From patchwork Thu Jan 21 16:39:42 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vincenzo Frascino X-Patchwork-Id: 12037027 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=-16.9 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 89A23C433E0 for ; Thu, 21 Jan 2021 16:42:47 +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 F0DED23A23 for ; Thu, 21 Jan 2021 16:42:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0DED23A23 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=nwNwN0FkuNujw2v9drcNxMzxgtHcFi078s1D4SaqWdM=; b=K/cfmI640ShTVia0GAu2q7BR8 qrN+odQ9udVGIS2ry9OnIAYx63ZusvGZofDQvT9lD/rVuKxyd1mh4h0e82or5ABexHPHTfFNcp9sz aqwnMlpTNkACg0IoVfwoFGfbDLCrXPg5yhoMO6Fgpr1G4svsK9uuFfV8Er+FCSrfDQh29smTtldqH Icx9I5bcEvJC9NR1e/AgN3DrAv0SdiNyOIaGG/ZeYCgqpckksXj/dXQhWhKOxexcr3kwb2xriTbuH AOPRgC5G4m9Jly2fv3R8z5dG0pjLseFf365haDMGj+feEdEeF8zgsnKXAMQPcMaNlBByhThH9NQhO kX+3AFy1w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l2d0s-0003HP-30; Thu, 21 Jan 2021 16:40:50 +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 1l2d06-00033p-NN for linux-arm-kernel@lists.infradead.org; Thu, 21 Jan 2021 16:40:06 +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 37E9F1595; Thu, 21 Jan 2021 08:40:02 -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 8C92A3F68F; Thu, 21 Jan 2021 08:40:00 -0800 (PST) From: Vincenzo Frascino To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com Subject: [PATCH v5 5/6] arm64: mte: Expose execution mode Date: Thu, 21 Jan 2021 16:39:42 +0000 Message-Id: <20210121163943.9889-6-vincenzo.frascino@arm.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210121163943.9889-1-vincenzo.frascino@arm.com> References: <20210121163943.9889-1-vincenzo.frascino@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210121_114002_952092_C228F930 X-CRM114-Status: GOOD ( 14.45 ) 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 enabled arm64 HW can be configured in synchronous or asynchronous tagging mode of execution. In synchronous mode, an exception is triggered if a tag check fault occurs. In asynchronous mode, if a tag check fault occurs, the TFSR_EL1 register is updated asynchronously. The kernel checks the corresponding bits periodically. Introduce an API that exposes the mode of execution to the kernel. Note: This API will be used by KASAN KUNIT tests to forbid the execution when async mode is enable. Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Vincenzo Frascino --- arch/arm64/include/asm/memory.h | 1 + arch/arm64/include/asm/mte-kasan.h | 6 ++++++ arch/arm64/kernel/mte.c | 8 ++++++++ 3 files changed, 15 insertions(+) diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index df96b9c10b81..1d4eef519fa6 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -233,6 +233,7 @@ static inline const void *__tag_set(const void *addr, u8 tag) #ifdef CONFIG_KASAN_HW_TAGS #define arch_enable_tagging_sync() mte_enable_kernel_sync() #define arch_enable_tagging_async() mte_enable_kernel_async() +#define arch_is_mode_sync() mte_is_mode_sync() #define arch_set_tagging_report_once(state) mte_set_report_once(state) #define arch_init_tags(max_tag) mte_init_tags(max_tag) #define arch_get_random_tag() mte_get_random_tag() diff --git a/arch/arm64/include/asm/mte-kasan.h b/arch/arm64/include/asm/mte-kasan.h index 76b6a5988ce5..c216160e805c 100644 --- a/arch/arm64/include/asm/mte-kasan.h +++ b/arch/arm64/include/asm/mte-kasan.h @@ -31,6 +31,7 @@ void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag); void mte_enable_kernel_sync(void); void mte_enable_kernel_async(void); +bool mte_is_mode_sync(void); void mte_init_tags(u64 max_tag); void mte_set_report_once(bool state); @@ -64,6 +65,11 @@ static inline void mte_enable_kernel_sync(void) { } +static inline bool mte_is_mode_sync(void) +{ + return false; +} + static inline void mte_init_tags(u64 max_tag) { } diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c index 7763ac1f2917..1cc3fc173b97 100644 --- a/arch/arm64/kernel/mte.c +++ b/arch/arm64/kernel/mte.c @@ -26,6 +26,7 @@ u64 gcr_kernel_excl __ro_after_init; static bool report_fault_once = true; +static bool __mte_mode_sync = true; static void mte_sync_page_tags(struct page *page, pte_t *ptep, bool check_swap) { @@ -169,9 +170,16 @@ void mte_enable_kernel_sync(void) void mte_enable_kernel_async(void) { + __mte_mode_sync = false; + __mte_enable_kernel("asynchronous", SCTLR_ELx_TCF_ASYNC); } +bool mte_is_mode_sync(void) +{ + return __mte_mode_sync; +} + void mte_set_report_once(bool state) { WRITE_ONCE(report_fault_once, state);