Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 875 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/dbexec.c b/drivers/acpi/acpica/dbexec.c
new file mode 100644
index 000000000..d3a9521e2
--- /dev/null
+++ b/drivers/acpi/acpica/dbexec.c
@@ -0,0 +1,875 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/*******************************************************************************
+ *
+ * Module Name: dbexec - debugger control method execution
+ *
+ ******************************************************************************/
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "acdebug.h"
+#include "acnamesp.h"
+
+#define _COMPONENT          ACPI_CA_DEBUGGER
+ACPI_MODULE_NAME("dbexec")
+
+static struct acpi_db_method_info acpi_gbl_db_method_info;
+
+/* Local prototypes */
+
+static acpi_status
+acpi_db_execute_method(struct acpi_db_method_info *info,
+		       struct acpi_buffer *return_obj);
+
+static acpi_status acpi_db_execute_setup(struct acpi_db_method_info *info);
+
+static u32 acpi_db_get_outstanding_allocations(void);
+
+static void ACPI_SYSTEM_XFACE acpi_db_method_thread(void *context);
+
+static acpi_status
+acpi_db_execution_walk(acpi_handle obj_handle,
+		       u32 nesting_level, void *context, void **return_value);
+
+static void ACPI_SYSTEM_XFACE acpi_db_single_execution_thread(void *context);
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_delete_objects
+ *
+ * PARAMETERS:  count               - Count of objects in the list
+ *              objects             - Array of ACPI_OBJECTs to be deleted
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Delete a list of ACPI_OBJECTS. Handles packages and nested
+ *              packages via recursion.
+ *
+ ******************************************************************************/
+
+void acpi_db_delete_objects(u32 count, union acpi_object *objects)
+{
+	u32 i;
+
+	for (i = 0; i < count; i++) {
+		switch (objects[i].type) {
+		case ACPI_TYPE_BUFFER:
+
+			ACPI_FREE(objects[i].buffer.pointer);
+			break;
+
+		case ACPI_TYPE_PACKAGE:
+
+			/* Recursive call to delete package elements */
+
+			acpi_db_delete_objects(objects[i].package.count,
+					       objects[i].package.elements);
+
+			/* Free the elements array */
+
+			ACPI_FREE(objects[i].package.elements);
+			break;
+
+		default:
+
+			break;
+		}
+	}
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_execute_method
+ *
+ * PARAMETERS:  info            - Valid info segment
+ *              return_obj      - Where to put return object
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Execute a control method. Used to evaluate objects via the
+ *              "EXECUTE" or "EVALUATE" commands.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_db_execute_method(struct acpi_db_method_info *info,
+		       struct acpi_buffer *return_obj)
+{
+	acpi_status status;
+	struct acpi_object_list param_objects;
+	union acpi_object params[ACPI_DEBUGGER_MAX_ARGS + 1];
+	u32 i;
+
+	ACPI_FUNCTION_TRACE(db_execute_method);
+
+	if (acpi_gbl_db_output_to_file && !acpi_dbg_level) {
+		acpi_os_printf("Warning: debug output is not enabled!\n");
+	}
+
+	param_objects.count = 0;
+	param_objects.pointer = NULL;
+
+	/* Pass through any command-line arguments */
+
+	if (info->args && info->args[0]) {
+
+		/* Get arguments passed on the command line */
+
+		for (i = 0; (info->args[i] && *(info->args[i])); i++) {
+
+			/* Convert input string (token) to an actual union acpi_object */
+
+			status = acpi_db_convert_to_object(info->types[i],
+							   info->args[i],
+							   &params[i]);
+			if (ACPI_FAILURE(status)) {
+				ACPI_EXCEPTION((AE_INFO, status,
+						"While parsing method arguments"));
+				goto cleanup;
+			}
+		}
+
+		param_objects.count = i;
+		param_objects.pointer = params;
+	}
+
+	/* Prepare for a return object of arbitrary size */
+
+	return_obj->pointer = acpi_gbl_db_buffer;
