int nvlist_xalloc(nvlist_t **, uint_t, nv_alloc_t *);
int nvlist_xpack(nvlist_t *, char **, size_t *, int, nv_alloc_t *);
int nvlist_xunpack(char *, size_t, nvlist_t **, nv_alloc_t *);
int nvlist_xalloc(nvlist_t **, uint_t, nv_alloc_t *);
int nvlist_xpack(nvlist_t *, char **, size_t *, int, nv_alloc_t *);
int nvlist_xunpack(char *, size_t, nvlist_t **, nv_alloc_t *);