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authorWei Yongjun <yjwei@cn.fujitsu.com>2010-04-28 12:47:18 +0400
committerDavid S. Miller <davem@davemloft.net>2010-04-28 23:16:31 +0400
commit561b1733a465cf9677356b40c27653dd45f1ac56 (patch)
tree86d6720a6497a0b3faa9685596d4f85d3858b6fe /net
parent8d238b25b1ec22a73b1c2206f111df2faaff8285 (diff)
downloadlinux-561b1733a465cf9677356b40c27653dd45f1ac56.tar.xz
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>
Diffstat (limited to 'net')
-rw-r--r--net/sctp/endpointola.c1
-rw-r--r--net/sctp/socket.c10
2 files changed, 11 insertions, 0 deletions
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)
{