Re: [PATCH] Avoid that check_shl_overflow() triggers a compiler warning when building with W=1

[Kees Cook]

On Thu, Mar 7, 2019 at 7:40 AM Leon Romanovsky <leonro@xxxxxxxxxxxx> wrote:
>
> On Thu, Mar 07, 2019 at 06:53:54AM -0800, Bart Van Assche wrote:
> > On 3/6/19 11:24 PM, Leon Romanovsky wrote:
> > > My simple patch passes too :).
> >
> > Can you repost your patch?
>
> https://patchwork.kernel.org/patch/10841079/
>
> As Rasmus wrote, the thing is to avoid a < 0 check. In my patch,
> I converted a <= 0 to !(a > 0 || a == 0) expression.

I'd be happy either way. Is there a larger benefit to having a safe
"is_non_negative()" helper, or should we go with the minimal change to
the shl macro?

-Kees

-- 
Kees Cook