linux-stable/tools/testing/selftests/bpf
Björn Töpel 829725ec7b selftests/bpf: Define local variables at the beginning of a block
Use C89 rules for variable definition.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210122154725.22140-10-bjorn.topel@gmail.com
2021-01-26 00:05:02 +01:00
..
benchs selftests: Remove fmod_ret from test_overhead 2020-09-28 17:20:28 -07:00
bpf_testmod selftests: bpf: Add a new test for bare tracepoints 2021-01-20 14:14:05 -08:00
gnu
map_tests
prog_tests selftest/bpf: Fix typo 2021-01-21 15:58:06 -08:00
progs bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE 2021-01-20 14:23:00 -08:00
verifier selftests/bpf: Add verifier tests for x64 jit jump padding 2021-01-20 14:13:52 -08:00
.gitignore bpf, selftests: Fold test_current_pid_tgid_new_ns into test_progs. 2021-01-20 14:10:35 -08:00
bench.c selftests: Remove fmod_ret from test_overhead 2020-09-28 17:20:28 -07:00
bench.h
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 selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP 2020-12-03 17:23:24 -08:00
bpf_util.h
btf_helpers.c selftests/bpf: Add split BTF dedup selftests 2020-11-05 18:37:31 -08:00
btf_helpers.h selftests/bpf: Add split BTF dedup selftests 2020-11-05 18:37:31 -08:00
cgroup_helpers.c bpf, selftests: Use single cgroup helpers for both test_sockmap/progs 2020-08-01 20:20:59 -07:00
cgroup_helpers.h bpf, selftests: Use single cgroup helpers for both test_sockmap/progs 2020-08-01 20:20:59 -07:00
config selftests/bpf: Add config dependency on BLK_DEV_LOOP 2020-12-03 11:20:21 -08:00
flow_dissector_load.c
flow_dissector_load.h selftests/bpf: Don't use deprecated libbpf APIs 2020-09-03 17:14:40 -07:00
get_cgroup_id_user.c bpf, selftests: Use single cgroup helpers for both test_sockmap/progs 2020-08-01 20:20:59 -07:00
ima_setup.sh selftests/bpf: Silence ima_setup.sh when not running in verbose mode. 2020-12-10 22:14:32 -08:00
Makefile bpf, selftests: Fold test_current_pid_tgid_new_ns into test_progs. 2021-01-20 14:10:35 -08:00
netcnt_common.h
network_helpers.c bpf: selftests: Add fastopen_connect to network_helpers 2020-08-24 14:35:00 -07:00
network_helpers.h bpf: selftests: Add fastopen_connect to network_helpers 2020-08-24 14:35:00 -07:00
README.rst selftest/bpf: Fix rst formatting in readme 2020-11-24 22:59:52 +01:00
settings selftests: bpf: Switch off timeout 2020-08-06 16:57:05 -07:00
test_bpftool.py
test_bpftool.sh
test_bpftool_build.sh selftests, bpftool: Add bpftool (and eBPF helpers) documentation build 2020-09-10 11:02:45 -07:00
test_bpftool_metadata.sh selftests/bpf: Test load and dump metadata with btftool and skel 2020-09-15 18:28:27 -07:00
test_btf.h
test_cgroup_storage.c bpf: Rename BPF_XADD and prepare to encode other atomics in .imm 2021-01-14 18:34:29 -08:00
test_cpp.cpp
test_dev_cgroup.c bpf, selftests: Use single cgroup helpers for both test_sockmap/progs 2020-08-01 20:20:59 -07:00
test_flow_dissector.c
test_flow_dissector.sh
test_ftrace.sh
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.sh
test_lirc_mode2_user.c
test_lpm_map.c
test_lru_map.c
test_lwt_ip_encap.sh
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: Work-around EBUSY errors from hashmap update/delete 2020-12-24 01:35:46 +01:00
test_maps.h
test_netcnt.c bpf, selftests: Use single cgroup helpers for both test_sockmap/progs 2020-08-01 20:20:59 -07:00
test_offload.py Kbuild updates for v5.11 2020-12-22 14:02:39 -08:00
test_progs.c selftests/bpf: Sync RCU before unloading bpf_testmod 2021-01-12 17:23:47 -08:00
test_progs.h bpf: Remove extra lock_sock for TCP_ZEROCOPY_RECEIVE 2021-01-20 14:23:00 -08:00
test_select_reuseport_common.h
test_skb_cgroup_id.sh
test_skb_cgroup_id_user.c bpf, selftests: Use single cgroup helpers for both test_sockmap/progs 2020-08-01 20:20:59 -07:00
test_sock.c bpf, selftests: Use single cgroup helpers for both test_sockmap/progs 2020-08-01 20:20:59 -07:00
test_sock_addr.c selftests/bpf: Rewrite test_sock_addr bind bpf into C 2020-12-02 13:25:11 -08:00
test_sock_addr.sh
test_socket_cookie.c selftests/bpf: Don't use deprecated libbpf APIs 2020-09-03 17:14:40 -07:00
test_sockmap.c selftests/bpf: Fix invalid use of strncat in test_sockmap 2020-12-03 18:07:05 -08:00
test_stub.c
test_sysctl.c bpf, selftests: Use single cgroup helpers for both test_sockmap/progs 2020-08-01 20:20:59 -07:00
test_tag.c
test_tc_edt.sh
test_tc_redirect.sh bpf, selftests: Extend test_tc_redirect to use modified bpf_redirect_neigh() 2020-10-22 01:30:00 +02:00
test_tc_tunnel.sh
test_tcp_check_syncookie.sh
test_tcp_check_syncookie_user.c
test_tcp_hdr_options.h bpf: selftest: Ensure the child sk inherited all bpf_sock_ops_cb_flags 2020-10-02 11:34:48 -07:00
test_tcpbpf.h selftests/bpf: Add Userspace tests for TCP_WINDOW_CLAMP 2020-12-03 17:23:24 -08:00
test_tcpnotify.h
test_tcpnotify_user.c bpf: Fix compilation warning of selftests 2020-08-06 16:58:42 -07:00
test_tunnel.sh selftest/bpf: Add missed ip6ip6 test back 2020-11-10 15:37:45 -08:00
test_verifier.c selftests/bpf: Add verifier tests for x64 jit jump padding 2021-01-20 14:13:52 -08:00
test_verifier_log.c
test_xdp_meta.sh
test_xdp_redirect.sh selftests/bpf: Add xdpdrv mode for test_xdp_redirect 2020-07-31 00:43:49 +02:00
test_xdp_veth.sh
test_xdp_vlan.sh
test_xdp_vlan_mode_generic.sh
test_xdp_vlan_mode_native.sh
test_xdping.sh
test_xsk.sh selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV 2020-12-09 16:44:45 +01:00
testing_helpers.c selftests/bpf: Add link detach tests for cgroup, netns, and xdp bpf_links 2020-08-01 20:38:28 -07:00
testing_helpers.h selftests/bpf: Add link detach tests for cgroup, netns, and xdp bpf_links 2020-08-01 20:38:28 -07:00
trace_helpers.c selftests/bpf: Ksyms_btf to test typed ksyms 2020-10-02 14:59:25 -07:00
trace_helpers.h selftests/bpf: Ksyms_btf to test typed ksyms 2020-10-02 14:59:25 -07:00
urandom_read.c
with_addr.sh
with_tunnels.sh
xdping.c
xdping.h
xdpxceiver.c selftests/bpf: Define local variables at the beginning of a block 2021-01-26 00:05:02 +01:00
xdpxceiver.h selftests/bpf: Remove unused enums 2021-01-26 00:05:01 +01:00
xsk_prereqs.sh selftests/bpf: Xsk selftests - SKB POLL, NOPOLL 2020-12-09 16:44:45 +01:00

