ACPICA: Add auto-serialization support for ill-behaved control methods.

This change adds support to automatically mark a control method as
"serialized" if the method creates any named objects. This will
positively prevent the method from being entered by more than one
thread and thus preventing a possible abort when an attempt is
made to create an object twice.

Implemented by parsing all non-serialize control methods at table
load time.

This feature is disabled by default and this patch also adds a new
Linux kernel parameter "acpi_auto_serialize" to allow this feature
to be turned on for a specific boot.

References: https://bugzilla.kernel.org/show_bug.cgi?id=52191
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/dsmethod.c

@@ -49,14 +49,144 @@
 #ifdef	ACPI_DISASSEMBLER
 #include "acdisasm.h"
 #endif
+#include "acparser.h"
+#include "amlcode.h"
 
 #define _COMPONENT          ACPI_DISPATCHER
 ACPI_MODULE_NAME("dsmethod")
 
 /* Local prototypes */
+static acpi_status
+acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
+			     union acpi_parse_object **out_op);
+
 static acpi_status
 acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
 
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ds_auto_serialize_method
+ *
+ * PARAMETERS:  node                        - Namespace Node of the method
+ *              obj_desc                    - Method object attached to node
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Parse a control method AML to scan for control methods that
+ *              need serialization due to the creation of named objects.
+ *
+ * NOTE: It is a bit of overkill to mark all such methods serialized, since
+ * there is only a problem if the method actually blocks during execution.
+ * A blocking operation is, for example, a Sleep() operation, or any access
+ * to an operation region. However, it is probably not possible to easily
+ * detect whether a method will block or not, so we simply mark all suspicious
+ * methods as serialized.
+ *
+ * NOTE2: This code is essentially a generic routine for parsing a single
+ * control method.
+ *
+ ******************************************************************************/
+
+acpi_status
+acpi_ds_auto_serialize_method(struct acpi_namespace_node *node,
+			      union acpi_operand_object *obj_desc)
+{
+	acpi_status status;
+	union acpi_parse_object *op = NULL;
+	struct acpi_walk_state *walk_state;
+
+	ACPI_FUNCTION_TRACE_PTR(ds_auto_serialize_method, node);
+
+	ACPI_DEBUG_PRINT((ACPI_DB_PARSE,
+			  "Method auto-serialization parse [%4.4s] %p\n",
+			  acpi_ut_get_node_name(node), node));
+
+	/* Create/Init a root op for the method parse tree */
+
+	op = acpi_ps_alloc_op(AML_METHOD_OP);
+	if (!op) {
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	acpi_ps_set_name(op, node->name.integer);
+	op->common.node = node;
+
+	/* Create and initialize a new walk state */
+
+	walk_state =
+	    acpi_ds_create_walk_state(node->owner_id, NULL, NULL, NULL);
+	if (!walk_state) {
+		return_ACPI_STATUS(AE_NO_MEMORY);
+	}
+
+	status =
+	    acpi_ds_init_aml_walk(walk_state, op, node,
+				  obj_desc->method.aml_start,
+				  obj_desc->method.aml_length, NULL, 0);
+	if (ACPI_FAILURE(status)) {
+		acpi_ds_delete_walk_state(walk_state);
+		return_ACPI_STATUS(status);
+	}
+
+	walk_state->descending_callback = acpi_ds_detect_named_opcodes;
+
+	/* Parse the method, scan for creation of named objects */
+
+	status = acpi_ps_parse_aml(walk_state);
+	if (ACPI_FAILURE(status)) {
+		return_ACPI_STATUS(status);
+	}
+
+	acpi_ps_delete_parse_tree(op);
+	return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_ds_detect_named_opcodes
+ *
+ * PARAMETERS:  walk_state      - Current state of the parse tree walk
+ *              out_op          - Unused, required for parser interface
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Descending callback used during the loading of ACPI tables.
+ *              Currently used to detect methods that must be marked serialized
+ *              in order to avoid problems with the creation of named objects.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_ds_detect_named_opcodes(struct acpi_walk_state *walk_state,
+			     union acpi_parse_object **out_op)
+{
+
+	ACPI_FUNCTION_NAME(acpi_ds_detect_named_opcodes);
+
+	/* We are only interested in opcodes that have an associated name */
+
+	if (!(walk_state->op_info->flags & AML_NAMED)) {
+		return (AE_OK);
+	}
+
+	/*
+	 * At this point, we know we have a Named object opcode.
+	 * Mark the method as serialized. Later code will create a mutex for
+	 * this method to enforce serialization.
+	 */
+	walk_state->method_desc->method.info_flags |= ACPI_METHOD_SERIALIZED;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO,
+			  "Method serialized [%4.4s] %p - [%s] (%4.4X)\n",
+			  walk_state->method_node->name.ascii,
+			  walk_state->method_node, walk_state->op_info->name,
+			  walk_state->opcode));
+
+	/* Abort the parse, no need to examine this method any further */
+
+	return (AE_CTRL_TERMINATE);
+}
+
 /*******************************************************************************
  *
  * FUNCTION:    acpi_ds_method_error
@@ -74,7 +204,7 @@ acpi_ds_create_method_mutex(union acpi_operand_object *method_desc);
  ******************************************************************************/
 
 acpi_status
-acpi_ds_method_error(acpi_status status, struct acpi_walk_state *walk_state)
+acpi_ds_method_error(acpi_status status, struct acpi_walk_state * walk_state)
 {
 	ACPI_FUNCTION_ENTRY();