[PATCH 1/2] Fix cg_read_strcmp()

[<jgkamat@fb.com>]

From: Jay Kamat <jgkamat@fb.com>

Fix a couple issues with cg_read_strcmp(), to improve correctness of
cgroup tests
- Fix cg_read_strcmp() always returning 0 for empty "needle" strings
- Fix a memory leak in cg_read_strcmp()

Fixes: 84092dbcf901 ("selftests: cgroup: add memory controller self-tests")

Signed-off-by: Jay Kamat <jgkamat@fb.com>
---
 tools/testing/selftests/cgroup/cgroup_util.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c
index 1e9e3c470561..4aadf38bcd5d 100644
--- a/tools/testing/selftests/cgroup/cgroup_util.c
+++ b/tools/testing/selftests/cgroup/cgroup_util.c
@@ -91,15 +91,24 @@ int cg_read_strcmp(const char *cgroup, const char *control,
 {
 	size_t size = strlen(expected) + 1;
 	char *buf;
+	int ret;
+
+	/* Handle the case of comparing against empty string */
+	if (size == 1)
+		size = 32;
 
 	buf = malloc(size);
 	if (!buf)
 		return -1;
 
-	if (cg_read(cgroup, control, buf, size))
+	if (cg_read(cgroup, control, buf, size)) {
+		free(buf);
 		return -1;
+	}
 
-	return strcmp(expected, buf);
+	ret = strcmp(expected, buf);
+	free(buf);
+	return ret;
 }
 
 int cg_read_strstr(const char *cgroup, const char *control, const char *needle)
-- 
2.17.1