From: Wei Yongjun Date: Wed, 22 Apr 2020 02:11:35 +0000 (+0800) Subject: macvlan: silence RCU list debugging warning X-Git-Tag: v5.8-rc1~165^2~458 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=58e64a312c8468f3e8adead24b71ebb3039b381e;p=linux.git macvlan: silence RCU list debugging warning macvlan_hash_lookup() uses list_for_each_entry_rcu() for traversing should either under RCU in fast path or the protection of rtnl_mutex. In the case of holding RTNL, we should add the corresponding lockdep expression to silence the following false-positive warning: ============================= WARNING: suspicious RCU usage 5.7.0-rc1-next-20200416-00003-ga3b8d28bc #1 Not tainted ----------------------------- drivers/net/macvlan.c:126 RCU-list traversed in non-reader section!! Signed-off-by: Wei Yongjun Signed-off-by: David S. Miller --- diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c index e7289d67268f..654c1fa11826 100644 --- a/drivers/net/macvlan.c +++ b/drivers/net/macvlan.c @@ -123,7 +123,8 @@ static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port, struct macvlan_dev *vlan; u32 idx = macvlan_eth_hash(addr); - hlist_for_each_entry_rcu(vlan, &port->vlan_hash[idx], hlist) { + hlist_for_each_entry_rcu(vlan, &port->vlan_hash[idx], hlist, + lockdep_rtnl_is_held()) { if (ether_addr_equal_64bits(vlan->dev->dev_addr, addr)) return vlan; }