[gadamopoulos] 51082: [win32k] - Improve the definition and simplify NtUserCreateDesktop, NtUserOpenDesktop, NtUserCreateWindowStation, NtUserOpenWindowStation

Author: gadamopoulos
Date: Thu Mar 17 13:19:18 2011
New Revision: 51082

URL: http://svn.reactos.org/svn/reactos?rev=51082&view=rev
Log:
[win32k]
- Improve the definition and simplify NtUserCreateDesktop, NtUserOpenDesktop,
NtUserCreateWindowStation, NtUserOpenWindowStation

Modified:
    trunk/reactos/dll/win32/user32/misc/desktop.c
    trunk/reactos/dll/win32/user32/misc/winsta.c
    trunk/reactos/include/reactos/win32k/ntuser.h
    trunk/reactos/subsystems/win32/win32k/ntuser/desktop.c
    trunk/reactos/subsystems/win32/win32k/ntuser/winsta.c

Modified: trunk/reactos/dll/win32/user32/misc/desktop.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/user32/misc/desk…
==============================================================================
--- trunk/reactos/dll/win32/user32/misc/desktop.c [iso-8859-1] (original)
+++ trunk/reactos/dll/win32/user32/misc/desktop.c [iso-8859-1] Thu Mar 17 13:19:18 2011
@@ -564,13 +564,22 @@
   ACCESS_MASK dwDesiredAccess)
 {
   UNICODE_STRING DesktopName;
+  OBJECT_ATTRIBUTES ObjectAttributes;
 
   RtlInitUnicodeString(&DesktopName, lpszDesktop);
 
-  return NtUserOpenDesktop(
-    &DesktopName,
-    dwFlags,
-    dwDesiredAccess);
+  InitializeObjectAttributes(&ObjectAttributes,
+                             &DesktopName,
+                             OBJ_CASE_INSENSITIVE,
+                             GetProcessWindowStation(),
+                             0);
+
+  if( fInherit == TRUE )
+  {
+      ObjectAttributes.Attributes |= OBJ_INHERIT;
+  }
+
+  return NtUserOpenDesktop(&ObjectAttributes, dwFlags, dwDesiredAccess);
 }
 
 

Modified: trunk/reactos/dll/win32/user32/misc/winsta.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/dll/win32/user32/misc/wins…
==============================================================================
--- trunk/reactos/dll/win32/user32/misc/winsta.c [iso-8859-1] (original)
+++ trunk/reactos/dll/win32/user32/misc/winsta.c [iso-8859-1] Thu Mar 17 13:19:18 2011
@@ -12,6 +12,7 @@
 #include <user32.h>
 
 #include <wine/debug.h>
+WINE_DEFAULT_DEBUG_CHANNEL(winsta);
 
 
 /*
@@ -58,12 +59,50 @@
 		     LPSECURITY_ATTRIBUTES lpsa)
 {
   UNICODE_STRING WindowStationName;
+  UNICODE_STRING WindowStationsDir =
RTL_CONSTANT_STRING(L"\\Windows\\WindowStations");
+  OBJECT_ATTRIBUTES ObjectAttributes;
+  HANDLE hWindowStationsDir;
+  NTSTATUS Status;
+  HWINSTA hwinsta;
+
+  /* Open WindowStations directory */
+  InitializeObjectAttributes(&ObjectAttributes,
+                             &WindowStationsDir,
+                             OBJ_CASE_INSENSITIVE,
+                             0,
+                             0);
+
+  Status = NtOpenDirectoryObject(&hWindowStationsDir, 
+                                 DIRECTORY_CREATE_OBJECT, 
+                                 &ObjectAttributes);
+  if(!NT_SUCCESS(Status))
+  {
+      ERR("Failed to open WindowStations directory\n");
+      return NULL;
+  }
 
   RtlInitUnicodeString(&WindowStationName, lpwinsta);
 
-  return NtUserCreateWindowStation(&WindowStationName,
-				   dwDesiredAccess,
-				   lpsa, 0, 0, 0, 0);
+  /* Create the window station object */
+  InitializeObjectAttributes(&ObjectAttributes,
+                             &WindowStationName,
+                             OBJ_CASE_INSENSITIVE,
+                             hWindowStationsDir,
+                             0);
+
+  /* Check if the handle should be inheritable */
+  if (lpsa && lpsa->bInheritHandle)
+  { 
+      ObjectAttributes.Attributes |= OBJ_INHERIT;
+  }
+
+  hwinsta = NtUserCreateWindowStation(&ObjectAttributes,
+                                      dwDesiredAccess,
+                                      0, 0, 0, 0, 0);
+
+  NtClose(hWindowStationsDir);
+
+  return hwinsta;
 }
 
