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=-4.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,T_DKIMWL_WL_HIGH,URIBL_BLOCKED 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 0D43CC28CC0 for ; Thu, 30 May 2019 10:47:56 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (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 D6C2125790 for ; Thu, 30 May 2019 10:47:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="PsP+aETl" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D6C2125790 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+infradead-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=bombadil.20170209; h=Sender:Content-Type: Content-Transfer-Encoding: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=4hVtbl5TtsCUe+1hxfkLNyvDuFjLm47QEZaT0nJlZY4=; b=PsP+aETlER5i1cXlQreuybGd4 BejeNya8DrpvfRNv0jAckBjm05QUtVnpU70vySXGUhyAOflnOHqa85XvSStet3xkwgCsLS7rc3Sdn /q5AnnmZx825gsIWmRCNY+KMbOyaaysb/HC/MKtTy0oO7EAfAm6QUyT7LSrFIjG4LfN55zkkeV/75 HpPSpuzz+o4++mcc+JUhJKDq8CR2gqFKHJDOlruP5BDCEQdDvhEs4ADDhkRb2dourrSs7CMl7qgzs +sVV/kGOhjJYNWNIPd3lkB2zsrNSEEk9V2QUxvqQ3ywya/miopZncyiOVIJa2m4XeRthB49jbZDqb O8o33/pig==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hWIb8-00086j-N3; Thu, 30 May 2019 10:47:50 +0000 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70] helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hWIb6-000860-8b for linux-arm-kernel@lists.infradead.org; Thu, 30 May 2019 10:47:49 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 28A35374; Thu, 30 May 2019 03:47:46 -0700 (PDT) Received: from [192.168.0.21] (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CF1AB3F5AF; Thu, 30 May 2019 03:47:43 -0700 (PDT) Subject: Re: [RFC v2 1/7] arm64: cpufeature: add pointer auth meta-capabilities To: kristina.martsenko@arm.com, linux-arm-kernel@lists.infradead.org References: <20190529190332.29753-1-kristina.martsenko@arm.com> <20190529190332.29753-2-kristina.martsenko@arm.com> From: Suzuki K Poulose Message-ID: <631b3ef0-7edc-dbcb-199a-809bb8ef68d9@arm.com> Date: Thu, 30 May 2019 11:50:22 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20190529190332.29753-2-kristina.martsenko@arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190530_034748_310989_144EDC2A X-CRM114-Status: GOOD ( 17.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: mark.rutland@arm.com, keescook@chromium.org, ard.biesheuvel@linaro.org, catalin.marinas@arm.com, will.deacon@arm.com, ramana.radhakrishnan@arm.com, amit.kachhap@arm.com, dave.martin@arm.com Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Kristina, On 05/29/2019 08:03 PM, Kristina Martsenko wrote: > To enable pointer auth for the kernel, we're going to need to check for > the presence of address auth and generic auth using alternative_if. We > currently have two cpucaps for each, but alternative_if needs to check a > single cpucap. So define meta-capabilities that are present when either > of the current two capabilities is present. > > Leave the existing four cpucaps in place, as they are still needed to > check for mismatched systems where one CPU has the architected algorithm > but another has the IMP DEF algorithm. > > Note, the meta-capabilities were present before but were removed in > commits a56005d32105 ("arm64: cpufeature: Reduce number of pointer auth > CPU caps from 6 to 4") and 1e013d06120c ("arm64: cpufeature: Rework ptr > auth hwcaps using multi_entry_cap_matches"), as they were not needed > then. Note, unlike before, the current patch checks the cpucap values > directly, instead of reading the CPU ID register value. > > Signed-off-by: Kristina Martsenko This patch as such looks fine to me. However, do we really make use of the individual caps for ARCH/IMPDEF support ? Do we plan to do something about them in the future ? If not we could as well remove them and have the generic ones in place. That may be done in a separate series as a cleanup. Either way, for this patch: Reviewed-by: Suzuki K Poulose _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel