tty: Wait interruptibly for tty lock on reopen

[firefly-linux-kernel-4.4.55.git] / drivers / tty / tty_io.c

diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index bcc8e1e8bb720996cf73438c67a397362173edca..4d34116842a66f88ec515e1218dd7360a77ccdf1 100644 (file)
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -2069,7 +2069,12 @@ retry_open:
 
                if (tty) {
                        mutex_unlock(&tty_mutex);
-                       tty_lock(tty);
+                       retval = tty_lock_interruptible(tty);
+                       if (retval) {
+                               if (retval == -EINTR)
+                                       retval = -ERESTARTSYS;
+                               goto err_unref;
+                       }
                        /* safe to drop the kref from tty_driver_lookup_tty() */
                        tty_kref_put(tty);
                        retval = tty_reopen(tty);
@@ -2156,6 +2161,7 @@ retry_open:
        return 0;
 err_unlock:
        mutex_unlock(&tty_mutex);
+err_unref:
        /* after locks to avoid deadlock */
        if (!IS_ERR_OR_NULL(driver))
                tty_driver_kref_put(driver);