 /*
@@ -299,14 +338,51 @@
  */
 HWINSTA WINAPI
 OpenWindowStationW(LPCWSTR lpszWinSta,
-		   BOOL fInherit,
-		   ACCESS_MASK dwDesiredAccess)
+                   BOOL fInherit,
+                   ACCESS_MASK dwDesiredAccess)
 {
   UNICODE_STRING WindowStationName;
-
+  UNICODE_STRING WindowStationsDir =
RTL_CONSTANT_STRING(L"\\Windows\\WindowStations");
+  OBJECT_ATTRIBUTES ObjectAttributes;
+  HANDLE hWindowStationsDir;
+  NTSTATUS Status;
+  HWINSTA hwinsta;
+
+  /* Open WindowStations directory */
+  InitializeObjectAttributes(&ObjectAttributes,
+                             &WindowStationsDir,
+                             OBJ_CASE_INSENSITIVE,
+                             0,
+                             0);
+
+  Status = NtOpenDirectoryObject(&hWindowStationsDir, 
+                                 DIRECTORY_TRAVERSE, 
+                                 &ObjectAttributes);
+  if(!NT_SUCCESS(Status))
+  {
+      ERR("Failed to open WindowStations directory\n");
+      return NULL;
+  }
+
+  /* Open the window station object */
   RtlInitUnicodeString(&WindowStationName, lpszWinSta);
 
-  return NtUserOpenWindowStation(&WindowStationName, dwDesiredAccess);
+  InitializeObjectAttributes(&ObjectAttributes,
+                             &WindowStationName,
+                             OBJ_CASE_INSENSITIVE,
+                             hWindowStationsDir,
+                             0);
+
+  if( fInherit == TRUE )
+  {
+      ObjectAttributes.Attributes |= OBJ_INHERIT;
+  }
+
+  hwinsta = NtUserOpenWindowStation(&ObjectAttributes, dwDesiredAccess);
+
+  NtClose(hWindowStationsDir);
+
+  return hwinsta;
 }
 
 

Modified: trunk/reactos/include/reactos/win32k/ntuser.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/include/reactos/win32k/ntu…
==============================================================================
--- trunk/reactos/include/reactos/win32k/ntuser.h [iso-8859-1] (original)
+++ trunk/reactos/include/reactos/win32k/ntuser.h [iso-8859-1] Thu Mar 17 13:19:18 2011
@@ -1462,7 +1462,7 @@
 HWND
 NTAPI
 NtUserCreateWindowEx(
-  DWORD dwExStyle, // |= 0x80000000 == Ansi used to set WNDS_ANSICREATOR
+  DWORD dwExStyle,
   PLARGE_STRING plstrClassName,
   PLARGE_STRING plstrClsVersion,
   PLARGE_STRING plstrWindowName,
@@ -1481,9 +1481,9 @@
 HWINSTA
 NTAPI
 NtUserCreateWindowStation(
-  PUNICODE_STRING lpszWindowStationName,
+  POBJECT_ATTRIBUTES ObjectAttributes,
   ACCESS_MASK dwDesiredAccess,
-  LPSECURITY_ATTRIBUTES lpSecurity,
+  DWORD Unknown2,
   DWORD Unknown3,
   DWORD Unknown4,
   DWORD Unknown5,
@@ -2301,9 +2301,9 @@
 HDESK
 NTAPI
 NtUserOpenDesktop(
-  PUNICODE_STRING lpszDesktopName,
-  DWORD dwFlags,
-  ACCESS_MASK dwDesiredAccess);
+   POBJECT_ATTRIBUTES ObjectAttributes,
+   DWORD dwFlags,
+   ACCESS_MASK dwDesiredAccess);
 
 HDESK
 NTAPI
@@ -2315,7 +2315,7 @@
 HWINSTA
 NTAPI
 NtUserOpenWindowStation(
-  PUNICODE_STRING lpszWindowStationName,
+  POBJECT_ATTRIBUTES ObjectAttributes,
   ACCESS_MASK dwDesiredAccess);
 
