Re: [PATCH 2/2] devfreq: separate error paths from successful path

Re: [PATCH 2/2] devfreq: separate error paths from successful path

[MyungJoo Ham]

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Sender : Axel Lin<axel.lin@gmail.com> Date : 2011-11-10 16:30 (GMT+09:00)
> I think this change improves readability.
> 
> Signed-off-by: Axel Lin 

I agree. It makes it easier to read.

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

> ---
> drivers/devfreq/devfreq.c |   15 +++++++--------
> 1 files changed, 7 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> index 59d24e9..c189b82 100644
> --- a/drivers/devfreq/devfreq.c
> +++ b/drivers/devfreq/devfreq.c
> @@ -347,7 +347,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
> if (!IS_ERR(devfreq)) {
> dev_err(dev, "%s: Unable to create devfreq for the device. It already has one. ", __func__);
> err = -EINVAL;
> - goto out;
> + goto err_out;
> }
> }
> 
> @@ -356,7 +356,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
> dev_err(dev, "%s: Unable to create devfreq for the device ",
> __func__);
> err = -ENOMEM;
> - goto out;
> + goto err_out;
> }
> 
> mutex_init(&devfreq->lock);
> @@ -399,17 +399,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
>    devfreq->next_polling);
> }
> mutex_unlock(&devfreq_list_lock);
> - goto out;
> +out:
> + return devfreq;
> +
> err_init:
> device_unregister(&devfreq->dev);
> err_dev:
> mutex_unlock(&devfreq->lock);
> kfree(devfreq);
> -out:
> - if (err)
> - return ERR_PTR(err);
> - else
> - return devfreq;
> +err_out:
> + return ERR_PTR(err);
> }
> 
> /**
> -- 
> 1.7.5.4
> 
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Re: [PATCH 2/2] devfreq: separate error paths from successful path

[Rafael J. Wysocki]

On Friday, November 11, 2011, MyungJoo Ham wrote:
> Sender : Axel Lin<axel.lin@gmail.com> Date : 2011-11-10 16:30 (GMT+09:00)
> > I think this change improves readability.
> > 
> > Signed-off-by: Axel Lin 
> 
> I agree. It makes it easier to read.
> 
> Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>

Applied to linux-pm/pm-fixes.

Thanks,
Rafael


> > ---
> > drivers/devfreq/devfreq.c |   15 +++++++--------
> > 1 files changed, 7 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> > index 59d24e9..c189b82 100644
> > --- a/drivers/devfreq/devfreq.c
> > +++ b/drivers/devfreq/devfreq.c
> > @@ -347,7 +347,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
> > if (!IS_ERR(devfreq)) {
> > dev_err(dev, "%s: Unable to create devfreq for the device. It already has one. ", __func__);
> > err = -EINVAL;
> > - goto out;
> > + goto err_out;
> > }
> > }
> > 
> > @@ -356,7 +356,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
> > dev_err(dev, "%s: Unable to create devfreq for the device ",
> > __func__);
> > err = -ENOMEM;
> > - goto out;
> > + goto err_out;
> > }
> > 
> > mutex_init(&devfreq->lock);
> > @@ -399,17 +399,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
> >    devfreq->next_polling);
> > }
> > mutex_unlock(&devfreq_list_lock);
> > - goto out;
> > +out:
> > + return devfreq;
> > +
> > err_init:
> > device_unregister(&devfreq->dev);
> > err_dev:
> > mutex_unlock(&devfreq->lock);
> > kfree(devfreq);
> > -out:
> > - if (err)
> > - return ERR_PTR(err);
> > - else
> > - return devfreq;
> > +err_out:
> > + return ERR_PTR(err);
> > }
> > 
> > /**
> 

Re: [PATCH 2/2] devfreq: separate error paths from successful path

[Rafael J. Wysocki]

On Tuesday, November 15, 2011, Rafael J. Wysocki wrote:
> On Friday, November 11, 2011, MyungJoo Ham wrote:
> > Sender : Axel Lin<axel.lin@gmail.com> Date : 2011-11-10 16:30 (GMT+09:00)
> > > I think this change improves readability.
> > > 
> > > Signed-off-by: Axel Lin 
> > 
> > I agree. It makes it easier to read.
> > 
> > Acked-by: MyungJoo Ham <myungjoo.ham@samsung.com>
> 
> Applied to linux-pm/pm-fixes.

Sorry, this one went to linux-pm/linux-next and will wait for the 3.3 merge
window.

