br_forward.c - rcu dereference warning

br_forward.c - rcu dereference warning

[Johannes Berg]

I couldn't find this reported yet, apologies if I missed it.

johannes

[   60.140433] ===================================================
[   60.140437] [ INFO: suspicious rcu_dereference_check() usage. ]
[   60.140440] ---------------------------------------------------
[   60.140444] /home/johannes/sys/wireless-testing/net/bridge/br_forward.c:215 invoked rcu_dereference_check() without protection!
[   60.140447] 
[   60.140448] other info that might help us debug this:
[   60.140449] 
[   60.140452] 
[   60.140453] rcu_scheduler_active = 1, debug_locks = 1
[   60.140457] 2 locks held by Xorg/3083:
[   60.140459]  #0:  (&im->timer){+.-...}, at: [<ffffffff81058180>] call_timer_fn+0x0/0x2f0
[   60.140473]  #1:  (rcu_read_lock_bh){.+....}, at: [<ffffffff813b6c3a>] dev_queue_xmit+0x5a/0x690
[   60.140484] 
[   60.140484] stack backtrace:
[   60.140489] Pid: 3083, comm: Xorg Not tainted 2.6.35-rc6-wl-47665-gc2e2180-dirty #174
[   60.140492] Call Trace:
[   60.140495]  <IRQ>  [<ffffffff8107e494>] lockdep_rcu_dereference+0xa4/0xc0
[   60.140514]  [<ffffffffa07617c3>] br_multicast_flood+0x293/0x310 [bridge]
[   60.140531]  [<ffffffffa0761877>] br_multicast_deliver+0x17/0x20 [bridge]
[   60.140539]  [<ffffffffa07607bc>] br_dev_xmit+0x10c/0x170 [bridge]
[   60.140550]  [<ffffffff813b69ba>] dev_hard_start_xmit+0x21a/0x2e0
[   60.140556]  [<ffffffff813b708e>] dev_queue_xmit+0x4ae/0x690
[   60.140576]  [<ffffffff813c0d43>] neigh_resolve_output+0x113/0x250
[   60.140582]  [<ffffffff813eec46>] ip_finish_output+0x2a6/0x570
[   60.140588]  [<ffffffff813ef33c>] ip_mc_output+0x1dc/0x320
[   60.140593]  [<ffffffff813ed7ed>] ip_local_out+0x2d/0x80
[   60.140600]  [<ffffffff81422236>] igmp_send_report+0x1c6/0x200
[   60.140610]  [<ffffffff814238f0>] igmp_timer_expire+0x100/0x130
[   60.140615]  [<ffffffff81058219>] call_timer_fn+0x99/0x2f0
[   60.140636]  [<ffffffff810585e3>] run_timer_softirq+0x173/0x330
[   60.140641]  [<ffffffff8104f114>] __do_softirq+0x114/0x3d0
[   60.140652]  [<ffffffff8100360c>] call_softirq+0x1c/0x50

Re: br_forward.c - rcu dereference warning

[Paul E. McKenney]

On Tue, Jul 27, 2010 at 12:45:53PM +0200, Johannes Berg wrote:
> I couldn't find this reported yet, apologies if I missed it.

My first guess is that the call to br_multicast_deliver() in
br_dev_xmit() needs to be enclosed in rcu_read_lock(), but I have
to defer to someone who knows the code better.  Another possible
fix would be to change the rcu_dereference() in br_multicast_flood()
to rcu_dereference_bh(), for example.

