From 0b1b12f2365b19b9150fcb285e0d0e466a27b5cb Mon Sep 17 00:00:00 2001
From: Bodong Wang <bodong@mellanox.com>
Date: Fri, 13 Sep 2019 16:24:19 -0500
Subject: [PATCH 4/5] net/mlx5: E-Switch, Hold mutex when querying drop counter
in legacy mode
Git-commit: 14c844cbf3503076de6e2e48d575216f1600b19f
Patch-mainline: v5.7-rc1
References: git-fixes
Consider scenario below, CPU 1 is at risk to query already destroyed
drop counters. Need to apply the same state mutex when disabling vport.
+-------------------------------+-------------------------------------+
| CPU 0 | CPU 1 |
+-------------------------------+-------------------------------------+
| mlx5_device_disable_sriov | mlx5e_get_vf_stats |
| mlx5_eswitch_disable | mlx5_eswitch_get_vport_stats |
| esw_disable_vport | mlx5_eswitch_query_vport_drop_stats |
| mlx5_fc_destroy(drop_counter) | mlx5_fc_query(drop_counter) |
+-------------------------------+-------------------------------------+
Fixes: b8a0dbe3a90b ("net/mlx5e: E-switch, Add steering drop counters")
Signed-off-by: Bodong Wang <bodong@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
drivers/net/ethernet/mellanox/mlx5/core/eswitch.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
index e91f79fde3ce..114b1998f2bd 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
@@ -2107,9 +2107,13 @@ static int mlx5_eswitch_query_vport_drop_stats(struct mlx5_core_dev *dev,
u64 bytes = 0;
int err = 0;
- if (!vport->enabled || esw->mode != SRIOV_LEGACY)
+ if (esw->mode != SRIOV_LEGACY)
return 0;
+ mutex_lock(&esw->state_lock);
+ if (!vport->enabled)
+ goto unlock;
+
if (vport->egress.drop_counter)
mlx5_fc_query(dev, vport->egress.drop_counter,
&stats->rx_dropped, &bytes);
@@ -2120,20 +2124,22 @@ static int mlx5_eswitch_query_vport_drop_stats(struct mlx5_core_dev *dev,
if (!MLX5_CAP_GEN(dev, receive_discard_vport_down) &&
!MLX5_CAP_GEN(dev, transmit_discard_vport_down))
- return 0;
+ goto unlock;
err = mlx5_query_vport_down_stats(dev, vport_idx,
&rx_discard_vport_down,
&tx_discard_vport_down);
if (err)
- return err;
+ goto unlock;
if (MLX5_CAP_GEN(dev, receive_discard_vport_down))
stats->rx_dropped += rx_discard_vport_down;
if (MLX5_CAP_GEN(dev, transmit_discard_vport_down))
stats->tx_dropped += tx_discard_vport_down;
- return 0;
+unlock:
+ mutex_unlock(&esw->state_lock);
+ return err;
}
int mlx5_eswitch_get_vport_stats(struct mlx5_eswitch *esw,
--
2.16.4