The patch titled
Subject: mm-rmap-stop-store-reordering-issue-on-page-mapping-fix
has been added to the -mm tree. Its filename is
mm-rmap-stop-store-reordering-issue-on-page-mapping-fix.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-rmap-stop-store-reordering-issue-on-page-mapping-fix.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-rmap-stop-store-reordering-issue-on-page-mapping-fix.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Subject: mm-rmap-stop-store-reordering-issue-on-page-mapping-fix
updated for comments change from Johannes
Link: https://lkml.kernel.org/r/e66ef2e5-c74c-6498-e8b3-56c37b9d2d15@xxxxxxxxxxxxxxxxx
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Alexander Duyck <alexander.duyck@xxxxxxxxx>
Cc: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: "Chen, Rong A" <rong.a.chen@xxxxxxxxx>
Cc: Daniel Jordan <daniel.m.jordan@xxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>
Cc: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mika Penttilä <mika.penttila@xxxxxxxxxxxx>
Cc: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Yang Shi <yang.shi@xxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/rmap.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/mm/rmap.c~mm-rmap-stop-store-reordering-issue-on-page-mapping-fix
+++ a/mm/rmap.c
@@ -1055,9 +1055,10 @@ static void __page_set_anon_rmap(struct
anon_vma = anon_vma->root;
/*
- * Prevent page->mapping from pointing to an anon_vma without
- * the PAGE_MAPPING_ANON bit set. This could happen if the
- * compiler stores anon_vma and then adds PAGE_MAPPING_ANON to it.
+ * page_idle does a lockless/optimistic rmap scan on page->mapping.
+ * Make sure the compiler doesn't split the stores of anon_vma and
+ * the PAGE_MAPPING_ANON type identifier, otherwise the rmap code
+ * could mistake the mapping for a struct address_space and crash.
*/
anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;
WRITE_ONCE(page->mapping, (struct address_space *) anon_vma);
_
Patches currently in -mm which might be from alex.shi@xxxxxxxxxxxxxxxxx are
mm-filemap-add-static-for-function-__add_to_page_cache_locked.patch
fs-ntfs-remove-unused-varibles.patch
fs-ntfs-remove-unused-varible-attr_len.patch
mm-memcg-update-page-struct-member-in-comments.patch
mm-thp-move-lru_add_page_tail-func-to-huge_memoryc.patch
mm-thp-use-head-for-head-page-in-lru_add_page_tail.patch
mm-thp-simplify-lru_add_page_tail.patch
mm-thp-narrow-lru-locking.patch
mm-vmscan-remove-unnecessary-lruvec-adding.patch
mm-rmap-stop-store-reordering-issue-on-page-mapping.patch
mm-rmap-stop-store-reordering-issue-on-page-mapping-fix.patch
mm-memcg-add-debug-checking-in-lock_page_memcg.patch
mm-swapc-fold-vm-event-pgrotated-into-pagevec_move_tail_fn.patch
mm-lru-move-lock-into-lru_note_cost.patch
mm-vmscan-remove-lruvec-reget-in-move_pages_to_lru.patch
mm-mlock-remove-lru_lock-on-testclearpagemlocked.patch
mm-mlock-remove-__munlock_isolate_lru_page.patch
mm-lru-introduce-testclearpagelru.patch
mm-compaction-do-page-isolation-first-in-compaction.patch
mm-swapc-serialize-memcg-changes-in-pagevec_lru_move_fn.patch
mm-lru-replace-pgdat-lru_lock-with-lruvec-lock.patch
mm-lru-replace-pgdat-lru_lock-with-lruvec-lock-fix.patch
mm-lru-replace-pgdat-lru_lock-with-lruvec-lock-fix-2.patch
mm-lru-introduce-the-relock_page_lruvec-function-fix.patch
docs-vm-remove-unused-3-items-explanation-for-proc-vmstat.patch
mm-memcg-bail-early-from-swap-accounting-if-memcg-disabled.patch
mm-memcg-warning-on-memcg-after-readahead-page-charged.patch
