xilinx icap: BKL pushdown

Add explicit lock_kernel() calls to hwicap_open() even though the existing
locking looks adequate.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

1 files changed, 5 insertions, 1 deletions

diff --git a/drivers/char/xilinx_hwicap/xilinx_hwicap.c b/drivers/char/xilinx_hwicap/xilinx_hwicap.c
index 3edf1fc12963..1e1b81e57cdc 100644
--- a/drivers/char/xilinx_hwicap/xilinx_hwicap.c
+++ b/drivers/char/xilinx_hwicap/xilinx_hwicap.c
@@ -85,6 +85,7 @@
 #include <linux/poll.h>
 #include <linux/proc_fs.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 #include <linux/sysctl.h>
 #include <linux/version.h>
 #include <linux/fs.h>
@@ -504,11 +505,12 @@ static int hwicap_open(struct inode *inode, struct file *file)
         struct hwicap_drvdata *drvdata;
         int status;
 
+        lock_kernel();
         drvdata = container_of(inode->i_cdev, struct hwicap_drvdata, cdev);
 
         status = mutex_lock_interruptible(&drvdata->sem);
         if (status)
-                return status;
+                goto out;
 
         if (drvdata->is_open) {
                 status = -EBUSY;
@@ -528,6 +530,8 @@ static int hwicap_open(struct inode *inode, struct file *file)
 
  error:
         mutex_unlock(&drvdata->sem);
+ out:
+        unlock_kernel();
         return status;
 }