On Fri, Nov 13, 2020 at 10:11 AM Alan Maguire <alan.maguire@xxxxxxxxxx> wrote: > > Verify that specifying a module name in "struct btf_ptr *" along > with a type id of a module-specific type will succeed. > > veth_stats_rx() is chosen because its function signature consists > of a module-specific type "struct veth_stats" and a kernel-specific > one "struct net_device". > > Signed-off-by: Alan Maguire <alan.maguire@xxxxxxxxxx> > --- > .../selftests/bpf/prog_tests/snprintf_btf_mod.c | 96 ++++++++++++++++++++++ > tools/testing/selftests/bpf/progs/btf_ptr.h | 1 + > tools/testing/selftests/bpf/progs/veth_stats_rx.c | 73 ++++++++++++++++ > 3 files changed, 170 insertions(+) > create mode 100644 tools/testing/selftests/bpf/prog_tests/snprintf_btf_mod.c > create mode 100644 tools/testing/selftests/bpf/progs/veth_stats_rx.c > [...] > + err = veth_stats_rx__load(skel); > + if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err)) > + goto cleanup; > + > + bss = skel->bss; > + > + bss->veth_stats_btf_id = btf__find_by_name(veth_btf, "veth_stats"); This is really awkward that this needs to be done from user-space. Libbpf will be able to do this regardless of whether the type is in vmlinux or kernel module. See my comments on patch #1. > + > + if (CHECK(bss->veth_stats_btf_id <= 0, "find 'struct veth_stats'", > + "could not find 'struct veth_stats' in veth BTF: %d", > + bss->veth_stats_btf_id)) > + goto cleanup; > + [...] > + btf_ids[0] = veth_stats_btf_id; > + ptrs[0] = (void *)PT_REGS_PARM1_CORE(ctx); > +#if __has_builtin(__builtin_btf_type_id) nit: there are a bunch of selftests that just assume we have this built-in, so I don't think you need to guard it with #if here. > + btf_ids[1] = bpf_core_type_id_kernel(struct net_device); > + ptrs[1] = (void *)PT_REGS_PARM2_CORE(ctx); > +#endif [...]