1 /*
2 * Copyright (c) 2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include <info/fatal_message.h>
17
18 #include <pthread.h>
19 #include <stdio.h>
20 #include <string.h>
21 #include <sys/mman.h>
22 #include <sys/prctl.h>
23 #include "musl_log.h"
24
25 static pthread_mutex_t fatal_msg_lock = PTHREAD_MUTEX_INITIALIZER;
26 static fatal_msg_t *fatal_message = NULL;
27
set_fatal_message(const char * msg)28 void set_fatal_message(const char *msg)
29 {
30 pthread_mutex_lock(&fatal_msg_lock);
31
32 if (msg == NULL) {
33 MUSL_LOGW("message null");
34 pthread_mutex_unlock(&fatal_msg_lock);
35 return;
36 }
37
38 if (fatal_message != NULL) {
39 pthread_mutex_unlock(&fatal_msg_lock);
40 return;
41 }
42
43 size_t size = sizeof(fatal_msg_t) + strlen(msg) + 1;
44 void *map = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
45 if (map == MAP_FAILED) {
46 MUSL_LOGW("mmap failed");
47 fatal_message = NULL;
48 pthread_mutex_unlock(&fatal_msg_lock);
49 return;
50 }
51
52 int ret = prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, map, size, "fatal message");
53 if (ret < 0) {
54 MUSL_LOGW("prctl set vma failed");
55 munmap(map, size);
56 fatal_message = NULL;
57 pthread_mutex_unlock(&fatal_msg_lock);
58 return;
59 }
60
61 fatal_message = (fatal_msg_t *)(map);
62 fatal_message->size = size;
63 strcpy(fatal_message->msg, msg);
64 pthread_mutex_unlock(&fatal_msg_lock);
65 return;
66 }
67
get_fatal_message(void)68 fatal_msg_t *get_fatal_message(void)
69 {
70 return fatal_message;
71 }
72