From: Naoya Horiguchi Date: Wed, 3 May 2017 21:56:22 +0000 (-0700) Subject: mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page X-Git-Tag: v4.9.90~49 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0b42ce075d8ed11259b36cdbed99bbab8f1f69f1;p=platform%2Fkernel%2Flinux-amlogic.git mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page [ Upstream commit 286c469a988fbaf68e3a97ddf1e6c245c1446968 ] Memory error handler calls try_to_unmap() for error pages in various states. If the error page is a mlocked page, error handling could fail with "still referenced by 1 users" message. This is because the page is linked to and stays in lru cache after the following call chain. try_to_unmap_one page_remove_rmap clear_page_mlock putback_lru_page lru_cache_add memory_failure() calls shake_page() to hanlde the similar issue, but current code doesn't cover because shake_page() is called only before try_to_unmap(). So this patches adds shake_page(). Fixes: 23a003bfd23ea9ea0b7756b920e51f64b284b468 ("mm/madvise: pass return code of memory_failure() to userspace") Link: http://lkml.kernel.org/r/20170417055948.GM31394@yexl-desktop Link: http://lkml.kernel.org/r/1493197841-23986-3-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Naoya Horiguchi Reported-by: kernel test robot Cc: Xiaolong Ye Cc: Chen Gong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 5aa71a8..851efb0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -921,6 +921,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, int ret; int kill = 1, forcekill; struct page *hpage = *hpagep; + bool mlocked = PageMlocked(hpage); /* * Here we are interested only in user-mapped pages, so skip any @@ -985,6 +986,13 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, pfn, page_mapcount(hpage)); /* + * try_to_unmap() might put mlocked page in lru cache, so call + * shake_page() again to ensure that it's flushed. + */ + if (mlocked) + shake_page(hpage, 0); + + /* * Now that the dirty bit has been propagated to the * struct page and all unmaps done we can decide if * killing is needed or not. Only kill when the page