Re: Error diagnosis

From:

"SteveB" <steve.brett@callcredit.plc.uk>

Newsgroups:

microsoft.public.vc.language

Date:

28 Nov 2006 05:34:38 -0800

Message-ID:

<1164720878.796630.28280@j72g2000cwa.googlegroups.com>

Igor Tandetnik wrote:

"SteveB" <steve.brett@callcredit.plc.uk> wrote in message
news:1164623654.804316.16160@n67g2000cwd.googlegroups.com

We have an app that was written a few years ago in which the
developers wrote an entire exception handling system.

I have a problem with the following line if code:

OutStream << L" (+ " << std::dec <<
static_cast<DWORD>(Disp64) << L" bytes), ";

This is throwing the following exception:

Run-Time Check Failure #2 - Stack around the variable 'stIHM' was
corrupted.

This error usually indicates a buffer overflow, when the buffer is
allocated on the stack.

What makes you think it's this particular line of code that causes the
problem? How is OutStream declared? What's stIHM, and what other
variables are declared nearby?
--
With best wishes,
Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925

Thanks for your reply Igor.

I did actually understand what the line of code was doing (for the
benefit of other people that replied).

To answer your questions:
If I add a breakpoint on this line of code the exception is thrown when
I step over it.

stIHM is declared thus:
TWindowStruct<IMAGEHLP_MODULE64> stIHM ;

OutStream is declared as:
std::wostringstream OutStream;

The whole function is declared below:

std::wstring CStackTrace::ConvertAddress64(DWORD64 Address)
{
    HANDLE hProcess = GetCurrentProcess();

    // Prepare a large IMAGEHLP_SYMBOL with space for the name
    // Can't use a TWindowStruct due to the presence of the variable
name buffer
    char szTemp [ MAX_PATH + sizeof ( IMAGEHLP_SYMBOL64 ) ] ;
    PIMAGEHLP_SYMBOL64 pIHS = (PIMAGEHLP_SYMBOL64)&szTemp ;
    ZeroMemory ( pIHS , MAX_PATH + sizeof ( IMAGEHLP_SYMBOL64 ) ) ;

    pIHS->SizeOfStruct = sizeof ( IMAGEHLP_SYMBOL64 ) ;
    pIHS->Address = Address ;
    pIHS->MaxNameLength = MAX_PATH ;

   TWindowStruct<IMAGEHLP_MODULE64> stIHM ;
    std::wostringstream OutStream;

    // Always stick the address in first.
    OutStream << L"0x" << std::hex << std::setfill(L'0') <<
std::setw(8) << static_cast<DWORD>(Address) << L" ";

    // Get the module name.
    if ( SymGetModuleInfo64( hProcess, Address, &stIHM ) )
    {
        // Strip off the path.
        LPSTR szName = strrchr( stIHM.ImageName , '\\' ) ;
        if ( NULL != szName )
            ++szName;
        else
            szName = stIHM.ImageName ;

        OutStream << CDCLib::Utilities::ConvertAnsiToUnicode(szName) <<
L", ";
    }
    else
    {
#ifdef _DEBUG // Just for those debugging
        DWORD dw = GetLastError();
#endif
        OutStream << L"<unknown module>, ";
    }

    // Get the function.
    DWORD64 Disp64 ;
    if ( SymGetSymFromAddr64 ( hProcess, Address , &Disp64 , pIHS ) )
    {
        OutStream <<
CDCLib::Utilities::ConvertAnsiToUnicode(pIHS->Name);
        if ( 0 != Disp64 )
            OutStream << L" (+ " << std::dec <<
static_cast<DWORD>(Disp64) << L" bytes), ";

        // If I got a symbol, give the source and line a whirl.
        TWindowStruct<IMAGEHLP_LINE64> stIHL ;
        DWORD Disp;

        if ( 0 != SymGetLineFromAddr64(hProcess, Address, &Disp,
&stIHL) )
        {
            // Strip off the path.
            LPSTR szName = strrchr( stIHL.FileName , '\\' ) ;
            if ( NULL != szName )
                szName++ ;
            else
                szName = stIHL.FileName ;
            OutStream <<
ABCLib::Utilities::ConvertAnsiToUnicode(szName) << L", Line " <<
stIHL.LineNumber;
            if ( 0 != Disp )
                OutStream << L" (+ " << std::dec << Disp << L" bytes)";
        }
    }
    else
    {
#ifdef _DEBUG // Just for those debugging
        DWORD dw = GetLastError();
#endif
        OutStream << L"<unknown symbol>";
    }

    // Tack on a CRLF.
    OutStream << L"\r\n";
    return OutStream.str();
}

many thanks

Steve