selftests/mm: skip uffd-stress if userfaultfd not available

It's pretty obvious that the test wouldn't work if you don't have the
feature enabled.  But, it's still useful to SKIP instead of failing so the
reader can immediately tell that this is the reason why.

Link: https://lkml.kernel.org/r/20250311-mm-selftests-v4-2-dec210a658f5@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index 944d559..91174e9 100644 (file)
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -412,8 +412,8 @@ static void parse_test_type_arg(const char *raw_type)
         * feature.
         */
 
-       if (uffd_get_features(&features))
-               err("failed to get available features");
+       if (uffd_get_features(&features) && errno == ENOENT)
+               ksft_exit_skip("failed to get available features (%d)\n", errno);
 
        test_uffdio_wp = test_uffdio_wp &&
                (features & UFFD_FEATURE_PAGEFAULT_FLAG_WP);