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=-5.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 E6A42C33CB3 for ; Tue, 28 Jan 2020 21:19:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C52762465B for ; Tue, 28 Jan 2020 21:19:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726389AbgA1VT3 (ORCPT ); Tue, 28 Jan 2020 16:19:29 -0500 Received: from namei.org ([65.99.196.166]:60444 "EHLO namei.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726257AbgA1VT2 (ORCPT ); Tue, 28 Jan 2020 16:19:28 -0500 Received: from localhost (localhost [127.0.0.1]) by namei.org (8.14.4/8.14.4) with ESMTP id 00SLGe9n004527; Tue, 28 Jan 2020 21:16:40 GMT Date: Wed, 29 Jan 2020 08:16:40 +1100 (AEDT) From: James Morris To: Alexey Budankov cc: 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 , "intel-gfx@lists.freedesktop.org" , Jiri Olsa , Andi Kleen , Stephane Eranian , Igor Lubashev , Alexander Shishkin , Namhyung Kim , Song Liu , Lionel Landwerlin , linux-kernel , "linux-security-module@vger.kernel.org" , "selinux@vger.kernel.org" , linux-arm-kernel , "linuxppc-dev@lists.ozlabs.org" , "linux-parisc@vger.kernel.org" , "linux-perf-users@vger.kernel.org" , oprofile-list@lists.sf.net Subject: Re: [PATCH v6 03/10] perf/core: open access to probes for CAP_PERFMON privileged process In-Reply-To: <6cdc10f2-31e5-6d71-7d71-c6b5250b74f1@linux.intel.com> Message-ID: References: <74d524ab-ac11-a7b8-1052-eba10f117e09@linux.intel.com> <6cdc10f2-31e5-6d71-7d71-c6b5250b74f1@linux.intel.com> User-Agent: Alpine 2.21 (LRH 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-parisc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On Tue, 28 Jan 2020, Alexey Budankov wrote: > > Open access to monitoring via kprobes and uprobes and eBPF tracing 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. > > perf kprobes and uprobes are used by ftrace and eBPF. perf probe uses > ftrace to define new kprobe events, and those events are treated as > tracepoint events. eBPF defines new probes via perf_event_open interface > and then the probes are used in eBPF tracing. > > 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 perf_events subsystem remains > open for CAP_SYS_ADMIN privileged processes but CAP_SYS_ADMIN usage for > secure perf_events monitoring is discouraged with respect to CAP_PERFMON > capability. > > Signed-off-by: Alexey Budankov > --- > kernel/events/core.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Acked-by: James Morris -- James Morris