msjexhnd.cpp

//==========================================  
// Matt Pietrek  
// Microsoft Systems Journal, April 1997  
// FILE: MSJEXHND.CPP  
//==========================================  

#include< windows.h>  
#include< tchar.h>  

#include "StdAfx.h"
#include "msjexhnd.h"  
  
//============================== Global Variables =============================  
  
//  
// Declare the static variables of the MSJExceptionHandler class  
//  
TCHAR MSJExceptionHandler::m_szLogFileName[MAX_PATH];  
LPTOP_LEVEL_EXCEPTION_FILTER MSJExceptionHandler::m_previousFilter;  
HANDLE MSJExceptionHandler::m_hReportFile;  
  
  
MSJExceptionHandler g_MSJExceptionHandler;  // Declare global instance of class  
  
//============================== Class Methods =============================  
  
//=============  
// Constructor  
//=============  
MSJExceptionHandler::MSJExceptionHandler( )  
{  
   // Install the unhandled exception filter function  
    m_previousFilter = SetUnhandledExceptionFilter(MSJUnhandledExceptionFilter);  
  
   // Figure out what the report file will be named, and store it away  
    GetModuleFileName( 0, m_szLogFileName, MAX_PATH );  
  
    // Look for the '.' before the "EXE" extension.  Replace the extension  
    // with "RPT"  
    PTSTR pszDot = _tcsrchr( m_szLogFileName, _T('.') );  
    if ( pszDot )  
    {  
        pszDot++;   // Advance past the '.'  
        if ( _tcslen(pszDot) >= 3 )  
            _tcscpy( pszDot, _T("RPT") );   // "RPT" -> "Report"  
    }  
}  
  
//============  
// Destructor  
//============  
MSJExceptionHandler::~MSJExceptionHandler( )  
{  
    SetUnhandledExceptionFilter( m_previousFilter );  
}  
  
//==============================================================  
// Lets user change the name of the report file to be generated  
//==============================================================  
void MSJExceptionHandler::SetLogFileName( PTSTR pszLogFileName )  
{  
    _tcscpy( m_szLogFileName, pszLogFileName );  
}  
  
//===========================================================  
// Entry point where control comes on an unhandled exception  
//===========================================================  
LONG WINAPI MSJExceptionHandler::MSJUnhandledExceptionFilter(  
                                    PEXCEPTION_POINTERS pExceptionInfo )  
{  
    m_hReportFile = CreateFile( m_szLogFileName,  
                                GENERIC_WRITE,  
                                0,  
                                0,  
                                OPEN_ALWAYS,  
                                FILE_FLAG_WRITE_THROUGH,  
                                0 );  
  
    if ( m_hReportFile )  
    {  
        SetFilePointer( m_hReportFile, 0, 0, FILE_END );  
  
        GenerateExceptionReport( pExceptionInfo );  
  
        CloseHandle( m_hReportFile );  
        m_hReportFile = 0;  
    }  
  
    if ( m_previousFilter )  
        return m_previousFilter( pExceptionInfo );  
    else  
        return EXCEPTION_CONTINUE_SEARCH;  
}  
  
//===========================================================================  
// Open the report file, and write the desired information to it.  Called by  
// MSJUnhandledExceptionFilter                                                
//===========================================================================  
void MSJExceptionHandler::GenerateExceptionReport(  
    PEXCEPTION_POINTERS pExceptionInfo )  
{  
    // Start out with a banner  
    _tprintf( _T("//=====================================================\n") );  
  
    PEXCEPTION_RECORD pExceptionRecord = pExceptionInfo->ExceptionRecord;  
  
   // First print information about the type of fault  
    _tprintf(   _T("Exception code: %08X %s\n"),  
                pExceptionRecord->ExceptionCode,  
                GetExceptionString(pExceptionRecord->ExceptionCode) );  
  
   // Now print information about where the fault occured  
    TCHAR szFaultingModule[MAX_PATH];  
    DWORD section, offset;  
    GetLogicalAddress(  pExceptionRecord->ExceptionAddress,  
                        szFaultingModule,  
                        sizeof( szFaultingModule ),  
                        section, offset );  
  
