core: prevent block level tracers from crashing the node

core/blockchain.go

@@ -412,7 +412,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, genesis *Genesis
 	bc.engine.VerifyHeader(bc, bc.CurrentHeader())
 
 	if bc.logger != nil && bc.logger.OnBlockchainInit != nil {
-		bc.logger.OnBlockchainInit(chainConfig)
+		bc.guardedOnBlockchainInit(chainConfig)
 	}
 	if bc.logger != nil && bc.logger.OnGenesisBlock != nil {
 		if block := bc.CurrentBlock(); block.Number.Uint64() == 0 {
@@ -423,7 +423,7 @@ func NewBlockChain(db ethdb.Database, cacheConfig *CacheConfig, genesis *Genesis
 			if alloc == nil {
 				return nil, errors.New("live blockchain tracer requires genesis alloc to be set")
 			}
-			bc.logger.OnGenesisBlock(bc.genesisBlock, alloc)
+			bc.guardedOnGenesisBlock(bc.genesisBlock, alloc)
 		}
 	}
 
@@ -1155,7 +1155,7 @@ func (bc *BlockChain) Stop() {
 	}
 	// Allow tracers to clean-up and release resources.
 	if bc.logger != nil && bc.logger.OnClose != nil {
-		bc.logger.OnClose()
+		bc.guardedOnClose()
 	}
 	// Close the trie database, release all the held resources as the last step.
 	if err := bc.triedb.Close(); err != nil {
@@ -1752,7 +1752,7 @@ func (bc *BlockChain) insertChain(chain types.Blocks, setHead bool, makeWitness
 			}
 			stats.processed++
 			if bc.logger != nil && bc.logger.OnSkippedBlock != nil {
-				bc.logger.OnSkippedBlock(tracing.BlockEvent{
+				bc.guardedOnSkippedBlock(tracing.BlockEvent{
 					Block:     block,
 					TD:        bc.GetTd(block.ParentHash(), block.NumberU64()-1),
 					Finalized: bc.CurrentFinalBlock(),
@@ -1879,18 +1879,15 @@ type blockProcessingResult struct {
 // it writes the block and associated state to database.
 func (bc *BlockChain) processBlock(block *types.Block, statedb *state.StateDB, start time.Time, setHead bool) (_ *blockProcessingResult, blockEndErr error) {
 	if bc.logger != nil && bc.logger.OnBlockStart != nil {
-		td := bc.GetTd(block.ParentHash(), block.NumberU64()-1)
-		bc.logger.OnBlockStart(tracing.BlockEvent{
+		bc.guardedOnBlockStart(tracing.BlockEvent{
 			Block:     block,
-			TD:        td,
+			TD:        bc.GetTd(block.ParentHash(), block.NumberU64()-1),
 			Finalized: bc.CurrentFinalBlock(),
 			Safe:      bc.CurrentSafeBlock(),
 		})
 	}
 	if bc.logger != nil && bc.logger.OnBlockEnd != nil {
-		defer func() {
-			bc.logger.OnBlockEnd(blockEndErr)
-		}()
+		defer bc.guardedOnBlockEnd(blockEndErr)
 	}
 
 	// Process block using the parent state as reference point

core/blockchain_tracing.go

@@ -0,0 +1,97 @@
+// Copyright 2024 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+// Package core implements the Ethereum consensus protocol.
+package core
+
+import (
+	"github.com/ethereum/go-ethereum/core/tracing"
+	"github.com/ethereum/go-ethereum/core/types"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+// guardedOnGenesisBlock wraps the tracer OnGenesisBlock method with 'recover'. If
+// a panic occurs, the hook will be disabled.
+func (bc *BlockChain) guardedOnGenesisBlock(genesis *types.Block, alloc types.GenesisAlloc) {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Warn("Tracer OnGenesisBlock exited with panic, disabling tracer", "err", err)
+			bc.logger.OnGenesisBlock = nil
+		}
+	}()
+	bc.logger.OnGenesisBlock(genesis, alloc)
+}
+
+// guardedOnBlockchainInit wraps the tracer OnBlockchainInit method with 'recover'. If
+// a panic occurs, the hook will be disabled.
+func (bc *BlockChain) guardedOnBlockchainInit(chainConfig *params.ChainConfig) {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Warn("Tracer OnBlockchainInit exited with panic, disabling tracer", "err", err)
+			bc.logger.OnBlockchainInit = nil
+		}
+	}()
+	bc.logger.OnBlockchainInit(chainConfig)
+}
+
+// guardedOnBlockStart wraps the tracer OnBlockStart method with 'recover'. If
+// a panic occurs, the hook will be disabled.
+func (bc *BlockChain) guardedOnBlockStart(blockEvent tracing.BlockEvent) {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Warn("Tracer OnBlockStart exited with panic, disabling tracer", "err", err)
+			bc.logger.OnBlockStart = nil
+		}
+	}()
+	bc.logger.OnBlockStart(blockEvent)
+}
+
+// guardedOnBlockEnd wraps the tracer OnBlockEnd method with 'recover'. If
+// a panic occurs, the hook will be disabled.
+func (bc *BlockChain) guardedOnBlockEnd(err error) {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Warn("Tracer OnBlockEnd exited with panic, disabling tracer", "err", err)
+			bc.logger.OnBlockEnd = nil
+		}
+	}()
+	bc.logger.OnBlockEnd(err)
+}
+
+// guardedOnClose wraps the tracer OnClose method with 'recover'. If
+// a panic occurs, the hook will be disabled.
+func (bc *BlockChain) guardedOnClose() {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Warn("Tracer OnClose exited with panic, disabling tracer", "err", err)
+			bc.logger.OnClose = nil
+		}
+	}()
+	bc.logger.OnClose()
+}
+
+// guardedOnSkippedBlock wraps the tracer OnSkippedBlock method with 'recover'. If
+// a panic occurs, the hook will be disabled.
+func (bc *BlockChain) guardedOnSkippedBlock(event tracing.BlockEvent) {
+	defer func() {
+		if err := recover(); err != nil {
+			log.Warn("Tracer OnSkippedBlock exited with panic, disabling tracer", "err", err)
+			bc.logger.OnSkippedBlock = nil
+		}
+	}()
+	bc.logger.OnSkippedBlock(event)
+}

