> -----Original Message----- > From: Parthasarathy Bhuvaragan > Sent: Thursday, April 27, 2017 07:54 AM > To: [email protected]; Jon Maloy > <[email protected]>; Ying Xue <[email protected]> > Subject: [PATCH net v1 4/6] tipc: lock wakeup & inputq at tipc_link_reset() > > Until now, in tipc_link_reset() we call copy the wakeup queue to input queue > using skb_queue_splice_init(link->wakeupq, link->inputq). > This is performed without holding any locks. This list might be simultaneously > be accessed by other cpu threads in tipc_sk_rcv() and that leads to random > missing packets. > > Signed-off-by: Parthasarathy Bhuvaragan > <[email protected]> > --- > net/tipc/link.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/net/tipc/link.c b/net/tipc/link.c index > ddd2dd6f77aa..722b82a884dc 100644 > --- a/net/tipc/link.c > +++ b/net/tipc/link.c > @@ -829,9 +829,14 @@ void tipc_link_reset(struct tipc_link *l) > l->peer_session = ANY_SESSION; > l->session++; > l->mtu = l->advertised_mtu; > + spin_lock_bh(&l->wakeupq.lock); > + spin_lock_bh(&l->inputq->lock); > + skb_queue_splice_init(&l->wakeupq, l->inputq); > + spin_unlock_bh(&l->inputq->lock); > + spin_unlock_bh(&l->wakeupq.lock); > +
I don't think you need to lock wakeupq here, since it is never touched outside the link lock scope. Actually, I don't see why this queue has a lock at all, it must be a missed remnant from the previous implementation. ///jon > __skb_queue_purge(&l->transmq); > __skb_queue_purge(&l->deferdq); > - skb_queue_splice_init(&l->wakeupq, l->inputq); > __skb_queue_purge(&l->backlogq); > l->backlog[TIPC_LOW_IMPORTANCE].len = 0; > l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0; > -- > 2.1.4 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ tipc-discussion mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/tipc-discussion
