Re: [PATCH 2/3] x86/mce: Fix incorrect "Machine check from unknown source" message

From: Borislav Petkov <bp@suse.de>
To: Tony Luck <tony.luck@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>,
	Qiuxu Zhuo <qiuxu.zhuo@intel.com>,
	Ashok Raj <ashok.raj@intel.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/3] x86/mce: Fix incorrect "Machine check from unknown source" message
Date: Tue, 29 May 2018 12:42:22 +0200	[thread overview]
Message-ID: <20180529104222.GA19870@zn.tnic> (raw)
In-Reply-To: <52e049a497e86fd0b71c529651def8871c804df0.1527283897.git.tony.luck@intel.com>

On Fri, May 25, 2018 at 02:41:55PM -0700, Tony Luck wrote:
> @@ -1287,12 +1292,17 @@ void do_machine_check(struct pt_regs *regs, long error_code)
>  			no_way_out = worst >= MCE_PANIC_SEVERITY;
>  	} else {
>  		/*
> -		 * Local MCE skipped calling mce_reign()
> -		 * If we found a fatal error, we need to panic here.
> +		 * If there was a fatal machine check we should have
> +		 * already called mce_panic earlier in this function.
> +		 * Since we re-read the banks, we might have found
> +		 * something new. Check again to see if we found a
> +		 * fatal error. We call "mce_severity()" again to
> +		 * make sure we have the right "msg".
>  		 */
> -		 if (worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3)
> -			mce_panic("Machine check from unknown source",
> -				NULL, NULL);
> +		if (worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) {
> +			severity = mce_severity(&m, cfg->tolerant, &msg, true);

Looking at this more while cleaning the whole thing up, that severity
doesn't get read anywhere past this line, AFAICT...

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
-- 