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Diffstat (limited to '')
| -rw-r--r-- | tools/testing/selftests/bpf/README.rst | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst index 42ef250c7acc..d3c6b3da0bb1 100644 --- a/tools/testing/selftests/bpf/README.rst +++ b/tools/testing/selftests/bpf/README.rst @@ -32,11 +32,19 @@ For more information on about using the script, run: $ tools/testing/selftests/bpf/vmtest.sh -h +In case of linker errors when running selftests, try using static linking: + +.. code-block:: console + + $ LDLIBS=-static vmtest.sh + +.. note:: Some distros may not support static linking. + .. note:: The script uses pahole and clang based on host environment setting. If you want to change pahole and llvm, you can change `PATH` environment variable in the beginning of script. -.. note:: The script currently only supports x86_64. +.. note:: The script currently only supports x86_64 and s390x architectures. Additional information about selftest failures are documented here. @@ -118,11 +126,11 @@ available in 10.0.1. The patch is available in llvm 11.0.0 trunk. __ https://reviews.llvm.org/D78466 -bpf_verif_scale/loop6.o test failure with Clang 12 -================================================== +bpf_verif_scale/loop6.bpf.o test failure with Clang 12 +====================================================== With Clang 12, the following bpf_verif_scale test failed: - * ``bpf_verif_scale/loop6.o`` + * ``bpf_verif_scale/loop6.bpf.o`` The verifier output looks like @@ -206,6 +214,8 @@ btf_tag test and Clang version The btf_tag selftest requires LLVM support to recognize the btf_decl_tag and btf_type_tag attributes. They are introduced in `Clang 14` [0_, 1_]. +The subtests ``btf_type_tag_user_{mod1, mod2, vmlinux}`` also requires +pahole version ``1.23``. Without them, the btf_tag selftest will be skipped and you will observe: @@ -235,7 +245,7 @@ See `kernel llvm reloc`_ for more explanation and some examples. Using clang 13 to compile old libbpf which has static linker support, there will be a compilation failure:: - libbpf: ELF relo #0 in section #6 has unexpected type 2 in .../bpf_tcp_nogpl.o + libbpf: ELF relo #0 in section #6 has unexpected type 2 in .../bpf_tcp_nogpl.bpf.o Here, ``type 2`` refers to new relocation type ``R_BPF_64_ABS64``. To fix this issue, user newer libbpf. |