From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stanislav Fomichev Subject: [PATCH bpf-next 0/6] skip verifier/map tests if kernel support is missing Date: Thu, 13 Dec 2018 11:02:55 -0800 Message-ID: <20181213190301.65816-1-sdf@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Cc: davem@davemloft.net, daniel@iogearbox.net, ecree@solarflare.com, quentin.monnet@netronome.com, Stanislav Fomichev To: netdev@vger.kernel.org, ast@kernel.org Return-path: Received: from mail-vs1-f73.google.com ([209.85.217.73]:56161 "EHLO mail-vs1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726457AbeLMTDP (ORCPT ); Thu, 13 Dec 2018 14:03:15 -0500 Received: by mail-vs1-f73.google.com with SMTP id p8so1325597vsd.22 for ; Thu, 13 Dec 2018 11:03:14 -0800 (PST) Sender: netdev-owner@vger.kernel.org List-ID: If test_maps/test_verifier is running against the kernel which doesn't have _all_ BPF features enabled, it fails with an error. This patch series tries to probe kernel support for each failed test and skip it instead. This lets users run BPF selftests in the not-all-bpf-yes environments and received correct PASS/NON-PASS result. See https://www.spinics.net/lists/netdev/msg539331.html for more context. The series goes like this: * patch #1 adds bpf_prog_type_supported() and bpf_map_type_supported() which query the kernel (insert 'return 0' program or try to create empty map with correct key/value sizes) and return supported/unsupported. Note: this functionality can later be reimplemented on top of Quentin's recent 'bpftool feature' patchset if he decides to move the probes into libbpf. * patch #2 skips sockmap tests in test_maps.c if BPF_MAP_TYPE_SOCKMAP map is not supported (if bpf_create_map fails, we probe the kernel for support) * patch #3 skips verifier tests if test->prog_type is not supported (if bpf_verify_program fails, we probe the kernel for support) * patch #4 skips verifier tests if test fixup map is not supported (if create_map fails, we probe the kernel for support) Note: we can probably move this probe into create_map helper and return some argument instead of adding skip_unsupported_map() to each fixup; but I'm not sure it's better. Also note: in current implementation we still print 'Failed to create hash map' from the create_map, but still skip the test. * next patches fix various small issues that arise from the first four: * patch #5 sets "unknown func bpf_trace_printk#6" prog_type to BPF_PROG_TYPE_TRACEPOINT so it is correctly skipped in CONFIG_BPF_EVENTS=n case * patch #6 exposes BPF_PROG_TYPE_CGROUP_{SKB,SOCK,SOCK_ADDR} only when CONFIG_CGROUP_BPF=y, this makes verifier correctly skip appropriate tests Note: I'm not sure whether it's worth sprinkling CONFIG_CGROUP_BPF ifdefs all around net/core/filter.c, maybe it's enough to do only in bpf_types.h? Stanislav Fomichev (6): selftests/bpf: add map/prog type probe helpers selftests/bpf: skip sockmap in test_maps if kernel doesn't have support selftests/bpf: skip verifier tests for unsupported program types selftests/bpf: skip verifier tests for unsupported map types selftests/bpf: mark verifier test that uses bpf_trace_printk as BPF_PROG_TYPE_TRACEPOINT bpf: BPF_PROG_TYPE_CGROUP_{SKB,SOCK,SOCK_ADDR} require cgroups enabled include/linux/bpf_types.h | 2 + net/core/filter.c | 18 ++++++ tools/testing/selftests/bpf/Makefile | 2 + tools/testing/selftests/bpf/probe_helpers.c | 69 +++++++++++++++++++++ tools/testing/selftests/bpf/probe_helpers.h | 10 +++ tools/testing/selftests/bpf/test_maps.c | 14 ++++- tools/testing/selftests/bpf/test_verifier.c | 45 ++++++++++++-- 7 files changed, 155 insertions(+), 5 deletions(-) create mode 100644 tools/testing/selftests/bpf/probe_helpers.c create mode 100644 tools/testing/selftests/bpf/probe_helpers.h -- 2.20.0.rc2.403.gdbc3b29805-goog