Re: [PATCH] x86/fpu: Reset MXCSR to default in kernel_fpu_begin()

[Borislav Petkov]

On Tue, Jun 16, 2020 at 09:53:39AM -0700, Andy Lutomirski wrote:
> On Tue, Jun 16, 2020 at 2:53 AM Borislav Petkov <bp@xxxxxxxxx> wrote:
> >
> > Ok,
> >
> > here's the fix first so that it goes in. I'll hammer on the test case later.
> 
> Does the 32-bit case need FNINIT?

Pasting from IRC:

I'm thinking if you'd need to reinit the FPU, then you need to do it for
both, not only 32-bit or do you mean something else? Also, if you end up
doing FNSAVE (old CPU) that one reinits state.

Whatever we decide doing, this should be a separate patch anyway.

Thx.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette