bo block user mapping

[Jerome G. <gl...@fr...>]

Hi,

Got a question about buffer mapping is it possible to block user space
from mapping a buffer that was previously allocated. My use case is
to have user space allocate a buffer put things into it then register
this buffer (with need for user space to first unmap it) through device
specific ioctl and in this ioctl forbid all user space to map this buffer.
Does this sounds possible with current infrastructure (i am looking
through code but i still don't understand it all :)) ?

Side question can then i also block user space from unreference the buffer
as i might also would like to take over buffer management.

Cheers,
Jerome Glisse