3 files changed, 19 insertions, 2 deletions
diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index 007e5e3..3d388d6 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -220,7 +220,7 @@ func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (
 			// for a call operation is the value. Transferring value from one
 			// account to the others means the state is modified and should also
 			// return with an error.
-			if operation.writes || (op == CALL && stack.Back(2).Sign() != 0) {
+			if operation.writes || ((op == CALL || op == CALLEX) && stack.Back(2).Sign() != 0) {
 				return nil, errWriteProtection
 			}
 		}
diff --git a/core/vm/jump_table.go b/core/vm/jump_table.go
index 359b753..737dd14 100644
--- a/core/vm/jump_table.go
+++ b/core/vm/jump_table.go
@@ -183,6 +183,7 @@ func newTangerineWhistleInstructionSet() JumpTable {
 	instructionSet[SLOAD].constantGas = params.SloadGasEIP150
 	instructionSet[EXTCODECOPY].constantGas = params.ExtcodeCopyBaseEIP150
 	instructionSet[CALL].constantGas = params.CallGasEIP150
+	instructionSet[CALLEX].constantGas = params.CallGasEIP150
 	instructionSet[CALLCODE].constantGas = params.CallGasEIP150
 	instructionSet[DELEGATECALL].constantGas = params.CallGasEIP150
 	return instructionSet
@@ -1147,7 +1148,7 @@ func newFrontierInstructionSet() JumpTable {
 			dynamicGas:  gasCall,
 			minStack:    minStack(9, 1),
 			maxStack:    maxStack(9, 1),
-			memorySize:  memoryCall,
+			memorySize:  memoryCallExpert,
 			valid:       true,
 			returns:     true,
 		},
diff --git a/core/vm/memory_table.go b/core/vm/memory_table.go
index 4fcb414..047f610 100644
--- a/core/vm/memory_table.go
+++ b/core/vm/memory_table.go
@@ -70,6 +70,22 @@ func memoryCall(stack *Stack) (uint64, bool) {
 	}
 	return y, false
 }
+
+func memoryCallExpert(stack *Stack) (uint64, bool) {
+	x, overflow := calcMemSize64(stack.Back(7), stack.Back(8))
+	if overflow {
+		return 0, true
+	}
+	y, overflow := calcMemSize64(stack.Back(5), stack.Back(6))
+	if overflow {
+		return 0, true
+	}
+	if x > y {
+		return x, false
+	}
+	return y, false
+}
+
 func memoryDelegateCall(stack *Stack) (uint64, bool) {
 	x, overflow := calcMemSize64(stack.Back(4), stack.Back(5))
 	if overflow {