linux-kernel - question about bgpio_remove (drivers/gpio/gpio-generic.c)

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Date:	Mon, 26 Dec 2011 18:10:32 +0100 (CET)
From:	Julia Lawall <julia.lawall@...6.fr>
To:	grant.likely@...retlab.ca, linus.walleij@...ricsson.com
cc:	linux-kernel@...r.kernel.org
Subject: question about bgpio_remove (drivers/gpio/gpio-generic.c)

The function bgpio_remove in the file drivers/gpio/gpio-generic.c is 
defind as follows:

int bgpio_remove(struct bgpio_chip *bgc)
{
         int err = gpiochip_remove(&bgc->gc);

 	kfree(bgc);

 	return err;
}
EXPORT_SYMBOL_GPL(bgpio_remove);

But bgc is allocated using devm_kzalloc, not kzalloc, and thus the kfree 
would seem to result in a dangling pointer.  On the other hand, this 
function does not have access to the information required to call 
devm_kfree (&pdev->dev).  Since the function is exported, should the 
interface be maintained, and the allocation of bgc converted to use 
kzalloc?  Or should the interface be changed to add the required 
information.  The callers in the kernel have the require information 
available.

thanks,
julia
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