- fix issue with not using proper parent block excess data gas by making excess data gas an explicit part of the EVM block context

- add initial enforcement of block level data gas limit

Author: roberto-bayardo

accounts/abi/bind/backends/simulated.go

@@ -642,7 +642,14 @@ func (b *SimulatedBackend) callContract(ctx context.Context, call ethereum.CallM
 	msg := callMsg{call}
 
 	txContext := core.NewEVMTxContext(msg)
-	evmContext := core.NewEVMBlockContext(block.Header(), b.blockchain, nil)
+
+	var excessDataGas *big.Int
+	// Get the last block header
+	ph := b.blockchain.GetHeaderByHash(block.ParentHash())
+	if ph != nil {
+		excessDataGas = ph.ExcessDataGas
+	}
+	evmContext := core.NewEVMBlockContext(block.Header(), excessDataGas, b.blockchain, nil)
 	// Create a new environment which holds all relevant information
 	// about the transaction and calling mechanisms.
 	vmEnv := vm.NewEVM(evmContext, txContext, stateDB, b.config, vm.Config{NoBaseFee: true})

consensus/beacon/consensus.go

@@ -346,6 +346,8 @@ func (beacon *Beacon) Finalize(chain consensus.ChainHeaderReader, header *types.
 	if chain.Config().IsSharding(header.Number) {
 		if parent := chain.GetHeaderByHash(header.ParentHash); parent != nil {
 			header.SetExcessDataGas(misc.CalcExcessDataGas(parent.ExcessDataGas, misc.CountBlobs(txs)))
+		} else {
+			header.SetExcessDataGas(new(big.Int))
 		}
 	}
 }

consensus/clique/clique.go

@@ -579,6 +579,8 @@ func (c *Clique) Finalize(chain consensus.ChainHeaderReader, header *types.Heade
 	if chain.Config().IsSharding(header.Number) {
 		if parent := chain.GetHeaderByHash(header.ParentHash); parent != nil {
 			header.SetExcessDataGas(misc.CalcExcessDataGas(parent.ExcessDataGas, misc.CountBlobs(txs)))
+		} else {
+			header.SetExcessDataGas(new(big.Int))
 		}
 	}
 }

consensus/ethash/consensus.go

@@ -612,6 +612,8 @@ func (ethash *Ethash) Finalize(chain consensus.ChainHeaderReader, header *types.
 	if chain.Config().IsSharding(header.Number) {
 		if parent := chain.GetHeaderByHash(header.ParentHash); parent != nil {
 			header.SetExcessDataGas(misc.CalcExcessDataGas(parent.ExcessDataGas, misc.CountBlobs(txs)))
+		} else {
+			header.SetExcessDataGas(new(big.Int))
 		}
 	}
 }

consensus/misc/eip4844_test.go

@@ -28,7 +28,11 @@ func TestFakeExponential(t *testing.T) {
 		factor, num, denom int64
 		want               int64
 	}{
-		{1, 2, 1, 6}, // approximate 7.389
+		// When num==0 the return value should always equal the value of factor
+		{1, 0, 1, 1},
+		{38493, 0, 1000, 38493},
+		{0, 1234, 2345, 0}, // should be 0
+		{1, 2, 1, 6},       // approximate 7.389
 		{1, 4, 2, 6},
 		{1, 3, 1, 16}, // approximate 20.09
 		{1, 6, 2, 18},

core/blockchain.go

@@ -1656,7 +1656,7 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 				throwaway, _ := state.New(parent.Root, bc.stateCache, bc.snaps)
 
 				go func(start time.Time, followup *types.Block, throwaway *state.StateDB, interrupt *uint32) {
-					bc.prefetcher.Prefetch(followup, throwaway, bc.vmConfig, &followupInterrupt)
+					bc.prefetcher.Prefetch(followup, parent.ExcessDataGas, throwaway, bc.vmConfig, &followupInterrupt)
 
 					blockPrefetchExecuteTimer.Update(time.Since(start))
 					if atomic.LoadUint32(interrupt) == 1 {
@@ -1668,7 +1668,7 @@ func (bc *BlockChain) insertChain(chain types.Blocks, verifySeals, setHead bool)
 
