In callout_stop(), if a callout is both pending and currently

being serviced return 0 (fail) but it is applicable only
mpsafe callouts.  Thanks to hselasky for finding this.

Differential Revision:	https://reviews.freebsd.org/D3078 (Updated)
Submitted by:		hselasky
Reviewed by:		jch

1 files changed, 7 insertions, 5 deletions

diff --git a/sys/kern/kern_timeout.c b/sys/kern/kern_timeout.c
index 21f4789..995954d 100644
--- a/sys/kern/kern_timeout.c
+++ b/sys/kern/kern_timeout.c
@@ -1379,11 +1379,13 @@ again:
 	}
 	callout_cc_del(c, cc);
 
-	/*
-	 * If we are asked to stop a callout which is currently in progress
-	 * and indeed impossible to stop then return 0.
-	 */
-	not_running = !(cc_exec_curr(cc, direct) == c);
+	if (!use_lock) {
+		/*
+		 * If we are asked to stop a callout which is currently in progress
+		 * and indeed impossible to stop then return 0.
+		 */
+		not_running = !(cc_exec_curr(cc, direct) == c);
+	}
 
 	CC_UNLOCK(cc);
 	return (not_running);