From afc27ab1aabd7e715abfbec509381ea1c8a04476 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Gardou?= <jerome.gardou@reactos.org>
Date: Mon, 7 Jun 2021 14:29:37 +0200
Subject: [PATCH] [NTOS:MM] Handle PT references for page table faults in
 MmAccessFault

Idea from Timo Kreuzer
---
 ntoskrnl/mm/ARM3/pagfault.c | 9 ++++++++-
 ntoskrnl/mm/ARM3/virtual.c  | 8 --------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/ntoskrnl/mm/ARM3/pagfault.c b/ntoskrnl/mm/ARM3/pagfault.c
index b6e2f9e8287..4656828a3b0 100644
--- a/ntoskrnl/mm/ARM3/pagfault.c
+++ b/ntoskrnl/mm/ARM3/pagfault.c
@@ -2314,7 +2314,14 @@ UserFault:
          * Check if this is a real user-mode address or actually a kernel-mode
          * page table for a user mode address
          */
-        if (Address <= MM_HIGHEST_USER_ADDRESS)
+        if (Address <= MM_HIGHEST_USER_ADDRESS
+#if _MI_PAGING_LEVELS >= 3
+            || MiIsUserPte(Address)
+#if _MI_PAGING_LEVELS == 4
+            || MiIsUserPde(Address)
+#endif
+#endif
+        )
         {
             /* Add an additional page table reference */
             MiIncrementPageTableReferences(Address);
diff --git a/ntoskrnl/mm/ARM3/virtual.c b/ntoskrnl/mm/ARM3/virtual.c
index 27e2daa4241..0910d080542 100644
--- a/ntoskrnl/mm/ARM3/virtual.c
+++ b/ntoskrnl/mm/ARM3/virtual.c
@@ -2532,10 +2532,6 @@ MiMakePdeExistAndMakeValid(IN PMMPDE PointerPde,
        //
        if (!PointerPpe->u.Hard.Valid)
        {
-#if _MI_PAGING_LEVELS == 4
-           if (PointerPpe->u.Long == 0)
-               MiIncrementPageTableReferences(PointerPde);
-#endif
            MiMakeSystemAddressValid(PointerPde, TargetProcess);
            ASSERT(PointerPpe->u.Hard.Valid == 1);
        }
@@ -2544,10 +2540,6 @@ MiMakePdeExistAndMakeValid(IN PMMPDE PointerPde,
        //
        // And finally, make the PDE itself valid.
        //
-#if _MI_PAGING_LEVELS >= 3
-       if (PointerPde->u.Long == 0)
-            MiIncrementPageTableReferences(PointerPte);
-#endif
        MiMakeSystemAddressValid(PointerPte, TargetProcess);
 
        /* Do not increment Page table refcount here for the PDE, this must be managed by caller */