TTY: ldisc, fix open flag handling

commit 7f90cfc upstream. When a concrete ldisc open fails in tty_ldisc_open, we forget to clear TTY_LDISC_OPEN. This causes a false warning on the next ldisc open: WARNING: at drivers/char/tty_ldisc.c:445 tty_ldisc_open+0x26/0x38() Hardware name: System Product Name Modules linked in: ... Pid: 5251, comm: a.out Tainted: G W 2.6.32-5-686 coolya#1 Call Trace: [<c1030321>] ? warn_slowpath_common+0x5e/0x8a [<c1030357>] ? warn_slowpath_null+0xa/0xc [<c119311c>] ? tty_ldisc_open+0x26/0x38 [<c11936c5>] ? tty_set_ldisc+0x218/0x304 ... So clear the bit when failing... Introduced in c65c9bc (tty: rewrite the ldisc locking) back in 2.6.31-rc1. Signed-off-by: Jiri Slaby <[email protected]> Cc: Alan Cox <[email protected]> Reported-by: Sergey Lapin <[email protected]> Tested-by: Sergey Lapin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Andi Kleen <[email protected]>
TheEscapist13 · Dec 14, 2010 · 89f2685 · 89f2685
1 parent d509e24
commit 89f2685
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/drivers/char/tty_ldisc.c b/drivers/char/tty_ldisc.c
@@ -452,6 +452,8 @@ static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)
                 /* BKL here locks verus a hangup event */
 		lock_kernel();
 		ret = ld->ops->open(tty);
+		if (ret)
+			clear_bit(TTY_LDISC_OPEN, &tty->flags);
 		unlock_kernel();
 		return ret;
 	}