windows-xp/Source/XPSP1/NT/base/mvdm/vdmexts/util.c

/*++

Copyright (c) 1990  Microsoft Corporation

Module Name:

    heap.c

Abstract:

    This function contains the default ntsd debugger extensions

Author:

    Bob Day      (bobday) 29-Feb-1992 Grabbed standard header

Revision History:

    Neil Sandlin (NeilSa) 15-Jan-1996 Merged with vdmexts
                                      Added command line parsing

--*/

#include <precomp.h>
#pragma hdrstop

VDMCONTEXT ThreadContext;

PVOID LdtAddress = NULL;

BOOL
WINAPI
ReadProcessMem(
    LPVOID lpBaseAddress,
    LPVOID lpBuffer,
    DWORD nSize
    )
{
    return ReadProcessMemory( hCurrentProcess, lpBaseAddress, lpBuffer, nSize, NULL );
}

BOOL
WINAPI
WriteProcessMem(
    LPVOID lpBaseAddress,
    LPVOID lpBuffer,
    DWORD nSize
    )
{
    return WriteProcessMemory( hCurrentProcess, lpBaseAddress, lpBuffer, nSize, NULL );
}

#ifndef i386

//
// The following two routines implement the very funky way that we
// have to get register values on the 486 emulator.
//

ULONG
GetRegValue(
    NT_CPU_REG reg,
    BOOL bInNano,
    ULONG UMask
    )

{
    if (bInNano) {

        return(ReadDwordSafe(reg.nano_reg));

    } else if (UMask & reg.universe_8bit_mask) {

        return (ReadDwordSafe(reg.saved_reg) & 0xFFFFFF00 |
                ReadDwordSafe(reg.reg) & 0xFF);

    } else if (UMask & reg.universe_16bit_mask) {

        return (ReadDwordSafe(reg.saved_reg) & 0xFFFF0000 |
                ReadDwordSafe(reg.reg) & 0xFFFF);

    } else {

        return (ReadDwordSafe(reg.reg));

    }
}

ULONG
GetEspValue(
    NT_CPU_INFO nt_cpu_info,
    BOOL bInNano
    )

{
    if (bInNano) {

        return (ReadDwordSafe(nt_cpu_info.nano_esp));

    } else {

        if (ReadDwordSafe(nt_cpu_info.stack_is_big)) {

            return (ReadDwordSafe(nt_cpu_info.host_sp) -
                    ReadDwordSafe(nt_cpu_info.ss_base));

        } else {

            return (ReadDwordSafe(nt_cpu_info.esp_sanctuary) & 0xFFFF0000 |
                    (ReadDwordSafe(nt_cpu_info.host_sp) -
                     ReadDwordSafe(nt_cpu_info.ss_base) & 0xFFFF));

        }

    }

}

#endif

int
GetContext(
    VDMCONTEXT* lpContext
)
/*
    GetContext

    This function fills in the specified context record with
    the content of the 16-bit registers. The return value is
    the mode (v86 or PROT) of the client.

    Note that on x86, if the machine is currently in the monitor,
    we have to pick up the values from the VdmTib and IntelMSW.

*/
{
#ifndef i386    //
    int         mode;
    ULONG       pTmp;
    NT_CPU_INFO nt_cpu_info;
    BOOL        b;
    BOOL        bInNano;
    ULONG       UMask;
#if 0
    DWORD MyEflags;
#endif

    pTmp = (ULONG)EXPRESSION("ntvdm!nt_cpu_info");

    if ( pTmp ) {

        b = READMEM((LPVOID) pTmp, &nt_cpu_info, sizeof(NT_CPU_INFO));

        if ( !b ) {
            PRINTF("Could not read IntelRegisters context out of process\n");
            return( -1 );
        }

        bInNano = ReadDwordSafe((ULONG) nt_cpu_info.in_nano_cpu);
        UMask   = ReadDwordSafe((ULONG) nt_cpu_info.universe);

        lpContext->Eax = GetRegValue(nt_cpu_info.eax, bInNano, UMask);
        lpContext->Ecx = GetRegValue(nt_cpu_info.ecx, bInNano, UMask);
        lpContext->Edx = GetRegValue(nt_cpu_info.edx, bInNano, UMask);
        lpContext->Ebx = GetRegValue(nt_cpu_info.ebx, bInNano, UMask);
        lpContext->Ebp = GetRegValue(nt_cpu_info.ebp, bInNano, UMask);
        lpContext->Esi = GetRegValue(nt_cpu_info.esi, bInNano, UMask);
        lpContext->Edi = GetRegValue(nt_cpu_info.edi, bInNano, UMask);

        lpContext->Esp    = GetEspValue(nt_cpu_info, bInNano);

        //
        // nt_cpu_info.flags isn't very much use, because several of the
        // flags values are not kept in memory, but computed each time.
        // The emulator doesn't supply us with the right value, so we
        // try to get it from the code in VdmDebugger
        //

        lpContext->EFlags = ReadDwordSafe(nt_cpu_info.flags);
#if 0
        lpContext->EFlags = 0xffffffff;         // indicate value unknown

        if (InVdmPrompt() &&
            (pTmp = (ULONG)EXPRESSION("ntvdmd!VdmDbgEFLAGS"))        &&
            (READMEM((LPVOID) pTmp, &MyEflags, sizeof(DWORD))))  {

                lpContext->EFlags = MyEflags;

        }
#endif

        lpContext->Eip    = ReadDwordSafe(nt_cpu_info.eip);

        lpContext->SegEs = ReadWordSafe(nt_cpu_info.es);
        lpContext->SegCs = ReadWordSafe(nt_cpu_info.cs);
        lpContext->SegSs = ReadWordSafe(nt_cpu_info.ss);
        lpContext->SegDs = ReadWordSafe(nt_cpu_info.ds);
        lpContext->SegFs = ReadWordSafe(nt_cpu_info.fs);
        lpContext->SegGs = ReadWordSafe(nt_cpu_info.gs);


    } else {

        PRINTF("Could not find the symbol 'ntvdm!nt_cpu_info'\n");
        return( -1 );
    }

    if ( !(ReadDwordSafe(nt_cpu_info.cr0) & 1) ) {
        mode = V86_MODE;
    } else {
        mode = PROT_MODE;
    }
    return( mode );

#else           //

    NTSTATUS    rc;
    BOOL        b;
    int         mode;
    ULONG       lpVdmTib;
    ULONG       IntelMSW;

    lpContext->ContextFlags = CONTEXT_FULL;
    rc = NtGetContextThread( hCurrentThread,
                             lpContext );
    if ( NT_ERROR(rc) ) {
        PRINTF( "bde.k: Could not get current threads context - status = %08lX\n", rc );
        return( -1 );
    }
    /*
    ** Get the 16-bit registers from the context
    */

    if ( lpContext->EFlags & V86_BITS ) {
        /*
        ** V86 Mode
        */
        mode = V86_MODE;
    } else {
        if ( ((WORD)(lpContext->SegCs & RPL_MASK)) != KGDT_R3_CODE ) {
            mode = PROT_MODE;
        } else {
            /*
            ** We are in flat 32-bit address space!
            */
            lpVdmTib = GetCurrentVdmTib();
            if ( !lpVdmTib ) {
                PRINTF("Could not find the symbol 'VdmTib'\n");
                return( -1 );
            }

            b = READMEM((LPVOID)(lpVdmTib+FIELD_OFFSET(VDM_TIB,VdmContext)),
                        lpContext, sizeof(VDMCONTEXT));

            if ( !b ) {
                PRINTF("Could not read IntelRegisters context out of process\n");
                return( -1 );
            }

            b = READMEM((LPVOID)(lpVdmTib+FIELD_OFFSET(VDM_TIB,IntelMSW)),
                        &IntelMSW, sizeof(IntelMSW));

            if ( !b ) {
                PRINTF("Could not read IntelMSW out of process\n");
                return( -1 );
            }

            if ( IntelMSW & MSW_PE ) {
                mode = PROT_MODE;
            } else {
                mode = V86_MODE;
            }
        }
    }

    return( mode );
#endif
}

ULONG
GetIntelBase(
    VOID
    )
{
#ifndef i386
    ULONG IntelBase;
    BOOL        b;

    IntelBase = (ULONG)EXPRESSION("ntvdm!Start_of_M_area");
    if ( IntelBase ) {

        b = READMEM((LPVOID) IntelBase, &IntelBase, sizeof(ULONG));

        if ( !b ) {
            PRINTF("Could not read symbol 'ntvdm!Start_of_M_area\n");
            return(0);
        }

    } else {
        PRINTF("Could not find the symbol 'ntvdm!Start_of_M_area'\n");
    }

    return(IntelBase);
#else
    return(0);
#endif
}

DWORD read_dword(
    ULONG   lpAddress,
    BOOL    bSafe
) {
    BOOL    b;
    DWORD   dword;

    b = READMEM((LPVOID)lpAddress, &dword, sizeof(dword));

    if ( !b ) {
        if ( !bSafe ) {
            PRINTF("Failure reading dword at memory location %08lX\n", lpAddress );
        }
        return( 0 );
    }
    return( dword );
}

