monreader: BKL pushdown

[jmc: added <linux/smp_lock.h>]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/s390/char/monreader.c b/drivers/s390/char/monreader.c
index 1e1f50655bbf..dc4710e64e0c 100644
--- a/drivers/s390/char/monreader.c
+++ b/drivers/s390/char/monreader.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/init.h>
+#include <linux/smp_lock.h>
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/kernel.h>
@@ -340,6 +341,7 @@ static int mon_open(struct inode *inode, struct file *filp)
         /*
          * only one user allowed
          */
+        lock_kernel();
         rc = -EBUSY;
         if (test_and_set_bit(MON_IN_USE, &mon_in_use))
                 goto out;
@@ -377,6 +379,7 @@ static int mon_open(struct inode *inode, struct file *filp)
         }
         P_INFO("open, established connection to *MONITOR service\n\n");
         filp->private_data = monpriv;
+        unlock_kernel();
         return nonseekable_open(inode, filp);
 
 out_path:
@@ -386,6 +389,7 @@ out_priv:
 out_use:
         clear_bit(MON_IN_USE, &mon_in_use);
 out:
+        unlock_kernel();
         return rc;
 }