType>
CallClassFileLoadHooks(art::Thread * self,std::vector<ArtClassDefinition> * definitions)121 void Transformer::CallClassFileLoadHooks(art::Thread* self,
122 /*in-out*/ std::vector<ArtClassDefinition>* definitions) {
123 if (kType == RedefinitionType::kNormal) {
124 // For normal redefinition we have to call ClassFileLoadHook according to the spec. We use an
125 // internal event "ClassFileLoadHookRetransformable" for agents that can redefine and a
126 // "ClassFileLoadHookNonRetransformable" for agents that cannot redefine. When an agent is
127 // attached to a non-debuggable environment, we cannot redefine any classes. Splitting the
128 // ClassFileLoadHooks allows us to differentiate between these two cases. This method is only
129 // called when redefinition is allowed so just run ClassFileLoadHookRetransformable hooks.
130 for (ArtClassDefinition& def : *definitions) {
131 CallClassFileLoadHooksSingleClass<ArtJvmtiEvent::kClassFileLoadHookRetransformable>(
132 gEventHandler, self, &def);
133 }
134 } else {
135 // For structural redefinition we call StructualDexFileLoadHook in addition to the
136 // ClassFileLoadHooks. This let's us specify if structural modifications are allowed.
137 // TODO(mythria): The spec only specifies we need to call ClassFileLoadHooks, the
138 // StructuralDexFileLoadHooks is internal to ART. It is not clear if we need to run all
139 // StructuralDexFileHooks before ClassFileLoadHooks. Doing it this way to keep the existing
140 // behaviour.
141 for (ArtClassDefinition& def : *definitions) {
142 CallClassFileLoadHooksSingleClass<ArtJvmtiEvent::kStructuralDexFileLoadHook>(
143 gEventHandler, self, &def);
144 }
145 for (ArtClassDefinition& def : *definitions) {
146 CallClassFileLoadHooksSingleClass<ArtJvmtiEvent::kClassFileLoadHookRetransformable>(
147 gEventHandler, self, &def);
148 }
149 }
150 }
151
152 template void Transformer::CallClassFileLoadHooks<RedefinitionType::kNormal>(
153 art::Thread* self, /*in-out*/ std::vector<ArtClassDefinition>* definitions);
154 template void Transformer::CallClassFileLoadHooks<RedefinitionType::kStructural>(
155 art::Thread* self, /*in-out*/ std::vector<ArtClassDefinition>* definitions);
156
RetransformClasses(jvmtiEnv * env,jint class_count,const jclass * classes)157 jvmtiError Transformer::RetransformClasses(jvmtiEnv* env,
158 jint class_count,
159 const jclass* classes) {
160 if (class_count < 0) {
161 JVMTI_LOG(WARNING, env) << "FAILURE TO RETRANSFORM class_count was less then 0";
162 return ERR(ILLEGAL_ARGUMENT);
163 } else if (class_count == 0) {
164 // We don't actually need to do anything. Just return OK.
165 return OK;
166 } else if (classes == nullptr) {
167 JVMTI_LOG(WARNING, env) << "FAILURE TO RETRANSFORM null classes!";
168 return ERR(NULL_POINTER);
169 }
170 art::Thread* self = art::Thread::Current();
171 art::Runtime* runtime = art::Runtime::Current();
172 // A holder that will Deallocate all the class bytes buffers on destruction.
173 std::string error_msg;
174 std::vector<ArtClassDefinition> definitions;
175 jvmtiError res = OK;
176 for (jint i = 0; i < class_count; i++) {
177 res = Redefiner::CanRedefineClass<RedefinitionType::kNormal>(classes[i], &error_msg);
178 if (res != OK) {
179 JVMTI_LOG(WARNING, env) << "FAILURE TO RETRANSFORM " << error_msg;
180 return res;
181 }
182 ArtClassDefinition def;
183 res = def.Init(self, classes[i]);
184 if (res != OK) {
185 JVMTI_LOG(WARNING, env) << "FAILURE TO RETRANSFORM definition init failed";
186 return res;
187 }
188 definitions.push_back(std::move(def));
189 }
190
191 CallClassFileLoadHooks<RedefinitionType::kStructural>(self, &definitions);
192 RedefinitionType redef_type =
193 std::any_of(definitions.cbegin(),
194 definitions.cend(),
195 [](const auto& it) { return it.HasStructuralChanges(); })
196 ? RedefinitionType::kStructural
197 : RedefinitionType::kNormal;
198 res = Redefiner::RedefineClassesDirect(
199 ArtJvmTiEnv::AsArtJvmTiEnv(env), runtime, self, definitions, redef_type, &error_msg);
200 if (res != OK) {
201 JVMTI_LOG(WARNING, env) << "FAILURE TO RETRANSFORM " << error_msg;
202 }
203 return res;
204 }
205
206 // TODO Move this somewhere else, ti_class?
GetClassLocation(ArtJvmTiEnv * env,jclass klass,std::string * location)207 jvmtiError GetClassLocation(ArtJvmTiEnv* env, jclass klass, /*out*/std::string* location) {
208 JNIEnv* jni_env = nullptr;
209 jint ret = env->art_vm->GetEnv(reinterpret_cast<void**>(&jni_env), JNI_VERSION_1_1);
210 if (ret != JNI_OK) {
211 // TODO Different error might be better?
212 return ERR(INTERNAL);
213 }
214 art::ScopedObjectAccess soa(jni_env);
215 art::StackHandleScope<1> hs(art::Thread::Current());
216 art::Handle<art::mirror::Class> hs_klass(hs.NewHandle(soa.Decode<art::mirror::Class>(klass)));
217 const art::DexFile& dex = hs_klass->GetDexFile();
218 *location = dex.GetLocation();
219 return OK;
220 }
221
222 } // namespace openjdkjvmti
223