Re: [PATCH 2/5] Fonts: Make font size unsigned in font_desc

From: Daniel Vetter
Date: Wed Oct 28 2020 - 19:17:22 EST


On Wed, Oct 28, 2020 at 01:43:07AM -0400, Peilin Ye wrote:
> On Tue, Oct 27, 2020 at 07:50:58PM +0100, Daniel Vetter wrote:
> > On Tue, Oct 27, 2020 at 12:33:05PM -0400, Peilin Ye wrote:
> > > It is improper to define `width` and `height` as signed in `struct
> > > font_desc`. Make them unsigned. Also, change the corresponding printk()
> > > format identifiers from `%d` to `%u`, in sti_select_fbfont().
> > >
> > > Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx>
> >
> > I'm not entirely sure of the motivation here ... height/width should never
> > ever be even close to the limit here. Or have you seen integer math that
> > could potentially go wrong if we go with unsigned instead of int?
>
> Oh... No, I have not. I just thought we shouldn't represent a length
> using a signed value. Also, width and height in console_font are
> unsigned int - that shouldn't matter that much though.

Oh this is actually a good reason, since that's the uapi structure. And so
using the exact same signedness should help a bit with accidental casting
bugs.

If you mention this in the commit message I think this is good to go.
-Daniel

>
> [3/5] doesn't hunk properly without this patch, I'll send a v2 for [3/5]
> soon.
>
> Peilin
>

--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch