[PATCH 5.9 491/757] cpufreq: powernv: Fix frame-size-overflow in powernv_cpufreq_reboot_notifier

Greg Kroah-Hartman
2020-10-27T16:19:24Z

From: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

[ Upstream commit a2d0230b91f7e23ceb5d8fb6a9799f30517ec33a ]

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

drivers/cpufreq/powernv-cpufreq.c: In function powernv_cpufreq_reboot_notifier:
drivers/cpufreq/powernv-cpufreq.c:906:1: error: the frame size of 2064 bytes is larger than 2048 bytes

Fixes: cf30af76 ("cpufreq: powernv: Set the cpus to nominal frequency during reboot/kexec")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200922080254.41497-1-srikar@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/cpufreq/powernv-cpufreq.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/cpufreq/powernv-cpufreq.c b/drivers/cpufreq/powernv-cpufreq.c
index a9af15e994ccf..e439b43c19ebe 100644
--- a/drivers/cpufreq/powernv-cpufreq.c
+++ b/drivers/cpufreq/powernv-cpufreq.c
@@ -885,12 +885,15 @@ static int powernv_cpufreq_reboot_notifier(struct notifier_block *nb,
unsigned long action, void *unused)
{
int cpu;
- struct cpufreq_policy cpu_policy;
+ struct cpufreq_policy *cpu_policy;

rebooting = true;
for_each_online_cpu(cpu) {
- cpufreq_get_policy(&cpu_policy, cpu);
- powernv_cpufreq_target_index(&cpu_policy, get_nominal_index());
+ cpu_policy = cpufreq_cpu_get(cpu);
+ if (!cpu_policy)
+ continue;
+ powernv_cpufreq_target_index(cpu_policy, get_nominal_index());
+ cpufreq_cpu_put(cpu_policy);
}

return NOTIFY_DONE;
--
2.25.1