Re: [PATCH] x86, FPU: Fix FPU initialization

Borislav Petkov
2013-04-15T22:04:12Z

On Mon, Apr 15, 2013 at 05:54:15PM +0200, Borislav Petkov wrote:
> On Mon, Apr 15, 2013 at 12:18:25PM +0200, Ingo Molnar wrote:
> > It was tip:master with x86/cpu merged in freshly.
>
> Ok, some more observations. I can trigger some oops similar yours (I
> haven't caught mine yet over serial or such) with latest tip/master +
> tip:x86/cpu.

Ok, here's the deal - it looks like a corruption which causes a couple
of different backtraces with different functions in the call trace. I've
bisected tip:x86/cpu and the evildoers are:

commit 3019653a57585602690fd38679326e9337f7ed7f
Author: Borislav Petkov <bp@suse.de>
Date: Wed Apr 10 21:37:03 2013 +0200

x86/fpu: Fix FPU initialization

commit c70293d0e3fef6b989cd8268027d410cf06ce384
Author: H. Peter Anvin <hpa@zytor.com>
Date: Mon Apr 8 17:57:43 2013 +0200

x86: Get rid of ->hard_math and all the FPU asm fu

I'll venture a guess and say that if you revert those, your .config
would boot on your K8 too.

So, I'd propose we take those 2 out for more careful inspection and
fixing and the rest of tip:x86/cpu can go upstream in the upcoming merge
window. IMHO of course.

Thanks.

--
Regards/Gruss,
Boris.

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