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>
diff --git a/drivers/net/fec_mpc52xx.c b/drivers/net/fec_mpc52xx.c
index cc78633..c40113f 100644
--- a/drivers/net/fec_mpc52xx.c
+++ b/drivers/net/fec_mpc52xx.c
@@ -309,6 +309,7 @@
{
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 @@
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 @@
netif_stop_queue(dev);
}
- spin_unlock_irq(&priv->lock);
+ spin_unlock_irqrestore(&priv->lock, flags);
return NETDEV_TX_OK;
}
diff --git a/drivers/net/ixp2000/ixpdev.c b/drivers/net/ixp2000/ixpdev.c
index 2a0174b..92fb823 100644
--- a/drivers/net/ixp2000/ixpdev.c
+++ b/drivers/net/ixp2000/ixpdev.c
@@ -41,6 +41,7 @@
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 @@
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;
}
diff --git a/drivers/net/macb.c b/drivers/net/macb.c
index 5b5c253..e3601cf3 100644
--- a/drivers/net/macb.c
+++ b/drivers/net/macb.c
@@ -620,6 +620,7 @@
dma_addr_t mapping;
unsigned int len, entry;
u32 ctrl;
+ unsigned long flags;
#ifdef DEBUG
int i;
@@ -635,12 +636,12 @@
#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 @@
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;
diff --git a/drivers/net/mlx4/en_tx.c b/drivers/net/mlx4/en_tx.c
index 5a88b3f5..6220840 100644
--- a/drivers/net/mlx4/en_tx.c
+++ b/drivers/net/mlx4/en_tx.c
@@ -437,6 +437,7 @@
{
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 @@
/* 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);
}
}