> -----Original Message----- > From: Greg KH [mailto:greg@xxxxxxxxx] > Sent: Friday, October 20, 2017 8:22 AM > To: Limonciello, Mario <Mario_Limonciello@xxxxxxxx> > Cc: dvhart@xxxxxxxxxxxxx; Andy Shevchenko <andy.shevchenko@xxxxxxxxx>; > LKML <linux-kernel@xxxxxxxxxxxxxxx>; platform-driver-x86@xxxxxxxxxxxxxxx; Andy > Lutomirski <luto@xxxxxxxxxx>; quasisec@xxxxxxxxxx; pali.rohar@xxxxxxxxx; > rjw@xxxxxxxxxxxxx; mjg59@xxxxxxxxxx; hch@xxxxxx; Alan Cox > <gnomes@xxxxxxxxxxxxxxxxxxx> > Subject: Re: [PATCH v10 13/15] platform/x86: wmi: create userspace interface for > drivers > > On Thu, Oct 19, 2017 at 12:50:16PM -0500, Mario Limonciello wrote: > > + wblock = container_of(wdev, struct wmi_block, dev); > > + if (!wblock) > > + return -ENODEV; > > How can container_of() ever return NULL? If so, you have a very odd > memory layout... > I'm assuming this is from set_required_buffer_size right? The symbol is exported out for other drivers to use. It's possible for another driver to allocate a wmi_device structure that's not part of a wblock. > > + list_for_each_entry_safe(wblock, next, &wmi_block_list, list) { > > + wdriver = container_of(wblock->dev.dev.driver, > > + struct wmi_driver, driver); > > + if (!wdriver) > > + continue; > > Same here. And other places in this file. > This one it's possible that a driver isn't bound to a device, and when that happens wdriver is NULL.