 BOOL

Modified: trunk/reactos/subsystems/win32/win32k/ntuser/desktop.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/win32/win32k/nt…
==============================================================================
--- trunk/reactos/subsystems/win32/win32k/ntuser/desktop.c [iso-8859-1] (original)
+++ trunk/reactos/subsystems/win32/win32k/ntuser/desktop.c [iso-8859-1] Thu Mar 17
13:19:18 2011
@@ -859,15 +859,12 @@
 
 HDESK APIENTRY
 NtUserCreateDesktop(
-   POBJECT_ATTRIBUTES poa,
+   POBJECT_ATTRIBUTES ObjectAttributes,
    PUNICODE_STRING lpszDesktopDevice,
    LPDEVMODEW lpdmw,
    DWORD dwFlags,
    ACCESS_MASK dwDesiredAccess)
 {
-   OBJECT_ATTRIBUTES ObjectAttributes;
-   PTHREADINFO W32Thread;
-   PWINSTATION_OBJECT WinStaObject;
    PDESKTOP DesktopObject;
    UNICODE_STRING DesktopName;
    NTSTATUS Status = STATUS_SUCCESS;
@@ -875,12 +872,9 @@
    CSR_API_MESSAGE Request;
    PVOID DesktopHeapSystemBase = NULL;
    SIZE_T DesktopInfoSize;
-   UNICODE_STRING SafeDesktopName;
    ULONG DummyContext;
    ULONG_PTR HeapSize = 4 * 1024 * 1024; /* FIXME */
-   HWINSTA hWindowStation = NULL ;
-   PUNICODE_STRING lpszDesktopName = NULL;
-   UNICODE_STRING ClassName, MenuName;
+   UNICODE_STRING ClassName;
    LARGE_STRING WindowName;
    BOOL NoHooks = FALSE;
    PWND pWnd = NULL;
@@ -889,7 +883,7 @@
    PTHREADINFO ptiCurrent;
    DECLARE_RETURN(HDESK);
 
-   DPRINT("Enter NtUserCreateDesktop: %wZ\n", lpszDesktopName);
+   DPRINT("Enter NtUserCreateDesktop\n");
    UserEnterExclusive();
 
    ptiCurrent = PsGetCurrentThreadWin32Thread();
@@ -899,68 +893,7 @@
       NoHooks = (ptiCurrent->TIF_flags & TIF_DISABLEHOOKS);
       ptiCurrent->TIF_flags |= TIF_DISABLEHOOKS;
    }
-
-   _SEH2_TRY
-   {
-      ProbeForRead( poa,
-                    sizeof(OBJECT_ATTRIBUTES),
-                    1);
-
-      hWindowStation = poa->RootDirectory;
-      lpszDesktopName = poa->ObjectName;
-   }
-   _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
-   {
-      Status =_SEH2_GetExceptionCode();
-   }
-   _SEH2_END
-
-   if (! NT_SUCCESS(Status))
-   {
-      DPRINT1("Failed reading Object Attributes from user space.\n");
-      SetLastNtError(Status);
-      RETURN( NULL);
-   }
-
-   Status = IntValidateWindowStationHandle(
-               hWindowStation,
-               KernelMode,
-               0, /* FIXME - WINSTA_CREATEDESKTOP */
-               &WinStaObject);
-
-   if (! NT_SUCCESS(Status))
-   {
-      DPRINT1("Failed validation of window station handle (0x%X), cannot create
desktop %wZ\n",
-              hWindowStation, lpszDesktopName);
-      SetLastNtError(Status);
-      RETURN( NULL);
-   }
-   if(lpszDesktopName != NULL)
-   {
-      Status = IntSafeCopyUnicodeString(&SafeDesktopName, lpszDesktopName);
-      if(!NT_SUCCESS(Status))
-      {
-         SetLastNtError(Status);
-         RETURN( NULL);
-	  }
-   }
-   else
-   {
-      RtlInitUnicodeString(&SafeDesktopName, NULL);
-   }
-
-   if (! IntGetFullWindowStationName(&DesktopName, &WinStaObject->Name,
-                                     &SafeDesktopName))
-   {
-      SetLastNtError(STATUS_INSUFFICIENT_RESOURCES);
-      ObDereferenceObject(WinStaObject);
-      if (lpszDesktopName)
-         ExFreePoolWithTag(SafeDesktopName.Buffer, TAG_STRING);
-      RETURN( NULL);
-   }
-   if (lpszDesktopName)
-      ExFreePoolWithTag(SafeDesktopName.Buffer, TAG_STRING);
-   ObDereferenceObject(WinStaObject);
+   DesktopName.Buffer = NULL;
 
