+ /* Security check:
+ * If the priority level is still user, and the
+ * faulting space is not equal to the active space
+ * then the user is attempting something in a space
+ * that does not belong to them. Kill the process.
+ *
+ * This is normally the situation when the user
+ * attempts to jump into the kernel space at the
+ * wrong offset, be it at the gateway page or a
+ * random location.
+ *
+ * We cannot normally signal the process because it
+ * could *be* on the gateway page, and processes
+ * executing on the gateway page can't have signals
+ * delivered.
+ *
+ * We merely readjust the address into the users
+ * space, at a destination address of zero, and
+ * allow processing to continue.
+ */
+ if (((unsigned long)regs->iaoq[0] & 3) &&
+ ((unsigned long)regs->iasq[0] != (unsigned long)regs->sr[7])) {
+ /* Kill the user process later */
+ regs->iaoq[0] = 0 | 3;
+ regs->iaoq[1] = regs->iaoq[0] + 4;
+ regs->iasq[0] = regs->iasq[0] = regs->sr[7];
+ regs->gr[0] &= ~PSW_B;
+ return;
+ }
+