Merge branch 'libevm' into arr4n/chainconfig-check-hooks

Author: ARR4N

core/evm.go

@@ -73,6 +73,7 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 		BlobBaseFee: blobBaseFee,
 		GasLimit:    header.GasLimit,
 		Random:      random,
+		Header:      header,
 	}
 }
 

core/vm/contracts.go

@@ -174,8 +174,7 @@ func (args *evmCallArgs) RunPrecompiledContract(p PrecompiledContract, input []b
 		return nil, 0, ErrOutOfGas
 	}
 	suppliedGas -= gasCost
-	output, err := args.run(p, input)
-	return output, suppliedGas, err
+	return args.run(p, input, suppliedGas)
 }
 
 // ECRECOVER implemented as a native contract.

core/vm/contracts.libevm.go

@@ -2,10 +2,12 @@ package vm
 
 import (
 	"fmt"
+	"math/big"
 
 	"github.com/holiman/uint256"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/libevm"
 	"github.com/ethereum/go-ethereum/params"
 )
@@ -50,42 +52,43 @@ const (
 
 // run runs the [PrecompiledContract], differentiating between stateful and
 // regular types.
-func (args *evmCallArgs) run(p PrecompiledContract, input []byte) (ret []byte, err error) {
+func (args *evmCallArgs) run(p PrecompiledContract, input []byte, suppliedGas uint64) (ret []byte, remainingGas uint64, err error) {
 	if p, ok := p.(statefulPrecompile); ok {
-		return p.run(args, input)
+		return p(args, input, suppliedGas)
 	}
-	return p.Run(input)
+	// Gas consumption for regular precompiles was already handled by the native
+	// RunPrecompiledContract(), which called this method.
+	ret, err = p.Run(input)
+	return ret, suppliedGas, err
 }
 
-// PrecompiledStatefulRun is the stateful equivalent of the Run() method of a
+// PrecompiledStatefulContract is the stateful equivalent of a
 // [PrecompiledContract].
-type PrecompiledStatefulRun func(env PrecompileEnvironment, input []byte) ([]byte, error)
+type PrecompiledStatefulContract func(env PrecompileEnvironment, input []byte, suppliedGas uint64) (ret []byte, remainingGas uint64, err error)
 
 // NewStatefulPrecompile constructs a new PrecompiledContract that can be used
 // via an [EVM] instance but MUST NOT be called directly; a direct call to Run()
 // reserves the right to panic. See other requirements defined in the comments
 // on [PrecompiledContract].
-func NewStatefulPrecompile(run PrecompiledStatefulRun, requiredGas func([]byte) uint64) PrecompiledContract {
-	return statefulPrecompile{
-		gas: requiredGas,
-		run: run,
-	}
+func NewStatefulPrecompile(run PrecompiledStatefulContract) PrecompiledContract {
+	return statefulPrecompile(run)
 }
 
-type statefulPrecompile struct {
-	gas func([]byte) uint64
-	run PrecompiledStatefulRun
-}
+// statefulPrecompile implements the [PrecompiledContract] interface to allow a
+// [PrecompiledStatefulContract] to be carried with regular geth plumbing. The
+// methods are defined on this unexported type instead of directly on
+// [PrecompiledStatefulContract] to hide implementation details.
+type statefulPrecompile PrecompiledStatefulContract
 
-func (p statefulPrecompile) RequiredGas(input []byte) uint64 {
-	return p.gas(input)
-}
+// RequiredGas always returns zero as this gas is consumed by native geth code
+// before the contract is run.
+func (statefulPrecompile) RequiredGas([]byte) uint64 { return 0 }
 
 func (p statefulPrecompile) Run([]byte) ([]byte, error) {
 	// https://google.github.io/styleguide/go/best-practices.html#when-to-panic
 	// This would indicate an API misuse and would occur in tests, not in
 	// production.
-	panic(fmt.Sprintf("BUG: call to %T.Run(); MUST call %T", p, p.run))
+	panic(fmt.Sprintf("BUG: call to %T.Run(); MUST call %T itself", p, p))
 }
 
