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Merge pull request #14978 from karalabe/metropolis-staticcall

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core/vm: implement metropolis static call opcode
This commit is contained in:
Péter Szilágyi 2017-08-16 12:39:31 +03:00 committed by GitHub
commit 76069eef38
7 changed files with 168 additions and 22 deletions
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80
core/vm/evm.go
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@ -123,19 +123,20 @@ func (evm *EVM) Cancel() {
atomic.StoreInt32(&evm.abort, 1)
}
// Call executes the contract associated with the addr with the given input as parameters. It also handles any
// necessary value transfer required and takes the necessary steps to create accounts and reverses the state in
// case of an execution error or failed value transfer.
// Call executes the contract associated with the addr with the given input as
// parameters. It also handles any necessary value transfer required and takes
// the necessary steps to create accounts and reverses the state in case of an
// execution error or failed value transfer.
func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil
}
// Depth check execution. Fail if we're trying to execute above the
// limit.
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, ErrDepth
}
// Fail if we're trying to transfer more than the available balance
if !evm.Context.CanTransfer(evm.StateDB, caller.Address(), value) {
return nil, gas, ErrInsufficientBalance
}
@ -173,21 +174,23 @@ func (evm *EVM) Call(caller ContractRef, addr common.Address, input []byte, gas
return ret, contract.Gas, err
}
// CallCode executes the contract associated with the addr with the given input as parameters. It also handles any
// necessary value transfer required and takes the necessary steps to create accounts and reverses the state in
// case of an execution error or failed value transfer.
// CallCode executes the contract associated with the addr with the given input
// as parameters. It also handles any necessary value transfer required and takes
// the necessary steps to create accounts and reverses the state in case of an
// execution error or failed value transfer.
//
// CallCode differs from Call in the sense that it executes the given address' code with the caller as context.
// CallCode differs from Call in the sense that it executes the given address'
// code with the caller as context.
func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte, gas uint64, value *big.Int) (ret []byte, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil
}
// Depth check execution. Fail if we're trying to execute above the
// limit.
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, ErrDepth
}
// Fail if we're trying to transfer more than the available balance
if !evm.CanTransfer(evm.StateDB, caller.Address(), value) {
return nil, gas, ErrInsufficientBalance
}
@ -211,18 +214,16 @@ func (evm *EVM) CallCode(caller ContractRef, addr common.Address, input []byte,
return ret, contract.Gas, err
}
// DelegateCall executes the contract associated with the addr with the given input as parameters.
// It reverses the state in case of an execution error.
// DelegateCall executes the contract associated with the addr with the given input
// as parameters. It reverses the state in case of an execution error.
//
// DelegateCall differs from CallCode in the sense that it executes the given address' code with the caller as context
// and the caller is set to the caller of the caller.
// DelegateCall differs from CallCode in the sense that it executes the given address'
// code with the caller as context and the caller is set to the caller of the caller.
func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil
}
// Depth check execution. Fail if we're trying to execute above the
// limit.
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, ErrDepth
}
@ -232,7 +233,7 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
to = AccountRef(caller.Address())
)
// Iinitialise a new contract and make initialise the delegate values
// Initialise a new contract and make initialise the delegate values
contract := NewContract(caller, to, nil, gas).AsDelegate()
contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
@ -245,6 +246,47 @@ func (evm *EVM) DelegateCall(caller ContractRef, addr common.Address, input []by
return ret, contract.Gas, err
}
// StaticCall executes the contract associated with the addr with the given input
// as parameters while disallowing any modifications to the state during the call.
// Opcodes that attempt to perform such modifications will result in exceptions
// instead of performing the modifications.
func (evm *EVM) StaticCall(caller ContractRef, addr common.Address, input []byte, gas uint64) (ret []byte, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {
return nil, gas, nil
}
// Fail if we're trying to execute above the call depth limit
if evm.depth > int(params.CallCreateDepth) {
return nil, gas, ErrDepth
}
// Make sure the readonly is only set if we aren't in readonly yet
// this makes also sure that the readonly flag isn't removed for
// child calls.
if !evm.interpreter.readonly {
evm.interpreter.readonly = true
defer func() { evm.interpreter.readonly = false }()
}
var (
to = AccountRef(addr)
snapshot = evm.StateDB.Snapshot()
)
// Initialise a new contract and set the code that is to be used by the
// EVM. The contract is a scoped environment for this execution context
// only.
contract := NewContract(caller, to, new(big.Int), gas)
contract.SetCallCode(&addr, evm.StateDB.GetCodeHash(addr), evm.StateDB.GetCode(addr))
// When an error was returned by the EVM or when setting the creation code
// above we revert to the snapshot and consume any gas remaining. Additionally
// when we're in Homestead this also counts for code storage gas errors.
ret, err = run(evm, snapshot, contract, input)
if err != nil {
contract.UseGas(contract.Gas)
evm.StateDB.RevertToSnapshot(snapshot)
}
return ret, contract.Gas, err
}
// Create creates a new contract using code as deployment code.
func (evm *EVM) Create(caller ContractRef, code []byte, gas uint64, value *big.Int) (ret []byte, contractAddr common.Address, leftOverGas uint64, err error) {
if evm.vmConfig.NoRecursion && evm.depth > 0 {

