Attachment 288771 Details for Bug 294811 – xen-unstable 13998:d2dff286994d ported to 2.6.9-67.EL

[patch] xen-unstable 13998:d2dff286994d ported to 2.6.9-67.EL

xen-unstable-13998-d2dff286994d (text/plain), 16.90 KB, created by Ian Campbell on 2007-12-14 09:08:09 UTC

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Creator: Ian Campbell

Created: 2007-12-14 09:08:09 UTC

Size: 16.90 KB

patch

obsolete

># HG changeset patch
># User kfraser@localhost.localdomain
># Node ID d2dff286994d52b82111499c99a2c0e070104734
># Parent  89ca591a2c211caf487d20261692ef4a40170cf7
>linux/x86: Adjust and fix page table handling.
>
>Ensure that all and only those page table entries that have their
>present bit set undergo p2m/m2p translation in all relevant places.
>This should fix migration issues with _PAGE_PROTNONE pages which
>previously could retain MFNs in PTEs while having the present bit
>clear (and thus were not getting (un)canonicalized during save/
>restore).
>
>Many thanks to Keir Fraser for his analysis, suggestions, and
>corrections.
>
>Signed-off-by: Jan Beulich <jbeulich@novell.com>
>xen-unstable changeset: 13998:d2dff286994d52b82111499c99a2c0e070104734
>xen-unstable date: Tue Feb 20 09:33:14 2007 +0000
>
>Index: linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/maddr.h
>===================================================================
>--- linux-2.6.9-67.EL.orig/include/asm-i386/mach-xen/asm/maddr.h	2007-11-29 12:08:51.000000000 +0000
>+++ linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/maddr.h	2007-11-29 12:10:35.000000000 +0000
>@@ -21,6 +21,7 @@
> #ifdef CONFIG_XEN
> 
> extern unsigned long *phys_to_machine_mapping;
>+extern unsigned long  max_mapnr;
> 
> #undef machine_to_phys_mapping
> extern unsigned long *machine_to_phys_mapping;
>@@ -30,20 +31,20 @@
> {
> 	if (xen_feature(XENFEAT_auto_translated_physmap))
> 		return pfn;
>-	return phys_to_machine_mapping[(unsigned int)(pfn)] &
>-		~FOREIGN_FRAME_BIT;
>+	BUG_ON(max_mapnr && pfn >= max_mapnr);
>+	return phys_to_machine_mapping[pfn] & ~FOREIGN_FRAME_BIT;
> }
> 
> static inline int phys_to_machine_mapping_valid(unsigned long pfn)
> {
> 	if (xen_feature(XENFEAT_auto_translated_physmap))
> 		return 1;
>+	BUG_ON(max_mapnr && pfn >= max_mapnr);
> 	return (phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY);
> }
> 
> static inline unsigned long mfn_to_pfn(unsigned long mfn)
> {
>-	extern unsigned long max_mapnr;
> 	unsigned long pfn;
> 
> 	if (xen_feature(XENFEAT_auto_translated_physmap))
>@@ -92,7 +93,6 @@
>  */
> static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
> {
>-	extern unsigned long max_mapnr;
> 	unsigned long pfn = mfn_to_pfn(mfn);
> 	if ((pfn < max_mapnr)
> 	    && !xen_feature(XENFEAT_auto_translated_physmap)
>@@ -103,6 +103,7 @@
> 
> static inline void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> {
>+	BUG_ON(pfn >= max_mapnr);
> 	if (xen_feature(XENFEAT_auto_translated_physmap)) {
> 		BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
> 		return;
>@@ -124,6 +125,20 @@
> 	return phys;
> }
> 
>+#ifdef CONFIG_X86_PAE
>+static inline paddr_t pte_phys_to_machine(paddr_t phys)
>+{
>+	/*
>+	 * In PAE mode, the NX bit needs to be dealt with in the value
>+	 * passed to pfn_to_mfn(). On x86_64, we need to mask it off,
>+	 * but for i386 the conversion to ulong for the argument will
>+	 * clip it off.
