Re: dvb shared datastructure bug?

[Marcel Siegert <mws@linuxtv.org>]

On Tuesday 13 February 2007, you wrote:
> 
> > attached find a patch that fixes the problem.
> 
> 
> Hi,
> 
> Thank you for the quick response.
> I think there is a small bug in this; at least I don't see where you
> copy over the content of the fops template to the newly allocated piece
> of memory...
> 
> Greetings,
>    Arjan van de Ven

hi arjan,

also fixed that issue. my fault, sorry.

i updated my repository @ linutv.org accordingly.

i will ask mauro to pull changeset   b265e2484422
   dvbdev: fix illegal re-usage of fileoperations struct
from  http://www.linuxtv.org/hg/~mws/v4l-dvb-fixtree

for upstream to kernel., if no more issues appear today.

thanks again.

marcel


diff -r 667e84e2e762 linux/drivers/media/dvb/dvb-core/dvbdev.c
--- a/linux/drivers/media/dvb/dvb-core/dvbdev.c	Tue Feb 13 07:00:55 2007 -0200
+++ b/linux/drivers/media/dvb/dvb-core/dvbdev.c	Tue Feb 13 13:44:47 2007 +0100
@@ -211,12 +211,14 @@ int dvb_register_device(struct dvb_adapt
 			const struct dvb_device *template, void *priv, int type)
 {
 	struct dvb_device *dvbdev;
+	struct file_operations *dvbdevfops;
+
 	int id;
 
 	if (mutex_lock_interruptible(&dvbdev_register_lock))
 		return -ERESTARTSYS;
 
-	if ((id = dvbdev_get_free_id (adap, type)) < 0) {
+	if ((id = dvbdev_get_free_id (adap, type)) < 0){
 		mutex_unlock(&dvbdev_register_lock);
 		*pdvbdev = NULL;
 		printk ("%s: could get find free device id...\n", __FUNCTION__);
@@ -225,7 +227,15 @@ int dvb_register_device(struct dvb_adapt
 
 	*pdvbdev = dvbdev = kmalloc(sizeof(struct dvb_device), GFP_KERNEL);
 
-	if (!dvbdev) {
+	if (!dvbdev){
+		mutex_unlock(&dvbdev_register_lock);
+		return -ENOMEM;
+	}
+
+	dvbdevfops = kzalloc(sizeof(struct file_operations), GFP_KERNEL);
+
+	if (!dvbdevfops){
+		kfree (dvbdev);
 		mutex_unlock(&dvbdev_register_lock);
 		return -ENOMEM;
 	}
@@ -235,7 +245,9 @@ int dvb_register_device(struct dvb_adapt
 	dvbdev->id = id;
 	dvbdev->adapter = adap;
 	dvbdev->priv = priv;
-
+	dvbdev->fops = dvbdevfops;
+
+	memcpy(dvbdev->fops, template->fops, sizeof(struct file_operations));
 	dvbdev->fops->owner = adap->module;
 
 	list_add_tail (&dvbdev->list_head, &adap->device_list);
@@ -263,6 +275,7 @@ void dvb_unregister_device(struct dvb_de
 					dvbdev->type, dvbdev->id)));
 
 	list_del (&dvbdev->list_head);
+	kfree (dvbdev->fops);
 	kfree (dvbdev);
 }
 EXPORT_SYMBOL(dvb_unregister_device);