Re: WARNING: CPU: 0 PID: 3031 at ./arch/x86/include/asm/fpu/internal.h:530 fpu__restore+0x90/0x130()

From: Borislav Petkov
Date: Wed Feb 17 2016 - 06:41:36 EST


On Wed, Feb 17, 2016 at 11:31:41AM +0100, Borislav Petkov wrote:
> On Wed, Feb 17, 2016 at 10:35:12AM +0100, Ingo Molnar wrote:
> > So it probably triggers on vanilla v4.4 (or v4.5-rc4) as well, with no
> > recent FPU bits applied?
>
> Nope, 4.4 doesn't trigger. Lemme try some of those other commits...

Results:

tip/x86/fpu:

58122bf1d856 x86/fpu: Default eagerfpu=on on all CPUs - BAD
c6ab109f7e0e x86/fpu: Speed up lazy FPU restores slightly - BAD
a20d7297045f x86/fpu: Fold fpu_copy() into fpu__copy() - BAD
5ed73f40735c x86/fpu: Fix FNSAVE usage in eagerfpu mode - BAD
4ecd16ec7059 x86/fpu: Fix math emulation in eager fpu mode - BAD
765bdb406de4 ("Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm") - BAD

...

v4.4: GOOD

so it must be something else causing it AFAICT.

I'll continue trying the -rc's and the tip/master merges to see what
causes it. Let me know if you have a better idea.

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.