1// Copyright (c) 2005, Google Inc. 2// All rights reserved. 3// 4// Redistribution and use in source and binary forms, with or without 5// modification, are permitted provided that the following conditions are 6// met: 7// 8// * Redistributions of source code must retain the above copyright 9// notice, this list of conditions and the following disclaimer. 10// * Redistributions in binary form must reproduce the above 11// copyright notice, this list of conditions and the following disclaimer 12// in the documentation and/or other materials provided with the 13// distribution. 14// * Neither the name of Google Inc. nor the names of its 15// contributors may be used to endorse or promote products derived from 16// this software without specific prior written permission. 17// 18// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 21// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 22// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 23// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 24// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 28// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 30// --- 31// Author: Arun Sharma 32// 33// Produce stack trace using libunwind 34 35#ifndef BASE_STACKTRACE_LIBINWIND_INL_H_ 36#define BASE_STACKTRACE_LIBINWIND_INL_H_ 37// Note: this file is included into stacktrace.cc more than once. 38// Anything that should only be defined once should be here: 39 40// We only need local unwinder. 41#define UNW_LOCAL_ONLY 42 43extern "C" { 44#include <assert.h> 45#include <string.h> // for memset() 46#include <libunwind.h> 47} 48#include "gperftools/stacktrace.h" 49#include "base/logging.h" 50 51// Sometimes, we can try to get a stack trace from within a stack 52// trace, because libunwind can call mmap (maybe indirectly via an 53// internal mmap based memory allocator), and that mmap gets trapped 54// and causes a stack-trace request. If were to try to honor that 55// recursive request, we'd end up with infinite recursion or deadlock. 56// Luckily, it's safe to ignore those subsequent traces. In such 57// cases, we return 0 to indicate the situation. 58static __thread int recursive; 59 60#endif // BASE_STACKTRACE_LIBINWIND_INL_H_ 61 62// Note: this part of the file is included several times. 63// Do not put globals below. 64 65// The following 4 functions are generated from the code below: 66// GetStack{Trace,Frames}() 67// GetStack{Trace,Frames}WithContext() 68// 69// These functions take the following args: 70// void** result: the stack-trace, as an array 71// int* sizes: the size of each stack frame, as an array 72// (GetStackFrames* only) 73// int max_depth: the size of the result (and sizes) array(s) 74// int skip_count: how many stack pointers to skip before storing in result 75// void* ucp: a ucontext_t* (GetStack{Trace,Frames}WithContext only) 76int GET_STACK_TRACE_OR_FRAMES { 77 void *ip; 78 int n = 0; 79 unw_cursor_t cursor; 80 unw_context_t uc; 81#if IS_STACK_FRAMES 82 unw_word_t sp = 0, next_sp = 0; 83#endif 84 85 if (recursive) { 86 return 0; 87 } 88 ++recursive; 89 90 unw_getcontext(&uc); 91 int ret = unw_init_local(&cursor, &uc); 92 assert(ret >= 0); 93 skip_count++; // Do not include current frame 94 95 while (skip_count--) { 96 if (unw_step(&cursor) <= 0) { 97 goto out; 98 } 99#if IS_STACK_FRAMES 100 if (unw_get_reg(&cursor, UNW_REG_SP, &next_sp)) { 101 goto out; 102 } 103#endif 104 } 105 106 while (n < max_depth) { 107 if (unw_get_reg(&cursor, UNW_REG_IP, (unw_word_t *) &ip) < 0) { 108 break; 109 } 110#if IS_STACK_FRAMES 111 sizes[n] = 0; 112#endif 113 result[n++] = ip; 114 if (unw_step(&cursor) <= 0) { 115 break; 116 } 117#if IS_STACK_FRAMES 118 sp = next_sp; 119 if (unw_get_reg(&cursor, UNW_REG_SP, &next_sp) , 0) { 120 break; 121 } 122 sizes[n - 1] = next_sp - sp; 123#endif 124 } 125out: 126 --recursive; 127 return n; 128} 129