						Thanx, Paul

> johannes
> 
> [   60.140433] ===================================================
> [   60.140437] [ INFO: suspicious rcu_dereference_check() usage. ]
> [   60.140440] ---------------------------------------------------
> [   60.140444] /home/johannes/sys/wireless-testing/net/bridge/br_forward.c:215 invoked rcu_dereference_check() without protection!
> [   60.140447] 
> [   60.140448] other info that might help us debug this:
> [   60.140449] 
> [   60.140452] 
> [   60.140453] rcu_scheduler_active = 1, debug_locks = 1
> [   60.140457] 2 locks held by Xorg/3083:
> [   60.140459]  #0:  (&im->timer){+.-...}, at: [<ffffffff81058180>] call_timer_fn+0x0/0x2f0
> [   60.140473]  #1:  (rcu_read_lock_bh){.+....}, at: [<ffffffff813b6c3a>] dev_queue_xmit+0x5a/0x690
> [   60.140484] 
> [   60.140484] stack backtrace:
> [   60.140489] Pid: 3083, comm: Xorg Not tainted 2.6.35-rc6-wl-47665-gc2e2180-dirty #174
> [   60.140492] Call Trace:
> [   60.140495]  <IRQ>  [<ffffffff8107e494>] lockdep_rcu_dereference+0xa4/0xc0
> [   60.140514]  [<ffffffffa07617c3>] br_multicast_flood+0x293/0x310 [bridge]
> [   60.140531]  [<ffffffffa0761877>] br_multicast_deliver+0x17/0x20 [bridge]
> [   60.140539]  [<ffffffffa07607bc>] br_dev_xmit+0x10c/0x170 [bridge]
> [   60.140550]  [<ffffffff813b69ba>] dev_hard_start_xmit+0x21a/0x2e0
> [   60.140556]  [<ffffffff813b708e>] dev_queue_xmit+0x4ae/0x690
> [   60.140576]  [<ffffffff813c0d43>] neigh_resolve_output+0x113/0x250
> [   60.140582]  [<ffffffff813eec46>] ip_finish_output+0x2a6/0x570
> [   60.140588]  [<ffffffff813ef33c>] ip_mc_output+0x1dc/0x320
> [   60.140593]  [<ffffffff813ed7ed>] ip_local_out+0x2d/0x80
> [   60.140600]  [<ffffffff81422236>] igmp_send_report+0x1c6/0x200
> [   60.140610]  [<ffffffff814238f0>] igmp_timer_expire+0x100/0x130
> [   60.140615]  [<ffffffff81058219>] call_timer_fn+0x99/0x2f0
> [   60.140636]  [<ffffffff810585e3>] run_timer_softirq+0x173/0x330
> [   60.140641]  [<ffffffff8104f114>] __do_softirq+0x114/0x3d0
> [   60.140652]  [<ffffffff8100360c>] call_softirq+0x1c/0x50
> 
> 
> --
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> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: br_forward.c - rcu dereference warning

[Stephen Hemminger]

I think this is needed (untested)...
-----
Subject: bridge: add rcu_read_lock on transmit

Long ago, when bridge was converted to RCU, rcu lock was equivalent
to having preempt disabled. RCU has changed a lot since then and
bridge code was still assuming the since transmit was called with
bottom half disabled, it was RCU safe.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>


---
 net/bridge/br_device.c   |    4 +++-
 net/bridge/br_fdb.c      |    2 +-
 net/bridge/br_input.c    |    7 +++----
 net/bridge/br_stp_bpdu.c |    2 +-
 4 files changed, 8 insertions(+), 7 deletions(-)

--- a/net/bridge/br_device.c	2010-07-27 08:57:43.169399349 -0700
+++ b/net/bridge/br_device.c	2010-07-27 11:18:51.677053426 -0700
@@ -22,7 +22,7 @@
 #include <asm/uaccess.h>
 #include "br_private.h"
 
-/* net device transmit always called with no BH (preempt_disabled) */
+/* net device transmit always called with no BH disabled */
 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct net_bridge *br = netdev_priv(dev);
@@ -48,6 +48,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *
 	skb_reset_mac_header(skb);
 	skb_pull(skb, ETH_HLEN);
 
+	rcu_read_lock();
 	if (is_multicast_ether_addr(dest)) {
 		if (unlikely(netpoll_tx_running(dev))) {
 			br_flood_deliver(br, skb);
@@ -67,6 +68,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *
 		br_flood_deliver(br, skb);
 
 out:
+	rcu_read_unlock();
 	return NETDEV_TX_OK;
 }
 
--- a/net/bridge/br_fdb.c	2010-07-27 11:18:30.815320981 -0700
+++ b/net/bridge/br_fdb.c	2010-07-27 11:18:59.597710975 -0700
@@ -214,7 +214,7 @@ void br_fdb_delete_by_port(struct net_br
 	spin_unlock_bh(&br->hash_lock);
 }
 
