Commit b778ae25 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

debugobjects: Make debug_object_activate() return status 



In order to better respond to things like duplicate invocations
of call_rcu(), RCU needs to see the status of a call to
debug_object_activate().  This would allow RCU to leak the callback in
order to avoid adding freelist-reuse mischief to the duplicate invoations.
This commit therefore makes debug_object_activate() return status,
zero for success and -EINVAL for failure.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Davidlohr Bueso <davidlohr.bueso@hp.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: default avatarSedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: default avatarJosh Triplett <josh@joshtriplett.org>
parent 15100df8

include/linux/debugobjects.h

+3 −3
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ struct debug_obj_descr { 
extern void debug_object_init      (void *addr, struct debug_obj_descr *descr);

extern void

debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr);

extern void debug_object_activate  (void *addr, struct debug_obj_descr *descr);

extern int debug_object_activate  (void *addr, struct debug_obj_descr *descr);

extern void debug_object_deactivate(void *addr, struct debug_obj_descr *descr);

extern void debug_object_destroy   (void *addr, struct debug_obj_descr *descr);

extern void debug_object_free      (void *addr, struct debug_obj_descr *descr);
@@ -85,8 +85,8 @@ static inline void 
debug_object_init      (void *addr, struct debug_obj_descr *descr) { }

static inline void

debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) { }

static inline void

debug_object_activate  (void *addr, struct debug_obj_descr *descr) { }

static inline int

debug_object_activate  (void *addr, struct debug_obj_descr *descr) { return 0; }

static inline void

debug_object_deactivate(void *addr, struct debug_obj_descr *descr) { }

static inline void

lib/debugobjects.c

+14 −6
Original line number Diff line number Diff line
@@ -381,19 +381,21 @@ void debug_object_init_on_stack(void *addr, struct debug_obj_descr *descr) 
 * debug_object_activate - debug checks when an object is activated

 * @addr:	address of the object

 * @descr:	pointer to an object specific debug description structure

 * Returns 0 for success, -EINVAL for check failed.

 */

void debug_object_activate(void *addr, struct debug_obj_descr *descr)

int debug_object_activate(void *addr, struct debug_obj_descr *descr)

{

	enum debug_obj_state state;

	struct debug_bucket *db;

	struct debug_obj *obj;

	unsigned long flags;

	int ret;

	struct debug_obj o = { .object = addr,

			       .state = ODEBUG_STATE_NOTAVAILABLE,

			       .descr = descr };



	if (!debug_objects_enabled)

		return;

		return 0;



	db = get_bucket((unsigned long) addr);
@@ -405,23 +407,26 @@ void debug_object_activate(void *addr, struct debug_obj_descr *descr) 
		case ODEBUG_STATE_INIT:

		case ODEBUG_STATE_INACTIVE:

			obj->state = ODEBUG_STATE_ACTIVE;

			ret = 0;

			break;



		case ODEBUG_STATE_ACTIVE:

			debug_print_object(obj, "activate");

			state = obj->state;

			raw_spin_unlock_irqrestore(&db->lock, flags);

			debug_object_fixup(descr->fixup_activate, addr, state);

			return;

			ret = debug_object_fixup(descr->fixup_activate, addr, state);

			return ret ? -EINVAL : 0;



		case ODEBUG_STATE_DESTROYED:

			debug_print_object(obj, "activate");

			ret = -EINVAL;

			break;

		default:

			ret = 0;

			break;

		}

		raw_spin_unlock_irqrestore(&db->lock, flags);

		return;

		return ret;

	}



	raw_spin_unlock_irqrestore(&db->lock, flags);
@@ -431,8 +436,11 @@ void debug_object_activate(void *addr, struct debug_obj_descr *descr) 
	 * true or not.

	 */

	if (debug_object_fixup(descr->fixup_activate, addr,

			   ODEBUG_STATE_NOTAVAILABLE))

			   ODEBUG_STATE_NOTAVAILABLE)) {

		debug_print_object(&o, "activate");

		return -EINVAL;

	}

	return 0;

}



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