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

From: Greg KH
Date: Wed Mar 08 2017 - 05:11:58 EST

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.


greg k-h