netdev - Re: [PATCH nf-next] netfilter: xtables: lightweight process control group matching

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: <52528219.6000002@cn.fujitsu.com>
Date:	Mon, 07 Oct 2013 17:42:49 +0800
From:	Gao feng <gaofeng@...fujitsu.com>
To:	Daniel Borkmann <dborkman@...hat.com>
CC:	pablo@...filter.org, netfilter-devel@...r.kernel.org,
	netdev@...r.kernel.org, Tejun Heo <tj@...nel.org>,
	cgroups@...r.kernel.org
Subject: Re: [PATCH nf-next] netfilter: xtables: lightweight process control
 group matching

On 10/07/2013 05:17 PM, Daniel Borkmann wrote:
> On 10/07/2013 05:07 AM, Gao feng wrote:
>> On 10/05/2013 02:20 AM, Daniel Borkmann wrote:
>>> +static void cgroup_attach(struct cgroup_subsys_state *css,
>>> +              struct cgroup_taskset *tset)
>>> +{
>>> +    struct task_struct *p;
>>> +    void *v;
>>> +
>>> +    cgroup_taskset_for_each(p, css, tset) {
>>> +        task_lock(p);
>>> +        v = (void *)(unsigned long) task_fwid(p);
>>
>> Shouldn't v be css_nf_state(css)->fwid?
> 
> Nope, this is in line with net_cls and net_prio; the task has been
> moved there via cgroup backend already through cgroup_attach_task(),

Yes, these tasks have already been migrated to this cgroup.

> so we only need to update each of it's socket sk_cgrp_fwid parts.

Sorry, I still don't know in which situation that css_nf_state(css)->fwid
isn't equal to task_fwid(p).

two threads write the same pid to different cgroup at the same time?
it seems can not happen since we have cgroup_mutex protected.

> css is not strictly for net_filter. See also: 6a328d8c6f (cgroup:
> net_cls: Rework update socket logic)
> 
>>> +        iterate_fd(p->files, 0, cgroup_fwid_update, v);
>>> +        task_unlock(p);
>>> +    }
>>> +}
> 

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html