1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
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 copyright
11 * notice, this list of conditions and the following disclaimer in
12 * the documentation and/or other materials provided with the
13 * distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
18 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
19 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
21 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
22 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
23 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
24 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
25 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <android/set_abort_message.h>
30
31 #include <pthread.h>
32 #include <sys/mman.h>
33
34 #include "private/ScopedPthreadMutexLocker.h"
35
36 static pthread_mutex_t g_abort_msg_lock = PTHREAD_MUTEX_INITIALIZER;
37
38 struct abort_msg_t {
39 size_t size;
40 char msg[0];
41 };
42
43 abort_msg_t** __abort_message_ptr; // Accessible to __libc_init_common.
44
android_set_abort_message(const char * msg)45 void android_set_abort_message(const char* msg) {
46 ScopedPthreadMutexLocker locker(&g_abort_msg_lock);
47
48 if (__abort_message_ptr == nullptr) {
49 // We must have crashed _very_ early.
50 return;
51 }
52
53 if (*__abort_message_ptr != nullptr) {
54 // We already have an abort message.
55 // Assume that the first crash is the one most worth reporting.
56 return;
57 }
58
59 size_t size = sizeof(abort_msg_t) + strlen(msg) + 1;
60 void* map = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
61 if (map == MAP_FAILED) {
62 return;
63 }
64
65 abort_msg_t* new_abort_message = reinterpret_cast<abort_msg_t*>(map);
66 new_abort_message->size = size;
67 strcpy(new_abort_message->msg, msg);
68 *__abort_message_ptr = new_abort_message;
69 }
70