Commit be825078 authored by Zhenhua Huang's avatar Zhenhua Huang Committed by Vlastimil Babka
Browse files

mm, slab: clean up slab->obj_exts always 



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

[andriy.shevchenko@linux.intel.com: fold need_slab_obj_ext() into its only user]
Fixes: 21c690a3 ("mm: introduce slabobj_ext to support slab object extensions")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarZhenhua Huang <quic_zhenhuah@quicinc.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Acked-by: default avatarHarry Yoo <harry.yoo@oracle.com>
Tested-by: default avatarHarry Yoo <harry.yoo@oracle.com>
Acked-by: default avatarSuren Baghdasaryan <surenb@google.com>
Link: https://patch.msgid.link/20250421075232.2165527-1-quic_zhenhuah@quicinc.com


Signed-off-by: default avatarVlastimil Babka <vbabka@suse.cz>
parent d2f5819b

mm/slub.c

+8 −22
Original line number Diff line number Diff line
@@ -2028,8 +2028,7 @@ 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)

static inline void free_slab_obj_exts(struct slab *slab)

{

	struct slabobj_ext *obj_exts;
@@ -2049,18 +2048,6 @@ static noinline void free_slab_obj_exts(struct slab *slab) 
	slab->obj_exts = 0;

}



static inline bool need_slab_obj_ext(void)

{

	if (mem_alloc_profiling_enabled())

		return true;



	/*

	 * CONFIG_MEMCG creates vector of obj_cgroup objects conditionally

	 * inside memcg_slab_post_alloc_hook. No other users for now.

	 */

	return false;

}



#else /* CONFIG_SLAB_OBJ_EXT */



static inline void init_slab_obj_exts(struct slab *slab)
@@ -2077,11 +2064,6 @@ static inline void free_slab_obj_exts(struct slab *slab) 
{

}



static inline bool need_slab_obj_ext(void)

{

	return false;

}



#endif /* CONFIG_SLAB_OBJ_EXT */



#ifdef CONFIG_MEM_ALLOC_PROFILING
@@ -2129,7 +2111,7 @@ __alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags) 
static inline void

alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags)

{

	if (need_slab_obj_ext())

	if (mem_alloc_profiling_enabled())

		__alloc_tagging_slab_alloc_hook(s, object, flags);

}
@@ -2601,7 +2583,11 @@ 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())

	/*

	 * 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),