From 22580f894ac190c46beebb5c3172e450a2318f79 Mon Sep 17 00:00:00 2001 From: Dongdong Deng Date: Thu, 13 Aug 2009 19:12:31 +0000 Subject: [PATCH] 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 +++-- drivers/net/tulip/tulip_core.c | 5 +++-- drivers/net/ucc_geth.c | 5 +++-- drivers/net/via-rhine.c | 5 +++-- 4 files changed, 12 insertions(+), 8 deletions(-) diff --git a/drivers/net/b44.c b/drivers/net/b44.c index 36d4d377ec2..bafca672ea7 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; diff --git a/drivers/net/tulip/tulip_core.c b/drivers/net/tulip/tulip_core.c index 99a63649f4f..4cf9a658875 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; 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; } diff --git a/drivers/net/via-rhine.c b/drivers/net/via-rhine.c index 88c30a58b4b..934f7671650 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", -- 2.20.1