> IMHO you are right, the same problem may also lead to security
> reason. See the thread of discussions about sound security
> from last week.
> That is real problem only for a small set of character devices which
> have both mmap and release functions pointed by their file_operations.
> I know about sound and about fbmem (fbmem is never used in x86 systems).
> Does it raise new problems in GGI?
You might want to look into defining a vma close op to defer device closing
until the vma goes away. Each vma could hold an open count for the device, and
the device wouldn't go away until the last vma had been closed.
Regards,
Bill