From 8054d51f76c8da880115ffba6189b0efd7a5b5ba Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 28 Feb 2019 15:31:21 -0800 Subject: selftests/bpf: fix btf_dedup testing code btf_dedup testing code doesn't account for length of struct btf_header when calculating the start of a string section. This patch fixes this problem. Fixes: 49b57e0d01db ("tools/bpf: remove btf__get_strings() superseded by raw data API") Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/test_btf.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/.gitignore b/tools/testing/selftests/bpf/.gitignore index e47168d1257d..3b74d23fffab 100644 --- a/tools/testing/selftests/bpf/.gitignore +++ b/tools/testing/selftests/bpf/.gitignore @@ -14,6 +14,7 @@ feature test_libbpf_open test_sock test_sock_addr +test_sock_fields urandom_read test_btf test_sockmap diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index 02d314383a9c..1426c0a905c8 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -5936,9 +5936,9 @@ static int do_test_dedup(unsigned int test_num) } test_hdr = test_btf_data; - test_strs = test_btf_data + test_hdr->str_off; + test_strs = test_btf_data + sizeof(*test_hdr) + test_hdr->str_off; expect_hdr = expect_btf_data; - expect_strs = expect_btf_data + expect_hdr->str_off; + expect_strs = expect_btf_data + sizeof(*test_hdr) + expect_hdr->str_off; if (CHECK(test_hdr->str_len != expect_hdr->str_len, "test_hdr->str_len:%u != expect_hdr->str_len:%u", test_hdr->str_len, expect_hdr->str_len)) { -- cgit v1.3-14-g43fede From 7c7a4890c87dd2eb77ef144e5153a7df4c0d6f53 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 28 Feb 2019 15:31:25 -0800 Subject: selftests/bpf: add btf_dedup test of FWD/STRUCT resolution This patch adds a btf_dedup test exercising logic of STRUCT<->FWD resolution and validating that STRUCT is not resolved to a FWD. It also forces hash collisions, forcing both FWD and STRUCT to be candidates for each other. Previously this condition caused infinite loop due to FWD pointing to STRUCT and STRUCT pointing to its FWD. Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Andrii Nakryiko Acked-by: Song Liu Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_btf.c | 45 ++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) (limited to 'tools/testing') diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index 1426c0a905c8..38797aa627a7 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -5731,6 +5731,51 @@ const struct btf_dedup_test dedup_tests[] = { .dont_resolve_fwds = false, }, }, +{ + .descr = "dedup: struct <-> fwd resolution w/ hash collision", + /* + * // CU 1: + * struct x; + * struct s { + * struct x *x; + * }; + * // CU 2: + * struct x {}; + * struct s { + * struct x *x; + * }; + */ + .input = { + .raw_types = { + /* CU 1 */ + BTF_FWD_ENC(NAME_TBD, 0 /* struct fwd */), /* [1] fwd x */ + BTF_PTR_ENC(1), /* [2] ptr -> [1] */ + BTF_STRUCT_ENC(NAME_TBD, 1, 8), /* [3] struct s */ + BTF_MEMBER_ENC(NAME_TBD, 2, 0), + /* CU 2 */ + BTF_STRUCT_ENC(NAME_TBD, 0, 0), /* [4] struct x */ + BTF_PTR_ENC(4), /* [5] ptr -> [4] */ + BTF_STRUCT_ENC(NAME_TBD, 1, 8), /* [6] struct s */ + BTF_MEMBER_ENC(NAME_TBD, 5, 0), + BTF_END_RAW, + }, + BTF_STR_SEC("\0x\0s\0x\0x\0s\0x\0"), + }, + .expect = { + .raw_types = { + BTF_PTR_ENC(3), /* [1] ptr -> [3] */ + BTF_STRUCT_ENC(NAME_TBD, 1, 8), /* [2] struct s */ + BTF_MEMBER_ENC(NAME_TBD, 1, 0), + BTF_STRUCT_ENC(NAME_NTH(2), 0, 0), /* [3] struct x */ + BTF_END_RAW, + }, + BTF_STR_SEC("\0s\0x"), + }, + .opts = { + .dont_resolve_fwds = false, + .dedup_table_size = 1, /* force hash collisions */ + }, +}, { .descr = "dedup: all possible kinds (no duplicates)", .input = { -- cgit v1.3-14-g43fede