Re: [PATCH 2/3] driver: core: add security labels to devtmpfs

["'Greg Kroah-Hartman'" <gregkh@linuxfoundation.org>]

On Fri, Jun 05, 2015 at 08:15:55PM +0900, Namjae Jeon wrote:
> > On Fri, Jun 05, 2015 at 07:10:23PM +0900, Namjae Jeon wrote:
> > > Add support for setting security labels(e.g. smack or selinux labels) to
> > > devtmpfs device nodes. In this manner, drivers can specify desired security
> > > label in their device_type->devnode or class->devnode method.
> > 
> > What driver wants to do this?  And how does it determine the proper
> > security label from within the kernel?  Isn't that something that only
> > userspace can know/set properly?
> Yes, It is possible by userspace, But This api change will help to set uid/gid
> and xattr values easily without need of complex userspace scripts in absence of
> udev like helper.

If you want to do things like this, use a "complex" userspace script
like Android has for their startup (hint, it's just a tiny bash script,
nothing "complex" about it at all...)

> And security label that decided as per each embedded system will be set by
> this api in driver.

Exactly how will that happen?  I don't see any users of it.

greg k-h