Add BASEFEE opcode (#1513)

* Add BASEFEE opcode

* Add test

mythril/laser/ethereum/instruction_data.py

@@ -175,6 +175,7 @@ OPCODES = {
     "CALL": {GAS: (700, 700 + 9000 + 25000), STACK: (7, 1)},
     "CALLCODE": {GAS: (700, 700 + 9000 + 25000), STACK: (7, 1)},
     "RETURN": {GAS: (0, 0), STACK: (2, 0)},
+    "BASEFEE": {GAS: (2, 2), STACK: Z_OPERATOR_TUPLE},
     "DELEGATECALL": {GAS: (700, 700 + 9000 + 25000), STACK: (6, 1)},
     "STATICCALL": {GAS: (700, 700 + 9000 + 25000), STACK: (6, 1)},
     "REVERT": {GAS: (0, 0), STACK: (2, 0)},

mythril/laser/ethereum/instructions.py

@@ -1041,6 +1041,16 @@ class Instruction:
         global_state.mstate.stack.append(global_state.environment.gasprice)
         return [global_state]
 
+    @StateTransition()
+    def basefee_(self, global_state: GlobalState) -> List[GlobalState]:
+        """
+
+        :param global_state:
+        :return:
+        """
+        global_state.mstate.stack.append(global_state.environment.basefee)
+        return [global_state]
+
     @StateTransition()
     def codecopy_(self, global_state: GlobalState) -> List[GlobalState]:
         """

mythril/laser/ethereum/state/environment.py

@@ -21,6 +21,7 @@ class Environment:
         gasprice: ExprRef,
         callvalue: ExprRef,
         origin: ExprRef,
+        basefee: ExprRef,
         code=None,
         static=False,
     ) -> None:
@@ -55,6 +56,7 @@ class Environment:
         self.origin = origin
         self.callvalue = callvalue
         self.static = static
+        self.basefee = basefee
 
     def __str__(self) -> str:
         """

mythril/laser/ethereum/transaction/transaction_models.py

@@ -69,6 +69,7 @@ class BaseTransaction:
         call_value=None,
         init_call_data=True,
         static=False,
+        base_fee=None,
     ) -> None:
         assert isinstance(world_state, WorldState)
         self.world_state = world_state
@@ -77,14 +78,21 @@ class BaseTransaction:
         self.gas_price = (
             gas_price
             if gas_price is not None
-            else symbol_factory.BitVecSym("gasprice{}".format(identifier), 256)
+            else symbol_factory.BitVecSym(f"gasprice{identifier}", 256)
         )
+
+        self.base_fee = (
+            base_fee
+            if base_fee is not None
+            else symbol_factory.BitVecSym(f"basefee{identifier}", 256)
+        )
+
         self.gas_limit = gas_limit
 
         self.origin = (
             origin
             if origin is not None
-            else symbol_factory.BitVecSym("origin{}".format(identifier), 256)
+            else symbol_factory.BitVecSym(f"origin{identifier}", 256)
         )
         self.code = code
 
@@ -102,7 +110,7 @@ class BaseTransaction:
         self.call_value = (
             call_value
             if call_value is not None
-            else symbol_factory.BitVecSym("callvalue{}".format(identifier), 256)
+            else symbol_factory.BitVecSym(f"callvalue{identifier}", 256)
         )
         self.static = static
         self.return_data = None  # type: str
@@ -161,6 +169,7 @@ class MessageCallTransaction(BaseTransaction):
             self.gas_price,
             self.call_value,
             self.origin,
+            self.base_fee,
             code=self.code or self.callee_account.code,
             static=self.static,
         )
@@ -196,6 +205,7 @@ class ContractCreationTransaction(BaseTransaction):
         call_value=None,
         contract_name=None,
         contract_address=None,
+        base_fee=None,
     ) -> None:
         self.prev_world_state = deepcopy(world_state)
         contract_address = (
@@ -219,18 +229,20 @@ class ContractCreationTransaction(BaseTransaction):
             code=code,
             call_value=call_value,
             init_call_data=True,
+            base_fee=base_fee,
         )
 
