Re: 2.6.33 dies on modprobe

From: Andrew Morton
Date: Wed Mar 03 2010 - 17:24:44 EST


On Wed, 3 Mar 2010 23:16:02 +0100
M G Berberich <berberic@xxxxxxxxxxxxxxxxx> wrote:

> Hello,
>
> Am Dienstag, den 02. M__rz schrieb Andrew Morton:
>
> > It could be that some kobject on that list has become invalid (memory
> > was freed, module was unloaded, etc) and later code stumbled across the
> > now-invalid object on that list and then crashed.
> >
> > What we can do to find this is to add a diagnostic each time an object
> > is registered, and a diagnostic each time kset_find_obj() looks at the
> > objects. Then we'll see which kobject caused the crash, then we can
> > look back and see where that kobject was registered from.
>
> [...]
>
> > This will generate a lot of output and we don't want to lose any of it.
> > I'd suggest setting up netconsole so all the output can be reliably
> > saved: Documentation/networking/netconsole.txt
>
> I have a serial connection to a netbook. Log attached.

drat, my patch didn't work. Can you try this one please?

--- a/lib/kobject.c~a
+++ a/lib/kobject.c
@@ -126,6 +126,8 @@ static void kobj_kset_join(struct kobjec

kset_get(kobj->kset);
spin_lock(&kobj->kset->list_lock);
+ printk("kobj_kset_join:%p\n", kobj);
+ dump_stack();
list_add_tail(&kobj->entry, &kobj->kset->list);
spin_unlock(&kobj->kset->list_lock);
}
@@ -751,9 +753,12 @@ struct kobject *kset_find_obj(struct kse

spin_lock(&kset->list_lock);
list_for_each_entry(k, &kset->list, entry) {
- if (kobject_name(k) && !strcmp(kobject_name(k), name)) {
- ret = kobject_get(k);
- break;
+ if (kobject_name(k)) {
+ printk("kset_find_obj:%p\n", k);
+ if (!strcmp(kobject_name(k), name)) {
+ ret = kobject_get(k);
+ break;
+ }
}
}
spin_unlock(&kset->list_lock);
_

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