reactos/ntoskrnl/ps/win32.c

/*
 * PROJECT:         ReactOS Kernel
 * LICENSE:         GPL - See COPYING in the top level directory
 * FILE:            ntoskrnl/ps/win32.c
 * PURPOSE:         Process Manager: Win32K Initialization and Support
 * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
 */

/* INCLUDES ****************************************************************/

#include <ntoskrnl.h>
#include <winerror.h>
#define NDEBUG
#include <debug.h>

/* GLOBALS ******************************************************************/

PKWIN32_PROCESS_CALLOUT PspW32ProcessCallout = NULL;
PKWIN32_THREAD_CALLOUT PspW32ThreadCallout = NULL;
PGDI_BATCHFLUSH_ROUTINE KeGdiFlushUserBatch = NULL;
extern PKWIN32_PARSEMETHOD_CALLOUT ExpWindowStationObjectParse;
extern PKWIN32_DELETEMETHOD_CALLOUT ExpWindowStationObjectDelete;
extern PKWIN32_DELETEMETHOD_CALLOUT ExpDesktopObjectDelete;
extern PKWIN32_POWEREVENT_CALLOUT PopEventCallout;

/* PRIVATE FUNCTIONS *********************************************************/

NTSTATUS
NTAPI
PsConvertToGuiThread(VOID)
{
    ULONG_PTR NewStack;
    PVOID OldStack;
    PETHREAD Thread = PsGetCurrentThread();
    PEPROCESS Process = PsGetCurrentProcess();
    NTSTATUS Status;
    PAGED_CODE();

    /* Validate the previous mode */
    if (KeGetPreviousMode() == KernelMode) return STATUS_INVALID_PARAMETER;

    /* If no win32k, crashes later */
    ASSERT(PspW32ProcessCallout != NULL);

    /* Make sure win32k is here */
    if (!PspW32ProcessCallout) return STATUS_ACCESS_DENIED;

    /* Make sure it's not already win32 */
    if (Thread->Tcb.ServiceTable != KeServiceDescriptorTable)
    {
        /* We're already a win32 thread */
        return STATUS_ALREADY_WIN32;
    }

    /* Check if we don't already have a kernel-mode stack */
    if (!Thread->Tcb.LargeStack)
    {
        /* We don't create one */
        NewStack = (ULONG_PTR)MmCreateKernelStack(TRUE, 0);
        if (!NewStack)
        {
            /* Panic in user-mode */
            NtCurrentTeb()->LastErrorValue = ERROR_NOT_ENOUGH_MEMORY;
            return STATUS_NO_MEMORY;
        }

        /* We're about to switch stacks. Enter a guarded region */
        KeEnterGuardedRegion();

        /* Switch stacks */
        OldStack = KeSwitchKernelStack((PVOID)NewStack,
                                       (PVOID)(NewStack - KERNEL_STACK_SIZE));

        /* Leave the guarded region */
        KeLeaveGuardedRegion();

        /* Delete the old stack */
        MmDeleteKernelStack(OldStack, FALSE);
    }

    /* This check is bizare. Check out win32k later */
    if (!Process->Win32Process)
    {
        /* Now tell win32k about us */
        Status = PspW32ProcessCallout(Process, TRUE);
        if (!NT_SUCCESS(Status)) return Status;
    }

    /* Set the new service table */
    Thread->Tcb.ServiceTable = KeServiceDescriptorTableShadow;
    ASSERT(Thread->Tcb.Win32Thread == 0);

    /* Tell Win32k about our thread */
    Status = PspW32ThreadCallout(Thread, PsW32ThreadCalloutInitialize);
    if (!NT_SUCCESS(Status))
    {
        /* Revert our table */
        Thread->Tcb.ServiceTable = KeServiceDescriptorTable;
    }

    /* Return status */
    return Status;
}

/* PUBLIC FUNCTIONS **********************************************************/

/*
 * @implemented
 */
VOID
NTAPI
PsEstablishWin32Callouts(IN PWIN32_CALLOUTS_FPNS CalloutData)
{
    /* Setup the callback pointers */
    PspW32ProcessCallout = CalloutData->ProcessCallout;
    PspW32ThreadCallout = CalloutData->ThreadCallout;
    ExpWindowStationObjectParse = CalloutData->WindowStationParseProcedure;
    ExpWindowStationObjectDelete = CalloutData->WindowStationDeleteProcedure;
    ExpDesktopObjectDelete = CalloutData->DesktopDeleteProcedure;
    PopEventCallout = CalloutData->PowerEventCallout;
    KeGdiFlushUserBatch = CalloutData->BatchFlushRoutine;
}

NTSTATUS
NTAPI
NtW32Call(IN ULONG RoutineIndex,
          IN PVOID Argument,
          IN ULONG ArgumentLength,
          OUT PVOID* Result,
          OUT PULONG ResultLength)
{
    PVOID RetResult;
    ULONG RetResultLength;
    NTSTATUS Status;
    ASSERT(KeGetPreviousMode() != KernelMode);

    /* Enter SEH for probing */
    _SEH2_TRY
    {
        /* Probe arguments */
        ProbeForWritePointer(Result);
        ProbeForWriteUlong(ResultLength);
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        /* Return the exception code */
        _SEH2_YIELD(return _SEH2_GetExceptionCode());
    }
    _SEH2_END;

    /* Call kernel function */
    Status = KeUserModeCallback(RoutineIndex,
                                Argument,
                                ArgumentLength,
                                &RetResult,
                                &RetResultLength);
    if (NT_SUCCESS(Status))
    {
        /* Enter SEH for write back */
        _SEH2_TRY
        {
            /* Return results to user mode */
            *Result = RetResult;
            *ResultLength = RetResultLength;
        }
        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
        {
            /* Get the exception code */
            Status = _SEH2_GetExceptionCode();
        }
        _SEH2_END;
    }

    /* Return the result */
    return Status;
}

/* EOF */