Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index c36757e..12e2dda 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -1,9 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  * NET3:	Garbage Collector For AF_UNIX sockets
  *
  * Garbage Collector:
  *	Copyright (C) Barak A. Pearlmutter.
- *	Released under the GPL version 2 or later.
  *
  * Chopped about by Alan Cox 22/3/96 to make it fit the AF_UNIX socket problem.
  * If it doesn't work blame me, it worked when Barak sent it.
@@ -24,11 +24,6 @@
  *
  *  - don't just push entire root set; process in place
  *
- *	This program is free software; you can redistribute it and/or
- *	modify it under the terms of the GNU General Public License
- *	as published by the Free Software Foundation; either version
- *	2 of the License, or (at your option) any later version.
- *
  *  Fixes:
  *	Alan Cox	07 Sept	1997	Vmalloc internal stack as needed.
  *					Cope with changing max_files.
@@ -86,77 +81,13 @@
 #include <net/scm.h>
 #include <net/tcp_states.h>
 
+#include "scm.h"
+
 /* Internal data structures and random procedures: */
 
-static LIST_HEAD(gc_inflight_list);
 static LIST_HEAD(gc_candidates);
-static DEFINE_SPINLOCK(unix_gc_lock);
 static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait);
 
-unsigned int unix_tot_inflight;
-
-struct sock *unix_get_socket(struct file *filp)
-{
-	struct sock *u_sock = NULL;
-	struct inode *inode = file_inode(filp);
-
-	/* Socket ? */
-	if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) {
-		struct socket *sock = SOCKET_I(inode);
-		struct sock *s = sock->sk;
-
-		/* PF_UNIX ? */
-		if (s && sock->ops && sock->ops->family == PF_UNIX)
-			u_sock = s;
-	}
-	return u_sock;
-}
-
-/* Keep the number of times in flight count for the file
- * descriptor if it is for an AF_UNIX socket.
- */
-
-void unix_inflight(struct user_struct *user, struct file *fp)
-{
-	struct sock *s = unix_get_socket(fp);
-
-	spin_lock(&unix_gc_lock);
-
-	if (s) {
-		struct unix_sock *u = unix_sk(s);
-
-		if (atomic_long_inc_return(&u->inflight) == 1) {
-			BUG_ON(!list_empty(&u->link));
-			list_add_tail(&u->link, &gc_inflight_list);
-		} else {
-			BUG_ON(list_empty(&u->link));
-		}
-		unix_tot_inflight++;
-	}
-	user->unix_inflight++;
-	spin_unlock(&unix_gc_lock);
-}
-
-void unix_notinflight(struct user_struct *user, struct file *fp)
-{
-	struct sock *s = unix_get_socket(fp);
-
-	spin_lock(&unix_gc_lock);
-
-	if (s) {
-		struct unix_sock *u = unix_sk(s);
-
-		BUG_ON(!atomic_long_read(&u->inflight));
-		BUG_ON(list_empty(&u->link));
-
-		if (atomic_long_dec_and_test(&u->inflight))
-			list_del_init(&u->link);
-		unix_tot_inflight--;
-	}
-	user->unix_inflight--;
-	spin_unlock(&unix_gc_lock);
-}
-
 static void scan_inflight(struct sock *x, void (*func)(struct unix_sock *),
 			  struct sk_buff_head *hitlist)
 {