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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 291E8C43387 for ; Wed, 9 Jan 2019 23:56:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 000C9214DA for ; Wed, 9 Jan 2019 23:56:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726646AbfAIXzy (ORCPT ); Wed, 9 Jan 2019 18:55:54 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:53304 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726286AbfAIXzv (ORCPT ); Wed, 9 Jan 2019 18:55:51 -0500 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 EE8C9EBD; Wed, 9 Jan 2019 15:55:50 -0800 (PST) Received: from beelzebub.austin.arm.com (beelzebub.austin.arm.com [10.118.12.119]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 019CC3F5AF; Wed, 9 Jan 2019 15:55:49 -0800 (PST) From: Jeremy Linton To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, will.deacon@arm.com, marc.zyngier@arm.com, suzuki.poulose@arm.com, dave.martin@arm.com, shankerd@codeaurora.org, linux-kernel@vger.kernel.org, ykaukab@suse.de, julien.thierry@arm.com, mlangsdo@redhat.com, steven.price@arm.com, stefan.wahren@i2se.com, Jeremy Linton , Greg Kroah-Hartman , "Rafael J . Wysocki" , Thomas Gleixner , Josh Poimboeuf , Konrad Rzeszutek Wilk , Ingo Molnar , Waiman Long , Andi Kleen , Jiri Kosina Subject: [PATCH v3 1/7] sysfs/cpu: Allow individual architectures to select vulnerabilities Date: Wed, 9 Jan 2019 17:55:38 -0600 Message-Id: <20190109235544.2992426-2-jeremy.linton@arm.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190109235544.2992426-1-jeremy.linton@arm.com> References: <20190109235544.2992426-1-jeremy.linton@arm.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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; + if (sysfs_create_group(&cpu_subsys.dev_root->kobj, &cpu_root_vulnerabilities_group)) pr_err("Unable to register CPU vulnerabilities\n"); diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 218df7f4d3e1..5e45814bcc24 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -189,4 +189,11 @@ static inline void cpu_smt_check_topology_early(void) { } static inline void cpu_smt_check_topology(void) { } #endif +/* generic cpu vulnerability attributes */ +#define VULN_MELTDOWN 0x01 +#define VULN_SPECTREV1 0x02 +#define VULN_SPECTREV2 0x04 +#define VULN_SSB 0x08 +#define VULN_L1TF 0x10 + #endif /* _LINUX_CPU_H_ */ -- 2.17.2