Re: [PATCH v4 10/10] x86/xsaves: Re-enable XSAVES

[Dave Hansen]

On 05/02/2016 09:11 AM, Yu-cheng Yu wrote:
> On Fri, Apr 29, 2016 at 05:40:44PM -0700, Dave Hansen wrote:
>> That's better than what we had before, but it relies entirely on testing
>> coverage and runtime checks.
>>
>> Is it too much to ask that you also take a look and audit all the places
>> the XSAVE buffer is accessed in the kernel and ensure that they either
>> have code to handle standard vs. compacted/supervisor or don't care for
>> some reason?
>>
>> I did such an audit once upon a time, but I think it would be a good
>> exercise to repeat both by a second set of eyes and because some time
>> has passed.
> 
> I think there are 12 files that can be directly impacted by XSAVES. 
> 
> 	arch/x86/include/asm/fpu/internal.h
> 	arch/x86/include/asm/fpu/types.h
> 	arch/x86/include/asm/fpu/xstate.h
> 	arch/x86/include/uapi/asm/sigcontext.h
> 	arch/x86/kernel/traps.c
> 	arch/x86/kernel/fpu/core.c
> 	arch/x86/kernel/fpu/init.c
> 	arch/x86/kernel/fpu/regset.c
> 	arch/x86/kernel/fpu/signal.c
> 	arch/x86/kernel/fpu/xstate.c
> 	arch/x86/kvm/x86.c
> 	arch/x86/mm/mpx.c
> 
> They have been reviewed from the perspective of the compacted format.
> Please let me know anything else.

Can you double-check that nothing has changed in mainline (or tip for
that matter) since you first did these checks?