1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef ART_RUNTIME_TI_AGENT_H_ 18 #define ART_RUNTIME_TI_AGENT_H_ 19 20 #include <dlfcn.h> 21 #include <jni.h> // for jint, JavaVM* etc declarations 22 23 #include <memory> 24 25 #include "base/logging.h" 26 27 namespace art { 28 namespace ti { 29 30 class Agent; 31 32 enum LoadError { 33 kNoError, // No error occurred.. 34 kLoadingError, // dlopen or dlsym returned an error. 35 kInitializationError, // The entrypoint did not return 0. This might require an abort. 36 }; 37 38 class AgentSpec { 39 public: 40 explicit AgentSpec(const std::string& arg); 41 GetName()42 const std::string& GetName() const { 43 return name_; 44 } 45 GetArgs()46 const std::string& GetArgs() const { 47 return args_; 48 } 49 HasArgs()50 bool HasArgs() const { 51 return !GetArgs().empty(); 52 } 53 54 std::unique_ptr<Agent> Load(/*out*/jint* call_res, 55 /*out*/LoadError* error, 56 /*out*/std::string* error_msg); 57 58 // Tries to attach the agent using its OnAttach method. Returns true on success. 59 std::unique_ptr<Agent> Attach(JNIEnv* env, 60 jobject class_loader, 61 /*out*/jint* call_res, 62 /*out*/LoadError* error, 63 /*out*/std::string* error_msg); 64 65 private: 66 std::unique_ptr<Agent> DoDlOpen(JNIEnv* env, 67 jobject class_loader, 68 /*out*/LoadError* error, 69 /*out*/std::string* error_msg); 70 71 std::unique_ptr<Agent> DoLoadHelper(JNIEnv* env, 72 bool attaching, 73 jobject class_loader, 74 /*out*/jint* call_res, 75 /*out*/LoadError* error, 76 /*out*/std::string* error_msg); 77 78 std::string name_; 79 std::string args_; 80 81 friend std::ostream& operator<<(std::ostream &os, AgentSpec const& m); 82 }; 83 84 std::ostream& operator<<(std::ostream &os, AgentSpec const& m); 85 86 using AgentOnLoadFunction = jint (*)(JavaVM*, const char*, void*); 87 using AgentOnUnloadFunction = void (*)(JavaVM*); 88 89 // Agents are native libraries that will be loaded by the runtime for the purpose of 90 // instrumentation. They will be entered by Agent_OnLoad or Agent_OnAttach depending on whether the 91 // agent is being attached during runtime startup or later. 92 // 93 // The agent's Agent_OnUnload function will be called during runtime shutdown. 94 // 95 // TODO: consider splitting ti::Agent into command line, agent and shared library handler classes 96 // TODO Support native-bridge. Currently agents can only be the actual runtime ISA of the device. 97 class Agent { 98 public: GetName()99 const std::string& GetName() const { 100 return name_; 101 } 102 103 void* FindSymbol(const std::string& name) const; 104 105 // TODO We need to acquire some locks probably. 106 void Unload(); 107 108 Agent(Agent&& other); 109 Agent& operator=(Agent&& other); 110 111 ~Agent(); 112 113 private: Agent(const std::string & name,void * dlopen_handle)114 Agent(const std::string& name, void* dlopen_handle) : name_(name), 115 dlopen_handle_(dlopen_handle), 116 onload_(nullptr), 117 onattach_(nullptr), 118 onunload_(nullptr) { 119 DCHECK(dlopen_handle != nullptr); 120 } 121 122 void PopulateFunctions(); 123 124 std::string name_; 125 void* dlopen_handle_; 126 127 // The entrypoints. 128 AgentOnLoadFunction onload_; 129 AgentOnLoadFunction onattach_; 130 AgentOnUnloadFunction onunload_; 131 132 friend class AgentSpec; 133 friend std::ostream& operator<<(std::ostream &os, Agent const& m); 134 135 DISALLOW_COPY_AND_ASSIGN(Agent); 136 }; 137 138 std::ostream& operator<<(std::ostream &os, Agent const& m); 139 std::ostream& operator<<(std::ostream &os, const Agent* m); 140 141 } // namespace ti 142 } // namespace art 143 144 #endif // ART_RUNTIME_TI_AGENT_H_ 145 146