Re: [PATCH] Networking: Core: netpoll: Fixed a missing spin_unlock

[Francois Romieu]

Salil Kapur  :
> I was looking at v3.12. Can we submit patches for stable versions?

It has already been fixed in 3.12.8 as 56399d8b44beae5b80e1eda0350ab6af72baf4d0
("netpoll: Fix missing TXQ unlock and and OOPS.") by davem.

3.12.8 dates back to 2014/01. The current 3.12.x version is 3.12.62.

-- 
Ueimor

Re: [PATCH] Networking: Core: netpoll: Fixed a missing spin_unlock

[Francois Romieu]

Salil Kapur  :
[...]
> diff --git a/net/core/netpoll.c b/net/core/netpoll.c
> index fc75c9e..9124f76 100644
> --- a/net/core/netpoll.c
> +++ b/net/core/netpoll.c
> @@ -386,8 +386,10 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct 
> sk_buff *skb,
>   
> !vlan_hw_offload_capable(netif_skb_features(skb),
>
> skb->vlan_proto)) {
>   skb = __vlan_put_tag(skb, 
> skb->vlan_proto, vlan_tx_tag_get(skb));
> - if (unlikely(!skb))
> + if (unlikely(!skb)) {
> + __netif_tx_unlock(txq);
>   break;
> + }
>   skb->vlan_tci = 0;
>   }
>  

Your kernel is outdated: __vlan_put_tag has disappeared from net/core/netpoll.c
since 62749e2cb3c4a7da3eaa5c01a7e787aebeff8536 ("vlan: rename __vlan_put_tag to
vlan_insert_tag_set_proto") by Jiri Pirko somewhere in 2014.

-- 
Ueimor

[PATCH] Networking: Core: netpoll: Fixed a missing spin_unlock

[Salil Kapur]

In the case when the loop breaks at line 390, the txq lock is not
released. Added an unlock statement before the break statement.

Signed-off-by: Salil Kapur 
---
 net/core/netpoll.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index fc75c9e..9124f76 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -386,8 +386,10 @@ void netpoll_send_skb_on_dev(struct netpoll *np, struct 
sk_buff *skb,

!vlan_hw_offload_capable(netif_skb_features(skb),
 
skb->vlan_proto)) {
skb = __vlan_put_tag(skb, 
skb->vlan_proto, vlan_tx_tag_get(skb));
-   if (unlikely(!skb))
+   if (unlikely(!skb)) {
+   __netif_tx_unlock(txq);
break;
+   }
skb->vlan_tci = 0;
}
 
-- 
1.9.1