From 883d588e556347c4b3221ac492a8acd8a75e730a Mon Sep 17 00:00:00 2001
From: MyungJoo Ham <myungjoo.ham@samsung.com>
Date: Wed, 21 Nov 2012 17:17:11 +0900
Subject: PM / devfreq: remove compiler error when a governor is module

With the intruction of patch, eff607fdb1f787da1fedf46ab6e64adc2afd1c5a,
it became possible to include a governor as a module.
Thus the #ifdef statement for a governor should become #if IS_ENABLED.

Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h
index 235248c..e83ef39 100644
--- a/include/linux/devfreq.h
+++ b/include/linux/devfreq.h
@@ -192,7 +192,7 @@ extern int devfreq_register_opp_notifier(struct device *dev,
 extern int devfreq_unregister_opp_notifier(struct device *dev,
 					   struct devfreq *devfreq);
 
-#ifdef CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND
+#if IS_ENABLED(CONFIG_DEVFREQ_GOV_SIMPLE_ONDEMAND)
 /**
  * struct devfreq_simple_ondemand_data - void *data fed to struct devfreq
  *	and devfreq_add_device
-- 
cgit v0.10.2


From 389baed01edd298c9622c6e28de5e7e250c8767d Mon Sep 17 00:00:00 2001
From: MyungJoo Ham <myungjoo.ham@samsung.com>
Date: Wed, 21 Nov 2012 19:04:51 +0900
Subject: PM / devfreq: missing rcu_read_lock() added for find_device_opp()

opp_get_notifier() uses find_device_opp(), which requires to
held rcu_read_lock. In order to keep the notifier-header
valid, we have added rcu_read_lock().

Reported-by: Kees Cook <keescook@chromium.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 45e053e..1a78ad9 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -1023,11 +1023,18 @@ struct opp *devfreq_recommended_opp(struct device *dev, unsigned long *freq,
  */
 int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
 {
-	struct srcu_notifier_head *nh = opp_get_notifier(dev);
+	struct srcu_notifier_head *nh;
+	int ret = 0;
 
+	rcu_read_lock();
+	nh = opp_get_notifier(dev);
 	if (IS_ERR(nh))
-		return PTR_ERR(nh);
-	return srcu_notifier_chain_register(nh, &devfreq->nb);
+		ret = PTR_ERR(nh);
+	rcu_read_unlock();
+	if (!ret)
+		ret = srcu_notifier_chain_register(nh, &devfreq->nb);
+
+	return ret;
 }
 
 /**
@@ -1042,11 +1049,18 @@ int devfreq_register_opp_notifier(struct device *dev, struct devfreq *devfreq)
  */
 int devfreq_unregister_opp_notifier(struct device *dev, struct devfreq *devfreq)
 {
-	struct srcu_notifier_head *nh = opp_get_notifier(dev);
+	struct srcu_notifier_head *nh;
+	int ret = 0;
 
+	rcu_read_lock();
+	nh = opp_get_notifier(dev);
 	if (IS_ERR(nh))
-		return PTR_ERR(nh);
-	return srcu_notifier_chain_unregister(nh, &devfreq->nb);
+		ret = PTR_ERR(nh);
+	rcu_read_unlock();
+	if (!ret)
+		ret = srcu_notifier_chain_unregister(nh, &devfreq->nb);
+
+	return ret;
 }
 
 MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
-- 
cgit v0.10.2


From b9e1c8e821e7768d5b8629ad7748456af6feece3 Mon Sep 17 00:00:00 2001
From: Sachin Kamat <sachin.kamat@linaro.org>
Date: Wed, 21 Nov 2012 10:36:13 +0530
Subject: PM / devfreq: Fix incorrect argument in error message

'g' is cast to the error return code. Hence gives the following error
which is fixed by this patch.

drivers/devfreq/devfreq.c:645 devfreq_remove_governor() error:
'g' dereferencing possible ERR_PTR()

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 1a78ad9..ac4334f 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -643,7 +643,7 @@ int devfreq_remove_governor(struct devfreq_governor *governor)
 	g = find_devfreq_governor(governor->name);
 	if (IS_ERR(g)) {
 		pr_err("%s: governor %s not registered\n", __func__,
-		       g->name);
+		       governor->name);
 		err = -EINVAL;
 		goto err_out;
 	}
-- 
cgit v0.10.2


From f9c08e2acbbed19ecafc82e4549b7040cc549216 Mon Sep 17 00:00:00 2001
From: Sachin Kamat <sachin.kamat@linaro.org>
Date: Wed, 21 Nov 2012 10:36:14 +0530
Subject: PM / devfreq: Fix return value in devfreq_remove_governor()

Use the value obtained from the function instead of -EINVAL.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index ac4334f..34c00c5 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -644,7 +644,7 @@ int devfreq_remove_governor(struct devfreq_governor *governor)
 	if (IS_ERR(g)) {
 		pr_err("%s: governor %s not registered\n", __func__,
 		       governor->name);
-		err = -EINVAL;
+		err = PTR_ERR(g);
 		goto err_out;
 	}
 	list_for_each_entry(devfreq, &devfreq_list, node) {
-- 
cgit v0.10.2