diff options
Diffstat (limited to 'drivers/char/tty_ldisc.c')
| -rw-r--r-- | drivers/char/tty_ldisc.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/char/tty_ldisc.c b/drivers/char/tty_ldisc.c index feb55075819b..d914e77f7f01 100644 --- a/drivers/char/tty_ldisc.c +++ b/drivers/char/tty_ldisc.c @@ -34,6 +34,8 @@ #include <linux/vt_kern.h> #include <linux/selection.h> +#include <linux/smp_lock.h> /* For the moment */ + #include <linux/kmod.h> #include <linux/nsproxy.h> @@ -545,6 +547,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) if (IS_ERR(new_ldisc)) return PTR_ERR(new_ldisc); + lock_kernel(); /* * We need to look at the tty locking here for pty/tty pairs * when both sides try to change in parallel. @@ -558,6 +561,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) */ if (tty->ldisc->ops->num == ldisc) { + unlock_kernel(); tty_ldisc_put(new_ldisc); return 0; } @@ -569,6 +573,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) tty_wait_until_sent(tty, 0); + unlock_kernel(); mutex_lock(&tty->ldisc_mutex); /* @@ -582,6 +587,9 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) test_bit(TTY_LDISC_CHANGING, &tty->flags) == 0); mutex_lock(&tty->ldisc_mutex); } + + lock_kernel(); + set_bit(TTY_LDISC_CHANGING, &tty->flags); /* @@ -592,6 +600,8 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) tty->receive_room = 0; o_ldisc = tty->ldisc; + + unlock_kernel(); /* * Make sure we don't change while someone holds a * reference to the line discipline. The TTY_LDISC bit @@ -617,12 +627,14 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) flush_scheduled_work(); mutex_lock(&tty->ldisc_mutex); + lock_kernel(); if (test_bit(TTY_HUPPED, &tty->flags)) { /* We were raced by the hangup method. It will have stomped the ldisc data and closed the ldisc down */ clear_bit(TTY_LDISC_CHANGING, &tty->flags); mutex_unlock(&tty->ldisc_mutex); tty_ldisc_put(new_ldisc); + unlock_kernel(); return -EIO; } @@ -664,6 +676,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) if (o_work) schedule_delayed_work(&o_tty->buf.work, 1); mutex_unlock(&tty->ldisc_mutex); + unlock_kernel(); return retval; } |