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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D05AC433EF for ; Mon, 11 Jul 2022 09:52:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233972AbiGKJws (ORCPT ); Mon, 11 Jul 2022 05:52:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56990 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233270AbiGKJwB (ORCPT ); Mon, 11 Jul 2022 05:52:01 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4CF32ACEE5; Mon, 11 Jul 2022 02:25:12 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id F04706124E; Mon, 11 Jul 2022 09:25:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9261C34115; Mon, 11 Jul 2022 09:25:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1657531510; bh=9K04RVcc5+Of6dPmUZUF7MfhV/bdoktf5T5hjkB0ntw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eXC9+49lgVNTgEhlxEohSlTfn5cog2wd29rOWzRTLSYtks6fzG3xWY98eg5xbQ9/J E//BuVMT5nsJpvW7jJALjtX+i1CRJza+R9FJgXFqpFsaCuuWmcxNf83jeydohP4RU7 H+8dSmjwEam0cLaLUyYAp9ffsuz1LI85Jr9xt8oE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Miaohe Lin , Naoya Horiguchi , Tony Luck , Borislav Petkov , Mike Kravetz , Yang Shi , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 5.15 129/230] mm/memory-failure.c: fix race with changing page compound again Date: Mon, 11 Jul 2022 11:06:25 +0200 Message-Id: <20220711090607.725243061@linuxfoundation.org> X-Mailer: git-send-email 2.37.0 In-Reply-To: <20220711090604.055883544@linuxfoundation.org> References: <20220711090604.055883544@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Miaohe Lin [ Upstream commit 888af2701db79b9b27c7e37f9ede528a5ca53b76 ] Patch series "A few fixup patches for memory failure", v2. This series contains a few patches to fix the race with changing page compound page, make non-LRU movable pages unhandlable and so on. More details can be found in the respective changelogs. There is a race window where we got the compound_head, the hugetlb page could be freed to buddy, or even changed to another compound page just before we try to get hwpoison page. Think about the below race window: CPU 1 CPU 2 memory_failure_hugetlb struct page *head = compound_head(p); hugetlb page might be freed to buddy, or even changed to another compound page. get_hwpoison_page -- page is not what we want now... If this race happens, just bail out. Also MF_MSG_DIFFERENT_PAGE_SIZE is introduced to record this event. [akpm@linux-foundation.org: s@/**@/*@, per Naoya Horiguchi] Link: https://lkml.kernel.org/r/20220312074613.4798-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220312074613.4798-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin Acked-by: Naoya Horiguchi Cc: Tony Luck Cc: Borislav Petkov Cc: Mike Kravetz Cc: Yang Shi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/linux/mm.h | 1 + include/ras/ras_event.h | 1 + mm/memory-failure.c | 12 ++++++++++++ 3 files changed, 14 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index 85205adcdd0d..7a80a08eec84 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3167,6 +3167,7 @@ enum mf_action_page_type { MF_MSG_BUDDY_2ND, MF_MSG_DAX, MF_MSG_UNSPLIT_THP, + MF_MSG_DIFFERENT_PAGE_SIZE, MF_MSG_UNKNOWN, }; diff --git a/include/ras/ras_event.h b/include/ras/ras_event.h index 0bdbc0d17d2f..cac13ff1d6eb 100644 --- a/include/ras/ras_event.h +++ b/include/ras/ras_event.h @@ -376,6 +376,7 @@ TRACE_EVENT(aer_event, EM ( MF_MSG_BUDDY_2ND, "free buddy page (2nd try)" ) \ EM ( MF_MSG_DAX, "dax page" ) \ EM ( MF_MSG_UNSPLIT_THP, "unsplit thp" ) \ + EM ( MF_MSG_DIFFERENT_PAGE_SIZE, "different page size" ) \ EMe ( MF_MSG_UNKNOWN, "unknown page" ) /* diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 5664bafd5e77..a4d70c21c146 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -741,6 +741,7 @@ static const char * const action_page_types[] = { [MF_MSG_BUDDY_2ND] = "free buddy page (2nd try)", [MF_MSG_DAX] = "dax page", [MF_MSG_UNSPLIT_THP] = "unsplit thp", + [MF_MSG_DIFFERENT_PAGE_SIZE] = "different page size", [MF_MSG_UNKNOWN] = "unknown page", }; @@ -1461,6 +1462,17 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags) } lock_page(head); + + /* + * The page could have changed compound pages due to race window. + * If this happens just bail out. + */ + if (!PageHuge(p) || compound_head(p) != head) { + action_result(pfn, MF_MSG_DIFFERENT_PAGE_SIZE, MF_IGNORED); + res = -EBUSY; + goto out; + } + page_flags = head->flags; /* -- 2.35.1