From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935644AbeEJNiW (ORCPT ); Thu, 10 May 2018 09:38:22 -0400 Received: from aserp2120.oracle.com ([141.146.126.78]:36314 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935499AbeEJNiU (ORCPT ); Thu, 10 May 2018 09:38:20 -0400 Date: Thu, 10 May 2018 16:38:08 +0300 From: Yuval Shaia To: Christophe JAILLET Cc: davem@davemloft.net, tariqt@mellanox.com, netdev@vger.kernel.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: Re: [PATCH] net/mlx4_en: Fix an error handling path in 'mlx4_en_init_netdev()' Message-ID: <20180510133808.GA10943@lap1> References: <20180510070226.19575-1-christophe.jaillet@wanadoo.fr> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180510070226.19575-1-christophe.jaillet@wanadoo.fr> User-Agent: Mutt/1.9.2 (2017-12-15) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8888 signatures=668698 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=9 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=993 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1805100132 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > --- > 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html