ppc/hugetlbfs: 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 ppc/hugetlbfs code to replace ACCESS_ONCE with READ_ONCE.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 5ff4e07..620d0ec 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -978,7 +978,7 @@
*/
pdshift = PUD_SHIFT;
pudp = pud_offset(&pgd, ea);
- pud = ACCESS_ONCE(*pudp);
+ pud = READ_ONCE(*pudp);
if (pud_none(pud))
return NULL;
@@ -990,7 +990,7 @@
else {
pdshift = PMD_SHIFT;
pmdp = pmd_offset(&pud, ea);
- pmd = ACCESS_ONCE(*pmdp);
+ pmd = READ_ONCE(*pmdp);
/*
* A hugepage collapse is captured by pmd_none, because
* it mark the pmd none and do a hpte invalidate.