map_alloc
data = map_alloc(OVERRUN, NULL, data_size, &data_map);
buf = map_alloc(UNDERRUN, NULL, buf_sz, &buf_map);
buf2 = map_alloc(OVERRUN, buf, sz, &buf2_map);
data = map_alloc(OVERRUN, NULL, data_size, &data_map);
buf = map_alloc(OVERRUN, bytes, sz, &buf_map);
void * map_alloc(enum map_type, const void *, size_t, struct map_page **);
buf = map_alloc(OVERRUN, td[i].data, td[i].len, &page);
buf = map_alloc(OVERRUN, td[i].data, td[i].len, &page);
buf = map_alloc(OVERRUN, td[i].data, td[i].len, &page);