From 0bbdcf4d8b31deafd6a5aad8658af02894bd9152 Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Sun, 25 Jul 2010 00:50:03 +0000
Subject: [PATCH] [NTOSKRNL] Make MmIsAddressValid portable by using
 _MI_PAGING_LEVELS macro.

svn path=/trunk/; revision=48238
---
 reactos/ntoskrnl/include/internal/amd64/mm.h |  2 ++
 reactos/ntoskrnl/include/internal/i386/mm.h  |  6 ++++
 reactos/ntoskrnl/mm/ARM3/mmsup.c             | 34 +++++++++++---------
 reactos/ntoskrnl/mm/amd64/page.c             | 12 -------
 4 files changed, 27 insertions(+), 27 deletions(-)

diff --git a/reactos/ntoskrnl/include/internal/amd64/mm.h b/reactos/ntoskrnl/include/internal/amd64/mm.h
index 889c43e9684..c52132db0f6 100644
--- a/reactos/ntoskrnl/include/internal/amd64/mm.h
+++ b/reactos/ntoskrnl/include/internal/amd64/mm.h
@@ -4,6 +4,8 @@
 
 #pragma once
 
+#define _MI_PAGING_LEVELS 4
+
 /* Helper macros */
 #define PAGE_MASK(x)		((x)&(~0xfff))
 #define PAE_PAGE_MASK(x)	((x)&(~0xfffLL))
diff --git a/reactos/ntoskrnl/include/internal/i386/mm.h b/reactos/ntoskrnl/include/internal/i386/mm.h
index edd86bbaab4..1014884b099 100644
--- a/reactos/ntoskrnl/include/internal/i386/mm.h
+++ b/reactos/ntoskrnl/include/internal/i386/mm.h
@@ -7,6 +7,12 @@
 struct _EPROCESS;
 PULONG MmGetPageDirectory(VOID);
 
+#ifdef _PAE_
+#define _MI_PAGING_LEVELS 3
+#else
+#define _MI_PAGING_LEVELS 2
+#endif
+
 #define PAGE_MASK(x)		((x)&(~0xfff))
 #define PAE_PAGE_MASK(x)	((x)&(~0xfffLL))
 
diff --git a/reactos/ntoskrnl/mm/ARM3/mmsup.c b/reactos/ntoskrnl/mm/ARM3/mmsup.c
index b84c7a0492b..4410a390249 100644
--- a/reactos/ntoskrnl/mm/ARM3/mmsup.c
+++ b/reactos/ntoskrnl/mm/ARM3/mmsup.c
@@ -64,22 +64,26 @@ BOOLEAN
 NTAPI
 MmIsAddressValid(IN PVOID VirtualAddress)
 {
-    //
-    // Just check the Valid bit in the Address' PDE and PTE
-    //
-    if ((MiAddressToPde(VirtualAddress)->u.Hard.Valid == 0) ||
-        (MiAddressToPte(VirtualAddress)->u.Hard.Valid == 0))
-    {
-        //
-        // Attempting to access this page is guranteed to result in a page fault
-        //
-        return FALSE;
-    }
+#if _MI_PAGING_LEVELS >= 4
+    /* Check if the PXE is valid */
+    if (MiAddressToPxe(VirtualAddress)->u.Hard.Valid == 0) return FALSE;
+#endif
 
-    //
-    // This address is valid now, but it will only stay so if the caller holds
-    // the PFN lock
-    //
+#if _MI_PAGING_LEVELS >= 3
+    /* Check if the PPE is valid */
+    if (MiAddressToPpe(VirtualAddress)->u.Hard.Valid == 0) return FALSE;
+#endif
+
+#if _MI_PAGING_LEVELS >= 2
+    /* Check if the PDE is valid */
+    if (MiAddressToPde(VirtualAddress)->u.Hard.Valid == 0) return FALSE;
+#endif
+
+    /* Check if the PTE is valid */
+    if (MiAddressToPte(VirtualAddress)->u.Hard.Valid == 0) return FALSE;
+
+    /* This address is valid now, but it will only stay so if the caller holds
+     * the PFN lock */
     return TRUE;
 }
 
diff --git a/reactos/ntoskrnl/mm/amd64/page.c b/reactos/ntoskrnl/mm/amd64/page.c
index d9830b409e8..33cdeeb6c83 100644
--- a/reactos/ntoskrnl/mm/amd64/page.c
+++ b/reactos/ntoskrnl/mm/amd64/page.c
@@ -519,16 +519,4 @@ MmCreateProcessAddressSpace(IN ULONG MinWs,
     return 0;
 }
 
-BOOLEAN
-NTAPI
-_MmIsAddressValid(IN PVOID VirtualAddress)
-{
-    /* Check all four page table levels */
-    return (MiAddressToPxe(VirtualAddress)->u.Hard.Valid != 0 &&
-            MiAddressToPpe(VirtualAddress)->u.Hard.Valid != 0 &&
-            MiAddressToPde(VirtualAddress)->u.Hard.Valid != 0 &&
-            MiAddressToPte(VirtualAddress)->u.Hard.Valid != 0);
-}
-
-
 /* EOF */
-- 
2.17.1