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authorNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>2015-02-11 15:25:32 -0800
committerBen Hutchings <ben@decadent.org.uk>2015-05-09 23:16:16 +0100
commit73c67a84ebf1ecadb8f7d44e0a1ad668b453e9ae (patch)
treebdd5be45dac0fb31089ea271faeb9d5f463ad520 /mm
parent9e725572445374fe05d80478f4c4ff9631f9a59c (diff)
mm/hugetlb: add migration entry check in __unmap_hugepage_range
commit 9fbc1f635fd0bd28cb32550211bf095753ac637a upstream. 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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 3.2: adjust context and comment, as we're checking after the PTE has been cleared] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'mm')
-rw-r--r--mm/hugetlb.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index dcc6780533e6..26922dae449a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2418,9 +2418,10 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
continue;
/*
- * HWPoisoned hugepage is already unmapped and dropped reference
+ * Migrating hugepage or HWPoisoned hugepage is already
+ * unmapped and its refcount is dropped
*/
- if (unlikely(is_hugetlb_entry_hwpoisoned(pte)))
+ if (unlikely(!pte_present(pte)))
continue;
page = pte_page(pte);