Re: [PATCHv5 bpf-next 05/13] bpf: Allow return values 0 and 1 for uprobe/kprobe session

[Jiri Olsa]

On Mon, Sep 30, 2024 at 02:36:28PM -0700, Andrii Nakryiko wrote:
> On Sun, Sep 29, 2024 at 1:58 PM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> >
> > The uprobe and kprobe session program can return only 0 or 1,
> > instruct verifier to check for that.
> >
> > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > ---
> >  kernel/bpf/verifier.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> >
> 
> Do we need Fixes: tag?

right, for kprobe session, will add

thanks,
jirka

> 
> Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> 
> 
> > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> > index 7d9b38ffd220..c4d7b7369259 100644
> > --- a/kernel/bpf/verifier.c
> > +++ b/kernel/bpf/verifier.c
> > @@ -15910,6 +15910,16 @@ static int check_return_code(struct bpf_verifier_env *env, int regno, const char
> >                         return -ENOTSUPP;
> >                 }
> >                 break;
> > +       case BPF_PROG_TYPE_KPROBE:
> > +               switch (env->prog->expected_attach_type) {
> > +               case BPF_TRACE_KPROBE_SESSION:
> > +               case BPF_TRACE_UPROBE_SESSION:
> > +                       range = retval_range(0, 1);
> > +                       break;
> > +               default:
> > +                       return 0;
> > +               }
> > +               break;
> >         case BPF_PROG_TYPE_SK_LOOKUP:
> >                 range = retval_range(SK_DROP, SK_PASS);
> >                 break;
> > --
> > 2.46.1
> >