Wed, Dec 14, 2011 at 07:29:43AM CET, dan.carpenter@xxxxxxxxxx wrote:
>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 <dan.carpenter@xxxxxxxxxx>
>---
>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);
Acked-by: Jiri Pirko <jpirko@xxxxxxxxxx>
Thanks Dan!
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