Merge branch 'develop' into develop

mythril/laser/ethereum/instructions.py

@@ -131,7 +131,7 @@ def __init__(self, op_code: str, dynamic_loader: DynLoader):
     def evaluate(self, global_state: GlobalState, post=False) -> List[GlobalState]:
         """ Performs the mutation for this instruction """
         # Generalize some ops
-        # logging.debug("Evaluating {}".format(self.op_code))
+        logging.debug("Evaluating {}".format(self.op_code))
         op = self.op_code.lower()
         if self.op_code.startswith("PUSH"):
             op = "push"
@@ -773,6 +773,14 @@ def extcodecopy_(self, global_state: GlobalState) -> List[GlobalState]:
 
         return [global_state]
 
+    @StateTransition()
+    def returndatacopy_(self, global_state: GlobalState) -> List[GlobalState]:
+        # FIXME: not implemented
+        state = global_state.mstate
+        start, s2, size = state.stack.pop(), state.stack.pop(), state.stack.pop()
+
+        return [global_state]
+
     @StateTransition()
     def returndatasize_(self, global_state: GlobalState) -> List[GlobalState]:
         global_state.mstate.stack.append(global_state.new_bitvec("returndatasize", 256))

mythril/laser/ethereum/state/calldata.py

@@ -108,18 +108,17 @@ def __init__(self, tx_id: int):
         :param tx_id: Id of the transaction that the calldata is for.
         """
         self._reads = []
-        self._size = BitVec("calldatasize", 256)
+        self._size = BitVec(str(tx_id) + "_calldatasize", 256)
         super().__init__(tx_id)
 
     def _load(self, item: Union[int, ExprRef], clean=False) -> Any:
         x = BitVecVal(item, 256) if isinstance(item, int) else item
 
         symbolic_base_value = If(
-            x > self._size,
+            x >= self._size,
             BitVecVal(0, 8),
             BitVec("{}_calldata_{}".format(self.tx_id, str(item)), 8),
         )
-
         return_value = symbolic_base_value
         for r_index, r_value in self._reads:
             return_value = If(r_index == item, r_value, return_value)