Mon, Jul 29, 2019 at 07:52:16PM CEST, davem@davemloft.net wrote:

From: Jiri Pirko <jiri@resnulli.us>
Date: Sat, 27 Jul 2019 11:44:57 +0200

quoted

+	if ((netns_pid_attr && (netns_fd_attr || netns_id_attr)) ||
+	    (netns_fd_attr && (netns_pid_attr || netns_id_attr)) ||
+	    (netns_id_attr && (netns_pid_attr || netns_fd_attr))) {
+		NL_SET_ERR_MSG(info->extack, "multiple netns identifying attributes specified");
+		return ERR_PTR(-EINVAL);
+	}

How about:

if (!!a + !!b + !!c > 1) {
...

I just copied the logic from the existing code. But sure :)

quoted

+
+	if (netns_pid_attr) {
+		net = get_net_ns_by_pid(nla_get_u32(netns_pid_attr));
+	} else if (netns_fd_attr) {
+		net = get_net_ns_by_fd(nla_get_u32(netns_fd_attr));
+	} else if (netns_id_attr) {
+		net = get_net_ns_by_id(sock_net(skb->sk),
+				       nla_get_u32(netns_id_attr));
+		if (!net)
+			net = ERR_PTR(-EINVAL);
+	}
+	if (IS_ERR(net)) {

I think this is going to be one of those cases where a compiler won't be able
to prove that 'net' is guaranteed to be initialized at this spot.  Please
rearrange this code somehow so that is unlikely to happen.

It does not complain though. The function cannot be entered unless at
least one is. I'll check again.

Thanks.