+	return_obj->length = ACPI_DEBUG_BUFFER_SIZE;
+
+	/* Do the actual method execution */
+
+	acpi_gbl_method_executing = TRUE;
+	status = acpi_evaluate_object(NULL, info->pathname,
+				      &param_objects, return_obj);
+
+	acpi_gbl_cm_single_step = FALSE;
+	acpi_gbl_method_executing = FALSE;
+
+	if (ACPI_FAILURE(status)) {
+		if ((status == AE_ABORT_METHOD) || acpi_gbl_abort_method) {
+
+			/* Clear the abort and fall back to the debugger prompt */
+
+			ACPI_EXCEPTION((AE_INFO, status,
+					"Aborting top-level method"));
+
+			acpi_gbl_abort_method = FALSE;
+			status = AE_OK;
+			goto cleanup;
+		}
+
+		ACPI_EXCEPTION((AE_INFO, status,
+				"while executing %s from AML Debugger",
+				info->pathname));
+
+		if (status == AE_BUFFER_OVERFLOW) {
+			ACPI_ERROR((AE_INFO,
+				    "Possible buffer overflow within AML Debugger "
+				    "buffer (size 0x%X needed 0x%X)",
+				    ACPI_DEBUG_BUFFER_SIZE,
+				    (u32)return_obj->length));
+		}
+	}
+
+cleanup:
+	acpi_db_delete_objects(param_objects.count, params);
+	return_ACPI_STATUS(status);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_execute_setup
+ *
+ * PARAMETERS:  info            - Valid method info
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Setup info segment prior to method execution
+ *
+ ******************************************************************************/
+
+static acpi_status acpi_db_execute_setup(struct acpi_db_method_info *info)
+{
+	acpi_status status;
+
+	ACPI_FUNCTION_NAME(db_execute_setup);
+
+	/* Concatenate the current scope to the supplied name */
+
+	info->pathname[0] = 0;
+	if ((info->name[0] != '\\') && (info->name[0] != '/')) {
+		if (acpi_ut_safe_strcat(info->pathname, sizeof(info->pathname),
+					acpi_gbl_db_scope_buf)) {
+			status = AE_BUFFER_OVERFLOW;
+			goto error_exit;
+		}
+	}
+
+	if (acpi_ut_safe_strcat(info->pathname, sizeof(info->pathname),
+				info->name)) {
+		status = AE_BUFFER_OVERFLOW;
+		goto error_exit;
+	}
+
+	acpi_db_prep_namestring(info->pathname);
+
+	acpi_db_set_output_destination(ACPI_DB_DUPLICATE_OUTPUT);
+	acpi_os_printf("Evaluating %s\n", info->pathname);
+
+	if (info->flags & EX_SINGLE_STEP) {
+		acpi_gbl_cm_single_step = TRUE;
+		acpi_db_set_output_destination(ACPI_DB_CONSOLE_OUTPUT);
+	}
+
+	else {
+		/* No single step, allow redirection to a file */
+
+		acpi_db_set_output_destination(ACPI_DB_REDIRECTABLE_OUTPUT);
+	}
+
+	return (AE_OK);
+
+error_exit:
+
+	ACPI_EXCEPTION((AE_INFO, status, "During setup for method execution"));
+	return (status);
+}
+
+#ifdef ACPI_DBG_TRACK_ALLOCATIONS
+u32 acpi_db_get_cache_info(struct acpi_memory_list *cache)
+{
+
+	return (cache->total_allocated - cache->total_freed -
+		cache->current_depth);
+}
+#endif
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_get_outstanding_allocations
+ *
+ * PARAMETERS:  None
+ *
+ * RETURN:      Current global allocation count minus cache entries
+ *
+ * DESCRIPTION: Determine the current number of "outstanding" allocations --
+ *              those allocations that have not been freed and also are not
+ *              in one of the various object caches.
+ *
+ ******************************************************************************/
+
+static u32 acpi_db_get_outstanding_allocations(void)
+{
+	u32 outstanding = 0;
+
+#ifdef ACPI_DBG_TRACK_ALLOCATIONS
+
+	outstanding += acpi_db_get_cache_info(acpi_gbl_state_cache);
+	outstanding += acpi_db_get_cache_info(acpi_gbl_ps_node_cache);
+	outstanding += acpi_db_get_cache_info(acpi_gbl_ps_node_ext_cache);
+	outstanding += acpi_db_get_cache_info(acpi_gbl_operand_cache);
+#endif
+
+	return (outstanding);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_execution_walk
+ *
+ * PARAMETERS:  WALK_CALLBACK
+ *
+ * RETURN:      Status
+ *
+ * DESCRIPTION: Execute a control method. Name is relative to the current
+ *              scope.
