netdev - Re: [net 11/12] net/mlx5e: Revert parameters on errors when changing MTU and LRO state without reset

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CAF=yD-+DGf_PAQzWScXR7O2J5WY2G5maxMbDQQCNbJXYE6R1Mw@mail.gmail.com>
Date:   Wed, 27 Jan 2021 15:00:04 -0500
From:   Willem de Bruijn <willemdebruijn.kernel@...il.com>
To:     Saeed Mahameed <saeedm@...dia.com>
Cc:     Jakub Kicinski <kuba@...nel.org>,
        "David S. Miller" <davem@...emloft.net>,
        Network Development <netdev@...r.kernel.org>,
        Maxim Mikityanskiy <maximmi@...lanox.com>,
        Tariq Toukan <tariqt@...dia.com>
Subject: Re: [net 11/12] net/mlx5e: Revert parameters on errors when changing
 MTU and LRO state without reset

On Wed, Jan 27, 2021 at 3:58 AM Saeed Mahameed <saeedm@...dia.com> wrote:
>
> From: Maxim Mikityanskiy <maximmi@...lanox.com>
>
> Sometimes, channel params are changed without recreating the channels.
> It happens in two basic cases: when the channels are closed, and when
> the parameter being changed doesn't affect how channels are configured.
> Such changes invoke a hardware command that might fail. The whole
> operation should be reverted in such cases, but the code that restores
> the parameters' values in the driver was missing. This commit adds this
> handling.
>
> Fixes: 2e20a151205b ("net/mlx5e: Fail safe mtu and lro setting")
> Signed-off-by: Maxim Mikityanskiy <maximmi@...lanox.com>
> Reviewed-by: Tariq Toukan <tariqt@...dia.com>
> Signed-off-by: Saeed Mahameed <saeedm@...dia.com>
> ---
>  .../net/ethernet/mellanox/mlx5/core/en_main.c | 30 +++++++++++++------
>  1 file changed, 21 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> index ac76d32bad7d..a9d824a9cb05 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
> @@ -3764,7 +3764,7 @@ static int set_feature_lro(struct net_device *netdev, bool enable)
>         struct mlx5e_priv *priv = netdev_priv(netdev);
>         struct mlx5_core_dev *mdev = priv->mdev;
>         struct mlx5e_channels new_channels = {};
> -       struct mlx5e_params *old_params;
> +       struct mlx5e_params *cur_params;
>         int err = 0;
>         bool reset;
>
> @@ -3777,8 +3777,8 @@ static int set_feature_lro(struct net_device *netdev, bool enable)
>                 goto out;
>         }
>
> -       old_params = &priv->channels.params;
> -       if (enable && !MLX5E_GET_PFLAG(old_params, MLX5E_PFLAG_RX_STRIDING_RQ)) {
> +       cur_params = &priv->channels.params;
> +       if (enable && !MLX5E_GET_PFLAG(cur_params, MLX5E_PFLAG_RX_STRIDING_RQ)) {
>                 netdev_warn(netdev, "can't set LRO with legacy RQ\n");
>                 err = -EINVAL;
>                 goto out;
> @@ -3786,18 +3786,23 @@ static int set_feature_lro(struct net_device *netdev, bool enable)
>
>         reset = test_bit(MLX5E_STATE_OPENED, &priv->state);
>
> -       new_channels.params = *old_params;
> +       new_channels.params = *cur_params;
>         new_channels.params.lro_en = enable;
>
> -       if (old_params->rq_wq_type != MLX5_WQ_TYPE_CYCLIC) {
> -               if (mlx5e_rx_mpwqe_is_linear_skb(mdev, old_params, NULL) ==
> +       if (cur_params->rq_wq_type != MLX5_WQ_TYPE_CYCLIC) {
> +               if (mlx5e_rx_mpwqe_is_linear_skb(mdev, cur_params, NULL) ==
>                     mlx5e_rx_mpwqe_is_linear_skb(mdev, &new_channels.params, NULL))
>                         reset = false;
>         }
>
>         if (!reset) {
> -               *old_params = new_channels.params;
> +               struct mlx5e_params old_params;
> +
> +               old_params = *cur_params;
> +               *cur_params = new_channels.params;
>                 err = mlx5e_modify_tirs_lro(priv);
> +               if (err)
> +                       *cur_params = old_params;

No need to explicitly save and restore all params if the only one
changed is lro_en?