PCI: acpiphp: check whether _ADR evaluation succeeded

Check whether we evaluated _ADR successfully.  Previously we ignored
failure, so we would have used garbage data from the stack as the device
and function number.

We return AE_OK so that we ignore only this slot and continue looking
for other slots.

Found by Coverity (CID 113981).

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 9 insertions, 4 deletions

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 806c44fa645a..09bf37721842 100644
--- a/drivers/pci/hotplug/acpiphp_glue.c
+++ b/drivers/pci/hotplug/acpiphp_glue.c
@@ -132,6 +132,15 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
         if (!acpi_pci_check_ejectable(pbus, handle) && !is_dock_device(handle))
                 return AE_OK;
 
+        status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
+        if (ACPI_FAILURE(status)) {
+                warn("can't evaluate _ADR (%#x)\n", status);
+                return AE_OK;
+        }
+
+        device = (adr >> 16) & 0xffff;
+        function = adr & 0xffff;
+
         pdev = pbus->self;
         if (pdev && pci_is_pcie(pdev)) {
                 tmp = acpi_find_root_bridge_handle(pdev);
@@ -144,10 +153,6 @@ register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
                 }
         }
 
-        acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
-        device = (adr >> 16) & 0xffff;
-        function = adr & 0xffff;
-
         newfunc = kzalloc(sizeof(struct acpiphp_func), GFP_KERNEL);
         if (!newfunc)
                 return AE_NO_MEMORY;