From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755154AbcGELka (ORCPT ); Tue, 5 Jul 2016 07:40:30 -0400 Received: from forward-corp1f.mail.yandex.net ([95.108.130.40]:50462 "EHLO forward-corp1f.mail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755092AbcGELkU (ORCPT ); Tue, 5 Jul 2016 07:40:20 -0400 X-Greylist: delayed 1162 seconds by postgrey-1.27 at vger.kernel.org; Tue, 05 Jul 2016 07:40:20 EDT Authentication-Results: smtpcorp1m.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Subject: [PATCH] kernel/watchdog: use nmi registers snapshot in hardlockup handler From: Konstantin Khlebnikov To: Andrew Morton , linux-kernel@vger.kernel.org Cc: Jiri Kosina , Ulrich Obergfell , Aaron Tomlin Date: Tue, 05 Jul 2016 14:20:47 +0300 Message-ID: <146771764784.86724.6006627197118544150.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org NMI handler doesn't call set_irq_regs(), so get_irq_regs() returns NULL or stale snapshot from beginning of IRQ interrupted by NMI. Registers from argument are always here and points to interrupted instruction and state. Signed-off-by: Konstantin Khlebnikov Cc: Jiri Kosina --- kernel/watchdog.c | 1 - 1 file changed, 1 deletion(-) diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 9acb29f280ec..6d1020c03d41 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -344,7 +344,6 @@ static void watchdog_overflow_callback(struct perf_event *event, */ if (is_hardlockup()) { int this_cpu = smp_processor_id(); - struct pt_regs *regs = get_irq_regs(); /* only print hardlockups once */ if (__this_cpu_read(hard_watchdog_warn) == true)