Created
August 29, 2020 14:27
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Quick&dirty verbose LuaJIT's bytecode version 1 disassembler
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| #!/usr/bin/env python3 | |
| import sys | |
| import struct | |
| import math | |
| # Constants | |
| # Internal (LEB128 buffer) | |
| MAX_ULEB_SIZE = 256 # Maximum proto size here is 2^7^256 | |
| # Reference: https://github.com/LuaJit/LuaJIT/bloc/master/src/lj_bc.h | |
| class ByteCode: | |
| OP_VAR = 1 | |
| OP_STR = 2 | |
| OP_NUM = 3 | |
| OP_PRI = 4 | |
| OP_DST = 5 | |
| OP_RBASE = 6 | |
| OP_BASE = 7 | |
| OP_CDATA = 8 | |
| OP_LIT = 9 # Literal | |
| OP_LITS = 10 # Signed literal | |
| OP_FUNC = 11 | |
| OP_UV = 12 | |
| OP_JUMP = 13 | |
| OP_TAB = 14 | |
| OP_MNUM = 15 # Multiple nums | |
| OP_NIL = 16 # Always nil | |
| BC_MODE = 0 | |
| AD_MODE = 1 | |
| OPCODE_TABLE = { | |
| 0x00: {"op": "ISLT", "A": OP_VAR, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "JMP if {A}<{D}"}, | |
| 0x01: {"op": "ISGE", "A": OP_VAR, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "JMP if {A}>={D}"}, | |
| 0x02: {"op": "ISLE", "A": OP_VAR, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "JMP if {A}<={D}"}, | |
| 0x03: {"op": "ISGT", "A": OP_VAR, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "JMP if {A}>{D}"}, | |
| 0x04: {"op": "ISEQV", "A": OP_VAR, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "JMP if {A}={D}"}, | |
| 0x05: {"op": "ISNEV", "A": OP_VAR, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "JMP if {A}!={D}"}, | |
| 0x06: {"op": "ISEQS", "A": OP_VAR, "B": None, "CD": OP_STR, "mode": AD_MODE, "desc": "JMP if {A}=(STR)D"}, # For STR constants? | |
| 0x07: {"op": "ISNES", "A": OP_VAR, "B": None, "CD": OP_STR, "mode": AD_MODE, "desc": "JMP if {A}!=(STR)D"}, | |
| 0x08: {"op": "ISEQN", "A": OP_VAR, "B": None, "CD": OP_NUM, "mode": AD_MODE, "desc": "JMP if {A}=(NUM)D"}, # For NUM constants? | |
| 0x09: {"op": "ISNEN", "A": OP_VAR, "B": None, "CD": OP_NUM, "mode": AD_MODE, "desc": "JMP if {A}!=(NUM)D"}, | |
| 0x0A: {"op": "ISEQP", "A": OP_VAR, "B": None, "CD": OP_PRI, "mode": AD_MODE, "desc": "JMP if {A}=D (primitive 0=nil,1=false,2=true)"}, | |
| 0x0B: {"op": "ISNEP", "A": OP_VAR, "B": None, "CD": OP_PRI, "mode": AD_MODE, "desc": "JMP if {A}!=D (primitive 0=nil,1=false,2=true)"}, | |
| 0x0C: {"op": "ISTC", "A": OP_DST, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "{A}<=copy={D} then JMP if {D}=true"}, | |
| 0x0D: {"op": "ISFC", "A": OP_DST, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "{A}<=copy={D} then JMP if {D}=false"}, | |
| 0x0E: {"op": "IST", "A": None, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "JMP if {D}=true"}, | |
| 0x0F: {"op": "ISF", "A": None, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "JMP if {D}=false"}, | |
| 0x10: {"op": "MOV", "A": OP_DST, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "{A}<=copy={D}"}, | |
| 0x11: {"op": "NOT", "A": OP_DST, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "{A} <= NOT {D}"}, | |
| 0x12: {"op": "UNM", "A": OP_DST, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "{A} <= -{D} (unary minus)"}, | |
| 0x13: {"op": "LEN", "A": OP_DST, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "{A} <= len({D})"}, | |
| 0x14: {"op": "ADDVN", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= {B} + (NUM)C"}, | |
| 0x15: {"op": "SUBVN", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= {B} - (NUM)C"}, | |
| 0x16: {"op": "MULVN", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= {B} * (NUM)C"}, | |
| 0x17: {"op": "DIVVN", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= {B} / (NUM)C"}, | |
| 0x18: {"op": "MODVN", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= {B} % (NUM)C"}, | |
| 0x19: {"op": "ADDNV", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= (NUM)C + {B}"}, | |
| 0x1A: {"op": "SUBNV", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= (NUM)C - {B}"}, | |
| 0x1B: {"op": "MULNV", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= (NUM)C * {B}"}, | |
| 0x1C: {"op": "DIVNV", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= (NUM)C / {B}"}, | |
| 0x1D: {"op": "MODNV", "A": OP_DST, "B": OP_VAR, "CD": OP_NUM, "mode": BC_MODE, "desc": "{A} <= (NUM)C % {B}"}, | |
| 0x1E: {"op": "ADDVV", "A": OP_DST, "B": OP_VAR, "CD": OP_VAR, "mode": BC_MODE, "desc": "{A} <= {B} + {C}"}, | |
| 0x1F: {"op": "SUBVV", "A": OP_DST, "B": OP_VAR, "CD": OP_VAR, "mode": BC_MODE, "desc": "{A} <= {B} - {C}"}, | |
| 0x20: {"op": "MULVV", "A": OP_DST, "B": OP_VAR, "CD": OP_VAR, "mode": BC_MODE, "desc": "{A} <= {B} * {C}"}, | |
| 0x21: {"op": "DIVVV", "A": OP_DST, "B": OP_VAR, "CD": OP_VAR, "mode": BC_MODE, "desc": "{A} <= {B} / {C}"}, | |
| 0x22: {"op": "MODVV", "A": OP_DST, "B": OP_VAR, "CD": OP_VAR, "mode": BC_MODE, "desc": "{A} <= {B} % {C}"}, | |
| 0x23: {"op": "POW", "A": OP_DST, "B": OP_VAR, "CD": OP_VAR, "mode": BC_MODE, "desc": "{A} <= {B} ^ {C}"}, | |
| 0x24: {"op": "CAT", "A": OP_DST, "B": OP_RBASE, "CD": OP_RBASE, "mode": BC_MODE, "desc": "{A} <= {B} ~ {B+1} ~ ... ~ {C}"}, | |
| 0x25: {"op": "KSTR", "A": OP_DST, "B": None, "CD": OP_STR, "mode": AD_MODE, "desc": "{A} <= (STR)D"}, | |
| 0x26: {"op": "KCDATA", "A": OP_DST, "B": None, "CD": OP_CDATA, "mode": AD_MODE, "desc": "{A} <= (CDATA)D"}, | |
| 0x27: {"op": "KSHORT", "A": OP_DST, "B": None, "CD": OP_LITS, "mode": AD_MODE, "desc": "{A} <= D (16-bit signed int)"}, | |
| 0x28: {"op": "KNUM", "A": OP_DST, "B": None, "CD": OP_NUM, "mode": AD_MODE, "desc": "{A} <= (NUM)D"}, | |
| 0x29: {"op": "KPRI", "A": OP_DST, "B": None, "CD": OP_PRI, "mode": AD_MODE, "desc": "{A} <= D (primitive 0=nil,1=false,2=true)"}, | |
| 0x2A: {"op": "KNIL", "A": OP_BASE, "B": None, "CD": OP_BASE, "mode": AD_MODE, "desc": "{A} <= nil, {A+1} <= nil, ..., {D} <= nil"}, | |
| 0x2B: {"op": "UGET", "A": OP_DST, "B": None, "CD": OP_UV, "mode": AD_MODE, "desc": "{A} <= uv(D)"}, | |
| 0x2C: {"op": "USETV", "A": OP_UV, "B": None, "CD": OP_VAR, "mode": AD_MODE, "desc": "uv(A) <= {D}"}, | |
| 0x2D: {"op": "USETS", "A": OP_UV, "B": None, "CD": OP_STR, "mode": AD_MODE, "desc": "uv(A) <= (STR)D"}, | |
| 0x2E: {"op": "USETN", "A": OP_UV, "B": None, "CD": OP_NUM, "mode": AD_MODE, "desc": "uv(A) <= (NUM)D"}, | |
| 0x2F: {"op": "USETP", "A": OP_UV, "B": None, "CD": OP_PRI, "mode": AD_MODE, "desc": "uv(A) <= D (primitive 0=nil,1=false,2=true)"}, | |
| 0x30: {"op": "UCLO", "A": OP_RBASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Closes uv for slots >= A and JMP => D"}, | |
| 0x31: {"op": "FNEW", "A": OP_DST, "B": None, "CD": OP_FUNC, "mode": AD_MODE, "desc": "{A} <= closure(proto(D))"}, | |
| 0x32: {"op": "TNEW", "A": OP_DST, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "{A}<=[new_tab[D&0x07FF] new_hash[(D&0xF800)>>11]]"}, | |
| 0x33: {"op": "TDUP", "A": OP_DST, "B": None, "CD": OP_TAB, "mode": AD_MODE, "desc": "{A} <= (TAB)D"}, | |
| 0x34: {"op": "GGET", "A": OP_DST, "B": None, "CD": OP_STR, "mode": AD_MODE, "desc": "{A} <= _G[(STR)D] (see getfenv(1))"}, | |
| 0x35: {"op": "GSET", "A": OP_VAR, "B": None, "CD": OP_STR, "mode": AD_MODE, "desc": "_G[(STR)D] <= {A} (see getfenv(1))"}, | |
| 0x36: {"op": "TGETV", "A": OP_DST, "B": OP_VAR, "CD": OP_VAR, "mode": BC_MODE, "desc": "{A} <= {B}[{C}]"}, | |
| 0x37: {"op": "TGETS", "A": OP_DST, "B": OP_VAR, "CD": OP_STR, "mode": BC_MODE, "desc": "{A} <= {B}[(STR)C]"}, | |
| 0x38: {"op": "TGETB", "A": OP_DST, "B": OP_VAR, "CD": OP_LIT, "mode": BC_MODE, "desc": "{A} <= {B}[C]"}, | |
| 0x39: {"op": "TSETV", "A": OP_VAR, "B": OP_VAR, "CD": OP_VAR, "mode": BC_MODE, "desc": "{B}[{C}] <= {A}"}, | |
| 0x3A: {"op": "TSETS", "A": OP_VAR, "B": OP_VAR, "CD": OP_STR, "mode": BC_MODE, "desc": "{B}[(STR)C] <= {A}"}, | |
| 0x3B: {"op": "TSETB", "A": OP_VAR, "B": OP_VAR, "CD": OP_LIT, "mode": BC_MODE, "desc": "{B}[C] <= {A}"}, | |
| 0x3C: {"op": "TSETM", "A": OP_BASE, "B": None, "CD": OP_MNUM, "mode": AD_MODE, "desc": "{A-1}[(NUM)D],{A-1}[D+1],...<= {A}, {A+1}, ..."}, | |
| 0x3D: {"op": "CALLM", "A": OP_BASE, "B": OP_LIT, "CD": OP_LIT, "mode": BC_MODE, "desc": "{A},...,{A+B-2}<={A}({A+1},...,{A+C+MULTRES})"}, | |
| 0x3E: {"op": "CALL", "A": OP_BASE, "B": OP_LIT, "CD": OP_LIT, "mode": BC_MODE, "desc": "{A},...,{A+B-2} <= {A}({A+1},...,{A+C-1})"}, | |
| 0x3F: {"op": "CALLMT", "A": OP_BASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "Tailcall: {A}({A+1},...,{A+D+MULTRES})"}, | |
| 0x40: {"op": "CALLT", "A": OP_BASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "Tailcall: {A}({A+1},...,{A+D-1})"}, | |
| 0x41: {"op": "ITERC", "A": OP_BASE, "B": OP_LIT, "CD": OP_LIT, "mode": BC_MODE, "desc": "Iterator: {A},{A+1},{A+2}<={A-3},{A-2},{A-1};{A},...,{A+B-2} <= {A}({A+1},{A+2})"}, | |
| 0x42: {"op": "ITERN", "A": OP_BASE, "B": OP_LIT, "CD": OP_LIT, "mode": BC_MODE, "desc": "Specialized ITERC, if iterator function {A-3} is next()"}, | |
