selftests: mm: skip whole test instead of failure

Some architectures don't support userfaultfd.  Skip running the whole test
on them instead of registering the failure.

Link: https://lkml.kernel.org/r/20231103182343.2874015-1-usama.anjum@collabora.com
Fixes: 46fd75d ("selftests: mm: add pagemap ioctl tests")

Reported-by: Ryan Roberts <ryan.roberts@arm.com>
Closes: https://lore.kernel.org/all/f8463381-2697-49e9-9460-9dc73452830d@arm.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Muhammad Usama Anjum

tools/testing/selftests/mm/pagemap_ioctl.c

@@ -94,19 +94,19 @@ int init_uffd(void)
 
 	uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
 	if (uffd == -1)
-		ksft_exit_fail_msg("uffd syscall failed\n");
+		return uffd;
 
 	uffdio_api.api = UFFD_API;
 	uffdio_api.features = UFFD_FEATURE_WP_UNPOPULATED | UFFD_FEATURE_WP_ASYNC |
 			      UFFD_FEATURE_WP_HUGETLBFS_SHMEM;
 	if (ioctl(uffd, UFFDIO_API, &uffdio_api))
-		ksft_exit_fail_msg("UFFDIO_API\n");
+		return -1;
 
 	if (!(uffdio_api.api & UFFDIO_REGISTER_MODE_WP) ||
 	    !(uffdio_api.features & UFFD_FEATURE_WP_UNPOPULATED) ||
 	    !(uffdio_api.features & UFFD_FEATURE_WP_ASYNC) ||
 	    !(uffdio_api.features & UFFD_FEATURE_WP_HUGETLBFS_SHMEM))
-		ksft_exit_fail_msg("UFFDIO_API error %llu\n", uffdio_api.api);
+		return -1;
 
 	return 0;
 }
@@ -1479,6 +1479,10 @@ int main(void)
 	struct stat sbuf;
 
 	ksft_print_header();
+
+	if (init_uffd())
+		return ksft_exit_pass();
+
 	ksft_set_plan(115);
 
 	page_size = getpagesize();
@@ -1488,9 +1492,6 @@ int main(void)
 	if (pagemap_fd < 0)
 		return -EINVAL;
 
-	if (init_uffd())
-		ksft_exit_fail_msg("uffd init failed\n");
-
 	/* 1. Sanity testing */
 	sanity_tests_sd();