SEL_RPL_MASK
testb $SEL_RPL_MASK,TF_CS(%rsp) ; /* come from kernel? */ \
testb $SEL_RPL_MASK,TF_CS(%rsp) ; /* come from kernel? */ \
cpl = cs & SEL_RPL_MASK;
rpl = sel & SEL_RPL_MASK;
ts->paging.cpl = tss->tss_cs & SEL_RPL_MASK;