TSEG_GS
setsegment(&pcb->pcb_threadsegs[TSEG_GS], 0,
curcpu()->ci_gdt[GUGS_SEL].sd = pcb->pcb_threadsegs[TSEG_GS];
self->ci_gdt[GUGS_SEL].sd = pcb->pcb_threadsegs[TSEG_GS];
uint32_t base = i386_get_threadbase(p, TSEG_GS);
error = i386_set_threadbase(p, base, TSEG_GS);
i386_set_threadbase(p2, (uint32_t)tcb, TSEG_GS);
((void *)i386_get_threadbase(p, TSEG_GS))
i386_set_threadbase(p, (uint32_t)(addr), TSEG_GS)