linux-kernel - Re: [PATCH v2 5/7] x86/mce: Change default mce logger to check mce->kflags

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Message-ID: <20200407193710.GE9616@zn.tnic>
Date:   Tue, 7 Apr 2020 21:37:11 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     "Luck, Tony" <tony.luck@...el.com>
Cc:     "x86@...nel.org" <x86@...nel.org>,
        Andy Lutomirski <luto@...nel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 5/7] x86/mce: Change default mce logger to check
 mce->kflags

On Tue, Apr 07, 2020 at 04:43:29PM +0000, Luck, Tony wrote:
> >> +	if (m->kflags)
> >> +		pr_emerg(HW_ERR "kflags = 0x%llx\n", m->kflags);
> >
> > I've zapped that hunk. I'd like to avoid exposing those kflags to
> > luserspace in any shape or form for now.
> 
> Sure. It was useful while I was debugging. But I'm sure all the bugs are
> gone now :-)

Do you need it for debugging?

If yes, it should be really clear that it is a debugging print and
nothing should rely on it. We could do a cmdline-param controllable
debugging scheme which tools cannot mistakenly start using and it
becomes an ABI, all of a sudden.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette