Re: v2.6.25: WARNING: at kernel/lockdep.c:2437 __lock_acquire+0xc69/0xfa0()

[Jeff Garzik]

Tejun Heo wrote:
> Peter Zijlstra wrote:
> > Indeed, quite easy to reproduce:
> >
> > diff --git a/kernel/lockdep.c b/kernel/lockdep.c
> > index 81a4e4a..33901ef 100644
> > --- a/kernel/lockdep.c
> > +++ b/kernel/lockdep.c
> > @@ -2434,6 +2434,13 @@ static int __lock_acquire(struct lockdep_map 
> > *lock, unsigned int subclass,
> >       * the hash, not class->key.
> >       */
> >      id = class - lock_classes;
> > +    if (id >= MAX_LOCKDEP_KEYS) {
> > +        spinlock_t *slock = container_of(lock, spinlock_t, dep_map);
> > +
> > +        printk(KERN_EMERG "magic: %x\n", slock->magic);
> > +        printk(KERN_EMERG "class: %p\n", class);
> > +        printk(KERN_EMERG "id: %u\n", id);
> > +    }
> >      if (DEBUG_LOCKS_WARN_ON(id >= MAX_LOCKDEP_KEYS))
> >          return 0;
> >  
> >
> >
> > gives me:
> >
> > ata3: PATA max PIO4 cmd 0x1e8 ctl 0x3ee irq 11
> > magic: c050cf60
> > class: c7c20e54
> > id: 2265185251
> > ------------[ cut here ]------------
> > WARNING: at /mnt/md0/src/linux-2.6-2/kernel/lockdep.c:2444
> > __lock_acquire+0x57b/0xfd0()
> >
> >
> > Looks like someone is stomping on the spinlock or just passing us
> > garbage.
>
> Does the attached patch help?
>
> diff --git a/drivers/ata/pata_legacy.c b/drivers/ata/pata_legacy.c
> index 7af4b29..f7ba234 100644
> --- a/drivers/ata/pata_legacy.c
> +++ b/drivers/ata/pata_legacy.c
> @@ -1037,6 +1037,7 @@ static __init int legacy_init_one(struct legacy_probe *probe)
>  			return 0;
>  		}
>  	}
> +	ata_host_detach(host);
>  fail:
>  	platform_device_unregister(pdev);
>  	return ret;


(going through old, unresolved email)

It looks like this might still be needed?  I never saw an "it works" 
response to this email.

	Jeff



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