Re: [PATCH] usb: gadget: dummy_hcd: Fix error path

From: Alan Stern
Date: Sat Oct 02 2010 - 10:38:26 EST


On Sat, 2 Oct 2010, Alan Stern wrote:

> On Sat, 2 Oct 2010, Rahul Ruikar wrote:
>
> > In function dummy_udc_probe()
> > call put_device() when device_register() fails.
> >
> > Signed-off-by: Rahul Ruikar <rahul.ruikar@xxxxxxxxx>
> > ---
> > drivers/usb/gadget/dummy_hcd.c | 4 +++-
> > 1 files changed, 3 insertions(+), 1 deletions(-)
> >
> > diff --git a/drivers/usb/gadget/dummy_hcd.c b/drivers/usb/gadget/dummy_hcd.c
> > index dc65462..2548091 100644
> > --- a/drivers/usb/gadget/dummy_hcd.c
> > +++ b/drivers/usb/gadget/dummy_hcd.c
> > @@ -885,8 +885,10 @@ static int dummy_udc_probe (struct platform_device *pdev)
> > dum->gadget.dev.parent = &pdev->dev;
> > dum->gadget.dev.release = dummy_gadget_release;
> > rc = device_register (&dum->gadget.dev);
> > - if (rc < 0)
> > + if (rc < 0) {
> > + put_device(&dum->gadget.dev);
> > return rc;
> > + }
> >
> > usb_get_hcd (dummy_to_hcd (dum));
>
> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>

I take this back. The call usb_get_hcd needs to be moved up before the
device_register (maybe to the start of the function.) Otherwise
dummy_gadget_release would do an unbalanced usb_put_hcd.

Alan Stern

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