+ *
+ ******************************************************************************/
+
+static acpi_status
+acpi_db_execution_walk(acpi_handle obj_handle,
+		       u32 nesting_level, void *context, void **return_value)
+{
+	union acpi_operand_object *obj_desc;
+	struct acpi_namespace_node *node =
+	    (struct acpi_namespace_node *)obj_handle;
+	struct acpi_buffer return_obj;
+	acpi_status status;
+
+	obj_desc = acpi_ns_get_attached_object(node);
+	if (obj_desc->method.param_count) {
+		return (AE_OK);
+	}
+
+	return_obj.pointer = NULL;
+	return_obj.length = ACPI_ALLOCATE_BUFFER;
+
+	acpi_ns_print_node_pathname(node, "Evaluating");
+
+	/* Do the actual method execution */
+
+	acpi_os_printf("\n");
+	acpi_gbl_method_executing = TRUE;
+
+	status = acpi_evaluate_object(node, NULL, NULL, &return_obj);
+
+	acpi_gbl_method_executing = FALSE;
+
+	acpi_os_printf("Evaluation of [%4.4s] returned %s\n",
+		       acpi_ut_get_node_name(node),
+		       acpi_format_exception(status));
+
+	return (AE_OK);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_execute
+ *
+ * PARAMETERS:  name                - Name of method to execute
+ *              args                - Parameters to the method
+ *              Types               -
+ *              flags               - single step/no single step
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Execute a control method. Name is relative to the current
+ *              scope. Function used for the "EXECUTE", "EVALUATE", and
+ *              "ALL" commands
+ *
+ ******************************************************************************/
+
+void
+acpi_db_execute(char *name, char **args, acpi_object_type *types, u32 flags)
+{
+	acpi_status status;
+	struct acpi_buffer return_obj;
+	char *name_string;
+
+#ifdef ACPI_DEBUG_OUTPUT
+	u32 previous_allocations;
+	u32 allocations;
+#endif
+
+	/*
+	 * Allow one execution to be performed by debugger or single step
+	 * execution will be dead locked by the interpreter mutexes.
+	 */
+	if (acpi_gbl_method_executing) {
+		acpi_os_printf("Only one debugger execution is allowed.\n");
+		return;
+	}
+#ifdef ACPI_DEBUG_OUTPUT
+	/* Memory allocation tracking */
+
+	previous_allocations = acpi_db_get_outstanding_allocations();
+#endif
+
+	if (*name == '*') {
+		(void)acpi_walk_namespace(ACPI_TYPE_METHOD, ACPI_ROOT_OBJECT,
+					  ACPI_UINT32_MAX,
+					  acpi_db_execution_walk, NULL, NULL,
+					  NULL);
+		return;
+	}
+
+	if ((flags & EX_ALL) && (strlen(name) > 4)) {
+		acpi_os_printf("Input name (%s) must be a 4-char NameSeg\n",
+			       name);
+		return;
+	}
+
+	name_string = ACPI_ALLOCATE(strlen(name) + 1);
+	if (!name_string) {
+		return;
+	}
+
+	memset(&acpi_gbl_db_method_info, 0, sizeof(struct acpi_db_method_info));
+	strcpy(name_string, name);
+	acpi_ut_strupr(name_string);
+
+	/* Subcommand to Execute all predefined names in the namespace */
+
+	if (!strncmp(name_string, "PREDEF", 6)) {
+		acpi_db_evaluate_predefined_names();
+		ACPI_FREE(name_string);
+		return;
+	}
+
+	/* Command (ALL <nameseg>) to execute all methods of a particular name */
+
+	else if (flags & EX_ALL) {
+		acpi_gbl_db_method_info.name = name_string;
+		return_obj.pointer = NULL;
+		return_obj.length = ACPI_ALLOCATE_BUFFER;
+		acpi_db_evaluate_all(name_string);
+		ACPI_FREE(name_string);
+		return;
+	} else {
+		acpi_gbl_db_method_info.name = name_string;
+		acpi_gbl_db_method_info.args = args;
+		acpi_gbl_db_method_info.types = types;
+		acpi_gbl_db_method_info.flags = flags;
+
+		return_obj.pointer = NULL;
+		return_obj.length = ACPI_ALLOCATE_BUFFER;
+	}
+
+	status = acpi_db_execute_setup(&acpi_gbl_db_method_info);
+	if (ACPI_FAILURE(status)) {
+		ACPI_FREE(name_string);
+		return;
+	}
+
+	/* Get the NS node, determines existence also */
+
+	status = acpi_get_handle(NULL, acpi_gbl_db_method_info.pathname,
+				 &acpi_gbl_db_method_info.method);
+	if (ACPI_SUCCESS(status)) {
+		status = acpi_db_execute_method(&acpi_gbl_db_method_info,
+						&return_obj);
+	}
+	ACPI_FREE(name_string);
+
+	/*
+	 * Allow any handlers in separate threads to complete.
