Verify that we report ENOENT when userspace tries to create a
thread-group leader pidfd for a thread pidfd that isn't a thread-group
leader.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 tools/testing/selftests/pidfd/pidfd_info_test.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/testing/selftests/pidfd/pidfd_info_test.c b/tools/testing/selftests/pidfd/pidfd_info_test.c
index accfd6bdc539..a0eb6e81eaa2 100644
--- a/tools/testing/selftests/pidfd/pidfd_info_test.c
+++ b/tools/testing/selftests/pidfd/pidfd_info_test.c
@@ -299,6 +299,7 @@ TEST_F(pidfd_info, thread_group)
 	/* Opening a thread as a thread-group leader must fail. */
 	pidfd_thread = sys_pidfd_open(pid_thread, 0);
 	ASSERT_LT(pidfd_thread, 0);
+	ASSERT_EQ(errno, ENOENT);
 
 	/* Opening a thread as a PIDFD_THREAD must succeed. */
 	pidfd_thread = sys_pidfd_open(pid_thread, PIDFD_THREAD);

-- 
2.47.2