[PATCH 5/8] mips/gup: Replace ACCESS_ONCE with READ_ONCE

From: Christian Borntraeger
Date: Thu Dec 11 2014 - 09:07:41 EST

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

Change the gup code to replace ACCESS_ONCE with READ_ONCE.

Signed-off-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>
Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
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 06ce17c..8aa50e3 100644
--- a/arch/mips/mm/gup.c
+++ b/arch/mips/mm/gup.c
@@ -30,7 +30,7 @@ retry:

return pte;
- return ACCESS_ONCE(*ptep);
+ return READ_ONCE(*ptep);


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