    /*
     * Try to open already existing desktop
@@ -968,18 +901,10 @@
 
    DPRINT("Trying to open desktop (%wZ)\n", &DesktopName);
 
-   /* Initialize ObjectAttributes for the desktop object */
-   InitializeObjectAttributes(
-      &ObjectAttributes,
-      &DesktopName,
-      0,
-      NULL,
-      NULL);
-
    Status = ObOpenObjectByName(
-               &ObjectAttributes,
+               ObjectAttributes,
                ExDesktopObjectType,
-               KernelMode,
+               UserMode,
                NULL,
                dwDesiredAccess,
                (PVOID)&DummyContext,
@@ -987,8 +912,27 @@
    if (!NT_SUCCESS(Status)) RETURN(NULL);
    if (Status == STATUS_OBJECT_NAME_EXISTS)
    {
-      ExFreePoolWithTag(DesktopName.Buffer, TAG_STRING);
       RETURN( Desktop);
+   }
+
+   /* Capture desktop name */
+   _SEH2_TRY
+   {
+      ProbeForRead( ObjectAttributes, sizeof(OBJECT_ATTRIBUTES),  1);
+
+      Status = IntSafeCopyUnicodeString(&DesktopName,
ObjectAttributes->ObjectName);
+   }
+   _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+   {
+      Status = _SEH2_GetExceptionCode();
+   }
+   _SEH2_END
+
+   if (! NT_SUCCESS(Status))
+   {
+      DPRINT1("Failed reading Object Attributes from user space.\n");
+      SetLastNtError(Status);
+      RETURN( NULL);
    }
 
    /* Reference the desktop */
@@ -1011,12 +955,11 @@
        RETURN(NULL);
    }
 
-   DesktopInfoSize = FIELD_OFFSET(DESKTOPINFO,
-                                  szDesktopName[(lpszDesktopName->Length /
sizeof(WCHAR)) + 1]);
+   DesktopInfoSize = sizeof(DESKTOPINFO) + DesktopName.Length;
 
    DesktopObject->pDeskInfo = RtlAllocateHeap(DesktopObject->pheapDesktop,
-                                                HEAP_NO_SERIALIZE,
-                                                DesktopInfoSize);
+                                              HEAP_NO_SERIALIZE,
+                                              DesktopInfoSize);
 
    if (DesktopObject->pDeskInfo == NULL)
    {
@@ -1031,8 +974,8 @@
    DesktopObject->pDeskInfo->pvDesktopBase = DesktopHeapSystemBase;
    DesktopObject->pDeskInfo->pvDesktopLimit =
(PVOID)((ULONG_PTR)DesktopHeapSystemBase + HeapSize);
    RtlCopyMemory(DesktopObject->pDeskInfo->szDesktopName,
-                 lpszDesktopName->Buffer,
-                 lpszDesktopName->Length);
+                 DesktopName.Buffer,
+                 DesktopName.Length);
 
    /* Initialize some local (to win32k) desktop state. */
    InitializeListHead(&DesktopObject->PtiList);
@@ -1042,7 +985,6 @@
    {
       InitializeListHead(&DesktopObject->pDeskInfo->aphkStart[i]);
    }
-   ExFreePoolWithTag(DesktopName.Buffer, TAG_STRING);
 
 //// why is this here?
 #if 0
@@ -1090,7 +1032,6 @@
    //
    ClassName.Buffer = ((PWSTR)((ULONG_PTR)(WORD)(gpsi->atomSysClass[ICLS_DESKTOP])));
    ClassName.Length = 0;
-   RtlZeroMemory(&MenuName, sizeof(MenuName));
    RtlZeroMemory(&WindowName, sizeof(WindowName));
 
    RtlZeroMemory(&Cs, sizeof(Cs));
@@ -1113,9 +1054,8 @@
       DesktopObject->pDeskInfo->spwnd = pWndDesktop;
    }
 #endif
-   W32Thread = PsGetCurrentThreadWin32Thread();
-
-   if (!W32Thread->rpdesk) IntSetThreadDesktop(DesktopObject,FALSE);
+
+   if (!ptiCurrent->rpdesk) IntSetThreadDesktop(DesktopObject,FALSE);
 
