From af96e4438a4b34a257f5318a296e0b9e182e7ab9 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Fri, 15 Feb 2008 21:49:46 +0100
Subject: [PATCH] x86: CPA no alias checking for _NX
NX settings are not required to be consistent across alias mappings.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
arch/x86/mm/pageattr.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c
index 7b4a17236972..b8f53233151d 100644
--- a/arch/x86/mm/pageattr.c
+++ b/arch/x86/mm/pageattr.c
@@ -669,7 +669,7 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
pgprot_t mask_set, pgprot_t mask_clr)
{
struct cpa_data cpa;
- int ret, cache;
+ int ret, cache, checkalias;
/*
* Check, if we are requested to change a not supported
@@ -695,7 +695,10 @@ static int change_page_attr_set_clr(unsigned long addr, int numpages,
cpa.mask_clr = mask_clr;
cpa.flushtlb = 0;
- ret = __change_page_attr_set_clr(&cpa, 1);
+ /* No alias checking for _NX bit modifications */
+ checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
+
+ ret = __change_page_attr_set_clr(&cpa, checkalias);
/*
* Check whether we really changed something:
--
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