diff --git a/[refs] b/[refs]
index 055e1b999fc1..af47073a3ece 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 1371c893ff9de0d57fa5b5cf0255d66b8849e13d
+refs/heads/master: f0df2d6b52ad7db5edf56909509d51be66fe90be
diff --git a/trunk/drivers/acpi/tables.c b/trunk/drivers/acpi/tables.c
index c3419182c9a7..775c97a282bd 100644
--- a/trunk/drivers/acpi/tables.c
+++ b/trunk/drivers/acpi/tables.c
@@ -300,6 +300,8 @@ int __init acpi_table_init(void)
 
 static int __init acpi_parse_apic_instance(char *str)
 {
+	if (!str)
+		return -EINVAL;
 
 	acpi_apic_instance = simple_strtoul(str, NULL, 0);