Thanks,
Rafael


> > > ---
> > > drivers/devfreq/devfreq.c |   15 +++++++--------
> > > 1 files changed, 7 insertions(+), 8 deletions(-)
> > > 
> > > diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
> > > index 59d24e9..c189b82 100644
> > > --- a/drivers/devfreq/devfreq.c
> > > +++ b/drivers/devfreq/devfreq.c
> > > @@ -347,7 +347,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
> > > if (!IS_ERR(devfreq)) {
> > > dev_err(dev, "%s: Unable to create devfreq for the device. It already has one. ", __func__);
> > > err = -EINVAL;
> > > - goto out;
> > > + goto err_out;
> > > }
> > > }
> > > 
> > > @@ -356,7 +356,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
> > > dev_err(dev, "%s: Unable to create devfreq for the device ",
> > > __func__);
> > > err = -ENOMEM;
> > > - goto out;
> > > + goto err_out;
> > > }
> > > 
> > > mutex_init(&devfreq->lock);
> > > @@ -399,17 +399,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
> > >    devfreq->next_polling);
> > > }
> > > mutex_unlock(&devfreq_list_lock);
> > > - goto out;
> > > +out:
> > > + return devfreq;
> > > +
> > > err_init:
> > > device_unregister(&devfreq->dev);
> > > err_dev:
> > > mutex_unlock(&devfreq->lock);
> > > kfree(devfreq);
> > > -out:
> > > - if (err)
> > > - return ERR_PTR(err);
> > > - else
> > > - return devfreq;
> > > +err_out:
> > > + return ERR_PTR(err);
> > > }
> > > 
> > > /**
> > 
> 
> --
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> 

[PATCH 1/2] devfreq: fix use after free in devfreq_remove_device

[Axel Lin]

In devfreq_remove_device, calling _remove_devfreq will also free devfreq.
Don't dereference devfreq->governor->no_central_polling after _remove_devfreq.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/devfreq/devfreq.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index d065925..59d24e9 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -418,10 +418,14 @@ out:
  */
 int devfreq_remove_device(struct devfreq *devfreq)
 {
+	bool central_polling;
+
 	if (!devfreq)
 		return -EINVAL;
 
-	if (!devfreq->governor->no_central_polling) {
+	central_polling = !devfreq->governor->no_central_polling;
+
+	if (central_polling) {
 		mutex_lock(&devfreq_list_lock);
 		while (wait_remove_device == devfreq) {
 			mutex_unlock(&devfreq_list_lock);
@@ -433,7 +437,7 @@ int devfreq_remove_device(struct devfreq *devfreq)
 	mutex_lock(&devfreq->lock);
 	_remove_devfreq(devfreq, false); /* it unlocks devfreq->lock */
 
-	if (!devfreq->governor->no_central_polling)
+	if (central_polling)
 		mutex_unlock(&devfreq_list_lock);
 
 	return 0;
-- 
1.7.5.4

[PATCH 2/2] devfreq: separate error paths from successful path

[Axel Lin]

I think this change improves readability.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
---
 drivers/devfreq/devfreq.c |   15 +++++++--------
 1 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c
index 59d24e9..c189b82 100644
--- a/drivers/devfreq/devfreq.c
+++ b/drivers/devfreq/devfreq.c
@@ -347,7 +347,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 		if (!IS_ERR(devfreq)) {
 			dev_err(dev, "%s: Unable to create devfreq for the device. It already has one.\n", __func__);
 			err = -EINVAL;
-			goto out;
+			goto err_out;
 		}
 	}
 
@@ -356,7 +356,7 @@ struct devfreq *devfreq_add_device(struct device *dev,
 		dev_err(dev, "%s: Unable to create devfreq for the device\n",
 			__func__);
 		err = -ENOMEM;
-		goto out;
+		goto err_out;
 	}
 
 	mutex_init(&devfreq->lock);
@@ -399,17 +399,16 @@ struct devfreq *devfreq_add_device(struct device *dev,
 				   devfreq->next_polling);
 	}
 	mutex_unlock(&devfreq_list_lock);
-	goto out;
+out:
+	return devfreq;
+
 err_init:
 	device_unregister(&devfreq->dev);
 err_dev:
 	mutex_unlock(&devfreq->lock);
 	kfree(devfreq);
-out:
-	if (err)
-		return ERR_PTR(err);
-	else
-		return devfreq;
+err_out:
+	return ERR_PTR(err);
 }
 
 /**
-- 
1.7.5.4