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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87E80C43334 for ; Wed, 13 Jul 2022 17:24:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A1AB8940153; Wed, 13 Jul 2022 13:24:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9C9B0940134; Wed, 13 Jul 2022 13:24:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8B930940153; Wed, 13 Jul 2022 13:24:01 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 7BECF940134 for ; Wed, 13 Jul 2022 13:24:01 -0400 (EDT) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id 49005602C9 for ; Wed, 13 Jul 2022 17:24:01 +0000 (UTC) X-FDA: 79682749482.08.E82C7C6 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf15.hostedemail.com (Postfix) with ESMTP id DFCEBA00AE for ; Wed, 13 Jul 2022 17:24:00 +0000 (UTC) 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 E232861CC2; Wed, 13 Jul 2022 17:23:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 061BEC34114; Wed, 13 Jul 2022 17:23:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1657733039; bh=Ebkngg9p9IxQV+7npBekiepQ4m1KU1CM0m96Unovhqc=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ATqSlFhJmedu3hQ5GXXO+Ayc+NQhyjkTRrgWmFvc5QqqIzAOWBprNeIvJ4SxUlU9J 11+UWBof/0fhLFWhae+tFrL/FDDRqS+cSujTuABKJZOpC1IO3kDWHakMjZkuDNWSWz BSth/7okSjDgcCRJc8dth0NJZC1cfExEnRzJwhL8= Date: Wed, 13 Jul 2022 10:23:57 -0700 From: Andrew Morton To: Miaohe Lin Cc: , , , Subject: Re: [PATCH] mm/hugetlb: avoid corrupting page->mapping in hugetlb_mcopy_atomic_pte Message-Id: <20220713102357.8328614813db01b569650ffd@linux-foundation.org> In-Reply-To: <20220712130542.18836-1-linmiaohe@huawei.com> References: <20220712130542.18836-1-linmiaohe@huawei.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit ARC-Authentication-Results: i=1; imf15.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=ATqSlFhJ; dmarc=none; spf=pass (imf15.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1657733041; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=8OpgOiq552LE3Mq9lN0Jy8Z6qzD7MzNaVeX31mSbKXI=; b=GgEaLUJoYz2ocxdgcLAtKg7iWg9p8+x3KVx8RdSKB9d7j/ZJyvclWUgtBIkhTZIGKfAmtX 4wvWdrxrU0PNw27MKiE2FdP1+Ku8G3fomXG5kz91ytzbRBoTbv1Xo62OMw9D6Zxzjr4WKM 2M6nuLlYbM7gE1QZipDirBen1QSaZCg= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1657733041; a=rsa-sha256; cv=none; b=dgIbaqB+LaQEzGac/1kBxOvU4t9KT63U9FjZwbgMYrAp9oRlzQUC9EUVNrctTOLhB7AuP5 b9dLkgjiJ6Zt6LPY/QWHiJ5K3vbnhIiILPf5cqJCFq8UKAK6rKE0RUJzmW4HB0fJulteek xscsjJMsTIdv3OP7tZeHTLVr93ad3lI= X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: DFCEBA00AE X-Stat-Signature: 9cfjjoqwtizp19kmnyeu93q8pfwiwkjx Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=ATqSlFhJ; dmarc=none; spf=pass (imf15.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspam-User: X-HE-Tag: 1657733040-886655 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 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? > --- a/mm/hugetlb.c > +++ b/mm/hugetlb.c > @@ -6038,7 +6038,7 @@ int hugetlb_mcopy_atomic_pte(struct mm_struct *dst_mm, > if (!huge_pte_none_mostly(huge_ptep_get(dst_pte))) > goto out_release_unlock; > > - if (vm_shared) { > + if (page_in_pagecache) { > page_dup_file_rmap(page, true); > } else { > ClearHPageRestoreReserve(page); > -- > 2.23.0