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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>
This commit is contained in:
Andreas Noever 2014-01-23 21:59:27 +01:00 committed by Bjorn Helgaas
parent f5fb40700f
commit c95b0bd6ca
1 changed files with 6 additions and 4 deletions
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10
drivers/pci/probe.c
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@ -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