From 514ff1bcd98d7f57361025e2200b803d3ddde6c8 Mon Sep 17 00:00:00 2001 From: Schspa Shi Date: Mon, 16 May 2022 11:02:51 +0800 Subject: [PATCH] cpufreq: make interface functions and lock holding state clear cpufreq_offline() calls offline() and exit() under the policy rwsem But they are called outside the rwsem in cpufreq_online(). Make cpufreq_online() call offline() and exit() as well as online() and init() under the policy rwsem to achieve a clear lock relationship. All of the init() and online() implementations in the tree only initialize the policy object without attempting to acquire the policy rwsem and they won't call cpufreq APIs attempting to acquire it. Signed-off-by: Schspa Shi Acked-by: Viresh Kumar [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki --- drivers/cpufreq/cpufreq.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index f75197b924ef..2cad42774164 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1341,12 +1341,12 @@ static int cpufreq_online(unsigned int cpu) down_write(&policy->rwsem); policy->cpu = cpu; policy->governor = NULL; - up_write(&policy->rwsem); } else { new_policy = true; policy = cpufreq_policy_alloc(cpu); if (!policy) return -ENOMEM; + down_write(&policy->rwsem); } if (!new_policy && cpufreq_driver->online) { @@ -1386,7 +1386,6 @@ static int cpufreq_online(unsigned int cpu) cpumask_copy(policy->related_cpus, policy->cpus); } - down_write(&policy->rwsem); /* * affected cpus must always be the one, which are online. We aren't * managing offline cpus here. @@ -1538,7 +1537,6 @@ out_destroy_policy: remove_cpu_dev_symlink(policy, j, get_cpu_device(j)); cpumask_clear(policy->cpus); - up_write(&policy->rwsem); out_offline_policy: if (cpufreq_driver->offline) @@ -1549,6 +1547,8 @@ out_exit_policy: cpufreq_driver->exit(policy); out_free_policy: + up_write(&policy->rwsem); + cpufreq_policy_free(policy); return ret; }