From 223110a5589b325d66bf5f19e08f508f5355f905 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Valentin=20W=C3=BCstholz?= Date: Sun, 8 Jan 2017 10:35:51 +0100 Subject: [PATCH] core, core/vm, cmd/disasm: unify procedures for disassembling evm code. --- cmd/disasm/main.go | 28 +++------------- core/asm.go | 64 ------------------------------------ core/asm/asm.go | 78 ++++++++++++++++++++++++++++++++++++++++++++ core/asm/asm_test.go | 51 +++++++++++++++++++++++++++++ core/vm/asm.go | 61 ---------------------------------- core/vm/disasm.go | 37 --------------------- 6 files changed, 134 insertions(+), 185 deletions(-) delete mode 100644 core/asm.go create mode 100644 core/asm/asm.go create mode 100644 core/asm/asm_test.go delete mode 100644 core/vm/asm.go delete mode 100644 core/vm/disasm.go diff --git a/cmd/disasm/main.go b/cmd/disasm/main.go index e6a9a66761..d9ae20e86d 100644 --- a/cmd/disasm/main.go +++ b/cmd/disasm/main.go @@ -18,43 +18,25 @@ package main import ( - "encoding/hex" "fmt" "io/ioutil" "os" "strings" - "github.com/ethereum/go-ethereum/core/vm" + "github.com/ethereum/go-ethereum/core/asm" ) func main() { - code, err := ioutil.ReadAll(os.Stdin) + in, err := ioutil.ReadAll(os.Stdin) if err != nil { fmt.Println(err) os.Exit(1) } - code, err = hex.DecodeString(strings.TrimSpace(string(code[:]))) + code := strings.TrimSpace(string(in[:])) + fmt.Printf("%v\n", code) + err = asm.PrettyPrintDisassembledInstructions(code) if err != nil { fmt.Printf("Error: %v\n", err) return } - fmt.Printf("%x\n", code) - - for pc := uint64(0); pc < uint64(len(code)); pc++ { - op := vm.OpCode(code[pc]) - - switch op { - case vm.PUSH1, vm.PUSH2, vm.PUSH3, vm.PUSH4, vm.PUSH5, vm.PUSH6, vm.PUSH7, vm.PUSH8, vm.PUSH9, vm.PUSH10, vm.PUSH11, vm.PUSH12, vm.PUSH13, vm.PUSH14, vm.PUSH15, vm.PUSH16, vm.PUSH17, vm.PUSH18, vm.PUSH19, vm.PUSH20, vm.PUSH21, vm.PUSH22, vm.PUSH23, vm.PUSH24, vm.PUSH25, vm.PUSH26, vm.PUSH27, vm.PUSH28, vm.PUSH29, vm.PUSH30, vm.PUSH31, vm.PUSH32: - a := uint64(op) - uint64(vm.PUSH1) + 1 - u := pc + 1 + a - if uint64(len(code)) <= pc || uint64(len(code)) < u { - fmt.Printf("Error: incomplete push instruction at %v\n", pc) - return - } - fmt.Printf("%-5d %v => %x\n", pc, op, code[pc+1:u]) - pc += a - default: - fmt.Printf("%-5d %v\n", pc, op) - } - } } diff --git a/core/asm.go b/core/asm.go deleted file mode 100644 index b2e47b5e91..0000000000 --- a/core/asm.go +++ /dev/null @@ -1,64 +0,0 @@ -// Copyright 2014 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 . - -package core - -import ( - "fmt" - "math/big" - - "github.com/ethereum/go-ethereum/common" - "github.com/ethereum/go-ethereum/core/vm" -) - -func Disassemble(script []byte) (asm []string) { - pc := new(big.Int) - for { - if pc.Cmp(big.NewInt(int64(len(script)))) >= 0 { - return - } - - // Get the memory location of pc - val := script[pc.Int64()] - // Get the opcode (it must be an opcode!) - op := vm.OpCode(val) - - asm = append(asm, fmt.Sprintf("%04v: %v", pc, op)) - - switch op { - case