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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 87F48C43461 for ; Thu, 17 Sep 2020 18:47:04 +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 C46BC2075B for ; Thu, 17 Sep 2020 18:47:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ykMF/G33" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C46BC2075B Authentication-Results: mail.kernel.org; dmarc=none (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:In-Reply-To:MIME-Version:Date:Message-ID:From: References:To:Subject:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9A8lggsh+gA6aX0dGVfXhQ/NUcf1TRrZcWIjvLSCH+A=; b=ykMF/G33x/L4grkcKlVs9W28R oo2/wch4Nh5Qc4PnQXZuTeYWiW3cnnWu5XBJj/mhQgn9YCLbBAraAPY5ts/Vu2hl710Fz9hVjM5es o+FZUuZPV3M+sOJZ3QdRHGEyzOLqiSZfUpEOa8c2N2Kae3gEc2IeHOCzsd7W7gto3z4ZiT7EESplB ssmETFBTu8MRp41k4WGzmoLSCub77K5JWisEWnuscJq8sKYaXmK6ILz9EDi9m7WfqiLHy96MEOrjd B0ercKvAeNteqiVRGhs65JJIRGf36P2tu/93nO1o9YKyitvgXHEXE8nR1SLOi32qRCMFjxHysLN7k jOMBtSrLA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kIyua-0000fb-Qw; Thu, 17 Sep 2020 18:45:40 +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 1kIyuY-0000em-6c for linux-arm-kernel@lists.infradead.org; Thu, 17 Sep 2020 18:45:39 +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 D847011D4; Thu, 17 Sep 2020 11:45:35 -0700 (PDT) Received: from [10.37.8.97] (unknown [10.37.8.97]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A75B33F718; Thu, 17 Sep 2020 11:45:32 -0700 (PDT) Subject: Re: [PATCH v2 27/37] arm64: mte: Switch GCR_EL1 in kernel entry and exit To: Catalin Marinas , Andrey Konovalov References: <20200917165221.GF10662@gaia> From: Vincenzo Frascino Message-ID: Date: Thu, 17 Sep 2020 19:47:59 +0100 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: <20200917165221.GF10662@gaia> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200917_144538_293023_A3D4E840 X-CRM114-Status: GOOD ( 12.86 ) 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: linux-arm-kernel@lists.infradead.org, Marco Elver , Elena Petrova , Kevin Brodsky , Will Deacon , Branislav Rankov , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Potapenko , Dmitry Vyukov , Andrey Ryabinin , Andrew Morton , Evgenii Stepanov 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 On 9/17/20 5:52 PM, Catalin Marinas wrote: >> +void mte_init_tags(u64 max_tag) >> +{ >> + u64 incl = GENMASK(max_tag & MTE_TAG_MAX, 0); >> + >> + gcr_kernel_excl = ~incl & SYS_GCR_EL1_EXCL_MASK; >> +} > Do we need to set the actual GCR_EL1 register here? We may not get an > exception by the time KASAN starts using it. It is ok not setting it here because to get exceptions cpuframework mte enable needs to be executed first. In that context we set even the register. -- Regards, Vincenzo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel