From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934069AbcIVL7p (ORCPT ); Thu, 22 Sep 2016 07:59:45 -0400 Received: from terminus.zytor.com ([198.137.202.10]:53698 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933278AbcIVL73 (ORCPT ); Thu, 22 Sep 2016 07:59:29 -0400 Date: Thu, 22 Sep 2016 04:58:39 -0700 From: tip-bot for Con Kolivas Message-ID: Cc: tglx@linutronix.de, linux-kernel@vger.kernel.org, mingo@kernel.org, hpa@zytor.com, peterz@infradead.org, kernel@kolivas.org, cchalpha@gmail.com Reply-To: peterz@infradead.org, kernel@kolivas.org, cchalpha@gmail.com, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@kernel.org, hpa@zytor.com In-Reply-To: <2042051.3vvUWIM0vs@hex> References: <2042051.3vvUWIM0vs@hex> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/core] sched/core: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn() Git-Commit-ID: 4fa5cd5245b627db88c9ca08ae442373b02596b4 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 4fa5cd5245b627db88c9ca08ae442373b02596b4 Gitweb: http://git.kernel.org/tip/4fa5cd5245b627db88c9ca08ae442373b02596b4 Author: Con Kolivas AuthorDate: Tue, 13 Sep 2016 16:27:05 +1000 Committer: Ingo Molnar CommitDate: Thu, 22 Sep 2016 12:28:00 +0200 sched/core: Do not use smp_processor_id() with preempt enabled in smpboot_thread_fn() We should not be using smp_processor_id() with preempt enabled. Bug identified and fix provided by Alfred Chen. Reported-by: Alfred Chen Signed-off-by: Con Kolivas Cc: Alfred Chen Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/2042051.3vvUWIM0vs@hex Signed-off-by: Ingo Molnar --- kernel/smpboot.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/smpboot.c b/kernel/smpboot.c index 13bc43d..fc0d8270 100644 --- a/kernel/smpboot.c +++ b/kernel/smpboot.c @@ -122,12 +122,12 @@ static int smpboot_thread_fn(void *data) if (kthread_should_park()) { __set_current_state(TASK_RUNNING); - preempt_enable(); if (ht->park && td->status == HP_THREAD_ACTIVE) { BUG_ON(td->cpu != smp_processor_id()); ht->park(td->cpu); td->status = HP_THREAD_PARKED; } + preempt_enable(); kthread_parkme(); /* We might have been woken for stop */ continue;