diff --git a/[refs] b/[refs]
index 4640e5a5299b..aff3835eb50d 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: b78032a7e52995b42d231d0064358eef16c9a8cc
+refs/heads/master: 77149367dade50af8370420265bd4f818cde8afd
diff --git a/trunk/arch/x86/kernel/microcode.c b/trunk/arch/x86/kernel/microcode.c
index 69729e38b78a..9f0a994eef9b 100644
--- a/trunk/arch/x86/kernel/microcode.c
+++ b/trunk/arch/x86/kernel/microcode.c
@@ -75,6 +75,7 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/cpumask.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -422,6 +423,7 @@ static int do_microcode_update (void)
 
 static int microcode_open (struct inode *unused1, struct file *unused2)
 {
+	cycle_kernel_lock();
 	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
 }