4.20-stable review patch. If anyone has any objections, please let me know.
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From: Dmitry Safonov dima@arista.com
commit cf62a1a13749db0d32b5cdd800ea91a4087319de upstream.
As notted by Jiri, tty_ldisc_reinit() shouldn't rely on tty counter. Simplify math by increasing the counter after reinit success.
Cc: Jiri Slaby jslaby@suse.com Link: lkml.kernel.org/r/20180829022353.23568-2-dima@arista.com Suggested-by: Jiri Slaby jslaby@suse.com Reviewed-by: Jiri Slaby jslaby@suse.cz Tested-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Dmitry Safonov dima@arista.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/tty/tty_io.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-)
--- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -1272,16 +1272,13 @@ static int tty_reopen(struct tty_struct if (retval) return retval;
- tty->count++; - if (tty->ldisc) - goto out_unlock; + if (!tty->ldisc) + retval = tty_ldisc_reinit(tty, tty->termios.c_line); + tty_ldisc_unlock(tty);
- retval = tty_ldisc_reinit(tty, tty->termios.c_line); - if (retval) - tty->count--; + if (retval == 0) + tty->count++;
-out_unlock: - tty_ldisc_unlock(tty); return retval; }