[PATCH v2 3/5] tests/futex: Add support for return codes other than 0 and -1 to sprintrc

[Eugene Syromyatnikov]

* tests/futex.c (sprintrc): Print the actual return code provided, not
  just "0"; checks for snprintf return code added.
---
 tests/futex.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/tests/futex.c b/tests/futex.c
index 28d9df8..09a6c25 100644
--- a/tests/futex.c
+++ b/tests/futex.c
@@ -150,7 +150,15 @@ const char *sprintrc(long rc)
 	if (rc == 0)
 		return "0";
 
-	snprintf(buf, sizeof(buf), "-1 %s (%m)", errno2name());
+	int ret = (rc == -1)
+		? snprintf(buf, sizeof(buf), "-1 %s (%m)", errno2name())
+		: snprintf(buf, sizeof(buf), "%ld", rc);
+
+	if (ret < 0)
+		perror_msg_and_fail("snprintf");
+	if ((size_t) ret >= sizeof(buf))
+		error_msg_and_fail("snprintf overflow: got %d, expected "
+			"no more than %zu", ret, sizeof(buf));
 
 	return buf;
 }
-- 
1.7.10.4