Commit be392aa8 authored by Jinjie Ruan's avatar Jinjie Ruan Committed by Viresh Kumar
Browse files

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



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

Fixes: 1a1374bb ("cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost()")
Reported-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/c4765377-7830-44c2-84fa-706b6e304e10@stanley.mountain/


Signed-off-by: default avatarJinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: default avatarQuentin Perret <qperret@google.com>
Signed-off-by: default avatarViresh Kumar <viresh.kumar@linaro.org>
parent db01e466

drivers/cpufreq/cppc_cpufreq.c

+1 −1
Original line number Diff line number Diff line
@@ -475,7 +475,7 @@ static int cppc_get_cpu_cost(struct device *cpu_dev, unsigned long KHz, 


	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;