[hbelusca] 57809: [NTDLL/CSRSRV] Re-fix part of the capture-buffer offset setting, based on what I understood from all my previous investigations. It reverts a little part of r57673 but fixing some...

Author: hbelusca
Date: Thu Dec  6 22:24:27 2012
New Revision: 57809

URL: http://svn.reactos.org/svn/reactos?rev=57809&view=rev
Log:
[NTDLL/CSRSRV]
Re-fix part of the capture-buffer offset setting, based on what I understood from all my previous investigations. It reverts a little part of r57673 but fixing some existing bugs there.

Modified:
    branches/ros-csrss/dll/ntdll/csr/connect.c
    branches/ros-csrss/subsystems/win32/csrsrv/api.c

Modified: branches/ros-csrss/dll/ntdll/csr/connect.c
URL: http://svn.reactos.org/svn/reactos/branches/ros-csrss/dll/ntdll/csr/connect....
==============================================================================
--- branches/ros-csrss/dll/ntdll/csr/connect.c [iso-8859-1] (original)
+++ branches/ros-csrss/dll/ntdll/csr/connect.c [iso-8859-1] Thu Dec  6 22:24:27 2012
@@ -51,7 +51,8 @@
                     IN ULONG DataLength)
 {
     NTSTATUS Status;
-    ULONG i;
+    ULONG PointerCount;
+    PULONG_PTR OffsetPointer;

/* Fill out the Port Message Header. */
     ApiMessage->Header.u2.ZeroInit = 0;
@@ -90,13 +91,16 @@
              * a server pointer, and each pointer to these message pointers
              * is converted into an offset.
              */
-            for (i = 0 ; i < CaptureBuffer->PointerCount ; ++i)
+            PointerCount  = CaptureBuffer->PointerCount;
+            OffsetPointer = CaptureBuffer->PointerOffsetsArray;
+            while (PointerCount--)
             {
-                if (CaptureBuffer->PointerOffsetsArray[i] != 0)
+                if (*OffsetPointer != 0)
                 {
-                    *(PULONG_PTR)CaptureBuffer->PointerOffsetsArray[i] += CsrPortMemoryDelta;
-                    CaptureBuffer->PointerOffsetsArray[i] -= (ULONG_PTR)ApiMessage;
+                    *(PULONG_PTR)*OffsetPointer += CsrPortMemoryDelta;
+                    *OffsetPointer -= (ULONG_PTR)ApiMessage;
                 }
+                ++OffsetPointer;
             }
         }

@@ -120,13 +124,16 @@
              * pointers, and convert back these message server pointers
              * into client pointers.
              */
-            for (i = 0 ; i < CaptureBuffer->PointerCount ; ++i)
+            PointerCount  = CaptureBuffer->PointerCount;
+            OffsetPointer = CaptureBuffer->PointerOffsetsArray;
+            while (PointerCount--)
             {
-                if (CaptureBuffer->PointerOffsetsArray[i] != 0)
+                if (*OffsetPointer != 0)
                 {
-                    CaptureBuffer->PointerOffsetsArray[i] += (ULONG_PTR)ApiMessage;
-                    *(PULONG_PTR)CaptureBuffer->PointerOffsetsArray[i] -= CsrPortMemoryDelta;
+                    *OffsetPointer += (ULONG_PTR)ApiMessage;
+                    *(PULONG_PTR)*OffsetPointer -= CsrPortMemoryDelta;
                 }
+                ++OffsetPointer;
             }
         }

Modified: branches/ros-csrss/subsystems/win32/csrsrv/api.c
URL: http://svn.reactos.org/svn/reactos/branches/ros-csrss/subsystems/win32/csrsr...
==============================================================================
--- branches/ros-csrss/subsystems/win32/csrsrv/api.c [iso-8859-1] (original)
+++ branches/ros-csrss/subsystems/win32/csrsrv/api.c [iso-8859-1] Thu Dec  6 22:24:27 2012
@@ -1125,7 +1125,9 @@
     PCSR_CAPTURE_BUFFER LocalCaptureBuffer = NULL, RemoteCaptureBuffer = NULL;
     SIZE_T BufferDistance;
     ULONG Length = 0;
-    ULONG i;
+    ULONG PointerCount;
+    PULONG_PTR OffsetPointer;
+    ULONG_PTR CurrentOffset;

/* Use SEH to make sure this is valid */
     _SEH2_TRY
@@ -1182,19 +1184,23 @@
      * All the pointer offsets correspond to pointers which point
      * to the remote data buffer instead of the local one.
      */
-    for (i = 0 ; i < RemoteCaptureBuffer->PointerCount ; ++i)
-    {
-        if (RemoteCaptureBuffer->PointerOffsetsArray[i] != 0)
-        {
-            /* Temporarily transform the offset into a pointer */
-            RemoteCaptureBuffer->PointerOffsetsArray[i] += (ULONG_PTR)ApiMessage;
+    PointerCount  = RemoteCaptureBuffer->PointerCount;
+    OffsetPointer = RemoteCaptureBuffer->PointerOffsetsArray;
+    while (PointerCount--)
+    {
+        CurrentOffset = *OffsetPointer;
+
+        if (CurrentOffset != 0)
+        {
+            /* Get the pointer corresponding to the offset */
+            CurrentOffset += (ULONG_PTR)ApiMessage;

