Messages in this thread | | | Date | Mon, 3 Oct 2005 11:04:31 +0100 | From | Russell King <> | Subject | Re: [PATCH] release_resource() check for NULL resource |
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On Mon, Oct 03, 2005 at 11:59:01AM +0200, Jesper Juhl wrote: > On 10/3/05, Ben Dooks <ben-linux@fluff.org> wrote: > > On Sun, Oct 02, 2005 at 10:39:22AM -0700, Randy.Dunlap wrote: > > > On Sun, 2 Oct 2005 18:03:18 +0100 Ben Dooks wrote: > > > > > > > If release_resource() is passed a NULL resource > > > > the kernel will OOPS. > > > > > > does this actually happen? you are fixing a real oops? > > > if so, what driver caused it? > > > > I was developing a couple of new drivers, and found > > that this does not behave like kfree() which does check > > for NULL paramemters. I belive it would be helpful if > > functions like this followed the example of kfree(). > > > I would agree that it makes sense for resource release functions to be > written defensively and be able to cope with being passed a NULL > resource, just like kfree(), vfree(), crypto_free_tfm() and others are > already doing. > Seems safer and allows us to get rid of checks for NULL before calling > such functions thus making code simpler, more readable and in some > cases smaller.
I'm not convinced - release_resource() isn't like kfree() - it's more like device_unregister().
It makes sense for kfree() to ignore NULL pointers, but does it really make sense for *_unregister() to do so too? Surely you want to only unregister things which you know have previously been registered?
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core - 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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