[PATCH v1 01/10] cpufreq: Reference count policy in cpufreq_update_limits()

Posted by Rafael J. Wysocki 8 months, 3 weeks ago

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Since acpi_processor_notify() can be called before registering a cpufreq
driver or even in cases when a cpufreq driver is not registered at all,
cpufreq_update_limits() needs to check if a cpufreq driver is present
and prevent it from being unregistered.

For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq
policy pointer for the given CPU and reference count the corresponding
policy object, if present.

Fixes: 5a25e3f7cc53 ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates")
Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl
Reporetd-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> 
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/cpufreq/cpufreq.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2781,6 +2781,12 @@
  */
 void cpufreq_update_limits(unsigned int cpu)
 {
+	struct cpufreq_policy *policy __free(put_cpufreq_policy);
+
+	policy = cpufreq_cpu_get(cpu);
+	if (!policy)
+		return;
+
 	if (cpufreq_driver->update_limits)
 		cpufreq_driver->update_limits(cpu);
 	else

Re: [PATCH v1 01/10] cpufreq: Reference count policy in cpufreq_update_limits()

Posted by Marek Marczykowski-Górecki 8 months ago

On Fri, Mar 28, 2025 at 09:39:08PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Since acpi_processor_notify() can be called before registering a cpufreq
> driver or even in cases when a cpufreq driver is not registered at all,
> cpufreq_update_limits() needs to check if a cpufreq driver is present
> and prevent it from being unregistered.
> 
> For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq
> policy pointer for the given CPU and reference count the corresponding
> policy object, if present.
> 
> Fixes: 5a25e3f7cc53 ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates")
> Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl
> Reporetd-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> 
> Cc: All applicable <stable@vger.kernel.org>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

It looks like this patch is missing in stable branches.

> ---
>  drivers/cpufreq/cpufreq.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -2781,6 +2781,12 @@
>   */
>  void cpufreq_update_limits(unsigned int cpu)
>  {
> +	struct cpufreq_policy *policy __free(put_cpufreq_policy);
> +
> +	policy = cpufreq_cpu_get(cpu);
> +	if (!policy)
> +		return;
> +
>  	if (cpufreq_driver->update_limits)
>  		cpufreq_driver->update_limits(cpu);
>  	else
> 
> 
> 

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

Re: [PATCH v1 01/10] cpufreq: Reference count policy in cpufreq_update_limits()

Posted by Rafael J. Wysocki 8 months ago

On Tue, Apr 15, 2025 at 3:08 PM Marek Marczykowski-Górecki
<marmarek@invisiblethingslab.com> wrote:
>
> On Fri, Mar 28, 2025 at 09:39:08PM +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > Since acpi_processor_notify() can be called before registering a cpufreq
> > driver or even in cases when a cpufreq driver is not registered at all,
> > cpufreq_update_limits() needs to check if a cpufreq driver is present
> > and prevent it from being unregistered.
> >
> > For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq
> > policy pointer for the given CPU and reference count the corresponding
> > policy object, if present.
> >
> > Fixes: 5a25e3f7cc53 ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates")
> > Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl
> > Reporetd-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
> > Cc: All applicable <stable@vger.kernel.org>
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
>
> It looks like this patch is missing in stable branches.

It may have not been picked up by the "stable" maintainers yet.

> > ---
> >  drivers/cpufreq/cpufreq.c |    6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > --- a/drivers/cpufreq/cpufreq.c
> > +++ b/drivers/cpufreq/cpufreq.c
> > @@ -2781,6 +2781,12 @@
> >   */
> >  void cpufreq_update_limits(unsigned int cpu)
> >  {
> > +     struct cpufreq_policy *policy __free(put_cpufreq_policy);
> > +
> > +     policy = cpufreq_cpu_get(cpu);
> > +     if (!policy)
> > +             return;
> > +
> >       if (cpufreq_driver->update_limits)
> >               cpufreq_driver->update_limits(cpu);
> >       else
> >
> >
> >
>
> --
> Best Regards,
> Marek Marczykowski-Górecki
> Invisible Things Lab

Re: [PATCH v1 01/10] cpufreq: Reference count policy in cpufreq_update_limits()

Posted by Viresh Kumar 8 months, 2 weeks ago

On 28-03-25, 21:39, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Since acpi_processor_notify() can be called before registering a cpufreq
> driver or even in cases when a cpufreq driver is not registered at all,
> cpufreq_update_limits() needs to check if a cpufreq driver is present
> and prevent it from being unregistered.
> 
> For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq
> policy pointer for the given CPU and reference count the corresponding
> policy object, if present.
> 
> Fixes: 5a25e3f7cc53 ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates")
> Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl
> Reporetd-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> 
> Cc: All applicable <stable@vger.kernel.org>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/cpufreq/cpufreq.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -2781,6 +2781,12 @@
>   */
>  void cpufreq_update_limits(unsigned int cpu)
>  {
> +	struct cpufreq_policy *policy __free(put_cpufreq_policy);
> +
> +	policy = cpufreq_cpu_get(cpu);
> +	if (!policy)
> +		return;
> +
>  	if (cpufreq_driver->update_limits)
>  		cpufreq_driver->update_limits(cpu);
>  	else

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

-- 
viresh

Re: [PATCH v1 01/10] cpufreq: Reference count policy in cpufreq_update_limits()

