diff options
authorzhongjiang <zhongjiang@huawei.com>2019-03-05 15:41:16 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2019-03-05 21:07:13 -0800
commit46612b751c4941c5c0472ddf04027e877ae5990f (patch)
parentMerge tag 'mips_5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux (diff)
mm: hwpoison: fix thp split handing in soft_offline_in_use_page()
When soft_offline_in_use_page() runs on a thp tail page after pmd is split, we trigger the following VM_BUG_ON_PAGE(): Memory failure: 0x3755ff: non anonymous thp __get_any_page: 0x3755ff: unknown zero refcount page type 2fffff80000000 Soft offlining pfn 0x34d805 at process virtual address 0x20fff000 page:ffffea000d360140 count:0 mapcount:0 mapping:0000000000000000 index:0x1 flags: 0x2fffff80000000() raw: 002fffff80000000 ffffea000d360108 ffffea000d360188 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:519! soft_offline_in_use_page() 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(). Naoya had fixed a similar issue in c3901e722b29 ("mm: hwpoison: fix thp split handling in memory_failure()"). But he missed fixing soft offline. Link: http://lkml.kernel.org/r/1551452476-24000-1-git-send-email-zhongjiang@huawei.com Fixes: 61f5d698cc97 ("mm: re-enable THP") Signed-off-by: zhongjiang <zhongjiang@huawei.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Andrea Arcangeli <aarcange@redhat.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 '')
1 files changed, 6 insertions, 8 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 831be5ff5f4d..fc8b51744579 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1825,19 +1825,17 @@ static int soft_offline_in_use_page(struct page *page, int flags)
struct page *hpage = compound_head(page);
if (!PageHuge(page) && PageTransHuge(hpage)) {
- lock_page(hpage);
- if (!PageAnon(hpage) || unlikely(split_huge_page(hpage))) {
- unlock_page(hpage);
- if (!PageAnon(hpage))
+ lock_page(page);
+ if (!PageAnon(page) || unlikely(split_huge_page(page))) {
+ unlock_page(page);
+ if (!PageAnon(page))
pr_info("soft offline: %#lx: non anonymous thp\n", page_to_pfn(page));
pr_info("soft offline: %#lx: thp split failed\n", page_to_pfn(page));
- put_hwpoison_page(hpage);
+ put_hwpoison_page(page);
return -EBUSY;
- unlock_page(hpage);
- get_hwpoison_page(page);
- put_hwpoison_page(hpage);
+ unlock_page(page);