 		// Process block using the parent state as reference point
 		substart := time.Now()
-		receipts, logs, usedGas, err := bc.processor.Process(block, statedb, bc.vmConfig)
+		receipts, logs, usedGas, err := bc.processor.Process(block, parent.ExcessDataGas, statedb, bc.vmConfig)
 		if err != nil {
 			bc.reportBlock(block, receipts, err)
 			atomic.StoreUint32(&followupInterrupt, 1)

core/blockchain_test.go

@@ -156,11 +156,12 @@ func testBlockChainImport(chain types.Blocks, blockchain *BlockChain) error {
 			}
 			return err
 		}
-		statedb, err := state.New(blockchain.GetBlockByHash(block.ParentHash()).Root(), blockchain.stateCache, nil)
+		parent := blockchain.GetBlockByHash(block.ParentHash())
+		statedb, err := state.New(parent.Root(), blockchain.stateCache, nil)
 		if err != nil {
 			return err
 		}
-		receipts, _, usedGas, err := blockchain.processor.Process(block, statedb, vm.Config{})
+		receipts, _, usedGas, err := blockchain.processor.Process(block, parent.Header().ExcessDataGas, statedb, vm.Config{})
 		if err != nil {
 			blockchain.reportBlock(block, receipts, err)
 			return err
@@ -3913,7 +3914,6 @@ func TestDataBlobTxs(t *testing.T) {
 
 	blocks, _ := GenerateChain(gspec.Config, genesis, engine, db, 1, func(i int, b *BlockGen) {
 		b.SetCoinbase(common.Address{1})
-		b.SetExcessDataGas(new(big.Int))
 		msg := types.BlobTxMessage{
 			Nonce: 0,
 			Gas:   500000,

core/chain_makers.go

@@ -58,7 +58,7 @@ func (b *BlockGen) SetCoinbase(addr common.Address) {
 		panic("coinbase can only be set once")
 	}
 	b.header.Coinbase = addr
-	b.gasPool = new(GasPool).AddGas(b.header.GasLimit)
+	b.gasPool = new(GasPool).AddGas(b.header.GasLimit).AddDataGas(params.MaxDataGasPerBlock)
 }
 
 // SetExtra sets the extra data field of the generated block.
@@ -78,11 +78,6 @@ func (b *BlockGen) SetDifficulty(diff *big.Int) {
 	b.header.Difficulty = diff
 }
 
-// SetExcessDataGas sets the excess_data_gas field of the generated block.
-func (b *BlockGen) SetExcessDataGas(excessDataGas *big.Int) {
-	b.header.SetExcessDataGas(excessDataGas)
-}
-
 // AddTx adds a transaction to the generated block. If no coinbase has
 // been set, the block's coinbase is set to the zero address.
 //
@@ -108,7 +103,7 @@ func (b *BlockGen) AddTxWithChain(bc *BlockChain, tx *types.Transaction) {
 		b.SetCoinbase(common.Address{})
 	}
 	b.statedb.Prepare(tx.Hash(), len(b.txs))
-	receipt, err := ApplyTransaction(b.config, bc, &b.header.Coinbase, b.gasPool, b.statedb, b.header, tx, &b.header.GasUsed, vm.Config{})
+	receipt, err := ApplyTransaction(b.config, bc, &b.header.Coinbase, b.gasPool, b.statedb, b.header, b.parent.Header().ExcessDataGas, tx, &b.header.GasUsed, vm.Config{})
 	if err != nil {
 		panic(err)
 	}
@@ -140,15 +135,6 @@ func (b *BlockGen) BaseFee() *big.Int {
 	return new(big.Int).Set(b.header.BaseFee)
 }
 
