x86-mce: BKL pushdown

Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce_64.c b/arch/x86/kernel/cpu/mcheck/mce_64.c
index e07e8c068ae0..4ef151633e8b 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_64.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_64.c
@@ -9,6 +9,7 @@
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/sched.h>
+#include <linux/smp_lock.h>
 #include <linux/string.h>
 #include <linux/rcupdate.h>
 #include <linux/kallsyms.h>
@@ -527,10 +528,12 @@ static int open_exclu;	/* already open exclusive? */
 
 static int mce_open(struct inode *inode, struct file *file)
 {
+        lock_kernel();
         spin_lock(&mce_state_lock);
 
         if (open_exclu || (open_count && (file->f_flags & O_EXCL))) {
                 spin_unlock(&mce_state_lock);
+                unlock_kernel();
                 return -EBUSY;
         }
 
@@ -539,6 +542,7 @@ static int mce_open(struct inode *inode, struct file *file)
         open_count++;
 
         spin_unlock(&mce_state_lock);
+        unlock_kernel();
 
         return nonseekable_open(inode, file);
 }