1// Copyright (c) 2012 The Chromium Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style license that can be 3// found in the LICENSE file. 4 5#include "base/debug/stack_trace.h" 6 7#include <android/log.h> 8#include <unwind.h> 9 10#include "base/debug/proc_maps_linux.h" 11#include "base/strings/stringprintf.h" 12#include "base/threading/thread_restrictions.h" 13 14#ifdef __LP64__ 15#define FMT_ADDR "0x%016lx" 16#else 17#define FMT_ADDR "0x%08x" 18#endif 19 20namespace { 21 22struct StackCrawlState { 23 StackCrawlState(uintptr_t* frames, size_t max_depth) 24 : frames(frames), 25 frame_count(0), 26 max_depth(max_depth), 27 have_skipped_self(false) {} 28 29 uintptr_t* frames; 30 size_t frame_count; 31 size_t max_depth; 32 bool have_skipped_self; 33}; 34 35_Unwind_Reason_Code TraceStackFrame(_Unwind_Context* context, void* arg) { 36 StackCrawlState* state = static_cast<StackCrawlState*>(arg); 37 uintptr_t ip = _Unwind_GetIP(context); 38 39 // The first stack frame is this function itself. Skip it. 40 if (ip != 0 && !state->have_skipped_self) { 41 state->have_skipped_self = true; 42 return _URC_NO_REASON; 43 } 44 45 state->frames[state->frame_count++] = ip; 46 if (state->frame_count >= state->max_depth) 47 return _URC_END_OF_STACK; 48 return _URC_NO_REASON; 49} 50 51} // namespace 52 53namespace base { 54namespace debug { 55 56bool EnableInProcessStackDumping() { 57 // When running in an application, our code typically expects SIGPIPE 58 // to be ignored. Therefore, when testing that same code, it should run 59 // with SIGPIPE ignored as well. 60 // TODO(phajdan.jr): De-duplicate this SIGPIPE code. 61 struct sigaction action; 62 memset(&action, 0, sizeof(action)); 63 action.sa_handler = SIG_IGN; 64 sigemptyset(&action.sa_mask); 65 return (sigaction(SIGPIPE, &action, NULL) == 0); 66} 67 68StackTrace::StackTrace() { 69 StackCrawlState state(reinterpret_cast<uintptr_t*>(trace_), kMaxTraces); 70 _Unwind_Backtrace(&TraceStackFrame, &state); 71 count_ = state.frame_count; 72} 73 74void StackTrace::Print() const { 75 std::string backtrace = ToString(); 76 __android_log_write(ANDROID_LOG_ERROR, "chromium", backtrace.c_str()); 77} 78 79// NOTE: Native libraries in APKs are stripped before installing. Print out the 80// relocatable address and library names so host computers can use tools to 81// symbolize and demangle (e.g., addr2line, c++filt). 82void StackTrace::OutputToStream(std::ostream* os) const { 83 std::string proc_maps; 84 std::vector<MappedMemoryRegion> regions; 85 // Allow IO to read /proc/self/maps. Reading this file doesn't hit the disk 86 // since it lives in procfs, and this is currently used to print a stack trace 87 // on fatal log messages in debug builds only. If the restriction is enabled 88 // then it will recursively trigger fatal failures when this enters on the 89 // UI thread. 90 base::ThreadRestrictions::ScopedAllowIO allow_io; 91 if (!ReadProcMaps(&proc_maps)) { 92 __android_log_write( 93 ANDROID_LOG_ERROR, "chromium", "Failed to read /proc/self/maps"); 94 } else if (!ParseProcMaps(proc_maps, ®ions)) { 95 __android_log_write( 96 ANDROID_LOG_ERROR, "chromium", "Failed to parse /proc/self/maps"); 97 } 98 99 for (size_t i = 0; i < count_; ++i) { 100 // Subtract one as return address of function may be in the next 101 // function when a function is annotated as noreturn. 102 uintptr_t address = reinterpret_cast<uintptr_t>(trace_[i]) - 1; 103 104 std::vector<MappedMemoryRegion>::iterator iter = regions.begin(); 105 while (iter != regions.end()) { 106 if (address >= iter->start && address < iter->end && 107 !iter->path.empty()) { 108 break; 109 } 110 ++iter; 111 } 112 113 *os << base::StringPrintf("#%02zd " FMT_ADDR " ", i, address); 114 115 if (iter != regions.end()) { 116 uintptr_t rel_pc = address - iter->start + iter->offset; 117 const char* path = iter->path.c_str(); 118 *os << base::StringPrintf("%s+" FMT_ADDR, path, rel_pc); 119 } else { 120 *os << "<unknown>"; 121 } 122 123 *os << "\n"; 124 } 125} 126 127} // namespace debug 128} // namespace base 129