ACPI: improve acpi_extract_package() utility
The current version requires one to know the size of the package
a priori; this is almost impossible if the package is composed of
strings of variable length. This change allows the utility to
allocate a buffer of the proper size if asked.
Signed-off-by: Al Stone <al.stone@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index 552248b..fc2cd32 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -169,11 +169,20 @@
/*
* Validate output buffer.
*/
- if (buffer->length < size_required) {
+ if (buffer->length == ACPI_ALLOCATE_BUFFER) {
+ buffer->pointer = ACPI_ALLOCATE(size_required);
+ if (!buffer->pointer)
+ return AE_NO_MEMORY;
buffer->length = size_required;
- return AE_BUFFER_OVERFLOW;
- } else if (buffer->length != size_required || !buffer->pointer) {
- return AE_BAD_PARAMETER;
+ memset(buffer->pointer, 0, size_required);
+ } else {
+ if (buffer->length < size_required) {
+ buffer->length = size_required;
+ return AE_BUFFER_OVERFLOW;
+ } else if (buffer->length != size_required ||
+ !buffer->pointer) {
+ return AE_BAD_PARAMETER;
+ }
}
head = buffer->pointer;