WORD read_word(
    ULONG   lpAddress,
    BOOL    bSafe
) {
    BOOL    b;
    WORD    word;

    b = READMEM((LPVOID)lpAddress, &word, sizeof(word));

    if ( !b ) {
        if ( !bSafe ) {
            PRINTF("Failure reading word at memory location %08lX\n", lpAddress );
        }
        return( 0 );
    }
    return( word );
}

BYTE read_byte(
    ULONG   lpAddress,
    BOOL    bSafe
) {
    BOOL    b;
    BYTE    byte;

    b = READMEM((LPVOID)lpAddress, &byte, sizeof(byte));

    if ( !b ) {
        if ( !bSafe ) {
            PRINTF("Failure reading byte at memory location %08lX\n", lpAddress );
        }
        return( 0 );
    }
    return( byte );
}

BOOL read_gnode32(
    ULONG   lpAddress,
    PGNODE32  p,
    BOOL    bSafe
) {
    BOOL    b;

    b = READMEM((LPVOID)lpAddress, p, sizeof(*p));

    if ( !b ) {
        if ( !bSafe ) {
            PRINTF("Failure reading word at memory location %08lX\n", lpAddress );
        }
        return( 0 );
    }
    return( TRUE );
}


BOOL GetDescriptorData(
    WORD selector,
    LPVDMLDT_ENTRY pdte
    )
{

//
// Using GetThreadSelectorEntry would be nice if it just wasn't so slow.
// So, we use our LDT, just like on risc, which should be good enough.
//#ifdef i386
#if 0
    LDT_ENTRY  dte;
    if (!GetThreadSelectorEntry( hCurrentThread,
                                    selector,
                                   &dte)) {
        return( FALSE );
    }
    pdte->HighWord = dte.HighWord;
    pdte->BaseLow = dte.BaseLow;
    pdte->LimitLow = dte.LimitLow;
    return (TRUE);
#endif

    NTSTATUS                Status;
    selector &= ~(SELECTOR_LDT | SELECTOR_RPL);

    //
    // Get address of Ldt
    //

    if (!LdtAddress) {
        //
        // GetExpression is VERY SLOW under ntsd now. Who knows what the
        // debugger guys are up to. So just try to cache the address value
        // since it only changes twice (both during boot).
        //
        LdtAddress = (PVOID)EXPRESSION("ntvdm!Ldt");

        Status = READMEM(LdtAddress, &LdtAddress, sizeof(ULONG));
        if (!Status) {
            LdtAddress = NULL;
            return FALSE;
        }
    }

    Status = READMEM((PVOID)((ULONG)LdtAddress + selector),
                      pdte, sizeof(VDMLDT_ENTRY));

    // Now do a special hack for the period of time during dpmi
    // init where the LDT moves. This would all be unecessary if
    // we just were to get the ldt base from VDMDBG, which knows
    // everything.
    if (((ULONG)LdtAddress)-GetIntelBase() < 0x100000) {
        LdtAddress = NULL;  // forget the value again
    }

    return Status;
}

BOOL
ReadMemExpression(
    LPSTR expr,
    LPVOID buffer,
    ULONG len
    )
{
    PVOID pMem;

    pMem = (PVOID)(*GetExpression)(expr);
    if (!pMem) {
        PRINTF("Can't find symbol %s\n", expr);
        return FALSE;
    }

    if (!READMEM(pMem, buffer, len)) {
        PRINTF("Error reading memory\n");
        return FALSE;
    }

    return TRUE;
}


ULONG GetInfoFromSelector(
    WORD                    selector,
    int                     mode,
    SELECTORINFO            *si
) {

    ULONG                   base;
    ULONG                   type;
    VDMLDT_ENTRY            dte;

    switch( mode ) {
    case V86_MODE:
        base = (ULONG)selector << 4;
        if ( si ) {
            si->Limit = 0xFFFFL;
            si->Base = (ULONG)selector << 4;
            si->bCode = FALSE;
            si->bBig = FALSE;
            si->bExpandDown = FALSE;
            si->bWrite = TRUE;
            si->bPresent = TRUE;
        }
        break;
    case PROT_MODE:

        if ( !GetDescriptorData(selector, &dte) ) {
            return( (ULONG)-1 );
        }

        base =   ((ULONG)dte.HighWord.Bytes.BaseHi << 24)
               + ((ULONG)dte.HighWord.Bytes.BaseMid << 16)
               + ((ULONG)dte.BaseLow);

