[PATCH V2] acpi-cpufreq: Fix an acpi perf unregister issue

[PATCH V2] acpi-cpufreq: Fix an acpi perf unregister issue

[Pan Xinhui]

As policy->cpu may not be same in acpi_cpufreq_cpu_init and
acpi_cpufreq_cpu_exit. There is a risk that we use different *cpu* to
un/register acpi performance. So acpi_processor_unregister_performance
may not be able to do the cleanup work. That causes a memory leak. And
if there will be another acpi_processor_register_performance call, it
may also fail thanks to the internal check of pr->performace.

So we add a field *acpi_perf_cpu* to fix this issue.

Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com>
---
Change from V1:
	comments update
---
 drivers/cpufreq/acpi-cpufreq.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
index 314a19e..8cad583 100644
--- a/drivers/cpufreq/acpi-cpufreq.c
+++ b/drivers/cpufreq/acpi-cpufreq.c
@@ -69,6 +69,7 @@ struct acpi_cpufreq_data {
 	struct cpufreq_frequency_table *freq_table;
 	unsigned int resume;
 	unsigned int cpu_feature;
+	unsigned int acpi_perf_cpu;
 	cpumask_var_t freqdomain_cpus;
 };
 
@@ -677,6 +678,7 @@ static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
 	}
 
 	data->acpi_data = per_cpu_ptr(acpi_perf_data, cpu);
+	data->acpi_perf_cpu = cpu;
 	policy->driver_data = data;
 
 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
@@ -861,7 +863,7 @@ static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
 	if (data) {
 		policy->driver_data = NULL;
 		acpi_processor_unregister_performance(data->acpi_data,
-						      policy->cpu);
+						      data->acpi_perf_cpu);
 		free_cpumask_var(data->freqdomain_cpus);
 		kfree(data->freq_table);
 		kfree(data);
-- 
1.9.1

Re: [PATCH V2] acpi-cpufreq: Fix an acpi perf unregister issue

[Viresh Kumar]

On 10-07-15, 14:36, Pan Xinhui wrote:
> 
> As policy->cpu may not be same in acpi_cpufreq_cpu_init and
> acpi_cpufreq_cpu_exit. There is a risk that we use different *cpu* to
> un/register acpi performance. So acpi_processor_unregister_performance
> may not be able to do the cleanup work. That causes a memory leak. And
> if there will be another acpi_processor_register_performance call, it
> may also fail thanks to the internal check of pr->performace.
> 
> So we add a field *acpi_perf_cpu* to fix this issue.
> 
> Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com>
> ---
> Change from V1:
> 	comments update
> ---
>  drivers/cpufreq/acpi-cpufreq.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Re: [PATCH V2] acpi-cpufreq: Fix an acpi perf unregister issue

[Rafael J. Wysocki]

On Monday, July 13, 2015 07:58:59 AM Viresh Kumar wrote:
> On 10-07-15, 14:36, Pan Xinhui wrote:
> > 
> > As policy->cpu may not be same in acpi_cpufreq_cpu_init and
> > acpi_cpufreq_cpu_exit. There is a risk that we use different *cpu* to
> > un/register acpi performance. So acpi_processor_unregister_performance
> > may not be able to do the cleanup work. That causes a memory leak. And
> > if there will be another acpi_processor_register_performance call, it
> > may also fail thanks to the internal check of pr->performace.
> > 
> > So we add a field *acpi_perf_cpu* to fix this issue.
> > 
> > Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com>
> > ---
> > Change from V1:
> > 	comments update
> > ---
> >  drivers/cpufreq/acpi-cpufreq.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Patch queued up for 4.3, thanks!


-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.