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

__ /Documentation/bpf/bpf_devel_QA.rst#q-how-to-run-bpf-selftests


Additional information about selftest failures are
documented here.

profiler[23] test failures with clang/llvm <12.0.0
==================================================

With clang/llvm <12.0.0, the profiler[23] test may fail.
The symptom looks like

.. code-block:: c

  // r9 is a pointer to map_value
  // r7 is a scalar
  17:       bf 96 00 00 00 00 00 00 r6 = r9
  18:       0f 76 00 00 00 00 00 00 r6 += r7
  math between map_value pointer and register with unbounded min value is not allowed

  // the instructions below will not be seen in the verifier log
  19:       a5 07 01 00 01 01 00 00 if r7 < 257 goto +1
  20:       bf 96 00 00 00 00 00 00 r6 = r9
  // r6 is used here

The verifier will reject such code with above error.
At insn 18 the r7 is indeed unbounded. The later insn 19 checks the bounds and
the insn 20 undoes map_value addition. It is currently impossible for the
verifier to understand such speculative pointer arithmetic.
Hence `this patch`__ addresses it on the compiler side. It was committed on llvm 12.

__ https://reviews.llvm.org/D85570

The corresponding C code

.. code-block:: c

  for (int i = 0; i < MAX_CGROUPS_PATH_DEPTH; i++) {
          filepart_length = bpf_probe_read_str(payload, ...);
          if (filepart_length <= MAX_PATH) {
                  barrier_var(filepart_length); // workaround
                  payload += filepart_length;
          }
  }

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`__
has been pushed to llvm 10.x release branch and will be
available in 10.0.1. The patch is available in llvm 11.0.0 trunk.

__  https://reviews.llvm.org/D78466

BPF CO-RE-based tests and Clang version
=======================================

A set of selftests use BPF target-specific built-ins, which might require
bleeding-edge Clang versions (Clang 12 nightly at this time).

Few sub-tests of core_reloc test suit (part of test_progs test runner) require
the following built-ins, listed with corresponding Clang diffs introducing
them to Clang/LLVM. These sub-tests are going to be skipped if Clang is too
old to support them, they shouldn't cause build failures or runtime test
failures:

- __builtin_btf_type_id() [0_, 1_, 2_];
- __builtin_preserve_type_info(), __builtin_preserve_enum_value() [3_, 4_].

.. _0: https://reviews.llvm.org/D74572
.. _1: https://reviews.llvm.org/D74668
.. _2: https://reviews.llvm.org/D85174
.. _3: https://reviews.llvm.org/D83878
.. _4: https://reviews.llvm.org/D83242