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authorJean-Francois Moine <moinejf@free.fr>2008-11-18 15:52:31 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2008-11-24 12:01:23 -0200
commit5c4fa002b1c7b40f65fa911ae17a823ec9e26ab2 (patch)
treede334f5d2dcdb93fff14584957ed820f9fe57208
parent98522a7be97f2b23451342e36c39f412f0461e24 (diff)
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V4L/DVB (9690): gspca: Lock the subdrivers via module_get/put.
The previous subdriver protection against rmmod was done via the file operations table in the device descriptor. On device disconnection while streaming, the device structure was freed at close time, and the module_put still used the module name in the freed area. Now, explicit module get/put are done on open and close. Signed-off-by: Jean-Francois Moine <moinejf@free.fr> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
-rw-r--r--drivers/media/video/gspca/gspca.c13
-rw-r--r--drivers/media/video/gspca/gspca.h2
2 files changed, 11 insertions, 4 deletions
diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index f28d2f4..a565f37 100644
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -874,6 +874,13 @@ static int dev_open(struct inode *inode, struct file *file)
ret = -EBUSY;
goto out;
}
+
+ /* protect the subdriver against rmmod */
+ if (!try_module_get(gspca_dev->module)) {
+ ret = -ENODEV;
+ goto out;
+ }
+
gspca_dev->users++;
/* one more user */
@@ -920,6 +927,7 @@ static int dev_close(struct inode *inode, struct file *file)
gspca_dev->memory = GSPCA_MEMORY_NO;
}
file->private_data = NULL;
+ module_put(gspca_dev->module);
mutex_unlock(&gspca_dev->queue_lock);
PDEBUG(D_STREAM, "close done");
@@ -1870,9 +1878,8 @@ int gspca_dev_probe(struct usb_interface *intf,
/* init video stuff */
memcpy(&gspca_dev->vdev, &gspca_template, sizeof gspca_template);
gspca_dev->vdev.parent = &dev->dev;
- memcpy(&gspca_dev->fops, &dev_fops, sizeof gspca_dev->fops);
- gspca_dev->vdev.fops = &gspca_dev->fops;
- gspca_dev->fops.owner = module; /* module protection */
+ gspca_dev->vdev.fops = &dev_fops;
+ gspca_dev->module = module;
gspca_dev->present = 1;
ret = video_register_device(&gspca_dev->vdev,
VFL_TYPE_GRABBER,
diff --git a/drivers/media/video/gspca/gspca.h b/drivers/media/video/gspca/gspca.h
index c35d7b9..2ae1ad7 100644
--- a/drivers/media/video/gspca/gspca.h
+++ b/drivers/media/video/gspca/gspca.h
@@ -121,7 +121,7 @@ struct gspca_frame {
struct gspca_dev {
struct video_device vdev; /* !! must be the first item */
- struct file_operations fops;
+ struct module *module; /* subdriver handling the device */
struct usb_device *dev;
struct kref kref;
struct file *capt_file; /* file doing video capture */