Re: [PATCH] powercap: DTPM: Fix the missing cpufreq_cpu_put() calls

[Lukasz Luba]

On 12/5/23 19:54, Rafael J. Wysocki wrote:
> On Fri, Dec 1, 2023 at 1:31 PM Lukasz Luba <lukasz.luba@xxxxxxx> wrote:
> > The policy returned by cpufreq_cpu_get() has to be released with
> > the help of cpufreq_cpu_put() to balance its kobject reference counter
> > properly.
> >
> > Add the missing calls to cpufreq_cpu_put() in the code.
> >
> > Fixes: 0aea2e4ec2a2 ("powercap/dtpm_cpu: Reset per_cpu variable in the release function")
> > Fixes: 0e8f68d7f048 ("powercap/drivers/dtpm: Add CPU energy model based support")
> > Cc: <stable@xxxxxxxxxxxxxxx> # v5.10+
> > Signed-off-by: Lukasz Luba <lukasz.luba@xxxxxxx>
> > ---
> >   drivers/powercap/dtpm_cpu.c | 17 +++++++++++++----
> >   1 file changed, 13 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/powercap/dtpm_cpu.c b/drivers/powercap/dtpm_cpu.c
> > index 45bb7e2849d7..aac278e162d9 100644
> > --- a/drivers/powercap/dtpm_cpu.c
> > +++ b/drivers/powercap/dtpm_cpu.c
> > @@ -152,6 +152,8 @@ static void pd_release(struct dtpm *dtpm)
> >          if (policy) {
> >                  for_each_cpu(dtpm_cpu->cpu, policy->related_cpus)
> >                          per_cpu(dtpm_per_cpu, dtpm_cpu->cpu) = NULL;
> > +
> > +               cpufreq_cpu_put(policy);
> >          }
> >
> >          kfree(dtpm_cpu);
> > @@ -204,12 +206,16 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
> >                  return 0;
> >
> >          pd = em_cpu_get(cpu);
> > -       if (!pd || em_is_artificial(pd))
> > -               return -EINVAL;
> > +       if (!pd || em_is_artificial(pd)) {
> > +               ret = -EINVAL;
> > +               goto release_policy;
> > +       }
> >
> >          dtpm_cpu = kzalloc(sizeof(*dtpm_cpu), GFP_KERNEL);
> > -       if (!dtpm_cpu)
> > -               return -ENOMEM;
> > +       if (!dtpm_cpu) {
> > +               ret = -ENOMEM;
> > +               goto release_policy;
> > +       }
> >
> >          dtpm_init(&dtpm_cpu->dtpm, &dtpm_ops);
> >          dtpm_cpu->cpu = cpu;
> > @@ -231,6 +237,7 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
> >          if (ret)
> >                  goto out_dtpm_unregister;
> >
> > +       cpufreq_cpu_put(policy);
> >          return 0;
> >
> >   out_dtpm_unregister:
> > @@ -242,6 +249,8 @@ static int __dtpm_cpu_setup(int cpu, struct dtpm *parent)
> >                  per_cpu(dtpm_per_cpu, cpu) = NULL;
> >          kfree(dtpm_cpu);
> >
> > +release_policy:
> > +       cpufreq_cpu_put(policy);
> >          return ret;
> >   }
> >
> > --
>
> Applied as 6.7-rc material with the Cc: stable tag fixed.
>
> Thanks!

Thank you Rafael!