[PATCH] Implement uhook(call kernel func from userspace) driver

[Greg KH]

On Sat, Jun 23, 2012 at 11:20:35AM +0800, Peiyong Feng wrote:
> Hi all,
> 
> This patch implement the uhook kernel driver. Here are some ideals and
> explanations:
> 
> 1. What is uhook
> 
> uhook(userspace kernel hook) means call kernel function from
> userspace. That is to say, we can
> 
> write a function in kernel space and call it in userspace while the
> kernel Image is running. For example:

That's, um, "interesting", but is of course, nothing we can accept into
the main kernel tree, as I'm sure you can understand.  Otherwise, you
just created a few thousand undocumented system calls whose behavior
changes every release which is not something we can accept.

But it is a great hack, very nicely done.  I'm sure that some people
will like it for debugging, although I'm not quite sure you got all of
the user/kernel boundry conditions correct, and I know the 32/64bit
issues aren't handled, which you might want to clean up sometime in the
future.

greg k-h