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: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/dispatcher/dswload.c b/drivers/acpi/dispatcher/dswload.c
index 565d4557d0e0575957b63c80a5fbb6bca7640c12..4ed08680ae7c2a44f401ef2174095bd0f00db050 100644 (file)
--- a/drivers/acpi/dispatcher/dswload.c
+++ b/drivers/acpi/dispatcher/dswload.c
@@ -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 */

diff --git a/drivers/acpi/namespace/nsdump.c b/drivers/acpi/namespace/nsdump.c
index da88834f55e78d7470ad2838bdb6646e21386676..ec5ce59acb9892eceb771059f2cf99fdccba4692 100644 (file)
--- a/drivers/acpi/namespace/nsdump.c
+++ b/drivers/acpi/namespace/nsdump.c
@@ -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);
 }

diff --git a/drivers/acpi/namespace/nssearch.c b/drivers/acpi/namespace/nssearch.c
index 566f0a4aff930340494797b4015e1aa4b2bec445..d261c9bcd4508c7485d0e7757ffda48944d25db6 100644 (file)
--- a/drivers/acpi/namespace/nssearch.c
+++ b/drivers/acpi/namespace/nssearch.c
@@ -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);

diff --git a/drivers/acpi/namespace/nswalk.c b/drivers/acpi/namespace/nswalk.c
index c8f6bef16ed05a1fcc3e1128162624a69041107e..a138fcb832a33160b7fd76aa6b63ba2749905462 100644 (file)
--- a/drivers/acpi/namespace/nswalk.c
+++ b/drivers/acpi/namespace/nswalk.c
@@ -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);

diff --git a/include/acpi/aclocal.h b/include/acpi/aclocal.h
index 553763d7312a8e5ea397b461500f63d30fcfbaa7..287da6fe256ca6a78d88badab8a55e89c9ccfd9d 100644 (file)
--- a/include/acpi/aclocal.h
+++ b/include/acpi/aclocal.h
@@ -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 */

diff --git a/include/acpi/acnamesp.h b/include/acpi/acnamesp.h
index b3b9f0ec79c3c18623669a520181b39ad36c4a75..19a61292af603cb6104574d4c049c2570c00628d 100644 (file)
--- a/include/acpi/acnamesp.h
+++ b/include/acpi/acnamesp.h
@@ -65,9 +65,13 @@
 #define ACPI_NS_ERROR_IF_FOUND      0x08
 #define ACPI_NS_PREFIX_IS_SCOPE     0x10
 #define ACPI_NS_EXTERNAL            0x20
+#define ACPI_NS_TEMPORARY           0x40
 
-#define ACPI_NS_WALK_UNLOCK         TRUE
-#define ACPI_NS_WALK_NO_UNLOCK      FALSE
+/* Flags for acpi_ns_walk_namespace */
+
+#define ACPI_NS_WALK_NO_UNLOCK      0
+#define ACPI_NS_WALK_UNLOCK         0x01
+#define ACPI_NS_WALK_TEMP_NODES     0x02
 
 /*
  * nsinit - Namespace initialization
@@ -92,7 +96,7 @@ acpi_status
 acpi_ns_walk_namespace(acpi_object_type type,
                       acpi_handle start_object,
                       u32 max_depth,
-                      u8 unlock_before_callback,
+                      u32 flags,
                       acpi_walk_callback user_function,
                       void *context, void **return_value);