core, all: split vm.Context into BlockContext and TxContext (#21672)

* all: core: split vm.Config into BlockConfig and TxConfig

* core: core/vm: reset EVM between tx in block instead of creating new

* core/vm: added docs

accounts/abi/bind/backends/simulated.go

@@ -542,10 +542,11 @@ func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallM
 	// Execute the call.
 	msg := callMsg{call}
 
-	evmContext := core.NewEVMContext(msg, block.Header(), b.blockchain, nil)
+	txContext := core.NewEVMTxContext(msg)
+	evmContext := core.NewEVMBlockContext(block.Header(), b.blockchain, nil)
 	// Create a new environment which holds all relevant information
 	// about the transaction and calling mechanisms.
-	vmEnv := vm.NewEVM(evmContext, stateDB, b.config, vm.Config{})
+	vmEnv := vm.NewEVM(evmContext, txContext, stateDB, b.config, vm.Config{})
 	gasPool := new(core.GasPool).AddGas(math.MaxUint64)
 
 	return core.NewStateTransition(vmEnv, msg, gasPool).TransitionDb()

cmd/evm/internal/t8ntool/execution.go

@@ -110,7 +110,7 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 		txIndex     = 0
 	)
 	gaspool.AddGas(pre.Env.GasLimit)
-	vmContext := vm.Context{
+	vmContext := vm.BlockContext{
 		CanTransfer: core.CanTransfer,
 		Transfer:    core.Transfer,
 		Coinbase:    pre.Env.Coinbase,
@@ -119,7 +119,6 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 		Difficulty:  pre.Env.Difficulty,
 		GasLimit:    pre.Env.GasLimit,
 		GetHash:     getHash,
-		// GasPrice and Origin needs to be set per transaction
 	}
 	// If DAO is supported/enabled, we need to handle it here. In geth 'proper', it's
 	// done in StateProcessor.Process(block, ...), right before transactions are applied.
@@ -143,10 +142,9 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 		vmConfig.Tracer = tracer
 		vmConfig.Debug = (tracer != nil)
 		statedb.Prepare(tx.Hash(), blockHash, txIndex)
-		vmContext.GasPrice = msg.GasPrice()
-		vmContext.Origin = msg.From()
+		txContext := core.NewEVMTxContext(msg)
 
-		evm := vm.NewEVM(vmContext, statedb, chainConfig, vmConfig)
+		evm := vm.NewEVM(vmContext, txContext, statedb, chainConfig, vmConfig)
 		if chainConfig.IsYoloV2(vmContext.BlockNumber) {
 			statedb.AddAddressToAccessList(msg.From())
 			if dst := msg.To(); dst != nil {
@@ -185,7 +183,7 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 			receipt.GasUsed = msgResult.UsedGas
 			// if the transaction created a contract, store the creation address in the receipt.
 			if msg.To() == nil {
-				receipt.ContractAddress = crypto.CreateAddress(evm.Context.Origin, tx.Nonce())
+				receipt.ContractAddress = crypto.CreateAddress(evm.TxContext.Origin, tx.Nonce())
 			}
 			// Set the receipt logs and create a bloom for filtering
 			receipt.Logs = statedb.GetLogs(tx.Hash())

