Ban Dead Addresses (#143)

* add check and test

* uint->uint256

packages/contracts/contracts/optimistic-ethereum/OVM/execution/OVM_ExecutionManager.sol

@@ -894,7 +894,7 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
      * Calls the deployed contract associated with a given address.
      * @param _nextMessageContext Message context to be used for the call.
      * @param _gasLimit Amount of gas to be passed into this call.
-     * @param _contract Address used to resolve the deployed contract.
+     * @param _contract OVM address to be called.
      * @param _calldata Data to send along with the call.
      * @return _success Whether or not the call returned (rather than reverted).
      * @return _returndata Data returned by the call.
@@ -911,6 +911,14 @@ contract OVM_ExecutionManager is iOVM_ExecutionManager, Lib_AddressResolver {
             bytes memory _returndata
         )
     {
+        // We reserve addresses of the form 0xdeaddeaddead...NNNN for the container contracts in L2 geth.
+        // So, we block calls to these addresses since they are not safe to run as an OVM contract itself.
+        if (
+            (uint256(_contract) & uint256(0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff0000)) 
+            == uint256(0xDeadDeAddeAddEAddeadDEaDDEAdDeaDDeAD0000)
+        ) {
+            return (true, hex'');
+        }
 
         // Both 0x0000... and the EVM precompiles have the same address on L1 and L2 --> no trie lookup needed.
         address codeContractAddress =

packages/contracts/test/contracts/OVM/execution/OVM_ExecutionManager/ovmCALL.spec.ts

@@ -11,6 +11,8 @@ import {
 const DUMMY_REVERT_DATA =
   '0xdeadbeef1e5420deadbeef1e5420deadbeef1e5420deadbeef1e5420deadbeef1e5420'
 
+const DEAD_ADDRESS = '0xdeaddeaddeaddeaddeaddeaddeaddeaddead1234'
+
 const test_ovmCALL: TestDefinition = {
   name: 'Basic tests for ovmCALL',
   preState: {
@@ -241,6 +243,24 @@ const test_ovmCALL: TestDefinition = {
         },
       ],
     },
+    {
+      name: 'ovmCALL(0xdeaddeaddead...) returns (true, 0x)',
+      steps: [
+        {
+          functionName: 'ovmCALL',
+          functionParams: {
+            gasLimit: OVM_TX_GAS_LIMIT,
+            target: DEAD_ADDRESS,
+            subSteps: []
+          },
+          expectedReturnStatus: true,
+          expectedReturnValue: {
+            ovmSuccess: true,
+            returnData: '0x'
+          },
+        },
+      ],
+    },
   ],
 }