1 /* 2 * Copyright (C) 2013 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 _BACKTRACE_BACKTRACE_H 18 #define _BACKTRACE_BACKTRACE_H 19 20 #include <inttypes.h> 21 #include <stdint.h> 22 23 #include <string> 24 #include <vector> 25 26 #include <backtrace/backtrace_constants.h> 27 #include <backtrace/BacktraceMap.h> 28 29 #if __LP64__ 30 #define PRIPTR "016" PRIxPTR 31 typedef uint64_t word_t; 32 #else 33 #define PRIPTR "08" PRIxPTR 34 typedef uint32_t word_t; 35 #endif 36 37 enum BacktraceUnwindError : uint32_t { 38 BACKTRACE_UNWIND_NO_ERROR, 39 // Something failed while trying to perform the setup to begin the unwind. 40 BACKTRACE_UNWIND_ERROR_SETUP_FAILED, 41 // There is no map information to use with the unwind. 42 BACKTRACE_UNWIND_ERROR_MAP_MISSING, 43 // An error occurred that indicates a programming error. 44 BACKTRACE_UNWIND_ERROR_INTERNAL, 45 // The thread to unwind has disappeared before the unwind can begin. 46 BACKTRACE_UNWIND_ERROR_THREAD_DOESNT_EXIST, 47 // The thread to unwind has not responded to a signal in a timely manner. 48 BACKTRACE_UNWIND_ERROR_THREAD_TIMEOUT, 49 // Attempt to do an unsupported operation. 50 BACKTRACE_UNWIND_ERROR_UNSUPPORTED_OPERATION, 51 // Attempt to do an offline unwind without a context. 52 BACKTRACE_UNWIND_ERROR_NO_CONTEXT, 53 }; 54 55 struct backtrace_frame_data_t { 56 size_t num; // The current fame number. 57 uintptr_t pc; // The absolute pc. 58 uintptr_t rel_pc; // The relative pc. 59 uintptr_t sp; // The top of the stack. 60 size_t stack_size; // The size of the stack, zero indicate an unknown stack size. 61 backtrace_map_t map; // The map associated with the given pc. 62 std::string func_name; // The function name associated with this pc, NULL if not found. 63 uintptr_t func_offset; // pc relative to the start of the function, only valid if func_name is not NULL. 64 }; 65 66 #if defined(__APPLE__) 67 struct __darwin_ucontext; 68 typedef __darwin_ucontext ucontext_t; 69 #else 70 struct ucontext; 71 typedef ucontext ucontext_t; 72 #endif 73 74 struct backtrace_stackinfo_t { 75 uint64_t start; 76 uint64_t end; 77 const uint8_t* data; 78 }; 79 80 class Backtrace { 81 public: 82 // Create the correct Backtrace object based on what is to be unwound. 83 // If pid < 0 or equals the current pid, then the Backtrace object 84 // corresponds to the current process. 85 // If pid < 0 or equals the current pid and tid >= 0, then the Backtrace 86 // object corresponds to a thread in the current process. 87 // If pid >= 0 and tid < 0, then the Backtrace object corresponds to a 88 // different process. 89 // Tracing a thread in a different process is not supported. 90 // If map is NULL, then create the map and manage it internally. 91 // If map is not NULL, the map is still owned by the caller. 92 static Backtrace* Create(pid_t pid, pid_t tid, BacktraceMap* map = NULL); 93 94 // Create an offline Backtrace object that can be used to do an unwind without a process 95 // that is still running. If cache_file is set to true, then elf information will be cached 96 // for this call. The cached information survives until the calling process ends. This means 97 // that subsequent calls to create offline Backtrace objects will continue to use the same 98 // cache. It also assumes that the elf files used for each offline unwind are the same. 99 static Backtrace* CreateOffline(pid_t pid, pid_t tid, BacktraceMap* map, 100 const backtrace_stackinfo_t& stack, bool cache_file = false); 101 102 virtual ~Backtrace(); 103 104 // Get the current stack trace and store in the backtrace_ structure. 105 virtual bool Unwind(size_t num_ignore_frames, ucontext_t* context = NULL) = 0; 106 107 // Get the function name and offset into the function given the pc. 108 // If the string is empty, then no valid function name was found, 109 // or the pc is not in any valid map. 110 virtual std::string GetFunctionName(uintptr_t pc, uintptr_t* offset, 111 const backtrace_map_t* map = NULL); 112 113 // Fill in the map data associated with the given pc. 114 virtual void FillInMap(uintptr_t pc, backtrace_map_t* map); 115 116 // Read the data at a specific address. 117 virtual bool ReadWord(uintptr_t ptr, word_t* out_value) = 0; 118 119 // Read arbitrary data from a specific address. If a read request would 120 // span from one map to another, this call only reads up until the end 121 // of the current map. 122 // Returns the total number of bytes actually read. 123 virtual size_t Read(uintptr_t addr, uint8_t* buffer, size_t bytes) = 0; 124 125 // Create a string representing the formatted line of backtrace information 126 // for a single frame. 127 virtual std::string FormatFrameData(size_t frame_num); 128 virtual std::string FormatFrameData(const backtrace_frame_data_t* frame); 129 Pid()130 pid_t Pid() const { return pid_; } Tid()131 pid_t Tid() const { return tid_; } NumFrames()132 size_t NumFrames() const { return frames_.size(); } 133 GetFrame(size_t frame_num)134 const backtrace_frame_data_t* GetFrame(size_t frame_num) { 135 if (frame_num >= frames_.size()) { 136 return NULL; 137 } 138 return &frames_[frame_num]; 139 } 140 141 typedef std::vector<backtrace_frame_data_t>::iterator iterator; begin()142 iterator begin() { return frames_.begin(); } end()143 iterator end() { return frames_.end(); } 144 145 typedef std::vector<backtrace_frame_data_t>::const_iterator const_iterator; begin()146 const_iterator begin() const { return frames_.begin(); } end()147 const_iterator end() const { return frames_.end(); } 148 GetMap()149 BacktraceMap* GetMap() { return map_; } 150 GetError()151 BacktraceUnwindError GetError() { return error_; } 152 153 std::string GetErrorString(BacktraceUnwindError error); 154 155 protected: 156 Backtrace(pid_t pid, pid_t tid, BacktraceMap* map); 157 158 // The name returned is not demangled, GetFunctionName() takes care of 159 // demangling the name. 160 virtual std::string GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) = 0; 161 162 virtual bool VerifyReadWordArgs(uintptr_t ptr, word_t* out_value); 163 164 bool BuildMap(); 165 166 pid_t pid_; 167 pid_t tid_; 168 169 BacktraceMap* map_; 170 bool map_shared_; 171 172 std::vector<backtrace_frame_data_t> frames_; 173 174 BacktraceUnwindError error_; 175 }; 176 177 #endif // _BACKTRACE_BACKTRACE_H 178