[PATCH] selftests/futex: Dynamically skip unsupported tests

[Wake Liu <wakel@google.com>]

Some new futex tests rely on kernel features that may not be supported
on all configurations (e.g., FUTEX2_NUMA or PR_FUTEX_HASH).
Currently, these tests fail with EINVAL when the features are missing.

This patch adds dynamic skip logic to:
1. futex_priv_hash: Skip if PR_FUTEX_HASH returns ENOSYS or EINVAL.
2. futex_numa_mpol: Skip if futex2 or FUTEX2_NUMA returns ENOSYS or EINVAL.

This allows the tests to pass (as SKIPPED) on kernels without support,
while preserving coverage on configurations that do support them.

Signed-off-by: Wake Liu <wakel@google.com>
---
 tools/testing/selftests/futex/functional/futex_numa_mpol.c | 2 ++
 tools/testing/selftests/futex/functional/futex_priv_hash.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/tools/testing/selftests/futex/functional/futex_numa_mpol.c b/tools/testing/selftests/futex/functional/futex_numa_mpol.c
index 78c0f7a59e17..d215acf88120 100644
--- a/tools/testing/selftests/futex/functional/futex_numa_mpol.c
+++ b/tools/testing/selftests/futex/functional/futex_numa_mpol.c
@@ -103,6 +103,8 @@ static void __test_futex(void *futex_ptr, int err_value, unsigned int futex_flag
 			break;
 		}
 		if (ret < 0) {
+			if (errno == ENOSYS || (errno == EINVAL && (futex_flags & FUTEX2_NUMA)))
+				ksft_exit_skip("futex2 or FUTEX2_NUMA not supported by kernel\n");
 			ksft_exit_fail_msg("Failed futex2_wake(%d, 0x%x): %m\n",
 					   to_wake, futex_flags);
 		}
diff --git a/tools/testing/selftests/futex/functional/futex_priv_hash.c b/tools/testing/selftests/futex/functional/futex_priv_hash.c
index e8079d7c65e8..27c3ea5ff3ed 100644
--- a/tools/testing/selftests/futex/functional/futex_priv_hash.c
+++ b/tools/testing/selftests/futex/functional/futex_priv_hash.c
@@ -145,6 +145,8 @@ TEST(priv_hash)
 	}
 	/* First thread, expect to be 0, not yet initialized */
 	ret = futex_hash_slots_get();
+	if (ret < 0 && errno == EINVAL)
+		ksft_exit_skip("PR_FUTEX_HASH not supported by kernel\n");
 	if (ret != 0)
 		ksft_exit_fail_msg("futex_hash_slots_get() failed: %d, %m\n", ret);
 
-- 
2.55.0.rc0.799.gd6f94ed593-goog