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 <vector>
23 #include <setjmp.h>
24 #include <stdint.h>
25 
26 #include "base/mutex.h"   // For annotalysis.
27 
28 namespace art {
29 
30 class ArtMethod;
31 class FaultHandler;
32 
33 class FaultManager {
34  public:
35   FaultManager();
36   ~FaultManager();
37 
38   void Init();
39 
40   // Unclaim signals.
41   void Release();
42 
43   // Unclaim signals and delete registered handlers.
44   void Shutdown();
45   void EnsureArtActionInFrontOfSignalChain();
46 
47   void HandleFault(int sig, siginfo_t* info, void* context);
48   void HandleNestedSignal(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   std::vector<FaultHandler*> generated_code_handlers_;
66   std::vector<FaultHandler*> other_handlers_;
67   struct sigaction oldaction_;
68   bool initialized_;
69   DISALLOW_COPY_AND_ASSIGN(FaultManager);
70 };
71 
72 class FaultHandler {
73  public:
74   explicit FaultHandler(FaultManager* manager);
~FaultHandler()75   virtual ~FaultHandler() {}
GetFaultManager()76   FaultManager* GetFaultManager() {
77     return manager_;
78   }
79 
80   virtual bool Action(int sig, siginfo_t* siginfo, void* context) = 0;
81 
82  protected:
83   FaultManager* const manager_;
84 
85  private:
86   DISALLOW_COPY_AND_ASSIGN(FaultHandler);
87 };
88 
89 class NullPointerHandler FINAL : public FaultHandler {
90  public:
91   explicit NullPointerHandler(FaultManager* manager);
92 
93   bool Action(int sig, siginfo_t* siginfo, void* context) OVERRIDE;
94 
95  private:
96   DISALLOW_COPY_AND_ASSIGN(NullPointerHandler);
97 };
98 
99 class SuspensionHandler FINAL : public FaultHandler {
100  public:
101   explicit SuspensionHandler(FaultManager* manager);
102 
103   bool Action(int sig, siginfo_t* siginfo, void* context) OVERRIDE;
104 
105  private:
106   DISALLOW_COPY_AND_ASSIGN(SuspensionHandler);
107 };
108 
109 class StackOverflowHandler FINAL : public FaultHandler {
110  public:
111   explicit StackOverflowHandler(FaultManager* manager);
112 
113   bool Action(int sig, siginfo_t* siginfo, void* context) OVERRIDE;
114 
115  private:
116   DISALLOW_COPY_AND_ASSIGN(StackOverflowHandler);
117 };
118 
119 class JavaStackTraceHandler FINAL : public FaultHandler {
120  public:
121   explicit JavaStackTraceHandler(FaultManager* manager);
122 
123   bool Action(int sig, siginfo_t* siginfo, void* context) OVERRIDE NO_THREAD_SAFETY_ANALYSIS;
124 
125  private:
126   DISALLOW_COPY_AND_ASSIGN(JavaStackTraceHandler);
127 };
128 
129 // Statically allocated so the the signal handler can Get access to it.
130 extern FaultManager fault_manager;
131 
132 }       // namespace art
133 #endif  // ART_RUNTIME_FAULT_HANDLER_H_
134 
135