eth/tracers/live/crash.go

@@ -0,0 +1,129 @@
+// Copyright 2024 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package live
+
+import (
+	"encoding/json"
+	"math/big"
+
+	"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/eth/tracers"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+func init() {
+	tracers.LiveDirectory.Register("crash", newCrashTracer)
+}
+
+// crash is a no-op live tracer. It's there to
+// catch changes in the tracing interface, as well as
+// for testing live tracing performance. Can be removed
+// as soon as we have a real live tracer.
+type crash struct{}
+
+func newCrashTracer(_ json.RawMessage) (*tracing.Hooks, error) {
+	t := &crash{}
+	return &tracing.Hooks{
+		OnTxStart:        t.OnTxStart,
+		OnTxEnd:          t.OnTxEnd,
+		OnEnter:          t.OnEnter,
+		OnExit:           t.OnExit,
+		OnOpcode:         t.OnOpcode,
+		OnFault:          t.OnFault,
+		OnGasChange:      t.OnGasChange,
+		OnBlockchainInit: t.OnBlockchainInit,
+		OnBlockStart:     t.OnBlockStart,
+		OnBlockEnd:       t.OnBlockEnd,
+		OnSkippedBlock:   t.OnSkippedBlock,
+		OnGenesisBlock:   t.OnGenesisBlock,
+		OnBalanceChange:  t.OnBalanceChange,
+		OnNonceChange:    t.OnNonceChange,
+		OnCodeChange:     t.OnCodeChange,
+		OnStorageChange:  t.OnStorageChange,
+		OnLog:            t.OnLog,
+	}, nil
+}
+
+func (t *crash) OnOpcode(pc uint64, op byte, gas, cost uint64, scope tracing.OpContext, rData []byte, depth int, err error) {
+	panic("OnOpcode")
+}
+
+func (t *crash) OnFault(pc uint64, op byte, gas, cost uint64, _ tracing.OpContext, depth int, err error) {
+	panic("OnFault")
+}
+
+func (t *crash) OnEnter(depth int, typ byte, from common.Address, to common.Address, input []byte, gas uint64, value *big.Int) {
+	panic("OnEnter")
+}
+
+func (t *crash) OnExit(depth int, output []byte, gasUsed uint64, err error, reverted bool) {
+	panic("OnExit")
+}
+
+func (t *crash) OnTxStart(vm *tracing.VMContext, tx *types.Transaction, from common.Address) {
+	panic("OnTxStart")
+}
+
+func (t *crash) OnTxEnd(receipt *types.Receipt, err error) {
+	panic("OnTxEnd")
+}
+
+func (t *crash) OnBlockStart(ev tracing.BlockEvent) {
+	panic("OnBlockStart")
+}
+
+func (t *crash) OnBlockEnd(err error) {
+	panic("OnBlockEnd")
+}
+
+func (t *crash) OnSkippedBlock(ev tracing.BlockEvent) {
+	panic("OnSkippedBlock")
+}
+
+func (t *crash) OnBlockchainInit(chainConfig *params.ChainConfig) {
+	panic("OnBlockchainInit")
+}
+
+func (t *crash) OnGenesisBlock(b *types.Block, alloc types.GenesisAlloc) {
+	panic("OnGenesisBlock")
+}
+
+func (t *crash) OnBalanceChange(a common.Address, prev, new *big.Int, reason tracing.BalanceChangeReason) {
+	panic("OnBalanceChange")
+}
+
+func (t *crash) OnNonceChange(a common.Address, prev, new uint64) {
+	panic("OnNonceChange")
+}
+
+func (t *crash) OnCodeChange(a common.Address, prevCodeHash common.Hash, prev []byte, codeHash common.Hash, code []byte) {
+	panic("OnCodeChange")
+}
+
+func (t *crash) OnStorageChange(a common.Address, k, prev, new common.Hash) {
+	panic("OnStorageChange")
+}
+
+func (t *crash) OnLog(l *types.Log) {
+	panic("OnLog")
+}
+
+func (t *crash) OnGasChange(old, new uint64, reason tracing.GasChangeReason) {
+	panic("OnGasChange")
+}