From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Fri, 4 Jul 2008 05:10:18 +0000 (-0700)
Subject: xen: fix address truncation in pte mfn<->pfn conversion
X-Git-Tag: v2.6.26-rc9~9^2
X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d8355aca23863be659ec5b7e0393cfbfa91ec221;p=linux-2.6

xen: fix address truncation in pte mfn<->pfn conversion

When converting the page number in a pte/pmd/pud/pgd between
machine and pseudo-physical addresses, the converted result was
being truncated at 32-bits.  This caused failures on machines
with more than 4G of physical memory.

Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: "Christopher S. Aker" <caker@theshore.net>
Cc: Ian Campbell <Ian.Campbell@eu.citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index df40bf74ea..4e527e7893 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -185,7 +185,7 @@ static pteval_t pte_mfn_to_pfn(pteval_t val)
 	if (val & _PAGE_PRESENT) {
 		unsigned long mfn = (val & PTE_MASK) >> PAGE_SHIFT;
 		pteval_t flags = val & ~PTE_MASK;
-		val = (mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
+		val = ((pteval_t)mfn_to_pfn(mfn) << PAGE_SHIFT) | flags;
 	}
 
 	return val;
@@ -196,7 +196,7 @@ static pteval_t pte_pfn_to_mfn(pteval_t val)
 	if (val & _PAGE_PRESENT) {
 		unsigned long pfn = (val & PTE_MASK) >> PAGE_SHIFT;
 		pteval_t flags = val & ~PTE_MASK;
-		val = (pfn_to_mfn(pfn) << PAGE_SHIFT) | flags;
+		val = ((pteval_t)pfn_to_mfn(pfn) << PAGE_SHIFT) | flags;
 	}
 
 	return val;