-/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
+/* No locking or refcounting, assumes caller has rcu_read_lock */
 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 					  const unsigned char *addr)
 {
--- a/net/bridge/br_input.c	2010-07-27 11:19:05.266181492 -0700
+++ b/net/bridge/br_input.c	2010-07-27 11:19:29.148163149 -0700
@@ -39,7 +39,7 @@ static int br_pass_frame_up(struct sk_bu
 		       netif_receive_skb);
 }
 
-/* note: already called with rcu_read_lock (preempt_disabled) */
+/* note: already called with rcu_read_lock */
 int br_handle_frame_finish(struct sk_buff *skb)
 {
 	const unsigned char *dest = eth_hdr(skb)->h_dest;
@@ -110,7 +110,7 @@ drop:
 	goto out;
 }
 
-/* note: already called with rcu_read_lock (preempt_disabled) */
+/* note: already called with rcu_read_lock */
 static int br_handle_local_finish(struct sk_buff *skb)
 {
 	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
@@ -133,8 +133,7 @@ static inline int is_link_local(const un
 
 /*
  * Return NULL if skb is handled
- * note: already called with rcu_read_lock (preempt_disabled) from
- * netif_receive_skb
+ * note: already called with rcu_read_lock from netif_receive_skb
  */
 struct sk_buff *br_handle_frame(struct sk_buff *skb)
 {
--- a/net/bridge/br_stp_bpdu.c	2010-07-27 11:19:34.092573294 -0700
+++ b/net/bridge/br_stp_bpdu.c	2010-07-27 11:19:40.725123403 -0700
@@ -131,7 +131,7 @@ void br_send_tcn_bpdu(struct net_bridge_
 /*
  * Called from llc.
  *
- * NO locks, but rcu_read_lock (preempt_disabled)
+ * NO locks, but rcu_read_lock
  */
 void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
 		struct net_device *dev)

Re: br_forward.c - rcu dereference warning

[Johannes Berg]

On Tue, 2010-07-27 at 11:26 -0700, Stephen Hemminger wrote:

> -/* net device transmit always called with no BH (preempt_disabled) */
> +/* net device transmit always called with no BH disabled */

"no BH disabled"?

> @@ -48,6 +48,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *
>  	skb_reset_mac_header(skb);
>  	skb_pull(skb, ETH_HLEN);
>  
> +	rcu_read_lock();
>  	if (is_multicast_ether_addr(dest)) {
>  		if (unlikely(netpoll_tx_running(dev))) {
>  			br_flood_deliver(br, skb);
> @@ -67,6 +68,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *
>  		br_flood_deliver(br, skb);
>  
>  out:
> +	rcu_read_unlock();
>  	return NETDEV_TX_OK;
>  }
>  
> --- a/net/bridge/br_fdb.c	2010-07-27 11:18:30.815320981 -0700
> +++ b/net/bridge/br_fdb.c	2010-07-27 11:18:59.597710975 -0700
> @@ -214,7 +214,7 @@ void br_fdb_delete_by_port(struct net_br
>  	spin_unlock_bh(&br->hash_lock);
>  }
>  
> -/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
> +/* No locking or refcounting, assumes caller has rcu_read_lock */
>  struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
>  					  const unsigned char *addr)
>  {
> --- a/net/bridge/br_input.c	2010-07-27 11:19:05.266181492 -0700
> +++ b/net/bridge/br_input.c	2010-07-27 11:19:29.148163149 -0700
> @@ -39,7 +39,7 @@ static int br_pass_frame_up(struct sk_bu
>  		       netif_receive_skb);
>  }
>  
> -/* note: already called with rcu_read_lock (preempt_disabled) */
> +/* note: already called with rcu_read_lock */
>  int br_handle_frame_finish(struct sk_buff *skb)
>  {
>  	const unsigned char *dest = eth_hdr(skb)->h_dest;
> @@ -110,7 +110,7 @@ drop:
>  	goto out;
>  }
>  
> -/* note: already called with rcu_read_lock (preempt_disabled) */
> +/* note: already called with rcu_read_lock */
>  static int br_handle_local_finish(struct sk_buff *skb)
>  {
>  	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
> @@ -133,8 +133,7 @@ static inline int is_link_local(const un
>  
>  /*
>   * Return NULL if skb is handled
> - * note: already called with rcu_read_lock (preempt_disabled) from
> - * netif_receive_skb
> + * note: already called with rcu_read_lock from netif_receive_skb
>   */
>  struct sk_buff *br_handle_frame(struct sk_buff *skb)
>  {
> --- a/net/bridge/br_stp_bpdu.c	2010-07-27 11:19:34.092573294 -0700
> +++ b/net/bridge/br_stp_bpdu.c	2010-07-27 11:19:40.725123403 -0700
> @@ -131,7 +131,7 @@ void br_send_tcn_bpdu(struct net_bridge_
>  /*
>   * Called from llc.
>   *
> - * NO locks, but rcu_read_lock (preempt_disabled)
> + * NO locks, but rcu_read_lock
>   */
>  void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
>  		struct net_device *dev)
> 

