From 317f29c14d0cca09952f1022491454b23455ebcb Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Wed, 11 May 2022 13:19:51 -0700 Subject: [PATCH] timers: Provide a better debugobjects hint for delayed works With debugobjects enabled the timer hint for freeing of active timers embedded inside delayed works is always the same, i.e. the hint is delayed_work_timer_fn, even though the function the delayed work is going to run can be wildly different depending on what work was queued. Enabling workqueue debugobjects doesn't help either because the delayed work isn't considered active until it is actually queued to run on a workqueue. If the work is freed while the timer is pending the work isn't considered active so there is no information from workqueue debugobjects. Special case delayed works in the timer debugobjects hint logic so that the delayed work function is returned instead of the delayed_work_timer_fn. This will help to understand which delayed work was pending that got freed. Apply the same treatment for kthread_delayed_work because it follows the same pattern. Suggested-by: Thomas Gleixner Signed-off-by: Stephen Boyd Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/r/20220511201951.42408-1-swboyd@chromium.org --- kernel/time/timer.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) diff --git a/kernel/time/timer.c b/kernel/time/timer.c index ef082d43c307..a0666d948147 100644 --- a/kernel/time/timer.c +++ b/kernel/time/timer.c @@ -638,9 +638,39 @@ static void internal_add_timer(struct timer_base *base, struct timer_list *timer static const struct debug_obj_descr timer_debug_descr; +struct timer_hint { + void (*function)(struct timer_list *t); + long offset; +}; + +#define TIMER_HINT(fn, container, timr, hintfn) \ + { \ + .function = fn, \ + .offset = offsetof(container, hintfn) - \ + offsetof(container, timr) \ + } + +static const struct timer_hint timer_hints[] = { + TIMER_HINT(delayed_work_timer_fn, + struct delayed_work, timer, work.func), + TIMER_HINT(kthread_delayed_work_timer_fn, + struct kthread_delayed_work, timer, work.func), +}; + static void *timer_debug_hint(void *addr) { - return ((struct timer_list *) addr)->function; + struct timer_list *timer = addr; + int i; + + for (i = 0; i < ARRAY_SIZE(timer_hints); i++) { + if (timer_hints[i].function == timer->function) { + void (**fn)(void) = addr + timer_hints[i].offset; + + return *fn; + } + } + + return timer->function; } static bool timer_is_static_object(void *addr)