Commit f2e2e934 authored May 09, 2022 by Viresh Kumar Committed by Greg Kroah-Hartman Jun 14, 2022

Revert "cpufreq: Fix possible race in cpufreq online error path"



[ Upstream commit 85f0e42bd65d01b351d561efb38e584d4c596553 ]

This reverts commit f346e96267cd76175d6c201b40f770c0116a8a04.

The commit tried to fix a possible real bug but it made it even worse.
The fix was simply buggy as now an error out to out_offline_policy or
out_exit_policy will try to release a semaphore which was never taken in
the first place. This works fine only if we failed late, i.e. via
out_destroy_policy.

Fixes: f346e96267cd ("cpufreq: Fix possible race in cpufreq online error path")
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 1253811c

drivers/cpufreq/cpufreq.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -1509,6 +1509,8 @@ static int cpufreq_online(unsigned int cpu)
		for_each_cpu(j, policy->real_cpus)
		remove_cpu_dev_symlink(policy, get_cpu_device(j));

		up_write(&policy->rwsem);

		out_offline_policy:
		if (cpufreq_driver->offline)
		cpufreq_driver->offline(policy);
		@@ -1517,9 +1519,6 @@ static int cpufreq_online(unsigned int cpu)
		if (cpufreq_driver->exit)
		cpufreq_driver->exit(policy);

		cpumask_clear(policy->cpus);
		up_write(&policy->rwsem);

		out_free_policy:
		cpufreq_policy_free(policy);
		return ret;