Re: [PATCH] drm/panthor: validate group queue count

[Steven Price <steven.price@arm.com>]

On 02/09/2025 20:20, Chia-I Wu wrote:
> A panthor group can have at most MAX_CS_PER_CSG panthor queues.
> 
> Signed-off-by: Chia-I Wu <olvaffe@gmail.com>

Good catch - that's a nasty bug.

I think this should have:

Fixes: de8548813824 ("drm/panthor: Add the scheduler logical block")

> ---
>  drivers/gpu/drm/panthor/panthor_sched.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/panthor/panthor_sched.c b/drivers/gpu/drm/panthor/panthor_sched.c
> index ba5dc3e443d9c..249ab889ca91f 100644
> --- a/drivers/gpu/drm/panthor/panthor_sched.c
> +++ b/drivers/gpu/drm/panthor/panthor_sched.c
> @@ -3473,6 +3473,9 @@ int panthor_group_create(struct panthor_file *pfile,
>  	    hweight64(group_args->tiler_core_mask) < group_args->max_tiler_cores)
>  		return -EINVAL;
>  
> +	if (group_args->queues.count > MAX_CS_PER_CSG)
> +		return -EINVAL;
> +

I think this check would be better moved up to
panthor_ioctl_group_create() (where we already have a zero check). But
either way:

Reviewed-by: Steven Price <steven.price@arm.com>

Thanks,
Steve

>  	group = kzalloc(sizeof(*group), GFP_KERNEL);
>  	if (!group)
>  		return -ENOMEM;