Re: [PATCH] net: init ingress queue

[Eric Dumazet <eric.dumazet@gmail.com>]

Le samedi 04 décembre 2010 à 13:45 +0800, Changli Gao a écrit :
> The dev field of ingress queue is forgot to initialized, then NULL
> pointer dereference happens in qdisc_alloc().

< deleted oops >

> Signed-off-by: Changli Gao <xiaosuo@gmail.com>
> ---
>  net/core/dev.c |    2 ++
>  1 file changed, 2 insertions(+)
> diff --git a/net/core/dev.c b/net/core/dev.c
> index cd24374..8083c68 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -5577,6 +5577,8 @@ struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
>  	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
>  	if (!queue)
>  		return NULL;
> +	netdev_queue_numa_node_write(queue, -1);
> +	queue->dev = dev;
>  	netdev_init_one_queue(dev, queue, NULL);
>  	queue->qdisc = &noop_qdisc;
>  	queue->qdisc_sleeping = &noop_qdisc;

Hi Changli, thanks for bug report and patch.

IMHO there is no point to include this long Oops report in Changelog for
a net-next-2.6 temporary problem, there wont be any bugzilla report. 

Instead, you could say it is a followup patch for commits 1d24eb4815d1e0
and f2cd2d3e9b3ef960. Two or three lines with relevant information.

I suggest you submit following patch instead, as this seems cleaner to
me ?

(factorize the two inits in netdev_init_one_queue())


diff --git a/net/core/dev.c b/net/core/dev.c
index cd24374..36e10b4 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5113,7 +5113,6 @@ static int netif_alloc_netdev_queues(struct net_device *dev)
 {
 	unsigned int count = dev->num_tx_queues;
 	struct netdev_queue *tx;
-	int i;
 
 	BUG_ON(count < 1);
 
@@ -5125,10 +5124,6 @@ static int netif_alloc_netdev_queues(struct net_device *dev)
 	}
 	dev->_tx = tx;
 
-	for (i = 0; i < count; i++) {
-		netdev_queue_numa_node_write(&tx[i], -1);
-		tx[i].dev = dev;
-	}
 	return 0;
 }
 
@@ -5140,6 +5135,8 @@ static void netdev_init_one_queue(struct net_device *dev,
 	spin_lock_init(&queue->_xmit_lock);
 	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
 	queue->xmit_lock_owner = -1;
+	netdev_queue_numa_node_write(queue, -1);
+	queue->dev = dev;
 }
 
 static void netdev_init_queues(struct net_device *dev)