locking, hpet: annotate false positive warning
Peter Zijlstra [Mon, 12 Jan 2009 11:52:23 +0000 (12:52 +0100)]
Alexander Beregalov reported that this warning is caused by the HPET code:

> hpet0: at MMIO 0xfed00000, IRQs 2, 8, 0
> hpet0: 3 comparators, 64-bit 14.318180 MHz counter
> ODEBUG: object is on stack, but not annotated
> ------------[ cut here ]------------
> WARNING: at lib/debugobjects.c:251 __debug_object_init+0x2a4/0x352()

> Bisected down to 26afe5f2fbf06ea0765aaa316640c4dd472310c0
> (x86: HPET_MSI Initialise per-cpu HPET timers)

The commit is fine - but the on-stack workqueue entry needs annotation.

Reported-and-bisected-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/x86/kernel/hpet.c
include/linux/workqueue.h

index cd759ad..bb2e0f0 100644 (file)
@@ -628,7 +628,7 @@ static int hpet_cpuhp_notify(struct notifier_block *n,
 
        switch (action & 0xf) {
        case CPU_ONLINE:
-               INIT_DELAYED_WORK(&work.work, hpet_work);
+               INIT_DELAYED_WORK_ON_STACK(&work.work, hpet_work);
                init_completion(&work.complete);
                /* FIXME: add schedule_work_on() */
                schedule_delayed_work_on(cpu, &work.work, 0);
index b362911..47151c8 100644 (file)
@@ -118,6 +118,12 @@ struct execute_work {
                init_timer(&(_work)->timer);                    \
        } while (0)
 
+#define INIT_DELAYED_WORK_ON_STACK(_work, _func)               \
+       do {                                                    \
+               INIT_WORK(&(_work)->work, (_func));             \
+               init_timer_on_stack(&(_work)->timer);           \
+       } while (0)
+
 #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func)                     \
        do {                                                    \
                INIT_WORK(&(_work)->work, (_func));             \