4.14-stable review patch. If anyone has any objections, please let me know.
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From: Shakeel Butt shakeelb@google.com
[ Upstream commit 880cd276dff17ea29e9a8404275c9502b265afa7 ]
All the root caches are linked into slab_root_caches which was introduced by the commit 510ded33e075 ("slab: implement slab_root_caches list") but it missed to add the SLAB's kmem_cache.
While experimenting with opt-in/opt-out kmem accounting, I noticed system crashes due to NULL dereference inside cache_from_memcg_idx() while deferencing kmem_cache.memcg_params.memcg_caches. The upstream clean kernel will not see these crashes but SLAB should be consistent with SLUB which does linked its boot caches (kmem_cache_node and kmem_cache) into slab_root_caches.
Link: http://lkml.kernel.org/r/20180319210020.60289-1-shakeelb@google.com Fixes: 510ded33e075c ("slab: implement slab_root_caches list") Signed-off-by: Shakeel Butt shakeelb@google.com Cc: Tejun Heo tj@kernel.org Cc: Vladimir Davydov vdavydov.dev@gmail.com Cc: Greg Thelen gthelen@google.com Cc: Christoph Lameter cl@linux.com Cc: Pekka Enberg penberg@kernel.org Cc: David Rientjes rientjes@google.com Cc: Joonsoo Kim iamjoonsoo.kim@lge.com Cc: Johannes Weiner hannes@cmpxchg.org Cc: Michal Hocko mhocko@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/slab.c | 1 + 1 file changed, 1 insertion(+)
--- a/mm/slab.c +++ b/mm/slab.c @@ -1283,6 +1283,7 @@ void __init kmem_cache_init(void) nr_node_ids * sizeof(struct kmem_cache_node *), SLAB_HWCACHE_ALIGN); list_add(&kmem_cache->list, &slab_caches); + memcg_link_cache(kmem_cache); slab_state = PARTIAL;
/*