consensus/misc/eip4844: more changes for blob gas calculation (#31128)

This PR changes the signature of `CalcExcessBlobGas` to take in just
the header timestamp instead of the whole object. It also adds a sanity
check for the parent->child block order to `VerifyEIP4844Header`.

Author: fjl

cmd/evm/internal/t8ntool/execution.go

@@ -198,7 +198,7 @@ func (pre *Prestate) Apply(vmConfig vm.Config, chainConfig *params.ChainConfig,
 				Time:          pre.Env.Timestamp,
 				ExcessBlobGas: &excessBlobGas,
 			}
-			excessBlobGas = eip4844.CalcExcessBlobGas(chainConfig, parent, header)
+			excessBlobGas = eip4844.CalcExcessBlobGas(chainConfig, parent, header.Time)
 			vmContext.BlobBaseFee = eip4844.CalcBlobFee(chainConfig, header)
 		}
 	}

consensus/misc/eip4844/eip4844.go

@@ -34,6 +34,9 @@ var (
 // if the current block contains no transactions, the excessBlobGas is updated
 // accordingly.
 func VerifyEIP4844Header(config *params.ChainConfig, parent, header *types.Header) error {
+	if header.Number.Uint64() != parent.Number.Uint64()+1 {
+		panic("bad header pair")
+	}
 	// Verify the header is not malformed
 	if header.ExcessBlobGas == nil {
 		return errors.New("header is missing excessBlobGas")
@@ -50,7 +53,7 @@ func VerifyEIP4844Header(config *params.ChainConfig, parent, header *types.Heade
 		return fmt.Errorf("blob gas used %d not a multiple of blob gas per blob %d", header.BlobGasUsed, params.BlobTxBlobGasPerBlob)
 	}
 	// Verify the excessBlobGas is correct based on the parent header
-	expectedExcessBlobGas := CalcExcessBlobGas(config, parent, header)
+	expectedExcessBlobGas := CalcExcessBlobGas(config, parent, header.Time)
 	if *header.ExcessBlobGas != expectedExcessBlobGas {
 		return fmt.Errorf("invalid excessBlobGas: have %d, want %d", *header.ExcessBlobGas, expectedExcessBlobGas)
 	}
@@ -59,9 +62,8 @@ func VerifyEIP4844Header(config *params.ChainConfig, parent, header *types.Heade
 
 // CalcExcessBlobGas calculates the excess blob gas after applying the set of
 // blobs on top of the excess blob gas.
-func CalcExcessBlobGas(config *params.ChainConfig, parent, header *types.Header) uint64 {
+func CalcExcessBlobGas(config *params.ChainConfig, parent *types.Header, headTimestamp uint64) uint64 {
 	var (
-		targetGas           = uint64(targetBlobsPerBlock(config, header.Time)) * params.BlobTxBlobGasPerBlob
 		parentExcessBlobGas uint64
 		parentBlobGasUsed   uint64
 	)
@@ -70,6 +72,7 @@ func CalcExcessBlobGas(config *params.ChainConfig, parent, header *types.Header)
 		parentBlobGasUsed = *parent.BlobGasUsed
 	}
 	excessBlobGas := parentExcessBlobGas + parentBlobGasUsed
+	targetGas := uint64(targetBlobsPerBlock(config, headTimestamp)) * params.BlobTxBlobGasPerBlob
 	if excessBlobGas < targetGas {
 		return 0
 	}

consensus/misc/eip4844/eip4844_test.go

@@ -57,15 +57,11 @@ func TestCalcExcessBlobGas(t *testing.T) {
 	}
 	for i, tt := range tests {
 		blobGasUsed := uint64(tt.blobs) * params.BlobTxBlobGasPerBlob
-		head := &types.Header{
-			Time: *config.CancunTime,
-		}
-		parent := &types.Header{
-			Time:          *config.CancunTime,
+		header := &types.Header{
 			ExcessBlobGas: &tt.excess,
 			BlobGasUsed:   &blobGasUsed,
 		}
-		result := CalcExcessBlobGas(config, parent, head)
+		result := CalcExcessBlobGas(config, header, *config.CancunTime)
 		if result != tt.want {
 			t.Errorf("test %d: excess blob gas mismatch: have %v, want %v", i, result, tt.want)
 		}

core/chain_makers.go

@@ -582,25 +582,26 @@ func GenerateVerkleChainWithGenesis(genesis *Genesis, engine consensus.Engine, n
 
