linux-kernel - Re: [PATCH v2 1/2] perf: add container identifier entry in perf sample data

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: <20160902135936.GH10153@twins.programming.kicks-ass.net>
Date:   Fri, 2 Sep 2016 15:59:36 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Hari Bathini <hbathini@...ux.vnet.ibm.com>
Cc:     ast@...com, lkml <linux-kernel@...r.kernel.org>, acme@...nel.org,
        alexander.shishkin@...ux.intel.com, mingo@...hat.com,
        daniel@...earbox.net, rostedt@...dmis.org,
        Ananth N Mavinakayanahalli <ananth@...ux.vnet.ibm.com>,
        ebiederm@...ssion.com, sargun@...gun.me,
        Aravinda Prasad <aravinda@...ux.vnet.ibm.com>,
        brendan.d.gregg@...il.com
Subject: Re: [PATCH v2 1/2] perf: add container identifier entry in perf
 sample data

On Fri, Sep 02, 2016 at 07:25:31PM +0530, Hari Bathini wrote:
> >I'm thinking this value is mostly the same for tasks, just like COMM and
> 
> I think so, too. Namespaces aren't changed that often for tasks...
> 
> >MMAP. Could we therefore not emit (sideband) events whenever a task
> >changes namespace and get the same information but with tons less data?
> 
> You mean, something like PERF_RECORD_NAMESPACE that
> emits events on fork, clone, setns..?

Yep.

> 
> >That also gives the possibility of recording all namespaces, not just
> >the one.
> 
> True. If we record all namespaces, container identifier interpretation
> can be left to the userspace to decide, which is much more flexible...

The only complication is initial state, on record start you'd have to
trawl /proc and generate 'fake' namespace records for all (relevant)
tasks.

We do the same with MMAP records, we parse /proc/$pid/maps for that.

Is this namespace stuff available in /proc somewhere?