Re: [bisected] 3c8ba0d61d04ced9f8d9ff93977995a9e4e96e91 oopses on s390

From: Kees Cook
Date: Mon Apr 09 2018 - 14:01:04 EST


On Mon, Apr 9, 2018 at 10:14 AM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Mon, Apr 9, 2018 at 10:03 AM, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> Our old "min()" had the internal variables called "min1" and "min2",
>> which is crazy too.
>
> Actually, no, it used the really cumbersome "__UNIQUE_ID" and then
> passed that odd as the name 'min1/2',
>
> Ugh, I find that really nasty to read, but it was obviously done
> because we hit this before.

Ooof. Nice find.

> And our __UNIQUE_ID() macro is garbage anyway, since it falls back on
> the line number, which doesn't really work for macros anyway. But we
> have proper macros for both clang and gcc, so maybe we should ignore
> the broken fallback.
>
> A patch like the attached, perhaps?

Can we update the comment near the top to explain why we need
__UNIQUE_ID() since we've now rediscovered why it was originally
there?

-Kees

--
Kees Cook
Pixel Security