From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753239AbdBNMcY (ORCPT ); Tue, 14 Feb 2017 07:32:24 -0500 Received: from forwardcorp1h.cmail.yandex.net ([87.250.230.216]:46121 "EHLO forwardcorp1h.cmail.yandex.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752113AbdBNMbw (ORCPT ); Tue, 14 Feb 2017 07:31:52 -0500 Authentication-Results: smtpcorp1o.mail.yandex.net; dkim=pass header.i=@yandex-team.ru Subject: [PATCH] perf: fix documentation of sysctls perf_event_paranoid and perf_event_mlock_kb From: Konstantin Khlebnikov To: Arnaldo Carvalho de Melo Cc: Jonathan Corbet , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Date: Tue, 14 Feb 2017 15:31:44 +0300 Message-ID: <148707550439.232450.16020152081288633254.stgit@buzz> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Fix misprint CAP_IOC_LOCK -> CAP_IPC_LOCK. This capability have nothing to do with raw tracepoints. This part is about bypassing mlock limits. Sysctl kernel.perf_event_paranoid = -1 allows raw and ftrace function tracepoints without CAP_SYS_ADMIN. Signed-off-by: Konstantin Khlebnikov --- Documentation/sysctl/kernel.txt | 13 ++++++++++++- tools/perf/util/evsel.c | 4 +++- 2 files changed, 15 insertions(+), 2 deletions(-) diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index a32b4b748644..f1272ff1fcb5 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -61,6 +61,7 @@ show up in /proc/sys/kernel: - perf_cpu_time_max_percent - perf_event_paranoid - perf_event_max_stack +- perf_event_mlock_kb - perf_event_max_contexts_per_stack - pid_max - powersave-nap [ PPC only ] @@ -654,7 +655,9 @@ Controls use of the performance events system by unprivileged users (without CAP_SYS_ADMIN). The default value is 2. -1: Allow use of (almost) all events by all users ->=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK + Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK +>=0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN + Disallow raw tracepoint access by users without CAP_SYS_ADMIN >=1: Disallow CPU event access by users without CAP_SYS_ADMIN >=2: Disallow kernel profiling by users without CAP_SYS_ADMIN @@ -673,6 +676,14 @@ The default value is 127. ============================================================== +perf_event_mlock_kb: + +Control size of per-cpu ring buffer not counted agains mlock limit. + +The default value is 512 + 1 page + +============================================================== + perf_event_max_contexts_per_stack: Controls maximum number of stack frame context entries for diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 04e536ae4d88..9932de565aa7 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2467,7 +2467,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, "unprivileged users (without CAP_SYS_ADMIN).\n\n" "The current value is %d:\n\n" " -1: Allow use of (almost) all events by all users\n" - ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n" + " Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n" + ">= 0: Disallow ftrace function tracepoint by users without CAP_SYS_ADMIN\n" + " Disallow raw tracepoint access by users without CAP_SYS_ADMIN\n" ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n" ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN", target->system_wide ? "system-wide " : "",