1// Copyright (c) 2010 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/mac/os_crash_dumps.h"
6
7#include <signal.h>
8#include <unistd.h>
9
10#include "base/basictypes.h"
11#include "base/logging.h"
12
13namespace base {
14namespace mac {
15
16namespace {
17
18void ExitSignalHandler(int sig) {
19  // A call to exit() can call atexit() handlers.  If we SIGSEGV due
20  // to a corrupt heap, and if we have an atexit handler that
21  // allocates or frees memory, we are in trouble if we do not _exit.
22  _exit(128 + sig);
23}
24
25}  // namespace
26
27void DisableOSCrashDumps() {
28  // These are the POSIX signals corresponding to the Mach exceptions that
29  // Apple Crash Reporter handles.  See ux_exception() in xnu's
30  // bsd/uxkern/ux_exception.c and machine_exception() in xnu's
31  // bsd/dev/*/unix_signal.c.
32  const int signals_to_intercept[] = {
33    SIGILL,   // EXC_BAD_INSTRUCTION
34    SIGTRAP,  // EXC_BREAKPOINT
35    SIGFPE,   // EXC_ARITHMETIC
36    SIGBUS,   // EXC_BAD_ACCESS
37    SIGSEGV   // EXC_BAD_ACCESS
38  };
39
40  // For all these signals, just wire things up so we exit immediately.
41  for (size_t i = 0; i < arraysize(signals_to_intercept); ++i) {
42    struct sigaction act = {};
43    act.sa_handler = ExitSignalHandler;
44
45    // It is better to allow the signal handler to run on the stack
46    // registered with sigaltstack(), if one is present.
47    act.sa_flags = SA_ONSTACK;
48
49    if (sigemptyset(&act.sa_mask) != 0)
50      DLOG_ERRNO(FATAL) << "sigemptyset() failed";
51    if (sigaction(signals_to_intercept[i], &act, NULL) != 0)
52      DLOG_ERRNO(FATAL) << "sigaction() failed";
53  }
54}
55
56}  // namespace mac
57}  // namespace base
58