all: generate and embed block-access-lists in block bodies when --experimentalbal is enabled

cmd/evm/blockrunner.go

@@ -89,7 +89,7 @@ func runBlockTest(ctx *cli.Context, fname string) ([]testResult, error) {
 			continue
 		}
 		result := &testResult{Name: name, Pass: true}
-		if err := tests[name].Run(false, rawdb.PathScheme, ctx.Bool(WitnessCrossCheckFlag.Name), tracer, func(res error, chain *core.BlockChain) {
+		if err := tests[name].Run(false, rawdb.PathScheme, ctx.Bool(WitnessCrossCheckFlag.Name), false, tracer, func(res error, chain *core.BlockChain) {
 			if ctx.Bool(DumpFlag.Name) {
 				if s, _ := chain.State(); s != nil {
 					result.State = dump(s)

cmd/geth/main.go

@@ -155,6 +155,7 @@ var (
 		utils.BeaconGenesisTimeFlag,
 		utils.BeaconCheckpointFlag,
 		utils.BeaconCheckpointFileFlag,
+		utils.ExperimentalBALFlag,
 	}, utils.NetworkFlags, utils.DatabaseFlags)
 
 	rpcFlags = []cli.Flag{

cmd/utils/flags.go

@@ -1009,6 +1009,14 @@ Please note that --` + MetricsHTTPFlag.Name + ` must be set to start the server.
 		Value:    metrics.DefaultConfig.InfluxDBOrganization,
 		Category: flags.MetricsCategory,
 	}
+
+	// Block Access List flags
+
+	ExperimentalBALFlag = &cli.BoolFlag{
+		Name:     "experimental.bal",
+		Usage:    "Enable generation of EIP-7928 block access lists when importing post-Cancun blocks which lack them. When this flag is specified, importing blocks containing access lists triggers validation of their correctness and execution based off them. The header block access list field is not set with blocks created when this flag is specified, nor is it validated when importing blocks that contain access lists.  This is used for development purposes only.  Do not enable it otherwise.",
+		Category: flags.MiscCategory,
+	}
 )
 
 var (
@@ -1917,6 +1925,8 @@ func SetEthConfig(ctx *cli.Context, stack *node.Node, cfg *ethconfig.Config) {
 			cfg.VMTraceJsonConfig = ctx.String(VMTraceJsonConfigFlag.Name)
 		}
 	}
+
+	cfg.ExperimentalBAL = ctx.Bool(ExperimentalBALFlag.Name)
 }
 
 // MakeBeaconLightConfig constructs a beacon light client config based on the
@@ -2319,6 +2329,7 @@ func MakeChain(ctx *cli.Context, stack *node.Node, readonly bool) (*core.BlockCh
 	}
 	options.VmConfig = vmcfg
 
+	options.EnableBALForTesting = ctx.Bool(ExperimentalBALFlag.Name)
 	chain, err := core.NewBlockChain(chainDb, gspec, engine, options)
 	if err != nil {
 		Fatalf("Can't create BlockChain: %v", err)

consensus/beacon/consensus.go

@@ -343,9 +343,9 @@ func (beacon *Beacon) Finalize(chain consensus.ChainHeaderReader, header *types.
 
 // FinalizeAndAssemble implements consensus.Engine, setting the final state and
 // assembling the block.
-func (beacon *Beacon) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, body *types.Body, receipts []*types.Receipt) (*types.Block, error) {
+func (beacon *Beacon) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, body *types.Body, receipts []*types.Receipt, onFinalization func()) (*types.Block, error) {
 	if !beacon.IsPoSHeader(header) {
-		return beacon.ethone.FinalizeAndAssemble(chain, header, state, body, receipts)
+		return beacon.ethone.FinalizeAndAssemble(chain, header, state, body, receipts, onFinalization)
 	}
 	shanghai := chain.Config().IsShanghai(header.Number, header.Time)
 	if shanghai {
@@ -364,6 +364,10 @@ func (beacon *Beacon) FinalizeAndAssemble(chain consensus.ChainHeaderReader, hea
 	// Assign the final state root to header.
 	header.Root = state.IntermediateRoot(true)
 
+	if onFinalization != nil {
+		onFinalization()
+	}
+
 	// Assemble the final block.
 	block := types.NewBlock(header, body, receipts, trie.NewStackTrie(nil))
 

consensus/clique/clique.go

@@ -579,7 +579,7 @@ func (c *Clique) Finalize(chain consensus.ChainHeaderReader, header *types.Heade
 
