From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sowmini Varadhan Subject: Re: WARNING: suspicious RCU usage in rds_loop_conn_alloc Date: Mon, 12 Feb 2018 11:09:51 -0500 Message-ID: <20180212160951.GA21125@oracle.com> References: <001a1143e744e1cb89056505f466@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <001a1143e744e1cb89056505f466-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: syzbot Cc: davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, rds-devel-N0ozoZBvEnrZJqsBc5GL+g@public.gmane.org, santosh.shilimkar-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org, syzkaller-bugs-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org List-Id: linux-rdma@vger.kernel.org > rcu_scheduler_active = 2, debug_locks = 1 > 1 lock held by syzkaller563791/4086: > #0: (rcu_read_lock){....}, at: [<00000000bf5db0e6>] > __rds_conn_create+0xe46/0x1b50 net/rds/connection.c:218 > the rcu_read_lock() was added by ebeeb1ad9b. After we add that, everything in the rcu read critical section needs to use GFP_ATOMIC to avoid sleeping. I'll look into this fix. --Sowmini -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935032AbeBLQKI (ORCPT ); Mon, 12 Feb 2018 11:10:08 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:35378 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934825AbeBLQKG (ORCPT ); Mon, 12 Feb 2018 11:10:06 -0500 Date: Mon, 12 Feb 2018 11:09:51 -0500 From: Sowmini Varadhan To: syzbot Cc: davem@davemloft.net, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, rds-devel@oss.oracle.com, santosh.shilimkar@oracle.com, syzkaller-bugs@googlegroups.com Subject: Re: WARNING: suspicious RCU usage in rds_loop_conn_alloc Message-ID: <20180212160951.GA21125@oracle.com> References: <001a1143e744e1cb89056505f466@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <001a1143e744e1cb89056505f466@google.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8803 signatures=668668 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=483 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802120207 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > rcu_scheduler_active = 2, debug_locks = 1 > 1 lock held by syzkaller563791/4086: > #0: (rcu_read_lock){....}, at: [<00000000bf5db0e6>] > __rds_conn_create+0xe46/0x1b50 net/rds/connection.c:218 > the rcu_read_lock() was added by ebeeb1ad9b. After we add that, everything in the rcu read critical section needs to use GFP_ATOMIC to avoid sleeping. I'll look into this fix. --Sowmini