diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-05-03 23:18:14 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-05-03 23:18:14 -0700 |
| commit | 93bb64eac10aad3dae6178d7da94765f207d121f (patch) | |
| tree | 5f0990ed1a0a9fa9483d828a16235085d5d84215 | |
| parent | f5460618405eec8c3300947a499011528a115acd (diff) | |
net: skb_free_datagram_locked() fix
Commit 4b0b72f7dd617b ( net: speedup udp receive path )
introduced a bug in skb_free_datagram_locked().
We should not skb_orphan() skb if we dont have the guarantee we are the
last skb user, this might happen with MSG_PEEK concurrent users.
To keep socket locked for the smallest period of time, we split
consume_skb() logic, inlined in skb_free_datagram_locked()
Reported-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/core/datagram.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index 95b851f3d71..e0097531417 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -229,13 +229,18 @@ EXPORT_SYMBOL(skb_free_datagram); void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) { + if (likely(atomic_read(&skb->users) == 1)) + smp_rmb(); + else if (likely(!atomic_dec_and_test(&skb->users))) + return; + lock_sock_bh(sk); skb_orphan(skb); sk_mem_reclaim_partial(sk); unlock_sock_bh(sk); - /* skb is now orphaned, might be freed outside of locked section */ - consume_skb(skb); + /* skb is now orphaned, can be freed outside of locked section */ + __kfree_skb(skb); } EXPORT_SYMBOL(skb_free_datagram_locked); |