Re: [PATCH v1 1/2] overflow: Allow to sum a few arguments at once

[Andy Shevchenko]

On Fri, Jun 19, 2026 at 08:27:33PM -0700, Kees Cook wrote:
> On Fri, Jun 19, 2026 at 09:45:18AM +0300, Andy Shevchenko wrote:
> > On Thu, Jun 18, 2026 at 08:47:34PM -0700, Kees Cook wrote:
> > > On Wed, Jun 17, 2026 at 01:12:36PM +0200, Andy Shevchenko wrote:

...

> > > > +#define __size_add4(addend1, addend2, addend3, addend4, addend5, ...)		\
> > > > +	__size_add(__size_add3(addend1,  addend2, addend3, addend4), addend5)
> > > 
> > > Is 4 the max seen in practice?
> > 
> > In patch 2 there are 5! In cover letter I also mentioned a new user
> > (there are actually three). And I remember seeing 3 somewhere else.
> 
> I feel like we should allow size_mul() to work this way too, though I
> don't find any users that would need it, so I guess just size_add()?

For now, yes. The array_size() can be modified as we have already two of them,
but I don't remember seeing more than 3, so it might look like an unneeded
churn.

> I'm fine for this to go via whatever tree is first to use it:
> 
> Acked-by: Kees Cook <kees@xxxxxxxxxx>

Thanks!

Johannes, are you okay to take a new version (I assume the wish is to have
the balanced additions)? If so, I will prepare one.

-- 
With Best Regards,
Andy Shevchenko