linux-stable.git/tools/testing/selftests/bpf, branch v6.1.78

selftests/bpf: Fix issues in setup_classid_environment()

2024-02-05T20:12:50+00:00

[ Upstream commit 4849775587844e44d215289c425bcd70f315efe7 ]

If the net_cls subsystem is already mounted, attempting to mount it again
in setup_classid_environment() will result in a failure with the error code
EBUSY. Despite this, tmpfs will have been successfully mounted at
/sys/fs/cgroup/net_cls. Consequently, the /sys/fs/cgroup/net_cls directory
will be empty, causing subsequent setup operations to fail.

Here's an error log excerpt illustrating the issue when net_cls has already
been mounted at /sys/fs/cgroup/net_cls prior to running
setup_classid_environment():

- Before that change

  $ tools/testing/selftests/bpf/test_progs --name=cgroup_v1v2
  test_cgroup_v1v2:PASS:server_fd 0 nsec
  test_cgroup_v1v2:PASS:client_fd 0 nsec
  test_cgroup_v1v2:PASS:cgroup_fd 0 nsec
  test_cgroup_v1v2:PASS:server_fd 0 nsec
  run_test:PASS:skel_open 0 nsec
  run_test:PASS:prog_attach 0 nsec
  test_cgroup_v1v2:PASS:cgroup-v2-only 0 nsec
  (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup.procs
  (cgroup_helpers.c:540: errno: No such file or directory) Opening cgroup classid: /sys/fs/cgroup/net_cls/cgroup-test-work-dir/net_cls.classid
  run_test:PASS:skel_open 0 nsec
  run_test:PASS:prog_attach 0 nsec
  (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup-test-work-dir/cgroup.procs
  run_test:FAIL:join_classid unexpected error: 1 (errno 2)
  test_cgroup_v1v2:FAIL:cgroup-v1v2 unexpected error: -1 (errno 2)
  (cgroup_helpers.c:248: errno: No such file or directory) Opening Cgroup Procs: /sys/fs/cgroup/net_cls/cgroup.procs
  #44      cgroup_v1v2:FAIL
  Summary: 0/0 PASSED, 0 SKIPPED, 1 FAILED

- After that change
  $ tools/testing/selftests/bpf/test_progs --name=cgroup_v1v2
  #44      cgroup_v1v2:OK
  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Yafang Shao 
Link: https://lore.kernel.org/r/20231111090034.4248-3-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

selftests/bpf: Fix pyperf180 compilation failure with clang18

2024-02-05T20:12:49+00:00

[ Upstream commit 100888fb6d8a185866b1520031ee7e3182b173de ]

With latest clang18 (main branch of llvm-project repo), when building bpf selftests,
    [~/work/bpf-next (master)]$ make -C tools/testing/selftests/bpf LLVM=1 -j

The following compilation error happens:
    fatal error: error in backend: Branch target out of insn range
    ...
    Stack dump:
    0.      Program arguments: clang -g -Wall -Werror -D__TARGET_ARCH_x86 -mlittle-endian
      -I/home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/include
      -I/home/yhs/work/bpf-next/tools/testing/selftests/bpf -I/home/yhs/work/bpf-next/tools/include/uapi
      -I/home/yhs/work/bpf-next/tools/testing/selftests/usr/include -idirafter
      /home/yhs/work/llvm-project/llvm/build.18/install/lib/clang/18/include -idirafter /usr/local/include
      -idirafter /usr/include -Wno-compare-distinct-pointer-types -DENABLE_ATOMICS_TESTS -O2 --target=bpf
      -c progs/pyperf180.c -mcpu=v3 -o /home/yhs/work/bpf-next/tools/testing/selftests/bpf/pyperf180.bpf.o
    1.       parser at end of file
    2.      Code generation
    ...

The compilation failure only happens to cpu=v2 and cpu=v3. cpu=v4 is okay
since cpu=v4 supports 32-bit branch target offset.

The above failure is due to upstream llvm patch [1] where some inlining behavior
are changed in clang18.

To workaround the issue, previously all 180 loop iterations are fully unrolled.
The bpf macro __BPF_CPU_VERSION__ (implemented in clang18 recently) is used to avoid
unrolling changes if cpu=v4. If __BPF_CPU_VERSION__ is not available and the
compiler is clang18, the unrollng amount is unconditionally reduced.

