ioctl() and sysctl()

[Matthew Dillon]

:I'm at the point where I have to touch ioctl() and sysctl() to finish
:my work on stackgap removal from the linux emulator and separation of
:COMPAT_43 from the main tree.
:
:The ioctl() syscall is emulated by in the linuxolator and involves a
:stackgap allocation when servicing the LINUX_CDROMSUBCHNL ioctl().
:In order to remedy the problem, I have to get rid of deep
:copyin()/copyout()'s.  For example, the smb device has the following
:ioctl() cmd structure:
:

    It may not be possible to remove the deep copyin and copyout ops 
    from ioctl but it ought to be possible to augment the interface to
    supply an optional callback function that the emulation code can
    supply.

    e.g. so keep the copyin's and copyout's pretty much as they are and
    call them if the callback function is NULL.  If the callback function is
    not NULL call the ioctl code would call the callback function instead.

    This way we only have to mess around with ioctl's related to linux emulated
    calls in order to get rid of the linux emulation's stackgap.

						-Matt