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=-8.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 F381FC43387 for ; Fri, 18 Jan 2019 16:31:10 +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 C02AF20883 for ; Fri, 18 Jan 2019 16:31:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="kjkf9iiD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C02AF20883 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=jUZUVpYTyh2qSHxwmysTobp+MaRDjsjW1zytL/XsRhQ=; b=kjkf9iiDhURVgx429P4F2GtWB xynpPX9iN+Qw1Xyf4GL+Ok1yj1NUE7a4Oi30Wu1lxDIw98b8DGtloMO+kcA8/Q7Eu/e6frpKQ4OkT YobpmDb36Kxhic6G1O8mdG/uVTiemAXajkLilO+Ub1sHSeDDxu74wKiiUMR5FPV7SCTlRN6rm5i6h QCYoMTk4FnLq4A55paseWGk3Oo8wfInSNF95oHV/dwjs2Ozf2rvPTgOMJjhqobG7UzYWqnt3hpzya BiSXwGS2mu48hwZl1E2XW1v1CvtNLtL7OBRhUYDJrFLIssgImh/lhsTNsmaBv5kjX6AfKrTn94Vwh ZBmk6lY7g==; 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 1gkX2x-0002x4-At; Fri, 18 Jan 2019 16:31:07 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gkX2t-0002wK-NI for linux-arm-kernel@lists.infradead.org; Fri, 18 Jan 2019 16:31:05 +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 0BB4BEBD; Fri, 18 Jan 2019 08:31:02 -0800 (PST) Received: from [192.168.100.241] (usa-sjc-mx-foss1.foss.arm.com [217.140.101.70]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C0E593F557; Fri, 18 Jan 2019 08:31:00 -0800 (PST) Subject: Re: [PATCH v3 1/7] sysfs/cpu: Allow individual architectures to select vulnerabilities To: Greg KH , Suzuki K Poulose References: <20190109235544.2992426-1-jeremy.linton@arm.com> <20190109235544.2992426-2-jeremy.linton@arm.com> <901f2f29-aa06-13ad-1995-f9f22184e39d@arm.com> <20190118154637.GA8564@kroah.com> From: Jeremy Linton Message-ID: <988ddbc9-ae46-22cc-4228-5f1ea98605c1@arm.com> Date: Fri, 18 Jan 2019 10:31:00 -0600 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: <20190118154637.GA8564@kroah.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190118_083103_770388_6C2E2583 X-CRM114-Status: GOOD ( 21.20 ) 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: stefan.wahren@i2se.com, mlangsdo@redhat.com, jkosina@suse.cz, konrad.wilk@oracle.com, julien.thierry@arm.com, marc.zyngier@arm.com, catalin.marinas@arm.com, rafael@kernel.org, will.deacon@arm.com, linux-kernel@vger.kernel.org, Steven.Price@arm.com, ak@linux.intel.com, mingo@kernel.org, shankerd@codeaurora.org, jpoimboe@redhat.com, ykaukab@suse.de, longman@redhat.com, tglx@linutronix.de, dave.martin@arm.com, 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+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On 01/18/2019 09:46 AM, Greg KH wrote: > On Mon, Jan 14, 2019 at 10:02:21AM +0000, Suzuki K Poulose wrote: >> >> >> On 09/01/2019 23:55, Jeremy Linton wrote: >>> As suggested on the list, https://lkml.org/lkml/2019/1/4/282, there are >>> a number of cases where its useful for a system to avoid exporting a >>> sysfs entry for a given vulnerability. This set adds an architecture >>> specific callback which returns the bitmap of vulnerabilities the >>> architecture would like to advertise. >>> >>> Signed-off-by: Jeremy Linton >>> Cc: Greg Kroah-Hartman >>> Cc: Rafael J. Wysocki >>> Cc: Thomas Gleixner >>> Cc: Josh Poimboeuf >>> Cc: Konrad Rzeszutek Wilk >>> Cc: Ingo Molnar >>> Cc: Waiman Long >>> Cc: Andi Kleen >>> Cc: Jiri Kosina >>> --- >>> drivers/base/cpu.c | 19 +++++++++++++++++++ >>> include/linux/cpu.h | 7 +++++++ >>> 2 files changed, 26 insertions(+) >>> >>> diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c >>> index eb9443d5bae1..35f6dfb24cd6 100644 >>> --- a/drivers/base/cpu.c >>> +++ b/drivers/base/cpu.c >>> @@ -561,6 +561,11 @@ static struct attribute *cpu_root_vulnerabilities_attrs[] = { >>> NULL >>> }; >>> +uint __weak arch_supported_vuln_attr_fields(void) >>> +{ >>> + return VULN_MELTDOWN|VULN_SPECTREV1|VULN_SPECTREV2|VULN_SSB|VULN_L1TF; >>> +} >>> + >>> static const struct attribute_group cpu_root_vulnerabilities_group = { >>> .name = "vulnerabilities", >>> .attrs = cpu_root_vulnerabilities_attrs, >>> @@ -568,6 +573,20 @@ static const struct attribute_group cpu_root_vulnerabilities_group = { >>> static void __init cpu_register_vulnerabilities(void) >>> { >>> + int fld; >>> + int max_fields = ARRAY_SIZE(cpu_root_vulnerabilities_attrs) - 1; >>> + struct attribute **hd = cpu_root_vulnerabilities_attrs; >>> + uint enabled_fields = arch_supported_vuln_attr_fields(); >>> + >>> + /* only enable entries requested by the arch code */ >>> + for (fld = 0; fld < max_fields; fld++) { >>> + if (enabled_fields & 1 << fld) { >>> + *hd = cpu_root_vulnerabilities_attrs[fld]; >>> + hd++; >>> + } >>> + } >>> + *hd = NULL; >>> + >> >> nit: Could we use "is_visible" callback in the attribute group to check this >> dynamically ? > > You should, that is what it is there for. Yes, its a good suggestion. OTOH, I think the plan is to drop this functionality all together by removing the ability to build kernels without the vulnerability checking/processor white lists. That will simplify some of the #ifdef'ing going on as well. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel