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tty: Push the lock down further into the ldisc code 

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Cox 2009-11-30 13:18:35 +00:00 committed by Greg Kroah-Hartman
parent eeb89d918c
commit f18f9498e9
2 changed files with 9 additions and 5 deletions
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2
drivers/char/tty_io.c
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@ -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;

12
drivers/char/tty_ldisc.c
View File

@ -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);
/*