Contents of /tags/mkinitrd-6_1_5/busybox/miscutils/watchdog.c
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Wed Aug 5 17:52:52 2009 UTC (15 years, 1 month ago) by niro
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Wed Aug 5 17:52:52 2009 UTC (15 years, 1 month ago) by niro
File MIME type: text/plain
File size: 2238 byte(s)
tagged 'mkinitrd-6_1_5'
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Mini watchdog implementation for busybox |
4 | * |
5 | * Copyright (C) 2003 Paul Mundt <lethal@linux-sh.org> |
6 | * Copyright (C) 2006 Bernhard Reutner-Fischer <busybox@busybox.net> |
7 | * Copyright (C) 2008 Darius Augulis <augulis.darius@gmail.com> |
8 | * |
9 | * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. |
10 | */ |
11 | |
12 | #include "libbb.h" |
13 | #include "linux/watchdog.h" |
14 | |
15 | #define OPT_FOREGROUND (1 << 0) |
16 | #define OPT_STIMER (1 << 1) |
17 | #define OPT_HTIMER (1 << 2) |
18 | |
19 | static void watchdog_shutdown(int sig UNUSED_PARAM) |
20 | { |
21 | static const char V = 'V'; |
22 | |
23 | write(3, &V, 1); /* Magic, see watchdog-api.txt in kernel */ |
24 | if (ENABLE_FEATURE_CLEAN_UP) |
25 | close(3); |
26 | exit(EXIT_SUCCESS); |
27 | } |
28 | |
29 | int watchdog_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
30 | int watchdog_main(int argc, char **argv) |
31 | { |
32 | static const struct suffix_mult suffixes[] = { |
33 | { "ms", 1 }, |
34 | { "", 1000 }, |
35 | { } |
36 | }; |
37 | |
38 | unsigned opts; |
39 | unsigned stimer_duration; /* how often to restart */ |
40 | unsigned htimer_duration = 60000; /* reboots after N ms if not restarted */ |
41 | char *st_arg; |
42 | char *ht_arg; |
43 | |
44 | opt_complementary = "=1"; /* must have exactly 1 argument */ |
45 | opts = getopt32(argv, "Ft:T:", &st_arg, &ht_arg); |
46 | |
47 | if (opts & OPT_HTIMER) |
48 | htimer_duration = xatou_sfx(ht_arg, suffixes); |
49 | stimer_duration = htimer_duration / 2; |
50 | if (opts & OPT_STIMER) |
51 | stimer_duration = xatou_sfx(st_arg, suffixes); |
52 | |
53 | bb_signals(BB_FATAL_SIGS, watchdog_shutdown); |
54 | |
55 | /* Use known fd # - avoid needing global 'int fd' */ |
56 | xmove_fd(xopen(argv[argc - 1], O_WRONLY), 3); |
57 | |
58 | /* WDIOC_SETTIMEOUT takes seconds, not milliseconds */ |
59 | htimer_duration = htimer_duration / 1000; |
60 | ioctl_or_warn(3, WDIOC_SETTIMEOUT, &htimer_duration); |
61 | #if 0 |
62 | ioctl_or_warn(3, WDIOC_GETTIMEOUT, &htimer_duration); |
63 | printf("watchdog: SW timer is %dms, HW timer is %dms\n", |
64 | stimer_duration, htimer_duration * 1000); |
65 | #endif |
66 | |
67 | if (!(opts & OPT_FOREGROUND)) { |
68 | bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv); |
69 | } |
70 | |
71 | while (1) { |
72 | /* |
73 | * Make sure we clear the counter before sleeping, as the counter value |
74 | * is undefined at this point -- PFM |
75 | */ |
76 | write(3, "", 1); /* write zero byte */ |
77 | usleep(stimer_duration * 1000L); |
78 | } |
79 | return EXIT_SUCCESS; /* - not reached, but gcc 4.2.1 is too dumb! */ |
80 | } |