Techwiki:Win32k/SHAREDINFO

 typedef struct _WNDMSG
 {
   DWORD maxMsgs;
   PBYTE abMsgs;
 } WNDMSG, *PWNDMSG;
 //
 //
 typedef struct _SHAREDINFO
 {                                 // W2k XP  7
   PSERVERINFO  psi;               // 000 000 000
   PHANDLEENTRY aheList;           // 004 004 004
#if WIN32K_VERSION == NTDDI_WIN7
   ULONG_PTR    HeEntrySize;       //         008
#endif
   PDISPLAYINFO pDisplayInfo;      // 008 008 00c
   ULONG_PTR    ulSharedDelta;     // 00c 00c 010
#if WIN32K_VERSION < NTDDI_WINXP
   WNDMSG       awmControl[27];    // 010 010 014
#else
   WNDMSG       awmControl[31];    // 010 010 014
#endif
   WNDMSG       DefWindowMsgs;     // 0e8 108 10c
   WNDMSG       DefWindowSpecMsgs; // 0f0 110 114
 } SHAREDINFO, *PSHAREDINFO;

Notes

• In Windows 7 this is exported from user32 as user32!gSharedInfo

References

• www.mista.nu/research/mandt-win32k-slides.pdf