| 0x43: {"op": "VARG", "A": OP_BASE, "B": OP_LIT, "CD": OP_LIT, "mode": BC_MODE, "desc": "Vararg: {A},...{A+B-2} <= ..."}, | |
| 0x44: {"op": "ISNEXT", "A": OP_BASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Verify ITERN specialization and jump"}, | |
| 0x45: {"op": "RETM", "A": OP_BASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "return {A},...,{A+D+MULTRES-1}"}, | |
| 0x46: {"op": "RET", "A": OP_RBASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "return {A},...,{A+D-2}"}, | |
| 0x47: {"op": "RET0", "A": OP_RBASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "return"}, | |
| 0x48: {"op": "RET1", "A": OP_RBASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "return {A}"}, | |
| 0x49: {"op": "FORI", "A": OP_BASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Numeric for loop init"}, | |
| 0x4A: {"op": "JFORI", "A": OP_BASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Numeric for loop init JIT-compiled"}, | |
| 0x4B: {"op": "FORL", "A": OP_BASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Numeric for loop"}, | |
| 0x4C: {"op": "IFORL", "A": OP_BASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Numeric for loop force interpreter"}, | |
| 0x4D: {"op": "JFORL", "A": OP_BASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "Numeric for loop JIT-compiled"}, | |
| 0x4E: {"op": "ITERL", "A": OP_BASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Iterator for loop"}, | |
| 0x4F: {"op": "IITERL", "A": OP_BASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Iterator for loop force interpreter"}, | |
| 0x50: {"op": "JITERL", "A": OP_BASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "Iterator for loop JIT-compiled"}, | |
| 0x51: {"op": "LOOP", "A": OP_RBASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Generic loop"}, | |
| 0x52: {"op": "ILOOP", "A": OP_RBASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Generic loop, force interpreter"}, | |
| 0x53: {"op": "JLOOP", "A": OP_RBASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "Generic loop,JIT-Compiled"}, | |
| 0x54: {"op": "JMP", "A": OP_RBASE, "B": None, "CD": OP_JUMP, "mode": AD_MODE, "desc": "Jump"}, | |
| 0x55: {"op": "FUNCF", "A": OP_RBASE, "B": None, "CD": OP_NIL, "mode": AD_MODE, "desc": "Fixed-arg Lua function"}, | |
| 0x56: {"op": "IFUNCF", "A": OP_RBASE, "B": None, "CD": OP_NIL, "mode": AD_MODE, "desc": "Fixed-arg Lua function, force interpreter"}, | |
| 0x57: {"op": "JFUNCF", "A": OP_RBASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "Fixed-arg Lua function JIT-Compiled"}, | |
| 0x58: {"op": "FUNCV", "A": OP_RBASE, "B": None, "CD": OP_NIL, "mode": AD_MODE, "desc": "Vararg Lua function"}, | |
| 0x59: {"op": "IFUNCV", "A": OP_RBASE, "B": None, "CD": OP_NIL, "mode": AD_MODE, "desc": "Vararg Lua function, force interpreter"}, | |
| 0x5A: {"op": "JFUNCV", "A": OP_RBASE, "B": None, "CD": OP_LIT, "mode": AD_MODE, "desc": "Vararg Lua function, JIT-compiled"}, | |
| 0x5B: {"op": "FUNCC", "A": OP_RBASE, "B": None, "CD": OP_NIL, "mode": AD_MODE, "desc": "Pseudo-header for C functions"}, | |
| 0x5C: {"op": "FUNCCW", "A": OP_RBASE, "B": None, "CD": OP_NIL, "mode": AD_MODE, "desc": "Pseudo-header for wrapped C functions"}, | |
| 0x5D: {"op": "FUNC", "A": OP_RBASE, "B": None, "CD": OP_NIL, "mode": AD_MODE, "desc": "Pseudo-header for fast functions"}, | |
| } | |
| @staticmethod | |
| def listBC(bytecode, kgc=None, knum=None, upvalues=None): | |
| outStr = "N\tOP\tA\tB/D\tC\tComment\n" | |
| i = 1 | |
| for ins in bytecode: | |
| if len(ins) != 4: | |
| # An instruction is always a 32-bit word | |
| continue | |
| # If the OPCODE >= 5D, we have a fast function pseudo-header | |
| op = {"op": "FUNC", "A": ByteCode.OP_RBASE, "B": None, "CD": ByteCode.OP_NIL, "mode": ByteCode.AD_MODE, "desc": "Pseudo-header for fast functions"} | |
| if ins[0] in ByteCode.OPCODE_TABLE.keys(): | |
| op = ByteCode.OPCODE_TABLE[ins[0]] | |
| outStr += "%03d\t%s\t" % (i,op['op']) | |
| outStr += "%d\t" % ins[1] | |
| if op['mode'] == ByteCode.BC_MODE: | |
| outStr += "%d\t%d\t; %s\n" % (ins[3], ins[2], op["desc"]) | |
| else: | |
| outStr += "0x%02x%02x\t\t; %s\n" % (ins[3], ins[2], op['desc']) | |
| # FIXME ugly part | |
| if op["A"] == ByteCode.OP_PRI: | |
| pri = "true" | |
| if ins[1] == 0: | |
| pri = "nil" | |
| elif ins[1] == 1: | |
| pri = "false" | |
| outStr += "\t(PRI)A= %s\n" % pri | |
| if op["B"] == ByteCode.OP_PRI: | |
| pri = "true" | |
| if ins[3] == 0: | |
| pri = "nil" | |
| elif ins[3] == 1: | |
| pri = "false" | |
| outStr += "\t(PRI)B= %s\n" % pri | |
| if op["CD"] == ByteCode.OP_PRI: | |
| j = 2 | |
| pri = "true" | |
| if ins[j] == 0: | |
| pri = "nil" | |
| elif ins[j] == 1: | |
| pri = "false" | |
| outStr += "\t(PRI)C/D= %s\n" % pri | |
| if op["CD"] == ByteCode.OP_JUMP: | |
| outStr += "\tJMP => %d\n" % (i + 1 + struct.unpack("H", bytes([ins[2],ins[3]]))[0] - 0x8000) | |
| if kgc is not None: | |
| # TODO cover other kgc types (tab) | |
| if op["A"] == ByteCode.OP_STR: | |
| outStr += "\t(STR)A= \"%s\"\n" % kgc[ins[1]].getValue() | |
| if op['B'] == ByteCode.OP_STR: | |
| outStr += "\t(STR)B= \"%s\"\n" % kgc[ins[3]].getValue() | |
| if op['CD'] == ByteCode.OP_STR and op["mode"] == ByteCode.BC_MODE: | |
| outStr += "\t(STR)C= \"%s\"\n" % kgc[ins[2]].getValue() | |
| elif op['CD'] == ByteCode.OP_STR: | |
| outStr += "\t(STR)D= \"%s\"\n" % kgc[struct.unpack("<H", ins[2:4])[0]].getValue() | |
| if knum is not None: | |
| if op["A"] == ByteCode.OP_NUM: | |
| if type(knum[ins[1]]) == int: | |
| outStr += "\t(NUM)A= %d\n" % knum[ins[1]] | |
| elif type(knum[ins[1]]) == float: | |
| outStr += "\t(NUM)A= %f\n" % knum[ins[1]] | |
| if op['B'] == ByteCode.OP_NUM: | |
| if type(knum[ins[3]]) == int: | |
| outStr += "\t(NUM)B= %d\n" % knum[ins[3]] | |
| elif type(knum[ins[3]]) == float: | |
| outStr += "\t(NUM)B= %f\n" % knum[ins[3]] | |
| if op['CD'] == ByteCode.OP_NUM and op["mode"] == ByteCode.BC_MODE: | |
| if type(knum[ins[2]]) == int: | |
| outStr += "\t(NUM)C= %d\n" % knum[ins[2]] | |
| elif type(knum[ins[2]]) == float: | |
| outStr += "\t(NUM)C= %f\n" % knum[ins[2]] | |
| elif op['CD'] == ByteCode.OP_NUM: | |
| val = knum[struct.unpack("<H", ins[2:4])[0]] | |
| if type(val) == int: | |
| outStr += "\t(NUM)D= %d\n" % val | |
| elif type(val) == float: | |
| outStr += "\t(NUM)D= %f\n" % val | |
| i += 1 | |
| return outStr | |
| def read_uleb128(buff): | |
| # Adapted from https://github.com/LuaJit/LuaJIT/blob/master/src/ls_bcread. l. 136 | |
| result = buff[0] | |
| i = 1 | |
| if result >= 0x80: | |
| shift = 0 | |
| result &= 0x7F | |
| while True: | |
| shift += 7 | |
| result |= ((buff[i] & 0x7F) << shift) | |
| i += 1 | |
| if buff[i-1] < 0x80: | |
| break | |
| return [result, i] | |
| def read_uleb128_33(buff): | |
| # Adapted from https://github.com/LuaJit/LuaJIT/blob/master/src/lj_bcread.c l. 154 | |
| # FIXME not tested yet | |
| result = buff[0] >> 1 | |
| i = 1 | |
| if result >= 0x40: | |
| shift = -1 | |
| result &= 0x3F | |
| while True: | |
| ch = buff[i] | |
| shift += 7 | |
| result |= (ch & 0x7F) << shift | |
| i += 1 | |
| if buff[i-1] < 0x80: | |
| return [result, i] | |
| return [result, i] | |
| def hexd(string): | |
| """ | |
| Helper function to hexdump bytecode | |
| """ | |
| out_val = '' | |
| for ch in string: | |
| out_val += hex(ch) + " " | |
| return out_val | |
| class Kgc: | |
| """ | |
| Class to contain KGC values (a type and a value) | |
| """ | |
| # From: https://github.com/LuaJit/LuaJIT/blob/master/src/lj_obj.h | |
| # KGC types | |
| KGC_UNKNOWN = -1 | |
| KGC_CHILD = 0 | |
| KGC_TAB = 1 | |
| KGC_I64 = 2 | |
| KGC_U64 = 3 | |
| KGC_COMPLEX = 4 | |
| KGC_STR = 5 | |
| # ktabk types | |
| KTAB_NIL = 0 | |
| KTAB_FALSE = 1 | |
| KTAB_TRUE = 2 | |
| KTAB_INT = 3 | |
| KTAB_NUM = 4 | |
| KTAB_STR = 5 | |
| def __init__(self, type_kgc, value): | |
| self.type_kgc = type_kgc | |
| self.value = value | |
| def getType(self): | |
| return self.type_kgc | |
| @staticmethod | |
| def getKtabTypeAsStr(ktype): | |
| if ktype >= Kgc.KTAB_STR: | |
| return "KTAB_STR" | |
| if ktype == Kgc.KTAB_NIL: | |
| return "KTAB_NIL" | |
| if ktype == Kgc.KTAB_FALSE: | |
| return "KTAB_FALSE" | |
| if ktype == Kgc.KTAB_TRUE: | |
| return "KTAB_TRUE" | |
| if ktype == Kgc.KTAB_NUM: | |
| return "KTAB_NUM" | |
| if ktype == Kgc.KTAB_INT: | |
| return "KTAB_INT" | |
| return "Unknown" | |
| def getValue(self): | |
| return self.value | |
| def toStr(self): | |
| outStr = "Type: " | |
| if self.type_kgc == Kgc.KGC_CHILD: | |
| outStr += "KGC_CHILD\t" | |
| elif self.type_kgc == Kgc.KGC_TAB: | |
| outStr += "KGC_TAB\t" | |
| outStr += "karray length: %d\t khash length: %d\n" % (len(self.value["karray"]), len(self.value["khash"])) | |
| for el in self.value["karray"]: | |
| outStr += "\t\ttype: %s\tvalue: " % Kgc.getKtabTypeAsStr(el["type"]) | |
| if el["value"] is None: | |
| outStr += "None\n" | |
| elif el["value"] is False: | |
| outStr += "false\n" | |
