[ros-diffs] [tkreuzer] 44147: The freelist code is an increadible hack. It #defines structure members to other structure members and misuses them. Try to improve the hack by declaring PHYSICAL_PAGE as a unioun of MMPFN and the stuff that is used in the freelist code. Exchange the positions of RmapListHead with MapCount as the former must be pointer sized. More work is required here.

[tkreuzer at svn.reactos.org]

Author: tkreuzer
Date: Sat Nov 14 05:08:54 2009
New Revision: 44147

URL: http://svn.reactos.org/svn/reactos?rev=44147&view=rev
Log:
The freelist code is an increadible hack. It #defines structure members to other structure members and misuses them. Try to improve the hack by declaring PHYSICAL_PAGE as a unioun of MMPFN and the stuff that is used in the freelist code. Exchange the positions of RmapListHead with MapCount as the former must be pointer sized. More work is required here.

Modified:
    branches/ros-amd64-bringup/reactos/ntoskrnl/mm/freelist.c

Modified: branches/ros-amd64-bringup/reactos/ntoskrnl/mm/freelist.c
URL: http://svn.reactos.org/svn/reactos/branches/ros-amd64-bringup/reactos/ntoskrnl/mm/freelist.c?rev=44147&r1=44146&r2=44147&view=diff
==============================================================================
--- branches/ros-amd64-bringup/reactos/ntoskrnl/mm/freelist.c [iso-8859-1] (original)
+++ branches/ros-amd64-bringup/reactos/ntoskrnl/mm/freelist.c [iso-8859-1] Sat Nov 14 05:08:54 2009
@@ -32,23 +32,45 @@
 //
 // ReactOS to NT Physical Page Descriptor Entry Legacy Mapping Definitions
 //
-//        REACTOS                 NT
-//
-#define Consumer             PageLocation
-#define Type                 CacheAttribute
-#define Zero                 PrototypePte
-#define LockCount            u3.e1.PageColor
-#define RmapListHead         AweReferenceCount
-#define SavedSwapEntry       u4.EntireFrame
-#define Flags                u3.e1
-#define ReferenceCount       u3.ReferenceCount
-#define RemoveEntryList(x)   RemoveEntryList((PLIST_ENTRY)x)
-#define InsertTailList(x, y) InsertTailList(x, (PLIST_ENTRY)y)
-#define ListEntry            u1
-#define PHYSICAL_PAGE        MMPFN
-#define PPHYSICAL_PAGE       PMMPFN
-
-PPHYSICAL_PAGE MmPfnDatabase;
+
+typedef union
+{
+    MMPFN Pfn;
+
+    struct
+    {
+        LIST_ENTRY ListEntry; // 0x000
+        ULONG_PTR RmapListHead;   // 0x008
+        USHORT ReferenceCount; // 0x00C
+        struct // 0x00$
+        {
+            USHORT _unused1:1;
+            USHORT StartOfAllocation:1;
+            USHORT EndOfAllocation:1;
+            USHORT Zero:1; 
+            USHORT LockCount:4;
+            USHORT Consumer:3;
+            USHORT _unused2:1;
+            USHORT Type:2;
+            USHORT _unused3:1;
+            USHORT _unused4:1;
+        } Flags;
+        LONG MapCount; // 0x10
+        ULONG_PTR SavedSwapEntry; // 0x018
+    };
+} PHYSICAL_PAGE, *PPHYSICAL_PAGE;
+
+C_ASSERT(sizeof(PHYSICAL_PAGE) == sizeof(MMPFN));
+
+#define MiGetPfnEntry(Pfn) ((PPHYSICAL_PAGE)MiGetPfnEntry(Pfn))
+#define MiGetPfnEntryIndex(x) MiGetPfnEntryIndex((struct _MMPFN*)x)
+#define LockCount            Flags.LockCount
+
+PMMPFN MmPfnDatabase;
+#define MmPfnDatabase ((PPHYSICAL_PAGE)MmPfnDatabase)
+
+#define MMPFN PHYSICAL_PAGE
+#define PMMPFN PPHYSICAL_PAGE
 
 ULONG MmAvailablePages;
 ULONG MmResidentAvailablePages;
@@ -99,7 +121,7 @@
       return 0;
    }
    PageDescriptor = CONTAINING_RECORD(NextListEntry, PHYSICAL_PAGE, ListEntry);
-   ASSERT_PFN(PageDescriptor);
+   ASSERT_PFN(&PageDescriptor->Pfn);
    KeReleaseQueuedSpinLock(LockQueuePfnLock, oldIrql);
    return PageDescriptor - MmPfnDatabase;
 }
@@ -731,12 +753,10 @@
          NextEntry != &KeLoaderBlock->MemoryDescriptorListHead;
          NextEntry = NextEntry->Flink)
     {
-#undef ListEntry
         /* Get the descriptor */
         Md = CONTAINING_RECORD(NextEntry,
                                MEMORY_ALLOCATION_DESCRIPTOR,
                                ListEntry);
-#define ListEntry            u1        
 
         /* Skip bad memory */
         if ((Md->MemoryType == LoaderFirmwarePermanent) ||
@@ -800,7 +820,7 @@
    KIRQL oldIrql;
     
    oldIrql = KeAcquireQueuedSpinLock(LockQueuePfnLock);
-   MiGetPfnEntry(Pfn)->RmapListHead = (LONG)ListHead;
+   MiGetPfnEntry(Pfn)->RmapListHead = (LONG_PTR)ListHead;
    KeReleaseQueuedSpinLock(LockQueuePfnLock, oldIrql);
 }
 
@@ -929,7 +949,7 @@
    {
       MmAvailablePages++;
       if (Page->Flags.Consumer == MC_USER) RemoveEntryList(&Page->ListEntry);
-      if (Page->RmapListHead != (LONG)NULL)
+      if (Page->RmapListHead != (LONG_PTR)NULL)
       {
          DPRINT1("Freeing page with rmap entries.\n");
          KeBugCheck(MEMORY_MANAGEMENT);