diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c
index 8a111ab33b507a745e01523148b536cb2444861b..93d3a0ec5e112138fe46f7f3fea5c0882da20468 100644
--- a/drivers/tty/serial/kgdboc.c
+++ b/drivers/tty/serial/kgdboc.c
@@ -230,7 +230,7 @@ static void kgdboc_put_char(u8 chr)
 static int param_set_kgdboc_var(const char *kmessage,
 				const struct kernel_param *kp)
 {
-	int len = strlen(kmessage);
+	size_t len = strlen(kmessage);
 
 	if (len >= MAX_CONFIG_LEN) {
 		printk(KERN_ERR "kgdboc: config string too long\n");
@@ -252,7 +252,7 @@ static int param_set_kgdboc_var(const char *kmessage,
 
 	strcpy(config, kmessage);
 	/* Chop out \n char as a result of echo */
-	if (config[len - 1] == '\n')
+	if (len && config[len - 1] == '\n')
 		config[len - 1] = '\0';
 
 	if (configured == 1)