[PATCH AUTOSEL 4.9 56/90] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_work_fn

[Sasha Levin]

From: Pratik Rajesh Sampat <psam...@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 <psam...@linux.ibm.com>
Reviewed-by: Daniel Axtens <d...@axtens.net>
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
Link: https://lore.kernel.org/r/20200316135743.57735-1-psam...@linux.ibm.com
Signed-off-by: Sasha Levin <sas...@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 b4fc65512aad3..c3b05676e0dbe 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -802,6 +802,7 @@ 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;
 
@@ -816,12 +817,14 @@ 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