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Fix it by adding missing rcu read lock. Fixes: 0a97c01cd20bb ("list_lru: allow explicit memcg and NUMA node selecti= on) Signed-off-by: Muchun Song Acked-by: Shakeel Butt --- mm/list_lru.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/mm/list_lru.c b/mm/list_lru.c index 3fd64736bc458..225da0778a3be 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -85,6 +85,7 @@ list_lru_from_memcg_idx(struct list_lru *lru, int nid, in= t idx) } #endif /* CONFIG_MEMCG_KMEM */ =20 +/* The caller must ensure the memcg lifetime. */ bool list_lru_add(struct list_lru *lru, struct list_head *item, int nid, struct mem_cgroup *memcg) { @@ -109,14 +110,20 @@ EXPORT_SYMBOL_GPL(list_lru_add); =20 bool list_lru_add_obj(struct list_lru *lru, struct list_head *item) { + bool ret; int nid =3D page_to_nid(virt_to_page(item)); - struct mem_cgroup *memcg =3D list_lru_memcg_aware(lru) ? - mem_cgroup_from_slab_obj(item) : NULL; + struct mem_cgroup *memcg; =20 - return list_lru_add(lru, item, nid, memcg); + rcu_read_lock(); + memcg =3D list_lru_memcg_aware(lru) ? mem_cgroup_from_slab_obj(item) : NU= LL; + ret =3D list_lru_add(lru, item, nid, memcg); + rcu_read_unlock(); + + return ret; } EXPORT_SYMBOL_GPL(list_lru_add_obj); =20 +/* The caller must ensure the memcg lifetime. */ bool list_lru_del(struct list_lru *lru, struct list_head *item, int nid, struct mem_cgroup *memcg) { @@ -139,11 +146,16 @@ EXPORT_SYMBOL_GPL(list_lru_del); =20 bool list_lru_del_obj(struct list_lru *lru, struct list_head *item) { + bool ret; int nid =3D page_to_nid(virt_to_page(item)); - struct mem_cgroup *memcg =3D list_lru_memcg_aware(lru) ? - mem_cgroup_from_slab_obj(item) : NULL; + struct mem_cgroup *memcg; =20 - return list_lru_del(lru, item, nid, memcg); + rcu_read_lock(); + memcg =3D list_lru_memcg_aware(lru) ? mem_cgroup_from_slab_obj(item) : NU= LL; + ret =3D list_lru_del(lru, item, nid, memcg); + rcu_read_unlock(); + + return ret; } EXPORT_SYMBOL_GPL(list_lru_del_obj); =20 --=20 2.20.1