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 CF14CC433EF for ; Thu, 10 Feb 2022 12:37:45 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 352D96B007E; Thu, 10 Feb 2022 07:37:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2DA818D0001; Thu, 10 Feb 2022 07:37:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 17AB56B0081; Thu, 10 Feb 2022 07:37:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0067.hostedemail.com [216.40.44.67]) by kanga.kvack.org (Postfix) with ESMTP id 094886B007E for ; Thu, 10 Feb 2022 07:37:45 -0500 (EST) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id B688C1D1661 for ; Thu, 10 Feb 2022 12:37:44 +0000 (UTC) X-FDA: 79126821648.28.9C68116 Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) by imf15.hostedemail.com (Postfix) with ESMTP id 4D123A0011 for ; Thu, 10 Feb 2022 12:37:44 +0000 (UTC) Received: by mail-pl1-f181.google.com with SMTP id x4so1707810plb.4 for ; Thu, 10 Feb 2022 04:37:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=tKpVSiHHtaj87FMK/TeB9fab8FVNXtwv8Xc4GuIj/Kg=; b=fQy8vfqpU9cS9VF0UkKIV2NNCg0tQEdPXZgAQyveKt+IqZMhPhSLL2L91pt18Zg06N vNvRvBopSQe6m1BOl262fpfSHiT8PTxbkyLfR2s8UUCSsGqv6jhJr5tF046QxWGKPvQ4 j1luq5AgDAl2iOiKPsSWugj44vi8gpSPdoJjaafW25tBKv8lpwq+uDQF3SBoV0mX0uWh oeE64v4w2/BhLSM2qEBvn2JtkZhtGWhP1r03BRWqGEilJv2WHtsOlbBI0BeMeSkYlft6 BtL8Es/U26EonkHfhoxdHnW89rwm0do83Rj77+xgClJ16smYtj669p2PtIeIaa0K/Otd MINg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=tKpVSiHHtaj87FMK/TeB9fab8FVNXtwv8Xc4GuIj/Kg=; b=rWSZYYiEK7wWjDkxZGNhCR0XScr0GECMFqM0AUcS4SGrHpif1wqqbJIE5bcccFwozm Nokz6pw64obTB+LXzbFg4xfFVWyUiVZqkWyI9FZsTS28htK+MBSl76woPS4W66Vuo6Ok +ADroNQYwMb2v4NRUmCzoVmqlmCiI+gBBn+Spab0CP0rrjurQaqcNEZzfKLsE8hp43Q1 +/fCjTlcm+VQpytBu3d4isYcK8cGpwkG6NbFVk3UsOAe6nH6SOzh6DaY1uzmmcPTwQdf zWoMoGRAG5mlOKw0fX/t7c6fP+b0ATEbuCr63AJf2eDqaW9gaZMsEQGrExgE99BT8Eaf SgwQ== X-Gm-Message-State: AOAM530TTXMkVOB85c1wbCLqy+C3r9zsnx0dX59kyh/Wk7sjteo+4dpu 872G3ce+c4P6oddPlJQ5spGt5w== X-Google-Smtp-Source: ABdhPJyGp2GsZvSDMqpR5iLkDxZjE53dEk3dm5rB0VkaJA74+KantoyMJ9LJ6pDdNdp3d3NZ3dXk6A== X-Received: by 2002:a17:90b:1c0e:: with SMTP id oc14mr2638965pjb.2.1644496663463; Thu, 10 Feb 2022 04:37:43 -0800 (PST) Received: from FVFYT0MHHV2J.tiktokcdn.com ([139.177.225.237]) by smtp.gmail.com with ESMTPSA id i8sm11767812pgf.94.2022.02.10.04.37.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Feb 2022 04:37:43 -0800 (PST) From: Muchun Song To: akpm@linux-foundation.org, zi.yan@cs.rutgers.edu, kirill.shutemov@linux.intel.com, rientjes@google.com, lars.persson@axis.com, mike.kravetz@oracle.com, ziy@nvidia.com Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, duanxiongchun@bytedance.com, fam.zheng@bytedance.com, Muchun Song Subject: [PATCH v5 5/7] mm: shmem: fix missing cache flush in shmem_mfill_atomic_pte() Date: Thu, 10 Feb 2022 20:30:56 +0800 Message-Id: <20220210123058.79206-6-songmuchun@bytedance.com> X-Mailer: git-send-email 2.32.0 (Apple Git-132) In-Reply-To: <20220210123058.79206-1-songmuchun@bytedance.com> References: <20220210123058.79206-1-songmuchun@bytedance.com> MIME-Version: 1.0 X-Rspamd-Queue-Id: 4D123A0011 Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=fQy8vfqp; spf=pass (imf15.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.214.181 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com; dmarc=pass (policy=none) header.from=bytedance.com X-Stat-Signature: yqinfwjkyqs1qc4xyurdsi1pe4jdbjxf X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1644496664-666816 Content-Transfer-Encoding: quoted-printable 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: The userfaultfd calls shmem_mfill_atomic_pte() which does not do any cache flushing for the target page. Then the target page will be mapped to the user space with a different address (user address), which might have an alias issue with the kernel address used to copy the data from th= e user to. Insert flush_dcache_page() in non-zero-page case. And replace clear_highpage() with clear_user_highpage() which already considers the cache maintenance. Fixes: 8d1039634206 ("userfaultfd: shmem: add shmem_mfill_zeropage_pte fo= r userfaultfd support") Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for = userfaultfd support") Signed-off-by: Muchun Song --- mm/shmem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/mm/shmem.c b/mm/shmem.c index eb0fd9001130..2e17ec9231a2 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -2371,8 +2371,10 @@ int shmem_mfill_atomic_pte(struct mm_struct *dst_m= m, /* don't free the page */ goto out_unacct_blocks; } + + flush_dcache_page(page); } else { /* ZEROPAGE */ - clear_highpage(page); + clear_user_highpage(page, dst_addr); } } else { page =3D *pagep; --=20 2.11.0