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Message-ID: <1f7277fc-8634-94ff-0fe6-6fd087d8e588@gmail.com>
Date:   Sat, 28 May 2022 12:28:50 +0300
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Subject: Re: [PATCH] dmaengine: ti: Fix a potential under memory allocation
 issue in edma_setup_from_hw()
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To:     Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        dan.carpenter@oracle.com, Vinod Koul <vkoul@kernel.org>,
        Joel Fernandes <joelf@ti.com>, Sekhar Nori <nsekhar@ti.com>
Cc:     linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org,
        Peter Ujfalusi <peter.ujfalusi@ti.com>,
        dmaengine@vger.kernel.org
References: <8c95c485be294e64457606089a2a56e68e2ebd1a.1653153959.git.christophe.jaillet@wanadoo.fr>
From:   =?UTF-8?Q?P=c3=a9ter_Ujfalusi?= <peter.ujfalusi@gmail.com>
In-Reply-To: <8c95c485be294e64457606089a2a56e68e2ebd1a.1653153959.git.christophe.jaillet@wanadoo.fr>
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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@gmail.com>

> 
> Fixes: 6d10c3950bf4 ("ARM: edma: Get IP configuration from HW (number of channels, tc, etc)")
> Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
> ---
> 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;

-- 
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