From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751774AbdFIStU (ORCPT ); Fri, 9 Jun 2017 14:49:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:38930 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682AbdFIStT (ORCPT ); Fri, 9 Jun 2017 14:49:19 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8AEDD22D40 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=luto@kernel.org From: Andy Lutomirski To: x86@kernel.org Cc: linux-kernel@vger.kernel.org, Borislav Petkov , Andy Lutomirski , stable@vger.kernel.org, Borislav Petkov , Peter Zijlstra , Thomas Gleixner Subject: [PATCH] sched/core: idle_task_exit() shouldn't use switch_mm_irqs_off() Date: Fri, 9 Jun 2017 11:49:15 -0700 Message-Id: X-Mailer: git-send-email 2.9.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org idle_task_exit() can be called with IRQs on x86 on and therefore should use switch_mm(), not switch_mm_irqs_off(). This doesn't seem to cause any problems right now, but it will confuse my upcoming TLB flush changes. Nonetheless, I think it should be backported because it's trivial. There won't be any meaningful performance impact because idle_task_exit() is only used when offlining a CPU. Cc: stable@vger.kernel.org Fixes: f98db6013c55 ("sched/core: Add switch_mm_irqs_off() and use it in the scheduler") Cc: Borislav Petkov Cc: Borislav Petkov Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Andy Lutomirski --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 803c3bc274c4..326d4f88e2b1 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5605,7 +5605,7 @@ void idle_task_exit(void) BUG_ON(cpu_online(smp_processor_id())); if (mm != &init_mm) { - switch_mm_irqs_off(mm, &init_mm, current); + switch_mm(mm, &init_mm, current); finish_arch_post_lock_switch(); } mmdrop(mm); -- 2.9.4