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    Subject[PATCH 5.4 129/411] Revert "cpufreq: Fix possible race in cpufreq online error path"
    Date
    From: Viresh Kumar <viresh.kumar@linaro.org>

    [ 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>
    ---
    drivers/cpufreq/cpufreq.c | 5 ++---
    1 file changed, 2 insertions(+), 3 deletions(-)

    diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
    index 7ea07764988e..af9f34804862 100644
    --- a/drivers/cpufreq/cpufreq.c
    +++ b/drivers/cpufreq/cpufreq.c
    @@ -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;
    --
    2.35.1


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