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 4BBD0C43334 for ; Mon, 18 Jul 2022 02:25:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233172AbiGRCZc (ORCPT ); Sun, 17 Jul 2022 22:25:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60212 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229886AbiGRCZa (ORCPT ); Sun, 17 Jul 2022 22:25:30 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E874210FED for ; Sun, 17 Jul 2022 19:25:27 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.57]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4LmQjJ50xvzjWww; Mon, 18 Jul 2022 10:22:44 +0800 (CST) Received: from [10.174.177.76] (10.174.177.76) 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 15.1.2375.24; Mon, 18 Jul 2022 10:25:25 +0800 Subject: Re: [PATCH] mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte To: Andrew Morton , Peter Xu , Axel Rasmussen CC: , , , References: <20220712130542.18836-1-linmiaohe@huawei.com> <20220713102357.8328614813db01b569650ffd@linux-foundation.org> <20220716160629.d065828c84ad2423c10f7733@linux-foundation.org> From: Miaohe Lin Message-ID: <0dcf8902-b14a-860a-cb66-46e57b6d14a9@huawei.com> Date: Mon, 18 Jul 2022 10:25:25 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: <20220716160629.d065828c84ad2423c10f7733@linux-foundation.org> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.177.76] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) 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 On 2022/7/17 7:06, Andrew Morton wrote: > On Thu, 14 Jul 2022 17:59:53 +0800 Miaohe Lin wrote: > >> On 2022/7/14 1:23, Andrew Morton wrote: >>> On Tue, 12 Jul 2022 21:05:42 +0800 Miaohe Lin wrote: >>> >>>> In MCOPY_ATOMIC_CONTINUE case with a non-shared VMA, pages in the page >>>> cache are installed in the ptes. But hugepage_add_new_anon_rmap is called >>>> for them mistakenly because they're not vm_shared. This will corrupt the >>>> page->mapping used by page cache code. >>> >>> Well that sounds bad. And theories on why this has gone unnoticed for >>> over a year? I assume this doesn't have coverage in our selftests? >> >> As discussed in another thread, when minor fault handling is proposed, only >> VM_SHARED vma is expected to be supported > > So... do we feel that this fix should be backported? And if so, is > there a suitable commit for the Fixes:? I tend to backport this fix. And I think the Fixes tag in this patch should be suitable, i.e. Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl"). Thanks. > . >