1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c
index a5d8bcb40000..e1fc193d9396 100644
--- a/drivers/char/tpm/tpm.c
+++ b/drivers/char/tpm/tpm.c
@@ -26,6 +26,7 @@
 #include <linux/poll.h>
 #include <linux/mutex.h>
 #include <linux/spinlock.h>
+#include <linux/smp_lock.h>
 
 #include "tpm.h"
 
@@ -897,6 +898,7 @@ int tpm_open(struct inode *inode, struct file *file)
         int rc = 0, minor = iminor(inode);
         struct tpm_chip *chip = NULL, *pos;
 
+        lock_kernel();
         spin_lock(&driver_lock);
 
         list_for_each_entry(pos, &tpm_chip_list, list) {
@@ -926,16 +928,19 @@ int tpm_open(struct inode *inode, struct file *file)
         if (chip->data_buffer == NULL) {
                 chip->num_opens--;
                 put_device(chip->dev);
+                unlock_kernel();
                 return -ENOMEM;
         }
 
         atomic_set(&chip->data_pending, 0);
 
         file->private_data = chip;
+        unlock_kernel();
         return 0;
 
 err_out:
         spin_unlock(&driver_lock);
+        unlock_kernel();
         return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_open);