From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Horman Subject: Re: [PATCH] net: Statically initialize init_net.dev_base_head Date: Wed, 18 Jul 2012 16:11:49 -0400 Message-ID: <20120718201149.GB22057@hmsreliant.think-freely.org> References: <20120718190607.22923.77935.stgit@host1-mdrustad.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, davem@davemloft.net, gaofeng@cn.fujitsu.com, eric.dumazet@gmail.com To: Mark Rustad Return-path: Received: from charlotte.tuxdriver.com ([70.61.120.58]:56105 "EHLO smtp.tuxdriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753015Ab2GRULy (ORCPT ); Wed, 18 Jul 2012 16:11:54 -0400 Content-Disposition: inline In-Reply-To: <20120718190607.22923.77935.stgit@host1-mdrustad.localdomain> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Jul 18, 2012 at 12:06:07PM -0700, Mark Rustad wrote: > This change eliminates an initialization-order hazard most > recently seen when netprio_cgroup is built into the kernel. > > With thanks to Eric Dumazet for catching a bug. > > Signed-off-by: Mark Rustad > --- > > net/core/dev.c | 3 ++- > net/core/net_namespace.c | 4 +++- > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/net/core/dev.c b/net/core/dev.c > index 0f28a9e..1cb0d8a 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -6283,7 +6283,8 @@ static struct hlist_head *netdev_create_hash(void) > /* Initialize per network namespace state */ > static int __net_init netdev_init(struct net *net) > { > - INIT_LIST_HEAD(&net->dev_base_head); > + if (net != &init_net) > + INIT_LIST_HEAD(&net->dev_base_head); > > net->dev_name_head = netdev_create_hash(); > if (net->dev_name_head == NULL) > diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c > index dddbacb..42f1e1c 100644 > --- a/net/core/net_namespace.c > +++ b/net/core/net_namespace.c > @@ -27,7 +27,9 @@ static DEFINE_MUTEX(net_mutex); > LIST_HEAD(net_namespace_list); > EXPORT_SYMBOL_GPL(net_namespace_list); > > -struct net init_net; > +struct net init_net = { > + .dev_base_head = LIST_HEAD_INIT(init_net.dev_base_head), > +}; > EXPORT_SYMBOL(init_net); > > #define INITIAL_NET_GEN_PTRS 13 /* +1 for len +2 for rcu_head */ > > I think dave was going to take John Fastabends patch from earlier today, but this works just as well. Long term I'm going to look into delaying initzlization for cgroups, as it creates a strange initialization state when you have a module_init routine registered. Neil