- Fixed some problems which occurs if a read only segment is

changed to write and back to read only and if such a segment
  (or a page from such a segment) is paged out and reloaded again.

svn path=/trunk/; revision=7890

reactos/ntoskrnl/mm/section.c

@@ -16,7 +16,7 @@
  *  along with this program; if not, write to the Free Software
  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
-/* $Id: section.c,v 1.141 2004/01/05 14:28:21 weiden Exp $
+/* $Id: section.c,v 1.142 2004/01/27 20:13:08 hbirr Exp $
  *
  * PROJECT:         ReactOS kernel
  * FILE:            ntoskrnl/mm/section.c
@@ -379,11 +379,12 @@ MmUnsharePageEntrySectionSegment(PSECTION_OBJECT Section,
 	}
       else
 	{
-	  MmSetSavedSwapEntryPage(Page, 0);
 	  if ((Segment->Flags & MM_PAGEFILE_SEGMENT) ||
 	      (Segment->Characteristics & IMAGE_SECTION_CHAR_SHARED))
 	    {
-	      if (Dirty && !PageOut)
+	      if (!PageOut)
+	        {
+	          if (Dirty)
 	            {
 	              /*
 	               * FIXME:
@@ -398,16 +399,19 @@ MmUnsharePageEntrySectionSegment(PSECTION_OBJECT Section,
 		      if (!NT_SUCCESS(Status))
 		        {
 		          DPRINT1("MM: Failed to write to swap page (Status was 0x%.8X)\n", Status);
+			  KEBUGCHECK(0);
 		        }
                     }
 	          MmSetPageEntrySectionSegment(Segment, Offset, MAKE_SWAP_SSE(SavedSwapEntry));
+	      	  MmSetSavedSwapEntryPage(Page, 0);
+	        }
+              MmReleasePageMemoryConsumer(MC_USER, Page);
 	    }
 	  else
 	    {
-	      MmSetPageEntrySectionSegment(Segment, Offset, 0);
+	      DPRINT1("Found a swapentry for a non private page in an image or data file sgment\n");
-	      MmFreeSwapPage(SavedSwapEntry);
+	      KEBUGCHECK(0);
 	    }
-          MmReleasePageMemoryConsumer(MC_USER, Page);
 	}
     }
   else
@@ -623,6 +627,7 @@ MmNotPresentFaultSectionView(PMADDRESS_SPACE AddressSpace,
    ULONG Attributes;
    PMM_PAGEOP PageOp;
    PMM_REGION Region;
+   BOOL HasSwapEntry;
 
    /*
     * There is a window between taking the page fault and locking the
@@ -726,15 +731,20 @@ MmNotPresentFaultSectionView(PMADDRESS_SPACE AddressSpace,
        if (!MmIsPagePresent(AddressSpace->Process, Address))
 	 {
 	   Entry = MmGetPageEntrySectionSegment(Segment, Offset);
-	   if (Entry == 0)
+	   HasSwapEntry = MmIsPageSwapEntry(AddressSpace->Process, (PVOID)PAddress);
+
+	   if (PAGE_FROM_SSE(Entry) == 0 || HasSwapEntry)
 	     {
+	       /*
+	        * The page was a private page in another or in our address space 
+		*/ 
 	       MmUnlockSectionSegment(Segment);
                MmspCompleteAndReleasePageOp(PageOp);
 	       return(STATUS_MM_RESTART_OPERATION);
 	     }
 
 	   Page.QuadPart = (LONGLONG)(PAGE_FROM_SSE(Entry));
-	   MmReferencePage(Page);
+
 	   MmSharePageEntrySectionSegment(Segment, Offset);
 
 	   Status = MmCreateVirtualMapping(MemoryArea->Process,
@@ -771,11 +781,12 @@ MmNotPresentFaultSectionView(PMADDRESS_SPACE AddressSpace,
        return(STATUS_SUCCESS);
      }
 
+   HasSwapEntry = MmIsPageSwapEntry(AddressSpace->Process, (PVOID)PAddress);
+   if (HasSwapEntry)
+     {
        /*
         * Must be private page we have swapped out.
         */
-   if (MmIsPageSwapEntry(AddressSpace->Process, (PVOID)PAddress))
-     {
        SWAPENTRY SwapEntry;
        PMDL Mdl;
 
