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=-9.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 ADE2DC433DB for ; Mon, 11 Jan 2021 13:42:37 +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 7A13C221EC for ; Mon, 11 Jan 2021 13:42:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7A13C221EC Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org 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-Type: Content-Transfer-Encoding:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:Message-ID:References:In-Reply-To:Subject:To:From: Date:MIME-Version:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=h1IHvrZuhHvKhvc2NRKZmddl8aDXxfpT9bFu5sKNjLA=; b=0lkApR1vNuPbJIKM/YSGW5jzG 1T5wyfZ6UXRzMNmeeN26vP/GdScQwrdGI9t2FvIfdfy3gep1QDhu0OJvnsYCjyAxp315DNpKqgYw2 5x/Qhh/WZnPnVZJLMh8L18aoobrysq+JR/wkAd8j24jLLJyE4vAqIw4vG6kqjUB9LRO5ncdcVfOTI hg43vG5Uyk5OwNED4lZW2gsYn8Atx82X7RXVf2VBvenP4sHz6K3WDSc03gdIdGu8q40TfVL/xGtIR /UxR9/nBJxQ/voJl3cRt0GuVI8n5YTHqe8zvY3DWNxkuj2yQBuPSrkqX8TvbC2kDQ7km9wJ5bM3oX rpROqhffw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kyxRb-000835-GH; Mon, 11 Jan 2021 13:41:15 +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 1kyxRD-0007oe-Le for linux-arm-kernel@lists.infradead.org; Mon, 11 Jan 2021 13:40:55 +0000 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (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 9137D221FD; Mon, 11 Jan 2021 13:40:50 +0000 (UTC) Received: from disco-boy.misterjones.org ([51.254.78.96] helo=www.loen.fr) by disco-boy.misterjones.org with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94) (envelope-from ) id 1kyxRA-006gvt-Gn; Mon, 11 Jan 2021 13:40:48 +0000 MIME-Version: 1.0 Date: Mon, 11 Jan 2021 13:40:48 +0000 From: Marc Zyngier To: Srinivas Ramana Subject: Re: [PATCH 0/3] arm64: cpufeature: Add filter function to control In-Reply-To: <1610152163-16554-1-git-send-email-sramana@codeaurora.org> References: <1610152163-16554-1-git-send-email-sramana@codeaurora.org> User-Agent: Roundcube Webmail/1.4.9 Message-ID: <6dfdf691b5ed57df81c4c61422949af5@misterjones.org> X-Sender: maz@kernel.org X-SA-Exim-Connect-IP: 51.254.78.96 X-SA-Exim-Rcpt-To: sramana@codeaurora.org, catalin.marinas@arm.com, will@kernel.org, pajay@qti.qualcomm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-msm@vger.kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210111_084054_254707_59729852 X-CRM114-Status: GOOD ( 18.41 ) 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-doc@vger.kernel.org, catalin.marinas@arm.com, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, pajay@qti.qualcomm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Srinivas, On 2021-01-09 00:29, Srinivas Ramana wrote: > This patchset adds a control function for cpufeature framework > so that the feature can be controlled at runtime. > > Defer PAC on boot core and use the filter function added to disable > PAC from command line. This will help toggling the feature on systems > that do not support PAC or where PAC needs to be disabled at runtime, > without modifying the core kernel. > > The idea of adding the filter function for cpufeature is taken from > https://lore.kernel.org/linux-arm-kernel/20200515171612.1020-25-catalin.marinas@arm.com/ > https://lore.kernel.org/linux-arm-kernel/20200515171612.1020-24-catalin.marinas@arm.com/ > > Srinivas Ramana (3): > arm64: Defer enabling pointer authentication on boot core > arm64: cpufeature: Add a filter function to cpufeature > arm64: Enable control of pointer authentication using early param > > Documentation/admin-guide/kernel-parameters.txt | 6 +++ > arch/arm64/include/asm/cpufeature.h | 8 +++- > arch/arm64/include/asm/pointer_auth.h | 10 +++++ > arch/arm64/include/asm/stackprotector.h | 1 + > arch/arm64/kernel/cpufeature.c | 53 > +++++++++++++++++++------ > arch/arm64/kernel/head.S | 4 -- > 6 files changed, 64 insertions(+), 18 deletions(-) I've been working for some time on a similar series to allow a feature set to be disabled during the early boot phase, initially to prevent booting a kernel with VHE, but the mechanism is generic enough to deal with most architectural features. I took the liberty to lift your first patch and to add it to my series[1], further allowing PAuth to be disabled at boot time on top of BTI and VHE. I'd appreciate your comments on this. Thanks, M. [1] https://lore.kernel.org/r/20210111132811.2455113-1-maz@kernel.org -- Jazz is not dead. It just smells funny... _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel