Re: [perf/x86] 8de4a00661: WARNING: CPU: 0 PID: 1 at kernel/locking/mutex-debug.c:80 debug_mutex_unlock+0x20c/0x2b3

[Thomas Gleixner]

On Wed, 13 Jul 2016, kernel test robot wrote:
> [    1.863354] WARNING: CPU: 0 PID: 1 at kernel/locking/mutex-debug.c:80 debug_mutex_unlock+0x20c/0x2b3
> [    1.877193] DEBUG_LOCKS_WARN_ON(lock->owner != current)
> 
> [    1.979431]  [<ffffffff8167508c>] mutex_unlock+0x9/0xb
> [    1.979431]  [<ffffffff8167508c>] mutex_unlock+0x9/0xb
> [    1.990691]  [<ffffffff8105a67f>] cpuhp_store_callbacks+0x5a/0x63

I have a hard time to figure out how that can happen:

static void cpuhp_store_callbacks(enum cpuhp_state state,
                                  const char *name,
                                  int (*startup)(unsigned int cpu),
                                  int (*teardown)(unsigned int cpu))
{
        /* (Un)Install the callbacks for further cpu hotplug operations */
        struct cpuhp_step *sp;

        mutex_lock(&cpuhp_state_mutex);
 	sp = cpuhp_get_step(state);
	sp->startup = startup;
        sp->teardown = teardown;
        sp->name = name;
        mutex_unlock(&cpuhp_state_mutex);
}

Confused ....