[sir_richard] 49209: [NTOS]: Fix multiple math/logic bugs in the PrototypePTE paths. Caught while trying to switch the Win32k GDI Handle Table to ARM3 sections.

Author: sir_richard
Date: Tue Oct 19 18:57:30 2010
New Revision: 49209

URL: http://svn.reactos.org/svn/reactos?rev=49209&view=rev
Log:
[NTOS]: Fix multiple math/logic bugs in the PrototypePTE paths. Caught while trying to
switch the Win32k GDI Handle Table to ARM3 sections.

Modified:
    trunk/reactos/ntoskrnl/mm/ARM3/miarm.h
    trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c

Modified: trunk/reactos/ntoskrnl/mm/ARM3/miarm.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/miarm.h?r…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/ARM3/miarm.h [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/ARM3/miarm.h [iso-8859-1] Tue Oct 19 18:57:30 2010
@@ -241,7 +241,7 @@
 //
 #define MiProtoPteToPte(x)                  \
     (PMMPTE)((ULONG_PTR)MmPagedPoolStart +  \
-             ((x)->u.Proto.ProtoAddressHigh | (x)->u.Proto.ProtoAddressLow))
+             (((x)->u.Proto.ProtoAddressHigh << 7) |
(x)->u.Proto.ProtoAddressLow))
 #endif
 
 //
@@ -624,10 +624,11 @@
      * lets us only use 28 bits for the adress of the PTE
      */
     Offset = (ULONG_PTR)PointerPte - (ULONG_PTR)MmPagedPoolStart;
-    
+
     /* 7 bits go in the "low", and the other 21 bits go in the "high"
*/
     NewPte->u.Proto.ProtoAddressLow = Offset & 0x7F;
-    NewPte->u.Proto.ProtoAddressHigh = Offset & 0xFFFFF80;
+    NewPte->u.Proto.ProtoAddressHigh = (Offset & 0xFFFFFF80) >> 7;
+    ASSERT(MiProtoPteToPte(NewPte) == PointerPte);
 }
 #endif
 

Modified: trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/mm/ARM3/pagfault.…
==============================================================================
--- trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c [iso-8859-1] (original)
+++ trunk/reactos/ntoskrnl/mm/ARM3/pagfault.c [iso-8859-1] Tue Oct 19 18:57:30 2010
@@ -805,21 +805,23 @@
             /* Get the prototype PTE! */
             ProtoPte = MiProtoPteToPte(&TempPte);
         }
-        
-        //
-        // We don't implement transition PTEs
-        //
-        ASSERT(TempPte.u.Soft.Transition == 0);
-        
-        /* Check for no-access PTE */
-        if (TempPte.u.Soft.Protection == MM_NOACCESS)
-        {
-            /* Bad boy, bad boy, whatcha gonna do, whatcha gonna do when ARM3 comes for
you! */
-            KeBugCheckEx(PAGE_FAULT_IN_NONPAGED_AREA,
-                         (ULONG_PTR)Address,
-                         StoreInstruction,
-                         (ULONG_PTR)TrapInformation,
-                         1);
+        else
+        {        
+            //
+            // We don't implement transition PTEs
+            //
+            ASSERT(TempPte.u.Soft.Transition == 0);
+        
+            /* Check for no-access PTE */
+            if (TempPte.u.Soft.Protection == MM_NOACCESS)
+            {
+                /* Bad boy, bad boy, whatcha gonna do, whatcha gonna do when ARM3 comes
for you! */
+                KeBugCheckEx(PAGE_FAULT_IN_NONPAGED_AREA,
+                             (ULONG_PTR)Address,
+                             StoreInstruction,
+                             (ULONG_PTR)TrapInformation,
+                             1);
+            }
         }
         
         /* Check for demand page */
@@ -874,8 +876,6 @@
 #endif
 
     /* First things first, is the PDE valid? */
-//    DPRINT1("The PDE we faulted on: %lx %lx\n", PointerPde,
MiAddressToPde(PTE_BASE));
-    //ASSERT(PointerPde != MiAddressToPde(PTE_BASE));
     ASSERT(PointerPde->u.Hard.LargePage == 0);
     if (PointerPde->u.Hard.Valid == 0)
     {
@@ -918,7 +918,6 @@
     if (TempPte.u.Long == (MM_READWRITE << MM_PTE_SOFTWARE_PROTECTION_BITS))
     {
         /* Resolve the fault */
-        //DPRINT1("VAD demand-zero fault: %p\n", Address);
         MiResolveDemandZeroFault(Address,
                                  PointerPte,
                                  CurrentProcess,