diff mbox series

cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

Message ID 20200316135743.57735-1-psampat@linux.ibm.com (mailing list archive)
State Accepted
Commit d95fe371ecd28901f11256c610b988ed44e36ee2
Headers show
Series cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (ab326587bb5fb91cc97df9b9f48e9e1469f04621)
snowpatch_ozlabs/build-ppc64le success Build succeeded
snowpatch_ozlabs/build-ppc64be success Build succeeded
snowpatch_ozlabs/build-ppc64e success Build succeeded
snowpatch_ozlabs/build-pmac32 success Build succeeded
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 26 lines checked
snowpatch_ozlabs/needsstable warning Please consider tagging this patch for stable!

Commit Message

Pratik R. Sampat March 16, 2020, 1:57 p.m. UTC
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 <psampat@linux.ibm.com>
---
 drivers/cpufreq/powernv-cpufreq.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

Comments

Daniel Axtens March 17, 2020, 10:30 p.m. UTC | #1
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 <dja@axtens.net>

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 <psampat@linux.ibm.com>
> ---
>  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
Rafael J. Wysocki March 19, 2020, 10:18 a.m. UTC | #2
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 <psampat@linux.ibm.com>

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();
>
Gautham R Shenoy March 20, 2020, 10:37 a.m. UTC | #3
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 <psampat@linux.ibm.com>

Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>

> ---
>  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
>
Michael Ellerman March 24, 2020, 6:34 a.m. UTC | #4
"Rafael J. Wysocki" <rjw@rjwysocki.net> 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 <psampat@linux.ibm.com>
>
> 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();
>>
Rafael J. Wysocki March 25, 2020, 10:36 a.m. UTC | #5
On Tuesday, March 24, 2020 7:34:56 AM CET Michael Ellerman wrote:
> "Rafael J. Wysocki" <rjw@rjwysocki.net> 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 <psampat@linux.ibm.com>
> >
> > 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!
Michael Ellerman March 26, 2020, 12:06 p.m. UTC | #6
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 <psampat@linux.ibm.com>

Applied to powerpc next, thanks.

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

cheers
diff mbox series

Patch

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();