Address POV Underestimations (#244)

Author: TarekkMA

frame/evm/src/lib.rs

@@ -118,6 +118,7 @@ pub use self::{
 #[frame_support::pallet]
 pub mod pallet {
 	use super::*;
+	use cumulus_primitives_storage_weight_reclaim::get_proof_size;
 	use frame_support::pallet_prelude::*;
 	use frame_system::pallet_prelude::*;
 
@@ -684,6 +685,35 @@ pub mod pallet {
 	#[pallet::storage]
 	pub type AccountStorages<T: Config> =
 		StorageDoubleMap<_, Blake2_128Concat, H160, Blake2_128Concat, H256, H256, ValueQuery>;
+
+	#[pallet::hooks]
+	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
+		fn on_initialize(_: BlockNumberFor<T>) -> Weight {
+			let mut total_weight = Weight::zero();
+
+			// Do dummy read to populate the pov with the intermediates nodes,
+			// only when proof size recording is enabled.
+			if let Some(pov_before) = get_proof_size() {
+				const ZERO_ACCOUNT: H160 = H160::zero();
+
+				// just a dummy read to populate the pov with the intermediates nodes
+				let _ = AccountCodesMetadata::<T>::get(ZERO_ACCOUNT.clone());
+				let (_, min_gas_weight) = T::FeeCalculator::min_gas_price();
+				let (_, account_basic_weight) = Pallet::<T>::account_basic(&ZERO_ACCOUNT);
+
+				let pov = get_proof_size().unwrap_or_default() - pov_before;
+
+				total_weight = total_weight
+					.saturating_add(Weight::from_parts(0, pov))
+					.saturating_add(T::DbWeight::get().reads(1))
+					.saturating_add(account_basic_weight)
+					.saturating_add(min_gas_weight);
+
+			}
+
+			total_weight
+		}
+	}
 }
 
 /// Utility alias for easy access to the [`AccountProvider::AccountId`] type from a given config.

frame/evm/src/runner/stack.rs

@@ -187,7 +187,7 @@ where
 		R: Default,
 	{
 		// Used to record the external costs in the evm through the StackState implementation
-		let maybe_weight_info =
+		let mut maybe_weight_info =
 			WeightInfo::new_from_weight_limit(weight_limit, proof_size_base_cost).map_err(
 				|_| RunnerError {
 					error: Error::<T>::GasLimitTooLow,
@@ -220,17 +220,22 @@ where
 		//
 		// EIP-3607: https://eips.ethereum.org/EIPS/eip-3607
 		// Do not allow transactions for which `tx.sender` has any code deployed.
-		if is_transactional
-			&& <AccountCodesMetadata<T>>::get(source)
-				.unwrap_or_default()
-				.size != 0
-		{
+		let account_code_metadata = <AccountCodesMetadata<T>>::get(source);
+		if is_transactional && account_code_metadata.unwrap_or_default().size != 0 {
 			return Err(RunnerError {
 				error: Error::<T>::TransactionMustComeFromEOA,
 				weight,
 			});
 		}
 
+		if let Some(ref mut weight_info) = maybe_weight_info {
+			weight_info
+				.try_record_proof_size_or_fail(ACCOUNT_CODES_METADATA_PROOF_SIZE)
+				.map_err(|_| RunnerError {
+					error: Error::<T>::GasLimitTooLow,
+					weight,
+				})?;
+		}
 		let total_fee_per_gas = if is_transactional {
 			match (max_fee_per_gas, max_priority_fee_per_gas) {
 				// Zero max_fee_per_gas for validated transactional calls exist in XCM -> EVM
@@ -339,6 +344,13 @@ where
 						);
 						estimated_proof_size
 					} else {
+						log::debug!(
+							target: "evm",
+							"Proof size overestimation detected! (estimated: {}, actual: {}, diff: {})",
+							estimated_proof_size,
+							actual_proof_size,
+							estimated_proof_size.saturating_sub(actual_proof_size),
+						);
 						actual_proof_size
 					}
 				} else {

primitives/ethereum/src/lib.rs

@@ -84,6 +84,10 @@ impl TransactionData {
 	pub fn proof_size_base_cost(&self) -> u64 {
 		self.encode()
 			.len()
+			// The real struct [EIP1559Transaction] doesn't have
+			// Option wrapper for gas_price, max_fee_per_gas and max_priority_fee_per_gas
+			// so we need to remove the size of the Option wrapper
+			.saturating_sub(3)
 			// signature
 			.saturating_add(65)
 			// pallet index