# \[PATCH 09/38\] selftests/timers: fix write return value handlng

- From: Andrzej Hajda \<hidden\>
- Date: 2015-09-21 13:52:29 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2015/09/4580146
- Thread: https://ratatoskr.run/linux-api/2015/09/6478795/t.md

```text
The function can return negative value.

The problem has been detected using proposed semantic patch
scripts/coccinelle/tests/unsigned_lesser_than_zero.cocci [1].

[1]: http://permalink.gmane.org/gmane.linux.kernel/2038576

Signed-off-by: Andrzej Hajda <redacted>
---
 tools/testing/selftests/timers/clocksource-switch.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/testing/selftests/timers/clocksource-switch.c b/tools/testing/selftests/timers/clocksource-switch.c
index 627ec74..fd88e30 100644
--- a/tools/testing/selftests/timers/clocksource-switch.c
+++ b/tools/testing/selftests/timers/clocksource-switch.c
@@ -97,7 +97,7 @@ int get_cur_clocksource(char *buf, size_t size)
 int change_clocksource(char *clocksource)
 {
 	int fd;
-	size_t size;
+	ssize_t size;
 
 	fd = open("/sys/devices/system/clocksource/clocksource0/current_clocksource", O_WRONLY);
 
-- 
1.9.1
```