loadseg
loadseg(which, __USER_DS);
loadseg(which, next_index);
loadseg(which, next_index);
loadseg(which, next_index);
loadseg(which, next_index);
loadseg(FS, next->fsindex);
loadseg(GS, next->gsindex);
loadseg(GS, 0);
loadseg(FS, 0);