Re: [PATCH] dmaengine: ti: Fix a potential under memory allocation issue in edma_setup_from_hw()

[Péter Ujfalusi]

On 21/05/2022 20:26, Christophe JAILLET wrote:
> If the 'queue_priority_mapping' is not provided, we need to allocate the
> correct amount of memory. Each entry takes 2 s8, so actually less memory
> than needed is allocated.
> 
> Update the size of each entry when the memory is devm_kcalloc'ed.

Good catch, obviously this has not been hit for almost a decade :o

Acked-by: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx>

> 
> Fixes: 6d10c3950bf4 ("ARM: edma: Get IP configuration from HW (number of channels, tc, etc)")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
> ---
> Note that the devm_kcalloc() in edma_xbar_event_map() looks also spurious.
> However, this looks fine to me because of the 'nelm >>= 1;' before the
> 'for' loop.
> ---
>  drivers/dma/ti/edma.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/ti/edma.c b/drivers/dma/ti/edma.c
> index 3ea8ef7f57df..f313e2cf542c 100644
> --- a/drivers/dma/ti/edma.c
> +++ b/drivers/dma/ti/edma.c
> @@ -2121,7 +2121,7 @@ static int edma_setup_from_hw(struct device *dev, struct edma_soc_info *pdata,
>  	 * priority. So Q0 is the highest priority queue and the last queue has
>  	 * the lowest priority.
>  	 */
> -	queue_priority_map = devm_kcalloc(dev, ecc->num_tc + 1, sizeof(s8),
> +	queue_priority_map = devm_kcalloc(dev, ecc->num_tc + 1, sizeof(s8) * 2,
>  					  GFP_KERNEL);
>  	if (!queue_priority_map)
>  		return -ENOMEM;

-- 
Péter