[PATCH AUTOSEL 4.14 073/127] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

Sasha Levin
2020-09-18T02:33:25Z

From: Pratik Rajesh Sampat <psampat@linux.ibm.com>

[ Upstream commit d95fe371ecd28901f11256c610b988ed44e36ee2 ]

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>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200316135743.57735-1-psampat@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 25c9a6cdd8614..dc81fc2bf8015 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -864,6 +864,7 @@ 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;

@@ -878,12 +879,14 @@ 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();
--
2.25.1