 // A PrecompileEnvironment provides information about the context in which a
@@ -98,6 +101,10 @@ type PrecompileEnvironment interface {
 	// ReadOnlyState will always be non-nil.
 	ReadOnlyState() libevm.StateReader
 	Addresses() *libevm.AddressContext
+
+	BlockHeader() (types.Header, error)
+	BlockNumber() *big.Int
+	BlockTime() uint64
 }
 
 //
@@ -151,6 +158,24 @@ func (args *evmCallArgs) Addresses() *libevm.AddressContext {
 	}
 }
 
+func (args *evmCallArgs) BlockHeader() (types.Header, error) {
+	hdr := args.evm.Context.Header
+	if hdr == nil {
+		// Although [core.NewEVMBlockContext] sets the field and is in the
+		// typical hot path (e.g. miner), there are other ways to create a
+		// [vm.BlockContext] (e.g. directly in tests) that may result in no
+		// available header.
+		return types.Header{}, fmt.Errorf("nil %T in current %T", hdr, args.evm.Context)
+	}
+	return *hdr, nil
+}
+
+func (args *evmCallArgs) BlockNumber() *big.Int {
+	return new(big.Int).Set(args.evm.Context.BlockNumber)
+}
+
+func (args *evmCallArgs) BlockTime() uint64 { return args.evm.Context.Time }
+
 var (
 	// These lock in the assumptions made when implementing [evmCallArgs]. If
 	// these break then the struct fields SHOULD be changed to match these

core/vm/contracts.libevm_test.go

@@ -3,6 +3,8 @@ package vm_test
 import (
 	"fmt"
 	"math/big"
+	"reflect"
+	"strings"
 	"testing"
 
 	"github.com/holiman/uint256"
@@ -11,6 +13,8 @@ import (
 	"golang.org/x/exp/rand"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
+	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/libevm"
@@ -79,6 +83,31 @@ func TestPrecompileOverride(t *testing.T) {
 	}
 }
 
+type statefulPrecompileOutput struct {
+	Caller, Self            common.Address
+	StateValue              common.Hash
+	ReadOnly                bool
+	BlockNumber, Difficulty *big.Int
+	BlockTime               uint64
+	Input                   []byte
+}
+
+func (o statefulPrecompileOutput) String() string {
+	var lines []string
+	out := reflect.ValueOf(o)
+	for i, n := 0, out.NumField(); i < n; i++ {
+		name := out.Type().Field(i).Name
+		fld := out.Field(i).Interface()
+
+		verb := "%v"
+		if _, ok := fld.([]byte); ok {
+			verb = "%#x"
+		}
+		lines = append(lines, fmt.Sprintf("%s: "+verb, name, fld))
+	}
+	return strings.Join(lines, "\n")
+}
+
 func TestNewStatefulPrecompile(t *testing.T) {
 	rng := ethtest.NewPseudoRand(314159)
 	precompile := rng.Address()
@@ -87,38 +116,47 @@ func TestNewStatefulPrecompile(t *testing.T) {
 	const gasLimit = 1e6
 	gasCost := rng.Uint64n(gasLimit)
 
-	makeOutput := func(caller, self common.Address, input []byte, stateVal common.Hash, readOnly bool) []byte {
-		return []byte(fmt.Sprintf(
-			"Caller: %v Precompile: %v State: %v Read-only: %t, Input: %#x",
-			caller, self, stateVal, readOnly, input,
-		))
-	}
-	run := func(env vm.PrecompileEnvironment, input []byte) ([]byte, error) {
+	run := func(env vm.PrecompileEnvironment, input []byte, suppliedGas uint64) ([]byte, uint64, error) {
 		if got, want := env.StateDB() != nil, !env.ReadOnly(); got != want {
-			return nil, fmt.Errorf("PrecompileEnvironment().StateDB() must be non-nil i.f.f. not read-only; got non-nil? %t; want %t", got, want)
+			return nil, 0, fmt.Errorf("PrecompileEnvironment().StateDB() must be non-nil i.f.f. not read-only; got non-nil? %t; want %t", got, want)
+		}
+		hdr, err := env.BlockHeader()
+		if err != nil {
+			return nil, 0, err
 		}
 