+	 * (Such as Notify handlers invoked from AML executed above).
+	 */
+	acpi_os_sleep((u64)10);
+
+#ifdef ACPI_DEBUG_OUTPUT
+
+	/* Memory allocation tracking */
+
+	allocations =
+	    acpi_db_get_outstanding_allocations() - previous_allocations;
+
+	acpi_db_set_output_destination(ACPI_DB_DUPLICATE_OUTPUT);
+
+	if (allocations > 0) {
+		acpi_os_printf
+		    ("0x%X Outstanding allocations after evaluation of %s\n",
+		     allocations, acpi_gbl_db_method_info.pathname);
+	}
+#endif
+
+	if (ACPI_FAILURE(status)) {
+		acpi_os_printf("Evaluation of %s failed with status %s\n",
+			       acpi_gbl_db_method_info.pathname,
+			       acpi_format_exception(status));
+	} else {
+		/* Display a return object, if any */
+
+		if (return_obj.length) {
+			acpi_os_printf("Evaluation of %s returned object %p, "
+				       "external buffer length %X\n",
+				       acpi_gbl_db_method_info.pathname,
+				       return_obj.pointer,
+				       (u32)return_obj.length);
+
+			acpi_db_dump_external_object(return_obj.pointer, 1);
+			acpi_os_printf("\n");
+
+			/* Dump a _PLD buffer if present */
+
+			if (ACPI_COMPARE_NAMESEG
+			    ((ACPI_CAST_PTR
+			      (struct acpi_namespace_node,
+			       acpi_gbl_db_method_info.method)->name.ascii),
+			     METHOD_NAME__PLD)) {
+				acpi_db_dump_pld_buffer(return_obj.pointer);
+			}
+		} else {
+			acpi_os_printf
+			    ("No object was returned from evaluation of %s\n",
+			     acpi_gbl_db_method_info.pathname);
+		}
+	}
+
+	acpi_db_set_output_destination(ACPI_DB_CONSOLE_OUTPUT);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_method_thread
+ *
+ * PARAMETERS:  context             - Execution info segment
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Debugger execute thread. Waits for a command line, then
+ *              simply dispatches it.
+ *
+ ******************************************************************************/
+
+static void ACPI_SYSTEM_XFACE acpi_db_method_thread(void *context)
+{
+	acpi_status status;
+	struct acpi_db_method_info *info = context;
+	struct acpi_db_method_info local_info;
+	u32 i;
+	u8 allow;
+	struct acpi_buffer return_obj;
+
+	/*
+	 * acpi_gbl_db_method_info.Arguments will be passed as method arguments.
+	 * Prevent acpi_gbl_db_method_info from being modified by multiple threads
+	 * concurrently.
+	 *
+	 * Note: The arguments we are passing are used by the ASL test suite
+	 * (aslts). Do not change them without updating the tests.
