eBPF is one of the more quietly transformative Linux kernel technologies of the last decade — it lets you run sandboxed programs directly inside the kernel, safely, without writing a kernel module or recompiling anything. Modern observability, security, and networking tooling increasingly runs on top of it.
What Makes It Different from a Kernel Module
Traditional kernel modules run with full kernel privileges and a single bug can crash the entire machine. eBPF programs are verified before being loaded — the kernel’s verifier statically proves the program will terminate and can’t access memory it shouldn’t — then JIT-compiled to native code for near-zero overhead.
Trying It Out with bpftrace
bpftrace gives you a high-level, awk-like scripting language for writing eBPF programs without touching C or libbpf directly — perfect for ad-hoc investigation:
sudo apt install bpftrace
# Trace every process execution on the system in real time
sudo bpftrace -e 'tracepoint:syscalls:sys_enter_execve { printf("%s %s\n", comm, str(args->filename)); }'
# Histogram of read() syscall latency, system-wide
sudo bpftrace -e 'kprobe:vfs_read { @start[tid] = nsecs; }
kretprobe:vfs_read /@start[tid]/ { @latency = hist(nsecs - @start[tid]); delete(@start[tid]); }'
Where eBPF Shows Up in Real Tools
- Cilium — Kubernetes networking and security, replacing iptables-based approaches entirely.
- Falco — runtime security monitoring and intrusion detection.
- Pixie / Parca — zero-instrumentation application observability and continuous profiling.
Why It’s Worth Learning Now
eBPF is quickly becoming the default substrate for anything that needs deep, low-overhead kernel visibility — the days of choosing between “slow strace-style tracing” and “risky custom kernel module” are effectively over for anyone willing to learn this one new tool.