Date: Thu, 25 Nov 2004 19:16:41 GMT From: Alex Hoff <ahoff@sandvine.com> To: freebsd-gnats-submit@FreeBSD.org Subject: kern/74386: Killing watchdogd does not shutdown watchdog Message-ID: <200411251916.iAPJGfqL082949@www.freebsd.org> Resent-Message-ID: <200411251920.iAPJKVCV028502@freefall.freebsd.org>
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>Number: 74386
>Category: kern
>Synopsis: Killing watchdogd does not shutdown watchdog
>Confidential: no
>Severity: serious
>Priority: low
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Thu Nov 25 19:20:31 GMT 2004
>Closed-Date:
>Last-Modified:
>Originator: Alex Hoff
>Release: 5.3 RELEASE
>Organization:
Sandvine Inc
>Environment:
FreeBSD 5.3 Release
>Description:
watchdogd when exiting will with remove the WD_ACTIVE flag by calling wd_ioctl with that bit set to 0. This is supposed to disable the watchdog, but since kern_clock.c:watchdog_config does not check to see if the ACTIVE flag is set, it will NEVER hit the "watchdog_enabled = 0;" code. Thus, when you kill watchdogd and stop kicking the watchdog, it will panic.
>How-To-Repeat:
Load the software watchdog and kill watchdogd. The kernel should panic in ~15 seconds (depending on your timeout).
>Fix:
Patch:
Check to make sure the watchdog is actually active. Also remove duplicate WD_INTERVAL line.
--- kern_clock.c 2004-11-25 14:01:59.000000000 -0500
+++ kern_clock.old 2004-11-25 14:01:41.000000000 -0500
@@ -503,7 +503,8 @@
u_int u;
u = cmd & WD_INTERVAL;
+ if ((cmd & WD_ACTIVE) && u >= WD_TO_1SEC) {
- if (cmd && u >= WD_TO_1SEC) {
- u = cmd & WD_INTERVAL;
watchdog_ticks = (1 << (u - WD_TO_1SEC)) * hz;
watchdog_enabled = 1;
*err = 0;
>Release-Note:
>Audit-Trail:
>Unformatted:
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