| From | Luis Henriques <> | Subject | [PATCH 3.16.y-ckt 130/180] mm/hugetlb: use pmd_page() in follow_huge_pmd() | Date | Thu, 7 May 2015 10:45:39 +0100 |
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3.16.7-ckt11 -stable review patch. If anyone has any objections, please let me know.
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From: Gerald Schaefer <gerald.schaefer@de.ibm.com>
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.schaefer@de.ibm.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@suse.cz>, Andrea Arcangeli <aarcange@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- mm/hugetlb.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5f217e906ff9..1e080a06e6ba 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3723,8 +3723,7 @@ 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 {
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