Did you want me to test the patch?

johannes

Re: br_forward.c - rcu dereference warning

[Stephen Hemminger]

On Tue, 27 Jul 2010 22:14:39 +0200
Johannes Berg <johannes@sipsolutions.net> wrote:

> On Tue, 2010-07-27 at 11:26 -0700, Stephen Hemminger wrote:
> 
> > -/* net device transmit always called with no BH (preempt_disabled) */
> > +/* net device transmit always called with no BH disabled */
> 
> "no BH disabled"?
> 
> > @@ -48,6 +48,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *
> >  	skb_reset_mac_header(skb);
> >  	skb_pull(skb, ETH_HLEN);
> >  
> > +	rcu_read_lock();
> >  	if (is_multicast_ether_addr(dest)) {
> >  		if (unlikely(netpoll_tx_running(dev))) {
> >  			br_flood_deliver(br, skb);
> > @@ -67,6 +68,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *
> >  		br_flood_deliver(br, skb);
> >  
> >  out:
> > +	rcu_read_unlock();
> >  	return NETDEV_TX_OK;
> >  }
> >  
> > --- a/net/bridge/br_fdb.c	2010-07-27 11:18:30.815320981 -0700
> > +++ b/net/bridge/br_fdb.c	2010-07-27 11:18:59.597710975 -0700
> > @@ -214,7 +214,7 @@ void br_fdb_delete_by_port(struct net_br
> >  	spin_unlock_bh(&br->hash_lock);
> >  }
> >  
> > -/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
> > +/* No locking or refcounting, assumes caller has rcu_read_lock */
> >  struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
> >  					  const unsigned char *addr)
> >  {
> > --- a/net/bridge/br_input.c	2010-07-27 11:19:05.266181492 -0700
> > +++ b/net/bridge/br_input.c	2010-07-27 11:19:29.148163149 -0700
> > @@ -39,7 +39,7 @@ static int br_pass_frame_up(struct sk_bu
> >  		       netif_receive_skb);
> >  }
> >  
> > -/* note: already called with rcu_read_lock (preempt_disabled) */
> > +/* note: already called with rcu_read_lock */
> >  int br_handle_frame_finish(struct sk_buff *skb)
> >  {
> >  	const unsigned char *dest = eth_hdr(skb)->h_dest;
> > @@ -110,7 +110,7 @@ drop:
> >  	goto out;
> >  }
> >  
> > -/* note: already called with rcu_read_lock (preempt_disabled) */
> > +/* note: already called with rcu_read_lock */
> >  static int br_handle_local_finish(struct sk_buff *skb)
> >  {
> >  	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
> > @@ -133,8 +133,7 @@ static inline int is_link_local(const un
> >  
> >  /*
> >   * Return NULL if skb is handled
> > - * note: already called with rcu_read_lock (preempt_disabled) from
> > - * netif_receive_skb
> > + * note: already called with rcu_read_lock from netif_receive_skb
> >   */
> >  struct sk_buff *br_handle_frame(struct sk_buff *skb)
> >  {
> > --- a/net/bridge/br_stp_bpdu.c	2010-07-27 11:19:34.092573294 -0700
> > +++ b/net/bridge/br_stp_bpdu.c	2010-07-27 11:19:40.725123403 -0700
> > @@ -131,7 +131,7 @@ void br_send_tcn_bpdu(struct net_bridge_
> >  /*
> >   * Called from llc.
> >   *
> > - * NO locks, but rcu_read_lock (preempt_disabled)
> > + * NO locks, but rcu_read_lock
> >   */
> >  void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
> >  		struct net_device *dev)
> > 
> 
> Did you want me to test the patch?