 // FinalizeAndAssemble implements consensus.Engine, ensuring no uncles are set,
 // nor block rewards given, and returns the final block.
-func (c *Clique) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, body *types.Body, receipts []*types.Receipt) (*types.Block, error) {
+func (c *Clique) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, body *types.Body, receipts []*types.Receipt, onFinalize func()) (*types.Block, error) {
 	if len(body.Withdrawals) > 0 {
 		return nil, errors.New("clique does not support withdrawals")
 	}
@@ -589,6 +589,10 @@ func (c *Clique) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *
 	// Assign the final state root to header.
 	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
 
+	if onFinalize != nil {
+		onFinalize()
+	}
+
 	// Assemble and return the final block for sealing.
 	return types.NewBlock(header, &types.Body{Transactions: body.Transactions}, receipts, trie.NewStackTrie(nil)), nil
 }

consensus/consensus.go

@@ -92,7 +92,7 @@ type Engine interface {
 	//
 	// Note: The block header and state database might be updated to reflect any
 	// consensus rules that happen at finalization (e.g. block rewards).
-	FinalizeAndAssemble(chain ChainHeaderReader, header *types.Header, state *state.StateDB, body *types.Body, receipts []*types.Receipt) (*types.Block, error)
+	FinalizeAndAssemble(chain ChainHeaderReader, header *types.Header, state *state.StateDB, body *types.Body, receipts []*types.Receipt, onFinalization func()) (*types.Block, error)
 
 	// Seal generates a new sealing request for the given input block and pushes
 	// the result into the given channel.

consensus/ethash/consensus.go

@@ -511,7 +511,7 @@ func (ethash *Ethash) Finalize(chain consensus.ChainHeaderReader, header *types.
 
 // FinalizeAndAssemble implements consensus.Engine, accumulating the block and
 // uncle rewards, setting the final state and assembling the block.
-func (ethash *Ethash) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, body *types.Body, receipts []*types.Receipt) (*types.Block, error) {
+func (ethash *Ethash) FinalizeAndAssemble(chain consensus.ChainHeaderReader, header *types.Header, state *state.StateDB, body *types.Body, receipts []*types.Receipt, onFinalize func()) (*types.Block, error) {
 	if len(body.Withdrawals) > 0 {
 		return nil, errors.New("ethash does not support withdrawals")
 	}
@@ -521,6 +521,9 @@ func (ethash *Ethash) FinalizeAndAssemble(chain consensus.ChainHeaderReader, hea
 	// Assign the final state root to header.
 	header.Root = state.IntermediateRoot(chain.Config().IsEIP158(header.Number))
 
+	if onFinalize != nil {
+		onFinalize()
+	}
 	// Header seems complete, assemble into a block and return
 	return types.NewBlock(header, &types.Body{Transactions: body.Transactions, Uncles: body.Uncles}, receipts, trie.NewStackTrie(nil)), nil
 }

consensus/misc/eip4844/eip4844.go

@@ -73,6 +73,8 @@ func latestBlobConfig(cfg *params.ChainConfig, time uint64) *BlobConfig {
 		bc = s.BPO2
 	case cfg.IsBPO1(london, time) && s.BPO1 != nil:
 		bc = s.BPO1
+	case cfg.IsAmsterdam(london, time) && s.Amsterdam != nil:
+		bc = s.Amsterdam
 	case cfg.IsOsaka(london, time) && s.Osaka != nil:
 		bc = s.Osaka
 	case cfg.IsPrague(london, time) && s.Prague != nil:

