Re: [LOCKDEP] 2.6.18-rc1: inconsistent {hardirq-on-W} -> {in-hardirq-W} usage

[jfannin@gmail.com (Joseph Fannin)]

On Sun, Jul 09, 2006 at 09:45:44AM +0200, Ingo Molnar wrote:
>
> * Andrew Morton <akpm@osdl.org> wrote:
>
> > yup, thanks, bug.
> >
> > --- a/arch/i386/kernel/time.c~get_cmos_time-locking-fix
> > +++ a/arch/i386/kernel/time.c
> > @@ -206,15 +206,16 @@ irqreturn_t timer_interrupt(int irq, voi
> >  unsigned long get_cmos_time(void)
> >  {
> >  	unsigned long retval;
> > +	unsigned long flags;
> >
> > -	spin_lock(&rtc_lock);
> > +	spin_lock_irqsave(&rtc_lock, flags);
>
> Acked-by: Ingo Molnar <mingo@elte.hu>
>
> this bug has been in the upstream kernel for a couple of years: it was
> apparently introduced as part of HPET support, via the late_time_init()
> hook/hack in init/main.c. The lockup window is open once, during bootup.


    2.6.18-rc1-mm1, which includes this change, is printing this at
the same point I used to get the lockdep message:

[   25.628000] BUG: warning at kernel/lockdep.c:1803/trace_hardirqs_on()
[   25.628000]  [<c0104a18>] show_trace_log_lvl+0x148/0x170
[   25.628000]  [<c0105cab>] show_trace+0x1b/0x20
[   25.628000]  [<c0105cd4>] dump_stack+0x24/0x30
[   25.628000]  [<c014af4e>] trace_hardirqs_on+0xce/0x200
[   25.628000]  [<c036cf21>] _spin_unlock_irq+0x31/0x70
[   25.628000]  [<c0296584>] rtc_get_rtc_time+0x44/0x1a0
[   25.628000]  [<c01198bb>] hpet_rtc_interrupt+0x21b/0x280
[   25.628000]  [<c0161141>] handle_IRQ_event+0x31/0x70
[   25.628000]  [<c0162d37>] handle_edge_irq+0xe7/0x210
[   25.628000]  [<c0106192>] do_IRQ+0x92/0x120
[   25.628000]  [<c0104121>] common_interrupt+0x25/0x2c
[   25.628000]  [<b7f15410>] 0xb7f15410


    Updated dmesg and .config:

http://home.columbus.rr.com/jfannin3/dmesg-2.6.18-rc1-mm1
http://home.columbus.rr.com/jfannin3/config-2.6.18-rc1-mm1

--
Joseph Fannin
jhf@rivenstone.net

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