27
core/vm/gas_table.go
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@ -423,6 +423,33 @@ func gasDelegateCall(gt params.GasTable, evm *EVM, contract *Contract, stack *St
return gas, nil
}
func gasStaticCall(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
gas, err := memoryGasCost(mem, memorySize)
if err != nil {
return 0, err
}
var overflow bool
if gas, overflow = math.SafeAdd(gas, gt.Calls); overflow {
return 0, errGasUintOverflow
}
cg, err := callGas(gt, contract.Gas, gas, stack.Back(0))
if err != nil {
return 0, err
}
// Replace the stack item with the new gas calculation. This means that
// either the original item is left on the stack or the item is replaced by:
// (availableGas - gas) * 63 / 64
// We replace the stack item so that it's available when the opCall instruction is
// called.
stack.data[stack.len()-1] = new(big.Int).SetUint64(cg)
if gas, overflow = math.SafeAdd(gas, cg); overflow {
return 0, errGasUintOverflow
}
return gas, nil
}
func gasPush(gt params.GasTable, evm *EVM, contract *Contract, stack *Stack, mem *Memory, memorySize uint64) (uint64, error) {
return GasFastestStep, nil
}

31
core/vm/instructions.go
View File

@ -17,6 +17,7 @@
package vm
import (
"errors"
"fmt"
"math/big"
@ -29,6 +30,7 @@ import (
var (
bigZero = new(big.Int)
errWriteProtection = errors.New("evm: write protection")
)
func opAdd(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
@ -656,6 +658,35 @@ func opDelegateCall(pc *uint64, evm *EVM, contract *Contract, memory *Memory, st
return ret, nil
}
func opStaticCall(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
// pop gas
gas := stack.pop().Uint64()
// pop address
addr := stack.pop()
// pop input size and offset
inOffset, inSize := stack.pop(), stack.pop()
// pop return size and offset
retOffset, retSize := stack.pop(), stack.pop()
address := common.BigToAddress(addr)
// Get the arguments from the memory
args := memory.Get(inOffset.Int64(), inSize.Int64())
ret, returnGas, err := evm.StaticCall(contract, address, args, gas)
if err != nil {
stack.push(new(big.Int))
} else {
stack.push(big.NewInt(1))
memory.Set(retOffset.Uint64(), retSize.Uint64(), ret)
}
contract.Gas += returnGas
evm.interpreter.intPool.put(addr, inOffset, inSize, retOffset, retSize)
return ret, nil
}
func opReturn(pc *uint64, evm *EVM, contract *Contract, memory *Memory, stack *Stack) ([]byte, error) {
offset, size := stack.pop(), stack.pop()
ret := memory.GetPtr(offset.Int64(), size.Int64())

