Merge r196481 from head to stable/8:

  Rework global locks for interface list and index management, correcting
  several critical bugs, including race conditions and lock order issues:

  Replace the single rwlock, ifnet_lock, with two locks, an rwlock and an
  sxlock.  Either can be held to stablize the lists and indexes, but both
  are required to write.  This allows the list to be held stable in both
  network interrupt contexts and sleepable user threads across sleeping
  memory allocations or device driver interactions.  As before, writes to
  the interface list must occur from sleepable contexts.

  Reviewed by:  bz, julian

Approved by:	re (kib)

1 files changed, 2 insertions, 2 deletions

diff --git a/sys/netinet6/nd6.c b/sys/netinet6/nd6.c
index 48635c5..acaa87e 100644
--- a/sys/netinet6/nd6.c
+++ b/sys/netinet6/nd6.c
@@ -1662,7 +1662,7 @@ nd6_slowtimo(void *arg)
 
 	callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
 	    nd6_slowtimo, curvnet);
-	IFNET_RLOCK();
+	IFNET_RLOCK_NOSLEEP();
 	for (ifp = TAILQ_FIRST(&V_ifnet); ifp;
 	    ifp = TAILQ_NEXT(ifp, if_list)) {
 		nd6if = ND_IFINFO(ifp);
@@ -1678,7 +1678,7 @@ nd6_slowtimo(void *arg)
 			nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
 		}
 	}
-	IFNET_RUNLOCK();
+	IFNET_RUNLOCK_NOSLEEP();
 	CURVNET_RESTORE();
 }