Posted by Rafael J. Wysocki 8 months, 2 weeks ago

On Tue, Apr 1, 2025 at 10:30 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On 28-03-25, 21:39, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > Since acpi_processor_notify() can be called before registering a cpufreq
> > driver or even in cases when a cpufreq driver is not registered at all,
> > cpufreq_update_limits() needs to check if a cpufreq driver is present
> > and prevent it from being unregistered.
> >
> > For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq
> > policy pointer for the given CPU and reference count the corresponding
> > policy object, if present.
> >
> > Fixes: 5a25e3f7cc53 ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates")
> > Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl
> > Reporetd-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
> > Cc: All applicable <stable@vger.kernel.org>
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> >  drivers/cpufreq/cpufreq.c |    6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > --- a/drivers/cpufreq/cpufreq.c
> > +++ b/drivers/cpufreq/cpufreq.c
> > @@ -2781,6 +2781,12 @@
> >   */
> >  void cpufreq_update_limits(unsigned int cpu)
> >  {
> > +     struct cpufreq_policy *policy __free(put_cpufreq_policy);
> > +
> > +     policy = cpufreq_cpu_get(cpu);
> > +     if (!policy)
> > +             return;
> > +
> >       if (cpufreq_driver->update_limits)
> >               cpufreq_driver->update_limits(cpu);
> >       else
>
> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

Thanks for all of the ACKs!

Re: [PATCH v1 01/10] cpufreq: Reference count policy in cpufreq_update_limits()

Posted by Marek Marczykowski-Górecki 8 months, 3 weeks ago

On Fri, Mar 28, 2025 at 09:39:08PM +0100, Rafael J. Wysocki wrote:
> From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> 
> Since acpi_processor_notify() can be called before registering a cpufreq
> driver or even in cases when a cpufreq driver is not registered at all,
> cpufreq_update_limits() needs to check if a cpufreq driver is present
> and prevent it from being unregistered.
> 
> For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq
> policy pointer for the given CPU and reference count the corresponding
> policy object, if present.
> 
> Fixes: 5a25e3f7cc53 ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates")
> Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl
> Reporetd-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>

Reported

I wanted to propose also Tested-by tag, but technically it's not me who
tested it: https://forum.qubes-os.org/t/kernel-latest-6-13-6-boot-loop/32926/18

> Cc: All applicable <stable@vger.kernel.org>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/cpufreq/cpufreq.c |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> --- a/drivers/cpufreq/cpufreq.c
> +++ b/drivers/cpufreq/cpufreq.c
> @@ -2781,6 +2781,12 @@
>   */
>  void cpufreq_update_limits(unsigned int cpu)
>  {
> +	struct cpufreq_policy *policy __free(put_cpufreq_policy);
> +
> +	policy = cpufreq_cpu_get(cpu);
> +	if (!policy)
> +		return;
> +
>  	if (cpufreq_driver->update_limits)
>  		cpufreq_driver->update_limits(cpu);
>  	else
> 
> 
> 

-- 
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab

Re: [PATCH v1 01/10] cpufreq: Reference count policy in cpufreq_update_limits()

Posted by Rafael J. Wysocki 8 months, 3 weeks ago

On Sat, Mar 29, 2025 at 3:02 AM Marek Marczykowski-Górecki
<marmarek@invisiblethingslab.com> wrote:
>
> On Fri, Mar 28, 2025 at 09:39:08PM +0100, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> >
> > Since acpi_processor_notify() can be called before registering a cpufreq
> > driver or even in cases when a cpufreq driver is not registered at all,
> > cpufreq_update_limits() needs to check if a cpufreq driver is present
> > and prevent it from being unregistered.
> >
> > For this purpose, make it call cpufreq_cpu_get() to obtain a cpufreq
> > policy pointer for the given CPU and reference count the corresponding
> > policy object, if present.
> >
> > Fixes: 5a25e3f7cc53 ("cpufreq: intel_pstate: Driver-specific handling of _PPC updates")
> > Closes: https://lore.kernel.org/linux-acpi/Z-ShAR59cTow0KcR@mail-itl
> > Reporetd-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
>
> Reported

Right, thanks!

> I wanted to propose also Tested-by tag, but technically it's not me who
> tested it: https://forum.qubes-os.org/t/kernel-latest-6-13-6-boot-loop/32926/18

You can ask the original tester whether or not they would be willing
to give a tag, though.

> > Cc: All applicable <stable@vger.kernel.org>
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> > ---
> >  drivers/cpufreq/cpufreq.c |    6 ++++++
> >  1 file changed, 6 insertions(+)
> >
> > --- a/drivers/cpufreq/cpufreq.c
> > +++ b/drivers/cpufreq/cpufreq.c
> > @@ -2781,6 +2781,12 @@
> >   */
> >  void cpufreq_update_limits(unsigned int cpu)
> >  {
> > +     struct cpufreq_policy *policy __free(put_cpufreq_policy);
> > +
> > +     policy = cpufreq_cpu_get(cpu);
> > +     if (!policy)
> > +             return;
> > +
> >       if (cpufreq_driver->update_limits)
> >               cpufreq_driver->update_limits(cpu);
> >       else
> >
> >
> >
>
> --
> Best Regards,
> Marek Marczykowski-Górecki
> Invisible Things Lab