diff options
| -rw-r--r-- | miscutils/watchdog.c | 32 |
1 files changed, 25 insertions, 7 deletions
diff --git a/miscutils/watchdog.c b/miscutils/watchdog.c index 07ae64e..95e2f1a 100644 --- a/miscutils/watchdog.c +++ b/miscutils/watchdog.c @@ -42,17 +42,36 @@ #define OPT_STIMER (1 << 1) #define OPT_HTIMER (1 << 2) -static void watchdog_shutdown(int sig UNUSED_PARAM) +static void shutdown_watchdog(void) { static const char V = 'V'; + write(3, &V, 1); /* Magic, see watchdog-api.txt in kernel */ + close(3); +} +static void shutdown_on_signal(int sig UNUSED_PARAM) +{ remove_pidfile(CONFIG_PID_FILE_PATH "/watchdog.pid"); - write(3, &V, 1); /* Magic, see watchdog-api.txt in kernel */ - if (ENABLE_FEATURE_CLEAN_UP) - close(3); + shutdown_watchdog(); _exit(EXIT_SUCCESS); } +static void watchdog_open(const char* device) +{ + /* Use known fd # - avoid needing global 'int fd' */ + xmove_fd(xopen(device, O_WRONLY), 3); + + /* If the watchdog driver can do something other than cause a reboot + * on a timeout, then it's possible this program may be starting from + * a state when the watchdog hadn't been previously stopped with + * the magic write followed by a close. In this case the driver may + * not start properly, so always do the proper stop first just in case. + */ + shutdown_watchdog(); + + xmove_fd(xopen(device, O_WRONLY), 3); +} + int watchdog_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int watchdog_main(int argc, char **argv) { @@ -86,10 +105,9 @@ int watchdog_main(int argc, char **argv) if (opts & OPT_STIMER) stimer_duration = xatou_sfx(st_arg, suffixes); - bb_signals(BB_FATAL_SIGS, watchdog_shutdown); + bb_signals(BB_FATAL_SIGS, shutdown_on_signal); - /* Use known fd # - avoid needing global 'int fd' */ - xmove_fd(xopen(argv[argc - 1], O_WRONLY), 3); + watchdog_open(argv[argc - 1]); /* WDIOC_SETTIMEOUT takes seconds, not milliseconds */ htimer_duration = htimer_duration / 1000; |