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/ucc_geth.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/net/ucc_geth.c') diff --git a/drivers/net/ucc_geth.c b/drivers/net/ucc_geth.c index 3b957e6412e..8a7b8c7bd78 100644 --- a/drivers/net/ucc_geth.c +++ b/drivers/net/ucc_geth.c @@ -3111,10 +3111,11 @@ static int ucc_geth_start_xmit(struct sk_buff *skb, struct net_device *dev) u8 __iomem *bd; /* BD pointer */ u32 bd_status; u8 txQ = 0; + unsigned long flags; ugeth_vdbg("%s: IN", __func__); - spin_lock_irq(&ugeth->lock); + spin_lock_irqsave(&ugeth->lock, flags); dev->stats.tx_bytes += skb->len; @@ -3171,7 +3172,7 @@ static int ucc_geth_start_xmit(struct sk_buff *skb, struct net_device *dev) uccf = ugeth->uccf; out_be16(uccf->p_utodr, UCC_FAST_TOD); #endif - spin_unlock_irq(&ugeth->lock); + spin_unlock_irqrestore(&ugeth->lock, flags); return 0; } -- cgit v1.2.3