| elif el["type"] == Kgc.KTAB_TRUE: | |
| outStr += "true\n" | |
| elif el["type"] == Kgc.KTAB_NUM: | |
| outStr += "lo: %d, hi: %d" % (el["value"][0],el["value"][1]) | |
| elif el["type"] >= Kgc.KTAB_STR: | |
| outStr += "%s\n" % el["value"].decode('ascii') | |
| elif el["type"] == Kgc.KTAB_INT: | |
| outStr += "%d\n" % el["value"] | |
| else: | |
| outStr += "Should not happen DUH!\n" | |
| # TODO ugly | |
| for el in self.value["khash"]: | |
| outStr += "\t\tkey:" + el["key"].decode('ascii') + "\ttype: %s\tvalue: " % Kgc.getKtabTypeAsStr(el["type"]) | |
| if el["value"] is None: | |
| outStr += "None\n" | |
| elif el["value"] is False: | |
| outStr += "false\n" | |
| elif el["type"] == Kgc.KTAB_TRUE: | |
| outStr += "true\n" | |
| elif el["type"] == Kgc.KTAB_NUM: | |
| outStr += "%f" % el['value'] | |
| elif el["type"] >= Kgc.KTAB_STR: | |
| outStr += "%s\n" % el["value"].decode('ascii') | |
| elif el["type"] == Kgc.KTAB_INT: | |
| outStr += "%d\n" % el["value"] | |
| else: | |
| outStr += "Should not happen DUH!\n" | |
| elif self.type_kgc >= Kgc.KGC_STR: | |
| outStr += "KGC_STR\t" | |
| outStr += self.value.decode('ascii') | |
| else: # TODO add the other types here if relevant | |
| outStr += "%d Not supported yet\n" % self.type_kgc | |
| return outStr | |
| class GCProto: | |
| # From: https://github.com/LuaJit/LuaJIT/blob/master/src/lj_obj.h | |
| # GCProto flags | |
| PROTO_CHILD = 0x01 # Indicates if there are child prototypes | |
| PROTO_VARARG = 0x02 # Vararg function | |
| PROTO_FFI = 0x04 # Uses BC_KCDATA for FFI datatypes | |
| PROTO_NOJIT = 0x08 # JIT disabled for this function | |
| PROTO_ILOOP = 0x10 # Patched bytecode with ILOOP, etc... | |
| def __init__(self, f_strip = True): | |
| self.flags = 0x00 # Proto's flags | |
| self.numparams = 0 # Number of parameters | |
| self.framesize = 0 # Fixed frame size | |
| self.numuv = 0 # Number of upvalues | |
| self.numkgc = 0 # Number of collectable constants | |
| self.numkn = 0 # Number of lua_number constants | |
| self.numbc = 0 # Number of bytecode instructions | |
| self.debuglen = 0 # Length of the debugpart in the header | |
| self.debug_firstline = None # First line of the function definition | |
| self.debug_numline = None # Number of lines for the function definition | |
| self.bcins = [] # Bytecode instructions? | |
| self.uvdata = [] # upvalue list | |
| self.kgc = [] # Split constant array | |
| self.knum = [] # Lua number constants | |
| self.debug = [] # Debug bytes | |
| self.f_strip = f_strip # If the GCDump Strip flag is set (debug) | |
| def parseKtabk(self, buff): | |
| """ | |
| Parses a ktabk entry | |
| """ | |
| tot_bytes_read = 0 | |
| uleb_buff_size = min([len(buff), MAX_ULEB_SIZE]) | |
| ktabktype, bytes_read = read_uleb128(buff[:uleb_buff_size]) | |
| tot_bytes_read += bytes_read | |
| return_value = None | |
| if ktabktype >= Kgc.KTAB_STR: | |
| str_len = ktabktype - Kgc.KTAB_STR | |
| ktabk_string = buff[tot_bytes_read:tot_bytes_read+str_len] | |
| tot_bytes_read += str_len | |
| return_value = ktabk_string | |
| elif ktabktype == Kgc.KTAB_INT: | |
| uleb_buff_size = min([len(buff[tot_bytes_read:]), MAX_ULEB_SIZE]) | |
| return_value, bytes_read = read_uleb128(buff[tot_bytes_read:tot_bytes_read+uleb_buff_size]) | |
| tot_bytes_read += bytes_read | |
| elif ktabktype == Kgc.KTAB_NUM: | |
| uleb_buff_size = min([len(buff[tot_bytes_read:]), MAX_ULEB_SIZE]) | |
| lo, bytes_read = read_uleb128(buff[tot_bytes_read:tot_bytes_read+uleb_buff_size]) | |
| tot_bytes_read += bytes_read | |
| uleb_buff_size = min([len(buff[tot_bytes_read:]), MAX_ULEB_SIZE]) | |
| hi, bytes_read = read_uleb128(buff[tot_bytes_read:tot_bytes_read+uleb_buff_size]) | |
| tot_bytes_read += bytes_read | |
| return_value = [lo, hi] | |
| else: # Boolean or nil | |
| if ktabktype == Kgc.KTAB_TRUE: | |
| return_value = True | |
| elif ktabktype == Kgc.KTAB_FALSE: | |
| return_value = False | |
| else: | |
| return_value = None | |
| return [ktabktype, return_value, tot_bytes_read] | |
| def parseFromBuff(self, buff): | |
| """ | |
| Parses buffer to identify proto header and body | |
| """ | |
| # A proto header has at least 7 bytes, so there is an error if it is less | |
| if len(buff) < 7: | |
| return | |
| # The first header elements are quite simple | |
| self.flags = buff[0] | |
| self.numparams = buff[1] | |
| self.framesize = buff[2] | |
| self.numuv = buff[3] | |
| # LEB128 needs some precautions (in case they are multibyte) | |
