The later verions of the KAISER pathces (pre-PTI) allowed the user/kernel shared areas to be GLOBAL. The thought was that this would reduce the TLB overhead of keeping two copies of these mappings.
During the switch over to PTI, we seem to have lost our ability to have GLOBAL mappings. This adds them back. Cc: Andrea Arcangeli <aarca...@redhat.com> Cc: Andy Lutomirski <l...@kernel.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Kees Cook <keesc...@google.com> Cc: Hugh Dickins <hu...@google.com> Cc: Juergen Gross <jgr...@suse.com> Cc: x...@kernel.org Cc: Nadav Amit <na...@vmware.com>