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 87DD7C433EF for ; Mon, 28 Feb 2022 14:03:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236881AbiB1OER (ORCPT ); Mon, 28 Feb 2022 09:04:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42764 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230338AbiB1OEN (ORCPT ); Mon, 28 Feb 2022 09:04:13 -0500 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF40533A0B for ; Mon, 28 Feb 2022 06:03:33 -0800 (PST) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4K6hs42mnPzccx1; Mon, 28 Feb 2022 22:02:16 +0800 (CST) Received: from huawei.com (10.175.124.27) 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 15.1.2308.21; Mon, 28 Feb 2022 22:03:31 +0800 From: Miaohe Lin To: , CC: , , Subject: [PATCH 1/4] mm/memory-failure.c: fix race with changing page compound again Date: Mon, 28 Feb 2022 22:02:42 +0800 Message-ID: <20220228140245.24552-2-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20220228140245.24552-1-linmiaohe@huawei.com> References: <20220228140245.24552-1-linmiaohe@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. If this happens, just bail out. Signed-off-by: Miaohe Lin --- mm/memory-failure.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 5444a8ef4867..0d7c58340a98 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1534,6 +1534,17 @@ 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_COMPOUND, MF_IGNORED); + res = -EBUSY; + goto out; + } + page_flags = head->flags; if (hwpoison_filter(p)) { -- 2.23.0