On 05/07/2018 03:40 AM, Wei Yongjun wrote:
> platform_get_resource() may fail and return NULL, so we should
> better check it's return value to avoid a NULL pointer dereference
> a bit later in the code.
>
> This is detected by Coccinelle semantic patch.
>
> @@
> expression pdev, res, n, t, e, e1, e2;
> @@
>
> res = platform_get_resource(pdev, t, n);
> + if (!res)
> + return -EINVAL;
> ... when != res == NULL
> e = devm_ioremap_nocache(e1, res->start, e2);
>
> Fixes: 9b3b8171f7f4 ("dmaengine: sprd: Add Spreadtrum DMA driver")
> Signed-off-by: Wei Yongjun <weiyongjun1@xxxxxxxxxx>
> ---
> drivers/dma/sprd-dma.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/drivers/dma/sprd-dma.c b/drivers/dma/sprd-dma.c
> index ccdeb8f..dba7a17 100644
> --- a/drivers/dma/sprd-dma.c
> +++ b/drivers/dma/sprd-dma.c
> @@ -807,6 +807,8 @@ static int sprd_dma_probe(struct platform_device *pdev)
> }
>
> res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (!res)
> + return -EINVAL;
> sdev->glb_base = devm_ioremap_nocache(&pdev->dev, res->start,
> resource_size(res));
I think a better improvement would be to replace this with
devm_ioremap_resource() which has the NULL pointer check and some other
things built-in.
--
To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
