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V4L: hdpvr, fix lock imbalances

PATCH In review Jiri Slaby 2 participants 3 messages Jul 30, 2009 Media (V4L/DVB)

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Jiri Slaby

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#0 lore raw

PATCH 1/2 V4L: hdpvr, fix lock imbalances

Hrm, nobody picked these up, twice. Maybe this time :)? --

There are many lock imbalances in this driver. Fix all found.

Signed-off-by Jiri Slaby <[email protected]>
---
 drivers/media/video/hdpvr/hdpvr-core.c  |   12 ++++++------
 drivers/media/video/hdpvr/hdpvr-video.c |    6 ++++--
 2 files changed, 10 insertions(+), 8 deletions(-)
drivers/media/video/hdpvr/hdpvr-core.c +6 -6
index 188bd5a..1c9bc94 100644
@@ -126,7 +126,7 @@ static int device_authorization(struct hdpvr_device *dev)
 	char *print_buf = kzalloc(5*buf_size+1, GFP_KERNEL);
 	if (!print_buf) {
 		v4l2_err(&dev->v4l2_dev, "Out of memory\n");
-		goto error;
+		return retval;
 	}
 #endif
 

@@ -140,7 +140,7 @@ static int device_authorization(struct hdpvr_device *dev)
 	if (ret != 46) {
 		v4l2_err(&dev->v4l2_dev,
 			 "unexpected answer of status request, len %d\n", ret);
-		goto error;
+		goto unlock;
 	}
 #ifdef HDPVR_DEBUG
 	else {

@@ -163,7 +163,7 @@ static int device_authorization(struct hdpvr_device *dev)
 		v4l2_err(&dev->v4l2_dev, "unknown firmware version 0x%x\n",
 			dev->usbc_buf[1]);
 		ret = -EINVAL;
-		goto error;
+		goto unlock;
 	}
 
 	response = dev->usbc_buf+38;

@@ -188,10 +188,10 @@ static int device_authorization(struct hdpvr_device *dev)
 			      10000);
 	v4l2_dbg(MSG_INFO, hdpvr_debug, &dev->v4l2_dev,
 		 "magic request returned %d\n", ret);
-	mutex_unlock(&dev->usbc_mutex);
 
 	retval = ret != 8;
-error:
+unlock:
+	mutex_unlock(&dev->usbc_mutex);
 	return retval;
 }
 

@@ -350,6 +350,7 @@ static int hdpvr_probe(struct usb_interface *interface,
 
 	mutex_lock(&dev->io_mutex);
 	if (hdpvr_alloc_buffers(dev, NUM_BUFFERS)) {
+		mutex_unlock(&dev->io_mutex);
 		v4l2_err(&dev->v4l2_dev,
 			 "allocating transfer buffers failed\n");
 		goto error;

@@ -381,7 +382,6 @@ static int hdpvr_probe(struct usb_interface *interface,
 
 error:
 	if (dev) {
-		mutex_unlock(&dev->io_mutex);
 		/* this frees allocated memory */
 		hdpvr_delete(dev);
 	}
drivers/media/video/hdpvr/hdpvr-video.c +4 -2
index ccd47f5..5937de2 100644
@@ -375,6 +375,7 @@ static int hdpvr_open(struct file *file)
 	 * in resumption */
 	mutex_lock(&dev->io_mutex);
 	dev->open_count++;
+	mutex_unlock(&dev->io_mutex);
 
 	fh->dev = dev;
 

@@ -383,7 +384,6 @@ static int hdpvr_open(struct file *file)
 
 	retval = 0;
 err:
-	mutex_unlock(&dev->io_mutex);
 	return retval;
 }
 

@@ -519,8 +519,10 @@ static unsigned int hdpvr_poll(struct file *filp, poll_table *wait)
 
 	mutex_lock(&dev->io_mutex);
 
-	if (video_is_unregistered(dev->video_dev))
+	if (video_is_unregistered(dev->video_dev)) {
+		mutex_unlock(&dev->io_mutex);
 		return -EIO;
+	}
 
 	if (dev->status == STATUS_IDLE) {
 		if (hdpvr_start_streaming(dev)) {
Signature · 1 line
1.6.3.3
author
#1 lore raw

PATCH 2/2 V4L: saa7134, fix lock imbalance

There is one superfluos (imbalanced) unlock in a poll function. Remove it.

