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| author | Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> | 2015-08-06 15:47:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-08-07 04:39:41 +0300 |
| commit | 98ed2b0052e68420f1bad6c81e3f2600d25023e7 (patch) | |
| tree | 6cd4c68bc6b5ff247305b802d402113df3d494ff /mm | |
| parent | a209ef09af0dc921311d0cc4a1d4f926321d91b8 (diff) | |
| download | linux-stable-98ed2b0052e68420f1bad6c81e3f2600d25023e7.tar.gz linux-stable-98ed2b0052e68420f1bad6c81e3f2600d25023e7.tar.bz2 linux-stable-98ed2b0052e68420f1bad6c81e3f2600d25023e7.zip | |
mm/memory-failure: give up error handling for non-tail-refcounted thp
"non anonymous thp" case is still racy with freeing thp, which causes
panic due to put_page() for refcount-0 page. It seems that closing up
this race might be hard (and/or not worth doing,) so let's give up the
error handling for this case.
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Dean Nelson <dnelson@redhat.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Hugh Dickins <hughd@google.com>
Cc: David Rientjes <rientjes@google.com>
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 | 21 |
1 files changed, 12 insertions, 9 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index f72d2fad0b90..cd985530f102 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -909,6 +909,18 @@ int get_hwpoison_page(struct page *page) * directly for tail pages. */ if (PageTransHuge(head)) { + /* + * Non anonymous thp exists only in allocation/free time. We + * can't handle such a case correctly, so let's give it up. + * This should be better than triggering BUG_ON when kernel + * tries to touch the "partially handled" page. + */ + if (!PageAnon(head)) { + pr_err("MCE: %#lx: non anonymous thp\n", + page_to_pfn(page)); + return 0; + } + if (get_page_unless_zero(head)) { if (PageTail(page)) get_page(page); @@ -1134,15 +1146,6 @@ int memory_failure(unsigned long pfn, int trapno, int flags) } if (!PageHuge(p) && PageTransHuge(hpage)) { - if (!PageAnon(hpage)) { - pr_err("MCE: %#lx: non anonymous thp\n", pfn); - if (TestClearPageHWPoison(p)) - atomic_long_sub(nr_pages, &num_poisoned_pages); - put_page(p); - if (p != hpage) - put_page(hpage); - return -EBUSY; - } if (unlikely(split_huge_page(hpage))) { pr_err("MCE: %#lx: thp split failed\n", pfn); if (TestClearPageHWPoison(p)) |