#define user_mode(regs) (((regs)->ps & 8) != 0)
#define instruction_pointer(regs) ((regs)->pc)
#define profile_pc(regs) instruction_pointer(regs)
+#define current_user_stack_pointer() rdusp()
#define task_pt_regs(task) \
((struct pt_regs *) (task_stack_page(task) + 2*PAGE_SIZE) - 1)