2013-07-23 19:07:07

by Henrik Nordström

[permalink] [raw]
Subject: [PATCH RESEND #1] 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 <[email protected]>
---
drivers/tty/serial/8250/8250_early.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
index 721904f..946ddd2 100644
--- 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);
- 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);
--
1.8.3.1