Re: [PATCH v3 1/2] minmax: sanity check constant bounds when clamping

Jason A. Donenfeld
2022-10-04T15:01:34Z

On Tue, Oct 04, 2022 at 07:39:53AM -0700, Kees Cook wrote:
>
>
> On October 4, 2022 6:41:48 AM PDT, "Jason A. Donenfeld" <Jason@zx2c4.com> wrote:
> >On Mon, Sep 26, 2022 at 8:26 PM Kees Cook <keescook@chromium.org> wrote:
> >>
> >> On Mon, Sep 26, 2022 at 03:34:34PM +0200, Jason A. Donenfeld wrote:
> >> > The clamp family of functions only makes sense if hi>=lo. If hi and lo
> >> > are compile-time constants, then raise a build error. Doing so has
> >> > already caught buggy code. This also introduces the infrastructure to
> >> > improve the clamping function in subsequent commits.
> >> >
> >> > Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
> >> > Cc: Andrew Morton <akpm@linux-foundation.org>
> >> > Cc: Kees Cook <keescook@chromium.org>
> >> > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> >>
> >> Reviewed-by: Kees Cook <keescook@chromium.org>
> >
> >Wondering - did you ever queue this up for 6.1? I assume the plan is
> >to hold off on 2/2 for the time being, but this 1/2 is good to have
> >either way.
>
> Since it produced at least one warning, there may be others in weird
> archs/configs, so I wanted it to bake in -next after the merge window
> for 6.1 closes. It's a good feature, but I didn't want to risk new
> build warnings so close to the merge. :)

Alright, sounds good. Hope it catches more things!

Jason