[security] refine _get_program_cache_key (PaddlePaddle#61827)

* security, refine _get_program_cache_key

python/paddle/base/executor.py

@@ -682,15 +682,19 @@ def _get_varname_from_block(block):
     )
 
 
-def _get_program_cache_key(feed, fetch_list):
+def _get_feed_fetch_var_names(feed, fetch_list):
     feed_var_names = []
     if isinstance(feed, dict):
         feed_var_names = list(feed.keys())
     elif isinstance(feed, (list, tuple)):
         for i, each in enumerate(feed):
             feed_var_names += list(each.keys())
     fetch_var_names = list(map(_to_name_str, fetch_list))
-    return str(feed_var_names + fetch_var_names)
+    return feed_var_names + fetch_var_names
+
+
+def _get_program_cache_key(feed, fetch_list):
+    return str(_get_feed_fetch_var_names(feed, fetch_list))
 
 
 def _as_lodtensor(data, place, dtype=None):
@@ -1026,7 +1030,7 @@ def _get_program_and_executor(self, cached_data):
 
         if enable_inplace or enable_addto:
             # inplace should skip feed and fetch var
-            skip_var_names = eval(_get_program_cache_key(feed, fetch_list))
+            skip_var_names = _get_feed_fetch_var_names(feed, fetch_list)
             _apply_inplace_addto_pass(
                 program, enable_inplace, enable_addto, skip_var_names
             )