dn_spec
dnp->dn_spec = spec;
if (dtrace_xstr2desc(dtp, yypcb->pcb_pspec, dnp->dn_spec,
dnp->dn_spec, dtrace_errmsg(dtp, dtrace_errno(dtp)));
free(dnp->dn_spec);
dnp->dn_spec = NULL;
free(dnp->dn_spec);
dnp->dn_spec = NULL;