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 0BB74C352AA for ; Tue, 1 Oct 2019 16:51:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D2D5621783 for ; Tue, 1 Oct 2019 16:51:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948716; bh=frKQUWaTNqxWUOAgl8M0QJm71Dy1KEBTrzhSMfb7V2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=dwcHNWsdzDpZ/tXMgncJgIYVnwL2llgZY0ljD/P1IWx8hhca4CoRgph2FMHjuehwl GYYYVwyar9n/nv675bX0ygCeXHKHKbBxqrJsvcMI5uKMc/kYcLQ2+WSicB+jUAszjX 7zTtqYFrAK0gPyl7wT9oli9bF/l0ulPp7bAKwTFI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733094AbfJAQvz (ORCPT ); Tue, 1 Oct 2019 12:51:55 -0400 Received: from mail.kernel.org ([198.145.29.99]:56200 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733281AbfJAQoB (ORCPT ); Tue, 1 Oct 2019 12:44:01 -0400 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 A05C820B7C; Tue, 1 Oct 2019 16:43:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569948240; bh=frKQUWaTNqxWUOAgl8M0QJm71Dy1KEBTrzhSMfb7V2A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PFGQhCfxe4qF90Rrg1cYK/xWyed2G4idG6IASWGyGLhwS9MOaKzEFWJJS83f9gbOa ptaAIPiiiDLzDtzmq6Q49hK3M6PwJ4LAPJbl9rqVhabd8ii39WqLs5hUPIg3MkdGbu teqvjxGz5nEqGTs+jx/Lyc0rSOYpAiA4bxb/Irik= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Mathieu Desnoyers , Peter Zijlstra , 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 AUTOSEL 4.19 32/43] sched/membarrier: Fix private expedited registration check Date: Tue, 1 Oct 2019 12:43:00 -0400 Message-Id: <20191001164311.15993-32-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191001164311.15993-1-sashal@kernel.org> References: <20191001164311.15993-1-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: 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