Implement a basic state machine checker in the debugobjects. Signed-off-by: Mathieu Desnoyers CC: "Paul E. McKenney" CC: akpm@linux-foundation.org CC: mingo@elte.hu CC: laijs@cn.fujitsu.com CC: dipankar@in.ibm.com CC: josh@joshtriplett.org CC: dvhltc@us.ibm.com CC: niv@us.ibm.com CC: tglx@linutronix.de CC: peterz@infradead.org CC: rostedt@goodmis.org CC: Valdis.Kletnieks@vt.edu CC: dhowells@redhat.com CC: eric.dumazet@gmail.com CC: Alexey Dobriyan --- include/linux/debugobjects.h | 9 ++++++ lib/debugobjects.c | 59 ++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 65 insertions(+), 3 deletions(-) Index: linux-2.6-lttng/include/linux/debugobjects.h =================================================================== --- linux-2.6-lttng.orig/include/linux/debugobjects.h 2010-03-19 15:26:02.000000000 -0400 +++ linux-2.6-lttng/include/linux/debugobjects.h 2010-03-19 15:26:06.000000000 -0400 @@ -20,12 +20,14 @@ struct debug_obj_descr; * struct debug_obj - representaion of an tracked object * @node: hlist node to link the object into the tracker list * @state: tracked object state + * @astate: current active state * @object: pointer to the real object * @descr: pointer to an object type specific debug description structure */ struct debug_obj { struct hlist_node node; enum debug_obj_state state; + unsigned int astate; void *object; struct debug_obj_descr *descr; }; @@ -60,6 +62,13 @@ extern void debug_object_deactivate(void extern void debug_object_destroy (void *addr, struct debug_obj_descr *descr); extern void debug_object_free (void *addr, struct debug_obj_descr *descr); +/* + * Active state must return to 0 before deactivation. + */ +extern void +debug_object_active_state(void *addr, struct debug_obj_descr *descr, + unsigned int expect, unsigned int next); + extern void debug_objects_early_init(void); extern void debug_objects_mem_init(void); #else Index: linux-2.6-lttng/lib/debugobjects.c =================================================================== --- linux-2.6-lttng.orig/lib/debugobjects.c 2010-03-19 15:26:02.000000000 -0400 +++ linux-2.6-lttng/lib/debugobjects.c 2010-03-19 15:26:06.000000000 -0400 @@ -140,6 +140,7 @@ alloc_object(void *addr, struct debug_bu obj->object = addr; obj->descr = descr; obj->state = ODEBUG_STATE_NONE; + obj->astate = 0; hlist_del(&obj->node); hlist_add_head(&obj->node, &b->list); @@ -251,8 +252,10 @@ static void debug_print_object(struct de if (limit < 5 && obj->descr != descr_test) { limit++; - WARN(1, KERN_ERR "ODEBUG: %s %s object type: %s\n", msg, - obj_states[obj->state], obj->descr->name); + WARN(1, KERN_ERR "ODEBUG: %s %s (active state %u) " + "object type: %s\n", + msg, obj_states[obj->state], obj->astate, + obj->descr->name); } debug_objects_warnings++; } @@ -446,7 +449,10 @@ void debug_object_deactivate(void *addr, case ODEBUG_STATE_INIT: case ODEBUG_STATE_INACTIVE: case ODEBUG_STATE_ACTIVE: - obj->state = ODEBUG_STATE_INACTIVE; + if (!obj->astate) + obj->state = ODEBUG_STATE_INACTIVE; + else + debug_print_object(obj, "deactivate"); break; case ODEBUG_STATE_DESTROYED: @@ -552,6 +558,53 @@ out_unlock: raw_spin_unlock_irqrestore(&db->lock, flags); } +/** + * debug_object_active_state - debug checks object usage state machine + * @addr: address of the object + * @descr: pointer to an object specific debug description structure + * @expect: expected state + * @next: state to move to if expected state is found + */ +void +debug_object_active_state(void *addr, struct debug_obj_descr *descr, + unsigned int expect, unsigned int next) +{ + struct debug_bucket *db; + struct debug_obj *obj; + unsigned long flags; + + if (!debug_objects_enabled) + return; + + db = get_bucket((unsigned long) addr); + + raw_spin_lock_irqsave(&db->lock, flags); + + obj = lookup_object(addr, db); + if (obj) { + switch (obj->state) { + case ODEBUG_STATE_ACTIVE: + if (obj->astate == expect) + obj->astate = next; + else + debug_print_object(obj, "active_state"); + break; + + default: + debug_print_object(obj, "active_state"); + break; + } + } else { + struct debug_obj o = { .object = addr, + .state = ODEBUG_STATE_NOTAVAILABLE, + .descr = descr }; + + debug_print_object(&o, "active_state"); + } + + raw_spin_unlock_irqrestore(&db->lock, flags); +} + #ifdef CONFIG_DEBUG_OBJECTS_FREE static void __debug_check_no_obj_freed(const void *address, unsigned long size) { -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/