[PATCH v4 23/30] selftests/landlock: Extend tests for landlock_restrict_self()'s flags

[Mickaël Salaün]

Add the restrict_self_flags test suite to check that
LANDLOCK_RESTRICT_SELF_QUIET is valid but not the next bit.  Some checks
are similar to restrict_self_checks_ordering's ones.

Cc: Günther Noack <gnoack@xxxxxxxxxx>
Signed-off-by: Mickaël Salaün <mic@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20250108154338.1129069-24-mic@xxxxxxxxxxx
---

Changes since v3:
- Use a last_flag variable.

Changes since v2:
- New patch.
---
 tools/testing/selftests/landlock/base_test.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tools/testing/selftests/landlock/base_test.c b/tools/testing/selftests/landlock/base_test.c
index fbd687691b3c..1a1603ff178b 100644
--- a/tools/testing/selftests/landlock/base_test.c
+++ b/tools/testing/selftests/landlock/base_test.c
@@ -233,6 +233,23 @@ TEST(restrict_self_checks_ordering)
 	ASSERT_EQ(0, close(ruleset_fd));
 }
 
+TEST(restrict_self_flags)
+{
+	const __u32 last_flag = LANDLOCK_RESTRICT_SELF_QUIET;
+
+	ASSERT_EQ(-1, landlock_restrict_self(-1, 0));
+	ASSERT_EQ(EBADF, errno);
+
+	ASSERT_EQ(-1, landlock_restrict_self(-1, LANDLOCK_RESTRICT_SELF_QUIET));
+	ASSERT_EQ(EBADF, errno);
+
+	ASSERT_EQ(-1, landlock_restrict_self(-1, last_flag << 1));
+	ASSERT_EQ(EINVAL, errno);
+
+	ASSERT_EQ(-1, landlock_restrict_self(-1, -1));
+	ASSERT_EQ(EINVAL, errno);
+}
+
 TEST(ruleset_fd_io)
 {
 	struct landlock_ruleset_attr ruleset_attr = {
-- 
2.47.1