Hi Prabhakar,
On Wed, Jan 10, 2024 at 11:27 PM Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> The max channel count for RZ DMAC is 16, hence use u8 instead of unsigned
> int and make the pdev_irqname string long enough to avoid the warning.
Note that the danger lies into someone changing
RZ_DMAC_MAX_CHANNELS later...
> This fixes the below issue:
> drivers/dma/sh/rz-dmac.c: In function ‘rz_dmac_probe’:
> drivers/dma/sh/rz-dmac.c:770:34: warning: ‘%u’ directive writing between 1 and 10 bytes into a region of size 3 [-Wformat-overflow=]
> 770 | sprintf(pdev_irqname, "ch%u", index);
> | ^~
> In function ‘rz_dmac_chan_probe’,
> inlined from ‘rz_dmac_probe’ at drivers/dma/sh/rz-dmac.c:910:9:
> drivers/dma/sh/rz-dmac.c:770:31: note: directive argument in the range [0, 4294967294]
> 770 | sprintf(pdev_irqname, "ch%u", index);
> | ^~~~~~
> drivers/dma/sh/rz-dmac.c:770:9: note: ‘sprintf’ output between 4 and 13 bytes into a destination of size 5
> 770 | sprintf(pdev_irqname, "ch%u", index);
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> While at it use scnprintf() instead of sprintf() to make the code
> more robust.
>
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Some nits below...
> --- a/drivers/dma/sh/rz-dmac.c
> +++ b/drivers/dma/sh/rz-dmac.c
> @@ -845,9 +845,9 @@ static int rz_dmac_probe(struct platform_device *pdev)
> struct dma_device *engine;
> struct rz_dmac *dmac;
> int channel_num;
> - unsigned int i;
> int ret;
> int irq;
> + u8 i;
Personally, I'm not much a fan of making loop counters smaller than
(unsigned) int. If you do go this way, you should change channel_num
to u8, too, just like i in rz_dmac_remove().
>
> dmac = devm_kzalloc(&pdev->dev, sizeof(*dmac), GFP_KERNEL);
> if (!dmac)
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
