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 defined(__LP64__) 30 #define PRIPTR "016" PRIx64 31 typedef uint64_t word_t; 32 #else 33 #define PRIPTR "08" PRIx64 34 typedef uint32_t word_t; 35 #endif 36 37 enum BacktraceUnwindErrorCode : 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 // The count of frames exceed MAX_BACKTRACE_FRAMES. 54 BACKTRACE_UNWIND_ERROR_EXCEED_MAX_FRAMES_LIMIT, 55 // Failed to read memory. 56 BACKTRACE_UNWIND_ERROR_ACCESS_MEM_FAILED, 57 // Failed to read registers. 58 BACKTRACE_UNWIND_ERROR_ACCESS_REG_FAILED, 59 // Failed to find a function in debug sections. 60 BACKTRACE_UNWIND_ERROR_FIND_PROC_INFO_FAILED, 61 // Failed to execute dwarf instructions in debug sections. 62 BACKTRACE_UNWIND_ERROR_EXECUTE_DWARF_INSTRUCTION_FAILED, 63 // Unwind information is incorrect. 64 BACKTRACE_UNWIND_ERROR_UNWIND_INFO, 65 // Unwind information stopped due to sp/pc repeating. 66 BACKTRACE_UNWIND_ERROR_REPEATED_FRAME, 67 // Unwind information stopped due to invalid elf. 68 BACKTRACE_UNWIND_ERROR_INVALID_ELF, 69 }; 70 71 struct BacktraceUnwindError { 72 enum BacktraceUnwindErrorCode error_code; 73 74 union { 75 // for BACKTRACE_UNWIND_ERROR_ACCESS_MEM_FAILED 76 uint64_t addr; 77 // for BACKTRACE_UNWIND_ERROR_ACCESS_REG_FAILED 78 uint64_t regno; 79 } error_info; 80 BacktraceUnwindErrorBacktraceUnwindError81 BacktraceUnwindError() : error_code(BACKTRACE_UNWIND_NO_ERROR) {} 82 }; 83 84 struct backtrace_frame_data_t { 85 size_t num; // The current fame number. 86 uint64_t pc; // The absolute pc. 87 uint64_t rel_pc; // The relative pc. 88 uint64_t sp; // The top of the stack. 89 size_t stack_size; // The size of the stack, zero indicate an unknown stack size. 90 backtrace_map_t map; // The map associated with the given pc. 91 std::string func_name; // The function name associated with this pc, NULL if not found. 92 uint64_t func_offset; // pc relative to the start of the function, only valid if func_name is not 93 // NULL. 94 }; 95 96 struct backtrace_stackinfo_t { 97 uint64_t start; 98 uint64_t end; 99 const uint8_t* data; 100 }; 101 102 namespace unwindstack { 103 class Regs; 104 } 105 106 class Backtrace { 107 public: 108 enum ArchEnum : uint8_t { 109 ARCH_ARM, 110 ARCH_ARM64, 111 ARCH_X86, 112 ARCH_X86_64, 113 }; 114 115 static void SetGlobalElfCache(bool enable); 116 117 // Create the correct Backtrace object based on what is to be unwound. 118 // If pid < 0 or equals the current pid, then the Backtrace object 119 // corresponds to the current process. 120 // If pid < 0 or equals the current pid and tid >= 0, then the Backtrace 121 // object corresponds to a thread in the current process. 122 // If pid >= 0 and tid < 0, then the Backtrace object corresponds to a 123 // different process. 124 // Tracing a thread in a different process is not supported. 125 // If map is NULL, then create the map and manage it internally. 126 // If map is not NULL, the map is still owned by the caller. 127 static Backtrace* Create(pid_t pid, pid_t tid, BacktraceMap* map = nullptr); 128 129 virtual ~Backtrace(); 130 131 // Get the current stack trace and store in the backtrace_ structure. 132 virtual bool Unwind(size_t num_ignore_frames, void* context = nullptr) = 0; 133 134 static bool Unwind(unwindstack::Regs* regs, BacktraceMap* back_map, 135 std::vector<backtrace_frame_data_t>* frames, size_t num_ignore_frames, 136 std::vector<std::string>* skip_names, BacktraceUnwindError* error = nullptr); 137 138 // Get the function name and offset into the function given the pc. 139 // If the string is empty, then no valid function name was found, 140 // or the pc is not in any valid map. 141 virtual std::string GetFunctionName(uint64_t pc, uint64_t* offset, 142 const backtrace_map_t* map = nullptr); 143 144 // Fill in the map data associated with the given pc. 145 virtual void FillInMap(uint64_t pc, backtrace_map_t* map); 146 147 // Read the data at a specific address. 148 virtual bool ReadWord(uint64_t ptr, word_t* out_value) = 0; 149 150 // Read arbitrary data from a specific address. If a read request would 151 // span from one map to another, this call only reads up until the end 152 // of the current map. 153 // Returns the total number of bytes actually read. 154 virtual size_t Read(uint64_t addr, uint8_t* buffer, size_t bytes) = 0; 155 156 // Create a string representing the formatted line of backtrace information 157 // for a single frame. 158 virtual std::string FormatFrameData(size_t frame_num); 159 static std::string FormatFrameData(const backtrace_frame_data_t* frame); 160 Pid()161 pid_t Pid() const { return pid_; } Tid()162 pid_t Tid() const { return tid_; } NumFrames()163 size_t NumFrames() const { return frames_.size(); } 164 GetFrame(size_t frame_num)165 const backtrace_frame_data_t* GetFrame(size_t frame_num) { 166 if (frame_num >= frames_.size()) { 167 return nullptr; 168 } 169 return &frames_[frame_num]; 170 } 171 172 typedef std::vector<backtrace_frame_data_t>::iterator iterator; begin()173 iterator begin() { return frames_.begin(); } end()174 iterator end() { return frames_.end(); } 175 176 typedef std::vector<backtrace_frame_data_t>::const_iterator const_iterator; begin()177 const_iterator begin() const { return frames_.begin(); } end()178 const_iterator end() const { return frames_.end(); } 179 GetMap()180 BacktraceMap* GetMap() { return map_; } 181 GetError()182 BacktraceUnwindError GetError() { return error_; } 183 184 std::string GetErrorString(BacktraceUnwindError error); 185 186 // Set whether to skip frames in libbacktrace/libunwindstack when doing a local unwind. SetSkipFrames(bool skip_frames)187 void SetSkipFrames(bool skip_frames) { skip_frames_ = skip_frames; } 188 189 protected: 190 Backtrace(pid_t pid, pid_t tid, BacktraceMap* map); 191 192 // The name returned is not demangled, GetFunctionName() takes care of 193 // demangling the name. 194 virtual std::string GetFunctionNameRaw(uint64_t pc, uint64_t* offset) = 0; 195 196 virtual bool VerifyReadWordArgs(uint64_t ptr, word_t* out_value); 197 198 bool BuildMap(); 199 200 pid_t pid_; 201 pid_t tid_; 202 203 BacktraceMap* map_; 204 bool map_shared_; 205 206 std::vector<backtrace_frame_data_t> frames_; 207 208 // Skip frames in libbacktrace/libunwindstack when doing a local unwind. 209 bool skip_frames_ = true; 210 211 BacktraceUnwindError error_; 212 }; 213 214 #endif // _BACKTRACE_BACKTRACE_H 215