Which standard C library is used in kernel modules?

The GNU C Library project provides the core libraries for the GNU system and GNU/Linux systems, as well as many other systems that use Linux as the kernel. These libraries provide critical APIs including ISO C11, POSIX. 1-2008, BSD, OS-specific APIs and more.

Can kernel modules be written in C++?

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.

Is the kernel compiled against AC library like regular user space programs?

As you point out, the C library being used has no impact on the kernel, the kernel doesn’t use the C library. (There’s an indirect impact, since it’s used to build tools the kernel uses during its build process, but that’s extremely unlikely to affect the end result.)

What is the advantage of using Modprobe over Insmod to load a module into the kernel?

The modprobe command offers more features than the more basic insmod and rmmod utilities. modprobe intelligently adds or removes a module from the Linux kernel. Note that for convenience, there is no difference between _ and – in module names (automatic underscore conversion is performed).

Is Linux a kernel C++?

Linux kernel is written in C (and in Assembly in platform-specific portions) language. C language is the only allowed language to write kernel modules. And there is no problem, in most of the cases.

How is kernel space and user space interfaced?

Kernel space is strictly reserved for running a privileged operating system kernel, kernel extensions, and most device drivers. In contrast, user space is the memory area where application software and some drivers execute.

What is kernel space and user space and how it is interfaced?

3.2 Kernel and user space The kernel provides certain services, and user space, that is, everything outside the kernel, both libraries and application programs, uses these. Programs in user space contain system calls that ask the kernel to do something, and the kernel does so, or returns an error code.

What does insmod do in Linux?

insmod command in Linux systems is used to insert modules into the kernel. Linux is an Operating System which allows the user to load kernel modules on run time to extend the kernel functionalities.

Why kernel module can not call libc?

The kernel module can not call libc since libc run under user space. There are some other kernel specified APIs just like printk () to make modules work fine. As I understand that libc is a collection of several standard c function obj (s). It is supposed to exist a collection (or library) to include several kernel standard function objects.

What is the Linux kernel standard library?

So there is no kernel standard library (it is the kernel itself which contains printk ). Conceptually, kernel code is in the freestanding dialect of C; it does not use any C standard library functions (for obscure reasons, Linux kernel code is not compiled with -ffreestanding dialect option to gcc )

Can I use a C library with my own OS?

So, for your own OS, you can of course take a ready-made C library and just recompile it for your OS – but that requires that you tell the library how to call your kernel functions, and your kernel to actually provide those functions.

What is the difference between CPP support and Kernel Library?

The first component, “CPP support,” implements C++ specific things like memory allocators and so on. The second component, “kernel library” is a lightweight implementation of the standard library with low-level functions. Still, actually, this is only a “bridge” between C “library” (in-kernel implementation) and the C++ world.