From 244570a4180f7b79a95168e908dd34e3ecd75733 Mon Sep 17 00:00:00 2001
From: Hugh Dickins <hugh@veritas.com>
Date: Tue, 6 May 2008 20:49:23 +0100
Subject: [PATCH] --- yaml --- r: 96111 b: refs/heads/master c:
 aeed5fce37196e09b4dac3a1c00d8b7122e040ce h: refs/heads/master i:   96109:
 dae3ea2a021753e53e04b64986223992fc041359   96107:
 388ae6a7eb48aa31d6b23caaceca49b3c8dcfb65   96103:
 eadc0fa682b6fe8e4e6b68b20cdd8fef8374db9f   96095:
 ac6e388e46c5b6d88565063f0a60c060517b7602 v: v3

---
 [refs]                             | 2 +-
 trunk/arch/x86/mm/pgtable_32.c     | 7 -------
 trunk/include/asm-x86/pgtable_32.h | 9 +--------
 trunk/include/asm-x86/pgtable_64.h | 6 ++----
 trunk/mm/memory.c                  | 5 ++++-
 5 files changed, 8 insertions(+), 21 deletions(-)

diff --git a/[refs] b/[refs]
index 199272dbb333..41c09d5593b2 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: bb78be8397d3b0900af3d717672218ee3ea07985
+refs/heads/master: aeed5fce37196e09b4dac3a1c00d8b7122e040ce
diff --git a/trunk/arch/x86/mm/pgtable_32.c b/trunk/arch/x86/mm/pgtable_32.c
index 9ee007be9142..369cf065b6a4 100644
--- a/trunk/arch/x86/mm/pgtable_32.c
+++ b/trunk/arch/x86/mm/pgtable_32.c
@@ -172,10 +172,3 @@ void reserve_top_address(unsigned long reserve)
 	__FIXADDR_TOP = -reserve - PAGE_SIZE;
 	__VMALLOC_RESERVE += reserve;
 }
-
-int pmd_bad(pmd_t pmd)
-{
-	WARN_ON_ONCE(pmd_bad_v1(pmd) != pmd_bad_v2(pmd));
-
-	return pmd_bad_v1(pmd);
-}
diff --git a/trunk/include/asm-x86/pgtable_32.h b/trunk/include/asm-x86/pgtable_32.h
index 577ab79c4c27..d7f0403bbecb 100644
--- a/trunk/include/asm-x86/pgtable_32.h
+++ b/trunk/include/asm-x86/pgtable_32.h
@@ -88,14 +88,7 @@ extern unsigned long pg0[];
 /* To avoid harmful races, pmd_none(x) should check only the lower when PAE */
 #define pmd_none(x)	(!(unsigned long)pmd_val((x)))
 #define pmd_present(x)	(pmd_val((x)) & _PAGE_PRESENT)
-
-extern int pmd_bad(pmd_t pmd);
-
-#define pmd_bad_v1(x)							\
-	(_KERNPG_TABLE != (pmd_val((x)) & ~(PAGE_MASK | _PAGE_USER)))
-#define	pmd_bad_v2(x)							\
-	(_KERNPG_TABLE != (pmd_val((x)) & ~(PAGE_MASK | _PAGE_USER |	\
-					    _PAGE_PSE | _PAGE_NX)))
+#define pmd_bad(x) ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 
 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
 
diff --git a/trunk/include/asm-x86/pgtable_64.h b/trunk/include/asm-x86/pgtable_64.h
index a3bbf8766c1d..efe83dcbd412 100644
--- a/trunk/include/asm-x86/pgtable_64.h
+++ b/trunk/include/asm-x86/pgtable_64.h
@@ -158,14 +158,12 @@ static inline unsigned long pgd_bad(pgd_t pgd)
 
 static inline unsigned long pud_bad(pud_t pud)
 {
-	return pud_val(pud) &
-		~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER | _PAGE_PSE | _PAGE_NX);
+	return pud_val(pud) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER);
 }
 
 static inline unsigned long pmd_bad(pmd_t pmd)
 {
-	return pmd_val(pmd) &
-		~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER | _PAGE_PSE | _PAGE_NX);
+	return pmd_val(pmd) & ~(PTE_MASK | _KERNPG_TABLE | _PAGE_USER);
 }
 
 #define pte_none(x)	(!pte_val((x)))
diff --git a/trunk/mm/memory.c b/trunk/mm/memory.c
index bbab1e37055e..48c122d42ed7 100644
--- a/trunk/mm/memory.c
+++ b/trunk/mm/memory.c
@@ -969,7 +969,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
 		goto no_page_table;
 	
 	pmd = pmd_offset(pud, address);
-	if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
+	if (pmd_none(*pmd))
 		goto no_page_table;
 
 	if (pmd_huge(*pmd)) {
@@ -978,6 +978,9 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
 		goto out;
 	}
 
+	if (unlikely(pmd_bad(*pmd)))
+		goto no_page_table;
+
 	ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
 	if (!ptep)
 		goto out;