fix(specs): backport check_gas before state access boundaries from Amsterdam

Author: fselmo

src/ethereum/forks/arrow_glacier/vm/gas.py

@@ -194,6 +194,23 @@ class MessageCallGas:
     sub_call: Uint
 
 
+def check_gas(evm: Evm, amount: Uint) -> None:
+    """
+    Checks if `amount` gas is available without charging it.
+    Raises OutOfGasError if insufficient gas.
+
+    Parameters
+    ----------
+    evm :
+        The current EVM.
+    amount :
+        The amount of gas to check.
+
+    """
+    if evm.gas_left < amount:
+        raise OutOfGasError
+
+
 def charge_gas(evm: Evm, amount: Uint) -> None:
     """
     Subtracts `amount` from `evm.gas_left`.

src/ethereum/forks/arrow_glacier/vm/instructions/storage.py

@@ -15,10 +15,11 @@
 
 from ...state_tracker import get_storage, get_storage_original, set_storage
 from .. import Evm
-from ..exceptions import OutOfGasError, WriteInStaticContext
+from ..exceptions import WriteInStaticContext
 from ..gas import (
     GasCosts,
     charge_gas,
+    check_gas,
 )
 from ..stack import pop, push
 
@@ -64,11 +65,15 @@ def sstore(evm: Evm) -> None:
         The current EVM frame.
 
     """
+    if evm.message.is_static:
+        raise WriteInStaticContext
+
     # STACK
     key = pop(evm.stack).to_be_bytes32()
     new_value = pop(evm.stack)
-    if evm.gas_left <= GasCosts.CALL_STIPEND:
-        raise OutOfGasError
+
+    # check we have at least the stipend gas
+    check_gas(evm, GasCosts.CALL_STIPEND + Uint(1))
 
     tx_state = evm.message.tx_env.state
     original_value = get_storage_original(
@@ -118,8 +123,6 @@ def sstore(evm: Evm) -> None:
                 )
 
     charge_gas(evm, gas_cost)
-    if evm.message.is_static:
-        raise WriteInStaticContext
     set_storage(tx_state, evm.message.current_target, key, new_value)
 
     # PROGRAM COUNTER

src/ethereum/forks/arrow_glacier/vm/instructions/system.py

@@ -44,6 +44,7 @@
     calculate_gas_extend_memory,
     calculate_message_call_gas,
     charge_gas,
+    check_gas,
     max_message_call_gas,
 )
 from ..memory import memory_read_bytes, memory_write
@@ -64,14 +65,15 @@ def generic_create(
     # if it's not moved inside this method
     from ...vm.interpreter import STACK_DEPTH_LIMIT, process_create_message
 
+    if evm.message.is_static:
+        raise WriteInStaticContext
+
     call_data = memory_read_bytes(
         evm.memory, memory_start_position, memory_size
     )
 
     create_message_gas = max_message_call_gas(Uint(evm.gas_left))
     evm.gas_left -= create_message_gas
-    if evm.message.is_static:
-        raise WriteInStaticContext
     evm.return_data = b""
 
     sender_address = evm.message.current_target
@@ -333,6 +335,9 @@ def call(evm: Evm) -> None:
     memory_output_start_position = pop(evm.stack)
     memory_output_size = pop(evm.stack)
 
+    if evm.message.is_static and value != U256(0):
+        raise WriteInStaticContext
+
     # GAS
     extend_memory = calculate_gas_extend_memory(
         evm.memory,
@@ -342,32 +347,45 @@ def call(evm: Evm) -> None:
         ],
     )
 
-    if to in evm.accessed_addresses:
-        access_gas_cost = GasCosts.WARM_ACCESS
+    is_cold_access = to not in evm.accessed_addresses
+    if is_cold_access:
+        access_gas_cost = GasCosts.COLD_ACCOUNT_ACCESS
     else:
+        access_gas_cost = GasCosts.WARM_ACCESS
+
+    transfer_gas_cost = Uint(0) if value == 0 else GasCosts.CALL_VALUE
+
+    # check static gas before state access
+    check_gas(
+        evm,
+        access_gas_cost + transfer_gas_cost + extend_memory.cost,
+    )
+
+    # STATE ACCESS
+    tx_state = evm.message.tx_env.state
+    if is_cold_access:
         evm.accessed_addresses.add(to)
-        access_gas_cost = GasCosts.COLD_ACCOUNT_ACCESS
 
