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

[ Upstream commit b51eb0874d8170028434fbd259e80b78ed9b8eca ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 27508b396846e02f79588146c9bd739fb7cf6fc8..6bea89bfe3e95ac8ec95272323b086b356f8f62f 100644 (file)
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -424,7 +424,7 @@ 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;