  [1] https://github.com/llvm/llvm-project/commit/1a2e77cf9e11dbf56b5720c607313a566eebb16e

Signed-off-by: Yonghong Song 
Signed-off-by: Andrii Nakryiko 
Tested-by: Alan Maguire 
Link: https://lore.kernel.org/bpf/20231110193644.3130906-1-yonghong.song@linux.dev
Signed-off-by: Sasha Levin

selftests/bpf: satisfy compiler by having explicit return in btf test

2024-02-05T20:12:49+00:00

[ Upstream commit f4c7e887324f5776eef6e6e47a90e0ac8058a7a8 ]

Some compilers complain about get_pprint_mapv_size() not returning value
in some code paths. Fix with explicit return.

Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/r/20231102033759.2541186-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

selftests/bpf: Add assert for user stacks in test_task_stack

2024-01-25T23:27:38+00:00

commit 727a92d62fd6a382b4c5972008e45667e707b0e4 upstream.

This is a follow up to:
commit b8e3a87a627b ("bpf: Add crosstask check to __bpf_get_stack").

This test ensures that the task iterator only gets a single
user stack (for the current task).

Signed-off-by: Jordan Rome 
Signed-off-by: Andrii Nakryiko 
Acked-by: Stanislav Fomichev 
Link: https://lore.kernel.org/bpf/20231112023010.144675-1-linux@jordanrome.com
Signed-off-by: Greg Kroah-Hartman

selftests/bpf: Relax time_tai test for equal timestamps in tai_forward

2024-01-25T23:27:27+00:00

[ Upstream commit e1ba7f64b192f083b4423644be03bb9e3dc8ae84 ]

We're observing test flakiness on an arm64 platform which might not
have timestamps as precise as x86. The test log looks like:

  test_time_tai:PASS:tai_open 0 nsec
  test_time_tai:PASS:test_run 0 nsec
  test_time_tai:PASS:tai_ts1 0 nsec
  test_time_tai:PASS:tai_ts2 0 nsec
  test_time_tai:FAIL:tai_forward unexpected tai_forward: actual 1702348135471494160 <= expected 1702348135471494160
  test_time_tai:PASS:tai_gettime 0 nsec
  test_time_tai:PASS:tai_future_ts1 0 nsec
  test_time_tai:PASS:tai_future_ts2 0 nsec
  test_time_tai:PASS:tai_range_ts1 0 nsec
  test_time_tai:PASS:tai_range_ts2 0 nsec
  #199     time_tai:FAIL

This patch changes ASSERT_GT to ASSERT_GE in the tai_forward assertion
so that equal timestamps are permitted.

Fixes: 64e15820b987 ("selftests/bpf: Add BPF-helper test for CLOCK_TAI access")
Signed-off-by: YiFei Zhu 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20231212182911.3784108-1-zhuyifei@google.com
Signed-off-by: Sasha Levin

selftests/bpf: Fix erroneous bitmask operation

2024-01-25T23:27:25+00:00

[ Upstream commit b6a3451e0847d5d70fb5fa2b2a80ab9f80bf2c7b ]

xdp_synproxy_kern.c is a BPF program that generates SYN cookies on
allowed TCP ports and sends SYNACKs to clients, accelerating synproxy
iptables module.

Fix the bitmask operation when checking the status of an existing
conntrack entry within tcp_lookup() function. Do not AND with the bit
position number, but with the bitmask value to check whether the entry
found has the IPS_CONFIRMED flag set.

Fixes: fb5cd0ce70d4 ("selftests/bpf: Add selftests for raw syncookie helpers")
Signed-off-by: Jeroen van Ingen Schenau 
Signed-off-by: Daniel Borkmann 
Tested-by: Minh Le Hoang 
Link: https://lore.kernel.org/xdp-newbies/CAAi1gX7owA+Tcxq-titC-h-KPM7Ri-6ZhTNMhrnPq5gmYYwKow@mail.gmail.com/T/#u
Link: https://lore.kernel.org/bpf/20231130120353.3084-1-jeroen.vaningenschenau@novoserve.com
Signed-off-by: Sasha Levin

bpf: handle ldimm64 properly in check_cfg()

2024-01-10T16:10:29+00:00

[ Upstream commit 3feb263bb516ee7e1da0acd22b15afbb9a7daa19 ]

ldimm64 instructions are 16-byte long, and so have to be handled
appropriately in check_cfg(), just like the rest of BPF verifier does.

