ACPICA: Additional error checking for pathname utilities

Add error check after all calls to acpi_ns_get_pathname_length.
Add status return from acpi_ns_build_external_path and check after
all calls.  Add parameter validation to acpi_ut_initialize_buffer.

Reported by and initial patch by Ingo Molnar.
http://lkml.org/lkml/2008/7/21/176

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
diff --git a/drivers/acpi/resources/rscalc.c b/drivers/acpi/resources/rscalc.c
index f61ebc6..d9063ea 100644
--- a/drivers/acpi/resources/rscalc.c
+++ b/drivers/acpi/resources/rscalc.c
@@ -587,6 +587,9 @@
 			} else {
 				temp_size_needed +=
 				    acpi_ns_get_pathname_length((*sub_object_list)->reference.node);
+				if (!temp_size_needed) {
+					return_ACPI_STATUS(AE_BAD_PARAMETER);
+				}
 			}
 		} else {
 			/*