briq_panel: BKL pushdown

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

1 files changed, 7 insertions, 2 deletions

diff --git a/drivers/char/briq_panel.c b/drivers/char/briq_panel.c
index b6f2639f903d..d8cff909001c 100644
--- a/drivers/char/briq_panel.c
+++ b/drivers/char/briq_panel.c
@@ -6,6 +6,7 @@
 
 #include <linux/module.h>
 
+#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/tty.h>
@@ -67,11 +68,15 @@ static void set_led(char state)
 
 static int briq_panel_open(struct inode *ino, struct file *filep)
 {
-        /* enforce single access */
-        if (vfd_is_open)
+        lock_kernel();
+        /* enforce single access, vfd_is_open is protected by BKL */
+        if (vfd_is_open) {
+                unlock_kernel();
                 return -EBUSY;
+        }
         vfd_is_open = 1;
 
+        unlock_kernel();
         return 0;
 }