Index: head/share/man/man4/watchdog.4 =================================================================== --- head/share/man/man4/watchdog.4 +++ head/share/man/man4/watchdog.4 @@ -25,7 +25,7 @@ .\" .\" $FreeBSD$ .\" -.Dd December 21, 2009 +.Dd January 2, 2018 .Dt WATCHDOG 4 .Os .Sh NAME @@ -40,8 +40,11 @@ .Pp The device .Pa /dev/fido -responds to a single +supports several optional .Xr ioctl 2 +calls for configuration, and +responds to a single operational +.Xr ioctl call, .Dv WDIOCPATPAT . It takes a single argument which represents a timeout value specified as a @@ -60,12 +63,16 @@ will be kept from timing out from the kernel. .Pp The +.Dv WDIOCPATPAT .Xr ioctl 2 call will return success if just one of the available .Xr watchdog 9 implementations supports setting the timeout to the specified timeout. This means that at least one watchdog is armed. +By default, this will be a hardware watchdog if one is present, but if +no hardware watchdog is able to process the request, a default software +watchdog is enabled. If the call fails, for instance if none of .Xr watchdog 9 @@ -77,8 +84,53 @@ If disarming the watchdog(s) failed an error is returned. The watchdog might still be armed! +.Pp +The optional configuration +.Xr ioctl +commands are listed here, along with the type of the parameter used. +Examples of their use can be found in +.Xr watchdogd 8 . +.Bl -tag -width "WDIOC_SETSOFTTIMEOUTACT int " +.It Dv WDIOC_SETTIMEOUT Fa int +set/reset the timer +.It Dv WDIOC_GETTIMEOUT Fa int +get total timeout +.It Dv WDIOC_GETTIMELEFT Fa int +get time left +.It Dv WDIOC_GETPRETIMEOUT Fa int +get the pre-timeout +.It Dv WDIOC_SETPRETIMEOUT Fa int +set the pre-timeout +.It Dv WDIOC_SETPRETIMEOUTACT Fa int +Set the action when a pre-timeout occurs (see +.Li WD_SOFT_* +below). +.It Dv WDIOC_SETSOFT Fa int +Use an internal software watchdog instead of hardware. +There is also an external software watchdog, which is used by default +if no hardware watchdog was attached. +.It Dv WDIOC_SETSOFTTIMEOUTACT Fa int +Set the action whan a soft timeout occurs. +.El +.Pp +The actions that may be specified for the pre-timeout or the internal software +watchdog are listed here. +Multiple actions can be specified by ORing values together. +.Bl -tag -width WD_SOFT_PRINT +.It Dv WD_SOFT_PANIC +panic +.It Dv WD_SOFT_DDB +enter debugger +.It Dv WD_SOFT_LOG +log(9) +.It Dv WD_SOFT_PRINT +printf(9) +.El .Sh RETURN VALUES -The ioctl returns zero on success and non-zero on failure. +The +.Dv WDIOCPATPAT +.Xr ioctl +returns zero on success and non-zero on failure. .Bl -tag -width Er .It Bq Er EOPNOTSUPP No watchdog present in the kernel or @@ -89,6 +141,10 @@ .It Bq Er EINVAL Invalid flag combination passed. .El +.Pp +The configuration +.Xr ioctl +operations return zero on success and non-zero on failure. .Sh EXAMPLES .Bd -literal -offset indent #include @@ -122,8 +178,10 @@ .Pp .Dl "options SW_WATCHDOG" .Pp -in your kernel config adds a software watchdog in the kernel, dropping to KDB -or panic-ing when firing. +in your kernel config forces a software watchdog in the kernel +to be configured even if a hardware watchdog is configured, +dropping to KDB or panicking when firing, depending +on the KDB and KDB_UNATTENDED kernel configuration options. .Sh SEE ALSO .Xr watchdogd 8 , .Xr watchdog 9 Index: head/sys/conf/NOTES =================================================================== --- head/sys/conf/NOTES +++ head/sys/conf/NOTES @@ -2609,7 +2609,9 @@ options BOOTP_BLOCKSIZE=8192 # Override NFS block size # -# Add software watchdog routines. +# Enable software watchdog routines, even if hardware watchdog is present. +# By default, software watchdog timer is enabled only if no hardware watchdog +# is present. # options SW_WATCHDOG Index: head/sys/dev/watchdog/watchdog.c =================================================================== --- head/sys/dev/watchdog/watchdog.c +++ head/sys/dev/watchdog/watchdog.c @@ -78,6 +78,9 @@ static int wd_lastpat_valid = 