[ros-diffs] [jgardou] 63947: [NTOS/MM] - Bring back PTE frame refcounting when serving a prototype PTE page fault. - Fix a bug in MiDeletePte where the said PTE frame was not unshared. - Improve transitional P...

[jgardou]

Author: jgardou
Date: Mon Aug 25 12:33:49 2014
New Revision: 63947

URL: http://svn.reactos.org/svn/reactos?rev=63947&view=rev
Log:
[NTOS/MM]
 - Bring back PTE frame refcounting when serving a prototype PTE page fault.
 - Fix a bug in MiDeletePte where the said PTE frame was not unshared.
 - Improve transitional PTEs deletion (will be needed for future work).
Do not always trust the comments stating that "strange RosMm code broke 
everything"

Modified:
    trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c
    trunk/reactos/ntoskrnl/mm/ARM3/virtual.c

Modified: trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c
URL: 
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c?rev=63947&r1=63946&r2=63947&view=diff
==============================================================================
--- trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c   [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c   [iso-8859-1] Mon Aug 25 
12:33:49 2014
@@ -709,12 +709,9 @@
     Pfn1->u3.e1.PrototypePte = 1;
 
     /* Increment the share count for the page table */
-    // FIXME: This doesn't work because we seem to bump the sharecount to two, 
and MiDeletePte gets annoyed and ASSERTs.
-    // This could be beause MiDeletePte is now being called from strange code 
in Rosmm
     PageTablePte = MiAddressToPte(PointerPte);
     Pfn2 = MiGetPfnEntry(PageTablePte->u.Hard.PageFrameNumber);
-    //Pfn2->u2.ShareCount++;
-    DBG_UNREFERENCED_LOCAL_VARIABLE(Pfn2);
+    Pfn2->u2.ShareCount++;
 
     /* Check where we should be getting the protection information from */
     if (PointerPte->u.Soft.PageFileHigh == MI_PTE_LOOKUP_NEEDED)

Modified: trunk/reactos/ntoskrnl/mm/ARM3/virtual.c
URL: 
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/virtual.c?rev=63947&r1=63946&r2=63947&view=diff
==============================================================================
--- trunk/reactos/ntoskrnl/mm/ARM3/virtual.c    [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/ARM3/virtual.c    [iso-8859-1] Mon Aug 25 
12:33:49 2014
@@ -407,15 +407,17 @@
     /* See if the PTE is valid */
     if (TempPte.u.Hard.Valid == 0)
     {
-        /* Prototype PTEs not supported yet */
+        /* Prototype and paged out PTEs not supported yet */
         ASSERT(TempPte.u.Soft.Prototype == 0);
+        ASSERT(TempPte.u.Soft.PageFileHigh == 0);
+
         if (TempPte.u.Soft.Transition)
         {
             /* Get the PFN entry */
             PageFrameIndex = PFN_FROM_PTE(&TempPte);
             Pfn1 = MiGetPfnEntry(PageFrameIndex);
 
-            DPRINT1("Pte %p is transitional!\n", PointerPte);
+            DPRINT("Pte %p is transitional!\n", PointerPte);
 
             /* Destroy the PTE */
             MI_ERASE_PTE(PointerPte);
@@ -433,12 +435,14 @@
                 /* And it should be in standby or modified list */
                 ASSERT((Pfn1->u3.e1.PageLocation == ModifiedPageList) || 
(Pfn1->u3.e1.PageLocation == StandbyPageList));
 
-                /* Unlink it and put it back in free list */
+                /* Unlink it and temporarily mark it as active */
                 MiUnlinkPageFromList(Pfn1);
+                Pfn1->u3.e2.ReferenceCount++;
                 Pfn1->u3.e1.PageLocation = ActiveAndValid;
 
-                /* Bring it back into the free list */
-                MiInsertPageInFreeList(PageFrameIndex);
+                /* This will put it back in free list and clean properly up */
+                MI_SET_PFN_DELETED(Pfn1);
+                MiDecrementReferenceCount(Pfn1, PageFrameIndex);
             }
             return;
         }
@@ -470,6 +474,11 @@
 #if (_MI_PAGING_LEVELS == 2)
         }
 #endif
+        /* Drop the share count on the page table */
+        PointerPde = MiPteToPde(PointerPte);
+        
MiDecrementShareCount(MiGetPfnEntry(PointerPde->u.Hard.PageFrameNumber),
+            PointerPde->u.Hard.PageFrameNumber);
+
         /* Drop the share count */
         MiDecrementShareCount(Pfn1, PageFrameIndex);