Re: 2.6.33 dies on modprobe

["Américo Wang" <xiyou.wangcong@gmail.com>]

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On Wed, Mar 3, 2010 at 5:08 PM, Américo Wang <xiyou.wangcong@gmail.com> wrote:
> On Wed, Mar 3, 2010 at 4:58 PM, Américo Wang <xiyou.wangcong@gmail.com> wrote:
>> On Mon, Mar 1, 2010 at 5:07 PM, M G Berberich
>> <berberic@fmi.uni-passau.de> wrote:
>>> Hello,
>>>
>>> Am Montag, den 01. März schrieb Américo Wang:
>>>> On Mon, Mar 1, 2010 at 6:12 AM, M G Berberich
>>>> <berberic@fmi.uni-passau.de> wrote:
>>>
>>>> > I tried to build a 2.6.33 kernel but on boot it dies on modprobe
>>>> > (kernel-Oops). This might be the result of faulty config, but I'm
>>>> > totaly clueless what's the fault.
>>>> >
>>>> > The kernel starts up fine and mounts the root-filesystem, but then
>>>> > dies on the first modprobe executed. I can boot it with init=/bin/bash
>>>> > and get a working bash (until I do modprobe on any module).
>>>> >
>>>> > System is a Gigabyte M55S-S3 rev 2.0 (nForce 550) with an AMD Athlon64
>>>> > X2 5000+ and amd64-kernel architecture. kernel-sources are from
>>>> > kernel.org.
>>>
>>>> It seems something is wrong with forcedeth code or PCI code.
>>>> Adding some Cc's.
>>>
>>> I don't think it's forcedeth. forcedeth just happens to be the first
>>> module that get's loaded in startup. It crashes with any other module
>>> too (I tried ohci_hcd).
>>>
>>
>> Ok, below is my patch, I am not sure it could fix the BUG for you,
>> but it could fix the WARNING. But perhaps they are related.
>>
>> Please give it a try.
>>
>
> Oops! Ignore the patch, it should not be correct, I will send a
> correct version soon.
> Sorry.
>

Here we go:

--------------------->

It looks really odd that we do class_put() in non-failure path of
__class_register(). This seems wrong.

To fix this, just remove class_get() in __class_register(), we don't need
to call class_get() to get ref of cls->p->class_subsys, because
kset_register() has already done this for us.

Signed-off-by: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>

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diff --git a/drivers/base/class.c b/drivers/base/class.c
index 6e2c3b0..695d624 100644
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -191,8 +191,7 @@ int __class_register(struct class *cls, struct lock_class_key *key)
 		kfree(cp);
 		return error;
 	}
-	error = add_class_attrs(class_get(cls));
-	class_put(cls);
+	error = add_class_attrs(cls);
 	return error;
 }
 EXPORT_SYMBOL_GPL(__class_register);