[PATCH 2/2] cpufreq: Properly handle errors from cpufreq_init_policy()

From: Viresh Kumar
Date: Wed Jul 08 2015 - 05:42:50 EST


cpufreq_init_policy() can fail, and we don't do anything except a call
to ->exit() on that. The policy should be freed if this happens.

Lets do it properly.

Reported-by: "Jon Medhurst (Tixy)" <tixy@xxxxxxxxxx>
Signed-off-by: Viresh Kumar <viresh.kumar@xxxxxxxxxx>
---
drivers/cpufreq/cpufreq.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index b7aac8eec525..006299214d2e 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1051,11 +1051,10 @@ static int cpufreq_add_dev_interface(struct cpufreq_policy *policy,
return cpufreq_add_dev_symlink(policy);
}

-static void cpufreq_init_policy(struct cpufreq_policy *policy)
+static int cpufreq_init_policy(struct cpufreq_policy *policy)
{
struct cpufreq_governor *gov = NULL;
struct cpufreq_policy new_policy;
- int ret = 0;

memcpy(&new_policy, policy, sizeof(*policy));

@@ -1074,12 +1073,7 @@ static void cpufreq_init_policy(struct cpufreq_policy *policy)
cpufreq_parse_governor(gov->name, &new_policy.policy, NULL);

/* set default policy */
- ret = cpufreq_set_policy(policy, &new_policy);
- if (ret) {
- pr_debug("setting policy failed\n");
- if (cpufreq_driver->exit)
- cpufreq_driver->exit(policy);
- }
+ return cpufreq_set_policy(policy, &new_policy);
}

static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy,
@@ -1376,7 +1370,12 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)
write_unlock_irqrestore(&cpufreq_driver_lock, flags);
}

- cpufreq_init_policy(policy);
+ ret = cpufreq_init_policy(policy);
+ if (ret) {
+ pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n",
+ __func__, cpu, ret);
+ goto out_remove_policy_notify;
+ }

if (!recover_policy) {
policy->user_policy.policy = policy->policy;
@@ -1396,6 +1395,9 @@ static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif)

return 0;

+out_remove_policy_notify:
+ /* cpufreq_policy_free() will notify based on this */
+ recover_policy = true;
out_exit_policy:
up_write(&policy->rwsem);

--
2.4.0

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