From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Wed, 14 Dec 2011 06:29:43 +0000 Subject: [patch] vlan: add rtnl_dereference() annotations Message-Id: <20111214062943.GD7499@elgon.mountain> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Patrick McHardy Cc: "David S. Miller" , netdev@vger.kernel.org, kernel-janitors@vger.kernel.org, Jiri Pirko The original code generates a Sparse warning: net/8021q/vlan_core.c:336:9: error: incompatible types in comparison expression (different address spaces) It's ok to dereference __rcu pointers here because we are holding the RTNL lock. I've added some calls to rtnl_dereference() to silence the warning. Signed-off-by: Dan Carpenter --- I haven't tested this, and I'm not super familiar with this code. Please review it carefully. diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c index 1414c93..4d39d80 100644 --- a/net/8021q/vlan_core.c +++ b/net/8021q/vlan_core.c @@ -326,14 +326,16 @@ int vlan_vids_add_by_dev(struct net_device *dev, const struct net_device *by_dev) { struct vlan_vid_info *vid_info; + struct vlan_info *vlan_info; int err; ASSERT_RTNL(); - if (!by_dev->vlan_info) + vlan_info = rtnl_dereference(by_dev->vlan_info); + if (!vlan_info) return 0; - list_for_each_entry(vid_info, &by_dev->vlan_info->vid_list, list) { + list_for_each_entry(vid_info, &vlan_info->vid_list, list) { err = vlan_vid_add(dev, vid_info->vid); if (err) goto unwind; @@ -342,7 +344,7 @@ int vlan_vids_add_by_dev(struct net_device *dev, unwind: list_for_each_entry_continue_reverse(vid_info, - &by_dev->vlan_info->vid_list, + &vlan_info->vid_list, list) { vlan_vid_del(dev, vid_info->vid); } @@ -355,13 +357,15 @@ void vlan_vids_del_by_dev(struct net_device *dev, const struct net_device *by_dev) { struct vlan_vid_info *vid_info; + struct vlan_info *vlan_info; ASSERT_RTNL(); - if (!by_dev->vlan_info) + vlan_info = rtnl_dereference(by_dev->vlan_info); + if (!vlan_info) return; - list_for_each_entry(vid_info, &by_dev->vlan_info->vid_list, list) + list_for_each_entry(vid_info, &vlan_info->vid_list, list) vlan_vid_del(dev, vid_info->vid); } EXPORT_SYMBOL(vlan_vids_del_by_dev); From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Subject: [patch] vlan: add rtnl_dereference() annotations Date: Wed, 14 Dec 2011 09:29:43 +0300 Message-ID: <20111214062943.GD7499@elgon.mountain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: "David S. Miller" , netdev@vger.kernel.org, kernel-janitors@vger.kernel.org, Jiri Pirko To: Patrick McHardy Return-path: Received: from rcsinet15.oracle.com ([148.87.113.117]:16423 "EHLO rcsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751119Ab1LNGaH (ORCPT ); Wed, 14 Dec 2011 01:30:07 -0500 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: The original code generates a Sparse warning: net/8021q/vlan_core.c:336:9: error: incompatible types in comparison expression (different address spaces) It's ok to dereference __rcu pointers here because we are holding the RTNL lock. I've added some calls to rtnl_dereference() to silence the warning. Signed-off-by: Dan Carpenter --- I haven't tested this, and I'm not super familiar with this code. Please review it carefully. diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c index 1414c93..4d39d80 100644 --- a/net/8021q/vlan_core.c +++ b/net/8021q/vlan_core.c @@ -326,14 +326,16 @@ int vlan_vids_add_by_dev(struct net_device *dev, const struct net_device *by_dev) { struct vlan_vid_info *vid_info; + struct vlan_info *vlan_info; int err; ASSERT_RTNL(); - if (!by_dev->vlan_info) + vlan_info = rtnl_dereference(by_dev->vlan_info); + if (!vlan_info) return 0; - list_for_each_entry(vid_info, &by_dev->vlan_info->vid_list, list) { + list_for_each_entry(vid_info, &vlan_info->vid_list, list) { err = vlan_vid_add(dev, vid_info->vid); if (err) goto unwind; @@ -342,7 +344,7 @@ int vlan_vids_add_by_dev(struct net_device *dev, unwind: list_for_each_entry_continue_reverse(vid_info, - &by_dev->vlan_info->vid_list, + &vlan_info->vid_list, list) { vlan_vid_del(dev, vid_info->vid); } @@ -355,13 +357,15 @@ void vlan_vids_del_by_dev(struct net_device *dev, const struct net_device *by_dev) { struct vlan_vid_info *vid_info; + struct vlan_info *vlan_info; ASSERT_RTNL(); - if (!by_dev->vlan_info) + vlan_info = rtnl_dereference(by_dev->vlan_info); + if (!vlan_info) return; - list_for_each_entry(vid_info, &by_dev->vlan_info->vid_list, list) + list_for_each_entry(vid_info, &vlan_info->vid_list, list) vlan_vid_del(dev, vid_info->vid); } EXPORT_SYMBOL(vlan_vids_del_by_dev);