linux-kernel - Re: [PATCH] cgroups: fix API thinko

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:	Wed, 25 Aug 2010 19:08:46 -0700
From:	Paul Menage <menage@...gle.com>
To:	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Alex Williamson <alex.williamson@...hat.com>,
	Sridhar Samudrala <sri@...ibm.com>,
	"Michael S. Tsirkin" <mst@...hat.com>,
	Li Zefan <lizf@...fujitsu.com>, Ben Blum <bblum@...gle.com>,
	containers@...ts.linux-foundation.org,
	linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Subject: Re: [PATCH] cgroups: fix API thinko

On Wed, Aug 25, 2010 at 2:35 PM, Andrew Morton
<akpm@...ux-foundation.org> wrote:
>
> So am I correct to assume that this change is now needed in 2.6.36, and
> unneeded in 2.6.35?
>
> Can it affect the userspace<->kernel API in amy manner?  If so, it
> should be backported into earlier kernels to reduce the number of
> incompatible kernels out there.

AFAICS it shouldn't affect any existing APIs, either in-kernel or to
userspace - it just makes the existing function
cgroup_attach_task_current_cg() a specialization of a more generic new
function.

>
> Paul, did you have any comments?

Other than the language being a bit confusing, it seems fine. I'd
probably word the patch description as:

Add cgroup_attach_task_all()

The existing cgroup_attach_task_current_cg() API is called by a thread
to attach another thread to all of its cgroups; this is unsuitable for
cases where a privileged task wants to attach itself to the cgroups
of a less privileged one, since the call must be made from the context
of the target task.

This patch adds a more generic cgroup_attach_task_all() API that
allows both the source task and to-be-moved task to be specified.
cgroup_attach_task_current_cg() becomes a specialization of the more
generic new function.

Acked-by: Paul Menage <menage@...gle.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/