linux-kernel - Re: [PATCH 01/10] cgroup: add cgroup_root

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]

Date:	Fri, 4 Nov 2011 17:38:34 +0900
From:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
To:	Tejun Heo <tj@...nel.org>
Cc:	paul@...lmenage.org, rjw@...k.pl, lizf@...fujitsu.com,
	linux-pm@...ts.linux-foundation.org, linux-kernel@...r.kernel.org,
	containers@...ts.linux-foundation.org, fweisbec@...il.com,
	matthltc@...ibm.com, akpm@...ux-foundation.org, oleg@...hat.com,
	kamezawa.hiroyu@...fujitsu.com
Subject: Re: [PATCH 01/10] cgroup: add cgroup_root_mutex

On Tue,  1 Nov 2011 16:46:24 -0700
Tejun Heo <tj@...nel.org> wrote:

> cgroup wants to make threadgroup stable while modifying cgroup
> hierarchies which will introduce locking dependency on
> cred_guard_mutex from cgroup_mutex.  This unfortunately completes
> circular dependency.
> 
>  A. cgroup_mutex -> cred_guard_mutex -> s_type->i_mutex_key -> namespace_sem
>  B. namespace_sem -> cgroup_mutex
> 
> B is from cgroup_show_options() and this patch breaks it by
> introducing another mutex cgroup_root_mutex which nests inside
> cgroup_mutex and protects cgroupfs_root.
> 
> Signed-off-by: Tejun Heo <tj@...nel.org>
> Cc: Oleg Nesterov <oleg@...hat.com>

Thanks,
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>

--
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/