From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Hajnoczi Subject: Re: [PATCH 1/2] tuntap: forbid calling TUNSETIFF when detached Date: Fri, 11 Jan 2013 15:42:36 +0100 Message-ID: <20130111144236.GC2310@stefanha-thinkpad.muc.redhat.com> References: <1357894242-25020-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, mst@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Jason Wang Return-path: Content-Disposition: inline In-Reply-To: <1357894242-25020-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Fri, Jan 11, 2013 at 04:50:41PM +0800, Jason Wang wrote: > @@ -1546,6 +1544,9 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr) > struct net_device *dev; > int err; > > + if (rcu_dereference_protected(tfile->detached, lockdep_rtnl_is_held())) > + return -EINVAL; > + How come none of the other tfile->detached users call rcu_*()? Stefan