korg/linux
0
0
Fork 0
mirror of https://mirrors.bfsu.edu.cn/git/linux.git synced 2024-11-15 00:04:15 +08:00
Code Issues Packages Projects Releases Wiki Activity

cpufreq: improve error checking on return values of __cpufreq_governor()

Browse Source 
The __cpufreq_governor() function can fail in rare cases especially
if there are bugs in cpufreq drivers.  Thus we must stop processing
as soon as this routine fails, otherwise it may result in undefined
behavior.

This patch adds error checking code whenever this routine is called
from any place.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Viresh Kumar 2013-08-06 22:53:13 +05:30 committed by Rafael J. Wysocki
parent adc97d6a73
commit 3de9bdeb28
1 changed files with 36 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
drivers/cpufreq/cpufreq.c
View File

@ -874,8 +874,13 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,
int ret = 0, has_target = !!cpufreq_driver->target;
unsigned long flags;
if (has_target)
__cpufreq_governor(policy, CPUFREQ_GOV_STOP);
if (has_target) {
ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
if (ret) {
pr_err("%s: Failed to stop governor\n", __func__);
return ret;
}
}
lock_policy_rwsem_write(policy->cpu);
@ -889,8 +894,11 @@ static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,
unlock_policy_rwsem_write(policy->cpu);
if (has_target) {
__cpufreq_governor(policy, CPUFREQ_GOV_START);
__cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) ||
(ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) {
pr_err("%s: Failed to start governor\n", __func__);
return ret;
}
}
/* Don't touch sysfs links during light-weight init */
@ -1172,7 +1180,7 @@ static int __cpufreq_remove_dev(struct device *dev,
struct subsys_interface *sif, bool frozen)
{
unsigned int cpu = dev->id, cpus;
int new_cpu;
int new_cpu, ret;
unsigned long flags;
struct cpufreq_policy *policy;
struct kobject *kobj;
@ -1196,8 +1204,13 @@ static int __cpufreq_remove_dev(struct device *dev,
return -EINVAL;
}
if (cpufreq_driver->target)
__cpufreq_governor(policy, CPUFREQ_GOV_STOP);
if (cpufreq_driver->target) {
ret = __cpufreq_governor(policy, CPUFREQ_GOV_STOP);
if (ret) {
pr_err("%s: Failed to stop governor\n", __func__);
return ret;
}
}
#ifdef CONFIG_HOTPLUG_CPU
if (!cpufreq_driver->setpolicy)
@ -1231,8 +1244,15 @@ static int __cpufreq_remove_dev(struct device *dev,
/* If cpu is last user of policy, free policy */
if (cpus == 1) {
if (cpufreq_driver->target)
__cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
if (cpufreq_driver->target) {
ret = __cpufreq_governor(policy,
CPUFREQ_GOV_POLICY_EXIT);
if (ret) {
pr_err("%s: Failed to exit governor\n",
__func__);
return ret;
}
}
if (!frozen) {
lock_policy_rwsem_read(cpu);
@ -1263,8 +1283,12 @@ static int __cpufreq_remove_dev(struct device *dev,
cpufreq_policy_free(policy);
} else {
if (cpufreq_driver->target) {
__cpufreq_governor(policy, CPUFREQ_GOV_START);
__cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
if ((ret = __cpufreq_governor(policy, CPUFREQ_GOV_START)) ||
(ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS))) {
pr_err("%s: Failed to start governor\n",
__func__);
return ret;
}
}
}
@ -1912,7 +1936,7 @@ static int __cpufreq_set_policy(struct cpufreq_policy *policy,
/* might be a policy change, too, so fall through */
}
pr_debug("governor: change or update limits\n");
__cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
ret = __cpufreq_governor(policy, CPUFREQ_GOV_LIMITS);
}
error_out: