[IA64] fix kmalloc(0) in arch/ia64/pci/pci.c

Hiroyuki Kamezawa reported the problem that pci_acpi_scan_root() of
ia64 might call kmalloc_node() with zero size.

Currently ia64's pci_acpi_scan_root() assumes that _CRS method of root
bridge has at least one resource window. But, the root bridges that
has no resource window must be taken into account.

Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>

diff --git a/arch/ia64/pci/pci.c b/arch/ia64/pci/pci.c
index 3549f3b425929434fd334fd9630fc9e85ca25e68..73696b4a2eed42caafc4d7414f8ae38c6c3a6922 100644 (file)
--- a/arch/ia64/pci/pci.c
+++ b/arch/ia64/pci/pci.c
@@ -354,10 +354,13 @@ pci_acpi_scan_root(struct acpi_device *device, int domain, int bus)
 
        acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_window,
                        &windows);
-       controller->window = kmalloc_node(sizeof(*controller->window) * windows,
-                       GFP_KERNEL, controller->node);
-       if (!controller->window)
-               goto out2;
+       if (windows) {
+               controller->window =
+                       kmalloc_node(sizeof(*controller->window) * windows,
+                                    GFP_KERNEL, controller->node);
+               if (!controller->window)
+                       goto out2;
+       }
 
        name = kmalloc(16, GFP_KERNEL);
        if (!name)