Commit fc1b2531 authored by Andreas Noever's avatar Andreas Noever Committed by Bjorn Helgaas

PCI: Don't scan random busses in pci_scan_bridge()

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 exist 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.

[bhelgaas: add parent/child bus number info to dev_warn()]
Signed-off-by: default avatarAndreas Noever <andreas.noever@gmail.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent c95b0bd6
...@@ -829,12 +829,16 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) ...@@ -829,12 +829,16 @@ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass)
goto out; goto out;
} }
if (max >= bus->busn_res.end) {
dev_warn(&dev->dev, "can't allocate child bus %02x from %pR\n",
max, &bus->busn_res);
goto out;
}
/* Clear errors */ /* Clear errors */
pci_write_config_word(dev, PCI_STATUS, 0xffff); pci_write_config_word(dev, PCI_STATUS, 0xffff);
/* Prevent assigning a bus number that already exists. /* The bus will already exist if we are rescanning */
* This can happen when a bridge is hot-plugged, so in
* this case we only re-scan this bus. */
child = pci_find_bus(pci_domain_nr(bus), max+1); child = pci_find_bus(pci_domain_nr(bus), max+1);
if (!child) { if (!child) {
child = pci_add_new_bus(bus, dev, max+1); child = pci_add_new_bus(bus, dev, max+1);
......
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