Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755999AbbGOKEd (ORCPT ); Wed, 15 Jul 2015 06:04:33 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:44995 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752898AbbGOJNv (ORCPT ); Wed, 15 Jul 2015 05:13:51 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Borislav Petkov , "H. Peter Anvin" , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Tony Luck , Ingo Molnar , Kamal Mostafa , Luis Henriques Subject: [PATCH 3.16.y-ckt 014/185] x86/mce: Fix MCE severity messages Date: Wed, 15 Jul 2015 10:10:09 +0100 Message-Id: <1436951580-15977-15-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1436951580-15977-1-git-send-email-luis.henriques@canonical.com> References: <1436951580-15977-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.16 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2879 Lines: 78 3.16.7-ckt15 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Borislav Petkov commit 17fea54bf0ab34fa09a06bbde2f58ed7bbdf9299 upstream. Derek noticed that a critical MCE gets reported with the wrong error type description: [Hardware Error]: CPU 34: Machine Check Exception: 5 Bank 9: f200003f000100b0 [Hardware Error]: RIP !INEXACT! 10: {intel_idle+0xb1/0x170} [Hardware Error]: TSC 49587b8e321cb [Hardware Error]: PROCESSOR 0:306e4 TIME 1431561296 SOCKET 1 APIC 29 [Hardware Error]: Some CPUs didn't answer in synchronization [Hardware Error]: Machine check: Invalid ^^^^^^^ The last line with 'Invalid' should have printed the high level MCE error type description we get from mce_severity, i.e. something like: [Hardware Error]: Machine check: Action required: data load error in a user process this happens due to the fact that mce_no_way_out() iterates over all MCA banks and possibly overwrites the @msg argument which is used in the panic printing later. Change behavior to take the message of only and the (last) critical MCE it detects. Reported-by: Derek Signed-off-by: Borislav Petkov Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Tony Luck Link: http://lkml.kernel.org/r/1431936437-25286-3-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar [ kamal: backport to 3.13-stable: context ] Signed-off-by: Kamal Mostafa Signed-off-by: Luis Henriques --- arch/x86/kernel/cpu/mcheck/mce.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 9a79c8dbd8e8..5648b506f3ae 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -660,6 +660,7 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp, struct pt_regs *regs) { int i, ret = 0; + char *tmp; for (i = 0; i < mca_cfg.banks; i++) { m->status = mce_rdmsrl(MSR_IA32_MCx_STATUS(i)); @@ -668,8 +669,11 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp, if (quirk_no_way_out) quirk_no_way_out(i, m, regs); } - if (mce_severity(m, mca_cfg.tolerant, msg) >= MCE_PANIC_SEVERITY) + + if (mce_severity(m, mca_cfg.tolerant, &tmp) >= MCE_PANIC_SEVERITY) { + *msg = tmp; ret = 1; + } } return ret; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/