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Subject: Re: [PATCH 23/26] media: staging: imgu: use array_size
To:     Julia Lawall <Julia.Lawall@inria.fr>,
        Sakari Ailus <sakari.ailus@linux.intel.com>
Cc:     keescook@chromium.org, kernel-janitors@vger.kernel.org,
        Bingbu Cao <bingbu.cao@intel.com>,
        Tianshu Qiu <tian.shu.qiu@intel.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-media@vger.kernel.org, linux-staging@lists.linux.dev,
        linux-kernel@vger.kernel.org
References: <20230623211457.102544-1-Julia.Lawall@inria.fr>
 <20230623211457.102544-24-Julia.Lawall@inria.fr>
From:   Bingbu Cao <bingbu.cao@linux.intel.com>
Message-ID: <778fdf52-9e87-cacd-94a3-cd42554587c5@linux.intel.com>
Date:   Sun, 25 Jun 2023 12:59:14 +0800
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Julia,

Thanks for your patch.

On 6/24/23 5:14 AM, Julia Lawall wrote:
> Use array_size to protect against multiplication overflows.
> 
> The changes were done using the following Coccinelle semantic patch:
> 
> // <smpl>
> @@
>     expression E1, E2;
>     constant C1, C2;
>     identifier alloc = {vmalloc,vzalloc};
> @@
>     
> (
>       alloc(C1 * C2,...)
> |
>       alloc(
> -           (E1) * (E2)
> +           array_size(E1, E2)
>       ,...)
> )
> // </smpl>
> 
> Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
> 
> ---
>  drivers/staging/media/ipu3/ipu3-mmu.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/media/ipu3/ipu3-mmu.c b/drivers/staging/media/ipu3/ipu3-mmu.c
> index cb9bf5fb29a5..9c4adb815c94 100644
> --- a/drivers/staging/media/ipu3/ipu3-mmu.c
> +++ b/drivers/staging/media/ipu3/ipu3-mmu.c
> @@ -464,7 +464,7 @@ struct imgu_mmu_info *imgu_mmu_init(struct device *parent, void __iomem *base)
>  	 * Allocate the array of L2PT CPU pointers, initialized to zero,
>  	 * which means the dummy L2PT allocated above.
>  	 */
> -	mmu->l2pts = vzalloc(IPU3_PT_PTES * sizeof(*mmu->l2pts));
> +	mmu->l2pts = vzalloc(array_size(IPU3_PT_PTES, sizeof(*mmu->l2pts)));
>  	if (!mmu->l2pts)
>  		goto fail_l2pt;
>  
>

Reviewed-by: Bingbu Cao <bingbu.cao@intel.com>


-- 
Best regards,
Bingbu Cao