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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 1FAF3C433E6 for ; Wed, 6 Jan 2021 11:57:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E39F523110 for ; Wed, 6 Jan 2021 11:57:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726525AbhAFL53 (ORCPT ); Wed, 6 Jan 2021 06:57:29 -0500 Received: from foss.arm.com ([217.140.110.172]:40014 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726473AbhAFL52 (ORCPT ); Wed, 6 Jan 2021 06:57:28 -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 9119211B3; Wed, 6 Jan 2021 03:56:42 -0800 (PST) Received: from e119884-lin.cambridge.arm.com (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E5D573F70D; Wed, 6 Jan 2021 03:56:40 -0800 (PST) From: Vincenzo Frascino To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com Cc: Vincenzo Frascino , Catalin Marinas , Will Deacon , Dmitry Vyukov , Andrey Ryabinin , Alexander Potapenko , Marco Elver , Evgenii Stepanov , Branislav Rankov , Andrey Konovalov Subject: [PATCH 2/4] arm64: mte: Add asynchronous mode support Date: Wed, 6 Jan 2021 11:55:17 +0000 Message-Id: <20210106115519.32222-3-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210106115519.32222-1-vincenzo.frascino@arm.com> References: <20210106115519.32222-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org MTE provides an asynchronous mode for detecting tag exceptions. In particular instead of triggering a fault the arm64 core updates a register which is checked by the kernel at the first entry after the tag exception has occurred. Add support for MTE asynchronous mode. The exception handling mechanism will be added with a future patch. Note: KASAN HW activates async mode via kasan.mode kernel parameter. The default mode is set to synchronous. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/kernel/mte.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 24a273d47df1..5d992e16b420 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -153,8 +153,35 @@ void mte_init_tags(u64 max_tag) void mte_enable_kernel(enum kasan_arg_mode mode) { - /* Enable MTE Sync Mode for EL1. */ - sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_SYNC); + const char *m; + + /* Preset parameter values based on the mode. */ + switch (mode) { + case KASAN_ARG_MODE_OFF: + return; + case KASAN_ARG_MODE_LIGHT: + /* Enable MTE Async Mode for EL1. */ + sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_ASYNC); + m = "asynchronous"; + break; + case KASAN_ARG_MODE_DEFAULT: + case KASAN_ARG_MODE_PROD: + case KASAN_ARG_MODE_FULL: + /* Enable MTE Sync Mode for EL1. */ + sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_SYNC); + m = "synchronous"; + break; + default: + /* + * kasan mode should be always set hence we should + * not reach this condition. + */ + WARN_ON_ONCE(1); + return; + } + + pr_info_once("MTE: enabled in %s mode at EL1\n", m); + isb(); } -- 2.29.2 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=-17.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 26355C433DB for ; Wed, 6 Jan 2021 11:58:21 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DD81823110 for ; 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Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kx7Qr-0003QE-4B; Wed, 06 Jan 2021 11:56:53 +0000 Received: from foss.arm.com ([217.140.110.172]) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kx7Qh-0003NI-8M for linux-arm-kernel@lists.infradead.org; Wed, 06 Jan 2021 11:56:44 +0000 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 9119211B3; Wed, 6 Jan 2021 03:56:42 -0800 (PST) Received: from e119884-lin.cambridge.arm.com (e119884-lin.cambridge.arm.com [10.1.196.72]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E5D573F70D; Wed, 6 Jan 2021 03:56:40 -0800 (PST) From: Vincenzo Frascino To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com Subject: [PATCH 2/4] arm64: mte: Add asynchronous mode support Date: Wed, 6 Jan 2021 11:55:17 +0000 Message-Id: <20210106115519.32222-3-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210106115519.32222-1-vincenzo.frascino@arm.com> References: <20210106115519.32222-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210106_065643_402408_A352CA1D X-CRM114-Status: GOOD ( 14.28 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Marco Elver , Catalin Marinas , Will Deacon , Branislav Rankov , Alexander Potapenko , Evgenii Stepanov , Andrey Konovalov , Andrey Ryabinin , Vincenzo Frascino , Dmitry Vyukov Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org MTE provides an asynchronous mode for detecting tag exceptions. In particular instead of triggering a fault the arm64 core updates a register which is checked by the kernel at the first entry after the tag exception has occurred. Add support for MTE asynchronous mode. The exception handling mechanism will be added with a future patch. Note: KASAN HW activates async mode via kasan.mode kernel parameter. The default mode is set to synchronous. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/kernel/mte.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 24a273d47df1..5d992e16b420 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -153,8 +153,35 @@ void mte_init_tags(u64 max_tag) void mte_enable_kernel(enum kasan_arg_mode mode) { - /* Enable MTE Sync Mode for EL1. */ - sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_SYNC); + const char *m; + + /* Preset parameter values based on the mode. */ + switch (mode) { + case KASAN_ARG_MODE_OFF: + return; + case KASAN_ARG_MODE_LIGHT: + /* Enable MTE Async Mode for EL1. */ + sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_ASYNC); + m = "asynchronous"; + break; + case KASAN_ARG_MODE_DEFAULT: + case KASAN_ARG_MODE_PROD: + case KASAN_ARG_MODE_FULL: + /* Enable MTE Sync Mode for EL1. */ + sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_SYNC); + m = "synchronous"; + break; + default: + /* + * kasan mode should be always set hence we should + * not reach this condition. + */ + WARN_ON_ONCE(1); + return; + } + + pr_info_once("MTE: enabled in %s mode at EL1\n", m); + isb(); } -- 2.29.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel