tty/8250_early: Don't truncate last character of options

The earlier change to use strlcpy uncovered a bug in the options
argument length calculation causing last character to be truncated.
This makes the actual console to be configured with incorrect
baudrate when specifying the console using console=uart,... syntax.

Bug symptom seen in kernel log output:

Kernel command line: console=uart,mmio,0x90000000,115200
Early serial console at MMIO 0x90000000 (options '11520')

which then results in a invalid baud rate 11520 instead of the
expected 115200 when the console is switched to ttyS0 later
in the boot process.

Signed-off-by: Henrik Nordstrom <henrik@henriknordstrom.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index 721904f8efa92b8816665410822b355619679f47..946ddd2b3a541990277aabad488843a429e3e6f5 100644 (file)
--- a/drivers/tty/serial/8250/8250_early.c
+++ b/drivers/tty/serial/8250/8250_early.c
@@ -193,7 +193,8 @@ static int __init parse_options(struct early_serial8250_device *device,
        if (options) {
                options++;
                device->baud = simple_strtoul(options, NULL, 0);
        if (options) {
                options++;
                device->baud = simple_strtoul(options, NULL, 0);

-               length = min(strcspn(options, " "), sizeof(device->options));
+               length = min(strcspn(options, " ") + 1,
+                            sizeof(device->options));

                strlcpy(device->options, options, length);
        } else {
                device->baud = probe_baud(port);
                strlcpy(device->options, options, length);
        } else {
                device->baud = probe_baud(port);