Messages in this thread | | | Date | Fri, 29 May 2020 10:00:36 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH 0/6] x86/entry: disallow #DB more |
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On Fri, May 29, 2020 at 07:05:54AM +0800, Lai Jiangshan wrote: > On Fri, May 29, 2020 at 6:48 AM Peter Zijlstra <peterz@infradead.org> 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@infradead.org> 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.
The only recoverable #DF is the ESPFIX shit. If we do not take that, we're on the way to panic(), I really can't be arsed if you crash the box before that, we're going to die anyway.
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