Re: [PATCH 1/2] Staging: comedi: comedi_fops: Change comedi_num_legacy_minors type

Cheah Kok Cheong
2017-03-08T10:16:40Z

On Wed, Mar 08, 2017 at 10:45:26AM +0100, Greg KH wrote:
> On Wed, Mar 08, 2017 at 05:38:12PM +0800, Cheah Kok Cheong wrote:
> > Dear Greg,
> > Thanks for taking the time to review.
> >
> > On Tue, Mar 07, 2017 at 08:01:38PM +0100, Greg KH wrote:
> > > On Sun, Mar 05, 2017 at 03:22:32AM +0800, Cheah Kok Cheong wrote:
> > > > Change to unsigned to allow removal of negative value check in
> > > > init section.
> > >
> > > Why?
> > >
> >
> > User can input a -ve number as parameter for module loading.
>
> Then they are foolish to do so :)
>
> > This will be caught by the mentioned check and cause loading to fail.
> > I think the original intention here is to inform user via kernel log
> > the acceptable input range.
>
> Either is fine.
>
> > Now if a user doesn't know how to access the log, it's of no help.
>
> They know how to set a module parameter as root but do not know of the
> kernel log? That's trying a bit too hard :)
>
> > If a user does know how to access the log, probably also know how
> > to use modinfo or know that reserving a -ve number of minors is
> > not acceptable.
> >
> > IMHO, this check is pointless and best enforced in module_param.
>
> Ok, but it's really a minor, or no, real issue at all here.
>

I agree with you and that's why I mentioned it's not worth doing
unless there's concurrent work in this area.

Thanks.
Brgds,
CheahKC

> thanks,
>
> greg k-h