On Fri, Nov 04, 2022 at 01:40:53AM -0400, Steven Rostedt wrote:
Back in April, I posted an RFC patch set to help mitigate a common issue where a timer gets armed just before it is freed, and when the timer goes off, it crashes in the timer code without any evidence of who the culprit was. I got side tracked and never finished up on that patch set. Since this type of crash is still our #1 crash we are seeing in the field, it has become a priority again to finish it.
This is v3 of that patch set. Thomas Gleixner posted an untested version that makes timer->function NULL as the flag that it is shutdown. I took that code, tested it (fixed it up), added more comments, and changed the name to timer_shutdown_sync(). I also converted it to use WARN_ON_ONCE() instead of just WARN_ON() as Linus asked for.
Unfortunately the renaming caused some symbol conflicts.
Global definition: timer_shutdown
File Line 0 time.c 93 static inline void timer_shutdown(struct clock_event_device *evt) 1 arm_arch_timer.c 690 static __always_inline int timer_shutdown(const int access, 2 timer-fttmr010.c 105 int (*timer_shutdown)(struct clock_event_device *evt); 3 timer-sp804.c 158 static inline void timer_shutdown(struct clock_event_device *evt) 4 timer.h 239 static inline int timer_shutdown(struct timer_list *timer)
Guenter