When assigning a new bus number in pci_scan_bridge we check whether max+1 is free by calling pci_find_bus. If it does already exists then we assume that we are rescanning and that this is the right bus to scan.
This is fragile. If max+1 lies outside of bus->busn_res.end then we will rescan some random bus from somewhere else in the hierachy. This patch checks for this case and prints a warning. Signed-off-by: Andreas Noever <[email protected]> --- drivers/pci/probe.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 74bc644..0a94de2 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -830,12 +830,16 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) goto out; } + if (max >= bus->busn_res.end) { + dev_warn(&dev->dev, + "parent bus ran out of bus numbers, cannot allocate child bus\n"); + goto out; + } + /* Clear errors */ pci_write_config_word(dev, PCI_STATUS, 0xffff); - /* Prevent assigning a bus number that already exists. - * This can happen when a bridge is hot-plugged, so in - * this case we only re-scan this bus. */ + /* The bus will already exist if we are rescanning */ child = pci_find_bus(pci_domain_nr(bus), max+1); if (!child) { child = pci_add_new_bus(bus, dev, max+1); -- 1.8.5.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
