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| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2016-11-10 10:46:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-11-11 08:12:37 -0800 |
| commit | c3901e722b2975666f42748340df798114742d6d (patch) | |
| tree | 9cd4508bd975e35b393982f3c61101c98c90dee6 /mm | |
| parent | dd111be69114cc867f8e826284559bfbc1c40e37 (diff) | |
| download | linux-c3901e722b2975666f42748340df798114742d6d.tar.gz linux-c3901e722b2975666f42748340df798114742d6d.tar.bz2 linux-c3901e722b2975666f42748340df798114742d6d.zip | |
mm: hwpoison: fix thp split handling in memory_failure()
When memory_failure() runs on a thp tail page after pmd is split, we
trigger the following VM_BUG_ON_PAGE():
page:ffffd7cd819b0040 count:0 mapcount:0 mapping: (null) index:0x1
flags: 0x1fffc000400000(hwpoison)
page dumped because: VM_BUG_ON_PAGE(!page_count(p))
------------[ cut here ]------------
kernel BUG at /src/linux-dev/mm/memory-failure.c:1132!
memory_failure() passed refcount and page lock from tail page to head
page, which is not needed because we can pass any subpage to
split_huge_page().
Fixes: 61f5d698cc97 ("mm: re-enable THP")
Link: http://lkml.kernel.org/r/1477961577-7183-1-git-send-email-n-horiguchi@ah.jp.nec.com
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: <stable@vger.kernel.org> [4.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory-failure.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index de88f33519c0..19e796d36a62 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1112,10 +1112,10 @@ int memory_failure(unsigned long pfn, int trapno, int flags) } if (!PageHuge(p) && PageTransHuge(hpage)) { - lock_page(hpage); - if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) { - unlock_page(hpage); - if (!PageAnon(hpage)) + lock_page(p); + if (!PageAnon(p) || unlikely(split_huge_page(p))) { + unlock_page(p); + if (!PageAnon(p)) pr_err("Memory failure: %#lx: non anonymous thp\n", pfn); else @@ -1126,9 +1126,7 @@ int memory_failure(unsigned long pfn, int trapno, int flags) put_hwpoison_page(p); return -EBUSY; } - unlock_page(hpage); - get_hwpoison_page(p); - put_hwpoison_page(hpage); + unlock_page(p); VM_BUG_ON_PAGE(!page_count(p), p); hpage = compound_head(p); } |