From d8e794dfd51c368ed3f686b7f4172830b60ae47b Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 3 Aug 2012 10:30:45 -0700 Subject: [PATCH] workqueue: set delayed_work->timer function on initialization delayed_work->timer.function is currently initialized during queue_delayed_work_on(). Export delayed_work_timer_fn() and set delayed_work timer function during delayed_work initialization together with other fields. This ensures the timer function is always valid on an initialized delayed_work. This is to help mod_delayed_work() implementation. To detect delayed_work users which diddle with the internal timer, trigger WARN if timer function doesn't match on queue. Signed-off-by: Tejun Heo --- include/linux/workqueue.h | 13 +++++++++++-- kernel/workqueue.c | 7 ++++--- 2 files changed, 15 insertions(+), 5 deletions(-) diff --git a/include/linux/workqueue.h b/include/linux/workqueue.h index 278dc5ddb73..ab95fef38d5 100644 --- a/include/linux/workqueue.h +++ b/include/linux/workqueue.h @@ -16,6 +16,7 @@ struct workqueue_struct; struct work_struct; typedef void (*work_func_t)(struct work_struct *work); +void delayed_work_timer_fn(unsigned long __data); /* * The first word is the work queue pointer and the flags rolled into @@ -124,12 +125,14 @@ struct execute_work { #define __DELAYED_WORK_INITIALIZER(n, f) { \ .work = __WORK_INITIALIZER((n).work, (f)), \ - .timer = TIMER_INITIALIZER(NULL, 0, 0), \ + .timer = TIMER_INITIALIZER(delayed_work_timer_fn, \ + 0, (unsigned long)&(n)), \ } #define __DEFERRED_WORK_INITIALIZER(n, f) { \ .work = __WORK_INITIALIZER((n).work, (f)), \ - .timer = TIMER_DEFERRED_INITIALIZER(NULL, 0, 0), \ + .timer = TIMER_DEFERRED_INITIALIZER(delayed_work_timer_fn, \ + 0, (unsigned long)&(n)), \ } #define DECLARE_WORK(n, f) \ @@ -207,18 +210,24 @@ static inline unsigned int work_static(struct work_struct *work) { return 0; } do { \ INIT_WORK(&(_work)->work, (_func)); \ init_timer(&(_work)->timer); \ + (_work)->timer.function = delayed_work_timer_fn;\ + (_work)->timer.data = (unsigned long)(_work); \ } while (0) #define INIT_DELAYED_WORK_ONSTACK(_work, _func) \ do { \ INIT_WORK_ONSTACK(&(_work)->work, (_func)); \ init_timer_on_stack(&(_work)->timer); \ + (_work)->timer.function = delayed_work_timer_fn;\ + (_work)->timer.data = (unsigned long)(_work); \ } while (0) #define INIT_DELAYED_WORK_DEFERRABLE(_work, _func) \ do { \ INIT_WORK(&(_work)->work, (_func)); \ init_timer_deferrable(&(_work)->timer); \ + (_work)->timer.function = delayed_work_timer_fn;\ + (_work)->timer.data = (unsigned long)(_work); \ } while (0) /** diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 30474c4e107..55392385fe3 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -1112,7 +1112,7 @@ bool queue_work(struct workqueue_struct *wq, struct work_struct *work) } EXPORT_SYMBOL_GPL(queue_work); -static void delayed_work_timer_fn(unsigned long __data) +void delayed_work_timer_fn(unsigned long __data) { struct delayed_work *dwork = (struct delayed_work *)__data; struct cpu_workqueue_struct *cwq = get_work_cwq(&dwork->work); @@ -1121,6 +1121,7 @@ static void delayed_work_timer_fn(unsigned long __data) __queue_work(smp_processor_id(), cwq->wq, &dwork->work); local_irq_enable(); } +EXPORT_SYMBOL_GPL(delayed_work_timer_fn); /** * queue_delayed_work_on - queue work on specific CPU after delay @@ -1145,6 +1146,8 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq, if (!test_and_set_bit(WORK_STRUCT_PENDING_BIT, work_data_bits(work))) { unsigned int lcpu; + WARN_ON_ONCE(timer->function != delayed_work_timer_fn || + timer->data != (unsigned long)dwork); BUG_ON(timer_pending(timer)); BUG_ON(!list_empty(&work->entry)); @@ -1168,8 +1171,6 @@ bool queue_delayed_work_on(int cpu, struct workqueue_struct *wq, set_work_cwq(work, get_cwq(lcpu, wq), 0); timer->expires = jiffies + delay; - timer->data = (unsigned long)dwork; - timer->function = delayed_work_timer_fn; if (unlikely(cpu >= 0)) add_timer_on(timer, cpu);