From: "Paul E. McKenney" <paul...@linux.vnet.ibm.com>
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 <paul...@linux.vnet.ibm.com>
Cc: Mathieu Desnoyers <mathieu.desnoy...@efficios.com>
Cc: Sedat Dilek <sedat.di...@gmail.com>
Cc: Davidlohr Bueso <davidlohr.bu...@hp.com>
Cc: Rik van Riel <r...@surriel.com>
Cc: Thomas Gleixner <t...@linutronix.de>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Tested-by: Sedat Dilek <sedat.di...@gmail.com>
---
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 0e5f578..98ffcbd 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 37061ed..bf2c8b1 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;
}
/**
--
1.8.1.5
--
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