linux-kernel - Re: rcu: BUG: spinlock recursion on CPU#3, trinity-child19/5970

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: <20120702145927.GD2508@linux.vnet.ibm.com>
Date:	Mon, 2 Jul 2012 07:59:27 -0700
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Sasha Levin <levinsasha928@...il.com>
Cc:	Peter Zijlstra <peterz@...radead.org>,
	Dave Jones <davej@...hat.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: rcu: BUG: spinlock recursion on CPU#3, trinity-child19/5970

On Mon, Jul 02, 2012 at 04:36:53PM +0200, Sasha Levin wrote:
> On Mon, 2012-07-02 at 07:22 -0700, Paul E. McKenney wrote:
> > > OK, so it looks like the context-switch-time call into preemptible RCU
> > > needs to be outside of the runqueue-lock critical section.  One way
> > > to do this is be reverting 616c310e (Move PREEMPT_RCU preemption to
> > > switch_to() invocation).  Sasha, could you please try this out?
> > 
> > Hmmmm...  Here is a patch for this reversion on top of -rcu with
> > conflicts resolved. 
> 
> It looks like how I've resolved it.

Good show!!!

> Just for clarity, the only rcu related patch I have on top of -next is
> this reversal one. I've dropped anything we tested before.
> 
> Looks like its running fine for a bit now (~10 min). I'll ping if
> anything changes, but on the other tests it has usually failed at this
> point.

If testing goes well (both yours and mine), I will be submitting this
as urgent, since it is a 3.5 regression.  If they don't take it, I will
queue it for 3.6.

							Thanx, Paul

--
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/