   /*
      Based on wine/server/window.c in get_desktop_window.
@@ -1123,7 +1063,6 @@
 
    ClassName.Buffer =
((PWSTR)((ULONG_PTR)(WORD)(gpsi->atomSysClass[ICLS_HWNDMESSAGE])));
    ClassName.Length = 0;
-   RtlZeroMemory(&MenuName, sizeof(MenuName));
    RtlZeroMemory(&WindowName, sizeof(WindowName));
 
    RtlZeroMemory(&Cs, sizeof(Cs));
@@ -1154,6 +1093,10 @@
    RETURN( Desktop);
 
 CLEANUP:
+   if(DesktopName.Buffer != NULL)
+   {
+       ExFreePoolWithTag(DesktopName.Buffer, TAG_STRING);
+   }
    if (!NoHooks && ptiCurrent) ptiCurrent->TIF_flags &=
~TIF_DISABLEHOOKS;
    DPRINT("Leave NtUserCreateDesktop, ret=%i\n",_ret_);
    UserLeave();
@@ -1184,85 +1127,17 @@
 
 HDESK APIENTRY
 NtUserOpenDesktop(
-   PUNICODE_STRING lpszDesktopName,
+   POBJECT_ATTRIBUTES ObjectAttributes,
    DWORD dwFlags,
    ACCESS_MASK dwDesiredAccess)
 {
-   OBJECT_ATTRIBUTES ObjectAttributes;
-   HWINSTA WinSta;
-   PWINSTATION_OBJECT WinStaObject;
-   UNICODE_STRING DesktopName;
-   UNICODE_STRING SafeDesktopName;
    NTSTATUS Status;
    HDESK Desktop;
-   BOOL Result;
-   DECLARE_RETURN(HDESK);
-
-   DPRINT("Enter NtUserOpenDesktop: %wZ\n", lpszDesktopName);
-   UserEnterExclusive();
-
-   /*
-    * Validate the window station handle and compose the fully
-    * qualified desktop name
-    */
-
-   WinSta = UserGetProcessWindowStation();
-   Status = IntValidateWindowStationHandle(
-               WinSta,
-               KernelMode,
-               0,
-               &WinStaObject);
-
-   if (!NT_SUCCESS(Status))
-   {
-      DPRINT1("Failed validation of window station handle (0x%X)\n", WinSta);
-      SetLastNtError(Status);
-      RETURN( 0);
-   }
-
-   if(lpszDesktopName != NULL)
-   {
-      Status = IntSafeCopyUnicodeString(&SafeDesktopName, lpszDesktopName);
-      if(!NT_SUCCESS(Status))
-      {
-         SetLastNtError(Status);
-         RETURN( NULL);
-	  }
-   }
-   else
-   {
-      RtlInitUnicodeString(&SafeDesktopName, NULL);
-   }
-
-   Result = IntGetFullWindowStationName(&DesktopName, &WinStaObject->Name,
-                                        &SafeDesktopName);
-
-   if (lpszDesktopName)
-      ExFreePoolWithTag(SafeDesktopName.Buffer, TAG_STRING);
-   ObDereferenceObject(WinStaObject);
-
-
-   if (!Result)
-   {
-      SetLastNtError(STATUS_INSUFFICIENT_RESOURCES);
-      RETURN( 0);
-   }
-
-
-   DPRINT("Trying to open desktop (%wZ)\n", &DesktopName);
-
-   /* Initialize ObjectAttributes for the desktop object */
-   InitializeObjectAttributes(
-      &ObjectAttributes,
-      &DesktopName,
-      0,
-      NULL,
-      NULL);
 
    Status = ObOpenObjectByName(
-               &ObjectAttributes,
+               ObjectAttributes,
                ExDesktopObjectType,
-               KernelMode,
+               UserMode,
                NULL,
                dwDesiredAccess,
                NULL,
@@ -1271,19 +1146,10 @@
    if (!NT_SUCCESS(Status))
    {
       SetLastNtError(Status);
-      ExFreePool(DesktopName.Buffer);
-      RETURN( 0);
-   }
-
-   DPRINT("Successfully opened desktop (%wZ)\n", &DesktopName);
-   ExFreePool(DesktopName.Buffer);
-
-   RETURN( Desktop);
-
-CLEANUP:
-   DPRINT("Leave NtUserOpenDesktop, ret=%i\n",_ret_);
-   UserLeave();
-   END_CLEANUP;
+      return 0;
+   }
+
+   return Desktop;
 }
 
