From patchwork Mon Jan 20 11:32:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexey Budankov X-Patchwork-Id: 11341863 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 AFAE0921 for ; Mon, 20 Jan 2020 11:33:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9848420882 for ; Mon, 20 Jan 2020 11:33:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726897AbgATLc5 (ORCPT ); Mon, 20 Jan 2020 06:32:57 -0500 Received: from mga05.intel.com ([192.55.52.43]:59982 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726752AbgATLc4 (ORCPT ); Mon, 20 Jan 2020 06:32:56 -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 fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 20 Jan 2020 03:32:56 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,341,1574150400"; d="scan'208";a="399348452" Received: from linux.intel.com ([10.54.29.200]) by orsmga005.jf.intel.com with ESMTP; 20 Jan 2020 03:32:55 -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 DE8365803C5; Mon, 20 Jan 2020 03:32:47 -0800 (PST) Subject: [PATCH v5 09/10] drivers/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 14:32:46 +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-Language: en-US Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Open access to monitoring for CAP_PERFMON privileged processes. 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. Providing the access under CAP_PERFMON capability singly, without the rest of CAP_SYS_ADMIN credentials, excludes chances to misuse the credentials and makes the operations more secure. Signed-off-by: Alexey Budankov --- drivers/perf/arm_spe_pmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c index 4e4984a55cd1..5dff81bc3324 100644 --- a/drivers/perf/arm_spe_pmu.c +++ b/drivers/perf/arm_spe_pmu.c @@ -274,7 +274,7 @@ static u64 arm_spe_event_to_pmscr(struct perf_event *event) if (!attr->exclude_kernel) reg |= BIT(SYS_PMSCR_EL1_E1SPE_SHIFT); - if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && capable(CAP_SYS_ADMIN)) + if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && perfmon_capable()) reg |= BIT(SYS_PMSCR_EL1_CX_SHIFT); return reg; @@ -700,7 +700,7 @@ static int arm_spe_pmu_event_init(struct perf_event *event) return -EOPNOTSUPP; reg = arm_spe_event_to_pmscr(event); - if (!capable(CAP_SYS_ADMIN) && + if (!perfmon_capable() && (reg & (BIT(SYS_PMSCR_EL1_PA_SHIFT) | BIT(SYS_PMSCR_EL1_CX_SHIFT) | BIT(SYS_PMSCR_EL1_PCT_SHIFT))))