linux-kernel - Re: [PATCH v4 12/53] perf bpf: Don't synthesize BPF events when disabled

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ZUuz/8EC0orXCffn@kernel.org>
Date:   Wed, 8 Nov 2023 13:14:55 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Ian Rogers <irogers@...gle.com>, Song Liu <songliubraving@...com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Mark Rutland <mark.rutland@....com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Nick Terrell <terrelln@...com>,
        Kan Liang <kan.liang@...ux.intel.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Kajol Jain <kjain@...ux.ibm.com>,
        Athira Rajeev <atrajeev@...ux.vnet.ibm.com>,
        Huacai Chen <chenhuacai@...nel.org>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Vincent Whitchurch <vincent.whitchurch@...s.com>,
        "Steinar H. Gunderson" <sesse@...gle.com>,
        Liam Howlett <liam.howlett@...cle.com>,
        Miguel Ojeda <ojeda@...nel.org>,
        Colin Ian King <colin.i.king@...il.com>,
        Dmitrii Dolgov <9erthalion6@...il.com>,
        Yang Jihong <yangjihong1@...wei.com>,
        Ming Wang <wangming01@...ngson.cn>,
        James Clark <james.clark@....com>,
        K Prateek Nayak <kprateek.nayak@....com>,
        Sean Christopherson <seanjc@...gle.com>,
        Leo Yan <leo.yan@...aro.org>,
        Ravi Bangoria <ravi.bangoria@....com>,
        German Gomez <german.gomez@....com>,
        Changbin Du <changbin.du@...wei.com>,
        Paolo Bonzini <pbonzini@...hat.com>, Li Dong <lidong@...o.com>,
        Sandipan Das <sandipan.das@....com>,
        liuwenyu <liuwenyu7@...wei.com>, linux-kernel@...r.kernel.org,
        linux-perf-users@...r.kernel.org
Subject: Re: [PATCH v4 12/53] perf bpf: Don't synthesize BPF events when
 disabled

Em Thu, Nov 02, 2023 at 10:56:54AM -0700, Ian Rogers escreveu:
> If BPF sideband events are disabled on the command line, don't
> synthesize BPF events too.


Interesting, in 71184c6ab7e60fd5 ("perf record: Replace option
--bpf-event with --no-bpf-event") we checked that, but only down at
perf_event__synthesize_one_bpf_prog(), where we have:

        if (!opts->no_bpf_event) {
                /* Synthesize PERF_RECORD_BPF_EVENT */
                *bpf_event = (struct perf_record_bpf_event)


So we better remove that, now redundant check? I'll apply your patch as
is and then we can remove that other check.

Song, can I have your Acked-by or Reviewed-by, please?

- Arnaldo


 
> Signed-off-by: Ian Rogers <irogers@...gle.com>
> ---
>  tools/perf/util/bpf-event.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/perf/util/bpf-event.c b/tools/perf/util/bpf-event.c
> index 38fcf3ba5749..830711cae30d 100644
> --- a/tools/perf/util/bpf-event.c
> +++ b/tools/perf/util/bpf-event.c
> @@ -386,6 +386,9 @@ int perf_event__synthesize_bpf_events(struct perf_session *session,
>  	int err;
>  	int fd;
>  
> +	if (opts->no_bpf_event)
> +		return 0;
> +
>  	event = malloc(sizeof(event->bpf) + KSYM_NAME_LEN + machine->id_hdr_size);
>  	if (!event)
>  		return -1;
> -- 
> 2.42.0.869.gea05f2083d-goog
> 

-- 

- Arnaldo