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authorLong Li <longli@microsoft.com>2017-03-23 14:58:32 -0700
committerBjorn Helgaas <bhelgaas@google.com>2017-03-24 09:54:56 -0500
commit414428c5da1c71986727c2fa5cdf1ed071e398d7 (patch)
tree9d08139b53727f300a80b592bfae5e931634b6f8 /drivers/pci/host/pci-hyperv.c
parentd3a78d8bf759d8848339dcc367c4c1678b57a08b (diff)
PCI: hv: Lock PCI bus on device eject
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 or in create_root_hv_pci_bus(). In this case we could potentially modify the bus from multiple places. Properly lock the bus access. Thanks Dexuan Cui <decui@microsoft.com> for pointing out the race condition in create_root_hv_pci_bus(). Reported-by: Xiaofeng Wang <xiaofwan@redhat.com> Signed-off-by: Long Li <longli@microsoft.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: K. Y. Srinivasan <kys@microsoft.com>
Diffstat (limited to 'drivers/pci/host/pci-hyperv.c')
-rw-r--r--drivers/pci/host/pci-hyperv.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c
index 39fafda4deff..a1b3c1957d43 100644
--- a/drivers/pci/host/pci-hyperv.c
+++ b/drivers/pci/host/pci-hyperv.c
@@ -1209,9 +1209,11 @@ static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus)
hbus->pci_bus->msi = &hbus->msi_chip;
hbus->pci_bus->msi->dev = &hbus->hdev->device;
+ pci_lock_rescan_remove();
pci_scan_child_bus(hbus->pci_bus);
pci_bus_assign_resources(hbus->pci_bus);
pci_bus_add_devices(hbus->pci_bus);
+ pci_unlock_rescan_remove();
hbus->state = hv_pcibus_installed;
return 0;
}
@@ -1612,8 +1614,10 @@ 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_lock_rescan_remove();
pci_stop_and_remove_bus_device(pdev);
pci_dev_put(pdev);
+ pci_unlock_rescan_remove();
}
spin_lock_irqsave(&hpdev->hbus->device_list_lock, flags);