How to access kernel memory from user space

[Svetlin Manavski]

Hi all,
I have a very similar problem as described in this thread back in 2009:

http://lists.freebsd.org/pipermail/freebsd-hackers/2009-January/027367.html

I have a kernel module producing networking stats which I need to
frequently read from the user space. A copy of the data structure would be
too expensive so I need to access the kernel data directly from the user
space.

Unfortunately Alexej's code crashes in the following area:

vm_map_lookup(&kmem_map, addr, VM_PROT_ALL, &myentry, &myobject, &mypindex,
&myprot, &mywired); /* OUT */
vm_map_lookup_done(kmem_map, myentry);
I am using 64bit FreeBSD 8.2 on Intel Xeon hardware.
Any idea how to make a stable implementation on my platform?

Thank you,
Svetlin