Commit 40ea5685 authored Mar 21, 2020 by Daniel Lezcano

thermal/drivers/cpufreq_cooling: Remove abusing WARN_ON



The WARN_ON macros are used at the entry functions state2power() and
set_cur_state().

state2power() is called with the max_state retrieved from
get_max_state which returns cpufreq_cdev->max_level, then it check if
max_state is > cpufreq_cdev->max_level. The test does not really makes
sense but let's assume we want to make sure to catch an error if the
code evolves. However the WARN_ON is overkill.

set_cur_state() is also called from userspace if we write to the
sysfs. It is easy to see a stack dumped by just writing to sysfs
/sys/class/thermal/cooling_device0/cur_state a value greater than
"max_level". A bit scary. Returing -EINVAL is enough.

Remove these WARN_ON.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/r/20200321193107.21590-1-daniel.lezcano@linaro.org

parent ff44f672

drivers/thermal/cpufreq_cooling.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -273,7 +273,7 @@ static int cpufreq_state2power(struct thermal_cooling_device *cdev,
		struct cpufreq_cooling_device *cpufreq_cdev = cdev->devdata;

		/* Request state should be less than max_level */
		if (WARN_ON(state > cpufreq_cdev->max_level))
		if (state > cpufreq_cdev->max_level)
		return -EINVAL;

		num_cpus = cpumask_weight(cpufreq_cdev->policy->cpus);
		@@ -434,7 +434,7 @@ static int cpufreq_set_cur_state(struct thermal_cooling_device *cdev,
		int ret;

		/* Request state should be less than max_level */
		if (WARN_ON(state > cpufreq_cdev->max_level))
		if (state > cpufreq_cdev->max_level)
		return -EINVAL;

		/* Check if the old cooling action is same as new cooling action */

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