···100100 ; 2. Upon entry SP is always saved (for any inspection, unwinding etc),101101 ; but on return, restored only if U mode102102103103+ lr r9, [AUX_USER_SP] ; U mode SP104104+103105 mov.nz r9, sp104106 add.nz r9, r9, SZ_PT_REGS - PT_sp - 4 ; K mode SP105105- bnz 1f106107107107- lr r9, [AUX_USER_SP] ; U mode SP108108-1:109108 PUSH r9 ; SP (pt_regs->sp)110109111110 PUSH fp