linux-kernel - Re: [PATCH 3/6] staging: android/lowmemorykiller: Don't grab tasklist

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: <20120208153216.GB15782@redhat.com>
Date:	Wed, 8 Feb 2012 16:32:16 +0100
From:	Oleg Nesterov <oleg@...hat.com>
To:	Anton Vorontsov <anton.vorontsov@...aro.org>
Cc:	Greg KH <gregkh@...uxfoundation.org>,
	Arve Hjønnevåg <arve@...roid.com>,
	KOSAKI Motohiro <kosaki.motohiro@...il.com>,
	San Mehat <san@...gle.com>, Colin Cross <ccross@...roid.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	linux-kernel@...r.kernel.org, kernel-team@...roid.com,
	linaro-kernel@...ts.linaro.org
Subject: Re: [PATCH 3/6] staging: android/lowmemorykiller: Don't grab
	tasklist_lock

On 02/06, Anton Vorontsov wrote:
>
> Grabbing tasklist_lock has its disadvantages, i.e. it blocks
> process creation and destruction. If there are lots of processes,
> blocking doesn't sound as a great idea.
>
> For LMK, it is sufficient to surround tasks list traverse with
> rcu_read_{,un}lock().
>
> From now on using force_sig() is not safe, as it can race with an
> already exiting task, so we use send_sig() now. As a downside, it
> won't kill PID namespace init processes, but that's not what we
> want anyway.

Reviewed-by: Oleg Nesterov <oleg@...hat.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/