DUP_FIXED
if ((flags & DUP_FIXED) && old == new) {
KASSERT(delfp == NULL || (flags & DUP_FIXED),
error = kern_dup(DUP_FIXED, devnull, i, &retval);
error = kern_dup(DUP_FIXED, uap->from, uap->to, &fd);
error = kern_dup(DUP_FIXED, fd, newmin, &dat->fc_fd);
error = kern_dup(DUP_FIXED | DUP_CLOEXEC, fd, newmin,
error = kern_dup(DUP_FIXED | DUP_CLOFORK, fd, newmin,
error = kern_dup(DUP_FIXED |