Re: [PATCH bpf-next v3 2/4] bpf: Verifier support for sleepable raw tracepoint programs

[Menglong Dong <menglong.dong@linux.dev>]

On 2026/3/12 13:50 Leon Hwang <leon.hwang@linux.dev> write:
> On 12/3/26 07:07, Kumar Kartikeya Dwivedi wrote:
> > On Wed, 11 Mar 2026 at 19:53, <bot+bpf-ci@kernel.org> wrote:
> >>
> >>> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> >>> --- a/kernel/bpf/verifier.c
> >>> +++ b/kernel/bpf/verifier.c
> >>
> >> [ ... ]
> >>
> >>> @@ -25435,6 +25441,7 @@ static bool can_be_sleepable(struct bpf_prog *prog)
> >>>               case BPF_MODIFY_RETURN:
> >>>               case BPF_TRACE_ITER:
> >>>               case BPF_TRACE_FSESSION:
> >>> +             case BPF_TRACE_RAW_TP:
> >>>                       return true;
> >>>               default:
> >>>                       return false;
> >>> @@ -25464,7 +25471,7 @@ struct bpf_attach_target_info tgt_info = {};
> >>>       }
> >>>
> >>>       if (prog->sleepable && !can_be_sleepable(prog)) {
> >>> -             verbose(env, "Only fentry/fexit/fmod_ret, lsm, iter, uprobe, and struct_ops programs can be sleepable\n");
> >>> +             verbose(env, "Only fentry/fexit/fmod_ret, lsm, iter, uprobe, struct_ops, and raw_tp programs can be sleepable\n");
> >>
> >> The updated error message adds raw_tp but still omits fsession,
> >> which is listed in can_be_sleepable() just above. Should this
> >> read "fentry/fexit/fmod_ret/fsession, lsm, iter, uprobe,
> >> struct_ops, and raw_tp"?
> >>
> > 
> > We can ignore AI for now, Leon has a change for this.
> > 
> Just to confirm the change: is it
> https://lore.kernel.org/bpf/20260303150639.85007-2-leon.hwang@linux.dev/?
> 
> If yes, it is to add "fsession" to the verbose log message in
> check_get_func_ip(). Then, the AI review is correct: "fsession" was
> missing here.
> 
> After searching for "fexit" in verifier.c, "FENTRY/FEXIT" can be updated
> to "FENTRY/FEXIT/FSESSION" in bpf_check_attach_target(), and "fsession"
> is missing in some comments. I'm not sure whether it is worth a patch to
> do such cleanup work.

Ah, when I search the "fentry.*fexit", I found that there do have
some missed things in:
- the comments
- the log message in check_get_func_ip() and check_attach_btf_id()
- the document in bpftool-prog.rst
- the help info in bpftool
- bash-completion of bpftool

I can send a series to fix these things, except the log message in
check_get_func_ip(), which is already in Leon's patch.

Thanks!
Menglong Dong

> 
> cc Menglong
> 
> Thanks,
> Leon
> 
> 
>