@@ -1506,51 +1517,6 @@ MmPageOutSectionView(PMADDRESS_SPACE AddressSpace,
       Context.Private = FALSE;
     }
 
-  /*
-   * Paging out data mapped read-only is easy.
-   */
-  if (Context.Segment->Protection & (PAGE_READONLY|PAGE_EXECUTE_READ))
-    {
-      /*
-       * Read-only data should never be in the swapfile.
-       */
-      if (SwapEntry != 0)
-	{
-	  DPRINT1("SwapEntry != 0 was 0x%.8X at address 0x%.8X, "
-		  "paddress 0x%.8X\n", SwapEntry, Address,
-		  PhysicalAddress);
-	  KEBUGCHECK(0);
-	}
-
-      /*
-       * Read-only data should never be COWed
-       */
-      if (Context.Private)
-	{
-	  DPRINT1("Had private copy of read-only page.\n");
-	  KEBUGCHECK(0);
-	}
-
-      /*
-       * Delete all mappings of this page.
-       */
-      MmDeleteAllRmaps(PhysicalAddress, (PVOID)&Context,
-		       MmPageOutDeleteMapping);
-      if (Context.WasDirty)
-	{
-	  DPRINT1("Had a dirty page of a read-only page.\n");
-	  KEBUGCHECK(0);
-	}
-
-      PageOp->Status = STATUS_SUCCESS;
-      MmspCompleteAndReleasePageOp(PageOp);
-      return(STATUS_SUCCESS);
-    }
-
-  /*
-   * Otherwise we have read-write data.
-   */
-
   /*
    * Take an additional reference to the page or the cache segment.
    */
@@ -1590,25 +1556,77 @@ MmPageOutSectionView(PMADDRESS_SPACE AddressSpace,
    * we can't free the page at this point.
    */
   SwapEntry = MmGetSavedSwapEntryPage(PhysicalAddress);
-  if (!Context.WasDirty && 
+  if (Context.Segment->Flags & MM_PAGEFILE_SEGMENT)
-      !(SwapEntry == 0 && 
-        (Context.Segment->Flags & MM_PAGEFILE_SEGMENT || 
-         Context.Segment->Characteristics & IMAGE_SECTION_CHAR_SHARED)))
     {
       if (Context.Private)
         {
-	  if (!(Context.Segment->Characteristics & IMAGE_SECTION_CHAR_BSS) &&
+          DPRINT1("Found a %s private page (address %x) in a pagefile segment.\n",
-	      SwapEntry == 0)
+	          Context.WasDirty ? "dirty" : "clean", Address);
+          KEBUGCHECK(0);
+	}
+      if (!Context.WasDirty && SwapEntry != 0)
         {
-	      DPRINT1("Private page, non-dirty but not swapped out "
+          MmSetSavedSwapEntryPage(PhysicalAddress, 0);
-		      "process %d address 0x%.8X\n",
+	  MmSetPageEntrySectionSegment(Context.Segment, Context.Offset, MAKE_SWAP_SSE(SwapEntry));
-		      AddressSpace->Process ? AddressSpace->Process->UniqueProcessId : 0,
+          MmReleasePageMemoryConsumer(MC_USER, PhysicalAddress);
+          PageOp->Status = STATUS_SUCCESS;
+          MmspCompleteAndReleasePageOp(PageOp);
+          return(STATUS_SUCCESS);
+	}
+    }
+  else if (Context.Segment->Characteristics & IMAGE_SECTION_CHAR_SHARED)
+    {
+      if (Context.Private)
+        {
+          DPRINT1("Found a %s private page (address %x) in a shared section segment.\n",
+	          Context.WasDirty ? "dirty" : "clean", Address);
+          KEBUGCHECK(0);
+	}
+      if (!Context.WasDirty || SwapEntry != 0)
+        {
+          MmSetSavedSwapEntryPage(PhysicalAddress, 0);
+	  if (SwapEntry != 0)
+	    {
+	      MmSetPageEntrySectionSegment(Context.Segment, Context.Offset, MAKE_SWAP_SSE(SwapEntry));
+	    }
+          MmReleasePageMemoryConsumer(MC_USER, PhysicalAddress);
+          PageOp->Status = STATUS_SUCCESS;
+          MmspCompleteAndReleasePageOp(PageOp);
+          return(STATUS_SUCCESS);
+	}
+    }
+  else if (!Context.Private && DirectMapped)
+    {
+      if (SwapEntry != 0)
+        {
+	  DPRINT1("Found a swapentry for a non private and direct mapped page (address %x)\n",
 	          Address);
 	  KEBUGCHECK(0);
 	}
-	  else
+      Status = CcRosUnmapCacheSegment(Bcb, FileOffset, FALSE);
+      if (!NT_SUCCESS(Status))
+        {
+          DPRINT1("CCRosUnmapCacheSegment failed, status = %x\n", Status);
+          KEBUGCHECK(0);
+	}
+      PageOp->Status = STATUS_SUCCESS;
+      MmspCompleteAndReleasePageOp(PageOp);
+      return(STATUS_SUCCESS);
+    }
+  else if (!Context.WasDirty && !DirectMapped && !Context.Private)
     {
       if (SwapEntry != 0)
+        {
+	  DPRINT1("Found a swap entry for a non dirty, non private and not direct mapped page (address %x)\n",
+	          Address);
+	  KEBUGCHECK(0);
+	}
+      MmReleasePageMemoryConsumer(MC_USER, PhysicalAddress);
+      PageOp->Status = STATUS_SUCCESS;
+      MmspCompleteAndReleasePageOp(PageOp);
+      return(STATUS_SUCCESS);
+    }
+  else if (!Context.WasDirty && Context.Private && SwapEntry != 0)
     {
       MmSetSavedSwapEntryPage(PhysicalAddress, 0);
       Status = MmCreatePageFileMapping(AddressSpace->Process,
@@ -1618,41 +1636,7 @@ MmPageOutSectionView(PMADDRESS_SPACE AddressSpace,
         {
 	  KEBUGCHECK(0);
 	}
-		}
-	    }
-	}
-      if (DirectMapped && !Context.Private)
-        {
-          Status = CcRosUnmapCacheSegment(Bcb, FileOffset, FALSE);
-          if (!NT_SUCCESS(Status))
-            {
-              DPRINT1("CCRosUnmapCacheSegment failed, status = %x\n", Status);
-              KEBUGCHECK(0);
-	    }
-	}
-      else
-        {
       MmReleasePageMemoryConsumer(MC_USER, PhysicalAddress);
-	}
-
-      PageOp->Status = STATUS_SUCCESS;
-      MmspCompleteAndReleasePageOp(PageOp);
-      return(STATUS_SUCCESS);
-    }
-
-  /*
-   * If this page was direct mapped from the cache then the cache manager
-   * will already have taken care of writing it back.
-   */
-  if (DirectMapped && !Context.Private)
-    {
-      assert(SwapEntry == 0);
-      Status = CcRosUnmapCacheSegment(Bcb, FileOffset, FALSE);
-      if (!NT_SUCCESS(Status))
-        {
-          DPRINT1("CcRosUnmapCacheSegment failed, status = %x\n", Status);
-          KEBUGCHECK(0);
-	}
       PageOp->Status = STATUS_SUCCESS;
       MmspCompleteAndReleasePageOp(PageOp);
       return(STATUS_SUCCESS);
@@ -1758,7 +1742,15 @@ MmPageOutSectionView(PMADDRESS_SPACE AddressSpace,
    */
   DPRINT("MM: Wrote section page 0x%.8X to swap!\n", PhysicalAddress);
   MmSetSavedSwapEntryPage(PhysicalAddress, 0);
+  if (Context.Segment->Flags & MM_PAGEFILE_SEGMENT || 
+      Context.Segment->Characteristics & IMAGE_SECTION_CHAR_SHARED)
+    {
+      MmSetPageEntrySectionSegment(Context.Segment, Context.Offset, MAKE_SWAP_SSE(SwapEntry));
+    }
+  else
+    {
       MmReleasePageMemoryConsumer(MC_USER, PhysicalAddress);
+    }
 
   if (Context.Private)
     {
@@ -2561,7 +2553,7 @@ MmCreateDataFileSection(PHANDLE SectionHandle,
       FileObject->SectionObjectPointer->DataSectionObject = (PVOID)Segment;
 
       Segment->FileOffset = 0;
-      Segment->Protection = 0;
+      Segment->Protection = SectionPageProtection;
       Segment->Attributes = 0;
       Segment->Flags = MM_DATAFILE_SEGMENT;
       Segment->Characteristics = 0;