     def initial_global_state(self) -> GlobalState:
         """Initialize the execution environment."""
         environment = Environment(
-            self.callee_account,
-            self.caller,
-            self.call_data,
-            self.gas_price,
-            self.call_value,
-            self.origin,
-            self.code,
+            active_account=self.callee_account,
+            sender=self.caller,
+            calldata=self.call_data,
+            gasprice=self.gas_price,
+            callvalue=self.call_value,
+            origin=self.origin,
+            basefee=self.base_fee,
+            code=self.code,
         )
         return super().initial_global_state_from_environment(
             environment, active_function="constructor"

mythril/support/opcodes.py

@@ -53,6 +53,7 @@ opcodes = {
     0x45: ("GASLIMIT", 0, 1, 2),
     0x46: ("CHAINID", 0, 1, 2),
     0x47: ("SELFBALANCE", 0, 1, 5),
+    0x48: ("BASEFEE", 0, 1, 2),
     0x50: ("POP", 1, 0, 2),
     0x51: ("MLOAD", 1, 1, 3),
     0x52: ("MSTORE", 2, 0, 3),

tests/instructions/berlin_fork_opcodes_test.py

@@ -17,7 +17,7 @@ def get_state():
     world_state = WorldState()
     account = world_state.create_account(balance=10, address=101)
     account.code = Disassembly("0x60045e005c5d")
-    environment = Environment(account, None, None, None, None, None)
+    environment = Environment(account, None, None, None, None, None, None)
     state = GlobalState(world_state, environment, None, MachineState(gas_limit=8000000))
     state.transaction_stack.append(
         (MessageCallTransaction(world_state=WorldState(), gas_limit=8000000), None)

tests/instructions/codecopy_test.py

@@ -13,7 +13,7 @@ def test_codecopy_concrete():
     world_state = WorldState()
     account = world_state.create_account(balance=10, address=101)
     account.code = Disassembly("60606040")
-    environment = Environment(account, None, None, None, None, None)
+    environment = Environment(account, None, None, None, None, None, None)
     og_state = GlobalState(
         world_state, environment, None, MachineState(gas_limit=8000000)
     )

tests/instructions/create2_test.py

@@ -34,7 +34,7 @@ def test_create2():
     world_state = WorldState()
     account = world_state.create_account(balance=10, address=101)
     account.code = Disassembly("60606040")
-    environment = Environment(account, None, None, None, None, None)
+    environment = Environment(account, None, None, None, None, None, None)
     og_state = GlobalState(
         world_state, environment, None, MachineState(gas_limit=8000000)
     )

tests/instructions/create_test.py

@@ -21,7 +21,7 @@ def test_create():
     world_state = WorldState()
     account = world_state.create_account(balance=10, address=101)
     account.code = Disassembly("60606060")
-    environment = Environment(account, None, None, None, None, None)
+    environment = Environment(account, None, None, None, None, None, None)
     og_state = GlobalState(
         world_state, environment, None, MachineState(gas_limit=8000000)
     )

tests/instructions/extcodecopy_test.py

@@ -16,7 +16,7 @@ def test_extcodecopy():
     ext_account = new_world_state.create_account(balance=1000, address=121)
     ext_account.code = Disassembly("6040404040")
 
-    new_environment = Environment(new_account, None, None, None, None, None)
+    new_environment = Environment(new_account, None, None, None, None, None, None)
     state = GlobalState(
         new_world_state, new_environment, None, MachineState(gas_limit=8000000)
     )
@@ -38,7 +38,7 @@ def test_extcodecopy_fail():
     new_world_state = WorldState()
     new_account = new_world_state.create_account(balance=10, address=101)
     new_account.code = Disassembly("60616240")
-    new_environment = Environment(new_account, None, None, None, None, None)
+    new_environment = Environment(new_account, None, None, None, None, None, None)
     state = GlobalState(
         new_world_state, new_environment, None, MachineState(gas_limit=8000000)
     )