cmd/geth/retesteth.go

@@ -671,12 +671,13 @@ func (api *RetestethAPI) AccountRange(ctx context.Context,
 		}
 		// Recompute transactions up to the target index.
 		signer := types.MakeSigner(api.blockchain.Config(), block.Number())
+		context := core.NewEVMBlockContext(block.Header(), api.blockchain, nil)
 		for idx, tx := range block.Transactions() {
 			// Assemble the transaction call message and return if the requested offset
 			msg, _ := tx.AsMessage(signer)
-			context := core.NewEVMContext(msg, block.Header(), api.blockchain, nil)
+			txContext := core.NewEVMTxContext(msg)
 			// Not yet the searched for transaction, execute on top of the current state
-			vmenv := vm.NewEVM(context, statedb, api.blockchain.Config(), vm.Config{})
+			vmenv := vm.NewEVM(context, txContext, statedb, api.blockchain.Config(), vm.Config{})
 			if _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas())); err != nil {
 				return AccountRangeResult{}, fmt.Errorf("transaction %#x failed: %v", tx.Hash(), err)
 			}
@@ -781,12 +782,13 @@ func (api *RetestethAPI) StorageRangeAt(ctx context.Context,
 		}
 		// Recompute transactions up to the target index.
 		signer := types.MakeSigner(api.blockchain.Config(), block.Number())
+		context := core.NewEVMBlockContext(block.Header(), api.blockchain, nil)
 		for idx, tx := range block.Transactions() {
 			// Assemble the transaction call message and return if the requested offset
 			msg, _ := tx.AsMessage(signer)
-			context := core.NewEVMContext(msg, block.Header(), api.blockchain, nil)
+			txContext := core.NewEVMTxContext(msg)
 			// Not yet the searched for transaction, execute on top of the current state
-			vmenv := vm.NewEVM(context, statedb, api.blockchain.Config(), vm.Config{})
+			vmenv := vm.NewEVM(context, txContext, statedb, api.blockchain.Config(), vm.Config{})
 			if _, err := core.ApplyMessage(vmenv, msg, new(core.GasPool).AddGas(tx.Gas())); err != nil {
 				return StorageRangeResult{}, fmt.Errorf("transaction %#x failed: %v", tx.Hash(), err)
 			}

core/evm.go

@@ -35,26 +35,32 @@ type ChainContext interface {
 	GetHeader(common.Hash, uint64) *types.Header
 }
 
-// NewEVMContext creates a new context for use in the EVM.
-func NewEVMContext(msg Message, header *types.Header, chain ChainContext, author *common.Address) vm.Context {
+// NewEVMBlockContext creates a new context for use in the EVM.
+func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common.Address) vm.BlockContext {
 	// If we don't have an explicit author (i.e. not mining), extract from the header
 	var beneficiary common.Address
 	if author == nil {
 		beneficiary, _ = chain.Engine().Author(header) // Ignore error, we're past header validation
 	} else {
 		beneficiary = *author
 	}
-	return vm.Context{
+	return vm.BlockContext{
 		CanTransfer: CanTransfer,
 		Transfer:    Transfer,
 		GetHash:     GetHashFn(header, chain),
-		Origin:      msg.From(),
 		Coinbase:    beneficiary,
 		BlockNumber: new(big.Int).Set(header.Number),
 		Time:        new(big.Int).SetUint64(header.Time),
 		Difficulty:  new(big.Int).Set(header.Difficulty),
 		GasLimit:    header.GasLimit,
-		GasPrice:    new(big.Int).Set(msg.GasPrice()),
+	}
+}
+
+// NewEVMTxContext creates a new transaction context for a single transaction.
+func NewEVMTxContext(msg Message) vm.TxContext {
+	return vm.TxContext{
+		Origin:   msg.From(),
+		GasPrice: new(big.Int).Set(msg.GasPrice()),
 	}
 }
 

core/state_prefetcher.go

@@ -86,8 +86,9 @@ func precacheTransaction(config *params.ChainConfig, bc ChainContext, author *co
 		return err
 	}
 	// Create the EVM and execute the transaction
-	context := NewEVMContext(msg, header, bc, author)
-	vm := vm.NewEVM(context, statedb, config, cfg)
+	context := NewEVMBlockContext(header, bc, author)
+	txContext := NewEVMTxContext(msg)
+	vm := vm.NewEVM(context, txContext, statedb, config, cfg)
 
