| Message ID | 1626991540-21097-1-git-send-email-alan.maguire@oracle.com |
|---|---|
| State | New |
| Headers | show |
| Series | [bpf-next] selftests/bpf: add multidimensional array BTF-based data dump test | expand |
On Thu, Jul 22, 2021 at 3:06 PM Alan Maguire <alan.maguire@oracle.com> wrote: > > There are currently no multidimensional array tests for > BTF-based data dumping. In BTF, a multidimensional array is > represented as an array with an element type of array. However, > pahole and llvm collapse multidimensional arrays into a > one-dimensional array [1]. Accordingly, the test uses the BTF > add interfaces to create a multidimensional char [2][4] array, > and tests type-based display matches expectations. > > [1] See Documentation/bpf/btf.rst Section 2.2.3 > > Suggested-by: Andrii Nakryiko <andrii@kernel.org> > Signed-off-by: Alan Maguire <alan.maguire@oracle.com> > --- > tools/testing/selftests/bpf/prog_tests/btf_dump.c | 39 +++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c > index 52ccf0c..70d26cf 100644 > --- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c > +++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c > @@ -681,6 +681,45 @@ static void test_btf_dump_struct_data(struct btf *btf, struct btf_dump *d, > "}", > { .cb = { 0, 0, 1, 0, 0},}); > > + /* multidimensional array; because pahole and llvm collapse arrays Are you sure about llvm collapsing multi-dimensional arrays?... There is entire progs/btf_dump_test_case_multidim.c testing multi-dimensional array ;) > + * with multiple dimensions into a single dimension, we add a > + * multidimensional array explicitly. > + */ > + type_id = btf__find_by_name(btf, "char"); > + if (ASSERT_GT(type_id, 0, "find char")) { > + __s32 index_id, array1_id, array2_id; > + char strs[2][4] = { "one", "two" }; oh, it's a way too happy case :) can you try { "a", "", "abc", "ab" } as well? > + > + index_id = btf__find_by_name(btf, "int"); > + ASSERT_GT(index_id, 0, "find int"); > + > + array2_id = btf__add_array(btf, index_id, type_id, 4); > + ASSERT_GT(array2_id, 0, "add multidim 2"); > + > + array1_id = btf__add_array(btf, index_id, array2_id, 2); > + ASSERT_GT(array1_id, 0, "add multidim 1"); > + > + str[0] = '\0'; > + ret = btf_dump__dump_type_data(d, array1_id, &strs, sizeof(strs), &opts); > + ASSERT_GT(ret, 0, "dump multidimensional array"); > + > + ASSERT_STREQ(str, > +"(char[2][4])[\n" > +" [\n" > +" 'o',\n" > +" 'n',\n" > +" 'e',\n" > +" ],\n" > +" [\n" > +" 't',\n" > +" 'w',\n" > +" 'o',\n" > +" ],\n" > +"]", maybe use compact output for such tests, it won't lose much in terms of readability and will be way more compact > + "multidimensional char array matches"); > + } > + > + > /* struct with bitfields */ > TEST_BTF_DUMP_DATA_C(btf, d, "struct", str, struct bpf_insn, BTF_F_COMPACT, > {.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,}); > -- > 1.8.3.1 >
diff --git a/tools/testing/selftests/bpf/prog_tests/btf_dump.c b/tools/testing/selftests/bpf/prog_tests/btf_dump.c index 52ccf0c..70d26cf 100644 --- a/tools/testing/selftests/bpf/prog_tests/btf_dump.c +++ b/tools/testing/selftests/bpf/prog_tests/btf_dump.c @@ -681,6 +681,45 @@ static void test_btf_dump_struct_data(struct btf *btf, struct btf_dump *d, "}", { .cb = { 0, 0, 1, 0, 0},}); + /* multidimensional array; because pahole and llvm collapse arrays + * with multiple dimensions into a single dimension, we add a + * multidimensional array explicitly. + */ + type_id = btf__find_by_name(btf, "char"); + if (ASSERT_GT(type_id, 0, "find char")) { + __s32 index_id, array1_id, array2_id; + char strs[2][4] = { "one", "two" }; + + index_id = btf__find_by_name(btf, "int"); + ASSERT_GT(index_id, 0, "find int"); + + array2_id = btf__add_array(btf, index_id, type_id, 4); + ASSERT_GT(array2_id, 0, "add multidim 2"); + + array1_id = btf__add_array(btf, index_id, array2_id, 2); + ASSERT_GT(array1_id, 0, "add multidim 1"); + + str[0] = '\0'; + ret = btf_dump__dump_type_data(d, array1_id, &strs, sizeof(strs), &opts); + ASSERT_GT(ret, 0, "dump multidimensional array"); + + ASSERT_STREQ(str, +"(char[2][4])[\n" +" [\n" +" 'o',\n" +" 'n',\n" +" 'e',\n" +" ],\n" +" [\n" +" 't',\n" +" 'w',\n" +" 'o',\n" +" ],\n" +"]", + "multidimensional char array matches"); + } + + /* struct with bitfields */ TEST_BTF_DUMP_DATA_C(btf, d, "struct", str, struct bpf_insn, BTF_F_COMPACT, {.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,});
There are currently no multidimensional array tests for BTF-based data dumping. In BTF, a multidimensional array is represented as an array with an element type of array. However, pahole and llvm collapse multidimensional arrays into a one-dimensional array [1]. Accordingly, the test uses the BTF add interfaces to create a multidimensional char [2][4] array, and tests type-based display matches expectations. [1] See Documentation/bpf/btf.rst Section 2.2.3 Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> --- tools/testing/selftests/bpf/prog_tests/btf_dump.c | 39 +++++++++++++++++++++++ 1 file changed, 39 insertions(+)