Merge 4.16-rc6 into tty-next

We want the serial/tty fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index eb9133b472f4..63114ea35ec1 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -586,6 +586,14 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
                 return;
         }
 
+        /*
+         * Some console devices aren't actually hung up for technical and
+         * historical reasons, which can lead to indefinite interruptible
+         * sleep in n_tty_read().  The following explicitly tells
+         * n_tty_read() to abort readers.
+         */
+        set_bit(TTY_HUPPING, &tty->flags);
+
         /* inuse_filps is protected by the single tty lock,
            this really needs to change if we want to flush the
            workqueue with the lock held */
@@ -640,6 +648,7 @@ static void __tty_hangup(struct tty_struct *tty, int exit_session)
          * from the ldisc side, which is now guaranteed.
          */
         set_bit(TTY_HUPPED, &tty->flags);
+        clear_bit(TTY_HUPPING, &tty->flags);
         tty_unlock(tty);
 
         if (f)