Patch "ip_tunnel: fix preempt warning in ip tunnel creation/updating" has been added to the 4.4-stable tree

Patch "ip_tunnel: fix preempt warning in ip tunnel creation/updating" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ip_tunnel: fix preempt warning in ip tunnel creation/updating

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ip_tunnel-fix-preempt-warning-in-ip-tunnel-creation-updating.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From f27337e16f2d0e52a8d05ea599ed13cd266ac291 Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@redhat.com>
Date: Thu, 28 Apr 2016 11:04:51 +0200
Subject: ip_tunnel: fix preempt warning in ip tunnel creation/updating

From: Paolo Abeni <pabeni@redhat.com>

commit f27337e16f2d0e52a8d05ea599ed13cd266ac291 upstream.

After the commit e09acddf873b ("ip_tunnel: replace dst_cache with generic
implementation"), a preemption debug warning is triggered on ip4
tunnels updating; the dst cache helper needs to be invoked in unpreemptible
context.

We don't need to load the cache on tunnel update, so this commit fixes
the warning replacing the load with a dst cache reset, which is
preempt safe.

Fixes: e09acddf873b ("ip_tunnel: replace dst_cache with generic implementation")
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/ipv4/ip_tunnel.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -327,12 +327,12 @@ static int ip_tunnel_bind_dev(struct net
 
 		if (!IS_ERR(rt)) {
 			tdev = rt->dst.dev;
-			dst_cache_set_ip4(&tunnel->dst_cache, &rt->dst,
-					  fl4.saddr);
 			ip_rt_put(rt);
 		}
 		if (dev->type != ARPHRD_ETHER)
 			dev->flags |= IFF_POINTOPOINT;
+
+		dst_cache_reset(&tunnel->dst_cache);
 	}
 
 	if (!tdev && tunnel->parms.link)


Patches currently in stable-queue which might be from pabeni@redhat.com are

queue-4.4/ip_tunnel-fix-preempt-warning-in-ip-tunnel-creation-updating.patch
queue-4.4/ip_tunnel-replace-dst_cache-with-generic-implementation.patch
queue-4.4/netfilter-drop-outermost-socket-lock-in-getsockopt.patch