Messages in this thread |  | | | Date | Mon, 3 Oct 2011 12:26:44 -0400 | | From | Konrad Rzeszutek Wilk <> | | Subject | Re: [Xen-devel] [PATCH 7/9] xen/xenbus: Check before dereferencing it. |
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On Fri, Sep 30, 2011 at 09:01:21AM +0100, Ian Campbell wrote: > On Thu, 2011-09-29 at 20:52 +0100, Konrad Rzeszutek Wilk wrote: > > . we do the check whether 'xdev' is NULL - but after we have > > dereferenced it. > > > > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > > --- > > drivers/xen/xenbus/xenbus_probe_backend.c | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/xen/xenbus/xenbus_probe_backend.c b/drivers/xen/xenbus/xenbus_probe_backend.c > > index 60adf91..331589a 100644 > > --- a/drivers/xen/xenbus/xenbus_probe_backend.c > > +++ b/drivers/xen/xenbus/xenbus_probe_backend.c > > @@ -103,10 +103,11 @@ static int xenbus_uevent_backend(struct device *dev, > > return -ENODEV; > > > > xdev = to_xenbus_device(dev); > > to_xenbus_device is just container_of. The only way it would return NULL > is if dev == offsetof(struct xenbus_device, dev), which isn't terribly > likely. A more likely error would be dev == NULL and we just checked > above. > > > - bus = container_of(xdev->dev.bus, struct xen_bus_type, bus); > > if (xdev == NULL) > > return -ENODEV;
Hm, in which case this 'xdev == NULL' is pointless. Will remove it.
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