| uleb_buff_size = min([len(buff)-4, MAX_ULEB_SIZE]) | |
| self.numkgc, bytes_read = read_uleb128(buff[4:4+uleb_buff_size]) | |
| off = 4 + bytes_read | |
| uleb_buff_size = min([len(buff)-off, MAX_ULEB_SIZE]) | |
| self.numkn, bytes_read = read_uleb128(buff[off:off+uleb_buff_size]) | |
| off += bytes_read | |
| uleb_buff_size = min([len(buff)-off, MAX_ULEB_SIZE]) | |
| self.numbc, bytes_read = read_uleb128(buff[off:off+uleb_buff_size]) | |
| # See https://github.com/LuaJIT/LuaJIT/blob/master/src/lj_bcread.c line 357 | |
| # The following code is about debug bytes retrieval | |
| # I don't interpret them at the moment, this is just to let the pointer increment and skip this part is it exists | |
| if not self.f_strip: | |
| off += bytes_read | |
| uleb_buff_size = min([len(buff)-off, MAX_ULEB_SIZE]) | |
| self.debuglen, bytes_read = read_uleb128(buff[off:uleb_buff_size]) | |
| if self.debuglen > 0: | |
| off += bytes_read | |
| uleb_buff_size = min([len(buff)-off,MAX_ULEB_SIZE]) | |
| self.debug_firstline, bytes_read = read_uleb128(buff[off:uleb_buff_size]) | |
| off += bytes_read | |
| uleb_buff_size = min([len(buff)-off, MAX_ULEB_SIZE]) | |
| self.debug_numline, bytes_read = read_uleb128(buff[off:uleb_buff_size]) | |
| # This is the end of the header | |
| # The first thing after is the bytecode listing | |
| # Each instruction has a size of a 32-bit word | |
| # We don't disassemble the bytecode yet, maybe a bit later | |
| off += bytes_read | |
| base = off | |
| while off < base + self.numbc * 4: | |
| self.bcins.append(buff[off:off+4]) | |
| off += 4 | |
| # End of the bytecode listing | |
| # Listing of Upvalue refs (see lua doc about that) | |
| # Each upvalue is a 16-bit word | |
| base = off | |
| while off < base + self.numuv*2: | |
| self.uvdata.append(struct.unpack("<H", buff[off:off+2])[0]) # TODO verify endianness | |
| off += 2 | |
| base = off | |
| # End of the upvalue listing | |
| # Now we have to handle constants | |
| # We will create KGCs based on their type here | |
| # First, we get kgc's type | |
| # Check https://github.com/LuaJit/LuaJIT/blob/master/src/lj_bcread.c at line 244 | |
| for i in range(0, self.numkgc): | |
| if len(buff[base:]) == 0: | |
| self.kgc.append(Kgc(Kgc.KGC_UNKNOWN,"")) | |
| continue | |
| uleb_buff_size = min([len(buff[base:]), MAX_ULEB_SIZE]) | |
| kgc_type, bytes_read = read_uleb128(buff[base:base+uleb_buff_size]) | |
| base += bytes_read | |
| kgc_var = None | |
| # If the type is >= than KGC_STR, then it is a string and its length is the type minus KGC_STR | |
| if kgc_type >= Kgc.KGC_STR: | |
| kgc_len = kgc_type - Kgc.KGC_STR | |
| kgc_string = buff[base:base+kgc_len] | |
| base += kgc_len | |
| kgc_var = Kgc(kgc_type, kgc_string) | |
| elif kgc_type == Kgc.KGC_TAB: | |
| # Here we read a karray | |
| uleb_buff_size = min([len(buff[base:]), MAX_ULEB_SIZE]) | |
| narray, bytes_read = read_uleb128(buff[base:base+uleb_buff_size]) | |
| base += bytes_read | |
| uleb_buff_size = min([len(buff[base:]), MAX_ULEB_SIZE]) | |
| nhash, bytes_read = read_uleb128(buff[base:base+uleb_buff_size]) | |
| base += bytes_read | |
| ktab = {} | |
| karray = [] | |
| khash = [] | |
| for i in range(0, narray): | |
| val_type, value, bytes_read = self.parseKtabk(buff[base:]) | |
| karray.append({"type": val_type, "value": value}) | |
| base += bytes_read | |
| for i in range(0, nhash): | |
| key_type, key, bytes_read = self.parseKtabk(buff[base:]) | |
| base += bytes_read | |
| # No null index. This should not happen on a well-formed BCDump | |
| if key_type == Kgc.KTAB_NIL or key_type == Kgc.KTAB_FALSE or key_type == Kgc.KTAB_TRUE: | |
| key = "null_key" | |
| val_type, value, bytes_read = self.parseKtabk(buff[base:]) | |
| base += bytes_read | |
| khash.append({"type": val_type, "key": key, "value": value}) | |
| ktab = {"karray": karray, "khash": khash} | |
| kgc_var = Kgc(kgc_type, ktab) | |
| elif kgc_type != Kgc.KGC_CHILD: | |
| # TODO As this is only possible if FFI is activated, I didn't implemented it yet | |
| print("Warn! Something is not implemented here, could crash or yield incorrect results") | |
| kgc_var = Kgc(kgc_type, "") | |
| else: | |
| # Here we assume that kgc_type == Kgc.KGC_CHILD | |
| # TODO I'm not sure, but it seems this type is dedicated to embed protos as constants | |
| #print("Warn! Something is not implemented here, could crash or yield incorrect results") | |
| kgc_var = Kgc(kgc_type, "") | |
| self.kgc.append(kgc_var) | |
| # NOTE the 2 last cases will break the lexer if they happen, in case of crash, add the right parsing. My guess is that these are not common | |
| # Pfiou! End of kgc parsing | |
| # Let's do knum parsing | |
| for i in range(0, self.numkn): | |
| isnum = buff[base] & 1 | |
| lo, bytes_read = read_uleb128_33(buff[base:]) | |
| base += bytes_read | |
| if isnum != 0: | |
| hi, bytes_read = read_uleb128(buff[base:]) | |
| base += bytes_read | |
| self.knum.append(struct.unpack('d', struct.pack('I',lo)+struct.pack('I',hi))[0]) | |
| else: | |
| self.knum.append(lo) | |
| self.kgc = list(reversed(self.kgc)) | |
| self.knum = list(reversed(self.knum)) | |
| def toString(self): | |
| """ | |
| Dumps a proto object to string | |
| """ | |
| outStr = "---- Proto ----\n" | |
| outStr += "Flags: " | |
| if self.flags & GCProto.PROTO_CHILD != 0: | |
| outStr += "PROTO_CHILD " | |
| if self.flags & GCProto.PROTO_VARARG != 0: | |
| outStr += "PROTO_VARARG " | |
| if self.flags & GCProto.PROTO_FFI != 0: | |
| outStr += "PROTO_FFI " | |
| if self.flags & GCProto.PROTO_NOJIT != 0: | |
| outStr += "PROTO_NOJIT " | |
| if self.flags & GCProto.PROTO_ILOOP != 0: | |
| outStr += "PROTO_ILOOP " | |
| outStr += "\n" | |
| outStr += "Number of parameters: %d\n" % self.numparams | |
| outStr += "Frame size: %d\n" % self.framesize | |
| outStr += "Number of upvalues: %d\n" % self.numuv | |
| outStr += "Number of collectable constants: %d\n" % self.numkgc | |
| outStr += "Number of numeric constants: %d\n" % self.numkn | |
| outStr += "Number of bytecode instructions: %d\n" % self.numbc | |
| if self.debuglen > 0: | |
| outStr += "Debug firstline-numline: %d-%d\n" % (self.debug_firstline, self.debug.numline) | |
| if self.numbc > 0: | |
| outStr += "Bytecode dump: \n" | |
| outStr += ByteCode.listBC(self.bcins, self.kgc, self.knum) | |
| #for i in range(0, self.numbc): | |
| # outStr += ("%03d\t" % (i+1)) + hexd(self.bcins[i]) + "\n" | |
| if self.numuv > 0: | |
| outStr += "UVData dump: \n" | |
| for i in range(0, self.numuv): | |
| outStr += ("%03d\t" % (i+1)) + "0x %04x" % self.uvdata[i] + "\n" | |
| outStr += "KGC Vars: \n" | |
| for i in range(0, len(self.kgc)): | |
| if self.kgc[i] is not None: | |
| outStr += "%03d\t%s\n" % (i, self.kgc[i].toStr()) | |
| if self.numkn > 0: | |
| outStr += "KNum Vars: \n" | |
| for i in range(0, self.numkn): | |
| if type(self.knum[i]) is float : | |
| outStr += "%03d\t%f\n" % (i, self.knum[i]) | |
| elif type(self.knum[i]) is int: | |
| outStr += "%03d\t%d\n" % (i, self.knum[i]) | |
| return outStr | |
| class BCDump: | |
| """ | |
| Represents the full bytecode dump (whole file) | |
| """ | |
| # From: https://github.com/LuaJit/LuaJIT/blob/master/src/lj_bcdump.h | |
| # Doc: http://wiki.luajit.org/Bytecode-2.0#luajit-2-0-bytecode-dump-format | |
| # Header Flags | |
| F_BE = 0x01 | |
| F_STRIP = 0x02 # Debug flag (roughly) | |
| F_FFI = 0x04 # Does the dump depend on FFI? | |
| def __init__(self): | |
| # Creates a new empty BCDump object | |
| self.protos = [] # List of the protos (function blocks) | |
| self.version = None # Bytecode version (1 in most of the cases) | |
| self.flags = 0x00 # Dump flags | |
| self.name = None # Dump name | |
| self.cleanEnd = False # Did the lexer do the job properly? | |
| self.f_strip = True # Shortcut to self.flags & F_STRIP | |
| def getVersion(self): | |
| """ | |
| Returns the version number | |
| """ | |
| return self.version | |
| def getFlags(self): | |
| """ | |
| Returns the flags | |
| """ | |
| return self.flags | |
| def flagsToStr(self): | |
| """ | |
| Returns the flags as string listing for human reading | |
| """ | |
| str_flag = "" | |
| if self.flags & BCDump.F_BE != 0: | |
| str_flag += 'F_BE ' | |
| if self.flags & BCDump.F_STRIP != 0: | |
| str_flag += 'F_STRIP ' | |
| if self.flags & BCDump.F_FFI != 0: | |
| str_flag += 'F_FFI ' | |
| return str_flag | |
| def getName(self): | |
| """ | |
| Returns th dump's name | |
| """ | |
| return self.name | |
| def getProtos(self): | |
| """ | |
| Returns the list of protos | |
| """ | |
| return self.protos | |
| def isEndClean(self): | |
| """ | |
| Returns if the lexer ended successfully | |
| """ | |
| return self.cleanEnd | |
| def parseFile(self, bin_file): | |
| """ | |
| Parses an input file as a BC Dump | |
| """ | |
| # First check the magic bytes and return if wrong format | |
| first_bytes = bin_file.read(3) | |
