base/debug/stack_trace_android.cc

   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
  20 namespace {
  21
  22 struct 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
  53 namespace base {
  54 namespace debug {
  55
  56 bool 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
  68 StackTrace::StackTrace() {
  69   StackCrawlState state(reinterpret_cast<uintptr_t*>(trace_), kMaxTraces);
  70   _Unwind_Backtrace(&TraceStackFrame, &state);
  71   count_ = state.frame_count;
  72 }
  73
  74 void 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).
  82 void 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, &regions)) {
  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