| Message ID | 20230708085744.3599311-9-linmiaohe@huawei.com |
|---|---|
| State | New |
| Headers |
Return-Path: <linux-kernel-owner@vger.kernel.org>
Delivered-To: ouuuleilei@gmail.com
Received: by 2002:a59:9f45:0:b0:3ea:f831:8777 with SMTP id v5csp3828979vqx;
Sat, 8 Jul 2023 03:16:18 -0700 (PDT)
X-Google-Smtp-Source:
APBJJlF7rQ+EFiid5WFTy2eZHR6XUq0wEI7L6lYZ4H4JhiAe2lEcHM9V/ZoFj+pIPMDSwSj20flZ
X-Received: by 2002:a50:e606:0:b0:51e:d96:15e4 with SMTP id
y6-20020a50e606000000b0051e0d9615e4mr6042913edm.19.1688811378249;
Sat, 08 Jul 2023 03:16:18 -0700 (PDT)
ARC-Seal: i=1; a=rsa-sha256; t=1688811378; cv=none;
d=google.com; s=arc-20160816;
b=JypQ6Stad4o/wDWzv7lwxLiYRXACx8d30JKU1Q5o4rjW8AVof4+8uDzVUnr8syWmwx
znDIcsUQbr9ZUFsx3KGtX32n6u2P9iozbdu3iBGXQbIK+LsHDaKyaQQb5ApY8yS3hMME
ulcOtW6BdTNJkQrsllMA8EJfCP2hk7EENt3kj1DK3ke8sqar3fgxlpPdOv4knF+JuogU
+O2xF+S3iYk3A24rcVgp8TOZpbtVG4MtSFaYGOqshugxo09nW+yPJFG/q7qbEq/yv/fv
uqxrOwtuAIIXdUeESU9Fk1QV1E1+1zgxAK4Ym8lOl/5N/uuYei41jWoWwEfEmbQG8ZHY
Mehw==
ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com;
s=arc-20160816;
h=list-id:precedence:content-transfer-encoding:mime-version
:references:in-reply-to:message-id:date:subject:cc:to:from;
bh=Qv7v0MakVggbJJx0U+5+eQj6+hfyeFZeeQvIWRA1lsE=;
fh=4o7DIXI/66oHEW09L3854GeQKXh9nrvBy5ZxENMFBvA=;
b=FfpzLWFgIqiLgQIFDnBfvQ8js7/nXVj4NyouH6PIQ2bDGkHz4JpH0BdkUNIAvpxrwI
OWn/sjVtwHOl0IZx0HEkOZw64yB8a6FOZCvoHghbfHaD0iISh5uiZoVzZRI/IzAHdjBG
0hJ9x/zvMNLu9+nbzB3TAq9xjuqJF4ra6y/pzm2EeMUrNY21N28HjMeYRf2rfD83mt8R
qG49YWVCzQSmE/WYhX5RRDx4Fy51osiv1UNSzQqAF9A0GIYEKey3XBsNO+yOOhbNUbyQ
b5j57UOw7OtoEn0+yuqLnQ9D02BxKL3f/TT+JUE2Mhc4CopY8/WOcCkW+cM8RKdkFEAh
ImQQ==
ARC-Authentication-Results: i=1; mx.google.com;
spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org
designates 2620:137:e000::1:20 as permitted sender)
smtp.mailfrom=linux-kernel-owner@vger.kernel.org;
dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com
Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20])
by mx.google.com with ESMTP id
d4-20020a50fb04000000b0051e26731172si3190490edq.672.2023.07.08.03.15.43;
Sat, 08 Jul 2023 03:16:18 -0700 (PDT)
Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org
designates 2620:137:e000::1:20 as permitted sender)
client-ip=2620:137:e000::1:20;
Authentication-Results: mx.google.com;
spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org
designates 2620:137:e000::1:20 as permitted sender)
smtp.mailfrom=linux-kernel-owner@vger.kernel.org;
dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
id S230122AbjGHI5h (ORCPT <rfc822;hadasmailinglist@gmail.com>
+ 99 others); Sat, 8 Jul 2023 04:57:37 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40766 "EHLO
lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
with ESMTP id S229874AbjGHI5f (ORCPT
<rfc822;linux-kernel@vger.kernel.org>);
Sat, 8 Jul 2023 04:57:35 -0400
Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255])
by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E88F22105
for <linux-kernel@vger.kernel.org>;
Sat, 8 Jul 2023 01:57:33 -0700 (PDT)
Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57])
by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4QykfQ5qvgz1FDgw;
Sat, 8 Jul 2023 16:57:02 +0800 (CST)
Received: from huawei.com (10.174.151.185) by canpemm500002.china.huawei.com
(7.192.104.244) with Microsoft SMTP Server (version=TLS1_2,
cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Sat, 8 Jul
2023 16:57:31 +0800
From: Miaohe Lin <linmiaohe@huawei.com>
To: <akpm@linux-foundation.org>, <naoya.horiguchi@nec.com>
CC: <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
<linmiaohe@huawei.com>
Subject: [PATCH 8/8] mm: memory-failure: fix race window when trying to get
hugetlb folio
Date: Sat, 8 Jul 2023 16:57:44 +0800
Message-ID: <20230708085744.3599311-9-linmiaohe@huawei.com>
X-Mailer: git-send-email 2.33.0
In-Reply-To: <20230708085744.3599311-1-linmiaohe@huawei.com>
References: <20230708085744.3599311-1-linmiaohe@huawei.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 7BIT
Content-Type: text/plain; charset=US-ASCII
X-Originating-IP: [10.174.151.185]
X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To
canpemm500002.china.huawei.com (7.192.104.244)
X-CFilter-Loop: Reflected
X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED,
RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_PASS,
T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6
X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on
lindbergh.monkeyblade.net
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org
X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?=
X-GMAIL-THRID: =?utf-8?q?1770847079708933741?=
X-GMAIL-MSGID: =?utf-8?q?1770847079708933741?=
|
| Series |
A few fixup and cleanup patches for memory-failure
|
|
Commit Message
Miaohe Lin
July 8, 2023, 8:57 a.m. UTC
page_folio() is fetched before calling get_hwpoison_hugetlb_folio()
without hugetlb_lock being held. So hugetlb page could be demoted
before get_hwpoison_hugetlb_folio() holding hugetlb_lock but after
page_folio() is fetched. So get_hwpoison_hugetlb_folio() will hold
unexpected extra refcnt of hugetlb folio while leaving demoted page
un-refcnted.
Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
---
mm/memory-failure.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)
Comments
On Sat, Jul 08, 2023 at 04:57:44PM +0800, Miaohe Lin wrote: > page_folio() is fetched before calling get_hwpoison_hugetlb_folio() > without hugetlb_lock being held. So hugetlb page could be demoted > before get_hwpoison_hugetlb_folio() holding hugetlb_lock but after > page_folio() is fetched. So get_hwpoison_hugetlb_folio() will hold > unexpected extra refcnt of hugetlb folio while leaving demoted page > un-refcnted. Very nice, thank you for finding the issue. > > Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation") > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > mm/memory-failure.c | 18 ++++++++++++++---- > 1 file changed, 14 insertions(+), 4 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index 76d88d27cdbe..066bf57f2d22 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -1388,8 +1388,14 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags) > bool hugetlb = false; > > ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, false); > - if (hugetlb) > - return ret; > + if (hugetlb) { > + if (folio == page_folio(page)) > + return ret; Some short comment about the race against demotion here is helpful. Anyway, the patch looks good to me. Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> > + if (ret > 0) { > + folio_put(folio); > + folio = page_folio(page); > + } > + } > > /* > * This check prevents from calling folio_try_get() for any > @@ -1478,8 +1484,12 @@ static int __get_unpoison_page(struct page *page) > bool hugetlb = false; > > ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, true); > - if (hugetlb) > - return ret; > + if (hugetlb) { > + if (folio == page_folio(page)) > + return ret; > + if (ret > 0) > + folio_put(folio); > + } > > /* > * PageHWPoisonTakenOff pages are not only marked as PG_hwpoison, > -- > 2.33.0 > > >
On 2023/7/10 15:58, Naoya Horiguchi wrote: > On Sat, Jul 08, 2023 at 04:57:44PM +0800, Miaohe Lin wrote: >> page_folio() is fetched before calling get_hwpoison_hugetlb_folio() >> without hugetlb_lock being held. So hugetlb page could be demoted >> before get_hwpoison_hugetlb_folio() holding hugetlb_lock but after >> page_folio() is fetched. So get_hwpoison_hugetlb_folio() will hold >> unexpected extra refcnt of hugetlb folio while leaving demoted page >> un-refcnted. > > Very nice, thank you for finding the issue. > >> >> Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation") >> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >> --- >> mm/memory-failure.c | 18 ++++++++++++++---- >> 1 file changed, 14 insertions(+), 4 deletions(-) >> >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >> index 76d88d27cdbe..066bf57f2d22 100644 >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -1388,8 +1388,14 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags) >> bool hugetlb = false; >> >> ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, false); >> - if (hugetlb) >> - return ret; >> + if (hugetlb) { >> + if (folio == page_folio(page)) >> + return ret; > > Some short comment about the race against demotion here is helpful. Does the below comment makes sense to you? " Make sure hugetlb demotion did not happen from under us. " > > Anyway, the patch looks good to me. > > Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Many thanks for your review and comment, Naoya.
