diff options
| author | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-05-11 18:51:39 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-16 14:28:34 +0300 |
| commit | e660a2e670dc5c6e33e5607472d09000bc975714 (patch) | |
| tree | 389f0dcf2453b0984ef8eacd88f21bf20c5a90a1 /drivers | |
| parent | 14bef1ad614e59c99c35b981cb72dfc439fa7f93 (diff) | |
| download | linux-e660a2e670dc5c6e33e5607472d09000bc975714.tar.xz | |
cpufreq: Rearrange locking in cpufreq_remove_dev()
[ Upstream commit f339f3541701d824a0256ad4bf14c26ceb6d79c3 ]
Currently, cpufreq_remove_dev() invokes the ->exit() driver callback
without holding the policy rwsem which is inconsistent with what
happens if ->exit() is invoked directly from cpufreq_offline().
It also manipulates the real_cpus mask and removes the CPU device
symlink without holding the policy rwsem, but cpufreq_offline() holds
the rwsem around the modifications thereof.
For consistency, modify cpufreq_remove_dev() to hold the policy rwsem
until the ->exit() callback has been called (or it has been determined
that it is not necessary to call it).
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Stable-dep-of: b8f85833c057 ("cpufreq: exit() callback is optional")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 549788a2a967..e727282f5696 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1639,19 +1639,26 @@ static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) if (!policy) return; + down_write(&policy->rwsem); + if (cpu_online(cpu)) - cpufreq_offline(cpu); + __cpufreq_offline(cpu, policy); cpumask_clear_cpu(cpu, policy->real_cpus); remove_cpu_dev_symlink(policy, dev); - if (cpumask_empty(policy->real_cpus)) { - /* We did light-weight exit earlier, do full tear down now */ - if (cpufreq_driver->offline) - cpufreq_driver->exit(policy); - - cpufreq_policy_free(policy); + if (!cpumask_empty(policy->real_cpus)) { + up_write(&policy->rwsem); + return; } + + /* We did light-weight exit earlier, do full tear down now */ + if (cpufreq_driver->offline) + cpufreq_driver->exit(policy); + + up_write(&policy->rwsem); + + cpufreq_policy_free(policy); } /** |