+	 */
+	(void)acpi_os_wait_semaphore(info->info_gate, 1, ACPI_WAIT_FOREVER);
+
+	if (info->init_args) {
+		acpi_db_uint32_to_hex_string(info->num_created,
+					     info->index_of_thread_str);
+		acpi_db_uint32_to_hex_string((u32)acpi_os_get_thread_id(),
+					     info->id_of_thread_str);
+	}
+
+	if (info->threads && (info->num_created < info->num_threads)) {
+		info->threads[info->num_created++] = acpi_os_get_thread_id();
+	}
+
+	local_info = *info;
+	local_info.args = local_info.arguments;
+	local_info.arguments[0] = local_info.num_threads_str;
+	local_info.arguments[1] = local_info.id_of_thread_str;
+	local_info.arguments[2] = local_info.index_of_thread_str;
+	local_info.arguments[3] = NULL;
+
+	local_info.types = local_info.arg_types;
+
+	(void)acpi_os_signal_semaphore(info->info_gate, 1);
+
+	for (i = 0; i < info->num_loops; i++) {
+		status = acpi_db_execute_method(&local_info, &return_obj);
+		if (ACPI_FAILURE(status)) {
+			acpi_os_printf
+			    ("%s During evaluation of %s at iteration %X\n",
+			     acpi_format_exception(status), info->pathname, i);
+			if (status == AE_ABORT_METHOD) {
+				break;
+			}
+		}
+#if 0
+		if ((i % 100) == 0) {
+			acpi_os_printf("%u loops, Thread 0x%x\n",
+				       i, acpi_os_get_thread_id());
+		}
+
+		if (return_obj.length) {
+			acpi_os_printf
+			    ("Evaluation of %s returned object %p Buflen %X\n",
+			     info->pathname, return_obj.pointer,
+			     (u32)return_obj.length);
+			acpi_db_dump_external_object(return_obj.pointer, 1);
+		}
+#endif
+	}
+
+	/* Signal our completion */
+
+	allow = 0;
+	(void)acpi_os_wait_semaphore(info->thread_complete_gate,
+				     1, ACPI_WAIT_FOREVER);
+	info->num_completed++;
+
+	if (info->num_completed == info->num_threads) {
+
+		/* Do signal for main thread once only */
+		allow = 1;
+	}
+
+	(void)acpi_os_signal_semaphore(info->thread_complete_gate, 1);
+
+	if (allow) {
+		status = acpi_os_signal_semaphore(info->main_thread_gate, 1);
+		if (ACPI_FAILURE(status)) {
+			acpi_os_printf
+			    ("Could not signal debugger thread sync semaphore, %s\n",
+			     acpi_format_exception(status));
+		}
+	}
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_single_execution_thread
+ *
+ * PARAMETERS:  context                 - Method info struct
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Create one thread and execute a method
+ *
+ ******************************************************************************/
+
+static void ACPI_SYSTEM_XFACE acpi_db_single_execution_thread(void *context)
+{
+	struct acpi_db_method_info *info = context;
+	acpi_status status;
+	struct acpi_buffer return_obj;
+
+	acpi_os_printf("\n");
+
+	status = acpi_db_execute_method(info, &return_obj);
+	if (ACPI_FAILURE(status)) {
+		acpi_os_printf("%s During evaluation of %s\n",
+			       acpi_format_exception(status), info->pathname);
+		return;
+	}
+
+	/* Display a return object, if any */
+
+	if (return_obj.length) {
+		acpi_os_printf("Evaluation of %s returned object %p, "
+			       "external buffer length %X\n",
+			       acpi_gbl_db_method_info.pathname,
+			       return_obj.pointer, (u32)return_obj.length);
+
+		acpi_db_dump_external_object(return_obj.pointer, 1);
+	}
+
+	acpi_os_printf("\nBackground thread completed\n%c ",
+		       ACPI_DEBUGGER_COMMAND_PROMPT);
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_create_execution_thread
+ *
+ * PARAMETERS:  method_name_arg         - Control method to execute
+ *              arguments               - Array of arguments to the method
+ *              types                   - Corresponding array of object types
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Create a single thread to evaluate a namespace object. Handles
+ *              arguments passed on command line for control methods.
