Re: [PATCH] libbpf: Remove kprobe_event on failed kprobe_open_legacy

[Daniel Borkmann]

On 6/19/22 3:56 AM, chuang wrote:
> On Sun, Jun 19, 2022 at 5:17 AM Jiri Olsa <olsajiri@xxxxxxxxx> wrote:
> > just curious.. is that because of ipmodify flag on ftrace_ops?
> > AFAICS that be a poblem just for kretprobes, cc-ing Masami
>
> Yes, the core reason is caused by ipmodify flag (not only for kretprobes).
> Before commit 0bc11ed5ab60 ("kprobes: Allow kprobes coexist with
> livepatch"), it's very easy to trigger this problem.
> The kprobe has other problems and is communicating with Masami.
>
> With this fix, whenever an error is returned after
> add_kprobe_event_legacy(), this guarantees cleanup of the kprobe
> event.

The details from this follow-up conversation should definitely be part of
the commit description, please add them to a v2 as otherwise context is
missing if we look at the commit again in say few months from now. Also,
would be good if Masami could provide ack given 0bc11ed5ab60.

Thanks,
Daniel