netdev - Re: + gen_estimator-fix-locking-and-timer-related-bugs.patch added to -mm tree

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: <1183733732.6389.26.camel@ranko-fc2.spidernet.net>
Date:	Fri, 06 Jul 2007 17:55:32 +0300
From:	Ranko Zivojnovic <ranko@...dernet.net>
To:	Patrick McHardy <kaber@...sh.net>
Cc:	Jarek Poplawski <jarkao2@...pl>, akpm@...ux-foundation.org,
	netdev@...r.kernel.org
Subject: Re: + gen_estimator-fix-locking-and-timer-related-bugs.patch added
	to -mm tree

On Fri, 2007-07-06 at 16:21 +0200, Patrick McHardy wrote:
> Ranko Zivojnovic wrote:
> > BUG: spinlock lockup on CPU#0, swapper/0, c03eff80
> >  [<c01ed1fe>] _raw_spin_lock+0x108/0x13c
> >  [<c02a8468>] __qdisc_run+0x97/0x1b0
> >  [<c02a96f3>] qdisc_watchdog+0x19/0x58
> >  [<c02fe5e7>] __lock_text_start+0x37/0x43
> >  [<c02a9730>] qdisc_watchdog+0x56/0x58
> >  [<c02a96da>] qdisc_watchdog+0x0/0x58
> >  [<c0135d84>] run_hrtimer_softirq+0x58/0xb5
> >  [...]
> 
> > BUG: spinlock lockup on CPU#1, swapper/0, c03eff80
> >  [<c01ed1fe>] _raw_spin_lock+0x108/0x13c
> >  [<c0298b9b>] est_timer+0x53/0x148
> >  [<c01294b3>] run_timer_softirq+0x30/0x184
> >  [<c01295a4>] run_timer_softirq+0x121/0x184
> >  [<c0126252>] __do_softirq+0x66/0xf3
> >  [<c0298b48>] est_timer+0x0/0x148
> >  [...]
> 
> 
> There is at least one ABBA deadlock, est_timer does:
> 
> read_lock(&est_lock)
> spin_lock(e->stats_lock) (which is dev->queue_lock)
> 
> and qdisc_destroy calls htb_destroy under dev->queue_lock, which
> calls htb_destroy_class, then gen_kill_estimator and this
> write_locks est_lock.
> 
> I can't see the problem above though, the qdisc_run path only takes
> dev->queue_lock. Please enable lockdep and post the output if any.

That was with lockdep already enabled:
$ zgrep LOCKDEP /proc/config.gz
CONFIG_LOCKDEP_SUPPORT=y
CONFIG_LOCKDEP=y
# CONFIG_DEBUG_LOCKDEP is not set

also with:
CONFIG_PROVE_LOCKING=y
CONFIG_DEBUG_LOCK_ALLOC=y

that Jarek suggested, and including:
CONFIG_DETECT_SOFTLOCKUP=y
CONFIG_DEBUG_SPINLOCK=y

I will give it another spin as it is, just to see if it will show a
different path - and then I will try 2.6.21.5 with these two patches.

R.

-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html