From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Antonio Quartulli Date: Wed, 11 May 2016 03:29:59 +0800 Message-Id: <1462908605-27412-12-git-send-email-a@unstable.cc> In-Reply-To: <1462908605-27412-1-git-send-email-a@unstable.cc> References: <1462908605-27412-1-git-send-email-a@unstable.cc> Subject: [B.A.T.M.A.N.] [PATCH 11/17] batman-adv: Use kref_get for batadv_gw_select List-Id: The list for a Better Approach To Mobile Ad-hoc Networking List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: davem@davemloft.net Cc: netdev@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org, Antonio Quartulli , Marek Lindner From: Sven Eckelmann batadv_gw_select requires that the caller already has a valid reference for new_gw_node. It is therefore not possible that it has an reference counter of 0 and was still given to this function The kref_get function instead WARNs (with debug information) when the reference counter would still be 0. This makes a bug in batman-adv better visible because kref_get_unless_zero would have ignored this problem. Signed-off-by: Sven Eckelmann Signed-off-by: Marek Lindner Signed-off-by: Antonio Quartulli --- net/batman-adv/gateway_client.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index c59aff5ccac8..bb1c4f37716e 100644 --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -135,8 +135,8 @@ static void batadv_gw_select(struct batadv_priv *bat_priv, spin_lock_bh(&bat_priv->gw.list_lock); - if (new_gw_node && !kref_get_unless_zero(&new_gw_node->refcount)) - new_gw_node = NULL; + if (new_gw_node) + kref_get(&new_gw_node->refcount); curr_gw_node = rcu_dereference_protected(bat_priv->gw.curr_gw, 1); rcu_assign_pointer(bat_priv->gw.curr_gw, new_gw_node); -- 2.8.2