From b27401a30ee466c4476b035487be0580767ba1fb Mon Sep 17 00:00:00 2001
From: Kirill Tkhai <tkhai@ya.ru>
Date: Sat, 14 Jan 2023 12:35:02 +0300
Subject: unix: Improve locking scheme in unix_show_fdinfo()

After switching to TCP_ESTABLISHED or TCP_LISTEN sk_state, alive SOCK_STREAM
and SOCK_SEQPACKET sockets can't change it anymore (since commit 3ff8bff704f4
"unix: Fix race in SOCK_SEQPACKET's unix_dgram_sendmsg()").

Thus, we do not need to take lock here.

Signed-off-by: Kirill Tkhai <tkhai@ya.ru>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/unix/af_unix.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

(limited to 'net/unix/af_unix.c')

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index f0c2293f1d3b..009616fa0256 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -807,23 +807,23 @@ static int unix_count_nr_fds(struct sock *sk)
 static void unix_show_fdinfo(struct seq_file *m, struct socket *sock)
 {
 	struct sock *sk = sock->sk;
+	unsigned char s_state;
 	struct unix_sock *u;
-	int nr_fds;
+	int nr_fds = 0;
 
 	if (sk) {
+		s_state = READ_ONCE(sk->sk_state);
 		u = unix_sk(sk);
-		if (sock->type == SOCK_DGRAM) {
-			nr_fds = atomic_read(&u->scm_stat.nr_fds);
-			goto out_print;
-		}
 
-		unix_state_lock(sk);
-		if (sk->sk_state != TCP_LISTEN)
+		/* SOCK_STREAM and SOCK_SEQPACKET sockets never change their
+		 * sk_state after switching to TCP_ESTABLISHED or TCP_LISTEN.
+		 * SOCK_DGRAM is ordinary. So, no lock is needed.
+		 */
+		if (sock->type == SOCK_DGRAM || s_state == TCP_ESTABLISHED)
 			nr_fds = atomic_read(&u->scm_stat.nr_fds);
-		else
+		else if (s_state == TCP_LISTEN)
 			nr_fds = unix_count_nr_fds(sk);
-		unix_state_unlock(sk);
-out_print:
+
 		seq_printf(m, "scm_fds: %u\n", nr_fds);
 	}
 }
-- 
cgit 


From 509f15b9c551b750d8f634d404805c3860e9ea17 Mon Sep 17 00:00:00 2001
From: Jakub Kicinski <kuba@kernel.org>
Date: Wed, 25 Jan 2023 23:14:21 -0800
Subject: net: add missing includes of linux/splice.h

Number of files depend on linux/splice.h getting included
by linux/skbuff.h which soon will no longer be the case.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/unix/af_unix.c | 1 +
 1 file changed, 1 insertion(+)

(limited to 'net/unix/af_unix.c')

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 009616fa0256..0be25e712c28 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -112,6 +112,7 @@
 #include <linux/mount.h>
 #include <net/checksum.h>
 #include <linux/security.h>
+#include <linux/splice.h>
 #include <linux/freezer.h>
 #include <linux/file.h>
 #include <linux/btf_ids.h>
-- 
cgit