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 X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 16D89C2D0A3 for ; Thu, 12 Nov 2020 09:37:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6CB1221FE for ; Thu, 12 Nov 2020 09:37:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727614AbgKLJg7 (ORCPT ); Thu, 12 Nov 2020 04:36:59 -0500 Received: from foss.arm.com ([217.140.110.172]:45262 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725928AbgKLJg7 (ORCPT ); Thu, 12 Nov 2020 04:36:59 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 932FD139F; Thu, 12 Nov 2020 01:36:58 -0800 (PST) Received: from [10.37.12.33] (unknown [10.37.12.33]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 7C3EF3F73C; Thu, 12 Nov 2020 01:36:55 -0800 (PST) Subject: Re: [PATCH v9 28/44] arm64: mte: Reset the page tag in page->flags To: Catalin Marinas , Andrey Konovalov Cc: Will Deacon , Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , Andrew Morton , kasan-dev@googlegroups.com, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <4a7819f8942922451e8075d7003f7df357919dfc.1605046192.git.andreyknvl@google.com> <20201112093130.GD29613@gaia> From: Vincenzo Frascino Message-ID: Date: Thu, 12 Nov 2020 09:39:59 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201112093130.GD29613@gaia> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/12/20 9:31 AM, Catalin Marinas wrote: > On Tue, Nov 10, 2020 at 11:10:25PM +0100, Andrey Konovalov wrote: >> diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c >> index 70a71f38b6a9..f0efa4847e2f 100644 >> --- a/arch/arm64/mm/copypage.c >> +++ b/arch/arm64/mm/copypage.c >> @@ -23,6 +23,7 @@ void copy_highpage(struct page *to, struct page *from) >> >> if (system_supports_mte() && test_bit(PG_mte_tagged, &from->flags)) { >> set_bit(PG_mte_tagged, &to->flags); >> + page_kasan_tag_reset(to); >> mte_copy_page_tags(kto, kfrom); > > Any reason why this doesn't have an smp_wmb() between resetting the tags > and copying them into kto? > Yes, the reason is I am not sure why it disappeared from the submitted patch ;) I am going to respin the patch. -- Regards, Vincenzo