diff options
Diffstat (limited to 'drivers/tty/tty_ldisc.c')
| -rw-r--r-- | drivers/tty/tty_ldisc.c | 30 |
1 files changed, 23 insertions, 7 deletions
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c index 512c49f98e8..8e0924f5544 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -36,6 +36,7 @@ #include <linux/kmod.h> #include <linux/nsproxy.h> +#include <linux/ratelimit.h> /* * This guards the refcounted line discipline lists. The lock @@ -547,15 +548,16 @@ static void tty_ldisc_flush_works(struct tty_struct *tty) /** * tty_ldisc_wait_idle - wait for the ldisc to become idle * @tty: tty to wait for + * @timeout: for how long to wait at most * * Wait for the line discipline to become idle. The discipline must * have been halted for this to guarantee it remains idle. */ -static int tty_ldisc_wait_idle(struct tty_struct *tty) +static int tty_ldisc_wait_idle(struct tty_struct *tty, long timeout) { - int ret; + long ret; ret = wait_event_timeout(tty_ldisc_idle, - atomic_read(&tty->ldisc->users) == 1, 5 * HZ); + atomic_read(&tty->ldisc->users) == 1, timeout); if (ret < 0) return ret; return ret > 0 ? 0 : -EBUSY; @@ -665,7 +667,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc) tty_ldisc_flush_works(tty); - retval = tty_ldisc_wait_idle(tty); + retval = tty_ldisc_wait_idle(tty, 5 * HZ); tty_lock(); mutex_lock(&tty->ldisc_mutex); @@ -762,8 +764,6 @@ static int tty_ldisc_reinit(struct tty_struct *tty, int ldisc) if (IS_ERR(ld)) return -1; - WARN_ON_ONCE(tty_ldisc_wait_idle(tty)); - tty_ldisc_close(tty, tty->ldisc); tty_ldisc_put(tty->ldisc); tty->ldisc = NULL; @@ -838,7 +838,7 @@ void tty_ldisc_hangup(struct tty_struct *tty) tty_unlock(); cancel_work_sync(&tty->buf.work); mutex_unlock(&tty->ldisc_mutex); - +retry: tty_lock(); mutex_lock(&tty->ldisc_mutex); @@ -847,6 +847,22 @@ void tty_ldisc_hangup(struct tty_struct *tty) it means auditing a lot of other paths so this is a FIXME */ if (tty->ldisc) { /* Not yet closed */ + if (atomic_read(&tty->ldisc->users) != 1) { + char cur_n[TASK_COMM_LEN], tty_n[64]; + long timeout = 3 * HZ; + tty_unlock(); + + while (tty_ldisc_wait_idle(tty, timeout) == -EBUSY) { + timeout = MAX_SCHEDULE_TIMEOUT; + printk_ratelimited(KERN_WARNING + "%s: waiting (%s) for %s took too long, but we keep waiting...\n", + __func__, get_task_comm(cur_n, current), + tty_name(tty, tty_n)); + } + mutex_unlock(&tty->ldisc_mutex); + goto retry; + } + if (reset == 0) { if (!tty_ldisc_reinit(tty, tty->termios->c_line)) |