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authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2015-02-11 15:25:32 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2015-02-11 17:06:01 -0800
commit9fbc1f635fd0bd28cb32550211bf095753ac637a (patch)
treeebd762c0d7f769087f82db00dc6a4f8e5506e6fe
parenta8bda28d87c38c6aa93de28ba5d30cc18e865a11 (diff)
mm/hugetlb: add migration entry check in __unmap_hugepage_range
If __unmap_hugepage_range() tries to unmap the address range over which hugepage migration is on the way, we get the wrong page because pte_page() doesn't work for migration entries. This patch simply clears the pte for migration entries as we do for hwpoison entries. Fixes: 290408d4a2 ("hugetlb: hugepage migration core") Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Hugh Dickins <hughd@google.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Nishanth Aravamudan <nacc@linux.vnet.ibm.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: <stable@vger.kernel.org> [2.6.36+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/hugetlb.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index c2970e7eb527..fd28d6ba5e5d 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2657,9 +2657,10 @@ again:
goto unlock;
/*
- * HWPoisoned hugepage is already unmapped and dropped reference
+ * Migrating hugepage or HWPoisoned hugepage is already
+ * unmapped and its refcount is dropped, so just clear pte here.
*/
- if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) {
+ if (unlikely(!pte_present(pte))) {
huge_pte_clear(mm, address, ptep);
goto unlock;
}