1 /* 2 * Copyright (C) 2008 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 18 #ifndef ART_RUNTIME_FAULT_HANDLER_H_ 19 #define ART_RUNTIME_FAULT_HANDLER_H_ 20 21 #include <signal.h> 22 #include <stdint.h> 23 24 #include <vector> 25 26 #include "base/locks.h" // For annotalysis. 27 #include "runtime_globals.h" // For CanDoImplicitNullCheckOn. 28 29 namespace art { 30 31 class ArtMethod; 32 class FaultHandler; 33 34 class FaultManager { 35 public: 36 FaultManager(); 37 ~FaultManager(); 38 39 void Init(); 40 41 // Unclaim signals. 42 void Release(); 43 44 // Unclaim signals and delete registered handlers. 45 void Shutdown(); 46 47 // Try to handle a fault, returns true if successful. 48 bool HandleFault(int sig, siginfo_t* info, void* context); 49 50 // Added handlers are owned by the fault handler and will be freed on Shutdown(). 51 void AddHandler(FaultHandler* handler, bool generated_code); 52 void RemoveHandler(FaultHandler* handler); 53 54 // Note that the following two functions are called in the context of a signal handler. 55 // The IsInGeneratedCode() function checks that the mutator lock is held before it 56 // calls GetMethodAndReturnPCAndSP(). 57 // TODO: think about adding lock assertions and fake lock and unlock functions. 58 void GetMethodAndReturnPcAndSp(siginfo_t* siginfo, void* context, ArtMethod** out_method, 59 uintptr_t* out_return_pc, uintptr_t* out_sp) 60 NO_THREAD_SAFETY_ANALYSIS; 61 bool IsInGeneratedCode(siginfo_t* siginfo, void *context, bool check_dex_pc) 62 NO_THREAD_SAFETY_ANALYSIS; 63 64 private: 65 // The HandleFaultByOtherHandlers function is only called by HandleFault function for generated code. 66 bool HandleFaultByOtherHandlers(int sig, siginfo_t* info, void* context) 67 NO_THREAD_SAFETY_ANALYSIS; 68 69 std::vector<FaultHandler*> generated_code_handlers_; 70 std::vector<FaultHandler*> other_handlers_; 71 struct sigaction oldaction_; 72 bool initialized_; 73 DISALLOW_COPY_AND_ASSIGN(FaultManager); 74 }; 75 76 class FaultHandler { 77 public: 78 explicit FaultHandler(FaultManager* manager); ~FaultHandler()79 virtual ~FaultHandler() {} GetFaultManager()80 FaultManager* GetFaultManager() { 81 return manager_; 82 } 83 84 virtual bool Action(int sig, siginfo_t* siginfo, void* context) = 0; 85 86 protected: 87 FaultManager* const manager_; 88 89 private: 90 DISALLOW_COPY_AND_ASSIGN(FaultHandler); 91 }; 92 93 class NullPointerHandler final : public FaultHandler { 94 public: 95 explicit NullPointerHandler(FaultManager* manager); 96 97 bool Action(int sig, siginfo_t* siginfo, void* context) override; 98 IsValidImplicitCheck(siginfo_t * siginfo)99 static bool IsValidImplicitCheck(siginfo_t* siginfo) { 100 // Our implicit NPE checks always limit the range to a page. 101 // Note that the runtime will do more exhaustive checks (that we cannot 102 // reasonably do in signal processing code) based on the dex instruction 103 // faulting. 104 return CanDoImplicitNullCheckOn(reinterpret_cast<uintptr_t>(siginfo->si_addr)); 105 } 106 107 private: 108 DISALLOW_COPY_AND_ASSIGN(NullPointerHandler); 109 }; 110 111 class SuspensionHandler final : public FaultHandler { 112 public: 113 explicit SuspensionHandler(FaultManager* manager); 114 115 bool Action(int sig, siginfo_t* siginfo, void* context) override; 116 117 private: 118 DISALLOW_COPY_AND_ASSIGN(SuspensionHandler); 119 }; 120 121 class StackOverflowHandler final : public FaultHandler { 122 public: 123 explicit StackOverflowHandler(FaultManager* manager); 124 125 bool Action(int sig, siginfo_t* siginfo, void* context) override; 126 127 private: 128 DISALLOW_COPY_AND_ASSIGN(StackOverflowHandler); 129 }; 130 131 class JavaStackTraceHandler final : public FaultHandler { 132 public: 133 explicit JavaStackTraceHandler(FaultManager* manager); 134 135 bool Action(int sig, siginfo_t* siginfo, void* context) override NO_THREAD_SAFETY_ANALYSIS; 136 137 private: 138 DISALLOW_COPY_AND_ASSIGN(JavaStackTraceHandler); 139 }; 140 141 // Statically allocated so the the signal handler can Get access to it. 142 extern FaultManager fault_manager; 143 144 } // namespace art 145 #endif // ART_RUNTIME_FAULT_HANDLER_H_ 146 147