 	_, err = ApplyMessage(vm, msg, gaspool)
 	return err

core/state_processor.go

@@ -65,10 +65,16 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 	if p.config.DAOForkSupport && p.config.DAOForkBlock != nil && p.config.DAOForkBlock.Cmp(block.Number()) == 0 {
 		misc.ApplyDAOHardFork(statedb)
 	}
+	blockContext := NewEVMBlockContext(header, p.bc, nil)
+	vmenv := vm.NewEVM(blockContext, vm.TxContext{}, statedb, p.config, cfg)
 	// Iterate over and process the individual transactions
 	for i, tx := range block.Transactions() {
+		msg, err := tx.AsMessage(types.MakeSigner(p.config, header.Number))
+		if err != nil {
+			return nil, nil, 0, err
+		}
 		statedb.Prepare(tx.Hash(), block.Hash(), i)
-		receipt, err := ApplyTransaction(p.config, p.bc, nil, gp, statedb, header, tx, usedGas, cfg)
+		receipt, err := applyTransaction(msg, p.config, p.bc, nil, gp, statedb, header, tx, usedGas, vmenv)
 		if err != nil {
 			return nil, nil, 0, err
 		}
@@ -81,34 +87,25 @@ func (p *StateProcessor) Process(block *types.Block, statedb *state.StateDB, cfg
 	return receipts, allLogs, *usedGas, nil
 }
 
-// ApplyTransaction attempts to apply a transaction to the given state database
-// and uses the input parameters for its environment. It returns the receipt
-// for the transaction, gas used and an error if the transaction failed,
-// indicating the block was invalid.
-func ApplyTransaction(config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, cfg vm.Config) (*types.Receipt, error) {
-	msg, err := tx.AsMessage(types.MakeSigner(config, header.Number))
-	if err != nil {
-		return nil, err
-	}
+func applyTransaction(msg types.Message, config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, evm *vm.EVM) (*types.Receipt, error) {
 	// Create a new context to be used in the EVM environment
-	context := NewEVMContext(msg, header, bc, author)
-	// Create a new environment which holds all relevant information
-	// about the transaction and calling mechanisms.
-	vmenv := vm.NewEVM(context, statedb, config, cfg)
-
+	txContext := NewEVMTxContext(msg)
+	// Add addresses to access list if applicable
 	if config.IsYoloV2(header.Number) {
 		statedb.AddAddressToAccessList(msg.From())
 		if dst := msg.To(); dst != nil {
 			statedb.AddAddressToAccessList(*dst)
 			// If it's a create-tx, the destination will be added inside evm.create
 		}
-		for _, addr := range vmenv.ActivePrecompiles() {
+		for _, addr := range evm.ActivePrecompiles() {
 			statedb.AddAddressToAccessList(addr)
 		}
 	}
 
+	// Update the evm with the new transaction context.
+	evm.Reset(txContext, statedb)
 	// Apply the transaction to the current state (included in the env)
-	result, err := ApplyMessage(vmenv, msg, gp)
+	result, err := ApplyMessage(evm, msg, gp)
 	if err != nil {
 		return nil, err
 	}
@@ -128,7 +125,7 @@ func ApplyTransaction(config *params.ChainConfig, bc ChainContext, author *commo
 	receipt.GasUsed = result.UsedGas
 	// if the transaction created a contract, store the creation address in the receipt.
 	if msg.To() == nil {
-		receipt.ContractAddress = crypto.CreateAddress(vmenv.Context.Origin, tx.Nonce())
+		receipt.ContractAddress = crypto.CreateAddress(evm.TxContext.Origin, tx.Nonce())
 	}
 	// Set the receipt logs and create a bloom for filtering
 	receipt.Logs = statedb.GetLogs(tx.Hash())
@@ -139,3 +136,18 @@ func ApplyTransaction(config *params.ChainConfig, bc ChainContext, author *commo
 
 	return receipt, err
 }
+
+// ApplyTransaction attempts to apply a transaction to the given state database
+// and uses the input parameters for its environment. It returns the receipt
+// for the transaction, gas used and an error if the transaction failed,
+// indicating the block was invalid.
+func ApplyTransaction(config *params.ChainConfig, bc ChainContext, author *common.Address, gp *GasPool, statedb *state.StateDB, header *types.Header, tx *types.Transaction, usedGas *uint64, cfg vm.Config) (*types.Receipt, error) {
+	msg, err := tx.AsMessage(types.MakeSigner(config, header.Number))
+	if err != nil {
+		return nil, err
+	}
+	// Create a new context to be used in the EVM environment
+	blockContext := NewEVMBlockContext(header, bc, author)
+	vmenv := vm.NewEVM(blockContext, vm.TxContext{}, statedb, config, cfg)
+	return applyTransaction(msg, config, bc, author, gp, statedb, header, tx, usedGas, vmenv)
+}

