Messages in this thread | | | From | eran liberty <> | Date | Wed, 25 Nov 2009 16:27:59 +0200 | Subject | Re: kobjects: mark cleaned up kobjects as unitialized |
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Hi Greg,
On Wed, Nov 25, 2009 at 2:35 PM, Greg KH <gregkh@suse.de> wrote: > On Wed, Nov 25, 2009 at 11:27:58AM +0200, eran liberty wrote: >> Hi Greg & Balaji, >> >> After diving into the LDKM and failed to spot the point where you >> actually un-initialize the 'state_initialized' of a kobject... and >> since I have statically allocated object which trip over this very >> same trap... > > Ah, there's your problem, don't statically allocate a kobject. Fix that > and your issue goes away, right?
right... but... I want to :).
Is there a Linux directive saying 'thus shall not statically allocate (or reuse in any other way) kobjects"?
> >> Google-ing for others who fell into this trap, I found your thread/patch at: >> http://lkml.org/lkml/2008/3/8/155 >> and >> http://lkml.indiana.edu/hypermail/linux/kernel/0902.0/01969.html >> >> I noticed this patch did not make it into the mainline. >> >> Is this patch still valid?
Why was your proposed patch not merged? Is there some logic behind not having it?
>> Is there some other, better way to do it by the book? > > Do not statically allocate a kobject. > >> Right now I by-pass the problem by memset-ing the whole object after I >> release it... but I feel this is a bit brutal.
Assuming I will keep it static and clear the status_initialize bit (by memset-ing the whole object) after the kobject was released... am I doing something wrong? should i expect other bad phenomena?
> > You should be freeing your memory in your release function. > Should I free the object itself in release() function? In OO-like thinking I would expect release() to be a cleanup function for the device to be used, while the kfree() be done by the same object which did the kmalloc()
> Do you have a pointer to your code somewhere? >
I will pack something and send you (i dont think Mr. vger will tolerate attachments :) ) but basically you can demonstrate the problem with this simple code:
struct device dev; while(1) { dev->release = dummy_release_function_that_does_nothing; device_register(&dev); /* will fail on second iteration without the memset!! ?? */ device_unregister(&dev); memset(&dev,0,sizeof(struct device)); /* should be unnecessary */ }
> thanks, > > greg k-h >
thanks, -- Liberty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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