Re: [for-linus][PATCH 01/10] tracing: Suppress sparse warnings triggered by is_signed_type()

From: Linus Torvalds
Date: Tue Aug 23 2022 - 19:57:27 EST


On Tue, Aug 23, 2022 at 4:18 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> Can you try the sparse version at
>
> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/sparse.git
>
> which I just set up temporarily with some patches of mine.

Ugh, and while testing this with sparse, I noticed that sparse itself
got that whole 'is_signed_type()' check wrong.

The sparse fix was to remove one line of code, but that one worries
me, because that one line was clearly very intentional:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/sparse.git/commit/?id=7e5f1c2eba1426e414698071dd0de7d039eb385d

Adding Al, since he's actually the original source of that bitwise
code (and did a lot of other sparse code on the type handling and
preprocessor side in particular).

Linus