all: seperate consensus error and evm internal error (#20830)

* all: seperate consensus error and evm internal error

There are actually two types of error will be returned when
a tranaction/message call is executed: (a) consensus error
(b) evm internal error. The former should be converted to
a consensus issue, e.g. The sender doesn't enough asset to
purchase the gas it specifies. The latter is allowed since
evm itself is a blackbox and internal error is allowed to happen.

This PR emphasizes the difference by introducing a executionResult
structure. The evm error is embedded inside. So if any error
returned, it indicates consensus issue happens.

And also this PR improve the `EstimateGas` API to return the concrete
revert reason if the transaction always fails

* all: polish

* accounts/abi/bind/backends: add tests

* accounts/abi/bind/backends, internal: cleanup error message

* all: address comments

* core: fix lint

* accounts, core, eth, internal: address comments

* accounts, internal: resolve revert reason if possible

* accounts, internal: address comments
This commit is contained in:
gary rong
2020-04-22 16:25:36 +08:00
committed by GitHub
parent c60c0c97e7
commit b9df7ecdc3
33 changed files with 550 additions and 238 deletions

View File

@ -17,20 +17,14 @@
package core
import (
"errors"
"math"
"math/big"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/core/vm"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/params"
)
var (
errInsufficientBalanceForGas = errors.New("insufficient balance to pay for gas")
)
/*
The State Transitioning Model
@ -63,7 +57,6 @@ type StateTransition struct {
// Message represents a message sent to a contract.
type Message interface {
From() common.Address
//FromFrontier() (common.Address, error)
To() *common.Address
GasPrice() *big.Int
@ -75,6 +68,41 @@ type Message interface {
Data() []byte
}
// ExecutionResult includes all output after executing given evm
// message no matter the execution itself is successful or not.
type ExecutionResult struct {
UsedGas uint64 // Total used gas but include the refunded gas
Err error // Any error encountered during the execution(listed in core/vm/errors.go)
ReturnData []byte // Returned data from evm(function result or data supplied with revert opcode)
}
// Unwrap returns the internal evm error which allows us for further
// analysis outside.
func (result *ExecutionResult) Unwrap() error {
return result.Err
}
// Failed returns the indicator whether the execution is successful or not
func (result *ExecutionResult) Failed() bool { return result.Err != nil }
// Return is a helper function to help caller distinguish between revert reason
// and function return. Return returns the data after execution if no error occurs.
func (result *ExecutionResult) Return() []byte {
if result.Err != nil {
return nil
}
return common.CopyBytes(result.ReturnData)
}
// Revert returns the concrete revert reason if the execution is aborted by `REVERT`
// opcode. Note the reason can be nil if no data supplied with revert opcode.
func (result *ExecutionResult) Revert() []byte {
if result.Err != vm.ErrExecutionReverted {
return nil
}
return common.CopyBytes(result.ReturnData)
}
// IntrinsicGas computes the 'intrinsic gas' for a message with the given data.
func IntrinsicGas(data []byte, contractCreation, isHomestead bool, isEIP2028 bool) (uint64, error) {
// Set the starting gas for the raw transaction
@ -99,13 +127,13 @@ func IntrinsicGas(data []byte, contractCreation, isHomestead bool, isEIP2028 boo
nonZeroGas = params.TxDataNonZeroGasEIP2028
}
if (math.MaxUint64-gas)/nonZeroGas < nz {
return 0, vm.ErrOutOfGas
return 0, ErrGasUintOverflow
}
gas += nz * nonZeroGas
z := uint64(len(data)) - nz
if (math.MaxUint64-gas)/params.TxDataZeroGas < z {
return 0, vm.ErrOutOfGas
return 0, ErrGasUintOverflow
}
gas += z * params.TxDataZeroGas
}
@ -132,7 +160,7 @@ func NewStateTransition(evm *vm.EVM, msg Message, gp *GasPool) *StateTransition
// the gas used (which includes gas refunds) and an error if it failed. An error always
// indicates a core error meaning that the message would always fail for that particular
// state and would never be accepted within a block.
func ApplyMessage(evm *vm.EVM, msg Message, gp *GasPool) ([]byte, uint64, bool, error) {
