linux-kernel - RE: [PATCH] x86/mce: Pay no attention to 'F' bit in MCACOD when parsing 'UC' errors.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 25 Jul 2013 18:01:33 +0000
From:	"Luck, Tony" <tony.luck@...el.com>
To:	"Naveen N. Rao" <naveen.n.rao@...ux.vnet.ibm.com>,
	"gong.chen@...ux.intel.com" <gong.chen@...ux.intel.com>
CC:	"bp@...e.de" <bp@...e.de>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH] x86/mce: Pay no attention to 'F' bit in MCACOD when
 parsing 'UC' errors.

	MCESEV(
+		PANIC, "Action required but kernel thread is not continuable",
+		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR, MCI_UC_SAR|MCI_ADDR),
+		MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, MCG_STATUS_RIPV|MCG_STATUS_EIPV),
+		KERNEL
+		),
+	MCESEV(
 		AR, "Action required: data load error in a user process",
 		SER, MASK(MCI_STATUS_OVER|MCI_UC_SAR|MCI_ADDR|MCACOD, MCI_UC_SAR|MCI_ADDR|MCACOD_DATA),
 		USER

This just gives us a better panic message. Right?  Without this we'd keep walking the
severity table until we hit the "Action required: unknown MCACOD" entry which will
match and force a panic anyway.

So I might look for better wording.  As far as the h/w is concerned the thread is continuable.
Linux is just not smart enough (yet) to take the required recovery action.

-Tony