From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6D69F42CB13; Mon, 20 Jul 2026 14:16:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784557011; cv=none; b=Qu9r1F7A0sPCioOjbYcmV+ks/KWbKYzYAHaW+DdPGzf7Nz2eR/4057rnAjI4KBwbt4sAinPjXCC98/SORq/fUg1b8kElX7o2DWk0TexZO0RHT2+LP/o/8ZVPFzkkYlkk5eGprUFFBTeW3mmdlG1ITviOleDXVCz2/AzO8nJ+Whk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784557011; c=relaxed/simple; bh=qRhbsPVpLn1S0jVnMzHPeZNIgXEVXf6DA1Hwaw/x/SE=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=glPOY0X2KpCAGF7C3BHx+/ytsD4MV1D0J9/K9IMf+B+U8dRBZKdL1iZxR37CSEFI6vvDnsqIngkq/BQwhStBRgJeTggP6Rf6rHjnde2Cb1gLfxjwm9f0rwNR9UW5mIwr3Ww7Ve3PuZl+AVM22FWF5MXffShHQu36GbgvmHffFLA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FeexIb05; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FeexIb05" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9CC431F000E9; Mon, 20 Jul 2026 14:16:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784557010; bh=6r95VsQz7/bTPUaUrteE7bqXPatxg+Tzf2bzkDOfpus=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=FeexIb05eHtmuOUiBfDtAWxk3PrPlHYamFu45sXhoPfPvLfZHK3B+P/3oLwfibj3F 2KM/AArbZ55tU1uwIesTVdWN2BsJV9KT2SqwUU2I3pTlWgAoC3yfkkTt3FnVETIfH6 8ETfJb47yFBxAdkpg3KmKOmKFV8jjB0KLX/geS+LghDHRmuPHWUcEJp8ntR8H8Xu5+ RxQ6aJZhttrV2b8/IcKp0pHMgDmq+GK/aKseQVharGFoYKdP7ntubaYo0UGSh8QE8d 6+M7ZI7lwH/Aq3mupNhevs/wzMenUWn5Xdbs3woHw5ZgEcr4G77yvJbbClkazgqFWL +R692rxxO6N4Q== From: "Vlastimil Babka (SUSE)" Date: Mon, 20 Jul 2026 16:16:21 +0200 Subject: [PATCH v2 07/13] mm/slab: abstract slabobj_ext.ref access Precedence: bulk X-Mailing-List: cgroups@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260720-b4-objext_split-v2-7-2fa7c6f60dbe@kernel.org> References: <20260720-b4-objext_split-v2-0-2fa7c6f60dbe@kernel.org> In-Reply-To: <20260720-b4-objext_split-v2-0-2fa7c6f60dbe@kernel.org> To: Harry Yoo , Suren Baghdasaryan Cc: Hao Li , Shakeel Butt , Alexander Potapenko , Marco Elver , Andrew Morton , Christoph Lameter , David Rientjes , Roman Gushchin , linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, "Vlastimil Babka (SUSE)" X-Mailer: b4 0.15.2 In preparation for changes to the structure, abstract access to the ref field with a slab_obj_ext_codetag_ref() function. Rename the field to _ctref to make an unexpected direct access a compile error. No functional change intended. Reviewed-by: Suren Baghdasaryan Signed-off-by: Vlastimil Babka (SUSE) --- mm/slab.h | 10 +++++++++- mm/slub.c | 42 +++++++++++++++++++++++++++++------------- 2 files changed, 38 insertions(+), 14 deletions(-) diff --git a/mm/slab.h b/mm/slab.h index 1d1771f97aca..62d6366d7d79 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -558,7 +558,7 @@ struct slabobj_ext { struct obj_cgroup *_objcg; #endif #ifdef CONFIG_MEM_ALLOC_PROFILING - union codetag_ref ref; + union codetag_ref _ctref; #endif } __aligned(8); @@ -675,6 +675,14 @@ static inline void slab_obj_ext_set_objcg(struct slabobj_ext *obj_ext, } #endif +#ifdef CONFIG_MEM_ALLOC_PROFILING +static inline union codetag_ref * +slab_obj_ext_codetag_ref(struct slab *slab, struct slabobj_ext *obj_ext) +{ + return &obj_ext->_ctref; +} +#endif + int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, gfp_t gfp, unsigned int alloc_flags); diff --git a/mm/slub.c b/mm/slub.c index f2ffadde879d..cf999cbe75d1 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -2071,23 +2071,25 @@ static inline