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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY 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 CB199C2D0A3 for ; Fri, 6 Nov 2020 08:52:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 633B620936 for ; Fri, 6 Nov 2020 08:52:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="r3MCFurX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726422AbgKFIwk (ORCPT ); Fri, 6 Nov 2020 03:52:40 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:52704 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726075AbgKFIwj (ORCPT ); Fri, 6 Nov 2020 03:52:39 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A68n23R059812; Fri, 6 Nov 2020 08:52:18 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=date : from : to : cc : subject : message-id : mime-version : content-type; s=corp-2020-01-29; bh=hdn3S6G4CZ9K6laz9yIdjncIsG6hx8UfoRsDLSDj7Cc=; b=r3MCFurXvxw6VH30+BpBL/iLkG9zfbW90V0aivuUIG37aBoX6BdCRhYrYHqo3bSCcrZP q4jcrELDM51Erem499ec0SOlvwNU4ibutEKmmJ+R6Gh8ZarvtI/TAD5F3eDTNXmGDtY+ JOOK9ONDKTUvu+6B4+3ktfZk+aax0Wk5ShmzSUiepAoOZWdc5/9rrxmDLgA/6SAWv8ZG M+jyY5FVqKGAYr0ONxXKjweKE6VofLKEJJ4/CqeMFXnO4aYpKmdM9Lt4ikua+/k7iwLD ubZOfjZ6xWNkH5vaESacio1+wtbq2DSVtRrOpzFHAPIdzg9QnH9lvARO3ddoyyu0xXB0 wA== Received: from userp3020.oracle.com (userp3020.oracle.com [156.151.31.79]) by userp2120.oracle.com with ESMTP id 34hhw2yvgw-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 06 Nov 2020 08:52:18 +0000 Received: from pps.filterd (userp3020.oracle.com [127.0.0.1]) by userp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0A68oo64166690; Fri, 6 Nov 2020 08:52:18 GMT Received: from aserv0122.oracle.com (aserv0122.oracle.com [141.146.126.236]) by userp3020.oracle.com with ESMTP id 34hw0jwc5m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 06 Nov 2020 08:52:18 +0000 Received: from abhmp0011.oracle.com (abhmp0011.oracle.com [141.146.116.17]) by aserv0122.oracle.com (8.14.4/8.14.4) with ESMTP id 0A68qC36031674; Fri, 6 Nov 2020 08:52:17 GMT Received: from mwanda (/10.175.216.98) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Fri, 06 Nov 2020 00:52:11 -0800 Date: Fri, 6 Nov 2020 11:52:05 +0300 From: Dan Carpenter To: Peter Zijlstra , Thomas Gleixner Cc: Ingo Molnar , Darren Hart , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH] futex: Don't enable IRQs unconditionally in put_pi_state() Message-ID: <20201106085205.GA1159983@mwanda> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Mailer: git-send-email haha only kidding X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9796 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 mlxlogscore=999 phishscore=0 bulkscore=0 spamscore=0 malwarescore=0 mlxscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011060064 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9796 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 adultscore=0 malwarescore=0 mlxscore=0 suspectscore=0 clxscore=1011 priorityscore=1501 impostorscore=0 spamscore=0 lowpriorityscore=0 mlxlogscore=999 phishscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2011060064 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Archived-At: List-Archive: List-Post: The exit_pi_state_list() function calls put_pi_state() with IRQs disabled and is not expecting that IRQs will be enabled inside the function. Use the _irqsave() so that IRQs are restored to the original state instead of enabled unconditionally. Fixes: 153fbd1226fb ("futex: Fix more put_pi_state() vs. exit_pi_state_list() races") Signed-off-by: Dan Carpenter --- This is from static analysis and not tested. I am not very familiar with futex code. kernel/futex.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index f8614ef4ff31..ca84745713bc 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -788,8 +788,9 @@ static void put_pi_state(struct futex_pi_state *pi_state) */ if (pi_state->owner) { struct task_struct *owner; + unsigned long flags; - raw_spin_lock_irq(&pi_state->pi_mutex.wait_lock); + raw_spin_lock_irqsave(&pi_state->pi_mutex.wait_lock, flags); owner = pi_state->owner; if (owner) { raw_spin_lock(&owner->pi_lock); @@ -797,7 +798,7 @@ static void put_pi_state(struct futex_pi_state *pi_state) raw_spin_unlock(&owner->pi_lock); } rt_mutex_proxy_unlock(&pi_state->pi_mutex, owner); - raw_spin_unlock_irq(&pi_state->pi_mutex.wait_lock); + raw_spin_unlock_irqrestore(&pi_state->pi_mutex.wait_lock, flags); } if (current->pi_state_cache) { -- 2.28.0