IB/ipoib: Replace list_del of the neigh->list with list_del_init

In order to resolve a situation where a few process delete
the same list element in sequence and cause panic, list_del
is replaced with list_del_init. In this case if the first
process that calls list_del releases the lock before acquiring
it again, other processes who can acquire the lock will call
list_del_init.

Fixes: b63b70d87741 ("IPoIB: Use a private hash table for path lookup")
Signed-off-by: Feras Daoud <ferasda@mellanox.com>
Signed-off-by: Erez Shitrit <erezsh@mellanox.com>
Reviewed-by: Alex Vesker <valex@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Yuval Shaia <yuval.shaia@oracle.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 1086858f1cbfea87eb242ba739e581979a26105a..ee32a2a87e2d274a2bc3861615ec951e73b7d44a 100644 (file)
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -1297,7 +1297,7 @@ static void __ipoib_reap_neigh(struct ipoib_dev_priv *priv)
                                                   rcu_dereference_protected(neigh->hnext,
                                                                             lockdep_is_held(&priv->lock)));
                                /* remove from path/mc list */
-                               list_del(&neigh->list);
+                               list_del_init(&neigh->list);
                                call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                        } else {
                                np = &neigh->hnext;
@@ -1461,7 +1461,7 @@ void ipoib_neigh_free(struct ipoib_neigh *neigh)
                                           rcu_dereference_protected(neigh->hnext,
                                                                     lockdep_is_held(&priv->lock)));
                        /* remove from parent list */
-                       list_del(&neigh->list);
+                       list_del_init(&neigh->list);
                        call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                        return;
                } else {
@@ -1546,7 +1546,7 @@ void ipoib_del_neighs_by_gid(struct net_device *dev, u8 *gid)
                                                   rcu_dereference_protected(neigh->hnext,
                                                                             lockdep_is_held(&priv->lock)));
                                /* remove from parent list */
-                               list_del(&neigh->list);
+                               list_del_init(&neigh->list);
                                call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                        } else {
                                np = &neigh->hnext;
@@ -1588,7 +1588,7 @@ static void ipoib_flush_neighs(struct ipoib_dev_priv *priv)
                                           rcu_dereference_protected(neigh->hnext,
                                                                     lockdep_is_held(&priv->lock)));
                        /* remove from path/mc list */
-                       list_del(&neigh->list);
+                       list_del_init(&neigh->list);
                        call_rcu(&neigh->rcu, ipoib_neigh_reclaim);
                }
        }