From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steven Rostedt Subject: [PATCH RT 3/4] x86: Fix an RT MCE crash Date: Tue, 12 Jul 2016 15:08:31 -0400 Message-ID: <20160712190842.545233886@goodmis.org> References: <20160712190828.355044001@goodmis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Paul Gortmaker , Borislav Petkov , Corey Minyard To: linux-kernel@vger.kernel.org, linux-rt-users Return-path: Received: from mail.kernel.org ([198.145.29.136]:60790 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751058AbcGLTI4 (ORCPT ); Tue, 12 Jul 2016 15:08:56 -0400 Content-Disposition: inline; filename=0003-x86-Fix-an-RT-MCE-crash.patch Sender: linux-rt-users-owner@vger.kernel.org List-ID: 3.4.112-rt143-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Corey Minyard On some x86 systems an MCE interrupt would come in before the kernel was ready for it. Looking at the latest RT code, it has similar (but not quite the same) code, except it adds a bool that tells if MCE handling is initialized. That was required because they had switched to use swork instead of a kernel thread. Here, just checking to see if the thread is NULL is good enough to see if MCE handling is initialized. Suggested-by: Borislav Petkov Signed-off-by: Corey Minyard Signed-off-by: Steven Rostedt --- arch/x86/kernel/cpu/mcheck/mce.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 27068f690ede..674872b08ea4 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -1344,7 +1344,8 @@ static int mce_notify_work_init(void) static void mce_notify_work(void) { - wake_up_process(mce_notify_helper); + if (mce_notify_helper) + wake_up_process(mce_notify_helper); } #else static void mce_notify_work(void) -- 2.8.1