Re: [PATCH v2 -tip] x86/percpu: Use C for arch_raw_cpu_ptr()

From: Linus Torvalds
Date: Tue Oct 17 2023 - 15:01:07 EST


On Tue, 17 Oct 2023 at 00:23, Nadav Amit <namit@xxxxxxxxxx> wrote:
>
> Yes, the FPU issue is the one that caused me to crash before.

Uros, can you verify whether that patch of mine resolves the issue you saw?

That patch is _technically_ an actual bug-fix, although right now our
existing 'current' caching that depends on just CSE'ing the inline asm
(and is apparently limited to only doing so within single basic
blocks) doesn't actually trigger the bug in our __switch_to() logic in
practice.

Linus