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| author | Wei Yongjun <yjwei@cn.fujitsu.com> | 2010-04-28 08:47:18 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-28 12:16:31 -0700 |
| commit | 561b1733a465cf9677356b40c27653dd45f1ac56 (patch) | |
| tree | 86d6720a6497a0b3faa9685596d4f85d3858b6fe | |
| parent | 8d238b25b1ec22a73b1c2206f111df2faaff8285 (diff) | |
| download | linux-561b1733a465cf9677356b40c27653dd45f1ac56.tar.bz2 | |
sctp: avoid irq lock inversion while call sk->sk_data_ready()
sk->sk_data_ready() of sctp socket can be called from both BH and non-BH
contexts, but the default sk->sk_data_ready(), sock_def_readable(), can
not be used in this case. Therefore, we have to make a new function
sctp_data_ready() to grab sk->sk_data_ready() with BH disabling.
=========================================================
[ INFO: possible irq lock inversion dependency detected ]
2.6.33-rc6 #129
---------------------------------------------------------
sctp_darn/1517 just changed the state of lock:
(clock-AF_INET){++.?..}, at: [<c06aab60>] sock_def_readable+0x20/0x80
but this lock took another, SOFTIRQ-unsafe lock in the past:
(slock-AF_INET){+.-...}
and interrupts could create inverse lock ordering between them.
other info that might help us debug this:
1 lock held by sctp_darn/1517:
#0: (sk_lock-AF_INET){+.+.+.}, at: [<cdfe363d>] sctp_sendmsg+0x23d/0xc00 [sctp]
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/sctp/sctp.h | 1 | ||||
| -rw-r--r-- | net/sctp/endpointola.c | 1 | ||||
| -rw-r--r-- | net/sctp/socket.c | 10 |
3 files changed, 12 insertions, 0 deletions
diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h index 78740ec57d5d..fa6cde578a1d 100644 --- a/include/net/sctp/sctp.h +++ b/include/net/sctp/sctp.h @@ -128,6 +128,7 @@ extern int sctp_register_pf(struct sctp_pf *, sa_family_t); int sctp_backlog_rcv(struct sock *sk, struct sk_buff *skb); int sctp_inet_listen(struct socket *sock, int backlog); void sctp_write_space(struct sock *sk); +void sctp_data_ready(struct sock *sk, int len); unsigned int sctp_poll(struct file *file, struct socket *sock, poll_table *wait); void sctp_sock_rfree(struct sk_buff *skb); diff --git a/net/sctp/endpointola.c b/net/sctp/endpointola.c index 905fda582b92..7ec09ba03a1c 100644 --- a/net/sctp/endpointola.c +++ b/net/sctp/endpointola.c @@ -144,6 +144,7 @@ static struct sctp_endpoint *sctp_endpoint_init(struct sctp_endpoint *ep, /* Use SCTP specific send buffer space queues. */ ep->sndbuf_policy = sctp_sndbuf_policy; + sk->sk_data_ready = sctp_data_ready; sk->sk_write_space = sctp_write_space; sock_set_flag(sk, SOCK_USE_WRITE_QUEUE); diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 007e8baba089..efa2bc3f0028 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -6189,6 +6189,16 @@ do_nonblock: goto out; } +void sctp_data_ready(struct sock *sk, int len) +{ + read_lock_bh(&sk->sk_callback_lock); + if (sk_has_sleeper(sk)) + wake_up_interruptible_sync_poll(sk->sk_sleep, POLLIN | + POLLRDNORM | POLLRDBAND); + sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); + read_unlock_bh(&sk->sk_callback_lock); +} + /* If socket sndbuf has changed, wake up all per association waiters. */ void sctp_write_space(struct sock *sk) { |