Re: [PATCH] atm: eni: Add check for dma_map_single

[Jakub Kicinski]

On Fri, 11 Mar 2022 15:16:56 +0800 Jiasheng Jiang wrote:
> As the potential failure of the dma_map_single(),
> it should be better to check it and return error
> if fails.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
> ---
>  drivers/atm/eni.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/atm/eni.c b/drivers/atm/eni.c
> index 422753d52244..96c2d8f5646b 100644
> --- a/drivers/atm/eni.c
> +++ b/drivers/atm/eni.c
> @@ -1112,6 +1112,8 @@ DPRINTK("iovcnt = %d\n",skb_shinfo(skb)->nr_frags);
>  	skb_data3 = skb->data[3];
>  	paddr = dma_map_single(&eni_dev->pci_dev->dev,skb->data,skb->len,
>  			       DMA_TO_DEVICE);
> +	if (dma_mapping_error(&eni_dev->pci_dev->dev, paddr))
> +		return enq_jam;

Probably better to drop the packet if mapping fails.

>  	ENI_PRV_PADDR(skb) = paddr;
>  	/* prepare DMA queue entries */
>  	j = 0;