Re: [PATCH][next] xsk: Fix null check on error return path

[Björn Töpel]

On 2020-09-02 17:07, Gustavo A. R. Silva wrote:
> Currently, dma_map is being checked, when the right object identifier
> to be null-checked is dma_map->dma_pages, instead.
>
> Fix this by null-checking dma_map->dma_pages.
>
> Addresses-Coverity-ID: 1496811 ("Logically dead code")
> Fixes: 921b68692abb ("xsk: Enable sharing of dma mappings")
> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Nice catch!

Acked-by: Björn Töpel <bjorn.topel@xxxxxxxxx>

> ---
>   net/xdp/xsk_buff_pool.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> index 795d7c81c0ca..5b00bc5707f2 100644
> --- a/net/xdp/xsk_buff_pool.c
> +++ b/net/xdp/xsk_buff_pool.c
> @@ -287,7 +287,7 @@ static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_devi
>   		return NULL;
>   
>   	dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
> -	if (!dma_map) {
> +	if (!dma_map->dma_pages) {
>   		kfree(dma_map);
>   		return NULL;
>   	}