Allow to have duplicated address for multiple symbol

In certain condition, it is possible to have multiple functions with the
same address on kallsyms. We have treated that kind of the case as
error, but relax it and generate log in verbose mode instead.

Signed-off-by: Yutaro Hayakawa <yhayakawa3720@gmail.com>

src/symsdb.c

@@ -80,7 +80,7 @@ static int
 put_addr2sym(struct ipft_symsdb *sdb, uint64_t addr, char *symname,
              char *modname)
 {
-  int missing;
+  int error;
   khint_t iter;
   struct ipft_sym *sym;
   khash_t(addr2sym) * db;
@@ -102,9 +102,13 @@ put_addr2sym(struct ipft_symsdb *sdb, uint64_t addr, char *symname,
 
   db = ((struct ipft_symsdb *)sdb)->addr2symname;
 
-  iter = kh_put(addr2sym, db, addr, &missing);
-  if (!missing) {
+  iter = kh_put(addr2sym, db, addr, &error);
+  if (error == -1) {
     return -1;
+  } else if (error == 0) {
+    VERBOSE("Duplicated address found %p for symbol %s at module %s\n",
+        (void *)addr, symname, modname);
+    return 0;
   }
 
   kh_value(db, iter) = sym;