cmd/evm ignores the baseFeePerGas setting in genesis.json when executing opcode BASEFEE

[Alleysira]

System information

Geth version: evm version 1.14.5-stable-0dd173a7 and evm version 1.14.8-unstable-978041fe
CL client & version: Nope
OS & Version: Ubuntu 20.04
Commit hash : Nope

Expected behaviour

Hello developers,

I'm currently testing EVM implementations and have encountered a peculiar issue. When executing the BASEFEE opcode (0x48), evm will return 0x3b9aca00(1000000000) instead of the value provided in genesis.json .

Steps to reproduce the behaviour

I used the latest version of geth image pulled from dockerhub(digest bb0eb0bd6) to reproduce this bug.

docker pull ethereum/client-go:alltools-latest
docker run ethereum/client-go:alltools-latest tail -f /dev/null
docker exec -it containerid /bin/sh

This is the genesis.json file for --prestate, which sets the baseFee to 0xffff.

{
  "config": {
    "chainId": 9599,
    "homesteadBlock": 0,
    "eip150Block": 0,
    "eip155Block": 0,
    "eip158Block": 0,
    "byzantiumBlock": 0,
    "constantinopleBlock": 0,
    "petersburgBlock": 0,
    "istanbulBlock": 0,
    "berlinBlock": 0,
    "londonBlock": 0,
    "shanghaiBlock": 0,
    "shanghaiTime":0
  },
  "alloc": {
    "0x1c7cd2d37ffd63856a5bd56a9af1643f2bcf545f": {
     "balance": "0x1234"
    }
  },
  "coinbase": "0x000000000000000000000000000000000000abcd",
  "difficulty": "0x0",
  "extraData": "",
  "gasLimit": "0xffffff",
  "nonce": "0x0000000000000042",
  "mixhash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "parentHash": "0x0000000000000000000000000000000000000000000000000000000000000000",
  "timestamp": "0x00",
  "baseFeePerGas": "0xffff"
}

Use evm to run the bytecode 4860005260406000f3 .

evm --debug --gas 0xffffff --nomemory=false --json --code 4860005260406000f3 --prestate ./genesis.json run

The mnemonics of the bytecode are as follows.

BASEFEE
PUSH1 00
MSTORE
PUSH1 40
PUSH1 00
RETURN 

The result from evm's output, the stack output of BASEFEE is 0x3b9aca00.

{"pc":0,"op":72,"gas":"0xffffff","gasCost":"0x2","memSize":0,"stack":[],"depth":1,"refund":0,"opName":"BASEFEE"}
{"pc":1,"op":96,"gas":"0xfffffd","gasCost":"0x3","memSize":0,"stack":["0x3b9aca00"],"depth":1,"refund":0,"opName":"PUSH1"}
{"pc":3,"op":82,"gas":"0xfffffa","gasCost":"0x6","memSize":0,"stack":["0x3b9aca00","0x0"],"depth":1,"refund":0,"opName":"MSTORE"}
{"pc":4,"op":96,"gas":"0xfffff4","gasCost":"0x3","memory":"0x000000000000000000000000000000000000000000000000000000003b9aca00","memSize":32,"stack":[],"depth":1,"refund":0,"opName":"PUSH1"}
{"pc":6,"op":96,"gas":"0xfffff1","gasCost":"0x3","memory":"0x000000000000000000000000000000000000000000000000000000003b9aca00","memSize":32,"stack":["0x40"],"depth":1,"refund":0,"opName":"PUSH1"}
{"pc":8,"op":243,"gas":"0xffffee","gasCost":"0x3","memory":"0x000000000000000000000000000000000000000000000000000000003b9aca00","memSize":32,"stack":["0x40","0x0"],"depth":1,"refund":0,"opName":"RETURN"}
{"output":"000000000000000000000000000000000000000000000000000000003b9aca000000000000000000000000000000000000000000000000000000000000000000","gasUsed":"0x14"}

Backtrace

I checked in evm version 1.14.8-unstable-978041fe and evm version 1.14.5-stable-0dd173a7, the problem occured in both versions.

It seems that the baseFeePerGas in genesis.json is just ignored.

go-ethereum/cmd/evm/runner.go

Lines 214 to 228 in b37ac5c

	runtimeConfig := runtime.Config{
	Origin: sender,
	State: statedb,
	GasLimit: initialGas,
	GasPrice: flags.GlobalBig(ctx, PriceFlag.Name),
	Value: flags.GlobalBig(ctx, ValueFlag.Name),
	Difficulty: genesisConfig.Difficulty,
	Time: genesisConfig.Timestamp,
	Coinbase: genesisConfig.Coinbase,
	BlockNumber: new(big.Int).SetUint64(genesisConfig.Number),
	BlobHashes: blobHashes,
	BlobBaseFee: blobBaseFee,
	EVMConfig: vm.Config{
	Tracer: tracer,
	},

Thanks for your time!

[holiman]

Thanks for providing a detailed "how to repro"!