[PATCH 3/5] serial: core: always return in-range baud rate even in case of failure

[Hugo Villeneuve]

From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>

Returning a zero baud rate from uart_get_baud_rate() can trigger a division
by zero fault. To prevent this, always make sure to return non-zero baud
rate if the loop exits without a valid baud rate.

Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
---
 drivers/tty/serial/serial_core.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 0498a8524c6da..d9ed7db53e68d 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -542,8 +542,9 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios,
 	}
 
 	/* Should never happen */
-	WARN_ON(1);
-	return 0;
+	dev_warn_ratelimited(port->dev, "%s (%u): unable to find fallback baud rate\n",
+			     port->name, port->line);
+	return baud;
 }
 EXPORT_SYMBOL(uart_get_baud_rate);
 
-- 
2.47.3