From mboxrd@z Thu Jan 1 00:00:00 1970 From: spereira Subject: Re: 32 bit (socket layer) ioctl emulation for 64 bit kernels- Question regarding... Date: Tue, 11 Oct 2005 17:09:07 +1000 Message-ID: <3ad486780510110009s2de65e68vf19e283edf997e89@mail.gmail.com> References: <3ad486780510092121h78a522cat11f33581dfc670dc@mail.gmail.com> <200510101348.49598.arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Return-path: To: Arnd Bergmann In-Reply-To: <200510101348.49598.arnd@arndb.de> Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 sock_ioctl(socket.c) where in SIOC* commands are handled, then introduce a newly defined compat_dev_ioctl that would have stuff like dev_ifsioc that would have previously 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 regards, Shaun 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 <>< >