* [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal
@ 2019-06-24 4:32 Benjamin Herrenschmidt
2019-08-21 13:08 ` Bjorn Helgaas
0 siblings, 1 reply; 3+ messages in thread
From: Benjamin Herrenschmidt @ 2019-06-24 4:32 UTC (permalink / raw)
To: linux-pci@vger.kernel.org
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>
---
--- 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;
}
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal
2019-06-24 4:32 [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal Benjamin Herrenschmidt
@ 2019-08-21 13:08 ` Bjorn Helgaas
2019-09-23 21:50 ` Bjorn Helgaas
0 siblings, 1 reply; 3+ messages in thread
From: Bjorn Helgaas @ 2019-08-21 13:08 UTC (permalink / raw)
To: Benjamin Herrenschmidt; +Cc: linux-pci@vger.kernel.org
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;
> }
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal
2019-08-21 13:08 ` Bjorn Helgaas
@ 2019-09-23 21:50 ` Bjorn Helgaas
0 siblings, 0 replies; 3+ messages in thread
From: Bjorn Helgaas @ 2019-09-23 21:50 UTC (permalink / raw)
To: Benjamin Herrenschmidt; +Cc: linux-pci@vger.kernel.org
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;
> > }
> >
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-09-23 21:50 UTC | newest]
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2019-06-24 4:32 [RFC/PATCH] PCI: Protect pci_reassign_bridge_resources() against concurrent addition/removal Benjamin Herrenschmidt
2019-08-21 13:08 ` Bjorn Helgaas
2019-09-23 21:50 ` Bjorn Helgaas
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