Yes please, I can make sure it works, but not that it gets rid
of your error

-- 

Re: br_forward.c - rcu dereference warning

[Johannes Berg]

On Tue, 2010-07-27 at 13:42 -0700, Stephen Hemminger wrote:

> > Did you want me to test the patch?
> 
> Yes please, I can make sure it works, but not that it gets rid
> of your error

Testing now, but it didn't quite apply cleanly on 2.6.35-rc.

johannes

Re: br_forward.c - rcu dereference warning

[Johannes Berg]

On Tue, 2010-07-27 at 13:42 -0700, Stephen Hemminger wrote:

> > 
> > Did you want me to test the patch?
> 
> Yes please, I can make sure it works, but not that it gets rid
> of your error

Yes, it fixed it, thanks.

johannes

[PATCH] bridge: add rcu_read_lock

[Stephen Hemminger]

Long ago, when bridge was converted to RCU, rcu lock was equivalent
to having preempt disabled. RCU has changed a lot since then and
bridge code was still assuming the since transmit was called with
bottom half disabled, it was RCU safe.

In addition to fixing the code, update the comments about
locking to match current state as well.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>


---
 net/bridge/br_device.c   |    4 +++-
 net/bridge/br_fdb.c      |    2 +-
 net/bridge/br_input.c    |    7 +++----
 net/bridge/br_stp_bpdu.c |    2 +-
 4 files changed, 8 insertions(+), 7 deletions(-)

--- a/net/bridge/br_device.c	2010-07-27 08:57:43.169399349 -0700
+++ b/net/bridge/br_device.c	2010-07-27 13:57:20.278665500 -0700
@@ -22,7 +22,7 @@
 #include <asm/uaccess.h>
 #include "br_private.h"
 
-/* net device transmit always called with no BH (preempt_disabled) */
+/* net device transmit always called with BH disabled */
 netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 {
 	struct net_bridge *br = netdev_priv(dev);
@@ -48,6 +48,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *
 	skb_reset_mac_header(skb);
 	skb_pull(skb, ETH_HLEN);
 
+	rcu_read_lock();
 	if (is_multicast_ether_addr(dest)) {
 		if (unlikely(netpoll_tx_running(dev))) {
 			br_flood_deliver(br, skb);
@@ -67,6 +68,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *
 		br_flood_deliver(br, skb);
 
 out:
+	rcu_read_unlock();
 	return NETDEV_TX_OK;
 }
 
--- a/net/bridge/br_fdb.c	2010-07-27 11:18:30.815320981 -0700
+++ b/net/bridge/br_fdb.c	2010-07-27 11:18:59.597710975 -0700
@@ -214,7 +214,7 @@ void br_fdb_delete_by_port(struct net_br
 	spin_unlock_bh(&br->hash_lock);
 }
 
-/* No locking or refcounting, assumes caller has no preempt (rcu_read_lock) */
+/* No locking or refcounting, assumes caller has rcu_read_lock */
 struct net_bridge_fdb_entry *__br_fdb_get(struct net_bridge *br,
 					  const unsigned char *addr)
 {
--- a/net/bridge/br_input.c	2010-07-27 11:19:05.266181492 -0700
+++ b/net/bridge/br_input.c	2010-07-27 11:19:29.148163149 -0700
@@ -39,7 +39,7 @@ static int br_pass_frame_up(struct sk_bu
 		       netif_receive_skb);
 }
 
