Re: [PATCH 5.14 018/334] nbd: add the check to prevent overflow in __nbd_ioctl()

Nick Desaulniers
2021-09-13T20:37:07Z

On Mon, Sep 13, 2021 at 1:16 PM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Mon, Sep 13, 2021 at 1:10 PM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > On Mon, Sep 13, 2021 at 1:02 PM Nick Desaulniers
> > <ndesaulniers@google.com> wrote:
> > >
> > > Ha! I pulled+rebased and this code disappeared...I thought I had
> > > rebased on the wrong branch or committed work to master accidentally.
> > > Patch to stable-only inbound.
> >
> > Side note: for stable, can you look into using _Generic() instead of
> > __builtin_choose_expression() with typeof, or some
> > __builtin_types_compatible_p() magic?
> >
> > Yes, yes, we use __builtin_choose_expression() elsewhere, but we've
> > started using _Generic(), and it's really the more natural model - in
> > addition to being the standard C one.
> >
> > Of course, there may be some reason why _Generic() doesn't work, but
> > it _is_ the natural fit for any "for type X, do Y" kind of thing.
> >
> > No?
>
> Man, c'mon, I just got the __builtin_choose_expression() working! It's
> not...too bad...ish. (Besides, I'd actually have to learn how to use
> _Generic...I've never quite gotten anything I've written trying to use
> it to actually compile).
>
> Do we have access to _Generic in GCC 4.9?

Follow up thread, sorry/not sorry for not taking the full cc list:
https://lore.kernel.org/stable/20210913203201.1844253-1-ndesaulniers@google.com/
--
Thanks,
~Nick Desaulniers