From ae0e8e82205c903978a79ebf5e31c670b61fa5b4 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Mon, 27 Apr 2009 03:04:58 -0700 Subject: veth: prevent oops caused by netdev destructor From: Stephen Hemminger The veth driver will oops if sysfs hooks are open while module is removed. The net device destructor can not point to code in a module; basically there are only two possible safe values: NULL - no destructor, or free_netdev - free on last use Signed-off-by: David S. Miller --- drivers/net/veth.c | 41 ++++++++++++++++------------------------- 1 file changed, 16 insertions(+), 25 deletions(-) (limited to 'drivers/net/veth.c') diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 015db1cece72..8e56fcf0a0e3 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -210,14 +210,11 @@ rx_drop: static struct net_device_stats *veth_get_stats(struct net_device *dev) { - struct veth_priv *priv; - struct net_device_stats *dev_stats; - int cpu; + struct veth_priv *priv = netdev_priv(dev); + struct net_device_stats *dev_stats = &dev->stats; + unsigned int cpu; struct veth_net_stats *stats; - priv = netdev_priv(dev); - dev_stats = &dev->stats; - dev_stats->rx_packets = 0; dev_stats->tx_packets = 0; dev_stats->rx_bytes = 0; @@ -225,16 +222,17 @@ static struct net_device_stats *veth_get_stats(struct net_device *dev) dev_stats->tx_dropped = 0; dev_stats->rx_dropped = 0; - for_each_online_cpu(cpu) { - stats = per_cpu_ptr(priv->stats, cpu); + if (priv->stats) + for_each_online_cpu(cpu) { + stats = per_cpu_ptr(priv->stats, cpu); - dev_stats->rx_packets += stats->rx_packets; - dev_stats->tx_packets += stats->tx_packets; - dev_stats->rx_bytes += stats->rx_bytes; - dev_stats->tx_bytes += stats->tx_bytes; - dev_stats->tx_dropped += stats->tx_dropped; - dev_stats->rx_dropped += stats->rx_dropped; - } + dev_stats->rx_packets += stats->rx_packets; + dev_stats->tx_packets += stats->tx_packets; + dev_stats->rx_bytes += stats->rx_bytes; + dev_stats->tx_bytes += stats->tx_bytes; + dev_stats->tx_dropped += stats->tx_dropped; + dev_stats->rx_dropped += stats->rx_dropped; + } return dev_stats; } @@ -261,6 +259,8 @@ static int veth_close(struct net_device *dev) netif_carrier_off(dev); netif_carrier_off(priv->peer); + free_percpu(priv->stats); + priv->stats = NULL; return 0; } @@ -291,15 +291,6 @@ static int veth_dev_init(struct net_device *dev) return 0; } -static void veth_dev_free(struct net_device *dev) -{ - struct veth_priv *priv; - - priv = netdev_priv(dev); - free_percpu(priv->stats); - free_netdev(dev); -} - static const struct net_device_ops veth_netdev_ops = { .ndo_init = veth_dev_init, .ndo_open = veth_open, @@ -317,7 +308,7 @@ static void veth_setup(struct net_device *dev) dev->netdev_ops = &veth_netdev_ops; dev->ethtool_ops = &veth_ethtool_ops; dev->features |= NETIF_F_LLTX; - dev->destructor = veth_dev_free; + dev->destructor = free_netdev; } /* -- cgit v1.2.3-59-g8ed1b