addrconf: reduce unnecessary atomic allocations

All the 3 callers of addrconf_add_mroute() assert RTNL
lock, they don't take any additional lock either, so
it is safe to convert it to GFP_KERNEL.

Same for sit_add_v4_addrs().

Cc: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Author: congwang

net/ipv6/addrconf.c

@@ -2398,7 +2398,7 @@ static void addrconf_add_mroute(struct net_device *dev)
 
 	ipv6_addr_set(&cfg.fc_dst, htonl(0xFF000000), 0, 0, 0);
 
-	ip6_route_add(&cfg, GFP_ATOMIC, NULL);
+	ip6_route_add(&cfg, GFP_KERNEL, NULL);
 }
 
 static struct inet6_dev *addrconf_add_dev(struct net_device *dev)
@@ -3062,7 +3062,7 @@ static void sit_add_v4_addrs(struct inet6_dev *idev)
 	if (addr.s6_addr32[3]) {
 		add_addr(idev, &addr, plen, scope);
 		addrconf_prefix_route(&addr, plen, 0, idev->dev, 0, pflags,
-				      GFP_ATOMIC);
+				      GFP_KERNEL);
 		return;
 	}
 
@@ -3087,7 +3087,7 @@ static void sit_add_v4_addrs(struct inet6_dev *idev)
 
 				add_addr(idev, &addr, plen, flag);
 				addrconf_prefix_route(&addr, plen, 0, idev->dev,
-						      0, pflags, GFP_ATOMIC);
+						      0, pflags, GFP_KERNEL);
 			}
 		}
 	}