From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753055Ab0EZPoL (ORCPT ); Wed, 26 May 2010 11:44:11 -0400 Received: from mtagate4.de.ibm.com ([195.212.17.164]:46244 "EHLO mtagate4.de.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752754Ab0EZPoI (ORCPT ); Wed, 26 May 2010 11:44:08 -0400 Date: Wed, 26 May 2010 17:45:07 +0200 From: Heiko Carstens To: "Paul E. McKenney" Cc: linux-kernel@vger.kernel.org, Dagmar Volkmann Subject: rcu: inet_timewait_sock.h:227 invoked rcu_dereference_check() without protection Message-ID: <20100526154507.GC2232@osiris.boeblingen.de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Paul, we got the following RCU trace here while doing some tests with 2.6.34 vanilla with some extra patches on top, but which do not touch RCU nor inet code. Would be nice if you could have a look at it. May 21 09:05:16 h0515017 kernel: =================================================== May 21 09:05:16 h0515017 kernel: [ INFO: suspicious rcu_dereference_check() usage. ] May 21 09:05:16 h0515017 kernel: --------------------------------------------------- May 21 09:05:16 h0515017 kernel: /home/autobuild/BUILD/linux-2.6.34-20100520/include/net/inet_timewait_sock.h:227 invoked rcu_dereference_check() without protection! May 21 09:05:16 h0515017 kernel: May 21 09:05:16 h0515017 kernel: other info that might help us debug this: May 21 09:05:16 h0515017 kernel: May 21 09:05:16 h0515017 kernel: May 21 09:05:16 h0515017 kernel: rcu_scheduler_active = 1, debug_locks = 0 May 21 09:05:16 h0515017 kernel: 1 lock held by swapper/0: May 21 09:05:16 h0515017 kernel: #0: (/home/autobuild/BUILD/linux-2.6.34-20100520/net/ipv4/tcp_minisocks.c:41){+.-...}, at: [<0000000000158398>] run_timer_softirq+0x1b4/0x354 May 21 09:05:16 h0515017 kernel: May 21 09:05:16 h0515017 kernel: stack backtrace: May 21 09:05:16 h0515017 kernel: CPU: 0 Not tainted 2.6.34-42.x.20100520-s390xdefault #1 May 21 09:05:16 h0515017 kernel: Process swapper (pid: 0, task: 0000000000812a18, ksp: 0000000000807e00) May 21 09:05:16 h0515017 kernel: 0000000000000000 000000003ffa7bc8 0000000000000002 0000000000000000 May 21 09:05:16 h0515017 kernel: 000000003ffa7c68 000000003ffa7be0 000000003ffa7be0 000000000056ba7c May 21 09:05:16 h0515017 kernel: 0000000000000000 0000000000000002 00000000000002d8 0000000000000000 May 21 09:05:16 h0515017 kernel: 000000000000000d 0000000000000000 000000003ffa7c38 000000000000000e May 21 09:05:16 h0515017 kernel: 00000000005c48a8 0000000000105a20 000000003ffa7bc8 000000003ffa7c10 May 21 09:05:16 h0515017 kernel: Call Trace: May 21 09:05:16 h0515017 kernel: ([<000000000010596e>] show_trace+0x142/0x148) May 21 09:05:16 h0515017 kernel: [<00000000004a5068>] __inet_twsk_kill+0x140/0x14c May 21 09:05:16 h0515017 kernel: [<00000000004a566c>] inet_twdr_do_twkill_work+0x90/0x130 May 21 09:05:16 h0515017 kernel: [<00000000004a585a>] inet_twdr_hangman+0x5e/0xec May 21 09:05:16 h0515017 kernel: [<000000000015842a>] run_timer_softirq+0x246/0x354 May 21 09:05:16 h0515017 kernel: [<00000000001514ae>] __do_softirq+0xfa/0x1b8 May 21 09:05:16 h0515017 kernel: [<0000000000112608>] do_softirq+0xe4/0xe8 May 21 09:05:16 h0515017 kernel: [<0000000000150f3c>] irq_exit+0xc0/0xe0 May 21 09:05:16 h0515017 kernel: [<000000000010f9ce>] do_extint+0x126/0x17c May 21 09:05:16 h0515017 kernel: [<0000000000119e5c>] ext_no_vtime+0x28/0x2c May 21 09:05:16 h0515017 kernel: [<0000000000116c10>] vtime_stop_cpu+0xac/0x100 May 21 09:05:16 h0515017 kernel: ([<0000000000116bb6>] vtime_stop_cpu+0x52/0x100) May 21 09:05:16 h0515017 kernel: [<000000000010c1a8>] cpu_idle+0xf8/0x190 May 21 09:05:16 h0515017 kernel: [<0000000000859cf0>] start_kernel+0x3b4/0x418 May 21 09:05:16 h0515017 kernel: [<0000000000100020>] _stext+0x20/0x80 May 21 09:05:16 h0515017 kernel: INFO: lockdep is turned off. Thanks, Heiko