get_device in device_create_file

From: Pete Zaitcev
Date: Tue Aug 01 2006 - 16:23:23 EST

Hi, Greg:

This code makes no sense to me:

> int device_create_file(struct device * dev, struct device_attribute * attr)
> {
> int error = 0;
> if (get_device(dev)) {
> error = sysfs_create_file(&dev->kobj, &attr->attr);
> put_device(dev);
> }
> return error;
> }

If the struct device *dev, and its presumably enclosing structure,
can be freed by a different CPU (or pre-empt), then get_device
does not protect it. It can be freed before get_device is reached.
Buf it not, and the caller has a reference, then the call to
get_device is redundant.

How is this supposed to work?

-- Pete
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