[SRU][N:linux-bluefield][PATCH v1 5/5] net/mlx5e: Properly access RCU protected qdisc_sleeping variable

[Stav Aviram]

From: Leon Romanovsky <leonro at nvidia.com>

BugLink: https://bugs.launchpad.net/bugs/2126876

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 at nvidia.com>
Signed-off-by: Tariq Toukan <tariqt at nvidia.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski at linux.intel.com>
Link: https://patch.msgid.link/1752675472-201445-4-git-send-email-tariqt@nvidia.com
Signed-off-by: Jakub Kicinski <kuba at kernel.org>
(cherry picked from commit 2a601b2d35623065d31ebaf697b07502d54878c9)
Signed-off-by: Stav Aviram <saviram at nvidia.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/qos.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
index 922bc5b7c10e..a1bffe756a90 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/qos.c
@@ -365,7 +365,7 @@ 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;
-- 
2.38.1