[PATCH] [bionic] net/mlx5e: Don't attempt to dereference the ppriv struct if not being eswitch manager

[Talat Batheesh]

From: Or Gerlitz <ogerlitz at mellanox.com>

BugLink:  http://bugs.launchpad.net/bugs/1799049

The check for cpu hit statistics was not returning immediate false for
any non vport rep netdev and hence we crashed (say on mlx5 probed VFs) if
user-space tool was calling into any possible netdev in the system.

Fix that by doing a proper check before dereferencing.

Fixes: 1d447a39142e ('net/mlx5e: Extendable vport representor netdev private data')
Signed-off-by: Or Gerlitz <ogerlitz at mellanox.com>
Reported-by: Eli Cohen <eli at melloanox.com>
Reviewed-by: Eli Cohen <eli at melloanox.com>
Signed-off-by: Saeed Mahameed <saeedm at mellanox.com>
(cherry picked from commit 8ffd569aaa818f2624ca821d9a246342fa8b8c50)
Signed-off-by: Talat Batheesh <talatb at mellanox.com>
---
 drivers/net/ethernet/mellanox/mlx5/core/en_rep.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
index f72abdeb6d08..9ebe78ec99f0 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_rep.c
@@ -750,8 +750,12 @@ bool mlx5e_is_uplink_rep(struct mlx5e_priv *priv)
 static bool mlx5e_is_vf_vport_rep(struct mlx5e_priv *priv)
 {
 	struct mlx5e_rep_priv *rpriv = priv->ppriv;
-	struct mlx5_eswitch_rep *rep = rpriv->rep;
+	struct mlx5_eswitch_rep *rep;
 
+	if (!MLX5_CAP_GEN(priv->mdev, eswitch_flow_table))
+		return false;
+
+	rep = rpriv->rep;
 	if (rep && rep->vport != FDB_UPLINK_VPORT)
 		return true;
 
-- 
2.7.5