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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 083BFC33CAA for ; Mon, 20 Jan 2020 11:28:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC5B4207E0 for ; Mon, 20 Jan 2020 11:28:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727066AbgATL2g (ORCPT ); Mon, 20 Jan 2020 06:28:36 -0500 Received: from mga11.intel.com ([192.55.52.93]:2093 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726590AbgATL2f (ORCPT ); Mon, 20 Jan 2020 06:28:35 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Jan 2020 03:28:35 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,341,1574150400"; d="scan'208";a="425168570" Received: from linux.intel.com ([10.54.29.200]) by fmsmga005.fm.intel.com with ESMTP; 20 Jan 2020 03:28:34 -0800 Received: from [10.125.252.193] (abudanko-mobl.ccr.corp.intel.com [10.125.252.193]) by linux.intel.com (Postfix) with ESMTP id 20D515803C5; Mon, 20 Jan 2020 03:28:25 -0800 (PST) Subject: [PATCH v5 05/10] drm/i915/perf: open access for CAP_PERFMON privileged process From: Alexey Budankov To: Peter Zijlstra , Arnaldo Carvalho de Melo , Ingo Molnar , "jani.nikula@linux.intel.com" , "joonas.lahtinen@linux.intel.com" , "rodrigo.vivi@intel.com" , "benh@kernel.crashing.org" , Paul Mackerras , Michael Ellerman , "james.bottomley@hansenpartnership.com" , Serge Hallyn , James Morris , Will Deacon , Mark Rutland , Robert Richter , Alexei Starovoitov Cc: Jiri Olsa , Andi Kleen , Stephane Eranian , Igor Lubashev , Alexander Shishkin , Namhyung Kim , Song Liu , Lionel Landwerlin , Thomas Gleixner , linux-kernel , "linux-security-module@vger.kernel.org" , "selinux@vger.kernel.org" , "intel-gfx@lists.freedesktop.org" , "linux-parisc@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , linux-arm-kernel@lists.infradead.org, "linux-perf-users@vger.kernel.org" , oprofile-list@lists.sf.net References: <0548c832-7f4b-dc4c-8883-3f2b6d351a08@linux.intel.com> Organization: Intel Corp. Message-ID: Date: Mon, 20 Jan 2020 14:28:24 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <0548c832-7f4b-dc4c-8883-3f2b6d351a08@linux.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Open access to i915_perf monitoring for CAP_PERFMON privileged processes. For backward compatibility reasons access to i915_perf subsystem remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure i915_perf monitoring is discouraged with respect to CAP_PERFMON capability. Providing the access under CAP_PERFMON capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes chances to misuse the credentials and makes operations more secure. Signed-off-by: Alexey Budankov --- drivers/gpu/drm/i915/i915_perf.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index 2ae14bc14931..d89347861b7d 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -3375,10 +3375,10 @@ i915_perf_open_ioctl_locked(struct i915_perf *perf, /* Similar to perf's kernel.perf_paranoid_cpu sysctl option * we check a dev.i915.perf_stream_paranoid sysctl option * to determine if it's ok to access system wide OA counters - * without CAP_SYS_ADMIN privileges. + * without CAP_PERFMON or CAP_SYS_ADMIN privileges. */ if (privileged_op && - i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) { + i915_perf_stream_paranoid && !perfmon_capable()) { DRM_DEBUG("Insufficient privileges to open i915 perf stream\n"); ret = -EACCES; goto err_ctx; @@ -3571,9 +3571,8 @@ static int read_properties_unlocked(struct i915_perf *perf, } else oa_freq_hz = 0; - if (oa_freq_hz > i915_oa_max_sample_rate && - !capable(CAP_SYS_ADMIN)) { - DRM_DEBUG("OA exponent would exceed the max sampling frequency (sysctl dev.i915.oa_max_sample_rate) %uHz without root privileges\n", + if (oa_freq_hz > i915_oa_max_sample_rate && !perfmon_capable()) { + DRM_DEBUG("OA exponent would exceed the max sampling frequency (sysctl dev.i915.oa_max_sample_rate) %uHz without CAP_PERFMON or CAP_SYS_ADMIN privileges\n", i915_oa_max_sample_rate); return -EACCES; } @@ -3994,7 +3993,7 @@ int i915_perf_add_config_ioctl(struct drm_device *dev, void *data, return -EINVAL; } - if (i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) { + if (i915_perf_stream_paranoid && !perfmon_capable()) { DRM_DEBUG("Insufficient privileges to add i915 OA config\n"); return -EACCES; } @@ -4141,7 +4140,7 @@ int i915_perf_remove_config_ioctl(struct drm_device *dev, void *data, return -ENOTSUPP; } - if (i915_perf_stream_paranoid && !capable(CAP_SYS_ADMIN)) { + if (i915_perf_stream_paranoid && !perfmon_capable()) { DRM_DEBUG("Insufficient privileges to remove i915 OA config\n"); return -EACCES; } -- 2.20.1