linux-kernel - Re: [kernel.org users] [KORG] Panics on master backend

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: <1314623216.2816.25.camel@twins>
Date:	Mon, 29 Aug 2011 15:06:56 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	Frank Rowand <frank.rowand@...sony.com>,
	linux-kernel <linux-kernel@...r.kernel.org>, users@...nel.org,
	hch <hch@...radead.org>, "yong.zhang0" <yong.zhang0@...il.com>,
	scameron@...rdog.cce.hp.com, Jens Axboe <jaxboe@...ionio.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	"James E.J. Bottomley" <jejb@...isc-linux.org>
Subject: Re: [kernel.org users] [KORG] Panics on master backend

On Thu, 2011-08-25 at 15:54 +0200, Oleg Nesterov wrote:
> > Isn't us holding ->pi_lock sufficient to stabilize task_cpu()? If its a
> > running task the initial ->state check would have failed,
> 
> Of course it is not TASK_RUNNING, but it can be running or not.
> 
> > and thus its a
> > proper wakeup when we get here and thus ->pi_lock is serializing things.
> 
> I am not sure. If ->on_rq is true, we need rq->lock. Say, pull_task() can
> change its cpu. 

If its !TASK_RUNNING but ->on_rq is true, it must be current, and
pull_task() will never move current around.


--
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/