From: Jiri Olsa jolsa@kernel.org

[ Upstream commit ad8848535e97f4a5374fc68f7a5d16e2565940cc ]

There's a kernel bug that causes cookies to be misplaced and the reason we did not catch this with this test is that we provide bpf_fentry_test* functions already sorted by name.

Shuffling function bpf_fentry_test2 deeper in the list and keeping the current cookie values as before will trigger the bug.

The kernel fix is coming in following changes.

Acked-by: Song Liu songliubraving@fb.com Signed-off-by: Jiri Olsa jolsa@kernel.org Link: https://lore.kernel.org/r/20220615112118.497303-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- .../selftests/bpf/prog_tests/bpf_cookie.c | 78 +++++++++---------- .../selftests/bpf/progs/kprobe_multi.c | 24 +++--- 2 files changed, 51 insertions(+), 51 deletions(-)

diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c index 923a6139b2d8..aebbbb8f983f 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_cookie.c @@ -118,24 +118,24 @@ static void kprobe_multi_link_api_subtest(void) })

GET_ADDR("bpf_fentry_test1", addrs[0]); - GET_ADDR("bpf_fentry_test2", addrs[1]); - GET_ADDR("bpf_fentry_test3", addrs[2]); - GET_ADDR("bpf_fentry_test4", addrs[3]); - GET_ADDR("bpf_fentry_test5", addrs[4]); - GET_ADDR("bpf_fentry_test6", addrs[5]); - GET_ADDR("bpf_fentry_test7", addrs[6]); + GET_ADDR("bpf_fentry_test3", addrs[1]); + GET_ADDR("bpf_fentry_test4", addrs[2]); + GET_ADDR("bpf_fentry_test5", addrs[3]); + GET_ADDR("bpf_fentry_test6", addrs[4]); + GET_ADDR("bpf_fentry_test7", addrs[5]); + GET_ADDR("bpf_fentry_test2", addrs[6]); GET_ADDR("bpf_fentry_test8", addrs[7]);

#undef GET_ADDR

- cookies[0] = 1; - cookies[1] = 2; - cookies[2] = 3; - cookies[3] = 4; - cookies[4] = 5; - cookies[5] = 6; - cookies[6] = 7; - cookies[7] = 8; + cookies[0] = 1; /* bpf_fentry_test1 */ + cookies[1] = 2; /* bpf_fentry_test3 */ + cookies[2] = 3; /* bpf_fentry_test4 */ + cookies[3] = 4; /* bpf_fentry_test5 */ + cookies[4] = 5; /* bpf_fentry_test6 */ + cookies[5] = 6; /* bpf_fentry_test7 */ + cookies[6] = 7; /* bpf_fentry_test2 */ + cookies[7] = 8; /* bpf_fentry_test8 */

opts.kprobe_multi.addrs = (const unsigned long *) &addrs; opts.kprobe_multi.cnt = ARRAY_SIZE(addrs); @@ -146,14 +146,14 @@ static void kprobe_multi_link_api_subtest(void) if (!ASSERT_GE(link1_fd, 0, "link1_fd")) goto cleanup;

- cookies[0] = 8; - cookies[1] = 7; - cookies[2] = 6; - cookies[3] = 5; - cookies[4] = 4; - cookies[5] = 3; - cookies[6] = 2; - cookies[7] = 1; + cookies[0] = 8; /* bpf_fentry_test1 */ + cookies[1] = 7; /* bpf_fentry_test3 */ + cookies[2] = 6; /* bpf_fentry_test4 */ + cookies[3] = 5; /* bpf_fentry_test5 */ + cookies[4] = 4; /* bpf_fentry_test6 */ + cookies[5] = 3; /* bpf_fentry_test7 */ + cookies[6] = 2; /* bpf_fentry_test2 */ + cookies[7] = 1; /* bpf_fentry_test8 */

opts.kprobe_multi.flags = BPF_F_KPROBE_MULTI_RETURN; prog_fd = bpf_program__fd(skel->progs.test_kretprobe); @@ -178,12 +178,12 @@ static void kprobe_multi_attach_api_subtest(void) struct kprobe_multi *skel = NULL; const char *syms[8] = { "bpf_fentry_test1", - "bpf_fentry_test2", "bpf_fentry_test3", "bpf_fentry_test4", "bpf_fentry_test5", "bpf_fentry_test6", "bpf_fentry_test7", + "bpf_fentry_test2", "bpf_fentry_test8", }; __u64 cookies[8]; @@ -195,14 +195,14 @@ static void kprobe_multi_attach_api_subtest(void) skel->bss->pid = getpid(); skel->bss->test_cookie = true;

