From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: [PATCH 9/9] can: j1939: warn if resources are still linked on destroy Date: Wed, 13 Nov 2019 10:55:50 +0100 Message-ID: <20191113095550.26527-10-mkl@pengutronix.de> References: <20191113095550.26527-1-mkl@pengutronix.de> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20191113095550.26527-1-mkl@pengutronix.de> Sender: netdev-owner@vger.kernel.org To: netdev@vger.kernel.org Cc: davem@davemloft.net, linux-can@vger.kernel.org, kernel@pengutronix.de, Oleksij Rempel List-Id: linux-can.vger.kernel.org From: Oleksij Rempel j1939_session_destroy() and __j1939_priv_release() should be called only if session, ecu or socket are not linked or used by any one else. If at least one of these resources is linked, then the reference counting is broken somewhere. This warning will be triggered before KASAN will do, and will make it easier to debug initial issue. This works on platforms without KASAN support. Signed-off-by: Oleksij Rempel --- net/can/j1939/main.c | 4 ++++ net/can/j1939/transport.c | 3 +++ 2 files changed, 7 insertions(+) diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c index 2afcf27c72c8..137054bff9ec 100644 --- a/net/can/j1939/main.c +++ b/net/can/j1939/main.c @@ -152,6 +152,10 @@ static void __j1939_priv_release(struct kref *kref) netdev_dbg(priv->ndev, "%s: 0x%p\n", __func__, priv); + WARN_ON_ONCE(!list_empty(&priv->active_session_list)); + WARN_ON_ONCE(!list_empty(&priv->ecus)); + WARN_ON_ONCE(!list_empty(&priv->j1939_socks)); + dev_put(ndev); kfree(priv); } diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c index 0c62b8fc4b20..9f99af5b0b11 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -267,6 +267,9 @@ static void j1939_session_destroy(struct j1939_session *session) netdev_dbg(session->priv->ndev, "%s: 0x%p\n", __func__, session); + WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry)); + WARN_ON_ONCE(!list_empty(&session->active_session_list_entry)); + skb_queue_purge(&session->skb_queue); __j1939_session_drop(session); j1939_priv_put(session->priv); -- 2.24.0