On Sat, Oct 07, 2023 at 01:13:09PM +0200, Christophe JAILLET wrote:
> If pxad_alloc_desc() fails on the first dma_pool_alloc() call, then
> sw_desc->nb_desc is zero.
> In such a case pxad_free_desc() is called and it will BUG_ON().
>
> Remove this erroneous BUG_ON().
Perhaps it could be changed to a WARN_ON()?
> It is also useless, because if "sw_desc->nb_desc == 0", then, on the first
> iteration of the for loop, i is -1 and the loop will not be executed.
> (both i and sw_desc->nb_desc are 'int')
Agreed.
>
> Fixes: a57e16cf0333 ("dmaengine: pxa: add pxa dmaengine driver")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> drivers/dma/pxa_dma.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c
> index 3c574dc0613b..94cef2905940 100644
> --- a/drivers/dma/pxa_dma.c
> +++ b/drivers/dma/pxa_dma.c
> @@ -722,7 +722,6 @@ static void pxad_free_desc(struct virt_dma_desc *vd)
> dma_addr_t dma;
> struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd);
>
> - BUG_ON(sw_desc->nb_desc == 0);
> for (i = sw_desc->nb_desc - 1; i >= 0; i--) {
> if (i > 0)
> dma = sw_desc->hw_desc[i - 1]->ddadr;
> --
> 2.34.1
>
--
Kees Cook
