From patchwork Mon Feb 17 08:10:54 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Budankov X-Patchwork-Id: 11385605 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F18351820 for ; Mon, 17 Feb 2020 08:11:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC8A920725 for ; Mon, 17 Feb 2020 08:11:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727545AbgBQILC (ORCPT ); Mon, 17 Feb 2020 03:11:02 -0500 Received: from mga06.intel.com ([134.134.136.31]:5788 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726932AbgBQILC (ORCPT ); Mon, 17 Feb 2020 03:11:02 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Feb 2020 00:11:01 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,451,1574150400"; d="scan'208";a="382108423" Received: from linux.intel.com ([10.54.29.200]) by orsmga004.jf.intel.com with ESMTP; 17 Feb 2020 00:11:01 -0800 Received: from [10.125.252.180] (abudanko-mobl.ccr.corp.intel.com [10.125.252.180]) by linux.intel.com (Postfix) with ESMTP id 71F155804A2; Mon, 17 Feb 2020 00:10:55 -0800 (PST) Subject: [PATCH v7 08/12] parisc/perf: open access for CAP_PERFMON privileged process From: Alexey Budankov To: James Morris , Serge Hallyn , Stephen Smalley , Peter Zijlstra , Arnaldo Carvalho de Melo , Ingo Molnar , "joonas.lahtinen@linux.intel.com" , Alexei Starovoitov , Will Deacon , Paul Mackerras , Helge Deller , Thomas Gleixner Cc: Andi Kleen , Stephane Eranian , Igor Lubashev , Jiri Olsa , linux-kernel , "intel-gfx@lists.freedesktop.org" , "linux-security-module@vger.kernel.org" , "selinux@vger.kernel.org" , linux-arm-kernel , "linuxppc-dev@lists.ozlabs.org" , "linux-parisc@vger.kernel.org" , oprofile-list@lists.sf.net, "linux-doc@vger.kernel.org" , linux-man@vger.kernel.org References: Organization: Intel Corp. Message-ID: <29e45605-7a3c-944b-7bea-5959f8ff0793@linux.intel.com> Date: Mon, 17 Feb 2020 11:10:54 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org Open access to monitoring for CAP_PERFMON privileged process. Providing the access under CAP_PERFMON capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes chances to misuse the credentials and makes operation more secure. CAP_PERFMON implements the principal of least privilege for performance monitoring and observability operations (POSIX IEEE 1003.1e 2.2.2.39 principle of least privilege: A security design principle that states that a process or program be granted only those privileges (e.g., capabilities) necessary to accomplish its legitimate function, and only for the time that such privileges are actually required) For backward compatibility reasons access to the monitoring remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure monitoring is discouraged with respect to CAP_PERFMON capability. Signed-off-by: Alexey Budankov Reviewed-by: James Morris --- arch/parisc/kernel/perf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/parisc/kernel/perf.c b/arch/parisc/kernel/perf.c index e1a8fee3ad49..d46b6709ec56 100644 --- a/arch/parisc/kernel/perf.c +++ b/arch/parisc/kernel/perf.c @@ -300,7 +300,7 @@ static ssize_t perf_write(struct file *file, const char __user *buf, else return -EFAULT; - if (!capable(CAP_SYS_ADMIN)) + if (!perfmon_capable()) return -EACCES; if (count != sizeof(uint32_t))