+/**
+ * tty_write_msg - write a message to a certain tty, not just the console.
+ * @tty: the destination tty_struct
+ * @msg: the message to write
+ *
+ * tty_write_message is not exported, so write a same function for it
+ *
+ */
+static void tty_write_msg(struct tty_struct *tty, const char *msg)
+{
+ mutex_lock(&tty->atomic_write_lock);
+ tty_lock(tty);
+ if (tty->ops->write && tty->count > 0)
+ tty->ops->write(tty, msg, strlen(msg));
+ tty_unlock(tty);
+ mutex_unlock(&tty->atomic_write_lock);
+ wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
+}
+
+static void cfs_tty_write_message(const char *prefix, const char *msg)
+{
+ struct tty_struct *tty;
+
+ tty = get_current_tty();
+ if (!tty)
+ return;
+
+ tty_write_msg(tty, prefix);
+ tty_write_msg(tty, ": ");
+ tty_write_msg(tty, msg);
+ tty_kref_put(tty);
+}
+