serial: sh-sci: prevent setup of uninitialized serial console

Commit 906b17dc089f7fa87e37a9cfe6ee185efc90e0da introduced a condition
where the kernel will crash unless a earlyprintk parameter is specified.

Without this parameter, sci_console_init is called during early console
setup without any port being initialized, and the kernel crashes a
little bit later when uart_set_options attemps to invoke set_termios on a
port with an ops member equal to NULL.

This patch just checks in sci_console_init that the port is properly
initialized, and aborts the early console setup if it is not.

Signed-off-by: Alexandre Courbot <gnurou@gmail.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index eb7958c675a8..264209c32675 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1836,6 +1836,12 @@ static int __devinit serial_console_setup(struct console *co, char *options)
         sci_port = &sci_ports[co->index];
         port = &sci_port->port;
 
+        /*
+         * Refuse to handle uninitialized ports.
+         */
+        if (!port->ops)
+                return -ENODEV;
+
         ret = sci_remap_port(port);
         if (unlikely(ret != 0))
                 return ret;