7126ba42f6
the watchdog, via the watchdog(9) interface. For that, the WD_LASTVAL bitwise operation is used. It is mutually exclusive with any explicit timout passing to the watchdogs. The last timeout can be returned via the wdog_kern_last_timeout() KPI. - Add the possibility to pat the watchdogs installed via the watchdog(9) interface from the kernel. In order to do that the new KPI wdog_kern_pat() is offered and it does accept normalized nanoseconds or WD_LASTVAL. - Avoid to pass WD_ACTIVE down in the watchdog handlers. All the control bit processing should over to the upper layer functions and not passed down to the handlers at all. These changes are intended to be used in order to fix up the watchdog tripping in situation when the userland is busted, but protection is still wanted (examples: shutdown syncing / disk dumping). Sponsored by: Sandvine Incorporated Reviewed by: emaste, des, cognet MFC after: 2 weeks
137 lines
3.5 KiB
C
137 lines
3.5 KiB
C
/*-
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* Copyright (c) 2004 Poul-Henning Kamp
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer
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* in this position and unchanged.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/conf.h>
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#include <sys/uio.h>
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#include <sys/kernel.h>
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#include <sys/malloc.h>
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#include <sys/module.h>
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#include <sys/watchdog.h>
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#include <sys/bus.h>
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#include <machine/bus.h>
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static struct cdev *wd_dev;
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static volatile u_int wd_last_u;
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static int
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kern_do_pat(u_int utim)
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{
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int error;
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if ((utim & WD_LASTVAL) != 0 && (utim & WD_INTERVAL) > 0)
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return (EINVAL);
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if ((utim & WD_LASTVAL) != 0) {
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MPASS((wd_last_u & ~WD_INTERVAL) == 0);
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utim &= ~WD_LASTVAL;
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utim |= wd_last_u;
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} else
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wd_last_u = (utim & WD_INTERVAL);
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if ((utim & WD_INTERVAL) == WD_TO_NEVER) {
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utim = 0;
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/* Assume all is well; watchdog signals failure. */
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error = 0;
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} else {
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/* Assume no watchdog available; watchdog flags success */
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error = EOPNOTSUPP;
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}
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EVENTHANDLER_INVOKE(watchdog_list, utim, &error);
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return (error);
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}
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static int
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wd_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data,
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int flags __unused, struct thread *td)
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{
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u_int u;
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if (cmd != WDIOCPATPAT)
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return (ENOIOCTL);
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u = *(u_int *)data;
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if (u & ~(WD_ACTIVE | WD_PASSIVE | WD_LASTVAL | WD_INTERVAL))
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return (EINVAL);
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if ((u & (WD_ACTIVE | WD_PASSIVE)) == (WD_ACTIVE | WD_PASSIVE))
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return (EINVAL);
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if ((u & (WD_ACTIVE | WD_PASSIVE)) == 0 && ((u & WD_INTERVAL) > 0 ||
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(u & WD_LASTVAL) != 0))
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return (EINVAL);
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if (u & WD_PASSIVE)
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return (ENOSYS); /* XXX Not implemented yet */
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u &= ~(WD_ACTIVE | WD_PASSIVE);
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return (kern_do_pat(u));
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}
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u_int
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wdog_kern_last_timeout(void)
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{
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return (wd_last_u);
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}
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int
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wdog_kern_pat(u_int utim)
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{
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if (utim & ~(WD_LASTVAL | WD_INTERVAL))
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return (EINVAL);
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return (kern_do_pat(utim));
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}
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static struct cdevsw wd_cdevsw = {
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.d_version = D_VERSION,
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.d_ioctl = wd_ioctl,
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.d_name = "watchdog",
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};
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static int
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watchdog_modevent(module_t mod __unused, int type, void *data __unused)
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{
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switch(type) {
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case MOD_LOAD:
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wd_dev = make_dev(&wd_cdevsw, 0,
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UID_ROOT, GID_WHEEL, 0600, _PATH_WATCHDOG);
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return 0;
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case MOD_UNLOAD:
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destroy_dev(wd_dev);
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return 0;
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case MOD_SHUTDOWN:
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return 0;
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default:
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return EOPNOTSUPP;
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}
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}
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DEV_MODULE(watchdog, watchdog_modevent, NULL);
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