vm.PUSH1, vm.PUSH2, vm.PUSH3, vm.PUSH4, vm.PUSH5, vm.PUSH6, vm.PUSH7, vm.PUSH8, - vm.PUSH9, vm.PUSH10, vm.PUSH11, vm.PUSH12, vm.PUSH13, vm.PUSH14, vm.PUSH15, - vm.PUSH16, vm.PUSH17, vm.PUSH18, vm.PUSH19, vm.PUSH20, vm.PUSH21, vm.PUSH22, - vm.PUSH23, vm.PUSH24, vm.PUSH25, vm.PUSH26, vm.PUSH27, vm.PUSH28, vm.PUSH29, - vm.PUSH30, vm.PUSH31, vm.PUSH32: - pc.Add(pc, common.Big1) - a := int64(op) - int64(vm.PUSH1) + 1 - if int(pc.Int64()+a) > len(script) { - return - } - - data := script[pc.Int64() : pc.Int64()+a] - if len(data) == 0 { - data = []byte{0} - } - asm = append(asm, fmt.Sprintf("%04v: 0x%x", pc, data)) - - pc.Add(pc, big.NewInt(a-1)) - } - - pc.Add(pc, common.Big1) - } -} diff --git a/core/asm/asm.go b/core/asm/asm.go new file mode 100644 index 0000000000..9250a5fab7 --- /dev/null +++ b/core/asm/asm.go @@ -0,0 +1,78 @@ +// Copyright 2014, 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 . + +// Provides support for dealing with EVM assembly instructions (e.g., disassembling them). +package asm + +import ( + "encoding/hex" + "fmt" + + "github.com/ethereum/go-ethereum/core/vm" +) + +// Apply function to each disassembled EVM instruction. +func ForEachDisassembledInstruction(script []byte, fun func(uint64, vm.OpCode, []byte)) error { + for pc := uint64(0); pc < uint64(len(script)); pc++ { + op := vm.OpCode(script[pc]) + switch op { + case vm.PUSH1, vm.PUSH2, vm.PUSH3, vm.PUSH4, vm.PUSH5, vm.PUSH6, vm.PUSH7, vm.PUSH8, vm.PUSH9, vm.PUSH10, vm.PUSH11, vm.PUSH12, vm.PUSH13, vm.PUSH14, vm.PUSH15, vm.PUSH16, vm.PUSH17, vm.PUSH18, vm.PUSH19, vm.PUSH20, vm.PUSH21, vm.PUSH22, vm.PUSH23, vm.PUSH24, vm.PUSH25, vm.PUSH26, vm.PUSH27, vm.PUSH28, vm.PUSH29, vm.PUSH30, vm.PUSH31, vm.PUSH32: + a := uint64(op) - uint64(vm.PUSH1) + 1 + u := pc + 1 + a + if uint64(len(script)) <= pc || uint64(len(script)) < u { + return fmt.Errorf("incomplete push instruction at %v", pc) + } + fun(pc, op, script[pc+1:u]) + pc += a + default: + fun(pc, op, make([]byte, 0)) + } + } + return nil +} + +// Pretty-print all disassembled EVM instructions to stdout. +func PrettyPrintDisassembledInstructions(code string) error { + script, err := hex.DecodeString(code) + if err != nil { + return err + } + + return ForEachDisassembledInstruction(script, func(pc uint64, op vm.OpCode, args []byte) { + if args != nil && 0 < len(args) { + fmt.Printf("%06v: %v 0x%x\n", pc, op, args) + } else { + fmt.Printf("%06v: %v\n", pc, op) + } + }) +} + +// Return all disassembled EVM instructions in human-readable format. +func PrettyPrintedDisassembledInstructions(script []byte) ([]string, error) { + instrs := make([]string, 0) + err := ForEachDisassembledInstruction(script, func(pc uint64, op vm.OpCode, args []byte) { + if args != nil && 0 < len(args) { + instrs = append(instrs, fmt.Sprintf("%06v: %v 0x%x\n", pc, op, args)) + } else { + instrs = append(instrs, fmt.Sprintf("%06v: %v\n", pc, op)) + } + }) + + if err != nil { + return nil, err + } + return instrs, nil +} diff --git a/core/asm/asm_test.go b/core/asm/asm_test.go new file mode 100644 index 0000000000..fc0cd1b25b --- /dev/null +++ b/core/asm/asm_test.go @@ -0,0 +1,51 @@ +// Copyright 2016 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 . + +package asm + +import ( + "testing" + + "encoding/hex" + "github.com/ethereum/go-ethereum/core/vm" +) + +// Tests disassembling the instructions for valid evm code +func TestForEachDisassembledInstructionValid(t *testing.T) { + cnt := 0 + script, _ := hex.DecodeString("61000000") + err := ForEachDisassembledInstruction(script, func(pc uint64, op vm.OpCode, args []byte) { + cnt++ + }) + if err != nil { + t.Errorf("Expected 2, but encountered error %v instead.", err) + } + if cnt != 2 { + t.Errorf("Expected 2, but got %v instead.", cnt) + } +} + +// Tests disassembling the instructions for invalid evm code +func TestForEachDisassembledInstructionInvalid(t *testing.T) { + cnt := 0 + script, _ := hex.DecodeString("6100") + err := ForEachDisassembledInstruction(script, func(pc uint64, op vm.OpCode, args []byte) { + cnt++ + }) + if err == nil { + t.Errorf("Expected an error, but got %v instead.", cnt) + } +} diff --git a/core/vm/asm.go b/core/vm/asm.go deleted file mode 100644 index d7dbde5e82..0000000000 --- a/core/vm/asm.go +++ /dev/null @@ -1,61 +0,0 @@ -// Copyright 2014 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 . - -package vm - -import ( - "fmt" - "math/big" - - "github.com/ethereum/go-ethereum/common" -) - -// Disassemble disassembles the byte code and returns the string -// representation (human readable opcodes). -func Disassemble(script []byte) (asm []string) { - pc := new(big.Int) - for { - if pc.Cmp(big.NewInt(int64(len(script)))) >= 0 { - return - } - - // Get the memory location of pc - val := script[pc.Int64()] - // Get the opcode (it must be an opcode!) - op := OpCode(val) - - asm = append(asm, fmt.Sprintf("%v", op)) - - switch op { - case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32: - pc.Add(pc, common.Big1) - a := int64(op) - int64(PUSH1) + 1 - if int(pc.Int64()+a) > len(script) { - return nil - } - - data := script[pc.Int64() : pc.Int64()+a] - if len(data) == 0 { - data = []byte{0} - } - asm = append(asm, fmt.Sprintf("0x%x", data)) - - pc.Add(pc, big.NewInt(a-1)) - } - - pc.Add(pc, common.Big1) - } -} diff --git a/core/vm/disasm.go b/core/vm/disasm.go deleted file mode 100644 index 2bfea5cbda..0000000000 --- a/core/vm/disasm.go +++ /dev/null @@ -1,37 +0,0 @@ -// Copyright 2015 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 . - -package vm - -import "fmt" - -func Disasm(code []byte) []string { - var out []string - for pc := uint64(0); pc < uint64(len(code)); pc++ { - op := OpCode(code[pc]) - out = append(out, op.String()) - - switch op { - case PUSH1, PUSH2, PUSH3, PUSH4, PUSH5, PUSH6, PUSH7, PUSH8, PUSH9, PUSH10, PUSH11, PUSH12, PUSH13, PUSH14, PUSH15, PUSH16, PUSH17, PUSH18, PUSH19, PUSH20, PUSH21, PUSH22, PUSH23, PUSH24, PUSH25, PUSH26, PUSH27, PUSH28, PUSH29, PUSH30, PUSH31, PUSH32: - a := uint64(op) - uint64(PUSH1) + 1 - out = append(out, fmt.Sprintf("0x%x", code[pc+1:pc+1+a])) - - pc += a - } - } - - return out -}