selftests/namespaces: Skip efault tests when listns() is not available

When listns() is not implemented the iterator child detects ENOSYS and
exits cleanly with status PIDFD_SKIP before the parent has a chance to
signal it.  The parent sends SIGKILL (which is a harmless no-op at that
point) and then calls waitpid(), obtaining a normal-exit status.  The
subsequent ASSERT_TRUE(WIFSIGNALED(status)) therefore fails, causing the
three EFAULT-focused tests to report FAIL rather than SKIP on kernels that
do not yet carry listns() support.

After collecting the iterator's exit status, check whether it exited with
PIDFD_SKIP and issue a SKIP verdict in that case, consistent with the
behaviour of every other listns test that already handles ENOSYS correctly.

Signed-off-by: Ricardo B. Marlière <rbm@suse.com>
Link: https://patch.msgid.link/20260407-selftests-namespaces_fixes-v1-3-59109909d88b@suse.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/tools/testing/selftests/namespaces/listns_efault_test.c b/tools/testing/selftests/namespaces/listns_efault_test.c
index 8df5397adbb0da902077dd330551b71b5772336a..26b452c98c665adf4f94ae10220ca49492b01598 100644 (file)
--- a/tools/testing/selftests/namespaces/listns_efault_test.c
+++ b/tools/testing/selftests/namespaces/listns_efault_test.c
@@ -176,6 +176,12 @@ TEST(listns_partial_fault_with_ns_cleanup)
        ASSERT_EQ(ret, iter_pid);
        close(iter_pidfd);
 
+       /* If listns() is not supported the iterator exits cleanly via ENOSYS */
+       if (WIFEXITED(status) && WEXITSTATUS(status) == PIDFD_SKIP) {
+               munmap(map, page_size);
+               SKIP(return, "listns() not supported");
+       }
+
        /* Should have been killed */
        ASSERT_TRUE(WIFSIGNALED(status));
        ASSERT_EQ(WTERMSIG(status), SIGKILL);
@@ -386,6 +392,12 @@ TEST(listns_late_fault_with_ns_cleanup)
        ASSERT_EQ(ret, iter_pid);
        close(iter_pidfd);
 
+       /* If listns() is not supported the iterator exits cleanly via ENOSYS */
+       if (WIFEXITED(status) && WEXITSTATUS(status) == PIDFD_SKIP) {
+               munmap(map, page_size);
+               SKIP(return, "listns() not supported");
+       }
+
        /* Should have been killed */
        ASSERT_TRUE(WIFSIGNALED(status));
        ASSERT_EQ(WTERMSIG(status), SIGKILL);
@@ -522,6 +534,12 @@ TEST(listns_mnt_ns_cleanup_on_fault)
        ASSERT_EQ(ret, iter_pid);
        close(iter_pidfd);
 
+       /* If listns() is not supported the iterator exits cleanly via ENOSYS */
+       if (WIFEXITED(status) && WEXITSTATUS(status) == PIDFD_SKIP) {
+               munmap(map, page_size);
+               SKIP(return, "listns() not supported");
+       }
+
        /* Should have been killed */
        ASSERT_TRUE(WIFSIGNALED(status));
        ASSERT_EQ(WTERMSIG(status), SIGKILL);