lookup_symbol_name
if (wchan && !lookup_symbol_name(wchan, symname)) {
int lookup_symbol_name(unsigned long addr, char *symname);
ret = lookup_symbol_name(addr, namebuf);
if (!lookup_symbol_name(addr, symname)) {
if (lookup_symbol_name(addr, symbuf))
if (!lookup_symbol_name(addr, symname)) {
if (lookup_symbol_name(func, name))