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authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2016-07-27 01:24:03 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-07-27 02:19:19 +0300
commit337d9abf1cd1a59645d91b6d0b1685a476b81978 (patch)
treeaace71b1608dfbde1c4c35bd03cbdac60fe1f64a /mm/gup.c
parente3a2713c3cfa9c41fac57447533079d8da23319b (diff)
downloadlinux-337d9abf1cd1a59645d91b6d0b1685a476b81978.tar.xz
mm: thp: check pmd_trans_unstable() after split_huge_pmd()
split_huge_pmd() doesn't guarantee that the pmd is normal pmd pointing to pte entries, which can be checked with pmd_trans_unstable(). Some callers make this assertion and some do it differently and some not, so let's do it in a unified manner. Link: http://lkml.kernel.org/r/1464741400-12143-1-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/gup.c')
-rw-r--r--mm/gup.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/gup.c b/mm/gup.c
index c057784c8444..dee142e100f4 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -279,6 +279,8 @@ struct page *follow_page_mask(struct vm_area_struct *vma,
spin_unlock(ptl);
ret = 0;
split_huge_pmd(vma, pmd, address);
+ if (pmd_trans_unstable(pmd))
+ ret = -EBUSY;
} else {
get_page(page);
spin_unlock(ptl);