>+	 */
>+	maddr_t machine = pfn_to_mfn(phys >> PAGE_SHIFT);
>+	machine = (machine << PAGE_SHIFT) | (phys & ~PHYSICAL_PAGE_MASK);
>+	return machine;
>+}
>+
> static inline paddr_t pte_machine_to_phys(maddr_t machine)
> {
> 	/*
>@@ -136,6 +151,7 @@
> 	phys = (phys << PAGE_SHIFT) | (machine & ~PHYSICAL_PAGE_MASK);
> 	return phys;
> }
>+#endif
> 
> #else /* !CONFIG_XEN */
> 
>@@ -146,7 +162,6 @@
> #define phys_to_machine_mapping_valid(pfn) (1)
> #define phys_to_machine(phys) ((maddr_t)(phys))
> #define machine_to_phys(mach) ((paddr_t)(mach))
>-#define pte_machine_to_phys(mach) ((paddr_t)(mach))
> 
> #endif /* !CONFIG_XEN */
> 
>Index: linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/page.h
>===================================================================
>--- linux-2.6.9-67.EL.orig/include/asm-i386/mach-xen/asm/page.h	2007-11-29 12:05:57.000000000 +0000
>+++ linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/page.h	2007-11-29 12:15:09.000000000 +0000
>@@ -32,6 +32,13 @@
> #include <xen/features.h>
> #include <xen/foreign_page.h>
> 
>+/*
>+ * Need to repeat this here in order to not include pgtable.h (which in turn
>+ * depends on definitions made here), but to be able to use the symbolic
>+ * below. The preprocessor will warn if the two definitions aren't identical.
>+ */
>+#define _PAGE_PRESENT	0x001
>+
> #define arch_free_page(_page,_order)			\
> ({	int foreign = PageForeign(_page);		\
> 	if (foreign)					\
>@@ -80,40 +87,38 @@
> #define pgprot_val(x)	((x).pgprot)
> #include <asm/maddr.h>
> #define __pte(x) ({ unsigned long long _x = (x);        \
>-    if (_x & 1) _x = phys_to_machine(_x);               \
>+    if (_x & _PAGE_PRESENT) _x = pte_phys_to_machine(_x);   \
>     ((pte_t) {(unsigned long)(_x), (unsigned long)(_x>>32)}); })
> #define __pgd(x) ({ unsigned long long _x = (x); \
>-    (((_x)&1) ? ((pgd_t) {phys_to_machine(_x)}) : ((pgd_t) {(_x)})); })
>+    (pgd_t) {((_x) & _PAGE_PRESENT) ? pte_phys_to_machine(_x) : (_x)}; })
> #define __pmd(x) ({ unsigned long long _x = (x); \
>-    (((_x)&1) ? ((pmd_t) {phys_to_machine(_x)}) : ((pmd_t) {(_x)})); })
>+    (pmd_t) {((_x) & _PAGE_PRESENT) ? pte_phys_to_machine(_x) : (_x)}; })
>+static inline unsigned long long pte_val_ma(pte_t x)
>+{
>+	return ((unsigned long long)x.pte_high << 32) | x.pte_low;
>+}
> static inline unsigned long long pte_val(pte_t x)
> {
>-	unsigned long long ret;
>-
>-	if (x.pte_low) {
>-		ret = x.pte_low | (unsigned long long)x.pte_high << 32;
>-		ret = pte_machine_to_phys(ret) | 1;
>-	} else {
>-		ret = 0;
>-	}
>+	unsigned long long ret = pte_val_ma(x);
>+	if (x.pte_low & _PAGE_PRESENT) ret = pte_machine_to_phys(ret);
> 	return ret;
> }
> static inline unsigned long long pmd_val(pmd_t x)
> {
> 	unsigned long long ret = x.pmd;
