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| author | Alexei Starovoitov <ast@kernel.org> | 2021-03-30 17:31:01 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-03-30 17:31:01 +0300 |
| commit | b83fd195c228bdb7b45f3933919296fa6511fcf5 (patch) | |
| tree | cc106d4d1855ac947d36da6a67d36fa52a55ba85 /tools | |
| parent | 7aae231ac93b9d9c45487dcafd844fa756069f3b (diff) | |
| parent | 2ba4badca9977b64c966b0177920daadbd5501fe (diff) | |
| download | linux-b83fd195c228bdb7b45f3933919296fa6511fcf5.tar.xz | |
Merge branch 'bpf: Update doc about calling kernel function'
Martin KaFai says:
====================
This set updates the document about the bpf program calling kernel
function. In particular, updates are regarding to the clang
requirement in selftests and kfunc-call not an ABI.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools')
| -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 |