params: core, core/vm, miner: 64bit gas instructions (#3514)

Reworked the EVM gas instructions to use 64bit integers rather than
arbitrary size big ints. All gas operations, be it additions,
multiplications or divisions, are checked and guarded against 64 bit
integer overflows.

In additon, most of the protocol paramaters in the params package have
been converted to uint64 and are now constants rather than variables.

* common/math: added overflow check ops
* core: vmenv, env renamed to evm
* eth, internal/ethapi, les: unmetered eth_call and cancel methods
* core/vm: implemented big.Int pool for evm instructions
* core/vm: unexported intPool methods & verification methods
* core/vm: added memoryGasCost overflow check and test

6 files changed, 20 insertions, 18 deletions

diff --git a/eth/api_backend.go b/eth/api_backend.go
index 1174588ea..72ed76cc4 100644
--- a/eth/api_backend.go
+++ b/eth/api_backend.go
@@ -106,14 +106,14 @@ func (b *EthApiBackend) GetTd(blockHash common.Hash) *big.Int {
 	return b.eth.blockchain.GetTdByHash(blockHash)
 }
 
-func (b *EthApiBackend) GetVMEnv(ctx context.Context, msg core.Message, state ethapi.State, header *types.Header) (*vm.EVM, func() error, error) {
+func (b *EthApiBackend) GetEVM(ctx context.Context, msg core.Message, state ethapi.State, header *types.Header, vmCfg vm.Config) (*vm.EVM, func() error, error) {
 	statedb := state.(EthApiState).state
 	from := statedb.GetOrNewStateObject(msg.From())
 	from.SetBalance(common.MaxBig)
 	vmError := func() error { return nil }
 
 	context := core.NewEVMContext(msg, header, b.eth.BlockChain())
-	return vm.NewEVM(context, statedb, b.eth.chainConfig, vm.Config{}), vmError, nil
+	return vm.NewEVM(context, statedb, b.eth.chainConfig, vmCfg), vmError, nil
 }
 
 func (b *EthApiBackend) SendTx(ctx context.Context, signedTx *types.Transaction) error {
diff --git a/eth/bind.go b/eth/bind.go
index a9864b367..2ee9f2bf7 100644
--- a/eth/bind.go
+++ b/eth/bind.go
@@ -69,7 +69,7 @@ func (b *ContractBackend) PendingCodeAt(ctx context.Context, contract common.Add
 // against the pending block, not the stable head of the chain.
 func (b *ContractBackend) CallContract(ctx context.Context, msg ethereum.CallMsg, blockNum *big.Int) ([]byte, error) {
 	out, err := b.bcapi.Call(ctx, toCallArgs(msg), toBlockNumber(blockNum))
-	return common.FromHex(out), err
+	return out, err
 }
 
 // ContractCall implements bind.ContractCaller executing an Ethereum contract
@@ -77,7 +77,7 @@ func (b *ContractBackend) CallContract(ctx context.Context, msg ethereum.CallMsg
 // against the pending block, not the stable head of the chain.
 func (b *ContractBackend) PendingCallContract(ctx context.Context, msg ethereum.CallMsg) ([]byte, error) {
 	out, err := b.bcapi.Call(ctx, toCallArgs(msg), rpc.PendingBlockNumber)
-	return common.FromHex(out), err
+	return out, err
 }
 
 func toCallArgs(msg ethereum.CallMsg) ethapi.CallArgs {
diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index 9be4bd87d..7e2952439 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -49,12 +49,12 @@ var (
 	MaxReceiptFetch = 256 // Amount of transaction receipts to allow fetching per request
 	MaxStateFetch   = 384 // Amount of node state values to allow fetching per request
 
-	MaxForkAncestry  = 3 * params.EpochDuration.Uint64() // Maximum chain reorganisation
-	rttMinEstimate   = 2 * time.Second                   // Minimum round-trip time to target for download requests
-	rttMaxEstimate   = 20 * time.Second                  // Maximum rount-trip time to target for download requests
-	rttMinConfidence = 0.1                               // Worse confidence factor in our estimated RTT value
-	ttlScaling       = 3                                 // Constant scaling factor for RTT -> TTL conversion
-	ttlLimit         = time.Minute                       // Maximum TTL allowance to prevent reaching crazy timeouts
+	MaxForkAncestry  = 3 * params.EpochDuration // Maximum chain reorganisation
+	rttMinEstimate   = 2 * time.Second          // Minimum round-trip time to target for download requests
+	rttMaxEstimate   = 20 * time.Second         // Maximum rount-trip time to target for download requests
+	rttMinConfidence = 0.1                      // Worse confidence factor in our estimated RTT value
+	ttlScaling       = 3                        // Constant scaling factor for RTT -> TTL conversion
+	ttlLimit         = time.Minute              // Maximum TTL allowance to prevent reaching crazy timeouts
 
