cpufreq: CPPC: Fix wrong return value in cppc_get_cpu_power()

cppc_get_cpu_power() return 0 if the policy is NULL. Then in
em_create_perf_table(), the later zero check for power is not valid
as power is uninitialized. As Quentin pointed out, kernel energy model
core check the return value of active_power() first, so if the callback
failed it should tell the core. So return -EINVAL to fix it.

Fixes: a78e72075642 ("cpufreq: CPPC: Fix possible null-ptr-deref for cpufreq_cpu_get_raw()")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Quentin Perret <qperret@google.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 4e1d0c7ccb1f9250bc329afb5fcafaee2c27b3b7..c68ac76810aac353dc84dd66293a5663f64232d5 100644 (file)
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -405,7 +405,7 @@ static int cppc_get_cpu_power(struct device *cpu_dev,
 
        policy = cpufreq_cpu_get_raw(cpu_dev->id);
        if (!policy)
-               return 0;
+               return -EINVAL;
 
        cpu_data = policy->driver_data;
        perf_caps = &cpu_data->perf_caps;