Re: [linux-usb-devel] Bug creating USB endpoints in 2.6.20.x (kernel bug 8198)

[Tejun Heo <htejun@gmail.com>]

Dmitry Torokhov wrote:
>> As written above, I think it's better to risk module unload / sysfs race
>> than keeping the current sysfs deletion / open race.  What do you guys
>> think?
>>
> 
> How about embedding struct attribute fro devt into struct
> [class_]device for now? It is not too big and device is still going to
> be pinned into memory while there are sysfs users... I don't like
> fattening of device structures but leaks and/or oopses are worse in my
> book.

Right, your book is apparently much better than mine.  Actually, we can
just free devt_attr in device_release().  Looking at the code, class
device is already doing it that way, so here's the full-assed fix.
Chris, can you please test the attached patch?

Thanks.

-- 
tejun

---
 drivers/base/core.c |    7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Index: tree0/drivers/base/core.c
===================================================================
--- tree0.orig/drivers/base/core.c
+++ tree0/drivers/base/core.c
@@ -93,6 +93,9 @@ static void device_release(struct kobjec
 {
 	struct device * dev = to_dev(kobj);
 
+	kfree(dev->devt_attr);
+	dev->devt_attr = NULL;
+
 	if (dev->release)
 		dev->release(dev);
 	else if (dev->class && dev->class->dev_release)
@@ -650,10 +653,8 @@ void device_del(struct device * dev)
 
 	if (parent)
 		klist_del(&dev->knode_parent);
-	if (dev->devt_attr) {
+	if (dev->devt_attr)
 		device_remove_file(dev, dev->devt_attr);
-		kfree(dev->devt_attr);
-	}
 	if (dev->class) {
 		sysfs_remove_link(&dev->kobj, "subsystem");
 		/* If this is not a "fake" compatible device, remove the