Re: [RFC][PATCH] timers: Add del_time_free() to be called before freeing timers

[Steven Rostedt <rostedt@goodmis.org>]

On Fri, 08 Apr 2022 22:29:58 +0200
Thomas Gleixner <tglx@linutronix.de> wrote:

> Well, you'd have to reinitialize it first before the explicit rearm
> because the shutdown cleared the function pointer or if we use a flag
> then the flag would prevent arming it again.

We could always use the LSB bit of the function as a "shutdown" flag, where:

timer_shutdown() {
	[..]
	timer->fn = (void *)((unsigned long)timer->fn | 1);
	[..]
}

timer_rearm() {
	[..]
	timer->fn = (void *)((unsigned long)timer->fn & ~1UL);
	[..]
}

mod_timer() {

	if ((unsigned long)timer->fn & 1)
		return -EBUSY?;

	[..]
}

-- Steve