>-	if (ret) ret = pte_machine_to_phys(ret) | 1;
>+#ifdef CONFIG_XEN_COMPAT_030002
>+	if (ret) ret = pte_machine_to_phys(ret) | _PAGE_PRESENT;
>+#else
>+	if (ret & _PAGE_PRESENT) ret = pte_machine_to_phys(ret);
>+#endif
> 	return ret;
> }
> static inline unsigned long long pgd_val(pgd_t x)
> {
> 	unsigned long long ret = x.pgd;
>-	if (ret) ret = pte_machine_to_phys(ret) | 1;
>+	if (ret & _PAGE_PRESENT) ret = pte_machine_to_phys(ret);
> 	return ret;
> }
>-static inline unsigned long long pte_val_ma(pte_t x)
>-{
>-	return (unsigned long long)x.pte_high << 32 | x.pte_low;
>-}
> #define HPAGE_SHIFT	21
> #else
> #define nx_enabled 0
>@@ -124,18 +129,18 @@
> #define pgprot_val(x)	((x).pgprot)
> #include <asm/maddr.h>
> #define boot_pte_t pte_t /* or would you rather have a typedef */
>-#define pte_val(x)	(((x).pte_low & 1) ? \
>-			 pte_machine_to_phys((x).pte_low) : \
>+#define pte_val(x)	(((x).pte_low & _PAGE_PRESENT) ? \
>+			 machine_to_phys((x).pte_low) : \
> 			 (x).pte_low)
> #define pte_val_ma(x)	((x).pte_low)
> #define __pte(x) ({ unsigned long _x = (x); \
>-    (((_x)&1) ? ((pte_t) {phys_to_machine(_x)}) : ((pte_t) {(_x)})); })
>+    (pte_t) {((_x) & _PAGE_PRESENT) ? phys_to_machine(_x) : (_x)}; })
> #define __pgd(x) ({ unsigned long _x = (x); \
>-    (((_x)&1) ? ((pgd_t) {phys_to_machine(_x)}) : ((pgd_t) {(_x)})); })
>+    (pgd_t) {((_x) & _PAGE_PRESENT) ? phys_to_machine(_x) : (_x)}; })
> static inline unsigned long pgd_val(pgd_t x)
> {
> 	unsigned long ret = x.pgd;
>-	if (ret) ret = pte_machine_to_phys(ret) | 1;
>+	if (ret & _PAGE_PRESENT) ret = machine_to_phys(ret);
> 	return ret;
> }
> #define HPAGE_SHIFT	22
>@@ -155,7 +160,7 @@
> #define __pmd(x) ({ unsigned long _x = (x); \
> 	(((_x)&1) ? ((pmd_t) {phys_to_machine(_x)}) : ((pmd_t) {(_x)})); })
> #endif
>-#define PTE_MASK	PAGE_MASK
>+#define PTE_MASK	PHYSICAL_PAGE_MASK
> 
> #ifdef CONFIG_HUGETLB_PAGE
> #define HPAGE_SIZE	((1UL) << HPAGE_SHIFT)
>Index: linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/pgtable-2level.h
>===================================================================
>--- linux-2.6.9-67.EL.orig/include/asm-i386/mach-xen/asm/pgtable-2level.h	2007-11-26 10:52:23.000000000 +0000
>+++ linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/pgtable-2level.h	2007-11-29 12:13:54.000000000 +0000
>@@ -72,10 +72,14 @@
> 	mm_track(ptep);
> 	return __pte_ma(xchg(&(ptep)->pte_low, 0));
> }
>-#define pte_mfn(_pte)		((_pte).pte_low >> PAGE_SHIFT)
>-#define pte_pfn(_pte)		mfn_to_local_pfn(pte_mfn(_pte))
> #define pte_same(a, b)		((a).pte_low == (b).pte_low)
>-#define pte_page(x)		pfn_to_page(pte_pfn(x))
>+#define __pte_mfn(_pte)		((_pte).pte_low >> PAGE_SHIFT)
>+#define pte_mfn(_pte)		((_pte).pte_low & _PAGE_PRESENT ? \
