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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 "A functions set" in the NETPOLL API
callbacks causes the interrupts to get enabled and can lead to kernel
instability.

The solution is to use "B functions set" to prevent the irqs from
getting enabled while in netpoll_send_skb().

A functions set:
local_irq_disable()/local_irq_enable()
spin_lock_irq()/spin_unlock_irq()
spin_trylock_irq()/spin_unlock_irq()

B functions set:
local_irq_save()/local_irq_restore()
spin_lock_irqsave()/spin_unlock_irqrestore()
spin_trylock_irqsave()/spin_unlock_irqrestore()

Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Dongdong Deng 2009-08-23 19:49:07 -07:00 committed by David S. Miller
parent 79b1bee888
commit 4871953c0e
4 changed files with 13 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
drivers/net/fec_mpc52xx.c
View File

@ -309,6 +309,7 @@ static int mpc52xx_fec_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
struct mpc52xx_fec_priv *priv = netdev_priv(dev);
struct bcom_fec_bd *bd;
unsigned long flags;
if (bcom_queue_full(priv->tx_dmatsk)) {
if (net_ratelimit())
@ -316,7 +317,7 @@ static int mpc52xx_fec_start_xmit(struct sk_buff *skb, struct net_device *dev)
return NETDEV_TX_BUSY;
}
spin_lock_irq(&priv->lock);
spin_lock_irqsave(&priv->lock, flags);
dev->trans_start = jiffies;
bd = (struct bcom_fec_bd *)
@ -332,7 +333,7 @@ static int mpc52xx_fec_start_xmit(struct sk_buff *skb, struct net_device *dev)
netif_stop_queue(dev);
}
spin_unlock_irq(&priv->lock);
spin_unlock_irqrestore(&priv->lock, flags);
return NETDEV_TX_OK;
}

5
drivers/net/ixp2000/ixpdev.c
View File

@ -41,6 +41,7 @@ static int ixpdev_xmit(struct sk_buff *skb, struct net_device *dev)
struct ixpdev_priv *ip = netdev_priv(dev);
struct ixpdev_tx_desc *desc;
int entry;
unsigned long flags;
if (unlikely(skb->len > PAGE_SIZE)) {
/* @@@ Count drops. */
@ -63,11 +64,11 @@ static int ixpdev_xmit(struct sk_buff *skb, struct net_device *dev)
dev->trans_start = jiffies;
local_irq_disable();
local_irq_save(flags);
ip->tx_queue_entries++;
if (ip->tx_queue_entries == TX_BUF_COUNT_PER_CHAN)
netif_stop_queue(dev);
local_irq_enable();
local_irq_restore(flags);
return 0;
}

7
drivers/net/macb.c
View File

@ -620,6 +620,7 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
dma_addr_t mapping;
unsigned int len, entry;
u32 ctrl;
unsigned long flags;
#ifdef DEBUG
int i;
@ -635,12 +636,12 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
#endif
len = skb->len;
spin_lock_irq(&bp->lock);
spin_lock_irqsave(&bp->lock, flags);
/* This is a hard error, log it. */
if (TX_BUFFS_AVAIL(bp) < 1) {
netif_stop_queue(dev);
spin_unlock_irq(&bp->lock);
spin_unlock_irqrestore(&bp->lock, flags);
dev_err(&bp->pdev->dev,
"BUG! Tx Ring full when queue awake!\n");
dev_dbg(&bp->pdev->dev, "tx_head = %u, tx_tail = %u\n",
@ -674,7 +675,7 @@ static int macb_start_xmit(struct sk_buff *skb, struct net_device *dev)
if (TX_BUFFS_AVAIL(bp) < 1)
netif_stop_queue(dev);
spin_unlock_irq(&bp->lock);
spin_unlock_irqrestore(&bp->lock, flags);
dev->trans_start = jiffies;

5
drivers/net/mlx4/en_tx.c
View File

@ -437,6 +437,7 @@ static inline void mlx4_en_xmit_poll(struct mlx4_en_priv *priv, int tx_ind)
{
struct mlx4_en_cq *cq = &priv->tx_cq[tx_ind];
struct mlx4_en_tx_ring *ring = &priv->tx_ring[tx_ind];
unsigned long flags;
/* If we don't have a pending timer, set one up to catch our recent
post in case the interface becomes idle */
@ -445,9 +446,9 @@ static inline void mlx4_en_xmit_poll(struct mlx4_en_priv *priv, int tx_ind)
/* Poll the CQ every mlx4_en_TX_MODER_POLL packets */
if ((++ring->poll_cnt & (MLX4_EN_TX_POLL_MODER - 1)) == 0)
if (spin_trylock_irq(&ring->comp_lock)) {
if (spin_trylock_irqsave(&ring->comp_lock, flags)) {
mlx4_en_process_tx_cq(priv->dev, cq);
spin_unlock_irq(&ring->comp_lock);
spin_unlock_irqrestore(&ring->comp_lock, flags);
}
}