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authorAlexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>2007-02-15 16:12:23 -0500
committerLen Brown <len.brown@intel.com>2007-02-15 16:13:16 -0500
commitc0d127b56937c3e72c2b1819161d2f6718eee877 (patch)
tree40ac0fd3a628685ce25d11d1b00360344279ec5b /drivers/acpi/dispatcher
parent724339d76d9407cd1a8ad32a9c1fdf64840cc51b (diff)
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>
Diffstat (limited to 'drivers/acpi/dispatcher')
-rw-r--r--drivers/acpi/dispatcher/dsmethod.c12
1 files changed, 5 insertions, 7 deletions
diff --git a/drivers/acpi/dispatcher/dsmethod.c b/drivers/acpi/dispatcher/dsmethod.c
index 1cbe6190582..1683e5c5b94 100644
--- a/drivers/acpi/dispatcher/dsmethod.c
+++ b/drivers/acpi/dispatcher/dsmethod.c
@@ -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;
}
}