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

[Madhavan Srinivasan]

On Monday 14 August 2017 09:00 AM, Michael Ellerman wrote:

Dan Carpenter <dan.carpen...@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.carpen...@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.

ok. will send a fix.

Thanks
Maddy

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);