        if ( si ) {
            si->Limit =  (ULONG)dte.LimitLow
                      + ((ULONG)dte.HighWord.Bits.LimitHi << 16);

            if ( dte.HighWord.Bits.Granularity ) {
                si->Limit <<= 12;
                si->Limit += 0xFFF;
            }
            si->Base = base;

            type = dte.HighWord.Bits.Type;

            si->bSystem = !(BOOL) (type & 0x10);

            if (!si->bSystem) {
                si->bCode = (BOOL) (type & 8);
            }
            si->bAccessed = (BOOL) (type & 1);
            si->bWrite =    (BOOL) (type & 2);
            if (si->bCode) {
                si->bWrite = !si->bWrite;

            }

            si->bExpandDown = FALSE;
            if (!si->bSystem && !si->bCode) {
                si->bExpandDown = (BOOL) (type & 4);
            }

            si->bPresent =  (BOOL) dte.HighWord.Bits.Pres;
            si->bBig =  (BOOL) dte.HighWord.Bits.Default_Big;

        }

        break;

    case FLAT_MODE:
        PRINTF("Unsupported determination of base address in flat mode\n");
        base = 0;
        break;
    }

    return( base );
}


BOOL
InVdmPrompt(
    VOID
    )

{
    ULONG pTmp;
    BOOL InVdmDebugger;
    BOOL bReturn = FALSE;


    if ((pTmp = (ULONG)EXPRESSION("ntvdmd!InVdmDebugger"))           &&
        (READMEM((LPVOID) pTmp, &InVdmDebugger, sizeof(BOOL))))  {
        bReturn = InVdmDebugger;
    }

    return bReturn;
}

//****************************************************************************
//
// Command line parsing routines
//
//****************************************************************************
BOOL
SkipToNextWhiteSpace(
    VOID
    )
{
    char ch;
    while ( (ch = *lpArgumentString) != '\0' ) {
        if ( ch == ' ' || ch == '\t' || ch == '\r' || ch == '\n' ) {
            return TRUE;
        }
        lpArgumentString++;
    }
    return FALSE;
}


BOOL
GetNextToken(
    VOID
    )
{
    char ch;

    while ( (ch = *lpArgumentString) != '\0' ) {
        if ( ch != ' ' && ch != '\t' && ch != '\r' && ch != '\n' ) {
            return TRUE;
        }
        lpArgumentString++;
    }
    return FALSE;
}

ULONG
EvaluateToken(
    VOID
    )
{
    char ch;
    LPSTR pTemp;
    ULONG value = 0;

    if (GetNextToken()) {
        pTemp = lpArgumentString;
        SkipToNextWhiteSpace();
        ch = *lpArgumentString;
        *lpArgumentString = 0;
        value = (ULONG) EXPRESSION( pTemp );
        *lpArgumentString = ch;
    }
    return (value);
}

BOOL
IsTokenHex(
    VOID
    )
{

    UCHAR ch;
    LPSTR pTemp;
    BOOL result = TRUE;

    if (GetNextToken()) {
        pTemp = lpArgumentString;
        SkipToNextWhiteSpace();
        lpArgumentString--;

        while(lpArgumentString >= pTemp) {

            ch = *lpArgumentString--;

            if (ch < '0') {
                result = FALSE;
                break;
            }

            if ((ch > '9') && (ch < 'A')) {
                result = FALSE;
                break;
            }

            if ((ch > 'F') && (ch < 'a')) {
                result = FALSE;
                break;
            }

            if (ch > 'f') {
                result = FALSE;
                break;
            }

        }

        lpArgumentString = pTemp;

    }
    return (result);

}


BOOL
RegisterToAsciiValue(
    LPSTR *pszValue,
    LPSTR *pszReg
    )
{
    LPSTR szReg = *pszReg;
    LPSTR szValue = *pszValue;

    if (!_strnicmp(szReg, "ax", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Eax), szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "bx", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Ebx), szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "cx", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Ecx), szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "dx", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Edx), szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "si", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Esi), szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "di", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Edi), szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "sp", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Esp), szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "bp", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Ebp), szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "ip", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)LOWORD(ThreadContext.Eip), szValue, 16);
        *pszReg += 2;

    } else if (!_strnicmp(szReg, "eax", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Eax, szValue, 16);
        *pszReg += 3;
    } else if (!_strnicmp(szReg, "ebx", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Ebx, szValue, 16);
        *pszReg += 3;
    } else if (!_strnicmp(szReg, "ecx", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Ecx, szValue, 16);
        *pszReg += 3;
    } else if (!_strnicmp(szReg, "edx", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Edx, szValue, 16);
        *pszReg += 3;
    } else if (!_strnicmp(szReg, "esi", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Esi, szValue, 16);
        *pszReg += 3;
    } else if (!_strnicmp(szReg, "edi", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Edi, szValue, 16);
        *pszReg += 3;
    } else if (!_strnicmp(szReg, "esp", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Esp, szValue, 16);
        *pszReg += 3;
    } else if (!_strnicmp(szReg, "ebp", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Ebp, szValue, 16);
        *pszReg += 3;
    } else if (!_strnicmp(szReg, "eip", 3) && !isalpha(szReg[3])) {
        _ultoa(ThreadContext.Eip, szValue, 16);
        *pszReg += 3;

    } else if (!_strnicmp(szReg, "cs", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)ThreadContext.SegCs, szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "ds", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)ThreadContext.SegDs, szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "es", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)ThreadContext.SegEs, szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "fs", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)ThreadContext.SegFs, szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "gs", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)ThreadContext.SegGs, szValue, 16);
        *pszReg += 2;
    } else if (!_strnicmp(szReg, "ss", 2) && !isalpha(szReg[2])) {
        _ultoa((ULONG)ThreadContext.SegSs, szValue, 16);
        *pszReg += 2;
    } else {
        return FALSE;
    }

//    PRINTF("value = %s\n", szValue);
    while (*szValue) {
        szValue++;
    }
    *pszValue = szValue;
    return TRUE;
}

VOID
ParseForIntelRegisters(
    LPSTR szTarg,
    LPSTR szSrc
    )
{

    while (*szSrc) {
        if (!isalpha(*szSrc)) {
            if (!isdigit(*szSrc)) {
                *szTarg++ = *szSrc++;
                continue;
            }

            while (isalpha(*szSrc) || isdigit(*szSrc)) {
                *szTarg++ = *szSrc++;
            }
            continue;
        }

        if (!RegisterToAsciiValue(&szTarg, &szSrc)) {
            while (isalpha(*szSrc) || isdigit(*szSrc)) {
                *szTarg++ = *szSrc++;
            }
        }

    }
    *szTarg = 0;
}

BOOL
ParseIntelAddress(
    int *pMode,
    WORD *pSelector,
    PULONG pOffset
    )

{
    char sel_text[128], off_text[128];
    char expr_text[256];
    char *colon;
    char *mode_prefix;
    WORD segment;
    char filename[9];

    colon = strchr( lpArgumentString, ':' );
    if ( colon == NULL ) {
        LPSTR pSymbol = lpArgumentString;
        BOOL bResult;
        char chTemp;

        SkipToNextWhiteSpace();
        chTemp = *lpArgumentString;
        *lpArgumentString = 0;

        bResult = FindAddress( pSymbol,
                              filename,
                              &segment,
                              pSelector,
                              pOffset,
                              pMode,
                              FALSE);

        *lpArgumentString = chTemp;

        if (bResult) {
            if (*pMode == NOT_LOADED) {
                PRINTF("Could not determine base of '%s'\n", pSymbol);
                return FALSE;
            } else {
                return TRUE;
            }

        } else {

            PRINTF("Could not find symbol: %s\n", pSymbol);
            return FALSE;
        }
    }

    *pMode = GetContext( &ThreadContext );

    mode_prefix = strchr( lpArgumentString, '&' );
    if ( mode_prefix == NULL ) {

        mode_prefix = strchr( lpArgumentString, '#' );
        if ( mode_prefix != NULL ) {

            if ( mode_prefix != lpArgumentString ) {
                PRINTF("Address must have '&' symbol as the first character\n");
                return FALSE;
            }

            *pMode = PROT_MODE;
            lpArgumentString = mode_prefix+1;
        }

    } else {

        if ( mode_prefix != lpArgumentString ) {
            PRINTF("Address must have '#' symbol as the first character\n");
            return FALSE;
        }
        *pMode = V86_MODE;
        lpArgumentString = mode_prefix+1;

    }

    *colon = '\0';
    strcpy( sel_text, lpArgumentString );
    *colon = ':';
    strcpy( off_text, colon+1 );

    ParseForIntelRegisters(expr_text, sel_text);
    *pSelector = (WORD) EXPRESSION( expr_text );
    ParseForIntelRegisters(expr_text, off_text);
    *pOffset   = (ULONG) EXPRESSION( expr_text );

    SkipToNextWhiteSpace();

    return TRUE;
}