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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 496A0C2D0DB for ; Fri, 24 Jan 2020 09:41:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1FE2521556 for ; Fri, 24 Jan 2020 09:41:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579858910; bh=sDI6lGzmww86chtQAgCBVr2HYzxBsS5wuFzI9E7yLr0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CBATvoc1KUosGS+xCi2YAhGGmpVq067YYqt+BvVy24KzXiWjSSsz/BjlKQyzle3xx hpaIvqwwHfMwMpfdQfErGA/bnLFTinev+q6zknUY7b9UUe6CO4f7Jv0iEdvuuQGIQI 30mBOAHATxMPChD2zaiIlllfkQu74rCQu0Irh5Wo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733067AbgAXJlq (ORCPT ); Fri, 24 Jan 2020 04:41:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:39296 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731809AbgAXJlp (ORCPT ); Fri, 24 Jan 2020 04:41:45 -0500 Received: from localhost (unknown [145.15.244.15]) (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 49C3820718; Fri, 24 Jan 2020 09:41:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579858905; bh=sDI6lGzmww86chtQAgCBVr2HYzxBsS5wuFzI9E7yLr0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R5yCG5lRNop9QGPcgkpRExKJ7WNaOaMzM8gcakZRVj0rqhFtKvY9oCmEE5fSrryP7 8p3mVCiwklwFuAv3WePZGtp+dApN7UcsOciBBBWaXAAWU/w+N9j7I1kJmFEmNzW1M7 3PfNIoNdrcVYI5f+XU8PzBygjXKN5eQ5uN5S3RSU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sebastian Andrzej Siewior , Tejun Heo , Sasha Levin Subject: [PATCH 5.4 087/102] workqueue: Add RCU annotation for pwq list walk Date: Fri, 24 Jan 2020 10:31:28 +0100 Message-Id: <20200124092819.804917979@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124092806.004582306@linuxfoundation.org> References: <20200124092806.004582306@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sebastian Andrzej Siewior [ Upstream commit 49e9d1a9faf2f71fdfd80a30697ee9a15070626d ] An additional check has been recently added to ensure that a RCU related lock is held while the RCU list is iterated. The `pwqs' are sometimes iterated without a RCU lock but with the &wq->mutex acquired leading to a warning. Teach list_for_each_entry_rcu() that the RCU usage is okay if &wq->mutex is acquired during the list traversal. Fixes: 28875945ba98d ("rcu: Add support for consolidated-RCU reader checking") Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin --- kernel/workqueue.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 649687622654b..e9c63b79e03f4 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -425,7 +425,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq); * ignored. */ #define for_each_pwq(pwq, wq) \ - list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node) \ + list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node, \ + lockdep_is_held(&wq->mutex)) \ if (({ assert_rcu_or_wq_mutex(wq); false; })) { } \ else -- 2.20.1