mdb_callb_t
mdb_callb_t *cb, *next;
mdb_callb_t *
mdb_callb_t *new = mdb_zalloc(sizeof (mdb_callb_t), UM_SLEEP);
mdb_callb_remove(mdb_callb_t *cb)
mdb_callb_t *next = mdb_list_next(cb);
mdb_free(cb, sizeof (mdb_callb_t));
mdb_callb_t *cb;
extern mdb_callb_t *mdb_callb_add(mdb_module_t *, int, mdb_callb_f, void *);
extern void mdb_callb_remove(mdb_callb_t *);