>+				__pte_mfn(_pte) : pfn_to_mfn(__pte_mfn(_pte)))
>+#define pte_pfn(_pte)		((_pte).pte_low & _PAGE_PRESENT ? \
>+				mfn_to_local_pfn(__pte_mfn(_pte)) : __pte_mfn(_pte))
>+
>+#define pte_page(x) 		pfn_to_page(pte_pfn(x))
> #define pte_none(x)		(!(x).pte_low)
> #define pfn_pte(pfn, prot)	__pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
> #define pfn_pmd(pfn, prot)	__pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
>Index: linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/pgtable-3level.h
>===================================================================
>--- linux-2.6.9-67.EL.orig/include/asm-i386/mach-xen/asm/pgtable-3level.h	2007-11-26 10:52:23.000000000 +0000
>+++ linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/pgtable-3level.h	2007-11-29 12:17:59.000000000 +0000
>@@ -146,20 +146,24 @@
> 	return !pte.pte_low && !pte.pte_high;
> }
> 
>-#define pte_mfn(_pte)	(((_pte).pte_low >> PAGE_SHIFT) |\
>-			(((_pte).pte_high & 0xfff) << (32-PAGE_SHIFT)))
>-#define pte_pfn(_pte)	mfn_to_local_pfn(pte_mfn(_pte))
>+#define __pte_mfn(_pte) (((_pte).pte_low >> PAGE_SHIFT) | \
>+			 ((_pte).pte_high << (32-PAGE_SHIFT)))
>+#define pte_mfn(_pte) ((_pte).pte_low & _PAGE_PRESENT ? \
>+	__pte_mfn(_pte) : pfn_to_mfn(__pte_mfn(_pte)))
>+#define pte_pfn(_pte) ((_pte).pte_low & _PAGE_PRESENT ? \
>+	mfn_to_local_pfn(__pte_mfn(_pte)) : __pte_mfn(_pte))
> 
> extern unsigned long long __supported_pte_mask;
> 
> static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
> {
>-	return pfn_pte_ma(pfn_to_mfn(page_nr), pgprot);
>+	return __pte((((unsigned long long)page_nr << PAGE_SHIFT) |
>+			pgprot_val(pgprot)) & __supported_pte_mask);
> }
> 
> static inline pmd_t pfn_pmd(unsigned long page_nr, pgprot_t pgprot)
> {
>-	return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) | \
>+	return __pmd((((unsigned long long)page_nr << PAGE_SHIFT) |
> 			pgprot_val(pgprot)) & __supported_pte_mask);
> }
> 
>Index: linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/pgtable.h
>===================================================================
>--- linux-2.6.9-67.EL.orig/include/asm-i386/mach-xen/asm/pgtable.h	2007-11-26 10:52:23.000000000 +0000
>+++ linux-2.6.9-67.EL/include/asm-i386/mach-xen/asm/pgtable.h	2007-11-29 12:10:35.000000000 +0000
>@@ -294,18 +294,19 @@
> 
> static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
> {
>-	pte.pte_low &= _PAGE_CHG_MASK;
>-	pte.pte_low |= pgprot_val(newprot);
>-#ifdef CONFIG_X86_PAE
> 	/*
>-	 * Chop off the NX bit (if present), and add the NX portion of
>-	 * the newprot (if present):
>+	 * Since this might change the present bit (which controls whether
>+	 * a pte_t object has undergone p2m translation), we must use
>+	 * pte_val() on the input pte and __pte() for the return value.
