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| author | Sasha Levin <sasha.levin@oracle.com> | 2015-10-31 15:54:32 +0300 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2015-10-31 15:54:32 +0300 |
| commit | 80e5c4ddd2fcbf99edd31a7c1379b3907cfd4f38 (patch) | |
| tree | 458417709b52b633226534d82b35cc01a22ce9cb | |
| parent | 8341455f7f2b36212f8cdded7725e93b17f5a8fc (diff) | |
| download | linux-80e5c4ddd2fcbf99edd31a7c1379b3907cfd4f38.tar.xz | |
Revert "tty: fix stall caused by missing memory barrier in drivers/tty/n_tty.c"
This reverts commit af32cc7bde6304dac92e6a74fe4b2cc8120cb29a.
The commit was incorrectly backported and was causing hangs.
Reported-by: Corey Wright <undefined@pobox.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
| -rw-r--r-- | drivers/tty/n_tty.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index fea7d905e77c..e3ebb674a693 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -364,8 +364,8 @@ static void n_tty_packet_mode_flush(struct tty_struct *tty) spin_lock_irqsave(&tty->ctrl_lock, flags); if (tty->link->packet) { tty->ctrl_status |= TIOCPKT_FLUSHREAD; - spin_unlock_irqrestore(&tty->ctrl_lock, flags); - wake_up_interruptible(&tty->link->read_wait); + if (waitqueue_active(&tty->link->read_wait)) + wake_up_interruptible(&tty->link->read_wait); } spin_unlock_irqrestore(&tty->ctrl_lock, flags); } @@ -1387,7 +1387,8 @@ handle_newline: put_tty_queue(c, ldata); ldata->canon_head = ldata->read_head; kill_fasync(&tty->fasync, SIGIO, POLL_IN); - wake_up_interruptible_poll(&tty->read_wait, POLLIN); + if (waitqueue_active(&tty->read_wait)) + wake_up_interruptible_poll(&tty->read_wait, POLLIN); return 0; } } @@ -1670,7 +1671,8 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp, if ((!ldata->icanon && (read_cnt(ldata) >= ldata->minimum_to_wake)) || L_EXTPROC(tty)) { kill_fasync(&tty->fasync, SIGIO, POLL_IN); - wake_up_interruptible_poll(&tty->read_wait, POLLIN); + if (waitqueue_active(&tty->read_wait)) + wake_up_interruptible_poll(&tty->read_wait, POLLIN); } } @@ -1889,8 +1891,10 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) } /* The termios change make the tty ready for I/O */ - wake_up_interruptible(&tty->write_wait); - wake_up_interruptible(&tty->read_wait); + if (waitqueue_active(&tty->write_wait)) + wake_up_interruptible(&tty->write_wait); + if (waitqueue_active(&tty->read_wait)) + wake_up_interruptible(&tty->read_wait); } /** |