From: Kulikov Vasiliy <segooon@gmail.com>
To: Denis Kirjanov <dkirjanov@hera.kernel.org>
Cc: davem@davemloft.net, john.linn@xilinx.com, brian.hill@xilinx.com,
grant.likely@secretlab.ca, jpirko@redhat.com,
netdev@vger.kernel.org
Subject: Re: [PATCH v2 -net-2.6] ll_temac: fix DMA resources leak
Date: Fri, 9 Jul 2010 15:43:47 +0400 [thread overview]
Message-ID: <20100709114347.GA3553@albatros> (raw)
In-Reply-To: <20100708202451.GA4062@hera.kernel.org>
On Thu, Jul 08, 2010 at 20:24 +0000, Denis Kirjanov wrote:
> V2: Check pointers before releasing resources.
>
> Fix DMA resources leak.
> Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
> Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
> ---
> 1 files changed, 32 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/net/ll_temac_main.c b/drivers/net/ll_temac_main.c
> index fa303c8..b57d0ff 100644
> --- a/drivers/net/ll_temac_main.c
> +++ b/drivers/net/ll_temac_main.c
> @@ -193,6 +193,35 @@ static int temac_dcr_setup(struct temac_local *lp, struct of_device *op,
> #endif
>
> /**
> + * * temac_dma_bd_release - Release buffer descriptor rings
> + */
> +static void temac_dma_bd_release(struct net_device *ndev)
> +{
> + struct temac_local *lp = netdev_priv(ndev);
> + int i;
> +
> + for (i = 0; i < RX_BD_NUM; i++) {
> + if (!lp->rx_skb[i])
> + break;
> + else {
> + dma_unmap_single(ndev->dev.parent, lp->rx_bd_v[i].phys,
> + XTE_MAX_JUMBO_FRAME_SIZE, DMA_FROM_DEVICE);
> + dev_kfree_skb(lp->rx_skb[i]);
> + }
> + }
This cycle is needed only if (lp->rx_skb != NULL).
> + if (lp->rx_bd_v)
> + dma_free_coherent(ndev->dev.parent,
> + sizeof(*lp->rx_bd_v) * RX_BD_NUM,
> + lp->rx_bd_v, lp->rx_bd_p);
> + if (lp->tx_bd_v)
> + dma_free_coherent(ndev->dev.parent,
> + sizeof(*lp->tx_bd_v) * TX_BD_NUM,
> + lp->tx_bd_v, lp->tx_bd_p);
After temac_dma_bd_release() lp->rx_bd_v and lp->rx_bd_p are freed but
are nonzero. If lp->rx_skb allocation fails second time then these DMA's
would be freed second time.
lp->tx_bd_v = lp->rx_bd_v = NULL here fixes this.
> + if (lp->rx_skb)
> + kfree(lp->rx_skb);
> +}
> +
> +/**
> * temac_dma_bd_init - Setup buffer descriptor rings
> */
> static int temac_dma_bd_init(struct net_device *ndev)
> @@ -275,6 +304,7 @@ static int temac_dma_bd_init(struct net_device *ndev)
> return 0;
>
> out:
> + temac_dma_bd_release(ndev);
> return -ENOMEM;
> }
>
> @@ -858,6 +888,8 @@ static int temac_stop(struct net_device *ndev)
> phy_disconnect(lp->phy_dev);
> lp->phy_dev = NULL;
>
> + temac_dma_bd_release(ndev);
> +
> return 0;
> }
>
next prev parent reply other threads:[~2010-07-09 11:44 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-08 20:24 [PATCH v2 -net-2.6] ll_temac: fix DMA resources leak Denis Kirjanov
2010-07-09 11:43 ` Kulikov Vasiliy [this message]
2010-07-09 17:59 ` Kulikov Vasiliy
2010-07-09 20:09 ` Denis Kirjanov
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