From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: mmotm 2010-04-28 - RCU whinges Date: Mon, 03 May 2010 07:41:07 +0200 Message-ID: <1272865267.2173.180.camel@edumazet-laptop> References: <201004290021.o3T0L04Y028017@imap1.linux-foundation.org> <5702.1272822394@localhost> <1272865137.2173.179.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Andrew Morton , Peter Zijlstra , Patrick McHardy , "David S. Miller" , linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, netdev@vger.kernel.org, "Paul E. McKenney" To: Valdis.Kletnieks@vt.edu Return-path: In-Reply-To: <1272865137.2173.179.camel@edumazet-laptop> Sender: netfilter-devel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le lundi 03 mai 2010 =C3=A0 07:38 +0200, Eric Dumazet a =C3=A9crit : > Le dimanche 02 mai 2010 =C3=A0 13:46 -0400, Valdis.Kletnieks@vt.edu a= =C3=A9crit : > > On Wed, 28 Apr 2010 16:53:32 PDT, akpm@linux-foundation.org said: > > > The mm-of-the-moment snapshot 2010-04-28-16-53 has been uploaded = to > > >=20 > > > http://userweb.kernel.org/~akpm/mmotm/ > >=20 > > I thought we swatted all these, hit another one... > >=20 > > [ 9.131490] ctnetlink v0.93: registering with nfnetlink. > > [ 9.131535] > > [ 9.131535] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D > > [ 9.131704] [ INFO: suspicious rcu_dereference_check() usage. ] > > [ 9.131794] --------------------------------------------------- > > [ 9.131883] net/netfilter/nf_conntrack_ecache.c:88 invoked rcu_d= ereference_check() without protection! > > [ 9.131977] > > [ 9.131977] other info that might help us debug this: > > [ 9.131978] > > [ 9.132218] > > [ 9.132219] rcu_scheduler_active =3D 1, debug_locks =3D 0 > > [ 9.132434] 1 lock held by swapper/1: > > [ 9.132519] #0: (nf_ct_ecache_mutex){+.+...}, at: [] nf_conntrack_register_notifier+0x1a/0x75 > > [ 9.132938] > > [ 9.132939] stack backtrace: > > [ 9.133129] Pid: 1, comm: swapper Tainted: G W 2.6.34-r= c5-mmotm0428 #1 > > [ 9.133220] Call Trace: > > [ 9.133319] [] lockdep_rcu_dereference+0xaa/0= xb2 > > [ 9.133410] [] nf_conntrack_register_notifier= +0x3d/0x75 > > [ 9.133521] [] ctnetlink_init+0x71/0xd5 > > [ 9.133627] [] ? ctnetlink_init+0x0/0xd5 > > [ 9.133735] [] do_one_initcall+0x59/0x14e > > [ 9.133843] [] kernel_init+0x144/0x1ce > > [ 9.133949] [] kernel_thread_helper+0x4/0x10 > > [ 9.134060] [] ? restore_args+0x0/0x30 > > [ 9.134196] [] ? kernel_init+0x0/0x1ce > > [ 9.134328] [] ? kernel_thread_helper+0x0/0x1= 0 > > [ 9.134530] ip_tables: (C) 2000-2006 Netfilter Core Team > > [ 9.134655] TCP bic registered > >=20 >=20 > Thanks for the report ! >=20 > We can use rcu_dereference_protected() in those cases. >=20 > [PATCH] net: Use rcu_dereference_protected in nf_conntrack_ecache >=20 > Writers own nf_ct_ecache_mutex. >=20 > Reported-by: Valdis Kletnieks > Signed-off-by: Eric Dumazet > --- Oops scratch that, I'll resend a correct version. -- To unsubscribe from this list: send the line "unsubscribe netfilter-dev= el" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html