From 22580f894ac190c46beebb5c3172e450a2318f79 Mon Sep 17 00:00:00 2001 From: Dongdong Deng Date: Thu, 13 Aug 2009 19:12:31 +0000 Subject: drivers/net: fixed drivers that support netpoll use ndo_start_xmit() The NETPOLL API requires that interrupts remain disabled in netpoll_send_skb(). The use of spin_lock_irq() and spin_unlock_irq() in the NETPOLL API callbacks causes the interrupts to get enabled and can lead to kernel instability. The solution is to use spin_lock_irqsave() and spin_unlock_restore() to prevent the irqs from getting enabled while in netpoll_send_skb(). Call trace: netpoll_send_skb() { -> local_irq_save(flags) ---> dev->ndo_start_xmit(skb, dev) ---> spin_lock_irq() ---> spin_unlock_irq() *******here would enable the interrupt. ... -> local_irq_restore(flags) } Signed-off-by: Dongdong Deng Signed-off-by: Jason Wessel Acked-by: Bruce Ashfield Acked-by: Matt Mackall Signed-off-by: David S. Miller --- drivers/net/b44.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/net/b44.c') diff --git a/drivers/net/b44.c b/drivers/net/b44.c index 36d4d37..bafca67 100644 --- a/drivers/net/b44.c +++ b/drivers/net/b44.c @@ -952,9 +952,10 @@ static int b44_start_xmit(struct sk_buff *skb, struct net_device *dev) int rc = NETDEV_TX_OK; dma_addr_t mapping; u32 len, entry, ctrl; + unsigned long flags; len = skb->len; - spin_lock_irq(&bp->lock); + spin_lock_irqsave(&bp->lock, flags); /* This is a hard error, log it. */ if (unlikely(TX_BUFFS_AVAIL(bp) < 1)) { @@ -1027,7 +1028,7 @@ static int b44_start_xmit(struct sk_buff *skb, struct net_device *dev) dev->trans_start = jiffies; out_unlock: - spin_unlock_irq(&bp->lock); + spin_unlock_irqrestore(&bp->lock, flags); return rc; -- cgit v1.1