> 	 */
>-	pte.pte_high &= ~(1 << (_PAGE_BIT_NX - 32));
>-	pte.pte_high |= (pgprot_val(newprot) >> 32) & \
>-					(__supported_pte_mask >> 32);
>+	paddr_t pteval = pte_val(pte);
>+
>+	pteval &= _PAGE_CHG_MASK;
>+	pteval |= pgprot_val(newprot);
>+#ifdef CONFIG_X86_PAE
>+	pteval &= __supported_pte_mask;
> #endif
>-	return pte;
>+	return __pte(pteval);
> }
> 
> #define page_pte(page) page_pte_prot(page, __pgprot(0))
>Index: linux-2.6.9-67.EL/include/asm-x86_64/mach-xen/asm/maddr.h
>===================================================================
>--- linux-2.6.9-67.EL.orig/include/asm-x86_64/mach-xen/asm/maddr.h	2007-11-29 12:08:51.000000000 +0000
>+++ linux-2.6.9-67.EL/include/asm-x86_64/mach-xen/asm/maddr.h	2007-11-29 12:10:35.000000000 +0000
>@@ -25,14 +25,15 @@
> {
> 	if (xen_feature(XENFEAT_auto_translated_physmap))
> 		return pfn;
>-	return phys_to_machine_mapping[(unsigned int)(pfn)] &
>-		~FOREIGN_FRAME_BIT;
>+	BUG_ON(end_pfn && pfn >= end_pfn);
>+	return phys_to_machine_mapping[pfn] & ~FOREIGN_FRAME_BIT;
> }
> 
> static inline int phys_to_machine_mapping_valid(unsigned long pfn)
> {
> 	if (xen_feature(XENFEAT_auto_translated_physmap))
> 		return 1;
>+	BUG_ON(end_pfn && pfn >= end_pfn);
> 	return (phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY);
> }
> 
>@@ -96,6 +97,7 @@
> 
> static inline void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
> {
>+	BUG_ON(pfn >= end_pfn);
> 	if (xen_feature(XENFEAT_auto_translated_physmap)) {
> 		BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
> 		return;
>@@ -117,6 +119,14 @@
> 	return phys;
> }
> 
>+static inline paddr_t pte_phys_to_machine(paddr_t phys)
>+{
>+	maddr_t machine;
>+	machine = pfn_to_mfn((phys & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT);
>+	machine = (machine << PAGE_SHIFT) | (phys & ~PHYSICAL_PAGE_MASK);
>+	return machine;
>+}
>+
> static inline paddr_t pte_machine_to_phys(maddr_t machine)
> {
> 	paddr_t phys;
>@@ -134,7 +144,6 @@
> #define phys_to_machine_mapping_valid(pfn) (1)
> #define phys_to_machine(phys) ((maddr_t)(phys))
> #define machine_to_phys(mach) ((paddr_t)(mach))
>-#define pte_machine_to_phys(mach) ((paddr_t)(mach))
> 
> #endif /* !CONFIG_XEN */
> 
>Index: linux-2.6.9-67.EL/include/asm-x86_64/mach-xen/asm/page.h
>===================================================================
>--- linux-2.6.9-67.EL.orig/include/asm-x86_64/mach-xen/asm/page.h	2007-11-29 12:08:39.000000000 +0000
>+++ linux-2.6.9-67.EL/include/asm-x86_64/mach-xen/asm/page.h	2007-11-29 12:24:51.000000000 +0000
>@@ -12,6 +12,13 @@
> #include <xen/interface/xen.h> 
> #include <xen/foreign_page.h>
> 
>+/*
>+ * Need to repeat this here in order to not include pgtable.h (which in turn
>+ * depends on definitions made here), but to be able to use the symbolic
>+ * below. The preprocessor will warn if the two definitions aren't identical.
>+ */
>+#define _PAGE_PRESENT	0x001
>+
> #define arch_free_page(_page,_order)			\
> ({	int foreign = PageForeign(_page);		\
> 	if (foreign)					\
>@@ -110,21 +117,26 @@
> 	return phys;
> }
> 
>-#define pte_val(x)	(((x).pte & 1) ? pte_machine_to_phys((x).pte) : \
>+#define pte_val(x)	(((x).pte & _PAGE_PRESENT) ? \
>+			 pte_machine_to_phys((x).pte) : \
> 			 (x).pte)
> #define pte_val_ma(x)	((x).pte)
> 
> static inline unsigned long pmd_val(pmd_t x)
> {
> 	unsigned long ret = x.pmd;
>-	if (ret) ret = pte_machine_to_phys(ret);
>+#ifdef CONFIG_XEN_COMPAT_030002
