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 #include <sys/types.h> 18 #include <ucontext.h> 19 20 #include <backtrace/Backtrace.h> 21 #include <backtrace/BacktraceMap.h> 22 23 #define UNW_LOCAL_ONLY 24 #include <libunwind.h> 25 26 #include "BacktraceLog.h" 27 #include "BacktraceThread.h" 28 #include "UnwindCurrent.h" 29 #include "UnwindMap.h" 30 31 //------------------------------------------------------------------------- 32 // UnwindCurrent functions. 33 //------------------------------------------------------------------------- 34 UnwindCurrent::UnwindCurrent() { 35 } 36 37 UnwindCurrent::~UnwindCurrent() { 38 } 39 40 bool UnwindCurrent::Unwind(size_t num_ignore_frames, ucontext_t* ucontext) { 41 if (!ucontext) { 42 int ret = unw_getcontext(&context_); 43 if (ret < 0) { 44 BACK_LOGW("unw_getcontext failed %d", ret); 45 return false; 46 } 47 } 48 else { 49 GetUnwContextFromUcontext(ucontext); 50 } 51 return UnwindFromContext(num_ignore_frames, false); 52 } 53 54 void UnwindCurrent::GetUnwContextFromUcontext(const ucontext_t* ucontext) { 55 unw_tdep_context_t* unw_context = reinterpret_cast<unw_tdep_context_t*>(&context_); 56 57 #if defined(__arm__) 58 unw_context->regs[0] = ucontext->uc_mcontext.arm_r0; 59 unw_context->regs[1] = ucontext->uc_mcontext.arm_r1; 60 unw_context->regs[2] = ucontext->uc_mcontext.arm_r2; 61 unw_context->regs[3] = ucontext->uc_mcontext.arm_r3; 62 unw_context->regs[4] = ucontext->uc_mcontext.arm_r4; 63 unw_context->regs[5] = ucontext->uc_mcontext.arm_r5; 64 unw_context->regs[6] = ucontext->uc_mcontext.arm_r6; 65 unw_context->regs[7] = ucontext->uc_mcontext.arm_r7; 66 unw_context->regs[8] = ucontext->uc_mcontext.arm_r8; 67 unw_context->regs[9] = ucontext->uc_mcontext.arm_r9; 68 unw_context->regs[10] = ucontext->uc_mcontext.arm_r10; 69 unw_context->regs[11] = ucontext->uc_mcontext.arm_fp; 70 unw_context->regs[12] = ucontext->uc_mcontext.arm_ip; 71 unw_context->regs[13] = ucontext->uc_mcontext.arm_sp; 72 unw_context->regs[14] = ucontext->uc_mcontext.arm_lr; 73 unw_context->regs[15] = ucontext->uc_mcontext.arm_pc; 74 #else 75 unw_context->uc_mcontext = ucontext->uc_mcontext; 76 #endif 77 } 78 79 std::string UnwindCurrent::GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) { 80 *offset = 0; 81 char buf[512]; 82 unw_word_t value; 83 if (unw_get_proc_name_by_ip(unw_local_addr_space, pc, buf, sizeof(buf), 84 &value, &context_) >= 0 && buf[0] != '\0') { 85 *offset = static_cast<uintptr_t>(value); 86 return buf; 87 } 88 return ""; 89 } 90 91 bool UnwindCurrent::UnwindFromContext(size_t num_ignore_frames, bool within_handler) { 92 // The cursor structure is pretty large, do not put it on the stack. 93 unw_cursor_t* cursor = new unw_cursor_t; 94 int ret = unw_init_local(cursor, &context_); 95 if (ret < 0) { 96 if (!within_handler) { 97 BACK_LOGW("unw_init_local failed %d", ret); 98 } 99 delete cursor; 100 return false; 101 } 102 103 std::vector<backtrace_frame_data_t>* frames = GetFrames(); 104 frames->reserve(MAX_BACKTRACE_FRAMES); 105 size_t num_frames = 0; 106 do { 107 unw_word_t pc; 108 ret = unw_get_reg(cursor, UNW_REG_IP, &pc); 109 if (ret < 0) { 110 if (!within_handler) { 111 BACK_LOGW("Failed to read IP %d", ret); 112 } 113 break; 114 } 115 unw_word_t sp; 116 ret = unw_get_reg(cursor, UNW_REG_SP, &sp); 117 if (ret < 0) { 118 if (!within_handler) { 119 BACK_LOGW("Failed to read SP %d", ret); 120 } 121 break; 122 } 123 124 if (num_ignore_frames == 0) { 125 frames->resize(num_frames+1); 126 backtrace_frame_data_t* frame = &frames->at(num_frames); 127 frame->num = num_frames; 128 frame->pc = static_cast<uintptr_t>(pc); 129 frame->sp = static_cast<uintptr_t>(sp); 130 frame->stack_size = 0; 131 132 if (num_frames > 0) { 133 // Set the stack size for the previous frame. 134 backtrace_frame_data_t* prev = &frames->at(num_frames-1); 135 prev->stack_size = frame->sp - prev->sp; 136 } 137 138 if (!within_handler) { 139 frame->func_name = GetFunctionName(frame->pc, &frame->func_offset); 140 frame->map = FindMap(frame->pc); 141 } else { 142 frame->map = NULL; 143 frame->func_offset = 0; 144 } 145 num_frames++; 146 } else { 147 num_ignore_frames--; 148 } 149 ret = unw_step (cursor); 150 } while (ret > 0 && num_frames < MAX_BACKTRACE_FRAMES); 151 152 delete cursor; 153 return true; 154 } 155 156 //------------------------------------------------------------------------- 157 // C++ object creation function. 158 //------------------------------------------------------------------------- 159 Backtrace* CreateCurrentObj(BacktraceMap* map) { 160 return new BacktraceCurrent(new UnwindCurrent(), map); 161 } 162 163 Backtrace* CreateThreadObj(pid_t tid, BacktraceMap* map) { 164 return new BacktraceThread(new UnwindCurrent(), tid, map); 165 } 166
