linux-kernel - Re: [PATCH v4 2/3] Support for perf to probe into SDT markers:

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: <CAOJsxLFKm3TxeTmGjbpr1r4sZ8fHcM481-5BM_Cq0J8hhtvBqQ@mail.gmail.com>
Date:	Fri, 25 Oct 2013 14:38:17 +0200
From:	Pekka Enberg <penberg@...nel.org>
To:	Hemant Kumar <hkshaw@...ux.vnet.ibm.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Oleg Nesterov <oleg@...hat.com>,
	hegdevasant@...ux.vnet.ibm.com, Ingo Molnar <mingo@...hat.com>,
	anton@...hat.com, systemtap@...rceware.org,
	Namhyung Kim <namhyung@...nel.org>,
	Masami Hiramatsu <masami.hiramatsu.pt@...achi.com>,
	aravinda@...ux.vnet.ibm.com
Subject: Re: [PATCH v4 2/3] Support for perf to probe into SDT markers:

Hello Hemant,

On Wed, Oct 23, 2013 at 7:05 AM, Hemant Kumar <hkshaw@...ux.vnet.ibm.com> wrote:
> This allows perf to probe into the sdt markers/notes present in
> the libraries and executables. We try to find the associated location
> and handle prelinking (since, stapsdt notes section is not allocated
> during runtime). Prelinking is handled with the help of base
> section which is allocated during runtime. This address can be compared
> with the address retrieved from the notes' description. If its different,
> we can take this difference and then add to the note's location.
>
> We can use existing '-a/--add' option to add events for sdt markers.
> Also, we can add multiple events at once using the same '-a' option.
>
> Usage:
> perf probe -x /lib64/libc.so.6 -a 'my_event=%libc:setjmp'
>
> Output:
> Added new event:
>   libc:my_event        (on 0x35981)
>
> You can now use it in all perf tools, such as:
>
>     perf record -e libc:my_event -aR sleep 1

Is there a technical reason why 'perf list' could not show all the
available SDT markers on a system and that the 'market to event'
mapping cannot happen automatically?

So instead of doing all the command line magic above I'd do:

  perf list

  libc:setjmp [SDT marker]

and I could just do

  perf record -e libc:setjmp -AR sleep 1

?

                    Pekka
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/