Re: [PATCH v4 05/27] x86: Replace ist_enter() with nmi_enter()

[Peter Zijlstra]

On Fri, Feb 21, 2020 at 11:05:36AM -0800, Andy Lutomirski wrote:

> > -       /*
> > -        * Use ist_enter despite the fact that we don't use an IST stack.
> > -        * We can be called from a kprobe in non-CONTEXT_KERNEL kernel
> > -        * mode or even during context tracking state changes.
> > -        *
> > -        * This means that we can't schedule.  That's okay.
> > -        */
> > -       ist_enter(regs);
> > +       nmi_enter();
> 
> I agree with the change, but some commentary might be nice.  Maybe
> copy from here:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/luto/linux.git/commit/?h=x86/idtentry&id=061eaa900b4f63601ab6381ab431fcef8dfd84be

Fair enough; I'll add something to #DB and #BP for that.