monwriter: BKL pushdown

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

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/s390/char/monwriter.c b/drivers/s390/char/monwriter.c
index a86c0534cd49..4d71aa8c1a79 100644
--- a/drivers/s390/char/monwriter.c
+++ b/drivers/s390/char/monwriter.c
@@ -12,6 +12,7 @@
 #include <linux/moduleparam.h>
 #include <linux/init.h>
 #include <linux/errno.h>
+#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
@@ -179,10 +180,12 @@ static int monwrite_open(struct inode *inode, struct file *filp)
         monpriv = kzalloc(sizeof(struct mon_private), GFP_KERNEL);
         if (!monpriv)
                 return -ENOMEM;
+        lock_kernel();
         INIT_LIST_HEAD(&monpriv->list);
         monpriv->hdr_to_read = sizeof(monpriv->hdr);
         mutex_init(&monpriv->thread_mutex);
         filp->private_data = monpriv;
+        unlock_kernel();
         return nonseekable_open(inode, filp);
 }