core/block_access_list_tracer.go

@@ -0,0 +1,102 @@
+package core
+
+import (
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core/tracing"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/core/types/bal"
+	"github.com/holiman/uint256"
+	"math/big"
+)
+
+// BlockAccessListTracer is a tracer which gathers state accesses/mutations
+// from the execution of a block.  It is used for constructing and verifying
+// EIP-7928 block access lists.
+type BlockAccessListTracer struct {
+	builder *bal.AccessListBuilder
+
+	// the access list index that changes are currently being recorded into
+	balIdx uint16
+}
+
+// NewBlockAccessListTracer returns an BlockAccessListTracer and a set of hooks
+func NewBlockAccessListTracer() (*BlockAccessListTracer, *tracing.Hooks) {
+	balTracer := &BlockAccessListTracer{
+		builder: bal.NewAccessListBuilder(),
+	}
+	hooks := &tracing.Hooks{
+		OnBlockFinalization:  balTracer.OnBlockFinalization,
+		OnPreTxExecutionDone: balTracer.OnPreTxExecutionDone,
+		OnTxEnd:              balTracer.TxEndHook,
+		OnEnter:              balTracer.OnEnter,
+		OnExit:               balTracer.OnExit,
+		OnCodeChangeV2:       balTracer.OnCodeChange,
+		OnBalanceChange:      balTracer.OnBalanceChange,
+		OnNonceChangeV2:      balTracer.OnNonceChange,
+		OnStorageChange:      balTracer.OnStorageChange,
+		OnStorageRead:        balTracer.OnStorageRead,
+		OnAccountRead:        balTracer.OnAcountRead,
+		OnSelfDestructChange: balTracer.OnSelfDestruct,
+	}
+	wrappedHooks, _ := tracing.WrapWithJournal(hooks)
+	return balTracer, wrappedHooks
+}
+
+// AccessList returns the constructed access list.
+// It is assumed that this is only called after all the block state changes
+// have been executed and the block has been finalized.
+func (a *BlockAccessListTracer) AccessList() *bal.AccessListBuilder {
+	return a.builder
+}
+
+func (a *BlockAccessListTracer) OnPreTxExecutionDone() {
+	a.builder.FinaliseIdxChanges(0)
+	a.balIdx++
+}
+
+func (a *BlockAccessListTracer) TxEndHook(receipt *types.Receipt, err error) {
+	a.builder.FinaliseIdxChanges(a.balIdx)
+	a.balIdx++
+}
+
+func (a *BlockAccessListTracer) OnEnter(depth int, typ byte, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int) {
+	a.builder.EnterScope()
+}
+
+func (a *BlockAccessListTracer) OnExit(depth int, output []byte, gasUsed uint64, err error, reverted bool) {
+	a.builder.ExitScope(reverted)
+}
+
+func (a *BlockAccessListTracer) OnCodeChange(addr common.Address, prevCodeHash common.Hash, prevCode []byte, codeHash common.Hash, code []byte, reason tracing.CodeChangeReason) {
+	a.builder.CodeChange(addr, prevCode, code)
+}
+
+func (a *BlockAccessListTracer) OnSelfDestruct(addr common.Address) {
+	a.builder.SelfDestruct(addr)
+}
+
+func (a *BlockAccessListTracer) OnBlockFinalization() {
+	a.builder.FinaliseIdxChanges(a.balIdx)
+}
+
+func (a *BlockAccessListTracer) OnBalanceChange(addr common.Address, prevBalance, newBalance *big.Int, _ tracing.BalanceChangeReason) {
+	newU256 := new(uint256.Int).SetBytes(newBalance.Bytes())
+	prevU256 := new(uint256.Int).SetBytes(prevBalance.Bytes())
+	a.builder.BalanceChange(addr, prevU256, newU256)
+}
+
+func (a *BlockAccessListTracer) OnNonceChange(addr common.Address, prev uint64, new uint64, reason tracing.NonceChangeReason) {
+	a.builder.NonceChange(addr, prev, new)
+}
+
+func (a *BlockAccessListTracer) OnStorageRead(addr common.Address, key common.Hash) {
+	a.builder.StorageRead(addr, key)
+}
+
+func (a *BlockAccessListTracer) OnAcountRead(addr common.Address) {
+	a.builder.AccountRead(addr)
+}
+
+func (a *BlockAccessListTracer) OnStorageChange(addr common.Address, slot common.Hash, prev common.Hash, new common.Hash) {
+	a.builder.StorageWrite(addr, slot, prev, new)
+}

core/block_validator.go

@@ -111,6 +111,31 @@ func (v *BlockValidator) ValidateBody(block *types.Block) error {
 		}
 	}
 
+	// block access lists must be present after the Amsterdam hard fork
+	if v.config.IsAmsterdam(block.Number(), block.Time()) {
+		if block.Body().AccessList == nil {
+			return fmt.Errorf("access list not present in block body")
+		} else if *block.Header().BlockAccessListHash != block.Body().AccessList.Hash() {
+			return fmt.Errorf("access list hash mismatch.  local: %x. remote: %x\n", block.Body().AccessList.Hash(), *block.Header().BlockAccessListHash)
+		} else if err := block.Body().AccessList.Validate(); err != nil {
+			return fmt.Errorf("invalid block access list: %v", err)
+		}
+	} else if !v.bc.cfg.EnableBALForTesting {
+		// if --experimental.bal is not enabled, block headers cannot have access list hash and bodies cannot have access lists.
+		if block.Body().AccessList != nil {
+			return fmt.Errorf("access list not allowed in block body if not in amsterdam or --experimental.bal is set")
+		} else if block.Header().BlockAccessListHash != nil {
+			return fmt.Errorf("access list hash in block header not allowed when --experimental.bal is set")
+		}
+	} else {
+		// if --experimental.bal is enabled, the BAL hash is not allowed in the header.
+		// this is in order that Geth can import pre-existing chains augmented with BALs
+		// and not have a hash mismatch.
+		if block.Header().BlockAccessListHash != nil {
+			return fmt.Errorf("access list hash in block header not allowed pre-amsterdam")
+		}
+	}
+
 	// Ancestor block must be known.
 	if !v.bc.HasBlockAndState(block.ParentHash(), block.NumberU64()-1) {
 		if !v.bc.HasBlock(block.ParentHash(), block.NumberU64()-1) {

core/blockchain.go

@@ -196,6 +196,11 @@ type BlockChainConfig struct {
 	// If the value is -1, indexing is disabled.
 	TxLookupLimit int64
 
