linux-kernel - Re: [ltt-dev] Tracing thread name

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] [day] [month] [year] [list]

Date:	Thu, 13 Aug 2009 17:57:16 +0200
From:	Matthieu CASTET <matthieu.castet@...rot.com>
To:	Mathieu Desnoyers <compudj@...stal.dyndns.org>
CC:	Ingo Molnar <mingo@...e.hu>,
	"ltt-dev@...ts.casi.polymtl.ca" <ltt-dev@...ts.casi.polymtl.ca>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"rostedt@...dmis.org" <rostedt@...dmis.org>
Subject: Re: [ltt-dev] Tracing thread name

Matthieu CASTET a écrit :
> Hi,
> 
> Mathieu Desnoyers a écrit :
>> * Matthieu CASTET (matthieu.castet@...rot.com) wrote:
>>> Hi Mathieu,
>>>
>>> Mathieu Desnoyers a écrit :
>>> Do you know if it is possible to patch my version to add such feature ?
>>>
>>> I saw that the name already change in the trace before/after an exec.
>>> How lltv get the new name ?
>>> With "fs.exec" tracepoint ?
>>> In that case I could fake a "fs.exec" tracepoint in set_task_comm.
>> A better solution : you add a new event in both lttng and lttv, and
>> modify state.c to support your new event. The current event to brand
>> thread is named "userspace.thread_brand". Look for this in LTTV to see
>> all the sites that need to support the new event (there are very few).
>>
> Thanks, but I want to avoid to modify too much ltt (I use an old version
> for 2.6.27 and my modifications may be useless for upstream).
> 
> I added "trace_fs_exec(tsk->comm);" at the end of set_task_comm and now
> the thread got the correct name :)
> 
BTW it is also interesting to get the name of the kernel threads
(created by kthread_create).
The current version of ltt show "kthreadd" for these threads.

The same solution than set_task_comm should solve the problem (comm is
set at the end of kthread_create).


Matthieu

PS: khelper thread are also annoying because they all got the same name.
May be it could be interesting to add extra info in the name.

--
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/