linux-kernel - Re: [PATCH 1/3] cgroup/cpuset: Make cpuset_fork() handle CLONE_INTO

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: <20230406-vernommen-kurieren-e75f4ee6ea96@brauner>
Date:   Thu, 6 Apr 2023 11:45:53 +0200
From:   Christian Brauner <brauner@...nel.org>
To:     Waiman Long <longman@...hat.com>
Cc:     Tejun Heo <tj@...nel.org>, Zefan Li <lizefan.x@...edance.com>,
        Johannes Weiner <hannes@...xchg.org>, cgroups@...r.kernel.org,
        linux-kernel@...r.kernel.org, Juri Lelli <juri.lelli@...hat.com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        gscrivan@...hat.com
Subject: Re: [PATCH 1/3] cgroup/cpuset: Make cpuset_fork() handle
 CLONE_INTO_CGROUP properly

On Fri, Mar 31, 2023 at 10:50:43AM -0400, Waiman Long wrote:
> By default, the clone(2) syscall spawn a child process into the same
> cgroup as its parent. With the use of the CLONE_INTO_CGROUP flag
> introduced by commit ef2c41cf38a7 ("clone3: allow spawning processes
> into cgroups"), the child will be spawned into a different cgroup which
> is somewhat similar to writing the child's tid into "cgroup.threads".
> 
> The current cpuset_fork() method does not properly handle the
> CLONE_INTO_CGROUP case where the cpuset of the child may be different
> from that of its parent.  Update the cpuset_fork() method to treat the
> CLONE_INTO_CGROUP case similar to cpuset_attach().
> 
> Since the newly cloned task has not been running yet, its actual
> memory usage isn't known. So it is not necessary to make change to mm
> in cpuset_fork().
> 
> Fixes: ef2c41cf38a7 ("clone3: allow spawning processes into cgroups")
> Signed-off-by: Waiman Long <longman@...hat.com>
> ---

Just two nits. I think this needs a Cc stable and it would be nice if
you could give Giuseppe a "Reported-by".