From: Lianwei Wang <a22...@motorola.com>
The cpufreq TRANSTION notifier callback does not check the
governor_enabled state on affected CPUS, which will case
kernel panic in update_load because the policy object maybe
NULL or invalid when governor_enabled is false.
Change-Id: Ie0f1718124f61e2f9b5da57abc6981ada5b83908
Signed-off-by: Lianwei Wang <a22...@motorola.com>
Signed-off-by: Bálint Czobor <czoborbal...@gmail.com>
---
drivers/cpufreq/cpufreq_interactive.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/cpufreq/cpufreq_interactive.c
b/drivers/cpufreq/cpufreq_interactive.c
index 7303f50..691923d 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -634,9 +634,19 @@ static int cpufreq_interactive_notifier(
for_each_cpu(cpu, pcpu->policy->cpus) {
struct cpufreq_interactive_cpuinfo *pjcpu =
&per_cpu(cpuinfo, cpu);
+ if (cpu != freq->cpu) {
+ if (!down_read_trylock(&pjcpu->enable_sem))
+ continue;
+ if (!pjcpu->governor_enabled) {
+ up_read(&pjcpu->enable_sem);
+ continue;
+ }
+ }
spin_lock_irqsave(&pjcpu->load_lock, flags);
update_load(cpu);
spin_unlock_irqrestore(&pjcpu->load_lock, flags);
+ if (cpu != freq->cpu)
+ up_read(&pjcpu->enable_sem);
}
up_read(&pcpu->enable_sem);
--
1.7.9.5
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