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| author | Sven Eckelmann <sven@narfation.org> | 2017-01-28 10:12:39 +0100 |
|---|---|---|
| committer | Simon Wunderlich <sw@simonwunderlich.de> | 2017-01-28 10:40:35 +0100 |
| commit | 7c946062b3ae2b7f002383e5e402113e98ad3c77 (patch) | |
| tree | 03db0aab75359f626c79d66553331a3aee6d3823 /net/batman-adv | |
| parent | c33705188c493b7de3b8dc2956d67de91b444727 (diff) | |
| download | lwn-7c946062b3ae2b7f002383e5e402113e98ad3c77.tar.gz lwn-7c946062b3ae2b7f002383e5e402113e98ad3c77.zip | |
batman-adv: Fix double call of dev_queue_xmit
The net_xmit_eval has side effects because it is not making sure that e
isn't evaluated twice.
#define net_xmit_eval(e) ((e) == NET_XMIT_CN ? 0 : (e))
The code requested by David Miller [1]
return net_xmit_eval(dev_queue_xmit(skb));
will get transformed into
return ((dev_queue_xmit(skb)) == NET_XMIT_CN ? 0 : (dev_queue_xmit(skb)))
dev_queue_xmit will therefore be tried again (with an already consumed skb)
whenever the return code is not NET_XMIT_CN.
[1] https://lkml.kernel.org/r/20170125.225624.965229145391320056.davem@davemloft.net
Fixes: c33705188c49 ("batman-adv: Treat NET_XMIT_CN as transmit successfully")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'net/batman-adv')
| -rw-r--r-- | net/batman-adv/send.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index d9b2889064a6..1489ec27daff 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -77,6 +77,7 @@ int batadv_send_skb_packet(struct sk_buff *skb, { struct batadv_priv *bat_priv; struct ethhdr *ethhdr; + int ret; bat_priv = netdev_priv(hard_iface->soft_iface); @@ -115,7 +116,8 @@ int batadv_send_skb_packet(struct sk_buff *skb, * congestion and traffic shaping, it drops and returns NET_XMIT_DROP * (which is > 0). This will not be treated as an error. */ - return net_xmit_eval(dev_queue_xmit(skb)); + ret = dev_queue_xmit(skb); + return net_xmit_eval(ret); send_skb_err: kfree_skb(skb); return NET_XMIT_DROP; |