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 X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C5ED4C56202 for ; Wed, 25 Nov 2020 22:27:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D45F12075A for ; Wed, 25 Nov 2020 22:27:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=canb.auug.org.au header.i=@canb.auug.org.au header.b="g1pirN09" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D45F12075A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=canb.auug.org.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 048F36B006E; Wed, 25 Nov 2020 17:27:17 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F153C6B0070; Wed, 25 Nov 2020 17:27:16 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E29D46B0071; Wed, 25 Nov 2020 17:27:16 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0235.hostedemail.com [216.40.44.235]) by kanga.kvack.org (Postfix) with ESMTP id CA8BF6B006E for ; Wed, 25 Nov 2020 17:27:16 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 98FFD8249980 for ; Wed, 25 Nov 2020 22:27:16 +0000 (UTC) X-FDA: 77524377672.17.shake41_0a0bd1e2737a Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id 7EC6F180D0184 for ; Wed, 25 Nov 2020 22:27:16 +0000 (UTC) X-HE-Tag: shake41_0a0bd1e2737a X-Filterd-Recvd-Size: 5140 Received: from ozlabs.org (bilbo.ozlabs.org [203.11.71.1]) by imf26.hostedemail.com (Postfix) with ESMTP for ; Wed, 25 Nov 2020 22:27:14 +0000 (UTC) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange ECDHE (P-256) server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4ChFqw0tYCz9s1l; Thu, 26 Nov 2020 09:27:07 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=canb.auug.org.au; s=201702; t=1606343231; bh=GUGR5Jb8Ps+88ArLoeZmH1zDG+KVi5x+k26h13IPYMk=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=g1pirN09gNiwxEEWXFWtM6XXCfRSEZodmwmj2GpiJ+myjXn/YMmB9k3cyILlamCLi bmY9C83SDEGFCl+Pb272tI+frmHayU6vskvaqloRwr5MimnqTf36bNs+AmtPcQFG22 ZQr1VzNH8Rl5la+yj9rlqK202fH8M8aWhiCpSmL7my2bUDfz/c2ae5b2UIVpE+m9Ol CI5V165pB8HM3pDnT9lWZ2RKTNsYXJ6e4ci4GDlpKRF0Kys8GxCmCYFvsgOaB10HLF YXCTXDXlaYaPGcV3uBfMMR7KWH1dIR4GXium2UYixGcCoyWaJLeVkFD4a+BI7kKkkt TuLGVImotOImw== Date: Thu, 26 Nov 2020 09:27:06 +1100 From: Stephen Rothwell To: Alex Shi Cc: Lorenzo Stoakes , Johannes Weiner , Hui Su , Shakeel Butt , Roman Gushchin , syzbot , Linux Kernel Mailing List , linux-mm , Linux-Next Mailing List , syzkaller-bugs , Andrew Morton Subject: Re: [PATCH] mm/memcg: warn on missing memcg on mem_cgroup_page_lruvec() Message-ID: <20201126092706.1e06aa08@canb.auug.org.au> In-Reply-To: <0918d6f5-8459-7b5e-82a3-6c9792d17433@linux.alibaba.com> References: <00000000000054aea005b4d59e71@google.com> <20201125112202.387009-1-lstoakes@gmail.com> <0918d6f5-8459-7b5e-82a3-6c9792d17433@linux.alibaba.com> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="Sig_/S1QJfwUbyxzDCF4y6WxxMQm"; protocol="application/pgp-signature"; micalg=pgp-sha256 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: --Sig_/S1QJfwUbyxzDCF4y6WxxMQm Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Hi all, On Wed, 25 Nov 2020 20:15:11 +0800 Alex Shi wr= ote: > > Acked-by: Alex Shi >=20 >=20 > =E5=9C=A8 2020/11/25 =E4=B8=8B=E5=8D=887:22, Lorenzo Stoakes =E5=86=99=E9= =81=93: > > Move memcg check to mem_cgroup_page_lruvec() as there are callers which > > may invoke this with !memcg in mem_cgroup_lruvec(), whereas they should > > not in mem_cgroup_page_lruvec(). > >=20 > > We expect that we have always charged a page to the memcg before > > mem_cgroup_page_lruvec() is invoked, so add a warning to assert that th= is > > is the case. > >=20 > > Signed-off-by: Lorenzo Stoakes > > Reported-by: syzbot+ce635500093181f39c1c@syzkaller.appspotmail.com > > --- > > include/linux/memcontrol.h | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > >=20 > > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > > index 87ed56dc75f9..3e6a1df3bdb9 100644 > > --- a/include/linux/memcontrol.h > > +++ b/include/linux/memcontrol.h > > @@ -618,7 +618,6 @@ static inline struct lruvec *mem_cgroup_lruvec(stru= ct mem_cgroup *memcg, > > goto out; > > } > > =20 > > - VM_WARN_ON_ONCE(!memcg); > > if (!memcg) > > memcg =3D root_mem_cgroup; > > =20 > > @@ -645,7 +644,10 @@ static inline struct lruvec *mem_cgroup_lruvec(str= uct mem_cgroup *memcg, > > static inline struct lruvec *mem_cgroup_page_lruvec(struct page *page, > > struct pglist_data *pgdat) > > { > > - return mem_cgroup_lruvec(page_memcg(page), pgdat); > > + struct mem_cgroup *memcg =3D page_memcg(page); > > + > > + VM_WARN_ON_ONCE_PAGE(!memcg, page); > > + return mem_cgroup_lruvec(memcg, pgdat); > > } > > =20 > > static inline bool lruvec_holds_page_lru_lock(struct page *page, > > =20 I have added that patch to the akpm tree in linux-next today as a fix for "mm/memcg: add missed warning in mem_cgroup_lruvec". Andrew: the original patch is here: https://lore.kernel.org/lkml/20201125112202.387009-1-lstoakes@gmail.com/ --=20 Cheers, Stephen Rothwell --Sig_/S1QJfwUbyxzDCF4y6WxxMQm Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEENIC96giZ81tWdLgKAVBC80lX0GwFAl++2joACgkQAVBC80lX 0GwWMQf/Q2aM02yswn7APiVTNxVOArueh6QNTpAd64O6C4UYV/xVXE610PTdiN4B 78pvnV2eMWZNH/UAPxP8/DeVS2ScDF5CGdlHEbWxBmQNyzpsIJzodLvZBJPiC5xp DItXhuE6su028Mpdm+SElzk6OOhWwhVP+2ktPVKeUFJSfmxJcjgf3uO7y370Ywit Zs6BKxGMLzrqfGGfR4p7s0yGbUpOydXP8gFkp1gg8KcgvxjtFzm6eIF8KWBp5MxM Fr2R5Y+2mIhu8fW1NTuOwPgIf/+FTm5g3YZI1b4vqCEyzcn6Xs2nuWlaRZqUHq4B auVlC1NCh5E/S6bB30xlDxiKSgNK/A== =Ltrr -----END PGP SIGNATURE----- --Sig_/S1QJfwUbyxzDCF4y6WxxMQm--