ssize_t mdb_readsym(void *buf, size_t nbytes, const char *name);
mdb_readsym() is similar to mdb_vread(), except that the virtual address at which reading begins is obtained from the value of the symbol specified by name. If no symbol by that name is found or a read error occurs, -1 is returned; otherwise nbytes is returned for success.
The caller can first look up the symbol separately if it is necessary to distinguish between symbol lookup failure and read failure. The primary executable's symbol table is used for the symbol lookup; if the symbol resides in another symbol table, you must first apply mdb_lookup_by_obj(), then mdb_vread().