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-rw-r--r--drivers/s390/char/vmwatchdog.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/s390/char/vmwatchdog.c b/drivers/s390/char/vmwatchdog.c
index 19f8389..ee80e93 100644
--- a/drivers/s390/char/vmwatchdog.c
+++ b/drivers/s390/char/vmwatchdog.c
@@ -13,6 +13,7 @@
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/watchdog.h>
+#include <linux/smp_lock.h>
#include <asm/ebcdic.h>
#include <asm/io.h>
@@ -131,11 +132,15 @@ static int __init vmwdt_probe(void)
static int vmwdt_open(struct inode *i, struct file *f)
{
int ret;
- if (test_and_set_bit(0, &vmwdt_is_open))
+ lock_kernel();
+ if (test_and_set_bit(0, &vmwdt_is_open)) {
+ unlock_kernel();
return -EBUSY;
+ }
ret = vmwdt_keepalive();
if (ret)
clear_bit(0, &vmwdt_is_open);
+ unlock_kernel();
return ret ? ret : nonseekable_open(i, f);
}