Re: [RFC] #MC mess

From: Borislav Petkov
Date: Tue Feb 18 2020 - 15:09:05 EST

On Tue, Feb 18, 2020 at 09:02:00PM +0100, Peter Zijlstra wrote:
> Then please rewrite the #MC entry code to deal with nested exceptions
> unmasking the MCE, very similr to NMI.
> The moment you allow tracing, jump_labels or anything else you can
> expect #PF, #BP and probably #DB while inside #MC, those will then IRET
> and re-enable the #MC.

Yeah, I'd like to keep it simple and reenable all the crap we disabled
only on exit from the handler.

Dunno if we care about losing tracing samples when an MCE happened...

> The current situation is completely and utterly buggered.

Lovely. ;-(