void mark_obj_codetag_empty(const void *obj) slab_exts = slab_obj_exts(obj_slab); if (slab_exts) { struct slabobj_ext *ext; + union codetag_ref *ref; get_slab_obj_exts(slab_exts); ext = slab_obj_ext(obj_slab->slab_cache, obj_slab, slab_exts, obj); + ref = slab_obj_ext_codetag_ref(obj_slab, ext); if (is_kfence_address(obj)) { put_slab_obj_exts(slab_exts); return; } - if (unlikely(is_codetag_empty(&ext->ref))) { + if (unlikely(is_codetag_empty(ref))) { put_slab_obj_exts(slab_exts); return; } /* codetag should be NULL here */ - WARN_ON(ext->ref.ct); - set_codetag_empty(&ext->ref); + WARN_ON(ref->ct); + set_codetag_empty(ref); put_slab_obj_exts(slab_exts); } } @@ -2097,8 +2099,8 @@ static inline bool mark_failed_objexts_alloc(struct slab *slab) return cmpxchg(&slab->obj_exts, 0, OBJEXTS_ALLOC_FAIL) == 0; } -static inline void handle_failed_objexts_alloc(unsigned long obj_exts, - struct slabobj_ext *vec, unsigned int objects) +static inline void handle_failed_objexts_alloc(struct slab *slab, + unsigned long obj_exts, struct slabobj_ext *vec) { if (!mem_alloc_profiling_enabled()) return; @@ -2108,9 +2110,14 @@ static inline void handle_failed_objexts_alloc(unsigned long obj_exts, * objects with no tag reference. Mark all references in this * vector as empty to avoid warnings later on. */ - if (obj_exts == OBJEXTS_ALLOC_FAIL) { - for (unsigned int i = 0; i < objects; i++) - set_codetag_empty(&vec[i].ref); + if (obj_exts != OBJEXTS_ALLOC_FAIL) + return; + + for (unsigned int i = 0; i < slab->objects; i++) { + union codetag_ref *ref = slab_obj_ext_codetag_ref(slab, vec); + + set_codetag_empty(ref); + vec++; } } @@ -2118,8 +2125,8 @@ static inline void handle_failed_objexts_alloc(unsigned long obj_exts, static inline void mark_obj_codetag_empty(const void *obj) {} static inline bool mark_failed_objexts_alloc(struct slab *slab) { return false; } -static inline void handle_failed_objexts_alloc(unsigned long obj_exts, - struct slabobj_ext *vec, unsigned int objects) {} +static inline void handle_failed_objexts_alloc(struct slab *slab, + unsigned long obj_exts, struct slabobj_ext *vec) {} #endif /* CONFIG_MEM_ALLOC_PROFILING_DEBUG */ @@ -2187,7 +2194,7 @@ int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, #endif retry: old_exts = READ_ONCE(slab->obj_exts); - handle_failed_objexts_alloc(old_exts, vec, slab->objects); + handle_failed_objexts_alloc(slab, old_exts, vec); if (new_slab) { /* @@ -2367,9 +2374,15 @@ __alloc_tagging_slab_alloc_hook(struct kmem_cache *s, void *object, gfp_t flags, * check should be added before alloc_tag_add(). */ if (obj_exts) { + union codetag_ref *ref; + get_slab_obj_exts(obj_exts); + obj_ext = slab_obj_ext(s, slab, obj_exts, object); - alloc_tag_add(&obj_ext->ref, current->alloc_tag, s->size); + ref = slab_obj_ext_codetag_ref(slab, obj_ext); + + alloc_tag_add(ref, current->alloc_tag, s->size); + put_slab_obj_exts(obj_exts); } else { alloc_tag_set_inaccurate(current->alloc_tag); @@ -2401,10 +2414,13 @@ __alloc_tagging_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p get_slab_obj_exts(obj_exts); for (int i = 0; i < objects; i++) { + struct slabobj_ext *ext; + if (is_kfence_address(p[i])) continue; - alloc_tag_sub(&slab_obj_ext(s, slab, obj_exts, p[i])->ref, s->size); + ext = slab_obj_ext(s, slab, obj_exts, p[i]); + alloc_tag_sub(slab_obj_ext_codetag_ref(slab, ext), s->size); } put_slab_obj_exts(obj_exts); } -- 2.55.0