- cookies[0] = 1; - cookies[1] = 2; - cookies[2] = 3; - cookies[3] = 4; - cookies[4] = 5; - cookies[5] = 6; - cookies[6] = 7; - cookies[7] = 8; + cookies[0] = 1; /* bpf_fentry_test1 */ + cookies[1] = 2; /* bpf_fentry_test3 */ + cookies[2] = 3; /* bpf_fentry_test4 */ + cookies[3] = 4; /* bpf_fentry_test5 */ + cookies[4] = 5; /* bpf_fentry_test6 */ + cookies[5] = 6; /* bpf_fentry_test7 */ + cookies[6] = 7; /* bpf_fentry_test2 */ + cookies[7] = 8; /* bpf_fentry_test8 */

opts.syms = syms; opts.cnt = ARRAY_SIZE(syms); @@ -213,14 +213,14 @@ static void kprobe_multi_attach_api_subtest(void) if (!ASSERT_OK_PTR(link1, "bpf_program__attach_kprobe_multi_opts")) goto cleanup;

- cookies[0] = 8; - cookies[1] = 7; - cookies[2] = 6; - cookies[3] = 5; - cookies[4] = 4; - cookies[5] = 3; - cookies[6] = 2; - cookies[7] = 1; + cookies[0] = 8; /* bpf_fentry_test1 */ + cookies[1] = 7; /* bpf_fentry_test3 */ + cookies[2] = 6; /* bpf_fentry_test4 */ + cookies[3] = 5; /* bpf_fentry_test5 */ + cookies[4] = 4; /* bpf_fentry_test6 */ + cookies[5] = 3; /* bpf_fentry_test7 */ + cookies[6] = 2; /* bpf_fentry_test2 */ + cookies[7] = 1; /* bpf_fentry_test8 */

opts.retprobe = true;

diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi.c b/tools/testing/selftests/bpf/progs/kprobe_multi.c index 600be50800f8..8e06c49aa65a 100644 --- a/tools/testing/selftests/bpf/progs/kprobe_multi.c +++ b/tools/testing/selftests/bpf/progs/kprobe_multi.c @@ -54,21 +54,21 @@ static void kprobe_multi_check(void *ctx, bool is_return)

if (is_return) { SET(kretprobe_test1_result, &bpf_fentry_test1, 8); - SET(kretprobe_test2_result, &bpf_fentry_test2, 7); - SET(kretprobe_test3_result, &bpf_fentry_test3, 6); - SET(kretprobe_test4_result, &bpf_fentry_test4, 5); - SET(kretprobe_test5_result, &bpf_fentry_test5, 4); - SET(kretprobe_test6_result, &bpf_fentry_test6, 3); - SET(kretprobe_test7_result, &bpf_fentry_test7, 2); + SET(kretprobe_test2_result, &bpf_fentry_test2, 2); + SET(kretprobe_test3_result, &bpf_fentry_test3, 7); + SET(kretprobe_test4_result, &bpf_fentry_test4, 6); + SET(kretprobe_test5_result, &bpf_fentry_test5, 5); + SET(kretprobe_test6_result, &bpf_fentry_test6, 4); + SET(kretprobe_test7_result, &bpf_fentry_test7, 3); SET(kretprobe_test8_result, &bpf_fentry_test8, 1); } else { SET(kprobe_test1_result, &bpf_fentry_test1, 1); - SET(kprobe_test2_result, &bpf_fentry_test2, 2); - SET(kprobe_test3_result, &bpf_fentry_test3, 3); - SET(kprobe_test4_result, &bpf_fentry_test4, 4); - SET(kprobe_test5_result, &bpf_fentry_test5, 5); - SET(kprobe_test6_result, &bpf_fentry_test6, 6); - SET(kprobe_test7_result, &bpf_fentry_test7, 7); + SET(kprobe_test2_result, &bpf_fentry_test2, 7); + SET(kprobe_test3_result, &bpf_fentry_test3, 2); + SET(kprobe_test4_result, &bpf_fentry_test4, 3); + SET(kprobe_test5_result, &bpf_fentry_test5, 4); + SET(kprobe_test6_result, &bpf_fentry_test6, 5); + SET(kprobe_test7_result, &bpf_fentry_test7, 6); SET(kprobe_test8_result, &bpf_fentry_test8, 8); }