2020-03-16 14:00:01

by Pratik R. Sampat

Subject: [PATCH] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

The patch avoids allocating cpufreq_policy on stack hence fixing frame
size overflow in 'powernv_cpufreq_work_fn'

Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
Signed-off-by: Pratik Rajesh Sampat <[email protected]>
---
drivers/cpufreq/powernv-cpufreq.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index 56f4bc0d209e..20ee0661555a 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -902,6 +902,7 @@ static struct notifier_block powernv_cpufreq_reboot_nb = {
void powernv_cpufreq_work_fn(struct work_struct *work)
{
struct chip *chip = container_of(work, struct chip, throttle);
+ struct cpufreq_policy *policy;
unsigned int cpu;
cpumask_t mask;

@@ -916,12 +917,14 @@ void powernv_cpufreq_work_fn(struct work_struct *work)
chip->restore = false;
for_each_cpu(cpu, &mask) {
int index;
- struct cpufreq_policy policy;

- cpufreq_get_policy(&policy, cpu);
- index = cpufreq_table_find_index_c(&policy, policy.cur);
- powernv_cpufreq_target_index(&policy, index);
- cpumask_andnot(&mask, &mask, policy.cpus);
+ policy = cpufreq_cpu_get(cpu);
+ if (!policy)
+ continue;
+ index = cpufreq_table_find_index_c(policy, policy->cur);
+ powernv_cpufreq_target_index(policy, index);
+ cpumask_andnot(&mask, &mask, policy->cpus);
+ cpufreq_cpu_put(policy);
}
out:
put_online_cpus();
--
2.24.1

2020-03-17 22:34:13

by Daniel Axtens

Subject: Re: [PATCH] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

Hi Pratik,

Thanks.

I have checked:

- for matching puts/gets
- that all the '.' to '->' conversions, aud uses of '&' check out
- that the Snowpatch checks pass (https://patchwork.ozlabs.org/patch/1255580/)

On that basis:

Reviewed-by: Daniel Axtens <[email protected]>

Regards,
Daniel

> The patch avoids allocating cpufreq_policy on stack hence fixing frame
> size overflow in 'powernv_cpufreq_work_fn'
>
> Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
> Signed-off-by: Pratik Rajesh Sampat <[email protected]>
> ---
> drivers/cpufreq/powernv-cpufreq.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index 56f4bc0d209e..20ee0661555a 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -902,6 +902,7 @@ static struct notifier_block powernv_cpufreq_reboot_nb = {
> void powernv_cpufreq_work_fn(struct work_struct *work)
> {
> struct chip *chip = container_of(work, struct chip, throttle);
> + struct cpufreq_policy *policy;
> unsigned int cpu;
> cpumask_t mask;
>
> @@ -916,12 +917,14 @@ void powernv_cpufreq_work_fn(struct work_struct *work)
> chip->restore = false;
> for_each_cpu(cpu, &mask) {
> int index;
> - struct cpufreq_policy policy;
>
> - cpufreq_get_policy(&policy, cpu);
> - index = cpufreq_table_find_index_c(&policy, policy.cur);
> - powernv_cpufreq_target_index(&policy, index);
> - cpumask_andnot(&mask, &mask, policy.cpus);
> + policy = cpufreq_cpu_get(cpu);
> + if (!policy)
> + continue;
> + index = cpufreq_table_find_index_c(policy, policy->cur);
> + powernv_cpufreq_target_index(policy, index);
> + cpumask_andnot(&mask, &mask, policy->cpus);
> + cpufreq_cpu_put(policy);
> }
> out:
> put_online_cpus();
> --
> 2.24.1

2020-03-19 10:19:52

by Rafael J. Wysocki

Subject: Re: [PATCH] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

On Monday, March 16, 2020 2:57:43 PM CET Pratik Rajesh Sampat wrote:
> The patch avoids allocating cpufreq_policy on stack hence fixing frame
> size overflow in 'powernv_cpufreq_work_fn'
>
> Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
> Signed-off-by: Pratik Rajesh Sampat <[email protected]>

Any objections or concerns here?

If not, I'll queue it up.

> ---
> drivers/cpufreq/powernv-cpufreq.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index 56f4bc0d209e..20ee0661555a 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -902,6 +902,7 @@ static struct notifier_block powernv_cpufreq_reboot_nb = {
> void powernv_cpufreq_work_fn(struct work_struct *work)
> {
> struct chip *chip = container_of(work, struct chip, throttle);
> + struct cpufreq_policy *policy;
> unsigned int cpu;
> cpumask_t mask;
>
> @@ -916,12 +917,14 @@ void powernv_cpufreq_work_fn(struct work_struct *work)
> chip->restore = false;
> for_each_cpu(cpu, &mask) {
> int index;
> - struct cpufreq_policy policy;
>
> - cpufreq_get_policy(&policy, cpu);
> - index = cpufreq_table_find_index_c(&policy, policy.cur);
> - powernv_cpufreq_target_index(&policy, index);
> - cpumask_andnot(&mask, &mask, policy.cpus);
> + policy = cpufreq_cpu_get(cpu);
> + if (!policy)
> + continue;
> + index = cpufreq_table_find_index_c(policy, policy->cur);
> + powernv_cpufreq_target_index(policy, index);
> + cpumask_andnot(&mask, &mask, policy->cpus);
> + cpufreq_cpu_put(policy);
> }
> out:
> put_online_cpus();
>

2020-03-20 10:39:14

by Gautham R Shenoy

Subject: Re: [PATCH] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

On Mon, Mar 16, 2020 at 07:27:43PM +0530, Pratik Rajesh Sampat wrote:
> The patch avoids allocating cpufreq_policy on stack hence fixing frame
> size overflow in 'powernv_cpufreq_work_fn'
>

Thanks for fixing this.

> Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
> Signed-off-by: Pratik Rajesh Sampat <[email protected]>

Reviewed-by: Gautham R. Shenoy <[email protected]>

> ---
> drivers/cpufreq/powernv-cpufreq.c | 13 ++++++++-----
> 1 file changed, 8 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
> index 56f4bc0d209e..20ee0661555a 100644
> --- a/drivers/cpufreq/powernv-cpufreq.c
> +++ b/drivers/cpufreq/powernv-cpufreq.c
> @@ -902,6 +902,7 @@ static struct notifier_block powernv_cpufreq_reboot_nb = {
> void powernv_cpufreq_work_fn(struct work_struct *work)
> {
> struct chip *chip = container_of(work, struct chip, throttle);
> + struct cpufreq_policy *policy;
> unsigned int cpu;
> cpumask_t mask;
>
> @@ -916,12 +917,14 @@ void powernv_cpufreq_work_fn(struct work_struct *work)
> chip->restore = false;
> for_each_cpu(cpu, &mask) {
> int index;
> - struct cpufreq_policy policy;
>
> - cpufreq_get_policy(&policy, cpu);
> - index = cpufreq_table_find_index_c(&policy, policy.cur);
> - powernv_cpufreq_target_index(&policy, index);
> - cpumask_andnot(&mask, &mask, policy.cpus);
> + policy = cpufreq_cpu_get(cpu);
> + if (!policy)
> + continue;
> + index = cpufreq_table_find_index_c(policy, policy->cur);
> + powernv_cpufreq_target_index(policy, index);
> + cpumask_andnot(&mask, &mask, policy->cpus);
> + cpufreq_cpu_put(policy);
> }
> out:
> put_online_cpus();
> --
> 2.24.1
>

2020-03-24 06:35:24

by Michael Ellerman

Subject: Re: [PATCH] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

"Rafael J. Wysocki" <[email protected]> writes:
> On Monday, March 16, 2020 2:57:43 PM CET Pratik Rajesh Sampat wrote:
>> The patch avoids allocating cpufreq_policy on stack hence fixing frame
>> size overflow in 'powernv_cpufreq_work_fn'
>>
>> Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
>> Signed-off-by: Pratik Rajesh Sampat <[email protected]>
>
> Any objections or concerns here?
>
> If not, I'll queue it up.

I have it in my testing branch, but if you pick it up I can drop it.

cheers

>> diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
>> index 56f4bc0d209e..20ee0661555a 100644
>> --- a/drivers/cpufreq/powernv-cpufreq.c
>> +++ b/drivers/cpufreq/powernv-cpufreq.c
>> @@ -902,6 +902,7 @@ static struct notifier_block powernv_cpufreq_reboot_nb = {
>> void powernv_cpufreq_work_fn(struct work_struct *work)
>> {
>> struct chip *chip = container_of(work, struct chip, throttle);
>> + struct cpufreq_policy *policy;
>> unsigned int cpu;
>> cpumask_t mask;
>>
>> @@ -916,12 +917,14 @@ void powernv_cpufreq_work_fn(struct work_struct *work)
>> chip->restore = false;
>> for_each_cpu(cpu, &mask) {
>> int index;
>> - struct cpufreq_policy policy;
>>
>> - cpufreq_get_policy(&policy, cpu);
>> - index = cpufreq_table_find_index_c(&policy, policy.cur);
>> - powernv_cpufreq_target_index(&policy, index);
>> - cpumask_andnot(&mask, &mask, policy.cpus);
>> + policy = cpufreq_cpu_get(cpu);
>> + if (!policy)
>> + continue;
>> + index = cpufreq_table_find_index_c(policy, policy->cur);
>> + powernv_cpufreq_target_index(policy, index);
>> + cpumask_andnot(&mask, &mask, policy->cpus);
>> + cpufreq_cpu_put(policy);
>> }
>> out:
>> put_online_cpus();
>>

2020-03-25 10:36:53

by Rafael J. Wysocki

Subject: Re: [PATCH] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

On Tuesday, March 24, 2020 7:34:56 AM CET Michael Ellerman wrote:
> "Rafael J. Wysocki" <[email protected]> writes:
> > On Monday, March 16, 2020 2:57:43 PM CET Pratik Rajesh Sampat wrote:
> >> The patch avoids allocating cpufreq_policy on stack hence fixing frame
> >> size overflow in 'powernv_cpufreq_work_fn'
> >>
> >> Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
> >> Signed-off-by: Pratik Rajesh Sampat <[email protected]>
> >
> > Any objections or concerns here?
> >
> > If not, I'll queue it up.
>
> I have it in my testing branch,

Great!

> but if you pick it up I can drop it.

Let it go in through your tree.

Cheers!

2020-03-26 12:08:03

by Michael Ellerman

Subject: Re: [PATCH] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

On Mon, 2020-03-16 at 13:57:43 UTC, Pratik Rajesh Sampat wrote:
> The patch avoids allocating cpufreq_policy on stack hence fixing frame
> size overflow in 'powernv_cpufreq_work_fn'
>
> Fixes: 227942809b52 ("cpufreq: powernv: Restore cpu frequency to policy->cur on unthrottling")
> Signed-off-by: Pratik Rajesh Sampat <[email protected]>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/d95fe371ecd28901f11256c610b988ed44e36ee2

cheers