> From: devel [mailto:driverdev-devel-bounces@xxxxxxxxxxxxxxxxxxxxxx] On Behalf > Of Long Li > Sent: Tuesday, September 13, 2016 7:54 > ... > A PCI_EJECT message can arrive at the same time we are calling > pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS > message, in this case we could potentailly modify the bus from two places. > Properly lock the bus access. > > --- a/drivers/pci/host/pci-hyperv.c > +++ b/drivers/pci/host/pci-hyperv.c > @@ -1587,7 +1587,7 @@ static void hv_eject_device_work(struct work_struct > *work) > pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0, > wslot); > if (pdev) { > - pci_stop_and_remove_bus_device(pdev); > + pci_stop_and_remove_bus_device_locked(pdev); > pci_dev_put(pdev); > } The _locked version tries to get the mutex pci_rescan_remove_lock. But it looks pci_scan_child_bus() doesn't try to get the mutex(?), so how can this patch make sure the 2 code paths are not running simultaneously? Thanks, -- Dexuan _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
