Re: [PATCH] net: mellanox: mlx5: fix error return code of mlx5e_stats_flower()

[Roi Dayan <roid@nvidia.com>]

On 2021-03-06 3:47 PM, Jia-Ju Bai wrote:
> When mlx5e_tc_get_counter() returns NULL to counter or
> mlx5_devcom_get_peer_data() returns NULL to peer_esw, no error return
> code of mlx5e_stats_flower() is assigned.
> To fix this bug, err is assigned with -EINVAL in these cases.
> 
> Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
> Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
> ---
>   drivers/net/ethernet/mellanox/mlx5/core/en_tc.c | 12 +++++++++---
>   1 file changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> index 0da69b98f38f..1f2c9da7bd35 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c
> @@ -4380,8 +4380,10 @@ int mlx5e_stats_flower(struct net_device *dev, struct mlx5e_priv *priv,
>   
>   	if (mlx5e_is_offloaded_flow(flow) || flow_flag_test(flow, CT)) {
>   		counter = mlx5e_tc_get_counter(flow);
> -		if (!counter)
> +		if (!counter) {
> +			err = -EINVAL;
>   			goto errout;
> +		}
>   
>   		mlx5_fc_query_cached(counter, &bytes, &packets, &lastuse);
>   	}
> @@ -4390,8 +4392,10 @@ int mlx5e_stats_flower(struct net_device *dev, struct mlx5e_priv *priv,
>   	 * un-offloaded while the other rule is offloaded.
>   	 */
>   	peer_esw = mlx5_devcom_get_peer_data(devcom, MLX5_DEVCOM_ESW_OFFLOADS);
> -	if (!peer_esw)
> +	if (!peer_esw) {
> +		err = -EINVAL;

note here it's not an error. it could be there is no peer esw
so just continue with the stats update.

>   		goto out;
> +	}
>   
>   	if (flow_flag_test(flow, DUP) &&
>   	    flow_flag_test(flow->peer_flow, OFFLOADED)) {
> @@ -4400,8 +4404,10 @@ int mlx5e_stats_flower(struct net_device *dev, struct mlx5e_priv *priv,
>   		u64 lastuse2;
>   
>   		counter = mlx5e_tc_get_counter(flow->peer_flow);
> -		if (!counter)
> +		if (!counter) {
> +			err = -EINVAL;
>   			goto no_peer_counter;
> +		}
>   		mlx5_fc_query_cached(counter, &bytes2, &packets2, &lastuse2);
>   
>   		bytes += bytes2;
>