+/* runs on IST stack. */
+asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
+{
+ if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
+ return;
+ }
+ preempt_conditional_sti(regs);
+ do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
+ preempt_conditional_cli(regs);
+}
+
+/* Help handler running on IST stack to switch back to user stack
+ for scheduling or signal handling. The actual stack switch is done in
+ entry.S */
+asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
+{
+ struct pt_regs *regs = eregs;
+ /* Did already sync */
+ if (eregs == (struct pt_regs *)eregs->rsp)
+ ;
+ /* Exception from user space */
+ else if (user_mode(eregs))
+ regs = task_pt_regs(current);
+ /* Exception from kernel and interrupts are enabled. Move to
+ kernel process stack. */
+ else if (eregs->eflags & X86_EFLAGS_IF)
+ regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
+ if (eregs != regs)
+ *regs = *eregs;
+ return regs;