diff options
| author | Yonghong Song <yhs@fb.com> | 2021-09-14 23:10:36 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-09-15 08:49:49 -0700 |
| commit | 2220ecf55c1b7aa36e99b00a6b964f4e5333f9bf (patch) | |
| tree | 58ee06def650c8449d4bd27feb69f8a409a7faa8 | |
| parent | 4c24483e247f8d35cfc22a8d23f0e05690d11805 (diff) | |
selftests/bpf: Skip btf_tag test if btf_tag attribute not supported
Commit c240ba287890 ("selftests/bpf: Add a test with a bpf
program with btf_tag attributes") added btf_tag selftest
to test BTF_KIND_TAG generation from C source code, and to
test kernel validation of generated BTF types.
But if an old clang (clang 13 or earlier) is used, the
following compiler warning may be seen:
progs/tag.c:23:20: warning: unknown attribute 'btf_tag' ignored
and the test itself is marked OK. The compiler warning is bad
and the test itself shouldn't be marked OK.
This patch added the check for btf_tag attribute support.
If btf_tag is not supported by the clang, the attribute will
not be used in the code and the test will be marked as skipped.
For example, with clang 13:
./test_progs -t btf_tag
#21 btf_tag:SKIP
Summary: 1/0 PASSED, 1 SKIPPED, 0 FAILED
The selftests/README.rst is updated to clarify when the btf_tag
test may be skipped.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210915061036.2577971-1-yhs@fb.com
| -rw-r--r-- | tools/testing/selftests/bpf/README.rst | 14 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/btf_tag.c | 6 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/tag.c | 12 |
3 files changed, 31 insertions, 1 deletions
diff --git a/tools/testing/selftests/bpf/README.rst b/tools/testing/selftests/bpf/README.rst index 9b17f2867488..8200c0da2769 100644 --- a/tools/testing/selftests/bpf/README.rst +++ b/tools/testing/selftests/bpf/README.rst @@ -201,6 +201,20 @@ Without it, the error from compiling bpf selftests looks like: __ https://reviews.llvm.org/D93563 +btf_tag test and Clang version +============================== + +The btf_tag selftest require LLVM support to recognize the btf_tag attribute. +It was introduced in `Clang 14`__. + +Without it, the btf_tag selftest will be skipped and you will observe: + +.. code-block:: console + + #<test_num> btf_tag:SKIP + +__ https://reviews.llvm.org/D106614 + Clang dependencies for static linking tests =========================================== diff --git a/tools/testing/selftests/bpf/prog_tests/btf_tag.c b/tools/testing/selftests/bpf/prog_tests/btf_tag.c index f939527ede77..91821f42714d 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_tag.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_tag.c @@ -10,5 +10,11 @@ void test_btf_tag(void) skel = tag__open_and_load(); if (!ASSERT_OK_PTR(skel, "btf_tag")) return; + + if (skel->rodata->skip_tests) { + printf("%s:SKIP: btf_tag attribute not supported", __func__); + test__skip(); + } + tag__destroy(skel); } diff --git a/tools/testing/selftests/bpf/progs/tag.c b/tools/testing/selftests/bpf/progs/tag.c index 17f88c58a6c5..b46b1bfac7da 100644 --- a/tools/testing/selftests/bpf/progs/tag.c +++ b/tools/testing/selftests/bpf/progs/tag.c @@ -4,8 +4,19 @@ #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> +#ifndef __has_attribute +#define __has_attribute(x) 0 +#endif + +#if __has_attribute(btf_tag) #define __tag1 __attribute__((btf_tag("tag1"))) #define __tag2 __attribute__((btf_tag("tag2"))) +volatile const bool skip_tests __tag1 __tag2 = false; +#else +#define __tag1 +#define __tag2 +volatile const bool skip_tests = true; +#endif struct key_t { int a; @@ -20,7 +31,6 @@ struct { __type(value, __u64); } hashmap1 SEC(".maps"); -__u32 total __tag1 __tag2 = 0; static __noinline int foo(int x __tag1 __tag2) __tag1 __tag2 { |