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/via-rhine.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/net/via-rhine.c') diff --git a/drivers/net/via-rhine.c b/drivers/net/via-rhine.c index 88c30a58b4bd..934f7671650a 100644 --- a/drivers/net/via-rhine.c +++ b/drivers/net/via-rhine.c @@ -1218,6 +1218,7 @@ static int rhine_start_tx(struct sk_buff *skb, struct net_device *dev) struct rhine_private *rp = netdev_priv(dev); void __iomem *ioaddr = rp->base; unsigned entry; + unsigned long flags; /* Caution: the write order is important here, set the field with the "ownership" bits last. */ @@ -1261,7 +1262,7 @@ static int rhine_start_tx(struct sk_buff *skb, struct net_device *dev) cpu_to_le32(TXDESC | (skb->len >= ETH_ZLEN ? skb->len : ETH_ZLEN)); /* lock eth irq */ - spin_lock_irq(&rp->lock); + spin_lock_irqsave(&rp->lock, flags); wmb(); rp->tx_ring[entry].tx_status = cpu_to_le32(DescOwn); wmb(); @@ -1280,7 +1281,7 @@ static int rhine_start_tx(struct sk_buff *skb, struct net_device *dev) dev->trans_start = jiffies; - spin_unlock_irq(&rp->lock); + spin_unlock_irqrestore(&rp->lock, flags); if (debug > 4) { printk(KERN_DEBUG "%s: Transmit frame #%d queued in slot %d.\n", -- cgit v1.2.3-59-g8ed1b