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| author |   Schspa Shi <schspa@gmail.com> | 2022-05-16 11:02:50 +0800 |
|---|---|---|
| committer |   Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2022-05-17 21:39:04 +0200 |
| commit | d4627a287e251efed59f2b4bda82c5950768c963 (patch) | |
| tree | 146bae98dcd7549b946885647acdbf4a1385cf56 /drivers/cpufreq | |
| parent | cpufreq: Rearrange locking in cpufreq_remove_dev() (diff) | |
| download | wireguard-linux-d4627a287e251efed59f2b4bda82c5950768c963.tar.xz wireguard-linux-d4627a287e251efed59f2b4bda82c5950768c963.zip | |
cpufreq: Abort show()/store() for half-initialized policies
If policy initialization fails after the sysfs files are created,
there is a possibility to end up running show()/store() callbacks
for half-initialized policies, which may have unpredictable
outcomes.
Abort show()/store() in such a case by making sure the policy is active.
Also dectivate the policy on such failures.
Signed-off-by: Schspa Shi <schspa@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/cpufreq')
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 1f6667ce43bd..f75197b924ef 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -948,13 +948,14 @@ static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) { struct cpufreq_policy *policy = to_policy(kobj); struct freq_attr *fattr = to_attr(attr); - ssize_t ret; + ssize_t ret = -EBUSY; if (!fattr->show) return -EIO; down_read(&policy->rwsem); - ret = fattr->show(policy, buf); + if (likely(!policy_is_inactive(policy))) + ret = fattr->show(policy, buf); up_read(&policy->rwsem); return ret; @@ -965,7 +966,7 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, { struct cpufreq_policy *policy = to_policy(kobj); struct freq_attr *fattr = to_attr(attr); - ssize_t ret = -EINVAL; + ssize_t ret = -EBUSY; if (!fattr->store) return -EIO; @@ -979,7 +980,8 @@ static ssize_t store(struct kobject *kobj, struct attribute *attr, if (cpu_online(policy->cpu)) { down_write(&policy->rwsem); - ret = fattr->store(policy, buf, count); + if (likely(!policy_is_inactive(policy))) + ret = fattr->store(policy, buf, count); up_write(&policy->rwsem); } @@ -1535,6 +1537,7 @@ out_destroy_policy: for_each_cpu(j, policy->real_cpus) remove_cpu_dev_symlink(policy, j, get_cpu_device(j)); + cpumask_clear(policy->cpus); up_write(&policy->rwsem); out_offline_policy: |