This is a note to let you know that I've just added the patch titled
mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-hwpoison-call-shake_page-after-try_to_unmap-for-mlocked-page.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Thu Mar 22 14:40:24 CET 2018
From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Date: Wed, 3 May 2017 14:56:22 -0700
Subject: mm: hwpoison: call shake_page() after try_to_unmap() for mlocked page
From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
[ 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@xxxxxxxxxxxxx
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Cc: Xiaolong Ye <xiaolong.ye@xxxxxxxxx>
Cc: Chen Gong <gong.chen@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -921,6 +921,7 @@ static int hwpoison_user_mappings(struct
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
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
Patches currently in stable-queue which might be from n-horiguchi@xxxxxxxxxxxxx are
queue-4.9/mm-hwpoison-call-shake_page-after-try_to_unmap-for-mlocked-page.patch