 		addrs := env.Addresses()
-		val := env.ReadOnlyState().GetState(precompile, slot)
-		return makeOutput(addrs.Caller, addrs.Self, input, val, env.ReadOnly()), nil
+		out := &statefulPrecompileOutput{
+			Caller:      addrs.Caller,
+			Self:        addrs.Self,
+			StateValue:  env.ReadOnlyState().GetState(precompile, slot),
+			ReadOnly:    env.ReadOnly(),
+			BlockNumber: env.BlockNumber(),
+			BlockTime:   env.BlockTime(),
+			Difficulty:  hdr.Difficulty,
+			Input:       input,
+		}
+		return []byte(out.String()), suppliedGas - gasCost, nil
 	}
 	hooks := &hookstest.Stub{
 		PrecompileOverrides: map[common.Address]libevm.PrecompiledContract{
-			precompile: vm.NewStatefulPrecompile(
-				run,
-				func(b []byte) uint64 {
-					return gasCost
-				},
-			),
+			precompile: vm.NewStatefulPrecompile(run),
 		},
 	}
 	hooks.Register(t)
 
+	header := &types.Header{
+		Number:     rng.BigUint64(),
+		Time:       rng.Uint64(),
+		Difficulty: rng.BigUint64(),
+	}
 	caller := rng.Address()
 	input := rng.Bytes(8)
 	value := rng.Hash()
 
-	state, evm := ethtest.NewZeroEVM(t)
+	state, evm := ethtest.NewZeroEVM(t, ethtest.WithBlockContext(
+		core.NewEVMBlockContext(header, nil, rng.AddressPtr()),
+	))
 	state.SetState(precompile, slot, value)
 
 	tests := []struct {
@@ -160,12 +198,21 @@ func TestNewStatefulPrecompile(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			wantReturnData := makeOutput(caller, precompile, input, value, tt.wantReadOnly)
+			wantReturnData := statefulPrecompileOutput{
+				Caller:      caller,
+				Self:        precompile,
+				StateValue:  value,
+				ReadOnly:    tt.wantReadOnly,
+				BlockNumber: header.Number,
+				BlockTime:   header.Time,
+				Difficulty:  header.Difficulty,
+				Input:       input,
+			}.String()
 			wantGasLeft := gasLimit - gasCost
 
 			gotReturnData, gotGasLeft, err := tt.call()
 			require.NoError(t, err)
-			assert.Equal(t, string(wantReturnData), string(gotReturnData))
+			assert.Equal(t, wantReturnData, string(gotReturnData))
 			assert.Equal(t, wantGasLeft, gotGasLeft)
 		})
 	}
@@ -204,13 +251,12 @@ func TestInheritReadOnly(t *testing.T) {
 	hooks := &hookstest.Stub{
 		PrecompileOverrides: map[common.Address]libevm.PrecompiledContract{
 			precompile: vm.NewStatefulPrecompile(
-				func(env vm.PrecompileEnvironment, input []byte) ([]byte, error) {
+				func(env vm.PrecompileEnvironment, input []byte, suppliedGas uint64) ([]byte, uint64, error) {
 					if env.ReadOnly() {
-						return []byte{ifReadOnly}, nil
+						return []byte{ifReadOnly}, suppliedGas, nil
 					}
-					return []byte{ifNotReadOnly}, nil
+					return []byte{ifNotReadOnly}, suppliedGas, nil
 				},
-				func([]byte) uint64 { return 0 },
 			),
 		},
 	}
@@ -296,20 +342,23 @@ func TestCanCreateContract(t *testing.T) {
 	account := rng.Address()
 	slot := rng.Hash()
 
+	const gasLimit uint64 = 1e6
+	gasUsage := rng.Uint64n(gasLimit)
+
 	makeErr := func(cc *libevm.AddressContext, stateVal common.Hash) error {
 		return fmt.Errorf("Origin: %v Caller: %v Contract: %v State: %v", cc.Origin, cc.Caller, cc.Self, stateVal)
 	}
 	hooks := &hookstest.Stub{
-		CanCreateContractFn: func(cc *libevm.AddressContext, s libevm.StateReader) error {
-			return makeErr(cc, s.GetState(account, slot))
+		CanCreateContractFn: func(cc *libevm.AddressContext, gas uint64, s libevm.StateReader) (uint64, error) {
+			return gas - gasUsage, makeErr(cc, s.GetState(account, slot))
 		},
 	}
 	hooks.Register(t)
 
