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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2012-03-14 09:21:44 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-03-16 02:01:41 -0700 |
| commit | b8fbaef586176f6abe0eb7887ddae66e99898b79 (patch) | |
| tree | de0789276c35e3cb5d55dc858ce6b76a30918efc | |
| parent | bb6d5e76fb4fba9aa36726db41404512f3286c0f (diff) | |
| download | linux-b8fbaef586176f6abe0eb7887ddae66e99898b79.tar.bz2 | |
wimax/i2400m: fix erroneous NETDEV_TX_BUSY use
A driver start_xmit() method cannot free skb and return NETDEV_TX_BUSY,
since caller is going to reuse freed skb.
In fact netif_tx_stop_queue() / netif_stop_queue() is needed before
returning NETDEV_TX_BUSY or you can trigger a ksoftirqd fatal loop.
In case of memory allocation error, only safe way is to drop the packet
and return NETDEV_TX_OK
Also increments tx_dropped counter
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/wimax/i2400m/netdev.c | 30 |
1 files changed, 10 insertions, 20 deletions
diff --git a/drivers/net/wimax/i2400m/netdev.c b/drivers/net/wimax/i2400m/netdev.c index 64a110604ad3..63e4b709efa9 100644 --- a/drivers/net/wimax/i2400m/netdev.c +++ b/drivers/net/wimax/i2400m/netdev.c @@ -367,38 +367,28 @@ netdev_tx_t i2400m_hard_start_xmit(struct sk_buff *skb, { struct i2400m *i2400m = net_dev_to_i2400m(net_dev); struct device *dev = i2400m_dev(i2400m); - int result; + int result = -1; d_fnstart(3, dev, "(skb %p net_dev %p)\n", skb, net_dev); - if (skb_header_cloned(skb)) { - /* - * Make tcpdump/wireshark happy -- if they are - * running, the skb is cloned and we will overwrite - * the mac fields in i2400m_tx_prep_header. Expand - * seems to fix this... - */ - result = pskb_expand_head(skb, 0, 0, GFP_ATOMIC); - if (result) { - result = NETDEV_TX_BUSY; - goto error_expand; - } - } + + if (skb_header_cloned(skb) && + pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) + goto drop; if (i2400m->state == I2400M_SS_IDLE) result = i2400m_net_wake_tx(i2400m, net_dev, skb); else result = i2400m_net_tx(i2400m, net_dev, skb); - if (result < 0) + if (result < 0) { +drop: net_dev->stats.tx_dropped++; - else { + } else { net_dev->stats.tx_packets++; net_dev->stats.tx_bytes += skb->len; } - result = NETDEV_TX_OK; -error_expand: - kfree_skb(skb); + dev_kfree_skb(skb); d_fnend(3, dev, "(skb %p net_dev %p) = %d\n", skb, net_dev, result); - return result; + return NETDEV_TX_OK; } |