On Mon, Jul 10, 2023 at 04:32:27PM +0800, Miaohe Lin wrote: > On 2023/7/10 15:58, Naoya Horiguchi wrote: > > On Sat, Jul 08, 2023 at 04:57:44PM +0800, Miaohe Lin wrote: > >> page_folio() is fetched before calling get_hwpoison_hugetlb_folio() > >> without hugetlb_lock being held. So hugetlb page could be demoted > >> before get_hwpoison_hugetlb_folio() holding hugetlb_lock but after > >> page_folio() is fetched. So get_hwpoison_hugetlb_folio() will hold > >> unexpected extra refcnt of hugetlb folio while leaving demoted page > >> un-refcnted. > > > > Very nice, thank you for finding the issue. > > > >> > >> Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation") > >> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > >> --- > >> mm/memory-failure.c | 18 ++++++++++++++---- > >> 1 file changed, 14 insertions(+), 4 deletions(-) > >> > >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c > >> index 76d88d27cdbe..066bf57f2d22 100644 > >> --- a/mm/memory-failure.c > >> +++ b/mm/memory-failure.c > >> @@ -1388,8 +1388,14 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags) > >> bool hugetlb = false; > >> > >> ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, false); > >> - if (hugetlb) > >> - return ret; > >> + if (hugetlb) { > >> + if (folio == page_folio(page)) > >> + return ret; > > > > Some short comment about the race against demotion here is helpful. > > Does the below comment makes sense to you? > > " > Make sure hugetlb demotion did not happen from under us. > " Yes, this sounds fine. Thanks, Naoya Horiguchi
On 2023/7/10 16:39, Naoya Horiguchi wrote: > On Mon, Jul 10, 2023 at 04:32:27PM +0800, Miaohe Lin wrote: >> On 2023/7/10 15:58, Naoya Horiguchi wrote: >>> On Sat, Jul 08, 2023 at 04:57:44PM +0800, Miaohe Lin wrote: >>>> page_folio() is fetched before calling get_hwpoison_hugetlb_folio() >>>> without hugetlb_lock being held. So hugetlb page could be demoted >>>> before get_hwpoison_hugetlb_folio() holding hugetlb_lock but after >>>> page_folio() is fetched. So get_hwpoison_hugetlb_folio() will hold >>>> unexpected extra refcnt of hugetlb folio while leaving demoted page >>>> un-refcnted. >>> >>> Very nice, thank you for finding the issue. >>> >>>> >>>> Fixes: 25182f05ffed ("mm,hwpoison: fix race with hugetlb page allocation") >>>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >>>> --- >>>> mm/memory-failure.c | 18 ++++++++++++++---- >>>> 1 file changed, 14 insertions(+), 4 deletions(-) >>>> >>>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >>>> index 76d88d27cdbe..066bf57f2d22 100644 >>>> --- a/mm/memory-failure.c >>>> +++ b/mm/memory-failure.c >>>> @@ -1388,8 +1388,14 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags) >>>> bool hugetlb = false; >>>> >>>> ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, false); >>>> - if (hugetlb) >>>> - return ret; >>>> + if (hugetlb) { >>>> + if (folio == page_folio(page)) >>>> + return ret; >>> >>> Some short comment about the race against demotion here is helpful. >> >> Does the below comment makes sense to you? >> >> " >> Make sure hugetlb demotion did not happen from under us. >> " > > Yes, this sounds fine. Will do it in v2. Thanks. > > Thanks, > Naoya Horiguchi > > . >
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 76d88d27cdbe..066bf57f2d22 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1388,8 +1388,14 @@ static int __get_hwpoison_page(struct page *page, unsigned long flags) bool hugetlb = false; ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, false); - if (hugetlb) - return ret; + if (hugetlb) { + if (folio == page_folio(page)) + return ret; + if (ret > 0) { + folio_put(folio); + folio = page_folio(page); + } + } /* * This check prevents from calling folio_try_get() for any @@ -1478,8 +1484,12 @@ static int __get_unpoison_page(struct page *page) bool hugetlb = false; ret = get_hwpoison_hugetlb_folio(folio, &hugetlb, true); - if (hugetlb) - return ret; + if (hugetlb) { + if (folio == page_folio(page)) + return ret; + if (ret > 0) + folio_put(folio); + } /* * PageHWPoisonTakenOff pages are not only marked as PG_hwpoison,