From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755168AbZDUINs (ORCPT ); Tue, 21 Apr 2009 04:13:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753910AbZDUIN3 (ORCPT ); Tue, 21 Apr 2009 04:13:29 -0400 Received: from hera.kernel.org ([140.211.167.34]:33821 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754734AbZDUINZ (ORCPT ); Tue, 21 Apr 2009 04:13:25 -0400 Date: Tue, 21 Apr 2009 08:12:42 GMT From: tip-bot for Rusty Russell To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, rostedt@goodmis.org, rusty@rustcorp.com.au, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, rostedt@goodmis.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: References: Subject: [tip:x86/urgent] x86: avoid theoretical spurious NMI backtraces with CONFIG_CPUMASK_OFFSTACK=y Message-ID: Git-Commit-ID: fcc5c4a2feea3886dc058498b28508b2731720d5 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Tue, 21 Apr 2009 08:12:44 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: fcc5c4a2feea3886dc058498b28508b2731720d5 Gitweb: http://git.kernel.org/tip/fcc5c4a2feea3886dc058498b28508b2731720d5 Author: Rusty Russell AuthorDate: Tue, 21 Apr 2009 16:03:41 +0930 Committer: Ingo Molnar CommitDate: Tue, 21 Apr 2009 10:09:50 +0200 x86: avoid theoretical spurious NMI backtraces with CONFIG_CPUMASK_OFFSTACK=y In theory (though not shown in practice) alloc_cpumask_var() doesn't zero memory, so CPUs might print an "NMI backtrace for cpu %d" once on boot. (Bug introduced in fcef8576d8a64fc603e719c97d423f9f6d4e0e8b). [ Impact: avoid theoretical syslog noise in rare configs ] Signed-off-by: Rusty Russell Cc: Steven Rostedt LKML-Reference: Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/nmi.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c index 2ba52f3..ce4fbfa 100644 --- a/arch/x86/kernel/apic/nmi.c +++ b/arch/x86/kernel/apic/nmi.c @@ -138,7 +138,7 @@ int __init check_nmi_watchdog(void) if (!prev_nmi_count) goto error; - alloc_cpumask_var(&backtrace_mask, GFP_KERNEL); + alloc_cpumask_var(&backtrace_mask, GFP_KERNEL|__GFP_ZERO); printk(KERN_INFO "Testing NMI watchdog ... "); #ifdef CONFIG_SMP