ACPICA: fix AML mutex re-entrancy
ACPI AML supports "serialized" methods which are protected
by an implicit mutex. The mutex is re-entrant for that AML thread
to allow recursion.
However, Linux implements notify() by creating a new AML thread.
So for systems where notify() re-enters a serialized method,
deadlock results.
The fix is to use the Linux thread_id as the key to allowing
re-entrancy, not the AML thread pointer.
http://bugzilla.kernel.org/show_bug.cgi?id=5534
Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/acpi/executer/exmutex.c b/drivers/acpi/executer/exmutex.c
index 5101bad..4eb883b 100644
--- a/drivers/acpi/executer/exmutex.c
+++ b/drivers/acpi/executer/exmutex.c
@@ -66,10 +66,9 @@
*
******************************************************************************/
-void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc)
+void acpi_ex_unlink_mutex(union acpi_operand_object *obj_desc,
+ struct acpi_thread_state *thread)
{
- struct acpi_thread_state *thread = obj_desc->mutex.owner_thread;
-
if (!thread) {
return;
}
@@ -174,16 +173,13 @@
/* Support for multiple acquires by the owning thread */
- if (obj_desc->mutex.owner_thread) {
- if (obj_desc->mutex.owner_thread->thread_id ==
- walk_state->thread->thread_id) {
- /*
- * The mutex is already owned by this thread, just increment the
- * acquisition depth
- */
- obj_desc->mutex.acquisition_depth++;
- return_ACPI_STATUS(AE_OK);
- }
+ if (obj_desc->mutex.owner_thread_id == acpi_os_get_thread_id()) {
+ /*
+ * The mutex is already owned by this thread, just increment the
+ * acquisition depth
+ */
+ obj_desc->mutex.acquisition_depth++;
+ return_ACPI_STATUS(AE_OK);
}
/* Acquire the mutex, wait if necessary. Special case for Global Lock */
@@ -206,7 +202,7 @@
/* Have the mutex: update mutex and walk info and save the sync_level */
- obj_desc->mutex.owner_thread = walk_state->thread;
+ obj_desc->mutex.owner_thread_id = acpi_os_get_thread_id();
obj_desc->mutex.acquisition_depth = 1;
obj_desc->mutex.original_sync_level =
walk_state->thread->current_sync_level;
@@ -246,7 +242,7 @@
/* The mutex must have been previously acquired in order to release it */
- if (!obj_desc->mutex.owner_thread) {
+ if (!obj_desc->mutex.owner_thread_id) {
ACPI_ERROR((AE_INFO,
"Cannot release Mutex [%4.4s], not acquired",
acpi_ut_get_node_name(obj_desc->mutex.node)));
@@ -266,14 +262,14 @@
* The Mutex is owned, but this thread must be the owner.
* Special case for Global Lock, any thread can release
*/
- if ((obj_desc->mutex.owner_thread->thread_id !=
+ if ((obj_desc->mutex.owner_thread_id !=
walk_state->thread->thread_id)
&& (obj_desc->mutex.os_mutex != acpi_gbl_global_lock_mutex)) {
ACPI_ERROR((AE_INFO,
"Thread %lX cannot release Mutex [%4.4s] acquired by thread %lX",
(unsigned long)walk_state->thread->thread_id,
acpi_ut_get_node_name(obj_desc->mutex.node),
- (unsigned long)obj_desc->mutex.owner_thread->thread_id));
+ (unsigned long)obj_desc->mutex.owner_thread_id));
return_ACPI_STATUS(AE_AML_NOT_OWNER);
}
@@ -300,7 +296,7 @@
/* Unlink the mutex from the owner's list */
- acpi_ex_unlink_mutex(obj_desc);
+ acpi_ex_unlink_mutex(obj_desc, walk_state->thread);
/* Release the mutex, special case for Global Lock */
@@ -312,7 +308,7 @@
/* Update the mutex and restore sync_level */
- obj_desc->mutex.owner_thread = NULL;
+ obj_desc->mutex.owner_thread_id = ACPI_MUTEX_NOT_ACQUIRED;
walk_state->thread->current_sync_level =
obj_desc->mutex.original_sync_level;
@@ -367,7 +363,7 @@
/* Mark mutex unowned */
- obj_desc->mutex.owner_thread = NULL;
+ obj_desc->mutex.owner_thread_id = ACPI_MUTEX_NOT_ACQUIRED;
/* Update Thread sync_level (Last mutex is the important one) */