Commit fe324167 authored Sep 18, 2018 by Dmitry Safonov Committed by Greg Kroah-Hartman Sep 18, 2018

tty: Drop tty->count on tty_reopen() failure



In case of tty_ldisc_reinit() failure, tty->count should be decremented
back, otherwise we will never release_tty().
Tetsuo reported that it fixes noisy warnings on tty release like:
  pts pts4033: tty_release: tty->count(10529) != (#fd's(7) + #kopen's(0))

Fixes: commit 892d1fa7 ("tty: Destroy ldisc instance on hangup")

Cc: stable@vger.kernel.org # v4.6+
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Reviewed-by: Jiri Slaby <jslaby@suse.cz>
Tested-by: Jiri Slaby <jslaby@suse.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent be28c1e3

drivers/tty/tty_io.c

+8 −3

Original line number	Diff line number	Diff line
		@@ -1255,6 +1255,7 @@ static void tty_driver_remove_tty(struct tty_driver driver, struct tty_struct
		static int tty_reopen(struct tty_struct *tty)
		{
		struct tty_driver *driver = tty->driver;
		int retval;

		if (driver->type == TTY_DRIVER_TYPE_PTY &&
		driver->subtype == PTY_TYPE_MASTER)
		@@ -1268,10 +1269,14 @@ static int tty_reopen(struct tty_struct *tty)

		tty->count++;

		if (!tty->ldisc)
		return tty_ldisc_reinit(tty, tty->termios.c_line);

		if (tty->ldisc)
		return 0;

		retval = tty_ldisc_reinit(tty, tty->termios.c_line);
		if (retval)
		tty->count--;

		return retval;
		}

		/**

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