https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79341
--- Comment #28 from Jakub Jelinek <jakub at gcc dot gnu.org> --- The bug has been introduced in http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/arch/s390/include/asm/mmu_context.h?id=6252d702c5311ce916caf75ed82e5c8245171c92 so I assume kernels 2.6.24 and earlier should be ok (unless some distro backported the dynamic s390 page tables). Though maybe that old kernels just don't support 4 level page tables at all.
