Re: [PATCH v4 0/3] Send audit/procinfo/cgroup data in socket-levelcontrol message

[Tejun Heo]

Hello,

On Mon, Jan 13, 2014 at 09:01:46AM +0100, Jan Kaluza wrote:
> this patchset against net-next (applies also to linux-next) adds 3 new types
> of "Socket"-level control message (SCM_AUDIT, SCM_PROCINFO and SCM_CGROUP).
> 
> Server-like processes in many cases need credentials and other
> metadata of the peer, to decide if the calling process is allowed to
> request a specific action, or the server just wants to log away this
> type of information for auditing tasks.
> 
> The current practice to retrieve such process metadata is to look that
> information up in procfs with the $PID received over SCM_CREDENTIALS.
> This is sufficient for long-running tasks, but introduces a race which
> cannot be worked around for short-living processes; the calling
> process and all the information in /proc/$PID/ is gone before the
> receiver of the socket message can look it up.
> 
> Changes introduced in this patchset can also increase performance
> of such server-like processes, because current way of opening and
> parsing /proc/$PID/* files is much more expensive than receiving these
> metadata using SCM.

Closing the race sounds like a good idea to me.  What do net people
think?

Thanks.

-- 
tejun
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