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 A929FC2D0C1 for ; Thu, 19 Dec 2019 09:10:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8990C24680 for ; Thu, 19 Dec 2019 09:10:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726730AbfLSJKk (ORCPT ); Thu, 19 Dec 2019 04:10:40 -0500 Received: from mga09.intel.com ([134.134.136.24]:19859 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726719AbfLSJKk (ORCPT ); Thu, 19 Dec 2019 04:10:40 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by orsmga102.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Dec 2019 01:10:39 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,331,1571727600"; d="scan'208";a="212954494" Received: from bbartede-mobl2.ger.corp.intel.com (HELO [10.252.33.233]) ([10.252.33.233]) by fmsmga007.fm.intel.com with ESMTP; 19 Dec 2019 01:10:30 -0800 Subject: Re: [PATCH v4 4/9] drm/i915/perf: open access for CAP_SYS_PERFMON privileged process To: Alexey Budankov , Peter Zijlstra , Arnaldo Carvalho de Melo , Ingo Molnar , "jani.nikula@linux.intel.com" , "joonas.lahtinen@linux.intel.com" , "rodrigo.vivi@intel.com" , Alexei Starovoitov , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , "james.bottomley@hansenpartnership.com" , Serge Hallyn , James Morris , Will Deacon , Mark Rutland , Casey Schaufler , Robert Richter Cc: Jiri Olsa , Andi Kleen , Stephane Eranian , Igor Lubashev , Alexander Shishkin , Namhyung Kim , Kees Cook , Jann Horn , Thomas Gleixner , Tvrtko Ursulin , Song Liu , linux-kernel , "linux-security-module@vger.kernel.org" , "selinux@vger.kernel.org" , "intel-gfx@lists.freedesktop.org" , "bpf@vger.kernel.org" , "linux-parisc@vger.kernel.org" , "linuxppc-dev@lists.ozlabs.org" , "linux-perf-users@vger.kernel.org" , linux-arm-kernel@lists.infradead.org, oprofile-list@lists.sf.net References: From: Lionel Landwerlin Organization: Intel Corporation (UK) Ltd. - Co. Reg. #1134945 - Pipers Way, Swindon SN3 1RJ Message-ID: Date: Thu, 19 Dec 2019 11:10:29 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On 18/12/2019 11:27, Alexey Budankov wrote: > Open access to i915_perf monitoring for CAP_SYS_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_SYS_PERFMON capability. > > Signed-off-by: Alexey Budankov Acked-by: Lionel Landwerlin > --- > 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 e42b86827d6b..e2697f8d04de 100644 > --- a/drivers/gpu/drm/i915/i915_perf.c > +++ b/drivers/gpu/drm/i915/i915_perf.c > @@ -2748,10 +2748,10 @@ i915_perf_open_ioctl_locked(struct drm_i915_private *dev_priv, > /* 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_SYS_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 system-wide i915 perf stream\n"); > ret = -EACCES; > goto err_ctx; > @@ -2939,9 +2939,8 @@ static int read_properties_unlocked(struct drm_i915_private *dev_priv, > } 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_SYS_PERFMON or CAP_SYS_ADMIN privileges\n", > i915_oa_max_sample_rate); > return -EACCES; > } > @@ -3328,7 +3327,7 @@ 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; > } > @@ -3474,7 +3473,7 @@ 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; > }