Re: [PATCH 0/6] x86/entry: disallow #DB more

From: Lai Jiangshan
Date: Thu May 28 2020 - 19:06:14 EST


On Fri, May 29, 2020 at 6:48 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
>
> On Fri, May 29, 2020 at 06:42:46AM +0800, Lai Jiangshan wrote:
> > On Fri, May 29, 2020 at 4:25 AM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
> > >
> > > These patches disallow #DB during NMI/#MC and allow removing a lot of fugly code.
> > >
> >
> > Hello
> >
> > Will #DB be allowed in #DF?
>
> No, that whole thing is noinstr.

But it calls many functions, including die(), panic().
We don't want #DB to interfere how it die() and panic().
Since it is in fragile #DF, the #DB may mess it up and
make #DF fails to report and die.