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/tulip/tulip_core.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/net/tulip') diff --git a/drivers/net/tulip/tulip_core.c b/drivers/net/tulip/tulip_core.c index 99a63649f4fc..4cf9a6588751 100644 --- a/drivers/net/tulip/tulip_core.c +++ b/drivers/net/tulip/tulip_core.c @@ -652,8 +652,9 @@ tulip_start_xmit(struct sk_buff *skb, struct net_device *dev) int entry; u32 flag; dma_addr_t mapping; + unsigned long flags; - spin_lock_irq(&tp->lock); + spin_lock_irqsave(&tp->lock, flags); /* Calculate the next Tx descriptor entry. */ entry = tp->cur_tx % TX_RING_SIZE; @@ -688,7 +689,7 @@ tulip_start_xmit(struct sk_buff *skb, struct net_device *dev) /* Trigger an immediate transmit demand. */ iowrite32(0, tp->base_addr + CSR1); - spin_unlock_irq(&tp->lock); + spin_unlock_irqrestore(&tp->lock, flags); dev->trans_start = jiffies; -- cgit v1.2.1