core/state_transition.go

@@ -230,8 +230,8 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 	}
 	msg := st.msg
 	sender := vm.AccountRef(msg.From())
-	homestead := st.evm.ChainConfig().IsHomestead(st.evm.BlockNumber)
-	istanbul := st.evm.ChainConfig().IsIstanbul(st.evm.BlockNumber)
+	homestead := st.evm.ChainConfig().IsHomestead(st.evm.Context.BlockNumber)
+	istanbul := st.evm.ChainConfig().IsIstanbul(st.evm.Context.BlockNumber)
 	contractCreation := msg.To() == nil
 
 	// Check clauses 4-5, subtract intrinsic gas if everything is correct
@@ -245,7 +245,7 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 	st.gas -= gas
 
 	// Check clause 6
-	if msg.Value().Sign() > 0 && !st.evm.CanTransfer(st.state, msg.From(), msg.Value()) {
+	if msg.Value().Sign() > 0 && !st.evm.Context.CanTransfer(st.state, msg.From(), msg.Value()) {
 		return nil, ErrInsufficientFundsForTransfer
 	}
 	var (
@@ -260,7 +260,7 @@ func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
 		ret, st.gas, vmerr = st.evm.Call(sender, st.to(), st.data, st.gas, st.value)
 	}
 	st.refundGas()
-	st.state.AddBalance(st.evm.Coinbase, new(big.Int).Mul(new(big.Int).SetUint64(st.gasUsed()), st.gasPrice))
+	st.state.AddBalance(st.evm.Context.Coinbase, new(big.Int).Mul(new(big.Int).SetUint64(st.gasUsed()), st.gasPrice))
 
 	return &ExecutionResult{
 		UsedGas:    st.gasUsed(),

core/vm/evm.go

@@ -91,9 +91,9 @@ func run(evm *EVM, contract *Contract, input []byte, readOnly bool) ([]byte, err
 	return nil, errors.New("no compatible interpreter")
 }
 
-// Context provides the EVM with auxiliary information. Once provided
+// BlockContext provides the EVM with auxiliary information. Once provided
 // it shouldn't be modified.
-type Context struct {
+type BlockContext struct {
 	// CanTransfer returns whether the account contains
 	// sufficient ether to transfer the value
 	CanTransfer CanTransferFunc
@@ -102,10 +102,6 @@ type Context struct {
 	// GetHash returns the hash corresponding to n
 	GetHash GetHashFunc
 
-	// Message information
-	Origin   common.Address // Provides information for ORIGIN
-	GasPrice *big.Int       // Provides information for GASPRICE
-
 	// Block information
 	Coinbase    common.Address // Provides information for COINBASE
 	GasLimit    uint64         // Provides information for GASLIMIT
@@ -114,6 +110,14 @@ type Context struct {
 	Difficulty  *big.Int       // Provides information for DIFFICULTY
 }
 
+// TxContext provides the EVM with information about a transaction.
+// All fields can change between transactions.
+type TxContext struct {
+	// Message information
+	Origin   common.Address // Provides information for ORIGIN
+	GasPrice *big.Int       // Provides information for GASPRICE
+}
+
 // EVM is the Ethereum Virtual Machine base object and provides
 // the necessary tools to run a contract on the given state with
 // the provided context. It should be noted that any error
@@ -125,7 +129,8 @@ type Context struct {
 // The EVM should never be reused and is not thread safe.
 type EVM struct {
 	// Context provides auxiliary blockchain related information
-	Context
+	Context BlockContext
+	TxContext
 	// StateDB gives access to the underlying state
 	StateDB StateDB
 	// Depth is the current call stack
@@ -153,17 +158,18 @@ type EVM struct {
 
