Re: [PATCH 3.14 30/59] xhci: refuse loading if nousb is used - Greg Kroah-Hartman

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Luis Henriques <luis.henriques@canonical.com>
Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org,
	Oliver Neukum <oneukum@suse.com>
Subject: Re: [PATCH 3.14 30/59] xhci: refuse loading if nousb is used
Date: Sun, 31 Jan 2016 11:10:14 -0800	[thread overview]
Message-ID: <20160131191014.GA23698@kroah.com> (raw)
In-Reply-To: <20160128175735.GB30680@charon.olymp>

On Thu, Jan 28, 2016 at 05:57:35PM +0000, Luis Henriques wrote:
> On Wed, Jan 27, 2016 at 10:15:18AM -0800, Greg Kroah-Hartman wrote:
> > 3.14-stable review patch.  If anyone has any objections, please let me know.
> > 
> > ------------------
> > 
> > From: Oliver Neukum <oneukum@suse.com>
> > 
> > commit 1eaf35e4dd592c59041bc1ed3248c46326da1f5f upstream.
> > 
> > The module should fail to load.
> > 
> > Signed-off-by: Oliver Neukum <oneukum@suse.com>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > 
> > ---
> >  drivers/usb/host/xhci.c |    4 ++++
> >  1 file changed, 4 insertions(+)
> > 
> > --- a/drivers/usb/host/xhci.c
> > +++ b/drivers/usb/host/xhci.c
> > @@ -4893,6 +4893,10 @@ static int __init xhci_hcd_init(void)
> >  	BUILD_BUG_ON(sizeof(struct xhci_intr_reg) != 8*32/8);
> >  	/* xhci_run_regs has eight fields and embeds 128 xhci_intr_regs */
> >  	BUILD_BUG_ON(sizeof(struct xhci_run_regs) != (8+8*128)*32/8);
> > +
> > +	if (usb_disabled())
> > +		return -ENODEV;
> > +
> 
> I believe the error path should actually call xhci_unregister_pci().
> Something like the patch below.  The same is applies to the 3.10
> kernel.
> 
> Cheers,
> --
> Luís
> 
> >  	return 0;
> >  unreg_pci:
> >  	xhci_unregister_pci();
> > 
> > 
> > --
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> 
> >From 870b9e9479b67df493e2ca3c763102b10d4dd9da Mon Sep 17 00:00:00 2001
> From: Oliver Neukum <oneukum@suse.com>
> Date: Thu, 3 Dec 2015 15:03:34 +0100
> Subject: xhci: refuse loading if nousb is used
> 
> commit 1eaf35e4dd592c59041bc1ed3248c46326da1f5f upstream.
> 
> The module should fail to load.
> 
> Signed-off-by: Oliver Neukum <oneukum@suse.com>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> [ luis: need to call xhci_unregister_pci() in the error path ]
> Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
> ---
>  drivers/usb/host/xhci.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 20209e870a99..4c78dc564b3a 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -4955,6 +4955,12 @@ static int __init xhci_hcd_init(void)
>  	BUILD_BUG_ON(sizeof(struct xhci_intr_reg) != 8*32/8);
>  	/* xhci_run_regs has eight fields and embeds 128 xhci_intr_regs */
>  	BUILD_BUG_ON(sizeof(struct xhci_run_regs) != (8+8*128)*32/8);
> +
> +	if (usb_disabled()) {
> +		retval = -ENODEV;
> +		goto unreg_pci;
> +	}

No, we should move the check much higher up to the top of the function,
which makes it simpler.  I'll go do that instead, thanks.

greg k-h