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ACPICA: fix AML mutex re-entrancy

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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>
This commit is contained in:
Alexey Starikovskiy
2007-02-15 16:12:23 -05:00
committed by Len Brown
parent 724339d76d
commit c0d127b569
6 changed files with 25 additions and 31 deletions
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12
drivers/acpi/dispatcher/dsmethod.c
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@@ -231,10 +231,8 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
* Obtain the method mutex if necessary. Do not acquire mutex for a
* recursive call.
*/
if (!walk_state ||
!obj_desc->method.mutex->mutex.owner_thread ||
(walk_state->thread !=
obj_desc->method.mutex->mutex.owner_thread)) {
if (acpi_os_get_thread_id() !=
obj_desc->method.mutex->mutex.owner_thread_id) {
/*
* Acquire the method mutex. This releases the interpreter if we
* block (and reacquires it before it returns)
@@ -248,14 +246,14 @@ acpi_ds_begin_method_execution(struct acpi_namespace_node *method_node,
}
/* Update the mutex and walk info and save the original sync_level */
obj_desc->method.mutex->mutex.owner_thread_id =
acpi_os_get_thread_id();
if (walk_state) {
obj_desc->method.mutex->mutex.
original_sync_level =
walk_state->thread->current_sync_level;
obj_desc->method.mutex->mutex.owner_thread =
walk_state->thread;
walk_state->thread->current_sync_level =
obj_desc->method.sync_level;
} else {
@@ -569,7 +567,7 @@ acpi_ds_terminate_control_method(union acpi_operand_object *method_desc,
acpi_os_release_mutex(method_desc->method.mutex->mutex.
os_mutex);
method_desc->method.mutex->mutex.owner_thread = NULL;
method_desc->method.mutex->mutex.owner_thread_id = ACPI_MUTEX_NOT_ACQUIRED;
}
}