Re: [PATCH bpf-next v2 1/3] bpf: add missing fsession to the verifier log

[Menglong Dong]

On 2026/4/8 21:21 Jiri Olsa <olsajiri@xxxxxxxxx> write:
> On Wed, Apr 08, 2026 at 02:21:07PM +0800, Menglong Dong wrote:
> > The fsession attach type is missed in the verifier log in
> > check_get_func_ip(), bpf_check_attach_target() and check_attach_btf_id().
> > Update them to make the verifier log proper. Meanwhile, update the
> > corresponding selftests.
> > 
> > Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
> > Acked-by: Leon Hwang <leon.hwang@xxxxxxxxx>
> > ---
> > v2:
> > - add a missing FSESSION in bpf_check_attach_target()
> > ---
> >  kernel/bpf/verifier.c                               | 10 +++++-----
> >  tools/testing/selftests/bpf/prog_tests/exceptions.c |  8 ++++----
> >  tools/testing/selftests/bpf/verifier/sleepable.c    |  2 +-
> >  3 files changed, 10 insertions(+), 10 deletions(-)
> > 
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index 594260c1f382..beb660b4c3ec 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> > @@ -11757,7 +11757,7 @@ static int check_get_func_ip(struct bpf_verifier_env *env)
> >  
> >  	if (type == BPF_PROG_TYPE_TRACING) {
> >  		if (!bpf_prog_has_trampoline(env->prog)) {
> > -			verbose(env, "func %s#%d supported only for fentry/fexit/fmod_ret programs\n",
> > +			verbose(env, "func %s#%d supported only for fentry/fexit/fsession/fmod_ret programs\n",
> >  				func_id_name(func_id), func_id);
> >  			return -ENOTSUPP;
> >  		}
> > @@ -25561,7 +25561,7 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
> >  	btf = tgt_prog ? tgt_prog->aux->btf : prog->aux->attach_btf;
> >  	if (!btf) {
> >  		bpf_log(log,
> > -			"FENTRY/FEXIT program can only be attached to another program annotated with BTF\n");
> > +			"FENTRY/FEXIT/FSESSION program can only be attached to another program annotated with BTF\n");
> 
> I wonder this should say 'Tracing program...' instead,
> we have other tracing types not covered in this error
> 
> jirka
> 
> >  		return -EINVAL;
> >  	}
> >  	t = btf_type_by_id(btf, btf_id);
> > @@ -25597,7 +25597,7 @@ int bpf_check_attach_target(struct bpf_verifier_log *log,
> >  		if (aux->func && aux->func[subprog]->aux->exception_cb) {
> >  			bpf_log(log,
> >  				"%s programs cannot attach to exception callback\n",
> > -				prog_extension ? "Extension" : "FENTRY/FEXIT");
> > +				prog_extension ? "Extension" : "FENTRY/FEXIT/FSESSION");

I guess that we'd better use "Tracing" instead of "FENTRY/FEXIT/FSESSION"
here too?

> >  			return -EINVAL;
> >  		}
[...]
> 
>