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=-5.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_DBL_ABUSE_MALW,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 84270C33CB3 for ; Tue, 28 Jan 2020 06:11:03 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 586B02467E for ; Tue, 28 Jan 2020 06:11:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="fOc+OA6B" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 586B02467E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:Date: Message-ID:References:To:From:Subject:Reply-To:Content-ID:Content-Description :Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=6IIE3n/MnSK1BhavVgw5X3ekvTv5QTY06e6aifn4ejU=; b=fOc+OA6BVIUway Dr5zYnmjpT1q+H0yZhwj4/qd7KL+9zJjrLWMMHdeaBOP3S66PhcrL4v2dpEXo9VapV4TXu52zuJ0l h3NtmGCF+C6b9a4/+cTkcwXDpriGs+aSyWc048C6wYod7R8Xl/c8I1z6Ymw/dsBBDK820tuJbS4Y4 ZfPf+eiHr8KP48GfHJ/zj/ahOweVFw6d7hKvvvN0OQnsnLHVDntu/xQWuGXwOrkEeJaGZmYig+MQw T3MxEAmw7Iroaq+yCoAl2abXIR+yNwY+WS9dPGO4pusF+QJg4kPfJZMwRTHmnmMNpOaDNwnVRej1S vkNc9rIu9q0xM7nqZEew==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iwK5R-0003TY-7N; Tue, 28 Jan 2020 06:10:57 +0000 Received: from mga06.intel.com ([134.134.136.31]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iwK5L-0003Se-PF for linux-arm-kernel@lists.infradead.org; Tue, 28 Jan 2020 06:10:55 +0000 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 27 Jan 2020 22:10:50 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,372,1574150400"; d="scan'208";a="308988573" Received: from linux.intel.com ([10.54.29.200]) by orsmga001.jf.intel.com with ESMTP; 27 Jan 2020 22:10:50 -0800 Received: from [10.252.25.124] (abudanko-mobl.ccr.corp.intel.com [10.252.25.124]) by linux.intel.com (Postfix) with ESMTP id C1EAD5803C1; Mon, 27 Jan 2020 22:10:42 -0800 (PST) Subject: [PATCH v6 05/10] drm/i915/perf: open access for CAP_PERFMON privileged process From: Alexey Budankov To: Peter Zijlstra , Arnaldo Carvalho de Melo , Ingo Molnar , "benh@kernel.crashing.org" , Paul Mackerras , Michael Ellerman , "james.bottomley@hansenpartnership.com" , Serge Hallyn , Will Deacon , Robert Richter , Alexei Starovoitov References: <74d524ab-ac11-a7b8-1052-eba10f117e09@linux.intel.com> Organization: Intel Corp. Message-ID: <2929ab4a-5f01-c078-0fcf-eb0cd306b454@linux.intel.com> Date: Tue, 28 Jan 2020 09:10:41 +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: <74d524ab-ac11-a7b8-1052-eba10f117e09@linux.intel.com> Content-Language: en-US X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200127_221054_041268_9DC0D3FD X-CRM114-Status: GOOD ( 14.87 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Song Liu , Andi Kleen , "linux-parisc@vger.kernel.org" , Alexander Shishkin , "linuxppc-dev@lists.ozlabs.org" , "intel-gfx@lists.freedesktop.org" , Igor Lubashev , linux-kernel , Stephane Eranian , "linux-perf-users@vger.kernel.org" , "selinux@vger.kernel.org" , "linux-security-module@vger.kernel.org" , oprofile-list@lists.sf.net, Lionel Landwerlin , Namhyung Kim , Jiri Olsa , linux-arm-kernel Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org Open access to i915_perf 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 i915_events subsystem remains open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for secure i915_events monitoring is discouraged with respect to CAP_PERFMON capability. 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel