[Xenial,2/7] tty: Reset c_line from driver's init_termios

Message ID 1502146366-26393-3-git-send-email-kamal@canonical.com
State New
Headers show

Commit Message

Kamal Mostafa Aug. 7, 2017, 10:52 p.m.
From: Peter Hurley <peter@hurleysoftware.com>

BugLink: http://bugs.launchpad.net/bugs/1709126

After the ldisc is released, but before the tty is destroyed, the termios
is saved (in tty_free_termios()); this termios is restored if a new
tty is created on next open(). However, the line discipline is always
reset, which is not obvious in the current method. Instead, reset
as part of the restore.

Restore the original line discipline, which may not have been N_TTY.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit ece53405a1f8ddf60b78e1365addcad521b2c93f)
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
 drivers/tty/tty_io.c    | 5 +++--
 drivers/tty/tty_ldisc.c | 3 ---
 2 files changed, 3 insertions(+), 5 deletions(-)

Patch

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index 1bb629a..02f78c0 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -1387,9 +1387,10 @@  int tty_init_termios(struct tty_struct *tty)
 	else {
 		/* Check for lazy saved data */
 		tp = tty->driver->termios[idx];
-		if (tp != NULL)
+		if (tp != NULL) {
 			tty->termios = *tp;
-		else
+			tty->termios.c_line  = tty->driver->init_termios.c_line;
+		} else
 			tty->termios = tty->driver->init_termios;
 	}
 	/* Compatibility until drivers always set this */
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 6f59f14..e24983d 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -745,9 +745,6 @@  static void tty_ldisc_kill(struct tty_struct *tty)
 	tty_ldisc_put(tty->ldisc);
 	/* Force an oops if we mess this up */
 	tty->ldisc = NULL;
-
-	/* Ensure the next open requests the N_TTY ldisc */
-	tty_set_termios_ldisc(tty, N_TTY);
 }
 
 /**