Re: [PATCH 2/4] Input: introduce ABS_MAX2/CNT2 and friends

From: Peter Hutterer
Date: Wed Dec 18 2013 - 18:52:34 EST


On Wed, Dec 18, 2013 at 03:48:37PM -0800, Dmitry Torokhov wrote:
> On Thursday, December 19, 2013 09:40:09 AM Peter Hutterer wrote:
> > > + memset(&abs, 0, sizeof(abs));
> > > + for (i = valid_cnt; i < cnt; ++i)
> > > + if (copy_to_user(&pinfo->info[i], &abs, sizeof(abs)))
> > > + return -EFAULT;
> > > +
> > > + return 0;
> >
> > why don't you return the number of valid copied axes to the user?
> > that seems better even than forcing the remainder to 0.
>
> Well, if your program messed up buffers that it faulted we do not know
> for sure if data that did not cause fault ended up where it should have
> or if it smashed something else. This condition I think should be
> signaled early.

not 100% sure I understand but I wasn't proposing to remove the -EFAULT, i
was proposing to replace "return 0" with "return valid_cnt".

Cheers,
Peter
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