From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:44018 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750930AbdKSL5Y (ORCPT ); Sun, 19 Nov 2017 06:57:24 -0500 Subject: Patch "x86/MCE/AMD: Always give panic severity for UC errors in kernel context" has been added to the 4.13-stable tree To: yazen.ghannam@amd.com, bp@suse.de, gregkh@linuxfoundation.org, linux-edac@vger.kernel.org, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, tony.luck@intel.com, torvalds@linux-foundation.org Cc: , From: Date: Sun, 19 Nov 2017 12:57:22 +0100 Message-ID: <151109264220191@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled x86/MCE/AMD: Always give panic severity for UC errors in kernel context to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: x86-mce-amd-always-give-panic-severity-for-uc-errors-in-kernel-context.patch and it can be found in the queue-4.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From d65dfc81bb3894fdb68cbc74bbf5fb48d2354071 Mon Sep 17 00:00:00 2001 From: Yazen Ghannam Date: Mon, 6 Nov 2017 18:46:32 +0100 Subject: x86/MCE/AMD: Always give panic severity for UC errors in kernel context From: Yazen Ghannam commit d65dfc81bb3894fdb68cbc74bbf5fb48d2354071 upstream. The AMD severity grading function was introduced in kernel 4.1. The current logic can possibly give MCE_AR_SEVERITY for uncorrectable errors in kernel context. The system may then get stuck in a loop as memory_failure() will try to handle the bad kernel memory and find it busy. Return MCE_PANIC_SEVERITY for all UC errors IN_KERNEL context on AMD systems. After: b2f9d678e28c ("x86/mce: Check for faults tagged in EXTABLE_CLASS_FAULT exception table entries") was accepted in v4.6, this issue was masked because of the tail-end attempt at kernel mode recovery in the #MC handler. However, uncorrectable errors IN_KERNEL context should always be considered unrecoverable and cause a panic. Signed-off-by: Yazen Ghannam Signed-off-by: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Cc: linux-edac Fixes: bf80bbd7dcf5 (x86/mce: Add an AMD severities-grading function) Link: http://lkml.kernel.org/r/20171106174633.13576-1-bp@alien8.de Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/mcheck/mce-severity.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/cpu/mcheck/mce-severity.c +++ b/arch/x86/kernel/cpu/mcheck/mce-severity.c @@ -245,6 +245,9 @@ static int mce_severity_amd(struct mce * if (m->status & MCI_STATUS_UC) { + if (ctx == IN_KERNEL) + return MCE_PANIC_SEVERITY; + /* * On older systems where overflow_recov flag is not present, we * should simply panic if an error overflow occurs. If @@ -255,10 +258,6 @@ static int mce_severity_amd(struct mce * if (mce_flags.smca) return mce_severity_amd_smca(m, ctx); - /* software can try to contain */ - if (!(m->mcgstatus & MCG_STATUS_RIPV) && (ctx == IN_KERNEL)) - return MCE_PANIC_SEVERITY; - /* kill current process */ return MCE_AR_SEVERITY; } else { Patches currently in stable-queue which might be from yazen.ghannam@amd.com are queue-4.13/x86-mce-amd-always-give-panic-severity-for-uc-errors-in-kernel-context.patch