From: Kuniyuki Iwashima <kuniyu@amazon.com>

Since DCCP has been removed, sk->sk_prot->twsk_prot->twsk_destructor
is always tcp_twsk_destructor().

Let's call tcp_twsk_destructor() directly in inet_twsk_free() and
remove ->twsk_destructor().

While at it, tcp_twsk_destructor() is un-exported.

Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
---
 include/net/timewait_sock.h   | 7 -------
 net/ipv4/inet_timewait_sock.c | 4 ++--
 net/ipv4/tcp_ipv4.c           | 1 -
 net/ipv4/tcp_minisocks.c      | 1 -
 net/ipv6/tcp_ipv6.c           | 1 -
 5 files changed, 2 insertions(+), 12 deletions(-)

diff --git a/include/net/timewait_sock.h b/include/net/timewait_sock.h
index 62b3e9f2aed4..0a85ac64a66d 100644
--- a/include/net/timewait_sock.h
+++ b/include/net/timewait_sock.h
@@ -15,13 +15,6 @@ struct timewait_sock_ops {
 	struct kmem_cache	*twsk_slab;
 	char		*twsk_slab_name;
 	unsigned int	twsk_obj_size;
-	void		(*twsk_destructor)(struct sock *sk);
 };
 
-static inline void twsk_destructor(struct sock *sk)
-{
-	if (sk->sk_prot->twsk_prot->twsk_destructor != NULL)
-		sk->sk_prot->twsk_prot->twsk_destructor(sk);
-}
-
 #endif /* _TIMEWAIT_SOCK_H */
diff --git a/net/ipv4/inet_timewait_sock.c b/net/ipv4/inet_timewait_sock.c
index 024463a3e696..3fd46122d313 100644
--- a/net/ipv4/inet_timewait_sock.c
+++ b/net/ipv4/inet_timewait_sock.c
@@ -15,7 +15,7 @@
 #include <net/inet_hashtables.h>
 #include <net/inet_timewait_sock.h>
 #include <net/ip.h>
-
+#include <net/tcp.h>
 
 /**
  *	inet_twsk_bind_unhash - unhash a timewait socket from bind hash
@@ -73,7 +73,7 @@ static void inet_twsk_kill(struct inet_timewait_sock *tw)
 
 void inet_twsk_free(struct inet_timewait_sock *tw)
 {
-	twsk_destructor((struct sock *)tw);
+	tcp_twsk_destructor((struct sock *)tw);
 	kfree(tw);
 }
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 84d3d556ed80..c7b9377e5a66 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -2459,7 +2459,6 @@ int tcp_v4_rcv(struct sk_buff *skb)
 
 static struct timewait_sock_ops tcp_timewait_sock_ops = {
 	.twsk_obj_size	= sizeof(struct tcp_timewait_sock),
-	.twsk_destructor= tcp_twsk_destructor,
 };
 
 void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb)
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index 2994c9222c9c..d1c9e4088646 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -401,7 +401,6 @@ void tcp_twsk_destructor(struct sock *sk)
 #endif
 	tcp_ao_destroy_sock(sk, true);
 }
-EXPORT_IPV6_MOD_GPL(tcp_twsk_destructor);
 
 void tcp_twsk_purge(struct list_head *net_exit_list)
 {
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 7577e7eb2c97..4bc0431bf928 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -2050,7 +2050,6 @@ void tcp_v6_early_demux(struct sk_buff *skb)
 
 static struct timewait_sock_ops tcp6_timewait_sock_ops = {
 	.twsk_obj_size	= sizeof(struct tcp6_timewait_sock),
-	.twsk_destructor = tcp_twsk_destructor,
 };
 
 INDIRECT_CALLABLE_SCOPE void tcp_v6_send_check(struct sock *sk, struct sk_buff *skb)
-- 
2.51.0.rc1.193.gad69d77794-goog