From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932075AbbIOJLj (ORCPT ); Tue, 15 Sep 2015 05:11:39 -0400 Received: from mail.kernel.org ([198.145.29.136]:53320 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751721AbbIOJLd (ORCPT ); Tue, 15 Sep 2015 05:11:33 -0400 From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Borislav Petkov , "H. Peter Anvin" , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Tony Luck , Ingo Molnar , Zefan Li Subject: [PATCH 3.4 111/146] x86/mce: Fix MCE severity messages Date: Tue, 15 Sep 2015 17:03:46 +0800 Message-Id: <1442307861-32031-111-git-send-email-lizf@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1442307787-31952-1-git-send-email-lizf@kernel.org> References: <1442307787-31952-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov 3.4.109-rc1 review patch. If anyone has any objections, please let me know. ------------------ 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 [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li --- arch/x86/kernel/cpu/mcheck/mce.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 0d2db0e..9eeaed4 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -652,11 +652,14 @@ EXPORT_SYMBOL_GPL(machine_check_poll); static int mce_no_way_out(struct mce *m, char **msg) { int i; + char *tmp; for (i = 0; i < banks; i++) { m->status = mce_rdmsrl(MSR_IA32_MCx_STATUS(i)); - if (mce_severity(m, tolerant, msg) >= MCE_PANIC_SEVERITY) + if (mce_severity(m, tolerant, &tmp) >= MCE_PANIC_SEVERITY) { + *msg = tmp; return 1; + } } return 0; } -- 1.9.1