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 <string.h>
33 #include <sys/mman.h>
34
35 #include "private/bionic_defs.h"
36 #include "private/ScopedPthreadMutexLocker.h"
37
38 static pthread_mutex_t g_abort_msg_lock = PTHREAD_MUTEX_INITIALIZER;
39
40 struct abort_msg_t {
41 size_t size;
42 char msg[0];
43 };
44
45 abort_msg_t** __abort_message_ptr; // Accessible to __libc_init_common.
46
47 __BIONIC_WEAK_FOR_NATIVE_BRIDGE
android_set_abort_message(const char * msg)48 void android_set_abort_message(const char* msg) {
49 ScopedPthreadMutexLocker locker(&g_abort_msg_lock);
50
51 if (__abort_message_ptr == nullptr) {
52 // We must have crashed _very_ early.
53 return;
54 }
55
56 if (*__abort_message_ptr != nullptr) {
57 // We already have an abort message.
58 // Assume that the first crash is the one most worth reporting.
59 return;
60 }
61
62 size_t size = sizeof(abort_msg_t) + strlen(msg) + 1;
63 void* map = mmap(nullptr, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
64 if (map == MAP_FAILED) {
65 return;
66 }
67
68 abort_msg_t* new_abort_message = reinterpret_cast<abort_msg_t*>(map);
69 new_abort_message->size = size;
70 strcpy(new_abort_message->msg, msg);
71 *__abort_message_ptr = new_abort_message;
72 }
73