Is it possible to develop a loadable kernel module (LKM) on Linux with C++?

Question

When I develop a loadable kernel module (LKM) should I use C?

Is it possible to develop a loadable kernel module (LKM) on Linux with language other than C for example C++?

Answer 1

It may be possible to an extent, but be warned (from http://www.tux.org/lkml/#s15-3 ):

Is it a good idea to write a new driver in C++? The short answer is no, because there isn't any support for C++ drivers in the kernel.

Why not add a C++ interface layer to the kernel to support C++ drivers? The short answer is why bother, since there aren't any C++ drivers for Linux.

I think the best idea is to consult existing resources (there are a few kernel driver books, including a free one online) which are all in C, get the basics figured out, then you can try and see if you can get c++ to work there.

But I very much doubt that will be easy. You don't even have access to the full C standard library in the kernel. Something to think about: it does not link to shared libraries, and the total executable image is usually 2-3 MB.

Answer 2

I'm pretty sure I saw a kernel configuration option somewhere allowing C++ in kernel modules, a while back (but cannot find it again). I can see how certain templates would be very interesting to use in driver modules. Just for anecdotics: the OS X Mach kernel is partly written in C++.

Answer 3

In the end it comes down to object code, which is generated by the Assembler and linked together afterwards.

So yes it is possible, you find a debate about that here .

It depends on what you want to do with the LKM, do you want to use it for yourself and some experiments or is it going to become productive anywhere?

Answer 4

There is an operating system which is rewriting Linux Kernel in C++ it's called Boss-Mool and you can write drivers using C++. Here's the link : https://www.bosslinux.in/boss-mool

Answer 5

Well, the original question was for Linux, not OS X or Windows or whatever.

There is absolutely no way to write a Linux kernel mode driver in C++ ! That's because you would need to link with libstdc++ which will not link with your module. libstdc++ is not available for kernel mode, as simple as that !