linux-kernel - Re: [PATCH 13/16] cgroup_freezer: prepare for removal of TIF

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: <20110828173954.GA26588@redhat.com>
Date:	Sun, 28 Aug 2011 19:39:54 +0200
From:	Oleg Nesterov <oleg@...hat.com>
To:	Tejun Heo <tj@...nel.org>
Cc:	rjw@...k.pl, paul@...lmenage.org, linux-kernel@...r.kernel.org,
	arnd@...db.de, Li Zefan <lizf@...fujitsu.com>
Subject: Re: [PATCH 13/16] cgroup_freezer: prepare for removal of TIF_FREEZE

Hi Tejun.

Well, yet another sorry for delay ;)

On 08/19, Tejun Heo wrote:
>
> @@ -279,7 +268,6 @@ static int try_to_freeze_cgroup(struct cgroup *cgroup, struct freezer *freezer)
>  	struct task_struct *task;
>  	unsigned int num_cant_freeze_now = 0;
>
> -	freezer->state = CGROUP_FREEZING;

...

> @@ -321,6 +307,8 @@ static int freezer_change_state(struct cgroup *cgroup,
>  	if (goal_state == freezer->state)
>  		goto out;
>
> +	freezer->state = goal_state;
> +

This doesn't look right at all... Unless I misssed something.

A user writes "FROZEN" into the control file, our goal is CGROUP_FROZEN.

But. freezer_change_state() should set CGROUP_FREEZING, not CGROUP_FROZEN.
This cgrp is not frozen yet, _FROZEN should be set by update_if_frozen(),
assuming that the user reads the state waiting until the operation
completes.

Oleg.

--
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/