From 4218091cb45f601b889cd032e39fe6878a426e70 Mon Sep 17 00:00:00 2001
From: Christian Borntraeger <borntraeger@de.ibm.com>
Date: Fri, 21 Nov 2014 16:21:56 +0100
Subject: [PATCH] mips/gup: Replace ACCESS_ONCE with READ_ONCE

ACCESS_ONCE does not work reliably on non-scalar types. For
example gcc 4.6 and 4.7 might remove the volatile tag for such
accesses during the SRA (scalar replacement of aggregates) step
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58145)

Change the gup code to replace ACCESS_ONCE with READ_ONCE.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 arch/mips/mm/gup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/mm/gup.c b/arch/mips/mm/gup.c
index 06ce17c2a905..8aa50e3f3fce 100644
--- a/arch/mips/mm/gup.c
+++ b/arch/mips/mm/gup.c
@@ -30,7 +30,7 @@ static inline pte_t gup_get_pte(pte_t *ptep)
 
 	return pte;
 #else
-	return ACCESS_ONCE(*ptep);
+	return READ_ONCE(*ptep);
 #endif
 }
 
-- 
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