Re: [PATCH v2] x86/fpu: Disable BH while while loading FPU registers in __fpu__restore_sig()

Sebastian Andrzej Siewior
2018-11-19T17:31:46Z

On 2018-11-19 18:27:43 [+0100], Borislav Petkov wrote:
> On Mon, Nov 19, 2018 at 06:11:29PM +0100, Sebastian Andrzej Siewior wrote:
> > On 2018-11-19 09:02:45 [-0800], Dave Hansen wrote:
> > > On 11/19/18 8:04 AM, Sebastian Andrzej Siewior wrote:
> > > > v1…v2: A more verbose commit as message.
> > >
> > > I was really hoping for code comments. :)
> >
> > I though we agreed to make those in the larger series because those
> > comments in __fpu__restore_sig() would be removed anyway (as part of the
> > series).
>
> Also, over local_bh_disable() does not really fit as this is generic
> code and Sebastian said ARM does the whole thing a bit differently, for
> one.
>
> We probably should put that comment somewhere prominent in
> arch/x86/kernel/fpu/core.c or similar - somewhere people poking at FPU
> stuff will see it.

I though about __fpregs_changes_begin() in the last patch of the commit:
https://git.kernel.org/pub/scm/linux/kernel/git/bigeasy/staging.git/commit/?h=x86_fpu_rtu_v4

Sebastian