linux-kernel - Re: linux-next oops in __lock_acquire for process_one

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: <1336496568.8226.34.camel@twins>
Date:	Tue, 08 May 2012 19:02:48 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Tejun Heo <tj@...nel.org>
Cc:	Hugh Dickins <hughd@...gle.com>, Ingo Molnar <mingo@...hat.com>,
	Stephen Boyd <sboyd@...eaurora.org>,
	Yong Zhang <yong.zhang0@...il.com>,
	linux-kernel@...r.kernel.org
Subject: Re: linux-next oops in __lock_acquire for process_one_work

On Tue, 2012-05-08 at 09:58 -0700, Tejun Heo wrote:
> On Tue, May 08, 2012 at 03:03:22PM +0200, Peter Zijlstra wrote:
> > I think there's a problem if indeed we do silly things like small copies
> > like Hugh saw (why would gcc ever generate small copies for objects that
> > are naturally aligned and naturally sized?).
> > 
> > Something like the below should fix that problem, but it doesn't explain
> > the observed issue..
> 
> Hmmm.... Hugh, can you please verify whether this patch makes the
> problem go away somehow?
> 
> > @@ -1810,7 +1810,7 @@ __acquires(&gcwq->lock)
> >  	 * lock freed" warnings as well as problems when looking into
> >  	 * work->lockdep_map, make a copy and use that here.
> >  	 */
> > -	struct lockdep_map lockdep_map = work->lockdep_map;
> > +	struct lockdep_map lockdep_map = lockdep_copy_map(&work->lockdep_map);
> 
> If this is the correct fix for whatever reason, maybe we want the copy
> interface to be a bit more conventional?  lockdep_copy_map(to, from)?

Sure why not.. still not quite understanding the whole issue though.


--
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/