C++ Ptr::isWritten方法代码示例

bool IA_x86Details::isTableInsn(Instruction::Ptr i) 
{
  Expression::Ptr jumpExpr = currentBlock->curInsn()->getControlFlowTarget();
  parsing_printf("jumpExpr for table insn is %s\n", jumpExpr->format().c_str());
  if(i->getOperation().getID() == e_mov && i->readsMemory() && i->isWritten(jumpExpr))
  {
    return true;
  }
  if(i->getOperation().getID() == e_lea && i->isWritten(jumpExpr))
  {
    return true;
  }
  return false;
}

bool IA_IAPI::isFrameSetupInsn(Instruction::Ptr i) const
{
    if(i->getOperation().getID() == e_mov)
    {
        if(i->readsMemory() || i->writesMemory())
        {
            parsing_printf("%s[%d]: discarding insn %s as stack frame preamble, not a reg-reg move\n",
                           FILE__, __LINE__, i->format().c_str());
            //return false;
        }
        if(i->isRead(stackPtr[_isrc->getArch()]) &&
           i->isWritten(framePtr[_isrc->getArch()]))
        {
            if((unsigned) i->getOperand(0).getValue()->size() == _isrc->getAddressWidth())
            {
                return true;
            }
            else
            {
                parsing_printf("%s[%d]: discarding insn %s as stack frame preamble, size mismatch for %d-byte addr width\n",
                               FILE__, __LINE__, i->format().c_str(), _isrc->getAddressWidth());
            }
        }
    }
    return false;
}

/* returns true if the call leads to:
 * -an invalid instruction (or immediately branches/calls to an invalid insn)
 * -a block not ending in a return instruction that pops the return address 
 *  off of the stack
 */
bool IA_IAPI::isFakeCall() const
{
    assert(_obj->defensiveMode());

    if (isDynamicCall()) {
        return false;
    }

    // get func entry
    bool tampers = false;
    bool valid; Address entry;
    boost::tie(valid, entry) = getCFT();

    if (!valid) return false;

    if (! _cr->contains(entry) ) {
       return false;
    }

    if ( ! _isrc->isCode(entry) ) {
        mal_printf("WARNING: found function call at %lx "
                   "to invalid address %lx %s[%d]\n", current, 
                   entry, FILE__,__LINE__);
        return false;
    }

    // get instruction at func entry
    const unsigned char* bufPtr =
     (const unsigned char *)(_cr->getPtrToInstruction(entry));
    Offset entryOff = entry - _cr->offset();
    InstructionDecoder newdec( bufPtr,
                              _cr->length() - entryOff,
                              _cr->getArch() );
    IA_IAPI *ah = new IA_IAPI(newdec, entry, _obj, _cr, _isrc, _curBlk);
    Instruction::Ptr insn = ah->curInsn();

    // follow ctrl transfers until you get a block containing non-ctrl 
    // transfer instructions, or hit a return instruction
    while (insn->getCategory() == c_CallInsn ||
           insn->getCategory() == c_BranchInsn) 
    {
       boost::tie(valid, entry) = ah->getCFT();
       if ( !valid || ! _cr->contains(entry) || ! _isrc->isCode(entry) ) {
          mal_printf("WARNING: found call to function at %lx that "
                     "leaves to %lx, out of the code region %s[%d]\n", 
                     current, entry, FILE__,__LINE__);
          return false;
       }
        bufPtr = (const unsigned char *)(_cr->getPtrToInstruction(entry));
        entryOff = entry - _cr->offset();
        delete(ah);
        newdec = InstructionDecoder(bufPtr, 
                                    _cr->length() - entryOff, 
                                    _cr->getArch());
        ah = new IA_IAPI(newdec, entry, _obj, _cr, _isrc, _curBlk);
        insn = ah->curInsn();
    }

    // calculate instruction stack deltas for the block, leaving the iterator
    // at the last ins'n if it's a control transfer, or after calculating the 
    // last instruction's delta if we run off the end of initialized memory
    int stackDelta = 0;
    int addrWidth = _isrc->getAddressWidth();
    static Expression::Ptr theStackPtr
        (new RegisterAST(MachRegister::getStackPointer(_isrc->getArch())));
    Address curAddr = entry;

    while(true) {

        // exit condition 1
        if (insn->getCategory() == c_CallInsn ||
            insn->getCategory() == c_ReturnInsn ||
            insn->getCategory() == c_BranchInsn) 
        {
            break;
        }

