On 10/28/19 8:24 PM, Alexei Starovoitov wrote: > The return value of raw_tp programs is ignored by __bpf_trace_run() > that calls them. The verifier also allows any value to be returned. > For BTF-enabled raw_tp lets enforce 'return 0', so that return value > can be used for something in the future. > > Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> > --- Looks good, if the return value is ignored, no need to specify anything but 0 for now. Acked-by: Andrii Nakryiko <andriin@xxxxxx> > kernel/bpf/verifier.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index c59778c0fc4d..6b0de04f8b91 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -6279,6 +6279,11 @@ static int check_return_code(struct bpf_verifier_env *env) > case BPF_PROG_TYPE_CGROUP_SYSCTL: > case BPF_PROG_TYPE_CGROUP_SOCKOPT: > break; > + case BPF_PROG_TYPE_RAW_TRACEPOINT: > + if (!env->prog->aux->attach_btf_id) > + return 0; > + range = tnum_const(0); > + break; > default: > return 0; > } >