This has implications in three places:
  - when determining next instruction for non-jump instructions;
  - when determining next instruction for callback address ldimm64
    instructions (in visit_func_call_insn());
  - when checking for unreachable instructions, where second half of
    ldimm64 is expected to be unreachable;

We take this also as an opportunity to report jump into the middle of
ldimm64. And adjust few test_verifier tests accordingly.

Acked-by: Eduard Zingerman 
Reported-by: Hao Sun 
Fixes: 475fb78fbf48 ("bpf: verifier (add branch/goto checks)")
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/r/20231110002638.4168352-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

selftests/bpf: fix bpf_loop_bench for new callback verification scheme

2023-12-20T16:00:23+00:00

[ Upstream commit f40bfd1679446b22d321e64a1fa98b7d07d2be08 ]

This is a preparatory change. A follow-up patch "bpf: verify callbacks
as if they are called unknown number of times" changes logic for
callbacks handling. While previously callbacks were verified as a
single function call, new scheme takes into account that callbacks
could be executed unknown number of times.

This has dire implications for bpf_loop_bench:

    SEC("fentry/" SYS_PREFIX "sys_getpgid")
    int benchmark(void *ctx)
    {
            for (int i = 0; i < 1000; i++) {
                    bpf_loop(nr_loops, empty_callback, NULL, 0);
                    __sync_add_and_fetch(&hits, nr_loops);
            }
            return 0;
    }

W/o callbacks change verifier sees it as a 1000 calls to
empty_callback(). However, with callbacks change things become
exponential:
- i=0: state exploring empty_callback is scheduled with i=0 (a);
- i=1: state exploring empty_callback is scheduled with i=1;
  ...
- i=999: state exploring empty_callback is scheduled with i=999;
- state (a) is popped from stack;
- i=1: state exploring empty_callback is scheduled with i=1;
  ...

Avoid this issue by rewriting outer loop as bpf_loop().
Unfortunately, this adds a function call to a loop at runtime, which
negatively affects performance:

            throughput               latency
   before:  149.919 ± 0.168 M ops/s, 6.670 ns/op
   after :  137.040 ± 0.187 M ops/s, 7.297 ns/op

Acked-by: Andrii Nakryiko 
Signed-off-by: Eduard Zingerman 
Link: https://lore.kernel.org/r/20231121020701.26440-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

selftests/bpf: Correct map_fd to data_fd in tailcalls

2023-11-20T10:51:51+00:00

[ Upstream commit 96daa9874211d5497aa70fa409b67afc29f0cb86 ]

Get and check data_fd. It should not check map_fd again.

Meanwhile, correct some 'return' to 'goto out'.

Thank the suggestion from Maciej in "bpf, x64: Fix tailcall infinite
loop"[0] discussions.

[0] https://lore.kernel.org/bpf/e496aef8-1f80-0f8e-dcdd-25a8c300319a@gmail.com/T/#m7d3b601066ba66400d436b7e7579b2df4a101033

Fixes: 79d49ba048ec ("bpf, testing: Add various tail call test cases")
Fixes: 3b0379111197 ("selftests/bpf: Add tailcall_bpf2bpf tests")
Fixes: 5e0b0a4c52d3 ("selftests/bpf: Test tail call counting with bpf2bpf and data on stack")
Signed-off-by: Leon Hwang 
Reviewed-by: Maciej Fijalkowski 
Link: https://lore.kernel.org/r/20230906154256.95461-1-hffilwlqm@gmail.com
Signed-off-by: Martin KaFai Lau 
Signed-off-by: Sasha Levin

selftests/bpf: Clean up fmod_ret in bench_rename test script

2023-09-13T07:42:33+00:00

[ Upstream commit 83a89c4b6ae93481d3f618aba6a29d89208d26ed ]

Running the bench_rename test script, the following error occurs:

  # ./benchs/run_bench_rename.sh
  base      :    0.819 ± 0.012M/s
  kprobe    :    0.538 ± 0.009M/s
  kretprobe :    0.503 ± 0.004M/s
  rawtp     :    0.779 ± 0.020M/s
  fentry    :    0.726 ± 0.007M/s
  fexit     :    0.691 ± 0.007M/s
  benchmark 'rename-fmodret' not found

The bench_rename_fmodret has been removed in commit b000def2e052
("selftests: Remove fmod_ret from test_overhead"), thus remove it
from the runners in the test script.

Fixes: b000def2e052 ("selftests: Remove fmod_ret from test_overhead")
Signed-off-by: Yipeng Zou 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20230814030727.3010390-1-zouyipeng@huawei.com
Signed-off-by: Sasha Levin