From: Gerald Schaefer <gerald.schae...@de.ibm.com>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

commit 97534127012f0e396eddea4691f4c9b170aed74b upstream.

Commit 61f77eda9bbf ("mm/hugetlb: reduce arch dependent code around
follow_huge_*") broke follow_huge_pmd() on s390, where pmd and pte
layout differ and using pte_page() on a huge pmd will return wrong
results.  Using pmd_page() instead fixes this.

All architectures that were touched by that commit have pmd_page()
defined, so this should not break anything on other architectures.

Fixes: 61f77eda "mm/hugetlb: reduce arch dependent code around follow_huge_*"
Signed-off-by: Gerald Schaefer <gerald.schae...@de.ibm.com>
Acked-by: Naoya Horiguchi <n-horigu...@ah.jp.nec.com>
Cc: Hugh Dickins <hu...@google.com>
Cc: Michal Hocko <mho...@suse.cz>, Andrea Arcangeli <aarca...@redhat.com>
Cc: Martin Schwidefsky <schwidef...@de.ibm.com>
Acked-by: David Rientjes <rient...@google.com>
Cc: <sta...@vger.kernel.org>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Jiri Slaby <jsl...@suse.cz>
---
 mm/hugetlb.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 424ee30fcd0d..c91c347bb3ea 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -3494,8 +3494,7 @@ retry:
        if (!pmd_huge(*pmd))
                goto out;
        if (pmd_present(*pmd)) {
-               page = pte_page(*(pte_t *)pmd) +
-                       ((address & ~PMD_MASK) >> PAGE_SHIFT);
+               page = pmd_page(*pmd) + ((address & ~PMD_MASK) >> PAGE_SHIFT);
                if (flags & FOLL_GET)
                        get_page(page);
        } else {
-- 
2.3.7

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to