     code_address = to
 
     create_gas_cost = GasCosts.NEW_ACCOUNT
-    if value == 0 or is_account_alive(evm.message.tx_env.state, to):
+    if value == 0 or is_account_alive(tx_state, to):
         create_gas_cost = Uint(0)
-    transfer_gas_cost = Uint(0) if value == 0 else GasCosts.CALL_VALUE
+
+    extra_gas = access_gas_cost + transfer_gas_cost + create_gas_cost
+
     message_call_gas = calculate_message_call_gas(
         value,
         gas,
         Uint(evm.gas_left),
         extend_memory.cost,
-        access_gas_cost + create_gas_cost + transfer_gas_cost,
+        extra_gas,
     )
     charge_gas(evm, message_call_gas.cost + extend_memory.cost)
-    if evm.message.is_static and value != U256(0):
-        raise WriteInStaticContext
+
+    # OPERATION
     evm.memory += b"\x00" * extend_memory.expand_by
-    sender_balance = get_account(
-        evm.message.tx_env.state, evm.message.current_target
-    ).balance
+    sender_balance = get_account(tx_state, evm.message.current_target).balance
     if sender_balance < value:
         push(evm.stack, U256(0))
         evm.return_data = b""
@@ -422,13 +440,25 @@ def callcode(evm: Evm) -> None:
         ],
     )
 
-    if code_address in evm.accessed_addresses:
-        access_gas_cost = GasCosts.WARM_ACCESS
-    else:
-        evm.accessed_addresses.add(code_address)
+    is_cold_access = code_address not in evm.accessed_addresses
+    if is_cold_access:
         access_gas_cost = GasCosts.COLD_ACCOUNT_ACCESS
+    else:
+        access_gas_cost = GasCosts.WARM_ACCESS
 
     transfer_gas_cost = Uint(0) if value == 0 else GasCosts.CALL_VALUE
+
+    # check static gas before state access
+    check_gas(
+        evm,
+        access_gas_cost + extend_memory.cost + transfer_gas_cost,
+    )
+
+    # STATE ACCESS
+    tx_state = evm.message.tx_env.state
+    if is_cold_access:
+        evm.accessed_addresses.add(code_address)
+
     message_call_gas = calculate_message_call_gas(
         value,
         gas,
@@ -440,9 +470,7 @@ def callcode(evm: Evm) -> None:
 
     # OPERATION
     evm.memory += b"\x00" * extend_memory.expand_by
-    sender_balance = get_account(
-        evm.message.tx_env.state, evm.message.current_target
-    ).balance
+    sender_balance = get_account(tx_state, evm.message.current_target).balance
     if sender_balance < value:
         push(evm.stack, U256(0))
         evm.return_data = b""
@@ -477,52 +505,55 @@ def selfdestruct(evm: Evm) -> None:
         The current EVM frame.
 
     """
+    if evm.message.is_static:
+        raise WriteInStaticContext
+
     # STACK
     beneficiary = to_address_masked(pop(evm.stack))
 
     # GAS
     gas_cost = GasCosts.OPCODE_SELFDESTRUCT_BASE
-    if beneficiary not in evm.accessed_addresses:
-        evm.accessed_addresses.add(beneficiary)
+
+    is_cold_access = beneficiary not in evm.accessed_addresses
+    if is_cold_access:
         gas_cost += GasCosts.COLD_ACCOUNT_ACCESS
 
+    # check access gas cost before state access
+    check_gas(evm, gas_cost)
+
+    # STATE ACCESS
+    tx_state = evm.message.tx_env.state
+    if is_cold_access:
+        evm.accessed_addresses.add(beneficiary)
+
     if (
-        not is_account_alive(evm.message.tx_env.state, beneficiary)
-        and get_account(
-            evm.message.tx_env.state, evm.message.current_target
-        ).balance
-        != 0
+        not is_account_alive(tx_state, beneficiary)
+        and get_account(tx_state, evm.message.current_target).balance != 0
     ):
         gas_cost += GasCosts.OPCODE_SELFDESTRUCT_NEW_ACCOUNT
 
     charge_gas(evm, gas_cost)
-    if evm.message.is_static:
-        raise WriteInStaticContext
 
     originator = evm.message.current_target
-    beneficiary_balance = get_account(
-        evm.message.tx_env.state, beneficiary
-    ).balance
-    originator_balance = get_account(
-        evm.message.tx_env.state, originator
-    ).balance
+    beneficiary_balance = get_account(tx_state, beneficiary).balance
+    originator_balance = get_account(tx_state, originator).balance
 
