bsc/core/vm/gas_table.go
Felix Lange b628d72766
build: upgrade to go 1.19 (#25726)
This changes the CI / release builds to use the latest Go version. It also
upgrades golangci-lint to a newer version compatible with Go 1.19.

In Go 1.19, godoc has gained official support for links and lists. The
syntax for code blocks in doc comments has changed and now requires a
leading tab character. gofmt adapts comments to the new syntax
automatically, so there are a lot of comment re-formatting changes in this
PR. We need to apply the new format in order to pass the CI lint stage with
Go 1.19.

With the linter upgrade, I have decided to disable 'gosec' - it produces
too many false-positive warnings. The 'deadcode' and 'varcheck' linters
have also been removed because golangci-lint warns about them being
unmaintained. 'unused' provides similar coverage and we already have it
enabled, so we don't lose much with this change.
2022-09-10 13:25:40 +02:00

445 lines
16 KiB
Go

// Copyright 2017 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 (
"errors"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/math"
"github.com/ethereum/go-ethereum/params"
)
// memoryGasCost calculates the quadratic gas for memory expansion. It does so
// only for the memory region that is expanded, not the total memory.
func memoryGasCost(mem *Memory, newMemSize uint64) (uint64, error) {
if newMemSize == 0 {
return 0, nil
}
// The maximum that will fit in a uint64 is max_word_count - 1. Anything above
// that will result in an overflow. Additionally, a newMemSize which results in
// a newMemSizeWords larger than 0xFFFFFFFF will cause the square operation to
// overflow. The constant 0x1FFFFFFFE0 is the highest number that can be used
// without overflowing the gas calculation.
if newMemSize > 0x1FFFFFFFE0 {
return 0, ErrGasUintOverflow
}
newMemSizeWords := toWordSize(newMemSize)
newMemSize = newMemSizeWords * 32
if newMemSize > uint64(mem.Len()) {
square := newMemSizeWords * newMemSizeWords
linCoef := newMemSizeWords * params.MemoryGas
quadCoef := square / params.QuadCoeffDiv
newTotalFee := linCoef + quadCoef
fee := newTotalFee - mem.lastGasCost
mem.lastGasCost = newTotalFee
return fee, nil
}
return 0, nil
}
// memoryCopierGas creates the gas functions for the following opcodes, and takes
// the stack position of the operand which determines the size of the data to copy
// as argument:
// CALLDATACOPY (stack position 2)
// CODECOPY (stack position 2)
// EXTCODECOPY (stack position 3)
// RETURNDATACOPY (stack position 2)
func memoryCopierGas(stackpos int) gasFunc {
return func(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
// Gas for expanding the memory
gas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
// And gas for copying data, charged per word at param.CopyGas
words, overflow := stack.Back(stackpos).Uint64WithOverflow()
if overflow {
return 0, ErrGasUintOverflow
}
if words, overflow = math.SafeMul(toWordSize(words), params.CopyGas); overflow {
return 0, ErrGasUintOverflow
}
if gas, overflow = math.SafeAdd(gas, words); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
}
var (
gasCallDataCopy = memoryCopierGas(2)
gasCodeCopy = memoryCopierGas(2)
gasExtCodeCopy = memoryCopierGas(3)
gasReturnDataCopy = memoryCopierGas(2)
)
func gasSStore(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
var (
y, x = stack.Back(1), stack.Back(0)
current = evm.StateDB.GetState(contract.Address(), x.Bytes32())
)
// The legacy gas metering only takes into consideration the current state
// Legacy rules should be applied if we are in Petersburg (removal of EIP-1283)
// OR Constantinople is not active
if evm.chainRules.IsPetersburg || !evm.chainRules.IsConstantinople {
// This checks for 3 scenario's and calculates gas accordingly:
//
// 1. From a zero-value address to a non-zero value (NEW VALUE)
// 2. From a non-zero value address to a zero-value address (DELETE)
// 3. From a non-zero to a non-zero (CHANGE)
switch {
case current == (common.Hash{}) && y.Sign() != 0: // 0 => non 0
return params.SstoreSetGas, nil
case current != (common.Hash{}) && y.Sign() == 0: // non 0 => 0
evm.StateDB.AddRefund(params.SstoreRefundGas)
return params.SstoreClearGas, nil
default: // non 0 => non 0 (or 0 => 0)
return params.SstoreResetGas, nil
}
}
// The new gas metering is based on net gas costs (EIP-1283):
//
// (1.) If current value equals new value (this is a no-op), 200 gas is deducted.
