Re: [PATCH net-next] xen-netback: only deinitialized hash if it was initialized

[David Miller]

From: Paul Durrant 
Date: Wed, 18 May 2016 15:55:42 +0100

> A domain with a frontend that does not implement a control ring has been
> seen to cause a crash during domain save. This was apparently because
> the call to xenvif_deinit_hash() in xenvif_disconnect_ctrl() is made
> regardless of whether a control ring was connected, and hence
> xenvif_hash_init() was called.
> 
> This patch brings the call to xenvif_deinit_hash() in
> xenvif_disconnect_ctrl() inside the if clause that checks whether the
> control ring event channel was connected. This is sufficient to ensure
> it is only called if xenvif_init_hash() was called previously.
> 
> Signed-off-by: Paul Durrant 
> Reported-by: Boris Ostrovsky 
> Tested-by: Boris Ostrovsky 

Applied, thanks.

Re: [PATCH net-next] xen-netback: only deinitialized hash if it was initialized

[Wei Liu]

On Wed, May 18, 2016 at 03:55:42PM +0100, Paul Durrant wrote:
> A domain with a frontend that does not implement a control ring has been
> seen to cause a crash during domain save. This was apparently because
> the call to xenvif_deinit_hash() in xenvif_disconnect_ctrl() is made
> regardless of whether a control ring was connected, and hence
> xenvif_hash_init() was called.
> 
> This patch brings the call to xenvif_deinit_hash() in
> xenvif_disconnect_ctrl() inside the if clause that checks whether the
> control ring event channel was connected. This is sufficient to ensure
> it is only called if xenvif_init_hash() was called previously.
> 
> Signed-off-by: Paul Durrant 
> Reported-by: Boris Ostrovsky 
> Tested-by: Boris Ostrovsky 
> Cc: Wei Liu 

Acked-by: Wei Liu 

> ---
>  drivers/net/xen-netback/interface.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/net/xen-netback/interface.c 
> b/drivers/net/xen-netback/interface.c
> index 1c7f49b..83deeeb 100644
> --- a/drivers/net/xen-netback/interface.c
> +++ b/drivers/net/xen-netback/interface.c
> @@ -780,9 +780,8 @@ void xenvif_disconnect_ctrl(struct xenvif *vif)
>   vif->ctrl_task = NULL;
>   }
>  
> - xenvif_deinit_hash(vif);
> -
>   if (vif->ctrl_irq) {
> + xenvif_deinit_hash(vif);
>   unbind_from_irqhandler(vif->ctrl_irq, vif);
>   vif->ctrl_irq = 0;
>   }
> -- 
> 2.1.4
> 

[PATCH net-next] xen-netback: only deinitialized hash if it was initialized

[Paul Durrant]

A domain with a frontend that does not implement a control ring has been
seen to cause a crash during domain save. This was apparently because
the call to xenvif_deinit_hash() in xenvif_disconnect_ctrl() is made
regardless of whether a control ring was connected, and hence
xenvif_hash_init() was called.

This patch brings the call to xenvif_deinit_hash() in
xenvif_disconnect_ctrl() inside the if clause that checks whether the
control ring event channel was connected. This is sufficient to ensure
it is only called if xenvif_init_hash() was called previously.

Signed-off-by: Paul Durrant 
Reported-by: Boris Ostrovsky 
Tested-by: Boris Ostrovsky 
Cc: Wei Liu 
---
 drivers/net/xen-netback/interface.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/xen-netback/interface.c 
b/drivers/net/xen-netback/interface.c
index 1c7f49b..83deeeb 100644
--- a/drivers/net/xen-netback/interface.c
+++ b/drivers/net/xen-netback/interface.c
@@ -780,9 +780,8 @@ void xenvif_disconnect_ctrl(struct xenvif *vif)
vif->ctrl_task = NULL;
}
 
-   xenvif_deinit_hash(vif);
-
if (vif->ctrl_irq) {
+   xenvif_deinit_hash(vif);
unbind_from_irqhandler(vif->ctrl_irq, vif);
vif->ctrl_irq = 0;
}
-- 
2.1.4