15
core/vm/interpreter.go
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@ -69,6 +69,8 @@ func NewInterpreter(evm *EVM, cfg Config) *Interpreter {
// we'll set the default jump table.
if !cfg.JumpTable[STOP].valid {
switch {
case evm.ChainConfig().IsMetropolis(evm.BlockNumber):
cfg.JumpTable = metropolisInstructionSet
case evm.ChainConfig().IsHomestead(evm.BlockNumber):
cfg.JumpTable = homesteadInstructionSet
default:
@ -85,6 +87,18 @@ func NewInterpreter(evm *EVM, cfg Config) *Interpreter {
}
func (in *Interpreter) enforceRestrictions(op OpCode, operation operation, stack *Stack) error {
if in.evm.chainRules.IsMetropolis {
if in.readonly {
// If the interpreter is operating in readonly mode, make sure no
// state-modifying operation is performed. The 3rd stack item
// for a call operation is the value. Transfering value from one
// account to the others means the state is modified and should also
// return with an error.
if operation.writes || (op == CALL && stack.Back(2).BitLen() > 0) {
return errWriteProtection
}
}
}
return nil
}
@ -95,6 +109,7 @@ func (in *Interpreter) enforceRestrictions(op OpCode, operation operation, stack
// considered a revert-and-consume-all-gas operation. No error specific checks
// should be handled to reduce complexity and errors further down the in.
func (in *Interpreter) Run(snapshot int, contract *Contract, input []byte) (ret []byte, err error) {
// Increment the call depth which is restricted to 1024
in.evm.depth++
defer func() { in.evm.depth-- }()

21
core/vm/jump_table.go
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@ -58,8 +58,24 @@ type operation struct {
var (
frontierInstructionSet = NewFrontierInstructionSet()
homesteadInstructionSet = NewHomesteadInstructionSet()
metropolisInstructionSet = NewMetropolisInstructionSet()
)
// NewMetropolisInstructionSet returns the frontier, homestead and
// metropolis instructions.
func NewMetropolisInstructionSet() [256]operation {
// instructions that can be executed during the homestead phase.
instructionSet := NewHomesteadInstructionSet()
instructionSet[STATICCALL] = operation{
execute: opStaticCall,
gasCost: gasStaticCall,
validateStack: makeStackFunc(6, 1),
memorySize: memoryStaticCall,
valid: true,
}
return instructionSet
}
// NewHomesteadInstructionSet returns the frontier and homestead
// instructions that can be executed during the homestead phase.
func NewHomesteadInstructionSet() [256]operation {
@ -810,6 +826,7 @@ func NewFrontierInstructionSet() [256]operation {
validateStack: makeStackFunc(2, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
LOG1: {
execute: makeLog(1),
@ -817,6 +834,7 @@ func NewFrontierInstructionSet() [256]operation {
validateStack: makeStackFunc(3, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
LOG2: {
execute: makeLog(2),
@ -824,6 +842,7 @@ func NewFrontierInstructionSet() [256]operation {
validateStack: makeStackFunc(4, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
LOG3: {
execute: makeLog(3),
@ -831,6 +850,7 @@ func NewFrontierInstructionSet() [256]operation {
validateStack: makeStackFunc(5, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
LOG4: {
execute: makeLog(4),
@ -838,6 +858,7 @@ func NewFrontierInstructionSet() [256]operation {
validateStack: makeStackFunc(6, 0),
memorySize: memoryLog,
valid: true,
writes: true,
},
CREATE: {
execute: opCreate,

7
core/vm/memory_table.go
View File

@ -74,6 +74,13 @@ func memoryDelegateCall(stack *Stack) *big.Int {
return math.BigMax(x, y)
}
func memoryStaticCall(stack *Stack) *big.Int {
x := calcMemSize(stack.Back(4), stack.Back(5))
y := calcMemSize(stack.Back(2), stack.Back(3))
return math.BigMax(x, y)
}
func memoryReturn(stack *Stack) *big.Int {
return calcMemSize(stack.Back(0), stack.Back(1))
}

3
core/vm/opcodes.go
View File

@ -201,6 +201,7 @@ const (
CALLCODE
RETURN
DELEGATECALL
STATICCALL = 0xfa
SELFDESTRUCT = 0xff
)
@ -355,6 +356,7 @@ var opCodeToString = map[OpCode]string{
RETURN: "RETURN",
CALLCODE: "CALLCODE",
DELEGATECALL: "DELEGATECALL",
STATICCALL: "STATICCALL",
SELFDESTRUCT: "SELFDESTRUCT",
PUSH: "PUSH",
@ -405,6 +407,7 @@ var stringToOp = map[string]OpCode{
"CALLDATASIZE": CALLDATASIZE,
"CALLDATACOPY": CALLDATACOPY,
"DELEGATECALL": DELEGATECALL,
"STATICCALL": STATICCALL,
"CODESIZE": CODESIZE,
"CODECOPY": CODECOPY,
"GASPRICE": GASPRICE,