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Diffstat (limited to 'tools/testing/selftests/mm/ksm_functional_tests.c')
-rw-r--r--tools/testing/selftests/mm/ksm_functional_tests.c28
1 files changed, 26 insertions, 2 deletions
diff --git a/tools/testing/selftests/mm/ksm_functional_tests.c b/tools/testing/selftests/mm/ksm_functional_tests.c
index b61803e36d1c..d8bd1911dfc0 100644
--- a/tools/testing/selftests/mm/ksm_functional_tests.c
+++ b/tools/testing/selftests/mm/ksm_functional_tests.c
@@ -393,9 +393,13 @@ static void test_unmerge_uffd_wp(void)
/* See if UFFD-WP is around. */
uffdio_api.api = UFFD_API;
- uffdio_api.features = UFFD_FEATURE_PAGEFAULT_FLAG_WP;
+ uffdio_api.features = 0;
if (ioctl(uffd, UFFDIO_API, &uffdio_api) < 0) {
- ksft_test_result_fail("UFFDIO_API failed\n");
+ if (errno == EINVAL)
+ ksft_test_result_skip("The API version requested is not supported\n");
+ else
+ ksft_test_result_fail("UFFDIO_API failed: %s\n", strerror(errno));
+
goto close_uffd;
}
if (!(uffdio_api.features & UFFD_FEATURE_PAGEFAULT_FLAG_WP)) {
@@ -403,6 +407,26 @@ static void test_unmerge_uffd_wp(void)
goto close_uffd;
}
+ /*
+ * UFFDIO_API must only be called once to enable features.
+ * So we close the old userfaultfd and create a new one to
+ * actually enable UFFD_FEATURE_PAGEFAULT_FLAG_WP.
+ */
+ close(uffd);
+ uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
+ if (uffd < 0) {
+ ksft_test_result_fail("__NR_userfaultfd failed\n");
+ goto unmap;
+ }
+
+ /* Now, enable it ("two-step handshake") */
+ uffdio_api.api = UFFD_API;
+ uffdio_api.features = UFFD_FEATURE_PAGEFAULT_FLAG_WP;
+ if (ioctl(uffd, UFFDIO_API, &uffdio_api) < 0) {
+ ksft_test_result_fail("UFFDIO_API failed: %s\n", strerror(errno));
+ goto close_uffd;
+ }
+
/* Register UFFD-WP, no need for an actual handler. */
if (uffd_register(uffd, map, size, false, true, false)) {
ksft_test_result_fail("UFFDIO_REGISTER_MODE_WP failed\n");