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, SIGNED_OFF_BY,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 04FD0C4741F for ; Thu, 5 Nov 2020 17:43:57 +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 7E8E7206CA for ; Thu, 5 Nov 2020 17:43:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ZPVPhvFm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7E8E7206CA 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:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=dmhcAwqH7SVIzTeYjMNE/NbKGSk9uPHAgWXellKWIRk=; b=ZPVPhvFmgjLtp+J875ywVbnt+ hauIH89rnSbVxMJn8H89l+h3ASAM8cPF4+g+/3YP+RArHb2Rs49XCJFnxW8Q/2Fq10HsTi0CsjkeT 2/WAegoYgPhdeEyH0TNVJ0f9c3ng3d7+zY328Aty2w22uns95mra2hzl4MFkaMWUlKbpcO45rD1Bm N2yppnblb9ZA4j25yyV927mST69Vag1Umbvl3WYICahzxj3ti22FPUDkQJjXx/I5bWhFqLHw6eAOQ 4aQRH87sHN7Ra92HSswJFMtJlSwElgRVU3Cp6xO0xTXi0fubu6OsZzr4BhzbHCVoC+1pMHtdFKaKM EAuZOaH1w==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kajHe-0007sZ-4r; Thu, 05 Nov 2020 17:42:50 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kajHb-0007rg-Ej for linux-arm-kernel@lists.infradead.org; Thu, 05 Nov 2020 17:42:48 +0000 Received: from gaia (unknown [2.26.170.190]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 44E29206CA; Thu, 5 Nov 2020 17:42:42 +0000 (UTC) Date: Thu, 5 Nov 2020 17:42:39 +0000 From: Catalin Marinas To: Andrey Konovalov Subject: Re: [PATCH v8 32/43] arm64: mte: Switch GCR_EL1 in kernel entry and exit Message-ID: <20201105174239.GI30030@gaia> References: <5d9ece04df8e9d60e347a2f6f96b8c52316bfe66.1604531793.git.andreyknvl@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5d9ece04df8e9d60e347a2f6f96b8c52316bfe66.1604531793.git.andreyknvl@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201105_124247_575841_857C1B0D X-CRM114-Status: GOOD ( 15.01 ) 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 , Kevin Brodsky , Will Deacon , Branislav Rankov , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Alexander Potapenko , Evgenii Stepanov , Andrey Ryabinin , Andrew Morton , 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 On Thu, Nov 05, 2020 at 12:18:47AM +0100, Andrey Konovalov wrote: > From: Vincenzo Frascino > > When MTE is present, the GCR_EL1 register contains the tags mask that > allows to exclude tags from the random generation via the IRG instruction. > > With the introduction of the new Tag-Based KASAN API that provides a > mechanism to reserve tags for special reasons, the MTE implementation > has to make sure that the GCR_EL1 setting for the kernel does not affect > the userspace processes and viceversa. > > Save and restore the kernel/user mask in GCR_EL1 in kernel entry and exit. > > Signed-off-by: Vincenzo Frascino > Co-developed-by: Andrey Konovalov > Signed-off-by: Andrey Konovalov Reviewed-by: Catalin Marinas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel