Re: Sanitize CPU-state when switching tasks (was sanitize CPU-statewhen switching from virtual-8086 mode to other task)

[H. Peter Anvin]

On 01/09/2014 04:42 PM, Linus Torvalds wrote:
> On Fri, Jan 10, 2014 at 6:58 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
>>
>> Ok, I was able to reproduce
> 
> Looking at this, I think this is just a bug in our
> restore_fpu_checking() hackery for X86_FEATURE_FXSAVE_LEAK..
> 
> Which also explains why it only triggers on E-350 - it's only relevant
> for those K7/K8 CPU's that use this.
> 
> Maybe just add a fcnlex to before the emms? Something like this
> (TOTALLY UNTESTED!!) attached patch.
> 

OK, that sounds very reasonable.  Boris, halfdog, does something like
this resolve your problem?

	-hpa


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