Re: [PATCH 12/13] kthread: Convert callback to use from_timer()

[Petr Mladek]

On Wed 2017-10-04 16:27:06, Kees Cook wrote:
> In preparation for unconditionally passing the struct timer_list pointer
> to all timer callbacks, switch kthread to use from_timer() and pass the
> timer pointer explicitly.
> 
> Cc: Andrew Morton 
> Cc: Petr Mladek 
> Cc: Tejun Heo 
> Cc: Thomas Gleixner 
> Cc: Oleg Nesterov 
> Signed-off-by: Kees Cook 

Reviewed-by: Petr Mladek 

Best Regards,
Petr

[PATCH 12/13] kthread: Convert callback to use from_timer()

[Kees Cook]

In preparation for unconditionally passing the struct timer_list pointer
to all timer callbacks, switch kthread to use from_timer() and pass the
timer pointer explicitly.

Cc: Andrew Morton 
Cc: Petr Mladek 
Cc: Tejun Heo 
Cc: Thomas Gleixner 
Cc: Oleg Nesterov 
Signed-off-by: Kees Cook 
---
 include/linux/kthread.h | 10 +-
 kernel/kthread.c| 10 --
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index 0d622b350d3f..35cbe3b0ce5b 100644
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -75,7 +75,7 @@ extern int tsk_fork_get_node(struct task_struct *tsk);
  */
 struct kthread_work;
 typedef void (*kthread_work_func_t)(struct kthread_work *work);
-void kthread_delayed_work_timer_fn(unsigned long __data);
+void kthread_delayed_work_timer_fn(struct timer_list *t);
 
 enum {
KTW_FREEZABLE   = 1 << 0,   /* freeze during suspend */
@@ -116,8 +116,8 @@ struct kthread_delayed_work {
 
 #define KTHREAD_DELAYED_WORK_INIT(dwork, fn) { \
.work = KTHREAD_WORK_INIT((dwork).work, (fn)),  \
-   .timer = __TIMER_INITIALIZER(kthread_delayed_work_timer_fn, \
-(unsigned long)&(dwork),   \
+   .timer = 
__TIMER_INITIALIZER((TIMER_FUNC_TYPE)kthread_delayed_work_timer_fn,\
+(TIMER_DATA_TYPE)&(dwork.timer),   \
 TIMER_IRQSAFE),\
}
 
@@ -164,8 +164,8 @@ extern void __kthread_init_worker(struct kthread_worker 
*worker,
do {\
kthread_init_work(&(dwork)->work, (fn));\
__setup_timer(&(dwork)->timer,  \
- kthread_delayed_work_timer_fn,\
- (unsigned long)(dwork),   \
+ (TIMER_FUNC_TYPE)kthread_delayed_work_timer_fn,\
+ (TIMER_DATA_TYPE)&(dwork)->timer, \
  TIMER_IRQSAFE);   \
} while (0)
 
diff --git a/kernel/kthread.c b/kernel/kthread.c
index 1c19edf82427..ba3992c8c375 100644
--- a/kernel/kthread.c
+++ b/kernel/kthread.c
@@ -798,15 +798,14 @@ EXPORT_SYMBOL_GPL(kthread_queue_work);
 /**
  * kthread_delayed_work_timer_fn - callback that queues the associated kthread
  * delayed work when the timer expires.
- * @__data: pointer to the data associated with the timer
+ * @t: pointer to the expired timer
  *
  * The format of the function is defined by struct timer_list.
  * It should have been called from irqsafe timer with irq already off.
  */
-void kthread_delayed_work_timer_fn(unsigned long __data)
+void kthread_delayed_work_timer_fn(struct timer_list *t)
 {
-   struct kthread_delayed_work *dwork =
-   (struct kthread_delayed_work *)__data;
+   struct kthread_delayed_work *dwork = from_timer(dwork, t, timer);
struct kthread_work *work = >work;
struct kthread_worker *worker = work->worker;
 
@@ -837,8 +836,7 @@ void __kthread_queue_delayed_work(struct kthread_worker 
*worker,
struct timer_list *timer = >timer;
struct kthread_work *work = >work;
 
-   WARN_ON_ONCE(timer->function != kthread_delayed_work_timer_fn ||
-timer->data != (unsigned long)dwork);
+   WARN_ON_ONCE(timer->function != 
(TIMER_FUNC_TYPE)kthread_delayed_work_timer_fn);
 
/*
 * If @delay is 0, queue @dwork->work immediately.  This is for
-- 
2.7.4