UnwindCurrent.cpp revision e29609106033a48a6128664668d22bf4fb42a7ee
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/ucontext.h> 18#include <sys/types.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 "UnwindCurrent.h" 28#include "UnwindMap.h" 29 30//------------------------------------------------------------------------- 31// UnwindCurrent functions. 32//------------------------------------------------------------------------- 33UnwindCurrent::UnwindCurrent() { 34} 35 36UnwindCurrent::~UnwindCurrent() { 37} 38 39bool UnwindCurrent::Unwind(size_t num_ignore_frames) { 40 int ret = unw_getcontext(&context_); 41 if (ret < 0) { 42 BACK_LOGW("unw_getcontext failed %d", ret); 43 return false; 44 } 45 return UnwindFromContext(num_ignore_frames, true); 46} 47 48std::string UnwindCurrent::GetFunctionNameRaw(uintptr_t pc, uintptr_t* offset) { 49 *offset = 0; 50 char buf[512]; 51 unw_word_t value; 52 if (unw_get_proc_name_by_ip(unw_local_addr_space, pc, buf, sizeof(buf), 53 &value, &context_) >= 0 && buf[0] != '\0') { 54 *offset = static_cast<uintptr_t>(value); 55 return buf; 56 } 57 return ""; 58} 59 60bool UnwindCurrent::UnwindFromContext(size_t num_ignore_frames, bool resolve) { 61 // The cursor structure is pretty large, do not put it on the stack. 62 unw_cursor_t* cursor = new unw_cursor_t; 63 int ret = unw_init_local(cursor, &context_); 64 if (ret < 0) { 65 BACK_LOGW("unw_init_local failed %d", ret); 66 delete cursor; 67 return false; 68 } 69 70 std::vector<backtrace_frame_data_t>* frames = GetFrames(); 71 frames->reserve(MAX_BACKTRACE_FRAMES); 72 size_t num_frames = 0; 73 do { 74 unw_word_t pc; 75 ret = unw_get_reg(cursor, UNW_REG_IP, &pc); 76 if (ret < 0) { 77 BACK_LOGW("Failed to read IP %d", ret); 78 break; 79 } 80 unw_word_t sp; 81 ret = unw_get_reg(cursor, UNW_REG_SP, &sp); 82 if (ret < 0) { 83 BACK_LOGW("Failed to read SP %d", ret); 84 break; 85 } 86 87 if (num_ignore_frames == 0) { 88 frames->resize(num_frames+1); 89 backtrace_frame_data_t* frame = &frames->at(num_frames); 90 frame->num = num_frames; 91 frame->pc = static_cast<uintptr_t>(pc); 92 frame->sp = static_cast<uintptr_t>(sp); 93 frame->stack_size = 0; 94 95 if (num_frames > 0) { 96 // Set the stack size for the previous frame. 97 backtrace_frame_data_t* prev = &frames->at(num_frames-1); 98 prev->stack_size = frame->sp - prev->sp; 99 } 100 101 if (resolve) { 102 frame->func_name = GetFunctionName(frame->pc, &frame->func_offset); 103 frame->map = FindMap(frame->pc); 104 } else { 105 frame->map = NULL; 106 frame->func_offset = 0; 107 } 108 num_frames++; 109 } else { 110 num_ignore_frames--; 111 } 112 ret = unw_step (cursor); 113 } while (ret > 0 && num_frames < MAX_BACKTRACE_FRAMES); 114 115 delete cursor; 116 return true; 117} 118 119void UnwindCurrent::ExtractContext(void* sigcontext) { 120 unw_tdep_context_t* context = reinterpret_cast<unw_tdep_context_t*>(&context_); 121 const ucontext_t* uc = reinterpret_cast<const ucontext_t*>(sigcontext); 122 123#if defined(__arm__) 124 context->regs[0] = uc->uc_mcontext.arm_r0; 125 context->regs[1] = uc->uc_mcontext.arm_r1; 126 context->regs[2] = uc->uc_mcontext.arm_r2; 127 context->regs[3] = uc->uc_mcontext.arm_r3; 128 context->regs[4] = uc->uc_mcontext.arm_r4; 129 context->regs[5] = uc->uc_mcontext.arm_r5; 130 context->regs[6] = uc->uc_mcontext.arm_r6; 131 context->regs[7] = uc->uc_mcontext.arm_r7; 132 context->regs[8] = uc->uc_mcontext.arm_r8; 133 context->regs[9] = uc->uc_mcontext.arm_r9; 134 context->regs[10] = uc->uc_mcontext.arm_r10; 135 context->regs[11] = uc->uc_mcontext.arm_fp; 136 context->regs[12] = uc->uc_mcontext.arm_ip; 137 context->regs[13] = uc->uc_mcontext.arm_sp; 138 context->regs[14] = uc->uc_mcontext.arm_lr; 139 context->regs[15] = uc->uc_mcontext.arm_pc; 140#else 141 context->uc_mcontext = uc->uc_mcontext; 142#endif 143} 144 145//------------------------------------------------------------------------- 146// UnwindThread functions. 147//------------------------------------------------------------------------- 148UnwindThread::UnwindThread() { 149} 150 151UnwindThread::~UnwindThread() { 152} 153 154void UnwindThread::ThreadUnwind( 155 siginfo_t* /*siginfo*/, void* sigcontext, size_t num_ignore_frames) { 156 ExtractContext(sigcontext); 157 UnwindFromContext(num_ignore_frames, false); 158} 159 160//------------------------------------------------------------------------- 161// C++ object creation function. 162//------------------------------------------------------------------------- 163Backtrace* CreateCurrentObj(BacktraceMap* map) { 164 return new BacktraceCurrent(new UnwindCurrent(), map); 165} 166 167Backtrace* CreateThreadObj(pid_t tid, BacktraceMap* map) { 168 UnwindThread* thread_obj = new UnwindThread(); 169 return new BacktraceThread(thread_obj, thread_obj, tid, map); 170} 171