linux/tools/testing/selftests/bpf
YiFei Zhu 9e5bd1f763 selftests/bpf: Test CGROUP_STORAGE map can't be used by multiple progs
The current assumption is that the lifetime of a cgroup storage
is tied to the program's attachment. The storage is created in
cgroup_bpf_attach, and released upon cgroup_bpf_detach and
cgroup_bpf_release.

Because the current semantics is that each attachment gets a
completely independent cgroup storage, and you can have multiple
programs attached to the same (cgroup, attach type) pair, the key
of the CGROUP_STORAGE map, looking up the map with this pair could
yield multiple storages, and that is not permitted. Therefore,
the kernel verifier checks that two programs cannot share the same
CGROUP_STORAGE map, even if they have different expected attach
types, considering that the actual attach type does not always
have to be equal to the expected attach type.

The test creates a CGROUP_STORAGE map and make it shared across
two different programs, one cgroup_skb/egress and one /ingress.
It asserts that the two programs cannot be both loaded, due to
verifier failure from the above reason.

Signed-off-by: YiFei Zhu <zhuyifei@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/30a6b0da67ae6b0296c4d511bfb19c5f3d035916.1595565795.git.zhuyifei@google.com
2020-07-25 20:16:35 -07:00
..
benchs bpf: Add BPF ringbuf and perf buffer benchmarks 2020-06-01 14:38:22 -07:00
gnu
map_tests .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
prog_tests selftests/bpf: Test CGROUP_STORAGE map can't be used by multiple progs 2020-07-25 20:16:35 -07:00
progs selftests/bpf: Test CGROUP_STORAGE map can't be used by multiple progs 2020-07-25 20:16:35 -07:00
verifier selftests/bpf: Add verifier tests for bpf_sk_lookup context access 2020-07-17 20:18:17 -07:00
.gitignore selftests/bpf: Add benchmark runner infrastructure 2020-05-13 12:19:38 -07:00
bench.c bpf: Add BPF ringbuf and perf buffer benchmarks 2020-06-01 14:38:22 -07:00
bench.h selftests/bpf: Add benchmark runner infrastructure 2020-05-13 12:19:38 -07:00
bpf_legacy.h selftests: bpf: Remove unused bpf_map_def_legacy struct 2020-07-08 01:33:14 +02:00
bpf_rand.h
bpf_rlimit.h
bpf_tcp_helpers.h libbpf: Merge selftests' bpf_trace_helpers.h into libbpf's bpf_tracing.h 2020-03-02 16:25:14 -08:00
bpf_util.h selftests: Use consistent include paths for libbpf 2020-01-20 16:37:45 -08:00
cgroup_helpers.c selftests/bpf: Correct path to include msg + path 2019-10-03 17:21:57 +02:00
cgroup_helpers.h
config selftests/bpf: CONFIG_LIRC required for test_lirc_mode2.sh 2020-05-23 01:12:31 +02:00
flow_dissector_load.c
flow_dissector_load.h
get_cgroup_id_user.c
Makefile selftests/bpf: Add test for resolve_btfids 2020-07-13 10:42:03 -07:00
netcnt_common.h
network_helpers.c selftests/bpf: Tests for BPF_SK_LOOKUP attach point 2020-07-17 20:18:17 -07:00
network_helpers.h selftests/bpf: Tests for BPF_SK_LOOKUP attach point 2020-07-17 20:18:17 -07:00
README.rst selftests/bpf: Add general instructions for test execution 2020-05-23 01:11:09 +02:00
tcp_client.py
tcp_server.py
test_bpftool_build.sh selftests, bpftool: Skip the build test if not in tree 2019-11-24 16:58:45 -08:00
test_bpftool.py selftests/bpf: Add test for "bpftool feature" command 2020-02-26 18:34:34 +01:00
test_bpftool.sh selftests/bpf: Add test for "bpftool feature" command 2020-02-26 18:34:34 +01:00
test_btf.c selftests/bpf: Fix a couple of broken test_btf cases 2020-04-24 17:47:40 -07:00
test_btf.h
test_cgroup_storage.c selftests/bpf: fix test_cgroup_storage on s390 2019-08-21 16:55:01 +02:00
test_cpp.cpp selftests: Use consistent include paths for libbpf 2020-01-20 16:37:45 -08:00
test_current_pid_tgid_new_ns.c tools/testing/selftests/bpf: Add self-tests for new helper bpf_get_ns_current_pid_tgid. 2020-03-12 17:40:47 -07:00
test_dev_cgroup.c
test_flow_dissector.c
test_flow_dissector.sh selftests/bpf: Add test based on port range for BPF flow dissector 2020-01-27 11:25:07 +01:00
test_ftrace.sh selftests/bpf: Test function_graph tracer and bpf trampoline together 2019-12-11 15:19:29 -08:00
test_iptunnel_common.h
test_kmod.sh selftests: bpf: test_kmod.sh: Fix running out of srctree 2020-07-21 13:26:24 -07:00
test_lirc_mode2_user.c
test_lirc_mode2.sh
test_lpm_map.c
test_lru_map.c
test_lwt_ip_encap.sh selftests/bpf: More compatible nc options in test_lwt_ip_encap 2019-10-08 23:59:22 +02:00
test_lwt_seg6local.sh selftests/bpf: Fix test_lwt_seg6local.sh hangs 2020-07-21 13:26:26 -07:00
test_maps.c selftests: bpf: Fix detach from sockmap tests 2020-07-09 23:41:37 +02:00
test_maps.h
test_netcnt.c
test_offload.py selftests: bpf: log direct file writes 2019-11-06 09:59:58 -08:00
test_progs.c selftests/bpf: test_progs avoid minus shell exit codes 2020-07-09 00:35:33 +02:00
test_progs.h bpf: selftests: Restore netns after each test 2020-07-02 16:09:01 +02:00
test_select_reuseport_common.h
test_skb_cgroup_id_user.c selftests/bpf: Don't hard-code root cgroup id 2019-12-04 17:56:22 -08:00
test_skb_cgroup_id.sh
test_sock_addr.c selftests/bpf: Test narrow loads for bpf_sock_addr.user_port 2020-05-14 18:30:57 -07:00
test_sock_addr.sh
test_sock_fields.c
test_sock.c selftests: Use consistent include paths for libbpf 2020-01-20 16:37:45 -08:00
test_socket_cookie.c
test_sockmap.c bpf, sockmap: Add ingres skb tests that utilize merge skbs 2020-06-28 08:33:28 -07:00
test_stub.c selftests/bpf: Integrate verbose verifier log into test_progs 2019-11-24 16:58:45 -08:00
test_sysctl.c selftests: Use consistent include paths for libbpf 2020-01-20 16:37:45 -08:00
test_tag.c
test_tc_edt.sh selftests/bpf: More compatible nc options in test_tc_edt 2019-10-18 22:33:57 +02:00
test_tc_tunnel.sh selftests, bpf: Fix test_tc_tunnel hanging 2019-11-18 21:31:49 +01:00
test_tcp_check_syncookie_user.c
test_tcp_check_syncookie.sh
test_tcpbpf_user.c selftests/bpf: De-flake test_tcpbpf 2019-12-04 18:01:05 -08:00
test_tcpbpf.h selftests/bpf: De-flake test_tcpbpf 2019-12-04 18:01:05 -08:00
test_tcpnotify_user.c
test_tcpnotify.h
test_tunnel.sh
test_verifier_log.c
test_verifier.c selftests/bpf: Use CAP_BPF and CAP_PERFMON in tests 2020-05-15 17:29:41 +02:00
test_xdp_meta.sh
test_xdp_redirect.sh
test_xdp_veth.sh
test_xdp_vlan_mode_generic.sh
test_xdp_vlan_mode_native.sh
test_xdp_vlan.sh
test_xdping.sh
testing_helpers.c selftests/bpf: Extract parse_num_list into generic testing_helpers.c 2020-05-13 12:19:38 -07:00
testing_helpers.h selftests/bpf: Extract parse_num_list into generic testing_helpers.c 2020-05-13 12:19:38 -07:00
trace_helpers.c samples, bpf: Move read_trace_pipe to trace_helpers 2020-03-23 22:27:51 +01:00
trace_helpers.h samples, bpf: Move read_trace_pipe to trace_helpers 2020-03-23 22:27:51 +01:00
urandom_read.c
with_addr.sh
with_tunnels.sh
xdping.c selftests: bpf: correct perror strings 2019-11-28 22:40:30 -08:00
xdping.h

