linux-kernel - Re: [PATCH] forcedeth: hardirq lockdep warning

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]

Date:	Tue, 19 Sep 2006 21:12:10 +0200
From:	Peter Zijlstra <a.p.zijlstra@...llo.nl>
To:	Andrew Morton <akpm@...l.org>
Cc:	Ayaz Abdulla <aabdulla@...dia.com>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	Jeff Garzik <jeff@...zik.org>, Ingo Molnar <mingo@...e.hu>,
	Arjan van de Ven <arjan@...ux.intel.com>,
	Dave Jones <davej@...hat.com>
Subject: Re: [PATCH] forcedeth: hardirq lockdep warning

On Tue, 2006-09-19 at 11:14 -0700, Andrew Morton wrote:
> On Tue, 19 Sep 2006 14:55:22 +0200
> Peter Zijlstra <a.p.zijlstra@...llo.nl> wrote:
> 
> > BUG: warning at kernel/lockdep.c:1816/trace_hardirqs_on() (Not tainted)
> 
> I wonder what line that was.  DEBUG_LOCKS_WARN_ON(current->hardirq_context),
> I suppose.

Correct indeed.

> > Call Trace:
> >  show_trace
> >  dump_stack
> >  trace_hardirqs_on
> >  :forcedeth:nv_nic_irq_other
> >  handle_IRQ_event
> >  __do_IRQ
> >  do_IRQ
> >  ret_from_intr
> > DWARF2 barf
> 
> It's good, isn't it?

Yeah, I hope we'll get it sorted out quickly....

> >  default_idle
> >  cpu_idle
> >  rest_init
> >  start_kernel
> >  _sinittext
> >  
> > These 3 functions nv_nic_irq_tx(), nv_nic_irq_rx() and nv_nic_irq_other()
> > are reachable from IRQ context and process context.
> 
> That's "fix deadlock", not "fix lockdep warning".  However it's often the
> case that it's not really deadlockable because (often) the card's IRQ line
> has been disabled.  That appears to be the case in nv_do_nic_poll()'s call
> to nv_nic_irq_tx, for example.

Yeah, I saw some of that. But I'm not well versed in the various netdev
irq receive paths nor in the driver. I couldn't find the actual
maintainer in the MAINTAINERS file nor in the source, thanks for
including him in the CC. Lets hope he can say if this is an actual fix
or just a workaround.



-
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/