        // calculate instruction delta
        if(insn->isWritten(theStackPtr)) {
            entryID what = insn->getOperation().getID();
            int sign = 1;
            switch(what) 
            {
            case e_push:
                sign = -1;
                //FALLTHROUGH
            case e_pop: {
                int size = insn->getOperand(0).getValue()->size();
                stackDelta += sign * size;
                break;
            }
            case e_pusha:
            case e_pushad:
                sign = -1;
                //FALLTHROUGH
//.........这里部分代码省略.........

//.........这里部分代码省略.........
       callee != context &&
       target &&
       !context->contains(target)
       )
    {
      parsing_printf("\tjump to 0x%lx, TAIL CALL\n", addr);
      tailCalls[type] = true;
      return true;
    }

    if (curInsn()->getCategory() == c_BranchInsn &&
            valid &&
            !callee) {
	if (target) {
	    parsing_printf("\tjump to 0x%lx is known block, but not func entry, NOT TAIL CALL\n", addr);
	    tailCalls[type] = false;
	    return false;
	} else if (knownTargets.find(addr) != knownTargets.end()) {
	    parsing_printf("\tjump to 0x%lx is known target in this function, NOT TAIL CALL\n", addr);
	    tailCalls[type] = false;
	    return false;
	}
    }

    if(allInsns.size() < 2) {
      if(context->addr() == _curBlk->start() && curInsn()->getCategory() == c_BranchInsn)
      {
	parsing_printf("\tjump as only insn in entry block, TAIL CALL\n");
	tailCalls[type] = true;
	return true;
      }
      else
      {
        parsing_printf("\ttoo few insns to detect tail call\n");
        context->obj()->cs()->incrementCounter(PARSE_TAILCALL_FAIL);
        tailCalls[type] = false;
        return false;
      }
    }

    if ((curInsn()->getCategory() == c_BranchInsn))
    {
        //std::map<Address, Instruction::Ptr>::const_iterator prevIter =
                //allInsns.find(current);
        
        // Updated: there may be zero or more nops between leave->jmp
       
        allInsns_t::const_iterator prevIter = curInsnIter;
        --prevIter;
        Instruction::Ptr prevInsn = prevIter->second;
    
        while ( isNopInsn(prevInsn) && (prevIter != allInsns.begin()) ) {
           --prevIter;
           prevInsn = prevIter->second;
        }
	prevInsn = prevIter->second;
        if(prevInsn->getOperation().getID() == e_leave)
        {
           parsing_printf("\tprev insn was leave, TAIL CALL\n");
           tailCalls[type] = true;
           return true;
        }
        else if(prevInsn->getOperation().getID() == e_pop)
        {
            if(prevInsn->isWritten(framePtr[_isrc->getArch()]))
            {
                parsing_printf("\tprev insn was %s, TAIL CALL\n", prevInsn->format().c_str());
                tailCalls[type] = true;
                return true;
            }
        }
        else if(prevInsn->getOperation().getID() == e_add)
        {			
            if(prevInsn->isWritten(stackPtr[_isrc->getArch()]))
            {
				bool call_fallthrough = false;
				if (_curBlk->start() == prevIter->first) {				
					for (auto eit = _curBlk->sources().begin(); eit != _curBlk->sources().end(); ++eit) {						
						if ((*eit)->type() == CALL_FT) {
							call_fallthrough = true;
							break;
						}
					}
				}
				if (call_fallthrough) {
					parsing_printf("\tprev insn was %s, but it is the next instruction of a function call, not a tail call %x %x\n", prevInsn->format().c_str()); 
				}	else {
					parsing_printf("\tprev insn was %s, TAIL CALL\n", prevInsn->format().c_str());
					tailCalls[type] = true;
					return true;
				}
			} else
				parsing_printf("\tprev insn was %s, not tail call\n", prevInsn->format().c_str());
        }
    }

    tailCalls[type] = false;
    context->obj()->cs()->incrementCounter(PARSE_TAILCALL_FAIL);
    return false;
}