tests/instructions/extcodehash_test.py

@@ -16,7 +16,7 @@ world_state = WorldState()
 account = world_state.create_account(balance=10, address=101)
 account.code = Disassembly("60606040")
 world_state.create_account(balance=10, address=1000)
-environment = Environment(account, None, None, None, None, None)
+environment = Environment(account, None, None, None, None, None, None)
 og_state = GlobalState(world_state, environment, None, MachineState(gas_limit=8000000))
 og_state.transaction_stack.append(
     (MessageCallTransaction(world_state=WorldState(), gas_limit=8000000), None)

tests/instructions/sar_test.py

@@ -16,7 +16,7 @@ def get_state():
     world_state = WorldState()
     account = world_state.create_account(balance=10, address=101)
     account.code = Disassembly("60606040")
-    environment = Environment(account, None, None, None, None, None)
+    environment = Environment(account, None, None, None, None, None, None)
     state = GlobalState(world_state, environment, None, MachineState(gas_limit=8000000))
     state.transaction_stack.append(
         (MessageCallTransaction(world_state=WorldState(), gas_limit=8000000), None)

tests/instructions/shl_test.py

@@ -15,7 +15,7 @@ def get_state():
     world_state = WorldState()
     account = world_state.create_account(balance=10, address=101)
     account.code = Disassembly("60606040")
-    environment = Environment(account, None, None, None, None, None)
+    environment = Environment(account, None, None, None, None, None, None)
     state = GlobalState(world_state, environment, None, MachineState(gas_limit=8000000))
     state.transaction_stack.append(
         (MessageCallTransaction(world_state=WorldState(), gas_limit=8000000), None)

tests/instructions/shr_test.py

@@ -15,7 +15,7 @@ def get_state():
     world_state = WorldState()
     account = world_state.create_account(balance=10, address=101)
     account.code = Disassembly("60606040")
-    environment = Environment(account, None, None, None, None, None)
+    environment = Environment(account, None, None, None, None, None, None)
     state = GlobalState(world_state, environment, None, MachineState(gas_limit=8000000))
     state.transaction_stack.append(
         (MessageCallTransaction(world_state=WorldState(), gas_limit=8000000), None)

tests/instructions/static_call_test.py

@@ -19,7 +19,7 @@ from mythril.laser.ethereum.evm_exceptions import WriteProtection
 def get_global_state():
     active_account = Account("0x0", code=Disassembly("60606040"))
     environment = Environment(
-        active_account, None, SymbolicCalldata("2"), None, None, None
+        active_account, None, SymbolicCalldata("2"), None, None, None, None
     )
     world_state = WorldState()
     world_state.put_account(active_account)

tests/instructions/test_basefee.py

@@ -0,0 +1,39 @@
+from mythril.disassembler.disassembly import Disassembly
+from mythril.laser.ethereum.state.environment import Environment
+from mythril.laser.ethereum.state.machine_state import MachineState
+from mythril.laser.ethereum.state.global_state import GlobalState
+from mythril.laser.ethereum.state.world_state import WorldState
+from mythril.laser.ethereum.instructions import Instruction
+from mythril.laser.ethereum.transaction.transaction_models import MessageCallTransaction
+from mythril.laser.smt import symbol_factory
+
+
+def test_basefee():
+    # Arrange
+    world_state = WorldState()
+    account = world_state.create_account(balance=10, address=101)
+    account.code = Disassembly("60606040")
+    environment = Environment(
+        account,
+        None,
+        None,
+        None,
+        None,
+        None,
+        basefee=symbol_factory.BitVecSym("gasfee", 256),
+    )
+    og_state = GlobalState(
+        world_state, environment, None, MachineState(gas_limit=8000000)
+    )
+    og_state.transaction_stack.append(
+        (MessageCallTransaction(world_state=WorldState(), gas_limit=8000000), None)
+    )
+
+    og_state.mstate.stack = []
+    instruction = Instruction("basefee", dynamic_loader=None)
+
+    # Act
+    new_state = instruction.evaluate(og_state)[0]
+
+    # Assert
+    assert new_state.mstate.stack == [symbol_factory.BitVecSym("gasfee", 256)]