x86/PCI: fix boundary checking when using root CRS

Don't touch info->res_num if we are out of space.

Acked-by: Gary Hade <garyhade@us.ibm.com>
Tested-by: Gary Hade <garyhade@us.ibm.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 15 insertions, 12 deletions

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index b26626dc517..8bf152910eb 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -68,6 +68,10 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
         unsigned long flags;
         struct resource *root;
         int max_root_bus_resources = PCI_BUS_NUM_RESOURCES;
+        u64 start, end;
+
+        if (bus_has_transparent_bridge(info->bus))
+                max_root_bus_resources -= 3;
 
         status = resource_to_addr(acpi_res, &addr);
         if (!ACPI_SUCCESS(status))
@@ -84,25 +88,24 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
         } else
                 return AE_OK;
 
-        res = &info->res[info->res_num];
-        res->name = info->name;
-        res->flags = flags;
-        res->start = addr.minimum + addr.translation_offset;
-        res->end = res->start + addr.address_length - 1;
-        res->child = NULL;
-
-        if (bus_has_transparent_bridge(info->bus))
-                max_root_bus_resources -= 3;
+        start = addr.minimum + addr.translation_offset;
+        end = start + addr.address_length - 1;
         if (info->res_num >= max_root_bus_resources) {
                 printk(KERN_WARNING "PCI: Failed to allocate 0x%lx-0x%lx "
                         "from %s for %s due to _CRS returning more than "
-                        "%d resource descriptors\n", (unsigned long) res->start,
-                        (unsigned long) res->end, root->name, info->name,
+                        "%d resource descriptors\n", (unsigned long) start,
+                        (unsigned long) end, root->name, info->name,
                         max_root_bus_resources);
-                info->res_num++;
                 return AE_OK;
         }
 
+        res = &info->res[info->res_num];
+        res->name = info->name;
+        res->flags = flags;
+        res->start = start;
+        res->end = end;
+        res->child = NULL;
+
         if (insert_resource(root, res)) {
                 printk(KERN_ERR "PCI: Failed to allocate 0x%lx-0x%lx "
                         "from %s for %s\n", (unsigned long) res->start,