[PATCH 07/20] intel_th: msu: Release resources on read error

[Alexander Shishkin <alexander.shishkin@linux.intel.com>]

From: Laurent FERT <laurent.fert@intel.com>

Right now, reading from msc character device will leak its's user count
on read error.

This patch makes sure resources are released when there is no data left
to read from the buffer.

Signed-off-by: Laurent FERT <laurent.fert@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
---
 drivers/hwtracing/intel_th/msu.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/hwtracing/intel_th/msu.c b/drivers/hwtracing/intel_th/msu.c
index 3c793bbf6a..d9d6022c5a 100644
--- a/drivers/hwtracing/intel_th/msu.c
+++ b/drivers/hwtracing/intel_th/msu.c
@@ -1112,12 +1112,11 @@ static ssize_t intel_th_msc_read(struct file *file, char __user *buf,
 		size = msc->nr_pages << PAGE_SHIFT;
 
 	if (!size)
-		return 0;
+		goto put_count;
 
-	if (off >= size) {
-		len = 0;
+	if (off >= size)
 		goto put_count;
-	}
+
 	if (off + len >= size)
 		len = size - off;
 
-- 
2.7.0