>+	if (ret) ret = pte_machine_to_phys(ret) | _PAGE_PRESENT;
>+#else
>+	if (ret & _PAGE_PRESENT) ret = pte_machine_to_phys(ret);
>+#endif
> 	return ret;
> }
> 
> static inline unsigned long pgd_val(pgd_t x)
> {
> 	unsigned long ret = x.pgd;
>-	if (ret) ret = pte_machine_to_phys(ret);
>+	if (ret & _PAGE_PRESENT) ret = pte_machine_to_phys(ret);
> 	return ret;
> }
> 
>@@ -141,19 +153,19 @@
> 
> static inline pte_t __pte(unsigned long x)
> {
>-	if (x & 1) x = phys_to_machine(x);
>+	if (x & _PAGE_PRESENT) x = pte_phys_to_machine(x);
> 	return ((pte_t) { (x) });
> }
> 
> static inline pmd_t __pmd(unsigned long x)
> {
>-	if ((x & 1)) x = phys_to_machine(x);
>+	if (x & _PAGE_PRESENT) x = pte_phys_to_machine(x);
> 	return ((pmd_t) { (x) });
> }
> 
> static inline pgd_t __pgd(unsigned long x)
> {
>-	if ((x & 1)) x = phys_to_machine(x);
>+	if (x & _PAGE_PRESENT) x = pte_phys_to_machine(x);
> 	return ((pgd_t) { (x) });
> }
> 
>Index: linux-2.6.9-67.EL/include/asm-x86_64/mach-xen/asm/pgtable.h
>===================================================================
>--- linux-2.6.9-67.EL.orig/include/asm-x86_64/mach-xen/asm/pgtable.h	2007-11-26 10:52:23.000000000 +0000
>+++ linux-2.6.9-67.EL/include/asm-x86_64/mach-xen/asm/pgtable.h	2007-11-29 12:22:22.000000000 +0000
>@@ -285,17 +285,20 @@
> 
> #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))	/* FIXME: is this
> 						   right? */
>-#define pte_mfn(_pte)	(((_pte).pte & PTE_MASK) >> PAGE_SHIFT)
>-#define pte_pfn(_pte)	mfn_to_local_pfn(pte_mfn(_pte))
>+#define __pte_mfn(_pte) (((_pte).pte & PTE_MASK) >> PAGE_SHIFT)
>+#define pte_mfn(_pte) ((_pte).pte & _PAGE_PRESENT ? \
>+	__pte_mfn(_pte) : pfn_to_mfn(__pte_mfn(_pte)))
>+#define pte_pfn(_pte) ((_pte).pte & _PAGE_PRESENT ? \
>+	mfn_to_local_pfn(__pte_mfn(_pte)) : __pte_mfn(_pte))
>+
> #define pte_page(x)	pfn_to_page(pte_pfn(x))
> 
> static inline pte_t pfn_pte(unsigned long page_nr, pgprot_t pgprot)
> {
>-	pte_t pte;
>-	(pte).pte = (pfn_to_mfn(page_nr) << PAGE_SHIFT);
>-	(pte).pte |= pgprot_val(pgprot);
>-	(pte).pte &= __supported_pte_mask;
>-	return pte;
>+	unsigned long pte = page_nr << PAGE_SHIFT;
>+	pte |= pgprot_val(pgprot);
>+	pte &= __supported_pte_mask;
>+	return __pte(pte);
> }
> 
> #define pfn_pte_ma(pfn, prot)  __pte_ma((((pfn) << PAGE_SHIFT) | pgprot_val(prot)) & __supported_pte_mask)
>@@ -464,18 +467,25 @@
> /* physical address -> PTE */
> static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
> { 
>-	pte_t pte;
>-	(pte).pte = physpage | pgprot_val(pgprot); 
>-	return pte; 
>+	unsigned long pteval;
>+	pteval = physpage | pgprot_val(pgprot);
>+	return __pte(pteval);
> }
>  
> /* Change flags of a PTE */
> extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
> { 
>-	(pte).pte &= _PAGE_CHG_MASK;
>-	(pte).pte |= pgprot_val(newprot);
>-	(pte).pte &= __supported_pte_mask;
>-       return pte; 
>+	/*
>+	 * Since this might change the present bit (which controls whether
>+	 * a pte_t object has undergone p2m translation), we must use
>+	 * pte_val() on the input pte and __pte() for the return value.
>+	 */
>+	unsigned long pteval = pte_val(pte);
>+
>+	pteval &= _PAGE_CHG_MASK;
>+	pteval |= pgprot_val(newprot);
>+	pteval &= __supported_pte_mask;
>+	return __pte(pteval);
> }
> 
> #define pte_index(address) \

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Attachments on bug 294811: 198411 | 288051 | 288751 | 288761 | 288771 | 288781 | 288791 | 288801