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>

diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
index 806c44f..09bf377 100644 (file)
--- 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;