Comment # 1 on bug 927725 from Jan Beulich

This is the result of cae2a173fe94ab3a437416af6f092fae2e65837e ("x86: clean
up/fix 'copy_in_user()' tail zeroing"). I can't, however, see how ftrace would
have worked even before - there ought to have been a respective
warning+calltrace in the boot messages even in earlier kernel versions. Petr -
why is SLE12's
patches.suse/ftrace-x86-xen-use-kernel-identity-mapping-only-when.patch not in
any newer kernel branch (for the case here namely in master and stable, but
afaict at least 13.2 would also want it)?