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| author | Jianguo Wu <wujianguo@huawei.com> | 2013-12-18 17:08:54 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-18 19:04:52 -0800 |
| commit | a49ecbcd7b0d5a1cda7d60e03df402dd0ef76ac8 (patch) | |
| tree | 540f25e983c0ae135d94a7bd9e5e0008844ca19a /mm/memory-failure.c | |
| parent | 6815bf3f233e0b10c99a758497d5d236063b010b (diff) | |
| download | linux-a49ecbcd7b0d5a1cda7d60e03df402dd0ef76ac8.tar.gz linux-a49ecbcd7b0d5a1cda7d60e03df402dd0ef76ac8.tar.bz2 linux-a49ecbcd7b0d5a1cda7d60e03df402dd0ef76ac8.zip | |
mm/memory-failure.c: recheck PageHuge() after hugetlb page migrate successfully
After a successful hugetlb page migration by soft offline, the source
page will either be freed into hugepage_freelists or buddy(over-commit
page). If page is in buddy, page_hstate(page) will be NULL. It will
hit a NULL pointer dereference in dequeue_hwpoisoned_huge_page().
BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
IP: [<ffffffff81163761>] dequeue_hwpoisoned_huge_page+0x131/0x1d0
PGD c23762067 PUD c24be2067 PMD 0
Oops: 0000 [#1] SMP
So check PageHuge(page) after call migrate_pages() successfully.
Signed-off-by: Jianguo Wu <wujianguo@huawei.com>
Tested-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory-failure.c')
| -rw-r--r-- | mm/memory-failure.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index b7c171602ba1..db08af92c6fc 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1505,10 +1505,16 @@ static int soft_offline_huge_page(struct page *page, int flags) if (ret > 0) ret = -EIO; } else { - set_page_hwpoison_huge_page(hpage); - dequeue_hwpoisoned_huge_page(hpage); - atomic_long_add(1 << compound_order(hpage), - &num_poisoned_pages); + /* overcommit hugetlb page will be freed to buddy */ + if (PageHuge(page)) { + set_page_hwpoison_huge_page(hpage); + dequeue_hwpoisoned_huge_page(hpage); + atomic_long_add(1 << compound_order(hpage), + &num_poisoned_pages); + } else { + SetPageHWPoison(page); + atomic_long_inc(&num_poisoned_pages); + } } return ret; } |