Temporarily undo KeAttachProcess() done by win32k

reactos/ntoskrnl/lpc

diff -u -r1.14 -r1.15
--- send.c	7 Jan 2004 21:13:22 -0000	1.14
+++ send.c	31 May 2004 11:47:05 -0000	1.15
@@ -1,4 +1,4 @@

-/* $Id: send.c,v 1.14 2004/01/07 21:13:22 ea Exp $

+/* $Id: send.c,v 1.15 2004/05/31 11:47:05 gvg Exp $

  * 
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel

@@ -16,6 +16,7 @@

 #include <internal/port.h>
 #include <internal/dbg.h>
 #include <internal/safe.h>

+#include <internal/ps.h>

 
 #define NDEBUG
 #include <internal/debug.h>

@@ -222,6 +223,8 @@

 			PLPC_MESSAGE UnsafeLpcRequest,    
 			PLPC_MESSAGE UnsafeLpcReply)
 {

+   PETHREAD CurrentThread;
+   struct _EPROCESS *AttachedProcess;

    NTSTATUS Status;
    PEPORT Port;
    PQUEUEDMESSAGE Message;

@@ -243,22 +246,49 @@

 	return(Status);
      }
 

+   /* win32k sometimes needs to KeAttach() the CSRSS process in order to make
+      the PortHandle valid. Now that we've got the EPORT structure from the
+      handle we can undo this, so everything is normal again. Need to
+      re-KeAttach() before returning though */
+   CurrentThread = PsGetCurrentThread();
+   if (NULL == CurrentThread->OldProcess)
+     {
+       AttachedProcess = NULL;
+     }
+   else
+     {
+       AttachedProcess = CurrentThread->ThreadsProcess;
+       KeDetachProcess();
+     }
+

    Status = MmCopyFromCaller(&LpcRequestMessageSize,
 			     &UnsafeLpcRequest->MessageSize,
 			     sizeof(USHORT));
    if (!NT_SUCCESS(Status))
      {

+       if (NULL != AttachedProcess)
+         {
+           KeAttachProcess(AttachedProcess);
+         }

        ObDereferenceObject(Port);
        return(Status);
      }
    if (LpcRequestMessageSize > (sizeof(LPC_MESSAGE) + MAX_MESSAGE_DATA))
      {

+       if (NULL != AttachedProcess)
+         {
+           KeAttachProcess(AttachedProcess);
+         }

        ObDereferenceObject(Port);
        return(STATUS_PORT_MESSAGE_TOO_LONG);
      }
    LpcRequest = ExAllocatePool(NonPagedPool, LpcRequestMessageSize);
    if (LpcRequest == NULL)
      {

+       if (NULL != AttachedProcess)
+         {
+           KeAttachProcess(AttachedProcess);
+         }

        ObDereferenceObject(Port);
        return(STATUS_NO_MEMORY);
      }

@@ -267,6 +297,10 @@

    if (!NT_SUCCESS(Status))
      {
        ExFreePool(LpcRequest);

+       if (NULL != AttachedProcess)
+         {
+           KeAttachProcess(AttachedProcess);
+         }

        ObDereferenceObject(Port);
        return(Status);
      }

@@ -274,12 +308,20 @@

    if (LpcRequestMessageSize > (sizeof(LPC_MESSAGE) + MAX_MESSAGE_DATA))
      {
        ExFreePool(LpcRequest);

+       if (NULL != AttachedProcess)
+         {
+           KeAttachProcess(AttachedProcess);
+         }

        ObDereferenceObject(Port);
        return(STATUS_PORT_MESSAGE_TOO_LONG);
      }
    if (LpcRequest->DataSize != (LpcRequest->MessageSize - sizeof(LPC_MESSAGE)))
      {
        ExFreePool(LpcRequest);

+       if (NULL != AttachedProcess)
+         {
+           KeAttachProcess(AttachedProcess);
+         }

        ObDereferenceObject(Port);
        return(STATUS_PORT_MESSAGE_TOO_LONG);
      }

@@ -290,8 +332,12 @@

 				 Port);
    if (!NT_SUCCESS(Status))
      {

-	DbgPrint("Enqueue failed\n");

+	DPRINT1("Enqueue failed\n");

 	ExFreePool(LpcRequest);

+        if (NULL != AttachedProcess)
+          {
+            KeAttachProcess(AttachedProcess);
+          }

 	ObDereferenceObject(Port);
 	return(Status);
      }

@@ -334,6 +380,10 @@

 	   Status = STATUS_UNSUCCESSFUL;
 	 }
      }

+   if (NULL != AttachedProcess)
+     {
+       KeAttachProcess(AttachedProcess);
+     }

    ObDereferenceObject(Port);
    
    return(Status);