iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

net/mlx5e: Fix division by 0 in mlx5e_select_queue

Browse Source 
mlx5e_select_queue compares num_tc_x_num_ch to real_num_tx_queues to
determine if HTB and/or PTP offloads are active. If they are, it
calculates netdev_pick_tx() % num_tc_x_num_ch to prevent it from
selecting HTB and PTP queues for regular traffic. However, before the
channels are first activated, num_tc_x_num_ch is zero. If
ndo_select_queue gets called at this point, the HTB/PTP check will pass,
and mlx5e_select_queue will attempt to take a modulo by num_tc_x_num_ch,
which equals to zero.

This commit fixes the bug by assigning num_tc_x_num_ch to a non-zero
value before registering the netdev.

Fixes: 214baf22870c ("net/mlx5e: Support HTB offload")
Reported-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
This commit is contained in:
Maxim Mikityanskiy 2021-03-01 20:59:59 +02:00 committed by Saeed Mahameed
parent 4eacfe72e3
commit 846d6da1fc
1 changed files with 5 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/net/ethernet/mellanox/mlx5/core/en_main.c
View File

@ -4979,6 +4979,11 @@ void mlx5e_build_nic_params(struct mlx5e_priv *priv, struct mlx5e_xsk *xsk, u16
priv->max_nch);
params->num_tc = 1;
/* Set an initial non-zero value, so that mlx5e_select_queue won't
* divide by zero if called before first activating channels.
*/
priv->num_tc_x_num_ch = params->num_channels * params->num_tc;
/* SQ */
params->log_sq_size = is_kdump_kernel() ?
MLX5E_PARAMS_MINIMUM_LOG_SQ_SIZE :