From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7BF41C3F68F for ; Thu, 23 Jan 2020 20:39:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 40256246B0 for ; Thu, 23 Jan 2020 20:39:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729459AbgAWUjz (ORCPT ); Thu, 23 Jan 2020 15:39:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:45862 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729160AbgAWUjq (ORCPT ); Thu, 23 Jan 2020 15:39:46 -0500 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BA5962468D; Thu, 23 Jan 2020 20:39:45 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.93) (envelope-from ) id 1iujGS-000mbl-Mj; Thu, 23 Jan 2020 15:39:44 -0500 Message-Id: <20200123203944.586250752@goodmis.org> User-Agent: quilt/0.65 Date: Thu, 23 Jan 2020 15:39:46 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org, linux-rt-users Cc: Thomas Gleixner , Carsten Emde , Sebastian Andrzej Siewior , John Kacur , Julia Cartwright , Daniel Wagner , Tom Zanussi , Scott Wood Subject: [PATCH RT 16/30] sched: migrate disable: Protect cpus_ptr with lock References: <20200123203930.646725253@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.19.94-rt39-rc2 stable review patch. If anyone has any objections, please let me know. ------------------ From: Scott Wood [ Upstream commit 27ee52a891ed2c7e2e2c8332ccae0de7c2674b09 ] Various places assume that cpus_ptr is protected by rq/pi locks, so don't change it before grabbing those locks. Signed-off-by: Scott Wood Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Steven Rostedt (VMware) --- kernel/sched/core.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index a29f33e776d0..d9a3f88508ee 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7250,9 +7250,8 @@ migrate_disable_update_cpus_allowed(struct task_struct *p) struct rq *rq; struct rq_flags rf; - p->cpus_ptr = cpumask_of(smp_processor_id()); - rq = task_rq_lock(p, &rf); + p->cpus_ptr = cpumask_of(smp_processor_id()); update_nr_migratory(p, -1); p->nr_cpus_allowed = 1; task_rq_unlock(rq, p, &rf); @@ -7264,9 +7263,8 @@ migrate_enable_update_cpus_allowed(struct task_struct *p) struct rq *rq; struct rq_flags rf; - p->cpus_ptr = &p->cpus_mask; - rq = task_rq_lock(p, &rf); + p->cpus_ptr = &p->cpus_mask; p->nr_cpus_allowed = cpumask_weight(&p->cpus_mask); update_nr_migratory(p, 1); task_rq_unlock(rq, p, &rf); -- 2.24.1