From b02fe5317f54efae7309d9a8fc76aaad68e639e4 Mon Sep 17 00:00:00 2001
From: Andrei Maiboroda <andrei@ethereum.org>
Date: Fri, 3 Dec 2021 11:10:26 +0100
Subject: [PATCH] core/vm: move interpreter interruption check to jump
 instructions (#24026)

* core/vm: Remove interpreter loop interruption check

* core/vm: Unit test for interpreter loop interruption

* core/vm: Check for interpreter loop abort on every jump
---
 core/vm/instructions.go     |  8 ++++
 core/vm/interpreter.go      |  6 ---
 core/vm/interpreter_test.go | 77 +++++++++++++++++++++++++++++++++++++
 3 files changed, 85 insertions(+), 6 deletions(-)
 create mode 100644 core/vm/interpreter_test.go

diff --git a/core/vm/instructions.go b/core/vm/instructions.go
index 1e91ff255..4eda3bf53 100644
--- a/core/vm/instructions.go
+++ b/core/vm/instructions.go
@@ -17,6 +17,8 @@
 package vm
 
 import (
+	"sync/atomic"
+
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/params"
@@ -525,6 +527,9 @@ func opSstore(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]b
 }
 
 func opJump(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
+	if atomic.LoadInt32(&interpreter.evm.abort) != 0 {
+		return nil, errStopToken
+	}
 	pos := scope.Stack.pop()
 	if !scope.Contract.validJumpdest(&pos) {
 		return nil, ErrInvalidJump
@@ -534,6 +539,9 @@ func opJump(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byt
 }
 
 func opJumpi(pc *uint64, interpreter *EVMInterpreter, scope *ScopeContext) ([]byte, error) {
+	if atomic.LoadInt32(&interpreter.evm.abort) != 0 {
+		return nil, errStopToken
+	}
 	pos, cond := scope.Stack.pop(), scope.Stack.pop()
 	if !cond.IsZero() {
 		if !scope.Contract.validJumpdest(&pos) {
diff --git a/core/vm/interpreter.go b/core/vm/interpreter.go
index a4c54b1fb..673f046a4 100644
--- a/core/vm/interpreter.go
+++ b/core/vm/interpreter.go
@@ -18,7 +18,6 @@ package vm
 
 import (
 	"hash"
-	"sync/atomic"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/math"
@@ -178,12 +177,7 @@ func (in *EVMInterpreter) Run(contract *Contract, input []byte, readOnly bool) (
 	// explicit STOP, RETURN or SELFDESTRUCT is executed, an error occurred during
 	// the execution of one of the operations or until the done flag is set by the
 	// parent context.
-	steps := 0
 	for {
-		steps++
-		if steps%1000 == 0 && atomic.LoadInt32(&in.evm.abort) != 0 {
-			break
-		}
 		if in.cfg.Debug {
 			// Capture pre-execution values for tracing.
 			logged, pcCopy, gasCopy = false, pc, contract.Gas
diff --git a/core/vm/interpreter_test.go b/core/vm/interpreter_test.go
new file mode 100644
index 000000000..dfae0f2e2
--- /dev/null
+++ b/core/vm/interpreter_test.go
@@ -0,0 +1,77 @@
+// Copyright 2021 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 vm
+
+import (
+	"math/big"
+	"testing"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/common/math"
+	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/state"
+	"github.com/ethereum/go-ethereum/params"
+)
+
+var loopInterruptTests = []string{
+	// infinite loop using JUMP: push(2) jumpdest dup1 jump
+	"60025b8056",
+	// infinite loop using JUMPI: push(1) push(4) jumpdest dup2 dup2 jumpi
+	"600160045b818157",
+}
+
+func TestLoopInterrupt(t *testing.T) {
+	address := common.BytesToAddress([]byte("contract"))
+	vmctx := BlockContext{
+		Transfer: func(StateDB, common.Address, common.Address, *big.Int) {},
+	}
+
+	for i, tt := range loopInterruptTests {
+		statedb, _ := state.New(common.Hash{}, state.NewDatabase(rawdb.NewMemoryDatabase()), nil)
+		statedb.CreateAccount(address)
+		statedb.SetCode(address, common.Hex2Bytes(tt))
+		statedb.Finalise(true)
+
+		evm := NewEVM(vmctx, TxContext{}, statedb, params.AllEthashProtocolChanges, Config{})
+
+		errChannel := make(chan error)
+		timeout := make(chan bool)
+
+		go func(evm *EVM) {
+			_, _, err := evm.Call(AccountRef(common.Address{}), address, nil, math.MaxUint64, new(big.Int))
+			errChannel <- err
+		}(evm)
+
+		go func() {
+			<-time.After(time.Second)
+			timeout <- true
+		}()
+
+		evm.Cancel()
+
+		select {
+		case <-timeout:
+			t.Errorf("test %d timed out", i)
+		case err := <-errChannel:
+			if err != nil {
+				t.Errorf("test %d failure: %v", i, err)
+			}
+		}
+	}
+
+}