Re: [RFC PATCH bpf-next v1 0/3] bpf: Add BPF program type for overriding tracepoint probes

On 9/18/2025 11:32 PM, Steven Rostedt wrote:

On Thu, 18 Sep 2025 21:15:57 +0800
Fuyu Zhao [off-list ref] wrote:

quoted

As for the reason not to unregister and register a new callback:
callbacks registered directly inside the kernel cannot be unregistered from
user space. From user space, we can only attach additional callbacks
with BPF programs, but can not remove or replace the ones already
registered in the kernel. Therefore, an override mechanism is needed.

The fact that user space cannot unregister or override the current
callbacks, to me is a feature and not a bug.

-- Steve

I see, thank you for sharing your view — I’ll keep it in mind.

Sincerely,
Fuyu