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=-8.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 0B9F2C56201 for ; Thu, 12 Nov 2020 16:43:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B6E4121D7F for ; Thu, 12 Nov 2020 16:43:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729055AbgKLQnF (ORCPT ); Thu, 12 Nov 2020 11:43:05 -0500 Received: from foss.arm.com ([217.140.110.172]:53962 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728684AbgKLQnE (ORCPT ); Thu, 12 Nov 2020 11:43:04 -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 5F3A7142F; Thu, 12 Nov 2020 08:43:04 -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 5280A3F73C; Thu, 12 Nov 2020 08:43:01 -0800 (PST) Subject: Re: [PATCH v9 30/44] arm64: kasan: Allow enabling in-kernel MTE 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: <5ce2fc45920e59623a4a9d8d39b6c96792f1e055.1605046192.git.andreyknvl@google.com> <20201112094354.GF29613@gaia> From: Vincenzo Frascino Message-ID: <6a72b3e3-1b35-5ead-bfff-f4e2f3d5296e@arm.com> Date: Thu, 12 Nov 2020 16:46:05 +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: <20201112094354.GF29613@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 Hi Catalin, missed this one. On 11/12/20 9:43 AM, Catalin Marinas wrote: > On Tue, Nov 10, 2020 at 11:10:27PM +0100, Andrey Konovalov wrote: >> From: Vincenzo Frascino >> >> Hardware tag-based KASAN relies on Memory Tagging Extension (MTE) >> feature and requires it to be enabled. MTE supports >> >> This patch adds a new mte_init_tags() helper, that enables MTE in >> Synchronous mode in EL1 and is intended to be called from KASAN runtime >> during initialization. > > There's no mte_init_tags() in this function. > >> diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c >> index 600b26d65b41..7f477991a6cf 100644 >> --- a/arch/arm64/kernel/mte.c >> +++ b/arch/arm64/kernel/mte.c >> @@ -129,6 +129,13 @@ void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag) >> return ptr; >> } >> >> +void mte_enable(void) >> +{ >> + /* Enable MTE Sync Mode for EL1. */ >> + sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_SYNC); >> + isb(); >> +} > > Nitpick: maybe rename this to mte_enable_kernel() since MTE is already > enabled for user apps. > I will fix this in the next iteration. -- Regards, Vincenzo