Comment 6 for bug 1853852

Uh there is something related as Ubuntu Delta:

From: Balint Reczey <email address hidden>
Date: Tue, 22 Oct 2019 17:10:17 +0200
Subject: test: expect mmap to fail in seccomp test on s390 and s390x

(cherry picked from commit a81f7aad9a5ddeebbce002e2da36e1dd84f51b36)
---
 src/test/test-seccomp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/test/test-seccomp.c b/src/test/test-seccomp.c
index a906070..9881768 100644
--- a/src/test/test-seccomp.c
+++ b/src/test/test-seccomp.c
@@ -489,7 +489,7 @@ static void test_memory_deny_write_execute_mmap(void) {
                 assert_se(seccomp_memory_deny_write_execute() >= 0);

                 p = mmap(NULL, page_size(), PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, -1,0);
-#if defined(__x86_64__) || defined(__i386__) || defined(__powerpc64__) || defined(__arm__) || defined(__aarch64__)
+#if defined(__x86_64__) || defined(__i386__) || defined(__powerpc64__) || defined(__arm__) || defined(__aarch64__) || defined(__s390__) || defined(__s390x__)
                 assert_se(p == MAP_FAILED);
                 assert_se(errno == EPERM);
 #else /* unknown architectures */

Maybe that isn't true anymore?
In any case it could explain why upstream might not see/discuss about it.
But then OTOH remember that 32bit seems to be affected the same way