On Mon, Jan 29, 2018 at 11:02:56AM +0100, Hans Verkuil wrote: > On 01/29/2018 10:56 AM, Sakari Ailus wrote: > > Hi Hans, > > > > On Fri, Jan 26, 2018 at 01:43:26PM +0100, Hans Verkuil wrote: > >> From: Hans Verkuil <hans.verkuil@xxxxxxxxx> > >> > >> Some ioctls need to copy back the result even if the ioctl returned > >> an error. However, don't do this for the error codes -ENOTTY, -EFAULT > >> and -ENOIOCTLCMD. It makes no sense in those cases. > >> > >> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > > > Acked-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx> > > > > Shouldn't such a change be made to video_usercopy() as well? Doesn't need > > to be in this set though. > > Good point. I'll add that for v2. This is not actually a bug as such, but > it's just weird to copy back results if the ioctl wasn't implemented at all. > > I realize that I need to drop the -EFAULT check: if you call VIDIOC_G_EXT_CTRLS > with an incorrect userspace buffer for the payload, then the control framework > will set error_idx to the index of the control with the wrong buffer. So you do > need to copy back the data in case of -EFAULT. > > I can also drop -ENOIOCTLCMD since video_usercopy() converts that to -ENOTTY. Agreed. -- Sakari Ailus e-mail: sakari.ailus@xxxxxx
