dup_fd            112 include/linux/fdtable.h struct files_struct *dup_fd(struct files_struct *, int *) __latent_entropy;
dup_fd           1463 kernel/fork.c  	newf = dup_fd(oldf, &error);
dup_fd           2793 kernel/fork.c  		*new_fdp = dup_fd(fd, &error);