 /*

Modified: trunk/reactos/subsystems/win32/win32k/ntuser/winsta.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/subsystems/win32/win32k/nt…
==============================================================================
--- trunk/reactos/subsystems/win32/win32k/ntuser/winsta.c [iso-8859-1] (original)
+++ trunk/reactos/subsystems/win32/win32k/ntuser/winsta.c [iso-8859-1] Thu Mar 17 13:19:18
2011
@@ -392,61 +392,23 @@
 
 HWINSTA APIENTRY
 NtUserCreateWindowStation(
-   PUNICODE_STRING lpszWindowStationName,
+   POBJECT_ATTRIBUTES ObjectAttributes,
    ACCESS_MASK dwDesiredAccess,
-   LPSECURITY_ATTRIBUTES lpSecurity,
+   DWORD Unknown2,
    DWORD Unknown3,
    DWORD Unknown4,
    DWORD Unknown5,
    DWORD Unknown6)
 {
    UNICODE_STRING WindowStationName;
-   UNICODE_STRING FullWindowStationName;
    PWINSTATION_OBJECT WindowStationObject;
    HWINSTA WindowStation;
-   OBJECT_ATTRIBUTES ObjectAttributes;
    NTSTATUS Status;
 
-   /*
-    * Generate full window station name
-    */
-   Status = ProbeAndCaptureUnicodeString(&WindowStationName,
-                                         UserMode,
-                                         lpszWindowStationName);
-   if (!NT_SUCCESS(Status))
-   {
-      DPRINT1("Failed to capture window station name (status 0x%08x)\n",
-              Status);
-      SetLastNtError(Status);
-      return 0;
-   }
-   if (!IntGetFullWindowStationName(&FullWindowStationName,
-                                    &WindowStationName,
-                                    NULL))
-   {
-      ReleaseCapturedUnicodeString(&WindowStationName, UserMode);
-      SetLastNtError(STATUS_INSUFFICIENT_RESOURCES);
-      return 0;
-   }
-
-   /*
-    * Try to open already existing window station
-    */
-
-   DPRINT("Trying to open window station (%wZ)\n",
&FullWindowStationName);
-
-   /* Initialize ObjectAttributes for the window station object */
-   InitializeObjectAttributes(
-      &ObjectAttributes,
-      &FullWindowStationName,
-      0,
-      NULL,
-      NULL);
-
    Status = ObOpenObjectByName(
-               &ObjectAttributes,
+               ObjectAttributes,
                ExWindowStationObjectType,
-               KernelMode,
+               UserMode,
                NULL,
                dwDesiredAccess,
                NULL,
@@ -454,24 +416,39 @@
 
    if (NT_SUCCESS(Status))
    {
-      DPRINT("Successfully opened window station (%wZ)\n",
-             FullWindowStationName);
-      ExFreePool(FullWindowStationName.Buffer);
-      ReleaseCapturedUnicodeString(&WindowStationName, UserMode);
       return (HWINSTA)WindowStation;
    }
+
 
    /*
     * No existing window station found, try to create new one
     */
-
-   DPRINT("Creating window station (%wZ)\n", &FullWindowStationName);
-
+   
+   /* Capture window station name */
+   _SEH2_TRY
+   {
+      ProbeForRead( ObjectAttributes, sizeof(OBJECT_ATTRIBUTES), 1);
+      Status = IntSafeCopyUnicodeString(&WindowStationName,
ObjectAttributes->ObjectName);
+   }
+   _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+   {
+      Status =_SEH2_GetExceptionCode();
+   }
+   _SEH2_END
+
+   if (! NT_SUCCESS(Status))
+   {
+      DPRINT1("Failed reading capturing window station name\n");
+      SetLastNtError(Status);
+      return NULL;
+   }
+
+   /* Create the window station object */
    Status = ObCreateObject(
-               KernelMode,
+               UserMode,
                ExWindowStationObjectType,
-               &ObjectAttributes,
-               ExGetPreviousMode(),
+               ObjectAttributes,
+               UserMode,
                NULL,
                sizeof(WINSTATION_OBJECT),
                0,
@@ -480,25 +457,10 @@
 
