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

BugLink: https://bugs.launchpad.net/bugs/2101915

[ Upstream commit be392aa80f1e5b0b65ccc2a540b9304fefcfe3d8 ]

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: 1a1374bb8c59 ("cpufreq: CPPC: Fix possible null-ptr-deref for cppc_get_cpu_cost()")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/all/c4765377-7830-44c2-84fa-706b6e304e10@stanley.mountain/
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>
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

This commit is contained in:

Jinjie Ruan

2025-03-11 08:51:19 +09:00

committed by

Stefan Bader

parent a5867e8152

commit 5bef1be7ea

1 changed files with 1 additions and 1 deletions

									
										drivers/cpufreq/cppc_cpufreq.c
									
		+1
		-1
	
												View File
												
				@@ -499,7 +499,7 @@ 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;