On Wed, Dec 03, 2014 at 11:30:16PM +0100, Christian Borntraeger wrote: > 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@xxxxxxxxxx> Acked-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > --- > arch/x86/mm/gup.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/x86/mm/gup.c b/arch/x86/mm/gup.c > index 207d9aef..d754782 100644 > --- a/arch/x86/mm/gup.c > +++ b/arch/x86/mm/gup.c > @@ -15,7 +15,7 @@ > static inline pte_t gup_get_pte(pte_t *ptep) > { > #ifndef CONFIG_X86_PAE > - return ACCESS_ONCE(*ptep); > + return READ_ONCE(*ptep); > #else > /* > * With get_user_pages_fast, we walk down the pagetables without taking > -- > 1.9.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
