Re: [patch -stable] firware_class oops: fix firmware_loading_store locking

[Sachin Sant <sachinp@in.ibm.com>]

Linus Torvalds wrote:
> I don't think this is correct.
>
> I think you should protect the FW_STATUS_LOADING bit too, shouldn't you?
>
> As it is, it does this:
>
> 	if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
> 		mutex_lock(&fw_lock);
> 		...
> 		clear_bit(FW_STATUS_LOADING, &fw_priv->status);
> 		mutex_unlock(&fw_lock);
> 		break;
> 	}
>
> and if this code can race (which it obviously can, since your addition of 
> fw_lock mutex matters), then I think it can race on that FW_STATUS_LOADING 
> bit too. No?
>
> So my gut feel is that the whole damn function should be protected by the 
> mutex_lock thing. IOW, the patch would be something like the appended.
>
> UNTESTED. Somebody needs to test this, verify, and send it back to me.
>   
I did a quick boot test with this patch and didn't find any issues.

But that said i haven't been able to recreate the problem reported by Lars,
so not sure how relevant would be the test results from me.

Thanks
-Sachin


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Sachin Sant
IBM Linux Technology Center
India Systems and Technology Labs
Bangalore, India
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