The patch titled
Subject: mm-restart-if-multiple-traversals-raced-fix
has been added to the -mm mm-unstable branch. Its filename is
mm-restart-if-multiple-traversals-raced-fix.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-restart-if-multiple-traversals-raced-fix.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Hugh Dickins <hughd@xxxxxxxxxx>
Subject: mm-restart-if-multiple-traversals-raced-fix
Date: Fri, 30 Aug 2024 03:04:01 -0700 (PDT)
mem_cgroup_iter() reset memcg to NULL before the goto restart, so that
goto out_unlock does not then return an ungotten memcg, causing oopses on
stale memcg in many places (often in memcg_rstat_updated()).
Link: https://lkml.kernel.org/r/56d42242-37fe-b94f-d3cb-00673f1e5efb@xxxxxxxxxx
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Acked-by: Kinsey Ho <kinseyho@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Michal Koutný <mkoutny@xxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Cc: Tejun Heo <tj@xxxxxxxxxx>
Cc: T.J. Mercier <tjmercier@xxxxxxxxxx>
Cc: Yosry Ahmed <yosryahmed@xxxxxxxxxx>
Cc: Zefan Li <lizefan.x@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 1 +
1 file changed, 1 insertion(+)
--- a/mm/memcontrol.c~mm-restart-if-multiple-traversals-raced-fix
+++ a/mm/memcontrol.c
@@ -1049,6 +1049,7 @@ restart:
if (cmpxchg(&iter->position, pos, memcg) != pos) {
if (css && css != &root->css)
css_put(css);
+ memcg = NULL;
goto restart;
}
_
Patches currently in -mm which might be from hughd@xxxxxxxxxx are
mm-attempt-to-batch-free-swap-entries-for-zap_pte_range-fix-2.patch
mm-shmem-split-large-entry-if-the-swapin-folio-is-not-large-fix.patch
mm-shmem-support-large-folio-swap-out-fix.patch
mm-restart-if-multiple-traversals-raced-fix.patch
mm-shmem-fix-minor-off-by-one-in-shrinkable-calculation.patch
mm-shmem-extend-shmem_unused_huge_shrink-to-all-sizes.patch
