Commit 3727f742 authored by Yang Yingliang's avatar Yang Yingliang Committed by David S. Miller
Browse files

hamradio: don't call dev_kfree_skb() under spin_lock_irqsave() 



It is not allowed to call kfree_skb() or consume_skb() from hardware
interrupt context or with hardware interrupts being disabled.

It should use dev_kfree_skb_irq() or dev_consume_skb_irq() instead.
The difference between them is free reason, dev_kfree_skb_irq() means
the SKB is dropped in error and dev_consume_skb_irq() means the SKB
is consumed in normal.

In scc_discard_buffers(), dev_kfree_skb() is called to discard the SKBs,
so replace it with dev_kfree_skb_irq().

In scc_net_tx(), dev_kfree_skb() is called to drop the SKB that exceed
queue length, so replace it with dev_kfree_skb_irq().

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f07fadcb

drivers/net/hamradio/scc.c

+3 −3
Original line number Diff line number Diff line
@@ -302,12 +302,12 @@ static inline void scc_discard_buffers(struct scc_channel *scc) 
	spin_lock_irqsave(&scc->lock, flags);	

	if (scc->tx_buff != NULL)

	{

		dev_kfree_skb(scc->tx_buff);

		dev_kfree_skb_irq(scc->tx_buff);

		scc->tx_buff = NULL;

	}

	

	while (!skb_queue_empty(&scc->tx_queue))

		dev_kfree_skb(skb_dequeue(&scc->tx_queue));

		dev_kfree_skb_irq(skb_dequeue(&scc->tx_queue));



	spin_unlock_irqrestore(&scc->lock, flags);

}
@@ -1668,7 +1668,7 @@ static netdev_tx_t scc_net_tx(struct sk_buff *skb, struct net_device *dev) 
	if (skb_queue_len(&scc->tx_queue) > scc->dev->tx_queue_len) {

		struct sk_buff *skb_del;

		skb_del = skb_dequeue(&scc->tx_queue);

		dev_kfree_skb(skb_del);

		dev_kfree_skb_irq(skb_del);

	}

	skb_queue_tail(&scc->tx_queue, skb);

	netif_trans_update(dev);