Signed-off-by Jiri Slaby <[email protected]>
---
 drivers/media/video/saa7134/saa7134-video.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
drivers/media/video/saa7134/saa7134-video.c +0 -1
index 58854df..da26f47 100644
@@ -1444,7 +1444,6 @@ video_poll(struct file *file, struct poll_table_struct *wait)
 			fh->cap.ops->buf_queue(&fh->cap,fh->cap.read_buf);
 			fh->cap.read_off = 0;
 		}
-		mutex_unlock(&fh->cap.vb_lock);
 		buf = fh->cap.read_buf;
 	}
Signature · 1 line
1.6.3.3
#2 lore raw
In reply to Jiri Slaby

Hello Jiri,

Quoted 2 lines · On Thu, 30 Jul 2009 23:49:48 +0200 Jiri Slaby <[email protected]> wrote:

Hrm, nobody picked these up, twice. Maybe this time :)? --

Thanks for this email. Both patches are applied to devel tree.

Cheers,
Douglas

Quoted 101 lines

There are many lock imbalances in this driver. Fix all found.

Signed-off-by Jiri Slaby <[email protected]>
---
 drivers/media/video/hdpvr/hdpvr-core.c  |   12 ++++++------
 drivers/media/video/hdpvr/hdpvr-video.c |    6 ++++--
 2 files changed, 10 insertions(+), 8 deletions(-)
(quoted diff) +0 -0

b/drivers/media/video/hdpvr/hdpvr-core.c index 188bd5a..1c9bc94 100644

drivers/media/video/hdpvr/hdpvr-core.c +2 -2
@@ -126,7 +126,7 @@ static int device_authorization(struct
 hdpvr_device *dev) char *print_buf = kzalloc(5*buf_size+1,
 GFP_KERNEL); if (!print_buf) {
 		v4l2_err(&dev->v4l2_dev, "Out of memory\n");
-		goto error;
+		return retval;
 	}
 #endif
 

@@ -140,7 +140,7 @@ static int device_authorization(struct
 hdpvr_device *dev) if (ret != 46) {
 		v4l2_err(&dev->v4l2_dev,
 			 "unexpected answer of status request, len
 %d\n", ret);
-		goto error;
+		goto unlock;
 	}
 #ifdef HDPVR_DEBUG
drivers/media/video/hdpvr/hdpvr-core.c +0 -0
 	else {

@@ -163,7 +163,7 @@ static int device_authorization(struct

hdpvr_device *dev) v4l2_err(&dev->v4l2_dev, "unknown firmware version 0x%x\n", dev->usbc_buf[1]);

drivers/media/video/hdpvr/hdpvr-core.c +4 -4
 		ret = -EINVAL;
-		goto error;
+		goto unlock;
 	}
 
 	response = dev->usbc_buf+38;

@@ -188,10 +188,10 @@ static int device_authorization(struct
 hdpvr_device *dev) 10000);
 	v4l2_dbg(MSG_INFO, hdpvr_debug, &dev->v4l2_dev,
 		 "magic request returned %d\n", ret);
-	mutex_unlock(&dev->usbc_mutex);
 
 	retval = ret != 8;
-error:
+unlock:
+	mutex_unlock(&dev->usbc_mutex);
 	return retval;
 }
 

@@ -350,6 +350,7 @@ static int hdpvr_probe(struct usb_interface
 *interface, 
 	mutex_lock(&dev->io_mutex);
 	if (hdpvr_alloc_buffers(dev, NUM_BUFFERS)) {
+		mutex_unlock(&dev->io_mutex);
 		v4l2_err(&dev->v4l2_dev,
 			 "allocating transfer buffers failed\n");
 		goto error;

@@ -381,7 +382,6 @@ static int hdpvr_probe(struct usb_interface
 *interface, 
 error:
 	if (dev) {
-		mutex_unlock(&dev->io_mutex);
 		/* this frees allocated memory */
 		hdpvr_delete(dev);
 	}
(quoted diff) +0 -0

b/drivers/media/video/hdpvr/hdpvr-video.c index ccd47f5..5937de2 100644 --- a/drivers/media/video/hdpvr/hdpvr-video.c +++ b/drivers/media/video/hdpvr/hdpvr-video.c

drivers/media/video/hdpvr/hdpvr-video.c +4 -2
@@ -375,6 +375,7 @@ static int hdpvr_open(struct file *file)
 	 * in resumption */
 	mutex_lock(&dev->io_mutex);
 	dev->open_count++;
+	mutex_unlock(&dev->io_mutex);
 
 	fh->dev = dev;
 

@@ -383,7 +384,6 @@ static int hdpvr_open(struct file *file)
 
 	retval = 0;
 err:
-	mutex_unlock(&dev->io_mutex);
 	return retval;
 }
 

@@ -519,8 +519,10 @@ static unsigned int hdpvr_poll(struct file
 *filp, poll_table *wait) 
 	mutex_lock(&dev->io_mutex);
 
-	if (video_is_unregistered(dev->video_dev))
+	if (video_is_unregistered(dev->video_dev)) {
+		mutex_unlock(&dev->io_mutex);
 		return -EIO;
+	}
 
 	if (dev->status == STATUS_IDLE) {
 		if (hdpvr_start_streaming(dev)) {