Re: [PATCH net v3 3/3] net: rswitch: Fix missing dev_kfree_skb_any() in error path

From: Wojciech Drewek <wojciech.drewek@intel.com>
To: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>,
	<s.shtylyov@omp.ru>, <davem@davemloft.net>, <edumazet@google.com>,
	<kuba@kernel.org>, <pabeni@redhat.com>
Cc: <netdev@vger.kernel.org>, <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH net v3 3/3] net: rswitch: Fix missing dev_kfree_skb_any() in error path
Date: Wed, 22 Nov 2023 11:17:31 +0100	[thread overview]
Message-ID: <1bbfaa5e-b9b9-4986-846f-6292a6b36ccd@intel.com> (raw)
In-Reply-To: <20231122051143.3660780-4-yoshihiro.shimoda.uh@renesas.com>


On 22.11.2023 06:11, Yoshihiro Shimoda wrote:
> Before returning the rswitch_start_xmit() in the error path,
> dev_kfree_skb_any() should be called. So, fix it.
> 
> Fixes: 33f5d733b589 ("net: renesas: rswitch: Improve TX timestamp accuracy")
> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
> ---

Nice cleanup
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>

>  drivers/net/ethernet/renesas/rswitch.c | 20 ++++++++++++--------
>  1 file changed, 12 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/ethernet/renesas/rswitch.c b/drivers/net/ethernet/renesas/rswitch.c
> index 45bf9808c143..e77c6ff93d81 100644
> --- a/drivers/net/ethernet/renesas/rswitch.c
> +++ b/drivers/net/ethernet/renesas/rswitch.c
> @@ -1517,10 +1517,8 @@ static netdev_tx_t rswitch_start_xmit(struct sk_buff *skb, struct net_device *nd
>  		return ret;
>  
>  	dma_addr = dma_map_single(ndev->dev.parent, skb->data, skb->len, DMA_TO_DEVICE);
> -	if (dma_mapping_error(ndev->dev.parent, dma_addr)) {
> -		dev_kfree_skb_any(skb);
> -		return ret;
> -	}
> +	if (dma_mapping_error(ndev->dev.parent, dma_addr))
> +		goto err_kfree;
>  
>  	gq->skbs[gq->cur] = skb;
>  	desc = &gq->tx_ring[gq->cur];
> @@ -1533,10 +1531,8 @@ static netdev_tx_t rswitch_start_xmit(struct sk_buff *skb, struct net_device *nd
>  		struct rswitch_gwca_ts_info *ts_info;
>  
>  		ts_info = kzalloc(sizeof(*ts_info), GFP_ATOMIC);
> -		if (!ts_info) {
> -			dma_unmap_single(ndev->dev.parent, dma_addr, skb->len, DMA_TO_DEVICE);
> -			return ret;
> -		}
> +		if (!ts_info)
> +			goto err_unmap;
>  
>  		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
>  		rdev->ts_tag++;
> @@ -1558,6 +1554,14 @@ static netdev_tx_t rswitch_start_xmit(struct sk_buff *skb, struct net_device *nd
>  	gq->cur = rswitch_next_queue_index(gq, true, 1);
>  	rswitch_modify(rdev->addr, GWTRC(gq->index), 0, BIT(gq->index % 32));
>  
> +	return ret;
> +
> +err_unmap:
> +	dma_unmap_single(ndev->dev.parent, dma_addr, skb->len, DMA_TO_DEVICE);
> +
> +err_kfree:
> +	dev_kfree_skb_any(skb);
> +
>  	return ret;
>  }
>