如何在内核下获得操作系统当前登陆用户名

  搜了下网页，有这个方法
BOOLEAN GetUserName(PSECURITY_SUBJECT_CONTEXT securitySubjectContext, PUNICODE_STRING userName)
{
  PACCESS_TOKEN token;
  LUID luid;
  PSecurityUserData userInformation = NULL;
  NTSTATUS status;

  //初始化userName
  userName->Length = 0;
  userName->MaximumLength = 0;
  userName->Buffer = NULL;

  //取token
  token = SeQuerySubjectContextToken(securitySubjectContext);

  //根据token查询用户的LUID
  status = SeQueryAuthenticationIdToken(token, &luid);
  if (!NT_SUCCESS(status))
  {
    KdPrint(("GetUserName(): SeQueryAuthenticationIdToken fail\n"));
    return FALSE;
  }

  //特殊情况，SYSTEM用户
  if(luid.LowPart==SYSTEMACCOUNT_LOW && luid.HighPart==SYSTEMACCOUNT_HIGH)
  {
    userName->Length = 12;
    userName->MaximumLength = 12;
    userName->Buffer = ExAllocatePool(NonPagedPool, userName->MaximumLength);
    if (userName->Buffer==NULL)
    {
        KdPrint(("GetUserName(): ExAllocatePool fail\n"));
        return FALSE;
    }

    RtlCopyMemory(userName->Buffer, SYSTEMUSER, userName->MaximumLength);

    return TRUE;
  }

  //根据用户的luid取用户名
  status = GetSecurityUserInfo(&luid, UNDERSTANDS_LONG_NAMES, &userInformation);
  if (!NT_SUCCESS(status))
  {
    KdPrint(("GetUserName(): GetSecurityUserInfo fail\n"));
    return FALSE;
  }

  userName->Length = 0;
  userName->MaximumLength = userInformation->UserName.Length;
  userName->Buffer = ExAllocatePool(NonPagedPool, userName->MaximumLength);
  if (userName->Buffer==NULL)
  {
    KdPrint(("GetUserName(): ExAllocatePool fail\n"));
    return FALSE;
  }

  RtlCopyUnicodeString(userName, &userInformation->UserName);

  LsaFreeReturnBuffer(userInformation);

  return TRUE;
}


试了下，死机！！ :(  
xp sp2