From 0d7410ea6efcdfda56773999f692bbd5d4e4bc00 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Mon, 17 Dec 2018 17:31:57 -0800 Subject: [PATCH] tools/bpf: check precise {func, line, jited_line}_info_rec_size in test_btf Current btf func_info, line_info and jited_line are designed to be extensible. The record sizes for {func,line}_info are passed to kernel, and the record sizes for {func,line,jited_line}_info are returned to userspace during bpf_prog_info query. In bpf selftests test_btf.c, when testing whether kernel returns a legitimate {func,line, jited_line)_info rec_size, the test only compares to the minimum allowed size. If the returned rec_size is smaller than the minimum allowed size, it is considered incorrect. The minimum allowed size for these three info sizes are equal to current value of sizeof(struct bpf_func_info), sizeof(struct bpf_line_info) and sizeof(__u64). The original thinking was that in the future when rec_size is increased in kernel, the same test should run correctly. But this sacrificed the precision of testing under the very kernel the test is shipped with, and bpf selftest is typically run with the same repo kernel. So this patch changed the testing of rec_size such that the kernel returned value should be equal to the size defined by tools uapi header bpf.h which syncs with kernel uapi header. Martin discovered a bug in one of rec_size comparisons. Instead of comparing to minimum func_info rec_size 8, it compares to 4. This patch fixed that issue as well. Fixes: 999d82cbc044 ("tools/bpf: enhance test_btf file testing to test func info") Fixes: 05687352c600 ("bpf: Refactor and bug fix in test_func_type in test_btf.c") Fixes: 4d6304c76355 ("bpf: Add unit tests for bpf_line_info") Suggested-by: Martin KaFai Lau Acked-by: Martin KaFai Lau Signed-off-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/test_btf.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/bpf/test_btf.c b/tools/testing/selftests/bpf/test_btf.c index b783aa2212cc..8024b7d4c354 100644 --- a/tools/testing/selftests/bpf/test_btf.c +++ b/tools/testing/selftests/bpf/test_btf.c @@ -3408,7 +3408,7 @@ static int do_test_file(unsigned int test_num) goto done; } rec_size = info.func_info_rec_size; - if (CHECK(rec_size < 4, + if (CHECK(rec_size != sizeof(struct bpf_func_info), "incorrect info.func_info_rec_size (1st) %d\n", rec_size)) { err = -1; goto done; @@ -4544,7 +4544,7 @@ static int test_get_finfo(const struct prog_info_raw_test *test, } rec_size = info.func_info_rec_size; - if (CHECK(rec_size < 8, + if (CHECK(rec_size != sizeof(struct bpf_func_info), "incorrect info.func_info_rec_size (1st) %d", rec_size)) { return -1; } @@ -4573,7 +4573,7 @@ static int test_get_finfo(const struct prog_info_raw_test *test, err = -1; goto done; } - if (CHECK(info.func_info_rec_size < 8, + if (CHECK(info.func_info_rec_size != rec_size, "incorrect info.func_info_rec_size (2nd) %d", info.func_info_rec_size)) { err = -1; @@ -4649,8 +4649,8 @@ static int test_get_linfo(const struct prog_info_raw_test *test, goto done; } - if (CHECK(info.line_info_rec_size < 16 || - info.jited_line_info_rec_size < 8, + if (CHECK(info.line_info_rec_size != sizeof(struct bpf_line_info) || + info.jited_line_info_rec_size != sizeof(__u64), "info: line_info_rec_size:%u(userspace expected:%u) jited_line_info_rec_size:%u(userspace expected:%u)", info.line_info_rec_size, rec_size, info.jited_line_info_rec_size, jited_rec_size)) { -- 2.30.2