* [patch] vlan: add rtnl_dereference() annotations
@ 2011-12-14 6:29 Dan Carpenter
2011-12-14 7:01 ` Eric Dumazet
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: Dan Carpenter @ 2011-12-14 6:29 UTC (permalink / raw)
To: Patrick McHardy; +Cc: David S. Miller, netdev, kernel-janitors, 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 <dan.carpenter@oracle.com>
---
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);
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [patch] vlan: add rtnl_dereference() annotations
2011-12-14 6:29 [patch] vlan: add rtnl_dereference() annotations Dan Carpenter
@ 2011-12-14 7:01 ` Eric Dumazet
2011-12-14 7:34 ` Jiri Pirko
2011-12-14 7:47 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Eric Dumazet @ 2011-12-14 7:01 UTC (permalink / raw)
To: Dan Carpenter
Cc: Patrick McHardy, David S. Miller, netdev, kernel-janitors,
Jiri Pirko
Le mercredi 14 décembre 2011 à 09:29 +0300, Dan Carpenter a écrit :
> 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@oracle.com>
> ---
> I haven't tested this, and I'm not super familiar with this code.
> Please review it carefully.
>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [patch] vlan: add rtnl_dereference() annotations
2011-12-14 6:29 [patch] vlan: add rtnl_dereference() annotations Dan Carpenter
2011-12-14 7:01 ` Eric Dumazet
@ 2011-12-14 7:34 ` Jiri Pirko
2011-12-14 7:47 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Jiri Pirko @ 2011-12-14 7:34 UTC (permalink / raw)
To: Dan Carpenter; +Cc: Patrick McHardy, David S. Miller, netdev, kernel-janitors
Wed, Dec 14, 2011 at 07:29:43AM CET, dan.carpenter@oracle.com 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@oracle.com>
>---
>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@redhat.com>
Thanks Dan!
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [patch] vlan: add rtnl_dereference() annotations
2011-12-14 6:29 [patch] vlan: add rtnl_dereference() annotations Dan Carpenter
2011-12-14 7:01 ` Eric Dumazet
2011-12-14 7:34 ` Jiri Pirko
@ 2011-12-14 7:47 ` David Miller
2 siblings, 0 replies; 4+ messages in thread
From: David Miller @ 2011-12-14 7:47 UTC (permalink / raw)
To: dan.carpenter; +Cc: kaber, netdev, kernel-janitors, jpirko
From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Wed, 14 Dec 2011 09:29:43 +0300
> 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@oracle.com>
Applied.
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2011-12-14 7:48 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-12-14 6:29 [patch] vlan: add rtnl_dereference() annotations Dan Carpenter
2011-12-14 7:01 ` Eric Dumazet
2011-12-14 7:34 ` Jiri Pirko
2011-12-14 7:47 ` David Miller
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).