EBPF

EBPF (Extended Berkeley Packet Filter) is a powerful, high-performance virtual machine embedded within the Linux kernel. It enables developers to run sandboxed programs in the kernel space without requiring changes to the kernel source code. Originally designed for packet filtering, EBPF has evolved into a general-purpose tool for a wide range of tasks, including network monitoring, system tracing, security policies, and performance analysis. Its ability to execute safely and efficiently makes it a cornerstone of modern Linux kernel instrumentation and observability.

Preparing the Environment

To work with EBPF programs, several dependencies must be installed and configured. Begin by ensuring the necessary system headers are accessible:

```bash sudo ln -s /usr/include/x86_64-linux-gnu/asm /usr/include/asm ```

Next, install the required development tools and libraries:

```bash sudo apt install bpftool clang llvm libbpf-dev ```

The `bpftool` utility is essential for interacting with EBPF programs. To generate a C header file from the kernel's BTF (BPF Type Format) data, use the following command:

```bash bpftool btf dump file /sys/kernel/btf/vmlinux format c > vmlinux.h ```

This header file is often needed for compiling EBPF programs that interact with kernel structures.

Compiling the Program

Once the environment is set up, EBPF programs can be compiled using `clang` with the BPF target. For example, to compile a program defined in `trace_file_delete.c`, run:

```bash clang -O2 -g -target bpf -c trace_file_delete.c -o trace_file_delete.o ```

The `-O2` flag enables optimization, `-g` includes debug information, and `-target bpf` specifies the BPF virtual machine as the compilation target. The resulting `.o` file is a binary object that can be loaded into the kernel.

Loading the Program

After compilation, the EBPF program must be loaded into the kernel. This is done using `bpftool`:

```bash bpftool prog load trace_file_delete.o /sys/fs/bpf/trace_file_delete ```

This command loads the compiled program into the kernel and maps it to the specified path under `/sys/fs/bpf/`. The path can then be used to manage the program's lifecycle.

Listing Loaded Programs

To verify that the program has been successfully loaded, use the `bpftool prog list` command:

```bash bpftool prog list ```

This command displays a list of all currently loaded EBPF programs, including their IDs, types, and associated file paths.

Unloading the Program

When an EBPF program is no longer needed, it can be unloaded by removing the file mapping:

```bash rm /sys/fs/bpf/trace_file_delete ```

This action unloads the program from the kernel, freeing up resources and ensuring that no residual effects remain.

References

• EBPF-program-on-linux/ Sropi
• EBPF-is-the-bees-knees-for-enterprise-environments WWT
• EBPF-program-7b0efa014142 Medium

Technical articles in this category are applicable to Linux. Debian GNU/Linux is used in examples. Much of the information is also applicable to other Linux distributions and Unix flavours.

This page contains information generated by Ollama. The information was reviewed, and may have been altered, by a human editor before being added to the Featured category. As of July 2026 information generated by AI is not subject to copyright and is thus in the public domain. This page is pending human review.