The way in which acpi_object union is being initialized varies based on
compiler type, version and flags used. Some will zero-initialize the
entire union structure and some will only initialize the first N-bytes
of the union structure. This could lead to uninitialized union members.
This bug was confirmed by observing non-zero value for object->processor
structure variables.
non-zero initialized members of acpi_object union structure causes
incorrect error reporting by the driver.
If a BIOS is using "Device" statement as opposed to "Processor"
statement, object variable may contain uninitialized members causing the
driver to report "Invalid PBLK length" incorrectly.
Using memset to zero-initialize the union structure fixes this issue and
also removes the dependency of this function on compiler versions and
flags being used.
Tested: Tested on ARM64 hardware that was printing this error and
confirmed the prints were gone.
Also confirmed this does not cause regression on ARM64 and X86
machines.
Signed-off-by: Payam Moradshahi <payamm@xxxxxxxxxx>
---
drivers/acpi/acpi_processor.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
index 7cf6101cb4c73..6696ad4937d21 100644
--- a/drivers/acpi/acpi_processor.c
+++ b/drivers/acpi/acpi_processor.c
@@ -275,7 +275,7 @@ static inline int acpi_processor_hotadd_init(struct acpi_processor *pr,
static int acpi_processor_get_info(struct acpi_device *device)
{
- union acpi_object object = { 0 };
+ union acpi_object object;
struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
struct acpi_processor *pr = acpi_driver_data(device);
int device_declaration = 0;
@@ -284,6 +284,8 @@ static int acpi_processor_get_info(struct acpi_device *device)
unsigned long long value;
int ret;
+ memset(&object, 0, sizeof(union acpi_object));
+
acpi_processor_errata();
/*
--
2.47.0.rc1.288.g06298d1525-goog