+ *
+ ******************************************************************************/
+
+void
+acpi_db_create_execution_thread(char *method_name_arg,
+				char **arguments, acpi_object_type *types)
+{
+	acpi_status status;
+	u32 i;
+
+	memset(&acpi_gbl_db_method_info, 0, sizeof(struct acpi_db_method_info));
+	acpi_gbl_db_method_info.name = method_name_arg;
+	acpi_gbl_db_method_info.init_args = 1;
+	acpi_gbl_db_method_info.args = acpi_gbl_db_method_info.arguments;
+	acpi_gbl_db_method_info.types = acpi_gbl_db_method_info.arg_types;
+
+	/* Setup method arguments, up to 7 (0-6) */
+
+	for (i = 0; (i < ACPI_METHOD_NUM_ARGS) && *arguments; i++) {
+		acpi_gbl_db_method_info.arguments[i] = *arguments;
+		arguments++;
+
+		acpi_gbl_db_method_info.arg_types[i] = *types;
+		types++;
+	}
+
+	status = acpi_db_execute_setup(&acpi_gbl_db_method_info);
+	if (ACPI_FAILURE(status)) {
+		return;
+	}
+
+	/* Get the NS node, determines existence also */
+
+	status = acpi_get_handle(NULL, acpi_gbl_db_method_info.pathname,
+				 &acpi_gbl_db_method_info.method);
+	if (ACPI_FAILURE(status)) {
+		acpi_os_printf("%s Could not get handle for %s\n",
+			       acpi_format_exception(status),
+			       acpi_gbl_db_method_info.pathname);
+		return;
+	}
+
+	status = acpi_os_execute(OSL_DEBUGGER_EXEC_THREAD,
+				 acpi_db_single_execution_thread,
+				 &acpi_gbl_db_method_info);
+	if (ACPI_FAILURE(status)) {
+		return;
+	}
+
+	acpi_os_printf("\nBackground thread started\n");
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_db_create_execution_threads
+ *
+ * PARAMETERS:  num_threads_arg         - Number of threads to create
+ *              num_loops_arg           - Loop count for the thread(s)
+ *              method_name_arg         - Control method to execute
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Create threads to execute method(s)
+ *
+ ******************************************************************************/
+
+void
+acpi_db_create_execution_threads(char *num_threads_arg,
+				 char *num_loops_arg, char *method_name_arg)
+{
+	acpi_status status;
+	u32 num_threads;
+	u32 num_loops;
+	u32 i;
+	u32 size;
+	acpi_mutex main_thread_gate;
+	acpi_mutex thread_complete_gate;
+	acpi_mutex info_gate;
+
+	/* Get the arguments */
+
+	num_threads = strtoul(num_threads_arg, NULL, 0);
+	num_loops = strtoul(num_loops_arg, NULL, 0);
+
+	if (!num_threads || !num_loops) {
+		acpi_os_printf("Bad argument: Threads %X, Loops %X\n",
+			       num_threads, num_loops);
+		return;
+	}
+
+	/*
+	 * Create the semaphore for synchronization of
+	 * the created threads with the main thread.
+	 */
+	status = acpi_os_create_semaphore(1, 0, &main_thread_gate);
+	if (ACPI_FAILURE(status)) {
+		acpi_os_printf("Could not create semaphore for "
+			       "synchronization with the main thread, %s\n",
+			       acpi_format_exception(status));
+		return;
+	}
+
+	/*
+	 * Create the semaphore for synchronization
+	 * between the created threads.