-/* note: already called with rcu_read_lock (preempt_disabled) */
+/* note: already called with rcu_read_lock */
 int br_handle_frame_finish(struct sk_buff *skb)
 {
 	const unsigned char *dest = eth_hdr(skb)->h_dest;
@@ -110,7 +110,7 @@ drop:
 	goto out;
 }
 
-/* note: already called with rcu_read_lock (preempt_disabled) */
+/* note: already called with rcu_read_lock */
 static int br_handle_local_finish(struct sk_buff *skb)
 {
 	struct net_bridge_port *p = br_port_get_rcu(skb->dev);
@@ -133,8 +133,7 @@ static inline int is_link_local(const un
 
 /*
  * Return NULL if skb is handled
- * note: already called with rcu_read_lock (preempt_disabled) from
- * netif_receive_skb
+ * note: already called with rcu_read_lock from netif_receive_skb
  */
 struct sk_buff *br_handle_frame(struct sk_buff *skb)
 {
--- a/net/bridge/br_stp_bpdu.c	2010-07-27 11:19:34.092573294 -0700
+++ b/net/bridge/br_stp_bpdu.c	2010-07-27 11:19:40.725123403 -0700
@@ -131,7 +131,7 @@ void br_send_tcn_bpdu(struct net_bridge_
 /*
  * Called from llc.
  *
- * NO locks, but rcu_read_lock (preempt_disabled)
+ * NO locks, but rcu_read_lock
  */
 void br_stp_rcv(const struct stp_proto *proto, struct sk_buff *skb,
 		struct net_device *dev)

Re: [PATCH] bridge: add rcu_read_lock

[David Miller]

From: Stephen Hemminger <shemminger@vyatta.com>
Date: Wed, 28 Jul 2010 09:57:30 -0700

> Long ago, when bridge was converted to RCU, rcu lock was equivalent
> to having preempt disabled. RCU has changed a lot since then and
> bridge code was still assuming the since transmit was called with
> bottom half disabled, it was RCU safe.
> 
> In addition to fixing the code, update the comments about
> locking to match current state as well.
> 
> Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>

As I stated in another email I added the original commit.

This version still didn't apply to net-2.6 and also you failed
to add a tested-by tag for Johannes to the commit message, which
I also did alongside backporting the original patch to net-2.6

Re: [PATCH] bridge: add rcu_read_lock

[Stephen Hemminger]

On Wed, 28 Jul 2010 10:52:09 -0700 (PDT)
David Miller <davem@davemloft.net> wrote:

> From: Stephen Hemminger <shemminger@vyatta.com>
> Date: Wed, 28 Jul 2010 09:57:30 -0700
> 
> > Long ago, when bridge was converted to RCU, rcu lock was equivalent
> > to having preempt disabled. RCU has changed a lot since then and
> > bridge code was still assuming the since transmit was called with
> > bottom half disabled, it was RCU safe.
> > 
> > In addition to fixing the code, update the comments about
> > locking to match current state as well.
> > 
> > Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
> 
> As I stated in another email I added the original commit.
> 
> This version still didn't apply to net-2.6 and also you failed
> to add a tested-by tag for Johannes to the commit message, which
> I also did alongside backporting the original patch to net-2.6

I didn't see yours, if you look at the date it was ships in the night.


-- 

Re: br_forward.c - rcu dereference warning

[David Miller]

From: Johannes Berg <johannes@sipsolutions.net>
Date: Wed, 28 Jul 2010 09:33:51 +0200

> On Tue, 2010-07-27 at 13:42 -0700, Stephen Hemminger wrote:
> 
>> > 
>> > Did you want me to test the patch?
>> 
>> Yes please, I can make sure it works, but not that it gets rid
>> of your error
> 
> Yes, it fixed it, thanks.

I fixed up the comment thinko Johannes noticed, added a tested-by tag,
and applied this to net-2.6

Thanks!