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Commit f18f9498 authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
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tty: Push the lock down further into the ldisc code 



Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent eeb89d91

drivers/char/tty_io.c

+0 −2
Original line number Diff line number Diff line
@@ -1347,9 +1347,7 @@ struct tty_struct *tty_init_dev(struct tty_driver *driver, int idx, 
	 * If we fail here just call release_tty to clean up.  No need

	 * to decrement the use counts, as release_tty doesn't care.

	 */

	lock_kernel();

	retval = tty_ldisc_setup(tty, tty->link);

	unlock_kernel();

	if (retval)

		goto release_mem_out;

	return tty;

drivers/char/tty_ldisc.c

+9 −3
Original line number Diff line number Diff line
@@ -445,8 +445,14 @@ static void tty_set_termios_ldisc(struct tty_struct *tty, int num) 
static int tty_ldisc_open(struct tty_struct *tty, struct tty_ldisc *ld)

{

	WARN_ON(test_and_set_bit(TTY_LDISC_OPEN, &tty->flags));

	if (ld->ops->open)

		return ld->ops->open(tty);

	if (ld->ops->open) {

		int ret;

                /* BKL here locks verus a hangup event */

		lock_kernel();

		ret = ld->ops->open(tty);

		unlock_kernel();

		return ret;

	}

	return 0;

}
@@ -566,6 +572,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) 
		return 0;

	}



	unlock_kernel();

	/*

	 *	Problem: What do we do if this blocks ?

	 *	We could deadlock here
@@ -573,7 +580,6 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) 


	tty_wait_until_sent(tty, 0);



	unlock_kernel();

	mutex_lock(&tty->ldisc_mutex);



	/*