On 06.06.23 19:11, Laurent Pinchart wrote:
> When commit 716c330433e3 ("media: uvcvideo: Use standard names for
> menus") reworked the handling of menu controls, it inadvertently
> replaced a GENMASK(n - 1, 0) with a BIT_MASK(n). The latter isn't
> equivalent to the former, which broke adding XU mappings from userspace.
> Fix it.
>
> Reported-by: Poncho <poncho@xxxxxxxxx>
> Link: https://lore.kernel.org/linux-media/468a36ec-c3ac-cb47-e12f-5906239ae3cd@xxxxxxxxx/
> Fixes: 716c330433e3 ("media: uvcvideo: Use standard names for menus")
Many thx for looking into this. Please consider adding
Cc: stable@xxxxxxxxxxxxxxx
to get this fixed in 6.3.y, as a fixes tag alone is not enough to
guarantee a backport attempt by the stable team.
Ciao, Thorsten
> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> ---
> This is untested. Poncho, would you be able to test this patch to see if
> it fixes your issue ?
> ---
> drivers/media/usb/uvc/uvc_v4l2.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index 5ac2a424b13d..f4988f03640a 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -45,7 +45,7 @@ static int uvc_control_add_xu_mapping(struct uvc_video_chain *chain,
> map->menu_names = NULL;
> map->menu_mapping = NULL;
>
> - map->menu_mask = BIT_MASK(xmap->menu_count);
> + map->menu_mask = GENMASK(xmap->menu_count - 1, 0);
>
> size = xmap->menu_count * sizeof(*map->menu_mapping);
> map->menu_mapping = kzalloc(size, GFP_KERNEL);
