[PATCH v2 net-next 09/15] socket: Respect hold_net in sk_alloc().

[Kuniyuki Iwashima <kuniyu@amazon.com>]

We will introduce a new API to create a kernel socket with netns
refcnt held.

sk->sk_net_refcnt was set to 0 when kern was 1 in sk_alloc().

Now we have the hold_net flag in sk_alloc().

Let's set it to sk->sk_net_refcnt and add an assertion to catch
only one illegal pattern.

No functional change is introduced for now because currently
hold_net == !kern.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/core/sock.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/core/sock.c b/net/core/sock.c
index 8546d97cc6ec..11aa6d8c0cdd 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2224,9 +2224,12 @@ struct sock *sk_alloc(struct net *net, int family, gfp_t priority,
 		 * why we need sk_prot_creator -acme
 		 */
 		sk->sk_prot = sk->sk_prot_creator = prot;
+
+		DEBUG_NET_WARN_ON_ONCE(!kern && !hold_net);
 		sk->sk_kern_sock = kern;
 		sock_lock_init(sk);
-		sk->sk_net_refcnt = kern ? 0 : 1;
+
+		sk->sk_net_refcnt = hold_net;
 		if (likely(sk->sk_net_refcnt)) {
 			get_net_track(net, &sk->ns_tracker, priority);
 			sock_inuse_add(net, 1);
-- 
2.39.5 (Apple Git-154)