On Wed, 8 Sep 2021 11:02:58 -0700 Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> wrote: > > Please describe the expected userspace-visible change from Peter's > > patch in full detail? > > User space expects build_id to be available. Peter patch simply removes > that feature. Are you sure? He ends up with static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, u64 *ips, u32 trace_nr, bool user) { int i; /* cannot access current->mm, fall back to ips */ for (i = 0; i < trace_nr; i++) { id_offs[i].status = BPF_STACK_BUILD_ID_IP; id_offs[i].ip = ips[i]; memset(id_offs[i].build_id, 0, BUILD_ID_SIZE_MAX); } return; } and you're saying that userspace won't like this because we didn't set BPF_STACK_BUILD_ID_VALID?