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

[Leon Romanovsky]

On Thu, Mar 07, 2019 at 09:12:40AM -0800, Kees Cook wrote:
> On Thu, Mar 7, 2019 at 9:02 AM Leon Romanovsky <leonro@xxxxxxxxxxxx> wrote:
> >
> > On Thu, Mar 07, 2019 at 08:52:51AM -0800, Kees Cook wrote:
> > > 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?
> >
> > I personally prefer simplest possible solution.
>
> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>

Thanks

>
> Can this go via the rdma tree?

I think so, Jason advertised that we will have second PR to Linus
this merge window.

Thanks

>
> -Kees
>
> >
> > >
> > > -Kees
> > >
> > > --
> > > Kees Cook
> > -----BEGIN PGP SIGNATURE-----
> >
> > iQIcBAEBAgAGBQJcgU6mAAoJEORje4g2clinE94P/0pHFmUgwzRrVLxjqmnynNPC
> > e+azQISKrZ4EBI5Is7VwFJuxtiZvsTveCxX0NpRxk3TLfHbA4V9jz4meJ6smp4UQ
> > Z1uRnPbj2z5iucFN/8SelQvNTmqfvbuRSKpZ08XLxBB4XIAjFaNBbmD+REe7iSGD
> > xiYNp96oHvKnzGZq/eViqz0rogewsTLHoEBwDkfgyDIqwO0/3qVElNhW7Z6g/v/7
> > 2D4yZiB82wIBf+00taEQNnpI/3naVvqdfl34iYGuq51Fd2S36lfmMZ1DUffd/Eq+
> > jRq8PiNisFK+0A/96hwi2npVN0LS4tA5at6PHhqOfVxMOt/XAmeKu3cCaxHhjbfb
> > Oi2+X9/EBDdgVmylssQFwjNaLuXB00109IVDcQGgzTsN8xoTNiwla8gt3fVhDWt+
> > X0jQuSnqtANt75/0mucirBoUppCB59aZ9ygolWe4UwBpVV0ZGH/0MFwcOhlpglGB
> > PbrKaTxP3qQeil8wGXQsJyPGOCLBGh1Qj0C6NG1wsJSX/Zq8awEoz+JlYCXezaq6
> > 4R0jSHu50BGp7gt5iePRGeUhjPFVGHucJZ2b6fuDZ3ARN8MtQYmrYDyRqnFJZsCE
> > UZFd4SZ8UzfIETd17IowOmOs62HwXyIi1WzoWjiHsNjH2dxwiB6Lh1JBvAFQgzJ1
> > 0wRa0DMnyLzmIoOdyvQm
> > =NFtk
> > -----END PGP SIGNATURE-----
>
>
>
> --
> Kees Cook

Attachment: signature.asc
Description: PGP signature