| Message ID | 1455680668-23298-32-git-send-email-gwshan@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On 02/17/2016 02:44 PM, Gavin Shan wrote: > In hotplug case, function pci_add_pci_devices() is called to rescan > the specified PCI bus, which might not have any child devices. Access > to the PCI bus's child device node will cause kernel crash without > exception. > > This adds one more check to skip scanning PCI bus that doesn't have > any subordinate devices from device-tree, in order to avoid kernel > crash. > > Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> > --- > arch/powerpc/kernel/pci-hotplug.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c > index 7929a1c..3628c38 100644 > --- a/arch/powerpc/kernel/pci-hotplug.c > +++ b/arch/powerpc/kernel/pci-hotplug.c > @@ -120,7 +120,8 @@ void pci_add_pci_devices(struct pci_bus *bus) > if (mode == PCI_PROBE_DEVTREE) { > /* use ofdt-based probe */ > of_rescan_bus(dn, bus); > - } else if (mode == PCI_PROBE_NORMAL) { > + } else if (mode == PCI_PROBE_NORMAL && > + dn->child && PCI_DN(dn->child)) { > /* > * Use legacy probe. In the partial hotplug case, we > * probably have grandchildren devices unplugged. So >
diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c index 7929a1c..3628c38 100644 --- a/arch/powerpc/kernel/pci-hotplug.c +++ b/arch/powerpc/kernel/pci-hotplug.c @@ -120,7 +120,8 @@ void pci_add_pci_devices(struct pci_bus *bus) if (mode == PCI_PROBE_DEVTREE) { /* use ofdt-based probe */ of_rescan_bus(dn, bus); - } else if (mode == PCI_PROBE_NORMAL) { + } else if (mode == PCI_PROBE_NORMAL && + dn->child && PCI_DN(dn->child)) { /* * Use legacy probe. In the partial hotplug case, we * probably have grandchildren devices unplugged. So
In hotplug case, function pci_add_pci_devices() is called to rescan the specified PCI bus, which might not have any child devices. Access to the PCI bus's child device node will cause kernel crash without exception. This adds one more check to skip scanning PCI bus that doesn't have any subordinate devices from device-tree, in order to avoid kernel crash. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> --- arch/powerpc/kernel/pci-hotplug.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)