linux-kernel - Re: Deadlock on poweroff

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-next>] [day] [month] [year] [list]

Message-ID: <20121007165012.GA23535@shutemov.name>
Date:	Sun, 7 Oct 2012 19:50:12 +0300
From:	"Kirill A. Shutemov" <kirill@...temov.name>
To:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
Cc:	linux-kernel@...r.kernel.org, Dipankar Sarma <dipankar@...ibm.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Steffen Klassert <steffen.klassert@...unet.com>,
	linux-crypto@...r.kernel.org
Subject: Re: Deadlock on poweroff

On Sun, Oct 07, 2012 at 09:03:11AM -0700, Paul E. McKenney wrote:
> On Sun, Oct 07, 2012 at 05:47:11AM +0300, Kirill A. Shutemov wrote:
> > Hi Paul and all,
> > 
> > With commit 755609a9087fa983f567dc5452b2fa7b089b591f I've got deadlock on
> > poweroff.
> > 
> > It guess it happens because of race for cpu_hotplug.lock:
> > 
> > 	CPU A					CPU B
> > disable_nonboot_cpus()
> > _cpu_down()
> > cpu_hotplug_begin()
> >  mutex_lock(&cpu_hotplug.lock);
> > __cpu_notify()
> > padata_cpu_callback()
> > __padata_remove_cpu()
> > padata_replace()
> > synchronize_rcu()
> > 					rcu_gp_kthread()
> > 					get_online_cpus();
> > 					mutex_lock(&cpu_hotplug.lock);
> > 
> > Have you seen the issue before?
> 
> This is a new one for me.  Does the following (very lightly tested)
> patch help?

Works for me. Thanks.

-- 
 Kirill A. Shutemov
--
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/