// (2.) If current value does not equal new value
// (2.1.) If original value equals current value (this storage slot has not been changed by the current execution context)
// (2.1.1.) If original value is 0, 20000 gas is deducted.
// (2.1.2.) Otherwise, 5000 gas is deducted. If new value is 0, add 15000 gas to refund counter.
// (2.2.) If original value does not equal current value (this storage slot is dirty), 200 gas is deducted. Apply both of the following clauses.
// (2.2.1.) If original value is not 0
// (2.2.1.1.) If current value is 0 (also means that new value is not 0), remove 15000 gas from refund counter. We can prove that refund counter will never go below 0.
// (2.2.1.2.) If new value is 0 (also means that current value is not 0), add 15000 gas to refund counter.
// (2.2.2.) If original value equals new value (this storage slot is reset)
// (2.2.2.1.) If original value is 0, add 19800 gas to refund counter.
// (2.2.2.2.) Otherwise, add 4800 gas to refund counter.
value := common.Hash(y.Bytes32())
if current == value { // noop (1)
return params.NetSstoreNoopGas, nil
}
original := evm.StateDB.GetCommittedState(contract.Address(), x.Bytes32())
if original == current {
if original == (common.Hash{}) { // create slot (2.1.1)
return params.NetSstoreInitGas, nil
}
if value == (common.Hash{}) { // delete slot (2.1.2b)
evm.StateDB.AddRefund(params.NetSstoreClearRefund)
}
return params.NetSstoreCleanGas, nil // write existing slot (2.1.2)
}
if original != (common.Hash{}) {
if current == (common.Hash{}) { // recreate slot (2.2.1.1)
evm.StateDB.SubRefund(params.NetSstoreClearRefund)
} else if value == (common.Hash{}) { // delete slot (2.2.1.2)
evm.StateDB.AddRefund(params.NetSstoreClearRefund)
}
}
if original == value {
if original == (common.Hash{}) { // reset to original inexistent slot (2.2.2.1)
evm.StateDB.AddRefund(params.NetSstoreResetClearRefund)
} else { // reset to original existing slot (2.2.2.2)
evm.StateDB.AddRefund(params.NetSstoreResetRefund)
}
}
return params.NetSstoreDirtyGas, nil
}
// Here come the EIP220 rules:
//
// (0.) If *gasleft* is less than or equal to 2300, fail the current call.
// (1.) If current value equals new value (this is a no-op), SLOAD_GAS is deducted.
// (2.) If current value does not equal new value:
// (2.1.) If original value equals current value (this storage slot has not been changed by the current execution context):
// (2.1.1.) If original value is 0, SSTORE_SET_GAS (20K) gas is deducted.
// (2.1.2.) Otherwise, SSTORE_RESET_GAS gas is deducted. If new value is 0, add SSTORE_CLEARS_SCHEDULE to refund counter.
// (2.2.) If original value does not equal current value (this storage slot is dirty), SLOAD_GAS gas is deducted. Apply both of the following clauses:
// (2.2.1.) If original value is not 0:
// (2.2.1.1.) If current value is 0 (also means that new value is not 0), subtract SSTORE_CLEARS_SCHEDULE gas from refund counter.
// (2.2.1.2.) If new value is 0 (also means that current value is not 0), add SSTORE_CLEARS_SCHEDULE gas to refund counter.
