Commit c0d127b5 authored by Alexey Starikovskiy's avatar Alexey Starikovskiy Committed by Len Brown
Browse files

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: default avatarAlexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
parent 724339d7

drivers/acpi/dispatcher/dsmethod.c

+5 −7
Original line number Diff line number Diff line
@@ -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;

		}

	}

drivers/acpi/executer/exdump.c

+1 −1
Original line number Diff line number Diff line
@@ -134,7 +134,7 @@ static struct acpi_exdump_info acpi_ex_dump_method[8] = { 
static struct acpi_exdump_info acpi_ex_dump_mutex[5] = {

	{ACPI_EXD_INIT, ACPI_EXD_TABLE_SIZE(acpi_ex_dump_mutex), NULL},

	{ACPI_EXD_UINT8, ACPI_EXD_OFFSET(mutex.sync_level), "Sync Level"},

	{ACPI_EXD_POINTER, ACPI_EXD_OFFSET(mutex.owner_thread), "Owner Thread"},

	{ACPI_EXD_POINTER, ACPI_EXD_OFFSET(mutex.owner_thread_id), "Owner Thread"},

	{ACPI_EXD_UINT16, ACPI_EXD_OFFSET(mutex.acquisition_depth),

	 "Acquire Depth"},

	{ACPI_EXD_POINTER, ACPI_EXD_OFFSET(mutex.os_mutex), "OsMutex"}

drivers/acpi/executer/exmutex.c

+16 −20
Original line number Diff line number Diff line
@@ -66,10 +66,9 @@ acpi_ex_link_mutex(union acpi_operand_object *obj_desc, 
 *

 ******************************************************************************/



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;

	}
@@ -174,9 +173,7 @@ acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, 


	/* 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) {

	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
@@ -184,7 +181,6 @@ acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, 
		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 @@ acpi_ex_acquire_mutex(union acpi_operand_object *time_desc, 


	/* 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 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, 


	/* 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 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, 
	 * 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 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, 


	/* 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 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, 


	/* 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 @@ void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread) 


		/* 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) */

drivers/acpi/utilities/utdelete.c

+0 −1
Original line number Diff line number Diff line
@@ -170,7 +170,6 @@ static void acpi_ut_delete_internal_obj(union acpi_operand_object *object) 
			acpi_os_delete_mutex(object->mutex.os_mutex);

			acpi_gbl_global_lock_mutex = NULL;

		} else {

			acpi_ex_unlink_mutex(object);

			acpi_os_delete_mutex(object->mutex.os_mutex);

		}

		break;

include/acpi/acinterp.h

+2 −1
Original line number Diff line number Diff line
@@ -253,7 +253,8 @@ acpi_ex_release_mutex(union acpi_operand_object *obj_desc, 


void acpi_ex_release_all_mutexes(struct acpi_thread_state *thread);



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);



/*

 * exprep - ACPI AML execution - prep utilities

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