0; static time_t wd_lastpat = 0; /* when the watchdog was last patted */ +/* Hook for external software watchdog to register for use if needed */ +void (*wdog_software_attach)(void); + static void pow2ns_to_ts(int pow2ns, struct timespec *ts) { @@ -120,6 +123,7 @@ wdog_kern_pat(u_int utim) { int error; + static int first = 1; if ((utim & WD_LASTVAL) != 0 && (utim & WD_INTERVAL) > 0) return (EINVAL); @@ -161,6 +165,17 @@ } else { EVENTHANDLER_INVOKE(watchdog_list, utim, &error); } + /* + * If we no hardware watchdog responded, we have not tried to + * attach an external software watchdog, and one is available, + * attach it now and retry. + */ + if (error == EOPNOTSUPP && first && *wdog_software_attach != NULL) { + (*wdog_software_attach)(); + EVENTHANDLER_INVOKE(watchdog_list, utim, &error); + } + first = 0; + wd_set_pretimeout(wd_pretimeout, true); /* * If we were able to arm/strobe the watchdog, then Index: head/sys/kern/kern_clock.c =================================================================== --- head/sys/kern/kern_clock.c +++ head/sys/kern/kern_clock.c @@ -335,15 +335,19 @@ } } -#ifdef SW_WATCHDOG #include static int watchdog_ticks; static int watchdog_enabled; static void watchdog_fire(void); static void watchdog_config(void *, u_int, int *); -#endif /* SW_WATCHDOG */ +static void +watchdog_attach(void) +{ + EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0); +} + /* * Clock handling routines. * @@ -410,8 +414,14 @@ if (profhz == 0) profhz = i; psratio = profhz / i; + #ifdef SW_WATCHDOG - EVENTHANDLER_REGISTER(watchdog_list, watchdog_config, NULL, 0); + /* Enable hardclock watchdog now, even if a hardware watchdog exists. */ + watchdog_attach(); +#else + /* Volunteer to run a software watchdog. */ + if (wdog_software_attach == NULL) + wdog_software_attach = watchdog_attach; #endif } @@ -482,10 +492,8 @@ #ifdef DEVICE_POLLING hardclock_device_poll(); /* this is very short and quick */ #endif /* DEVICE_POLLING */ -#ifdef SW_WATCHDOG if (watchdog_enabled > 0 && --watchdog_ticks <= 0) watchdog_fire(); -#endif /* SW_WATCHDOG */ } void @@ -496,9 +504,7 @@ struct proc *p = td->td_proc; int *t = DPCPU_PTR(pcputicks); int flags, global, newticks; -#ifdef SW_WATCHDOG int i; -#endif /* SW_WATCHDOG */ /* * Update per-CPU and possibly global ticks values. @@ -558,13 +564,11 @@ atomic_store_rel_int(&devpoll_run, 0); } #endif /* DEVICE_POLLING */ -#ifdef SW_WATCHDOG if (watchdog_enabled > 0) { i = atomic_fetchadd_int(&watchdog_ticks, -newticks); if (i > 0 && i <= newticks) watchdog_fire(); } -#endif /* SW_WATCHDOG */ } if (curcpu == CPU_FIRST()) cpu_tick_calibration(); @@ -841,8 +845,6 @@ 0, 0, sysctl_kern_clockrate, "S,clockinfo", "Rate and period of various kernel clocks"); -#ifdef SW_WATCHDOG - static void watchdog_config(void *unused __unused, u_int cmd, int *error) { @@ -891,5 +893,3 @@ panic("watchdog timeout"); #endif } - -#endif /* SW_WATCHDOG */ Index: head/sys/kern/kern_dump.c =================================================================== --- head/sys/kern/kern_dump.c +++ head/sys/kern/kern_dump.c @@ -27,8 +27,6 @@ #include __FBSDID("$FreeBSD$"); -#include "opt_watchdog.h" - #include #include #include @@ -36,9 +34,7 @@ #include #include #include -#ifdef SW_WATCHDOG #include -#endif #include #include #include @@ -205,9 +201,7 @@ } dumpsys_map_chunk(pa, chunk, &va); -#ifdef SW_WATCHDOG wdog_kern_pat(WD_LASTVAL); -#endif error = dump_append(di, va, 0, sz); dumpsys_unmap_chunk(pa, chunk, va); Index: head/sys/sys/watchdog.h =================================================================== --- head/sys/sys/watchdog.h +++ head/sys/sys/watchdog.h @@ -112,6 +112,14 @@ u_int wdog_kern_last_timeout(void); int wdog_kern_pat(u_int utim); + +/* + * The following function pointer is used to attach a software watchdog + * if no hardware watchdog has been attached, and if the software module + * has initialized the function pointer. + */ + +extern void (*wdog_software_attach)(void); #endif #endif /* _SYS_WATCHDOG_H */