[PATCH 58/70] cpufreq: interactive: fix NULL pointer dereference at sysfs ops

From: BÃlint Czobor
Date: Tue Oct 27 2015 - 13:38:44 EST


From: Minsung Kim <ms925.kim@xxxxxxxxxxx>

sysfs ops for target_loads and above_hispeed_delay can be called before
initializing tunables at CPUFREQ_GOV_POLICY_INIT. Create sysfs entries after
initialization.

Change-Id: I50356198d7629731c0d32a3066d61fe8354e0001
Signed-off-by: Minsung Kim <ms925.kim@xxxxxxxxxxx>
Signed-off-by: BÃlint Czobor <czoborbalint@xxxxxxxxx>
---
drivers/cpufreq/cpufreq_interactive.c | 25 ++++++++++++++-----------
1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/cpufreq/cpufreq_interactive.c b/drivers/cpufreq/cpufreq_interactive.c
index 9f63bd1..8297ac6 100644
--- a/drivers/cpufreq/cpufreq_interactive.c
+++ b/drivers/cpufreq/cpufreq_interactive.c
@@ -1178,13 +1178,6 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
return -ENOMEM;
}

- rc = sysfs_create_group(get_governor_parent_kobj(policy),
- get_sysfs_attr());
- if (rc) {
- kfree(tunables);
- return rc;
- }
-
tunables->usage_count = 1;
tunables->above_hispeed_delay = default_above_hispeed_delay;
tunables->nabove_hispeed_delay =
@@ -1200,16 +1193,26 @@ static int cpufreq_governor_interactive(struct cpufreq_policy *policy,
spin_lock_init(&tunables->target_loads_lock);
spin_lock_init(&tunables->above_hispeed_delay_lock);

+ policy->governor_data = tunables;
+ if (!have_governor_per_policy())
+ common_tunables = tunables;
+
+ rc = sysfs_create_group(get_governor_parent_kobj(policy),
+ get_sysfs_attr());
+ if (rc) {
+ kfree(tunables);
+ policy->governor_data = NULL;
+ if (!have_governor_per_policy())
+ common_tunables = NULL;
+ return rc;
+ }
+
if (!policy->governor->initialized) {
idle_notifier_register(&cpufreq_interactive_idle_nb);
cpufreq_register_notifier(&cpufreq_notifier_block,
CPUFREQ_TRANSITION_NOTIFIER);
}

- policy->governor_data = tunables;
- if (!have_governor_per_policy())
- common_tunables = tunables;
-
break;

case CPUFREQ_GOV_POLICY_EXIT:
--
1.7.9.5

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