ACPICA: Fix for Alias operator to see target child objects

Fixed a problem with the Alias operator when the target of the
alias is a named ASL operator that opens a new scope -- Scope,
Device, PowerResource, Processor, and ThermalZone. In these cases,
any children of the original operator could not be accessed via
the alias, potentially causing unexpected AE_NOT_FOUND exceptions.

Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Alexey Starikovskiy <astarikovskiy@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/executer/excreate.c b/drivers/acpi/executer/excreate.c
index 6e9a23e..b391439 100644 (file)
--- a/drivers/acpi/executer/excreate.c
+++ b/drivers/acpi/executer/excreate.c
@@ -96,6 +96,9 @@ acpi_status acpi_ex_create_alias(struct acpi_walk_state *walk_state)
         * to the original Node.
         */
        switch (target_node->type) {
+
+               /* For these types, the sub-object can change dynamically via a Store */
+
        case ACPI_TYPE_INTEGER:
        case ACPI_TYPE_STRING:
        case ACPI_TYPE_BUFFER:
@@ -103,9 +106,18 @@ acpi_status acpi_ex_create_alias(struct acpi_walk_state *walk_state)
        case ACPI_TYPE_BUFFER_FIELD:
 
                /*
+                * These types open a new scope, so we need the NS node in order to access
+                * any children.
+                */
+       case ACPI_TYPE_DEVICE:
+       case ACPI_TYPE_POWER:
+       case ACPI_TYPE_PROCESSOR:
+       case ACPI_TYPE_THERMAL:
+       case ACPI_TYPE_LOCAL_SCOPE:
+
+               /*
                 * The new alias has the type ALIAS and points to the original
-                * NS node, not the object itself.  This is because for these
-                * types, the object can change dynamically via a Store.
+                * NS node, not the object itself.
                 */
                alias_node->type = ACPI_TYPE_LOCAL_ALIAS;
                alias_node->object =
@@ -115,9 +127,7 @@ acpi_status acpi_ex_create_alias(struct acpi_walk_state *walk_state)
        case ACPI_TYPE_METHOD:
 
                /*
-                * The new alias has the type ALIAS and points to the original
-                * NS node, not the object itself.  This is because for these
-                * types, the object can change dynamically via a Store.
+                * Control method aliases need to be differentiated
                 */
                alias_node->type = ACPI_TYPE_LOCAL_METHOD_ALIAS;
                alias_node->object =

diff --git a/drivers/acpi/namespace/nsaccess.c b/drivers/acpi/namespace/nsaccess.c
index 32a0167..54852fb 100644 (file)
--- a/drivers/acpi/namespace/nsaccess.c
+++ b/drivers/acpi/namespace/nsaccess.c
@@ -581,44 +581,68 @@ acpi_ns_lookup(union acpi_generic_state *scope_info,
                        return_ACPI_STATUS(status);
                }
 
-               /*
-                * Sanity typecheck of the target object:
-                *
-                * If 1) This is the last segment (num_segments == 0)
-                *    2) And we are looking for a specific type
-                *       (Not checking for TYPE_ANY)
-                *    3) Which is not an alias
-                *    4) Which is not a local type (TYPE_SCOPE)
-                *    5) And the type of target object is known (not TYPE_ANY)
-                *    6) And target object does not match what we are looking for
-                *
-                * Then we have a type mismatch.  Just warn and ignore it.
-                */
-               if ((num_segments == 0) &&
-                   (type_to_check_for != ACPI_TYPE_ANY) &&
-                   (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
-                   (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS) &&
-                   (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE) &&
-                   (this_node->type != ACPI_TYPE_ANY) &&
-                   (this_node->type != type_to_check_for)) {
-
-                       /* Complain about a type mismatch */
-
-                       ACPI_WARNING((AE_INFO,
-                                     "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
-                                     ACPI_CAST_PTR(char, &simple_name),
-                                     acpi_ut_get_type_name(this_node->type),
-                                     acpi_ut_get_type_name
-                                     (type_to_check_for)));
+               /* More segments to follow? */
+
+               if (num_segments > 0) {
+                       /*
+                        * If we have an alias to an object that opens a scope (such as a
+                        * device or processor), we need to dereference the alias here so that
+                        * we can access any children of the original node (via the remaining
+                        * segments).
+                        */
+                       if (this_node->type == ACPI_TYPE_LOCAL_ALIAS) {
+                               if (acpi_ns_opens_scope
+                                   (((struct acpi_namespace_node *)this_node->
+                                     object)->type)) {
+                                       this_node =
+                                           (struct acpi_namespace_node *)
+                                           this_node->object;
+                               }
+                       }
                }
 
-               /*
-                * If this is the last name segment and we are not looking for a
-                * specific type, but the type of found object is known, use that type
-                * to see if it opens a scope.
-                */
-               if ((num_segments == 0) && (type == ACPI_TYPE_ANY)) {
-                       type = this_node->type;
+               /* Special handling for the last segment (num_segments == 0) */
+
+               else {
+                       /*
+                        * Sanity typecheck of the target object:
+                        *
+                        * If 1) This is the last segment (num_segments == 0)
+                        *    2) And we are looking for a specific type
+                        *       (Not checking for TYPE_ANY)
+                        *    3) Which is not an alias
+                        *    4) Which is not a local type (TYPE_SCOPE)
+                        *    5) And the type of target object is known (not TYPE_ANY)
+                        *    6) And target object does not match what we are looking for
+                        *
+                        * Then we have a type mismatch. Just warn and ignore it.
+                        */
+                       if ((type_to_check_for != ACPI_TYPE_ANY) &&
+                           (type_to_check_for != ACPI_TYPE_LOCAL_ALIAS) &&
+                           (type_to_check_for != ACPI_TYPE_LOCAL_METHOD_ALIAS)
+                           && (type_to_check_for != ACPI_TYPE_LOCAL_SCOPE)
+                           && (this_node->type != ACPI_TYPE_ANY)
+                           && (this_node->type != type_to_check_for)) {
+
+                               /* Complain about a type mismatch */
+
+                               ACPI_WARNING((AE_INFO,
+                                             "NsLookup: Type mismatch on %4.4s (%s), searching for (%s)",
+                                             ACPI_CAST_PTR(char, &simple_name),
+                                             acpi_ut_get_type_name(this_node->
+                                                                   type),
+                                             acpi_ut_get_type_name
+                                             (type_to_check_for)));
+                       }
+
+                       /*
+                        * If this is the last name segment and we are not looking for a
+                        * specific type, but the type of found object is known, use that type
+                        * to (later) see if it opens a scope.
+                        */
+                       if (type == ACPI_TYPE_ANY) {
+                               type = this_node->type;
+                       }
                }
 
                /* Point to next name segment and make this node current */