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,URIBL_BLOCKED,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 310EDC4360C for ; Thu, 10 Oct 2019 08:47:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0644421D6C for ; Thu, 10 Oct 2019 08:47:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697251; bh=frKQUWaTNqxWUOAgl8M0QJm71Dy1KEBTrzhSMfb7V2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=NOJFGWYhK+3mhcMf1RBhl/aBtX8P3I03FejG7jNTa07jFEtByM2mg+y3yaogT3Aoi DTc4MI4KaOZq5shv2Z+LvnjAN7JRZpIZ4BHQSlnMCYNc8lv0Fa4Il7zhtvMKKV4WPK vItv2xu2czyoRg43fFyQmV2jLQabuBYwo2DizyLA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389474AbfJJIr3 (ORCPT ); Thu, 10 Oct 2019 04:47:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:53434 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389477AbfJJIr2 (ORCPT ); Thu, 10 Oct 2019 04:47:28 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 02BC6218AC; Thu, 10 Oct 2019 08:47:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570697247; bh=frKQUWaTNqxWUOAgl8M0QJm71Dy1KEBTrzhSMfb7V2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Sr/kNCd3QOea5yM4jxsRdF3ECRBlrwlcjLYPPm9wSfjUmPW9cSMaKKWz6jwQk9P1T RN/gJtXmSyl7SZQJ4fwmRCfkbKCxCU0XbQbg8LmPiUHIeooc+wzAzB3A404YDcHf2H smNqEZwqGHnR2Rau8VGn11oN7xvoMZh0829MUpPQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mathieu Desnoyers , "Peter Zijlstra (Intel)" , Chris Metcalf , Christoph Lameter , "Eric W. Biederman" , Kirill Tkhai , Linus Torvalds , Mike Galbraith , Oleg Nesterov , "Paul E. McKenney" , Russell King - ARM Linux admin , Thomas Gleixner , Ingo Molnar , Sasha Levin Subject: [PATCH 4.19 071/114] sched/membarrier: Fix private expedited registration check Date: Thu, 10 Oct 2019 10:36:18 +0200 Message-Id: <20191010083611.636681077@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191010083544.711104709@linuxfoundation.org> References: <20191010083544.711104709@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: Mathieu Desnoyers [ Upstream commit fc0d77387cb5ae883fd774fc559e056a8dde024c ] Fix a logic flaw in the way membarrier_register_private_expedited() handles ready state checks for private expedited sync core and private expedited registrations. If a private expedited membarrier registration is first performed, and then a private expedited sync_core registration is performed, the ready state check will skip the second registration when it really should not. Signed-off-by: Mathieu Desnoyers Signed-off-by: Peter Zijlstra (Intel) Cc: Chris Metcalf Cc: Christoph Lameter Cc: Eric W. Biederman Cc: Kirill Tkhai Cc: Linus Torvalds Cc: Mike Galbraith Cc: Oleg Nesterov Cc: Paul E. McKenney Cc: Peter Zijlstra Cc: Russell King - ARM Linux admin Cc: Thomas Gleixner Link: https://lkml.kernel.org/r/20190919173705.2181-2-mathieu.desnoyers@efficios.com Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin --- kernel/sched/membarrier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index 76e0eaf4654e0..dd27e632b1bab 100644 --- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -235,7 +235,7 @@ static int membarrier_register_private_expedited(int flags) * groups, which use the same mm. (CLONE_VM but not * CLONE_THREAD). */ - if (atomic_read(&mm->membarrier_state) & state) + if ((atomic_read(&mm->membarrier_state) & state) == state) return 0; atomic_or(MEMBARRIER_STATE_PRIVATE_EXPEDITED, &mm->membarrier_state); if (flags & MEMBARRIER_FLAG_SYNC_CORE) -- 2.20.1