From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: 2.6.39-rc6-mmotm0506 - another lockdep splat (networking this time) Date: Tue, 10 May 2011 05:47:51 +0200 Message-ID: <1304999271.3050.41.camel@edumazet-laptop> References: <6954.1304989523@localhost> <1304994188.3050.17.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Andrew Morton , "David S. Miller" , linux-kernel@vger.kernel.org, netdev@vger.kernel.org To: Valdis.Kletnieks@vt.edu Return-path: In-Reply-To: <1304994188.3050.17.camel@edumazet-laptop> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Le mardi 10 mai 2011 =C3=A0 04:23 +0200, Eric Dumazet a =C3=A9crit : > Thanks for the report, I am taking a look how to fix this. >=20 OK here is the official patch submission Thanks Valdis ! [PATCH net-next-2.6] net: fix two lockdep splats Commit e67f88dd12f6 (net: dont hold rtnl mutex during netlink dump callbacks) switched rtnl protection to RCU, but we forgot to adjust two rcu_dereference() lockdep annotations : inet_get_link_af_size() or inet_fill_link_af() might be called with rcu_read_lock or rtnl held, so use rcu_dereference_rtnl() instead of rtnl_dereference() Reported-by: Valdis Kletnieks Signed-off-by: Eric Dumazet --- net/ipv4/devinet.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c index cd9ca08..6b1eb92 100644 --- a/net/ipv4/devinet.c +++ b/net/ipv4/devinet.c @@ -1369,7 +1369,7 @@ errout: =20 static size_t inet_get_link_af_size(const struct net_device *dev) { - struct in_device *in_dev =3D __in_dev_get_rtnl(dev); + struct in_device *in_dev =3D rcu_dereference_rtnl(dev->ip_ptr); =20 if (!in_dev) return 0; @@ -1379,7 +1379,7 @@ static size_t inet_get_link_af_size(const struct = net_device *dev) =20 static int inet_fill_link_af(struct sk_buff *skb, const struct net_dev= ice *dev) { - struct in_device *in_dev =3D __in_dev_get_rtnl(dev); + struct in_device *in_dev =3D rcu_dereference_rtnl(dev->ip_ptr); struct nlattr *nla; int i; =20