PER_EVENT_STORE
if (!(current->thread.per_user.control & PER_EVENT_STORE))
current->thread.per_event.cause = PER_EVENT_STORE >> 16;
if (*cr9 & PER_EVENT_STORE && *cr9 & PER_CONTROL_ALTERATION) {
*cr9 |= PER_EVENT_STORE;
#define PER_CODE_STORE (PER_EVENT_STORE >> 24)