sctp: avoid irq lock inversion while call sk->sk_data_ready() (561b1733) · Commits · 戴 / test

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>

include/net/sctp/sctp.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -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);

net/sctp/endpointola.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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);

net/sctp/socket.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -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)
		{

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