     # First Transfer to beneficiary
     set_account_balance(
-        evm.message.tx_env.state,
+        tx_state,
         beneficiary,
         beneficiary_balance + originator_balance,
     )
     # Next, Zero the balance of the address being deleted (must come after
     # sending to beneficiary in case the contract named itself as the
     # beneficiary).
-    set_account_balance(evm.message.tx_env.state, originator, U256(0))
+    set_account_balance(tx_state, originator, U256(0))
 
     # register account for deletion
     evm.accounts_to_delete.add(originator)
 
     # mark beneficiary as touched
-    if account_exists_and_is_empty(evm.message.tx_env.state, beneficiary):
+    if account_exists_and_is_empty(tx_state, beneficiary):
         evm.touched_accounts.add(beneficiary)
 
     # HALT the execution
@@ -559,11 +590,18 @@ def delegatecall(evm: Evm) -> None:
         ],
     )
 
-    if code_address in evm.accessed_addresses:
-        access_gas_cost = GasCosts.WARM_ACCESS
+    is_cold_access = code_address not in evm.accessed_addresses
+    if is_cold_access:
+        access_gas_cost = GasCosts.COLD_ACCOUNT_ACCESS
     else:
+        access_gas_cost = GasCosts.WARM_ACCESS
+
+    # check static gas before state access
+    check_gas(evm, access_gas_cost + extend_memory.cost)
+
+    # STATE ACCESS
+    if is_cold_access:
         evm.accessed_addresses.add(code_address)
-        access_gas_cost = GasCosts.COLD_ACCOUNT_ACCESS
 
     message_call_gas = calculate_message_call_gas(
         U256(0),
@@ -622,11 +660,18 @@ def staticcall(evm: Evm) -> None:
         ],
     )
 
-    if to in evm.accessed_addresses:
-        access_gas_cost = GasCosts.WARM_ACCESS
+    is_cold_access = to not in evm.accessed_addresses
+    if is_cold_access:
+        access_gas_cost = GasCosts.COLD_ACCOUNT_ACCESS
     else:
+        access_gas_cost = GasCosts.WARM_ACCESS
+
+    # check static gas before state access
+    check_gas(evm, access_gas_cost + extend_memory.cost)
+
+    # STATE ACCESS
+    if is_cold_access:
         evm.accessed_addresses.add(to)
-        access_gas_cost = GasCosts.COLD_ACCOUNT_ACCESS
 
     code_address = to
 

src/ethereum/forks/berlin/vm/gas.py

@@ -194,6 +194,23 @@ class MessageCallGas:
     sub_call: Uint
 
 
+def check_gas(evm: Evm, amount: Uint) -> None:
+    """
+    Checks if `amount` gas is available without charging it.
+    Raises OutOfGasError if insufficient gas.
+
+    Parameters
+    ----------
+    evm :
+        The current EVM.
+    amount :
+        The amount of gas to check.
+
+    """
+    if evm.gas_left < amount:
+        raise OutOfGasError
+
+
 def charge_gas(evm: Evm, amount: Uint) -> None:
     """
     Subtracts `amount` from `evm.gas_left`.

src/ethereum/forks/berlin/vm/instructions/storage.py

@@ -15,10 +15,11 @@
 
 from ...state_tracker import get_storage, get_storage_original, set_storage
 from .. import Evm
-from ..exceptions import OutOfGasError, WriteInStaticContext
+from ..exceptions import WriteInStaticContext
 from ..gas import (
     GasCosts,
     charge_gas,
+    check_gas,
 )
 from ..stack import pop, push
 
@@ -64,11 +65,15 @@ def sstore(evm: Evm) -> None:
         The current EVM frame.
 
     """
+    if evm.message.is_static:
+        raise WriteInStaticContext
+
     # STACK
     key = pop(evm.stack).to_be_bytes32()
     new_value = pop(evm.stack)
-    if evm.gas_left <= GasCosts.CALL_STIPEND:
-        raise OutOfGasError
+
+    # check we have at least the stipend gas
+    check_gas(evm, GasCosts.CALL_STIPEND + Uint(1))
 
     tx_state = evm.message.tx_env.state
     original_value = get_storage_original(
@@ -118,8 +123,6 @@ def sstore(evm: Evm) -> None:
                 )
 
     charge_gas(evm, gas_cost)
-    if evm.message.is_static:
-        raise WriteInStaticContext
     set_storage(tx_state, evm.message.current_target, key, new_value)
 
     # PROGRAM COUNTER