ea6020830c
The flush is needed to prevent cross-process ret2spec, which is not handled on kernel entry if IBPB is enabled but SMEP is present. While there, add i386 RSB flush. Reported by: Anthony Steinhauser <asteinhauser@google.com> Reviewed by: markj, Anthony Steinhauser Discussed with: philip admbugs: 961 Sponsored by: The FreeBSD Foundation MFC after: 1 week