From patchwork Wed Feb 5 17:35:45 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Budankov X-Patchwork-Id: 11366797 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 2447092A for ; Wed, 5 Feb 2020 17:35:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0C4DE21927 for ; Wed, 5 Feb 2020 17:35:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727305AbgBERfz (ORCPT ); Wed, 5 Feb 2020 12:35:55 -0500 Received: from mga14.intel.com ([192.55.52.115]:16885 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726957AbgBERfz (ORCPT ); Wed, 5 Feb 2020 12:35:55 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Feb 2020 09:35:54 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,406,1574150400"; d="scan'208";a="404218446" Received: from linux.intel.com ([10.54.29.200]) by orsmga005.jf.intel.com with ESMTP; 05 Feb 2020 09:35:54 -0800 Received: from [10.252.5.149] (abudanko-mobl.ccr.corp.intel.com [10.252.5.149]) by linux.intel.com (Postfix) with ESMTP id 919B05802BC; Wed, 5 Feb 2020 09:35:46 -0800 (PST) Subject: [PATCH v6 08/10] 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 , Michael Ellerman Cc: Andi Kleen , Thomas Gleixner , 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 References: <576a6141-36d4-14c0-b395-8d195892b916@linux.intel.com> Organization: Intel Corp. Message-ID: <15e3133b-3090-f7e4-f12d-f47c60f8c93d@linux.intel.com> Date: Wed, 5 Feb 2020 20:35:45 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: <576a6141-36d4-14c0-b395-8d195892b916@linux.intel.com> 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 --- 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 676683641d00..c4208d027794 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))