While this is an interesting project, I found following grating:
"Permissions without root
You don’t need root. Grant capabilities to SBCL:
sudo setcap cap_bpf,cap_perfmon+ep /usr/bin/sbcl
Now sbcl --load my-bpf-program.lisp works as your regular user. Tracepoint format files need chmod a+r to allow non-root compilation with deftracepoint."
That's obviously not ideal. Better might be to create a purpose-built image. Unlike perl, sbcl doesn't even pretend to care about security. Taint mode extension for sbcl, anybody?
I wonder if a taint mode for SBCL would mean ignoring SBCL_HOME... that'd be a bit annoying for running more up-to-date SBCL versions on distros shipping with older versions.
very cool and the person has the skills to do that. sad to see how the fully AI generated "why this matters" section in the blog gives a lingering vibe of slop.
> sad to see how the fully AI generated "why this matters" section in the blog gives a lingering vibe of slop.
I am quoting this verbatim from offending section:
Why this matters
The traditional eBPF workflow is: write C for the BPF side, compile with clang, then write Go or Rust or Python for the userspace side. Two languages, separate build steps, multiple processes.
With Whistler 1.0, the workflow is: write Lisp. The compiler, loader, and userspace application share a process. You can develop at the REPL — modify a probe, re-eval the form, see results immediately. The feedback loop is instant.
Seems like a reasonable paragraph. I sincerely feel we must stop tainting things with the "slop" pejorative unless it really seems egregious. Also in 2026 is it easy to be so confident about what was generated by a human, edited by a human or generated by an LLM ?
My main metric is: does the paragraph add value ? It does to me as a summary.
The whistler code you inline with your common lisp is an s-expression based DSL. So you can use common lisp macros, but those macros are generating something that will look familiar to CL devs but is restricted based on the eBPF archictecture and validator requirements. eg. it only supports bounded `dotimes`, some basic progn/let/when/if/cond/eq/setf/incf/decf and math, and a simple array iterator. No lists, loops, tagbody/go, conditions, etc, etc. There's a manual in the docs directory.
Common Lisp in particular is multi-paradigm. You can write a ton of code and never use recursion once. I doubt bridging this "gap" was in any way difficult.
I enjoyed reading up on his fiber implementation and dabbling with the Java compiler/runtime integration.
https://atgreen.github.io/repl-yell/posts/sbcl-fibers/
https://github.com/atgreen/openldk
Kudos Anthony - you make the world a more interesting place ;-)