From: Eric Dumazet edumazet@google.com

This fixes minor data-races in ip6_mc_input() and batadv_mcast_mla_rtr_flags_softif_get_ipv6()

Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net [sven@narfation.org: Add ugly hack to get it building with old kernels] Signed-off-by: Sven Eckelmann sven@narfation.org --- net-next commit 145c7a793838 ("ipv6: make mc_forwarding atomic")

I didn't find a good way to handle this. So either we introduce the auto-patch-before build stuff again or we allow minimal changes like this which are not in sync with upstream.

I will try to have a look at ways how we can (with our build_tests):

* filter out everything with UGLY_HACK + everything between UGLY_HACK_OLD + UGLY_HACK_STOP before comparing it with upstream * have some automatic warning in case someone adds code to linux-merge.git with UGLY_HACK in it

net/batman-adv/multicast.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/net/batman-adv/multicast.c b/net/batman-adv/multicast.c index 1860de73..720c12c0 100644 --- a/net/batman-adv/multicast.c +++ b/net/batman-adv/multicast.c @@ -135,7 +135,11 @@ static u8 batadv_mcast_mla_rtr_flags_softif_get_ipv6(struct net_device *dev) { struct inet6_dev *in6_dev = __in6_dev_get(dev);

+#if LINUX_VERSION_IS_GEQ(5, 18, 0) // UGLY_HACK_NEW + if (in6_dev && atomic_read(&in6_dev->cnf.mc_forwarding)) +#else // UGLY_HACK_OLD if (in6_dev && in6_dev->cnf.mc_forwarding) +#endif // UGLY_HACK_STOP return BATADV_NO_FLAGS; else return BATADV_MCAST_WANT_NO_RTR6;