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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 D2884C10F13 for ; Mon, 8 Apr 2019 19:14:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A5EF92190B for ; Mon, 8 Apr 2019 19:14:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554750881; bh=tnJbTWW21PlO5Pu7ffmK6C//X8IHmjWs41PxznQuR0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:List-ID:From; b=VgS58rRBc7IkKMr02zzUtXDdbCTqNLd+OiZW7Dst5ziF6/Cmd5ebqFC/F16KxHQub jzxHvor7QzoZmSlj08L+nXbDp4sXdq8SHFjpecT988qFiMkZ3pUP19pfiJ97tksgAC Pv7D742xj0YOylRYdUs1QaRemmKxRuIFPQh8xdhw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728883AbfDHTOk (ORCPT ); Mon, 8 Apr 2019 15:14:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:45402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728642AbfDHTOd (ORCPT ); Mon, 8 Apr 2019 15:14:33 -0400 Received: from tzanussi-mobl.hsd1.il.comcast.net (c-98-220-238-81.hsd1.il.comcast.net [98.220.238.81]) (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 943A5218FD; Mon, 8 Apr 2019 19:14:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554750873; bh=tnJbTWW21PlO5Pu7ffmK6C//X8IHmjWs41PxznQuR0s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=WWoBUwyW0wzwscycbTfxfZQUr4Um5TTqqqYYMS5VycPzlU57NTh5Kz8OrkgilzlyN hjkQN3f3/FmUf+vabKFq5FAsARgsTlded6KU5mcmg/bMAo5DEtiQ81ftRwbXEw/b15 LJvtLe4om6fQKlodMSsu0aMiXrR/TkPHi0hvX1QY= From: Tom Zanussi To: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Cc: rostedt@goodmis.org, tglx@linutronix.de, C.Emde@osadl.org, jkacur@redhat.com, bigeasy@linutronix.de, daniel.wagner@siemens.com, julia@ni.com, amartin@nvidia.com Subject: [PATCH 09/13] x86: lazy-preempt: properly check against preempt-mask Date: Mon, 8 Apr 2019 14:14:11 -0500 Message-Id: <58de20b4bd55e3813c3988344f6a4de3e2881d5e.1554737688.git.tom.zanussi@linux.intel.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14.109-rt58-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Sebastian Andrzej Siewior [ Upstream commit 0f8a27bb5f45cc8a66f488549cecc4ce4d4533c2 ] should_resched() should check against preempt_offset after unmasking the need-resched-bit. Otherwise should_resched() won't work for preempt_offset != 0 and lazy-preempt set. Cc: stable-rt@vger.kernel.org Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Tom Zanussi --- arch/x86/include/asm/preempt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index 22992c837795..f66708779274 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -118,7 +118,7 @@ static __always_inline bool should_resched(int preempt_offset) /* preempt count == 0 ? */ tmp &= ~PREEMPT_NEED_RESCHED; - if (tmp) + if (tmp != preempt_offset) return false; if (current_thread_info()->preempt_lazy_count) return false; -- 2.14.1