4.9-stable review patch. If anyone has any objections, please let me know.
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From: Dmitry Safonov dima@arista.com
commit fe32416790093b31364c08395727de17ec96ace1 upstream.
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 892d1fa7eaae ("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
--- drivers/tty/tty_io.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)
--- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1475,6 +1475,7 @@ static void tty_driver_remove_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) @@ -1488,10 +1489,14 @@ static int tty_reopen(struct tty_struct
tty->count++;
- if (!tty->ldisc) - return tty_ldisc_reinit(tty, tty->termios.c_line); + if (tty->ldisc) + return 0;
- return 0; + retval = tty_ldisc_reinit(tty, tty->termios.c_line); + if (retval) + tty->count--; + + return retval; }
/**