From patchwork Thu Jan 7 17:29:06 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincenzo Frascino X-Patchwork-Id: 12004561 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 CE08CC43381 for ; Thu, 7 Jan 2021 17:31:48 +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 8EC65233CE for ; Thu, 7 Jan 2021 17:31:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8EC65233CE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Si+WzZ9Mtk9L+6cHueW2pbKI1eA943XY2jvh/xVfgwc=; b=QQxRpeFlHfosIQhlTmkUPpI2p DkE+CZ77zg+PydFd1tgLE4CIFZgEsFLaMW9iBXEIyT7GCN27qAm2Qbb/LroDbkANQWU9JS72nFYfh JLw0aAJcWeUGiwlPes09kXYbm4kUq7HlES03UjMcGDVV69BofY95SaxDviZHXpKufjVoX9yk31Xsz QMw61mjvap4jFxC2gI26a00U3CpNk+RVeYFUpgWtDWhFvDBzQ7tPFb85kc5td7tNiwMfozfM83CEF goRmDt14pt5gb9JJf/rS423lt+bYHRFUM9Swt0x0wyzzYiX+QX6Dq6lMxEWRxfJCthydEilh6XgeZ HrFdAPuiQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kxZ7N-0005Kr-0c; Thu, 07 Jan 2021 17:30:37 +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 1kxZ7F-0005Jb-7h for linux-arm-kernel@lists.infradead.org; Thu, 07 Jan 2021 17:30:30 +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 7B05F106F; Thu, 7 Jan 2021 09:30:24 -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 CA71E3F719; Thu, 7 Jan 2021 09:30:22 -0800 (PST) From: Vincenzo Frascino To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com Subject: [PATCH v2 2/4] arm64: mte: Add asynchronous mode support Date: Thu, 7 Jan 2021 17:29:06 +0000 Message-Id: <20210107172908.42686-3-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210107172908.42686-1-vincenzo.frascino@arm.com> References: <20210107172908.42686-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210107_123029_409872_8EF64F55 X-CRM114-Status: GOOD ( 13.89 ) 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 , Branislav Rankov , Alexander Potapenko , Evgenii Stepanov , Andrey Konovalov , Andrey Ryabinin , Vincenzo Frascino , Will Deacon , Dmitry Vyukov 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(); }