From: Erik Kaneda erik.kaneda@intel.com
[ Upstream commit 6a54ebae6d047c988a31f5ac5a64ab5cf83797a2 ]
ACPICA commit e17b28cfcc31918d0db9547b6b274b09c413eb70
Object reference counts are used as a part of ACPICA's garbage collection mechanism. This mechanism keeps track of references to heap-allocated structures such as the ACPI operand objects.
Recent server firmware has revealed that this reference count can overflow on large servers that declare many field units under the same operation_region. This occurs because each field unit declaration will add a reference count to the source operation_region.
This change solves the reference count overflow for operation_regions objects by preventing fieldunits from incrementing their operation_region's reference count. Each operation_region's reference count will not be changed by named objects declared under the Field operator. During namespace deletion, the operation_region namespace node will be deleted and each fieldunit will be deleted without touching the deleted operation_region object.
Link: https://github.com/acpica/acpica/commit/e17b28cf Signed-off-by: Erik Kaneda erik.kaneda@intel.com Signed-off-by: Bob Moore robert.moore@intel.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/acpi/acpica/exprep.c | 4 ---- drivers/acpi/acpica/utdelete.c | 6 +----- 2 files changed, 1 insertion(+), 9 deletions(-)
diff --git a/drivers/acpi/acpica/exprep.c b/drivers/acpi/acpica/exprep.c index 738f3c732363a..228feeea555f1 100644 --- a/drivers/acpi/acpica/exprep.c +++ b/drivers/acpi/acpica/exprep.c @@ -473,10 +473,6 @@ acpi_status acpi_ex_prep_field_value(struct acpi_create_field_info *info) (u8)access_byte_width; } } - /* An additional reference for the container */ - - acpi_ut_add_reference(obj_desc->field.region_obj); - ACPI_DEBUG_PRINT((ACPI_DB_BFIELD, "RegionField: BitOff %X, Off %X, Gran %X, Region %p\n", obj_desc->field.start_field_bit_offset, diff --git a/drivers/acpi/acpica/utdelete.c b/drivers/acpi/acpica/utdelete.c index 8cc4392c61f33..0dc8dea815823 100644 --- a/drivers/acpi/acpica/utdelete.c +++ b/drivers/acpi/acpica/utdelete.c @@ -563,11 +563,6 @@ acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action) next_object = object->buffer_field.buffer_obj; break;
- case ACPI_TYPE_LOCAL_REGION_FIELD: - - next_object = object->field.region_obj; - break; - case ACPI_TYPE_LOCAL_BANK_FIELD:
next_object = object->bank_field.bank_obj; @@ -608,6 +603,7 @@ acpi_ut_update_object_reference(union acpi_operand_object *object, u16 action) } break;
+ case ACPI_TYPE_LOCAL_REGION_FIELD: case ACPI_TYPE_REGION: default: