Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit da1a288d authored by Christian Borntraeger's avatar Christian Borntraeger
Browse files

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: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent 5ee07612

arch/powerpc/mm/hugetlbpage.c

+2 −2
Original line number Diff line number Diff line
@@ -978,7 +978,7 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift 
		 */

		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 @@ pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift 
		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.