From nobody Wed Apr 8 08:07:21 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B7CCC4332F for ; Sat, 12 Nov 2022 10:58:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234878AbiKLK6f (ORCPT ); Sat, 12 Nov 2022 05:58:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57210 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234540AbiKLK60 (ORCPT ); Sat, 12 Nov 2022 05:58:26 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3370BB867 for ; Sat, 12 Nov 2022 02:58:22 -0800 (PST) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.53]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4N8XWw5pTxzqSLf; Sat, 12 Nov 2022 18:54:36 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Sat, 12 Nov 2022 18:58:20 +0800 Received: from huawei.com (10.175.113.32) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Sat, 12 Nov 2022 18:58:19 +0800 From: Liu Shixin To: Christoph Lameter , Pekka Enberg , "David Rientjes" , Joonsoo Kim , "Andrew Morton" , Vlastimil Babka , "Roman Gushchin" , Hyeonggon Yoo <42.hyeyoo@gmail.com> CC: , , Liu Shixin Subject: [PATCH v4 2/3] mm/slub: Refactor __kmem_cache_create() Date: Sat, 12 Nov 2022 19:46:01 +0800 Message-ID: <20221112114602.1268989-3-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221112114602.1268989-1-liushixin2@huawei.com> References: <20221112114602.1268989-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Separate sysfs_slab_add() and debugfs_slab_add() from __kmem_cache_create() can help to fix a memory leak about kobject. After this patch, we can fix the memory leak naturally by calling kobject_put() to free kobject and associated kmem_cache when sysfs_slab_add() failed. Besides, after that, we can easy to provide sysfs and debugfs support for other allocators too. Signed-off-by: Liu Shixin --- include/linux/slub_def.h | 11 ++++++++++ mm/slab_common.c | 12 +++++++++++ mm/slub.c | 44 +++++++--------------------------------- 3 files changed, 30 insertions(+), 37 deletions(-) diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h index f9c68a9dac04..26d56c4c74d1 100644 --- a/include/linux/slub_def.h +++ b/include/linux/slub_def.h @@ -144,9 +144,14 @@ struct kmem_cache { =20 #ifdef CONFIG_SYSFS #define SLAB_SUPPORTS_SYSFS +int sysfs_slab_add(struct kmem_cache *); void sysfs_slab_unlink(struct kmem_cache *); void sysfs_slab_release(struct kmem_cache *); #else +static inline int sysfs_slab_add(struct kmem_cache *s) +{ + return 0; +} static inline void sysfs_slab_unlink(struct kmem_cache *s) { } @@ -155,6 +160,12 @@ static inline void sysfs_slab_release(struct kmem_cach= e *s) } #endif =20 +#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG) +void debugfs_slab_add(struct kmem_cache *); +#else +static inline void debugfs_slab_add(struct kmem_cache *s) { } +#endif + void *fixup_red_left(struct kmem_cache *s, void *p); =20 static inline void *nearest_obj(struct kmem_cache *cache, const struct sla= b *slab, diff --git a/mm/slab_common.c b/mm/slab_common.c index e5f430a17d95..55e2cf064dfe 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -234,6 +234,18 @@ static struct kmem_cache *create_cache(const char *nam= e, if (err) goto out_free_name; =20 +#ifdef SLAB_SUPPORTS_SYSFS + /* Mutex is not taken during early boot */ + if (slab_state >=3D FULL) { + err =3D sysfs_slab_add(s); + if (err) { + slab_kmem_cache_release(s); + return ERR_PTR(err); + } + debugfs_slab_add(s); + } +#endif + s->refcount =3D 1; list_add(&s->list, &slab_caches); return s; diff --git a/mm/slub.c b/mm/slub.c index ba94eb6fda78..a1ad759753ce 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -299,20 +299,12 @@ struct track { enum track_item { TRACK_ALLOC, TRACK_FREE }; =20 #ifdef CONFIG_SYSFS -static int sysfs_slab_add(struct kmem_cache *); static int sysfs_slab_alias(struct kmem_cache *, const char *); #else -static inline int sysfs_slab_add(struct kmem_cache *s) { return 0; } static inline int sysfs_slab_alias(struct kmem_cache *s, const char *p) { return 0; } #endif =20 -#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_SLUB_DEBUG) -static void debugfs_slab_add(struct kmem_cache *); -#else -static inline void debugfs_slab_add(struct kmem_cache *s) { } -#endif - static inline void stat(const struct kmem_cache *s, enum stat_item si) { #ifdef CONFIG_SLUB_STATS @@ -4297,7 +4289,7 @@ static int calculate_sizes(struct kmem_cache *s) return !!oo_objects(s->oo); } =20 -static int kmem_cache_open(struct kmem_cache *s, slab_flags_t flags) +int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags) { s->flags =3D kmem_cache_flags(s->size, flags, s->name); #ifdef CONFIG_SLAB_FREELIST_HARDENED @@ -4900,30 +4892,6 @@ __kmem_cache_alias(const char *name, unsigned int si= ze, unsigned int align, return s; } =20 -int __kmem_cache_create(struct kmem_cache *s, slab_flags_t flags) -{ - int err; - - err =3D kmem_cache_open(s, flags); - if (err) - return err; - - /* Mutex is not taken during early boot */ - if (slab_state <=3D UP) - return 0; - - err =3D sysfs_slab_add(s); - if (err) { - __kmem_cache_release(s); - return err; - } - - if (s->flags & SLAB_STORE_USER) - debugfs_slab_add(s); - - return 0; -} - #ifdef CONFIG_SYSFS static int count_inuse(struct slab *slab) { @@ -5913,7 +5881,7 @@ static char *create_unique_id(struct kmem_cache *s) return name; } =20 -static int sysfs_slab_add(struct kmem_cache *s) +int sysfs_slab_add(struct kmem_cache *s) { int err; const char *name; @@ -6236,10 +6204,13 @@ static const struct file_operations slab_debugfs_fo= ps =3D { .release =3D slab_debug_trace_release, }; =20 -static void debugfs_slab_add(struct kmem_cache *s) +void debugfs_slab_add(struct kmem_cache *s) { struct dentry *slab_cache_dir; =20 + if (!(s->flags & SLAB_STORE_USER)) + return; + if (unlikely(!slab_debugfs_root)) return; =20 @@ -6264,8 +6235,7 @@ static int __init slab_debugfs_init(void) slab_debugfs_root =3D debugfs_create_dir("slab", NULL); =20 list_for_each_entry(s, &slab_caches, list) - if (s->flags & SLAB_STORE_USER) - debugfs_slab_add(s); + debugfs_slab_add(s); =20 return 0; =20 --=20 2.25.1