net: introduce lockdep_is_held and update various places to use it

The socket is either locked if we hold the slock spin_lock for
lock_sock_fast and unlock_sock_fast or we own the lock (sk_lock.owned
!= 0). Check for this and at the same time improve that the current
thread/cpu is really holding the lock.

Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 5 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 456ff3d6a132..f4f2a0a3849d 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -157,7 +157,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 
         nexthop = daddr = usin->sin_addr.s_addr;
         inet_opt = rcu_dereference_protected(inet->inet_opt,
-                                             sock_owned_by_user(sk));
+                                             lockdep_sock_is_held(sk));
         if (inet_opt && inet_opt->opt.srr) {
                 if (!daddr)
                         return -EINVAL;
@@ -882,8 +882,7 @@ struct tcp_md5sig_key *tcp_md5_do_lookup(const struct sock *sk,
 
         /* caller either holds rcu_read_lock() or socket lock */
         md5sig = rcu_dereference_check(tp->md5sig_info,
-                                       sock_owned_by_user(sk) ||
-                                       lockdep_is_held((spinlock_t *)&sk->sk_lock.slock));
+                                       lockdep_sock_is_held(sk));
         if (!md5sig)
                 return NULL;
 #if IS_ENABLED(CONFIG_IPV6)
@@ -928,8 +927,7 @@ int tcp_md5_do_add(struct sock *sk, const union tcp_md5_addr *addr,
         }
 
         md5sig = rcu_dereference_protected(tp->md5sig_info,
-                                           sock_owned_by_user(sk) ||
-                                           lockdep_is_held(&sk->sk_lock.slock));
+                                           lockdep_sock_is_held(sk));
         if (!md5sig) {
                 md5sig = kmalloc(sizeof(*md5sig), gfp);
                 if (!md5sig)