Re: [RFC PATCH] x86/mce: Make mce_rdmsrl() do a plain RDMSR only

From: Borislav Petkov
Date: Wed Sep 09 2020 - 16:03:36 EST

On Wed, Sep 09, 2020 at 11:20:51AM -0700, Luck, Tony wrote:
> Do we think there will be other places where we want this
> MSR-or-die behaviour?

MSR-or-die - I like that. That belongs on a T-shirt. :-)

> If there are, then most of this belongs elsewhere from
> arch/x86/kernel/cpu/mce/core.c

Yeah, I can't think of any other users needing this ATM. But if they do,
lifting those and moving them somewhere else is trivial.

> The "_once" version seems a little pointless when the next statement
> in the function is "panic()".

True, removed.

> "warn" seems understated for an error that is going to crash the system.
> Just go for "pr_emerg()".


> There seems no consistency on using "rIP" or "RIP" ... but I think "RIP"
> is slightly ahead.

The "r" in rIP means that it can be RIP or EIP and that code builds on
32-bit too.

> nitpick: I don't thing Architectural needs to be capitalized.


> Ugh. Is this why you have warn_once() ... because panic might return?

People tend to put all kinds of things in panic() and I want to make
sure that even if it returns for whatever reason, at some point in
the future, we don't make any further progress here. Think of it as a
paranoid precation of sorts...