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    SubjectRe: 32 bit (socket layer) ioctl emulation for 64 bit kernels- Question regarding...
    Thanks Arnd
    If I have understood correctly the following would be the changes I
    would have to make in the kernel...Please correct me if I am wrong.

    It seems to me step (d) would be as you say a little tricky but I
    could attempt it
    depending on the amount of time I have in the project I am on at the moment.
    Proposed modifications...
    a) Struct file_operations(include/linux/fs.h) has a compat_ioctl hook for file
    ioctls. Include a compat_proto_ioctl hook in proto_ops(include/net.h) for
    modular socket ioctls.

    b) socket.c has a 'file_operations' type struct socket_file_ops where the
    .compat_ioctl member is currently not used. Define compat_sock_ioctl in
    socket.c and assign to .compat_ioctl member of socket_file_ops
    This is ifdef'd with CONFIG_COMPAT

    c) compat_sock_ioctl will by default call the protocol's ioctl
    currently supporting the socket interface when handling modular socket ioctls,
    like so. socket->ops->compat_proto_ioctl(...)
    which in this case is x25_compat_ioctl.

    d)If compat_sock_ioctl has to perform a function similar to
    where in SIOC* commands are handled, then introduce a newly defined
    compat_dev_ioctl that would have stuff like dev_ifsioc that would have
    been removed from fs/compat_ioctl.c.
    Then the protocol's ioctl (called by default in the step c above) would itself
    default to compat_dev_ioctl ensuring other socket layer
    ioctls are handled by the device layer function, compat_dev_ioctl


    On 10/10/05, Arnd Bergmann <> wrote:
    > On Maandag 10 Oktober 2005 06:21, spereira wrote:
    > >
    > > Is there currently an alternative to register_ioctl32_conversion that
    > > would help achive 32 bit ioctl emulation at the socket layer?
    > > Any suggestions/advice whould be much appreciated.
    > The correct solution would be to add the missing functionality to
    > net/socket.c and move over the implementation of SIOC* from
    > fs/compat_ioctl.c. Getting the code path right is a little tricky,
    > but I think a patch to fix this up would be appreciated.
    > As a start, you could define a compat_sock_ioctl along the
    > lines of compat_blkdev_ioctl and add your own handlers to the
    > x25_proto_ops, but IMHO it would makes sense to get rid of stuff
    > like dev_ifsioc from fs/compat_ioctl.c at the same time by
    > introducing a new compat_dev_ioctl called from compat_sock_ioctl.
    > Arnd <><
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      Last update: 2005-10-11 09:12    [W:0.021 / U:50.828 seconds]
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