// (2.2.2.) If original value equals new value (this storage slot is reset):
// (2.2.2.1.) If original value is 0, add SSTORE_SET_GAS - SLOAD_GAS to refund counter.
// (2.2.2.2.) Otherwise, add SSTORE_RESET_GAS - SLOAD_GAS gas to refund counter.
func gasSStoreEIP2200(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
// If we fail the minimum gas availability invariant, fail (0)
if contract.Gas <= params.SstoreSentryGasEIP2200 {
return 0, errors.New("not enough gas for reentrancy sentry")
}
// Gas sentry honoured, do the actual gas calculation based on the stored value
var (
y, x = stack.Back(1), stack.Back(0)
current = evm.StateDB.GetState(contract.Address(), x.Bytes32())
)
value := common.Hash(y.Bytes32())
if current == value { // noop (1)
return params.SloadGasEIP2200, nil
}
original := evm.StateDB.GetCommittedState(contract.Address(), x.Bytes32())
if original == current {
if original == (common.Hash{}) { // create slot (2.1.1)
return params.SstoreSetGasEIP2200, nil
}
if value == (common.Hash{}) { // delete slot (2.1.2b)
evm.StateDB.AddRefund(params.SstoreClearsScheduleRefundEIP2200)
}
return params.SstoreResetGasEIP2200, nil // write existing slot (2.1.2)
}
if original != (common.Hash{}) {
if current == (common.Hash{}) { // recreate slot (2.2.1.1)
evm.StateDB.SubRefund(params.SstoreClearsScheduleRefundEIP2200)
} else if value == (common.Hash{}) { // delete slot (2.2.1.2)
evm.StateDB.AddRefund(params.SstoreClearsScheduleRefundEIP2200)
}
}
if original == value {
if original == (common.Hash{}) { // reset to original inexistent slot (2.2.2.1)
evm.StateDB.AddRefund(params.SstoreSetGasEIP2200 - params.SloadGasEIP2200)
} else { // reset to original existing slot (2.2.2.2)
evm.StateDB.AddRefund(params.SstoreResetGasEIP2200 - params.SloadGasEIP2200)
}
}
return params.SloadGasEIP2200, nil // dirty update (2.2)
}
func makeGasLog(n uint64) gasFunc {
return func(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
requestedSize, overflow := stack.Back(1).Uint64WithOverflow()
if overflow {
return 0, ErrGasUintOverflow
}
gas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
if gas, overflow = math.SafeAdd(gas, params.LogGas); overflow {
return 0, ErrGasUintOverflow
}
if gas, overflow = math.SafeAdd(gas, n*params.LogTopicGas); overflow {
return 0, ErrGasUintOverflow
}
var memorySizeGas uint64
if memorySizeGas, overflow = math.SafeMul(requestedSize, params.LogDataGas); overflow {
return 0, ErrGasUintOverflow
}
if gas, overflow = math.SafeAdd(gas, memorySizeGas); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
}
func gasKeccak256(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
gas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
wordGas, overflow := stack.Back(1).Uint64WithOverflow()
if overflow {
return 0, ErrGasUintOverflow
}
if wordGas, overflow = math.SafeMul(toWordSize(wordGas), params.Keccak256WordGas); overflow {
return 0, ErrGasUintOverflow
}
if gas, overflow = math.SafeAdd(gas, wordGas); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
// pureMemoryGascost is used by several operations, which aside from their
// static cost have a dynamic cost which is solely based on the memory
// expansion
func pureMemoryGascost(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
return memoryGasCost(mem, memorySize)
}
var (
gasReturn = pureMemoryGascost
gasRevert = pureMemoryGascost
gasMLoad = pureMemoryGascost
gasMStore8 = pureMemoryGascost
gasMStore = pureMemoryGascost
gasCreate = pureMemoryGascost
)
func gasCreate2(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
gas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
wordGas, overflow := stack.Back(2).Uint64WithOverflow()
if overflow {
return 0, ErrGasUintOverflow
}
