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);
--
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