Re: Compiling C++ kernel module + Makefile

[Giuliano Pochini <pochini@denise.shiny.it>]

On Mon, 19 Jan 2004, Bart Samwel wrote:

> But we're not talking about the base kernel here. We're not talking
> about migrating the kernel to C++, or even modules that are part of the
> Linux kernel source. We're talking about *independent modules*. The
> kernel exports a module interface, and any binary driver that correctly
> hooks into the interface of the running kernel (using the correct
> calling conventions of the running kernel) and behaves properly (e.g.,
> doesn't do stack unwinds over chunks of kernel functions etc.) can hook
> into it and do useful work. If somebody has decided that it would be
> worth it for his project to use C++ (without exceptions, rtti and the
> whole shebang) then so be it, why should you care? It's just binary code
> that hooks into the module interface, using the correct calling
> conventions. It doesn't do dirty stuff -- no exceptions, no RTTI,
> etcetera. It compiles into plain, module-interface conforming assembler,
> that can be compiled with -- you guessed it -- 'as', the AT&T syntax
> assembler. Yes, they're taking a risk. Their risk is that C++ can't
> import the kernel headers, or that C++ might someday need runtime
> support that cannot be ported into the kernel.

I managed to use a a lot of C++ code in a kernel modules. I used wrapper
functions to pass data between C and C++ parts. C++ code had no exceptions
and such thing, but I had to play some dirty tricks anyway because C++
code needs stuff which is provided by userpace libraries to run.
Maybe the right solution is writing a module that provides a fast data
path between the kernel and the userspace router.


--
Giuliano.