On Fri, 26 May 2017 18:47:26 -0500, Bjorn Helgaas wrote: > On Mon, May 22, 2017 at 03:50:23PM -0700, Jakub Kicinski wrote: > > PCI core sets the driver pointer before calling ->probe() and only > > clears it after ->remove(). This means driver's ->sriov_configure() > > callback will happily race with probe() and remove(), most likely > > leading to BUGs, since drivers don't expect this. > > I guess you're referring to the pci_dev->driver pointer set by > local_pci_probe(), and this is important because sriov_numvfs_store() > checks that pointer, right? Yes, exactly. I initially thought this is how the safety of sriov callback may have been ensured, but since the order of local_pci_probe() and the assignment is what it is, it can't.