[PATCH] powerpc/perf: double unlock bug in imc_common_cpuhp_mem_free()

[Michael Ellerman]

Dan Carpenter <dan.carpenter at oracle.com> writes:

> There is a typo so we call unlock instead of lock.
>
> Fixes: 885dcd709ba9 ("powerpc/perf: Add nest IMC PMU support")
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
> ---
> I also don't understand how the &nest_imc_refc[node_id].lock works.  Why
> can't we use ref->lock everywhere?  They seem equivalent, and my static
> checker complains if we call the same lock different names.

That looks like a bug to me, ie. we should always use ref.

Maddy?

cheers

> diff --git a/arch/powerpc/perf/imc-pmu.c b/arch/powerpc/perf/imc-pmu.c
> index 46cd912af060..52017f6eafd9 100644
> --- a/arch/powerpc/perf/imc-pmu.c
> +++ b/arch/powerpc/perf/imc-pmu.c
> @@ -1124,7 +1124,7 @@ static void cleanup_all_thread_imc_memory(void)
>  static void imc_common_cpuhp_mem_free(struct imc_pmu *pmu_ptr)
>  {
>  	if (pmu_ptr->domain == IMC_DOMAIN_NEST) {
> -		mutex_unlock(&nest_init_lock);
> +		mutex_lock(&nest_init_lock);
>  		if (nest_pmus == 1) {
>  			cpuhp_remove_state(CPUHP_AP_PERF_POWERPC_NEST_IMC_ONLINE);
>  			kfree(nest_imc_refc);