/* Validate the bounds of the current pointed pointer */
-            if ((*(PULONG_PTR)RemoteCaptureBuffer->PointerOffsetsArray[i] >= CsrThread->Process->ClientViewBase) &&
-                (*(PULONG_PTR)RemoteCaptureBuffer->PointerOffsetsArray[i] < CsrThread->Process->ClientViewBounds))
+            if ((*(PULONG_PTR)CurrentOffset >= CsrThread->Process->ClientViewBase) &&
+                (*(PULONG_PTR)CurrentOffset < CsrThread->Process->ClientViewBounds))
             {
                 /* Modify the pointed pointer to take into account its new position */
-                *(PULONG_PTR)RemoteCaptureBuffer->PointerOffsetsArray[i] += BufferDistance;
+                *(PULONG_PTR)CurrentOffset += BufferDistance;
             }
             else
             {
@@ -1203,10 +1209,9 @@
                 DbgBreakPoint();
                 ApiMessage->Status = STATUS_INVALID_PARAMETER;
             }
-
-            /* Transform back into an offset */
-            RemoteCaptureBuffer->PointerOffsetsArray[i] -= (ULONG_PTR)ApiMessage;
-        }
+        }
+
+        ++OffsetPointer;
     }

/* Check if we got success */
@@ -1249,7 +1254,9 @@
 {
     PCSR_CAPTURE_BUFFER RemoteCaptureBuffer, LocalCaptureBuffer;
     SIZE_T BufferDistance;
-    ULONG i;
+    ULONG PointerCount;
+    PULONG_PTR OffsetPointer;
+    ULONG_PTR CurrentOffset;

/* Get the remote capture buffer */
     RemoteCaptureBuffer = ApiMessage->CsrCaptureData;
@@ -1272,19 +1279,22 @@
      * to the local data buffer instead of the remote one (revert
      * the logic of CsrCaptureArguments).
      */
-    for (i = 0 ; i < RemoteCaptureBuffer->PointerCount ; ++i)
-    {
-        if (RemoteCaptureBuffer->PointerOffsetsArray[i] != 0)
-        {
-            /* Temporarily transform the offset into a pointer */
-            RemoteCaptureBuffer->PointerOffsetsArray[i] += (ULONG_PTR)ApiMessage;
+    PointerCount  = RemoteCaptureBuffer->PointerCount;
+    OffsetPointer = RemoteCaptureBuffer->PointerOffsetsArray;
+    while (PointerCount--)
+    {
+        CurrentOffset = *OffsetPointer;
+
+        if (CurrentOffset != 0)
+        {
+            /* Get the pointer corresponding to the offset */
+            CurrentOffset += (ULONG_PTR)ApiMessage;

/* Modify the pointed pointer to take into account its new position */
-            *(PULONG_PTR)RemoteCaptureBuffer->PointerOffsetsArray[i] -= BufferDistance;
-
-            /* Transform back into an offset */
-            RemoteCaptureBuffer->PointerOffsetsArray[i] -= (ULONG_PTR)ApiMessage;
-        }
+            *(PULONG_PTR)CurrentOffset -= BufferDistance;
+        }
+
+        ++OffsetPointer;
     }

/* Copy the data back */
@@ -1328,7 +1338,8 @@
 {
     PCSR_CAPTURE_BUFFER CaptureBuffer = ApiMessage->CsrCaptureData;
     SIZE_T BufferDistance = (ULONG_PTR)Buffer - (ULONG_PTR)ApiMessage;
-    ULONG i;
+    ULONG PointerCount;
+    PULONG_PTR OffsetPointer;

/*
      * Check whether we have a valid buffer pointer, elements
@@ -1364,16 +1375,20 @@
         if ((CaptureBuffer->Size - (ULONG_PTR)*Buffer + (ULONG_PTR)CaptureBuffer) >=
             (ElementCount * ElementSize))
         {
-            for (i = 0 ; i < CaptureBuffer->PointerCount ; ++i)
+            /* Perform the validation test */
+            PointerCount  = CaptureBuffer->PointerCount;
+            OffsetPointer = CaptureBuffer->PointerOffsetsArray;
+            while (PointerCount--)
             {
                 /*
                  * The pointer offset must be equal to the delta between
                  * the addresses of the buffer and of the API message.
                  */
-                if (CaptureBuffer->PointerOffsetsArray[i] == BufferDistance)
+                if (*OffsetPointer == BufferDistance)
                 {
                     return TRUE;
                 }
+                ++OffsetPointer;
             }
         }
     }