tty: drop outdated comments about release_tty() locking

The current version of the TTY code unlocks the tty_struct(s) before
release_tty() rather than after.  Moreover, tty_unlock_pair() no longer
exists.  Thus, remove the outdated comments regarding tty_unlock_pair().

Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200224073359.292795-1-ebiggers@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index a1453fe1086217d6a4e137a73fe954acee44676c..1fcf7ad83dfa0a2c1f20965acf0c1ab8496aa9d7 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1589,9 +1589,7 @@ void tty_kclose(struct tty_struct *tty)
        tty_debug_hangup(tty, "freeing structure\n");
        /*
         * The release_tty function takes care of the details of clearing
-        * the slots and preserving the termios structure. The tty_unlock_pair
-        * should be safe as we keep a kref while the tty is locked (so the
-        * unlock never unlocks a freed tty).
+        * the slots and preserving the termios structure.
         */
        mutex_lock(&tty_mutex);
        tty_port_set_kopened(tty->port, 0);
@@ -1621,9 +1619,7 @@ void tty_release_struct(struct tty_struct *tty, int idx)
        tty_debug_hangup(tty, "freeing structure\n");
        /*
         * The release_tty function takes care of the details of clearing
-        * the slots and preserving the termios structure. The tty_unlock_pair
-        * should be safe as we keep a kref while the tty is locked (so the
-        * unlock never unlocks a freed tty).
+        * the slots and preserving the termios structure.
         */
        mutex_lock(&tty_mutex);
        release_tty(tty, idx);