==================
BPF Selftest Notes
==================
General instructions on running selftests can be found in
`Documentation/bpf/bpf_devel_QA.rst`_.

Additional information about selftest failures are
documented here.

bpf_iter test failures with clang/llvm 10.0.0
=============================================

With clang/llvm 10.0.0, the following two bpf_iter tests failed:
  * ``bpf_iter/ipv6_route``
  * ``bpf_iter/netlink``

The symptom for ``bpf_iter/ipv6_route`` looks like

.. code-block:: c

  2: (79) r8 = *(u64 *)(r1 +8)
  ...
  14: (bf) r2 = r8
  15: (0f) r2 += r1
  ; BPF_SEQ_PRINTF(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen);
  16: (7b) *(u64 *)(r8 +64) = r2
  only read is supported

The symptom for ``bpf_iter/netlink`` looks like

.. code-block:: c

  ; struct netlink_sock *nlk = ctx->sk;
  2: (79) r7 = *(u64 *)(r1 +8)
  ...
  15: (bf) r2 = r7
  16: (0f) r2 += r1
  ; BPF_SEQ_PRINTF(seq, "%pK %-3d ", s, s->sk_protocol);
  17: (7b) *(u64 *)(r7 +0) = r2
  only read is supported

This is due to a llvm BPF backend bug. The fix 
  https://reviews.llvm.org/D78466
has been pushed to llvm 10.x release branch and will be
available in 10.0.1. The fix is available in llvm 11.0.0 trunk.