When memory allocation profiling is disabled at runtime or due to an error, shutdown_mem_profiling() is called: slab->obj_exts which previously allocated remains. It won't be cleared by unaccount_slab() because of mem_alloc_profiling_enabled() not true. It's incorrect, slab->obj_exts should always be cleaned up in unaccount_slab() to avoid following error:
[...]BUG: Bad page state in process... .. [...]page dumped because: page still charged to cgroup
Cc: stable@vger.kernel.org Fixes: 21c690a349ba ("mm: introduce slabobj_ext to support slab object extensions") Signed-off-by: Zhenhua Huang quic_zhenhuah@quicinc.com Acked-by: David Rientjes rientjes@google.com Acked-by: Harry Yoo harry.yoo@oracle.com Tested-by: Harry Yoo harry.yoo@oracle.com --- mm/slub.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/mm/slub.c b/mm/slub.c index 566eb8b8282d..a98ce1426076 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2028,8 +2028,8 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, return 0; }
-/* Should be called only if mem_alloc_profiling_enabled() */ -static noinline void free_slab_obj_exts(struct slab *slab) +/* Free only if slab_obj_exts(slab) */ +static inline void free_slab_obj_exts(struct slab *slab) { struct slabobj_ext *obj_exts;
@@ -2601,8 +2601,12 @@ static __always_inline void account_slab(struct slab *slab, int order, static __always_inline void unaccount_slab(struct slab *slab, int order, struct kmem_cache *s) { - if (memcg_kmem_online() || need_slab_obj_ext()) - free_slab_obj_exts(slab); + /* + * The slab object extensions should now be freed regardless of + * whether mem_alloc_profiling_enabled() or not because profiling + * might have been disabled after slab->obj_exts got allocated. + */ + free_slab_obj_exts(slab);
mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), -(PAGE_SIZE << order));