func ApplyMessage(evm *vm.EVM, msg Message, gp *GasPool) (*ExecutionResult, error) {
return NewStateTransition(evm, msg, gp).TransitionDb()
}
@ -144,19 +172,10 @@ func (st *StateTransition) to() common.Address {
return *st.msg.To()
}
func (st *StateTransition) useGas(amount uint64) error {
if st.gas < amount {
return vm.ErrOutOfGas
}
st.gas -= amount
return nil
}
func (st *StateTransition) buyGas() error {
mgval := new(big.Int).Mul(new(big.Int).SetUint64(st.msg.Gas()), st.gasPrice)
if st.state.GetBalance(st.msg.From()).Cmp(mgval) < 0 {
return errInsufficientBalanceForGas
return ErrInsufficientFunds
}
if err := st.gp.SubGas(st.msg.Gas()); err != nil {
return err
@ -182,11 +201,32 @@ func (st *StateTransition) preCheck() error {
}
// TransitionDb will transition the state by applying the current message and
// returning the result including the used gas. It returns an error if failed.
// An error indicates a consensus issue.
func (st *StateTransition) TransitionDb() (ret []byte, usedGas uint64, failed bool, err error) {
if err = st.preCheck(); err != nil {
return
// returning the evm execution result with following fields.
//
// - used gas:
// total gas used (including gas being refunded)
// - returndata:
// the returned data from evm
// - concrete execution error:
// various **EVM** error which aborts the execution,
// e.g. ErrOutOfGas, ErrExecutionReverted
//
// However if any consensus issue encountered, return the error directly with
// nil evm execution result.
func (st *StateTransition) TransitionDb() (*ExecutionResult, error) {
// First check this message satisfies all consensus rules before
// applying the message. The rules include these clauses
//
// 1. the nonce of the message caller is correct
// 2. caller has enough balance to cover transaction fee(gaslimit * gasprice)
// 3. the amount of gas required is available in the block
// 4. the purchased gas is enough to cover intrinsic usage
// 5. there is no overflow when calculating intrinsic gas
// 6. caller has enough balance to cover asset transfer for **topmost** call
// Check clauses 1-3, buy gas if everything is correct
if err := st.preCheck(); err != nil {
return nil, err
}
msg := st.msg
sender := vm.AccountRef(msg.From())
@ -194,42 +234,39 @@ func (st *StateTransition) TransitionDb() (ret []byte, usedGas uint64, failed bo
istanbul := st.evm.ChainConfig().IsIstanbul(st.evm.BlockNumber)
contractCreation := msg.To() == nil
// Pay intrinsic gas
// Check clauses 4-5, subtract intrinsic gas if everything is correct
gas, err := IntrinsicGas(st.data, contractCreation, homestead, istanbul)
if err != nil {
return nil, 0, false, err
return nil, err
}
if err = st.useGas(gas); err != nil {
return nil, 0, false, err
if st.gas < gas {
return nil, ErrIntrinsicGas
}
st.gas -= gas
// Check clause 6
if msg.Value().Sign() > 0 && !st.evm.CanTransfer(st.state, msg.From(), msg.Value()) {
return nil, ErrInsufficientFundsForTransfer
}
var (
evm = st.evm
// vm errors do not effect consensus and are therefor
// not assigned to err, except for insufficient balance
// error.
vmerr error
ret []byte
vmerr error // vm errors do not effect consensus and are therefore not assigned to err
)
if contractCreation {
ret, _, st.gas, vmerr = evm.Create(sender, st.data, st.gas, st.value)
ret, _, st.gas, vmerr = st.evm.Create(sender, st.data, st.gas, st.value)
} else {
// Increment the nonce for the next transaction
st.state.SetNonce(msg.From(), st.state.GetNonce(sender.Address())+1)
ret, st.gas, vmerr = evm.Call(sender, st.to(), st.data, st.gas, st.value)
}
if vmerr != nil {
log.Debug("VM returned with error", "err", vmerr)
// The only possible consensus-error would be if there wasn't
// sufficient balance to make the transfer happen. The first
// balance transfer may never fail.
if vmerr == vm.ErrInsufficientBalance {
return nil, 0, false, vmerr
}
ret, st.gas, vmerr = st.evm.Call(sender, st.to(), st.data, st.gas, st.value)
}
st.refundGas()
st.state.AddBalance(st.evm.Coinbase, new(big.Int).Mul(new(big.Int).SetUint64(st.gasUsed()), st.gasPrice))
return ret, st.gasUsed(), vmerr != nil, err
return &ExecutionResult{
UsedGas: st.gasUsed(),
Err: vmerr,
ReturnData: ret,
}, nil
}
func (st *StateTransition) refundGas() {