On Fri, Jul 20, 2012 at 06:18:46PM +0300, Dan Carpenter wrote:
> On Fri, Jul 20, 2012 at 08:00:42AM -0700, Greg Kroah-Hartman wrote:
> > On Fri, Jul 20, 2012 at 09:56:23AM +0300, Dan Carpenter wrote:
> > > What prompted this patch is that in dma_pool_create() we call
> > > dev_to_node() before checking whether "dev" is NULL. It looks like
> > > there are places which call dma_pool_create() with a NULL pointer. An
> > > example is in drivers/usb/gadget/amd5536udc.c.
> > >
> > > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
> > > ---
> > > Static checker fix.
> > >
> > > diff --git a/include/linux/device.h b/include/linux/device.h
> > > index aa7b3b4..c80e7a8d 100644
> > > --- a/include/linux/device.h
> > > +++ b/include/linux/device.h
> > > @@ -714,7 +714,9 @@ int dev_set_name(struct device *dev, const char *name, ...);
> > > #ifdef CONFIG_NUMA
> > > static inline int dev_to_node(struct device *dev)
> > > {
> > > - return dev->numa_node;
> > > + if (dev)
> > > + return dev->numa_node;
> > > + return -1;
> >
> > What happens if this function returns -1? Can the callers properly
> > handle this?
> >
>
> Gar. Now I'm not sure any more.
>
> -1 means no affinity and it's what the dev_to_node() returns if NUMA
> is disabled. But now I think probably it's important to get the
> NUMA node correct in dma_pool_create() so this isn't the right
> answer.
>
> dma_pool_create() is not correct. It has code to handle a NULL
> "dev" pointer, but the dev_to_node() dereference will cause an oops
> before we reach it. I'm think this is a real issue that affects a
> couple drivers. Maybe those people compile without NUMA?
>
> I'm not sure the right fix now.
Ok, I'll drop this one then.
greg k-h
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