kernel/watchdog.c: disable nmi perf event in the error path of enabling 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 <dhillf@gmail.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 140dce7..14733d4 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -430,9 +430,12 @@
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);