kernel/watchdog.c: disable nmi perf event in the error path of enabli…

…ng watchdog In corner cases where softlockup watchdog is not setup successfully, the relevant nmi perf event for hardlockup watchdog could be disabled, then the status of the underlying hardware remains unchanged. Also, if the kthread doesn't start then the hrtimer won't run and the hardlockup detector will falsely fire. Signed-off-by: Hillf Danton <[email protected]> Signed-off-by: Don Zickus <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
adn770 · Apr 28, 2011 · 1409f14 · 1409f14
1 parent 534e3ad
commit 1409f14
Showing 1 changed file with 4 additions and 1 deletion.
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
@@ -430,9 +430,12 @@ static int watchdog_enable(int cpu)
 		p = kthread_create(watchdog, (void *)(unsigned long)cpu, "watchdog/%d", cpu);
 		if (IS_ERR(p)) {
 			printk(KERN_ERR "softlockup watchdog for %i failed\n", cpu);
-			if (!err)
+			if (!err) {
 				/* if hardlockup hasn't already set this */
 				err = PTR_ERR(p);
+				/* and disable the perf event */
+				watchdog_nmi_disable(cpu);
+			}
 			goto out;
 		}
 		kthread_bind(p, cpu);