d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

- Add the possibility to reuse the already last used timeout when patting

Browse Source 
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
This commit is contained in:
Attilio Rao 2011-04-27 16:43:03 +00:00
parent 0e24a634ce
commit 7126ba42f6
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=221121
3 changed files with 63 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
sys/ddb/db_command.c
View File

@ -724,14 +724,6 @@ db_watchdog(dummy1, dummy2, dummy3, dummy4)
} else if ((tout & WD_INTERVAL) == WD_TO_NEVER) {
db_error("Out of range watchdog interval\n");
return;
} else {
/*
* XXX: Right now we only support WD_ACTIVE, in the future we
* may be possibly needing a more convoluted function for
* dealing with different cases.
*/
tout |= WD_ACTIVE;
}
EVENTHANDLER_INVOKE(watchdog_list, tout, &i);
}

70
sys/dev/watchdog/watchdog.c
View File

@ -40,37 +40,75 @@ __FBSDID("$FreeBSD$");
#include <machine/bus.h>
static struct cdev *wd_dev;
static volatile u_int wd_last_u;
static int
wd_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data,
int flags __unused, struct thread *td)
kern_do_pat(u_int utim)
{
int error;
u_int u;
if (cmd != WDIOCPATPAT)
return (ENOIOCTL);
u = *(u_int *)data;
if (u & ~(WD_ACTIVE | WD_PASSIVE | WD_INTERVAL))
if ((utim & WD_LASTVAL) != 0 && (utim & WD_INTERVAL) > 0)
return (EINVAL);
if ((u & (WD_ACTIVE | WD_PASSIVE)) == (WD_ACTIVE | WD_PASSIVE))
return (EINVAL);
if ((u & (WD_ACTIVE | WD_PASSIVE)) == 0 && (u & WD_INTERVAL) > 0)
return (EINVAL);
if (u & WD_PASSIVE)
return (ENOSYS); /* XXX Not implemented yet */
if ((u & WD_INTERVAL) == WD_TO_NEVER) {
u = 0;
if ((utim & WD_LASTVAL) != 0) {
MPASS((wd_last_u & ~WD_INTERVAL) == 0);
utim &= ~WD_LASTVAL;
utim |= wd_last_u;
} else
wd_last_u = (utim & WD_INTERVAL);
if ((utim & WD_INTERVAL) == WD_TO_NEVER) {
utim = 0;
/* Assume all is well; watchdog signals failure. */
error = 0;
} else {
/* Assume no watchdog available; watchdog flags success */
error = EOPNOTSUPP;
}
EVENTHANDLER_INVOKE(watchdog_list, u, &error);
EVENTHANDLER_INVOKE(watchdog_list, utim, &error);
return (error);
}
static int
wd_ioctl(struct cdev *dev __unused, u_long cmd, caddr_t data,
int flags __unused, struct thread *td)
{
u_int u;
if (cmd != WDIOCPATPAT)
return (ENOIOCTL);
u = *(u_int *)data;
if (u & ~(WD_ACTIVE | WD_PASSIVE | WD_LASTVAL | WD_INTERVAL))
return (EINVAL);
if ((u & (WD_ACTIVE | WD_PASSIVE)) == (WD_ACTIVE | WD_PASSIVE))
return (EINVAL);
if ((u & (WD_ACTIVE | WD_PASSIVE)) == 0 && ((u & WD_INTERVAL) > 0 ||
(u & WD_LASTVAL) != 0))
return (EINVAL);
if (u & WD_PASSIVE)
return (ENOSYS); /* XXX Not implemented yet */
u &= ~(WD_ACTIVE | WD_PASSIVE);
return (kern_do_pat(u));
}
u_int
wdog_kern_last_timeout(void)
{
return (wd_last_u);
}
int
wdog_kern_pat(u_int utim)
{
if (utim & ~(WD_LASTVAL | WD_INTERVAL))
return (EINVAL);
return (kern_do_pat(utim));
}
static struct cdevsw wd_cdevsw = {
.d_version = D_VERSION,
.d_ioctl = wd_ioctl,

9
sys/sys/watchdog.h
View File

@ -50,6 +50,12 @@
* right to the kernel.
*/
#define WD_LASTVAL 0x0200000
/*
* Use the already last used timeout value.
* The kernel will use as timeout the last valid timeout provided.
*/
#define WD_INTERVAL 0x00000ff
/*
* Mask for duration bits.
@ -78,6 +84,9 @@
typedef void (*watchdog_fn)(void *, u_int, int *);
EVENTHANDLER_DECLARE(watchdog_list, watchdog_fn);
u_int wdog_kern_last_timeout(void);
int wdog_kern_pat(u_int utim);
#endif
#endif /* _SYS_WATCHDOG_H */