 func (cm *chainMaker) makeHeader(parent *types.Block, state *state.StateDB, engine consensus.Engine) *types.Header {
 	time := parent.Time() + 10 // block time is fixed at 10 seconds
+	parentHeader := parent.Header()
 	header := &types.Header{
 		Root:       state.IntermediateRoot(cm.config.IsEIP158(parent.Number())),
 		ParentHash: parent.Hash(),
 		Coinbase:   parent.Coinbase(),
-		Difficulty: engine.CalcDifficulty(cm, time, parent.Header()),
+		Difficulty: engine.CalcDifficulty(cm, time, parentHeader),
 		GasLimit:   parent.GasLimit(),
 		Number:     new(big.Int).Add(parent.Number(), common.Big1),
 		Time:       time,
 	}
 
 	if cm.config.IsLondon(header.Number) {
-		header.BaseFee = eip1559.CalcBaseFee(cm.config, parent.Header())
+		header.BaseFee = eip1559.CalcBaseFee(cm.config, parentHeader)
 		if !cm.config.IsLondon(parent.Number()) {
 			parentGasLimit := parent.GasLimit() * cm.config.ElasticityMultiplier()
 			header.GasLimit = CalcGasLimit(parentGasLimit, parentGasLimit)
 		}
 	}
 	if cm.config.IsCancun(header.Number, header.Time) {
-		excessBlobGas := eip4844.CalcExcessBlobGas(cm.config, parent.Header(), header)
+		excessBlobGas := eip4844.CalcExcessBlobGas(cm.config, parentHeader, time)
 		header.ExcessBlobGas = &excessBlobGas
 		header.BlobGasUsed = new(uint64)
 		header.ParentBeaconRoot = new(common.Hash)

core/state_processor_test.go

@@ -407,7 +407,7 @@ func GenerateBadBlock(parent *types.Block, engine consensus.Engine, txs types.Tr
 	}
 	header.Root = common.BytesToHash(hasher.Sum(nil))
 	if config.IsCancun(header.Number, header.Time) {
-		excess := eip4844.CalcExcessBlobGas(config, parent.Header(), header)
+		excess := eip4844.CalcExcessBlobGas(config, parent.Header(), header.Time)
 		used := uint64(nBlobs * params.BlobTxBlobGasPerBlob)
 		header.ExcessBlobGas = &excess
 		header.BlobGasUsed = &used

eth/gasprice/feehistory.go

@@ -97,7 +97,7 @@ func (oracle *Oracle) processBlock(bf *blockFees, percentiles []float64) {
 	// Fill in blob base fee and next blob base fee.
 	if excessBlobGas := bf.header.ExcessBlobGas; excessBlobGas != nil {
 		bf.results.blobBaseFee = eip4844.CalcBlobFee(config, bf.header)
-		excess := eip4844.CalcExcessBlobGas(config, bf.header, bf.header)
+		excess := eip4844.CalcExcessBlobGas(config, bf.header, bf.header.Time)
 		next := &types.Header{Number: bf.header.Number, Time: bf.header.Time, ExcessBlobGas: &excess}
 		bf.results.nextBlobBaseFee = eip4844.CalcBlobFee(config, next)
 	} else {

eth/tracers/internal/tracetest/util.go

@@ -55,7 +55,7 @@ func (c *callContext) toBlockContext(genesis *core.Genesis) vm.BlockContext {
 
 	if genesis.ExcessBlobGas != nil && genesis.BlobGasUsed != nil {
 		header := &types.Header{Number: genesis.Config.LondonBlock, Time: *genesis.Config.CancunTime}
-		excess := eip4844.CalcExcessBlobGas(genesis.Config, header, genesis.ToBlock().Header())
+		excess := eip4844.CalcExcessBlobGas(genesis.Config, header, genesis.Timestamp)
 		header.ExcessBlobGas = &excess
 		context.BlobBaseFee = eip4844.CalcBlobFee(genesis.Config, header)
 	}

internal/ethapi/simulate.go

@@ -159,7 +159,7 @@ func (sim *simulator) processBlock(ctx context.Context, block *simBlock, header,
 	if sim.chainConfig.IsCancun(header.Number, header.Time) {
 		var excess uint64
 		if sim.chainConfig.IsCancun(parent.Number, parent.Time) {
-			excess = eip4844.CalcExcessBlobGas(sim.chainConfig, parent, header)
+			excess = eip4844.CalcExcessBlobGas(sim.chainConfig, parent, header.Time)
 		}
 		header.ExcessBlobGas = &excess
 	}

miner/worker.go

@@ -210,7 +210,7 @@ func (miner *Miner) prepareWork(genParams *generateParams, witness bool) (*envir
 	if miner.chainConfig.IsCancun(header.Number, header.Time) {
 		var excessBlobGas uint64
 		if miner.chainConfig.IsCancun(parent.Number, parent.Time) {
-			excessBlobGas = eip4844.CalcExcessBlobGas(miner.chainConfig, parent, header)
+			excessBlobGas = eip4844.CalcExcessBlobGas(miner.chainConfig, parent, timestamp)
 		}
 		header.BlobGasUsed = new(uint64)
 		header.ExcessBlobGas = &excessBlobGas