Re: [PATCH] accel/qaic: Replace user defined overflow check

["Falkowski, Maciej" <maciej.falkowski@linux.intel.com>]

Reviewed-by: Maciej Falkowski <maciej.falkowski@linux.intel.com>

On 10/15/2025 5:22 PM, Youssef Samir wrote:
> From: Sourab Bera <quic_sourbera@quicinc.com>
>
> Replace the current logic to check overflow, with the kernel-provided
> macro `check_mul_overflow` in the function __qaic_execute_bo_ioctl().
>
> Signed-off-by: Sourab Bera <quic_sourbera@quicinc.com>
> Signed-off-by: Youssef Samir <youssef.abdulrahman@oss.qualcomm.com>
> ---
>   drivers/accel/qaic/qaic_data.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/accel/qaic/qaic_data.c b/drivers/accel/qaic/qaic_data.c
> index 797289e9d780..e6f96dbb3382 100644
> --- a/drivers/accel/qaic/qaic_data.c
> +++ b/drivers/accel/qaic/qaic_data.c
> @@ -15,6 +15,7 @@
>   #include <linux/math64.h>
>   #include <linux/mm.h>
>   #include <linux/moduleparam.h>
> +#include <linux/overflow.h>
>   #include <linux/scatterlist.h>
>   #include <linux/spinlock.h>
>   #include <linux/srcu.h>
> @@ -1305,17 +1306,17 @@ static int __qaic_execute_bo_ioctl(struct drm_device *dev, void *data, struct dr
>   	u64 received_ts;
>   	u32 queue_level;
>   	u64 submit_ts;
> +	size_t size;
>   	int rcu_id;
>   	u32 head;
>   	u32 tail;
> -	u64 size;
>   	int ret;
>   
>   	received_ts = ktime_get_ns();
>   
>   	size = is_partial ? sizeof(struct qaic_partial_execute_entry) : sizeof(*exec);
> -	n = (unsigned long)size * args->hdr.count;
> -	if (args->hdr.count == 0 || n / args->hdr.count != size)
> +	if (args->hdr.count == 0 ||
> +	    check_mul_overflow((unsigned long)size, (unsigned long)args->hdr.count, &n))
>   		return -EINVAL;
>   
>   	user_data = u64_to_user_ptr(args->data);