From: Tung Nguyen <tung.q.ngu...@dektech.com.au> Date: Mon, 25 Feb 2019 10:57:20 +0700
> When sending multicast messages via blocking socket, > if sending link is congested (tsk->cong_link_cnt is set to 1), > the sending thread will be put into sleeping state. However, > tipc_sk_filter_rcv() is called under socket spin lock but > tipc_wait_for_cond() is not. So, there is no guarantee that > the setting of tsk->cong_link_cnt to 0 in tipc_sk_proto_rcv() in > CPU-1 will be perceived by CPU-0. If that is the case, the sending > thread in CPU-0 after being waken up, will continue to see > tsk->cong_link_cnt as 1 and put the sending thread into sleeping > state again. The sending thread will sleep forever. ... > This commit fixes it by adding memory barrier to tipc_sk_proto_rcv() > and tipc_wait_for_cond(). > > Acked-by: Jon Maloy <jon.ma...@ericsson.com> > Signed-off-by: Tung Nguyen <tung.q.ngu...@dektech.com.au> Applied and queued up for -stable.
