openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

[media] gspca_main: Locking fixes 1 

The gspca_dev->streaming boolean is protected against multiple access
through gspca_dev->queue_lock everywhere except for 2 places. This patch
fixes this by bringing it under the lock in vidioc_streamoff. And by
removing the check for gspca_dev->streaming in gspca_disconnect,
the destroy_urbs call may be called multiple times (and is protected
by the usb_lock) and calling wake_up_interruptible can also always be done
safely.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Hans de Goede 2010-12-30 13:11:21 -03:00 committed by Mauro Carvalho Chehab
parent 82f4b5b67e
commit 4e770f7602
1 changed files with 10 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
drivers/media/video/gspca/gspca.c
View File

@ -1630,11 +1630,15 @@ static int vidioc_streamoff(struct file *file, void *priv,
if (buf_type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
return -EINVAL;
if (!gspca_dev->streaming)
return 0;
if (mutex_lock_interruptible(&gspca_dev->queue_lock))
return -ERESTARTSYS;
if (!gspca_dev->streaming) {
ret = 0;
goto out;
}
/* check the capture file */
if (gspca_dev->capt_file != file) {
ret = -EBUSY;
@ -2341,12 +2345,11 @@ void gspca_disconnect(struct usb_interface *intf)
PDEBUG(D_PROBE, "%s disconnect",
video_device_node_name(&gspca_dev->vdev));
mutex_lock(&gspca_dev->usb_lock);
gspca_dev->present = 0;
if (gspca_dev->streaming) {
destroy_urbs(gspca_dev);
wake_up_interruptible(&gspca_dev->wq);
}
gspca_dev->present = 0;
wake_up_interruptible(&gspca_dev->wq);
destroy_urbs(gspca_dev);
#if defined(CONFIG_INPUT) || defined(CONFIG_INPUT_MODULE)
gspca_input_destroy_urb(gspca_dev);