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| author |   Martin KaFai Lau <kafai@fb.com> | 2021-03-29 22:41:56 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2021-03-30 07:31:01 -0700 |
| commit | 2ba4badca9977b64c966b0177920daadbd5501fe (patch) | |
| tree | cc106d4d1855ac947d36da6a67d36fa52a55ba85 | |
| parent | bpf: Update bpf_design_QA.rst to clarify the kfunc call is not ABI (diff) | |
| download | linux-dev-2ba4badca9977b64c966b0177920daadbd5501fe.tar.xz linux-dev-2ba4badca9977b64c966b0177920daadbd5501fe.zip | |
bpf: selftests: Update clang requirement in README.rst for testing kfunc call
This patch updates the README.rst to specify the clang requirement
to compile the bpf selftests that call kernel function.
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20210330054156.2933804-1-kafai@fb.com
| -rw-r--r-- | tools/testing/selftests/bpf/README.rst | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst index 3464161c8eea..65fe318d1e71 100644 --- a/tools/testing/selftests/bpf/README.rst +++ b/tools/testing/selftests/bpf/README.rst @@ -179,3 +179,17 @@ types, which was introduced in `Clang 13`__. The older Clang versions will either crash when compiling these tests, or generate an incorrect BTF. __ https://reviews.llvm.org/D83289 + +Kernel function call test and Clang version +=========================================== + +Some selftests (e.g. kfunc_call and bpf_tcp_ca) require a LLVM support +to generate extern function in BTF. It was introduced in `Clang 13`__. + +Without it, the error from compiling bpf selftests looks like: + +.. code-block:: console + + libbpf: failed to find BTF for extern 'tcp_slow_start' [25] section: -2 + +__ https://reviews.llvm.org/D93563 |