    if (!NT_SUCCESS(Status))
    {
-      DPRINT1("Failed creating window station (%wZ)\n",
&FullWindowStationName);
-      ExFreePool(FullWindowStationName.Buffer);
-      ReleaseCapturedUnicodeString(&WindowStationName, UserMode);
+      ExFreePoolWithTag(WindowStationName.Buffer, TAG_STRING);
       SetLastNtError(STATUS_INSUFFICIENT_RESOURCES);
       return 0;
    }
-
-   /* Zero out the buffer */
-   RtlZeroMemory(WindowStationObject, sizeof(WINSTATION_OBJECT));
-
-   KeInitializeSpinLock(&WindowStationObject->Lock);
-
-   InitializeListHead(&WindowStationObject->DesktopListHead);
-
-   WindowStationObject->AtomTable = NULL;
-   Status = RtlCreateAtomTable(37, &WindowStationObject->AtomTable);
-   WindowStationObject->SystemMenuTemplate = (HANDLE)0;
-
-   WindowStationObject->Name = WindowStationName;
 
    Status = ObInsertObject(
                (PVOID)WindowStationObject,
@@ -510,20 +472,21 @@
 
    if (!NT_SUCCESS(Status))
    {
-      DPRINT1("Failed creating window station (%wZ)\n",
&FullWindowStationName);
-      ExFreePool(FullWindowStationName.Buffer);
-      ExFreePool(WindowStationName.Buffer);
+      ExFreePoolWithTag(WindowStationName.Buffer, TAG_STRING);
       SetLastNtError(STATUS_INSUFFICIENT_RESOURCES);
       ObDereferenceObject(WindowStationObject);
       return 0;
    }
 
-   /*
-    * Initialize the new window station object
-    */
-
+   /* Initialize the window station */
+   RtlZeroMemory(WindowStationObject, sizeof(WINSTATION_OBJECT));
+
+   KeInitializeSpinLock(&WindowStationObject->Lock);
+   InitializeListHead(&WindowStationObject->DesktopListHead);
+   Status = RtlCreateAtomTable(37, &WindowStationObject->AtomTable);
+   WindowStationObject->SystemMenuTemplate = (HANDLE)0;
+   WindowStationObject->Name = WindowStationName;
    WindowStationObject->ScreenSaverRunning = FALSE;
-
    WindowStationObject->FlatMenu = FALSE;
 
    if (!IntSetupClipboard(WindowStationObject))
@@ -538,8 +501,6 @@
       InitCursorImpl();
    }
 
-   DPRINT("Window station successfully created (%wZ)\n",
&FullWindowStationName);
-   ExFreePool(FullWindowStationName.Buffer);
    return WindowStation;
 }
 
@@ -569,39 +530,16 @@
 
 HWINSTA APIENTRY
 NtUserOpenWindowStation(
-   PUNICODE_STRING lpszWindowStationName,
+   POBJECT_ATTRIBUTES ObjectAttributes,
    ACCESS_MASK dwDesiredAccess)
 {
-   UNICODE_STRING WindowStationName;
    HWINSTA WindowStation;
-   OBJECT_ATTRIBUTES ObjectAttributes;
    NTSTATUS Status;
 
-   /*
-    * Generate full window station name
-    */
-
-   if (!IntGetFullWindowStationName(&WindowStationName, lpszWindowStationName,
-                                    NULL))
-   {
-      SetLastNtError(STATUS_INSUFFICIENT_RESOURCES);
-      return 0;
-   }
-
-   DPRINT("Trying to open window station (%wZ)\n", &WindowStationName);
-
-   /* Initialize ObjectAttributes for the window station object */
-   InitializeObjectAttributes(
-      &ObjectAttributes,
-      &WindowStationName,
-      OBJ_CASE_INSENSITIVE,
-      NULL,
-      NULL);
-
    Status = ObOpenObjectByName(
-               &ObjectAttributes,
+               ObjectAttributes,
                ExWindowStationObjectType,
-               KernelMode,
+               UserMode,
                NULL,
                dwDesiredAccess,
                NULL,
@@ -610,12 +548,8 @@
    if (!NT_SUCCESS(Status))
    {
       SetLastNtError(Status);
-      ExFreePool(WindowStationName.Buffer);
       return 0;
    }
-
-   DPRINT("Successfully opened window station (%wZ)\n",
&WindowStationName);
-   ExFreePool(WindowStationName.Buffer);
 
    return WindowStation;
 }