    _tprintf( _T("Fault address:  %08X %02X:%08X %s\n"),  
                pExceptionRecord->ExceptionAddress,  
                section, offset, szFaultingModule );  
  
    PCONTEXT pCtx = pExceptionInfo->ContextRecord;  
  
   // Show the registers  
    #ifdef _M_IX86  // Intel Only!  
    _tprintf( _T("\nRegisters:\n") );  
  
    _tprintf(_T("EAX:%08X\nEBX:%08X\nECX:%08X\nEDX:%08X\nESI:%08X\nEDI:%08X\n"),  
            pCtx->Eax, pCtx->Ebx, pCtx->Ecx, pCtx->Edx, pCtx->Esi, pCtx->Edi );  
  
    _tprintf( _T("CS:EIP:%04X:%08X\n"), pCtx->SegCs, pCtx->Eip );  
    _tprintf( _T("SS:ESP:%04X:%08X  EBP:%08X\n"),  
                pCtx->SegSs, pCtx->Esp, pCtx->Ebp );  
    _tprintf( _T("DS:%04X  ES:%04X  FS:%04X  GS:%04X\n"),  
                pCtx->SegDs, pCtx->SegEs, pCtx->SegFs, pCtx->SegGs );  
    _tprintf( _T("Flags:%08X\n"), pCtx->EFlags );  
  
   // Walk the stack using x86 specific code  
    IntelStackWalk( pCtx );  
  
    #endif  
  
    _tprintf( _T("\n") );  
}  
  
//======================================================================  
// Given an exception code, returns a pointer to a static string with a  
// description of the exception                                          
//======================================================================  
LPTSTR MSJExceptionHandler::GetExceptionString( DWORD dwCode )  
{  
    #define EXCEPTION( x ) case EXCEPTION_##x: return _T(#x);  
  
    switch ( dwCode )  
    {  
        EXCEPTION( ACCESS_VIOLATION )  
        EXCEPTION( DATATYPE_MISALIGNMENT )  
        EXCEPTION( BREAKPOINT )  
        EXCEPTION( SINGLE_STEP )  
        EXCEPTION( ARRAY_BOUNDS_EXCEEDED )  
        EXCEPTION( FLT_DENORMAL_OPERAND )  
        EXCEPTION( FLT_DIVIDE_BY_ZERO )  
        EXCEPTION( FLT_INEXACT_RESULT )  
        EXCEPTION( FLT_INVALID_OPERATION )  
        EXCEPTION( FLT_OVERFLOW )  
        EXCEPTION( FLT_STACK_CHECK )  
        EXCEPTION( FLT_UNDERFLOW )  
        EXCEPTION( INT_DIVIDE_BY_ZERO )  
        EXCEPTION( INT_OVERFLOW )  
        EXCEPTION( PRIV_INSTRUCTION )  
        EXCEPTION( IN_PAGE_ERROR )  
        EXCEPTION( ILLEGAL_INSTRUCTION )  
        EXCEPTION( NONCONTINUABLE_EXCEPTION )  
        EXCEPTION( STACK_OVERFLOW )  
        EXCEPTION( INVALID_DISPOSITION )  
        EXCEPTION( GUARD_PAGE )  
        EXCEPTION( INVALID_HANDLE )  
    }  
  
    // If not one of the "known" exceptions, try to get the string  
    // from NTDLL.DLL's message table.  
  
    static TCHAR szBuffer[512] = { 0 };  
  
    FormatMessage(  FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_HMODULE,  
                    GetModuleHandle( _T("NTDLL.DLL") ),  
                    dwCode, 0, szBuffer, sizeof( szBuffer ), 0 );  
  
    return szBuffer;  
}  
  
//==============================================================================  
// Given a linear address, locates the module, section, and offset containing   
// that address.                                                                
//                                                                              
// Note: the szModule paramater buffer is an output buffer of length specified  
// by the len parameter (in characters!)                                        
//==============================================================================  
BOOL MSJExceptionHandler::GetLogicalAddress(  
        PVOID addr, PTSTR szModule, DWORD len, DWORD& section, DWORD& offset )  
{  
    MEMORY_BASIC_INFORMATION mbi;  
  
    if ( !VirtualQuery( addr,& mbi, sizeof(mbi) ) )  
        return FALSE;  
  
    DWORD hMod = (DWORD)mbi.AllocationBase;  
  
    if ( !GetModuleFileName( (HMODULE)hMod, szModule, len ) )  
        return FALSE;  
  
   // Point to the DOS header in memory  
    PIMAGE_DOS_HEADER pDosHdr = (PIMAGE_DOS_HEADER)hMod;  
  
   // From the DOS header, find the NT (PE) header  
    PIMAGE_NT_HEADERS pNtHdr = (PIMAGE_NT_HEADERS)(hMod + pDosHdr->e_lfanew);  
  
    PIMAGE_SECTION_HEADER pSection = IMAGE_FIRST_SECTION( pNtHdr );  
  
    DWORD rva = (DWORD)addr - hMod; // RVA is offset from module load address  
  
    // Iterate through the section table, looking for the one that encompasses  
    // the linear address.  
    for (   unsigned i = 0;  
            i< pNtHdr->FileHeader.NumberOfSections;  
            i++, pSection++ )  
    {  
        DWORD sectionStart = pSection->VirtualAddress;  
        DWORD sectionEnd = sectionStart  
                    + max(pSection->SizeOfRawData, pSection->Misc.VirtualSize);  

       // Is the address in this section???  
        if ( (rva >= sectionStart)&& (rva <= sectionEnd) )  
        {  
            // Yes, address is in the section.  Calculate section and offset,  
            // and store in the "section"& "offset" params, which were  
            // passed by reference.  
            section = i+1;  
            offset = rva - sectionStart;  
            return TRUE;  
        }  
    }  
  
    return FALSE;   // Should never get here!  
}  
  
//============================================================  
// Walks the stack, and writes the results to the report file  
//============================================================  
void MSJExceptionHandler::IntelStackWalk( PCONTEXT pContext )  
{  
    _tprintf( _T("\nCall stack:\n") );  
  
    _tprintf( _T("Address   Frame     Logical addr  Module\n") );  
  
    DWORD pc = pContext->Eip;  
    PDWORD pFrame, pPrevFrame;  
     
    pFrame = (PDWORD)pContext->Ebp;  
  
    do  
    {  
        TCHAR szModule[MAX_PATH] = _T("");  
        DWORD section = 0, offset = 0;  
  
        GetLogicalAddress((PVOID)pc, szModule,sizeof(szModule),section,offset );  
  
        _tprintf( _T("%08X  %08X  %04X:%08X %s\n"),  
                    pc, pFrame, section, offset, szModule );  
  
        pc = pFrame[1];  
  
        pPrevFrame = pFrame;  
  
        pFrame = (PDWORD)pFrame[0]; // precede to next higher frame on stack  
  
        if ( (DWORD)pFrame& 3 )    // Frame pointer must be aligned on a  
            break;                 // DWORD boundary.  Bail if not so.  
  
        if ( pFrame <= pPrevFrame )  
            break;  
  
       // Can two DWORDs be read from the supposed frame address?           
        if ( IsBadWritePtr(pFrame, sizeof(PVOID)*2) )  
            break;  
  
    } while ( 1 );  
}  
  
//============================================================================  
// Helper function that writes to the report file, and allows the user to use  
// printf style formating                                                      
//============================================================================  
int __cdecl MSJExceptionHandler::_tprintf(const TCHAR * format, ...)  
{  
    TCHAR szBuff[1024];  
    int retValue;  
    DWORD cbWritten;  
    va_list argptr;  
           
    va_start( argptr, format );  
    retValue = wvsprintf( szBuff, format, argptr );  
    va_end( argptr );  
  
    WriteFile( m_hReportFile, szBuff, retValue * sizeof(TCHAR),& cbWritten, 0 );  
  
    return retValue;  
}