Remove buffer gas added in the gas consumption of EVM.dryRun

fvm/evm/emulator/emulator.go

@@ -258,8 +258,6 @@ func (bl *BlockView) DryRunTransaction(
 	tx *gethTypes.Transaction,
 	from gethCommon.Address,
 ) (*types.Result, error) {
-	var txResult *types.Result
-
 	// create a new procedure
 	proc, err := bl.newProcedure()
 	if err != nil {
@@ -283,42 +281,8 @@ func (bl *BlockView) DryRunTransaction(
 	// we need to skip nonce check for dry run
 	msg.SkipAccountChecks = true
 
-	// call tracer
-	if proc.evm.Config.Tracer != nil && proc.evm.Config.Tracer.OnTxStart != nil {
-		proc.evm.Config.Tracer.OnTxStart(proc.evm.GetVMContext(), tx, msg.From)
-	}
-
-	// return without committing the state
-	txResult, err = proc.run(msg, tx.Hash(), tx.Type())
-	if txResult.Successful() {
-		// As mentioned in https://github.com/ethereum/EIPs/blob/master/EIPS/eip-150.md#specification
-		// Define "all but one 64th" of N as N - floor(N / 64).
-		// If a call asks for more gas than the maximum allowed amount
-		// (i.e. the total amount of gas remaining in the parent after subtracting
-		// the gas cost of the call and memory expansion), do not return an OOG error;
-		// instead, if a call asks for more gas than all but one 64th of the maximum
-		// allowed amount, call with all but one 64th of the maximum allowed amount of
-		// gas (this is equivalent to a version of EIP-901 plus EIP-1142).
-		// CREATE only provides all but one 64th of the parent gas to the child call.
-		txResult.GasConsumed = AddOne64th(txResult.GasConsumed)
-
-		// Adding `gethParams.SstoreSentryGasEIP2200` is needed for this condition:
-		// https://github.com/onflow/go-ethereum/blob/master/core/vm/operations_acl.go#L29-L32
-		txResult.GasConsumed += gethParams.SstoreSentryGasEIP2200
-
-		// Take into account any gas refunds, which are calculated only after
-		// transaction execution.
-		txResult.GasConsumed += txResult.GasRefund
-	}
-
-	// call tracer on tx end
-	if proc.evm.Config.Tracer != nil &&
-		proc.evm.Config.Tracer.OnTxEnd != nil &&
-		txResult != nil {
-		proc.evm.Config.Tracer.OnTxEnd(txResult.Receipt(), txResult.ValidationError)
-	}
-
-	return txResult, err
+	// run and return without committing the state changes
+	return proc.run(msg, tx.Hash(), tx.Type())
 }
 
 func (bl *BlockView) newProcedure() (*procedure, error) {
@@ -707,11 +671,6 @@ func (proc *procedure) run(
 	return &res, nil
 }
 
-func AddOne64th(n uint64) uint64 {
-	// NOTE: Go's integer division floors, but that is desirable here
-	return n + (n / 64)
-}
-
 func convertAndCheckValue(input *big.Int) (isValid bool, converted *uint256.Int) {
 	// check for negative input
 	if input.Sign() < 0 {

fvm/evm/evm_test.go

@@ -23,7 +23,6 @@ import (
 	"github.com/onflow/flow-go/fvm/environment"
 	envMock "github.com/onflow/flow-go/fvm/environment/mock"
 	"github.com/onflow/flow-go/fvm/evm"
-	"github.com/onflow/flow-go/fvm/evm/emulator"
 	"github.com/onflow/flow-go/fvm/evm/events"
 	"github.com/onflow/flow-go/fvm/evm/impl"
 	"github.com/onflow/flow-go/fvm/evm/stdlib"
@@ -1513,11 +1512,13 @@ func TestDryRun(t *testing.T) {
 					evmAddress,
 				))
 
+				// Use the gas estimation from Evm.dryRun with some buffer
+				gasLimit := dryRunResult.GasConsumed + gethParams.SstoreSentryGasEIP2200
 				innerTxBytes := testAccount.PrepareSignAndEncodeTx(t,
 					testContract.DeployedAt.ToCommon(),
 					data,
 					big.NewInt(0),
-					dryRunResult.GasConsumed, // use the gas estimation from Evm.dryRun
+					gasLimit,
 					big.NewInt(0),
 				)
 
@@ -1545,15 +1546,7 @@ func TestDryRun(t *testing.T) {
 				require.NoError(t, err)
 				require.Equal(t, types.StatusSuccessful, res.Status)
 				require.Equal(t, types.ErrCodeNoError, res.ErrorCode)
-				// Make sure that gas consumed from `EVM.dryRun` is bigger
-				// than the actual gas consumption of the equivalent
-				// `EVM.run`.
-				totalGas := emulator.AddOne64th(res.GasConsumed) + gethParams.SstoreSentryGasEIP2200
-				require.Equal(
-					t,
-					totalGas,
-					dryRunResult.GasConsumed,
-				)
+				require.Equal(t, res.GasConsumed, dryRunResult.GasConsumed)
 			})
 	})
 
@@ -1679,15 +1672,7 @@ func TestDryRun(t *testing.T) {
 				require.NoError(t, err)
 				require.Equal(t, types.StatusSuccessful, res.Status)
 				require.Equal(t, types.ErrCodeNoError, res.ErrorCode)
-				// Make sure that gas consumed from `EVM.dryRun` is bigger
-				// than the actual gas consumption of the equivalent
-				// `EVM.run`.
-				totalGas := emulator.AddOne64th(res.GasConsumed) + gethParams.SstoreSentryGasEIP2200
-				require.Equal(
-					t,
-					totalGas,
-					dryRunResult.GasConsumed,
-				)
+				require.Equal(t, res.GasConsumed, dryRunResult.GasConsumed)
 			})
 	})
 
@@ -1779,11 +1764,13 @@ func TestDryRun(t *testing.T) {
 					evmAddress,
 				))
 
+				// use the gas estimation from Evm.dryRun with the necessary buffer gas
+				gasLimit := dryRunResult.GasConsumed + gethParams.SstoreSentryGasEIP2200 + gethParams.SstoreClearsScheduleRefundEIP3529
 				innerTxBytes = testAccount.PrepareSignAndEncodeTx(t,
 					testContract.DeployedAt.ToCommon(),
 					data,
 					big.NewInt(0),
-					dryRunResult.GasConsumed, // use the gas estimation from Evm.dryRun
+					gasLimit,
 					big.NewInt(0),
 				)
 
@@ -1809,17 +1796,9 @@ func TestDryRun(t *testing.T) {
 
 				res, err := impl.ResultSummaryFromEVMResultValue(output.Value)
 				require.NoError(t, err)
-				//require.Equal(t, types.StatusSuccessful, res.Status)
+				require.Equal(t, types.StatusSuccessful, res.Status)
 				require.Equal(t, types.ErrCodeNoError, res.ErrorCode)
-				// Make sure that gas consumed from `EVM.dryRun` is bigger
-				// than the actual gas consumption of the equivalent
-				// `EVM.run`.
-				totalGas := emulator.AddOne64th(res.GasConsumed) + gethParams.SstoreSentryGasEIP2200 + gethParams.SstoreClearsScheduleRefundEIP3529
-				require.Equal(
-					t,
-					totalGas,
-					dryRunResult.GasConsumed,
-				)
+				require.Equal(t, res.GasConsumed, dryRunResult.GasConsumed)
 			})
 	})