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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 15899C33CAF for ; Thu, 16 Jan 2020 19:21:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB88020661 for ; Thu, 16 Jan 2020 19:21:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579202519; bh=qgdOWZabXt34xWiRajR8PsmrAsWphHFAb8ZMnR3Iz04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=V0b1TnyUeN1LuAVliAimvH8sxUpR8iPz4dOp5HvTqOdpf1pRO2Ia7ZFQG5JSbNhuj 2BO43BXyiUXzRsED7ab4oK2rLEH8sKF2ROTt0wuLHXSJgOI2CVRFEGbaaAG6YiF+7y CYyeEiIjCS/SNB05nAT5H2pU0+eu6M5xuzLjeGP4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731054AbgAPQxe (ORCPT ); Thu, 16 Jan 2020 11:53:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:37354 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730974AbgAPQx3 (ORCPT ); Thu, 16 Jan 2020 11:53:29 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8C19620730; Thu, 16 Jan 2020 16:53:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579193609; bh=qgdOWZabXt34xWiRajR8PsmrAsWphHFAb8ZMnR3Iz04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k9n3K1vHPw6MjKkLYKzl9coeE4SGCs1pHNzNGkhi7hhOX7j9rcXmpNdLd3F+VYxim fsP45elqLdJ/kNORovcF2yftxxG8zv9PgapRBFPynJcAcIyJb3P5KVJgojgQS9vq1T NSuBsFBaOsCb5Nrr0nWslzuKxkWoFyo3MaEgCIVY= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sebastian Andrzej Siewior , Tejun Heo , Sasha Levin Subject: [PATCH AUTOSEL 5.4 147/205] workqueue: Add RCU annotation for pwq list walk Date: Thu, 16 Jan 2020 11:42:02 -0500 Message-Id: <20200116164300.6705-147-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116164300.6705-1-sashal@kernel.org> References: <20200116164300.6705-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 649687622654..e9c63b79e03f 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