[fireball] 31299: Filip Navara <xnavara at volny dot cz> 's christmas gift - Fix certain cases of deallocation inside registry hives. - Add debug output in case of a problem in HvpRemoveFree.

Author: fireball
Date: Tue Dec 18 13:13:45 2007
New Revision: 31299

URL: http://svn.reactos.org/svn/reactos?rev=31299&view=rev
Log:
Filip Navara <xnavara at volny dot cz> 's christmas gift
- Fix certain cases of deallocation inside registry hives.
- Add debug output in case of a problem in HvpRemoveFree.

Modified:
    trunk/reactos/lib/cmlib/hivecell.c

Modified: trunk/reactos/lib/cmlib/hivecell.c
URL: http://svn.reactos.org/svn/reactos/trunk/reactos/lib/cmlib/hivecell.c?rev=31...
==============================================================================
--- trunk/reactos/lib/cmlib/hivecell.c (original)
+++ trunk/reactos/lib/cmlib/hivecell.c Tue Dec 18 13:13:45 2007
@@ -205,7 +205,7 @@
    PHCELL_INDEX FreeCellData;
    PHCELL_INDEX pFreeCellOffset;
    HSTORAGE_TYPE Storage;
-   ULONG Index;
+   ULONG Index, FreeListIndex;

ASSERT(RegistryHive->ReadOnly == FALSE);

@@ -223,6 +223,24 @@
       }
       pFreeCellOffset = FreeCellData;
    }
+
+   /* Something bad happened, print a useful trace info and bugcheck */
+   CMLTRACE(CMLIB_HCELL_DEBUG, "-- beginning of HvpRemoveFree trace --\n");
+   CMLTRACE(CMLIB_HCELL_DEBUG, "block we are about to free: %08x\n", CellIndex);
+   CMLTRACE(CMLIB_HCELL_DEBUG, "chosen free list index: %d\n", Index);
+   for (FreeListIndex = 0; FreeListIndex < 24; FreeListIndex++)
+   {
+      CMLTRACE(CMLIB_HCELL_DEBUG, "free list [%d]: ", FreeListIndex);
+      pFreeCellOffset = &RegistryHive->Storage[Storage].FreeDisplay[FreeListIndex];
+      while (*pFreeCellOffset != HCELL_NIL)
+      {
+         CMLTRACE(CMLIB_HCELL_DEBUG, "%08x ", *pFreeCellOffset);
+         FreeCellData = (PHCELL_INDEX)HvGetCell(RegistryHive, *pFreeCellOffset);
+         pFreeCellOffset = FreeCellData;
+      }
+      CMLTRACE(CMLIB_HCELL_DEBUG, "\n");
+   }
+   CMLTRACE(CMLIB_HCELL_DEBUG, "-- end of HvpRemoveFree trace --\n");

ASSERT(FALSE);
 }
@@ -466,11 +484,23 @@
       {
          if ((ULONG_PTR)Neighbor + Neighbor->Size == (ULONG_PTR)Free)
          {
-            Neighbor->Size += Free->Size;
+            HCELL_INDEX NeighborCellIndex =
+               (HCELL_INDEX)((ULONG_PTR)Neighbor - (ULONG_PTR)Bin +
+               Bin->FileOffset) | (CellIndex & HCELL_TYPE_MASK);
+
+            if (HvpComputeFreeListIndex(Neighbor->Size) !=
+                HvpComputeFreeListIndex(Neighbor->Size + Free->Size))
+            {
+               HvpRemoveFree(RegistryHive, Neighbor, NeighborCellIndex);
+               Neighbor->Size += Free->Size;
+               HvpAddFree(RegistryHive, Neighbor, NeighborCellIndex);
+            }
+            else
+               Neighbor->Size += Free->Size;
+
             if (CellType == Stable)
-               HvMarkCellDirty(RegistryHive,
-                               (HCELL_INDEX)((ULONG_PTR)Neighbor - (ULONG_PTR)Bin +
-                               Bin->FileOffset), FALSE);
+               HvMarkCellDirty(RegistryHive, NeighborCellIndex, FALSE);
+
             return;
          }
          Neighbor = (PHCELL)((ULONG_PTR)Neighbor + Neighbor->Size);