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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED,USER_AGENT_MUTT 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 5B179C65BAE for ; Thu, 13 Dec 2018 12:07:53 +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 28EB620851 for ; Thu, 13 Dec 2018 12:07:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="LVSGk46E" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 28EB620851 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-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=pNIKa/W0PPPXreuE0CkXbQ0iTxa/YGRZrouUT3TyEXs=; b=LVSGk46EEqhmeW 5wctCxItUlLx0gH7FRjBfgwXfEkzk/rSz07121+oMs4jZf6UzlLwmjUfLGp1nsRcfC5dV1u3FfIBg WLJv9/P+ppaCfFaxfJul/Ihg/1tgyYr9cc+So41tsElpKOtJozQs3Bihlo+x4N7LWeqx5HObSxC1G oOoj2lTmzBFefEc9VFRrLUhLefMDP4UqBJG0ilWBkrnUzkHm7jkVO6+4AjEyK+VVu7Ftv3KIZLMbD QhXrNe8X07iNl3FI6Ilr+K24YCzU876Gyq1xoVcKZ68hjZ8vTwGTpeMyCZiuG165Lil+G4EsmP5cJ +EP7R7Q1FUJ1KMGRheUA==; 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 1gXPmM-0007BC-RL; Thu, 13 Dec 2018 12:07:46 +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 1gXPmJ-0007AH-46 for linux-arm-kernel@lists.infradead.org; Thu, 13 Dec 2018 12:07:44 +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 AED25A78; Thu, 13 Dec 2018 04:07:32 -0800 (PST) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id E06FA3F575; Thu, 13 Dec 2018 04:07:30 -0800 (PST) Date: Thu, 13 Dec 2018 12:07:28 +0000 From: Dave Martin To: Jeremy Linton Subject: Re: [PATCH 0/6] add system vulnerability sysfs entries Message-ID: <20181213120726.GB3505@e103592.cambridge.arm.com> References: <20181206234408.1287689-1-jeremy.linton@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20181206234408.1287689-1-jeremy.linton@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20181213_040743_171272_EC00145E X-CRM114-Status: GOOD ( 16.57 ) 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, suzuki.poulose@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, shankerd@codeaurora.org, ykaukab@suse.de, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Dec 06, 2018 at 05:44:02PM -0600, Jeremy Linton wrote: > Part of this series was originally by Mian Yousaf Kaukab. > > Arm64 machines should be displaying a human readable > vulnerability status to speculative execution attacks in > /sys/devices/system/cpu/vulnerabilities Is there any agreement on the strings that will be returned in there? A quick search didn't find anything obvious upstream. There is documentation proposed in [1], but I don't know what happened to it and it doesn't define the mitigation strings at all. (I didn't follow the discussion, so there is likely background here I'm not aware of.) If the mitigation strings are meaningful at all, they really ought to be documented somewhere since this is ABI. > This series enables that behavior by providing the expected > functions. Those functions expose the cpu errata and feature > states, as well as whether firmware is responding appropriately > to display the overall machine status. This means that in a > heterogeneous machine we will only claim the machine is mitigated > or safe if we are confident all booted cores are safe or > mitigated. Otherwise, we will display unknown or unsafe > depending on how much of the machine configuration can > be assured. Can the vulnerability status change once we enter userspace? I see no locking or other concurrency protections, and various global variables that could be __ro_after_init if nothing will change them after boot. If they can change after boot, userspace has no way to be notified, (I haven't grokked the patches fully, so the answer to this question may be reasonably straightforward...) Cheers ---Dave [1] https://lkml.org/lkml/2018/1/8/145 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel