From b778ae25366e6f3891fe51306f56a3bca211975d Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Tue, 23 Apr 2013 12:51:11 -0700 Subject: [PATCH] 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: Paul E. McKenney Cc: Mathieu Desnoyers Cc: Sedat Dilek Cc: Davidlohr Bueso Cc: Rik van Riel Cc: Thomas Gleixner Cc: Linus Torvalds Tested-by: Sedat Dilek Reviewed-by: Josh Triplett --- include/linux/debugobjects.h | 6 +++--- lib/debugobjects.c | 20 ++++++++++++++------ 2 files changed, 17 insertions(+), 9 deletions(-) diff --git a/include/linux/debugobjects.h b/include/linux/debugobjects.h index 0e5f5785d9f2..98ffcbd4888e 100644 --- a/include/linux/debugobjects.h +++ b/include/linux/debugobjects.h @@ -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 diff --git a/lib/debugobjects.c b/lib/debugobjects.c index 37061ede8b81..bf2c8b1043d8 100644 --- a/lib/debugobjects.c +++ b/lib/debugobjects.c @@ -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; } /** -- 2.20.1