[PATCH] staging: dgnc: take mutex when storing value in dgnc_poll_tick

Salah Triki salah.triki at acm.org
Mon Aug 17 15:19:12 UTC 2015


Since dgnc_poll_trick is a global variable.

Signed-off-by: Salah Triki <salah.triki at acm.org>
---
 drivers/staging/dgnc/dgnc_sysfs.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/dgnc/dgnc_sysfs.c b/drivers/staging/dgnc/dgnc_sysfs.c
index 44db870..fe14b7a 100644
--- a/drivers/staging/dgnc/dgnc_sysfs.c
+++ b/drivers/staging/dgnc/dgnc_sysfs.c
@@ -26,6 +26,7 @@
 #include "dgnc_driver.h"
 #include "dgnc_mgmt.h"
 
+#DEFINE_MUTEX(mut);
 
 static ssize_t dgnc_driver_version_show(struct device_driver *ddp, char *buf)
 {
@@ -58,10 +59,20 @@ static ssize_t dgnc_driver_pollrate_store(struct device_driver *ddp,
 {
 	int ret;
 
+	ret = mutex_lock_interruptible(&mut);
+
+	if (ret)
+		return -ERESTARTSYS;
+
 	ret = sscanf(buf, "%d\n", &dgnc_poll_tick);
 	if (ret != 1)
-		return -EINVAL;
-	return count;
+		ret = -EINVAL;
+	else
+		ret = count;
+
+	mutex_unlock(&mut);
+
+	return ret;
 }
 static DRIVER_ATTR(pollrate, (S_IRUSR | S_IWUSR), dgnc_driver_pollrate_show,
 		   dgnc_driver_pollrate_store);
-- 
1.9.1



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