On Thu, May 10, 2018 at 09:02:26AM +0200, Christophe JAILLET wrote:
> If an error occurs, 'mlx4_en_destroy_netdev()' is called.
> It then calls 'mlx4_en_free_resources()' which does the needed resources
> cleanup.
>
> So, doing some explicit kfree in the error handling path would lead to
> some double kfree.
Patch make sense but what's bothering me is that mlx4_en_free_resources
loops on the entire array, assuming !priv->tx_ring[t] means entry is
allocated but the existing code does not assume that, see [1]. So i looked
to see where tx_ring array is zeroed and didn't find it.
Am i missing something here.
>
> Simplify code to avoid such a case.
>
> Fixes: 67f8b1dcb9ee ("net/mlx4_en: Refactor the XDP forwarding rings scheme")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> drivers/net/ethernet/mellanox/mlx4/en_netdev.c | 8 +-------
> 1 file changed, 1 insertion(+), 7 deletions(-)
>
> diff --git a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> index e0adac4a9a19..9670b33fc9b1 100644
> --- a/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> +++ b/drivers/net/ethernet/mellanox/mlx4/en_netdev.c
> @@ -3324,12 +3324,11 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
> MAX_TX_RINGS, GFP_KERNEL);
> if (!priv->tx_ring[t]) {
> err = -ENOMEM;
> - goto err_free_tx;
> + goto out;
> }
> priv->tx_cq[t] = kzalloc(sizeof(struct mlx4_en_cq *) *
> MAX_TX_RINGS, GFP_KERNEL);
> if (!priv->tx_cq[t]) {
> - kfree(priv->tx_ring[t]);
> err = -ENOMEM;
> goto out;
> }
> @@ -3582,11 +3581,6 @@ int mlx4_en_init_netdev(struct mlx4_en_dev *mdev, int port,
>
> return 0;
>
> -err_free_tx:
> - while (t--) {
[1]
> - kfree(priv->tx_ring[t]);
> - kfree(priv->tx_cq[t]);
> - }
> out:
> mlx4_en_destroy_netdev(dev);
> return err;
> --
> 2.17.0
>
> --
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