| Message ID | 1416869365-7671-3-git-send-email-gwshan@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Tue, 2014-11-25 at 09:49 +1100, Gavin Shan wrote: > In hotplug case, function pcibios_add_pci_devices() is called to > rescan the specified PCI bus, which possibly doesn't have any child > devices. Access to the PCI bus's child device node will cause kernel > crash without exception. The patch adds two more conditions to avoid > the kernel crash. > > Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> > --- > arch/powerpc/kernel/pci-hotplug.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c > index 6e2b4e3..ea5513b 100644 > --- a/arch/powerpc/kernel/pci-hotplug.c > +++ b/arch/powerpc/kernel/pci-hotplug.c > @@ -105,7 +105,7 @@ EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices); > * is how this routine differs from other, similar pcibios > * routines.) > */ > -void pcibios_add_pci_devices(struct pci_bus * bus) > +void pcibios_add_pci_devices(struct pci_bus *bus) Unrelated whitespace change > { > int slotno, mode, pass, max; > struct pci_dev *dev; > @@ -120,7 +120,8 @@ void pcibios_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 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Nov 26, 2014 at 09:58:02AM +1100, Benjamin Herrenschmidt wrote: >On Tue, 2014-11-25 at 09:49 +1100, Gavin Shan wrote: >> In hotplug case, function pcibios_add_pci_devices() is called to >> rescan the specified PCI bus, which possibly doesn't have any child >> devices. Access to the PCI bus's child device node will cause kernel >> crash without exception. The patch adds two more conditions to avoid >> the kernel crash. >> >> Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> >> --- >> arch/powerpc/kernel/pci-hotplug.c | 5 +++-- >> 1 file changed, 3 insertions(+), 2 deletions(-) >> >> diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c >> index 6e2b4e3..ea5513b 100644 >> --- a/arch/powerpc/kernel/pci-hotplug.c >> +++ b/arch/powerpc/kernel/pci-hotplug.c >> @@ -105,7 +105,7 @@ EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices); >> * is how this routine differs from other, similar pcibios >> * routines.) >> */ >> -void pcibios_add_pci_devices(struct pci_bus * bus) >> +void pcibios_add_pci_devices(struct pci_bus *bus) > >Unrelated whitespace change > I'll remove this change out of the patch. Thanks, Gavin >> { >> int slotno, mode, pass, max; >> struct pci_dev *dev; >> @@ -120,7 +120,8 @@ void pcibios_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 > > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/powerpc/kernel/pci-hotplug.c b/arch/powerpc/kernel/pci-hotplug.c index 6e2b4e3..ea5513b 100644 --- a/arch/powerpc/kernel/pci-hotplug.c +++ b/arch/powerpc/kernel/pci-hotplug.c @@ -105,7 +105,7 @@ EXPORT_SYMBOL_GPL(pcibios_remove_pci_devices); * is how this routine differs from other, similar pcibios * routines.) */ -void pcibios_add_pci_devices(struct pci_bus * bus) +void pcibios_add_pci_devices(struct pci_bus *bus) { int slotno, mode, pass, max; struct pci_dev *dev; @@ -120,7 +120,8 @@ void pcibios_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 pcibios_add_pci_devices() is called to rescan the specified PCI bus, which possibly doesn't have any child devices. Access to the PCI bus's child device node will cause kernel crash without exception. The patch adds two more conditions to avoid the kernel crash. Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> --- arch/powerpc/kernel/pci-hotplug.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)