Hi,
The bug https://bugzilla.suse.com/show_bug.cgi?id=1156053 is still open and thanks to Jiri the kernel feature is disabled by default on s390x, so the workaround will not be needed.
Git commit - https://git.io/JvW6W
Hardened usercopy - https://lwn.net/Articles/695991/
#cp disc