From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ben Hutchings <ben@decadent.org.uk>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@redhat.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH RESEND] perf: Document the perf sysctls
Date: Thu, 21 Jan 2016 11:25:54 -0300 [thread overview]
Message-ID: <20160121142554.GC2312@kernel.org> (raw)
In-Reply-To: <20160119213515.GG2637@decadent.org.uk>
Em Tue, Jan 19, 2016 at 09:35:15PM +0000, Ben Hutchings escreveu:
> perf_event_paranoid was only documented in source code and a perf
> error message. Move the documentation from the error message to
> Documentation/sysctl/kernel.txt.
>
> perf_cpu_time_max_percent was already documented but missing from the
> list at the top, so add it there.
>
> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
> ---
> Documentation/sysctl/kernel.txt | 13 +++++++++++++
> tools/perf/util/evsel.c | 7 ++-----
> 2 files changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
> index af70d15..88a2c8e 100644
> --- a/Documentation/sysctl/kernel.txt
> +++ b/Documentation/sysctl/kernel.txt
> @@ -58,6 +58,8 @@ show up in /proc/sys/kernel:
> - panic_on_stackoverflow
> - panic_on_unrecovered_nmi
> - panic_on_warn
> +- perf_cpu_time_max_percent
> +- perf_event_paranoid
> - pid_max
> - powersave-nap [ PPC only ]
> - printk
> @@ -624,6 +626,17 @@ allowed to execute.
>
> ==============================================================
>
> +perf_event_paranoid:
> +
> +Controls use of the performance events system by unprivileged
> +users (without CAP_SYS_ADMIN). The default value is 1.
> +
> + -1: Allow use of (almost) all events by all users
> +>=0: Disallow raw tracepoint access by users without CAP_IOC_LOCK
> +>=1: Disallow CPU event access by users without CAP_SYS_ADMIN
> +>=2: Disallow kernel profiling by users without CAP_SYS_ADMIN
> +
> +==============================================================
>
> pid_max:
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 397fb4e..9b4df11 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2314,11 +2314,8 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target,
> case EACCES:
> return scnprintf(msg, size,
> "You may not have permission to collect %sstats.\n"
> - "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n"
> - " -1 - Not paranoid at all\n"
> - " 0 - Disallow raw tracepoint access for unpriv\n"
> - " 1 - Disallow cpu events for unpriv\n"
> - " 2 - Disallow kernel profiling for unpriv",
> + "Consider tweaking /proc/sys/kernel/perf_event_paranoid -\n"
> + "see Documentation/sysctl/kernel.txt",
> target->system_wide ? "system-wide " : "");
Don't remove readily available information by a reference to a not
always available file, I'm just synching this with the doc text you
added to that Documentation file.
- Arnaldo
> case ENOENT:
> return scnprintf(msg, size, "The %s event is not supported.",
>
next prev parent reply other threads:[~2016-01-21 14:26 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-11 15:19 [PATCH 0/2] Document and extend kernel.perf_event_paranoid Ben Hutchings
2016-01-11 15:21 ` [PATCH 1/2] Documentation,perf: Document the perf sysctls Ben Hutchings
2016-01-11 15:23 ` [PATCH 2/2] security,perf: Allow further restriction of perf_event_open Ben Hutchings
2016-04-13 16:12 ` [kernel-hardening] " Kees Cook
2016-06-04 20:56 ` Jeffrey Vander Stoep
[not found] ` <CABXk95BE3wpgq-Y08G+Z3ZJbxJwgiuVvtQGaV4n-tD6GKNiFKg@mail.gmail.com>
2016-06-16 22:27 ` Kees Cook
2016-06-17 6:54 ` Peter Zijlstra
2016-06-17 16:16 ` Daniel Micay
2016-06-17 20:00 ` Arnaldo Carvalho de Melo
2016-06-18 0:51 ` Daniel Micay
2016-06-17 5:56 ` Alexander Shishkin
2016-06-17 12:18 ` Ben Hutchings
2016-06-17 15:24 ` [kernel-hardening] " Daniel Micay
2016-01-19 21:35 ` [PATCH RESEND] perf: Document the perf sysctls Ben Hutchings
2016-01-21 14:25 ` Arnaldo Carvalho de Melo [this message]
2016-02-03 10:08 ` [tip:perf/core] perf tools: " tip-bot for Ben Hutchings
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