#!/usr/bin/env python #-*- coding:utf-8 -*- import re import miasm2.expression.expression as m2_expr import miasm2.core.asmbloc as asmbloc from miasm2.core.cpu import gen_base_expr, parse_ast from miasm2.core.cpu import instruction declarator = {'byte': 8, 'word': 16, 'dword': 32, 'qword': 64, 'long': 32, } size2pck = {8: 'B', 16: 'H', 32: 'I', 64: 'Q', } EMPTY_RE = re.compile(r'\s*$') COMMENT_RE = re.compile(r'\s*;\S*') LOCAL_LABEL_RE = re.compile(r'\s*(\.L\S+)\s*:') DIRECTIVE_START_RE = re.compile(r'\s*\.') DIRECTIVE_RE = re.compile(r'\s*\.(\S+)') LABEL_RE = re.compile(r'\s*(\S+)\s*:') FORGET_LABEL_RE = re.compile(r'\s*\.LF[BE]\d\s*:') class Directive(object): """Stand for Directive""" pass class DirectiveAlign(Directive): """Stand for alignment representation""" def __init__(self, alignment=1): self.alignment = alignment def __str__(self): return "Alignment %s" % self.alignment class DirectiveSplit(Directive): """Stand for alignment representation""" pass class DirectiveDontSplit(Directive): """Stand for alignment representation""" pass def guess_next_new_label(symbol_pool): """Generate a new label @symbol_pool: the asm_symbol_pool instance""" i = 0 gen_name = "loc_%.8X" while True: name = gen_name % i label = symbol_pool.getby_name(name) if label is None: return symbol_pool.add_label(name) i += 1 def replace_expr_labels(expr, symbol_pool, replace_id): """Create asm_label of the expression @expr in the @symbol_pool Update @replace_id""" if not (isinstance(expr, m2_expr.ExprId) and isinstance(expr.name, asmbloc.asm_label)): return expr old_lbl = expr.name new_lbl = symbol_pool.getby_name_create(old_lbl.name) replace_id[expr] = m2_expr.ExprId(new_lbl, expr.size) return replace_id[expr] def replace_orphan_labels(instr, symbol_pool): """Link orphan labels used by @instr to the @symbol_pool""" for i, arg in enumerate(instr.args): replace_id = {} arg.visit(lambda e: replace_expr_labels(e, symbol_pool, replace_id)) instr.args[i] = instr.args[i].replace_expr(replace_id) STATE_NO_BLOC = 0 STATE_IN_BLOC = 1 def parse_txt(mnemo, attrib, txt, symbol_pool=None): """Parse an assembly listing. Returns a couple (blocks, symbol_pool), where blocks is a list of asm_bloc and symbol_pool the associated asm_symbol_pool @mnemo: architecture used @attrib: architecture attribute @txt: assembly listing @symbol_pool: (optional) the asm_symbol_pool instance used to handle labels of the listing """ if symbol_pool is None: symbol_pool = asmbloc.asm_symbol_pool() C_NEXT = asmbloc.asm_constraint.c_next C_TO = asmbloc.asm_constraint.c_to lines = [] # parse each line for line in txt.split('\n'): # empty if EMPTY_RE.match(line): continue # comment if COMMENT_RE.match(line): continue # labels to forget if FORGET_LABEL_RE.match(line): continue # label beginning with .L match_re = LABEL_RE.match(line) if match_re: label_name = match_re.group(1) label = symbol_pool.getby_name_create(label_name) lines.append(label) continue # directive if DIRECTIVE_START_RE.match(line): match_re = DIRECTIVE_RE.match(line) directive = match_re.group(1) if directive in ['text', 'data', 'bss']: continue if directive in ['string', 'ascii']: # XXX HACK line = line.replace(r'\n', '\n').replace(r'\r', '\r') raw = line[line.find(r'"') + 1:line.rfind(r'"')] raw = raw.decode('string_escape') if directive == 'string': raw += "\x00" lines.append(asmbloc.asm_raw(raw)) continue if directive == 'ustring': # XXX HACK line = line.replace(r'\n', '\n').replace(r'\r', '\r') raw = line[line.find(r'"') + 1:line.rfind(r'"')] + "\x00" raw = raw.decode('string_escape') raw = "".join([string + '\x00' for string in raw]) lines.append(asmbloc.asm_raw(raw)) continue if directive in declarator: data_raw = line[match_re.end():].split(' ', 1)[1] data_raw = data_raw.split(',') size = declarator[directive] expr_list = [] # parser base_expr = gen_base_expr()[2] my_var_parser = parse_ast(lambda x: m2_expr.ExprId(x, size), lambda x: m2_expr.ExprInt(x, size)) base_expr.setParseAction(my_var_parser) for element in data_raw: element = element.strip() element_expr = base_expr.parseString(element)[0] expr_list.append(element_expr.canonize()) raw_data = asmbloc.asm_raw(expr_list) raw_data.element_size = size lines.append(raw_data) continue if directive == 'comm': # TODO continue if directive == 'split': # custom command lines.append(DirectiveSplit()) continue if directive == 'dontsplit': # custom command lines.append(DirectiveDontSplit()) continue if directive == "align": align_value = int(line[match_re.end():], 0) lines.append(DirectiveAlign(align_value)) continue if directive in ['file', 'intel_syntax', 'globl', 'local', 'type', 'size', 'align', 'ident', 'section']: continue if directive[0:4] == 'cfi_': continue raise ValueError("unknown directive %s" % str(directive)) # label match_re = LABEL_RE.match(line) if match_re: label_name = match_re.group(1) label = symbol_pool.getby_name_create(label_name) lines.append(label) continue # code if ';' in line: line = line[:line.find(';')] line = line.strip(' ').strip('\t') instr = mnemo.fromstring(line, attrib) # replace orphan asm_label with labels from symbol_pool replace_orphan_labels(instr, symbol_pool) if instr.dstflow(): instr.dstflow2label(symbol_pool) lines.append(instr) asmbloc.log_asmbloc.info("___pre asm oki___") # make blocks cur_block = None state = STATE_NO_BLOC i = 0 blocks = asmbloc.BasicBlocks() block_to_nlink = None block_may_link = False delayslot = 0 while i < len(lines): if delayslot: delayslot -= 1 if delayslot == 0: state = STATE_NO_BLOC line = lines[i] # no current block if state == STATE_NO_BLOC: if isinstance(line, DirectiveDontSplit): block_to_nlink = cur_block i += 1 continue elif isinstance(line, DirectiveSplit): block_to_nlink = None i += 1 continue elif not isinstance(line, asmbloc.asm_label): # First line must be a label. If it's not the case, generate # it. label = guess_next_new_label(symbol_pool) cur_block = asmbloc.asm_bloc(label, alignment=mnemo.alignment) else: cur_block = asmbloc.asm_bloc(line, alignment=mnemo.alignment) i += 1 # Generate the current bloc blocks.add_node(cur_block) state = STATE_IN_BLOC if block_to_nlink: block_to_nlink.addto( asmbloc.asm_constraint(cur_block.label, C_NEXT)) block_to_nlink = None continue # in block elif state == STATE_IN_BLOC: if isinstance(line, DirectiveSplit): state = STATE_NO_BLOC block_to_nlink = None elif isinstance(line, DirectiveDontSplit): state = STATE_NO_BLOC block_to_nlink = cur_block elif isinstance(line, DirectiveAlign): cur_block.alignment = line.alignment elif isinstance(line, asmbloc.asm_raw): cur_block.addline(line) block_to_nlink = cur_block elif isinstance(line, asmbloc.asm_label): if block_to_nlink: cur_block.addto( asmbloc.asm_constraint(line, C_NEXT)) block_to_nlink = None state = STATE_NO_BLOC continue # instruction elif isinstance(line, instruction): cur_block.addline(line) block_to_nlink = cur_block if not line.breakflow(): i += 1 continue if delayslot: raise RuntimeError("Cannot have breakflow in delayslot") if line.dstflow(): for dst in line.getdstflow(symbol_pool): if not isinstance(dst, m2_expr.ExprId): continue if dst in mnemo.regs.all_regs_ids: continue cur_block.addto(asmbloc.asm_constraint(dst.name, C_TO)) if not line.splitflow(): block_to_nlink = None delayslot = line.delayslot + 1 else: raise RuntimeError("unknown class %s" % line.__class__) i += 1 for block in blocks: # Fix multiple constraints block.fix_constraints() # Log block asmbloc.log_asmbloc.info(block) return blocks, symbol_pool