Commit c95b0bd6 authored Jan 23, 2014 by Andreas Noever Committed by Bjorn Helgaas Feb 11, 2014

PCI: Check for child busses which use more bus numbers than allocated



pci_scan_child_bus can (potentially) return a bus number higher than the
subordinate value of the child bus. Possible reasons are that bus numbers
are reserved for SR-IOV or for CardBus (SR-IOV is done without checks and
the CardBus checks are sketchy at best).

We clamp the returned value to the actual subordinate value and print a
warning if too many bus numbers are reserved.

[bhelgaas: whitespace]
Signed-off-by: Andreas Noever <andreas.noever@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

parent f5fb4070

drivers/pci/probe.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -805,10 +805,12 @@ int pci_scan_bridge(struct pci_bus bus, struct pci_dev dev, int max, int pass)
		}

		cmax = pci_scan_child_bus(child);
		if (cmax > max)
		max = cmax;
		if (child->busn_res.end > max)
		max = child->busn_res.end;
		if (cmax > subordinate)
		dev_warn(&dev->dev, "bridge has subordinate %02x but max busn %02x\n",
		subordinate, cmax);
		/* subordinate should equal child->busn_res.end */
		if (subordinate > max)
		max = subordinate;
		} else {
		/*
		* We need to assign a number to this bus which we always