From patchwork Tue Aug 23 03:02:07 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miaohe Lin X-Patchwork-Id: 12951657 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 90F09C32774 for ; Tue, 23 Aug 2022 03:02:46 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3B6478D0001; Mon, 22 Aug 2022 23:02:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 31B008D0009; Mon, 22 Aug 2022 23:02:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DF71C8D000A; Mon, 22 Aug 2022 23:02:41 -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 B03558D0008 for ; Mon, 22 Aug 2022 23:02:41 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 867D9141392 for ; Tue, 23 Aug 2022 03:02:41 +0000 (UTC) X-FDA: 79829359722.19.8A0EB95 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf24.hostedemail.com (Postfix) with ESMTP id A21E118003C for ; Tue, 23 Aug 2022 03:02:40 +0000 (UTC) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MBYr355K3zhYC2; Tue, 23 Aug 2022 11:00:19 +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 15.1.2375.24; Tue, 23 Aug 2022 11:02:37 +0800 From: Miaohe Lin To: , , CC: , , , Subject: [PATCH v2 4/6] mm: hugetlb_vmemmap: add missing smp_wmb() before set_pte_at() Date: Tue, 23 Aug 2022 11:02:07 +0800 Message-ID: <20220823030209.57434-5-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20220823030209.57434-1-linmiaohe@huawei.com> References: <20220823030209.57434-1-linmiaohe@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.27] X-ClientProxiedBy: dggems701-chm.china.huawei.com (10.3.19.178) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661223760; 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; bh=79T6XfuYSWh/t3Z82G3AULdVuMX2a1/3yuX3xG/QCJ0=; b=GSabQeKV6fIbFVyYMLexMx7eq65Xmu0Si9+0N+E/zJ+h49spiUXE+dLDFBia01ci7fRHS6 w8EyR6iWhXO4fIHu2OohYGjqGuAtX+7bkQ8MOgPHGPNw6mj5uywn6hjcnL9Da+oCnh+bvz 1AoxvR890GJ1xvkFrOONDvyet/YKoAQ= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=none; spf=pass (imf24.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661223760; a=rsa-sha256; cv=none; b=djUYS2UDMJnEuTTnkDxiPERK3z2SeuxEwfqlXVuzkgWRAeeGhRHluF+xGoaloUxhsgU4CT 7QljNJpCgJmgGSY4B1OWnVT8e/dM0nUp62jRplJ9exm5k1zwwWcbMPefYMgBqvSObAYIbB o583iJ5wDl33W3jjTYehMWB1uTxRZC4= X-Stat-Signature: 7g6kz9ors5cu4duygqkp8tioy6ehjcie Authentication-Results: imf24.hostedemail.com; dkim=none; spf=pass (imf24.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com; dmarc=pass (policy=quarantine) header.from=huawei.com X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: A21E118003C X-Rspam-User: X-HE-Tag: 1661223760-887160 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 memory barrier smp_wmb() is needed to make sure that preceding stores to the page contents become visible before the below set_pte_at() write. Signed-off-by: Miaohe Lin Reviewed-by: Yin Fengwei Reviewed-by: Muchun Song --- mm/hugetlb_vmemmap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/mm/hugetlb_vmemmap.c b/mm/hugetlb_vmemmap.c index 196159000897..ba2a2596fb4e 100644 --- a/mm/hugetlb_vmemmap.c +++ b/mm/hugetlb_vmemmap.c @@ -286,6 +286,11 @@ static void vmemmap_restore_pte(pte_t *pte, unsigned long addr, copy_page(to, (void *)walk->reuse_addr); reset_struct_pages(to); + /* + * Makes sure that preceding stores to the page contents become visible + * before the set_pte_at() write. + */ + smp_wmb(); set_pte_at(&init_mm, addr, pte, mk_pte(page, pgprot)); }