linux-kernel - Re: lockdep recursive locking detected (rcu_kthread / __cache

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: <1317675980.9417.1.camel@twins>
Date:	Mon, 03 Oct 2011 23:06:19 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Christoph Lameter <cl@...two.org>
Cc:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Sitsofe Wheeler <sitsofe@...oo.com>,
	Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org,
	penberg@...nel.org, mpm@...enic.com, linux-mm@...ck.org
Subject: Re: lockdep recursive locking detected (rcu_kthread / __cache_free)

On Mon, 2011-10-03 at 15:46 -0500, Christoph Lameter wrote:
> On Mon, 3 Oct 2011, Paul E. McKenney wrote:
> 
> > The first lock was acquired here in an RCU callback.  The later lock that
> > lockdep complained about appears to have been acquired from a recursive
> > call to __cache_free(), with no help from RCU.  This looks to me like
> > one of the issues that arise from the slab allocator using itself to
> > allocate slab metadata.
> 
> Right. However, this is a false positive since the slab cache with
> the metadata is different from the slab caches with the slab data. The slab
> cache with the metadata does not use itself any metadata slab caches.

Sure, but we're supposed to have annotated that.. see
init_node_lock_keys()
--
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/