 // NewEVM returns a new EVM. The returned EVM is not thread safe and should
 // only ever be used *once*.
-func NewEVM(ctx Context, statedb StateDB, chainConfig *params.ChainConfig, vmConfig Config) *EVM {
+func NewEVM(blockCtx BlockContext, txCtx TxContext, statedb StateDB, chainConfig *params.ChainConfig, vmConfig Config) *EVM {
 	evm := &EVM{
-		Context:      ctx,
+		Context:      blockCtx,
+		TxContext:    txCtx,
 		StateDB:      statedb,
 		vmConfig:     vmConfig,
 		chainConfig:  chainConfig,
-		chainRules:   chainConfig.Rules(ctx.BlockNumber),
+		chainRules:   chainConfig.Rules(blockCtx.BlockNumber),
 		interpreters: make([]Interpreter, 0, 1),
 	}
 
-	if chainConfig.IsEWASM(ctx.BlockNumber) {
+	if chainConfig.IsEWASM(blockCtx.BlockNumber) {
 		// to be implemented by EVM-C and Wagon PRs.
 		// if vmConfig.EWASMInterpreter != "" {
 		//  extIntOpts := strings.Split(vmConfig.EWASMInterpreter, ":")
@@ -187,6 +193,13 @@ func NewEVM(ctx Context, statedb StateDB, chainConfig *params.ChainConfig, vmCon
 	return evm
 }
 
+// Reset resets the EVM with a new transaction context.Reset
+// This is not threadsafe and should only be done very cautiously.
+func (evm *EVM) Reset(txCtx TxContext, statedb StateDB) {
+	evm.TxContext = txCtx
+	evm.StateDB = statedb
+}
+
 // Cancel cancels any running EVM operation. This may be called concurrently and
 // it's safe to be called multiple times.
 func (evm *EVM) Cancel() {
@@ -233,7 +246,7 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
 		}
 		evm.StateDB.CreateAccount(addr)
 	}
-	evm.Transfer(evm.StateDB, caller.Address(), addr, value)
+	evm.Context.Transfer(evm.StateDB, caller.Address(), addr, value)
 
 	// Capture the tracer start/end events in debug mode
 	if evm.vmConfig.Debug && evm.depth == 0 {
@@ -426,7 +439,7 @@ func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64,
 	if evm.depth > int(params.CallCreateDepth) {
 		return nil, common.Address{}, gas, ErrDepth
 	}
-	if !evm.CanTransfer(evm.StateDB, caller.Address(), value) {
+	if !evm.Context.CanTransfer(evm.StateDB, caller.Address(), value) {
 		return nil, common.Address{}, gas, ErrInsufficientBalance
 	}
 	nonce := evm.StateDB.GetNonce(caller.Address())
@@ -447,7 +460,7 @@ func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64,
 	if evm.chainRules.IsEIP158 {
 		evm.StateDB.SetNonce(address, 1)
 	}
-	evm.Transfer(evm.StateDB, caller.Address(), address, value)
+	evm.Context.Transfer(evm.StateDB, caller.Address(), address, value)
 
 	// Initialise a new contract and set the code that is to be used by the EVM.
 	// The contract is a scoped environment for this execution context only.

core/vm/gas_table_test.go

@@ -87,11 +87,11 @@ func TestEIP2200(t *testing.T) {
 		statedb.SetState(address, common.Hash{}, common.BytesToHash([]byte{tt.original}))
 		statedb.Finalise(true) // Push the state into the "original" slot
 
-		vmctx := Context{
+		vmctx := BlockContext{
 			CanTransfer: func(StateDB, common.Address, *big.Int) bool { return true },
 			Transfer:    func(StateDB, common.Address, common.Address, *big.Int) {},
 		}
-		vmenv := NewEVM(vmctx, statedb, params.AllEthashProtocolChanges, Config{ExtraEips: []int{2200}})
+		vmenv := NewEVM(vmctx, TxContext{}, statedb, params.AllEthashProtocolChanges, Config{ExtraEips: []int{2200}})
 
 		_, gas, err := vmenv.Call(AccountRef(common.Address{}), address, nil, tt.gaspool, new(big.Int))
 		if err != tt.failure {