-// ExcessDataGas returns the EIP-4844 excess_data_gas of the block being generated.
-func (b *BlockGen) ExcessDataGas() *big.Int {
-	v := new(big.Int)
-	if b.header.ExcessDataGas != nil {
-		v.Set(b.header.ExcessDataGas)
-	}
-	return v
-}
-
 // AddUncheckedReceipt forcefully adds a receipts to the block without a
 // backing transaction.
 //

core/evm.go

@@ -36,12 +36,15 @@ type ChainContext interface {
 }
 
 // NewEVMBlockContext creates a new context for use in the EVM.
-func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common.Address) vm.BlockContext {
+//
+// excessDataGas must be set to the excessDataGas value from the *parent* block header, and can be
+// nil if the parent block is not of EIP-4844 type. It is read only.
+func NewEVMBlockContext(header *types.Header, excessDataGas *big.Int, chain ChainContext, author *common.Address) vm.BlockContext {
 	var (
-		beneficiary   common.Address
-		baseFee       *big.Int
-		random        *common.Hash
-		excessDataGas *big.Int
+		beneficiary common.Address
+		baseFee     *big.Int
+		random      *common.Hash
+		edg         *big.Int
 	)
 
 	// If we don't have an explicit author (i.e. not mining), extract from the header
@@ -56,8 +59,8 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 	if header.Difficulty.Cmp(common.Big0) == 0 {
 		random = &header.MixDigest
 	}
-	if header.ExcessDataGas != nil {
-		excessDataGas = new(big.Int).Set(header.ExcessDataGas)
+	if excessDataGas != nil {
+		edg = new(big.Int).Set(excessDataGas)
 	}
 	return vm.BlockContext{
 		CanTransfer:   CanTransfer,
@@ -68,7 +71,7 @@ func NewEVMBlockContext(header *types.Header, chain ChainContext, author *common
 		Time:          new(big.Int).SetUint64(header.Time),
 		Difficulty:    new(big.Int).Set(header.Difficulty),
 		BaseFee:       baseFee,
-		ExcessDataGas: excessDataGas,
+		ExcessDataGas: edg,
 		GasLimit:      header.GasLimit,
 		Random:        random,
 	}

core/gaspool.go

@@ -23,32 +23,58 @@ import (
 
 // GasPool tracks the amount of gas available during execution of the transactions
 // in a block. The zero value is a pool with zero gas available.
-type GasPool uint64
+type GasPool struct {
+	gas, dataGas uint64
+}
 
 // AddGas makes gas available for execution.
 func (gp *GasPool) AddGas(amount uint64) *GasPool {
-	if uint64(*gp) > math.MaxUint64-amount {
+	if gp.gas > math.MaxUint64-amount {
 		panic("gas pool pushed above uint64")
 	}
-	*(*uint64)(gp) += amount
+	gp.gas += amount
 	return gp
 }
 
 // SubGas deducts the given amount from the pool if enough gas is
 // available and returns an error otherwise.
 func (gp *GasPool) SubGas(amount uint64) error {
-	if uint64(*gp) < amount {
+	if gp.gas < amount {
 		return ErrGasLimitReached
 	}
-	*(*uint64)(gp) -= amount
+	gp.gas -= amount
 	return nil
 }
 
 // Gas returns the amount of gas remaining in the pool.
 func (gp *GasPool) Gas() uint64 {
-	return uint64(*gp)
+	return gp.gas
+}
+
+// AddDataGas makes data gas available for execution.
+func (gp *GasPool) AddDataGas(amount uint64) *GasPool {
+	if gp.dataGas > math.MaxUint64-amount {
+		panic("data gas pool pushed above uint64")
+	}
+	gp.dataGas += amount
+	return gp
+}
+
+// SubDataGas deducts the given amount from the pool if enough data gas is available and returns an
+// error otherwise.
+func (gp *GasPool) SubDataGas(amount uint64) error {
+	if gp.dataGas < amount {
+		return ErrGasLimitReached
+	}
+	gp.dataGas -= amount
+	return nil
+}
+
+// DataGas returns the amount of data gas remaining in the pool.
+func (gp *GasPool) DataGas() uint64 {
+	return gp.dataGas
 }
 
 func (gp *GasPool) String() string {
-	return fmt.Sprintf("%d", *gp)
+	return fmt.Sprintf("gas: %d, data_gas: %d", gp.gas, gp.dataGas)
 }