Date: Tue, 10 Nov 2009 15:15:53 -0200
From: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org,
       device@lanana.org, rubini@vision.unipv.it, gregkh@suse.de,
       cluster-devel@redhat.com
Subject: Re: [PATCH] misc: use a proper range for minor number dynamic
	allocation
Message-ID: <20091110171552.GB3628@vespa.holoscopio.com>
References: <1256340497-19320-1-git-send-email-cascardo@holoscopio.com> <20091109132836.6cf7f559.akpm@linux-foundation.org> <20091109220257.GD12217@vespa.holoscopio.com> <20091110110942.4cb70b13@lxorguk.ukuu.org.uk>
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On Tue, Nov 10, 2009 at 11:09:42AM +0000, Alan Cox wrote:
> > We could consider buggy the caller which asks for the same device name
> > more than once, without unregistering the first device. But better safe
>=20
> If they ask for the same name we certainly should. Probably we should
> error that request and use WARN_ON() to shame the offender in
> kerneloops.org.
>=20

The current code returns an error. It does not clear the bit in the
allocation bitmap, which is a bug in misc, which my first patch in the
series fixes now.

If it uses the same name, device_create is the responsible for failing.
It already logs that, but it uses no WARN right now. I think this WARN
should be in the driver core, not in misc, so we catch other offenders
as well.

> > than sorry: we should protect the correct drivers from the buggy ones
> > and avoid a depletion of the minor numbers. And, in case the driver core
> > returns another error for another reason (from device_create), we do the
> > right thing.
>=20
> Agreed we need to protect the working drivers.
>=20
> Alan

So, do you think this should be in 2.6.32 or even go down to stable?

Regards,
Cascardo.

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