net/mlx5e: Properly access RCU protected qdisc_sleeping variable

qdisc_sleeping variable is declared as "struct Qdisc __rcu" and
as such needs proper annotation while accessing it.

Without rtnl_dereference(), the following error is generated by sparse:

drivers/net/ethernet/mellanox/mlx5/core/en/qos.c:377:40: warning:
  incorrect type in initializer (different address spaces)
drivers/net/ethernet/mellanox/mlx5/core/en/qos.c:377:40:    expected
  struct Qdisc *qdisc
drivers/net/ethernet/mellanox/mlx5/core/en/qos.c:377:40:    got struct
  Qdisc [noderef] __rcu *qdisc_sleeping

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Link: https://patch.msgid.link/1752675472-201445-4-git-send-email-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
index f0744a45db92c3e722eb4d5fab78bc73fb4b3eb5..4e461cb03b83dd855a33dc771793449c2528e92a 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
@@ -374,7 +374,7 @@ void mlx5e_reactivate_qos_sq(struct mlx5e_priv *priv, u16 qid, struct netdev_que
 void mlx5e_reset_qdisc(struct net_device *dev, u16 qid)
 {
        struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, qid);
-       struct Qdisc *qdisc = dev_queue->qdisc_sleeping;
+       struct Qdisc *qdisc = rtnl_dereference(dev_queue->qdisc_sleeping);
 
        if (!qdisc)
                return;