if wordGas, overflow = math.SafeMul(toWordSize(wordGas), params.Keccak256WordGas); overflow {
return 0, ErrGasUintOverflow
}
if gas, overflow = math.SafeAdd(gas, wordGas); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
func gasExpFrontier(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
expByteLen := uint64((stack.data[stack.len()-2].BitLen() + 7) / 8)
var (
gas = expByteLen * params.ExpByteFrontier // no overflow check required. Max is 256 * ExpByte gas
overflow bool
)
if gas, overflow = math.SafeAdd(gas, params.ExpGas); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
func gasExpEIP158(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
expByteLen := uint64((stack.data[stack.len()-2].BitLen() + 7) / 8)
var (
gas = expByteLen * params.ExpByteEIP158 // no overflow check required. Max is 256 * ExpByte gas
overflow bool
)
if gas, overflow = math.SafeAdd(gas, params.ExpGas); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
func gasCall(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
var (
gas uint64
transfersValue = !stack.Back(2).IsZero()
address = common.Address(stack.Back(1).Bytes20())
)
if evm.chainRules.IsEIP158 {
if transfersValue && evm.StateDB.Empty(address) {
gas += params.CallNewAccountGas
}
} else if !evm.StateDB.Exist(address) {
gas += params.CallNewAccountGas
}
if transfersValue {
gas += params.CallValueTransferGas
}
memoryGas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
var overflow bool
if gas, overflow = math.SafeAdd(gas, memoryGas); overflow {
return 0, ErrGasUintOverflow
}
evm.callGasTemp, err = callGas(evm.chainRules.IsEIP150, contract.Gas, gas, stack.Back(0))
if err != nil {
return 0, err
}
if gas, overflow = math.SafeAdd(gas, evm.callGasTemp); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
func gasCallCode(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
memoryGas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
var (
gas uint64
overflow bool
)
if stack.Back(2).Sign() != 0 {
gas += params.CallValueTransferGas
}
if gas, overflow = math.SafeAdd(gas, memoryGas); overflow {
return 0, ErrGasUintOverflow
}
evm.callGasTemp, err = callGas(evm.chainRules.IsEIP150, contract.Gas, gas, stack.Back(0))
if err != nil {
return 0, err
}
if gas, overflow = math.SafeAdd(gas, evm.callGasTemp); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
func gasDelegateCall(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
gas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
evm.callGasTemp, err = callGas(evm.chainRules.IsEIP150, contract.Gas, gas, stack.Back(0))
if err != nil {
return 0, err
}
var overflow bool
if gas, overflow = math.SafeAdd(gas, evm.callGasTemp); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
func gasStaticCall(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
gas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
evm.callGasTemp, err = callGas(evm.chainRules.IsEIP150, contract.Gas, gas, stack.Back(0))
if err != nil {
return 0, err
}
var overflow bool
if gas, overflow = math.SafeAdd(gas, evm.callGasTemp); overflow {
return 0, ErrGasUintOverflow
}
return gas, nil
}
func gasSelfdestruct(evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
var gas uint64
// EIP150 homestead gas reprice fork:
if evm.chainRules.IsEIP150 {
gas = params.SelfdestructGasEIP150
var address = common.Address(stack.Back(0).Bytes20())
if evm.chainRules.IsEIP158 {
// if empty and transfers value
if evm.StateDB.Empty(address) && evm.StateDB.GetBalance(contract.Address()).Sign() != 0 {
gas += params.CreateBySelfdestructGas
}
} else if !evm.StateDB.Exist(address) {
gas += params.CreateBySelfdestructGas
}
}
if !evm.StateDB.HasSuicided(contract.Address()) {
evm.StateDB.AddRefund(params.SelfdestructRefundGas)
}
return gas, nil
}