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=-5.2 required=3.0 tests=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 B55A5FA372A for ; Thu, 17 Oct 2019 14:07:16 +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 818722054F for ; Thu, 17 Oct 2019 14:07:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="lesl5XJk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 818722054F 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=6mGnKN0jtYvlUGw5isggc6GJOBrH3c5bt1qsy+CVzK8=; b=lesl5XJke5iFtbXrhoRV7nPea OtVKgGrRHpqEXmNLQhKvTUKQzrcq9vItq4AjzNpKELWN7TvMMeEaHT9lJ+8rnLG37KOvU8ugd61W0 fSGNWooztM/SJfeU9csweVsm7kLCZy5UwlXorsibymBXLydLgbrXW4ge0fU0ae8nYWfFGloK3LcxE 4LP4gv5/JmMkR7NRjfGINxji8GjBUCxHs/5T4O72ht19YxqBfUcI0Aft0kFQR/SkLKKlzAIF6Enln q6q9sAExYVGXIqg3EaNtkoV6EZCKnktSBagdU6WVWh2DDinGtw9B2q6YGoNF7pObzrYx4tAFMwL36 2oYvwtJRA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iL6Qm-0003kJ-ON; Thu, 17 Oct 2019 14:07:08 +0000 Received: from [217.140.110.172] (helo=foss.arm.com) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iL6Qj-0003j8-W7 for linux-arm-kernel@lists.infradead.org; Thu, 17 Oct 2019 14:07:07 +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 2CC121993; Thu, 17 Oct 2019 07:06:55 -0700 (PDT) Received: from dawn-kernel.cambridge.arm.com (unknown [10.1.197.116]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id AFFDC3F6C4; Thu, 17 Oct 2019 07:06:53 -0700 (PDT) Subject: Re: [PATCH 03/11] arm64: cpufeature: handle conflicts based on capability To: Amit Daniel Kachhap , linux-arm-kernel@lists.infradead.org References: <1571300065-10236-1-git-send-email-amit.kachhap@arm.com> <1571300065-10236-4-git-send-email-amit.kachhap@arm.com> From: Suzuki K Poulose Message-ID: Date: Thu, 17 Oct 2019 15:06:52 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <1571300065-10236-4-git-send-email-amit.kachhap@arm.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191017_070706_079460_3BCEA54D X-CRM114-Status: GOOD ( 18.08 ) 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: Mark Rutland , Kees Cook , Ard Biesheuvel , Catalin Marinas , Will Deacon , Kristina Martsenko , James Morse , Ramana Radhakrishnan , Vincenzo Frascino , Dave Martin 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 Amit, On 17/10/2019 09:14, Amit Daniel Kachhap wrote: > From: Kristina Martsenko > > Each system capability can be of either boot, local, or system scope, > depending on when the state of the capability is finalized. When we > detect a conflict on a late CPU, we either offline the CPU or panic the > system. We currently always panic if the conflict is caused by a boot > scope capability, and offline the CPU if the conflict is caused by a > local or system scope capability. > > We're going to want to add a new capability (for pointer authentication) > which needs to be boot scope but doesn't need to panic the system when a > conflict is detected. So add a new flag to specify whether the > capability requires the system to panic or not. Current boot scope > capabilities are updated to set the flag, so there should be no > functional change as a result of this patch. > > Reviewed-by: Kees Cook > Reviewed-by: Suzuki K Poulose > Signed-off-by: Kristina Martsenko > Signed-off-by: Amit Daniel Kachhap > --- With the early parking of the CPUs without ptr_auth, I believe this change is not needed, as long as we use ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU flag for the ptr_auth capability. Moreover, we may want to retain the "panic" situation, as we don't expect a secondary CPU to turn up without the ptr_auth and have a "conflict". Cheers Suzuki _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel