From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: Kernel panic from tg3 net driver Date: Thu, 20 Oct 2011 22:05:25 +0200 Message-ID: <1319141125.2854.14.camel@edumazet-laptop> References: <20111020.155659.486754557434415381.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: ari.m.savolainen@gmail.com, richardcochran@gmail.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: David Miller Return-path: In-Reply-To: <20111020.155659.486754557434415381.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le jeudi 20 octobre 2011 =C3=A0 15:56 -0400, David Miller a =C3=A9crit = : > From: Ari Savolainen > Date: Thu, 20 Oct 2011 22:30:44 +0300 >=20 > > I finally got time to continue bisecting. The commit that causes th= e > > kernel panic is: 2669069aacc9 "tg3: enable transmit time stamping.= " >=20 > I thought initially that the issue might be that we have to do the > skb_tx_timestamp() call before we advance the mailbox transmit > descriptor pointer. >=20 > But that shouldn't matter, we run with a lock held, and TX reclaim ta= kes > that same lock. >=20 > So I'm sort of stumped at the moment. But its not a panic, its a RCU splat ? > [ 105.612129] [] lockdep_rcu_dereference+0xbb/0xc= 0 > [ 105.612132] [] neigh_update+0x4f9/0x5f0 > [ 105.612135] [] ? neigh_lookup+0xe1/0x220 > [ 105.612139] [] arp_req_set+0xb8/0x230 > [ 105.612142] [] arp_ioctl+0x1bf/0x310 > [ 105.612146] [] ? lock_hrtimer_base.isra.26+0x30= /0x60 > [ 105.612150] [] inet_ioctl+0x85/0x90 > [ 105.612154] [] sock_do_ioctl+0x30/0x70 > [ 105.612157] [] sock_ioctl+0x73/0x280 > [ 105.612162] [] do_vfs_ioctl+0x98/0x570 > [ 105.612165] [] ? fget_light+0x340/0x3a0 > [ 105.612168] [] sys_ioctl+0x4f/0x80 > [ 105.612172] [] system_call_fastpath+0x16/0x1b And I think this was fixed yesterday ? De: roy.qing.li@gmail.com =C3=80: ari.m.savolainen@gmail.com, netdev@vger.kernel.org Sujet: [PATCH net-next] neigh: fix rcu splat in neigh_update() Date: Tue, 18 Oct 2011 16:32:42 +0800 (18/10/2011 10:32:42)