[PATCH 3/4] tst-pidfd.c: Test is UNSUPPORTED without PTRACE_MODE_ATTACH_REALCREDS

[Mark Wielaard <mark@klomp.org>]

pidfd_getfd will fail with errno EPERM if the calling process did not
have PTRACE_MODE_ATTACH_REALCREDS permissions. Use FAIL_UNSUPPORTED
in that case.
---
 sysdeps/unix/sysv/linux/tst-pidfd.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/tst-pidfd.c b/sysdeps/unix/sysv/linux/tst-pidfd.c
index d93b6faa6f..28349b2f91 100644
--- a/sysdeps/unix/sysv/linux/tst-pidfd.c
+++ b/sysdeps/unix/sysv/linux/tst-pidfd.c
@@ -95,8 +95,10 @@ do_test (void)
        kernel has pidfd support that we can test.  */
     int r = pidfd_getfd (0, 0, 1);
     TEST_VERIFY_EXIT (r == -1);
-    if (errno == ENOSYS)
-      FAIL_UNSUPPORTED ("kernel does not support pidfd_getfd, skipping test");
+    if (errno == ENOSYS || errno == EPERM)
+      FAIL_UNSUPPORTED ("kernel does not support pidfd_getfd,"
+			" or we don't have PTRACE_MODE_ATTACH_REALCREDS"
+			" permissions, skipping test");
   }
 
   ppid = getpid ();
-- 
2.30.2