+	// If EnableBALForTesting is enabled, block access lists will be created
+	// from block execution and embedded in the body.  The block access list
+	// hash will not be set in the header.
+	EnableBALForTesting bool
+
 	// StateSizeTracking indicates whether the state size tracking is enabled.
 	StateSizeTracking bool
 }
@@ -1911,7 +1916,11 @@ func (bc *BlockChain) insertChain(chain types.Blocks, setHead bool, makeWitness
 		}
 		// The traced section of block import.
 		start := time.Now()
-		res, err := bc.ProcessBlock(parent.Root, block, setHead, makeWitness && len(chain) == 1)
+		enableBAL := (bc.cfg.EnableBALForTesting && bc.chainConfig.IsCancun(block.Number(), block.Time())) || bc.chainConfig.IsAmsterdam(block.Number(), block.Time())
+		blockHasAccessList := block.Body().AccessList != nil
+		constructBAL := enableBAL && !blockHasAccessList
+
+		res, err := bc.ProcessBlock(parent.Root, block, setHead, makeWitness && len(chain) == 1, constructBAL, false)
 		if err != nil {
 			return nil, it.index, err
 		}
@@ -1983,7 +1992,7 @@ func (bpr *blockProcessingResult) Witness() *stateless.Witness {
 
 // ProcessBlock executes and validates the given block. If there was no error
 // it writes the block and associated state to database.
-func (bc *BlockChain) ProcessBlock(parentRoot common.Hash, block *types.Block, setHead bool, makeWitness bool) (_ *blockProcessingResult, blockEndErr error) {
+func (bc *BlockChain) ProcessBlock(parentRoot common.Hash, block *types.Block, setHead bool, makeWitness bool, constructBALForTesting bool, validateBAL bool) (_ *blockProcessingResult, blockEndErr error) {
 	var (
 		err       error
 		startTime = time.Now()
@@ -2079,6 +2088,14 @@ func (bc *BlockChain) ProcessBlock(parentRoot common.Hash, block *types.Block, s
 		}()
 	}
 
+	var balTracer *BlockAccessListTracer
+	// Process block using the parent state as reference point
+	if constructBALForTesting {
+		balTracer, bc.cfg.VmConfig.Tracer = NewBlockAccessListTracer()
+		defer func() {
+			bc.cfg.VmConfig.Tracer = nil
+		}()
+	}
 	// Process block using the parent state as reference point
 	pstart := time.Now()
 	res, err := bc.processor.Process(block, statedb, bc.cfg.VmConfig)
@@ -2088,11 +2105,24 @@ func (bc *BlockChain) ProcessBlock(parentRoot common.Hash, block *types.Block, s
 	}
 	ptime := time.Since(pstart)
 
+	if constructBALForTesting {
+		balTracer.OnBlockFinalization()
+	}
+
 	vstart := time.Now()
 	if err := bc.validator.ValidateState(block, statedb, res, false); err != nil {
 		bc.reportBlock(block, res, err)
 		return nil, err
 	}
+	if constructBALForTesting {
+		// very ugly... deep-copy the block body before setting the block access
+		// list on it to prevent mutating the block instance passed by the caller.
+		existingBody := block.Body()
+		block = block.WithBody(*existingBody)
+		existingBody = block.Body()
+		existingBody.AccessList = balTracer.AccessList().ToEncodingObj()
+		block = block.WithBody(*existingBody)
+	}
 	vtime := time.Since(vstart)
 
 	// If witnesses was generated and stateless self-validation requested, do

core/chain_makers.go

@@ -410,7 +410,7 @@ func GenerateChain(config *params.ChainConfig, parent *types.Block, engine conse
 		}
 
 		body := types.Body{Transactions: b.txs, Uncles: b.uncles, Withdrawals: b.withdrawals}
-		block, err := b.engine.FinalizeAndAssemble(cm, b.header, statedb, &body, b.receipts)
+		block, err := b.engine.FinalizeAndAssemble(cm, b.header, statedb, &body, b.receipts, nil)
 		if err != nil {
 			panic(err)
 		}
@@ -520,7 +520,7 @@ func GenerateVerkleChain(config *params.ChainConfig, parent *types.Block, engine
 			Uncles:       b.uncles,
 			Withdrawals:  b.withdrawals,
 		}
-		block, err := b.engine.FinalizeAndAssemble(cm, b.header, statedb, body, b.receipts)
+		block, err := b.engine.FinalizeAndAssemble(cm, b.header, statedb, body, b.receipts, nil)
 		if err != nil {
 			panic(err)
 		}