| Message ID | 02ca29627597445442bb14c069678e549429dace.camel@kernel.crashing.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Commit | 540f62d26f023a6e9c21aacb10b2f880ab2d896a |
| Headers | show |
| Series | [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal | expand |
On Mon, Jun 24, 2019 at 02:32:19PM +1000, Benjamin Herrenschmidt wrote: > pci_reassign_bridge_resources() can be called by pci_resize_resource() > at runtime. > > It will walk the PCI tree up and down, and isn't currently protected > against any changes or hotplug operation. > > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Applied to pci/resource for v5.4, thanks! > --- > > --- a/drivers/pci/setup-bus.c > +++ b/drivers/pci/setup-bus.c > @@ -2104,6 +2104,8 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > unsigned int i; > int ret; > > + down_read(&pci_bus_sem); > + > /* Walk to the root hub, releasing bridge BARs when possible */ > next = bridge; > do { > @@ -2160,6 +2162,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > } > > free_list(&saved); > + up_read(&pci_bus_sem); > return 0; > > cleanup: > @@ -2188,6 +2191,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > pci_setup_bridge(bridge->subordinate); > } > free_list(&saved); > + up_read(&pci_bus_sem); > > return ret; > } >
On Wed, Aug 21, 2019 at 08:08:27AM -0500, Bjorn Helgaas wrote: > On Mon, Jun 24, 2019 at 02:32:19PM +1000, Benjamin Herrenschmidt wrote: > > pci_reassign_bridge_resources() can be called by pci_resize_resource() > > at runtime. > > > > It will walk the PCI tree up and down, and isn't currently protected > > against any changes or hotplug operation. > > > > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> > > Applied to pci/resource for v5.4, thanks! Dropped for now per Dan's bug report: https://lore.kernel.org/r/20190904100303.GD7007@mwanda > > --- > > > > --- a/drivers/pci/setup-bus.c > > +++ b/drivers/pci/setup-bus.c > > @@ -2104,6 +2104,8 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > > unsigned int i; > > int ret; > > > > + down_read(&pci_bus_sem); > > + > > /* Walk to the root hub, releasing bridge BARs when possible */ > > next = bridge; > > do { > > @@ -2160,6 +2162,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > > } > > > > free_list(&saved); > > + up_read(&pci_bus_sem); > > return 0; > > > > cleanup: > > @@ -2188,6 +2191,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) > > pci_setup_bridge(bridge->subordinate); > > } > > free_list(&saved); > > + up_read(&pci_bus_sem); > > > > return ret; > > } > >
--- a/drivers/pci/setup-bus.c +++ b/drivers/pci/setup-bus.c @@ -2104,6 +2104,8 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) unsigned int i; int ret; + down_read(&pci_bus_sem); + /* Walk to the root hub, releasing bridge BARs when possible */ next = bridge; do { @@ -2160,6 +2162,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) } free_list(&saved); + up_read(&pci_bus_sem); return 0; cleanup: @@ -2188,6 +2191,7 @@ int pci_reassign_bridge_resources(struct pci_dev *bridge, unsigned long type) pci_setup_bridge(bridge->subordinate); } free_list(&saved); + up_read(&pci_bus_sem); return ret; }
pci_reassign_bridge_resources() can be called by pci_resize_resource() at runtime. It will walk the PCI tree up and down, and isn't currently protected against any changes or hotplug operation. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> ---