linux-kernel - Re: [PATCH V3 20/37] perf script: Add 'synth' event type for synthesized events

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: <20170621135145.GO13640@kernel.org>
Date:   Wed, 21 Jun 2017 10:51:45 -0300
From:   Arnaldo Carvalho de Melo <acme@...nel.org>
To:     Adrian Hunter <adrian.hunter@...el.com>
Cc:     Andi Kleen <ak@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Jiri Olsa <jolsa@...nel.org>,
        Namhyung Kim <namhyung@...nel.org>,
        Wang Nan <wangnan0@...wei.com>,
        David Ahern <dsahern@...il.com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH V3 20/37] perf script: Add 'synth' event type for
 synthesized events

Em Wed, Jun 21, 2017 at 01:17:19PM +0300, Adrian Hunter escreveu:
> +++ b/tools/perf/util/event.h
> @@ -252,6 +252,9 @@ enum auxtrace_error_type {
>        PERF_AUXTRACE_ERROR_MAX
> };

> +/* Attribute type for custom synthesized events */
> +#define PERF_TYPE_SYNTH		3000000000

Why don't you make it PERF_TYPE_MAX and bump PERF_TYPE_MAX by one? I.e.
this way we have what can be in attr.type in a nice enumeration, can
validate it more easily (attr.type < PERF_TYPE_MAX) and will not need to 
do those conversions to/from OUTPUT_TYPE_/PERF_TYPE_).

Peter: now its not the PERF_RECORD_ namespace that userspaces want a
chunk of, its PERF_TYPE_, which so far has been pretty stable, grabing
_one_ for event synthesizing things like Intel PT (and ARM's coresight,
I think) directly at include/uapi/linux/perf_event.h's perf_type_id enum
looks cleaner, no?

- Arnaldo