linux-kernel - Re: [PATCH v4 4/7] cgroup: cgroup v2 freezer

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: <20181203144906.GE31795@redhat.com>
Date:   Mon, 3 Dec 2018 15:49:06 +0100
From:   Oleg Nesterov <oleg@...hat.com>
To:     Roman Gushchin <guroan@...il.com>
Cc:     Tejun Heo <tj@...nel.org>,
        Dan Carpenter <dan.carpenter@...cle.com>,
        Mike Rapoport <rppt@...ux.vnet.ibm.com>,
        cgroups@...r.kernel.org, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org, kernel-team@...com,
        Roman Gushchin <guro@...com>
Subject: Re: [PATCH v4 4/7] cgroup: cgroup v2 freezer

On 11/30, Roman Gushchin wrote:
>
> +void cgroup_enter_frozen(void)
> +{
> +	if (!current->frozen) {
> +		struct cgroup *cgrp;
> +
> +		spin_lock_irq(&css_set_lock);
> +		current->frozen = true;
> +		cgrp = task_dfl_cgroup(current);
> +		cgrp->freezer.nr_frozen_tasks++;
> +		WARN_ON_ONCE(cgrp->freezer.nr_frozen_tasks >
> +			     cgrp->freezer.nr_tasks_to_freeze);
> +		cgroup_update_frozen(cgrp, true);
> +		spin_unlock_irq(&css_set_lock);
> +	}
> +
> +	__set_current_state(TASK_INTERRUPTIBLE);
> +	schedule();
> +	__set_current_state(TASK_RUNNING);

forgot to mention, schedule() always returns in TASK_RUNNING, so the 2nd
__set_current_state() is pointless.

Oleg.