 	origin := rng.Address()
 	caller := rng.Address()
 	value := rng.Hash()
-	code := rng.Bytes(8)
+	code := []byte{byte(vm.STOP)}
 	salt := rng.Hash()
 
 	create := crypto.CreateAddress(caller, 0)
@@ -323,14 +372,14 @@ func TestCanCreateContract(t *testing.T) {
 		{
 			name: "Create",
 			create: func(evm *vm.EVM) ([]byte, common.Address, uint64, error) {
-				return evm.Create(vm.AccountRef(caller), code, 1e6, uint256.NewInt(0))
+				return evm.Create(vm.AccountRef(caller), code, gasLimit, uint256.NewInt(0))
 			},
 			wantErr: makeErr(&libevm.AddressContext{Origin: origin, Caller: caller, Self: create}, value),
 		},
 		{
 			name: "Create2",
 			create: func(evm *vm.EVM) ([]byte, common.Address, uint64, error) {
-				return evm.Create2(vm.AccountRef(caller), code, 1e6, uint256.NewInt(0), new(uint256.Int).SetBytes(salt[:]))
+				return evm.Create2(vm.AccountRef(caller), code, gasLimit, uint256.NewInt(0), new(uint256.Int).SetBytes(salt[:]))
 			},
 			wantErr: makeErr(&libevm.AddressContext{Origin: origin, Caller: caller, Self: create2}, value),
 		},
@@ -342,8 +391,10 @@ func TestCanCreateContract(t *testing.T) {
 			state.SetState(account, slot, value)
 			evm.TxContext.Origin = origin
 
-			_, _, _, err := tt.create(evm)
+			_, _, gasRemaining, err := tt.create(evm)
 			require.EqualError(t, err, tt.wantErr.Error())
+			// require prints uint64s in hex
+			require.Equal(t, int(gasLimit-gasUsage), int(gasRemaining), "gas remaining") //nolint:gosec // G115 won't overflow as <= 1e6
 		})
 	}
 }

core/vm/evm.go

@@ -79,6 +79,8 @@ type BlockContext struct {
 	BaseFee     *big.Int       // Provides information for BASEFEE (0 if vm runs with NoBaseFee flag and 0 gas price)
 	BlobBaseFee *big.Int       // Provides information for BLOBBASEFEE (0 if vm runs with NoBaseFee flag and 0 blob gas price)
 	Random      *common.Hash   // Provides information for PREVRANDAO
+
+	Header *types.Header // libevm addition; not guaranteed to be set
 }
 
 // TxContext provides the EVM with information about a transaction.
@@ -428,10 +430,6 @@ func (c *codeAndHash) Hash() common.Hash {
 
 // create creates a new contract using code as deployment code.
 func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64, value *uint256.Int, address common.Address, typ OpCode) ([]byte, common.Address, uint64, error) {
-	cc := &libevm.AddressContext{Origin: evm.Origin, Caller: caller.Address(), Self: address}
-	if err := evm.chainRules.Hooks().CanCreateContract(cc, evm.StateDB); err != nil {
-		return nil, common.Address{}, gas, err
-	}
 	// Depth check execution. Fail if we're trying to execute above the
 	// limit.
 	if evm.depth > int(params.CallCreateDepth) {
@@ -455,6 +453,19 @@ func (evm *EVM) create(caller ContractRef, codeAndHash *codeAndHash, gas uint64,
 	if evm.StateDB.GetNonce(address) != 0 || (contractHash != (common.Hash{}) && contractHash != types.EmptyCodeHash) {
 		return nil, common.Address{}, 0, ErrContractAddressCollision
 	}
+
+	//libevm:start
+	//
+	// This check MUST be placed after the caller's nonce is incremented but
+	// before all other state-modifying behaviour, even if changes may be
+	// reverted to the snapshot.
+	addrs := &libevm.AddressContext{Origin: evm.Origin, Caller: caller.Address(), Self: address}
+	gas, err := evm.chainRules.Hooks().CanCreateContract(addrs, gas, evm.StateDB)
+	if err != nil {
+		return nil, common.Address{}, gas, err
+	}
+	//libevm:end
+
 	// Create a new account on the state
 	snapshot := evm.StateDB.Snapshot()
 	evm.StateDB.CreateAccount(address)