+	 */
+	status = acpi_os_create_semaphore(1, 1, &thread_complete_gate);
+	if (ACPI_FAILURE(status)) {
+		acpi_os_printf("Could not create semaphore for "
+			       "synchronization between the created threads, %s\n",
+			       acpi_format_exception(status));
+
+		(void)acpi_os_delete_semaphore(main_thread_gate);
+		return;
+	}
+
+	status = acpi_os_create_semaphore(1, 1, &info_gate);
+	if (ACPI_FAILURE(status)) {
+		acpi_os_printf("Could not create semaphore for "
+			       "synchronization of AcpiGbl_DbMethodInfo, %s\n",
+			       acpi_format_exception(status));
+
+		(void)acpi_os_delete_semaphore(thread_complete_gate);
+		(void)acpi_os_delete_semaphore(main_thread_gate);
+		return;
+	}
+
+	memset(&acpi_gbl_db_method_info, 0, sizeof(struct acpi_db_method_info));
+
+	/* Array to store IDs of threads */
+
+	acpi_gbl_db_method_info.num_threads = num_threads;
+	size = sizeof(acpi_thread_id) * acpi_gbl_db_method_info.num_threads;
+
+	acpi_gbl_db_method_info.threads = acpi_os_allocate(size);
+	if (acpi_gbl_db_method_info.threads == NULL) {
+		acpi_os_printf("No memory for thread IDs array\n");
+		(void)acpi_os_delete_semaphore(main_thread_gate);
+		(void)acpi_os_delete_semaphore(thread_complete_gate);
+		(void)acpi_os_delete_semaphore(info_gate);
+		return;
+	}
+	memset(acpi_gbl_db_method_info.threads, 0, size);
+
+	/* Setup the context to be passed to each thread */
+
+	acpi_gbl_db_method_info.name = method_name_arg;
+	acpi_gbl_db_method_info.flags = 0;
+	acpi_gbl_db_method_info.num_loops = num_loops;
+	acpi_gbl_db_method_info.main_thread_gate = main_thread_gate;
+	acpi_gbl_db_method_info.thread_complete_gate = thread_complete_gate;
+	acpi_gbl_db_method_info.info_gate = info_gate;
+
+	/* Init arguments to be passed to method */
+
+	acpi_gbl_db_method_info.init_args = 1;
+	acpi_gbl_db_method_info.args = acpi_gbl_db_method_info.arguments;
+	acpi_gbl_db_method_info.arguments[0] =
+	    acpi_gbl_db_method_info.num_threads_str;
+	acpi_gbl_db_method_info.arguments[1] =
+	    acpi_gbl_db_method_info.id_of_thread_str;
+	acpi_gbl_db_method_info.arguments[2] =
+	    acpi_gbl_db_method_info.index_of_thread_str;
+	acpi_gbl_db_method_info.arguments[3] = NULL;
+
+	acpi_gbl_db_method_info.types = acpi_gbl_db_method_info.arg_types;
+	acpi_gbl_db_method_info.arg_types[0] = ACPI_TYPE_INTEGER;
+	acpi_gbl_db_method_info.arg_types[1] = ACPI_TYPE_INTEGER;
+	acpi_gbl_db_method_info.arg_types[2] = ACPI_TYPE_INTEGER;
+
+	acpi_db_uint32_to_hex_string(num_threads,
+				     acpi_gbl_db_method_info.num_threads_str);
+
+	status = acpi_db_execute_setup(&acpi_gbl_db_method_info);
+	if (ACPI_FAILURE(status)) {
+		goto cleanup_and_exit;
+	}
+
+	/* Get the NS node, determines existence also */
+
+	status = acpi_get_handle(NULL, acpi_gbl_db_method_info.pathname,
+				 &acpi_gbl_db_method_info.method);
+	if (ACPI_FAILURE(status)) {
+		acpi_os_printf("%s Could not get handle for %s\n",
+			       acpi_format_exception(status),
+			       acpi_gbl_db_method_info.pathname);
+		goto cleanup_and_exit;
+	}
+
+	/* Create the threads */
+
+	acpi_os_printf("Creating %X threads to execute %X times each\n",
+		       num_threads, num_loops);
+
+	for (i = 0; i < (num_threads); i++) {
+		status =
+		    acpi_os_execute(OSL_DEBUGGER_EXEC_THREAD,
+				    acpi_db_method_thread,
+				    &acpi_gbl_db_method_info);
+		if (ACPI_FAILURE(status)) {
+			break;
+		}
+	}
+
+	/* Wait for all threads to complete */
+
+	(void)acpi_os_wait_semaphore(main_thread_gate, 1, ACPI_WAIT_FOREVER);
+
+	acpi_db_set_output_destination(ACPI_DB_DUPLICATE_OUTPUT);
+	acpi_os_printf("All threads (%X) have completed\n", num_threads);
+	acpi_db_set_output_destination(ACPI_DB_CONSOLE_OUTPUT);
+
+cleanup_and_exit:
+
+	/* Cleanup and exit */
+
+	(void)acpi_os_delete_semaphore(main_thread_gate);
+	(void)acpi_os_delete_semaphore(thread_complete_gate);
+	(void)acpi_os_delete_semaphore(info_gate);
+
+	acpi_os_free(acpi_gbl_db_method_info.threads);
+	acpi_gbl_db_method_info.threads = NULL;
+}