2009-07-30 21:49:56

by Jiri Slaby

Subject: [PATCH repost2 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(-)

diff --git a/drivers/media/video/hdpvr/hdpvr-core.c b/drivers/media/video/hdpvr/hdpvr-core.c
index 188bd5a..1c9bc94 100644
--- a/drivers/media/video/hdpvr/hdpvr-core.c
+++ b/drivers/media/video/hdpvr/hdpvr-core.c
@@ -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);
}
diff --git a/drivers/media/video/hdpvr/hdpvr-video.c 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
@@ -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)) {
--
1.6.3.3

2009-07-30 21:49:54

by Jiri Slaby

Subject: [PATCH repost2 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(-)

diff --git a/drivers/media/video/saa7134/saa7134-video.c b/drivers/media/video/saa7134/saa7134-video.c
index 58854df..da26f47 100644
--- a/drivers/media/video/saa7134/saa7134-video.c
+++ b/drivers/media/video/saa7134/saa7134-video.c
@@ -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;
}

--
1.6.3.3

2009-07-30 23:47:19

by Douglas Schilling Landgraf

Subject: Re: [PATCH repost2 1/2] V4L: hdpvr, fix lock imbalances

Hello Jiri,

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

> 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(-)
>
> diff --git a/drivers/media/video/hdpvr/hdpvr-core.c
> b/drivers/media/video/hdpvr/hdpvr-core.c index 188bd5a..1c9bc94 100644
> --- a/drivers/media/video/hdpvr/hdpvr-core.c
> +++ b/drivers/media/video/hdpvr/hdpvr-core.c
> @@ -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);
> }
> diff --git a/drivers/media/video/hdpvr/hdpvr-video.c
> 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
> @@ -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)) {