Commit d1fdda83 authored by Bob Moore's avatar Bob Moore Committed by Len Brown
Browse files

ACPICA: Fix race condition with AcpiWalkNamespace. 



Fixed a problem with a possible race condition between threads executing
AcpiWalkNamespace and the AML interpreter. This condition was removed by
modifying AcpiWalkNamespace to (by default) ignore all temporary
namespace entries created during any concurrent control method execution

Signed-off-by: default avatarAlexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 9bc75cff

drivers/acpi/dispatcher/dswload.c

+2 −2
Original line number Diff line number Diff line
@@ -756,9 +756,9 @@ acpi_ds_load2_begin_op(struct acpi_walk_state *walk_state, 
		flags = ACPI_NS_NO_UPSEARCH;

		if (walk_state->pass_number == 3) {



			/* Execution mode, node cannot already exist */

			/* Execution mode, node cannot already exist, node is temporary */



			flags |= ACPI_NS_ERROR_IF_FOUND;

			flags |= (ACPI_NS_ERROR_IF_FOUND | ACPI_NS_TEMPORARY);

		}



		/* Add new entry or lookup existing entry */

drivers/acpi/namespace/nsdump.c

+8 −1
Original line number Diff line number Diff line
@@ -226,6 +226,12 @@ acpi_ns_dump_one_object(acpi_handle obj_handle, 
	obj_desc = acpi_ns_get_attached_object(this_node);

	acpi_dbg_level = dbg_level;



	/* Temp nodes are those nodes created by a control method */



	if (this_node->flags & ANOBJ_TEMPORARY) {

		acpi_os_printf("(T) ");

	}



	switch (info->display_type & ACPI_DISPLAY_MASK) {

	case ACPI_DISPLAY_SUMMARY:
@@ -623,7 +629,8 @@ acpi_ns_dump_objects(acpi_object_type type, 
	info.display_type = display_type;



	(void)acpi_ns_walk_namespace(type, start_handle, max_depth,

				     ACPI_NS_WALK_NO_UNLOCK,

				     ACPI_NS_WALK_NO_UNLOCK |

				     ACPI_NS_WALK_TEMP_NODES,

				     acpi_ns_dump_one_object, (void *)&info,

				     NULL);

}

drivers/acpi/namespace/nssearch.c

+4 −0
Original line number Diff line number Diff line
@@ -402,6 +402,10 @@ acpi_ns_search_and_enter(u32 target_name, 
	}

#endif



	if (flags & ACPI_NS_TEMPORARY) {

		new_node->flags |= ANOBJ_TEMPORARY;

	}



	/* Install the new object into the parent's list of children */



	acpi_ns_install_node(walk_state, node, new_node, type);

drivers/acpi/namespace/nswalk.c

+8 −5
Original line number Diff line number Diff line
@@ -126,7 +126,7 @@ struct acpi_namespace_node *acpi_ns_get_next_node(acpi_object_type type, 
 * PARAMETERS:  Type                - acpi_object_type to search for

 *              start_node          - Handle in namespace where search begins

 *              max_depth           - Depth to which search is to reach

 *              unlock_before_callback- Whether to unlock the NS before invoking

 *              Flags               - Whether to unlock the NS before invoking

 *                                    the callback routine

 *              user_function       - Called when an object of "Type" is found

 *              Context             - Passed to user function
@@ -153,7 +153,7 @@ acpi_status 
acpi_ns_walk_namespace(acpi_object_type type,

		       acpi_handle start_node,

		       u32 max_depth,

		       u8 unlock_before_callback,

		       u32 flags,

		       acpi_walk_callback user_function,

		       void *context, void **return_value)

{
@@ -201,12 +201,15 @@ acpi_ns_walk_namespace(acpi_object_type type, 
				child_type = child_node->type;

			}



			if (child_type == type) {

			if ((child_type == type) &&

			    (!(child_node->flags & ANOBJ_TEMPORARY) ||

			     (child_node->flags & ANOBJ_TEMPORARY)

			     && (flags & ACPI_NS_WALK_TEMP_NODES))) {

				/*

				 * Found a matching node, invoke the user

				 * callback function

				 */

				if (unlock_before_callback) {

				if (flags & ACPI_NS_WALK_UNLOCK) {

					mutex_status =

					    acpi_ut_release_mutex

					    (ACPI_MTX_NAMESPACE);
@@ -219,7 +222,7 @@ acpi_ns_walk_namespace(acpi_object_type type, 
				status = user_function(child_node, level,

						       context, return_value);



				if (unlock_before_callback) {

				if (flags & ACPI_NS_WALK_UNLOCK) {

					mutex_status =

					    acpi_ut_acquire_mutex

					    (ACPI_MTX_NAMESPACE);

include/acpi/aclocal.h

+1 −1
Original line number Diff line number Diff line
@@ -204,7 +204,7 @@ struct acpi_namespace_node { 
/* Namespace Node flags */



#define ANOBJ_END_OF_PEER_LIST          0x01	/* End-of-list, Peer field points to parent */

#define ANOBJ_RESERVED                  0x02	/* Available for future use */

#define ANOBJ_TEMPORARY                 0x02	/* Node is create by a method and is temporary */

#define ANOBJ_METHOD_ARG                0x04	/* Node is a method argument */

#define ANOBJ_METHOD_LOCAL              0x08	/* Node is a method local */

#define ANOBJ_SUBTREE_HAS_INI           0x10	/* Used to optimize device initialization */

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