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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham 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 E56DCC47404 for ; Thu, 10 Oct 2019 00:27:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id B034D21848 for ; Thu, 10 Oct 2019 00:27:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B034D21848 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ah.jp.nec.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 235466B0006; Wed, 9 Oct 2019 20:27:29 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 1E5F56B0007; Wed, 9 Oct 2019 20:27:29 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0FCD58E0003; Wed, 9 Oct 2019 20:27:29 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0148.hostedemail.com [216.40.44.148]) by kanga.kvack.org (Postfix) with ESMTP id E587E6B0006 for ; Wed, 9 Oct 2019 20:27:28 -0400 (EDT) Received: from smtpin20.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id 94EDFD38 for ; Thu, 10 Oct 2019 00:27:28 +0000 (UTC) X-FDA: 76025986176.20.goat18_23fa7aa6d7425 X-HE-Tag: goat18_23fa7aa6d7425 X-Filterd-Recvd-Size: 3907 Received: from tyo161.gate.nec.co.jp (tyo161.gate.nec.co.jp [114.179.232.161]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Thu, 10 Oct 2019 00:27:26 +0000 (UTC) Received: from mailgate02.nec.co.jp ([114.179.233.122]) by tyo161.gate.nec.co.jp (8.15.1/8.15.1) with ESMTPS id x9A0RKQN018137 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Thu, 10 Oct 2019 09:27:20 +0900 Received: from mailsv02.nec.co.jp (mailgate-v.nec.co.jp [10.204.236.94]) by mailgate02.nec.co.jp (8.15.1/8.15.1) with ESMTP id x9A0RK5D006401; Thu, 10 Oct 2019 09:27:20 +0900 Received: from mail02.kamome.nec.co.jp (mail02.kamome.nec.co.jp [10.25.43.5]) by mailsv02.nec.co.jp (8.15.1/8.15.1) with ESMTP id x9A0R49V023354; Thu, 10 Oct 2019 09:27:20 +0900 Received: from bpxc99gp.gisp.nec.co.jp ([10.38.151.148] [10.38.151.148]) by mail01b.kamome.nec.co.jp with ESMTP id BT-MMP-9297955; Thu, 10 Oct 2019 09:26:20 +0900 Received: from BPXM23GP.gisp.nec.co.jp ([10.38.151.215]) by BPXC20GP.gisp.nec.co.jp ([10.38.151.148]) with mapi id 14.03.0439.000; Thu, 10 Oct 2019 09:26:19 +0900 From: Naoya Horiguchi To: David Hildenbrand CC: "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Andrew Morton , Michal Hocko Subject: Re: [PATCH v2 2/2] mm/memory-failure.c: Don't access uninitialized memmaps in memory_failure() Thread-Topic: [PATCH v2 2/2] mm/memory-failure.c: Don't access uninitialized memmaps in memory_failure() Thread-Index: AQHVfq1QC/9/3IlYuEK91tWnhgAEnKdSbnGA Date: Thu, 10 Oct 2019 00:26:19 +0000 Message-ID: <20191010002619.GB3585@hori.linux.bs1.fc.nec.co.jp> References: <20191009142435.3975-1-david@redhat.com> <20191009142435.3975-3-david@redhat.com> In-Reply-To: <20191009142435.3975-3-david@redhat.com> Accept-Language: en-US, ja-JP Content-Language: ja-JP X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.34.125.96] Content-Type: text/plain; charset="iso-2022-jp" Content-ID: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-TM-AS-MML: disable 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 Wed, Oct 09, 2019 at 04:24:35PM +0200, David Hildenbrand wrote: > We should check for pfn_to_online_page() to not access uninitialized > memmaps. Reshuffle the code so we don't have to duplicate the error > message. >=20 > Cc: Naoya Horiguchi > Cc: Andrew Morton > Cc: Michal Hocko > Signed-off-by: David Hildenbrand > --- > mm/memory-failure.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) >=20 > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 7ef849da8278..e866e6e5660b 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1253,17 +1253,19 @@ int memory_failure(unsigned long pfn, int flags) > if (!sysctl_memory_failure_recovery) > panic("Memory failure on page %lx", pfn); > =20 > - if (!pfn_valid(pfn)) { > + p =3D pfn_to_online_page(pfn); > + if (!p) { > + if (pfn_valid(pfn)) { > + pgmap =3D get_dev_pagemap(pfn, NULL); > + if (pgmap) > + return memory_failure_dev_pagemap(pfn, flags, > + pgmap); > + } > pr_err("Memory failure: %#lx: memory outside kernel control\n", > pfn); > return -ENXIO; > } > =20 > - pgmap =3D get_dev_pagemap(pfn, NULL); > - if (pgmap) > - return memory_failure_dev_pagemap(pfn, flags, pgmap); > - > - p =3D pfn_to_page(pfn); This change seems to assume that memory_failure_dev_pagemap() is never called for online pages. Is it an intended behavior? Or the concept "online pages" is not applicable to zone device pages? Thanks, Naoya Horiguchi=