Re: [PATCH] irda: vlsi_ir: fix check for dma mapping errors

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

Hello!

On 3/25/2017 1:48 AM, Alexey Khoroshilov wrote:

> vlsi_alloc_ring() checks for dma mapping errors by comparison

    DMA. Comparing.

> returned address with zero, while pci_dma_mapping_error() should be used.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
> ---
>  drivers/net/irda/vlsi_ir.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/irda/vlsi_ir.c b/drivers/net/irda/vlsi_ir.c
> index ffedad2a360a..15b920086251 100644
> --- a/drivers/net/irda/vlsi_ir.c
> +++ b/drivers/net/irda/vlsi_ir.c
> @@ -418,8 +418,9 @@ static struct vlsi_ring *vlsi_alloc_ring(struct pci_dev *pdev, struct ring_descr
>  		memset(rd, 0, sizeof(*rd));
>  		rd->hw = hwmap + i;
>  		rd->buf = kmalloc(len, GFP_KERNEL|GFP_DMA);
> -		if (rd->buf == NULL ||
> -		    !(busaddr = pci_map_single(pdev, rd->buf, len, dir))) {
> +		if (rd->buf)
> +			busaddr = pci_map_single(pdev, rd->buf, len, dir);
> +		if (rd->buf == NULL || pci_dma_mapping_error(pdev, busaddr)) {

    '!rd->buf' is preferred in the networking trees.

[...]

MBR, Sergei