ACPICA: Fix issues/fault with automatic "serialized" method support

History: This support changes a method to "serialized" on the fly if the
method generates an AE_ALREADY_EXISTS error, indicating the possibility
that it cannot handle reentrancy.

This fix repairs a couple of issues seen in the field, especially on
machines with many cores.

1) Delete method children only upon the exit of the last thread, so
as to not delete objects out from under running threads.

2) Set the "serialized" bit for the method only upon the exit of the
last thread, so as to not cause deadlock when running threads attempt
to exit.

3) Cleanup the use of the AML "MethodFlags" and internal method flags
so that there is no longer any confustion between the two.

Reported-by: Dana Myers <dana.myers@oracle.com>
Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 8 insertions, 17 deletions

diff --git a/drivers/acpi/acpica/psparse.c b/drivers/acpi/acpica/psparse.c
index 8d81542..3b8de11 100644
--- a/drivers/acpi/acpica/psparse.c
+++ b/drivers/acpi/acpica/psparse.c
@@ -55,7 +55,6 @@
 #include "acparser.h"
 #include "acdispat.h"
 #include "amlcode.h"
-#include "acnamesp.h"
 #include "acinterp.h"
 
 #define _COMPONENT          ACPI_PARSER
@@ -539,24 +538,16 @@ acpi_status acpi_ps_parse_aml(struct acpi_walk_state *walk_state)
 			/* Check for possible multi-thread reentrancy problem */
 
 			if ((status == AE_ALREADY_EXISTS) &&
-			    (!walk_state->method_desc->method.mutex)) {
-				ACPI_INFO((AE_INFO,
-					   "Marking method %4.4s as Serialized because of AE_ALREADY_EXISTS error",
-					   walk_state->method_node->name.
-					   ascii));
-
+			    (!(walk_state->method_desc->method.
+			       info_flags & ACPI_METHOD_SERIALIZED))) {
 				/*
-				 * Method tried to create an object twice. The probable cause is
-				 * that the method cannot handle reentrancy.
-				 *
-				 * The method is marked not_serialized, but it tried to create
-				 * a named object, causing the second thread entrance to fail.
-				 * Workaround this problem by marking the method permanently
-				 * as Serialized.
+				 * Method is not serialized and tried to create an object
+				 * twice. The probable cause is that the method cannot
+				 * handle reentrancy. Mark as "pending serialized" now, and
+				 * then mark "serialized" when the last thread exits.
 				 */
-				walk_state->method_desc->method.method_flags |=
-				    AML_METHOD_SERIALIZED;
-				walk_state->method_desc->method.sync_level = 0;
+				walk_state->method_desc->method.info_flags |=
+				    ACPI_METHOD_SERIALIZED_PENDING;
 			}
 		}