 	qosTuningPeers   = 5    // Number of peers to tune based on (best peers)
 	qosConfidenceCap = 10   // Number of peers above which not to modify RTT confidence
diff --git a/eth/downloader/downloader_test.go b/eth/downloader/downloader_test.go
index b156c471d..a9ea797ea 100644
--- a/eth/downloader/downloader_test.go
+++ b/eth/downloader/downloader_test.go
@@ -119,7 +119,7 @@ func (dl *downloadTester) makeChain(n int, seed byte, parent *types.Block, paren
 		// If the block number is multiple of 3, send a bonus transaction to the miner
 		if parent == dl.genesis && i%3 == 0 {
 			signer := types.MakeSigner(params.TestChainConfig, block.Number())
-			tx, err := types.SignTx(types.NewTransaction(block.TxNonce(testAddress), common.Address{seed}, big.NewInt(1000), params.TxGas, nil, nil), signer, testKey)
+			tx, err := types.SignTx(types.NewTransaction(block.TxNonce(testAddress), common.Address{seed}, big.NewInt(1000), new(big.Int).SetUint64(params.TxGas), nil, nil), signer, testKey)
 			if err != nil {
 				panic(err)
 			}
diff --git a/eth/fetcher/fetcher_test.go b/eth/fetcher/fetcher_test.go
index 2e28541ab..7a94241c6 100644
--- a/eth/fetcher/fetcher_test.go
+++ b/eth/fetcher/fetcher_test.go
@@ -51,7 +51,7 @@ func makeChain(n int, seed byte, parent *types.Block) ([]common.Hash, map[common
 		// If the block number is multiple of 3, send a bonus transaction to the miner
 		if parent == genesis && i%3 == 0 {
 			signer := types.MakeSigner(params.TestChainConfig, block.Number())
-			tx, err := types.SignTx(types.NewTransaction(block.TxNonce(testAddress), common.Address{seed}, big.NewInt(1000), params.TxGas, nil, nil), signer, testKey)
+			tx, err := types.SignTx(types.NewTransaction(block.TxNonce(testAddress), common.Address{seed}, big.NewInt(1000), new(big.Int).SetUint64(params.TxGas), nil, nil), signer, testKey)
 			if err != nil {
 				panic(err)
 			}
diff --git a/eth/handler_test.go b/eth/handler_test.go
index 8a5d7173b..03d5404a4 100644
--- a/eth/handler_test.go
+++ b/eth/handler_test.go
@@ -36,6 +36,8 @@ import (
 	"github.com/ethereum/go-ethereum/params"
 )
 
+var bigTxGas = new(big.Int).SetUint64(params.TxGas)
+
 // Tests that protocol versions and modes of operations are matched up properly.
 func TestProtocolCompatibility(t *testing.T) {
 	// Define the compatibility chart
@@ -312,13 +314,13 @@ func testGetNodeData(t *testing.T, protocol int) {
 		switch i {
 		case 0:
 			// In block 1, the test bank sends account #1 some ether.
-			tx, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(10000), params.TxGas, nil, nil), signer, testBankKey)
+			tx, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(10000), bigTxGas, nil, nil), signer, testBankKey)
 			block.AddTx(tx)
 		case 1:
 			// In block 2, the test bank sends some more ether to account #1.
 			// acc1Addr passes it on to account #2.
-			tx1, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil), signer, testBankKey)
-			tx2, _ := types.SignTx(types.NewTransaction(block.TxNonce(acc1Addr), acc2Addr, big.NewInt(1000), params.TxGas, nil, nil), signer, acc1Key)
+			tx1, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(1000), bigTxGas, nil, nil), signer, testBankKey)
+			tx2, _ := types.SignTx(types.NewTransaction(block.TxNonce(acc1Addr), acc2Addr, big.NewInt(1000), bigTxGas, nil, nil), signer, acc1Key)
 			block.AddTx(tx1)
 			block.AddTx(tx2)
 		case 2:
@@ -404,13 +406,13 @@ func testGetReceipt(t *testing.T, protocol int) {
 		switch i {
 		case 0:
 			// In block 1, the test bank sends account #1 some ether.
-			tx, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(10000), params.TxGas, nil, nil), signer, testBankKey)
+			tx, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(10000), bigTxGas, nil, nil), signer, testBankKey)
 			block.AddTx(tx)
 		case 1:
 			// In block 2, the test bank sends some more ether to account #1.
 			// acc1Addr passes it on to account #2.
-			tx1, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil), signer, testBankKey)
-			tx2, _ := types.SignTx(types.NewTransaction(block.TxNonce(acc1Addr), acc2Addr, big.NewInt(1000), params.TxGas, nil, nil), signer, acc1Key)
+			tx1, _ := types.SignTx(types.NewTransaction(block.TxNonce(testBank.Address), acc1Addr, big.NewInt(1000), bigTxGas, nil, nil), signer, testBankKey)
+			tx2, _ := types.SignTx(types.NewTransaction(block.TxNonce(acc1Addr), acc2Addr, big.NewInt(1000), bigTxGas, nil, nil), signer, acc1Key)
 			block.AddTx(tx1)
 			block.AddTx(tx2)
 		case 2: