1 /*
2 * Copyright (C) 2012 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <errno.h>
18 #include <fcntl.h>
19 #include <linux/watchdog.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23
24 #include <android-base/logging.h>
25
26 #include "log.h"
27
28 #ifdef _INIT_INIT_H
29 #error "Do not include init.h in files used by ueventd or watchdogd; it will expose init's globals"
30 #endif
31
32 #define DEV_NAME "/dev/watchdog"
33
34 namespace android {
35 namespace init {
36
watchdogd_main(int argc,char ** argv)37 int watchdogd_main(int argc, char **argv) {
38 InitKernelLogging(argv);
39
40 int interval = 10;
41 if (argc >= 2) interval = atoi(argv[1]);
42
43 int margin = 10;
44 if (argc >= 3) margin = atoi(argv[2]);
45
46 LOG(INFO) << "watchdogd started (interval " << interval << ", margin " << margin << ")!";
47
48 int fd = open(DEV_NAME, O_RDWR|O_CLOEXEC);
49 if (fd == -1) {
50 PLOG(ERROR) << "Failed to open " << DEV_NAME;
51 return 1;
52 }
53
54 int timeout = interval + margin;
55 int ret = ioctl(fd, WDIOC_SETTIMEOUT, &timeout);
56 if (ret) {
57 PLOG(ERROR) << "Failed to set timeout to " << timeout;
58 ret = ioctl(fd, WDIOC_GETTIMEOUT, &timeout);
59 if (ret) {
60 PLOG(ERROR) << "Failed to get timeout";
61 } else {
62 if (timeout > margin) {
63 interval = timeout - margin;
64 } else {
65 interval = 1;
66 }
67 LOG(WARNING) << "Adjusted interval to timeout returned by driver: "
68 << "timeout " << timeout
69 << ", interval " << interval
70 << ", margin " << margin;
71 }
72 }
73
74 while (true) {
75 write(fd, "", 1);
76 sleep(interval);
77 }
78 }
79
80 } // namespace init
81 } // namespace android
82