[PATCH net-next 3/6] neigh: don't delete neighbour time in neigh_destroy

[Ying Xue <ying.xue@windriver.com>]

The timer of neighbour should be stopped before neigh_destroy(),
otherwise, this is definitely a bug. Even if we do the deletion of
the timer in neigh_destroy(), it's meaningless as its neighbour
would be freed shortly. So it's better to add a warning message
when detectting timer is pending in neigh_destroy().

Signed-off-by: Ying Xue <ying.xue@windriver.com>
---
 net/core/neighbour.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 5595db3..433b617 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -689,8 +689,10 @@ void neigh_destroy(struct neighbour *neigh)
 		return;
 	}
 
-	if (neigh_del_timer(neigh))
-		pr_warn("Impossible event\n");
+	if (timer_pending(&neigh->timer)) {
+		pr_warn("Timer is pending, impossible event %p\n", neigh);
+		dump_stack();
+	}
 
 	write_lock_bh(&neigh->lock);
 	__skb_queue_purge(&neigh->arp_queue);
-- 
1.7.9.5