C / C++ / MFC

jtasph wrote:

I don't know what's the meaning of "0x33, 0xC0, 0xC2, 0x04, 0x00". Who does understand the code?

__asm
{
	xor eax,eax
	ret 0x4
}

jtasph wrote:

Do you know what's the meaning of these assembly codes and how the codes to disable the SetUnhandledExceptionFilter function called by CRT?

jtasph wrote:

Do these assembly codes depend on platform?

Randor wrote:

They are like the dinosaurs and are nearly extinct.

Rajesh R Subramanian wrote:

I thought the dinosaurs *are* extinct.

CPallini wrote:

Norton

jtasph wrote:

I don't know what's the meaning of "0x33, 0xC0, 0xC2, 0x04, 0x00".

Naveen wrote:

However I suspect the necessity of supressing the CRT exception trough the above method. I guess the you can use the _set_abort_behavior() to control the exception handler of CRT.

There're 3 kinds of checks in CRT code that pass around and invoke Dr.Watson directly. 
1.One is when we have detected a buffer overrun (/GS failure). For security reasons in this case, we directly call the UnhandledExceptionFilter. 
2.Another is when we detect an invalid parameter before a bad situation occurs. 
3.A third are other abnormal terminations (purecall, unexpected, etc). These generally have their own handlers that you can set (_set_purecall, _set_terminate, _set_unexpected). These exist only in cases where we consider it safe to do so. 

_set_abort_behavior, signal(SIGABRT, ...), and _set_invalid_parameter_handler(...) functions allow to intercept in case 2 and case 3. But for case 1, we can set api hook.  

jtasph wrote:

functions allow to intercept in case 2 and case 3. But for case 1, we can set api hook.

jtasph wrote:

In addition, when I debug the code to catch exception, a exception dialog will ask me "Abort, Retry or Ignore". If I select "Abort" or "Ignore', my defined exception funciton will not call.

SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX);

LONG WINAPI MyUnFilterA (struct _EXCEPTION_POINTERS *lpExceptionInfo)
{
    AfxMessageBox(_T("11"));
    return EXCEPTION_CONTINUE_SEARCH;
}

1.
void CExceptionDlg::OnBnClickedOk()
{
    SetUnhandledExceptionFilter(MyUnFilterA);
    DisableSetUnhandledExceptionFilter();
    *(int *) 0 = 0;
}
2.
void CExceptionDlg::OnBnClickedOk()
{
    SetUnhandledExceptionFilter(MyUnFilterA);
    DisableSetUnhandledExceptionFilter();
    abort();
}
3.
void CExceptionDlg::OnBnClickedOk()
{
    AddVectoredExceptionHandler(1, MyUnFilterA);
    *(int *) 0 = 0;
}
4.
void CExceptionDlg::OnBnClickedOk()
{
    AddVectoredExceptionHandler(1, MyUnFilterA);
    abort();
}

CStdioFile FileData;
    CString chLine;
    if( !FileData.Open( csFilePath_i, CFile::modeRead  ))
    {
         return;
    }
    FileData.SeekToBegin();
    //Get each lines from the file
    while (FileData.ReadString(chLine))
    {
        _stscanf(chLine, "%lf %lf %lf\n", &a, &b, &c);
    }

Nicholas Amh wrote:

_tscanf(f1_txt, "%lf %lf %lf\n", &a, &b, &c);