linux-kernel - RE: [PATCH 1/2 v2] x86, mce, severity: extend the the mce

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Date:	Thu, 6 Nov 2014 18:32:37 +0000
From:	"Luck, Tony" <tony.luck@...el.com>
To:	Borislav Petkov <bp@...en8.de>
CC:	Chen Yucong <slaoub@...il.com>,
	"ak@...ux.intel.com" <ak@...ux.intel.com>,
	"aravind.gopalakrishnan@....com" <aravind.gopalakrishnan@....com>,
	"linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH 1/2 v2] x86, mce, severity: extend the the mce_severity

> Basically, this check is being done only for machine check exceptions
> only.

But you proposed setting excp by looking at mcg_status:
> excp = ((m->mcg_status & MCG_STATUS_MCIP) ? EXCP_CONTEXT : NO_EXCP);

Which makes the code rather self referential.  If we actually did arrive in MCE handler
with MCIP == 0 ... then your code would pretend that we'd arrived here from the
poll code, and skip over the test for MCIP - so fail to report that MCIP wasn't set.

-Tony