Re: [PATCH] uacce: unmap remaining mmapping from user space

[zhangfei]

Hi, Zaibo

On 2020/2/24 äå3:17, Xu Zaibo wrote:
> > Â @@ -585,6 +595,13 @@ void uacce_remove(struct uacce_device *uacce)
> > ÂÂÂÂÂÂÂÂÂ cdev_device_del(uacce->cdev, &uacce->dev);
> > ÂÂÂÂÂ xa_erase(&uacce_xa, uacce->dev_id);
> > ÂÂÂÂÂ put_device(&uacce->dev);
> > +
> > +ÂÂÂ /*
> > +ÂÂÂÂ * unmap remainning mapping from user space, preventing user still
> > +ÂÂÂÂ * access the mmaped area while parent device is already removed
> > +ÂÂÂÂ */
> > +ÂÂÂ if (uacce->inode)
> > +ÂÂÂÂÂÂÂ unmap_mapping_range(uacce->inode->i_mapping, 0, 0, 1);
> Should we unmap them at the first of 'uacce_remove', and before 
> 'uacce_put_queue'?
We can do this,
Though it does not matter, since user space can not interrupt kernel 
function uacce_remove.

Thanks