linux-kernel - Re: [PATCH 5/5] cgroup: separate out cgroup_attach

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: <20111221000231.GX13529@google.com>
Date:	Tue, 20 Dec 2011 16:02:31 -0800
From:	Mandeep Singh Baines <msb@...omium.org>
To:	Tejun Heo <tj@...nel.org>
Cc:	Mandeep Singh Baines <msb@...omium.org>,
	Li Zefan <lizf@...fujitsu.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	containers@...ts.linux-foundation.org, cgroups@...r.kernel.org,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Oleg Nesterov <oleg@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Paul Menage <paul@...lmenage.org>
Subject: Re: [PATCH 5/5] cgroup: separate out cgroup_attach_proc error
 handling code

Tejun Heo (tj@...nel.org) wrote:
> Hello,
> 
> On Tue, Dec 20, 2011 at 03:14:33PM -0800, Mandeep Singh Baines wrote:
> > @@ -2067,9 +2067,10 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
> >  	read_unlock(&tasklist_lock);
> >  
> >  	/* methods shouldn't be called if no task is actually migrating */
> > -	retval = 0;
> > -	if (!group_size)
> > +	if (!group_size) {
> > +		retval = 0;
> >  		goto out_free_group_list;
> > +	}
> 
> Eh... I don't think this is an improvement.  It's just different.
> 

The main benefit is that the comment is directly above the code its
describing but I can drop this part of the change.

> > @@ -2126,20 +2127,20 @@ int cgroup_attach_proc(struct cgroup *cgrp, struct task_struct *leader)
> >  	 */
> >  	synchronize_rcu();
> >  	cgroup_wakeup_rmdir_waiter(cgrp);
> > -	retval = 0;
> > +	flex_array_free(group);
> > +	return 0;
> 
> Hmm... maybe goto out_free_group_list?  Duplicating cleanup on success
> and failure paths can lead future updaters forget one of them.  The
> exit path in this function isn't pretty but I don't think the proposed
> patch improves it either.
> 

Should I drop the patch or add the goto? Its 5/5 so easy enough to drop
since nothing else depends on it.

> Thanks.
> 
> -- 
> tejun
--
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/