From mboxrd@z Thu Jan 1 00:00:00 1970 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 85AEBC433EF for ; Mon, 28 Mar 2022 15:43:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D8A628D0002; Mon, 28 Mar 2022 11:43:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D39BE8D0001; Mon, 28 Mar 2022 11:43:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BDB9F8D0002; Mon, 28 Mar 2022 11:43:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0136.hostedemail.com [216.40.44.136]) by kanga.kvack.org (Postfix) with ESMTP id AF35B8D0001 for ; Mon, 28 Mar 2022 11:43:45 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 61107A3EEF for ; Mon, 28 Mar 2022 15:43:45 +0000 (UTC) X-FDA: 79294215210.26.77D0377 Received: from mail-yb1-f174.google.com (mail-yb1-f174.google.com [209.85.219.174]) by imf27.hostedemail.com (Postfix) with ESMTP id DD72D40041 for ; Mon, 28 Mar 2022 15:43:44 +0000 (UTC) Received: by mail-yb1-f174.google.com with SMTP id y38so24088746ybi.8 for ; Mon, 28 Mar 2022 08:43:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=JLAMImTBODJ6p1BQ28mgm1zYhXSzYUbNlmQ348cuLdo=; b=GIYTLtunk/7VbdlxJz2L+F+hC5s7K7qDdgMJKyJ4TEI6TpypWEuW3uISWwVhgRmRe0 L6LGJ+vHPyfz+1A/Jo+JJKPbg5dJjRwKEq9Lp9sylO86h5+/W3mpm/Kt8HzHfDRSdZVx E6N8kncLZ6ofsBbax1zxIM7Bnm3vnPrReCA3DePBTNMu5wBShS4HbsbK/ta1/YWSKJZ0 3USyelDXZnfONkjzwyxvkcVd8DqqfxjXKo3qIeOx+eD6o+ITHJrCGnv6KnGg4fKwkaR+ epyweFbyBMws3SiH3/Az2m5+5iAkEu0t+ZWOGGeaKmiWLmc7a1kImsNi87Lj7qDjkfdX +CRw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=JLAMImTBODJ6p1BQ28mgm1zYhXSzYUbNlmQ348cuLdo=; b=cbsQ9vATi/nR5jW8VWDTEoSKe2drca5x57nAzmRe3YnTkFntlkUu5O4l6Sz0UhIURf QVHiLgFXAvPuUyNqkrMEmgPx6EhneLJb/6xyNYR2GVcC0TtqEd9VjqhN1/1jbenOJuk+ PfadKBkAniOP3ElyWmSkWg03qXJUpxKqg0vtJ74TF3N/c536Ztn84KOXmEE8iN3LoGgk uD0lkX3HlCVW1LVI2awKRtSTqiimuSy5i/ny5+naBXuvS4B9mK6zgjK3DZPz0G+IRVSZ Nlerc8L5yHvInXYmZ23FYTn1FYmfXlQ8kAl4M2MNdiALwkiXdHI/zJUByLrch6v+05+X XCcw== X-Gm-Message-State: AOAM531pGuff75gR+md74BZVOFJv3Lp71NP0BI8myjZMlPTuZsZF/H1v Mv5D74RZbX+wijlG+0wJeZPkUnSsL12Ex6vU4M6K1Q== X-Google-Smtp-Source: ABdhPJwmVXEqdR8lQkP19/L8e0cirz16e509iPdj4QWD1qSuTNtPHrKLywy+HWYdoSO5gRqUetj/qXfwkm9pxb46L88= X-Received: by 2002:a05:6902:24f:b0:62d:69d:c9fc with SMTP id k15-20020a056902024f00b0062d069dc9fcmr22422814ybs.87.1648482223855; Mon, 28 Mar 2022 08:43:43 -0700 (PDT) MIME-Version: 1.0 References: <20220328132843.16624-1-songmuchun@bytedance.com> In-Reply-To: <20220328132843.16624-1-songmuchun@bytedance.com> From: Marco Elver Date: Mon, 28 Mar 2022 17:43:07 +0200 Message-ID: Subject: Re: [PATCH v2] mm: kfence: fix objcgs vector allocation To: Muchun Song Cc: glider@google.com, dvyukov@google.com, akpm@linux-foundation.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, duanxiongchun@bytedance.com Content-Type: text/plain; charset="UTF-8" X-Rspam-User: Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=GIYTLtun; spf=pass (imf27.hostedemail.com: domain of elver@google.com designates 209.85.219.174 as permitted sender) smtp.mailfrom=elver@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DD72D40041 X-Stat-Signature: mq5fdop7r9ubdxb57szi3joyaaoaquoa X-HE-Tag: 1648482224-829717 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, 28 Mar 2022 at 15:28, Muchun Song wrote: > > If the kfence object is allocated to be used for objects vector, then > this slot of the pool eventually being occupied permanently since > the vector is never freed. The solutions could be 1) freeing vector > when the kfence object is freed or 2) allocating all vectors statically. > Since the memory consumption of object vectors is low, it is better to > chose 2) to fix the issue and it is also can reduce overhead of vectors > allocating in the future. > > Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB") > Signed-off-by: Muchun Song Reviewed-by: Marco Elver Btw, how did you test this? Thanks, -- Marco > --- > v2: > - Fix compiler error reported by kernel test robot . > > mm/kfence/core.c | 11 ++++++++++- > mm/kfence/kfence.h | 3 +++ > 2 files changed, 13 insertions(+), 1 deletion(-) > > diff --git a/mm/kfence/core.c b/mm/kfence/core.c > index 13128fa13062..d4c7978cd75e 100644 > --- a/mm/kfence/core.c > +++ b/mm/kfence/core.c > @@ -555,6 +555,8 @@ static bool __init kfence_init_pool(void) > * enters __slab_free() slow-path. > */ > for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) { > + struct slab *slab = page_slab(&pages[i]); > + > if (!i || (i % 2)) > continue; > > @@ -562,7 +564,11 @@ static bool __init kfence_init_pool(void) > if (WARN_ON(compound_head(&pages[i]) != &pages[i])) > goto err; > > - __SetPageSlab(&pages[i]); > + __folio_set_slab(slab_folio(slab)); > +#ifdef CONFIG_MEMCG > + slab->memcg_data = (unsigned long)&kfence_metadata[i / 2 - 1].objcg | > + MEMCG_DATA_OBJCGS; > +#endif > } > > /* > @@ -938,6 +944,9 @@ void __kfence_free(void *addr) > { > struct kfence_metadata *meta = addr_to_metadata((unsigned long)addr); > > +#ifdef CONFIG_MEMCG > + KFENCE_WARN_ON(meta->objcg); > +#endif > /* > * If the objects of the cache are SLAB_TYPESAFE_BY_RCU, defer freeing > * the object, as the object page may be recycled for other-typed > diff --git a/mm/kfence/kfence.h b/mm/kfence/kfence.h > index 2a2d5de9d379..9a6c4b1b12a8 100644 > --- a/mm/kfence/kfence.h > +++ b/mm/kfence/kfence.h > @@ -89,6 +89,9 @@ struct kfence_metadata { > struct kfence_track free_track; > /* For updating alloc_covered on frees. */ > u32 alloc_stack_hash; > +#ifdef CONFIG_MEMCG > + struct obj_cgroup *objcg; > +#endif > }; > > extern struct kfence_metadata kfence_metadata[CONFIG_KFENCE_NUM_OBJECTS]; > -- > 2.11.0 >