| if first_bytes != b'\x1bLJ': | |
| print("Not a luaJIT file (wrong magic bytes)!") | |
| return | |
| # Get basic information from dump header | |
| self.version = struct.unpack("B", bin_file.read(1))[0] | |
| self.flags = struct.unpack("B", bin_file.read(1))[0] | |
| buff = b'' | |
| nameLength = 0 | |
| # If debug symbols are in file, we have a name | |
| if self.flags & BCDump.F_STRIP == 0: | |
| self.f_strip = False | |
| buff = bin_file.read(MAX_ULEB_SIZE) | |
| tmp = read_uleb128(buff) | |
| nameLength = tmp[0] | |
| i = tmp[1] | |
| name = '' | |
| if nameLength >= len(buff[i:]): | |
| name = buff[i:] + bin_file.read(nameLength-len(buff[i:])) | |
| buff = b'' | |
| self.name = name.decode('ascii') # Which encoding is really used? This is not specified | |
| else: | |
| self.name = buff[i:nameLength+1].decode('ascii') # Same as above | |
| buff = buff[nameLength+1:] | |
| # We finished reading the header, let's get all the protos | |
| still_has_proto = True | |
| proto_number = 0 | |
| buff = bin_file.read(MAX_ULEB_SIZE-len(buff)) | |
| while still_has_proto: | |
| if len(buff) < MAX_ULEB_SIZE: | |
| buff = buff + bin_file.read(MAX_ULEB_SIZE-len(buff)) | |
| # The first part of a proto is its length | |
| tmp, bytes_read = read_uleb128(buff) | |
| # If we reach the end of the file before being able to retrieve the announced number of protos | |
| if len(buff) == 0 or tmp == 0: | |
| still_has_proto = False | |
| break | |
| proto_size = tmp | |
| bytes_offset = bytes_read | |
| proto_number += 1 | |
| # Retrieval of proto bytes | |
| if proto_size > len(buff[bytes_offset:]): | |
| proto = buff[bytes_offset:] + bin_file.read(proto_size-len(buff[bytes_offset:])) | |
| buff = b'' | |
| else: | |
| proto = buff[bytes_offset:bytes_offset+proto_size] | |
| buff = buff[proto_size+bytes_offset:] | |
| # Initialize the proto object | |
| obj_proto = GCProto(self.f_strip) | |
| obj_proto.parseFromBuff(proto) | |
| self.protos.append(obj_proto) | |
| # If we only have a null byte left, the job is finished | |
| if buff == b'\x00': | |
| self.cleanEnd = True | |
| if len(sys.argv) != 2: | |
| print("Usage: %s <lua_file>" % sys.argv[0]) | |
| sys.exit() | |
| bin_file = open(sys.argv[1], "rb") | |
| bcdump = BCDump() | |
| bcdump.parseFile(bin_file) | |
| if bcdump.getVersion() is None: | |
| sys.exit() | |
| print("Bytecode version: %d" % bcdump.getVersion()) | |
| print("Flags: %s" % bcdump.flagsToStr()) | |
| if bcdump.getName() is not None: | |
| print("File has a name: %s" % bcdump.getName()) | |
| i = 1 | |
| for proto in bcdump.getProtos(): | |
| print("------------ Proto %d -------------" % i) | |
| print(proto.toString()) | |
| print() | |
| i += 1 | |
| if bcdump.isEndClean(): | |
| print("Clean end") |
Thank you for your response.
We are finding solutions to edit only strings (in byecode LuaJIT file) and save. Could you please help? We could not pm in Twitter, it seems your account can't be messaged.
------------ Proto 2 -------------
Traceback (most recent call last):
File "/Users/brandonros/Desktop/disassemble-luajit-v1.py", line 745, in <module>
print(proto.toString())
File "/Users/brandonros/Desktop/disassemble-luajit-v1.py", line 582, in toString
outStr += "%03d\t%s\n" % (i, self.kgc[i].toStr())
File "/Users/brandonros/Desktop/disassemble-luajit-v1.py", line 341, in toStr
outStr += self.value.decode('ascii')
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 0: ordinal not in range(128)
Changed ascii code to latin1 decoding codec, got further.
------------ Proto 4 -------------
Traceback (most recent call last):
File "/Users/brandonros/Desktop/disassemble-luajit-v1.py", line 745, in <module>
print(proto.toString())
File "/Users/brandonros/Desktop/disassemble-luajit-v1.py", line 570, in toString
outStr += ByteCode.listBC(self.bcins, self.kgc, self.knum)
File "/Users/brandonros/Desktop/disassemble-luajit-v1.py", line 199, in listBC
val = knum[struct.unpack("<H", ins[2:4])[0]]
IndexError: list index out of range
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Hi @anzteam,
I wrote a post giving more context on LuaJIT disassembly, you can find it here: https://www.mickaelwalter.fr/reverse-engineering-luajit/
If you still have questions you can get in touch with me on Twitter: https://www.twitter.com/MickaelWalter/
Just a word of warning, I didn't work on any LuaJIT decompilation or compilation. Only on reading the Bytecode and understand how it is interpreted.